Early Versus Delayed Removal of the Urethral Catheter After Percutaneous Nephrolithotomy: A Systematic Review of Safety, Feasibility and Impact on Enhanced Recovery

Protocol and registration

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement [9]. The protocol was submitted to the International Prospective Register of Systematic Reviews (PROSPERO) prior to data extraction and has now been registered (CRD4202461XXXX). The registration was confirmed after the initial submission of this manuscript. We have disclosed this timeline transparently to ensure compliance with systematic review reporting standards.

Search strategy

A comprehensive search was performed in the following electronic databases from inception to May 2026: PubMed/MEDLINE, Embase (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and Web of Science. The search strategy combined terms related to PCNL, urethral catheterization, timing of removal, and enhanced recovery. The full PubMed search string was:

(�Percutaneous Nephrolithotomy�[Mesh] OR �PCNL� OR �percutaneous nephrolithotomy� OR �percutaneous nephrolithotripsy�) AND (�Urinary Catheterization�[Mesh] OR �urethral catheter� OR �Foley catheter� OR �transurethral catheter� OR �bladder catheter�) AND (�Time Factors�[Mesh] OR �early removal� OR �early catheter removal� OR �delayed removal� OR �catheter removal timing� OR �postoperative care� OR �enhanced recovery�).

No language restrictions were applied. Reference lists of included studies and relevant review articles were hand-searched for additional eligible studies. Grey literature was searched via Google Scholar and conference proceedings from the American Urological Association, European Association of Urology, and Soci�t� Internationale d�Urologie (2020�2026).

Eligibility criteria

Studies were included if they met the following criteria:

• Population: Adult patients (=18 years) undergoing PCNL for renal calculi.
• Intervention: Early urethral catheter removal, defined as removal within 24 hours postoperatively (postoperative day 0 or 1).
• Comparator: Delayed removal, defined as removal beyond 24 hours (postoperative day =2) or catheter removal coinciding with nephrostomy tube removal.
• Outcomes: At least one of the following reported�urinary retention, recatheterization, pain scores, CAUTI, hematuria, nephrostomy site leakage, time to ambulation, or length of stay.
• Study Design: Randomized controlled trials (RCTs), prospective or retrospective cohort studies, and case-control studies.

Exclusion criteria were: pediatric populations, tubeless PCNL without nephrostomy tube placement, studies where the urethral catheter was not placed or was removed intraoperatively, case reports, reviews, editorials, and studies lacking a comparator group with delayed removal.

Study selection

Two independent reviewers screened titles and abstracts against the eligibility criteria. Full texts of potentially eligible studies were retrieved and assessed independently. Disagreements were resolved through discussion or consultation with a third reviewer.

The selection process was documented using a PRISMA flow diagram (Table 1).

Data extraction

Data were extracted independently by two reviewers using a standardized, piloted form. Extracted data included: first author, year of publication, country, study design, sample size, patient demographics (age, sex, stone burden), surgical details (tract size, operative time, nephrostomy tube size), definition of early removal, timing of removal in both groups, criteria used to determine eligibility for early removal, and all reported outcomes.

Risk of bias assessment

For RCTs, the Cochrane Risk of Bias 2 (RoB 2) tool was used, assessing bias arising from the randomization process, deviations from intended interventions, missing outcome data, measurement of the outcome, and selection of the reported result. For observational studies, the Newcastle-Ottawa Scale (NOS) was employed, evaluating selection, comparability, and outcome assessment. Studies scoring 7�9 were considered low risk of bias, 4�6 moderate, and <4 high risk.

Data synthesis

Meta-analysis was performed using Review Manager (RevMan) version 5.4 when three or more studies reported the same outcome with comparable definitions. Dichotomous outcomes (urinary retention, recatheterization, CAUTI, nephrostomy leakage) were pooled using risk ratios (RR) with 95% confidence intervals. Continuous outcomes (pain scores) were pooled using standardized mean differences (SMD) due to varying pain scales. A random-effects model was applied to account for anticipated clinical and methodological heterogeneity. Heterogeneity was assessed using the I� statistic, with values >50% considered substantial. Where meta-analysis was inappropriate due to clinical or methodological heterogeneity, a narrative synthesis was performed. Subgroup analyses were planned for RCTs versus observational studies, standard PCNL versus mini-PCNL, and different definitions of early removal (<12 hours vs. 12�24 hours). Publication bias was assessed by funnel plot asymmetry when ten or more studies were available.

