Segmental arterial mediolysis of the middle colic artery: report of a case with special reference to lesions of small arteries and veins

We report a case of segmental arterial mediolysis (SAM) that involved the middle colic artery, and present some pathologic alterations found in mesenteric small arteries and veins. The patient, a 52-year-old woman, underwent an emergency laparotomy for acute intra-abdominal hemorrhage, and a segment of the transverse colon with hemorrhagic mesocolon was excised. Microscopic examination demonstrated two separate lesions of SAM in the middle colic artery. The involved arterial segments showed a partial to circumferential loss of the media (mediolysis) and intima associated with the formation of a pseudoaneurysm. Smooth muscle cells adjacent to the mediolysis showed various degenerative changes. In addition, we found multiple, tiny foci of degenerative lesions affecting the outer media in the wall of small arteries. Subendothelial vacuoles and nodular intimal proliferation were also noted in small veins. Whereas SAM chiefly affects large or medium-sized arteries, small blood vessels, including veins, are also affected. The present case is unusual in that degeneration of medial smooth muscle cells was clearly observed in the arterial walls, and the small veins were affected by lesions similar to those in arteries. We suspect that a phenotypic modulation of vascular smooth muscle cells induced by some genetic vulnerability plays a role in the pathogenesis of SAM.     

Berry splenic artery aneurysm rupture in association with segmental arterial mediolysis and portal hypertension

A rare case of berry splenic artery aneurysm (SAA) rupture associated with segmental arterial mediolysis (SAM) and portal hypertension is reported. A 66-year-old woman, diagnosed as having liver cirrhosis and portal hypertension 6 years earlier, suddenly developed a lancinating pain in the upper abdomen and lost consciousness. She recovered consciousness while being transferred to hospital by ambulance. During the investigations, her level of consciousness suddenly deteriorated. Ultrasonography showed a massive intraperitoneal hemorrhage, and she died 5(1/2) h after admission. On gross examination at autopsy it was not possible to find the rupture point of the vessel because the pancreas was embedded in a massive hematoma. However, careful dissection of the pancreatic tail after fixation revealed a berry aneurysm measuring 0.8 cm in diameter in a branch adjacent to the bifurcation in the distal third of the main splenic artery. Microscopic examination detected a rupture of the aneurysm. The histology of the arterial wall proximal to the aneurysm showed typical SAM. In general, berry SAA caused by SAM is rare and unlikely to rupture. The SAA in the present case likely occurred and ruptured due to the combination of SAM and portal hypertension.     

Aneurysms of the renal arteries associated with segmental arterial mediolysis in a case of polyarteritis nodosa

This is the first report of segmental arterial mediolysis (SAM) accompanied with polyarteritis nodosa (PN), and manifesting aneurysms of the renal arteries. A 73-year-old woman was admitted to hospital because of a high fever. Laboratory tests showed leukocytosis with increased CRP level in the serum. Myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA) and proteinase 3 (PR3)-ANCA were negative. There were no signs indicating infection or malignancy. After admission renal function rapidly deteriorated. Treatment was then started with daily oral prednisolone and hemodialysis. On the 40th day of hospitalization the patient suddenly became comatose. Cranial CT showed a subarachnoid hemorrhage. The patient died and an autopsy was performed. The pathological findings showed necrotizing vasculitis of the small arteries in various organs, but not associated with that of arterioles or renal glomerular lesions, indicating PN. Unexpectedly, the segmental arteries of the bilateral kidneys showed vascular lesions of dissecting aneurysms, indicating SAM. This case indicates that SAM is one of the causes of aneurysms in PN and is clinically important when the clinical course of PN patients rapidly advances.     

Simultaneous transesophageal echocardiography and atrial pacing: assessment of the functional significance of coronary artery disease before surgical treatment of an abdominal aneurysm

Conventional active stress tests for the evaluation of coronary artery disease are not feasible for patients in whom a significant blood pressure increase during a stress procedure should be avoided, for example, those with a coexisting aortic aneurysm. Transesophageal echocardiography (TEE) with simultaneous atrial pacing is a new, highly specific, and sensitive stress technique for the detection of coronary artery disease. Furthermore, TEE can be performed safely with only mild blood pressure increases. Therefore in the present case report of a 70-year-old male, application of combined TEE and atrial pacing was used successfully to exclude the hemodynamic significance of a circumflex artery stenosis and avoided a significant blood pressure increase before surgical correction of an abdominal aortic aneurysm.Abbreviations AAA Abdominal aortic aneurysm - TEE transesophageal echocardiography Correspondence to: H.U. Stempfle     

Variations of the arterial pattern in the upper limb revisited: a morphological and statistical study, with a review of the literature

A total of 192 embalmed cadavers were examined in order to present a detailed study of arterial variations in the upper limb and a meta-analysis of them. The variable terminology previously used was unified into a homogenous and complete classification, with 12 categories covering all the previously reported variant patterns of the arm and forearm.     

Morphogenesis of the primary arterial trunks of the forelimb in the rat embryos: the trunks originate from the lateral surface of the dorsal aorta independently of the intersegmental arteries

It has been believed that the primary arterial trunk of the mammalian forelimb is derived from the 7th intersegmental artery. Here we examined the early morphogenesis of the arteries and nerves in the forelimb region by adopting a method that combined intravascular dye-injection with nerve staining to whole mounted rat embryos. The study was carried out on greater numbers of specimens at smaller intervals of embryonic stages and from earlier stages than those in previous reports. We report that: (1) The multiple primary arterial trunks in the forelimb region (primary subclavians) originate directly from the lateral surface of the dorsal aorta independently of the intersegmental arteries, previous to the formation of limb buds. (2) The tips of the 8th (and the 9th) primary subclavians that originate from the aorta near the origin of the 8th (or the 9th) intersegmental artery bend cranially and/or caudally. With the formation of limb bud, they extend to form the longitudinal trunks in the presumptive axillary region. The primary arteries in the free arm region branch off from this longitudinal trunk, and one of them develops into the axial artery. (3) The origins of the primary subclavians shift their positions on the surface of the dorsal aorta and approach the origins of the neighboring intersegmental arteries to join them, and then replace the latter. Consequently, the primary subclavians appear to be ”the lateral branches of the in tersegmental arteries.” (4) The 8th primary subclavian is dominant at first, but is replaced by the 7th primary subclavian, which develops into the definitive subclavian artery. (5) With the brachial nerve plexus formation, the axillary arterial plexus derived from the longitudinal trunk develops to form two stems of the axillary artery. Accepted: 15 April 1999     

Common stem origin of left gastric,right and left inferior phrenic arteries,in association with a hepatosplenomesenteric trunk,independently arising from the abdominal aorta: Case report using MDCT angiography

We describe in this paper a rare case of a 45‐year‐old male with a common stem origin of the left gastric artery (LGA), right inferior phrenic artery (RIPA), and left inferior phrenic artery (LIPA), in association with the presence of a hepatosplenomesenteric trunk (HSMT) arising from the abdominal aorta (AA), as revealed by routine multidetector computed tomography (MDCT) angiography. The common stem origin of the LGA, RIPA, and LIPA had an endoluminal diameter of 3.3 mm, the LGA of 2.8 mm. The endoluminal diameter of the RIPA and LIPA was at the origin of approximately 1 mm, complicating selective chemoembolization of the liver parenchyma. Clin. Anat. 26:980–983, 2013. © 2012 Wiley Periodicals, Inc.