Movement of target organs and anatomical landmarks caused by body position change during urological laparoscopic surgery

INTRODUCTION: The aim of our study was to elucidate the impact of patients' physical characteristics on the movement of target organs and anatomical landmarks by comparing supine and lateral CT images. METHODS: This study consisted of 55 patients who underwent laparoscopic surgery in the lateral position. CT images of the area between the abdomen and pelvis were taken preoperatively with patients in both supine and lateral positions. We measured the moving distance of target organs and anatomical landmarks on the body surface used for access port settings. We investigated which covariates from patients' body composition most affected moving distance in correlation analysis. Then, using multiple linear regression analysis, we examined whether we could predict the movement of target organs and anatomical landmarks solely based on information obtained from supine CT images. RESULTS: The moving distance of both the hilum of the kidney and the outer edge of the rectus abdominis muscle were significantly associated with some physical characteristics. Multiple regression analysis showed that a larger visceral fat area could be a useful index for predicting the movement of the kidney toward the counter side. Lower CT density of back muscles and higher BMI could be useful indexes for predicting the movement of the rectus abdominis muscle. CONCLUSION: Our results suggested that body composition characteristics obtained from preoperative CT images can help predict the movement of target organs and anatomical landmarks used to determine proper port-site placement for laparoscopic surgery performed with the patient in the lateral position.