Effect of ischemia-reperfusion on outcomes after open mesenteric bypass for chronic mesenteric ischemia.

OBJECTIVE: Significant physiologic perturbations can occur in patients with chronic mesenteric ischemia (CMI) undergoing open mesenteric bypass (OMB). These events have frequently been attributed to ischemia-reperfusion events and have been directly implicated in the occurrence of multiple organ dysfunction (MOD). Scoring systems (MOD score [MODS] and sequential organ failure assessment [SOFA]) have been derived within the critical care field to provide a composite metric for these pathophysiologic changes. The purpose of the present study was to describe the early pathophysiologic changes that occur after OMB for CMI and determine whether these are predictive of the outcomes. METHODS: Patients with CMI who had undergone elective OMB from 2002 to 2018 at a single institution were reviewed. Changes in the hemodynamic, pulmonary, hepatic, renal, and hematologic parameters in the first 96 hours postoperatively were analyzed. The MODSs and SOFA scores were calculated. Cox regression was used to determine the association of the MODSs and SOFA scores with the outcomes. RESULTS: The use of OMB was analyzed for 72 patients (age, 66 ± 11 years; 68% women; body mass index, 23.8 ± 6 kg/m2; 48 ± 34-lb weight loss in 59%). Previous mesenteric stent placement or bypass had been performed in 39% [stenting in 21; bypass in 8; (one patient had both)]. An antegrade configuration (93%) was most common (retrograde configuration, 7%), with revascularization of the superior mesenteric artery/celiac vessels in 85% (superior mesenteric artery only in 15%). Postoperative pathophysiologic and metabolic changes were common, and the mean MODSs and SOFA scores were 3.6 ± 2.4 (range, 1-10) and 4.0 ± 2.7 (range, 1-13), respectively. The median length of stay was 14 days (interquartile range, 9-21). The 30-day mortality was 4% (n = 3) and in-hospital morbidity was 53% (n = 38; gastrointestinal, 25%; infectious, 22%; cardiac, 18%; pulmonary, 18%; renal, 11%). The clinical follow-up period was 16 ± 20 months. The MODSs and SOFA scores correlated linearly with overall mortality (MODS: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; P < .01; SOFA score: OR, 1.4; 95% CI, 1.2-1.7; P < .01 per unit), with a score of ≥5 the inflection point most predictive of mortality (MODS: OR, 3.9; 95% CI, 1.6-9.9; P ≤ .01; SOFA score: OR, 2.8; 95% CI, 1.2-6.6; P = .02). The 1- and 3-year primary bypass patency and freedom from reintervention was 91% ± 5% and 83% ± 7%, respectively, with no association with the MODSs or SOFA scores. The 1- and 3-year survival was 86% ± 4% and 71% ± 6% with significantly worse outcomes for patients with higher MODSs and/or SOFA scores. CONCLUSIONS: Most CMI patients undergoing OMB will experience significant metabolic derangements resulting from sequelae of the ischemia-reperfusion phenomenon postoperatively. These can be objectively assessed in the early postoperative period using simply applied scoring systems to reliably predict the early and long-term outcomes. A derivation of the MODS and/or SOFA score after OMB for CMI can identify the most vulnerable patients at the greatest risk of mortality.

Contemporary outcomes of thoracofemoral bypass.

