Brazilian single-center experience with aortic root replacement in 448 patients: what is the best technique?

Abstract Introduction: The objective of this study was to evaluate whether a surgery with the use of valved conduit is capable of leading to better immediate and late results than those obtained by the valve-sparing aortic root reconstruction technique. Methods: Between January 2002 and June 2016, 448 patients underwent aortic root reconstruction. These were divided into three groups according to the technique used: 319 (71.2%) patients received mechanical valved conduits, 49 (10.9%) received biological valved conduits, and 80 (17.9%) underwent the valve-sparing aortic root reconstruction technique. The results were examined by univariate and multivariate analyses of Cox proportional hazards models with multiple logistic regression. Results: The hospital mortality rate was 7.5%. The mortality rates were 8.2%, 12%, and 2.5% in the mechanical valved conduit, biological valved conduit, and aortic valve-sparing groups, respectively, with no significant difference between groups (P=0.1). Thromboembolic complications and reoperation-free survival were also similar (P=0.169 and P=0.688). However, valve-sparing aortic root replacement was superior in terms of long-term survival (P<0.001), hemorrhagic-free survival (P<0.001), and endocarditis-free survival (P=0.048). Multivariate analysis showed that the following aspects had an impact on mortality: age > 70 years (P<0.001; hazard ratio [HR] 1.05), preoperative acute kidney injury (P<0.0042; HR 2.9), diagnosis of dissection (P<0.01; HR 2.0), previous cardiac surgery (P<0.027; HR 2.3), associated coronary artery bypass grafting (P<0.038; HR 1.8), reoperation for postoperative tamponade (P<0.004; HR 2.2) and postoperative acute kidney injury (P<0.02; HR 3.35). Conclusion: Valve-sparing technique seems to be the operation of choice, whenever possible, for aortic root reconstruction.

Brazilian Single-Center Experience with Aortic Root Replacement in 448 Patients: What Is the Best Technique?

INTRODUCTION: The objective of this study was to evaluate whether a surgery with the use of valved conduit is capable of leading to better immediate and late results than those obtained by the valve-sparing aortic root reconstruction technique. METHODS: Between January 2002 and June 2016, 448 patients underwent aortic root reconstruction. These were divided into three groups according to the technique used: 319 (71.2%) patients received mechanical valved conduits, 49 (10.9%) received biological valved conduits, and 80 (17.9%) underwent the valve-sparing aortic root reconstruction technique. The results were examined by univariate and multivariate analyses of Cox proportional hazards models with multiple logistic regression. RESULTS: The hospital mortality rate was 7.5%. The mortality rates were 8.2%, 12%, and 2.5% in the mechanical valved conduit, biological valved conduit, and aortic valve-sparing groups, respectively, with no significant difference between groups (P=0.1). Thromboembolic complications and reoperationfree survival were also similar (P=0.169 and P=0.688). However, valve-sparing aortic root replacement was superior in terms of long-term survival (P<0.001), hemorrhagic-free survival (P<0.001), and endocarditis-free survival (P=0.048). Multivariate analysis showed that the following aspects had an impact on mortality: age > 70 years (P<0.001; hazard ratio [HR] 1.05), preoperative acute kidney injury (P<0.0042; HR 2.9), diagnosis of dissection (P<0.01; HR 2.0), previous cardiac surgery (P<0.027; HR 2.3), associated coronary artery bypass grafting (P<0.038; HR 1.8), reoperation for postoperative tamponade (P<0.004; HR 2.2) and postoperative acute kidney injury (P<0.02; HR 3.35). CONCLUSION: Valve-sparing technique seems to be the operation of choice, whenever possible, for aortic root reconstruction.

The learning curve effect on outcomes with frozen elephant trunk technique for extensive thoracic aorta disease.

