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Objective Many surgeons advocate for watertight dural reconstruction after posterior fossa surgery given the significant risk of cerebrospinal fluid (CSF) leak. Little evidence exists for posterior fossa dural reconstruction utilizing monolayer collagen matrix onlay graft in a non-watertight fashion. Our objective was to report the results of using collagen matrix in a non-watertight fashion for posterior fossa dural reconstruction. Methods We conducted a retrospective review of operations performed by the senior author from 2004–2011 identified collagen matrix (DuraGen) use in 84 posterior fossa operations. Wound complications such as CSF leak, infection, pseudomeningocele, and aseptic meningitis were noted. Fisher's exact test was performed to assess risk factor association with specific complications. Results Incisional CSF leak rate was 8.3% and non-incisional CSF leak rate was 3.6%. Incidence of aseptic meningitis was 7.1% and all cases resolved with steroids alone. Incidence of palpable and symptomatic pseudomeningocele in follow-up was 10.7% and 3.6% respectively. Postoperative infection rate was 4.8%. Previous surgery was associated with pseudomeningocele development (p

Epidermoid tumor of the cavernous sinus is rare. The aim of this case report is to discuss the role of neuroendoscopes in the removal of such lesions. A 21-year-old man presented with 6-year history of progressive headache, diplopia, and visual disturbance. Work-up revealed an epidermoid tumor located in the right cavernous sinus. An extradural transcavernous approach was utilized via a traditional frontotemporal craniotomy with endoscopic assistance. The postoperative course was uneventful with immediate improvement of the patient's headache. Postoperative magnetic resonance imaging demonstrated complete removal of the tumor. There were no signs of recurrence during a 2-year follow-up period. The endoscope is a useful tool for removing epidermoid tumors from the cavernous sinus and enhances visualization of areas that would otherwise be difficult to visualize with microscopes alone. Endoscopes also help minimize the retraction of neurovascular structures.

Background Meningiomas are the most common benign brain tumors that are frequently followed-up by neurologists, general practitioners, and neurosurgeons. Some recent studies advocate the accurate volumetric method (VM) over measuring the linear maximum diameter although its clinical significance still remains unknown. The aim of this study is to directly compare the linear method (LM) and VM to delineate the characteristics of both measurements. Methods Between 2003 and 2010, growth analysis using magnetic resonance imaging DICOM files was performed for 189 meningiomas in 161 patients at the Cleveland Clinic. In LM, a minimum increase of 2 mm in maximum diameter was defined as tumor growth. The absolute volume growth (VG, in cm(3)) was calculated for each tumor. Results Linear growth (LG) was seen in 71 tumors (37.6%) within the median follow-up of 2.0 years. These tumors with LG showed a mean VG of 2.80 cm(3). Some large LG-positive tumors can be larger than estimated from LG. In addition, the skull base location was correlated to greater VG. On the other hand, 118 tumors without LG demonstrated the minimal actual volume increase, i.e., mean VG of 0.16 cm(3). Although a small subset of these LG-negative tumors might have slightly high VG when they were large, the location of tumor had no correlation to VG. Conclusions Our data demonstrated some important precautions in measuring the tumor growth. We believe that it is mandatory in the conservative management of meningiomas to correctly understand benefits and potential limitations of different measurement methods utilized.

Objective: Intraosseous cavernous angioma (CA) of the petrous bone is rare and preoperative diagnosis can be challenging, especially when its epicenter is outside the internal auditory canal (IAC) or geniculate ganglion. Methods: A 45-year-old man presented to our clinic with right-sided hearing loss, tinnitus, and unsteadiness. Neuroimaging revealed a right posterior petrous mass. Aggressive subtotal resection with decompression of the IAC was achieved through a right suboccipital craniotomy. Histopathological findings were consistent with CA. Conclusion: As was the case with this patient, we believe that CA should be included in the differential diagnosis of petrous region pathology with bony involvement. Surgery is warranted due to its expansive nature and to decompress the adjacent neural structures.

