Single-port robotic ureteral reconstruction

8.1 Introduction

Prior to the da Vinci SP (Intuitive Surgical Inc.) surgical system’s introduction in 2018 and subsequent popularization in urologic robotic surgery, laparoendoscopic single-site surgery (LESS) was a technique that was introduced a decade prior to minimize port-related complications, decrease postoperative pain, and improve cosmesis ( Fig. 8.1 ). Despite its feasibility in urologic surgery to achieve those outcomes, LESS was not widely adopted due to its steep learning curve as well as the concurrent popularization of robotic-assisted laparoscopy. In particular, ureteral reconstruction is a suturing-heavy subset of urologic surgery, in which the ergonomics and wrist articulation advantages of robotic-assisted surgery is superior to that of laparoscopic technique. As the da Vinci SP system came out, the advantages of LESS were combined with the surgeon ergonomics of multiport da Vinci robots.

8.2 Advantages

The single port (SP) system allows for dynamic external range of motion, allowing the surgeon to change the target anatomy without redocking the robot or changing trocar position. This proves very useful when operating on organs far apart in the body, for example, in nephroureterectomy, where the surgeon can efficiently move from the kidney down the ureter to the bladder while not having to reposition the trocar (although undocking and putting the patient in Trendelenburg is helpful) and without the issue of clashing working arms. The majority of ureteral reconstructions (i.e., pyeloplasty, ureteroureterostomy, ureteral reimplantation) are surgeries on small areas in the body, so dynamic retargeting does not need to be utilized too often. Despite not needing to utilize this advantage because of the usually small area of target anatomy, the SP robot is advantageous in operating in tight regions that would otherwise be difficult for multiple arms to get into. One example of this is performing ureteral reconstruction in the retroperitoneal space, where it may be more difficult to place five trocars into limited mid-clavicular or flank territory, depending on body habitus. Another example of a region that may be accessed easier with the single-port robot compared to multiport is deep pelvis surgery for bladder neck or proximal urethral reconstructions.

8.3 Disadvantages

This first iteration of the da Vinci SP robotic system is not without its weaknesses.

A minimum distance of 10 cm (although upto 25 cm is ideal) between the end of the cannula trocar and the target organ should be met in order to allow for full deployment of the elbow and wrist angulation capabilities to minimize collisions during operation; this is generally not an issue when utilizing the SP Access Port Kit (Intuitive Surgical Inc.) ( Fig. 8.2 ), but selection of the initial incision must account for this minimum distance for surgeons who do not have the SP Access Port Kit and choose to utilize the Alexis wound protector with GelPort (Applied Medical, Rancho Santa Margarita, CA).

While there is no published study to date addressing the learning curve associated with the da Vinci SP robotic system, there have been multiple studies addressing a steeper learning curve in other single-site minimally invasive techniques across multiple surgical subspecialties. The learning curve with the da Vinci SP may be attributed to multiple factors, including less freedom with retraction, utilization of “elbow” instead of “wrist” articulation, and lack of certain instrumentation. With regards to retraction, the limitations of the da Vinci SP arms reside in the inability to move the arm too far away from the camera and other instruments–thus, retraction must be performed on a smaller scale with less tissue involved. An example of this is putting the renal hilum on stretch during a nephrectomy or partial nephrectomy: in the da Vinci Xi multiport system, the retracting arm can lift up between the psoas and the entire kidney; however, in the da Vinci SP single port system, the retracting arm would need to stay closer to the hilum so that the working arms can dissect out the vessels. Suturing with the da Vinci SP needle drivers is also slightly different from the da Vinci Xi and other previous multiport iterations, as there is somewhat less wrist articulation and more elbow articulation. As the da Vinci SP is in its first iteration, there are some instruments that have not yet been available to utilize, such as suture-cut needle drivers and vessel-sealing devices.

