Respuesta a la endotelina-I en arterias humanas de tumores de colon y recto

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Fisiología. Fecha de lectura: 20 de Febrero de 200

Structural and dielectric properties of ultra-fast microwave-processed La_0.3Ca_0.7Fe_0.7Cr_0.3O3-delta ceramics

Perovskite La_0.3Ca_0.7Fe_0.7Cr_0.3O_(3-delta) (LCFCr) is a mixed ionic and electronic conductor (MIEC) that can be employed as an electrode material in reversible solid oxide fuel cells (RSOFCs). In this work, an ultra-fast (15 min) one-step microwave (MW)-assisted combustion synthesis route has been developed to obtain phase pure and highly crystalline LCFCr powder. The synthesized powders exhibited a sponge-like microstructure with increased electrochemical reaction sites. Neutron thermodiffraction analysis revealed a structural transition above 500 degrees C from the room temperature (RT) orthorhombic Pnma to a rhombohedral R3c perovskite phase. The oxygen vacancy concentration was found to increase from delta = 0.272(7) at RT to delta = 0.333(5) at 900 degrees C. Furthermore, a 3-dimensional G-type antiferromagnetic structure was detected at RT. MW-sintering of pressed green ceramic pellets was carried out at 950 degrees C for 1 h, using a MW-transparent quartz fiber crucible or alternatively a SiC crucible acting as a MW-absorber. Impedance spectroscopy data on sintered ceramic pellets revealed electronic inhomogeneity as demonstrated by the occurrence of three dielectric relaxation processes associated with two grain boundary (GB)-like contributions and one bulk. The dielectric inhomogeneity encountered may be restricted to the extrinsic GB areas, which may be rather thin. More homogeneous dielectric properties of the GBs were found in the pellet that was sintered in the SiC crucible

Management of acute diverticulitis with pericolic free gas (ADIFAS). an international multicenter observational study

Background: There are no specific recommendations regarding the optimal management of this group of patients. The World Society of Emergency Surgery suggested a nonoperative strategy with antibiotic therapy, but this was a weak recommendation. This study aims to identify the optimal management of patients with acute diverticulitis (AD) presenting with pericolic free air with or without pericolic fluid. Methods: A multicenter, prospective, international study of patients diagnosed with AD and pericolic-free air with or without pericolic free fluid at a computed tomography (CT) scan between May 2020 and June 2021 was included. Patients were excluded if they had intra-abdominal distant free air, an abscess, generalized peritonitis, or less than a 1-year follow-up. The primary outcome was the rate of failure of nonoperative management within the index admission. Secondary outcomes included the rate of failure of nonoperative management within the first year and risk factors for failure. Results: A total of 810 patients were recruited across 69 European and South American centers; 744 patients (92%) were treated nonoperatively, and 66 (8%) underwent immediate surgery. Baseline characteristics were similar between groups. Hinchey II-IV on diagnostic imaging was the only independent risk factor for surgical intervention during index admission (odds ratios: 12.5, 95% CI: 2.4-64, P =0.003). Among patients treated nonoperatively, at index admission, 697 (94%) patients were discharged without any complications, 35 (4.7%) required emergency surgery, and 12 (1.6%) percutaneous drainage. Free pericolic fluid on CT scan was associated with a higher risk of failure of nonoperative management (odds ratios: 4.9, 95% CI: 1.2-19.9, P =0.023), with 88% of success compared to 96% without free fluid ( P <0.001). The rate of treatment failure with nonoperative management during the first year of follow-up was 16.5%. Conclusion: Patients with AD presenting with pericolic free gas can be successfully managed nonoperatively in the vast majority of cases. Patients with both free pericolic gas and free pericolic fluid on a CT scan are at a higher risk of failing nonoperative management and require closer observation

Implementation of an Enhanced Recovery After Surgery program in elective colorectal surgery: a prospective cohort study

