Major Reintervention Research Articles

TRANSITIONS OF FRAILTY AFTER LOWER EXTREMITY INTERVENTIONS FOR CHRONIC LIMB-THREATENING ISCHEMIA

Frailty is common among surgical patients and predicts poor surgical outcomes. This study aimed to analyze transitions in frailty state among patients undergoing lower extremity care for chronic limb-threatening ischemia (CLTI). Between 2018 and 2022, all patients undergoing a primary intervention for CLTI) (endovascular intervention-EV, bypass BYP, major amputation-AMP) or Wound Care (WOUND) were analyzed. Frailty was assessed by VQI-derived Risk Analysis Index (VQI-RAI). Frailty was defined as a VQI-RAI score > 35. Transition in frailty state between preoperative and follow-up measurement at one month and one year were analyzed. Patient characteristics leading to a transition in frailty state were analyzed using multivariable Cox regression analysis. Amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; Above ankle amputation of the index limb or major re-intervention (new bypass graft, jump/interposition graft revision) were evaluated. 1859 patients (56% male, age 65±11years, mean ± SD) underwent either EV (52%), a BYP (29%), AMP (13%), or WOUND (6%). 25% were considered frail on initial evaluation (28%, 16%, 32%, and 30% EV, BYP, AMP, and WOUND, respectively). At 30 days, overall frailty increased to 34%: 13% of patients moved from Non-Frail to Frail (9%, 18%, 22%, and 5% for EV, BYP, AMP, and WOUND, respectively), and 4% of patients moved from Frail to Non-Frail (6%, 2%, 1%, and 0% for EV, BYP, AMP, and WOUND, respectively). At one year, overall frailty increased to 40%: an additional 13% of patients shifted from Non-Frail to Frail (15%, 6%, 23%, and 8% for EV, BYP, AMP, and WOUND, respectively), and 5% of patients shifted from Frail to Non-Frail (4%, 8%, 2% and 0% for EV, BYP, AMP, and WOUND, respectively). At one year, frailty increased by 28% in EV, 16% for BYP, 32% in AMP, and 43% in WOUND. Frailty at baseline, 30 days, and one year was associated with a high Charlson's Comorbidity Index. Shifting to a frail state postoperatively was associated with decreased survival and a lower amputation-free survival at one year. Following major interventions for CLTI at one year, 27% of patients shift from a Non-Frail to a Frail state, and 9% of patients shift from a Frail to a Non-Frail state with differences across modalities in comparison to WOUND, where 13% of patients moved from a Non-Frail to a Frail state, and none shifted from a Frail to a Non-Frail state Shifting to a frail state after intervention is associated with poor outcomes and should be considered when evaluating and intervention in a patient with CLTI.

Thirty-Day Outcomes from the Disrupt PAD BTK II Study of the Shockwave Intravascular Lithotripsy System for Treatment of Calcified Below-the-Knee Peripheral Arterial Disease

Below-the-knee (BTK) lesions may be particularly challenging to treat owing to length, diffuse disease, and extent of calcification. Landmark interventional clinical studies have not reached consensus on the optimal standard of care for BTK lesions, and many published trials excluded patients with moderate or severe lesion calcification. Calcium modification with intravascular lithotripsy (IVL) was shown to be superior to percutaneous transluminal angioplasty in the femoropopliteal artery and successful in treating BTK lesions in pilot studies. The Disrupt BTK II study is a core laboratory-adjudicated, prospective, multicenter, single-arm study of patients with moderate to severely calcified BTK lesions treated with the Shockwave Medical Peripheral IVL System. Disrupt BTK II enrolled 250 subjects with calcified infrapopliteal lesions and Rutherford category 3-5 presentation from 38 sites in the United States and Europe. The primary safety endpoint was major adverse limb events or postoperative death at 30days, a composite of all-cause death, above-ankle amputation of the index limb, and/or major reintervention of the index limb involving an infrapopliteal artery. The primary effectiveness endpoint was procedural success, defined as ≤50% residual stenosis for all treated target lesions without serious core laboratory-adjudicated serious angiographic complications. The study used independent angiographic and duplex ultrasound core laboratories, and follow-up is planned through 2 years. A total of 305 lesions in 250 patients were treated with a procedural success of 97.9%. The mean target lesion length was 76± 65mm, diameter stenosis was 78%± 18%, and 84.8% had moderate or severe calcification as assessed by an independent angiographic core laboratory. After IVL, residual stenosis was reduced to 29%, and after optional postdilatation and/or stent implantation, to 26%. At 30days, there were no deaths, major adverse limb event rate was 0.8%, and mean improvement in Vascular Quality of Life scores was 4.0± 5.0 (P< .0001). Of the patients with baseline wounds, 15.8% healed and 53.4% were improved at 30days. The Disrupt PAD BTK II study demonstrated that treatment with the Shockwave Medical Peripheral IVL System in patients with moderate-severe calcified lesions resulted in high procedural success, significant reduction in residual stenosis, improvements in patient quality of life, and wound healing, with minimal adverse events at 30-day follow-up.

