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

The missed crossing vessel during open pyeloplasty: a potential advantage of the robot-assisted approach in children

OBJECTIVE

To investigate whether the panoramic view offered by robot-assisted laparoscopic pyeloplasty (RALP) reduces the likelihood of missing a crossing vessel compared to open pyeloplasty in cases where initial pyeloplasty fails.

METHODS

A single institution redo-pyeloplasty database was reviewed for children treated between January 2012 to July 2023. Clinical history, imaging and operative details were reviewed to identify the etiology for the redo procedure.

RESULTS

Cohort consisted of 45 patients undergoing a redo RALP during the study period. 29 of 45 patients had an initial open surgical approach, whereas 16 had an initial RALP. 10 patients were noted to have a missed crossing vessel on redo pyeloplasty - 9 had an initial open approach whereas 1 had an initial RALP (p<0.0001).

CONCLUSIONS

RALP may reduce the risk of missing a crossing vessel due to the panoramic view of the surgical field intrinsic to an intraperitoneal RALP approach.

Contemporary status of diagnostic endoluminal ultrasound and optical coherence tomography in the ureter

Objective

To evaluate via a review of published literature, the efficacy of endoluminal ultrasound (ELUS) and optical coherence tomography (OCT) in the following ureteric diseases: urolithiasis, upper tract urothelial carcinoma, stricture disease and pelvic-ureteric junction obstruction (PUJO).

Patients and methods

Ureteric high-frequency ELUS provides 360° imaging, to a depth of 20 mm, and has been demonstrated to assess ureteric stricture length, degree of fibrosis and aetiology. OCT produces high-quality images with a penetration depth of 2 mm. ELUS has proven to be useful at the time of endopyelotomy for PUJO as it can identify crossing vessels, some not detectable on CT angiography, allowing the urologist to avoid these when making their incision. Ureteric ELUS may be utilised for submucosal ureteric stones as they are highly visible. Endoluminal ultrasound may be deployed in the case of known sub-mucosal urolithiasis when the ureter appears stone-free. It may help identify sub-mucosal stones or stones within diverticulum.

Results

Endoluminal ultrasound has been analysed for its use in determining muscle-invasive urothelial carcinoma of the ureter. The PPV for ≥pT2 was only 16.7% in one study of six patients with MIBC and 76.2% in 21 patients with

Conclusions

Ureteric ELUS has been reported to be a useful tool in endopyelotomy, urolithiasis and stricture disease. The staging of ureteric urothelial carcinoma remains unsatisfactory with current imaging techniques and biopsy methods, and, based on the current literature, ELUS does not appear to have a strong enough PPV to determine muscle invasion. Ureteric OCT may be a useful tool in the future staging of upper tract urothelial carcinoma, particularly in differentiating the stage of small tumours. Further studies are needed in this area.

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Key Words

• endoluminal ultrasound
• optical coherence tomography
• ureter

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MESH Headings Collapse

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Affiliation(s)

Samuel Sii Department of SurgeryUniversity of Melbourne, Austin HealthMelbourneVictoriaAustralia
Jeremy Bolton Monash UniversityMelbourneVictoriaAustralia
Jake Tempo Department of SurgeryUniversity of Melbourne, Austin HealthMelbourneVictoriaAustralia
Damien Bolton Department of SurgeryUniversity of Melbourne, Austin HealthMelbourneVictoriaAustralia

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Initial experiences with preoperative three-dimensional image reconstruction technology in laparoscopic pyeloplasty for ureteropelvic junction obstruction

Background

To explore the clinical value of three-dimensional image reconstruction technology (3DIT) on preoperative surgical planning and perioperative outcomes in laparoscopic pyeloplasty (LP).

Methods

Data of 25 patients with ureteropelvic junction obstruction (UPJO) admitted to our hospital from January 2018 to January 2019 was analyzed retrospectively. All patients underwent preoperative enhanced computed tomography (CT) scanning. In the 12 cases in the 3DIT group, preoperative planning involved the use of virtual operation and morphometry based on reconstruction of the CT data into three-dimensional (3D) images. Surgery in the other 13 cases was performed with traditional CT examination. Demographic, surgical outcome, and postoperative parameters were compared between these two groups.

