Liver transplantation for bariatric surgery-related liver failure: a systematic review of a rare condition

Surgical risk stratification in patients with cirrhosis

Individuals with cirrhosis experience higher morbidity and mortality rates than the general population, irrespective of the type or scope of surgery. This increased risk is attributed to adverse effects of liver disease, encompassing coagulation dysfunction, altered metabolism of anesthesia and sedatives, immunologic dysfunction, hemorrhage related to varices, malnutrition and frailty, impaired wound healing, as well as diminished portal blood flow, overall hepatic circulation, and hepatic oxygen supply during surgical procedures. Therefore, a frequent clinical dilemma is whether surgical interventions should be pursued in patients with cirrhosis. Several risk scores are widely used to aid in the decision-making process, each with specific advantages and limitations. This review aims to discuss the preoperative risk factors in patients with cirrhosis, describe and compare surgical risk assessment models used in everyday practice, provide insights into the surgical risk according to the type of surgery and present recommendations for optimizing those with cirrhosis for surgical procedures. As the primary focus is on currently available risk models, the review describes the predictive value of each model, highlighting its specific advantages and limitations. Furthermore, for models that do not account for the type of surgical procedure to be performed, the review suggests incorporating both patient-related and surgery-related risks into the decision-making process. Finally, we provide an algorithm for the preoperative assessment of patients with cirrhosis before elective surgery as well as guidance perioperative management.

Revisional surgery for malnutrition after SADI-S: prevalence, indications, techniques and outcomes

KEY POINTS

SADIS with short common limb (< 250 cm) is a malabsorptive operation. Reoperation is advised in patients requiring admission for severe malnutrition. Elongation of the common channel is the preferred revisional technique Introduction: Single-Anastomosis Duodeno-Ileal bypass with Sleeve gastrectomy (SADI-S) is a modification of the duodenal switch. Initial common channel's length was 200, and after malnutrition was detected in some patients, it was elongated to 250 or 300 cm. The present study analyzes presentation and treatment of malnutrition after SADI-S.

MATERIALS

Three hundred and thirty-three consecutive patients undergoing SADI-S between May 2007 and February 2019 were included. The common limb length was 200 cm in 50 cases, 250 cm in 211, 300 in 71 and 350 in 1. Thirty-one patients were admitted for severe hypoalbuminemia and 17 patients were submitted to revisional surgery, and constitute the series of our study. Mean weight before reoperation was 57 kg and mean body mass index (BMI) was 21 kg/m2. Mean number of daily bowel movements was 5,6.

RESULTS

Mean time to reoperation was 56 months. The limb was found shorter than expected in 6 cases. Revisional surgery was conversion into a Roux en Y duodenal switch in 3 cases, elongation of the common limb in 11 patients, duodeno-duodenostomy in 1 and duodeno-jejunostomy to the first jejunal loop in 2. Mean weight regain was 14 kg, and mean final BMI 26 kg/m2. Daily bowel movements were reduced to 1,3. Factors related to hypoalbuminemia were hypertension, poor-controlled diabetes, shorter common limb and liver-test alterations.

CONCLUSION

SADI-S is expected to be less malabsorptive than previous biliopancreatic diversions. However, caution must be taken with certain patients to avoid postoperative malnutrition. Adequate follow up with long-term supplementation is required.

How best to combine liver transplantation and bariatric surgery?-Results from a global, web-based survey

BACKGROUND AND AIMS

Obesity is a growing healthcare challenge worldwide and a significant risk factor for liver failure as seen with non-alcoholic steatohepatitis (NASH). Combining metabolic-bariatric surgery (MBS) with liver transplantation (LT) appears as attractive strategy to treat both, the underlying liver disease and obesity. However, there is an ongoing debate on best timing and patient selection. This survey was designed to explore the current treatment practice for patients with NASH and obesity worldwide.

METHODS

A web-based survey was conducted in 2022 among bariatric and LT surgeons, and hepatologists from Europe, North and South America and Asia.

