Efecto del catéter de hemodiálisis en la permeabilidad de fístulas arteriovenosas / The impact of hemodialysis catheter on arteriovenous fistula permeability

Resumen Objetivo: Evaluar el impacto que tiene el uso de catéteres de hemodiálisis en la permeabilidad de fístulas arteriovenosas. Materiales y Método: Estudio observacional, analítico, tipo cohorte retrospectiva. Se calculó un tamaño muestral de 195 pacientes, seleccionados aleatoriamente a partir del total de pacientes diagnosticados con enfermedad renal crónica (ERC) terminal, a quienes se les realizó su primera fístula arteriovenosa (FAV) entre enero de 2014 y diciembre de 2018. Como variables resultado se consideraron la trombosis de FAV y el tiempo de permeabilidad. Para el análisis inferencial se utilizaron las pruebas de Chi cuadrado; RR (IC 95%); curvas Kaplan-Meier; regresión de Cox; considerando un valor de p significativo < 0,05. Resultados: El 52,3% utilizó catéter de hemodiálisis, de los cuales el 49,5% presentó trombosis de su FAV versus el 17,7% del grupo sin este antecedente (p < 0,001); estimándose en el análisis univariado un riesgo de trombosis 2,7 veces mayor en pacientes con catéter previo a la confección de su FAV (IC 95% 1,7 a 4,4). En el análisis multivariado, se identificó como único factor significativo el antecedente de catéter de hemodiálisis, estimándose que los pacientes usuarios de catéter previo a la confección de su FAV tienen 2,8 veces más riesgo de trombosis en el tiempo que quienes no utilizaron catéter (IC 95% 1,6 a 4,9), quienes además presentaron un tiempo de permeabilidad significativamente menor (p < 0,001) en comparación con pacientes sin antecedente de catéter (28,1 vs 43,9 meses). Conclusión: Identificamos el uso del catéter de hemodiálisis como un factor de riesgo de trombosis de fístulas arteriovenosas, afectando significativamente su permeabilidad en el tiempo.

Objective: To evaluate the effects of hemodialysis catheter on arteriovenous fistula (AVF) permeability. Materials and Method: We conducted a retrospective cohort study, including 195 patients randomly selected from all patients diagnosed with chronic renal failure, who had their first arteriovenous fistula between January 2014 and December 2018. The outcomes were arteriovenous fistula thrombosis and permeability. For data analysis we used Chi-square test; Relative-Risk (CI 95%); Kaplan-Meier analysis and Cox regression; p value less than 0.05 were considered as significant. Results: The 52.3% of the patients used hemodialysis catheter, from this group, the 49.5% had AVF thrombosis versus the 17.7% of the group without history of hemodialysis catheter (p < 0.001), estimating in the univariate analysis a risk of thrombosis 2.7 times higher in patients with catheter before the creation of their AVF (CI 95% 1.7 a 4.4), as well as, in the multivariate analysis the risk of AVF thrombosis was 2.8 times higher in this group of patients, being identified the history of hemodialysis catheter as the only significative risk factor for thrombosis. Additionally, the AVF permeability time in this group was significantly less (p < 0.001) than patients without history of hemodialysis catheter (28.1 vs 43.9 months). Conclusion: We identified the hemodialysis catheter as a risk factor of arteriovenous fistula thrombosis, decreasing significantly its permeability time.

Growth and antioxidant response of juvenile oysters Crassostrea sikamea and Crassostrea corteziensis treated with Streptomyces strains / Crescimento e resposta oxidative de ostras jovens Crassostrea sikamea e Crassostrea corteziensis tratadas com cultura Streptomyces

The effect of three Streptomyces strains (N7, RL8 and V4) and a mixture of Bacillus (BMix) on the growth (Weight, Size) and superoxide dismutase activity (SOD) in hatchery-reared juvenile oysters Crassostrea corteziensis and Crassostrea sikamea was investigated to determine their probiotic potential. Microorganisms were added to culture water at 1×106 CFU/ml once a day during 30 days and all oysters fed daily a microalgae mix. Juveniles of C. sikamea treated with strains N7, RL8 and V4 had a significant weight gain compared to the control group. C. corteziensis juveniles treated with strains RL8 and BMix showed a significantly higher weight gain than the control group. No significant size increase was observed in any treated group for both oyster species. SOD activity significantly increased in C. sikamea treated with RL8 and with RL8, N7 and BMix in C. corteziensis. Streptomyces strains RL8 and N7 emerge as promising probiotic agents to cultivate C. sikamea and C. corteziensis and may also be useful to other molluscs and marine invertebrates .(AU)

