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Biomedical subjects

A A Sader

Publications and source records attributed to A A Sader.

At least 19 recordsLinked to original sources
PubMed1999

Massive tracheal necrosis due to compression by an innominate artery aneurysm associated with a grade IV Chagasic megaesophagus and chronic duodenal ulcer.

A 49-year-old man suffered necrosis of the cephalad tracheal segment due to compression by an innominate artery aneurysm. A peritracheal abscess, a grade IV chagasic megaesophagus, and a duodenal ulcer were also present. The patient underwent a three-stage surgical treatment, and 7 years later he is doing well, and breathing and eating normally.

Abscess↗
PubMed1999

Intermittent anterograde normothermic blood cardioplegia: experimental study in rabbits.

BACKGROUND: We investigated the degree of myocardial protection provided by intermittent anterograde normothermic blood cardioplegia infusion for 60 minutes at 37 degrees C in normal rabbit hearts. METHODS: Thirty-two New Zealand rabbits were studied and divided into two groups: experimental group and control group. In the experimental group, normothermic blood cardioplegia was infused into the aortic root every 20 minutes over a one-hour period using a two-minute infusion dose. This amounted to an ischemic (unperfused) time of 52 minutes (or 86.6% of the total time). The biochemical investigation was carried out in two phases; Phase I: metabolic study after ischemia with no reperfusion and Phase II: metabolic and functional study after reperfusion. Reperfusion was carried out using a parabiotic perfusion system. Myocardial glycogen and mitochondrial respiration in the ventricular myocardium were established immediately after the end of intermittent cardioplegic solution infusion (Phase I) and after blood reperfusion (Phase II), when left ventricular function (dP/dt max) was also evaluated. RESULTS: At the end of Phase I, there was a significant decrease in myocardial glycogen levels to 58% compared with the control group. In Phase II, the differences in myocardial glycogen between the experimental and the control group were not significant. Mitochondrial respiration analysis did not show significant differences between the experimental and control groups, either in Phase I or II. In Phase I, dP/dtmax values were 903.39 +/- 113.46 mmHg/sec and 1,043 +/- 256.94 mmHg/sec for the experimental and control group, respectively. These differences were not statistically significant. CONCLUSIONS: Intermittent anterograde blood cardioplegia infusion every 20 minutes for 60 minutes at 37 degrees C was an effective myocardial protection method in normal rabbit hearts.

Animals↗
PubMed1993

Use of the platysma myocutaneous flap for cervical trachea reconstruction: an experimental study in dogs.

Cervical trachea reconstruction with a non-stented platysma myocutaneous door flap (NPMCF) was studied in 23 dogs. Window defects involving 5, 10, or 15 rings and the whole anterior tracheal wall were produced in 3 different groups of animals. A segmentary defect involving the resection of 3 tracheal rings but preserving the posterior membranous wall was created in another group. The results were evaluated by clinical follow-up of up to 100 days, by tracheoscopy 1 week after surgery, and by macroscopic and microscopic examination after the animals' natural death or sacrifice. The NPMCF proved to be adequate for the reconstruction of window defects limited to 5 and 10 rings, with success rates of 100% and 75%, respectively. The use of the NPMCF for tracheal reconstruction had the following main advantages: 1. relatively simple, easy, and expeditious surgery; 2. use of a single operative field; 3. availability of large amounts of donor tissue; 4. adequate thickness; 5. reliable irrigation; 6. resistance to environmental exposure as evidenced by absence of infection; and 7. 100% take rate with no granulomas or scar stenosis at the suture lines. However, luminal occlusion due to flap collapse was a 100% fatal complication when the NPMCP was used either for reconstruction of larger window tracheal defects (15 rings-group 3) or segmentary defects (group 4); this was the main limitation of the method, followed by hair growth with accumulation of secretions, which can be easily dealt with. It can be anticipated that this method has a potential for application in well-selected patients.

Animals↗
PubMed1991

Viability of single-pedicled tracheal flaps: an experimental study.

