Single Entity Electrocatalysis.

Making a measurement over millions of nanoparticles or exposed crystal facets seldom reports on reactivity of a single nanoparticle or facet, which may depart drastically from ensemble measurements. Within the past 30 years, science has moved toward studying the reactivity of single atoms, molecules, and nanoparticles, one at a time. This shift has been fueled by the realization that everything changes at the nanoscale, especially important industrially relevant properties like those important to electrocatalysis. Studying single nanoscale entities, however, is not trivial and has required the development of new measurement tools. This review explores a tale of the clever use of old and new measurement tools to study electrocatalysis at the single entity level. We explore in detail the complex interrelationship between measurement method, electrocatalytic material, and reaction of interest (e.g., carbon dioxide reduction, oxygen reduction, hydrazine oxidation, etc.). We end with our perspective on the future of single entity electrocatalysis with a key focus on what types of measurements present the greatest opportunity for fundamental discovery.

Voltage-driven ion flux promotes emulsification at the water|oil interface.

Emulsions are critical across a vast range of industries. Generally, emulsion synthesis is a complicated chemical process, requiring many mixed-phase systems. Here, we demonstrate that the flux of ions across the oil|water interface induces emulsification. Ion flux is achieved by a voltage-driven process, where an anode and a cathode are placed in each phase. When a current density of 2 mA cm-2 is reached across the interface, emulsification occurs. We demonstrate that emulsification can be tuned to occur in both phases, depending on the ions present. Droplet sizes are on the order of hundreds of nm and are stable for over an hour even without purposefully added surfactant. We demonstrate qualitative control over droplet size and charge based on salt content, current densities, and polarity of the interface. The process is 1000 times less energetic than ultrasonication. Our results introduce a robust and low-energy means of nanodroplet dispersion without the use of more than two phases and complex phase-transfer agents.

Interfacial solute flux promotes emulsification at the water|oil interface.

Emulsions are critical across a broad spectrum of industries. Unfortunately, emulsification requires a significant driving force for droplet dispersion. Here, we demonstrate a mechanism of spontaneous droplet formation (emulsification), where the interfacial solute flux promotes droplet formation at the liquid-liquid interface when a phase transfer agent is present. We have termed this phenomenon fluxification. For example, when HAuCl4 is dissolved in an aqueous phase and [NBu4][ClO4] is dissolved in an oil phase, emulsion droplets (both water-in-oil and oil-in-water) can be observed at the interface for various oil phases (1,2-dichloroethane, dichloromethane, chloroform, and nitrobenzene). Emulsification occurs when AuCl4- interacts with NBu4+, a well-known phase-transfer agent, and transfers into the oil phase while ClO4- transfers into the aqueous phase to maintain electroneutrality. The phase transfer of SCN- and Fe(CN)63- also produce droplets. We propose a microscopic mechanism of droplet formation and discuss design principles by tuning experimental parameters.

Time evolution of cytokine profiles associated with mortality in COVID-19 hospitalized patients.

Background: High cytokine levels have been associated with severe COVID-19 disease. Although many cytokine studies have been performed, not many of them include combinatorial analysis of cytokine profiles through time. In this study we investigate the association of certain cytokine profiles and its evolution, and mortality in SARS-CoV2 infection in hospitalized patients. Methods: Serum concentration of 45 cytokines was determined in 28 controls at day of admission and in 108 patients with COVID-19 disease at first, third and sixth day of admission. A principal component analysis (PCA) was performed to characterize cytokine profiles through time associated with mortality and survival in hospitalized patients. Results: At day of admission non-survivors present significantly higher levels of IL-1α and VEGFA (PC3) but not through follow up. However, the combination of HGF, MCP-1, IL-18, eotaxine, and SCF (PC2) are significantly higher in non-survivors at all three time-points presenting an increased trend in this group through time. On the other hand, BDNF, IL-12 and IL-15 (PC1) are significantly reduced in non-survivors at all time points with a decreasing trend through time, though a protective factor. The combined mortality prediction accuracy of PC3 at day 1 and PC1 and PC2 at day 6 is 89.00% (p<0.001). Conclusions: Hypercytokinemia is a hallmark of COVID-19 but relevant differences between survivors and non-survivors can be early observed. Combinatorial analysis of serum cytokines and chemokines can contribute to mortality risk assessment and optimize therapeutic strategies. Three clusters of cytokines have been identified as independent markers or risk factors of COVID mortality.

The electrodeposition of gold nanoparticles from aqueous nanodroplets.

