Partial Nephrectomy

Partial nephrectomy (nephron-sparing surgery) removes a renal tumour while preserving the rest of the kidney, and is the treatment of choice for most localized renal masses — oncologically equivalent to radical nephrectomy for cT1 disease with better long-term renal function and lower cardiovascular morbidity. It can be performed open, laparoscopically, or robotically; the robotic platform's wristed instruments ease the tumour excision and renorrhaphy and have made it the dominant minimally invasive approach. The management context (staging, partial-vs-radical selection, surveillance) is covered in the Kidney Cancer topic, and the en-bloc operation on the Radical Nephrectomy page; this page is the operative reference.

Indications

• Any cT1a mass, and feasible cT1b (≤ 7 cm) when partial resection with a negative margin is technically achievable — partial is preferred over radical for any feasible cT1.
• Imperative (absolute) indications: a solitary kidney, bilateral tumours, or a familial RCC syndrome.
• Relative indications: baseline CKD or proteinuria, a young patient, or multifocal disease.
• Tumour size is not, in itself, a reason to forgo partial nephrectomy — selected cT2 masses are resected in expert hands.
• The RENAL nephrometry score (Radius, Exophytic/endophytic, Nearness to the collecting system, Anterior/posterior, Location relative to the polar line; 4–12) grades surgical complexity — lower scores are more amenable to partial nephrectomy.

Contraindications

• Tumour factors: hilar encasement, central collecting-system invasion, tumour thrombus, or adjacent-organ invasion — anatomy that precludes a safe negative-margin resection.
• Technical factors: an anticipated ischaemia time > 45 minutes (consider an open approach with cold ischaemia, or radical nephrectomy).
• Patient factors: < 10–20% retained function in the affected kidney, a strong patient preference against nephron-sparing surgery, or a performance status that precludes the procedure.
• Consider radical nephrectomy instead when cold ischaemia would exceed 45 minutes, < 20% functional nephron would remain, the tumour is highly complex, or there is nodal involvement.

Preoperative Workup

• Imaging: a multiphase CT angiogram or MRI to define the tumour's relation to the vessels and collecting system, and to identify aberrant or multiple vessels before surgery.
• Urine: dipstick, urinalysis, and culture to exclude an active UTI.
• Antibiotics (per AUA): a first- or second-generation cephalosporin.
• Thromboprophylaxis: 5000 units of subcutaneous heparin with sequential compression devices.
• Consent must include conversion to an open approach and to total (radical) nephrectomy for uncontrolled bleeding or unresectable anatomy.
• For urothelial carcinoma of the collecting system, evaluate multifocality with ureterorenoscopy (the tumour should ideally be unifocal and polar) and strongly consider neoadjuvant chemotherapy.

Renal Ischaemia and Function

The number of preserved nephrons is the primary determinant of post-operative function, and a negative margin is the goal — margin width does not matter.

• Warm ischaemia should be as short as possible — aim for < 25 minutes (Hinman's open technique targets < 20 minutes, though several series show no compromise up to ~40 minutes).
• Cold ischaemia is more forgiving — targeted under ~35 minutes, with hypothermia tolerated up to ~60–90 minutes; use ice slush when ischaemia is expected to exceed ~20 minutes.
• Hyperfiltration injury: diverting renal blood flow to fewer nephrons raises single-nephron GFR and, when total nephron mass (both kidneys) falls by > 80%, drives focal segmental glomerulosclerosis with proteinuria and progressive renal failure — treat with an ACE inhibitor and a low-protein diet (proteinuria appears first).
• Mannitol: IV mannitol (12.5 g) with furosemide (40 mg) 5–10 minutes before clamping is the traditional open-technique adjunct, but a 285-patient review found no renal-function benefit, and many no longer use it routinely.

Clamping Strategy

The hilum is fully dissected so that bulldog clamps or a Satinsky can be applied to each vessel (note any accessory vessels on imaging first).

• Individual artery + vein clamping is preferred on the right (higher venous pressure and back-bleeding risk with en-bloc control); on the left, clamping the artery alone is often enough for a bloodless field.
• En-bloc hilar clamping with a Satinsky suits multiple vessels, a venous plexus, or a fibrotic hilum — but needs an extra 12-mm assistant port.
• Selective / super-selective clamping (a segmental artery, demarcated by injecting indigo carmine into the clamped vessel to mark the ischaemic line) preserves perfusion to unaffected parenchyma and is useful for a solitary kidney.
• Off-clamp resection is reserved for small peripheral lesions (still dissect the hilum for rescue control), keeping warm ischaemia under ~20–30 minutes.
• If perfusion persists on clamp, check imaging for a missed vessel or incomplete occlusion (clamp the vein if unclamped; unclamp the vein if it is causing venous congestion from a missed artery).

Open Partial Nephrectomy

The kidney is approached extraperitoneally through a flank incision in the 10th or 11th intercostal space (or transperitoneally for very large tumours). Dissect the kidney free of perirenal fat — leaving fat over a palpable tumour — control the pedicle with vessel loops, and have renal cooling and Nu-Knit bolsters/pledgets ready before a "time-out". The resection technique scales with tumour size and depth:

Enucleation (small cortical tumours)

Score the cortex with cautery, find the plane outside the tumour pseudocapsule within normal parenchyma, and bluntly dissect it out — ischaemia is often unnecessary. Control bleeders with figure-of-eight 4-0 or 5-0 absorbable monofilament, close any collecting-system entry, lay a Nu-Knit pledget and bolster in the crater, and close with a 2-0 horizontal mattress on a large tapered ½-circle needle (suturing through the pledgets 1–2 cm from the ridge). Unclamp as soon as the crater collapses; leave a closed-suction drain and a Foley.

