Infrainguinal Bypass Grafts Research Articles

PS128. In-Hospital and Post-Discharge Venous Thromboembolism after Vascular Surgery

Recent single-center reports demonstrate high (up to 10%) incidence of postoperative venous thromboembolism (VTE) after major vascular surgery. Moreover, vascular patients rarely receive prolonged prophylaxis despite evidence it reduces post-discharge events. The objective of our study was to use a national, prospective, multicenter database to (1) define the frequency of overall and post-discharge VTE after major vascular operations and (2) assess risk factors associated with VTE development. Patients who experienced a VTE after elective vascular procedures (n=45548) were identified from 2007-09 NSQIP database. The vascular procedures included: carotid endarterectomy (CEA; n=20785), open thoracoabdominal aneurysm (TAAA) repair (n=361), thoracic endovascular aortic repair (TEVAR; n=732), open abdominal aortic aneurysm (AAA) repair (n=6195), EVAR (n=7361) and infrainguinal bypass graft (BPG; n=10114). VTE occurred in 332 (0.7%) patients (pulmonary embolisms: 0.2%; deep venous thromboses: 0.6%). TAAA repair had the highest rate of VTE (4.2%), followed by TEVAR (2.2%), open AAA repair (1.7%), BPG (1.0%), EVAR (0.7%), and CEA (0.2%) (P <.0001). Forty-one percent of these VTEs occurred post-discharge. Procedure type, race, general anesthesia, dependent functional status, COPD, CHF, angina, rest pain, and open wound were significantly associated with development of VTE (P < .05). In those experiencing a VTE, overall mortality increased from 1.5% to 6.0% (P <.0001). Postoperative VTE is associated with type of vascular procedure, and is highest after operations in the chest and abdomen/pelvis. About 40% of VTE events in elective vascular surgery patients occurred post-discharge. Future studies should evaluate the benefit of post-discharge VTE prophylaxis in high-risk patients.

Invited commentary

We probably all remember the satisfying sound of the multiphasic Doppler signal immediately after our first successful lower extremity bypass as a trainee, particularly as the foot pinked up when the clamps were removed. Lower extremity revascularization and limb salvage remain cornerstones of vascular surgery education and require intense attention to technical skill, delicacy, and some amount of swiftness. Very few vascular operations or interventions have outcomes that are so black or white when they fail, and the tolerance of success is measured in millimeters and often related to the technical details of the exercise. Volume–outcome relationships are well established for leg bypass, also indicating the precision and technical efficiency required for optimal limb salvage. Dr Scarborough and colleagues from Duke University Medical Center report in this provocative article the negative effect that surgical trainee participation has on early postoperative graft failure when analyzing the National Surgical Quality Improvement Program (NSQIP) database. The finding that having surgical residents as part of the operative team essentially has a 29% higher chance of early failure brings to light several issues plaguing surgical educators and residency program directors. Fortunately, morbidity and mortality are not adversely affected in the propensity-matched data by trainee involvement. In this new era of duty hour restrictions, many attendings already feel the trainees are not operating enough. More and more surgical residents are relying on fellowships or junior faculty positions to be “finishing schools” to successfully transition into practice. Additional pressures on faculty to operate more, faster, and better also affect the level of involvement and autonomy the trainee has during all types of vascular procedures. Findings in this NSQIP analysis may therefore force us to more prospectively and accurately determine what the trainee-related causes are that worsen surgical outcomes. Although I obviously agree with the authors that the solution to this dilemma is not to prohibit trainees from participating in surgery, much more emphasis needs to be placed on skills acquisition and competency assessments as methods to prepare surgical trainees for ultimate success when they are in the operating room. Much like the putting green before a round of golf, the simulation center/skills laboratory needs to be a warm-up zone for surgical trainees. National resources need to be provided to allow program directors to safely and efficiently train the future vascular surgery workforce. Formalized and mentored skills milestones of various vascular technical skills need to be identified, validated, and tested to create a skills curriculum for all future vascular surgeons. Although one-on-one faculty-to-trainee teaching in the operating room can never be completely replaced, those valuable interactions can be made much more meaningful when basic technical skills and operative plans have already been deliberately practiced outside of the operating room environment. Surgical trainee participation during infrainguinal bypass grafting procedures is associated with increased early postoperative graft failureJournal of Vascular SurgeryVol. 55Issue 3PreviewThis study was conducted to determine the potential effect of surgical trainee participation during infrainguinal bypass procedures on postoperative graft patency rates. Full-Text PDF Open Archive

