An Easy Prediction of Urinary Incontinence Duration After Retropubic Radical Prostatectomy Based on Urine Loss the First Day After Catheter Withdrawal M. Van Kampen,* I. Geraerts, W. De Weerdt and H. Van Poppel From the Departments of Rehabilitation Science (Faculty of Kinesiology and Rehabilitation Science) (MVK, IG, WDW) and Physiotherapy (MVK) University Hospital Gasthuisberg and Division of Urology, University Hospital (HVP), Katholieke Universiteit Leuven, Leuven, Belgium Purpose: We sought to predict the duration of urinary incontinence after radical prostatectomy based on potential risk factors. Materials and Methods: We included 104 patients after radical retropubic prostatectomy at University Hospital Gasthuisberg, Leuven. To evaluate incontinence a 24-hour pad test, a 1-hour pad test, a visual analog scale and a questionnaire were used. Patients were considered continent when they stopped wearing incontinence pads, when 24 and 1-hour pad tests showed less than 2 gm urine loss, and when patients considered themselves continent. On univariate and multivariate analyses we examined the influence of different risk factors on the duration of incontinence. Results: The amount of urine loss the first day after catheter withdrawal was the only predictor of the duration of urinary incontinence on univariate and multivariate analyses. Patient age was significant but only on univariate analysis. The duration of incontinence after prostatectomy was estimated. The average time needed to regain continence was 8, 16, 29, 29 and 70 days in men who lost 2 to 50, 51 to 100, 101 to 200, 201 to 500 and more than 500 gm urine, respectively, on day 1. Conclusions: The amount of urine loss on day 1 after catheter withdrawal is the most important predictive factor in terms of regaining urinary continence after radical prostatectomy. An estimation table can provide realistic information to the patient regarding the duration of urinary incontinence. Abbreviations and Acronyms FUPL functional urethral profile length MUCP maximal urethral closure pressure PFME pelvic floor muscle exercises Submitted for publication October 9, 2009. Study received approval from the University Hospitals Katholieke Universiteit Leuven Medical Ethics Commission. * Correspondence: Department of Physiotherapy, University Hospital, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium (telephone: 00-32-16 342182; FAX: 00-32-16 342184; e-mail: marijke.vankampen@uz.kuleuven.ac.be). Key Words: prostate, prostatectomy, urinary incontinence, questionnaires, catheterization FOR many years radical prostatectomy has been the treatment of choice for local eradication of prostate cancer. A considerable number of patients can temporarily or definitively experience some degree of urine leakage. Bianco et al confirmed that high volume hospitals and surgeons had better patient outcomes but they also found substantial variation in outcomes among individual high volume surgeons in high volume groups. 1 Different risk factors might influence the restoration of continence after radical prostatectomy. A number of preoperative factors have been investigated in the literature, including patient age, prior transurethral resection and prior hormonal treatment. Patients younger than 65 years were shown to achieve continence sooner than older patients. 2 8 Only Wille et al found no significant relation between older age and longer lasting 0022-5347/09/1816-2641/0 Vol. 181, 2641-2646, June 2009 THE JOURNAL OF UROLOGY Printed in U.S.A. Copyright 2009 by AMERICAN UROLOGICAL ASSOCIATION DOI:10.1016/j.juro.2009.02.025 www.jurology.com 2641
2642 PREDICTING URINARY INCONTINENCE AFTER PROSTATECTOMY incontinence. 9 Patients who underwent prior transurethral resection seemed to be at increased risk for incontinence in certain studies, 2,4,8 although another report contradicted this. 9 Prior hormonal treatment was not a significant risk factor for incontinence. 2 Surgical procedures have been identified as risk factors for incontinence. The amount of blood loss is a factor, and preservation of the neurovascular bundles and bladder neck has shortened the time needed to attain continence, 2,6,10 13 although others could not confirm these data. 5,9,14,15 In some series bladder neck preservation appeared to accelerate the return of continence 13 but again this was not confirmed in other studies. 5,14,15 Other factors are MUCP and FUPL. Many patients with incontinence after radical prostatectomy have shorter FUPL and lower MUCP than continent patients, suggesting that post-radical prostatectomy incontinence is invariably due to sphincter insufficiency. 7,11 Surgical margin status and pathological tumor stage have not been found to be significant. 2,4 Only in the study by Moul et al was pathological stage a factor that significantly predicted urinary incontinence. 16 Some postoperative factors have been found to carry a risk of urinary incontinence. An important loss of urine the first day after catheter withdrawal was reported to predict a longer time needed to regain continence. 