A popular tool in robotic ureteral reconstruction has been the use of indocyanine green (ICG) and Firefly fluorescence imaging (Intuitive Inc.), which is near-infrared technology that allows the surgeon to visualize the perfusions of tissue when ICG is administered intravenously or to visualize the ureter when surrounded by thick fibrosis when ICG is administered intraureterally. This first iteration of da Vinci SP robot does not come with Firefly technology.

Lastly, just how there is a learning curve with the console surgeon, there is also a learning curve with the bedside assistant. Some surgeons utilize the single-port “plus one” model, which is the single-site da Vinci SP access in addition to an assistant trocar through another incision, as it gives the bedside assistant more angles to retract when necessary and freedom from clashing with the robotic arms. The true single-port approach without a “plus one” involves the assistant port through the same single-incision; the proximity of the assistant port to the da Vinci SP port and working arms means that the bedside assistants have a limited radius that they may be able to assist and that clashing with the robotic arms is a frequent occurrence. This may make passing sutures, bulldog clamps, clips, and staples more difficult.

8.4 Access

The new SP Access Port Kit (Intuitive Inc.) serves to mitigate some of the limitations that come with the da Vinci SP system, including the minimum trocar to target organ distance and bedside assistance. It comes with the wound protector, as well as the clear spherical attachment which has three separate ports–one for the da Vinci SP trocar, one for 12 mm instrumentation, and one for an 8 mm assistant port on the side of the sphere. An Airseal (CONMED Corporation, Utica, NY) 8 mm trocar is typically used for the side port ( Fig. 8.3 ).

After docking the robot, there are some differences between the SP and multiport systems that the surgeon at the console will notice. A new schematic, called the Navigator, is at the bottom of the screen, mapping out the positions of each instrument in relation to each other, allowing the surgeon to identify the location of the instruments when not in view as well as troubleshooting instrument collisions. The Navigator will also show the angulation of the camera, which is the first fully elbowed 3D HD camera that can be bent into “cobra” configuration to articulate into 30 degree down.

The remotely operative suction irrigation system (ROSI) is very useful in SP robotic surgery. It is a flexible tubing with a short rigid tip that the surgeon is able to grasp and maneuver throughout the operative field. It is particularly useful in SP robotic surgery, as it is less ergonomic for the bedside assistant to utilize a rigid laparoscopic suction device without clashing with the robotic instruments in true single-site surgery. There are few circumstances where an additional assistant port may be placed into the abdomen that would allow the bedside assistant to be more active in the surgery, for example, when there needs to be additional retraction or more active suctioning.

8.5 Pyeloplasty

Pyeloplasty was one of the first urologic robotic surgeries, not just specific to ureteral reconstruction, to be performed utilizing the single-port robot. Ureteropelvic junction (UPJ) obstruction is a condition often diagnosed in younger patients, a population who seeks improved cosmesis. It is also a surgery with a small operative field, making the SP robotic system well-suited to complete the task effectively.

Patients are positioned in lateral decubitus, and the genitalia is often prepped into the field to be able to perform cystoscopy postureteral stent placement to confirm placement. Some surgeons do not perform cystoscopy to confirm the distal curl of the ureteral stent under direct visualization.

The SP robotic port placement can be variable for pyeloplasties, but usually are either periumbilical or “mini-Pfannenstiel,” as described by Kaouk et al., which is more accurately detailed as a transverse incision along Langer’s lines at the ipsilateral lower quadrant similar to that of a Gibson incision.

Intra-operatively, the surgical technique is similar to that of the multiport approach, where the UPJ is identified by reflecting the colon medially in most cases, and transmesenteric approach used in select pediatric cases. The literature on SP robotic pyeloplasty describe dismembered technique, excising the stenotic UPJ segment, spatulating the proximal ureter, and anastomosing the ureter to the renal pelvis with 4–0 absorbable suture over an indwelling ureteral stent. In the case of crossing vessels, the anastomosis is transposed anterior to the vessel ( Fig. 8.4 ).