Segmental arterial mediolysis: unrecognized cases culled from cases of ruptured aneurysm of abdominal visceral arteries reported in the Japanese literature. Inada Kiyoshi,Maeda Matsuyoshi,Ikeda Tsuneko Pathology, research and practice Segmental arterial mediolysis (SAM) is a rare nonatherosclerotic and noninflammatory arteriopathy that was proposed by Slavin et al. [Segmental mediolytic arteritis. A clinical pathologic study, Lab. Invest. 35 (1976) 23-29]. It mainly involves abdominal visceral arteries and is characterized by lytic degeneration of the media, resulting in intraabdominal bleeding. We collected 27 unrecognized cases of SAM by reviewing microscopic slides of cases of ruptured aneurysms of visceral arteries, except splenic and hepatic aneurysms, reported in the Japanese literature. This paper describes the pathological and clinical features of these cases. The symptom at onset was abdominal pain associated with intraabdominal bleeding in all cases. The most involved artery was the middle colic artery, accounting for 14 (50%), followed by gastric and gastroepiploic arteries, (6 and 5, respectively). Seventy-eight percent of aneurysms were of dissecting type and the rest of pseudoaneurysm type, except for one. Multiple aneurysms were found in 9 cases (33.3%). Pathological lesions were acute in all. The outcome of those who had surgery was good, even in those who had surgery for 1 ruptured aneurysm, leaving the others unmanaged. The relationship of SAM to fibromuscular dysplasia is discussed. Secondary changes in the wall of the accompanying vein to the affected artery are briefly described. It is emphasized that the majority of aneurysms of abdominal visceral arteries are gathered together as SAM as a definite clinical and pathological entity. 10.1016/j.prp.2007.07.010
    Omental apoplexy: Unravelling the mystery. Moriarty Heather K,Martin Katherine,Koukounaras Jim,Goh Gerard S,Clements Warren Journal of medical imaging and radiation oncology INTRODUCTION:To describe cases omental haemorrhage and to review the literature on this topic. METHODS:We describe three cases of spontaneous omental haemorrhage and discuss various management strategies, in an attempt to provide direction for similar cases in the future. RESULTS:A number of case reports of spontaneous or idiopathic omental haemorrhage exist in the literature. These cases are often attributed to an underlying vasculopathy, such as segmental arterial mediolysis (SAM). Appropriate resuscitation is paramount for best outcome. Severe bleeding may require surgery or transcatheter arterial embolisation, which is best performed early if required. Endovascular management using selective catheterisation of the bleeding vessel and embolisation is a minimally invasive alternative to emergent operative intervention. In the three cases we present, endovascular embolisation was performed in two patients, and surgical ligation in a third. Segmental arterial mediolysis is considered the likely aetiology in at least 2 of the 3 cases, based on imaging findings. No further episodes of haemorrhage occurred at follow-up (ranging from 6 months to 2 years). CONCLUSIONS:Acute omental haemorrhage is a rare condition; however, it may be associated with significant morbidity and mortality. CT angiography is the imaging of choice. Management strategies include both endovascular and surgical intervention. 10.1111/1754-9485.13024
    Segmental arterial mediolysis: a precursor to fibromuscular dysplasia? Slavin R E,Saeki K,Bhagavan B,Maas A E Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc We describe five cases of segmental arterial mediolysis (SAM), formerly known as segmental mediolytic arteritis. SAM occurs in epicardial coronary arteries and in the abdominal splanchnic arteries. Patients with abdominal SAM are generally elderly, whereas coronary SAM presents in neonates, children, and young adults. SAM is initiated by mediolysis of the outer media, which can expand to involve the mid- and inner media. Accompanying alterations include fibrinous linear deposits at the medial adventitial junction and replacement of the lysed muscle fibers by fibrin, erythrocytes, and granulation tissue. Transmural mediolysis results in arterial wall gaps frequently complicated by dissecting hematomas and aneurysms. Abdominal hemorrhages stem from these complications. SAM involving abdominal splanchnic arteries clinically presents with abdominal pain and distension, falling hematocrit, and shock. Simultaneous involvement of more than one abdominal artery is frequent, and branches of the celiac axis are most commonly affected. Various disease states that provoke pathologic stimuli for endothelial mediated vasoconstriction occur in the immediate clinical background of patients with SAM. Certain morphologic features of SAM suggest that this arterial lesion is due to vasospasm, which we putatively ascribe to focal endothelial paracrine dysfunction. Organization of uncomplicated SAM lesions could resemble certain types of fibromuscular dysplasia, suggesting that the genesis of such arterial lesions is related to vasospasm.
    Segmental mediolytic arteritis: a clinical pathologic study. Slavin R E,Gonzalez-Vitale J C Laboratory investigation; a journal of technical methods and pathology A distinct arterial lesion was observed in the large abdominal muscular arteries in three autopsied patients. The salient histopathologic feature of this arterial lesion was either partial or total mediolysis. This was accompanied by a linear fibrin deposit between the media and adventitia and a variable nonpleomorphic inflammatory infiltrate. Total mediolysis led to the formation of arterial gaps. Disecting aneurysms frequently occurred and began either adjacent to arterial gaps or as a result of capillary hemorrhages in areas of partial mediolysis. Ruptured aneurysms led to massive intraabdominal hemorrhages. Arterial luminal occlusion, either by thrombi or dissection, resulted in ischemic bowel changes and renal infarcts. In addition, the arteries affected by mediolysis also showed medial degenerative changes, akin to cystic medial necrosis. Concomitant changes in the kidney showed mesangial hyperplasia; the heart exhibited histiocytic infiltrates and rare Aschoff-like bodies and capsular inflammation were seen in the spleen. The pathogenesis of the arterial lesions is unknown. A possible explanation is that this arteritis may have been induced by immune complexes and that local arterial medial degenerative changes predispose the involved arteries to immunologic injury.
    Potentially stress-induced acute splanchnic segmental arterial mediolysis with a favorable spontaneous outcome. Belbezier Aude,Sarrot-Reynauld Françoise,Thony Frédéric,Tahon Florence,Heck Olivier,Bouillet Laurence Journal of vascular surgery cases and innovative techniques A 62-year-old woman presented with hemithoracic anesthesia and acute abdominal pain following a violent psychological stress. Magnetic resonance imaging showed a thoracic hematoma with arachnoiditis of the spinal cord. Tomography revealed a typical aspect of segmental arterial mediolysis with multiple aneurysms and stenoses of the splanchnic arteries, confirmed by abdominal arteriography. There was no argument for hereditary, traumatic, atherosclerotic, infectious, or inflammatory arterial disease. Segmental arterial mediolysis was diagnosed on the basis of the radiologic data and probably involved both medullary and splanchnic arteries. The patient spontaneously recovered and was in good health 18 months later. 10.1016/j.jvscit.2016.09.002
    [Hematemesis due to rupture of splenic artery pseudoaneurysm in association with segmental arterial mediolysis:a case report]. Nagao Kae,Kuroda Kohei,Fujii Masatoshi,Shirasaka Daisuke,Era Yukiko,Tsuda Kazunori,Tanaka Sanae,Miyazaki Haruka,Hiemori Akiko,Asada Yuya Nihon Shokakibyo Gakkai zasshi The Japanese journal of gastro-enterology A gastric ulcer was detected in a 54-year-old man who underwent upper gastrointestinal endoscopy for hematemesis. An abdominal contrasted computed tomography scan detected a splenic artery aneurysm adjacent to the gastric wall. Endoscopic hemostasis was thought to be risky owing to possible rupture of the aneurysm. Rupture of a splenic artery pseudoaneurysm due to segmental arterial mediolysis (SAM) was diagnosed by abdominal angiography, and subsequently transcatheter arterial embolization was performed. In cases of upper gastrointestinal hemorrhage, hemostasis is often performed during the emergency endoscopic examination. However, in cases of massive gastrointestinal bleeding, the possibility of a splenic artery aneurysm, in association with SAM, should be recognized. The risk of rupturing the aneurysm should be considered in selecting the most suitable treatment. 10.11405/nisshoshi.117.165
