Open Lower Extremity Revascularization Research Articles

Mortality and Morbidity After Open Surgical Lower Extremity Revascularization in Patients With Peripheral Artery Disease and Concurrent Abdominal Stoma.

Patients with peripheral artery disease (PAD) often require treatment with open lower extremity revascularization (LER). Patients with PAD often have other comorbidities and associated conditions that affect procedural outcomes, including abdominal stomas. The aim of this work is to investigate the impact that stomas may have on postoperative outcomes and complications. We performed a 5-year (2016-2020) analysis of the Nationwide Readmission Database. We identified all adult patients undergoing open LER. These patients were categorized into 2 groups: stoma and no-stoma. Propensity score matching (1:1) was used to control for demographics and comorbidities. Index admission outcomes and readmission rate were examined. 212,275 open LER patients were identified. A matched cohort of 3088 patients (1:1 stoma vs no-stoma) was obtained. Patients with stomas had higher rates of several postoperative complications: acute posthemorrhagic anemia (29.1%, P < 0.01), acute kidney injury (21.4%, P < 0.001), index sepsis (10.3%, P < 0.001), and index SSI (2.8%, P < 0.001). There were no significant statistical differences between the 2 groups for acute myocardial infarction. Those with stomas had worse outcomes: greater in-hospital mortality (4.7%, P < 0.05), length of stays (median 7 days, P < 0.001), total charges (median 108,037 dollars, P < 0.001), discharges to long-term care facilities (30.8%, P < 0.001), discharges to their own homes needing home health care (30.1%, P < 0.001), 30-day readmission rates (23.2%, P < 0.01), and 30-day readmission mortality (6.1%, P < 0.01). Concurrent abdominal stoma is associated with increased postoperative morbidity and mortality after open LER. Further prospective studies are needed to validate these results.

Abstract 1150: Effect Of Diabetes On Clinical Outcomes In Patients With Peripheral Arterial Disease Undergoing Lower Extremity Revascularization: A Systematic Review And Meta-analysis

Background: Peripheral arterial disease (PAD) is highly prevalent and has a well-known association with diabetes. It is still unknown if diabetes worsens clinical outcomes after lower extremity revascularization (LER). Research question: What is the impact of diabetes on clinical outcomes in patients with PAD undergoing LER. Goals: In this meta-analysis, we assessed the effect of diabetes on mortality, major limb amputation, and major adverse cardiovascular events (MACE) in patients with PAD following endovascular or open LER during the perioperative period and within 30 days of follow-up. Methods: We performed a systematic search of PubMed, Embase, and Cochrane databases to December 2023, including studies that compared the clinical outcomes of patients with diabetes and without diabetes following LER procedure. Review Manager 5.4 was used for statistical analysis. I 2 statistics were used to examine heterogeneity. A random-effects model was applied to all analyses. Results: Of the 3,810 articles screened, five observational studies with 55,444 patients were included. A total of 51.13 % had diabetes. There was no significant association between diabetes and mortality (RR 0.96; 95 % confidence interval (CI) 0.74 - 1.26; I 2 = 69%; P = 0.79; Figure 1A). However, diabetes was associated with a significantly increased risk of major limb amputation by 50% (RR 1.50; 95 % CI 1.03 - 2.21; I 2 = 94%; P = 0.04; Figure 1B), and an 18% significantly higher risk of experiencing MACE (RR 1.18; 95 % CI 1.08 - 1.29; I 2 = 0%; P = 0.0005; Figure 1C). Conclusion: Our findings suggest that diabetes is associated with an increased risk of major amputation and MACE but not with mortality in patients following LER.

Impact of regional differences and neighborhood socioeconomic deprivation on the outcomes of patients with lower extremity wounds evaluated by a limb-preservation service

