Robotic Partial Nephrectomy- Each Kidney Counts

Mar 21 , 2023 | 3 min read

The incidence of renal tumours has been increasing over the past several decades, and renal cell carcinoma is projected to remain a major uro-oncological health burden. Due to the increased availability and utilisation of Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), more renal masses are being diagnosed.

Incidentally detected renal masses currently comprise 48% to 66% of tumours, compared with only 3% to 13% in the 1970s. While open radical nephrectomy (removal of the whole gland) has been the gold standard for any renal tumour surgery in the past, partial nephrectomy has now become a standard of care for clinically localised renal masses. In partial nephrectomy, we remove the tumour with one cm of the kidney tissue margin only and save the functioning kidney.

Two decades earlier, Partial nephrectomy (PN) was seen as unnecessary when a normal contralateral kidney was present. Some of such patients had progressed to chronic kidney failure even though there was no recurrence of tumours in the body. The indications for partial nephrectomy have been expanded over the years.

Indications have changed from individuals with imperative indications (e.g. solitary kidney, bilateral tumours or high renal insufficiency risk) to all individuals with renal masses less than 4 cm in diameter. Today, guidelines recommend partial nephrectomy whenever technically feasible, independent of tumour size. The adoption of robotic-assisted surgery has added to the increased utilisation of partial nephrectomy.

The most important radical nephrectomy (RN) related comorbidity is renal insufficiency. Partial nephrectomy preserves the part of the kidney uninvolved by the tumour at the time of surgical treatment. There is increasing concern that surgically induced CKD (Chronic Kidney Disease) will be associated with an increased risk of hospitalisation, cardiovascular events, and death, as has been shown in CKD from all causes.

Furthermore, CKD is independently associated with postoperative death and cardiovascular events in patients undergoing elective noncardiac surgery. Consequently, partial nephrectomy has been increasingly adopted to minimise surgically induced CKD and is now considered a standard surgical approach for early-stage kidney cancer.

A detailed understanding of surgical anatomy is necessary to optimise preoperative planning and operative technique, thus providing a basis for maximising oncologic and functional outcomes. Imaging must delineate the relationship of the mass to adjacent normal structures and demonstrate the vascularity of the tumour. Triphasic contrast-enhanced CT of the abdomen is the preferred investigation for primary imaging and staging.

Multiple factors impact renal functional outcomes after PN, including preoperative renal function, comorbidity, age, gender, tumour size, percentage volume preservation, and ischemia time.

Overall, the two surgically relevant principles for optimising post-PN functional outcomes are to maximise volume preservation and minimise ischemia. The volume of parenchyma preserved is potentially more important than short-duration ischemia time, especially in healthy patients with normal function at baseline.

There is no agreement on the precise cut-off time for the onset of durable renal damage during warm ischemia.

There have been some doubts regarding local tumour control, but data from non randomised observational studies indicate similar oncologic outcomes compared to RN in appropriately selected patients.

Progression of surgical treatment has moved from open partial nephrectomy (OPN) to laparoscopic partial nephrectomy (LPN) and, most recently, robot-assisted (RAPN). LPN has been deemed equally effective as OPN in terms of long-term oncological and functional outcomes.

The main deterrent that has hindered the widespread adoption of LPN is the technically demanding nature of the procedure, 2D vision and limited degree of freedom for movements of laparoscopic instruments. As a result, RAPN has proven to be a more precise and favoured technique in recent years.

The robotic ultrasound probe can be used in order to delineate precise tumour borders for dissection. Another emerging advancement is the use of near-infrared fluorescence imaging.

Tissues receiving blood flow will turn fluorescent green, while the ischemic tumour (and collateral tissue) will appear pale. This helps in saving functioning kidney tissue.

Over the past decade, Robotic PN surgery has been evolving as a preferred minimally invasive procedure for the most complex tumours. Innovation continues to make RAPN an attractive technology to provide superb care for patients with renal tumours. It safely removes the tumour and saves kidney function.