Nonhepatic surgery in the cirrhotic patient

Overview

Chronic liver disease and cirrhosis were the eleventh leading cause of death in the United States and resulted in more than 44,358 deaths in 2019. Chronic viral infection (see Chapter 68 ) and alcohol abuse account for the majority of the disease burden globally, but the incidence of obesity-associated nonalcoholic fatty liver disease (see Chapter 69 ) accounts for an ever-increasing proportion of cases, especially in Western societies. Clinicians continue to gain knowledge and skills to care for patients with cirrhosis in the end stages of their disease, and this has led to a significant increase in the number of patients with comorbid liver disease and cirrhosis encountered in both general and specialty surgical practice.

Cirrhosis can have dramatic effects on multiple organ systems, making surgery on the cirrhotic patient a complex and difficult undertaking (see Chapters 74 and 77 ). A population-based study demonstrated that people with cirrhosis, in particular those with portal hypertension, have significantly worse outcomes after elective operations than those without cirrhosis. The mere act of opening the abdominal wall in a cirrhotic patient with portal hypertension causes collateral blood vessels to dilate and may lead to systemic hypotension and hepatic decompensation secondary to ischemia. ^, Numerous other physiologic alterations in the cirrhotic patient also require added attention perioperatively to their volume status, dosing of many common anesthetics and analgesics, and management of any coagulopathies.

Extrahepatic surgery in the cirrhotic patient may be a formidable undertaking. Increased risk has led some to advise avoidance of surgery unless absolutely necessary. ^, However, cirrhotic patients are more likely to undergo emergency surgery than patients without cirrhosis despite worse outcomes in the emergency setting. These patients have a 4-fold to 10-fold higher postoperative mortality rate following emergency procedures and a major complication rate 5-fold to 7-fold higher than for elective procedures. For this reason, necessary extrahepatic surgeries undertaken in the elective setting are likely to be safer for the cirrhotic patient. The objective of this chapter is to provide practical knowledge on how to evaluate these patients before surgery, as well as current information on some of the most commonly performed procedures in this unique population.

Evaluation and stratification of liver disease (see Chapter 4 )

The decision regarding whether a cirrhotic patient is medically fit to undergo an operation can be difficult to make. Many factors must be considered, but the most important are the magnitude (emergent vs. elective) and type of proposed operation (major abdominal vs. orthopedic vs. high-risk cardiac), the nonhepatic comorbidities of the patient, and the severity of the liver disease. Numerous factors have been correlated with poor outcome in patients with cirrhosis—including low albumin levels, blood transfusion requirements, abnormal coagulation, and ascites—and various scoring systems to gauge these have evolved. The first developed scoring system was the Child-Turcotte-Pugh (CTP) system, which incorporates several objective and subjective variables to stratify severity of liver disease. Two older studies of operative mortality in cirrhotic patients produced nearly identical results with CTP scores of A, B, or C showing operative mortality rates of 10%, 30%, and 80%, respectively. ^, A retrospective review of 64 cirrhotic patients undergoing various intraabdominal and thoracic surgeries from 1999 to 2005 suggested a 1-year operative mortality rate in patients with CTP A, B, or C of 9%, 29%, and 70%, respectively. They compared the strengths of three scoring systems, further discussed below, and concluded that CTP was slightly better at estimating 30-day morbidity in this patient population.

The Model for End-Stage Liver Disease (MELD) score was developed to predict death after transjugular intrahepatic portosystemic shunt (TIPS) (see Chapter 85 ) to stratify the risk of progression to liver failure and the need for liver transplantation. What followed was establishment of the MELD score to predict morbidity and death after nonshunt abdominal surgery. ^{, ,} As with CTP, MELD correlates with risk of postoperative death ( Figs. 75.1 and 75.2 ). Several reports have found that MELD is superior to CTP in predicting postoperative morbidity and mortality. ^, More recently, integrated MELD (iMELD), which incorporates both serum sodium and age into risk calculation, has been found to be superior to both CTP and standard MELD in mortality prediction for cirrhotic patients undergoing emergency surgery. Interestingly, the survival rates from the more recent series indicate a fairly dramatic improvement in survival compared with older series ( Fig. 75.3 ).

In addition to factors considered in MELD and CTP scoring, other factors have been identified for risk stratification and prediction in cirrhotic patients undergoing major operations (see Chapter 26 ). These include elevated creatinine level, chronic obstructive pulmonary disease (COPD), male gender, and an American Society of Anesthesiologists (ASA) class of IV or V. Teh et al. developed the Mayo model and demonstrated ASA classification as a useful marker to further stratify the comorbid illness in cirrhotic patients preoperatively. This case-control study of cirrhotic patients who underwent major nontransplant operations identified MELD score, ASA class, and age as predictors of perioperative death. An ASA class of IV was equivalent to the addition of 5.5 MELD points in added risk, and age greater than 70 years was equivalent to three additional MELD points. A single point increase in MELD score was associated with a 15% increase in perioperative death in the first year. Emergency surgery predicted in-hospital death, although patients undergoing emergency operations had a higher median MELD score. ASA class V was the strongest predictor of 7-day mortality, and MELD score was the most robust predictor beyond 7 days. The median survival of patients in this series was 4.8 years for a MELD score of 0 to 7, 3.4 years for a score of 8 to 11, 1.6 years for 12 to 15, 64 days for 16 to 20, 23 days for 21 to 25, and 14 days for 26 or greater. Newer models have been developed in recent years that aim to incorporate more granular data than the Mayo model. Sato et al. created the ADOPT-LC score incorporating patient age, CTP, Charlson comorbidity index, and duration of anesthesia in surgery into a risk model for in-hospital mortality of cirrhotic patients undergoing elective major surgical procedures in Japan. They found the aforementioned factors to be most predictive of in-hospital mortality and, when incorporated into a model, produced a better Area Under Curve than CTP score alone (0.881 vs. 0.803; P = 0.01). One of the latest models, the VOCAL-Penn model, used data on 4712 surgical procedures (among abdominal wall reconstruction, vascular, cardiac, chest, orthopedic, and abdominal surgeries) in 3785 cirrhotic patients to develop a model more predictive of postoperative mortality than the Mayo risk score, MELD, MELD-Na, or CTP at 30 and 90 days. The VOCAL-Penn model included many of the same predictors as the Mayo model but also featured emergency indication and a surgery-specific category. The investigators were able to achieve a C-statistic for prediction of postoperative mortality significantly higher than all other model scores at 30 and 90 days in both their derivation and validation cohorts. However, this and other models developed in recent years have yet to be externally validated, and CTP and MELD-Na remain the commonly used models for morbidity and mortality prediction specifically in cirrhotic patients undergoing surgical procedures.

