Transcranial doppler ultrasonography for the evaluation of shunt malfunction in pediatric patients

Abstract

Previous studies have demonstrated a high correlation between hydrocephalus and the resistive index (RI), as determined by transcranial Doppler ultrasonography. Measurements of RI, calculated by dividing the difference between the peak systolic velocity and the end-diastolic velocity by the peak systolic velocity, were attempted in 55 pediatric patients during evaluations for ventriculoperitoneal shunt malfunctions; values were obtained in 52. Indications of shunt malfunction included both clinical and radiographic evidence of increased intracranial pressure. Eleven patients, determined to have functional shunts both by clinical criteria and subsequent outcome, had RIs of 47 +/- 5 (average +/- 1 standard deviation). Shunt malfunctions were confirmed in 41 patients. Prior to shunt revisions, these 41 patients had RIs of 71 +/- 10%; following revision, the RIs fell to 53 +/- 12%. Nine patients had had pre-malfunction RIs of 48 +/- 11% obtained during routine follow-ups; when they subsequently had shunt malfunctions, their RIs had significantly increased. Four of the 41 patients with shunt malfunctions had essentially normal RIs (52 +/- 7%), but had fluid tracking along the shunt; in these, RIs were essentially unaffected by shunt revision. For comparison, 119 pediatric patients with clinically functional ventriculoperitoneal shunts had RIs of 50 +/- 9%. The data, statistically significant with a P value of less than 0.001, showed a correlation between elevated RIs and shunt malfunction; thus, transcranial Doppler ultrasonography is a practical, non-invasive technique useful in the diagnosis of ventriculoperitoneal shunt malfunction.

Medida da velocidade de fluxo nas artérias cerebrais utilizando ultra-som Doppler transfontanela antes e após o tratamento cirúrgico da hidrocefalia

“…Ainda segundo os trabalhos de Hill e Volpe 14 , Alvisi e col. 19 Chadduck e col. 16 , Goh e col. 21 e Huang e Chio 22 , a utilização da técnica de US-Doppler com evolução sequencial do IR, usada em conjunto com as observações de caráter clínico é extremamente útil e pode predizer a necessidade de indicação de shunt de derivação liquórica.…”

“…A partir de 1982, com a publicação dos estudos de Hill e Volpe 14 , surgiram vários trabalhos procurando determinar as alterações do fluxo pulsátil nas artérias cerebrais utilizando a técnica de US-Doppler em crianças portadoras de hidrocefalia. As pesquisas instituídas objetivaram a determinação do "timing" para cirurgia 13 , observar o comportamento do índice de resistência (IR) em relação ao aumento da dilatação ventricular 15 , determinar a necessidade de shunt ventrículo-peritoneal através da evolução sequencial do IR 16 e diagnosticar o funcionamento inadequado dos sistemas de derivação liquórica 17 .…”

Cerebrospinal fluid shunt dynamics in patients with idiopathic adult hydrocephalus syndrome.

“…44 The rationale may be that the shunt dysfunction comes near to the CSF dynamic investigation. Gait and MMSE scores failed to improve in patients with functioning shunts (patients 10,16,17,29), probably because of irreversible brain damage.…”

The Retrograde Ventriculovenous Shunts: The El-Shafei Retrograde Ventriculojugular and Ventriculosinus Shunts

“…In patients with open craniums, Pourcelot’s transcranial Doppler resistive index1 (RI) [10] was recorded before and after surgery and in the follow-up studies. The RI was also recorded for 10 patients with closed craniums in the follow-up studies.…”