Nanodroplet-mediated electrodeposition is a reliable method for electrodepositing nanoparticles by confining a small amount of metal-salt precursor in water nanodroplets (radius ∼400 nm) suspended in an oil continuous phase. This technique provides a great advantage in terms of nanoparticle size, morphology, and porosity. For an electrochemical reaction to proceed in the aqueous nanodroplet, the electroneutrality condition must be maintained. Classically, [NB4][ClO4] or a comparable salt is added to the oil continuous phase to maintain charge balance. Unfortunately, the presence of this salt in the oil phase causes some metal salts, such as HAuCl4, to phase transfer, disallowing the formation of gold nanoparticles. Here, we demonstrate the partitioning of HAuCl4 is orders of magnitude lower using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) when LiClO4 is added to the nanodroplet phase and [NBu4][ClO4] is not added to the continuous phase. This simple change allows for the electrodeposition of gold nanoparticles. Scanning electron microscopy shows the morphology and size distribution of gold nanoparticles obtained at different concentrations of LiClO4. Transmission electron microscopy in selected diffraction mode was used and it determined the gold nanoparticles obtained are polycrystalline with miller indices of (222) and (200). This work widens the variety of nanoparticles that can be electrodeposited from nanodroplets for applications in energy storage and conversion, photoelectrochemistry, and biosensing.

Influence of water erosion on fire hazards in a coal waste dump - A case study.

Dump fires are a significant environmental problem in post-mining areas. The TEXMIN project has shown that climate change could lead to more extreme weather events in the future, intense precipitation among them. The impact of water erosion on the development of endogenous fires in coal waste heaps has not been investigated thus far. Meteorological data collected from the studied dump area in Libiaz, Poland confirmed that heavy rainfall occurred many times, causing surface erosion on the slope. Gully erosion was observed on the western slope of the heap, the depth of which was up to 1.6 m. Data showed that between areas with and without water erosion, there was a significant difference in measured temperatures and gas concentrations that defined the fire intensity. Erosion facilitated self-heating such that internal temperatures increased to 52.9 °C. Further, at a depth of 1 m in the self-heating zone, maximum gas concentrations were 15.65 vol%. CO2, 10 ppm CO, and 0.435 vol%. CH4, while the O2 concentration dropped below 1.0 vol%. These results show that despite preventative measures, thermal activity reactivated in the vicinity of gully erosion and caused the self-heating zone to expand.

Increased Expression of TLR4 in Circulating CD4+T Cells in Patients with Allergic Conjunctivitis and In Vitro Attenuation of Th2 Inflammatory Response by Alpha-MSH.

Ocular allergic diseases are frequently seen in ophthalmological clinical practice. Immunological damage is mediated by a local Th2 inflammatory microenvironment, accompanied by changes in circulating cell subsets, with more effector cells and fewer T regulatory cells (Tregs). This study aimed to evaluate the involvement of toll-like receptor 4 (TLR4) and α-melanocyte stimulating hormone (α-MSH) in the immune regulation associated with perennial allergic conjunctivitis (PAC). We performed an Ag-specific stimulation during 72 h of culturing with or without lipopolysaccharide (LPS) or α-MSH in peripheral blood mononuclear cells (PBMC), analyzing the cell subsets and cytokines induced by the stimuli. We also determined α-MSH in tear samples from healthy donors (HD) or PAC patients. Our findings demonstrate an immunological dysregulation characterized by an increased frequency of CD4+TLR4+ in the PBMC of patients with PAC, compared to HD. Most of these CD4+TLR4+ cells were also CD25+, and when α-MSH was added to the culture, the percentage of CD4+CD25+FoxP3+ increased significantly, while the percentage of CD69+ cells and cytokines IL-4 and IL-6 were significantly decreased. In tears, we found an increased concentration of α-MSH in PAC patients, compared with HD. These findings indicate a novel mechanism involved in controlling ocular allergic diseases, in which α-MSH diminishes the concentration of IL-6 and IL-4, restoring the frequency of Tregs and down-regulating CD4 activation. Moreover, we demonstrated the involvement of CD4+TLR4+ cells as an effector cell subset in ocular allergy.

Right versus left laparoscopic colectomy for colon cancer: does side make any difference?

