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OBJECTIVE: It is our hypothesis that off-pump mitral valve
repair (MVR) is possible. As a preliminary step, we evaluated
methods of suturing the anterior and posterior mitral leaflets
under echocardiographic guidance in the beating heart.
METHODS: In 6 pigs, the left atrium was cannulated with
a customized 15mm port via a left thoracotomy. Arterial blood
was shunted into the atrium via the port to maintain a positive
pressure at all times to minimize air induction. Blood pressure
and cardiac rhythm were monitored. A multiplane transesophageal
echo (TEE) probe was tested in intraesophageal, epicardial and
intracardiac positions. Utilizing a commercial suturing device,
sutures were placed through the anterior and posterior mitral
leaflets under echo guidance.
RESULTS: There was no hemodynamic instability or significant
arrythmia. The most effective imaging plane was a short axis view
utilizing the TEE probe epicardially at the heart base. Air introduction
was minimal in 2 animals, mild in 3, and moderate in 1. Nine of
12 sutures were successfully placed, with a mean error of .8 ±
.5 cm. Technical difficulties included off -axis imaging, acoustic
shadowing from the device, large instrument size relative to valve
orifice, and snaring in chordae.
CONCLUSIONS: Basic surgical maneuvers were possible, and
this paradigm is promising as a method for off-pump MVR.
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