Results

Reconstructed 3D images clearly showed the spatial structural relationships between the UPJO and surrounding blood vessels. In all 25 cases surgery was completed with no conversion to open surgery. Preoperative 3DIT analyses resulted in significant improvements to mean operation time (107.76 vs. 141.58 min, P=0.024), mean time of dissociating ureteropelvic junction (UPJ) (11.26 vs. 19.40 min, P=0.020), and mean estimated blood loss volume (23.84 vs. 49.16 mL, P=0.028). There were no statistically significant differences in perioperative complications, postoperative hospital stays or postoperative drainage time.

Conclusions

3DIT based on enhanced CT scans is of clinical value in the treatment of UPJO, as it can provide accurate anatomical information and reliable guidance for preoperative operation planning, and it facilitates image-guided LP.

Histopathology in Ureteropelvic Junction Obstruction With and Without Crossing Vessels

OBJECTIVE

To determine if the histopathology of the ureteropelvic junction differs between those with and without crossing vessels who present with a ureteropelvic junction obstruction (UPJO).

MATERIALS AND METHODS

Our database was queried for patients undergoing pyeloplasty (Current procedural terminology 50400, 50405, and 50544) between June 1, 2002, and March 10, 2016. We excluded patients with other renal anatomic abnormalities and patients undergoing surgery for upper tract tumor. One genitourinary pathologist reviewed all slides for muscle hypertrophy, fibrosis, edema, and inflammation. Statistics were modeled in SAS 9.4 (SAS, Cary, NC) using logistic regression with maximum likelihood.

RESULTS

A total of 178 patients met the inclusion criteria, and pathology slides were available for 136 patients. Thirty-three patients had crossing vessels in association with a UPJO. The degrees of muscle hypertrophy (P = .89) and fibrosis (P = .17) were not predictive of etiology. The odds of a crossing vessel increased by 4.3 times (95% confidence interval 1.8-9.9) when edema was present (P = .009) and by 4.4 (95% confidence interval 1.4-13.7) times when inflammation was present (P = .0103).

CONCLUSION

In the largest pathology series to date, histopathology showed increased inflammation in the presence of a crossing vessel but a similar composition of muscle and fibrosis. These data suggest that UPJO with an associated lower-pole vessel may represent a chronic process, which would explain why patients with a crossing vessel present later in life.

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.

Laparoscopic Pyeloplasty: Always Dismembered?

OBJECTIVE

To compare three laparoscopic surgical techniques for the treatment of ureteropelvic junction obstruction (UPJO), assessing their difficulty, operating time, effectiveness, and complications.

MATERIALS AND METHODS

The clinical histories of 54 patients with UPJO who underwent a laparoscopic procedure between June 2003 and September 2013 were reviewed. Anderson-Hynes (A-H) pyeloplasty was performed on 34 patients, nondismembered pyeloplasty on 11 cases (8 Y-V Foley plasty and 3 Fenger plasty), and cephalad vascular displacement or Hellström technique (HT) on 9 patients. The patients were selected for the different techniques depending on the findings during the procedures, according to renal pelvic size and the presence of crossing vessels. We compared the techniques according to intraoperative and postoperative outcomes. Complications were interpreted following the Clavien-Dindo classification. The success rate was defined as the absence of clinical symptoms and normal diuretic renography. Analysis of variance and chi-square tests were used for the statistical analysis.

RESULTS

Mean follow-up was 55.58 months. The success rate achieved was 88.5% for A-H pyeloplasty, 90.9% for nondismembered pyeloplasty, and 100% for HT (p > 0.05). HT was the least time-consuming: 124 ± 30 vs 202 ± 44 minutes of A-H pyeloplasty and 147 ± 27 minutes of nondismembered plasty (p < 0.005). Mean hospital stay was 6.7 ± 1.4 days for A-H pyeloplasty, 6.6 ± 2 days for nondismembered pyeloplasty, and 3.42 ± 1.5 days for HT (p < 0.05). The postoperative complication rate was 21.1% for A-H pyeloplasty, 18.8% for nondismembered pyeloplasty, and 12.5% for HT (p > 0.05). None of the cases required open surgery, and urinary fistula was the most frequent complication.

CONCLUSION

Intraoperative observation of ureteropelvic junction allows selecting cases to undergo nondismembered pyeloplasty techniques, achieving similar results to A-H pyeloplasty, reducing operating time, complication rate, and hospital stay.

