Routine Liver Biopsy During Bariatric Surgery: an Analysis of Evidence Base

Compare the Combined Diagnostic Accuracy of Transient Elastography and Visual Liver Score in Assessing Non-Alcoholic Fatty Liver Disease (NAFLD) and Compare it with Liver Biopsy in Morbidly Obese Patients Undergoing Bariatric Surgery: An Observational Study

INTRODUCTION

A liver biopsy is the gold standard for the diagnosis of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). Here, we combine preoperative transient elastography (TE) and intraoperative standardized visual liver score (VLS) which is compared with intraoperative liver biopsy for prediction of NAFLD and NASH in patients undergoing bariatric surgery.

AIM

Evaluate the combined diagnostic accuracy of TE and VLS in assessing NAFLD or NASH and compare it with liver biopsy in patients undergoing bariatric surgery.

METHODS

In a prospective cohort of 70 morbidly obese undergoing bariatric surgery, preoperative TE and intraoperative VLS were calculated. Findings of TE and VLS were compared with histology from intraoperative liver biopsy.

RESULTS

Histologically, 44 (62.85%) had NAFLD (≥ S1). Significant steatosis was seen in 20 (28.57%) while significant fibrosis was visible in 18 (25.71%). Area Under the Receiver Operating Characteristics (AUROC) TE for diagnosis of NAFLD was excellent (0.844, p = 0.001). At the optimal cutoff of 8.1, the positive predictive value (PPV) was 92.9%, and diagnostic accuracy was 90.6%. VLS had a sensitivity of 90.9% for NAFLD. The combined sensitivity of TE + VLS was 95.5% for ruling out NAFLD. Fourteen (20%) had NASH. VLS had a diagnostic accuracy of 97% in identifying NASH in comparison to TE. AUROC-VLS was 0.987, p ≤ 0.001, and a sensitivity of 100%. The overall sensitivity of combined TE and VLS was 100% with a negative predictive value (NPV) of 100%.

CONCLUSION

TE when combined with intraoperative VLS is comparable to liver biopsy and can be used for the diagnosis of NAFLD and NASH in patients undergoing bariatric surgery.

de Moraes T, Fragoso GR. Prospective Study to Analyze the Concordance Between a Standardized Visual Method With Pathology to stratify Nonalcoholic Fatty Liver Disease in Cadaveric Liver Grafts Evaluated for Transplantation

Background

The main challenge of liver transplantation is the discrepancy in demand and availability. Marginal grafts or full organs from donors with expansion criteria have been considered to reduce the shortage and assist a greater number of patients. Nonalcoholic fatty liver disease (NAFLD) is one of the most important defining criteria for expanded criteria organs. The present study proposes that an organized visual analysis method could correctly identify and classify NAFLD and organ viability without the need for liver biopsy and its logistical concerns.

Methods

Pictures from the grafts were taken at a standardized method (same distance, light conditions, and register device) before and after the perfusion. The visual liver score (VLS) was applied by transplant surgeons; biopsies of the grafts were analyzed by a pathologist in a double-blind design. Score performance and interobserver agreement for NAFLD detection and grading, as graft viability evaluation, were calculated.

Results

Fifty-seven grafts were analyzed. At least 1 previous expansion criterion was presented by 59.64% of donors. The prevalence of NAFLD was 94.73%, with 31.57% borderline nonalcoholic steatohepatitis and 5.26% nonalcoholic steatohepatitis. Steatosis was identified with 48.68% (preperfusion) and 64.03% (postperfusion) accuracy. NAFLD stratification was performed with 49.53% (preperfusion) and 46.29% (postperfusion) accuracy. Viability related to NAFLD was identified with 51.96% (preperfusion) and 48.52% (postperfusion) accuracy. Interobserver agreement was moderate for total VLS and poor for individual components of VLS.

Conclusions

Although a standardized method was not reliable enough for visual evaluation of NALFD compared with pathology, efforts should be made to expand access to biopsy. Further studies are needed to understand whether the VLS needs to be adapted or even excluded in the liver transplant scenario, to assess the importance of ectoscopy related to posttransplant clinical outcomes, and to determine its role in graft selection.

Bariatric surgery for non-alcoholic fatty liver disease: Indications and post-operative management

The prevalence of obesity and metabolic consequences such as nonalcoholic fatty liver diseases (NAFLD) has become a crucial health problem. Lifestyle modifications, especially weight loss, effectively reduces liver injury in NAFLD patients. However, adherence to lifestyle changes is very low in the clinical setting. Bariatric surgery can improve metabolic components and cause long-term weight loss. Therefore, bariatric surgery could serve as an attractive treatment option for NAFLD patients. This review integrates data about the benefits of bariatric surgery on NAFLD but also describes the potential pitfalls.

