Variation between centers in technique and guidelines for liver biopsy

Endoscopic Ultrasound-Guided Liver Biopsy

Endoscopic ultrasound-guided liver biopsy (EUS-LB) has emerged as a safe and effective alternative to percutaneous and trans-jugular approaches for hepatic tissue acquisition. It has shown superior diagnostic yield for the targeted approach of focal lesions, less sampling variability, improved patient comfort, and safety profile. These advantages have contributed to the increased use of EUS-LB as a technique for obtaining liver tissue. In this review, we provide an update on the recent evidence of EUS-LB for the evaluation of liver disease.

Combination of quantitative hepatitis B core antibody (qHBcAb) and aspartate aminotransferase (AST) can accurately diagnose immune tolerance of chronic hepatitis B virus infection based on liver biopsy

BACKGROUND AND AIMS

Immune tolerance is defined as HBeAg positive, high hepatitis B virus load (HBV), persistent normal alanine aminotransferase (ALT), no or slight inflammation or fibrosis in liver histology. However, it is still unclear the threshold of high hepatitis B virus load and how to predict histology without liver biopsy. The aim of this study was to predict immune tolerance in HBeAg positive, alanine aminotransferase -normal populations with non-invasive indicators.

METHODS

Two multi-center prospective cohort study recruited 907 treatment-naïve chronic hepatitis B (CHB) patients who had undergone liver biopsy in mainland China from August 2013 to September 2016 and April 2018 to June2019. Quantitative hepatitis B core antibody, AST and HBV DNA were investigated using commercial diagnostic assays and histological grading and staging was assessed by the Ishak scoring system.

RESULTS

One hundred and thirteen untreated CHB patients with HBeAg-positive, normal alanine aminotransferase (ALT) and high level of HBV DNA (≥5log10 IU/mL) were enrolled in this study. The area under the receiver operating characteristic curves (AUROCs) of qHBcAb, AST, HBV DNA and qHBcAb-AST index were 79.6%, 80.5%, 76.4% and 87.7%. Our novel qHBcAb-AST index, which combined qHBcAb and AST showed better performance with higher sensitivity (88.6% [95% confidence interval (CI) 72.3% - 96.3%]) and negative predictive value (NPV) (93.8% [95% CI 84.2% - 98.0%]).

CONCLUSIONS

The combination of qHBcAb and AST can more accurately predict the immune tolerance of people with HBeAg-positive, normal alanine aminotransferase (ALT).

Use of pethidine for percutaneous liver biopsy - a randomised, placebo-controlled, double blind study

BACKGROUND

Percutaneous liver biopsy (PLB) is the "gold standard" in the diagnosis of liver diseases. A pilot trial has shown pethidine may reduce anxiety and the need for post-procedural pain relief. The aim of this study was to investigate the role of pre-procedural pethidine.

METHODS

A double-blinded, randomized, placebo-controlled trial was conducted to assess the need for pethidine prior to PLB. 98 patients were randomly assigned to receive either 50 mg pethidine i.v. (n = 48), or an equal volume of 0.9% normal saline (n = 50). PLB was performed with ultrasound guidance after adequate local anaesthesia with xylocaine. Patients were asked to self-evaluate pain experienced using a visual analogue score (0-10) immediately and an hour after PLB. Patients were then followed up 24 hours after the procedure to assess their pain score, retrospective pain score and willingness to have a repeat procedure.

RESULTS

Pethidine administration resulted in significantly lower pain scores (0.60 ± 0.1 vs 1.2 ± 0.2, p = 0.006) and required less analgesia (0% vs 10%, p = 0.03) immediately after PLB in comparison to the placebo group. There was no significant difference in the pain score and analgesia requirement one hour after the procedure, the pain score at 24 hours after procedure and retrospective pain score. 94% of all patients of either group are willing to under go a repeat liver biopsy (NS).

CONCLUSIONS

The administration of pethidine routinely prior to PLB reduces the immediate post procedural pain but has no lasting effect and does not influence the patients' decision making process for future investigations.

TRIAL REGISTRATION

ACTRN12614001194651 , 13 November 2014.

