Blood loss and transfusion rates in DIEP flap breast reconstruction. Introducing a new predictor.

Background: The popularity of the DIEP flap has increased over the last decade. However, there is little information regarding the transfusion rates of this complex procedure. The current study reports the transfusion rates in patients who underwent DIEP flap reconstruction in our unit with an attempt to correlate significant blood loss with potential predictors such as the abdominal flap weight.

Methods-material: A retrospective review of 131 patients who underwent DIEP reconstruction was performed. Patients' characteristics, risk factors, incidence of blood transfusions, Hb drop and complications were reviewed. For statistical analysis the two-tailed Student t-test, chi-squared significance test and multiple regression model were used.

Results: 12 patients (9.1%) were transfused compared to 80.3% and 18.8% described in the literature. Definite association was found between the presence of a complication and transfusion. No correlation was found between age, obesity, chemotherapy and/or radiotherapy or tamoxifen treatment and blood loss. However, operation duration, complications and weight all found to have significant correlation. On average, every additional hour of surgery adds 0.25 g of Hb drop; the presence of a complication adds 0.45 g of Hb drop, and every extra gram of tissue removed from the abdomen adds an extra 0.001 g of Hb drop.

Conclusion: The different transfusion rates published reflect variations in surgical strategies, different operative technical details but mostly transfusion protocols applied in each unit. As a correlation with complications was found, it is quite important to identify predictors for significant blood loss to optimise the operation outcome which in our study are additional time of surgery, the presence of complication and increased flap weight.