Luís Alberto Dallan

Effectiveness of the Maze Procedure Using Cooled-Tip Radiofrequency Ablation in Patients With Permanent Atrial Fibrillation and Rheumatic Mitral Valve Disease

Background—Although the Cox-Maze III procedure is effective for treating permanent atrial fibrillation (AF), its high complexity limits its use. The Saline-Irrigated Cooled-tip Radiofrequency Ablation (SICTRA) System is an alternative source of energy used to ablate AF. The aim of this study was to evaluate the effectiveness of the SICTRA for the treatment of permanent AF in patients with rheumatic mitral valve (MV) disease. Methods and Results—Between February 2002 and April 2003, 70 patients with permanent AF and rheumatic MV disease were randomly assigned to undergo a modified Maze III procedure using SICTRA associated with MV surgery (group A) or MV surgery alone (group B). Groups A and B were similar in terms of baseline characteristics. The in-hospital mortality rate was 2.3% (1 death) in group A versus 0% (no deaths) in group B (P>0.99). The additional time required for the left-sided radiofrequency ablation in group A was 14.2±5.1 minutes and for right-sided ablation was 12.3±4.2 minutes. The mean postoperative follow-up periods were 13.8±3.4 and 11.5±7.3 months, respectively, in groups A and B. The overall mid-term survival rate was 95.1% in group A and 92.8% in group B (P>0.99). The cumulative rates of sinus rhythm were 79.4% in group A and 26.9% in group B (P=0.001). Doppler echocardiography documented biatrial transport function in 90.3% of group A patients in sinus rhythm. Conclusions—The SICTRA is effective for treating permanent AF associated with rheumatic MV disease.

Extraanatomic aortic bypass for repair of aortic arch coarctation via sternotomy: midterm clinical and magnetic resonance imaging results.

BACKGROUND We analyzed our 22 years of experience with extraanatomic bypass grafting for repair of aortic arch coarctation in adults. Results from early and midterm follow-up with clinical evaluation and magnetic resonance angiography are reported. METHODS Between November 1979 and December 2001, 18 consecutive patients aged 18 to 61 years (mean, 31.8 +/- 13.3 years) underwent extraanatomic bypass grafting to repair coarctation of the aortic arch. Six patients (33.3%) had recoarctation after previous repair through a left thoracotomy, and 3 (16.7%) had associated cardiac diseases. The operative technique used in all patients was ascending aorta-to-descending thoracic aorta bypass with a polyethylene terephthalate fiber (Dacron) graft through a median sternotomy and posterior pericardial approach. RESULTS Follow-up was completed in all patients, with a mean duration of 5.6 +/- 5.7 years (range, 12 months to 22 years). The follow-up interval exceeded 10 years in 5 patients. No neurologic complications, early or late mortality, late reoperations, or graft complications occurred. Six patients (33.3%) had mild hypertension. All patients were asymptomatic with patent Dacron grafts confirmed by echocardiography. Magnetic resonance angiography, performed in 15 (83.3%) patients, revealed that the Dacron grafts were still patent at a mean interval of 4.0 +/- 6.2 years (range, 5 days to 22 years) after repair. CONCLUSIONS Extraanatomic ascending aorta-to-descending thoracic aorta bypass grafting for repair of aortic arch coarctation in adults is safe, with low morbidity and no mortality. The favorable midterm results indicate this technique is a safe and less invasive means of repairing aortic arch coarctation or recoarctation in adults.

Synergism Between Keratinocyte Growth Factor and Carboxymethyl Chitosan Reduces Pericardial Adhesions