Neutrophil-Lymphocyte Ratio Predicts Graft Patency Following Lower Limb Revascularisation

Background : Graft failure is a significant problem following lower limb revascularisation. We hypothesised that the neutrophil-lymphocyte ratio (NLR), a simple and inexpensive index of systemic inflammation, predicts graft failure.Methods : Consecutive patients undergoing infra-inguinal bypass grafting were identified from a prospective database. All patients underwent routine graft surveillance using Duplex ultrasound. Potential predictors of graft failure (occlusion or ipsilateral amputation) were assessed in univariate and multivariate regression models.Results : Of 126 patients, 79 had patent grafts at 1 year. The only independent predictor of graft failure was the postoperative NLR.Conclusion : Post-operative NLR may be a simple, inexpensive means of focussing surveillance resources on patients at high-risk of graft failure. Its value needs to be confirmed in larger cohorts.

Surgical trainee participation during infrainguinal bypass grafting procedures is associated with increased early postoperative graft failure

This study was conducted to determine the potential effect of surgical trainee participation during infrainguinal bypass procedures on postoperative graft patency rates. Data from the National Surgical Quality Improvement Program (NSQIP) Participant User Files from 2005 through 2009 were retrospectively reviewed, using propensity score matching, to identify all patients undergoing infrainguinal bypass grafting procedures, excluding those who had prior operation ≤30 days of the index procedure. A separate analysis was performed on a subset of procedures from the entire NSQIP sample that was matched on propensity for intraoperative surgical trainee participation. The primary predictor variable was intraoperative surgical trainee participation. The main outcome measure was the 30-day postoperative graft failure rate. For the entire sample of 14,723 NSQIP patients undergoing infrainguinal bypass grafting, 30-day graft failure rates were significantly higher when a surgical trainee participated (5.8%) vs without participation (3.9%; P < .0001). For the cohort of 9234 patients matched on their propensity for intraoperative trainee participation, this difference in graft failure rate remained significant (5.0% with participation vs 4.0% without participation; P = .02). Surgical trainee participation is an independent risk factor for technical failure after infrainguinal bypass grafting. Prospective evaluation is needed to determine the cause of this increase in graft failure rates for procedures that involve surgical trainees.

Effect of Antiplatelet Agents and Statins on Infrainguinal Bypass Graft Patency: Is There an Impact?

Effect of Antiplatelet Agents and Statins on Infrainguinal Bypass Graft Patency: Is There an Impact?

