EXTRAPERITONEAL LAPAROSCOPIC PYELOPLASTY: A MULTICENTER STUDY OF 55 PROCEDURES

PURPOSE: We assessed the feasibility, reproducibility and morbidity of retroperitoneal laparoscopic pyeloplasty for ureteropelvic junction obstruction. MATERIALS AND METHODS: A total of 55 retroperitoneal laparoscopic pyeloplasties were performed at 3 institutions between September 1996 and May 2000 in 33 women and 21 men. Results were analyzed in regard to radiological assessment by excretory urography at 3 months, complications and hospital stay. RESULTS: We performed dismembered pyeloplasty in 48 cases and Fenger plasty in 7 cases. Crossing vessels were noted in 23 patients. The conversion rate was 5.4%. Mean operative time was 185 minutes (range 100 to 260), mean hospital stay was 4.5 days (range 1 to 14) and mean followup was 14.4 months (range 6 to 43.6). The overall complication rate was 12.7%. Complications in 7 patients included hematoma in 3, urinoma in 1, severe pyelonephritis in 1 and anastomotic stricture in 2 requiring open pyeloplasty at 3 weeks and delayed balloon incision at 13 months, respectively. Excretory urography in 50 patients and ultrasound in 4 showed decreased hydronephrosis in 88.9% at 3 months. Normal physical activity and absent pain were reported by 47 patients (87%) 1 month after surgery. CONCLUSIONS: Retroperitoneal laparoscopic pyeloplasty seems to be a valuable alternative to open pyeloplasty for ureteropelvic junction obstruction. The long-term outcome must be assessed before this procedure may be definitively validated.     

Stent failure in the management of malignant extrinsic ureteral obstruction: Risk factors

There is still controversy surrounding the indications for performing either a retrograde ureteral stent or percutaneous nephrostomy to manage malignant extrinsic ureteral obstruction (MEUO). We retrospectively analyzed 53 patients who underwent a decompression of MEUO using retrograde ureteral stent. Ureteral stent failure occurred in 18 of 53 patients (34%). Multivariate analysis showed that gastrointestinal cancer as the primary disease, poor preoperative performance status and severe preoperative hydronephrosis were independent predictors of stent failure. Based on the present data, we propose an algorithm for the management of MEUO.     

Obstructed versus dilated nonobstructed kidneys in children with congenital ureteropelvic junction narrowing: role of urinary tubular enzymes

PURPOSE: We evaluated the role of voided urine lysosomal enzyme N-acetyl-beta-D-glucosaminidase and brush border enzymes alkaline phosphatase and gamma-glutamyl transferase in differentiating between children with ureteropelvic junction obstruction in need of pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment. MATERIALS AND METHODS: The study included 35 children with unilateral ureteropelvic junction obstruction treated with pyeloplasty (study group) and 15 children with dilated nonobstructed kidneys who were treated conservatively and followed for 15 months (control group). Voided urine samples were obtained before treatment from both groups, and from the study group at 1, 2, 3, 6, 9 and 12 months postoperatively and the control group at 3, 9 and 15 months of followup. N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were measured in urine samples collected from both groups. RESULTS: In the study group the activities of preoperative urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were significantly higher than in the control group. A cutoff value of 7.8 mU/mg creatinine N-acetyl-beta-D-glucosaminidase yielded a sensitivity of 97.1%, a specificity of 80% and an overall accuracy of 92%. A cutoff value of 34.5 IU/gm creatinine alkaline phosphatase resulted in a sensitivity of 91.4%, a specificity of 100% and an overall accuracy of 94%. A cutoff value of 54 IU/gm creatinine gamma-glutamyl transferase yielded a sensitivity of 62.9%, a specificity of 100% and an overall accuracy of 74%. The combination of urinary N-acetyl-beta-D-glucosaminidase and alkaline phosphatase resulted in a sensitivity of 100%, a specificity of 80% and an overall accuracy of 94%. Compared to preoperative activities, N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase decreased significantly at 12 months after pyeloplasty in the study group. CONCLUSIONS: Voided urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase are accurate markers for differentiating between children with ureteropelvic junction obstruction requiring pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment. Measurement of these enzymes in voided urine could be used as a noninvasive tool for long-term followup of children with ureteropelvic junction obstruction after pyeloplasty and those receiving conservative treatment.     

