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Year : 2000  |  Volume : 48  |  Issue : 1  |  Page : 89--90

Shunt migration into a Dandy Walker cyst.

PK Gupta, KS Mann 

Correspondence Address:
P K Gupta

How to cite this article:
Gupta P K, Mann K S. Shunt migration into a Dandy Walker cyst. Neurol India 2000;48:89-90

How to cite this URL:
Gupta P K, Mann K S. Shunt migration into a Dandy Walker cyst. Neurol India [serial online] 2000 [cited 2021 Oct 24 ];48:89-90
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Full Text

Shunt migration is a less frequent complication of shunt surgery for hydrocephalus. It is known to migrate into all the possible sites in the body. Cranial migration is rare. Shunt migration into a Dandy Walker cyst has not been reported. Such a case is reported.

Two year old child was treated in 1993 for delayed motor milestones, inability to walk and bilateral hypotonia. Muscle power was normal. CT of the brain showed a large Dandy Walker cyst with minimal lateral and third ventricle dilatation. The child underwent cysto-peritoneal shunt (Codman medium pressure unishunt) and improved. He was doing well for three years and started walking. On a routine follow-up visit, the shunt tube was not palpable. There were no symptoms or signs of raised intracranial pressure. X-ray of the skull showed a curled-up shunt tube in the posterior part of the head [Figure 1]. Repeat CT of the brain showed Dandy Walker cyst with migrated shunt tube [Figure 2]. As the child was asymptomatic, the parents did not agree for any surgical intervention. The child remained symptom free till date.

Shunt migration is rare and constitutes 0.1% of all shunt procedures. Majority of patients, like the present one, had been infants and children. Shunt migration is more frequent with hard and spring loaded shunt tubes. This complication is infrequent with flexible shunt systems,[1] but they are more prone to obstruction due to bending and torsion. Migration may be in either direction. Distal migration of the shunt has often been reported. Cranial migration is rare and only few cases have been reported. Shunt migration into a Dandy Walker cyst has not been reported. The mechanism of shunt migration involves adhesion, necrosis, penetration, perforation, migration and extrusion.[2],[3] Pressure gradient between two cavities decide the direction of migration.[4] It can be early or late and is assisted by tortuous subcutaneous tract and neck movements. Shunt chamber prevents shunt migration. The shunt tube used in this child did not have a chamber. Migration of shunt is not prevented by locks and slip clips.[5] In this case, additional sutures were placed around the tube to secure the shunt in place.

Shunt migration usually presents as raised intracranial pressure. Absence of raised intracranial pressure in this case suggests equilibration of CSF pressure gradient. Diagnosis in such cases is incidental and the patient can be followed up expectantly. However presence of raised intracranial pressure would require removal of migrated shunt and implantation of a new shunt, preferably with a reservoir.


1Ho M, Sato 0, Tsugane R et al: Abdominal complications of ventriculo-peritoneal or lumbo-peritoneal shunt operation -a bowel perforation and historical review. No Shinkei Geka 1981; 9:81-88.
2Rabin RC, Ghatak NR, Visudhipan P: Asymptomatic perforated viscus and gram negative ventriculitis as a complication of valve regulated ventriculoperitoneal shunts. J Neurosurg 1972; 37: 616-618.
3Rao CC, Krishna G, Haselby K et al: Ventriculobronchial fistula complicating ventriculo-peritoneal shunt. Anaesthesiology 1977; 47: 388-390.
4Thauvoy C, Kallel S, Marion B et al: Unusual complication of peritoneal drainage: migration of shunt in the subdural space. Child Nerv Syst 1989; 5(l): 47-49.
5Eljamel MS, Sharif S, Pidgeon CN: Total intraventricular migration of unisystem ventriculoperitonral shunt. Acta Neurochir Wien 1995; 136(3-4): 217-218.