José Carlos Dorsa Vieira Pontes

The ischemic preconditioning and postconditioning effect on the intestinal mucosa of rats undergoing mesenteric ischemia/reperfusion procedure

PURPOSE To evaluate the effect of the ischemic preconditioning and the ischemic postconditioning over the tissue injury in the intestinal mucosa of rats undergoing the procedure of mesenteric ischemia and reperfusion. METHODS Thirty Wistar rats were studied, divided in three groups: group A, undergoing mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion preceded by ischemic preconditioning; group C, mesenteric ischemia and reperfusion and, before the beginning of reperfusion, the ischemic postconditioning was performed. At the end, a segment of the small intestine was dissected for histological analysis. The results were evaluated using the CHIU et al.6 classification followed by the statistic treatment. RESULTS The mean values of the tissue injury levels were: group A, 3.5; group B, 1.2; and group C, 1. The difference between the result of group A with the results of groups B and C was considered statistically significant (p < 0,05). CONCLUSION The ischemic preconditioning and postconditioning are able to minimize the tissue injury in the intestines of rats that underwent the procedure of mesenteric ischemia and reperfusion.

Evaluation of ischemic postconditioning effect on mesenteric ischemia treatment: experimental study in rats

OBJECTIVE To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure. METHODS Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed. RESULTS According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05). CONCLUSION Ischemic pre- and postconditioning were capable of minimizing - in a similar intensity - the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process.

Terapêutica medicamentosa na isquemia e reperfusão mesentérica: revisão da literatura

Ate pouco tempo atras se acreditava que na isquemia mesenterica todas as alteracoes orgânicas desta afeccao eram devidas a obstrucao total ou parcial do fluxo arterial intestinal. Recentes descobertas quanto a fisiopatologia do processo de isquemia e reperfusao mesenterica demonstraram que os radicais livres, principalmente, atuam durante a reperfusao, levando a lesao tecidual muito mais importante do que as lesoes que ocorrem na fase de isquemia isoladamente. Assim, surge uma nova possibilidade terapeutica alem do tratamento cirurgico, em que uma determinada substância poderia atuar de modo a inibir ou minimizar a cascata de alteracoes no nivel celular que culminam na lesao e morte celular. Realizamos uma ampla revisao da literatura medica atual pelos bancos de dados LILACS e MEDLINE, visando verificar quais os farmacos estudados para este fim e os resultados obtidos nas pesquisas. Constatamos que inumeras substâncias tem sido avaliadas em estudos experimentais, em sua maioria utilizando ratos e a maioria nao apresentou resultados satisfatorios a ponto de permitirem seu emprego na pratica clinica; algumas, entretanto, apresentaram resultados promissores, necessitando ainda de novos estudos a fim de se descobrir uma substância que possa ser empregada em seres humanos em situacoes de isquemia e reperfusao mesenterica, a fim de se evitar tratamentos intervencionistas com altos indices de morbi-mortalidade.

Avaliação do pós-condicionamento isquêmico no tratamento da isquemia mesentérica: estudo experimental em ratos

OBJECTIVE To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure. METHODS Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed. RESULTS According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05). CONCLUSION Ischemic pre- and postconditioning were capable of minimizing - in a similar intensity - the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process.

Uso do propofol (2,6 diisopropilfenol) como inibidor da lesão tecidual na isquemia e reperfusão mesentérica: estudo experimental em ratos

PURPOSE: Evaluate the effects of propofol as inhibitor of tissue lesion in mesenteric ischemia and reperfusion in rats. METHODS: Forty rats Wistar were submitted to anesthesia and middle laparotomy. Intestinal ischemia was obtained by false ligature of cranial mesenteric artery by thirty minutes. Then, the tissue was reperfused for sixty minutes. The half of the animals received physiologic solution 0,9% 10 ml/kg/h (control group) by intravenous infusion; the other half received propofol 20 mg/kg/h by same way (propofol group). At the end, a segment of intestine was taken for histologycal analysis. The results were analyzed in agreement with CHIU et al 80 classification and the statistical analysis was done. RESULTS: In the control group was founded 5 rats with classification grade 2; 8 with classification grade 3; 3 with classification grade 4 and 4 rats with grade. In the propofol group was found 6 rats with classification grade 1; 11 with classification grade 2 and 3 with classification grade 3. The classification media was 3,3 for control group and 1,85 for the propofol group. The variation in the two groups was considered statistically significant (P < 0,05). CONCLUSION: The propofol minimize the tissue lesion in mesenteric ischemia and reperfusion in rats.

