Tc-99m-labeled RBC scintigraphy and splenic hemangioma

PURPOSE

The aim of this study was to assess the diagnostic value of RBC scintigraphy in the evaluation of possible splenic hemangioma.

MATERIALS AND METHODS

RBC scintigraphy was performed on a patient with an incidental finding of a splenic mass on computed tomographic scanning. Early and delayed planar and SPECT images were obtained.

RESULTS

Delayed images revealed blood pooling of the splenic mass. This finding is similar to the characteristics seen in RBC scintigraphy for hepatic hemangioma.

CONCLUSION

RBC scintigraphy may be useful in the evaluation of possible splenic hemangioma.

Efficiency and efficacy of different intracorporeal ultrasonic lithotripsy units on a synthetic stone model

PURPOSE

The efficiency and efficacy of the available intracorporeal ultrasonic lithotripters were compared in a stone model experiment.

MATERIALS AND METHODS

Plaster of Paris (POP) stone phantoms having ratios of 1:1, 1.5:1, and 2:1 with water were fabricated into cubes of various hardnesses weighing an average of 24.6 g. The stones were immersed in water in a plastic container, and continuous irrigation through a rigid nephroscope was used. Ultrasonic lithotripters from ACMI, Olympus, Storz, and Wolf manufacturers were evaluated for efficacy in breaking up the three POP concentrations. Time to complete stone fragmentation, occurrence of probe or tubing occlusion, and probe overheating were evaluated.

RESULTS

Efficiency of fragmentation and time to fragmentation of the Storz lithotripter were significantly different from those of the Wolf (p = 0.01 and p = 0.02, respectively) and ACMI (p = 0.001 and p = 0.02, respectively) lithotripters. Comparison of the efficiency of fragmentation and time to fragmentation of the ACMI and Wolf lithotripters showed significant differences (p = 0.005 and p = 0.03, respectively) in favor of the Wolf device. The Olympus lithotriptor resulted in incomplete fragmentation of phantoms of all POP concentrations.

CONCLUSION

The Storz ultrasonic lithotriptor was found to have the lowest fragmentation time and highest efficiency in the fragmentation of phantom stones.

Endopyelotomy in poorly functioning kidney: is it worthwhile?

BACKGROUND

Endopyelotomy is a minimally invasive surgical alternative for primary ureteropelvic junction (UPJ) obstruction. However, its success in poorly functioning kidneys is controversial.

PATIENTS AND METHODS

In this retrospective study, 34 endopyelotomies performed on poorly functioning kidneys between January 1993 and December 1997 were reviewed. Of these, 13 patients had a glomerular filtration rate (GFR) <15 mL/min (Group I) and 21 had a GFR of 15 to 25 mL/min (Group II). All the patients insisted on endopyelotomy to avoid open surgery. Antegrade endopyelotomy was performed by the twin guidewire rail technique with a cold knife. An indwelling stent was kept for 2 to 6 weeks. Patients were followed up with assessment of symptoms and diuretic renograms at 3, 6, and 12 months postoperatively.

RESULTS

Endopyelotomy was considered successful in 8 of 13 patients (62%) in Group I. Success was achieved in 19 of 21 patients (90%) in Group II.

CONCLUSION

Endopyelotomy can be performed for improvement of symptoms. Stabilization or improvement in GFR is less pronounced in poorly functioning kidneys with primary UPJ obstruction.

Prognostic factors for persistent distal renal tubular acidosis after surgery for posterior urethral valve

