The empty pelvis syndrome: a core data set from the PelvEx collaborative

Abstract

Background: Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

Method: Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

Results: One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

Conclusions: EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Fig. 1

Study flow diagram showing longlisting, shortlisting and confirmatory stages

Fig. 2

a, Resectional phase of pelvic exenteration is completed and the perineum reconstructed so that it is water-tight; to establish the volume of increased pelvic dead space, the table is tilted into the reverse-Trendelenburg position so the fluid level is parallel to the pelvic inlet (between sacral promontory and pubic symphysis) and the volume of saline required to fill this space is recorded. b, Preoperative scan using Data Analysis Facilitation Suite (DAFS) version 3.6 by Voronoi, deep learning-driven software capable of automated CT scan 3D segmentation courtesy of the BiCyCLE group at St Mark's Hospital; this may predict the increased volume of pelvic dead space based on surgical roadmap planning and the line of the pelvic inlet—the area in brown is the planned resectional specimen