Long-term results with the laparoscopic transposition of renal lower pole crossing vessels

BACKGROUND

For the treatment of ureterovascular pelviureteric junction obstruction (PUJO), transposition of lower pole crossing vessels (LPCV) has been described as an alternative to dismembered pyeloplasty.

PURPOSE

To report on the long-term follow-up of children after laparoscopic transposition of LPCV.

METHODS

A retrospective analysis of 70 children consecutively treated by laparoscopic transposition of LPCV. Candidate patients were selected on the basis of clinical history, renal ultrasound (US), and pre-operative mercaptoacetyltriglycine (MAG-3) scan. Selection criteria included: presence of LPCV with SFU Grade 1-2 hydronephrosis, impaired drainage on MAG-3 and intraoperative normal pelviureteric junction (PUJ) and ureter peristalsis. Thinned parenchyma, impaired renal function, or history of prenatal hydronephrosis were not considered as exclusion criteria. Children were clinically followed up with US and MAG-3 scan. Success was defined by symptom resolution with improvement in hydronephrosis.

RESULTS

Seventy children, aged 8.3 years (range 2.75-16.0), were selected. Procedures were performed through transperitoneal laparoscopy (n = 42) or were robotic-assisted (n = 28). Operative time was 120 min and length of hospital stay was 2 days. The outcome was successful in 67/70 patients (96%), with a median follow-up of 52 months (range 13-114). There were three failures in children who eventually underwent dismembered pyeloplasty for a symptomatic, undiagnosed, intrinsic PUJ obstruction. Two of them had been postnatally followed for a resolving prenatally diagnosed hydronephrosis. Three children became free of symptoms, had improved hydronephrosis, but still showed impaired drainage on MAG-3 and are being closely followed up.

DISCUSSION

Although this procedure proves to have long-term efficiency in selected indications, the main challenge is to intraoperatively ascertain the absence of associated intrinsic stenosis. Objective criteria remain difficult to establish, but intraoperative findings, including dependent, funnel-shaped, normal-looking PUJ with decreasing hydronephrosis after pelvis and LPCV mobilisation, and efficient peristalsis across the PUJ under intraoperative diuretic test, represent a low likelihood of associated intrinsic stenosis. Ipsilateral impaired renal function doesn't seem to be associated with an adverse outcome. In contrast, a prenatal history of mild or self-resolving hydronephrosis in a patient later presenting with intermittent dilatation, raises the suspicion of associated intrinsic PUJ obstruction, as it is associated with a higher risk of failure.

CONCLUSION

With a long postoperative follow-up, the robotic-assisted or laparoscopic vascular hitch procedure has been successful in treating a selected group of children with obstructive LPCV, and represents a safe and reliable alternative to standard dismembered pyeloplasty in the absence of intrinsic PUJO suspected on prenatal US.

Differences between intrinsic and extrinsic ureteropelvic junction obstruction related to crossing vessels: histology and functional analyses

PURPOSE

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO); extrinsic UPJO are rare and often due to crossing vessels (CVs).

METHODS

We retrospectively reviewed all data of children with UPJO that underwent surgery in our institution from 2004 to 2011. Analyses included age at surgery, gender, preoperative and postoperative results of ultrasound and renal scans [differential renal function (DRF); signs of obstruction], and pathology reports. Available histological specimens of cases with CV were compared to a random selection of intrinsic cases in a blinded fashion. After additional Masson's trichrome staining, the specimens were scored for fibrosis, muscular hypertrophy, and chronic inflammation.

RESULTS

Out of 139 patients with UPJO, 39 cases were associated with CV. Median age at surgery was 68 months (range 2-194) in the CV group and 11.5 months (range 0-188) in IUPJO group. Laparoscopic dismembered pyeloplasty (LDMP) was carried out in 134 and open DMP in five patients. Preoperative ultrasound identified 28/39 cases with CV. DRF below 40 % was more frequently seen in CV patients (p = 0.020). Histological analyses revealed no differences between the CV and IUPJO specimens in total. CV patients with higher grades of muscular hypertrophy had lower preoperative DRF, compared to those with higher preoperative DRF (p = 0.026). Functional recovery after (L)DMP was excellent in both groups.

CONCLUSION

We could not find any significant histological differences between CV and IUPJO in children. To obtain excellent functional recovery, surgical procedures with a definite correction of the UPJ should be preferred in paediatric patients with CV.

