Juri Kivelev

Anatomic risk factors for middle cerebral artery aneurysm rupture: computed tomography angiography study of 1009 consecutive patients.

BACKGROUND In a variety of surgical specialties, simulation-based technologies play an important role in resident training. The Congress of Neurological Surgeons (CNS) established an initiative to enhance neurosurgical training by developing a simulation-based curriculum to complement standard didactic and clinical learning. OBJECTIVE To enhance resident education in the management of traumatic brain injury by the use of simulation-based training. METHODS A course-based neurosurgical simulation curriculum was developed and offered at the 2012 CNS annual meeting. Within this curriculum, a trauma module was developed to teach skills necessary in the management of traumatic brain injury, including the performance of craniotomy for trauma. Didactic and simulator-based instruction were incorporated into the course. Written and practical pre- and posttests, as well as questionnaires, were used to assess the improvement in skill level and to validate the simulator as a teaching tool. RESULTS Fourteen trainees participated in the didactic section of the trauma module. Average performance improved significantly in written scores from pretest (75%) to posttest (87.5%, P < .05). Eight participants completed the trauma craniotomy simulator. Incision planning, burr hole placement (P < .02), and craniotomy size (P < .05) improved significantly. Junior residents (postgraduate years 1-3) demonstrated the most improvement during the course. CONCLUSION The CNS simulation trauma module provides a complementary method for residents to acquire necessary skills in the management of traumatic brain injury. Preliminary data indicate improvement in didactic and hands-on knowledge after training. Additional data are needed to confirm the validity of the simulator.BACKGROUND The middle cerebral artery (MCA) is the most frequent location for unruptured intracranial aneurysms. Controversy remains as to which unruptured MCA aneurysms should be treated prophylactically. OBJECTIVE To identify independent topographical and morphological variables that could predict increased rupture risk of MCA aneurysms. METHODS A retrospective analysis of computed tomography angiography data of 1009 consecutive patients with 1309 MCA aneurysms, referred between 2000 and 2009 to Helsinki University Hospital, was carried out. Morphological and topographical parameters examined for MCA aneurysms comprised aneurysm wall regularity, size, neck width, aspect ratio, bottleneck factor, height-width ratio, location along the MCA, side, distance from the internal carotid artery bifurcation, and dome projection in axial and coronal computed tomography angiography views. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors for rupture. RESULTS Of the 1309 MCA aneurysms, 69% were unruptured and 31% were ruptured. Most unruptured MCA aneurysms were smaller than 7 mm (78%), with a smooth wall (80%) and a height-width ratio of 1 (47%) and were located at the main bifurcation (57%). Ruptured MCA aneurysms, mostly 7 to 14 mm in size (55%), had an irregular wall (78%) and a height-width ratio greater than 1 (72%) and were located at the main bifurcation (77%). Thirty-eight percent of MCA bifurcation aneurysms, 74% of large aneurysms, 64% of aneurysms with an irregular wall, and 49% of aneurysms with a height-width ratio greater than 1 were ruptured. CONCLUSION Location at the main MCA bifurcation, wall irregularity, and less spherical geometry were independently associated with rupture of MCA aneurysms with a correlation with aneurysm size. artery.

Long-term outcome of patients with multiple cerebral cavernous malformations.

OBJECTIVEMultiple cerebral cavernous malformations (MCCMs) typically occur in patients with a family history of these lesions. Literature on MCCMs is scarce, and little is known about their natural history. METHODSOf 264 consecutive patients with cerebral cavernomas treated at the Department of Neurosurgery, Helsinki University Central Hospital, in the past 27 years, 33 patients had MCCMs. Lesions were categorized according to the Zabramski classification scale. Follow-up questionnaires were sent to all patients. Outcome was assessed using the Glasgow Outcome Scale, and amelioration of epilepsy was assessed using the Engel scale. All clinical data were analyzed retrospectively. RESULTSThe mean age of patients at diagnosis was 44 years. Sex presentation was almost equal. Nine percent of all patients had a family history of the disease. Patients presented with epilepsy, acute headache, and focal neurological deficits. MCCMs were incidental findings in 2 patients. Altogether, 416 cavernomas were found: 70% supratentorial and 30% infratentorial. Fifteen patients had symptomatic hemorrhage before admission to our department. Surgery was performed on 18 patients. In most cases, the largest cavernoma was removed. Postoperatively, 1 patient experienced temporary hemiparesis, and another developed permanent motor dysphasia. No mortalities occurred. The mean follow-up time was 7.7 years. Twenty-six patients (79%) were in good condition. Among patients with epilepsy who underwent lesionectomy, 70% had an Engel class I outcome. On follow-up magnetic resonance imaging, 52 de novo cavernomas were found. CONCLUSIONSurgical treatment of patients with MCCMs is safe. An extirpation of the clinically active cavernoma prevents further bleedings and improves outcome of epilepsy.

