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RE: FACTORS PREDICTING RECOVERY OF ERECTIONS AFTER RADICAL PROSTATECTOMY
634
LETTERS TO THE EDITOR
degree of bladder filling and known to be difficult to obtain in the empty bladder. The authors do not address this issue. Various methods have been proposed to take intravesical volume into account, although none is in widespread use. We were primarily concerned with the assessment of intra-observer and interobserver variability in 1 measure, ultrasound estimated bladder weight, which is based on the assumption that the bladder resembles a sphere.2 Variability increased when cubed bladder wall thickness measurements were used in the calculation, and this problem was compounded by the inclusion of errors inherent to ultrasound based assessment of intravesical volume. Compared to the aforementioned measurements initial ultrasound estimated bladder weight was 29 to 446 gm. (median 101) and the repeat measurement was 34 to 522 gm. (median 109). The mean of the paired differences was 7 gm. but the SD of 54 gm. was unacceptably high. We believe that development of a reliable noninvasive measure of detrusor hypertrophy is a challenge remaining to be completed. Respectfully, V. S. Kirchin, T. Cuming and R. C. Beard Department of Urology Worthing Hospital Worthing, United Kingdom and P. J. Thomas Department of Urology Royal Sussex County Hospital Brighton, United Kingdom 1. Kirchin, V. S., Cuming, T., Beard, R. C. et al: Ultrasound estimated bladder wall volume: variability and relation to intravesical volume. Neurourol Urodyn, 18: 397, 1999 2. Kojima, M., Inui, E., Ochiai, A. et al: Ultrasonic estimation of bladder weight as a measure of bladder hypertrophy in men with infravesical obstruction: a preliminary report. Urology, 47: 942, 1996
Reply by Authors. We agree with Kirchin et al that it seems possible to measure bladder wall thickness with acceptable reproducibility. They report a slightly larger intra-observer variation of bladder wall thickness compared to our results. This finding can probably be explained by differences in measuring technique and patient selection, which included men with lower urinary tract symptoms/acute retention. Kirchin et al are concerned that “. . .bladder wall thickness measurement in isolation is not clinically valuable as this measurement is dependent on degree of bladder filling and known to be difficult to obtain in the empty bladder.” However, the purpose of our study was to assess intra-observer and interobserver variation of detrusor measurements regardless of bladder volume. We agree that the wall of an empty bladder may be difficult to visualize. Jequier and Rousseau noted that bladder wall thickness is dependent on the degree of bladder fullness.1 We also agree that there are inherent errors in ultrasound assessment of bladder volume but the clinical importance of these errors in association with detrusor thickness measurements has not been determined. In an evaluation of the clinical usefulness of the ultrasound method in children the range of variation in bladder wall thickness with age as well as bladder fullness needs to be assessed in healthy individuals and patients with well-defined bladder disease. We recently completed a study of these relationships in healthy children.