    The Intriguing Occurrence of Segmental Arterial Mediolysis: Case Report and Concise Literature Review. Chaudhry Muhammad Ali Cardiovascular & hematological disorders drug targets BACKGROUND:Segmental medial arteriolysis (SAM) is a unique arteriopathy highlighted by significant lytic changes in the medial wall of the blood vessels and can present from vague gastrointestinal discomfort to catastrophic abdominal bleeding and shock. We hereby present a concise review of this rare phenomenon with historic perspectives, epidemiology, and current concepts of etiology, pathogenesis, relevant clinical associations, treatment modalities, prognosis and future directions in SAM. CONCLUSION:In addition, we present an interesting occurrence of this intriguing phenomenon in a forty-eight year old lady at our institution who presented with vague symptomatology and was an extremely challenging diagnosis. This highlights the importance of timely detection and institution of therapeutic or preventive strategies to minimize future catastrophic events. 10.2174/1871529X17666170703115833
    Successful hybrid treatment for huge visceral artery aneurysms with contained rupture complicating segmental arterial mediolysis. Kimura Yasutoshi,Ito Toshiro,Imamura Masafumi,Hirata Koichi Interactive cardiovascular and thoracic surgery Segmental arterial mediolysis (SAM) is a rare arteriopathy that can cause acute abdomen. This report describes the case of a 31-year old male suffering from huge visceral aneurysms with contained rupture. We established a treatment strategy using a hybrid procedure that consisted of endovascular and surgical techniques for these splenic, common hepatic artery and coeliac axis aneurysms related to SAM. The patient was successfully treated with aorto-superior mesenteric artery bypass followed by endovascular aortic stent grafting to interrupt inflow to coeliac aneurysms, and distal splenopancreatectomy with en bloc resection of those aneurysms. We conclude that this hybrid procedure consisting of endovascular and surgical techniques is useful and is a safe treatment option for SAM-related visceral aneurysms. 10.1093/icvts/ivv249
    Case Report: Segmental Arterial Mediolysis, a Rare Cause of Hypertension. Xu Jieqing Jessica,Rasuli Pasteur,Burns Kevin D Canadian journal of kidney health and disease Rationale:The differential diagnosis for hypertension with elevated plasma renin is broad. This case illustrates one of the rarer, and therefore underrecognized, causes of high renin hypertension. Presenting concerns of the patient:A 41-year-old man with a medical history significant for multiple ischemic strokes and dyslipidemia presented for assessment of decreased renal function and resistant hypertension. His initial workup for secondary causes of hypertension was remarkable for an elevated plasma renin and normal aldosterone. Further investigation with computed tomography (CT) angiography was performed, which demonstrated multiple bilateral renal aneurysms and infarcts. Diagnoses:After ruling out other potential causes of bilateral renal aneurysms and infarcts, a diagnosis of segmental arterial mediolysis (SAM) was made. Interventions:Optimization of antihypertensive regimen, counseling regarding regular home blood pressure monitoring, and smoking cessation. Outcomes:The patient achieved excellent blood pressure control, stable renal function, and had no further strokes or other vascular events. Teaching points:Our case demonstrates the importance of considering SAM in the diagnosis of hypertension with elevated plasma renin and as a vasculitis mimic. It also highlights the importance of considering renal vascular imaging in the workup of resistant hypertension. 10.1177/2054358120950885
    Segmental arterial mediolysis with 5 splenic artery aneurysms. A rare finding of a rare disease: Case report and literature review. Termos Salah,Taqi Ali,Hayati Hussein,Alhasan Ameera J M S,Alali Mohammad,Adi Ayman International journal of surgery case reports INTRODUCTION:Splenic artery aneurysms (SAA) are uncommon findings. They are usually single and isolated; however they can be multiple; hence vasculopathy and segmental artery mediolysis may be considered. PRESENTATION OF CASE:In our manuscript we present a case of a 54year old multiparous lady who was discovered incidentally to have a diseased splenic artery containing five SSAs. The largest aneurysm was close to the takeoff of the vessel and the smallest was distal embedded in the splenic hilum. Endovascular option was technically not feasible. Therefore the patient underwent a complete splenic artery resection with splenectomy and the histopathologic examination was suggestive of segmental arterial mediolysis (SAM). DISCUSSION AND CONCLUSION:Multiple SAAs remains a rare finding of a rare disease. Complications can be crucial and high index of suspicion is important. Segmental arterial mediolysis can be considered in patients with several aneurysms on one anatomic site; Angiography is the gold standard diagnostic and therapeutic method. Complete splenic artery resection with splenectomy is the best treatment option for solitary vessel involvement. 10.1016/j.ijscr.2017.02.019
    Segmental Arterial Mediolysis: A Case Study and Review of the Literature in Accurate Diagnosis and Management. Tan Rebekah Vascular specialist international Segmental arterial mediolysis (SAM) is a rare noninflammatory, nonarteriosclerotic arteriopathy of an unknown etiology. It most commonly affects the medium-sized vessels of the abdomen and is characterized by the disruption of the arterial medial layer. Although histological confirmation remains the gold standard in diagnosis, the use of computed tomography angiography (CTA) has greatly aided the diagnosis and surveillance of SAM. Given its rarity and angiographic similarities to other vasculopathies, the diagnosis of SAM can be challenging and is often missed. We describe the case of a 46-year-old male patient who presented to our institution with abdominal pain and multiple foci of intra-abdominal arterial dissections on CTA. We report the acute management via endovascular intervention and review the literature with respect to the diagnosis and management of this rare condition. SAM remains an uncommon yet significant disease process requiring prompt and accurate diagnosis. Initiation of immediate treatment is crucial, given the knowledge gap about its natural progression. 10.5758/vsi.2019.35.3.174
    Biphasic clinical course of a ruptured right gastric artery aneurysm caused by segmental arterial mediolysis: a case report. Kohara Yuichiro,Fujimoto Koji,Katsura Hikotaro,Komatsubara Takashi,Ichikawa Kazuhito,Higashiyama Hiroshi BMC surgery BACKGROUND:Gastric artery aneurysms are rarely caused by segmental arterial mediolysis (SAM), a condition that often involves multiple vessels. The clinical course of SAM after vessel rupture may vary depending on the involved vessels. For example, the "double-rupture phenomenon" observed following the rupture of the splenic artery aneurysm manifests as a biphasic and relatively slow clinical course. Even in cases of rupture of gastric artery aneurysm, the double-rupture phenomenon has only been reported in two cases so far. However, the rupture was not caused by SAM in either case. Herein, we present the apparent first case of a right gastric artery (RGA) aneurysm rupture caused by SAM that presented with a biphasic clinical course, possibly due to the double-rupture phenomenon. CASE PRESENTATION:A 54-year-old woman was transferred to the emergency department with severe abdominal pain and a cold sweat for a duration of 3 h. She had developed mild abdominal pain and nausea 3 days earlier. Her vital signs were stable. Physical examination revealed tenderness in the epigastric area. Abdominal contrast-enhanced computed tomography revealed an RGA aneurysm with contrast media extravasation. A diagnosis of hemoperitoneum following a ruptured RGA aneurysm was made, and the patient underwent angiography. However, this modality did not reveal any extravasation from the RGA due to an interruption in the peripheral branch of the artery. Nevertheless, to prevent major bleeding, we performed coil embolization at the point of interruption in the RGA, which we suspected to be a ruptured aneurysm. A distal gastrectomy with Roux-en-Y reconstruction for aneurysm resection was performed the following day. There were no postoperative complications, and the patient was discharged 17 days after surgery. Histologically, the RGA demonstrated multiple vacuoles in the medial muscle layer, which were characteristic of SAM. CONCLUSIONS:An RGA aneurysm rupture should be considered a differential diagnosis in patients presenting with hemoperitoneum with a slow or biphasic clinical course. 10.1186/s12893-020-00849-x
    Case of Segmental Arterial Mediolysis. Britto Maneka M,Lukies Matthew,Milne Charles,Joseph Timothy,Lee James C BMJ case reports Segmental arterial mediolysis (SAM) is a rare, non-inflammatory, vascular condition that predominantly affects medium-sized to large-sized abdominal arteries and can present with haemorrhage into the abdominal cavity. We report the case of a patient with SAM of the coeliac, splenic, renal and gastroduodenal arteries in whom endovascular coil embolisation was successfully used to treat a bleeding gastroduodenal artery pseudoaneurysm. 10.1136/bcr-2017-223731