RESULTS

The survey completion rate was 74% (145/196). The average respondents were 41-50 years (38%), male (82.1%) and had >20 years of clinical experience (42.1%). Centres with a high LT-caseload for NASH were mainly located in the USA and United Kingdom. Almost 30% have already performed a combination of LT with MBS and 49% plan to do it. A majority of bariatric surgeons prefer MBS before LT (77.2%), whereas most of LT surgeons (52%) would perform MBS during LT. Most respondents (n = 114; 80%) favour sleeve gastrectomy over other bariatric techniques. One third (n = 42; 29.4%) has an established protocol regarding MBS for LT candidates.

CONCLUSION

The most experienced centres doing LT for NASH are in the USA and United Kingdom with growing awareness worldwide. Overall, a combination of MBS and LT has already been performed by a third of respondents. Sleeve gastrectomy is the bariatric technique of choice-preferably performed either before or during LT.

Bariatric surgery and liver transplantation, here we are now: A French nationwide retrospective study

At the time of the growing obesity epidemic worldwide, liver transplantation (LT) and metabolic syndrome are closely linked: non-alcohol-related fatty liver disease (NAFLD) is one of the leading indications for liver transplantation, and metabolic syndrome can also appear after liver transplantation, in relation to immunosuppressive medications and weight gain, whatever was the initial liver disease leading to the indication of LT. Therefore, the role of bariatric surgery (BS) is important due to its longer-lasting effect and efficacy. We performed a retrospective review of all 50 adult French liver transplant recipients who had a history of bariatric surgery, including 37 procedures before transplantation, and 14 after. There were three significantly different characteristics when comparing pre-and post-LT BS: patients were older (at the time of BS), presented more frequently arterial hypertension (at the time of LT), and the proportion of NAFLD as initial liver disease leading to LT was lower, in the post-LT group. Regarding pre-LT BS, in one case BS was complicated by liver failure leading to the rapid indication of LT; it was the single patient for whom the delay between BS and LT was less than 1 year; there was no patient who specifically underwent BS for the purpose of LT listing.

The Impact of Bariatric-Surgery-Induced Weight Loss on Patients Undergoing Liver Transplant: A Focus on Metabolism, Pathophysiological Changes, and Outcome in Obese Patients Suffering NAFLD-Related Cirrhosis

Because of their condition, patients with morbid obesity develop several histopathological changes in the liver, such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), cirrhosis, and end-stage liver disease (ESLD). Hence, a liver transplant (LT) becomes an opportune solution for them. Due to many challenges during the perioperative and postoperative periods, these patients are recommended to lose weight before the surgery. There are many proposals to achieve this goal, such as intragastric balloons and many different bariatric surgery (BS) procedures in combination with a preparation diet (very-low-calorie diet, ketogenic diet, etc.). All the interventions focus on losing weight and keeping the continuity and functionality of the digestive tract to avoid postoperative complications. Thus, this review analyzes recent publications regarding the metabolic and pathophysiological impacts of BS in LT patients suffering from NAFLD-related cirrhosis, the effect of weight loss on postoperative complications, and exposes the cost-effectiveness of performing BS before, after, and at liver transplantation. Finally, the authors recommend BS before the LT since there are many positive effects and better outcomes for patients who lose weight before the procedure. Nevertheless, further multicentric studies are needed to determine the generalizability of these recommendations due to their impact on public health.

