What are the surgical steps of a partial nephrectomy?

Surgical Steps of Partial Nephrectomy

The surgical steps of partial nephrectomy involve tumor removal while preserving maximum healthy renal parenchyma, with the approach varying based on tumor location, size, and surgeon expertise. 1

Preoperative Assessment and Planning

• Evaluate tumor complexity using nephrometry scoring systems (R.E.N.A.L. or PADUA) to predict surgical difficulty and guide approach 1
• Consider tumor characteristics:
  • Size (ideally ≤7 cm)
  • Location (anterior/posterior, polar position, rim location)
  • Depth of parenchymal invasion
  • Proximity to collecting system
  • Relationship to renal vasculature

Surgical Approach Selection

• Open Partial Nephrectomy (OPN): Preferred for complex tumors, particularly those with high nephrometry scores 1
• Laparoscopic Partial Nephrectomy (LPN): Best for small tumors (≤4 cm) with low/intermediate complexity 1
• Robot-Assisted Partial Nephrectomy (RAPN): Offers advantages of shorter warm ischemia time compared to LPN 1

Access Route Determination

• Transperitoneal approach: Preferred for anterior tumors, larger tumors, and deeply infiltrating lesions requiring heminephrectomy 1
• Retroperitoneal approach: Better for posterior tumors, especially posteromedial lesions 1

Intraoperative Steps

1. Patient Positioning

   • Flank position with table flexed and kidney rest elevated 2
   • For open surgery: horizontal flank incision, sometimes with lower rib resection 2
   • For laparoscopic/robotic: strategic port placement based on approach

2. Kidney Mobilization

   • Complete mobilization of kidney within Gerota's fascia
   • Identification and isolation of renal hilum
   • Careful dissection to expose tumor surface while preserving perirenal fat over normal parenchyma

3. Vascular Control

   • Temporary clamping of renal artery (and sometimes vein) to achieve a bloodless field
   • Options include:
     • Satinsky clamp for en bloc hilar control
     • Bulldog clamps for selective arterial clamping
   • Goal: Minimize warm ischemia time (ideally <30 minutes) 1

4. Tumor Excision

   • Demarcation of surgical margin (typically 5mm from tumor edge)
   • Sharp excision of tumor with surrounding margin of normal parenchyma
   • Options include:
     • Simple enucleation (sparing healthy parenchyma)
     • Enucleoresection (removing thin layer of healthy tissue)
     • Polar/wedge resection (wider excision) 1
   • Intraoperative ultrasound may guide resection margins
   • Collection system repair if entered (with absorbable sutures)

5. Hemostasis and Reconstruction

   • Identification and suture ligation of visible transected vessels
   • Repair of collecting system if entered
   • Hemostatic agents application (fibrin sealants, hemostatic matrix)
   • Renorrhaphy (closure of parenchymal defect):
     • Deep sutures to approximate medullary tissue
     • Capsular sutures to close outer defect
     • Often using sliding-clip technique over bolsters

6. Unclamping and Final Hemostasis

   • Release vascular clamps
   • Check for bleeding and repair as needed
   • Place drain if collecting system was entered

7. Specimen Management

   • Immediate examination for gross margins
   • Proper orientation and handling for pathology

Postoperative Care

• Monitor for common complications:
  • Hemorrhage (1-2%)
  • Urinary leakage (3-4%)
  • Perirenal hematoma 1
• Drain management if placed (typically 3-5 days if collecting system was entered)
• Renal function monitoring

Technical Pearls and Pitfalls

• Critical Timing: Minimize warm ischemia time to <30 minutes to preserve renal function 1
• Margin Control: Ensure negative surgical margins while preserving maximum functional parenchyma 1
• Complex Locations: Upper pole tumors require complete mobilization and rotation for adequate access 1
• Approach Selection: Transperitoneal approach offers larger working space and better suturing angles but may be challenging for posterior tumors 1
• Conversion Awareness: Be prepared to convert to radical nephrectomy if tumor control cannot be achieved safely (1-2% of cases) 1

Partial nephrectomy outcomes are optimized when the surgical approach is tailored to tumor characteristics, with the primary goal being complete tumor removal while maximizing preservation of functioning renal tissue.