PRENATAL ULTRASOUND HAS LED TO EARLIER DETECTION AND REPAIR OF URETEROPELVIC JUNCTION OBSTRUCTION

Robotic pyeloplasty learning curve for a pediatric surgeon without previous laparoscopic pyeloplasty experience

Robotic pyeloplasty has become a technique of choice for pyelo-ureteral junction syndrome treatment in children. Less invasive than open surgery, robotic pyeloplasty also has a lower learning curve than laparoscopic pyeloplasty. This is how a new generation of surgeons without previous laparoscopic pyeloplasty experience has begun training in robotics. To assess the robotic assisted pyeloplasty learning curve for a pediatric surgeon only trained in open pyeloplasty, and to investigate if that mode of practice is safe and effective. Data were collected from all children operated on for pyelo-ureteral junction syndrome by the same surgeon in our center between 2015 and 2021. Cases were divided into 4 groups of 14 consecutive procedures to analyze the learning curve. Fifty-six patients were operated on, with a median (IQR) age, weight, and hospital stay of 9 years and 1 month old (3.5), 29 kg (17.3), and 3 days (2), respectively. The mean ± SD operative times were 146.5 ± 39.3, 123.2 ± 48.1, 103.1 ± 29.5, and 141.7 ± 25.0 min, with a unique significant difference between groups 1 and 3 (p = 0.007**). Only two intraoperative and nine postoperative complications were observed. The surgery was successful in 98% cases. Our study shows that a significant improvement in surgical time could be achieved in the first 30 cases, safely and efficiently even without previous laparoscopic pyeloplasty experience.Level of evidence: III.

Sonographic follow-up after pyeloplasty: a large, retrospective cohort analysis

PURPOSE

Routine scintigraphy after surgery for uretero-pelvic junction obstruction (UPJO) is discouraged, making ultrasound the preferred option for follow up. Yet, interpretation of sonographic parameters is rarely straightforward.

METHODS

We reviewed 111 cases including 97 pyeloplasty (52 open, 45 laparoscopic) and 14 pyelopexy during a 7-year period. Pre- and postoperative pelvic antero-posterior diameter (APD), cortical thickness (CT) and pelvis/cortex ratio (PCR) was measured serially.

RESULTS

85% were free of symptoms by 1 year. Only 11% had complete resolution of hydronephrosis. Eleven (10.4%) needed a redo procedure. Mean reduction in APD was 32.6%, 45.8%, and 51.7% at 6 weeks, 3 and 6 months respectively. CT increased by an average 55.9%, 75.6% and 107.6% while PCR reduced by 6.9, 8.0 and 8.8 at given intervals. Comparison of open and laparoscopic procedures showed no significant difference. Review of failed pyeloplasty showed failure of reduction in APD (APD > 3 cm or < 25% reduction) and PCR (PCR > 4) as early indicators for failure.

CONCLUSION

Both APD and PCR are reliable indicators of success and failure following pyeloplasty while CT alone is not as useful. Laparoscopic procedures are non-inferior to standard open surgery.

Perinatal Management in a Pregnant Woman with Ureteropelvic Junction Obstruction: Case Report and Literature Review

Although giant hydronephrosis (GH) associated with ureteropelvic junction obstruction (UPJO) is extremely rarely detected in pregnant women, diagnostic methods, therapeutic approaches, and perinatal management have not been established. A 31-year-old Japanese primipara had a 15 cm × 12 cm multi-cystic mass in the right abdomen detected by transabdominal ultrasound at gestational week 26. Magnetic resonance imaging revealed that the mass was right renal GH. She underwent serial ultrasound-guided transretroperitoneal drainage as conservative treatment. She delivered vaginally at gestational week 36. Since she had flank pain and a documented non-functional right kidney, laparoscopic nephrectomy was conducted 22 months after delivery. UPJO with fewer smooth muscle cells and fibrosis was histologically diagnosed in the surgical specimen. Her postpartum and postoperative courses were uneventful for 10 months. We performed a literature review of diagnostic methods, clinical characteristics, and perinatal management in pregnant women with GH due to UPJO.

Functional Magnetic Resonance Urography in Ureteropelvic Junction Obstruction: Proposal for a Pediatric Quantitative Score

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is one of the most frequent causes of congenital hydronephrosis. It is essential to distinguish UPJO which needs surgical treatment. fMRU combines high quality morphological details of the kidney and excretory pathways with functional data.

