Daniel R. Klinger

Autologous and Acrylic Cranioplasty: A Review of 10 Years and 258 Cases

INTRODUCTION Cranioplasty is a well-accepted neurosurgical procedure that has application to a wide range of pathologies. Given the varied need for both autologous and synthetic cranial grafts, it is important to establish rates of procedural complication. METHODS A retrospective review identified 282 patients undergoing cranioplasty at our institution over a 10-year period, of which 249 patients underwent 258 cranioplasties with either autologous or acrylic flaps. A database including patient age, gender, presenting diagnosis, hospital of surgery, presence of a drain, and surgical complications was created in order to analyze the autologous and acrylic cranioplasty data. RESULTS A total of 28 complications were noted, yielding a rate of 10.9% (28/258). There was no statistically significant difference in infection rate between autologous and acrylic cranioplasty (7.2% vs. 5.8%, P=0.80). Male patients (P=0.007), tumor patients (P=0.02), and patients undergoing surgery at the county hospital (P=0.06) sustained a statistically higher rate of infection. Among traumatic brain injury patients, complex injuries and surgical involvement of the frontal sinus carried a significantly higher infection rate of 17% and 38.5%, respectively (P=0.03, P=0.001). Postoperative epidural hematoma requiring reoperation occurred in 3.5% (9/258) with no difference in hematoma rate with placement of a drain (P=1). CONCLUSIONS Cranioplasty carries a significant risk of infection and postoperative hematoma. In this large series comparing autologous and acrylic flaps, male patients, tumor patients, and those undergoing surgery at the county hospital were at increased risk of postoperative infection. Among traumatic brain injury cases, complex injuries and cases with surgical involvement of the frontal sinus may portend a higher risk.

Atypical Meningiomas: Recurrence, Reoperation, and Radiotherapy.

INTRODUCTION Atypical meningiomas (World Health Organization [WHO] grade II) represent a therapeutic challenge given their high recurrence rate and greater mortality compared with WHO grade I meningiomas. Traditionally, treatment has entailed attempts at gross total resection with radiation therapy reserved for residual disease or recurrences. METHODS We retrospectively reviewed our patient database of atypical meningioma (AM) patients over the past 10 years to assess surgical and radiotherapeutic treatments administered, treatment-related complications, radiographic-clinical progression after treatment, and mortality. We identified 45 patients with AMs and excluded 2 patients with incomplete hospital records. RESULTS The average age of our patients was 59.7 years. Forty-three AM patients underwent a total of 62 surgeries. Thirty patients underwent one initial surgical resection; 8 patients underwent a second resection for recurrence; 4 patients underwent 3 resections; and 1 patient underwent 4 resections for recurrences. The rate of postoperative complication was 12.9% (8/62). Five patients had postoperative wound infections requiring treatment, and 1 patient had a postoperative hematoma requiring surgical evacuation. There was 1 case of wound breakdown in a patient with a previously irradiated scalp and 1 case of lower-extremity venous thrombosis. Clinical follow-up ranged from 11-120 months with average follow-up of 43 months and median follow-up of 65 months. Nineteen patients (44%) developed clinical-radiographic evidence of recurrence at an average of 32.4 months after surgical resection. Of the recurrences, 12 were treated with repeat surgery and radiation therapy, 3 were treated with radiation therapy alone, and 2 with surgery alone. Radiation therapy included Gamma Knife (GK), CyberKnife (CK), intensity-modulated radiation therapy (IMRT), or some combination of these. There was one case of symptomatic radiation necrosis (1/15 or 6.6%). The survival rate at last follow-up of our patient cohort was 95.3%. CONCLUSIONS Given their high rates of recurrence, AMs require close clinical follow-up and an individualized treatment strategy. Reoperation, radiotherapy, or combination therapy can be effective strategies at managing disease progression while minimizing treatment-related morbidity. Treatment planning that attempts to anticipate future therapies in the form of further surgery or radiotherapy may improve clinical outcomes in these patients. Seventeen patients underwent adjuvant radiation therapy: 7 patients with intensity-modulated radiation therapy (IMRT), 4 patients with Gamma Knife (GK), and 2 with CyberKnife (CK). Four patients underwent multiple treatments.

The Far Lateral Approach for Foramen Magnum Meningiomas

Foramen magnum meningiomas (FMMs) are slow growing, most often intradural and extramedullary tumors that pose significant challenges to the skull base neurosurgeon. The indolent clinical course of FMMs and their insidious onset of symptoms are important factors that contribute to delayed diagnosis and relative large size at the time of presentation. Symptoms are often produced by compression of surrounding structures (such as the medulla oblongata, upper cervical spinal cord, lower cranial nerves, and vertebral artery) within a critically confined space. Since the initial pathological description of a FMM in 1872, various surgical approaches have been described with the aim of achieving radical tumor resection. The surgical treatment of FMMs has evolved considerably over the last 4 decades due to the progress in microsurgical techniques and development of a multitude of skull base approaches. Posterior and posterolateral FMMs can be safely resected via a standard midline suboccipital approach. However, controversy still exits regarding the optimal management of anterior or anterolateral lesions. Independently of technical variations and the degree of bone removal, all modern surgical approaches to the lower clivus and anterior foramen magnum derive from the posterolateral (or far-lateral) craniotomy originally described by Roberto Heros and Bernard George. This paper is a review of the surgical management of FMMs, with emphasis on the far-lateral approach and its variations. Clinical presentation, imaging findings, important neuroanatomical correlations, recurrence rates, and outcomes are discussed.

The treatment of cavernous sinus meningiomas: evolution of a modern approach

Cavernous sinus meningiomas (CSMs) are challenging lesions for the skull base neurosurgeon to manage given their close association with cranial nerves II-VI and the internal carotid artery. In the 1980s and early 1990s, with advancements in microsurgical techniques, increasing knowledge of the relevant microsurgical neuroanatomy, and the advent of advanced skull base surgical approaches, the treatment of CSMs involved attempts at gross-total resection (GTR). Initial fervor for a surgical cure waned, however, as skull base neurosurgeons demonstrated the limits of complete resection in this region, the ongoing issue of potential tumor recurrences, and the unacceptably high cranial nerve and vascular morbidity associated with this strategy. The advent of radiosurgery and its documented success for tumor growth control and limited morbidity in cavernous lesions has helped to shift the treatment goals for CSMs from GTR to tumor control and symptom relief while minimizing treatment- and lesion-associated morbidity. The authors review the relevant microanatomy of the cavernous sinus with anatomical and radiographic correlates, as well as the various treatment options. A modernized, multimodality treatment algorithm to guide management of these lesions is proposed.

Race and Hemorrhage in Cerebral Arteriovenous Malformations

he ability to determine the rupture risk of an arteriovenous malformation (AVM) (either initial or subseT quent rupture) is a key factor for the clinician who counsels these patients and makes treatment recommendations. The low prevalence of AVMs in the general population, estimated at 0.01%, has made natural history studies of these lesions challenging and limited. The majority of important natural history studies have either evaluated a homogenous, intransient patient population or a patient cohort referred to a regional tertiary referral center with the inherent biases of both these approaches. Despite heterogeneous results when comparing individual studies, what we have gathered from these studies is that the annual rupture risk of most AVMs is likely between 2% and 4%, with previous rupture likely increasing this risk. Further evidence is suggestive, but not conclusive, that deep-seated AVMs, deep venous drainage, and the presence of associated aneurysms may also increase risk of bleed (4). Relatively few studies have elucidated a strong association between AVM hemorrhage and patient demographic factors.