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Updated: Jan 2, 2026
Robot-Assisted Kidney Transplantation
Published on: July 19, 2021
Does the body weight influence the outcome in children treated with robotic pyeloplasty?
Lorenzo Masieri1, Simone Sforza1, Antonio Andrea Grosso1
1Department of Pediatric Urology, University of Florence, Meyer Hospital, Florence, Italy; Department of Oncologic, Minimally-Invasive Urology and Andrology, Careggi Hospital, University of Florence, Italy.
Insights
Robot-assisted laparoscopic pyeloplasty (RALP) is effective for treating uretero-pelvic junction obstruction (UPJO) in children under 15 kg, showing outcomes comparable to heavier patients. This minimally invasive approach offers favorable results for younger, lower-weight children.
Area of Science:
- Pediatric Urology
- Minimally Invasive Surgery
- Robotic Surgery
Background:
- Uretero-pelvic junction obstruction (UPJO) is a common congenital anomaly in children.
- Robot-assisted laparoscopic pyeloplasty (RALP) is increasingly used for UPJO treatment.
- The influence of body weight on RALP outcomes in pediatric patients is not well-established.
Purpose of the Study:
- To evaluate the peri-operative and long-term outcomes of RALP in pediatric patients with UPJO.
- To compare outcomes between children weighing less than 15 kg and those weighing 15 kg or more.
Main Methods:
- Retrospective analysis of 61 consecutive pediatric patients undergoing RALP for UPJO.
- Patients were divided into two groups: Group A (< 15 kg) and Group B (≥ 15 kg).
- Surgical success was defined by imaging and symptom resolution; all procedures by a single surgeon.
Main Results:
- No significant differences in operative time, hospital stay, or catheterization duration between groups.
- Similar success rates (94.4% vs 97.7%) and complication rates (Clavien 2-3b) were observed.
- Relapse occurred in one child per group, both requiring nephrostomy placement.
Conclusions:
- RALP is a feasible and effective treatment for UPJO in children under 15 kg.
- Outcomes in lower-weight children are comparable to those in heavier counterparts.
- The technique is safe and effective, even with potential challenges of smaller anatomy.
Introduction:
To investigate the influence of the body weight on peri- and postoperative outcome in a series of pediatric patients with a diagnosis of uretero-pelvic junction obstruction (UPJO) treated with robot-assisted laparoscopic pyeloplasty (RALP) at a single tertiary referral center.
Objective:
In this study, outcomes of RALP in children divided according to the weight are evaluated.
Study Design:
Sixty-one consecutive patients treated with RALP from January 2016 to May 2019 were recorded retrospectively and divided according to their weight: group A < 15 kg, group B ≥ 15 kg and were included in this study. Eligible criteria for surgery were symptomatic UPJO, worsening of hydronephrosis, or obstructive pattern at renogram. Success criteria were the reduction of the hydronephrosis at imaging and the absence of flank pain. All procedures were performed by one expert robotic surgeon.
Results:
18 patients were included in group A (median weight 12 kg) and 43 patients in group B (median weight 33 kg). The median (IQR) operative was 95 (90-120) for group A compared to 90 (85-110) of control group. No significant difference has been found (P = 0.93). We registered one (5.6%) Clavien 3b complication (omental hernia after removal of the drainage requiring surgical correction) and two (4.7%) Clavien 2 complication in group B (urinary infections). No difference has been found in the length of hospital stay, length of catheterization, and duration of procedure between the groups (P > 0.05). At a median follow-up of 23 months (IQR 9-27 vs 9-33), the success rate was comparable between the two groups (94.4% vs 97.7%; P = 0.51). Relapse was recorded in one child per group and both required nephrostomy placement.
Discussion:
Our study tried to fill the gaps in the evidence on the feasibility of RALP in low-weight children reporting favorable peri-operative and long-term outcomes; however, this study shows some intrinsic limitations. The relatively small numbers of patients in the <15 kg may have underpowered the comparison with heavier patients. Moreover, only two patients were <10 kg so that no definitive conclusions on the safety and feasibility of RALP in this cohort of patients can be drawn.
Conclusion:
RALP in children <15 kg was feasible and effective to treat UPJO with superimposable results to heavier counterparts. In our experience, the need for a different trocar placement and limited space in patients <15 kg did not affect peri-operative and functional outcomes.
