Prosthetic Conduit Research Articles

Late pseudo-aneurysms after coarctation repair with extra-anatomic ascending-descending aortic bypass surgery

Abstract Background Extra-anatomic ascending-descending aortic bypass operations are an alternative to difficult aortic arch reconstruction in patients with complex aortic coarctation. Reported short-term results are favorable, however, data on long-term outcomes are sparse. The aim of our study was to report long-term outcomes in affected adult patients. Methods We identified all adults with extra-anatomic ascending-descending aortic bypass surgeries followed at our center. Outcomes were assessed by chart review with a specific focus on formation of late pseudo-aneurysms and requirement for redo surgery. Results We identified a total of 12 adults (67% males) with previous ascending-descending aortic bypass surgery. These patients account for 12/171 (7%) of adults with aortic coarctation followed at our center. 10/12 patients (83%) had undergone coarctation repair by different repair techniques before ascending-descending aortic bypass surgeries. Median age at ascending-descending aortic bypass surgery was 17 years (range: 7-42 years). Prosthetic conduit sizes ranged from 12-22mm. In long-term follow-up, 11/12 patients (92%) required antihypertensive medication (median 2 antihypertensive drugs, 50% ≥ 3 drugs). A total of 5/12 patients (42%) required redo-surgery for formation of pseudo-aneurysms (figure 1) at graft anastomoses (4 proximal anastomosis at ascending aorta, 1 distal anastomosis to descending aorta) at a median age of 47.6 years (28.2-65.0 years) and a median of 22.1 years (range: 14.7-24.6 years) after the initial extra-anatomic ascending-descending aortic bypass operation (figure 2). Two of these patients required redo-operations / interventions for recurrent pseudo-aneurysms at 26 and 33 months after the redo-operations. Conclusions Although reported short- and medium-term outcomes after ascending-descending aortic bypass surgery for complex aortic coarctation are favorable, our data suggest a high rate of pseudo-aneurysm formation late (>10 years) after surgery. Our data highlight the need for careful long-term (life-long!) follow-up of these patients at specialized centers.

Spliced-Vein Conduit Offers Better Patency and Limb Salvage Than Prosthetic Graft for Femoral-Tibial Bypasses in Critical Limb-Threatening Ischemia

BackgroundSingle-segment great saphenous vein (ssGSV) is the gold standard conduit for femoral-tibial bypasses in patients with critical limb-threatening ischemia (CLTI). In the absence of a good single-segment saphenous vein, alternative options are prosthetic grafts or spliced-vein conduits. Although spliced-vein conduits may provide better long-term patency/limb salvage, prosthetic grafts are more often the chosen conduit due to shorter operative and presumably better immediate postoperative outcomes; nevertheless, there is little data supporting this practice. In this study, we compared 30-day outcomes between spliced-vein and prosthetic conduits in CLTI bypass using a national registry. MethodsCLTI patients who underwent lower extremity bypass using spliced vein (SpV) or prosthetic conduits only were selected from National Surgical Quality Improvement Program (NSQIP) targeted database. A 1:5 propensity-score matching was conducted between SpV and prosthetic groups to address preoperative differences. Thirty-day outcomes, including primary patency, reintervention, major amputation, mortality, major morbidity, transfusion, and wound complications, were compared between the two groups. ResultsThere were 886 patients who underwent femoral-tibial bypass without ssGSV (104 SpV and 782 prosthetic grafts). All SpV patients were propensity-score matched to 445 prosthetic patients. SpV exhibited significantly better 30-day primary patency than prosthetic (87.5% vs 74.38%, P = 0.004). SpV was associated with significantly longer operative time (346 min vs 222 min, P < .001) and higher transfusion (43.3% vs 27.87%, P =0.003), but those did not translate into higher 30-day mortality or major systemic complications. There was no difference in wound complications or 30-day limb loss. ConclusionSpliced-vein conduit affords significantly better 30-day primary patency than prosthetic grafts without increased mortality and morbidities. Therefore, despite greater procedural complexity and longer operative time, spliced-vein conduit should be considered when available. Future prospective studies are needed to investigate the long-term outcomes of these two conduits.