OBJECTIVE: The purpose of this study was to analyze the learning curve effect on hospital mortality, postoperative outcomes, freedom from reintervention in the aorta and long-term survival after frozen elephant trunk (FET) operation. METHODS: From July 2009 to June 2018, 79 patients underwent surgery with the FET technique. They had type A aortic dissection (acute 7.6%, chronic 33%), type B aortic dissection (acute 1.26%, chronic 34.2%), and complex thoracic aortic aneurysm (24%). 27.8% were reoperations and 43% received concomitant cardiac procedures. To compare the results, the sample was divided into group 1 (G1) (first half of the sample - operations from 2009 to 2014) and group 2 (G2) (first half of the sample - operations from 2015 to 2018). RESULTS: The in-hospital mortality was 20.25%, 30.7% for G1 and 10% for G2 (P = .02). The mean cardiopulmonary bypass time, myocardial ischemia time, and selective cerebral perfusion at 25°C time were 154 ± 31, 118 ± 32, and 59 ± 12 minutes, respectively, similar for both groups. Stroke and spinal cord injury occurred in four and two patients, with no difference between groups (P = .61 and P = .24). The necessity for secondary intervention on the downstream aorta for both groups was also similar (P = .136). Five of sixty-three surviving patients died during the follow-up period and the estimated survival rate was different between groups 49% vs 88% (P = .007). CONCLUSION: The learning curve with the FET procedure had a significant impact on hospital mortality and midterm survival over the follow-up period, albeit did not influence the freedom from reintervention on the downstream aorta.

Hybrid Approach of Aortic Diseases: Zone 1 Delivery and Volumetric Analysis on the Descending Aorta.

INTRODUCTION: Conventional techniques of surgical correction of arch and descending aortic diseases remains as high-risk procedures. Endovascular treatments of abdominal and descending thoracic aorta have lower surgical risk. Evolution of both techniques - open debranching of the arch and endovascular approach of the descending aorta - may extend a less invasive endovascular treatment for a more extensive disease with necessity of proximal landing zone in the arch. OBJECTIVE: To evaluate descending thoracic aortic remodeling by means of volumetric analysis after hybrid approach of aortic arch debranching and stenting the descending aorta. METHODS: Retrospective review of seven consecutive patients treated between September 2014 and August 2016 for diseases of proximal descending aorta (aneurysms and dissections) by hybrid approach to deliver the endograft at zone 1. Computed tomography angiography were analyzed using a specific software to calculate descending thoracic aorta volumes pre- and postoperatively. RESULTS: Follow-up was done in 100% of patients with a median time of 321 days (range, 41-625 days). No deaths or permanent neurological complications were observed. There were no endoleaks or stent migrations. Freedom from reintervention was 100% at 300 days and 66% at 600 days. Median volume reduction was of 45.5 cm3, representing a median volume shrinkage by 9.3%. CONCLUSION: Hybrid approach of arch and descending thoracic aorta diseases is feasible and leads to a favorable aortic remodeling with significant volume reduction.

Hybrid approach of aortic diseases: zone 1 delivery and volumetric analysis on the descending aorta

Abstract Introduction: Conventional techniques of surgical correction of arch and descending aortic diseases remains as high-risk procedures. Endovascular treatments of abdominal and descending thoracic aorta have lower surgical risk. Evolution of both techniques - open debranching of the arch and endovascular approach of the descending aorta - may extend a less invasive endovascular treatment for a more extensive disease with necessity of proximal landing zone in the arch. Objective: To evaluate descending thoracic aortic remodeling by means of volumetric analysis after hybrid approach of aortic arch debranching and stenting the descending aorta. Methods: Retrospective review of seven consecutive patients treated between September 2014 and August 2016 for diseases of proximal descending aorta (aneurysms and dissections) by hybrid approach to deliver the endograft at zone 1. Computed tomography angiography were analyzed using a specific software to calculate descending thoracic aorta volumes pre- and postoperatively. Results: Follow-up was done in 100% of patients with a median time of 321 days (range, 41-625 days). No deaths or permanent neurological complications were observed. There were no endoleaks or stent migrations. Freedom from reintervention was 100% at 300 days and 66% at 600 days. Median volume reduction was of 45.5 cm3, representing a median volume shrinkage by 9.3%. Conclusion: Hybrid approach of arch and descending thoracic aorta diseases is feasible and leads to a favorable aortic remodeling with significant volume reduction.

Does aortic valve repair in valve-sparing aortic root reconstruction compromise the longevity of the procedure?