Study selection and characteristics

The database search yielded 914 records. After removing 247 duplicates, 667 titles and abstracts were screened. Fifty-three full-text articles were assessed for eligibility, and 41 were excluded: 18 did not include a delayed removal comparator, 10 were reviews or editorials, 7 had insufficient outcome data, 4 included tubeless procedures exclusively, and 2 were pediatric studies. Twelve studies met the final inclusion criteria: four randomized controlled trials [5�8] and eight observational studies [10�17], published between 2012 and 2026. The PRISMA flow diagram is shown in Table 1. (Table 2).

The 12 studies comprised 1,847 patients: 912 in early removal groups and 935 in delayed removal groups. Sample sizes ranged from 56 to 312 patients. Five studies were conducted in Asia (India, China, Pakistan, Iran), three in Europe (Turkey, UK, Italy), two in North America, one in South America, and one in Egypt. The definition of �early removal� varied: four studies defined it as within 6�12 hours postoperatively [5,10,12,15], six as POD 1 morning (18�24 hours) [6,7,11,13,14,16], and two as within 24 hours without further specification [8,17]. Delayed removal was most commonly at 48�72 hours or at the time of nephrostomy removal.

Risk of bias

Among the four RCTs, two were judged at low risk of bias [5,7], one had some concerns regarding blinding of outcome assessment [6], and one had some concerns due to unclear allocation concealment [8]. The eight observational studies scored between 6 and 8 on the Newcastle-Ottawa Scale: six were rated low risk of bias [10,11,13,14,16,17] and two moderate risk [12,15]. No study was excluded based on quality assessment.

Primary outcome: Urinary retention and recatheterization

All 12 studies reported urinary retention rates. In the early removal group, retention rates ranged from 0% to 8.3%, while in the delayed removal group, rates ranged from 0% to 6.1%. Meta-analysis of 11 studies (one study had zero events in both arms and was excluded from the meta-analysis) showed no significant difference in urinary retention between early and delayed removal (RR 0.89, 95% CI 0.52�1.52, p=0.67) with low heterogeneity (I�=12%) (Table 3).

Recatheterization rates were reported in 10 studies. The pooled risk ratio was 1.12 (95% CI 0.65�1.93, p=0.68; I�=22%), indicating no statistically significant increase with early removal (Table 4). Causes for recatheterization in both groups were predominantly clot retention and, less commonly, atonic bladder. Importantly, studies with stricter patient selection criteria�clear urine, hemodynamic stability, absence of significant intraoperative complications�reported recatheterization rates below 2% in the early removal group [5,7,10,14].

Sensitivity Analysis Restricted to RCTs: A sensitivity analysis restricted to the four randomized controlled trials was conducted to confirm the robustness of the primary outcomes against potential selection bias from observational studies. The pooled risk ratio for urinary retention in the four RCTs was 0.94 (95% CI 0.38�2.31, p=0.89; I�=0%), and for recatheterization was 1.05 (95% CI 0.42�2.62, p=0.92; I�=0%). These findings are consistent with the overall pooled estimates and demonstrate that the null finding is not driven by observational study bias (Supplementary Table S3).

Secondary outcomes

Catheter-Associated Urinary Tract Infection (CAUTI): Nine studies reported CAUTI rates using CDC or similar criteria. The pooled analysis demonstrated a statistically significant 69% reduction in CAUTI with early removal (RR 0.31, 95% CI 0.16�0.59, p<0.001; I�=0%) (Table 5). CAUTI rates in the early removal groups ranged from 0% to 2.1%, compared with 2.8% to 11.4% in the delayed removal groups.

Pain Scores: Ten studies assessed postoperative pain using visual analog scale (VAS) or numeric rating scales (NRS). The meta-analysis of pain scores at 24 hours postoperatively (or closest available time point after delayed removal) demonstrated significantly lower pain scores in the early removal group (SMD -1.25, 95% CI -1.78 to -0.72, p<0.001), though heterogeneity was substantial (I�=78%) (Table 6). All individual studies directionally favored early removal.

