Tissue loss, early primary graft occlusion, female gender, and a prohibitive failure rate of secondary infrainguinal arterial reconstruction

Implantation of Adipose-Derived Mesenchymal Stromal Cells (ADSCs)-Lining Prosthetic Graft Promotes Vascular Regeneration in Monkeys and Pigs

BACKGROUND

Current replacement procedures for stenosis or occluded arteries using prosthetic grafts have serious limitations in clinical applications, particularly, endothelialization of the luminal surface is a long-standing unresolved problem.

METHOD

We produced a cell-based hybrid vascular graft using a bioink engulfing adipose-derived mesenchymal stromal cells (ADSCs) and a 3D bioprinting process lining the ADSCs on the luminal surface of GORE-Tex grafts. The hybrid graft was implanted as an interposition conduit to replace a 3-cm-long segment of the infrarenal abdominal aorta in Rhesus monkeys.

RESULTS

Complete endothelium layer and smooth muscle layer were fully developed within 21 days post-implantation, along with normalized collagen deposition and crosslinking in the regenerated vasculature in all monkeys. The regenerated blood vessels showed normal functionality for the longest observation of more than 1650 days. The same procedure was also conducted in miniature pigs for the interposition replacement of a 10-cm-long right iliac artery and showed the same long-term effective and safe outcome.

CONCLUSION

This cell-based vascular graft is ready to undergo clinical trials for human patients.

Modified Frailty Index Helps Predict Mortality and Ambulation Differences Between Genders and Racial Differences Following Major Lower Extremity Amputation

BACKGROUND

Major lower extremity amputation (LEA) is associated with significant morbidity and mortality. The modified frailty index (mFI-5) has been used to predict outcomes including ambulation and mortality after LEA. It remains unknown for which patient demographics the mFI-5 is a reliable predictor.

METHODS

This was a retrospective review of all patients who underwent a first-time major LEA at our institution from 2015 to 2022. Patients were stratified into 2 risk groups based on their mFI-5 score: non-frail (mFI<3) and frail (mFI≥3) and assessed on outcomes.

RESULTS

Our sample consisted of 687 patients of whom 134 (19.6%) were considered frail and 551 (80.4%) were considered non-frail. A higher mFI-5 is associated with decreased ambulation rates (OR: 0.565, P = .004), increased hospital readmission (OR: 1.657, P = .021), and increased mortality (OR: 2.101, P = .001) following major LEA. In African American patients, frail and non-frail patients differed on readmission at 90 days (P = .008), mortality at 1 year (P = .001), ambulatory status (P < .001), and prosthesis use (P = .023). In male patients, frail and non-frail patients differed on readmission at 90 days (P = .019), death at 1 year (P = .001), and ambulatory status (P = .002). In Caucasian patients and female patients, frail and non-frail patients did not differ significantly on outcomes.

DISCUSSION

The mFI-5 is a valuable predictor of outcomes following major LEA, specifically in males and African American patients. Moreover, surgeons should consider using frailty status to risk stratify patients and inform treatment plans.

Treatment of bypass failure in patients with chronic limb threatening ischemia – open surgery vs. percutaneous mechanical thrombectomy

Summary: Background: Lower limb bypass occlusion in patients with chronic limb threating ischemia remains a challenge. We can choose between different treatment options: open surgery, local thrombolysis, thrombectomy/atherectomy devices. In this pilot study, we compare clinical outcomes and treatment costs between open surgery (OS) and percutaneous mechanical thrombectomy (pMTH). Patients and methods: This pilot study represents a retrospective analysis of hospital data of 48 occluded bypasses admitted from 2013 to 2018. Only patients presenting with severe ischemia and recrudescence of symptoms (Rutherford 4–6) were included in the current analysis. Two cohorts of patients were analysed: patients who underwent OS and patients that underwent pMTH. Primary clinical outcomes were one-year cumulative patency and limb salvage rates. Total cost was calculated as a sum of intra- and post-operative costs. To weigh clinical benefits against the economic consequences of OS versus pMTH a cost-effectiveness framework was adopted. Results: We analysed a series of 48 occluded bypasses 17 treated with open surgery and 31 with pMTH. Procedural success was 100% in both groups. When comparing one-year death rates ( p-value = .22) and re-occlusion rates ( p-value = .43), no statistically significant differences were observed between the two cohorts. Mean patency duration in the surgery cohort was significantly shorter ( p-value < .05). Primary patency (OS 41.2% vs. pMTH 48.4%) and limb salvage rate (OS 88.2% vs. pMTH 90.3%) at one year are similar in both groups. The total cost of surgery was substantially higher (OS 10,159€ vs. pMTH 8,401€) Conclusions: This pilot study, although limited to 48 occluded bypasses, demonstrates that endovascular treatment with pMTH is less invasive, less time consuming and less expensive, and produces greater health benefits than traditional OS.

