Prótesis colónicas en el tratamiento paliativo del cáncer colónico. Nuestra evaluación tras 10 años de experiencia / Self-expanding metal stents in the palliative treatmentof coloncancer. Results of 10 years of experience

Introducción: la colocación de prótesis metálicas autoexpansibles (PAE) por vía endoscópica surge como opción terapéutica para la obstrucción colónica neoplásica en dos situaciones: como tratamiento paliativo y como puente a la cirugía curativa. Este procedimiento evita cirugías en dos tiempos y disminuye la probabilidad de colostomía definitiva y sus complicaciones con el consecuente deterioro de la calidad de vida. Objetivo: comunicar nuestra experiencia en la colocación de PAE para el tratamiento paliativo de la obstrucción colorrectal neoplásica. Diseño: retrospectivo, longitudinal, descriptivo y observacional. Material y métodos: se incluyeron todos los pacientes a quienes el mismo grupo de endoscopistas les colocó PAE con intención paliativa por cáncer colorrectal avanzado entre agosto de 2008 y diciembre de 2019. Fueron analizadas las variables demográficas y clínicas, el éxito técnico y clínico, las complicaciones tempranas y tardías y la supervivencia. Resultados: se colocó PAE en 54 pacientes. La media de edad fue 71 años. El 85% de las lesiones se localizó en el colon izquierdo. En el 57% de los pacientes se realizó en forma ambulatoria. El éxito técnico y clínico fue del 92 y 90%, respectivamente y la supervivencia media de 209 días. La tasa de complicaciones fue del 29,6%, incluyendo un 14,8% de obstrucción y un 5,6% de migración. La mortalidad tardía atribuible al procedimiento fue del 5,6%, ocasionada por 3 perforaciones tardías: 2 abiertas y 1 microperforación con formación de absceso localizado. Conclusiones: la colocación de PAE como tratamiento paliativo de la obstrucción neoplásica colónica es factible, eficaz y segura. Permitió el manejo ambulatorio o con internación breve y la realimentación temprana, mejorando las condiciones para afrontar un eventual tratamiento quimioterápico paliativo. Las mayoría de las complicaciones fueron tardías y resueltas endoscópicamente en forma ambulatoria. (AU)

Introduction: endoscopic placement of self-expanding metal stents (SEMS) emerges as a therapeutic option for neoplastic obstruction of the colon in two situations: as palliative treatment and as a bridge to curative surgery. This procedure avoids two-stage surgeries and reduces the probability of permanent colostomy and its complications with the consequent deterioration in quality of life. Objective: to report our experience in the placement of SEMS as palliative treatment in neoplastic colorectal obstruction. Design: retrospective, longitudinal, descriptive and observational study. Methods: all patients in whom the same group of endoscopists performed SEMS placement with palliative intent for advanced colorectal cancer between August 2008 and December 2019 were analyzed. Data collected were demographic and clinical variables, technical and clinical success, early and late complications, and survival. Results: SEMS were placed in 54 patients. The average age was 71 years. Eighty-five percent were left-sided tumors. In 57% of the patients the procedure was performed on an outpatient basis. Technical and clinical success was 92 and 90%, respectively, and median survival was 209 days. The complication rate was 29.6%, including 14.8% obstruction and 5.6% migration. Late mortality attributable to the procedure was 5.6%, caused by 3 late perforations: 2 open and 1 microperforation with localized abscess formation. Conclusions: The placement of SEMS as a palliative treatment for neoplastic colonic obstruction is feasible, effective and safe. It allowed outpa-tient management or brief hospitalization and early refeeding, improving the conditions to face an eventual palliative chemotherapy treatment. Most complications were late and resolved endoscopically on an outpatient basis. (AU)

Transanal minimally-invasive surgery (TAMIS): experience with no closure of the rectal defect

