Robotic-Assisted Laparoscopic Pyeloplasty Technique

Updated: Jul 07, 2016
  • Author: Chandru P Sundaram, MD; Chief Editor: Edward David Kim, MD, FACS  more...
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Technique

Laparoscopic Pyeloplasty With Robotic Assistance

Port placement

With the patient rotated to almost a supine position, pneumoperitoneum is created via a Veress needle placed at the umbilicus. After insufflation to a pressure of 15 mm Hg, a 12-mm bladeless trocar is inserted at the umbilicus. A regular 10-mm laparoscope is inserted, and the abdominal cavity is inspected for injury and adhesions. On the right side, a 5-mm subxiphisternal port is inserted to allow retraction of the liver[link “liver” to Medscape topic Liver Anatomy].

The table is now rolled toward the surgeon so that the patient is at a 90° angle relative to horizontal. Additional trocars are placed according to 1 of the following 3 configurations:

  • Lateral laparoscope position
  • Modified paramedian position
  • Medial position

Lateral laparoscope position

The lateral laparoscope position (also referred to as the diamond pattern) is used for robotic-assisted laparoscopic pyeloplasty (RLP) in pediatric patients and smaller adults. A 12-mm port for the robotic camera is situated 2 cm medial and inferior to the tip of the 12th rib, approximately along the anterior axillary line. At this position, the robotic camera is placed with the lens facing upward at a 30° angle.

Next, a pair of 8-mm robotic trocars are placed. The first is placed 2 cm inferior to the costal margin, just medial to the midclavicular line, and the other is placed 2 fingerbreadths superior to the iliac crest, just lateral to the midclavicular line. If the fourth robotic arm is used, the third 8-mm trocar can be placed medial and inferior to the lower robotic port, almost at the suprapubic region (see the images below). After the patient cart is docked, the 12-mm umbilical port is used for the assistant’s instruments.

Diagram of port placement with robotic laparoscope Diagram of port placement with robotic laparoscope placed laterally.
Intraoperative view of port placement. Intraoperative view of port placement.

Modified paramedian position

In most adults, the laparoscope can be moved medially toward the lateral border of the rectus abdominis or the midclavicular line about 3 cm above the level of the umbilicus. The 8-mm trocar for the right-hand robotic instrument is inserted in the subcostal location in line with the laparoscope. The 8-mm trocar for the left-hand robotic instrument is inserted between the umbilicus and the anterior superior iliac spine.

Medial position

The robotic camera can also be placed through the umbilical port. When the camera is inserted in this medially located position, it should be oriented so that the lens faces downward at a 30° angle.

Mobilization of ureteropelvic junction

The first step in exposing the ureteropelvic junction (UPJ) is to reflect the colon[link “colon” to Medscape topic Colon Anatomy] by incising the line of Toldt. The plane between the colon and mesocolon and Gerota’s fascia is developed as the colon is reflected medially. In thin patients with minimal mesenteric fat, left-side exposure can be achieved via the transmesocolic approach. [43]

The next landmark is the gonadal vein, which can be identified at the level of the lower pole of the kidney after adequate medial mobilization of the colon. Posterior to the gonadal vein, the psoas fascia can be seen. In this region, the ureter can usually be identified. At this point, the Foley catheter is clamped to allow urine to flow back up the stent and distend the renal pelvis.

The ureter is freed proximally until the renal pelvis is exposed. During this step, it is important to watch for crossing vessels, which, if present, should be dissected off the UPJ (see the video below). The periureteral tissue should be preserved during dissection to avoid the complication of late ischemic stricture.

Robotic-assisted laparoscopic pyeloplasty: mobilization of crossing vessels.

The perirenal fat around the pelvis and retroperitoneal fat around the proximal ureter may make exposure difficult. Retraction sutures can be used to facilitate exposure of the UPJ without the use of another trocar or instrument. These may be sutured to surrounding fascia laterally to facilitate the rest of the surgery (see the video below).

Robotic-assisted laparoscopic pyeloplasty: retraction sutures.

In addition, the authors routinely place stay sutures on the renal pelvis and proximal ureter to facilitate handling of the tissues during dismembering of the UPJ (see the video below).

