Fluorescein videoangiography (FL-VAG) as a predictor of cerebral bypass patency

Background

The fluorescein videoangiography (FL-VAG) has become a valuable adjunct tool in vascular neurosurgery. This work describes using the FL-VAG during bypass surgery and proposes a classification method for evaluating surgical results.

Methods

We analyzed 26 patients with 50 cerebral bypasses from September 2018 to September 2022. We used a three grades classification method based on the pass of intravenous fluorescein through the anastomosis. Grade 1 represents the synchronous and total filling of the "T" shape ("green T″) formed by the donor and recipient vessel, Grade 2, the asynchronous filling of the anastomosis (incomplete/asynchronous "green T″), and Grade 3, a non-patent anastomosis (absence of "green T″).

Results

Of the 26 patients, 8 underwent one bypass, 14 underwent double bypass, 2 underwent three bypasses, and 2 underwent four bypasses in two different interventions. The type of bypass was end-to-side anastomosis in 47 (94%) cases, internal maxillary artery to middle cerebral artery bypass with a radial artery graft (IMax-MCA anastomosis) in 2 (4%), and PICA-VA transposition in one (2%). We made 24 (48%) bypasses on the right side and 26 (52%) on the left side. After the initial surgery, thirty-nine (78%) bypasses were considered as Grade 1, 5 (10%) as Grade 2, and 6 (12%) as Grade 3. After intraoperative bypass patency assessment (IBPA), 45 (90%) of the bypasses were considered Grade 1 and remained patent on CTA.

Conclusions

Using FL-VAG and a three-tier classification method is a reliable tool to predict bypass patency. It is safe, low-risk, and available worldwide.

Prototype of Low-Cost Microvascular Clips for Laboratory Use

BACKGROUND

Vascular neurosurgical procedures require temporary or permanent surgical clips to treat cerebral aneurysms, arteriovenous malformations, or bypass surgery. In this scenario, surgical clips should have specific characteristics such as high-quality material, proper design, closing force, and biocompatibility. Due to these characteristics, the price of these clips does not allow their availability at the experimental surgery laboratory worldwide.

METHODS

We describe here the technique for manufacturing handcrafted clips of low cost, using dental stainless steel or titanium wire of 0.18 mm, 0.20 mm, or 0.22 mm in diameter. We must complete six steps to obtain the clip using our hands and small electrician needle nose pliers for wire molding.

RESULTS

These clips have a closing force of 30-60 gr/cm2 (depending on the wire diameter). They can be used in the experimental surgery laboratory to clip arteries or veins during vascular microsurgery procedures. Also, they can be used as temporary clips with confidence in low-flow bypass (v.gr. superficial temporal artery to middle cerebral artery or occipital artery to posterior inferior cerebellar artery anastomoses).

CONCLUSIONS

Making practical low-cost clips for use in laboratory procedures or during low-flow anastomosis as temporary clips is possible. The main advantages are the low cost and the worldwide availability of the basic materials. The main disadvantage is the learning curve to get the ability to master the manufacturing of these clips.

Bone anatomic variations of the parasellar region and its technical implications in para clinoid and posterior communicating segment aneurysms microsurgical clipping - Technical note

Background

Microsurgical treatment of paraclinoid aneurysms is a complex task that generally requires anterior clinoid process (ACP) removal to obtain adequate surgical exposure. This procedure poses a considerable technical difficulty due to the association of the ACP to critical neurovascular structures. Furthermore, anatomical variations in the parasellar region, such as the caroticoclinoid foramen (CCF) or an interclinoid bridge (ICB), may impose additional challenges and increase surgical complications. The present study aims to briefly review some anatomic variations in the parasellar region and describe a step-by-step surgical technique for a hybrid anterior clinoidectomy based on the senior author's experience.

Methods

We present two cases with bone variations on the parasellar region in patients with a paraclinoid aneurysm and another with a posterior communicating segment aneurysm treated by microsurgical clipping at our hospital.

Results

We focused on safely dealing with these variations during surgery, without further complications, and with good postoperative results. Patients were discharged with no significant deficit. Postoperative control, computed tomography angiography showed complete exclusion of aneurysms.

Conclusion

Although anatomical variations in the parasellar region can complicate surgical clipping of these aneurysms, it is essential to ensure the best possible surgical outcome to conduct thorough preoperative and radiological evaluations.

