- Email: [email protected]
Evaluation of Urodynamic Findings Before and After Mid-Urethral Tape Sling Operation for Female Stress Urinary Incontinence
Original Article
Evaluation of Urodynamic Findings Before and After Mid-Urethral Tape Sling Operation for Female Stress Urinary Incontinence Jie Zheng, MD, Ke Xu, MD, Yaofei Sun, MD, Chuanyu Sun, MD, Qiang Ding, MD, and Zujun Fang, MD* From the Department of Urology, Huashan Hospital, Fudan University, Shanghai, China (all authors).
ABSTRACT Study Objective: To compare the urodynamic findings in female patients with stress urinary incontinence (SUI) before and after a mid-urethral tape sling operation. Design: Multi-channel urodynamic study (Canadian Task Force classification II-3). Setting: Department of Urology, Huashan Hospital, Shanghai, China. Patients: Women with SUI. Interventions: One hundred ten patients underwent tension-free vaginal tape (TVT) surgery from September 2002 to December 2004 and 312 patients underwent tension-free vaginal tape–obturator (TVT-O) surgery from January 2005 to December 2011. The study was performed in all patients before surgery and at 3 and 6 months after surgery. Urine flow rate and residual urine volume were measured before and at 1, 3, and 6 month after surgery. Preoperative and postoperative data were compared to determine the urodynamic changes. Measurements and Main Results: Of 422 patients, only 34 were lost to follow-up. The mean (SD) age of the remaining 388 patients was 57.6 (10.8) years, and parity was 1.87 (1.00). Compared with preoperative evaluation, there were significant changes in abdominal leak-point pressure and the urethral pressure profile including the maximal urethral pressure and the maximal urethral closure pressure at both 3 and 6 months postoperatively (p , .001). Insofar as urine flow rate and residual urine volume, statistical differences were observed at 1 month postoperatively but not at 3 and 6 months. Conclusion: These urodynamic findings suggest that patient storage and voiding functions are not substantially affected by the mid-urethral tape sling operation. Journal of Minimally Invasive Gynecology (2013) 20, 482–486 Ó 2013 AAGL. All rights reserved. Keywords:
DISCUSS
Genuine stress incontinence; Tension-free vaginal tape; TVT; TVT-O; Urodynamics
You can discuss this article with its authors and with other AAGL members at http://www.AAGL.org/jmig-20-3-JMIG-D-12-00631R1
Use your Smartphone to scan this QR code and connect to the discussion forum for this article now* * Download a free QR Code scanner by searching for ‘‘QR scanner’’ in your smartphone’s app store or app marketplace.
The mid-urethral theory was proposed by Petros and Ulmsten in 1990 [1], and in 1996, Ulmsten [2] introduced the tension-free vaginal tape (TVT) mid-urethral operation to treat stress urinary incontinence (SUI) in female patients. The TVT operation has become one of the most common The authors have no commercial, proprietary, or financial interest in the products or companies described in this article. Corresponding author: Zujun Fang, Department of Urology, Huashan Hospital, Fudan University, 12 Middle Urumqi Rd, Shanghai 200040, China. E-mail: [email protected] Submitted December 12, 2012. Accepted for publication February 3, 2013. Available at www.sciencedirect.com and www.jmig.org 1553-4650/$ - see front matter Ó 2013 AAGL. All rights reserved. http://dx.doi.org/10.1016/j.jmig.2013.02.002
procedures for treatment of SUI because it is easy to learn and is associated with high success and low complication rates. However, not enough research has been conducted to investigate preoperative and postoperative urodynamic findings. The objective of the present study was to understand the storage and voiding functions in our patients who underwent this procedure by focusing on urodynamics. Material and Methods Between September 2002 and December 2004, 110 female patients with SUI underwent TVT surgery at the Department of Urology of Huashan Hospital, an affiliate of Fudan University in Shanghai, China. These 110 patients
Zheng et al.
