When the infants were wrapped in cotton wool (Gough, 1960) the average drop in temperature was only 1 * 56°C and only 0 3°C if they were put on a warm water mattress (Calvert, 1962). The small baby is also at some risk of abnormal loss of heat on the journey to and from the operating theatre and especially during the induction of anaesthesia and the process of being put in a suitable position on the operation table. It has been recommended that the temperature and humidity of the operating theatre should be raised enough to prevent undue heat loss by the baby, but this causes so much discomfort and loss of efficiency in those working in the theatre that it is seldom used. After earlier observations in this department (Gough, 1960)

✓ Ten cases of cardiac tamponade caused by pericardial perforation by a Holter catheter in the treatment of hydrocephalus by ventriculoatrial drainage are reported. These 10 cases occurred in an 8-year practice of two surgeons in a period during which approximately 1800 Holter shunts were inserted and an approximately equal number of operations for lengthening of the distal catheter were performed. The etiological factors, the clinical picture, and the diagnosis are discussed. Cardiac perforation is caused either by forceful introduction of the distal catheter during a shunt revision procedure or by too long a distal catheter that ulcerates through the cardiac wall. Enlargement of cardiac silhouette after shunt insertion is virtually diagnostic of a pericardial effusion. If undiagnosed, this condition was invariably fatal, but if diagnosed in time, immediate treatment was always curative. The distal catheter should be shortened, but suture of the cardiac perforation itself is not necessary.

(87) were most frequent. The commonest urinary signs and symptoms were palpable bladder (93) and urinary infection (90).An accurate diagnosis was obtained by intravenous pyelography or cystourethrography.Treatment was directed to correction of electrolyte and water disturbances, followed by early relief of the obstruction.The mortality rate was 32 * 5% for children admitted in the first month of life, and only 8% thereafter, with an overall rate of 18%.The commonest cause of renal failure in the first year of life in Britain is a congenital abnormality of the urinary tract (Lloyd-Still and Atwell, 1966). Among these, lower urinary obstructions form a large group of potentially curable lesions with similar presenting features.The term lower urinary obstruction is used to include all lesions at or below the bladder neck which interfere with normal urine flow.165 patients with a lower urinary obstruction were admitted to The Hospital for Sick Children, under the care of Mr. Innes Williams, from 1959-1970. There were 130 boys and 35 girls. The ages at presentation are shown in Fig. 1 figure.

similar simple technique to our own had no deaths in 240 insertions. Two of our children died following insertions. In the first, a subdural haematoma was found on the side of the operation, and in the second, there was intraventricular and subarachnoid haemorrhage. A third child had a cardiac arrest on the operating table during skin closure after the insertion of his third shunt. Autopsy revealed no cause for his death.

SUMMARY 159 therapeutic operations for obstruction of the distal catheter in the Holter ventriculoatrial shunt are reviewed. Prophylactic, as opposed to therapeutic, lengthening of the distal catheter has been established at our hospital and the results of 163 prophylactic operations are reviewed. The technique of the operation is described. Prophylactic lengthening of the distal catheter is recommended in order to keep the shunts patent and functioning in shunt‐dependent hydrocephalic children and to avoid the difficulties and risks of therapeutic revisions. RÉSUMÉ Les auteurs examinent 159 opérations thérapeutiques pour obstruction du cathéter distal dans le shunt ventriculo‐atrial de Holter. Dans notre hospital on pratique l'allongement prophylactique du cathéter distal, au lieu de l'allongement thérapeutique; les résultats de 163 opérations prophylactiques sont examinés. On décrit la opératoire. L'allongement prophylactique du cathéter distal est recommandé dans le but de garder les shunts ouverts et en bon fonctionnement chez les enfants hydrocéphaliques dépendant de shunt, et pour éviter les difficultés et les risques des révisions thérapeutiques. ZUSAMMENFASSUNG Es werden 159 therapeutische Operationen infolge Obstruktion des distalen Katheters im Holter‐Ventrikulo‐Atrial‐Shunt besprochen. Prophylaktische, im Gegensatz zu therapeutischer Verlängerung des distalen Katheters, hat sich in unserem Krankenhaus eingebürgert und die Resultate von 163 prophylaktischen Operationen werden besprochen. Die Operationstechnik wird beschrieben. Prophylaktische Verlängerung des distalen Katheters wird empfolhen, um die Shunts von hydrocephalischen Kindern, welche davon abhängig sind, offen und funktionsmässig zu halten und die Schwierigkeiten und Risiken therapeutischer Revisionen zu vermeiden.