Revascularization and aneurysm surgery: current techniques, indications, and outcome

Augmentation of endothelial function by endothelin antagonism in human saphenous vein conduits

OBJECT

Cerebral revascularization with saphenous vein (SV) conduits is used in the management of hard-to-treat lesions that require deliberate arterial occlusion and in selected patients with occlusive vascular disease. Endothelial dysfunction is thought to contribute to acute perioperative vasospasm and chronic graft atherosclerosis. In the present study the authors examined the contribution of the potent vasoconstrictor endothelin-1 (ET-1) to endothelial dysfunction in human SVs.

METHODS

The effects of an ET(A/B) receptor antagonist (bosentan), an ET(A) receptor antagonist (BQ-123), and an ET(B) receptor antagonist (BQ-788) on in vitro endothelium-dependent and -independent responses were studied in human SVs. Vascular segments were obtained in 34 patients who had undergone revascularization procedures, and isometric dose-response curves (DRCs) were constructed using the isolated tissue bath procedure as follows: 1) cumulative DRCs to norepinephrine; and 2) DRCs to acetylcholine (ACh) and sodium nitroprusside in the absence and presence of bosentan, BQ-123, or BQ-788. Maximal vasodilatory responses and sensitivity were compared between groups. In the presence of bosentan (Experiment 1) and BQ-123 or BQ-788 (Experiment 2), ACh responses were significantly augmented (percent maximum relaxation values: 7+/-2 [control] compared with 17+/-3 [bosentan], p < 0.002 [Experiment 1]; and 12+/-2 [control] compared with 29+/-2 [BQ-123] and 25+/-2 [BQ-788], p < 0.003 and p < 0.002, respectively [Experiment 2]). The sensitivity of SVs to ACh was unaffected by treatment. These beneficial effects were specific for the endothelium.

CONCLUSIONS

Blockade of ET receptors significantly improves endothelial function in SVs. Furthermore, these effects appear to be independently and maximally mediated by antagonism of either ET(A) or ET(B) receptors. Interventions aimed at improving endothelial function may serve to counter perioperative vasospasm and impede atherosclerosis in SVs used for revascularization procedures.

Endovascular treatment of distally located giant aneurysms

OBJECTIVE

Because giant aneurysms (GAs) can be technically difficult to clip, the endovascular approach is becoming increasingly popular. Endovascular treatment of distally located GAs, which often requires parent vessel occlusion, is particularly challenging because limited pathways are available for collateral flow. We aimed to determine the outcomes of endovascular attempts to treat GAs downstream from the circle of Willis.

METHODS

Between 1991 and 1998, 27 patients with 27 distally located very large aneurysms or GAs were evaluated for possible endovascular treatment. Ten underwent selective embolization and 9 were treated with primary parent vessel occlusion, with or without distal bypass. Eight patients could not be treated endovascularly.

RESULTS

Selective embolization resulted in only one cure. Two patients died as a result of subarachnoid hemorrhage during the follow-up period. One coil-treated patient, who underwent subsequent spontaneous parent vessel occlusion, and all nine patients treated primarily with parent vessel occlusion were considered cured after their treatments. Only two patients treated with parent vessel occlusion experienced periprocedural ischemia, which did not result in a major deficit in either case. Of the eight patients who could not be treated endovascularly, one succumbed to surgery, four died while being treated conservatively, and three were lost to follow-up monitoring.

CONCLUSION

Selective aneurysm embolization is usually not curative in these situations. For selected patients, however, endovascular parent vessel occlusion is usually safe and effective in preventing the progression of symptoms and bleeding.

Clinical and angiographic results of endosaccular coiling treatment of giant and very large intracranial aneurysms: a 7-year, single-center experience

OBJECTIVE

To evaluate whether the objectives of surgical treatment, i.e., prevention of aneurysmal rebleeding, relief of aneurysmal mass effect, and prevention of embolic complications, are met by endosaccular coiling treatment applied to giant and very large wide-necked aneurysms.

METHODS

Thirty patients with 31 giant or very large aneurysms were considered to show unacceptable risk/benefit ratios for open surgery and were treated using the Guglielmi detachable coil (GDC) method between 1992 and 1998.

