Rubio Bombonato

Partial left ventriculectomy:: Preoperative risk factors for perioperative mortality

This study aimed at determining risk factors for perioperative mortality for patients undergoing partial left ventriculectomy. Fourteen patients with end-stage congestive heart failure underwent partial ventriculectomy at our institution from February, 1995 to October, 1997. Mean age was 48+/-11 years, symptoms duration 44+/-34 months, New York Heart Association symptoms score 4+/-0, systolic blood pressure 97.69+/-20.06 mmHg, diastolic blood pressure 65.38+/-13.91 mmHg, heart rate 91+/-15 beats/min, furosemide daily dose 121.66+/-96.65 mg and captopril daily dose 68.75+/-76.76 mg. Seven (50%) patients needed inotropic support for hemodynamic stabilization. On echocardiography, left ventricular diastolic dimension was 81.71+/-11.92 mm. Left ventricular ejection fraction determined by radionuclide ventriculography or echocardiography was 16.71+/-5.13. At heart catheterization, mean right atrial pressure was 12.50+/-7.72 mmHg, mean pulmonary capillary wedge pressure 23.60+/-7.79 mmHg, and mean pulmonary artery pressure 34.10+/-12.81 mmHg. Twelve patients had idiopathic dilated cardiomyopathy and two patients had a globally dilated heart with single vessel coronary artery disease. Aneurysmectomy, mitral valve surgery or coronary artery bypass surgery were not performed in any patient. Four (28%) patients died: three in the operating theatre and one from low output syndrome 2 days after surgery. The proportion of patients operated on with cardiogenic shock was four (100%) in nonsurvivors and 0% in survivors (P=0.001). Inotropic support was necessary in three (30%) survivors and in four (100%) nonsurvivors (P=0.06). Thus, preoperative hemodynamic instability may be associated with perioperative mortality after partial left ventriculectomy.

Reação histopatológica da parede da aorta abdominal ao stent não recoberto

Objective: To evaluate the histopathological reaction of the abdominal aorta wall in pigs’ renal arteries to the presence of non-covered stainless steel stents. Methods: The abdominal aorta of ten pigs (6 months old and weighing 86.6 kg on average) was histopathologically studied 100 days after the implant of stainless steel stents in the abdominal aorta, with one segment of the stent implanted in the renal artery. Self-expanding non-covered stents were released by laparotomy. The histological slices were made at the transition from the normal aorta and the aorta containing the stent; the aorta portion containing the stent; the portion with the ostia of renal arteries; periaortic lymph nodes and renal parenchyma. The samples were stained by the hematoxylin and eosin technique. Results: Macroscopic findings showed periaortic lymphadenopathy, thickened aortic wall, patency of lumbar and renal arteries and normal renal anatomical structure. Microscopic analyses near the stents revealed thickening of vessel wall secondary to intima fibrosis, and media layer affected by interstitial fibrosis. Micrometric measurements of aorta wall with the stent, compared to the aortic portion without it, presented a 75.90% increase in the total thickness of the wall by thickening of the intima layer secondary to fibroblast proliferation, collagen deposits with lymphocytary inflammatory infiltrate and foreign body-type granulomas. Conclusion: The non-covered stainless steel stents in pigs’ aortas produced a significant inflammatory reaction with fibrosis in the media and intima layers evidenced by histopathological analyses; their presence did not interfere in the patency of the abdominal aorta or the renal and lumbar arteries.

O stent descoberto não promove reações em artérias renais e parênquima renal em suínos

OBJECTIVE: To assess the histological changes of the aorta, the renal arteries and the renal parenchyma in swine, induced by a metalic uncovered stent implanted in transrenal position in the abdominal aorta. METHODS: Ten pigs with a mean weight of 86.6 kg and mean age of 6 months underwent implantation of metal stent graft placed in the aorta at the level of the renal arteries after 100 days of implantation. The self-expanding stents were released by laparotomy. Anatomic and histological analyses of the abdominal aorta, the renal arteries and the renal parenchyma were performed. Histological slices were performed in the following sites: 1) transitional zone between the aorta with and without stent graft; 2) portion of the renal arteries ostia; 3) renal parenchyma. The slices were stained through the hematoxylin and eosin stain technique and analyzed according the protocol of histological analyses applied in the clinical practice of pathology labs. RESULTS: The macroscopic findings showed thickening of the aortic wall; patent renal arteries; and normal anatomic renal structures. Microscopic analyses, close to the stents, showed thickening of the vascular wall, renal arteries without changes, and preserved renal parenchyma. CONCLUSION: The uncovered stainless steel stent caused a significant inflammatory reaction with thickening of the aortic wall. However, the renal arteries remained patent and the renal parenchyma did not present embolic or ischemic changes.

Experiência com dois tipos de técnicas para o tratamento cirúrgico da insuficiência mitral: I. Prótese com preservação de elementos do sistema valvar. II. Plastia valvar com reconstrução e avanço da cúspide posterior

The continuity between mitral valve and the left ventricular wall through chordae tendinae and papillary muscles plays a role in left ventricular function. The morbity and mortality for mitral valve replacement remain much higher than other cardiac procedures such as aortic valve replacement, mitral valvuloplasty and coronary artery bypass grafts. These facts justify all possible studies related to the correction of mitral valve insufficiency. The present paper presents our experience with two techniques for correction of mitral valve insufficiency: valve replacement with preservation of the mitral apparatus components and valvuloplasty by the reconstruction and advancement leaflet. Our main concern was the surgical details and ventricular function studies were not performed. Various techniques to maintain continuity of the mitral valve annulus and the ventricular musculature, when valve replacements is mandatory, are presented. The importance of the reconstruction and advancement of the posterior leaflet, alone or associated with other repair techniques such as comissurotomy, annuloplasty and shortening of chordae tendinae, is emphasized.

