Is Limb Salvage Practical In Patients With Diabetes And Renal Failure?
Understanding The Risk Factors In The Diabetic Population
One common diabetic foot risk classification system places individuals into five different categories: normal, high risk, ulcerated, infected and the most critical stage, necrotic.9 Several studies have reported that 70 to 86 percent of amputations in patients with diabetes were preceded by ulceration.12 Labeled as a “pivotal event” in diabetic foot care, ulceration is a concerning milestone in the degeneration of a healthy limb.13 Callus and neuropathy are two serious factors that can lead to ulceration. Education about footwear and control of blood glucose, lipids and blood pressure are crucial ingredients in fighting diabetic foot disease.2,14 Once the diabetic foot progresses to the ulceration stage, it can be difficult to avoid infection. Unlike those with renal failure, patients suffering from diabetes alone often exhibit positive results after undergoing revascularization, even when infection or tissue loss complicates the case.15 However, patients suffering from both diabetes mellitus and ESRD have low survival rates after revascularization (65 percent after one year and 45 percent after two years).4 Nevertheless, when the patient can maintain arterial sufficiency, an aggressive treatment plan should involve timely and frequent debridements to sustain viable tissue in order for foot ulcers to heal. One study confirms that the longer debridement is delayed, the further up the leg amputation will occur.16 As a result of medical complications in the patient with diabetes and renal failure, the risk of amputation increases with the degree of ulceration and the extent of arterial disease.
A Closer Look At Revascularization And Amputation In Patients With Diabetes And ESRD
As diabetes and renal failure both significantly impede recovery of a diseased foot, many providers support primary amputation for these patients. It is no secret that the combination of these conditions greatly complicates limb salvage. One study found: “The chronic renal failure patient with diabetes has a lower limb amputation rate 10 times greater than the diabetic population at large.”17 The literature clearly suggests that the implications of ESRD are more dire than those of diabetes mellitus when it comes to the life expectancy and amputation status of these patients. In support of this assertion, one study of ESRD patients reports that no differences were found between patients with diabetes and those patients without diabetes in regard to “ … the number of revascularization operations performed, the level of major amputation or overall survival.”18 Some specialists argue that limb salvage rates are too dismal to avoid primary amputation in patients with ESRD.8 One study affirms that 75.9 percent of major lower extremity amputations are the cause of critical ischemia, the main consequence of renal failure, while only 17.2 percent were caused by diabetic infection.2 Physicians argue that the failure to heal trumps arterial sufficiency in decisions to amputate in this population.19 Accordingly, some maintain that primary amputation is necessary for the patient with ESRD regardless of whether a patent bypass is achieved.9 As a result, the amputation rate has been as high as 37 percent even after vascular surgeons have achieved revascularization.20 Many physicians argue that the presence of gangrene (especially in the midfoot) and extensive infection are indications that warrant primary amputation.1,6,18,19 Nevertheless, if revascularization is performed as early as ischemic disease is detected, the literature predicts better results for the patient with ESRD.18,19