A Prosthetic Conduit can be Used Safely for TransCarotid Artery Revascularization Under Local Anesthesia in High-Risk Patients.

Surgical management of carotid stenosis has evolved from open carotid endarterectomy (CEA) to include multiple alternative procedures including transfemoral carotid artery stenting (tfCAS) and transcarotid artery stenting. In recent years, Transcarotid Artery Revascularization (TCAR) has emerged as a third option, combining open cut down to the common carotid artery (CCA) with endovascular stenting and neuroprotection via reversal of cerebral blood flow. In this case series, a modified TCAR procedure using a prosthetic conduit was successfully performed exclusively under local anesthesia in a total of 10 patients with carotid artery stenosis, high cardiac risk, and anatomical contraindications to a traditional TCAR.

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.

Prophylactic muscle flaps in high-risk-for-poor-healing patients with prosthetic bypasses increases deep wound complications.

Incisional complications of groin after inflow or infrainguinal bypasses with prosthetic conduits can result in major morbidities that require reoperation, infected graft removal, and limb loss. Muscle flaps are typically performed to treat groin wound complications, but they are also done prophylactically at the time of index procedures in certain high-risk-for-poor-healing patients to mitigate anticipated groin wound complications. We used a nationwide multi-institutional database to investigate outcomes of prophylactic muscle flaps in high-risk patients who underwent prosthetic bypasses involving femoral anastomosis. We utilized ACS-NSQIP database 2005-2021 to identify all elective inflow and infrainguinal bypasses that involve femoral anastomoses. Only high-risk patients for poor incisional healing who underwent prosthetic conduit bypasses were selected. A 1:3 propensity-matching was performed to obtain two comparable studied groups between those with (FLAP) and without prophylactic muscle flaps (NOFLAP) based on demographics and comorbidities. 30-day postoperative outcomes were compared. Among 35,011 NOFLAP, 990 of them were propensity-matched to 330 FLAP. There was no significant difference in 30-day mortality, MACE, pulmonary, or renal complications. FLAP was associated with higher bleeding requiring transfusion, longer operative time, and longer hospital stay. FLAP also had higher overall wound complications (15.2% vs. 10.6%; p=0.03), especially deep incisional infection (4.9% vs. 2.4%; p=0.04). Prophylactic muscle flap for prosthetic bypasses involving femoral anastomosis in high-risk-for-poor-healing patients does not appear to mitigate 30-day wound complications. Caution should be exercised with this practice and more long-term data should be obtained to determine whether prophylactic flaps decrease the incidence of graft infection.

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.

Risk score for one-year mortality following emergent infra-inguinal bypass

ObjectiveThe purpose of this study is to identify variables that place patients at higher risk for mortality following emergent infra-inguinal bypass. Further, this study will create a risk score for mortality following emergent infra-inguinal bypass to help tailor postoperative and long-term patient management. MethodsIn the Vascular Quality Initiative, we identified 2126 patients who underwent emergent infra-inguinal artery bypass. Two primary outcomes were investigated: 30 day mortality following emergent infra-inguinal bypass; and 1-year mortality following emergent infra-inguinal bypass. The first step in analysis was univariable analysis for each outcome with χ2 analysis for categorical variables and Student t-test for comparison of means of ordinal variables. Next, binary logistic regression analysis was performed for each outcome utilizing variables that achieved a univariable P value ≤ .10. Factors with a multivariable P value ≤ .05 were included in the risk score, and points were weighted and assigned based on the respective regression beta-coefficient in the multivariable regression. ResultsVariables with a significant multivariable association (P < .05) with 1-year mortality were: increasing age; body mass index less than 20 kg/m2; coronary artery disease; active hemodialysis at time of presentation; anemia at admission; prosthetic conduit for emergent bypass; postoperative myocardial infarction; postoperative acute renal insufficiency; perioperative stroke; baseline non-ambulatory status; new onset hemodialysis requirement perioperatively; need for bypass revision or thrombectomy during index admission; lack of statin prescription at discharge; lack of antiplatelet medication at discharge; and, lack of anticoagulation at time of hospital discharge. Pertinent negatives included all sociodemographic variables including rural living status, insurance status, and Area Deprivation Index home area. The risk score achieved an area under the curve of 0.820, and regression analysis of the risk score achieved an overall accuracy of 87.9% with 97.7% accuracy in predicting survival, indicating the model performs better in determining which patients will survive rather than precisely determining who will experience 1-year mortality. ConclusionsDischarge medications are the primary modifiable variable impacting survival after emergent infra-inguinal bypass surgery. In the absence of contraindication, all these patients should be discharged on antiplatelet, statin, and anticoagulant medications after emergent infra-inguinal bypass as they significantly enhance survival. Social determinants of health do not impact survival among patients treated with emergent infra-inguinal bypass at Vascular Quality Initiative centers. A risk score for mortality at 1 year after emergent infra-inguinal bypass has been created that has excellent accuracy.