BACKGROUND Mesothelial injury is the pivot in the development of adhesions. An increase in the proliferation of mesothelial cells was verified by in vitro studies with the use of keratinocyte growth factor (KGF). This study investigated the influence of KGF associated with thermo-sterilized carboxymethyl chitosan (NOCCts) in the reduction of pericardial adhesions. METHODS An induction model of pericardial adhesion was carried out in 24 pigs. Animals were randomly allocated to receive topical application of KGF, KGF + NOCCts, NOCCts, or saline (control). At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histologic sections were stained with sirius red for a morphometric evaluation using a computer-assisted image analysis system. Cytokeratin AE1/AE3 immunostaining were employed to identify mesothelial cells. RESULTS The severity score expressed in median (minimum to maximum), in relation to the control group (17 [15 to 18]), was lower in the KGF + NOCCts group (7 [6 to 9], p < 0.01) followed by the KGF group (11.5 [9 to 12], 0.01 < p < 0.05) and the NOCCts group (12 [9 to 14], p > 0.05). The dissection time was significantly lower in the KGF + NOCCts group (7.1 + or - 0.6 vs 33.9 + or - 9.2 minutes, p < 0.001). A significantly less sharp dissection was also required in the KGF + NOCCts group. In the adhesion segment, a decreased collagen proportion was found in the KGF + NOCCts group (p < 0.05). Mesothelial cells were present more extensively in groups in which KGF was delivered (p = 0.01). CONCLUSIONS The use of KGF associated with NOCCts resulted in a synergic action that decreases postoperative pericardial adhesions in a highly significant way.

Preditores de mortalidade hospitalar no paciente idoso portador de doença arterial coronária

Introduction: The trend in Brazil of erroneously delaying myocardial revascularization in the elderly determined this study. Three hundred consecutive elderly patients (mean age: 73.92, standard deviation: 3.32). Material and Methods: Between October 1992 and July 1995, 361 consecutive patients underwent isolated coronary artery bypass grafting, of whom 111 (30.7%) were females and 250 (69.35) males. There were 128 (35.5%) diabetic patients and 128 (36.7%) were in NYHA III/IV. Univariate analysis perioperatory of 19 factors followed by multivariate logistic regression analysis of the significant variables (p < 0.005) were done. Results: Major complication occurred in 178 (49.3%) and were independent predictors of operative morbidity: Diabetes mellitus, NYHA functional classification, urgent cases and DP2. There were 33 (9.1 %) in hospital deaths, and diabetes mellitus, NYHA functional classification, unstable preoperative angina and cerebral vascular accident, renal failure, infection and insufficiency respiratory failure were independent predictors of operative mortality. Conclusion: The coronary artery bypass grafting is possible in elderly patients with a favorable outcome, especially when done in patients with normal to moderately depressed left ventricular function.

Minimally invasive single-vessel coronary artery bypass with the internal thoracic artery and early postoperative angiography: midterm results of a prospective study in 120 consecutive patients

BACKGROUND This prospective study was undertaken to determine the role of the minimally invasive direct coronary artery bypass with early postoperative angiography and midterm follow-up in 120 consecutive patients with single-vessel coronary artery disease. METHODS Minimal access (6 to 10 cm), without complete sternotomy and no cardiopulmonary bypass, was used. The lesions were located at the proximal left anterior descending coronary artery in 95% of the patients. Routine coronary angiography was performed before discharge. RESULTS Postoperative angiography was performed in 104 (90.4%) of those 115 patients who had coronary revascularization concluded by the mini-access method. The internal thoracic artery patency rate was 98.1% (95.2% grade A). Two (1.7%) patients presented with perioperative myocardial infarction, which led to the single in-hospital death (0.8%). Of the remaining 119 patients, 113 (95.0%) were asymptomatic. The event-free probability was 94.9% and the actuarial survival was 98.3% with 42 months of follow-up. CONCLUSIONS For selected patients with single-vessel coronary artery disease and no major myocardial dysfunction, minimally invasive direct coronary artery bypass is a safe operation and a less invasive alternative to conventional coronary artery bypass grafting.

