Comparison of Change in the Pulsatility Index before and after Ventriculoperitoneal Shunt Surgery in Adult Patients with Hydrocephalus

Background and aim: In hydrocephalus patients, after ventriculoperitoneal (VP) shunt, decrease in pulsatility index (PI) correlates with decrease in ventricle size. Also, increase in PI is noted in obstructed or malfunctioning VP shunts. However, previous studies were either done in infants and children or included patients of all age groups. Our aim was to compare PI before and after successful VP shunt surgery in adult patients and also the trend of transcranial Doppler (TCD) parameters for 3 days after surgery.

Materials and methods: A prospective, observational study was done in 20 adult patients undergoing VP shunt. Clinical features, vitals, Evans index, and TCD parameters were noted in the preoperative period. A computed tomography (CT) head was repeated 4-6 h after surgery, and the position of ventricular end of shunt was confirmed and Evans index was calculated. The vitals and TCD parameters were noted at same time and for the next 2 days. Repeated measures analysis of variance (ANOVA) and paired t-test were uses for statistical analysis.

Results: A total of 18 patients were included for statistical analysis. The mean preoperative PI was 1.19 ± 0.24 and the postoperative PI after surgery was 0.97 ± 0.17, 0.97 ± 0.23, and 0.94 ± 0.21 (P = 0.0039) on postoperative day (POD) 1 (POD1), POD2, and POD3, respectively. The mean preoperative value of Evans index was 0.37 ± 0.06 and there was statistically significant (P = < 0.001) reduction to 0.33 ± 0.07 after VP shunt surgery. The change in PI and change in Evans index were found to be positively correlated (r = 0.34 and P = 0.0013).

Conclusions: The decrease in PI after VP shunt surgery correlates with decrease in ventricular size. Any increase in PI in the postoperative period should raise the suspicion of malfunctioning of VP shunt.