The relative roles of aggressive wound care versus revascularization in salvage of the threatened lower extremity in the renal failure diabetic patient

Current literature indicates poor survival and limb salvage rates in renal failure diabetic patients who present with ulcerated or gangrenous lower extremities. Even in those limbs that were successfully revascularized, the amputation rate was as high as 37 percent. This has led some to advocate immediate amputation when treating the threatened limb of a renal failure diabetic patient. The authors reviewed all renal failure diabetic patients in their wound registry, to determine whether such pessimism was warranted. The authors then analyzed the relative roles of revascularization and aggressive wound care on long-term limb salvage. Forty-five consecutive renal failure diabetic patients with 71 wounds in 54 limbs were identified. Twenty-seven patients had chronic renal insufficiency, 15 patients had end-stage renal disease, and three patients received kidney transplants. The revascularization procedures (46 percent of all limbs) included angioplasty, femoral-popliteal, femoral-distal, and popliteal-distal bypasses. Forty-three amputations in combination with 67 soft-tissue repairs (delayed primary wound closure, skin grafts, local flaps, pedicled flaps, and free flaps) were necessary to close the defects. After a mean follow-up of over 3 years, the data indicate that 79 percent of wounds healed, 89 percent of all limbs were salvaged, and 49 percent of patients survived. Revascularization improved the threatened limb's salvage rate from negligible to a level similar to that of the adequately vascularized limb. Fifteen out of 71 wounds did not heal because of the patient's early postoperative death, ischemia not amenable to revascularization, or noncompliance. Six below-knee amputations were performed (one despite a patent bypass and five in adequately vascularized patients). The average time for wounds to heal in the revascularized patients was 79 days versus 71 days in adequately vascularized patients. There was an overall 43 percent complication rate. Of the patients who were alive after the 3-year follow-up, 73 percent were independently ambulating, whereas 27 percent were bound to wheelchair or bed. Eighty-two percent of patients were very satisfied with the salvage attempt, 18 percent were moderately satisfied, and all patients said they would go through the process again. The authors believe that salvaging the threatened extremity in the renal failure diabetic patient is justified whether or not the limb requires revascularization. Revascularization improved the limb salvage rate, patient survival, and days for wounds to heal to a level comparable to that of the adequately vascularized limb. The key to subsequently achieving high salvage rates is the quality of perioperative wound care (e.g., serial debridements, antibiotics, dressings) and the timing and selection of appropriate soft-tissue coverage.