What is the preferred surgical approach for central tumors, robotic partial nephrectomy (RPN) or laparoscopic partial nephrectomy (LPN)?

Robotic vs Laparoscopic Partial Nephrectomy for Central Tumors

For central renal tumors, robot-assisted partial nephrectomy (RAPN) is preferred over laparoscopic partial nephrectomy (LPN) due to significantly shorter warm ischemia times and lower risk of conversion to radical nephrectomy, particularly for complex hilar lesions. 1, 2

Comparative Advantages of RAPN for Central Tumors

• RAPN provides equivalent perioperative outcomes to LPN but with significantly shorter warm ischemia time, which is crucial for preserving renal function 1, 3
• For complex central tumors, RAPN has a significantly lower risk of conversion to radical nephrectomy (1% vs 11.5%) compared to LPN 2
• RAPN appears less affected by tumor complexity than LPN regarding operative parameters such as blood loss and operative time 3
• RAPN demonstrates better access and maneuverability for suturing in the confined space around hilar structures due to articulated robotic instruments 2, 4

Surgical Considerations for Central Tumors

• Central tumors, particularly hilar tumors, pose additional technical challenges due to proximity to major vessels and collecting system 4
• Warm ischemia time is longer for hilar tumors compared to peripheral tumors (26.3 min vs 19.6 min), but RAPN still achieves better ischemia times than LPN for these complex cases 4, 3
• Nephrometry scoring systems (R.E.N.A.L., PADUA) should be used to assess tumor complexity and guide surgical approach selection 1
• For central tumors with high nephrometry scores, RAPN offers better technical feasibility than LPN 2, 4

Patient Selection Algorithm

• For small central tumors (≤4 cm) with low-to-intermediate complexity: Either RAPN or LPN may be appropriate, with RAPN preferred when available 1
• For larger central tumors (>4 cm) or those with high complexity scores: RAPN is strongly preferred over LPN 2, 4
• For hilar tumors involving the renal sinus or in close proximity to major vessels: RAPN offers significant advantages over LPN 4
• For extremely complex central tumors not amenable to minimally invasive approaches: Consider open partial nephrectomy 1

Technical Considerations

• Transperitoneal approach is generally preferred for central tumors due to larger working space and better angles for suturing 1
• Retroperitoneal approach may be considered for selected posterior central tumors 1
• Careful preoperative planning using 3D imaging is essential to map the vascular anatomy and plan the resection strategy 1
• Experienced robotic surgeons can safely perform RAPN even for highly complex central tumors with acceptable outcomes 5, 6

Outcomes and Complications

• Both RAPN and LPN have similar oncological outcomes with comparable positive surgical margin rates 3, 2
• RAPN is associated with less intraoperative blood loss compared to LPN 3
• Complication rates are similar between RAPN and LPN, though RAPN may offer advantages in reducing hospital stay 3
• Preservation of renal function is better with RAPN due to shorter warm ischemia times, which is particularly important for central tumors requiring complex reconstruction 3, 2

Caveats and Pitfalls

• Surgeon experience significantly impacts outcomes for both approaches, particularly for complex central tumors 1
• The learning curve for RAPN is generally shorter than for LPN, especially for complex cases 3
• Conversion to radical nephrectomy should be considered when partial nephrectomy cannot be safely completed, particularly with LPN 2
• Warm ischemia time should ideally be kept under 30 minutes to preserve renal function, which is more consistently achievable with RAPN for central tumors 1, 3