Reduced number of glomeruli in kidneys with neonatally induced partial ureteropelvic obstruction in pigs

PURPOSE: We quantify the structural components of the nephron in adult pig kidneys with neonatally induced unilateral hydronephrosis in comparison with nonobstructed kidneys. MATERIALS AND METHODS: The study included 11 pigs with unilateral partial ureteropelvic obstruction induced 2 days after birth and 8 sham operated control pigs. Obstructed kidney glomerular filtration rate was significantly reduced at age 4 weeks but did not differ from control kidneys after 24 weeks. At age 24 weeks the kidneys were perfusion fixed, and the number and volume of glomeruli and tubular lengths were measured using stereological methods. RESULTS: Mean obstructed kidney volume did not differ from that of control kidneys. Mean number plus or minus standard deviation of glomeruli in the obstructed kidneys was reduced by 28% compared to that of control kidneys (502 +/- 163 x 103 versus 697 +/- 161 x 103, p = 0.02), whereas no difference in mean glomerular volume was observed. Mean length of the proximal or distal tubules did not differ between obstructed and control kidneys. Mean number or volume of glomeruli in nonobstructed kidneys contralateral to obstructed kidneys did not differ from that of control kidneys. The individual number of glomeruli in the obstructed kidneys was not associated with function of these kidneys. CONCLUSIONS: Neonatally induced unilateral partial ureteropelvic obstruction causes impaired nephrogenesis with a significant reduction in the number of nephrons, which is not reflected in measurements of kidney function in this model. The reduction in the number of glomeruli suggests that congenital unilateral obstruction impairs nephrogenesis.     

膀胱瓣输尿管成形术治疗10例移植肾输尿管梗阻的经验分析

目的:探讨膀胱瓣输尿管成形术(boari flap ureteroplasty,BFU)治疗移植肾输尿管梗阻的效果和经验。方法:回顾性分析我院近5年来应用BFU治疗10例移植肾输尿管梗阻患者的临床资料及随访结果,观察移植肾输尿管是否再次发生梗阻和积水。结果:所有患者移植肾输尿管梗阻均得到完美重建,随访1～5年B超检查未见移植肾梗阻和积水,移植肾功能维持正常。结论:BFU是治疗肾移植术后输尿管长段梗阻的有效方法,且近、远期疗效满意。     

Regional expression of inducible nitric oxide synthase in the kidney in dogs with unilateral ureteral obstruction

PURPOSE: In the early stage of unilateral ureteral obstruction total renal blood flow increases but medullary blood flow decreases, exacerbating medullary tissue hypoxia. We examined the expression of inducible nitric oxide synthase, a product of a hypoxia sensitive gene, in the cortex and medulla in dogs with unilateral ureteral obstruction for 21 hours. MATERIALS AND METHODS: Hemodynamic and clearance experiments were performed after release of ureteral obstruction in 6 dogs with unilateral ureteral obstruction, followed by Western blot analysis of nitric oxide synthase and immunohistochemistry. RESULTS: Ureteral obstruction raised mean ureteral pressure plus or minus standard error to 35.0 +/- 7.2 mm. Hg. In dogs with unilateral ureteral obstruction mean renal blood flow was 116 +/- 10 ml. per minute, lower than the 213 +/- 22 ml. per minute in sham operated dogs (p <0.01). After unilateral ureteral obstruction release the mean glomerular filtration rate was 9.5 +/- 2.1 ml. per minute, lower than the 27.3 +/- 1.8 ml. per minute in the contralateral unobstructed kidney (p <0.01). Western blot analysis showed that mean nitric oxide synthase/beta-actin in the cortex of the obstructed kidney was 0.04 +/- 0.01 densitometry units, lower than 0.11 +/- 0.02 densitometry units in the unobstructed contralateral kidney (p <0.05). In contrast, mean nitric oxide synthase/beta-actin in the medulla of the obstructed kidney was 1.29 +/- 0.33 densitometry units, greater than the 0.34 +/- 0.03 densitometry units in the unobstructed kidney (p <0.05). Immunohistochemistry revealed that the increased expression of nitric oxide synthase protein was localized to the endothelium of the vasa recta. CONCLUSIONS: Unilateral ureteral obstruction enhances nitric oxide synthase expression in the medulla but not in the cortex. This increased expression in the medulla may be the result of increased medullary hypoxia in unilateral ureteral obstruction, possibly contributing to medullary hyperemia after unilateral ureteral obstruction release.     

