Aneurysms of the intracavernous carotid artery: a multidisciplinary approach to treatment

Microsurgical Treatment of a Giant Intracavernous Carotid Artery Aneurysm in a Pediatric Patient: Case Report and Literature Review

Intracranial aneurysms in children account for 4%-5% of all cases, with 20% being considered giant (>25 mm). The main sites of occurrence are the internal carotid artery (ICA) and the middle cerebral artery (MCA). Rupture and secondary subarachnoid hemorrhage occur in approximately 55%-72.5% of cases, with a 10%-23% mortality rate. We report the case of a previously healthy nine-year-old girl who developed sudden, severe right retroocular pain and a holocranial headache as a mode of onset. Besides, the patient presented with double vision, and her relatives sought medical attention. Paresis of the right III, IV, and VI cranial nerves was found at physical examination. An MRI and digital subtraction angiography showed the presence of a giant aneurysm in the cavernous portion of the ICA with a mass effect. The patient was treated surgically through a high-flow bypass using a radial artery graft and trapping of the aneurysm. She had an uneventful postoperative course and was discharged three days after the operation to continue follow-up at the outpatient clinic. The therapeutic options were: a) an endovascular approach using flow diverters or stenting and coiling; or b) surgical treatment with proximal closure of the ICA if the patient had good collateral circulation or trapping the aneurysm combined with a high-flow bypass if the collateral circulation was not good or absent. After discussion, we decided on the surgical option. Even when the surgery was successful in this case, there is no consensus about the best way to treat it; the selection should be based on the center´s experience when confronting this rare entity.

Cefaléia e disfunção de nervos cranianos secundários a aneurisma de artéria carótida: relato de dois casos e revisão da literatura

O seio cavernoso é um plexo venoso localizado na base do crânio. Várias patologias, como processos inflamatórios, aneurismáticos ou metastáticos, podem afetar esse plexo. A síndrome do seio cavernoso ocorre quando os nervos estão envolvidos nessa região (nervos cranianos III, IV, VI e divisões do V). Essas relações anatômicas explicam que a diplopia e a dor são os sintomas iniciais mais comuns nesses pacientes. Os aneurismas carotídeos cavernosos (CCAs) representam 2% a 9% dos aneurismas. Relatamos dois pacientes que apresentaram síndrome do seio cavernoso decorrente de aneurismas da artéria carótida. O reconhecimento da etiologia desse quadro clínico diferenciado é fundamental para evitar complicações e direcionar a melhor conduta para cada paciente.

Opening of unusual vascular collaterals leads to early recanalization of a giant intracavernous carotid artery aneurysm following common carotid artery occlusion: A Case report and literature review

Background:

Parent artery occlusion (PAO) with or without bypass surgery is a feasible treatment for large intracavernous carotid artery (ICCA) aneurysms. The ideal occlusion site (internal or common carotid artery [CCA]) and ischemic complications after PAO have received special attention since the description of the technique. Unfrequently, some patients can also develop unusual external carotid artery-internal carotid artery collateral pathways distal to the ligation site that can explain the failure to aneurysm size reduction.

Case Description:

We describe a rare case of delayed refilling of a large ICCA aneurysm partially thrombosed which early recanalized after surgical ligation of the cervical CCA through an unusual collateral pathway.

Conclusion:

Based on our experience, we recommend periodic long-term follow-up neuroimaging, especially in those cases where potential collateral branches have not been clearly identified in the preoperative studies.

Cavernous Carotid Aneurysms: To Do or Not To Do?

Cavernous carotid aneurysms (CCA) pose considerable dilemmas in management. It is still unclear as to whether an asymptomatic CCA should be subjected to treatment. Similarly, the ideal management strategy for a symptomatic aneurysm is controversial. We present the case of a 60-year-old female with a giant CCA and discuss the management issues.

Post-traumatic Cavernous Carotid Pseudoaneurysm with Delayed Epistaxis

Cavernous carotid aneurysms (CCAs) pose considerable dilemmas in management. Delayed post-traumatic epistaxis is a rare presentation of CCA. Clinically, the symptomatic triad of unilateral blindness, orbital fractures, and massive epistaxis is pathognomonic for internal carotid artery (ICA) pseudoaneurysm. The epistaxis is usually profound, intermittent, and life-threatening in nature. As most of these cases are initially seen by a physician, a high index of suspicion is essential during its early identification. Traumatic aneurysms are pseudoaneurysms with a fibrous wall that rupture and cause massive epistaxis resulting from disruption through the sphenoid sinus wall. We report a young adult who presented with the triad and severe anemia four months following head injury. He was treated with ligation of the carotid artery and a high-flow extracranial-intracranial (EC-IC) bypass. In the era of endovascular coiling and flow diverters, EC-IC bypass still has a role in the treatment of complex giant aneurysms with comparable results.

Anterior Optic Pathway Compression Due to Internal Carotid Artery Aneurysms: Neurosurgical Management and Outcomes

Background and Purpose

Compression of the anterior optic pathway results in visual deficits that can lead to the detection of unruptured aneurysms in the internal carotid artery (ICA). The general types of treatment modalities for aneurysms and visual deficits include surgery and endosaccular coiling. This study retrospectively analyzed and compared the resolution of visual deficits following surgery or endosaccular coiling.

Methods

We reviewed data on 33 patients with unruptured ICA aneurysms who presented with visual field deficits caused by mass effects over the anterior optic pathway. Statistical analyses were performed to identify the variables associated with the recovery of visual symptoms.

Results

Eighteen patients underwent aneurysm clipping, 2 underwent bypass surgery with endovascular trapping, and 2 underwent endovascular trapping without bypass surgery (group A). Ten patients received endosaccular coiling (group B). The visual outcomes included the following: in group A, 17 patients (73.9%) demonstrated improvement and 6 patients (26.1%) demonstrated no changes or worse outcomes; in group B, 2 patients (20.0%) demonstrated improvement and 8 patients (80.0%) demonstrated no changes or worse outcomes. Group A was associated with a higher rate of favorable outcome than group B (P = 0.007). According to the multivariate analysis, treatment without endosaccular coiling (group A) was the only variable significantly associated with improvement of visual outcome (P = 0.005; OR = 28.523; 95% CI = 2.683-303.171).

Conclusions

Treatment modality was the only predictor of improvement in visual deficits. Treatment without endosaccular coiling resulted in visual improvement significantly more often in comparison with endosaccular coiling.

