Functional outcome after pyeloplasty in children: impact of the cause of obstruction and of the mode of presentation

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.

Dual-Energy CT applications in urinary tract cancers: an update

Urothelial tumours are the fourth most common cancer in the world and account for the majority of tumours involving the bladder. The symptom that often leads to diagnosis is the presence of haematuria. Diagnosis is made by cystoscopy, which is currently the gold standard in bladder cancer. Computed tomography (CT) performed with pre- and post-contrastographic phases is essential in order to assess the loco-regional and distant extension of disease. The diagnosis and staging of upper tract urothelial cancer (UTUC) are best done with computed tomography urography and flexible ureteroscopy (URS). In the acquisition protocol of this type of tumour, a urographic phase is mandatory, which allows for an accurate diagnostic assessment of the renal pelvis, ureter and bladder, especially in papillary forms. The use of multiple acquisition phases, especially in this type of patient who will have to perform follow-up CTs, leads to the problem of overexposure to ionising radiation, as well as the frequent administration of iodinated contrast medium. For this reason, in recent year, the focus has been put on advanced technologies such as dual-energy CT (DECT), that is a method that can offer some advantages for both radiologist and patient, in the diagnosis of cancer and, in particular, urinary tract disease.

Renal cortical transit time in the evaluation of prenatally detected presumed pelvi ureteric junction like obstruction: A systematic review

Introduction

Differentiating nonobstructive from obstructive dilatation of the kidney is a clinical dilemma in prenatally detected hydronephrosis. Many radionuclide renogram parameters have been used to differentiate obstructed from non-obstructed units, including cortical transit time (CTT). We evaluate the role of CTT in identifying obstruction through a systematic review.

Methods

A literature search of the MEDLINE, MEDLINE In-Process, and MEDLINE Epub Ahead of Print, EMBASE, Google scholar, Pub Med, and Cochrane Library was done using key words - radionuclide renogram, CTT, parenchymal transit time, cortical transit, renography to identify articles on the subject. The identified articles were assessed for appropriateness and reviewed.

Results

The initial search yielded a total of 1583 articles, after adding the articles from references and applying the inclusion and exclusion criteria a total of 28 articles were selected. CTT showed good inter observer agreement in identifying obstruction. The use of CTT as a single parameter for determining the need for surgery and to identify those kidneys which will have functional improvement after surgery has been evaluated and has been found to be useful. CTT is best used in conjunction with ultrasonography to make clinical decisions.

Conclusion

The commonly used visual method of estimating the CTT, is a promising parameter for the evaluation of prenatally detected pelviureteric junction obstruction. Further well-designed multicenter prospective studies are needed to establish it as the most specific parameter to differentiate obstructive from nonobstructive dilatation of the pelvicalyceal system.

Hydronephrosis in Children Caused by Lower Pole Crossing Vessels-How to Choose the Proper Method of Treatment?

Objectives: Assessment of the efficacy of intraoperative diagnosis between extrinsic and intrinsic UPJO in children. Assessment of the efficacy of laparoscopic vascular-hitch procedure in UPJO caused by lower pole crossing vessels (CV). Materials and Methods: Between 2008 and 2017, 47 laparoscopic procedures were performed with the CV discovered intraoperatively. CV were translocated cephalad, and the UPJ was carefully inspected. The Chapman's vascular hitch procedure was accomplished in the case of decreasing sizes of the pelvis and clear, visible peristalsis of the UPJ (31 patients). In the other cases, Anderson-Hynes (A-H) pyeloplasty with posterior translocation of the CV was performed (16 patients). Results: The median age at operation was 6 years (range 1-16) in VH and 6 years (range 2-17) in A-H (p = 0.4635). Prenatal dilatation of kidney was diagnosed in 18.7% of VH and 10% of A-H cases (p = 0.5474). Success was achieved in 16 (100%) patients in the A-H and in 29 (93.54%) in the VH groups. Two patients (6.5%) in VH required repeated surgery because of a misdiagnosed intrinsic obstruction. Median operation time in VH was 80 min (range 40-105) and was 105 (range 70-225) in A-H (p < 0.05). Conclusions: The intraoperative selection based on intraoperative pelvis and UPJ appearance after vessel transposition is sufficient in majority of cases. Laparoscopic vascular hitch seems to be effective and safe procedure, but can only be performed on carefully selected patients. In case of misdiagnosis, reoperation is possible with the same laparoscopic access.