Urodynamics for TVT/TVT-O
and an additional 312 female patients who underwent tension-free vaginal tape–obturator (TVT-O) surgery between January 2005 and December 2011 were enrolled in the present study. The study was approved by the Huashan Institutional Review Board. All terminology used in this article conforms to the standards recommended by the International Continence Society or the Urodynamic Society [3–7]. All procedures were performed by experienced urologists and technicians, and data were interpreted by one observer to avert bias. Intervention A detailed medical history was obtained for every patient before physical examination. A 20-minute pad test was performed in every patient to determine the degree of urine leakage. In addition, urine flow rate, residual urine volume, and multi-channel urodynamics were measured in every patient before surgery. The mean and maximal flow rates and the voiding volume were recorded via uroflowmetry. The amount of residual urine was measured via ultrasonography. The multi-channel urodynamic study included both the bladder and urethral pressures during filling and voiding phases. A 3-way No. 7 flexible catheter (Laborie Medical Technologies Corp., Mississauga, ON, Canada) was used for multi-channel urodynamic study. The distal part of the catheter was fixed using adhesive tape at the perineum and inner thigh of the patient to prevent catheter movement during coughing. During the filling phase, patients were supine, with the head of the bed elevated to 30 degrees, and 30 C distilled water was infused at a rate of 20 mL/min. The volume of first sensation to void, the volume of strong desire to void, bladder compliance, stability of the bladder detrusor muscle, abdominal leak point pressure, and detrusor-sphincter synergy were recorded. To measure bladder pressure during the voiding phase, patients were in the sitting position. Detrusor pressure at the peak flow rate and detrusor-sphincter synergy were recorded. To measure urethral pressure, the filling rate of the distilled water was maintained at 2 mL/min, and the pulling rate was maintained at 6 cm/min. Maximum urethral pressure, maximum urethral closure pressure, and functional urethral length were recorded. After administration of lumbar anesthesia, patients were placed in the lithotomy position for the surgery. The tapes used in TVT and TVT-O procedures were obtained from Ethicon, Inc., Somerville, NJ. All procedures were performed by the same physicians (Z.F. and J.Z.) according to the manufacturer’s instructions. Absence of bladder perforation was confirmed via cystoscopy during TVT surgery. Tape tension was determined intraoperatively as follows: 250 to 300 mL distilled water was infused into the patient’s bladder. The operator’s fist was gently pressed against the suprapubic region of the patient to ensure that only a small amount of urine was voided. In this way, the tape tension did not need to be determined on the basis of the patient’s
483
cough response, and the procedure could be performed with the patient under general anesthesia. Of 422 patients, only 34 were excluded from the study. Ninety-nine patients underwent TVT surgery, and 289 patients underwent TVT-O surgery. The 20-minute pad test was performed and residual urine volume and urine flow rate were measured in all patients postoperatively at 1, 3, and 6 months after the operation. The multi-channel urodynamic study was performed at 3 and 6 months postoperatively. Because of loss to follow-up or incomplete follow-up, 34 patients were excluded. Statistical Analysis Unless otherwise indicated, all data are given as mean (SD). The Student t test was used for continuous variables, and the c2 test or Fisher exact test for continuous categorical variables. Repeated measures analysis of variance was used to analyze data pertaining to pad weight postoperatively because many numbers were zero. A p value of %.05 was considered statistically significant. All statistical analyses were performed using SPSS software (version 10.0; SPSS, Inc., Chicago, IL). Results Mean (SD) age of the 388 patients was 57.6 (10.8) years (range, 36–83 years), and parity was 1.87 (1.00) (range, 1–6). Of the 388 patients, 74.7% were postmenopausal. TVT surgery was performed in 99 patients, aged 56.7 (9.7) years and with parity of 1.66 (0.98). Of these patients, 73.7% were postmenopausal. TVT-O surgery was performed in 289 patients, aged 57.9 (10.1) years and with parity of 1.93 (1.01). Of these patients, 74.9% were postmenopausal. There was no statistical significance between groups in age, parity, and percentage of postmenopausal patients (Table 1). Mean (SD) preoperative pad weight was 93.7 (42.3) g (range, 23–287 g). At 1, 3, and 6 months after surgery, pad weight decreased to 1.4 (4.1), 1.2 (4.0), and 1.5 (4.3) g, respectively (p , .05). Stress incontinence resolved in 354 patients, and only 40 patients had minimal urine leakage, with a cure rate of 91.2%. In 93 of 99 patients who underwent TVT surgery and 261 of 289 patients who underwent TVT-O surgery, postoperative pad weight was 0 g. The Table 1 Patient characteristicsa Surgical procedure Variable
TVT
TVT-O
Age, yr Parity Postmenopausal status, No. (%)
56.7 (9.7) 57.9 (10.1) .31 1.66 (0.98) 1.93 (1.01) .11 73 (73.7) 216 (74.9) .45
TVT 5 transvaginal tape; TVT-O 5 transvaginal tape–obturator. a Unless otherwise indicated, values are given as mean (SD).
p value
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Journal of Minimally Invasive Gynecology, Vol 20, No 4, July/August 2013