Risk factors, including age at presentation, age at surgery, time between presentation and surgery, urodynamic abnormalities, and vesicoureteric reflux, were prospectively studied for the development of distal renal tubular acidosis (DRTA) before surgery and persistent DRTA after surgery in 24 boys with posterior urethral valve (PUV) with normal serum creatinine levels. DRTA was persistent in 11 of 17 boys (65%) at the end of follow-up after intervention. For the development of DRTA before surgery, only a longer time between presentation and surgery (intervening period) turned out to be a significant risk factor on multivariate analysis (beta = -0.13; P = 0.04). Boys with persistent DRTA after surgery had older age at presentation (P = 0.03), older age at surgery (P = 0.001), a longer intervening period (P = 0.0007), and bilateral or severe unilateral reflux (P = 0.04) before surgery. On univariate logistic regression, age at surgery (beta = -0.07; P = 0.04) and intervening period (beta = -0.13; P = 0.02) were found to be significant risk factors for persistent DRTA, but on multivariate analysis, only intervening period was found to be significant (beta = -0.13; P = 0.02). A delay in intervention after noticing voiding symptoms can predict a high incidence of DRTA before intervention and persistent DRTA after surgery in boys with PUV.

Acute urinary retention: defining the need and timing for pressure-flow studies

OBJECTIVE

To investigate the utility of "late" pressure-flow studies in predicting the outcome of prostatectomy for acute urinary retention.

PATIENTS AND METHODS

Fifty-eight patients with acute urinary retention were prospectively assessed using the International Prostate Symptom Score and pressure-flow studies at a median (range) of 24 (13-60) days after the episode of retention, and before transurethral resection of the prostate. Bladder outlet obstruction and bladder contractility were graded using a modified adaptation of Schäfer's passive urethral linear resistance relation.

RESULTS

Fifty-six (97%) patients generated a voluntary detrusor contraction, with a mean (range) detrusor pressure at maximum flow of 72.7 (5-144) cmH2O, and 43 (75%) patients were deemed to be obstructed. Eight (16%) patients failed to void after prostatectomy and required clean intermittent catheterization. There were statistically significant differences between successful and unsuccessful patients in mean (SD) age, at 66.30 (6.9) vs 78.8 (2.6) years (P = 0.001), detrusor instability (49% vs 0%, P = 0.01), inability to void during pressure study (8% vs 75%, P = 0.001), and maximal detrusor pressure in the voiding phase, at 80 (36.0) vs 19 (11.2) cmH2O (P = 0.001).

CONCLUSIONS

In patients with acute urinary retention, pressure-flow studies undertaken after a period of adequate bladder rest (> 3 weeks) are useful in predicting the surgical outcome. Old age, absence of bladder instability, inability to void during the pressure-flow study and a maximal detrusor pressure of < 20 cmH2O are associated with a poor outcome after prostatectomy.

Endopyelotomy failure is associated with reduced urinary transforming growth factor-beta1 levels in patients with upper urinary tract obstruction

BACKGROUND AND PURPOSE

We previously demonstrated that obstructed ureteropelvic junction (UPJ) segments from patients who had secondary pyeloplasty after endopyelotomy failure expressed transforming growth factor-beta1 (TGF-beta1) at levels significantly lower than patients who had primary pyeloplasty. In order to determine whether these differences in secreted TGF-beta1 are detectable preoperatively in the urine, the TGF-beta1 concentration of urine from patients undergoing endopyelotomy was determined and compared with that from subjects without urologic disease.

MATERIALS AND METHODS

Bladder and renal pelvic urine from the obstructed side was obtained from patients (N = 34) undergoing primary endopyelotomy for UPJ obstruction. Bladder urine was also obtained from sex- and age-matched patients (N = 26) having no evidence of urinary tract obstruction. The TGF-beta1 concentration was determined by ELISA and normalized to the creatinine concentration.

RESULTS

The bladder urine TGF-beta1 concentration was significantly (P < 0.02) higher in patients with UPJ obstruction (86.1+/-20.5 pg/mg of creatinine) than in those without obstruction (29.7+/-8.0 pg/mg creatinine). The TGF-beta1 concentration in the bladder urine of patients who underwent endopyelotomy and later returned because of UPJ obstruction (25.7+/-12.3 pg/mg of creatinine; N = 6) was not significantly different from the value in unobstructed patients but was significantly lower (P < 0.01) than in patients for whom endopyelotomy was successful (100+/-24.29 pg/mg of creatinine; N = 28). The renal pelvic urinary TGF-beta1 concentration was higher in patients for whom endopyelotomy was successful (772+/-490.1 pg/mg of creatinine) than in patients who underwent endopyelotomy and later returned because of UPJ obstruction (126.1+/-41.9 pg/mg of creatinine).

