Historical Landmarks in the Management of Aneurysms and Arteriovenous Malformations of the Central Nervous System.

OBJECTIVE: To describe the history of vascular and endovascular neurosurgery. METHODS: A literature research was conducted including historical events from 2000 bc to the twenty-first century ad, and a timetable was filled with information regarding the most representative historical landmarks regarding vascular and endovascular neurosurgery. RESULTS: Starting from approaches limited to the cervical carotid artery, vascular neurosurgery gained its way through the intracranial and finally endovascular space thanks to the introduction of both innovative and progressively less invasive procedures. With the invention of cerebral angiography in 1927, Egas Moniz paved the way for modern endovascular neurosurgery. CONCLUSIONS: Numerous pioneers have been described through this historical reconstruction. Their genius, effort, dedication, and passion brought a massive contribution to vascular and endovascular neurosurgery as we know it today.

Immunohistochemical analysis of a ruptured basilar top aneurysm autopsied 22†years after embolization with Guglielmi detachable coils.

The authors report on the histologic and immunohistochemical analyses of a cerebral aneurysm embolized with platinum coils and with the longest observation period. A 58-year-old woman presenting with subarachnoid hemorrhage due to ruptured basilar top aneurysm was treated with Guglielmi detachable coils (GDC) 22 years ago. She was the 15th case since the GDC was introduced. After she died of unrelated causes, an autopsy and thorough histologic examination were performed. Gross examination revealed no adhesion between the aneurysm wall and the surrounding brain tissue. Histologic and immunohistochemical analyses demonstrated that the cavity of the aneurysm was filled with homogeneous collagenous fibrous tissue, while the neck was completely covered by a dense collagenous neointima and a smooth muscle cell layer. The unique histologic results of this case may contribute to a better understanding of the long-term evolution of the healing process in intracranial aneurysms successfully treated with the GDC.

Immunohistochemical analysis of a ruptured basilar top aneurysm autopsied 22†years after embolization with Guglielmi detachable coils.

The authors report on the histologic and immunohistochemical analyses of a cerebral aneurysm embolized with platinum coils and with the longest observation period. A 58-year-old woman presenting with subarachnoid hemorrhage due to ruptured basilar top aneurysm was treated with Guglielmi detachable coils (GDC) 22 years ago. She was the 15th case since the GDC was introduced. After she died of unrelated causes, an autopsy and thorough histologic examination were performed. Gross examination revealed no adhesion between the aneurysm wall and the surrounding brain tissue. Histologic and immunohistochemical analyses demonstrated that the cavity of the aneurysm was filled with homogeneous collagenous fibrous tissue, while the neck was completely covered by a dense collagenous neointima and a smooth muscle cell layer. The unique histologic results of this case may contribute to a better understanding of the long-term evolution of the healing process in intracranial aneurysms successfully treated with the GDC.

History of the genesis of detachable coils. A review.

The genesis of detachable coils and the background of this genesis are described in this article. To frame the beginning developmental stages of the discovery of detachable coils, the previous extravascular-intravascular and endovascular techniques are presented, as well as the development of the various delivery systems. The experimental studies, initial clinical application, and crucial moment of the conception of detachable coils are also reported.

Endovascular treatment of 306 anterior communicating artery aneurysms: overall, perioperative results.

OBJECT: A series of 306 consecutive patients with an anterior communicating artery (ACoA) aneurysm is presented. The goal in this study was to report the results of endovascular treatment of ACoA aneurysms in these patients. METHODS: The aneurysms were managed with an endovascular approach in which detachable coils were used. A brief anatomical description of the ACoA and its branches as well as a review of the surgical and endovascular literature is presented. The "ACoA Syndrome" (that is, amnesia and personality changes), which may occur after subarachnoid hemorrhage, is briefly reviewed and described. Recent technical developments that can lead to improved results are also discussed. RESULTS: Of the 306 aneurysms, 268 (87.5%) were small, 30 (10%) were large, and 8 (2.6%) were giant. One hundred ninety-three aneurysms (63%) had a small neck, whereas 113 (37%) had a wide neck. Sixty-five lesions (21%) were incidental, 5 (2%) presented with symptoms of mass effect, and 236 (77%) presented with a subarachnoid hemorrhage. A complete aneurysm occlusion was attained in 139 cases (45.5%), a neck remnant was detected in 145 (47.5%), and in 22 cases (7%) a residual filling of the aneurysm was observed. Regarding the clinical neurological outcome, 280 patients (91.5%) remained neurologically intact, improved, or unchanged from their initial clinical status. Two large, wide-necked, subtotally occluded aneurysms ruptured 3-7 months after the procedure, with subsequent death of the patients. The procedure-related morbidity and mortality rates were 3.5% (11 cases) and 1% (3 cases), respectively. CONCLUSIONS: The inherently lower risk of injuring or occluding the delicate branches and perforating vessels arising from the ACoA makes the endovascular approach attractive, interesting, and elegant.