Percutaneous endopyeloplasty: description of new technique

PURPOSE: We present a novel technique of percutaneous endopyeloplasty, in which the conventional longitudinal endopyelotomy incision is precisely sutured in a horizontal Heineke-Mikulicz fashion through the solitary percutaneous tract, thus, achieving Fenger-plasty type of repair of the ureteropelvic junction. MATERIALS AND METHODS: Percutaneous endopyeloplasty was performed in 9 patients with primary ureteropelvic junction obstruction. Essential steps of our novel technique include retrograde placement of a ureteral catheter over a guide wire into the renal pelvis, establishing conventional percutaneous renal access, creating a conventional longitudinal endopyelotomy incision and performing full-thickness horizontal suturing of the endopyelotomy incision in Heineke-Mikulicz fashion. Suturing was done using the novel 5 mm. Sew Right 5 SR laparoscopic suturing device (LSI Solutions, Rochester, New York) passed through the nephroscope. RESULTS: Percutaneous endopyeloplasty was technically successful in all 9 patients. Mean total operative time was 100.8 minutes (range 62 to 140.), including an endopyeloplasty suturing time of 26.6 minutes (range 14 to 54.). We placed 1 to 4 endopyeloplasty sutures per case. Blood loss was minimal, mean hospital stay was 2.2 days (range 2 to 3) and the ureteral Double-J stent (Medical Engineering Corp., New York, New York) was removed in 2 weeks. At a mean followup of 4 months all operated kidneys showed relief of obstruction, as confirmed by clinical improvement in symptoms and improved renal drainage on excretory urography and diuretic renography. CONCLUSIONS: Percutaneous endopyeloplasty is technically feasible, safe and effective. Potential advantages over conventional endopyelotomy include wider caliber reconstruction of the ureteropelvic junction, full-thickness healing with primary intent, minimal urinary extravasation and shorter stenting duration. To our knowledge the initial clinical experience is presented.     

Laparoscopic pyeloplasty for secondary ureteropelvic junction obstruction

PURPOSE: Laparoscopic pyeloplasty has become a viable option for the treatment of select patients with primary ureteropelvic junction obstruction with success rates similar to those of open surgery. However, little has been written on the application of this technique for secondary ureteropelvic junction obstruction. We report the largest series of secondary ureteropelvic junction obstruction managed by laparoscopic pyeloplasty. MATERIALS AND METHODS: Between March 1994 and March 2001, 36 patients underwent laparoscopic transperitoneal pyeloplasty for secondary ureteropelvic junction obstruction. The patients had undergone an average of 1.3 ureteropelvic junction procedures (range 1 to 4) prior to presentation, including cutting balloon retrograde endopyelotomy in 28, antegrade endoscopic endopyelotomy in 7, retrograde endoscopic endopyelotomy in 4, retrograde balloon dilation in 4 and open pyeloplasty in 3. A preoperative diagnosis of recurrent obstruction was confirmed by renal scan in 31 cases, retrograde pyelography in 2 and computerized tomography in 3. Of the 31 patients who underwent spiral computerized tomography angiogram 87% had crossing vessels. Laparoscopic repair comprised dismembered pyeloplasty in 31 cases, Fengerplasty in 3 and flap repair in 2. Postoperative renal scan or excretory urography objective followup was available for all patients at a mean of 10 months (range 3 to 40). Postoperative subjective patient well-being was assessed using an analog pain scale at a mean followup of 21.8 months (range 3 to 85). RESULTS: Average operative time was 6.2 hours (range 2.7 to 10). Average hospital stay was 2.9 days (range 1 to 7). One intraoperative complication occurred, that is bleeding necessitating conversion to an open procedure. Postoperative complications occurred in 8 cases, including anastomotic leakage in 4, and urinary tract infection, pneumonia, atelectasis, fever, bilateral upper extremity weakness and stone formation 2 months postoperatively in 1 each. On excretory urography, furosemide renal scan or the Whitaker test 32 of 36 patients (89%) had a widely patent ureteropelvic junction. Two patients (5.5%) had equivocal radiographic studies but were asymptomatic. In 2 patients the ureteropelvic junction was obstructed by renal scan. One patient had an indwelling stent for renal function deterioration and 1 was asymptomatic. Hence, 34 of the 36 patients (94%) had a reasonable objective response. Overall a 50% or greater decrease in pain was seen in 32 of 36 patients (89%). In the 4 patients with a less than 50% decrease in pain objective renal scans showed an open ureteropelvic junction. As such, the overall success rate of a greater than 50% decrease in pain, a patent ureteropelvic junction and stable or improved function of the affected renal unit was 83% (30 of 36 patients). CONCLUSIONS: For secondary ureteropelvic junction obstruction, laparoscopic pyeloplasty can be performed safely with a success rate comparable to that of standard open pyeloplasty. The patient benefits of laparoscopic ureteropelvic junction repair of secondary ureteropelvic junction obstruction are similar to the benefits of laparoscopic repair of primary ureteropelvic junction obstruction.     