CONCLUSIONS

These data suggest that preoperative concentration of TGF-beta1 in the bladder urine of patients with UPJ obstruction who fail endopyelotomy is not significantly different from that in subjects with no urologic disease and significantly lower than in those patients for whom endopyelotomy is successful. Thus, the preoperative bladder urine concentration of TGF-beta1 may assist in selecting patients for this operation, although further investigation is necessary.

Studies on the mechanism of action of a targeted chemotherapeutic drug in living cancer cells by two photon laser scanning microspectrofluorometry

In this study, we present a spectroscopic study of the entry pattern of a chemotherapeutic drug (AN-152) and its carrier hormone ([D-Lys(6)]LH-RH) into living cancer cells, with the help of our two-photon probes and a home-built localized microspectrofluorometer coupled with two photon laser scanning microscope (TPLSM). Due to the inherent localization ability of TPLSM, we were able to identify the drug and carrier location in different compartments of the cancer cells in vitro. The apparent doxorubicin-assisted nucleic accumulation of AN-152 suggests a possible nuclear action of the drug on cell proliferation.

Prognostic significance of distal renal tubular acidosis in posterior urethral valve

The prognostic significance of distal renal tubular acidosis (DRTA) in the development of overt nephropathy (ON) in children with posterior urethral valves (PUV) is not clear. This condition was studied prospectively in 22 children with posterior urethral valve (PUV), with normal renal function. Prior to surgery, the children with ON had a higher incidence of bilateral reflux (P=0.006), but the difference was not significant for age at surgery (P=0.31), duration of voiding symptoms prior to surgery (P=0.30), presence of DRTA (P=0.35) and bladder abnormalities (P=0.27), with none of these factors being significant on logistic regression analysis. At the end of the follow-up, after surgery, age at surgery (P < or = 0.0001), duration of voiding symptoms prior to surgery (P < or = 0.0003), persistent DRTA (P=0.0001) and persistent bladder dysfunction (P=0.02) after surgery were significantly higher in children with ON. On univariate logistic regression analysis, age at surgery (P=0.009), duration of voiding symptoms prior to surgery (P=0.01), persistent DRTA (P=0.002) and persistent bladder abnormalities (P=0.03) after surgery were significant for ON after surgery, but on stepwise multivariate logistic regression analysis only persistent DRTA (P=0.002) turned out to be significant. We conclude that persistent DRTA after surgery can predict overt nephropathy in children with PUV after surgery.

Modified bulbar urethral sling procedure for the treatment of male sphincteric incontinence

BACKGROUND AND PURPOSE

Urinary incontinence secondary to intrinsic sphincter deficiency is a debilitating condition for the patient and an ordeal for the urologist. Because of the complexity of reconstructive surgical techniques and the prohibitive cost of the prosthetic devices used, there is a need for a simple procedure. We herein report our experience in managing urinary incontinence secondary to sphincteric incompetence in nine consecutive patients using a modified bulbar urethral sling procedure over a period of 2 years.

PATIENTS AND METHODS

In eight patients, the incontinence followed open prostatectomy or transurethral resection for benign prostatic hyperplasia, and one patient had incontinence following fulguration of posterior urethral valves. Our procedure uses bolsters that are suspended from the rectus fascia, and a hammock made of a folded Dacron patch is placed beneath the bulbospongiosus muscle to form a sling.

RESULTS

All patients were continent postoperatively, with only mild stress leakage in the erect posture, during a mean follow-up of 12.2 months (range 6-22 months) and required one or two improvised pads per day to remain continent during the daytime. Persistent perineal infection necessitated removal of the sling in one patient. One patient required clean intermittent catheterization for a short period postoperatively.

CONCLUSION

This modified bulbar urethral sling procedure is a simple yet effective method to treat sphincteric deficiency of any cause.

