Volume 11 - Número 4
EDITORIAL
ORIGINAL ARTICLE
Myocardial revascularization without cardiopulmonary bypass: results of 15 years' experience
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Myocardial revascularization without cardiopulmonary bypass is now a subject of increasing interest. The purpose of this paper is to present the results obtained during 15 years of experience. From September 1981 till March 1996,1549 patients we operated on without the use of cardiopulmonary bypass with an applicability of this alternative around 18% of the total revascularized patients in this period. The ages varied from 28 to 86 years (medium 57) with 1126 males and 423 females. The number of grafts varied from 1 to 5 (medium 1.7 grafts/patient). The technique did not constitute special limitation to use arterial grafts. The thoracic internal arteries were used 1140 times. In 1515 patients the revascularization was achieved through medsternotomy and in 34 through a minor left anterior thoracotomy. The mortality rate was 2.4% (38/1549) the main primary cause of death, low cardiac output in patients operated under acute ischemia after failed angioplasty or evolving mycardial infarction. In 8 patients the revascularization was performed under intraaortic balloon pump. The results of this 15 years experience permit the conclusion that myocardial revascularization without extracorporeal circulation is an excelent alternative of surgical treatment of coronary artery disease for a subset of patients with lower mortality and morbidity being specially indicated in high risk patients.
Keywords: Myocardial ischemia, surgery; Myocardial revascularization, methods; Extracorporeal circulation; Surgery, minimally invasive
Coronary artery surgery with thoracoscopy
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
The benefits of the internal mammary artery (IMA), as a graft, particularly for the left anterior descending (LAD) coronary artery disease, have been demonstrated. Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) is now an accepted technique of myocardial revascularization. Thoracoscopy and a minimal thoracotomy have been applied to cardiac surgery, however its use has not been well defined. In our approach, we harvested the left or the right IMA thoracoscopically. Following this the left IMA-LAD or right IMA-right coronary artery anastomoses were fashioned, by means of a left or right small anterior thoracotomy on the beating heart without CPB. A double lumen endotracheal tube was used so the lung could be collapsed. Three left or right lateral chest ports of 1.5 cm were made, and the thoracoscope was placed through the initial port, permitting inspection of the thorax. The other ports were used for IMA dissection, using endoscopic instruments (electrocautery, grasping, forceps,...), the side branches were controlled by either cautery or endoscopic clips. When it was possible, the anterior port was extended doing a small left or right anterior thoracotomy, the pericardium was exposed, the IMA was divided and exteriorized through the thoracotomy. After coronary artery control, the bypass graft was carried out on the beating heart without CPB. In certain cases, when myocardial protection was considered to be essential, this was achieved by means of an intracoronary shunt. We have operated on more than 20 patients using this technique with good results in all cases. We believe that with increasing operator experience, this minimally invasive approach will have a major impact on the management of the coronary artery disease patients, with a faster recovery, shorter hospitalization, and certainly less cost.
Keywords: Myocardial revascularization, methods; Thoracic arteries, surgery; Coronary vessels, surgery; Thoracoscopy; Surgery, minimally invasive
Comparative analysis of two methods of myocardial protection
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
OBJECTIVE: To compare the tradicional myocardial protection achieved by crystalloid cold cardioplegia, which is induced through the aortic root, associated to systemic hypothermia and intermitent aortic cross-clamping (Group I) to warm blood cardioplegia using induction through the aortic root but retrograde maintenance through the coronary sinus, associated to systemic normothermia. METHODS AND MATERIAL: During the period ranging from May 1992 to May 1994, two groups of 50 patients were selected consecutively, but not randomized, according to requirements that increased the morbidity and mortality associated to the Coronary Artery Bypass Graft (CABG). All selected patients presented at the time clinical instability, more than three coronary arteries (or the left main coronary artery) occluded or severely suboccluded, associated with severe LV dysfunction of ischemic ethiology. RESULTS: The two groups were comparable according to the variabilities found in the period just prior to the surgery. Group II had a larger amount of grafts (3.82x3.40), consequently a longer period of aortic cross-clamping (70.74x62.06 min) and a longer time in cardiopulmonary bypass (CPB) (97.5x93.8 min). Group I, in average, needed more inotropic agents for the weaning process from CPB, more use of mechanical assist devices and showed a bigger incidence of acute myocardial infarction as well as ventricular fibrilation after aortic cross-clamp release. This group also had less incidence of prolonged mechanical ventilation, greater early and global mortality, and also a larger number of deaths due to other cardiac causes. CONCLUSION: The two groups were not comparable due to the larger number of grafts in Group II turning them more critical than Group I. Nervertheless, the results from Group II were superior to Group I, even though the statistic analysis do not corroborate those results. That, associated with clinical data, technical improvement and recognizing the limitations of the procedure, made us use it in this specific group of patients.