Bariatric surgery, obesity and liver transplantation

The obesity epidemic has profoundly impacted the epidemiology and trends of liver disease. In the current era, non-alcoholic fatty liver disease (NAFLD) progressing to non-alcoholic steatohepatitis (NASH) has emerged as the second leading indication for liver transplant (LT) and has been associated with the rising rates of hepatocellular carcinoma (HCC) with and without underlying cirrhosis. Obesity has been associated with poor post-transplant outcomes including lower patient and graft survival; higher risk of post-operative metabolic complications; poor wound healing; and higher infection rates. Bariatric surgery is currently the most effective management of morbid obesity and has been offered to patients both in the pre and post LT setting. The techniques attempted in LT recipients most commonly include sleeve gastrectomy (SG), gastric bypass surgery with few cases of gastric banding and biliopancreatic diversion. However, there is lack of evidence-based data on the optimal management for patients with obesity and who are liver transplant candidates and/or recipients. In the following discussion, we present the highlights from a review of the literature.

Liver Injury and Acute Liver Failure After Bariatric Surgery: An Overview of Potential Injury Mechanisms

The obesity epidemic has caused a surge in the use of bariatric surgery. Although surgery-induced weight loss is an effective treatment of nonalcoholic fatty liver disease, it may precipitate severe hepatic complications under certain circumstances. Acute liver injury (ALI) and acute liver failure (ALF) following bariatric surgery have been reported in several case series. Although rare, ALI and ALF tend to emerge several months after bariatric surgery. If so, it can result in prolonged hospitalization, may necessitate liver transplantation, and in some cases prove fatal. However, little is known about the risk factors for developing ALI or ALF after bariatric surgery and the mechanisms of liver damage in this context are poorly defined. This review provides an account of the available data on ALI and ALF caused by bariatric surgery, with emphasis on potential injury mechanisms and the outcomes of liver transplantation for ALF after bariatric surgery.

Liver Decompensation after Bariatric Surgery in the Absence of Cirrhosis

PURPOSE

Metabolic dysfunction-associated fatty liver disease-related cirrhosis is possible at the time of bariatric surgery, complicated by further liver decompensation. Hepatic decompensation can also occur in the absence of cirrhosis but the presentation is less clear.

METHODS

We analyze the clinical characteristics, histological findings, and management of patients without cirrhosis who developed hepatic decompensation after bariatric surgery in our single tertiary-care hospital.

RESULTS

From 2014 to 2019, 6 patients underwent a transvenous liver biopsy for liver decompensation after bariatric surgery. Mean age at diagnosis was 44 years. The time between bariatric surgery and the onset of symptoms varied widely (min. 8 months, max. 17 years). Mean % of weight loss was high at 43%. The clinical presentation was as follows: fatigue and jaundice (5/6), leg edema (3/6), and ascites (1/6). Blood test showed increased transaminases (mean ALT 53 UI/L, mean AST 130 UI/L), bilirubin (mean 6 mg/dL), and INR (mean 1.5) with a low albumin level (mean 27 mg/dL). The hepatic venous pressure gradient was high (mean 10 mmHg). Histology revealed steatosis, hepatocyte ballooning but also portal inflammation with polymorphonuclear cells, and bile duct alterations. Mean fibrosis score was 2. The clinical course was favorable with nutritional support with a mean follow-up of 36 months.

CONCLUSION

Liver decompensation in the absence of cirrhosis can occur after bariatric surgery with a highly variable delay. A special histological signature is present with the coexistence of steatosis, bile duct alterations, and portal inflammation. Substantial clinical improvement with appropriate nutritional support seems to be effective.

Weight loss interventions and nonalcoholic fatty liver disease: Optimizing liver outcomes

The growth in prevalence of obesity, type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has become one of the most important global health challenges. The three chronic diseases are closely linked in their epidemiology and pathophysiology. Currently, weight loss is the most effective treatment for NAFLD (even in the minority of patients with NAFLD who do not have obesity) and is recommended in all national and international guidelines. Accumulating evidence has shown that weight loss, whether achieved by diet and lifestyle interventions, bariatric surgery or pharmacotherapy, can improve biomarkers of NAFLD, as well as prevent progression and, in some cases, reverse fibrosis. There is a dose dependency of weight loss with NAFLD improvement. Pharmacotherapy with antiobesity medications, alone or in combination with intensive lifestyle interventions or other weight-loss drugs, is closing the efficacy gap between diet and exercise and weight-loss surgery in efficacy at reversing obesity. Given the importance of providing effective weight-loss treatment to patients with NAFLD, weight management services need to be made increasingly available and embedded within hepatology services. This narrative review addresses the evidence that weight loss optimizes liver outcomes in people with NAFLD.