Laparoscopic pyeloplasty with cephalad translocation of the crossing vessel - a new approach to the Hellström technique

Introduction

It is believed that lower pole crossing vessels may play an important role in the etiology of ureteropelvic junction obstruction (UPJO). A conventional operative technique, which seems to be widely used in patients with UPJO, is Anderson-Hynes (A-H) plasty with dorsal transposition of the vessel. An attractive alternative to dorsal transposition of the vessel might be its cephalad translocation.

Aim

To assess the effectiveness of cephalad translocation of the crossing vessel in patients who underwent laparoscopic A-H or Y-V pyeloplasty.

Material and methods

Eighty-five patients were included in the study. To assess the effectiveness of cephalad translocation of the crossing vessel in patients who underwent laparoscopic pyeloplasty, the results of the procedure were compared to the results of laparoscopic pyeloplasties performed in patients without crossing vessels (control group). Success was defined as the following factors taken collectively: 80% or greater pain relief according to VAS, no sign of obstruction on intravenous urography (patent UPJ), decreasing excretion curve with T1/2 < 12 min, and improved or stable differential renal function on diuretic renography.

Results

The mean follow-up was 53.7 months. There was no statistically significant difference in the success rate between the compared groups (group 1 – cases with cephalad translocation of the crossing artery, and group 2 – cases without crossing vessels) in patients who underwent A-H plasty or Y-V plasty.

Conclusions

The analysis of our data seems to indicate that cephalad translocation of the anterior crossing vessel gives good therapeutic results in patients who undergo laparoscopic pyeloplasty.

Failed pyeloplasty in children: Is robot-assisted laparoscopic reoperative repair feasible?

OBJECTIVE

In this study we aim to demonstrate that robot-assisted laparoscopic (RAL) reoperative repair is safe and effective and even less technically demanding than open repair for recurrent ureteropelvic-junction obstruction (UPJO).

STUDY DESIGN

A retrospective study was conducted of all cases of failed open pyeloplasties who underwent RAL reoperative repair at our institution between January 2010 and December 2013. The general surgical procedure was the same we previously described for robot-assisted laparoscopic pyeloplasty. Success was defined as: improvement in the degree of hydronephrosis at ultrasound, improvement of diuretic washout time at postoperative diuretic renogram (<15 min), improvement or at least stable differential renal function and absence of symptoms. These radiographic and symptomatic criteria of success were considered the primary outcomes. Secondary outcomes included complications and length of hospital stay.

RESULTS

Between 2000 and 2013 a total of 153 patients underwent open Anderson-Hynes dismembered pyeloplasty. Of these 9 (6%) had recurrent UPJO. Four patients underwent open redo pyeloplasty. As a result, our study population comprised 5 children who underwent reoperative RALP repair. Patient characteristics and outcomes are summarized in the table below. Our success rate was 100%.

DISCUSSION

Due to the low failure rate of open dismembered pyeloplasty there is no consensus on the best surgical approach for recurrent obstruction. While endoscopic approaches have been favored in adults, children have shown better success rates with repeat pyeloplasty. Laparoscopic salvage pyeloplasty for failed open procedures has become more popular and has been shown to result in excellent outcomes while providing the advantages of minimally invasive surgery. To date, the literature regarding the use of RALP for failed open procedures in the pediatric population is scarce. Only 2 pediatric series of robotic reoperative pyeloplasty have been reported by Helmal et al. (9 patients) and Lindgren et al. (16 patients) with a success rate of 100 and 88%, respectively. Although this is one of the first published studies about robot-assisted laparoscopic reoperative repair for failed open pyeloplasty in pediatric patients, we acknowledge the limitations of our study due to the small number of patients, its retrospective nature and limited follow-up time.

CONCLUSIONS

The incidence of failed open pyeloplasty is as low as 5% and management remains controversial. As reported by other authors, we believe that crossing vessels play a particularly important role in secondary obstruction and adversely impact the outcome. Redo pyeloplasty, open or minimally invasive, is associated with high success rates (80-100%) and therefore considered the treatment of choice by the majority of authors nowadays. Additionally, RALP for secondary procedures has demonstrated to be safe and even less technically demanding when compared to the open approach, providing the advantages of minimally invasive surgery.

Laparoscopic stepwise-cut double initial stay suture pyeloplasty: our novel surgical technique

OBJECTIVE

To describe a novel surgical technique, laparoscopic stepwise-cut double initial stay suture (LASDISS) pyeloplasty for ureteropelvic junction obstruction (UPJO). Additionally, we evaluated the safety and short-term results.

