Infrainguinal Bypass Grafts Research Articles

Zinc Deficiency and Clinical Outcome After Infrainguinal Bypass Grafting for Critical Limb Ischemia.

Background: The aim of this study was to identify a relationship between zinc (Zn) deficiency and clinical outcome in patients with critical limb ischemia (CLI).Methods and Results: Forty-five limbs from 44 patients with CLI who underwent de novo infrainguinal bypass grafting (IBG) were retrospectively reviewed. The patients were divided into a Zn deficiency group (ZD group: Zn <60 µg/dL) and a Zn sufficiency group (ZS group: Zn ≥60 µg/dL). Graft patency, limb salvage (LS), amputation-free survival (AFS), and wound healing were compared between the groups. LS and AFS were examined to identify whether Zn deficiency was an independent predictor. The preoperative factors potentially predictive of Zn deficiency were also analyzed. Twenty-four limbs were categorized into the ZD group. Patients in the ZD group were more likely to have undergone hemodialysis (HD) and have lower serum albumin. The surgical procedures were not significantly different between the groups. Patency, LS, AFS, and complete wound healing rates were significantly lower in the ZD group. Zn deficiency was a negative predictor of LS. Age >75 years and HD were identified as predictors of Zn deficiency.Conclusions: Zn deficiency was associated with poor clinical outcome. Zn supplementation may improve clinical outcomes during IBG for CLI.

Contemporary Outcomes Following Infra-inguinal Bypass. A Recent Vascular Hub Exeprience

Introduction: Infra-inguinal bypass is the most common surgical procedure performed for critical lower extremity ischaemia. Outcomes in-terms of; survival, graft patency and freedom from major amputation vary significantly in the literature and are influenced by many factors including patient co-morbidity, anatomical site of bypass and choice of bypass conduit. Here is presented contemporary outcomes of all infra-inguinal bypass grafts performed at a single vascular hub between January 2015 and January 2019. Methods: This is a single centre, retrospective cohort study. Demographic, disease and procedural data was extracted from eligible cases identified within a national vascular registry (VSQIP-NVR). This was then cross-referenced with hospital episode statistic (HES) codes to ensure adequate data capture. In-house electronic records (clinical results reporting system, CRRS) were interrogated for follow up, re-intervention and survival outcome measures. Statistical analysis was performed using SPSS 25 (IBM). Survival estimates were calculated using the Kaplan-Meier method. Results: 185 Eligible infra inguinal bypass procedures were Identified. This consisted of 79 elective and 106 non-elective admissions. Mean age at surgery was 69 (±13) years. Tissue loss was present in 46%(n=85) of patients. Autologous vein was the conduit of choice in 90% (n=165) with reversed vein and in-situ vein accounting for 76% (n=143) and 14% (n=26) respectively. 87% of patients were enrolled into ultrasound surveillance. Mean duration of follow up was 42 (0-51) months. At 6 months, 1 and 3 years primary patency was 68%, 60% and 54% respectively.Mean time to first intervention was 14 months (IQR 3-22 months). 88% of all interventions to maintain patency were carried out by 24 months.At 6 months, 1 and 3 years secondary patency was 93%, 88% & 86% respectively. At 6 months, 1 and 3 years limb salvagewas 85%, 81% & 79% respectively. Estimated survival and limb salvage rates were significantly lower in non-elective procedures in comparison to elective procedures (p=0.07 & p=0.03 respectively). There was no difference in primary or secondary patency between popliteal and distal bypasses, however, limb salvage was significantly better in popliteal bypasses (p=0.03). Conclusion: Infra-inguinal bypass remains the gold standard in lower limb revascularisation. This case series highlights excellent patency and limb salvage into the medium term. We would advocate ultrasound surveillance as a significant proportion (38%) of grafts require maintenance to ensure continued patency, our data would support a surveillance period of 24-months as sufficient, 88% of all graft interventions to maintain patency were performed by 24 months. It may be possible limit graft surveillance, provided patients have been intervention free. As anticipated, patients who undergo non elective bypass are at greater risk of major amputation than their elective counterparts. Disclosure: Nothing to disclose

Smartphone-Mounted Infrared Thermography Camera to Assess Success of Open Infrainguinal Revascularisation

