Effect of perioperative aspirin use on hemorrhagic complications in elective craniotomy for brain tumors: results of a single-center, retrospective cohort study

OBJECTIVE

In daily practice, neurosurgeons face increasing numbers of patients using aspirin (acetylsalicylic acid, ASA). While many of these patients discontinue ASA 7-10 days prior to elective intracranial surgery, there are limited data to support whether or not perioperative ASA use heightens the risk of hemorrhagic complications. In this study the authors retrospectively evaluated the safety of perioperative ASA use in patients undergoing craniotomy for brain tumors in the largest elective cranial surgery cohort reported to date.

METHODS

The authors retrospectively analyzed the medical records of 1291 patients who underwent elective intracranial tumor surgery by a single surgeon from 2007 to 2017. The patients were divided into three groups based on their perioperative ASA status: 1) group 1, no ASA; 2) group 2, stopped ASA (low cardiovascular risk); and 3) group 3, continued ASA (high cardiovascular risk). Data collected included demographic information, perioperative ASA status, tumor characteristics, extent of resection (EOR), operative blood loss, any hemorrhagic and thromboembolic complications, and any other complications.

RESULTS

A total of 1291 patients underwent 1346 operations. The no-ASA group included 1068 patients (1112 operations), the stopped-ASA group had 104 patients (108 operations), and the continued-ASA group had 119 patients (126 operations). The no-ASA patients were significantly younger (mean age 53.3 years) than those in the stopped- and continued-ASA groups (mean 64.8 and 64.0 years, respectively; p < 0.001). Sex distribution was similar across all groups (p = 0.272). Tumor locations and pathologies were also similar across the groups, except for deep tumors and schwannomas that were relatively less frequent in the continued-ASA group. There were no differences in the EOR between groups. Operative blood loss was not significantly different between the stopped- (186 ml) and continued- (220 ml) ASA groups (p = 0.183). Most importantly, neither hemorrhagic (0.6%, 0.9%, and 0.8%, respectively; p = 0.921) nor thromboembolic (1.3%, 1.9%, and 0.8%; p = 0.779) complication rates were significantly different between the groups, respectively. In addition, the multivariate model revealed no statistically significant predictor of hemorrhagic complications, whereas male sex (odds ratio [OR] 5.9, 95% confidence interval [CI] 1.7-20.5, p = 0.005) and deep-extraaxial-benign ("skull base") tumors (OR 3.6, 95% CI 1.3-9.7, p = 0.011) were found to be independent predictors of thromboembolic complications.

CONCLUSIONS

In this cohort, perioperative ASA use was not associated with the increased rate of hemorrhagic complications following intracranial tumor surgery. In patients at high cardiovascular risk, ASA can safely be continued during elective brain tumor surgery to prevent potential life-threatening thromboembolic complications. Randomized clinical trials with larger sample sizes are warranted to achieve a greater statistical power.

Microsurgical Gross Total Resection of a WHO Grade II Cerebellopontine Angle Ependymoma in an Adult

Infratentorial ependymomas that arise in the fourth ventricle and extend into the cerebellopontine angle (CPA) through the foramina of Luschka are well described. However, a primary CPA location of an ependymoma is distinctly uncommon. In this video, we present a 46-year-old man with episodes of dizziness, left-sided tinnitus, imbalance, double vision, and nausea. An magnetic resonance imaging (MRI) scan of the head showed a large mass lesion centered in the CPA with heterogenous enhancement. Differential diagnosis included ependymoma, meningioma, schwannoma of the vestibular nerve, or lower cranial nerves, and choroid plexus papilloma. He underwent microsurgical gross total resection of the tumor via a retrosigmoid approach. Direct stimulation of the cranial nerves was performed throughout the case and there was no attachment of the tumor to any cranial nerve to suggest that this might be a schwannoma. The tumor encased important vasculature, including the posterior-inferior cerebellar artery. The histopathology was a grade II ependymoma. The patient tolerated the surgery well and his postoperative course was uneventful. He remained neurologically intact. He received radiation therapy and there was no recurrent or residual disease on follow-up studies. This video demonstrates important steps of the surgical approach and microsurgical resection techniques for this type of challenging tumor.

