Effect of obesity on flap and donor-site complications in free transverse rectus abdominis myocutaneous flap breast reconstruction

The purpose of this study was to assess the effect of obesity on flap and d onor-site complications in patients undergoing free transverse rectus abdom inis myocutaneous (TRAM) flap breast reconstruction. All patients under-goi ng breast reconstruction with free TRAM flaps at our institution from Febru ary 1, 1989, through May; 31, 1998, were reviewed. Patients were divided in to three groups based on their body mass index: normal (body mass index <25 ), overweight (body mass index 25 to 29), obese (body mass index greater th an or equal to 30). Flap and donor-sire complications in the three groups w ere compared. A total of 936 breast reconstructions with free TRAM flaps were performed i n 718 patients. There were 442 (61.6 percent) normal-weight, 212 (29.5 perc ent) overweight, and 64 (8.9 percent) obese patients. Flap complications oc curred in 222 of 936 naps (23.7 percent). Compared with normal-weight patie nts, obese patients had a significantly higher rate of overall flap complic ations (39.1 versus 20.4 percent; p = 0.001), total flap loss (3.1 versus 0 percent; p = 0.001),flap seroma (10.9 versus 3.2 percent! p = 0.004), and mastectomy flap necrosis (21.9 versus 6.6 percent: p = 0.001). Similarly, o verweight patients had a significantly higher rate of over-all flap complic ations (27.8 versus 20.4 percent; p = 0.033), total flap loss (1.9 versus 0 percent p = 0.004),flap hematoma (0 versus 3.2 percent. p = 0.007), and ma stectomy flap necrosis (15.1 versus 6.6 percent; p = 0.001) compared with n ormal-weight patients. Donor-site complications occurred in 106 of 718 pati ents (14.8 percent). Compared with normal-weight patients, obese patients h ad a significantly higher I ate of overall donor-site complications (23.4 v ersus 11.1 percent; p = 0.005), infection (4.7 versus 0.5 percent; p = 0.01 6), set oma (9.4 versus 0.9 percent; P < 0.001), and hernia (6.3 versus 1.6 percent; p = 0.039). Similarly, overweight patients had a significantly hi gher rate of overall donor-site complications (19.8 versus 11.1 percent; p = 0.003), infection (2.4 versus 0.5 percent; p = 0.039). bulge (5.2 versus 1.8 percent; p = 0.016), and hernia (4.3 versus 1.6 percent: p = 0.039) com pared with normal-weight patients. There were no significant differences in age distribution, smoking history, or comorbid conditions among the three groups of patients, Obese patients, however had a significantly higher inci dence of preoperative radiotherapy and preoperative chemotherapy than did p atients in the other two groups. A total of 23.4 pet-cent of obese patients had preoperative radiation therapy compared with 12.3 percent of overweigh t patients and 12.4 percent of normal-weight patients; 34.4 percent of obes e patients had preoperative chemotherapy compared with 24.5 percent of over weight patients and 17.7 percent of normal-weight patients. Multiple logist ic regression analysis was used to determine the risk factors for flap and donor-site complications while simultaneously controlling for potential con founding factors, including the incidence of preoperative chemotherapy and radiotherapy. In summary, obese and overweight patients undergoing breast reconstruction with free TRAM flaps had significantly higher total flap loss, flap hematom a, flap seroma, mastectomy skin flap necrosis, donor-site infection, donor- site seroma, and hernia compared with normal-weight patients. There were no significant differences in the rate of partial flap loss, vessel thrombosi s, fat necrosis, abdominal flap necrosis, or umbilical necrosis between any of the groups. The majority of overweight and even obese patients who undertake breast rec onstruction with free TRAM flaps complete the reconstruction successfully. Both such patients and surgeons, however, must clearly understand that the risk of failure and complications is higher than in normal-weight patients. Patients who are morbidly obese are at very high risk of failure and compl ications and should avoid any type of TRAM flap breast reconstruction.