الفهرس 
SURGICAL ANATOMY OF THE LIVEROnly 14 pages are availabe for public view
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Abstract
F
rom a surgical point of view, the liver is divided into right and left lobes of almost equal size by a major fissure (Cantlie’s line) running from the gallbladder fossa in front to the IVC fossa behind. This division is based on the right and left branches of the hepatic artery and the portal vein, with tributaries of bile (hepatic) ducts following. The middle hepatic vein (MHV) lies in Cantlie’s line.
Each lobe is divided into 2 sectors. The sectors are further divided into segments (after Couinaud); each segment has its own blood supply and biliary drainage.
Hepatic arterial anatomy and its multiple variations and their surgical implications, the anatomy of hepatic veins, portal vein and biliary tree must well recognize in any hepatic surgery.
While the works of previous authors have made important contributions to understanding hepatic anatomy, it is Couinaud’s fundamental system that has been most readily adopted by the surgical community, albeit with important modifications.
Couinaud’s system is based on the principle that individual segments of the liver must have independent vascular inflow, outflow, and biliary drainage.
The main aetiology of liver transplantation still hepatitis C, B and other viruses, alcohol, cryptogenic cirrhosis, non-alcoholic steatohepatitis, cholestatic liver disease, malignancy, fulminant liver disease, metabolic diseases, pediatric indications and re-transplantation. Also, it is important to know there are relative and absolute contraindications for liver transplantation.
Despite the challenging nature of the technique of LDLT, there have been continuous innovations. A better understanding of complex surgical anatomy and physiologic differences of partial hepatic allografts has helped to avoid graft congestion, small-for-size syndrome, or graft hypo-perfusion from portal flow steal.
Quality of the donor and matching donor and recipient characteristics are very important determinants of peri-transplantation and post-transplantation organ function.
Living donor hepatectomy is a challenging procedure requiring precision and coordination with the recipient team. As the donor team starts with a healthy person, the target rate of complications is as low as possible. Fully laparoscopic procurements have been reported now by multiple centers.
Over time it has become apparent that there are four essential requirements for technically successful LDLT for the recipient: adequate graft volume to avoid SFS graft syndrome; good venous outflow to prevent congestion injury; sufficient portal inflow for rapid liver graft regeneration; and secure bile duct (BD) anastomosis to prevent biliary leak and stricture.
There are numerous predisposing agents and the risk factors that lead to vascular complications. Although the Variety of these factors, the overall incidence of these complications in adults varies widely among transplant centers worldwide, but remains around 13 % in living donor liver transplantation. Bleeding, stenosis and thrombosis can arise at any of the vascular anastomoses, as well as aneurysms at the arterial anastomosis and exceptionally on the portal vein with an overall reported incidence of 7.2 % - 15 % in adults.
Usually, therapeutic options include surgical revascularization, percutaneous thrombolysis, percutaneous angioplasty, re-transplantation and a conservative approach. Although surgical treatment used to be considered the first choice for management, advances in endovascular intervention have increased to make this a viable therapeutic option following orthotopic liver transplantation.
In recent decades, huge advances in the field of interventional radiology have radically changed the diagnostic and therapeutic approaches to vascular complications in liver transplant patients technical improvements made in the catheterization of hepatic vessels and computed imaging allows a specific and localized intervention on these pathological vessels, in a less invasive way. As a matter of fact, percutaneous endovascular therapies (i.e., catheter-based thrombolytic intervention, balloon angioplasty and stenting) provided by an experienced interventional radiologist are commonly employed and have supplanted surgery as the therapy of choice in almost all cases.
In HAT, there are three treatment modalities; Re-vascularization (surgical or endovascular), re-transplantation and observation. Currently, the most effective treatment approach remains controversial and the choice of any of these treatments depends on the time of diagnosis.
In HAS, The therapeutic management includes surgical revision, re-transplant or percutaneous endovascular interventions, such as percutaneous transluminal angioplasty (PTA) with or without stent placement.
In HAP, treatment can be achieved by re-operation or interventional radiology.
In HAR, available treatment options include definitive ligation of the HA, anastomotic revision, aorto-hepatic grafting, percutaneous embolization.
In PVT, Therapeutic options range from systemic anticoagulation to catheter-based thrombolytic therapy, to surgical revision until re-transplantation. And other percutaneous options include; Trans-hepatic portal vein
angioplasty (with or without stent placement), percutaneous thrombolytic therapy via trans-jugular intrahepatic porto-systemic shunt (TIPS) creation or tran-splenic approach.
In PVS, Surgical treatment including anastomotic revision or re-transplantation is usually preferred for early portal inflow abnormalities following liver transplantation but In cases of asymptomatic patients with normal hepatic function test results, PVS may be solely observed with no therapeutic intervention.
In HVOO, Early diagnosis of HVOO after liver transplantation is the key point to allow immediate intervention and prevent graft dysfunction or even graft loss. Some surgeons recommend immediate surgical intervention to correct the cause of mechanical obstruction. However, others recommend percutaneous interventions as balloon angioplasty or stent placement as surgical interventions are dangerous and followed by unfavorable outcome.
In HVS, Endovascular balloon angioplasty and stent placement have been advocate as safe and effective initial treatments to manage this complication following LDLT, and considered therapeutic alternatives with minimal risk compared to surgical repair or repeat transplantation.