Keywords: Heart arrest, induced, methods; Myocardial revascularization, risk factors; Myocardial revascularization, comparative study
Use of nimodipine for cerebral injury prophylaxis in surgical myocardial revascularization with extracorporeal circulation in elderly patients
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Around 5 percent of the patients submitted to heart surgery with extracorporeal circulation present neurological problems. In relation to neuropsicological functions the alteration rate achieve 50 to 70%. An independent variable to stroke is age, the frequency in patients older then 75 years is close to 9%. Taking in account that rate of the elderly population grows very fast and that the coronary patient are frequently older than 65 years, we found very important to search for prophylactic ways to reduce this incidence. New drugs promise to achieve the goal of a prophylaxis of the cerebral injury induced by extracorporeal circulation and nimodipine, a neurovascular specific calcium channel blocker, seems to be a great promise for the prevention of cerebral damage. This is a pilot, double blind, randomized and controlling study with 64 patients, 30 in the nimodipine group and 34 in the placebo branch. Demographics and preoperative data were similar, without any significative difference but the incidence of previous transitory ischaemic attack. The nimodipine group shows a reduction in the number of neurological events in comparation with the placebo group, although a most complicated surgical procedure and inter and post-operative evolution. In the nimodipine group 3 patients presented mental confusion but in the placebo branch we found also 3 cases of mental confusion plus 2 cases of drowsy and one ischaemic stroke with sequels. In summary in the nimodipine group were 3 cases in 30 patients (10%) against 6 in 34 patients (17.64%) in one placebo group. It means a neurological events reduction of 76.4%. Legault reported high mortality in patients using nimodipine in cardiac valve replacement surgery, mainly related to bleeding. We don't found such correlation. The hospital - mortality was similiar in both groups (1 patient in each group) and non statistically significant difference in bleeding (1 severe case in the nimodipine group). In the follow up till 41 months there was a higher mortality in the placebo (4 patients) than in the nimodipine group (1 case).
Keywords: Myocardial revascularization; Cerebral ischemia, prevention and control; Confusion, prevention and control; Nimodipine, therapeutic use; Nimodipine, administration and dosage; Myocardial revacularizatton, mortality; Extracorporeal circulation, adverse eff
Surgical treatment of endocarditis with abscess in the valvular ring: immediate and long-term results
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Between October 1978 and December 1994, 619 cases of bacterial endocarditis were treated in the Heart Institute. Of these, 208 were submitted to surgical treatment, and 65 presented abscess in the valvular ring. Forty eight (73.8%) were male, their ages varying from 6 to 61 years, with average of 38.3 +/-11.9 years. Forty six (70.8%) presented a valvular prosthesis (37 aortic and 11 mitral). The microorganisms most commonly found were Streptococcus viridans in 17 (26.2%) patients, Enterococcus sp in 6 (7.7%), and Staphylococcus aureus in 9 (13.8%). Nine patients presented PR interval longer than 0.20 mseg in the pre operative eletrocardiography. The indications for operation were prosthetic valve endocarditis in 46 cases (70.8%), heart failure in 9 (13.8%), failure in clinical treatment in 5 (7.7%), embolism in 2 (3.1%), fungal endocarditis in 1 (1.5%), and others in 2 (3.1 %). The immediate mortality was 17 (26.2%) patients. There were 9 (13.8%) late deaths; of these, 5 presented a new episode of bacterial endocarditis. Thirty seven (86%) patients were in class I (NYHA), 4 in FC II, and 2 in FC III in the late postoperative period, with a mean followup of 5.3 years.These results show that the bacterial endocarditis associated with abscess in the valvular ring is a high risk pathology, the treatment is surgical, and the most common late complication is the reinfection.
