Large paraclinoid aneurysm with a calcified neck treated by tailored multimodality procedures

A 68-year-old woman presented with a large paraclinoid aneurysm with a calcified neck causing visual symptoms. Direct clipping was hazardous because of severe calcification of the neck. Endovascular internal trapping was difficult because of the short distance between the neck and the origin of the posterior communicating artery. Proximal occlusion was likely to be less effective because of large collateral back flow to the aneurysm via the ophthalmic artery (OphA). The aneurysm was successfully treated by a combination of a high-flow bypass, intraoperative coil embolization of the parent artery including the origin of the OphA, and clipping of the internal carotid artery distal to the aneurysm. Paraclinoid aneurysms may be difficult to treat by the simple application of direct clipping, endovascular coiling, or trapping. Multimodality procedures can be tailored to treat such aneurysms.     

Intraoperative endovascular treatment as an adjunct to microsurgical clipping of paraclinoid aneurysms

OBJECT: The endovascular procedure can provide proximal control, suction decompression, and prompt intraoperative angiography during microsurgical clipping of aneurysms of the paraclinoid segment of the internal carotid artery (ICA). The authors assess the safety and feasibility of this method in 24 consecutive cases. METHODS: Frontotemporal craniotomy and radical pterionectomy were performed with the patient's head immobilized in a radiolucent frame while femoral artery catheterization was achieved. Before dural opening, a balloon catheter with a coaxial lumen was positioned and tested in the ICA, after which microsurgical exposure was completed, including intradural clinoid drilling and optic canal decompression. Trapping of the lesion was achieved by inflating the balloon and placing a temporary clip beyond the aneurysm neck. The catheter was gently aspirated to achieve suction decompression and to facilitate clip application. Intraoperative digital subtraction angiography was then performed. Twenty-two aneurysms were larger than 10 mm, and 11 of them were giant. Six patients presented with subarachnoid hemorrhage and nine with visual symptoms. Balloon occlusion and suction decompression were performed in 16 cases (67%), and proximal control alone in 1 case. Intraoperative angiography was performed in every case. Subsequent clip readjustment was necessary in seven cases, including three cases of residual aneurysm filling and four of ICA compromise. Complete aneurysm obliteration was achieved in 20 cases, and greater than 90% obliteration in 22. One major infarct likely related to catheter thromboembolism was found. There were no instances of visual deterioration or other complications attributable to the endovascular procedure. CONCLUSIONS: The endovascular method allows safe and reliable proximal control, suction decompression, and intraoperative angiography in microsurgical treatment of large paraclinoid aneurysms.     

Temporary balloon occlusion of a proximal vessel as an aid to clipping aneurysms of the basilar and paraclinoid internal carotid arteries: technical note

One aneurysm of the basilar artery and three large, paraclinoid aneurysms of the internal carotid artery (ICA) were treated with the aid of intraoperative temporary balloon occlusion of the vessel. Optimal clip placement was confirmed using intraoperative angiography. This technique provided excellent proximal vascular control and for the large aneurysms of the paraclinoid ICA obviated the need for surgical exposure of the ICA in the neck. We think this is a useful adjunct in the surgical management of aneurysms of both the basilar artery and proximal ICA.     

Open surgery of giant paraclinoid aneurysms improved by intraoperative angiography and endovascular retrograde suction decompression

Summary In three consecutive cases of giant left sided paraclinoid aneurysms we employed an endovascular retrograde suction decompression technique in combination with intra-operative angiography. A double-lumen balloon catheter was placed in the left internal carotid artery by the transfemoral route. After balloon inflation and placement of a temporary clip distal to the aneurysm blood was aspirated and the aneurysm collapsed. Thus further dissection of the aneurysm could easily be achieved and clips could be placed. Afterwards real-time digital subtraction angiography was performed. Intra-operative angiography led to clip repositioning in all cases either due to a clip induced stenosis of the parent vessel, or because of incomplete aneurysm obliteration. Afterwards successful clipping could be confirmed in all cases. Outcome was excellent in one case, good in the other. The third case, extremely complicated by an accompanying craniopharyngioma, showed a satisfactory outcome, but presented new neurological deficits.     

