Postvoid Residual Thresholds Used to Define Chronic Urinary Retention: A Systematic Review.

Context and Objective: Chronic urinary retention (CUR) is a clinically relevant but poorly defined urological condition, often assessed in the clinic using postvoid residual (PVR) volumes. The lack of consensus on the PVR threshold that defines CUR limits diagnostic consistency, clinical decision-making, and comparability of research findings. This review aims to systematically examine how CUR is defined in the current literature, focusing on the reported PVR thresholds. Evidence acquisition: In this systematic-narrative review, a search of five databases (MEDLINE, EMBASE, CENTRAL, Web of Science, and Google Scholar) was conducted in August 2022 and December 2025. Eligible studies included randomized trials, observational studies, and systematic reviews that defined CUR using a PVR threshold in adult patients. Evidence synthesis: A total of 4588 abstracts were screened across two searches, resulting in 14 inclusions. Eleven studies focused on patients with CUR due to benign prostatic hyperplasia. PVR thresholds for defining CUR varied between 150 ml and 1000 ml, with 300 ml being the most reported in 10 studies. Seven studies reported on patients who were able to void, three of which also reported on patients who were unable to void. The remaining seven studies did not report the voiding status of the participants. Four studies repeated the PVR measurements. Six studies used ultrasound or a bladder scan to measure PVR. Conclusions: This review highlights the inconsistency in the definitions and PVR thresholds used to define CUR in the literature. The available evidence was limited and heterogeneous, with substantial variation in study populations, voiding status, and measurement methods. Therefore, the current literature does not provide sufficient consistent evidence to support a single definitive PVR threshold for CUR.