High-frequency ultrasound: a useful tool for evaluating the abdominal wall following free TRAM and DIEP flap surgery.

Background: This is the first study to use a standardized ultrasound protocol to evaluate hernia and abdominal wall laxity following free transverse rectus abdominis myocutaneous (TRAM) and deep inferior epigastric perforator (DIEP) flap surgery.

Methods: All patients who underwent free TRAM and DIEP flap surgery performed by the senior author between the years 1994 and 2003 were recruited for physical examination and ultrasound of the abdominal wall for the dynamic evaluation of hernia and abdominal wall laxity.

Results: A total of 25 of 28 patients were followed up (89 percent). Eleven were in the DIEP flap group (44 percent) and 14 were in the free TRAM flap group (56 percent). Age- and body habitus-matched female volunteers (n = 12) were also used in this study. The mean follow-up was 3.8 years (range, 0.8 to 8.2 years). Although the kappa coefficient was +1 for detection of hernia on physical examination between two independent examiners, the interobserver correlation was poor for detection of bulges (kappa coefficient, +0.53). Ultrasound showed that abdominal wall laxity was statistically highest in the upright position, followed by 30 degrees of truncal flexion, and lowest in the supine position. The amount of abdominal wall laxity detected by ultrasound was significantly higher in the free TRAM flap group than in the free DIEP flap group. Two hernias were detected in the TRAM flap group by ultrasound and one hernia was previously known in the DIEP flap group.

Conclusion: This is the first study to establish a standardized ultrasound protocol as an adjunct diagnostic tool to clinical examination for the dynamic evaluation of postoperative hernia and abdominal wall laxity.