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INTRODUCTION Proton-pump inhibitors (PPI) are frequently prescribed for wide gastrointestinal disorders. The indications are well established, although a high rate of misuse has been reported. METHODS Observation cross-sectional study conducted a tertiary hospital. Adult patients who attended the emergency department were eligible. The appropriate indication was evaluated. Also, the prescription period, dosage and the prescribing clinician were reviewed. RESULTS 300 patients were included. The indication was adequate in 142 patients (47.3%). The main indication was the primary prophylaxis for NSAIDs/ASA-induced enteropathy (n=95 patients, 31.7%). Polypharmacy was the main misuse indication (n=82 patients, 27.3%). The median prescription duration was 31 months (IQR 9-72), ranging from one month to 360 months. The duration was lower in those with correct indication (42.3 vs 59.6 months, P=.02). The primary care physician was the main responsible for prescription (n=165 patients, 55%), followed by gastroenterologist (n=38 patients, 12.7%) without significant differences in appropriateness by speciality. CONCLUSIONS Studies like this raise awareness about the PPI overuse and misuse. Deprescribing should be considered as essential to reduce iatrogenic risk and redundant health expenditure.

Background and aims Transjugular intrahepatic portosystemic shunts (TIPS) are successfully used in the management of portal hypertension (PH)-related complications. Debate surrounds the diameter of the dilation. The aim was to analyse the outcomes of and complications deriving from TIPS in patients with cirrhosis and identify predictors of survival. Methods This was a retrospective single-centre study, which included patients with cirrhosis who had a TIPS procedure for PH from 2009 to October 2018. Demographic, clinical and radiological data were collected. The Kaplan–Meier method was used to measure survival and predictors of survival were identified with the Cox regression model. Results A total of 98 patients were included (78.6% male), mean age was 58.5 (SD±/−9.9) and the median MELD was 13.3 (IQR 9.5–16). The indications were refractory ascites (RA), variceal bleeding (VB) and hepatic hydrothorax (HH). Median survival was 72 months (RA 46.4, VB 68.5 and HH 64.7) and transplant-free survival was 26 months. Clinical and technical success rates were 70.5% and 92.9% respectively. Age (HR 1.05), clinical success (HR 0.33), sodium (HR 0.92), renal failure (HR 2.46) and albumin (HR 0.35) were predictors of survival. Hepatic encephalopathy occurred in 28.6% of patients and TIPS dysfunction occurred in 16.3%. Conclusions TIPS with 10-mm PTFE-covered stent is an effective and safe treatment for PH-related complications in patients with cirrhosis. Age, renal failure, sodium, albumin and clinical success are independent predictors of long-term survival.

EUS-guided choledochoduodenostomy (EUS-CDS) is an effective option for biliary drainage in malignant biliary obstruction. Lumen apposing metal stents (LAMS) are increasingly been used for EUS-CDS. It is unknown how LAMS compare to tubular self-expandable metal stents (SEMS) for EUS-CDS. Our aim is to compare the clinical outcomes of LAMS versus SEMS for EUS-CDS. Single-center retrospective cohort study of consecutive patients with unresectable malignant biliary obstruction who underwent EUS-CDS after failed ERCP for initial biliary drainage between 2011 and 2019. Clinical outcomes were compared between patients who had conventional covered SEMS and LAMS placed for EUS-CDS. Outcome measures included unplanned procedural events, technical success, clinical success, adverse events and reinterventions. Survival was analyzed by the Kaplan–Meier method. During the study period 57 patients met inclusion criteria (37 LAMS, 20 SEMS). All EUS-CDS were technically successful (LAMS group 95% CI 90.3–100%, SEMS group 95% CI 83.2–100%). There were no differences between groups in unplanned procedural events (4 LAMS deployment issues, 2 mild bleeding in SEMS group; 10 vs 10.8%), clinical success (37/37 [100%] vs 19/20 [95%]), and short-term adverse events (5/37 [13.5%] vs 4/20 [20%], p = 0.71). Complete follow-up data were available in 41 patients for a mean of 376 ± 145 days. Endoscopic reintervention was required for duodenal stent placement (n = 9) or biliary stent dysfunction (n = 4), with no difference between LAMS and SEMS group (6/37 [16.2%] vs 7/20 [35%]). There were no differences in overall survival between both groups. EUS-guided choledochoduodenostomy after failed ERCP has equally high technical and clinical success rates with either LAMS or SEMS in patients with malignant biliary obstruction. No differences in adverse events, reinterventions and survival were seen with either type of stent. The cost-effectiveness of LAMS vs SEMS for EUS-guided choledochoduodenostomy remains to be proven.

