Pre-operative Tamsulosin After Minimally Invasive Hysterectomy and Time to Spontaneous Void: A Randomized Controlled Trial
Phase: PHASE2
Conditions: Urinary Retention Postoperative
Sponsor: University of Arizona

 
 
Title: Tamsulosin and Time to Spontaneous Void Following Hysterectomy: A Randomized Controlled Trial 
 
 
Authors: Martina Gabra MD, Christine Hall MD, Lelan McCann MD, Jeenal Shah MD, Ismael Miller MD, Aaron Masjedi 
MD, Stephanie Runke MD, Andrea Aguirre MD 
 
NCT number: NCT04859660 
 
  Date of document: 7/19/2023 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Protocol 
The study was a double-blinded, placebo- controlled randomized control trial that took place at two tertiary 
care hospital campuses in Tucson, Arizona, between June 2021 and January 2023 and involved 11 
attending surgeons. Approval from the institutional review board and registration on ClinicalTrials.gov was 
obtained prior to enrollment. 
 
Women 18-80 undergoing minimally invasive hysterectomy for benign indications were screened for 
participation. In this study, minimally invasive hysterectomy included the following procedures: total vaginal 
hysterectomy (TVH), total laparoscopic hysterectomy (TLH), laparoscopic assisted vaginal hysterectomy 
(LAVH), robotic assisted laparoscopic hysterectomy (RA-TLH), Vaginal Natural Orifice Transluminal 
Endoscopic Surgery (vNOTES), and supracervical hysterectomy. Patients were excluded from analysis if 
they had a planned concurrent incontinence surgery (e.g.  colporrhaphy, vaginal vault suspension or sling 
procedure), a history of bladder cancer, or a medical contraindication to tamsulosin. Participants requiring 
Foley catheterization due to complications such as bladder injury were excluded. Patients were screened 
and consented a week prior to their scheduled surgery. The day of surgery, either 0.4mg tamsulosin or 
placebo was administered on average 1 hour before surgery. This timing was chosen because the peak 
plasma concentration of tamsulosin occurs at 4 hours, so taking into account the total operating room (OR) 
time (from rolling to the OR to leaving the OR suite) the medication onset coincides with the patient arriving 
to the PACU. Randomization was performed by the hospital investigational pharmacy, who dispensed the 
study medication or placebo in a blinded fashion. Both tamsulosin and placebo study medication were 
encapsulated and were indistinguishable from one another. 
 
Each participant underwent a void trial post-operatively by backfilling their bladder with 200cc normal saline 
at the conclusion of the case and removing the foley. Demographics, medical and surgical history, surgical 
details, PACU discharge time, time to void, and adverse events were recorded. Adverse events included 
intraoperative complications, rate of readmission, and emergency department visits. 
 
   Statistical Analysis Plan 
The study aimed to examine two primary objectives: (1) the time to void in the tamsulosin intervention group 
compared to the placebo group, and (2) the time to discharge from the PACU. A reduction of at least thirty 
minutes in time to void was considered a significant change that could alter the standard of care. Based on 
Chao et al, the time to void following a backfill void trial is 181 minutes. To determine if tamsulosin results 
in a 30 minute decrease in time to post-operative void, a total of 77 participants per group were needed, 
assuming a 5% significance level and 80% power. To account for 10% drop out or exclusion, a total of 170 
patients (85 per group allocation) were consented. Wilcoxon rank-sum test was used for continuous 
variables and Fisher's exact test was used for categorical variables. A P value of <0.05 was considered 
statistically significant.