Response to commentary to "Prospective multicenter study on robot-assisted laparoscopic extravesical ureteral reimplantation (RALUR-EV): Outcomes and complications"

Paediatric robotic surgery: a narrative review

The benefits of minimally invasive surgery (MIS) compared with traditional open surgery, including reduced postoperative pain and a reduced length of stay, are well recognised. A significant barrier for MIS in paediatric populations has been the technical challenge posed by laparoscopic surgery in small working spaces, where rigid instruments and restrictive working angles act as barriers to safe dissection. Thus, open surgery remains commonplace in paediatrics, particularly for complex major surgery and for surgical oncology. Robotic surgical platforms have been designed to overcome the limitations of laparoscopic surgery by offering a stable 3-dimensional view, improved ergonomics and greater range of motion. Such advantages may be particularly beneficial in paediatric surgery by empowering the surgeon to perform MIS in the smaller working spaces found in children, particularly in cases that may demand intracorporeal suturing and anastomosis. However, some reservations have been raised regarding the utilisation of robotic platforms in children, including elevated cost, an increased operative time and a lack of dedicated paediatric equipment. This article aims to review the current role of robotics within the field of paediatric surgery.

Incidence and resolution of de novo hydronephrosis after pediatric robot-assisted laparoscopic extravesical ureteral reimplantation for primary vesicoureteral reflux

INTRODUCTION

With the advent of robot-assisted laparoscopic ureteral reimplantation (RALUR) for primary vesicoureteral reflux (VUR), understanding and minimizing its complications continues to be critical. Incidence of de novo hydronephrosis after RALUR could be indicative of an outcome that needs further study or could be a benign transient finding.

OBJECTIVE

In the present study, we hypothesized that the incidence of de novo hydronephrosis after RALUR is low and resolves spontaneously.

METHODS

An IRB-approved prospective single-institutional registry was utilized to identify all patients undergoing RALUR via an extravesical approach from 2012 to 2020. Patients with primary VUR and minimal (Grade I SFU) or no hydronephrosis prior to surgery were included. Patients who had other associated pathology or underwent concomitant procedures were excluded. Preoperative characteristics including VUR and hydronephrosis grades as well as post-operative clinical details and hydronephrosis grades were aggregated and analyzed.

RESULTS

86/172 (50%) patients (133 ureters), with median reflux grade of 3 (IQR: G2, G3) met the inclusion criteria. Patients underwent RALUR at a median age of 5.7 years (IQR: 3.4, 8.7) with median 36.2 months (IQR: 19.6, 63.6) follow-up. Renal ultrasound at 4-6 weeks post-op showed de novo hydronephrosis in 18 (13.5%) ureters; the complete resolution was seen in 13 ureters (72%) at a median of 4.5 months from surgery. Among the 5 with non-resolved hydronephrosis (SFU G2:4, G3:1), 2 patients (3 ureters) underwent subsequent interventions.

DISCUSSION

The present study evaluating the natural history of de novo hydronephrosis after RALUR-EV performed for primary VUR, is to our knowledge the largest cohort of patients undergoing RALUR that this has been studied in. In our cohort, the incidence of de novo hydronephrosis after RALUR was 13.5%, similar to rates reported in two OUR cohorts, and significantly lower than reported incidence rates of 22-26% in several OUR cohorts, and 30% in a RALUR cohort. In the present cohort, hydronephrosis resolved spontaneously in more than 72% of cases. The median time from surgery until resolution of hydronephrosis was 4.5 (1.6, 10.5) months, which is shorter in comparison to the average time to resolution of 7.6 months, reported by Kim et al. in an earlier study.

CONCLUSIONS

De novo hydronephrosis after RALUR can be followed with serial renal ultrasounds. The majority of de novo hydronephrosis post-RALUR is transient and resolves spontaneously within a year of surgery with a very low re-intervention rate.

The Role of the Versius Surgical Robotic System in the Paediatric Population

The uptake of robot-assisted surgery has continuously grown since its advent in the 1990s. While robot-assisted surgery is well-established in adult surgery, the rate of uptake in paediatric surgical centres has been slower. The advantages of a robot-assisted system, such as improved visibility, dexterity, and ergonomics, could make it a superior choice over the traditional laparoscopic approach. However, its implementation in the paediatric surgery arena has been limited primarily due to the unavailability of appropriately sized instruments as per paediatric body habitus, therefore, requiring more technologically advanced systems. The Versius surgical robotic system is a new modular platform that offers several benefits such as articulated instruments which pass through conventional 5 mm ports, compact arms for easier manoeuvrability and patient access, the ability to mimic conventional port placements, and adaptive machine learning concepts. Prior to its introduction to paediatric surgery, it needs to go through a careful pre-clinical and clinical research program.

