Spontaneous Subdiaphragmatic Hemorrhage From an Aneurysm of Inferior Phrenic Artery.

Inferior phrenic artery (IPA) aneurysms are the rarest type of visceral aneurysms. It usually occurs secondary to trauma, surgery, or as a complication of pancreatitis. In addition, it can be a manifestation of underlying systemic pathology such as vasculitis, collagen vascular disorders, sepsis, or segmental arterial mediolysis. It can be associated with hypertension in 43% of cases. The presentation of IPA aneurysm is nonspecific with abdominal pain, melena, hematochezia, and anemia. The ruptured and actively bleeding aneurysm can lead to hemorrhagic shock, and immediate management is required with angiography and endovascular embolization with coil or gel foam or stent etc. Inaccessible locations are reached with surgical intervention, but it is associated with high morbidity and mortality. We here report a rare case of spontaneously ruptured IPA pseudoaneurysm extending from the posterior mediastinum to the subdiaphragmatic area and managed with coil and gel foam embolization.

Segmental arterial mediolysis leading to spontaneous rupture of splenic artery and fatal hemorrhage in pregnancy.

We report an unexpected death of a 22-year-old primigravida who was admitted to the hospital with sudden abdominal pain two days before a scheduled delivery. During an emergency caesarean section due to intrauterine asphyxia, intraabdominal bleeding was observed with no apparent source of bleeding. Newly formed blood clots in the subdiaphragmatic space and arterial bleeding near the splenic hilum required a surgery on the next day. Hemorrhagic shock led to multiple organ failure on the fourth day of admission. The autopsy revealed ruptured splenic artery at the pancreatic tail and near the splenic hilum. Microscopically, different stages of segmental arterial mediolysis were observed in partially thinned and aneurysmatic artery.

Segmental arterial mediolysis after fenestrated endovascular abdominal aortic aneurysm repair-A rare complication.

Segmental arterial mediolysis (SAM) is a rare, noninflammatory, nonatherosclerotic condition that occurs commonly in mesenteric vessels. There are no known predisposing risk factors to the development of SAM. We present a case of a 67-year-old woman who presented with abdominal pain 2 days following discharge after an elective endovascular abdominal aortic intervention. Repeat imaging 2 days after readmission showed the presence of multiple new aneurysms involving the mesenteric vasculature. She underwent attempted endovascular embolization of the largest aneurysm. The postmortem and histopathologic examinations confirmed the diagnosis of SAM.

A Case Report of Renal Infarcts Secondary to Segmental Arterial Mediolysis.

Flank pain is an exceptionally common presenting symptom in the emergency and primary care setting; however, most clinicians may not include a differential diagnosis of renal infarct (RI) due to the reported low incidence of this condition. Delayed diagnosis or treatment intervention for RI can have dire consequences for the patient including hypertension and longstanding renal impairment. In this report, we review a case of a previously healthy 39-year-old male presenting with flank pain, which after extensive workup, was revealed to be caused by renal infarction from a renal artery dissection secondary to segmental arterial mediolysis (SAM).

A case of rectal cancer complicated with segmental arterial mediolysis (SAM) safely treated with curative resection - A case report.

INTRODUCTION: Recent advances in diagnostic imaging techniques have led to an increasing number of case reports of segmental arterial mediolysis (SAM). However, reports of abnormalities associated with SAM of abdominal organs, including the bowel, are limited. SAM, a rare vascular disease that causes spontaneous intra-abdominal bleeding, including shock and intestinal ischemia, has been reported to be associated with high mortality, but it has not been reported to coexist with rectal cancer. CASE PRESENTATION: A 74 year-old male was referred to our hospital with a rectal cancer and he was admitted for further examination. Computed tomography angiography (CTA) revealed dissection and aneurysm in the celiac artery, superior mesenteric artery (SMA), and the inferior mesenteric artery were dilated, leading to a diagnosis of SAM. CLINICAL DISCUSSION: Surgery for rectal cancer requires cutting the inferior mesenteric artery. The risk of bleeding during surgery increases when SAM is associated with the inferior mesenteric artery. The radical surgery for rectal cancer was executed without complications, including significant bleeding. This was achieved through careful management of SAM, meticulous control of blood pressure throughout the surgical procedure, and the delicate treatment of the SMA. A pathological diagnosis of the resected inferior mesenteric artery at the time of radical surgery was performed, and a definitive diagnosis of SAM was made. CONCLUSION: We present a first known case in which high anterior resection was successfully performed for rectal cancer complicated by SAM. The relationship between cancer and SAM is unclear and further case accumulation is needed.

