Abstract
Extravesical robotic-assisted laparoscopic ureteral reimplantation in children is a challenging procedure. Our top-down suturing technique facilitates this reconstructive surgery. After mobilization of the ureter without the use of ureteral stent placement, the detrusor muscle is divided. Once adequate muscle flaps are raised, the ureter is placed into its new muscle tunnel. Unlike previously described techniques, the top-down suturing approach involves placement of the first detrusor stitch at the superior aspect. This allows the ureter to be elevated out of harm's way and in a tension-free manner. The rest of the detrusor reapproximation is performed in a top-down approach with interrupted sutures without the need for ureteral elevation or manipulation. This technique facilitates the suturing process and decreases trauma to the ureter with less instrument contact. This helps to prevent potential complications and improve success rates associated with this procedure.
Introduction
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There has been a growth in surgeons' experience with extravesical robot-assisted laparoscopic ureteral reimplantation (RALUR-EV) in children compared with intravesical RALUR. 2,3 Several centers have reported success rates similar to historic open surgery success rates that have also been accompanied by decreased hospital stay lengths and decreased morbidity such as postoperative pain and bladder spasms. 4 –6
Generally, the suturing direction during robotic reimplantation has been described from the bottom to the top. 3,7,8 We describe our top-down technique that facilitates the suturing process with retraction of the ureter out of harm's way and decreases trauma with less instrument contact. This helps to prevent potential complications and improve success rates associated with this procedure.
Technique
Patient selection
After obtaining Institutional Review Board approval, we retrospectively reviewed our experience with RALUR-EV. Children undergoing extravesical ureteral reimplantation by a single surgeon (CJK) using the da Vinci Surgical system (Intuitive Surgical, Sunnyvale, CA) for primary VUR were included. Patients' charts and video records were investigated. Exclusion criteria included patients more than 18 years old and children with other associated urologic abnormalities such as bladder diverticula, megaureter, ectopic ureter, and uretereovesical junction obstruction.
Positioning, trocar insertion, and robot docking
The procedure starts with a diagnostic cystoscopy to evaluate the bladder anatomy and the ureteral orifice locations. Then the patient is placed in a supine position and secured to the table across the legs, chest, shoulders, and head with the use of silk tape. Afterward, the Trendelenburg position (30 degrees) is achieved to allow the abdominal contents to fall away from the surgical area. The camera trocar (8.5 or 12 mm) is placed through the lower edge of the umbilicus by an open Hasson technique.
After pneumoperitoneum is achieved, two more trocars (5 or 8 mm) are inserted under visualization along the axillary line at the level of the umbilicus on both sides. These ports are used for the robotic instruments. An optional accessory port (5 mm) for retraction or suture delivery can be placed in the left or right upper quadrant and midway between an instrument port and the camera port. After completion of the trocar placements, the robot is then brought in over the patient's feet, and docking is performed.
Operative technique
A transperitoneal approach with traditional Lich Gregoir technique is used in all cases. An inverted T incision is made in the peritoneum to create a peritoneal window that exposes the posterior bladder wall. After entry into the perivesical space, the ureter is located on the affected side and gently mobilized proximally to the level of the iliac vessels. If necessary, a hitch stitch with 4-0 polypropylene suture can be placed through the abdominal wall, through the bladder dome, and back out the abdominal wall for retraction. This maneuver facilitates ureteral mobilization and creation of the muscle tunnel.
During mobilization of the ureter, extensive dissection on the posterior-lateral aspect of the bladder is avoided to help preserve the neurovascular bundles of the bladder and avoid potential voiding issues such as urinary retention with bilateral cases. 6 In addition, it is important to mobilize the ureter proximally underneath the vas deferens or uterine artery about 4 to 5 cm to achieve a sufficient length for reimplantation.
To create the extravesical trough, the detrusor muscle is split along its new intended muscle tunnel with hook electrocautery in a superior-medial direction to create a 5:1 tunnel length/ureter diameter ratio. Then the detrusor muscles are separated until the mucosa is identified. The detrusor flaps are prepared by separation of the muscle layer from the mucosa with careful dissection with the hook cautery.
Top-down suturing approach
After achieving sufficient mobilization of both the ureter and the detrusor flaps, the ureter is then elevated to approximate its intended position ensuring 5:1 tunnel length/ureter diameter ratio. Unlike other previously described techniques, 3,7,8 we always place the first stitch (4-0 absorbable polydiaxanone [PDS]) on the superior side of the new muscle tunnel, which leads to creation of the new muscle hiatus (Fig. 1). This allows for the ureter to be elevated without tension. The complete mobility of the ureter can be verified at this stage.
