Z. Vajda et al., Transcranial Doppler-determined pulsatility index in the evaluation of endoscopic third ventriculostomy (preliminary data), ACT NEUROCH, 141(3), 1999, pp. 247-250
Objective. Endoscopic 3(rd) ventriculostomy has become the method of choice
in the management of occlusive hydrocephalus. The treatment is accompanied
by significantly less peri-operative complications than the cerebrospinal
fluid shunting procedures previously employed. Close surveillance of patien
ts, however, is necessary to avoid the consequences of raised intracranial
pressure that may develop in case of obstruction of the artificial outlet o
f the 3(rd) ventricle.
The aim of this study was to confirm the value of transcranial Doppler-dete
rmined pulsatility index (PI) in the assessment of the patency of endoscopi
c 3(rd) ventriculostomy and to elucidate its usefulness in early postoperat
ive recognition of increased intracranial pressure.
Methods. In twenty-two patients suffering from occlusive hydro-cephalus, tr
anscranial Doppler sonography (TCD) was performed before, immediately after
, and five days after endoscopic fenestration of the floor of the 3(rd) ven
tricle. PI was defined with fast Fourier transformation. Mean PI values wer
e determined in both middle cerebral arteries (MCA), over five cardiac cycl
es.
Results. In nineteen cases, PI values showed a significant decrease immedia
tely as well as five days after the intervention as compared to the pre-ope
rative values, and flow-sensitive MRI confirmed the patency of the fenestra
tion in all cases. In one patient the operation failed to produce an effect
ive diversion of cerebrospinal fluid as shown by Bow-sensitive MRI, and the
pulsatility index was unchanged. In two patients, a significant immediate
postfenestration drop in PI was followed by a recurrence of PI to pre-opera
tive levels without any clinical deterioration.
Conclusions. Preliminary results suggest that the transcranial Doppler-dete
rmined pulsatility index is a useful non-invasive tool for the evaluation o
f the patency of the fenestration in the early follow-up of patients who un
derwent endoscopic third ventriculostomy.