American Association of Clinical Endocrinology Clinical Practice Guideline for the Diagnosis and Management of Nonalcoholic Fatty Liver Disease in Primary Care and Endocrinology Clinical Settings: Co-Sponsored by the American Association for the Study of Liver Diseases (AASLD)

OBJECTIVE

To provide evidence-based recommendations regarding the diagnosis and management of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) to endocrinologists, primary care clinicians, health care professionals, and other stakeholders.

METHODS

The American Association of Clinical Endocrinology conducted literature searches for relevant articles published from January 1, 2010, to November 15, 2021. A task force of medical experts developed evidence-based guideline recommendations based on a review of clinical evidence, expertise, and informal consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RECOMMENDATION SUMMARY

This guideline includes 34 evidence-based clinical practice recommendations for the diagnosis and management of persons with NAFLD and/or NASH and contains 385 citations that inform the evidence base.

CONCLUSION

NAFLD is a major public health problem that will only worsen in the future, as it is closely linked to the epidemics of obesity and type 2 diabetes mellitus. Given this link, endocrinologists and primary care physicians are in an ideal position to identify persons at risk on to prevent the development of cirrhosis and comorbidities. While no U.S. Food and Drug Administration-approved medications to treat NAFLD are currently available, management can include lifestyle changes that promote an energy deficit leading to weight loss; consideration of weight loss medications, particularly glucagon-like peptide-1 receptor agonists; and bariatric surgery, for persons who have obesity, as well as some diabetes medications, such as pioglitazone and glucagon-like peptide-1 receptor agonists, for those with type 2 diabetes mellitus and NASH. Management should also promote cardiometabolic health and reduce the increased cardiovascular risk associated with this complex disease.

Routine Versus Selective Liver Biopsy During Bariatric Surgery: Postoperative Outcomes and Preoperative Predictors of NASH

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is common in patients with obesity. Liver biopsy (LB) can be routinely or selectively performed during bariatric surgery to identify patients with NASH.

METHODS

Patients undergoing bariatric surgery between 2016 and 2020 at our institution were identified. Chart review identified patients undergoing concurrent LB. LB results were compared between patients undergoing routine LB and selective LB. Patient demographics and postoperative outcomes were compared between those who received LB and those who did not (non-LB). In the LB cohort, preoperative characteristics of patients with NASH were compared to those without NASH, and multivariable regression was used to identify predictors of NASH.

RESULTS

Two thousand three hundred ninety-three patients were identified, of which 400 (16.7%) had liver biopsies (LB) and 1,993 (83.3%) did not (non-LB). Three hundred thirty LB were performed routinely, and 70 were selective. Compared to selective LB, routine LB identified significantly higher rates of steatosis (83.6% vs. 4.5%, p < 0.01), periportal inflammation (67.0% vs. 3.2%, p < 0.01), fibrosis (65.8% vs. 2.1%, p < 0.01), and NASH (10.9% vs. 1.5%, p < 0.01). There were no differences in postoperative complications, blood transfusions, readmissions, or reoperations between LB and non-LB. On multivariable regression, highest BMI > 40 (OR 2.85, 95% CI 1.43-5.67) and insulin-dependent diabetes (OR 4.83, 95% CI 1.70-13.69) were associated with a higher odds of NASH, while Black race was associated with lower odds (OR 0.25, 95% CI 0.09-0.65).

CONCLUSIONS

Routine liver biopsies during bariatric surgery identify higher rates of advanced NAFLD compared to selective biopsies, and can be safely performed without an increased risk of postoperative complications.

Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity

Background

Vibration controlled transient elastography (VCTE) and controlled attenuation parameter (CAP™) have shown reliable performance predicting fibrosis and steatosis in normal- to overweight patients but have not been validated in severe to morbid obesity. This study aimed at determining the accuracy of VCTE, CAP™ and the composite score FibroScan-AST (FAST) in patients with a body mass index (BMI) of ≥35 kg/m².

Methods

Patients scheduled for bariatric-metabolic surgery underwent preoperative VCTE/CAP™ measurement, and intraoperative liver biopsy. The feasibility and accuracy of VCTE, CAP™ and the composite score FAST were retrospectively analysed to evaluate fibrosis, steatosis and active fibrotic non-alcoholic steatohepatitis [NASH + non-alcoholic fatty liver disease (NAFLD) activity score ≥4 + fibrosis grade ≥2] using per protocol (PP) and intent to diagnose (ITD) calculation.

