Selection of Patients With Cirrhosis For Surgery: As Much An Art As Science
Authors: Douglas A. Simonetto, Vijay H. Shah, Patrick S. Kamath
Journal: Hepatology (2020)

Potential conflict of interest: Nothing to report. See Article on Page 204. "Art has a double face, of expression and illusion, just like science has a double face: the reality of error and the phantom of truth." René Daumal With improved life expectancy despite a rising prevalence of NAFLD and related comorbidities,(1) there has been an increase in the number of patients with cirrhosis requiring surgery. Surgical innovations and better patient selection over the past decade have contributed to better postoperative outcomes.(2) With more patients with cirrhosis being considered for surgery, assessment of postoperative risk is now an important aspect of hepatology practice. The decision regarding whether to subject a patient to surgery requires not only the use of prognostic tools based on science, but also patient and surgeon preferences, which are more based on art. This shared decision process depends on how much risk the patient and surgeon are willing to take. Some are more risk averse than others. Initial evaluation of the patient with cirrhosis who is a surgical candidate includes assessment of postoperative cardiovascular and respiratory failure risk and the American Society of Anesthesiologists (ASA) Physical Status classification. The risk for postoperative mortality and complications in patients with cirrhosis is related to the degree of hepatic dysfunction, HVPG,(3) type of comorbidity, complexity of the surgical procedure, and the expertise of the center in which the operation is carried out. There is no evidence that the type of anesthesia, whether regional or general, is predictive of perioperative risk. Liver disease severity is of utmost importance in predicting outcomes when comorbidity is minimal. On the other hand, when surgery is carried out in patients with near normal hepatic function, comorbidity may largely determine outcomes. The postoperative risk in patients with cirrhosis needs to be interpreted within this context. The first attempt at bringing science into selection of patients with cirrhosis was in the field of portosystemic shunt surgery. Three risk classes, A, B and C, were identified by Wantz and Payne.(4) Modifications of this score resulted in the Child class(5) and the Child‐Turcotte‐Pugh (CTP) score.(6) When extended to other types of intra‐abdominal surgery, patients of CTP Class A were considered low risk, whereas patients with CTP class C were high risk and CTP class B, intermediate risk. The CTP class was later supplanted by the Model for End‐Stage Liver Disease MELD score to assess liver disease severity.(7) Combining MELD score with age and the ASA class has predictive accuracy for postoperative mortality at 30 and 90 days and 1 year, independent of the type of surgical procedures carried out.(8) In the current issue of hepatology, Mahmud et al. used data from the Veterans Outcomes and Costs Associated with Liver Disease (VOCAL) cohort to develop and validate the VOCAL‐Penn model to predict postoperative mortality at 30, 90, and 180 days.(9) The cohort included 3,785 patients with cirrhosis between 2008 and 2016 who underwent a range of surgical interventions, including minimally invasive procedures. They demonstrated that the type of surgical procedure is predictive of postoperative mortality, with open abdominal surgery carrying the highest mortality risk. The VOCAL‐Penn model identified NASH as another risk factor for postoperative mortality. Paradoxically, the model identified obesity (body mass index ≥ 30) as a protective feature, a phenomenon increasingly recognized in critically and chronically ill patients.(10) Although NASH may serve as a surrogate for subclinical cardiovascular disease, obesity may be indicative of nutritional reserve required for postoperative healing. Thus, the addition of type of surgery and presence of NASH and obesity to markers of liver function (albumin and total bilirubin), portal hypertension (platelet count), and ASA class has resulted in a model with improved predictive performance. It is important to emphasize that similar to prior surgical prediction models, the VOCAL‐Penn model was derived from retrospective data. Factors including functional and nutritional status that deem patients as unsuitable surgical candidates have not been included. Although not specifically stated, it appears that CTP class and MELD scores were used to select patients for surgery. This is evident by the low median MELD score of the study population (most patients had MELD scores ≤ 9), in whom 88% of the patients were CTP class A; only 13% of patients had any ascites; and only 3% had HE. Given that patients selected for surgery were almost exclusively CTP class A and in a very narrow range of MELD scores, it is not surprising that these liver‐specific scores were not predictive of outcome. The VOCAL‐Penn model, therefore, is only applicable in patients with CTP class A cirrhosis and MELD score ≤ 9. The science of assessing surgical risk may use the CTP and MELD scores, and with the current publication, the VOCAL‐Penn model. The age‐old art of surgery relies on the surgeon's and hepatologist's experience in minimizing combinations of risk. This includes the "eyeball" assessment of nutritional status and frailty, factors that are not captured in mathematical models. The presence of portal hypertension is important for risk assessment for intra‐abdominal and technically challenging surgery, but may be less important for other types of surgery such as orthopedic surgery. Significant ascites and intra‐abdominal varices can dissuade the surgeon from proceeding with abdominal surgery, particularly if the patient has had a previous abdominal operation. Additionally, surgery may be avoided in patients who have social risk factors including alcohol use disorder. Independent of the technical surgical risk, but an important determinant of postsurgical outcome, is optimal management of cirrhosis‐related complications in the peri‐operative period. Whether rescue liver transplantation can be carried out and how closely centers are monitored for outcomes also determines how patients are selected. How can the information from the current study be used to select patients with cirrhosis for elective surgical procedures? The first step in patient selection involves assessment of bleeding and cardiopulmonary risk and frailty. After consideration of these factors, if the patient is deemed a possible candidate for surgery, predictive surgical risk scores should be factored into the decision‐making process. The ideal candidate for surgery is of CTP class A or with MELD score ≤ 9, and minimal comorbidity. Among these carefully selected patients, risk stratification provided by the VOCAL‐Penn model may allow for better selection of patients to undergo elective procedures, to improve quality of life and with possibly favorable long‐term outcomes. Incorporation of surgery type is a significant improvement that could also be factored into preoperative evaluation. The study by Mahmud et al. undoubtedly represents a step forward into the science of surgical risk assessment; however, selecting patients with cirrhosis for surgery still remains as much art as science.