MATERIALS AND METHODS

This was a nonrandomized study with a series of 6 patients with UPJO, operated on between March 2012 and August 2013. Perioperative and short-term outcomes were evaluated. In brief, a "T shape cut" was performed from the dilated pelvis to the ureter. The initial stay suture was placed between the lower edge of the pelvis and the distal end of the spatulated anterolateral part of the ureter. The pelvis was closed with a continuous suture starting from the opened upper edge of the pelvis that was secured after leaving enough space for ureteral anastomosis. The second initial stay suture was placed after passing the ureter and pelvis two times. The dilated part of the renal pelvis and the stenotic segment were excised. A double-J stent was inserted. The remaining space between the two initial sutures was closed with these continuous sutures.

RESULTS

We performed the LASDISS pyeloplasty technique in all cases. Median operation time was 177 minutes (range, 100-290 minutes). Mean follow-up was 7.5 months (range, 3-18 months). The mean pre- and postoperative split renal function on diuretic renography was 33% (range, 25%-56%) and 42% (range, 30%-52%), respectively.

CONCLUSIONS

The LASDISS pyeloplasty surgical technique represents a safe and effective option in surgical treatment of UPJO.

Multidetector CT of vascular compression syndromes in the abdomen and pelvis

Certain abdominopelvic vascular structures may be compressed by adjacent anatomic structures or may cause compression of adjacent hollow viscera. Such compressions may be asymptomatic; when symptomatic, however, they can lead to a variety of uncommon syndromes in the abdomen and pelvis, including median arcuate ligament syndrome, May-Thurner syndrome, nutcracker syndrome, superior mesenteric artery syndrome, ureteropelvic junction obstruction, ovarian vein syndrome, and other forms of ureteral compression. These syndromes, the pathogenesis of some of which remains controversial, can result in nonspecific symptoms of epigastric or flank pain, weight loss, nausea and vomiting, hematuria, or urinary tract infection. Direct venography or duplex ultrasonography can provide hemodynamic information in cases of vascular compression. However, multidetector computed tomography is particularly useful in that it allows a comprehensive single-study evaluation of the anatomy and resultant morphologic changes. Anatomic findings that can predispose to these syndromes may be encountered in patients who are undergoing imaging for unrelated reasons. However, the diagnosis of these syndromes should not be made on the basis of imaging findings alone. Severely symptomatic patients require treatment, which is generally surgical, although endovascular techniques are increasingly being used to treat venous compressions.

Is the pelviureteric junction an anatomical entity?

OBJECTIVE

The concept of the pelviureteric junction has existed for more than a century and yet there is no clear anatomical definition of this junction. This systematic review addresses the question of whether the human pelviureteric junction is a discrete anatomical entity.

METHODS

A systematic literature review was undertaken to investigate the normal gross and microscopic anatomy of the pelviureteric junction using the electronic databases MEDLINE, PubMed, Cochrane Library and Google Scholar.

RESULTS

In most individuals there is a gradual transition between the renal pelvis and ureter with no external features indicating the presence of a discrete pelviureteric 'junction'. Internally, however, luminal mucosal folds are prominent in this region. There is no consensus on the arrangement of muscle fibers at the pelviureteric junction (which may be age-dependent) although some studies suggest a focal thickening in the muscle wall consistent with physiological observations suggesting a high pressure zone capable of regulating urine flow. Studies of innervation have shown no evidence of specialization at this site.

CONCLUSIONS

There is some evidence that a pelviureteric region can be delineated anatomically and physiologically. However, although it may be a useful clinical concept, there is no sound anatomical basis for an actual pelviureteric junction.

Navigating the difficult robotic assisted pyeloplasty

Pyeloplasty is the gold standard therapy for ureteropelvic junction obstruction. Robotic assisted pyeloplasty has been widely adopted by urologists with and without prior laparoscopic pyeloplasty experience. However, difficult situations encountered during robotic assisted pyeloplasty can significantly add to the difficulty of the operation. This paper provides tips for patient positioning, port placement, robot docking, and intraoperative dissection and repair in patients with the difficult situations of obesity, large floppy liver, difficult to reflect colon (transmesenteric pyeloplasty), crossing vessels, large calculi, and previous attempts at ureteropelvic junction repair. Techniques presented in this paper may aid in the successful completion of robotic assisted pyeloplasty in the face of the difficult situations noted above.