RESULTS

With endosaccular GDC treatment, 73.3% of the population experienced excellent to good recoveries (Glasgow Outcome Scale scores of 4 or 5), with a 13.3% procedure-related morbidity rate and a 6.7% procedure-related mortality rate. Two hemorrhaging episodes occurred after GDC treatment (annual bleeding rate, 2.5%; 2 hemorrhaging episodes/79.2 patient-yr). Symptoms related to aneurysmal mass effect were improved for 45.5% of the patients presenting with signs of neural compression. Among 23 patients with 24 aneurysms who were available for angiographic follow-up assessment, complete or nearly complete occlusion was observed for 17 aneurysms (71%; angiographic follow-up period, 24.3 +/- 19.6 mo, mean +/- standard deviation). A single total embolization served as definitive treatment for only 12.5% of the giant aneurysms and 31% of the very large aneurysms.

CONCLUSION

Endosaccular GDC treatment of giant and very large aneurysms was accomplished with procedure-related morbidity and mortality rates comparable to those for open surgery performed by experts. However, because coil stability was unsatisfactory, we suggest that the GDC method should currently be reserved for individuals who are considered poor candidates for open surgery.

Failure of a saphenous vein extracranial-intracranial bypass graft to protect against bilateral middle cerebral artery ischemia after carotid artery occlusion: case report

OBJECTIVE AND IMPORTANCE

We present the case of a patient who experienced bilateral middle cerebral artery infarctions after Hunterian ligation and trapping of a ruptured right cavernous aneurysm, despite a high-flow extracranial-intracranial bypass. This is a rare complication, and it highlights the need for further refinements in our understanding of the hemodynamic insufficiency created by major vessel sacrifice.

CLINICAL PRESENTATION

The patient was a 59-year-old woman who experienced multiple episodes of massive epistaxis before undergoing angiography, which revealed left internal carotid artery occlusion and an irregular right cavernous aneurysm. The patient was then transferred to our center for treatment. The patient was neurologically intact at presentation, and her epistaxis was controlled by nasal packing.

INTERVENTION

The patient underwent an extracranial-intracranial bypass from the external carotid artery to the M2 segment of the right middle cerebral artery, followed by trapping of the aneurysm. Despite evidence of graft patency, the patient experienced bilateral middle cerebral artery distribution infarctions after surgery.

CONCLUSION

Although extracranial-intracranial bypasses protect the majority of patients who undergo carotid artery ligation from ischemic complications, this case demonstrates that hemodynamic insufficiency can occur even with a high-flow saphenous vein graft. Better ways to quantitate the hemodynamic needs of the brain after major vessel sacrifice may facilitate matching of the revascularization strategy to the specific needs of each patient, thus further reducing the likelihood of ischemic complications.

End-to-end anastomosis of the posterior inferior cerebellar artery before excision of a meningioma involving the lower clivus and the foramen magnum. Case report

BACKGROUND

Petroclival and foramen magnum meningiomas sometimes encase the vertebrobasilar arterial system. Magnetic resonance imaging can clearly reveal such encasement. The case presented here was of a meningioma involving the lower clivus and the foramen magnum, encasing a lateral segment of the posterior inferior cerebellar artery (PICA), despite the fact that no definitive diagnosis of the encasement of the PICA was made on preoperative radiological examination. End-to-end anastomosis of the PICA was necessary before excision of the tumor.

METHODS

A 55-year-old woman presented with complaints of headache and numbness of the right upper extremity. Gadolinium diethylene-thiamine-pentaacetic acid enhanced T1-weighted magnetic resonance (MR) images showed a homogeneously enhanced mass lesion involving the lower clivus and the foramen magnum. Direct surgery was then performed, and the lateral medullary segment of the left PICA was found to be encased by the tumor. End-to-end anastomosis was performed using No. 10-0 interrupted monofilament nylon sutures. Total removal of the tumor was performed after completion of the anastomosis. The patient was free of neurological abnormalities and no recurrence of tumor was found during a 2-year follow-up period.

CONCLUSIONS

Revascularization is sometimes thought to be required for resection of craniospinal meningiomas even when they do not appear to encase the vertebro-basilar arterial system on preoperative MR imaging and cerebral angiograms. In the present case, dissection of the PICA from the tumor was attempted, but was difficult due to tight encasement of the PICA by the tumor.

The posterior temporal artery as the recipient in superficial temporal artery to posterior cerebral artery bypass. Technical note

BACKGROUND

While superficial temporal artery (STA) to superior cerebellar artery (SCA) or STA to posterior cerebral artery (PCA) anastomosis has been used for rostral brain stem ischemia, it is reported not infrequently to be associated with serious complications. Although the inferior temporal artery has been proposed as a possible recipient artery for the STA, its advantage is not yet widely recognized.