Combined endovascular and microsurgical approach in the treatment of giant paraclinoid and vertebrobasilar aneurysms

AIM: The aim of this study is to present the application of endovascular intraoperative occlusion of the parent artery during the microsurgical treatment of giant paraclinoidal internal carotid artery aneurysms (ICA) and of complex vertebrobasilar junction aneurysms . METHODS: Five cases of giant paraclinoidal ICA aneury-sms were treated by direct surgical approach. In the operatory room any patient underwent angiography and balloon occlusion test using a mobile digital subtraction angiograph. Thereafter the catheter was left in the aortic arch. Through an extended pterional craniotomy, it was possible to evidentiate the aneurismal sac. The proximal control of the vessel was achieved inflating a double-lumen balloon; clipping of the aneurysm was achieved, because of pressure lowering inside the aneurysm. Also a giant vertebrobasilar junction aneurysm was treated by this combined technique: using a posterolateral approach the control of the omolateral vertebral artery was obtained by temporary clipping above PICA's origin; the control of controlateral artery was obtained inflating a balloon introduced through the femoral artery. These combined manoeuvres determined sac deflation, allowing an easier clipping. RESULTS: Aneurysm obliteration was achieved with preservation of the circulation without complications in all cases. CONCLUSIONS: The endovascular procedure allows safer and reliable proximal control of paraclinoidal ICA and vertebral artery during the microsurgical treatment of paraclinoid and vertebrobasilar junction aneurysms.     

Angioscopy-assisted aneurysm clipping.

OBJECTIVE: To test the concept that endovascular angioscopy can assist surgical intracranial aneurysm clipping by providing an endoluminal view of the aneurysm-parent vessel complex. METHODS: A carotid bifurcation aneurysm was surgically created in a dog at the lingual artery origin. A balloon catheter was inflated proximal to the aneurysm to block proximal blood flow and allow endoluminal visualization. A flexible angioscope connected to a video monitoring system and to a high-intensity light source was then advanced within the catheter lumen and positioned immediately distal to the catheter tip. The aneurysm neck was clipped, and the clip was repositioned several times along the neck, with or without distal parent vessel compromise. Each time, the endovascular image on the monitor was interpreted by an observer blinded to the position of the clip. Clip position and image interpretation were communicated independently to a third person, who analyzed the correlation between them. RESULTS: Angioscopy allowed clear visualization of the extent of aneurysm neck occlusion (complete, incomplete, residual "dog ear") after clip application, as well as the presence or absence of distal parent vessel compromise. Aneurysm neck configuration, size, presence of thrombus, and suture line definition were depicted. Critical structures external to the aneurysm-parent vessel complex were transilluminated by the high-intensity lamp. CONCLUSION: Although acknowledged as the treatment of choice for intracranial aneurysms, surgical exclusion can be accompanied by significant morbidity related to perforator occlusion, parent artery compromise, and/or persistent residual aneurysm. The availability of a device allowing visualization of an aneurysm from an endoluminal perspective theoretically could reduce the incidence of these complications. Angioscopy has the potential to become a useful adjunct during intracranial aneurysm clipping because it provides real-time endoluminal viewing of the aneurysm-distal parent vessel complex, which is sometimes obscured to the surgeon.     

Retrograde suction decompression of giant paraclinoid aneurysms using a No. 7 French balloon-containing guide catheter. Technical note

The treatment of large and giant paraclinoid carotid artery (CA) aneurysms often requires the use of suction decompression for safe and effective occlusion. Both open and endovascular suction decompression techniques have been described previously. In this article the authors describe a revised endovascular suction decompression technique that provides several advantages in the treatment of large and giant paraclinoid and CA aneurysms. A 51-year-old woman presented with a relatively brief history of progressive visual loss in the right eye, nonspecific headache, and an afferent pupillary defect. After angiography studies had been obtained, it was determined that she had a giant right paraclinoid internal CA aneurysm with a dome size of approximately 26 mm on the right and a neck diameter of 10 mm. A modified technique was performed in which suction decompression was used. With the aid of a No. 7 French Concentric balloon guide catheter (Concentric Medical, Inc., Mountain View, CA) and application of a temporary clip distal to the aneurysm, the aneurysm was trapped and decompressed using retrograde suction through the guide catheter when the balloon was inflated. After satisfactory placement of three permanent clips, an intraoperative angiogram obtained through the same guide catheter confirmed CA patency. The aneurysm was then punctured and aspirated, ensuring complete occlusion of the aneurysm sac and reconstruction of the parent vessel. The patient made an excellent recovery and did not suffer any complications. She did not experience worsening in her vision. This technical modification to endovascular suction decompression allows several potential advantages, including higher volume decompression and the ability to deliver endovascular devices to distal arterial locations.     