Radiation-free monitoring in the long-term follow-up of pyeloplasty: Are ultrasound new parameters good enough to evaluate a successful procedure?

INTRODUCTION

Long-term evolution of residual hydronephrosis after successful pyeloplasty is not common. In this report, we have studied new ultrasound parameters, and have investigated the frequency of residual hydronephrosis. We highlight alternative radiation-free monitoring of pediatric pyeloplasties with ultrasound alone.

PATIENTS AND METHODS

Children who had undergone successful open Anderson-Hynes pyeloplasties in the period 2001-2010 were followed up. Exclusion criteria included non-clearly obstructed renography scans (tracer clearance half-time < 20 min), crossing vessels, failed pyeloplasty, bilateral disease, other renal concomitant anomaly, absence of ultrasound measurements, and loss to follow up (<1 year). Postoperative (postoperative) ultrasound parameters were anteroposterior (AP) diameter, pelvis-cortex (P/C) ratio, a proportion that takes in account these two values, enhancing sensitivity to evaluate minimal evolutive changes), and percentage of improvement (PI) in AP diameter (which reflects in relative means the evolution of each AP diameter, being 0% no change, and 100% absence of hydronephrosis) (Figure). Echographic checks were made at 3 and 6 months postoperatively and then yearly afterwards. SPSS software (v. 17.0 IBM, College Station, TX, USA) was used.

RESULTS

Out of 80 pyeloplasties performed in the above-mentioned period, 44 patients (i.e., 44 renal units) fulfilled the inclusion criteria for the main study. The median age at time of operation was 15 months (range 2 months-10.3 years). The median follow-up was 4.5 years (range 1-12 years). The mean preoperative anteroposterior diameter was 26 mm (range 16-54 mm). At the third postoperative check, the mean the PI was 29%, and rose to 53% at 6 months (p=0.027). Posterior controls showed a stable yearly PI during follow-up, without statistically significant variations (40-59% in subsequent years, p>0.5). The P/C ratio had already downgraded significantly at the third postoperative check (4.6 preoperative vs. 1.8 postoperative; p=0.03). A subgroup analysis of failed pyeloplasty (4 renal units) showed all PI < 15% at the third postoperative month (sensitivity 100%, specificity 86%). Complete resolution of hydronephrosis occurred in nine patients (20%).

DISCUSSION

The P/C ratio and PI are new feasible ultrasound parameters in pyeloplasty follow-up. Early improvement in the P/C ratio can be expected and might avoid repeated ionizing scans. A PI>15% in subsequent postoperative checks might be enough for safe monitoring with ultrasound alone. Thus, renograms may be solicited only in these cases where ultrasound parameters do not improve in the first 6 postoperative months. Afterwards, ultrasound parameters often remain stable in the long term. Absence of hydronephrosis could only be documented in the long term in one out of every five patients.

Pyeloplasty in children: perioperative results and long-term outcomes of robotic-assisted laparoscopic surgery compared to open surgery

BACKGROUND

A few studies have compared robotic-assisted laparoscopic pyeloplasty (RALP) with open pyeloplasty (OP) in children, but no previous study includes a long-term follow-up of renal function and hydronephrosis in combination with a thorough prospective follow-up of the RALP patients of at least 2 years.

OBJECTIVE

To analyze perioperative results and long-term outcome of children with obstruction of the ureteropelvic junction, operated on with RALP compared to OP.

PATIENTS AND METHODS

Children ≤15 years operated on with RALP or OP from 2000 through 2013 were reviewed. Patient demographics, perioperative data, postoperative complications, and long-term outcome were evaluated. The outcome was based on pre- and postoperative examination of renal function, hydronephrosis and flank pain.