PURPOSE: To compare the intraoperative and postoperative outcomes between right laparoscopic colectomy (RLC) and left laparoscopic colectomy (LLC) for colon cancer. METHOD: Patients who underwent elective RLC or LLC for colon cancer between January 2004 and December 2014 were identified and elected for a retrospective analysis. Primary outcomes were technical difficulty (including operative time, intraoperative complications, and conversion rate) and postoperative outcome (including postoperative complications, length of hospital stay, reinterventions, readmissions, and mortality). RESULTS: A total of 547 patients (mean age: 68.5 years old; 48.4% males) were analyzed. The RLC group had a higher mean age (71 vs 65; p < 0.001), ASA 3/4 grade (36 vs 26%; p = 0.02), and comorbidity rate (61 vs 48%, p = 0.003). Regarding technical difficulty, no difference was found between the groups in intraoperative complications (4.1 vs 5.9%; p = 0.34) or conversion rate (6.2 vs 3.9%, p = 0.24). Mean operative time was significantly shorter for RLC (162 vs 185 min, p < 0.001). Regarding postoperative outcome, the RLC group had a higher overall morbidity (20.5 vs 13.3%, p = 0.03), ileus (10.6 vs 2.4%, p < 0.001), and a longer hospital stay (4.7 vs 3.9 days, p = 0.003), with no differences regarding reoperations, readmissions, or mortality. The multivariate analysis showed that RLC were independently associated with a longer operative time and postoperative ileus. CONCLUSIONS: RLC for colon cancer was independently associated with a shorter operative time, an increased risk of ileus, and a longer hospital stay than left laparoscopic colectomy in high-volume centers.

Cáncer de recto localmente avanzado: resultados preliminares de la preservación del recto después de quimiorradioterapia neoadyuvante / Locally advanced rectal cancer: Preliminary results of rectal preservation after neoadjuvant chemoradiotherapy

Introducción: El estándar de tratamiento del cáncer de recto localmente avanzado es la escisión total del mesorrecto. Sin embargo, la preservación del órgano ha sido propuesta para los tumores con buena respuesta al tratamiento neoadyuvante. El objetivo de este estudio es investigar los resultados oncológicos de esta estrategia. Métodos: Se realizó un estudio de cohorte retrospectivo, en el que se analizó a los pacientes con adenocarcinoma de recto tratados con intención curativa entre 2005 y 2014 que, después de recibir quimiorradioterapia neoadyuvante, presentaron una respuesta clínica completa o casi completa y fueron tratados con preservación del recto. Resultados: Durante el periodo de estudio, 204 pacientes con cáncer del recto recibieron neoadyuvancia. Treinta (14,7%) presentaron una respuesta clínica completa o casi completa y se trataron según una estrategia de preservación de órgano (23 watch & wait y 7 resecciones locales). La mediana de seguimiento fue de 46 meses (rango intercuartil: 30-68). En el grupo de watch & wait, 4 casos presentaron recurrencia local antes del año (tasa actuarial 18,5%). Todos pudieron ser rescatados (2 con cirugía radical y 2 con resecciones locales) sin presentar nuevas recurrencias. El índice de supervivencia libre de enfermedad a distancia a 3 años fue de 94,1% (IC 95%: 82,9-100). De los 7 casos que se trataron mediante resección local, ninguno presentó recurrencia local. Considerando toda la muestra, la proporción de conservación de órgano fue del 93%. Conclusiones: La estrategia de preservación de órgano en el cáncer rectal localmente avanzado es factible en casos con buena respuesta a la neoadyuvancia. Implementada en un grupo altamente seleccionado de pacientes, se asocia con resultados oncológicos satisfactorios (AU)

Introduction: The standard treatment for locally advanced rectal cancer is total mesorectal excision. However, organ preservation has been proposed for tumors with good response to neoadjuvant treatment. The aim of this study was to evaluate the oncologic results of this strategy. Methods: This is a retrospective cohort study (2005-2014) including a consecutive series of patients with rectal adenocarcinoma with complete or almost complete clinical response after preoperative chemo-radiotherapy, that were treated according to a strategy of preservation of the rectum. Results: A total of 204 patients with rectal cancer received neoadjuvant therapy. Thirty (14.7%) had a good response and were treated with rectal preservation (23 «Watch and Wait» and 7 local resections). Median follow-up was 46 months (interquartile range: 30-68). In the group of «Watch & Wait», 4 patients had local recurrence before 12 months (actuarial local recurrence rate = 18.5%). All of them underwent salvage surgery (2 with radical surgery and 2 local resections) without any further recurrence. Disease-free survival actuarial rate at 3 years follow-up was 94.1% (95% CI 82.9-100). None of the 7 patients that were treated by local excision had local recurrence. The organ preservation rate for the whole group was 93%. Conclusion: The strategy of organ preservation in locally advanced rectal cancer is feasible in cases with good response to neoadjuvant therapy. When implemented in a highly selected group of patients this strategy is associated with satisfactory oncologic results (AU)

Locally advanced rectal cancer: Preliminary results of rectal preservation after neoadjuvant chemoradiotherapy. / Cáncer de recto localmente avanzado: resultados preliminares de la preservación del recto después de quimiorradioterapia neoadyuvante.

