A retrospective comparison of abdominal muscle strength following breast reconstruction with a free TRAM or DIEP flap

Abdominal weakness is a known potential complication of breast reconstruction with a pedicled or free TRAM flap. It has been presumed that the DIEP flap, which involves no muscle resection, does not compromise abdominal muscle strength but little objective research exists to substantiate this. The aims of this retrospective study were to compare abdominal muscle strength following free TRAM flap and DIEP flap, to compare both groups with a control group and to establish the effect of both procedures on functional activities. Fifty women (23 with a DIEP flap, 27 with a free TRAM flap) plus 32 non-operated controls underwent assessment of their abdominal and back extensor muscle strength on a KIN COM isokinetic dynamometer. Two questionnaires were used to establish the impact on function. The TRAM flap group had significant weakness of the abdominal and back extensor muscles compared with the DIEP flap group and the control group. The trend was for the DIEP flap group to have weaker abdominal muscles than the control group. There was a higher level of abdominal pain and a greater number of reported functional difficulties in the TRAM flap group than in the DIEP flap group. This study demonstrates that whilst the DIEP flap can reduce the strength deficit caused by the free TRAM flap, abdominal weakness can still result from the DIEP flap. A randomised controlled trial is currently underway to investigate the effect of preoperative abdominal exercises in preventing/minimising postoperative abdominal muscle weakness in this group.