Should Routine Liver Biopsy Be Considered in Bariatric Surgical Practice? An Analysis of the Limitations of Non-Invasive Nafld Markers

Abstract

Background Non-invasive markers are useful and practical tools for assessing non-alcoholic fatty liver disease (NAFLD), but liver biopsy remains the gold-standard method. Liver biopsy can be easily obtained on individuals undergoing bariatric surgery, but there is no ultimate evidence on the relationship between costs, risks and benefits of its systematic performance. Objective To compare the diagnostic accuracy of non-invasive methods with liver biopsy for detection and staging of NAFLD in obese individuals undergoing bariatric surgery. Methods This is a cross-sectional, observational and descriptive study which enrolled individuals who underwent bariatric surgery from 2018 through 2019 at a public tertiary university hospital. Ultrasound scan, hepatic steatosis index, Clinical Non-Alcoholic Steatohepatitis Score (C-NASH), hypertension, alanine aminotransferase (ALT) and insulin resistance (HAIR), aspartate aminotransferase (AST) to Platelet Ratio Index (APRI), NAFLD Fibrosis Score (NFS) and body mass index, AST/ALT ratio, and diabetes (BARD) were the methods compared with the histopathological examination of wedge liver biopsies collected during surgery. Results Of 104 individuals analyzed, 91 (87.5%) were female. The mean age was 34.9±9.7 years. There was no biopsy-related morbidity. The respective overall accuracies of each marker analyzed were: ultrasound scan (79.81% for steatosis), hepatic steatosis index (79.81% for steatosis), HAIR (40.23% for steatohepatitis), C-NASH (22.99% for steatohepatitis), APRI (94.23% for advanced fibrosis), NFS (94.23% for advanced fibrosis), and BARD (16.35% for advanced fibrosis). Discussion Given the high prevalence of liver disease within this population, even the most accurate markers did not present enough discretionary power to detect and/or rule out the NAFLD aspects they were designed to assess in comparison with liver biopsy, which is safe and easy to obtain in these patients. Conclusion Wedge liver biopsy during bariatric surgery helps to diagnose and stage NAFLD, presents low risks and acceptable costs; given the limitations of non-invasive methods, it is justifiable and should be considered in bariatric routine.

Impact of pre-operative weight loss on non-alcoholic fatty liver disease histopathology and insulin resistance in individuals undergoing bariatric surgery: a propensity matched cross-sectional comparison

“…Liver biopsy, in addition to promoting early diagnosis of both NAFLD and severe forms, such as liver cirrhosis, helps to understand the natural evolution of the disease and its postoperative course. 36,37 CONCLUSION Individuals undergoing pre-operative WL presented with significantly lower frequencies of macro-and microvesicular steatosis and portal inflammation, as well as lower blood glucose levels, compared to a group with no pre-operative WL matched by sex, age, and BMI, indicating an association between the recent trajectory of body mass and histological aspects of NAFLD and pointing to the highly dynamic and responsive WL features of this disease.…”

Estudio de la prevalencia y factores asociados a la Enfermedad por hígado graso no alcohólico en pacientes obesos mórbidos sometidos a Cirugía bariátrica

“…Cabe destacar la ausencia de mortalidad asociado a la cirugía entre 41 pacientes con cirrosis a los que se les practicó una gastrectomía en manga (243) Los individuos con indicación de cirugía bariátrica suelen presentar factores de riesgo cardiovascular en el contexto de un SM y es frecuente el hallazgo de depósito anormal de grasa en el hígado, constituyendo así una población de alto riesgo de presentar EHGNA. Por ello, la posibilidad de un diagnóstico precoz y previo a la cirugía de la obesidad de EHGNA podría conllevar beneficios relevantes, como una valoración de los riesgos/indicación de la cirugía bariátrica, el pronóstico y la evolución de la enfermedad (244).…”

“…El índice no invasivo de esteatosis HSI presentó en nuestro estudio menor área bajo la curva que los otros índices de esteatosis, comparado con biopsia y por lo tanto una menor especificidad y sensibilidad, datos similares a los observados en el estudio de Concon et al, donde los resultados de la puntuación HSI para la detección de esteatosis (en pacientes obesos candidatos a cirugía bariátrica) demostraron una alta sensibilidad (99%), pero una baja especificidad (244). Lind et al, analizan el índice HSI en diferentes contextos, y concluyen que su precisión diagnóstica es mayor en las poblaciones de alto riesgo en comparación con las de bajo riesgo de esteatosis (245).…”

“…Otros estudios en poblaciones similares a la nuestra, difieren en los resultados obtenidos con el índice NFS, como describe Concon en su estudio, en el que el NFS mostró resultados similares a los del APRI, presentando una utilidad similar en la práctica clínica para descartar la fibrosis avanzada, pero también fallando en la detección de la fibrosis no significativa (244). Singh et al, en un estudio con 1.319 individuos con EHGNA demostrada por biopsia, observan que el NFS presenta una especificidad del 93% y una sensibilidad del 44% (250), lo que demuestra su escasa utilidad en una población de alto riesgo.…”