Outcome after microsurgery in 14 patients with spinal cavernomas and review of the literature.

OBJECT Spinal cavernomas are rare, but can cause significant neurological deficits due to mass effect and extralesional hemorrhage. The authors present their results of microsurgical treatment of 14 consecutive patients with spinal cavernoma, and review the literature. METHODS Of the 376 patients with cavernomas of the CNS treated at Helsinki University Central Hospital (a catchment area close to 2 million inhabitants) between January 1980 and June 2009, 14 (4%) had a spinal cavernoma. The authors reexamined and analyzed the patient files and images retrospectively. Median patient age at presentation was 45 years (range 20–57 years). The female/male ratio was equal. Median duration of symptoms before admission to the department was 12 months (range 0.1–168 months). Patients suffered from sensorimotor paresis, radicular pain, or neurogenic micturition disorders in different combinations or separately. Hemorrhage had occurred in 7 patients (50%) before surgery. In 9 patients (64%) the cavernoma was intramedullary, in 4 (29%) extradural, and in 1 intradural extramedullary. On MR imaging, 6 patients (43%) had a cavernoma in the cervical region, 7 (50%) in the thoracic region, and 1 (7%) in the lumbar region. RESULTS Postoperatively, patients were followed up for a median of 3 years (range 1–10 years). At follow-up, 13 patients (93%) experienced significant improvement in motor ability after surgery, and all patients were able to walk with or without aid. Ten of the 11 patients with pain syndrome (91%) showed significant pain relief without recurrence. Micturition disorder was noted in 6 patients (43%) at follow-up, but in 5 the condition had existed before surgery. No patient improved in bladder function after surgery, and 1 patient developed micturition dysfunction postoperatively. CONCLUSIONS Microsurgical removal of spinal cavernomas alleviates sensorimotor deficits and pain caused by mass effect and hemorrhage. However, bladder dysfunction remains unchanged after surgery.

Cervical intradural extramedullary cavernoma presenting with isolated intramedullary hemorrhage

Among cavernomas of the central nervous system, spinal ones are rare. The true incidence of spinal cavernomas is unclear, but with widespread use of magnetic resonance imaging the number of cases is increasing. Furthermore, cavernomas represent only 5-12% of all vascular anomalies of the spinal cord, with a mere 3% reported to be intradural and intramedullary in location. Cervical spine intradural extramedullary cavernomas are very seldom seen, and only 4 cases have been reported in world literature previously. In this report, a unique case of an intradural extramedullary spinal cavernoma was surgically treated in a patient who presented only with an intramedullary hemorrhage.

Characteristics of cavernomas of the brain and spine

The incidence of cavernomas in the general population ranges from 0.3% to 0.5%. They frequently occur in young adults, usually being detected between the second and fifth decade of life, in both sporadic and familial forms. Patients with inherited cavernomas are typically affected by multiple lesions, whereas sporadic forms mostly present with a single lesion. Three genes responsible for development of cavernomas identified to date include CCM1, CCM2, and CCM3. The natural history of brain cavernomas is relatively benign and up to 21% of patients are asymptomatic. The most frequent manifestations of the disease are seizures, focal neurological deficits, and hemorrhage. We review the current literature data on the characteristics of brain and spinal cavernomas.

Microsurgical treatment of temporal lobe cavernomas

BackgroundCavernomas of the temporal lobe occur in 10–20% of patients with cerebral cavernomas. They frequently cause epileptic seizures, some of which tend to become refractory to medical therapy. Surgical removal of safely achievable symptomatic lesions has been frequently consistent with good long-term outcome. In the present study, a postoperative outcome is assessed.MethodsOf our 360 consecutive patients with cerebral cavernomas, 53 (15%) had a single cavernoma in the temporal lobe. Forty-nine patients were treated surgically and were included in the study. All data were analyzed retrospectively. The cavernomas were allocated into three groups based on the temporal lobe site: medial, anterolateral, and posterolateral. To collect follow-up data, all available patients were interviewed by phone. Seizure outcome was assessed using the Engel classification and general outcome using the Glasgow Outcome Scale (GOS).ResultsPatients’ median age at presentation was 37 (range, 7–64) years, with a female/male ratio of 2.5:1. Epileptic seizures occurred in 40 patients (82%). Median duration of seizures preoperatively was 3 (range, 0.1–23) years. In addition, four patients (10%) had memory disorder. Three patients without history of seizures (6%) complained of headache and two (4%) had memory problems. Three patients (6%) had an incidental cavernoma. Hemorrhage occurred in nine patients (18%) preoperatively. Median postoperative follow-up time was 6 (range, 0.2–26) years. Favorable seizure outcome (Engel class I and II) was registered in 35 patients (90%). Ten patients (25%) who had only a single seizure before surgery were seizure free during postoperative follow-up. Good general outcome (GOS, 4.5) was detected in 46 patients (96%). Two patients (4%) developed a new mild memory deficit after surgery, and in two patients existing memory deficits worsened.ConclusionsMicrosurgical removal of temporal lobe cavernomas is a safe and effective method to improve seizure outcome in patients with medically intractable epilepsy and to prevent deterioration caused by hemorrhage.

