Anterior perforated substance region aneurysms: review of a series treated with microsurgical technique.

Aneurysms arising from the distal carotid, proximal A1, and proximal M1 that project posteriorly and superiorly toward the anterior perforated substance (APS) are rare. Their open surgical treatment is particularly difficult due to poorly visualized origin of the aneurysm and the abundance of surrounding perforators. We sought to analyze the anatomical and clinical characteristics of APS aneurysms and discuss surgical nuances that can optimize visualization, complete neck clip obliteration, and preservation of adjacent perforators. Thirty-two patients with 36 APS aneurysms were surgically treated between November 2000 and September 2017. Patients were prospectively enrolled in a cerebral aneurysm database and their clinical, imaging, and surgical records were retrospectively reviewed. Twenty-seven aneurysms originated from the distal ICA, 7 from the proximal A1, and 2 from the proximal M1; 15 patients presented with subarachnoid hemorrhage. Careful intraoperative dissection revealed 4 aneurysms originating at the takeoff of a perforator; another 25 had at least 1 adherent perforator. All aneurysms were clipped except for one that was trapped. Postoperatively, 3 patients had radiographic infarctions in perforator territory with only 1 developing delayed clinical hemiparesis. Good outcome (modified Rankin Scale, 0-2) was achieved in 28 patients (88%). APS aneurysms present a challenging subset of aneurysms due to their complex anatomical relationship with surrounding perforators. These should be identified on preoperative imaging based on location and projection. Successful microsurgical clipping relies on optimization of the surgical view, meticulous clip reconstruction, preservation of all perforators, and electrophysiological monitoring to minimize ischemic complication.

Clinical outcomes of unstable thoracolumbar junction burst fractures: combined posterior short-segment correction followed by thoracoscopic corpectomy and fusion.

BACKGROUND: There is significant controversy surrounding the ideal management of thoracolumbar burst fractures. While several treatment and management algorithms have been proposed, the ideal treatment strategy for these fractures remains unsettled. The authors review their experience with short-segment posterior fusion followed by anterior thoracoscopic corpectomy for the treatment of unstable thoracolumbar burst fractures. METHODS: We identified all patients treated by a single surgeon at our institution from 2002 to 2009 with short-segment posterior fusion followed by anterior thoracoscopic corpectomy for unstable thoracolumbar junction burst fractures. Demographic data, mechanism of injury, classification of fracture, Cobb angle, American Spinal Injury Association score, associated injuries, tobacco use, follow-up duration, and radiographic studies were all collected. Outcomes were assessed for fracture alignment (preoperative, postoperative, and long-term follow-up kyphosis), rate of fusion, neurological outcome, and treatment complications. RESULTS: Thirty-two patients with burst fracture of the thoracolumbar junction defined as T10 to L1 were included. At a mean follow-up of 20.4 months, 90 % of patients had demonstrated radiographic evidence of fusion and 91 % retained the correction of their kyphotic deformity. There were three complications in the series. CONCLUSIONS: Short-segment posterior fusion with thoracoscopic anterior corpectomy represents an alternative to traditional open treatment of thoracolumbar burst fractures. A thoracoscopic approach allows for a short-segment posterior fusion, reducing the loss of adjacent motion segments, minimizes morbidity associated with traditional open anterior approaches, allows for anterior and posterior column stabilization, and is associated with a high rate of bony fusion.

Incidental meningiomas.

With the increasing availability and use of modern brain diagnostic imaging modalities, discovery of incidental meningiomas has become fairly common. This creates a dilemma among neurosurgeons as to whether these lesions should be treated. Numerous natural history studies have been published in an effort to shed light on the potential for growth of incidental meningiomas. The available data appear to suggest that these tumors can fall into 1 of 3 main growth patterns: no growth, linear growth, or exponential growth. The therapeutic strategy selected should also consider several other factors, mainly the risk of complications from an eventual surgery, the possibility of malignancies and other pathological conditions that mimic meningiomas, and the age and medical condition of the patient. The authors believe that most asymptomatic incidental meningiomas can be observed using serial imaging and clinical follow-up evaluations. Surgical interventions are typically reserved for large, symptomatic lesions and those with documented potential for significant growth.