Gallbladder hemorrhage associated with segmental arterial mediolysis: a case report.

BACKGROUND: Gallbladder hemorrhage is a rare but fatal condition. The reported causes of gallbladder hemorrhage include iatrogenesis, atherosclerotic changes in the cystic arteries, acute cholecystitis or cholelithiasis, malignancy, trauma, hemophilia, pseudoaneurysm, and the use of oral anticoagulant medications. Recently, segmental arterial mediolysis (SAM) has been reported as a possible etiology of life-threatening abdominal, retroperitoneal, and intracranial hemorrhages. However, no previous reports have described the association between gallbladder hemorrhage and SAM. CASE PRESENTATION: A 59-year-old man was transferred to our hospital complaining of upper abdominal pain and vomiting. Contrast-enhanced computed tomography revealed high-density images of the gallbladder and common bile duct. However, there were no obvious findings of gallstones, cholecystitis, tumors, or aneurysms. He was diagnosed with gallbladder hemorrhage and bile duct obstruction. We performed a laparoscopic cholecystectomy after endoscopic biliary drainage. The gross appearance of the surgically resected specimen showed 12 small (3-12 mm), slightly elevated lesions on the gallbladder mucosa. Histologically, these slightly elevated lesions consisted of dilated muscular arteries of the gallbladder wall with fibrinoid degeneration of the media and focal loss of the internal and external elastic laminae. The histopathological diagnosis was confirmed as SAM. CONCLUSIONS: To the best of our knowledge, this is the first reported case of a gallbladder hemorrhage associated with SAM. Our case report shows that SAM can cause gallbladder hemorrhage, suggesting that SAM should be considered in the differential diagnosis of gallbladder hemorrhage.

Differentiating between segmental arterial mediolysis and other arterial vasculopathies to establish an early diagnosis - a systematic literature review and proposal of new diagnostic criteria.

Segmental arterial mediolysis (SAM) is a rare vascular disease, characterized by acute but transient vulnerability of the wall of medium-sized arteries. The most characteristic feature of SAM is its biphasic course: an injurious phase marked by acute weakness of the arterial wall leading to acute dissection and/or hemorrhage, followed by a reparative phase in which granulation tissue and fibrosis restore the injured arterial wall. Residual stenosis, aneurysms, and/or arterial wall irregularities may remain visible on future imaging studies. Differentiating between SAM and other arterial vasculopathies is difficult due to its similarities with many other vascular diseases, such as vasculitis, fibromuscular dysplasia, inherited connective tissue disorders, and isolated visceral artery dissection. In this systematic review, we provide an overview on SAM, with an emphasis on the differential diagnosis and diagnostic work-up. We propose new diagnostic criteria to help establish a prompt diagnosis of SAM, illustrated by case examples from our multidisciplinary vascular clinic.

Presentation of unruptured right gastric aneurysm due to segmental arterial mediolysis resected laparoscopically: A case report.

