Arthur D. Smith

The Endourological Management of Complications Associated with Horseshoe Kidney

PURPOSEnHorseshoe kidneys are the most common renal fusion anomalies. Ureteropelvic junction obstruction, urolithiasis and renal malignancies are the most common complications that occur in this patient population. Endourological management of these complications has decreased perioperative morbidity. We identified the applications of minimally invasive surgery for treating complications secondary to horseshoe kidney.nnnMATERIALS AND METHODSnA comprehensive literature review of the different endourological approaches in the management of complications secondary to horseshoe kidney was performed using MEDLINE.nnnRESULTSnUreteropelvic junction obstruction can be managed by percutaneous endopyelotomy or laparoscopic pyeloplasty with good results. Small stones associated with horseshoe kidney are best managed by shock wave lithotripsy, while stones that have failed management by shock wave lithotripsy or are greater than 2 cm. are best managed percutaneously. All patients should undergo metabolic evaluation. Ureteroscopy or shock wave lithotripsy is associated with a higher residual stone rate than the percutaneous approach. Laparoscopic nephrectomy is a safe and feasible option for benign and malignant horseshoe kidney diseases.nnnCONCLUSIONSnEndourological techniques can be safe and effective for treating complications secondary to horseshoe kidney.

PRIMARY PERCUTANEOUS APPROACH TO UPPER URINARY TRACT TRANSITIONAL CELL CARCINOMA

The optimal approach to upper tract TCC remains to be redefined. A routine nephroureterectomy for every filling defect in the upper urinary system, even in the case of a normal contralateral kidney, constitutes an unnecessary mutilation in more than two thirds of the cases. Nephroureterectomy does not reduce the need for a long-term cystoscopic follow-up because of the high rate of bladder tumor recurrence that may happen years later after nephroureterectomy. Relying solely on radiography and cytology, lacking sensitivity and specificity, to recommend a nephroureterectomy is against the principles of oncologic surgery, especially now that preoperative histologic proof is easy to obtain endoscopically without compromising cancer control. Ureteroscopy, rigid and flexible, provides a complete assessment of the upper urinary system. Biopsy specimens taken with ureteroscopy may be sufficient for grading but less adequate for staging of the tumor. The authors reserve ureteroscopy for ureteral tumors and small (< 1.5 cm) single tumors of the renal pelvis. They approach large or multiple tumors of the renal pelvis percutaneously, in which a full histologic assessment is possible along with a complete resection of the tumor. The decision on the therapeutic approach is made only after the final pathologic report is reviewed. Grade I and grade II superficial disease (Ta, T1) can be treated endoscopically with minimal morbidity and with an efficiency comparable with the standard more invasive nephroureterectomy (Table 5). The indications for endourologic treatment in these cases can be extended safely beyond a solitary kidney or a high surgical risk to include any healthy individual with a normal contralateral kidney who is willing to commit to a rigorous lifelong follow-up. Patients with grade II T1 lesions require a more vigilant follow-up. For grade III Ta disease, more caution should be exercised in selecting these patients for elective endourologic management. When criteria of good prognosis are found, such as absence of carcinoma in situ, presence of diploidy, low p53 expression and a single-tumor, endoscopic management can be offered [table: see text] with a closer follow-up and resorting always to immediate nephroureterectomy at the first evidence of upstaging. Because of the high incidence of recurrence and progression, elective endourologic management for grade III T1 tumors is not recommended. Endoscopic conservative surgery still can be offered in the cases of a solitary kidney or chronic renal insufficiency or for poor surgical candidates. Patients with localized stages (T2, T3) TCC should be offered immediate nephroureterectomy. The authors do not expect adequate endoscopic extirpation with muscle invasive tumors. Although the tissue removed may include deep layers, deep resection is precluded by the thin renal pelvic wall and the associated risk for perforation. Patients with more extensive disease (T3, T4) have a bad prognosis regardless of the form of therapy. Achieving local control percutaneously while preserving as many nephrons as possible for the future chemotherapy can be a reasonable option.

URETERAL RECONSTRUCTION: SMALL INTESTINE SUBMUCOSA FOR THE MANAGEMENT OF STRICTURES AND DEFECTS OF THE UPPER THIRD OF THE URETER

PURPOSEnWe evaluated the effectiveness of small intestine submucosa in ureteral reconstruction.nnnMATERIALS AND METHODSnWe 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.nnnRESULTSnAll 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.nnnCONCLUSIONSnThe 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.

PERCUTANEOUS MANAGEMENT OF GRADE II UPPER URINARY TRACT TRANSITIONAL CELL CARCINOMA: THE LONG-TERM OUTCOME

PURPOSEnWe report the long-term outcome of our experience with percutaneous treatment of grade II upper urinary tract transitional cell carcinoma.nnnMATERIALS AND METHODSnA total of 61 patients with transitional cell carcinoma of the upper urinary tract were treated percutaneously between 1984 and 1998. Of the patients 24 (39%) had grade II disease. Immediate nephroureterectomy was performed due to muscle invasive disease in 2 patients, bleeding in 1 and inability to resect the whole tumor in 1. Percutaneous resection was the actual treatment in 15 patients with stage Ta and 5 with stage T1 disease.nnnRESULTSnRecurrence was noted in 5 patients (25%), including 3 (20%) with stage Ta tumors and 2 (40%) with stage T1 disease after a median followup of 48 months (range 9 months to 12 years). All stage Ta disease recurrences were superficial. In 1 patient with a stage T1 tumor invasive and metastatic disease developed. Disease specific survival was 95% overall, and 100% for stage Ta and 80% for stage T1 disease. No tumor seeding was detected along the percutaneous tract.nnnCONCLUSIONSnPercutaneous surgery has proved safe and effective in treating superficial grade II upper tract transitional cell carcinoma. Offering an endoscopic approach electively to healthy individuals with a normal contralateral kidney seems viable.