Management considerations and strategies to avoid complications associated with the thoracoscopic approach for corpectomy.

The thoracoscopic approach to the anterior spine is a practical and valuable means of approaching ventral spinal lesions but demands advanced technical skills and fine hand-eye coordination that is usually acquired with experience. A mutual understanding of all the ventilatory and surgical steps allows for an organized orchestration between the anesthesiologist and surgeon, which ultimately helps minimize potential complications. Despite a concerted effort by all involved to avoid risks, thoracoscopic surgery is associated with complications for which the surgical team should be cognizant. In this paper, the authors detail the operative technique of vertebral corpectomy and interbody fusion via the thoracoscopic approach for the treatment of ventral spinal pathology involving the thoracic and lower lumbar spine, discuss complications known to occur with the thoracoscopic approach, and present means to help avoid them.

Resection of an Isolated Pituitary Stalk Epidermoid Cyst Through a Pretemporal Approach: Case Report and Review of the Literature.

BACKGROUND: Intracranial epidermoid cysts are congenital epidermal inclusion cysts derived from ectodermal origin with desquamated skin. The majority of these cysts occur in the cerebellopontine angle cistern. Epidermoid cyst of the pituitary stalk, however, is a rare location. To date, only 4 previous cases have been reported. CASE DESCRIPTION: A 63-year-old male presented to our clinic with migraine headaches, dizziness, increased thirst, increased urinary frequency, and impotence. Magnetic resonance imaging of the brain demonstrated a rim-enhancing cystic mass with diffusion restriction on diffusion-weighted imaging located within the pituitary stalk. The patient underwent a pretemporal approach with gross total resection of the cyst. The patient's postoperative course was uneventful with no new deficits and/or endocrinopathies. CONCLUSION: Epidermoid cyst of the pituitary stalk is an unusual and rare presentation. Four other cases treated via endoscopic approaches have been previously reported in the neurosurgical literature. To our knowledge this is the first case description of an infundibular epidermoid cyst pressing with isolated diabetes insipidus surgically treated via a transcranial pretemporal approach with gross total resection. The patient had a smooth and uneventful postoperative course with persistent diabetes insipidus.

Autologous Temporalis Subfascial Fat Graft for Skull Base Repair: A Novel Technique.

BACKGROUND: Autologous abdominal fat grafts are occasionally used in the repair of skull base exposures. This surgical procedure typically requires an additional surgical site and may have unexpected postoperative complications. OBJECTIVE: To describe an operative technique for harvesting subfascial fat from the temporal extension of the buccal fat pad for the repair of skull base defects. METHODS: We review the pertinent anatomy of the temporalis subfascial fat pad and discuss the technique used to harvest the subfascial fat component in a clinical presentation. RESULTS: A pretemporal approach was performed for clip ligation of an anterior circulation aneurysm. A standard frontotemporal incision was made with an interfascial flap to preserve the frontalis branches of the facial nerve. The subfascial fat was inspected and determined to be adequate for harvesting. Monopolar cauterization was carefully utilized to remove the fat. During closure, the graft was used to repair a pneumatized clinoid sinus and for the dural repair of the pretemporal exposure. The patient did not have any postoperative complications. CONCLUSION: Autologous temporalis subfascial fat graft is a viable and safe technique for skull base dural and sinus repair during frontotemporal approaches in select patients. This technique avoids an additional surgical procedure and potential complications that may be associated with it.

Continuous Interrupted Double Throw Suturing Method: A Novel Suturing Technique for Extracranial-Intracranial Bypass.

