Risk Factors for De Novo Mixed Urinary Incontinence and Stress Urinary Incontinence Following Surgical Removal of a Urethral Diverticulum

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1 LUTS (2013) 5, ORIGINAL ARTICLE Risk Factors for De Novo Mixed Urinary Incontinence and Stress Urinary Incontinence Following Surgical Removal of a Urethral Diverticulum JaeHeonKIM, 1 Kwang Woo LEE, 2 Jun Mo KIM, 2 Min Eui KIM, 2 and Young Ho KIM 2 1 Department of Urology, Soonchunhyang University Hospital, Seoul, and 2 Department of Urology, Soonchunhyang University Hospital, Bucheon, Korea Objectives: The aim of the present study was to investigate the risk factors for the development of de novo stress urinary incontinence (SUI) and mixed urinary incontinence (MUI) after surgical removal of a urethral diverticulum (UD). Methods: We identified 35 consecutive women that underwent surgical removal of a UD between November 2002 and December 2009, and we retrospectively reviewed their medical records, including patient demographics, pelvic magnetic resonance imaging (MRI), presenting symptoms related to voiding, and outcomes. Results: Among the 35 patients we identified, 28 were included in the study. After UD removal, five of the 28 patients (17.8%) developed de novo MUI, and four of the 28 patients (14.2%) developed de novo SUI. The incidences of SUI and MUI were significantly higher in patients who had a UD that measured over 3 cm in diameter and in patients in whom the UD was located in the proximal urethra. Of the seven patients with a diverticulum over 3 cm, SUI occurred in three (42.8%) (P = 0.038) and MUI occurred in five (45.4%) (P < 0.001). Of the 11 patients with a diverticulum located in the proximal urethra, SUI occurred in five (45.4%) (P = 0.011) and MUI occurred in four (36.4%) (P = 0.011). Conclusion: Significant risk factors for the development of SUI and MUI after transvaginal simple diverticulectomy include a UD measuring over 3 cm and a UD located in the proximal urethra. Key words overactive bladder, stress urinary incontinence, urethral diverticulum 1. INTRODUCTION Urethral diverticula (UD) are not uncommon. The population prevalence is %. 1 3 In women with lower urinary tract symptoms (LUTS), the prevalence is %. 3,4 The most common presenting symptoms are non-specific LUTS, particularly overactive bladder symptoms, pain, and infection. 5,6 Several treatment methods have been described for symptomatic UD. Although transvaginal diverticulectomy is an effective procedure, 7 9 it is difficult because of the normal anatomic fusion of the urethra to the anterior vaginal wall, the lack of cleavage planes, and the involvement of the UD with the urethral sphincter mechanism. Consequently, transvaginal diverticulectomy is sometimes unsuccessful, resulting in a persistent symptomatic UD or other complications such as a urethrovaginal fistula or stress urinary incontinence (SUI). 10 The reported incidence of de novo SUI following UD resection ranges from 4 to 20%. In previous studies, SUI developed immediately after the operation and was associated with UD located in the proximal urethral and UD with an ultrasonically measured size greater than 3cm. 11 There are few reports about factors related with de novo SUI and mixed urinary incontinence (MUI) following surgical removal of a UD. In this study we examined the risk factors for the development of de novo SUI and MUI after transvaginal simple diverticulectomy. 2. METHODS 2.1. Study sample We identified 35 consecutive patients with a UD who underwent transvaginal simple diverticulectomy between November 2002 and December Primary exclusion criteria included preoperative SUI, concurrent antiincontinence and prolapse surgery, and procedures involving a combined flap or any reinforcement. Seven Correspondence: Young Ho Kim, MD, PhD, Department of Urology, Soonchunhyang University Hospital, Korea, 1174 Jung-dong, Wonmi-gu, Bucheon , Korea. Tel: ; Fax: yhkuro@schmc.ac.kr Received 31 August 2012; revised 22 October 2012; accepted 7 November DOI: /luts.12008

