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.

Stapling Through a Bougie During Sleeve Gastrectomy in a Superobese Patient-a Video Vignette

Purpose

Bariatric-metabolic surgery in superobese patients (BMI > 50 kg/m²) is very challenging indeed with little room for error. In many cases, a two-step procedure is required, since more complex primary bariatric procedures can be technically demanding and bearing a relevant risk for the patient. At our institution, laparoscopic sleeve gastrectomy (SG) is the preferred primary procedure, followed by a conversion to either SADI-S or Roux-en-Y gastric bypass (RYGB) after initial weight loss is achieved [1, 2]. This video aims at demonstrating the conversion from primary SG to RYGB due to an adverse event in a 45-year-old superobese female patient (weight, 170 kg; BMI, 73 kg/m²).

Methods

An intraoperative laparoscopic video has been anonymized and edited to demonstrate the course of the operation on the patient mentioned above.

Results

The start of the procedure was uneventful. After a successful mobilization of the greater curvature, the stomach was resected with an electronic stapling device guided by a firm 36-french bougie (Rüsch, Germany) towards the angle of His. Due to a limited view, a stapler was placed over the bougie, which resulted in the stomach being subtotally transected, the staples attaching the bougie to the sleeve about 5 cm from the gastroesophageal junction. Salvage surgery after removing the remnants of the bougie was a conversion to RYGB.

Conclusion

When performing a bariatric-metabolic surgery in superobese patients, an extended skill level is required to provide a solution, should anything go wrong. Therefore, we suggest bariatric-metabolic surgery in superobese patients to be performed solely and specifically at high-volume centres.

Electronic supplementary material

The online version of this article (10.1007/s11695-020-04790-z) contains supplementary material, which is available to authorized users.

Hard Block Degradable Polycarbonate Urethanes: Promising Biomaterials for Electrospun Vascular Prostheses

We report biodegradable thermoplastic polyurethanes for soft tissue engineering applications, where frequently used carboxylic acid ester degradation motifs were substituted with carbonate moieties to achieve superior degradation properties. While the use of carbonates in soft blocks has been reported, their use in hard blocks of thermoplastic polyurethanes is unprecedented. Soft blocks consist of poly(hexamethylene carbonate), and hard blocks combine hexamethylene diisocyanate with the newly synthesized cleavable carbonate chain extender bis(3-hydroxypropylene)carbonate (BHPC), mimicking the motif of poly(trimethylene carbonate) with highly regarded degradation properties. Simultaneously, the mechanical benefits of segmented polyurethanes are exploited. A lower hard block concentration in BHPC-based polymers was more suitable for vascular grafts. Nonacidic degradation products and hard block dependent degradation rates were found. Implantation of BHPC-based electrospun degradable vascular prostheses in a small animal model revealed high patency rates and no signs of aneurysm formations. Specific vascular graft remodeling and only minimal signs of inflammatory reactions were observed.

Long Term Evaluation of Nanofibrous, Bioabsorbable Polycarbonate Urethane Grafts for Small Diameter Vessel Replacement in Rodents

OBJECTIVE

Biodegradable materials for in situ vascular tissue engineering could meet the increasing clinical demand for sufficient synthetic small diameter vascular substitutes in aortocoronary bypass and peripheral vascular surgery. The aim of this study was to design a new degradable thermoplastic polycarbonate urethane (dPCU) with improved biocompatibility and optimal biomechanical properties. Electrospun conduits made from dPCU were evaluated in short and long term follow up and compared with expanded polytetrafluoroethylene (ePTFE) controls.

METHODS

Both conduits were investigated prior to implantation to assess their biocompatibility and inflammatory potential via real time polymerase chain reaction using a macrophage culture. dPCU grafts (n = 28) and ePTFE controls (n = 28) were then implanted into the infrarenal abdominal aorta of Sprague-Dawley rats. After seven days, one, six, and 12 months, grafts were analysed by histology and immunohistochemistry (IHC) and assessed biomechanically.

RESULTS

Anti-inflammatory signalling was upregulated in dPCU conduits and increased significantly over time in vitro. dPCU and ePTFE grafts offered excellent long and short term patency rates (92.9% in both groups at 12 months) in the rat model without dilatation or aneurysm formation. In comparison to ePTFE, dPCU grafts showed transmural ingrowth of vascular specific cells resulting in a structured neovessel formation around the graft. The graft material was slowly reduced, while the compliance of the neovessel increased over time.

CONCLUSION

The newly designed dPCU grafts have the potential to be safely applied for in situ vascular tissue engineering applications. The degradable substitutes showed good in vivo performance and revealed desirable characteristics such as biomechanical stability, non-thrombogenicity, and minimal inflammatory response after long term implantation.

Update: 10 Years of Sleeve Gastrectomy-the First 103 Patients

BACKGROUND

Sleeve gastrectomy (SG) has been the most frequently performed bariatric procedure worldwide since 2014. Therefore, it is vital to look at its outcomes in a long-term follow-up based on a large patient collective. Main points of discussion are weight regain, reflux, and patients' quality of life at 10+ years after the procedure.