A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms

BACKGROUND The treatment of giant and large paraclinoid aneurysms remains challenging. To improve exposure, facilitate the dissection of aneurysms, assure vascular control, reduce brain retraction and temporary occlusion time, enable simultaneous treatment of associated lesions, and achieve more successful treatment of “difficult” (atherosclerotic and calcified) aneurysms, we combined the skull-base approach with endovascular balloon occlusion of the internal carotid artery (ICA) and suction decompression of the aneurysm.

METHODS Sixteen female patients were treated, eight with giant aneurysms and eight with large aneurysms. Eight aneurysms occurred on the right side and eight on the left. Eight patients had an additional aneurysm; five were clipped during the same procedure. Three patients had infundibular arterial dilation. One patient had an associated hemangioma of the ipsilateral cavernous sinus. The cranio-orbital-zygomatic approach was used for all patients. The anterior clinoid was drilled, and the optic nerve was decompressed, dissected, and mobilized. Transfemoral temporary balloon occlusion of the ICA in the neck was followed by placement of a temporary clip proximal to the posterior communicating artery. Suction decompression was then applied. All aneurysms were then successfully clipped, except one that had a calcified neck and wall that could not be collapsed. Intraoperative angiography performed in 13 of 15 patients with clipped aneurysms confirmed obliteration of the aneurysm and patency of the blood vessels.

RESULTS Postoperative results were good in 14 patients. One patient had right-sided hemiplegia and expressive aphasia, which improved after rehabilitation. One patient with an additional basilar tip aneurysm clipped simultaneously died on the fifth postoperative day because of intraventricular hemorrhage. The origin of bleeding could not be determined on autopsy. Surgical difficulties and morbidity stemmed mainly from a severely calcified or atherosclerotic aneurysmal neck.

CONCLUSION The combination of skull-base approaches and endovascular balloon occlusion coupled with suction decompression is a successful option for the treatment of these challenging aneurysms.     

A case of aneurysmal neck clipping following incomplete neck clipping and coil embolization

We report a case with radical neck clipping following incomplete embolization with coils and imperfect neck clipping. A 43-year-old woman suffered from a subarachnoid hemorrhage (Hunt & Hess Grade IV) due to the rupture of a left paraclinoid internal carotid aneurysm on 28 October, 1996. Neck clipping of the aneurysm was performed at day 1. Follow-up angiogram at 2 weeks after surgery showed however a small residual aneurysm. The second angiogram 1.5 months later showed the growth of the residual aneurysm. The residual part of the aneurysm was then treated with endovascular embolization using interlocking detachable coils (IDC), resulting in incomplete occlusion of the aneurysm. The direct surgical clipping of the residual aneurysm was performed via Dolenc approach. A fenestrated clip was applied to the partial embolized aneurysm, when the aneurysmal wall was ruptured between the occluded part of the aneurysm and the residual dome. The fenestrated clip was then reapplied successfully under temporary occlusion of the parent artery. Because of the stenosis of the parent artery, STA-MCA anastomosis was then performed. Postoperative recovery of the patient was uneventful and postoperative angiogram showed stenosis of the parent artery with patent bypass flow. The patient was discharged without complications. Technical problems in neck clipping following incomplete embolization with coils are discussed.     

Endovascular treatment of giant and large intracranial aneurysms by using a combination of stent placement and liquid polymer injection

OBJECT: The aim of this study was to test the feasibility, safety, and efficacy of a new endovascular method for the treatment of giant intracranial aneurysms. This new method consists of combining a metallic stent with a liquid polymer; the stent is first placed across the neck of the aneurysm to reconstruct a tubular arterial lumen, followed by obliteration of the fundus of the aneurysm with an ethyl vinyl alcohol polymer. During its injection, the liquid polymer is contained within the aneurysm by temporarily inflating an occlusion balloon in the parent artery. METHODS: Eleven patients harboring a giant aneurysm were successfully treated using this procedure. All aneurysms were excluded from the circulation, with preservation of the parent artery. In nine of the 11 patients, the 6-month follow-up angiogram demonstrated no recanalization of the aneurysm. In one patient who had a giant and partially clotted internal carotid artery bifurcation aneurysm, the follow-up angiogram demonstrated minimal recanalization. The complications in this series of patients included one death and one case of transient hemiparesis caused by watershed ischemia. CONCLUSIONS: The initial anatomical results and the clinical outcome in this small series of patients are very encouraging. The mortality and morbidity rates associated with this new endovascular treatment are superior to those associated with surgical clipping of giant aneurysms.     