Development and Validation of a Scoring System for Assessment of Clinical Failure after Pediatric Robot-Assisted Laparoscopic Extravesical Ureteral Reimplantation: A Multi-Center Study

We aimed to develop and validate a scoring system as an objective assessment tool for predicting clinical failure after pediatric robotic extravesical ureteral reimplantation. Data for this multi-institutional retrospective cohort was obtained from two tertiary referral hospitals. We defined clinical failure as incomplete radiographic resolution or post-operative febrile UTI. Patients were stratified into low, intermediate, and high-risk groups according to the score. External validation was performed using the model projected to the external validation cohort. An amount of 115 renal units in the development cohort and 46 renal units in the validation cohort were analyzed. The prediction score was calculated with weighted points to each variable according to their regression coefficient as age (year) + BMI + BBD times 10 + VUR grade times 7 + console time (h) + hospital stay times 6. The C-index of our scoring system was 0.850 and 0.770 in the development and validation cohorts, respectively. Clinical failure was significantly different among risk groups: 0% (low-risk), 3.3% (intermediate-risk), and 22.2% (high-risk) (p = 0.004) in the development cohort. A novel scoring system using multiple pre- and intra-operative variables provides a prediction of children at risk of failure after robotic extravesical ureteral reimplantation.

Preoperative Bladder Bowel Dysfunction Is the Most Important Predictive Factor for Postoperative Urinary Retention After Robot-Assisted Laparoscopic Ureteral Reimplantation via An Extravesical Approach: A Multi-Center Study

Introduction: Postoperative acute urinary retention (pAUR) is a known occurrence after robot-assisted laparoscopic ureteral reimplantation via an extravesical approach (RALUR-EV). We hypothesized that the risk factor of pAUR after RALUR-EV might be similar to that of pAUR after open reimplantation. We aimed at performing a retrospective multi-institutional study to evaluate the risk factors for pAUR after RALUR-EV. Materials and Methods: Perioperative data collected from two tertiary referral hospitals included demographics and perioperative variables such as bladder bowel dysfunction (BBD) status, vesicoureteral reflux (VUR) grade, and laterality. pAUR was defined as the need for urethral catheter replacement after removal of the initial postoperative catheter. Univariate and multivariate analyses were performed to identify risk factors for pAUR. Results: A total of 117 patients with 174 renal units from the 2 hospitals were enrolled in this study. The median age at the time of surgery was 5 (0.3-19) years. Bilateral RALUR-EV was performed in 57 (48.7%) cases. pAUR rate was 3.4% in all patients and 7.0% in 57 patients with bilateral VUR. All four cases of pAUR occurred after bilateral surgery. Univariate analysis showed age (p = 0.037), weight (p = 0.039), height (p = 0.040), and bilaterality (p = 0.037) as risk factors of pAUR. In a multivariate analysis, BBD was the only significant risk factor of pAUR (p = 0.037). Conclusion: Urinary retention after RALUR-EV occurred less frequently when compared with the previously reported open surgery series. pAUR was seen only in bilateral cases in our series. Preoperative history of BBD, but not male gender or length of surgical time, was the only risk factor of pAUR after RALUR-EV.

Robotics in Pediatric Urology: Evolution and the Future

Almost 30 years have passed since the inception of minimally invasive surgery in urology and specifically in pediatric urology. Laparoscopy has now become an essential tool in the pediatric urologic armamentarium. The application of robot-assisted surgery in pediatrics has allowed for widespread utilization for common reconstructive procedures such as pyeloplasty and ureteral reimplantation. Understanding the implementation, technical considerations, and outcomes are critical for continued success and adoption. This has allowed for increased use in more complex urologic procedures such as redo pyeloplasty, dismembered ureteral reimplantation, catheterizable channel creation, and bladder augmentation.

Does de novo hydronephrosis after pediatric robot-assisted laparoscopic ureteral re-implantation behave similarly to open re-implantation?

BACKGROUND

While open ureteral re-implantation surgery is the gold standard for surgical correction of vesicoureteral reflux (VUR), robot-assisted laparoscopic ureteral re-implantation via an extravesical approach (RALUR-EV) has become a minimally invasive alternative. Previous studies have shown that transient hydronephrosis after open re-implantation can occur in up to 28% of patients. However, previous studies have also shown that de novo hydronephrosis after open re-implantation is not predictive of final differential renal function.

OBJECTIVE

A retrospective review was performed to characterize the natural history of postoperative hydronephrosis after RALUR-EV for primary VUR in pediatric patients.

