The effect of arterial reconstruction on the natural history of diabetic neuropathy.

Abstract

To determine whether reversal of hypoxia slows the progression of neuropathy. Cohort study with a mean follow-up of 19.2 months. Institutional and private hospital. A volunteer sample of 55 patients with diabetes (mean age, 62 years; range, 30-74 years; mean duration of diabetes, 21 years; range, 1-57 years) requiring lower-extremity arterial bypass. Twenty-one successfully treated patients were reexamined at the conclusion of the study. Neuropathy and hypoxia were assessed the day before the operation and during the follow-up visit. Lower-extremity arterial reconstruction. Peroneal nerve conduction velocity and transcutaneous oxygen tension. In the leg operated on, the peroneal nerve conduction velocity remained unchanged during the follow-up period (preoperative, mean [+/- SD] 35.79 +/- 6.02 vs postoperative 35.33 +/- 7.51 m/s; P > .05), but deteriorated in the leg not operated on (36.68 +/- 6.22 vs 33.64 +/- 7.30 m/s; P < .05, Wilcoxon signed rank test). Transcutaneous oxygen tension increased in the revascularized extremity (mean [+/- SD] 40.62 +/- 24.76 vs 66.73 +/- 14.89 mm Hg) but remained unchanged in the leg not operated on (56.76 +/- 17.07 vs 62.00 +/- 15.66 mm Hg; P > .05). Of the entire cohort, 5 patients died during the study period. Graft occlusion occurred in 10 (17%) of 59 extremities. Subset analysis disclosed that the preoperative transcutaneous oxygen tension was significantly higher in the successfully revascularized extremities (41.98 +/- 23.58 vs 24.10 +/- 21.50 mm Hg; P < .001). Reversal of hypoxia halts the progression of diabetic neuropathy, lending further support to the role of hypoxia in the pathogenesis of nerve destruction in diabetes mellitus. Preoperative transcutaneous oxygen tension is lower in patients with bypass failure, but the severity of neuropathy does not affect the outcome of the operation.