VASCULAR GRAFT INFECTIONS MANAGEMENT

Introduction: Despite routine antibiotic prophylaxis and refinements in implantation technique, microbial infection of the vascular prostehesis can occur. Infection involving a vascular graft is difficult to eradicate. If not recognized or treated promptly, implant failure will occur by producing sepsis, hemorrhage or thrombosis. Management involves graft excision alone, graft preservation within the implant wound, in/situ graft replacement, or graft excision in conjunction with extra-anatomic bypass grafting. Matherial and method: We retrospectively analysed the operative registers of our clinic as well as the regular archives, from 2000 until 2008, searching for reported graft infections which needed excisions and extraanatomical bypasses or for conservative therapy. There were 50 patients in this interval admitted and treated in Surgical Clinic No.1, out of a total of 950 vascular interventions. 10 of them were early graft infections( 4 months). Using Szilagyi’s classification, 10 were grade I, 17 were grade II and 23 grade III.We followed antibiotic prophylaxis protocols in all of the cases, prior to first vascular intervention. Staphylococcus aureus was the most prevalent pathogen ( 95% ) found affecting our grafts. Results: We performed 20 graft excisions for infrainguinal graft infections, with the removal of the entire graft, radical debridement of infected perigraft tissues, closure of the arteriotomies with monofilament suture and the administration of systemic and topical antibiotics. We attempted graft preservation in 5 cases of infrainguinal prosthetic bypass graft infection( with serial surgical wound debridement, coupled with antibiotic therapy, early muscle flap coverage and repeated wound cultures to identify any development of bacterial resistance or change in the microbial flora). We used the staged approach in 20 cases, beginning with drainage of the perigraft abscess, followed in 2 or 3 days by graft excision and autogenous vein grafting. We performed none in-situ replacements with Rifampin-bonded prosthesis, partly because they were not available until a few years. For the patients with infection localized to only a portion of an aortofemoral graft, we preferred, for the decreased morbidity, the excision of the infected portion of the graft(partial graft excision) and after solving the inguinal infection, a staged extra-anatomical bypass- in cases.As for the gold standard regarding the aortic graft- total graft excision and ex-situ bypass, we only performed 5 of them. 3 patients died and 2 required major amputation. Conclusions: Dissatisfaction with the morbidity and the mortality of treating vascular graft infections, regardless of location, by total graft excision and remote bypass has been the impulse for the expanded application of lately performed in-situ bypasses or even for the prophylactic use of antibiotic-bonded grafts, in carefully selected cases.

Outcome of infra-inguinal bypass grafts using vein conduit with less than 3 millimeters diameter in critical leg ischemia

The purpose of this study was to evaluate the difference in amputation-free survival and patency rates of infra-inguinal bypass grafts in patients with critical leg ischemia (CLI) with vein conduits with an internal diameter <3 mm compared to those with vein conduits with a diameter of ≥ 3 mm. Retrospective analysis of all consecutive patients with CLI undergoing infra-inguinal bypass. Preoperative duplex scan mapping and measurement of potential vein grafts were performed on all patients. Patients were recruited in a 1-year duplex scan graft surveillance program. Primary end points were amputation-free survival and patency rates at 1 year postoperatively. Kaplan-Meier and χ(2) test were used for statistical analysis. Between January 2004 and April 2010, 157 consecutive patients with CLI underwent 171 bypasses using vein conduits (111 men, 46 women; median age, 75 years; range, 45-96 years). Ninety-three bypasses (54.4%) were performed for tissue loss, 44 (25.7%) for gangrene, and for rest pain. Of the 157 patients, 113 (72.0%) had diabetes mellitus, 40 (25.5%) had renal impairment, 131 (83.4%) had hypertension, and 64 (40.8%) had ischemic heart disease. Femoro-popliteal bypass was performed in 38 cases (22.2%), whereas 133 (77.8%) of the bypasses were femoro-distal. Autogenous great saphenous vein (GSV) was used in all cases. All grafts were reversed. The diameter of 31 (18%) vein conduits measured <3 mm (range, 2-2.9 mm) on preoperative duplex scan. One hundred thirty-four grafts had at least 1-year follow-up. The primary, assisted primary, and secondary patency rates at 1 year for vein conduits <3 mm were 51.2%, 82.6%, and 82.6%, respectively, compared to 68.4%, 93.3%, and 95.2%, respectively, in the ≥ 3 mm group. This was only significant for the secondary patency (P = .0392). The amputation-free survival at 48 months was 70.8% for vein conduits <3 mm and 57.3 for vein conduits ≥ 3 mm. This series has shown that primary and assisted primary patency rates in small veins are not significantly different at 1 year but the secondary patency rates are better in the larger veins. Similarly, the amputation-free survival was also comparable. The authors would, therefore, advocate the use of small veins >2 mm in diameter in patients with CLI. Duplex scan surveillance followed by early salvage angioplasty for threatened grafts is needed to achieve good patency rates in both groups.