Bleeding and thrombotic outcomes associated with postoperative use of direct oral anticoagulants after open peripheral artery bypass procedures

OBJECTIVE

Widespread adoption of direct oral anticoagulants (DOACs) for atrial fibrillation and venous thromboembolism treatment has resulted in peripheral bypass patients receiving therapeutic anticoagulation with DOACs postoperatively. This study was undertaken to evaluate patient outcomes after open peripheral bypass based on anticoagulation treatment.

METHODS

Postoperative treatment and outcomes of patients undergoing peripheral bypass operations between January 2012 and December 2017 from a statewide multicenter quality improvement registry were examined. Surgeons participating in the registry were surveyed on practice patterns regarding DOACs in bypass patients. Multivariate logistic regression was performed for 30-day transfusion outcomes, and multiple linear regression was performed for length of stay.

RESULTS

Among 9682 patients, 7685 patients received no anticoagulation, whereas 1379 received a vitamin K antagonist (VKA) and 618 received a DOAC postoperatively. Patients receiving anticoagulation compared with no anticoagulation had a higher body mass index and were more likely to have preoperative anemia, congestive heart failure, and atrial fibrillation (all P < .001). Compared with patients receiving VKAs, patients receiving DOACs were less likely to have chronic kidney disease (P = .002) and more likely to have atrial fibrillation (P < .001). The shortest length of stay was among patients receiving no anticoagulation (median, 5 days; interquartile range, 3-9 days; P < .001), followed by DOACs (median, 6 days; interquartile range 3-11 days; P < .001) and VKAs (median, 8 days; interquartile range, 5-13 days; P < .001). Compared with patients receiving VKAs postoperatively, there was no difference in readmission for anticoagulation complications, bypass thrombectomy or thrombolysis, major amputation, or graft patency at 1 year among patients receiving DOACs. On multivariate logistic regression, patients receiving a DOAC (odds ratio, 0.743; confidence interval, 0.59-0.94; P = .011) or no anticoagulation (odds ratio, 0.792; confidence interval, 0.69-0.91; P = .001) were less likely to require transfusion within 30 days than patients taking VKAs. Approximately 70% of the surveyed surgeons reported that they "sometimes" or "always" use DOACs instead of VKAs for protection of a high-risk bypass.

CONCLUSIONS

Among patients undergoing lower extremity surgical bypass, those receiving a DOAC postoperatively had a shorter length of stay and were less likely to receive a transfusion in 30 days without compromising graft patency and readmission for anticoagulation complications, thrombectomy, or thrombolysis or affecting amputation rate compared with those receiving a VKA. A majority of surgeons within the quality collaborative have adopted the use of DOACs after peripheral bypass, suggesting the need for a prospective trial evaluating DOAC safety and efficacy in patients requiring anticoagulation for high-risk bypass grafts.

The Fate of Unrevised Stenoses in Infrainguinal Autologous Vein Grafts as Detected by Intraoperative Duplex Scanning