RESULTS

129 pyeloplasties (84 OP, 39 RALP, 6 reoperations) on 123 patients were included. RALP had significantly longer operative time and shorter postoperative hospital stay, compared to OP. No difference was found in postoperative need of morphine or complication rates. Mean follow-up for RALP with ultrasound was 29 and 25 months with renal scan, compared to 34 and 28 months, respectively, for OP. The success rate for flank pain was 96 and 94 %, for hydronephrosis 93 and 95 %, and renal function 94 and 92 %, for RALP and OP, respectively.

CONCLUSIONS

RALP is a safe method, with advantages compared to OP, and with the same success rate. This study supports the use of RALP in children.

Hydronephrosis: Comparison of extrinsic vessel versus intrinsic ureteropelvic junction obstruction groups and a plea against the vascular hitch procedure

INTRODUCTION

Pediatric ureteropelvic junction obstruction (UPJO) due to an extrinsic crossing vessel (CV) is rare and often remains undiagnosed preoperatively. Vascular hitch procedures are often performed as associated intrinsic obstruction is not expected. We compared data and intravenous urography (IVU) findings of patients with aberrant CV versus those with intrinsic UPJO, all undergoing open dismembered pyeloplasty.

PRIMARY OBJECTIVE

Is accurate pre-operative diagnosis of aberrant CV causing extrinsic UPJO possible?

SECONDARY OBJECTIVE

To assess differences in the demographic, clinical, radiological, intra-operative features and postoperative improvement after pyeloplasty between patients with a CV and those with only intrinsic UPJO.

PATIENTS AND METHODS

Prospective study of all children below 12 years with UPJO presenting to a tertiary referral centre and who underwent open Anderson - Hynes dismembered pyeloplasty between 2003 and 2013 was conducted. Pre-operative investigations included serial ultrasonography, renal dynamic [ethylene di-cysteine (EC)] scan and IVU. These were repeated 3 months after pyeloplasty. Pre-operative IVUs of children with CV were compared with the IVUs of an equal number of similar aged children, randomly selected from the intrinsic obstruction group.

RESULTS

Pyeloplasty was performed in 643 children during the study period. Data of 33 children with aberrant CVs (mean age 6.99 years) were compared with the remaining 610 children (mean age 3.27 years) with only intrinsic obstruction. Highly significant associations of those with CV included age above 2 years, female gender, associated anomalies, abdominal pain in those above 2 years and poor preoperative function on IVU. Specific IVU features which were statistically highly significant in favor of presence of CV were small, intrarenal and globular flat bottomed pelvis. (Figure) Calyceal dilatation was also more prominent in the CV group. A funnel shaped, extrarenal pelvis was highly significant in favor of intrinsic obstruction. There was associated intrinsic obstruction in addition to CV obstruction in 8 children. All children symptomatically improved after pyeloplasty and did well on long term follow up. The majority showed improvement or stabilization of function on EC scan.

DISCUSSION

With the advent of antenatal ultrasonography, most children with UPJO are detected early. Children with CV tend to present later. This is often detected during surgery. Color Doppler is useful but is operator dependant and not performed routinely. In this study, IVU showed the presence of obstruction and loss of function unlike color Doppler, but also revealed specific diagnostic features not previously reported in literature. This can help in accurate preoperative prediction and avoid endopyelotomy, or a dorsal lumbotomy/retroperitoneal approach. Renal function in CVs is expected to be good as the obstruction is thought to be intermittent. However, we noted delayed contrast uptake on IVU in 60.6% and differential renal function on EC scan below 40% in 17 patients (56.6%). These indicate the effect of the obstruction on the renal parenchyma and the importance of early detection. Higher association with other anomalies and higher incidence in females has also not been emphasized in the literature so far. We noted associated intrinsic obstruction in 24.24% patients which is highly significant. This category of patients is likely to be missed and inappropriately treated if a "vascular hitch procedure" is performed. None of our patients had postoperative complications.

CONCLUSIONS

Characteristic features were seen on IVU helping in preoperative diagnosis which can be extrapolated to magnetic resonance urography. There is a higher association of CV in age above 2 years, females, associated congenital anomalies, delayed uptake on IVU and differential renal function below 40% compared to intrinsic obstruction. Associated intrinsic obstruction in 24% with no postoperative complications indicates the superiority of dismembered pyeloplasty over vasculopexy procedures.

