Etiology of late free flap failures occurring after hospital discharge

OBJECTIVES: Vascular compromise of free flaps most commonly occurs in the immediate postoperative period in association with failure of the microvascular anastomosis. Rarely do flaps fail in the late postoperative period. It is not well understood why free flaps can fail after 7 postoperative days. We undertook a case review series to assess possible causes of late free flap failure. STUDY DESIGN: Retrospective review at two tertiary referral centers: Oregon Health Sciences University and University of Alabama at Birmingham. METHODS: A review of 1,530 flaps performed in 1,592 patients between 1998 and 2006 were evaluated to identify late flap failure. Late flap failure was defined as failure occurring after postoperative day 7 or on follow-up visits after hospital discharge. A prospective database with the following variables was examined: age, medical comorbidities, postreconstructive complications (fistula or infection), hematoma, seroma, previous surgery, radiation therapy, intraoperative findings at the time of debridement, nutrition, and, possibly, etiologies. RESULTS: A total of 13 patients with late graft failure were identified in this study population of 1,530 (less than 1%) flaps; 6 radial forearm fasciocutaneous flaps, 2 rectus abdominis myocutaneous flaps, 4 fibular flaps, and 1 latissimus dorsi myocutaneous flap underwent late failure. The time to necrosis was a median of 21 (range, 7-90) days. Etiology was believed to possibly be pressure on the pedicle in the postoperative period in four patients (no sign of local wound issues at the pedicle), infection (abscess formation) in three patients, and regrowth of residual tumor in six patients. Loss occurring within 1 month was more common in radial forearm flaps and was presented in the context of a normal appearing wound at the anastomotic site, as opposed to loss occurring after 1 month, which happened more commonly in fibula flaps secondary to recurrence. CONCLUSION: Although late free flap failure is rare, local factors such as infection and possibly pressure on the pedicle can be contributing factors. Patients presenting with late flap failure should be evaluated for residual tumor growth.