Combination treatment for rapid growth of a saccular aneurysm on the internal carotid artery dorsal wall: case report

Aneurysms arising from non-branching sites of the supraclinoid internal carotid artery (ICA) are considered rare, accounting for only 0.9-6.5% of all ICA aneurysms. They are thin-walled, broad-based, can easily rupture during surgery, and are referred to as dorsal, superior, anterior, or ventral wall ICA aneurysms, as well as blister-like aneurysms. Various treatment modalities are available for blister-like aneurysms, but with varying success. Here, we report on two cases of saccular shaped dorsal wall aneurysms. Both patients were transferred to the emergency department with subarachnoid hemorrhage because of an aneurysmal rupture. Computed tomography angiography and transfemoral cerebral angiography (TFCA) showed a dorsal wall aneurysm in the distal ICA. We performed clipping on the wrapping material (Lyodura®, temporal fascia). Follow-up TFCA showed rapid configuration changes of the right distal ICA. Coil embolization was also performed as a booster treatment to prevent aneurysm regrowth. Both patients were discharged without neurologic deficit. No evidence of aneurysm regrowth was observed on follow-up TFCA at two years. Dorsal wall ICA aneurysms can change in size over a short period; therefore, follow-up angiography should be performed within the short-term. In cases of regrowth, coil embolization should be considered as a booster treatment.

A case of bilateral giant internal carotid artery aneurysms at the cavernous portion managed by 2-stage extracranial-intracranial bypass with parent artery occlusion: consideration for bypass selection and timing of surgeries

Bilateral giant internal carotid artery (ICA) aneurysms at the cavernous portion with bilateral cranial nerve symptoms are extremely rare. Extracranial-intracranial (EC-IC) bypass with parent artery occlusion (PAO) is one of the preferred procedures for giant ICA aneurysm at the cavernous portion with cranial nerve palsy; however, optimal bypass selection and the timing of surgery are controversial, particularly in bilateral cases. A 28-year-old woman developed left third nerve palsy with giant ICA aneurysms at the bilateral cavernous portion. Because only the left aneurysm was symptomatic, she initially underwent left EC-IC bypass using a saphenous vein graft with PAO without complications, which relieved her symptoms. However, she developed right third/fifth nerve palsy 10 months later, at which time magnetic resonance (MR) imaging and MR angiography revealed an enlarged right ICA aneurysm and shrunken left ICA aneurysm. Balloon test occlusion of the right ICA identified sufficient ischemic tolerance; therefore, she underwent right superficial temporal artery-middle cerebral artery bypass with PAO. Both bypasses were confirmed by MR angiography to be patent after surgery. Cranial nerve palsy gradually improved postoperatively, and single-photon emission computed tomography confirmed static cerebral hemodynamics. In conclusion, high-flow EC-IC bypass with PAO is recommended in the first stage of surgery on a unilaterally symptomatic side to minimize postoperative hemodynamic stress to the contralateral aneurysm. Once the contralateral side becomes symptomatic, second stage EC-IC bypass with PAO, either low-flow or high-flow bypass, is recommended based on the results of balloon test occlusion.

Clinical and angiographic outcome of endovascular and conservative treatment for giant cavernous carotid artery aneurysms

This study evaluated the outcome of endovascular and conservative treatment for giant cavernous carotid artery aneurysms (CCAAs). We retrospectively reviewed a series of 35 consecutive giant CCAAs treated with endovascular and conservative treatment. All patients were evaluated by balloon occlusion test (BOT) before treatment. Patients who could tolerate BOT were treated by parent artery occlusion (PAO), those who could not tolerate BOT were treated by stent/coil or conservative methods. Eight patients were treated conservatively, symptoms were worsened in four patients (50%), unchanged in three, and improved in one at 33.6±19.9 months (6~65 months) follow-up. In 27 aneurysms treated with endovascular methods, 17 aneurysms were treated by PAO, eight aneurysms were treated with stent-assisted coil embolization, and two aneurysms were embolized with coils. The initial post-procedure angiogram revealed complete occlusion, neck remnant, and incomplete occlusion in 81.5 %, 11.1 %, and 7.4 %, respectively. Procedure-related mortality and morbidity were 0 and 7.4 %, respectively. At 33.1±17.4 months (4~71 months) follow-up, a good clinical outcome (mRS 0-1) was observed in 25 (92.6%) patients, symptoms were resolved or improved in 20 (74.1%). Statistical analysis showed that risk factors for poor clinical outcome included age of 60 years and older (P=0.006), and conservative treatments (P=0.038). Risk factors for poor clinical outcome of giant CCAAs included conservative treatment and age older than 60 years. A symptomatic giant cavernous carotid aneurysm should be treated. The outcome of endovascular treatment of giant CCAAs is promising.

Revascularization for complex cerebral aneurysms

BACKGROUND AND PURPOSE

Complex cerebral aneurysms may require indirect treatment with revascularization. This manuscript describes various surgical revascularization techniques together with clinical outcomes.

METHODS

Thirty-two consecutive patients with complex cerebral aneurysm were managed from November 2005 to October 2008. Techniques used for revascularization were high-flow bypass, low-flow bypass, branch artery reimplantion, and primary reanastomosis. Physiologic and anatomic monitoring technologies, including electroencephalography, somatosensory evoked potential monitoring, microvascular doppler ultrasonography, and/or indocyanine green videoangiography were used intraoperatively to assess both brain physiology and vascular anatomy. Patient outcome was determined using the Glasgow Outcome Scale at discharge and at a mean of 12 months post operation (range 6-25 months).

RESULTS

Two cervical carotid aneurysms (6%) were resected followed by primary reanastomosis, 21 aneurysms (66%) were trapped following saphenous vein high-flow bypasses, five (16%) were clipped after superficial temporal or occipital artery low-flow bypasses, and four (12%) middle cerebral branch arteries were reimplanted. Of the 32 patients at discharge, 29 (91%) had a Glasgow Outcome Scale of four or five, two (6%) had severe disability, and one (3%) died.

CONCLUSION

Cerebral revascularization remains an effective and reliable procedure for treatment of complex cerebral aneurysms. Low morbidity and mortality rates reflect the maturity of patient selection and surgical technique in the management of these lesions.

Cerebral perfusion long term after therapeutic occlusion of the internal carotid artery in patients who tolerated angiographic balloon test occlusion

BACKGROUND AND PURPOSE

Therapeutic carotid occlusion is an established technique for treatment of large and giant aneurysms of the ICA, in patients with synchronous venous filling on angiography during BTO. Concern remains that hemodynamic alterations after permanent occlusion will predispose the patient to new ischemic injury in the ipsilateral hemisphere. The purpose of this study was to assess whether BTO with synchronous venous filling is associated with normal CBF long term after carotid sacrifice.

MATERIALS AND METHODS

Eleven patients were included (all women; mean age, 50.5 years; mean follow-up, 38.5 months). ASL with single and multiple TIs was used to assess CBF and its temporal characteristics. Selective ASL was used to assess actual territorial contribution of the ICA and BA. Collateral flow via the AcomA or PcomA or both was determined by time-resolved 3D PCMR. Paired t tests were used to compare CBF and timing parameters between hemispheres.