Internal maxillary artery (IMax) - middle cerebral artery bypass in a patient with bilateral atherosclerotic carotid occlusion: A technical case report

Since the first description of the possible utilization of the internal maxillary artery for bypass surgery, there are some reports of its use in aneurysm cases; however, there is no information about the possible advantages of this type of bypass for cerebral ischemic disease. We present a 77-year-old man with a history of diabetes, hypertension, systemic atherosclerosis, and two acute myocardial infarctions with left hemiparesis. Imaging studies reported total occlusion of the right internal carotid artery and 75% occlusion on the left side, with an old opercular infarction and repeated transient ischemic attacks in the right middle cerebral artery territory despite medical treatment. After a consensus, we decided to perform a bypass from the internal maxillary artery to the M2 segment of the middle cerebral artery using a radial artery graft. After performing the proximal anastomosis, the calculated graft's free flow was 216 ml/min. Subsequently, after completing the bypass, the patency was confirmed with fluorescein videoangiography and intraoperative Doppler. Postoperatively, imaging studies showed improvement in the perfusion values and the hemiparesis from 3/5 to 4+/5. The patient was discharged one week after the operation, with a modified Rankin scale of 1, without added deficits. The use of revascularization techniques in steno-occlusive disease indicates a select group of patients that may benefit from this procedure. In addition, internal maxillary artery bypass has provided a safe option for large areas of ischemia that cannot be supplied with a superficial temporal artery - middle cerebral artery bypass.

Paraclinoid aneurysms clipping through an extradural sphenoid ridge keyhole approach

BACKGROUND

Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical clipping.

METHOD

A description of the surgical technique was made by the senior author, a vascular neurosurgeon experienced with the use of this approach in the management of paraclinoid aneurysms exemplified through a clinical case.

CONCLUSION

Microsurgical clipping through an extradural sphenoid ridge keyhole approach for small and midsize paraclinoid aneurysms is an excellent treatment modality with good clinical and surgical results.

Limitation of fenestrated clips during clipping of middle cerebral artery aneurysm: Technical note

Background

The middle cerebral artery (MCA) is a common site of cerebral aneurysms and 82.6% occur at the bifurcation. When surgery is selected as a therapeutic option, it intends to clip the neck completely because if some remnant occurs, there exists the possibility of regrowth and bleeding in the short- or long-term.

Methods

We analyzed one drawback of the fenestrated clips of Yasargil and Sugita types to occlude the neck totally at a specific point formed by the union of the fenestra with the blades, creating a triangular space where the aneurysm can protrude, giving place to a remnant that can lead to a future recurrence and rebleeding. We show two cases of ruptured MCA aneurysms in which a cross-clipping technique occluded a broad base and dysmorphic aneurysm using straight fenestrated clips.

Results

In both cases (one using a Yasargil clip and the other with a Sugita clip), a small remnant was visualized when fluorescein videoangiography (FL-VAG) was used. In both cases, the small remnant was clipped with a 3 mm straight miniclip.

Conclusion

We should be aware of this drawback when clipping aneurysms using fenestrated clips to ensure a complete obliteration of the aneurysm's neck.

Lhermitte-Duclos disease: A rare case of cerebellar tumor with successful surgical treatment

Background

Lhermitte-Duclos disease (LDD) or dysplastic gangliocytoma of the posterior fossa is a slow-growing and extremely rare mass lesion that involves the Purkinje neurons and the granular layer of the cerebellum. It is characterized by specific neuroradiological features and secondary hydrocephalus. However, documentation of surgical experience is scarce.

Case Description

A 54-year-old man with LDD manifesting as progressive headache is presented with vertigo and cerebellar ataxia. Magnetic resonance imaging demonstrated a right cerebellar mass lesion with the characteristic "tiger-striped appearance." We decided to perform partial resection with reduction of tumor volume improving symptomatology as a result of the mass effect in the posterior fossa.

Conclusion

Surgical resection is a good alternative for the management of LDD, especially when neurological compromise exists due to mass effect.

Microsurgical treatment of carotid body tumors using periadventitial dissection: Analysis of outcomes and prognostic factors in a neurological referral center

Background:

Surgical resection for carotid body tumors (CBTs) is the gold standard of treatment and continues to be a challenging procedure, commonly associated with high vascular injury rates and neurological complications.

Methods:

It is a retrospective case series study between January 2002 and November 2020, with a mean follow-up of 29 months in a single nationwide referral center. Thirty-one patients diagnosed with a carotid body tumor and treated with microsurgical periadventitial resection were included in the study. Patients’ demographics, comorbidities, clinical, radiological factors, and tumor grade, evaluated by the Shamblin scale, were obtained. Statistical analysis was performed on all collected data.

Results:

In this study, we included 31 patients (32 tumors), 80% of the patients were female, and 20% were male, with a mean age of 53 years. One patient presented with bilateral lesions, while 17 tumors were located on the left side. The most frequent symptom was a painless, slow-growing neck mass in 74% of patients. Using the Shamblin classification, 13% of tumors were Grade I, 53% Grade II, and 34% Grade III. In the postoperative period, 3% of patients presented with permanent cranial nerve deficit, while none had vascular injuries or postoperative stroke. A tumor >5 cm increased the risk for nerve lesion by 11 times (OR 12.6, CI 95% 7.4-11.4, P < 0.001).