ObjectiveManagement of lower extremity (LE) wounds has evolved with the establishment of specialized limb preservation services. Although clinical factors contribute to limb outcomes, socioeconomic status and community factors also influence the risk for limb loss. The Distressed Community Index (DCI) score is a validated index of social deprivation created to provide an objective measure of economic well-being in United States communities. Few studies have examined the influence of geographic deprivation on outcomes in patients with LE wounds. We examined relationships between socioeconomic deprivation and outcomes of inpatients evaluated by a dedicated limb preservation service (Functional Limb Extremity Service [FLEX]). MethodsInpatients referred to FLEX over a 5-year period were included. Wound, Ischemia, foot Infection (WIfI) staging was collected. DCI scores were determined using seven indices based on ZIP Code. Outcomes included any minor or major amputations, any endovascular or open LE revascularization, or wound care procedures. Disease etiology, demographic, and anthropometric data were collected. Associations between neighborhood deprivation and limb-specific outcomes were evaluated in models for the DCI and each of its components separately. ResultsA total of 677 patients were included. Thirty-eight percent were female, with a mean age of 64 years. Sixty percent had WIfI stage 3 or 4 risk of amputation, and 43% had WIfI stage 3 or 4 risk of revascularization. Mean ankle-brachial index and toe pressure were 0.96 (standard deviation [SD], 0.43) and 80 (SD, 57) mmHg. Thirty-five percent were non-White. Amputation was performed in 31% of patients, whereas 17% underwent revascularization. The mean distress score was 64 (SD, 24). Mean DCI scores did not differ across WIfI scores. Likewise, overall DCI distress score was not related to any of the outcomes in univariable or multivariable linear regression models. In univariable linear regression models for amputation, higher poverty rate (odds ratio for SD increase 1.20; 95% confidence interval, 1.02-1.42; P = .025) was significantly associated with the outcome. In multivariable models, neither DCI distress score nor any of its components remained significantly associated with the outcome. ConclusionsDespite known racial disparities in limb-specific outcomes, an aggregate measure of community level distress was not found to be related to outcomes. Although the poverty rate demonstrated a significant relationship with amputation in univariable analysis, this association was not found in multivariable models. Notably, non-White race emerged as a predictor of amputation, underscoring the importance of addressing racial disparities in LE outcomes. Further investigation of potential determinants of LE outcomes is needed, particularly the interaction of such factors with race.

Association Between Complications after Vascular Surgery and Prolonged Postoperative Opioid Use

Few studies have looked at the long-term risk of opioid use following major vascular surgery and no study has investigated the potential association between major complications and prolonged opioid use. We analyzed a population-based database linked to a prescription database to investigate factors associated with prolonged opioid use following major vascular surgery. This population-based cohort study included all adults who underwent open lower extremity revascularization (LER) or non-ruptured abdominal aortic aneurysm repair (open [AAA] and endovascular [EVAR]) in the province of Ontario, Canada, between 2013-2018. Prolonged opioid use was defined as 2 or more opioid prescriptions filled 6-12 months following surgery. Potential predictors of prolonged use were explored using modified Poisson regression with a generalized estimating equation (GEE) approach to account for the clustering of patients within physicians and institutions. This study included a total of 11,104 patients with 5,652 patients undergoing open LER, 3,285 patients undergoing EVAR, and 2,167 patients undergoing AAA. The rates of prior opioid use were 35.4% for LER, 15.8% for AAA and 14.3% for EVAR. Major complication rates following each procedure were 59.5% for AAA, 35.1% for LER, and 21.0% for EVAR. Following surgery, prolonged opioid use was identified in 26.1% of LER, 13.2% of AAA, and 11.6% of EVAR patients. The strongest predictor of prolonged opioid use was prior use with an OR of 13.27 (95%CI10.63-16.57) for AAA, 11.24 (95%CI 9.18-13.75) for EVAR, and 4.69 (95%CI 4.16-5.29) for LER. The occurrence of a major complication was only associated with prolonged opioid use for patients undergoing LER (OR 1.10; 95% CI:1.03-1.19), while it had a protective effect on patients undergoing EVAR (OR 0.83; 95% CI 0.69-0.99) and no association for patients undergoing open AAA repair (OR 1.11; 95% CI: 0.95-1.29). Older age was also protective with a reduced rate of prolonged opioid use for every 10 years of age increase: AAA (OR 0.87; 95% CI 0.77-0.99); EVAR (OR 0.83; 95% CI: 0.76-0.91); and LER (OR 0.91; 95% CI: 0.87-0.94). Prolonged opioid use is common following major vascular surgery, occurring in over 10% of patients undergoing either open or endovascular aneurysm repair and over 25% of patients undergoing open lower extremity revascularization. Prior opioid use is the strongest predictor for prolonged use, while the occurrence of postoperative complications is associated with a slight increased risk of prolonged use in patients undergoing lower extremity revascularization. These patient populations should be targeted for multimodal methods of opioid reduction following their procedures.