Female patients have fewer limb amputations compared to male patients in the BEST-CLI trial

ObjectiveFemale patients are less likely to be diagnosed with and treated for peripheral artery disease. When treated, there are also reported sex disparities in short- and long-term outcomes. We designed this study to compare outcomes after open and endovascular revascularization in the Best Endovascular vs best Surgical Therapy in patients with Critical Limb Ischemia (BEST-CLI) trial between females and males, and to examine outcomes of each revascularization type in an all-female cohort. MethodsIn a secondary analysis of cohorts 1 and 2 of the BEST-CLI Trial, patients with chronic limb-threatening ischemia (CLTI) undergoing open surgical bypass (with or without adequate conduit) and endovascular therapy were stratified by sex. In addition, in a female-only cohort, we evaluated differences in outcomes between treatment arm (combined all bypasses from cohorts 1 and 2 and compared with all endovascular treatment in cohorts 1 and 2). Outcomes included major amputation, reintervention, major adverse limb event (MALE, a composite of major amputation and reintervention), all-cause death, and composite outcome of MALE or all-cause death. Univariable and adjusted Cox regressions were used to assess outcome between males and females. Similar methods were used to assess differences in outcomes between treatment arm in females. ResultsAmong 1830 patients, females were significantly underrepresented, comprising only 28% (n = 519) of the BEST-CLI cohort. Overall, the characteristics of females enrolled in the trial had some differences compared with males: females were more likely to have rest pain alone (72% vs 60%; P < .0001) and when presenting with an ischemic wound, were less likely to have a wound infection (38% vs 47%; P = .01). Females were less likely to have an adequate single-segment greater saphenous vein (SSGSV) available (82% vs 89%; P = .01). Controlled for baseline clinical factors, at 1 year, females had significantly lower rates of major limb amputation compared with males (hazard ratio [HR], 0.70; P = .023), which drove better amputation- and MALE-free survival rates. All-cause death at 1 year was not statistically different between sexes (11.8% vs 11.2%; P = .286). In the all-female cohort, results paralleled the overall trial; open surgical bypass (with any conduit) had significantly better outcomes compared with endovascular therapy. Specifically, among females undergoing endovascular therapy, the rate of major reintervention was particularly high compared with females undergoing open surgical bypass (24.8% vs 10.5%; P < .001). ConclusionsDespite being underrepresented in BEST-CLI, the primary results of the trial, namely, improved MALE-free survival with open surgical bypass with SSGSV, were mirrored in the all-female subset. Female patients enrolled in BEST-CLI had better amputation-free survival at 1 year compared with male patients. These findings suggest that in treating female patients with CLTI considered appropriate for both open and endovascular revascularization, surgical bypass with optimal conduit is the preferred treatment option and can potentially ameliorate poor limb preservation outcomes associated with sex.

Prosthetic conduits have worse outcomes compared with great saphenous vein conduits in femoropopliteal and infrapopliteal bypass in patients with chronic limb-threatening ischemia

ObjectiveSingle segment great saphenous vein (SSGSV) traditionally has been considered the gold standard conduit for infrainguinal bypass. There are data supporting similar outcomes with prosthetic femoral-popliteal bypass. Moreover, some investigators have advocated for prosthetic conduit for femoral tibial bypass when GSV is inadequate or unavailable. We sought to evaluate long-term outcomes of infrainguinal bypass based on conduit type for treating chronic limb-threatening ischemia (CLTI). MethodsData from the Best Endovascular vs Best Surgical Therapy of Patients with CLTI multicenter, prospective, randomized controlled trial, comparing infrainguinal bypass with endovascular therapy in patients with CLTI, were evaluated. In this as-treated analysis, we compared outcomes of infrainguinal bypass using prosthetic, alternative autogenous vein (AAV), and cryopreserved vein (Cryo) with SSGSV bypass. Kaplan-Meier and multivariable analyses were performed to examine the associations of conduit type with major adverse limb events (MALE), reinterventions, above-ankle amputations, and all-cause death rates. ResultsIn total, 784 bypasses were analyzed (120 prosthetic, 33 AAV, 21 Cryo, AND 610 SSGSV). For prosthetic and SSGSV, the distribution was 357 femoropopliteal (93 prosthetic and 264 GSV) and 373 infrapopliteal (27 prosthetic and 346 GSV). The mean age for the overall cohort was 67.1 years; 27.4% were female, 29.9% were non-White, and 11.5% were of Hispanic ethnicity. Patients undergoing prosthetic bypass were older (69.2 years vs 66.7 years); more likely to have chronic obstructive pulmonary disease (22.5% vs 14.0%), prior coronary artery bypass grafting (88.9% vs 66.5%), and prior stroke (23.3% vs 14%); but less often were of Hispanic ethnicity (5.8% vs 12.6%) and had diabetes (59.2% vs 71.3%) (P < .05 for all). For femoropopliteal bypass, use of prosthetic conduit was associated with increased major reinterventions at 3 years overall (19.0% vs 11.5%; P = .06) and on risk-adjusted analysis (hazard ratio [HR], 2.13; 95% confidence interval [CI], 1.09-4.2; P = .028). No significant differences in MALE or death, above-ankle amputation, or death were observed. Outcomes were similar for bypasses to above-knee popliteal targets and below-knee popliteal targets. For infrapopliteal bypass, the use of a prosthetic conduit was associated with increased major reintervention (25.3% vs 10.3%; P = .005), death (68.6% vs 34.8%; P < .001), and MALE or death (90.0% vs 48.1%; P < .001) at 3 years. After risk adjustment, infrapopliteal bypass with prosthetic conduit was associated with higher major reintervention (HR, 4.14; 95% CI, 1.36-12.6; P = .012), above-ankle amputation (HR, 4.64; 95% CI, 1.59-13.5; P = .005), death (HR, 2.96; 95% CI, 1.4-6.2; P = .004), and MALE or death (HR, 3.59; 95% CI, 1.64-7.86; P = .001) compared with bypass with SSGSV. Overall, AAV had similar outcomes at 3 years as SSGSV; however, Cryo had significantly higher above-ankle amputation (50.0% vs 12.8%) (HR, 4.2; 95% CI, 1.68-10.5; P = .002), major reintervention (41.9% vs 10.7%) (HR, 3.12; 95% CI, 1.18-8.22; P = .02), and MALE/death (88.8% vs 37.8%) (HR, 2.96; 95% CI, 1.43-6.14; P = .004). ConclusionsThe use of a prosthetic conduit in infrainguinal bypass is associated with inferior outcomes compared with bypass using SSGSV, particularly for bypass to infrapopliteal targets. Cryo grafts were infrequent and also demonstrated inferior outcomes. SSGSV remains the preferred conduit of choice for infrainguinal bypass.