O efeito de três culturas Streptomyces (N7, RL8 e V4) e uma mistura de Bacillus (BMix) sobre o cresimento (Peso, Tamanho) e atividade superóxido dismutase (SOD) em ostras jovens Crassostrea corteziensis e Crassostrea sikamea cultivadas artificalmente foi investigado para determinar seu potencial probiótico. Microorganismos foram adicionados à água de cultura a 1×10 6 CFU/ml uma vez por dia durante 30 dias e todas as ostras foram alimentadas diariamente com uma mistura de microalgas. Jovens C. sikamea tratados com culturas N7, RL8 e V4 tiveram ganho de peso significativo quando comparado ao grupo de controle. Jovens C. corteziensis tratados com culturas RL8 e BMix demonstraram peso significativamente mais algo que o grupo de controle. Nenhum aumento em tamanho foi observado em grupos tratados em ambas espécies. A atividade SOD foi significamente aumentada em C. sikamea treatado com RL8 e com RL8, N7 e BMix em C. corteziensis. Culturas Streptomyces RL8 e N7 surgem como agentes probióticos promissores para o cultivo de C. sikamea e C. corteziensis e podem ser úteis para outros moluscos animais marinhos invertebrados.(AU)

Calidad de vida en hemodiálisis y diálisis peritoneal tras cuatro años de tratamiento / Quality of life in hemodialysis and peritoneal dialysis after four years of treatment

Resumen ANTECEDENTES: la hemodiálisis y diálisis peritoneal corrigen algunos síntomas del paciente provocando cambios en el estilo de vida. Hay estudios que demuestran mejor calidad de vida con diálisis peritoneal comparada con hemodiálisis. La escala Kidney Disease Quality of Life (KDQOL SF 36) evalúa adecuadamente la calidad de vida. OBJETIVO: demostrar mayor puntaje en la escala de calidad de vida en pacientes con diálisis peritoneal por más de cuatro años comparados con pacientes en hemodiálisis. MATERIAL Y MÉTODO: estudio observacional, transversal, descriptivo y multicéntrico, realizado del 1 de abril al 31 de mayo de 2016. Se utilizó la escala KDQOL SF 36 en pacientes en diálisis peritoneal o hemodiálisis en el Hospital Central Norte y Regional Poza Rica. Los resultados se compararon con t de Student y χ2. RESULTADOS: se observaron efectos mentales en 39.5% del grupo de diálisis peritoneal vs 47% en hemodiálisis, p 0.05; efectos físicos en 34% de diálisis peritoneal vs 35% en hemodiálisis, p 0.758; carga de la enfermedad renal en 27% en diálisis peritoneal vs 46% en hemodiálisis, p 0.03; efectos de la enfermedad renal en 61% en diálisis peritoneal vs 55% en hemodiálisis, p 0.391; síntomas en 71% en diálisis peritoneal vs 71% en hemodiálisis, p 0.893. CONCLUSIONES: en pacientes con diálisis peritoneal el puntaje es mejor que en pacientes en hemodiálisis en cuanto a efectos de la enfermedad renal. También se observó menor puntaje en pacientes en diálisis peritoneal vs hemodiálisis en carga de la enfermedad renal, área de efectos mentales, efectos físicos y área de síntomas, sin dife rencia estadística. Tampoco hubo diferencia significativa en diálisis a largo plazo (más de cuatro años) entre ambos grupos. Por tanto, el médico y el paciente deben encontrar la modalidad de diálisis que se ajuste mejor a sus necesidades y estilo de vida.

