Colorectal natural orifice specimen extraction surgery in an Asian cohort: does obesity matter?

Background: Natural orifice specimen extraction (NOSE) via the anus or vagina is an alternative to conventional transabdominal extraction. We aimed to evaluate the safety and outcomes of NOSE following colorectal surgery in obese Asian patients.

Methods: We performed a retrospective cohort study of patients who underwent laparoscopic colorectal resection with NOSE for non-metastatic cancer or benign disease between February 2021 to October 2023. Clinical T4 or N2 disease on preoperative imaging were excluded from NOSE. Patient characteristics and perioperative outcomes were compared between patients with Body Mass Index (BMI) <25 kg/m² versus BMI ≥25 kg/m².

Results: Forty-nine consecutive patients underwent elective colorectal surgery with attempted NOSE over the 33-month study period. Forty patients (81.6%) had resection for a diagnosis of colorectal cancer. Twenty-seven (55.1%) patients had BMI<25 kg/m² and 22 (44.9%) had BMI≥25 kg/m², with a median BMI of 22.1 kg/m² and 27.8 kg/m² in the lower and higher BMI cohorts respectively. Patient gender, albumin level, operative indication, and type of surgery performed were comparable. There were no statistical differences in the NOSE conduit used, operative duration, blood loss, postoperative gastrointestinal recovery time, and complication rates. Median postoperative length of stay was 3 days in either group. Two patients (9.1%) failed NOSE in the high BMI cohort. There were no open conversions. Amongst patients with colorectal cancer, distribution of pT and pN stages, total lymph node harvest, and tumour diameter were similar.

Conclusions: Colorectal NOSE surgery amongst selected obese Asian patients results in similar perioperative outcomes and postoperative morbidity rates compared to non-obese patients.