Introduction - Early thrombosis occurs in around 7% of infrainguinal vein bypass grafts(1). Recognition of this complication and prompt reintervention may salvage the graft and the limb. Peri-operative monitoring of graft patency is often dependent on nursing and other non specialist staff. In the presence of calf artery disease and poor runoff peripheral pulses are often impalpable and assessment of graft patency may be difficult. Frequently graft thrombosis may remain unrecognised. The aim of this study was to assess the role of a smartphone-mounted infrared thermography (IRT) camera to monitor bypass graft patency in the early postoperative period. Methods - 10 consecutive patients undergoing infrainguinal vein bypass surgery for critical ischaemia at a tertiary referral vascular unit were recruited. Thermography images of the soles of both feet were taken using a smartphone-mounted IR camera on the morning before surgery and the morning after surgery. The images taken were immediately available on the smartphone and mean temperature of four different areas of the sole based on angiosome distribution (medial heel, lateral heel, medial forefoot, lateral forefoot) and the pulps of the hallux and the third toe (when present or adjacent toe when amputated) were measured using the smartphone application. The relative change in temperature differences between the two feet between the pre and postoperative images in the six areas was then calculated. All grafts underwent duplex scanning to assess for patency in the postoperative period. Results - n 9 out of 10 cases there was a significant increase in relative temperature difference between the two feet between the pre and post operative images in all areas with the revascularised foot being warmer (mean relative change in temperature +4.47 degrees celsius). The biggest positive shifts in relative temperature occurred in the lateral forefoot and the big toe (5.6; STD 3.02; 6.23 STD 3.46). In one case the temperature difference between the two feet showed a negative shift with the treated foot being cooler (mean relative change in temperature -6.66 degrees celsius). On duplex scanning the 9 cases with a positive shift in relative temperature difference had a patent graft while the case with a negative shift had an occluded graft. This was successfully thrombectomised and the distal anastomoses revised. Visualisation of the colour palette representation of the temperature pattern of the foot alone was sufficient to identify a positive shift in the 9 cases with a patent graft as well as a negative shift in the one occluded graft. (See image) Conclusion - A smartphone mounted infrared thermography camera provides a quick, simple and relatively cheap technique for effective monitoring of infrainguinal bypass graft patency in the early postoperative period. The colour pattern representation of the temperature pattern of the foot allows non specialist staff to easily identify significant negative shifts in temperature triggering specialist assessment of graft patency.

The Relationship between Zinc Deficiency and Clinical Outcome after Infrainguinal Bypass Grafting for Critical Limb Ischemia

Introduction - Zinc (Zn) deficiency causes not only dysgeusia, but also protracted wound healing, decreased immunity, and other clinical disorders. Recently, some studies have advocated the relationship between Zn deficiency and atherosclerotic disease.1 Number of critical limb ischemia (CLI) has been increasing, due to the increase in diabetes mellitus (DM) and dialysis-dependent end stage renal failure. In DM patients, Zn excretion to urine is significantly increased by osmotic diuresis.2 In dialysis-dependent end stage renal failure, Zn is also lost through the dialysis membrane.

A comprehensive report of long-term outcomes after catheter-directed thrombolysis for occluded infrainguinal bypass grafts

ObjectiveThe objective of this study was to assess the technical and short- and long-term clinical outcomes of catheter-directed thrombolysis (CDT) with urokinase for occluded infrainguinal bypass grafts. In addition, factors associated with technical success and amputation-free survival were assessed. MethodsA retrospective analysis of a cohort of patients treated with catheter-directed urokinase-based thrombolysis for occluded infrainguinal bypass grafts was conducted between January 2000 and December 2015. Demographics, procedural data, and short- and long-term outcome data, including patency rates of the bypasses, limb salvage, and overall survival, were collected. Statistical models for clustered data were applied to assess predictive factors. ResultsIn 177 patients, 251 CDTs were performed on 204 bypasses. In 209 procedures (83.3%), the occluded bypass was reopened; clinical disappearance of ischemic symptoms occurred after 157 procedures (62.6%). Premature cessation of thrombolysis occurred in 33 procedures (13.2%), and periprocedural and postprocedural complications were noted in 91 patients (36.3%). Factors associated with long-term limb salvage are fewer vascular interventions before CDT (P = .0003), higher number of patent outflow vessels before start of CDT (P < .0001), and higher number of patent outflow vessels after CDT (P < .0001). The 1- and 5-year patency rates of bypasses after successful CDT were 64.6% and 48.9%; amputation-free survival after 1 year, 5 years, and 7 years was 81.5%, 71.3%, and 70.5%, respectively. ConclusionsClinical success after CDT was observed in 62% of procedures with an associated complication rate of 36%. Patent outflow vessels before and after CDT are factors associated with long-term limb salvage. Amputation-free survival after 5 years is 71.3%.

Outcomes after first-time lower extremity revascularization for chronic limb-threatening ischemia in insulin-dependent diabetic patients