cure rates for these 2 surgical procedures were 93.9% and 90.3%, respectively (p 5 .10). Insofar as complications, 4 patients (2.4%) had bladder perforation during the TVT surgery. One patient had urinary retention, and 1 had a pelvic hematoma (.5 cm in greatest diameter). Twenty-seven patients (7.0%) had urinary frequency and urgency at 1 month postoperatively. After pharmacotherapy, the symptoms improved by 3 or 6 months. Forty-two patients (14.5%) had discomfort in the inner thigh after the TVT-O surgery. There were no major complications such as wound infection, great vessel injury, or bowel perforation. The indwelling Foley catheter was retained postoperatively for a mean (SD) of 1.4 (1.1) days (range, 1–5 days). Bladder voiding function in the 388 patients who underwent surgical procedures is represented by the urodynamic parameters given in Table 2. Maximum and mean urine flow rates and residual urine volume were significantly different at 1 month postoperatively, as compared with preoperative values but not those measured at 3 and 6 months postoperatively. In addition, the postoperative detrusor pressure at the peak flow rate showed no statistical difference as compared with the preoperative measurement. No detrusorsphincter dyssynergia was noted in any patients during the voiding urodynamic study. Bladder storage function in the 388 patients is represented by the urodynamic parameters given in Table 2. Bladder volumes of first sensation and first urgency and bladder compliance showed no significant differences preoperatively as compared with the values obtained at 3 and 6 months postoperatively. However, there was statistical difference between the preoperative and postoperative abdominal leak-point pressure values. None of the patients was found
to have bladder detrusor instability or detrusor-sphincter dyssynergia. Urethral pressure profiles of the 388 patients is given in Table 2. The maximal urethral pressure and maximal urethral closure pressure were significantly higher at 3 and 6 months postoperatively as compared with preoperative values. However, there was no difference in functional urethral length. To compare TVT surgery with TVT-O surgery, the urodynamic parameters of voiding function and storage functions, as well as the urethral pressure profile, are given in Table 3. The only differences were observed in maximal urethral pressure, maximal urethral closure pressure, and abdominal leak-point pressure at both 3 and 6 months postoperatively. Discussion There has been much dispute about the urethral pressure profile before and after the mid-urethral tape sling operation. Lin et al [8] found that urethral function including maximum urethral pressure, maximum urethral closure pressure, and functional urethral length significantly improved after surgery. They suggested that the mechanism by which the TVT operation restores continence might be by reinforcing the urethropelvic ligament, which is believed to be one of the most important features of mid-urethral support. Other urologists [9] have found no change in urethral function after the operation. They believed that the tape could not compress the urethra during and after the operation, which is the theoretical basis of the TVT operation. However, our research has indicated that the urethral pressure profile, including maximum urethral pressure and maximum urethral closure pressure, increased significantly at 3 and 6 months
Table 2 Preoperative and postoperative comparison of urodynamic parametersa Postoperative Variable
Preoperative
1 month
p valueb
3 months
p valuec
6 months
p valued
Urine flow rate, mL/sec Mean Maximum Residual urine volume, mL Detrusor pressure at peak flow rate, cm H2O First sensation, mL First urgency, mL Bladder compliance Abdominal leak-point pressure, cm H2O Maximum urethral pressure, cm H2O Maximum urethral closure pressure, cm H2O Functional urethral length, cm
20.8 (6.1) 31.6 (9.0) 9.0 (14.3) 28.2 (6.5) 172.1 (31.6) 246.7 (52.0) 8.7 (2.7) 73.9 (14.0) 39.8 (10.4) 36.1 (9.9) 3.79 (0.24)
18.8 (6.5) 24.7 (7.3) 14.3 (32.8) NA NA NA NA NA NA NA NA
.005 ,.001 .02 NA NA NA NA NA NA NA NA
20.9 (6.1) 30.1 (8.2) 8.6 (14.9) 27.6 (6.2) 165.6 (32.4) 252.0 (48.7) 8.8 (2.9) 97.7 (16.3) 52.8 (9.9) 49.7 (9.8) 3.79 (0.24)
.90 .10 .65 .36 .06 .33 .84 ,.001 ,.001 ,.001 .87
20.6 (6.1) 31.3 (8.5) 9.2 (15.3) 28.1 (5.9) 171.2 (32.6) 252.4 (47.0) 8.8 (2.7) 98.3 (15.0) 51.7 (10.8) 49.8 (10.9) 3.80 (0.25)
.75 .77 .16 .90 .79 .29 .76 ,.001 ,.001 ,.001 .98
NA 5 not available. a Values are given as mean (SD). b Preoperatively vs 1 month postoperatively. c Preoperatively vs 3 months postoperatively. d Preoperatively vs 6 months postoperatively.
Zheng et al. Urodynamics for TVT/TVT-O
Table 3 Preoperative and postoperative comparison of urodynamic parameters between TVT and TVT-O proceduresa Postoperative 1 month
Preoperative Variable Urine flow rate, mL/sec Average Maximum Residual urine volume, mL Detrusor pressure at peak flow rate, cm H2O First sensation, mL First urgency, mL Bladder compliance (ml/cm H2O) Abdominal leak-point pressure, cm H2O Maximum urethral pressure, cm H2O Maximum urethral closure pressure, cm H2O Functional urethral length, cm
TVT
TVT-O
3 months
p valueb
TVT
TVT-O
p valueb
21.1 (6.1) 31.2 (8.5) 9.5 (14.8) 28.1 (6.7)
20.3 (6.1) 32.3 (9.6) 8.3 (13.6) 28.5 (6.4)
.36 .44 .54 .67
19.2 (6.8) 23.4 (5.7) 16.3 (40.3) NA
18.3 (6.0) 26.6 (8.8) 11.5 (16.7) NA
.43 .008 .34 NA
173.2 (32.8) 245.3 (52.1) 8.8 (2.7) 72.8 (13.7)
170.5 (29.9) 248.7 (51.9) 8.5 (2.7) 75.5 (14.3)
.59 .67 .40 .23
NA NA NA NA
NA NA NA NA
38.7 (10.7)
41.3 (9.9)
.11
NA
35.1 (9.5)
37.6 (10.4)
.11
3.79 (0.24)
3.80 (0.24)
.81
TVT
6 months TVT-O
p valueb
TVT
TVT-O
p valueb
21.2 (6.4) 29.7 (8.0) 10.2 (16.7) 27.5 (6.2)
20.3 (5.7) 30.6 (8.4) 6.3 (11.7) 27.8 (6.3)
.35 .47 .50 .78
20.6 (6.6) 31.1 (7.9) 9.4 (15.6) 28.0 (6.1)
20.6 (5.4) 31.7 (9.3) 8.8 (15.0) 28.4 (5.6)
.99 .67 .99 .69
NA NA NA NA
163.8 (31.0) 250.1 (50.1) 9.0 (3.0) 100.03 (15.8)
168.1 (34.3) 254.8 (46.7) 8.5 (2.6) 94.2 (16.5)
.40 .54 .32 .02
172.9 (33.0) 250.9 (48.9) 8.9 (2.7) 101.0 (15.0)
168.8 (32.0) 254.6 (44.4) 8.7 (2.7) 94.4 (14.2)
.43 .61 .71 .005
NA
NA
54.6 (10.1)
50.1 (9.0)
.004
53.6 (11.0)
48.9 (10.1)
.005
NA
NA
NA
51.4 (9.6)
47.3 (9.5)
.007
53.6 (10.8)
44.3 (8.5)
NA
NA
NA
3.78 (0.25)
.72
3.8 (0.25)
3.8 (0.24)
3.8 (0.23)
,.001 .96
NA 5 not available; TVT 5 transvaginal tape; TVT-O 5 transvaginal tape–obturator. a Values are given as mean (SD). b TVT vs TVT-O.