High Leg Salvage Rate after Infrainguinal Bypass Surgery for Ischemic Tissue Loss (Fontaine IV) is Compromised by the Short Life Expectancy

Most studies analysing the prognosis of infrainguinal bypass surgery (IBS) in patients with critical leg ischemia (CLI) have combined the outcome of patients with rest pain and tissue loss. The aim of the present study was to evaluate amputation-free survival (AFS) after IBS in patients with the most advanced form of peripheral arterial disease, CLI with tissue loss (Fontaine IV), and to analyse the risk factors for an adverse outcome. 636 patients with CLI and tissue loss who underwent unilateral IBS between January 2000 and December 2006 at our institution were included in this retrospective study. At one year, the leg salvage, survival and amputation-free survival rates were 83%, 71% and 55%, respectively, and at five years 76%, 38% and 30%, respectively. In univariate analysis, diabetes was associated with decreased AFS. In multivariate analysis, age, coronary artery disease, chronic pulmonary disease, gangrene and renal insufficiency were independent risk factors for decreased AFS. Infrainguinal bypass grafting results in a high rate of leg salvage. Amputation-free survival was low during the follow-up due to the high mortality of patients with CLI and tissue loss. Several co-morbidities of the CLI patients were associated with decreased amputation-free survival.

Tertiary Patency as a Measure of Active Revascularization Policy for Leg Salvage

An active surgical strategy to save lower limbs of patients with critical leg ischemia includes not only infrainguinal bypass surgery but also repeated surgery when needed. A failed infrainguinal bypass often threatens viability of the patient's legs, at which point a redo bypass procedure with a new graft may be the only alternative to major amputation. We assessed tertiary patency, defined as the whole period of time with a patent infrainguinal graft in a leg, to illustrate future potential of limb salvage surgery after a failed bypass. A total of 593 patients with critical leg ischemia and tissue defects (Fontaine IV) who underwent infrainguinal bypass surgery between January 2000 and December 2005 at our institution were included in this retrospective study. Secondary and tertiary patency rates were 95 ± 1% and 96 ± 3% at 1 month, 75 ± 2% and 82 ± 2% at 1 year, and 61 ± 2% and 70 ± 3% at 5 years, respectively, p = 0.003. Leg salvage rate was 94 ± 1% at 1 month, 83 ± 2% at 1 year, and 78 ± 2% at 5 years. There was no significant difference between leg salvage and tertiary patency rates, p = 0.281. Tertiary patency rate was higher than the secondary patency rate. This result might reflect active limb salvage surgery with satisfactory results. The absence of a gap between tertiary patency and leg salvage rates indicates the importance of a patent infrainguinal bypass graft to save lower limbs of patients with ischemic tissue defects.

Pharmacotherapy to Improve Outcomes in Infrainguinal Bypass Graft Surgery: A Review of Current Treatment Strategies

A total of 12,000 infrainguinal bypass grafts are performed annually in the United Kingdom, with outcomes suboptimal: 20% of above-knee vein grafts require intervention by 3 years. Transatlantic Inter-Society Consensus (TASC) guidelines exist on pharmacological management of peripheral vascular disease patients, however, little is recommended regarding optimum pharmacological management following revascularization to improve graft patency. The current recommendation is that all patients are on an antiplatelet agent following bypass grafting, the only intervention with significant evidence supporting use. This article will review pharmacological strategies aimed at improving the survival of infrainguinal vein grafts and the current evidence base for their use.

Disparities in vascular surgery: Is it biology or environment?

Disparities in health care are well documented for several racial, ethnic, and gender groups. In peripheral arterial disease, differences in prevalence, treatment selection, treatment outcomes, and resulting quality of life have negative effects on some minority groups and women. It may be easy to document disparities, but it is harder to understand their underlying causes. Are there biologic differences between members of racial and ethnic groups that influence disease presentation and outcomes? Or is the socioeconomic environment that surrounds them the true driver of observed differences? This article reviews the evidence for racial and gender disparities in vascular surgery and presents some potential mechanisms that may explain the disparities.

