Pyeloplasty is a safe and effective surgical approach for low functioning kidneys with ureteropelvic junction obstruction

Pediatric Robot-Assisted Laparoscopic Pyeloplasty: Where Are We Now?

PURPOSE OF REVIEW

This review aims to provide an in-depth exploration of the recent advancements in robot-assisted laparoscopic pyeloplasty (RALP) and its evolving landscape in the context of infant pyeloplasty, complex genitourinary (GU) anatomy, recurrent ureteropelvic junction (UPJ) obstruction, cost considerations, and the learning curve.

RECENT FINDINGS

Recent literature highlights the safety and efficacy of RALP in treating the infant population, patients with complex GU anomalies, and recurrent UPJO which were all traditionally managed using the open approach. Cost considerations are evolving, with the potential for RALP to have a lesser financial burden. In addition, the learning curve for RALP is diminishing due to robust training programs and advances in research. RALP has become the gold standard in the treatment of UPJO in pediatric urology at many children's hospitals. Surgeon comfort and research in this space allow safe and successful reconstruction in the most challenging of cases.

Results of Temporary Drainage of Poorly Functioning Kidneys With Ureteropelvic Junction Obstruction: Does the Histology of Persistent Poor Functioning Kidneys Indicate an Increased Risk of Hypertension?

OBJECTIVE

To review our experience with managing poorly functioning kidneys with ureteropelvic junction obstruction (PFK-UPJO) with differential renal function (DRF) <10% by a trial of temporary drainage, as the management of such kidneys is controversial. We also studied the histopathologic changes in the nephrectomy specimens of persistent PFK-UPJO, as tubulointerstitial damage may predispose to hypertension.

METHODS

A retrospective review of cases undergoing treatment for unilateral UPJO over 5-year period in 2 centers was conducted. In PFK-UPJO, 4-6 weeks trial of drainage with double J stent or percutaneous nephrostomy was employed. Those kidneys that improved DRF to >10% underwent pyeloplasty, while persistent PFK underwent nephrectomy; the specimens were studied for interstitial fibrosis/tubular atrophy (IF/TA), arterial lesions, and arteriole lesions.

RESULTS

Of 402 patients with unilateral UPJO that underwent surgical management, 17 (4.1%) had PFK-UPJO. After 4-6 weeks trial of drainage, 6 kidneys (35.2%) with improved DRF underwent pyeloplasty, while 11 kidneys with persistent PFK underwent nephrectomy; significant IF/TA, arterial, and arteriolar changes were noted in 9 (82%), 9 (82%), and 4 (36%) kidneys, respectively, including 7 kidneys in normotensive children. Two (11.7%) children had hypertension at presentation; 1 child remains hypertensive even after nephrectomy.

CONCLUSION

In PFK-UPJO, trial of temporary drainage seems appropriate to decide plan of management; 35% of such kidneys improved function after drainage. Most persistent PFK demonstrated severe and irreversible histologic changes that may predispose to hypertension if they are preserved, and we suggest that such kidneys may be removed. Long-term follow-up of all preserved PFK-UPJO is strongly recommended.

Laparoscopic assisted dismembered pyeloplasty versus open pyeloplasty in UPJO with poorly function kidney in pediatrics

BACKGROUND

The management of UPJO with poor function kidney, less than 10%, has been the subject of debate for more than a decade. Some authors have recommended nephrectomy, while others favor renal salvage (pyeloplasty). We report our experience with laparoscopic assisted pyeloplasty in pediatric patients with poorly functioning kidneys in comparison with an open approach.

MATERIALS AND METHODS

A retrospective study was conducted to review 65 patients who were diagnosed with hydronephrosis and had impaired renal function due to UPJO. The study was conducted in the pediatric surgery departments of Al-Azhar University Hospital and Fattouma Bourguiba University Hospital of Monastir over a period of 20 years. Limited to pediatric patients with UPJO with ≥ Grade III hydronephrosis, antero-posterior pelvic diameter ≥ 20 mm, as well as a renal function equal to or less than 10%, was corrected by laparoscopic assisted or open pyeloplasty.

RESULTS

There were 40 cases in group A who underwent laparoscopic assisted pyeloplasty, and 25 cases in group B who underwent open pyeloplasty. There were no complications or difficulties during the operation. The mean operative time in group A was 90 ± 12 min, while in group B, it was 120 ± 11 min. The renal assessment parameters significantly improved in both groups. In group A, the mean split renal function was 7.9 ± 1.3% and increased to 22.2 ± 6.3%. In group B, the mean split renal function was 8.1 ± 1.1% and increased to 24.2 ± 5.1%. However, the differences between both groups in terms of pre-operative and post-operative renal functions were statistically insignificant.