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.

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.

Current outcomes following upper and lower extremity arterial trauma from the National Trauma Data Bank

ObjectiveThe modern treatments of trauma have changed in recent years. We aim to evaluate the factors associated with limb salvage and mortality after extremity arterial trauma, especially with respect to the type of conduit used in revascularization. MethodsThe National Trauma Data Bank was queried to identify patients with upper and lower extremity (UE and LE) arterial injuries between 2016 and 2020. The patients were stratified by the types of arterial repair. The primary outcome was in-hospital mortality. Results8780 patients were found with 5054 (58%) UE and 3726 (42%) LE injuries. Eighty-three percent were men, and the mean age was 34 ± 15 years. Penetrating mechanism was the predominant mode of injury in both UEs and LEs (73% and 67%, respectively) with a mean injury severity score of 14 ± 8. For UEs, the majority underwent primary repair (67%, P < .001), whereas the remainder received either a bypass (20%) or interposition graft (12%). However, LEs were more likely to receive a bypass (52%, P < .00001) than primary repair or interposition graft (34% and 14%, respectively). Compared with the extremely low rates of amputation and mortality among UE patients (2% for both), LE injuries were more likely to result in both amputation (10%, P < .001) and death (6%, P < .001). Notably, compared with primary repair, the use of a prosthetic conduit was associated with a 6.7-fold increase in the risk of amputation in UE and a 2.4-fold increase in LE (P < .0001 for both). Synthetic bypasses were associated with a nearly 3-fold increase in return to the operating room (OR) in UE bypasses (P < .05) and a 2.4-fold increase in return to the OR in LE bypasses (P < .0001). ConclusionsIn recent years, most extremity vascular trauma was due to penetrating injury with a substantial burden of morbidity and mortality. However, both limb salvage rates and survival rates have remained high. Overall, LE injuries more often led to amputation and mortality than UE injuries. The most frequently used bypass conduit was vein, which was associated with less risk of unplanned return to the OR and limb loss, corroborating current practice guidelines for extremity arterial trauma.

Feasibility and Intermediate Results of Transcarotid Revascularization with a Prosthetic Conduit

IntroductionTranscarotid artery revascularization (TCAR) is a hybrid technique with excellent initial outcomes. The technical success and safety of TCAR is heavily dependent on an anatomically suitable common carotid artery (CCA). Many patients do not meet anatomic criteria and therefore are not eligible for this therapy. We sought to extend the eligibility of TCAR to patients with unfavorable CCA anatomy via the adoption of a prosthetic arterial conduit. MethodsA single center retrospective study of patients with critical carotid artery stenosis who underwent TCAR via a prosthetic conduit between June 2019 and October 2021 was performed. All patients in the study were considered high-risk for carotid endarterectomy (CEA) based on anatomic features, such as restenosis post-CEA and neck radiation. Unfavorable CCA anatomy was defined as a clavicle to carotid bifurcation distance < 5 cm, a CCA diameter < 6 mm, and/or significant atherosclerotic disease at the intended arterial access site. The primary outcome of interest was technical success. Secondary outcomes included perioperative complications, intermediate and long-term patency, intermediate and long-term stroke and/or mortality and in-hospital length of stay. Follow-up ranged from 1-29 months. ResultsEight patients underwent ten TCAR procedures via a prosthetic conduit. A total of two procedures (20%) were performed on female patients and eight procedures (75%) were performed on male patients. The mean age was 65 years old (standard deviation (SD) 11 years). Technical success was 100%. The 30-day ipsilateral stroke rate was 0%. The 30-day patency was 90%. There was no re-exploration for hemorrhage and 30 day mortality was 0%. ConclusionsTCAR is an excellent option for carotid artery revascularization. Unfavorable CCA anatomy has limited its applicability. TCAR via a prosthetic conduit has the potential to expand eligibility for this promising therapy.

