Incidence and Risk Factors of Postoperative De Novo Voiding Dysfunction following Midurethral Sling Procedures Hoon Ah Jang, Jae Hyun Bae, Jeong Gu Lee From the Department of Urology, College of Medicine, Korea University, Seoul, Korea
Purpose: To compare the incidence of postoperative de novo voiding dysfunction and to identify the risk factors affecting the development of de novo voiding dysfunction after various midurethral sling (MUS) procedures for female stress urinary incontinence (SUI). Materials and Methods: Women with SUI underwent MUS by various Ⓡ procedures [tension-free vaginal tape (TVT ), tension-free vaginal tape Ⓡ Ⓡ Ⓡ obturator (TVTO ), tension-free obturator tape (TOT ), or TVT-secure ]. Cases were reviewed retrospectively with follow-up of at least 6 months. The subjects were divided into 2 groups according to the presence of postoperative de novo voiding dysfunction. De novo voiding dysfunction was defined as a low maximal uroflow rate (Qmax＜15 ml/s) or a large post-voided residual urine volume (PVR＞100 ml) observed at 6 months postoperatively. Clinical and urodynamic parameters were compared between the voiding dysfunction (Group I) and normal voiding (Group II) groups according to MUS procedure. Results: Of the 625 subjects, 163 (26%) patients showed evidence of de novo voiding dysfunction (Group I). Of these 163 subjects, 12 (7.3%) patients complained of voiding symptoms. There was no difference in the incidence of de novo voiding dysfunction according to MUS procedure. Multivariate analysis showed Qmax to be the only independent risk factor for de novo voiding dysfunction. Conclusions: This study confirmed the considerable incidence of postoperative de novo voiding dysfunction, which is, however, mostly asymptomatic. As preoperative Qmax decreased, the chance of postoperative de novo voiding dysfunction increased. Identification of risk factors of voiding dysfunction in women undergoing MUS may help in planning for better follow-up and early detection of possibly inherent late complications of voiding dysfunction. (Korean J Urol 2009;50:762-766) Key Words: Urinary bladder, Complications
Korean Journal of Urology Vol. 50 No. 8: 762-766, August 2009 DOI: 10.4111/kju.2009.50.8.762
Received：April 15, 2009 Accepted：July 22, 2009 Correspondence to: Jeong Gu Lee Department of Urology, Korea University Anam Hospital, 126-1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-705, Korea TEL: 02-920-5683 FAX: 02-928-7864 E-mail:
[email protected] Ⓒ The Korean Urological Association, 2009
introduced to reduce complications such as bladder perforation.5
INTRODUCTION
In MUS, the sling provides dynamic kinking of the urethra The midurethral sling (MUS) procedure became one of the
when abdominal pressures increase but not at the resting phase.
standard minimally invasive procedures used to treat stress
Thus, theoretically, MUS does not cause voiding dysfunction
Ⓡ
urinary incontinence (SUI) since tension-free vaginal tape (TVT )
such as weak stream, urinary hesitancy, and straining voiding
was first described in 1996 by Ulmsten.1-4 Shortly thereafter,
in itself. However, voiding dysfunction such as a decreased
a different method of tape insertion was described, in which
maximal uroflow rate (Qmax) or increased post-voided residual
the tape passes through the obturator foramen (transobturator
urine volume (PVR) has been reported after the MUS opera-
Ⓡ
tion.3,6
tape, or TOT ). Several variations of this method have been
762
Hoon Ah Jang, et al：Incidence and Risk Factors of Postop. Voiding Dysfunction following MUS
763
Although a standard definition of female voiding dysfunction
voiding diary, Bristol female lower urinary tract symptom
is controversial,7 Qmax, PVR, and voiding time are used as
(LUTS) questionnaire (BF-LUTS), and urodynamic studies
3,8,9
criteria for voiding dysfunction.
including Qmax, PVR, and detrusor pressure at the maximum
The incidence of voiding dysfunction after MUS has been
flow rate (Pdetmax). Preoperative SUI symptoms were classi-
reported to be between 4% and 55% and it may affect the
fied by Stamey grade.15
patient’s well-being and quality of life (QoL), consequently
Postoperative evaluation was done at 3 and 6 months after
2,3,10
decreasing patient satisfaction with the procedure.
