Abhisekh Mohapatra

Autologous alternative veins may not provide better outcomes than prosthetic conduits for below-knee bypass when great saphenous vein is unavailable

BACKGROUND There is a need to better define the role of alternative autologous vein (AAV) segments over contemporary prosthetic conduits in patients with critical limb ischemia when great saphenous vein (GSV) is not available for use as the bypass conduit. METHODS Consecutive patients who underwent bypass to infrageniculate targets between 2007 and 2011 were categorized in three groups: GSV, AAV, and prosthetic. The primary outcome was graft patency. The secondary outcome was limb salvage. Cox proportional hazards regression was used to adjust for baseline confounding variables. RESULTS A total of 407 infrainguinal bypasses to below-knee targets were analyzed; 255 patients (63%) received a single-segment GSV, 106 patients (26%) received an AAV, and 46 patients (11%) received a prosthetic conduit. Baseline characteristics were similar among groups, with the exception of popliteal targets and anticoagulation use being more frequent in the prosthetic group. Primary patency at 2 and 5 years was estimated at 47% and 32%, respectively, for the GSV group; 24% and 23% for the AAV group; and 43% and 38% for the prosthetic group. Primary assisted patency at 2 and 5 years was estimated at 71% and 55%, respectively, for the GSV group; 53% and 51% for the AAV group; and 45% and 40% for the prosthetic group. Secondary patency at 2 and 5 years was estimated at 75% and 60%, respectively, for the GSV group; 57% and 55% for the AAV group; and 46% and 41% for the prosthetic group. In Cox analysis, primary patency (hazard ratio [HR], 0.55; P < .001; 95% confidence interval [CI], 0.404-0.758), primary assisted patency (HR, 0.57; P = .004; 95% CI, 0.388-0.831), and secondary patency (HR, 0.56; P = .005; 95% CI, 0.372-0.840) were predicted by GSV compared with AAV, but there was no difference between AAV and prosthetic grafts except for the primary patency, for which prosthetic was protective (HR, 0.38; P < .001; 95% CI, 0.224-0.629). Limb salvage was similar among groups. CONCLUSIONS AAV conduits may not offer a significant patency advantage in midterm follow-up over prosthetic bypasses.

Peroneal bypass versus endovascular peroneal intervention for critical limb ischemia

Objective: The peroneal artery is a well‐established target for bypass in patients with critical limb ischemia (CLI). The objective of this study was to evaluate the outcomes of peroneal artery revascularization in terms of wound healing and limb salvage in patients with CLI. Methods: Patients presenting between 2006 and 2013 with CLI (Rutherford 4‐6) and isolated peroneal runoff were included in the study. They were divided into patients who underwent bypass to the peroneal artery and those who underwent endovascular peroneal artery intervention. Demographics, comorbidities, and follow‐up data were recorded. Wounds were classified by Wound, Ischemia, foot Infection (WIfI) score. The primary outcome was wound healing; secondary outcomes included mortality, major amputation, and patency. Results: There were 200 limbs with peroneal bypass and 138 limbs with endovascular peroneal intervention included, with mean follow‐up of 24.0 ± 26.3 and 14.5 ± 19.1 months, respectively (P = .0001). The two groups were comparable in comorbidities, with the exception of the endovascular groups having more patients with cardiac and renal disease and diabetes mellitus but fewer patients with smoking history. Based on WIfI criteria, ischemia scores were worse in bypass patients, but wound and foot infection scores were worse in endovascular patients. Perioperatively, bypass patients had higher rates of myocardial infarction (4.5% vs 0%; P = .012) and incisional complications (13.0% vs 4.4%; P = .008). At 12 months, the bypass group compared with the endovascular group had better primary patency (47.9% vs 23.4%; P = .002) and primary assisted patency (63.6% vs 42.2%; P = .003) and a trend toward better secondary patency (74.2% vs 63.5%; P = .11). There were no differences in the rate of wound healing (52.6% vs 37.7% at 1 year; P = .09) or freedom from major amputation (81.5% vs 74.7% at 1 year; P = .37). In a multivariate analysis, neuropathy was associated with improved wound healing, whereas WIfI wound score, cancer, chronic renal insufficiency, and smoking were associated with decreased wound healing. Treatment modality was not a significant predictor (P = .15). Conclusions: Endovascular peroneal artery intervention results in poorer primary and primary assisted patency rates than surgical bypass to the peroneal artery but provides similar wound healing and limb salvage rates with a lower rate of complications. In appropriately selected patients, endovascular intervention to treat the peroneal artery is a low‐risk intervention that may be sufficient to heal ischemic foot wounds.