Risks and Rewards of Bariatric Surgery in Advanced Chronic Liver Diseases

The burden of obesity and metabolic syndrome has determined a sharp increase in bariatric surgery (BS) procedures, which lead to marked weight loss, improved metabolic syndrome, reduced cardiovascular risk, and even improvement in nonalcoholic steatohepatitis (NASH). Despite these promising results, BS in patients with chronic liver disease can rarely lead to worsening of liver function, progression to cirrhosis and its complications, and even liver transplantation. On the other hand, since obesity in patients with cirrhosis is a major cofactor for progression to a decompensated stage of the disease and a risk factor for hepatocellular carcinoma, BS has been used to achieve weight loss in this population. In this review, we critically analyze the existing data on outcomes of BS in patients with cirrhosis and the possible mechanisms leading to fibrosis progression and worsening liver function in patients undergoing BS. Finally, we propose a set of measures that could be taken to improve the multidisciplinary management of liver disease in patients undergoing BS, including early recognition of malnutrition and alcohol misuse.

Clinical and Economic Impact of Previous Bariatric Surgery on Liver Transplantation: a Nationwide, Population-Based Retrospective Study

Purpose

The present study aims to determine the impact of previous bariatric surgery (BS) on the length of hospital stay; the incidence of mortality, re-transplantation, and re-hospitalization after LT; and the related economic costs, through the analysis of the French National Health Insurance Information System.

Materials and Methods

All patients aged > 18 years who underwent LT in France in the period from 2010 to 2019 were included. Thirty-nine patients with a history of BS (study group) were compared with 1798 obese patients without previous BS (control group).

Results

At the time of LT, patients with a history of BS were significantly younger than those of the control group and had lower Charlson comorbidity index. Female sex was significantly more represented in the study group. No significant differences were detected between the two groups regarding the postoperative mortality rate after LT (10.3% in the study group versus 8.0% in the control group), long-term mortality (0.038 versus 0.029 person-year of follow-up, respectively), re-transplantation (adjusted hazard ratio (HR) = 2.15, p = 0.2437), re-hospitalization (adjusted analysis, IRR = 0.93, p = 0.7517), and costs of LT hospitalization (73,515 € in the study group versus 65,878 € in the control group). After 1:2 propensity score matching, the duration of the LT hospital stay was significantly longer in the study group (58.3 versus 33.4 days, p = 0.0172).

Conclusion

No significant differences were detected between patients with previous BS versus obese patients without history of BS undergoing LT concerning the rates of mortality, re-LT, re-hospitalization after LT, and costs of hospitalization and re-hospitalizations.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05684-4.

Bariatric surgery and the liver-Mechanisms, benefits, and risks

The prevalence of obesity and metabolic diseases such as type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) has risen dramatically over the past decades. At present, bariatric surgery is the most effective treatment for this global health problem, through effects on food intake, gut hormone secretion, metabolic signaling pathways, and adipose tissue dysfunction. The liver occupies a central role in carbohydrate, protein, and lipid metabolism. Notably, a reduction in hepatic fat content and an improvement in hepatic insulin resistance are among the earliest beneficial effects of bariatric surgery, which has therefore emerged as an attractive treatment option for NAFLD. However, as the scope and popularity of weight loss surgery have expanded, new questions have arisen regarding its safety in patients with liver cirrhosis, the outcome of liver transplantation in patients with a history of bariatric surgery, and over incidental reports of liver failure following surgery. Studies in humans and rodents have also linked bariatric surgery to an increased risk of developing alcohol use disorder, a major risk factor for liver disease. This review integrates data from clinical and translational research to delineate both the beneficial impact of bariatric surgery on the liver and the potential risks involved.