INTRODUCTION: The standard treatment for locally advanced rectal cancer is total mesorectal excision. However, organ preservation has been proposed for tumors with good response to neoadjuvant treatment. The aim of this study was to evaluate the oncologic results of this strategy. METHODS: This is a retrospective cohort study (2005-2014) including a consecutive series of patients with rectal adenocarcinoma with complete or almost complete clinical response after preoperative chemo-radiotherapy, that were treated according to a strategy of preservation of the rectum. RESULTS: A total of 204 patients with rectal cancer received neoadjuvant therapy. Thirty (14.7%) had a good response and were treated with rectal preservation (23 «Watch and Wait¼ and 7 local resections). Median follow-up was 46 months (interquartile range: 30-68). In the group of «Watch & Wait¼, 4 patients had local recurrence before 12 months (actuarial local recurrence rate=18.5%). All of them underwent salvage surgery (2 with radical surgery and 2 local resections) without any further recurrence. Disease-free survival actuarial rate at 3 years follow-up was 94.1% (95% CI 82.9-100). None of the 7 patients that were treated by local excision had local recurrence. The organ preservation rate for the whole group was 93%. CONCLUSION: The strategy of organ preservation in locally advanced rectal cancer is feasible in cases with good response to neoadjuvant therapy. When implemented in a highly selected group of patients this strategy is associated with satisfactory oncologic results.

Extensive mesenteric lipodystrophy of the left colon: case report and brief review of the literature.

Mesenteric lipodystrophy is a rare inflammatory process that predominantly affects mesenteric adipose tissue of the small bowell. Several mechanisms have been suggested as responsible for this entity although the precise etiolog remains unknown. The diagnosis is based on CT or MRI imaging and generally confirmed by surgical biopsies. Treatment is individualized and empiric and depends on disease stage and symptoms. We report a case of a 35-year-old male who was admitted to our hospital with a history of abdominal pain, constipation and a palpable mass in the left lower quadrant. Abdominal CT scan showed diffuse thickening of the descending and rectosigmoid colon, associated with increased density of the mesenteric fat. After failure ofan initial treat- ment with glucocorticoids, he underwent a laparoscopic sigmoidectomy. Histopatholog analysis revealed extensive stea- tonecrosis ofpericolonicfat and lipid-ladenfoamy cells which was consistent with the diagnosis of mesenteric lipodystrophy. Clinical presentation and treatment as well as a brief review of the literature are discussed.

[Magnetic resonance and extramural vascular invasion in patients with rectal cancer and liver metastases]. / Resonancia magnética e invasión vascular extramural en pacientes con cáncer rectal y metástasis hepaticas.

BACKGROUND: Extramural vascular invasion (EMVI) in patients with rectal cancer (RC) is associated with more locally advanced tumors, and independently predicts local and distant recurrence and poor overall survival. OBJETIVE: To determine the association between EMVI and synchronous liver metastases in patients with RC. METHODS: We performed a retrospective cohort study including patients with cancer of middle and lower rectum, which were evaluated with magnetic resonance (MRI) for initial staging in the period from January 2011 to January 2012 inclusive. All patients were evaluated with MRI for EMVI and were followed for a year to detect synchronous liver metastases by imaging methods (January 2012 to January 2013 inclusive). Multivariate analysis was performed by logistic regression. RESULTS: We included 68 patients. Twenty had liver metastases during the observation period (29.41%), of whom 15 had signs of MRI EMVI (75%). The incidence of synchronous liver metastases had a marginally significant association with the presence of EMVI (RR 3.35, 95% CI: 1.0001-11.2187, P = 0.050). CONCLUSION: The presence of MRI EVMI is a poor prognostic predictor factor of development of synchronous liver metastases in patients with RC.

Associated liver and multivisceral resections: should we extend the frontiers of resectability?