The link to the video can be found at: https://youtu.be/KK-y6EYh888 .

Gross Total Resection of a Jugular Foramen Thyroid Medullary Metastasis via a Transjugular Transsigmoid Approach

Surgical resection of jugular foramen tumors poses a significant challenge to skull base surgeons with the selection of an appropriate surgical approach, a matter of some debate. Jugular foramen metastatic tumors may mimic paragangliomas, and in some selected cases surgical resection is needed. In this video, we demonstrate the microsurgical gross total resection of a jugular foramen tumor via a postauricular trans-jugular trans-sigmoid approach. The patient is a 61-year-old man with a 7-year history of medullary thyroid cancer, who underwent three neck operations and radiation to the neck. He developed lower cranial nerve palsies (IX, X, and XI) with preoperative aspiration deficits, dysphonia, status post phonosurgery for vocal cord paralysis, profound sensorineural hearing loss, and muscle atrophy of the left shoulder. He initially received stereotactic radiation of the jugular foramen tumor at an outside hospital without histopathological diagnosis. Follow-up magnetic resonance images (MRIs) showed progressive enlargement of the tumor over the postradiation year. The decision was made to resect this tumor to enable histopathological diagnosis, and to provide local tumor control, since his primary disease has been stable. He underwent microsurgical gross total resection via a transjugular transsigmoid approach. After skeletonizing the sigmoid sinus and jugular bulb, the sigmoid sinus was ligated and rolled toward the jugular bulb, where the major part of the tumor was. Then, using the transjugular route, the tumor was removed en bloc. The surgery and postoperative course were uneventful. The histopathology was a thyroid medullary cancer metastasis. He was followed with serial MRIs, and there was no recurrent tumor at 2 years follow-up. In this video, microsurgical techniques and important steps for the resection of a jugular foramen metastatic tumor are demonstrated. The link to the video can be found at: https://youtu.be/oXC6fX2CC84 .

Microsurgical Gross Total Resection of a Large Residual/Recurrent Vestibular Schwannoma via Translabyrinthine Approach

Although, gross total resection in large vestibular schwannomas is an ideal goal, subtotal resection is frequently performed due to lack of expertise, concerns for facial palsy, or overuse of stereotactic radiation. In this video, we present a 31-year-old man with a 7-year history of tinnitus, dizziness, and hearing loss. The patient had a subtotal resection of a 2.5 cm right-sided vestibular schwannoma via retrosigmoid craniotomy at an outside hospital. He was referred for further surgical resection due to the increased size of the tumor on surveillance magnetic resonance imagings (MRIs) and worsening symptoms. MRI showed a residual/recurrent large schwannoma with extension to the full length of the internal acoustic canal and brain stem compression. He underwent microsurgical gross total resection via a translabyrinthine approach. The facial nerve was preserved and stimulated with 0.15 mA at the brainstem entry zone. He awoke with House–Brackmann grade III facial function, with an otherwise uneventful postoperative course. In this video, microsurgical techniques and important resection steps for this residual/recurrent vestibular schwannoma are demonstrated, and nuances for microsurgical technique are discussed.

The link to the video can be found at: https://youtu.be/a0ZxE41Tqzw .

