Hepatic resection

1093

Limited by need to preserve sufficient amount of functional liver, because excessive resection leads to liver failure and death within a few days after surgery.

For gastric metastases 1-year, 3-year and 5-year survival rates after hepatic resection are respectively, 77%, 34% and 34%.

Perioperative risk for resection of colorectal metastases 2-4% mortality.

Perioperative risk for hepatic resection neuroendocrine metastases are 24% morbidity and 3% mortality.

Only 10-20% of patients with hepatic malignancies are candidates for potentially curative resection.

Major resection of the liver associated with <5% mortality and 5%-15% morbidity.

In experienced centers resection of liver metastases has decreased to approximately 1%

Following resection, the liver can regenerate lost volume within 2 weeks.

Only available treatment associated with long term survival in colorectal cancer is resection.

Following resection of liver metastases in colon cancer the 5-year survival ranges from 37-58% in recent studies.

Definition of resectability includrs tumor chracteristics and establishing adequate liver remnant exists with adequate vascular inflow, outflow and biliary drainage.

Resectability depends on the number and location of metastases, volume of the future liver remnant and quality of the non-tumoral liver.

Median survival for selected colorectal cancer patients, after resection is greater than 40 months and 10 year survival rates up to 20% (Scheele J).

The combination of systemic chemotherapy and safe surgical resection of liver metastases in colorectal cancer allows five year survival rates of 40 to 60%.

In colon cancer surgery aims at complete tumor removal because incomplete resection has a similar outcome as non-resected patients.

In colorectal cancer liver metastases resection, no single negative prognostic prognostic feature precludes durable long-term survival.

Despite resection in colorectal cancer and liver metastases, the liver is the most common site of recurrence after metastasectomy (Topal B).

10 mm is the recommended surgical margin for colon metastases, but it is not a strict contraindication for resection.

In colorectal cancer goals of resection are to achieve negative margins, while preserving 2 contiguous hepatic segments, vascular inflow and outflow, and biliary drainage, and an adequate remnant of 20% of healthy liver.

In colorectal cancer hepatic metastases resection the predominant prognostic factor for long-term survival is disease free margin.

Colorectal cancer patients with liver metastastases are classified into 3 categories-1-easily resectable, 2-marginally resectable, and-3 unresectable.

10-20% of patients with colorectal liver metastases are resectable. and 80-90% are not resectable at presentation.

The presence of lymph node metastases relates to a dismal prognosis and in general obviates hepatic resection of metastases.

For colorectal liver metastases resection associated with poor outcomes when findings include: node positive disease, disease free interval less than 12 months, more than 1 liver metastasis, liver metastasis greater than 5 cm in size and CEA greater than 200 ng/mL.

For colorectal hepatic metastases portal vein embolization on the side of resection can potentially improve outcomes by stimulating growth on the other side of the liver and allowing an increased functional liver volume.

Ultrasound is useful for intraoperative staging and contrast enhancement may improve the sensitivity of this procedure.

Colon cancer patients without extrahepatic disease, with good liver functions and in good general condition may be eligible for surgery.

The classic contraindications for colon liver metastases resection are more than 4 metastases, extrahepatic disease and resection margin of <1cm.

Absolute contraindication to such surgery for hepatic metastases with colon cancer are: unresectable disease, >70% liver involvement, liver failure and poor general medical status (Poston).

Extrahepatic colon cancer predict for poor disease-free survival and overall survival: In a review of 929 consecutive patients undergoing hepatic resection for metastatic colorectal cancer the presence of resected and undissected extrahepatic disease was associated with a 5 year overall survival rate of 15.5% compared with a 36.6% for patients without extrahepatic disease (Rees M).

Preoperative chemotherapy can induce injury to deliver, primarily steatohepatitis and sinusoidal injury.

The limits of technical hepatic resection include leaving behind at least two contiguous liver segments with adequate vascular inflow and outflow, adequate biliary drainage, in adequate future liver remnant.

A major hepatectomy includes removal of three or more segments.

The future liver remnant is one of the major determinants of postoperative hepatic failure.

Future liver remnant is calculated using three-dimensional CT volumetry.

With normal underlying liver function, a future liver remnant of at least 20% is recommended.

Patients with cirrhosis and those treated with systemic chemotherapy a larger future liver remnant is recommended with 40% for cirrhosis, and 30% for systemic chemotherapy.

Patients who have a liver remnant associated with a risk of post hepatectomy liver failure the use of ipsilateral atrophy of the tumor bearing liver and compensatory hypertrophy of the future liver remnant by selectively occluding the blood flow to the tumor bearing part of the liver can be performed.

Portal vein embolization can be offered patients with normal liver function with future liver remnant of 25-30%, to those with compromised liver function, such as post chemotherapy liver damage, cirrhosis, and cholestasis, and a future liver remnant of 35 to 40%.