Preoperative selective internal carotid artery dural branch embolisation for petroclival meningiomas

Tumor Embolization via the Meningohypophyseal and Inferolateral Trunk in Patients with Skull Base Tumors Using the Distal Balloon Protection Technique

BACKGROUND AND PURPOSE

Tumor embolization through the meningohypophyseal trunk and inferolateral trunk is known to be effective in skull base tumors; however, microcatheter cannulation into these arteries is difficult, and the number of cases that can be safely embolized is limited. In this study, we present a novel embolization procedure for the meningohypophyseal trunk and inferolateral trunk using the distal balloon protection technique and detail its clinical efficacy and complication risks. We developed this procedure to allow safe embolization in patients who cannot be adequately cannulated with microcatheters into these arteries.

MATERIALS AND METHODS

Patients who underwent meningohypophyseal trunk or inferolateral trunk embolization using the distal balloon protection technique for skull base tumors at our institution between 2010 and 2023 were included. In this procedure, the ICA was temporarily occluded with a balloon at the ophthalmic artery bifurcation, the microcatheter was guided to the meningohypophyseal trunk or inferolateral trunk vicinity, and embolic particles were injected into the arteries. The balloon was deflated after the embolic particles that had refluxed into the ICA were aspirated.

RESULTS

A total of 25 meningohypophyseal trunks and inferolateral trunks were embolized during 21 operations. Of these 25 arteries, only 9 (36.0%) were successfully cannulated with microcatheters. Nevertheless, effective embolization was achieved in all cases. Permanent complications occurred in only 1 case (4.8%) in which the central retinal artery was occluded during inferolateral trunk embolization, resulting in a visual field defect. No permanent complications resulting from the embolic cerebral infarction were observed. Of 16 cases that underwent MR imaging within a week after embolization, however, 11 (68.8%) demonstrated embolic cerebral infarctions.

CONCLUSIONS

In patients with skull base tumors with meningohypophyseal trunk or inferolateral trunk feeders that cannot be catheterized directly, embolization using the distal balloon protection technique for tumor supply can be considered as a salvage technique.

[Clinical anatomy of the Bernasconi-Cassinari artery]

The article provides a comprehensive overview of the Bernasconi-Cassinari's artery (marginal tentorial branch of internal carotid artery, r. marginalis tentorii a. carotis internae). It includes information on the history of its discovery, anatomical features, and topography. The interrelation between the anatomical features of this artery and the presence of neurological pathology in patients is discussed, along with neurosurgical treatment methodologies.

Endovascular Embolization of Intracranial Meningiomas

Although benign in histology, the hypervascularity and skull base location of meningiomas can make them surgically challenging lesions. Preoperative endovascular embolization with superselective microcatheterization of vascular pedicles may be efficacious in decreasing intraoperative transfusion requirements with equivocal postoperative functional benefit. The potential benefits of preoperative embolization should be weighed against the risks of ischemic complications. Appropriate patient selection is critical. All patients should be monitored closely postembolization, and a course of steroids can be considered to minimize neurologic symptoms.

Tumor Embolization through Meningohypophyseal and Inferolateral Trunks is Safe and Effective

BACKGROUND AND PURPOSE

Skull base tumors are commonly supplied by dural branches of the meningohypophyseal and inferolateral trunks. Embolization through these arteries is often avoided due to technical challenges and inherent risks; however, successful embolization can be a valuable surgical adjunct. We aimed to review the success and complications in our series of tumor embolizations through the meningohypophyseal and inferolateral trunks.

MATERIALS AND METHODS

We performed a retrospective review of patients with tumor treated with preoperative embolization at our institution between 2010 and 2020. We reviewed the following data: patients' demographics, tumor characteristics, endovascular embolization variables, and surgical results including estimated blood loss, the need for transfusion, and operative time.