Clinical Impact of Antecedent Bariatric Surgery on Liver Transplant Outcomes: A Retrospective Matched Case-control Study

BACKGROUND

Bariatric surgery (BS) may be associated with significant malabsorption and nutritional deficiencies.

METHODS

Between March 1987 and January 2017, we performed 922 liver transplants (LT) at our institution; 33 had antecedent BS. We matched the BS cohort to LT recipients without BS (1:3 matching) based on exact matching for gender and cancer and inverse variance matching for age, LT body mass index, MELD score, and transplant date.

RESULTS

We analyzed outcomes in 132 LT recipients (33 BS; 99 non-BS). The BS cohort comprised 26 (79%) women with a mean age of 52.4 years. The BS procedures included 20 Roux-en-Y gastric bypass (61%), 6 jejunoileal bypass (18%), 3 gastric band (9%), 2 sleeve gastrectomy (6%), and 1 duodenal switch (3%). The primary indications for LT listing were alcoholic cirrhosis (9; 27%), nonalcoholic steatohepatitis (7; 21%), hepatitis C (8; 24%), and hepatocellular carcinoma (3; 9%). At LT, body mass index for the BS cohort was 29.6, and MELD was 24. Compared with matched controls, BS recipients did not have longer LT length of hospital stay (17.8 versus 15.7 d, P = 0.71), longer intensive care unit length of stay (5.3 versus 4.1 d, P = 0.16), or higher 30-day complication rate (76% versus 85%, P = 0.43). Overall patient survival was similar (1- and 3-y survival was 90.1% and 75.9% for BS; 90.9% and 76.4% for non-BS, P = 0.34).

CONCLUSIONS

A history of BS does not portend a deleterious effect on LT outcomes.

Liver transplantation for rare liver diseases and rare indications for liver transplant

Liver transplantation (LT) is currently considered the gold standard treatment for end-stage liver failure. Compared to the first decades of its use, LT is associated with lower comorbidity and mortality, with a 5-year survival over 70%. Worldwide, liver cirrhosis and hepatocellular carcinoma represent the major indications to LT. However, almost 1% of LT is performed for rare diseases or rare indications, which include non-hepatocellular malignancy, vascular disorders, metabolic and congenital liver disorders. These diseases can lead to hepatocellular necrosis, biliary tree abnormality and/or hepatomegaly. Most of these diseases are not associated with liver failure but in highly selected patients, LT represent an effective therapy improving the overall survival and quality of life. Rare indications for LT often overlap with rare diseases. However, rare LT indications for non-rare diseases are rising in the last decades, especially for benign primary liver tumor, colon rectal liver metastasis, neuroendocrine liver metastasis, and cholangiocarcinoma (CCA). Non-rare diseases with rare indication for LT and rare adult disease with an indication for LT are categorized and discussed in detail, focusing on some disorders for which the literature provides a more definitive evidence base. Early referral to a transplant center is encouraged to provide an effective therapeutic option in these non-standard indications for LT.

Acute Liver Failure following Sleeve Gastrectomy with Jejuno-Ileal Bypass

INTRODUCTION

Laparoscopic sleeve gastrectomy (LSG) is one of the most commonly performed bariatric surgery in recent years, and some modifications have emerged to improve its efficacy. Melissas has described SG plus jejuno-ileal bypass (JIB), which has reported good results in a few studies. We performed this procedure in 21 cases and in one case, we observed acute liver failure (ALF) that has not been reported before.

CASE PRESENTATION

A 38-year-old female (BMI: 56.1 kg/m²) underwent laparoscopic SG plus JIB. There was no sign of diarrhea, malnutrition or liver failure for eight months and her BMI was 43.0 kg/m². At the 9th month, she was hospitalized for abdominal pain, jaundice and ALF. The patient was treated by plasmapheresis and molecular absorptive recirculation system. She was planned to undergo liver transplantation but died of multiorgan failure on the 40th day of hospitalization.