CASE REPORT

A 42-year-old man presented with repeated loss of vision in the left visual field. Angiography disclosed occlusion in the proximal portion of the P2 segment of the right PCA. The second case was a 68-year-old man experiencing swallowing disturbance; the bilateral vertebral arteries were markedly stenotic. Since hemodynamic insufficiency was considered to be responsible for the patients' symptoms, STA-PCA anastomosis was performed using the posterior temporal artery (PTA) as the recipient. The postoperative courses were uneventful with good patency of the bypass.

TECHNIQUE

Through a horizontally extended temporal craniotomy with the base of the temporal bone sufficiently drilled away, the inferior aspect of the temporal lobe was searched for a recipient artery for the STA. The anastomosis was performed with less difficulty and at a shallower level, by 20 mm in one case and by 10 mm in the other, than had we anastomosed it to the P2 segment of the PCA.

CONCLUSION

Anastomosis of the STA to the PTA is less complicated than anastomosis of the STA to the main branch of the PCA for the treatment of rostral brain stem ischemia.

Venous and arterial bypass grafts for difficult tumors, aneurysms, and occlusive vascular lesions: evolution of surgical treatment and improved graft results

OBJECTIVE: In the treatment of patients with cranial base tumors, unclippable aneurysms, or medically intractable ischemia, it may be necessary to use high-flow bypass grafts. The indications, surgical techniques and complications are discussed. METHODS: During a 10-year period, 99 saphenous vein grafts and 3 radial artery grafts were performed for 101 patients, i.e., 72 with neoplasms, 23 with aneurysms, and 6 with ischemia. Clinical follow-up monitoring of the patients was by direct examination or telephone interview, with a mean follow-up period of 41.2 months (range, 5-147 mo). Radiological follow-up monitoring was by magnetic resonance imaging, magnetic resonance angiography, or three-dimensional computed tomographic angiography, with a mean follow-up period of 32 months (range, 1-120 mo). During the follow-up period, there was one late graft occlusion and one graft stenosis. RESULTS: The use of intraoperative angiography improved the patency rate from 90 to 98% and reduced the incidence of perioperative stroke from 13 to 9.5%. Ninety-two percent of the patients were in excellent or good neurological condition at the time of discharge from the hospital, compared with 95% before surgery. The perioperative mortality rate was 2%. Other complications included three intracranial hematomas, rupture of a vein graft in a patient with Marfan's syndrome, and five tumor resection-related problems. The long-term survival rates for patients who received grafts were excellent for patients with benign tumors, fair to poor for patients with malignant tumors, good for patients with aneurysms, and excellent for patients with ischemia. CONCLUSION: The results of saphenous vein and radial artery grafting have been greatly improved by the use of intraoperative angiography, improvements in surgical techniques, and improved perioperative treatment.

Surgical treatment of anterior circulation aneurysms

The purpose of this paper is to present the results, assessed by an independent observer, of surgical treatment of 428 consecutive patients harbouring aneurysms of the anterior circulation, together with a review of relevant anatomy and operative strategy. At follow-up (mean 5.6 years) 89.3% lived at home and were independent, 5.1% lived at home but needed some kind of assistance, 2.0% lived in institution, whereas information was unavailable in 3.6% of living patients. Two hundred and fifty-three patients (64.5%) had unchanged employment status, 0.3% worked in sheltered environment, whereas 30.9% went out of work due to their subarachnoid hemorrhage (SAH). Information about employment status was unavailable in 4.3%. For aneurysms of the internal carotid, anterior communicating and middle cerebral artery, respectively, mortality was 3.2, 3.9 and 5.6%, whereas 92.0, 88.1 and 89.0% of surviving patients lived at home and were independent and 67.0, 63.6 and 63.0% had unchanged employment status. Three-months mortality of all causes was 4.2%. In the postoperative period 53 (12.4%) patients developed clinical signs of vasospasms, 6 (1.4%) had cardiac infarction, 4 (0.9%) lung oedema, 4 (0.9%) deep vein thrombosis, and 7 patients (1.6%) infection. During the follow-up period shunt-dependent hydrocephalus developed in 4.2% and 0.2% had a subsequent SAH from the same aneurysm. Forty-three patients were on anticonvulsive therapy.

