Abstract
OBJECTIVE
1) Evaluate key clinical parameters in patients undergoing microvascular free flap reconstructions. 2) Identify clinical factors that may be related to free flap complications and failures.
METHOD
Retrospective analysis was performed on 600 patient medical records of all patients undergoing free microvascular tissue transfers at The Johns Hopkins Hospital from 1998 to 2008. Indications for surgery included surgical defects related to oncologic resection, benign tumors, trauma, non-healing wounds, hernia repairs, and congenital anomalies. Clinical parameters studied included patient demographics, past medical history, comorbidities, medication history, intra-operative surgical case characteristics, free flap monitoring techniques, postoperative course, complications leading to surgical re-exploration, and flap salvage rate. Univariate and multivariate statistical analysis and modeling was performed on clinical parameters to assess their potential contribution to free flap complications and outcomes.
RESULTS
Pressors, anticoagulants, blood transfusions, advanced age, smoking, diabetes, and peripheral vascular disease did not appear to be associated with an increase in flap complications or failures. The flap monitoring method or duration of monitoring did not affect free flap outcomes. The number of free flap complications, re-explorations and intra-operative fluid balance showed statistical significance with regards to overall flap failures. Prolonged postoperative intubation time showed a small trend towards significance. The overall complication rate was greater than 10% and failure rate was less than 5% as defined by a non-viable flap.
CONCLUSION
Microvascular free flaps are robust and have a relatively low surgical failure rate. Fluid balance has to be closely monitored in the intra and peri-operative time period, and fluid excess should be minimized. The number of complications and re-explorations should be limited to avoid free flap failure.