CONCLUSION

ALF can be observed following SG plus JIB. JIB reversal before compromising liver functions should be taken into consideration.

Obesity Management of Liver Transplant Waitlist Candidates and Recipients

Obesity is increasing in prevalence in liver transplant candidates and recipients. The rise in liver transplantation for nonalcoholic steatohepatitis reflects this increase. Management of obesity in liver transplant candidates can be challenging due to the presence of decompensated cirrhosis and sarcopenia. Obesity may increase peritransplant morbidity but does not have an impact on long-term post-transplant survival. Bariatric surgery may be a feasible option in select patients before, during, or after liver transplantation. Use of weight loss drugs and/or endoscopic therapies for obesity management ultimately may play a role in liver transplant patients, but more research is needed to determine safety.

The IFSO Worldwide One Anastomosis Gastric Bypass Survey: Techniques and Outcomes?

INTRODUCTION

One anastomosis gastric bypass (OAGB) has become one of the most commonly performed gastric bypass procedures in some countries.

OBJECTIVES

To assess how surgeons viewed the OAGB, perceptions, indications, techniques, and outcomes, as well as the incidence of short- and long-term complications and how they were managed worldwide.

METHODS

A questionnaire was sent to all IFSO members in all 5 chapters to study the pattern of practice and outcomes of OAGB.

RESULTS

Seven hundred and forty-two surgeons responded. The most commonly performed procedures were sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and OAGB. Preoperatively, 70% of the surgeons performed endoscopy routinely. In regards to weight loss, 83% (570 surgeons) responded that OAGB produces better weight loss than SG, and 49% (342 surgeons) responded that OAGB produces better weight loss than RYGB. The most common length of the biliopancreatic limb (BPL) utilized was 200 cm. Sixty-seven percent of surgeons did not measure the total length of the small bowel. In patients with reflux disease and history of smoking, 53% and 22% of surgeons respectively still offered OAGB as a treatment option. Postoperatively, leak was documented in 963 patients, and it was the leading cause for mortality. Leak management was conservative in 35%. Conversion to RYGB was performed in 31%. In 16% the anastomosis was reinforced, 6% of the patients were reversed, and other procedures were performed in 12%. Revision of OAGB for malnutrition/steatorrhea or severe bile reflux was reported at least once by 37% and 45% of surgeons, respectively (200 cm was the most commonly encountered biliopancreatic limb BPL in those revised for malnutrition). Most common strategy for revision was conversion to RYGB (43%), reversal to normal anatomy (32%), shortening of the BPL (20%), and conversion to SG (5%). Nevertheless, 5 out of 98 mortalities (5%) were due to liver failure/malnutrition.

CONCLUSION

There are infrequent but potentially severe specific complications including malnutrition, liver failure, and bile reflux that may require surgical correction after OAGB.

The Hardship of Recovering a Patient from Liver Failure after One Anastomosis Gastric Bypass

BACKGROUND

The one anastomosis gastric bypass (OAGB) was first described in 2001 as a safe and effective procedure that meets the criteria for the "ideal" weight loss operation. However, revisions for malnutrition and liver failure were reported.

CASE REPORT

We report a patient who was transferred to our institution with protein calorie malnutrition and liver failure after undergoing OAGB.

METHODS

A 42-year-old morbidly obese female patient underwent a laparoscopic sleeve gastrectomy (LSG) in 2012 followed by conversion to OAGB in 2018 for weight regain at another institution. Nine months after conversion, she was transferred to our institution with dehydration, vomiting, dysphagia, generalized edema, and steatorrhea (7 times/day). She had become wheelchair bound. On examination, there was gross edema, protein-calorie malnutrition, dermatitis, and muscle wasting. She had anemia (8 g/dl) reference range (11.5-15.5 g/dl), bilirubin (1.8 mg/dl) (0.2-1.2 mg/dl), hypoalbuminemia (1.4 g/dl) (3.5-5 g/dl), and elevated international normalized ratio (INR). The patient was admitted to the hospital and was started on total parenteral nutrition (TPN), with thiamine, vitamins, iron injections, and trace mineral replacement. Her course was complicated by multiple episodes of line sepsis and bacteremia. After 6 weeks, we succeeded in raising her albumin to 2.9 g/dl and proceeded with surgery.