2 Incontinence After Removal of UD 155 patients were excluded by these criteria, and 28 patients remained for investigation Methodology We conducted a retrospective review of all patients medical history, physical examination, urodynamic findings, and pelvic magnetic resonance imaging (MRI) results. We then assessed risk factors for the development of de novo SUI and MUI. Preoperative evaluation in all patients included a thorough medical history, physical examination, urinalysis, cystourethroscopy, and pelvic MRI. The preoperative pelvic MRI was performed to confirm the presence of a UD and evaluate its location, size, shape, and possible multiplicities. A follow-up pelvic MRI was performed 3 months after the operation to assess the remnant diverticulum (Fig. 1). The size of the UD was measured on three axes: anteroposterior, transverse, and craniocaudal. The largest diameter among these three measurement techniques was used as the size of the UD. In patients with urinary leakage either preoperatively or postoperatively, an urodynamic study was performed. We defined de novo SUI as postoperative urodynamic SUI. We defined de novo MUI as a combination of SUI and detrusor overactivity during postoperative urodynamic analysis Surgical procedure All operative procedures were performed by the same consulting surgeon. All patients had simultaneous urethroscopy to identify their urethral opening. After the anterior vaginal wall was exposed, an inverted U-shaped incision was made on the anterior vaginal wall. This anterior vaginal wall flap was dissected with Metzenbaum scissors inferiorly and laterally up to the level of the bladder neck in order to expose the peri-urethral fascia. The diverticulum was identified through the peri-urethral fascia by visualization, palpation, or needle aspiration. When the UD was not palpated at the expected location after exposing the peri-urethral fascia, we carefully reviewed the patient s imaging. After identifying the UD, a transverse incision was made into the peri-urethral (a) (b) fascia overlying the UD. The diverticular sac was dissected from the peri-urethral fascia, and after identifying its communication with the urethra the diverticular sac was completely excised. In complex cases, the UD was opened and the wall was mobilized from within. We performed a three-layer closure with non-overlapping sutures that involved the urethral wall, the peri-urethral fascia, and the anterior vaginal wall. After the UD was removed, we filled the bladder with normal saline and confirmed that there was no leakage from the urethra or bladder. The patient s urinary catheter was removed between postoperative days 2 and 14. In more complex cases, a cystourethrogram was performed on postoperative day 14 to confirm healing. All patients were referred for outpatient follow-up at 1 week, 3 months, 6 months and 12 months after surgery Data analysis All statistical comparisons of means were performed using SPSS version 18.0 (SPSS, Chicago, IL, USA). To compare the parameters we used either Mann Whitney U-test or Fisher s exact test. Multivariate analysis was performed with logistic regression. Differences were considered statistically significant when P < RESULTS 3.1. Patient demographics Among the 35 patients identified, seven were excluded due to preoperative SUI or MUI (n = 4, 11.4%) or undergoing a reinforcement procedure (n = 3, 8.57%). A preoperative urodynamic study was performed in 13 patients (46.4%) with urinary leakage, and of these 13 patients 4 were excluded due to SUI or MUI. The mean patient age was 38 years (range ). Presenting complaints included a painful mass in the anterior vaginal wall (n = 10, 35.7%), dysuria (n = 5, 17.8%), urgency or frequency (n = 8, 28.5%), post-void dribbling (n = 9, 32.1%) and dyspareunia (n = 4, 14.2%). One asymptomatic patient had a UD detected incidentally (Table 1). The mean size of the UD measured by pelvic MRI was 2.10 cm (range cm), and seven patients (25.0%) had a UD that measured over 3 cm. In regards to locations, 11 patients (39.2%) had a UD in the proximal urethra, three patients (10.8%) had a UD in the mid-urethra, and 14 patients (50.0%) had a UD in the distal urethra (Table 1). Fig. 1 Preoperative pelvic magnetic resonance image (MRI) showing (a) a urethral diverticulum (UD) that was identified as a right-sided, deviated cystic lesion in the distal urethra measuring 2.6 cm 2.0 cm 1.3 cm. (b) Postoperative MRI showed that the UD was completely removed. (T2-weighted sagittal views.) 3.2. Voiding symptoms after urethral diverticulectomy Voiding symptoms after surgery included urinary leakage (n = 16, 57.1%), urgency/frequency (n = 14, 50.0%), straining to void (n = 3, 10.7%) and residual sensation (n = 6, 21.4%). Dysuria was improved or cured in all patients. Among the 16 patients with postoperative urinary leakage, five patients (17.8%) had MUI, four (14.2%) had SUI, and seven (25.0%) had post-void dribbling. Overall, five of the 28 patients (17.8%) developed de novo MUI and four of the 28 patients (14.2%)