Conclusion:

Preoperative embolization followed by periadventitial resection by means of a microsurgical technique is a safe and effective approach to remove CBT, with 3% cranial nerve injury rate and no need for vascular sacrifice or reconstruction.

Ruptured aneurysm associated with a twig-like middle cerebral artery: An illustrative case report

Background:

Anomalies of the middle cerebral artery (MCA) are rare; among the different types of anomalies, the aplastic or twig-like (Ap/T) MCA is extremely rare and has been reported under various names, including aplastic, unfused, or rete type anomaly. The occurrence of a brain aneurysm associated with this anatomic variant is an even rare event, and probably their development and rupture are related to hemodynamic stress of the tinny wall of vessels forming the network.

Case Description:

We present a 43-year-old male patient with an explosive and persistent right orbitofrontal headache. A computed tomography showed a right frontobasal hematoma with intraventricular disruption. Magnetic resonance angiography showed a right MCA aneurysm and what seems to be a MCA trunk stenosis. Cerebral digital subtraction angiography demonstrated a plexiform arterial network and one aneurysm arising from the network. The patient was successfully treated by surgical clipping to evacuate the hematoma and to prevent further intracranial hemorrhages.

Conclusion:

The Ap/T-MCA may be associated with hemodynamic stress with a significant effect through the tinny wall of the vessels causing hemorrhage or leading to the formation and rupture of cerebral aneurysms. Based on a correct diagnosis of the anomaly, treatment can be completed successfully through different standard methods.

Operative considerations and surgical treatment of sylvian fissure arteriovenous malformations: a 20-year experience

OBJECTIVE

Sylvian fissure (SF) arteriovenous malformations (AVMs) are among the most challenging vascular lesions amenable to neurosurgical treatment and account for 10% of all locations. As radiosurgery and endovascular techniques are increasingly involved in multimodal management protocols, the role of microsurgery needs to be reassessed as a stand-alone technique. The aim of this study was to show that total excision can be achieved with reasonable levels of morbidity and mortality in a real-world setting from a specialized high-volume center.

METHODS

Forty-three patients with SF AVMs were identified from a series of 577 AVM patients treated microsurgically over a 22-year period. The mean patient age was 33.07 years (range 15–60 years), and there were 22 male and 21 female patients. The mode of presentation was headache in 51.2%, hemorrhage in 34.9%, seizures in 30.2%, and steal phenomenon in 9.3%. The authors analyzed the anatomical basis and angiographic characteristics of such lesions.

RESULTS

In the preoperative period, 83.7% of the patients had a modified Rankin Scale (mRS) score of 0–2, and 16.3% had an mRS score of 3–5. After a 12-month follow-up, 95.3% of patients had an mRS score of 0–2, and 4.7% had a score of 3–6. The difference between pre- and postoperative scores was not statistically significant. SF AVMs have several particular features: 1) They produce angiographic steal of the anterior cerebral artery. 2) The nidus is fed by only one of the main trunks of the middle cerebral artery (MCA). 3) Participation of deep perforators is uncommon. 4) They have two or more early draining veins showing their fistulous nature. 5) Preoperative embolization and radiosurgery have a low rate of permanent cure.

CONCLUSIONS

These AVMs represent a surgical challenge due to their proximity to critical structures such as the MCA, insula, internal capsule, and speech and memory functions in the dominant hemisphere. Essential key points are the wide opening of the SF and proper differentiation between feeders and normal vessels. Although this location can seem daunting, SF AVMs carry no additional surgical risk if adequately managed.

Neuroprotective effect of dapsone in patients with aneurysmal subarachnoid hemorrhage: a prospective, randomized, double-blind, placebo-controlled clinical trial

OBJECTIVE

In this study, the authors sought to define the differences in the incidence of delayed cerebral ischemia (DCI) between patients treated with dapsone and those treated with placebo. Secondary objectives were to define the clinical outcome at discharge and 3 months and the incidence of brain infarction.

METHODS

A prospective, randomized, double-blind, placebo-controlled study was performed and included patients with aneurysmal subarachnoid hemorrhage (SAH) within 5 days from ictus who were candidates for aneurysm occlusion, and who had a Fisher grade of 3 or 4. Patients with sulfa or sulfone drug allergies, hemoglobin < 11 g/dl, known G6PD deficiency, and those refusing informed consent were excluded. A minimal relevant effect decrease of 35% in the incidence of DCI was established. Patients were randomly assigned to receive a regimen of dapsone 2.5 ml (100 mg) daily or a placebo (aluminum hydroxide suspension, 2.5 ml daily). Both groups received validated treatment for aneurysmal SAH. The appearance of DCI on CT was assessed in every patient at discharge and 3 months later. We used the chi-square test to compare the DCI incidence between both groups, and the Student t-test or nonparametric tests to compare quantitative variables.

