Reoperation of Lower Extremity Microsurgical Reconstruction When Facing Postsplenectomy Thrombocytosis

Reevaluating Thrombocytosis as a Risk Factor in Free Flap Surgery: Does Timing Matter?

INTRODUCTION

Thrombocytosis, defined as a platelet count >400,000, has been implicated as a risk factor in free flap failure. Despite proposed mechanisms of pedicle thrombosis, recent studies have suggested that thrombocytosis has no effect on free tissue transfer viability. Risk factors that may compromise successful free tissue transfer should be understood and elucidated, with particular attention to thrombocytosis and its conflicting evidence in the literature. We hypothesize that thrombocytosis has no bearing on free flap success or the rates of pedicle thrombosis.

METHODS

Our institution performed a retrospective chart review on all patients who underwent free flap reconstruction over the past 6 years. Patient demographics, medical history, type and location of free tissue transfer, preoperative platelets, postoperative platelets, and flap outcomes and complications (wound dehiscence, infection, hematoma, seroma, and need for blood transfusion) were recorded. Independent t test, Mann-Whitney U tests, χ2 test, and Fisher exact tests were used to determine P values to compare flap outcomes in patients with thrombocytosis (platelet count >400,000) and those with platelet counts less than 400,000.

RESULTS

In our 502-patient cohort, 71 were found to have a platelet count >400,000 (35 preoperatively and 36 postoperatively) and 431 patients had platelet counts <400,000. There were 42 reconstructive failures (flap success rate of 91.6%) and 111 returns to the operating room (OR). For patients with postoperative thrombocytosis, 24 flaps returned to the OR (44.4%), whereas in patients without thrombocytosis, 87 flaps returned to the OR (19.4%; P < 0.001). In patients with postoperative thrombocytosis, 10 OR returns were due to pedicle venous thrombosis (18.5%), in comparison to 10 returns for venous thrombosis in those with normal platelets (2.2%; P < 0.001). There was a small difference in free flap success rates between those with postoperative thrombocytosis and normal platelets, 88.7% versus 92.11%; however, this was not statistically significant ( P = 0.71). The thrombocytosis group had a higher incidence of overall postoperative complications ( P = 0.002).

CONCLUSIONS

Thrombocytosis has historically been cited as a risk factor for free flap reconstruction failure with recent conflicting evidence in the literature. In patients with postoperative thrombocytosis, we found an increased risk of venous thrombosis; however, this did not result in increased flap failure. There was an increase in postoperative complications, which corresponds with National Surgical Quality Improvement Program data reported in the literature. We suspect that thrombocytosis is not a harbinger of free flap failure but rather a marker for overall inflammation, which may confer a higher rate of venous thrombosis requiring reoperation and postoperative complications.

Free Flaps in Lower Extremity Reconstruction

Free tissue transfer to the lower extremity for limb salvage remains challenging. A comprehensive approach includes patient selection, flap selection, selection of the recipient vessels, flap dissection, flap preparation, microvascular anastomosis, flap inset, immediate postoperative care, intermediate postoperative care, and further follow-up care. Each step in this comprehensive approach has its unique considerations and should be executed equally to ensure an optimal outcome. Once acquired, some clinical experience along with adequate microsurgical skill, good surgical judgment, well instructed and step-by-step intraoperative execution, and a protocol-driven practice, successful free tissue transfer to the lower extremity can be accomplished.