Infrainguinal Bypass Research Articles

The obesity paradox exists for perioperative complications and mortality following lower extremity arterial bypass surgery

ObjectiveThe obesity paradox refers to a phenomenon by which obese individuals experience lower risk of mortality and even protective associations from chronic disease sequelae when compared with the non-obese and underweight population. Prior literature has demonstrated an obesity paradox after cardiac and other surgical procedures. However, the relationship between body mass index (BMI) and perioperative complications for patients undergoing major open lower extremity arterial revascularization is unclear. MethodsWe queried the Vascular Quality Initiative for individuals receiving unilateral infrainguinal bypass between 2003 and 2020. We used multivariable logistic regression to assess the relationship of BMI categories (underweight [<18.5 kg/m2], non-obese [18.5-24.9 kg/m2], overweight [25-29.9 kg/m2], Class 1 obesity [30-34.9 kg/m2], Class 2 obesity [35-39.9 kg/m2], and Class 3 obesity [>40 kg/m2]) with 30-day mortality, surgical site infection, and adverse cardiovascular events. We adjusted the models for key patient demographics, comorbidities, and technical and perioperative characteristics. ResultsFrom 2003 to 2020, 60,588 arterial bypass procedures met inclusion criteria for analysis. Upon multivariable logistic regression with the non-obese category as the reference group, odds of 30-day mortality were significantly decreased among the overweight (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.53-0.78), Class 1 obese (OR, 0.65; 95% CI, 0.52-0.81), Class 2 obese (OR, 0.66; 95% CI, 0.48-0.90), and Class 3 obese (OR, 0.61; 95% CI, 0.39-0.97) patient categories. Conversely, odds of 30-day mortality were increased in the underweight patient group (OR, 1.58; 95% CI, 1.16-2.13). Furthermore, a BMI-dependent positive association was present, with odds of surgical site infections with patients in Class 3 obesity having the highest odds (OR, 2.10; 95% CI, 1.60-2.76). Finally, among the adverse cardiovascular event outcomes assessed, only myocardial infarction (MI) demonstrated decreased odds among overweight (OR, 0.82; 95% CI, 0.71-0.96), Class 1 obese (OR, 0.78; 95% CI, 0.65-0.93), and Class 2 obese (OR, 0.66; 95% CI, 0.51-0.86) patient populations. Odds of MI among the underweight and Class 3 obesity groups were not significant. ConclusionsThe obesity paradox is evident in patients undergoing lower extremity bypass procedures, particularly with odds of 30-day mortality and MI. Our findings suggest that having higher BMI (overweight and Class 1-3 obesity) is not associated with increased mortality and should not be interpreted as a contraindication for lower extremity arterial bypass surgery. However, these patients should be under vigilant surveillance for surgical site infections. Finally, patients that are underweight have a significantly increased odds of 30-day mortality and may be more suitable candidates for endovascular therapy.

Prophylactic Transversely Hemisected Sartorius Flap for High-Risk Groin Dissections in Vascular Surgery—A Case Series

Groin wound dehiscence and infection are a common complication of femoral artery exposure. In patients with prosthetic conduits placed in the groin, these complications can lead to graft infection or anastomotic dehiscence with hemorrhage. Sartorius flaps can be useful in preventing graft infections or anastomotic breakdown in the setting of wound infections. Prophylactic sartorius flaps have been suggested to be a useful adjunct in patients who are at high risk for groin complications. Standard sartorius flaps can be difficult to perform and increase the operative time. We present our experience with a modified sartorius flap, a Transversely Hemisected Sartorius (THT), which avoids dissection to the anterior superior iliac spine. Patients who received femoral artery exposure and a modified prophylactic sartorius flap were included in this case series. The Penn Groin Assessment Scale (PGAS) was calculated for each patient and our primary outcome was the rate of deep space wound infections. Fifteen patients received a THT muscle flap. The average age of the cohort was 67.5 (35-86) years. Eight (50%) were male. The mean PGAS was 2.5 (0-6). Eight (50%) groins had a prosthetic conduit underlying the flap. Four (25%) patients had infrainguinal bypass, 3 (18.8%) for femoral-femoral bypass, and 1 (6.3%) patient received aortic-bifemoral bypass. Eight (50%) patients received sartorius flap after femoral artery exposure for thromboembolectomy, endarterectomy, or access complications. Six (37.5%) patients developed superficial surgical site infections however no deep space infections or prosthetic graft excisions resulted. This procedure was effective in preventing graft infections in all patients with high-risk features for groin infection in our retrospective case series. The segmental blood supply is maintained while providing good coverage of the femoral vessels with this rotational flap.

