Preoperative Ultrasound Indications Determine Excision Technique for Bowel Surgery for Deep Infiltrating Endometriosis: A Single, High-Volume Center

Abstract

Study objective: To identify bowel nodule features of deep infiltrating endometriosis (DIE) measured through preoperative ultrasound scanning that influence laparoscopic surgical strategy.

Design: A retrospective study.

Setting: Malzoni Clinic-Endoscopica Malzoni Department, Center for Advanced Endoscopic Gynecological Surgery, Avellino, Italy.

Patients: Patients undergoing laparoscopic surgery between January 1, 2014, and December 31, 2018, for clinically suspected DIE with previous ultrasound evaluation ≤1 month before intervention.

Intervention: Use of sonographic measurements to determine laparoscopic excision technique (segmental bowel resection, discoid resection, shaving) for DIE with bowel involvement.``` MEASUREMENTS AND MAIN RESULTS: Of 5051 DIE surgeries, 4983 were included; 1494 (29.9%) bowel resections (512 bowel segmental resections and 982 nodulectomies [967 shaving and 15 discoid resections]) were performed, accounting for 34.3% and 65.7% of all bowel procedures, respectively. Preoperative sonographic findings and surgical reports were collected. Sensitivity and specificity of preoperative ultrasound evaluation for all types of DIE lesions were calculated, and sonographic measurements of bowel nodules and different surgical techniques were compared. According to preoperative sonographic measurements, most nodules excised by segmental resection had a longitudinal diameter of 3 to 7 cm, none were <3 cm; all nodules excised by nodulectomy (shaving or discoid resection) had a longitudinal diameter <3 cm. Mean thickness (maximum depth of muscular layer infiltration) of identified bowel nodules estimated through ultrasound scanning was 13.4 mm ± 4.8 mm (mean ± standard deviation) and 5.8 mm ± 2.7 mm for lesions removed by segmental resection and nodulectomy, respectively, and there was a statistically significant difference between them (p <.05). Of the 512 segmental resected bowel nodules, 143 (28%) had a maximum depth ≥9 mm, 354 (69%) had 7 to 9 mm, and 15 (3%) had <7 mm (6 mm, with length >4 cm). All shaved nodules had thickness ≤7 mm. The 15 nodules excised by discoid resection (1.5% of nodulectomies) were <25 mm, but thickness ranged from 7 to 9 mm.

Conclusion: The need for segmental resection in DIE with bowel-infiltrating nodules depends on the degree of muscular layer infiltration and corresponding thickness (muscularis rule) in addition to nodule length and can be accurately identified by preoperative ultrasound evaluation.

Keywords: Bowel nodule; DIE; Laparoscopic surgery; Muscularis.