Background Immunosuppressive calcineurin inhibitors have been associated with an increased risk of post-transplant malignancies. The mammalian target of rapamycin inhibitors (mTORi) is an alternative immunosuppressive regimen with an antineoplastic effect. The aim of the study was to determine the long-term survival of mTORi-treated recipients with de novo or recurring tumors after liver transplantation (LT). Methods This retrospective analysis included mTORi-treated LT recipients between March 2013 and March 2019. We analyzed long-term survival and mTORi indications in an oncology setting in patients with de novo and recurrent malignancies after LT. Overall survival (OS) rate was compared from the Spanish Liver Transplant Registry (SLTR) data using the Kaplan-Meier method. High-risk hepatocellular carcinoma (HCC) was defined as microvascular invasion or satellite lesions as described in the liver explant. Results A total of 237 patients underwent LT during the study period; 111 patients underwent mTORi-based immunosuppression (48%, cancer was the main indication): 24.5% high-risk HCC; 24.4% HCC recurrence; 14.3% cholangiocarcinoma; and 36.7% de novo malignancies. The 1- and 5-year OS rates after LT in the mTORi group were 83% and 65%, respectively (SLTR group, 85% and 72.6%, respectively); 30.6% patients received mTORi monotherapy, and 38.7% patients had an early switch to mTORi in the first 3 months after oncologic diagnosis. mTORi monotherapy or oncologic treatment strategies had a nonsignificant association with prognosis. The OS rate was higher when the mTORi switch occurred early, 83% and 67%, respectively. Conclusions mTORi-based immunosuppression may be a preferred option in patients transplanted with tumors. The OS rate was comparable to data from the SLTR. An mTORi early switch improves OS rate.

Background A rare but life-threatening cause of pancytopenia after liver transplantation is hemophagocytic syndrome. We present a 48-year-old woman who underwent liver transplantation and developed a hemophagocytic syndrome secondary to Epstein-Barr virus with a fatal course, despite initial treatment with immunosuppressants. The diagnosis was made based on the bone marrow aspiration, in which macrophages with phagocytic activity were observed, and clinical findings. Due to the very poor outcomes and high mortality, in patients with severe pancytopenia hemophagocytic syndrome should be excluded, and a bone marrow aspiration should be considered.

Aim/objective Tectonic penetrating keratoplasty is technically difficult to perform in cases of large corneal perforations. Indeed, severe ocular hypotonia makes it difficult to achieve high-quality trephination. Therefore, it is essential to create a normotensive eye. We investigated the use of a piece of sterile cardboard to seal the globe before recipient trephination. Methods This is a retrospective case series. Patients treated with a new technique of tectonic keratoplasty for the management of large corneal perforations were studied. Main outcome measures were achievement of recipient trephination, preservation of globe integrity preservation and visual acuities. Results This case series included 6 eyes of 6 patients, with a mean age of 51 years (range, 21–79 years). The perforations were 4–7 mm in diameter. Five out of the 6 patients had undergone unsuccessful prior multilayer amniotic membrane transplantations. Mean follow-up period was 14 months (range, 6–24 months). The use of a piece of sterile cardboard to seal the globe made it possible to carry out a circular recipient trephination with a diameter identical to that of the donor corneal graft in all cases. Conjunctival flap and partial tarsorrhaphy were used in three patients and in one patient, respectively. Preservation of globe integrity was achieved in all cases. Visual acuity had improved at the end of follow-up in four patients. Conclusions We describe here a new surgical technique allowing achievement of a circular recipient trephination with a diameter identical to that of the donor corneal graft.

