Chemolysis of urinary calculi.

Irrigant chemolysis was developed to collaborate with open surgery, removing the residual fragments. With the worldwide diffusion of the procedures performed by the endourologist in the early 1980s and the present availability of ESWL, however, direct irrigation of stones has a reduced field of influence even as an adjunctive measure. Urologists have applied economic analysis to their clinical practices, and the findings related to irrigant chemolysis made this technique an unusual procedure. The cost to the providers of medical care, the burden on the patient in terms of suffering and loss of productivity, and the amount of time required to liberate the patient even partially from the stones make irrigant chemolysis an inauspicious scenario. In this era of cost containment and decreasing length of stay, it is increasingly difficult to justify hospital admissions for this form of therapy. Being simultaneously more expensive and less effective than the existing alternatives, local chemolysis should be discarded, except for special situations, such as patients at high risk for any surgical procedure. Oral chemolysis preserves reduced indications, for example as an adjuvant to an endourologic operation or ESWL in special situations. As long as urinary stones continue to afflict humans, chemolysis is likely to retain a limited but important role in their management.

Tissue expansion: a promising trend for reconstruction in urology.

To evaluate the role of the tissue expansion concept in reconstructive urology, the contemporary literature was reviewed, together with our own results with tissue expansion. The principle of tissue expansion has been applied in cases of bladder augmentation, ureteral dilation for the generation of indigenous tissue and subsequent ureterocystoplasties, ureteral elongation, and dilation of the renal pelvis, producing native tissue for the reconstruction of defects or strictures of the upper ureter. Even though the exact mechanism of action of mechanical strain in different tissues is not known, tissue expansion is a well-accepted technique that can amplify the armamentarium of reconstructive urologists for the management of defects along the urinary tract.

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.

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.

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.

[Endourologic treatment of transitional cell carcinoma of the upper urinary tract]. / Trattamento endourologico del carcinoma a cellule transizionali delle alte vie urinarie.

Nephrourete-rectomy with excision of a bladder cuff has been the standard treatment of the upper urinary tract transitional cell carcinoma. The very indolent behavior (GI, II, Ta, T1) of more than 50% and up to 82% of the upper urinary tract tumors treated with nephroureterectomy in different series in conjunction with the advent of sophisticated endourological techniques have permitted in certain cases alternative treatments using a conservative approach with either ureteropyeloscopy or percutaneous access. Ureteroscopy is reserved for ureteral tumors and small, simple tumors of the renal pelvis (< 1.5 cm) while large or multiple tumors of the renal pelvis are approached in a percutaneous way. During 14 years 64 patients with transitional cell carcinoma of the upper urinary tract were treated percutaneously at our department at Long Island Jewish Medical Center, 15 (23.5%) with grade I, 26 (40.6%) with grade II and 23 (35.9%) with grade III and IV. After a mean follow-up of 51 months, percutaneously treated patients had a tumor specific survival of 85.6%, being 100% for GI tumors, 96.1% for GII and 60.8% for GIII. Recurrence of grade I tumors were observed in 20%, 26.9% for grade II and 56.5% for Grade III. In conclusion, with a rigorous follow-up transitional cell carcinoma of the upper tract with low and moderate grades (GI, GII, Ta, T1) can be treated endorologically even in the presence of a normal contralateral kidney with low morbility and a long term efficiency comparable to a nephroureterectomy. An elective endorologic management for GIII tumors is not recommended. Endoscopic conservative surgery can be offered when the criteria of good prognosis are found for Ta (such as absence of carcinoma in situ, presence of diploidy, low p53 expression and a single tumor) and in the cases of a solitary kidney or chronic renal insufficiency or for poor surgical candidates for T1. Patients with stage T2-T3 should be offered a nephroureterectomy.

[Percutaneous treatment of calculosis in caliceal diverticulosis: 13-year experience]. / Trattamento percutaneo della calcolosi nei diverticoli caliciali: 13 anni di esperienza.