[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.

Laparoscopic management of ureteropelvic junction obstruction by division of the aberrant vein and cephalad relocation of the crossing artery: a long-term follow-up of 42 cases

OBJECTIVE

It was intended to demonstrate the update report of our experience with laparoscopic management of ureteropelvic junction obstruction by division of the aberrant vein and cephalad relocation of the crossing artery in a large group of patients with long-term follow-up.

PATIENTS AND METHODS

Three hundred and twenty-nine patients were candidate to undergo laparoscopic transperitoneal ureteropelvic junction obstruction management from June 2001 to March 2009. Intraoperatively, lower pole crossing vessels were identified in 117 patients (35.5%). After division of the aberrant vein, the crossing artery was relocated cephalad and fixed to peripelvic tissue. Renal pelvic emptying with proper pyeloureteral peristalsis was considered in 71 patients, so neither pyeloplasty nor Double-J stent was fixed for them. Postoperative outcomes were assessed with intravenous urography and/or diethylene triamine pentaacetic acid-diuretic renal scan.

RESULTS

Of the 71 patients who underwent this laparoscopic approach, 42 were completely followed over a long-term period. The mean age of patients was 27 (7-69) years. The mean operative duration was 133 (55-185) minutes and blood loss was negligible. The mean hospital stay was 2.8 (1-7) days and mean follow-up was 29 (3-84) months. Overall success rate was 90% and recurrence of obstruction was noted in two patients. No significant complications were observed.

CONCLUSION

Cephalad relocation of the lower pole crossing artery after division of the crossing vein in selected cases could be an ideal alternative for dismembered pyeloplasty with noticeable outcomes in long-term follow-up.

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.

Pyeloplasty in children: is there a difference in patients with or without crossing lower pole vessel?

INTRODUCTION

Most of the children with hydronephrosis do not require any surgical intervention. However, in individual cases, irreversible loss of renal function can develop. Predictive criteria have been proven ineffective so far in determining in which children obstruction will lead to renal damage. The aim of our retrospective study was to determine the role of a crossing lower pole vessel (CV) in children undergoing pyeloplasty.

MATERIALS AND METHODS

Between 1996 and 2003, 137 patients (age between 6 weeks and 16 years) with unilateral ureteropelvic junction obstruction and no associated urological pathologies underwent Anderson-Hynes dismembered pyeloplasty. A total of 112 patients were evaluated with complete data. One of the following criteria was considered to be indication for surgery in children with grade 4 hydronephrosis: differential renal function (DRF) <40%; clinical symptoms such as pyolenephritis and flank pain; during follow-up renographies, a reduction of DRF >10% and washout patterns II or III b according to O'Reilly. We looked at the age during surgery and the kind of presentation. DRF was measured using diuretic renography preoperatively and 1 year postoperatively. A postoperative change in DRF of group A (children without CV, n = 84) was compared to that in group B (children with CV, n = 28).

RESULTS

Median age at the time of surgery was 5 months in group A compared to 23 months in group B. Only in 21.4% of the children with CV compared to 60.7% without CV hydronephrosis was diagnosed by ultrasound examination antenatally. We found a preoperative DRF of 42.4% +/- 11.2 SD in group A, and of 38.9% +/- 11.7 SD in group B. The percentage of postoperative improvement was 3.3% in group A and 15.4% in group B.

CONCLUSIONS

Children with ureteropelvic junction obstruction and CV received a delayed surgical treatment and showed a greater reduction in differential renal function preoperatively, in contrast to patients without CV. Our data show that CV is a risk factor for deterioration of renal function in children with hydronephrosis and we advocate for an early pyeloplasty in these children, especially if they have a high-grade dilatation and equivocal washout patterns in diuretic renographies. Further prospective studies are necessary in order to understand the natural history of CV and to reveal the importance of the crossing lower pole vessel as a structural anomaly lacking maturation.

Ureteropelvic junction obstruction secondary to crossing vessels-to transpose or not? The robotic experience

PURPOSE

We compared the surgical outcomes of robot assisted laparoscopic dismembered pyeloplasty in patients presenting with anterior crossing vessels with and without transposition of the crossing vessel.