Gross Total Resection of Large Cerebellopontine Angle Meningioma with a Supratentorial Extension via Retrosigmoid Approach with Suprameatal Drilling and Tentorial Sectioning

Meningiomas are the second most common neoplasm in the cerebellopontine angle (CPA), and are challenging lesions to treat surgically. With significant refinements in surgical techniques, operative morbidity, and mortality have been substantially reduced. Total or near-total surgical resection can be accomplished in the majority of cases via appropriately selected approaches, and with acceptable morbidity. In this video, we present a 51-year-old woman, who had a 2-year history of vertigo with symptoms that progressed over time. She presented with blurry vision, sensorineural hearing loss, tinnitus, left-sided facial numbness, and double vision. Magnetic resonance imaging (MRI) showed a left-sided homogeneously enhancing mass at CPA with a supratentorial extension. MRI appearance was consistent with a CPA meningioma with supratentorial extension. The patient underwent surgical resection via a retrosigmoid approach. Suprameatal drilling and tentorial sectioning were necessary to achieve gross total resection. The surgery and postoperative course were uneventful. The histopathology was a WHO (world health organization) grade I meningioma. MRI showed gross total resection of the tumor. After a 1.5-year follow-up, the patient is continuing to do well with no residual or recurrent disease. In this video, microsurgical techniques and important steps for the resection of this challenging meningioma of the cerebellopontine angle are demonstrated.

The link to the video can be found at: https://youtu.be/CDto52GxrG4 .

Microsurgical Resection of Anaplastic Ependymoma of the Cerebellopontine Angle in an Adult: 3-Dimensional Operative Video

Infratentorial ependymomas usually arise in the fourth ventricle and extend into the cerebellopontine angle (CPA) through the foramina of Luschka is well described. A primary CPA location of an ependymoma is distinctly uncommon.

 In this 3-dimensional video, we present a 38-yr-old woman with a 1-mo history of vertigo and slow left sided gaze drift. She underwent microsurgical gross total resection of the CPA ependymoma via retrosigmoid approach. The histopathology was grade III anaplastic ependymoma. She tolerated the surgery well and her postoperative course was uneventful. She received radiation therapy and there was no recurrent disease in follow-up studies.

 Important steps of the surgical approach and microsurgical techniques in resection of these challenging tumors are demonstrated in this 3-dimensional surgical video. The patient consented to publication of her image.

Mapping of the internal capsule with subcortical stimulation for gross-total resection of a thalamic metastatic tumor

Although the surgical treatment of thalamic tumors remains challenging due to the proximity to the internal capsule, safe resection of gliomas or metastatic tumors of the thalamus are possible in some selected cases due to a better understanding of microsurgical anatomy and due to advances in neurophysiological mapping and monitoring. In this video, the authors demonstrate the use of mapping of the internal capsule with direct subcortical stimulation for the resection of a metastatic tumor. The patient is a 58-year-old man with a history of renal cell carcinoma and metastasis in the left thalamus and parieto-occipital region. He underwent stereotactic radiation of both tumors at an outside hospital. Due to the increased size of both tumors and surrounding vasogenic edema, he was referred to the authors for resection. He underwent gross-total resection via an interhemispheric transcallosal approach. His postoperative course was uneventful and did not have any focal neurological deficits, including motor, sensory, or visual functions. The authors' surgical approach to this metastatic thalamic tumor and the intraoperative real-time direct subcortical stimulation of the internal capsule during surgery are demonstrated in this video. The video can be found here: https://youtu.be/DmDxjJUSZWU .

Frontal lobe intracerebral schwannoma mimicking metastatic lesion in a patient with papillary thyroid carcinoma

Intracerebral schwannomas are quite rare. Due to their rarity and lack of pathognomonic imaging features, intracerebral schwannoma may be overlooked in the initial differential diagnosis of an intra-axial mass with heterogeneous ring enhancement, such as a high-grade glioma, metastasis or lymphoma. Here, we present a 21-year-old woman with prior diagnosis of papillary thyroid carcinoma and recent history of seizures who had a heterogeneously ring-enhancing left frontal lobe mass. Our presumptive diagnosis was a metastatic tumor since she had a history of thyroid cancer. Because of uncertainty in preoperative differential diagnosis, the decision was made to proceed with excisional biopsy of the tumor via craniotomy. She underwent uneventful gross total resection of the tumor that histopathology revealed as an intracerebral schwannoma.