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Journal of Minimally Invasive Gynecology, Vol 20, No 4, July/August 2013
postoperatively. In addition, we found that urethral function improved to some extent, as indicated by the urethral parameters listed in Tables 2 and 3. Perhaps this was due to the local inflammatory reaction around the urethra, which would be expected to resolve progressively several months after surgery. Wang [10] found the same result as we did in that they also showed increased urethral function after the operation. Most urologists do not believe there would be any change in voiding function after the mid-urethral tape sling operation. However, others hold a different opinion and believe that the surgery might result in urine retention [11]. The present study has demonstrated that almost no patients had dysuria after the operation. Only 1 patient, who was also the first patient to undergo the TVT surgery, had urine retention at 1 week postoperatively. This might have been due to oppression of the urethra via tape that was too tight. We clipped the tape at 2 weeks postoperatively, and the patient had voluntary micturition. On the basis of the urodynamic parameters of voiding function in our research, we conclude that there were statistical differences in the maximal and mean urine flow rates as well as residual urine volume at 1 month postoperatively, as compared with preoperative values. However, these values improved significantly at 3 and 6 months postoperatively. McGuire and Savastano [12] attributed postoperative dysfunctional voiding to detrusor instability, in which a dyssynergic sphincter response occurred as a result of sudden unanticipated detrusor contractility. Only 27 patients in the present study had urinary urgency and frequency but exhibited no detrusor instability according to urodynamic findings. This could be due in part from how our patients were selected in that none had detrusor instability before surgery. Therefore, we believe the change in voiding function at 1 month postoperatively may have resulted from localized edema and inflammation around the urethra. To prove this hypothesis, voiding function in these patients was restored once the edema and inflammation subsided. Other than maximal urethral pressure, maximal urethral closure pressure, and abdominal leak-point pressure, we did not observe any difference in urodynamic parameters between TVT surgery and TVT-O surgery. In patients in both groups, age and parity were well matched, as was the percentage of postmenopausal women. In addition, both surgical procedures were performed by the same physicians with the patient under the same anesthesia. Thus, there was
definite comparability between the 2 types of surgeries. We believe the principle of these 2 operations contribute to the difference in urodynamic parameters. The objective of TVT surgery is to reinforce the urethropelvic ligament via ‘‘spot’’ suspension, thus creating higher pressure on the urethra. In contrast, TVT-O reinforces the ligament by forming a ‘‘bed,’’ and the pressure on the urethra is relatively lower. In conclusion, our urodynamic findings suggest that the mid-urethral tape sling operation does not substantially affect urine storage and voiding functions.
References 1. Petros PE, Ulmsten UI. An integral theory of female urinary incontinence: experimental and clinical considerations. Acta Obstet Gynecol Scand Suppl. 1990;153:7–31. 2. Ulmsten U. An ambulatory surgical procedure under local anesthesia for treatment of female urinary incontinence. Int Urogynecol J Pelvic Floor Dysfunct. 1996;7:81–85. discussion 85–86. 3. Abrams P, Blaivas JG, Stanton SL, et al. Sixth report on the standardization of terminology of lower urinary tract function: procedures related to neurophysiological investigation: electromyography, nerve conduction studies, reflex latencies, evoked potential and sensory testing. The International Continence Society Committee on Standardization of Terminology, New York, May 1985. Scand J Urol Nephrol. 1986;20:161–164. 4. Abrams P, Blaivas JG, Stanton SL, et al. Standardization of terminology of lower urinary tract function. Neurourol Urodyn. 1988;7:403–427. 5. Anderson JT, Blaivas JG, Cardozo L, Th€uroff J. Seventh report on the standardization of terminology of lower urinary tract function: lower urinary tract rehabilitation techniques. Int Urogynecol J. 1992;3:75–80. 6. Blaivas JG, Appell RA, Fantl JA, et al. Definition and classification of urinary incontinence: recommendation of the Urodynamic Society. Neurourol Urodyn. 1997;16:149–151. 7. Abrams P, Cardozo L, Fall M, et al. Standardization Sub-committee of the International Continence Society: The standardization of terminology of lower urinary tract function: report from the Standardization Sub-Committee of the International Continence Society. Neurourol Urodynam. 2002;21:167–178. 8. Lin LY, Sheu BC, Lin HH. Sequential assessment of urodynamic findings before and after tension-free vaginal tape (TVT) operation for female genuine stress incontinence. Eur Urol. 2004;45:362–366. 9. Lo TS, Wang AC, Horng SG, Liang CC, Soong YK. Ultrasonographic and urodynamic evaluation after tension free vaginal tape procedure (TVT). Acta Obstet Gynecol Scand. 2001;80:65–70. 10. Wang AC. An assessment of the early surgical outcome and urodynamic effects of the tension-free vaginal tape (TVT). Int Urogynecol J. 2000;11:282–284. 11. Salin A, Conquy S, Elie C, et al. Identification of risk factors for voiding dysfunction following TVT placement. Eur Urol. 2007;51:782–787. 12. McGuire EJ, Savastano JA. Urodynamic studies in enuresis and the nonneurogenic neurogenic bladder. J Urol. 1984;132:299–302.
