Laparoscopic and Robotic Pyeloplasty in Children

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Laparoscopic and Robotic Pyeloplasty in Children

Kai‐wen Chuang

Department of Urology, University of California, Irvine, CA, USA

Introduction

Traditionally, open pyeloplasty (OP) has been the gold standard for treating ureteropelvic junction (UPJ) obstruction in children, with a success rate of 97% in the reported literature. However, with continued advances in conventional laparoscopic and robotic surgical technology, as well as a general shift in patients’ and families’ mentality towards favoring minimally invasive interventions, these approaches play a growing role in pediatric pyeloplasty. In the past, conventional laparoscopic pyeloplasty (C‐LP) has been demonstrated to be equivalent to open surgeries in terms of preservation of differential renal function [1]. The technical challenges in C‐LP largely lies in the need for intracorporeal suturing, which has been subsequently rectified by improved dexterity offered by robot‐assisted laparoscopic pyeloplasty (RA‐LP). The superiority of the laparoscopic approach over the open approach, with or without robotic assistance, is believed to lie in its decreased morbidities in terms of length of stay and pain medication requirement [2, 3]. This chapter reviews the strategies, techniques, and outcomes of laparoscopic and robotic pyeloplasty in children, as well as providing literature updates from the past 10 years, given that there has been a dramatic increase in relevant studies since the last edition of this chapter was published in 2012.

Background

In 1993, laparoscopic pyeloplasty was first described in adult patients concurrently by two groups [4, 5]. Two years later, in 1995, its pediatric application was first described by Peters et al. in a 7‐year‐old boy with right UPJ obstruction, using the classic Anderson–Hynes dismembered technique, interrupted sutures, a nephrostomy tube as drainage, and 5 hours of total operative time [6]. More than a decade later in 2007, Olsen et al. reported their favorable 5‐year experience with robot‐assisted retroperitoneoscopic pyeloplasty (RA‐RP) in treating UPJ obstruction in 67 children, demonstrating shorter operative times and comparable complication rates compared to other approaches.

Minimally invasive surgery has unique benefits in the pediatric population with respect to cosmetic outcomes, as well as psychological and social impact on the caregivers. It has been demonstrated that up to 83% of parents believe the scar size for pyeloplasty is important [7], and a validated questionnaire showed higher parental satisfaction rates for RA‐LP over OP with regard to size of the incision scar, burden of postoperative follow‐up, and overall life [8]. In addition, shorter length of stay (LOS) associated with RA‐LP was correlated to an average saving of US$90.01 in parental wage loss and US$612.80 in hospital expenses [9].

However, these financial considerations must be weighed against the cost of purchasing and maintaining a robotic platform and instruments. Although Liu et al. did not find any differences in overall costs between minimally invasive pyeloplasty and OP, Bennett et al. reported that robotic cases were more expensive by US$3991, with operating room charges and anesthesia charges dominating the cost difference [10, 11]. Some centers have been successful in overcoming the higher costs associated with RA‐LP by high surgical volumes, as Sorensen et al. observed that operative times for RA‐LP were initially longer than those for OP, but became equivalent after 15–20 cases [12]. Having a dedicated robotic team in the operating team also improves efficiency and minimizes cost while maximizing safety.

With RA‐LP rapidly showing signs of becoming the new gold standard for treating UPJ obstruction in children, it cannot be stressed enough that ultimately the decision‐making regarding which surgical approach to take should be based on availability of equipment, family preference, and surgeon skillset and comfort.

Indications

The indications for minimally invasive pyeloplasty are identical to those for OP, and include decreasing split renal function, increasing hydronephrosis, urinary tract infections or pyelonephritis, symptoms such as intermittent flank pain, nausea, or vomiting, and presence of nephrolithiasis [13].

There have been encouraging reports of expanding the application of RA‐LP to include younger children and infants. The largest series of such nature was a multicenter retrospective review from Avery et al., examining the outcomes of 60 infants with a mean age of 7.3 months. It found 91% of the children with improved or resolved hydronephrosis, while 3.3% (2 patients) required reoperation due to recurrent obstruction [14]. Boysen and Gundeti detailed their suggestions for successful infant pyeloplasty from a technical standpoint, including positioning, port placement, lens degrees, and insufflation pressure [15].

However, overall, infant RA‐LP remains in its early stages and it is standard practice at our institution to perform infant pyeloplasty cases via an open dorsal lumbotomy or flank approach. Interestingly, a recent crowd‐sourced survey showed that the majority of patients would prefer the dorsal lumbotomy scar over flank and laparoscopic incisions, if given as an option [16]. We reserve minimally invasive pyeloplasty for older children and teenagers, with RA‐LP being our first choice, and rarely C‐LP if operating at an affiliated hospital without the robotic equipment.

Patient preparation and operative setup

Here we describe the steps for a routine RA‐LP performed at our institution. The steps for a routine C‐LP are identical.