Keywords: Abscess, surgery; Aortic valve, surgery; Endocardites, bacterial, surgery
Late outcome of unsupported annuloplasty as surgical treatment of mitral insufficiency in children and adolescents
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Late post-operative clinical results fortreatmentof mitral regurgitation (MR) in patients under 18 years-old by annuloplasty without ring or posterior support are presented. From 1977 to 1995,70 patients: 36 female and 34 male, mean age 12.4 ± 4.8 y (6m to 18y), with pure MR were submitted to an Wooler type of annuloplasty. None received ring or annular support. Twelve (17.1%) had chordal shortening associated. Ethiology was rheumatic 71.4%, congenital 18.6%, myxomatous 8.6% and infectious 1.4%. Preoperative functional class was II: 32 cases (45.7%), III: 18 (25.7%), IV: 20 (28.6%). Twenty-one patients (30%) had associated procedures: on aortic valve 12 (15.2%), tricuspid 4 (5.7%), ASD 4 (5.7%) and aortic and tricuspid 1 (1.4%). Mean perfusion time was 45.2 ± 18.3 min for the whole group and 37.2 ± 11.3 min for annuloplasty alone. Mean ischemic time was 28.4 ± 14.3 min and 21.8 ± 7.1 min respectively. Follow-up time ranged from 7 months to 18 years. Mortality was 4.3% (3 cases) in the early postoperative and 8.6% (6 cases) in the late follow up. Early residual regurgitation was found in 15 patients (21.4%) and 50.0% in 35. Thirteen (18.6%) were reoperated at a mean p.o. time of 56.2 ± 46.2 m. Causes for reoperation: primary MR 5 (38.5%), endocarditis 4 (30.7%), stenosis 2 (15.4%), aortic valve disfunction 1 (7.7%), pulmonary embolism 1 (7.7%). Late evaluation in 46 non-operated survivors: 34 were in functional class I (73.9%), 10 in II (21.7%) and 2 in III (4.3%). Actuarial survival was 93 ± 3% at 5 years and 80 ± 7% at 10 years. Event-free survival was 89 ± 4% and 61 ± 10% at 5 and 10 years. For rheumatic ethiology, event-free survival was 80 ± 8% and 55 ± 16% and, for congenital MR, 90 ± 9% at 5 and 10 years p.o. Simple, unsupported annuloplasty (Wooler type), alone or associated to chordal shortening is an effective and reproducible procedure for MR in children and adolescents. Morbidity and mortality are low in relation to other techniques and prosthetic replacement. Failures were mainly related to rheumatic carditis and infective endocarditis. In growing up patient under 18 years old, this technique would be recommended because it may allow unrestricted development of the mitral orifice.