To the Editor. The authors identified factors that predicted recovery of erections after radical prostatectomy in 314 consecutive men with prostate cancer. At 3 years after bilateral nerve sparing 76%, 56% and 47% of men with full erections preoperatively who were younger than 60, 60 to 65 and older than 65 years had erections “sufficient for intercourse,” respectively. My concern regards their definition of potency, which was based on a 5-point scale. Category 3, “partial erections occasionally satisfactory for intercourse,” is included in the definition of postoperative potency. As a urologist specializing in erectile dysfunction and as a member of the Society for the Study of Impotence, I consider men in category 3 to have impotence rather than potency. Including men who have partial erections that are only occasionally satisfactory for intercourse severely distorts the data and is misleading. I am more interested in the percentage of men who had category 1, that is full, erections as this category is the only one that I consider appropriate for describing postoperative potency. Category 2, “recently diminished erections,” is hard to understand in postoperative patients but this category was considered to define postoperative potency. I would like the authors to clarify the definition of postoperative category 2 and to indicate the percentage of men who had full or normal erections in the categories. As long as fuzzy definitions of potency are used in radical prostatectomy studies, I believe that we will continue to overestimate the degree of normal or near normal erectile function in these patients after surgery. Respectfully, Joel M. Kaufman Aurora Urology 1411 S. Potomac, Suite 250 Aurora, Colorado 80012
Reply by Authors. We used the historical definition of potency after radical prostatectomy, which is achieving erections suitable for intercourse. In our series 76%, 55% and 49% of men with full erections preoperatively who were younger than 60, 60 to 65 and older than 65 years, respectively, were expected to recover erections sufficient for intercourse at 3 years after bilateral nerve sparing. We agree with Kaufman that a weakness of our approach is that we did not distinguish between the frequency of erections adequate for intercourse, which were in category 2 (diminished quality of erections on a regular basis), and those in category 3 (diminished quality of erections occasionally suitable for intercourse). However, Walsh et al reported similar results in patient interviews administered by a skilled questioner to those with the validated questionnaire in our study.1 In addition, our question regarding quality of postoperative erections essentially corresponds to questions 3 and 4 in the International Index of Erectile Function questionnaire.2 Although these data were collected prospectively before widespread use of validated questionnaires, we agree that future studies should use a broader scale for measuring erectile function, such as the International Index of Erectile Function questionnaire. 1. Walsh, P. C., Marschke, P., Ricker, D. D. et al: Potency and continence following anatomic radical prostatectomy: patient versus physician reported outcomes. J Urol, suppl., 161: 387, abstract 1501, 1999 2. Rosen, R. C., Riley, A., Wagner, G. et al: The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology, 49: 822, 1997
1. Jequier, S. and Rousseau, O.: Sonographic measurements of the normal bladder wall in children. AJR Am J Roentgenol, 149: 563, 1987
ERRATUM CME QUESTION FOR APRIL 2001 ISSUE RE: FACTORS PREDICTING RECOVERY OF ERECTIONS AFTER RADICAL PROSTATECTOMY F. Rabbani, A. M. F. Stapleton, M. W. Kattan, T. M. Wheeler and P. T. Scardino J Urol, 164: 1929 –1934, 2000
Volume 165, No. 4, page 1265, question 1: The correct answer is perioperative vaginal or urethral injury.
LETTERS TO THE EDITOR
degree of bladder filling and known to be difficult to obtain in the empty bladder. The authors do not address this issue. Various methods have been proposed to take intravesical volume into account, although none is in widespread use. We were primarily concerned with the assessment of intra-observer and interobserver variability in 1 measure, ultrasound estimated bladder weight, which is based on the assumption that the bladder resembles a sphere.2 Variability increased when cubed bladder wall thickness measurements were used in the calculation, and this problem was compounded by the inclusion of errors inherent to ultrasound based assessment of intravesical volume. Compared to the aforementioned measurements initial ultrasound estimated bladder weight was 29 to 446 gm. (median 101) and the repeat measurement was 34 to 522 gm. (median 109). The mean of the paired differences was 7 gm. but the SD of 54 gm. was unacceptably high. We believe that development of a reliable noninvasive measure of detrusor hypertrophy is a challenge remaining to be completed. Respectfully, V. S. Kirchin, T. Cuming and R. C. Beard Department of Urology Worthing Hospital Worthing, United Kingdom and P. J. Thomas Department of Urology Royal Sussex County Hospital Brighton, United Kingdom 1. Kirchin, V. S., Cuming, T., Beard, R. C. et al: Ultrasound estimated bladder wall volume: variability and relation to intravesical volume. Neurourol Urodyn, 18: 397, 1999 2. Kojima, M., Inui, E., Ochiai, A. et al: Ultrasonic estimation of bladder weight as a measure of bladder hypertrophy in men with infravesical obstruction: a preliminary report. Urology, 47: 942, 1996
Reply by Authors. We agree with Kirchin et al that it seems possible to measure bladder wall thickness with acceptable reproducibility. They report a slightly larger intra-observer variation of bladder wall thickness compared to our results. This finding can probably be explained by differences in measuring technique and patient selection, which included men with lower urinary tract symptoms/acute retention. Kirchin et al are concerned that “. . .bladder wall thickness measurement in isolation is not clinically valuable as this measurement is dependent on degree of bladder filling and known to be difficult to obtain in the empty bladder.” However, the purpose of our study was to assess intra-observer and interobserver variation of detrusor measurements regardless of bladder volume. We agree that the wall of an empty bladder may be difficult to visualize. Jequier and Rousseau noted that bladder wall thickness is dependent on the degree of bladder fullness.1 We also agree that there are inherent errors in ultrasound assessment of bladder volume but the clinical importance of these errors in association with detrusor thickness measurements has not been determined. In an evaluation of the clinical usefulness of the ultrasound method in children the range of variation in bladder wall thickness with age as well as bladder fullness needs to be assessed in healthy individuals and patients with well-defined bladder disease. We recently completed a study of these relationships in healthy children.
