The dilemma of the crossing vessel at the ureteropelvic junction: precise anatomic study

Our experience of operated pediatric ureteropelvic junction obstruction patients

AIMS

Ureteropelvic junction obstruction (UPJO) may originate from extrinsic or intrinsic causes in children. The aim of this study is to present preoperative and postoperative data of our patients operated for UPJO.

METHODS

A total of 64 patients who underwent open pyeloplasty were investigated retrospectively. They were evaluated in terms of demographically, clinics, hydronephrosis, differential renal functions (DRFs), half-time tracer clearance (½TC), and histopathologic results. Patients' numerical results were stated as mean ± standard deviation (SD).

RESULTS

Male gender was more prevalent (n = 47, 73.4%) and mean age at surgery was 46.87 months. UPJO was located at the left side in 56.3% (n = 36), and at the right side in 39.1% (n = 25) of patients. It was bilateral in 4.7% (n = 3). Hydronephrosis was found antenatally in 68.8% (n = 44) of patients. The mean preoperative DRF was 49.7% (21-78%) and mean postoperative DRF was 49.2% (20-56%). Mean renal scintigraphic t1/2 was >20 min for all patients. The mean AP diameter was 21.58 mm (10-62 mm). Muscular hypertrophy was the most common pathological finding, mean length of excised segment was 10.26 mm (3-40 mm). Crossing vessel (CV) was detected in 17.18% (n = 11). The CV was statistically associated with increased age of operation, left side, and female gender. Statistically significant hydronephrosis was found in non-CV patients. Re-operation was required in seven patients (7.8%).

CONCLUSIONS

Intrinsic pathologies are more seen in the etiology of UPJO patients with antenatal diagnosis and this group needs operation at an earlier age. However, CV is found more commonly in patients who are diagnosed and operated at older ages.

Minimally Invasive Treatment of Pediatric Extrinsic Ureteropelvic Junction Obstruction by Crossing Polar Vessels: Is Vascular Hitching a Definitive Solution? Report of a Multicenter Survey

BACKGROUND

This article aimed to evaluate the outcome of laparoscopic vascular hitch (VH) as an effective alternative to dismembered pyeloplasty in the treatment of children with extrinsic ureteropelvic junction obstruction (UPJO) by crossing vessels (CVs), by reporting the experience of three Italian centers of Pediatric Surgery.

METHODS

From 2006 to 2014, 54 children (18 girls and 36 boys, average age 10.7 years) affected by suspected extrinsic UPJO by CV were treated in three different institutions: 51 patients underwent laparoscopic VH, while 3 patients, in which a coexisting intrinsic etiology of UPJO was doubtful, underwent laparoscopic dismembered pyeloplasty. Preoperative diagnostic workup included: ultrasound (US)/Doppler scan, mercaptoacetyltriglycine (MAG3)-renal scan, and functional-magnetic-resonance-urography (fMRU). Symptoms at presentation were recurrent abdominal/flank pain and hematuria. All patients presented intermittent hydronephrosis (range 18-100 mm) on US and an obstructive pattern on MAG3 renogram.

RESULTS

Average operative time was 108 minutes, and average hospital stay was 1.8 days. As for complications, we reported a small abdominal wall hematoma and a high UPJ distortion without obstruction in 2 patients, not requiring reintervention (grade I Clavien-Dindo). At follow-up (range 12-96 months), all patients reported resolution of symptoms, decrease in the hydronephrosis grade, and improved drainage on MAG3 renogram.

CONCLUSIONS

Our results demonstrated the safety and efficacy of laparoscopic VH for treatment of extrinsic UPJO by CV, registering excellent outcomes in a very selected patient population. The careful selection of patients through intraoperative assessment of anatomical and functional aspects is a crucial step to confirm indications for VH and maintain a high success rate with the procedure. We believe that any concerns regarding the coexistence of intrinsic stenosis should certainly lead to opening the collecting system and to performing a classic dismembered pyeloplasty.

Laparoscopic transposition of lower pole crossing vessels (vascular hitch) in children with pelviureteric junction obstruction

BACKGROUND

Congenital hydronephrosis due to intrinsic or extrinsic uretero-pelvic-junction (UPJ) obstruction (UPJO) is a common problem in childhood UPJO may be caused by intrinsic disorganization or by extrinsic compression from crossing vessels (CV); extrinsic causes usually present symptomatically in older children. This report the large Italian experience in the treatment of children with extrinsic-UPJO by CV.

METHODS

We analyzed the data of 51 children (17 girls and 34 boys, median age 10, 7 years) affected by extrinsic-UPJO were treated in three Italian institutions with laparoscopic transposition of CV (Hellström Vascular Hitch modified by Chapman).The intraoperative diuretic-test was performed in all patients before and after the vessels transpositions confirming the extrinsic-UPJO. We included in the study only patients with suspicion of vascular extrinsic obstruction of the UPJ. Symptoms at presentation were recurrent abdominal/flank pain and haematuria. All patients presented intermittent ultrasound (US) detection of hydronephrosis (range, 18-100 mm). Preoperative diagnostic studies included: US/doppler scan, MAG3-renogram, functional-magnetic-resonance-urography (fMRU).