Intraoperative infrainguinal autologous vein graft stenoses are common, and some authors advise revision of these stenoses. But the natural history of these lesions is not clear. This study was undertaken to determine the natural history of duplex-detected intraoperative stenoses with a nonrevision policy. Intraoperative duplex scanning was performed in 46 infrainguinal autologous vein bypasses. The surgeon was blinded for the results of the intraoperative duplex scan and no intraoperative graft revision or modification of the routine postoperative protocol was performed after the duplex scan. Intraoperative duplex parameters and patient and bypass characteristics were correlated with the occurrence of an early graft event (occlusion or revision of a patent graft within 6 weeks postoperatively), which was the study's primary endpoint. Early graft event rate was 37% (17/46). PSV ratio and PSV-max were the only parameters with a significant correlation with the occurrence of an early graft event. An intraoperatively measured PSV ratio of =3.0 was the best predictor of an early graft failure with a sensitivity of 71% (95% CI: 50–83%) and a specificity of 90% (95% CI: 78–97%). In 12 of the 15 (80%) grafts matching this criterion an early graft event occurred, while only 5 (16%) early graft events occurred in the remaining 31 grafts (ie, a negative predictive value of 84%). When a PSV ratio of =3.0 was used as a cutoff value to predict early postoperative graft events, the likelihood ratios for a positive and negative test result were respectively 6.82 (95% CI: 2.23–20.8) and 0.33 (95% CI: 0.16–0.69). Unrevised intraoperative duplex-detected stenoses in infrainguinal autologous vein graft stenoses are a serious threat to early graft patency. The presence of an intraoperatively detected graft stenosis with a PSV ratio =3.0 is a strong predictor of early graft failure.

Contemporary outcomes with percutaneous vascular interventions for peripheral critical limb ischemia in those with and without poly-vascular disease

Given the very ill nature of patients with critical limb ischemia (CLI), the use of percutaneous vascular interventions (PVIs) for limb salvage may or may not be efficacious; in particular, for those with polyvascular arterial disease. Herein, we reviewed large, multi-institutional outcomes of PVI in polyvascular and peripheral arterial disease (PAD) patients with CLI. An 18-hospital consortium collected prospective data on patients undergoing endovascular interventions for PAD with 6-month follow-up from January 2008 to December 2011. The patient cohort included 4459 patients with CLI; of those, 3141 patients had polyvascular (coronary artery disease, cerebrovascular disease and PAD) disease, whereas 1318 patients suffered from only PAD. All patients were elderly and with significant comorbidities. The mean ankle–brachial index (ABI) was 0.44 and was not different between those with and without polyvascular disease. Polyvascular patients had more femoropopliteal and infra-inguinal interventions and less aortoiliac interventions than PAD patients. Pre- and post-procedural cardioprotective medication use was less in the PAD patients as compared with polyvascular patients. Vascular complications requiring surgery were higher in PAD patients whereas other access complications were similar between groups. At 6-month follow-up, death was more common in the polyvascular group (6.7% vs 4.1%, p<0.001) as was repeat PVI, but no difference was found in the amputation rate. Considering the group as a whole at the 6-month follow-up, predictors of amputation/death included age (HR=1.01; 95% CI=1.002–1.02), anemia (HR=2.6; 95% CI=2.1–3.2), diabetes mellitus (HR=1.6; 95% CI=1.3–1.9), congestive heart failure (HR=1.6; 95% CI=1.4–1.9), and end-stage renal failure (HR=1.9; 95% CI=1.5–2.3), while female sex was protective (HR=0.7; 95% CI=0.6–0.8). In conclusion, from examination of this large, multicenter, multi-specialist practice registry, patients with polyvascular disease had higher 6-month mortality than PAD patients, but this was not a factor in 6-month limb amputation outcomes. This study also underscores that PAD patients still lag in cardioprotective medication use as compared with polyvascular patients.

Endovascular recanalization of native chronic total occlusions in patients with failed lower-extremity bypass grafts

PURPOSE

To investigate the feasibility, safety, and outcome of endovascular recanalization of native chronic total occlusions (CTOs) in patients with failed lower-extremity bypass grafts.

MATERIALS AND METHODS

Retrospective review of 19 limbs in 18 patients with failed lower-extremity bypass grafts that underwent recanalization of native arterial occlusions between February 2009 and April 2013 was performed. Nine of the limbs presented with acute ischemia and 10 presented with chronic ischemia, including eight with critical limb ischemia and two with disabling claudication.

RESULTS

The mean patency of the failed bypass grafts (63% venous) was 27 months. All limbs had Transatlantic Inter-Society Consensus class D lesions involving the native circulation. Technical success of the endovascular recanalization procedure was achieved in all but one limb (95%). The mean ankle brachial indices before and after treatment were 0.34 and 0.73, respectively. There were no major complications or emergency amputations. Mean patient follow-up was 64 weeks, and two patients were lost to follow-up. Primary patency rates at 3, 6, and 12 months were 87%, 48%, and 16%, respectively. Successful secondary procedures were performed in seven patients, with secondary patency rates at 3, 6, and 12 months of 88%, 73%, and 44%, respectively. Limb salvage rates at 12 and 24 months were 94% and 65%, and amputation-free survival rates at 12 and 24 months were 87% and 60%, respectively.

