Left Hemihepatectomy

 

Executive Summary

This document provides a detailed technical briefing on the procedure for a left hemihepatectomy, as outlined in the Atlas of Upper Gastrointestinal and Hepato-Pancreato-Biliary Surgery. The procedure is a systematic eight-step surgical intervention focused on the mobilization of the left hemiliver, the precise isolation and ligation of vascular and biliary structures, and the controlled dissection of the liver parenchyma.

Key success factors identified in the protocol include the maintenance of low central venous pressure (CVP) to minimize blood loss, the accurate identification of anatomical variations (such as aberrant hepatic arteries), and the preservation of Segment 1. The protocol emphasizes a "safety-first" approach, particularly regarding the timing of hepatic vein transsection and the protection of the middle hepatic vein during parenchymal division.

Detailed Procedural Analysis

The surgical workflow is divided into distinct phases: initial access and mobilization, vascular isolation, parenchymal dissection, and final hemostasis.

Phase I: Access and Mobilization

The procedure begins with a subcostal incision to open the abdomen.

• Ligament Division: The round and falciform ligaments are divided first. Mobilization of the left hemiliver continues with the division of the left triangular and coronary ligaments.

• Anatomical Protection: Unlike the right side, the anterior and posterior leafs of the left coronary ligaments are attached closely to each other and separated near the cava. Electrocautery is used for division while posterior structures (stomach, esophagus, and spleen) are protected using a wet gauze swab or a finger.

• Initial Assessment: Following mobilization, the liver is evaluated via ultrasound to confirm resectability. A Pringle maneuver is prepared by opening the hepatogastric ligament.

Phase II: Hepatoduodenal Ligament and Vascular Control

This phase focuses on identifying and securing the inflow and outflow tracts of the left hemiliver.

• Hepatoduodenal Ligament: Cholecystectomy is typically performed to facilitate parenchymal dissection at the Rex-Cantlie line (the mid-plane). The ligament is opened from the left to visualize the common bile duct, the hepatic artery, and the portal vein.

• Arterial Supply: The arterial anatomy must be clarified. Any aberrant left artery should be secured with a bulldog clamp. Once identified, the left hepatic artery is divided between ties.

• Portal Vein Ligation: The left portal vein is situated behind the left branch of the hepatic artery. A short branch to Segment 1 (Sg1) on the back-left side is divided between ties. The vein is then ligated (1-0 silk) or transsected (vascular stapler).

• Critical Detail: The distance to the bifurcation must be at least 5 mm to avoid stenosis of the remaining right portal vein.

Phase III: Hepatic Vein Exposure and Parenchymal Dissection

This phase involves the transition from vascular isolation to the actual division of liver tissue.

• Arantius’ Ligament (Ligamentum Venosum): This ligament is identified between the left hemiliver and Sg1. By dissecting it upward toward the inferior vena cava, an avascular plane between the left hepatic vein and Sg1 is developed.

• Parenchymal Dissection: Once blood supply is interrupted, a demarcation line appears at the main portal plane, identifying the line of resection.

• CVP Management: It is vital to verify that CVP is low (below 3 mmHg) before beginning.

• Dissection Technique: The capsule is incised with diathermy. Dissection begins on the inferior margin of the caudate lobe and continues toward the surface of the vena cava.

• Protection of Structures: Great care must be taken to protect the middle hepatic vein. The left hepatic duct should be divided close to the umbilical fissure to avoid injury to biliary anomalies.

Phase IV: Transsection and Hemostasis

The final phase involves the completion of the resection and ensuring the integrity of the remaining liver.

• Left Hepatic Vein Transsection: If not divided earlier, the vein is transsected at the top of the liver (2–3 cm from the top) using a vascular stapler or a spoon clamp. Fine preparation may require devices like a CUSA or Hydro-Jet.

• Final Situs: The resection surface is compressed with a gauze swab for several minutes. Any instance of bleeding is suture-ligated (PDS 4-0 or 5-0).

• Bile Leak Detection: The surface is inspected for yellow spots. Alternatively, methylene blue can be injected through the cystic duct stump to identify leaks.

Technical Summary of Procedural Steps

Step	Action	Key Considerations
1	Access and Mobilization	Subcostal incision; divide triangular/coronary ligaments; ultrasound evaluation.
2	Opening Hepatoduodenal Ligament	Cholecystectomy; visualize bile duct, artery, and portal vein.
3	Arterial Disconnection	Clarify anatomy; divide left hepatic artery between ties.
4	Left Portal Vein Ligation	Divide Sg1 branch; maintain 5mm margin from bifurcation.
5	Exposure of Left Hepatic Vein	Dissect Arantius’ ligament to find avascular plane.
6	Parenchymal Dissection	Follow demarcation line; maintain low CVP (<3 mmHg); protect middle hepatic vein.
7	Transsection of Hepatic Vein	Use vascular stapler or spoon clamp; 2-3 cm from the top.
8	Final Hemostasis	Suture-ligate bleeders; check for bile leaks; preserve Segment 1.

Tricks of the Senior Surgeon

The document highlights two specific clinical insights to optimize surgical outcomes:

1. CVP Coordination: Early in the procedure, the surgeon should coordinate with the anesthesiologist to ensure a low CVP. This is the primary method for significantly reducing overall blood loss during the operation.

2. Timing of Vein Isolation: While isolating the left hepatic vein before parenchymal dissection is an option, it is not mandatory. If isolation is difficult, forcing the maneuver can cause severe bleeding. In such cases, it is safer to perform the transsection at the end of the parenchymal dissection; the resulting blood loss is equivalent as long as a low CVP is maintained.