Prolonged ureteral stenting in obstruction after renal transplantation: long-term results

BACKGROUND

Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our long-term follow-up results concerning endourologic treatment of ureteral obstruction after renal transplantation.

METHODS

Between May 1997 and September 2000, 15 patients with renal transplant obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting.

RESULTS

Percutaneous nephrostomies were performed successfully in all 15 kidneys. In 13 patients, antegrade ureteral stenting was attempted, which was successful in 11 patients (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in all patients, 90% of whom had no recurrence. During follow-up (36 to 71 months; mean 51), urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed. Success was defined as a reduction in hydronephrosis. No major complications were observed.

CONCLUSIONS

Modern endourologic procedures have replaced open reconstructive surgery in most patients with ureteral obstruction after renal transplantation, because they may offer a definitive treatment with low morbidity.

Obstructive uropathy in the transplanted kidney: definitive management with percutaneous nephrostomy and prolonged ureteral stenting

BACKGROUND AND PURPOSE

Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our experience with percutaneous nephrostomy and antegrade ureteral stenting, which may offer a primary and definitive alternative to open surgery.

PATIENTS AND METHODS

Fifteen patients with renal allograft obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting.

RESULTS

Percutaneous nephrostomies were successfully performed in all 15 kidneys: In 13 patients, antegrade ureteral stenting was attempted, this being successful in 11 (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in eight patients, and six of them (75%) did not have recurrences. During follow-up, urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed, and success was confirmed by the decline of creatinine and reduction in hydronephrosis. No major complication was observed.

CONCLUSION

Percutaneous nephrostomy and ureteral stenting is a safe and effective treatment for renal allograft obstructive uropathy. Prolonged ureteral stenting may offer a definitive treatment with low morbidity.

Role of percutaneous urinary diversion in malignant and benign obstructive uropathy

OBJECTIVES

We evaluated the feasibility and effectiveness of percutaneous urinary diversion in patients with obstructive uropathy.

PATIENTS AND METHODS

A total of 206 percutaneous nephrostomies (PCNs) (right-sided in 54, left in 56, and bilateral in 48) were performed in 102 male and 57 female patients 18 to 94 years old. In 125 patients, malignancy was the underlying cause of the obstruction and in 30, benign disease. In four patients, the cause remained unknown. In most patients (N = 154), the access was guided with both ultrasound and fluoroscopy.

RESULTS

Percutaneous nephrostomy was successful in 158 patients (99%). Antegrade ureteral stenting was attempted in 48 patients with a success rate of 81%. Fifteen days postprocedure, the mean urea and creatinine concentrations had declined from 160.8 mg/mL to 63 mg/mL and from 6.9 mg/dL to 2.2 mg/dL, respectively. In 66% of the patients, renal function returned to normal. In 28%, it improved with no need for hemodialysis, while in 6%, there was no improvement. Advanced age and prostate cancer were negative predictive factors for the improvement of renal function, whereas the BUN and creatinine concentrations before the procedure and performance of unilateral v bilateral nephrostomies were not. We did not have severe complications. Three patients received transfusions, and in one patient, a urinoma was drained percutaneously. Patients with malignancy had a median survival of 227 days.

CONCLUSION

Percutaneous urinary diversion under radiologic guidance is a safe and effective procedure for patients with obstructive uropathy.

Acute ureteral elongation in two animal models using a balloon expander

BACKGROUND AND OBJECTIVE

Repair of ureteral injuries and strictures often necessitates a major reconstructive procedure such as a psoas hitch, Boari flap, renal mobilization, ileal interposition, or autotransplantation. Tissue expanders have been used to elongate nerves and arteries. We examined the effects of acute ureteral elongation in two animal models.

MATERIALS AND METHODS

In eight female rabbits, we exposed the left ureter through a midline incision and placed a Ruiz-Cohen balloon beneath the undermined portion. The expander was then inflated until the ureter was tightly stretched across it. After deflation, the expanded segment was measured in situ and compared with its original length. Follow-up urography was performed, and the tissue was harvested and examined by a pathologist. The same procedure was performed in five pigs; however, in these animals, a segment of ureter was excised, and a ureteroureterostomy was performed, after the acute expansion.

RESULTS

We were able to achieve acute elongation of the expanded ureteral segment. The mean elongation was 31.3% in the rabbits and 32.0% in the pigs. An intravenous urogram (IVU) 6 weeks after the elongation showed a functioning kidney and a patent ureter. Histologic examination of the ureter within 24 hours after the expansion revealed that all segments were viable, the luminal epithelium was intact, and the muscular layers appeared normal. At 6 weeks, the expanded segment showed mild inflammatory changes, but the overall morphology, size, and cytology findings were similar to those of a normal control.