Glycemic Variability as a Predictor of Graft Failure Following Infrainguinal Bypass for Peripheral Arterial Disease: A Retrospective Cohort Study

BackgroundGlycaemic variability (GV), measured as the change in visit-to-visit glycated haemoglobin (HbA1c), increases the risk of multiple adverse outcomes. However, the impact of GV on graft patency following infra-inguinal bypass (IIB) is unknown. A retrospective cohort study was undertaken to assess the impact of GV on graft patency. MethodA 3-year single centre retrospective case notes analysis of all people undergoing IIB between 2017-2019. Rutherford stage, graft conduit, level of bypass, procedure details, baseline demographics, co-morbidities, and GV were assessed. Time to re-intervention, ipsilateral amputation or death were recorded to determine primary patency (PP). Results106 IIB outcomes were analysed: mean (±SD) age 68.0(9.2) years; 69(65.1%) male, 37(33.9%), 75(70.8%) had DM; 46(43.4.%) underwent elective procedures.GV>9.1% was associated with significantly lower median PP than GV<9.1%, 198 [97-753.5] vs. 713 [166.5-1044.5] days (p = 0.045).On univariate analysis, GV >9.1% vs <9.1% was significantly associated with PP (HR 1.85 [CI 1.091-3.136], p = 0.022). Bypass level was also a univariate predictor, with below knee bypasses (HR 2.31 [CI 1.164-4.564], p = 0.017), and tibial (HR 2.00 [CI 1.022-3.090], p <0.043) having lower PP than above knee bypasses. On multivariate adjustment, GV >9.1% and level of bypass remained independent predictors of primary patency, HR 1.96 (95% CI:1.12-3.42, p=0.018) and HR 2.54 (95%CI:1.24-5.22, p=0.011) respectively. ConclusionsGV is an independent predictor of primary patency following infra-inguinal bypass, thus optimising GV should be a therapeutic target.

Alternative Conduits for Lower Extremity Bypass

While single-segment GSV remains the gold-standard conduit for infrainguinal bypass, several alternative options are available for use when GSV is absent in patients with CLTI requiring infrainguinal revascularization including alternative autologous vein, prosthetic conduits and cryopreserved vein grafts.

External Scaffold for Venous Graft to Treat Chronic Limb-Threatening Ischemia: Results of the FRAME Vascular Support.

Background: The surgical treatment of chronic limb-threatening ischemia and optimal conduit choice are extensively debated. The presence of suboptimal autologous material, such as varicosities or venous aneurysms, might impair long-term outcomes. Therefore, kink-resistant external supports have been advocated in the recent literature to improve the conduit quality and outcomes. This study analyzes the FRAME external support in venous ectasic grafts in patients with chronic limb-threatening ischemia. Methods: From September 2017 to September 2023, a total of sixteen patients underwent CLTI surgery with FRAME external support for venous grafts. The inclusion criteria for FRAME applications were varicose or ectasic autologous material with a diameter ≥ 4.5 and ≤ 8 mm in an isolated segment or in the entire vein and a higher risk of bypass extrinsic compression (e.g., extra-anatomical venous bypass course). Results: Technical success and intraoperative patency were achieved in all cases. At 30 days, the limb salvage and survival rates were 100%. The primary bypass patency was 93.7% due to an early graft occlusion. No graft infection was registered. In one case, dehiscence of the surgical wound was treated by surgical debridement and antibiotic therapy. Minor amputation was required in four patients. Over a median follow-up of 32 months, two occlusions were observed; one was treated with reoperation and the other with major amputation. The primary patency was 68.7% and the assisted primary patency was 75%. Limb salvage rates observed during the entire follow-up period were 87.5%. No graft infections or dilatation of the reinforced veins were registered. Conclusions: For patients with CLTI undergoing infrainguinal bypass, satisfactory results in terms of patency and limb salvage rates were achieved using the autologous venous material, even if ectasic or varicose, with the vascular external support FRAME.

Compari̇son of PTFE sutures with polypropylene sutures in suprapopliteal femoropopliteal bypass with PTFE grafts