Implante de marcapasso ventricular esquerdo no tratamento da miocardiopatia dilatada e bloqueio de ramo esquerdo associado a discinesia de contraçäo septal

Left branch bundle block may present as an isolated entity, even in normal hearts, in which apparently it does not impair the left ventricular function importantly. Studies in LBBB created by the implant of a right ventricular pacemeker, have shown deleterious effects on left ventricle systolic and diastolic functions associated sometimes with presence of mitral valve regurgitation. Paradoxical interventricular septal motion that follows the LBBB cause an additional impairment of left ventricular function and is in general present in patients with cardiomyopathy and congestive heart failure, with poor prognosis. In 1994 studying patients with cardiomyopathy Cazeau demonstrated that the use of four chamber pacing can increase cardiac output and decrease pulmonary capillary wedge pressures. Stimulated by this work, we decided to investigate the possibility of stimulation of the left ventricle apex alone, after sensing the P wave by the use of a dual-chamber pacemaker in patients with LBBB and paradoxical septal movement, aiming at the synchronization of interventricular septal contraction. This procedure was done in three patients and before hospital discharge they were submitted to echocardiographic studies with the pacemaker turned on and scintigraphy off to analyze the ejection fraction and the septal movement. In the first case the EF increased from 17 to 25%; in the second from 13 to 30% and in the third from 13 to 27%. The paradoxical movement disappeared in two cases and was classified as mild (+/+4+) in the first case. The functional class and mitral regurgitation were not included in this study because all three patients had combined procedures which could induce a false-positive improvement. Although this is a small number of cases, we believe that the procedure is promising for the treatment of patients with congestive heart failure, cardiomyopathy, left bundle branch block and paradoxical septal movement and it might be a future indication for the treatment of LBBB, before the deterioration of the left ventricle happens changing the quality of life and survival of these patients.

Plastia valvar aórtica por ampliação de válvula(s) com pericárdio bovino

E apresentada tecnica para correcao do refluxo valvar aortico pela desinsercao e ampliacao de uma ou mais das valvulas com pericardio bovino. Apos estudo experimental em pecas animais isoladas, a tecnica foi empregada, com sucesso imediato, em seis pacientes. Em todos os casos, ampliou-se a valvula nao coronariana e, em dois, ampliou-se, tambem, a valvula coronariana esquerda. O levantamento das comissuras valvares podera constituir-se em uma tecnica complementar, desde que foi uma constante em todos os pacientes operados. Uma paciente faleceu no setimo mes de pos-operatorio por endocardite bacteriana. Os demais pacientes encontram-se em periodos de observacao de quatro a 12 meses. As observacoes iniciais permitem afirmar que a tecnica e reproduzivel com bons resultados imediatos. A evolucao clinica a medio e a longo prazo e fundamental para uma apreciacao mais definitiva, sendo motivo de constante preocupacao a ocorrencia de endocardite bacteriana e as consequencias da evolucao do processo reumatico.

Histopathological reaction of the abdominal aorta wall to non-drug eluting stents

Objective: To evaluate the histopathological reaction of the abdominal aorta wall in pigs’ renal arteries to the presence of non-covered stainless steel stents. Methods: The abdominal aorta of ten pigs (6 months old and weighing 86.6 kg on average) was histopathologically studied 100 days after the implant of stainless steel stents in the abdominal aorta, with one segment of the stent implanted in the renal artery. Self-expanding non-covered stents were released by laparotomy. The histological slices were made at the transition from the normal aorta and the aorta containing the stent; the aorta portion containing the stent; the portion with the ostia of renal arteries; periaortic lymph nodes and renal parenchyma. The samples were stained by the hematoxylin and eosin technique. Results: Macroscopic findings showed periaortic lymphadenopathy, thickened aortic wall, patency of lumbar and renal arteries and normal renal anatomical structure. Microscopic analyses near the stents revealed thickening of vessel wall secondary to intima fibrosis, and media layer affected by interstitial fibrosis. Micrometric measurements of aorta wall with the stent, compared to the aortic portion without it, presented a 75.90% increase in the total thickness of the wall by thickening of the intima layer secondary to fibroblast proliferation, collagen deposits with lymphocytary inflammatory infiltrate and foreign body-type granulomas. Conclusion: The non-covered stainless steel stents in pigs’ aortas produced a significant inflammatory reaction with fibrosis in the media and intima layers evidenced by histopathological analyses; their presence did not interfere in the patency of the abdominal aorta or the renal and lumbar arteries.

Desenvolvimento de um projeto para construção de bomba-balão para contrapulsação aórtica

The present paper presents the project and construction of a balloon-pump for aortic counterpulsation. Three experimental models were developed, the first two using hospital air and vacuum lines for inflation and deflation of the balloon catheter. These two inicial models differes among themselves in the mechanism used to capture the light signal corresponding to the R wave of the ECG, which was used to sincronize the pumping. The solenoid valve and electronic components were of higher resolution in the second model. The third and present model recieves the R wave signal from the cardioversor adaptor of ECG monitor and the hospital vacuum and air lines along with the solenoid valve were substituted by an electromagnetic pump. The problems related to late deflation that have ocurred in the system are still in study. Emphasis is given on the importance of this research, which has incremented knowledge for the construction of other medical equipment, mainly in the area of respiratory care.

Contrapulsação aórtica intraoperatória pós circulação extracorpórea (CEC): apresentação de método

The authors present on a system to obtain the aortic counterpulsation-effect in the immediate period after cardiopulmonary bypass for cardiac surgery.