RESULTS

Among 155 tumor embolization cases, we identified 14 patients in whom tumor embolization was performed using the meningohypophyseal (n = 13) or inferolateral (n = 4) trunk. In this group of patients, on average, 79% of tumors were embolized. No mortality or morbidity from the embolization procedure was observed in this subgroup of patients. The average estimated blood loss in the operation was 395 mL (range, 200-750 mL). None of the patients required a transfusion, and the average operative time was 7.3 hours.

CONCLUSIONS

Some skull base tumors necessitate embolization through ICA branches such as the meningohypophyseal and inferolateral trunks. Our series demonstrates that an effective and safe embolization may be performed through these routes.

Long-term outcome of Simpson IV meningioma resection: Would it improve with adjuvant SRS?

OBJECTIVE

Subtotal meningioma resection (STR) is often performed to minimize surgical morbidity. Nevertheless, only a few studies have reported on patient outcome after STR. We studied the long-term outcome of SIV (Simpson grade IV) resection and identified predictive factors of overall survival (OS), progression-free survival (PFS) and time to progression (TTP).

METHODS

A retrospective analysis was performed on 68 patients who underwent SIV resection of meningioma (grade I) from 2004 to 2010. Data were collected from clinical, surgical and pathology records and radiological imaging. Long-term outcomes were evaluated at least 10 years after surgery.

RESULTS

Permanent morbidity was 11.8%, 30-day mortality 2.9% and progression rate 50.0% for a median follow-up duration of 126.6 months. Median TTP was 86.2 months. Adjuvant SRS was the only significant factor associated with longer PFS (p = 0.0052) and TTP (p = 0.0079). Higher age (p = 0.0022), KPS (p = 0.0182), postoperative ECOG score (p = 0.0182) were reliable predictors of shortened OS and aSRS (p = 0.0445) was reliable predictor of longer OS.

CONCLUSION

STR in intracranial meningioma is still viable and often the only treatment option available in high-risk patients or high-risk tumors. Although surgical morbidity and mortality are high, the OS rate was 85.3% at 5 years and 79.4% at 10 years. Because of the considerable progression rate and rather a long term OS the adjuvant SRS should be considered following SIV resection.

Pterygovaginal artery as a target of embolization before endoscopic skull base surgery

BACKGROUND

The pterygovaginal artery (PtVA), a recurrent branch of the internal maxillary artery (IMA), can be a feeder of skull base tumors. Preoperative embolization can help endoscopic resection of hypervascular lesions, which is performed under a narrow surgical space with restricted instrumental maneuverability.

METHODS

We performed preoperative embolization in five cases with hypervascular skull base lesions supplied by the PtVA, four of which were resected via endoscopic endonasal approach. In two cases, selective PtVA embolization through the distal IMA was successfully conducted.

RESULTS

In all the cases, intraoperative bleeding during endoscopic resection was easily controlled. The medial and lateral origins of the PtVA from the IMA were demonstrated by cone-beam CT images reconstructed from three-dimensional rotational angiography, and anastomoses around the eustachian tube and soft palate were visualized by superselective angiography.

CONCLUSIONS

The PtVA embolization can be an effective strategy before endoscopic skull base tumor resection. When embolizing through the PtVA, clinicians should be aware of its anatomical variations and dangerous anastomoses. Understanding the surrounding angioarchitecture by angiographic techniques helps ensure safe embolization.

Does preoperative embolization improve outcomes of meningioma resection? A systematic review and meta-analysis

