Faculty Bibliography

OBJECTIVE:Surgical resection of posterior fossa metastases (PFM) includes either suboccipital craniotomy or suboccipital craniectomy. The optimal surgical technique is yet to be defined. We examined the association between the chosen surgical approach and the occurrence of postoperative complications. METHODS:We retrospectively evaluated medical records and imaging characteristics of patients who underwent resection of newly diagnosed PFM between 2003 and 2014 in our medical center to identify covariates that significantly affected postoperative complications. RESULTS:Of 917 patients with brain metastases, 88 patients underwent surgery for PFM and were included in the study. Craniectomy was performed in 54 cases (61%). Urgent postoperative posterior fossa decompression or cerebrospinal fluid diversion was performed in 4 patients (4.5%). Postoperative complications included postoperative central nervous system infection (n = 10 [12%]), cerebrospinal fluid leak (n = 3 [4%]), wound dehiscence (n = 6 [7%]), and long-term pseudomeningocele (n = 12 [14%]). The perioperative mortality rate was 2.3% (n = 2). Multivariate analysis that included patient baseline characteristics, imaging study parameters, and surgical approaches demonstrated that suboccipital craniectomy was associated with more postoperative complications (P = 0.03, odds ratio = 4.48, 95% confidence interval = 1.14-17.6). There was no correlation between patient baseline characteristics or surgical technique with the need for urgent postoperative posterior fossa decompression or cerebrospinal fluid diversion. CONCLUSIONS:Suboccipital craniotomy may be associated with a lower incidence of postoperative morbidity compared with suboccipital craniectomy and should be considered as the preferred approach for the resection of PFM.

Superiorly projecting (SP) anterior communicating artery (AComA) aneurysms are typically described as a homogenous group. Clinically and microsurgically, these aneurysms vary in multiple important characteristics. We propose a microsurgical classification system for these complex aneurysms and review its implications regarding presentation, microsurgical techniques, and outcome. This retrospective analysis reviews patients undergoing clipping of SP AComA aneurysms (2005-2013). The classification system is based on the virtual plane created by the A2 segments and its relationship to the aneurysm. Aneurysm type was assessed by intraoperative images and videos. Type 1 is defined by bisection of the dome by the virtual plane. Type 2 is defined by dome projection posterior to this plane. Sagittal rotation of the plane defines type 3. We analyzed clinical presentation, morphology, angiographic characteristics, operative technique, and outcome relative to the classification types. There were 44 SP AComA aneurysms. 3D angiographic images predicted classification type in 83 %. Type 1 presented more often with SAH (95.5 %, p = 0.0046). There was no statistically significant difference between the types regarding patient demographics or aneurysm characteristics. In type 2, fenestrated clips were used frequently (87.5 % p= 0.0016), and there was higher rate of intraoperative rupture (37.5 %). Although there was no statistically significant difference between the types in respect to HH grade upon presentation, patients with type 2 aneurysms experienced higher rates of poor GOS (50 %). The proposed classification system for SP AComA aneurysms has implications regarding surgical planning, micro-dissection, clipping, and outcome. Type 2 aneurysms carry significant surgical risk.

BACKGROUND: The use of minimally porous endoluminal devices (MPEDs) such as the Pipeline Embolization Device (PED) has been described for the treatment of brain aneurysms. The benefit of using MPEDs to assist embolization of a direct high-flow carotid cavernous fistula resulting from a ruptured cavernous carotid artery aneurysm is not well documented. METHODS: We describe our experience with deploying a tailored multidevice PED construct across the cavernous internal carotid artery (ICA) wall defect in combination with transarterial coil embolization using the "jailed microcatheter" technique. RESULTS: A 59-year-old woman presented with acute left-sided ophthalmoplegia. Diagnostic cerebral angiography demonstrated a ruptured giant cavernous carotid aneurysm with fistulous outflow via the ipsilateral left superior ophthalmic vein and into the pterygoid venous plexi bilaterally. Via the Marksman microcatheter, a total of three PEDs measuring 4.5 mm x 18 mm, 4.5 mm x 20 mm, and 4.75 mm x 16 mm were telescoped within the ICA across the aneurysm neck. Coiling of the aneurysm fundus and cavernous sinus via the "jailed" Rapidtransit microcatheter was subsequently achieved. A 2-year follow-up digital subtraction angiography (DSA) demonstrated stable obliteration of the aneurysm and the fistula, coincident with complete resolution of the patient's symptoms. CONCLUSIONS: Based on our long-term clinical and angiographic results, we advocate that the presented method be a valid treatment option for selected cases.