STUDY DESIGN

A retrospective chart review of a single-surgeon series was performed for pediatric patients who underwent RALUR-EV for primary VUR. The severity of de novo hydronephrosis was assessed using the Society for Fetal Urology (SFU) grading system via renal ultrasound at the 1-month postoperative follow-up. Renal ultrasound was performed at least every six months. Radiographic success was defined as complete resolution of VUR on the voiding cystourethrogram at the 4-month mark. Patient demographics, surgery duration, length of hospital stay, pre-operative and postoperative VUR grades, and follow-up time periods were collected. Patients with other associated urinary pathology and patients lost to follow-up were excluded from the study.

RESULTS

A total of 87 patients (121 kidney units) with primary VUR who underwent RALUR-EV met the inclusion criteria. SFU grade 1-3 hydronephrosis was noted in 30.3% (36/119) of kidney units at the 1-month mark, but 83.9% (26/31) cases with hydronephrosis completely resolved in a median time of 7.9 months (range: 3.4-21.0 months), and all four cases with unresolved hydronephrosis were downgraded to SFU grade 1 without the need for intervention.

DISCUSSION

A radiographic success rate of 96% was demonstrated in this cohort, which is comparable with that of historical open re-implantation series. A similar rate of de novo hydronephrosis was also noted in this cohort when compared with that of previous open re-implantation series, but de novo hydronephrosis after RALUR-EV had a similar or more rapid resolution rate than that previously reported after open intravesical and extravesical re-implantation series.

CONCLUSION

De novo hydronephrosis after RALUR-EV behaves similarly to de novo hydronephrosis after open ureteral re-implantation, where de novo hydronephrosis is present in up to 30% of pediatric patients who underwent RALUR-EV. The hydronephrosis self-resolves without the need for intervention in the overwhelming majority of cases and resolves at a median time of 7.9 months after surgery.

Lessons learned from a single-surgeon series of paediatric robot-assisted laparoscopic urological procedures: predictors of high-grade postoperative complications

OBJECTIVES

To describe postoperative complications after robot-assisted laparoscopic urological surgery in children, and identify potential predictors of these complications by analysing the outcomes of a large-volume single-surgeon experience.

PATIENTS AND METHODS

We reviewed our institutional database to identify all robot-assisted laparoscopy (RAL) cases performed between December 2007 and December 2017. Patients were grouped into three cohorts based on the anatomical location of the procedure: upper urinary tract (kidney and renal pelvis); lower urinary tract (ureter); and lower urinary tract reconstruction with bowel (bladder reconstruction). A descriptive analysis of baseline characteristics, intra-operative variables and postoperative outcomes was carried out. All complications were graded using the Clavien-Dindo scale, and grouped based on type and time of occurrence (<30, 30-90, >90 days). Multivariable logistic regression analysis was performed to identify predictors of high-grade complications (Clavien-Dindo grade ≥ III). We also measured complication rates based on year of surgery and surgical caseload.

RESULTS

Our database included a total of 326 patients, of whom 57% (n = 186) underwent upper urinary tract procedures, 30% (n = 97) ureteric procedures, and 13% bladder reconstruction. The median follow-up for each procedure was 13, 11 and 57 months, respectively. Of the total, 10 cases were converted to an open approach and excluded from further analysis. The most common types of complication in all groups were infections (urinary tract infections) and urinary complications (urine leaks and urolithiasis). Bladder reconstructive procedures, which require the use of bowel, presented the highest rate of high-grade complications (32%). Length of hospital stay (LOS; odds ratio [OR] 1.33, confidence interval [CI] 1.16-1.53), estimated blood loss (EBL) in surgery (OR 1.01, CI 1.002-1.019) and operating time (OR 1.004, CI 1.002-1.006) were all associated with increased odds of high-grade complications on multivariate analysis (P < 0.05).

CONCLUSIONS

In this single-surgeon series, we have described the most commonly encountered complications after RAL in paediatric urology, finding rates similar to the complication rates reported in the current literature on other surgical approaches. In addition, LOS, operating time and EBL, which are probable surrogates of case complexity, were associated with increased odds of high-grade complications.