Contemporary outcomes for arterial reconstruction with non-saphenous vein cryo-preserved conduits

ObjectiveCryopreserved (CP) products are utilized during challenging cases when autogenous or prosthetic conduit use is not feasible. Despite decades of experience with cadaveric greater saphenous vein (GSV), there is limited available data regarding the outcomes and patency of other CP products, specifically arterial and deep venous grafts. This study was designed to evaluate outcomes of non-GSV CP conduits in patients undergoing urgent, emergent, and elective arterial reconstruction at our institution. We hypothesized that non-GSV CP allografts have adequate patency and outcomes and are therefore a feasible alternative to GSV in settings where autologous graft is unavailable or prosthetic grafts are contraindicated. MethodsThis study was approved by the Institutional Review Board at our institution. We retrospectively reviewed charts of patients undergoing arterial reconstructions using CP conduits from 2010 to 2022. Data collected included demographics, comorbidities, smoking status, indications for surgery, indication for CP conduit use, anatomic reconstruction, urgency of procedure, and blood loss. Time-to-event outcomes included primary and secondary graft patency rates, follow-up amputations, and mortality; other complications included follow-up infection/reinfection and 30-day complications, including return to the operating room and perioperative mortality. Time-to-event analyses were evaluated using product-limit survival estimates. ResultsOf 96 identified patients receiving CP conduits, 56 patients received non-GSV conduits for 66 arterial reconstructions. The most common type of non-GSV CP product used was femoral artery (31 patients), followed by aorto-iliac artery (22 patients), and femoral vein (19 patients), with some patients receiving more than one reconstruction or CP product. Patients were mostly male (75%), with a mean age of 63.1 years and a mean body mass index of 26.7 kg/m2. Indications for CP conduit use included infection in 53 patients, hostile environment in 36 patients, contaminated field in 30 patients, tissue coverage concerns in 30 patients, inadequate conduit in nine patients, and patient preference in one patient. Notably, multiple patients had more than one indication. Most surgeries (95%) were performed in urgent or emergent settings. Supra-inguinal reconstructions were most common (53%), followed by extra-anatomic bypasses (47%). Thirty-day mortality occurred in 10 patients (19%). Fifteen patients (27%) required return to the operating room for indications related to the vascular reconstructions, with 10 (18%) cases being unplanned and five (9%) cases planned/staged. Overall survival at 6, 12, and 24 months was 80%, 68%, and 59%, respectively. Primary patency at 6, 12, and 24 months was 86%, 70%, and 62%, respectively. Amputation freedom at 6 months, 12 months, and 24 months was 98%, 95%, and 86%, respectively for non-traumatic indications. ConclusionsNon-GSV CP products may be used in complex arterial reconstructions when autogenous or prosthetic options are not feasible or available.

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.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAA), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear. A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency. From 1999-2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and two (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs 66 years, p=0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs 23.2%, p<0.001). Conduit type did not impact postoperative complication rates (p=NS each). MALE rates were low overall (19.2% at two years), and similar when stratified by conduit type (log rank p=0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, p<0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, p=0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, p=0.97) were not associated with MALE. Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

Prosthetic Conduit Does Not Adversely Impact Outcomes of Open Repair of Popliteal Artery Aneurysms

Prosthetic Conduit Does Not Adversely Impact Outcomes of Open Repair of Popliteal Artery Aneurysms

Post-operative transfusion is associated with infrainguinal bypass graft failure: contemporary Australian tertiary centre experience.