Vascular Surgery Trainees' Experience with Open Lower Extremity Revascularization in an Era of Endovascular-First Therapy

The impact of the adoption of endovascular-first therapies for lower extremity revascularization on vascular trainees’ experience with open bypass is not known. We sought to determine trends in open versus endovascular lower extremity revascularization case volumes among graduating vascular fellows (5+2) and integrated vascular residents (0+5). We reviewed the Accreditation Council for Graduate Medical Education 2012-2021 case log data for graduating vascular surgery fellows (5+2) and integrated residents (0+5). We retrieved the mean number of femoropopliteal and infrapopliteal revascularization procedures carried out by each trainee group, both open and endovascular. The means were plotted against time. A Mann Kendall test was conducted to detect trends in the average number of cases performed by vascular graduates. Between 2012 and 2021, integrated vascular residents graduated with an average of 21.9 femoropopliteal and 22.5 infrapopliteal bypasses which were 4.4 ± 1.4 and 3.0 ± 1.9 more than vascular surgery fellows, respectively. For both trainee groups, the mean number of open procedures—femoropopliteal or infrapopliteal—was consistent over the course of the years with no statistically significant trend observed (Figs 1 and 2). Integrated vascular residents graduated with an average of 47.9 femoropopliteal and 22.7 infrapopliteal endovascular procedures, which were 6.2 ± 2.9 and 3.1 ± 1.7 more than vascular surgery fellows, respectively. We observed a statistically significant increase in the mean number of femoropopliteal and infrapopliteal endovascular procedures in this time period –in both trainee groups. The mean number of femoropopliteal endovascular cases increased by 105.5% (31.1 to 63.9; P < .001) for integrated residents and 110.3% (26.2 to 55.1; P < .001) for vascular fellows. Likewise, the mean number of infrapopliteal endovascular cases increased by 120.3% (14.3 to 31.5; P < .001) for integrated residents and 94.1% (13.6 to 26.4; P < .001) for vascular fellows. The overall case volume of femoropopliteal and infrapopliteal procedures, combining open and endovascular techniques, increased for both trainee groups, which is mainly due a significant increase in peripheral vascular intervention volume. The total case volume of lower extremity revascularization has increased for all vascular trainees but graduates of integrated residency programs have a more robust experience. Despite a significant rise in endovascular case volume, however, the average number of open bypass procedures performed by graduating vascular surgery trainees is not affected and has remained stable.Fig 2Trends in open infrapopliteal bypass revascularization.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Surgical site infection after open lower extremity revascularization associated with doubled rate of major limb amputation

ObjectiveSurgical site infection (SSI) after open lower extremity revascularization is a relatively common complication associated with increased hospital stays, graft infection, and in severe cases, graft loss. Although the short-term effects of SSI can be significant, it has not been considered a complication that increases major limb amputation. The purpose of this study was to determine the association of SSI with outcomes in patients undergoing surgical revascularization for peripheral arterial disease. MethodsWe analyzed nationwide Vascular Quality Initiative (VQI) data from the infrainguinal bypass module from 2003 to 2017. The cohort included adults who underwent open lower extremity bypass for symptomatic peripheral arterial disease and had at least one follow-up record. Weighted Kaplan-Meier curves and Cox proportional hazards regression were used to assess the association between SSI and 1-year mortality and major limb amputation. Inverse-probability of treatment weights were used to account for differences in demographics and patient characteristics and allow for ‘adjusted’ Kaplan-Meier curves. ResultsThe analysis included 21,639 patients, and 1155 (5%) had a reported SSI within 30 days of surgery. Patients with SSI were more likely be obese (41% vs 30%), but there were no other clinically relevant differences between demographics, comorbidities, and bypass details. After weighting, patients with SSI were almost twice as likely to undergo major amputation by 6 months (hazard ratio, 1.84; 95% confidence interval, 1.07-3.17). The association with SSI and increased amputation rates persisted at 1 year. The association of SSI on amputation was no different based on preoperative Rutherford class (P = .91). The association between SSI and 1-year mortality rate was not statistically significant (hazard ratio, 1.15; 95% confidence interval, 0.91-1.46). ConclusionsSSI is more common in obese patients, and patients who develop an SSI are observed to have a significantly increased rate of limb amputation after open lower extremity revascularization.

Outcomes After Femoropopliteal Bypass in Octogenarians

Open lower extremity revascularization is controversial for octogenarians; however, the indications for surgical bypass are greater in the elderly population. The aim of this study was to compare the postoperative outcomes between octogenarians and nonoctogenarians after femoropopliteal bypass surgery.