We present the case of a 51-year-old female with a 2-month history of intense anal pain and rectal bleeding. A digital rectal exam revealed a possible lower rectal mass. A colonoscopy was then performed that showed a 5 x 6-cm lesion in the middle rectum and a second 3-cm lesion in the lower rectum, without affecting the anal canal. Multiple biopsies were taken and the histopathologic analysis revealed a moderately differentiated squamous-cell proliferation invading beyond the lamina propria. The CT scan confirmed a middle rectum T4N2bM0 and a lower rectum T3N0M0 synchronous neoplasia. These findings were compatible with a synchronous squamous-cell carcinoma (SCC).

Background & aims The evidence suggests that most vulnerable subjects to COVID-19 infection suffer from patients with comorbidities or immunosuppression, including liver transplant recipients. Liver graft dysfunction may be a rare complication. Some patients complain about the post-COVID-19 syndrome. The aim of this study was to assess medium- and short-term outcomes in liver transplant patients. Patients and methods A retrospective case series was performed at a tertiary referral center. We screened 845 patients who had liver transplant (LT) in our center. All consecutive LT patients with COVID-19 during the Spanish outbreak from March 2020 to April 2021 were included. Demographics, pre-existing comorbidities, clinical and radiological data of COVID-19 infection, complications, and liver graft function were assessed at diagnosis and 3-month follow-up. Results Overall, 20 LT patients were diagnosed with confirmed COVID-19. We included 16 patients that met the inclusion criteria, 8 nonhospitalized (50%) and 8 (50%) hospitalized patients were analyzed. The median follow-up was 5.33 months (IQR 3.06–8.26). One patient died during the follow-up. All patients presented some grade of respiratory or functional symptoms. Dyspnea and fatigue were the most prevalent symptoms during the 3-month follow-up. No liver graft dysfunction were reported despite of partial immunosuppression withdrawal in four patients (25%). One patient had cardiovascular complications. Conclusions Our results suggest the presence of post-COVID-19 syndrome with mild residual physical and psychological dysfunction in this subgroup of patients at 3 months after COVID-19. However, no cases of loss or liver graft dysfunction were reported.

We present the case of a 71-years-old male with a history of pulmonary adenocarcinoma with palliative treatment. He was admitted to our hospital with hematochezia and anemia (Hemoglobin 10.6 g/dl).

Introduccion: la pandemia mundial por SARS-CoV-2 obligo a paralizar las unidades de endoscopia. Previamente a la reanudacion de la actividad endoscopica disenamos un protocolo de valoracion de gastroscopias y colonoscopias, desprogramadas durante la pandemia, denegando las no indicadas y priorizando las indicadas. Metodos: establecimos dos tipos de denegacion: a) contexto covid-19 en ≤ 50 anos sin sintomas de alarma y baja probabilidad de hallazgos endoscopicos relevantes; y b) contexto inadecuado por no ser acordes con las guias o protocolos clinicos. Las denegaciones se archivaron en la historia clinica del paciente. Clasificamos las adecuadas en preferentes, convencionales y seguimiento. Comparamos las denegadas por especialidad. Valoramos los hallazgos de las preferentes. Resultados: valoramos 1.658 peticiones (44 % gastroscopias, 56 % colonoscopias) entre el 16 marzo y el 30 junio de 2020. Se consideraron adecuadas 1.164 (70 %), de ellas preferentes el 8,5 %, convencionales el 48 %, seguimiento el 43 % y no valorables el 0,5 %. Se denegaron 494 (30 %): 20 % “contexto covid-19” y 80 % “contexto inadecuado”. Los motivos de denegacion en las gastroscopias fueron: seguimiento de lesiones (33 %), sintomas insuficientemente estudiados (20 %) y sintomas recidivantes con gastroscopia previa (18 %). Los motivos de denegacion en las colonoscopias fueron: vigilancia pospolipectomia (25 %), cancer colorrectal intervenido (21 %) y antecedentes familiares de cancer (13 %). Encontramos diferencias significativas en la denegacion segun la especialidad: Cirugia General (52 %), Hematologia (37 %) y Atencion Primaria (29 %). Un 31 % de las preferentes mostraron hallazgos relevantes. Conclusiones: un 24 % de nuestras endoscopias son discordantes con las recomendaciones cientificas. Su denegacion y la priorizacion de las adecuadas optimizan la utilizacion de recursos.

