Evidence-Based Approach to Free Tissue Transfer In the Obese Patient—Analysis of 1,258 Abdominally-Based Reconstructions

Purpose

Obesity is a growing epidemic in the United States (US) with an incidence exceeding 1/3 of all US adults.  Our institution has seen a concomitant increase in obese and morbidly obese patients seeking autologous breast reconstruction.  We aim to provide a comprehensive outcome analysis of patients undergoing abdominally-based autologous breast reconstruction using the World Heath Organization (WHO) obesity classification. 

 

Methods

We reviewed our prospectively maintained database identifying obese patients receiving free tissue transfer for breast reconstruction.  Patients were classified by WHO obesity criteria: non-obese (BMI=20-29.9 kg/m²), Class I (BMI=30-34.9 kg/m²), Class II (BMI=35-39.9 kg/m²), and Class III (BMI>40 kg/m²).  Intraoperative and postoperative complications (medical and surgical) and hospital resource utilization were compared across groups. All tests were two-tailed and statistical significance was defined as p<0.05.  

 

Results

812 patients undergoing 1258 free tissue transfers for breast reconstruction were included.  Free flaps included: msTRAM (71.1 percent), DIEP (23.1 percent), and SIEA (5.8 percent).  Overall, 66.5 percent (n=540) were considered non-obese, 20.9 percent (n=170) were defined as Class I obesity, 6.9 percent (n=56) were Class II, and 5.7 percent (n=46) were Class III.  Obesity was associated with a significant increase in minor (p=0.001) and major (p<0.001) complications.  Morbidly obese patients had significantly higher rates of total flap loss (p=0.006), as well as longer operative times (p<0.0001) and greater intraoperative blood loss (p=0.02).  

Complications in the obese cohort translated into greater cost and resource consumption (p<0.001).  Obese patients receiving a msTRAM experienced a significantly higher rate of hernia compared to DIEP and SIEA flaps (8.6 percent vs. 1.1 percent vs. 0 percent, p=0.02) without a difference in flap loss rate (1.9 percent vs. 3.6 percent vs. 0 percent, p=0.61).  Overall, utilization of an SIEA flap in patients with a BMI >30 kg/m² was associated with significantly less hospital-associated cost ($18,868 (SIEA) vs. $20,463 (DIEP) vs. $20,825 (msTRAM), p=0.04).

 

Conclusion

Obesity is associated with significant risk morbidity in free abdominally-based autologous breast reconstruction translating into greater perioperative morbidity, higher hospital cost, and increased resource consumption.  BMI appears to be directly related to intraoperative technical difficulty, flap loss, donor site morbidity, and cost utilization.  If an SIEA or DIEP flap can be utilized in an obese patient, then there is decreased abdominal morbidity without added risk of flap loss.