Background: In transanalminimally-invasive surgery (TAMIS), the closure of the rectal defect is controversial, and endoluminal suture is one of the most challenging aspects. The goal of the present study is to evaluate the short- andmedium-term complications of a consecutive series of patients with extraperitoneal rectal injuries who underwent TAMIS without closure of the rectal defect. Materials and Methods: A prospective, longitudinal, descriptive study conducted between August 2013 and July 2019 in which all patients with extraperitoneal rectal lesions, who were operated on using the TAMIS technique, were consecutively included. The lesions were: benign lesions ≥ 3 cm; neuroendocrine tumors ≤ 2 cm; adenocarcinomas in stage T1N0; and adenocarcinomas in stage T2N0, with high surgical risk, or with the patients reluctant to undergo radical surgery, and others with doubts about complete remission after the neoadjuvant therapy. Bleeding, infectious complications, rectal stenosis, perforations, and death were evaluated. Results: A total of 35 patients were treated using TAMIS without closure of the defect. The average size of the lesionswas of 3.68±2.1 cm(95% confidence interval [95%CI]: 0.7cmto 9 cm), their average distance from the anal margin was of 5.7±1.48cm, and the average operative time was of 39.2±20.5 minutes, with a minimum postoperative follow-up of 1 year. As for the pathologies, they were: 15 adenomas; 3 carcinoid tumors; and 17 adenocarcinomas. In all cases, the rectal defect was left open. The overall morbidity was of 14.2%. Two patients (grade II in the Clavien-Dindo classification) were readmitted for pain treatment, and three patients (grade III in the Clavien-Dindo classification) were assisted due to postoperative bleeding, one of whom required reoperation. Conclusion: The TAMIS technique without closure of the rectal defect yields good results, and present a high feasibility and low complication rate. (AU)

Real-Time Positron Emission Tomography Evaluation of Topotecan Brain Kinetics after Ultrasound-Mediated Blood-Brain Barrier Permeability.

Glioblastoma (GBM) is the most common primary adult brain malignancy with an extremely poor prognosis and a median survival of fewer than two years. A key reason for this high mortality is that the blood-brain barrier (BBB) significantly restricts systemically delivered therapeutics to brain tumors. High-intensity focused ultrasound (HIFU) with microbubbles is a methodology being used in clinical trials to noninvasively permeabilize the BBB for systemic therapeutic delivery to GBM. Topotecan is a topoisomerase inhibitor used as a chemotherapeutic agent to treat ovarian and small cell lung cancer. Studies have suggested that topotecan can cross the BBB and can be used to treat brain metastases. However, pharmacokinetic data demonstrated that topotecan peak concentration in the brain extracellular fluid after systemic injection was ten times lower than in the blood, suggesting less than optimal BBB penetration by topotecan. We hypothesize that HIFU with microbubbles treatment can open the BBB and significantly increase topotecan concentration in the brain. We radiolabeled topotecan with 11C and acquired static and dynamic positron emission tomography (PET) scans to quantify [11C] topotecan uptake in the brains of normal mice and mice after HIFU treatment. We found that HIFU treatments significantly increased [11C] topotecan brain uptake. Moreover, kinetic analysis of the [11C] topotecan dynamic PET data demonstrated a substantial increase in [11C] topotecan volume of distribution in the brain. Furthermore, we found a decrease in [11C] topotecan brain clearance, confirming the potential of HIFU to aid in the delivery of topotecan through the BBB. This opens the potential clinical application of [11C] topotecan as a tool to predict topotecan loco-regional brain concentration in patients with GBMs undergoing experimental HIFU treatments.

Catalytic Nanoassemblies Formed by Short Peptides Promote Highly Enantioselective Transfer Hydrogenation.

Self-assembly enables formation of incredibly diverse supramolecular structures with practically important functions from simple and inexpensive building blocks. Here, we show how a semirational, bottom-up approach to create emerging properties can be extended to a design of highly enantioselective catalytic nanoassemblies. The designed peptides comprising as few as two amino acid residues spontaneously self-assemble in the presence of metal ions to form supramolecular, vesicle-like nanoassemblies that promote transfer hydrogenation of ketones in an aqueous phase with excellent conversion rates and enantioselectivities (>90% ee).

Radiographic scoring system to evaluate union of distal radius fractures.

