International Urology and Nephrology 24 (1), pp. 49--53 (1992)
Development of Urethral Stricture after Transurethral Prostatectomy: A Retrospective Study M. D. BALBAY, A. ERGEN, A. SAHIN, M. LEKILI,
S. ULUCAY, E. KARAA~AOt3LU* Department of Urology, Hacettepe University Hospital; *Department of Biostatistics, Hacettepe University Medical Faculty, Ankara, Turkey (Accepted March 28, 1991) A total of 103 patients who were diagnosed to have benign prostatic hyperplasia (BPH) without preoperative urethral stricture and underwent transurethral prostatectomy (TURP) were evaluated retrospectively from patient charts. The incidence of urethral stricture development was calculated as 11.65% (12 out of 103 patients). Among the aetiologic factors analyzed, the most important ones appeared to be postoperative refection, age of the patient, duration of postoperative catheterization and histology of the disease, in the order of significance in the development of urethral stricture after TURP.
Introduction
Urethral stricture is not an u n c o m m o n complication of transurethral prostatectomy (TURP). The incidence of urethral stricture development after T U R P has been reported in the literature as 4-29 % [1, 2]. Although not known precisely, some factors such as age and race of the patient, the material and calibre of the catheters used, resection time, presence of urinary infection, disproportion between the size of resectoscope sheet and diameter of the urethra, experience of the surgeon have all been suspected to play a role in urethral stricture development after T U R P [3, 4]. It was claimed that preoperative internal urethrotomy prevents stricture development [5] and urinary infection should be treated vigorously [3]. In this study we investigated the incidence of urethral strictures among patients who underwent T U R P for BPH at our hospital, and evaluated the following risk factors : patient age, resection time, amount of tissue resected, duration of preoperative and postoperative catheterizations, preoperative and postoperative urinary infections and histology of disease, which were suspected to have a role in urethral stricture development.
4
VSP, Utrecht Akaddmiai Kiad6, Budapest
50
Balbay et aL : Urethral stricture after T U R P
Material and methods
One hundred and three BPH patients, aged 45 to 96 years, who underwent T U R P between 1987 and 1989 at the Department of Urology, Hacettepe University Hospital, were included in the study. They were evaluated at 6 to 12 months after operation. All patients were diagnosed to have BPH without urethral stricture. Urine cultures were taken from each patient during both the preoperative and the postoperative period. Any growth more than 105 colonies/ml in urine culture was accepted as urinary infection. All patients underwent T U R P with a 28 F Storz resectoscope under appropriate antibiotic coverage. Patients who had negative urine cultures were given an antibiotic prophylaxis with trimethoprim sulfametoxazole. Distilled water was used as irrigation fluid at operation and a 22 F Latex urethral catheter was inserted into the bladder transurethrally, the balloon of which was inflated with 30 or 35 cc of distilled water after completion of the operation. At the postoperative follow-up, patients who complained of a weak stream on urination were suspected to have urethral stricture and were examined endoscopically. When a urethral stricture was diagnosed, internal urethrotomy was performed with a Storz internal urethrotome at the same time. Patient charts were reviewed retrospectively. Two groups were formed according to urethral stricture development after TURP. For each patient in each group, age, operation time, amount of tissue resected, duration of preoperative and postoperative catheterizations, presence of preoperative and postoperative infections, as well as histologic diagnosis of the disease were documented for evaluation as risk factors. The risk factors in the development of urethral stricture after T U R P were analyzed by multivariate logistic regression and Odds Ratios (O.R.).