RESULTS

Overall, 48 patients (70.8% women and 29.2% men) were included. The mean age was 50 years (SD 14.28 years, range 18-72 years). Prerandomization and postrandomization characteristics were balanced, except for the necessity of intra-arterial nimodipine administration in patients treated with placebo (15.4% vs 45.5%, p = 0.029. The incidence of DCI, the primary endpoint, for the whole cohort was 43.8% and was significantly lower in the dapsone group (26.9% vs 63.6%, p = 0.011). In addition, the irreversible DCI incidence was lower in the dapsone group (11.5% vs 54.5%, p = 0.12). A favorable modified Rankin Scale score was more frequent in the dapsone group at discharge and at 3 months (76.9% vs 36.4%, p = 0.005 and 80% vs 38.9%, p = 0.019, respectively). Also, the brain infarction incidence was lower in the dapsone group (19.2% vs 63.6%, p = 0.001). There was no difference between groups regarding adverse events.

CONCLUSIONS

Dapsone seems to play a role as a prophylactic agent in patients at high risk of developing DCI after aneurysmal SAH. A multicenter investigation is necessary to increase the study population and confirm the consistency of the results observed in this study.

Giant Posterior Inferior Cerebellar Artery Aneurysm Mimicking a Brainstem Tumor

Aneurysms from the vertebrobasilar system are rare, accounting for only 5%-10% of all intracranial aneurysms. The most common sites in which these lesions occur are the bifurcation of the basilar artery and the origin of the posterior inferior cerebellar artery (PICA). When the aneurysms present in the distal portion of the PICA, they represent from 0.5% to 6%. These aneurysms are called giant when they exceed 25 mm in diameter. We present a case of a 49-year-old male who presented with acute obstructive hydrocephalus, which required ventriculoperitoneal shunting and left hemispheric cerebellar syndrome. The magnetic resonance imaging study revealed an occupative mass located in the fourth ventricle, and diagnostic angiography showed a partially thrombosed giant saccular aneurysm in the posterior inferior cerebellar artery. He underwent surgical management via a lateral suboccipital approach. The aneurysm was remodeled and clipped successfully without complications, with an uneventful postoperative course.

Although rare, PICA aneurysms should always be considered when posterior fossa syndrome occurs, including brainstem and cranial nerve compression symptoms. It can easily be misdiagnosed as a neoplastic lesion, especially when the aneurysm reaches big or giant size. Therefore, complete diagnostic studies, such as cerebral angiography, must be performed. Surgical clipping must be offered as the first line of treatment. It provides occlusion of the aneurysm and relieves compressive symptoms.

Subarachnoid Hemorrhage From Rupture of an Undiagnosed Posterior Circulation Aneurysm During Sellar Tumor Surgery

Association between cerebral aneurysms and sellar tumors has been previously reported. Rupture of anterior circulation aneurysms during a transsphenoidal surgery causing massive subarachnoid hemorrhage (SAH) is uncommon, but rupture of a posterior circulation aneurysm is an infrequent event.

We present three cases of SAH secondary to rupture of an undetected posterior circulation aneurysm during transsphenoidal surgery to treat a sellar tumor. The common factor in these cases was the adverse outcome despite treatment. 

The fatal outcome seen in all these cases questions whether to include a (magnetic resonance) MR angiography or (computed tomography) CT angiography during preoperative evaluation for sellar tumors in order to identify inadvertently associated aneurysms.

Hypothalamic Cavernous Malformation: Surgical Technique and Literature Review

Hypothalamic cavernous malformation (HCM) is rare, and to our knowledge, there are only 28 cases reported in the literature.

An 18-year-old male presented two years ago with a severe headache followed by right eye blindness. Following imaging studies, a bleeding hypothalamic cavernoma was discovered together with another incidental cavernoma in the brain. We sustained the diagnosis of cavernomatosis, and conservative treatment was indicated. A year later, he presented severe headache and vomit; for this reason, the patient underwent a new MRI which showed a new bleeding episode of the HCM lesion. We carried out an endocrinological assessment, and microsurgical resection was recommended. Although visual impairment persisted as expected in the postoperative period, he showed good clinical recovery overall.

Hypothalamic location of a cavernous malformation is infrequent, accounting for only 1% or less of these lesions, and are known to cause a variety of symptoms inducing headache, visual disturbance, and less frequently, hypothalamus dysfunction. Surgical intervention can be considered after a second symptomatic bleed, always assessing the risk of non-favorable postsurgical outcomes against the intrinsic risk that these malformations imply.