ObjectiveHistorically, open surgical bypass provided a durable repair among diabetic patients with chronic limb-threatening ischemia (CLTI). In the current endovascular era, however, the difference in long-term outcomes between first-time revascularization strategies among patients with insulin-dependent diabetes mellitus (IDDM) is poorly understood. MethodsWe reviewed the records of all patients with IDDM undergoing a first-time infrainguinal bypass graft (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution from 2005 to 2014. We defined IDDM as use of chronic insulin administration at baseline to control blood glucose levels and recorded the most recent glycated hemoglobin value available within 3 months before the procedure and fasting blood glucose level on the day of the procedure. We compared rates of wound healing, restenosis, reintervention, major amputation, and mortality between BPG and PTA/S in our population using χ2, Kaplan-Meier, and Cox regression analyses. As a sensitivity analysis, we calculated propensity scores and employed inverse probability weighting to account for nonrandom assignment to BPG vs PTA/S. ResultsOf 2869 infrainguinal revascularizations from 2005 to 2014, 655 limbs (316 BPG, 339 PTA/S) in 580 patients fit our criteria and underwent a first-time revascularization for CLTI. Patients undergoing BPG, compared with PTA/S, were similar in age (69 vs 68 years; P = .55), had similar rates of tissue loss (87% vs 91%; P = .07) and dialysis dependence (26% vs 28%; P = .55), were less likely to be hypertensive (84% vs 92%; P < .001), and were more likely to be current smokers (21% vs 14%; P = .02). There were no differences between BPG and PTA/S patients in mean glycated hemoglobin levels (8.1% vs 8.0%; P = .51) or mean fasting blood glucose levels (158 vs 150 mg/dL; P = .18). Although total hospital length of stay was significantly longer among BPG patients (11 vs 8 days; P < .001), perioperative complications did not differ, including acute kidney injury (19% vs 23%; P = .24), hematoma (6.0% vs 3.8%; P = .20), acute myocardial infarction (1.3% vs 2.1%; P = .43), and mortality (3.8% vs 3.0%; P = .55). BPG-first patients had significantly lower unadjusted 6-month rates of incomplete wound healing (49% vs 57%) and 5-year rates of restenosis (53% vs 72%) and reintervention (47% vs 58%; all P < .05). After adjustment, multivariable analysis suggested PTA/S-first intervention to be significantly associated with higher risk of restenosis (hazard ratio, 1.9; 95% confidence interval, 1.3-2.7) and reintervention (1.9 [1.2-2.7]). These results remained robust after inverse probability weighting. ConclusionsAmong patients with IDDM and CLTI, a bypass-first strategy is associated with similar 30-day outcomes and lower restenosis and reintervention rates. These data suggest that a bypass-first approach may best serve appropriately selected, anatomically suitable patients with IDDM and pedal ischemia that requires revascularization.

Everolimus Drug-Eluting Stents Are Associated With Improved Outcomes for the Treatment of Infrainguinal Bypass Graft Stenoses

Everolimus Drug-Eluting Stents Are Associated With Improved Outcomes for the Treatment of Infrainguinal Bypass Graft Stenoses

The impact of current smoking on outcomes after infrainguinal bypass for claudication

ObjectiveAlthough smoking cessation is a benchmark of medical management of intermittent claudication, many patients require further revascularization. Currently, revascularization among smokers is a controversial topic, and practice patterns differ institutionally, regionally, and nationally. Patients who smoke at the time of revascularization are thought to have a poor prognosis, but data on this topic are limited. The purpose of this study was to evaluate the impact of smoking on outcomes after infrainguinal bypass for claudication. MethodsData from the national Vascular Quality Initiative from 2004 to 2014 were used to identify infrainguinal bypasses performed for claudication. Patients were categorized as former smokers (quit >1 year before intervention) and current smokers (smoking within 1 year of intervention). Demographic and comorbid differences of categorical variables were assessed. Significant predictors were included in adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking status for outcomes of major adverse limb event (MALE), amputation-free survival, limb loss, death, and MALE or death. Cumulative incidence curves were created using competing risks modeling. ResultsWe identified 2913 patients (25% female, 9% black) undergoing incident infrainguinal bypass grafting for claudication. There were 1437 current smokers and 1476 former smokers in our study. Current smoking status was a significant predictor of MALE (HR, 1.27; 95% CI, 1.00-1.60; P = .048) and MALE or death (HR, 1.22; 95% CI, 1.03-1.44; P = .02). Other factors found to be independently associated with poor outcomes in adjusted models included black race, below-knee bypass grafting, use of prosthetic conduit, and dialysis dependence. ConclusionsCurrent smokers undergoing an infrainguinal bypass procedure for claudication experienced more MALEs than former smokers did. Future studies with longer term follow-up should address limitations of this study by identifying a data source with long-term follow-up examining the relationship of smoking exposure (pack history and duration) with outcomes.

Outcomes After First-time Lower Extremity Revascularization for Chronic Limb-Threatening Ischemia in Insulin-Dependent Diabetic Patients

