Figure 1. Four-month-old male and 8.5 kg. Incisions after robot assisted pyeloplasty. Distance between ports was 4 cm. Procedure performed with Da Vinci XI system.

The gold-standard for the treatment of ureteropelvic junction obstruction in the pediatric population has historically been the Anderson-Hynes dismembered open pyeloplasty described in 1949.¹ However, there has been technological advantages with minimally invasive surgery in recent years, both in laparoscopy and robotic-assisted surgery, allowing these approaches to be comparable in efficiency and safety when compared to the gold standard. Advantages of minimally invasive surgery over open surgery in reducing postoperative pain and hospital stay in many cases, and improving aesthetic results as well, have been reported.²

Figure 2. Comparison of average surgery time (A), average postsurgery hospital length of stay (B), and average post-op max pain score 24-48 hours (C) between open pyeloplasty and robot-assisted pyeloplasty.

The first laparoscopic pyeloplasty in pediatrics was described in 1995 by Peters et al.³ It has been confirmed as a safe and effective procedure, but surgically demanding due to the requirement of intracorporeal suturing, reduced intraperitoneal space (1 liter), surgeon ergonomics, and a steep learning surgical curve.⁴ It was not until the DaVinci robotic surgery system was launched on the market in 2002 that the surgical technique of robot-assisted pyeloplasty began to be widely used, with the first series of cases described in 2006 by Lee et al.⁵ Since, it has become the most common urological robot-assisted surgical procedure in the pediatric population, with a very high success rate (95%-100%).^4,6,7 Initially this procedure had been recommended for patients older than 18-24 months and more than 10 kg due to its limited intraperitoneal space.⁸ However, thanks to an increase in robotic surgical expertise some authors have suggested this surgery could be performed safely in younger children.⁹ Some authors have performed a robotic approach in patients as young as 3 months old, but a minimum age limit has not been defined.¹⁰

Figure 3. Comparison of average surgery prep time between open pyeloplasty and robot-assisted pyeloplasty.

In order to define in which infants this approach is feasible, Finkelstein et al,² in a very interesting publication, reviewed 45 infants between 3 to 12 months old that underwent robot-assisted interventions, either for upper or lower urinary tract pathology. Their work consisted in measuring the distance between the anterior superior iliac spines (ASIS), and the puboxyphoid distance (PXD) in the preoperative assessment. Subsequently, recording the number of robotic arms collisions during the surgery was registered. They found that there were fewer collisions in patients with an ASIS distance greater than 13 cm (P < .001) and a PXD distance greater than 15 cm (P < .001; Figure 1) Dr Peters considers it critically important to have a constant mental image of the instrument dynamics within the body as well as outside to properly perform the procedure,⁹ and so the ASIS and PXD measures are a useful guide that can help define the feasibility of the approach.

More precise movements in small working spaces, surgical field magnification, reduction of tremor, and three-dimensional optics are the classic arguments reported by most surgeons that support robot-assisted surgery.¹¹ It is the authors’ opinion that robot-assisted surgery’s advantage in infants is the ability to perform a reconstructive procedure in situ. The ability to perform the anastomosis without distorting the anatomy that is otherwise required when the pelvis and ureter have to be externalized during open surgery avoids leaving the anastomosis at a nondependent location and it reduces the chances of missing a crossing vessel (although rare, we have seen infant cases due to crossing vessels) and malrotated kidneys to leave the anastomosis in a location that will continue to be compressed. Based on our experience with inanimate models, we have been able to improve the efficiency in small robotic cases without compromising the efficiency and safety during these procedures. Lombardo et al¹² shared their results of 44 patients under 1 year who underwent robotic pyeloplasty between 2010 and 2021. Their success rate was 100% at 19 months of follow-up with postoperative complications in 7 patients (15.6%), mainly urinary tract infections. Interestingly, the advantages of this technology seem to stand out compared to an open approach in challenging reconstruction cases with complex anatomy, such as duplex collecting systems, redo cases, ectopic kidneys, horseshoe kidneys, renal malrotation, and long ureteral strictures.¹³ In our experience, we have a cohort of 48 robot-assisted pyeloplasties compared to open pyeloplasties. Demographics are described in Table 1. In our cohort, operative times did not show a statistical difference between the two arms (Figure 2, A). A similar trend was seen for length of stay and pain scores (Figure 2, B and C). One interesting area our group has been working on is improving nonoperative times to reduce costs and improve efficiency. Our protocol for robot-assisted surgery demonstrated shorter in-room times by reducing the nonoperative time (Figure 3). This can be the way to reduce the known high costs of robot-assisted surgery along with other measures.

However, this ever-growing technology presents some potential drawbacks associated with higher costs to the health system related to equipment, its maintenance, and materials.^12,14,15 It is also important to note that the robot is not available in all pediatric centers and, unfortunately, not all pediatric urologists are trained in robotic surgery, especially in developing countries. Pediatric urology fellowship programs should develop standardized robotics training curricula or protocols.¹³ The surgical competence in robotic-assisted pyeloplasty has not yet been defined. In adults, robotic pyeloplasty requires an average of 77 cases to acquire the learning curve.¹⁶ Currently, in most training hospitals, the acquisition of robotic skills depends mainly on the availability of an experienced surgeon to act as a mentor to properly guide the trainee until he becomes competent.¹³ Evidence has shown that the learning curve in robotic surgery is shorter compared to laparoscopy. A study by Liu et al¹⁷ indicated that at least 18 cases were required to achieve proficiency in laparoscopic pyeloplasty, compared with 13 cases for the robotic approach. Other authors have suggested that experienced surgeons should perform at least 25-50 robotic-assisted pyeloplasties in young children or adolescents before performing this procedure in an infant.¹⁸

Almost a decade has passed since the introduction of robotic-assisted pyeloplasty in infants. This procedure has proven to be a feasible and safe procedure with a similar success rate to open pyeloplasty and has been rapidly adopted by many pediatric urologists around the world to treat upper tract congenital malformations in infants due to its advantages with visualization and magnification of the surgical field and tissue manipulation. Although the question of whether robotic pyeloplasty is the new gold standard in infants will remain for now, it is clear that the better role of robotic-assisted surgery extends to cases where open and laparoscopic approaches have met their limitations in complex reconstructive cases.