Suturing process of “top-down” approach. (
Then the detrusor flaps are wrapped around the ureter by suturing the rest of the length of the muscle flaps with interrupted 4-0 PDS suture. The rest of the detrusor reapproximation via the top-down approach avoids the necessity of ureteral elevation with one of the instruments. Another important step is using an interrupted suturing during the muscle reapproximation.
The bladder is then partially filled with saline to observe the angulation of the ureter and to ensure the watertight closure. Then the procedure concludes with closure of the peritoneum using 4-0 polyglactin suture. A Foley catheter is left in place for 24 hours postoperatively.
Equipment
• Flexible or semirigid pediatric cystoscope
• Foley catheter
• da Vinci Surgical Robot Hook cautery (5 mm)
• DeBakey forceps (5 mm)
• Needle driver (5 mm)
• 4-0 PDS suture
Role in Urologic Practice
Over the past 10 years, robot-assisted laparoscopic surgery has been adapted increasingly into the pediatric urology field, and several clinical series have been published. 3 –10 RALUR-EV is one of the procedures that has increased in volume because of its reproducibility. Early pediatric series reported operative success rates that approached those of the traditional open approaches. 9 In that initial report, the VUR resolution rate was 88.4%, and one patient of 17 who had undergone bilateral reimplantation experienced transient voiding difficulty that resolved on its own. It is understandable, however, that the new technological devices need time for surgeons to overcome the learning curve, and the results of the later published reports are comparable to those of open extravesical ureteral reimplantation.
Kasturi and colleagues 10 recently published a long-term analysis of RALUR-EV in 150 pediatric patients. After 2 years of follow-up, the operative success was 99.3% as defined by resolution of reflux during postoperative voiding cystourethrography (VCUG), and the rate of postoperative voiding dysfunction as evaluated by a validated screening tool was low, with no reported cases of urinary retention.
Two other series compared RALUR with open surgery. Smith and coworkers 4 presented a retrospective study of 50 children in which half of them underwent RALUR-EV and the other half underwent open Cohen cross-trigonal reimplantation. Although the mean operative time was longer in the robotic group, the length of hospital stay and the postoperative analgesia requirement were significantly lower. After a mean follow-up of 16 months, the success rates were comparable with only one failure in the robotic group.
To decrease the complication rates of RALUR-EV, some investigators have highlighted the importance of a nerve-sparing approach. Casale and associates 6 reported a case series of nerve-sparing RALUR-EV in 41 children. They reported no cases of urinary retention in their series with a success rate of 97.6%. The authors suggested that preservation of the pelvic plexus during the ureteral mobilization at the level of the hiatus may have led to their high operative success rates.
In summary, the operative experience with RALUR-EV is still continuing, and the steps of the surgery are evolving to achieve the high success rates associated with open surgery. We have described a modified suturing technique for RALUR-EV that aims to decrease the instrument-related contact with the distal ureter and avoids use of a ureteral stent. In previously described RALUR-EV techniques, the detrusor muscle closure started from the bottom to the top. 3,7,8 This can be associated, however, with manipulation of the ureter with one of the instruments to complete the suturing process and therefore has the potential for complications.
Hence, unlike the previously described techniques, we place our first detrusor closure stitch on the superior side in an interrupted fashion that creates the new muscle hiatus. This elevates the ureter without tension or manipulation. Furthermore, the rest of the suturing process is facilitated; it allows both instruments to be used because the ureter is already out of harm's way.
Over the past 7 years, we have performed our modified suturing technique in 114 ureters in 89 children (25 bilateral cases). All patients were followed with serial renal ultrasonography, and the success of a procedure was confirmed by either a postoperative VCUG or nuclear cystography.The mean age was 5.4±1.9 years. From the complete available data in 72 children and 91 units, the operative success as defined by complete resolution of VUR was 97.9%. Two patients who underwent bilateral reimplantations had temporary postoperative urinary retention develop; this self-resolved after 2 weeks of Foley catheter drainage of the bladder, leading to a complication rate of 2.7%.
Conclusions
Our modified technique, the top-down approach without ureteral stent placement, facilitates the suturing process during RALUR-EV. In addition, because of minimized contact with the ureter, this technique decreases instrument-related trauma and reduce the potential for perioperative complications.
Footnotes
Acknowledgment
Dr. Silay is partly sponsored by TUBITAK, a Turkish funding agency. Dr. Koh is sponsored by a grant from the Texas Children's Hospital Auxiliary.
Disclosure Statement
No competing financial interests exist.
Abbreviations Used
References
Supplementary Material
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