Lateral supraorbital approach as an alternative to the classical pterional approach

Microsurgical management of anterior communicating artery aneurysms

OBJECTIVE

Aneurysms of the anterior communicating (ACOM) artery are the most frequently occurring type of ruptured intracranial aneurysms. The peculiar anatomy of the anterior communicating artery complex, its anatomic variations, and its multiple perforators, along with the deep location of these aneurysms and our difficulty accessing them, pose challenging anatomic problems in their surgical treatment.

METHODS

We present our operative techniques for microsurgical treatment of ACOM artery aneurysms. Special, complex situations that may arise during treatment of these aneurysms and their solutions are also discussed. We highlight the technical aspects of microsurgical clipping of ACOM artery aneurysms.

RESULTS

Operative videos are provided to illustrate the technical variations of approaching and clipping these aneurysms, the A3-A3 bypass technique, and the complexity of managing these aneurysms.

CONCLUSION

Attention to detail is critical for successful treatment of ACOM artery aneurysms. Management of each patient must be tailored, because no one technique is suitable for all situations. Not all ACOM artery aneurysms can be coiled; therefore, the surgeon's microsurgical clipping technique is an important facet of managing these aneurysms.

Historical landmarks in vascular neurosurgery "On July 10th 2006, at the 70th Anniversary of the Department of Neurosurgery of Zürich Medical School"

Direct aneurysm surgery started more than 70 years ago. Introduction of cerebral angiography by Moniz in 20s and operating microscope by Yaşargil in 60s were the real cornerstones in vascular neurosurgery. Since then the development of neuroanestesiology and further development of non-invasive imaging (MRA and CTA) together with the latest development of operating microscopes with intraoperative ICG angio have shifted vascular microneurosurgery to a different level to still compete with the 'non-invasiness' of endovascular therapy. There is an increasing demand to perform the already forgotten bypasses mastered only by few and with the high-flow techniques (e.g. ELANA) we can treat lesions that some time ago were considered impossible. Endovascular embolization to reduce the flow in AVM before surgery is very helpful in those cases that can not be treated by embolization or radiosurgery alone. We still need to find a way to detect aneurysms before they rupture and especially those thin-walled that are in an increased risk of rupture. Recent data on the pathobiology of the aneurysm wall may help us to better understanding of the growth mechanisms and it might be possible to develop more potent local or systemic pharmaceutical therapy to induce myo-intimal hyperplasia occluding the aneurysm and strengthening the wall to prevent rupture.

Microneurosurgical management of proximal anterior cerebral artery aneurysms

BACKGROUND

Aneurysms originating from the proximal segment of anterior cerebral artery (A1As) are rare, forming less than 1% of all IAs. There are only few reports on microneurosurgical management of A1As. In this article, the authors review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A1As.

METHODS

This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in Southern and Eastern Finland.

RESULTS

These 2 centers have treated more than 10,000 patients with aneurysm since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, there were 23 patients carrying 23 A1As, forming 0.8% of all patients with aneurysm, 0.5% of all aneurysms, and 2% of all ACA aneurysms. Twelve (52%) patients presented with ruptured A1As with ICH in 3 (25%) and IVH in 2 (17%). Seventy percent of patients had at least 1 associated aneurysm.

CONCLUSIONS

Aneurysms arising from A1 are usually small, with a fragile wall. Our data suggest that A1As rupture at smaller size than IAs in general. Because of their small size and involvement of perforating arteries at their base, microneurosurgical clipping is the method of choice in treatment of ruptured A1As. Unruptured A1As also need microneurosurgical clipping even when they are small.

Microneurosurgical management of middle cerebral artery bifurcation aneurysms

BACKGROUND

Of the MCA aneurysms, those located at the main bifurcation of the MCA (MbifA) are by far the most frequent. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MbifAs.

METHODS

This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in southern and eastern Finland.