Current evidence regarding the benefit of preoperative embolization (POE) of meningiomas is inconclusive. This systematic review and meta-analysis aims to evaluate the safety profile of the procedure and to compare outcomes in embolized versus non-embolized meningiomas. PubMed was queried for studies after January 1990 reporting outcomes of POE. Pertinent variables were extracted and synthesized from eligible articles. Heterogeneity was assessed using I², and random-effects model was employed to calculate pooled 95% CI effect sizes. Publication bias was assessed using funnel plots and Harbord's and Begg's tests. Meta-analyses were used to assess estimated blood loss and operative duration (mean difference; MD), gross-total resection (odds ratio; OR), and postsurgical complications and postsurgical mortality (risk difference; RD). Thirty-four studies encompassing 1782 preoperatively embolized meningiomas were captured. The pooled immediate complication rate following embolization was 4.3% (34 studies, n = 1782). Although heterogeneity was moderate to high (I² = 35-86%), meta-analyses showed no statistically significant differences in estimated blood loss (8 studies, n = 1050, MD = 13.9 cc, 95% CI = -101.3 to 129.1), operative duration (11 studies, n = 1887, MD = 2.4 min, 95% CI = -35.5 to 30.8), gross-total resection (6 studies, n = 1608, OR = 1.07, 95% CI = 0.8-1.5), postsurgical complications (12 studies, n = 2060, RD = 0.01, 95% CI = -0.04 to 0.07), and postsurgical mortality (12 studies, n = 2060, RD = 0.01, 95% CI = 0-0.01). Although POE is relatively safe, no clear benefit was observed in operative and postoperative outcomes. However, results must be interpreted with caution due to heterogeneity and selection bias between studies. Well-controlled future investigations are needed to define the patient population most likely to benefit from the procedure.

Petroclival meningiomas: the risk of post-operative cranial nerve deficits among different surgical approaches-a systematic review and meta-analysis

BACKGROUND

The surgical resection of petroclival meningiomas (PCMs) remains a challenge. Both the relationship with neurovascular structures and the deep location of the tumor can affect the extent of resection and the rate of post-operative morbidity.

METHODS

The authors performed a systematic review and meta-analysis of the literature examining the rate of new cranial nerve (CN) deficits after resection of PCM. A systematic search of two databases was performed for studies published between 1990 and 2018. Random-effect meta-analysis was used to pool the rate of post-operative CN deficits, mortality rate, and rate of radical resection.

RESULTS

We included twelve studies and 334 patients harboring PCM. The overall rate of complete resection was 68% (95% CI 57.9-78.2%; p < 0.01; I² = 83%). The rate of early and late post-operative CN deficits was the following: 3.8 and 2.7% (III CN), 6.6 and 3% (IV), 7.3 and 5.5% (V CN), 8 and 3.6% (VI CN), 8.9 and 8.9%% (VIII), and 4 and 2.7% (IX-XI CNs) (I² = 0%, and p < 0.01 for all analyses). The risk of post-operative deficit of the IV CN was higher among the petrosal group (7.6%; I² = 0% vs 2.1%; I² = 0%), whereas the impairment of VII CN function was higher among retrosigmoid group (16.6%; I² = 64.6% vs 11.4%; I² = 52.8%), but it was transient in the majority of cases.

CONCLUSIONS

This systematic review and meta-analysis provides a detailed overview of post-operative CN deficits ensuing surgical resection of PCMs. These findings should be acknowledged when counseling patients with PCMs regarding the more appropriate approach for their tumor.

Transarterial Embolization of a Parasellar Hypervascular Tumor

Embolization of hypervascular tumors has been widely performed for over four decades, particularly for preoperative meningioma. Several benefits of preoperative embolization have been reported, including reduced blood loss, surgical time and surgical complications, and improved outcomes. However, the technical details of both embolization and surgical procedures, and lesions widely vary. Thus, the actual benefits of preoperative embolization have not been clarified by prospective randomized studies. Procedure-related complications due to embolization developed in 3%-12% in previous studies. For parasellar lesions, both surgical resection and embolization have a higher risk of complication than for lesions at other locations because of the complicated neurovascular anatomy in the parasellar area. Therefore, close attention should be paid to the detailed vascular anatomy, embolic material, and related information for embolization and resection in individual cases to improve patient outcomes.