Treatment of chronic limb-threatening ischemia (CLTI) based on BEST-CLI and BASIL-2

The rate of vascular recanalizations in CLTI is increasing worldwide. Safety and efficacy of surgical versus endovascular treatment in CLTI patients was investigated in 2 prospective randomized trials with contrasting results. The BEST-CLI trial randomized 1830 patients with CLTI, the Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL-2) trial included 345 patients with CLTI. Best-CLI evaluated outcome events as the primary endpoint, which includes major reinterventions in addition to major amputations and death. Only half of the CLTI patients received a crural intervention or surgery. There were no differences in major amputations or death. After a median follow-up (FU) of 2,7 years, the surgery group showed significantly better results compared to the endovascular group, due to fewer re-interventions. BASIL-2 used amputation-free survival as the primary outcome and only included patients with lower leg lesions. After a median FU of 40 months, endovascular therapy was found to be superior. The extremely high mortality rate was remarkable in both studies. The BEST-CLI study represents CLTI patients only to a limited degree, whereas the BASIL-2 study presents the treatment of CLTI patients with below-the-knee-lesions quite well. Both studies confirm that patients with CLTI should be treated in specialized centers that offer both crural surgery and endovascular therapy. Cardiovascular risk factor management must play a more important role in reducing the high mortality associated with CLTI.

The impact of revascularization strategy on clinical failure, hemodynamic failure, and chronic limb-threatening ischemia symptoms in the BEST-CLI Trial

ObjectiveSustained clinical and hemodynamic benefit after revascularization for chronic limb-threatening ischemia (CLTI) is needed to resolve symptoms and prevent limb loss. We sought to compare rates of clinical and hemodynamic failure as well as resolution of initial and prevention of recurrent CLTI after endovascular (ENDO) vs bypass (OPEN) revascularization in the Best-Endovascular-versus-best-Surgical-Therapy-in-patients-with-CLTI (BEST-CLI) trial. MethodsAs planned secondary analyses of the BEST-CLI trial, we examined the rates of (1) clinical failure (a composite of all-cause death, above-ankle amputation, major reintervention, and degradation of WIfI stage); (2) hemodynamic failure (a composite of above-ankle amputation, major and minor reintervention to maintain index limb patency, failure to an initial increase or a subsequent decrease in ankle brachial index of 0.15 or toe brachial index of 0.10, and radiographic evidence of treatment stenosis or occlusion); (3) time to resolution of presenting CLTI symptoms; and (4) incidence of recurrent CLTI. Time-to-event analyses were performed by intention-to-treat assignment in both trial cohorts (cohort 1: suitable single segment great saphenous vein [SSGSV], N = 1434; cohort 2: lacking suitable SSGSV, N = 396), and multivariate stratified Cox regression models were created. ResultsIn cohort 1, there was a significant difference in time to clinical failure (log-rank P < .001), hemodynamic failure (log-rank P < .001), and resolution of presenting symptoms (log-rank P = .009) in favor of OPEN. In cohort 2, there was a significantly lower rate of hemodynamic failure (log-rank P = .006) favoring OPEN, and no significant difference in time to clinical failure or resolution of presenting symptoms. Multivariate analysis revealed that assignment to OPEN was associated with a significantly lower risk of clinical and hemodynamic failure in both cohorts and a significantly higher likelihood of resolving initial and preventing recurrent CLTI symptoms in cohort 1, including after adjustment for key baseline patient covariates (end-stage renal disease [ESRD], prior revascularization, smoking, diabetes, age >80 years, WIfI stage, tissue loss, and infrapopliteal disease). Factors independently associated with clinical failure included age >80 years in cohort 1 and ESRD across both cohorts. ESRD was associated with hemodynamic failure in cohort 1. Factors associated with slower resolution of presenting symptoms included diabetes in cohort 1 and WIfI stage in cohort 2. ConclusionsDurable clinical and hemodynamic benefit after revascularization for CLTI is important to avoid persistent and recurrent CLTI, reinterventions, and limb loss. When compared with ENDO, initial treatment with OPEN surgical bypass, particularly with available saphenous vein, is associated with improved clinical and hemodynamic outcomes and enhanced resolution of CLTI symptoms.

