Faculty Bibliography

Aneurysms of the anterior cerebral artery (ACA) located distal to the anterior communicating artery complex (ACOM) remain challenging to treat with surgical clip reconstruction as well as with endovascular coil-embolization strategies. We have treated five complex geometry distal ACA aneurysms with endoluminal reconstruction using the Pipeline Embolization Device (PED). Two aneurysms were of the dysplastic fusiform type. Three aneurysms were of complex saccular configuration. Three aneurysms were treated electively at the outset with PED. One patient had previously undergone aborted clip reconstruction, and one was treated for recurrent aneurysm growth after coil embolization. The mean diameter of the ACA in this cohort was 1.96mm proximal to the aneurysm and 1.79mm distal to the aneurysmal segment. A single PED of 2.5mm inner diameter was the sole treatment in four cases. Two PEDs, telescopically overlapped across the aneurysm, were used in the remaining case. All devices were deployed successfully. No parent artery occlusion or stenosis was observed. In all cases an associated branch vessel arising from the vicinity of the aneurysm or incorporated into its neck was covered by the endoluminal construct. At follow-up angiography, robust antegrade flow was maintained in the jailed branch. One patient experienced asymptomatic, delayed occlusion of the jailed branch. Complete aneurysm occlusion was seen in all patients. We confirm that PED can be deployed in parent vessels smaller than 2mm diameter, and that endoluminal reconstruction with the PED may be a safe and effective treatment alternative for selected distal ACA aneurysms.

BACKGROUND:In the past, microsurgical bypass was the best option for revascularization of cerebrovascular lesions that required flow replacement or flow augmentation. Over the last 2 decades with advancements in the field of neuroendovascular surgery, especially with the revolution of flow diverting stents as well as the results of the Carotid Occlusion Surgery Study, indications for microvascular bypass have significantly decreased. The purpose of this study was to evaluate trends in cerebral revascularization over the past 8 years. METHODS:We retrospectively reviewed patients with cerebral revascularization surgery during the years 2006-2014 in a single surgeon's practice. All patients who had undergone cerebral revascularization for any indication were included in the study. RESULTS:We identified 106 patients who had undergone cerebral bypass; 2 patients were excluded. Of 104 patients, 60% were female and 40% were male. Indications for surgery were giant aneurysm in 48 patients, arterial occlusion in 30 patients, and moyamoya disease in 26 patients. In all indications except for moyamoya disease, case number per year declined. A marked decrease was noted in revascularization for treatment of giant aneurysm or occlusion. CONCLUSIONS:This study demonstrates the impact that both scientific inquiry and technologic advances have had on a challenging and valuable technique in cerebrovascular surgery. Indications for both flow replacement and augmentative bypass remain. However, the marked decline in indications may have an indelible impact on maintenance of surgical proficiency as well as the ability for young neurosurgeons to develop this valuable skill set.

BACKGROUND:The cervical carotid system has been used as a source of donor vessels for radial artery or saphenous vein grafts in cerebral bypass. Recently, internal maxillary artery to middle cerebral artery bypass has been described as an alternative, with reduction of graft length potentially correlating with improved patency. OBJECTIVE:To describe our experience using the forearm cephalic vein grafts for short segment internal maxillary artery to middle cerebral artery bypasses. METHODS:All vein grafts were harvested from the volar forearm between the proximal cubital fossa where the median cubital vein is confluent with the cephalic vein and the distal wrist. RESULTS:Six patients were treated with internal maxillary artery to middle cerebral artery bypass. In 4, the cephalic vein was used. Postoperative angiography demonstrated good filling of the grafts with robust distal flow. There were no upper extremity vascular complications. All but 1 patient (mortality) tolerated the procedure well. The other 3 patients returned to their neurological baseline with no new neurological deficit during follow-up. CONCLUSION/CONCLUSIONS:The internal maxillary artery to middle cerebral artery "middle" flow bypass allows for shorter graft length with both the proximal and distal anastomoses within the same microsurgical field. These unique variable flow grafts represent an ideal opportunity for use of the cephalic vein of the forearm, which is more easily harvested than the wider saphenous vein graft and which has good match size to the M1/M2 segments of the middle cerebral artery. The vessel wall is supple, which facilitates handling during anastomosis. There is lower morbidity potential than utilization of the radial artery. Going forward, the cephalic vein will be our preferred choice for external carotid-internal carotid transplanted conduit bypass.

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.