[Treatment of petroclival meningiomas: current state of the problem]

Petroclival meningiomas (PCMs) are benign, slowly growing tumors. Surgery still remains the main treatment option for them. The desire for total resection of large extended PCMs often leads to the development or worsening of persistent neurological deficits. This paper presents a review of the world literature devoted to petroclival meningiomas. We discuss the issues of PCM classification, biology, diagnosis, and selection of the optimal algorithm for their treatment.

Preoperative embolization of skull base meningiomas: current indications, techniques, and pearls for complication avoidance

Skull base meningiomas are technically challenging tumors to treat because of their deep vascular supply that can preclude early devascularization during resection. Preoperative embolization of these arterial feeders is thought to decrease blood loss and facilitate resection; however, given the complex and varied anatomy of these skull base lesions, preoperative embolization is not without risk. It is essential for both endovascular and skull base neurosurgeons to understand these risks in light of the potential benefits. The authors review the vascular anatomy of skull base meningiomas, indications for preoperative devascularization, endovascular techniques, and published results regarding embolization of these lesions.

Petroclival meningiomas: Remaining controversies in light of minimally invasive approaches

Surgical resection of petroclival meningiomas remains challenging due to their deep location and relationship to vital neurovascular structures. Although the natural history of these tumors involves a slow course, the incidence of cranial nerve deficits and the extent of tumor resection vary widely in the literature. Some reviews on this topic have been conducted, but data remain fragmentary and based on retrospective case series, which hinders attempts at meta-analysis. Within this context, research into the use of minimally invasive approaches, including in neuroendoscopy, continues to emerge. The objective of this narrative review is to analyze the available literature on the surgical treatment of petroclival meningiomas, with a focus on attempts at endoscopy-assisted resection.

Safety and efficacy of medium-sized particle embolisation for skull-base meningioma

AIM

To determine the effectiveness and safety of preoperative tumour embolisation for skull-base meningiomas via external carotid artery (ECA) feeders using medium-sized (150-250 μm) polyvinyl alcohol (PVA) particles.

MATERIALS AND METHODS

This study included 114 consecutive patients with skull-base meningiomas who underwent preoperative tumour embolisation using medium-sized PVA particles from January 2004 to December 2013. Tumours were categorised according to feeding artery as follows: type 1, tumour staining at ECA angiography only; type 2, tumour staining at both the ECA and internal carotid artery (ICA) angiography; or type 3, little or no tumour staining at ECA angiography. The effectiveness was based on the percent reduction in the enhanced area: >75% was considered effective, 25-75% was considered partially effective, and <25% was considered ineffective.

RESULTS

Tumour embolisation was performed in patients with dominant feeding vessels originating from the ECA. Procedural-related complications occurred in two (1.8%) patients. Post-procedural MRI images were available for 51 patients, which revealed effective embolisation in only 13 (25.5%) patients. Identification of an ICA feeding vessel was associated with ineffective embolisation (p=0.011). Effective embolisation was associated with low estimated blood loss during surgery.

CONCLUSION

ECA embolisation using medium-sized PVA is ineffective in patients in whom a definitive ICA feeding vessel was identified, even if preprocedural angiography showed that the dominant feeder originated from the ECA. When the risks of surgical morbidity and mortality are expected to be high, ICA feeder embolisation should also be considered.

Preoperative embolization of intracranial meningiomas: efficacy, technical considerations, and complications

BACKGROUND AND PURPOSE

Preoperative embolization for intracranial meningiomas offers potential advantages for safer and more effective surgery. However, this treatment strategy has not been examined in a large comparative series. The purpose of this study was to review our experience using preoperative embolization to understand the efficacy, technical considerations and complications of this technique.

MATERIALS AND METHODS

We performed a retrospective review of patients undergoing intracranial meningioma resection at our institution (March 2001 to December 2012). Comparisons were made between embolized and nonembolized patients, including patient and tumor characteristics, embolization method, operative blood loss, complications, and extent of resection. Logistic regression analyses were used to identify factors predictive of operative blood loss and extent of resection.

