Extended Hemihepatectomy

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Executive Summary

Extended hemihepatectomy, also known as trisectionectomy, is a complex surgical procedure involving the removal of the majority of the liver. The procedure is categorized into extended right and extended left hemihepatectomies, each defined by the specific liver segments targeted for resection and the requirement for a viable remnant liver.

The primary indications for these procedures include cholangiocarcinoma of the liver hilum (Klatskin’s tumor) and gallbladder carcinoma. Success is predicated on rigorous preoperative assessments, including liver function tests, volumetric evaluations, and the exclusion of underlying conditions such as fibrosis or cirrhosis. Critical surgical maneuvers include the selective ligation of specific segment pedicles, the management of the hepatic veins, and, in the case of right-sided resections, the reattachment of the falciform ligament to prevent fatal complications like Budd-Chiari syndrome.

Extended Right Hemihepatectomy (Right Trisectionectomy)

Scope and Indications

The extended right hemihepatectomy involves the resection of liver segments 4 through 8. For cases involving cholangiocarcinoma of the liver hilum or gallbladder carcinoma, an en bloc resection typically includes segments 1 and 9 (the caudate lobe).

Preoperative Prerequisites

The procedure is high-risk and should only be performed if the remaining liver (segments 2 and 3) provides sufficient function. Essential assessments include:

  • Functional Assessment: Preoperative evaluation of liver function.

  • Volumetric Assessment: Measurement of the expected remnant liver volume.

  • Tissue Health: Exclusion of liver fibrosis or cirrhosis.

Surgical Methodology

Two primary approaches exist for resecting segment 4 (Sg4):

  1. Classic Anatomic Resection: Selective ligation of the Sg4 pedicle prior to tissue transection.

  2. Alternative Approach: Ligation of the Sg4 pedicle during the parenchymal transection process.

Key Surgical Steps

  • Selective Ligation (Step 8): Following right liver mobilization and ligation of right hepatic artery and portal vein branches, a careful blunt dissection is performed along the left portal sheath to identify and selectively ligate the Sg4 pedicle.

  • Parenchymal Transection (Step 9): The resection margin follows the right side of the falciform ligament. The round ligament is used as a guide, and intraoperative ultrasound is routinely used to define the lesion and vascular anatomy.

  • Venous Management (Step 10): The right and middle hepatic veins are isolated and divided, often using a vascular stapler. Because these veins frequently share a common trunk, care must be taken to preserve the left hepatic vein.

  • Ligament Reattachment (Step 11): The falciform ligament must be reattached to prevent the remnant liver from rotating. Failure to do so can lead to acute Budd-Chiari syndrome, a fatal obstruction of the liver's venous outflow.

Extended Left Hemihepatectomy (Left Trisectionectomy)

Scope and Remnant Requirements

This procedure involves the resection of segments 2, 3, 4, 5, and 8. It requires a viable remnant consisting of segments 1, 9, 6, and 7. Similar to right-sided procedures, preoperative functional and volumetric assessments are mandatory.

Surgical Methodology

As with the right-sided approach, the surgeon may choose to ligate the pedicles to segments 5 and 8 (the right anterior pedicle) before or during tissue transection.

Key Surgical Steps

  • Selective Ligation (Step 8): The right anterior pedicle is identified via blunt dissection. While these vessels are ligated, the right posterior pedicle must be strictly preserved. Intraoperative ultrasound is highlighted as a helpful tool for identifying anatomy in these cases.

  • Venous Exposure (Step 9): The middle and left hepatic veins, which usually share a common trunk, are isolated from above. The right hepatic vein must be identified and preserved.

  • Transection (Step 10): Tissue is divided along a demarcation line, typically located approximately 1 cm to the left of the right hepatic vein.

  • Final Ligation (Step 11): The left and middle hepatic veins are transected using a vascular stapler. The caudate lobe (segments 1 and 9) can be resected en bloc if necessary.

Advanced Surgical Considerations ("Tricks of the Senior Surgeon")

The following strategies are utilized to manage complex cases or technical difficulties during extended resections:

Scenario

Strategy/Recommendation

Tumors invading Sg4, Sg5, or Sg8

Rather than selective ligation, perform a formal hemihepatectomy and extend the resection margin into the contralateral liver (extended wedge resection).

Hilar Cholangiocarcinoma

Avoid hilar dissection of segmental pedicles; instead, perform ligation during tissue transection to spare liver parenchyma and operative time.

Difficult Venous Isolation

Consider two strategies: transection of hepatic veins during parenchymal transection without previous isolation, or total vascular exclusion.

Small Remnant Liver

If the predicted remnant liver volume is insufficient, portal vein embolization should be considered approximately four weeks prior to the planned resection.

Technical Nuance in Transection

In the event that the pedicle to segments 5 and 8 cannot be ligated first during an extended left hemihepatectomy, the surgeon should proceed with transection roughly 1 cm to the left of the right hepatic vein. Constant attention must be paid to the right hepatic vein's course throughout the procedure to ensure its preservation.