Multidetector CT appearances of splanchnic arterial pathology

Spontaneous Renal Artery Dissection as a Cause of Acute Renal Infarction: Clinical and MDCT Findings

The purpose of this study was to assess the incidence of spontaneous renal artery dissection (SRAD) as a cause of acute renal infarction, and to evaluate the clinical and multidetector computed tomography (MDCT) findings of SRAD. From November 2011 to January 2014, 35 patients who were diagnosed with acute renal infarction by MDCT were included. We analyzed the 35 MDCT data sets and medical records retrospectively, and compared clinical and imaging features of SRAD with an embolism, using Fisher's exact test and the Mann-Whitney test. The most common cause of acute renal infarction was an embolism, and SRAD was the second most common cause. SRAD patients had new-onset hypertension more frequently than embolic patients. Embolic patients were found to have increased C-reactive protein (CRP) more often than SRAD patients. Laboratory results, including tests for lactate dehydrogenase (LDH) and blood urea nitrogen (BUN), and the BUN/creatinine ratio (BCR) were significantly higher in embolic patients than SRAD patients. Bilateral renal involvement was detected in embolic patients more often than in SRAD patients. MDCT images of SRAD patients showed the stenosis of the true lumen, due to compression by a thrombosed false lumen. None of SRAD patients progressed to an estimated glomerular filtration rate < 60 mL/min/1.73 m² or to end-stage renal disease during the follow-up period. SRAD is not a rare cause of acute renal infarction, and it has a benign clinical course. It should be considered in a differential diagnosis of acute renal infarction, particularly in patients with new-onset hypertension, unilateral renal involvement, and normal ranges of CRP, LDH, BUN, and BCR.

A Case of Superior Mesenteric Artery Aneurysm Mimicking an Abdominal Aortic Aneurysm and Presenting as a Pulsating Abdominal Mass

A 62-year-old male with a smoking history of 30 pack-years presented with a 1-year history of a periumbilical pulsating mass. He had been treated for hypertension for 2 years. Physical examination revealed a huge pulsating mass in the periumbilical abdomen. Femoral and popliteal arterial pulses were palpable. Computed tomography showed arterial dissection in the proximal segment of the superior mesenteric artery, a huge aneurysm (52×50 mm) with mural thrombus and two smaller aneurysms (20×20 mm) in the right ileocolic and ileal branches, along with atherosclerotic changes. Interposition using the great saphenous vein was performed after aneurysmal isolation and ligation of jejunal branches in the sac. Distal flow was reestablished by end-to-end and end-to-side anastomoses of the right ileocolic and ileal branches, respectively. No complications were observed at 1-year follow-up.

Therapeutic management of superior mesenteric artery aneurysms

OBJECTIVE

Superior mesenteric artery (SMA) aneurysms are rare but life-threatening entities. This study summarizes our experience in providing therapeutic management for true aneurysms of the SMA.

METHODS

Between February 1998 and March 2010, 10 patients were diagnosed with true SMA aneurysms in our hospital. Medical data for demographics, clinical presentation, diagnosis, aneurysm characteristics, treatment modalities, outcomes, and follow-up were retrospectively analyzed.

RESULTS

Ten patients (six women, four men) were enrolled with a mean age of 56.7 years (range, 42-69 years). One patient (10%) had aneurysm rupture and presented with abdominal pain, and seven (70%) were asymptomatic. The size of nonruptured aneurysms ranged from 1.2 to 8.0 cm (mean, 3.5 cm). Of 10 patients, five received endovascular stent graft repair, two were treated surgically, two were observed, and one with aneurysm rupture died of hemorrhagic shock before surgery. The two surgical patients underwent SMA reconstruction after aneurysmectomy, and segmental bowel resection was performed in one patient after reconstruction. The overall mortality rate was 10%. Postoperative gastroparesis was identified in one patient (14.3%). Mean operation time was 3.6 hours in the surgical group and 1.3 hours in the endovascular group. Mean postoperative hospital stay for the two groups was 20.0 days and 2.2 days, respectively. Mean follow-up was 30.9 months (range, 3-72 months). Endoleak was found in one patient 3 months after endovascular repair.

CONCLUSION

True SMA aneurysms are uncommon entities with definite rupture risk and mortality. Compared with surgical intervention, endovascular stent graft placement is associated with less trauma and rapid recovery. It may be a promising alternative to surgical intervention. The most appropriate treatment depends on the characteristics of the lesion and the condition of the patient.

Diagnosis of ruptured superior mesenteric artery aneurysm mimicking a pancreatic mass

Aneurysms and pseudoaneurysms of the superior mesenteric artery are potentially lethal and should be treated as urgently as possible. In a 52-year-old man with occasional epigastric pain, we accidentally discovered a superior mesenteric artery aneurysm that was ruptured with spontaneous tamponade in the uncinate process and in the head of the pancreas. The ruptured aneurysm had a heterogeneous appearance due to its thrombotic and hemorrhagic content, and it simulated a voluminous mass in the head and uncinate process of the pancreas, associated with mild dilatation of the main pancreatic duct. Recent advances in multidetector computed tomography and magnetic resonance imaging have enabled radiologists to develop a correct diagnosis of mesenteric aneurysms and pseudoaneurysms of the visceral branches of the abdominal aorta, and to differentiate this diagnosis from that of pancreatic or peripancreatic masses; angiography is currently used to confirm a diagnosis and to develop therapeutic treatments.

Acute abdominal vascular emergencies

Abdominal vascular emergencies are relatively uncommon, frequently catastrophic, and highly lethal. Despite improved understanding of the pathophysiology and natural history of these disorders, delays in diagnosis and treatment remain the most important factors contributing to the observed high mortality. A high index of clinical suspicion together with a sound understanding of the clinical presentation, natural history, and management of these disorders are critical to improving outcomes. This article focuses on abdominal vascular emergencies presenting with acute visceral ischemia or catastrophic intra-abdominal hemorrhage.