CONCLUSIONS

Acute ureteral elongation using a tissue expander is a new method of increasing ureteral length. It may be useful to cover defects that would need major operations with greater morbidity.

Escherichia coli promotes macrophage apoptosis

BACKGROUND

Escherichia coli is the bacterium most commonly isolated from the urine of patients with urinary tract infection (UTI). Recurrent episodes of UTI lead to renal interstitial scarring. In interstitial fibrosis and scarring, infiltration of mononuclear cells has been reported to play a key role.

MATERIALS AND METHODS

We evaluated the effect of two strains of E. coli--the pathogenic BH-5 and the plasmidless, nonfimbriated HB-101-on human monocyte and murine macrophage apoptosis.

RESULTS

E. coli BH-5 enhanced apoptosis in a time- and dose-dependent manner. It also promoted necrosis in a time- and dose-dependent manner. Strain HB-101 promoted monocyte apoptosis in a dose-dependent manner. However, the magnitude of HB-101-induced monocyte apoptosis was lower than BH-5-induced macrophage apoptosis.

CONCLUSION

The ability of E. coli to induce apoptosis may contribute to its virulence and play a role in renal interstitial scarring.

The in vitro bactericidal effect of microwave energy on bacteria that cause prostatitis

OBJECTIVES

We investigated the in vitro nonthermal effects of microwaves delivered from Prostatron 2.0 on Escherichia coli and Enterobacter cloacae.

METHODS

The fingers of powder-free, sterile gloves were ligated, and bacterial solutions were transferred into the remaining area of the glove. The gloves were then sealed using silk ligatures. One set of gloves was subjected to the microwave treatment while another set was placed in a temperature-matched waterbath to act as control samples. The gloves containing the treatment group were taped around the probe, at the site where microwave energy exits the probe. During the treatment period, the temperatures from the urethral probe and the rectal probe were carefully monitored.

RESULTS

The mean (+/-SD) energy delivered was 46.6 +/- 9.5 kJ (range 30.0 to 59.5) for the 10 trials on E. coli and colony counts in the experimental microwaved gloves decreased significantly compared with control samples (5.26 +/- 4.5 x 10(5) versus 10.16 +/- 9.3 x 10(5) CFU/mL, P = 0.02). For the experiments on E. cloacae the mean (+/-SD) energy applied was 38.5 +/- 12.5 kJ, and a significant decrease in colony counts of microwaved samples was also observed compared with controls (11.04 +/- 4.8 x 10(5) versus 20.08 +/- 10.1 x 10(5) CFU/mL, P = 0.004).

CONCLUSIONS

Microwave energy, delivered from Prostatron 2.0, independent of heat production has an in vitro bactericidal effect on laboratory-cultured E. coli and E. cloacae.

Endopyelotomy for horseshoe and ectopic kidneys

PURPOSE

We report our experience with endopyelotomy for horseshoe and ectopic kidneys in the largest series to date to our knowledge, and discuss the technical modifications adopted to perform successfully percutaneous antegrade endopyelotomy.

MATERIALS AND METHODS

From September 1987 to April 1996, 4 patients with horseshoe and 5 with ectopic kidney underwent percutaneous antegrade endopyelotomy for symptomatic ureteropelvic junction obstruction. The percutaneous puncture was made more posteromedial and the ureteropelvic junction was incised lateral. A retrograde percutaneous access tract was created under laparoscopic guidance in pelvic kidneys.

RESULTS

The operative procedure was performed uneventfully in all patients with no major bleeding, pleural effusion or visceral perforation. The stents were removed at 6 weeks, and an excretory urogram was performed at 2 weeks, 6 months and yearly thereafter. In 2 patients (22%) with severe hydronephrosis, poor renal function and a long ureteral stricture surgical treatment failed immediately. The remaining 7 patients (78%) had long lasting clinical and radiographic success with a mean followup of 62 months.

CONCLUSIONS

Percutaneous antegrade endopyelotomy, with a few technical modifications, is a safe and effective treatment for ureteropelvic junction obstruction associated with horseshoe and ectopic kidneys.

Endopyelotomy after failed pyeloplasty: the long-term results

PURPOSE

Endopyelotomy has been proposed as a technique to treat ureteropelvic junction obstruction after failed open pyeloplasty. However, to our knowledge no long-term results of this treatment have been reported. We report the long-term followup of a cohort of patients in whom pyeloplasty failed and who subsequently were treated with endopyelotomy.

MATERIALS AND METHODS

From January 1985 to February 1996, 72 patients in whom open surgical pyeloplasty failed were treated with percutaneous endopyelotomy. Mean patient age was 35 years (range 5 to 82). The interval between pyeloplasty and subsequent failure ranged from 2 months to 30 years (mean 57 months). The major presenting symptoms were pain in 82% of cases, fever and urinary tract infections in 37.5%, stone formation in 25% and gross hematuria in 21%.

