Evaluation of the yield of post-clipping angiography and nationwide current practice

Abstract

Background: Surgical treatment of intracranial saccular aneurysms aims to prevent (re)hemorrhage by complete occlusion of the aneurysmal lumen. It is unclear whether routine postoperative imaging, to assess aneurysmal occlusion, is necessary since intraoperative assessment by the neurosurgeon may be sufficient. We assessed routine clinical protocols for post-clipping imaging in the Netherlands and determined whether intraoperative assessment of aneurysm clippings sufficiently predicts aneurysm residuals.

Methods: A survey was conducted to assess postoperative imaging protocols in centers performing clipping of intracranial aneurysms in the Netherlands (n = 9). Furthermore, a retrospective single-center cohort study was performed to determine the predictive value of intraoperative assessment of aneurysm occlusion in relation to postoperative digital subtraction angiography (DSA) findings, between 2009 and 2017.

Results: No center performed intraoperative DSA in a hybrid OR, routinely. Respectively, four (44.4%), seven (77.8%), and three (33.3%) centers did not routinely perform early postoperative imaging, late follow-up imaging, or any routine imaging at all. Regarding our retrospective study, 106 patients with 132 clipped aneurysms were included. There were 23 residuals ≥ 1 mm (17.4%), of which 10 (43.5%) were unexpected. For the presence of these residuals, intraoperative assessment showed a sensitivity of 56.5%, a specificity of 86.2%, a positive predictive value of 46.4%, and a negative predictive value of 90.4%.

Conclusions: There is lack of consensus regarding the post-clipping imaging strategy in the Netherlands. Since intraoperative assessment is shown to be insufficient to predict postoperative aneurysm residuals, we advocate routine postoperative imaging after aneurysm clipping unless this is not warranted on the basis of patient age, clinical condition, and/or comorbidity.

Keywords: Residual; Retreatment; Ruptured; Saccular aneurysm; Surgery; Unruptured.

Fig. 1

Pie charts of the responses on the national survey regarding postoperative imaging (n = 9). Left: early postoperative imaging (< 90 days post clipping). Right: late follow-up imaging (> 90 days post clipping). CTA computerized tomographic angiography; DSA (or 'angiography') digital subtraction angiography

Fig. 2

DSA images of a patient with a postoperative residual requiring coiling. a Preoperative 3D-reconstruction of the rotational angiogram demonstrating a ruptured, 3.7 mm, left PCoA aneurysm. b Postoperative 3D-reconstruction of the rotational angiogram showing residual filling. c DSA (lateral projection) showing the result of coiling. DSA digital subtraction angiography, PCoA posterior communicating artery

Fig. 3

DSA images of a patient with a postoperative residual requiring re-clipping. a DSA (lateral projection) demonstrating a ruptured, 14.0 mm, PCoA aneurysm. b Postoperative DSA (lateral projection) showing residual filling of the entire aneurysm. c DSA (lateral projection) showing successful re-clipping. DSA digital subtraction angiography, PCoA posterior communicating artery