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Table of Contents
Year : 2021  |  Volume : 32  |  Issue : 2  |  Page : 71-76

Factors associated with the success of trial without catheter in acute urinary retention due to benign prostatic hyperplasia

1 Online Research Club; Hue University of Medicine and Pharmacy, Hue University, Hue City, Vietnam
2 Online Research Club, Hue University, Hue City; Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
3 Online Research Club, Hue University, Hue City; School of Medicine, Vietnam National University, Ho Chi Minh City, Vietnam
4 Online Research Club, Hue University, Hue City, Vietnam; Faculty of Medicine, University of Khartoum, Sudan
5 Online Research Club, Hue University, Hue City, Vietnam; Faculty of Medicine, Al-Azhar University, Cairo, Egypt
6 Evidence Based Medicine Research Group; Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam; Department of Clinical Product Development, Institute of Tropical Medicine (NEKKEN), School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
7 Hue University of Medicine and Pharmacy, Hue University, Hue City, Vietnam

Date of Submission21-Sep-2020
Date of Decision10-Dec-2020
Date of Acceptance31-Dec-2020
Date of Web Publication22-Jun-2021

Correspondence Address:
Le Dinh Khanh
Hue University of Medicine and Pharmacy, Hue University, Hue City
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/UROS.UROS_130_20

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Purpose: This study aims to evaluate the parameters that can predict the success or failure of trial without catheter (TWOC) for acute urinary retention (AUR) due to benign prostatic hyperplasia (BPH). Materials and Methods: A prospective cohort study was conducted to include 73 medically treated patients with AUR due to BPH. All patients underwent catheterization and were started on alfuzosin (10 mg/day), followed by TWOC. Age, international prostate symptom score (IPSS), quality of life, prostate volume, and urine volume after catheterization were analyzed. Results: Patients' mean age was 74.23 ± 9.63 years; the first successful and failed TWOC was reported in 47 (64.4%) and 26 patients (35.6%), respectively. On the one hand, 89.4% of the patients continued medical treatment with alfuzosin (10 mg/day) in the first successful TWOC group. On the other hand, 30.8% showed the second successful TWOC and continued medical treatment in the first TWOC failure group. The uni- and multivariable analyses in this study showed that severe lower urinary tract symptoms (IPSS ≥20 points), prostatic pain during digital rectal examination (DRE), high urine volume after catheterization (≥950 mL), and high blood urea (≥4.55 mmol/L) were the predictive factors of TWOC failure. Conclusion: Severe lower urinary tract symptoms, prostatic pain during DRE, large urine volume after catheterization, and high blood urea are the predictive factors for TWOC failure in AUR due to BPH.

Keywords: Acute urinary retention, benign prostatic hyperplasia, predictors, trial without catheter

How to cite this article:
Phuong Hoai DT, Thang Tai LL, Huu Loc TT, Fadlelmola Mohamed MY, Ahmed AM, Huy NT, Khanh LD. Factors associated with the success of trial without catheter in acute urinary retention due to benign prostatic hyperplasia. Urol Sci 2021;32:71-6

How to cite this URL:
Phuong Hoai DT, Thang Tai LL, Huu Loc TT, Fadlelmola Mohamed MY, Ahmed AM, Huy NT, Khanh LD. Factors associated with the success of trial without catheter in acute urinary retention due to benign prostatic hyperplasia. Urol Sci [serial online] 2021 [cited 2023 May 28];32:71-6. Available from: https://www.e-urol-sci.com/text.asp?2021/32/2/71/318996

  Introduction Top

Acute urinary retention (AUR) is uncomfortable, stressful, and even painful (palpable or percussible bladder). Consequently, the patient is unable to pass any urine.[1] AUR is classified as spontaneous or precipitated. Spontaneous AUR is considered when no evidence of stimulating factors exists except benign prostatic hyperplasia (BPH). Conversely, precipitated AUR is considered when stimulating factors including BPH and others (e.g., preceding surgery, stroke, urinary tract infection, and some anticholinergic medicaments; the Proscar Long-Term Efficacy and Safety Study) are present.[2],[3],[4] Primary AUR increases with age, and it usually occurs in men >60 years old with incidence rates of 3.06 and 5.23 per 1000 men annually and in 2010, respectively.[5],[6],[7]

