Internal thoracic artery: sternal branches and their importance in thoracic surgery

In surgical myocardial revascularization using both ITAs occurs a decrease in blood supply to the sternum andit is one of the causes of postoperative mediastinitis. Our study focused the sternal branches, from these ITAs,which are responsible for maintaining blood supply of the sternum after bilateral use of internal thoracic arteryin myocardial revascularization. 60 internal faces of the anterior chest wall were dissected and formaldehydepreserved. The study consisted of 28 females and 32 males, the trunks and their branches were measuredand photographed and statistical tests were applied. The most dissected sternal trunks found in 120 internalthoracic artery were the intercostal/sternal and the perforating/sternal. The preservation of these trunks isneeded to prevent any disorder of the sternum.

Pleural opening impairs respiratory system compliance and resistance in off-pump coronary artery bypass grafting.

AIM: This study evaluated the effect of pleurotomy on respiratory system compliance and resistance in off-pump coronary artery bypass (OPCAB) using the left internal thoracic artery (LITA). METHODS: Thirty-two patients were prospectively allocated into two groups: OP group (n = 16 patients with open left pleural cavity); IP group (N.=16 patients with intact pleural cavity). Static and dynamic lung compliance and total respiratory system resistance calculation were recorded at anesthesia induction (before chest opening) and immediately after chest closure. RESULTS: Static lung compliance values significantly decreased after chest closure in both groups (P < 0.0001), but the OP group had a significantly greater decline (P = 0.0007). Dynamic lung compliance decreased in either groups after chest closure (P < 0.0001), however, no significant difference was found between groups (P = 0.228). Total respiratory system resistance increased in both groups (P < 0.05), however the OP group had a higher increase (P = 0.0005). Orotracheal intubation time (P = 0.041) and hospital stay (P = 0.0004) were higher in the OP group. CONCLUSION: Pleura opening and need of chest tube insertion induced significant reduction in static lung compliance and increase in total respiratory system resistance, furthermore contributing to impair pulmonary dysfunction in the early postoperative period after OPCAB.

Cytokines and pediatric open heart surgery with cardiopulmonary bypass.

It is well known that, subsequent to cardiopulmonary bypass, and particularly in children, an inflammatory response within the body can often result in a characteristic syndrome. Recently, it has been suggested that this phenomenon is due to a systemic inflammatory response, with significant involvement of cytokines. With this in mind, we investigated the behavior of tumour necrosis factor-alpha and interleukin-6 during the operative and in the immediate postoperative period in a group of children submitted to open heart surgery. We investigated any possible relation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, with the serum levels of lactate, and with the extent of use of inotropic drugs in postoperative period. The cytokines were measured in samples withdrawn after induction of anesthesia, after 10 minutes of cardiopulmonary bypass, after re-establishment of circulation, and then 2 and 24 hours after the end of cardiopulmonary bypass. The levels of tumour necrosis factor-alpha and interleukin-6 increased between the beginning and at two hours of the end of cardiopulmonary bypass. There was no correlation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, although there was a positive relation between levels of interleukin-6 and lactate in samples withdrawn at two hours of the end of bypass, and the measured levels of the cytokines correlated with the extent of inotropic drugs employed in the 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.

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.

Inflammatory response after myocardial revascularization with or without cardiopulmonary bypass.

BACKGROUND: Tumor necrosis factor-alpha has been implicated in complications seen after cardiac operations with cardiopulmonary bypass. The release of tumor necrosis factor-alpha and its possible effects were studied in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass. METHODS: Twenty patients were studied, 10 with (group 1) and 10 without cardiopulmonary bypass (group 2). Serial blood samples were obtained before, during, and up to 48 hours after operation. Circulating tumor necrosis factor-alpha levels, leukocyte counts, and erythrocyte sedimentation rates were measured. Hemodynamic variables (blood pressure and heart rate), temperature, orotracheal intubation time, postoperative bleeding, and inotropic drug requirements were compared. RESULTS: Serum levels of tumor necrosis factor-alpha were detected in 6 patients (60%) in group 1 and none in group 2. The patients in group 1 had more hypotension than those in group 2 (7.4 +/- 1.0 mm Hg versus 8.5 +/- 0.7 mm Hg), required more inotropic drugs (8 patients versus 1 patient), and had a higher heart rate (114 +/- 8 beats per minute versus 98 +/- 10 beats per minute), a higher temperature (37.1 degrees +/- 0.5 degrees C versus 36.6 degrees +/- 0.3 degrees C), increased postoperative bleeding (820 +/- 120 mL versus 360 +/- 84 mL), a longer orotracheal intubation time (13.6 +/- 2.2 hours versus 9.3 +/- 1.4 hours), and a more pronounced leukocytosis. CONCLUSIONS: Cardiopulmonary bypass induces the whole-body inflammatory response through the release of tumor necrosis factor alpha, resulting in adverse systemic effects.

