Partial nephrectomy is now considered the treatment of choice in all small renal tumors when technically feasible, because long-term oncologic outcomes are equivalent to radical nephrectomy while preserving renal function. Despite its oncologic safety, laparoscopic partial nephrectomy (LPN) is still considered a technically challenging procedure with a prolonged learning curve. Robotic-assisted partial nephrectomy (RAPN) has progressed as a technique that attempts to address the technical challenges of pure LPN, while offering the benefits of the minimally invasive approach. The three-dimensional (3D) view and wristed instruments enable significantly greater precision in resecting and suturing even complex tumors. In experienced hands, all but the most complex partial nephrectomies can be performed robotically without using open techniques.
Access, pneumoperitoneum, and port placement
Bowel mobilization and identification of ureter and gonadal vessels
Access, balloon dilation of retroperitoneal space, and port placement
Incision of posterior layer of Gerota fascia and anterior mobilization of kidney
Identification of natural plane between perinephric and perihilar fat
Hilar dissection and isolation of renal artery(ies) with vessel loops
Removal of perinephric fat for 1 to 2 cm around tumor
Ultrasound confirmation of margins, shape and depth of tumor with scoring of margin on capsule
Preclamp “time out”
Clamping of renal artery (and vein when required); ischemic time started
Hemostatic deep layer (followed by early unclamp) OR
Sliding clip renorrhaphy
Unclamp and oversew briskly bleeding vessels
Tumor placed in retrieval bag, drain placed, vessel loops and ports removed, and closure
Indications and contraindications for robot-assisted partial nephrectomy
The indications for RAPN have expanded over the years to include larger, more central, endophytic, and complex tumors. Accordingly, the indications for an open partial nephrectomy (OPN) apply to the robotic approach in experienced hands.
Indications can be classified as absolute, relative, or elective ( Table 19.1 ). Similarly, contraindications of this modality relate to both NSS and the minimally invasive components. To date, contraindications include radiologic T3 disease (i.e., invasion of other organs, or renal vein or inferior vena cava [IVC] thrombi in the presence of a normal contralateral kidney).
Relative contraindications include a limited life expectancy and normal contralateral kidney and musculoskeletal deformity/contractures that prevent proper positioning. Other relative contraindications include severe cardiopulmonary disease, uncontrolled coagulopathy or hepatic disease, recent cerebrovascular or cardiovascular accident, and recent deep venous thrombus.
All patients should undergo a high-fidelity, narrow slice (2-mm) contrast-enhanced computed tomography (CT) of the chest, abdomen, and pelvis for full staging, to exclude metastases or locally advanced disease.
The abdominal imaging should include reconstructed series to clearly define the tumor and renal vasculature, including the number and course of renal vessels and the tumor size, anatomy, position, and proximity to the collecting system. Detailed preoperative imaging is crucial and will help to determine if the tumor is amenable to a nephron-sparing and or/minimally invasive approach. It is now possible to create a 3D-printed or virtual image of the kidney including tumor anatomy, renal vasculature, and collecting system detail to plan robotic partial nephrectomy. Magnetic resonance imaging (MRI) may be indicated if more detailed evaluation of venous involvement or a reduction in radiation is required or to avoid intravenous CT contrast medium. The role of renal tumor biopsy is still controversial. To date, current guidelines do not recommend routine tumor biopsy prior to curative surgery, , although this is becoming increasingly popular in circumstances where surgery is technically challenging and/or the patient has significant comorbidity. Anticoagulants should be discontinued before surgery when feasible.
Nephrometry scoring systems
A number of scoring systems to assess tumor complexity have been derived over recent years. These are based on factors including tumor size, endophytic or exophytic nature, involvement of the renal sinus or collecting system, and lateral or medial position. They allow surgeons to predict case difficulty and potential complications, but each has its limitations. The most popular and established are the RENAL and PADUA scores, which can be divided into low-, intermediate-, and high-complexity tumors.
Theater and port setup
See the box that follows for special equipment required and Fig. 19.1 for the operating room setup.
Fenestrated bipolar forceps
Large needle holders ×2
Deep layer: 1 or 2 18/20-cm 3-0 Monocryl suture with Hem-o-lok applied (or 3 × 15 cm 3/0 V-Loc with Hem-o-lok applied)
“Rescue sutures”: 4/0 polyglactin, 12 cm and 20 cm; 2/0 polyglactin 20 cm
Superficial renorrhaphy: 4 or 5 × 0 polyglactin 12 cm with Hem-o-lok applied
Drop-in or laparoscopic ultrasound probe
Robotic or laparoscopic bulldog clamps
AirSeal insufflator, particularly for retroperitoneal cases
Laparoscopic scissors, suction device, graspers, Hem-o-lok clip appliers
Patient preparation and positioning
After induction of general anesthesia, a Foley catheter is placed prior to positioning the patient in a modified lateral decubitus position at approximately 45 degrees or full flank. For transperitoneal access, the patient is positioned with the anterior abdomen at the edge of the table to allow for unrestricted robotic arm movement, whereas for retroperitoneal access, the patient is positioned with the back to the edge of the table. All pressure points are carefully padded, and the patient is secured to the operating table at the level of the lower rib cage and/or hips using a designated belt or tape. The upper arm can be placed in a gutter frame or in a “sleeping baby” position, but care needs to be taken to allow adequate room for movement of the robotic arms when mobilizing the most inferior extent of the colon. The surgical table is flexed and positioned in a slight Trendelenburg position. Forced-air patient warming is applied (such as “Bair Hugger”). Shaving, skin preparation, and draping are performed as usual.
Stages of the procedure
Port placement and robot docking: Transperitoneal approach
The camera port is placed approximately three fingerbreadths below the costal margin in the midclavicular line with open Hasson technique, and the abdomen is insufflated to 12 to 15 mm Hg according to surgeon preference. Due to expansion of the abdomen, once pneumoperitoneum is achieved, there will be a handbreadth of space cranial to the camera port to place an 8-mm Xi port just under the costal margin. The two additional 8-mm robotic working ports are placed under direct vision along a curvilinear line along the midclavicular line arcing gently laterally for the inferior-most port, with each port approximately one handbreadth apart. A 12-mm (or 15-mm AirSeal) assistant port is placed approximately one handbreadth medial to the robotic ports, bisecting either the superior two robotic ports, or the middle two robotic ports according to surgeon preference. An additional 5-mm port can be placed in the subxiphoid area to retract the liver on the right side or act as an additional assistant port ( Fig. 19.2 ). The robot is docked perpendicular to the patient from the posterior aspect.