Acute pain crisis as a presentation of primary megaureter in children

PURPOSE

Congenital ureteropelvic junction obstruction may present with flank pain, commonly referred to as a Dietl's crisis. We report on a similar presentation of primary megaureter.

METHODS AND MATERIALS

We identified all patients with any diagnosis of megaureter treated at our institution between 1993 and 2009 (n = 465). We included 103 patients with primary megaureter and, of these, identified patients presenting with pain. All patients with secondary megaureter were excluded.

RESULTS

Seventeen patients (20 megaureters) presented with pain and 10 (13 megaureters) presented with an acute pain crisis. Median age at presentation was 77 months. Seven children initially presented to the emergency department for evaluation and two of them required urgent stent placement for intractable pain. Obstruction was diagnosed in 8 patients. Six patients underwent ureteral reimplantation. Four patients were initially observed: one failed observation at 12 months due to worsening hydronephrosis and required surgery, one was lost to follow up, and two are still successfully being followed. All patients who underwent surgery had pain resolution.

CONCLUSION

In this contemporary cohort, approximately 17% of patients with primary megaureter presented with pain and 10% presented with an acute pain crisis. Most presenting in acute pain required surgery, which resolved presenting symptoms.

Unilateral anomalies of kidney development: why is left not right?

Abnormal renal development results in congenital anomalies of the kidney and urinary tract. As many studies suggest that renal malformations are more often found on the left side, a meta-analysis was performed on the distribution of five different unilateral anomalies: multicystic dysplastic kidney, renal agenesis/aplasia, renal ectopia, pelviureteral junction obstruction, and non-obstructive non-refluxing megaureter. Of these anomalies, the left side was affected in 53%, 57%, 56.9%, 63.2%, and 62.5% of patients, respectively, significantly different when compared with an anticipated 50% of left-sided anomalies. An exception to this left-side predominance was found in females with combined genital anomalies and unilateral renal agenesis that commonly present on the right side. The exact mechanisms leading to these lateralizations remain to be determined but may involve vascular development, differential gene expression, or susceptibility to environmental factors such as hypoxia. This remains largely speculative, however, illustrating our limited knowledge of embryogenesis in general and nephrogenesis in particular.

Postoperative outcome following pyeloplasty in children using miniflank incision and transanastomotic stent: a prospective observational study

PURPOSE

To assess the postoperative outcome in children undergoing pyeloplasty, using a single transanastomotic indigenized stent.

METHODS

329 pyeloplasties were performed by small miniflank incision (3-5 cm) with lateral position for unilateral cases and prone position for bilateral cases during 1993-2009. The procedure involved decompression of the hydronephrotic sac, single layer anastomosis at the PUJ using 5/6-0 suture (reduction of the pelvis if required). An indigenized # 6, Teflon transanastomotic stent (TAS) with multiple holes (modified recently to a self-retaining loop in pelvis) was placed and taken out through the renal pelvis and the main skin incision. The stent served both as a nephrostomy and a stent. The kidney was not mobilized during the procedure. Postoperative results were assessed for early complications.

RESULTS

The mean age of the patients was 3.4 years (1 month-14 years). Bilateral simultaneous pyeloplasties were done in 16 cases with a mean age of 5.6 months (2-12). The stent was removed after 4-5 days in most cases after confirming distal flow on clamping. The post-operative complications included slippage of stent (11), blockage/nondrainage (7), difficult retrieval (4), urine leak (4), urinoma (3) and post-operative infection (1). DTPA scan at 3 months follow-up depicted improved drainage in 271 units, preserved renal function in 58 units and improved renal function more than 5% in 246 units.

CONCLUSION

Pyeloplasty using a single Teflon TAS is helpful not only in achieving effective drainage in children undergoing pyeloplasty, but also avoids the complications usually encountered with the use of nephrostomies, or double J stents.

A new modification of dismembered pyeloplasty for primary ureteropelvic junction obstruction

AIM

To present the results of a new modification of dismembered pyeloplasty performed to prevent the occurrence of secondary obstruction.