CONCLUSIONS

Endovascular recanalization of native CTOs in patients with failed lower-extremity bypass grafts is technically feasible and safe and results in acceptable limb salvage.

Arterial vascular disease in women

BACKGROUND

Arterial disease in women will become a major issue in the near future.

METHODS

A systemic review of existing literature was retrospectively conducted to collect information on the three most common entities of vascular disease: carotid atherosclerotic, abdominal aortic aneurismal, and lower extremity arterial occlusive disease.

RESULTS

Vascular disease is either underdiagnosed or undertreated in women. Whether regarding cerebrovascular disease, aortic aneurysmal disease, or atherosclerosis affecting the lower extremities, natural history, clinical and physiologic patterns are different in women vs men. Current biomedical devices create challenges in endovascular procedures performed in women. Furthermore, indications for treatment of vascular disease are derived from large studies where women are often underrepresented; and, thus, may not be applicable in female vascular patients.

CONCLUSIONS

Better understanding of the gender differences in vascular disease with focused randomized trials, biomedical research, and identification of gender specific medical and social risk factors will improve the clinical outcomes in female patients.

A personal experience with the influence of diabetes and other factors on the outcome of infrainguinal bypass grafts for occlusive disease

OBJECTIVE

To investigate the influence of diabetes mellitus and other factors on the outcome of all infrainguinal bypass grafts performed for occlusive disease by a single surgeon at a tertiary referral center.

METHODS

The series includes 650 operations in 412 men and 238 women with median ages of 65 and 69 years, respectively. Critical ischemia was the indication for most procedures (n = 553, 85%), but 97 (15%) were done for claudication alone. Nearly half (n = 312, 48%) of the patients were diabetic, and 195 (30%) required insulin. All-autogenous vein was used for 389 grafts (60%). Synthetic or composite materials were employed for the remaining 261 grafts, 91 (35%) of which were entirely above the knee. Perioperative data were recorded contemporaneously and were supplemented by reviewing 558 of the 565 medical records and the Social Security Death Index. Survival, graft patency, and limb salvage were analyzed using logistic regression, Kaplan-Meier estimates and proportional hazards models.

RESULTS

Diabetics were more likely to have critical preoperative limb ischemia (P < .001), elevated serum creatinine (P = .003) or a history of previous coronary intervention (P = .015), lower extremity revascularization (P < .001) or minor amputations (P = .002). The operative mortality rate was 4.8%, and there were 81 graft occlusions (12%) and 49 major amputations (7.5%) during the index hospital admission. Patency was immediately restored in 46 of the 81 occluded grafts, but their secondary patency rates were only 62 +/- 16% at 1 year and 26 +/- 18% at 5 years. Insulin-dependent diabetes was associated with a higher incidence of early amputation (odds ratio, 2.6; 95% confidence interval [CI], 1.4-4.8; P = .004). Overall survival was 52 +/- 4% at 5 years and 25 +/- 5% at 10 years, and there were 175 late graft occlusions (27%), a total of 198 related reoperations and 107 late amputations (16%). The risks for further occlusion and/or major amputation after three or more graft revisions were 65% and 71%, respectively. Insulin-dependent diabetes also was associated with higher late mortality (hazard ratio [HR], 1.5; 95% CI, 1.2-1.8; P = .001) and amputation rates (HR, 1.5; 95% CI, 1.0-2.1; P = .026), but other independent variables like age, elevated serum creatinine, critical preoperative ischemia, synthetic conduits, and previous ipsilateral bypass had at least as much influence as diabetes on survival, graft failure or limb loss.

CONCLUSIONS

Diabetes was one of several factors influencing survival and limb preservation, but it did not adversely affect graft patency. The number of graft revisions was an important predictor of further occlusion or amputation.