RESULTS

Preoperatively, 224 patients were referred for embolization, of which 177 received embolization. No complications were seen in 97.1%. There were no significant differences in operative duration, extent of resection, or complications. Estimated blood loss was higher in the embolized group (410 versus 315 mL, P=.0074), but history of embolization was not a predictor of blood loss in multivariate analysis. Independent predictors of blood loss included decreasing degree of tumor embolization (P=.037), skull base location (P=.005), and male sex (P=.034). Embolization was not an independent predictor of gross total resection.

CONCLUSIONS

Preoperative embolization is a safe option for selected meningiomas. In our series, embolization did not alter the operative duration, complications, or degree of resection, but the degree of embolization was an independent predictor of decreased operative blood loss.

The role of preoperative embolization for intracranial meningiomas

Object

As endovascular techniques have become more advanced, preoperative embolization has become an increasingly used intervention in the management of meningiomas. To date, however, no consensus has been reached on the use of this technique. To clarify the role of preoperative embolization in the management of meningiomas, the authors conducted a systematic review of case reports, case series, and prospective studies to increase the current understanding of the management options for these common lesions and complications associated with preoperative embolization.

Methods

A PubMed search was performed to include all relevant studies in which the management of intracranial meningiomas with preoperative embolization was reported. Immediate complications of embolization were reported as major (sustained) or minor (transient) deficits, death, or no neurological deficits.

Results

A total of 36 studies comprising 459 patients were included in the review. Among patients receiving preoperative embolization for meningiomas, 4.6% (n = 21) sustained complications as a direct result of embolization. Of the 21 patients with embolization-induced complications, the incidence of major complications was 4.8% (n = 1) and the mortality rate was 9.5% (n = 2).

Conclusions

Preoperative embolization is associated with an added risk for morbidity and mortality. Preoperative embolization may be associated with significant complications, but careful selection of ideal cases for embolization may help reduce any added morbidity with this procedure. Although not analyzed in the authors' study, embolization may still reduce rates of surgical morbidity and mortality and therefore may still have a potential benefit for selected patients. Future prospective studies involving the use of preoperative embolization in certain cases of meningiomas may further elucidate its potential benefit and risks.

Risks of presurgical embolization of feeding arteries in 137 intracranial meningeal tumors

BACKGROUND

Embolization of extra-axial tumors has shown its effectiveness in reducing perisurgical blood loss. However, the complication rate of this procedure is poorly reported. We aimed to evaluate the rate of procedure-related complications and their risk factors.

METHODS

From 1998 to 2011, 193 consecutive patients (141 females, 52 males; mean age = 52.9 years) were referred to our institution for presurgical embolization of an extra-axial tumor (meningiomas: n = 178; solitary fibrous tumors: n = 3; other: n = 12). Of 193 patients, 137 (71 %) underwent 141 embolizations (by microparticles: n = 133; by glue: n = 8). The remaining 56 patients (29 %) were not embolized due to unstable catheterization or dangerous anastomosis. Occurrence of neurological deficit was systematically assessed during and after embolization. The risk factors of procedure-related neurological complications were evaluated.

RESULTS

Neither intratumoral hemorrhage nor procedure-related death was reported. Two of the 137 patients (1.5 %) had ischemic events with permanent neurological deficit after microparticles embolization. One patient had cortical blindness and one had hemiparesis. Both complications involved the vertebrobasilar system. The first patient had direct intratumoral anastomosis between the middle and the posterior meningeal arteries (PMA); the second one had reflux in the vertebral artery during particles injection in the PMA. Occurrence of ischemic complication was not related to the size of the microparticles.

CONCLUSIONS

Though embolization of meningeal tumors is considered as a safe technique, serious neurological complications may occur. Opening of dangerous anastomosis or uncontrolled reflux caused two neurological complications (1.5 %). The size of the microparticles was not associated with the occurrence of neurological event.