Influence of lead in soil on mycorrhizal development and plant growth of Cyamopsis tetragonoloba (Linn.) Taub

Growth of C. tetragonoloba suffered with increase in concentration of Pb in soil. Plant biomass declined significantly at concentrations above 60 ppm of Pb. Roots showed more pronounced impact as compared to shoots. At highest applied concentration of lead (100 ppm), fresh weight of fruits decreased by 33% and dry weight by 52% as compared to control. No significant impact was noticed on the development of mycorrhiza at lower concentrations (15-45 ppm) of lead contamination. At higher concentrations of Pb (60 and 75 ppm), there was a decrease in VAM colonization. VAM hyphae had irregular size and terminated abruptly in outer cortex of root. Number of VAM fungal spores in rhizosphere also decreased with increase in the edaphic Pb concentration.

Transitional-cell carcinoma of the renal pelvis: ureteroscopic and percutaneous approach

There are a variety of publications advocating the ureteroscopic or the percutaneous approach for the treatment of transitional cell carcinoma of the renal pelvis. The diagnostic tool of choice for the upper urinary tract and collecting system is the flexible ureteroscope. One of the major concerns about ureteroscopic management of renal disease initially was the lack of flexibility of the instruments and therefore the inability to deal with demanding sites. The advent of new ureteroscopic techniques, as well as the continuous evolution of the technology, have paved the way for safe and effective access to the upper urinary tract. In the hands of an experienced urologist, such procedures can provide reliable treatment options for small upper urinary tract lesions. Coupling minimal morbidity with ever-improving optics and flexibility, the ureteroscope of today leaves no area of the urinary tract unseen. In patients with bulky tumors or in whom easy access and resection is not possible ureteroscopically, the percutaneous approach to the renal pelvis, although more invasive, provides a better working environment. Clearly, the most difficult aspect of ureteroscopic access to the lower pole is not just visibility but the loss of deflection caused by passage of various instruments through the working channel. Direct access via percutaneous approach with a large resectoscope avoids these problems.

Ureteral reconstruction: small intestine submucosa for the management of strictures and defects of the upper third of the ureter

PURPOSE

We evaluated the effectiveness of small intestine submucosa in ureteral reconstruction.

MATERIALS AND METHODS

We report an experimental study in 6 female pigs weighing between 50 and 60 pounds. The animals were anesthetized, midline laparotomy was performed and two-thirds of the diameter of the upper third of the left ureter were incised parallel to the ureteral axis, leaving intact only a third of the ureteral wall for a segment of 7 cm. A 5Fr double-J*; stent was positioned to secure patency at all times. The created gap was then bridged with an small intestine submucosa patch in a cylindrical format, which was subsequently sutured to the proximal and distal ureteral segment. The right ureter served as our control and simple intubated Davis ureterotomy was performed.

RESULTS

All animals survived the whole followup of 7 weeks. Histologically there was evidence of epithelial regeneration along the segments reconstructed with small intestine submucosa, supported by a well vascularized collagen and smooth muscle background. There was no evidence of foreign body reaction to the graft material. In vivo patency was confirmed by retrograde pyelography in the bridged ureters 7 weeks after the initial procedure. All the ureters without an small intestine submucosa bridge had ureteral stenosis without evidence of epithelial regeneration.

CONCLUSIONS

The use of small intestine submucosa is a novel, effective material for the scaffolding of ureteral defects and/or strictures of the upper ureteral segment in the pig model.

Electrically active axons degenerate when exposed to nitric oxide

Axonal degeneration is a major cause of permanent deficit in inflammatory neurological diseases such as multiple sclerosis. Axons undergo degeneration specifically at the site of the inflammatory lesions, suggesting that locally produced inflammatory factors mediate the phenomenon. One such factor is nitric oxide (NO), which we have previously reported can cause reversible conduction block in axons. Here we confirm these observations and extend them to show that axons exhibit the early stages of wallerian degeneration if they are conducting impulses at physiological frequencies while they are exposed to the low micromolar concentrations of NO that are likely to occur at sites of inflammation. Rat dorsal roots were concurrently exposed in vivo to both NO and sustained impulse activity at 1, 50, or 100 Hz. Although our in vivo observations necessarily focused on the more acute responses, morphological examination of exposed roots at the end of the recording period revealed nodal and paranodal changes consistent with acute wallerian degeneration in roots stimulated at 50 or 100 Hz. This interpretation was confirmed in a few experiments that were prolonged to permit more obvious indicators of degeneration to develop. In these experiments the formation of myelin ovoids and frank axonolysis occurred in more than 95% of fibers. Roots stimulated at only 1 Hz appeared normal. We propose that the combination of normal impulse traffic and NO at sites of inflammation may cause axonal degeneration and that electrical activity may therefore be an important factor in causing permanent disability in patients with neuroinflammatory disorders.

