Intraoperative Doppler and Duplex sonography in cerebral aneurysm surgery

The aim of open surgery of cerebral aneurysms is to minimise the risk of infarction due to poor position of a clip while still securing the aneurysm from rebleeding. Whilst digital subtraction angiography (DSA) remains the gold standard for precise evaluation of the result, its invasiveness, risk of thromboembolic infarction, availability and time-consumption pose a significant limitation, and overall it is rarely used. The goal of the present study was to analyse the feasibility of intraoperative B-mode Duplex ultrasound in combination with Doppler sonography (DDS) to evaluate this issue.

A total of 44 aneurysms in 40 patients were investigated intraoperatively via B-mode and power Duplex sonography after clip positioning in a prospective setting. Data were then compared to postoperative angiography.

In 38 cases DDS allowed for visualisation of aneurysm localisation, neck and diameter, as well as associated vessels, in accordance to preoperative DSA. This was confirmed by Duplex sonography in 94.7%. Further evaluation of each associated vessel after clip positioning was then enabled by Doppler sonography in 84.8%. Visualisation in terms of B-mode sonography was not successful in six cases due to multiple clips.

DDS is an additional tool for immediate evaluation of clipping performance intraoperatively and can be used in simple cases with reliable results. In six cases Doppler-/Duplex-sonography did not illustrate the clipping result sufficiently. It is not yet able to replace DSA in aneurysms with complex configuration.