RESULTS

Median operative time was 108 minutes; median hospital stay: 3, 4 days. Unique complications: a small abdominal wall hematoma and higher junction-translocation without obstruction. During follow-up (range, 12-96 months) all patients reported resolution of their symptoms, a decrease in the hydronephrosis grade and improved drainage on diuretic renogram.

CONCLUSIONS

We believe that Vascular Hitch is less technically demanding than laparoscopic pyeloplasty, resulting in a lower complication rate and a significantly reduced hospitalization. The results of our study allow us to conclude that laparoscopic VH may be a safe, feasible, and attractive alternative to treat obstructed hydronephrosis due to CV presenting a useful alternative to AHDP in the management of symptomatic children where CV are deemed the sole aetiology. We recommend careful patient selection based on preoperative clinical and radiologic findings that are diagnostic of extrinsic-UPJO, combined with intraoperative-DT to confirm the appropriate selection of corrective procedure.

Renal Vein Injury During Percutaneous Nephrolithotomy Procedure

Background: Percutaneous nephrostolithotomy is an important approach for removing kidney stones. Puncturing and dilatation are two mandatory steps in percutaneous nephrolithotomy (PCNL). Uncommonly, during dilatation, the dilators can cause direct injury to the main renal vein or to their tributaries.

Case Presentation: A 75-year-old female underwent PCNL for partial staghorn stone in the left kidney. During puncturing and dilatation, renal vein tributary was injured, and the nephroscope entered the renal vein and inferior vena cava, which was clearly recognized. Injection of contrast material through the nephroscope confirms the false pathway to the great veins (renal vein and inferior vena cava). Bleeding was controlled intraoperatively by applying Amplatz sheath over the abnormal tract, the procedure was continued and stones were removed. At the end of the procedure, a Foley catheter was used as a nephrostomy tube and its balloon was inflated inside the renal pelvis and pulled back with light pressure to the lower calix, which was the site of injury to the renal vein tributaries, then the nephrostomy tube was closed; by this we effectively controlled the bleeding. The patient remained hemodynamically stable; antegrade pyelography was done on the second postoperative day, there was distally patent ureter with no extravasation, neither contrast leak to renal vein, and was discharged home at third postoperative day. After 2 weeks, the nephrostomy tube was gradually removed in the operative room, without bleeding, on the next day, Double-J stent was removed.

Conclusion: Direct injury and false tract to the renal vein tributaries during PCNL can result in massive hemorrhage, and can be treated conservatively in hemodynamically stable patients, using a nephrostomy catheter as a tamponade.

Intraoperative inspection of the ureteropelvic junction during pyeloplasty is not sufficient to distinguish between extrinsic and intrinsic causes of obstruction: Correlation with histological analysis

INTRODUCTION

Based on current knowledge, it is possible to have an initial diagnosis of intrinsic or extrinsic ureteropelvic junction obstruction (UPJO) based solely on clinical and imaging findings. However, it may not be possible to strictly discriminate an intrinsic case with an additional extrinsic component from a primarily intrinsic stenosis because of lower pole aberrant vessels. These two disorders may coexist or trigger each other. Herein, we aimed to compare the histological changes observed in intrinsic and extrinsic types of UPJO. Our hypothesis is that inspecting the UPJ during pyeloplasty may not be a sufficient way to delineate the underlying cause of obstruction in every individual.

MATERIAL AND METHODS

We retrospectively reviewed the data of 56 patients who had dismembered pyeloplasty. The intrinsic and extrinsic groups consisted of 38 and 18 patients, respectively. Masson's trichrome stain, CD117, and connexin 43 (Cx43) antibody were used in histopathology and immunochemistry. Statistical calculations were done with chi-square and Mann-Whitney U tests.

DISCUSSION

Connexin 43 staining pattern, CD117 positive cell count, and the extent of fibrosis did not differ significantly between extrinsic and intrinsic cases. However, the difference with regard to the degree of muscular hypertrophy was close to statistical significance. The exact pathophysiological mechanism underlying UPJO has yet to be elucidated. A study directly comparing both groups histologically is indeed rare. Our study showed that there are no significant differences between the intrinsic and extrinsic groups in terms of the pacemaker activity, gap junctional communication, and extent of fibrosis. Muscular hypertrophy, which was marginally higher in our extrinsic group, may persist despite successful relocation of the obstructing vessel. The main drawbacks of our study are; the absence of a control group and the retrospective study design with its inherent selection biases.

CONCLUSIONS

Immunohistochemical profiles of intrinsic and extrinsic UPJOs resemble each other. Intraoperative inspection of the UPJ may not be enough for accurate discrimination for a surgical procedure that can correct only the extrinsic cause.

Metachronous renal vein and artery injure after percutaneous nephrostolithotomy

Background

Percutaneous nephrostolithotomy is important approach for kidney stones removal. A percutaneous nephrostomy drainage tube placement is an effective method to stop venous bleeding. Occasionally, the catheter can pierce into the renal parenchyma, and migrate into the renal vein even to the vena cava.