Tentorial detachment technique in the combined petrosal approach for petroclival meningiomas

OBJECT

The combined petrosal approach is a suitable technique for the resection of medium-to-large petroclival meningiomas (PCMs). Multiple technical modifications have been reported to increase the surgical corridor, including the method of dural and tentorial opening. The authors describe their method of dural opening and tentorial resection, and detail the microanatomy related to their technique to clarify pitfalls and effects.

METHODS

The relationship of temporal bridging veins and cranial nerves (CNs) around the tentorial resection area was examined during the combined petrosal approach in 20 cadaveric specimens. The authors also reviewed their 23 consecutive clinical cases treated using this technique between 2002 and 2010, focusing on the effects and risks of the procedure.

RESULTS

In the authors' method, the tentorial resection extends from 5 to 10 mm anterior to the junction of the sigmoid sinus and the superior petrosal sinus ("sinodural point") to the trigeminal fibrous ring and the dural sleeve of CN IV. Temporal bridging veins enter the transverse sinus no more than 5 mm anterior to the sinodural point. The CN IV should be freed from its tentorial dural sleeve while avoiding disruption of the posterior cavernous sinus. The clinical data demonstrate a total resection rate of 78.3%, intraoperative estimated blood loss < 400 ml at a rate of 80.9%, and a venous congestion rate of 0%.

CONCLUSIONS

Understanding the anatomical relationship between the tentorium and temporal bridging veins and CNs IV-VI allows neurosurgeons the ability to develop a combined petrosal approach to PCMs that will effectively supply a wide operative corridor after resecting the tentorium, while significantly devascularizing tumors.

Preoperative onyx embolization of meningiomas fed by the ophthalmic artery: a case series

Embolization of head and neck hypervascular tumors is a well-established therapeutic technique. Preoperative embolization reduces intraoperative blood loss, shortens the length of surgery, and decreases surgical morbility and mortality. This study assesses the safety and efficacy of preoperative embolization of meningiomas fed by the OPH by using Onyx liquid embolic agent.

Embolization of Skull Base Meningiomas and Feeding Vessels Arising From the Internal Carotid Circulation

BACKGROUND:

Practice patterns regarding the preoperative embolization of skull base tumors vary widely among institutions and are driven by surgeon preference and concerns about safety.

OBJECTIVE:

We present a recent experience at our institution with a specific focus on procedural decision-making, embolization of vessels arising from the internal carotid circulation, and complication rates.

METHODS:

During a 7.5-year period, 262 meningiomas were referred for embolization. of which 119 (45%) originated from the skull base. Tumors were categorized by location, feeding artery origin, and arteries embolized. Complication rates were reviewed.

RESULTS:

Sixty-four of 119 patients with skull base tumors (54%) underwent embolization of at least 1 feeding artery. Feeding arteries arose from the external carotid artery (ECA) circulation in 26 (22%), the internal carotid artery (ICA) circulation in 30 (25%), a combination of ECA/ICA/Vert in 54 (45%), and had only pial supply in 10 (8%). In total, 15 of 85 (18%) ICA feeding vessels were embolized. This included 9 of 28 vessels from the meningohypopheseal trunk, 3 of 4 vessels from the anterior temporal artery, 1 of 35 vessels from the ophthalmic artery, 1 of 8 vessels directly from the ICA, and 1 of 5 vessels from the inferolateral trunk. Complete devascularization occurred in 6 of 64 patients; subtotal devascularization was seen in 58 of 64. The overall angiographic complication rate for all meningiomas embolized in the study period was 2.5% (5/199). None of the complications occurred in the skull base group.

CONCLUSION:

Preoperative embolization of skull base meningiomas and ICA feeding vessels can be done with low complication rates when intraprocedural decision-making favors complication avoidance over complete devascularization.