Feasibility and experience of nurse-led ultrasound-guided percutaneous liver biopsy

The demand for collaborative and innovative clinical practitioners to act as leaders in healthcare remains strong as many challenges are faced including rising costs, shortage of professionals, the introduction of new technology and difficulties with access to care. Nurses in advanced nursing practice are well positioned to respond to this, playing a key role in building nursing knowledge, advancing the nursing profession and contributing to sustainable and effective healthcare systems. Percutaneous liver biopsy (PLB) is an essential tool used for diagnosis and management in liver disease, being most commonly performed by consultant gastroenterologists, hepatologists and radiologists. While invasive and with complications PLB is a simple, cost-effective procedure that can be undertaken at the bedside. Our study demonstrates that an advanced nurse practitioner (ANP) with a sound working knowledge of hepatology and familiarity with indications, methods and risks of PLB procedure can be trained to perform ultrasound-guided liver biopsy both safely and effectively.

Review article: the prothrombin time test as a measure of bleeding risk and prognosis in liver disease

BACKGROUND

Prothrombin time (PT)-derived international normalized ratio (INR) is used to assess bleeding risk and prognosis in cirrhosis, and to guide management of associated coagulation disturbances. Recent studies cast doubt on the validity of the assumptions that form the basis for these applications.

AIMS

To review and critique the use of the PT-INR in cirrhosis.

METHODS

Search of the literature.

RESULTS

In cirrhosis, there is a decrease in both pro- and anti-coagulants. The PT-INR measures only the activity of procoagulants and fails to capture changes in anticoagulants. It is therefore not surprising that the PT does not predict the bleeding risk. The PT-INR provides a robust measure of liver function but recent data showed INR inter-laboratory variability in this setting. This is not surprising as the INR was validated to normalize results for patients on vitamin-K antagonists, not for cirrhosis. This limitation was not appreciated, but the INR is used to construct the model for end-stage liver disease score to prioritize patients for liver transplantation. Reports showed that model for end-stage liver disease is modified by the thromboplastin used for testing.

CONCLUSIONS

Alternate tests to predict bleeding risk should be developed. The potential for misuse of the PT-INR should drive the development of alternate algorithms for organ allocation.

Abnormalities of hemostasis in chronic liver disease: reappraisal of their clinical significance and need for clinical and laboratory research

The derangement of hemostasis in patients with chronic liver disease has long been thought to be causally related to the bleeding events seen in these patients. However, the relatively poor correlation between bleeding and the peripheral indices of hemostasis together with the recent findings of the literature that thrombin generation as well as platelet adhesion are normal in these patients challenge this concept and question the usefulness of conventional tests in assessing the hemorrhagic risk, as well as the appropriateness of therapeutic strategies meant to correct abnormal hemostasis tests. This article reviews the abnormalities of primary hemostasis (interaction between platelets and vessel wall), coagulation (thrombin generation) and fibrinolysis in patients with chronic liver disease and proposes areas needing further clinical and laboratory research.

Thrombin generation in patients with cirrhosis: the role of platelets

Coagulation factor defects, thrombocytopenia, and thrombocytopathy are associated with cirrhosis. However, bleeding in patients who have cirrhosis does not entirely correlate with abnormal coagulation tests. Recently, it was shown that because of the concomitant abnormalities of the procoagulant and anticoagulant drives, thrombin generation in plasma patients with cirrhosis is normal when assessed with assays that include thrombomodulin (the main protein C activator). However, thrombin is also generated in vivo as a function of platelets, suggesting that thrombocytopenia and thrombocytopathy might affect thrombin generation in patients with cirrhosis. We addressed this issue using an assay that accounts for the contribution of plasma and platelets. The study showed that platelet-rich plasma with platelets adjusted by dilution of autologous platelet-rich into autologous platelet-poor plasma to a standard count (100 x 10(9)/L) generates as much thrombin in patients with cirrhosis as in controls (1,063 nmol/L vs. 1,167 nmol/L; P value not significant). When platelets were adjusted to correspond to whole-blood counts, patients with cirrhosis generated significantly less thrombin than controls (949 nmol/L vs. 1,239 nmol/L; P < .001). Furthermore, thrombin generation correlated with platelet numbers (rho = 0.50; P < .001). In addition, the amount of thrombin generated as a function of the whole-blood patients' platelet counts increased significantly when the numbers were adjusted to 100 x 10(9)/L (953 nmol/L vs.1,063 nmol/L; P < .001). In conclusion, severe thrombocytopenia may limit thrombin generation in patients with cirrhosis. These findings might justify platelet transfusion in patients with low platelet counts when they bleed spontaneously or before undergoing surgery or liver biopsy. Controlled clinical trials supporting this indication are warranted.