Postconditioning effect in the hepatic ischemia and reperfusion in rats

PURPOSE To evaluate the effect of postconditioning protection in liver tissue of rats submitted to ischemia and reperfusion. METHODS 25 Wistar male rats were randomized in three groups: Group A (ischemia and reperfusion - I/R), with 10 rats, which was made ischemia by vascular clamp application in hepatic hilum for 30 minutes and reperfusion for 60 minutes by removal of the clamp; Group B (Postconditioning - IPo), with 10 rats, with same procedure plus postconditioning (3 cycles of reperfusion inserted by 3 cycles of ischemia, 30 seconds for each phase, between ischemia and reperfusion phases); and Group C (Sham), with 5 rats, which took place only laparotomy and manipulation of the hepatic hilum. Specimens were examined (histological evaluation) and dosage of serum AST and ALT was made. The statistical analysis was made with t Student test, with significant difference when p<0.05. RESULTS In the Sham group there was no histological or enzymatic changes; In group A the mean tissue lesion was 1.6 and in group B 1.1 (p=0.014). In group A the mean ALT level was 355U/l and in group B was 175.9U/l (p=0.016). The mean of AST was 828.8U/l in group A and 295.5U/l in group B (p=0.001). CONCLUSION The postconditioning was able to minimize the severity of liver injury in rats submitted to ischemia and reperfusion.

Fatores de risco no desenvolvimento de insuficiência renal aguda após cirurgia de revascularização miocárdica com CEC

OBJECTIVES To evaluate incidence, mortality, and risk factors related to the development of acute renal failure (ARF) after on-pump coronary artery bypass grafting (CABG), between January 2002 and November 2004. METHODS Seventy four patients who underwent on-pump CABG were analyzed retrospectively and distributed into two groups according to the development of ARF. Bivariate and multivariate analyses were performed to analyze. P < 0.05 was considered statistically significant. RESULTS During the period analyzed, 18 patients (24.32%) developed acute renal failure (ARF); 1 patient (1.35%), who required dialysis, died. Associated risk factors identified in-between the development of ARF was: the postoperative use of inotropic or vasoconstrictor drugs (p=0.048) and body mass index greater than 25 (p=0.004). The CPB time did not determine the ARF increase (p=0.0668). CONCLUSION The CPB time was not associated with an increased of ARF following on-pump CABG.

New technical approach for crossed papillopexy in mitral valve replacement surgery: short term results

OBJECTIVE: To present the crossed papillopexy technique and its initial results in the preservation of papillary muscles in mitral valve replacement and ventricular remodeling surgeries for heart failure (CHF). METHOD: Ten patients, 70% male, with ages between 15 and 75 years old (mean 44.4 ± 18.7 years old), suffering from rheumatic mitral valve disease (50%), mitral valve prolapse (10%) or dilated cardiomyopathy (40%), were studied. After opening the left atrium and adequate exposure of the mitral valve, the anterior leaflet already free of its annulus fixation was centrally divided and each half, with its cordae tendineae complex fixed to the commissure on the opposite side. Following this, mechanical (seven cases) or biological (three cases) prostheses were implanted using single sutures in the valve annuli, with reduction of the mitral valve annulus for better ventricular remodeling in CHF cases. RESULTS: All patients were discharged from hospital in good clinical conditions. Additionally all presented with great improvement in the cardiac performance at the end of the first month of follow-up, with significant reductions in the left ventricular and left atrium systolic diameters (p<0.05) and mean increases in the left ventricle ejection fraction of from 46.7 to 56.4 % (p<0.05). CONCLUSION: The crossed papillopexy technique in valve replacement surgeries for mitral valve lesions and CHF presented significant increases in the left ventricular function and improvement of ventricular remodeling in the studied postoperative period.

Initial and pioneer experience of transcatheter aortic valve implantation (Inovare) through femoral or iliac artery

OBJECTIVE This paper demonstrates the initial and pioneering experience implant of the Inovare prosthesis implant through transfemoral or iliac artery route. METHODS Six patients underwent transcatheter aortic valve implantation. The access was femoral or iliac through which the delivery device, a latex balloon catheter with the crimped prosthesis, was inserted. Through the femoral introducer 24 Fr Gore® DrySeal sheath, an extra stiff guide wire with non-traumatic tip was positioned in the left ventricle by passing through the valve ring. After balloon valvuloplasty, in cases of native valve stenosis, the prosthesis implantation was performed after hypotension induced by tachycardia and controlled by temporary pacemaker. The valve positioning was guided by TEE (transesophageal ecocardiography) and fluoroscopy, aiming to position a third of the length of the prosthesis into the left ventricle cavity. RESULTS The successful valve implantation was possible in six cases. There was no need of conversion to open surgery due to inability to access or graft migration. There were no intraoperative or hospital deaths. We observed a significant reduction in the mean gradient of 66.84115.46 mmHg to 19.74110.61 mm Hg postoperatively (P=0.002), a reduction of 70.46%. CONCLUSION Inovare prosthesis, implanted by femoral or iliac artery was feasible, and determined adequate hemodynamic performance in the postoperative follow-up, showing no mortality in this small series.

Multiple left atrial myxoma: case report

Primary cardiac tumors are infrequent, with an incidence between 0.001% and 0.2%, mostly comprising benign histological characteristics in 75% of these cases. Myxomas account for approximately 50% of these neoplasms. As regards location, 75-80% of myxomas are in the left atrium, 18% in the right atrium, and more rarely in the ventricles. We report a case of a patient in functional class (FC) IV New York Heart Association (NYHA) and postoperative histological diagnosis of multilobular myxoma originating in the posterior left atrial wall. Clinical evaluation 3 months after surgery suggested NYHA functional class I and echocardiographic absence of intracardiac masses.