We report our experience with the composition and management of caliceal diverticular stones for the past 13 years at our institution. Fourty patients with caliceal diverticular stones were treated percutaneously at Long Island Jewish Medical Center. The size of the diverticula ranged from 1 to 4.8 cm, with a mean size of 2.27 cm. The stone size ranged from 0.2 to 4.5 cm in diameter with an average of 1.7 cm. Twenty patients underwent a metabolic evaluation. Follow-up ranged from 8 months to 140 months with a mean of 72.5 months. We achieved a stone free rate of 95%. All 40 patients were free of pain and infection. The chemical composition of stones was identified in 38 patients. Twelve patients were found to have mainly calcium phosphate stones, 16 mainly calcium oxalate stones, 7 mainly uric acid stones and 3 were found with milk of calcium in their diverticulum. Thirty-five patients had complete resolution of their diverticula with normal urograms. The remaining 5 patients had at least 50% diminution of the diverticulum size. No one of the latter patients was found to have stone recurrence. Metabolic evaluation of the 40 patients showed in the 75% of the cases any metabolic abnormality, an absorptive hypercalciuria type II in two patients (10%), hyperuricosuric hypercalciuria in two cases (10%) and hyperoxaluria in one (5%). Percutaneous management of caliceal diverticular stones is a safe and effective modality compared to the existing alternative procedures reported in the literature.

Percutaneous endopyelotomy.

OBJECTIVES: During the past 10 years, numerous reports around the world have documented the safety and success rate of antegrade endopyelotomy. We describe the classic endopyelotomy in conjunction with some new alternatives for making the incision. TECHNICAL CONSIDERATIONS: Antegrade endopyelotomy is performed through the 0.5-in. incision of the percutaneous nephrostomy created by way of an upper or middle calix. Using the hook-shaped cold knife, an endopyelotome is positioned, and the entire procedure can be performed under direct vision, which determines the exact position, depth, and extent of the incision. The ureteropelvic junction (UPJ) obstruction is incised in a posterolateral position, and the hook is withdrawn from the proximal ureter. Using nephroscopic scissors, a small full-thickness puncture is made into the renal pelvis and then the scissors is opened, under constant visual control, until it reaches the peripelvic space. The section of the pelvic wall is completed with the scissors running through the UPJ, without any interchange of the nephroscope. A holmium laser has been also used, with the 365-microm fiber introduced through a stent-pusher. Under direct vision, the UPJ is incised with fiber, permitting observation and coagulation of bleeding from small vessels. After the procedure, either a 14-8.2F endopyelotomy stent or a 14-7F tapered endoureterotomy stent is placed over the guidewire. CONCLUSIONS: Percutaneous antegrade endopyelotomy is a safe and effective treatment of UPJ obstruction for most patients, regardless of the method used to perform the incision.

Caliceal diverticular calculi: is there a role for metabolic evaluation?

PURPOSE: We report our experience with the treatment and incidence of metabolic abnormalities in patients presenting with caliceal diverticular stones. MATERIALS AND METHODS: We retrospectively evaluated 49 patients with caliceal diverticular stones (group 1) and 44 with simple renal stones (group 2). Each group successfully underwent percutaneous treatment. Mean stone size was 1.7 and 2.5 cm. in groups 1 and 2, respectively. Metabolic evaluation was available in 25 group 1 and 22 group 2 patients. Mean followup was 73.2 and 70. 8 months, respectively. RESULTS: We achieved a stone-free rate of 95. 9% in group 1 and 100% in group 2. There was no metabolic abnormality in 75% of the group 1 patients, while 12% had type II absorptive hypercalciuria, 8% hyperuricosuric hypercalciuria and 4% hyperoxaluria. There were no metabolic abnormalities in 22.7% of the group 2 patients, while 9%, 18% and 9% had types I to III absorptive hypercalciuria, respectively, 13.6% hyperuricosuric hypercalciuria, 13.6% hyperoxaluria, 4.5% hypocitruria and 9% type II absorptive hypercalciuria associated with hypocitruria. CONCLUSIONS: Our results reveal a low incidence of associated metabolic abnormalities in patients with caliceal diverticular stones. Thus, we believe that metabolic abnormalities do not promote caliceal diverticular calculous formation.

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.

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.

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.