Bypass versus endovascular intervention for healing ischemic foot wounds secondary to tibial arterial disease

Objective: Pedal (inframalleolar) bypass is a long‐standing therapy for tibial arterial disease in patients with ischemic tissue loss. Endovascular tibial intervention is an appealing alternative with lower risks of perioperative mortality or complications. Our objective was to compare the effectiveness of these two treatment modalities with respect to patency and limb‐related clinical outcomes. Methods: We performed a retrospective chart review of patients presenting between 2006 and 2013 with ischemic foot wounds and infrapopliteal arterial disease who underwent a revascularization procedure (either open surgical bypass to an inframalleolar target or endovascular tibial intervention). Data were collected on baseline demographics and comorbidities, procedural details, and postprocedure outcomes. The primary outcome was successful healing of the index wound, with mortality, major amputation, and patency assessed as secondary outcomes. Results: We identified 417 patients who met our eligibility criteria; 105 underwent surgical bypass and 312 underwent endovascular intervention, with mean follow‐up of 25.0 and 20.2 months, respectively (P = .08). The endovascular patients were older at baseline (P = .009), with higher rates of hyperlipidemia (P = .02), prior cerebrovascular accidents (P = .04), and smoking history (P = .04). Within 30 days postoperatively, there was no difference in mortality (P = .31), but bypass patients had longer hospital length of stay (P < .0001), higher rate of discharge to nursing facility (P < .001), and higher rates of myocardial infarctions (P = .03) and wound complications (P < .001). At 6 months, the rate of wound healing was 22.4% in the bypass group compared with 29.0% in the endovascular group (P = .02). At 1 year, survival was higher after bypass (86.2% vs 70.4%; P < .0001), but freedom from major amputation was similar (84.9% vs 82.8%; P = .42). Primary patency (53.1% vs 38.2%; P = .002) and primary assisted patency (76.6% vs 51.7%; P < .0001) were higher in the bypass group, but there was no difference in secondary patency (77.3% vs 73.8%; P = .13). Conclusions: Endovascular tibial intervention is associated with poorer primary patency but similar secondary patency and wound healing rates compared with the “gold standard” of surgical bypass to a pedal target. In patients with tibial arterial disease, endovascular intervention should be considered a lower risk alternative to pedal bypass that provides similar clinical outcomes.

Risk factors for perioperative mortality after revascularization for acute aortic occlusion

Objective: Acute aortic occlusion (AAO) is a life‐threatening event necessitating prompt revascularization to the pelvis and lower extremities. Because of its uncommon nature, outcomes after revascularization for AAO are not well characterized. Our aim was to describe the perioperative morbidity and mortality associated with revascularization and to identify the patients at highest risk. Methods: A retrospective chart review was performed of patients who presented to our institution from 2006 to 2017 with acute distal aortic occlusion. Patients with a prior aortofemoral bypass were excluded, but those with aortoiliac stents were included. Baseline demographics and comorbidities, preoperative clinical presentation and imaging, procedural details, and postoperative hospital course were reviewed. The primary outcome was 30‐day mortality, and major complications were evaluated as secondary outcomes. Logistic regression models were constructed to identify factors associated with 30‐day mortality. Results: We identified 65 patients who underwent revascularization for AAO. Median age was 63 years (range, 35‐89 years), and 64.6% were male; 56.4% of patients presented within 24 hours of symptom onset, and 43.8% were treated within 6 hours of presentation. There were particularly high rates of prior coronary artery disease (62.3%) and chronic obstructive pulmonary disease (41.0%); 18.5% had prior iliac stents. Preoperative imaging in 44 patients showed occlusion of the inferior mesenteric artery in 36.0% and both internal iliac arteries in 34.7%. Treatments for revascularization included axillobifemoral bypass (55.4%), aortoiliac thromboembolectomy (15.4%), aortobifemoral bypass (13.9%), and aortoiliac stenting (15.4%). Overall 30‐day mortality was 27.7% and was not affected by treatment modality. Mortality was highest in patients older than 60 years (40.5% vs 10.7%; P = .01) and those presenting with lactate elevation (45.5% vs 5.9%; P = .004) or motor deficit in at least one extremity (36.6% vs 9.5%; P = .03). Univariate predictors of 30‐day mortality were age ≥60 years (odds ratio [OR], 5.68; 95% confidence interval [CI], 1.45‐22.26; P = .01), presentation with motor deficit (OR, 5.48; 95% CI, 1.12‐26.86; P = .04), presentation with elevated lactate level (OR, 13.33; 95% CI, 1.58‐11.57; P = .02), history of prior stroke (OR, 4.80; 95% CI, 1.21‐18.97; P = .03), and bilateral internal iliac artery occlusion (OR, 7.11; 95% CI, 1.54‐32.91; P = .01). At least one postoperative complication was observed in 78.5% of patients, including acute kidney injury (56.9%, with 21.5% requiring hemodialysis), respiratory complications (46.2%), cardiovascular complications (33.9%), major amputation (15.4%, bilateral in 7.7%), and bowel ischemia (10.8%). Conclusions: Even with prompt revascularization and despite the chosen treatment modality, AAO carries high risk of mortality and numerous life‐threatening complications. Older patients presenting with elevated lactate levels, motor deficit, and bilateral internal iliac artery occlusions are at the highest risk of perioperative mortality. These factors may aid in risk stratification and managing expectations in this critically ill population.