METHODS

Modified dismembered pyeloplasty was performed in 35 children (age range 3 months to 16 years) who had unilateral ureteropelvic junction obstruction. In postoperative follow-up, presence of hydronephrosis on ultrasonography, differential renal function (DRF) and renal drainage half-time on technetium-99m diethylenetriaminepentaacetic acid (DTPA) renography were recorded and compared with preoperative data.

RESULTS

Mean anteroposterior renal pelvic diameter, mean preoperative DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 61.4 mm, 38.6% and 34.3 min in children with prenatal hydronephrosis, and 67.5 mm, 37.6% and 39.4 min in children that presented with symptoms, respectively. After surgery, mean anteroposterior renal pelvic diameter, mean DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 10.9 mm, 45.9% and 11.9 min in children with prenatal hydronephrosis, and 20 mm, 41.9% and 15.2 min in children that presented with symptoms, respectively. No failure was observed in any patient at an average follow-up of 26 months (range 1-5 years).

CONCLUSIONS

Open dismembered pyeloplasty is the treatment of choice for intrinsic ureteropelvic junction obstruction. The modification of dismembered pyeloplasty that we performed is an alternative for the prevention of secondary obstruction.

The change in renal function in the supranormal hydronephrotic kidney after pyeloplasty

OBJECTIVE

To investigate changes in the differential renal function (DRF) before and after pyeloplasty in renal units with unilateral pelvi-ureteric junction obstruction (PUJO) with supranormal function, and to evaluate the clinical significance.

PATIENTS AND METHODS

We reviewed the medical and radiographic records of 29 children (26 boys and three girls) with unilateral PUJO with a DRF (estimated by (99m)Tc-mercaptoacetyltriglycine renal scintigraphy) of >/= 50% in the affected renal unit, who had pyeloplasty and were followed for >1 year after surgery. Patients were divided into two groups according to the degree of change in their DRF to compare the clinical variables, anteroposterior pelvic diameter and parenchymal thickness measured by renal ultrasonography. The mean (range) follow-up after pyeloplasty was 35 (12-89) months.

RESULTS

After pyeloplasty, although the mean DRF reduced from 53.8% to 51.4%, in seven (24%) patients the DRF decreased significantly (>5%) while most (76%) showed a change of </= 5% of the preoperative function, or further improvement. In the seven patients with a DRF of >/= 55% before surgery, the DRF afterward was >55% in four and 50-55% in one. Between those with and with no significant reduction in DRF, only the preoperative renal parenchymal thickness differed significantly (2.78 vs 5.00 mm, P = 0.006).

CONCLUSION

Supranormal DRF exists and represents the true split function of the affected renal unit in patients with adequate renal parenchyma; these units maintained the supranormal function after pyeloplasty. Parenchymal thickness might be useful to differentiate between the true and false estimates and predict surgical outcome before surgery.

Is retrograde stenting more reliable than antegrade stenting for pyeloplasty in infants and children?

OBJECTIVES

To compare antegrade and retrograde internal double-J stenting for pyeloplasty drainage in children. The success of placing the stent in position and the complications were compared in both groups.

METHODS

Between October 2001 and December 2004, 42 children with unilateral pelviureteral junction obstruction underwent pyeloplasty by a single surgeon. Antegrade and retrograde double-J stenting was attempted in 17 children (mean age 1.3 years) and 25 children (mean age 1.5 years), respectively. Antegrade stenting was attempted during the pelviureteral anastomosis, and the retrograde stent was placed just before the operation by cystoscopy. Fluoroscopy was not routinely used to confirm stent placement in either group. The stents were removed 4 weeks later at cystoscopy.

RESULTS

Successful stent placement without malpositioning was achieved in 14 (82%) of 17 and 24 (96%) of 25 children, respectively, in the antegrade and retrograde groups. The cause of unsuccessful stenting in both groups was the inability to cross the ureterovesical junction. The mean time taken for retrograde stenting was 9 minutes (range 6 to 15). All children with successful stent placement by either technique were discharged within 72 hours after the operation. The hospital stay for children with unsuccessful double-J stent placement varied from 7 to 10 days. No stent malpositioning occurred with retrograde stenting; 1 child in the antegrade stent group had a malpositioned stent in the distal ureter, which was retrieved at ureteroscopy.