Abstract BACKGROUND: Hemodialysis (HD) and peritoneal dialysis (PD) cor rect some patient symptoms causing changes in the lifestyle. Studies show improved quality of life in PD compared with HD. The scale Kidney Disease Quality of Life (KDQOL SF 36) adequately assesses the quality of life. OBJECTIVE: To show higher scores on the scale of quality of life of patients with peritoneal dialysis (PD) for more than 4 years compared to patients on hemodialysis (HD). MATERIAL AND METHOD: An observational, transversal, descriptive, multicenter study, performed from April 1st to May 31st, 2016. The KDQOL SF 36 scale was used in PD or HD patients in North Central Hospital and Poza Rica Regional Hospital, Mexico. The results were compared with t-Student and χ2. RESULTS: Mental effects in the group of PD 39.5% vs 47% in HD, p 0.05; physical effects on DP 34% vs 35% in HD, p 0.758; burden of kidney disease on PD 27% vs 46% in HD, p 0.03; effects of kidney disease in PD 61% vs 55% in HD, p 0.391; symptoms in PD 71% vs 71% in HD, p 0.893. CONCLUSIONS: Peritoneal dialysis has better score than hemodialysis on effects of kidney disease; PD with lower score that HD in burden of kidney disease, mental effects area; in physical effects, symptoms area with no statistical difference. No significant difference in long-term dialysis (>4 years) between both groups. Therefore, the physician and patient should find dialysis modality that best fits their needs and lifestyle adjustment.

Reparación valvular mitral en insuficiencia mitral degenerativa: reparabilidad, resultados inmediatos y seguimiento hasta 20 años / Mitral valve repair for degenerative mitral insufficiency: likelihood of success, early and-long term results at 20 years

Background: The 2014 Guidelines for the Management of Patients with Valvular Heart Disease require to know the probability of success and operative mortality of Mitral Valve Repair (MVR) for Degenerative Mitral Insufficiency (DMI) at a given institution. Aim: To assess the probability of success, operative mortality and long-term results of MVR for DMI. Patients and Methods: The database of the Cardiovascular Surgery Service was reviewed for the period December 1991 to December 2013. Long-term survival information was obtained from death certificate records of the Chilean Identification Service. Results: One hundred forty seven patients with DMI were identified, all operated by one author (RZ). In 28 (19%) the mitral valve was replaced, including three patients in whom a MVR was intended without success. A successful MVR was performed in 119 patients (81%). The probability of a successful MVR was 97.5% (119 of 122). Prolapsed posterior leaflet was present in 81% and annulus dilatation in 60% of cases. The most frequent surgical procedures were quadrilateral resection (83%) and chordal transfer (13%). A mitral annuloplasty was performed in 92% of cases. Operative mortality was 0.8%. At the end of a 9.9 (0 - 22.7) years follow-up, 87 patients (73%) were alive and mean survival was 16.9 years. Survival rates at 5, 10, 15 and 20 years were 91%, 78%, 71% and 50%, respectively. Six patients were re-operated, due to mitral valve dysfunction in three. Mean re-operation free survival was 21.4 years. Echocardiographic follow-up was 75% completed at an average of 64 months; 84% of cases had no or only 1+ mitral regurgitation. Conclusions: In our experience, MVR for DMI had an operative mortality below 1% and a probability of success greater than 95%, with excellent long-term results.

Resultados a largo plazo de la valvuloplastía mitral con balón / Long term results of mitral balloon valvuloplasty

Background: Mitral balloon valvuloplasty (MBV) is the therapy of choice for the treatment of symptomatic mitral stenosis with suitable anatomy. Although its short and mid-term results are favorable, there is a paucity of information about long-term follow-up. Aim: To assess the late results of MBV. Material and Methods: A cohort of 225 patients aged 8 to 20 years who were subjected to a MBV from 1989 to 2001, was studied. All variables at the time of the procedure, short and long-term results and major events during follow-up (new mitral intervention and mortality) were recorded. Uni and multivariate analysis were used to assess prognosis. Results: The mean follow-up lapse was 13.5 years (range 8 to 20 years). During this period, 88 patients (39.1%) remained event-free and in acceptable functional capacity. Eight percent died, 8% required a second MBV and 43.5% required a surgical mitral valve replacement. A post-procedural area equal or greater to 1.9 cm² was associated with a greater likelihood of free-event survival (log rank test: p = 0.02/Cox proportional regression model: coefficient 0.54, p = 0.04). Conclusions: MBV is effective, although there is a high chance of new interventions in the long-term follow-up. A larger post-procedure mitral area is associated with a better prognosis.

