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Biomedical subjects

L E Leão

Publications and source records attributed to L E Leão.

At least 19 recordsLinked to original sources
PubMed2000

Useful prognostic panel markers to express the biological tumor status in resected lung adenocarcinomas.

BACKGROUND: Tumor stage and its histological subtype remain the most important predictors of clinical behavior in current pulmonary practice of lung cancer. However, many investigators agree that these parameters are not sufficient to predict which tumor will recur, even after radical curative surgery. Therefore, it is necessary to evaluate the significance of other morphological, biological and molecular parameters beyond TNM classification. METHODS: Pathological specimens were collected from 45 patients after resection for stage IA (five), stage IB (10), stage IIB (10), stage IIIA (14) and stage IV (six) lung adenocarcinomas. A panel of two morphological (proportion of stroma within the tumor and degree of tumor differentiation), two biological [DNA ploidy and argyrophilic nucleolar organizer region (AgNOR)] and three molecular (immunohistochemical expression of Ki-67, p53 and bcl-2) markers was chosen for analysis of the primary tumor. Life Tables for Survival were used to analyze the individual impact of each variable on survival. Cox proportional hazards model analysis was used to construct an independent tumor status model for cancer recurrence and death. Chi-squared analyses were used to determine the statistically significant relationship among all the variables present in the study. RESULTS: Multivariate analysis demonstrated statistically significant risk for the following markers: AgNOR, p53 and bcl-2, controlled for stages and surgical resection. CONCLUSIONS: The immunohistochemical expression of p53 and bcl-2 oncogenes and the expression of AgNOR cell proliferation index are critical values in the progression of lung adenocarcinomas. They can express the biological tumor status and indicate a more accurate prognosis.

Adenocarcinoma↗
PubMed2000

Arterial wall damage caused by snaring of the coronary arteries during off-pump revascularization.

BACKGROUND: Anastomosis of a saphenous or mammary artery conduit to the coronary artery requires precise and reproducible microsurgical technique. Over the past 3 decades, the elective induction of cardiac arrest and circulatory support have provided the conditions suitable for microsurgical anastomosis to all coronary vessels. Beating heart coronary grafting was rejuvenated at our center in 1985 as an alternative to cardiopulmonary bypass and cardioplegic arrest. One of the requirements for off-pump grafting is local vascular control of the target vessel and prevention of bleeding into the field from the open coronary artery. The most common hemostasis technique in use today is the application of circumferential traction sutures and snares around the coronary artery. We performed a human cadaver study to evaluate the potential for local trauma to the native coronary artery caused by this method of hemostasis. METHODS: Our research team applied both 5-0 polypropylene and 2-0 polyester snares to the proximal and distal right coronary artery (RCA) and left anterior descending (LAD) in 25 isolated fresh human cadaver hearts. A total of 100 points of snare application to the native coronary vessels were induced and then investigated histologically, with hematoxylin-eosin, Weigert, and phosphotungstic hematoxylin staining. RESULTS: The results suggested a direct relationship between the severity of the arterial lesion induced by the snares and the degree of local atherosclerotic disease in the native coronary artery. Compression and buckling of the elastic lamellae with medial fractures (similar in nature to angioplasty but directed inward) were seen when snares were applied to a region with marked atherosclerotic disease. CONCLUSIONS: The application of snares to the coronary artery proximal and distal to the anastomotic site must be done with caution. In cases of marked atherosclerotic disease in the underlying coronary artery, a new intimal-medial lesion can occur with indiscriminate application of a tourniquet. This phenomenon may account for some of the reported cases of late peri-anastomotic or distal stenoses seen with off-pump coronary artery bypass grafting and significantly detract from the advantages offered by beating heart surgery. If one or both snares can be avoided entirely, or applied carefully to disease-free segments of the vessel, this problem may be avoided entirely.

Adult↗
PubMed1998

Economic longitudinal lateral posterior thoracothomy. Minimally invasive option in pulmonary resections.

BACKGROUND: Pulmonary resections are usually performed through posterolateral thoracotomy. However this approach has been associated largely with early and late incidence of postoperative morbidity. Several lateral chest approaches have been reported in the medical literature with the objective to decrease morbidity due to thoracotomy. The aim of this study was to evaluate the results of pulmonary resection, performed by means of a minor thoracotomy in the posterior axillary region. METHODS: The skin incision was longitudinal and scapular; shoulder and chest wall muscles were not cut, a subperiosteally lateral portion of rib was removed and the thoracic wall was opened in the rib bed. The approach in this place allowed a smaller skin incision, skin flaps were not necessary and the chest wall opening stayed in a better position in relation to the pulmonary hilum, facilitating the exposition of its anterior and posterior faces. From January 1994 to December 1996 seventy-eight consecutively non-selected patients underwent eighty surgical procedures for several kinds of pulmonary resections. RESULTS: All surgical procedures occurred without difficulties and with a lower number of postoperative complications. A very good aesthetic result was reached. CONCLUSIONS: We believe this chest approach may be a good choice for pulmonary resection.

