In this prospective, randomized, placebo-controlled clinical trial, ex vivo treatment of lower extremity vein grafts with edifoligide did not confer protection from reintervention for graft failure.

Autologous saphenous vein (ASV) and polytetrafluoroethylene (PTFE) grafts were compared in 845 infrainguinal bypass operations, 485 to the popliteal artery and 360 to infrapopliteal arteries. Life-table primary patency rates for randomized PTFE grafts to the popliteal artery paralleled those for randomized ASV grafts to the same level for 2 years and then became significantly different (4-year patency rate of 68% +/- 8% [SE] for ASV vs. 47% +/- 9% for PTFE, p less than 0.025). Four-year patency differences for randomized above-knee grafts were not statistically significant (61% +/- 12% for ASV vs. 38% +/- 13% for PTFE, p greater than 0.25) but were for randomized below-knee grafts (76% +/- 9% for ASV vs. 54% +/- 11% for PTFE, p less than 0.05). Four-year limb salvage rates after bypasses to the popliteal artery to control critical ischemia did not differ for the two types of randomized grafts (75% +/- 10% for ASV vs. 70% +/- 10% for PTFE, p greater than 0.25). Although primary patency rates for randomized and obligatory PTFE grafts to the popliteal artery were significantly different (p less than 0.025), 4-year limb salvage rates were not (70% +/- 10% vs. 68% +/- 20%, p greater than 0.25). Primary patency rates at 4 years for infrapopliteal bypasses with randomized ASV were significantly better than those with randomized PTFE (49% +/- 10% vs. 12% +/- 7%, p less than 0.001). Limb salvage rates at 3 1/2 years for infrapopliteal bypasses with both randomized grafts (57% +/- 10% for ASV and 61% +/- 10% for PTFE) were better than those for obligatory infrapopliteal PTFE grafts (38% +/- 11%, p less than 0.01). These results fail to support the routine preferential use of PTFE grafts for either femoropopliteal or more distal bypasses. However, this graft may be used preferentially in selected poor-risk patients for femoropopliteal bypasses, particularly those that do not cross the knee. Although every effort should be made to use ASV for infrapopliteal bypasses, a PTFE distal bypass is a better option than a primary major amputation.

Patients with critical limb ischemia (CLI) are a heterogeneous population with respect to risk for mortality and limb loss, complicating clinical decision-making. Endovascular options, as compared to bypass, offer a tradeoff between reduced procedural risk and inferior durability. Risk stratified data predictive of amputation-free survival (AFS) may improve clinical decision making and allow for better assessment of new technology in the CLI population. METHODS This was a retrospective analysis of prospectively collected data from patients who underwent infrainguinal vein bypass surgery for CLI. Two datasets were used: the PREVENT III randomized trial (n=1404) and a multicenter registry (n=716) from 3 distinct vascular centers (2 academic, 1 community-based). The PREVENT III cohort was randomly assigned to a derivation set (n=953) and to a validation set (n=451). The primary endpoint was AFS. Predictors of AFS identified on univariate screen (inclusion threshold, p<0.20) were included in a stepwise selection Cox model. The resulting 5 significant predictors were assigned an integer score to stratify patients into 3 risk groups. The prediction rule was internally validated in the PREVENT III validation set and externally validated in the multicenter cohort. RESULTS The estimated 1 year AFS in the derivation, internal validation, and external validation sets were 76.3%, 72.5%, and 77.0%, respectively. In the derivation set, dialysis (HR 2.81, p<.0001), tissue loss (HR 2.22, p=.0004), age ≥75 (HR 1.64, p=.001), hematocrit ≤30 (HR 1.61, p=.012), and advanced CAD (HR 1.41, p=.021) were significant predictors for AFS in the multivariable model. An integer score, derived from the β coefficients, was used to generate 3 risk categories (low ≤ 3 [44.4% of cohort], medium 4–7 [46.7% of cohort], high ≥8 [8.8% of cohort]). Stratification of the patients, in each dataset, according to risk category yielded 3 significantly different Kaplan-Meier estimates for one year AFS (86%, 73%, and 45% for low, medium, and high risk groups respectively). For a given risk category, the AFS estimate was consistent between the derivation and validation sets. CONCLUSION Among patients selected to undergo surgical bypass for infrainguinal disease, this parsimonious risk stratification model reliably identified a category of CLI patients with a >50% chance of death or major amputation at 1 year. Calculation of a “PIII risk score” may be useful for surgical decision making and for clinical trial designs in the CLI population.

Autologous saphenous vein (ASV) and polytetrafluoroethylene (PTFE) grafts were compared in 845 infrainguinal bypass operations, 485 to the popfiteal artery and 360 to infrapopliteal arteries. Life-table primarypatency rates for randomized PTFE grafts to the popliteal artery paralleled those for randomized ASV grafts to the same level for 2 years and then became significantly different (4-year patency rate of 68%-8% [SE] for ASV vs. 47%-9% for PTFE, p < 0.025). Four-year patency differences for randomized above-knee grafts were not statistically significant (61%-+ 12% for ASVvs. 38%-13% for PTFE, p > 0.25) but were for randomized below-knee grafts (76%-+ 9% for ASV vs. 54% + 11% for PTFE, p < 0.05). Four-year limb salvage rates after bypasses to the popliteal artery to control critical ischemia did not differ for the two types of randomized grafts (75%-10% for ASV vs. 70%-10% for PTFE, p > 0.25). Although primary patency rates for randomized and obligatory PTFE grafts to the popliteal artery were significantly different (p < 0.025), 4-year limb salvage rates were not (70%-+ 10% vs. 68%-20%, p > 0.25). Primary patency rates at 4 years for infrapopliteal bypasses with randomized ASV were significantly better than those with randomized PTFE (49%-+ 10% vs. 12% + 7%, p < 0.001). Limb salvage rates at 3V2 years for infrapopliteal bypasses with both randomized grafts (57%-+ 10% for ASV and 61%-+ 10% for PTFE) were better than those for obligatory infrapopliteal PTFE grafts (38%-11%, p < 0.01). These results fail to support the routine preferential use of PTFE grafts for either femoropopliteal or more distal bypasses. However, this graft may be used preferentially in selected poor-risk patients for femoropopliteal bypasses, particularly those that do not cross the knee. Although every effort should be made to use ASV for infrapopliteal bypasse,~, a PTFE distal bypass is a better option than a primary major amputation.

During the past 15 years, we have employed a modified classification and management plan to treat infections involving nonaortic peripheral arterial prosthetic grafts (PAPGs) without graft removal whenever possible. Sixty-eight infected wounds potentially involving PAPGs were initially treated by excision of necrotic and infected wound tissue in the operating room (wound excision). This was sufficient for all 34 minor infections that did not directly involve the graft. In the 34 remaining infected wounds with graft involvement (major infections), partial removal of a PAPG in 13 cases allowed preservation for up to 15 years of a functioning arterial segment and its collaterals. Ten other grafts were entirely saved. Only 11 of 34 major graft infections ultimately required total graft removal. This approach to infection complicating PAPGs resulted in only two deaths (6%) and directly led to limb loss or amputation at a higher level in eight patients (24%). Total removal of an infected PAPG is often unnecessary and may increase mortality and morbidity.