Subgroup analysis by timing of pain assessment partially explained the observed heterogeneity. In the four studies that assessed pain while the catheter was indwelling in the delayed group, the effect size was larger (SMD -1.82, 95% CI -2.31 to -1.33, I� = 45%). In the six studies that assessed pain after catheter removal in both groups, the effect was attenuated but remained statistically significant (SMD -0.81, 95% CI -1.23 to -0.39, I� = 52%). All individual studies directionally favored early removal, and the consistent directionality across studies is the more reliable finding. Given the substantial heterogeneity, the overall pooled estimate should be interpreted as a sensitivity analysis rather than a definitive effect size.

Nephrostomy Site Leakage: Eight studies reported nephrostomy site leakage as an outcome. There was no significant difference between early and delayed removal groups (RR 1.05, 95% CI 0.68�1.62, p=0.83; I�=0%) (Table 7). Leakage was generally mild and self-limiting in both groups, rarely requiring additional intervention.

Hematuria: Seven studies reported postoperative hematuria requiring intervention (clot evacuation or transfusion). No significant difference was found (RR 0.92, 95% CI 0.54�1.57, p=0.76; I�=0%).

Time to Ambulation and Length of Stay: Five studies reported time to ambulation, all showing significantly earlier mobilization in the early removal group (mean difference ranging from 8 to 18 hours). Six studies reported hospital length of stay. [REVISED] While all individual studies trended toward a shorter stay with early removal, the pooled analysis did not reach statistical significance (mean difference -0.4 days, 95% CI -0.9 to 0.1, p=0.13; I�=62%). The high heterogeneity reflects differences in discharge criteria and healthcare system practices across centers. A confirmed length-of-stay benefit cannot be claimed based on the current evidence and should be interpreted with caution.

Subgroup and sensitivity analyses

Subgroup analysis by study design (RCTs vs. observational) showed consistent findings for all outcomes. As detailed in Section 3.3.1, a sensitivity analysis restricted to the four RCTs confirmed the null findings for urinary retention and recatheterization.

We had planned a subgroup analysis comparing early removal within <12 hours versus 12�24 hours. However, only four studies employed a strict <12-hour removal protocol [5,10,12,15], and these studies reported heterogeneous outcome definitions that precluded meaningful pooled comparison with the 12�24-hour subgroup. Descriptively, recatheterization rates were comparably low in both subgroups (0�4.1% in <12 h; 0�2.8% in 12�24 h), suggesting no appreciable safety difference. A formal comparison would require larger, prospectively designed studies with harmonized definitions.

Restricting the analysis to studies with the strictest patient selection criteria (clear or light pink urine, no intraoperative complications) eliminated recatheterization events in the early removal group entirely (0/425 vs. 8/390). Subgroup analysis by PCNL type (standard 24�30F vs. mini-PCNL =20F) was limited by data availability but showed no differential effect on outcomes.

This systematic review provides the most comprehensive synthesis to date on the safety and benefits of early urethral catheter removal after PCNL. The principal finding is reassuring: early removal�whether within 6�12 hours or on the morning of POD 1�does not increase the risk of acute urinary retention or recatheterization compared with leaving the catheter for 48 hours or more. This finding was consistent across randomized trials and observational studies, with low statistical heterogeneity. When appropriate patient selection criteria are applied, the recatheterization risk in the early removal group approaches zero.

The biological and clinical rationale supporting these findings is robust. The detrusor muscle recovers normal contractile function within hours of general or regional anesthesia, and the practice of overnight intravenous hydration ensures a steady urine output that prevents clot stasis and primes the bladder for a natural first void [18]. The argument that a full bladder increases intrarenal pressure and causes nephrostomy leakage is not borne out by our meta-analysis, which showed no difference in leakage between groups. The nephrostomy tract, sealed by a fibrin matrix and surrounded by parenchymal compression within the early postoperative period, appears to provide a competent barrier that resists significant urine extravasation when the bladder fills [19,20].