Adolescent↗
PubMed1996

Transaortic approach has a role in the surgical treatment of ventricular septal defects.

A transaortic approach was used for surgical closure of ventricular septal defects (VSDs), sometimes as first choice and otherwise as an alternative approach. This paper presents the experience in a group of 124 patients who underwent VSD closure by a transaortic approach in an 18-year-period, between 1974 and 1992. Patients were divided in three groups: (I) Isolated VSD, 89 patients (mean age 7.6 years); (II) VSD associated with other malformations, 27 patients (mean age 10.8 years); and (III) recurrent VSD, eight patients (mean age 15.6 years). Two deaths occurred in the postoperative period (2/124), one after closure of VSD in a patient with severe pulmonary hypertension; another death was observed after transaortic closure of the VSD as part of the repair of a complex heart malformation. There were no instances of new right bundle branch block (RBBB) in the group operated on for isolated VSDs. Three cases of left bundle branch block (LBBB) (3.4%) occurred in the isolated VSD group. There were no cases of complete aortic valve (AV) block in the whole series and no instances of AV dysfunction. The transaortic approach is an alternative for the surgical treatment of ventricular septal defects. The ease of exposure and closure of defects suggest this technique to be a particularly attractive approach in the treatment of small to moderate-sized VSDs and also in recurrent VSDs.

Adolescent↗
PubMed1993

[Submitral left ventricular aneurysm in a Brazilian Indian].

Subvalvar left ventricular aneurysm is a rare disease of unknown etiology, that has been described most often in black Africans. A case of Brazilian indian with heart failure and a murmur of mitral regurgitation is reported. The chest x-ray showed a mild bulge in the left cardiac border and two-dimensional echocardiography demonstrated submitral left ventricular aneurysm, confirmed by left ventricular angiography. Surgical treatment consisted of resection of the aneurysm and mitral valvuloplasty. A perforation of the aneurysm, undetected neither by two-dimensional echocardiography nor by angiography was found at surgery.

Adult↗
PubMed1993

[Assessment of pulmonary arterial pressure in adults with Doppler echocardiography].

PURPOSE: To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. PATIENTS AND METHODS: Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. RESULTS: An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p < 0.05) in patients with severe PH (mean PAP > or = 40 mmHg), comparing with patients with PAP < 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p < 0.05) excluding patients with atrial fibrillation (19 cases). CONCLUSION: PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

Adolescent↗
PubMed1992

[Early and late results of myocardial revascularization after coronary thrombolysis with intravenous streptokinase in the treatment of acute myocardial infarction].

PURPOSE: To study the early and late results of patients treated initially intravenous streptokinase and then with coronary artery bypass surgery. METHODS: One hundred and twenty one patients with acute myocardial infarction less than 6 hours duration were treated initially with intravenous streptokinase, and 1-38 days after (median 8.80 days) coronary artery bypass was undertaken. Ninety six patients were operated with extracorporeal circulation and 25 without it. RESULTS: Overall operative mortality was 3.30% (4/121). Reoperations due to bleeding was necessary in 3.30% (4/121). Late mortality was 5.40% with survival probability of 94.60% after 36 months and 92.30% after 70 months. Late morbidity events in terms of angina and cardiac insufficiency demonstrated that 7 patients had angina, 4 cardiac insufficiency and two angina and cardiac insufficiency; probability to be free from these events was 88.20% after 46 months and 66.40% after 70 months. CONCLUSION: Coronary artery bypass surgery after intravenous streptokinase can be undertaken with security and excellent early and late results.

Adult↗
PubMed1991

[Pulmonary artery pressure evaluation in adults by Doppler echocardiography].

PURPOSE: To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. PATIENTS AND METHODS: Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. RESULTS: An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p less than 0.05) in patients with severe PH (mean PAP greater than or equal to 40 mmHg), comparing with patients with PAP less than 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p less than 0.05) excluding patients with atrial fibrilation (19 cases). CONCLUSION: PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

Adolescent↗
PubMed1991

[Systemic-pulmonary shunts in congenital heart diseases with decreased pulmonary blood flow: critical analysis of the surgical techniques and immediate results].

