Surgical treatment of acute type B aortic dissection using an endoprosthesis (elephant trunk).

BACKGROUND: The surgical treatment of acute complicated type B aortic dissection continues to be a challenge and is still associated with high morbidity and mortality rates. METHODS: Seventy consecutive patients with an acute type B aortic dissection underwent an elephant trunk procedure through a median sternotomy during deep hypothermic circulatory arrest. An endoprosthesis that was 22 to 24 mm in diameter was inserted through an incision in the arch and held in place with only proximal sutures. RESULTS: The mean arrest time was 31.4 +/- 8.7 minutes, and it was possible to adequately position the endoluminal graft in every patient. The procedure was done in association with other procedures in 13 patients. There were six in-hospital deaths not related to the endoprosthesis, and four late deaths. Late reoperation was necessary in 6 patients to manage leakage at the proximal suture line. CONCLUSIONS: The insertion of an endoprosthesis through the arch for the management of a complicated acute type B dissection has several advantages over the conventional thoracotomy approach. The hospital mortality rate in this series of 70 patients was 20%, and the actuarial 5-year survival rate was 62.5%. We consider the elephant trunk procedure the treatment of choice in patients with type B acute dissections, regardless of whether the dissection is complicated or not.

Successful use of deep hypothermic circulatory arrest in pregnancy.

A woman pregnant for 21 weeks underwent an emergency operation because of an aortic arch aneurysm that had ruptured into her left lung. Cardiopulmonary bypass and deep hypothermia were used and she needed 37 minutes of circulatory arrest at a core temperature of 19 degrees C. Both the mother and fetus survived, and a normal baby was delivered by cesarean section at the 39th week of gestation.

Endoscopic placement of stents in aneurysms of the descending thoracic aorta.

This is a case of a patient with two saccular aneurysms in the descending aorta. Two self-expanding stents were inserted through an opening in the aortic arch, guided by the use of an Olympus endoscope, under profound hypothermia and total circulatory arrest. The bloodless field made possible the identification of the main thoracic branches, facilitating the positioning and deployment of both stents. Immediate postoperative recovery was excellent.

Replacement of infected thoracic aortic prosthesis with a spiral composite vein graft.

We describe a case of a patient who had a ruptured aorta repaired by femorofemoral bypass with an interposition graft and subsequently had a graft infection. The patient was taken to operation and the old graft was removed. It was replaced by a spiral great saphenous vein graft. The patient has been followed up for 36 months with computed tomographic scanning, which has shown that the vein graft has not dilated.

Surgical retrieval of undeployed intracoronary stent without cardiopulmonary bypass.

Intracoronary stenting has now become a widely established method for treatment of complications of coronary angioplasty. The risk of stent embolism exists and if not retrieved, it may lead to thrombosis and coronary occlusion with myocardial infarction. We report a case of embolism of an undeployed intracoronary stent where there was failure of percutaneous attempts to pull back the stent, requiring surgical retrieval and simultaneous coronary artery bypass grafting, both without cardiopulmonary bypass.

Mitral valve replacement with glutaraldehyde preserved aortic allografts.

OBJECTIVE: To present long-term results after mitral valve replacement with stent mounted glutaraldehyde preserved aortic allografts in patients older than 15 years. The clinical support for this study was to combine the glutaraldehyde technique of biological tissue preservation with the advantages of allografts when compared to xenografts. This was demonstrated in previous studies using other methods of tissue processing. METHODS: Between September 1984 and November 1994, 70 patients aged 16-77 years (mean 35.4 years) underwent mitral valve replacement with this preserved and mounted allograft. Of these, 40 patients (57.2%) were aged 16-35 years and 15 (21.4%) were 20 years old or younger; 46 (65.7%) were females and 24 (34.3%) males. Single mitral valve replacement was performed in 60 patients and 10 were also subjected to other combined cardiac procedures. Human aortic valves were obtained during routine autopsy, processed in glutaraldehyde and mounted into flexible stents, using the same technique as that used for porcine bioprostheses. RESULTS: Hospital mortality was 1.4%. Total follow-up was 543.1 patient-years, corresponding to a mean follow-up of 7.9 years per patient. Echocardiography demonstrated a hemodynamic performance similar to porcine bioprostheses. Late mortality was 0.7 +/- 0.6% per patient-year and the causes were congestive heart failure in 2, prosthetic endocarditis in 1 and acute myocardial infarction in 1. The 12-year actuarial survival was 92.4 +/- 3.2%. The incidence of late complications was 5.2 +/- 1.2% per patient-year, including congestive heart failure, prosthetic endocarditis, periprosthetic leak, thromboembolic episodes, recurrence of rheumatic disease, coronary artery disease and allograft failure. Complications related to heart disease represented 2.8 +/- 0.6% and allobioprosthesis-related 2.4 +/- 0.5% per patient-year. The 12-year actuarial freedom from primary valve failure was 81.0 +/- 15.0%. The incidence of reoperations was 1.5 +/- 0.8% per patient-year and the main indication was prosthetic endocarditis. Other causes were periprosthetic leak, aortic insufficiency in the native aortic valve and allobioprosthesis dysfunction. Functional results demonstrated a significant improvement in patients clinical condition. CONCLUSION: This 12-year follow-up shows a very low incidence of primary allograft failure for patients older than 15 years undergoing mitral valve replacement, and much superior than our results with porcine bioprosthesis in the same age group. This supports our assumption that this investigational valve represents a new advance in cardiac valve surgery.