Results
Out of 103 patients, 12 (11.65 %) were diagnosed to have urethral stricture postoperatively. The distribution of strictures along the urethra is shown in Table 1. One patient who had two strictures - one of which was at the external meatus, and the other at the membranous urethra - is shown as multiple strictures in Table 1. We found that the most common site of stricture development after T U R P was the membranous urethra. Thirty-three out of 91 patients without urethral stricture (36.26 %) and 3 out of 12 patients with urethral stricture (25 %) had preoperative urinary infections, while 14 out of 91 patients without urethral stricture (15.38%) and 7 out of 12 patients with urethral stricture (58.33 %) had urinary infection postoperatively. Among patients without stricture 5 out of 91 (5.49 %), and with stricture 2 out of 12 (16.66 %) were diagnosed to have prostatic adenocarcinoma and the International Uroloyy and Nephroloyy 24, 1992
51
Balbay et aL: Urethral stricture after T U R P
remaining patients in both groups as BPH by histologic evaluation postoperatively. Other details related to the patients are shown in Table 2. The sensitivity of the filtered logistic model used in this study was found to be 33.3 and the specificity 97.8 ~ . The multivariable likelihood ratio statistic was significant at p = 0. ! 7 level. Table 1 Localization of strictures Site
No. of patients
Meatal Penile Penoscrotal Membranous Multiple
Per cent
3 3 I 4 ]
25 25 8.33 33.33 8.33
The logistic model yielded that, among the risk factors included in the model, postoperative infection was the most important one in the development of urethral stricture after T U R P with an O.R. = 5.5 (p = 0.011). There was no significant effect of preoperative infection on stricture development (p = 0.50). Age was found to be the second most important risk factor. Increase in age caused a decrease in risk; the probability of developing urethral stricture increased from 0.02 to 0.11 as age decreased from 74 (mean + S.D.), to 58 (mean _ S.D.). The third and fourth significant risk factors appeared to be the duration of postoperative catheterization and pathology, respectively. Increase in postoperative catheterization from 4 to 7 days increases the corresponding risk from 0.04 to 0.12. The O.R. related to pathology was 1.56. Table 2 Documented data related to patients With stricture
Age (years) Resection time (min) Resected tissue (g) Preoperative catheterization (days) Postoperative catheterization (days)
4*
Without stricture
(rain)
(max)
(mean)
(rain)
(max)
(mean)
49 10 3
75 60 50
61.7 35.8 17.2
45 15 2
96 85 75
66.8 42.3 28.9
0
19
4.5
0
180
19.1
4
9
4.9
4
11
4.1
International Urology and Nephroloyy 24, 1992
52
Balbay et aL : Urethral stricture after T U R P
Discussion
In this study the incidence of urethral stricture development after T U R P was 11.65 ~ (12 out of 103 patients). This value is in agreement with those reported in the literature [1, 2]. We found that the most important risk factor was postoperative urinary infection which is in contradiction to other studies [2, 3, 4]. Although Lentz et al. [3] found no cause-effect relationship between stricture formation and positive urine culture, they stated that urinary infection should be vigorously treated prior to and after instrumentation. Since the cause of urethral stricture development had been shown to be urine leakage into the subepithelial space and subsequent inflammation and scar formation [3, 6], it is clear that infection, when coincident with the loss of urethral mucosal integrity, will cause periurethral inflammation and fibrosis subsequently, as occurred in the case of loss of urethral mucosal integrity due to transurethral resection and coincident postoperative infection. When urethral mucosal integrity is intact, the impact of urinary infection will be less severe, which is the case in preoperative infection. Age of the patient appeared to be the second most important factor in urethral stricture formation. The risk of stricture development was found to be higher in younger age groups;the mean age of patients without stricture was 66.8 while it was 61.7 for patients with stricture. Jorgensen et al. [4] reported no significant correlation between patient age and stricture development. This may be due to the similarity of patient ages in their ( + ) stricture and ( - ) stricture group (70.9 versus 71.5, respectively). We conclude that decreased tissue reaction with advancing age to inflammatory causes which would be expected to result in periurethral fibrosis may explain the effect of aging on urethral stricture development after TURP. The duration of postoperative urethral catheterization was also found to influence the development of stricture as the third most important factor. This finding had been confirmed by other studies, too [1, 2, 3]. Because every patient in our study had been catheterized with a 22 F Latex urethral catheter, we could not identify the effect of the catheter material on urethral stricture development. The effect of the histology of the disease appeared as the fourth most important factor in contrast to the findings of Lentz et al. [3]. Since prostatic adenocarcinoma is a continuously growing and unfortunately non-resectable disease, it may cause urethral narrowing by its growth without producing periurethral fibrosis.
