Laparoscopic approach to the hilum
Dissection of the right pedicle during laparoscopic right hepatectomy
In order to perform a right laparoscopic hepatectomy the approach to the pedicle is from the right side of the pedicle itself. The first step involves the identification and ligation of the cystic duct and cystic artery, leaving the gallbladder in place which is then used to exert traction in order to facilitate the isolation of hilar vascular structures; at times, before dissecting Calot’s triangle, a simple traction of the gallbladder’s infundibulum allows a better exposure of the right hepatic artery. Then, using the cystic artery stump as a traction element, the right hepatic artery is isolated by blunt dissection. Isolation of the right hepatic artery must be performed as proximally as possible, so as to be sure of not damaging the vascularization of the main biliary tract. After its complete isolation, with the aid of a dissector the artery is encircled by a vessel loop in order to allow traction of the vessel and thus facilitate its ligation and sectioning.
Sectioning of the right hepatic artery allows an easier access to the right portal branch, which is on a deeper plane within the hepatic pedicle. Isolation of the right portal branch is also achieved via blunt dissection until achieving isolation of the vein at 360°. As in the case of the right hepatic artery, at the end of the isolation procedure the right portal branch is encircled by a dissector and then by a vessel loop.
Before proceeding with the ligation it is advisable to place a vascular clamp on the right portal vein in order to control the correct area of ischaemia on the liver surface, thus preventing eventual mistakes in the isolation of hepatic hilum structures.
After this it will be possible to ligate between the clips and to divide the right portal branch.
Dissection of the right pedicle after portal vein occlusion: portal vein embolization and ligation
As in a classical right hepatectomy, during the first step of a two-stage laparoscopic hepatectomy the approach to the pedicle is on the right side of the hepatic pedicle and involves the use of the gallbladder for traction. The procedure continues with the identification of the right hepatic artery, which is isolated only as much as necessary so that it can be lifted and in order to allow access to the portal vein. Partial isolation of the hepatic artery is also justified by the need of limiting the dissection in order not to complicate the subsequent second operation.
Dissection is continued until the right portal branch is identified, isolated, and then encircled by a vessel loop passed twice with the aid of a dissector. The double passage of the vessel loop is essential as this allows control of the hepatic inflow.
A butterfly cannula is inserted in the right portal vein and then 10 ml of alcohol are injected while keeping the vessel loop under traction in order to avoid the retrograde flow of the injected liquid. At the end of the injection a partial release of the vessel loop allows blood flow into the portal branch, thus allowing the distribution of the alcohol into the intrahepatic portal branches of the right liver.
While exerting a slight traction the right portal branch is closed with a clip.
In the second operation the greatest difficulties are caused by the sequelae of the first intervention, i.e. the presence of fibrosis which makes the structures less recognizable.
The cystic duct and cystic artery are isolated and resected, leaving the gallbladder attached to its hepatic bed and available as a traction element.
The right hepatic artery is then isolated and encircled by a vessel loop with the aid of a dissector. Traction of the vessel loop facilitates clip attachment and sectioning of the artery.
Once the artery has been resected the right portal branch, already isolated in the previous operation, is identified; it appears sclerotic due to the effect of ligation and alcoholization. The clip placed in the previous surgery is a useful landmark for an easier identification of the vein.
The right portal branch is then isolated, encircled by a vessel loop, clipped and divided.
Dissection of the left pedicle
When performing a left laparoscopic hepatectomy the approach to the pedicle is on its medial side; to reach the pedicle the lesser omentum needs to be dissected.
An incision is made on the peritoneum covering the hepatic pedicle in order to reach the vascular structures within.
The first step of the procedure involves identification and isolation of the left hepatic artery; once isolated, it is then clipped and resected.
Once the artery has been resected, on a deeper plane it is possible to recognize the portal bifurcation. The left portal branch is identified and isolated by blunt dissection.
When isolating the left portal vein, the portal branch for the left Sg1 must be identified and preserved. In fact, the dissector must be introduced cranially to the origin of the latter. By under passing the left portal vein with a vessel loop, traction may be exerted, facilitating clip placement and the subsequent sectioning of the vessel.