MATERIALS AND METHODS

A total of 107 patients with ureteropelvic junction obstruction underwent robot assisted laparoscopic dismembered pyeloplasty. Evaluation of surgical success was based on validated pain scores, diuretic renography and imaging results, including excretory urography, computerized tomography or ultrasound.

RESULTS

Anterior crossing vessels were identified in 48 patients (44.9%) and vessels were transposed in 18 (37.5%) (group 1). No transposition was performed in 30 patients (62.5%) (group 2). Mean radiological followup was 52.9 weeks in group 1 and 65.3 weeks in group 2 (p = 0.181). Mean pain score on a scale of 10 was 0.82 in group 1 and 0.74 in group 2 (p = 0.917). A Whitaker test performed in 3 patients with persistent pain was negative. Preoperatively mean differential function on the affected side was 35.1% in group 1 and 36.9% in group 2 (p = 0.133). Half-time was calculated as a mean of 46.3 minutes in group 1 and 49.4 minutes in group 2 (p = 0.541). In groups 1 and 2 mean postoperative differential function improved to 41.1% and 40.9%, and mean half-time improved to 7.43 and 8.03 minutes, respectively (p = 0.491). A comparison of preoperative and postoperative differential function, and half-time in each group showed a statistically significant difference. The radiographic and symptomatic success rate was 100% with no open conversion and recurrence.

CONCLUSIONS

Comparison of robot assisted laparoscopic dismembered pyeloplasty outcomes revealed similar success rates in terms of the change in symptoms and renal function in patients with or without anterior crossing vessel transposition. Transposition of crossing vessel should only be performed when the anatomical relation dictates and it should be an intraoperative decision.

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.

Reliability and validity of endoluminal sonography in a porcine model of ureteropelvic junction obstruction

PURPOSE

The objective of this study was to evaluate the usefulness and reliability of endoluminal ultrasonography in ureteropelvic junction (UPJ) obstruction and to describe the changes in sonographic appearance that take place during obstruction and after treatment.

MATERIALS AND METHODS

Twelve large healthy white female pigs were randomly divided into two groups: Group 1 (laparoscopic pyeloplasty) and group 2 (cutting balloon endopyelotomy). Percutaneous and endoluminal ultrasonographic and fluoroscopic studies were analyzed during the three phases of the study. The first phase included premodel documentation of a normal urinary tract and laparoscopic UPJ obstruction. During the second phase 6 weeks later, diagnosis and endourologic treatment were performed. Fifteen weeks after obstruction management, follow-up imaging studies and postmortem evaluation of all animals were performed.

RESULTS

At the end of the study, group 1 had a lesser degree of fibrosis in the muscle-adventitia layers and periureteral repercussion, as well as a better peristaltic recovery. The animal study shows a positive correlation among the results of the pathologic and the endoluminal ultrasonographic studies in UPJ obstruction.

CONCLUSIONS

Endoluminal ultrasonography provides excellent information regarding ureteral and periureteral anatomy. Among the two techniques evaluated in the study, laparoscopic pyeloplasty caused the lesser reaction at the reconstructed area. Fibrous replacement at the muscle-adventitia layers and periureteral area may be useful as indicators of the better therapeutic technique as well as for the assessment of post-therapeutic ureteral evolution and recurrences.

Evaluation of the upper urinary tract using transureteric ultrasound--a review of the technique and typical imaging appearances

Ureteric strictures and pelviureteric junction obstruction often present a diagnostic conundrum to radiologists, particularly after the first-line investigations have failed to provide a definitive answer. Transureteric ultrasonography (TUU) is a relatively novel technique performed by the radiologist, which uses a miniature endoluminal ultrasound probe to interrogate the ureteric anatomy and peri-ureteric soft tissues. In this review, we discuss how TUU is performed, and the normal imaging appearances of the ureter and surrounding anatomical structures. We also focus on the various pathological processes that can be accurately evaluated or diagnosed using TUU including lymphadenopathy, calculi, ureteric neoplasms, ureteritis, crossing vessels and aneurysms. As TUU is not well established in UK practice as yet, we suggest possible indications for its use in the diagnostic work-up of urological patients and future applications.

Functional Assessment of Crossing Vessels as Etiology of Ureteropelvic Junction Obstruction

OBJECTIVES

The contribution of crossing vessels to ureteropelvic junction (UPJ) obstruction is controversial. We performed a pilot study on patients undergoing laparoscopic pyeloplasty in whom an intraoperative Whitaker test was performed before and after repositioning a crossing vessel to determine its effect on collecting system drainage.