Veinte años de cirugía reparadora de la válvula mitral / Twenty years of mitral valve repair. An experience in 322 patients

Background: Mitral valve repair is the preferred procedure for the surgical treatment of mitral valve insufficiency (MI), procedure that we initiated 20 years ago. Aim: To assess our experience and long-term results of mitral valve repair. Patients and Methods: The database of the cardiology department was reviewed for the period between December 1991 and December 2012. A total of 322 patients aged 18 to 89 years (62% males) undergoing mitral valve repair were identified. Long-term survival information was obtained consulting death certificate records of the Chilean Identification Service. The latest echocardiogram available was analyzed. Results: MI was degenerative in 144 patients (45%) and ischemic in 104 (32%). A prosthetic ring was used in all ischemic and in 92% of non-ischemic MI. Operative mortality was 7.5%, 13% in ischemic and 4.4% in non-ischemic MI (p < 0.01). Overall long-term survival was 14.1 years; 9.3 and 16 years for ischemic and non-ischemic MI, respectively (p < 0.001). Survival at 5, 10, 15 and 20 years was 79, 63, 54 and 42%, respectively. For degenerative MI survival at 5 and 10 years was 90 and 76% and for ischemic MI, it was 64 and 44%, respectively (p < 0.001). On a multivariate analysis the main predictors of late mortality were age, associated valvular disease and ischemic etiology. Echocardiographic follow-up was available for 223 patients; MI was absent in 53% and was mild in 29%. Conclusions: In a 20 years follow-up, mitral valve repair for MI had excellent long-term survival and echocardiographic results. The most common etiologies of MI were degenerative and ischemic diseases. The latter had a worst prognosis. The main predictors of long term mortality were age, associated valvular disease and ischemic etiology.

Resultados alejados de la cirugía reparadora de la insuficiencia mitral isquémica / Long-term results of mitral valve repair for ischemic mitral insufficiency

Background: The preferred treatment for ischemic mitral insufficiency is mitral valve repair with a prosthetic ring, because it does not deteriorate left ventricular function, allowing better immediate and long-term results. Aim: To assess long-term results of mitral annuloplasty with a prosthetic ring for ischemic mitral insufficiency. Patients and Methods: One hundred patients (68 men), with a mean age of 65.7 ± 8.6 years were included. They underwent a mitral annuloplasty with a prosthetic ring to treat ischemic mitral insufficiency, between February 1992 and May 2009. Fortyfour had a history of prior myocardial infarction and 46 had an evolving acute coronary syndrome. The inferior left ventricular wall was involved, exclusively or associated with an adjacent wall, in 72 cases. Coronary artery bypass grafts were performed in 92 patients and 32 required intra-aortic balloon pumping at some time during the peri-operative period. Results: Operative mortality was 10% (10 patients). During follow-up 30 patients died, at an average of 39 months after surgery (range: 3-142 months). Actuarial long-term survival rates at 1, 3 and 5 years were 79%, 72% and 64.5%, respectively. Trans esophageal echocardiogram performed in the operating room showed none or minimal residual mitral insufficiency in 96% of the cases. Echocardiographic follow-up was completed in 80% of the survivors; 79% of them had no or minimal mitral insufficiency. Only one patient was re-operated on due to severe mitral insufficiency and 4 required a permanent pacemaker. Conclusions: Considering the critical illness of these patients, good long-term results were observed after treatment of ischemic mitral regurgitation performing a mitral annuloplasty with a prosthetic ring.

Miocardiopatía no compactada: una serie de 15 casos / Non compaction cardiomyopathy: a series of 15 cases

Background: Non compaction cardiomyopathy is a rare disorder caused by the arrest of myocardial compaction during embryogenesis, leading to a non compacted endocardial layer with marked hypertrabeculation and deep recesses. Aim: To report the clinical and echocardiographic characteristics of a series of 15 adult patients with non-compaction cardiomyopathy. Patients and Methods: We included a total of 15 patients aged 52 ± 17 years (40 percent males) diagnosed at our echocardiography laboratory between January 2001 and July 2010. Results: Theform of presentation was heart failure in 53 percent of subjects, syncope in 20 percento, ventricular arrhythmias in 13 percento and stroke in 7 percent>. Left ventricular end-diastolic diameter was 66 ±11 mm and estimated ejection fraction was 27 ± 10 percent>. Apical and/or mid-ventricular segments of the left ventricle were involved in all the cases. Pulmonary hypertension was present in 40 percento. The average follow-up was 19 months and no patient died during this period. Sixty seven percent ofthe patients had manifestations of heart failure, 27 percento presented sustained ventricular arrhythmias and 20 percent> had atrial fibrillation orflutter, whereas 13 percento had cerebral embolic events. An automated internal cardioverter defibrillator was implanted in 47 percento of patients. Conclusions: Non-compaction cardiomyopathy is associated with high cardiovascular morbidity. The diagnosis is made in advanced stages of the disease, with significant dilation and ventricular dysfunction.

