Failed endopyelotomy: implications for future surgery on the ureteropelvic junction.

During the last 8 years we performed 212 endopyelotomies with an overall success rate of 86%. To determine if the failed endopyelotomies resulted in a more difficult subsequent open corrective procedure, we compared the procedures and outcomes of 15 failed endopyelotomies with 16 control patients undergoing pyeloplasty who had not undergone a previous endopyelotomy. The variables of duration of the surgical procedure, average estimated blood loss, average number of transfusions and average length of hospitalization were analyzed for both groups. No statistically significant differences were detected for any of these variables. We conclude that despite a previously failed endopyelotomy, a subsequent open operation on the ureteropelvic junction, although slightly more difficult, was not associated with an increased morbidity rate nor less successful than de novo pyeloplasty. Therefore, we continue to advocate endopyelotomy as the procedure of choice for obstruction of the ureteropelvic junction.

Results of 212 consecutive endopyelotomies: an 8-year followup.

Between 1983 and 1991 we performed 212 endopyelotomies on 110 cases of primary and 102 of secondary obstruction of the ureteropelvic junction. Of the 189 patients in the series 89% have been followed for a minimum of 6 months postoperatively, 63% for more than 3 years (3 to 8-year followup). Our overall success rate has been 86% with little difference being detected between the success that we have obtained with primary and secondary obstructions (85% versus 86%). Other variables, such as patient age, sex or side of obstruction, have little bearing on the outcome of the procedure. Endopyelotomy is passing the test of time as a safe and reliable means to correct ureteropelvic junction obstruction. Endopyelotomy should be the first choice for the correction of ureteropelvic junction obstruction in most patients.

Transmembrane oxalate exchange: its relationship to idiopathic calcium oxalate nephrolithiasis.

Red blood cell oxalate flux rates were measured in various populations of stone patients and controls. Idiopathic and normocalciuric stone patients and post-prostatectomy patients exhibited rates significantly greater than the nonstone controls. The fact that this abnormality was not limited to patients with calcium oxalate nephrolithiasis suggests that this cellular defect is not universal nor an important etiological factor for calcium oxalate nephrolithiasis.

RP-30A: new tracer for detection of changes in testicular blood flow in rat torsion model.

RP-30A is a radioactive tracer being evaluated for the detection of regional myocardial blood flow. This study compares RP-30A to technetium 99m pertechnetate as radioactive tracers for the detection of testicular blood flow changes in early testicular torsion. The left testis of adult male Sprague-Dawley rats was subjected to either thirty or sixty minutes of 720 degrees torsion. Injections of RP-30A or 99mTc-pertechnetate followed by sacrifice and scintillation counting of the testes was performed. No significant difference was detected between the torted testes and the right control testes in both groups receiving 99mTc-pertechnetate and the thirty-minute group receiving RP-30A. The torted testes of the sixty-minute group receiving RP-30A revealed a significant difference (decrease) in uptake indicating that RP-30A may be a more sensitive tracer in detecting testicular blood flow changes in early testicular torsion.

Urinary excretion of oxalate by patients with renal hypercalciuric stone disease. Effect of chronic treatment with hydrochlorothiazide.

Hydrochlorothiazide is employed to reduce calcium excretion in patients with urinary stone disease secondary to renal leak hypercalciuria. Because the drug also has been reported to be a competitive inhibitor of oxalate excretion by the renal tubules, we sought to determine whether chronic use indeed affected the amount of oxalate excreted. Patients taking hydrochlorothiazide 50 mg daily did not have a statistically significant reduction in twenty-four-hour urinary oxalate on their customary diets (pretreatment 37 +/- 3 mg/day [mean +/- S.E.M.; N = 22]; at one year 36 +/- 3 mg/day [N = 22]; at two years 37 +/- 3 mg/day [N = 16]). In 12 patients who voluntarily collected twelve-hour urine specimens after dinner on the third day of a low-oxalate diet and again the next day after a 1 g oxalate load, hydrochlorothiazide had no significant effect on oxalate excretion (19 +/- 2.3 mmol oxalate/mol creatinine on hydrochlorothiazide versus 20.6 +/- 2.6 mmol off the drug after low oxalate meal; 50 +/- 7.8 mmol/mol creatinine on hydrochlorothiazide versus 56.2 +/- 7.5 mmol off the drug after an oxalate load). As expected, there was a significant reduction in urinary calcium excretion and thus of calcium oxalate urinary saturation during hydrochlorothiazide administration. Hydrochlorothiazide by itself is not sufficient to reduce oxalate excretion in patients with renal leak hypercalciuria.

Absence of effect of allopurinol on oxalate excretion by stone patients on random and controlled diets.

