Commentary for recurrent intracranial aneurysms after successful neck clipping

Frequency and risk factors for postoperative aneurysm residual after microsurgical clipping

OBJECTIVE

Aneurysm residuals after clipping are a well-known problem, but the course of aneurysm remnants in follow-up is not well studied. No standards or follow-up guidelines exist for treatment of aneurysm remnants. The aim of this study was to evaluate the risk factors for postoperative aneurysm remnants and their changes during follow-up.

METHODS

We performed a retrospective analysis of 666 aneurysms treated via clipping in our hospital from 2006 to 2016. Postoperative and follow-up angiographic data were analyzed for aneurysm remnants and regrowth. Clinical parameters and aneurysm-specific characteristics were correlated with radiological results.

RESULTS

The frequency of aneurysm residuals was 12% (78/666). Aneurysms located in the middle cerebral artery (p = 0.02) showed a significantly lower risk for incomplete aneurysm occlusion. Larger aneurysms with a diameter of 11-25 mm (p = 0.005) showed a significantly higher risk for incomplete aneurysm occlusion. Five patients underwent re-clipping during the same hospital stay. Remnants were stratified based on morphological characteristics into "dog ears" (n = 60) and "broad based" (n = 13). The majority of the "dog ears" stayed stable, decreased in size, or vanished during follow-up. Broad-based remnants showed a higher risk of regrowth.

CONCLUSIONS

A middle cerebral artery location seems to lower the risk for the incomplete clip occlusion of an aneurysm. Greater aneurysm size (11-25 mm) is associated with a postoperative aneurysm remnant. The majority of "dog-ear" remnants appear to remain stable during follow-up. In these cases, unnecessarily frequent angiographic checks could be avoided. By contrast, broad-based residuals show a higher risk of regrowth that requires close imaging controls if retreatment cannot be performed immediately.

The classification of intracranial aneurysm neck: a single center research experience

BACKGROUND

There is associating with incidence of unfavorable outcomes compared to microsurgical clippings. We are in order to investigate the outcomes of microsurgical clipping for intracranial aneurysms and determine the ideal clipping methods for different aneurysm subtypes.

METHOD

Retrospectively analyzed the clinical characteristics and follow-up data (completely recorded) of 123 patients with 128 aneurysms were treated. 20 cases were treated as control group from October 2013 to December 2013. Since January 2014, aneurysms were classified base on the 20 cases of aneurysm imaging data. 103 patients were treated as experimental group, the classification of aneurysms previously proposed was used to estimate the way of surgery, and the guiding value of the genotype was verified according to the intraoperative findings. The proposed aneurysm classification is based on the virtual surface of the aneurysm and the parent artery, the aneurysm neck was classified as follows: subtype I, the curved surface of the neck is a single curved surface; subtype II, the neck is hyperboloid; subtype III, neck is a three-curved surface. Aneurysms were divided into further subtypes according to the ratio of the width of the aneurysm neck surface and the length of the artery circumference: subtype A, the ratio of the aneurysm neck surface to the parent artery was not more than 0.5; subtype B, more than 0.5. There are some clamping methods include simple, sliding, interlocking and hybrid.

RESULTS

In the control group, patients did not undergo a suitable clipping scheme without classification of aneurysm neck (unclassed clipping). While causing the occurrence of occlusion adverse events, including neck residual, Tumor artery stenosis, electrophysiological changes, the lack of blood supply and so on. The experimental[page1image12073600]group was analyzed by using a predetermined clipping scheme (classed clipping), and the use of aneurysms clamps was approximately the same as expected. Compared the preoperative assessment with the actual situation, the consistency of the control group was 50% and the experimental group was 96%. Adverse events of classed clipping is 2%, another is 60%. There is a significant difference between the two groups (P < 0.05).Classed clipping of subject IA and IB are simple (mean 1.2 and 1.3 clips); classed clipping of subject IIA is simple and interlocking(mean 1.2 clips); classed clipping of subject IIB is sliding and hybrid(mean 2.05 clips); classed clipping of subject IIIA and IIIB are hybrid(mean 2.3 clips).

CONCLUSION

There is a higher consistency in surgery through the above classification of preoperative assessment of clipping. There was no adverse event of intracranial aneurysm clipping in the clipping mode selected by the above classification, and satisfactory surgical clipping rate was achieved and no recurrence was found.