the MUS procedure. All patients were followed up with voiding
Postoperative voiding dysfunction can be self-limiting if
symptom history, physical examination, uroflowmetry, voiding
1,11
diary, and a validated questionnaire to assess the patient’s
However, in some severe cases, unavoidable removal or
perception of the results of and satisfaction with the surgery.
urinary symptoms do not exist and the PVR is adequate. 12,13
The incidence and
Cure of SUI was defined as complete dry and improvement as
risk factors of de novo voiding dysfunction after the MUS
still urine leakage but no treatment required or patient satisfied
procedure in patients with normal voiding function preopera-
with the results of the operation. Cure and improvement were
tively have yet to be evaluated. The aim of the present study
regarded as successful treatment of SUI.
was therefore to evaluate the incidence and risk factors of de
Independent-sample t-tests and Pearson's chi-square test were
novo voiding dysfunction after the MUS procedure and to
used to test the statistical significance of differences between
compare these according to type of MUS device.
patients with and without postoperative voiding dysfunction.
relaxation of the mesh has been reported.
Logistic regression analysis was used to explore the risk factors
MATERIALS AND METHODS
of postoperative Qmax decrease. Statistical significance was considered at p＜0.05.
Between 2004 and 2008, the medical records of patients who
underwent MUS for treatment of SUI utilizing various
RESULTS
procedures (TVTⓇ, TVTOⓇ, TOTⓇ, and TVT-secureⓇ) with at least 6 months of follow-up were reviewed retrospectively.
A total of 631 patients underwent the MUS procedure during
To exclude preoperative voiding difficulties overlapping the
this period. Among them, 4 patients with a preoperative Qmax
criteria of de novo voiding dysfunction, patients with pre-
＜15 ml/s and 2 patients with postoperative urinary retention
operative Qmax less than 15 ml/s or PVR＞100 ml were
were excluded. The analysis was therefore based on 625
excluded. Patients who showed an obstructive pattern on
patients.
preoperative uroflowmetry or who had postoperative retention
Bladder perforation occurred in 2 patients, which was treated
were also excluded from the study.
with urethral catheterization. The urethral catheter was removed
Voiding dysfunction after MUS was defined when more than
after confirmation of no urine leakage on a cystogram after 1
one of the following was observed: 1) de novo postoperative
week.
voiding symptoms (such as frequency, weak stream, voiding
The mean age of the study population was 51.6 (range,
difficulty, and residual sensation), 2) obstructive pattern on
31-96) years and parity was 2.5 (range, 0-9). The mean duration
uroflowmetry, 3) postoperative Qmax＜15 ml/s, 4) residual
of follow-up was 7.4±3.6 (range, 6-9) months. Of the 625
urine volume＞100 ml. The study population was divided into
patients, 204 had grade I, 405 had grade II, and 16 had grade
2 groups, one with postoperative de novo voiding dysfunction
III SUI.
(group 1) and the other with normal voiding after MUS (group
Coexistent cystocele and rectocele were observed in 310 and
2). The criterion of Qmax＜15 ml/s as a cutoff value for
37 patients, respectively. The mean Valsalva leak point pressure
voiding dysfunction was based on the female voiding dys-
(VLPP) was 62.7±29.1 cmH2O. Postoperatively, 474 (76.1%)
function guideline published by the Korean Continence So-
patients were cured and 133 (21.2%) were improved. There
ciety.14
were no statistically significant differences in surgical outcomes
Preoperative evaluation of all patients included age, history
according to symptom grade (Stamey grade), cystocele, VLPP,
taking, physical examination, body mass index (BMI), parity,
previous pelvic operation, concomitant vaginal operations, or
764
Korean Journal of Urology vol. 50, 762-766, August 2009
Table 1. Comparisons of demographic data between the postoperative voiding dysfunction group (Group 1) and the normal voiding group (Group 2)
No. of patients Age (years) Body mass index Diabetes mellitus (＋) Parity (number of birth) Stamey sx grade (I/II/III) Cystocele (I/II/III/IV) Rectocele Surgical methods TVT TVTO TOT TVT-secure Preoperative Qmax (ml/sec) Voided volme (ml) Postvoid, residual (ml) Pdetmax (mmHg) Delta Qmax (ml/sec)
Total patients
Group 1
Group 2
p-value
625 51.6±9.4 25.1±3.2 34 (5.4%) 2.5±1.6 204/405/16 207/79/19/5 37
163 51.2±9.3 25.1±3.2 8 (7.5%) 2.5±1.1 38/64/5 36/22/5/2 9
462 53.1±9.9 25.2±3.4 26 (5.0%) 2.6±1.2 166/341/11 171/57/14/3 28
0.124 0.810a 0.829b 0.639b 0.843b 0.721b 0.562b
245 128 115 131
52 32 21 23
193 96 94 108
0.294
25.2±10.2 268.5±132.9 20.7±43.7 20.5±12.2 −4.9±6.55
＜0.001a 0.172a 0.922a 0.416a ＜0.001a,c
21.3±11.7 249.0±129.2 30.3±34.9 21.7±14.4 −11.79±6.65
a
TVT: tension-free vaginal tape, TVTO: tension-free vaginal tape obturator, TOT: tension-free obturator tape, Qmax: maximal uroflow rate, Delta Qmax: postoperative Qmax-preoperative Qmax, a: independent-sample t-test, b: Pearson's chi-square test, c: paired t-test
different kinds of tape devices.