Surgery or endovascular therapy for patients with chronic limb-threatening ischemia requiring infrapopliteal interventions

ObjectiveThe recent publication of randomized trials comparing open bypass surgery to endovascular therapy in patients with chronic limb-threatening ischemia, namely, Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) and Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2), has resulted in potentially contradictory findings. The trials differed significantly with respect to anatomical disease patterns and primary end points. We performed an analysis of patients in BEST-CLI with significant infrapopliteal disease undergoing open tibial bypass or endovascular tibial interventions to formulate a relevant comparator with the outcomes reported from BASIL-2. MethodsThe study population consisted of patients in BEST-CLI with adequate single segment saphenous vein conduit randomized to open bypass or endovascular intervention (cohort 1) who additionally had significant infrapopliteal disease and underwent tibial level intervention. The primary outcome was major adverse limb event (MALE) or all-cause death. MALE included any major limb amputation or major reintervention. Outcomes were evaluated using Cox proportional regression models. ResultsThe analyzed subgroup included a total of 665 patients with 326 in the open tibial bypass group and 339 in the tibial endovascular intervention group. The primary outcome of MALE or all-cause death at 3 years was significantly lower in the surgical group at 48.5% compared with 56.7% in the endovascular group (P = .0018). Mortality was similar between groups (35.5% open vs 35.8% endovascular; P = .94), whereas MALE events were lower in the surgical group (23.3% vs 35.0%; P<.0001). This difference included a lower rate of major reinterventions in the surgical group (10.9%) compared with the endovascular group (20.2%; P = .0006). Freedom from above ankle amputation or all-cause death was similar between treatment arms at 43.6% in the surgical group compared with 45.3% the endovascular group (P = .30); however, there were fewer above ankle amputations in the surgical group (13.5%) compared with the endovascular group (19.3%; P = .0205). Perioperative (30-day) death rates were similar between treatment groups (2.5% open vs 2.4% endovascular; P = .93), as was 30-day major adverse cardiovascular events (5.3% open vs 2.7% endovascular; P = .12). ConclusionsAmong patients with suitable single segment great saphenous vein who underwent infrapopliteal revascularization for chronic limb-threatening ischemia, open bypass surgery was associated with a lower incidence of MALE or death and fewer major amputation compared with endovascular intervention. Amputation-free survival was similar between the groups. Further investigations into differences in comorbidities, anatomical extent, and lesion complexity are needed to explain differences between the BEST-CLI and BASIL-2 reported outcomes.

Clinical factors associated with ultrashort length of stay in patients undergoing lower extremity bypass for peripheral arterial disease

BackgroundLength of stay (LOS) is a major driver of cost and resource utilization following lower extremity bypass (LEB). However, the variable comorbidity burden and mobility status of LEB patients makes implementing enhanced recovery after surgery pathways challenging. The aim of this study was to use a large national database to identify patient factors associated with ultrashort LOS among patients undergoing LEB for peripheral artery disease. MethodsAll patients undergoing LEB for peripheral artery disease in the National Surgical Quality Improvement Project database from 2011 to 2018 were included. Patients were divided into two groups based on the postoperative length of stay : ultrashort (≤2 days) and standard (>2 days). Thirty-day outcomes were compared using descriptive statistics, and multivariable logistic regression was used to identify patient factors associated with ultrashort LOS. ResultsOverall, 17,510 patients were identified who underwent LEB, of which 2678 patients (15.3%) had an ultrashort postoperative LOS (mean, 1.8 days) and 14,832 (84.7%) patients had a standard LOS (mean, 7.1 days). When compared to patients with a standard LOS, patients with an ultrashort LOS were more likely to be admitted from home (95.9% vs 88.0%; P < .001), undergo elective surgery (86.1% vs 59.1%; P < .001), and be active smokers (52.1% vs 40.4%; P < .001). Patients with an ultrashort LOS were also more likely to have claudication as the indication for LEB (53.1% vs 22.5%; P < .001), have a popliteal revascularization target rather than a tibial/pedal target (76.7% vs 55.3%; P < .001), and have a prosthetic conduit (40.0% vs 29.9%; P < .001). There was no significant difference in mortality between the two groups (1.4% vs 1.8%; P = .21); however, patients with an ultrashort LOS had a lower frequency of unplanned readmission (10.7% vs 18.8%; P < .001) and need for major reintervention (1.9% vs 5.6%; P < .001). On multivariable analysis, elective status (odds ratio , 2.66; 95% confidence interval [CI], 2.33-3.04), active smoking (OR, 1.18; 95% CI, 1.07-1.30), and lack of vein harvest (OR, 1.55; 95% CI, 1.41-1.70) were associated with ultrashort LOS. Presence of rest pain (OR, 0.57; 95% CI, 0.51-0.63), tissue loss (OR, 0.30; 95% CI, 0.27-0.34), and totally dependent functional status (OR, 0.54; 95% CI, 0.35-0.84) were associated negatively with an ultrashort LOS. When examining the subgroup of patients who underwent vein harvest, totally dependent (OR, 0.38; 95% CI, 0.19-0.75) and partially dependent (OR, 0.53; 95% CI, 0.32-0.88) functional status were persistently negatively associated with ultrashort LOS. ConclusionsUltrashort LOS (≤2 days) after LEB is uncommon but feasible in select patients. Preoperative functional status and mobility are important factors to consider when identifying LEB patients who may be candidates for early discharge.

Serious Failure Modes After EVAR Are Device Specific.

