Hepatic trisegmentectomy and other liver resections

Abstract

Trisegmentectomy, extended right hepatic lobectomy, is the removal of the true right lobe of the liver in continuity with most or all of the medial segment of the left lobe. Some important features of the operation have not been well described previously. To perform trisegmentectomy safely, a fusion of liver tissue covering the umbilical fissure at the level of the falciform ligament must first be split open in many patients. The left branches of the portal triad structures are mobilized from the undersurface of the liver nearly to but not into the umbilical fissure. The blood supply and duct drainage of the medial segment originate within the umbilical fissure and feed back toward the right side buried in liver substance. They are found with blunt dissection just to the right of the falciform ligament, encircled and ligated. Failure to appreciate this switch back anatomic arrangement may lead to injury of the blood supply or biliary drainage of the residual lateral segment. Parenthetically, the mirror image operation of lateral segmentectomy could result in devascularization of the medial segment if dissection and ligation were performed within the umbilical fissure instead of well to the left of this landmark. In most trisegmentectomies, the left portion of the caudate lobe is not removed. This small piece of tissue is interposed between the lateral segment and the inferior vena cave into which it drains by small tributaries. If the left portion of the caudate lobe is to be excised, it is necessary to ligate the last two posteriorly running branches before the main left trunks of the portal triad structures reach the umbilical fissure. Once this step is taken and if the caudate removal is completed, the remaining lateral segment usually has only one remaining outflow, that of the left hepatic vein. The other principles of trisegmentectomy are the same as with less radical subtotal hepatic resection. These include vascular suture closure of the main outflow veins, avoidance of parasegmental planes that leave behind a strip of devitalized tissue, preservation of intersegmental or interlobar veins, omission of techniques that sew shut or otherwise cover the raw surface of the remnant and provision of adequate drainage of dead space. After trisegimentectomy and also after true lobectomy, this last objective is usually met by leaving part of the operative incision open. Using these guidelines, there has been no mortality with 27 hepatic resections carried out since 1963, including 14 trisegmentectomies.

FIG. 1

The usual kinds of partial hepatectomy. Note that there are only four common resections.

FIG. 2

Approaches for trisegmentectomy or true right lobectomy. Note that several extensions may be made from the basic right subcostal incision, A to A, that is always used. More than one of the depicted extensions may be required in a given patient. For left hepatic lobectomy or lateral segmentectomy, mirror images of the shown extensions can be added to the basic left subcostal incision, although it is almost never necessary to have a left thoracic component.

FIG. 3

Devascularization of the true right lobe. The cystic artery and cystic duct are ligated and divided to aid in the dissection. Of the structures of the portal triad, the bifurcation of the duct is almost always the most superior, that of the portal vein is intermediate and that of the hepatic artery is most inferior. The lateral suture closure of the portal vein is at the site of detachment of the right portal branch. The tissue bridge conceals the umbilical fissure, behind which a finger can be inserted. The bridge is present in about half the patients.

FIG. 4

Posterior approach in dissecting the bifurcation of the portal vein. This maneuver is made possible by retracting the right lobe of the liver anteriorly and to the left.

FIG. 5

Nearly completed mobilization of the left branches of the portal triad. The tissue bridge is being broken down to permit access to the umbilical fissure. The final two branches before the main trunk reaches the umbilical fissure go to the left portion of the caudate lode. These final branches or at least the last one should be preserved unless all of the caudate lobe is to be removed. Total caudata removal is not usually necessary.

FIG. 6

Structures feeding back from the umbilical fissure to the medial segment of the left lobe. A, These are encircled usually by blunt dissection within liver substances just to the right of the falciform ligament and umbilical fissure without entering the fissure. Note that the hepatic tissue bridge concealing the umbilical fissure has been broken down. B, The three segments of the specimen are now devascularized.

FIG. 7

Division of the right hepatic vein. With the right lobe of the liver retracted anteriorly and to the left, the vein is divided between Pott's clamps and oversewn with vascular sutures. Several smaller hepatic veins must be ligated as they enter the retrohepatic vena cava more inferiorly.

FIG. 8

Liver transection nearly completed along exact line of color change demarcated by viable and cyanotic liver tissue. Intersegmental veins are left attached to the lateral segment if possible. The last major structure to be encountered is the middle hepatic vein.

FIG. 9

Wound drainage after trisegmentectomy. Usually, either the medial or lateral portion of the wound is left open for 3 or 4 inches.

FIG. 10

Site of ligation of portal structures for lateral segmentectomy. The dissection is kept to the left of the umbilical fissure to prevent injury to the structures feeding back from the fissure to the medial segment.