Evaluation of Urodynamic Findings Before and After Mid-Urethral Tape Sling Operation for Female Stress Urinary Incontinence Jie Zheng, MD, Ke Xu, MD, Yaofei Sun, MD, Chuanyu Sun, MD, Qiang Ding, MD, and Zujun Fang, MD* From the Department of Urology, Huashan Hospital, Fudan University, Shanghai, China (all authors).
ABSTRACT Study Objective: To compare the urodynamic findings in female patients with stress urinary incontinence (SUI) before and after a mid-urethral tape sling operation. Design: Multi-channel urodynamic study (Canadian Task Force classification II-3). Setting: Department of Urology, Huashan Hospital, Shanghai, China. Patients: Women with SUI. Interventions: One hundred ten patients underwent tension-free vaginal tape (TVT) surgery from September 2002 to December 2004 and 312 patients underwent tension-free vaginal tape–obturator (TVT-O) surgery from January 2005 to December 2011. The study was performed in all patients before surgery and at 3 and 6 months after surgery. Urine flow rate and residual urine volume were measured before and at 1, 3, and 6 month after surgery. Preoperative and postoperative data were compared to determine the urodynamic changes. Measurements and Main Results: Of 422 patients, only 34 were lost to follow-up. The mean (SD) age of the remaining 388 patients was 57.6 (10.8) years, and parity was 1.87 (1.00). Compared with preoperative evaluation, there were significant changes in abdominal leak-point pressure and the urethral pressure profile including the maximal urethral pressure and the maximal urethral closure pressure at both 3 and 6 months postoperatively (p , .001). Insofar as urine flow rate and residual urine volume, statistical differences were observed at 1 month postoperatively but not at 3 and 6 months. Conclusion: These urodynamic findings suggest that patient storage and voiding functions are not substantially affected by the mid-urethral tape sling operation. Journal of Minimally Invasive Gynecology (2013) 20, 482–486 Ó 2013 AAGL. All rights reserved. Keywords:
DISCUSS
Genuine stress incontinence; Tension-free vaginal tape; TVT; TVT-O; Urodynamics
You can discuss this article with its authors and with other AAGL members at http://www.AAGL.org/jmig-20-3-JMIG-D-12-00631R1
Use your Smartphone to scan this QR code and connect to the discussion forum for this article now* * Download a free QR Code scanner by searching for ‘‘QR scanner’’ in your smartphone’s app store or app marketplace.
The mid-urethral theory was proposed by Petros and Ulmsten in 1990 [1], and in 1996, Ulmsten [2] introduced the tension-free vaginal tape (TVT) mid-urethral operation to treat stress urinary incontinence (SUI) in female patients. The TVT operation has become one of the most common The authors have no commercial, proprietary, or financial interest in the products or companies described in this article. Corresponding author: Zujun Fang, Department of Urology, Huashan Hospital, Fudan University, 12 Middle Urumqi Rd, Shanghai 200040, China. E-mail: [email protected] Submitted December 12, 2012. Accepted for publication February 3, 2013. Available at www.sciencedirect.com and www.jmig.org 1553-4650/$ - see front matter Ó 2013 AAGL. All rights reserved. http://dx.doi.org/10.1016/j.jmig.2013.02.002
procedures for treatment of SUI because it is easy to learn and is associated with high success and low complication rates. However, not enough research has been conducted to investigate preoperative and postoperative urodynamic findings. The objective of the present study was to understand the storage and voiding functions in our patients who underwent this procedure by focusing on urodynamics. Material and Methods Between September 2002 and December 2004, 110 female patients with SUI underwent TVT surgery at the Department of Urology of Huashan Hospital, an affiliate of Fudan University in Shanghai, China. These 110 patients
Zheng et al.