Historically, open surgical bypass provided a durable repair among diabetic patients with chronic limb-threatening ischemia (CLTI). In the current endovascular era, however, the difference in long-term outcomes between first-time revascularization strategies among patients with insulin-dependent diabetes mellitus (IDDM) is poorly understood. We reviewed all patients with IDDM undergoing a first-time infrainguinal bypass graft (BPG) or percutaneous transluminal angioplasty/stenting (PTA/S) for CLTI at our institution from 2005 to 2014. We defined IDDM as insulin administration at baseline to control blood glucose levels. We compared rates of wound healing, restenosis, reintervention, major amputation, and mortality between BPG and PTA/S using χ2, Kaplan-Meier, and Cox regression analyses. As a sensitivity analysis, we calculated propensity scores and employed inverse probability weighting to account for nonrandom assignment to BPG vs PTA/S. Of 2869 infrainguinal revascularizations from 2005 to 2014, there were 703 limbs (343 BPG, 361 PTA/S) in 682 patients that fit our criteria. BPG patients, compared with PTA/S patients, were similar in age (69 vs 68 years; P = .51), rates of tissue loss (87% vs 91%; P = .055), and dialysis dependence (25% vs 28%; P = .34); they were less likely to be hypertensive (84% vs 93%; P < .01) and more likely to be current smokers (21% vs 14%; P = .02). There were no differences between BPG and PTA/S in mean hemoglobin A1c levels (7.9 vs 8.0; P = .52) or mean fasting blood glucose levels (152 vs 156; P = .47). Perioperative complications did not differ, including acute kidney injury (20% vs 23%; P = .26), hematoma (7.3% vs 4.2%; P = .07), acute myocardial infarction (1.5% vs 2.2%; P = .46), and mortality (3.8% vs 2.8%; P = .45). Unadjusted 6-month rates of incomplete wound healing (51% vs 59%) and 5-year rates of restenosis (48% vs 64%) and reintervention (49% vs 60%) were all significantly higher after PTA/S (P < .05; Table). After adjustment, multivariable analysis suggested PTA/S-first intervention to be significantly associated with higher risk of restenosis (hazard ratio, 1.6; 95% confidence interval, 1.1-2.4) and reintervention (2.0 [1.3-3.0]); these results remained robust after inverse probability weighting. Among patients with CLTI, IDDM is associated with a high risk of adverse events. Ultimately, our data suggest that a bypass-first approach may best serve appropriately selected, anatomically suitable patients within this vulnerable population.TableFive-year outcomes of lower extremity revascularization for chronic limb-threatening ischemia (CLTI) in patients with insulin-dependent diabetes mellitus (IDDM)BPG (n = 342), %PTA/S (n = 361), %Log-rank P valueAdjusted P valueaIncomplete wound healing (6 months)5159.01.35Restenosis4864<.01.02Reintervention4960.04<.01Major amputation2827.99.90RAS events6976<.001<.001Major adverse limb events4432.21.21Mortality6471.10.20BPG, Bypass graft; PTA/S, percutaneous transluminal angioplasty/stenting; RAS, revascularization, major amputation, or stenosis.aAdjusted for procedure year, race, sex, age, coronary artery disease, hypertension, dialysis dependence, congestive heart failure, chronic obstructive pulmonary disease, ambulatory status, indication for intervention, history of smoking, femoropopliteal TransAtlantic Inter-Society Consensus (TASC) class, tibial TASC class. Open table in a new tab

Outcomes after first-time lower extremity revascularization for chronic limb-threatening ischemia between patients with and without diabetes

ObjectiveThe effect of diabetes type and insulin dependence on short- and long-term outcomes after lower extremity revascularization for chronic limb-threatening ischemia (CLTI) warrants additional study and more targeted focus. We sought to address this paucity of information by evaluating outcomes in insulin-dependent and noninsulin-dependent patients after any first-time revascularization. MethodsWe reviewed all limbs undergoing first-time infrainguinal bypass grafting (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution from 2005 to 2014. Based on preoperative medication regimen, patients were categorized as having insulin-dependent diabetes (IDDM), noninsulin-dependent diabetes (NIDDM), or no diabetes (NDM). Outcomes included wound healing; major amputation; RAS events (reintervention, major amputation, or stenosis); major adverse limb events; and mortality. Outcomes were evaluated using χ2, Kaplan-Meier, and Cox regression analyses. ResultsOf 2869 infrainguinal revascularizations from 2005 to 2014, 1294 limbs (646 BPG, 648 PTA/S) fit our criteria. Overall, our analysis included 703 IDDM, 262 NIDDM, and 329 NDM limbs. IDDM patients, compared with NIDDM and NDM patients, were younger (69 vs 73 vs 77 years; P < .001) and more often presented with tissue loss (89% vs 77% vs 67%; P < .001), coronary artery disease (57% vs 48% vs 43%; P < .001), and end-stage renal disease (26% vs 13% vs 12%; P < .001). Perioperative complications, including mortality (3% vs 2% vs 5%; P = .07), did not differ between groups; however, complete wound healing at 6-month follow-up was significantly worse among IDDM patients (41% vs 49% vs 61%; P < .001). IDDM patients had significantly higher 3-year major amputation rates (23% vs 11% vs 8%; P < .001). Multivariable analyses illustrated that compared with NDM, IDDM was associated with significantly higher risk of both major amputation and RAS events after any first-time intervention (hazard ratio, 2.0 [95% confidence interval, 1.1-4.1] and 1.4 [1.1-1.8], respectively). Similar associations between IDDM and both major amputation and RAS events were found in patients undergoing a PTA/S-first intervention (4.1 [1.3-12.6] and 1.5 [1.1-2.2], respectively), whereas IDDM in BPG-first patients was associated with only incomplete wound healing (2.0 [1.4-4.5]). Last, compared with NDM, NIDDM was associated with lower late mortality (0.7 [0.5-0.9]). ConclusionsCompared with NDM, IDDM is associated with similar perioperative and long-term mortality but a higher risk of incomplete wound healing, major amputation, and future RAS events, especially after a PTA/S-first approach. NIDDM, on the other hand, is associated with lower long-term mortality and few adverse limb events. Overall, these data demonstrate both the importance of distinguishing between diabetes types and the potential long-term benefit of a BPG-first strategy in appropriately selected IDDM patients with CLTI.

