The characteristics of residual pneumoperitoneum after laparoscopic colorectal surgery.

INTRODUCTION: Despite the popularity of laparoscopic surgery, it remains unclear whether residual pneumoperitoneum influences the patient's postoperative course. This study aimed to evaluate the characteristics of residual pneumoperitoneum. METHODS: This retrospective study included 201 Japanese patients who had undergone elective laparoscopic colorectal surgery. The patients were divided into groups, with and without anastomotic failure; the non-anastomotic failure group was further divided into subgroups, with and without residual pneumoperitoneum. Patient characteristics were compared between the various groups. RESULTS: The group with residual pneumoperitoneum included 57 patients (30.3%). Percutaneous drainage was required for one patient with residual pneumoperitoneum. Univariate analyses revealed that residual pneumoperitoneum was associated with low values for body mass index (BMI) and subcutaneous fat area (SFA). Furthermore, relative to the group with anastomotic failure, the group without anastomotic failure but with residual pneumoperitoneum had lower values for inflammatory markers. CONCLUSION: Low BMI and SFA values were identified as risk factors for residual pneumoperitoneum. Inflammatory markers may be useful as indicators for avoiding emergent surgery when it is difficult to differentiate between asymptomatic residual pneumoperitoneum and free air related to anastomotic failure.