A novel, low-cost, reusable, high-fidelity neurosurgical training simulator for cerebrovascular bypass surgery

OBJECTIVE

Cerebrovascular bypass surgery is a challenging yet important neurosurgical procedure that is performed to restore circulation in the treatment of carotid occlusive diseases, giant/complex aneurysms, and skull base tumors. It requires advanced microsurgical skills and dedicated training in microsurgical techniques. Most available training tools, however, either lack the realism of the actual bypass surgery (e.g., artificial vessel, chicken wing models) or require special facilities and regulations (e.g., cadaver, live animal, placenta models). The aim of the present study was to design a readily accessible, realistic, easy-to-build, reusable, and high-fidelity simulator to train neurosurgeons or trainees on vascular anastomosis techniques even in the operating room.

METHODS

The authors used an anatomical skull and brain model, artificial vessels, and a water pump to simulate both extracranial and intracranial circulations. They demonstrated the step-by-step preparation of the bypass simulator using readily available and affordable equipment and consumables.

RESULTS

All necessary steps of a superficial temporal artery-middle cerebral artery bypass surgery (from skin opening to skin closure) were performed on the simulator under a surgical microscope. The simulator was used by both experienced neurosurgeons and trainees. Feedback survey results from the participants of the microsurgery course suggested that the model is superior to existing microanastomosis training kits in simulating real surgery conditions (e.g., depth, blood flow, anatomical constraints) and holds promise for widespread use in neurosurgical training.

CONCLUSIONS

With no requirement for specialized laboratory facilities and regulations, this novel, low-cost, reusable, high-fidelity simulator can be readily constructed and used for neurosurgical training with various scenarios and modifications.

The Impact of Intracranial Tumor Proximity to White Matter Tracts on Morbidity and Mortality: A Retrospective Diffusion Tensor Imaging Study

Background

Using diffusion tensor imaging (DTI) in neurosurgical planning allows identification of white matter tracts and has been associated with a reduction in postoperative functional deficits.

Objective

This study explores the relationship between the lesion-to-tract distance (LTD) and postoperative morbidity and mortality in patients with brain tumors in order to evaluate the role of DTI in predicting postoperative outcomes.

Methods

Adult patients with brain tumors (n = 60) underwent preoperative DTI. Three major white matter pathways (superior longitudinal fasciculi [SLF], cingulum, and corticospinal tract) were identified using DTI images, and the shortest LTD was measured for each tract. Postoperative morbidity and mortality information was collected from electronic medical records.

Results

The ipsilesional corticospinal tract LTD and left SLF LTD were significantly associated with the occurrence rate of total postoperative motor (P = .018) and language (P < .001) deficits, respectively. The left SLF LTD was also significantly associated with the occurrence rate of new postoperative language deficits (P = .003), and the LTD threshold that best predicted this occurrence was 1 cm (P < .001). Kaplan–Meier log-rank survival analyses in patients having high-grade tumors demonstrated a significantly higher mortality for patients with a left SLF LTD <1 cm (P = .01).

Conclusion

Measuring tumor proximity to major white matter tracts using DTI can inform clinicians of the likelihood of postoperative functional deficits. A distance of 1 cm or less from eloquent white matter structures most significantly predicts the occurrence of new deficits with current surgical and imaging techniques.

Hypertrophic Olivary Degeneration: Neurosurgical Perspective and Literature Review

BACKGROUND

Hypertrophic olivary degeneration (HOD) occurs because of posterior fossa or brainstem lesions that disrupt the dentato-rubro-olivary tract, well known as the Guillain-Mollaret triangle. Clinical and radiologic hallmarks of this condition are palatal myoclonus and T2 hyperintensity of the inferior olivary complex on magnetic resonance imaging (MRI), respectively. Because symptomatic HOD can complicate the recovery of patients with posterior fossa or brainstem lesions, the purpose of this study is to evaluate clinical and imaging findings of patients with HOD.