Patient and procedure-related risk factors for adverse events after infrainguinal bypass

Current medical practice urges individual health care facilities and medical professionals to obtain and provide detailed insight in quality of care with the possibility of comparing data between institutions. Adverse event (AE) analysis serves as a mainstay in quality assessment in vascular surgery, but the comparison of AE data between facilities can be complex. The aim of the present study was to assess independent risk factors for AE occurrence: patient, disease and operation characteristics besides general differences between health care facilities. All AEs after infrainguinal bypass graft procedures (BGPs) in three health care facilities in the Netherlands were evaluated. AEs were defined identically in the facilities. Of 601 BGPs performed, 662 AEs were registered. Independent predictors of AEs were female gender (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.39-3.26; P < .01), age >or=60 years (OR, 0.57; 95% CI, 0.34-0.95; P = .03), American Society of Anesthesiologists classification 3-4 (OR, 1.79; 95% CI, 1.01-3.17; P = .05), comorbidities of pulmonary disease (OR, 2.99; 95% CI, 1.67-5.34; P < .01) and diabetes mellitus (OR, 2.49; 95% CI, 1.58-3.94; P < .01), distal anastomosis level at below knee femoropopliteal BGP (OR, 2.01; 95% CI, 1.26-3.22; P < .01), femorotibial BGP (OR, 2.40; 95% CI, 1.37-4.19; P < .01), and popliteopedal BGP (OR, 92.39; 95% CI, 11.13-766.98; P < .01). One health care facility had significantly fewer AEs than the other two (OR, 0.21; 95% CI, 0.13-0.35; P < .01). Age, gender, comorbidity, and type of surgery are all independent predictors of AE occurrence in vascular surgery. After adjustment for differences in these factors, one health care facility still had lower AE occurrence, which needs to be examined further.

Thrombolysis of occluded infra-inguinal bypass grafts: is it worthwhile ?

Background: Thrombosis of an infra-inguinal bypass graft often results in a limb-threatening ischemia. There is no consensus on the optimal management strategy.Aim of the study: To analyse safety and efficacy of catheter-guided intra-arterial thrombolysis to re-open thrombosed infra-inguinal bypass grafts and to identify factors that influence graft patency and limb salvage rate after thrombolytic procedures.Methods: A continuous cohort-study of 106 thrombolytic procedures between 1993 to 2008.Results: Despite a high initial success rate (76%), the mid-term results are less convincing, with a 58% re-occlusion rate at 45 months follow-up. Thrombosed vein grafts, old (2 weeks or more) occlusions, poor run-off and failure to identify or rectify an underlying causative stenosis are determinant for a poor long-term outcome of thrombolytic procedures. Comments: The outcome results of author’s experience are consistent with literature reports. Thrombolysis of occluded infra-inguinal bypass grafts should be limited to selective cases (recent occlusion, prosthetic or vein graft in place since 1 year or more, critical limb ischemia). Despite its obvious advantages, the long-term outcome of thrombolytic procedures is deceiving. The inherent risk of hemorrhagic complications should also be taken in account at the decision making of treatment strategy. The question wether, in general, catheter-guided selective intra-arterial thrombolysis offers a significant advantage over operative revascularisation (thrombectomy or new bypass) remains unanswered. A more selective approach seems to favour thrombolysis as most appropriate strategy in the management of recent (< 2 weeks) thromboses of grafts in place since at least 1 year.

Reallocation of Foundation Programme Doctors From Teams to Wards Reduces Mortality From Proximal Femoral Fracture

Reallocation of Foundation Programme Doctors From Teams to Wards Reduces Mortality From Proximal Femoral Fracture

Secondary Bypass after Infrainguinal Bypass Graft Failure

Patients who suffer failure of a previous infrainguinal bypass graft often present with recurrent ischemia requiring secondary revascularization for limb salvage. These patients pose major challenges for the vascular surgeon. Management strategies vary with the time interval from bypass, the functional status of the patient, the degree of ischemia and the availability of autogenous vein. This article reviews the treatment options for these difficult patients and the results which can be achieved.

