OP12.04: Saline infusion sonoPODography (SISP): a novel technique to visualise and understand the pouch of Douglas (POD)

The prevalence of endometriosis in patients with infertility can reach up to 70%. Non-invasive tools to understand disease severity remain limited. Many patients facing infertility proceed with routine evaluation of the uterine cavity and fallopian tube patency via saline infusion sonohysterography (SIS) and hysterosalpingo-contrast-sonography (HyCoSy). Our aim is to determine the feasibility of evaluating the pouch of Douglas (POD), often affected in advanced stages of endometriosis, with the already-infused SIS/HyCoSy fluid, which may spill through patent tubes into the pelvis. We call this technique saline infusion sonoPODography (SISP). Sixteen sequential patients were prospectively observed through routine SIS or HyCoSy procedures. After placement of the catheter, 10-20 mL of saline is used to assess the cavity. If a HyCoSy is indicated, after cavity assessment, 10-20 mL of aerated gelofusion with saline is used to assess tubal patency. In patients with a collection of fluid in the POD, we assessed the space for evidence of obliteration, intra-abdominal adhesions, and fixed pelvic structures. Using 3D capabilities, volumetric data was collected and the POD was reconstructed. SIS and HyCoSy were indicated in 6 and 10 patients, respectively. In total, 9 of 16 (56.3%) patients had fluid collect in the POD (4 and 5 of patients undergoing SIS and HyCoSy, respectively). In patients undergoing HyCoSy with demonstrated tubal patency (at least unilaterally), 5 of 10 did not have POD fluid collection. The 3D volume analysis of the fluid collections in the POD ranged from 1.01 to 10.42 cm3, with a mean of 6.74 cm3. Intra-abdominal adhesions were identified in the POD of 3 patients with POD fluid collection. We believe SISP is a novel technique to visualise and better understand the POD. Though its potential utility needs to be further evaluated, in its most basic form, if it is performed in combination with SIS or HyCoSy, it may reveal useful supplementary information for the patient and healthcare provider. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.