Aim: Infrainguinal bypass surgery stands as the predominant open surgical procedure for lower limb revascularization and is reserved for cases of intermittent claudication (IC) that have proven unresponsive to maximal medical management. Polypropylene monofilament sutures have been widely used for peripheral vascular surgery operations. Aim of this study is comparing this new type of suture with propylene sutures. Material and Methods: Between January 2022 and December 2022, two cohorts who underwent suprapopliteal femoropopliteal bypass surgery, each comprising 15 patients were included in the study. In Group I (polytetrafluoroethylene (PTFE) Group), PTFE served as the suture material, whereas in Group 2 (Non PTFE Group), polypropylene sutures were employed. All preoperative demographics, perioperative and postoperative data were collected carefully. Results: All patients underwent surgical interventions due to either rest pain or ischemic ulcers. Among the 30 patients, 11 fell into Fontaine class 4, while 19 were categorized as Fontaine class 3. Out of the 30 patients, 18 received cilostazol treatment. The mean age of the patient cohort was 66.97±7.4 years, with a mean body mass index of 29.03±6.2. When we compared the two groups, no statistically significant difference was found between groups according to demographic data. In the evaluation of intraoperative data, the mean operation time was 88.7±9.37 minutes, and the mean hemostasis time was 5.8±2.8 minutes. Group I (PTFE group) exhibited significantly lower hemostasis time and drainage levels on the first and second postoperative days (p&lt;0.0001, p=0.03, and p=0.017, respectively). The use of absorbable hemostats were significantly less in PTFE suture group. Conclusion: The selection of sutures significantly influences the achievement of soft tissue approximation, reduced inflammation, suture hole leakage and capsule formation.

Infra-inguinal bypass surgery vs endovascular revascularization for chronic limb-threatening ischemia in average- and high-risk patients

ObjectiveThis study aimed to evaluate treatment outcomes after bypass surgery or endovascular therapy (EVT) in average- and high-risk patients with chronic limb-threatening ischemia (CLTI). MethodsWe retrospectively analyzed multicenter data of patients who underwent infra-inguinal revascularization for CLTI between 2015 and 2022. A high-risk patient was defined as one with estimated 30-day mortality rate ≥5% or 2-year survival rate ≤50%, as determined by the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) calculator. The amputation-free survival (AFS), limb salvage (LS), wound healing, and 30-day mortality were compared separately for the average- and high-risk patients between the bypass and EVT with propensity score matching. ResultsWe analyzed 239 and 31 propensity score-matched pairs in the average- and high-risk patients with CLTI. In the average-risk patients, the 2-year AFS and LS rates were 78.1% and 94.4% in the bypass group and 63.0% and 87.7% in the EVT group (P < .001 and P = .007), respectively. The 1-year wound healing rates were 88.6% in the bypass group and 76.8% in the EVT group, respectively (P < .001). The 30-day mortality was 0.8% in the bypass surgery and 0.8% in the EVT group (P = .996). In the high-risk patients, there was no differences in the AFS, LS, and wound healing between the groups (P = .591, P = .148, and P = .074). The 30-day mortality was 3.2% in the bypass group and 3.2% in the EVT group (P = .991). ConclusionsBypass surgery is superior to EVT with respect to the AFS, LS, and wound healing in the average-risk patients. EVT is a feasible first-line treatment strategy for high-risk patients with CLTI undergoing revascularization, based on the lack of significant differences in the 2-year AFS rate, between the bypass surgery and EVT cohorts.

O104: The “At-Risk” Infrainguinal Bypass Graft: benefit of Duplex Ultrasound Surveillance and Institutional costs of failure

Abstract Introduction The “Achilles heel” of infrainguinal surgical revascularisation (IISR) is that of restenosis. Duplex Ultrasound Surveillance (DUS) is undertaken to identify restenosis to permit intervention to maintain graft patency. We report the impact of DUS on outcomes focusing on patient- and treatment-associated costs. Methods Consecutive patients undergoing IISR at our Institution were assessed (January 2017 - December 2020). Data on DUS (1-, 6- and 12-month scans) were collated. Primary outcomes were mortality and major limb amputations (MLA) at 2-years post IISR. Grafts were defined “at-risk” if radiological evidence of significant graft stenosis or occlusion, with or without symptoms, was identified. Post IISR graft-specific Institutional costs for all patients were quantified. Results 254 patients had IISR in the observed period (196 men, median age 70yrs). Of those, 194 (76%) entered DUS, and 109 (43%) completed it. In patients who completed DUS (vs incomplete vs none), mortality was 6.4%, (vs 26.5% vs 38% respectively; p &amp;lt;0.001) and MLA rates were 6.4% (vs 12% vs 30%, p=0.174 and p&amp;lt;0.001 respectively). Managing at-risk grafts led to additional 384 cross-sectional imaging requests, 284 outpatient reviews, 933 hospital admission days and 233 open and endovascular reinterventions with a total additional NHS cost of £ 1.348.518 in 2 years. Per-patient costs were £216 (per patient, per month) for the complete DUS group vs £348 in no DUS group. Conclusion The ongoing management of IISR is associated with significant costs. Enrolment in and completion of a DUS programme is associated with improved patient outcomes and a reduction in costs.