RESULTS

Absolute CBF values were within the normal range. There was no significant CBF difference between hemispheres ipsilateral and contralateral to carotid sacrifice (49.4 ± 11.2 versus 50.1 ± 10.1 mL/100 g/min). Arterial arrival time and trailing edge time were significantly prolonged on the occlusion side (816 ± 119 ms versus 741 ± 103 ms, P = .001; and 1765 ± 179 ms versus 1646 ± 190 ms, P < .001). Two patients had collateral flow through the AcomA only and were found to have increased timing parameters compared with 9 patients with mixed collateral flow through both the AcomA and PcomA.

CONCLUSIONS

In this small study, patients with synchronous venous filling during BTO had normal CBF long term after therapeutic ICA occlusion.

Bilateral giant cavernous carotid artery aneurysms in a child with juvenile Paget's disease

BACKGROUND

Juvenile Paget disease (JPD) is a rare genetic bone disorder, also affecting the immune and vascular systems. We describe the first ever case of JPD associated with bilateral giant cavernous carotid artery aneurysms in a child.

CASE DESCRIPTION

A child with known JPD presented with left abducens nerve palsy and a computed tomographic angiogram revealed bilateral giant cavernous carotid artery aneurysms. He underwent a left-sided superficial temporal artery to middle cerebral artery bypass and endovascular carotid artery occlusion, followed by an identical procedure on the right side 3 months later and made an event-free recovery without any new neurological deficits.

CONCLUSIONS

This previously unreported association poses the question of determining the optimal management strategy for such cases. The pathophysiology and clinical features of JPD are discussed, with special emphasis on the management of giant cavernous carotid aneurysms in this subgroup of individuals.

Clinical and angiographic outcome after endovascular management of giant intracranial aneurysms

OBJECTIVE

Giant (>or=25 mm) intracranial aneurysms (IA) have an extremely poor natural history and continue to confound modern techniques for management. Currently, there is a dearth of large series examining endovascular treatment of giant IAs only.

METHODS

We reviewed long-term clinical and radiological outcome from a series of 39 consecutive giant IAs treated with endovascular repair in 38 patients at 2 tertiary referral centers. Data were evaluated in 3 ways: on a per-treatment session basis for each aneurysm, at 30 days after each patient's final treatment, and at the last known follow-up examination.

RESULTS

Ten (26%) aneurysms were ruptured. At the last angiographic follow-up examination (21.5 +/- 22.9 months), 95% or higher and 100% occlusion rates were documented in 64 and 36% of aneurysms, respectively, with parent vessel preservation maintained in 74%. Stents were required in 25 aneurysms. Twenty percent of treatment sessions resulted in permanent morbidity, and death within 30 days occurred after 8% of treatment sessions. On average, 1.9 +/- 1.1 sessions were required to treat each aneurysm, with a resulting cumulative per-patient mortality of 16% and morbidity of 32%. At the last known clinical follow-up examination (mean, 24.8 +/- 24.8 months), 24 (63%) patients had Glasgow Outcome Scale scores of 4 or 5 ("good" or "excellent"), 10 patients had worsened neurological function from baseline (26% morbidity), and 11 had died (29% mortality).

CONCLUSION

We present what is to our knowledge the largest series to date evaluating outcome after consecutive giant IAs treated with endovascular repair. Giant IAs carry a high risk for surgical or endovascular intervention. We hope critical and honest evaluation of treatment results will ensure continued improvement in patient care.

Surgical Treatment of Giant Intracranial Aneurysms: Current Viewpoint

Objective:

Despite new endovascular techniques and technological advances in microsurgery, the treatment of giant intracranial aneurysms is still a daunting neurosurgical task. Many of these aneurysms have a large, calcified neck, directly involve parent and collateral branches, and are partly thrombosed. In this retrospective review, we focused our analysis on the indications for high-flow, extracranial-intracranial (EC-IC) bypass surgery using a saphenous vein graft.

Methods:

A series of 130 patients were treated between 1990 and 2004; 31 patients were managed endovascularly, and 99 patients were treated microsurgically (surgical clipping in 58 patients and high-flow EC-IC bypass followed by aneurysm trapping in 41 patients). We examined the patients’ clinical records and pre- and postoperative case notes for cerebral angiographic examinations. Graft patency was verified with cerebral angiography, computed tomographic angiography, Doppler ultrasound, or graft palpation.

Results:

The high-flow EC-IC bypass was used for all surgically treated prepetrous aneurysms (3 patients), intracavernous aneurysms (1 patient), intracavernous aneurysms with subarachnoid extension (23 patients), as well as for some supraclinoid aneurysms (12 of the 32 patients). It was also used for 1 of the 9 aneurysms located in the carotid bifurcation and 2 of 5 vertebrobasilar circulation aneurysms. Of the 58 patients managed by surgical clipping, 4 (6.9%) died, and 51 (94.4%) improved. Of the 41 patients managed with high-flow EC-IC bypass, 4 (9.8%) died and 34 (91.9%) improved. Graft patency at the follow-up examination was 92.7%.

Conclusion:

The “gold standard” for the treatment of giant aneurysms remains surgical clipping. When direct surgical clipping or endovascular repair is contraindicated, the high-flow EC-IC bypass is a viable surgical option.

Rapid revascularization after therapeutic parent artery occlusion for a large intracavernous carotid artery aneurysm

A 21-year-old woman presented with an unruptured large intracavernous aneurysm, which was spontaneously revascularized via unusual collateral pathways a short time after extracranial-intracranial bypass and surgical ligation of the proximal internal carotid artery. The patient had been treated for a large basilar trunk aneurysm with intraaneurysmal embolization using Guglielmi detachable coils, and an intracavernous carotid artery aneurysm treated conservatively. Two years later, the patient presented with right abducens nerve palsy, and was referred to our hospital. She had small nevi in the right forehead and eyelid. Cerebral angiography revealed enlargement of the intracavernous aneurysm. Superficial temporal artery-middle cerebral artery bypass followed by surgical carotid artery ligation were performed, and good patency of bypass and disappearance of the aneurysm were confirmed by intraoperative angiography. However, follow-up magnetic resonance angiography and cerebral angiography on the 20th postoperative day revealed revascularization of the internal carotid artery and the intracavernous carotid artery aneurysm via unusual collateral pathways. Subsequently, the recurrent aneurysm and the recanalized internal carotid artery were occluded by endovascular procedures. Histological examination of the nevus showed lack of properly organized vascular structures, and the diagnosis was angiodysplasia. The early development of unusual collateral pathway, and aneurysm formation at a young age might be related to the angiodysplasia. Revascularization is possible within a short time even in cases of intracavernous carotid artery aneurysm successfully treated with surgical ligation of the parent artery.

