Changes in abdominal wall thickness during laparoscopy: implications for the use of magnetic assisted surgery

Introduction: Recently, magnetic solutions have been proposed to minimize surgical invasiveness. These are comprised of deployable instruments containing magnets which are inserted into the abdominal cavity through a single access point. The manipulation of the internal elements occurs via magnets held on the external surface of the abdominal wall. This technology relies on the magnetic force between the magnets, which is inversely related to the abdominal wall thickness (AWT). The aim of this study was to establish the expected change in AWT from before and after initiation of pneumoperitoneum. Material and methods: Patients scheduled for laparoscopic procedures were assessed by ultrasound for AWT immediately before and during laparoscopy. Change of AWT during laparoscopy was calculated. Statistical analysis was performed using Student's t-test. Results: Thirty-two patients undergoing various laparoscopic procedures were included. Twenty patients were male (62.5%) and ten were morbidly obese (31%). Mean age was 51 years (range 18-76) and average BMI was 28.1 kg/m² (range 19.0-41.0). AWT decreased on average by 15.6% once pneumoperitoneum was initiated in both obese and non-obese patients (p = .01). Conclusion: Our data suggest that following preoperative assessment of AWT with abdominal wall ultrasound, more patients than expected might be candidates for the use of trans-abdominal magnetic devices.