Keywords: Mitral valve insufficiency, surgery; Mitral valve, surgery; Heart surgery, methods; Mitral valve, surgery, child; Mitral valve, surgery, adolescence
In vitro comparative study between bovine pericardial and porcine bioprosthesis
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Most of the cardiac valve implantations in Brazil are represented by bovine pericardial valves, followed by the porcine prostheses. In the evaluation of biological valves, the following should be taken into consideration: hydrodynamic performance resistance to fatigue and calcification process. In this study, the hydrodynamic performance of bovine pericardial bioprostheses (Biopro-BP-Braile Biomedica) was evaluated comparatively to porcine valves (Biopro-PP-Braile Biomedica), through the transvalvular medium gradient. The hydrodynamic tests were made on prostheses varying from 19 to 35 mm in diameter, which underwent the pulse duplicator system Shelhigh (Shelligh Inc.). The ejection volume was constantly kept at 90 ml. The pulse frequencies varied between 60 and 100 cycles per minute, allowing flows between 5 and 9 liters per minute, equivalent to approximate continuos flows of 8 to 18 liters per minute. There was tendency to decrease the gradients, in proportion to increase of the bioprostheses external diameters. The medium pressure gradient found in the bovine pericardial prostheses was significantly smaller than that in the porcine prostheses (p<0.01), for all diameters studied. Respecting the large variability of protocols of tests in the literature for hydrodynamic evaluation of valve prostheses, the necessity of standard tests becomes stronger, seeking adequate comparison among the several valves.
Keywords: Heartvalves prosthesis; Bioprosthesis; Pericardium, cattle; Pericardium, swine; Pericardium; Material testing; Biocompatible materiais
Biplus bileaflet carbon cardiac valve: project and development
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
INTRODUCTION: After the development of carbon cardiac disc valve covered with heterologous pericardium with good clinical results after two years, the authors developed the first brazilian carbon bileaflet valve. The finality was to have a valve with low level of noise, recovered with biological material for improving the annulus valve healing and reduce the exposed synthetic material in blood stream. Linning the valve with biologic material is a tentative to reduce the morbidity and mortality on respect of thrombosis, thromboembolism, reoperations and minor use of anticoagulants to reduce the haemorrhagic events. Some principles were established on hybrid valve: durable mechanical system, points of contact without biologic material, use of biologic material with minor organic reaction, preferential closing system with superposition on a track seat and loose points for accept biologic material limited growth. MATERIAL AND METHODS: The bileaflet valve has horizontal closing with points of articulation in the internal face of valve ring, made of CARBOLITE (hardened polymeric carbon). The valve is made in three models: only in carbon (equal to other valves), one model recovered with biologic material and a model with silicone elastomer track seat recovered with heterologous pericardium, intended to be noiseless, conserved in glycerin. There are two aortic patients with the second model with two and three months of evolution with oral anticoagulations. RESULTS: The cases have a short time of evolution with good results. The model with silicone elastomer track seat is in fatigue test system and does not have any rupture after 30 days, equivalent to 1.4 years of clinic use. CONCLUSIONS: The Biplus valve shows adequate design for receiving the biological material and for work with silicone elastomer track seat alowing a noiseless valve for better patients confort.
Keywords: Heartvalves; Biocompatible materials; Heartvalves prosthesis, instrumentation; Blood vessels prosthesis, instrumentation
Technical modifications in the surgery of supravalvar aortic stenosis
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
A technical modification in the surgery of supravalvar aortic stenosis has been developed since October 1991 to December 1995, without using artificial grafts, but only healthy tissue of the ascending aorta thus permitting a suitable enlargement of the aortic root. The aim of this technique is to avoid complications of re-estenosis of aortic root in the late evolution of patientes submitted to surgical treatment of localized supravalvar aortic stenosis which was provoked by calcification and hardening of prosthetic material used for the enlargement of one or more Valsalva sinuses, with or whitout transversal section of the aorta. Ten patients underwent a surgery in this meantime, with clinical and hemodynamic diagnosis of localized supravalvar aortic stenosis. Their ages varied from 11 months to 38 years (mean = 13.2 years), the weight varied from 7.500 kg to 56 kg (mean = 29.1 