Endovascular treatment of blood blister-like aneurysms of the internal carotid artery

OBJECT

Because of its thin wall, an aneurysm arising from the posterior wall of the internal carotid artery (ICA), the so-called blood blister-like aneurysm (BBA), is difficult to manage surgically and is often associated with high morbidity and mortality rates. The authors treated these aneurysms endovascularly. In this paper, they present angiographic and clinical results obtained in patients with ICA BBAs treated endovascularly.

METHODS

In seven patients with ICA BBAs who presented with subarachnoid hemorrhage, a total number of 12 endovascular treatments were performed, including seven endosaccular coil embolizations (four conventional, two stent-assisted and one balloon-assisted procedure) in four patients and five endovascular ICA trapping procedures in five patients. Repeated endovascular treatments were undertaken in four patients. In two patients, the endovascular treatment was performed after failure of surgical treatment (one case of rebleeding after clip placement and one aneurysmal regrowth after wrapping). A balloon occlusion test (BOT) was performed in all patients prior to ICA trapping. All four patients treated by endosaccular coil embolization showed aneurysmal regrowth. Neither stents nor balloons helpfully prevented aneurysmal regrowth. Of these four patients, two experienced rebleeding. These two patients remained vegetative at the last follow-up examination. After the BOT, ICA trapping was performed with coils and balloons without complication in five patients; excellent outcomes were achieved in all cases but one in which the patient had been in poor neurological condition due to rebleeding after surgical clip therapy.

CONCLUSIONS

All ICA BBAs that were treated by endosaccular coil embolization exhibited regrowth of the aneurysm. Some of the lesions rebled. The majority of patients who underwent ICA trapping experienced excellent outcomes. Based on the authors' experiences, they suggest that ICA trapping including the lesion segment should be considered as a first option for definitive treatment if a BOT reveals satisfactory results. Regarding trapping methods, endovascular treatment may be preferred because of its convenience and safety.

[Giant aneurysm of the intracavernous internal carotid artery associated with autosomal dominant polycystic kidney disease: case report]

We report the case of a 60-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) that presented with headache and right complete ophthalmoplegia. The CT scan raised the possibility of a giant aneurysm of the right intracavernous internal carotid artery, confirmed by angiography. The patient underwent endovascular occlusion of parent vessel with detachable coils, then she presented interruption of headache and partial recovery of ptosis and ophthalmoplegia. We emphasize the relationship between ADPKD and intracranial aneurysms. We also discuss the natural history and compare the therapeutic options for the management of giant aneurysms of the cavernous portion of the carotid artery.

Surgical decompression and coil removal for the recovery of vision after coiling and proximal occlusion of a clinoidal segment aneurysm: technical case report

OBJECTIVE

We present the case of a patient with continued deterioration of vision after endovascular treatment of an unruptured clinoidal segment aneurysm. In conjunction with a review of the literature, the findings in this case highlight the need for further refinements in our understanding of pathophysiological changes induced by coiling of cerebral aneurysms, especially those in aneurysms producing signs and symptoms relating to mass effect.

CLINICAL PRESENTATION

The patient is a 45-year-old man who presented with progressive vision loss. Imaging studies revealed a large, clinoidal segment aneurysm. The patient continued to experience progressive vision loss despite treatment with endovascular coiling, proximal occlusion, and high-dose steroid medication.

INTERVENTION

The patient underwent a craniotomy for decompression of the optic nerve and for salvage of vision. Clipping of the distal vessel was performed, and the coil mass was removed. The patient experienced marked improvement of central vision after the surgical procedure.

CONCLUSION

Although endovascular treatment of aneurysms protects most patients from aneurysm rupture, this case illustrates the fact that coiling, followed by proximal occlusion, might fail to alleviate symptoms related to mass effect. Our experience in this case suggests that early surgical decompression may be indicated for patients presenting with progressive visual deterioration.

Revascularization and Parent Artery Occlusion for Giant Internal Carotid Artery Aneurysms in the Intracavernous Portion Using Intraoperative Monitoring of Cerebral Hemodynamics

OBJECTIVE:

Therapeutic parent artery occlusion with or without revascularization is a useful surgical technique for the management of a giant aneurysm located in the intracavernous portion of the internal carotid artery (ICA). The purpose of the present study was to determine whether intraoperative cortical blood flow (CoBF) monitoring during surgical parent artery occlusion could identify patients who required bypass with a saphenous vein graft (high flow bypass).

METHODS:

Eleven patients with a giant aneurysm located in the intracavernous portion of the ICA underwent superficial temporal artery-middle cerebral artery bypass. CoBF was monitored intraoperatively in all patients using a thermal diffusion flow probe. The lowest CoBF during test occlusion of the ICA under functioning superficial temporal artery-middle cerebral artery bypass was determined, and the ratio of the value to the CoBF immediately before test occlusion of the ICA was calculated in the frontal and temporal lobes. When the CoBF ratio in the frontal or temporal lobe was less than 0.9, high flow bypass grafting was elected.

RESULTS:

Of the eleven patients undergoing superficial temporal artery-middle cerebral artery bypass, five patients underwent concomitant high flow bypass grafting. Postoperative cerebral ischemic events did not occur in any patient over a follow-up period ranging from 3 to 60 months. Postoperative cerebral angiography showed resolution of the aneurysm and patency of the bypass in all patients.

CONCLUSION:

Intraoperative CoBF monitoring using a thermal diffusion flow probe during surgical parent artery occlusion for giant intracavernous carotid artery aneurysms can identify patients who require concomitant high flow bypass grafting.

Revascularization with saphenous vein bypasses for complex intracranial aneurysms

Most intracranial aneurysms can be managed with either microsurgical clipping or endovascular coiling. A subset of complex aneurysms with aberrant anatomy or fusiform/dolichoectatic morphology may require revascularization as part of a strategy that occludes the aneurysm or parent artery or both. Bypass techniques have been invented to revascularize nearly every intracranial artery. An aneurysm that will require a saphenous vein bypass is one that cannot be treated with conventional microsurgical clipping or endovascular coiling and also requires deliberate sacrifice of a major intracranial artery as part of the alternative treatment strategy. In the past 7 years the senior author (MTL) has performed a total of 110 bypasses, of which 46 were for aneurysms. Twenty-two of these patients received high-flow extracranial-to-intracranial bypasses using saphenous vein grafts, of which 16 had aneurysms that were giant in size. We review the indications for saphenous vein bypasses for complex intracranial aneurysms, surgical techniques, and clinical management strategies.

