A 27-year-old Laotian woman with a St Jude mechanical mitral valve became pregnant, requiring a change in her anticoagulant after the first trimester when her warfarin sodium (coumadin) was replaced with enoxaparin sodium (lovenox). Her prosthetic valve clotted and became dysfunctional. She was 16 weeks pregnant and was taken to the operating room for emergency surgery for replacement of the valve. The fetus had not been viable for 1-2 weeks, but still remained in utero. The clotted valve was replaced with another St Jude valve of a slightly smaller diameter (27 mm). The patient could not be weaned from bypass so a right ventricular assist device (RVAD) was inserted. The patient was weaned from the RVAD after 2 days of support. Two days following removal of the RVAD the fetus spontaneously aborted. The patient had a long, complicated hospital course and was discharged 3 months later. She subsequently died 4 months after discharge of a cerebral hemorrhage from excessive anticoagulation.

Vacuum-assisted venous return (VAVR) has been reported to offer benefits for adults undergoing cardiopulmonary bypass (CPB), such as improved venous return, lowering priming volume (by eliminating the need to prime the venous line), and the use of smaller venous cannulae. All these benefits would be of particular value in pediatric perfusion because of the unique challenges of these smaller patients and the relatively large components of the CPB circuit. We have been using VAVR in children since the early summer of 1998 after we became comfortable with the technique and convinced of its efficacy in adults. Ours is a medium-sized pediatric caseload of slightly more than 100 CPB cases per year. With that caseload, it is most effective for us to minimize the inventory of different sizes of disposables used. We have opted for an oxygenator/reservoir that has a maximum flow of 4 liters with a priming volume of about 1 liter. We have been unhappy with the large prime volume in infants and earlier, in 1997-1998, were using a smaller prime oxygenator/reservoir until it was recalled. Faced again with a larger priming volume in the infants, we decided to try vacuum to decrease hemodilution and to evaluate other possible benefits. Through the use of VAVR, we have been able to decrease our priming volume, use smaller venous cannulae, and have more consistent return while experiencing no adverse effects of VAVR in our pediatric cardiac surgery patients.

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