Multivariate predictors of failure after flap coverage of pressure ulcers

Pressure ulcers are estimated to be present in more than one-third of patients with spinal cord injury. The rate of recurrence after flap surgery over last 50 years has ranged between 3 and 82 percent, with no trend toward improvement. This study seeks to identify and evaluate patient and operative characteristics associated with flap dehiscence and ulcer recurrence.

A retrospective chart review of all patients who underwent pressure ulcer flap coverage between 1993 and 2008 was performed. Thirty-one demographic and operative variables were collected. Multivariate logistic regression with generalized estimating equation was used to evaluate the effect of significant variables. The primary outcome was recurrence of pressure ulcer at the operative site. Secondary outcomes included flap line dehiscence and the need for operative revision.

There were 88 recurrences of pressure ulcers after flap surgery (39 percent) of 227 operations performed on 135 patients. Thirty-six flaps (16 percent) had dehiscences necessitating return to the operating room. Hemoglobin A1c less than 6 percent and previous same-site flap failure were associated with both dehiscence and recurrence (odds ratios, 2.15 and 3.84; and odds ratios, 6.51 and 3.27). Younger age and albumin less than 3.5 were associated with early flap failure (odds ratios, 5.95 and 2.45). Ischial wound location correlated with late recurrence (odds ratio, 4.01). Patients with multiple risk factors had operative success rates that approached zero.

Confirmation of adequate nutritional status and strict preoperative management of blood glucose may improve operative success rates. The authors propose that operative management should be approached with trepidation, if at all, in young patients with recurrent ischial ulcers.