Anestesiologia en Cirugia de Higado

Introduction

Hepatectomy is one of the pillars for the treatment of primary and secondary liver cancer, However, despite the efforts made to improve the prognosis of patients undergoing this intervention, it continues to have perioperative morbidity and mortality elevated Anesthetic management requires general knowledge not only of the surgical implications, but also of the pre, trans- and postoperative organic alterations. In the specific case of the patient with cancer, it is vital. It is important to pay attention to the implications of the associated medication. The role of the anesthesiologist should not be limited to attention within the operating room, but to take a
truly perioperative, starting with an adequate pre-anesthetic assessment, patient selection based in specific clinical criteria, knowledge of the technique surgical, modifications of the hepatic physiology derivatives of surgical manipulation, pharmacological implications and organic of chemotherapeutic agents, as well as radiotherapypia, electrolyte balance, acid-base balance, of adequate control of postoperative pain, among others.

GENERALITIES

Liver cancer ranks fifth in incidence at the worldwide, it is the third cause of death related to cancer and accounts for 7% of the total neoplastic disease inthe world. Hepatocellular carcinoma (HCC) represents more than 90% of primary liver cancers, constituting a global health problem. The incidence of HCC increases progressively with advancing age in all populations, and reaches a maximum at the age of 70 years. The predominance in the male sex, with a relationship from man to woman of 2-4. Approximately 90% of the CHCs are associated with known underlying risk factors. The most frequent factors are chronic viral hepatitis (types Band C), alcohol consumption and exposure to aflatoxin. In patients with HCC, unlike most tumors solid, the coexistence of two conditions that threaten directly life as they are cancer and cirrhosis, complicates the prognostic evaluation. Based on reported data about of the natural history of the disease, the main factors prognoses in patients with CHC are directly related to the state of the tumor (number and size of nodules, presence of vascular invasion and extrahepatic dissemination), function Hepatic (Child-Pugh classification, bilirubin, albumin, portal hypertension and ascites) and general physical condition (ECOG, Karnofsky and presence of symptoms). The etiology still it has not been identified as a prognostic factor. The Clinical Practice Guidelines of the European Association For the Liver Study in conjunction with the Organization Commission for Cancer Research and Treatment (EASL-EORTC GP), support the classification of the Cancer Clinic Hepatic of Barcelona, ​​because they include some prognostic variables such as tumor status, liver functionand general state of health together with dependent variables of treatment, which have been obtained from studies of cohort and randomized clinical trials, in addition to having been validated externally in various clinical scenarios. At the moment, surgery constitutes the main axis of the treatment of HCC, resection and transplantation achieve the best results in candidates submitted to a rigorous selection with a five-year survival of 60-80%, competing as the first option in patients with early tumors in a therapeutic perspective. Hepatic resection is the treatment of choice in HCC in non-cirrhotic patients in whom major resections can be performed with lower rate of complications as well as an acceptable clinical result, representing a survival of between 30 and 50% at five years.

PREANESTESAL ASSESSMENT

The prognosis is directly affected by the severity of and the nature of both the underlying liver disease and by the type and extent of the planned surgery. The presence of obstructive jaundice, significantly increases the. Perioperative mortality, numerous studies have reported risk factors in patients with this condition, which include initial hematocrit> 30%, total bilirubin> 11 mg / dL, presence of malignancy, serum creatinine> 1.4 mg / dL, albumin concentration> 3.0 g / dL, age over 65 years, AST concentration> 90 IU / L and urea nitrogen> 19 mg / dL. An accurate assessment of the extent and severity of the underlying liver disease provides an effective determination of perioperative risk. The Child-Turcotte-Pugh scale (CTP) and the MELD scale (Model for End-stage Liver Disease) (Table I) have been widely used for this purpose. An advantage of the MELD scale is that it provides a continuous scale that may be appropriate according to the type of surgery that will be performed. A patient with a MELD score <10, you can usually enter surgery, if the score is locate between 10-15, certain precautions must be taken, Finally, MELD score> 15, should be considered reprogramar elective procedure and consider the patient as
candidate for liver transplant.

These findings may obviate the need for measurement invasive of the pressure gradient of the hepatic vein. The lesson of patients is increasingly refined, the emphasis on timely diagnosis and improvement in surgical techniques have led to a five-year decrease in mortality. A portal pressure gradient <10 mmHg and a concentration total serum bilirubin, have been shown to be predictive higher results in postsurgical outcomes with rates of five-year survival greater than 70%. By contrast, a venous gradient increased with concentration total serum bilirubin (> 1 mg / dL), are associated with rates of five-year survival less than 30% independently of the patient's CTP classification.

HEPATECTOMY AND CHEMOTHERAPY
It is of vital importance to point out the use of quimyotherapy in the patient undergoing hepatectomy, since the therapeutic options are not limited to CHC, but they often depend on the primary tumor that has given rise to the metastatic liver, thus increasing the complexity and variability between one patient and another, apparently they will be subjected to the same procedure. The effects of chemotherapeutic agents are summarized by organic system affected in table II.

...