Results of Infrageniculate Bypasses Using the Profunda Femoris Artery as Inflow Source

When the common femoral artery is not accessible for infrainguinal bypass grafting, the profunda femoris artery (PFA) can be a valuable alternative inflow source for distal arterial revascularization. The purpose of this retrospective study was to evaluate the results of infrageniculate bypass grafting via the PFA as inflow source for critical limb ischemia. Between 1994 and 2016, 68 patients, 51 men of a mean age of 74years, underwent an infrageniculate arterial bypass grafting for critical limb ischemia, using the PFA as inflow site. PFA was exposed at the Scarpa's triangle in 38 patients (56%) and at its medio-crural segment in 30 patients (44%). The distal anastomosis was performed on the infragenicular popliteal artery in 33 patients (48%), the peroneal artery in 14 patients (20%), the tibioperoneal trunk in 8 patients (12%), the posterior tibial artery in 8 patients (12%), and the dorsalis pedis artery in 5 patients (8%). The graft material consisted of a reversed great saphenous vein (GSV) in 62 patients (91%) and a 6-mm polytetrafluoroethylene graft in 6 patients (9%). The median duration of follow-up was 51months (range, 6-72months). As main results, postoperative mortality and morbidity, overall late patients' survival, primary grafts' patency, and limb salvage rate were considered. Operative mortality and morbidity were 3% and 4%, respectively. Overall patients' survival, primary patency and limb salvage rate, at 36 and 60months were, respectively, 62% and 53%, 66% and 59%, and 92% and 77%. The PFA, both exposed at the Scarpa's triangle and at mid-thigh, is an excellent inflow source for infrageniculate revascularizations. It should remain an important part of the technical armamentarium of vascular surgeons, even in the endovascular era.

Invited commentary

Optimal antithrombotic management after lower extremity revascularization (both open and endovascular) remains an important area in need of better evidence. Whereas existing data support single antiplatelet therapy (generally aspirin) after lower extremity bypass, the role of oral anticoagulants (OACs) or combination therapies remains unclear. As a result, current guidelines from both the Society for Vascular Surgery1Conte M.S. Pomposelli F.B. Clair D.G. Geraghty P.J. McKinsey J.F. et al.Society for Vascular Surgery Lower Extremity Guidelines Writing GroupSociety for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication.J Vasc Surg. 2015; 61: 2S-41SAbstract Full Text Full Text PDF PubMed Scopus (238) Google Scholar and the American Heart Association2Gerhard-Herman M.D. Gornik H.L. Barett C. Barshes N.R. Corriere M.A. Drachman D.E. et al.2016 AHA/ACC guideline on the management of patients with lower extremity peripheral artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.Circulation. 2017; 135: e726-e779Crossref PubMed Scopus (523) Google Scholar recommend antiplatelet use and regard the role of OACs as uncertain. The authors undertook a propensity-adjusted analysis of Vascular Quality Initiative (VQI) registry data to examine the relationship between OAC use and patency of bypass grafts to infrapopliteal targets. As expected, OACs were more commonly used in higher risk cases. Overall, they found no significant differences in primary graft patency with OAC use, either alone or in combination with aspirin. Subset analysis suggested an association of OAC use with improved secondary patency for prosthetic grafts to tibial targets, at a cost of increased perioperative wound complications. I believe these findings generally confirm the common practice patterns of most U.S. vascular surgeons and suggest the need for further studies. With the growing array of new anticoagulant and antiplatelet therapies, a series of modest-scale prospective studies, perhaps nested within registries like the VQI, is sorely needed to define the best approach. An equally important question is how we are to go about obtaining high-quality evidence, given the costs and complexities of the “gold standard” randomized clinical trial. Why is it even important to accurately measure and compare patency of lower extremity revascularizations? There are two critical reasons. First, it is important to know if the operations we perform and devices we implant function as intended and for how long so that we can have informed risk-benefit discussions with patients across a range of complexity. This information also drives further innovation and improvement. Second, the linkage between vessel patency and patient-oriented end points in peripheral arterial disease is fundamentally important and inadequately understood. The VQI provides a critical tool for vascular research with an infrastructure of data collection across hundreds of institutions. However, it must be further improved to address important questions about procedural durability. Poor compliance with long-term follow-up (eg, one-third of VQI subjects missing 1-year data), lack of consistent protocols for interval graft surveillance across VQI sites, and softer definitions of patency (pulse examination in VQI vs imaging gold standard) raise questions about the accuracy of patency data derived from the VQI at present. Investment in this area would be worthwhile for our specialty and may provide a much needed, cheaper alternative to randomized clinical trials with appropriate study designs. Comparative effectiveness of anticoagulation on midterm infrainguinal bypass graft patencyJournal of Vascular SurgeryVol. 66Issue 2PreviewTherapeutic anticoagulation (AC) is used clinically for prolongation of infrainguinal bypass patency, but evidence for the efficacy of this practice is conflicting. The objective of our study was to determine the association of AC with bypass graft primary patency. Full-Text PDF Open Archive