OBJECTIVE: Despite failure of the EC/IC Bypass Study Group to demonstrate effectiveness in minimizing future stroke events, superior temporal artery-medial cerebral artery (STA-MCA) bypass remains an essential treatment for complex giant intracranial aneurysms, tumors, moyamoya disease with ischemia, and atherosclerotic steno-occlusive disease with hemodynamic cerebrovascular insufficiency. The objective of this report is to describe a novel suturing technique for STA-MCA bypass that helps reduce donor-recipient anastomosis time, allowing for a well-organized systematic workflow. METHODS: Step 1 involves passing the needle of a 9-0 polypropylene suture from out-to-in on the donor vessel followed by in-to-out on the recipient vessel. Step 2: Before cutting and tying a knot as per the established method of suturing, repeat step 1 and leave the needle "parked", creating a loop that is then cut at its proximal end. Step 3: Tie knots using the jeweler's forceps. Repeat previous steps until there are enough throws to seal the bypass adequately. RESULTS: The STA-MCA bypass serves as a principal method for flow augmentation. The technique described here allows for more efficient and organized microsurgical movements reducing vessel tissue manipulation and clamp time. CONCLUSIONS: We describe a novel technique for interrupted STA-MCA bypass suturing that adds efficiency, safety, organization, and operative ease compared with the conventional method of interrupted vessel suturing.

Temporary Clipping of the Intracavernous Internal Carotid Artery: A Novel Technique for Proximal Control.

BACKGROUND: Securing proximal control in complex paraclinoid aneurysm surgery through traditional techniques may be challenging and risky in certain situations. Advancements of anatomical knowledge of the cavernous sinus (CS) and hemostasis have made it more accessible as a surgical option. OBJECTIVE: To describe the technique of temporary clipping of the horizontal segment of the intracavernous internal carotid artery (IC-ICA) in preparation for permanent clipping of complex paraclinoid aneurysms. METHODS: Through an extradural pretemporal approach, the lateral wall of the CS is exposed. The dura between the trochlear nerve and V1 is opened, and access is made to the horizontal segment of the IC-ICA. After circumferential dissection, the temporary clip can be introduced to the artery, and the extradural clinoidectomy can be continued under secured proximal control. RESULTS: Seven patients with complex paraclinoid aneurysms were treated between May 2013 and May 2016 by the senior author. Temporary clipping of the IC-ICA was performed in all cases. Average time to achieve proximal control was 22.6 min (22.6 ± 13.8). One patient developed transient oculomotor palsy postoperatively. There were no other complications. CONCLUSION: When the exposed clinoidal segment of the internal carotid artery does not offer sufficient proximal space for temporary clipping, the extradural approach can be extended to the horizontal portion of the IC-ICA. In our experience, this technique is a quick, reliable, and safe alternative to the classical modalities of temporary occlusion.

The pathogenetic features of cerebral cavernous malformations: a comprehensive review with therapeutic implications.

Cerebral cavernous malformations (CCMs) are common vascular lesions of the CNS that may lead to seizures, focal neurological deficits, and fatal hemorrhagic stroke. Human genetic studies have identified 3 genes associated with CCM, and biochemical and molecular studies in mice have elucidated signaling pathways with important therapeutic implications. In this review, the authors shed light on the 3 discovered CCM genes as well as their protein products, with particular emphasis on their signal transduction pathways and their interaction with one another. Close focus is directed at mice model studies involving the Ccm2 gene product signaling pathway, revealing an important role for the use of simvastatin or other RhoA inhibitors as a therapeutic modality in the treatment of CCM. The remaining challenges to creating a more faithful CCM animal model as well as future clinical and research implications are reviewed.

Morphometric Comparison of the Pterional Trans-Sylvian and the Pretemporal Trans-Clinoidal Approaches to the Posterior Communicating Artery.