OBJECTIVE: Thoracofemoral bypass (TFB) is an alternative to aortofemoral bypass (AFB) or extra-anatomic bypass for severe aortoiliac occlusive disease (AIOD). TFB may be particularly useful in select patients with concurrent visceral aortic branch vessel disease, infrarenal aortic occlusions, or after failed AFB. However, there are few contemporary series describing the indications and outcomes for TFB. Therefore, the purpose of this analysis was to review our experience with TFB. METHODS: All patients undergoing TFB for occlusive disease from 2002 to 2017 were reviewed. All patients underwent left thoracoretroperitoneal exposure of the supraceliac aorta with division of the diaphragmatic crus and supraceliac cross-clamping. An end-to-side aortic anastomosis was created and each graft limb was tunneled in the retroperitoneum to the femoral bifurcation. Adjunctive visceral/infrainguinal revascularization was performed selectively based on symptoms, end-organ function, and/or preoperative imaging. The primary end points were major complications and 30-day mortality. Secondary end points included limb patency, freedom from major adverse limb events, and survival. Kaplan-Meier methodology was used to characterize the end points. RESULTS: Forty-one patients (age 61 ± 9 years; 54% female; 7% in a hypercoaguable state) underwent TFB. The mean preoperative ankle-brachial index was 0.4 bilaterally. Indications included critical limb ischemia (56%), claudication (30%), acute limb ischemia (7%), and combined AIOD and mesenteric ischemia (7%). Seven patients (17%) had previously undergone AFB and 15 (38%) had previously undergone any prior aortic operation. Adjunctive visceral bypass occurred in 8 patients (20%; N = 14 grafts, n = 6 renal, n = 5 superior mesenteric artery, and n = 3 celiac). The postoperative duration of stay was 11 days (interquartile range [IQR], 7-16 days) and the 30-day mortality was 5% (n = 2). Major complications occurred in 34% of patients (N = 14; pulmonary, 15%; cardiac, 12%; bleeding, 7%; accidental splenectomy, 5%; renal, 5%; wound, 2%). The mean postoperative ankle-brachial index was 0.9 bilaterally. At a median follow-up of 7 months (IQR, 1-17 months), 5 patients (12%) underwent some form of reintervention (graft/limb related, n = 4 [n = 2 graft thrombosis, n = 2 graft infection], n = 1 mesenteric bypass revision). The estimated 3-year primary limb patency and freedom from major adverse limb events were 80 ± 10%, and 70 ± 10%, respectively. The estimated 5-year survival was 93 ± 5% (median, 27.3; IQR, 14.5-35.2; 95% confidence interval, 17.9-32.8). CONCLUSIONS: This experience represents one of the largest and most current series of retroperitoneal TFB. We demonstrate that TFB can be performed with good outcomes for patients with severe AIOD, especially if concomitant visceral/infrainguinal reconstruction is warranted. These results support a continued role for TFB in select patients.

Outcomes of antegrade and retrograde open mesenteric bypass for acute mesenteric ischemia.

BACKGROUND: Acute mesenteric ischemia (AMI) is a challenging clinical problem associated with significant morbidity and mortality. Few contemporary reports focus specifically on patients undergoing open mesenteric bypass (OMB) or delineate outcome differences based on bypass configuration. This is notable, because there is a subset of patients who are poor candidates for endovascular intervention including those with flush mesenteric vessel occlusion, long segment occlusive disease, and a thrombosed mesenteric stent and/or bypass. This analysis reviewed our experience with OMB in the treatment of AMI and compared outcomes between patients undergoing either antegrade or retrograde bypass. METHODS: A single-center, retrospective review was performed to identify all patients who underwent OMB for AMI from 2002 to 2016. A preoperative history of mesenteric revascularization, demographics, comorbidities, operative details, and outcomes were abstracted. The primary end point was in-hospital mortality. Secondary end points included complications, reintervention, and overall survival. Kaplan-Meier estimation and Cox proportional hazards regression were used to analyze all end points. RESULTS: Eighty-two patients (female 54%; age 63 ± 12 years) underwent aortomesenteric bypass (aortoceliac/superior mesenteric, n = 44; aortomesenteric, n = 38) for AMI. A history of prior stent/bypass was present in 20% (n = 16). A majority (76%; n = 62) underwent antegrade bypass and the remainder received retrograde infrarenal aortoiliac inflow. Patients receiving antegrade OMB were more likely to be male (53% vs 25%; P = .02), have coronary artery disease (48% vs 25%; P = .06), chronic obstructive pulmonary disease (52% vs 25%; P = .03), and peripheral arterial disease (60% vs 35%; P = .05). Concurrent bowel resection was evenly distributed (antegrade, 45%; retrograde, 45%; P = .9) and 37% (n = 30) underwent subsequent resection during second look operations. The median duration of stay was 16 days (interquartile range, 9-35 days) and 78% (n = 64) experienced at least one major complication with no difference in rates between antegrade/retrograde configurations. In-hospital mortality was 37% (n = 30; multiple organ dysfunction, 22; bowel infarction, 4; hemorrhage/anemia, 2; arrhythmia, 1; stroke, 1; 30-day mortality, 26%). The median follow-up was 8 months (interquartile range, 1-26 months). The 1- and 3-year primary patency rates were both 82% ± 6% (95% confidence interval, 71%-95%), with 10 patients requiring reintervention. Estimated survival at 1 and 5 years was 57% ± 6% and 50% ± 6%, respectively. Bypass configuration was not associated with complication rates (P > .10), in-hospital mortality (log-rank, P = .3), or overall survival (log-rank, P = .9). However, a higher risk of reintervention was observed in patients undergoing retrograde bypass (hazard ratio, 3.0; 95% confidence interval, 0.9-11.0; P = .08). CONCLUSIONS: OMB for AMI results in significant morbidity and mortality, irrespective of bypass configuration. Antegrade OMB is associated with comparable outcomes as retrograde OMB. The bypass configuration choice should be predicated on patient presentation, anatomy, physiology, and surgeon preference; however, an antegrade configuration may provide a lower risk of reintervention.