BPH can lead to bladder outlet obstruction, and it is the most common cause of AUR in men (at least 65% of men with AUR).[8],[9],[10] Therefore, according to the recommendation of the American Urology Association (AUA), treatment of AUR due to BPH includes the emergency release of urine in the bladder, and BPH is treated using α-1 blockers (alfuzosin and tamsulosin, among others) at the same time.[11]

Previously, surgery was considered an early treatment option. However, recently, the trial without catheter (TWOC) has gradually replaced surgery. Under the AUA recommendation, patients with AUR due to BPH should undergo TWOC at least once before being considered for surgery.[11] The decrease in the rates of surgical interventions was beneficial for patients.[12],[13] Therefore, this study investigates the predictive factors for successful TWOC for AUR due to BPH based on random forest algorithm along with the cutoff sensitivity and specificity. These factors would help physicians better in assessing the initial TWOC outcome and choosing the optimal treatment for patients.

  Materials and Methods Top

Sample population

A prospective cohort study was conducted at the Hue University of Medicine and Pharmacy, Hue University Hospital, from February 2018 to October 2019 to include male patients who were hospitalized for BPH-associated AUR. The study excluded patients with prostate cancer, prostatitis, urethral injury, pelvic fracture, urethral gravel, urethral stricture, bladder neck sclerosis, tabes dorsalis, spinal cord injury, spinal cord inflammation, or drug-induced AUR (pseudoephedrine and antihistamine, among others).

Study procedure and data collection

The summary and scheme of the study procedure are described in [Figure 1]. All patients with AUR due to BPH were initially managed with emergency urinary catheter combined with α-1 blockers and antibiotics. Consequently, the urinary catheter was removed, and the patients' results were evaluated after 3 days. All study parameters used for developing the RF model in this study were collected from the initial evaluation data during the period. Clinical factors, including age, classification of urinary retention, progression time of lower urinary tract symptoms, urinary signs, prostate clinical examination, comorbidities, and total urinary volume after catheterization, were recorded in addition to laboratory and imaging parameters (parameters of urine sample test, bladder–prostate ultrasound, and blood count test). Moreover, the international prostate symptom score (IPSS) and quality of life (QoL) were also recorded for assessment.[14] After removing the catheter (TWOC), the results were evaluated in the next 24 h. According to Guang-Jun et al., “α1-blockers provide substantial benefit in increasing a satisfactory micturition within 24 h after TWOC for men with AUR due to BPH, even though the long-term effectiveness remains uncertain.”[15] Thus, the 24-h mark after TWOC was chosen. A successful TWOC was considered a postvoid residual volume of <100 mL and the patient not needing recatheterization within 24 h after removing the catheter. Subsequently, the patients were categorized into two groups: the first successful group and the first failed group, based on the success of the initially applied TWOC. Consequently, the aforementioned predictive factors were statistically investigated. Furthermore, precipitated AUR refers to the inability to urinate following a triggering event (e.g., nonprostate-related surgery, catheterization, anesthesia, or ingestion of medications with sympathomimetic or anticholinergic effects, antihistamines, or others). All other AUR episodes are classified as spontaneous.[4]
Figure 1: The summary of study procedure has been described

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Statistical analysis

The Statistical Package for the Social Sciences, Version 23, and R software produced by SPSS Inc., IBM, Chicago, IL. were used to analyze the data. Moreover, descriptive analysis was used to describe the study characteristics between the two groups. The characteristics of the patients in the two groups were compared using either Fisher's exact test (for categorical variables) or Mann–Whitney U test (for continuous variables). Subsequent multivariable analysis was used to analyze the association between the predictive factors and the TWOC outcomes. Consequently, the RF was used to select variables for multivariable analysis for detecting the interaction and nonlinearity without prespecification. Based on the results of the model selection stage, the selected variables were included in the logistic regression model to conduct multivariable analysis to evaluate the independent predictability of each factor. Furthermore, the receiver operating characteristic (ROC) analysis was used to select the appropriate cutoff values for continuous prognostic parameters.

