When to Remove Penrose Drain After Radical Prostatectomy
Remove the Penrose drain when output is less than 30-50 mL per 24 hours, typically within 24-48 hours after surgery, or consider omitting drain placement entirely in uncomplicated cases.
Evidence-Based Drain Management
The most recent high-quality evidence demonstrates that routine drain placement after radical prostatectomy may not be necessary in properly selected patients. Two randomized controlled trials specifically addressing this question provide clear guidance:
No-Drain Approach is Safe
A 2018 prospective randomized non-inferiority trial 1 and a 2021 single-center RCT 2 both demonstrated that eliminating prophylactic pelvic drain placement after robot-assisted radical prostatectomy (RARP) does not increase complication rates. The 2018 study showed:
- Overall 90-day complications: 17.4% (no drain) vs 26.8% (drain placed), p<0.001
- Major complications (Clavien-Dindo >III): 5.4% vs 5.2%, comparable between groups
- Symptomatic lymphocele rates: 2.2% vs 4.1%, no significant difference
The 2021 trial confirmed these findings with similar complication rates (20.4% no drain vs 28.9% drain, p=0.254) and identical hospital stays.
When Drains Are Used
If you choose to place a drain, the evidence supports:
Remove at 24 hours as standard practice 2. The 2008 AUA Best Practice Policy 3 explicitly states: "There is no evidence that additional antimicrobials should be used when nonurinary tract external drains are removed."
Remove when output <30-50 mL per 24 hours if kept longer, based on principles from other pelvic surgeries 4, 5. The 2023 cancer device infection prevention guideline 4 recommends drain removal "as soon as possible in the presence of <30 ml of daily output or even earlier, not surpassing 7-14 days of use."
Clinical Decision Algorithm
For uncomplicated RARP:
- No drain placement is safe and equivalent to drain use
- Consider this approach for standard cases with watertight anastomosis
If drain is placed:
- Remove at 24 hours postoperatively (standard approach)
- If output remains high, continue until <30-50 mL/24 hours
- Maximum duration should not exceed 7-14 days due to infection risk
Exceptions requiring drain consideration:
- Difficult urethrovesical anastomosis with uncertain watertightness 2
- Extended pelvic lymph node dissection with concern for lymphatic leak
- Intraoperative complications or bleeding concerns
Important Caveats
Avoid prolonged drainage: Drains serve as microbial conduits for pathogens, with an overall risk ratio for infection of 2.47 (95% CI 1.71-3.57) when kept beyond necessary 4. The longer a drain remains, the higher the infection risk.
No antimicrobials at drain removal: The urologic surgery antimicrobial prophylaxis guidelines 3 are clear that prophylactic antibiotics should not extend beyond 24 hours post-procedure and are not indicated at drain removal for non-urinary tract drains.
Lymphocele risk: While theoretical concerns exist about lymphocele formation without drainage after lymph node dissection, the randomized trials showed no significant difference in symptomatic lymphocele rates between drain and no-drain groups 2, 1.