Surgical strategies for giant intracranial aneurysms

Untreated giant intracranial aneurysms have a dismal natural history as a result of hemorrhage, cerebral compression, and thromboembolism. The poor prognosis of patients with giant aneurysms therefore warrants aggressive treatment. A surgical approach is chosen to maximize the operative exposure of the aneurysm and depends mainly on the aneurysm's location. Once exposed, vascular control of the aneurysm is required not only to manage an intraoperative rupture, but also to collapse the aneurysm, to increase working space, and to improve visualization of the anatomy. Hypothermic circulatory arrest may be indicated in select patients with complex posterior circulation aneurysms. Direct clipping of giant aneurysms, with meticulous preservation of parent and branch arteries, is the preferred method of occlusion. Unclippable aneurysms require alternative techniques (e.g., trapping, parent artery occlusion, excision, and aneurysmorrhaphy) that compromise parent arteries and may require revascularization to restore adequate cerebral blood flow. Giant aneurysms are complex lesions that demand thorough surgical planning, individualized strategies, and a multidisciplinary effort in specialized neurovascular centers.

Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery. Technical note

Reconstruction of the carotid artery by using a radial artery graft is a useful option that can produce reliable long-term patency for the surgical treatment of giant and/or large aneurysms of the cavernous and paraclinoid internal carotid artery (ICA). During the past 10 years, 43 patients with intracavernous and paraclinoid giant aneurysms of the ICA have been treated by reconstruction of the ICA with radial artery grafts after ligation of the cervical ICA. The long-term patency of the grafted radial artery was evaluated over more than a 5-year period (mean 7.2 years) in 20 of these patients by using magnetic resonance angiography or conventional angiography. There was no late occlusion of the graft in any of these cases. Stenotic graft changes were observed in two cases.

Treatment of a Giant Aneurysm of the Right Middle Cerebral Artery with GDCs after Extracranial to Intracranial Bypass. A Technical Case Report

SUMMARY

A case of a giant aneurysm of the right middle cerebral artery treated with Guglielmi detachable coils is reported. Extracranial to intracranial bypass had previously been performed and surgical trapping had been attempted. During the endovascular procedure, balloon test occlusion of the middle cerebral artery was performed in order to demonstrate clinical and angiographic tolerance to parent vessel occlusion. A previous occlusion test in the right common carotid artery did not show sufficient flow through the bypass to perform safe parent vessel occlusion. Diagnostic imaging, the endovascular procedure, and haemodynamic aspects in cases in which parent vessel occlusion is required after extracranial-intracranial bypass are described and the literature is reviewed.

Delayed thrombus propagation after parent artery clipping for giant fusiform aneurysms of the circle of Willis

BACKGROUND

Obliteration of a giant fusiform aneurysm without significant therapeutic morbidity is extremely difficult. Ischemic complications have been often reported.

METHODS

Two patients with giant fusiform aneurysms of the circle of Willis are presented. Both patients underwent proximal parent artery clipping after a bypass procedure. Balloon occlusion tests confirmed both patients' ability to tolerate flow reduction after proximal clipping.

RESULTS

Although both patients awoke from anesthesia without neurologic deficit, they developed contralateral hemiparesis several hours after the operation as a result of a small infarct in the basal ganglia. These ischemic events might be attributed to the delayed thrombosis involving the orifice of the distal perforating arteries.

CONCLUSIONS

In the treatment for giant fusiform aneurysms of the circle of Willis, special attention should be paid not only to flow reduction, but also to delayed thrombus propagation that may not be predicted by preoperative balloon occlusion testing.

Intracranial vascular anastomosis using the microanastomotic system. Technical note

The authors describe the use of a microanastomotic device to perform intracranial end-to-end vascular anastomoses. Direct end-to-end anastomosis was performed between the superficial temporal artery and branches of the middle cerebral artery (MCA) in three patients. Two patients had moyamoya disease, with severe proximal MCA disease, and one suffered an internal carotid artery occlusion with poor collateral flow. All patients reported a history of recent ischemic symptoms. Each anastomosis was accomplished in less than 15 minutes with technically satisfactory results. Postoperative angiographic studies demonstrated patency of the bypasses in all patients.

