Assessment of the clipping efficacy of intracranial aneurysms: analysis of the employed methodology in relation to case difficulty

Progressive postoperative slippage of titanium aneurysm clip confirmed by follow-up radiographic imaging studies and by reoperation: a case report

We report a case of postoperative slippage of a titanium clip that was used for a small ruptured anterior communicating artery aneurysm. Clipping was successful with no remnant in the initial operation. Progressive slippage of the clip was observed in follow-up brain computed tomography angiography studies. Digital subtraction angiography confirmed this finding. Reoperation was performed 19 days after the initial craniotomy. The clinical course after reoperation was uneventful.

Incidence of Postoperative Cerebral Aneurysm Clip Slippage: Review of a Consecutive Case Series of 115 Clipped Aneurysms

OBJECTIVE

Although delayed postoperative clip slippage has been reported in previous case reports and case series, its true incidence with high rate of follow-up imaging has not been reported. We attempted to determine the incidence of clip slippage in a cohort of consecutive aneurysm clippings.

METHODS

We performed a retrospective review of a prospectively maintained database of 115 consecutive saccular aneurysm clippings at a single institution. Postoperative imaging was reviewed for clip slippage within 24 hours and at 3-12 months. Eighty-six aneurysms (75.8%) were exclusively clipped with Sugitaclip (Mizuho Medical, Tokyo, Japan) Titanium II clips, 16 aneurysms were exclusively clipped with Yaşargil (Aesculap, Center Valley, PA) titanium clips (13.9%), 5 aneurysms were only clipped with Sugita aneurysm clips (4.3%), and 3 aneurysms were only clipped with Peter Lazic (Peter Lazic Microsurgical Innovations, Tuttlingen, Germany) clips (2.6%).

RESULTS

In this cohort, 94.7% of clipped aneurysms had follow-up imaging within 24 hours, and 51.3% had delayed follow-up imaging within 3-12 months. We identified 3 cases of clip slippage in 115 consecutive aneurysm clippings, resulting in an incidence of 2.6%. The average cumulative closing force of clips per aneurysm across the study was 2.32 N, and the median number of clips placed was 1. Two of the 3 cases of clip slippage had a closing force <2.32 N and only placement of a single clip.

CONCLUSIONS

Because our series showed a 2.6% incidence of clip slippage, clipped aneurysms should be monitored with early and delayed vascular follow-up imaging. Lower cumulative clip closing force, single clip placement, and oversized clip blade length may be risk factors for postoperative aneurysmal clip slippage.

Intraoperative Doppler and Duplex sonography in cerebral aneurysm surgery

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Intuitiveness, quality and utility of intraoperative fluorescence videoangiography: Australian Neurosurgical Experience

INTRODUCTION

The authors have undertaken a study of their intraoperative experience with indocyanine green fluorescence videoangiography (ICGFV). In particular, the intuitiveness, image quality and clinical utility of this technology have been assessed.

METHODS

The records of forty-six consecutive craniotomies utilising ICGFV have been retrospectively reviewed: There were 27 aneurysms, 2 extracranial-intracranial (EC-IC) bypasses, 5 arteriovenous malformations (AVM), 1 dural arteriovenous fistula (DAVF), 3 cavernomas, 5 meningiomas, and 3 gliomas. ICGFV was used in 5 awake-craniotomy patients. ICGFV was performed using a Leica OH4 surgical microscope with integrated near-infrared camera and ICG-PULSION.

RESULTS

All attempts of intraoperative ICGFV were intuitive. Image quality and resolution were excellent. Arterial and venous phases were comparable to digital subtraction angiography (DSA) but field of view was relatively limited. In 12 operations (26%) the surgeon was substantially benefited from ICGFV findings. In 22 operations (48%), ICGFV was useful but did not influence surgical management. ICGFV was of no benefit in 11 operations (24%) and was misleading in 1 (2%). In this series, ICGFV was of benefit to 1 of 11 (9%) patients with an intracranial neoplasm or cavernoma.