METHODS

Sixteen patients (8 female and 8 male) with a mean age of 40.7 years, (range, 5-83 years) years were included in this study based on clinical symptoms and MRI findings.

RESULTS

We reviewed the clinical and imaging findings in 16 cases of HOD at our institution. Seven patients (43.7%) had posterior fossa tumors, 6 patients (37.5%) had cavernoma, 2 patients (12.5%) sustained traumatic brain injury, and only 1 patient (6.2%) had cerebellar infarction. Posterior fossa surgery was performed in 13 (81.2%) of these patients. HOD was detected a mean of 7.2 months (range, 0.5-18 months) after surgery or primary neurologic insult. Unilateral HOD was observed in 10 patients (62.5%), while bilateral HOD was observed in only 6 patients (37.5%). Seven patients (43.7%) were asymptomatic for HOD, whereas 5 patients (31.2%) had symptoms attributable to HOD. Two patients died because of primary tumors, although mean follow-up after detection of HOD on MRI was 52.2 months (range, 1-120 months) in the remaining 14 patients. In these cases, no change in clinical symptoms or imaging findings was detected during follow-up.

CONCLUSIONS

In this series, posterior fossa tumors and cavernomas were the most common causes of HOD. Although most of the patients with HOD remained asymptomatic, HOD complicated the course of recovery in almost one quarter of the patients included in this study. Neurosurgeons should be aware of HOD, which has characteristic clinical and imaging findings. In addition, HOD can complicate the recovery of patients with disruption to the dentato-rubro-olivary tract.

Management of occipitocervical junction and upper cervical trauma

Objective:

The treatment modality of occipitocervical junction (OCJ) and upper cervical traumas carries great importance because of unique form of bone, complex ligamentous, and neurovascular structure.

Materials and Methods:

Eighty-eight patients were admitted to Mersin University Department of Neurosurgery between January 2007 and January 2017 for injuries of the OCJ and upper cervical spine and evaluated retrospectively. In the group, there were 60 male, 28 female patients in the mean age of 42.9 (18–87) years. Among those, 2 occipital condyle fractures, 28 C1 fractures (26 isolated and 2 with transverse ligament injury), 9 combined C1/C2 fractures, 6 rotatory C1/C2 dislocations, and 43 C2 fractures (32 odontoid, 5 Hangman's, and 6 miscellaneous fractures) were diagnosed. In addition to clinical cases, ten cadavers were used to study the OCJ in a step-wise manner.

Results:

Occipital condyle fractures, isolated C1 fractures, and rotatory C1/C2 dislocations were treated conservatively. Two patients with C1 fracture including transverse ligament injury were operated in one of the methods of C1–C2 fusion which is posterior sublaminar wiring. Five patients having Type II odontoid fracture were treated surgically. One instable Hangman's fracture patient was treated as anterior cervical discectomy and fusion.

Conclusions:

Cases with isolated C1 fracture with intact transverse ligament should be conservatively treated without surgical approach. Atlas fractures with transverse ligament rupture, odontoid Type II fractures with dislocation >6 mm, and unstable Hangman's fractures required surgical treatment. Vital neurovascular, ligamentous, and accompanying bone structures should be evaluated for diagnosis and treatment modality. In addition, patient's health status, patient's treatment preference, and surgical team experience are the affecting factors for the decision of surgery.

Overcoming End-to-End Vessel Mismatch During Superficial Temporal Artery-Radial Artery-M2 Interposition Grafting for Cerebral Ischemia: Tapering Technique