BACKGROUND: Posterior communicating (Pcom) aneurysms in the modern era have tended toward increased complexity and technical difficulties. The pretemporal approach is a valuable extension to the pterional approach for basilar apex aneurysms, but its advantages for Pcom aneurysms have not been previously elucidated. OBJECTIVE: To quantify characteristics of the pretemporal approach to the Pcom. METHODS: We dissected 6 cadaveric heads (12 sides) with a pretemporal transclinoidal approach and measured the following variables: (1) exposed length of internal carotid artery (ICA) proximal to the Pcom artery; (2) exposed circumference of ICA at the origin of Pcom; (3) deep working area between the optic nerve and tentorium/oculomotor nerve; (4) superficial working area; (5) exposure depth; and (6) the frontotemporal (superior posterolateral) and (7) orbito-sphenoidal (inferior anterolateral) angles of exposure. RESULTS: Compared with pterional craniotomy, the pretemporal transclinoidal approach increased the exposed length of the proximal ICA from 3.3 to 11.7 mm (P = .0001) and its circumference from 5.1 to 7.8 mm (P = .0003), allowing a 210° view of the ICA (vs 137.9°). The deep and superficial working areas also significantly widened from 53.7 to 92.4 mm2 (P = .0048) and 252.8 to 418.2 mm2 (P = .0001), respectively; the depth of the exposure was equivalent. The frontotemporal and spheno-Sylvian angles increased by 17° (P = .0006) and 10° (P = .0037), respectively. CONCLUSION: The pretemporal approach can be useful for complex Pcom aneurysms by providing easier proximal control, wider working space, improved aneurysm visualization, and more versatile clipping angles. Enhanced exposure results in a potentially higher rate of complete aneurysm obliteration and complication avoidance.

Cranio-Orbital and Orbitocranial Approaches to Orbital and Intracranial Disease: Eye-Opening Approaches for Neurosurgeons.

Orbital approaches for targeting intracranial, orbital, and infratemporal disease have evolved over the years in an effort to discover safe, reliable, effective, and cosmetically satisfying surgical corridors. The surgical goals of these approaches balance important factors such as proximity of the lesion to the optic nerve, the degree of anticipated manipulation and required space for surgical maneuverability, and the type of disease. The authors provide a comprehensive review of the most commonly used periorbital approaches in the management of intra- and extracranial disease, with emphasis on the advantages and limitations of each approach.

Rapid M1 Hemoclips Arteriotomy Repair After Emergency Coil Embolectomy.

BACKGROUND: The vascular closure staple clips have been studied in animal models and shown to have comparable results with sutured repair when it comes to the healing process, degree of vessel narrowing, and risk of thrombosis. However, they are clearly superior when the speed of application is taken into account, and they were clinically used in many vascular repair processes. Nevertheless, their usefulness in intracranial vascular surgery has not been described. OBJECTIVE: To describe the usefulness of hemoclips in fast and efficient repair of medium-sized and large intracranial vessels. METHODS: Two female patients diagnosed with giant symptomatic cavernous sinus aneurysms were undergoing elective endovascular procedures that were complicated by the dislodgement of coils into the M1 segment of the middle cerebral artery. Both patients were treated performing M1 arteriotomies and coil embolectomy. To avoid prolonged temporary occlusion in the M1 perforator's territory, the arteriotomies were repaired using microhemoclips in less than 10 min with re-establishment of flow. RESULTS: In both patients, flow was re-established in the M1 segments. In 1 patient, the coils extended to the temporal M2 causing intimal injury and leading to diminished flow. M1 segments in both patients were patent on later angiographic studies. CONCLUSION: We describe the advantage of emergent cerebrovascular arteriotomy and embolectomy in a rapid repair process that helped avoid massive ischemic injury. We believe this technique should be added to the armamentarium of neurosurgical cerebrovascular options.

Biocompatible Amniotic Sac Implant Maintains a Scar-Free Brain Surface During Recurrent Glioma Surgery.