1. The objective of the present study was to test the viability of tracheal flaps of different widths and lengths for tracheal reconstruction in dogs, as well as the location of their pedicles. 2. Six types of single-pedicled tracheal flaps were prepared in 30 dogs as follows: narrow flaps with upper pedicles, wide flaps with upper pedicles, narrow flaps with lower pedicles, wide flaps with lower pedicles, narrow flaps with side pedicles, and wide flaps with side pedicles. 3. Flap condition was determined on the basis of clinical signs and by tracheoscopic, macroscopic and microscopic examination. 4. No statistically significant difference in viability was observed between narrow and wide flaps or between flaps with upper and lower pedicles, but all were less viable than side-pedicled flaps. 5. Poor coaptation of the flap borders produced deformities of tracheal architecture, with a significant incidence of necrosis occurring in poorly positioned flaps. The presence of poor coaptation was statistically significant in narrow flaps. Focal infection appears to influence the development of necrosis. We did not observe fibrosis or granulation tissue in sufficient amounts to cause significant stenosis of the tracheal lumen. 6. We conclude that single-pedicled tracheal flaps are viable and can be used for tracheal reconstruction when they are prepared with a length-width ratio of 5 to 10.

Animals↗
PubMed1991

[Surgical treatment of dysphagia lusória].

Two cases of this anomaly, in women (26 and 49 years old), with symptoms of short duration (4 and 3 months) of dysphagia, regurgitation and esophagitis, without loss of weight, are presented. In both, the final diagnosis was made by mean of thoracic aortogram. Esophagoscopy realized only in the first patient, demonstrated the pulsatile esophageal compression. The first patient was operated on through a right cervical incision, made in the anterior border of the sternomastoid muscle. In the second, a partial sternotomy, combined with a right supraclavicular prolongation, was used. In both, the anomalous artery was taken from the aorta and behind the esophagus, and anastomosed to the right common carotid artery. The dysphagia disappeared in the second case, but persisted attenuated, in the first one. Manometric studies realized in the 3rd and 18th months postoperatively demonstrated an aperistaltic segment of the esophagus (between 4 and 7 cm from the superior sphincter).

Adult↗
PubMed1983

Intraoperative measurement of the orifice area in patients with mitral valve stenosis.

This study was carried out in ten patients in order to compare results of mitral valve area evaluated by a new intraoperative technique and those provided by conventional hemodynamic methods. The results obtained correlated very well (r = 0.95) with values calculated by the Gorlin formula. Paired data checking were closer than 0.3 cm2 in all but one of patients with moderately severe mitral stenosis. It is concluded that the method for intraoperative measurement of the mitral valve area is simple, safe and reliable.

Adolescent↗
PubMed1983

Impairment of baroreflex control of the sinoatrial node after cardiac operations with extracorporeal circulation in man.

The sensitivity of the baroreceptor reflex to transient hypertension was determined in 13 patients before (control) and after (72 hours) open cardiac operations with extracorporeal circulation (ECC). In all patients early postoperative values were appreciably decreased (p less than 0.01) as compared to the preoperative values. This decrease suggested severe impairment of baroreflex control of the sinoatrial node. These changes were not correlated with concurrent alterations in heart rate or systemic arterial, left atrial, or right atrial pressures. In addition, respiratory sinus node arrhythmia was absent in all subjects. In four patients, subsequent studies 4, 8, 10, and 12 months, respectively, after the operation revealed good recovery of baroreflex sensitivity and respiratory influences on beat-to-beat variation. No similar effects were observed in two patients studied before and after cardiac operations without ECC. It is possible that direct trauma to the nervous supply of the sinoatrial node is a major factor in that reversible dysfunction; in fact, in three patients evidence was obtained that while sinoatrial node responses were impaired, the reflex control of the atrioventricular region remained unaltered. These findings point to further impairment of the fine control of heart rate imposed by the conditions of cardiac operations with ECC in patients with previously curtailed cardiac reserve.

Adolescent↗