Perioperative management and optimization

The perioperative management of patients with cirrhosis involves aggressive attempts to control the various manifestations of their underlying disease. Much of this is covered at length in other chapters (see Chapters 26 and 77 ). Nonetheless, a few considerations are worth mentioning here.

In patients with liver cirrhosis the protein-energy malnutrition can range from 20% to 60% depending on clinical stage of chronic liver disease, placing them at an increased risk for developing a variety of postoperative complications, such as wound dehiscence, infections, reaccumulation of ascites, and death. ^, Nutritional status should be evaluated preoperatively; when found to be deficient, efforts should be undertaken to improve it (see Chapter 26 ).

Classically, cirrhotic patients were thought to be in a hypocoagulable state due to impaired hepatic synthesis of clotting factors, decreased vitamin K stores, thrombocytopenia and abnormal laboratory tests of coagulation such as prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time. The literature now supports a hypothesis of “rebalanced hemostasis” due to concomitant decreases in both procoagulant and anticoagulant proteins. Thrombocytopenia is compensated by increases in von Willebrand factor and factor VIII levels. These alterations are not detected on standard laboratory measures of coagulation parameters. Moreover, when spontaneous bleeding does occur, it is usually of hemodynamic origin due to the presence of portal hypertension. In the operating room, careful tissue handling and the maintenance of a low central venous pressure are other factors that can help to minimize blood loss. Direct measurements of clot formation, propagation, and fibrinolysis, such as thromboelastography, have proven useful in limiting blood product utilization during liver transplantation and may be helpful in reducing bleeding in other situations. If significant bleeding arises, administration of cryoprecipitate, diamino-8- d -arginine vasopressin, antifibrinolytics, or recombinant factor VIIa may be necessary to reverse coagulopathy and control hemorrhage.

In the perioperative period, altered mental status in a cirrhotic patient should be thoroughly evaluated. Only after all other potential causes have been ruled out can hepatic encephalopathy be reliably diagnosed. Lactulose should be administered and titrated for three soft bowel movements a day. Rifaximin has been shown to effectively reverse hepatic encephalopathy, and concomitant administration with lactulose was found to be more effective than lactulose alone in a randomized trial of encephalopathic patients. Postoperatively, the administration of narcotics and other sedating medications should be kept to a minimum. There is no role for prophylactic lactulose therapy for asymptomatic cirrhotic patients undergoing surgery (see Chapter 77 ).

Perioperative fluid management in cirrhotic patients can be very difficult. Patients with cirrhosis should be adequately resuscitated to avoid hypotension and hepatic ischemia, but fluids should also be given judiciously to minimize bleeding attributable to portal hypertension and the accumulation of ascites postoperatively. One center that performs a large volume of surgery on patients with end-stage liver disease limits the infusion of crystalloid solutions in the perioperative period. Instead, all patients with advanced liver disease are placed on a postoperative sodium-poor albumin drip until they can resume oral intake. Albumin infusion has been shown to have a number of beneficial effects in cirrhotic patients beyond simple volume expansion and increase in plasma oncotic pressure. It reduces mortality in patients with spontaneous bacterial peritonitis; improves outcome following large-volume paracentesis; and, in combination with vasoconstrictors, is useful in the management of hepatorenal syndrome. These effects of exogenous albumin are due to volume expansion, immunomodulation, and endothelial stabilization through increase in the effective albumin concentration.

Ascites increases the risk of postoperative renal failure, infections, and wound dehiscence. Even if ascites is drained at the time of surgery, it rapidly reaccumulates in the postoperative period. Medical therapy, which includes salt restriction and diuretics, is typically considered the first line of treatment. TIPS, however, may be considered a first-line treatment for refractory ascites and may be placed before elective surgery to help control ascites throughout the entire perioperative period. Moreover, TIPS may also reduce the risk of significant perioperative bleeding. In one of the largest series on the use of TIPS in patients undergoing major extrahepatic surgery, 25 cirrhotic patients with a mean MELD score of 15 ± 7.6 underwent TIPS at a median of 20 days before major abdominal and cardiothoracic operations. Blood transfusions were relatively minimal in the series, with a median of 3 units for abdominal operations (range, 0–21) and 4 units for cardiothoracic operations (range, 0–20). With a median follow-up of 33 months, actuarial 1-year patient survival was 74%, and the three postoperative deaths in the series occurred in patients with MELD scores higher than 24, all of whom underwent emergent surgery. Studies that compare outcomes after surgery with preoperative TIPS placement versus those with no TIPS, however, are lacking. Also, the optimal time interval between TIPS placement and elective surgery is unclear, but it is common for a period of several weeks to be required to see a clinical improvement in ascitic volume after TIPS; therefore shunts should probably be placed several weeks before planned operations (see Chapter 85 .

Specific procedures