Short-term patency of iliofemoral to tibial bypass with vascular allografts in a minority population: A retrospective analysis of a single center acute care facility.

The aim of this study was to examine the short-term patency rates and associated factors of open lower limb, iliofemoral to tibial bypass using cryopreserved saphenous vein (CSV) in a minority population at an acute care hospital in New York City. A retrospective analysis of patients undergoing infra-inguinal bypass from iliofemoral vessels to tibial arteries with CSV between March 2020-April 2022 at an acute care facility (Harlem Hospital Center, Harlem, New York) was performed. Data including patient demographics, comorbidities, type of operation, follow-up surveillance, and salvage procedures were collected. Results were presented in patency line graphs and a life table. Target limb revascularization (TLR) and amputation free survival (AFS) were also calculated. Eleven bypass procedures were included in the analysis. Patients were followed for a mean of 10.8months. Cumulative primary patency rates at 1, 6, and 12months were 72.7%, 54.5%, and 40.9%, respectively. TLR was 36.4% and the AFS was 66.67% at the mean 10.8-month follow-up. The patency rates of minority patients undergoing bypass with CSV were analyzed with creation of a life table and calculation of patency rates, TLR and AFS. The short-term primary patency rates and post-operative outcomes were found to be comparable to larger studies in non-minority cohorts. These results suggest that larger studies as well as prospective analyses and randomized controlled trials in this patient cohort and demographic are needed, as well as optimal selection of patients to determine true clinical implications.

Autologous Alternative Vein Grafts for Infrainguinal Bypass in the Absence of Single-Segment Great Saphenous Vein: A Single-Center Study

Alternative autologous veins can be used as a conduit when adequate great saphenous vein is unavailable. We analyzed the results of our infrainguinal bypasses after adopting upper extremity veins in our practice. This is a single-center observational study involving all patients whose infrainguinal bypass involved the use of upper extremity veins between April 2019, when we began using arm veins, and February2023. During the study period, 49 bypasses were done in 48 patients; mean age 68.1±9.8; men 32 (66.7%); body mass index 28.0±4.8; indications for surgery: chronic limb threatening ischemia 41 (83.7%); acute limb ischemia 3 (6.1%); complications of previous prosthetic 3 (6.1%), or autologous 2 (4.1%) bypass grafts. Vein splicing was used in 43 (87.8%) bypasses with 3-segment grafts being the most common (26; 53.1%). There were 24 (49.0%) femorotibial, 11 (22.4%) femoropopliteal, 9 (18.4%) femoropedal, and 5 (10.2%) extension jump bypass procedures. Eighteen (36.7%) operations were redo surgeries. Twenty-one (42.9%) bypasses were formed using only arm veins. The median follow-up was 12.9 months (4.5-24.2). Two bypasses occluded during the first 30 postoperative days (2/49; 4.1%). Overall 30-day, 1-year, and 2-year primary patency rates were 93.7%±3.5%, 84.8%±5.9%, and 80.6%±6.9%, and secondary patency (SP) rates were 95.8%±2.9%, 89.2%±5.3%, and 89.2%±5.3%. One-segment grafts had better patencies than 2-, 3-, and 4-segment grafts (1-year SP 100%±0% vs 87.6%±6.0%). Two-year amputation-free survival was 86.8%±6.5%; 2-year overall survival was 88.2%±6.6%. Integration of arm vein grafts in infrainguinal bypass practice can be done safely with low incidences of perioperative graft failure. One-segment grafts had better patencies than spliced vein grafts. The achieved early patency and amputation-free survival rates strongly encourage their use. In the absence of a single-segment great saphenous vein, upper extremity vein grafts should be the preferred conduit choice.

Predictors of amputation-free survival and wound healing after infrainguinal bypass with alternative conduits