Ethics approval and consent

This study was accepted by the ethical approval committee and Institutional Review Board of Hue University of Medicine and Pharmacy (No. 1435/QD-DHYD, February 7, 2018). Informed consent was obtained from the patients.

  Results Top

This study included 73 patients. TWOC was a success and a failure in 47 (64.4%) and 26 patients (35.6%), respectively. All 47 patients with a successful first TWOC continued medical treatment with alfuzosin and regularly followed up [Figure 2]. During the follow-up, five patients (10.6%) failed with medical treatment and received transurethral resection of the prostate (TURP) surgery. Moreover, 26 patients who had a failed first TWOC were recatheterized and underwent a second TWOC. The second TWOC was successful in only eight patients (30.8%), whereas the remaining 18 patients received long-term catheterization (three cases, 16.7%) or surgical (15 cases, 83.3%) treatments.
Figure 2: Management in case of trial without catheter

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Demographics along with the results of the comparative analysis of the study characteristics are summarized in [Table 1]. Urine volume after catheterization was 0.91 ± 0.32 L and 1.16 ± 0.27 L in the successful and failed TWOC (P < 0.001) groups, respectively. No significant difference in age and progression time of the lower urinary tract symptom was noted in the successful TWOC group compared with patients in the failed TWOC group. Pairwise comparisons of each category based on the Bonferroni correction did not show specific differences in pairs.[16] However, the percentage of precipitated AUR was higher in the successful TWOC group (P = 0.018). Furthermore, IPSS and QoL scores were significantly lower in the successful TWOC group (P < 0.001 for both). Patients in the successful TWOC group were less likely to endure pain during prostate examination (P = 0.003). Consequently, no significant difference exists in the percentage of comorbidities between the two groups. The results of the comparative analysis of laboratory characteristics are also presented in [Table 1].
Table 1: Description of study characteristics between 2 groups: Trial without catheter success and trial without catheter failure

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Only four factors after model training (i.e., IPSS, prostatic pain during digital rectal examination [DRE], urea, and urine volume after catheterization) were used for conducting the multivariable logistic regression [Table 2]. These risk factors have a negative impact on TWOC outcome. When approaching the probability of TWOC failure, IPSS (odds ratio [OR] = 1.279, 95% confidence interval [CI] = 1.117–1.466), prostatic pain during DRE (OR = 11.273, 95% CI = 1.858–68.376), urea (OR = 1.370, 95% CI = 1.020–1.841), and urine volume after catheterization (OR = 14.988, 95% CI = 1.528–147.055) were shown. From the ROC curve analysis, based on Youden's index, a score of 20 in the IPSS (57.7% sensitivity and 95.7% specificity), urea = 4.55 mmol/L (84.6% sensitivity, 44.7% specificity), and urine after catheterization = 950 mL (73.1% sensitivity, 74.5% specificity) were the cutoff points to predict TWOC failure. Moreover, the sensitivity and specificity to predict TWOC pain failure during the examination were 34.6% and 93.6%, respectively.
Table 2: Univariable and multiple logistic regression to predict trial without catheter failure (n=73)

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  Discussion Top

TURP is one of the methods for BPH treatment.[17] However, TURP may also be indicated in AUR due to BPH but may not be beneficial to patients. According to the current guidelines,[18] the first-line AUR treatment due to BPH combines urethral catheterization with α-blockers. Subsequently, initial TWOC is performed. TWOC means the removal of the catheter after 3 days of emergency urethral catheterization and α-blocker therapy. Fitzpatrick et al.[19] reported successful TWOC in 61% of their population. Among them, 86.7% and 5.6% were treated with α-blockers and underwent TURP, respectively. According to Hagiwara et al.[20] and Zhengyong et al.,[21] the successful TWOC rates were 88.8% and 66.9%, respectively. These results agree with the results of this study with 64.4% and 30.8% of the first and second successful TWOCs, respectively. Most patients (89.4%) in the successful TWOC group received medical treatment, which continued with alfuzosin, while 10.6% needed surgery because medical treatment did not improve their condition. It is expected that the second or third TWOC could succeed after the failure of the first TWOC. However, Oelke et al.[22] demonstrated that successful TWOC rate for the second or third time was not high, and most patients with TWOC failures required surgical interventions.

