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A C De Souza

Publications and source records attributed to A C De Souza.

9 recordsLinked to original sources
PubMed2003

Toward totally endoscopic coronary artery surgery.

BACKGROUND: Here we explore a method of using robotics to reduce morbidity and mortality in conventional coronary surgery. METHODS: Using a robotic surgical system two surgeons completed five steps: (1) 80 synthetic suture exercises; (2) 76 left internal thoracic artery to left anterior descending (LIMA-to-LAD) on porcine hearts; (3) cadaveric port placement for assessing optimal access; (4) endoscopic stabilization in the live porcine model; and, finally (5) eight clinical LIMA-to-LADs performed robotically. RESULTS: After 70 hours training, mean dry lab times fell from 7.0 and 5.8 min to 5.7 and 5.1 min in the two surgeonstab series. Wet lab times fell from 40.1 and 28.5 min to 28.8 and 19.2 min. In the clinical series of eight patients there were no mortalities; all had uncomplicated postoperative recovery and all were angina free at 6-week follow-up. CONCLUSION: The learning curve for robotic training is short, and reproducible results can be achieved clinically, after appropriate training, resulting in real patient benefit.

Animals↗
PubMed2001

Underlying and proximate determinants of diarrhoea-specific infant mortality rates among municipalities in the state of Céara, north-east Brazil: an ecological study.

This ecological study examines the variations in diarrhoea-specific infant mortality rates among municipalities in the State of Ceará, north-east Brazil, using data from a community health workers' programme. Diarrhoea is the main cause of postneonatal deaths in Ceará, and diarrhoea mortality rates vary substantially among municipalities, from 7 to 50 per thousand live births. To determine the inter-relationships between potential predictors of diarrhoea-specific infant mortality, eleven variables were classified into proximate determinants (i.e. adequate weight gain and exclusive breast-feeding in first 4 months) and underlying determinants (i.e. health services and socioeconomic variables). The health services variables included percentage with prenatal care up-to-date, participation in growth monitoring and immunization up-to-date, while the socioeconomic factors included female illiteracy rate, per capita gross municipality product and percentage of households with low income, percentage of households with inadequate water supply and inadequate sanitation, and urbanization. Using linear regression analysis variables were included from each group to build regression models. The significant determinants of variability in diarrhoea-specific infant mortality between municipalities were prevalence of infants exclusively breast-feeding, percentage of infants with adequate weight gain, percentage of pregnant women with prenatal care up-to-date, female illiteracy rate and inadequate water supply. These findings suggest that community-based promotion of exclusive breast-feeding in the first 4 months and care-giving behaviours that prevent weight faltering, including weaning practices and feeding during and following diarrhoea episodes, may further reduce municipality-level diarrhoea-specific mortality. Primary heath care strategies addressing these two proximate determinants provide only a partial solution to reducing diarrhoeal disease mortality. Improvements in municipal health services (prenatal care) and socioeconomic status variables, including water supply and maternal education, can also contribute to reduction of infant mortality due to diarrhoea. These results may be used by government health officials to set priorities by considering not only the strength of the association between selected risk factors and diarrhoea mortality rates, but also the prevalence of the risk factors being considered at the municipality level. Finally, the methods used are applicable to other settings with community-based primary health care decentralized to the state or municipal level.

Brazil↗
PubMed1999

Right ventricular function after pulmonary autograft replacement of the aortic valve.

BACKGROUND: The pulmonary autograft operation (the Ross procedure) involves excision of a portion of the right ventricular (RV) outflow tract, prolonged cross-clamp times, and insertion of a pulmonary homograft. There is concern about the effect of such operations on right ventricular function. METHODS AND RESULTS: Twenty-five patients undergoing either pulmonary autograft or homograft replacement of the aortic valve as part of a prospective randomized trial had echocardiographic RV long-axis measurements performed before surgery and 6 months (range 3 to 12 months) after surgery. In all patients, systolic excursion (SE) and both shortening and lengthening rates (SR and LR, respectively) were reduced postoperatively (P<0.05) (homografts: SE 1.5+/-0.4 versus 2.3+/-0.6 cm, SR 6.8+/-2.1 versus 9. 6+/-3.1 cm/s, LR 6.0+/-1.8 versus 8.9+/-3.0 cm/s; autografts: SE 1. 4+/-0.4 versus 2.2+/-0.4 cm, SR 5.8+/-3.0 versus 8.2+/-3.0 cm/s, LR 5.7+/-1.9 versus 8.5+/-3.7 cm/s). There were no differences between the 2 groups. Eighteen patients who had undergone either aortic homograft or pulmonary autograft surgery were studied between 6 and 35 months after surgery. RV volumes were assessed with the use of MRI in addition to echocardiographic RV long-axis measurements. Global volumes were increased to a similar amount in both groups (homografts: end-diastolic volume 145+/-34 mL, end-systolic volume 78+/-23 mL; autografts: end-diastolic volume 157+/-33 mL, end-systolic volume 89+/-25 mL; P=NS), whereas stroke volumes were maintained in both groups (homografts 67+/-15 mL, autografts 67+/-16 mL; P=NS). RV SE was depressed in both groups to a similar degree to that seen with the previous group (homografts 1.5+/-0.3 cm, autografts 1.4+/-0.2 cm). CONCLUSIONS: Aortic valve replacement with either a pulmonary autograft or an aortic homograft leads to a degree of persistent RV longitudinal dysfunction that is not more pronounced in those undergoing the Ross procedure. The mechanisms and long-term effects of these changes must be further studied.