    Imaging and clinical findings in segmental arterial mediolysis (SAM). Alhalabi Kinan,Menias Christine,Hines Robert,Mamoun Ihsan,Naidu Sailendra Abdominal radiology (New York) Segmental arterial mediolysis (SAM) is an uncommon, non-atherosclerotic, non-inflammatory arteriopathy that tends to affect the medium-sized splanchnic branches of the aorta along with renal, carotid, cerebral, and coronary arteries. The clinical presentation ranges from asymptomatic to severe, life-threatening intra-abdominal hemorrhage and shock. SAM overlaps clinically and radiologically with other inflammatory vasculitides. This article describes the pathologic-radiologic correlation, imaging findings, and the management of the disease. Radiologists should be familiar with this disease entity as imaging plays a crucial role in the diagnosis. 10.1007/s00261-016-0887-4
    Spontaneous intra-abdominal haemorrhage due to segmental arterial mediolysis following oesophagocolojejunostomy. Lee Jonggeun,Ahn Hyo Yeong,I Hoseok,Kim Chang Won Interactive cardiovascular and thoracic surgery Segmental arterial mediolysis is a rare vascular disease that leads to spontaneous intra-abdominal haemorrhage, which causes shock and bowel ischaemia, and is associated with a high mortality rate. Here, we present a case of spontaneous intra-abdominal haemorrhage due to segmental arterial mediolysis in a patient who underwent oesophagocolojejunostomy for synchronous triple primary cancer, which was treated successfully by coil embolization. We conclude that a preoperative angiogram is necessary to detect vascular abnormalities, and in cases with severe haemorrhage, an urgent endovascular procedure is the treatment of choice. 10.1093/icvts/ivx177
    Segmental arterial mediolysis: a vasculitis mimicker. A single centre experience. Abu Sneineh Marwan,Farkas Adam,Natsheh Ayman,Nesher Gideon,Breuer Gabriel S Clinical and experimental rheumatology OBJECTIVES:Segmental arterial mediolysis (SAM) is a rare vasculopathy of unknown aetiology. It is non-atherosclerotic, non-inflammatory, non-hereditary, non-infectious, large to medium-sized arteriopathy. SAM is a condition which in some circumstances behaves as a vasculitis mimicker and should be recognised in order to provide appropriate treatment and avoid unnecessary immune-suppressive therapy. METHODS:We report a single-centre experience of 6 consecutive SAM cases (3 males and 3 females). A literature search of cases reported with SAM was performed and data summarised. RESULTS:Abdominal or flank pain was the presenting symptom in 5 of the 6 patients. CT angiography (CTA) was the method of diagnosis in all 6 patients. 3 patients underwent therapeutic angiography; 2 with angiographic embolisation because of bleeding, and one patient needed a stent insertion because of left renal infarction. 2 patients underwent FDG-PET to rule out vasculitis. Serological tests were negative in all case, but C-reactive protein was elevated in 4 of them. 2 patients were treated with angiographic embolisation due to bleeding, 2 treated with anti-platelet therapy, one with stent insertion, and one with antihypertensive treatment. A medical literature review of 160 additional cases shows that abdominal or flank pain was the chief complaint in the vast majority of the cases. Renal and abdominal medium-sized arteries were the most commonly involved. CTA was the preferred method of diagnosis. CONCLUSIONS:SAM should be suspected in cases presenting with abdominal or flank pain. Angiographic features should be carefully studied by experienced radiologists to rule out vasculitis.
    Segmental arterial mediolysis presenting as spontaneous bilateral renal artery dissection. Onteddu Nirmal K,Hindi Zakaria,Rajashekar Gaurav,Kalva Sanjeeva P Radiology case reports The commonest site of primary dissection involving the visceral vessels is renal arteries; however, spontaneous bilateral renal artery dissection is an extremely rare entity. Spontaneous renal artery dissection (SRAD) is rarely a cause of renovascular hypertension. Segmental arterial mediolysis is a rare arteriopathy of unknown etiology which is a nonatherosclerotic and noninflammatory condition. We report a case of a 51-year-old male patient with spontaneous dissection of bilateral renal arteries with clinical, laboratory, and angiographic findings consistent with segmental artery mediolysis. Early diagnosis and treatment of this condition will decrease morbidity and mortality. 10.1016/j.radcr.2017.11.017
    Left omental artery bleeding in two patients with segmental arterial mediolysis successfully isolated with coil embolization. Nishiyama Tomoya,Yamada Daisuke,Oba Ken,Kurihara Yasuyuki CVIR endovascular BACKGROUND:Segmental arterial mediolysis (SAM) is a rare, nonatherosclerotic, noninflammatory arteriopathy of unknown etiology, rarely involving omental artery (OA). No case reports have described left OA bleeding successfully treated with transarterial embolization (TAE) with coils. This report describes two cases of SAM-affected left OA bleeding successfully embolized using isolation technique with coils, recognizing the potential for the greater omentum to have arterial collateral network between OAs. CASE PRESENTATION:Case 1. A 55-year-old male with no significant past medical history presented with an acute abdomen. Contrast-enhanced computed tomography (CT) revealed possible hemorrhagic ascites involving the left portion of the greater omentum and dilated, stenotic change of the left OA with a possible hematoma. SAM-associated left OA bleeding was suspected. Given its acute-angled branching from a splenic artery or branch and long, tortuous catheter-trajectory, we used a triaxial catheter system. Left OA angiography revealed the proximal dilated, stenotic change and a distal pseudoaneurysm. Isolation was successfully performed with coils. Because he had no abdominal pain or progressive anemia, he was discharged on hospital day 5. Neither recurrence nor new SAM-associated findings were observed during two-years of follow-up. Case 2. A 60-year-old-man with no significant past medical history presented with an acute abdomen. CT revealed similar finding as Case 1. SAM-associated left OA bleeding was suspected. Left OA angiography revealed proximal dilated, stenotic change with distal occlusion. Despite having no signs of active bleeding, review of the CT and angiography findings suggested the left OA as the bleeding site. Given proximal embolization at this point could lead to incomplete hemostasis or rebleeding via the arterial collateral network between OAs, an attempt was made to navigate the microcatheter into the distal side beyond the occlusion. Distal left OA angiography confirmed that the distal OA over the occlusion was intact and directly communicated with a right OA arising from right gastroepiploic artery. The SAM-associated lesion was successfully isolated with coils. Because he had no abdominal pain or progressive anemia, he was transported to another hospital on hospital day 3. Neither recurrence nor new SAM-associated findings were observed during two-years follow-up. CONCLUSION:SAM can involve left OA and be controlled using an isolation technique with coils. 10.1186/s42155-020-00127-0
    Treatment of Ruptured Vertebral Artery Dissection and Abdominal Hemorrhage Associated with Segmental Arterial Mediolysis Using Endovascular Coil Embolization. Isaji Taiki,Ohshima Tomotaka,Miyachi Shigeru,Matsuo Naoki,Kawaguchi Reo,Takayasu Masakazu World neurosurgery BACKGROUND:Segmental arterial mediolysis is a rare disease characterized by idiopathic noninflammatory vasculopathy involving small to medium arteries. Here, we report a case of ruptured cerebral and abdominal aneurysms, which were successfully treated using emergency endovascular coil embolization. CASE DESCRIPTION:A 45-year-old male suffered subarachnoid hemorrhage caused by the rupture of the right vertebral artery dissecting aneurysm, which was treated using emergency endovascular coiling. Iatrogenic dissection of the left vertebral artery occurred during the procedure. A stent was placed, and antivasospasm therapy was initiated after operation. Eight days after admission, the patient experienced sudden hypovolemic shock because of an abdominal hemorrhage, which was diagnosed as the rupture of an aneurysm in the accessory middle colic artery and treated with urgent coil embolization. CONCLUSIONS:It is extremely rare for a subarachnoid and an abdominal hemorrhage to occur simultaneously during hospitalization. Here, owing to the vulnerability of the unaffected vertebral artery during the initial procedure, segmental arterial mediolysis was diagnosed. 10.1016/j.wneu.2018.05.043
