The debate about the advantages of laparoscopic versus open incisional hernia repair is still ongoing. The primary outcomes of already published studies are mainly recurrence, pain and quality of life. Data on postoperative abdominal wall function after these corrections is still lacking. In this single center study muscle strength and transverse abdominal muscle thickness were analysed with regard to open and laparoscopic techniques.
Thirty-five patients that underwent open and laparoscopic midline incisional hernia correction were included. Approximation of the rectus muscles was included in some open procedures but never in laparoscopic correction. Twelve healthy subjects without any abdominal operation functioned as a control group. Trunk flexion muscle strength of all operated patients and 12 healthy subjects was studied with the Biodex® isokinetic dynamometer and conventional abdominal muscle trainers for the rectus and oblique abdominal muscles. All patients underwent ultrasound examination of the abdominal wall for analysing transverse abdominal muscle thickness.
The mean torque/weight (%) for trunk flexion, measured with the Biodex®, was significantly higher in the control compared with the total patient group. Comparing trunk flexion with the Biodex® after either laparoscopic or open incisional hernia repair showed a trend in favour of the open group after adjusting for gender. The muscle strength measured by the conventional abdominal muscle trainers showed no differences between the operation groups. The transverse abdominal muscle thickness difference between rest and contraction was significantly higher in the open repair group.
The isokinetic strength of trunk flexor muscles is reduced after an operation for incisional hernia. There is some evidence that open repair with approximation of the rectus abdominis muscles results in higher muscle strength of the rectus muscles and higher thickness differences between rest and contraction of the transverse abdominis muscles compared to laparoscopic technique.