CONCLUSIONS

ICGFV is safe, intuitive and provides neurosurgeons with high quality, valuable, real-time imaging of cerebrovascular anatomy. It can assist in intraoperative surgical management and/or stroke prevention particularly during aneurysm clipping, EC-IC bypass and AVM/DAVF surgery.

Intraoperative computed tomography angiography with computed tomography perfusion imaging in vascular neurosurgery: feasibility of a new concept

OBJECT

In vascular neurosurgery, there is a demand for intraoperative imaging of blood vessels as well as for rapid information about critical impairment of brain perfusion. This study was conducted to analyze the feasibility of intraoperative CT angiography and brain perfusion mapping using an up-to-date multislice CT scanner in a prospective pilot series.

METHODS

Ten patients with unruptured aneurysms underwent intraoperative scanning with a 40-slice sliding-gantry CT scanner. Multimodal CT acquisition was obtained in 8 patients consisting of dynamic perfusion CT (PCT) scanning followed by intracranial CT angiography. Two of these patients underwent CT angiography and PCT 2 times in 1 session as a control after repositioning cerebral aneurysm clips. In another 2 patients, CT angiography was performed alone. The quality of all imaging obtained was assessed in a blinded consensus reading performed by an experienced neurosurgeon and an experienced neuroradiologist. A 6-point scoring system ranging from excellent to insufficient was used for quality evaluation of PCT and CT angiography.

RESULTS

In 9 of 10 PCT data sets, the quality was rated excellent or good. In the remaining case, the quality was rated insufficient for diagnostic evaluation due to major streak artifacts induced by the titanium pins of the head clamp. In this particular case, the quality of the related CT angiography was rated good and sufficient for intraoperative decision making. The quality of all 12 CT angiography data sets was rated excellent or good. In 1 patient with an anterior communicating artery aneurysm, PCT scanning led to a repositioning of the clip because of an ischemic pattern of the perfusion parameter maps due to clip stenosis of an artery. The subsequent PCT scan obtained in this patient revealed an improved perfusion of the related vascular territory, and follow-up MR imaging showed only minor ischemia of the anterior cerebral artery territory.

CONCLUSIONS

Intraoperative CT angiography and PCT scanning were shown to be feasible with short acquisition time, little interference with the surgical workflow, and very good diagnostic imaging quality. Thus, these modalities might be very helpful in vascular neurosurgery. Having demonstrated their feasibility, the impact of these methods on patients' outcomes has now to be analyzed prospectively in a larger series.

The influence of configuration and location of ruptured distal cerebral anterior artery aneurysms on their treatment modality and results: analysis of our casuistry and literature review

OBJECTIVE

To assess the influence of configuration and location of ruptured distal cerebral anterior artery aneurysms on their treatment modality and results.

METHOD

The influence of the aneurysm configuration (basic or complex configuration) and location (infracallosal or supracallosal) on the treatment-related radiological results (partial or complete aneurysm occlusion) and clinical outcome (favorable or unfavorable) was retrospectively analysed in all admitted patients with ruptured pericallosal aneurysms within the last 10 years. The expected benefit from each form of treatment was individually discussed.

RESULTS

During this period, 21 patients with ruptured pericallosal aneurysms (three previously coiled in other departments) had been admitted to our department. Within the endovascular group (ten patients), five infracallosal basic aneurysms presented a complete occlusion and favorable patient outcome. Three patients with infracallosal complex aneurysms presented a favorable outcome (two aneurysms were partially occluded and a frustrated procedure was replaced by clipping). Two supracallosal basic aneurysms showed a complete occlusion with one unfavorable outcome and one frustrated procedure followed by clipping and favorable outcome. In the surgical group (11 patients), five infracallosal complex aneurysms presented a complete occlusion with four favorable and one unfavorable outcomes. One patient with a supracallosal basic aneurysm presented a complete occlusion with a favorable outcome, and five patients with supracallosal complex aneurysms presented a complete occlusion in four cases and favorable outcome in all of them.

CONCLUSION

The results of this study suggest that patients with infracallosal basic configured aneurysms are expected to benefit from endovascular procedures, whereas better radiological and clinical results can be obtained in surgically treated patients harboring supra- or infracallosal aneurysms of complex configuration.