Direct surgery for paraclinoid aneurysm arising from the anterolateral wall of the internal carotid artery

The internal carotid aneurysm (ICA) arising from the paraclinoid region is associated with the origins of the superior hypophyseal artery and the ophthalmic artery. Recently, other aneurysms which can arise in this region without imvolvement of the arterial branches has been reported. Among those aneurysms, there are very rare type of aneurysms located on the anterolateral aspect of the internal carotid artery. In this report, we described our experience with direct surgery for five cases of the unruptuted paraclinoid aneurysm arising from the anterolateral aspect of the ICA. Firstly, the common carotid artery was exposed to carry out proximal flow control. We used the pterional approach. The anterior clinoid process was deleted after having confirmed aneurysm and the dural ring was incised. Extreme care had to be taken during this step. All patients underwent successful neck clipping. In recent two cases we employed the neuroendoscope (EndoArm) to observe the unrecognized area of surgical microscope and untrasonic bone curette (SONOPET) to perform the safe removal of the anterior clinoid process. This procedure is very useful for carrying out the neck clipping for aneurysms which are located on the anterolateral aspect of the internal carotid artery.     

Efficacy and current limitations of intravascular stents for intracranial internal carotid, vertebral, and basilar artery aneurysms.

OBJECT: Results of previous in vitro and in vivo experimental studies have suggested that placement of a porous stent within the parent artery across the aneurysm neck may hemodynamically uncouple the aneurysm from the parent vessel, leading to thrombosis of the aneurysm. For complex wide-necked aneurysms, a stent may also aid packing of the aneurysm with Guglielmi detachable coils (GDCs) by acting as a rigid scaffold that prevents coil herniation into the parent vessel. Recently, improved stent system delivery technology has allowed access to the tortuous vascular segments of the intracranial system. The authors report here on the use of intracranial stents to treat aneurysms involving different segments of the internal carotid artery (ICA), the vertebral artery (VA), and the basilar artery (BA). METHODS: Ten patients with intracranial aneurysms located at ICA segments (one petrous, two cavernous, and three paraclinoid aneurysms), the VA proximal to the posterior inferior cerebellar artery origin (one aneurysm), or the BA trunk (three aneurysms) were treated since January 1998. In eight patients, stent placement across the aneurysm neck was followed (immediately in four patients and at a separate procedure in the remaining four) by coil placement in the aneurysm, accomplished via a microcatheter through the stent mesh. In two patients, wide-necked aneurysms (one partially thrombosed BA trunk aneurysm and one paraclinoid segment aneurysm) were treated solely by stent placement; coil placement may follow later if necessary. No permanent periprocedural complications occurred and, at follow-up examination, no patient was found to have suffered symptoms referable to aneurysm growth or thromboembolic complications. Greater than 90% aneurysm occlusion was achieved in the eight patients treated by stent and coil placement as demonstrated on immediate postprocedural angiograms. Follow-up angiographic studies performed in six patients at least 3 months later (range 3-14 months) revealed only one incident of in-stent stenosis. In the four patients originally treated solely by stent placement, no evidence of aneurysm thrombosis was observed either immediately postprocedure or on follow-up angiographic studies performed 24 hours (two patients), 48 hours, and 3 months later, respectively. CONCLUSIONS: A new generation of flexible stents can be used to treat complex aneurysms in difficult-to-access areas such as the proximal intracranial segments of the ICA, the VA, or the BA trunk. The stent allows tight coil packing even in the presence of a wide-necked, irregularly shaped aneurysm and may provide an endoluminal matrix for endothelial growth. Although convincing experimental evidence suggests that stent placement across the aneurysm neck may by itself promote intraluminal thrombosis, the role of this phenomenon in clinical practice may be limited at present by the high porosity of currently available stents.     