Cryopreserved saphenous vein as a last-ditch conduit for limb salvage

ObjectiveIn patients lacking autogenous vein suitable for infrainguinal bypass, cryopreserved saphenous vein (CSV) allograft (CryoLife, Inc, Kennesaw, Ga) may be an acceptable alternative. The purpose of this study was to examine outcomes of CSV conduit for infrainguinal revascularization. MethodsBetween February 2008 and August 2015, 70 patients underwent infrainguinal bypass grafts in 73 limbs using CSV. All patients lacked suitable arm or leg vein. Demographic data and patient outcomes were retrospectively collected using electronic medical records. ResultsThe mean age of our cohort was 70 ± 14 years, and 36 (51%) were male; 47 (67%) were white, 39 (56%) had coronary artery disease, 27 (39%) had diabetes, 56 (80%) had hypertension, and 50 (71%) were former or current smokers. Median follow-up was 304 days (interquartile range, 130-991 days). Indications for the index operation included rest pain (27%), tissue loss (55%), and prosthetic graft infection (18%); 62 of 73 (85%) bypasses were performed for critical limb ischemia, and 45 of 73 (62%) were redo operations. Distal targets included superficial femoral artery or popliteal (38%), tibial (55%), and pedal (7%). All grafts had a minimum diameter of 3 mm. At 30 days, 55 of 64 grafts (86%) were patent; 9 were lost to early follow-up. The only significant risk factors associated with 30-day failure were ABO mismatch (43% vs 10%; P = .05) and donor blood type B or AB (40% vs 9%; P = .03). Estimated overall 1-year primary patency was 35%. In a multivariate analysis, nonblack race (P = .05), donor B or AB blood type (P = .01), and bypass to a tibial or pedal target (P = .05) were independently associated with loss of primary patency. There were 20 (27%) major amputations, and all grafts in these limbs had occluded at the time of amputation. Of the 33 limbs with ischemic tissue loss that had long-term follow-up, 17 of 33 (52%) went on to graft occlusion, 10 of 33 (30%) had a major amputation, and 24 of 33 (73%) had complete healing of the index wound. ConclusionsIn the setting of a multidisciplinary team with aggressive wound care, CSV may be a reasonable choice for infrainguinal revascularization in patients with ischemic tissue loss who lack autogenous conduit. However, poor midterm to long-term patency suggests that optimal selection of patients is needed to derive meaningful clinical benefit.

Comparative effectiveness of anticoagulation on midterm infrainguinal bypass graft patency

ObjectiveTherapeutic anticoagulation (AC) is used clinically for prolongation of infrainguinal bypass patency, but evidence for the efficacy of this practice is conflicting. The objective of our study was to determine the association of AC with bypass graft primary patency. MethodsClinical and comorbid data of patients undergoing infrainguinal bypass grafts to a below-knee target with at least 1 year of follow-up performed from 2003 to 2015 were obtained from the Society for Vascular Surgery Vascular Quality Initiative. Inverse propensity of treatment-weighted Cox regression was used to assess the effect of AC on patency in the total cohort while adjusting for clinical, operative, and comorbid differences between treatment groups. Subgroup analyses of distal targets and conduit type were performed. Perioperative complications were analyzed using propensity-weighted logistic regression. ResultsWe identified 7612 bypass grafts with intact 1-year follow-up information from 2003 to 2015. The mean age was 67.5 ± 11.2 years; 30.5% (n = 2320) were female, and 28.6% (n = 2165) were discharged on therapeutic AC. The anticoagulated group had a higher rate of tibial, ankle, and pedal targets (52.1% [n = 1127] vs 47.6% [n = 2269]; P < .001), had a greater use of non-single-segment vein conduits (44.3% [n = 951] vs 26.5% [n = 1426]; P < .001), and was more likely to have had a previous ipsilateral bypass (27.2% [n = 589] vs 14.7% [n = 794]; P < .001) or stent (25.4% [n = 550] vs 20.9% [n = 1130]; P < .001). Estimated unadjusted primary patency was 70.8% ± 0.6% at 1 year and lower for anticoagulated bypasses (66.9% ± 1.2% vs 72.4% ± 0.7%; P < .001). Propensity-weighted analysis showed no significant association of AC with primary patency in the overall cohort (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.86-1.11; P = .8) but demonstrated a trend toward improvement of primary patency in those with a non-single-segment vein conduit to a below-knee popliteal target (HR, 0.85; 95% CI, 0.80-1.02; P = .09). AC was associated with significantly improved secondary patency in those with prosthetic bypass grafts (HR, 0.77; 95% CI, 0.62-0.96; P = .02) or prosthetic bypasses to an infrapopliteal target (HR, 0.72; 95% CI, 0.54-0.97; P = .02). Odds of postoperative wound complications were significantly higher in those receiving AC (odds ratio, 1.33; 95% CI, 1.11-1.61; P = .002). ConclusionsThis study does not demonstrate a significant impact of therapeutic AC on primary patency for infrainguinal bypass grafts. Treatment with AC may benefit secondary patency in those with a prosthetic bypass, especially to an infrapopliteal target, but at an increased risk of postoperative wound complications.

Follow-up and surveillance of vein grafts: when and how to intervene to prevent complications.