Fatores de risco pré-operatórios para mediastinite após cirurgia cardíaca: análise de 2768 pacientes

BACKGROUND Longitudinal median sternotomy is the most common surgical approach for access to heart disease treatment. The deep wound infections in postoperative period of cardiovascular surgery are a serious complication requiring high costs during treatment. Different studies have indicated some risk factors for the development of mediastinitis and preoperative variables are currently under investigation. OBJECTIVE The aim of this study is to identify the preoperative risk factors for postoperative development of mediastinitis in patients undergoing coronary artery bypass grafting and valve replacement. METHODS This observational study represents a cohort of 2768 consecutive operated patients. The period considered for analysis was from May 2007 to May 2009 and there were no exclusion criteria. Analysis was performed by univariate and multivariate logistic regression model of 38 preoperative variables. RESULTS Thirty-five (1.3%) patients developed mediastinitis and 19 (0.7%) associated with osteomyelitis. The patient age average was 59.9 ± 13.5 years and the EuroSCORE of 4.5 ± 3.6. Hospital mortality was 42.8%. The multivariate analysis identified three variables as independent predictors of postoperative mediastinitis: intra-aortic balloon pump (OR 5.41, 95% CI [1.83 -16.01], P = 0.002), hemodialysis (OR 4.87, 95% CI [1.41 to 16.86], P = 0.012) and extracardiac vascular intervention (OR 4.39, 95% CI [1.64 to 11.76], P = 0.003). CONCLUSION This study showed that necessity of preoperative hemodynamic support with intra-aortic balloon, hemodialysis, and extracardiac vascular intervention were risk factors for development of mediastinitis after cardiac surgery.INTRODUCAO: A esternotomia mediana longitudinal e a via de acesso mais utilizada no tratamento das doencas cardiacas. As infeccoes profundas da ferida operatoria no pos-operatorio das cirurgias cardiovasculares sao uma complicacao seria, com alto custo durante o tratamento. Diferentes estudos tem encontrado fatores de risco para o desenvolvimento de mediastinite e as variaveis pre-operatorias tem tido especial destaque. OBJETIVO: O objetivo deste estudo e identificar fatores de risco pre-operatorios para o desenvolvimento de mediastinite em pacientes submetidos a revascularizacao do miocardio e a substituicao valvar. METODOS: Este estudo observacional representa uma coorte de 2768 pacientes operados consecutivamente. O periodo considerado para analise foi de maio de 2007 a maio de 2009 e nao houve criterios de exclusao. Foi realizada analise univariada e multivariada pelo modelo de regressao logistica das 38 variaveis pre-operatorias eleitas. RESULTADOS: Nesta serie, 35 (1,3%) pacientes evoluiram com mediastinite e 19 (0,7%) com osteomielite associada. A idade media dos pacientes foi de 59,9 ± 13,5 anos e o EuroSCORE de 4,5 ± 3,6. A mortalidade hospitalar foi de 42,8%. Na analise multivariada, foram identificadas tres variaveis como preditoras independentes de mediastinite: balao intra-aortico (OR 5,41, 95% IC [1,83 -16,01], P=0,002), hemodialise (OR 4,87, 95% IC [1,41 - 16,86], P=0,012) e intervencao vascular extracardiaca (OR 4,39, 95% IC [1,64 - 11,76], P=0,003). CONCLUSAO: O presente estudo demonstrou que necessidade do suporte hemodinâmico pre-operatorio com balao intra-aortico, hemodialise e intervencao vascular extracardiaca sao fatores de risco para o desenvolvimento de mediastinite apos cirurgia cardiaca.

Keratinocyte growth factor: a new mesothelial targeted therapy to reduce postoperative pericardial adhesions.

BACKGROUND Several methods have been utilized to prevent pericardial and retrosternal adhesions, but none of them evaluated the mesothelial regenerative hypothesis. There are evidences that the mesothelial trauma reduces pericardial fibrinolytic capability and induces an adhesion process. Keratinocyte growth factor (KGF) has proven to improve mesothelial cells proliferation. This study investigated the influence of keratinocyte growth factor in reducing post-surgical adhesions. METHODS Twelve pigs were operated and an adhesion protocol was employed. Following a stratified randomization, the animals received a topical application of KGF or saline. At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histological sections were stained with sirius red and morphometric analyses were assessed with a computer-assisted image analysis system. RESULTS The severity score was lower in the KGF group than in the control group (11.5 vs 17, p=0.005). The dissection time was lower in the KGF group (9.2+/-1.4 min vs 33.9+/-9.2 min, p=0.004) and presented a significant correlation with the severity score (r=0.83, p=0.001). A significantly less sharp dissection was also required in the KGF group. Also, adhesion area and adhesion collagen were significantly lower in the KGF group than in the control group. CONCLUSION The stimulation of pericardial cells with KGF reduced the intensity of postoperative adhesions and facilitated the re-operation. This study suggests that the mesothelial regeneration is the new horizon in anti-adhesion therapies.