Case presentation

A 66-year-old woman underwent a percutaneous nephrostolithotomy for kidney staghorn stone complicating severe bleeding. A computed tomography angiography showed the percutaneous nephrostomy drainage tube inside the renal vein. The percutaneous nephrostomy drainage tube was withdrawn 3 cm back to the renal parenchyma/sinus/pelvis in stages with the surgical team on standby. Seven days later, the patient developed severe hematuria. Computed tomography angiography demonstrated the pseudoaneurysm located near the percutaneous nephrostomy drainage tube. Pseudoaneurysm is embolized successfully.

Conclusion

Our case shows intravenous misplacement of the nephrostomy tube and subsequent pseudoaneurysm after percutaneous nephrostolithotomy. To our knowledge, this seems to be the first documentation of major bleeding from the injury to both renal vein and artery. The percutaneous nephrostomy drainage tube can be withdrawn back to the renal parenchyma/sinus/pelvis in stages with the surgical team on standby, and the withdrawn distance may vary according to patient and catheter position.

Nature of crossing vessels in patients with radiographically normal ureteropelvic junctions: prevalence and anatomic characteristics

OBJECTIVE

To evaluate the prevalence and characteristics of crossing vessels in asymptomatic patients with a radiographically normal ureteropelvic junction.

MATERIALS AND METHODS

We retrospectively reviewed the computed tomography angiography images of 601 patients who were evaluated for possible living organ donation at the University of Minnesota from 2005 to 2008. One patient had asymptomatic hydronephrosis and was excluded from the analysis. The prevalence and characteristics of crossing vessels at the ureteropelvic junction were determined, including vessel location, origin, size, distance from the ureteropelvic junction, and vessel type (artery or vein).

RESULTS

The prevalence of crossing vessels at the radiographically normal ureteropelvic junction was 22.7%. A total of 163 crossing vessels were present in 136 patients; 60.1% were left-sided and 39.9% were right-sided. Arteries accounted for 81.0% of the crossing vessels and veins for 19.0%. Accessory lower pole renal vessels originating from the great vessels constituted 59.5% of the crossing vessels. The location of the crossing vessel relative to the ureteropelvic junction varied and included anterior (25.8%), anterolateral (36.8%), medial (14.6%), anteromedial (2.5%), lateral (12.9%), and posterior (7.4%). The mean diameter and mean distance of the crossing vessel from the ureteropelvic junction was 3.3 mm and 1.8 mm, respectively.

CONCLUSION

The prevalence of crossing vessels in asymptomatic, healthy patients with a radiographically normal ureteropelvic junction was 22.7%, lower than that seen in association with ureteropelvic junction obstruction. The location of the crossing vessels varied about the ureteropelvic junction, and no location was consistently free of traversing vessels.

[A case report of ureteropelvic junction obstruction and multiple renal stones associated with nutcracker syndrome]

A 20 year-old man presented to emergency room with severe left-sided flank pain. Urinalysis showed hematuria and he was referred to the urology department. KUB, DIP and retrograde pyelography (RP) revealed multiple renal stones, left hydronephrosis (grade 2) and ureteropelvic junction obstruction (UPJO). Abdominal CT revealed shortened nutcracker distance and renal angiography showed left renal vein hypertension. From these findings, diagnosis of nutcracker syndrome was made. Transposition of the left renal vein, dismembered pyeloplasty and left pyelolithotomy were performed simultaneously. 2 months after the procedure, his symptom and hematuria disappeared. 3 months after the procedure, DIP revealed improvement of hydronephrosis (grade 1) and CT showed elongation of nutcracker distance. In 12 months follow-up, there was no recurrence of symptom and hydonephrosis. To the best our knowledge, there has been no report of UPJO associated with nutcracker syndrome and the simultaneous treatment for the both diseases.

Accessory or additional renal arteries show no relevant effects on the width of the upper urinary tract: a 64-slice multidetector CT study in 1072 patients with 2132 kidneys

OBJECTIVE

The aim of this study was to find out on an unselected patient group whether crossing vessels have an influence on the width of the renal pelvis and what independent predictors of these target variables exist.

METHODS

In this cross-sectional study, 1072 patients with arterially contrasted CT scans were included. The 2132 kidneys were supplied by 2736 arteries.

RESULTS

On the right side, there were 293 additional and accessory arteries in 286 patients, and on the left side there were 304 in 271 patients. 154 renal pelves were more than 15 mm wide. The greatest independent factor for hydronephrosis on one side was hydronephrosis on the contralateral side (p<0.0001 each). Independent predictors for the width of the renal pelvis on the right side were the width of the renal pelvis on the left, female gender, increasing age and height; for the left side, predictors were the width of the renal pelvis on the right, concrements, parapelvic cysts and great rotation of the upper pole of the kidney to dorsal. Crossing vessels had no influence on the development of hydronephrosis. Only anterior crossing vessels on the right side are associated with widening of the renal pelvis by 1 mm, without making it possible to identify the vessel as an independent factor in multivariate regression models.

CONCLUSION

The width of the renal pelvis on the contralateral side is the strongest independent predictor for hydronephrosis and the width of the renal pelvis. There is no link between crossing vessels and the width of the renal pelvis.