Results

In total, 170 patients (median BMI 44.4 kg/m²) were included in the study. Liver biopsy showed NASH, simple steatosis, and normal livers in 60.6% (n=103), 28.8% (n=49), and 10.6% (n=18), respectively. VCTE and CAP™ delivered reliable results in 90.6% (n=154/170) and 90.5% (n=134/148). The AUC (PP) of VCTE, CAP™, and FAST were 0.687 (≥F2), 0.786 (≥F3), 0.703 (≥S2), 0.738 (S3), and 0.780 (active fibrotic NASH). The AUC increased to 0.742 (≥F2), 0.842 (≥F3), 0.712 (≥S2), 0.780 (S3), and 0.836 (active fibrotic NASH) in patients below the median BMI of 44.4 kg/m².

Conclusions

VCTE, CAP™ and FAST show acceptable accuracy for the detection of fibrosis, steatosis and NASH in a real-life cohort of patients with obesity. Accuracy improves in patients with a BMI <44.4 kg/m².

Impact of Nonalcoholic Steatohepatitis on the Outcome of Patients Undergoing Roux-en-Y Gastric Bypass Surgery: a Propensity Score-Matched Analysis

Purpose

It is currently unknown whether NASH (nonalcoholic steatohepatitis), as compared to simple steatosis, is associated with impaired postoperative weight loss and metabolic outcomes after RYGB surgery. To compare the effectiveness of Roux-en-Y gastric bypass (RYGB) on patients with NASH versus those with simple nonalcoholic fatty liver (NAFL).

Materials and Methods

We retrospectively retrieved data from 515 patients undergoing RYGB surgery with concomitant liver biopsy. Clinical follow-up and metabolic assessment were performed prior to surgery and 12 months after surgery. We used multivariate analysis of variance (MANOVA) and propensity score matching and we assessed for changes in markers of hepatocellular injury and metabolic outcomes.

Results

There were 421 patients with simple NAFL, and 94 with NASH. Baseline alanine and aspartate aminotransferases were significantly higher in patients with NASH (p < 0.01). Twelve months after the RYGB surgery, as determined by both MANOVA and propensity score matching, patients with NASH exhibited a significantly greater reduction in alanine aminotransferase (ß-coefficient − 12 iU/l [− 22 to − 1.83], 95% CI, adjusted p = 0.021) compared to their NAFL counterparts (31 matched patients in each group with no loss to follow-up at 12 months). Excess weight loss was similar in both groups (ß-coefficient 4.54% [− 3.12 to 12.21], 95% CI, adjusted p = 0.244). Change in BMI was comparable in both groups (− 14 (− 16.6 to − 12.5) versus − 14.3 (− 17.3 to − 11.9), p = 0.784).

Conclusion

After RYGB surgery, patients with NASH experience a greater reduction in markers for hepatocellular injury and similar weight loss compared to patients with simple steatosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05642-0.

The role of bariatric surgery in the management of nonalcoholic steatohepatitis

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in the United States and increasing globally. The progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), can lead to cirrhosis and complications of end-stage liver disease. No FDA-approved therapy for NAFLD/NASH exists. Treatment of NAFLD/NASH includes effective and sustained life-style modification and weight loss. This review reports on the recent findings of bariatric surgery in the management of NASH.

RECENT FINDINGS

NAFLD, at all stages, is common in those who meet indication for bariatric surgery. Bariatric surgery resolves NAFLD/NASH and reverses early stages of fibrosis. Although randomized controlled trials of bariatric surgery in NASH are infeasible, studies defining the metabolic changes induced by bariatric surgery, and their effect on NASH, provide insight for plausible pharmacologic targets for the nonsurgical treatment of NASH.

SUMMARY

Resolution of NASH and fibrosis regression can occur after bariatric surgery. Although the exact mechanism(s) underlying the improvement of NASH and hepatic fibrosis following bariatric surgery is not fully elucidated, emerging data on this topic is vitally important for lending insight into the pharmacotherapies for NASH for patients who are not otherwise suitable candidates for bariatric surgery.

Factors that make Bariatric Surgery Technically Challenging: A Survey of 370 Bariatric Surgeons

BACKGROUND

There is no published data on the factors bariatric surgeons think make bariatric surgery challenging. This study aimed to identify factors that bariatric surgeons feel and increase the technical complexity of bariatric surgery.