Despite advances in endovascular strategies, surgical infrainguinal lower limb revascularization remains the gold standard treatment for critical lower limb ischemia and disabling claudication. Maintaining patency of infrainguinal vein bypass grafts has been a challenging task for vascular surgeons as they are prone to developing stenoses which may precipitate failure of the bypass. Duplex ultrasound scanning has evolved as the investigation of choice to identify vein graft lesions but graft surveillance programs using this technique remain controversial. The rationale for graft surveillance is that intervention in a patent but failing graft results in improved long-term patency and limb salvage rates compared to rescue of an occluded graft. The six-week postoperative Duplex ultrasound scan is important in identifying flow abnormalities that can predict the natural history of a vein graft and the outlook for the limb in the medium term. There are multiple factors influencing vein graft failure, which means guidelines should be flexible in terms of when and which type of intervention to the graft is optimum. Patency and durability favour open surgical revision over endovascular intervention but this must be counter balanced by the increased morbidity associated with surgical revision.

Cryopreserved Saphenous Vein: Last-Ditch Conduit for Limb Salvage?

In patients lacking autogenous vein suitable for infrainguinal bypass, cryopreserved saphenous vein (CSV) allograft (CryoLife Inc, Kennesaw, Ga) may be an acceptable alternative. However, long-term follow-up is lacking. The purpose of this study was to examine outcomes of CSV conduit for infrainguinal revascularization. Between February 2008 and August 2015, 72 patients underwent infrainguinal bypass grafts in 75 limbs using CSV. All patients were treated by a multidisciplinary limb preservation team and lacked suitable arm or leg vein. Demographic data and patient outcomes were retrospectively collected using electronic medical records. The mean age of our cohort was 70 ± 14 years, and 37 of 72 (51%) were male; 47 of 72 (65%) were white, 39 of 72 (54%) had coronary artery disease, 29 of 72 (40%) had diabetes, 57 of 72 (79%) had hypertension, and 52 of 72 (72%) were former or current smokers. Median follow-up was 304 days (interquartile range, 130-1051 days). Indications for the index operation included claudication (2%), rest pain (25%), tissue loss (53%), and prosthetic graft infection (17%); 62 of 75 (83%) bypasses were performed for critical limb ischemia, and 46 of 75 (61%) were revision operations. Distal targets included superficial femoral artery/popliteal (39%), tibial (54%), and pedal (7%). All grafts had a minimum diameter of 3 mm. At 30 days, 57 of 66 grafts (86%) were patent; 9 were lost to early follow-up. The only significant risk factor associated with 30-day failure was ABO mismatch (3 of 7 patients [43%] compared with 6 of 59 [10%]; P = .046). Estimated primary patency was worse in the tibial/pedal group (27%) compared with those bypasses to the superficial femoral artery/popliteal target (46%) (Fig). There were 20 (27%) major amputations, and all grafts in these limbs had occluded at the time of amputation. Of the 32 limbs with ischemic tissue loss that had long-term follow-up, 16 of 32 (50%) went on to graft occlusion, 9 of 32 (28%) had a major amputation, and 23 of 32 (72%) had complete healing of the index wound. The use of CSV for infrainguinal revascularization should be discouraged in patients with disabling claudication or rest pain. However, with an aggressive multidisciplinary approach including vigilant wound care and lack of autologous options, CSV may yield acceptable limb salvage. Avoiding ABO mismatch may improve 30-day graft patency.

Stenting as a bail-out option after failed percutaneous transluminal angioplasty in infrainguinal vein bypass grafts.

To study the safety and efficacy of bare and covered stents in infrainguinal vein grafts after failure of PTA for treating graft stenoses. An analysis of a prospective database of all patients who underwent stenting of infrainguinal vein bypass grafts at this institution between 1 January 2008 and 31 December 2012 was carried out. The main outcome considered was primary patency, which was reported at 1, 6 and 12 months. A total of 18 patients with a mean age of 73 years (range: 56 to 86) were included. The indications for stent placement were significant recoil (7, 39%), graft rupture (6, 33%), residual vein cusps (3, 17%) and aneurysmal degeneration (2, 11%). There was a high overall technical success rate of 94% (17/18) and arrest of haemorrhage was achieved in all cases of graft rupture. The primary patency at 1, 6 and 12 months was 89%, 71% and 59%, respectively. The use of bare and covered stents in infrainguinal vein grafts appears safe and effective. They are an excellent bail-out option for the treatment of graft rupture and give acceptable short-term results.

Fibrinolytic effects of peroneal nerve stimulation in patients with lower limb vascular disease.

