Yosuke Matsuta

THE NATURAL HISTORY OF SIMPLE RENAL CYSTS

PURPOSE Although simple renal cysts are common in older patients, little is known concerning their natural history. We examined the natural history of renal cysts by investigating the prevalence and sequential changes in their size and number in individuals. MATERIALS AND METHODS We collected data on 14,314 individuals who participated in a multiphasic health screening program at our institute in 1999. An ultrasound renal cyst prevalence survey was performed. As a longitudinal study, 45 patients with renal cysts were followed a mean of 6 years from January 1993 to December 1999. RESULTS In the prevalence survey 1,700 individuals (11.9%) had at least 1 renal cyst on ultrasound. The ratio of men-to-women with cysts was 2:1. The prevalence of renal cysts increased more than 7-fold with age from 5.1% in the fourth to 36.1% in the eighth decade of life. Our longitudinal study revealed that the majority of cysts increased in size and number. The average increase in size and the rate of enlargement were 2.82 mm. and 6.3% yearly, respectively. Cysts in patients younger than 50 years grew more rapidly than those in patients 50 years old and older, at a rate of 3.94 and 1.84 mm. yearly, respectively (p = 0.010). Multiloculated cysts progressed more rapidly than simple cysts (6.93 versus 2.18 mm. yearly, p <0.0001). CONCLUSIONS The prevalence of renal cysts increases with age and shows a remarkable difference in incidence by sex. Renal cysts progress in size and number, and appear to grow more rapidly in younger patients. The natural history of multiloculated cysts may be distinct from that of simple cysts and warrants further investigation.

Laparoscopic partial nephrectomy with a microwave tissue coagulator for small renal tumor.

PURPOSE Laparoscopic partial nephrectomy is a challenging procedure due to the risk of excessive bleeding. We evaluated the usefulness of a microwave tissue coagulator during laparoscopic partial nephrectomy for small renal tumor. MATERIALS AND METHODS From January to July 2000, 6 patients with small renal tumors, from 11 to 25 mm. in diameter, underwent laparoscopic partial nephrectomy with a microwave tissue coagulator without renal pedicle clamping. There were 4 patients who underwent the transperitoneal and 2 who underwent the retroperitoneal approaches. RESULTS Mean operating time was 186 minutes (range 131 to 239), and blood loss was minimal. Complications were mild and tolerable, and there was no significant deterioration of renal function. CONCLUSIONS Laparoscopic partial nephrectomy with a microwave tissue coagulator is a useful and less invasive method for treatment of select small renal tumors. Long-term followup of patients is warranted to determine the potential for cancer control with this method.

IMPACT OF INTERVENTIONAL THERAPY FOR BENIGN PROSTATIC HYPERPLASIA ON QUALITY OF LIFE AND SEXUAL FUNCTION: A PROSPECTIVE STUDY

PURPOSE Treatment for benign prostatic hyperplasia (BPH), including minimally invasive therapy, can impair the quality of life. We prospectively determined the impact of 4 different interventional therapies on quality of life and sexual function. MATERIALS AND METHODS A total of 173 patients were prospectively evaluated between February 1995 and August 1997. Treatment modalities consisted of standard transurethral resection of the prostate in 55 cases, transurethral microwave thermotherapy in 34, interstitial laser coagulation of the prostate in 42 and transurethral needle ablation in 42. Disease specific quality of life was assessed using the International Prostate Symptom Score quality of life assessment index and BPH impact index. In addition, a self-reporting questionnaire was completed before and 3 months after treatment to determine the impact on sexual function. RESULTS All 4 treatment groups showed significant improvement in the symptom score, International Prostate Symptom Score quality of life assessment score and BPH impact index score. Satisfaction with treatment was highest in patients treated with transurethral resection or laser coagulation. A mild to moderate decrease in erectile function was noted in 26.5%, 18.2%, 18.4% and 20.0% of the transurethral resection, microwave thermotherapy, laser coagulation and needle ablation groups, respectively, but there was no significant difference of mean pretreatment and posttreatment erectile function or libido scores in any group. Ejaculation loss or severe decrease in ejaculate volume was reported by 48.6%, 28.1%, 21.6% and 24.3% of the patients, respectively. Interestingly, 20 of the 44 patients (45. 5%) with loss of ejaculation or severe decrease in ejaculate reported deterioration of the sex life, while only 2 (3.6%) of the 56 without any change in ejaculate volume reported such deterioration. The association of ejaculatory dysfunction with an adverse impact on sexual activity was highly significant (p <0.0001). CONCLUSIONS Significant improvement in quality of life could be achieved with the present assessed interventional therapies. There was no significant change in sexual desire or erectile function with these therapies. Posttreatment sexual dysfunction appears to be mainly related to impaired ejaculatory function. Urologists should provide proper counseling regarding the possibility of this complication even in patients receiving minimally invasive treatment.

