Long-term outcomes of infrainguinal bypass surgery for patients with diabetes mellitus and tissue loss

Risk score for nonhome discharge after lower extremity bypass

OBJECTIVE

Patients undergoing lower extremity bypass (LEB) for peripheral artery disease require intensive health care resource utilization including rehabilitation and skilled nursing facilities. However, few studies have evaluated factors that lead to nonhome discharge (NHD) in this population of patients. This study sought to predict NHD by preoperative risk factors in patients undergoing LEB for peripheral artery disease using a novel risk score.

METHODS

The Vascular Study Group of New England database was queried for elective LEB for peripheral artery disease including claudication and critical limb ischemia from 2003 to 2017. Patients were excluded if the procedure was not elective, if they were not admitted from home, if they were bedridden, or if they died during the index admission. Only preoperative factors were considered in the analysis. The primary end point was NHD including rehabilitation and skilled nursing facilities. Data were split two-thirds for model derivation and one-third for validation. In the derivation cohort, bivariate analysis assessed the association of preoperative factors with NHD. A parsimonious manual stepwise binary logistic regression for NHD aimed at maximizing the C statistic while maintaining model simplicity was performed. A risk score was developed using the β coefficients and applied to the validation data set. The risk score performance was assessed using a C statistic and Hosmer-Lemeshow test for model fit.

RESULTS

There were 10,145 cases included with an overall NHD rate of 26.4% (n = 2676). Mean age was 66 years (range, 41-90 years). NHD patients were older (72 years vs 64 years; P < .01) and more frequently male (57.2% vs 42.8%; P < .01) and nonwhite (16.1% vs 9.9%; P < .01); they more frequently had tissue loss (54.2% vs 23.0%; P < .01), anemia (16.0% vs 5.3%; P < .01), severe cardiac comorbidity (21.8% vs 10.5%; P < .01), and insulin-dependent diabetes (33.3% vs 18.2%; P < .01). On multivariable analysis, factors associated with NHD included age, sex, nonwhite race, tissue loss, cardiac comorbidity, partial ambulatory deficit, and insulin-dependent diabetes. The C statistic was 0.78 in the derivation group and 0.79 in the validation group, with Hosmer-Lemeshow P > .999. The risk score ranged from 0 to 18, with a mean score of 4 (standard deviation ±3.5). The risk score was divided into low risk (0-4 points; n = 5272 [52%]; NHD = 10.1%]), moderate risk (5-9 points; n = 3663 [36.7%]; NHD = 36.7%), and high risk (≥10 points; n = 1210 [11.9%]; NHD = 66.1%).

CONCLUSIONS

This novel risk score was highly predictive for NHD after LEB for peripheral artery disease using only preoperative comorbidities. High-risk patients account for 12% of LEB but nearly a third of all patients requiring NHD. This risk score can be used preoperatively to determine high-risk patients for NHD, which may help improve preoperative counseling and hospital efficiency by allocating resources appropriately.

Effects of topical Vancomycin Dressing on Methicillin-Resistant Staphylococcus Aureus (MRSA) positive diabetic foot ulcers

Objective:

To compare the effects of simple saline dressings versus topical vancomycin dressings on Methicillin-resistant Staphylococcus Aureus positive chronic diabetic foot ulcers.

Methods:

It was quasi experimental study conducted in Combined Military Hospital Kohat and PNS-Shifa Hospital Karachi from 01 January 2017 to 31 December 2017. A total of 23 patients were included based on non-probability convenient sampling who had diabetes and presented with foot ulcers for more than two weeks showing positive growth of Methicillin-Resistant Staphylococcus Aureus. The patients were treated with simple saline soaked dressings and debridement at first for three weeks followed by three weeks of topical vancomycin dressings with debridement. Thus patients served as their own controls

Results:

The average change in surface area with saline dressing was +1.73 ±1.53cm² per week whereas with vancomycin soaked dressing it was --0.06±1.60 cm² per week (p <0.05). The average exudate also decreased from 1.78±1.23 to 0.99±0.72 (p<0.05) and same trend was observed in percentage of slough covering the ulcer from 45% ± 22.3% to 24.3% ±12.90% (p<0.05) with vancomycin dressing. Moreover, fifteen patients had negative culture for MRSA within 2 weeks.

Conclusion:

Vancomycin impregnated dressing in MRSA positive Diabetic foot may help achieve early healing as compared to simple conventional dressings with no systemic toxicity.