Tratamiento endovascular de la disección aórtica tipo B mediante endoprótesis / Endovascular treatment of type B aortic dissection

Background: Dissections that involve the ascending aorta are classified as type A, regardless of the site of the primary intimal tear, and all other dissections as type B. Type B dissections can have fatal ischemic and hemorrhagic complications. In the chronic state, dilatation and rupture can be mortal. Endovascular surgery is a therapeutic alternative, considering the high rate of complications of conventional surgery Aim: To report the results of endovascular treatment of type B aortic dissection. Material and methods: Report of 36 treated patients (30 males) aged 43 to 87 years, with a type B aortic dissection. Seventy eight percent were hypertensive and 39 percent smoked. The diagnosis was conñrmed by CAT sean. Acute patients were treated for complications and chronic patients, for dilatation. In the operating room, an endoprothesis was placed through the femoral artery, to cover the tear. The tear was located and the lumens were differentiated using angiography and transesophageal echocardiography. Results: All procedures were successful. In 16 acute dissections the indications were malperfusion syndrome or unmanageable hypertension in seven patients and imminent rupture or persistent pain in nine. Twenty chronic patients were operated due to dilatation (mean 6 cm). One patient died due to cardiac failure. One patient had a transient paraparesia and two had pulmonary embolism. No patient died in a follow up períod ranging from 2.5 to 74 months. Four patients required a new aortic endovascular procedure due to progressive dilatation or endoleak. Conclusión: Endovascular treatment of type B aortic dissection has good immediate andlong term results.

Mixoma cardiaco: Caracterización clínica, métodos diagnósticos y resultados alejados del tratamiento quirúrgico durante tres décadas de experiencia / Cardiac myxoma: Clinical characterization, diagnostic methods and late surgical results

Background: Cardiac myxoma is the most common primary cardiac tumor. Aim: To evaluate clinical aspects, diagnostic methods and surgical outcomes in patients with cardiac myxoma. Patients and Methods: AH patients who underwent surgical resection of a cardiac myxoma between January 1973 and December 2004 at our institution, were identified and their medical records and diagnostic data reviewed. Results: Thirty seven patients identified (24 women), with a median age of 54 years (range 2-74). The most common symptom was dyspnea (51 percent), followed by embolism (24 percent) and cardiac murmurs (16 percent). The diagnosis was made by echocardiogram in 84 percent of patients. The mean tumor size was 4.9 ± 1.3 cm. The tumor was located in the ¡eft atrium in 83 percent of the patients, right atrium in 8 percent and ¡eft ventricle in 3 percent. Two patients had multiple tumors. Surgical approach was transeptal in 51 percent, left atriotomy in 22 percent, combined transeptal and roof of the left atrium in 19 percent and right atriotomy in 8 percent. The tumor and its attachment base were excised in one piece. There were two operative deaths and five late deaths. The mean follow-up was 11.5 years. The 5, 10, 15 and 20 years survival was 89 percent, 83 percent, 75 percent and 64 percent, respectively. Two patients had recurrence (5.4 percent), at 2 and 25years after surgery, respectively, and the recurrence free survival at 10 and 25years was 97 percent and 73 percent, respectively. Conclusions: Dyspnea was the most common symptom and echocardiogram the main diagnostic method. Surgical treatment was highly effective, with low mortality and recurrence rate, with good long term survival.

Comportamiento clínico de los tumores cardíacos desde el feto hasta el adulto: serie multicéntrica de 38 pacientes / Cardiac tumors in children and adults: A retrospective study

