Auxiliary Liver Transplantation
Karim Boudjema, Philippe Compagnon, Jean-Pierre Campion
The principle of auxiliary liver transplantation is the implantation of a right or left hemiliver into the abdominal cavity to restore normal liver function temporarily, while the native liver recuperates. Once the native liver has recovered, the graft can be removed or left in place without immunosuppression leading to atrophy.
Indications and Contraindications
Indications ■ Fulminant and subfulminant liver failure (approximately 10% of all liver transplant indications) as defined by the King’s College or the Clichy criteria
■ Fulminant rather than subfulminant form of acute liver failure (interval jaundice/encephalopathy <2weeks)
■ Preferentially acute liver failure due to viral hepatitis (A and B), mushroom intoxication or drugs that are known to induce reversible acute liver failure
Exclusion Criteria ■ General contraindications to transplantation
■ Presence of fibrosis (or cirrhosis) on a frozen section biopsy performed during the procedure
Special Considerations
■ Since there is not enough space in the abdominal cavity to harbor two entire livers, the graft has to be reduced.
■ The reduced liver graft can be implanted heterotopically, i.e., below the native liver, but this technique may lead to a portal steal syndrome and compromise graft vascularization.
■ Orthotopic implantation of the graft is more physiologic and is widely accepted as the standard technique. It implies resection of a native hemiliver. Consequently, two types of auxiliary partial orthotopic liver transplantation (APOLT) can be performed depending on the type of graft that is used:
– Right APOLT (A-1): right hemihepatectomy of the native liver and implantation of a right liver graft (Sg5, 6, 7 and 8 and right part of the dorsal sector)
– Left APOLT (A-2): left hemihepatectomy of the native liver and implantation of either a left lateral section (Sg2 and 3) or a left hemiliver (Sg2, 3 and 4)
■ The liver graft can be harvested from a living donor or a cadaveric donor.
When harvested from a cadaveric donor, the liver can be split in situ or ex situ.
■ Two teams are mandatory and work simultaneously:
– A donor team which procures and splits the graft
– A recipient team which fits up the recipient abdominal cavity and performs the transplantation
Specific Postoperative Complications
■ Primary non-function of the liver graft
■ Bleeding from the cut surfaces of both native and auxiliary livers
■ Stricture of the portal vein anastomosis and subsequent portal steal syndrome and graft non-function
■ Hepatic artery thrombosis and subsequent biliary tract necrosis of an atrophic graft
Procedures
Right Auxiliary Partial Orthotopic Liver Transplantation
Right APOLT is recommended for adult patients in order to raise the graft weight/patient weight ratio above 1%.
This part of the procedure mimics removal of a right living donor procedure except that it can be performed under selective occlusion of the right portal triad.
STEP 1 Exploration, mobilization and resection of the native right hemiliver
After visual and manual exploration of the liver and the entire abdominal cavity, the vascular structures (median hepatic vein and its branches from segments V and VIII) are evaluated by ultrasound with a special emphasis on anatomical variations that may complicate the procedure (i.e., absence of right portal trunk). Next, a wedge biopsy is performed for the evaluation of fibrosis, as the presence of fibrosis or cirrhosis is a contraindication for auxiliary liver transplantation. Parenchymal necrosis is common and its intensity does not necessarily predict the likelihood of recovery.
After cholecystectomy, the right hemiliver is mobilized. Of note, the distal end of the right hepatic vein can be encircled from below using a lace but should not be trans- sected at this stage.
The lateroposterior peritoneal sheath of the right part of the hepatoduodenal liga- ment is opened and the right hepatic artery is gently dissected from behind the common hepatic duct up to its bifurcation and marked with a vessel loop. The right branch of the portal vein is cautiously freed from the hilar plate. This maneuver cannot be performed safely without having controlled and cut one or two small branches to the caudate process. The vein is also marked with a vessel loop.
The right hepatic artery and the right portal vein are temporarily occluded with vascular clamps in order to reveal the demarcation line between left and right hemiliver.
Then both vessels are divided between ligatures, as distally as possible.
The right hepatic duct should not be isolated extrahepatically. It can easily be trans- sected during the parenchymal dissection.
The liver parenchyma is transected 1cm to the right of the main portal fissure, preserving the median hepatic vein. Transection is conducted posteriorly to the retro- hepatic vena cava and the right hepatic duct is divided through the liver parenchyma at the confluence of its anterior and posterior branches. The bile duct from segment one is carefully preserved. Then, the right hepatic vein is transected by means of a vascular stapler (or another technique; see chapter “Right Hemihepatectomy”). At the end the retrohepatic segment of the inferior vena cava is widely exposed, ready to receive the right hepatic graft.
