Subgroups of failure after surgery for pelvic organ prolapse and associations with quality of life outcomes: a longitudinal cluster analysis

Background: Treatment outcomes after pelvic organ prolapse surgery are often presented as dichotomous “success or failure” based on anatomic and symptom criteria. However, clinical experience suggests that some women with outcome “failures” are asymptomatic and perceive their surgery to be successful and that other women have anatomic resolution but continue to report symptoms. Characterizing failure types could be a useful step to clarify definitions of success, understand mechanisms of failure, and identify individuals who may benefit from specific therapies. Objective: This study aimed to identify clusters of women with similar failure patterns over time and assess associations among clusters and the Pelvic Organ Prolapse Distress Inventory, Short-Form Six-Dimension health index, Patient Global Impression of Improvement, patient satisfaction item questionnaire, and quality-adjusted life-year. Study Design: Outcomes were evaluated for up to 5 years in a cohort of participants (N=709) with stage ≥2 pelvic organ prolapse who underwent surgical pelvic organ prolapse repair and had sufficient follow-up in 1 of 4 multicenter surgical trials conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Pelvic Floor Disorders Network. Surgical success was defined as a composite measure requiring anatomic success (Pelvic Organ Prolapse Quantification system points Ba, Bp, and C of ≤0), subjective success (absence of bothersome vaginal bulge symptoms), and absence of retreatment for pelvic organ prolapse. Participants who experienced surgical failure and attended ≥4 visits from baseline to 60 months after surgery were longitudinally clustered, accounting for similar trajectories in Ba, Bp, and C and degree of vaginal bulge bother; moreover, missing data were imputed. Participants with surgical success were grouped into a separate cluster. Results: Surgical failure was reported in 276 of 709 women (39%) included in the analysis. Failures clustered into the following 4 mutually exclusive subgroups: (1) asymptomatic intermittent anterior wall failures, (2) symptomatic intermittent anterior wall failures, (3) asymptomatic intermittent anterior and posterior wall failures, and (4) symptomatic all-compartment failures. Each cluster had different bulge symptoms, anatomy, and retreatment associations with quality of life outcomes. Asymptomatic intermittent anterior wall failures (n=150) were similar to surgical successes with Ba values that averaged around −1 cm but fluctuated between anatomic success (Ba≤0) and failure (Ba>0) over time. Symptomatic intermittent anterior wall failures (n=82) were anatomically similar to asymptomatic intermittent anterior failures, but women in this cluster persistently reported bothersome bulge symptoms and the lowest quality of life, Short-Form Six-Dimension health index scores, and perceived success. Women with asymptomatic intermittent anterior and posterior wall failures (n=28) had the most severe preoperative pelvic organ prolapse but the lowest symptomatic failure rate and retreatment rate. Participants with symptomatic all-compartment failures (n=16) had symptomatic and anatomic failure early after surgery and the highest retreatment of any cluster. Conclusion: In particular, the following 4 clusters of pelvic organ prolapse surgical failure were identified in participants up to 5 years after pelvic organ prolapse surgery: asymptomatic intermittent anterior wall failures, symptomatic intermittent anterior wall failures, asymptomatic intermittent anterior and posterior wall failures, and symptomatic all-compartment failures. These groups provide granularity about the nature of surgical failures after pelvic organ prolapse surgery. Future work is planned for predicting these distinct outcomes using patient characteristics that can be used for counseling women individually.