Adolescent↗
PubMed1997

Re-do cardiac surgery in patients over 70 years old.

OBJECTIVE: This study was conducted in order to determine the outcome of cardiac re-operations in patients over the age of 70. METHODS: All patients who underwent 're-do' cardiac surgery at our institution, between January 1987 and October 1995 were identified. The case notes of patients over the age of 70 were reviewed retrospectively and follow-up was by telephone. RESULTS: A total of 687 re-do operations were performed during this 8 years and 9 months period. Operations, 110 (16%) were on patients aged 70 years and over (CABG 54, MVR 32, AVR 9, AVR + MVR 5, MVR + CABG 4, AVR + CABG 3, repair of paraprosthetic leak 2 and closure of VSD 1). Operations, 63 (57%) were elective and 42 (38%) were urgent. The median age was 73 years (range 70-82) and 64 patients (58%) were male. Pre-operatively, 78 patients (72%) were NYHA functional class III/IV and 55 (50%) had angiographically impaired left ventricular function (ejection fraction < 50%). The overall operative mortality was 7% (8/110). Median ITU stay was one night (range 1-21) and hospital stay was 7 days (range 5-35). Major in-hospital complications included resternotomy in five patients (5%), permanent stroke in three (3%), renal failure requiring haemodialysis in two (2%) and heart block requiring permanent pacing in two (2%). At a median follow-up of 34 months (range 2-101), 69 of the 77 patients alive at follow-up (90%) were NYHA functional class I/II. CONCLUSIONS: 'Re-do' cardiac surgery in patients over the age of 70 carries an acceptable operative morbidity and mortality with a good functional improvement at medium term follow-up.

Aged↗
PubMed1996

Randomized comparison of ultrasonic aspiration versus conventional electrocautery for dissection of the human internal thoracic artery.

The most common technique currently employed to harvest the internal thoracic artery for coronary artery bypass grafting is conventional electrocautery. This study compared an alternative method, electrocautery with an ultrasonic aspirator, for harvesting the internal thoracic artery. Patients were randomly assigned to one of six experimental groups (conventional electrocautery, ultrasonic aspirator at settings of 60%, 80%, and 100% power output, and ultrasonic aspirator in 100% CAVI-Pulse modes 1 and 3). Ring segments of internal thoracic artery were studied in an organ bath. Contraction responses were elicited with 123 mmol/L potassium physiologic salt solution, KPSS, KPSS solution containing noradrenaline, and a cumulative noradrenaline dose-contraction curve. Relaxation studies were performed with the vasodilators acetylcholine, bradykinin, and sodium nitroprusside. Forty percent of the electrocauterized vessels were traumatized or damaged and failed to respond to contractile stimuli, whereas only 10% of the vessels in ultrasonic aspirator groups 60%, 80%, and 100% failed to respond. All vessels in the group harvested by ultrasonic aspirator in 100% CAVI-Pulse mode 1 responded, whereas 20% of the vessels in the group harvested by ultrasonic aspirator in 100% CAVI-Pulse mode 3 failed to respond. All settings of electrocautery with an ultrasonic aspirator produced a greater contractile response to KPSS and noradrenaline. Acetylcholine and sodium nitroprusside produced similar relaxations in all groups, but the bradykinin responses were significantly improved in all groups undergoing 100% electrocautery with an ultrasonic aspirator. These results suggest that 100% electrocautery with an ultrasonic aspirator, particularly in 100% CAVI-Pulse mode 1, resulted in less damage and trauma than conventional electrocautery during harvesting of the internal thoracic artery.

Adult↗