    Extensive Embolization of Splanchnic Artery Aneurysms due to Segmental Arterial Mediolysis. Najafi Arash,Sheikh Gabriel Tobias,Binkert Christoph RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin AIM: Segmental arterial mediolysis (SAM) is a rare non-atherosclerotic, non-inflammatory, non-infectious arteriopathy in middle-aged patients that tends to affect medium-sized splanchnic arteries typically leading to dissecting aneurysms which in case of rupture have a high mortality. Treatment options include watchful waiting and endovascular or surgical intervention. There are no official treatment guidelines and to the best of our knowledge, there has not been any report of extensive exclusion of multiple splanchnic vessel regions in affected patients to date. MATERIALS AND METHODS: We retrospectively examined the outcome of extensive splanchnic embolization in four patients suffering from SAM between 2011 and 2016 with follow-up periods of up to 7 years. RESULTS: One patient presented with abdominal pain due to rupture of aneurysms of the pancreaticoduodenal arcade, one with abdominal pain due to dissection, and two were clinically asymptomatic but displayed rapidly progressing disease over the course of 12 months. All patients were treated with complete exclusion of the diseased vessel segments by coiling all branches to and from the diseased segment. In three cases the main hepatic artery was excluded completely. In one case, the complete vascular bed of the celiac axis was excluded by coiling the distal vessel branches and placing a stent graft over the orifice of the celiac trunk. During a follow-up period of a minimum of 2 and a maximum of 7 years after intervention, there were no immediate or long-term complications except for a temporary arterio-portal fistula. Interestingly, no new diseased areas of SAM were detected afterwards. CONCLUSION: Extensive endovascular exclusion of the entire diseased arterial segment with coils seems to be a safe and effective treatment option in patients with SAM presenting with ruptured or rapidly growing aneurysms. Provided that patients have normal liver function and proper portal venous flow, risk of hepatobiliary complications seems to be low even after extensive embolization. KEY POINTS:  · An asymptomatic SAM can be followed up.. · In case of disease progression or suspicion of aneurysm rupture, an endovascular approach is indicated where the whole pathological vessel bed should be excluded with coils.. · It seems that exclusion of even extensive vessel areas is tolerated.. CITATION FORMAT:· Najafi A, Sheikh GT, Binkert C. Extensive Embolization of Splanchnic Artery Aneurysms due to Segmental Arterial Mediolysis. Fortschr Röntgenstr 2019; 191: 1010 - 1014. 10.1055/a-0855-4198
    Segmental arterial mediolysis: findings at computed tomography angiography. García-Barquín P,Bilbao J I,Quílez A,Aragón M S,Vivas I Radiologia OBJECTIVE:To review the principal findings on computed tomography angiography for segmental arterial mediolysis, and to emphasize the points that help to differentiate it from other vasculopathies such as vasculitis. We also review the protocols for follow-up and the various treatment options. CONCLUSION:Segmental arterial mediolysis is a rare disease that is defined as a non-atherosclerotic, non-hereditary, and non-inflammatory vasculopathy characterized by lysis of the medial layer of the arterial wall. It should be suspected in middle-aged patients with aneurysms, dissections, or spontaneous ruptures of visceral arteries of unknown etiology who do not fulfill the clinical and laboratory criteria for vasculitis. The arteries of the abdominal organs are the most commonly affected, including the arteries of the celiac trunk and the superior and inferior mesenteric arteries. Radiologically, segmental arterial mediolysis can present as arterial dilation; single or multiple, saccular or fusiform aneurysms; stenoses; or dissections. 10.1016/j.rx.2016.05.003
    Natural history and management outcomes of segmental arterial mediolysis. Peng Kate X,Davila Victor J,Stone William M,Shamoun Fadi E,Naidu Sailendra G,McBane Robert D,Money Samuel R Journal of vascular surgery BACKGROUND:Segmental arterial mediolysis (SAM) is a poorly understood, nonatherosclerotic, noninflammatory disease resulting from arterial medial degeneration. Patients may present with aneurysm, dissection, stenosis, or bleeding from visceral or renal arteries. Treatment algorithms are poorly characterized. METHODS:A retrospective review of all patients diagnosed with SAM was performed at our institution. Patients were identified by established criteria that include clinical presentation in combination with radiographic and serologic findings. Demographics, presenting symptoms, diagnostic evaluation, management, and outcomes were reviewed. RESULTS:There were 117 patients diagnosed with SAM between 2000 and 2016; 67.5% (n = 79) were male. Mean age was 52.7 years (range, 23.4-90 years); 69.2% (n = 81) presented with acute abdominal pain, 22.2% (n = 26) with flank pain, and 19.7% (n = 23) with back pain; 15.4% (n = 18) had abdominal pain longer than 30 days; 13.7% (n = 16) had acute hypertension, and 5.1% (n = 6) were hypotensive; 10.3% (n = 12) were asymptomatic. There were 93 (79.5%) dissections and 61 (52.1%) aneurysms. Hemorrhage was seen in 10 (8.5%). The celiac axis was affected in 54.7% (n = 64), renal arteries in 49.6% (n = 5 8), superior mesenteric artery in 43.6% (n = 51), and inferior mesenteric artery in 2.6% (n = 3). After diagnosis of SAM, aspirin was prescribed in 60.7% (n = 71). Statins were prescribed in 29.9% (n = 35). Antihypertensive medications were prescribed in 65% (n = 76), including beta blockers in 42.7% (n = 50); 40.2% (n = 47) of patients were prescribed anticoagulation. Interventions were performed in 26 (22%) patients; 13 had endovascular intervention only, 9 open surgery only, and 4 open and endovascular interventions. Of the 17 patients undergoing endovascular intervention, 19 procedures were performed, most commonly embolization (78.9% [n = 15]), followed by stenting (10.5% [n = 2]). Of the 13 patients undergoing open surgery, 14 procedures were performed, including arterial bypass (50% [n = 7]) and splenectomy with aneurysm ligation (15.4% [n = 2]). Other surgery involved thrombectomy (21.4% [n = 3]) and angioplasty (14.3% [n = 2]). Only 11.5% (n = 3) experienced a perioperative complication, including one hematoma, one abscess, and one death secondary to ongoing hemorrhage. Follow-up imaging was performed in 96.6% (n = 112). Mean follow-up was 1258 days (range, 2-5017 days). Of these, 27.7% (n = 31) had regression, 43.8% (n = 49) stability, and 28.6% (n = 32) progression. Average time between initial diagnosis and progression was 666 days. CONCLUSIONS:SAM is an uncommon disease that may require intervention; it is therefore important that the vascular surgery community be aware of this disease. Follow-up imaging is required to monitor for disease progression. 10.1016/j.jvs.2019.02.068
    Segmental Arterial Mediolysis: An Under-Recognized Cause of Chronic Abdominal Pain. Chatterjee Tulika,Stephens Johnathon,Roy Moni European journal of case reports in internal medicine Segmental arterial mediolysis (SAM) is a non-inflammatory, non-atherosclerotic vasculopathy mostly involving the abdominal arteries. SAM was recently recognized as a more prevalent aetiology of abdominal pain than initially thought by healthcare providers. It is still a commonly missed diagnosis in patients with recurrent emergency room (ER) visits for abdominal pain. Most published case reports in the past have highlighted catastrophic sequelae such as intra-abdominal haemorrhage requiring surgical intervention. We report a case of SAM where the diagnosis was initially missed. After diagnosis, conservative medical management was offered which led to clinical improvement. LEARNING POINTS:To recognize segmental arterial mediolysis (SAM) as a cause of chronic abdominal pain in the middle-aged and elderly population.To differentiate SAM from inflammatory vasculitis and atherosclerotic conditions.For cases with mild symptoms and haemodynamic stability, conservative management such as early lifestyle modifications, hypertension and hyperlipidaemia control and regular imaging follow-up should be offered. 10.12890/2020_001830
    Rare Mesenteric Arterial Diseases: Fibromuscular Dysplasia and Segmental Arterial Mediolysis and Literature Review. Ko Masayoshi,Kamimura Kenya,Sakamaki Akira,Niwa Yusuke,Tominaga Kentaro,Mizuno Kenichi,Terai Shuji Internal medicine (Tokyo, Japan) Fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases that cause aneurysm, occlusion, and thromboses. These diseases are rarely seen in mesenteric arterial lesions; however, as they can be lethal if appropriate management is not provided, the accumulation of clinical information from cases is essential. We herein report the cases of a 57-year-old man diagnosed with FMD and a 63-year-old man diagnosed with SAM. We conclude that an early diagnosis with imaging modalities and clinical information followed by the appropriate treatment improves the prognosis of these arterial diseases. 10.2169/internalmedicine.3094-19