Aggressive infrainguinal revascularization in renal transplant patients is justifiable

While studies demonstrate poor outcomes of lower extremity revascularization in patients with end-stage renal disease, little is known about results in renal transplant patients. We analyzed 2-year primary patency and limb salvage outcomes and associated risk factors of transplant (n = 202) and nontransplant patients (n = 25 274) in the Vascular Quality Initiative database undergoing infrainguinal bypass from 2003 to 2016. Multivariable Cox regression analysis and coarsened exact matching with many-to-one were used. Transplant patients were more likely to have critical limb ischemia and revascularization of more distal arteries and to receive vein conduits. Primary patency was similar between transplant and nontransplant patients at 1 year (80.8% vs 77.5%) and 2 years (67.9% vs 63.7%, P = .079). Amputation-free survival was higher for nontransplant patients (1 year: 82.4% vs 75.3%, 2 years: 68.8% vs 58.2%, P = .0060), although overall survival was equivalent (2 years: 84.6% vs 87.2%, 4 years: 75.9% vs 79.6%, P = .35). Risk factors for primary patency loss included being female, critical limb ischemia, prior bypass, and distal bypass. Age, diabetes, prior contralateral amputation, critical limb ischemia, prosthetic conduit, and more distal bypass were associated with limb loss. This is the largest series of infrainguinal revascularization in transplant patients. Outcomes for transplant patients are not inferior, and aggressive approaches at limb salvage are justifiable in appropriately selected patients.

Is the Endovascular Treatment of Mild Iliac Stenoses Worthwhile to Improve Wound Healing in Patients Undergoing Femorotibial Bypass?

BACKGROUND

After an infrapopliteal reconstruction, minor amputations are frequently required, but even in the case of successful revascularization, wound healing is a major concern. We studied the role of iliac artery inflow correction in patients undergoing infrapopliteal vein grafts to improve the heal of midfoot amputation.

METHODS

Thirty-eight patients affected with Rutherford grade III category 5 peripheral arterial disease, who underwent successful simultaneous iliac endovascular procedure, infrapopliteal reversed vein bypass graft, and minor amputation, were enrolled in this retrospective study. The population was divided in group 1 (20 patients) with inflow vessels Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease (TASC) II type B atherosclerotic lesions and group 2 (18 patients) with TASC II type A atherosclerotic lesions determining an invasive pressure drop greater than 15 mm Hg. Fifteen patients (group 3) undergoing infrapopliteal reversed vein bypass graft without associated inflow procedures (TASC II type A and invasive pressure drop greater than 15 mm Hg) were matched with group 2 based on propensity score. Healing was calculated by subtracting the final ulcer area from the initial ulcer area and dividing by the number of follow-up months to obtain the total area healed per month (cm²/month). Stepwise logistic regression analysis adjusted for demographics and medical comorbid conditions was used to test the association between wound healing and treatment modalities.

RESULTS

Forty-three patients were available for further analysis. Ten patients were excluded because of graft occlusion with consequent impairment of wound healing. After midfoot amputations, mean wound diameter was 20 ± 8 cm², and mean healing time was 10 ± 4 months (range 3-20 months; median 9 months). Wounds of groups 1 and 2 healed faster than those of group 3 at 4 and 8 months (P < 0.02 and P < 0.001, respectively; P < 0.04 and P < 0.001, respectively). Multivariate analysis demonstrated the association between wound healing and inflow correction (P < 0.001).

CONCLUSIONS

An aggressive treatment is necessary to obtain the heal of the ischemic wounds. The most important predictive factor for nonhealing wounds is the absence of inflow correction. We demonstrated that the inflow should be also corrected in the presence of subclinical lesions.

A comparison of tibial and peroneal venous and HePTFE bypasses in diabetics with critical limb ischemia

OBJECTIVE

In this study we analyzed the outcome of tibial and peroneal venous and heparin-bonded expanded polytetrafluoroethylene (HePTFE) bypasses in diabetics with critical limb ischemia (CLI). We aimed to verify our hypothesis that HePTFE grafts will achieve acceptable 1-year patency and limb salvage results in patients who lack an adequate vein.

METHODS

We conducted a retrospective analysis for all diabetics who underwent tibial bypass surgery in our department between October 2007 and October 2012. The study includes 97 grafts. All these patients were not suited for an endovascular therapy. We used autologous veins in 56 cases (Vein-Group) and HePTFE grafts in 41 cases (HePTFE-Group). Study endpoints were primary and secondary patency, limb salvage, and survival at 2 years postoperatively.

RESULTS

Risk factors and indications were similar in both groups. The comparison between HePTFE- and Vein-Group showed significantly different patency rates. At 2 years, primary patency was 39.3% in HePTFE-Group vs. 78.5% in Vein-Group (P = .003) and secondary patency was 47.4% vs. 81.9% (P = .002). Limb salvage at 2 years was 79.3% vs. 87.4% (P = .073) and survival was 64.6% vs. 62.9% (P = .593) at the 2-year mark, with no significant differences. 30-days mortality, graft occlusion and major amputation rate showed no significant differences, either.

CONCLUSIONS

This study shows that HePTFE bypasses are a viable option for diabetics undergoing tibial bypass surgery when no adequate vein is available.