A Study to Assess The Efficacy of Balloon Angioplasty of The femoropopliteal Arteries in The Relief of Critical Limb Ischemia (CLI)

Purpose: The aim of the study was to evaluate the results of percutaneous transluminal angioplasty (PTA) of femoropopliteal arteries in patients with critical lower limb ischemia; Materials and methods: From June 2006 till May 2008, 40 patients underwent 40 PTA procedures, 18 were of the superficial femoral artery (SFA), 7 of the popliteal artery, 9 of both arteries and 6 of the common femoral artery (CFA). Twenty-nine procedures were performed for treatment of stenoses and 11 for occlusion. The patients were monitored clinically with non-invasive hemodynamic studies. Results: The technical success rate was 97.5%. Overall primary patency rates at 24 months were 67.5%. Primary patency rates in limbs with occlusion were 45.5% compared with 75.9 in limbs with stenoses. Two major amputations were performed. The overall survival rate was 95%. Conclusion: The 2 years results of femoropopliteal PTA performed for treatment of CLI seemed to be near the results of infrainguinal bypass grafting reported in literature. Because PTA does not preclude the performance of future surgery and associated with low morbidity and mortality rates, it should be a first choice treatment for patients with CLI for selected lesions.

Initial Experience with a New Method of External Polyester Scaffolding for Infrainguinal Vein Grafts

This study aims to evaluate the feasibility of external polyester scaffolding in infrainguinal bypass grafting when available vein material is suboptimal due to varicosity or dilatation. Primary objectives were short-term primary patency, assisted primary patency and secondary patency. Secondary objectives were to assess the rate of graft stenoses, infections and other adverse effects related to the use of external scaffolding. A total of 50 consecutive patients were included in this prospective, multicentre, feasibility study from six centres. The indication for infrainguinal bypass was critical limb ischaemia (64%), severe claudication (34%) or popliteal aneurysm (2%). Indications for the use of the external scaffolding were varicosity of the vein graft, ectatic vein graft or the use of spliced vein grafts with segments of widely differing diameters. Duplex scanning of the graft was done perioperatively and at follow-up visits at 1, 3, 6 and 12 months after operation. Primary patency, assisted primary patency and secondary patency at 6 months were 82.3% (+/-SE 6.2%), 88.6% (+/-SE 4.8%) and 92.1% (+/-SE 4.4%), respectively. Six graft stenoses were detected in duplex surveillance. There were no infections related to polyester mesh. External scaffolding of infrainguinal vein grafts may be a promising innovation. Early results from this multicentre study show that polyester mesh is safe and feasible adjunct to peripheral revascularization enabling the use of otherwise non-optimal vein grafts with acceptable short-term patency.

Predictors of Prosthetic Graft Infection after Infrainguinal Bypass

Background Some patients require major leg amputation after lower-extremity prosthetic bypass for graft occlusion or failure of wound healing, despite a patent graft. Amputation above or below the knee was hypothesized to increase susceptibility to prosthetic graft infection in the ipsilateral extremity. Study Design All patients undergoing implantation of prosthetic infrainguinal arterial bypass grafts identified from a vascular surgical registry during a 12-year period were reviewed. Patient demographic data, comorbid conditions, and operative details were evaluated as risk factors, with graft infection among the primary outcomes of interest. Results Prosthetic graft infection occurred in 25 of 141 (18%) infrainguinal grafts and occurred most frequently after major amputation (41% versus 6%; odds ratio [OR] = 12; 95% CI, 4.1 to 34) or early reoperation after initial grafting (70% versus 16%; OR=11; 95% CI, 1.9 to 63). Risk was highest after amputation within 4 weeks of bypass (70% versus 32%; OR=5.0; 95% CI, 1.1 to 23). Graft thrombosis (84% versus 39%; OR=8.3; 95% CI, 2.7 to 26) and presence of gangrene (52% versus 23%; OR=3.6; 95% CI, 1.5 to 8.7) also increased infection risk. Independent predictors for development of graft infection were identified by stepwise regression analysis to be amputation (p Conclusions Amputation increases risk of prosthetic graft infection, especially when performed early or after failed revascularization. Consideration should be given to partial or complete removal of a prosthetic graft above the level of the amputation under these conditions.