Human saphenous vein organ culture under controlled hemodynamic conditions

INTRODUCTION Saphenous vein grafting is still widely used to revascularize ischemic myocardium. The effectiveness of this procedure is limited by neointima formation and accelerated atherosclerosis, which frequently leads to graft occlusion. A better understanding of this process is important to clarify the mechanisms of vein graft disease and to aid in the formulation of strategies for prevention and/or therapeutics. OBJECTIVE To develop an ex vivo flow system that allows for controlled hemodynamics in order to mimic arterial and venous conditions. METHODS Human saphenous veins were cultured either under venous (flow: 5 ml/min) or arterial hemodynamic conditions (flow: 50 ml/min, pressure: 80 mmHg) for 1-, 2- and 4-day periods. Cell viability, cell density and apoptosis were compared before and after these intervals using MTT, Hoeschst 33258 stain, and TUNEL assays, respectively. RESULTS Fresh excised tissue segments were well preserved prior to the study. Hoechst 33258 and MTT stains showed progressive losses in cell density and cell viability in veins cultured under arterial hemodynamic conditions from 1 to 4 days, while no alterations were observed in veins cultured under venous conditions. Although the cell density from 1-day cultured veins under arterial conditions was similar to that of freshly excised veins, the TUNEL assay indicated that most of these cells were undergoing apoptosis. CONCLUSION The results observed resemble the events taking place during early in vivo arterial-vein grafting and provide evidence that an ex vivo perfusion system may be useful for the identification of new therapeutic targets that ameliorate vein graft remodeling and increase graft patency over time.

Fatores prognósticos na revascularização do miocárdio em pacientes idosos

The trend in Brazil of erroneously delaying myocardial revascularization in the elderly determined this study. Three hundred consecutive elderly patients (mean age: 73,92, standard deviation: 3.32). Between October 1992 and July 1995, 361 consecutive patients underwent isolated coronary artery bypass grafting, of whom 111 (30,7%) were females and 250 (69,35) males. There were 128 (35,5%) diabetic patients and 128 (36,7%) were in NYHA III/IV. Univariate analysis per-operatory of 19 factors followed by multivariate logistic regression analysis of the significant variables (p 0.005) were done. Major complication ocurred in 178 (49.3%) and were independent predictors of operative morbidity: Diabetes mellitus, NYHA funcional classification, urgent cases and DP2. There were 33 (9,1%) in hospital deaths, and diabetes mellitus, NYHA functional classification, unstable pre-operative angina and cerebral vascular acidents, renal failure, infection and insufficiency respiratory failure were independent predictors of operative mortality. We concluded that coronary artery bypass grafting is possible in elderly patients with a favorable outcome, especially when done in patients with normal to moderately depressed left ventricular function.

Os escores 2000 Bernstein-Parsonnet e EuroSCORE são similares na predição da mortalidade no Instituto do Coração-USP

OBJECTIVE: To evaluate the performance of 2000 Bernstein-Parsonnet (2000BP) and additive EuroSCORE (ES) for predicting surgical mortality at the Heart Institute, University of Sao Paulo. METHODS: A prospective observational design. Seven hundred and seventy four patients were operated for coronary artery bypass graft, valve or combined procedure between May and October, 2007, were analyzed. The mortality was estimated with the 2000BP and ES. The correlation between expected mortality and observed mortality was validated through calibration and discrimination test. RESULTS: The patients were stratified into five groups for the 2000BP and three for the ES. The Hosmer-Lemeshow test for 2000BP (P = 0.70) and for ES (P = 0.39) indicate a good calibration. The ROC curve for the 2000BP = 0.84 and for the ES = 0.81 confirms that the models are good predictors (P<0.001). CONCLUSION: Both models are similar and adequate in predicting surgical mortality at the InCor-USP.