ObjectiveInadequate vein quality or prior harvest precludes use of autologous single segment greater saphenous vein (ssGSV) in many patients with chronic limb-threatening ischemia (CLTI). Predictors of patient outcome after infrainguinal bypass with alternative (non-ssGSV) conduits are not well-understood. We explored whether limb presentation, bypass target, and conduit type were associated with amputation-free survival (AFS) after infrainguinal bypass using alternative conduits. MethodsA single-center retrospective study (2013-2020) was conducted of 139 infrainguinal bypasses performed for CLTI with cryopreserved ssGSV (cryovein) (n = 71), polytetrafluoroethylene (PTFE) (n = 23), or arm/spliced vein grafts (n = 45). Characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, and outcomes were recorded. Multivariable Cox proportional hazards and classification and regression tree analysis modeled predictors of AFS. ResultsWithin 139 cases, the mean age was 71 years, 59% of patients were male, and 51% of cases were nonelective. More patients undergoing bypass with cryovein were WIfI stage 4 (41%) compared with PTFE (13%) or arm/spliced vein (27%) (P = .04). Across groups, AFS at 2 years was 78% for spliced/arm, 79% for PTFE, and 53% for cryovein (adjusted hazard ratio for cryovein, 2.5; P = .02). Among cases using cryovein, classification and regression tree analysis showed that WIfI stage 3 or 4, age >70 years, and prior failed bypass were predictive of the lowest AFS at 2 years of 36% vs AFS of 58% to 76% among subgroups with less than two of these factors. Although secondary patency at 2 years was worse in the cryovein group (26% vs 68% and 89% in arm/spliced and PTFE groups; P < .01), in patients with tissue loss there was no statistically significant difference in wound healing in the cryovein group (72%) compared with other bypass types (72% vs 87%, respectively; P = .12). ConclusionsIn patients with CLTI lacking suitable ssGSV, bypass with autogenous arm/spliced vein or PTFE has superior AFS compared with cryovein, although data were limited for PTFE conduits for distal targets. Despite poor patency with cryovein, wound healing is achieved in a majority of cases, although it should be used with caution in older patients with high WIfI stage and prior failed bypass, given the low rates of AFS.

Omniflow® II biosynthetic graft offers acceptable early and mid-term outcomes in redo surgery in patients with critical limb-threatening ischemia with no available autologous vein material.

In this study, the early and mid-term outcomes of Omniflow® II (LeMaitre Vascular, Inc., Burlington, MA, USA) biosynthetic graft in redo surgery in patients with critical limb-threatening ischemia (CLTI) with no available autologous vein material were investigated with the aim to compare the outcomes obtained in "de novo" surgery versus redo surgery. From January 2018 until December 2022, data of CLTI patients from 18 centers in Italy with no autologous vein material underwent infrainguinal bypass with Omniflow® II biosynthetic graft were collected. Thirty-day outcome measures including intraoperative technical success, major morbidity, mortality, and graft patency were assessed and compared. At two-year follow-up, estimated outcomes of survival, primary patency, primary assisted patency, secondary patency, freedom from reintervention, and amputation-free survival were analyzed using Kaplan-Meier curves and compared between groups using the log-rank test. In the study period 119 CLTI patients had an infrainguinal bypass with Omniflow® II biosynthetic graft. Seventy-seven patients (64.7%) underwent bypass as "de novo" treatment (group de novo), whilst in the remaining 42 patients (35.3%) the procedure was performed as redo surgery due to occlusion and/or infection of a previous bypass graft (group redo). Two groups were homogeneous in terms of demographic, clinical, and morphological data. In group redo explantation of an infected prosthetic graft was needed in 4 cases (9.5%). Intraoperative technical success was achieved in all cases in both groups. At 30 days, the overall patency rate did not differ between the two groups (69/77, 89.6%, group de novo vs. 35/42, 83.3%, group redo; P=0.24), whilst in group redo limb loss was higher with a statistically significant different 30-day major amputation rate between the two groups (11.9% group redo vs. 1.3% group de novo; P<0.001). Overall median duration of follow-up was eight months (IQR 6-13). At two-year follow-up there were no differences between the two groups in terms of survival (67.7% group de novo vs. 55.8% group redo, P=0.53), primary patency (34.4% group de novo vs. 26.8% group redo, P=0.25), primary assisted patency (43.6% group de novo vs. 28.8% group redo, P=0.12), freedom from reintervention (64.1% group de novo vs. 68.8% group redo, P=0.98), and amputation-free survival (67.8% group de novo vs. 60% group redo, P=0.12). Secondary patency was significantly higher in group de novo (53.7% vs. 32.3%, P=0.05). During the follow-up, the overall rates of graft infection and aneurysmal degeneration were 3.4%, and 0.8%, respectively. Nevertheless, poorer early outcomes in terms of limb salvage, Omniflow® II biosynthetic graft offers acceptable ywo-year outcomes in redo surgery in CLTI patients with no available autologous vein material. Further studies with larger population sizes are needed to validate these outcomes.

Graft Failure After Revascularization for Chronic Limb-Threatening Ischaemia (CLTI) Patients: The Role of Graft Surveillance.