Comparison of symptoms related to positioning of double-pigtail stent in upper pole versus renal pelvis

PURPOSE

This study was a comparison of the symptomatology associated with placement of the upper coil of a double-pigtail stent in the upper pole or the renal pelvis.

PATIENTS AND METHODS

A prospective study with 40 patients was performed. In 20 patients, the stent was placed in the upper pole (Group A) and in another 20 patients (Group B) in the renal pelvis. A questionnaire was addressed to all patients before the removal of the stent concerning the presence and severity of flank pain (using a standardized 10-point scale), the presence and severity of urinary urgency (using a standardized 10-point scale), the presence of dysuria, and quality of life with the stent in place.

RESULTS

Flank pain was present in 17 (85%) and 15 (75%) patients in Groups A and B, respectively. The average severity of flank pain was 4.3 (range 0-7) and 4.5 (range 0-10) in Group A and B, respectively (p = 0.764). Urinary urgency was present in 13 (65%) and 15 (75%), patients in Group A and B, respectively. The average severity of urgency was 3.1 (range 0-7) and 5.3 (range 0-10) in Group A and B, respectively (p = 0.037). Dysuria was present in 4 (20%) and 13 (65%), and the average quality of life score was 2.5 and 3.05 in Group A and B, respectively (p = 0.04).

CONCLUSION

Positioning of the proximal end of the double-pigtail stent in the upper pole of the kidney appears to be better tolerated by patients than is the standard insertion in the renal pelvis.

In vitro bactericidal effect of a modified thermal Nitinol electrode

PURPOSE

A standard electrode surgical generator connected to a Nitinol coil was used in vitro to evaluate whether the generated electromagnetic energy had any bactericidal effect on Escherichia coli.

MATERIALS AND METHODS

The ATCC 259222 E. coli strain was used. We mixed 135 mL of a 1.5% non-nutritive agar with 15 mL of a 10(6) CFU/mL inoculum and transferred it to gas-sterilized plastic containers lined with aluminium foil. A 22F cylindrical shape was cut from the center of the agar, and a Nitinol coil was placed in that space and connected to a standard electrode surgical generator. Electrical energy was then applied from 5 to 25 V at 5-V increments. Temperatures were measured with two thermocouples placed in the middle and periphery of each agar. The treatment was stopped when the temperature at the middle thermometer reached 50 degrees C. The control group was not treated and was embedded in a water bath at 45 degrees C. Three 3 x 7-mm pieces were sliced from the inner to the outer part of the agar and processed, and colony counts were performed.

RESULTS

We observed statistically significant deleterious effects on E. coli in all three zones when the treatment voltage was 15 and 20. When the potential was raised to 25 V, we observed a significant result only in the core zone. The treatment duration was 50 minutes for 5 and 10 V, 45 minutes for 15 V, 15 minutes for 20 V, and 10 minutes for 25 V.

CONCLUSION

The bactericidal effect was mainly in the central area, decreasing linearly toward the periphery, and was related to the temperature reached during activation of the electrical generator. These results were disappointing with regard to the utility of Nitinol stents to treat bacterial prostatitis.