PURPOSE: To evaluate the intra- and interobserver reliability of a scoring system for distal radius fracture union based on specific radiographic parameters obtainable from x-rays. METHODS: Two sets of 35 anteroposterior and lateral x-rays were obtained by retrospective review of consecutive patients with distal radius fractures (AO types A and C) treated by a single surgeon in 2009. One set was assembled for those patients treated nonsurgically and 1 set for those treated with open reduction and internal fixation (ORIF) with volar plating. Radius union scoring system (RUSS) scores were compiled from a 5-person review panel consisting of hand surgeons and musculoskeletal radiologists. Union of each of the 4 cortices was graded on a 3-point scale (0, fracture line visible with no callus; 1, callus formation but fracture line present; 2, cortical bridging without clear fracture line). Reviewers also recorded their overall impression of fracture union (united or not united). Each set of radiographs was reviewed twice by the 5 reviewers, 2 weeks apart. Inter- and intraobserver reliability were determined using intraclass correlation coefficients. RESULTS: For nonsurgically treated fractures, substantial agreement in union scores was found with regard to both intra- and interobserver reliability. For fractures treated with ORIF, substantial agreement was found in union scores with regard to intraobserver reliability and moderate agreement with regard to interobserver reliability. In addition, when using the reviewers' overall assessment of union as a reference standard, RUSS had a statistically significant predictive value in being able to differentiate between united and not united fractures. CONCLUSIONS: This radiographic union tool demonstrated substantial intra- and interobserver reliability for the determination of fracture union in the distal radius. The RUSS is a simple method for a standardized assessment of radiographic union of DRF treated nonsurgically or with ORIF. TYPE OF STUDY/LEVEL OF EVIDENCE: Economic/decision analysis IV.

[Neoplasic colonic obstruction: resolution with self-expanding metallic stents]. / Obstrucción neoplásica de colon: tratamiento con prótesis autoexpansibles.

INTRODUCTION: The endoscopic placement of self-expanding metallic stents (SEMS) emerges as a therapeutic option for neoplastic colonic obstruction in two situations: as palliative treatment and as a bridge to surgery. The latter can avoid emergency surgery, thus decreasing the rate of ostomies and the mortality and morbidity associated with them. OBJECTIVES: To evaluate the feasibility, safety and benefits of SEMS placement for the treatment of neoplastic colorectal obstruction. MATERIALS AND METHODS: Between August 2008 and June 2012, we included in this prospective, longitudinal, descriptive and observational study all the patients suffering from colorectal neoplasia who were subjected to SEMS placement by the same group ofendoscopists. Nitinol SEMS were inserted under endoscopic vision and radioscopic control. RESULTS: Twenty seven SEMS were inserted in 27 patients, 61% of them were male and the average age was 70 years old. Symptoms of colonic suboclussion or obstruction were found in 92% of patients, 88% of the lesions were located in the left-side colon, 41% of cases were performed on an ambulatory basis and 65% of stenting was carried out for palliative purposes. The average time of hospitalization was 6,46 days. Technical and clinical success were 93% and 100%, respectively. Minor complications were observed in 11% of patients. Colonic stenting was followed by elective surgery within one month, by a laparoscopic technique in most cases. CONCLUSION: The placement of SEMS arises as a safe and effective alternative to palliative surgery or as a bridge to elective surgery.

Obstrucción neoplásica de colon: tratamiento con prótesis autoexpansibles / [Neoplasic colonic obstruction: resolution with self-expanding metallic stents].

INTRODUCTION: The endoscopic placement of self-expanding metallic stents (SEMS) emerges as a therapeutic option for neoplastic colonic obstruction in two situations: as palliative treatment and as a bridge to surgery. The latter can avoid emergency surgery, thus decreasing the rate of ostomies and the mortality and morbidity associated with them. OBJECTIVES: To evaluate the feasibility, safety and benefits of SEMS placement for the treatment of neoplastic colorectal obstruction. MATERIALS AND METHODS: Between August 2008 and June 2012, we included in this prospective, longitudinal, descriptive and observational study all the patients suffering from colorectal neoplasia who were subjected to SEMS placement by the same group ofendoscopists. Nitinol SEMS were inserted under endoscopic vision and radioscopic control. RESULTS: Twenty seven SEMS were inserted in 27 patients, 61

of them were male and the average age was 70 years old. Symptoms of colonic suboclussion or obstruction were found in 92

of the lesions were located in the left-side colon, 41

of cases were performed on an ambulatory basis and 65

of stenting was carried out for palliative purposes. The average time of hospitalization was 6,46 days. Technical and clinical success were 93

, respectively. Minor complications were observed in 11

of patients. Colonic stenting was followed by elective surgery within one month, by a laparoscopic technique in most cases. CONCLUSION: The placement of SEMS arises as a safe and effective alternative to palliative surgery or as a bridge to elective surgery.