OBJECTIVES:: The effect of performing aortic valve repair in combination with valve-sparing operation on the length of time for which patients are free from reoperation is unclear. The objective of this study was to determine if the performance of aortic valve repair during valve-sparing operation modified the freedom from reoperation time. METHODS:: From January 2003 to July 2014, 78 patients with a mean age of 49±15 years underwent valve-sparing operation. Sixty-eight percent of these patients were male. Twenty-two (28%) aortic valve repair procedures were performed in this patient population. In the aortic valve repair + valve-sparing operation group, 77.3% of patients had moderate/severe aortic insufficiency, while in the valve-sparing operation group, 58.6% of patients had moderate/severe aortic insufficiency (ns = not significant). Additionally, 13.6% of patients in the aortic valve repair + valve-sparing operation group had functional class III/IV, while 14.2% of patients in the valve-sparing operation group had functional class III/IV (ns). RESULTS:: The in-hospital and late mortality rates, for the aortic valve repair + valve-sparing operation and valve-sparing operation groups were similar, as they were 4.5% and 3.6%; and 0% and 1.8%, respectively. In the aortic valve repair + valve-sparing operation group, 0% of patients presented moderate/severe aortic insufficiency during late follow-up, while in the valve-sparing operation group, 14.2% of patients presented with moderate/severe aortic insufficiency during this period (ns). In the aortic valve repair + valve-sparing operation group, 5.3% of patients presented with functional class III/IV, while in the valve-sparing operation group, 4.2% of patients presented with functional class III/IV (ns). In the aortic valve repair + valve-sparing operation group, 0% of patients required reoperation, while in the valve-sparing operation group, 3.6% of patients required reoperation over a mean follow-up period of 1621±1156 days (75 patients). CONCLUSION:: Valve-sparing operation is a safe and long-lasting procedure and performance of aortic valve repair when necessary does not increase risk of reoperation on the aortic valve.

Does aortic valve repair in valve-sparing aortic root reconstruction compromise the longevity of the procedure?

OBJECTIVES: The effect of performing aortic valve repair in combination with valve-sparing operation on the length of time for which patients are free from reoperation is unclear. The objective of this study was to determine if the performance of aortic valve repair during valve-sparing operation modified the freedom from reoperation time. METHODS: From January 2003 to July 2014, 78 patients with a mean age of 49±15 years underwent valve-sparing operation. Sixty-eight percent of these patients were male. Twenty-two (28%) aortic valve repair procedures were performed in this patient population. In the aortic valve repair + valve-sparing operation group, 77.3% of patients had moderate/severe aortic insufficiency, while in the valve-sparing operation group, 58.6% of patients had moderate/severe aortic insufficiency (ns = not significant). Additionally, 13.6% of patients in the aortic valve repair + valve-sparing operation group had functional class III/IV, while 14.2% of patients in the valve-sparing operation group had functional class III/IV (ns). RESULTS: The in-hospital and late mortality rates, for the aortic valve repair + valve-sparing operation and valve-sparing operation groups were similar, as they were 4.5% and 3.6%; and 0% and 1.8%, respectively. In the aortic valve repair + valve-sparing operation group, 0% of patients presented moderate/severe aortic insufficiency during late follow-up, while in the valve-sparing operation group, 14.2% of patients presented with moderate/severe aortic insufficiency during this period (ns). In the aortic valve repair + valve-sparing operation group, 5.3% of patients presented with functional class III/IV, while in the valve-sparing operation group, 4.2% of patients presented with functional class III/IV (ns). In the aortic valve repair + valve-sparing operation group, 0% of patients required reoperation, while in the valve-sparing operation group, 3.6% of patients required reoperation over a mean follow-up period of 1621±1156 days (75 patients). CONCLUSION: Valve-sparing operation is a safe and long-lasting procedure and performance of aortic valve repair when necessary does not increase risk of reoperation on the aortic valve.

Surgery of the aortic root: should we go for the valve-sparing root reconstruction or the composite graft-valve replacement is still the first choice of treatment for these patients? / Cirurgia da raiz da aorta: deve-se preservar a valva aórtica ou a operação com o tubo valvulado ainda é a primeira opção de tratamento para esses pacientes?

AbstractObjective:To compare the results of the root reconstruction with the aortic valve-sparing operation versus composite graftvalve replacement.Methods:From January 2002 to October 2013, 324 patients underwent aortic root reconstruction. They were 263 composite graft-valve replacement and 61 aortic valve-sparing operation (43 reimplantation and 18 remodeling). Twenty-six percent of the patients were NYHA functional class III and IV; 9.6% had Marfan syndrome, and 12% had bicuspid aortic valve. There was a predominance of aneurysms over dissections (81% vs. 19%), with 7% being acute dissections. The complete follow-up of 100% of the patients was performed with median follow-up time of 902 days for patients undergoing composite graft-valve replacement and 1492 for those undergoing aortic valve-sparing operation.Results:In-hospital mortality was 6.7% and 4.9%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). During the late follow-up period, there was 0% moderate and 15.4% severe aortic regurgitation, and NYHA functional class I and II were 89.4% and 94%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). Root reconstruction with aortic valve-sparing operation showed lower late mortality (P=0.001) and lower bleeding complications (P=0.006). There was no difference for thromboembolism, endocarditis, and need of reoperation.Conclusion:The aortic root reconstruction with preservation of the valve should be the operation being performed for presenting lower late mortality and survival free of bleeding events.