Case reports like this are essential to reach a consensus towards the best treatment option for HCM.

Spontaneous regression of a thrombosed cerebral arteriovenous malformation in a patient with a prothrombotic state associated with multiple myeloma: A case report and literature review

Background

Cerebral arteriovenous malformations (AVMs) are pathologic communications between veins and arteries of the brain vasculature. Its spontaneous regression is rare, and many factors have been described in the effort to explain this phenomenon, including a hypercoagulable state.

Case Description

We present the case of a spontaneous unruptured AVM regression in a patient where thrombosis of the malformation was found, probably due to a prothrombotic state associated with multiple myeloma (MM).

Conclusion

We aim to contribute to the study of this rare phenomenon, presenting the relationship between a hypercoagulable state caused by MM and the spontaneous AVM regression that has not been previously reported.

Moyamoya disease in Mexico: our experience

INTRODUCTION

Moyamoya disease (MD) is a progressive, occlusive disease of the arteries of the anterior cerebral circulation that may cause ischaemia or haemorrhage. Patient management aims to prevent new cerebrovascular events through surgical revascularisation and/or pharmacological treatment.

MATERIALS AND METHODS

We studied a series of 17 patients with MD (n = 14) or moyamoya syndrome (MS; n = 3), who were evaluated between January 1989 and December 2016; 11 patients were women and 6 were men. Thirteen patients had definitive MD (76%), one had unilateral MD (5.2%), and 3 had MS (18%). The condition manifested as intraparenchymal haemorrhage (in 35.2% of patients), brain ischaemia (29.4%), subarachnoid haemorrhage (17.6%), seizures (11.7%), and headache with no associated haemorrhage (1 patient).

RESULTS

Ten patients (58.8%) underwent revascularisation and 7 (41.2%) received pharmacological treatment. All patients were evaluated with the modified Rankin Scale (mRs) at admission and at the last consultation; mRs scores were significantly lower in the group undergoing surgery (P <  .04). During follow-up, none of the patients undergoing revascularisation experienced recurrences, whereas 2 patients receiving pharmacological treatment did experience a new vascular event (one ischaemic and one haemorrhagic) (P <  .05). No significant differences were observed between the treatment outcomes of different revascularisation techniques.

CONCLUSIONS

Although our population has different demographic characteristics from those of other non-Asian populations, ours is the largest published series of Hispanic individuals with MD. Our results support the use of revascularisation procedures to improve these patients' neurological status and to prevent new cerebrovascular events.

Moyamoya disease in Mexico: Our experience

INTRODUCTION

Moyamoya disease (MD) is a progressive, occlusive disease of the arteries of the anterior cerebral circulation that may cause ischaemia or haemorrhage. Patient management aims to prevent new cerebrovascular events through surgical revascularisation and/or pharmacological treatment.

METHODS

We studied a series of 17 patients with MD (n = 14) or moyamoya syndrome (n = 3), who were evaluated between January 1989 and December 2016; 11 patients were women and 6 were men. Thirteen patients had definitive MD (76%), one had unilateral MD (5.2%), and 3 had moyamoya syndrome (18%). The condition manifested as intraparenchymal haemorrhage (in 35.2% of patients), brain ischaemia (29.4%), subarachnoid haemorrhage (17.6%), seizures (11.7%), and headache with no associated haemorrhage (one patient).

RESULTS

Ten patients (58.8%) underwent revascularisation and 7 (41.2%) received pharmacological treatment. All patients were evaluated with the modified Rankin Scale (mRs) at admission and at the last consultation; mRs scores were significantly lower in the group undergoing surgery (P < .04). During follow-up, none of the patients undergoing revascularisation experienced recurrences, whereas 2 patients receiving pharmacological treatment did experience a new vascular event (one ischaemic and one haemorrhagic) (P < .05). No significant differences were observed between the treatment outcomes of different revascularisation techniques.

CONCLUSIONS

Although our population has different demographic characteristics from those of other non-Asian populations, ours is the largest published series of Hispanic individuals with MD. Our results support the use of revascularisation procedures to improve these patients' neurological status and to prevent new cerebrovascular events.