Background: Cardiac tumors are very uncommon at all ages. There are important clinical differences between children and adults in the behavior of these tumors. Aim: To compare the behavior of primary and secondary cardiac tumors, from fetal age to adults. Patients and Method: Multicentric retrospective analysis of 38 children and adults with cardiac tumors, evaluated with echocardiography between January 1995 and August 2001. Medical records, echocardiographic and radiological examinations, surgical protocols and pathologic examinations were reviewed. Follow-up was obtained through data on medical records or calling patients by telephone. Results: Tumors were diagnosed in 38 patients (13 children and 25 adults), from a total of 31.800 echocardiograms. In children the diagnosis was made by fetal, transthoracic or transesophageal echocardiography in 23.6 percent and 8 percent of cases, respectively. Eighty five percent were primary (10 benign and 1 malignant) and 15 percent, secondary tumors. Fifty four percent were rhabdomyomas and 75 percent regressed spontaneously. Seventy seven percent were symptomatic and 31 percent were treated with surgery. During a follow up of 44±35 months, 31 percent of patients died. In adults, 76 percent of tumors were diagnosed by transthoracic and 20 percent by transesophageal echocardiography. Seventy six percent were primary (18 benign and 1 malignant) and 24 percent secondary tumors. Fifty six percent were myxomas. Ninety two percent were symptomatic and 84 percent were treated surgically. Twenty percent of patients died in the early postoperative period. No adult patients had a follow-up. Conclusions: Rhabdomyomas were solely found in children. In adults, myxomas are the predominat cardiac tumors. Primary and metastasic malignant tumors are observed both in children and in adults.

Reemplazo parcial o total del arco aórtico: Experiencia en 23 pacientes / Partial or total replacement of the aortic arch: Experience in 23 patients

Background: Surgery of the aortic arch is a very complex procedure since it requires protective strategies for the brain, heart and rest of the body. Aim: To communicate our experience in the first 23 total or partial replacements of aortic arch. Material and methods: Retrospective search in the database of the Cardiovascular Surgery Unit for patients subjected to partial or total replacement of the aortic arch since 1998. Results: Between 1988 and 2002, 23 patients were operated. Seventeen had aortic dissection (10 acute and 7 chronic), five had an atherosclerotic aneurysm and one had a traumatic lesion. Thirteen patients were subjected to a replacement of the arch plus ascending aorta, six to a replacement of the arch plus descending aorta and four to a replacement of the arch, ascending and descending aorta. Seven patients had previous operation of the thoracic aorta. Arterial perfusion was done via the femoral artery, axillary artery or a combination of both. A hypothermic circulatory arrest was induced in 22; it was associated with cerebral retro perfusion alone in 8 patients, antegrade cerebral perfusion in 5; isolated or associated axillary perfusion was used in five patients. In seven, procedures on the aortic or mitral valve, or coronary artery operations were added. Operative mortality was 26%, 3 of the 8 patients operated as an emergency and 3 of 15 elective operations. There was no mortality among those without dissection and of 7 chronic dissections, one died. All patients were followed for an average of 45 months. Two patients required reinterventions on the aorta and one for colon cancer. There was one late death of unknown cause. Postoperative complications were agitation, bleeding and temporary vocal cord dysfunction. Conclusions: There is a learning curve, where more extensive operations, particularly those done as emergency or for dissections, had an increased operative risk.

Resultados alejados de la reparación versus reemplazo en insuficiencia mitral degenerativa / Long-term results of repair versus replacement for degenerative mitral valve regurgitation

Background: Mitral valve repair is considered better than mitral valve replacement for degenerative mitral regurgitation. Aim: To evaluate late clinical results of mitral valve repair as compared to mitral valve replacement in patients with degenerative mitral regurgitation. Patients and methods: All patients subjected to open heart surgery for degenerative mitral regurgitation between 1990 and 2002 were assessed for surgical mortality, late cardiac and overall mortality, reoperation, readmission to hospital, functional capacity and anticoagulant therapy. Eighty eight patients (48 males) had mitral valve repair and 28 (19 males) had mitral valve replacement (23 with a mechanical prosthesis). Mean age was 59.9 ± 14.8 (SD) and 61.3 ± 14.6 years, respectively. Sixty three percent of patients with repair and 50% of those with valve replacement were in functional class III or IV before surgery. Results: Operative mortality was 2.3% for mitral valve repair and 3.6% for mitral valve replacement (NS). Also, there was no statistical difference in the need of reoperation during the follow-up period between both procedures (2.3% and 0%, respectively). Ninety four percent of the replacement patients but only 26% of the repair patients were in anticoagulant therapy at the end of the follow-up period (p <0.001). Ten years survival rates were 82 ± 6% for mitral valve repair and 54 ± 11% for replacement. The corresponding cardiac related survival rates were 89 ± 6% and 79 ± 10%. At the end of follow-up, all surviving patients were in functional class I or II. Ten years freedom from cardiac event rates (death, cardiac related rehospitalization and reoperation) were 90 ± 3% for mitral valve repair and 84 ± 6% for replacement. Conclusion: Repair of the mitral valve offers a better overall survival and a better chance of freedom from cardiac events as well as need for anticoagulation 10 years after surgery.

