Dissecting Fusiform PICA Aneurysm Repair With Trapping and an Unconventional End-to-Side Reanastomosis: 2-Dimensional Operative Video

Dissecting fusiform posterior inferior cerebellar artery (PICA) aneurysms are rare and challenging.1,2 One common treatment is occlusion of the aneurysm and parent artery via an endovascular approach without revascularization.3 Revascularization of the artery requires an open microsurgical bypass or endovascular placement of a newer-generation flow diverter.4 We present an end-to-side reanastomosis of the PICA for treatment of a dissecting fusiform left PICA aneurysm with anatomy deemed unfavorable for endovascular treatment in a 62-yr-old man with subarachnoid hemorrhage. After discussions regarding risks, benefits, and alternatives to the procedure, the family consented to surgical treatment.  A far-lateral craniotomy was performed, with partial condylectomy to widen the exposure. The cisterna magna was opened, and the dentate ligament was cut to visualize the vertebral artery. The PICA was identified and traced distally to the aneurysmal segment, which was circumferentially diseased. Perforators were noted immediately distal to the aneurysm. The aneurysm was then trapped, and the afferent artery was transected and brought to the sidewall of the distal artery. The recipient site was trapped with temporary clips, and a linear arteriotomy was made. An end-to-side reanastomosis was performed, temporary clips were removed, and hemostasis was achieved. Postoperative angiography confirmed bypass patency and preservation of the PICA perforators.  Conventional reanastomosis of the parent artery after aneurysm excision is achieved by end-to-end reanastomosis. In contrast, we performed an unconventional end-to-side reanastomosis to revascularize the PICA while leaving the efferent artery in situ to protect its medullary perforators. This bypass is an example of a fourth-generation bypass.5,6 Used with permission from the Barrow Neurological Institute, Phoenix, Arizona

The middle communicating artery: a novel fourth-generation bypass for revascularizing trapped middle cerebral artery bifurcation aneurysms in 2 cases

The anterior and posterior communicating arteries are natural connections between arteries that enable different adjacent circulations to redistribute blood flow instantly in response to changing supply and demand. An analogous communication does not exist in the middle cerebral circulation. A middle communicating artery (MCoA) can be created microsurgically between separate middle cerebral artery (MCA) trunks, enabling flow to redistribute in response to changing supply and demand. The MCoA would draw blood flow from an adjacent circulation such as the external carotid circulation. The MCoA requires the application of fourth-generation techniques to reconstruct bi- and trifurcations after occluding complex MCA trunk aneurysms. In this report, the authors describe two recent cases of complex MCA bi- and trifurcation aneurysms in which the occluded efferent trunks were revascularized by creating an MCoA. The first MCoA was created with a “double-barrel” superficial temporal artery-M2 segment bypass and end-to-end reimplantation of the middle and inferior MCA trunks. The second MCoA was created with an external carotid artery-radial artery graft-M2 segment interpositional bypass and end-to-side reimplantation of the inferior trunk onto the superior trunk. Both aneurysms were occluded, and both patients experienced good outcomes. This report introduces the concept of the MCoA and demonstrates two variations. Angioarchitectural and technical elements include the donation of flow from an adjacent circulation, a communicating bypass, the application of fourth-generation bypass techniques, and a minimized ischemia time. The MCoA construct is ideally suited for rebuilding bi- and trifurcated anatomy after trapping or distally occluding complex MCA aneurysms

The middle communicating artery: A novel fourth-generation bypass for revascularizing trapped middle cerebral artery bifurcation aneurysms in 2 cases

The anterior and posterior communicating arteries are natural connections between arteries that enable different adjacent circulations to redistribute blood flow instantly in response to changing supply and demand. An analogous communication does not exist in the middle cerebral circulation. A middle communicating artery (MCoA) can be created microsurgically between separate middle cerebral artery (MCA) trunks, enabling flow to redistribute in response to changing supply and demand. The MCoA would draw blood flow from an adjacent circulation such as the external carotid circulation. The MCoA requires the application of fourth-generation techniques to reconstruct bi- and trifurcations after occluding complex MCA trunk aneurysms. In this report, the authors describe two recent cases of complex MCA bi- and trifurcation aneurysms in which the occluded efferent trunks were revascularized by creating an MCoA. The first MCoA was created with a “double-barrel” superficial temporal artery-M2 segment bypass and end-to-end reimplantation of the middle and inferior MCA trunks. The second MCoA was created with an external carotid artery-radial artery graft-M2 segment interpositional bypass and end-to-side reimplantation of the inferior trunk onto the superior trunk. Both aneurysms were occluded, and both patients experienced good outcomes. This report introduces the concept of the MCoA and demonstrates two variations. Angioarchitectural and technical elements include the donation of flow from an adjacent circulation, a communicating bypass, the application of fourth-generation bypass techniques, and a minimized ischemia time. The MCoA construct is ideally suited for rebuilding bi- and trifurcated anatomy after trapping or distally occluding complex MCA aneurysms