Analysis of the hemodynamic characteristics of brain arteriovenous malformations using electrical models: baseline settings, surgical extirpation, endovascular embolization, and surgical bypass.

OBJECTIVE: The goal of this report is to analyze the hemodynamic characteristics of low- and high-flow arteriovenous malformations (AVM) using computerized electrical models. METHODS: Two electrical models of brain AVMs were created. These models consist of electrical resistors that simulate AVM vessels. In both models, a low-flow AVM and a high-flow AVM, the flow of electrons simulates the flow of blood. RESULTS: Using the models, it was possible to analyze the pressure and flow patterns in the nidus of the small, low-flow AVM and in the nidus of the large, high-flow AVM. Baseline hemodynamic "physiological" conditions of the two AVMs were studied. With the models, it was also possible to assess the AVM hemodynamic changes (in the feeding arteries, in the various parts of the nidus, and in the draining veins) after surgery, after embolization, and after surgical bypass of the malformation. The role of autoregulation in the three treatment modalities was also assessed. CONCLUSION: These electrical models seem to be useful in simulating and studying the behavior of flow and pressure in the different parts of the AVM nidus (arterial, arteriolar, arteriolar-venular, venular, venous) before and after treatment. The models can also be used to devise and simulate new treatment strategies that might lead to improved treatment of these highly complex vascular malformations of the brain.

The Guglielmi detachable coil "crescent" in the endovascular treatment of peripheral brain aneurysms: technical case report.

OBJECTIVE: Peripheral brain aneurysms arise from the distal segments of cerebral arteries. They can be treated by surgery or by an endovascular approach. We present our experience of endovascular treatment of peripheral brain aneurysms with a novel endovascular device, the Guglielmi detachable coil (GDC) "crescent." METHODS: The GDC "crescent" is a 5-mm long, curved coil steerable beyond the tip of a microcatheter and detachable at a distance. The GDC "crescent" was used in three cases of intracranial peripheral aneurysms to occlude their parent vessel. RESULTS: Three peripheral brain aneurysms in three patients were successfully treated with parent vessel occlusion using the prototype GDC "crescent" coils, thereby excluding the aneurysms from the brain circulation. No complications were encountered. CONCLUSION: From this limited experience, the GDC "crescent" seems particularly suitable for the controlled endovascular occlusion of the often-narrow parent artery of distal brain aneurysms.

Bypass combined with embolization via a venous graft in a patient with a giant aneurysm in the posterior communicating artery and bilateral idiopathic occlusion of the internal carotid artery in the neck.

The authors describe the case of a patient with a symptomatic giant aneurysm of the posterior communicating artery (PCoA) associated with bilateral idiopathic occlusion of the internal carotid artery (ICA). The presence of severe tortuosity of the vertebral arteries (VAs), both at their origin from the subclavian artery and at the level of the third segment, impeded navigation of the catheter for embolization of the aneurysm with Guglielmi detachable coils (GDCs). A direct surgical approach was considered to be a high-risk procedure because of the bilateral occlusion of the ICAs and the size of the aneurysm. The following therapeutic strategy was therefore adopted: 1) balloon occlusion test of the left VA; 2) vertebro-vertebral bypass with saphenous vein graft to provide a pathway for subsequent embolization; 3) ICA-left middle cerebral artery bypass to ensure blood flow in the event that embolization resulted in closure of the PCoA; and 4) GDC embolization of the aneurysm via the posterior circulation graft to ensure complete exclusion of the lesion from the arterial circulation and preservation of the PCoA. At 3-month follow-up review the patient did not present with any neurological deficits; at 1-year control examination, magnetic resonance (MR) imaging and MR angiography both confirmed complete exclusion of the aneurysm and patency of the two bypasses.