After 1 year of allopurinol treatment in 36 patients with a history of uric acid and/or calcium oxalate lithiasis and hyperuricosuria, we observed that in addition to the desired decreases in uric acid there were apparently significant decreases in urinary oxalate levels: 37 +/- 3 mg. per day (mean +/- standard error) before therapy and 31 +/- 4 mg. per day after a mean decrease of 16% (p less than 0.05) with an equivalent decrease in the supersaturation (calcium oxalate) of the urine. However, the decrease in oxalate could have been related to changes in dietary habits rather than to any specific effects of allopurinol on oxalate metabolism. Therefore, we recruited 26 of the patients for a study in which dietary factors were controlled. Each participant was assigned to 1 of 3 diet groups: low or high protein, or a customary diet. Each patient collected a urine specimen while on allopurinol and again after the medication was discontinued. With analytical procedures that we ascertained to be free of any significant methodological bias, we observed no significant changes in urinary oxalate excretion that could be attributed to allopurinol. There were significant differences in oxalate excretion on versus off allopurinol between the low and high protein groups, with higher oxalate levels found for the latter group. Our results indicate that allopurinol does not have a specific effect on oxalate metabolism or oxaluria.

Cerebrovascular accidents. Urological effects and management.

Advanced age should not be a contraindication to the evaluation of a geriatric patient who presents with bladder dysfunction after a cerebrovascular accident. A team approach consisting of the geriatrician and the urologist is beneficial to the care of the patient. Once a problem has been identified, the pathophysiology can be worked out and a rational approach can be formulated for the patient. A return to continence in most patients is possible with a combination of medical and surgical treatment.

Therapeutic options for the management of upper tract calculi.

The cry of "ESWL for all" was heard at the 84th Annual Meeting of the American Urological Association, and actually, this is not far from the truth. Those physicians who are not familiar with percutaneous techniques, or who do not have the necessary equipment available, may actually attempt ESWL for all calculi regardless of stone burden or location. Patients who are interested in avoiding manipulation may request ESWL, even if the results may not be as good as those obtained with concomitant manipulation or with percutaneous procedures. Nevertheless, indications still exist for percutaneous techniques, and these procedures will not become obsolete even as ESWL technology advances. Studies are being conducted to identify the ideal treatment for all varieties of stones in the genitourinary system. As ESWL and endoscopic technology continue to advance, the treatment of stone disease will continue to change.

Impact of percutaneous renal stone removal on renal function: assessment by urinary lysozyme activity.

Lysozyme in the urine in concentrations greater than 3 micrograms per milligram of creatinine reflects renal tubular disease or dysfunction in patients without bowel disease or leukemia. We therefore used urine lysozyme assays to assess renal response to percutaneous nephrostomy and stone removal in 42 patients. Eight patients had striking increases (4.2-21.1 [mean 7.58] micrograms/mg creatinine) immediately after nephrostomy puncture in urine obtained directly from the punctured kidney. Lysozyme declined sharply thereafter and was within normal limits in all cases by postoperative day 3. This increase appeared to result from bleeding into the urine from the tract. Five other patients had lysozymuria on admission, only 1 of whom had a sharp increase after nephrostomy puncture. In the remaining patients, the lysozyme levels remained within normal limits throughout the hospital course. These data are further evidence of the absence of significant deleterious effects of nephrostomy puncture on the kidney.

Anatomy of the ureter.

Ureteral anatomy is vital to the endoscopist as this knowledge will facilitate the endoscopic manipulation of the ureter and minimize the morbidity that can be associated with these procedures.

Dietary protein levels affect the excretion of oxalate and calcium in patients with absorptive hypercalciuria type II.

A total of 12 patients with absorptive hypercalciuria type II and 11 normal controls participated in a study to evaluate the effects of dietary protein levels on urinary calcium and oxalate excretion before and after a 1 gm. dose of oxalate. Two test periods were used during which calcium (less than 400 mg. per day) and oxalate were restricted. The first test was done under conditions of low dietary protein (12 per cent total caloric intake, 60 gm.) and the second test was done at a high protein level (25 per cent, 125 gm. protein). Twelve-hour urine specimens were obtained after dinner on day 3 of each diet (low and high protein) and again on day 4 when 1 gm. oxalate (spinach) was added to the dinner meal. The specimens were analyzed for calcium, oxalate and relative calcium oxalate saturation (concentration product ratio). There were no significant differences between the controls and subjects with absorptive hypercalciuria type II in oxalate excretion before the oxalate load on the low protein (controls 31.4 +/- 4.2 standard error, expressed as mmol. oxalate per mol. creatinine, and absorptive hypercalciuria type II 23.1 +/- 3.1) and high protein (controls 30.4 +/- 4.2 and absorptive hypercalciuria type II 28.8 +/- 5.9) diets. After the oxalate bolus the positive changes in oxalate excretion were 11.8 +/- 4.8 (low protein) and 17.8 +/- 4.7 (high protein) for controls, and 11.4 +/- 4.4 (low protein) and 31.8 +/- 5.2 (high protein) for patients with absorptive hypercalciuria type II. Thus, the increases in post-load urinary oxalate levels observed for controls and patients were greater on the high protein than on the low protein diets. After the oxalate load the increases in urinary oxalate and calcium oxalate supersaturation were significantly greater for patients with absorptive hypercalciuria type II than for control subjects for the high protein but not the low protein diets (p less than 0.05).