Long-term graft patency rates and clinical outcomes after revascularization for symptomatic traumatic internal carotid artery dissection

INTRODUCTION

Surgical management of traumatic internal carotid artery (ICA) dissection remains controversial. Therefore, the delayed outcomes and graft patency rates of patients who underwent bypass procedures for symptomatic traumatic ICA dissection were studied.

METHODS

Between September 1989 and August 1996, 13 patients (9 male and 4 female patients; mean age, 30.6 yr) underwent 16 revascularization procedures for symptomatic traumatic ICA dissection. The duration of clinical follow-up averaged 47.3 months (range, 12-94 mo) from the date of diagnosis. The duration of radiographic follow-up (catheter or magnetic resonance angiography, duplex Doppler ultrasonography) averaged 24 months (range, 12-60 mo).

RESULTS

ICA dissection was caused by blunt (n = 11) or penetrating trauma (n = 2). Associated angiographic abnormalities included seven ipsilateral ICA occlusions, six dissecting aneurysms, two carotid-cavernous fistulae, and six contralateral traumatic ICA dissections. Patients requiring early revascularization (n = 6) underwent bypass procedures an average of 19.2 days after their injuries. Medically managed patients who developed ischemia later were revascularized a mean of 7.8 months after injury. The mean Glasgow Coma Scale score at the time of presentation was 10 (range, scores of 6-15), and the mean Glasgow Coma Scale score before revascularization was 14 (range, scores of 9-15). There were 14 saphenous vein ICA bypasses (8 cervical-to-petrous, 3 cervical-to-middle cerebral artery, 3 petrous-to-supraclinoid) and 2 superficial temporal artery-to-middle cerebral artery bypasses. There was one early postoperative graft occlusion, which responded to surgical thrombectomy. One patient with multiple other traumatic injuries died as a result of a pulmonary embolus 12 months after revascularization. All remaining patients had Glasgow Outcome Scale scores of 5, with patent bypass grafts confirmed during follow-up.

CONCLUSION

Revascularization for persistently symptomatic traumatic ICA dissection eliminated ischemia and was associated with excellent long-term outcomes and graft patency rates.

Vascular reconstruction using interposed small vessels

OBJECTIVE

This study presents the relationship between the patency of short-vessel graft bypasses and their diameter/length.

METHODS

The authors performed interposed graft bypass operations using small vessels for four patients with moyamoya disease, six patients with cerebral thrombosis, and one patient with aortitis syndrome. The donor artery was the superficial temporal artery (10 patients) or the occipital artery (1 patient), and the recipient artery was the cortical branch of the middle cerebral artery (8 patients) or the cortical branch of the anterior cerebral artery (3 patients). The interposed graft used between these donor and recipient vessels was the superficial temporal vein (seven patients), the superficial temporal artery (three patients), or the epigastric artery (one patient).

RESULTS

Good patency of the graft was confirmed for 7 of these 11 patients. Regarding the relationship between the diameter/length and the patency, we found that long-term patency could not be expected when the discriminant function of y = (15.39 x diameter) - (0.35 x length) - 14.37 was below zero.

CONCLUSION

Short-vessel graft bypass is a practical option for cerebral revascularization surgery when short large vessels are used.

Giant aneurysms of the middle cerebral artery trifurcation treated with extracranial-intracranial arterial bypass and endovascular occlusion. Report of two cases

Giant middle cerebral artery (MCA) trifurcation aneurysms that cannot be excluded directly can be treated by flow inversion achieved by creation of an extracranial-intracranial bypass distal to the aneurysm, followed by occlusion of the parent vessel proximal to the aneurysm. As opposed to surgical occlusion, endovascular occlusion avoids dissection of the aneurysm area, and the site of occlusion can be chosen according to the flow distribution demonstrated on angiography performed during test occlusions. Two patients with giant aneurysms of the MCA trifurcation benefited from flow inversion treatment. Forty-eight hours after an MCA-superficial temporal artery bypass had been created, the M1 segment was occluded by inserting a coil in the first patient and the internal carotid artery was occluded with balloons in the second patient (there was no communicating artery in the latter case). Both occlusions were performed immediately after a clinical test of occlusion tolerance. The patients were clinically intact during the postoperative course. Follow-up angiography performed 11 and 4 months, respectively, after vessel occlusion showed that the aneurysm occlusion was stable.

Hypothermic circulatory arrest in neurovascular surgery: evolving indications and predictors of patient outcome

OBJECTIVE

One of the largest contemporary neurosurgical experiences with hypothermic circulatory arrest was analyzed for trends in patient selection and clinical variables affecting outcome.