CONCLUSION

Laparoscopic assisted pyeloplasty is an effective treatment for patients with poorly functioning kidneys, especially those with less than 10% function. While this surgical procedure requires shorter operative times, it yields functional outcomes that are comparable to open approach.

Functional recoverability post-pyeloplasty in children with ureteropelvic junction obstruction and poorly functioning kidneys: Systematic review

BACKGROUND

The management of poorly functioning kidneys (PFK) associated with ureteropelvic junction obstruction (UPJO) is controversial. There is contradictory information about how to best manage these cases: pyeloplasty or nephrectomy?

OBJECTIVE

To systematically summarize the available evidence concerning the effects of pyeloplasty on the differential renal function of PFK in children with unilateral UPJO, highlighting the ongoing challenges in their definition, management, and long-term follow-up. In addition, we aim to verify potential predictors of renal functional recoverability that could help clinicians choose candidates for pyeloplasty.

METHODS

We searched several databases including PubMed, Embase, and Cochrane Library CENTRAL until August 20, 2021, according to the PRISMA guidelines. The following concepts were searched: pediatric, ureteropelvic junction obstruction, UPJO, pyeloplasty, recovery, split renal function, and differential renal function. We enrolled studies where the PFK was defined as preoperative differential renal function (DRF) ≤30% by renal scintigraphy. Potential predictors of renal functional recoverability were assessed and compared among studies. The quality of the included studies was evaluated using a modified version of the Newcastle-Ottawa scale (NOS).

RESULTS

1499 citations perceived as relevant to screening were retrieved. After screening, 20 studies were included, comprising a total of 625 cases. The number of patients in each study varied between 5 and 84, while the average post-surgical follow-up duration ranged between 3 months and 180 months. The most significant preoperative predictive factor for postoperative functional recoverability was the baseline DRF, especially when antenatally diagnosed. The quality was considered average in a significant portion of included studies.

CONCLUSION

A significant proportion of PFK showed an increase of DRF post-pyeloplasty. However, no consistent predictive factors for functional recoverability have yet been determined apart from preoperative DRF. Until further evidence appears, pyeloplasty should be considered a valid option in the armamentarium of UPJO management in PFK.

Factors predicting improvement of differential renal function after pyeloplasty in children of ureteropelvic junction obstruction

INTRODUCTION

To evaluate differential renal function (DRF) in unilateral ureteropelvic junction obstruction (UPJO) patients under 18 years old after pyeloplasty and to identify factors predicting postoperative improvement.

MATERIAL AND METHODS

A total of 95 patients with unilateral UPJO treated by pyeloplasty between March 2019 to March 2020 were prospective enrolled. All patients had preoperative dynamic renal scintigraphy and were required to review after surgery 6 months. We defined DRF improvement as postoperative DRF increased ≥5% (If preoperative DRF less than 55%) or postoperative DRF reduced ≥5% and reached a normal range (45-55%) (preoperative DRF more than 55%) with drainage improvement. Drainage improvement indications were defined as a resolution of symptoms; decrease in hydronephrosis without requiring additional procedures and T_1/2＜20min in dynamic renal scintigraphy. All parameters were statistically compared.

RESULTS

In the study, 28 (29.5%) patients showed improvement in postoperative DRF, and 67 (70.5%) patients maintained stable postoperative DRF. Gender, age, baseline DRF, anteroposterior pelvic diameters (APD), minimum and maximum renal parenchymal thickness (PT), and anterior-posterior diameter/maximum renal parenchymal thickness (APD/PT) were correlated with postoperative DRF improvement in univariable analysis. In the multivariable analyses, maximum PT and APD/PT were predictors of improvement in postoperative DRF.

DISCUSSION

In our study, the maximum PT was associated with the improvement of renal function in patients with UPJO, and when the thickest part of the renal parenchyma was measured, APD/PT can predict the improvement of renal function. We infer that the compression of the thickest part of the renal parenchyma may be the reason for the impaired renal function in some patients, and when the obstruction was relieved, the compressed parenchyma function can be significantly improved.

CONCLUSIONS

Postoperative DRF of UPJO patients can be effectively improved and preserved through pyeloplasty. Maximum PT and APD/PT can predict improvement of renal function in patients with UPJO after pyeloplasty.