Introduction: This study was conducted to evaluate the natural history of meningiomas with respect to their demographic, clinical, and radiographic aspects. Materials and Methods: In 168 patients, 175 conservatively managed meningiomas were reviewed retrospectively. Growth was measured on the maximal diameter of each tumor. Two groups were formed: tumors with growth (G) and tumors without growth (WG), and these were stratified according to age, gender, ethnicity, body mass index (BMI), clinical symptoms, tumor location, size, radiological features, and histopathological grades. Results: Eighty of 175 (46%) meningiomas demonstrated radiological evidence of growth, with a mean follow-up of 3.7 years and a mean growth rate of 1.20 mm per year. Mean age in the G and WG groups were 58 and 65 years, respectively (P = 0.001). Incidence of tumor growth was higher in the following groups, with statistical significance: age younger than 60 years (P = 0.001), absence of calcification (P = 0.001), iso- or low-signal intensity on T2-weighted MR images (P = 0.019), and histological grade. The difference was most striking when WHO grade II meningiomas (5.94 mm/y) were compared with grade I meningiomas (2.18 mm/y). There was no statistical difference with regard to gender, race, BMI, tumor location, and initial tumor size. In 10 meningiomas (5.8%), growth resulted in new symptoms. Thirty-three meningiomas (18.9%) eventually required surgery. Conclusions: Our results showed a higher growth rate of meningiomas in younger patients, in tumors with high T2 signal and no calcification, and in those with higher histological grade. Therefore, we believe that it would be advisable to monitor such tumors more closely.

Introduction: In this study, we aimed at assessing the significance of the tentorial alignment in approaching the trigeminal nerve through a suboccipital retrosigmoid craniotomy. Methods: Four parameters were evaluated using preoperative MRI and intraoperative measurements in 34 consecutive patients who underwent microvascular decompression of the trigeminal nerve via a suboccipital retrosigmoid approach: (1) the angle between the tentorium and the line drawn from the hard palate (tentorial angle, TA); (2) the angle between the tentorium and the line connecting the opisthion to the inion (occipital angle, OA); (3) the angle between the lines drawn along the petrous bones ventral to the internal auditory canals (petrous angle, PA); (4) the intraoperative distance between the trigeminal nerve and the acousticofacial bundle (distance, d). Statistical analysis was performed using Pearson's correlation test and t-test as appropriate. Results: Mean values were 50.1 ± 12.2 for TA, 82.3 ± 9.9 for OA, 104.6 ± 12.2 for PA, and 3.2 ± 1.5 mm for d. There was a negative correlation between TA and d (r = − 0.233, p = 0.09): the mean d was 3.7 ± 1.7 mm for TA 51 (p = 0.06). A positive correlation was detected between TA and OA (r = 0.336, p = 0.02). Conclusions: The distance between the trigeminal nerve and the acousticofacial bundle decreases in the presence of a steep tentorial angle. This limits the working field at the petrotentorial sulcus. Awareness of such anatomical features at the time of preoperative planning is of paramount importance to avoid complications during the procedure.

Objective: To quantify and compare the carotico-oculomotor triangle (COT) area before and after extradural anterior clinoidectomy (AC). Methods: Ten cadaveric heads were dissected bilaterally. Before and after an extradural. AC, the following points were measured: (1) the internal carotid artery (ICA) bifurcation to the tip of the anterior clinoid process (ACP) (A) and to the distal dural ring (A'), (2) the ICA bifurcation to the point where the oculomotor nerve becomes obscured by the tentorial fold (B) and to the porus oculomotoris after incision of the tentorial fold (B') and (3) the tip of the ACP to the point where the oculomotor nerve becomes obscured by the tentorial incisura (C) and from the distal. dural ring to the porus oculomotoris (C'). The area of the COT was calculated before and after AC (Delta ABC and Delta A'B'C', respectively). Results: The mean values were as follows: A: 9.15 +/- 0.93 mm, A': 13.45 +/- 0.82 mm; B: 7.80 +/- 1.24 mm, B': 9.90 +/- 1.21 mm; C: 7.15 +/- 0.99 min, C': 9.3 +/- 1.26 mm; Delta ABC: 26.26 +/- 16.05 mm(2), Delta A'B'C': 45.06 +/- 8.92 mm(2). Conclusions: Extradural AC enhances the exposure of the COT almost twofold. This increased exposure can be of significant help during resection of lesions of the parasellar and basilar apex regions.

