MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia

Chronic mesenteric ischemia: Clinical practice guidelines from the Society for Vascular Surgery

BACKGROUND

Chronic mesenteric ischemia (CMI) results from the inability to achieve adequate postprandial intestinal blood flow, usually from atherosclerotic occlusive disease at the origins of the mesenteric vessels. Patients typically present with postprandial pain, food fear, and weight loss, although they can present with acute mesenteric ischemia and bowel infarction. The diagnosis requires a combination of the appropriate clinical symptoms and significant mesenteric artery occlusive disease, although it is often delayed given the spectrum of gastrointestinal disorders associated with abdominal pain and weight loss. The treatment goals include relieving the presenting symptoms, preventing progression to acute mesenteric ischemia, and improving overall quality of life. These practice guidelines were developed to provide the best possible evidence for the diagnosis and treatment of patients with CMI from atherosclerosis.

METHODS

The Society for Vascular Surgery established a committee composed of vascular surgeons and individuals experienced with evidence-based reviews. The committee focused on six specific areas, including the diagnostic evaluation, indications for treatment, choice of treatment, perioperative evaluation, endovascular/open revascularization, and surveillance/remediation. A formal systematic review was performed by the evidence team to identify the optimal technique for revascularization. Specific practice recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation system based on review of literature, the strength of the data, and consensus.

RESULTS

Patients with symptoms consistent with CMI should undergo an expedited workup, including a computed tomography arteriogram, to exclude other potential causes. The diagnosis is supported by significant arterial occlusive disease in the mesenteric vessels, particularly the superior mesenteric artery. Treatment requires revascularization with the primary target being the superior mesenteric artery. Endovascular revascularization with a balloon-expandable covered intraluminal stent is the recommended initial treatment with open repair reserved for select younger patients and those who are not endovascular candidates. Long-term follow-up and surveillance are recommended after revascularization and for asymptomatic patients with severe mesenteric occlusive disease. Patient with recurrent symptoms after revascularization owing to recurrent stenoses should be treated with an endovascular-first approach, similar to the de novo lesion.

CONCLUSIONS

These practice guidelines were developed based on the best available evidence. They should help to optimize the care of patients with CMI. Multiple areas for future research were identified.

Air within surgical arterial graft on computed tomography-An alarming finding of a rare complication

We present a case of a 61 years old lady operated 2 years back for severe superior mesenteric artery stenosis with a surgical vascular graft and presenting as acute severe abdominal pain and vomiting. Her CT angiography showed occlusion of the surgical vascular graft with graft migration into small bowel. Both the findings of graft occlusion and bowel perforation were optimally demonstrated on the CT angiography study. The alarm of bowel perforation in addition to graft infection was raised by the presence of air pockets within the graft and its communication with bowel lumen. Coexistent graft infection was evident on graft culture.

Emergency Transcatheter Arterial Embolization for Acute Renal Hemorrhage

The aims of this study were to identify arteriographic manifestations of acute renal hemorrhage and to evaluate the efficacy of emergency embolization. Emergency renal artery angiography was performed on 83 patients with acute renal hemorrhage. As soon as bleeding arteries were identified, emergency embolization was performed using gelatin sponge, polyvinyl alcohol particles, and coils. The arteriographic presentation and the effect of the treatment for acute renal hemorrhage were analyzed retrospectively. Contrast extravasation was observed in 41 patients. Renal arteriovenous fistulas were found in 12 of the 41 patients. In all, 8 other patients had a renal pseudoaneurysm, 5 had pseudoaneurysm rupture complicated by a renal arteriovenous fistula, and 1 had pseudoaneurysm rupture complicated by a renal artery-calyceal fistula. Another 16 patients had tumor vasculature seen on arteriography. Before the procedure, 35 patients underwent renal artery computed tomography angiography (CTA). Following emergency embolization, complete hemostasis was achieved in 80 patients, although persistent hematuria was present in 3 renal trauma patients and 1 patient who had undergone percutaneous nephrolithotomy (justifying surgical removal of the ipsilateral kidney in this patient). Two-year follow-up revealed an overall effective rate of 95.18 % (79/83) for emergency embolization. There were no serious complications. Emergency embolization is a safe, effective, minimally invasive treatment for renal hemorrhage. Because of the diversified arteriographic presentation of acute renal hemorrhage, proper selection of the embolic agent is a key to successful hemostasis. Preoperative renal CTA plays an important role in diagnosing and localizing the bleeding artery.

Noninvasive biomagnetic detection of intestinal slow wave dysrhythmias in chronic mesenteric ischemia

Chronic mesenteric ischemia (CMI) is a challenging clinical problem that is difficult to diagnose noninvasively. Diagnosis early in the disease process would enable life-saving early surgical intervention. Previous studies established that superconducting quantum interference device (SQUID) magnetometers detect the slow wave changes in the magnetoenterogram (MENG) noninvasively following induction of mesenteric ischemia in animal models. The purpose of this study was to assess functional physiological changes in the intestinal slow wave MENG of patients with chronic mesenteric ischemia. Pre- and postoperative studies were conducted on CMI patients using MENG and intraoperative recordings using invasive serosal electromyograms (EMG). Our preoperative MENG recordings showed that patients with CMI exhibited a significant decrease in intestinal slow wave frequency from 8.9 ± 0.3 cpm preprandial to 7.4 ± 0.1 cpm postprandial (P < 0.01) that was not observed in postoperative recordings (9.3 ± 0.2 cpm preprandial and 9.4 ± 0.4 cpm postprandial, P = 0.86). Intraoperative recording detected multiple frequencies from the ischemic portion of jejunum before revascularization, whereas normal serosal intestinal slow wave frequencies were observed after revascularization. The preoperative MENG data also showed signals with multiple frequencies suggestive of uncoupling and intestinal ischemia similar to intraoperative serosal EMG. Our results showed that multichannel MENG can identify intestinal slow wave dysrhythmias in CMI patients.

Chronic atherosclerotic mesenteric ischemia (CMI)

Chronic mesenteric ischemia (CMI) is most likely caused by atherosclerosis and less frequently by external compression and vasculitis. Symptomatic CMI is an uncommon, potentially under-diagnosed condition caused by fixed stenoses or occlusion of, in most conditions, at least two visceral arteries. If only one of the three major bowel-providing arteries — the celiac trunk, and the superior and inferior mesenteric arteries — is affected, the patient is usually asymptomatic due to a tight collateral network. The only exception is the celiac artery compression syndrome which represents primarily a compression syndrome of celiac plexus nerves by the arcuate ligament in conjunction with a compression of the celiac trunk. CMI of atherosclerotic origin is associated with a high morbidity and mortality. During the last decade, endovascular revascularization has replaced surgical revascularization as the therapy of choice in most centers. This article reviews the most relevant clinical aspects of the disease and the current practice of diagnosis and treatment of CMI.