INTRODUCTION: Timely diagnosis and treatment of intra-abdominal arterial aneurysms before rupture are highly recommended. We successfully prevented rupture through arterial aneurysm excision, highlighting the importance of the lack of reports on resection before rupture. CASE PRESENTATION: A 60-year-old male with previous history of ureteral stones presented complaining primarily of left-sided abdominal pain. Computed tomography (CT) revealed a left ureteral stone and incidentally identified a submucosal gastric tumor and right gastric artery aneurysm, leading to referral to our department. Blood tests showed no abnormalities. CT revealed a 23-mm submucosal tumor protruding outward from the middle gastric body wall. A 13-mm aneurysm was observed in the right gastric artery, and no other aneurysms were detected, including intracranially. Upper gastrointestinal endoscopy revealed a smooth elevation covered by normal mucosa in the middle gastric body. Endoscopic ultrasound-fine needle aspiration resulted in a diagnosis of gastrointestinal stromal tumor (GIST) and surgery. We performed simultaneous surgery involving laparoscopic local resection of the gastric GIST and identification and excision of the right gastric artery aneurysm due to its enlargement (7 mm on CT conducted six years ago). The patient's postoperative course was uneventful, and he was discharged on postoperative day 6. Pathological examination confirmed a diagnosis of segmental arterial mediolysis. DISCUSSION: Intra-abdominal arterial aneurysms affect approximately 1 % of the population. Splenic artery aneurysms are the most common at 58.7 %, whereas the gastric artery and gastroepiploic artery account for only 4.7 %. CONCLUSION: Right gastric artery aneurysms are exceedingly rare, with no reported cases of successful resection before rupture.

Segmental Arterial Mediolysis and its Mimickers: A Case Report and Review of the Literature.

This case report addresses segmental arterial mediolysis (SAM), a rare non-inflammatory vasculopathy. A 51-year-old man presented at the emergency department for epigastric and left upper quadrant pain. He had a history of arterial hypertension and had recently received methylprednisolone for knee pain. Blood tests revealed elevated C-reactive protein levels at 40 mg/l and lactate dehydrogenase levels at 496 IU/ml. Abdominal computerized tomography showed arterial thickening, arterial dilatations, and dissections of the splenic and renal arteries, leading to organ ischemia. This case emphasizes the importance of considering SAM in cases of unexplained abdominal pain or suspected arteriopathy. LEARNING POINTS: Segmental arterial mediolysis (SAM) is a rare and underdiagnosed vasculopathy.SAM is a challenging diagnosis and should not be confused with vasculitis.SAM has a good prognosis with spontaneous resolution in most cases.

Endovascular treatment of an isolated iliac artery aneurysm associated with segmental arterial mediolysis.

Segmental arterial mediolysis is a noninflammatory nonatherosclerotic vasculopathy of uncertain etiology characterized by dissection and/or aneurysm formation. It affects medium-to-large arteries, primarily the celiac, superior mesenteric, and renal arteries. Iliac involvement is rare, and its specific treatment has not been described. We detail a patient who presented with intrabdominal hemorrhage from a ruptured right colic artery aneurysm. He underwent transcatheter arterial embolization followed by right hemicolectomy. Histopathology confirmed the diagnosis of segmental arterial mediolysis. Endovascular treatment of a 3-cm iliac artery aneurysm was performed 18 months later. There was successful exclusion of the aneurysm demonstrated on computed tomography angiography at 10 years.

Segmental arterial mediolysis with a ruptured visceral artery on two consecutive days.

Background: We describe a case of segmental arterial mediolysis in which a vessel ruptured on two consecutive days. Case Presentation: A 69-year-old man presented with sudden-onset abdominal pain. Computed tomography showed a hematoma in the gastric wall. The patient was discharged after the pain was relieved but returned 8 h later with abdominal pain and shock. Repeated computed tomography revealed a massive intra-abdominal hemorrhage without previous aneurysm formation. Emergency angiography and coil embolization were successfully carried out. Segmental arterial mediolysis was diagnosed after irregular vasodilated lesions were observed in multiple arteries. Conclusion: This case suggests that accurately predicting the next vessel rupture is difficult. For patients experiencing intra-abdominal bleeding with segmental arterial mediolysis, we suggest treating only ruptured aneurysms and closely following-up unruptured aneurysms.

Transarterial embolization for ruptured pancreaticoduodenal artery aneurysm due to segmental arterial mediolysis combined with median arcuate ligament syndrome: a case report.

