Principles of Hepatic Resection Flashcards
most blood loss during a liver resection comes from the
hepatic veins
Patient Position and Lines ? CVP ?
- central line
- mild Trendelenburg position
- fluid restriction
- venodilators if necessary to maintain a central venous pressure lower than 5 mm Hg
The three most critical factors related to perioperative morbidity
blood loss
the amount of normal liver resected
condition of the liver itself (e.g., cirrhosis)
Bile leaks and Tx?
- problem in cases requiring complex biliary reconstruction
- also occur in approximately 10% to 20% of hepatectomies without biliary reconstruction.
- Careful ligation of biliary radicals is of obvious importance in minimizing this complication.
How much liver can be resected ?
Because of the regenerative capacity of the liver, resections of up to 80% of normal noncirrhotic livers can be performed
at what percentage liver dysfunction is minimal ? and what about cirrhotic liver ?
- The risk of hepatic dysfunction is minimal if the reduction of functional liver parenchyma is less than 50%
- Cirrhosis have much higher rates of postoperative liver dysfunction because of impaired regenerative capacity and impaired primary liver function.
Who cannot Tolerate Liver resection ?
Child class B or C cirrhosis
or portal hypertension
One strategy to minimize postoperative liver dysfunction and morbidity after major hepatectomy
- embolize the portal vein percutaneously on the side of the liver to be resected.
- In approximately 4 weeks, this induces atrophy of the liver parenchyma to be resected and hypertrophy of the FLR
Nomenclature for most common major anatomic hepatic resections.
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colorectal liver metastases Oncological vs non anatomical resection ?
parenchymal sparing nonanatomic resection provides comparable oncologic outcomes with marked reduction in complications when compared to major hepatic resections
Rt and Lt hepatectomy
segments V through VIII»_space; right hepatectomy and right hemihepatectomy
Segments II through IV »_space; left hepatectomy and left hemihepatectomy
Extended Rt or Lt
- Right hepatectomy + segment IV
- Left hepatectomy + segments V and VIII.
- right-left trisectionectomy
- trisegmentectomy
left lateral segmentectomy or left lateral sectionectomy.
- Resection of segments II and III is a commonly performed sublobar resection
right posterior sectorectomy-sectionectomy and right anterior sectorectomy-sectionectomy
the right posterior sector (segments VI and VII)
or the right anterior sector (segments V and VIII)
The most basic steps can be distilled down to
- inflow control (portal vein, hepatic artery, bile duct),
- outflow control (hepatic veins)
- parenchymal transection, with preservation of a liver remnant of adequate size with intact inflow, biliary drainage, and venous outflow.
anatomic resection
- Mobilization of the liver
- division of the right or left triangular ligaments
- mobilized completely off the vena cava
- hepatic vein of the resected portion of liver is often encircled before the resection.
- Classic inflow control is obtained by dissection of the liver hilum, with control of the portal vein and hepatic artery to the hemiliver to be resected.
- dividing the bile duct within the liver substance to minimize absolutely contralateral biliary injuries related to anatomic anomalies
- The inflow pedicles can be encircled by making flanking hepatotomies or by splitting parenchyma down to the pedicle of interest.
- The pedicle can usually be divided with a vascular stapler, but suture ligation is sometimes necessary.
- The hepatic vein is divided in its extrahepatic position, which can also usually be done with a vascular stapler
number of methods of parenchymal transection, ranging from
- complex ultrasonic irrigators
- to radiofrequency energy coagulators
- to a simple clamp-crushing technique