0.294; 21.3±11.7 ml/s in group 1 and 25.2±10.2 ml/s in group
Postoperative voiding dysfunction was observed in 156
2, respectively) (Table 1). The other variables such as surgical
patients, in whom only 12 patients presented with obvious
methods, age, BMI, parity, DM, cystocele, and urodynamic
voiding symptoms. Of the 12 patients with voiding symptoms,
variables did not differ significantly between groups. The mean
3 complained of weak stream, 2 of residual urinary sensations,
change in Qmax (postoperative Qmax-preoperative Qmax) was
and 7 of frequency. Of these 12, 5 patients has a Qmax＜15
significantly greater in group 1 than in group 2.
ml/s or PVR＞100 ml. All 3 with weak stream had a Qmax
To explore the risk factors for postoperative de novo voiding
＜15 ml/s with PVR＞100 ml. Two patients with residual
dysfunction, multiple logistic regression was performed and
urinary sensation had a Qmax＜15 ml/s. Among the 18 patients
preoperative Qmax was found to be the only risk factor. As
with PVR＞100 ml, 7 patients had PVR＞200 ml, requiring
the preoperative Qmax increased by 1 ml/s, the risk of
intermittent catheterization. One of them presented with a large
postoperative voiding dysfunction decreased by a factor of 0.95
amount (308 ml) of PVR and was treated with postvoid
(Table 2). The other variables such as age, BMI, and parity did
catheterization without symptom improvement; therefore, the
not show statistical differences in the multiple regression
tape was released at 5 months after the MUS procedure.
analysis.
Meanwhile, 132 patients in whom postoperative Qmax
decreased to ＜15 ml/s showed no voiding symptoms, and
DISCUSSION
among these, only 9 patients presented with residual urine volume over 100 ml.
MUS is the single most common surgical modality for the
In the comparative analysis of preoperative parameters
treatment of SUI, with good results and few complications. In
between the normal voiding group (group 2) and the voiding
MUS, the sling provides dynamic kinking of the urethra when
dysfunction group (group 1) postoperatively, preoperative
abdominal pressures increase, while maintaining stability at the
Qmax was significantly lower in group 1 than in group 2 (p=
resting phase, consequently preventing urinary incontinence.