Conclusion
Urinary infections, especially when present in the postoperative period, must be treated vigorously, and urethral catheters must be drawn out as quickly as possible after operation to prevent urethral stricture development after TURP.
International Urology and Nephrology 24, 1992
Balbay et aL : Urethral stricture after T U R P
53
References 1. Hammarsten, J., Lindqvist, K., Sunzel, H.: Urethral strictures following transurethral resection of the prostate. The role of the catheter. Br. J. UroL, 63, 397 (1989). 2. Hart, A. J. L., Fowler, J. W. : Incidence of urethral stricture after transurethral resection of prostate. Effects of urinary infection, urethral flora and catheter material and size. Urology, 18, 558 (1981). 3. Lentz, H. C., Mebust, W. K., Foret, J. D., Melchior, J. : Urethral stricture following transurethral prostatectomy. Review of 2223 resections. J. Urol., 117, 194 (1977). 4. Jorgensen, P. E., Weis, N., Bruun, E. : Etiology of urethral stricture following transurethral prostatectomy. A retrospective study. Scand. J. UroL NephroL, 20, 253 (1986). 5. Bailey, M. J., Shearer, R. J. : The role of internal urethrotomy in the prevention of urethral stricture following transurethral resection of prostate. Br. J. Urol., 57, 81 (1985). 6. Sherz, H. C., Kaplan, G. Wo : Etiology, diagnosis and management of urethral strictures in children. Urol. Clin. North Am., 17, 389 (1990).
International Urology and Nephrology 24, 1992
Development of Urethral Stricture after Transurethral Prostatectomy: A Retrospective Study M. D. BALBAY, A. ERGEN, A. SAHIN, M. LEKILI,
S. ULUCAY, E. KARAA~AOt3LU* Department of Urology, Hacettepe University Hospital; *Department of Biostatistics, Hacettepe University Medical Faculty, Ankara, Turkey (Accepted March 28, 1991) A total of 103 patients who were diagnosed to have benign prostatic hyperplasia (BPH) without preoperative urethral stricture and underwent transurethral prostatectomy (TURP) were evaluated retrospectively from patient charts. The incidence of urethral stricture development was calculated as 11.65% (12 out of 103 patients). Among the aetiologic factors analyzed, the most important ones appeared to be postoperative refection, age of the patient, duration of postoperative catheterization and histology of the disease, in the order of significance in the development of urethral stricture after TURP.
Introduction
Urethral stricture is not an u n c o m m o n complication of transurethral prostatectomy (TURP). The incidence of urethral stricture development after T U R P has been reported in the literature as 4-29 % [1, 2]. Although not known precisely, some factors such as age and race of the patient, the material and calibre of the catheters used, resection time, presence of urinary infection, disproportion between the size of resectoscope sheet and diameter of the urethra, experience of the surgeon have all been suspected to play a role in urethral stricture development after T U R P [3, 4]. It was claimed that preoperative internal urethrotomy prevents stricture development [5] and urinary infection should be treated vigorously [3]. In this study we investigated the incidence of urethral strictures among patients who underwent T U R P for BPH at our hospital, and evaluated the following risk factors : patient age, resection time, amount of tissue resected, duration of preoperative and postoperative catheterizations, preoperative and postoperative urinary infections and histology of disease, which were suspected to have a role in urethral stricture development.