Diagnosis and Treatment of Lymphatic Complications of the Groin Following Open Lower Extremity Revascularization with Plastic Surgery Closure

Lymphatic complications following vascular procedures involving the groin require prompt treatment to limit morbidity. Several treatments have been described, including conservative management, aspiration, sclerotherapy, and direct lymphatic ligation with or without a muscle flap have been described. To date, there is no data indicating which treatment results in the shortest time to recovery. We sought to address this gap by conducting a retrospective cohort study. We reviewed all patients who developed a lymphatic complication after undergoing an open revascularization procedure in the groin between 2014 and 2020 in which plastic surgery was involved in the closure. A control group consisted of patients from the same timespan who did not develop a lymphatic complication. Demographics, comorbidities, operative details, and outcomes were compared between these groups. For cases identified with a lymphatic complication, the method of diagnosis, culture data, and treatment details were collected, and outcomes were compared for surgical management versus sclerotherapy. There were 27 lymphatic complications and 60 control patients. The complication group had a higher incidence of aortofemoral bypass (25.8% vs. 8.3%, P=0.04), and a lower incidence of femoral-to-distal bypass (11.1% vs. 45.0%, P < 0.01). Daily drain output volume from postoperative days 1-5, and days 6-10, was significantly higher in the complication group than in the controls (194.0 vs. 44.0, P < 0.01; and 429.5 vs. 35.0, P < 0.01, respectively). In the lymphatic leak group, 16 patients (59.3%) had surgical treatment and six (22.2%) had sclerotherapy. Of those who had surgery, 71.4% had successful outcomes without the need for an additional intervention, whereas all of the patients analyzed who were treated with sclerotherapy had successful outcomes without further intervention. The average time to resolution was significantly shorter for surgery than for sclerotherapy (38.7 vs. 86.0 days, P=0.03). Daily postoperative drain volume can assist with early diagnosis of a lymphatic leak in the groin following an open revascularization procedure. Sclerotherapy and surgery were each successful, but surgery resulted in significantly shorter times to resolution. In the appropriate candidates, surgery should be considered first line management of a lymphatic leak.

Plasma Hydrogen Sulfide Is Positively Associated With Post-operative Survival in Patients Undergoing Surgical Revascularization.

Objective: Hydrogen sulfide (H2S) is a gaseous signaling molecule and redox factor important for cardiovascular function. Deficiencies in its production or bioavailability are implicated in atherosclerotic disease. However, it is unknown if circulating H2S levels differ between vasculopaths and healthy individuals, and if so, whether H2S measurements can be used to predict surgical outcomes. Here, we examined: (1) Plasma H2S levels in patients undergoing vascular surgery and compared these to healthy controls, and (2) the association between H2S levels and mortality in a cohort of patients undergoing surgical revascularization.Methods: One hundred and fifteen patients undergoing carotid endarterectomy, open lower extremity revascularization or lower leg amputation were enrolled at a single institution. Peripheral blood was also collected from a matched control cohort of 20 patients without peripheral or coronary artery disease. Plasma H2S production capacity and sulfide concentration were measured using the lead acetate and monobromobimane methods, respectively.Results: Plasma H2S production capacity and plasma sulfide concentrations were reduced in patients with PAD (p < 0.001, p = 0.013, respectively). Patients that underwent surgical revascularization were divided into high vs. low H2S production capacity groups by median split. Patients in the low H2S production group had increased probability of mortality (p = 0.003). This association was robust to correction for potentially confounding variables using Cox proportional hazard models.Conclusion: Circulating H2S levels were lower in patients with atherosclerotic disease. Patients undergoing surgical revascularization with lower H2S production capacity, but not sulfide concentrations, had increased probability of mortality within 36 months post-surgery. This work provides insight on the role H2S plays as a diagnostic and potential therapeutic for cardiovascular disease.

Reintervention Index After Open and Endovascular Lower Extremity Revascularization in the Vascular Quality Initiative–Medicare Linked Datasets

Endovascular therapy has become the preferred initial strategy for lower extremity revascularization (LER) for patients with peripheral arterial disease (PAD) despite the paucity of data on its durability compared with open LER. Current outcome measures have focused on patency and freedom from reintervention; however, the frequency of reinterventions is rarely reported. We compared the long-term outcomes of open and endovascular LER, focusing on the frequency of reinterventions.