16
Hoon Ah Jang, et al：Incidence and Risk Factors of Postop. Voiding Dysfunction following MUS
Table 2. Analysis of risk factors for postoperative voiding dysfunction after midurethral sling
Age Height Weight Body mass index Parity Diabetes mellitus Symptom duration Cystocele 1 2 3 4 Symptom grade 1 2 3 Preoperative Qmax (ml/sec) Postvoid, residual (ml) Pdetmax (mmHg)
a
765
ml/s to 20-25 ml/s after the TVT procedure. Sander et al18 also reported decreased Qmax, increased PVR, and obstructive
OR
95% CI
p-value
pattern of uroflow after TVT. But less than half of those
1.012 1.107 0.901 0.803 0.987 0.908 0.998
50.90-52.37 15.21-16.06 60.90-62.11 24.89-25.40 2.33-2.50
0.518 0.582 0.700 0.754 0.831 0.601 0.321
patients showed symptoms of voiding dysfunction postopera-
49.57-59.26
0.776 1.454 0.862 1.103
0.814 1.459 0.834 0.993
tively. In our study, a low Qmax preoperatively was shown as a risk factor of de novo postoperative voiding dysfunction, whereas the individual decreased range of Qmax after the MUS procedure was greater in the de novo voiding dysfunction group than in the normal voiding group. Saline et al3 reported that 20% of patients presented with decreased Qmax of less than 15 ml/s and risk factors for decreased Qmax were age and preoperative low Qmax, which was comparable to our results. Taken together, the above results indicate that a low preoperative Qmax is a risk factor for postoperative presence of voiding
0.091 0.546
0.688 0.650
0.95 1.00 0.985
23.73-25.0 17.48-24.11 21.45-22.72
＜0.001 1.000 0.985
OR: odds ratio, CI: confidence interval, Qmax: maximal uroflow a rate, : logistic regression analysis
dysfunction. Decrease of Qmax postoperatively may also occur in patients with low Pdetmax or bladder outlet obstruction. However, in our study, there was no difference in the preoperative Pdetmax between groups, suggesting that the postoperative decrease of Qmax was not affected by preoperative low Pdetmax or bladder outlet obstruction. On the other hand, Wang et al17 defined voiding dysfunction as PVR above 100 ml and low preoperative Qmax and reported that postoperative urinary
Thus, theoretically, MUS doesn’t cause voiding dysfunction
infection was one of the risk factors of postoperative voiding
including weak stream, urinary hesitancy, or straining voiding.
dysfunction.
Clinical risk may not be significant in the case of decreased
In our study, only a small portion of the patients with
Qmax after MUS if the patient does not have voiding symp-
objective de novo voiding dysfunction (Qmax＜15 ml/s or PVR
toms and has an acceptable PVR. However, considering the
＞100 ml) were symptomatic. These findings indicated that the
possible long-term consequences on the bladder and upper
significant changes in objective clinical parameters such as
urinary tract, even if patients do not present voiding symptoms,
Qmax or PVR did not overlap with the symptoms the patients
a decrease in Qmax should be carefully monitored. The
felt, indicating the necessity to identify patients with potential
incidence of voiding dysfunction after the MUS procedure has
postoperative voiding dysfunction by regular uroflowmetry and
2,3,10
been reported to be from 4% to 55%.
Also, changes in the
PVR measurement, especially in high-risk groups.
postoperative emptying phase, such as a decrease of Qmax,
According to other reports on the incidence of postoperative
obstructive pattern on uroflowmetry, and increase of PVR have
de novo voiding dysfunction according to MUS procedure,
been reported.7,17,18 It is commonly agreed that MUS com-
Daneshgari et al21 found no differences according to the method
presses the midurethra, thus affecting voiding during the
of inserting the tape. Latthe et al22 also reported the same
emptying phase.
conclusion, with findings similar to ours. The method used to
Our study showed the cure and improvement rate of SUI to
insert the tape did not seem to affect the development of
be 76.1% and 21.4%, respectively, which is similar to the
postoperative voiding dysfunction.
19,20
In our study, postoperative evalua-
To summarize, our findings indicate that with a lower
tion was performed at least 6 months after the MUS procedure.
preoperative Qmax, the incidence of postoperative voiding
Qmax was significantly decreased postoperatively, but the
dysfunction became higher. In women with low preoperative
voided volume and PVR showed no significant changes.
Qmax, a longer-term, regular follow-up should be recom-
results of other studies.
6
Boustead and Singh reported a decrease in Qmax from 30-35
mended to minimize the possible adverse consequences caused
766
Korean Journal of Urology vol. 50, 762-766, August 2009
by de novo voiding dysfunction.
CONCLUSIONS In our study, a considerable rate of postoperative de novo
10.
11.
voiding dysfunction, although mostly asymptomatic, did exist. Preoperative peak flow rate was regarded as the only risk factor for postoperative de novo voiding dysfunction. There were no differences in the incidence according to method of MUS. In
12.
patients with low preoperative Qmax, the MUS procedure should be performed carefully, considering the potential for
13.
postoperative de novo voiding dysfunction.