4,17 The use of postoperative radiation therapy did not have an effect on early return of continence according to most studies. 2,14 Only Jarow found a significant effect. 18 There still exists no consensus about the effect of preoperative and postoperative PFME on the duration of incontinence, although most studies have shown positive effects. 4,19,20 No more than 2 studies have described predicting the duration of urinary incontinence after radical prostatectomy. 3,17 Still, this is one of the key questions in patients who experience urinary leakage after catheter removal. Twiss et al developed a continence index to predict the continence level, pad requirements and bother due to incontinence 3 months after retropubic radical prostatectomy. 3 Ates et al developed a prediction equation of the duration of incontinence after laparoscopic prostatectomy based on urine loss divided by micturition volume, termed the urine loss ratio. 17 Time to continence was classified as early 0 to 3 months, midterm 4 to 12 and late 13 to 24. 17 The first aim of this study was to determine risk factors for incontinence after radical prostatectomy. The second aim was to accurately predict the postoperative duration of incontinence. MATERIALS AND METHODS Patients A total of 104 consecutive patients who underwent open radical retropubic prostatectomy at University Hospital Gasthuisberg and were able to visit the hospital once weekly for physiotherapy treatment until they achieved continence were included in this prospective study. All study patients had incontinence immediate after catheter withdrawal and provided informed consent. All patients underwent surgery performed by the same surgeon. The 104 patients belonged to a group of 140 consecutive patients who had undergone radical retropubic prostatectomy. Of these men 13 (9%) were continent immediately after catheter withdrawal and could not be included in analysis, and 23 were excluded from study due to the inability to come to the hospital once weekly for physiotherapy because of transport problems. In the latter men the duration of incontinence was not exactly known and physiotherapists treated them at home. The urethral catheter was removed 11 to 15 days after surgery. Patients remained in the hospital for catheter removal for 24 hours and were instructed to drink 2.5 l water. Daily urine loss was noted in a dairy a minimum of 3 days per week, starting from the day of catheter withdrawal. Continence Definition Patients were considered dry if they stopped wearing protective pads and lost less than 2 gm on the 24-hour pad test. Subsequently they returned to the hospital for a 1-hour pad test. For the 1-hour pad test patients wore a pad for 1 hour. At the beginning of the test they drank 500 ml water, waited 30 minutes and then performed activities such as walking, jumping, lifting, coughing and standing. At the end of the test the pad was weighed. A loss of urine of less than 2 gm was considered continence. At the same time patients were asked to assign a score on the visual analog scale from 0 completely dry to 10 completely wet as a final confirmation of continence status. Patients also had to be able to perform all normal activity without urine loss. Treatment One physiotherapist treated all patients once per week until they were continent. The treatment program started with an information session about the function of the pelvic floor muscles. Physiotherapy treatment consisted of PFME and biofeedback. When patients had weak pelvic floor muscles, they received electrical stimulation, mainly to teach them which muscles to contract. All patients received a home program, consisting of 60 contractions of the pelvic floor muscles per day in any of 3 positions, including supine, sitting or standing. They also learned how to integrate these contractions into daily living activities. Incontinence Risk Factors We investigated a number of preoperative factors, including patient age, previous transurethral resection and prior hormonal treatment, factors related to surgery such as blood loss, nerve sparing operation, bladder neck preservation, surgical margin status and
PREDICTING URINARY INCONTINENCE AFTER PROSTATECTOMY 2643 pathological stage, and postoperative factors, that is urine loss on day 1 after catheter withdrawal, to establish which predictor variables were significantly related to the duration of incontinence after radical prostatectomy. None of the patients received any surgical therapy for incontinence during followup. Statistics Descriptive statistics were used to document patient characteristics and calculate the incidence and percent of the different risk factors. Univariate analysis was used to establish which predictor variables were significantly related to the duration of incontinence after surgery. For categorical variables of 2 levels (bladder neck preservation and surgical margin status) the unpaired t test was used and