Partial nephrectomy

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.

Preoperative assessment

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.