MRI location of the distal dural ring plane: anatomoradiological study and application to paraclinoid carotid artery aneurysms

The distal dural ring plane (DDRP) separates the intradural from the extradural paraclinoid internal carotid artery. The purpose of this study was to evaluate its position with MR imaging. The protocol used a T2-weighted sequence in two orthogonal planes: diaphragmatic (DIA-P) and carotid (CAR-P). The DDRP passes through four anatomoradiological reference points (RefP). We developed on a cadaveric model a correlation method supported by correlation lines and angles (CA) projecting the RefP toward the DDRP. RefP were correlated to the DDRP in 65-84% of cases in the DIA-P and 60-76% of cases in the CAR-P. CA were identified and correlated to the DDRP, respectively, in 87% and 60% of cases in the DIA-P, and 60% and 51% of cases in the CAR-P (failure often related to a lack of visibility of just one RefP). A higher tissular contrast in living subjects allowed the identification of CA in 90% and 80% of cases, respectively, in the DIA-P and the CAR-P. We propose that CA, when identified, should be considered as an approximation of the inferior radiological limit of the DDRP curve. In difficult angiographical cases, this MRI protocol could help to locate paraclinoid aneurysms on both sides of the cavernous sinus roof.

Microsurgical anatomy of cerebral revascularization. Part I: Anterior circulation

Object. Revascularization is an important component of treatment for complex aneurysms that require parent vessel occlusion, skull base tumors that involve major vessels, and certain ischemic diseases. In this study, the authors examined the microsurgical anatomy of cerebral revascularization in the anterior circulation by demonstrating various procedures for bypass surgery.

Methods. Twenty-five adult cadaveric specimens were studied, using 3 to 40 magnification, after the arteries and veins had been perfused with colored silicone. The microsurgical anatomy of cerebral revascularization in the anterior circulation was examined with the focus on the donor, recipient, and graft vessels. The techniques discussed in this paper include the superficial temporal artery (STA)—middle cerebral artery (MCA), middle meningeal artery (MMA)—MCA, and side-to-side anastomoses; short arterial and venous interposition grafting; and external carotid artery/internal carotid artery (ICA)—M2 and ICA—ICA bypasses. Bypass procedures for cerebral revascularization are divided into two categories depending on their flow volume: low-flow and high-flow bypasses. A low-flow bypass, such as the STA—MCA anastomosis, is used to cover a relatively small area, whereas a high-flow bypass, such as the ICA—ICA anastomosis, is used for larger areas. Cerebral revascularization techniques are also divided into two types depending on the graft materials: pedicled arterial grafts, such as STA and occipital artery grafts, and free venous or arterial grafts, which are usually saphenous vein and radial artery grafts. Pedicled arterial grafts are mainly used for low-flow bypasses, whereas venous or arterial grafts are used for high-flow bypasses.

Conclusions. It is important to understand the methods of bypass procedures and to consider indications in which cerebral revascularization is needed.

Stent-Graft Treatment of Extracranial Carotid and Vertebral Arterial Lesions

Five patients with pseudoaneurysms of the carotid artery (n = 4) and an arteriovenous fistula of the vertebral artery (n = 1) were treated with stent-grafts. Commercially made devices were used in all but one of the patients. In four of the five patients, the pathology was successfully excluded. One patient had a small type-I endoleak. There were no immediate procedure-related complications or neurologic sequalae. All experienced immediate resolution of symptoms. One patient was lost to follow-up after discharge and another died 2 weeks after intervention. The remaining patients remained asymptomatic with patent stent-grafts after follow-up periods of 14, 16, and 46 months, respectively.

Mycotic intracavernous carotid aneurysm

Intracavernous carotid mycotic aneurysms are rare and management is dictated by clinical presentation. This case involved a patient presenting with a symptomatic expanding proximal internal carotid artery aneurysm treated with antibiotics and balloon occlusion but with thromboembolic complications resulting in a fatal outcome. Points of discussion include difficulties faced in reaching a diagnosis, management options for mycotic aneurysms and the rationale in this case for choosing endovascular rather than surgical treatment. The use and limitations of trial balloon occlusion are discussed as well as complications of vessel occlusion, in particular thromboembolism. Also discussed is the importance of surveillance imaging and the impact of sepsis on overall management.

Management of intracranial complications of sinus surgery

Endoscopic sinus surgery has an impressive and continually im-proving safety record. Increasing surgical experience and improved techniques and equipment make this procedure fundamentally safe. Anatomic variations, extensive disease, and the tight confines that the sinuses occupy between the skull base and orbits, however, do allow the possibility of untoward events. Many of these complications are minor, but the potential for significant morbidity, including blindness, diplopia, cerebrospinal fluid fistula with or without meningitis, intracranial brain injury, and hemorrhage from internal carotid artery injury, is real. This article discusses the avoidance and management of these complications.

Reconstructive endovascular approach for a cavernous aneurysm in infancy

We report a unique case of endovascular arterial reconstruction using stent and coils in a symptomatic cavernous aneurysm presented in infancy. A 3-year-old infant presented with a partial cavernous sinus syndrome secondary to a bilobulate cavernous aneurysm with subarachnoid extension. Direct clipping represented a considerable challenge and trapping after bypass grafting was considered to risky. A combined endovascular approach using stent and coils was performed. A 4 x 18 mm balloon-expandable stent was then placed across the aneurysm orifice allowing the complete obliteration of the remnant with coils implanted through the stent mesh. Digital substraction angiography documented patency of the ICA lumen and complete obliteration of the aneurysm. A 24-months angiographic follow-up was performed confirming persistent aneurysm exclusion and patency of the parent vessel with no signs of in-stent de novo stenosis. Reconstructive endovascular technique using stent and coils allowed the treatment of a complex vascular condition. The cavernous lesion was excluded from the circulation while preserving normal flow through the parent vessel and its branches. Long-tern follow up is a major concern, specially in pediatric patients but the 24 months angiographic follow-up is encouraging.

Endovascular treatment of aneurysms in the cavernous sinus: a systematic review on balloon occlusion of the parent vessel and embolization with coils

BACKGROUND AND PURPOSE

Balloon occlusion of the parent vessel and endosaccular coiling are both frequently used for treatment of intracavernous aneurysms of the carotid artery. We performed a systematic review of studies reporting on these two treatment modalities to assess the rate of complications, rate of successful aneurysm occlusion, and clinical condition after treatment.

METHODS

We performed a MEDLINE search for studies published between January 1974 and May 1999 and hand-searched recent volumes of 21 journals. Two authors independently extracted data by means of a standardized data extraction form.