ResumoObjetivo:Analisar comparativamente os resultados da operação de preservação da valva aórtica e do tubo valvulado nas reconstruções da raiz da aorta.Métodos:No período de janeiro de 2002 a outubro de 2013, 324 pacientes foram submetidos à reconstrução da raiz da aorta. Foram 263 tubos valvulados e 61 preservações da valva aórtica (43 reimplantes e 18 remodelamentos). 26% dos pacientes estavam em classe funcional III e IV; 9,6% com síndrome de Marfan e 12% apresentavam valva aórtica bivalvulada. Houve predomínio dos aneurismas sobre as dissecções (81% contra 19%), sendo 7% de dissecções agudas. O seguimento completo de 100% dos pacientes foi realizado com tempo mediano de seguimento de 902 dias para pacientes submetidos à tubo valvulado e de 1492 para aqueles submetidos à preservação da valva aórtica.Resultados:A mortalidade hospitalar foi de 6,7% contra 4,9% respectivamente para tubo valvulado e preservação da valva aórtica (ns). No seguimento tardio, a insuficiência aórtica importante foi de 0% e 5,8%, e a insuficiência cardíaca crônica, classe funcional I e II de 89,4% e 94%, respectivamente, para tubo valvulado e preservação da valva aórtica (ns). A reconstrução da raiz da aorta com a preservação da valva aórtica apresentou menor mortalidade tardia (P=0,001) e menos complicações hemorrágicas (P=0,006). Não houve diferença para tromboembolismo, endocardite ou necessidade de reoperação.Conclusão:A reconstrução da raiz da aorta com a preservação valvar deve ser a operação a ser realizada por apresentar menor mortalidade e sobrevida livre de eventos hemorrágicos.

Surgery of the aortic root: should we go for the valve-sparing root reconstruction or the composite graft-valve replacement is still the first choice of treatment for these patients?

OBJECTIVE: To compare the results of the root reconstruction with the aortic valve-sparing operation versus composite graft-valve replacement. METHODS: From January 2002 to October 2013, 324 patients underwent aortic root reconstruction. They were 263 composite graft-valve replacement and 61 aortic valve-sparing operation (43 reimplantation and 18 remodeling). Twenty-six percent of the patients were NYHA functional class III and IV; 9.6% had Marfan syndrome, and 12% had bicuspid aortic valve. There was a predominance of aneurysms over dissections (81% vs. 19%), with 7% being acute dissections. The complete follow-up of 100% of the patients was performed with median follow-up time of 902 days for patients undergoing composite graft-valve replacement and 1492 for those undergoing aortic valve-sparing operation. RESULTS: In-hospital mortality was 6.7% and 4.9%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). During the late follow-up period, there was 0% moderate and 15.4% severe aortic regurgitation, and NYHA functional class I and II were 89.4% and 94%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). Root reconstruction with aortic valve-sparing operation showed lower late mortality (P=0.001) and lower bleeding complications (P=0.006). There was no difference for thromboembolism, endocarditis, and need of reoperation. CONCLUSION: The aortic root reconstruction with preservation of the valve should be the operation being performed for presenting lower late mortality and survival free of bleeding events.

Surgical treatment of complex aneurysms and thoracic aortic dissections with the Frozen Elephant Trunk technique.