    Segmental Arterial Mediolysis of Omental Arteries with Haemoperitoneum: Case Report with Embolization of the Left Omental Artery and Brief Review of Literature. Rott Gernot,Boecker Frieder Case reports in radiology Segmental arterial mediolysis of an omental artery is an exceptionally rare condition. A 69-year-old man presented with haemoperitoneum six days after being hospitalized due to pneumogenic sepsis. Computed tomography of the abdomen showed a short segment dilatation of an omental artery in the left upper abdomen, compatible with segmental arterial mediolysis. Angiographic examination revealed alterations of omental branches of the right gastroepiploic artery and an aneurysm of the left omental artery, both characteristic of segmental arterial mediolysis. Embolization of the left omental artery with use of N-butyl-2-cyanoacrylate was performed. The postinterventional course was uneventful with increase of haemoglobin levels and without symptoms of omental infarction. Transcatheter embolization in the setting of haemoperitoneum due to segmental arterial mediolysis of an omental branch is technically feasible and a valuable alternative to emergency operation. 10.1155/2018/4749356
    A Ruptured Blood Blister-Like Aneurysm Associated with Intraperitoneal Hemorrhage due to Segmental Arterial Mediolysis: A Case Report and Literature Review. Tanaka Katsuhiro,Fujiwara Masaya,Okuda Yasuyuki,Ishida Fujimaro,Suzuki Hidenori World neurosurgery BACKGROUND:Segmental arterial mediolysis (SAM) is a rare non-atherosclerotic, noninflammatory vascular disease, characterized by mediolysis. We report an extremely rare case of subarachnoid hemorrhage (SAH) due to a ruptured blood blister-like aneurysm (BBA) of the internal carotid artery associated with SAM-related arteriopathy. CASE DESCRIPTION:We experienced a case of SAH followed by intraperitoneal hemorrhage that occurred 12 days after the SAH onset. SAH was caused by a ruptured BBA of the internal carotid artery, which was treated by trapping with high-flow bypass. Intraperitoneal hemorrhage was caused by a rupture of a posterior inferior pancreaticoduodenal artery (PIPDA) aneurysm, which induced hypovolemic shock resulting in death in spite of endovascular internal trapping. Postmortem pathologic examination revealed that the PIPDA pseudoaneurysm was due to SAM. CONCLUSIONS:We should pay attention to the association of SAM, which is a potentially life-threatening pathology when treating cerebral BBAs. 10.1016/j.wneu.2019.10.096
    [A Case of Segmental Arterial Mediolysis:Subarachnoid Hemorrhage Followed by Abdominal Bleeding]. Inazuka Mayuko,Imazato Daisuke,Yamazaki Kei,Maegawa Tatsuya,Takahashi Yuichi,Kikuchi Asami,Yokosako Suguru,Yamada Chika,Arai Naoyuki,Kuroi Yasuhiro,Obuchi Hidenori,Hirota Kengo,Hagiwara Shinji,Tani Shigeru,Hirasawa Motohiro,Yoneyama Taku,Sasahara Atsushi,Kasuya Hidetoshi No shinkei geka. Neurological surgery We describe a case involving subarachnoid and intraperitoneal hemorrhage due to segmental arterial mediolysis(SAM). A 77-year-old female patient with sudden subarachnoid hemorrhage was immediately transferred to our institution. The hemorrhage was classified as grade 2 according to the World Federation of Neurosurgical Societies system. The patient was a non-smoker and did not drink alcohol regularly. A right internal carotid aneurysm was detected using CT angiography and was clipped during frontotemporal craniotomy. Bleeding was observed from the anterior wall of the internal carotid artery, and the tear was clipped. The patient had an uneventful postoperative course until sudden cardiopulmonary arrest eight days after craniotomy. She died of massive intraperitoneal hemorrhage. Autopsy revealed that the hemorrhage was due to dissection of the celiac artery. Tunica media denaturation was observed not only in the celiac artery, but also in the splenic and internal carotid arteries, which exhibited ruptured aneurysms, and the patient was diagnosed with segmental arterial mediolysis(SAM). SAM is an arterial degenerative disease affecting the medial layer of the arterial and dissecting walls. Multiple lesions are sometimes found. Radiographic imaging findings of SAM are similar to those of dissecting aneurysms, which are characterized by a single continuous dissection of the medial layer. As observed in this case, abdominal bleeding caused by SAM can occur after intracranial bleeding. When surgeons encounter unusual intracranial dissecting aneurysms, SAM should be considered as a differential diagnosis. 10.11477/mf.1436203979
    Segmental Arterial Mediolysis Involving Both Vertebral and Middle Colic Arteries Leading to Subarachnoid and Intraperitoneal Hemorrhage. Shinoda Narihide,Hirai Osamu,Mikami Kazuyuki,Bando Toshiaki,Shimo Daisuke,Kuroyama Takahiro,Matsumoto Masato,Itoh Tomoo,Kuramoto Yoji,Ueno Yasushi World neurosurgery BACKGROUND:Segmental arterial mediolysis (SAM) is not yet well known in the neurosurgical field, even though it has become an increasingly recognized pathology in arterial dissection. CASE DESCRIPTION:A case of SAM presented as subarachnoid hemorrhage (SAH) due to a dissecting aneurysm of the left intracranial vertebral artery (VA), which extended from the proximal VA union to the distal portion of the left posterior inferior cerebellar artery. The lesion was successfully embolized by an endovascular technique. However, subsequent intraperitoneal hemorrhage due to rupture of a fusiform aneurysm of the middle colic artery prompted surgical treatments. The features of the extirpated visceral vascular lesion were compatible with the diagnosis of SAM based on histopathologic examinations. CONCLUSIONS:It is very important that SAM is recognized as a systemic disease that affects the central nervous system, visceral arteries, and coronary arteries. The possibility of SAM should always be considered, particularly in patients with ruptured VA dissection-which is nowadays treated by endovascular techniques-since concomitantly involved visceral arteries may cause unexpected hemorrhagic complications other than SAH. 10.1016/j.wneu.2015.12.058
    Subarachnoid Hemorrhage From a Distal Middle Cerebral Artery Aneurysm Possibly Related to Segmental Arterial Mediolysis. Morita Takumi,Maki Yoshinori,Notohara Kenji,Kinosada Masanori,Yasuda Takaya,Chin Masaki World neurosurgery BACKGROUND:Distal middle cerebral artery aneurysm (DMCAAn) is rare, and the clinical features and the etiology are not well understood. Segmental artery mediolysis (SAM) is a pathologic entity that affects the media of the muscular artery and can cause arterial dissection and a hemorrhagic event. Subarachnoid hemorrhage (SAH) due to SAM in the vertebral artery has been documented. However, SAH from a ruptured DMCAAn due to SAM has not yet been described. CASE DESCRIPTION:A 49-year-old woman presented with a headache and vomiting. Computed tomography (CT) revealed SAH, and CT angiography showed a DMCAAn, which was treated by trapping and resection. Histopathologic studies showed loss of the media and reparative changes in the arterial wall including intimal hyperplasia and increased vasa vasorum in the adventitia. These findings were indicative of SAM in the reparative phase. She did not show any other possible etiologies of DMCAAn including infectious endocarditis and vasculitis, and CT angiography of the trunk did not show any other vascular lesions. She was discharged from the hospital approximately 3 weeks after the surgery without any apparent neurological deficits. CONCLUSIONS:Our case suggests that SAM can also occur in the middle cerebral artery and result in DMCAAn. 10.1016/j.wneu.2018.11.031
    Spontaneous isolated dissection of the superior mesenteric artery and aneurysm formation resulting from segmental arterial mediolysis: a case report. Akuzawa Nobuhiro,Kurabayashi Makoto,Suzuki Tsukasa,Yoshinari Daisuke,Kobayashi Mitsunobu,Tanahashi Yoshifumi,Makita Fujio,Saito Ryusei Diagnostic pathology BACKGROUND:Spontaneous isolated dissection of the superior mesenteric artery (SMA) can lead to bowel ischemia, aneurysm rupture, or even death. Studies have suggested that mechanical or hemodynamic stress on the vascular wall of the SMA may be a contributor, but its pathogenesis is unclear. CASE PRESENTATION:A 57-year-old Japanese man with a history of untreated hypertension and hyperuricemia was admitted to our hospital with the sudden onset of severe epigastric pain. Laboratory findings showed elevated white blood cell count and C-reactive protein, and contrast-enhanced computed tomography (CT) of the abdomen demonstrated arterial dissection with luminal stenosis and aneurysm formation at the distal portion of the SMA after the branching of the jejunal artery, and intravenous nicardipine was administered. The patient's epigastric pain resolved spontaneously but recurred on day 6 of his hospital stay. Contrast-enhanced abdominal CT revealed an enlarged aneurysm with wall thinning. Because of the risk of aneurysm rupture, the decision was made to perform aneurysmectomy and bowel resection on day 6. Histologic examinations revealed two separate dissecting lesions: one latent and the other resulting in aneurysm formation. Both lesions showed characteristics of segmental arterial mediolysis (SAM) with lack of arterial media, absence of internal and external elastic laminae and intimal proliferation. CONCLUSIONS:Histologic findings in the present case suggest that mechanical or hemodynamic stress on the vascular wall and SAM-related vascular vulnerability may concomitantly contribute to the onset of isolated SMA dissection. 10.1186/s13000-017-0664-x