METHODS

Bariatric surgeons from around the world were invited to participate in a questionnaire-based survey on Survey Monkey®. An Average Weighted Score was calculated for each factor. A score of < 1.0 meant that the factor was perceived to make surgery technically easier.

RESULTS

Three hundred seventy bariatric and metabolic surgeons from 59 countries completed the survey. The top 10 factors that our respondents felt were most important for determining the technical difficulty of a procedure were inappropriate trocar placement (AWS 3.44), BMI above 60 (AWS 3.41), open bariatric surgery (AWS 3.26), less experienced bariatric anesthetist (AWS 3.18), liver cirrhosis (AWS 3), large liver (AWS 2.99), less experienced bariatric assistant (AWS 2.97), lower surgeon total bariatric surgery volume (AWS 2.95), lower surgeon specific procedure volume (AWS 2.85) and previous laparotomy (AWS 2.83), respectively. Respondents also felt that the younger patients (AWS 0.78), dedicated operating team (AWS 0.67), BMI less than 35 (AWS 0.54), and French position (AWS 0.45) actually make the surgery easier.

CONCLUSION

This survey is the first attempt to understand the factors which make bariatric surgery more difficult. Knowing the factors made the operation more challenging, led to better scheduling the potentially difficult patients to reduce the complications.

Decision Tree for the Performance of Intraoperative Liver Biopsy During Bariatric Surgery

BACKGROUND AND AIMS

Bariatric surgery provides a useful opportunity to perform intraoperative liver biopsy to screen for non-alcoholic steatohepatitis (NASH). There is currently no consensus on whether intraoperative liver biopsy should be systematically performed. The aim of this study was to develop and validate a decision tree to guide that choice.

APPROACH AND RESULTS

This prospective study included 102 consecutive patients from the severe obesity outcome network (SOON) cohort in whom liver biopsy was systematically performed during bariatric surgery. A classification and regression tree (CART) was created to identify the nodes that best classified patients with and without NASH. External validation was performed. Seventy-one biopsies were of sufficient quality for analysis (median body mass index 43.3 [40.7; 48.0] kg/m²). NASH was diagnosed in 32.4% of cases. None of the patients with no steatosis on ultrasound had NASH. The only CART node that differentiated between a "high-risk" and a "low-risk" of NASH was alanine aminotransferase (ALT). ALT>53IU/L predicted NASH with a positive predictive value (PPV) of 68% and a negative predictive value (NPP) of 89%, a sensitivity of 77%, and a specificity of 84%. In the external cohort (n=258), PPV was 68%, NPV was 62%, sensitivity was 27%, and specificity was 90%.

CONCLUSIONS

The present work supports intraoperative liver biopsy to screen for NASH in patients with ALT>53IU/L; however, patients with no steatosis on ultrasound should not undergo biopsy. The CART failed to identify an algorithm with a good sensitivity to screen for NASH in patients with ultrasonography-proven steatosis and ALT≤53IU/L.

Comparison between non-invasive methods and liver histology to stratify liver fibrosis in obese patients submitted to bariatric surgery

BACKGROUND

Obesity is a multifactorial disease characterized by fat accumulation, usually associated with non-alcoholic fatty liver disease, which can lead to advanced fibrosis or even cirrhosis. Bariatric surgery (BS) is a treatment approved for weight loss in morbidly obese patients. However, complications from this modality of treatment have been reported and liver cirrhosis connotes more risk procedure.

AIMS

Evaluate non-invasive methods transient elastography (THE) and scores to establish the degree of liver fibrosis in patients submitted to BS, comparing their performance with liver histology.

METHODS

We calculated liver fibrosis by non-invasive scores AST to platelet ration index (APRI), fibrosis-4 (FIB-4) and non-alcoholic fatty liver disease (NAFLD) score and THE before and 6 months after the bariatric surgery. The results were compared to liver histology.

RESULTS

We included 85 patients, 69.4% females, with a mean age of 36 years, with a mean body mass index (BMI) of 41 kg/m². The non-invasive scores were able to exclude clinically significant fibrosis in 85.9% (APRI) and advanced fibrosis in 96.5% (FIB-4) and 51.8% (NAFLD score). When comparing with the histological findings, the correlation with elastography was 45.9% for the same degree of fibrosis, with high negative predictive value (94.4%) in pre-surgical analysis. In the post-surgical analysis, the correlation with histology was 69.4% for THE and the negative predictive value to exclude clinically significant fibrosis was 98.5%.