The Reintervention Index: A New Outcome Measure for Comparative Effectiveness of Lower Extremity Revascularization

Reinterventions after lower extremity revascularization (LER) are common. Current outcome measures assessing durability of revascularization rely on freedom from reintervention but do not account for the frequency of repeated LER. The aim of this study is to compare the reintervention index, defined as the mean number of repeat LER, after open and endovascular revascularization. We hypothesized that endovascular procedures have reduced durability and increased frequency of reinterventions. A retrospective review of the charts of consecutive patients undergoing LER for peripheral artery disease (PAD) in 2013-2014 by multiple specialties in a tertiary care center was performed. Patients were divided into open and endovascular groups based on the first LER procedure performed during the study period. Patient characteristics and outcomes were compared between the 2 groups. Multivariable regression was performed to determine factors associated with reintervention. There were 367 patients (Endo=316, Open=51). A total of 211 patients underwent 497 reinterventions (reintervention rate=57.5%, reintervention index=2.35±2.02 procedures [range 1-11]). Patients in the open group were more likely to be smokers (P=0.018) and to have prior open LER (P=0.003), while patients in the endovascular group were older (P<0.001) and more likely to have cardiovascular comorbidities. On follow-up, there was no difference in overall or ipsilateral reintervention rates or reintervention indices between endovascular and open LER. Major amputation was significantly higher after open LER (19.61% vs. 8.54%, P=0.013) but there was no difference in survival (P=0.448). Multivariable analysis did not show a significant relationship between type of procedure and reintervention. The reintervention index provides a measure to assess the frequency of repeat LER. Patients with PAD, in this study, are afflicted with similar extent of reinterventions after open and endovascular LER.

Rapid increase in hybrid surgery for the treatment of peripheral artery disease in the Vascular Quality Initiative database

ObjectiveAdvances in technology have increased the use of endovascular therapy for lower extremity revascularization (LER), but the impact on hybrid surgery has not been studied. This study aims to (1) investigate the contemporary national trends in frequency of hybrid LER and (2) compare the outcomes of open bypass (BYP) and hybrid surgery for isolated femoropopliteal revascularization. MethodsUsing the national Vascular Quality Initiative database from 2010 to 2017, all patients receiving bypass or hybrid LER for PAD were identified. A trend of all hybrid LER compared with open LER was obtained. Next, only patients who underwent hybrid or open isolated femoropopliteal LER were identified. Patients treated with hybrid surgery underwent femoral endarterectomy and antegrade endovascular intervention of the femoropopliteal vessels (HYB), whereas patients treated with BYP underwent femoral endarterectomy and femoropopliteal bypass. These two groups of patients were matched based on age, gender, race, indication, ambulatory status, emergency status, diabetes, hypertension, coronary artery disease, chronic obstructive pulmonary disease, and hemodialysis. Patient characteristics and the perioperative and 1-year outcomes of the two groups were compared. ResultsThe overall rate of hybrid LER procedures increased from 6.1% in 2010 to 32% in 2017 (P = .03). Hybrid LER was significantly more commonly used in patients with claudication (47%) and BYP surgery was used in patients with tissue loss (38.5%; P = .019). There were 456 HYB and 2665 BYP for isolated femoropopliteal revascularization. After propensity matching, the cohort comprised 425 patients in each group. HYB was associated with lower rate of myocardial infarction (1.9% vs 5.7%; P = .005) and renal complications (2.1% vs 6.7%; P = .003), length of stay (4.7 vs 6.1 days; P = .001), and higher rate of discharge to home (90.8% vs 81.4%; P < .001) compared with BYP. There was no significant difference in 30-day mortality (HYB 1.5% vs BYP, 2.5%; P = .44). The 1-year outcomes comparison suggested that patients in the BYP group had a higher likelihood of improvement in ambulatory status compared with patients in HYB group (16.7% vs 7.7%; P = .044). However, Kaplan-Meier analysis showed no difference in overall survival (P = .13) or amputation-free survival (P = .057) between the two groups. There was no statistical difference in graft patency, limb loss, or secondary interventions. ConclusionsHybrid LER for PAD has been increasingly used and accounts for up to one-third of open LER in the Vascular Quality Initiative. Hybrid femoropopliteal revascularization improves perioperative outcomes compared with femoropopliteal bypass. However, the 1-year outcomes between the two procedures are comparable, suggesting that hybrid femoropopliteal revascularization should be favored in high-risk patients because of its perioperative advantages.