OBJECTIVE

This study aims to introduce a new radiological score based on fMRU findings to be able to differentiate surgical from non-surgical kidneys.

MATERIALS AND METHODS

We retrospectively selected patients with hydronephrosis due to UPJO who underwent fMRU (January 2009-June 2018). A multidisciplinary team identified a list of fMRU morpho-functional predictive variables to be included in the analysis. To evaluate the role of different independent variables in predicting the outcome, a multivariable logistic regression model has been performed; the outcome variable was the surgical intervention. For each predictive variable, Odds Ratio and 95% Confidence Intervals were calculated. The likelihood ratio test was used to assess the significance of the variables. Using the regression model, we assigned a numerical value to each predictive variable, rounding up the beta-coefficients. The cut-off value of the total score was obtained from the ROC curve analysis.

RESULTS

A total of 192 patients were enrolled, corresponding to 200 pathological kidneys. All of them underwent fMRU; 135 were surgically treated, while 65 underwent ultrasound or MRU follow-up. Predictive variables significantly associated with surgery resulted to be the urographic phase, the presence of abnormal vessels, and a baseline anterior-posterior pelvic diameter >23 mm. Beta coefficients of the logistic regression model were then converted in scores. The ROC curve of the score showed high sensitivity (84.3%) and specificity (81.3%) with a cut-off > 2.5.

CONCLUSIONS

We propose a new fMRU score able to identify surgical vs. non-surgical kidneys with UPJO.

Surgical validation of functional magnetic resonance urography in the study of ureteropelvic junction obstruction in a pediatric cohort

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is one of the most common urological diseases in children. The etiology can be intrinsic, extrinsic (crossing vessel [CV] or adhesions), or mixed. To date, ultrasonography and scintigraphy are considered gold-standard imaging techniques for the study of UPJO. Functional magnetic resonance urography (fMRU) combines anatomical and functional information and has been recently evaluated for the detection of CVs in UPJO.

OBJECTIVE

The objective of the study was to evaluate the concordance between fMRU and surgery in determining the etiology of UPJO and the presence of obstructing/non-obstructing CVs.

STUDY DESIGN

Patients with unilateral hydronephrosis who underwent surgery after an fMRU were included in the sample. Surgical data regarding the etiology of UPJO were compared with radiological results. The etiology was divided into intrinsic, extrinsic due to CV, extrinsic due to adhesions, and mixed or cicatricial (postoperative). The concordance was calculated by means of the Cohen's kappa coefficient.

RESULTS

The observed agreement between fMRU and surgical findings regarding the etiology and the presence of CV were 83.2% and 89.4%, respectively (with substantial Cohen's kappa coefficient). The sensitivity and specificity of fMRU were 0.84 and 0.93, respectively; the positive predictive value (PPV) and negative predictive value (NPV) were 0.889 and 0.897, respectively. The observed agreement regarding the type of vessel was 88.3% with a Cohen's kappa coefficient of 0.787 (substantial).

DISCUSSION

In children with hydronephrosis, it is very important for the surgeon to quantify the extent of dilation, define the etiology of the obstruction, and the presence or absence of CVs. fMRU is a 'one-stop-shop' technique which provides both anatomical and functional information showing a high concordance with surgical findings, avoiding radiation exposure.

CONCLUSIONS

fMRU should be considered a valid imaging technique in the study of pediatric UPJO, as it provides the surgeon with important information regarding the etiology of the obstruction for the preoperative planning.

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.

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.

Is decreased diameter of renal pelvis in prone position an indicator of successful pyeloplasty?

OBJECTIVE

To evaluate patients who had undergone pyeloplasty for pelviureteric junction obstruction, by measuring the anteroposterior diameter (APD) of the renal pelvis in supine and prone positions, and determine whether a decrease in APD in prone position can exclude obstruction in dilated renal system.

MATERIALS AND METHODS

From January 2012 to December 2013, patients who had undergone pyeloplasty were evaluated by ultrasound in two centers. The difference of APD of the renal pelvis in supine and prone positions was obtained. Correlation was made with the pre- and post-pyeloplasty renal function by radionuclide renogram.