Pathologic findings in patients with ureteropelvic junction obstruction and crossing vessels

OBJECTIVES

To define the role of crossing vessels in the pathophysiology of ureteropelvic junction (UPJ) obstruction, we analyzed the relationship between the presence of crossing vessels and UPJ pathologic findings in patients undergoing laparoscopic pyeloplasty. The significance of crossing renal vessels in patients with UPJ obstruction is unclear.

METHODS

We performed a retrospective analysis of 155 consecutive patients undergoing laparoscopic pyeloplasty. Pathologic specimens from the UPJ were evaluated in 95 patients. The presence or absence of crossing vessels was documented intraoperatively. The histopathologic findings allowed for categorization into 5 groups: group 1, normal ureteral tissue; group 2, chronic inflammation; group 3, smooth muscle hypertrophy, group 4, fibrosis; and group 5, smooth muscle atrophy. The pathologic findings between patients with and without crossing vessels were compared.

RESULTS

Overall, crossing vessels were identified in 98 patients (63.2%). Of the 95 cases with specimens retrieved for histologic analysis, 65 had crossing vessels and 30 did not. The most common UPJ histologic finding in patients with crossing vessels was no intrinsic abnormality (43%). In contrast, this was seen in only 10% of patients without a crossing vessel. In the group without crossing vessels, chronic inflammation (40%) was the predominant histologic findings. Patients with a crossing vessel were less likely to have intrinsic histologic pathologic findings (P < .0003).

CONCLUSIONS

Patients with crossing vessels and UPJ obstruction had no histologic abnormalities identified in 43% of cases. This finding implicates crossing vessels in the pathogenesis of select cases of UPJ obstruction and direct mechanical compression as the etiology of obstruction in these individuals.

Minimally invasive treatment of ureteropelvic junction obstruction: a critical analysis of results

OBJECTIVES

To analyse the indications and long-term results of endoscopic and minimal access approaches for the treatment of ureteropelvic junction (UPJ) obstruction and to compare them to open surgery.

METHODS

A review of the literature from 1950 to January 2007 was conducted using the Ovid Medline database.

RESULTS

A lack of standardisation of techniques used to diagnose UPJ obstruction and to follow up treated patients introduces a degree of inaccuracy in interpreting the success rates of the various modalities of treatment. However, there is no indication that any one of these techniques is affected by this to a greater or lesser extent than another. Open pyeloplasty achieves very good (90-100% success) results, endopyelotomy and balloon disruption of the UPJ fail to match these results by 15-20%, and minimal access pyeloplasty produces results that are at least as good as those of open surgery but with the advantages of a minimal access approach.

CONCLUSIONS

Minimal access pyeloplasty is likely to gradually replace endopyelotomy and balloon disruption of the UPJ for the treatment of UPJ obstruction. The much higher cost of robotic pyeloplasty and greater availability of laparoscopic expertise in teaching centres are likely to limit the dissemination of robotic pyeloplasty.

Long-Term Outcome of Endopyelotomy for The Treatment of Ureteropelvic Junction Obstruction: How Long Should Patients Be Followed Up?

PURPOSE

To evaluate the long-term success rate of endopyelotomy for the treatment of ureteropelvic junction (UPJ) obstruction.

PATIENTS AND METHODS

Between January 1995 and December 2003, 85 endopyelotomies (10 percutaneous, 75 retrograde) were performed in 77 patients with a mean age of 35.2 +/- 13.9 years. The mean number of procedures per patient was 1.14, with 69 patients undergoing a single procedure. Endopyelotomies were performed using either a cold knife (N = 26), Ho:YAG laser (N = 47), or hook electrode (N = 12). Treatment success was defined as symptomatic relief with radiographic resolution or stabilization of renal function, as judged by an excretory urogram or diuretic renogram. Kaplan-Meier analysis was used to determine the long-term probability of success.

RESULTS

With a median follow-up of 37.3 months (range 3-98 months), the overall success rate was 67.5%, and the median time to failure was 7.7 months (range 1-50 months). Kaplan-Meier estimates of success were 87.8% at 6 months, 76.9% at 12 months, 72.2% at 18 months, 68.7% at 24 months, 64.8% at 36 months, and 61.6% at 60 months. The success rate was not significantly affected by the etiology, surgical approach, or incisional method. Similarly, the degree of preoperative hydronephrosis or renal function did not affect the success rate.

CONCLUSIONS

The success rate of endopyelotomy decreases as the follow-up increases. Although most failures were detected within 1 year of the procedure, it appears that follow-up of at least 36 months is required for patients who have undergone endopyelotomy for UPJ obstruction.

Retrograde endopyelotomy: a comparative study of hot-wire balloon and ureteroscopic laser

PURPOSE

This study compared the immediate and long-term results and complications of hot-wire balloon endopyelotomy and ureteroscopic holmium laser endopyelotomy.

