Introduction: Reconstructive urologists often place both a urethral catheter (UC) and suprapubic (SP) catheter intraoperatively to prevent extravasation of undrained urine across anastomosis sutures after various urethroplasty surgeries. Postoperatively, many surgeons leave one catheter to gravity drainage and cap the other. As no consensus exists on which catheter drains the bladder more completely, we sought to identify differences in urine outflow and if both catheters should be opened to maximize bladder drainage.
Methods: Urine output (UOP) records from patients who underwent Stage II Phalloplasty with urethral lengthening from 5/2017 to 11/2020 were retrospectively reviewed. Both a UC and SP catheter were placed to gravity drainage postoperatively. UOP (ml) from each catheter was recorded separately, twice daily, through discharge. Mixed model regression modeling tested for differences in UOP by catheter French (Fr) and time.
Results: In total, 18 patients were identified. In 14 of 18 patients (78%) a 16 Fr UC and SP catheter were placed intraoperatively. Median length of stay was 5.0 days (range: 1.5, 7.0). The aggregate number of 12-hour shift UOP observations was 331 (165 for UC, 166 for SP catheter). SP catheters had a mean 308 ml higher output than UCs per 12-hour shift (p=0.004; 95% CI: 116, 501 ml). Multivariable analysis (Table 1) considering time of day (p=0.149) and catheter Fr (p=0.118) shows that SP catheters had an estimated 345 ml higher output than UCs per 12-hour shift (p=0.001; 95% CI: 174, 517 ml).
Conclusions: Simultaneous bladder drainage by both a UC and SP catheter is associated with significantly greater drainage from the SP catheter (59.7% vs 40.3%). The difference in urinary drainage is likely explained by the SP catheter tip and drainage inlet residing in a more gravity-dependent location, within the funnel-shaped bladder neck (Figure 1). These findings suggest that when using two catheters, both should be placed to gravity drainage. For drainage with a single catheter, SP catheters will likely drain the bladder more completely than UCs.
Source of Funding: NIH R01 Grant #CA20170901 (PI: Maurice Garcia).
Research funding support from the Dr. Richard Onofrio Research Grant to the Cedars-Sinai Transgender Surgery and Health Program