RESULTS

There were 42 patients (31 males, 11 females; age range 5 months to 18 years). Residual hydronephrosis was detected in 41 patients of whom 35 patients (85%) showed decrease in APD by >10% in prone position. These patients and the one without hydronephrosis showed either no deterioration or improvement in renal function. Six patients (15%) showed either no change or increase in APD in prone position. Three patients (7.5%) were confirmed to have decrease in renal function indicating obstruction. Three patients (7.5%) showed no deterioration of renal function, but sluggish drainage on radionuclide renogram.

CONCLUSION

Demonstration of decreased APD of renal pelvis in prone position by ultrasound is useful to differentiate obstructed from non-obstructed dilated renal system, and it correctly identified 85% candidates with successful pyeloplasty. In patients with no decrease or increase in APD at prone position, further follow-up is recommended to rule out obstruction.

Is urine intercellular adhesion molecule-1 a marker of renal disorder in children with ureteropelvic junction obstruction?

AIM

We aimed to investigate whether urine intercellular adhesion molecule-1 (ICAM-1) might serve as a marker of renal disorder in children with ureteropelvic junction obstruction.

MATERIAL AND METHODS

Twenty-nine children with severe hydronephrosis (HN) were compared with 23 participants with mild HN and with 19 healthy peers.

RESULTS

Urine ICAM-1/uCre levels were significantly higher in HN children than healthy controls (P<0.01), and in severe HN when compared with mild HN (p<0.05).

CONCLUSIONS

It seemed to us that uICAM-1 is a biomarker of renal disorder, and might have the potential to predict which patients will require surgery.

Laparoscopic pyeloplasty in infants: single-surgeon experience

INTRODUCTION

Although laparoscopic pyeloplasty (LP) is popular in children, its role in infants is less well defined. It is presumed that infant LP is technically challenging, with a higher failure rate.

OBJECTIVE

To consider the hypothesis that LP can be safely and successfully performed in infants.

METHODS

The records of 111 infants that underwent LP from March 2009 to December 2013 with at least 1 year of follow-up, were retrospectively reviewed. The results of pre- and postoperative imaging studies (ultrasound (US) and diuretic renogram (DR)), operative details and complications were noted. Pre- and postoperative parameters were compared using statistical software.

RESULTS

The details are given in the Table. Laparoscopic pyleoplasty was successfully completed using three ports in all children without any open conversions. There were complications in 14 children (12%); 13 did not require a second intervention and the final outcome was not affected. One child (1%) had a re-obstruction with worsening hydronephrosis (HDN) 2 months after stent removal; she underwent successful redo LP. Median follow-up was 2 years; LP was successful in relieving the obstruction in 115 kidneys (99%); all had follow-up US, while 76 children had follow-up DR. The tests showed significant reduction in HDN (mean pre-operative anteroposterior diameter (APD) of renal pelvis, 34.4 mm (SD 13.4) versus mean post-operative APD 10.6 mm (SD 5.7), p < 0.001) and improved drainage in all kidneys. In unilateral cases, there was significant improvement in mean split renal function (SRF) of the operated kidneys (pre-operative 22.1% (SD 8.6) versus post-operative 35.6% (SD 11.4), p < 0.001).

DISCUSSION

Over the past 6 years, all pyeloplasties at our unit have been performed by laparoscopy, irrespective of the age or weight of the child. In this large retrospective series, it is demonstrated that infant LP is a safe and successful operation; pyeloplasty in this age group not only resulted in significant reduction of hydronephrosis, but also in significant functional improvement. The results are comparable to published series comparing open pyeloplasty to laparoscopic and robotic-assisted laparoscopic pyeloplasty, which report success rates ranging from 70 to 96%, and complication rates ranging from 0 to 24% for open pyeloplasty.

Failed pyeloplasty in children: revisiting the unknown

OBJECTIVE

To perform a critical analysis of the management of the pediatric failed pyeloplasty in a large tertiary center. The ideal approach to this rare entity is not well established.

METHODS

Retrospective record review of children undergoing pyeloplasty from 2000 to 2010. All cases that required any type of reintervention, excluding stent removal, were analyzed. Data collected included: demographics, indication for and modality of the initial surgery, presence of crossing vessels, mode of diagnosis of failure, and type(s) of reintervention with the correspondent success rate(s).