The intestinal spirochaetosis is defined as the presence of spirochetes on the colonic surface. We present the case of a 57-years-old male, with a history of 4-5 months of diffuse abdominal pain, watery diarrhoea due to this infection. The colonoscopy revealed a serpiginous ulcer in the cecum. The biopsy was positive for intestinal spirochaetosis. It is rare infection, more common among immunocompromised patients and HIV, with a faecal-oral transmission. Most cases are incidental findings in the endoscopic screening. In symptomatic patients the watery diarrhoea and non-specific abdominal pain are the most common symptoms. The macroscopic appearance on the colonoscopy is often normal or non-specific lesions can be identified. The diagnosis is based on the biopsy with haematoxylin and eosin and the confirmation can be made with a Warthin-Starry stain. In symptomatic patients the metronidazole is the preferred treatment option. Although it is rare infection, clinicians should be aware of it in patients with common gastrointestinal symptoms.

BACKGROUND AND AIMS Nonalcoholic fatty liver disease (NAFLD) is a long-term complication after liver transplantation. Our aims were to determine de-novo-NAFLD at 5-year post-liver transplantation and identify predictive risk factors. METHODS This was a retrospective analysis of de-novo-NAFLD at 5-year post-liver transplantation. NAFLD was defined as the radiological evidence of steatosis. Data from transplanted patients between November 2001 and May 2014 were collected. Noninvasive fibrosis scores were calculated. Predictors of de-novo NAFLD and survival were assessed by multivariate analyses and Kaplan-Meier method. RESULTS A total of 252 liver transplantations were evaluated after applying exclusion criteria, (78.6% men) with 54.9 years old (SD ± 9.5). Prevalence of de-novo NAFLD at 5-year post-liver transplantation was 36.1%. Cardiovascular events were presented in 19.88% and 23.08% of non-NAFLD and NAFLD patients, (P = 0.58). On multivariate analysis, male sex (OR, 5.40; P = 0.001), obesity (OR, 3.72; P = 0.017), metabolic syndrome (OR, 4.69; P

Background Cirrhosis as a result of alcohol-related liver disease is one of the most common indications for liver transplantation (LT) in Spain. Patients presenting for LT should be checked for alcohol abuse in clinical interviews and use of laboratory tests to confirm abstinence. The ethyl-glucuronide (EtG) test is very sensitive and can be positive in urine up to 5 days after consumption. Our main objective is to know the rate of alcohol abstinence by using the urine EtG test in patients evaluated for LT and to assess its correlation with the clinical interviews and laboratory test. Methods We conducted a prospective analysis of the results of the EtG in urine of patients evaluated for LT from January 2017 to March 2019 and its correlation with the medical and psychiatric interviews and with the laboratory test. Results We included 160 patients who were referred to LT evaluation. Among all cases, 84.1% were men, with an average age of 57.8 years. Alcohol-related liver disease was the most frequent cause (64.1%). Urine-EtG was positive in 10 patients (6.2%), 9 of them in patients with ALD and 1 in a patient with hepatitis C virus. The alcohol consumption was recognized by 80% of the patients in the clinical interview. Cases with positive EtG had higher levels of analytical parameters than those with a negative test. Conclusions In our series, 6.2% of patients referred for LT evaluation had recently consumed alcohol. The determination of EtG in urine is probably an effective and objective technique in the detection of alcohol consumption to ensure abstinence in the LT candidates.