Type I and III endoleaks following endovascular aneurysm repair (EVAR) can lead to catastrophic events that require major re-interventions. We reviewed our experience with aortic endograft re-interventions for type I and III endoleaks and other serious failures among different devices. We retrospectively reviewed patients with a prior EVAR who underwent open conversion (OC) or major endovascular intervention (MEI) (re-lining, cuff/limb extension, parallel graft) for type I/III endoleaks at our institution from 2002 to 2019. Baseline characteristics, procedural details, re-interventions, and outcomes were collected. A total of 229 patients (194 men) underwent re-interventions for type I and III endoleaks after EVAR (90 OC, 139 MEI) for devices implanted between 1997 and 2019. Average age at re-intervention was 78±8.5 years. A total of 135 (59%) were implanted at our institution, whereas 93 (41%) were referred. Median time to re-intervention was 4 years with 25% to 75% interquartile range (IQR) of 2.2-6.6 years. There was no significant difference in baseline demographics or type of re-interventions (OC/MEI) between device types. 42/229 (18%) presented with ruptured aneurysms, 20/229 (9%) were symptomatic, whereas the rest presented with asymptomatic radiographic findings. Type 1A endoleak was present in 146/229 (63.8%-72 with proximal migration), type IB in 46/229 (20.1%), type IIIA in 37/229 (16.6%), type IIIB in 15/229 (6.5%), and persistent aneurysm sac growth with no radiographic evidence of an endoleak in 6/229 (2.6%). Devices included most commercial products: AFX, Excluder, AneuRx, Ancure, Endurant, and Zenith. A smaller number of investigational devices accounted for the rest. Type 1A endoleak was the most common indication for re-intervention among all devices except for AFX and ancure devices, proximal migration was a frequent presentation with AneuRx. AFX devices more frequently presented with a type III and ancure devices more frequently presented with a type IB endoleak. Serious failure modes after EVAR differ between endografts and occur throughout the follow-up period. This is important to guide targeted interrogation of surveillance studies and follow-up schedules, even for discontinued devices, as well as comparisons between various series and estimation of EVAR failure rates. Surveillance after EVAR is critical for long term success of the repair, understanding of the differential modes of failure of every graft available is important in the longitudinal evaluation of these endografts. Equally important is the understanding of the modes of failure of legacy endografts that are no longer on the market but still being followed, in order to be able to tailor a surveillance regiemn and the evntual repair if needed.

Predicting Outcomes Following Lower Extremity Endovascular Revascularization Using Machine Learning.

Lower extremity endovascular revascularization for peripheral artery disease carries nonnegligible perioperative risks; however, outcome prediction tools remain limited. Using machine learning, we developed automated algorithms that predict 30-day outcomes following lower extremity endovascular revascularization. The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity endovascular revascularization (angioplasty, stent, or atherectomy) for peripheral artery disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day postprocedural major adverse limb event (composite of major reintervention, untreated loss of patency, or major amputation) or death. Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 machine learning models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Overall, 21 886 patients were included, and 30-day major adverse limb event/death occurred in 1964 (9.0%) individuals. The best performing model for predicting 30-day major adverse limb event/death was extreme gradient boosting, achieving an area under the receiver operating characteristic curve of 0.93 (95% CI, 0.92-0.94). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.70-0.74). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.09. The top 3 predictive features in our algorithm were (1) chronic limb-threatening ischemia, (2) tibial intervention, and (3) congestive heart failure. Our machine learning models accurately predict 30-day outcomes following lower extremity endovascular revascularization using preoperative data with good discrimination and calibration. Prospective validation is warranted to assess for generalizability and external validity.

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia

Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI. A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0mm (1 point), lesion length>300mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated. 1,607 patients (55% male, average age 60years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60±5%, 46±5%, and 22±9% at 5years for low-, moderate-, and high-risk groups, respectively (mean±standard error of the mean; P=0.008). Overall AFS was 55±5%, 37±6%, and 18±7% at 5years for low-, moderate-, and high-risk groups, respectively (mean±standard error of the mean; P=0.003). Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Abstract 3023: Association Of Lipoprotein(a) With Adverse Events Following Revascularization For Chronic Limb Threatening Ischemia: A Subgroup Analysis Of The BEST-CLI Trial

Background: Elevated lipoprotein(a) (Lp[a]) levels are implicated in the development of peripheral artery disease (PAD) and in major adverse limb events (MALE) across a range of PAD severity. The association between Lp(a) level and adverse events in patients with chronic limb threatening ischemia (CLTI) remains uncertain. Research Questions: Does Lp(a) level associate with MALE and death in patients with CLTI undergoing revascularization? Goals/Aims: To assess the association of Lp(a) level with MALE and death in patients with CLTI undergoing revascularization. Methods: The BEST-CLI trial was a randomized trial assessing the optimal revascularization strategy in patients with CLTI. A subgroup of patients underwent lipid and Lp(a) assessment during the study period and were included. The primary outcome was the first death or MALE event (above-ankle amputation or major reintervention). Hazard ratios were calculated using Cox proportional hazards models, adjusting for age, sex, statin use, and glomerular filtration rate. Results: A total of 192 patients (median [IQR] age, 67.5 [62.1, 74.2] years; 139 men [72.4%]) were included in the cohort. Median Lp(a) level was 26.8 [10.8, 65.1] with normal Lp(a) levels (&lt;30 mg/dL) observed in 104 patients, high levels (30-111 [the 90 th percentile] mg/dL) in 68 patients, and very high levels (&gt;111 mg/dL) in 20 patients. The primary outcome occurred in 75 (39.1%) patients, including 42 (40.4%), 25 (36.8%), and 8 (40.0%) patients with normal, high, and very high Lp(a) levels. There was no association between Lp(a) and the primary outcome (HR 1.00, 95% CI 0.99-1.02, Figure 1). A significant association between Lp(a) and death (HR 1.03, 95% CI 1.01-1.05) was noted. Results did not vary by randomized revascularization procedure. Conclusion: In this cohort, Lp(a) predicts death but not limb events in patients with CLTI. Larger studies are needed to understand the role of Lp(a) in patients with CLTI undergoing revascularization.

Perioperative complications of minor and major reinterventions for peripheral arterial disease.