RESULTS

These 2 centers have treated more than 10,000 patients with intracranial aneurysm's since 1951. In the Kuopio Cerebral Aneurysm Data Base of 3005 patients with 4253 aneurysms, MbifAs formed 30% of all ruptured aneurysms, 36% of all unruptured aneurysms, 35% of all giant aneurysms, and 89% of all MCA aneurysms. Importantly, in 45%, rupture of MbifA caused an ICH.

CONCLUSIONS

Middle cerebral artery bifurcation aneurysms are often broad necked and may involve one or both branches of the bifurcation (M2s). The anatomical and hemodynamic features of MbifAs make them usually more favorable for microneurosurgical treatment. In population-based services, MbifAs are frequent targets of elective surgery (unruptured), acute surgery (ruptured), and emergency surgery (large ICH), even advanced approaches (giant). The challenge is to clip the neck adequately, without neck remnants, while preserving the bifurcational flow.

Microneurosurgical management of distal middle cerebral artery aneurysms

BACKGROUND

Distal middle cerebral artery aneurysms originate from branches of MCA distal to its main bifurcation or the peripheral branches. Distal middle cerebral artery aneurysms are the least frequently seen among the middle cerebral artery aneurysms. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MdistAs.

METHODS

This review, and the whole series on intracranial aneurysms, are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in Southern and Eastern Finland.

RESULTS

These 2 centers have treated more than 10000 aneurysm patients since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, 69 patients carrying altogether 78 MdistAs formed 5% of all MCA aneurysms. Among the 18 patients with ruptured MdistAs (23%), an ICH occurred in 9 (50%).

CONCLUSIONS

Distal middle cerebral artery aneurysms are rare. The microneurosurgical treatment of MdistAs is challenging. They are often difficult to localize during the operation, and lack of collateral circulation makes their occlusion more demanding. High rate of ICH and high tendency of rebleeding urge acute or emergency surgery in most of ruptured cases. Microneurosurgical clipping is the most effective treatment of MdistAs.

Microneurosurgical management of proximal middle cerebral artery aneurysms

BACKGROUND

The M1As are located in the main trunk (M1) of the MCA, between the bifurcation of the ICA and the main bifurcation of M1. Proximal MCA aneurysms are often small and thin-walled, which makes their proper clipping tedious. There are few reports on their microsurgery.

METHODS

This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without selection, the catchment area in the southern and eastern Finland.

RESULTS

These 2 centers have treated more than 10000 patients with aneurysm since 1953. We review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of M1As which form 7.4% of all intracranial and 14% of all MCA aneurysms in our patients.

CONCLUSIONS

Proximal MCA aneurysms are often wide-necked and intimately connected to an M1 branch at its origin on M1, features that favor exosurgery rather than endosurgery. The direction and course of the parent and branching arteries and the orientation of the fundus are the most important factors affecting the efficacy and safety of clipping.

Some collected principles of microneurosurgery: simple and fast, while preserving normal anatomy

Microneurosurgical techniques introduced by Prof Yasargil in the 1960s have increased the neurosurgeon's ability to operate in small and often very narrow and deep gaps. Microneurosurgical techniques-ensuring an almost bloodless field and mostly obviating need for transfusion-should be atraumatic and noninvasive to the already lesioned central nervous system tissues and structures. Instruments in microneurosurgery range from very short to very long and from sturdy to delicate, depending on the working depth, characteristics of tissues, and the microneurosurgical anatomy. However, to keep it simple and fast, and to appreciate normal anatomy, it is preferable to use only a limited array of instruments. Besides the use of instruments and the operating microscope, everything else in the neurosurgical arena should be optimized and professional, such as the positioning of the patient and the conduct of neuroanesthesia. This review of the very basics is distilled from the Helsinki and Kuopio neurosurgery practices in Finland and from the senior author's (JH) experience of close to 10,000 operations, and this is to encourage young neurosurgeons of the world-most of them working with limited resources-to continue to improve their microneurosurgical skills to serve their patients best.