Faringitis aguda, ¿estreptocóccica? Empleo del estudio etiológico y de antimicrobianos en dos centros pediátricos universitarios / Sore throat, ¿streptococcal etiology? Use of etiological screening and antimicrobial prescription in two university pediatric centers

Se describen aspectos clínicos, del diagnóstico y tratamiento de faringitis en pacientes pediátricos, 421 en un centro ambulatorio y 289 en la unidad de emergencia de un hospital universitario, que consultaron en un periodo de 14 meses. En los centros respectivos hubo 65 y 76 por ciento de pacientes en que se realizaron exámenes para documentar la etiología estreptocóccica. Se demostró la existencia de Streptococcus pyogenes en 37 por ciento de los explorados, siendo similar en ambos centros, con una incidencia máxima de 50 por ciento en el grupo etario de 6 a 10 años. En 217 pacientes no se realizó estudio etiológico, de éstos 162 (75 por ciento) recibieron tratamiento antimicrobiano. Se enfatiza la importancia de los exámenes de confirmación bacteriológica para la correcta indicación de antimicrobianos en esta patología.

Ciruguía reparadora de la válvula aórtica bicúspide insuficiente / Valve repair surgery for incompetent bicuspid aortic valves

Background: Surgical valve repair is a good alternative for correction of incompetent bicuspid aortic valve. Aim: To report the early and late surgical, clinical and ecochardiographic results of surgical repair of incompetent bicuspid aortic valves. Patients and methods: Retrospective review of medical records of 18 patients aged 19 to 61 years, with incompetent bicuspid aortic valve in whom a valve repair was performed. Four patients had infectious endocarditis and 17 were in functional class I or II. Follow up ranged from 3 to 113 months after surgery. Results: A triangular resection of the prolapsing larger cusp, which included the middle raphe, was performed in 17 cases; in 13 of these, a complementary subcommisural annuloplasty was performed. In the remaining case, with a perforation of the non-coronary cusp, a pericardial patch was implanted; this procedure was also performed in 2 other cases. In 3 cases large vegetations were removed. Postoperative transesophageal echocardiography showed no regurgitation in 11 patients (62percent) and mild regurgitation in 7 (38percent). There was no operative morbidity or mortality. There were no deaths during the follow-up period. In 3 patients (17percent) the aortic valve was replaced with a mechanical prosthesis, 8 to 108 months after the first operation. Reoperation was not needed in 93percent±6,4percent at 1 year and 85percent±9,5percentat 5 years, these patients were all in functional class I at the end of the follow-up period. 60percen had no aortic regurgitation, 20percent had mild and 20percent moderate aortic regurgitation on echocardiographic examination. A significant reduction of the diastolic diameter of the left ventricle was observed, but there were no significant changes in systolic diameter or shortening fraction. Conclusions: Surgical repair of incompetent bicuspid aortic valves has low operative morbidity and mortality and has a low risk of reoperation.

Cirugía valvular reparadora en endocarditis infecciosa / Valve repair surgery in infectious endocarditis

Background: Valve replacement has been the treatment of choice for patients with valvular complications of infectious endocarditis (IE). However, excellent results with valve repair allowed it to become a new therapeutic alternative for these patients. Aim: To evaluate the results of valve repair in patients with valvular complications of IE. Patients and Methods: From January 1991 to December 2000, 14 patients with valvular complications of IE underwent valve repair. Mean age was 37.9 ± 14.9. Results: New York Heart Association (NYHA) class was 2.8 ± 0.9. IE was located in the aortic in 6 (42 percent), in the mitral valve in 4 (29 percent) and in both valves in 4 cases (29 percent). Surgical indication was hemodynamic in 50 percent of the cases, echocardiographic in 29 percent and septic in 21 percent. Five aortic valves were bicuspid, 3 mitral valves were myxomatous and the rest were normal. The most common septic lesions were vegetations and leaflet perforations. A total of 23 aortic and 21 mitral valve repair procedures were performed. There were no deaths. Only 1 patient had a surgical complication (renal failure and prolonged mechanical ventilation). Follow-up was 100 percent complete. There was not late mortality. One patient with bone marrow aplasia required reoperation for a new episode of IE 19 months later. At the end of the follow-up NYHA class was 1.3 ± 0.6 and echocardiography showed a mild or absence of valve regurgitation in most patients. Conclusions: Valve repair surgery in IE has good results, with advantages over valve replacement (Rev MÚd Chile 2004; 132: 307-15).

