For the past 2\m=1/2\years, most of the patients with hydrocephalus at the University of Michigan Medical Center have been surgically treated by establishing a ventriculovenous shunt between a lateral ventricle of the brain and the right atrium of the heart. The Holter valve has been employed in the procedure, and is designed to prevent backflow of blood into the ventricular system. Carrington1 has reported the results of the first 50 of these procedures. The purpose of this report is to call attention to the possible risk of fatal thromboembolism, a rare pediatric problem, as a complication of the shunt procedure.
Material and MethodThe 4 patients in this series were hospitalized on the service of the Department of Pediatrics and Communicable Diseases, and were operated upon by members of the Department of Neurosurgery. Necropsies were performed in the Department of Pathology. The Holter valve was surgically utilized in each instance. This unit consists of a pair of "fish-mouth" type valves connected by a siliconized rubber catheter. The valves allow only unidirectional flow of fluid and are regulated to open at pressures greater than either 10 mm. or 50 mm. of water. The valve unit is placed between 2 catheters which are made of siliconized rubber and impregnated with S'% barium sulfate solution to make them radiopaque.
Report of CasesCase 1.-This patient was first seen at The University of Michigan Medical Center at the age of 3 months with a lumbar myelomeningocele. The latter was draining purulent fluid, but there was no evidence of hydrocephalus. After conserva¬ tive therapy, drainage subsided and the patient was discharged.Four months later, she was readmitted with hydrocephalus, and a Holter valve ventriculovenous shunt procedure was performed. Prior to the procedure, head circumference was 18}4 in. and after the procedure it was 17% in.She was next seen at University Hospital at the age of 1 year with a short history of fever, lethargy, and redness of the myelomeningocele. Aspiration of the myelomeningocele yielded puru¬ lent fluid from which Hemophilus influenzae was cultured. This infection responded to a program of chloramphenicol, streptomycin, and sulfisoxazole. During each of the above hospitalizations, re¬ peated physical examinations and roentgenograms of the heart and lungs revealed normal findings.She was readmitted for the last time at the age of 17 months with rapid respirations and gen¬ eralized edema. Physical examination revealed a moderately cyanotic, edematous, and dyspneic in¬ fant. There was evidence of cardiomegaly, but no murmurs were heard, and the pulmonar)· com-