Patients with peripheral arterial disease (PAD) frequently require reinterventions after lower-extremity revascularization (LER) to maintain perfusion. Current Society for Vascular Surgery guidelines define reinterventions as major or minor based on the magnitude of the procedure. While prior studies have compared primary LER procedures of different magnitudes, similar studies for reinterventions have not been performed. The objective of this study is to compare perioperative outcomes associated with major and minor reinterventions. Patients undergoing LER for PAD at a tertiary care center from 2013 to 2017 were included. A retrospective review of electronic medical records was performed, and reinterventions were categorized as major or minor based on the procedure magnitude. Minor reinterventions included endovascular procedures and open revision with patch angioplasty, while major reinterventions were characterized by open surgical or endovascular LER with catheter-directed thrombolysis (CDT). Perioperative outcomes following LER were captured and compared for major and minor reinterventions. An additional subgroup analysis was performed comparing outcomes associated with major reinterventions stratified into open major surgical reinterventions and CDT. This study included 713 patients over a mean follow-up of 2.5years. A total of 291 patients underwent 696 ipsilateral reinterventions (range = 1-12 reinterventions). Most reinterventions were minor (72.1%, N = 502) and 27.9% (N = 194) were major. Patients receiving reinterventions had an average age of 67.2 ± 11.5 and most were white (73.5%) males (60.1%) initially treated for claudication (58.2%) and CLTI (41.8%). There was significantly higher post-operative bleeding (9.8% vs 3.4%, p = .001), arterial thrombosis (3.1% vs 1.0%, p = .047), and acute renal failure (6.2% vs 2.4%, p = .014) after major reinterventions than minor. Additionally, major reinterventions had significantly higher return to the OR (17.0% vs 11.3%, p = .046) and longer hospital stays (7.5 vs 4.3days, p = <.0001). Overall, major reinterventions were associated with significantly increased perioperative morbidity (37.6% vs 19.7%, p ≤ .001) with no difference in perioperative mortality. In the subgroup analysis, open reinterventions resulted in significantly longer hospital stays (8.6days vs 5.5days, p ≤ .001) and more wound infections than CDT (11.0% vs 0%, p = .017). However, there was no other significant difference in morbidity or mortality following treatment with open surgical reinterventions or CDT. In this study, major reinterventions after LER were associated with greater perioperative morbidity than minor reinterventions, with no difference in mortality. Major reinterventions performed via open surgery and CDT had similar morbidity and mortality.

Relevance of BEST-CLI trial endpoints in a tertiary care limb preservation program

ObjectiveMajor adverse limb event-free survival (MALE-FS) differed significantly by initial revascularization approach in the BEST-CLI randomized trial. The BEST-CLI trial represented a highly selected subgroup of patients seen in clinical practice; thus, we examined the endpoint of MALE-FS in an all-comers tertiary care practice setting. MethodsThis is a single-center retrospective study of consecutive, unique patients who underwent technically successful infrainguinal revascularization for chronic limb-threatening ischemia (2011-2021). MALE was major amputation (transtibial or above) or major reintervention (new bypass, open bypass revision, thrombectomy, or thrombolysis). ResultsAmong 469 subjects, the mean age was 70 years, and 34% were female. Characteristics included diabetes (68%), end-stage renal disease (ESRD) (16%), Wound, Ischemia, and foot Infection (WIfI) stage 4 (44%), Global Limb Anatomic Staging System (GLASS) stage 3 (62%), and high pedal artery calcium score (pMAC) (22%). Index revascularization was autogenous vein bypass (AVB) (30%), non-autogenous bypass (NAB) (13%), or endovascular (ENDO) (57%). The composite endpoint of MALE or death occurred in 237 patients (51%) at a median time of 189 days from index revascularization. In an adjusted Cox model, factors independently associated with MALE or death included younger age, ESRD, WIfI stage 4, higher GLASS stage, and moderate-severe pMAC, whereas AVB was associated with improved MALE-FS. Freedom from MALE-FS, MALE, and major amputation at 30 days were 90%, 92%, and 95%; and at 1 year were 63%, 70%, and 83%, respectively. MALE occurred in 144 patients (31%) and was associated with ESRD, WIfI stage, GLASS stage, pMAC score, and index revascularization approach. AVB had superior durability, with adjusted 2-year freedom from MALE of 72%, compared with 66% for ENDO and 51% for NAB. Within the AVB group, spliced vein conduit had higher MALE compared with single-segment vein (hazard ratio, 1.8; 95% confidence interval, 0.9-3.7; P = .008 after inverse propensity weighting), but there was no statistically significant difference in major amputation. Of the 144 patients with any MALE, the first MALE was major reintervention in 47% and major amputation in 53%. Major amputation as first MALE was associated with non-AVB index approach. Indications for major reintervention were symptomatic stenosis/occlusion (54%), lack of clinical improvement (28%), asymptomatic graft stenosis (16%), and iatrogenic events (3%). Conversion to bypass occurred after 6% of ENDO cases, two-thirds of which involved distal bypass targets at the ankle or foot. ConclusionsIn this consecutive, all-comers cohort, disease complexity was associated with procedural selection and MALE-FS. AVB independently provided the greatest MALE-FS and freedom from MALE and major amputation. Compared with the BEST-CLI randomized trial, MALE after ENDO in this series was more frequently major amputation, with relatively few conversions to open bypass.