Intracranial tumors may rapidly enlarge during pregnancy. When the tumor abuts the optic apparatus, tumor growth may cause visual deterioration. The decisions regarding the management of these tumors should take into consideration visual function, fetal and maternal safety, and the ability for total resection of the tumor. The objective of the study was to describe our experience and to establish principles for management of intracranial tumors compressing the optic apparatus that present during pregnancy or in the early post partum period. A retrospective case-series review was conducted. Women who presented with visual deterioration either during pregnancy or in the early post partum period due to an intracranial tumor were included. Neurosurgical and obstetrical data were collected from the patients' hospital files and outpatient clinic records. Between 2005 and 2011, nine pregnant women with visual deterioration were diagnosed and treated. Of them, four underwent a neurosurgical procedure during pregnancy. Of the five patients who underwent surgery for tumor resection after delivery, three required urgent cesarean section either due to acute visual deterioration or obstetrical reasons. There was no maternal or fetal mortality and a good overall neonatal outcome was achieved. Improvement in visual acuity and visual fields was achieved in all patients. Postoperative complications included two cases of CSF leak, which resolved after treatment. Visual deterioration during pregnancy due to tumors that compress the optic apparatus requires treatment by a multi-disciplinary team. Surgery is well tolerated by mother and fetus during early and midpregnancy; thus, in cases where visual deterioration is detected, delay of surgery is not justified.

BACKGROUND: Treatment of selected wide-neck internal carotid artery (ICA) bifurcation aneurysms remains challenging for clip reconstruction and for endovascular options. OBJECTIVE: To describe a new endovascular treatment technique for wide-neck ICA bifurcation (ICAb) aneurysms. METHODS: We have employed a treatment approach that uses both complete proximal occlusion and reversal of flow in the ipsilateral A1 segment, using different endovascular modalities such as coils, stent-assisted coiling, or flow diverters (FDs) plus coiling concomitantly. This endovascular technique may overcome the challenges of current treatments and high recanalization rates for coiled ICAb aneurysms. RESULTS: We treated four patients in whom we redirected the pre-existing flow in the supraclinoid ICA into the ipsilateral A1 and M1 segments, to a new unilateral, linear flow from the supraclinoid ICA solely into the ipsilateral M1 segment. This resulted in the establishment of flow from the contralateral A1 segment into the ipsilateral A1 segment, allowing supply of only demanding perforating arteries on this specific (ipsilateral) segment. This technique was not associated with any new neurological deficits or radiographic ischemia. The four patients reviewed were all treated using coils. One was treated with a standard stent. The other two were treated with a FD. CONCLUSIONS: We found that the proposed technique of flow modification can allow for hemodynamic conversion of ICAb to 'side-wall' aneurysm. In patients with good collateral flow through the anterior communicating complex, this treatment paradigm is safe and effective.

OBJECT The use of the Pipeline Embolization Device (PED) as a sole endovascular modality has been described for the treatment of brain aneurysms. The benefit of using coils concurrently with a limited number of PEDs is not well documented. The authors describe their experience with this technique as well as their midterm clinical and angiographic results. METHODS This is a retrospective review of patients treated between 2011 and 2014. The authors placed a minimal number of PEDs with the addition of coils using a "jailed" microcatheter technique. A partially dense coil mass was obtained. Immediate and midterm clinical and angiographic results are reviewed. RESULTS The authors treated 27 patients harboring 28 aneurysms using this technique. The mean aneurysm size was 11.9 mm, and the mean neck size was 5.4 mm. A mean of 1.48 PEDs were placed per patient, and a mean of 1.33 PEDs per aneurysm were placed. The Raymond score immediately after PED placement was 2 or 3 in 82.1% of the patients. There were no intraprocedural or postprocedural complications. All PEDs were successfully deployed. No clinical or technical adverse effects related to the coil mass were observed. There were no clinical or radiographic signs of ischemia in this group. At follow-up imaging, complete aneurysm occlusion was demonstrated on the first MR angiogram (3-5 months) in all patients who reached this milestone. Follow-up digital subtraction angiography (5-13 months) confirmed complete occlusion in all patients who reached this milestone. All patients maintained their baseline clinical status. CONCLUSIONS The deployment of PEDs with concurrent partially dense coiling is safe and efficacious. This technique achieved early complete occlusion and endovascular reconstruction of the parent vessel, without inducing mass effect. Favorable midterm clinical results were observed in all patients.

The differential diagnosis of a brain lesion with two discordant pathology reports includes the presence of collision tumor, metaplastic changes, and labeling errors that occurred during the processing of the specimen. The authors present a case in which the first brain biopsy from a 47-year-old patient with a history of heavy smoking was compatible with metastatic small cell carcinoma, and the second biopsy taken during decompression craniotomy 3 weeks later was compatible with WHO Grade IV glioblastoma. Using short tandem repeat (STR) analysis of the two specimens and nontumor-derived patient DNA, the authors found that the two specimens did not belong to the same individual. The authors conclude that allele imbalance or loss of heterozygosity detected by STR analysis is a reliable and valuable diagnostic tool for clarifying discrepancies in discordant pathology reports.