PATIENTS AND METHODS

Between March 1994 and January 2002, 64 patients with a primary (N = 52) or secondary (N = 12) ureteropelvic junction obstruction underwent retrograde endopyelotomy using either a fluoroscopically guided hot-wire balloon incision (N = 27) or a ureteroscopically guided, direct-vision holmium laser incision (N = 37). This study group included 46 women and 18 men aged 13 to 79 years (mean 38.9 years). The indications and contraindications to a retrograde approach were identical in each group and included documented functionally significant evidence of obstruction, no upper-tract stones, obstruction <2 cm, and no radiographic evidence of entanglement of crossing vessels at the ureteropelvic junction. Immediate and long-term outcomes were obtained from a prospective registry, with success defined as resolution of symptoms and radiographic relief of obstruction as determined by follow-up with intravenous urography, diuretic renography, or both. Follow-up ranged from 39 to 133 months (mean 75.6 months).

RESULTS

Length of hospital stay, indwelling stent duration, and long-term success rates (77.8% v 74.2% in the hot-wire balloon and holmium-laser group, respectively) were equivalent. However, two patients in the hot-wire balloon group developed bleeding necessitating transfusion and selective embolization of lower-pole vessels. No patient in the ureteroscopic group suffered a major complication.

CONCLUSIONS

These two alternatives for retrograde endopyelotomy provide comparable success rates for similarly selected patients. However, because significant hemorrhagic complications developed with greater frequency in those treated with the hot-wire balloon, our preference is for a ureteroscopic approach, as it allows direct visual control of the incision and thus, a lower risk of significant bleeding.

Reconstructive surgery of the upper urinary tract

This paper reviews the major publications over the past year regarding upper urinary tract reconstruction. Controversies in the diagnosis of ureteropelvic junction obstruction and in the surgical repair of the obstructed upper urinary tract are discussed. Special emphasis is placed on issues surrounding minimally invasive techniques.

The incidence of crossing vessels in patients with normal ureteropelvic junction examined with endoluminal ultrasound

PURPOSE

We estimated the incidence of a crossing vessel at the normal ureteropelvic junction (UPJ) in patients undergoing ureteroscopy and endoluminal ultrasonography for indications other than UPJ obstruction.

MATERIALS AND METHODS

Endoluminal ultrasonography was performed in 141 patients undergoing upper tract endoscopy for various indications excluding UPJ obstruction. A detailed description of the anatomy of the UPJ as well as the location and size of crossing vessels was included in the operative note. Charts were reviewed to determine the precise anatomy of the UPJ.

RESULTS

The overall incidence of crossing vessels at the unobstructed UPJ was 19.2%. Endoluminal ultrasonography demonstrated a crossing vessel in 13.2% of patients with ureteral narrowing or stricture, 31.3% of those with tumors or filling defects, 10.5% of those with submucosal calculi and 16.7% of patients with ureteral diverticula. In cases where the position of a crossing vessel was ascertained, 41% were anterior to the ureter, 28% anterolateral, 24% anteromedial and 7% posterior. There was a statistically significant difference in the frequency of vessels at the UPJ in patients with and without obstruction examined with endoluminal ultrasound (p <0.0001).

CONCLUSIONS

A crossing vessel at the UPJ is seen with endoluminal ultrasound in 19.2% of patients with a normal UPJ. This incidence is lower than that seen in patients with obstructed UPJ. Many of these vessels are related to the lateral surface of the UPJ and there was no area that was always free of vessels.

Management of renal-vein perforation during a challenging percutaneous nephrolithotomy

A 54-year-old man with complex urinary anatomy as the result of previous surgery sustained a renal-vein injury during percutaneous nephrolithotomy for a staghorn calculus with a blood loss of 1.5 L. He was managed with antibiotics, bed rest, heparin, and a 28F nephrostomy catheter, which was withdrawn gradually as the tract sealed. This case highlights the importance of early diagnosis of this complication and the possibility of conservative management.

Adult Ureteropelvic Junction Obstruction: Insights with Three-dimensional Multi–Detector Row CT

Ureteropelvic junction obstruction (UPJO) is a benign, congenital condition that remains an enigma in terms of both diagnosis and therapy. On the basis of a series of cases that were referred to the authors in their clinical practice, they found that the unprecedented quality and novel perspectives of multi-detector row computed tomography (CT) with two- and three-dimensional postprocessing allow a comprehensive, single-study assessment of the ureterovascular relationships in UPJO. This topic is important because the causative role of crossing vessels may be questioned on the basis of such studies, and the therapeutic approach may be altered by using precise anatomic images customized to the pathologic features of the individual patient. Although CT images can provide only circumstantial or supportive evidence of the pathophysiology of UPJO, they greatly facilitate therapeutic intervention when it is clinically indicated and may eliminate the need for it in select cases. Careful attention to the postprocessing of CT images may show that the crossing vasculature has no direct relationship to the transition point of the UPJO in many cases.

Endopyelotomy in Childhood: Our Experience with 37 Patients

PURPOSE

To evaluate our experience and results with endopyelotomy in the pediatric population.