Peripheral arterial disease (PAD) is an increasingly prevalent and highly morbid pathology affecting the older population. Infra-inguinal bypass (IIB) surgery remains a robust revascularization option in these patients. This study aimed to identify modifiable predictors associated with graft patency and functional outcomes in contemporary Australian vascular surgical practice. A retrospective analysis of patients undergoing IIB between 2010 and 2020 at a tertiary vascular surgery centre in Australia was performed. Data regarding patient demographics, co-morbidities, pre-operative investigations, bypass characteristics, and discharge outcomes were collected. Surveillance ultrasound scans were reviewed to gain information on graft patency and compliance up to 2 years post-operatively. The primary outcome was graft failure. Secondary outcomes were mobility status and amputation-free survival at 1 year. A total of 239 IIBs were performed on 207 patients during the 10-year period. Significant predictors for primary graft occlusion included regional referral (P < 0.01), low pre-operative haemoglobin level (P < 0.01), post-operative transfusion requirement (P = 0.02), use of prosthetic conduit (P < 0.01) and non-compliance to ultrasound surveillance (P < 0.01). Patients with a thrombosed graft were 2.4 times more likely to experience deterioration in mobility status (P < 0.01) and 8.6 times more likely to have major limb amputation or death at 1 year. The amputation-free survival was 88.3% at 1 year. Optimization of pre-operative haemoglobin level for IIB should be advocated in clinical practice in order to reduce the risk of graft failure, deterioration in ambulatory function, major limb amputation and mortality.

Use of a prosthetic conduit for stent delivery in transcarotid artery revascularization for patients with unfavorable anatomy.

Transcarotid artery revascularization (TCAR) provides a safe alternative to carotid endarterectomy. The anatomic requirements include a 5-cmminimum clavicle to carotid bifurcation distance for sheath access proximal to the lesion. In the present report, we describe our experience with conduit use for patients not meeting that requirement. Patients undergoing elective TCAR with a conduit from 2021 to 2022 were retrospectively identified. After carotid artery exposure, a 6-mm prosthetic graft was anastomosed to the common carotid artery in an end-to-side fashion. After stent delivery, the conduit was ligated and oversewn. The patient demographics, procedural details, and outcomes were recorded and compared with our nonconduit TCAR experience. A total of 11 patients (64% male; age, 75± 5years) underwent TCAR with a conduit, 5 (46%) for symptomatic disease, and 77 patients underwent TCAR with no conduit, 52 (60%) with symptomatic disease (P= .50). Other than a higher rate of prior coronary interventions in the conduit group (55% vs 47%; P= .007), no significant differences were found in age, gender, race, comorbidities, or high risk for carotid endarterectomy criteria. In the conduit group, the average skin to carotid artery depth was 4.2cm (range, 1.9-6.1cm). The average clavicle to bifurcation distance was 4.4cm (range, 3.3-4.9cm) vs 6.5cm (range, 3.3-9.7cm; P= .002) in the nonconduit group. Dacron was the most common conduit material used (73%). No differences were found in the mean procedure times (121± 32 vs 129± 53minutes; P= .785) or flow reversal times (14± 5 vs 19± 13minutes; P=.989) for the conduit and nonconduit cohorts, respectively. Technical success was achieved in 100% of the conduit and nonconduit cases. Excluding one outlier of a prolonged stay (7days) for management of unrelated medical issues (gastrostomy tube placement for chronic dysphagia after mass resection and neck radiation), the mean hospital stay was 2days (1.2± 0.4 intensive care unit days) compared with 3.8± 5.7days for our nonconduit cohort (P= .2). Hypotension was the most common reason for delayed discharge for the conduit group (n=3; 27%). The average follow-up was 2.7months (range, 1-10months). For all 11 conduit patients, the stent remained patent without stenosis, thrombus, or pseudoaneurysm at the conduit stump site on surveillance duplex ultrasound. No strokes or complications had occurred at 30days in the conduit group compared with four strokes or transient ischemic attacks (P= .469) and 18 minor complications in the nonconduit group (P= .091). For patients lacking a sufficient distance between the clavicle and carotid artery bifurcation, a prosthetic conduit facilitates safe use of flow reversal for stent delivery and can be ligated at procedural completion without consequences.

