Single Institution Experience with Robot-Assisted Laparoendoscopic Single-Site Renal Procedures

Introduction

L aparoscopic surgery has become increasingly popular in urology because it results in improved cosmesis, decreased pain, and faster recovery. To further minimize the morbidity of laparoscopy, newer techniques such as laparoendoscopic single-site (LESS) surgery have been introduced. Raman and associates ¹ were the first to test the feasibility of keyhole nephrectomy in 2007. In the same year, Rane and colleagues ² performed the first clinical cases of single-port surgery using a multichannel port: A nephrectomy and pyelolithotomy. ²

Although numerous reports of LESS procedures have been published in the literature, persistent obstacles remain that impede its widespread dissemination throughout the urologic community. These include working with an in-line view, clashing of instruments, difficulty with tissue retraction, and loss of triangulation. To overcome these obstacles, articulating instruments and specially designed laparoscopes have been used, yet still require a significant learning curve for their mastery and pose significant ergonomic challenges. In this regard, the daVinci Surgical System (Intuitive Surgical, Sunnyvale, CA) has recently been introduced to facilitate surgeon ability and comfort during LESS procedures.

The objective of the current study is to review our experience and report our results with robot-assisted LESS (RLESS) kidney procedures.

Patients and Methods

Analysis of our Institutional Review Board approved, prospectively maintained LESS database revealed 28 RLESS renal procedures performed from May 2008 to February 2011: 11 radical nephrectomies, 5 partial nephrectomies, 1 simple nephrectomy, 3 nephroureterectomies, 7 pyeloplasties, and 1 renal cyst decortication.

Our procedure has been reported. ^{3 –6} Briefly, the patient is placed in a modified flank position. The robotic system is placed over the shoulder of the patient with the center of the patient-side cart aligned with the kidney. A skin incision (range 3–6 cm depending on the size of the specimen for extraction) is placed through the umbilicus, and a multichannel port is inserted using an open Hassan technique. Initially, we routinely used the TriPort (Advanced Surgical Concepts, Dublin, Ireland). Recently, however, either the SILS port (Covidien, Norwalk, CT) or the GelPoint (Applied Medical, Rancho Santa Margarita, CA) have been used increasingly.

If a SILS port is used, a 12-mm robotic camera port is placed through the port, and two additional robotic trocars are placed through separate fascial incisions, tunneled under finger guidance, as far from the single port device as possible. The assistant works through one of the 5-mm sites within the SILS port. If a GelPoint is used, all ports are placed directly through the single port platform. The 12-mm trocar for the camera is placed in the most medial position, and two 8-mm trocars are placed laterally near the edges of the cap. An assistant port is placed between the camera and robotic ports. A three-arm robotic approach is used. If during the procedure leakage of carbon dioxide occurs through the single port device, the trocar sites are packed with petroleum gauze to maintain pneumoperitoneum.

The daVinci S or Si robot is used because of superior optics and longer instruments compared with the first generation system. The size of trocars varies from standard 8-mm to pediatric 5-mm instruments, depending on the procedure to be performed and surgeon preference. The surgery is then completed using techniques similar to the standard robotic approach.

For nephrectomy, after docking, the colon is mobilized medially using robotic grasper and shears. The ureter is then identified and mobilized superiorly to the renal hilum. Hilar dissection is then performed using the robotic shears or hook. The renal hilum is controlled using robotically applied Hem-o-lok clips. The remainder of the kidney attachments are divided. Dissection of the upper pole in right-sided cases can be challenging, secondary to inability to retract the liver. In this situation, the pediatric 5-mm instruments are advantageous because they deflect rather than articulate. The shaft of the robotic instrument can be used to elevate the liver, and the distal tip is used to perform the dissection. Lastly, the ureter is transected, and the specimen placed in an endocatch bag and extracted through the umbilical incision.

For partial nephrectomy, the colon is mobilized followed by identification of the ureter and dissection of the renal hilum as described previously. The kidney is then defatted and the tumor exposed. A 5-mm suction tube, prebent 30 degrees downward, can be inserted through one of the working channels of the SILS port or through a 5-mm port for the GelPoint and can be used for suction, irrigation, and retraction during the procedure. In the current series, partial nephrectomies were performed using an unclamped technique. Resection was performed using electrocautery, harmonic scalpel, and clips. Hemostasis was achieved using the argon beam coagulator and FloSeal (Baxter, Deerfield, IL). After resection and reconstruction, a closed suction drain is placed. The specimen is then placed in an endocatch bag and extracted through the single port site.

Different approaches have been used for nephroureterectomy. Initially, the TriPort was placed at the umbilicus for the nephrectomy, and then a Gibson incision was used for dissection of the distal ureter. In our second procedure, we placed the GelPort through a Gibson incision to attempt the nephrectomy and then used the same incision to manage the distal ureter. Recently, we placed the GelPort at the umbilicus to perform the nephrectomy. After nephrectomy, the Gelport was reoriented toward the pelvis to perform the ureterectomy robotically through the same site.

