Editing Liver resection (section)

== '''Principles''' ==

* It is possible to remove any single segment with jeopardising blood supply or biliary or venous drainage to the rest of the liver, but sometimes it is easier to remove more than just the involved segment
* Most blood loss comes from hepatic veins - operate with a low central venous pressure (central line, mild Trendelenburg, fluid restriction, and venodilators if necessary, aiming central venous pressure <5mmHg)
* To decrease mortality, minimise blood loss, amount of normal liver resected, and maximise function of remnant liver
* Carefully plan with '''FLR (Future Liver Remnant) in mind and optimise it if required'''
*# Quantify expected remnant
*#* Volumetric CT or MRI
*#* Some centres perform functional nuclear medicine study - technetium-99m-labelled mebrofenin hepatobiliary scintigraphy
*# Assess liver quality
*#* Worse regeneration in cirrhosis, steatosis, obesity, diabetes, age > 65, sepsis, prior chemotherapy
*# Compare against minimum required to avoid post-op liver failure (POLF)
*#* In normal healthy liver, 80% can be resected without increasing risk of PHLF
*#* Safe FLR in mild CLD (fibrosis but no cirrhosis) is 30-35%; in C-P A cirrhosis safe FLR is 40%
*#* If C-P B/C or MELD > 10-12 and portal HTN, even a small resection can result in PHLF, and advanced cirrhosis is therefore a contraindication. There is also a constant risk of further HCC in the remnant. These patients would theoretically need a transplant.
*# Optimise FLR if necessary
*#* Portal Vein Embolisation
*#** Best first choice
*#** FLR increases 40-60% in 6 weeks - risk of disease progression while waiting
*#* 90Y radioembolisation
*#** Low risk
*#** FLR increases 30% in 6 weeks
*#** Possible reduced risk of progression during that period due to anti-tumour effect
*#* Portal vein ligation
*#** Low-moderate risk
*#** FLR increases 30-43% in 6 weeks
*#** Main operation may be harder due to porta scarring
*#* ALPPS (associating liver partition and portal vein ligation)
*#** PV and hepatic arterial segmental ligation
*#** Higher morbidity and mortality
*#** Again, two operations, might be harder second time
*#** Fastest growth (up to 80% in a week)
*#** Can be considered if other techniques have not been sufficient
* Strategies to avoid PHLF
** Limited pringle maneuvre/intermittent clamping
** Meticulous surgical technique to avoid blood loss
** Avoid prolonged operation
** Plan and optimise FLR from the start
* Anatomical resections are much more likely to have negative margins in malignant disease than wedge resection