Cerebral revascularization procedures, such as the external carotid-internal carotid bypass, have been used in the clinical management of cerebral ischemic states. Among the most commonly performed bypasses is the superficial temporal artery-middle cerebral artery (STA-MCA) bypass to restore cerebral blood flow. In cases of a foreshortened STA donor vessel, a radial artery (RA) graft is often used as an interposition graft between the STA and MCA. However, addressing the vessel size mismatch between the radial artery and donor can be problematic and challenging. We present the case of an 80-year-old male presenting with positional-onset expressive aphasia and right-sided hemiparesis. Computed tomography perfusion demonstrated a diffusion-perfusion mismatch in a left MCA distribution. Angiography showed a complete left internal cerebral artery occlusion and poor distal filling of the STA. We performed an external carotid artery-to-internal carotid artery bypass through interposing an RA graft to the STA proximally with an end-to-end anastomosis and to the MCA distally using an end-to-side anastomosis. The mismatch between 2 bypass vessel sizes was corrected by removing a small piece from the RA graft at 1 margin and suturing it to itself to reduce the size of the RA vessel diameter opening on the side used to sew to the STA. The patient did well clinically with improved right-sided strength, a patent graft, and no postoperative complications. Addressing vessel mismatch when using RA interposition grafts for bypass is challenging. Various operative approaches to address mismatch should be individualized on the basis of the particular vascular anatomy and needs of the case. Nevertheless, our method of cutting and suturing 1 side of the RA graft into a semiblind end to match donor vessel diameter may be of use to cerebrovascular surgeons in select cases.

Metastatic prostate adenocarcinoma to intradural foramen magnum

Intradural metastatic tumors are rarely reported in foramen magnum (FM), including cases of melanoma, pituitary carcinoma, thyroid carcinoma, and prostate carcinoma metastases. We report a 68-year-old male who presented with right-sided headache, progressive swallowing difficulty requiring gastrostomy tube and hoarseness over the course of 1 year. Images revealed a heterogeneous, contrast-enhancing lesion in the FM that compressed the anterior aspect of the medulla and upper spinal cord. Although metastatic tumor was considered in differential diagnosis, presumptive diagnosis was FM meningioma due to lack of bone destruction or sclerosis on CT and T2W isointense and T1W hypointense appearance on MRI. The patient underwent gross total resection via right far-lateral transcondylar approach. Histopathological examination revealed prostate carcinoma metastasis. To the best of our knowledge this is the second case report of an intradural prostate carcinoma metastasis in the FM.

Emergency resection of brainstem cavernous malformations

Brainstem cavernous malformations (CMs) pose significant challenges to neurosurgeons because of their deep locations and high surgical risks. Most patients with brainstem CMs present with sudden-onset cranial nerve deficits or ataxia, but uncommonly patients can present in extremis from an acute hemorrhage, requiring surgical intervention. However, the timing of surgery for brainstem CMs has been a controversial topic. Although many authors propose delaying surgery into the subacute phase, some patients may not tolerate waiting until surgery. To the best of the authors' knowledge, emergency surgery after a brainstem CM hemorrhage has not been described. In cases of rapidly progressive neurological deterioration, emergency resection may often be the only option. In this retrospectively reviewed small series of patients, the authors report favorable outcomes after emergency surgery for resection of brainstem CMs.

The sulci of the inferior surface of the temporal lobe: An anatomical study

Understanding the anatomy of temporal lobe sulci and their variations can allow for safer neurosurgical approaches. Although the inferior temporal sulci and their relations to each other has been described by several authors, the nomenclature used has not been universal. The aim of this study was to investigate the anatomic features of the three main sulci of the inferior temporal lobe and provide a simple description of complex patterns among these sulci. Sulcal variations and their relations were examined in seventy formalin-fixed, adult cadaveric cerebral hemispheres. We recommend a simple but modified classification specifically for anatomic variations of the rhinal and collateral sulci. Furthermore, we describe the frequency of occipitotemporal sulci that contain 5 and 6 segments, not previously mentioned. The length and depth of all sulci were measured in all samples. Additionally, more detailed results regarding the patterns, courses, connections, relationships and measurements were given. Understanding of the complex anatomy of this clinically important region is of benefit to neurosurgeons, providing necessary guidance for neurosurgical approaches to the inferior surface of the temporal lobe. Clin. Anat. 29:932-942, 2016. © 2016 Wiley Periodicals, Inc.