Richard W. Norman

Androgen metabolism in men receiving finasteride before prostatectomy

Oral administration of finasteride, a 5 alpha-reductase inhibitor, affects intraprostatic androgens by suppressing dihydrotestosterone and increasing testosterone. This study was designed to determine the correlation of these effects of finasteride with changes in serum dihydrotestosterone, testosterone and androstanediol glucuronide. In a double blind, placebo-controlled study, 27 men with symptomatic benign prostatic hyperplasia were treated with placebo or 1 or 5 mg. per day finasteride for 6 to 8 weeks before transurethral resection of the prostate. There was no significant change in serum testosterone in any group, or in serum dihydrotestosterone or androstanediol glucuronide in the placebo group. There was a decrease in serum dihydrotestosterone by 66 +/- 4% and 70 +/- 8% (p = 0.32), and of serum androstanediol glucuronide by 78 +/- 3% and 86 +/- 3% (p = 0.012) in the 1 and 5 mg. finasteride groups, respectively. Intraprostatic dihydrotestosterone in the placebo group decreased from 18.6 +/- 1.4 nmol./kg. to 3.8 +/- 1.0 nmol./kg. and 1.7 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (p = 0.049 between 1 mg. and 5 mg. finasteride). Intraprostatic testosterone in the placebo group increased from 1.1 +/- 0.2 nmol./kg. to 7.6 +/- 1.0 nmol./kg. and 8.3 +/- 0.7 nmol./kg. with 1 mg. and 5 mg. finasteride, respectively (no significant difference between 1 mg. and 5 mg. finasteride). Serum and intraprostatic dihydrotestosterone correlated (p = 0.002). There was no correlation between intraprostatic dihydrotestosterone and serum androstanediol glucuronide. We conclude that 5 mg. of finasteride cause greater inhibition of intraprostatic 5 alpha-reductase than 1 mg. and that serum dihydrotestosterone is a better marker of intraprostatic dihydrotestosterone than androstanediol glucuronide.

Analyses of Indications for and Outcomes of Epididymectomy

PURPOSE We analyzed the contemporary indications for epididymectomy, and quantified outcomes in terms of symptom resolution, complications and patient satisfaction. MATERIALS AND METHODS The indications for surgery and outcomes for 57 patients who underwent epididymectomy between 1990 and 1994 were evaluated. RESULTS A total of 30 patients (53%) underwent surgery for epididymal cysts and 27 (47%) for chronic epididymitis or epididymalgia. There was greater patient satisfaction among the cyst group (92%) compared to the epididymitis/epididymalgia group (43%, p < 0.001). Furthermore, more patients in the latter group complained of subsequent problems that they considered related to the procedure. CONCLUSIONS The outcome of epididymectomy, is significantly more favorable in patients with epididymal cysts than with chronic epididymitis or intractable epididymal pain. Epididymectomy should be reserved for the former group but avoided in the latter cases unless they have been carefully counseled regarding the likelihood of poor results.

OPTIMAL PREVENTION AND MANAGEMENT OF PROXIMAL URETERAL STENT MIGRATION AND REMIGRATION

PURPOSE We evaluated issues associated with proximal ureteral stent migration and remigration, including causes and management, and the predictability of ureteral length. MATERIALS AND METHODS All proximal ureteral stent migrations that occurred from January 1997 to March 2000 were reviewed. Characteristics and treatment of the 33 patients with proximal ureteral stent migration were compared with those of 66 randomly selected controls who did not have stent migration. We also analyzed a subgroup of 6 cases of remigration. RESULTS Of the ureteral stents 2% migrated proximally. Mean height was greater in patients with versus without a migrated stent (p = 0.028). The stent-to-ureter length ratio was lower in the migrated than in the nonmigrated group (p <0.0001). Patient height and side of migration were significant predictors of ureteral length (R2 = 0.3511, p <0.0001 and 0.0007, respectively). Of the patients who required continued ureteral stenting migrated stent management included placement of a longer stent in 9 (group 1) and a stent of equal length in 4 (group 2), and repositioning of the original stent in 4 (group 3). There was no remigration in group 1. However, migration recurred in 2 patients in group 2 (50%) and in all 4 in group 3 (100%). CONCLUSIONS Proximal migration occurs when a stent is too short for the ureter. We recommend that ureteral length should be measured directly from an x-ray to select the optimal stent length. If it is necessary to continue stenting a ureter after migration has been detected, a longer stent should be placed.

Dietary Restriction of Sodium as a Means of Reducing Urinary Cystine

We assessed 5 patients with recurrent cystine urolithiasis before and after implementation of a low sodium diet. This diet led to a significant decrease in the 24-hour urinary excretion of sodium and cystine. Dietary restriction of sodium should be an important component of the therapeutic strategy of patients with cystinuria.

Cytogenetic Abnormalities Associated with Renal Cell Carcinoma

Cytogenetic analysis was performed on 23 renal cell carcinomas (21 sporadic and 2 associated with von Hippel-Lindaus disease). Clonal chromosomal abnormalities were found in 19 of 21 of the sporadic tumors. The most frequent abnormalities were a loss or rearrangement of material in 3p (11 of 21 cases) or an extra chromosome 7 (7 of 21 cases). Correlation between specific chromosomal abnormalities and clinical presentation was absent with the exception of trisomy 7 and -Y, which occurred only in patients more than 60 years old. An increasing number of cytogenetic abnormalities were associated with a greater likelihood of renal vein and/or capsule involvement. Both patients with von Hippel-Lindaus disease had tumors with a normal karyotype.