CONCLUSION

THE showed low correlation with histology in the pre-surgical analysis. All the methods had better results in post bariatric evaluation comparing with pre-bariatric data and the non-invasive FIB-4 score showed the best of them.

Safety of liver biopsy at the time of bariatric surgery: an analysis of the MBSAQIP database

BACKGROUND

The majority of patients undergoing bariatric surgery have hepatic steatosis. Liver biopsy is not technically difficult to perform at the time of metabolic and bariatric surgery (MBS), but there may be concerns for bleeding complications. The safety of liver biopsy (LBx) at the time of MBS has been studied in single institutional studies but has not been studied on a national level.

METHODS

The MBSAQIP database for 2015-2018 was examined. The codes for Roux-en-Y gastric bypass (RYGB) of 43644 and sleeve gastrectomy (SG) 43775 were used along with 47000 (percutaneous liver biopsy), 47001 (percutaneous liver biopsy at time of other procedure), and 47379 (unlisted laparoscopic procedure, liver). Outcomes such as operative time, complications, and length of stay were examined. Propensity-matched analysis was performed to evaluate for adjusted associations.

RESULTS

There were 546,532 patients that met our inclusion criteria. Of those, 21,367 (3.9%) underwent LBx. Only 5.5% (8012) of patients undergoing RYGB had a LBx and 3.3% (13,355) of SG patients. Patients who underwent a LBx had a longer operative time before (103 min vs 84 min, p < 0.001) and after propensity matching [regression coefficient (RC): 10.7 (8.87, 12.5)]. There was no increase in length of stay. There was an increased risk in mortality in the unadjusted analysis (prevalence ratio = 1.61, p = 0.02), but when propensity-matched analysis was done, there was no statistically significant difference between the two groups. Concerning bleeding or transfusion, there was no difference in bleeding or rates of transfusion (p= 0.22, p = 0.21).

CONCLUSION

Liver biopsy at the time of MBS is safe. It adds operative time, but there is no increase in length of stay, bleeding complications, morbidity, or death.

Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

Liver biopsy is required when clinically important information about the diagnosis, prognosis or management of a patient cannot be obtained by safer means, or for research purposes. There are several approaches to liver biopsy but predominantly percutaneous or transvenous approaches are used. A wide choice of needles is available and the approach and type of needle used will depend on the clinical state of the patient and local expertise but, for non-lesional biopsies, a 16-gauge needle is recommended. Many patients with liver disease will have abnormal laboratory coagulation tests or receive anticoagulation or antiplatelet medication. A greater understanding of the changes in haemostasis in liver disease allows for a more rational, evidence-based approach to peri-biopsy management. Overall, liver biopsy is safe but there is a small morbidity and a very small mortality so patients must be fully counselled. The specimen must be of sufficient size for histopathological interpretation. Communication with the histopathologist, with access to relevant clinical information and the results of other investigations, is essential for the generation of a clinically useful report.

Safety and Utility of Liver Biopsy During Bariatric Surgery in the New Zealand Setting

BACKGROUND

Asymptomatic liver disease is common in bariatric patients and can be diagnosed with intraoperative biopsy. This study aimed to establish the risk-benefit profile of routine liver biopsy, prevalence of clinically significant liver disease, relationship between liver pathology and body mass index, and compare outcomes between ethnic groups.

METHODS

This retrospective cohort study included all patients who had index bariatric surgery at Auckland City Hospital between 2009 and 2016. Diagnosis of liver disease was based on intraoperative biopsy histology. Outcomes included safety (biopsy-related complication) and utility (liver pathology meeting criteria for referral). Liver pathology and referral rates were compared between ethnic groups.

RESULTS

Of 335 bariatric surgery patients, 234 (70%) underwent intraoperative liver biopsy. There were no biopsy-related complications. Histological findings were as follows: normal 25/234 (11%), non-alcoholic fatty liver disease (NAFLD) 207/234 (88%), and other pathological findings in 35/234 (15%). Histological finding meeting referral criteria was present in 22/234 (9%). Of these, 12/22 (55%) were referred. Number needed to biopsy to identify histology meeting referral criteria: n = 11. Māori had a similar NAFLD rate to non-Māori [51/56 versus 156/178, p = 0.48]. Pasifika patients had a higher rate than non-Pasifika [39/40 versus 168/194, p = 0.049]. Māori and Pasifika patients had similar referral rates to non-Māori and non-Pasifika [2/3 versus 5/9, p = 0.73; 2/2 versus 5/10, p = 0.19].