Regulatory mechanisms controlling expression of the DAN/TIR mannoprotein genes during anaerobic remodeling of the cell wall in Saccharomyces cerevisiae

The DAN/TIR genes of Saccharomyces cerevisiae encode homologous mannoproteins, some of which are essential for anaerobic growth. Expression of these genes is induced during anaerobiosis and in some cases during cold shock. We show that several heme-responsive mechanisms combine to regulate DAN/TIR gene expression. The first mechanism employs two repression factors, Mox1 and Mox2, and an activation factor, Mox4 (for mannoprotein regulation by oxygen). The genes encoding these proteins were identified by selecting for recessive mutants with altered regulation of a dan1::ura3 fusion. MOX4 is identical to UPC2, encoding a binucleate zinc cluster protein controlling expression of an anaerobic sterol transport system. Mox4/Upc2 is required for expression of all the DAN/TIR genes. It appears to act through a consensus sequence termed the AR1 site, as does Mox2. The noninducible mox4Delta allele was epistatic to the constitutive mox1 and mox2 mutations, suggesting that Mox1 and Mox2 modulate activation by Mox4 in a heme-dependent fashion. Mutations in a putative repression domain in Mox4 caused constitutive expression of the DAN/TIR genes, indicating a role for this domain in heme repression. MOX4 expression is induced both in anaerobic and cold-shocked cells, so heme may also regulate DAN/TIR expression through inhibition of expression of MOX4. Indeed, ectopic expression of MOX4 in aerobic cells resulted in partially constitutive expression of DAN1. Heme also regulates expression of some of the DAN/TIR genes through the Rox7 repressor, which also controls expression of the hypoxic gene ANB1. In addition Rox1, another heme-responsive repressor, and the global repressors Tup1 and Ssn6 are also required for full aerobic repression of these genes.

Escherichia coli-human uroepithelial cell interaction products enhance fibroblast migration and matrix accumulation

BACKGROUND AND PURPOSE

Urinary tract infection has been associated with renal interstitial scarring and ureteral wall fibrosis. The mechanism of progression of scarring despite attenuation of the primary insult is not clear. We examined the role of the products of the interaction between Escherichia coli and human uroepithelial cells (HUC-EC-S) on the migration of fibroblasts, as well as their matrix synthesis.

MATERIALS AND METHODS

We evaluated the effect of HUC-EC-S (concentration of 10%, 15%, and 25%) on the migration of fibroblasts across a filter in a modified Boyden chamber. To determine the role of transforming growth factor-beta and MCP-1, we studied the effect of anti-TGF-beta and anti-MCP-1 antibodies on interaction product-induced fibroblast migration. The effect of HUC-EC-S on fibronectin and collagen I accumulation was studied by the Western blotting.

RESULTS

Bacterial-HUC interaction products enhanced (P < 0.001) migration of fibroblasts compared with uroepithelial interaction product (HUC-S). Anti-TGF-beta and anti-MCP-1 antibodies partly inhibited (P < 0.001) the HUC-EC-S-induced fibroblast migration. Also, HUC-EC-S-treated fibroblasts showed enhanced accumulation of fibronectin and collagen 1.

CONCLUSION

Escherichia coli-induced activation of HUC not only promotes migration of fibroblasts but also triggers matrix remodeling.

Laparoscopic ureteral reconstruction with small intestinal submucosa

PURPOSE

To evaluate the feasibility of laparoscopic ureteral reconstruction with small intestinal submucosa (SIS) in the pig ureter.

MATERIALS AND METHODS

Eight female pigs weighing between 25 and 30 kg were enrolled. After anesthesia was administered, a double-pigtail stent was inserted, the animals were moved to a lateral decubitus position, pneumoperitoneum was established, and three 10-mm ports were positioned. The ureter was opened longitudinally for 7 cm, and two thirds of the periphery of the upper third of the left ureter was excised. The SIS was anastomosed to the upper and distal ureteral segments with chromic 4-0 sutures. The double-pigtail stent was removed 6 weeks after the initial procedure, and retrograde pyelography was performed a week later to confirm the viability of the pelvicaliceal system.

RESULTS

The average duration of the procedures was 210 minutes (range 125-250 minutes). All animals survived the entire follow-up period of 7 weeks. Retrograde pyelography revealed a patent ureteral lumen, and no obstructive phenomena were observed. Histologically, the SIS-regenerated ureteral segments were remarkably similar to normal porcine ureters and were indistinguishable from neighboring tissue.