3 156 Jae Heon Kim et al. TABLE 1. Baseline patient characteristics (n = 28) Mean age ± SD, years (range) 38.5 ± 2.7 (20 59) Size of diverticulum, mean (range) 2.10 ( ) 3 cm, n (%) 7 (25.0) <3 cm, n (%) 21 (75.0) Location of diverticulum within urethra Proximal, n (%) 11 (39.2) Mid, n (%) 3 (10.8) Distal, n (%) 14 (50.0) Number of diverticular sacs Single, n (%) 20 (71.4) Loculated, n (%) 8 (28.5) Configuration of UD Simple, n (%) 14 (50.0) Partial horseshoe (U shaped), n (%) 12 (42.8) Circumferential, n (%) 2 (7.14) Remnant diverticulum, n (%) 4 (14.2) Mean body mass index (range) ( ) Positive history of delivery, n (%) 15 (53.5) Positive history of pelvic surgery, n (%) 6 (21.4) Presenting symptom Painful mass of anterior vagina, n (%) 10 (35.7) Post-void dribbling, n (%) 9 (25.7) Urgency or frequency, n (%) 8 (28.5) Dysuria, n (%) 5 (17.8) Dyspareunia, n (%) 4 (14.2) cm, centimeter; SD, standard deviation; UD, urethral diverticulum. developed de novo SUI after UD removal. Among the nine patients with SUI or MUI, three patients (33.3%) underwent secondary anti-incontinence surgery Risk factors for postoperative de novo SUI and MUI The incidences of SUI and MUI were significantly higher in patients with a UD that measured greater than 3 cm in diameter and in patients with a UD located in the proximal urethra. Of the seven patients with a diverticulum over 3 cm, SUI occurredinthree (P = 0.038) and MUI occurred in five (P < 0.001). Of the 11 patients with a diverticulum located in the proximal urethra, SUI occurred in four (P = 0.016) and MUI occurred in five (P = 0.011) (Tables 2 and 3). Age, body mass index (BMI), a history of a vaginal delivery, number of diverticula, configuration of diverticula, and a history of pelvic surgery were not related to the postoperative development of SUI or MUI. A multivariate analysis also showed that a UD greater than 3 cm in diameter and a UD located in the proximal urethra were the primary risk factors for the development of de novo SUI (P = 0.041, p = 0.022, respectively) and MUI (P = , P = 0.032, respectively) (Tables 2,3). 4. DISCUSSION Female UD is an uncommon surgical entity. It was first described in 1805 and was rarely reported until the introduction of positive-pressure urethrography in ,13 Female UD can be diagnosed using a combination of the patient s history, physical examination, cystourethroscopy, and pelvic imaging. However, the diagnosis of a UD is often delayed because most patients present with non-specific LUTS. Recently, more cases of female UD are being diagnosed due to a high index of suspicion and improved diagnostic techniques. 7 Pelvic MRI clearly identifies urethral pathology and provides optimal information for surgical planning by accurately delineating the extent of a UD. 14 We routinely performed a preoperative pelvic MRI to determine the configuration of the UD. Female UD is a complex disease entity with important diagnostic issues. Up to 60% of patients with a UD present with urinary leakage and incontinence. 15 Up to 50% of patients with a UD demonstrate urodynamic SUI. 7,16 Therefore, preoperative evaluation of a patient s continence status is critical. In our study, 13 patients (46.4%) with a UD presented with urinary leakage, and four of these patients (11.4%) were found to have SUI or MUI by a preoperative urodynamic study. Compared to previous studies, the incidence of preoperative SUI or MUI in our study was relatively low. This may be attributable to the relatively young age of our patient population (mean age ± standard deviation, 38.5 ± 2.7 years). The most common and effective treatment for UD is complete excision using a transvaginal approach. 10 However, various complications from urethral diverticulectomy have been reported. These include recurrence in 1 12% of patients, development of a urethrovaginal fistula in % of patients, and SUI in % of patients. 7 As a transvaginal diverticulectomy is invasive and somewhat difficult, we examined preoperative factors that affect the success of the procedure and overall patient outcomes. To achieve satisfactory results, it is essential to use meticulous dissection to define the extent of the UD, completely excise the diverticular sac and its communication with the urethra, and close urethral defects in layers without overlapping sutures or tension. 7,10,17 Several risk factors affecting surgical success have been described. These include the presence of purulent contents in the diverticular sac, UD features such as a large size, a proximal location, a lateral or horseshoe shape, and other factors such as delayed diagnosis and previous urethral surgeries. 