OBJECTIVE: Report initial experience with the Frozen Elephant Trunk technique. METHODS: From July 2009 to October 2013, Frozen Elephant Trunk technique was performed in 21 patients (66% male, mean age 56 ± 11 years). They had type A aortic dissection (acute 9.6%, chronic 57.3%), type B (14.3%, all chronic) and complex aneurysms (19%). It was 9.5% of reoperations and 38% of associated procedures (25.3% miocardial revascularization, 25.3% replacement of aortic valve and 49.4% aortic valved graft). Aortic remodeling was evaluated comparing preoperative and most recent computed tomography scans. One hundred per cent of complete follow-up, mean time of 28 months. RESULTS: In-hospital mortality of 14.2%, being 50% in acute type A aortic dissection, 8.3% in chronic type A aortic dissection, 33.3% in chronic type B aortic dissection and 0% in complex aneurysms. Mean times of cardiopulmonary bypass (152 ± 24 min), myocardial ischemia (115 ± 31 min) and selective cerebral perfusion (60 ± 15 min). Main complications were bleeding (14.2%), spinal cord injury (9.5%), stroke (4.7%), prolonged mechanical ventilation (4.7%) and acute renal failure (4.7%). The need for second-stage operation was 19%. False-lumen thrombosis was obtained in 80%. CONCLUSION: Frozen Elephant Trunk is a feasible technique and should be considered. The severity of the underlying disease justifies high mortality rates. The learning curve is a reality. This approach allows treatment of more than two segments at once. Nonetheless, if a second stage is made necessary, it is facilitated.

Surgical treatment of complex aneurysms and thoracic aortic dissections with the Frozen Elephant Trunk technique / Tratamento cirúrgico dos aneurismas complexos e dissecções da aorta torácica utilizando a técnica "Frozen Elephant Trunk"

Abstract Objective: Report initial experience with the Frozen Elephant Trunk technique. Methods: From July 2009 to October 2013, Frozen Elephant Trunk technique was performed in 21 patients (66% male, mean age 56 ±11 years). They had type A aortic dissection (acute 9.6%, chronic 57.3%), type B (14.3%, all chronic) and complex aneurysms (19%). It was 9.5% of reoperations and 38% of associated procedures (25.3% miocardial revascularization, 25.3% replacement of aortic valve and 49.4% aortic valved graft). Aortic remodeling was evaluated comparing preoperative and most recent computed tomography scans. One hundred per cent of complete follow-up, mean time of 28 months. Results: In-hospital mortality of 14.2%, being 50% in acute type A aortic dissection, 8.3% in chronic type A aortic dissection, 33.3% in chronic type B aortic dissection and 0% in complex aneurysms. Mean times of cardiopulmonary bypass (152±24min), myocardial ischemia (115±31min) and selective cerebral perfusion (60±15min). Main complications were bleeding (14.2%), spinal cord injury (9.5%), stroke (4.7%), prolonged mechanical ventilation (4.7%) and acute renal failure (4.7%). The need for second-stage operation was 19%. False-lumen thrombosis was obtained in 80%. Conclusion: Frozen Elephant Trunk is a feasible technique and should be considered. The severity of the underlying disease justifies high mortality rates. The learning curve is a reality. This approach allows treatment of more than two segments at once. Nonetheless, if a second stage is made necessary, it is facilitated. .

Resumo Objetivo: Relatar experiência inicial com a técnica "Frozen Elephant Trunk". Métodos: Entre julho de 2009 e outubro de 2013, 21 pacientes, 66% homens, média de idade de 56±11 anos, 66,7% portadores de dissecção da aorta tipo A de Stanford (9,6% agudas e 57,1% crônicas), tipo B (14,3%, todas crônicas) e aneurismas complexos (19%), foram operados pela técnica Frozen Elephant Trunk. Foram 9,5% de reoperações e 38% com procedimentos associados (25,3% revascularizações do miocárdio, 25,3% troca da valva aórtica e 49,4% tubos valvulados). Remodelamento da aorta foi avaliado com a comparação de angiotomografia pré-operatória e pós-operatória mais recente. Seguimento 100% dos pacientes, tempo médio de 28 meses. Resultados: Mortalidade hospitalar de 14,2%, sendo 50% nas dissecções do tipo A agudas, 8,3% nas tipo A crônicas, 33,3% nas tipo B crônicas e 0% nos aneurismas complexos. Tempos médios de CEC (152±24min), isquemia miocárdica (115±31min) e perfusão cerebral seletiva (60±15min). Principais complicações pós-operatórias foram sangramento (14,2%), acidente vascular encefálico (4,7%), paraplegia (9,5%), intubação>72h (4,7%) e insuficiência renal aguda (4,7%). Houve necessidade de complementação do tratamento (distal ao stent) em 19%. Houve trombose da falsa luz em 80%. Conclusão: Frozen Elephant Trunk é opção técnica a ser utilizada. A gravidade e extensão da doença justificam mortalidade mais elevada. A curva de aprendizado é uma realidade. Esta abordagem permite abordar mais de dois segmentos de aorta em um estágio, mas se necessário segundo estágio, este é facilitado. .