Comparative analysis of autogenous infrainguinal bypass grafts in African Americans and Caucasians: The association of race with graft function and limb salvage

OBJECTIVE

African Americans (AAs) are at risk for developing diabetes mellitus and atherosclerosis. Whether race influences the results of infrainguinal arterial reconstruction is unclear. The purpose of this study was to compare the results of autogenous infrainguinal bypasses in AAs and Caucasians to determine the association of race with graft function and limb salvage.

METHODS

This was a retrospective, comparative cohort study of AA and Caucasian patients who had undergone autogenous infrainguinal bypass surgery. Only single-limb bypasses in each patient cohort were considered in this analysis. In patients who had undergone bilateral lower limb bypasses, the first limb bypass was chosen as the index bypass procedure.

RESULTS

From January 1985 to December 2003, 1459 autogenous infrainguinal bypasses were performed in 1459 patients for lower limb ischemia. Within this group, 89 AA patients/vein grafts formed the study cohort. The control group comprised 1370 Caucasian patients/vein grafts. Compared with the Caucasian cohort, AA patients were significantly younger (median age, 65 vs 70 years, respectively; P = .001) and predominantly female (57% vs 41%, respectively; P = .002). AA patients also had a higher prevalence of diabetes mellitus, hypertension, cerebrovascular disease, congestive heart failure, and dialysis-dependent renal failure. More AA than Caucasian patients presented with gangrene (34% vs 16%, respectively; P = .001), and more underwent bypass surgery for limb salvage indications (91% vs 81%, respectively; P = .01). The venous conduit used was predominantly the greater saphenous vein (AA, 83%; Caucasian, 85%), and the site of distal anastomosis was at the tibial/pedal level in 67% of AA and 61% of Caucasian patients. Overall morbidity (AA, 28%; Caucasian, 23%) and 30-day mortality (AA, 3%; Caucasian, 3%) were similar. Thirty-day graft failure was significantly greater in AAs than Caucasians (12% vs 5%, respectively; P = .003). The overall 5-year primary graft patency (+/-SE) was significantly worse in AA patients (AA, 52% +/- 6%; Caucasian, 67% +/- 2%; P = .009). The 5-year limb salvage rate (+/-SE) was also significantly worse in AA patients (AA, 81% +/- 5%; Caucasian, 90% +/- 1%; P = .04). With the Cox proportional hazard model, significant risk factors associated with primary graft failure were AA race, age younger than 65 years, female sex, secondary reconstructions, tibial bypasses, and critical limb ischemia. Significant risk factors associated with limb loss were age younger than 65 years, female sex, absence of coronary disease, presence of critical limb ischemia, and secondary reconstructions.

CONCLUSIONS

Autogenous infrainguinal bypass surgery in AAs is associated with poorer primary graft patency and limb salvage rates compared with those of Caucasians. This may partially account for the higher rate of limb loss in AA patients with peripheral arterial occlusive disease.

Improving quality of care in vascular surgery: the tools are available now

This overview delineates the current evidence and suggested practice protocols for three areas of vascular disease evaluation and treatment that have shown particular patient benefit. Presented as brief topical reviews are (1) preoperative cardiac evaluation and risk factor modification, (2) use of autologous tissue and graft surveillance for infrainguinal bypass, and (3) deep vein thrombosis risk stratification and prophylaxis. It is this author's hope is that this overview will emphasize currently effective and underused therapies and stimulate further research into best practices for improving the quality of care for vascular surgery patients.

