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Biomedical subjects

A Padrón

Publications and source records attributed to A Padrón.

7 recordsLinked to original sources
PubMed2001

[The non Q wave myocardial infarction in conventional valvular surgery. Diagnosis with cardiac troponin I].

INTRODUCTION: Morbidity and mortality in elective valve surgery is still significant. The main cause of death in these patients is cardiogenic shock, of which the most frequent etiology is acute myocardial infarction (AMI) with Q wave in the ECG. However, there are patients with cardiogenic shock without Q wave in the ECG and with rises in CK-MB enzyme that makes us suspect non-Q wave AMI. OBJECTIVE: To analyze the use of the determination of cardiac troponin-I, a more specific marker of AMI than CK-MB after cardiac surgery, to detect perioperative non-Q wave AMI, and to establish its clinical significance. METHODS: A total of 147 patients without coronary artery disease scheduled for elective valve surgery were included. We used, based in anterior publications, ECG (presence or not of new Q wave) and cardiac troponin I to define perioperative AMI. Levels of cardiac troponin-I were analysed before surgery and 14 hours after. Non-Q wave AMI was diagnosed when troponin I was superior to 38.85 ng/ml and there was not a phatologic Q wave in ECG. RESULTS: One hundred twenty-three (83.67%) of patients did not have AMI, 9 (6.12%) suffered perioperative AMI with Q wave, and 15 (10.27%) carried out criteria of non-Q wave perioperative AMI. Morbidity and mortality in this last group was similar to that in the group with Q wave AMI. Morbidity and mortality were minimum in patients without AMI. CONCLUSIONS: This study suggest the possibility of in vivo identification of non-Q wave perioperative AMI, an entity with important morbidity and mortality in our series, with a simple determination of cardiac troponin I 14 hours after surgery.

Adult↗
PubMed2000

Distraction osteogenesis of the ascending ramus for mandibular hypoplasia using extraoral or intraoral devices: a report of 8 cases.

PURPOSE: This report presents the results of distraction osteogenesis using unidirectional extraoral and intraoral devices in 8 patients with different grades of vertical mandibular ramus hypoplasia. PATIENTS AND METHODS: Eight patients with hypoplastic mandibles underwent unilateral lengthening of the ascending ramus using unidirectional extraoral or intraoral devices. Intraoral mandibular distraction was performed on 5 patients with deficiencies of the vertical ramus up to 24 mm. External devices were used in 3 patients with more severe hypoplasias. An intraoral osteotomy was performed, and progressive distraction at rates of 0.5 mm/12 hours was initiated after 5 days. Once the desired length was reached, the device was maintained in place for 8 to 12 weeks. Three-dimensional computed tomography scans were taken in all the patients to plan the procedure and to compare the changes postoperatively. RESULTS: Successful distraction osteogenesis was achieved in all patients. The amount of mandibular lengthening ranged from 17 to 32 mm. Complications with the external devices such as rotation of the proximal bony fragment (2 cases) and loosening of the external screws at the end of the consolidation period (1 case) were observed. CONCLUSIONS: The results suggest that the intraoral device can be used as the method of choice for distraction osteogenesis of the ascending ramus of the mandible in patients with large deficiencies. Preoperative and postoperative 3-dimensional computed tomographic scans are essential in treatment planning.

Bone Screws↗
PubMed1999

A new transfacial approach for lesions of the clivus and parapharyngeal space: the partial segmented Le Fort I osteotomy.

Tumors of the clival and parapharyngeal areas are a challenge because of their location. They used to be considered inaccessible because the aggressive approaches employed caused elevated levels of morbidity. This fact led to more conservative approaches that attempted to preserve the exposure of the lesion. These approaches were a combination of cranial and facial procedures, thus utilizing a combined effort between neurosurgeons and maxillofacial surgeons. We described our experience with a partial segmented Le Fort I osteotomy added to a transmandibular approach to expose a chordoma of the clivus and left parapharyngeal space. A three-dimensional imaging was used as a diagnostic tool and to plan the optimal surgical approach. The operative technique was described in this case study. Some important technical details of the approach are described. The global outcome was favorable.

Adult↗
PubMed1997

A new experimental model of isolated myocardial ischemic injury: ECG findings of acute isolated right ventricular ischemic injury.

A new experimental porcine model for creating selective ischemia of a specific part of the myocardium while the rest of the myocardium remains free of ischemia has been used to study the electrocardiographic (ECG) changes deriving from selective ischemia of the right ventricular (RV) free wall. A patch was stitched to the ventricle to produce selective myocardial ischemic injury. In a preliminary study of nine pigs, selective ischemia of the left ventricular free wall in five and of the RV free wall in four animals was induced, and a postmortem dye injection was performed to evaluate blood flow in the area of ischemia. In an ECG study of 20 pigs, the baseline ECG was recorded with use of the standard leads I-III, aVR, aVL, and aVF, left precordial leads (V1-V6), and leads V4R, V3H, and V4H and 1 hour after inducing ischemia, the ECG study was repeated. Our experimental model produced ischemic injury in which the location and surface area were known antemortem. In the 20 pigs, ST-segment changes were recorded in leads V1-V3, V3H, and V4H. In only four pigs (20%) was ST-segment elevation recorded in lead V4R. The results show that the ECG signs of selective ischemia of the RV free wall may imitate the signs of anterior or anterolateral infarction of the left ventricle. In this study, elevation of the ST-segment in lead V4R was not pathognomonic of for RV ischemia. This model is a new tool for studying hemodynamic and ECG changes of selective univentricular or biventricular ischemic injury.

Animals↗
PubMedDate not supplied

[Stereotaxic biopsy and 192Ir implant in intracranial tumors. A review of 7 years of experience].

INTRODUCTION: The combination of stereotaxic techniques, advances in neuroimaging and the creation of continually improving software has permitted stereotaxic biopsy of cerebral lesions at the most varied sites. Improvement in the method of permanent interstitial radiation (brachytherapy) improves the precision with which the radioactive sources may be inserted, releasing a maximum dose of radiation to the tumour with minimum radiation to the surrounding tissue. PATIENTS AND METHODS: We treated 237 patients (aged 1 to 78 years) with intracranial lesions, all included in the protocol of our centre. Stereotaxic systems of Leksell, Riechert-Mundinger, Micromar and Estereoflex were used. The procedure was in three stages: acquisition of the image, surgical planning and surgical operation. The imaging guide was the computerized axial tomography (CAT). RESULTS: Stereotaxic biopsy guided by CAT images was done in 153 patients. These were divided into three groups, taking the biopsy findings as the reference: group A (primary tumors, 128), group B (metastatic tumors, 15) and group C (non-malignant lesions, 10). Ninety six permanent implants of 192Ir were inserted, with a low dose of 4-7 cGy/h and a total dose of 80-120 Gy. CONCLUSIONS: Stereotaxic biopsy is a very effective procedure with a significantly low range of complications. The permanent implant with a low dose rate, well situated and using a source of 192Ir is a safe, simple, effective method for the treatment of primary and recurrent glial tumours, and non-glial tumours which fulfil criteria for this type of brachytherapy.

Adolescent↗