Clinical management of petroclival meningiomas and the eternal quest for preservation of quality of life: personal experiences over a period of 20 years

BACKGROUND

Within the realm of neurosurgery, petroclival meningiomas are regarded as probably the most difficult tumour to be treated by microsurgery. This is due to the not infrequently large size of the tumours which, although predominantly located in the posterior fossa, may occupy more than one cranial compartment, with often significant space-occupying effect and brain stem compression. Frequent tight brain stem adherence as well as encasement of the basilar artery, its perforators and cranial nerves adds to the sometimes extreme difficulties of surgical tumour removal. Counselling patients as well as pre- and intraoperative decision making in petroclival meningiomas is even more difficult because upon clinical and radiological tumour detection, despite sometimes surprisingly large tumours, clinical symptoms are often only mild. Summarising the complicated development of petroclival meningioma surgery over the last 60 years, this paper represents the conceptual thinking of the author in regard to the treatment of petroclival meningiomas which has evolved over more than two decades, based on a special interest in these treacherous tumours, and accumulated experiences in the treatment of over 150 patients. Surgical concepts and the operative decision-making process are demonstrated in four illustrative cases.

METHODS

Over a period of slightly over 20 years, between January 1988 and December 2008, 161 patients with petroclival meningiomas were managed clinically by the author or under his direct surveillance in four academic neurosurgical institutions. The observation period ranged from 4 to 242 months. Thirteen patients were lost to follow-up so, all together, complete data were available for 148 patients. In 119 patients (80%), the tumour was large. Giant tumours accounted for 7% and 11 patients, medium-sized tumours were found in 12 patients (8%) and small tumours in only six patients (4%). Sixty-two percent of the patients had invasion of Meckel's cave or some part of the cavernous sinus, mainly the posterior region to different degrees. All giant tumours and one third of the large tumours extended into more than one cranial fossa.

RESULTS

The treatment modalities in the 148 patients were as follows: microsurgery alone was performed in 71 patients (48%), microsurgery and adjuvant radiosurgery in 22 patients (15%) so in 93 patients (63%), altogether, microsurgery was the primary treatment. Twenty-nine patients (20%) underwent radiosurgery as their only treatment, and two patients (1%), during the very early phase of the study period, received radiotherapy. Twenty-four patients (16%) were only observed without any additional therapy. Gross total resection was achieved in 34 patients (37%), and subtotal resection, defined as removal of more than 90% of the tumour volume, was performed in another 36 patients (39%). Radical tumour removal was possible in 76% of the patients. There was no procedure-related death within 3 months post-surgery; the early post-op surgical complication rate was 31% with new neurological deficits or worsening of pre-existing deficits. During the observation period, almost all patients recovered significantly bringing the percentage of permanent neurological deficits, again mainly cranial nerve deficits, down to 22%.

CONCLUSIONS

Based on the experiences of the author, the following treatment principles in petroclival meningiomas are proposed: small tumours in asymptomatic patients should be observed. If tumour growth is detected on serial magnetic resonance imaging or treatment is desired by the patient, surgery should be the first choice. Radiosurgery in growing small tumours should be reserved to patients with advanced age or significant co-morbidities. In medium-sized tumours and symptomatic patients, radical surgery should be attempted, if possible by judicious intraoperative judgement. In large and giant petroclival meningiomas, tumour resection as radical as possible judged intraoperatively with decompression of neural structures should be performed, followed by observation and, in the case of growing tumour remnants, radiosurgery. Thus, by a combined application of advanced microsurgical techniques, thoughtful, intraoperative decision making with limited surgical aggressively and, in selected patients, with small tumours or small tumour remnants simple observation or alternative or adjunct radiosurgery, excellent results as measured by tumour control and preservation of quality of life can be achieved.

Treatment of pseudoaneurysm of internal maxillary artery: a case report

Pseudoaneurysms are rare lesions secondary to blunt or penetrating trauma, temporomandibular joint surgery, or orthognathic surgery. Nonsurgical interventions are the treatment of choice for pseudoaneurysms. In the case reported here, endovascular injection of acrylic glue was successful in the treatment of a pseudoaneurysm of the internal maxillary artery secondary to fracture of the zygomatic bone.