Outcomes of Octogenarians in Open Lower Extremity Revascularization

Introduction - Open vascular surgical outcomes in octogenarians are controversial. Octogenarian patients are often not considered suitable candidates for open revascularization due to their advanced cumulative risk factors of smoking, hypertension, hyperlipidemia, diabetes mellitus, and obesity increasing their perioperative and postoperative risks which may be associated with a higher mortality rate. The aim of this study was to examine the differences in outcomes between non-octogenarians and octogenarians following lower extremity bypass surgeries. Methods - The lower extremity open procedure-targeted American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried in this study using data from 2011-2014. Analyses were performed separately on patients undergoing lower extremity bypass surgery (femoral-distal, popliteal-distal, and femoral-popliteal bypass). Disease, patient, clinical, and procedural characteristics were evaluated using univariate and bivariate analyses (student t, χ2, and Fisher’s exact tests). Independent risk factors and trends of 30-day postoperative outcomes of interest (mortality, readmission, loss of patency [LOP], and wound infection) were assessed using multivariate logistic regression. Results - The analysis included 2359 femoral-distal bypass patients (19.8% ≥80 years of age); 763 popliteal-distal bypass patients (16.51% ≥80 years of age); and 4894 femoral-popliteal bypass patients (14.22% ≥80 years of age). Thirty-day mortality was low in all surgery types (1.02% femoral-popliteal; 1.97% popliteal-distal; and 1.31% femoral-distal). Age was not found to be a significant predictor of our outcomes of interest in either the femoral-distal or popliteal-distal bypass cohorts. In the femoral-popliteal bypass cohort however, age ≥80 years was an independent predictor of mortality (OR 3.93, 95% CI 2.22-6.98, p<0.001). Emergent procedures (OR 3.15, 95% CI 1.5-6.89, p=0.004) and pre-operative wound infection (OR 2.41, 95% CI 1.36-4.27, p=0.002) were also important predictors of mortality. Age was found to be an independent predictor of LOP (OR 2.2, 95% CI 1.33-3.65, p=0.002), readmission (OR 1.29, 95% CI 1.02-1.64, p=0.033), and postoperative wound infection (OR 1.74, 95% CI 1.45-2.07, p<0.001). A statistically significant trend was found for increasing BMI and risk of readmission (p<0.001). Conclusion - Age ≥80 years old is a significant independent predictor of mortality, loss of patency, readmission, and wound infection following femoral-popliteal bypass surgery. Smaller sample size and power restrictions limited our ability to analyze the femoral-distal and popliteal-distal subgroups. Given a mortality odds ratio of 3.93, yet also a low overall 30-day mortality, it may be useful to consider the benefit in quality of life of this procedure while also examining therapeutic alternatives for severe PAD in this older age group.

Dermabond and Tegaderm: A Better Surgical Incision Dressing

Surgical site infections (SSIs) are a common source of morbidity with vascular surgery incisions, especially in the groin. Single institution case series have widely varying, but high incidences of groin wound infection after open lower extremity revascularization. Optimally, a dressing that did not require changes, had low cost, and was water resistant would be optimal in these patients. We developed and validate a new dressing utilizing Dermabond (Ethibond™) and Tegaderm™ for vascular surgery incisions that could simplify and reduce postoperative SSIs. In this initial experience, we reviewed 94 patients. Of the 94 patients, 0 had signs of infection superficial or deep, dehiscence, or evidence of nonhealing. Gluing a Tegaderm to an incision using Dermabond is a novel and easy way to perform dressing that reduces wound infection, increases patient comfort, avoids dressing changes, and allows visualization of the wound.

Vascular surgery trends in Australia: 2001-2015: less open surgery, less limb loss and more endovascular intervention.

The prevalence of peripheral arterial disease (PAD) in Australia is currently poorly characterized. The risk factor profile for PAD is changing with the population ageing, diabetes increasing and smoking rates declining. The management of PAD is also evolving, with advances in medical management and endovascular technique. The trends in PAD prevalence and surgical management have implications for preventative medicine, the Australian health system and vascular surgery. We report and analyse trends in PAD surgical intervention performed between 2001 and 2015. Data was extracted from the National Hospital Morbidity Database procedural item code records. Procedural numbers of endovascular lower extremity revascularization (LER); open LER; minor and major lower extremity amputations (LEA) between 2001 and 2015 in adults ≥45 years were included. Results were population-adjusted and age-stratified using census information from the Australian Bureau of Statistics to analyse changes in intervention rates. Linear regression analyses were performed to calculate the average annual change in procedures per capita (100 000). From 2001 and 2015, per capita (100 000 population) volume of endovascular LER increased 89%, open LER decreased 70%, major LEA decreased 65% and minor LEA increased 14%. The most remarkable changes were in the ≥85-year-old cohort, with endovascular procedures per capita increasing 188%; coinciding with both open LER and major LEA decreasing by 73% between 2001 and 2015. Australian hospital data between 2001 and 2015 shows that endovascular LER interventions and minor LEA have significantly increased per capita in Australians ≥45 years. In contrast, both open LER and major LEA rates have significantly decreased in the same cohort.