Streptococcus pneumoniae aislados durante 2002-2006: serotipos y resistencia antibiótica. Correlación con las vacunas existentes / Streptococcus pneumoniae isolated during 2002-2006: serotypes and antibiotics resistance. Correlation with existing vaccines

Objetivos: Identificar los serotipos de S. pneumoniae aislados, correlacionándolos con los incluidos en las vacunas existentes y su resistencia antimicrobiana. Diseño: Estudio descriptivo, observacional y longitudinal. Lugar: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM. Material biológico: Cepas de Streptococcus pneumoniae. Intervenciones: Cuarenta Streptococcus pneumoniae de nuestro cepario, aislados entre el 2002 y 2006, fueron serotipificados en el Instituto de Salud Carlos III en Madrid ûEspaña; 15 fueron invasivos, 11 aislados de infecciones localizadas, 6 de portadores y 8 eran multiresistentes. Principales medidas de resultados: Protección de las vacunas existentes en nuestro medio a las infecciones causadas por Streptococcus pneumoniae. Resultados: Hubo 14 serotipos diferentes y los serogrupos más identificados fueron 23, 19 y 6. El 28,6 por ciento estaba contenido en la vacuna 7ûvalente, 42,9 por ciento en la 9ûvalente, 50 por ciento en la 11ûvalente y el 71,4 por ciento en la 23ûvalente; 57,5 por ciento fue resistente a la penicilina y 30 por ciento a eritromicina. El grupo de Streptococcus invasivo resultó más sensible a los antibióticos que los otros grupos. Los serotipos asociados a multirresistencia fueron 19F y 23F. Conclusiones: Ninguna de las vacunas protege a todas las infecciones causadas por Streptococcus pneumoniae, en nuestro medio.

Objectives: To identify isolated S. pneumoniae serotypes correlating them with those covered by existing vaccines and determining antimicrobial resistance. Design: Descriptive, observational and longitudinal study. Setting: Daniel A Carrion Tropical Medicine Institute, School of Medicine, UNMSM. Biologic material: Streptococcus pneumoniae stocks. Interventions: Forty Streptococcus pneumoniae stocks isolated between 2002 and 2006 were serotyped at Carlos III Health Institute in Madrid, Spain; 15 were invasive, 11 isolated from localized infections, 6 from carriers and 8 were multiresistant. Main outcome measures: Protection of local existing vaccines to Streptococcus pneumoniae infections. Results: There were 14 different serotypes and most identified groups were 23, 19 and 6, 28,6 per centcontained in the 7ûvalent vaccine, 42,9 per cent in the 9-valent, 50 per cent in the 11-valent and 71,4 per cent in the 23-valent; 57,5 per cent were resistant to penicillin and 30 per cent to erythromycin. The invasive Streptococcus group proved to be more sensitive to antibiotics than the other groups; 19F and 23F serotypeswere multiresistant. Conclusions: In our environment none of the studied vaccines protected all the infections caused by Streptococcus pneumoniae. Resistance to penicillin was high.

Susceptibilidad in vitro de Streptococcus pneumoniae y Moraxella catarrhalis a 5 antimicrobianos orales / In vitro susceptibility of Streptococcus pneumoniae and Moraxella catarrhalis five (5) oral antimicrobial

Streptococcus pneumoniae y Moraxella catarrhalis son dos de los patógenos que causan con mayor frecuencia infección respiratoria aguda. Cincuenta cepas de Streptococcus pneumoniae aisladas el año 2002, 50 aisladas el 2003, 50 cepas de Moraxella catarrhalis aisladas el 2002 y 31 el 2003 fueron descongeladas para hacerles el antibiograma por el método de disco difusión a los siguientes antibióticos: amoxicilina/ácido clavulánico, cefuroxima, cefaclor, claritromicina y penicilina o ampicilina según la bacteria. Todas las cepas aisladas el 2002 y 2003 fueron sensibles a amoxicilina/ácido clavulánico. El año 2003 aumentó el porcentaje de cepas, de ambas bacterias, sensibles a cefuroxima. El año 2003 disminuyó la resistencia de ambas bacterias, al cefaclor. El año 2003 aumentó la resistencia del Neumococo a Claritromicina, mientras que Moraxella catarrhalis disminuyó. El año 2003 disminuyó la resistencia del Neumococo a la penicilina y también dismuinuyó la resistencia de M. catarrhalis a la ampicilina. En conclusión amoxicilina/ácido clavulánico sería de elección para el tratamiento empírico de las infecciones respiratorias altas, sobre todo en niños, y es recomendable vigilar anualmente la resistenciaa los antimicrobianos de las bacterias causantes de infección respiratoria aguda en la comunidad.