Rebleeding and Outcome in Patients with Symptomatic Brain Stem Cavernomas

Purpose: We sought to evaluate the long-term functional outcomes and identify the potential risk factors for rebleeding in patients with brain stem cavernous malformations (BCMs) who presented with hemorrhages and were surgically or conservatively treated and prospectively monitored. Methods: From January 1990 to July 2015, we included patients with first hemorrhagic episodes secondary to single BCMs. Modified Rankin score (mRS) was used for neurological status assessment. Univariate and multivariate regression statistics were used to identify the risk factors for rebleeding. Results: A total of 99 patients with BCMs hemorrhages were included (59 [59.6%] women, mean age 37± 13 years). As initial treatments, 37 patients (37.4%) underwent surgery and 62 (62.6%) received conservative treatment. The median follow-up was 3.33 years (interquartile range 1.16-7 years; 408.3 patient/years). The rebleeding rate by patient/year was 10% in conservatively treated patients. Deterioration was significantly more frequent in patients with rebleeding (p = 0.0001). At the end of the follow-up, the mRS were favorable in 49 patients (65.3%) without rebleeding, whereas only 8 (33.3%) with rebleeding evolved to favorable outcomes (p = 0.006). Lesion size >18 mm (hazards ratio, HR 3.34, 95% CI 1.54-7.26; p = 0.0001) and ventral location or crossing the brain stem's midpoint (HR 2.5, 95% CI 1.14-5.46; p = 0.022) were associated with a major risk of rebleeding in the univariate analysis, but only a lesion >18 mm remained statistically significant (HR 2.7, 95% CI 1.2-6.21; p = 0.016) in the multivariate analysis. Conclusion: A lesion size >18 mm was the principal factor associated with hemorrhage recurrence. The overall functional outcome was good. However, significant morbidity was attributable to rebleeding.

Abstract WMP117: Conservative versus Surgical Treatment for Brainstem Cavernous Malformation

Brainstem cavernous malformation (BCM) account for 8-22% of all intracranial cavernomas. Currently, they can be treated microsurgically or conservative but it is still difficult to choose the best treatment for each patient. The main objective of our series was to evaluate the long-term functional outcome and recurrence in patients with BCM treated with conservative or surgical treatments.

Hypothesis: We assessed the hypothesis that surgical and conservative treatments are associated with different functional outcome and re-hemorrhage rate in long-term follow-up.

Methods: In this non-randomized, clinical series, we compared the clinical and radiological findings of patients with their first hemorrhage secondary to confirmed BCM, treated in a tertiary neurological center, during a twenty five- year period. Treatment of each patient was selected by the attending physician and consisted of either conservative or surgical evacuation of BCM. The primary end-points were recurrent hemorrhage and functional outcome. Favorable prognosis was defined as modified Rankin scale (mRs) of 0 to 2.

Results: From January of 1990 to July of 2015; 99 patients with BCM hemorrhage were treated (59 [59,6%] female; mean age 37± 13 years). 37 patients (37,4%) were surgically treated and 62 (62,6%) received conservative treatment. During the follow-up; 20 patients in the medical group (median time of recurrence: 34,5 months; IQR: 13,75-93) and 4 patients in the surgical group (median time of recurrence: 22 months; IQR: 9-46,5) had a recurrence (OR: 0,255; 95% IC: 0,079-0,817), with a cumulative incidence of 5,1 per 100 years-person and 3,96 per 100 years-person respectively. Because of rebleeding, 11 patients of the conservative group were taken to surgery and 3 of the surgical group were to required re-intervention. At the end of follow-up (median: 51 months; IQR: 19-104) 51 patients remained in the conservative group and 28 (54,9%) had a favorable mRs. 48 patients remained in the surgical group and 27 (56,2%) had a favorable mRs (OR:0,94 95% IC: 0,42-2,09).

Conclusion: Despite a significant high recurrent hemorrhage rate was observed in conservative treated patients, we did not found difference in clinical outcome between both groups of patients with BCM.

Use of the sole stenting technique for the management of aneurysms in the posterior circulation in a prospective series of 20 patients

Object

The use of intracranial stents in stent-assisted coil embolization is now a current neurosurgical practice worldwide. The clinical utility of these stents in the sole stenting (SS) technique, however, has not been thoroughly described, and the published reports of this experience are scarce. This study was designed to evaluate SS treatment of dissecting and nondissecting aneurysms of the posterior circulation.

Methods

This prospective and descriptive study was conducted in 20 consecutive patients who harbored single aneurysms of the posterior circulation and who were treated using the SS approach in the last 3 years. The clinical and radiological assessment and follow-up of the patients were evaluated using the modified Rankin scale as well as with computed tomography angiography and digital subtraction angiography at discharge and at 1, 3, 6, and 12 months.

Results

Eleven of the 20 patients had subarachnoid hemorrhages, 3 presented with ischemia, 1 presented with brainstem compression, and the remaining 5 patients had incidentally discovered, asymptomatic lesions. Only 1 patient had a complication (occipital infarction) attributable to the SS procedure. One patient died of rebleeding 2 weeks after the procedure. At 1 month, 40% of the patients had a subtotal or total occlusion, which increased to 55% at 3 months and 85% at 6 months, with a final subtotal or total occlusion rate of 80% at 1 year. The SS procedure in 1 case was considered a failure at 6 months because no change had been noted since the 1-month follow-up. One case showed partial occlusion and 1 case showed recanalization.

