Robotic partial nephrectomy

Why preserve kidney

Whenever feasible, modern urological oncology prefers partial nephrectomy over complete removal of the kidney for small renal masses. The reason is that chronic kidney disease is an independent risk factor for cardiovascular disease and overall mortality, and every millimetre of healthy nephron retained matters for long-term renal function. Published series show equivalent cancer control for appropriately selected tumours (broadly cT1 disease), with preserved kidney function compared with radical nephrectomy.⁷

Who it suits

• Small renal masses up to about 7 cm that are anatomically accessible (cT1 disease).
• Larger or more complex tumours in selected cases, including solitary kidney, bilateral tumours, or pre-existing chronic kidney disease.
• Patients fit for a general anaesthetic and a pneumoperitoneum.

Tumours that cannot safely be resected with a clear margin - for example, deeply hilar or very large and infiltrative tumours - may be better served by radical nephrectomy.

What the operation involves

1. Positioning in a modified flank position; ports placed; robot docked.
2. Access to the kidney through the peritoneum or retroperitoneum (case-specific).
3. Identification of the renal artery and vein at the hilum.
4. Intra-operative ultrasound to confirm tumour margins and plan the resection.
5. Warm ischaemia: the renal artery is temporarily clamped. The tumour is excised with a thin rim of healthy parenchyma. The remaining kidney is reconstructed in two layers (the medullary collecting system first, then the outer cortex) and the clamp is released. Target warm ischaemia time is usually under 25 minutes.
6. Specimen placed in a bag and removed through one of the port incisions.
7. Drain placement and port closure.

Warm ischaemia time

Warm ischaemia time - the period the kidney is without blood flow during tumour excision and reconstruction - is the strongest intra-operative predictor of long-term function of that kidney. Reducing it depends on surgeon experience, tumour complexity and preparation before clamping. Robotic access supports faster, more precise reconstruction, which is one of the reasons this operation migrated from laparoscopic to robotic in most centres over the last decade.

Hospital stay

Typical hospital stay is two to three nights. A drain and catheter are usually removed before discharge. Most people return to desk-based work in two to three weeks and to heavier activity at six weeks.

Expected outcomes

• Oncologic control for cT1 disease is equivalent to radical nephrectomy in published series.⁷
• Long-term renal function is better preserved than after radical nephrectomy.
• Blood loss, transfusion rate and length of stay are lower than equivalent open partial nephrectomy.⁴

Potential complications

• Bleeding during or after surgery, occasionally requiring transfusion, rarely requiring re-intervention or conversion to open nephrectomy.
• Urinary leak from the reconstructed collecting system (usually resolves with drainage and/or a ureteric stent).
• Reduced long-term function of the treated kidney, usually of minor consequence if the other kidney is normal.
• Positive surgical margin on final pathology (uncommon when intra-operative ultrasound and careful margin planning are used).
• Standard risks of abdominal surgery (infection, venous thromboembolism, anaesthetic risk).

Alternatives

• Active surveillance for small, indolent masses in older or co-morbid patients.
• Ablation (cryoablation or radiofrequency ablation) in selected small tumours.
• Radical nephrectomy when partial resection is not feasible.

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