PATIENTS AND METHODS

Between 1990 and 2002, we performed percutaneous antegrade endopyelotomy under general anesthesia in 37 children because of ureteropelvic junction (UPJ) stricture. The youngest patient was 4.5 years and the oldest 17 years at the time of the procedure (mean age 11.5 years). One patient had bilateral stenosis; the two sides were operated on separately. After insertion of a 4F ureteral catheter and filling the collecting system with colored contrast material, a middle calix was punctured under fluoroscopic control. The tunnel was dilated to 26F by telescopic metal dilators. After insertion of a 0.035-inch gidewire through the UPJ, all its layers were cut by a cold knife in the dorsolateral direction so that the periureteral fatty tissue could be seen. Finally, the ureteral wound was stented by a 6F to 12F transrenal drain or a double-J catheter, which was removed after 6 weeks.

RESULTS

Among the 37 patients, the procedure had to be repeated in 1 because the transrenal drain stenting the UPJ slid back to the renal pelvis. We had to perform open pyeloplasty or nephrectomy in two patients because of bleeding or failed procedure. The average postoperative hospital stay was 6 days. Comparison of the preoperative intravenous urograms with studies performed 1 year after endopyelotomy showed an overall success rate of 89%. All patients are without complaints at the moment.

CONCLUSIONS

In experienced hands, endopyelotomy is a safe and effective method for the treatment of UPJ stricture, not only in the adult, but also in the pediatric, population.

Color Doppler Ultrasonography in the Diagnosis of Vascular Abnormalities Associated with Ureteropelvic Junction Obstruction

PURPOSE

To determine if color Doppler ultrasonography is able to identify vascular abnormalities linked to ureteropelvic junction (UPJ) obstruction.

PATIENTS AND METHODS

We used color Doppler scanning in 21 patients to determine whether there were aberrant vessels.

RESULTS

The study detected 11 aberrant vessels, resulting in 10 true positives and 9 true negatives. Thus, the overall diagnostic accuracy was 90.4%.

CONCLUSION

Color Doppler ultrasonography is reliable in the preoperative diagnosis of aberrant vessels associated with UPJ obstruction.

Single-center comparison of laparoscopic pyeloplasty, Acucise endopyelotomy, and open pyeloplasty

PURPOSE

To compare Acucise endopyelotomy (Applied Medical, Irvine, California), laparoscopic pyeloplasty, and open pyeloplasty in the treatment of ureteropelvic junction (UPJ) obstruction.

PATIENTS AND METHODS

A retrospective review of all adult patients undergoing surgical correction of UPJ obstruction between December 1999 and August 2001 at Vanderbilt University Medical Center was performed. Patients undergoing UPJ correction with Acucise endopyelotomy (N = 9), laparoscopic pyeloplasty (N = 16), and open pyeloplasty (N = 7) were compared in regard to demographic information, operative data, recovery parameters, cost data, and outcome (as determined by diuretic renography, the Whitaker test, or both).

RESULTS

Success rates of 56%, 94%, and 86% were obtained for Acucise endopyelotomy, laparoscopic pyeloplasty, and open pyeloplasty, respectively. There were no differences between the Acucise endopyelotomy and laparoscopic pyeloplasty groups in age, American Society of Anesthesiology (ASA) score, length of follow-up, estimated blood loss (EBL), hospital stay, total hospital cost, or analgesic requirement. The Acucise patients demonstrated shorter operating times (1.7 v 3.3 hours; P < 0.001) and time to oral intake (7.9 v 16 hours; P = 0.008) than the laparoscopic pyeloplasty group. When the laparoscopic pyeloplasty patients were compared with the open pyeloplasty patients, there was no difference in operative time, EBL, time to oral intake, or total hospital costs. The laparoscopically treated patients demonstrated significantly lower analgesic requirements (27.2 v 124.2 mg of morphine sulfate equivalent; P = 0.02) and shorter hospital stays (1.4 v 3.0 days; P = 0.03) than the open surgery patients. The Acucise patients demonstrated shorter operative time (1.7 v 3.4 hours; P < 0.001), shorter hospital stay (1.3 v 3.0 days; P = 0.02), and lower analgesic requirement (22.4 v 124.2 mg of morphine sulfate equivalent; P = 0.02) than the open surgery patients.

CONCLUSIONS

Laparoscopic pyeloplasty achieves a success rate equal to that of open pyeloplasty while providing a recovery similar to that obtained with Acucise endopyelotomy and is gaining popularity as the treatment of choice for UPJ obstruction.

Laparoscopic treatment for ureteropelvic junction obstruction

OBJECTIVES

To assess retrospectively the subjective and objective outcomes achieved after laparoscopic treatment for ureteropelvic junction obstruction at our institutions.

METHODS

Between August 1999 and July 2001, 19 patients (11 women and 8 men), with a mean age of 31.2 years (range 17 to 67), underwent laparoscopic treatment for ureteropelvic junction obstruction. Of these, 17 patients were eligible for postoperative analysis. Nine of these patients had a history of prior surgical intervention on the affected side. The patients were subjectively assessed by an analog pain scale performed before and at least 6 months after surgery. Preoperatively, patients had a diuretic renal scan to confirm the presence of obstruction. Helical computed tomography was also performed preoperatively to assess for the presence of crossing vessels. The renal scan was repeated at least 12 weeks after surgery to document the relief of obstruction objectively.

