Prospective Study Investigating Optimal Duration of Indwelling Urinary Catheter Following Infraperitoneal Colorectal Surgery and Role of Postoperative Alpha Blockade
Phase: NA
Conditions: Urinary Retention
Sponsor: Cedars-Sinai Medical Center

 
 
 
 
 
PROSPECTIVE STUDY INVESTIGATING THE OPTIMAL DURATION OF INDWELLING URINARY 
CATHETER FOLLOWING INFRAPERITONEAL COLORECTAL SURGERY AND ROLE OF 
POSTOPERATIVE ALPHA-BLOCKADE 
 
 
 
 
Protocol: 
 
 
Version 3, 11/30/2012 
 
 
Lead Investigator: 
 
Phillip Fleshner, MD 
 
 
Division of Colorectal Surgery 
Cedars-Sinai Medical Center 
 
 

 
PROTOCOL 
 
Protocol No./ Title: 
Prospective study investigating the optimal duration of indwelling 
urinary catheter following infraperitoneal colorectal surgery and role of 
postoperative alpha-blockade 
Study Rationale 
The purpose of this study is to evaluate whether a postoperative pelvic 
colorectal patient can safely have an indwelling catheter removed on 
postoperative day one with the addition of a study medication, without a 
statistically significant difference in the incidence of urinary retention 
compared to the standard, accepted approach of delayed removal. 
Study Population: 
Determine the incidence of retention of two groups. A control group of 
72 hours catheterization (Group 1) to 24 hours catheterization plus 
medication (Group 2) to potentially reduce retention.  
 
Data Description:    Non-inferiority study 
pA=0.15, pB=0.15, d=0.15 (tolerance). 
We would like to test 1) If Group 2 is non-inferior to Group 1 (2 is not 
worse than 1). 
 
Power Analysis and Sample Size Calculation: 
 
A sample size for 80% power is 71 per group.  This would be a total of 
142. 
 
Two group test of equivalence in proportions  
 
 
Test significance level, 
a (one-sided) 
  0.050 
Standard proportion, pS 
0.150 
Equivalence limit difference, 
pT - pS, D0 
0.150 
Test expected proportion, pT 
0.150 
Expected difference, pT - pS, D1 
0.000 
Power (%) 
     80 
n per group 
71 
Hypothesis 
Early removal of a urinary catheter in postoperative infraperitoneal 
colorectal surgery patients will experience a similar incidence of acute 
urinary retention than delayed removal, will likely have a lower 
incidence of clinically important urinary tract infections, and experience 
improvement in quality of life measures.   
Study Design: 
Single-center, randomized, prospective study.  Patients in the 24-hour 
catheter removal group will be given 1 mg prazosin orally (per os). The 
pharmacy will be responsible for the distribution of the medication 
when indicated.  The study drug will be given 6 hours prior to catheter 
removal in Group 2 patients. 

 
 
Primary Efficacy 
Endpoint: 
Acute urinary retention (Re-catheterization) 
Secondary 
Endpoints: 
1.  Urinary tract infection (>105 CFU/mL with symptoms) 
2.  Cardiopulmonary complications 
3.  Surgical site infections 
4.  Anastomotic leaks 
5.  Quality of life 
6.  Length of postoperative stay 
7.  Volume of retained urine if re-catheterized (Bladder Scan) 
8.  Adverse side effects from treatment drug 
Safety Endpoints:  
Receiving care patient would have otherwise received. 
Sample size: 
With a sample size of 71 patients per group for a total of 142 patients, 
this study will have 80% power to detect a statistically significant 
difference between acute urinary retention in patients with urinary 
catheter removal 24 hours postoperatively compared to 72 hours 
postoperatively. 
Interim Analysis 
There will be an interim analysis after 71 patients enrolled (half the 
study group) 
Key Inclusion 
Criteria: 
1. Able to freely give written informed consent to participate in the 
study and have signed the Informed Consent Form; 
2. Males or females, >18 years of age inclusive at the time of study 
screening; 
3. American Society of Anesthesiologists (ASA) Class I-III; 
4. Infraperitoneal colorectal surgery (open and/or laparoscopic); 
5. Elective Surgery 
Key Exclusion 
Criteria 
1.  Mentally incompetent or unable or unwilling to provide informed 
consent or comply with study procedures; 
2. Children <18; 
3. No perioperative antibiotics; 
4.  Past or current urinary tract malignancy; 
5. Urinary catheter inserted before surgery; 
6. Chronic kidney insufficiency with Creatinine> 2 
7. Diagnosis of benign prostatic hyperplasia 