10 Our study was unique because all patients were evaluated with a pelvic MRI preoperatively and postoperatively, and all urinary leakage was evaluated with an urodynamic study. Also, all surgical procedures were performed by the same experienced surgeon, and complete removal of the diverticular sac was achieved in most cases. In previous studies, postoperative SUI rates have been between 12 and 49%, 7,16,17,18 although only 10% of patients with postoperative SUI required a secondary intervention in the latter series. 19 In our study, five of 28 patients (17.8%) developed de novo MUI and four of 28 patients (14.2%) developed de novo SUI after UD removal. Among the nine patients with SUI or MUI, three (33.3%) underwent secondary anti-incontinence surgery. The pathophysiology of SUI or MUI after urethral diverticulectomy is unclear. It may be related to the facts that a large diverticulum requires more extensive suburethral dissection and a proximal location may jeopardize the anatomical support of the urethra and bladder neck or

4 Incontinence After Removal of UD 157 TABLE 2. Risk factors for de novo mixed urinary incontinence DDe novo MUI, proportion of patients (%) P-value P-value by multivariate analysis BMI 25 1/3 (33.3%) <25 4/25 (16.0%) Size of diverticulum 3 cm 5/7 (71.4%) < <3 cm 0/21 (0%) Location of diverticulum within urethra Proximal 5/11 (45.4%) Mid 0/3 (0%) Distal 0/14 (0%) Number of diverticular sacs Single 3/20 (15.0%) Loculated 2/8 (25.0%) Configuration of UD Simple 3/14 (21.4%) Partial horseshoe 2/12 (16.6%) Circumferential 0/2 (0%) Previous vaginal delivery Yes 4/15 (26.6%) No 1/13 (7.6%) Previous pelvic surgery Yes 1/6 (16.6%) No 4/22 (18.2%) Fisher s exact test. Multivariate analysis using logistic regression test. BMI, body mass index; MUI, mixed urinary incontinence; UD, urethral diverticulum. TABLE 3. Risk factors for de novo stress urinary incontinence Variables De novo SUI P-value P-value by multivariate analysis BMI 25 1/3 (33.3%) <25 3/25 (12.0%) Size of diverticulum 3 cm 3/7 (42.8%) <3 cm 1/21 (4.8%) Location of diverticulum Proximal 4/11 (36.4%) Mid 0/3 (0%) Distal 0/14 (0%) Number Single 3/20 (15.0%) Loculated 1/8 (12.5%) Configuration Simple 2/14 (14.2%) Partial horseshoe 2/12 (16.6%) Circumferential 0/2 (0%) Delivery Yes 4/15 (26.7%) No 0/13 (0%) Pelvic surgery Yes 0/6 (0%) No 4/22 (18.2%) Fisher s exact test. Multivariate analysis using logistic regression test. BMI, body mass index; SUI, stress urinary incontinence; UD, urethral diverticulum. cause damage to the urethral sphincter mechanism. The urethral musculature and the bladder neck may also be damaged by the inflammation and diverticular mass itself, causing SUI. Three of the 35 patients we identified had a complex UD that involved a very large defect with a circumferential configuration or a previous failed surgery. These three patients received a Martius labial fat pad interposition (MLFI) during their UD resection, and none complained of urinary leakage postoperatively. An optimal treatment modality for patients with a UD and risk factors for postoperative SUI and MUI should be established. An important practical implication of our findings is the greater likelihood of de novo SUI and MUI in women with a large, proximal UD. This risk must be part of the preoperative discussion with patients. This study has several limitations. Although regular preoperative and postoperative evaluations were performed based on our routine protocol, and all surgeries were performed by the same surgeon, follow-up was not consistent because of the study s retrospective nature. Also, asymptomatic recurrences, SUI/MUI masked by a UD, or SUI/MUI masked by surgical correction may have been missed because preoperative and postoperative urodynamic studies were only performed in patients with urinary leakage. Authors did not consider urodynamic factors because of selection bias. Another limitation is the small number of patients. Even though we analyzed the anatomical configuration by MRI, scarce data such as circumferential shape hinders from providing further information. In summary, there is a risk of developing SUI or MUI after a simple diverticulectomy. Consequently, it is difficult to choose an optimal treatment method. Risk factors for developing SUI or MUI after a simple diverticulectomy include a UD greater than 30 mm and a UD located in the proximal urethra. These risk factors should be carefully considered before performing a diverticulectomy. Furthermore, more studies are needed to examine the

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