Superficial Endometriosis can be Seen on Ultrasound: A Pilot Application of Saline-Infusion Sonopodography

Abstract

Study Objective Saline-infusion sonoPODography (SPG) is a novel ultrasound procedure that involves introducing fluid into the pouch of Douglas (POD) via the uterus and tubes to create an acoustic window and enhanced contrast between tissues in the posterior compartment. We aim to demonstrate that SPG has utility in diagnosing superficial endometriosis (SE) in a non-invasive fashion. Design Prospective diagnostic accuracy study. Setting Tertiary healthcare center in Sydney, Australia from September 2018-March 2019. Patients or Participants Patients with symptoms of endometriosis planned for laparoscopy were recruited. Interventions SPG was done intra-operatively. Measurements and Main Results Laparoscopy was initiated to ascertain a reference standard visual diagnosis of endometriosis and to suction free fluid from the pelvis. The single SPG operator was blinded to this part of surgery. If fluid collected in the POD, SE of the posterior compartment was evaluated and compared to laparoscopic findings. SE on TVS was defined relative to peritoneal surfaces: 1) superficial hypoechoic areas, 2) hyperechoic projections, 3) cystic areas, 4) pockets of fluid, 5) filmy, irregular adhesions. 15/19 patients underwent successful SPG. Prevalence of overall endometriosis was 15/19 (79%); deep endometriosis (DE) 5/19 (26%); ovarian endometriomas 3/19 (16%); POD obliteration 2/19 (11%); SE 14/19 (74%). SPG diagnostic accuracy results are depicted in Table 1. Conclusion SPG was successfully completed in the majority of patients. In those without advanced endometriosis (i.e. POD obliteration), SPG is even more achievable and provides a reasonable sensitivity for overall SE and very good sensitivity for POD SE, which is the second most common site of SE. At present, SPG needs to be further evaluated but offers hope for a novel non-invasive diagnostic tool for SE.