RESULTS

We found 35 studies reporting on 316 patients. Only 9 of the 35 studies reported on more than 5 patients; in only 9 studies (totaling 85 patients), well-defined outcome measures were used. Twenty-five studies (with 78% of all patients included in the review) reported on balloon occlusion. Complications during or in the first 24 hours after the balloon occlusion occurred in 4 of 247 patients (1.6%; 95% CI, 0.01% to 3.2%) and late ischemic complications in 5 of 148 patients (3.4%; 95% CI, 0.43% to 6.4%). Clinical follow-up was performed in 21 of 25 studies on treatment by means of balloon occlusion (148 [60%] of the 247 patients). None of the 68 patients treated by embolization with coils had a complication (0%; 95% CI, 0% to 4.3%). Of 157 aneurysms treated by balloon occlusion, 153 were completely thrombosed (97.5%; 95% CI, 95% to 100%). After coiling, 52 of 65 aneurysms (80%; 95% CI, 70% to 90%) were occluded by >90%.

CONCLUSIONS

Many studies included in this review had methodological weaknesses. The available data suggest that both balloon occlusion and endosaccular coiling are reasonably safe and result in occlusion of the aneurysm in the majority of patients. However, long-term outcomes have not yet been reported.

Spontaneous thrombosis of intracavernous internal carotid artery aneurysm and parent artery occlusion in patients with positive balloon test occlusion--two case reports

Two patients with giant intracavernous internal carotid artery (ICA) aneurysms were intolerant to balloon test occlusion of the ICA, and later developed spontaneous thrombosis of the aneurysm and the parent ICA without ischemic sequelae. Case 1: A 60-year-old female with a giant right intracavernous ICA aneurysm presented with right abducens nerve paresis. An unsuccessful extracranial-to-intracranial bypass graft operation was complicated by transient postoperative ophthalmoplegia. The patient did not tolerate balloon test occlusion of the right ICA after attempted bypass surgery, and was treated conservatively. The patient presented with acute onset of headache 3 years later. Case 2: A 50-year-old female with a giant right intracavernous ICA aneurysm presented with right abducens nerve paresis. The patient was managed conservatively after a positive balloon test occlusion of the right ICA. The patient suffered transient hypopituitarism and acute onset of headache 2 years later. Spontaneous thrombosis of the aneurysms and occlusion of the parent ICA were found in both patients. Neither had major hemispheric infarcts, but the first patient had asymptomatic infarcts, which were presumed to be thromboembolic in nature. Patients with intracavernous ICA aneurysms who have positive balloon test occlusions appear to develop tolerance to spontaneous and gradual occlusion of the ICA without significant sequelae. However, these patients have an increased risk of developing embolic infarctions. The role for anticoagulation and repeat hemodynamic tests remains unclear.

GDC Embolisation of Cavernous Internal Carotid Artery Aneurysms with Parent Artery Preservation

SUMMARY

We evaluated the clinical and angiographic results of endosaccular treatment with Guglielmi detachable coils (GDCs) in 19 cases of cavernous internal carotid artery (ICA) aneurysms. The size of the aneurysms ranged from 10 to 30 mm (mean 18.4 mm) and neck size ranged from 2 to 15 mm (mean 6.7 mm). Intraluminal thrombosis was found in ten cases. Main presenting symptoms were related to mass effect in 17 cases including cranial nerve palsy, headache and vomiting. On initial GDC embolisation, total occlusion was obtained in two cases, subtotal in eight, and incomplete in nine. In two cases with incomplete occlusion, parent arteries were occluded with balloons or GDCs during or just after the procedure because of underlying diseases. A higher rate of initial occlusion was obtained in smaller and non-thrombosed aneurysms. Symptoms resolved or improved in all cases except one after initial treatment. No complication occurred related to the procedure. Follow-up angiography was obtained in 15 cases among which ten cases (66.7%) showed luminal recanalisation. Symptoms recurred in one case with luminal recanalisation. Incidence of recanalisation was similar in both large and giant aneurysms but higher in the thrombosed than non-thrombosed group. Retreatment was done in five cases with success. In conclusion, although embolisation of cavernous ICA aneurysms with GDCs was safe and effective in relieving symptoms, the incidences of initial incomplete occlusion and follow-up recanalisation were high. Therefore, we think judicious selection of the cases is necessary for endosaccular GDC embolisation in cavernous ICA aneurysms.

Surgical repair of clinoidal segment carotid artery aneurysms unsuitable for endovascular treatment

OBJECTIVE

Clinoidal segment carotid artery aneurysms are surgically challenging lesions. The aneurysm neck originates proximal to the distal dural ring, and the aneurysms typically are larger. Therefore, endovascular techniques are often considered to be the primary treatment option. Treatment techniques and results for 40 clinoidal segment carotid artery aneurysms that were considered unsuitable for contemporary endovascular intervention are analyzed in this report.

METHODS

Forty aneurysms in 33 female and 3 male patients were treated surgically. Fifteen patients had bilateral aneurysms; of these patients, four underwent bilateral craniotomies. Twenty-seven aneurysms were 10 to 14 mm in size, eight were 15 to 24 mm, and five were more than 25 mm. The most common presentation was visual loss, which occurred in 13 patients. Seven patients presented with subarachnoid hemorrhage.

RESULTS

Thirty-seven aneurysms were directly repaired with clipping, two were trapped with bypass, and one was trapped without bypass. The complication rate was 10%, with one major stroke, two minor strokes, and one successfully treated brain abscess.

CONCLUSION

Surgical treatment of clinoidal segment carotid artery aneurysms can produce acceptable outcomes. Specific preoperative and intraoperative techniques facilitate improved surgical results for aneurysms that are not treatable with contemporary endovascular techniques.

Contralateral approach to junctional C2-C3 and proximal C4 aneurysms of the internal carotid artery: microsurgical anatomic study

OBJECTIVE

To evaluate a contralateral approach to aneurysms located in the internal carotid artery cave and proximal C4 segments.

METHODS

In six adult cadaveric head sides, proposed aneurysms in the carotid cave or proximal C4 segments were approached via contralateral craniotomies. We summarize the approach in the following steps: 1) frontotemporal orbital craniotomy, 2) drilling of the lateral sphenoid wing and opening of the dura along the frontotemporal base, 3) drilling of the planum sphenoidale and the tuberculum sellae more extensively toward the aneurysm side and opening of the sphenoid sinus, 4) drilling of the medial part of the anterior clinoid process on the side of the aneurysm and removal of the superior, medial, and inferior walls of the optic canal, 5) opening of the optic sleeve, and 6) opening of the space between the medial wall of the internal carotid artery C2-C3 segments and the lateral edge of the pituitary gland.

RESULTS

The contralateral approach to expose the opposite internal carotid artery cave and proximal C4 segments provided excellent views of the region, without mobilization or retraction of either the optic nerve or the carotid artery.