Objective:This study was undertaken to assess the displacement patterns and shifts of the normal pituitary gland in sellar pathologies on MRI and to determine if the position of the bright spot (BS) represents a predicting factor for the position of the residual adenohypophysis (RAH) in pathological conditions.Methods:In a control group of 102 patients without any pituitary pathology, the presence of the BS was evaluated. In 100 patients with intra- or suprasellar pathologies, presence and respective topography of BS and RAH were scrutinized on MRI, according to lesion type, size, endocrine status and intra-operative findings in the surgical group.Results:The BS was visible in 91.2% of 102 cases in the control group, as compared to 75 of the 100 patients with sellar lesions. Location of RAH was identified in 58% of the patients, and RAH enhanced more than the lesion in all cases after contrast infusion. The RAH was identified in 65.3% of the 75 “BS positive” patients, as compared to 36% of the 25 “BS negative”. The normal residual gland was visualized intra-operatively in 63.5% of the 52 operated patients: in 37 “BS positive” patients, it was visualized intra-operatively in 81.1% and in 28 “RAH positive” patients, it was identified in 82.1%.Conclusion:The BS can be identified in the majority and RAH in more than half of the cases with pituitary lesions on MRI. Positions of both the BS and RAH help predict the location of the normal residual gland during surgery and, therefore, may contribute to preserving the pituitary function.

Summary: The basilar artery as the origin of the ophthalmic artery is extremely rare. A 48-year-old patient had undergone angiography for suspicion of a right middle cerebral artery aneurysm. No aneurysm was detected. Vertebral artery injections demonstrated the left ophthalmic artery originating from the basilar trunk. Current embryologic theories fall short in explaining this entity. Awareness of neuroanatomic variations is of paramount importance in diagnosis and treatment of vascular lesions of the brain.

The results of the International Subarachnoid Aneurysm Trial (ISAT) drew attention from both scientific and lay press, impacting the management of aneurysm patients significantly. In this review, the ISAT report was analyzed critically and the available literature was scrutinized stratifying the common criticisms as to the weak aspects of this study. The aim of ISAT was to compare the safety and efficacy of endovascular coiling with neurosurgical clipping for aneurysms, which were suitable for both treatments. The results showed a 22.5% relative and 6.9% absolute risk reduction at one year in the disability outcome of patients who were treated with coiling. However, long-term risk of re-bleeding from the treated aneurysms and the risk of repeat procedures was higher in this group also. Lack of angiographic data following the initial treatment and long-term follow-up represents one of the main flaws of this study. The outcome assessment scale, biases regarding patient selection and center participation criteria were further issues of criticism. The results of ISAT are not sufficient to provide a definitive answer as to the superiority of endovascular treatment over microsurgery, although coiling appears to produce less peri-procedural morbidity in a selected group of patients. An optimum outcome assessment should include a universally accepted scale and a detailed long-term angiographic outcome.

In the surgical treatment of carpal tunnel syndrome, debate has commonly focused on whether decompression should be performed by open or blind techniques. Contrarily, the goal of the present study was to determine whether instead of simple section, partial excision of the transverse carpal ligament has contributed to better results. Because complete healing of the transverse carpal ligament observed during reoperations has been reported elsewhere, the charts of 75 carpal tunnel syndrome patients who had been treated with open technique at Dokuz Eylul University were reviewed. Statistical analysis was performed rising the Fisher's exact test and Student's t test when appropriate. Thirty-five patients had been treated with simple section of the transverse carpal ligament, whereas 40 had been treated with partial excision. Internal neurolysis was also performed in 19 of the patients, 11 of whom were treated with partial excision. The average follow-up time was 3.8 years. The comparisons regarding the overall operative outcomes did not show any significant difference between the two different techniques of releasing the transverse carpal ligament. In patients treated without neurolysis, results of partial excision of the transverse carpal ligament improved when compared with those of simple section, but this superiority was not statistically significant. There seemed to be statistically higher reoperation rates and worse outcomes after neurolysis (p < 0.05). Reoperation was required in eight patients (11 percent). Five of the patients who underwent reoperation had initially been treated with partial excision and neurolysis, whereas two had been treated with simple section and neurolysis. Another patient who had undergone reoperation had initially undergone only simple section. The mean time to return to work or daily activities did not differ between the types of applied technique for releasing the transverse carpal ligament. However, neurolysis lengthened these periods significantly when performed (p < 0.05). In the present study, partial excision of the transverse carpal ligament without adding neurolysis offered relatively better results than simple section. Verification of this finding endocscopically, if applicable, may improve the success rate of surgical therapy in patients with carpal tunnel syndrome.