METHODS

From August 2004 to July 2005, 10 patients with UPJ obstruction scheduled to undergo laparoscopic pyeloplasty were prospectively enrolled in this study. Routine laparoscopic access to the renal pelvis was obtained, and a crossing vessel, if present, was identified. Before mobilization of the UPJ or the crossing vessel, an intraoperative Whitaker test was performed using a laparoscopic 22-gauge needle to puncture the renal pelvis and infuse saline at a rate of 10 mL/min. Bladder and renal pelvic pressures were measured simultaneously. After complete mobilization of the UPJ and crossing vessel, if present, the Whitaker test was repeated. Dismembered pyeloplasty was then performed.

RESULTS

Of the 10 patients, 6 had crossing vessels and 4 did not. The Whitaker test was successfully performed in all patients. Among those with a crossing vessel, all had a crossing artery, and 67% also had a crossing vein. No significant change was found in the renal pelvic pressure after mobilization of the renal pelvis in patients without crossing vessels. In those with crossing vessels, the mean renal pelvic pressure significantly declined after vessel repositioning (25.6 +/- 4.5 cm H2O to 9.5 +/- 6.6 cm H2O, P = 0.006).

CONCLUSIONS

In this pilot study, lower pole crossing vessels directly contributed to UPJ obstruction by causing extrinsic compression.

Laparoscopic transposition of lower pole vessels--the 'vascular hitch': an alternative to dismembered pyeloplasty for pelvi-ureteric junction obstruction in children

OBJECTIVE

Dismembered pyeloplasty is the traditional technique in the management of ureterovascular pelvi-ureteric junction obstruction (PUJO) in children. Controversy remains regarding the role of lower pole vessels as the sole aetiology for PUJO. Endopyelotomy and concomitant laparoscopic transposition of lower pole vessels for PUJO has been described in adults. We describe our technique of laparoscopic transposition of lower pole vessels in children with PUJO, leaving the PUJ intact.

PATIENTS AND METHODS

Thirteen patients (seven boys and six girls) with a mean age of 10.2 years (range 7-16 years) underwent laparoscopic transposition of lower pole vessels. Surgery was indicated on the basis of intermittent pain and ultrasound/MAG3 appearance of obstruction with or without reduced function. The technique involved laparoscopic transperitoneal mobilization of the lower pole vessels from the region of the PUJ thereby freeing the junction and transposing them superiorly onto the anterior wall of the pelvis. The main outcome measures were relief of pain and improvement in ultrasound appearance or drainage parameters on a postoperative MAG3 renogram performed within 4-6 weeks of surgery.

RESULTS

Median operating time was 92 min. All patients were discharged within 36 h of surgery. All patients remain pain free at a median of 6 months (range 3-18 months). Twelve patients showed good drainage on the postoperative MAG3 renogram and improvement in ultrasound appearance. One patient had recurrent symptoms requiring insertion of a JJ stent. She has undergone further laparoscopic exploration. The vessels were in their transposed position and there was a kink at the PUJ which was released. She had a vertical pyelotomy and transverse closure over the JJ stent with good results.

CONCLUSION

This technique is simple and requires less operating time. No anastomosis or temporary JJ stent is required. Our early results are very encouraging with no serious complications.

Acucise endopyelotomy: A technique with limited efficacy for primary ureteropelvic junction obstruction in adults

AIM

To retrospectively evaluate the ef fi cacy of Acucise endopyelotomy in a series of patients with primary ureteropelvic junction obstruction (UPJO).

METHODS

Twenty-four patients with a symptomatic primary UPJO underwent Acucise endopyelotomy. Patients with high-grade hydronephrosis and/or poor renal function were excluded. Patients were followed by ultrasound imaging, intravenous urography, diuretic renography, and clinical review.

RESULTS

The overall success rate was 58% (14/24 patients), with a median follow up of 32 months. Of the ten patients in whom Acucise endopyelotomy failed, seven underwent open pyeloplasty, one required nephrectomy, and two received a permanent ureteral stent. A poor outcome was noted in patients without perioperative extravasation.

CONCLUSIONS

Our experience with Acucise endopyelotomy indicates that the success rate is lower than initially reported. Larger studies are needed to clarify the role of Acucise endopyelotomy in comparison with other techniques.