Combined liver and multivisceral resections (CLMVRs) are rare procedures that demand extensive surgical skills. Few reports have discussed the benefit of these complex procedures and their indications are poorly defined. The aim of the present study is to present short- and long-term results of CLMVRs in primary and metastatic malignancies, including a risk analysis for perioperative morbidity and mortality. A review of our prospective surgical database between November 2007 and August 2013 identified 21 patients who had undergone CLMVRs. Preoperative radiologic evaluation and laboratory data, intraoperative results, hospital outcomes, and long-term follow-up were analyzed. CLMVRs were performed due to metastatic disease from different sites in 17 patients, and due to direct local invasion of the liver in the remaining 4 cases. Major hepatectomy was performed in 7 cases. Morbidity was 57% and 90-day postoperative mortality was 9%. Gender and resection of more than 4 organs were found as statistically significant risk factors to develop major complications. Five of 7 patients with 4 or more organs resected presented major complications including mortality (p = 0.026). The overall 1- and 3-year survival rates were 57 and 24%, respectively. Patients undergoing CLMVRs experience acceptable postoperative morbidity and mortality rates. Surgery should be performed only in carefully selected patients, considering their preoperative comorbidities, and in high-volume centers.

Laparoscopic peritoneal lavage for Hinchey III diverticulitis: is it as effective as it is applicable?

BACKGROUND: Over the past few years, the laparoscopic peritoneal lavage has emerged as a therapeutic alternative to standard resection procedures. However, its effectiveness and applicability remain debatable. OBJECTIVE: The aim of this study was to assess laparoscopic lavage in controlling abdominal sepsis secondary to purulent peritonitis. DESIGN: This study was conducted as a retrospective analysis of prospectively collected data. SETTING: This study was conducted at a single tertiary care institution. PATIENTS: Patients requiring emergency surgery for perforated diverticulitis and generalized peritonitis between June 2006 and June 2013 were identified from a prospective database. Laparoscopic assessment was considered in all of the hemodynamically stable patients, and laparoscopic lavage was performed according to intraoperative strict criteria. MAIN OUTCOME MEASURES: Primary outcomes were the effectiveness and applicability of laparoscopic lavage. Secondarily, feasibility, morbidity, and mortality were also assessed. RESULTS: Seventy-five patients required emergency surgery for generalized peritonitis secondary to perforated diverticulitis. Forty-six patients who underwent laparoscopy presented a purulent generalized (Hinchey III) peritonitis and were examined under the intention-to-treat basis to perform a laparoscopic lavage. Thirty-two patients (70.0%; 95% CI 56.2-82.7) had no previous episodes of diverticulitis. Thirty-six patients (78.0%; 95% CI 66.3-90.1) had free air on a CT scan. The conversion rate was 4% (95% CI 0-10). The feasibility of the method was 96.0% (95% CI 90.4-100), and its applicability was 59.0% (95% CI 44.8-73.2). Median operative time was 89 minutes (range, 40-200 minutes). Postoperative morbidity was 24.0% (95% CI 11.7-36.3), and the mortality rate was 0%. We registered 5 failures, and all of them underwent reoperation. The effectiveness of the procedure was 85% (95% CI 76-93). LIMITATIONS: This was a single-institution retrospective study. CONCLUSIONS: The effectiveness of laparoscopic lavage seems to be high. Although its applicability is lower, it could be applied in more than half of patients requiring emergency surgery. This alternative strategy should be considered when laparoscopic assessment reveals Hinchey III diverticulitis.

Laparoscopic colorectal resections: a simple predictor model and a stratification risk for conversion to open surgery.

BACKGROUND: The advantages associated with the laparoscopic approach are lost when conversion is required. Available predictive models have failed to show external validation. Body surface area is a recently described risk factor not included in these models. OBJECTIVE: The aim of this study was to develop a clinical rule including body surface area for predicting conversion in patients undergoing elective laparoscopic colorectal surgery. DESIGN: This was a prospective cohort study. SETTING: This study was conducted at a single large tertiary care institution. PATIENTS: Nine hundred sixteen patients (mean age, 63.9; range, 14-91 years; 53.2% female) who underwent surgery between January 2004 and August 2011 were identified from a prospective database. MAIN OUTCOME MEASURES: Conversion rate was analyzed related to age, sex, obesity, disease location (colon vs rectum), type of disease (neoplastic vs nonneoplastic), history of previous surgery, and body surface area. A predictive model for conversion was developed with the use of logistic regression to identify independently associated variables, and a simple clinical prediction rule was derived. Internal validation of the model was performed by using bootstrapping. RESULTS: The conversion rate was 9.9% (91/916). Rectal disease, large patient size, and male sex were independently associated with higher odds of conversion (OR, 2.28 95%CI, 1.47-3.46]), 1.88 [1.1-3.44], and 1.87 [1.04-3.24]). The prediction rule identified 3 risk groups: low risk (women and nonlarge males), average risk (large males with colon disease), and high risk (large males with rectal disease). Conversion rates among these groups were 5.7%, 11.3%, and 27.8% (p < 0.001). Compared with the low-risk group, ORs for average- and high-risk groups were 2.17 (1.30-3.62, p = 0.004) and 6.38 (3.57-11.4, p < 0.0001). LIMITATIONS: The study was limited by the lack of external validation. CONCLUSION: This predictive model, including body surface area, stratifies patients with different conversion risks and may help to inform patients, to select cases in the early learning curve, and to evaluate the standard of care. However, this prediction rule needs to be externally validated in other samples (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A137).