RESULTS

Helical computed tomography correctly predicted the presence of crossing vessels in 12 patients (63%). The Anderson-Hynes and Fenger pyeloplasty techniques were performed in 16 and 2 patients, respectively. In 1 patient, a small crossing vein over the ureteropelvic junction was identified and divided without complications. The average operative time was 240 minutes (range 128 to 470). The blood loss was minimal, and no open conversions were required. The mean hospital stay was 2.9 days (range 2 to 7). Two postoperative complications occurred (11.7%). The average subjective follow-up was 14.4 months (range 6 to 27), and the average objective follow-up was 7.8 months (range 3 to 12). Of 17 assessable patients, 16 (94%) had subjective and objective success (postoperative improvement in analog pain score and half-life of radiotracer washout). The average split renal function improved from 34.1% to 38.5% (P <0.01).

CONCLUSIONS

On the basis of our data, laparoscopic pyeloplasty has a similar success rate compared with the traditional open approach and better results than other minimally invasive techniques. Longer follow-up and further experience are needed to validate these data.

Laparoscopic pyeloplasty for UPJ obstruction with crossing vessels: contrast-enhanced color Doppler findings and long-term outcome

OBJECTIVES

To evaluate, in the present long-term follow-up study, contrast-enhanced color Doppler imaging (CDI) findings and the clinical outcome of patients with crossing vessels at the obstructed ureteropelvic junction (UPJ), who underwent laparoscopic pyeloplasty. In a previous study, contrast-enhanced CDI proved capable of detecting crossing vessels at the UPJ.

METHODS

A total of 23 patients, who had undergone laparoscopic pyeloplasty and displacement of crossing vessels for UPJ obstruction at least 2 years before this study (mean 27 months), underwent contrast-enhanced CDI, intravenous urography, and renography. Contrast-enhanced CDI was performed using intravenously administered Levovist to assess the displacement of the vessels relative to the UPJ. All patients completed analog follow-up pain scales and quality-of-life assessment questionnaires. RESULTS. Contrast-enhanced CDI revealed a cranial displacement (mean 1.3 cm) of the crossing vessels from the UPJ in all 23 cases. Intravenous urography showed a decrease in the degree of hydronephrosis, with a success rate of 100% in low-grade and 86% in high-grade hydronephrosis. The split renal function improved from 39.7% to 48.1%. Analog pain scale measurements demonstrated a mean improvement in pain of 92% (range 73% to 100%) and a mean quality-of-life score of 94 (range 78 to 100).

CONCLUSIONS

Our series of patients with crossing vessels at the UPJ treated by laparoscopic pyeloplasty showed an excellent long-term successful outcome. Contrast-enhanced CDI allows for preoperative detection, as well as postoperative assessment, of the displacement of the crossing vessel. We recommend that the presence of a crossing vessel be routinely determined preoperatively, because it may influence the choice of treatment modality and thereby the clinical outcome.

Radiologic evaluations affecting surgical technique in ureteropelvic junction obstruction

Ureteropelvic junction obstructions can be explored by radiographic methods including ultrasonography, intravenous pyelography, radionuclide scanning, magnetic resonance imaging and computerized tomography. The decision to operate on an ureteropelvic stricture is best given by the results of a radionuclide scan, which can demonstrate the obstruction. The operative technique is influenced by the presence of a polar artery, as this presence represents a danger when endopyelotomy is performed. The presence of a polar artery may be demonstrated by computerized tomography using helicoidal reconstruction. Magnetic resonance imaging with injection of gadolinium is also useful when available. The outcome and the results of the surgical procedure are also evaluated by radionuclide scanning.

Renal anatomy. Endourologic considerations

The general anatomy of the kidney as applied to minimally invasive surgery is described. The kidney morphometry, the spatial planes, and the perirenal coverings are presented. The kidney's relationship with the diaphragm, ribs, pleura, liver, spleen, and colon is described in importance of intrarenal access. The intrarenal anatomy is also described, based on a large series of three-dimensional endocasts. The anatomic relationships of the intrarenal vessels (arteries and veins) with the kidney collecting system are presented and discussed with respect to intrarenal access by puncture, for endopyelotomy and for nephron-sparing operations.

Laparoscopic pyeloplasty

Laparoscopic pyeloplasty must be compared with open surgery in terms of efficacy and with endopyelotomy in terms of morbidity. All of the series published so far show that the results of laparoscopic pyeloplasty equal those of open surgery. Laparoscopy is associated with a lower morbidity; therefore, it is preferable to open surgery. The morbidity of endopyelotomy is also low, at least when it is performed in a retrograde fashion. The results of endopyelotomy are poor if UPJ obstruction is caused by crossing vessels. In addition, endopyelotomy in this clinical setting carries the risk of hemorrhage. Most adults with symptomatic UPJ obstruction present with crossing vessels at the UPJ. These patients benefit from laparoscopy, and endopyelotomy should be reserved for patients with true intrinsic stenoses. For this reason, preoperative investigation using contemporary imaging techniques is of crucial importance to be able to select the most appropriate surgical method for a given patient. Laparoscopic dismembered pyeloplasty is technically feasible but difficult. The authors prefer nondismembered techniques that yield equally good results in selected patients. Nondismembered pyeloplasty as described by Fenger is easy to perform and well suited for laparoscopy.