for categorical variables of more than 2 levels (nerve sparing operation and pathological tumor stage) ANOVA was used. For 2 categorical variables of 2 levels (previous transurethral resection and prior hormonal treatment) we used descriptive statistics because 1 level consisted of only a few patients. For continuous variables (age, blood loss and urine loss on day 1 after catheter withdrawal) linear regression was done. Subsequently multivariate analysis was used. All variables were included, not only significant ones. Predictive variables with a significance level of p 0.05 were retained for prediction. Finally, the prediction of duration of urinary incontinence after radical prostatectomy was made by calculating percentiles. The study received ethical approval from the Medical Ethics Commission of the University Hospitals Katholieke Universiteit Leuven responsible for human/animal experimentation. RESULTS Mean patient age was 64 years (range 49 to 75). One, 3 and 6 months after radical prostatectomy 48%, 81.7% and 89.4% of patients, respectively, were continent on the 24 and 1-hour pad tests. During treatment 9 patients were lost to followup and were considered dropouts. Two patients were not dry after 1 year but each was completely continent 16 months after surgery. They were considered outliers and excluded from the prediction study. Four patients with a weak pelvic floor received electrical stimulation. Only 3 patients (3.2%) had undergone prior transurethral resection and 3 (3.2%) had received prior hormonal treatment (table 1). In 75 patients (79.0%) no nerve sparing operation was done, in 12 (12.6%) 1 nerve was spared and in 8 (8.4%) the 2 nerves were spared. Bladder neck preservation was achieved in 78 men (82.1%). Of the patients 40% had positive surgical margins, including focal, minimal and obvious positive margins, while in 2%, 61.8% and 33% pathological tumor stage was pt1, pt2 and pt3, respectively. On univariate analysis a higher amount of urine loss the first day after catheter withdrawal and Table 1. Incontinence duration and clinical variables in 95 patients after retropubic radical prostatectomy Predictor Variables No. Pts (%) Mean Incontinence Duration (days) p Value Age 0.024 Prior transurethral resection: No 92 (96.8) 37.58 Yes 3 (3.2) 52.67 Prior hormonal treatment: No 92 (96.8) 38.05 Yes 3 (3.2) 38.33 Blood loss during surgery 0.590 Nerve sparing operation: 0.862 No 75 (79.0) 40.32 Unilat 12 (12.6) 29.75 Bilat 8 (8.4) 39.00 Bladder neck preservation: 0.447 No 17 (17.9) 51.94 Yes 78 (82.1) 35.00 Surgical margin status: 0.148 Neg 56 (59.5) 38.37 Pos 38 (40.5) 41.30 Unknown 1 Pathological tumor stage: 0.156 pt1 2 (2.2) 120.50 pt2a b c 58 (61.8) 36.88 pt3 31 (33.0) 31.59 Unknown 4 Day 1 urine loss 0.0001 older age were the only factors predictive of a longer duration of incontinence (table 1). Multivariate analysis was then performed, including all predictor variables. In combination age was no longer significant. Only the amount of urine loss on day 1 after catheter withdrawal had a significant predictive value for the duration of incontinence after radical prostatectomy. This means that a great loss of urine on day 1 after catheter withdrawal predicts a longer time needed to achieve continence. An estimation table was made based on this predictor variable (table 2). In this table the amount of urine loss on day 1 after catheter withdrawal was divided into the categories 2 to 50, 51 to 100, 101 to 200, 201 to 500 and greater than 500 gm, each including an approximately equal number of patients (23, 15, 13, 16 and 26, respectively). In each category the 25th, 50th and 75th percentiles of the duration of incontinence were calculated. Of patients who lost between 2 and 50 gm on the 24-hour pad test on day 1 after catheter withdrawal 25% were dry by 4 days, 50% were dry by 8 days and 75% needed 19 days to become dry (see figure). DISCUSSION Today prostate cancer is the most common organ malignancy. 8 Despite many improvements in surgical techniques urinary incontinence remains a rele-
2644 PREDICTING URINARY INCONTINENCE AFTER PROSTATECTOMY Table 2. Clinician prediction table of urinary incontinence duration after radical prostatectomy by urine loss on day 1 after catheter withdrawal Urine Loss (gm) Duration (days) 25th Percentile 50th Percentile 75th Percentile 2 50 4 8 19 51 100 9 16 33 101 200 9 29 35 201 500 13 29 53 Greater than 500 49 70 97 vant postoperative problem. In this study continence was achieved in only 81.7% of patients at 3 months and in 89.4% at 6 months. Results were higher in a previous study, in which 88% and 98% of men were continent at 3 and 6 months, respectively. 4 A possible explication may be the higher number of patients with severe incontinence. Many patients feel limited in daily activities. 