BACKGROUND: Dissection of brain surface adhesions during recurrent glioma surgery carries a risk of injury to cortical vessels and important surface vessels. We present our experience with the use of BioD film, a biocompatible amniotic membrane implant, to help prevent postoperative adhesions. We describe a novel method for preventing postoperative adhesions after high-grade glioma surgery using BioD film. METHODS: Amniotic sac implants were laid on the brain surface after resection of gliomas located near major surface arteries (sylvian fissure) and major veins (parasagittal convexity). Seven cases involved reoperation for tumor recurrence. RESULTS: In all 7 of the cases requiring reoperation, a new arachnoid-like surface layer was formed without any dural adhesions. The newly formed layer allowed for easy and simple dissection and mobilization of surface vessels while avoiding any trauma to the cortex. CONCLUSIONS: Amniotic sac implants have a promising role in preventing most surgical brain adhesions associated with recurrent glioma surgery, reducing the risks of cortical vessel and tissue injury.

Multiple osteomas of the falx cerebri and anterior skull base: case report.

The authors describe a rare case of intracranial extraaxial parafalcine and anterior skull base osteomas in a 22-year-old woman presenting with bifrontal headaches. This case highlights the possible occurrence of such lesions along the anterior skull base and parafalcine region that, as such, should be considered as part of the differential diagnosis for extraaxial calcific lesions involving the anterior skull base. To the authors' knowledge, this is the first reported case of a patient who underwent complete successful resection of multiple extraaxial osteomas of the anterior skull base and parafalcine region.

Unusual brachial plexus lesion: Hematoma masquerading as a peripheral nerve sheath tumor.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) of the brachial plexus have unique radiographic and clinical findings. Patients often present with progressive upper extremity paresthesias, weakness, and pain. On magnetic resonance (MR) imaging, lesions are isointense on T1-weighted and hyperintense on T2-weighted sequences, while also demonstrating marked enhancement on MR studies with gadolinium diethylenetriamine pentaacetic acid. On the basis of their characteristic MR imaging features and rapid clinical progression, two brachial plexus lesions proved to be organizing hematomas rather than MPNST. METHODS: A 51-year-old male and a 31-year-old female were both assessed for persistent and worsened left-sided upper extremity pain, paresthesias, and weakness. In both cases, the MR imaging of the brachial plexus demonstrated an extraspinal enhancing lesion located within the left C7-T1 neuroforamina. RESULTS: Although the clinical and radiographic MR features for these 2 patients were consistent with MPNSTs, both lesions proved to be benign organizing hematomas. CONCLUSIONS: These two case studies emphasize that brachial plexus hematomas may mimic MPNSTs on MR studies. Accurate diagnosis of these lesions is critical for determining the appropriate management options and treatment plans. Delaying the treatment of a highly aggressive nerve sheath tumor can have devastating consequences, whereas many hematomas resolve without surgery. Therefore, if the patient has stable findings on neurological examination and a history of trauma, surgical intervention may be delayed in favor of repeat MR imaging in 2-3 months to re-evaluate the size of the mass.

Early Conquest of the Rock: Julius Lempert's Life and the Complete Apicectomy Technique for the Treatment of Suppurative Petrous Apicitis.

Julius Lempert (1891-1968) was one of the most revolutionary and innovative neuro-otologists of the 20th century. He had a remarkable role in advancing the field of otolaryngology to its modern shape and form, especially through his groundbreaking introduction of the fenestration procedure for the treatment of otosclerosis. Although he is highly celebrated by many neuro-otologists for his contributions to our surgical and anatomical understanding of the petrous bone, he is not well known to the neurosurgical community. In this article, we give a detailed account of Dr. Lempert's life and discuss his invaluable contribution to skull base petrous bone anatomy and surgery through his pioneering work on the complete apicectomy for the treatment of suppurative petrous apicitis.

Extraspinal type I dural arteriovenous fistula with a lumbosacral lipomyelomeningocele: a case report and review of the literature.