Inferior outcomes of autogenous infrainguinal bypass in Hispanics: An analysis of ethnicity, graft function, and limb salvage

Recent evidence suggests disparities exist among racial groups with peripheral arterial disease (PAD). Hispanics (HI) are the fastest growing demographic in the United States, but little outcome data is available for this population. Therefore, we undertook this study to compare the results of autogenous infrainguinal bypass grafting in HI to Caucasians (CA) and African Americans (AA). This was a comparative cohort study of prospectively collected registry data of infrainguinal bypass performed at a tertiary center. Patient demographics and comorbidities, operative indications, bypass graft characteristics, and postoperative courses were analyzed. Cumulative patency rates, limb salvage, mortality, and factors associated with these outcomes were determined using Kaplan-Meier analysis and Cox proportional hazards models. From January 1, 1985, through December 31, 2007, 1646 consecutive patients (1408 CA, 57 HI, and 181 AA) underwent 1646 autogenous infrainguinal reconstructions. HI and AA were younger and more often diabetic than CA but HI had less chronic renal insufficiency (CRI) and dialysis-dependence than AA. AA, but not HI, more commonly underwent bypass for critical limb ischemia (CLI) in comparison to CA (AA 90% vs CA 80%, P < .0001; HI 86%). HI and AA bypass grafts had inflow and outflow distal to that in CA. Perioperative mortality (2.3%) and morbidity were similar between groups. Five-year primary patency (+/- standard error [SE]) was significantly lower in HI compared to CA and similar to that in AA (HI 54% +/- 7% vs CA 69% +/- 1%, P = .02; AA 58% +/- 4%). Cox proportional hazard modeling showed high-risk conduit, age <65, CLI, female gender, and AA race were risk factors for failure of primary patency. Secondary patency of HI grafts, unlike AA, was not different than that in CA. Five-year limb salvage (+/- SE) was significantly lower in HI compared to CA and similar to that in AA (HI 80% +/- 6% vs CA 91% +/- 1%, P = .004; AA 83% +/- 3%). Hispanic ethnicity, CLI, high-risk conduit, age <65, CRI, female gender, and diabetes were significant predictors of limb loss. Autogenous infrainguinal bypass surgery in HI is associated with primary patency and limb salvage inferior to that of CA and similar to that of AA, despite HI rates of CLI equivalent to CA and HI comorbidities less severe than AA. HI ethnicity was an independent predictor of limb loss. Our data provides evidence of outcome disparities in HI treated aggressively for their PAD. Further investigation with regard to biologic and social factors is required to delineate the reasons for these inferior outcomes in HI patients.

Case Study: Chronic Femoropopliteal Prosthetic Graft Infection With Exposed Graft

One of the most feared complications following vascular reconstruction is infection due to the attendant risks of limb loss, sepsis, or death. The reported incidence of infection following infrainguinal prosthetic graft infection is 2.5% with associated mortality rates and amputation rates of 18% and 41%, respectively. There are several options in treating infected prosthetic infrainguinal bypass grafts. Some authors have advocated complete removal of the infected graft with concomitant in situ revascularization using autogenous tissue or extra-anatomic bypass using either autogenous or prosthetic material, depending upon the clinical circumstances. Other authors have advocated attempting graft preservation to decrease the risk of amputation. Infected, thrombosed grafts are generally treated with graft excision alone with care taken to preserve collateral flow. The treatment options may also be influenced by the type of infection, as infections caused by gram-negative bacteria are thought to be more virulent than those associated with gram-positive bacteria. We recently treated a patient with an 18-month history of an exposed prosthetic graft in the groin, which was infected by Proteus mirabilis. Despite the extended period of graft exposure and despite gram-negative bacteria being the causative organism, the patient reported only intermittent drainage of pus from the groin. The management of this unusual infection forms the basis of this report.