Secondary interventions following open vs endovascular revascularization for chronic limb threatening ischemia in the BEST-CLI trial

ObjectivesPatients undergoing revascularization for chronic limb-threatening ischemia experience a high burden of target limb reinterventions. We analyzed data from the Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) randomized trial comparing initial open bypass (OPEN) and endovascular (ENDO) treatment strategies, with a focus on reintervention-related study endpoints. MethodsIn a planned secondary analysis, we examined the rates of major reintervention, any reintervention, and the composite of any reintervention, amputation, or death by intention-to-treat assignment in both trial cohorts (cohort 1 with suitable single-segment great saphenous vein [SSGSV], n = 1434; cohort 2 lacking suitable SSGSV, n = 396). We also compared the cumulative number of major and all index limb reinterventions over time. Comparisons between treatment arms within each cohort were made using univariable and multivariable Cox regression models. ResultsIn cohort 1, assignment to OPEN was associated with a significantly reduced hazard of a major limb reintervention (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.28-0.49; P < .001), any reintervention (HR, 0.63; 95% CI, 0.53-0.75; P < .001), or any reintervention, amputation, or death (HR, 0.68; 95% CI, 0.60-0.78; P < .001). Findings were similar in cohort 2 for major reintervention (HR, 0.53; 95% CI, 0.33-0.84; P = .007) or any reintervention (HR, 0.71; 95% CI, 0.52-0.98; P = .04). In both cohorts, early (30-day) limb reinterventions were notably higher for patients assigned to ENDO as compared with OPEN (14.7% vs 4.5% of cohort 1 subjects; 16.6% vs 5.6% of cohort 2 subjects). The mean number of major (mean events per subject ratio [MR], 0.45; 95% CI, 0.34-0.58; P < .001) or any target limb reinterventions (MR, 0.67; 95% CI, 0.57-0.80; P < .001) per year was significantly less in the OPEN arm of cohort 1. The mean number of reinterventions per limb salvaged per year was lower in the OPEN arm of cohort 1 (MR, 0.45; 95% CI, 0.35-0.57; P < .001 and MR, 0.66; 95% CI, 0.55-0.79; P < .001 for major and all, respectively). The majority of index limb reinterventions occurred during the first year following randomization, but events continued to accumulate over the duration of follow-up in the trial. ConclusionsReintervention is common following revascularization for chronic limb-threatening ischemia. Among patients deemed suitable for either approach, initial treatment with open bypass, particularly in patients with available SSGSV conduit, is associated with a significantly lower number of major and minor target limb reinterventions.

Predicting outcomes following lower extremity open revascularization using machine learning

Lower extremity open revascularization is a treatment option for peripheral artery disease that carries significant peri-operative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following lower extremity open revascularization. The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity open revascularization for chronic atherosclerotic disease between 2011 and 2021. Input features included 37 pre-operative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using tenfold cross-validation, we trained 6 ML models. Overall, 24,309 patients were included. The primary outcome of 30-day MALE or death occurred in 2349 (9.3%) patients. Our best performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.93 (0.92–0.94). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.08. Our ML algorithm has potential for important utility in guiding risk mitigation strategies for patients being considered for lower extremity open revascularization to improve outcomes.

Long-term outcomes for hybrid aortic arch repair

ObjectiveSince its inception in the early 2000s, hybrid arch repair (HAR) has evolved from novel approach to well-established treatment modality for aortic arch pathology in appropriately selected patients. Despite this nearly 20-year history of use, long-term results of HAR remain to be determined. As such, objectives of this study are to detail the long-term outcomes for HAR within an expanded classification scheme. MethodsFrom August 2005 to August 2022, 163 consecutive patients underwent HAR at a single referral institution. Operative approach was selected according to an institutional algorithm and included zone 0/1 HAR in 25% (n = 40), type I HAR in 34% (n = 56), and type II/III HAR in 41% (n = 67). Specific zone 0/1 technique was zone 1 HAR in 31 (78%), zone 0 with innominate snorkel (zone 0S HAR) in 7 (18%), and zone 0 with single side-branch endograft (zone 0B HAR) in 2 (5%). The 30-day and long-term outcomes, including overall and aortic-specific survival, as well as freedom from reintervention, were assessed. ResultsThe mean age was 63 ± 13 years and almost one-half of patients (47% [n = 77]) had prior sternotomy. Presenting pathology included degenerative aneurysm in 44% (n = 71), residual dissection after prior type A repair in 38% (n = 62), chronic type B dissection in 12% (n = 20), and other indications in 6% (n = 10). Operative outcomes included 9% mortality (n = 14) at 30 days, 5% mortality (n = 8) in hospital, 4% stroke (n = 7), 2% new dialysis (n = 3), and 2% permanent paraparesis/plegia (n = 3). The median follow-up was 44 month (interquartile range, 12-84 months). Overall survival was 59% and 47% at 5 and 10 years, respectively, whereas aorta-specific survival was 86% and 84% at the same time points. At 5 and 10 years, freedom from major reintervention was 92% and 91%, respectively. Institutional experience had a significant impact on both early and late outcomes: comparing the first (2005-2012) and second (2013-2022) halves of the series, 30-day mortality decreased from 14% to 1% (P = .01) and stroke from 6% to 3% (P = .62). Improved operative outcomes were accompanied by improved late survival, with 78% of patients in the later era vs 45% in the earlier era surviving to 5 years. ConclusionsHAR is associated with excellent operative outcomes, as well as sustained protection from adverse aortic events as evidenced by high long-term aorta-specific survival and freedom from reintervention. However, surgeon and institutional experience appear to play a major role in achieving these superior outcomes, with a five-fold decrease in operative mortality and a two-fold decrease in stroke rate in the latter half of the series. These long-term results expand on prior midterm data and continue to support use of HAR for properly selected patients with arch disease.