Vasoplegic syndrome after open heart surgery.

BACKGROUND: A new form of postperfusion manifestation is detailed, a vasoplegic syndrome presenting in the postoperative period after cardiopulmonary bypass (CPB) heart surgery. METHODS: This retrospective study included sixteen patients who underwent cardiovascular surgery using CPB and exhibited clinical and hemodynamic features compatible with vasoplegic syndrome. The technique of CPB was hypothermic (28 degrees C) in 15 and normothermic in 1 patient, and hypothermic blood cardioplegia was employed in all patients, except 1. The mean CPB time was 121 minutes, ranging from 80 to 210 minutes. RESULTS: The patients presented a severe feature comprising hypotension, tachycardia, normal or elevated cardiac output, low systemic vascular resistance and decreased filling pressures. Fluid administration alone was not capable of restoring hemodynamic parameters. Physical examination revealed normal capillary filling at the extremities although oliguria and hypotension were observed. These patients needed a high dosage of vasoconstrictor drugs (norepinephrine) for blood pressure control but even high dose norepinephrine did not produce the classical situation of cool extremities and weak peripheral pulses, with increased morbidity and mortality. Severe systemic complications could develop if the vasoplegic syndrome persisted 36-48 hours after its onset. All patients, except 3, presented associated postoperative complications and 4 patients died. The characteristics of vasoplegic syndrome are similar to those observed in septic shock, where the alterations are mediated by cytokines and tumor necrosis factor-alpha. CONCLUSIONS: The appearance of vasoplegic syndrome augmented operative morbidity with a consequent increased risk to the patient in the early postoperative period.

Video-endoscopic dissection of multiple pedicled arterial grafts for use in minimally invasive coronary artery bypass surgery.

BACKGROUND: We evaluated the possibility of video-endoscopic dissection of both internal thoracic arteries (rTAs) through the left thoracic approach and right gastroepiploic artery (GEA) via a small laparoscopic access, for use in minimally invasive coronary artery bypass surgery. METHODS: The procedure was performed on twenty-two mongrel dogs. Three 10 mm ports were inserted in the left hemithorax to enable the introduction of a rigid 0-degree videoscope and forceps which allowed access to the left and right ITAs. For dissection of the GEA, one 10 mm and two 5 mm ports were inserted in the para-umbilical region. RESULTS: The left and right ITAs and the GEA were easily visualized and dissection and complete mobilization was achieved without injury, which was checked by the presence of good blood flow. The ITAs and GEA were divided distally, exteriorized through a small left anterior thoracotomy and the length of these three grafts were able to reach all of the left coronary artery branches. CONCLUSIONS: We have demonstrated, in dogs, the feasibility of video-assisted dissection of both the left and right ITAs through the left thoracic approach, without sternotomy, avoiding the risks of sternal complications and expanding its use for all patients. Furthermore, a third arterial conduit (the RGA) can be used without requiring laparotomy.

[Hypothermic retrograde cerebral perfusion for treatment of air embolism during extracorporeal circulation]. / Perfusão cerebral retrógrada hipotérmica para tratamento de embolia gasosa durante circulação extracorpórea.

Air embolism during extracorporeal circulation is a life-threatening complication, requiring immediate response. During a recent case, brain damage was avoided using hypothermic retrograde cerebral perfusion, connecting the arterial line to superior vena cava cannula. Perfusion lasted 5 minutes at flow of 200ml/min. The patient had complete recovery and was discharged with normal neurologic status. The technique employed is described and steps for a face this accident are proposed.

[Heart surgery in Brazilian Indians]. / Cirurgia cardíaca em índios brasileiros.

PURPOSE: Our experience with surgical treatment of heart diseases in Indians living in the Amazon rain forest in primitive stages was reviewed. METHODS: From 1988 to 1995, 18 patients underwent cardiovascular surgical procedures at the São Paulo Hospital of the Escola Paulista de Medicina. Seven patients had valvar disease, nine congenital heart defects, one submitral aneurysm and one arrhythmia. Thirteen Indians came from tribes of the Amazon rain forest area: three from the Xavante, two from Waiapi, two from Tucano, two from Macuxi, two from Mayoruna, and one of each tribe of Xikrin, Guajajara, Terena, Surui, Galibi, Cinta-Larga and Pataxó. RESULTS: We performed 22 operations, with two hospital deaths. Follow-up was possible in 87.5% of cases, with one late death. The majority of cases were due to congenital heart defects and in this series it was noted the absence of operations to treat coronary artery disease. The incidence of valve disease was higher in accultured or semi-accultured Indians. CONCLUSION: The surgical treatment of cardiovascular disease has made possible to the surviving indians to return to and be accepted by their fellow tribesmen.