OBJECTIVES

The aim of this study is to present an update of data that have been published recently and, thus, achieve more conclusive results. The number of patients has been doubled, and the length of the follow-up is still 10+ years.

SETTING

Multi-center study, medical university clinic, Austria METHODS: This study includes all patients who had SG before December 2006 at the participating bariatric centers. At 10+ years, non-converted patients (67%) were examined using gastroscopy, manometry, 24-hour pH-metry, and questionnaires. Patients' history of weight, comorbidities, and reflux were established through interviews.

RESULTS

At 10+ years after SG, the authors found a conversion rate of 33%, an %EWL in non-converted patients of 50.0 ± 22.5, reflux in 57%, and Barrett's metaplasia in 14% of non-converted patients. Gastroscopies revealed that patients with reflux were significantly more likely to have de-novo hiatal hernia. A significantly lower quality of life was detected through GIQLI and BAROS in patients with reflux.

CONCLUSION

The authors recommend gastroscopies at 5-year intervals after SG to detect the possible sequelae of reflux at an early stage. Conversion to Roux-en-Y-gastric bypass (RYGB) works well to cure patients from reflux but may not be as efficient at treating weight regain.

Evaluation and comparison of six noninvasive tests for prediction of significant or advanced fibrosis in nonalcoholic fatty liver disease

Background

In nonalcoholic fatty liver disease (NAFLD), advanced fibrosis has been identified as an important prognostic factor with increased liver-related mortality and treatment need. Due to the high prevalence of NAFLD, noninvasive risk stratification is needed to select patients for liver biopsy and treatment.

Objective

To compare the diagnostic accuracy of several widely available noninvasive tests for assessment of fibrosis among patients with NAFLD with or without nonalcoholic steatohepatitis (NASH).

Methods

We enrolled consecutive patients with NAFLD admitted to two Austrian referral centers who underwent liver biopsy. Liver stiffness measurement (LSM) was obtained by vibration-controlled transient elastography (VCTE, FibroScan) and blood samples were collected for determination of enhanced liver fibrosis (ELF) test, FibroMeter^V2G, FibroMeter^V3G, NAFLD fibrosis score (NFS), and fibrosis-4 index (FIB-4).

Results

Our study cohort contained 186 patients with histologically confirmed NAFLD. On liver histology, NASH was present in 92 patients (50%), significant fibrosis (F ≥ 2) in 71 patients (38%), advanced fibrosis (F ≥ 3) in 49 patients (26%), and F ≥ 3 plus NASH in 35 patients (19%). For diagnosis of F ≥ 2, F ≥ 3, and F ≥ 3 plus NASH, respectively, receiver operating characteristic (ROC) analysis revealed superior diagnostic accuracy of ELF score (area under ROC curve (AUROC) 0.85, 0.90, 0.90), FibroMeter^V2G (AUROC 0.86, 0.88, 0.89), FibroMeter^V3G (AUROC 0.84, 0.88, 0.88), and LSM per protocol (AUROC 0.87, 0.95, 0.91) versus FIB-4 (AUROC 0.80, 0.82, 0.81) or NFS (AUROC 0.78, 0.80, 0.79).

Conclusion

Proprietary fibrosis panels and VCTE show superior diagnostic accuracy for noninvasive diagnosis of fibrosis stage in NAFLD as compared to FIB-4 and NFS.

Quality of Life 10 Years after Sleeve Gastrectomy: A Multicenter Study

OBJECTIVE

Sleeve gastrectomy (SG) has recently become the most commonly applied bariatric procedure worldwide. Substantial regaining of weight or severe reflux might compromise quality of life (QOL) after SG in the long-term follow-up. Long-term data on patients' QOL is limited, even though the persistent improvement in QOL is one of the aims of bariatric surgery. The objective of this study was to present patients' QOL 10 years after SG.

METHODS

Of 65 SG patients with a follow-up of ≥10 years after SG who were asked to fill out the Bariatric Quality of Life Index (BQL) and Short Form 36 (SF36) questionnaires, 48 (74%) completed them. This multicenter study was performed in a university hospital setting in Austria.

RESULTS

The BQL score revealed nonsignificant differences between the patients with > 50% or < 50% excess weight loss (EWL). It did show significant differences between patients with and without any symptoms of reflux. Patients with < 50% EWL scored significantly lower in 3/8 categories of SF36. Patients suffering from reflux had significantly lower scores in all categories.

CONCLUSIONS

EWL and symptomatic reflux impair patients' long-term QOL after SG.

Significant Liver-Related Morbidity After Bariatric Surgery and Its Reversal-a Case Series

Background

Nonalcoholic fatty liver disease (NAFLD) occurs in up to 80% of patients with obesity. Current data suggest an improvement of NAFLD after established bariatric procedures.

Objectives

This study investigated liver function impairment after Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB).

Setting

University Hospital, Bariatric Surgery Unit

Methods

In this single-center case series, consecutive in- and outpatients after bariatric surgery who presented with severe liver dysfunction from March 2014 to February 2017 were included and followed until March 2017.