Robotic-assisted laparoscopic pyeloplasty: placement of stay sutures.

With the renal pelvis distended, the narrowed segment of the UPJ is identified. The cephalad robotic instrument is changed to Potts scissors. While the tissues are being handling with the stay sutures, the medial edge of the renal pelvis is incised 2 cm above the narrowed segment. The incision is carried along the anterior wall of the pelvis, extending inferolaterally until the lateral edge of the UPJ is reached.

The angle of the scissors is then turned inferiorly to spatulate the lateral wall of the ureter for about 1-3 cm, depending on the redundancy of the pelvis and ureter and the degree of tension. Dismemberment is completed by dividing the posterior wall of the renal pelvis parallel to the anterior wall. Spatulation of the ureter before dismemberment helps maintain the correct orientation of the ureter during spatulation. The UPJ remains attached to the ureter, serving as a handle for manipulation during anastomosis (see the video below).

Robotic-assisted laparoscopic pyeloplasty: dismemberment and spatulation.

Anastomosis

Once the UPJ is dismembered, the next step is to make an assessment of the obstructive nature of any crossing vessels present. If necessary, the vessels may be transposed posteriorly. The ureter and the pelvis are then brought together for assessment of the degree of tension. Additional ureteral mobilization may be performed at this stage if necessary. Redundant pelvis may also be excised to achieve a funnel-shaped anastomosis.

The anastomosis is created with 4-0 or 5-0 polyglactin suture on an RB-1 needle. On the left side, starting with the ureter, the needle is passed from out to in at the apex of the spatulation. The suture is then passed from in to out at the lateral edge of the pelvis, and the knot is tied. On the right side, suturing is begun at the lateral edge of the renal pelvis from out to in, then continued from in to out through the ureteral spatulation.

In both cases, the posterior wall is first performed with a continuous stitch and ended medially with the needle on the outside. Interrupted sutures may also be used, especially for the posterior layer. Sutures should be carefully handled to ensure that they are not weakened or frayed.

After the posterior wall is completed, a final assessment of the patency of the anastomosis is made by using a 5-French infant feeding tube inserted alongside the stent into the ureter (see the video below). The renal pelvis is irrigated copiously to flush out any clot that might cause transient stent obstruction postoperatively.

Robotic-assisted laparoscopic pyeloplasty: infant feeding tube.

The proximal coil of the stent is replaced into the renal pelvis, and the anterior wall of the anastomosis is begun. A new suture is used for the anterior wall, starting laterally in a similar fashion and continued medially. The anterior suture is tied to the free end of the posterior suture to complete the anastomosis (see the video below).

Robotic-assisted laparoscopic pyeloplasty: anastomosis.

After the anastomosis has been completed and hemostasis ensured, all stay sutures are removed. The instruments are removed, and the arms are undocked from the ports. A 10-French or 15-French round drain is placed through one of the 8-mm ports and connected to bulb suction. The fascial openings at the 12-mm port sites are closed. In children, the fascial openings at all trocar sites are closed.

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Complications

Intraoperative

Intraoperative complications during RLP are rare, with frequencies ranging from 0-2%. [34, 35] Such complications include elective conversions, splenic and liver lacerations caused during instrument exchange, and minor bowel injuries. Major vascular injuries are extremely rare.

Early

Urine leakage occurs during the early postoperative period in 2% of cases. [36] This is manifested as increased drainage output with a fluid creatinine concentration consistent with that of urine. It can be caused by transient obstruction by blood clot, a kinked stent, migration of the distal end of the stent up the ureter, or a disrupted anastomosis.

Abdominal radiography should be performed to confirm the position of the stent. A migrated or kinked stent should be adjusted ureteroscopically. Percutaneous nephrostomy may aid in additional drainage if necessary. A disrupted anastomosis is best treated by means of surgical revision. Intravenous antibiotic therapy should be instituted and computed tomography ordered with a view to draining any abscess or collection.

Late

Persistent obstruction during follow-up renograms occurs in fewer than 10% of cases. [37] Treatment of persistent obstruction will depend on the surgeon’s experience and the patient’s preference. Both endopyelotomy and repeat pyeloplasty have been used in cases of secondary UPJO, with reported success rates exceeding 80%. [15, 44]

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