Anterior Approach for Liver Resections
Executive Summary
The anterior approach for liver resection is a specialized "no-touch" surgical technique designed primarily for the removal of large liver tumors, particularly those where the standard rotation of the right liver is contraindicated. By avoiding manual compression and rotation of the liver, the procedure minimizes the risk of iatrogenic tumor rupture and the shedding of malignant cells into the circulatory system, potentially improving patient survival.
Key technical components include the use of intraoperative ultrasonography (IOUS) for resectability assessment, the Cavitron Ultrasonic Surgical Aspirator (CUSA) for precise parenchymal transection, and the maintenance of low central venous pressure to minimize blood loss. The procedure follows a methodical sequence of hilar dissection, parenchymal transection along the Cantlie line, and final vascular division, ensuring the viability of the remnant liver throughout the operation.
Rationale and Clinical Advantages
The anterior approach is necessitated by clinical scenarios where large tumors prevent the safe rotation of the right liver to the left. The primary advantages of this method include:
Oncological Integrity: By utilizing a no-touch technique, surgeons avoid compressing the tumor, which reduces the risk of iatrogenic rupture and the dissemination of tumor cells.
Vascular Protection: Conventional rotation can compromise the inflow and outflow of the remnant liver; the anterior approach maintains stable vascular positioning.
Applicability: While most commonly described for right hepatectomy, the technique is also applicable to left hepatectomy.
Procedural Methodology
The procedure is executed through a sequence of eight primary steps, focusing on exposure, assessment, and systematic vascular control.
Step 1: Surgical Access
Incision: A right subcostal incision with an upward midline extension is utilized.
Exposure: The round ligament is divided between ligatures, followed by the division of the falciform ligament. A Bookwalter retractor is employed to provide optimal exposure of the liver.
Malignancy Check: A laparotomy is performed to identify any extrahepatic malignancies.
Step 2: Assessment of Resectability
Ultrasonography (IOUS): IOUS is critical to delineate tumor extent, identify multiple nodules, and exclude tumors in the left liver.
Vascular Mapping: The procedure identifies tumor involvement of the main or left portal vein and uses Doppler ultrasonography to register the flow and pulsatility of vessels in the future remnant liver.
Step 3: Vascular Isolation (Right Portal Vein and Hepatic Artery)
Retraction: The right liver is gently retracted cephalad using a self-retained Dever retractor or a medium-size malleable retractor.
Cholecystectomy: The gallbladder is removed after the cystic duct is ligated and cannulated with a Fr 3.5 Argyle catheter.
Hilar Dissection: The right hepatic artery and portal vein are isolated to demonstrate the demarcation line (Cantlie line).
Transection Marking: The transection line is marked on the liver surface, using IOUS to ensure an adequate margin from the tumor, particularly if it crosses the middle hepatic vein (MHV).
Step 4: Parenchymal Transection
Instrumentation: Transection is performed using the CUSA.
Traction and Hemostasis: 4/0 Maxon sutures provide gentle traction. Small vessels are cauterized or clipped, while larger vessels are controlled with titanium clips or Prolene sutures.
Vascular Guidance: For right hepatectomies sparing the MHV, the right side of the vein is exposed to serve as a guide for transection.
Step 5: Division of the Right Hepatic Duct
Hilar Plate: As transection reaches the liver hilum, the right hepatic duct is encountered. Use of cautery is avoided here to prevent damage to the hilar plate and ensure secure suturing of the duct stump.
Precision: If the tumor is near the duct, an operative cholangiogram may be performed. The duct is divided with scissors and the orifices are sutured with 5/0 polydioxanone suture (PDS).
Step 6: Division of Short Hepatic Veins
Caudate Lobe: The paracaval portion of the caudate lobe is transected with the CUSA to expose the inferior vena cava (IVC).
Vascular Control: Short hepatic vein branches are ligated or plicated as necessary. If the tumor encroaches on the caudate lobe, the MHV is exposed at its junction with the left hepatic vein and divided using an endovascular stapler.
Step 7: Division of the Right Hepatic Vein
Final Separation: The right hepatic vein is divided using an endovascular stapler.
Mobilization: Once disconnected from the IVC, the right liver is mobilized by dividing the triangular ligament.
Diaphragmatic Involvement: If the tumor involves the diaphragm, a portion of the diaphragm is resected in continuity and closed with 2/0 Prolene.
Step 8: Hemostasis and Closure
Leak Testing: Central venous volume is restored, and indigo carmine is instilled via the Argyle catheter to check for bile leaks.
Final Verification: IOUS is repeated to confirm the patency and pulsatility of the left portal vein and left hepatic artery.
Closing: The falciform ligament is reconstituted with 5/0 Prolene. Abdominal drains are rarely necessary.
Technical Specifications and Surgeon Guidelines
Recommended Instrumentation and Materials
"Tricks of the Senior Surgeon"
To ensure optimal outcomes and instrument performance, the following technical adjustments are recommended:
Blood Loss Mitigation: Maintain low central venous pressure through fluid restriction, muscle relaxation, head-up positioning, and deep anesthesia.
Instrument Maintenance: Ensure adequate cooling of the CUSA tip with saline to maintain efficient parenchymal transection.
