How has the indication spectrum for Minimally Invasive Surgery (MIS) liver resections evolved?

Evolution of Indication Spectrum for Minimally Invasive Surgery (MIS) Liver Resections

Minimally invasive surgery for liver resections has evolved from being limited to small peripheral tumors to becoming the preferred approach for most liver resections due to improved perioperative outcomes without compromising oncological results.

Historical Development of MIS Liver Resections

The evolution of minimally invasive liver surgery has progressed through several distinct phases:

Initial Limitations (Pre-2008)

• Early MIS liver resections were limited to highly selected cases
• In 2008, consensus recommendations restricted MIS to:
  • Tumors <5 cm in size
  • Lesions located in anterior segments (segments 2-6) 1
  • Primarily minor resections and left lateral sectionectomies

Expansion Phase (2008-2016)

• Gradual expansion of indications as surgical expertise and technology improved
• The 2016 ERAS Society guidelines acknowledged that laparoscopic liver resections (LLR) had become standard practice for minor resections 1
• Major hepatectomies were still considered "innovative procedures" requiring further investigation 1

Current Status (2016-Present)

• MIS has become the preferred approach for most liver resections
• The 2023-2025 guidelines strongly recommend MIS for liver resections, particularly for small tumors in favorable locations 1
• Indications have expanded to include:
  • Major hepatectomies
  • Complex resections
  • Patients with portal hypertension
  • Cirrhotic patients with HCC

Benefits of MIS Liver Resections

Perioperative Advantages

• Reduced perioperative morbidity 1
• Decreased blood loss 1, 2
• Shorter hospital stays 1, 3
• Lower perioperative mortality 1
• Reduced postoperative pain 1
• Quicker recovery times 1
• Shorter ICU stays 3
• Lower inflammatory response 1

Oncological Outcomes

• Comparable or slightly superior long-term survival compared to open surgery 1, 2
• Similar R0 resection rates 2
• No compromise in cancer-specific outcomes 1
• Potentially reduced risk of perioperative tumor cell engraftment due to lower inflammatory response 1

Current Indication Spectrum

Tumor Characteristics

• Now includes tumors of various sizes (no longer limited to <5cm)
• Location has expanded beyond segments 2-6 to include:
  • Posterior segments
  • Centrally located tumors
  • Tumors near major vascular structures (with appropriate expertise)

Extent of Resection

• Minor resections (≤2 segments): Firmly established as standard of care 1
• Major hepatectomies: Now routinely performed at experienced centers 1, 3
• Complex procedures including:
  • Anatomical segmental resections
  • Staged hepatectomies for liver metastases 1

Patient Populations

• Expanded to include:
  • Elderly patients 1
  • Patients with cirrhosis and HCC 4
  • Patients with portal hypertension 5
  • Living liver donors 1

Disease Indications

• Hepatocellular carcinoma (HCC) 1, 5, 4
• Intrahepatic cholangiocarcinoma (iCCA) 1
• Colorectal liver metastases 2
• Benign liver lesions 1

Technical Considerations

Approaches

• Laparoscopic: Most common MIS approach 1
• Robotic: Emerging approach with potential benefits 6
  • No definitive advantage over laparoscopic approach has been established 1
  • Choice should be based on availability and surgical expertise 1

Anatomical Considerations

• Advanced techniques have overcome previous limitations:
  • Dye-guided techniques 1
  • 3D reconstruction 1
  • Navigation-assisted approaches 1

Pitfalls and Caveats

Technical Challenges

• Longer operative time, especially for major resections 1
• Learning curve for surgeons transitioning from open to MIS
• Conversion rate to open surgery remains significant (30.9% in one study) 3

Patient Selection

• Not all patients are suitable candidates for MIS
• Complex cases should be approached by experienced surgeons in high-volume centers
• Conversion to open should not be considered a failure but a prudent decision when needed

Resource Considerations

• Regional variations in healthcare infrastructure affect MIS adoption 1
• Advanced healthcare systems may favor surgical interventions due to better access to technology and specialists 1

Future Directions

• Robotic liver surgery is expected to expand the indications further 6
• Integration with neoadjuvant and adjuvant therapies
• Potential for MIS approaches in patients previously considered unsuitable for resection
• Hierarchical treatment approach placing MIS above open surgery and second only to liver transplantation 4

In conclusion, the indication spectrum for MIS liver resections has dramatically evolved from highly selective cases to becoming the preferred approach for most liver resections. This evolution has been driven by improved surgical techniques, technological advancements, and accumulating evidence demonstrating the safety and efficacy of MIS approaches without compromising oncological outcomes.