SHUNT COMPLICATIONS IN THE FIRST POSTOPERATIVE YEAR IN CHILDREN WITH MENINGOMYELOCELE

The authors analyze the incidence of early mechanical and infective CS F shunt complications and various factors that might be correlated wit h the incidence in a series of 170 children affected by hydrocephalus and meningomyelocele (MM), with the aim of finding specific risk facto rs related to this particular type of hydrocephalus. Factors investiga ted for correlation with CSF shunt malfunction are the following: leve l of the spinal malformation, age of the patient at MM repair, age at diagnosis of hydrocephalus, degree of the ventricular dilatation: age at CSF shunt implantation. modality of the surgical procedure, charact eristics of CSF at operation. Tn the first postoperative year followin g CSF shunting. 45.9% of the patients presented one shunt malfunction, three-quarters of which were due to mechanical causes, and one quarte r to infection. Age of the patient at diagnosis of hydrocephalus and a t CSF shunt operation did not significantly influence shunt patency no r did the surgical modality (programmed vs emergency procedure). On th e other hand, MM level did influence the outcome of CSF shunting: a hi gher percentage of malfunctions (and in particular of infective compli cations) was observed among the patients with ''high level'' MMs than in the group with more caudal location of the spinal defect. Similarly , the degree of ventricular dilatation correlated with the incidence o f complications (more severe ventricular dilatation was associated wit h the highest incidence of complications). The order in which MM repai r and CSF shunting were carried out and the age of the patients at MM repair did not affect the occurrence of mechanical complications, wher eas they had a significant effect on the incidence of infective compli cations. In fact, the rate of overall complications. and of infective complications in particular, was proportional the age at MM repair. Fu rthermore, the group of children who underwent to MM repair and CSF sh unting simultaneously scored the lowest percentage of complications, a lthough these were mainly infections: the highest incidence of complic ations (and in particular of infective ones) was observed in the child ren who underwent CSF shunting first. The most striking correlation, h owever. was found with the characteristics of CSF While normal CSF val ues correlated with an overall incidence of complications of 39.2%, ab normal CSF values were correlated with a rate of complications of 90.9 %; in particular, the rates of infective complications were 2.7% and 7 7.3%, respectively. On the grounds of these observations a protocol is proposed of temporary CSF external drainage in children requiring pro mpt relief of increased intracranial pressure but at risk for the pres ence of a leaking spinal defect or of a MM left unrepaired for more th an 48 h.