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Isaac Kadir

Publications and source records attributed to Isaac Kadir.

2 recordsLinked to original sources

Aortic arch replacement using a trifurcated graft: simple, versatile, and safe.

BACKGROUND: Hypothermic selective antegrade cerebral perfusion during aortic arch replacement may prevent adverse neurologic sequelae. It can be provided via balloon-tipped catheters or a branched graft sewn to the brachiocephalic vessels. We report a consecutive series of total arch replacement using a trifurcated graft. METHODS: From September 1999 through October 2004, 109 patients underwent nonemergent total arch replacement using this technique. The graft, placed during a period of hypothermic circulatory arrest, was used for selective cerebral perfusion during the arch reconstruction. RESULTS: Adverse outcomes were seen in 9 (8.3%) patients: hospital death in 5 (4.6%), and stroke in 5 (4.6%). Transient neurologic dysfunction was noted in 6 (5.5%) patients. Mean duration of hypothermic circulatory arrest was 31.2 +/- 6.6 minutes and selective cerebral perfusion was 65.3 +/- 20.9 minutes. Reoperation for bleeding was required in 3 (2.8%) patients and prolonged intubation in 15 (13.8%). Median intensive care unit stay was 3 days (interquartile range 2-4; range, 1 to 108) and hospital stay was 9 (interquartile range 8-15; range, 5 to 108). CONCLUSIONS: The trifurcated graft technique results in low rates of perioperative mortality, temporary neurologic dysfunction, and stroke. It may reduce cerebral embolization as it requires no instrumentation of the aortic arch to establish selective cerebral perfusion and, although it mandates hypothermic circulatory arrest to place the graft, this interval is reliably brief enough to fall within accepted safe limits. This strategy leaves no residual arch tissue behind, and allows placement of an elephant trunk proximal to one or more arch vessels if anatomically indicated.

Adult↗

Comparison of exercise and dobutamine echocardiography in the haemodynamic assessment of small size mechanical aortic valve prostheses.

OBJECTIVE: Doppler echocardiographic evaluation of prosthetic heart valve function is usually performed at rest although this situation is not representative of patients' daily activities. Following aortic valve replacement, patients most likely to remain symptomatic are those with a small aortic root and dobutamine or exercise echocardiography has been proposed to elicit the presence of abnormal haemodynamics or persistently elevated transvalvular gradients in these patients. This study was carried out to compare dobutamine echocardiography with a symptom limited treadmill exercise echocardiography in patients following aortic valve replacement with a small size (19 mm) St. Jude Mechanical valve prosthesis. METHODS: The study population consisted of ten unselected patients following aortic valve replacement. Dobutamine was infused intravenously starting at 5 microg/kg/min and increasing by 5 microg/kg/min at 15 min interval up to 20 microg/kg/min. Heart rate, blood pressure, cardiac output (CO), peak and mean gradients as well as effective orifice area (EOA) were measured. These parameters were also measured following a symptom limited treadmill exercise. RESULTS: Dobutamine stress increased heart rate (HR) and CO by 50 and 74%, respectively (both P<0.0002), and mean transvalvular gradient from 22+/-4.1 mmHg at rest to 40.0+/-10 mmHg at maximum stress (P<0.001). With exercise, HR and CO increased by 48 and 70%, respectively while mean transvalvular gradient increased from 22+/-3.1 mmHg at rest to 38.0+/-6.4 mmHg (P<0.0001). The maximum increase in HR, CO and mean transvalvular gradient with dobutamine and exercise were similar however. There was no significant change in the EOA with either dobutamine or exercise. CONCLUSION: The result suggests that both treadmill exercise and dobutamine stress echocardiography are equally effective for the hemodynamic evaluation of small aortic valve prosthesis.

Adrenergic beta-Agonists↗