To the Editor. The authors identified factors that predicted recovery of erections after radical prostatectomy in 314 consecutive men with prostate cancer. At 3 years after bilateral nerve sparing 76%, 56% and 47% of men with full erections preoperatively who were younger than 60, 60 to 65 and older than 65 years had erections “sufficient for intercourse,” respectively. My concern regards their definition of potency, which was based on a 5-point scale. Category 3, “partial erections occasionally satisfactory for intercourse,” is included in the definition of postoperative potency. As a urologist specializing in erectile dysfunction and as a member of the Society for the Study of Impotence, I consider men in category 3 to have impotence rather than potency. Including men who have partial erections that are only occasionally satisfactory for intercourse severely distorts the data and is misleading. I am more interested in the percentage of men who had category 1, that is full, erections as this category is the only one that I consider appropriate for describing postoperative potency. Category 2, “recently diminished erections,” is hard to understand in postoperative patients but this category was considered to define postoperative potency. I would like the authors to clarify the definition of postoperative category 2 and to indicate the percentage of men who had full or normal erections in the categories. As long as fuzzy definitions of potency are used in radical prostatectomy studies, I believe that we will continue to overestimate the degree of normal or near normal erectile function in these patients after surgery. Respectfully, Joel M. Kaufman Aurora Urology 1411 S. Potomac, Suite 250 Aurora, Colorado 80012
Reply by Authors. We used the historical definition of potency after radical prostatectomy, which is achieving erections suitable for intercourse. In our series 76%, 55% and 49% of men with full erections preoperatively who were younger than 60, 60 to 65 and older than 65 years, respectively, were expected to recover erections sufficient for intercourse at 3 years after bilateral nerve sparing. We agree with Kaufman that a weakness of our approach is that we did not distinguish between the frequency of erections adequate for intercourse, which were in category 2 (diminished quality of erections on a regular basis), and those in category 3 (diminished quality of erections occasionally suitable for intercourse). However, Walsh et al reported similar results in patient interviews administered by a skilled questioner to those with the validated questionnaire in our study.1 In addition, our question regarding quality of postoperative erections essentially corresponds to questions 3 and 4 in the International Index of Erectile Function questionnaire.2 Although these data were collected prospectively before widespread use of validated questionnaires, we agree that future studies should use a broader scale for measuring erectile function, such as the International Index of Erectile Function questionnaire. 1. Walsh, P. C., Marschke, P., Ricker, D. D. et al: Potency and continence following anatomic radical prostatectomy: patient versus physician reported outcomes. J Urol, suppl., 161: 387, abstract 1501, 1999 2. Rosen, R. C., Riley, A., Wagner, G. et al: The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology, 49: 822, 1997
1. Jequier, S. and Rousseau, O.: Sonographic measurements of the normal bladder wall in children. AJR Am J Roentgenol, 149: 563, 1987
ERRATUM CME QUESTION FOR APRIL 2001 ISSUE RE: FACTORS PREDICTING RECOVERY OF ERECTIONS AFTER RADICAL PROSTATECTOMY F. Rabbani, A. M. F. Stapleton, M. W. Kattan, T. M. Wheeler and P. T. Scardino J Urol, 164: 1929 –1934, 2000
Volume 165, No. 4, page 1265, question 1: The correct answer is perioperative vaginal or urethral injury.