TECHNIQUE

Laparoscopic exploration started with identifying the anatomy and measuring the biliopancreatic limb (BPL = 430 cm) and the common channel (CC = 380 cm). First, we restored the continuity of the small bowel. Then the long gastric pouch was trimmed. Finally, the patient was converted to a Roux-en-Y gastric bypass (RYGB) with a 30 cm BP limb and 70 cm Roux limb. The patient had an uneventful recovery and was discharged home on the fourth postoperative day. At 3 months of follow-up, her symptoms resolved, her laboratory work up normalized, and she regained mobility.

CONCLUSION

Malnutrition and liver failure after OAGB are not uncommon. It is encountered with configurations of longer BP limb. BPL length of 150 to 200 cm seems to reduce such complications. Preoperative nutritional optimization is key. Conversion to a proximal RYGB is a safe and feasible approach.

Histological grading evaluation of non-alcoholic fatty liver disease after bariatric surgery: a retrospective and longitudinal observational cohort study

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease with several degrees of histological features which may progress to cirrhosis. Obesity is an important risk factor and although NAFLD has no specific pharmacological treatment, bariatric surgery has been associated with NAFLD regression in severely obese patients. However, few longitudinal histological studies support this finding. Therefore, firstly, a retrospective study was performed including clinical and histological data of 895 obese patients who underwent bariatric surgery. In addition, histological analyses of 30 patient’s liver biopsies were evaluated at two timepoints (T1 and T2). The retrospective analysis of the total number of patients revealed that the average body mass index (BMI) was 35.91 ± 2.81 kg/m². The liver biopsies during bariatric surgery showed that 53.52% did not present NAFLD, 30.16% had NASH, 15.98% isolated steatosis and 0.34% liver cirrhosis. The median BMI of the longitudinal cohort decreased from 37.9 ± 2.21 kg/m² at the time of bariatric surgery (T1) to 25.69 ± 3.79 kg/m² after 21 ± 22 months after the procedure (T2). The prevalence of NAFLD in T1 was 50%, and 16.67% in T2. The histological area of collagen fiber was lower in T2 compared to T1 (p = 0.0152) in the majority of patients, which was also illustrated by immunohistochemistry for Kupffer cell and myofibroblast formation markers. These findings confirmed the NAFLD regression after bariatric surgery and, for the first time, showed the amelioration of these features using more accurate histopathological techniques.

Obesity in the Liver Transplant Setting

The obesity epidemic has resulted in an increased prevalence of obesity in liver transplant (LT) candidates and in non-alcoholic fatty liver disease (NAFLD) becoming the fastest growing indication for LT. LT teams will be dealing with obesity in the coming years, and it is necessary for them to recognize some key aspects surrounding the LT in obese patients. Obesity by itself should not be considered a contraindication for LT, but it should make LT teams pay special attention to cardiovascular risk assessment, in order to properly select candidates for LT. Obese patients may be at increased risk of perioperative respiratory and infectious complications, and it is necessary to establish preventive strategies. Data on patient and graft survival after LT are controversial and scarce, especially for long-term outcomes, but morbid obesity may adversely affect these outcomes, particularly in NAFLD. The backbone of obesity treatment should be diet and exercise, whilst being careful not to precipitate or worsen frailty and sarcopenia. Bariatric surgery is an alternative for treatment of obesity, and the ideal timing regarding LT is still unknown. Sleeve gastrectomy is probably the procedure that has the best evidence in LT because it offers a good balance between safety and efficacy.