For pyeloplasty, after docking of the robot to the multichannel port, the previously stented ureter is identified. The ureter is mobilized using robotic shears up to the renal pelvis with care taken to avoid injury to any crossing vessels that may be present. The abnormal segment of ureter is then excised and the ureter transposed anterior to the crossing vessel. The ureter is spatulated and a watertight anastomosis is performed over the indwelling ureteral stent using two sutures of 4-0 polyglactin. A closed suction drain is left in place.

The instruments and positioning used for renal cyst decortication are the same as described previously. After mobilization of the colon and exposure of the cyst, the cyst wall is amputated and the epithelial lining is cauterized.

Results

Discussion

Since the first laparoscopic nephrectomy, ⁷ advances in instrumentation have allowed increasingly complex procedures to be performed with minimally invasive techniques. Similarly, the ergonomic advantages and precision afforded by robotics would seem to make this technology uniquely suited to help make LESS more practical.

White and associates ⁶ reported their experience with 10 RLESS radical nephrectomies. In a retrospective comparison with 10 conventional laparoscopic radical nephrectomies, they noted no difference in operative time, estimated blood loss, visual analogue pain scale, or complication rate. They did, however, note that the RLESS cohort had a lower narcotic requirement and shorter hospital stay.

Pyeloplasty remains one of the ideal procedures for LESS. It does not need an extraction incision and occurs in a younger patient population likely more interested in aesthetic outcomes. Care must be taken, however, to avoid creating too small an incision, thereby preventing adequate separation of the robotic arms: In the current series, two of seven cases needed conversion secondary to clashing of the robotic arms. Joseph and colleagues ⁸ in a box trainer determined that optimal positioning for RLESS would be a triangular port arrangement with 2 cm distance between trocars.

Partial nephrectomy represents a challenging surgery under the best of conditions. Initially, Kaouk and Goel ⁴ performed unclamped resection on all patients. Further, they chose low to interpolar masses to avoid the need for a liver retractor. Based on their early experience, they thought that small, exophytic, anterior, interpolar to lower pole renal masses were best suited to the LESS and/or RLESS approach.

Han and coworkers ⁹ have described their technique of RLESS partial nephrectomy for malignancy. Fourteen cases were reported using a homemade single port access device. Mean tumor size was 3.2 cm, mean warm ischemia time was 30 minutes (range 16–43 min), mean operative time was 233 minutes, and all patients' results showed negative margins. Mean estimated blood loss, however, was 464.6 mL (range 30–1850 mL), 11 patients needed blood transfusions, and 2 patients' procedures needed conversion to open surgery. They have subsequently updated their RLESS experience. ¹⁰ They reported on 73 RLESS cases including 1 simple nephrectomy, 2 radical nephrectomies, 56 partial nephrectomies, 12 nephroureterectomies, and 2 adrenalectomies. Excluding simple and radical nephrectomies, in most cases, an extra-incisional 12-mm trocar was placed. Mean warm ischemia time for partial nephrectomy decreased to 26 minutes and, furthermore, they report that their transfusion rate decreased to 13%. Complications included renal vein injury, ureter injury, postoperative bleeding, and two cases of focal positive margins—all of which indicate the complexity of the procedure and the necessity for an advanced laparoscopic and robotic skill set before embarking on these cases.

Benefits of the da Vinci Surgical System for LESS include easier articulation, three-dimensional vision, motion scaling, and tremor filtration. Disadvantages include the requirement of a longer incision to avoid clashing. With the current robotic platform, collision of instruments and arms remains problematic and may result in unexpected intracorporeal movement of the instruments. ¹¹ Furthermore, while the 5-mm robotic instruments deflect, thus increasing triangulation, they do not articulate and thus render suturing more difficult. A robot built for single-site surgery, the VeSPA (Intuitive Surgical, Sunnyvale, CA) has undergone trials, with radical nephrectomy, pyeloplasty, and partial nephrectomy being completed in a porcine model. ¹² While instrument clashing was reduced, loss of distal tip articulation caused intracorporeal suturing to be challenging.

In the current study, we present a large experience with RLESS kidney surgery showcasing the wide variety of procedures that can be performed. Perceived advantages over standard LESS include improved ergonomics, greater precision, and enhanced ability to approach more complex procedures with single-site technique. Ongoing improvements, including the development of flexible and in vivo robots will overcome the limitations of current RLESS procedures.

In line with many advances progressing from benchtop to the clinic, experience with robot-assisted single port kidney surgery began in the laboratory. ^11,13 These studies allowed clinicians to become accustomed to the challenges associated with RLESS, and it is recommended that before embarking on a clinical RLESS program, experience in the laboratory be obtained. To define objective benefits over standard LESS and robotic techniques and to ultimately characterize the role of RLESS compared with other minimally invasive modalities, however, randomized controlled trials are needed.