Introduction Failure of infrainguinal bypass grafts remains a major problem tackled by vascular surgeons despite a meticulous surgical technique. All infrainguinal bypasses should go under routine surveillance to pick the grafts at risk for the prevention of graft failure. Objectives The aim was to find out if we were adhering to the European Society of Vascular Surgery (ESVS) guidelines in the management of chronic limb-threatening ischaemia (CLTI) patients, including postoperative follow-up and to monitor whether the patients were having postoperative duplex surveillance scans to pick any graft at risk. Methods All patients who underwent infra-inguinal bypass procedures for CLTI during the last eight months (from mid-January to mid-September 2023) in our vascular unit were included. Retrospective data were collected. Results A total of 38 patients had lower limb bypass procedures over the last eight months (from 15 January till 14 September 2023). However, two femoral-femoral (fem-fem) crossovers, one Ilio-popliteal, and one pedal bypass were excluded. Thus, a total of 36 patients were included in the study (n=34). The vast majority (n=27, 79.4%) had femoro popliteal bypass anastomosing distally to above knee (AK) or below knee (BK) popliteal artery, and the rest (n=7, 20.5%) had distal bypass (fem-distal or pop-distal bypass). Moreover, 18% of patients had amputation, 15% of patients died, and 61% of the remaining patients were on surveillance. Of those, who were not on surveillance, 44% of them had graft occlusion. Conclusion Surveillance can predict graft at risk, and the graft occlusion can be prevented by appropriate intervention. Every vascular unit should have its own post-procedural follow-up strategies.

Absolute Lymphocyte Count Predicts Bypass Surgery Outcomes in Patients with Chronic Limb-Threatening Ischemia.

Objectives: The aim of this study was to evaluate the relationship between absolute lymphocyte count (ALC) and outcomes of infrainguinal bypass surgery for chronic limb-threatening ischemia (CLTI). Methods: From 2004 to 2020, 209 limbs of 189 patients who underwent infrainguinal bypass surgery for CLTI and whose ALCs were available were included. Patients with survival >2 years and limb salvage >2 years were considered discriminant groups, and an ALC cut-off value was calculated. The relationship between preoperative ALC and outcomes was evaluated. Results: Survivorship of the higher ALC group was significantly higher than that of the lower ALC group (cut-off value 1030/μL, p = 0.0009). The limb salvage rate of the higher ALC group was significantly higher than that of the lower ALC group (cut-off value 1260/μL, p = 0.0081). In the dialysis patient group (103 limbs), the limb salvage rate of the higher ALC group was significantly higher than that of the lower ALC group (cut-off value 1170/μL, p = 0.026). ALC was independently associated with limb loss in multivariate analysis. Conclusion: ALC is promising as a predictor of outcomes after bypass surgery in CLTI. In particular, ALC is expected to be useful for limb prognosis in hemodialysis patients.

Analysis Of Hospital Data on Angioplasty and Infrainguinal Bypass for Chronic Critical Ischemia of The Lower Limbs in The Last 20 Years in Brazil

Chronic Limb Ischemia (CLI) is a severe stage of peripheral arterial disease characterized by reduced blood flow to the extremities, often leading to amputations and high morbidity and mortality rates. Treatment options include open revascularization or endovascular techniques such as angioplasty, which is less invasive but requires more frequent reinterventions. This observational and retrospective study compares hospital data for open revascularization and infrainguinal angioplasty in Brazil from 2004 to 2023, using SIH/SUS and DataSUS. The analysis included costs, mortality, length of stay, character of service, and demographic distribution of procedures. During this period, 114,417 angioplasty procedures and 47,502 open revascularizations were performed, with a total expenditure of $98.5 million. The number of deaths was 1,314 for angioplasty and 1,723 for revascularization, with mortality rates of 1.3% and 3.4%, respectively. The Northeast region stood out for having a higher ratio of angioplasty to open revascularization procedures.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease.

To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass. Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited. The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores. Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative). ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

Effect of health literacy and socioeconomic deprivation on outcomes after lower limb surgical revascularisation for chronic limb-threatening ischaemia: the HeaLTHI study

Introduction: Research has suggested a relationship between health literacy, socioeconomic status and health-related outcomes. The aim of the study was to study the association between health literacy, socioeconomic status and outcomes following infra-inguinal bypass surgery for chronic limb-threatening ischaemia (CLTI). Methods: Patients with CLTI undergoing lower limb surgical bypass graft operations between January 2016 and December 2018 were included in a cross-sectional observational study. The HLS19-Q12 questionnaire categorised participant’s health literacy as inadequate, problematic, sufficient or excellent. Socioeconomic status was assessed using the Index of Multiple Deprivation (IMD). Primary outcomes were major lower limb amputation (MLLA) and adverse cardiovascular events. Secondary outcomes included length of hospital stay, and early postoperative complications including pneumonia, surgical site and graft infection. Kaplan– Meier survival curves were used to compare health literacy and amputation, and Cox proportional regression analysis was conducted to identify differences in limb loss risk against health literacy and social deprivation levels. Results: The study consisted of 50 patients with an average age of 70±8.7 years. The participants' levels of health literacy were classified as inadequate (28%), problematic (38%), sufficient (24%) or excellent (10%). Approximately 40% of the patients lived in the most deprived areas. While all health literacy groups had similar postoperative outcomes, low health literacy was connected with lower socioeconomic status (r=0.308, p=0.029). IMD (p=0.017, HR 0.502 (95% CI 0.285 to 0.883)) and haemoglobin (p=0.001, HR 0.919 (95% CI 0.872 to 0.968)) were significant predictors of MLLA. Conclusion: Patients with lower health literacy are more likely to face higher levels of social deprivation, which may predict amputation following bypass surgery. Enhancing health literacy could play a role in reducing health disparities caused by social deprivation, thereby potentially addressing a vascular James Lind Alliance priority.