Balloon-assisted embolization of skull base meningioma with liquid embolic agent

The authors report a novel technique of balloon-assisted embolization of a skull base meningioma supplied by a branch of the cavernous segment of the internal carotid artery using liquid embolic agent. A temporarily inflated balloon distal to the meningioma's feeding vessel may improve the access to this small branch and may reduce the chances of unintended reflux during delivery of the liquid embolic agent.

[Transfusion in neurosurgery]

In neurosurgery, the question of the optimal transfusion "trigger" remains a controversial matter. Regarding the brain, the current data are still incomplete, justifying the continuation of experimental and clinical studies. The existing expert advices are based on these rather poor data and would probably evolve after the completion of clinical studies in progress. In spine surgery, the situation is simpler and the transfusional stakes are quite similar to those of orthopedics and traumatology. With regard to hemostasis, standardized recommendations exist depending on the laboratory test results or the anticoagulant treatments of the patient.

Single-stage operation for a giant haemangiopericytoma following intracranial feeder embolization

Meningeal haemangiopericytomas (HPC) are malignant intracranial neoplasms that commonly recur and metastasize. Large size at diagnosis, abundant intracranial feeders and the risk of intraoperative bleeding can make them difficult to completely remove in one operation. We report here a rare case of a giant HPC which was treated successfully using a one-stage operation following superselective intracranial feeder occlusion. A 30-year-old man presented with a left middle cranial fossa tumour extending to the left temporal lobe and cerebellar tentorium. Angiography revealed supply from a dilated left posterior temporal artery branching from the posterior cerebral artery. The tumour was totally removed in a single-stage excision after embolization of the intracranial major feeding artery. The present case suggests the usefulness of preoperative embolization for HPC, particularly of intracranial feeders, to achieve total resection safely in a single operation.

Embolization in the External Carotid Artery

The technical skill set of peripheral interventional radiologists is well-suited to the performance of most transcatheter embolization procedures in the external carotid artery (ECA). These procedures center in large part on hypervascular tumors, epistaxis, and trauma. ECA embolization in the trauma patient is well-defined, albeit in small patient series. The transcatheter treatment of epistaxis is still mostly reserved for cases that are intractable to conservative therapy. Preoperative embolotherapy for vascular tumors remains popular, although it is somewhat controversial in terms of its risk-benefit ratio. The purpose of this review is to highlight pertinent anatomy, selected technical procedural aspects, and the available literature to better characterize the role of ECA embolization in the hands of the practicing peripheral interventionist.

Preoperative embolization of brain tumor with pial artery or dural branch of internal carotid artery as feeding artery

SUMMARY

This study evaluated the clinical usefulness of preoperative embolization of the pial artery or dural branch of the internal carotid artery (ICA) for brain tumor. Subjects comprised 17 patients with large hypervascular brain tumors who underwent preoperative selective embolization. Micro-catheters (2- or 1.7-F) and shapeable hydrophilic micro-guide wires were used for pial artery (branching from the posterior or anterior cerebral artery) or ICA dural branch embolization. Embolization was performed under digital subtraction fluoroscopy with Polyvinyl alcohol (PVA) particles (150-250 mm) and/or liquid coil.Tumor resection was performed immediately or the day after embolization. Digital subtraction angiography (DSA) before and after endovascular devascularization, blood loss during tumor resection, and clinical outcome were evaluated. All endovascular procedures were technically successful. Post-embolization DSA revealed either a disappearance or a marked decrease of the tumor stain in all cases. Control of intraoperative bleeding was easily accomplished, and intraoperative blood loss was low. Preoperative particle embolization of the feeding artery from the cortical artery or ICA dural branch is safe and effective as adjuvant therapy before tumor resection.