Appropriate preoperative planning and meticulous surgical technique is paramount to preventing complications. All patients should have ultrasound, MRI, or CT imaging prior to repair. It is most helpful to have axial imaging to identify potential crossing vessels or aberrant vasculature at the renal hilum. Alternatively, a laparoscopic Doppler probe can be used to detect aberrant vessels [18]. Retrograde pyelography or a CT urogram prior to repair is important not only to define the character and extent of UPJ stenosis but also to document a normal distal ureter. In rare cases, retrograde pyelography may pick up a fibroepithelial polyp mimicking a UPJ obstruction. A mechanical bowel prep is helpful to increase working space and improve exposure. Placement of a preoperative or intraoperative stent or nephrostomy tube may be detrimental, especially to a novice robotic surgeon, as the specific site and length of obstruction may be difficult to identify and reconstruction of a decompressed renal pelvis becomes difficult.

A surgeon in the early phase of the RALP learning curve should use caution when taking on secondary UPJ cases. These can be difficult with significantly increased operative times and trends towards higher estimated blood loss (EBL) from inflammatory tissue and fibrosis in a previously operated field [19, 20]. However, in experienced hands, secondary pyeloplasty repairs using the robotic platform have shown equivalent success and complication rates as primary repairs [20]. The robot may be actually advantageous in the secondary repair cases as it offers better visualization and delineation of tissue planes when severe scarring is present. Unlike primary repair, a ureteral stent may be beneficial in the secondary repair to aid in ureteral identification intraoperatively [21]. Retrograde pyelography is mandatory to identify the location and extent of obstruction. Caution should be utilized when dissecting around the region of the UPJ as missed lower pole vessels (from previous pyeloplasty) have been noted in 22.2% of revision RALP surgery [22].

RALP is a delicate operation with few critical steps. In the most common transperitoneal approach, the colon and its mesentery are reflected medially to reveal the underlying kidney, renal pelvis, and ureter. The renal pelvis and ureter are freed of their surrounding attachments with care to avoid manipulation of the ureter and preserve periureteral blood supply. Once spatulated, the diseased UPJ segment can remain on the ureter as a handle to avoid touching the healthy ureter. Alternatively, a stitch can be placed near the apex of the spatulated ureter and used as a handle (Fig. 21.1). Once the renal pelvis is opened, a thorough irrigation should be performed intermittently to prevent the possibility of blood clot causing early obstruction in the postoperative period [23]. An intraabdominal drain should be placed at the conclusion of all procedures.

The robotic platform allows a surgeon to overcome one of the most technically challenging aspects of laparoscopy, which is suturing . The material of the suture itself may contribute to anastomotic strictures. Recently, barbed self-retaining sutures have been introduced to distribute tension equally throughout the anastomosis and overcome technically challenging aspects of laparoscopic suturing [24, 25]. However one report by highly experienced laparoscopic surgeons using a 4-0 Quill™ (Angiotech, Vancouver, British Columbia) showed 5/6 failures with UPJ stenosis after 1 month [26]. On the other hand, the RALP series, employing a 4-0 V-Loc™ (Covidien, Mansfield, MA), have shown successful results with this type of barbed suture [27, 28]. Investigators have hypothesized that the failure of the Quill suture report may lie in its bidirectional barbs design causing greater degrees of fibrosis compared to the unidirectional designed barbs on the V-Loc [27].

Ureteral stenting is important to minimize the risk of urinary leakage and failure. Antegrade placement (Figs. 21.2 and 21.3) can be easily performed over a guide wire. Prior to placement, we recommend that the Foley catheter be clamped in order to distend the bladder. If there is concern, a flexible cystoscopy can be performed to ensure placement in the bladder or a KUB prior to waking up the patient. As depicted in (Fig. 21.4) from a case report by Stravodimos et al. [29], a postoperative KUB on day 1 showed the ureteral stent not residing in the bladder from antegrade misplacement through the posterior anastomosis. In review of their own video, the authors attribute the complication to lack of proper visualization of the surgical field, overconfidence in stent placement, and lack of tactile feedback.

The instrumentation for RALP may make antegrade stent placement much easier than CLP. However, stent migration with the antegrade compared to the retrograde approach appears to be similar. Stent migration can be mitigated by erring on the side of using longer rather than shorter stents [23].

There are several technical points to consider in R-LESS for successful completion of the procedure. The robot should be docked more cephalad, which helps aim the camera directly at the UPJ . Maximizing instrument mobility is key and involves placing the robotic arm and camera ports slightly staggered from one another, as well as the use of a 30° lens in the “up” position, which allows the camera to reside inferior to the working arms inside the patient [15]. Range of motion can be increased by the “chopstick” technique described by Joseph et al. [11], where crisscrossed instruments are reprogrammed for intuitive instrument control such that the left instrument is controlled by the right hand effector and vice versa. The robotic camera lens and instruments must be moved synchronously, given their coaxial orientation relative to each other. Meticulous attention is paid to scaling down the degree of excursion of the instruments relative to the camera with each move. It is important to maintain hemostasis throughout the procedure as the surgical assistant is only able to provide limited help given the space constraints at the bedside.

Access may be obtained either by placing ports through separate fascial incisions, using a GelPort (Applied Medical, Rancho Santa Margarita, CA) device, or the Intuitive Surgical single-site port (Intuitive Surgical, Sunnyvale, CA). The advantage of using a GelPort includes reduced gas leakage, larger extracorporeal profile for port spacing, greater flexibility in port positioning, and the ability to have a small bedside assistant port [30]. The GelPort does require a slightly larger skin incision and could be potentially better for surgeries that involve eventual specimen retrieval.

All videos of RALP procedures should be recorded and easily retrieved for review. Intraoperative complications may not be recognized until the postoperative period and reviewing the video may identify a critical error. CT evaluation should be requested when the patient’s clinical status (pain, fever, leukocytosis, or decreasing hematocrit) cannot be explained by physical examination or routine clinical studies [31]. CT is the study of choice when evaluating a patient for decreasing hematocrit as it can help localize the site of bleeding. Although pneumoperitoneum is common after open surgery, if it is identified more than 24–48 h after robotic surgery, the possibility of a viscus injury in the proper clinical setting must be considered [31].

During early surgeon experience, certain postoperative complications may be noted more frequently, namely, urine leak and ureteral obstruction. Urine leak rate can range from 1.4% to 8.8% in RALP series (Table 21.2). Lower rates are seen in R-LESS series; however, the number of cases is much lower and the surgeons are highly experienced. Urine leak will usually manifest in the early postoperative period by persistently elevated drain output and this should be followed up by checking a drain creatinine level. If the level is higher than serum, urine leak should be confirmed by CT scan with delayed images. Of note, urine leak is associated with future pyeloplasty failure and should be managed urgently.