Effects of dietary fat on the urinary risk factors of calcium stone disease

OBJECTIVES To assess the association between dietary fat and various urinary risk factors of calcium stone disease in a group of calcium stoneformers attending an outpatient stone clinic. METHODS Mean daily fat intake from self-recorded 4-day dietary food records and mean 24-hour urinary risk factors from two separate collections were evaluated in 476 patients selected randomly from an adult population attending an outpatient stone clinic for the first time. RESULTS Mean daily total fat intake for men and women was significantly different at 105.6 and 78.1 g, respectively. Examination of the relationship between total fat intake and 24-hour urinary volume, pH, and excretions of magnesium, citrate, oxalate, calcium, and uric acid revealed no significant regressions in men and only a weak association between fat intake and urinary uric acid in women. CONCLUSIONS Dietary fat does not have a significant effect on the urinary risk factors of calcium stone disease.

Cystitis associated with tiaprofenic acid.

Ten patients with cystitis associated with tiaprofenic acid were reviewed. All patients displayed similar cystoscopic and histological features, and all failed a variety of initial therapies but achieved a dramatic improvement or resolution of symptoms with discontinuation of the tiaprofenic acid. Drug-induced cystitis may be more common than previously recognized.

Serum phosphate in stone formers: what does a low serum phosphate level mean?

PURPOSE Metabolic evaluation is indicated in stone formers to identify and subsequently modify risk factors for nephrolithiasis. Some believe that serum phosphate may be an important indicator of nephrolithiasis risk. We determined whether serum phosphate is an independent risk factor for recurrent calcium stone formation and whether it may be used as an early marker for occult disease, such as hyperparathyroidism. MATERIALS AND METHODS The charts of all patients with regular long-term stone clinic followup were reviewed. Initial serum phosphate levels were compared with stone recurrence, complications due to stones, initial visit urinary laboratory values and the medical diagnoses made during followup. Unpaired 2-sample t tests, and correlation and logistic regression analyses were performed with statistical significance at p <0.05. RESULTS Data were available on 51 men and 25 women 22 to 74 years old (mean age 52). Of the patients 50 were recurrent and 26 were single stone formers. Serum phosphate levels were lower in women than in men. No consistent associations existed between initial or future serum phosphate levels and stone recurrence, complications from stones, urinary values or other medical diagnoses made during followup. CONCLUSIONS Serum phosphate does not appear to be an independent risk factor for urinary tract stone recurrence or complications, or a reliable early predictor of occult disease.

Acute reversible kidney injury secondary to bilateral ureteric obstruction

BACKGROUND Acute reversible kidney injury (ARKI) secondary to bilateral ureteric obstruction (BUO) is a common urological problem. Our goals were to describe the etiology, management and outcomes of such patients identified between 2006 and 2009 and to compare them with a similar historical study published in 1982. METHODS Chart review was performed on 49 patients with AKRI secondary to BUO. ARKI was defined as ≥33% decrease in serum creatinine after intervention. Those with malignant and benign causes of obstruction were identified and management and outcome data were collected. RESULTS Of these 49 patients, 83% had BUO secondary to malignancy, 28% of these presenting for the first time. Prevalence of bladder cancer was increased (p = 0.04) and cervix trended lower (p = 0.07) compared with the earlier study; prostate cancer was unchanged (p = 0.51). The average survival was 239 days; 90% of patients died within a year after presenting with BUO from a malignant etiology. Compared with the 1982 group, there were trends towards a decrease in the frequency of retroperitoneal fibrosis (p = 0.08) and an increase in bilateral ureteric calculi (p = 0.16) in the benign group. CONCLUSIONS Patients with ARKI secondary to BUO most likely have an underlying malignancy, with almost a third of them being diagnosed for the first time. Prevalence of bladder cancer increased while cervical cancer trended lower. The cause for the former is unclear; the latter may be due to aggressive screening. Prostate cancer remained unchanged despite the widespread implementation of prostate-specific antigen testing. Patients with an underlying malignancy do poorly and those with a newly diagnosed malignancy do worst. Those with ARKI secondary to benign causes did well.

Retroperitoneal Air, Extracorporeal Shock Wave Lithotripsy and Epidural Anesthesia

During a 13-month period, 1,344 patients underwent extracorporeal shock wave lithotripsy. Plain x-rays done routinely 24 hours after lithotripsy to assess stone fragmentation revealed evidence of retroperitoneal air in 6 patients. All 6 patients had epidural anesthesia induced by loss of resistance to air in a syringe to identify the epidural space. It was believed likely that this was the cause of the air and 2 types of distribution were identified: 1 showed tracking of air along spinal nerves and 1 along tissue planes. This hypothesis eventually was confirmed by 2 patients in whom the air was identified after epidural anesthesia but before extracorporeal shock wave lithotripsy. Retroperitoneal air is found in a small number of patients undergoing epidural anesthesia and extracorporeal shock wave lithotripsy, and physicians treating these patients in the early postoperative period should be aware of this possible radiological finding and appreciate its benign nature.