Investigation of center-specific saphenous vein utilization rates in femoral popliteal artery bypass and associated impact of conduit on outcomes

ObjectiveThe purpose of this study is to investigate variation in great saphenous vein (GSV) use among the various centers participating in the Vascular Quality Initiative infrainguinal bypass modules. Further, differences in outcomes in femoral-popliteal artery bypass with single segment GSV conduit vs prosthetic conduit will be documented. Center GSV use rate impact on outcomes will be investigated. MethodsPrimary exclusions were patients undergoing redo bypass, urgent or emergent bypass, and those in whom prosthetic graft was used while having undergone prior coronary artery bypass grafting. The distribution of GSV use across the 260 centers participating in Vascular Quality Initiative infrainguinal bypass module was placed into histogram and variance in mean GSV use evaluated with analysis of variance analysis. Centers that used GSV in >50% of bypasses were categorized as high use centers and centers that used the GSV in <30% of cases were categorized as low use centers. Baseline differences in patient characteristics and comorbidities in those undergoing bypass with GSV vs prosthetic conduit were analyzed with χ2 testing and the Student t test, as were those undergoing treatment in high vs low use centers. Multivariable time-dependent Cox regression analyses were then performed for the primary outcomes of major amputation ipsilateral to the operative side and mortality in long-term follow-up. High vs low use center was a dichotomous variable in these regressions. Secondary outcomes of freedom from graft infection and freedom from loss of primary patency were performed with Kaplan-Meier analysis. ResultsAmong centers with >50 patients meeting inclusion criteria for this study, GSV use ranged from 15% to 93% (analysis of variance P < .001). When considering all centers irrespective of number of patients, the range was 0% to 100%. On Kaplan-Meier analysis, GSV conduit use was associated with improved freedom from loss of primary or primary assisted patency, improved freedom from major amputation after index hospitalization, improved freedom from graft infection after the index hospitalization, and improved freedom from mortality in long-term follow-up (log-rank P < .001 for all four outcomes). Both low use center (hazard ratio, 1.35; P < .001) and prosthetic graft use (hazard ratio, 1.24; P < .001) achieved multivariable significance as risks for mortality in long-term follow-up. Other variables with a multivariable mortality association are presented in the manuscript. Low use center and prosthetic bypass were significant univariable but not multivariable risks for major amputation after index hospitalization. ConclusionsThere is remarkably wide variation in GSV use for femoral popliteal artery bypass among various medical centers. GSV use is associated with enhanced long-term survival as well as freedom from loss of bypass patency and graft infection. The data herein indicate institutional patterns of prosthetic conduit choice, which has the potential to be altered to enhance outcomes.

Association between postoperative exposure to fine particulate matter and patency of the right ventricle–pulmonary artery conduit