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.

Surgical anatomy of the internal thoracic artery.

BACKGROUND: The internal thoracic artery (ITA) has become increasingly important in coronary artery bypass grafting due to the excellent long-term results. This study reviews its anatomic characteristics. METHODS: The ITAs of 100 cadavers were examined and their origin, relation to the phrenic nerve, presence of lateral costal branch; origin of pericardiacophrenic arteries, length, level and type of ITA termination, relation with the transverse muscle of thorax, collateral parietal branches, and distance between the ITA and sternal margins were studied. RESULTS: The ITA was present in all cases, originating directly from the subclavian artery or from a common trunk with other arteries. Its length was 20.4 cm on average, and the most frequent level of termination was at the sixth intercostal space, existing as a bifurcation in 93% and as a trifurcation in 7%. The pericardiacophrenic artery originated from the ITA in 89%. The lateral costal branch was present in 15% of the cases. The ITA was covered by the transverse muscle of the thorax for 7.5 cm (average) and was crossed anteriorly by the phrenic nerve in 70.0%. CONCLUSIONS: Information provided by this study may contribute to knowledge of its anatomic characteristics and in turn help prevent complications in ITA dissections.

[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.

Coronary artery bypass grafting without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting without cardiopulmonary bypass is now an accepted technique of myocardial revascularization. We herein report our total experience with this procedure. METHODS: In a consecutive series of 8,751 patients operated on in our institution for coronary artery disease from 1981 to 1994, 1,274 patients received coronary artery bypass grafting without cardiopulmonary bypass. RESULTS: Results indicate that the operation can be performed with an acceptable mortality (2.5%), and that all types of arterial conduits can be used. Most commonly the left anterior descending and right coronary arteries were bypassed. The incidence of arrhythmias and of pulmonary and neurologic complications were significantly lower in this group of patients compared with patients receiving coronary artery bypass grafting with cardiopulmonary bypass. Most importantly, there was decreased cost when the procedure was used because no extracorporeal circulation, cardioplegia sets, or other cannulas were used. CONCLUSIONS: We conclude that the continuing use of coronary artery bypass grafting without cardiopulmonary bypass is justified and that, with proper selection of patients, the procedure is safe and cost-effective.

[Heart surgery with extracorporeal circulation in pregnant women. Analysis of materno-fetal outcome]. / Cirurgia cardíaca com circulação extracorpórea em gestantes. Análise da evolução materno-fetal.

PURPOSE: To analyze maternal and fetal outcome in pregnant undergone to cardiac surgery. METHODS: We studied the evolution of 30 pregnant women submitted to cardiac surgery at the Hospital São Paulo, between Jan/81 and Dec/92 and, further, attended at this Hospital till the parturition. The following variables were analyzed: cardiopulmonary bypass, time of the procedure and time of the anoxia, patient temperature, surgical complications, and neonatal, maternal and fetal outcomes. RESULTS: All patients had rheumatic heart disease and, in 17, mitral stenosis was the main anatomic abnormality. Mitral commissurotomy was performed in 24 patients, double comissurotomy (mitral and aortic) in 1 patient and valve replacement was performed in 5. Cardiopulmonary bypass was utilized in all procedure; occurrence of surgical complications (p < 0.001) and the prolonged surgical time (p = 0.009) were related to the fetal mortality. There was 4 (13.3%) maternal deaths and 10 (33.3%) fetal deaths related to the surgery. CONCLUSION: The indication of cardiac surgery in pregnant women is heart failure, refractory to conventional therapy; cardiopulmonary bypass is associated with high fetal mortality.

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.

[Prolonged respiratory support with extracorporeal membrane oxygenation in lung transplantation]. / Suporte respiratório prolongado com oxigenador de membrana extracorpóreo em transplante pulmonar.

A 42 year-old woman with terminal chronic lung disease underwent to left lung transplantation. Extracorporeal membrane oxigenation (ECMO) was required because dysfunction of transplanted organ occurred and was non-responsive to conventional therapy. The time of assistance was 47 hours and after this, the dysfunction of the transplanted lung reversed and the patient was weaned from the oxigenator. During hospital stay, she developed sepsis and died. In conclusion, ECMO was decisive to the treatment of pulmonary dysfunction, allowing time to the resolution of lung lesion.

[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.

[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.

[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.