CONCLUSION

Laparoscopic ureteral reconstruction with SIS proved to be effective and technically feasible. The SIS seems to be an effective biodegradable scaffold, facilitating regeneration of host tissue.

Chronic expansion of the renal pelvis: a new method for reconstruction of upper ureteral defects

OBJECTIVES

To evaluate whether the dilated renal pelvis can be used as an autologous source for the surgical reconstruction of upper ureteral defects or strictures.

METHODS

In 7 female pigs, the renal pelvis was expanded by a percutaneously placed Council balloon catheter. Every other day for 4 weeks, the renal pelvis was progressively dilated with a bolus injection of saline and contrast medium, which allowed expansion of the renal pelvis to 70 to 75 mL. Four to six weeks after the initial intervention, 5 to 7 cm of the proximal ureter was resected in an open operation and replaced with a tubularized spiral flap made from the expanded renal pelvis. Three weeks later, the animals were killed, and the area of manipulation was resected for pathologic evaluation.

RESULTS

All animals reached the desired expansion of the renal pelvis, and in all cases, the spiral flap was fashioned and anastomosed to the distal ureteral segment, bridging the initial defect (mean length 7 cm). Two animals died from sepsis, 4 and 6 days after the spiral flap reconstruction. A viable ureteral lumen with a patent anastomosis and a functioning pelvocaliceal unit was observed on intravenous urography in all animals. The main histologic findings were a chronic inflammatory process with concomitant mucinous metaplasia and reactive atypia of the tubules.

CONCLUSIONS

The use of a balloon expander in the renal pelvis is a safe and effective technique for producing native tissue for the reconstruction of defects or strictures of the upper ureteral segment.

Do prostatic stents solve the problem of retention after transurethral microwave thermotherapy?

Temporary nonmetallic stents offer an alternative to an indwelling catheter for the management of voiding problems after heat-based therapies for benign prostatic hyperplasia. Patient comfort is improved, and they are able to void immediately after the procedure. Unlike a catheter, stents function on the principle of active drainage. Thus, a functioning detrusor muscle is imperative for stent success. Single-center clinical trials have reported encouraging results; however, predictable success criteria are yet to be established. Multicenter trial data are awaited.

Transurethral microwave thermotherapy for the treatment of prostatitis

The lethal action of microwaves on various microorganisms is well established and has been exploited in various clinical settings. Transurethral microwave thermotherapy (TUMT) has become a recognized modality for the treatment of prostatic diseases. Recently, it has been applied for the treatment of patients with nonbacterial prostatitis unresponsive to traditional therapeutic schemes. We review the current literature and present our recent encouraging experience with the in vitro bactericidal effect of microwaves on bacteria considered possible etiologic agents of prostatitis. Thus, we may consider the application of TUMT in patients with chronic bacterial prostatitis.

Stone recurrence after endopyelotomy

OBJECTIVES

The purpose of this study was to evaluate whether repair of the ureteropelvic junction (UPJ) obstruction reduces the incidence of stones in stone-forming patients with concurrent UPJ obstruction.

METHODS

We performed a retrospective study evaluating 90 patients with UPJ obstruction who underwent endopyelotomy and simultaneous stone extraction (group A) and 80 patients without UPJ obstruction who underwent only stone extraction (group B). Group A consisted of 52 men and 38 women with an average age of 54.4 years (range 15 to 82), and group B of 46 men and 34 women with an average age of 53.5 years (range 8 to 94). Metabolic evaluation was available in 47 patients of group A and 42 patients of group B.

RESULTS

We achieved a stone-free state in all patients of both groups. Stone recurrence was observed in 7 patients (8%) in group A and in 32 patients (40%) in group B. Nine of 47 patients (19%) in group A showed metabolic abnormalities. In group B we found 30 of 42 patients (71.4%) with metabolic abnormalities.

CONCLUSIONS

Our results suggest that correction of the anatomic obstruction facilitates the drainage of the previously entrapped urine, and thus decreases the incidence of recurrent urinary stone formation.