✓ This report presents two cases of hypervascular tumor in which the cavernous and petrous internal carotid artery feeding vessels were successfully occluded using a new endovascular device, the crescent-shaped platinum Guglielmi detachable coil (GDC). With this new embolic agent the risk of unwanted embolization of normal intracranial arteries was significantly reduced. The GDC “crescent” seems particularly useful when distal, superselective, and controllable occlusion of small arterial feeding vessels is the goal of the treatment.
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.
Part 1: Electrochemical basis, technique, and experimental results
Guido Guglielmi, Fernando Viñuela, Ivan Sepetka, and Velio Macellari
✓ Eleven experimental saccular aneurysms were created on the common carotid artery of swine. Between 3 and 15 days after creation of these aneurysms, they were thrombosed via an endovascular approach, using a very soft detachable platinum coil delivered through a microcatheter positioned within the aneurysm. This detachable platinum coil was soldered to a stainless steel delivery guidewire. Intra-aneurysmal thrombosis was then initiated by applying a low positive direct electric current to the delivery guidewire. Thrombosis occurred because of the attraction of negatively charged white blood cells, red blood cells, platelets, and fibrinogen to the positively charged platinum coil positioned within the aneurysm. The passage of electric current detached the platinum coil within the clotted aneurysm in 4 to 12 minutes. This detachment was elicited by electrolysis of the stainless steel wire nearest to the thrombus-covered platinum coil. Control angiograms obtained 2 to 6 months postembolization confirmed permanent aneurysm occlusion as well as patency of the parent artery in all cases. No angiographic manifestation of untoward distal embolization was noted. Due to the encouraging results of this research, this technique has been applied in selected clinical cases which are described in Part 2 of this study.
Part 2: Preliminary clinical experience
Guido Guglielmi, Fernando Viñuela, Jacques Dion, and Gary Duckwiler
✓ Fifteen patients with high-risk intracranial saccular aneurysms were treated using electrolytically detachable coils introduced via an endovascular approach. The patients ranged in age from 21 to 69 years. The most frequent clinical presentation was subarachnoid hemorrhage (eight cases). Considerable thrombosis of the aneurysm (70% to 100%) was achieved in all 15 patients, and preservation of the parent artery was obtained in 14. Although temporary neurological deterioration due to the technique was recorded in one patient, no permanent neurological deficit was observed in this series and there were no deaths. It is believed that this new technology is a viable alternative in the management of patients with high-risk intracranial saccular aneurysms. It may also play an important role in the occlusion of aneurysms in the acute phase of subarachnoid hemorrhage.
Guido Guglielmi, Giulio Guidetti, Stefania Mori, and Pasquale Silipo
✓ The authors report a case of an arteriovenous fistula between the ascending pharyngeal artery and the internal jugular vein. The importance of an exact diagnosis and some precautions to be taken during therapeutic embolization are emphasized, as well as the need for superselective cannulation of the feeding artery. The problem of differential diagnosis with glomus tumors is discussed, and a brief mention is made of the anatomy of the jugular foramen and embryology of these tumors. Only one similar case treated by embolization with solid particles was found in the literature. To date, embolization using solid particles rather than liquid agents appears to be the best treatment of fistulas of this type.
Motoharu Hayakawa, Yuichi Murayama, Gary R. Duckwiler, Y. Pierre Gobin, Guido Guglielmi, and Fernando Viñuela
Object. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms is still unknown. The purpose of this study was to evaluate the anatomical evolution of neck remnants in aneurysms treated with GDCs.
Methods. Of 455 aneurysms treated with GDCs from 1990 to 1998 at the University of California at Los Angeles Medical Center, 178 aneurysms (39%) had residual necks postembolization. Long-term follow-up angiograms were obtained in 73 of these aneurysms in 71 patients. The mean duration of angiographic follow up was 17.3 months. Twenty-four of the aneurysms were small with small necks, 24 were small with wide necks, 15 were large, and 10 were giant aneurysms.
In small aneurysms with small necks, postembolization angiography revealed 12 aneurysms (50%) with progressive thrombosis, eight (33%) unchanged, and four (17%) with recanalization. In small aneurysms with wide necks, six (25%) had progressive thrombosis, eight (33%) remained unchanged, and 10 (42%) had recanalization. In large aneurysms, two (13%) were unchanged and 13 (87%) had recanalization. Of the giant aneurysms only one (10%) remained unchanged and nine (90%) had recanalization. Overall, 18 aneurysms (25%) exhibited progressive thrombosis, 19 (26%) remained unchanged, and 36 (49%) displayed recanalization on follow-up angiography. During the last 2 years of the study, the recanalization rate decreased and a higher rate of progressive thrombosis was noted in aneurysms with small necks. These positive changes are related to important new technical developments.
Conclusions. Treatment with GDCs appears to be effective and the results permanent in most small aneurysms with small necks. However, there are important technical limitations in the current GDC technology that prevent recanalization in wide-necked or large or giant aneurysms.
Antonio Santoro, Emiliano Passacantilli, Giulio Guidetti, Mauro Dazzi, Guido Guglielmi, and Giampaolo Cantore
✓ 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.