Objective: To evaluate the results of an Enhanced Recovery After Surgery (ERAS) protocol in elective colorectal surgery compared to the historical cohort of this hospital with standard care, in terms of hospital Length Of Stay (LOS), 30 days readmissions rate and 3–5 Clavien–Dindo Complications (CDC). Methodology: Data were collected from consecutive patients during 2 time periods, before (135 patients from hospital database) and after implementation of an ERAS protocol (121 with prospective follow up). Multivariate lineal or logistic regressions were used to assess the impact of ERAS program, adjusting by gender, age, laparoscopy and 3–5 CDC. Results: The two groups were homogeneous in terms of demographic and surgery details, with the exception of the operative approach, with increased use of laparoscopy in the ERAS group. The ERAS protocol decreased LOS (9.8 ± 3.7 vs. 11 ± 3.8, p = 0.018) without increasing 30 days readmission rate or the number of severe CDC. In a multivariate analysis, age and 3–5 CDC were independently associated with a longer LOS while male gender, ERAS protocol and laparoscopic surgery with a decreased LOS. 3–5 CDC increased readmissions (OR = 3.5, 95% CI 1.2–10.2) while laparoscopic surgery decreased them (OR = 0.2, 95% CI 0.1–0.8). ERAS improved compliance with secondary variables in a statistically significant way: more laparoscopic surgery; more regional analgesia in the intraoperative period; earlier adherence to ambulation; faster onset of oral liquid diet and analgesia by mouth; and lower requirements of opioids. Conclusions: ERAS protocol and laparoscopic surgery decreased LOS without increasing 30 days readmission rate. Severe CDC increased LOS and readmissions. Resumo: Objetivo: Avaliar os resultados de um protocolo de recuperação aprimorada após a cirurgia (enhanced recovery after surgery [ERAS]) em cirurgia colorretal eletiva em comparação com a coorte histórica deste hospital, que recebeu o tratamento padrão, em termos de hospitalização, taxa de readmissão de 30 dias e graus 3 a 5 na escala de complicações cirúrgicas de Clavien-Dindo (CCD). Metodologia: Os dados foram coletados de pacientes consecutivos em dois períodos de tempo: antes (135 pacientes do banco de dados do hospital) e depois da implementação de um protocolo ERAS (121 pacientes com acompanhamento prospectivo). Regressões lineares ou logísticas multivariadas foram usadas para avaliar o impacto do protocolo ERAS, ajustando por sexo, idade, uso de laparoscopia e graus 3 a 5 na escala CCD. Resultados: Os dois grupos foram homogêneos em termos de características demográficas e cirúrgicas, com exceção da abordagem operatória, com o aumento do uso de laparoscopia no grupo ERAS. O protocolo ERAS diminuiu o tempo de internação (9,8 ± 3,7 vs. 11 ± 3,8; p = 0,018) sem aumentar a taxa de readmissão de 30 dias ou a severidade na escala CCD. Na análise multivariada, a idade e os graus 3 a 5 na escala CCD foram independentemente associados a uma hospitalização mais longa, enquanto o sexo masculino, o protocolo ERAS e a cirurgia laparoscópica foram independentemente associados a uma hospitalização mais curta. Graus 3 a 5 na escala CCD foram associados a um aumento nas readmissões (OR = 3,5; IC 95%: 1,2–10,2), enquanto a cirurgia laparoscópica foi associada a uma diminuição nesse número (OR = 0,2; IC 95%: 0,1–0,8). O ERAS melhorou a adesão às variáveis secundárias de uma forma estatisticamente significativa: aumento no número de cirurgias laparoscópicas; maior uso de analgesia regional no período intraoperatório; adesão precoce à deambulação; início mais rápido da dieta líquida oral e analgesia por via oral; finalmente, menor uso de opioides. Conclusões: O protocolo ERAS e a cirurgia laparoscópica diminuíram o tempo de internação sem aumentar a taxa de readmissão de 30 dias. Um grau severo na escala CCD aumentou a hospitalização e readmissões. Keywords: Colorectal surgery, Enhanced recovery after surgery, Laparoscopy, Palavras-chave: Cirurgia colorretal, Recuperação aprimorada após a cirurgia, Laparoscopi

Can physiological stimulation prior to ileostomy closure reduce postoperative ileus: a prospective multicenter pilot study

Background The aim of this study was to assess the impact of ileostomy closure following preoperative physiological stimulation (PPS) on postoperative ileus (POI) in patients with loop ileostomy after low anterior resection for rectal cancer. Methods Patients who underwent ileostomy closure between January 2017 and February 2020 in two tertiary referral centers were prospectively included. PPS stimulation was compared to standard treatment. Stimulation was carried out daily during the 15 days prior to ileostomy closure by the patient's self-instillation of 200 ml of fecal contents from the ileostomy bag via the efferent loop, using a rectal catheter. Standard treatment (ST) consisted of observation. Outcomes measures were POI, morbidity, stimulation feasibility, and predictors to ileus. Results A total of 58 patients were included [42 males and 16 females, median age 67 (43–85) years]. PPS was used in 24 patients, who completed the entire stimulation process, and ST in 34 patients. No differences in preoperative factors were found between the two groups. POI was significantly lower in the PPS group (4.2%) vs the ST group (32.4%); p < 0.01, OR: 0.05 (CI 95% 0.01–0.65). The PPS group had a shorter time to restoration of bowel function (1 day vs 3 days) p = 0.02 and a shorter time to tolerance of liquids (1 day vs 2 days), p = 0.04. Age (p = 0.01), open approach at index surgery, p = 0.03, adjuvant capecitabine (p = 0.01). and previous abdominal surgeries (p = 0.02) were associated with POI in the multivariate analysis. C-reactive-protein values on the 3rd (p = 0.02) and 5th (p < 0.01) postoperative day were also associated with POI. Conclusions PPS for patients who underwent ileostomy closure after low anterior resection for rectal cancer is feasible and might reduce POI.Depto. de CirugíaFac. de MedicinaTRUEpu

Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort.

Objective:To develop and validate a prediction model (STOMA score) for 1-year stoma-free survival in patients with rectal cancer (RC) with anastomotic leakage (AL).Background:AL after RC resection often results in a permanent stoma.Methods:This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres and included patients who developed AL after RC surgery between 2014 and 2018. Clinically relevant predictors for 1-year stoma-free survival were included in uni and multivariable logistic regression models. The STOMA score was developed and internally validated in a cohort of patients operated between 2014 and 2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated.Results:This study included 2499 patients with AL, 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA score: sex, age, American Society of Anestesiologist classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction, and reactivation leakage. The STOMA score showed good discrimination and calibration (c-index: 0.71, 95% CI: 0.66-0.76).Conclusions:The STOMA score consists of 18 clinically relevant factors and estimates the individual risk for 1-year stoma-free survival in patients with AL after RC surgery, which may improve patient counseling and give guidance when analyzing the efficacy of different treatment strategies in future studies

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding