Does the use of 5 mm instruments affect the outcomes of robot-assisted laparoscopic pyeloplasty in smaller working spaces? A comparative analysis of infants and older children

Minki Baek, Mesrur Selcuk Silay, Jason K. Au, Gene O. Huang, Rodolfo A. Elizondo, Kathleen T. Puttmann, Nicolette K. Janzen, Abhishek Seth, David R. Roth, Chester J. Koh

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Introduction: Pediatric robot-assisted laparoscopic (RAL) pyeloplasty has become a viable minimally invasive surgical option for ureteropelvic junction obstruction (UPJO) based on its efficacy and safety. However, RAL pyeloplasty in infants can be a challenging procedure because of the smaller working spaces. The use of the larger 8 mm instruments for these patients instead of the 5 mm instruments is common because of the shorter wrist lengths. Objective: We hypothesized that the use of 5 mm instruments for RAL pyeloplasty in infants with smaller working spaces will have comparable perioperative parameters and surgical outcomes in comparison with older children with larger working spaces. Study design: We compared the perioperative parameters and surgical outcomes of RAL pyeloplasties performed by a single surgeon in infants and non-infant pediatric patients over a 2 year period. All of the procedures were performed using an 8.5 mm camera and 5 mm robotic instruments. Patient demographics, operative times, perioperative complications, hospital pain medication usage, hospital length of stay, and treatment success rates were compared between the two groups. Results: A total of 65 pediatric RAL pyeloplasties were included in the study (16 infants and 49 non-infants, Table). There were no significant differences in gender, laterality, proportion of re-do pyeloplasty, or preoperative hydronephrosis grade between the two groups. All procedures were performed without conversion to open surgery or significant perioperative complications. There were no differences in segmental operative times (total operative time, console time, port placement time, time for dissection to UPJO, and anastomosis time), hospital pain medication usage, and hospital length of stay between the two groups (p > 0.05 for all comparisons). The treatment success rates were 93.8% (15/16) and 100% (49/49), respectively (p = 0.08). Discussion: We present the first comparative study of infant and non-infant pediatric RAL pyeloplasty using 5 mm robotic instruments. An advantage of the current study is the use of a single surgeon's experience to compare RAL pyeloplasty outcomes in infants with those of older children, a group in which RAL pyeloplasty has already been shown to be efficacious and safe. Operative tips for infant RAL pyeloplasty are also provided. Conclusions: RAL pyeloplasty is a safe and effective surgical modality even in infants, with comparable perioperative parameters and outcomes as those in older children. The use of 5 mm instruments in infants does not affect outcomes and offers the potential for improved cosmesis.

Original languageEnglish (US)
Pages (from-to)537.e1-537.e6
JournalJournal of Pediatric Urology
Issue number6
StatePublished - Dec 2018


  • Children
  • Hydronephrosis
  • Infant
  • Pyeloplasty
  • Robotics
  • Ureteropelvic junction obstruction

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Urology


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