A 75-year-old female with a history of Parkinson's disease treatment and hypertension presented at the emergency section with sudden onset of right abdominal pain. Contrast-enhanced computed tomography revealed beaded irregular stenosis and dilation of the superior mesenteric artery (SMA) and an aneurysm in the branch of the pancreaticoduodenal artery (PDA) that communicates with the common hepatic artery and SMA. Additionally, a hematoma had formed in the retroperitoneal space, and extravasation of contrast medium from the pancreaticoduodenal artery aneurysm (PDAA) into the hematoma was observed. The celiac artery (CA) was compressed by the median arcuate ligament; stenosis of the CA at its origin and dilation on the distal side were observed. Based on the imaging findings, it was diagnosed that PDAA was ruptured, SMA developed segmental arterial mediolysis (SAM), and CA developed median arcuate ligament syndrome (MALS). The ruptured PDAA was thought to be caused by SAM combined with MALS. Transcatheter arterial embolization (TAE) was performed for the ruptured PDAA. To the best of our knowledge, there have been no reports of TAE for a ruptured PDAA caused by SAM and MALS. After TAE, the PDAA did not re-rupture.

Hepatic segmental arterial mediolysis: A case report and brief literature review.

Key Clinical message: When evaluating patients with abdominal pain, it is important to consider SAM in the differential diagnosis, along with vasculitis, fibromuscular dysplasia (FMD), atherosclerosis, mycotic aneurysms, and cystic medial degeneration. Abstract: Segmental arterial mediolysis (SAM) is a rare arteriopathy which is an under-recognized and commonly missed diagnosis of abdominal pain. We report a case of a 58-year-old female who presented with abdominal pain and was misdiagnosed with a urinary tract infection. The diagnosis was made with CTA and managed with embolization. Despite appropriate intervention and close hospital monitoring, further complications were inevitable. We conclude that though literature has shown better prognosis and even complete resolution after medical and/or surgical intervention, close follow up and monitoring is needed to avoid unexpected complications.

Segmental Arterial Mediolysis Presenting as a Pancreatic Mass in a Pediatric Patient: A Case Report.

We describe a case of segmental arterial mediolysis (SAM) in a 2-year-old male who presented with symptoms of acute pancreatitis. SAM is a vascular entity of unknown etiology that involves medium-sized arteries in which the integrity of the vessel wall is compromised, resulting in increased susceptibility to ischemia, hemorrhage, and dissection. The clinical presentation is variable and can range from abdominal pain to more ominous findings of abdominal hemorrhage or organ infarction. This entity should be considered in the correct clinical setting and after other vasculopathies have been excluded. We aim to bring awareness to pediatric providers given this is a rare entity with variable presentation, which could be potentially life threatening.

Pancreaticoduodenal Artery Aneurysm Rupture Presenting as Duodenal Obstruction Successfully Treated with Early Transcatheter Arterial Embolization: A Case Report of Suspected Segmental Arterial Mediolysis.

Visceral aneurysms are a rare but important form of abdominal vascular disease. Rupture of the aneurysms leads to serious symptoms, such as acute abdomen or abdominal bleeding. However, duodenal obstruction due to arterial rupture of an aneurysm is very rare. We herein report a 50-year-old woman with suspected segmental arterial mediolysis (SAM) who was first diagnosed with acute abdomen and duodenal obstruction. Rupture of a pancreaticoduodenal artery aneurysm was confirmed, and she was treated with transcatheter arterial embolization. In cases of acute abdomen, SAM is a rare but important possibility to consider as a differential diagnosis.

A case of transcatheter arterial embolization for intraperitoneal hemorrhage due to giant hepatic segmental arterial mediolysis.