REFERENCES 1. Ulmsten U, Henriksson L, Johnson P, Varhos G. An ambulatory surgical procedure under local anesthesia for treatment of female urinary incontinence. Int Urogynecol J Pelvic Floor Dysfunct 1996;7:81-5 2. Novara G, Galfano A, Boscolo-Berto R, Secco S, Cavalleri S, Ficarra V, et al. Complication rates of tension-free midurethral slings in the treatment of female stress urinary incontinence: a systematic review and meta-analysis of randomized controlled trials comparing tension-free midurethral tapes to other surgical procedures and different devices. Eur Urol 2008;53: 288-308 3. Salin A, Conquy S, Elie C, Touboul C, Parra J, Zerbib M, et al. Identification of risk factors for voiding dysfunction following TVT placement. Eur Urol 2007;51:782-7 4. Kim NS, Bae JH, Lee JG. Long-term follow-up of the tension-free vaginal tape (TVT) procedure for treating female stress urinary incontinence. Korean J Urol 2006;47:729-33 5. Koh JS, Kim HS, Kim HW, Lee YS, Kim SI, Lee KS, et al. Comparison of secondary procedures for recurrent stress urinary incontinence after a transobturator tape procedure: shortening of the tape versus tension-free vaginal tape redo. Korean J Urol 2007;48:1149-54 6. Boustead GB, Singh S. Outcome of TVT sling procedure in a single UK institution. BJU Int 2000;86(Suppl 3):77 7. Olujide LO, O'Sullivan SM. Female voiding dysfunction. Best Pract Res Clin Obstet Gynaecol 2005;19:807-28 8. Hong B, Park S, Kim HS, Choo MS. Factors predictive of urinary retention after a tension-free vaginal tape procedure for female stress urinary incontinence. J Urol 2003;170:852-6 9. Sokol AI, Jelovsek JE, Walters MD, Paraiso MF, Barber MD. Incidence and predictors of prolonged urinary retention after
14.
15.
16.
17.
18.
19.
20.
21.
22.
TVT with and without concurrent prolapse surgery. Am J Obstet Gynecol 2005;192:1537-43 Kuuva N, Nilsson CG. A nationwide analysis of complications associated with the tension-free vaginal tape (TVT) procedure. Acta Obstet Gynecol Scand 2002;81:72-7 Ulmsten U, Johnson P, Rezapour M. A three-year follow up of tension free vaginal tape for surgical treatment of female stress urinary incontinence. Br J Obstet Gynaecol 1999;106: 345-50 Klutke C, Siegel S, Carlin B, Paszkiewicz E, Kirkemo A, Klutke J. Urinary retention after tension-free vaginal tape procedure: incidence and treatment. Urology 2001;58:697-701 Meschia M, Pifarotti P, Bernasconi F, Guercio E, Maffiolini M, Magatti F, et al. Tension-free vaginal tape: analysis of outcomes and complications in 404 stress incontinent women. Int Urogynecol J Pelvic Floor Dysfunct 2001;12(Suppl 2): S24-7 Lee JG, Choo MS, Lee KS, Yoo TK, Seo JT, Kim JC. Female voiding dysfunction treatment guideline. Female voiding dysfunction treatment guideline 2008. 2008;13 Stamey TA. Endoscopic suspension of the vesical neck for urinary incontinence in females. Report on 203 consecutive patients. Ann Surg 1980;192:465-71 Choi H, Lee JG. Preoperative factors affecting postoperative voiding difficulty after tension-free vaginal tape (TVT) operation. Korean J Urol 2004;45:982-7 Wang KH, Wang KH, Neimark M, Davila GW. Voiding dysfunction following TVT procedure. Int Urogynecol J Pelvic Floor Dysfunct 2002;13:353-7 Sander P, Moller LM, Rudnicki PM, Lose G. Does the tension-free vaginal tape procedure affect the voiding phase? Pressure-flow studies before and 1 year after surgery. BJU Int 2002;89:694-8 Richter HE, Norman AM, Burgio KL, Goode PS, Wright KC, Benton J, et al. Tension-free vaginal tape: a prospective subjective and objective outcome analysis. Int Urogynecol J Pelvic Floor Dysfunct 2005;16:109-13 Andonian S, Chen T, St-Denis B, Corcos J. Randomized clinical trial comparing suprapubic arch sling (SPARC) and tension-free vaginal tape (TVT): one-year results. Eur Urol 2005;47:537-41 Daneshgari F, Kong W, Swartz M. Complications of mid urethral slings: important outcomes for future clinical trials. J Urol 2008;180:1890-7 Latthe PM, Foon R, Toozs-Hobson P. Transobturator and retropubic tape procedures in stress urinary incontinence: a systematic review and meta-analysis of effectiveness and complications. BJOG 2007;114:522-31