Conclusions

Use of SS for aneurysms in the posterior circulation complex is a safe and effective technique, demonstrating an occlusion rate of 80% at the 1-year follow up.

Arachnoid knife from a hypodermic needle Technical note

BACKGROUND

The arachnoid knife is a useful instrument when performing a variety of neurosurgical procedures, for example, while opening the sylvian fissure or basal arachnoid bridges in the pterional approach or during the peripheral delimitation and excision of a cortical AVM. At present, there exists a wide variety of arachnoid knives made from different materials (stainless steel, titanium, or diamond-tipped); however, most of these instruments are expensive and may become dull with continuous use or bad handling.

METHODS

In this article, we report the use and advantages of an arachnoid knife from a simple hypodermic needle.

RESULTS

In the last 6 years, we have used this technique to open the arachnoid layer in more than 350 neurosurgical procedures. Furthermore, it can be used to perform sharp arteriotomies during bypass procedures or to open the dura mater over bone structures. To date, no complication arising from this simple technique has been documented.

CONCLUSIONS

A standard hypodermic needle can be used in the operating room as a practical arachnoid knife. It has the characteristics of being effective, low-cost, and available worldwide.

Anatomic and surgical basis of the sphenoid ridge keyhole approach for cerebral aneurysms

In vascular neurosurgery, the pterional approach has been used primarily for the treatment of a wide variety of diseases (cavernous angiomas, arteriovenous malformations, etc.), and it is used to take advantage of naturally occurring planes and spaces to expose the major structures of the circle of Willis. It provides access to the major part of the anterior circulation aneurysms and those occurring in the upper and most proximal part of the posterior circulation. Conversely, there has been an increasing interest in the so-called minimally invasive procedures or keyhole approaches to treating cerebral aneurysms in specific locations. In this work, we describe a novel keyhole approach that was conceived to achieve the angle of vision and advantages of the classic pterional approach. This surgical approach is based on the anatomic location of the sphenoid ridge and its relationship with the sylvian fissure and basal cisterns. The initial incision is made over the hairline behind the external border of the eye on the side selected. A skin and muscular flap is reflected anteriorly, and a small 3 x 3-cm craniotomy is completed around the external landmarks of the sphenoid ridge. Further extradural drilling is completed down to the anterior clinoid process. The dura is opened in a semilunar manner, and the sylvian fissure is opened completely to reach the sylvian and basal cisterns. Thereafter, the aneurysm is dissected and clipped according to the standard microtechnique of the neurosurgeon. A step-by-step description of the approach is offered in this work to facilitate a clear understanding of it. We recommend this approach for treatment of aneurysms arising at the anterior part of the circle of Willis. It has the advantages of less operative time, fewer days of hospitalization, and similar morbidity and mortality compared with the standard pterional craniotomy (5.7% on our service for nongiant ruptured aneurysms).

Trigeminal neuralgia secondary to arteriovenous malformations of the posterior fossa

BACKGROUND

Trigeminal neuralgia secondary to a posterior fossa AVM has been seldom reported in the literature. Most of the cases have been published on a case report basis, and there is not a general agreement about the best way of treatment.

METHODS

In this work, we analyze our experience with 5 cases of TN secondary to a posterior fossa AVM, treated at the Division of Neurosurgery from the National Institute of Neurology and Neurosurgery, "Manuel Velasco Suarez," Mexico City, Mexico, from January 1985 to December 2004.

RESULTS

Trigeminal neuralgia associated with an AVM occurred in 1.3% of 375 brain AVMs and 9.8% of 37 posterior fossa AVMs. All had received drug therapy unsuccessfully, and 2 of them underwent a percutaneous thermocoagulation without solving the neuralgia. In 4 patients, a microvascular decompression was completed with excellent results.

CONCLUSIONS

Even when different ways of treatment have been reported, it seems that percutaneous procedures (glycerol injection, thermocoagulation, or microcompression of the gasserian ganglia) give variable clinical results. The reported experience and our own results support the microvascular decompression of the trigeminal nerve as the best treatment whenever the total excision of the AVM cannot be accomplished.