Direct oral anticoagulants over warfarin at discharge associated with improved survival and patency in infra-geniculate bypasses with prosthetic conduits

ObjectiveThere is no consensus on the optimal anticoagulant regimen following lower extremity bypass. Historically, warfarin has been utilized for prosthetic or compromised vein bypasses. Direct-acting oral anticoagulants (DOACs) are increasingly replacing warfarin in this context, but their efficacy in bypass preservation has not been well-studied. Recent studies have shown that DOACs may improve outcomes following bypasses; however, it is unclear if this is dependent upon type of bypass conduit. The goal of this study was to evaluate whether a difference exists between vein and prosthetic infra-geniculate bypasses outcomes based on the anticoagulant utilized on discharge, warfarin or DOAC. MethodsThe Vascular Quality Initiative infra-inguinal bypass database was queried for all patients who underwent an infra-geniculate bypass and were anticoagulation-naive at baseline but were discharged on either warfarin or DOACs. A survival analysis was performed for patients up to 1 year to determine whether the choice of discharge anticoagulation was associated with differences between those with vein vs prosthetic conduits in overall survival, primary patency, risk of amputation, or risk of major adverse limb events (MALE). A multivariable Cox proportional hazards analysis was performed to control for differences in baseline demographic factors between the groups. ResultsDuring the study period (2003-2020), 57,887 patients underwent infra-geniculate bypass. Of these, 3230 (5.5%) were anticoagulated on discharge. There was a similar distribution of anticoagulation between vein (n = 1659; 51.4%) and prosthetic conduits (n = 1571; 48.6%). Thirty-two percent were discharged on DOACs, and 68.0% were discharged on warfarin. For prosthetic conduits, being discharged on a DOAC was associated with improved outcomes on univariate and multivariable analyses revealing lower risk of overall mortality (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.41-0.93; P = .021), loss of primary patency (HR, 0.70; 95% CI, 0.55-0.89; P = .003), risk of amputation (HR, 0.71; 95% CI, 0.54-0.93; P = .013), and risk of MALE (HR, 0.80; 95% CI, 0.64-1.00; P = .048). Patients with a vein bypass had improved univariate outcomes for survival and primary patency; however, with multivariable analysis, there were no significant differences in outcomes between DOAC and warfarin. ConclusionsAnticoagulation-naive patients who underwent an infra-geniculate prosthetic bypass had higher rates of overall survival, bypass patency, amputation-free survival, and freedom from MALE when discharged on a DOAC compared with warfarin. Those with vein bypasses had similar outcomes regardless of the choice of anticoagulation.

Outcomes of lower extremity revascularization in octogenarians and nonagenarians for intermittent claudication