    Unexpected intraabdominal hemorrhage due to segmental arterial mediolysis following subarachnoid hemorrhage: A case of ruptured intracranial and intraabdominal aneurysms. Hayashi Satoru,Hosoda Koji,Nishimoto Yo,Nonaka Motonobu,Higuchi Shinya,Miki Toshifumi,Negishi Masatoshi Surgical neurology international Background:Segmental arterial mediolysis (SAM) is an uncommon vascular disease, which manifests as catastrophic intraabdominal hemorrhage caused by rupture of visceral dissecting aneurysms in most cases. The etiology of SAM is still unclear, but SAM may be a vasospastic disorder and the responsible pressor agent is norepinephrine. Recently, abdominal SAM coexisting with intracranial dissecting aneurysms has been reported, but the relationship between intraabdominal and intracranial aneurysms in SAM remains unclear, as no cases of concomitant abdominal SAM and ruptured intracranial saccular aneurysm have been reported. Case Description:A 49-year-old woman underwent emergent clipping for a ruptured saccular aneurysm at the left C1 portion of the internal carotid artery. Intraoperatively, norepinephrine was continuously administered intravenously under general anesthesia. Four days after the subarachnoid hemorrhage (SAH), the patient suddenly developed shock due to massive hematoma in the abdominal cavity. Imaging showed multiple aneurysms involving the splenic artery, gastroduodenal artery, common hepatic artery, and superior mesenteric artery. Coil embolization of the splenic artery was performed immediately to prevent bleeding. Subsequent treatment for cerebral vasospasm following SAH was performed with prevention of hypertension, and the patient recovered with left temporal lobe infarction. The diagnosis was abdominal SAM based on the clinical, imaging, and laboratory findings. Conclusion:Norepinephrine release induced by SAH and/or iatrogenic administration of norepinephrine may have promoted abdominal SAM in this case. Abdominal SAM may occur subsequent to rupture of ordinary saccular aneurysm, and may provoke catastrophic abdominal hemorrhage in the spasm stage after SAH. 10.4103/sni.sni_129_18
    Segmental arterial mediolysis and fibromuscular dysplasia: what comes first, the chicken or the egg? Hall E Tyler,Gibson Blake A,Hennemeyer Charles T,Devis Paola,Black Stacey,Larsen Brandon T Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology Segmental arterial mediolysis (SAM) is a rare vasculopathy characterized by lysis of the outer media in splanchnic arteries and formation of dissecting pseudoaneurysms that may spontaneously rupture, leading to massive and often fatal intraabdominal hemorrhage. The pathogenesis of SAM is poorly understood. Healed SAM lesions closely resemble fibromuscular dysplasia (FMD), leading some authors to postulate that SAM represents a precursor to FMD despite distinct clinical differences between these two disorders. Herein, we present a 61-year-old woman with fatal SAM who showed histologic features in her aorta suggesting the opposite pathogenetic relationship, with an unclassified "FMD-like" arteriopathy preceding development of SAM. 10.1016/j.carpath.2015.11.004
    Subarachnoid and intraperitoneal hemorrhage secondary to segmental arterial mediolysis: A case report and review of the literature. Welch Brian T,Brinjikji Waleed,Stockland Andrew H,Lanzino Giuseppe Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences Background Segmental arterial mediolysis (SAM) is an uncommon or underdiagnosed arteriopathy that presents with life-threatening hemorrhage. SAM can affect the intracranial, spinal, and visceral arteries, with reported cases of concomitant intracranial and visceral hemorrhage. Case description We present the case of a 61-year-old male with concurrent subarachnoid and intraperitoneal hemorrhage caused by simultaneously bleeding posterior spinal artery and splenic artery pseudoaneurysms. The posterior spinal artery pseudoaneurysms were treated with selective injection of polyvinyl alcohol particles into the posterior spinal artery, while the splenic artery pseudoaneurysm was treated with Gelfoam embolization. The constellation of imaging, clinical, and laboratory features led to a presumptive diagnosis of SAM, which remains the only reported cause of concurrent neurovascular and visceral artery aneurysm rupture. Conclusion SAM is a key diagnostic consideration in cases of concomitant intracranial, spinal, and visceral artery aneurysm rupture. 10.1177/1591019917703074
    Segmental arterial mediolysis of varying phases affecting both the intra-abdominal and intracranial vertebral arteries: an autopsy case report. Ro Ayako,Kageyama Norimasa,Takatsu Akihiro,Fukunaga Tatsushige Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology We report an autopsy case of segmental arterial mediolysis (SAM) of various phases occurring in both the intracranial vertebral artery (IVA) and intra-abdominal arteries. The patient was a 70-year-old male found dead in his house. The cause of death was massive intra-abdominal hemorrhage owing to a ruptured right gastroepiploic artery. Histopathological examination revealed that there was a broad arterial dissection as long as 20 cm in the right gastroepiploic artery associated with SAM in the injurious phase. In addition, SAM in the reparative phase was observed as organized arterial dissections in the left gastric artery. Furthermore, SAM in the reparative phase was detected as an arterial dissection in the right IVA undergoing an organizing process. These three lesions were considered to have developed at different times. SAM occurring in both the intra-abdominal and intracranial vertebral arteries is extremely rare. This coincidence may provide a clue to the relationship between SAM and spontaneous IVA dissection. 10.1016/j.carpath.2009.02.002
    A case of segmental arterial mediolysis with widespread involvement of cranial and abdominal arteries. Delafosse Elodie,Armengol Guillaume,Triquenot-Bagan Aude,Hebant Benjamin Journal of the neurological sciences 10.1016/j.jns.2018.12.023
    Segmental arterial mediolysis in splanchnic arteries: an uncommon cause of abdominal pain. Sánchez Melgarejo José Francisco,Fernández Llamas Tania,Pons Miñano José Antonio Revista espanola de enfermedades digestivas : organo oficial de la Sociedad Espanola de Patologia Digestiva Segmental arterial mediolysis is an uncommon arterial disease that primarily involves splanchnic arteries; abdominal pain is the most common clinical manifestation. We report the case of a 53-year-old male with postprandial diffuse abdominal pain of one month's standing. Physical examination was uneventful, and laboratory tests revealed no abnormal findings. Abdominopelvic CT/Angio-CT showed an increased caliber of the superior mesenteric artery resulting from eccentric circumferential wall thickening. The patent lumen had a segment with fusiform aneurysmal dilatation, 7 x 26 mm long. These vascular changes extended along a number of distal jejunal branches, which also presented complete lumen obliteration. Abdominal arteries were free from signs of arteriosclerotic disease. Findings were consistent with segmental arterial mediolysis. 10.17235/reed.2019.6128/2018
    Scleroderma renal crisis with coexisting segmental arterial mediolysis presenting as intraperitoneal bleeding: a case report. Kaneko Shohei,Watanabe Eri,Abe Mai,Watanabe Shinji,Yabe Hiroki,Kojima Shigehiro,Takagi Kenji,Hirai Keiji,Morishita Yoshiyuki,Terai Chihiro Journal of medical case reports BACKGROUND:Segmental arterial mediolysis is a rare nonarteriosclerotic and noninflammatory vascular disease that may cause intraperitoneal bleeding. Scleroderma renal crisis is a rare complication of systemic sclerosis, leading to severe hypertension and renal dysfunction. To the best of our knowledge, this is the first reported case of a patient with concurrent systemic sclerosis with scleroderma renal crisis and pathologically confirmed segmental arterial mediolysis. CASE PRESENTATION:We report a case of a 68-year-old Chinese woman diagnosed with systemic sclerosis who was found to have coexisting segmental arterial mediolysis. She presented with back pain, and massive intraperitoneal bleeding was detected by computed tomography. She underwent laparotomy, and the bleeding was found to originate from the gastroepiploic artery. The pathological examination demonstrated gastroepiploic arterial dissection caused by segmental arterial mediolysis. After surgery, she developed severe hypertension with hyperreninemia and progressive renal dysfunction. Given the risk factors of corticosteroid administration and the presence of anti-ribonucleic acid polymerase III antibody, she was diagnosed with scleroderma renal crisis. The patient was proved to have a very rare case of coexisting scleroderma renal crisis and segmental arterial mediolysis. CONCLUSIONS:There is no known etiological connection between segmental arterial mediolysis and systemic sclerosis or scleroderma renal crisis, but it is possible that coexisting segmental arterial mediolysis and scleroderma renal crisis may have interacted to trigger the development of the other in our patient. 10.1186/s13256-019-1993-z