Lower Extremity Revascularization With Transmetatarsal Amputation Improves Healing and Reduces Major Amputation

A transmetatarsal amputation (TMA) allows patients with forefoot wounds to maintain ambulatory function and preserves a sensate heel and ankle. However, healing after TMA is often compromised in older patients by peripheral artery disease (PAD). The aim of this study was to investigate the effect of lower extremity revascularization (LER) on TMA healing and prevention of major amputation. A retrospective review was conducted of all patients who had a TMA at three centers of a multicenter vascular practice from January 1, 2008, to December 31, 2016. In January 2012, a multidisciplinary limb salvage team consisting of vascular surgeons and podiatrists was established. Data on demographics, procedural details, and outcomes were collected. A total of 124 patients had 134 TMAs with a median follow-up of 1221 days (interquartile range [IQR], 730-1757 days). The mean age was 60.9 ± 11.5 years; 81% were men, 87% had diabetes, 56% had PAD, and 31% had coronary artery disease (CAD). Of 134 TMAs, 68% (91) healed, 10% (14) had recurrent wounds, and 22% (29) failed, requiring above- or below-knee amputation (AKA/BKA). Patients with PAD/CAD had a significantly lower healing rate (51/84 [61%] vs 40/50 [80%]; P = .021) and significantly higher AKA/BKA rate (24/84 [29%] vs 5/50 [10%]; P = .012). LER was associated with significantly improved TMA healing rates (36/52 [69%] vs 15/32 [47%]; P = .042). Open LER had a significantly higher healing rate (16/31 [52%] vs 4/20 [20%]; P = .024) and lower AKA/BKA rate (2/31 [6%] vs 9/22 [41%]; P = .002) than endovascular LER. By Kaplan-Meier analysis, the median time to healing was 295 days (IQR, 99-754 days). The median time to AKA/BKA was 1062 days (IQR, 471-1595 days). In a multivariable Cox model, LER was associated with a lower risk (hazard ratio, 0.43; P = .039) of AKA/BKA, and PAD/CAD was associated with a higher risk (hazard ratio, 5.41; P = .001); 70% (94/134) of the TMAs were performed by the multidisciplinary limb salvage team, and there was an increase in TMA for Wound, Ischemia, and foot Infection (WIfI) stage 3/4 wounds (84/94 [89%] vs 28/40 [70%]; P = .006). In a multivariable Cox model, there was no change in TMA healing or AKA/BKA rates despite the higher WIfI category. TMA is a successful and durable procedure for patients with advanced foot wounds. Whereas TMA healing is time and labor intensive, aggressive use of LER can achieve TMA healing and avoid major amputation in older patients with PAD.

Abstract 122: Increased Plasma Sulfide in Vascular Surgery Patients Correlates with Reduced Post-Operative Mortality

Objective: Hydrogen sulfide (H 2 S) is an endogenously produced gaseous signaling molecule with the potential to modulate vascular functions. Free plasma sulfide can be measured by various techniques, but no consistent relationship with cardiovascular disease has yet emerged. For example, sulfide levels are decreased in CHF patients, but elevated in PAD. We therefore sought to compare plasma sulfide levels from PAD patients to matched controls, and explore links between mortality rates and sulfide levels using two assays. Approach &amp; Results: Patients undergoing carotid endarterectomy (n=49), open lower extremity revascularization (n=44) or leg amputation (n=22) were enrolled (mean age 68.9±9.6, 67% male). Blood was collected from 20 matched control patients, without PAD or CAD (mean age 67.9± 1.3, male 65%). Plasma sulfide was measured using two methods, first detection using lead acetate, and second using mass spectrometry. Controls had increased plasma sulfide levels measured by both methods (lead acetate, Fig. A; mass spec, Fig. B) compared to PAD patients (p&lt;0.001, p=0.013). Also, PAD patients were divided into high (n=57) and low (n=58) sulfide (lead acetate) groups by median split. Low sulfide PAD patients had increased probability of post-op mortality (p=0.0337, Fig. C). To determine the source of plasma H 2 S detected by lead acetate, we tested the effects of detergent and proteolytic denaturation of plasma as well as of reducing agents on H 2 S release. We found denaturation increased plasma sulfide release, and that dithiothreitol was most effective at liberating H 2 S, suggesting bound sulfane sulfur as source of H 2 S detected using the lead acetate assay. Conclusions: Plasma free and bound sulfide were reduced in PAD patients compared to controls, and correlated with mortality. These findings provide evidence linking circulating sulfide to clinically meaningful events, and support directed H 2 S investigations toward diagnostic and therapeutic purposes.