Urodynamics for TVT/TVT-O
and an additional 312 female patients who underwent tension-free vaginal tape–obturator (TVT-O) surgery between January 2005 and December 2011 were enrolled in the present study. The study was approved by the Huashan Institutional Review Board. All terminology used in this article conforms to the standards recommended by the International Continence Society or the Urodynamic Society [3–7]. All procedures were performed by experienced urologists and technicians, and data were interpreted by one observer to avert bias. Intervention A detailed medical history was obtained for every patient before physical examination. A 20-minute pad test was performed in every patient to determine the degree of urine leakage. In addition, urine flow rate, residual urine volume, and multi-channel urodynamics were measured in every patient before surgery. The mean and maximal flow rates and the voiding volume were recorded via uroflowmetry. The amount of residual urine was measured via ultrasonography. The multi-channel urodynamic study included both the bladder and urethral pressures during filling and voiding phases. A 3-way No. 7 flexible catheter (Laborie Medical Technologies Corp., Mississauga, ON, Canada) was used for multi-channel urodynamic study. The distal part of the catheter was fixed using adhesive tape at the perineum and inner thigh of the patient to prevent catheter movement during coughing. During the filling phase, patients were supine, with the head of the bed elevated to 30 degrees, and 30 C distilled water was infused at a rate of 20 mL/min. The volume of first sensation to void, the volume of strong desire to void, bladder compliance, stability of the bladder detrusor muscle, abdominal leak point pressure, and detrusor-sphincter synergy were recorded. To measure bladder pressure during the voiding phase, patients were in the sitting position. Detrusor pressure at the peak flow rate and detrusor-sphincter synergy were recorded. To measure urethral pressure, the filling rate of the distilled water was maintained at 2 mL/min, and the pulling rate was maintained at 6 cm/min. Maximum urethral pressure, maximum urethral closure pressure, and functional urethral length were recorded. After administration of lumbar anesthesia, patients were placed in the lithotomy position for the surgery. The tapes used in TVT and TVT-O procedures were obtained from Ethicon, Inc., Somerville, NJ. All procedures were performed by the same physicians (Z.F. and J.Z.) according to the manufacturer’s instructions. Absence of bladder perforation was confirmed via cystoscopy during TVT surgery. Tape tension was determined intraoperatively as follows: 250 to 300 mL distilled water was infused into the patient’s bladder. The operator’s fist was gently pressed against the suprapubic region of the patient to ensure that only a small amount of urine was voided. In this way, the tape tension did not need to be determined on the basis of the patient’s
483
cough response, and the procedure could be performed with the patient under general anesthesia. Of 422 patients, only 34 were excluded from the study. Ninety-nine patients underwent TVT surgery, and 289 patients underwent TVT-O surgery. The 20-minute pad test was performed and residual urine volume and urine flow rate were measured in all patients postoperatively at 1, 3, and 6 months after the operation. The multi-channel urodynamic study was performed at 3 and 6 months postoperatively. Because of loss to follow-up or incomplete follow-up, 34 patients were excluded. Statistical Analysis Unless otherwise indicated, all data are given as mean (SD). The Student t test was used for continuous variables, and the c2 test or Fisher exact test for continuous categorical variables. Repeated measures analysis of variance was used to analyze data pertaining to pad weight postoperatively because many numbers were zero. A p value of %.05 was considered statistically significant. All statistical analyses were performed using SPSS software (version 10.0; SPSS, Inc., Chicago, IL). Results Mean (SD) age of the 388 patients was 57.6 (10.8) years (range, 36–83 years), and parity was 1.87 (1.00) (range, 1–6). Of the 388 patients, 74.7% were postmenopausal. TVT surgery was performed in 99 patients, aged 56.7 (9.7) years and with parity of 1.66 (0.98). Of these patients, 73.7% were postmenopausal. TVT-O surgery was performed in 289 patients, aged 57.9 (10.1) years and with parity of 1.93 (1.01). Of these patients, 74.9% were postmenopausal. There was no statistical significance between groups in age, parity, and percentage of postmenopausal patients (Table 1). Mean (SD) preoperative pad weight was 93.7 (42.3) g (range, 23–287 g). At 1, 3, and 6 months after surgery, pad weight decreased to 1.4 (4.1), 1.2 (4.0), and 1.5 (4.3) g, respectively (p , .05). Stress incontinence resolved in 354 patients, and only 40 patients had minimal urine leakage, with a cure rate of 91.2%. In 93 of 99 patients who underwent TVT surgery and 261 of 289 patients who underwent TVT-O surgery, postoperative pad weight was 0 g. The Table 1 Patient characteristicsa Surgical procedure Variable
TVT
TVT-O
Age, yr Parity Postmenopausal status, No. (%)
56.7 (9.7) 57.9 (10.1) .31 1.66 (0.98) 1.93 (1.01) .11 73 (73.7) 216 (74.9) .45
TVT 5 transvaginal tape; TVT-O 5 transvaginal tape–obturator. a Unless otherwise indicated, values are given as mean (SD).
p value