Susceptibilidad a antimicrobianos de patógenos respiratorios en niños provenientes de la comunidad / Respiratory pathogenic microorganism's sensitivity in community children

Objetivo: Determinar la resistencia de los patógenos respiratorios a diferentes antimicrobianos. Material y métodos: Entre abril y noviembre de 2002 se estudió 177 pacientes que asistieron al consultorio externo de otorrinolaringología del Hospital Nacional Docente Madre Niño San Bartolomé. Resultados: Streptococcus pneumoniae fue la bacteria patógena más aislada (57,2 por ciento), luego Moraxella catarrhalis (42,7 por ciento), Staphylococcus aureus (18,6 por ciento) y en pequeña cantidad Haemophilus influenzae (3,4 por ciento) y Streptococcus pyogenes (0,7 por ciento). Streptococcus pneumoniae presentó 31,3 por ciento de resistencia a la penicilina. El 96,7 por ciento de Moraxella catarrhalis fueron productoras de betalactamasa y 7,4 por ciento de los Staphylococcus aureus fueron resistentes a la oxacilina. Conclusión: Streptococcus pneumoniae es el principal agente causal de los procesos infecciosos altos en niños y su resistencia a la penicilina aumentó a 31,3 por ciento.

Objective: To determine the respiratory pathogens resistance to different antimicrobial drugs. Material and methods: From April through November 2002, 177 patients attending the Mother-Child National Teaching Hospital Otorhinolaryngology outpatientÆs office were studied. Results: Streptococcus pneumoniae was the most frequently isolated pathogenic bacteria (57,2 per cent), followed by Moraxella catarrhalis (42,7 per cent), Staphylococcus aureus (18,6 per cent), Haemophilus influenzae (3,4 per cent) and Streptococcus pyogenes (0,7 per cent). Streptococcus pneumoniae showed resistance to the penicillin in 31,3 per cent; 96,7 of Moraxella catarrhalis were producers of betalactamase and 7,4 per cent of Staphylococcus aureus showed resistance to oxacillin. Conclusion: Streptococcus pneumoniae is the principal causal factor of respiratory infections in children and its resistance to the penicillin increased to 31,3 per cent.

Aeromonas en la diarrea aguda de niños menores de 5 años / Aeromonas in children less than 5 year-old with acute diarrhea

Objetivo: Determinar la importancia de Aeromonas como agente diarreogénico en niños menores de 5 años, así como comparar su frecuencia con la de otros enteropatógenos. Material y Métodos: Entre 1998 y 1999, se tomó 285 muestras de heces de niños con diarrea aguda, en 5 Centros Hospitalarios, las que fueron enviadas al Instituto de Medicina Tropical ."Daniel A. Carrión." en el medio de transporte Cary Blair, para su procesamiento e identificación de Aeromonas por el método Aerokey II. Resultados: Aeromonas fue la bacteria más aislada entre los enteropatógenos, sobre todo en niños menores de 2 años y en verano, y la Aeromonas caviae fue la especie más frecuente. Aeromonas fue aislada en la mayoría de los casos del agar TCBS, por lo que empleamos discos de O/129 para diferenciarla de Vibrio cholerae. Todas las Aeromonas fueron sensibles in vitro a furazolidona y neomicina. Conclusiones: Aeromonas fue el principal agente etiológico de la diarrea aguda acuosa, en niños menores de 5 años.

Significado clínico de la presencia de Enterococcus en Secreción vaginal / Clinical significance of Enterococcus presence vaginal discharge

Objetivos: Determinar si la presencia de Enterococcus se asocia a flujo vaginal patológico, su frecuencia en éste y los niveles de resistencia a antimicrobianos. Material y métodos: En un período de 4 meses se selecciono 98 pacientes que acudieron a consulta externa ginecológica con flujo vaginal, en las cuales se buscó tanto la presencia de leucocitos como aislamiento para enterococcus y otros microorganismos. Resultados: en el 39 por ciento de los pacientes se aisló Enterococcus principalmente E. faecalis. Gardnerella vaginal fue identificada en el 44 por ciento de las pacientes. No se encontró relación entre la presencia de Enterococcus y signos de patogenecidad, ni con relaciones sexuales contranatura. No hubo enterococcus resistente a la penicilina. Conclusiones: Enterococcus no ejercería acción patógena en las pacientes estudiadas, aún cuando ocupó el segundo lugar en frecuencia entre las pacientes con flujo vaginal, luego de Gardnerella vaginalis. No hubo resistencia in vitro a la penicilina en las 38 cepas estudiadas