Retrograde Acucise endopyelotomy: long-term results

PURPOSE

We evaluated the long-term outcome of retrograde endopyelotomy with the Acucise cutting balloon as a first-line treatment of ureteropelvic junction obstruction (UPJO) in 36 patients (median age 44 years).

PATIENTS

Twenty-three patients had a primary UPJO. The median follow-up in the series was 24 (6-42) months.

RESULTS

Success, defined as a subjective and objective improvement, was obtained in 27 (75%). In multivariate analysis, only the presence of a crossing vessel (45% v. 81%) was a significant covariate for success. The success rates for primary and secondary UPJO were 74% and 77% respectively. The grade of obstruction had no impact on results. The median time to the nine failures was 3 months, and no failure occurred more than 6 months after the endopyelotomy. In 75% of the failures with no crossing vessel, redo retrograde Acucise endopyelotomy was successful.

CONCLUSION

Retrograde Acucise endopyelotomy is an efficient long-term treatment of UPJO with low morbidity. This technique is a reasonable choice for first-line treatment of UPJO.

Crossing vessels at the ureteropelvic junction: detection with contrast-enhanced color Doppler imaging

PURPOSE

To investigate the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) preoperatively by means of contrast agent-enhanced color Doppler imaging (CDI).

MATERIALS AND METHODS

Twenty-nine patients (13 female patients, 16 male patients; age range, 17-76 years; mean age, 45 years) with symptomatic UPJ obstruction were examined with CDI before and after intravenous infusion of the contrast agent. The type (i.e., arterial or venous) and position of the vessel relative to the UPJ (i.e., anterior or posterior) were assessed. The CDI findings were correlated with the surgical findings at laparoscopic pyeloplasty.

RESULTS

Among the 29 patients, crossing vessels were detected with nonenhanced CDI in 15 patients, with enhanced CDI in 22 patients, and with laparoscopy in 23 patients. Enhanced CDI depicted crossing vessels in 22 (96%) of the 23 laparoscopically confirmed cases compared with nonenhanced CDI, which depicted 15 (65%) of the 23 cases. The rate of detecting crossing vessels increased significantly with use of the contrast agent (P < .016, McNemar test).

CONCLUSION

Compared with nonenhanced CDI, contrast-enhanced CDI significantly improves the detection of crossing vessels at the UPJ and is useful in the presurgical evaluation of UPJ obstruction.

The absence of crossing vessels in association with ureteropelvic junction obstruction detected by prenatal ultrasonography

PURPOSE

The widespread use of prenatal ultrasonography has led to a marked increase in the incidence of ureteropelvic junction obstruction presenting in infancy. Which of these prenatally detected lesions requires repair has yet to be fully determined. Attempts to characterize prenatally detected ureteropelvic junction obstruction in regard to symptomatic obstruction detected later in life may provide useful insights into the management of these incidentally discovered lesions. We evaluated the presence of crossing vessels in ureteropelvic junction obstruction identified by prenatal ultrasonography.

MATERIALS AND METHODS

We reviewed the records of patients who underwent dismembered pyeloplasty for primary ureteropelvic junction obstruction with specific attention to the mode of presentation and presence of crossing vessels associated with obstruction.

RESULTS

In 30 patients with a mean age of 6 months ureteropelvic junction obstruction detected prenatally was not associated with a crossing vessel. Ureteropelvic junction obstruction was identified postnatally in 125 patients who underwent open pyeloplasty. It was detected incidentally in 8, of whom crossing vessels were present in 1 (12%). There were signs or symptoms related to ureteropelvic junction obstruction in 117 patients. In contrast to the group with prenatally detected ureteropelvic junction obstruction in which crossing vessels were never noted, crossing vessels were associated with 36 (30%) of the 120 kidneys operated on in this postnatally discovered group.

CONCLUSIONS

No crossing vessels were present in patients with prenatally detected ureteropelvic junction obstruction compared with 30% in symptomatic patients. This finding may reflect the natural history of the disorder, or it may suggest that prenatally identified ureteropelvic junction obstruction is an entity largely different from obstruction presenting later in life.

Vascular anatomy at the ureteropelvic junction

In 65% of the cases regarding the ventral surface of the UPJ, there was a prominent artery, vein, or both in close relation to the ventral surface of the UPJ. In only 6.8% there was an inferior polar artery crossing anteriorly to the UPJ. Therefore, many of the vessels visualized close to the UPJ and described as anomalous and etiologic in obstruction are normal segmental arteries that do not cause UPJ obstruction. In 26.7% of cases regarding the dorsal surface of the UPJ, there was a vessel crossing at or lower than 1.5 cm above the posterior surface of the UPJ. On the basis of our anatomic findings, we advise that in endopyelotomy, the incision along the stenotic UPJ be created only at its lateral aspect.

Endopyelotomy. Retrograde ureteroscopic approach

Ureteroscopy is a natural extension of a urologist's practice. This article describes technical details and results using the ureteroscopic approach to treat ureteropelvic junction obstruction. With a variety of treatment options available, this approach compared favorably.