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cure rates for these 2 surgical procedures were 93.9% and 90.3%, respectively (p 5 .10). Insofar as complications, 4 patients (2.4%) had bladder perforation during the TVT surgery. One patient had urinary retention, and 1 had a pelvic hematoma (.5 cm in greatest diameter). Twenty-seven patients (7.0%) had urinary frequency and urgency at 1 month postoperatively. After pharmacotherapy, the symptoms improved by 3 or 6 months. Forty-two patients (14.5%) had discomfort in the inner thigh after the TVT-O surgery. There were no major complications such as wound infection, great vessel injury, or bowel perforation. The indwelling Foley catheter was retained postoperatively for a mean (SD) of 1.4 (1.1) days (range, 1–5 days). Bladder voiding function in the 388 patients who underwent surgical procedures is represented by the urodynamic parameters given in Table 2. Maximum and mean urine flow rates and residual urine volume were significantly different at 1 month postoperatively, as compared with preoperative values but not those measured at 3 and 6 months postoperatively. In addition, the postoperative detrusor pressure at the peak flow rate showed no statistical difference as compared with the preoperative measurement. No detrusorsphincter dyssynergia was noted in any patients during the voiding urodynamic study. Bladder storage function in the 388 patients is represented by the urodynamic parameters given in Table 2. Bladder volumes of first sensation and first urgency and bladder compliance showed no significant differences preoperatively as compared with the values obtained at 3 and 6 months postoperatively. However, there was statistical difference between the preoperative and postoperative abdominal leak-point pressure values. None of the patients was found
to have bladder detrusor instability or detrusor-sphincter dyssynergia. Urethral pressure profiles of the 388 patients is given in Table 2. The maximal urethral pressure and maximal urethral closure pressure were significantly higher at 3 and 6 months postoperatively as compared with preoperative values. However, there was no difference in functional urethral length. To compare TVT surgery with TVT-O surgery, the urodynamic parameters of voiding function and storage functions, as well as the urethral pressure profile, are given in Table 3. The only differences were observed in maximal urethral pressure, maximal urethral closure pressure, and abdominal leak-point pressure at both 3 and 6 months postoperatively. Discussion There has been much dispute about the urethral pressure profile before and after the mid-urethral tape sling operation. Lin et al [8] found that urethral function including maximum urethral pressure, maximum urethral closure pressure, and functional urethral length significantly improved after surgery. They suggested that the mechanism by which the TVT operation restores continence might be by reinforcing the urethropelvic ligament, which is believed to be one of the most important features of mid-urethral support. Other urologists [9] have found no change in urethral function after the operation. They believed that the tape could not compress the urethra during and after the operation, which is the theoretical basis of the TVT operation. However, our research has indicated that the urethral pressure profile, including maximum urethral pressure and maximum urethral closure pressure, increased significantly at 3 and 6 months
Table 2 Preoperative and postoperative comparison of urodynamic parametersa Postoperative Variable
Preoperative
1 month
p valueb
3 months
p valuec
6 months
p valued
Urine flow rate, mL/sec Mean Maximum Residual urine volume, mL Detrusor pressure at peak flow rate, cm H2O First sensation, mL First urgency, mL Bladder compliance Abdominal leak-point pressure, cm H2O Maximum urethral pressure, cm H2O Maximum urethral closure pressure, cm H2O Functional urethral length, cm
20.8 (6.1) 31.6 (9.0) 9.0 (14.3) 28.2 (6.5) 172.1 (31.6) 246.7 (52.0) 8.7 (2.7) 73.9 (14.0) 39.8 (10.4) 36.1 (9.9) 3.79 (0.24)
18.8 (6.5) 24.7 (7.3) 14.3 (32.8) NA NA NA NA NA NA NA NA
.005 ,.001 .02 NA NA NA NA NA NA NA NA
20.9 (6.1) 30.1 (8.2) 8.6 (14.9) 27.6 (6.2) 165.6 (32.4) 252.0 (48.7) 8.8 (2.9) 97.7 (16.3) 52.8 (9.9) 49.7 (9.8) 3.79 (0.24)
.90 .10 .65 .36 .06 .33 .84 ,.001 ,.001 ,.001 .87
20.6 (6.1) 31.3 (8.5) 9.2 (15.3) 28.1 (5.9) 171.2 (32.6) 252.4 (47.0) 8.8 (2.7) 98.3 (15.0) 51.7 (10.8) 49.8 (10.9) 3.80 (0.25)
.75 .77 .16 .90 .79 .29 .76 ,.001 ,.001 ,.001 .98
NA 5 not available. a Values are given as mean (SD). b Preoperatively vs 1 month postoperatively. c Preoperatively vs 3 months postoperatively. d Preoperatively vs 6 months postoperatively.
Zheng et al. Urodynamics for TVT/TVT-O
Table 3 Preoperative and postoperative comparison of urodynamic parameters between TVT and TVT-O proceduresa Postoperative 1 month
Preoperative Variable Urine flow rate, mL/sec Average Maximum Residual urine volume, mL Detrusor pressure at peak flow rate, cm H2O First sensation, mL First urgency, mL Bladder compliance (ml/cm H2O) Abdominal leak-point pressure, cm H2O Maximum urethral pressure, cm H2O Maximum urethral closure pressure, cm H2O Functional urethral length, cm
TVT
TVT-O
3 months
p valueb
TVT
TVT-O
p valueb
21.1 (6.1) 31.2 (8.5) 9.5 (14.8) 28.1 (6.7)
20.3 (6.1) 32.3 (9.6) 8.3 (13.6) 28.5 (6.4)
.36 .44 .54 .67
19.2 (6.8) 23.4 (5.7) 16.3 (40.3) NA
18.3 (6.0) 26.6 (8.8) 11.5 (16.7) NA
.43 .008 .34 NA
173.2 (32.8) 245.3 (52.1) 8.8 (2.7) 72.8 (13.7)
170.5 (29.9) 248.7 (51.9) 8.5 (2.7) 75.5 (14.3)
.59 .67 .40 .23
NA NA NA NA
NA NA NA NA
38.7 (10.7)
41.3 (9.9)
.11
NA
35.1 (9.5)
37.6 (10.4)
.11
3.79 (0.24)
3.80 (0.24)
.81
TVT
6 months TVT-O
p valueb
TVT
TVT-O
p valueb
21.2 (6.4) 29.7 (8.0) 10.2 (16.7) 27.5 (6.2)
20.3 (5.7) 30.6 (8.4) 6.3 (11.7) 27.8 (6.3)
.35 .47 .50 .78
20.6 (6.6) 31.1 (7.9) 9.4 (15.6) 28.0 (6.1)
20.6 (5.4) 31.7 (9.3) 8.8 (15.0) 28.4 (5.6)
.99 .67 .99 .69
NA NA NA NA
163.8 (31.0) 250.1 (50.1) 9.0 (3.0) 100.03 (15.8)
168.1 (34.3) 254.8 (46.7) 8.5 (2.6) 94.2 (16.5)
.40 .54 .32 .02
172.9 (33.0) 250.9 (48.9) 8.9 (2.7) 101.0 (15.0)
168.8 (32.0) 254.6 (44.4) 8.7 (2.7) 94.4 (14.2)
.43 .61 .71 .005
NA
NA
54.6 (10.1)
50.1 (9.0)
.004
53.6 (11.0)
48.9 (10.1)
.005
NA
NA
NA
51.4 (9.6)
47.3 (9.5)
.007
53.6 (10.8)
44.3 (8.5)
NA
NA
NA
3.78 (0.25)
.72
3.8 (0.25)
3.8 (0.24)
3.8 (0.23)
,.001 .96
NA 5 not available; TVT 5 transvaginal tape; TVT-O 5 transvaginal tape–obturator. a Values are given as mean (SD). b TVT vs TVT-O.