Treatment of peripheral aneurysms of the posterior circulation

Peripherally located aneurysms of the posterior circulation are extremely rare. The outcome of patients with peripherally located aneurysms has been poor, and the treatment of such aneurysms has been surgically challenging. We report a consecutive series of peripherally located ruptured aneurysms in the posterior circulation, and discuss in this article the optimal treatment strategy for such lesions. Clinical presentation, neuroradiological findings, treatment method, and the outcome were reviewed retrospectively. Two cases with distal posterior cerebral artery aneurysm, two with distal posterior inferior cerebellar artery aneurysm, two with anterior inferior cerebellar aneurysm, and one with superior cerebellar artery aneurysm were included in this study (mean age, 59.3 +/- 16.0, M:F = 1:6). Three patients with good neurological status on admission who underwent clipping of the aneurysmal neck via craniotomy showed a favorable outcome. In contrast, four patients with poor neurological status on admission who underwent endovascular proximal occlusion of the parent artery showed an unfavorable outcome. Although the outcome of patients who underwent endovascular surgery was poor, endovascular proximal occlusion was effective in preventing re-rupture of the aneurysms. Proximal occlusion of the parent artery has several shortcomings such as cerebral infarction, but proximal occlusion at the very distal area of the parent arteries would not be critical because of good collateral circulation. Thus, endovascular proximal occlusion may provide us another option in the treatment of peripherally located aneurysms especially in patients with poor neurological status. Further data is needed to discover the optimal treatment for patients with peripherally located cerebral aneurysms.     

The balloon anchor technique: a novel technique for distal access through a giant aneurysm

A novel technique is reported that helps the operator in achieving reliable access to the distal parent vessel with a microcatheter for stent assisted aneurysm coiling. Distal parent vessel access was obtained by allowing the microwire to follow the local hemodynamics into a giant internal carotid artery aneurysm and around its dome. Various traditional methods were tried before attempting the balloon anchor. In this technique, an over-the-wire balloon was inflated in the distal vessel followed by gentle retraction of the balloon catheter and microwire allowed only a wire bridge across the aneurysm neck, thereby allowing the stent catheter to be brought up in a standard fashion. This technique may facilitate the use of new stent technologies for the treatment of aneurysms that would otherwise be untreatable with endovascular therapies.     

Balloon-assisted coil placement in wide-necked cerebral aneurysms: preliminary clinical experience

Endovascular treatment of wide-necked cerebral aneurysms with Guglielmi detachable coils (GDCs) has been limited due to coil protrusion into the artery. Seven patients with wide-necked cerebral aneurysms were treated with GDCs with temporary balloon inflation for mechanical protection during coil placement. Transarterial embolization of the aneurysm with GDCs had failed due to coil protrusion into the parent artery. The use of simultaneous temporary balloon protection achieved more dense intra-aneurysmal coil packing, especially in the neck, without compromising the parent artery.     

Simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery aneurysms

OBJECT: The authors of this study evaluated the efficacy of simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery (ICA) aneurysms. METHODS: The endoscopic technique was applied during microsurgery in 11 patients with 13 aneurysms. Nine of these lesions were located on the posterior communicating artery (PCoA), three in the paraclinoid region, and one on the anterior choroidal artery (AChA). Eight patients had unruptured aneurysms and three had ruptured aneurysms. The endoscope was introduced after first exposing the aneurysm through the microscope and was gripped firmly by an airlocked holding arm fitted with a steering system throughout the entire surgery, including dissection of the perforating arteries and application of the aneurysm clips. Regarding paraclinoid aneurysms, clips were applied through direct visualization of the ophthalmic artery and the proximal neck. In a case involving a superior hypophyseal artery aneurysm in the paraclinoid segment, a ring clip was applied without removing the bone structure around the optic canal. In all aneurysms of the PCoA and the AChA, perforating arteries behind the lesion were identified and dissected using endoscopic control. The aneurysm clip was applied in the best position in a single attempt in 10 of 11 patients. There was no surgical complication related to the endoscopic procedures. CONCLUSIONS: Simultaneous monitoring with the microscope and endoscope is extremely useful in applying clips to ICA aneurysms. This combined method allows for direct dissection of the aneurysm, perforating vessels, and the main trunk in an area not visible through the microscope's eyepiece and promises better surgical results.     

Ruptured anterior paraclinoid aneurysms

The purpose of this study was to evaluate cases of subarachnoid hemorrhage (SAH) from ruptured anterior (dorsal) paraclinoid aneurysms. Anterior paraclinoid aneurysms are defined as aneurysms arising from the anterolateral wall of the proximal internal carotid artery without any relationship to an arterial branch. Between 1991 and 2008, a total of 159 patients with 169 paraclinoid aneurysms were treated at the Shinshu University Hospital and its affiliated hospitals. A retrospective analysis was carried out using charts, operation records, operation videos, and neuroimagings. Twenty six patients had anterior paraclinoid aneurysm. Six patients presented with SAH. Three aneurysms were saccular and the others were blister-like aneurysms based on operative findings. Neck laceration or premature rupture frequently happened during the clipping surgery even though the aneurysm was saccular type. The treatment of a ruptured anterior paraclinoid aneurysm is quite difficult. Trapping and bypass would be recommended for such fragile aneurysms.     

