Numerical Modeling of the Effects of Channel Configurations and Inclination Angles Inducing Buoyancy on Reverse Osmosis

This numerical study presents a comparison between two different reverse osmosis channel configurations. The physical properties were considered in the computational model as a function of the solute mass fraction. A critical comparison was performed between double-sided membrane channel and single-sided one considering the concentration and flow distribution. Gravitational effect was implemented by introducing the inclination of double membrane geometry for the first time in the literature of reverse osmosis systems. FORTRAN in-house code was developed to resolve conservation equations (mass, momentum, and solute mass fraction) based on the finite volume method. The results of the simulation show that the water recovery factor of double-membrane arrangement is two times higher than the single membrane arrangement. Concentration polarization (CP) can be reduced by both increasing the feed Reynolds number (Re) and decreasing the Aspect Ratio (AR). Considering the cases of low flow rates (up to Re = 40) with the flow orientation in the direction of gravity inducing buoyancy effects. The influence of the inclination showed that the average permeate flux, and the water recovery are proportional to the inclination angle up to the maximum values at the right angle (vertical plane)

Bleeding Recurrence and Mortality Following Interventional Management of Spontaneous HCC Rupture: Results of a Multicenter European Study

International audienceBACKGROUND: The incidence of spontaneous rupture of hepatocellular carcinoma (HCC) is low in Europe, at less than 3%. HCC rupture remains a life-threatening complication, with mortality reported between 16 and 30%. The risk of bleeding recurrence has never been clearly evaluated in such clinical situation. The objectives of this study were to evaluate the current risk of mortality related to HCC rupture and to focus on the risk of bleeding recurrence following interventional management. METHODS: All patients admitted to 14 French-Italian surgical centers for spontaneous rupture of HCC between May 2000 and May 2012 were retrospectively included. Clinical data, imaging features, relevant laboratory data, treatment strategies, and prognoses were analyzed. RESULTS: Overall, 58 of the 138 included patients (42%) had cirrhosis. Thirty-five patients (25%) presented with hemorrhagic shock, and 19% with organ(s) dysfunction. Bleeding control was obtained by interventional hemostasis, emergency liver resection, and conservative medical management in 86 (62%), 24 (18%), and 21 (15%) patients, respectively. Best supportive care was chosen for 7 (5%) patients. The mortality rate following rupture was 24%. The bleeding recurrence rate was 22% with related mortality of 52%. In multivariate analysis, a bilirubin level \textgreater17 micromol/L (HR 3.768; p~=~0.006), bleeding recurrence (HR 5.400; p~\textless~0.0001), and ICU admission after initial management (HR 8.199; p~\textless~0.0001) were associated with in-hospital mortality. CONCLUSION: This European, multicenter, large-cohort study confirmed that the prognosis of ruptured HCC is poor with an overall mortality rate of 24%, despite important advances in endovascular techniques. Overall, the rate of bleeding recurrence was more than 20%, with a related high risk of mortality

Impact of cirrhosis in patients undergoing laparoscopic liver resection in a nationwide multicentre survey

BACKGROUND: The aim was to analyse the impact of cirrhosis on short-term outcomes after laparoscopic liver resection (LLR) in a multicentre national cohort study. METHODS: This retrospective study included all patients undergoing LLR in 27 centres between 2000 and 2017. Cirrhosis was defined as F4 fibrosis on pathological examination. Short-term outcomes of patients with and without liver cirrhosis were compared after propensity score matching by centre volume, demographic and tumour characteristics, and extent of resection. RESULTS: Among 3150 patients included, LLR was performed in 774 patients with (24·6 per cent) and 2376 (75·4 per cent) without cirrhosis. Severe complication and mortality rates in patients with cirrhosis were 10·6 and 2·6 per cent respectively. Posthepatectomy liver failure (PHLF) developed in 3·6 per cent of patients with cirrhosis and was the major cause of death (11 of 20 patients). After matching, patients with cirrhosis tended to have higher rates of severe complications (odds ratio (OR) 1·74, 95 per cent c.i. 0·92 to 3·41; P = 0·096) and PHLF (OR 7·13, 0·91 to 323·10; P = 0·068) than those without cirrhosis. They also had a higher risk of death (OR 5·13, 1·08 to 48·61; P = 0·039). Rates of cardiorespiratory complications (P = 0·338), bile leakage (P = 0·286) and reoperation (P = 0·352) were similar in the two groups. Patients with cirrhosis had a longer hospital stay than those without (11 versus 8 days; P = 0·018). Centre expertise was an independent protective factor against PHLF in patients with cirrhosis (OR 0·33, 0·14 to 0·76; P = 0·010). CONCLUSION: Underlying cirrhosis remains an independent risk factor for impaired outcomes in patients undergoing LLR, even in expert centres

Benchmark performance of laparoscopic left lateral sectionectomy and right hepatectomy in expert centers

International audienceHerein, we aimed to establish benchmark values - based on a composite indicator of healthcare quality - for the performance of laparoscopic left lateral sectionectomy (LLLS) and laparoscopic right hepatectomy (LRH) using data from expert centers

Benchmark performance of laparoscopic left lateral sectionectomy and right hepatectomy in expert centers

Background & Aims: Herein, we aimed to establish benchmark values – based on a composite indicator of healthcare quality – for the performance of laparoscopic left lateral sectionectomy (LLLS) and laparoscopic right hepatectomy (LRH) using data from expert centers. Methods: Data from a nationwide multicenter survey including all patients undergoing LLLS and LRH between 2000 and 2017 were analyzed. Textbook outcome (TO) completion was considered in patients fulfilling all 6 of the following characteristics: negative margins, no transfusion, no complication, no prolonged hospital stay, no readmission and no mortality. For each procedure, a cut-off laparoscopic liver resection (LLR) volume by center was associated with TO on multivariable analysis. These cut-offs defined the expert centers. The benchmark values were set at the 75th percentile of median outcomes among these expert centers. Results: Among 4,400 LLRs performed in 29 centers, 855 patients who underwent LLLS and 488 who underwent LRH were identified. The overall incidences of TO after LLLS and LRH were 43.7% and 23.8%, respectively. LLR volume cut-offs of 25 LLR/year (odds ratio [OR] 2.45; bootstrap 95% CI 1.65–3.69; p = 0.001) and 35 LLR/year (OR 2.55; bootstrap 95% CI 1.34–5.63; p = 0.003) were independently associated with completion of TO after LLLS and LRH, respectively. Eight centers for LLLS and 6 centers for LRH, including 516 and 346 patients undergoing LLLS/LRH respectively, reached these cut-offs and were identified as expert centers. After LLLS, benchmark values of severe complication, mortality and TO completion were defined as ≤5.3%, ≤1.2% and ≥46.6%, respectively. After LRH, benchmark values of severe complication, mortality and TO completion were ≤20.4%, ≤2.8% and ≥24.2%, respectively. Conclusions: This study provides an up-to-date reference on the benchmark performance of LLLS and LRH in expert centers. Lay summary: In a nationwide French survey of laparoscopic liver resection, expert centers were defined according to the completion of a textbook outcome, which is a composite indicator of healthcare quality. Benchmark values regarding intra-operative details and outcomes were established using data from 516 patients with laparoscopic left lateral sectionectiomy and 346 patients with laparoscopic right hepatectomy from expert centers. These values should be used as a reference point to improve the quality of laparoscopic resections