Timing of Pedal Bypass Failure and Its Impact on the Need for Amputation

Although the utility of dorsalis pedis (DP) bypass for limb ischemia has been well established, the fate of limbs with a failed bypass to the DP artery remains unclear. Data of all patients undergoing DP bypass grafting within a 12-year period from two university hospitals' vascular registries were retrospectively reviewed. Outcomes of early (<30 days) and delayed graft failure (>30 days) were examined. The Student's t-test and chi-squared test were used for univariate analysis; patency rates and patient survival were calculated using the Kaplan-Meier product limit method. Of 1434 DP bypass grafts, 277 (19.3%) failed grafts were identified. Sixty five (4.5%) grafts failed early (within 30 days of surgery) and 212 (14.8%) failed late at a mean time of 15.3 months (range, 1.5-105 months) after initial bypass. Of the 65 limbs with early graft failure, 28 (43.1%) proceeded directly to amputation and 20 underwent additional revascularization attempts, but limb salvage was achieved in only 7 patients; in 45 (69.2%) patients no further revascularizations were attempted. Seventy-four (34.9%) patients with late graft failure underwent redo revascularization. Thirty-nine (52.6%) had their limb saved with graft revision, but 35 patients (47.3%) ultimately lost their limb. In 138 patients with late graft failure (65.1%) no further revascularization attempts were performed. Sixty-two (44.9%) required major amputation. Overall, 49.8% of patients with failed pedal grafts ultimately suffered limb loss. Early graft failure resulted in a significantly higher rate of major amputation that did late graft failure (63.1% vs. 45.8%, respectively; p = 0.015). These results indicate that early occlusion of pedal bypass often leads to immediate major amputation and interventions to maintain graft patency in this setting are often futile. Late failure of pedal bypass is associated with a lower likelihood of amputation because of a higher rate of success of bypass revisions and a lower occurrence of critical ischemia with graft failure.

Percutaneous Intentional Extraluminal Recanalization in Patients with Chronic Critical Limb Ischemia

PURPOSE

To review percutaneous intentional extraluminal recanalization (PIER) for treatment of patients who are poor candidates for infrainguinal arterial bypass surgery (IABS) and have arterial occlusions and chronic critical limb ischemia (CCLI).

MATERIALS AND METHODS

Patients with CCLI who were poor candidates for IABS were candidates for PIER. PIER was performed to create continuous arterial flow to the foot for limb salvage. PIER was attempted in 40 patients (22 men, 18 women; median age, 69 years; age range, 44-87 years). Of these patients, 24 (60%) had diabetes, 17 (42%) had renal disease, and 26 (66%) had coronary artery disease. Wound healing was evaluated at follow-up. Kaplan-Meier curves were constructed to evaluate limb salvage, survival, and amputation-free survival.

RESULTS

Fifty procedures were attempted in 44 limbs. Tissue loss was present in 40 (91%) limbs, and rest pain was present in four (9%); technical success occurred in 38 (86%). Thirty-seven (84%) of 44 limbs treated with PIER involved tibial vessels (tibial vessels only, n = 15; tibial and superior femoral artery [SFA] and/or popliteal vessels, n = 22). Sixty-six infrainguinal arterial vessel segments (SFA, n = 29; tibial, n = 37) in 38 limbs (1.7 segments per limb) were successfully treated with PIER. Thirty-five (95%) of 37 tibial occlusions and 24 (83%) of 29 SFA and/or popliteal occlusions were longer than 10 cm. Median run-off scores were 5.3 (range, 3-8) and 6.6 (range, 3-9) for patients with tibial occlusions and SFA and/or popliteal occlusions, respectively, as scored with modified Rutherford weighting of run-off arteries. Median follow-up was 7.8 months (range, 1-24 months). Twelve months after PIER, Kaplan-Meier analysis showed limb salvage rate was 66%, survival rate was 71%, and amputation-free survival rate was 48% in these patients. The 30-day mortality rate was 2.5%. Major complications occurred in four (10%) patients, and minor complications occurred in an additional four (10%).

CONCLUSION

PIER is a useful percutaneous technique for limb salvage in patients with CCLI.

Limb salvage after infrainguinal bypass graft failure

OBJECTIVE

The purpose of this study was to examine the outcome of patients in whom an infrainguinal bypass graft failed.

METHODS

This was a retrospective analysis of consecutive patients undergoing infrainguinal bypass grafting in a single institution over 8 years.

RESULTS

Six hundred thirty-one infrainguinal bypass grafts were placed in 578 limbs in 503 patients during the study period. The indication for surgery was limb-threatening ischemia in 533 patients (85%); nonautologous conduits were used in 259 patients (41%), and 144 (23%) were repeat operations. After a mean follow-up of 28 +/- 1 months (median, 23 months; range, 0-99 months), 167 grafts (26%) had failed secondarily. The rate of limb salvage in patients with graft failure was poor, only 50% +/- 5% at 2 years after failure. The 2-year limb salvage rate depended on the initial indication for bypass grafting: 100% in patients with claudication (n = 16), 55% +/- 8% in patients with rest pain (n = 49), and 34% +/- 6% in patients with tissue loss (n = 73; P <.001). The prospect for limb salvage also depended on the duration that the graft remained patent. Early graft failure (<30 days; n = 25) carried a poor prognosis, with 2-year limb salvage of only 25% +/- 10%; limb salvage was 53% +/- 5% after intermediate graft failure (<2 years, n = 110) and 79% +/- 10% after late failure (>2 years, n = 15; P =.04). Multivariate analysis revealed shorter patency interval before failure (P =.006), use of warfarin sodium (Coumadin) postoperatively (P =.006), and infrapopliteal distal anastomosis (P =.01) as significant predictors for ultimate limb loss.