Tratamiento laparoscópico del cáncer de recto: resultados oncológicos a largo plazo / Laparoscopic treatment of rectal cancer: long-term results

Antecedentes: Si bien la factibilidad del tratamiento laparoscópico del cáncer de recto ha sido previamente descripta, su aplicación masiva continúa siendo controversial y los resultados oncológicos a largo plazo son aun limitados.Objetivo: Analizar los resultados peri operatorios, la tasa de recurrencia local y la sobrevida alejada a cinco años en pacientes con cáncer de recto operados por vía laparoscópica, y comparar la sobrevida de los pacientes operados por vía laparoscópica con la de aquellos que debieron ser convertidos.Diseño: Observacional retrospectivoLugar de aplicación: Hospital Privado UniversitarioMétodo: Se analizaron 164 pacientes portadores de cáncer de recto operados por vía laparoscópica pura entre enero de 2005 y diciembre de 2011. Los datos clínicos, anatomopatológicos y oncológicos, fueron ingresados prospectivamente en una base de datos. La supervivencia global y libre de enfermedad a 5 años fue calculada según el método actuarial de Kaplan-Meier.Resultados: El 66% de la población presentó tumores de recto medio (n=76) e inferior (n=32), y el 26% (n= 43) recibió tratamiento neoadyuvante. La tasa de preservación esfinteriana fue del 95%. La mediana de la altura de la anastomosis fue de 5 cm (rango: 2 a 12), empleando un reservorio colónico en "J" en el 8,5%. El índice de conversión global fue del 14,6%. La morbilidad y mortalidad global fue 19,5% y 0% respectivamente. La mediana de estadía hospitalaria fue 3 días (r: 2-28). No se registró compromiso de los márgenes quirúrgicos. La media de ganglios linfáticos analizados fue de 15 (rango: 0 - 56). La distribución por estadíos de acuerdo al TNM fue del 3,8% para el estadío 0, 37,8% para el estadío I, 22,5% para el estadío II, 29,2% para el estadío III y 6,7% para el estadío IV. El seguimiento promedio fue de 25 meses (rango: 3 a 81). La tasa de recurrencia local de la serie fue del 1,2% (dos pacientes)...

Background: Even though the laparoscopic approach for rectal cancer has been previously described, its extended application is still controversial and the long-term oncological results are limited.Objective: To analyze the surgical results, local recurrence rate and 5-year survival in patients with rectal cancer operated on by laparoscopy. Secondarily, to compare the survival of patients operated on by laparoscopy with those who required conversion to open surgery.Setting: Private University Hospital Design: Retrospective observational.Material and Methods: One hundred and sixty four consecutive patients undergoing laparoscopic surgery for rectal cancer were analyzed between January 2005 and December 2011. The clinical, pathological and oncological data were collected into a database. Overall and disease free survival at 5 years was estimated by Kaplan-Meier method.Results: 66% of patients had tumors in middle (n=76) and low (n=32) rectum, and 26% (n=43) received neoadjuvant therapy. The sphincter preservation rate was 95%. The median distance between the anastomosis and the anal verge was 5 cm (range: 2 - 12), and a "j" pouch was performed in 8.5%. The overall conversion rate to open surgery was 14.6%. The morbidity and mortality was 19.5% and 0% respectively. The median hospital stay was 3 days (range: 2-28). Surgical margins were negative. The median of lymph nodes harvested was 15 (range: 0-56). According to TNM staging, there were 3.8% for stage 0, 37.8 for stage I, 22.5% for stage II, 29,2% for stage III and 6.7 for stage IV. The median follow up time was 25 months (range: 3-81). The overall local recurrence rate was 1.2% (two patients)...