Wedge resection (large cortical tumours)

Clamp the renal artery with a bulldog (ice slush if ischaemia will exceed ~20 minutes) and incise the capsule 5 mm peripheral to the tumour, excising a rim of normal parenchyma. Test the collecting system by injecting 10 mL of dilute indigo carmine into the pelvis while occluding the ureter, close it with 4-0/5-0, then reconstruct over 5-cm bolsters and pledgets.

Segmental nephrectomy (large polar tumours)

Dissect the hilum to the segmental branches, clamp the apical or basilar segmental artery, and mark the demarcated ischaemic line; clamp the pedicle en bloc with a Satinsky and cool with ice slush. After excising the pole, place a 6-Fr double-J stent for a large collecting-system injury, close with running 4-0/5-0, and repair the capsule over pledgets with a larger needle; consider nephropexy if the kidney is mobile.

Heminephrectomy (large tumours)

For a non-functional duplex upper pole, polar urothelial carcinoma, or a large polar tumour beyond segmental limits — place a double-J stent before incision, clamp the renal artery with cooling, resect, and close the collecting system and capsular defect over pledgets.

Laparoscopic / Robotic Partial Nephrectomy

Positioning and Access

A modified flank position with a ~30-degree bump, the bed kept non-flexed (kidney rest down) unless elevation is needed. A transperitoneal approach is preferred for most tumours (more room, better visualisation); retroperitoneal is reserved for posterior tumours or prior abdominal surgery in experienced hands. For endophytic or larger tumours, place a 5-Fr ureteral catheter (with a methylene-blue syringe attached) to test the collecting-system repair, plus a Foley. Insufflate with a Veress needle and place the camera and two robotic arms in a triangular configuration with a 12-mm assistant port in the low midline; a 3-mm retractor lifts the liver (right) or spleen (left).

Dissection and Ultrasound

Mobilise the colon and kidney as for nephrectomy; "sticky fat" is dissected directly onto the capsule away from the tumour to avoid violating it. Intraoperative ultrasound demarcates the resection extent and is essential for a deep endophytic tumour — "picture-in-picture" and "Firefly" near-infrared imaging help map the tumour to the vascular and collecting-system anatomy.

Excision and Renorrhaphy

Score the parenchyma with monopolar scissors before clamping. Excise by enucleation, wedge, or a combination — the EAU supports a minimal normal-parenchyma margin, and enucleation gives similar oncologic outcomes (except for Fuhrman grade 4 tumours), which helps for deep tumours. Repair the collecting system and disrupted vessels with precut 4-0 Vicryl secured with a Lapra-Ty (kept out of the resection bed, where it can erode), confirming the repair with a methylene-blue injection. Perform the parenchymal renorrhaphy with precut 2-0 Vicryl (sliding-clip / V-Loc) over an optional haemostatic bolster, covering a large defect with a flap of Gerota's fat. Place the specimen in an entrapment sac through a port lengthened to fit (an undersized site risks tumour rupture), and leave a Blake drain near — not over — the renorrhaphy.

Postoperative Care

• Clear liquids on POD 1, early ambulation with incentive spirometry, advancing to a regular diet after flatus.
• The Foley is removed on POD 1 (POD 2 with a stent, an extensive collecting-system closure, or a man with prior obstructive voiding symptoms).
• The drain is removed before discharge once a drain creatinine confirms no urine leak — but consider keeping it 7–10 days after a large open partial (most leaks appear at 1–2 weeks).
• Discharge when pain is controlled orally, the patient is tolerating diet, ambulating, and clinically stable.

Complications

• Urine leak (clinically significant in 1–5%, higher with deep endophytic tumours, larger size, or high blood loss) — manage with a ureteral stent and/or a percutaneous drain; an established leak needs "three tubes" (a perinephric drain, a double-J stent, and a Foley) to keep the system low-pressure; reoperation is rarely required.
• Bleeding — early bleeding is usually from the surgical site and managed conservatively; delayed bleeding is typically a renal pseudoaneurysm (up to several weeks out) treated by IR coiling; > 2 units of transfusion signals serious bleeding warranting angioembolization, and life-threatening haemorrhage may require angioinfarction or nephrectomy. Counsel the patient to return for gross haematuria, worsening flank pain, tachycardia, or blood-pressure changes.
• Positive surgical margin — most microscopic foci are prognostically insignificant, but a grossly positive margin may require salvage nephrectomy, performed promptly before perirenal adhesions form.
• Renal insufficiency — most likely in a solitary kidney; usually transient (occasionally needing temporary dialysis); hyperfiltration injury causes gradual, proteinuria-associated decline.
• Neuromuscular injury — positioning-related; pain out of proportion in a pressure area should raise rhabdomyolysis/compartment syndrome (more common in large, muscular patients and long cases) needing orthopaedic compartment-pressure evaluation.
• Visceral injury — on the left, pancreatic injury/pancreatitis (rising serum or drain amylase); bowel injury can present early or late.
• Local recurrence after partial or radical nephrectomy is 2–4% (poor prognosis), curable in 30–40% with surgery or ablation.