ObjectiveRevascularization for intermittent claudication (IC) due to infrainguinal peripheral arterial disease (PAD) is dependent on durability and expected benefit. We aimed to assess outcomes for IC interventions in octogenarians and nonagenarians (age ≥80 years) and those younger than 80 years (age <80 years). MethodsThe Vascular Quality Initiative was queried (2010-2020) for peripheral vascular interventions (PVIs) and infrainguinal bypasses (IIBs) performed to treat IC. Baseline characteristics, procedural details, and outcomes were analyzed (comparing age ≥80 years and age <80 years). ResultsThere were 84,210 PVIs (12.1% age ≥80 years and 87.9% age <80 years) and 10,980 IIBs (7.4% age ≥80 years and 92.6% age <80 years) for IC. For PVI, patients aged ≥80 years more often underwent femoropopliteal (70.7% vs 58.1%) and infrapopliteal (19% vs 9.3%) interventions, and less often iliac interventions (32.1% vs 48%) (P < .001 for all). Patients aged ≥80 years had more perioperative hematomas (3.5% vs 2.4%) and 30-day mortality (0.9% vs 0.4%) (P < .001). At 1-year post-intervention, the age ≥80 years cohort had fewer independently ambulatory patients (80% vs 91.5%; P < .001). Kaplan-Meier analysis showed patients aged ≥80 years had lower reintervention/amputation-free survival (81.4% vs 86.8%), amputation-free survival (87.1% vs 94.1%), and survival (92.3% vs 96.8%) (P < .001) at 1-year after PVI. Risk adjusted analysis showed that age ≥80 years was associated with higher reintervention/amputation/death (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.1-1.35), amputation/death (HR, 1.85; 95% CI, 1.61-2.13), and mortality (HR, 1.92; 95% CI, 1.66-2.23) (P < .001 for all) for PVI. For IIB, patients aged ≥80 years more often had an infrapopliteal target (28.4% vs 19.4%) and had higher 30-day mortality (1.3% vs 0.5%), renal failure (4.1% vs 2.2%), and cardiac complications (5.4% vs 3.1%) (P < .001). At 1 year, the age ≥80 years group had fewer independently ambulatory patients (81.7% vs 88.8%; P = .02). Kaplan-Meier analysis showed that the age ≥80 years cohort had lower reintervention/amputation-free survival (75.7% vs 81.5%), amputation-free survival (86.9% vs 93.9%), and survival (90.4% vs 96.5%) (P < .001 for all). Risk-adjusted analysis showed age ≥80 years was associated with higher amputation/death (HR, 1.68; 95% CI, 1.1-2.54; P = .015) and mortality (HR, 1.85; 95% CI, 1.16-2.93; P = .009), but not reintervention/amputation/death (HR, 1.1; 95% CI, 0.85-1.44; P = .47) after IIB. ConclusionsOctogenarians and nonagenarians have greater perioperative morbidity and long-term ambulatory impairment, limb loss, and mortality after PVI and IIB for claudication. Risks of intervention on elderly patients with claudication should be carefully weighed against the perceived benefits of revascularization. Medical and exercise therapy efforts should be maximized in this population.

Postoperative Outcomes and One-Year Mortality of Patients on Chronic Anticoagulation Medications Undergoing Infrainguinal Bypass

Patients requiring open infrainguinal bypass (IIB) frequently are taking chronic anticoagulation (AC) medications. Taking these medications in the preoperative setting may affect the outcomes of surgery. This study aims to evaluate postoperative outcomes and 1-year mortality of patients taking chronic AC medications that undergo IIB. Using data obtained from the Vascular Quality Initiative from January 2011 to October 2021, patients on warfarin or any direct oral anticoagulants (DOAC) within 30days of IIB were compared with patients not taking chronic AC medications. The primary outcomes were in-hospital, 30-day, and 1-year mortality. The secondary outcomes included total procedure time, need for perioperative packed red blood cell transfusion, prolonged length of hospital stay, postoperative myocardial infarction or stroke, and graft patency at discharge. A subgroup analysis was performed comparing patients taking warfarin with those taking DOACs. Univariate analyses and multivariate logistic regression, Kaplan Meier survival, and Cox regression analyses were used to analyze the data for postoperative and 1-year outcomes, respectively. A total of 55,076 patients underwent IIB during the study period, and 11,547 (20.97%) were on chronic AC prior to surgery. The 2 cohorts differed significantly in almost every demographic and clinical characteristic. Multivariate analyses adjusting for 45 potential confounders revealed that there was no significant difference in in-hospital, 30-day, and 1-year mortality. The total procedure time for the chronic AC cohort was on average 11.46±2.16min longer (P ≤ 0.001) and there was a greater risk of prolonged length of stay in the hospital (adjusted odds ratio [aOR]: 1.19, 95% confidence interval [CI]: 1.13-1.26, P<0.001). These patients also returned to the operating room (OR) at a greater rate (aOR: 1.12, 95% CI: 1.05-1.19; P=0.016) and demonstrated a significantly lower rate of graft patency at discharge (aOR: 0.73, 95% CI: 0.62-0.86, P=0.001). On subgroup analysis, multivariate analysis demonstrated lower 30-day mortality for the DOAC group in comparison to the warfarin group (aOR: 0.74, 95% CI: 0.57-0.94, P=0.015), but no significant differences in in-hospital and 1-year mortality. Patients taking AC medications within 30days prior to IIBs may require more perioperative red blood cell transfusions, longer hospitalizations, and return to the OR at a greater rate. They are also at an increased risk for loss of graft patency at discharge. However, these patients are not at increased risk of in-hospital, 30-day, or 1-year mortality. IIB can, therefore, be performed safely in patients taking chronic AC medications.