Treatment strategies in cavernomas of the brain and spine

The management of brain and spinal cavernomas includes two main options: (i) conservative treatment or (ii) surgical removal. Clinical experience related to cavernoma patients falls into four major categories: the surgical or conservative treatment of incidental or symptomatic cavernomas. In many patients, cavernomas exist as fairly benign lesions, frequently remaining clinically silent for life. This observation argues against the active treatment of all cavernoma patients; rather for the meticulous selection of only those more likely to benefit from surgery. Thus, the most crucial task in successful management of cavernomas is appropriate patient selection. In this review, we present our institutional experience on cavernoma management supplemented with data from the literature.

Long-term visual outcome after microsurgical removal of occipital lobe cavernomas

OBJECT Cavernomas in the occipital lobe are relatively rare. Because of the proximity to the visual cortex and incoming subcortical tracts, microsurgical removal of occipital cavernomas may be associated with a risk of visual field defects. The goal of the study was to analyze long-term outcome after operative treatment of occipital cavernomas with special emphasis on visual outcome. METHODS Of the 390 consecutive patients with cavernomas who were treated at Helsinki University Central Hospital between 1980 and 2011, 19 (5%) had occipital cavernomas. Sixteen patients (4%) were surgically treated and are included in this study. The median age was 39 years (range 3-59 years). Seven patients (56%) suffered from hemorrhage preoperatively, 5 (31%) presented with visual field deficits, 11 (69%) suffered from seizures, and 4 (25%) had multiple cavernomas. Surgery was indicated for progressive neurological deterioration. The median follow-up after surgery was 5.25 years (range 0.5-14 years). RESULTS All patients underwent thorough neuroophthalmological assessment to determine visual outcome after surgery. Visual fields were classified as normal, mild homonymous visual field loss (not disturbing the patient, driving allowed), moderate homonymous visual field loss (disturbing the patient, driving prohibited), and severe visual field loss (total homonymous hemianopia or total homonymous quadrantanopia). At the last follow-up, 4 patients (25%) had normal visual fields, 6 (38%) had a mild visual field deficit, 1 (6%) complained of moderate visual field impairment, and 5 (31%) had severe homonymous visual field loss. Cavernomas seated deeper than 2 cm from the pial surface carried a 4.4-fold risk of postoperative visual field deficit relative to superficial ones (p = 0.034). Six (55%) of the 11 patients presenting with seizures were seizure-free postoperatively. Eleven (69%) of 16 patients had no disability during the long-term follow-up. CONCLUSIONS Surgical removal of occipital cavernomas may carry a significant risk of postoperative visual field deficit, and the risk is even higher for deeper lesions. Seizure outcome after removal of these cavernomas appeared to be worse than that after removal in other supratentorial locations. This should be taken into account during preoperative planning.

Factors Determining Surgical Approaches to Basilar Bifurcation Aneurysms and Its Surgical Outcomes

BACKGROUND The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective. OBJECTIVE To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes. METHODS A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05. RESULTS One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size. CONCLUSION Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome.

Transient Cardiac Arrest Induced by Adenosine: A Tool for Contralateral Clipping of Internal Carotid Artery-Ophthalmic Segment Aneurysms.

BACKGROUND The disadvantages of a contralateral approach (CA) include deep and narrow surgical corridors and inconsistent ability to achieve proximal control of the supraclinoid internal carotid artery (ICA). However, a CA remains as a microsurgical option for selected ICA-ophthalmic (opht) segment aneurysms. OBJECTIVE To describe transient cardiac arrest induced by adenosine as an alternative tool to obtain proximal vascular control and soften the aneurysm sac in selected patients while performing a CA. METHODS From January 1998 to December 2013, we retrospectively identified 30 patients with ICA-opht segment aneurysms treated through a CA. Of those, 8 patients received an intravenous bolus of adenosine to induce transient cardiac arrest for softening of the aneurysm sac. We reviewed preoperative clinical status, characteristics of the contralateral aneurysm, adenosine doses, asystole time, recovery of normal circulation, outcome, and complications. RESULTS No preoperative cardiac or pulmonary pathologies were found in the study population. All contralateral ICA-opht segment aneurysms were unruptured, small, and saccular in shape. Transient cardiac arrest was induced because it was impossible to apply a temporary clip on the parent contralateral supraclinoid ICA. The median dose of adenosine was 22.5 mg (range, 5-50 mg) and the asystole time ranged from 20 to 40 seconds. All patients (n = 8) had good postoperative outcomes. No brain infarction or cardiac complications appeared postoperatively. CONCLUSIONS In selected patients, transient cardiac arrest induced by adenosine during a contralateral approach allows a brief flow arrest and softening of the aneurysm for safer exposure and clipping.