kg), and the height varied from 72 cm to 1.68 m (mean = 1.5 m). Six of these patients were male. Three of them were asymptomatic; 4 had dyspnea, 2 were tired at efforts, 2 had palpitations, 1 had paresthesia in the lower limbs, and 1 cyanosis at crying; 6 of them bore Williams syndrome. The systolic gradient between free cavity of left ventricle and aorta varied from 50 to 100 mmHg (mean = 73.5).The patients were operated on with extracorporeal circulation, moderate hypothermia, crystalloid cardioplegia in the 7 first cases and bloody cardioplegia in the 3 last ones. The ascending aorta was widely dissected till the supra-aortic vessels. After the aorta total transection and the resection of the stenosis f ibrotic tissue, longitudinal incisions were performed at the edge of the aortic proximal portion till the bottom of the Valsalva sinuses. Next to it, longitudinal incisions were performed in the distal portion, in the regions corresponding to the comissural points, in such a way that each stretching of the distal aorta may widen a bottom of Valsalva sinus, in this way obtaining an aortic root with an anatomic aspect and regular sizes. Presently, no death has occurred in a post-operative period from 3 months to 4 years and 5 months. All the patients are asymptomatic, having a satisfactory evolution, checked by Doppler Echocardiogram, Magnetic Nuclear Ressonance and Hemodynamic study. These results allow us to conclude that this technique is suitable to the surgical correction of the localized supravalvar aortic stenosis, by the point of not using artificial grafts and accomplishing the aorta suture in a sinusoidal line, avoiding reestenosis.
Keywords: Aortic valve stenosis, surgery; Heart surgery, methods; Postoperative complications
Transxiphoid approach without sternotomy for the correction of atrial septal defect
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
PURPOSE: Evaluate a new access for surgical correction of atrial septal defects. METHODS: The access by xiphoid window was done in 7 cases with atria! septal defect type ostium secundum. The age ranged from 6 months to 14 years, mean-age 5.1 years old. In all cases the extracorporeal circulation was done with femoral artery and right atrial cannulation and aortic clamping. The video-assisted endoscopy was utilized to help the visualization of the aorta, ductus arteriosus and the anatomy of the left intracardiac structures. RESULTS: There was no intraoperative or postoperative complications and in our 7 cases the extubation at the operating room was possible. CONCLUSION: The xiphoid window without opening the sternum permited correction of the atrial septal defect with good results and without complications, and could be used as a new technique, less invasive, to correct these defects.
Keywords: Atrial heart septal defects, surgery; Xiphoid bone; Extracorporeal circulation; Thoracoscopy; Surgery, minimally invasive
Effects of the propofol in the myocardial contractile response to dopamine and dobutamine in isolated rat's heart
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
PURPOSE: Experimental investigation of the pharmacodynamic effects of propofol with and without simultaneous injections of dopamine or dobutamine in isolated hearts of rats. METHODS: In all animals under anaesthesia the hearts were removed and irrigated by a Krebs-Hensleit solution containing O2 (95%) and CO2 (5%), under constant pressure of 90 cm H2O and at 37ºC. After stabilization of the heart activity during 15 minutes, the control values were obtained. The following groups were considered: Group I (control) - 10 hearts perfused only with the Krebs-Hensleit solution during 11 minutes after the control values registration. Group II (dopamine-propofol-dopamine) -10 hearts with the following sequency of drug injections and results values registration: dopamine (50 mcg/ml), 1.3 and 5 minutes registration; propofol (25 mcg/ml), 1 minute period registration; dopamine again in the same dosis, 1.3 and 5 minutes values registration. Group III (dobutamine-propofol-dobutamine) -10 hearts with the following sequency of drug injections and results values registration: dobutamine (50 mcg/ml), 1.3 and 5 minutes registration: propofol (25 mcg/ml), 1 minute period registration; dobutamine again in the same dose and 1.3 and 5 minutes of registration. RESULTS: In Group I hearts, the dT/dt mean values changed only from 39.57 ± 3.97 to 39.37 ± 3.44 g.seg-1 (p>0.05). In Group II after propofol and dopamine the dT/dt fell 17.61 % (p<0.05) in the 1 min; 8.37% (p<0.05) in the 3 rd min and 10.84% (p<0.05) in 5 th min, when compared with the results from isolated dopamine injections. In Group III the dT/dt increased 6.16% (p>0.050) in the 1 st min; 3.62% (p<0.05) in 3 rd min and 3.08% (p>0.05) in the 5 th min, over the values from isolated dobutamine injections. CONCLUSIONS: The myocardial contractile response to dopamine (50 mcg-ml-1) was partially inhibited; by propofol (25 mcg/ml-1) action was not altered.