Acute aortic occlusion secondary to aortic endograft migration and collapse

Endograft migration after endovascular aneurysm repair (EVAR) is known to predispose to type Ia endoleaks and aneurysm growth but rarely leads to ischemic complications. We describe the case of a patient who presented with acute limb ischemia secondary to endograft collapse and subsequent aortic occlusion. Informed consent was obtained from the patient. The patient, a 75-year-old man, underwent EVAR with an AneuRx device (Medtronic, St. Paul, Minn) at an outside institution. Postoperative computed tomography demonstrated good endograft position and aneurysm exclusion (A). He was subsequently lost to follow-up. Four years later, he presented to the outside institution with bilateral lower extremity weakness. Additional past medical history included coronary artery disease and chronic obstructive pulmonary disease due to a 75 pack-year smoking history. Computed tomography angiography was performed and showed significant migration of the proximal endograft into the aneurysm sac, with subsequent kinking and complete occlusion of the graft (B-D). At the time of transfer to our institution, the lower extremities were pulseless and insensate below the knee, with complete paralysis of the right leg and significant paresis of the left leg. He was taken to the operating room emergently and underwent an axillobifemoral bypass with bilateral femoral artery thrombectomies and lower leg fasciotomies. On completion, he had return of pedal pulses bilaterally. After a prolonged hospitalization, he was discharged to a skilled nursing facility in good condition. At 1-year follow-up, he was ambulating with minimal assistance and had a widely patent bypass graft by duplex ultrasound imaging. Aortic endograft collapse is rare and is primarily described in the thoracic aorta. Four cases of abdominal aortic endograft collapse after EVAR have been reported to date, two resulting in type Ia endoleak and one resulting in graft occlusion and lower extremity ischemia. Factors predisposing to graft collapse after EVAR are unknown but likely include both anatomic and endograft-specific factors. In this patient, neck degeneration and lack of active proximal endograft fixation likely contributed to migration of the endograft into the aneurysm sac and subsequent collapse. This case emphasizes the need for ongoing surveillance after EVAR to prevent such complications.

VESS13. Peroneal Bypass vs Endovascular Peroneal Intervention for Critical Limb Ischemia

(87.2% vs 67.7%; P 1⁄4 .001), and patients on dialysis (3.0% vs 0.0%; P 1⁄4 .009, Table I). There were fewer patients with comorbid coronary artery disease (32.3% vs 47.3%; P 1⁄4 .005). The CC includedmore patients who had undergone prior aortoiliac endovascular intervention that had failed (17.3% vs 4.8%; P 1⁄4 .0001), and there was a nonsignificant trend toward an increased number of patients undergoing AFB for critical limb ischemia (50.4% vs 40.7%; P 1⁄4 .07) as opposed to claudication symptoms. Overall and major morbidity were similar in both cohorts (Table II). Thirty-day mortality was similar and <1% in both cohorts, but 10-year survival was higher in the CC (67.7% vs 52.6%; P 1⁄4 .02). Ten-year primary patency was higher in the HC (75.8% vs 90.8%; P 1⁄4 .02), but secondary patency and limb salvage were similar in both cohorts, with the latter >95% in both cases. Conclusions: In the contemporary era, patients undergoing AFB for AOD are more likely to have undergone aortoiliac endovascular intervention, and to be females, smokers, and have comorbid dialysisdependent end-stage renal disease. Although long-term primary patency is lower among patients in the CC, during which a substantial subset of AOD patients are being treated primarily via the endovascular approach, secondary patency and limb salvage have not worsened, and long-term survival has increased. These changing characteristics should be considered when benchmarking for reintervention rates and other outcomes.