Tratamiento Laparoscópico del Cáncer de Recto: Resultados Oncológicos a Largo Plazo / Laparoscopic treatment of rectal cancer: long-term results

Antecedentes: Si bien la factibilidad del tratamiento laparoscópico del cáncer de recto ha sido previamente descripta, su aplicación masiva continúa siendo controversial y los resultados oncológicos a largo plazo son aun limitados. Objetivo: Analizar los resultados peri operatorios, la tasa de recurrencia local y la sobrevida alejada a cinco años en pacientes con cáncer de recto operados por vía laparoscópica, y comparar la sobrevida de los pacientes operados por vía laparoscópica con la de aquellos que debieron ser convertidos. Diseño: Observacional retrospectivo Lugar de aplicación: Hospital Privado Universitario Método: Se analizaron 164 pacientes portadores de cáncer de recto operados por vía laparoscópica pura entre enero de 2005 y diciembre de 2011. Los datos clínicos, anatomopatológicos y oncológicos, fueron ingresados prospectivamente en una base de datos. La supervivencia global y libre de enfermedad a 5 años fue calculada según el método actuarial de Kaplan-Meier. Resultados: El 66% de la población presentó tumores de recto medio (n=76) e inferior (n=32), y el 26% (n= 43) recibió tratamiento neoadyuvante. La tasa de preservación esfinteriana fue del 95%. La mediana de la altura de la anastomosis fue de 5 cm (rango: 2 a 12), empleando un reservorio colónico en "J" en el 8,5%. El índice de conversión global fue del 14,6%. La morbilidad y mortalidad global fue 19,5% y 0% respectivamente. La mediana de estadía hospitalaria fue 3 días (r: 2-28). No se registró compromiso de los márgenes quirúrgicos. La media de ganglios linfáticos analizados fue de 15 (rango: 0 - 56). La distribución por estadíos de acuerdo al TNM fue del 3,8% para el estadío 0, 37,8% para el estadío I, 22,5% para el estadío II, 29,2% para el estadío III y 6,7% para el estadío IV. El seguimiento promedio fue de 25 meses (rango: 3 a 81). La tasa de recurrencia local de la serie fue del 1,2% (dos pacientes). La sobrevida global y libre de enfermedad a cinco años fue del 88% (IC 95%: 76-99) y 83% (IC 95%: 72-95) respectivamente. La sobrevida global a 5 años de los pacientes convertidos versus lo no convertidos, fue del 83,3% y 94% respectivamente (p= NS). Conclusiones: El tratamiento laparoscópico del cáncer de recto es oncologicamente seguro. No ha afectado la calidad de las piezas quirúrgicas obtenidas ni los resultados oncológicos a largo plazo. La sobrevida global de los pacientes convertidos resultó equivalente a la de los operados en forma laparoscópica.(AU)

Background: Even though the laparoscopic approach for rectal cancer has been previously described, its extended application is still controversial and the long-term oncological results are limited. Objective: To analyze the surgical results, local recurrence rate and 5-year survival in patients with rectal cancer operated on by laparoscopy. Secondarily, to compare the survival of patients operated on by laparoscopy with those who required conversion to open surgery. Setting: Private University Hospital Design: Retrospective observational. Material and Methods: One hundred and sixty four consecutive patients undergoing laparoscopic surgery for rectal cancer were analyzed between January 2005 and December 2011. The clinical, pathological and oncological data were collected into a database. Overall and disease free survival at 5 years was estimated by Kaplan-Meier method. Results: 66% of patients had tumors in middle (n=76) and low (n=32) rectum, and 26% (n=43) received neoadjuvant therapy. The sphincter preservation rate was 95%. The median distance between the anastomosis and the anal verge was 5 cm (range: 2 - 12), and a "j" pouch was performed in 8.5%. The overall conversion rate to open surgery was 14.6%. The morbidity and mortality was 19.5% and 0% respectively. The median hospital stay was 3 days (range: 2-28). Surgical margins were negative. The median of lymph nodes harvested was 15 (range: 0-56). According to TNM staging, there were 3.8% for stage 0, 37.8 for stage I, 22.5% for stage II, 29,2% for stage III and 6.7 for stage IV. The median follow up time was 25 months (range: 3-81). The overall local recurrence rate was 1.2% (two patients). The overall and disease free 5-year survival was 88% (IC 95%: 76-99) and 83% (IC 95%: 72-95) respectively. The overall 5-year survival of patients operated on by laparoscopy and those who required conversion to open surgery was 83.3% and 94%, respectively (p= NS). Conclusions: The laparoscopic approach for rectal cancer is safe. It does not affect the quality of the specimens and the oncological long-term outcomes. The 5-year overall survival of converted patients to open surgery is similar to the laparoscopic group.(AU)

[Robotic total mesorectal excision for rectal cancer]. / Resección total de mesorrecto robótica por cáncer de recto.

