Abstract
Introduction Laparoscopic surgery is increasingly performed for benign gynecologic ovarian tumors in Japan. Laparoscopic surgery for obese patients is sometimes challenging due to their increased abdominal wall thickness. The aim of this study was to evaluate whether obesity affects the time of primary trocar insertion and related perioperative outcomes in gynecologic laparoscopic surgery using the open (Hasson) technique. Methods This retrospective cohort study included 85 patients who underwent laparoscopic surgery for benign adnexal tumors at Kobe City Medical Center West Hospital, Kobe, Japan, between January 2023 and August 2025. Patients were classified into the normal-weight group (BMI 18.5-24.9 kg/m², n=65) and the obese group (BMI ≥25 kg/m², n=20). The primary outcome was the time of primary trocar insertion. Secondary outcomes included wound closure time, thickness of subcutaneous fat tissue and umbilical wall, complication rates, and correlations among these variables. Correlations among operative times and anatomical parameters were explored using Spearman's rank correlation. A mixed-effects linear model was applied to evaluate the association between BMI and primary trocar insertion time while adjusting for the surgeon as a random effect and case order as a fixed effect. Results The median primary trocar insertion time was four minutes (range, 1-21) in the normal-weight group and six minutes (range 2-20) in the obese group. Patients with obesity had significantly thicker subcutaneous fat tissue (median 35 mm (range 15-51) vs 20 mm (7-44), p<0.01) and umbilical wall thickness (median 21 mm (6-45) vs 10 mm (3-31), p<0.01). In a mixed-effects linear model accounting for surgeon and case order, higher BMI showed a non-significant trend toward longer primary trocar insertion time (0.17 minutes per BMI unit; 95% CI, -0.01 to 0.34; p = 0.06), while case order did not significantly affect primary port insertion time (-0.075 minutes per case; 95% CI, -0.17 to 0.02; p = 0.11). Spearman's analysis showed a moderate correlation between subcutaneous fat tissue and umbilical wall thickness (ρ=0.63, p<0.01). Complication rates did not differ significantly (normal-weight 10.8% vs. obese 20%, p=0.28). Conclusion In this retrospective cohort, laparoscopic access using the open technique was performed in normal-weight and obese patients without significant prolongation of primary trocar insertion. Obese patients had greater subcutaneous fat and umbilical wall thickness, but these did not clearly increase technical difficulty after accounting for surgeon-related factors. While not conclusive evidence of procedural equivalence, the findings suggest that minimally invasive access can be achievable in selected obese patients with a standardized technique and careful preoperative assessment. Surgeon experience remains an important determinant of access outcomes. Prospective studies are needed to confirm these observations and refine evidence-based guidance for laparoscopic entry in patients with elevated BMI.