RESULTS

Overall, pyeloplasty failure rate was 27 per 455 patients (5.9%). Age, initial indication for pyeloplasty, and modality of surgery (open vs laparoscopic) yielded similar failure rates. Indications for reintervention were as follows: worsening asymptomatic hydronephrosis 16 of 27 (59%), pain 7 of 27 (26%), urosepsis 2 of 27 (7.5%), and others 2 of 27 (7.5%). Eight of 27 (30%) improved with 1, 14 of 27 (52%) had 2, and 5 of 27 (18%) required 3 reinterventions, respectively. Mean interval between the first operation and subsequent interventions was 19.3, 24.9, and 27 months for the first, second, and third reinterventions, respectively. Modalities of reintervention with respective success rates were as follows: double J stent insertion 16% (6%), endopyelotomy 18% (50%), redo pyeloplasty 12% (92%), and ureterocalicostomy 4% (100%). Only 1 patient (7%) was documented to have a missed crossing vessel. All patients were stable and doing well after a mean follow-up of 56 months after the first operation.

CONCLUSION

According to this series, more invasive and definitive techniques, such as redo pyeloplasty and ureterocalicostomy, are more successful than minimally invasive ones to treat failed pyeloplasty and should probably be offered sooner rather than later.

Early postoperative ultrasound after open pyeloplasty in children with prenatal hydronephrosis helps identify low risk of recurrent obstruction

PURPOSE

Prediction of successful pyeloplasty can be challenging, particularly in asymptomatic children treated for worsening prenatally diagnosed hydronephrosis. We evaluated early noninvasive objective predictors of success in this population.

MATERIALS AND METHODS

We reviewed patients who underwent pyeloplasty for asymptomatic, prenatally detected, worsening hydronephrosis treated between 2000 and 2010 with followup greater than 1 year. For all patients renal pelvis anteroposterior diameter in a mid transverse view and Society for Fetal Urology hydronephrosis grade were evaluated preoperatively and 3 to 4 months postoperatively. Aside from subjective evaluation based on change in hydronephrosis grade, we estimated the percentage of improvement in anteroposterior diameter (preoperative diameter--postoperative diameter/preoperative diameter). Repeat intervention after pyeloplasty arbitrarily defined failure. Patients were categorized into 3 groups, ie no failure on followup ultrasound (group 1), no failure with postoperative nuclear scan to document success (group 2) and failed pyeloplasty (group 3). ROC curves were plotted to correlate 4 variables with failure, namely preoperative anteroposterior diameter, postoperative anteroposterior diameter, percent improvement in anteroposterior diameter and subjective change in grade.

RESULTS

Of 229 patients 192 (84%) who met inclusion criteria had ultrasound at 3 to 4 months postoperatively available. Mean age at surgery was 19 months and mean ± SD followup was 49.9 ± 27.7 months. Percent improvement in anteroposterior diameter and postoperative anteroposterior diameter measure were the most reliable variables to predict failure (AUC 0.88 and 0.86, respectively, p <0.0001), whereas preoperative anteroposterior diameter and subjective changes in grade were not good predictors (AUC 0.52, p >0.05). A percent improvement in anteroposterior diameter of 38% or greater or postoperative anteroposterior diameter of 11.5 mm or less was associated with success, with sensitivity of 100% and specificity of 61% and 55%, respectively.

CONCLUSIONS

Percent improvement in anteroposterior diameter and postoperative pelvic anteroposterior diameter measure can provide objective guidance as to which patients need closer monitoring during followup, and can help select children at low risk for repeat intervention after pyeloplasty.

Prenatal diagnosis: what do we know of long-term outcomes?

Although prenatal diagnosis has been a prominent feature of Paediatric Urology for more than two decades the published literature has been largely characterized by studies reporting short to medium-term follow up. This deficiency is now being addressed by the growing availability of published and unpublished long-term outcome data for a range of prenatally detected anomalies. This review analyses the evidence on long-term outcomes which is provided by studies with mean or median follow- up exceeding 5 years, with particular emphasis on the small number of studies reporting follow -up at 10 years and beyond. The natural history and outcome of conservatively managed uropathies is considered in conjunction with an appraisal of evidence- based indications for surgical intervention. This review evaluates the relative benefits and drawbacks of prenatal diagnosis for children and their parents and also considers the impact of prenatal diagnosis on the delivery of Paediatric Urological services and specialist training.