[NMDA receptor antagonists in focal cerebral ischemia. An experimental model]

Ischemic cerebrovascular disease is an important cause of morbidity and mortality. One common final pathway in neuronal ischemic damage is the uncontrolled influx of calcium into the cell, mediated by voltage dependent channels or activation of the NMDA (N-methyl D-aspartate) receptor. The therapeutic utility of a non-competitive NMDA blocker (MK-801, 2 mg/kg i.p.), to prevent the neuronal ischemic damage in an experimental middle cerebral artery occlusion model has been tested. The drug was administered 10 minutes before (group 3) and one hour after the arterial occlusion (group 4), and the results were compared with a group in which no medicament was utilized (group 2) and a control group (sham operation, group 1). MK-801 reduced significantly the area of infarction in relation to the control group (p < 0.05), mainly if the MK-801 was administered before the occlusion (group 3). These results suggest that MK-801 may be useful for the prevention of the neuronal ischemic damage caused by focal ischemia. However, before recommending its use in humans, all the possible collateral effects must be defined.

External carotid artery fistula due to microcompression of the gasserian ganglion for relief of trigeminal neuralgia. Case report

Vascular complications after percutaneous injection procedures for relief of trigeminal neuralgia are varied, ranging from puncture of arterial or venous structures to carotid-cavernous fistulas. The authors present a patient in whom an external carotid artery fistula occurred after a microcompression procedure for the treatment of a left-sided trigeminal neuralgia. This is believed to be the first case of this complication secondary to a percutaneous injection procedure for relief of facial pain.

The basal interhemispheric approach for acute anterior communicating aneurysms

We reviewed the surgical outcome in 85 patients with ruptured anterior communicating artery (ACoA) aneurysms, who were operated on within 72 hours of onset via a basal interhemispheric (BIH) approach (Group 1, N = 48), or an anterior interhemispheric (AIH) approach (Group 2, N = 37). The age, sex ratio and pre-operative grade (Gr) were similar for both groups. The outcome at the time of discharge was as follows for group 1: excellent or good 88%; fair, 6%; vegetative state, 2% and death 4%. For group 2, it was: excellent or good 78%; fair, 16%; vegetative state, 3%; and death, 3%. A significant correlation between admission grade and outcome was found in both groups. The outcome in group 1 was better than in group 2 for patients with a Glasgow Outcome Scale (GOS) better than fair (p < 0.07). No patient in group 1 had postoperative anosmia, but nine patients in group 2 became anosmic. The total number of complications was also significantly less in group 1. Our overall mortality rate was 4%. In conclusion, the BIH approach was more beneficial for treating acute ACoA aneurysm.

Intraoperative anatomical studies in patients with aneurysms of the anterior communicating artery complex

The intraoperative anatomical findings of the anterior communicating artery (ACoA) complex in 46 patients with anatomical variations were compared to those in an equal number of patients without variations in order to determine the visualization of the elements of the vascular complex. All patients underwent radical surgery for an ACoA aneurysm by one of three different surgical approaches: transsylvian, anterior interhemispheric, or basal interhemispheric. Visualization of the vascular elements was similar in patients with or without anatomical variations. The differences observed were dependent on the surgical approach selected and on the projection of the aneurysm. It was found that, even when the intraoperative anatomical field and the number of vascular elements visualized are different from those obtained in autopsy studies, the vascular microanatomical characteristics can be confirmed with each surgical approach to the extent necessary to ensure safe clipping of aneurysms in patients both with and without anatomical variations.

Ruptured anterior communicating artery aneurysm causing bilateral abducens nerve paralyses--case report

A rare case of bilateral abducens nerve paralyses after rupture of an anterior communicating artery (AcoA) aneurysm occurred in a 56-year-old female after sudden onset of severe headache. Bilateral abducens nerve paralyses were present without additional neuro-ophthalmological signs. Computed tomography revealed subarachnoid hemorrhage (SAH). Angiography showed an AcoA aneurysm (15 mm in diameter, directed antero-inferiorly) that was successfully clipped. Postoperatively, the bilateral abducens nerve paralyses gradually recovered and disappeared 3 months after onset. Bilateral abducens nerve paralyses may occur after SAH due to ruptured AcoA aneurysm, and neurosurgeons should be alert to this possibility.

[Traumatism of the posterior fossa in children]

Reported are 15 cases of children who suffered injuries to their posterior fossa and the subsequent formation of hematomas and their treatment by the physicians in the Neurosurgical Department of the Traumatology Hospital "Magdalena de las Salinas". Of the 15 cases, 11 had epidural hematomas (three of them with supratentorial extensions), one was subdural, two were cerebellar and another of the brainstem. Seven were considered acute, five were subacute and three were chronic. During their admittance to the hospital, five of the patients were in a state of coma, another five were sleepy or confused and the remaining five were conscious. Three of the patients were conservatively treated, two of which had sequelae or were moderately handicapped. Twelve of the patients were surgically intervened suboccipitally, eleven of which successfully recovered and one of which died. A history of brain injury, occipital fracture and signs of posterior fossa lesions lead to suspect the presence of posterior fossa hematoma.