CONCLUSION

The overall prognosis for limb salvage in patients with failed infrainguinal bypass grafts is poor, particularly in patients with grafts placed because of tissue loss and those with early graft failure.

Patients undergoing infrainguinal bypass to treat atherosclerotic vascular disease are underprescribed cardioprotective medications: effect on graft patency, limb salvage, and mortality

INTRODUCTION

Established American Heart Association guidelines recommend the use of statin drugs, angiotensin converting enzyme (ACE) inhibitors, and antiplatelet agents in patients with systemic atherosclerosis, such as those undergoing operative intervention to treat peripheral atherosclerotic disease. Many of these patients have not received treatment of coronary heart disease and have not been prescribed these medications. Whether statin drugs and ACE inhibitors confer an improvement in graft patency, limb salvage, and operative mortality is unknown.

METHODS

Consecutive patients who underwent infrainguinal bypass between 1997 and 2002 were evaluated for demographic data, comorbid disease, medication use, as well as cumulative graft patency, limb salvage, and mortality. Univariate, multivariate logistical regression, and Kaplan-Meier analyses were performed. P <.05 was considered significant.

RESULTS

Two hundred ninety-three patients (mean age, 64 years; 67% men) underwent 338 infrainguinal bypass procedures with autologous vein (n = 218), prosthetic grafts (n = 88), or composite prosthetic-vein grafts (n = 32). Limb salvage was the operative indication in 75% of procedures. Coexisting diseases included hypertension (70%), diabetes (52%), hyperlipidemia (37%), coronary heart disease (51%), congestive heart failure (14%), and active tobacco use (30%). Statin drugs were taken by 56% of patients, ACE inhibitors by 54% of patients, and antiplatelet agents or warfarin sodium (Coumadin) by 93% of patients. Postoperative graft surveillance was done in 39% of patients. Cumulative graft patency was 73%, limb salvage was 85%, and mortality was 9%, with a mean follow-up of 17 months. Factors independently associated with increased graft patency included statin drug use (odds ratio [OR], 3.7; 95% confidence interval [CI], 2.1-6.4), male sex (OR, 2.8; 95% CI, 1.6-5.0), and graft surveillance (OR, 2.4; 95% CI, 1.3-4.5). Factors associated with decreased amputation rate were statin drug use (OR, 0.34; 95% CI, 6.15-0.77) and graft surveillance (OR, 0.23; 95% CI, 6.1-0.63). Factors associated with decreased mortality included graft surveillance (OR, 0.18; 95% CI, 0.1-0.56), whereas congestive heart failure (OR, 6.5; 95% CI, 2.5-17) and hemodialysis-dependent renal failure (OR, 29; 95% CI, 6.1-140) were associated with increased mortality. Kaplan-Meier analysis showed that only ACE inhibitors were associated with lower mortality (P =.05)

CONCLUSIONS

Patients undergoing infrainguinal bypass are undertreated with respect to cardioprotective medications. ACE inhibitor use is associated with lower mortality, and statin drug use is associated with improved graft patency and limb salvage. Institution of consensus guidelines concerning these medications should be considered by all vascular specialists, including vascular surgeons.