Unruptured paraclinoid aneurysms: a management strategy

OBJECT: To elucidate an optimal managenent strategy for unruptured paraclinoid aneurysms, the authors retrospectively reviewed their experience in the treatment of 100 patients who underwent 112 procedures for111 paraclinoid aneurysms performed using direct surgery and/or endovascular treatment. METHODS: Between 1997 and 2002, 111 unruptured paraclinoid aneurysms categorized according to a modified al-Rodhan classification (Group la, 30 anterior wall lesions; Group lb, 25 ventral paraclinoid lesions; Group IL 18 true ophthalmic artery lesions; Group III, 37 carotid cave lesions; and Group IV, one transitional lesion) were treated by direct surgery (35 lesions) and/or endovascular treatment (77 lesions) (one aneurysm was treated by both procedures). In lesions in Groups Ia, Ib, II, and III that were treated by endovascular treatment, complete aneurysm obliteration was achieved in 50, 65, 50, and 78%, respectively, and the combined transient and permanent morbidity rates due to cerebral embolic events were 20, 25, 20, and 13.9%, respectively. Overall, the transient morbidity rate after endovascular treatment was 14.3% and the permanent morbidity rate was 6.5%. Notably, permanent visual deficits caused by retinal embolism occurred after endovascular treatment in two patients with Group II aneurysms. Direct surgery was mainly performed in Groups Ia (20 lesions), Ib (five lesions), and II (eight lesions), with complete neck clip occlusion achieved in 80, 80, and 71.4%, respectively; the transient and permanent morbidity rates associated with aneurysms treated by surgery were 8.6 and 2.9%, respectively. CONCLUSIONS: Endovascular therapy for superiorly projecting paraclinoid aneurysms (Groups Ia and II) is associated with lower rates of complete obliteration than direct surgery, and with rates of cerebral embolic events comparable to those of endovascular treatment in the other groups. Furthermore, endovascular treatment for Group II aneurysms entails additional risks of retinal embolism. Therefore, direct surgery is recommended for the treatment of paraclinoid aneurysms projecting superiorly. For other groups, especially for Group III, endovascular treatment is the acceptable first line of therapy.     

Antegrade recanalization of a completely embolized vertebral artery after endovascular treatment of a ruptured intracranial dissecting aneurysm. Report of two cases

Occlusion of the parent artery is a traditional method of treatment of unclippable cerebral aneurysms. Surgical or endovascular occlusion of the parent artery proximal to the aneurysm has been recommended for the treatment of dissecting aneurysms located in the vertebrobasilar circulation. Nevertheless, occlusion of the parent artery may not result in permanent exclusion of the aneurysm from the systemic circulation because, occasionally, postoperative rebleeding occurs after proximal occlusion. Alternatively, endovascular occlusion of the affected site, including the aneurysmal dilation, and parent artery, is a safe and reliable treatment for dissecting aneurysms. The authors present two rare cases of ruptured vertebral artery (VA) dissecting aneurysms that were treated by endovascular occlusion of the affected site including the aneurysm and parent artery by using Guglielmi detachable coils. In both cases the VA recanalized in an antegrade fashion during the follow-up period. Based on these unique cases, the authors suggest that a careful angiographic follow up of dissecting aneurysms is required, even in patients successfully treated with endovascular occlusion of the affected artery and aneurysm.     

Complete neck clipping of internal carotid-posterior communicating artery aneurysms using bayonet-shaped aneurysm clips: technical note

Neck clipping for internal carotid-posterior communicating artery (IC-PC) aneurysms using standard straight, angled, or curved clip may result in remnant aneurysm neck. We describe complete neck clipping of IC-PC aneurysms using a bayonet-shaped clip. The bayonet-shaped clip is applied perpendicular to the long axis of the internal carotid artery (ICA), and the blades of the clip are inserted between the aneurysm neck and the ICA. Using the clip applicator, the clip is gradually rotated counterclockwise or clockwise for left or right ICA aneurysm, respectively, so that the distal and shank portions of the clip blade are located at the aneurysm neck in the posterior communicating artery (Pcom) and ICA, respectively. As a result, the distal flexure of the clip blade fits the junction of the ICA and Pcom. This technique was used in four patients with ruptured ICA aneurysms and five patients with unruptured ICA aneurysms. Postoperative cerebral angiography demonstrated no residual aneurysm neck and preservation of the Pcom in all patients. This technique is useful for cases of IC-PC aneurysm involving the origin of the Pcom.