Hemostatic defects in end stage liver disease

End stage liver disease results in a complex and variably severe failure of hemostasis that predisposes to abnormal bleeding. The diverse spectrum of hemostatic defects includes impaired synthesis of clotting factors, excessive fibrinolysis, disseminated intravascular coagulation, thrombocytopenia, and platelet dysfunction. Hemostasis screening tests are used to assess disease severity and monitor the response to therapy. Correction of hemostatic defects is required in patients who are actively bleeding or require invasive procedures. Fresh frozen plasma, cryoprecipitate, and platelet transfusion remain the mainstays of therapy until larger trials confirm the safety and efficacy of recombinant factor VIIa in this population.

Influence of operator experience on performance of ultrasound-guided percutaneous liver biopsy

The purpose was to evaluate the influence of radiologist's experience on the diagnostic yield and complications of a percutaneous liver biopsy (PLB) method. Six hundred patients underwent an ultrasound-guided PLB by an inexperienced operator in 25.2% of cases (experience of less than 15 percutaneous liver biopsies performed alone--group I) or by an experienced operator (experience of more than 150 percutaneous liver biopsies--group II). The two groups were well-matched with respect to sex, age, percentage with viral hepatitis without histological cirrhosis, number of needle passes, history of liver biopsy and pain before the biopsy. A histological diagnosis was available in 97.3% of cases without any significant difference between the two groups ( P=0.25). However, group II samples were significantly longer and contained more portal tracts ( P=0.01). Pain was mild immediately and 6 h after the biopsy, without significant difference between both groups. Eight vasovagal reactions (five in group II) and one arteriobiliary fistula (in group II) occurred. With the method of PLB used for this study, operator's experience did not influence either the final histological diagnosis or the degree of pain suffered.

Controversies in liver biopsy: who, where, when, how, why?

Liver biopsy continues to have a central role in the evaluation of patients with suspected liver disease. The procedure is often indicated to evaluate otherwise unexplained liver biochemical test abnormalities, but the precise degree of serum aminotransferase elevations that should prompt a liver biopsy is controversial, as is the need for liver biopsy in all patients with suspected nonalcoholic fatty liver disease and chronic hepatitis C. Standard liver biopsy is contraindicated in patients with severe coagulopathy and ascites, although the degree of coagulopathy that contraindicates a liver biopsy is controversial. A transjugular approach is an alternative in patients with coagulopathy or ascites. Controversy surrounds all the technical aspects of liver biopsy, particularly the choice of needle (cutting vs suction) and the use of ultrasound to mark or guide the biopsy site. Bleeding is the major complication of liver biopsy, with a risk of 0.3%; cutting needles are more likely to cause hemorrhage than are suction needles. Traditionally, liver biopsy has been the province of the hepatologist/ gastroenterologist. However, an increasing number of liver biopsies are performed by radiologists. The implications of this trend with respect to patient outcome, safety, and training of fellows is unclear.