Role of Opioid and Metabotropic Glutamate 5 Receptors in Pudendal Inhibition of Bladder Overactivity in Cats

PURPOSE We determined the role of opioid and metabotropic glutamate 5 receptors in the pudendal inhibition of bladder overactivity. MATERIALS AND METHODS Cystometrograms were performed in 11 cats under α-chloralose anesthesia by slowly infusing the bladder with saline or 0.25% acetic acid. Pudendal nerve stimulation at intensities of multiple times the threshold to induce observable anal twitching was applied during cystometrogram to inhibit the bladder overactivity induced by acetic acid irritation. Naloxone (0.1, 0.3 and 1 mg/kg intravenously) was administered to block opioid receptors, followed by MTEP (3 and 10 mg/kg intravenously) to block metabotropic glutamate 5 receptors. After each drug dose, pudendal inhibition of bladder overactivity was examined during cystometrogram. RESULTS Acetic acid irritated the bladder, induced bladder overactivity and significantly decreased mean ± SE bladder capacity to 23.6% ± 2.7% of saline control capacity. Pudendal nerve stimulation at 1 to 1.5 and 4 × threshold suppressed bladder overactivity and significantly increased mean capacity to 57.5% ± 8.1% (p = 0.0005) and 106% ± 15% (p = 0.0002), respectively, of saline control capacity. Naloxone had no effect on pudendal inhibition but MTEP eliminated the inhibition induced by low intensity stimulation and significantly decreased the inhibition induced by high intensity stimulation (p <0.05). Neither naloxone nor MTEP altered baseline bladder overactivity. CONCLUSIONS Opioid receptors are not involved in pudendal inhibition of bladder overactivity but metabotropic glutamate 5 receptors are partially involved. Understanding neurotransmitter mechanisms could improve the efficacy of neuromodulation therapy for overactive bladder and identify molecular targets for developing new drugs for overactive bladder.

Symptom-specific quality of life in patients with benign prostatic hyperplasia.

Abstract Background: We investigated which factors are most bothersome to preoperative patients with benign prostatic hyperplasia (BPH).

Tubeless cutaneous ureterostomy: the Toyoda method revisited.

PURPOSE Cutaneous ureterostomy is a less invasive method of urinary diversion and an attractive option especially in patients at high risk. We retrospectively examined the long-term outcome of the method introduced by Toyoda. MATERIALS AND METHODS Since 1983 the Toyoda cutaneous ureterostomy has been performed in 61 patients (103 renal units) with a minimum of 3 months of followup. The ureteral patency rate was reviewed. RESULTS Of the 92 renal units (89%) that achieved a tubeless condition 53 (51%) had no hydronephrosis, 23 (22%) had mild to moderate hydronephrosis without the need for treatment, 14 (14%) were not evaluated during followup and 2 (2%) were removed due to subsequent renal pelvic and/or ureteral carcinoma. CONCLUSIONS A high ureteral patency rate was achieved with the Toyoda cutaneous ureterostomy. This procedure is a reasonable alternative to other forms of urinary diversion.

Acute normovolemic hemodilution for radical prostatectomy: Can it replace preoperative autologous blood transfusion?

Abstract Background: Although preoperative autologous blood donation (PAD) is accepted as a standard of care for radical prostatectomy, it is costly, time‐consuming and has risks associated with blood storage. Acute normovolemic hemodilution (ANH) is reported to be less expensive and to preserve blood components more effectively than PAD. In the present study, the efficacy and safety of these two autologous blood‐collection techniques were compared.