The 3-port laparoscopic pyeloplasty

PURPOSE: We describe our technique of a 3 port approach for transperitoneal laparoscopic pyeloplasty and its evolution. MATERIALS AND METHODS: Between August 1999 and February 2003, 56 patients underwent laparoscopic transperitoneal pyeloplasty. The operative procedure, including patient positioning, surgical technique and postoperative care, is described in detail. For analysis patients were divided into 2 groups, namely an initial 4 port approach and a later 3 port approach. The number of additional ports placed and the reasons why were determined. RESULTS: In the initial 14 patients a 4 port plan was used and 1 (7.2%) required a fifth port. In the subsequent 42 patients surgery was initiated with a 3 port plan and 8 (19%) required 1 additional port, while 2 (4.8%) required 2 additional ports. Of the extra ports used 50% were necessary for liver retraction in procedures on the right side. In patients with greater than 10 renal calculi a retrieval pouch was used, necessitating an additional port. A planned 3 port approach was feasible in 32 of the 42 cases (76.2%) and even initially a 4 port approach was sufficient in 13 of 14 (92.9%). CONCLUSIONS: We believe that our 3 port, transabdominal laparoscopic pyeloplasty technique is an efficient one with the least number of incisions and morbidity to the patient. It has proved to be feasible in more than 75% of our cases. Additional ports can easily be added but usually they are not required.     

DISMEMBERED V-FLAP PYELOPLASTY

PURPOSE: We present a modified technique of pyeloplasty that seems ideally suited for reoperative as well as primary repair of ureteropelvic junction obstruction due to high ureteral insertion. MATERIALS AND METHODS: This repair combines the dismembered technique with creation of a V-flap of renal pelvis by dividing and incising through the ureteropelvic junction superolateral onto the pelvis to a height above the most dependent portion of the pelvis just exceeding the length of ureteral spatulation. The V-flap is completed by an inferolateral incision directed toward the lateral aspect of the pelvis at its most dependent portion. The tip of the V-flap is then flipped down and approximated to the apex of the posterior ureteral spatulation. Of the 12 cases managed by this procedure 2 were reoperative and 10 involved select primary repair with high ureteral insertion at the ureteropelvic junction. Patient age was 3 months to 17 years (median 11 months). Two procedures were performed via a dorsal lumbar incision in the oldest patients and 10 were done via the standard anterior extraperitoneal approach. Radiological evaluation, including mercaptoacetyltriglycine renal scan and/or excretory urography, was performed in all patients preoperatively and postoperatively. RESULTS: In all patients postoperative mercaptoacetyltriglycine renal scan and/or excretory urography at 3 months and 1 year showed excellent drainage after dismembered V-flap pyeloplasty. CONCLUSIONS: Dismembered V-flap pyeloplasty has proved to be successful with a number of advantages over the Anderson-Hynes dismembered technique in select patients. These advantages include the avoidance of tissue tension that make mobilization of the kidney and ureter unnecessary, aggressive ureteral spatulation, creation of a dependent, funneled configuration and automatic tapering of a redundant pelvis in the routine course of closure without excision of tissue. This technique also has the advantage of being simpler than other flap repairs and it combines the physiological virtues of dismembered repair with the anatomical advantages of flap pyeloplasty.     

Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome

PURPOSE: Horseshoe kidney is the most common renal fusion anomaly. We determined the treatment and outcome of vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney. MATERIALS AND METHODS: We reviewed the medical and radiological records of 52 consecutive children, including 32 boys and 20 girls, in whom horseshoe kidney was diagnosed at 2 children's hospitals during 1990 to 1999. Patient age at diagnosis was 1 day to 12 years (mean 3.9 years). In 2 children with horseshoe kidney neuropathic bladder was secondary to spina bifida and they were excluded from study. The diagnosis was made in all cases by abdominal ultrasound and confirmed by excretory urography or (99m)technetium-dimercaptosuccinic acid scan. Voiding cystourethrography was performed in 40 cases (80%). Patients were followed for 2 to 11 years (mean 4.2). RESULTS: Associated urological anomalies were identified in 26 patients (52%) with horseshoe kidney, including primary vesicoureteral reflux in 13, ureteropelvic junction obstruction in 12 and ectopic ureter in 1. Surgical intervention to correct the anomalies in 15 of the 26 children (58%) involved pyeloplasty in 8, ureteral reimplantation in 2, endoscopic treatment for vesicoureteral reflux in 2, ureterolithotomy in 1, upper pole heminephrectomy in 1 and valve fulguration in 1. No significant complications were observed in surgically treated patients. CONCLUSIONS: More than half of the patients with a clinically symptomatic horseshoe kidney have vesicoureteral reflux or ureteropelvic junction obstruction. Many patients with horseshoe kidney require surgical intervention for associated urological anomalies with good results.     

MISSED ANTERIOR CROSSING VESSELS DURING OPEN RETROPERITONEAL PYELOPLASTY: LAPAROSCOPIC TRANSPERITONEAL DISCOVERY AND REPAIR

PURPOSE: Extrinsic ureteropelvic junction obstruction due to anterior crossing segmental renal vessels is present in more than 50% of patients in adulthood. In this situation the ureter must usually be dismembered and transposed anterior to the crossing vascular structures, where it is anastomosed to the renal pelvis. Via the open retroperitoneal approach there may be a limited view of the anterior surface of the ureteropelvic junction and, hence, anterior crossing vessels may possibly be missed. We describe 2 patients with ureteropelvic junction obstruction in whom anterior vessels were missed during open retroperitoneal repair. Laparoscopic transperitoneal secondary pyeloplasty with posterior displacement of the crossing renal vessel was performed in each case. MATERIALS AND METHODS: Two patients presented with symptomatic congenital ureteropelvic junction obstruction after failed endopyelotomy in 1 and failed open retroperitoneal procedures in both. Preoperatively spiral computerized tomography angiography with a ureteropelvic junction protocol revealed crossing vessels in the 2 cases. This finding was confirmed at transperitoneal laparoscopic pyeloplasty. The ureter and renal pelvis were transposed anterior to the crossing vessels and 2 rows of running sutures were placed to complete the anastomosis. RESULTS: The 2 laparoscopic procedures were completed successfully. The anterior crossing vessels were preserved in each case. Currently the patients are asymptomatic and furosemide washout renal scan was normal. CONCLUSIONS: Spiral CT angiography reliably delineates the renal vascular anatomy in patients with ureteropelvic junction obstruction. This study may be valuable before planned open retroperitoneal ureteropelvic junction obstruction repair. Laparoscopic pyeloplasty may successfully manage anterior crossing vessels associated with secondary ureteropelvic junction obstruction.     

Prospective, randomized comparison of ureteroscopic endopyelotomy using holmium:YAG laser and balloon catheter

PURPOSE: We compared the safety and efficacy of the 2 retrograde endopyelotomy techniques. MATERIALS AND METHODS: A prospective study was done from January 2001 to October 2003. Preoperative radiological evaluation included excretory urography, multiphasic helical computerized tomography and diuretic renography. Exclusion criteria were marked hydronephrosis, ipsilateral renal function less than 25% and renal stones or a significant crossing vessel at the ureteropelvic junction. Eligible patients were randomized to ureteroscopic laser endopyelotomy and retrograde Acucise endopyelotomy (20 per group). UPJ obstruction was primary in 14 patients and secondary in 26. The ureteropelvic junction was incised in the lateral direction and an endopyelotomy Double-J stent (Medical Engineering Corp., New York, New York) was left for 6 weeks. Subjective and objective outcomes were evaluated 3 and 6 months after stent removal, and every 6 months thereafter. RESULTS: Mean operative time +/- SD was comparable in the laser and Acucise groups (64.7 +/- 22.4 and 58.7 +/- 20.2, respectively). The overall complication rate in the Acucise group was more than in the laser group (25% vs 10%). At a mean followup of 29.9 +/- 10.8 months (range 6 to 48) the laser group showed a higher success rate than the Acucise group (85% vs 65%) but the difference in the complication and success rates was not statistically significant. CONCLUSIONS: Despite the advanced endourological skills required for ureteroscopic laser endopyelotomy its safety and efficacy seem to be better than those of Acucise endopyelotomy. However, a larger number of patients is needed to confirm these findings.