Abstract 18362: Endovascular versus Surgical Revascularization for Chronic Limb Threatening Ischemia: A Comparison of Re-Admission Rates From NSQIP Database (2011-2021)

Background: Data regarding relative readmission rates following endovascular and surgical revascularization for chronic limb threatening ischemia (CLTI) are conflicting. Understanding comparative readmission rates may inform selection of the most appropriate revascularization modality for these patients. Research Question: What are the differences in 30-day readmission rates between endovascular and surgical interventions for CLTI? Methods: The 2012 to 2021 American College of Surgeons National Surgical Quality Improvement Program's (NSQIP) Targeted Vascular Module was used to identify patients discharged alive after surgical or endovascular revascularization for CLTI. The primary outcome was 30-day readmission following the index procedure; secondary outcomes included survival, major re-intervention of the treated arterial segment, amputation, untreated loss of patency of bypass graft, bleeding requiring transfusion or re-intervention, major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Revascularization modality was related to 30-day readmission using multivariable logistic regression. Results: We identified 30,390 patients (mean age 69±11.5 years, male 62.8%, mean BMI 26.9±8.1 kg/m 2 , 61% Caucasian, 20.2% Black). When compared with endovascular therapy, surgical bypass was associated with higher 30-day readmission (13.3% vs. 8.6%, p = &lt;0.001). After adjusting for demographic, clinical, procedural variables and year of publication, surgical revascularization was independently associated with higher 30-day readmission rates (OR 1.53 95% CI [1.36, 1.71]; p&lt;0.001), mortality and major reintervention rates (Figure). Conclusion: Surgical revascularization was independently associated with higher 30-day readmission rates when compared to endovascular revascularization for patients with CLTI.

Diabetes, Hypertension, and Smoking Do Not Affect Outcomes of Iliofemoral Vein Stenting for Chronic Proximal Venous Outflow Obstruction

ObjectiveDiabetes, hypertension, and smoking are well-recognized risk factors for Peripheral Artery Disease (PAD), but little is known of their impact on chronic venous insufficiency (CVI). This study evaluates these factors in patients undergoing iliac vein stenting (IVS) for CVI. MethodsA registry of 708 patients who underwent IVS from August 2011 to June 2021 was retrospectively analyzed. Symptoms were quantified using venous clinical severity score (VCSS) and CEAP classification. Both major and minor reinterventions were recorded. Logistic regression models were used to determine the unadjusted and adjusted odds ratio (OR) of any reintervention. Log-rank test was used to assess differences in reintervention-free survival. ResultsThe prevalence of hypertension was 51.1% (N = 362), diabetes was 23.0% (N = 163), and smoking was 22.2% (N = 157). Patients with diabetes (3.6 vs 3.4; P = 0.062), hypertension (3.6 vs. 3.3; P < 0.001), and smoking (3.7 vs 3.4; P = 0.003) had higher CEAP scores than those without these comorbidities. Improvement in VCSS composite scores showed no differences postoperatively (Diabetes: P = 0.513; Hypertension: P = 0.053; Smoking: P = 0.608), at 1-year follow-up (Diabetes: P = 0.666; Hypertension: P = 0.681; Smoking: P = 0.745), or at 5-year follow-up (Diabetes: P = 0.525; Hypertension: P = 0.953; Smoking: P = 0.146). Diabetes (P = 0.454), smoking (P = 0.355), and hypertension (P = 0.727) were not associated with increased odds of major reintervention. Log-rank test similarly showed no differences in reintervention-free survival for major or minor reoperations between those with and without diabetes (P = 0.79), hypertension (P = 0.14), and smoking (P = 0.80). ConclusionsDiabetes, hypertension, and smoking were prevalent among CVI patients, but unlike in PAD patients, they had little to no impact on long-term outcomes or reinterventions after IVS.

Predicting outcomes following open revascularization for aortoiliac occlusive disease using machine learning

ObjectiveOpen surgical treatment options for aortoiliac occlusive disease carry significant perioperative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following open aortoiliac revascularization. MethodsThe National Surgical Quality Improvement Program (NSQIP) targeted vascular database was used to identify patients who underwent open aortoiliac revascularization for atherosclerotic disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. The 30-day secondary outcomes were individual components of the primary outcome, major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death), individual components of MACE, wound complication, bleeding, other morbidity, non-home discharge, and unplanned readmission. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Variable importance scores were calculated to determine the top 10 predictive features. Performance was assessed on subgroups based on age, sex, race, ethnicity, symptom status, procedure type, and urgency. ResultsOverall, 9649 patients were included. The primary outcome of 30-day MALE or death occurred in 1021 patients (10.6%). Our best performing prediction model for 30-day MALE or death was XGBoost, achieving an AUROC of 0.95 (95% confidence interval [CI], 0.94-0.96). In comparison, logistic regression had an AUROC of 0.79 (95% CI, 0.77-0.81). For 30-day secondary outcomes, XGBoost achieved AUROCs between 0.87 and 0.97 (untreated loss of patency [0.95], major reintervention [0.88], major amputation [0.96], death [0.97], MACE [0.95], myocardial infarction [0.88], stroke [0.93], wound complication [0.94], bleeding [0.87], other morbidity [0.96], non-home discharge [0.90], and unplanned readmission [0.91]). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. The strongest predictive feature in our algorithm was chronic limb-threatening ischemia. Model performance remained robust on all subgroup analyses of specific demographic/clinical populations. ConclusionsOur ML models accurately predict 30-day outcomes following open aortoiliac revascularization using preoperative data, performing better than logistic regression. They have potential for important utility in guiding risk-mitigation strategies for patients being considered for open aortoiliac revascularization to improve outcomes.