IP205. Outcomes After Open Lower Extremity Revascularization in Patients With Chronic Kidney Disease

IP205. Outcomes After Open Lower Extremity Revascularization in Patients With Chronic Kidney Disease

Predictors of surgical site infection after open lower extremity revascularization

ObjectiveSurgical site infection (SSI) after open lower extremity bypass (LEB) is a serious complication leading to an increased rate of graft failure, hospital readmission, and health care costs. This study sought to identify predictors of SSI after LEB for arterial occlusive disease and also potential modifiable factors to improve outcomes. MethodsData from a statewide cardiovascular consortium of 35 hospitals were used to obtain demographic, procedural, and hospital risk factors for patients undergoing elective or urgent open LEB between January 2012 and June 2015. Bivariate comparisons and targeted maximum likelihood estimation were used to identify independent risk factors of SSI. Adjusted odds ratios (ORs) were calculated for patient demographics, comorbidities, operative details, and hospital-level factors. ResultsOur study population included 3033 patients who underwent 703 femoral-femoral bypasses, 1431 femoral-popliteal bypasses, and 899 femoral-distal vessel bypasses. An SSI was diagnosed in 320 patients (10.6%) ≤30 days after the index operation. Adjusted patient and procedural predictors of SSI included renal failure currently requiring dialysis (OR, 4.35; 95% confidence interval [CI], 3.45-5.47; P < .001), hypertension (OR, 4.29; 95% CI, 2.74-6.72; P < .001), body mass index ≥25 kg/m2 (OR, 1.78; 95% CI, 1.23-2.57; P = .002), procedural time >240 minutes (OR, 2.95; 95% CI, 1.89-4.62; P < .001), and iodine-only skin preparation (OR, 1.73; 95% CI, 1.02-2.91; P = .04). Hospital factors associated with increased SSI included hospital size <500 beds (OR, 2.22; 95% CI, 1.09-4.55; P = .028) and major teaching hospital (OR, 1.66; 95% CI, 1.07-2.58; P = .024). SSI resulted in increased risk of major amputation and surgical reoperation (P < .01), but did not affect 30-day mortality. ConclusionsSSI after LEB is associated with an increase in rate of amputation and reoperation. Several patient, operative, and hospital-related risk factors that predict postoperative SSI were identified, suggesting that targeted improvements in perioperative care may decrease complications and improve vascular patient outcomes.

Access to Posthospitalization Acute Care Facilities is Associated with Payer Status for Open Abdominal Aortic Repair and Open Lower Extremity Revascularization in the Vascular Quality Initiative

Uninsured patients may not have access to postacute care facilities that play an important role in clinical recovery, and functional outcomes after vascular surgery. We sought to determine whether discharge disposition is associated with insurance status. We retrospectively reviewed data from the Vascular Quality Initiative® for patients who underwent open abdominal aortic repair, infrainguinal bypass, or suprainguinal bypass (SB) between January 2012 and July 2015. Mixed-effects logistic regression analysis with clustering at the surgeon and facility level was used to calculate 95% confidence intervals for discharge disposition to home, skilled nursing facility (SNF) or rehabilitation (Rehab) facility by payer status (Medicare, Medicaid, Commercial, Military/Veterans Affairs, Non-US Insurance, or Self-pay), with adjustment for patient, operative, and postoperative characteristics. The study cohort comprised 18,478 procedures (open abdominal aortic repair=2,817; infrainguinal bypass=11,572; suprainguinal bypass=4,089) after we excluded procedures with missing data and in-hospital deaths. Twenty-four percent of the cohort was discharged to an SNF or Rehab site. On univariate analysis, the odds ratio (OR) of discharge home was 4.38 (95% CI: 3.33-5.77) for self-pay as compared to Medicare. On mixed-effects analysis, the adjusted odds of discharge home for self-pay as compared to Medicare remained high (OR=3.09; 95% CI: 2.23-4.26), after adjustment for age, gender, race/ethnicity, preoperative ambulatory status, number of comorbidities, case urgency, total operative time, presence of a postoperative complication, procedure type, and length of stay. Adjusted odds for discharge to SNF (OR=0.26; 95% CI: 0.15-0.46) and Rehab (OR=0.50; 95% CI: 0.35-0.72) were lowest for self-pay status. Access to postacute care facilities is associated with insurance status. Self-pay (uninsured) patients are less likely to have access to discharge services that may aid clinical recovery, and functional outcomes after major vascular surgery.