Outcomes following distal bypass graft occlusion in diabetics

The objectives of this study were to define clinical outcomes following distal bypass graft occlusion in diabetic patients and identify factors predictive of limb loss. A retrospective review was conducted of all distal graft occlusions over a 5-year period in diabetic patients. Popliteal grafts, perioperative (30 days) failures, and redo distal bypasses were excluded. Eighty grafts were studied (43 cases done for ulcers, 31 for gangrene, and 6 for rest pain). Time to occlusion averaged 13 +/- 17 months post-bypass (median 6 months). Interventions following graft occlusion (lysis, thrombectomy, revision, or new bypass) were carried out in only 26 cases, leading to limb salvage in 11 cases (42%). This compares to a limb salvage rate of 54% in the 54 cases where no intervention was done ( p = NS). The overall amputation rate was 50% (14 AKAs and 26 BKAs). The interval between graft occlusion and amputation averaged 2 +/- 2 months. Limbs saved were followed an average of 14 +/- 11 months after graft occlusion. The presence of a foot wound (new or old) was associated with a higher likelihood of amputation (67% vs. 32% for cases with no foot wounds at the time of bypass failure; p < 0.005). In cases requiring an amputation, the toebrachial index averaged 0 +/- 0 post-bypass failure vs. 0.2 +/- 0.2 in cases where limbs were saved ( p < 0.05). Patients with congestive heart failure or who were nonambulatory at the time of graft occlusion were more likely to end up with an amputation ( p < 0.05). Limb loss was also more likely when gangrene had been the initial operative indication. No other factors were predictive of limb loss, including vein configuration, inflow or outflow level, prior bypass revision, known graft stenosis, time to occlusion, age, gender, other medical conditions, pre- or post-bypass ABI or TBI, graft velocities, or use of anticoagulants. Limb loss following primary distal bypass failure in diabetics is high. Repeat interventions have limited success. The findings justify aggressive programs of graft maintenance, and vigorous attempts at early closure of foot wounds.

Endovascular aneurysm repair: gender-specific results

OBJECTIVES

The outcome for a wide variety of diseases and treatment methods varies by gender. In an effort to determine whether gender has a role in the outcome of endovascular aortic aneurysm repair, we analyzed data from consecutive patients treated at a single institution over 6 years.

METHODS

Over 6 years ending in March 2002, 704 patients underwent endovascular repair of an infrarenal abdominal aortic aneurysm at The Cleveland Clinic. Six hundred six patients (86.1%) were men and 98 patients (13.9%) were women. Preprocedure and postprocedure imaging studies were evaluated to determine the frequency of aneurysm sac shrinkage or growth, defined as diameter change equal to or greater than 5 mm. Presence and type of endoleak was assessed with non-contrast material-enhanced, post-contrast-enhanced, and delayed post-contrast-enhanced computed tomography scans. These and other clinical variables were assessed with the Kaplan-Meier method and the Cox-Mantel log-rank test, and values were expressed as mean +/- SE.

RESULTS

Male and female patients were comparable with respect to baseline comorbid conditions. Women, however, were slightly older (76.7 +/- 0.7 years vs 74.4 +/- 0.3 years; P =.009), and had slightly smaller aneurysms (5.2 +/- 0.1 cm vs 5.4 +/- 0.04 cm; P =.033). There were no gender-specific differences in perioperative mortality (men, 1.3%; women, 3.1%; P =.197) or mid-term (24 months) survival (men, 80% +/- 2.6%; women, 78% +/- 8.1%). Similarly, there were no differences at 24 months in risk for graft migration (7.5% +/- 2.0% vs 5.4% +/- 3.2%), need for secondary remedial procedures (24% +/- 2.9% vs 21% +/- 6.3%), conversion to open surgery (3.9% +/- 1.5% vs 3.8% +/-2.7%), or post-repair aneurysm rupture (1.1% +/- 0.9% vs 2.2% +/-2.2%) in male and female patients, respectively. In contrast, risk for graft limb occlusion at 24 months was significantly higher in women than in men (11% +/- 5.2% vs 3.3% +/- 1.1%; P =.022). While frequency of endoleak of any type did not differ among male and female patients, aneurysm sac shrinkage at 24 months was more rapid in women (76% +/- 8.1% vs 57% +/- 3.5%; P =.019).

CONCLUSIONS

With the exception of slightly older age and somewhat smaller aneurysm, female patients are similar to male patients undergoing endovascular aneurysm repair. A greater frequency of graft limb occlusion was observed in female patients, but no statistically significant differences were detected in survival, rupture risk, or need for secondary procedures. Moreover, a more rapid rate of aneurysm sac shrinkage was detected in women. These observations suggest that endovascular aneurysm repair should be offered to suitable candidates irrespective of gender.