Laparoscopic total mesorectal excision (TME) has proven to be feasible and safe. However, it represents a major technical challenge, since it involves the dissection of the rectum in a confined space such as the bony pelvis using un-ergonomic surgical devices. This difficulty is accentuated in patients with distal tumors and high body mass index (BMI), in which the surgical margins and the hypogastric nerves may be affected. Therefore, robotic surgery aims to overcome these limitations that conspire against the mininvasive surgical approach of rectal cancer. We present an obese (BMI = 32 kg/m2) 82-year-old man with a history of smoking and prostate cancer that was recently diagnosed with a middle rectal adenocarcinoma at 9 cm from the anal verge. Rectal examination evidenced a mobile lesion. Computed tomography scan ruled out metastases and at the local staging by MRI, the tumor was considered as T3-N0 with free circumferential margins. Surgical treatment was decided and a hybrid technique was used combining an initial laparoscopic approach followed by the robotic TME. The patient had a full recovery and was discharged three days after surgery without complications. Pathological examination revealed a low-grade adenocarcinoma with mesorectal invasion, free circumferential and distal margins, and 24 negative lymph nodes (pT3-pN0-pM0/Stage II). Robotic TME was performed safely in an obese patient. It facilitated dissection maneuvers in a confined space with proper identification and preservation of the hypogastric nerves, allowing retrieving an intact mesorectum. Prospective randomized trials will define the role of this new technology.

Two-day hospital stay after laparoscopic colorectal surgery under an enhanced recovery after surgery (ERAS) pathway.

BACKGROUND: The present study aims to examine the feasibility and safety of a two-day hospital stay after laparoscopic colorectal resection (LCR) under an enhanced recovery after surgery (ERAS) pathway. METHODS: Between 2003 and 2010, 882 consecutive patients undergoing LCR were analyzed. Patients were grouped and analyzed according to whether their hospital stay was 2 days (group A) or longer (group B). Demographic, surgical, and postoperative data were compared. To identify independent predictive factors related to a short hospital stay, a multivariate analysis was also performed. RESULTS: Group A represented 10.3 % of this series (91 patients). There were no differences regarding age, gender, BMI, ASA, and previous abdominal surgeries between groups. Group A had a lower incidence of rectal cancer and anterior resections than group B (6.6 vs. 17.7 % [p = 0.006] and 14.3 vs. 23.4 % [p = 0.048]), respectively, and a lower mean operative time (170 min vs. 192 min; p = 0.002). Group A had a lower overall morbidity rate than group B (5.5 vs. 16.9 %; p = 0.004) and a lower incidence of surgery-related complications (5.5 vs. 14.9 %; p = 0.001). The overall conversion rate was 10 % (only one patient in group A required conversion), and the difference in conversion rate between groups was statistically significant (1.2 vs. 10.7 %; p = 0.003). Group A had a lower readmission rate (0 vs. 4.9 %; p = 0.089). Multivariate analysis showed that conversion, postoperative morbidity, and rectal prolapse were independently associated with the length of hospital stay. CONCLUSIONS: A two-day hospital stay after LCR is safe and feasible under an ERAS pathway, without compromising the readmission or complication rate.

Resección total de mesorrecto robótica por cáncer de recto. / [Robotic total mesorectal excision for rectal cancer].

Laparoscopic total mesorectal excision (TME) has proven to be feasible and safe. However, it represents a major technical challenge, since it involves the dissection of the rectum in a confined space such as the bony pelvis using un-ergonomic surgical devices. This difficulty is accentuated in patients with distal tumors and high body mass index (BMI), in which the surgical margins and the hypogastric nerves may be affected. Therefore, robotic surgery aims to overcome these limitations that conspire against the mininvasive surgical approach of rectal cancer. We present an obese (BMI = 32 kg/m2) 82-year-old man with a history of smoking and prostate cancer that was recently diagnosed with a middle rectal adenocarcinoma at 9 cm from the anal verge. Rectal examination evidenced a mobile lesion. Computed tomography scan ruled out metastases and at the local staging by MRI, the tumor was considered as T3-N0 with free circumferential margins. Surgical treatment was decided and a hybrid technique was used combining an initial laparoscopic approach followed by the robotic TME. The patient had a full recovery and was discharged three days after surgery without complications. Pathological examination revealed a low-grade adenocarcinoma with mesorectal invasion, free circumferential and distal margins, and 24 negative lymph nodes (pT3-pN0-pM0/Stage II). Robotic TME was performed safely in an obese patient. It facilitated dissection maneuvers in a confined space with proper identification and preservation of the hypogastric nerves, allowing retrieving an intact mesorectum. Prospective randomized trials will define the role of this new technology.