Resistencia in vitro del Vibrio cholerae O1 a seis antimicrobianos / In vitro resistance of Vibrio cholerae O1 to six anticrobials

Se estudio la resistencia in vitro por el método de disco-difusión a 332 cepas de V. cholerae aislados en 151 adultos del Hospital Dos de Mayo de Lima, 146 de niños y 35 adultos del Hospital Carrión del Callao. Se obtuvo una resistencia promedio total del 8.4 por ciento a la ampicilina, 5.4 por ciento a la doxiciclina, 3.3 por ciento a la tetraciclina, 3 por ciento al cotrimoxazol, 0.6 por ciento a la furazolidona y ninguna a norfloxacina. No se justifica por el momento en cambio en el tratamiento antimicrobiano del cólera, que se realiza con tetraciclina o cotrimoxazol, y se tiene como alternativa en casos particulares de resistencia a la furazolidona y la fluoquinolonas

Resistencia in vitro de Shigellas de Lima Metropolitana / In vitro Shigella resistance in Lima Metropolitana

Del 15 de noviembre de 1989 al 15 de enero de 1991 (14 meses) recolectamos 214 cepas de Shigella de 8 Laboratorios de Lima Metropolitana, predominando S. flexneri con el 61.7 por ciento. Aplicando el método de disco-difusión estandarizado para el antibiograma, se utilizaron discos de amikacina, ampicilina, cloranfenicol, ácido nalidíxico, norfloxacina, sulfadiazina, cotrimoxazol y tetraciclina. Encontramos resistencia a tetraciclina, 90.7 por ciento; ampicilina, 89.7 por ciento; cloranfenicol, 79.4 por ciento; sulfadiazina, 73.8 por ciento; cotrimoxazol, 34.1 por ciento; amikacina, 7.9 por ciento ácido nalidíxico, 0 por ciento y norfloxacina, 0 por ciento. El 89.7 por ciento de las cepas de Shigella fueron resistentes a 2 o más antimicrobianos. El patrón de resistencia más identificado fue a 5 de los antimicrobianos: AM: C, SD, STX, TE con la prevalencia de 26.5 por ciento. Todas las S. sonnei y S. boydii presentaron algún tipo de resistencia, mientras que S. dysenteriae el 94.1 por ciento y S. flexneri el 97 por ciento. La resistencia de Shigella aisladas en Lima ha sido en aumento en los últimos años, manteniéndose sensibles a las quinolonas, las cuales podrían ser el tratamiento de elección. Se enfatiza como medida preventiva lavarse las manos después de ir al baño y antes de manipular alimentos.

Two hundred and fourteen Shigella strains were isolated from patiens in eight laboratories in Metropolitan Lima from 15 November 1989 to 15 January 1991(14 months). S. flexneri was the predominant strain with 61. 7 per cent. Amikacin, ampicillin, chloramphenicol, nalidixic acid, norfloxacin, sulfadiazine, cotrimoxazol and tetracycline discs were used in the standardized disc- diffusion method for the susceptibility test. The strains were found to be resistant to tetracycline, 90.7 per cent; ampicillin, 89.7 per cent; choloramphenicol, 79.4 per cent;sulfadiazine, 73.8 per cent; cotrimaxol, 34.1 per cent; amikacin, 7.9 per cent; nalidixic acid, 0 per cent norfloxazin, 0 per cent. 89.7 per cent of the Shigella strains resistant to two or more antimicrobials.The most often identified resistance pattern was to 5 of the antimicrobials: AM, C, SD, STX, TE with a 26.2 per cent prevalence. All S. sonnei and S. boydii presented some type of resitance, whereas. S. dysenteriae showed 94.1 per cent and S. flexneri 97 per cent. Resistance from Shigella isolated in Lima has increased in the last years, athough they have sensitive to quinolones. Thus, quinolones may be the treatment of choice. Handwashing after and before using the bathroom or manipulating food is strongly enphasized as a preventive measure