The significant reduction in CAUTI�a 69% relative risk reduction�is particularly compelling. CAUTI remains a quality metric in surgical care, associated with increased morbidity, prolonged hospitalization, and excess costs [2,3]. Every day a catheter remains in situ is an independent risk factor for bacteriuria. Our findings directly support the Centers for Disease Control and Prevention recommendation to remove urinary catheters as soon as they are no longer necessary [3], and extend this principle to the PCNL population where it has been inconsistently applied.

Patient comfort is a less quantifiable but equally important outcome. The large and statistically significant reduction in pain scores associated with early removal aligns with the universal clinical observation that urethral catheters are a major source of postoperative distress. Bladder spasms, the sensation of a foreign body in the urethra, and restriction of movement collectively degrade the recovery experience [21]. The psychological benefit of being �tube-free� should not be underestimated; it marks a transition from patient to recovering person and reinforces the efficacy of surgery.

Several additional limitations warrant consideration. Geographically, the included studies originate predominantly from Asia and Europe, with only two from North America and one from South America. This concentration may limit the generalizability of findings to healthcare settings with different perioperative protocols, discharge thresholds, and patient expectations. Additionally, the inclusion of studies spanning 2012 to 2026 introduces temporal heterogeneity; older studies may reflect surgical techniques and catheter materials that have since evolved. However, the consistency of findings across both older and more recent publications provides some reassurance that the safety of early catheter removal is not contingent on contemporary technology alone. Future studies from a broader range of geographic settings would enhance external validity.

The strengths of this review include its prospective protocol, comprehensive search strategy spanning multiple databases, inclusion of both RCTs and observational data, and rigorous risk-of-bias assessment. The quantitative synthesis provides pooled effect estimates that can inform clinical decision-making and guideline development.

However, several limitations must be acknowledged. First, the definition of �early� removal varied across studies from 6 to 24 hours, introducing clinical heterogeneity. While our descriptive findings suggest comparable safety across this range, the optimal hour remains undefined. Second, patient selection criteria differed, and the �real-world� applicability of these findings depends on applying appropriate exclusion criteria: ongoing hematuria with clots, hemodynamic instability, collecting system injury, and planned second-look nephroscopy should prompt delayed removal. Third, the included studies were generally small to medium-sized; the pooled sample of 1,847 patients provides reasonable power for common outcomes like retention and CAUTI but limited power for rare events. Fourth, blinding of patients and assessors was not possible given the nature of the intervention, though this is unlikely to have influenced the objective primary outcome of recatheterization. Fifth, most studies excluded patients with significant intraoperative complications, limiting generalizability to all-comers. Sixth, as noted in the Results, the pooled length-of-stay analysis was non-significant with substantial heterogeneity, and a confirmed LOS benefit cannot be claimed. Finally, publication bias cannot be excluded, though funnel plot asymmetry was not apparent for the primary outcome.

The implications for clinical practice are clear. Surgeons performing PCNL can and should consider early urethral catheter removal as the default for uncomplicated cases. A simple, pragmatic protocol�clear urine, stable patient, removal at 6:00 AM on POD 1�is safe and effective. This aligns with ERAS principles that have been successfully applied to other major urological procedures like cystectomy and nephrectomy [4,22]. Our review suggests that PCNL should not be an exception.

Future research should focus on defining the earliest safe time point for removal�could catheters be removed on the evening of surgery in selected patients? Large, multicenter RCTs with standardized protocols and health-economic analyses are needed to confirm these findings and evaluate the impact on length of stay and cost. Patient-reported outcome measures, including validated quality-of-recovery scores, would add granularity to the comfort benefits we have identified.

Early removal of the urethral catheter within 24 hours after uncomplicated PCNL is safe and does not increase the risk of urinary retention, recatheterization, or nephrostomy site leakage compared with delayed removal. It significantly reduces CAUTI rates and postoperative pain while accelerating mobilization. Early catheter removal should be integrated into enhanced recovery protocols for PCNL. A simple, criteria-based approach�clear urine, hemodynamic stability, and uncomplicated surgery�identifies the appropriate candidate for safe early removal.

Supplementary-Materials