BackgroundAmbient air pollution is a leading risk factor for cardiovascular diseases. No study has investigated the association between exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM2.5) and the prognosis of patients undergoing surgery for the right ventricle–pulmonary artery (RV-PA) conduit. MethodsFrom 2013 to 2020, patients with six complicated congenital heart defects who had undergone surgery for the RV–PA conduit were selected. Four conduit materials were used: bovine jugular vein graft (BJV), pulmonary homograft (PHG), aortic homograft (AHG), and handmade tri-leaflet expanded polytetrafluoroethylene (ePTFE) conduit. Telephone interviews were used to confirm the postoperative address of patients. The monthly average PM2.5 concentration was obtained from the ChinaHighPM2.5 dataset using the place of residence of patients. By comparing findings of echocardiography undertaken before patients' return to their residence and during re-examination, we defined an increase in the trans-conduit peak velocity of ≥1.5 m/s as the study endpoint. ResultsWe enrolled 232 patients. Compared with BJV conduits, homografts (AHGs and PHGs) (0.052 (95 % CI = 0.005–0.558), P = 0.015) and ePTFE conduits (0.009 (95 % CI = 0.002–0.054), P < 0.001) were protective factors. The cumulative monthly PM2.5 concentration (10 μg/m3) was a risk factor (1.014 (95 % CI = 1.001–1.026), P = 0.028). Winter experience was a risk factor (1.971 (95 % CI: 1.021–3.804), P = 0.043). In the subgroup analysis, Spearman correlation analysis indicated BJV conduits (r = 0.680, P < 0.001), PHGs (r = 0.559, P = 0.020), and AHGs (r = 0.745, P = 0.021) had medium-to-high positive correlations between the cumulative PM2.5 concentration and change in the conduit velocity. For ePTFE, the correlation was weak and not significant (r = 0.222, P = 0.073). ConclusionsPostoperative exposure to PM2.5 affects the patency of biologic prosthetic conduits (especially xenografts). The increase in the velocity of the ePTFE conduit is not associated with PM2.5 exposure, and is a suitable material for patients living in areas with high pollutant concentrations.

Association Between Conduit Type and Outcomes After Open Repair of Popliteal Artery Aneurysms

IntroductionPrior studies have demonstrated acceptable midterm outcomes with prosthetic conduits for above-knee bypass for occlusive disease in patients with inadequate segment great saphenous vein (GSV). In this study we aimed to investigate whether this holds true for open repair of popliteal artery aneurysms (PAA). MethodsWe queried the Vascular Quality Initiative data for patients who underwent open PAA repair (OPAR). We divided the cohort into three groups based on the conduit used: GSV, other autologous veins, or prosthetic graft. Study outcomes included primary patency, freedom from major amputation, amputation-free survival, and overall survival at 1 y. Kaplan–Meier survival estimates, log-rank tests and multivariable Cox regression were used to compare outcomes between study groups. ResultsA total of 4016 patients underwent bypass for PAA from January 2010 to October 2021. The three cohorts were significantly different in many demographic and clinical characteristics. The adjusted odds of postoperative amputation among symptomatic patients were 3-fold higher for prosthetic conduits compared to the GSV (odds ratio, 3.20; 95% CI, 1.72-5.92; P < 0.001). For the 1-y outcomes, the adjusted risk of major amputation was almost 3-fold higher for patients with symptomatic disease undergoing bypass with prosthetic conduits (hazard ratio [HR], 2.97; 95% CI, 1.35-6.52; P = 0.007). When compared with GSV, prosthetic conduits were associated with 96% increased risk of death when used for repair in symptomatic patients (adjusted hazard ratio (aHR), 1.96; 95% CI, 1.29-2.97; P = 0.002) but no significant association with mortality in asymptomatic patients (aHR, 0.83; 95% CI, 0.37-1.87; P = 0.652). When compared with GSV, prosthetic conduits were associated with a 2-fold increased risk of 1-y major amputation or death when used for repair in symptomatic patients (aHR, 2.03; 95% CI, 1.40-2.94; P < 0.001) but no significant association with mortality in asymptomatic patients (aHR, 0.91; 95% CI, 0.42-1.98; P = 0.816). Comparing bypass with other veins to the GSV among patients with symptomatic disease, there was no statistically significant difference in major amputation risk (HR; 2.44; 95% CI, 0.55-10.82; P = 0.242) and no difference in the adjusted risk of all-cause mortality (aHR, 0.77; 95% CI, 0.26-2.44; P = 0.653). There were no differences in the adjusted risk of loss of primary patency comparing other veins to GSV (HR, 1.53; 95% CI, 0.85-2.76; P = 0.154) and prosthetic conduits to GSV (HR, 0.85; 95% CI, 0.57-1.26; P = 0.422). ConclusionsThis large study shows that among patients undergoing OPAR, 1-y primary patency does not differ between conduit types. However, prosthetic conduits are associated with significantly higher risk of amputation and death compared to GSV among symptomatic patients. Though non-GSV autologous veins are less often used for OPAR, they have comparably acceptable outcomes as GSV.