Microsurgical Management of a Marginal Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video

Dural arteriovenous fistulas (DAVFs) are benign but may present with life-threatening hemorrhage or symptoms of venous hypertension (eg, progressive myelopathy).1-3 DAVFs follow well-described anatomic patterns.4 The marginal sinus is located between the layers of the dura, circumferentially around the foramen magnum. It communicates with the basal venous plexus of the clivus anteriorly and the occipital sinus posteriorly.5,6 Arterial supply to the dura in this region that fistulizes into the sinus arises from meningeal branches from the V3 or V4 segments.  A man in his early 70s presented with chronic neck pain and new onset of left arm and face paresthesias. He had brisk patellar reflexes bilaterally and a marginal sinus DAVF, with numerous dilated veins around the cisterna magna, causing dorsal cervicomedullary compression. Angiography confirmed the diagnosis of DAVF rather than arteriovenous malformation. Endovascular embolization was considered, but surgery was preferable because of poor transarterial access.  The patient underwent left far lateral craniotomy and C1 laminectomy with exposure of the condylar fossa. The dura was carefully elevated laterally, revealing a network of dilated tortuous veins, with multiple points of fistulous connection within the dura emanating in a large venous varix. Indocyanine green videoangiography showed the aberrant flow dynamics. The fistulous point was occluded with aneurysm clips on the venous side, then cauterized and interrupted. The patient was discharged within 3 d of surgery and had full resolution of symptoms at 6 wk. Angiography confirmed complete obliteration of the DAVF. The patient provided written informed consent for treatment. Used with permission from Barrow Neurological Institute, Phoenix, Arizona

Long-Term Independence in Older Patients with Aneurysmal Subarachnoid Hemorrhage in the Barrow Ruptured Aneurysm Trial

Objective: Older patients have a higher risk for poor neurological outcomes following aneurysmal subarachnoid hemorrhage (aSAH). This study compared functional independence in older versus younger patients with aSAH and compared endovascular coiling with microsurgical clipping in the older cohort. Methods: Patients enrolled in the Barrow Ruptured Aneurysm Trial (BRAT) with confirmed aSAH were analyzed. Patients were grouped by age: older (≥65 years old) or younger (\u3c65 years old). The primary outcome analyzed was functional independence at long-term follow-up, defined as Barthel index \u3e80 at 6-year follow-up. A second analysis was performed comparing functional independence in older patients treated with endovascular coiling versus microsurgical clipping. Results: Of 405 patients with aSAH enrolled in BRAT, 77 (19%) were ≥65 years old, and 328 (81%) were \u3c65 years old. A lower percentage of older versus younger patients was functionally independent (Barthel index \u3e80) at 6-year follow-up (42.0% [29/69] vs. 82.2% [217/264]; P \u3c 0.001). A higher percentage of younger patients (69.7% [184/264]) had good neurological outcomes (modified Rankin Scale score \u3c3) at 6-year follow-up compared with older patients (31.9% [22/69]; P \u3c 0.001). A greater percentage of older patients treated with microsurgical clipping (51.0% [18/47]) versus endovascular coiling (22.7% [5/22]) had functional independence at 6-year follow-up (P \u3c 0.04). Conclusions: Patients ≥65 years old with aSAH are at increased risk for poor neurological outcomes compared with younger patients. Greater independence was observed in older patients after microsurgical clipping than after endovascular coiling at long-term follow-up

Endoscopic Third Ventriculostomy Prior to Resection of Posterior Fossa Tumors in Children

OBJECTIVE: Hydrocephalus is a common presenting symptom of pediatric posterior fossa tumors and often requires permanent cerebrospinal fluid diversion even after resection. Endoscopic third ventriculostomy (ETV) is a well-established treatment of obstructive hydrocephalus in children. The objective of this study is to demonstrate that ETV prior to posterior fossa tumor resection decreases the rate of postoperative ventriculoperitonal shunt (VPS) placement. METHODS: We performed a retrospective analysis of patients who presented with hydrocephalus and underwent posterior fossa tumor resection between 2005 and 2016 excluding pineal and tectal tumors. The rate of postoperative VPS placement was compared in patients who underwent resection and had a VPS placed perioperatively (historical controls) with patients who underwent ETV prior to resection. The two groups were matched for demographics, tumor histology, and tumor location. We also performed a literature review of prior studies that examined the role of ETV in pediatric posterior fossa tumors. RESULTS: Thirty-six patients in the control group were compared to 38 patients in our study. The patients were matched across all variables (age, gender, tumor histology, and tumor locations). The rate of postoperative VPS placement was 31% in the control group compared to 16% in the ETV group. No complications were encountered during ETV. CONCLUSIONS: Endoscopic third ventriculostomy prior to posterior fossa tumor resection in children appears to decrease the rate of postoperative VPS placement. Given its efficacy and safety, ETV should be considered prior to tumor resection in these patients