Bowel preparation

Although some authors advocate for a liquid diet for 24 hours prior to laparoscopic surgeries and a single rectal suppository of oral bowel stimulant to clear the colon, we have not found routine preoperative bowel preparation to be necessary.

Retrograde pyelogram and stent placement

As indicated above, our standard approach for infant pyeloplasty is via an open dorsal lumbotomy incision. As such, we routinely perform a preoperative retrograde pyelogram to assess possible kidney rotation, concomitant ureteral obstruction, and length of ureteral narrowing. Narayanan et al. reported that preoperative retrograde pyelogram can provide additional information in up to 19% of cases [17]. Following this practice, we also perform a routine retrograde pyelogram before our minimally invasive pyeloplasty cases.

However, there is variation among our partners regarding stent placement. For some, an internalized double‐J ureteral stent is always placed in a retrograde fashion at the end of the retrograde pyelogram. They cite confirmation of distal curl in bladder by direct cystoscopic vision and not having to negotiate the ureterovesical junction (UVJ) blindly as major advantages over an antegrade stent placement approach. In this case, the bladder would be left full by clamping the urethral Foley catheter so that the renal pelvis can remain distended to facilitate dissection.

For others, an antegrade stent placement approach is preferred due to the added difficulty in intracorporeal suturing by the proximal curl of the stent interfering with visualization of the surgical field. This is the preferred approach by this author and will be discussed in more details in later sections. A Foley catheter is placed per urethra at the end of the retrograde pyelogram.

Positioning

The patient is placed in the lateral decubitus position with the operative side up and rotated approximately 30° from the vertical plane. This position is maintained with one or two large gel rolls behind the patient. In order to maximize the movement range for the robotic arms, it is beneficial to have the front side of the patient as close to the edge of the operating room table as possible. Sequential compression devices are placed on bilateral lower extremities. The bottom leg is bent while the upper leg is straight, with a pillow in between them. The contralateral arm is extended and secured to a padded arm board, while the ipsilateral arm is folded across the chest. Care is taken to ensure that all bony prominences are well padded and protected. The patient is then secured to the table using folded blue towels and silk tape at three levels, across the chest, across the hip, and across the legs. The security of strapping is then tested by rolling the patient prior to draping. It is important to work closely with the anesthesia team, as the head may also need to be secured. An orogastric tube is placed for left‐sided procedures. The patient is prepped over the entire abdomen from xyphoid to pubis.

Access and port placement

For patients without prior abdominal surgeries, entry into the peritoneum is obtained via a Veress needle after making an incision at the base of the umbilicus with an 11 blade. Countertension is provided by a pair of symmetrically placed perforating towel clamps. For patients with history of prior abdominal surgeries, an open Hasson technique is the preferred method, given its inherent safety. Successful entry is confirmed by a satisfactory “saline drop” test, no bloody or bilious return on aspiration, and symmetric, four‐quadrant insufflation with low starting pressure. Typically, a 5 mm port is first placed through the self‐dilating sheath at the umbilicus and a 0° or 30° laparoscope is used through this port to facilitate placements of the two 8 mm robotic ports under vision, one cranial to the umbilical port in the midline and a second equidistant from the umbilical port in a caudal direction approximately 30° off the midline. Care is taken to ensure that there is at least a 6–8 cm distance between ports to maximize robotic arm movements. An additional 5 mm assistant port can be placed as needed to allow for passing of sutures, suctioning, and/or liver retraction for right‐sided cases. At this point, the laparoscope is switched to one of the working ports looking back at the umbilicus, and the previously placed temporary 5 mm port is then upsized to a 12 mm robotic camera port under vision.

Procedure in detail

Following port placement, the robot is docked, and the procedure begins with identifying the dilated renal pelvis. For dissection, this author prefers monopolar scissors in the right hand and bipolar grasping forceps in the left. For left‐sided cases, a transmesenteric approach is preferred if possible. Otherwise, a retrocolic approach would be appropriate if a dilated pelvis is not readily visible through the colonic mesentery. The colon is mobilized by incision of the white line of Toldt and reflected medially. The hepatic flexure and the duodenum may need to be mobilized for right‐sided cases, and the splenic flexure may need to be mobilized for left‐sided cases in order to reveal the UPJ.

After the UPJ is successfully identified, dissection is carried out carefully while maintaining the ureteral blood supply. In our experience, a hitch stitch with 3‐0 Prolene is very useful at this time to permit lifting, exposure, and stabilization of the UPJ and proximal ureter. This is placed percutaneously through the abdominal wall using either a straight Keith needle or a straightened needle through the renal pelvis and back through the abdominal wall. Tension can be adjusted by placing a pair of clamps on the extracorporeal ends of the suture at different levels. This maneuver also lefts the anastomotic area away from any potential pools of urine and blood.

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