The Future of Robotic Surgery in Pediatric Urology: Upcoming Technology and Evolution Within the Field

Since the introduction of the Da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) in 1999, the market for robot assisted laparoscopic surgery has grown with urology. The initial surgical advantage seen in adults was for robotic prostatectomy, and over time this expanded to the pediatric population with robotic pyeloplasty. The introduction of three-dimensional visualization, tremor elimination, a 4th arm, and 7-degree range of motion allowed a significant operator advantage over laparoscopy, especially for anastomotic suturing. After starting with pyeloplasty, the use of robotic technology with pediatric urology has expanded to include ureteral reimplantation and even more complex reconstructive procedures, such as enterocystoplasty, appendicovesicostomy, and bladder neck reconstruction. However, limitations of the Da Vinci Surgical Systems still exist despite its continued technological advances over multiple generations in the past 20 years. Due to the smaller pediatric market, less focus appears to have been placed on the development of the smaller 5 mm instruments. As pediatric urology continues to utilize robotic technology for minimally invasive surgery, there is hope that additional pediatric-friendly instruments and components will be developed, either by Intuitive Surgical or one of the new robotic platforms in development that are working to address many of the shortcomings of current systems. These new robotic platforms include improved haptic feedback systems, flexible scopes, easier maneuverability, and even adaptive machine learning concepts to bring robotic assisted laparoscopic surgery to the next level. In this report, we review the present and upcoming technological advances of the current Da Vinci surgical systems as well as various new robotic platforms, each offering a unique set of technological advantages. As technology progresses, the understanding of and access to these new robotic platforms will help guide pediatric urologists into the next forefront of minimally invasive surgery.

Robotic surgery in pediatric urology: Current status

Robot-assisted laparoscopic surgery (RALS) has been increasingly embraced in the fields of adult and pediatric urology, especially in North America and Europe. The advantages of a stable magnified 3-D view, tremor filtering, and motion scaling allow for precise intracorporeal exposure and suturing. Because most surgeries are performed as reconstructive rather than excision procedures, the robotic platform is particularly feasible for the field of pediatric urology. In this review, we summarize the recent viewpoints on RALS, such as pyeloplasty, ureteral reimplantation, bladder neck reconstruction, bladder neck sling, appendicovesicostomy, bladder diverticulectomy, and treatments for ureterocele or ectopic ureters, and we also critically summarize the current status of the literature. Based on our initial experience, RALS is technically feasible for pediatric patients and may be achieved with comparable surgical outcomes. RALS is also associated with reduced morbidity compared to open surgery to conventional laparoscopic surgery. This evolution will offer an alternative in the treatment pediatric patients, along with improved care and patient quality of life. Further large case series and randomized controlled trials that investigate the robotic platform's technological improvements will help to expand indications of RALS in the field of pediatric urology.

Minimally Invasive Surgery in Pediatric Urology: Adaptations and New Frontiers

As the frontiers of minimally invasive surgery (MIS) continue to expand, the availability and implementation of new technology in pediatric urology are increasing. MIS is already an integral part of pediatric urology, but there is still much more potential change to come as both recent and upcoming advances in laparoscopic and robotic surgery are surveyed.

Vesicoscopic cross-trigonal ureteral reimplantation: High success rate for elimination of primary reflux

INTRODUCTION

Open ureteral reimplantation (UR) is the gold standard for the surgical management of vesicoureteral reflux (VUR). There have been increasing reports on robot-assisted UR, but this approach remains controversial due to reports suggesting increased complications and reduced success compared with open repair. This study presented extensive experience with vesicoscopic ureteral reimplantation (VR) for primary reflux. In this procedure, cross-trigonal reimplantation was performed in a manner analogous to open repair under carbon dioxide 'pneumovesicum'.

OBJECTIVE

To review outcomes of vesicoscopic cross-trigonal ureteral reimplantation and compare them with other minimally invasive approaches for the correction of reflux.

STUDY DESIGN

All patients who underwent VR at the current institution were retrospectively reviewed. The following were recorded for each patient: age, sex, grade of reflux, operative time, outcome, and complications.

RESULTS

The series consisted of 182 consecutive patients who underwent VR. There were 165 girls and 17 boys. Mean age was 7.03 years (range 16 months-38.2 years). Fifteen had failed prior injection therapy. Of the 182 patients, 135 underwent bilateral repairs and 47 unilateral. Mean operative time for bilateral repairs was 197 (112-284) minutes and 169 (99-288) for unilateral. Major complications included two ureteral obstructions: one resolved with stent placement and the other underwent re-operative reimplantation. Postoperative voiding cystourethrogram (VCUG) was obtained in 100 patients and was normal in 93 (93%). Four of these failures occurred in the first 30 patients. Of the last 49 patients tested, 48 were normal, suggesting a 98% effective success rate after the learning curve.

DISCUSSION

Vesicoscopic ureteral reimplantation is an approach that completely recreates all aspects of open cross-trigonal repair. Complications were uncommon and success rates were very high in the current study.

CONCLUSIONS

Vesicoscopic ureteral reimplantation is a minimally invasive procedure for the definitive repair of primary reflux. After the learning curve at the current institution, success rates were found to be equivalent to open repair and were higher than published reports of robot-assisted procedures.