Keywords: Myocardial contraction, drug effects; Propofol, pharmacology; Dopamine, pharmacology; Dobutamine, pharmacology; Rats, experimental studies
Bovine tail artery as an alternative vascular graft: experimental study in dogs. (Preliminary report)
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
Twenty segments of bovine tail artery treated with glutaraldehyde were interposed into 10 dog's femoral arteries. The post-operative period varied from 183 to 297 days. Motor function, pulses, systolic, diastolic and median blood pressure and blood flow throught the graft, as well as consistence, dilatation and color in the follow-up period were analysed. There were no deaths, motorfunction or inflammatory changes. There were 15% of total thrombosis, focal wall thrombosis (30%), advential focal linfoplasmocitory reaction (100%), myocells calcification (15%), total reendotelization (60%) and partial (30%). Our data show that bovine tail artery has a diameter adequacy with small arteries, is long enough to replace or reach several distal arterial segments, has easy epitelization, and absence of cytological reation, allowding its use as an alternative graft.
Keywords: Femoral artery, surgery; Bioprosthesis, methods; Biocompatible materials
CASE REPORT
Use of compound grafts in minimally invasive coronary artery bypass graft
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
This paper reports our experience with the use of compound grafts in minimally invasive coronary artery bypass graft (MICABG). An alternative for MICABG is the use of compound grafts in cases where several coronary branches are to be revascularized, when internal mammary artery is demonstrated to be short, or branches off early. One female patient, 54 years old, with a lesion of 90% in the third proximal part of the left descending artery (LAD), was operated upon, submitted to MICABG by left rainithoracotomy. The left internal mammary artery (LIMA) was amply dissected by the use of a long electrocautery, with the help of a videothoracoscope, and a clip for ligation of the intercostal branches. Following the sectioning of the LIMA, there was absence of blood flow and technical problems at the distal third. This compromised segment was disposed off and the LIMA was lengthened using the interpositioning of a saphenous vein segment, making possible the anastomosis with the LAD. Surgery was three hours long and the patient extubated fours hours postoperatively; the left pleural drainage tube was removed on the third day. Patient follow-up was satisfactory, without clinical problems; patient left the hospital in the fifth postoperative day. Postoperative cineangiocoronariography showed anastomosis patency; echodopplercardiogram performed on the fourth postoperative month showed patency and high resistence flow. In conclusion, the use of compound grafts for MICABG showed to be an efficient alternative to amplify the extension of the LIMA, enabling anastomosis when this artery is short or presents flow problems, or even if there is intention of treating more than one coronary artery.
Keywords: Myocardial revascularization, methods; Thoracic arteries, surgery; Coronary vessels, surgery; Thoracoscopy; Surgery, minimally invasive
Aneurysm in the saphenous vein bypass graft to the left marginal coronary artery, broked up to the left bronchus
Braz J Cardiovasc Surg 11;
Publish in: 8/1/2025
A patient who suffered two previous myocardium revascularization surgeries, ten and twenty years ago, respectively, showed a history of dyspnea, chest pain and hemoptysis suddenly. In the folllowing examinations, a big saphenous vein bypass graft aneurysm was observed to the left marginal artery, partially broked up in the left bronchus. The aneurysm was corrected sucessfully, but the patient died 15 days after the surgery due to a pulmonary infection.
Keywords: Aneurysm, surgery; Ruptured aneurysm, surgery; Saphenous vein, surgery; Saphenous vein bypass; Coronary artery surgery; Coronary artery bypass