ENDOPYELOTOMY AFTER FAILED PYELOPLASTY: THE LONG-TERM RESULTS

PURPOSEnEndopyelotomy 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.nnnMATERIALS AND METHODSnFrom 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%.nnnRESULTSnAntegrade 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.nnnCONCLUSIONSnEndopyelotomy 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.

CROSSING VESSELS: Endourologic Implications

The controversy regarding the functional significance of vessels crossing at the ureteropelvic junction is not a new one, though this debate has been resurrected in recent years because of application of endourologic techniques to manage ureteropelvic junction (UPJ) obstruction. The principle limitation of endoscopic treatment of UPJ obstruction is the inferior success rate compared to open dismembered pyeloplasty. The influence crossing vessels may have in affecting both the success rates and complications of endoscopic treatment of UPJ obstruction has yet to be resolved. Crossing vessels may be important for two reasons: (1) they are a potential source of hemorrhage following endoscopic incision, and (2) they may play an etiologic role in UPJ obstruction and therefore may be a reason for failure of endoscopic techniques. This article reviews some of the historical aspects of crossing vessels and explores recent studies that are starting to shed some light on this controversial topic.

ENDOPYELOTOMY FOR HORSESHOE AND ECTOPIC KIDNEYS

PURPOSEnWe 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.nnnMATERIALS AND METHODSnFrom 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.nnnRESULTSnThe 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.nnnCONCLUSIONSnPercutaneous antegrade endopyelotomy, with a few technical modifications, is a safe and effective treatment for ureteropelvic junction obstruction associated with horseshoe and ectopic kidneys.

CALICEAL DIVERTICULAR CALCULI: IS THERE A ROLE FOR METABOLIC EVALUATION?

PURPOSEnWe report our experience with the treatment and incidence of metabolic abnormalities in patients presenting with caliceal diverticular stones.nnnMATERIALS AND METHODSnWe 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.nnnRESULTSnWe 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.nnnCONCLUSIONSnOur 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.

Matrix Modulates Uptake of Calcium Oxalate Crystals and Cell Growth of Renal Epithelial Cells

Handling of urinary crystals by renal epithelial and medullary interstitial cells may play an important role in the pathogenesis of renal stones and associated renal scarring. We examined the effects of calcium oxalate monohydrate (CaOM) crystals on the proliferative activity of renal tubular cells (opossum kidney) and renal medullary interstitial cells in culture. We also studied the impact of altered extracellular matrix on cell proliferation as well as on uptake of crystals by epithelial cells. Epithelial cells incubated with CaOM showed greater (p < 0.05) growth when compared with untreated cells (control, 10.5 +/- 1.1 versus CaOM, 16.6 +/- 1.6 x 10(6) cells per dish). the CaOM crystal-cell interaction also enhanced proliferation of interstitial cells (at 48 hours, control, 3.3 +/- 0.2 versus CaOM, 4.2 +/- 0.1 x 10(6) cells per dish, p < 0.02; at 72 hours, control, 3.6 +/- 0.3 versus 5.5 +/- 0.4 x 10(6) cells per dish, p < 0.01). Collagen, a constituent of extracellular matrix, inhibited (p < 0.01) proliferation of epithelial cells. Semiconfluent epithelial cells grown on collagen gels showed greater (p < 0.01) uptake of 45CaOM crystals when compared with uptake by cells grown on either uncoated (control) or albumin-coated plastic dishes (control, 979.9 +/- 51.1, albumin, 876.4 +/- 28.3, collagen gel, 1502.5 +/- 103.8 cpm per well). Epithelial cells grown to confluence on collagen gels also showed enhanced (p < 0.05) uptake of 45CaOM crystals. Reflectance microscopy as well as ultrastructural studies revealed intracellular localization of CaOM crystals. These results indicate that CaOM crystals stimulate the growth of both epithelial and interstitial cells. Enhanced growth of interstitial cells may also lead to increased synthesis of extracellular matrix. The latter may further modulate crystal uptake as well as cell growth of adjacent epithelial cells. These findings may be important in the development of nephrolithiasis and associated interstitial scarring.

The In Vitro Bactericidal Effect of Microwave Energy on Bacteria That Cause Prostatitis

OBJECTIVESnWe investigated the in vitro nonthermal effects of microwaves delivered from Prostatron 2.0 on Escherichia coli and Enterobacter cloacae.nnnMETHODSnThe 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.nnnRESULTSnThe 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).nnnCONCLUSIONSnMicrowave energy, delivered from Prostatron 2.0, independent of heat production has an in vitro bactericidal effect on laboratory-cultured E. coli and E. cloacae.