4
VSP, Utrecht Akaddmiai Kiad6, Budapest
50
Balbay et aL : Urethral stricture after T U R P
Material and methods
One hundred and three BPH patients, aged 45 to 96 years, who underwent T U R P between 1987 and 1989 at the Department of Urology, Hacettepe University Hospital, were included in the study. They were evaluated at 6 to 12 months after operation. All patients were diagnosed to have BPH without urethral stricture. Urine cultures were taken from each patient during both the preoperative and the postoperative period. Any growth more than 105 colonies/ml in urine culture was accepted as urinary infection. All patients underwent T U R P with a 28 F Storz resectoscope under appropriate antibiotic coverage. Patients who had negative urine cultures were given an antibiotic prophylaxis with trimethoprim sulfametoxazole. Distilled water was used as irrigation fluid at operation and a 22 F Latex urethral catheter was inserted into the bladder transurethrally, the balloon of which was inflated with 30 or 35 cc of distilled water after completion of the operation. At the postoperative follow-up, patients who complained of a weak stream on urination were suspected to have urethral stricture and were examined endoscopically. When a urethral stricture was diagnosed, internal urethrotomy was performed with a Storz internal urethrotome at the same time. Patient charts were reviewed retrospectively. Two groups were formed according to urethral stricture development after TURP. For each patient in each group, age, operation time, amount of tissue resected, duration of preoperative and postoperative catheterizations, presence of preoperative and postoperative infections, as well as histologic diagnosis of the disease were documented for evaluation as risk factors. The risk factors in the development of urethral stricture after T U R P were analyzed by multivariate logistic regression and Odds Ratios (O.R.).
Results
Out of 103 patients, 12 (11.65 %) were diagnosed to have urethral stricture postoperatively. The distribution of strictures along the urethra is shown in Table 1. One patient who had two strictures - one of which was at the external meatus, and the other at the membranous urethra - is shown as multiple strictures in Table 1. We found that the most common site of stricture development after T U R P was the membranous urethra. Thirty-three out of 91 patients without urethral stricture (36.26 %) and 3 out of 12 patients with urethral stricture (25 %) had preoperative urinary infections, while 14 out of 91 patients without urethral stricture (15.38%) and 7 out of 12 patients with urethral stricture (58.33 %) had urinary infection postoperatively. Among patients without stricture 5 out of 91 (5.49 %), and with stricture 2 out of 12 (16.66 %) were diagnosed to have prostatic adenocarcinoma and the International Uroloyy and Nephroloyy 24, 1992
51
Balbay et aL: Urethral stricture after T U R P
remaining patients in both groups as BPH by histologic evaluation postoperatively. Other details related to the patients are shown in Table 2. The sensitivity of the filtered logistic model used in this study was found to be 33.3 and the specificity 97.8 ~ . The multivariable likelihood ratio statistic was significant at p = 0. ! 7 level. Table 1 Localization of strictures Site
No. of patients
Meatal Penile Penoscrotal Membranous Multiple
Per cent
3 3 I 4 ]
25 25 8.33 33.33 8.33
The logistic model yielded that, among the risk factors included in the model, postoperative infection was the most important one in the development of urethral stricture after T U R P with an O.R. = 5.5 (p = 0.011). There was no significant effect of preoperative infection on stricture development (p = 0.50). Age was found to be the second most important risk factor. Increase in age caused a decrease in risk; the probability of developing urethral stricture increased from 0.02 to 0.11 as age decreased from 74 (mean + S.D.), to 58 (mean _ S.D.). The third and fourth significant risk factors appeared to be the duration of postoperative catheterization and pathology, respectively. Increase in postoperative catheterization from 4 to 7 days increases the corresponding risk from 0.04 to 0.12. The O.R. related to pathology was 1.56. Table 2 Documented data related to patients With stricture
Age (years) Resection time (min) Resected tissue (g) Preoperative catheterization (days) Postoperative catheterization (days)