PURPOSE: To evaluate immediate postoperative results in children with congenital heart disease and decreased pulmonary blood flow who underwent a systemic to pulmonary shunt. PATIENTS AND METHODS: Sixty-four patients underwent surgery, 46.8% (30) of them males with ages from 1 day to 17 years old. They were divided in three groups: I--13 pts (20.3%) who underwent classical Blalock-Taussig (BT) shunt; II--46 pts (71.8%) who underwent modified BT shunts, 34 of them with polytetrafluoroetylene (PTFE) and 12 of them with umbilical vein shunts; III--5 pts (7.8%) with central anastomosis that were made with three different types of graft; 3 PTFE, umbilical vein and bovine mammary artery in one each. The simultaneous procedures were: section and suture of PDA--2, closure of systemic-pulmonary collaterals--3, pulmonary valvotomy--3, right ventricular outflow patch--3, pulmonary branch stenosis (enlargement)--2. RESULTS: In group I there were 4 (30.7%) closures, with two immediate reoperation and a total mortality of 30.7%. In group II there were 4 closures (8.6%) and two reoperations with a mortality of 15.2% (7 cases). In group III there was one graft closure and an overall mortality of 80% (4 pts). When analysing deaths due to the shunt itself the mortality rate was respectively 15.3%, 8.6% and 40.0%. CONCLUSION: Modified BT operation was performed most frequently in our service; it was associated with less closure and mortality than the other types of shunt. It is considered our first alternative for a systemic-pulmonary shunt.

Adolescent↗
PubMed1985

Direct myocardial revascularization without cardiopulmonary bypass.

The authors present their experience with 160 patients who underwent coronary artery saphenous vein bypass revascularization without cardiopulmonary bypass. The distal sutures were performed with interruption of the coronary flow without any devices for perfusion of the coronary artery: the proximal sutures were made with tangential clamping of the aorta. Vessels most frequently revascularized were the anterior descending and the distal right coronary artery. Out of 597 patients who underwent bypass surgery in this period, this technique could be employed in 160 cases (26.8%). Hospital mortality was 3.1% (5/160) and perioperative myocardial infarction as determined by daily EKGs and CKMB occurred in 4 patients (2.5%). Control hemodynamic studies were performed in 41 of the 160 patients (25.6%) with a patency rate of 83.9% in the 62 grafts restudied. We conclude that direct myocardial revascularization can be performed safely without major difficulties and with efficient anastomoses. The main advantages of the technique are that it does not require the use of extracorporeal circulation and, consequently, the use of any blood, as well as its low cost due to shorter hospitalization periods.

Adult↗
PubMed1985

Direct myocardial revascularization without extracorporeal circulation: technique and initial results.

In a 10-month period, 68 patients underwent saphenous vein bypass revascularization without extracorporeal circulation. Distal sutures were performed with interruption of coronary flow without any devices for perfusion of the coronary artery; the proximal sutures were completed with tangential clamping of the aorta. Most frequently, the anterior descending and the distal right coronary arteries were revascularized; of 225 patients who underwent bypass surgery, this technique was possible in 68 cases (30.2%). The 30-day hospital mortality was 1.5%, and perioperative myocardial infarction, as determined by daily electrocardiograms (ECGs) and creatine phosphokinase isoenzyme (CKMB), occurred in two patients. Control hemodynamic studies were performed in 22 of the 68 patients (32.4%) with a patency rate of 84.2% in the grafts restudied.

Journal Article↗
PubMed1985

Modified Blalock-Taussig shunt with an umbilical vein graft.

We describe a modification of the Blalock Taussig anastomosis, with the interposition of a glutaraldehyde-tanned umbilical vein graft between the subclavian and pulmonary arteries. This operation was performed in 64 children: 11 were less than 1 month of age (17.2%), and 23 were between 1 and 6 months of age (34.9%). Hospital deaths occurred in six patients-all less than 6 months of age (9.4%). There was no instance of shunt occlusion noted. The clinical course was uneventful among survivors, except for one patient who died of endocarditis in the late postoperative follow-up. The shunt procedure may be performed very rapidly, with minimal dissection, allowing the use of a graft larger than the diameter of the subclavian artery. This modification of the Blalock Taussig operation compares favorably with our previous experience with other shunt procedures and may be considered a valuable alternative in the palliative surgical treatment of several malformations with severe pulmonary oligemia.

Journal Article↗