Seven cases of adult spinal vascular malformations presenting in conjunction with spinal dysraphism have been reported in the literature. Two of these involved male patients with a combined dural arteriovenous fistula (DAVF) and lipomyelomeningocele. The authors present the third case of a patient with an extraspinal DAVF and associated lipomyelomeningocele in a lumbosacral location. A 58-year-old woman with rapid decline in bilateral motor function 10 years after a prior L4-5 laminectomy and cord detethering for diagnosed tethered cord underwent magnetic resonance imaging showing evidence of persistent cord tethering and a lipomyelomeningocele. Diagnostic spinal angiogram showed a DAVF with arterial feeders from bilateral sacral and the right internal iliac arteries. The patient underwent Onyx embolization of both feeding right and left lateral sacral arteries. At 6-month follow-up, MRI revealed decreased flow voids and new collateralized supply to the DAVF. The patient underwent successful lipomyelomeningocele exploration, resection, AV fistula ligation, and cord detethering. This report discusses management of this patient as well as the importance of endovascular embolization followed by microsurgery for the treatment of cases with combined vascular and dysraphic anomalies.

Marching beyond the sella: Gerard Guiot and his contributions to neurosurgery.

Gerard Guiot (1912-1998) was one of the most renowned and innovative neurosurgeons of the 20th century. His pivotal and revolutionary role in advancing transsphenoidal surgery has been recorded in many historical vignettes, yet his outstanding contributions to the advancement of neurosurgery outside the confines of the sella have not been described in a detailed fashion. In this article, the authors discuss the life and achievements of Professor Guiot and present a comprehensive description of his contributions to the field of neurosurgery, including cerebrovascular, spine, craniofacial, stereotactic functional, and endoscopic surgery.

Giant Spontaneous Epidural Pneumatocele: Case Report and Review of the Literature.

BACKGROUND: Pneumocephalus is a commonly encountered finding in neurosurgery in which air displaces intracranial cerebrospinal fluid after cranial surgery or a cerebrospinal fluid leak into paranasal or mastoid sinuses. When an intracranial air collection becomes chronically established in a fixed loculation causing mass effect, pneumatocele is a more appropriate term. We present an unusual case of a spontaneous giant frontotemporal epidural pneumatocele that persisted for more than 1 year before the patient presented for neurological treatment. CASE DESCRIPTION: A 40-year-old man with a remote history of minor head trauma presented with symptoms of headaches, dizziness, and vertigo. Imaging revealed a right giant epidural pneumocephalus secondary to bony dehiscence of the intracranial wall of the mastoid bone. A subtemporal middle fossa approach was performed to repair the mastoid defect with hydroxyapatite, fat graft, and temporalis fascia. The patient was discharged on postoperative day 2 with improvement in his headaches. One month after discharge operative imaging demonstrated complete resolution of his epidural pneumatocele and improvement in his headaches. CONCLUSIONS: This unique case represents the first reported case in the neurosurgical literature of a giant spontaneous epidural pneumatocele occurring in an adult treated with a middle fossa approach with resolution on follow-up imaging.

Intraventricular hemorrhage after epidural blood patching: an unusual complication.

The authors present two cases of intraventricular hemorrhage (IVH) believed to be a result of epidural blood patching. The first was a 71-year-old woman who had new onset of nontraumatic IVH on computed tomography (CT) scan after undergoing an epidural blood patch (EBP). This amount of intraventricular blood was deemed an incidental finding since it was of very small volume to account for her overall symptoms. The second patient, a 29-year-old woman, was found to have nontraumatic IVH three days after undergoing an EBP. This was seen on CT scan of the head for workup of pressure-like headaches, nausea, vomiting, and absence seizures. Conservative management was followed in both instances. Serial CT scan of the head in our first patient displayed complete resolution of her IVH. The second patient did not have follow-up CT scans because her overall clinical picture had improved significantly. This highlights a potential sequel of EBP that may be observed on CT scan of the head. In the event that IVH is detected, signs and symptoms of hydrocephalus should be closely monitored with the consideration for a future workup if warranted by the clinical picture.