CONCLUSIONS

In our experience, retrograde double-J stenting seems more reliable than antegrade stenting for pediatric pyeloplasty, with greater success and lower complication rates.

Moderate approach to the antenatally diagnosed unilateral ureteropelvic junction obstruction: experience with 93 patients

To evaluate the results of the treatment in patients with antenatally detected unilateral ureteropelvic junction obstruction. Ninety-three patients were analyzed according to the radiologic and scintigraphic findings and mode of the treatment. Fifty-eight patients were treated surgically while 29 patients were followed conservatively. All patients were reevaluated at the first year of the treatment with diuretic renogram (DR). Follow-up procedure was finished at first postoperative year in surgically treated patients, while mean follow-up duration was 14.9+/-6.9 months for the conservatively treated group. In the operated group, pelvic diameter was greater than 20 mm on ultrasound and overall rate of mean split renal function was 38.65+/-9.55% on DR and 39.65+/-12.55% at first postoperative year. In the conservatively treated group, mean split renal function was 46.17+/-3.42 at the beginning and 47.48+/-4.00 at first year of follow-up. Sixty-three percent of the patients underwent pyeloplasty while 83% of them were showing obstructive pattern on DR. We believed that surgery should be done in renal units which showed pelvic diameter greater than 20 mm and less than 40% of split renal function, while others might be followed conservatively, with or without an obstructive pattern on DR.

Congenital unilateral hydronephrosis: a review of the impact of diuretic renography on clinical treatment

PURPOSE

The natural history of and optimal treatment for asymptomatic congenital hydronephrosis is unknown, mainly because most published series are nonrandomized or retrospective with nonstandardized followup regimens. In this survey we provide an overview of the different strategies used for the treatment of congenital unilateral hydronephrosis.

MATERIALS AND METHODS

A comprehensive literature review of clinical studies of asymptomatic congenital unilateral hydronephrosis is presented.

RESULTS

Different criteria for surgical intervention and different followup regimens have been used. Identification of the population at risk has been attempted but results are ambiguous. Surgery is done in approximately 25% of cases when using deteriorating differential function, symptoms and/or increasing hydronephrosis as criteria for operation. A nonstandardized renographic assessment does not compromise evaluation of the ideal followup but it may compromise the functional outcome.

CONCLUSIONS

More studies of kidneys with decreased function, severe hydronephrosis or poor drainage investigated with a standardized protocol are needed to clarify the natural history and establish optimal guidelines for treatment and followup.

Role of multiphasic helical computed tomography in planning surgical treatment for pelvi-ureteric junction obstruction

OBJECTIVE

To evaluate the role of multiphasic helical computed tomography (CT) in planning surgical treatment for pelvi-ureteric junction obstruction (PUJO).

PATIENTS AND METHODS

Multiphasic helical CT was used in 60 consecutive patients (mean age 32 years, sd 13.72) with primary PUJO. The different images were interpreted before surgery by a urologist and radiologist. The number, type and relation of the crossing vessels to the PUJ were detected. Pyeloplasty (open or laparoscopic) was used in patients where there was a significant crossing vessel (i.e. > 2 mm in diameter and passing at the PUJ) or with ballooning of the renal pelvis. Endopyelotomy (antegrade or retrograde) was used in the other patients. Subjective and objective success rates were determined 3-6 months after treatment and then every 6 months.

RESULTS

Hyperdense renal stones were detected in precontrast images in 15 patients, significant crossing vessels in 33 (55%), and anterior malrotation of the renal pelvis in 23 (38%; 19 associated with significant crossing vessels, i.e. ureterovascular hydronephrosis). A large para-pelvic cyst compressing the PUJ and upper ureter was detected in one patient. Pyeloplasty was used in 45 patients, among whom the sensitivity of multiphasic helical CT in detecting crossing vessels was 97%, the specificity 92% and accuracy 96%. Uncomplicated endopyelotomy was used in 14 patients and percutaneous aspiration of the para-pelvic cyst in one.

CONCLUSION

Multiphasic helical CT can accurately delineate the spatial anatomy of the renal and peri-renal area; it may be important in planning surgical treatment for PUJO, especially when endopyelotomy is considered.