STEP 2 Preparation of the right liver graft
A right cadaveric graft is ideally split in situ. If performed ex situ the median hepatic vein should be preserved on the graft side in order to avoid congestion and bleeding of the graft cut surface at the time of revascularization. The graft includes (A):
■ Segments 5–8
■ The right branch of the hepatic artery
■ The right branch of the portal vein
■ The right hepatic duct(s) along with the confluence and the common hepatic duct
■ The right and median hepatic vein both attached to the retrohepatic inferior vena cava. Since the left hepatic vein has been divided by retaining a narrow patch from the common trunk, the defect has to be closed by transverse suture
In a right living donor graft (see also chapter on living donor liver transplantation), the retrohepatic vena cava, median hepatic vein, and extrahepatic biliary tract must stay on the donor side. Consequently, the graft includes (B):
■ Segments 5–8
■ The right branch(es) of the hepatic artery
■ The right branch(es) of the portal vein
■ The right hepatic duct(s)
■ The right hepatic vein
Implantation of a Right Liver Graft from a Cadaveric Donor
STEP 3 Caval anastomosis
In a cadaveric graft, a caval implantation is performed. The native IVC is clamped later- ally and opened for about 5cm including the ostium of the right hepatic vein. The left side of the graft IVC is widely opened and a side-to-side cavocavostomy with a contin- uous 4-0 Prolene suture is performed. While the posterior layer is stitched, the graft is flushed with Ringer’s or 4% albumin solution.
STEP 4 Portal vein and arterial anastomosis
The native right portal branch stump is clamped at its origin, and it is widely opened.
The length of the graft portal vein is accurately adjusted in order to avoid tearing or kinking. An end-to-end anastomosis is performed between the donor and recipient right portal branch with a 5-0 or 6-0 Prolene running suture, leaving a growth factor of about 5mm. The graft is then revascularized and careful hemostasis performed.
The standard artery reconstruction is an end-to-end anastomosis between the donor and recipient right hepatic artery, using separate stitches of 8-0 Prolene. Donor saphenous vein interposition may be necessary to implant the graft artery more proximally on the recipient celiac axis.
STEP 5 Reconstruction of the biliary tract
After careful hemosthasis, a standard direct duct-to-duct anastomosis with separate PDS 6-0 stitches is performed and a T-drain is inserted. If a standard choledocho- choledochostomy cannot be performed, a Roux-en-Y hepaticojejunostomy would be performed.
Note: Implantation of a Right Liver Graft from a Living Donor
The right liver graft from a living donor differs from the cadaveric graft implantation at step 1 only. Since the IVC has been left to the donor, the graft’s right hepatic vein is implanted in an end-to-side fashion to the recipient IVC
Left Auxiliary Partial Orthotopic Liver Transplantation
Left APOLT is recommended for children since an adult right liver graft may be too large. An adult left lobe or left hemiliver graft is sufficient to provide a graft weight/patient weigh ratio above 1%.
STEP 1 Removal of the native left hemiliver and preparation of the graft
The resection of the native left hemiliver can be performed under selective occlusion of the left portal triad (see chapter “Segmentectomies, Sectionectomies and Wedge Resections”) and includes resection of segment 1 with preservation of the median hepatic vein in the right hemiliver. The left side of the retrohepatic segment of the inferior vena cava is widely exposed to facilitate the left hepatic graft implantation.
For the preparation of the graft, resection of Sg1 is recommended, regardless of the type of graft (Sg2 and 3 or left hemiliver) or the type of donor (cadaveric or living).
The left grafts include:
■ The left branch of the hepatic artery (living donor) or the entire hepatic artery including the celiac trunk (cadaveric donor)
■ The left branch of the portal vein
■ The left hepatic duct
■ The retrohepatic IVC is never left attached to the left graft
■ Either segments 2 and 3, drained through the left hepatic vein (left lateral section)
■ Segments 2, 3 and 4, drained through the left and the median hepatic vein (left hemiliver graft) (A-1,A-2)
STEP 2 Implantation of left liver grafts
The native IVC is clamped anterolaterally, using the remaining stump of the left hepatic vein to expose the vessel. Then, the native IVC is opened vertically on 2cm, beginning at the ostium of the left hepatic vein. An end-to-side anastomosis is performed using a continuous 4-0 Prolene suture between the recipient vena cava and the graft left hepatic vein or common median-left stem. The portal vein is adjusted and implanted with a growth factor as for the right side. The standard artery reconstruction is an end-to-side anastomosis between the graft celiac axis and the recipient common hepatic artery or splenic artery. End-to-end anastomosis between the donor and recipient left hepatic artery is used in case of a living donor graft.
The standard technique for biliary tract reconstruction is a direct duct-to-duct anastomosis, with separate PDS 6-0 or 7-0 stitches, and with insertion of a T-drain.
A Roux-en-Y hepaticojejunostomy is performed in case a direct anastomosis cannot be performed
Tricks of the Senior Surgeon
■ Never start the recipient procedure before the split procedure has been shown to be anatomically feasible.
■ Two teams need to work simultaneously, headed by two experienced liver surgeons.
■ Never start before a biopsy of the recipient liver has been performed. Fibrosis or cirrhosis would lead to perform orthotopic rather than auxiliary liver transplantation.