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postoperatively. In addition, we found that urethral function improved to some extent, as indicated by the urethral parameters listed in Tables 2 and 3. Perhaps this was due to the local inflammatory reaction around the urethra, which would be expected to resolve progressively several months after surgery. Wang [10] found the same result as we did in that they also showed increased urethral function after the operation. Most urologists do not believe there would be any change in voiding function after the mid-urethral tape sling operation. However, others hold a different opinion and believe that the surgery might result in urine retention [11]. The present study has demonstrated that almost no patients had dysuria after the operation. Only 1 patient, who was also the first patient to undergo the TVT surgery, had urine retention at 1 week postoperatively. This might have been due to oppression of the urethra via tape that was too tight. We clipped the tape at 2 weeks postoperatively, and the patient had voluntary micturition. On the basis of the urodynamic parameters of voiding function in our research, we conclude that there were statistical differences in the maximal and mean urine flow rates as well as residual urine volume at 1 month postoperatively, as compared with preoperative values. However, these values improved significantly at 3 and 6 months postoperatively. McGuire and Savastano [12] attributed postoperative dysfunctional voiding to detrusor instability, in which a dyssynergic sphincter response occurred as a result of sudden unanticipated detrusor contractility. Only 27 patients in the present study had urinary urgency and frequency but exhibited no detrusor instability according to urodynamic findings. This could be due in part from how our patients were selected in that none had detrusor instability before surgery. Therefore, we believe the change in voiding function at 1 month postoperatively may have resulted from localized edema and inflammation around the urethra. To prove this hypothesis, voiding function in these patients was restored once the edema and inflammation subsided. Other than maximal urethral pressure, maximal urethral closure pressure, and abdominal leak-point pressure, we did not observe any difference in urodynamic parameters between TVT surgery and TVT-O surgery. In patients in both groups, age and parity were well matched, as was the percentage of postmenopausal women. In addition, both surgical procedures were performed by the same physicians with the patient under the same anesthesia. Thus, there was
definite comparability between the 2 types of surgeries. We believe the principle of these 2 operations contribute to the difference in urodynamic parameters. The objective of TVT surgery is to reinforce the urethropelvic ligament via ‘‘spot’’ suspension, thus creating higher pressure on the urethra. In contrast, TVT-O reinforces the ligament by forming a ‘‘bed,’’ and the pressure on the urethra is relatively lower. In conclusion, our urodynamic findings suggest that the mid-urethral tape sling operation does not substantially affect urine storage and voiding functions.
References 1. Petros PE, Ulmsten UI. An integral theory of female urinary incontinence: experimental and clinical considerations. Acta Obstet Gynecol Scand Suppl. 1990;153:7–31. 2. Ulmsten U. An ambulatory surgical procedure under local anesthesia for treatment of female urinary incontinence. Int Urogynecol J Pelvic Floor Dysfunct. 1996;7:81–85. discussion 85–86. 3. Abrams P, Blaivas JG, Stanton SL, et al. Sixth report on the standardization of terminology of lower urinary tract function: procedures related to neurophysiological investigation: electromyography, nerve conduction studies, reflex latencies, evoked potential and sensory testing. The International Continence Society Committee on Standardization of Terminology, New York, May 1985. Scand J Urol Nephrol. 1986;20:161–164. 4. Abrams P, Blaivas JG, Stanton SL, et al. Standardization of terminology of lower urinary tract function. Neurourol Urodyn. 1988;7:403–427. 5. Anderson JT, Blaivas JG, Cardozo L, Th€uroff J. Seventh report on the standardization of terminology of lower urinary tract function: lower urinary tract rehabilitation techniques. Int Urogynecol J. 1992;3:75–80. 6. Blaivas JG, Appell RA, Fantl JA, et al. Definition and classification of urinary incontinence: recommendation of the Urodynamic Society. Neurourol Urodyn. 1997;16:149–151. 7. Abrams P, Cardozo L, Fall M, et al. Standardization Sub-committee of the International Continence Society: The standardization of terminology of lower urinary tract function: report from the Standardization Sub-Committee of the International Continence Society. Neurourol Urodynam. 2002;21:167–178. 8. Lin LY, Sheu BC, Lin HH. Sequential assessment of urodynamic findings before and after tension-free vaginal tape (TVT) operation for female genuine stress incontinence. Eur Urol. 2004;45:362–366. 9. Lo TS, Wang AC, Horng SG, Liang CC, Soong YK. Ultrasonographic and urodynamic evaluation after tension free vaginal tape procedure (TVT). Acta Obstet Gynecol Scand. 2001;80:65–70. 10. Wang AC. An assessment of the early surgical outcome and urodynamic effects of the tension-free vaginal tape (TVT). Int Urogynecol J. 2000;11:282–284. 11. Salin A, Conquy S, Elie C, et al. Identification of risk factors for voiding dysfunction following TVT placement. Eur Urol. 2007;51:782–787. 12. McGuire EJ, Savastano JA. Urodynamic studies in enuresis and the nonneurogenic neurogenic bladder. J Urol. 1984;132:299–302.