CONCLUSIONS

Intraoperative liver biopsy during bariatric surgery is safe and identified liver disease in 89%, with 9% meeting referral criteria. Pasifika patients have a higher rate of NAFLD than non-Pasifika.

Clinical relevance of liver histopathology and different histological classifications of NASH in adults

Nonalcoholic fatty liver disease (NAFLD) encompasses simple steatosis and steatohepatitis (NASH) with or without fibrosis/cirrhosis and hepatocellular carcinoma. NAFLD occurs epidemically in most areas of the world, contributes to cardiovascular events and liver-related mortality and therefore exacts a major economic toll. Areas covered: Here we summarize what clinicians should know about NAFLD histopathology in adults. We report on the individual histological features and scoring systems of NAFLD: the NAFLD activity score (NAS) introduced by the NASH-Clinical Research Network, the 'Fatty Liver Inhibition of Progression' algorithm and Steatosis, Activity, and Fibrosis (SAF) score. Pros and cons of histological classifications in NASH are discussed. Special emphasis is given to liver histopathology in some high-risk patient groups, such as those with severe obesity and type 2 diabetes. Moreover, we also examine the relationship between liver histopathology and clinical features, and the impact of liver histopathology on the long-term prognosis of NAFLD. Finally, we propose an integrated diagnostic approach which utilizes both non-invasive tools and liver biopsy in those individual patients with suspected NAFLD. Expert commentary: Based on expert opinions, we conclude with a research agenda on NAFLD which focuses on the most burning topics to be addressed over the next five years.

Monitoring of Liver Function Tests after Roux-en-Y Gastric Bypass: An Examination of Evidence Base

There is no consensus on the monitoring of liver function tests after Roux-en-Y gastric bypass (RYGB). Since the main objective of such monitoring would be to diagnose early those who will eventually develop liver failure after RYGB, we performed a systematic review on this topic. An extensive search of literature revealed only 10 such cases in 6 published articles. It would hence appear that liver failure is a rare problem after RYGB. Routine lifelong monitoring of liver function tests is therefore unnecessary for otherwise asymptomatic individuals. Such monitoring should hence be reserved for high-risk groups, such as patients with liver cirrhosis, those undergoing extended limb/distal RYGB, patients with new illnesses, those abusing alcohol, those on hepatotoxic drugs and those presenting with a surgical complication.

Liver Function in Patients With Nonalcoholic Fatty Liver Disease Randomized to Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy: A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVES

The aim of the study was to compare the influence of sleeve gastrectomy (SG) versus Roux-en-Y gastric bypass (RYGB) on liver function in bariatric patients with non-alcoholic fatty liver disease (NAFLD) in a randomized clinical trial (NCT01806506).

BACKGROUND

Rapid weight loss and malabsorption after bariatric surgery in patients with NAFLD or steatohepatitis (NASH) may impair liver function.

METHODS

Sixty-six morbidly obese patients randomized to SG or RYGB were included in a secondary outcome analysis. Intraoperative liver biopsies were categorized with NAFLD Activity Score (NAS) and liver function tests were done before surgery and after 1, 6 and 12 months.

RESULTS

NASH was present in 54.5% RYGB and 51.5% SG patients (P > 0.05). At 12 months excess weight loss was 68.7 ± 19.7% after SG and 62.8 ± 18.5% after RYGB (P > 0.05). At 1 month international normalized ratio (INR) increased after RYGB (0.98 ± 0.05 vs 1.14 ± 0.11; P < 0.05) and SG (0.99 ± 0.06 vs 1.04 ± 0.06; P < 0.05), RYGB induced significantly greater increase in INR in the whole group and NASH patients than SG. After RYGB albumin decreased at 1 month (41.2 ± 2.7 vs 39.0 ± 3.2 g/L; P < 0.05). At 12 months, INR and albumin returned to baseline. At 12 months in NASH group, SG induced significant improvement in aspartate aminotransferase (32.4 ± 17.4 vs 21.5 ± 6.9U/L), alanine aminotransferase (39.9 ± 28.6U/L vs 23.8 ± 14.1U/L), gamma-glutamyl transpeptidase (34.3 ± 16.6 vs 24.5 ± 16.8U/L), and lactate dehydrogenase (510.8 ± 33 vs 292.4 ± 29). Variables predictive of INR change after 1 month included operation type, NAS ≥ 5, bilirubin, body mass index, hemoglobin A1C, and dyslipidemia.

CONCLUSIONS

Patients with NASH undergoing RYGB are more susceptible to early transient deterioration of liver function than after SG.