CONCLUSION

We recommend that this approach be used only for selected aneurysms, which are small and directed medially, anteriorly, or inferiorly, in the defined locations.

Long-term follow-up study of patients with cavernous sinus aneurysm treated by proximal occlusion

Proximal occlusion of the internal carotid artery (ICA) is still the treatment of choice for a large cavernous sinus aneurysm. Endovascular occlusion or trapping of the ICA with or without an extracranial-intracranial bypass is sometimes performed. We analyzed the results of the long-term follow up of 11 patients with a giant or large cavernous sinus aneurysm treated by only proximal occlusion between 1975 and 1989. Proximal occlusion of the carotid artery was performed by Selverstone clamping. The follow-up period ranged from 6 to 21 years (mean 13.9 years). Eight of the 11 patients showed improvement of cranial nerves paresis or headache, and four became asymptomatic. None of the original aneurysms ruptured. The final outcomes were nine good recovery, one moderately disabled, and one severely disabled by the Glasgow Outcome Scale. The causes of morbidity were early ischemia and subarachnoid hemorrhage from a newly formed aneurysm. Late complications included ischemia in two patients, and new formation and enlargement of aneurysms at a site other than the original aneurysm in two patients, 13 and 17 years later. Therapeutic carotid artery occlusion requires strict test ICA occlusion. In addition, long-term follow up by periodical cerebral angiography using magnetic resonance, computed tomography, or digital subtraction angiography is necessary, and postoperative medical treatment is important to reduce the risk of late complications.

Spontaneous occlusion of supraclinoid aneurysms after the creation of extra-intracranial bypasses using long grafts: report of two cases

OBJECTIVE

We describe two cases of giant supraclinoid aneurysms, treated by means of saphenous vein grafting between the external carotid artery and the middle cerebral artery, which unexpectedly spontaneously occluded.

CLINICAL PRESENTATION

Two patients presented with subarachnoid hemorrhage and headache, respectively. In the first case, angiography showed an aneurysm of the right internal carotid artery (ICA), which had been treated by clipping. Repeat angiography showed a giant aneurysm of the right ICA, the formation of which was probably caused by sliding of the clip that had been applied during the previous operation. The patient was operated on again, but it was impossible to exclude the aneurysm because no clear neck could be identified. In the second case, magnetic resonance imaging and cerebral angiography showed a large, partially thrombosed aneurysm of the supraclinoid segment of the left ICA.

TECHNIQUE

In view of the patients' ages and the statuses of compensatory circulation, each patient underwent cerebral revascularization with a long saphenous vein graft placed between one branch of the middle cerebral artery and the external carotid artery, in anticipation of subsequent endovascular treatment of the aneurysm and/or closure of the ICA in the neck. Postoperative angiography demonstrated spontaneous occlusion of the aneurysms.

CONCLUSION

Thrombosis of an aneurysm may occur spontaneously or after explorative surgery. However, it should be remembered that spontaneous occlusion of an aneurysm may be induced or favored by hemodynamic vascular alterations that take place inside the aneurysm after a high-flow extra-intracranial bypass has been created.

Complex intracranial aneurysms: combined operative and endovascular approaches

OBJECTIVE

Endovascular management of complex intracranial aneurysms is increasingly being considered as an alternative to standard surgical clipping. However, little attention has been paid to the complementary nature of surgery and endovascular therapy.

METHODS

Between September 1992 and May 1997, 12 patients with complex intracranial aneurysms were treated with combined operative and endovascular methods. Seven patients demonstrated subarachnoid hemorrhage (two of Grade II, two of Grade III, and three of Grade IV). Five patients demonstrated unruptured aneurysms, i.e., three giant aneurysms (one vertebrobasilar junction aneurysm, one middle cerebral artery bifurcation aneurysm, and one internal carotid artery-ophthalmic artery aneurysm), one large internal carotid artery-ophthalmic artery aneurysm, and one middle cerebral artery serpentine aneurysm. Management strategies involved either surgery followed by endovascular therapy (S-E; n = 5) or endovascular therapy followed by surgery (E-S; n = 7). S-E paradigms included aneurysm exploration followed by endovascular treatment (S-E1; n = 3), partial aneurysm clipping followed by endovascular aneurysm packing (S-E2; n = 1), and extracranial-to-intracranial bypass followed by endovascular parent vessel occlusion (S-E3; n = 1). E-S paradigms included superselective angiography followed by surgical clipping (E-S1; n = 2), Guglielmi detachable coil partial dome packing followed by delayed surgical clipping (E-S2; n = 2), proximal temporary vessel balloon occlusion followed by aneurysm clipping (E-S3; n = 2), and proximal permanent vessel occlusion followed by surgical aneurysm decompression for mass effect treatment (E-S4; n = 1).

RESULTS

Eleven aneurysms (92%) were completely eliminated. The remaining aneurysm was 90% obliterated and remained quiescent at the 34-month follow-up examination, despite presenting with subarachnoid hemorrhage. No patient experienced repeat bleeding (follow-up period, 23+/-28 mo). There were no deaths. One patient achieved a fair outcome (Glasgow Outcome Scale score of III); all other patients experienced excellent outcomes (Glasgow Outcome Scale score of I). In all cases, the aneurysm management paradigm chosen had a positive effect on definitive therapy.

CONCLUSION

Several factors can contribute to the complexity of intracranial aneurysms. Management strategies that combine operative and endovascular techniques in a complementary way, for the best possible outcomes for these patients, can be designed accordingly.

Traumatic intracranial carotid tree aneurysms

OBJECTIVE

This study was designed to elucidate the requirements for angiographic evaluation in blunt head injuries, the timing of angiography, and the selection of appropriate therapeutic approaches.

METHODS

Twelve cases of traumatic aneurysms (TAs) in the intracranial carotid tree were analyzed in this study. Neurological examination results, computed tomographic scans, pre- and postembolization cerebral angiograms, and follow-up data were included.

RESULTS

In 11 of 12 cases, TAs were of cranial base origin; in 1 case, the aneurysm was located in the distal anterior cerebral artery. In seven of the cases with cranial base lesions, aneurysms were located in the intracavernous segment of the internal carotid artery; all of the computed tomographic scans for these cases demonstrated sphenoid sinus wall fractures and hematoma in the sphenoid sinus. In two cases, although the initial angiograms revealed no lesions, a second study performed 2 weeks later demonstrated the presence of aneurysms. Nine of the aneurysms were treated with endovascular techniques, two were managed conservatively, and the remaining one patient died with massive epistaxis while awaiting surgical treatment. No morbidity or additional permanent neurological deficits occurred in the endovascularly treated patient group.