4*
Without stricture
(rain)
(max)
(mean)
(rain)
(max)
(mean)
49 10 3
75 60 50
61.7 35.8 17.2
45 15 2
96 85 75
66.8 42.3 28.9
0
19
4.5
0
180
19.1
4
9
4.9
4
11
4.1
International Urology and Nephroloyy 24, 1992
52
Balbay et aL : Urethral stricture after T U R P
Discussion
In this study the incidence of urethral stricture development after T U R P was 11.65 ~ (12 out of 103 patients). This value is in agreement with those reported in the literature [1, 2]. We found that the most important risk factor was postoperative urinary infection which is in contradiction to other studies [2, 3, 4]. Although Lentz et al. [3] found no cause-effect relationship between stricture formation and positive urine culture, they stated that urinary infection should be vigorously treated prior to and after instrumentation. Since the cause of urethral stricture development had been shown to be urine leakage into the subepithelial space and subsequent inflammation and scar formation [3, 6], it is clear that infection, when coincident with the loss of urethral mucosal integrity, will cause periurethral inflammation and fibrosis subsequently, as occurred in the case of loss of urethral mucosal integrity due to transurethral resection and coincident postoperative infection. When urethral mucosal integrity is intact, the impact of urinary infection will be less severe, which is the case in preoperative infection. Age of the patient appeared to be the second most important factor in urethral stricture formation. The risk of stricture development was found to be higher in younger age groups;the mean age of patients without stricture was 66.8 while it was 61.7 for patients with stricture. Jorgensen et al. [4] reported no significant correlation between patient age and stricture development. This may be due to the similarity of patient ages in their ( + ) stricture and ( - ) stricture group (70.9 versus 71.5, respectively). We conclude that decreased tissue reaction with advancing age to inflammatory causes which would be expected to result in periurethral fibrosis may explain the effect of aging on urethral stricture development after TURP. The duration of postoperative urethral catheterization was also found to influence the development of stricture as the third most important factor. This finding had been confirmed by other studies, too [1, 2, 3]. Because every patient in our study had been catheterized with a 22 F Latex urethral catheter, we could not identify the effect of the catheter material on urethral stricture development. The effect of the histology of the disease appeared as the fourth most important factor in contrast to the findings of Lentz et al. [3]. Since prostatic adenocarcinoma is a continuously growing and unfortunately non-resectable disease, it may cause urethral narrowing by its growth without producing periurethral fibrosis.
Conclusion
Urinary infections, especially when present in the postoperative period, must be treated vigorously, and urethral catheters must be drawn out as quickly as possible after operation to prevent urethral stricture development after TURP.
International Urology and Nephrology 24, 1992
Balbay et aL : Urethral stricture after T U R P
53
References 1. Hammarsten, J., Lindqvist, K., Sunzel, H.: Urethral strictures following transurethral resection of the prostate. The role of the catheter. Br. J. UroL, 63, 397 (1989). 2. Hart, A. J. L., Fowler, J. W. : Incidence of urethral stricture after transurethral resection of prostate. Effects of urinary infection, urethral flora and catheter material and size. Urology, 18, 558 (1981). 3. Lentz, H. C., Mebust, W. K., Foret, J. D., Melchior, J. : Urethral stricture following transurethral prostatectomy. Review of 2223 resections. J. Urol., 117, 194 (1977). 4. Jorgensen, P. E., Weis, N., Bruun, E. : Etiology of urethral stricture following transurethral prostatectomy. A retrospective study. Scand. J. UroL NephroL, 20, 253 (1986). 5. Bailey, M. J., Shearer, R. J. : The role of internal urethrotomy in the prevention of urethral stricture following transurethral resection of prostate. Br. J. Urol., 57, 81 (1985). 6. Sherz, H. C., Kaplan, G. Wo : Etiology, diagnosis and management of urethral strictures in children. Urol. Clin. North Am., 17, 389 (1990).
International Urology and Nephrology 24, 1992