Patients with lower limb vascular disease are at an increased risk of thrombotic events. Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) are important components of the fibrinolytic system, responsible for clot lysis. This study aimed to establish whether peroneal nerve stimulation (PNS) could promote fibrinolysis within a cohort of vascular patients. Ethical approval was obtained for this prospective case-controlled study. Patients were randomly assigned to active stimulation or control groups. Arterial flow measurements and venous blood samples were taken bilaterally at baseline and following 45 min of PNS. ELISA analysis for plasma t-PA and PAI-1 was performed utilizing commercially available kits. Statistical analysis evaluated the changes in t-PA and PAI-1 levels from baseline for the active (device active), passive (contralateral limb) and control limbs (inactive device applied).Seventy-seven participants were recruited: 30 claudicants (25 active and five controls), 25 patients postoperative infra-inguinal bypass grafts (19 active and six controls) and 22 patients with varicose veins (17 active and five controls). t-PA levels reduced significantly in all groups; however, intergroup analysis demonstrated no statistically significant difference when comparing the active, passive and control limbs (P = 0.079). PAI-1 levels decreased by 16.2% (34.0 ng/ml, SD 52.2) in the active limbs but only 3.6% (11.4 ng/ml, SD 47.4) and 2.6% (2.7 ng/ml, SD 21.3) in the passive and control limbs, respectively (intergroup analysis P < 0.001). No relationship between changes in flow and plasma of t-PA and PAI-1 were demonstrated. Peroneal nerve stimulation may augment fibrinolysis by decreasing plasma levels of PAI-1 levels in patients with lower limb arterial and venous disease.

Comparative Effectiveness of Anticoagulation on Infrainguinal Bypass Graft Patency

Therapeutic anticoagulation is used for prolongation of infrainguinal bypass patency, but evidence for the efficacy of this practice is conflicting. The objective of our study was to determine the effects of anticoagulation on bypass graft primary patency. Clinical and comorbid data on patients receiving infrainguinal bypass grafts to a below-knee target with at least 1 year of follow-up performed from 2003 to 2015 were obtained from the Society for Vascular Surgery Vascular Quality Initiative. Inverse propensity of treatment-weighted Cox regression was used to assess the effect of anticoagulation on patency in the total cohort while adjusting for clinical, operative, and comorbid differences between treatment groups. Subgroup analyses of distal targets and conduit type were performed; conduit types included single-segment vein, prosthetic graft, and a composite non-single-segment-vein group (NSSV) defined as all prosthetic, spliced vein, and composite grafts. We identified 7612 bypass grafts with intact 1-year follow-up information from 2003 to 2015. The mean age was 67.5 ± 11.2 years; 30.5% (n = 2320) were female, and 28.6% (n = 2165) were discharged on therapeutic anticoagulation. The anticoagulated group had a higher rate of tibial/ankle/pedal targets (52.1% [n = 1127] vs 47.6% [n = 2269]; P < .001), had a greater use of NSSV conduits (44.3% [n = 951] vs 26.5% [n = 1426]; P < .001), and were more likely to have had a previous ipsilateral bypass (27.2% [n = 589] vs 14.7% [n = 794]; P < .001) or stent (25.4% [n = 550] vs 20.9% [n = 1130]; P < .001). Estimated unadjusted primary patency was 70.8% at 1 year and lower for anticoagulated bypasses (66.9% vs 72.4%; P < .001). Propensity-weighted analysis of primary patency showed no significant impact of anticoagulation on the overall cohort or in any subgroups but demonstrated a trend toward improvement of primary patency in those with an NSSV conduit to a below-knee popliteal target (Table). Patients receiving anticoagulation for an infrainguinal bypass to a below-knee target tend to have a higher rate of distal targets, NSSV conduit use, and previous ipsilateral intervention. This study does not demonstrate any significant impact of therapeutic anticoagulation on primary patency for infrainguinal bypass grafts but does suggest a trend toward benefit in patients with a prosthetic or spliced vein bypass to the below-knee popliteal artery.TableHR95% CIPTotal cohort0.980.87-1.11.80Subgroup: Single-segment vein conduit1.050.89-1.24.58Subgroup: Prosthetic conduit0.850.70-1.02.10Subgroup: Prosthetic + below-knee popliteal target0.900.69-1.18.46Subgroup: NSSV conduit0.880.74-1.05.15Subgroup: NSSV + below-knee popliteal target0.780.60-1.01.06Subgroup: NSSV + tibial/ankle/pedal target0.970.76-1.24.81CI, Confidence interval; HR, hazard ratio; NSSV, non-single-segment-vein. Open table in a new tab

Secondary interventions in patients with autologous infrainguinal bypass grafts strongly improve patency rates

To describe the patency of percutaneous transluminal angioplasty (PTA) of autologous infrainguinal bypasses at risk. This was a retrospective single-center cohort study of consecutive patients who underwent primary PTA of an infrainguinal autologous bypass at risk from January 2009 to December 2013. Duplex ultrasound surveillance was performed for at least 1 year after PTA. The primary study end point was the number of secondary interventions. Secondary end points were freedom from recurrent stenosis or bypass occlusion and the patency of the infrainguinal autologous bypass at 1 year after primary PTA. A total of 69 infrainguinal bypasses at risk in 69 patients were identified and treated with PTA. Technical success was achieved in 91%. The median follow-up was 17 months (range, 1-58 months). During follow-up, 30 bypasses (43%) remained free of significant stenosis or bypass occlusion, 29 bypasses (42%) developed recurrent stenosis, and 10 bypasses (14%) occluded. Rates of primary assisted, and secondary patency at 1 year were 84%, and 86%. Five (7%) major amputations were performed, all after bypass occlusion. Secondary interventions after PTA of a bypass at risk are common. However, repeated secondary interventions of autologous infrainguinal bypasses at risk result in patency rates of more than 80% at 1 year.