METHODS

During a 12-year period, 60 patients underwent 62 circulatory arrest procedures: 54 had posterior circulation aneurysms, 4 had anterior circulation aneurysms, and 2 had other lesions (hemangioblastoma and vertebral artery atherosclerosis).

RESULTS

The surgical morbidity and mortality rates associated with hypothermic circulatory arrest were 13.3 and 8.3%, respectively. At late follow-up, 76% of the patients had good outcomes (Glasgow Outcome Scale scores of 1 and 2), 5% had poor outcomes (Glasgow Outcome Scale scores of 3 and 4), and 18% had died. After 1992, circulatory arrest was limited to posterior circulation aneurysms and included increasing numbers of basilar trunk aneurysms. Patient outcome correlated with preoperative neurological condition (admission Glasgow Coma Scale score, P < 0.001; Hunt and Hess grade, P = 0.037; and age, P = 0.007). Preservation of perforating arteries was paramount to achieving a good outcome (P = 0.005); duration of circulatory arrest was not.

CONCLUSION

Current indications for hypothermic circulatory arrest include only giant and complex posterior circulation aneurysms that cannot be treated using conventional techniques or that recur after endovascular coiling. Surgical morbidity and mortality rates reflect the increasing complexity of the aneurysms treated but are still more favorable than the natural history of these lesions. This experience demonstrates that management in specialized neurovascular centers can minimize the morbidity associated with circulatory arrest so that it remains a viable treatment option for complex posterior circulation aneurysms.

Obliteration of a giant carotid aneurysm after extracranial-to-intracranial bypass surgery: case report

BACKGROUND

Proximal arterial occlusion, with or without extracranial-to-intracranial (EC-IC) bypass, is frequently used as treatment for giant intracranial aneurysms that are unclippable. The authors report on a patient who had obliteration of a giant unruptured aneurysm of the right internal carotid terminus after undergoing an EC-IC bypass without proximal arterial ligation.

METHODS

This 71-year-old woman presented with repeated right cerebral ischemia caused by a giant saccular aneurysm of the right internal carotid terminus. Direct surgical clipping of the aneurysm was not recommended because of the patient's age and because of the morphology of the aneurysm. She could not tolerate occlusion of the right internal carotid artery (ICA) and, therefore, first underwent an EC-IC bypass. Four weeks later, she returned to undergo a balloon occlusion of the right ICA proximal to the aneurysm.

RESULTS

The right distal ICA and aneurysm were found to be spontaneously thrombosed. At 2-year follow-up, the aneurysm was shown to be completely obliterated on the magnetic resonance imaging scans.

CONCLUSIONS

The authors conclude that hemodynamic changes in the blood flow of the parent artery after EC-IC bypass caused this occurrence.

Juvenile active ossifying fibroma. Report of four cases

Juvenile active ossifying fibroma is a rare lesion seldom seen by neurosurgeons. It originates in the paranasal sinuses during childhood, grows slowly, and encroaches on adjacent orbital and cranial compartments. In the past 3 years, four patients with this lesion were seen (three men and one woman; mean age 28 years). The clinical presentations were different with each patient: sinusitis, meningitis, periorbital pain, and a unique case of a juvenile active ossifying fibroma presenting with high-grade internal carotid artery stenosis and ischemic symptoms. Three patients were treated by transfacial approaches: two with a transfrontal-nasal approach and one with a transfrontal-nasoorbital approach. Two open resections resulted in gross-total excision and no recurrence as of the 2-year follow-up review. In the third patient, the tumor-encased carotid artery was preserved at the expense of a complete resection; that patient underwent superficial temporal artery-middle cerebral artery bypass and remains without ischemic symptoms or tumor recurrence at 2 years. The fourth patient underwent three subtotal endoscopic resections and is also without symptomatic recurrence at 2 years. Three points must be made concerning these lesions. First, the clinical and radiographic characteristics of juvenile active ossifying fibroma may not be easily recognized by neurosurgeons, which could lead to misdiagnosis and mismanagement of these lesions. Second, this tumor can encase the carotid artery and cause severe stenosis or occlusion. Third, complete resection of the tumor is required to effect a cure, and transfacial approaches, which give wide exposure of the sinuses, appear to yield better, more radical resections than endoscopic procedures.

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.