Direct Retrograde Bypass is Preferable to Antegrade Bypass for Open Mesenteric Revascularization

Abstract

Mesenteric bypass grafts can be constructed either antegrade or retrograde. There is debate regarding which is the optimal approach. We have modified the technique for retrograde mesenteric revascularization using a direct open retrograde revascularization (DORR) technique. This report is a retrospective single-institution study that describes the DORR technique and compares it with antegrade mesenteric bypass. The medical records of patients undergoing open mesenteric bypass between January 2001 and December 2017 for mesenteric ischemia were reviewed. Patients who underwent mesenteric thromboembolectomy, retrograde stenting, or bypass for aneurysmal disease were excluded. Patient demographics, operative details, and follow-up data were recorded. Antegrade bypasses were constructed using a polyester, collagen-coated, knitted, (Maquet, Getinge Group)- bifurcated graft. The supraceliac aorta was exposed, and the Dacron graft limbs were tunneled to the celiac and/or superior mesenteric artery (SMA). The DORR was constructed by anastomosing a vein graft to an iliac artery. The vein was tunneled through the base of the small bowel mesentery to create a direct course to the SMA. When revascularization to both the SMA and celiac vessels was indicated, the vein was anastomosed to the SMA in a side-to-side fashion with the distal vein tunneled through the mesocolon and anastomosed in a end-to-side fashion to the hepatic artery. Statistical analysis was done using Student's t-test, Mann-Whitney U test, Fisher's exact test, and log-rank test with a P≤0.05 considered significant. Forty-one patients underwent open mesenteric bypass: 16 antegrade and 25 retrograde. Patient age, gender, and body mass index were similar. Indication for operation was acute ischemia in a greater portion of patients undergoing retrograde bypass (P=0.025). For antegrade bypasses, Dacron was used in 15 and saphenous vein in 1. The DORR bypass originated from an iliac artery (21), limb of an aortofemoral graft (2), or infrarenal aorta (2). All DORR were constructed using veins (19 femoral veins and 6 greater saphenous veins). In DORR configurations, the bypass was created to only the SMA in 23 cases (92%). By comparison, in antegrade bypasses, the bypass was constructed to both the SMA and celiac arteries in all but 1 case (P<0.00001). Median operative time was significantly shorter for DORR compared with antegrade bypass (282 vs. 375min; P<0.05). Blood loss, need for second-look laparotomy, morbidity, mortality, length of stay, and discharge disposition were similar between groups. There was a shift in favor of the DORR technique in the second half of the study (4 of 15 [27%] DORR from 2001 to 2009 vs. 21 of 26 [81%] DORR from 2010 to 2017). In survivors, 57% of the antegrade cohort and 74% of the DORR cohort had documented follow-up (average, 47.5±59.9 and 28.8±31.3months, respectively). No difference was noted in survival between groups. All grafts in both cohorts were patented at follow-up. Direct tunneling of the graft under the mesentery with the DORR technique avoids concern for kinking and has shorter operative time despite the need for vein harvest. No differences were noted in long-term survival between patient groups. The use of a venous conduit makes DORR adaptable for both chronic and acute mesenteric ischemia. These factors have resulted in the DORR technique to be our preferred method for open mesenteric revascularization.