[Postnatally hydronephrosis (HN) in children with antenatally diagnosed hydronephrosis: surgery or medical treatment?]

OBJECTIVES

There is no formal agreement or criteria utilized to establish a standard of treatment in children with antenatally diagnosed HN.

METHODS

We analyzed our own experience in addition to the protocols attending to this subject. Twenty eight (28) children with unilateral HN were assessed from October 1999 through October 2005 and the anteroposterior diameter of renal pelvis (APDP) was measured.

RESULTS

Patients underwent surveillance with US and cintilography in 3, 6, 12 and 24 months. The treatment results were reviewed following the classification of Society of Fetal Urology: slight (2 to 5 mm), moderate (6 to 10 mm) and severe (> 10-15 mm).

CONCLUSIONS

We concluded that slight HN would never be operated on while the severe ones would always be. The moderate HN, on the other hand, would remain under surveillance with US and cintilography for two years.

Rapid onset renal deterioration in an adult with silent ureteropelvic junction obstruction

We report a case of a rapid renal deterioration due to ureteropelvic junction obstruction (UPJO) in an asymptomatic woman with prior normal diuretic renography. This case illustrates “silent” renal obstruction and the inability of diuretic renography in detecting significant renal obstruction. This case may favor close surveillance of any adult patient with potential UPJO, especially those with underlying renal disease or solitary kidney.

Ureteropelvic Junction Obstruction

PURPOSE

We quantified the burden of ureteropelvic junction obstruction in the United States by identifying trends in the use of health care resources and estimating the economic impact of the disease.

MATERIALS AND METHODS

The analytical methods used to generate these results were described previously.

RESULTS

Inpatient hospitalization rates were highest in children younger than 3 years. Most patients were male and hospitalizations occurred almost exclusively at urban centers. Patients with a primary diagnosis of ureteropelvic junction obstruction between 1994 and 2000 had an overall decrease in the age adjusted rate of inpatient hospitalization from 1.1/100,000 to 0.8/100,000. Physician office visits by Medicare beneficiaries with ureteropelvic junction obstruction as the primary diagnosis showed stable overall age adjusted rates during the reported years. Between 1999 and 2003 mean inpatient length of stay and cost per child hospitalized with the primary diagnosis of ureteropelvic junction obstruction was 2.9 days and $7,728, respectively. Average length of stay decreased more for children than for adults but total inpatient spending remained stable at about $12 million.

CONCLUSIONS

The majority of ureteropelvic junction obstructions are diagnosed in the perinatal period. Surgical intervention for pediatric patients has decreased with time, while there has been an increasing trend toward the conservative management of this condition.

Antegrade percutaneous endopyelotomy

Ureteropelvic junction obstruction (UPJO) is a well-known pathologic condition with several potential associated urologic complications. The treatment for UPJO has evolved dramatically during the past two decades with the advent of minimally invasive treatment options. This has resulted in shorter hospital stays, reduced postoperative pain, and quicker convalescence compared with the gold standard, open pyeloplasty. Antegrade (percutaneous) endopyelotomy is one of the many minimally invasive treatment options for this disorder. In this article, we review the technical aspects, outcomes, and current role of antegrade endopyelotomy in the treatment of UPJO.

Is it always necessary to treat a ureteropelvic junction syndrome?

The term ureteropelvic junction (UPJ) obstruction covers different morbid entities, and the old aphorism, "A UPJ is not a UPJ" remains true. Hydronephrosis is readily seen on antenatal ultrasonography but does not necessarily imply obstruction. Although most cases will resolve spontaneously, the probability of a significant pathology is related to the degree of pyelectasis, as seen on the third trimester study. Criteria of obstruction are difficult to define with precision, but two that are well-accepted are size of the renal pelvis (> 15 mm) and relative renal function, as determined by adequate isotopic studies. A new therapeutic standard has been established, and minimally invasive surgery has finally dethroned its open rival. Possibly facilitated by robotic assistance, laparoscopic dismembered pyeloplasty is the present gold standard, albeit endopyelotomy remains the least invasive with similar results in carefully selected patients.