Results

In total, 10 patients (m:f = 2:8; median age 48 years, range 22–66 years) were included. Liver dysfunction occurred after a median postoperative time of 15 months (range 2–88 months). Median %excess weight loss at that time was 110.6% (range 85.2–155.5%). Liver steatosis/fibrosis occurred in 70%, cirrhosis in 30% of patients, and led to fatigue (90%), ascites (70%), hepatic encephalopathy (30%), and upper gastrointestinal bleeding (20%). Elevation of transaminases, impairment of coagulation parameters, thrombocytopenia, and hypoalbuminemia were present in 70, 80, 70, and 100%, respectively. In eight patients, lengthening of the alimentary/common limb led to an improvement or complete remission of symptoms. In one patient, liver transplantation was required, one patient deceased due to septic shock and decompensated liver disease.

Conclusions

Severe liver dysfunction may also occur after bariatric procedures such as OAGB and RYGB. A comprehensive, meticulous follow-up for early identification of postoperative liver impairment should be aspired. Bypass length reduction led to a fast improvement in all patients.

Preserved right ventricular integrity in a new telemetric rat model of severe pulmonary hypertension

Telemetric monitoring of hemodynamic parameters has become an established standard in experimental models of pulmonary arterial hypertension (PAH). To that purpose, a dedicated catheter is usually implanted through the right ventricular wall of study animals. Drawbacks of this standard technique are as follows: obtained pressures are from the right ventricle and therefore only surrogates for pulmonary arterial pressures, and furthermore, right ventricular myocardium is always damaged to a certain degree. To overcome shortcomings of standard hemodynamic assessment, we modified an established rat model, where severe PAH is induced by left-sided pneumonectomy plus monocrotaline injection. We describe here a novel telemetry catheter implantation technique, where the device is advanced into the pulmonary artery via the remaining stump and the transmitter is placed in a subcutaneous pocket. A total of 105 rats were operated with a median (range) implantation time of 50 (30-88) min and an excellent perioperative survival of 93%. After monocrotaline induction on day 7, animals developed severe PAH with mean ± SD pressures of 75.9 ± 18.6 (systolic), 55.0 ± 18.0 (mean), and 42.1 ± 21.3 mmHg (diastolic) after 4 wk. Postmortem, the animals showed severe right ventricular hypertrophy, and histological analysis confirmed excessive medial hypertrophy and intimal hyperplasia, both characteristic features of human PAH. Comparison of the new telemetric model with standard microtip catheterization did not show relevant measurement differences. We established the first experimental animal model for PAH with preserved right ventricular integrity that allows direct telemetric monitoring of real-time systolic, mean, and diastolic pressures in the main pulmonary artery of freely moving rats.

Mass spectrometric imaging of in vivo protein and lipid adsorption on biodegradable vascular replacement systems

Cardiovascular diseases present amongst the highest mortality risks in Western civilization and are frequently caused by arteriosclerotic vessel failure. Coronary artery and peripheral vessel reconstruction necessitates the use of small diameter systems that are mechanically stress-resistant and biocompatible. Expanded polytetrafluorethylene (ePTFE) is amongst the materials used most frequently for non-degradable and bio-degradable vessel reconstruction procedures, with thermoplastic polyurethanes (TPU) representing a promising substitute. The present study describes and compares the biological adsorption and diffusion occurring with both materials following implantation in rat models. Gel electrophoresis and thin-layer chromatography, combined with mass spectrometry and mass spectrometry imaging, were utilized to identify the adsorbed lipids and proteins. The results were compared with the analytes present in native aorta tissue. It was revealed that both polymers were severely affected by biological adsorption after 10 min in vivo. Proteins associated with cell growth and migration were identified, especially on the luminal graft surface, while lipids were found to be located on both the luminal and abluminal surfaces. Lipid adsorption and cholesterol diffusion were found to be correlated with the polymer modifications identified on degradable thermoplastic urethane graft samples, with the latter revealing extensive cholesterol adsorption. The present study demonstrates an interaction between biological matter and both graft materials, and provides insights into polymer changes, in particular, those observed with thermoplastic urethanes already after 10 min in vivo exposure. ePTFE demonstrated minor polymer modifications, whereas several different polymer signals were observed for TPU, all were co-localized with biological signals.

Open trial of fluoxetine in children and adolescents with dysthymic disorder or double depression

BACKGROUND

Chronic depressions commonly present in youth and cause significant morbidity. No treatment studies in this age group are currently available.

METHODS

19 pediatric subjects with dysthymic disorder or 'double depression' were recruited. After four weeks of psychosocial treatment, subjects failing to improve began open treatment with fluoxetine (20 mg) for eight weeks. Subjects were then reassessed for treatment response.

RESULTS

Fifteen subjects entered the medication phase, and eleven (73%) no longer met criteria for dysthymic disorder or Major Depression at final assessment.

CONCLUSIONS

Fluoxetine shows promise as a safe and effective treatment for youth with chronic depressions. Controlled trials are indicated.

LIMITATIONS

Open label design, no comparison treatment condition.

CLINICAL RELEVANCE

As in adults, treatment with antidepressants may prove to be a useful intervention with children and adolescents with chronic forms of depression.