This study aimed to demonstrate the effect of transcatheter arterial embolization (TAE) on hepatic segmental arterial mediolysis (SAM). The patient, a 68-year-old female, suddenly developed right upper abdominal pain in October 2021, which was initially relieved. However, she was rushed to a local hospital the next day when her abdominal pain recurred. An abdominal computed tomography scan suggested a ruptured hepatic aneurysm; therefore, she was transferred to our hospital and admitted on the same day. On the first day after admission, she underwent emergency catheterization and N-butyl-2-cyanoacrylate (NBCA)/lipiodol embolization for an aneurysm in the hepatic S6. A multi-detector computed tomography on hospital day 8 to probe for extrahepatic lesions revealed multiple beaded irregularities in the superior mesenteric and bilateral renal arteries. A head magnetic resonance angiography performed on the ninth day showed no aneurysms or irregularities. She did well after TAE, did not have rebleeding, and was discharged on hospital day 16. Rupture of an aneurysm associated with SAM occurs frequently in the colonic and gastroepiploic arteries, and rupture of a hepatic aneurysm is relatively rare. TAE hemostasis was able to save the patient by preventing intraperitoneal bleeding caused by hepatic segmental arterial mediolysis.

Superficial temporal artery aneurysm with segmental arterial mediolysis: a case report.

Segmental arterial mediolysis (SAM) is a rare non-arteriosclerotic and non-inflammatory vascular disease. Superficial temporal artery (STA) aneurysms are usually associated with trauma, surgery, and hair transplantation. Spontaneous aneurysms of the STA are uncommon, but an STA aneurysm caused by SAM is rare. We report a 70-year-old woman with a spontaneous aneurysm of the STA. The mass in the left parietal region was pulsatile and gradually enlarged in size without any history of head trauma. The mass was successfully removed by surgery and was proved histopathologically to be a true aneurysm with SAM.

Successful coil embolization of a ruptured aneurysm of the arc of Riolan artery.

The arc of Riolan (AOR) is an anastomosis between the middle and left colic arteries. Aneurysms of the AOR are very rare visceral artery aneurysms. A 44-year-old man presented with abdominal pain and loss of consciousness. Computed tomography and angiography showed hemorrhagic ascites around the liver and spleen. An irregularly dilated artery was visible within a hematoma in the upper left region of the abdomen, consistent with a ruptured pseudoaneurysm of the AOR. Transcatheter arterial embolization was performed with microcoils. The patient's abdominal pain disappeared after embolization, and no symptoms of intestinal ischemia were observed. To our knowledge, this is the first case of an AOR aneurysm with AOR dilation due to dissection of the celiac artery that was successfully treated by coil embolization.

Intraperitoneal hemorrhage due to segmental arterial mediolysis associated with cerebral vasospasm after subarachnoid hemorrhage.

A man in his 50s with no significant past medical history developed subarachnoid hemorrhage due to ruptured left middle cerebral artery aneurysm. On the ninth hospital day, he had a ruptured visceral aneurysm with segmental arterial mediolysis, and we successfully treated with transarterial embolization using metallic coils.

Intra-abdominal hemorrhage due to segmental arterial mediolysis of an ovarian artery pseudoaneurysm and concomitant aneurysmal subarachnoid hemorrhage: illustrative case.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) is one of the most severe neurosurgical diseases in which systemic management is important from the acute phase to the chronic phase. The authors reported a case of aneurysmal SAH associated with intra-abdominal hemorrhage possibly caused by segmental arterial mediolysis (SAM). OBSERVATIONS: A 60-year-old woman collapsed suddenly at home. On arrival at our hospital, she was comatose and her head computed tomography (CT) showed SAH, probably from an anterior cerebral artery aneurysm. Simultaneous body CT to screen for pneumonia associated with COVID-19 incidentally detected an intra-abdominal hematoma and the bleeding point. Emergent ventriculostomy was conducted first. Because abdominal angiography detected a ruptured pseudoaneurysm of an ovarian artery, emergency embolization was subsequently performed for hemostasis. However, she deteriorated again, and her pupils became fully dilated. The patient died on day 3 of hospitalization. LESSONS: Patients with aneurysmal SAH rarely have intra-abdominal hemorrhage in the acute stage and may have a fatal outcome. Intra-abdominal hemorrhage should be suspected in the setting of unstable vital signs, and prompt treatment is necessary.