This study showed that TWOC was effective for many patients, and the surgical intervention for AUR due to BPH can be limited. However, this procedure is not beneficial for all patients. One of the crucial factors associated with TWOC success is the combined treatment with α-1 blockers. In the ALFAUR study, TWOC failure was higher in patients aged ≥65 years and with ≥1000 mL urine volume obtained after catheterization. However, successful TWOC rate increased two times in patients who were treated with alfuzosin for 2–3 days before TWOC.[23] Consequently, α-1 blockers before TWOC were also analyzed in Cochrane's report where the overall successful TWOC rate tended to be superior in the group treated with α-1 blockers compared with placebo (relative risk [RR] = 1.39, 95% CI = 1.18–1.64) by using alfuzosin (RR = 1.31, 95% CI = 1.10–1.56) or tamsulosin (RR = 1.86, 95% CI = 1.17–2.97).[24] Further studies showed that α-1 blockers (alfuzosin) could help increase the effectiveness of TWOC and reduce the number of patients needing surgery.[12],[13]

In a previous study, the use of five 5-alpha-reductase inhibitors (5-ARIs) besides α-1 blockers could reduce the prostate size by approximately 18%–28% after 6–12 months of treatment.[25] According to the EAU guidelines, clinical effects relative to placebo are seen after a minimum treatment duration of at least 6–12 months.[26] The effect of the drug may fail to reach the significance level before symptom recurrence. Thus, this study used alfuzosin. Several studies suggested factors that could predict TWOC failure. According to Fitzpatrick et al.,[20] these factors are age (≥70 years), prostate size (≥50 g), IPSS (>20), urine volume after catheterization (≥1000 mL), and spontaneous AUR. However, Manjunath and Hofer[27] suggested that the predictors of TWOC failure were age (>69 years) and urine volume after catheterization (>654 mL). Furthermore, Bhomi and Bhattachan[28] suggested that prostate size (>40 g), IPSS (>16), urine volume after catheterization (>800 mL), and intravesical prostatic protrusion (>8 mm) were the predictors of TWOC failure. The proposed predictive factors of TWOC failure in this study were severe urinary tract symptoms (IPSS ≥ 20), pain during a DRE, high urine volume after catheterization (V ≥950 mL), and high blood urea (urea ≥4.55 mmol/L) [Figure 3]. Age and prostate size under ultrasound did not show any association with the TWOC results. Moreover, pain during DRE is one of the new potential factors that could be quickly evaluated in clinical practice. However, quantitative factors did not have a unified agreement. Hence, a systematic review may be necessary to overcome the limitations of the original studies and provide valuable information for clinical practice.
Figure 3: ROC of parameters in predicting the probability of TWOC failure

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In one study, successful TWOC after days 1, 2, and 7 of urethral catheterization was observed in 44%, 51%, and 62% of patients, respectively.[29] However, Tenke et al.[30] reported that the incidence of urinary tract infections increases daily by 3%–7% with the presence of urethral catheterization. Moreover, the multivariate analysis performed by Fitzpatrick et al.[20] and Saint et al.[31] revealed that catheterization for 3 days did not affect successful TWOC rate but was related to urinary tract infection, urinary leakage, catheter obstruction, and prolonged hospitalization due to side effects. Thus, this study chose a 3-day model to match the research conditions.

Although medical history and clinical assessments were taken by senior urologists, the feeling of pain varies for each patient. Thus, it can be considered a limitation of this study. In future studies, the measurement of pain should be valid if pain during the rectal examination was evaluated as a predictor. Furthermore, the relatively small sample size enabled focusing on the first successful TWOC. However, the generalizability of this study is still in question even though some results were similar to previous studies.

  Conclusions Top

TWOC is the first method of choice to treat AUR due to BPH. A multivariable analysis of the predictive factors of the results of TWOC showed that severe lower urinary tract symptoms (IPSS ≥20 points), pain during DRE, urine volume after catheterization (V ≥950 mL), and high blood urea (≥4.55 mmol/L) are the factors that predict TWOC failure.

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Conflicts of interest

There are no conflicts of interest.

  References Top

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  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2]


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