RESULTS

Antegrade endopyelotomy using a hooked knife was performed in all patients with no unusual difficulty and minimal complications. A total of 63 patients (87.5%) had long lasting clinical and radiographic treatment success after a mean followup of 88.5 months. Of the 9 endopyelotomy failures (12.5%) 7 (77.8%) were detected immediately after stent removal at 6 weeks, 1 (11.1%) at 6 months and 1 (11.1%) at 10 months postoperatively (mean failure interval 3.3 months). The failures were corrected with repeat endopyelotomy in 1 patient, pyeloplasty in 3, ileal interposition in 1 and nephrectomy in 4.

CONCLUSIONS

Endopyelotomy is the treatment of choice for recurrent ureteropelvic junction obstruction after failed pyeloplasty, with a high and sustained long-term success rate and no reported new failures after 1-year followup. Furthermore, endopyelotomy is technically easier with less morbidity than repeat open pyeloplasty.

Endopyelotomy for horseshoe and ectopic kidneys

PURPOSE

We report our experience with endopyelotomy for horseshoe and ectopic kidneys in the largest series to date to our knowledge, and discuss the technical modifications adopted to perform successfully percutaneous antegrade endopyelotomy.

MATERIALS AND METHODS

From September 1987 to April 1996, 4 patients with horseshoe and 5 with ectopic kidney underwent percutaneous antegrade endopyelotomy for symptomatic ureteropelvic junction obstruction. The percutaneous puncture was made more posteromedial and the ureteropelvic junction was incised lateral. A retrograde percutaneous access tract was created under laparoscopic guidance in pelvic kidneys.

RESULTS

The operative procedure was performed uneventfully in all patients with no major bleeding, pleural effusion or visceral perforation. The stents were removed at 6 weeks, and an excretory urogram was performed at 2 weeks, 6 months and yearly thereafter. In 2 patients (22%) with severe hydronephrosis, poor renal function and a long ureteral stricture surgical treatment failed immediately. The remaining 7 patients (78%) had long lasting clinical and radiographic success with a mean followup of 62 months.

CONCLUSIONS

Percutaneous antegrade endopyelotomy, with a few technical modifications, is a safe and effective treatment for ureteropelvic junction obstruction associated with horseshoe and ectopic kidneys.

Necrosis of the urethra and tissue sloughing: a delayed complication after transurethral microwave thermotherapy

Transurethral microwave thermotherapy is a minimally invasive treatment for benign prostatic hyperplasia designed to destroy hyperplastic tissue without damaging the urethra. We present an unexpected complication of prostatic urethral necrosis and tissue sloughing after thermotherapy and discuss its possible cause.

Percutaneous removal of stone from caliceal diverticulum in patient with nephroptosis

A novel method is introduced for percutaneous stone extraction from a lower pole caliceal diverticulum in a patient with nephroptosis, also known as a floating kidney. The patient was fully recovered and asymptomatic at 2 months postoperatively with her kidney fixed in the flank position.

Transurethral microwave thermotherapy for management of benign prostatic hyperplasia: a single-institution experience

OBJECTIVES

This is the first and largest single institution retrospective study in the United States to examine the effects of transurethral microwave thermotherapy (TUMT) for the treatment of benign prostatic hyperplasia (BPH).

METHODS

From September 1996 to June 1997, 78 men with moderate to severe symptomatic BPH were treated with the Prostatron at our institution. Patient age ranged from 52 to 85 years. Prostate volume ranged from 23 to 110 cc, and mean total energy applied during the treatment was 156.17 kJ. Patients were re-evaluated at 3 months and were asked to answer a questionnaire regarding their opinion about the treatment.

RESULTS

At 3 months there was a significant decrease in mean symptom score from 19.6 to 11.2 (P <0.0001). Mean peak flow rate increased from 8.5 to 12.8 mLs (P <0.0001). Mean postvoid residual urine decreased from 56.8 to 22.0 mL (P <0.0001). We did not observe any severe complications. Unlike prior studies, we removed the Foley catheter, and patients performed clean intermittent catheterization (CIC) when necessary. There was no significant differences in subjective and objective parameters between these patients and those who did not need CIC. Patient opinion about the treatment was not affected by CIC. About two thirds (67.2%) of the patients in the study group were satisfied with the results of treatment, and 60.3% would undergo the same procedure again.

CONCLUSIONS

TUMT of the prostate is an effective, safe, and acceptable form of treatment for patients with BPH. Longer follow-up is needed to examine the durability of TUMT treatment.