20 Predicting the duration of incontinence is helpful for providing a realistic insight in the problem. Such a prediction can only be made with confidence when risk factors for incontinence after radical prostatectomy are considered. In our study the amount of urine loss on day 1 after catheter withdrawal and patient age were significant risk factors related to the duration of urinary incontinence. On multivariate analysis only urine loss on day 1 after catheter withdrawal was associated with the duration of incontinence. A greater amount of urine loss on day 1 after catheter withdrawal was associated with longer time to continence. Only 2 studies have mentioned urine loss on day 1 after catheter withdrawal as a risk factor for longer persistence of incontinence. 3,17 According to Ates et al urine loss on days 3 to 8 is a more reliable predictive factor 17 but because our patients were asked to measure urine loss a minimum of 3 times per week, we could not provide these data. In all other studies urine loss was not assessed on day 1 after catheter withdrawal. In the literature most studies have shown a significant relation between older age and increased incontinence duration. 2 8 In our study all other factors, such as blood loss, neurovascular bundle preservation, bladder neck preservation, surgical margin status and pathological tumor stage, were not significantly related to the Predicting number of days of urinary incontinence in 95 patients after radical prostatectomy according to urine loss on day 1 after catheter withdrawal.
PREDICTING URINARY INCONTINENCE AFTER PROSTATECTOMY 2645 duration of incontinence after radical prostatectomy. Still, in the literature all of these factors have been disputable. Some groups identified them as risk factors for urinary incontinence after radical prostatectomy, while others could not confirm these findings. Surgical margin status has never been identified as a risk factor. 2 For prior hormonal treatment we used descriptive statistics but in the literature it has never been defined as a risk factor. 2 We also used descriptive statistics for prior transurethral resection, so that it could not be found to be a risk factor for predicting the duration of incontinence. This finding must be considered with caution. Only 3 patients had previously undergone transurethral resection and they needed an average of 52 days before continence was achieved, while in the group without prior transurethral resection 37 days were required. Another question may be asked. Is it possible that the influence of risk factors decreased because all of our patients were treated with PFME, while in the other studies no training was given? According to several studies MUCP and FUPL are important predictive factors. 2,3,18 These factors were not analyzed in our study. We question the need for a full urodynamic evaluation in a cohort of patients who achieved full continence 1 to 4 weeks later. Also, in this study no patient received postoperative radiation therapy before he was fully continent. A limitation of this study is that preoperative incontinence was not assessed. Nevertheless, it has been documented to be a determining factor for postoperative urinary incontinence. 5,8 Patients are concerned about how long they will have to cope with incontinence after radical prostatectomy. After determining the significant risk factors a prediction of the duration of urinary incontinence could be made. Based on this predictive factor a prognostic scheme to predict the duration of urinary incontinence may be made. Using this estimation table the health care professional can provide the patient with more precise information about the expected duration of incontinence (table 2). This information would decrease patient emotional stress and make him more motivated to continue rehabilitation. The amount of urine loss on day 1 was divided into 5 categories. Further division of the last category of greater than 500 gm into the subcategories 501 to 750, 751 to 1,000 and greater than 1,000 gm did not improve the prediction. The 2 patients considered to be outliers lost 588 and 1,769 gm urine, respectively, on day 1 after catheter withdrawal. Only 2 studies were found about predicting urinary incontinence based on different risk factors. Twiss et al predicted incontinence 3 months after retropubic surgery. 3 The assessment of incontinence was based on 5 clinical parameters and scored on an ordinal scale. Ates et al used the urine loss ratio to predict early, midterm and late incontinence after laparoscopic prostatectomy. 17 Our study provides a straightforward prediction based on the objective 24-hour pad test the day after catheter withdrawal with a fixed fluid intake in each patient. Our prediction is a helpful guideline for patients and physicians to estimate the duration of incontinence. CONCLUSIONS The amount of urine loss on day 1 after catheter withdrawal is the most important factor for predicting incontinence after retropubic radical prostatectomy. An estimation table can provide realistic information to the patient regarding the duration of urinary incontinence. REFERENCES 1. 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