    Segmental arterial mediolysis. Jurado Basildo C,Santos Armentia E,Silva Priege N,Villanueva Campos A M Radiologia This article reports the case of a 51-year-old woman in whom brain MRI to follow up multiple sclerosis incidentally discovered an intramural hematoma in the extracranial internal carotid artery. MR angiography of the supra-aortic trunks and CT angiography of the aorta showed arterial dilations, aneurysms, dissections, and intramural hematomas in the internal carotid arteries, vertebral arteries, and arteries in the splanchnic territory. These findings raised suspicion of segmental arterial mediolysis. After 6 months of treatment with antiplatelet drugs, the arterial involvement resolved. Segmental arterial mediolysis is an uncommon disease; low clinical suspicion and radiologists' lack of knowledge about this entity mean that it can go undetected or be confused with other vasculitides. This report describes the most relevant pathophysiological findings and correlates them with the imaging findings. 10.1016/j.rx.2019.04.002
    Segmental Arterial Mediolysis with Preceding Symptoms Resembling Viral Infection Hampers the Differentiation from Polyarteritis Nodosa. Nagamura Norihiro,Higuchi Hiroshi Internal medicine (Tokyo, Japan) A middle-aged man presented with a fever, arthralgia, gastrointestinal symptoms, headache, and rash. After two weeks, the patient suddenly complained of severe abdominal pain, and computed tomography revealed aneurysms in the hepatic and splenic arteries, which increased in size progressively. Given the elevated levels of inflammatory markers and orchitis, polyarteritis nodosa (PN) was initially suspected. Catheter embolization for the ruptured hepatic aneurysm and splenectomy for the large splenic ones were performed, and the pathological finding was consistent with segmental arterial mediolysis (SAM). Changes in inflammatory marker levels and aneurysmal size are also informative to differentiate SAM from PN. 10.2169/internalmedicine.2487-18
    Diagnosis and management of fibromuscular dysplasia and segmental arterial mediolysis in gastroenterology field: A mini-review. Ko Masayoshi,Kamimura Kenya,Ogawa Kohei,Tominaga Kentaro,Sakamaki Akira,Kamimura Hiroteru,Abe Satoshi,Mizuno Kenichi,Terai Shuji World journal of gastroenterology The vascular diseases including aneurysm, occlusion, and thromboses in the mesenteric lesions could cause severe symptoms and appropriate diagnosis and treatment are essential for managing patients. With the development and improvement of imaging modalities, diagnostic frequency of these vascular diseases in abdominal lesions is increasing even with the small changes in the vasculatures. Among various vascular diseases, fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases which need to be diagnosed urgently because these diseases could affect various organs and be lethal if the appropriate management is not provided. However, because FMD and SAM are rare, the cause, prevalence, clinical characteristics including the symptoms, findings in the imaging studies, pathological findings, management, and prognoses have not been systematically summarized. Therefore, there have been neither standard diagnostic criteria nor therapeutic methodologies established, to date. To systematically summarize the information and to compare these disease entities, we have summarized the characteristics of FMD and SAM in the gastroenterological regions by reviewing the cases reported thus far. The information summarized will be helpful for physicians treating these patients in an emergency care unit and for the differential diagnosis of other diseases showing severe abdominal pain. 10.3748/wjg.v24.i32.3637
    Spontaneous hemoperitoneum resulting from segmental arterial mediolysis. Olivares Emily,Vingan Harlan,Zhou Qiao Radiology case reports Segmental arterial mediolysis is a rare but potentially life-threatening arteropathy of medium to large arteries that can be managed with endovascular treatment for patients who are hemodynamically unstable. We present a case of segmental arterial mediolysis in a 73-year-old woman who developed spontaneous hemoperitoneum in the emergency department after initially presenting with unrelated upper respiratory complaints. Her initial computed tomography revealed an aneurysm arising off the right hepatic artery. She was taken to the interventional radiology suite for embolization and multiple aneurysms along the right hepatic artery were identified that had the appearance of segmental arterial mediolysis. She initially stabilized but then developed acute renal failure and had a decrease in hemoglobin on postprocedure day 2. She was taken back to the angiography suite where multiple small left gastric and left hepatic trunk aneurysms were identified, with a small area of extravasation evident. The vessel was coiled from the liver to the origin of the left gastric artery. She was discharged and had a follow-up angiogram 2 months later, which showed interval development of an aneurysm to the distal right hepatic artery. 10.1016/j.radcr.2017.11.019
    Segmental Arterial Mediolysis: Abdominal Imaging of and Disease Course in 111 Patients. Naidu Sailen G,Menias Christine O,Oklu Rahmi,Hines Robert S,Alhalabi Kinan,Makar Gerges,Shamoun Fadi E,Henkin Stanislav,McBane Robert D AJR. American journal of roentgenology OBJECTIVE:The purpose of this study is to identify the imaging characteristics of segmental arterial mediolysis (SAM) at presentation and establish the longitudinal course of disease. MATERIALS AND METHODS:We retrospectively identified patients with SAM at a single institution from 2000 through 2015. Diagnosis was based on published guidelines with multidisciplinary consensus. Imaging studies obtained at initial evaluation were reviewed to evaluate imaging findings and vascular territory distribution. All subsequent follow-up imaging studies were reviewed to assess for progression, stability, or regression. RESULTS:We identified 111 patients (79 men and 32 women; median age, 51 years) who met the diagnostic criteria for SAM. Abdominal pain was the most common presentation (74%), followed by flank pain (21%). SAM most commonly affected the renal arteries (47%), superior mesenteric artery (46%), celiac trunk (46%), hepatic artery (23%), iliac arteries (18%), and splenic artery (14%). The most common imaging findings were dissection (86%), aneurysm (57%), beading or webs (28%), occlusion (19%), and a rind or wall thickening (15%). The 247 available follow-up imaging studies for 97 patients (median follow-up, 12 months) showed progression in 19 patients (20%), with either stability or regression observed in the remaining patients. CONCLUSION:SAM most commonly affects the renal arteries, superior mesenteric artery, and celiac artery. Dissections and aneurysms are the most common imaging findings. Follow-up imaging studies show stability or regression in most patients. 10.2214/AJR.17.18309
    Segmental Arterial Mediolysis in Pigs Presenting With Renal Infarcts. Leifsson P S,Slavin R E Veterinary pathology Segmental arterial mediolysis, a rare arteriopathy first reported in humans, is described in the kidneys of 36 pigs slaughtered in an abattoir in Jutland, Denmark. The kidney changes presented themselves macroscopically as one or more cortical wedge-shaped hemorrhagic or pale lesions. The arterial lesions involved the interlobar and arcuate arteries and exhibited injurious and reparative phases of development. Two types of injurious lesions occurred: (1) a tearing separation of the outer media from the adventitia with fibrin, erythrocytes, and edema fluid filling the formed space, causing collapse of the arterial wall, and (2) outer and mid-medial foci showing irregularly bordered cytoplasmic vacuolar change containing membranous and organelle debris or smooth muscle shrinkage with nuclear loss. In the reparative phase, granulation tissue filled and expanded tear sites and zones of arterial medial muscle loss and extended into the adventitia and through the intima into the arterial lumen. Sequelae, including dissecting hematomas and arterial occlusions causing renal infarcts, were found. Although repartitioning agents widely used in animal husbandry in many countries may potentially cause segmental arterial mediolysis, no such link could be identified. The causation of segmental arterial mediolysis in these pigs is currently unknown but is being further investigated. 10.1177/0300985814568360