 
8. Chronic urinary infections 
9.  Neurogenic bladder 
10.  History of enter vesicle fistula 
11. Pregnancy 
12. Prior surgery of the lower urinary tract 
13. Epidural  
14. Perioperative ureteral stents 
After randomization: 
1. Catheter pulled out inadvertently; 
2. Postoperative complications requiring prolonged monitoring of 
urine output 
3. Postoperative complications requiring early reoperation 
Treatment 
Regimen/ Duration: 
Patients will be assigned into one of three groups:  
Group 1-  removal of urinary catheter 72 hours postoperatively 
(Control) 
Group 2 – randomized to receive prazosin 6 hours prior to catheter 
removal and removal of urinary catheter 24 hours postoperatively 
Treatment Failure/ 
Discontinuation 
Criteria: 
Patients will be discontinued from the trial at any time as a result of any 
other event that in the opinion of the investigator warrants 
discontinuation from the trial. 
Additionally, patients will be excluded after randomization if: 
1. Catheter pulled out inadvertently; 
2. Postoperative complications requiring prolonged monitoring of 
urine output; 
3. Postoperative complications requiring early reoperation 
 

 
2.  SCHEDULE OF EVENTS 
 
 
Group 1: 
Delayed 
Catheter 
removal 
 
Visit Number 
Admission 
 
Informed Consent 
 
 
Demographics 
 
 
Height  
 
 
Medical History1 
 
 
Inclusion/ Exclusion Criteria 
Review 
 
 
Previous /Concomitant 
Medications 
 
 
Physical Exam2  
 
 
Vital Signs3 
 
 
Body Weight 
 
 
Adverse Events4  
 
 
Quality of Life Assessment5 
✓ 
 
Hospital 
Discharge 
or 
Early 
Termination Visit6 
✓ 
 
1. Medical History obtained at index admission including:  Hypertension, Lung Disease, Diabetes  
2. Comprehensive physical exam performed at index admission  
3. Vital Signs (systolic and diastolic blood pressure, heart rate, respiration rate, and temperature) at index admission. 
4. Adverse events (AEs) will be recorded at every visit post screening.  AEs will be followed until resolution. 
5. Quality of Life assessment will be performed on last hospital day prior to discharge (Appendix A) 
6. Early Termination visits are used when a patient withdraws from the study (i.e., prior to hospital discharge). 
 
 

 
 
Group 2: 
Prazosin and 
early catheter 
removal 
 
Visit Number 
Admission 
 
Informed Consent 
 
 
Demographics 
 
 
Height  
 
 
Medical History1 
 
 
Inclusion/ Exclusion Criteria 
Review 
 
 
Previous /Concomitant 
Medications 
 
 
Physical Exam2  
 
 
Vital Signs3 
 
 
Body Weight 
 
 
Adverse Events4  
 
 
Quality of Life Assessment5 
✓ 
 
Hospital 
Discharge 
or 
Early 
Termination Visit6 
✓ 
 
 
 
1. Medical History obtained at index admission including:  Hypertension, Lung Disease, Diabetes  
2. Comprehensive physical exam performed at index admission  
3. Vital Signs (systolic and diastolic blood pressure, heart rate, respiration rate, and temperature) at index admission. 
4. Adverse events (AEs) will be recorded at every visit post screening.  AEs will be followed until resolution. 
5. Quality of Life assessment will be performed on last hospital day prior to discharge (Appendix A) 
6. Early Termination visits are used when a patient withdraws from the study (i.e., prior to hospital discharge). 
 
 

 
 
 
Postoperative Data 
 
Open or Laparoscopic 
 
Reason for surgery (benign or 
cancer) 
 
Type of Surgery (LAR, APR, 
IPAA, etc) 
 
ASA Score 
 
TMN stage 
 
Metastatic Lymph Nodes 
 
Total Mesorectal Excision 
 
Level of anastomosis (<5 cm from 
anal verge) 
 
Neoadjuvant chemotherapy 
 
Neoadjuvant radiation therapy 
 
Intraoperative Fluid Volume (mL) 
 
Intraoperative Blood Loss (mL) 
 
Intraoperative/Postoperative Blood 
Transfusion 
 
Bowel preparation 
 
Diverting stoma 
 
Antibiotic therapy >24 hours 
postoperatively 
 
Morphine equivalent (mg)1 
 
Quality of Life2 
 
1. Morphine equivalent: 7 mg ≈ 1 mg hydromorphone 
2. Quality of Life: obtained on last day of hospitalization 

 
 
 
 
Group 1 
Group 2 
Endpoints 
 
 
Acute urinary retention1 (re-
catheterization) 
 
 
Bladder scan volume (mL) 
 
 
Symptomatic urinary tract 
infection2 
 
 
Cardiopulmonary complications 
 
 
Surgical site infection 
 
 
Anastomotic Leak 
 
 
Adverse side effects  
 
 
Overall complication rate 
 
 
Post-void residual (mL) 
 
 
 
 
 
 
 
 
 
 
 
1. Acute urinary retention defined as the inability to void despite urge and attempt, and/or the inability to void within 8 hours post-
removal of the catheter. 
2. Dysuria and >105 CFU/mL on urine culture