INTRODUCTION different endoscopic procedures have been proposed for the management of surgical leaks. Endoscopic internal drainage using trans-fistulary double-pigtail plastic stents has emerged as an alternative strategy, especially in fistulae presenting after laparoscopic gastric sleeve. METHODS a retrospective case series was performed at a single tertiary care center including all upper gastrointestinal post-surgical leaks primarily managed with endoscopic trans-fistulary insertion of double-pigtail plastic stents. Clinical success was defined as the absence of extravasation of oral radiographic contrast and radiological resolution of the collection with adequate oral intake Results: nine patients were included, six (66.6 %) females with a median age of 52.6 years (IQR 47-60). Five cases presented after laparoscopic gastric sleeve, two cases after distal esophagectomies, one after a Roux-en-Y gastric bypass and another one after a pancreaticoduodenectomy. Fistulae measured < 10 mm in five patients (55.6 %) and 10-20 mm in four patients (44.4 %). Six were early leaks. Technical and clinical success was achieved in nine (100 %) and seven (77.8 %) cases, respectively. Seven (77.8 %) patients required ≤ 3 endoscopic procedures. The median hospital stay after the first endoscopic procedure was 12 days (IQR 6.5-17.5 days), while the overall median time until leak healing was 118.5 days (IQR 84.5-170). One patient with a post-esophagectomy intrathoracic leak developed an esophageal-tracheal fistula 37 days after stent deployment. CONCLUSIONS our results support the use of endoscopic internal drainage in postsurgical abdominal leaks, regardless of the type of surgery. Although only two patients with intrathoracic dehiscence were included.

In this work, a quasi-time-optimal, nonlinear state-feedback control for the torsional torque of a two-mass system is proposed. The scheme considers constraints in the stator voltage and currents of the driving machine: a permanent-magnet synchronous motor. Its design is based on results of the general framework of optimal control and leverages the assumption of a bang–bang structure for the actuation. In order to render its implementation feasible, the proposed algorithm exploits the geometrical properties displayed by the system state trajectories in the state space, when steered under a time-optimal regime. Spurious chattering is avoided switching to a smoother linear quadratic regulator, once the state reaches the vicinity of the target. The performance of the proposed controller is validated with experimental results, which consider an external proportional-integral controller for the load speed, tuned for relatively high bandwidth.

Purpose To define the optical coherence tomography (OCT) corneal changes predisposing to acute corneal hydrops among patients with advanced keratoconus. Design Retrospective cohort study. Participants A total of 191 advanced keratoconic eyes from 191 patients with advanced keratoconus cases were studied. Methods Data collected from patients with advanced keratoconus cases were studied during a minimum period of 24 months of follow-up. High-resolution Fourier-domain corneal OCT (5 μm of axial resolution) and corneal topography were performed every 4 months during the follow-up. Several anatomic features at the keratoconus cone were analyzed with OCT, including epithelial and stromal thicknesses, the aspect of Bowman's layer, the presence of Vogt's striae, and stromal opacities. A comparative analysis between anatomic corneal features in eyes that developed corneal hydrops and those that did not develop this complication during the follow-up was performed. Main Outcome Measures Evaluation of anatomic corneal changes at risk of developing a corneal hydrops on the basis of OCT findings. Results Eleven cases of corneal hydrops (5.8%) occurred in our series during a mean follow-up of 30 months (24–36 months). All of these patients were male and younger (23.7±5.9 years) than patients with no acute keratoconus (32.7±11.3 years). Increased epithelial thickening with stromal thinning at the conus and the presence of anterior hyperreflectives at the Bowman's layer level were significantly associated with corneal hydrops, whereas the presence of corneal scarring was a preventive factor. At the healing stage, a pan-stromal scar occurs, with a significant stromal thickening and cornea flattening. Conclusions Increased epithelial thickening, stromal thinning at the keratoconus cone, anterior hyperreflectives at the Bowman's layer level, and the absence of stromal scarring are associated with a high risk of developing corneal hydrops. These aspects should be taken into account by the clinician in the evaluation of keratoconus eyes and in the planning of corneal keratoplasty.