[Myocardial revascularization without extracorporeal circulation. Surgical results in 1090 patients]. / Revascularização miocárdica sem circulação extracorpórea. Resultados cirúrgicos em 1090 pacientes.

PURPOSE: To report our experience of 12 years of myocardial revascularization without cardiopulmonary bypass (CPB) and to discuss its expanding surgical indications. METHODS: This technique was employed in 1090 patients, between September/81 and April/93, corresponding to 17.4% of all revascularized patients. Regarding gender, male patients were the majority (73.7%) and ages ranged from 28 to 86 year-old (mean 57). Chronic coronary insufficiency was the main indication (69.4%) and 18.9% of our global experience were operated on during acute ischemia. The average number of grafts per patient was 1.6 and internal mammary artery was utilized in 60.1% of patients. Left anterior descending coronary artery and right coronary artery were the coronary arteries most often treated. RESULTS: Our hospital mortality rate was 2.5% (28/1090) although it was 7% for patients over 70 years. The most common cause of death was cardiogenic shock after failed angioplasty. Postoperative complications included AMI in 4.8%, arrhythmias in 5.5% and pulmonary in 3.2%. Mean of any type of blood derivate utilization was 0.28 units/patients. CONCLUSION: Myocardial revascularization without CPB is a valid alternative in a selected cohort of patients and it is performed with low morbidity and mortality. Nowadays it represents an excellent tactical option for high-risk patients and in failed angioplasties.

[An unusual indication of deep hypothermia with total circulatory arrest for myocardial revascularization surgery]. / Uma indicação incomum da hipotermia profunda com parada circulatória total para cirurgia de revascularização miocárdica.

The authors relate a case of 69 years old patient with unstable angina and left main coronary artery disease, who underwent aggressive mediastinal radiotherapy for lymphoproliferative syndrome 20 years ago and who needed urgent myocardial revascularization. Due to great calcification and heavily heart adherences it was performed 20 degrees C deep hypothermic circulatory arrest to avoid aortic clamping and to make the anastomosis with better exposition of the aorta and coronary arteries.

[Artificial respiration with extracorporeal membrane oxygenator in arteriovenous position without pump. Experimental study]. / Respiração artificial com oxigenador de membrana extracorpóreo em posição artério-venosa sem bomba. Estudo experimental.

PURPOSE: To test the hypothesis of respiratory support and to study the consequent hemodynamic alterations, we performed pumpless A-V ECMO using a 1.2m2 polipropylene hollow fiber membrane oxygenator, specially adapted from conventional model utilized in routine cardiac surgery. METHODS: Two canine groups of six dogs each were studied. Group 1 had normal lungs and group 2 acute respiratory failure induced by 0.035ml/kg intravenous oleic acid. The dogs were anesthetized and maintained in apnea with curare. Heparin was given in a single dose of 400U/kg. Gasimetric and hemodynamic parameters were monitored each 30 minutes during a 3 hour period. Then the oxygenator was discontinued and after 15 minutes a final arterial blood gas sample was taken for analysis. RESULTS: Blood samples at 3 hours have shown a mean PaO2 of 260.6mmHg in group 1 and 114.4mmHg in group 2 and PaCO2 of 54.3 and 56.2mmHg, respectively. After the oxygenator was discontinued PaCO2 levels increased to 161.6 and 193.7mmHg, respectively. The hemodynamic parameters shown few alterations. CONCLUSION: In both groups pumpless A-V ECMO was able to maintain gasimetric parameters within acceptable patterns and compatible with life, with few hemodynamic alterations. However, an adequate mean arterial blood pressure is needed to provide flow through membrane oxygenator.

Dissecçöes aórticas agudas: abordagem clínica e cirúrgica / Acute aortic dissections: clinical and surgical approach

As dissecçöes agudas da aorta representam uma entidade clínica não rara e de extrema gravidade. O diagnóstico precoce pode ser realizado e, para tanto, é necessário alto grau de suspeita clínica, que irá direcionar os exames a serem realizados com presteza, levando sempre em consideração a experiência da instituição com diversos exames complementares. Recomenda-se a utilização do método diagnóstico de maior acurácia e que proporcione menor estresse ao paciente. Assim que for levantada suspeita clínica de dissecção da aorta, deve ser instituída terapêutica clínica. Com a confirmação diagnóstica de diassecção envolvendo a aorta ascendente, é mandatório o tratamento cirúrgico imediato. Nos casos de dissecção da aorta descendente, o tratamento clínico é o de escolha, a menos que haja indícios de complicaçöes decorrentes da dissecção, Recentemente, novas perspectivas terapêuticas têm sido desenvolvidas e testadas com resultados bastante promissores, entre as quais destacam-se a técnica cirúrgica a tromba de elefante e o tratamento com prótese endovascular ("stent"), pela via percutânea, para correçäo das dissecçöes da aorta descendente.