CONCLUSION

Patients with head trauma who present with sphenoid sinus fractures and massive epistaxis should be evaluated for the development of TAs as soon as possible. If the patients exhibit fractures without epistaxis, angiography should be deferred for 2 to 3 weeks; if the first angiographic evaluation reveals normal findings, repeated epistaxis should prompt a second angiographic evaluation. Current treatment of TAs involves occlusion of the main artery through the use of endovascular techniques. Cases involving internal carotid artery TAs of cranial base origin and patients who do not tolerate test occlusion require extracranial-to-intracranial bypass surgery.

A protocol for management of a catastrophic complication of functional endoscopic sinus surgery: internal carotid artery injury

Injury to the cavernous portion of the internal carotid artery is a well recognized and dreaded complication of functional endoscopic sinus surgery. Little information, however, has been presented in the Otolaryngology literature regarding the etiology, prevention, or treatment of this complication. The purpose of this study is to present a case report of a cavernous carotid artery injury during functional endoscopic sinus surgery. Relevant anatomy, preventive measures, and treatment approaches are discussed for this difficult problem.

Treatment of inoperable carotid aneurysms with endovascular carotid occlusion after extracranial-intracranial bypass surgery

OBJECTIVE

Hunterian ligation of the internal carotid artery (ICA) is an accepted treatment for inoperable carotid aneurysms. Preliminary extracranial-intracranial (EC-IC) bypass surgery is required in some patients. The reported incidence of thromboembolic and ischemic complications remains significant for these patients, despite a variety of advocated management strategies. We present our treatment paradigm.

METHODS

Between April 1992 and March 1997, nine patients with inoperable ICA aneurysms were treated using EC-IC bypass surgery and then permanent endovascular ICA occlusion. All of the patients except one had been selected for bypass surgery on the basis of failing results of the ICA test occlusion with hypotensive challenge. ICA occlusion was performed by endovascular means and was delayed after bypass surgery was performed by a mean of 6 days (range, 2-20 d). All patients were managed in the intensive care unit after ICA occlusion.

RESULTS

Clinical improvement was noted in all patients (mean follow-up, 21 mo; range, 3-42 mo). There were no major complications. Aneurysmal thrombosis was confirmed in all patients. Although ICA occlusion was delayed after bypass surgery, only one bypass was noted to be occluded. The occluded bypass occurred in a patient who subsequently underwent successful ICA occlusion. This patient was thought to have been improperly selected for bypass surgery.

CONCLUSION

Certain carotid aneurysms can be effectively managed with hunterian ICA ligation. After preliminary identification of patients with borderline cerebrovascular reserve as candidates for EC-IC bypass surgery, close attention to the following points may help enhance clinical outcome: 1) excellence in surgical technique for EC-IC bypass surgery, 2) occlusion of the parent vessel as close to the aneurysm neck as possible by endovascular means, and 3) judicious postoperative combination of anticoagulation, fluid, and pressure management.

Transient enlargement of an intracranial aneurysm during pregnancy: case report

BACKGROUND

The association of intracranial aneurysm and pregnancy is uncommon. Hemodynamic stress plays an important role in the growth of aneurysms.

METHODS

The authors report the case of an enlarging cavernous carotid aneurysm in a pregnant 15-year-old young woman.

RESULTS

The aneurysm was initially diagnosed prior to the patient's pregnancy by both cross-sectional imaging and cerebral angiography. Further imaging evaluation was required during pregnancy, which demonstrated significant enlargement of the aneurysm. Following delivery, the lesion decreased in size.

CONCLUSIONS

We review potential factors associated with pregnancy that may increase hemodynamic stress and influence aneurysm growth. Additionally, the management of pregnancy-related intracranial aneurysms is discussed.

Preoperative risk assessment for carotid occlusion by transcranial Doppler ultrasound

OBJECTIVES

An endovascular carotid balloon occlusion test with continuous intracranial monitoring by transcranial Doppler sonography was performed in 55 patients for prediction of tolerance of a required permanent occlusion of the carotid artery.

METHODS

Blood flow velocities of the ipsilateral middle cerebral artery during occlusion were recorded and compared with clinical tolerance during an occlusion test as well as with postoperative outcome after an eventual permanent occlusion. To stress the capacity of the cerebral circulation to tolerate the occlusion acetazolamide was injected before occlusion in all patients.

RESULTS

The onset of neurological symptoms during temporary occlusion was dependent on the percentage fall of mean blood flow velocity relative to baseline rather than on absolute flow velocities during the time of occlusion. Patients with a fall of mean flow velocity of less than 30% tolerated temporary and permanent occlusion, with the exception of two patients who developed an infarction due to thromboembolism after iatrogenic sacrifice of the carotid artery. Patients with a major decrease developed neurological symptoms during occlusion in 55% and, in cases of carotid ligation, a haemodynamic infarction occurred.

CONCLUSION

The results show that transcranial Doppler monitoring as a part of an endovascular balloon occlusion test may be a reliable technique for preoperative risk assessment for permanent occlusion of the carotid artery.

False aneurysms of the intracavernous carotid artery--report of 7 cases

We present 7 cases of false intracavernous carotid artery aneurysms. Four occurred after trauma and three were caused iatrogenically. Two of the latter occurred in patients with pituitary adenomas, one after transsphenoidal microsurgery and the other after yttrium [YI90] seed implantation into the sella. The third iatrogenic aneurysm was seen shortly after transcavernous tumour surgery. In five of our seven patients massive, delayed, life-threatening epistaxis was the leading symptom. All traumatic cases were associated with immediate unilateral blindness or blurred vision and with skull base fractures. One of these had a concomitant carotid cavernous fistula. Treatment of choice of our 5 recent cases was permanent balloon occlusion of the intracavernous carotid artery at the level of the lesion. Collateral circulation was evaluated prior to definitive carotid occlusion using a balloon test occlusion. During the balloon test adequate collateral circulation was defined as symmetric angiographic filling of both hemispheres. Awake patients were neurologically examined continuously. In unconscious patients transcranial Doppler sonography, electroencephalographic and somatosensory evoked potential monitoring was used in addition. Intra-operative heparin administration was not reversed with protamin. A postoperative continuous heparin infusion was not found necessary. In our two early cases this technique was not available: In the first case we accomplished aneurysm occlusion by a surgically introduced Fogarty balloon catheter. Our second patient needed surgical trapping of the involved carotid after early unsuccessful attempts of selective aneurysm occlusion. After treatment no further epistaxis occurred. Follow-up angiography showed persistent aneurysm occlusion. The results were excellent in 5 cases and good in 1 case. One patient with bilateral lesions suffered a stroke after occlusion of the second, remaining carotid artery, despite functioning bilateral extra-intracranial bypasses. Four years later there is a mild dysphasia still present in this patient. The mean follow-up time was 75.6 months.