Recombinant activated factor VII (rFVIIa) as a hemostatic agent in liver disease: a break from convention in need of controlled trials

The management of coagulopathy in patients with acute and chronic liver disease has undergone little change in many years despite advances in our understanding of the pathogenesis of this problem. In general, deficiency of clotting factors as a result of poor hepatic synthetic function accounts for most of the coagulopathy. However, other processes such as disseminated intravascular coagulation (DIC), hyperfibrinolysis, dysfibrinogenemia, hemolysis, and a decrease in number or function of platelets may be present and thus add to the complexity of the problem. Coexisting portal hypertension and the associated risks of volume expansion, renal failure, and endothelial dysfunction add even more difficulty to the management of these patients. The clinician's despair is only exacerbated by uncertainty regarding the significance of laboratory indices of coagulation and the lack of agreement between health care providers regarding how to use these indices. Simple, conventional interventions such as vitamin K or plasma administration often produce only limited amelioration, and the latter carries the potential disadvantage of volume overexpansion as well as the risk of infection and transfusion reactions. Into this complex and uncertain clinical situation has arrived the antihemophilic agent recombinant activated factor VII (rFVIIa). Its development has led to a fundamental re-evaluation of the classic understanding of the normal clotting cascade. Moreover, use of this product in liver disease patients is increasing despite the lack of definitive studies or literature to guide therapy. Herein we review the mechanism of action of this agent, report the clinical applications in patients with liver disease, address the limitations and risks associated with the drug, and discuss the issue of its cost-effectiveness.

A survey of current liver biopsy practice patterns

GOALS

To survey clinicians regarding current liver biopsy practice patterns.

BACKGROUND

Although the hepatitis C epidemic has increased the proportion of hepatology in general gastroenterology practice, many clinicians express concern regarding the risks of percutaneous liver biopsy.

STUDY

A questionnaire about liver biopsy practices was sent to members of the Duke University Digestive Epidemiological Studies Consortium.

RESULTS

The response rate was 112 (71%) of 157. Thirty-three (29.5%) physicians reported that they do not perform liver biopsies. Reasons cited for not performing biopsies included concern about risks (72.7%), low reimbursement (66.7%), and logistical issues with space and recovery time (45.4%). Routine practice was biopsy without ultrasound in 53.2%, ultrasound marking by a radiologist or technician at the time of biopsy in 24.0%, previous ultrasound marking in 17.7%, and ultrasound marking by the gastroenterologist in 5.1%. For patients with hepatitis C, 76.8% of clinicians perform routine biopsies before treatment.

CONCLUSIONS

A significant proportion of clinicians do not perform liver biopsies; common reasons include the risks of the procedure and the low reimbursement. The use of ultrasound with liver biopsy has become more common. New approaches, especially in training programs, may be necessary to make clinicians more comfortable with this procedure.

Patient-administered nitrous oxide/oxygen inhalation provides safe and effective analgesia for percutaneous liver biopsy: a randomized placebo-controlled trial

OBJECTIVE

Although percutaneous liver biopsy (PLB) can be a painful procedure, common practice has not included intravenous sedation or analgesia. Patient-administered nitrous oxide/oxygen (N2O/O2) inhalation has demonstrated analgesic efficacy in various procedures associated with mild to moderate pain. The aim of this study was to investigate the safety and efficacy of analgesia with N2O/O2 inhalation for PLB.

METHODS

One hundred consecutive patients undergoing a first PLB (for chronic hepatitis C: 56, for alcoholic liver disease: 23, for miscellaneous reasons: 21). Patients were randomly assigned to self-administrate from a facial mask with a demand valve, for 5 min before and during biopsy, either a breathing mixture of 50% N2O/O2 (N2O group, n = 51), or a breathing oxygen placebo (P group, n = 49). Liver biopsy was performed at bedside after adequate local anesthesia with xylocaine. At the end of the procedure, patients were asked to self-evaluate pain experienced using a visual analogue scale (VAS) with scoring from 0 to 100 mm.

RESULTS

N2O/O2 administration resulted in the absence of pain in a significantly higher number of patients treated than in patients of the P group: 19 versus 2, respectively (p = 0.0001). Patients receiving N2O/O2 had significantly lower pain scores than those of the P group: 12+/-12 versus 28+/-19 mm (p < 0.0001). No serious complication was observed. Side effects of N2O/O2 were minor and reversible. The average cost per biopsy was 4 US dollars.

CONCLUSIONS

Patient-administered N2O/O2 inhalation provides safe and effective analgesia, at a reasonable cost, for PLB. Its routine use could be useful for the management of patients with chronic liver disease undergoing PLB as it may enhance patients compliance with future biopsies.