Resultados alejados de la cirugía reparadora de la insuficiencia mitral degenerativa / Long-term results of repair surgery of degenerative mitral insufficiency

Background: Mitral valve repair is probably the procedure of choice for the surgical treatment of degenerative mitral insufficiency. Aim: To evaluate the late results of mitral valve repair in degenerative mitral insufficiency. Patients and method: The records of 88 patients who underwent mitral valve repair for degenerative mitral insufficiency from December 1991 through June 2002 were reviewed. Mean age was 59.9 years (range 22 to 82). At least moderate mitral insufficiency was present in every patient. Mean left atrial diameter was 55 mm and mean end diastolic and end systolic left ventricular diameters were 61 and 37 mm respectively. Results: The most common underlying lesion was ruptured chordae tendineae (66%) and posterior leaflet prolapse (68%). The surgical procedure most frecuently performed was quadrilateral resection of the posterior leaflet (68%). A Carpentier-Edwards ring was placed in 97% of patients. An associated procedure was performed in 34%. Operative mortality was 2.3%. A complete follow up was obtained in 93% of cases with a mean of 54±36 months. Overall survival rate was 98% at one year, 88% at 5 and 82% at 10 years. Free of cardiac death rates were 94% at 5 and 89% at 10 years. Only 2 patients were reoperated during follow up, resulting in a 98% reoperation free rate follow up. Functional class improved in all patients at the end of follow up. Late echocardiographic evaluation showed absent or minimal mitral regurgitation in 83% and mild mitral regurgitation in 17%. Conclusion: Good late results have been obtained with mitral valve repair, avoiding the inconveniencies of prosthetic replacement. Therefore, mitral valve repair should be the procedure of choice to treat degenerative mitral insufficiency (Rev Méd Chile 2003; 131: 1355-64).

Falla cardio respiratoria severa tratada con asistencia cardiopulmonar extracorpórea: caso clínico / Treatment of severe respiratory failure with cardiopulmonary extracorporeal assistance

Cardiopulmonary extracorporeal assistance is a high complexity procedure for patients with acute respiratory failure, who have failed conventional ventilatory support. A 30 years old female patient with bacterial endocarditis and congestive cardiac failure subjected to cardiac surgery presented severe hypoxemia, right heart failure and pulmonary hypertension, and failed conventional treatment. Cardiopulmonary support with extracorporeal membrane oxygenation (ECMO) reverted the pathophysiologic alterations allowing a successful recovery

Cirugía de la insuficiencia mitral isquémica / Surgery for ischemic mitral regurgitation

Background. Ischemic mitral regurgitation (IMR) is a severe condition which may be best treated by surgery, nowithstanding a relatively high mortality rate. Objectives. To evaluate the results of mitral valve replacement or repair in patients with IMR. Patients and methods. Retrospective review of the clinical records in 29 patients with IMR who were surgically treated from 1990 to 1999. They represent 8 percent of surgical procedures on the mitral valve. Results. Mean age was 67 ñ 9 years. Surgery was performed urgently in 19 patients (66,5 percent). NYHA functional class was 3.4 ñ 0.8. The mechanism of IMR was annular dilatation and spreading of papillary muscles in 18 patients, papillary muscle rupture in 9 and fibrosis in 2. Mitral valve replacement was performed in 14 patients and mitral valve repair in 15. Twenty four patients (83 percent) had concomitant myocardial revascularization. Overall surgical mortality was 24 percent; 26 percent for mitral replacement and 13 percent for mitral valve repair (p=0.215). On follow up of 26ñ33 months, one year survival was 76ñ0.8 percent and 5 years survival was 59ñ12 percent. Excluding in hospital mortality, survival was 100 percent at one year and 78ñ14 percent at 5 years. Functional class improved in all survivors, to 1.4ñ0.5. Late echocardiographic evaluation of patients with mitral valve repair showed absence of mitral regurgitation in 58 percent, 1+ MR in 17 percent and 2+ MR in 25 percent. Conclusion. In spite of a high perioperative mortality, surgery for IMR is a valuable procedure for patients with an otherwise highly lethal disease