This paper presents the design of a predictive speed controller for electrical drives. The control scheme does not have a cascaded structure; instead, it uses a single optimization algorithm to generate the control action to be applied at the next sampling instant. The control is based on the optimization of a cost function, which is designed using the insight given by the solution of the minimum-time control problem for a simplified system, namely, the double integrator, which is a reasonable model of the machine dynamic behavior. The experimental results obtained with a permanent-magnet synchronous motor and an induction machine, fed by a two-level three-phase inverter, confirm that this approach reaches a very good dynamic performance without a high computational effort.

This paper presents a predictive strategy for the speed control of a two-mass system driven by a permanent magnet synchronous motor (PMSM). The proposed approach allows to manipulate all the system variables simultaneously, including mechanical and electrical variables in a single control law. The state feedback is achieved with a reduced order extended Kalman filter, which observes the non-measured variables as well as reduces the impact of measurement noise. The performance of the control strategy is shown through simulation and experimental results in a 4 [kW] laboratory prototype.

Multilevel converters can reach medium-voltage operation increasing the efficiency of high-power applications. Among the existing multilevel converter topologies, the modular multilevel converter (MMC) provides the advantages of high modularity, availability, and high power quality. Moreover, the main advantage compared to cascaded multilevel converters is the lack of an input transformer which results in a reduction of cooling requirements, size, and cost. One of the drawbacks of this topology when used as an ac-ac converter is the input and output frequency components in the control loop, resulting in a more complex controller design. In this paper, a single-phase ac-ac MMC predictive control approach is proposed. The controller minimizes the input, output, and circulating current errors and balances the dc voltages. Experimental results show the performance of the proposed predictive control scheme.

In this work a position controller for the permanent magnet synchronous motor is developed. The design is based on ideas of time-optimal control and predictive control and considers constraints for both torque and speed. The proposed controller takes the form of a state feedback. Its inputs are the position reference and the system state, and its output is the switching state to be applied by the power converter in the next sampling instant. The design procedure starts by solving a time-optimal control problem for a simple system: the triple integrator. The solution is then used to devise a state feedback rule for the motor. Although the control scheme does not have a completely cascaded structure, the approach taken establishes a hierarchy, with the error in the position having the highest priority. This separates the controller in two main building blocks, which work at different abstraction levels. The purpose of the first block is to generate references for the relevant states of the motor (speed and torque), based on long term predictions, which are realized using the triple integrator model. The second block is a receding horizon controller with a prediction horizon of one time step and a specially devised cost function, for the simultaneous control of speed, torque and stator currents. The performance of the controller is verified with experimental results.

This paper presents the design of a control scheme for the two-mass-system based on the Finite-Set Model Predictive Control method. The whole system state is controlled in a centralized way, so that the problem is solved more holistically, that is to say, using all degrees of freedom available. Constraints in the prediction horizon, given by the limited computation power and speed of the system dynamics, and the consequent myopic perspective of the controller, are solved by means of an ad-hoc cost function. The control is done using measurements of the stator currents and the speed of the driving machine. The rest of the system state is estimated using a Kalman Filter.

Multilevel converters can reach medium-voltage operation, increasing the efficiency in high power applications. Among the existing multilevel converter topologies, modular multilevel converter provides the advantages of high modularity, availability and high power quality. Moreover, the main advantage compared to cascaded multilevel converters is the absence of input transformer; reducing the size, cost and cooling requirements. When used as AC-AC converter, it usually requires a sophisticated controller to decouple the input and output frequency components. In this paper a predictive control approach is proposed to control a single-phase AC-AC modular multilevel converter. The controller minimizes the currents error and keeps the DC voltage balancing featuring a simple implementation, high input power factor and precise control of the output current. Moreover, the DC voltages are kept at the reference value. Simulation results showing the performance of the predictive control scheme are presented.

This paper presents a predictive strategy for the control of a permanent magnet synchronous motor (PMSM). Our approach allows one to simultaneously manipulate speed and electrical variables, without using any auxiliary linear controller. The high sampling rate, characteristic of this technique, and the limited precision of the typical angle measurement devices, present serious difficulties for this technique to work in practice. These issues are dealt with in the paper and a solution based on an extended Kalman filter is proposed. The effectiveness of the proposed approach is evaluated through simulations.