    Segmental arterial mediolysis. Pillai Anil Kumar,Iqbal Shams I,Liu Raymond W,Rachamreddy Niranjan,Kalva Sanjeeva P Cardiovascular and interventional radiology Segmental arterial mediolysis (SAM) is an uncommon, nonatherosclerotic, noninflammatory, large- to medium-sized arteriopathy first described in 1976. It is characterized histologically by vacuolization and lysis of the outer arterial media leading to dissecting aneurysms and vessel rupture presenting clinically with self-limiting abdominal pain or catastrophic hemorrhages in the abdomen. Patients of all ages are affected with a greater incidence at the fifth and sixth decades. There is a slight male predominance. Imaging findings overlap with inflammatory vasculitis, collagen vascular disease, and fibromuscular dysplasia. The presence of segmental dissections involving the celiac, mesenteric, and/or renal arteries is the key distinguishing features of SAM. Inflammatory markers, genetic tests for collagen vascular disorders, and hypercoagulable studies are negative. Anti-inflammatory agents and immunosuppressants are not effective. A mortality rate of 50 % has been attributed to the acute presentation with aneurysmal rupture necessitating urgent surgical or endovascular treatments; in the absence of the acute presentation, SAM is a self-limiting disease and is treated conservatively. There are no established guidelines on medical therapy, although optimal control of blood pressure is considered the main cornerstone of medical therapy. The long-term prognosis is not known. 10.1007/s00270-014-0859-4
    Segmental arterial mediolysis. Chao Christine P Seminars in interventional radiology Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly. Computed tomography (CT) and angiography imaging findings overlap with various vasculitides and include segmental changes of aneurysm and stenosis. A key distinguishing feature is the presence of dissections, the principle morphologic expression of SAM. Differentiation and exclusion of an inflammatory arteritis is crucial in appropriate management, as immunosuppressants generally used for treatment of vasculitis may be ineffective or even worsen the vasculopathy. Although the disease can be self-limiting without treatment or with conservative medical therapy, the acute process carries a 50% mortality rate and may necessitate urgent surgical and/or endovascular therapy. Prompt recognition and diagnosis are therefore of utmost importance in appropriate management of this rare entity. 10.1055/s-0029-1225666
    Segmental arterial mediolysis--an iatrogenic vascular disorder induced by ractopamine. Slavin Richard E,Yaeger Micheal J Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology BACKGROUND:Segmental arterial mediolysis, an uncommon arterial disorder most often occurring in the splanchnic muscular arteries of the abdomen, is a cause of catastrophic hemorrhages. Its histology and initial clinical presentations suggested that it represented a localized norepinephrine-induced vasospastic response to perturbations in vascular tone and blood volume distribution caused by coexisting vasoconstrictor conditions. However, later presentations were at odds with some aspects of this hypothesis. METHODS:Nine greyhound dogs were administered a single dose of ractopamine. Two dogs developing persistent conduction abnormalities with biochemical evidence of heart injury were euthanized and necropsied--one 4 days and the other 17 days after dosage This report is based on findings and comparisons of the canine abdominal and coronary arteries to segmental arterial mediolysis. RESULTS:Lesions having features of early-injurious-stage segmental arterial mediolysis were identified in the canine arteries 4 days postractopamine, and arteries examined after 17 days showed alterations typically occurring in reparative-stage segmental arterial mediolysis. It is suspected that ractopamine, a Beta-2 adrenergic agonist, created segmental arterial mediolysis by neuromodulating the peripheral sympathetic nervous system to release norepinephrine from varicosities of efferent nerves serving splanchnic arteries that stimulate alpha-1 receptors to induce injury at the adventitial medial junction and medial muscle apoptosis. CONCLUSION:This finding and other cited examples suggest that segmental arterial mediolysis may be a disorder principally caused by iatrogenic or accidental exposure to alpha-1 adrenergic receptor agonists or Beta-2 agonists able to release norepinephrine from the peripheral nervous system. 10.1016/j.carpath.2011.09.003
    Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases. Skeik Nedaa,Olson Sydney L,Hari Gopika,Pavia Mary L Vascular medicine (London, England) Segmental arterial mediolysis (SAM) is a rare but serious nonatherosclerotic, noninflammatory vasculopathy of unknown etiology that often results in dissection, aneurysm, occlusion, or stenosis of, primarily, the abdominal arteries. Current literature lacks consensus on diagnostic criteria and management options for SAM. This review summarizes 143 cases and aims to advance appropriate recognition and management of SAM. Literature review of all relevant SAM case studies from 2005 to 2018 yielded 126 individual SAM cases from 66 reports. We identified 17 additional SAM cases from our center, bringing our analysis to 143 patients. Patients with SAM were most commonly men (68%) in their 60s. Hypertension (43%), tobacco use (12%), and hyperlipidemia (12%) were common comorbidities. Abdominal pain (80%) and intraabdominal bleeding (50%) were the most common presenting symptoms. Computed tomography was the most frequently used imaging method (78%), and histology was available in 44% of cases. The most commonly affected vessels were the superior mesenteric (53%), hepatic (45%), celiac (36%), renal (26%), and splenic (25%) arteries with aneurysm (76%), dissection (61%), and arterial rupture (46%). Treatments included coil embolization (28%), abdominal organ surgery (24%), open arterial repair (21%), and medical management (20%). Case-specific treatment modalities yielded symptom relief in the vast majority (91%) of patients, with a mortality rate of 7%. 10.1177/1358863X19873410
    Longitudinal Evaluation of Segmental Arterial Mediolysis in Splanchnic Arteries: Case Series and Systematic Review. Kim Hyun Soo,Min Sang-Il,Han Ahram,Choi Chanjoong,Min Seung-Kee,Ha Jongwon PloS one BACKGROUND:Segmental arterial mediolysis (SAM) is a rare non-atherosclerotic, non-inflammatory vascular disorder varying widely in clinical course. The purpose of this study is to analyze detailing clinical and imaging manifestations over time in patients with SAM through a literature review and to suggest an optimal management strategy. METHODS:A retrospective review of eight consecutive patients diagnosed with SAM between January, 2000 and January, 2012 was conducted. All presented with acute-onset abdominal or flank pain. Clinical features, imaging studies, and laboratory findings served as grounds for diagnosis, having excluded more common conditions (ie, fibromuscular dysplasia, collagen vascular disorders, or arteritis). CT angiography was done initially and repeated periodically (Week 1, Month 3, then yearly). Treatment was conservative, utilizing endovascular intervention as warranted by CT diagnostics. In a related systematic review, all English literature from 1976 to 2015 was screened via the PubMed database, assessing patient demographics, affected arteries, clinical presentations, and treatment methods. FINDINGS:Ultimately, 25 arterial lesions identified in eight patients (median age, 62.8 years; range, 40-84 years) were monitored for a median period of 26 months (range, 15-57 months). At baseline, celiac axis (3/8, 37.5%), superior mesenteric (4/8, 50%), and common hepatic (2/8, 25%) arteries were involved, in addition to isolated lesions of right renal, splenic, right colic, middle colic, gastroduodenal, left gastric, right gastroepiploic, proper hepatic, right hepatic, and left hepatic arteries. Compared with prior publications, celiac axis and superior mesenteric artery were more commonly affected in cohort. Arterial dissections (n = 8), aneurysms (n = 5), stenoses or occlusions (n = 4), and a single pseudoaneurysm were documented. Despite careful conservative management, new splanchnic arterial lesions (n = 4) arose during follow-up. Considering the few available reports of new arterial lesions in the literature, newly developing pathology is a distinctive feature of our patients, four of whom eventually required endovascular interventions. CONCLUSIONS:Careful clinical observation via periodic CT angiography is required in patients with SAM, checking for newly developing lesions. The natural history of SAM should be clarified in a larger patient population. 10.1371/journal.pone.0161182