Long-lasting breaches in the bladder epithelium lead to storage dysfunction with increase in bladder PGE2 levels in the rat

Increase in bladder mucosal permeability can be reproduced by intravesical administration of protamine sulfate (PS); however, the influence of PS once administered into the bladder disappears within several days. We developed a chronic animal model of urothelial injury using PS. Insertion of a polyethylene catheter through the bladder dome was performed in female Wistar rats. The other end of the catheter was connected to an osmotic pump for continuous delivery of PS or vehicle for 2 wk. Urinary frequency (UF) and voided volume (VV) were measured in the metabolic cage. The fifth group of rats received a high dose of PS (10 mg/ml) for 2 wk and were followed for a further 2 wk without PS. The sixth group received a high dose of PS for 2 wk and loxoprofen (0.1 mg.kg(-1).day(-1)) for 4 wk. UF was increased, and VV was reduced in rats treated with a high dose of PS but not changed in rats treated with a vehicle or a low dose of PS (1 mg/ml). UF was further increased in the fifth group, while unchanged in the sixth group. Histological sections in rats treated with a high dose of PS demonstrated a loss of the upper layer of urothelial cells and an increased number of mast cells. PGE2 level in the bladder was significantly elevated in the fifth group. These results indicate that chronic urotherial injury leads to an increase in UF and a decrease in VV. Increased PGE2 level in the bladder is likely to be associated with long-lasting storage dysfunction.

Microwave thermotherapy for benign prostatic hyperplasia with the Dornier Urowave: response durability and variables potentially predicting response

OBJECTIVES To evaluate the clinical efficacy and durability of transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia. The clinical variables useful in predicting outcome were identified. METHODS From October 1996 to March 2000, 58 patients with symptomatic benign prostatic hyperplasia were treated with TUMT using the Urowave device. Treatment outcome was evaluated by the International Prostate Symptom Score (IPSS), quality-of-life assessment score, and urodynamic investigation. The patients were divided into those having a good and poor response on the basis of the degree of IPSS decrease at 3 months. RESULTS The mean IPSS significantly decreased from 19.2 at baseline to 13.3 at 3 months (P <0.0001). The mean quality-of-life score changed from 4.6 at baseline to 2.9 at 3 months (P <0.0001). No statistically significant differences in peak flow rate, postvoid residual volume, Schäfers obstruction scale, or detrusor pressure at peak flow were noted before or after TUMT. The pretreatment IPSS of the good response group was significantly higher than that of the poor response group (P=0.017). A more significant difference was obtained for the obstructive score (P = 0.002), and no difference was observed in the irritative score (P = 0.631). The Schäfer grading scale score of the good response group was significantly smaller than that of the poor response group (P = 0.047). CONCLUSIONS TUMT with the Urowave was effective in eliminating symptoms associated with benign prostatic hyperplasia, but did not markedly improve the objective voiding parameters. Patients with urodynamically less obstructive symptoms but subjectively more obstructive symptoms are therefore probably good candidates for TUMT.

Involvement of 5-HT3 receptors in pudendal inhibition of bladder overactivity in cats

In the present study, the role of 5-HT3 receptors in pudendal neuromodulation of bladder activity and its interaction with opioid receptors were investigated in anesthetized cats. The bladder was distended with either saline to induce normal bladder activity or with 0.25% acetic acid (AA) to induce bladder overactivity. Pudendal afferent nerves were activated by 5-Hz stimulation at multiples of the threshold (T) intensity for the induction of anal twitching. AA irritation significantly reduced bladder capacity to 16.5 ± 3.3% of saline control capacity, whereas pudendal nerve stimulation (PNS) at 1.5-2 and 3-4 T restored the capacity to 82.0 ± 12% (P = 0.0001) and 98.6 ± 15% (P < 0.0001), respectively. Cumulative doses (1-3 mg/kg iv) of ondansetron, a 5-HT3 receptor antagonist, eliminated low-intensity (1.5-2 T) PNS inhibition and reduced high-intensity (3-4 T) PNS inhibition of bladder overactivity. During saline distention, PNS at 1.5-2 and 3-4 T significantly increased bladder capacity to 173.2 ± 26.4% (P = 0.036) and 193.2 ± 22.5% (P = 0.008), respectively, of saline control capacity, but ondansetron (0.003-3 mg/kg iv) did not alter PNS inhibition. Ondansetron (0.1-3 mg/kg) also significantly (P < 0.05) increased control bladder capacity (50-200%) during either AA irritation or saline distention. In both conditions, the effects of low- and high-intensity PNS were not significantly different. After ondansetron (3 mg/kg) treatment, naloxone (1 mg/kg iv) significantly (P < 0.05) decreased control bladder capacity (40-70%) during either AA irritation or saline distention but failed to affect PNS inhibition. This study revealed that activation of 5-HT3 receptors has a role in PNS inhibition of bladder overactivity. It also indicated that 5-HT3 receptor antagonists might be useful for the treatment of overactive bladder symptoms.