32-year-old female suffered from intermittent partial seizures with secondary tonic and clonic generalization for 5 years under regular medical treatment. The seizure frequency increased recently. The deteriorated seizure control brought the patient back to hospital to seek further treatment.
Left cuneus region S-M grade II arteriovenous malformation (AVM).
Craniotomy with surgical removal of the AVM was undertaken. The surgical course was uneventful. After surgery, no more seizures were noted during medical treatment.
DSA with syngo iFlow post-processing quantitatively illustrates the peri-surgical hemodynamic changes that related to the AVM. Before surgery (Fig. 1), TTP (time to peak opacification on DSA) of left PCA, the main feeding artery of AVM, is 2.83 seconds, which is shorter than the right PCA (3.83 seconds). The difference mainly results from the AV shunts that occur in the AVM, where a pressure gradient of blood flow is present. The gradient decreases the resistance in the artery and “steals” blood flow from the right side to the left PCA and makes the TTP of left PCA shorter. After surgical removal of the AVM (Fig. 2), the AV shunts are deleted and the pressure gradient is no longer present. No more blood flow is needed to compensate the pressure gradient. Equalization of TTP (3.13 seconds) is illustrated on left PCA and right PCA.
Before surgery, the TTP of the left PCA (the main feeding artery of AVM) is 2.83 seconds, which is shorter than the right PCA (3.83 seconds).
After surgical removal of the AVM, the AV shunt is deleted and the pressure gradient is no longer present. No more blood flow is needed to compensate the pressure gradient. The TTP of the left PCA and right PCA are equalized (3.13 seconds).