Micromirrors in Neurosurgery: Technical Overview and Benefits Assessment.

AIM: To weight the benefits and limitations of intraoperative use of micromirrors in neurosurgery. MATERIAL AND METHODS: Surgical cases where micromirrors were employed were retrospectively selected from the surgical database of five different surgeons in different hospitals. Complications directly attributable to the micromirrors were assessed intraoperatively and confirmed with postoperative neuroimaging studies. RESULTS: Fourteen patients were selected. The site of the lesion was as follows: posterior fossa (43%), frontal lobe (22%), temporal lobe (14%), parietal lobe (7%), insula (7%), and basal ganglia (7%). Five tumors (35%) were gliomas, 3 (21%) epidermoid, and 3 (21 %) supratentorial metastases. Two patients underwent microvascular decompression for neurovascular conflict, and 1 harbored a brain arteriovenous malformation. A gross total resection was achieved in all the tumors and the AVM, while an effective decompression was successfully performed in both patients with conflict. No complications directly attributable to the use of the micromirror occurred. A relatively easy learning curve was noted. CONCLUSION: Micromirrors proved to be useful in enhancing the visualization of neurovascular structures and pathology residuals within deep-seated surgical fields without the need for fixed brain retraction. Their cost-effectiveness and easy learning curve constitute solid reasons for advocating a revitalization of this ?old but gold? tool in neurosurgery.

Awake craniotomy removal of a corticospinal tract developmental venous anomaly hemorrhage: A case report.

Developmental venous anomalies (DVAs) are composed of mature venous vessels that lack malformed or neoplastic elements. Although the hemorrhage risk is considered negligible, some patients may have neurological symptoms attributable to acute infarction or intracranial hemorrhage secondary to thrombosis, in the absence of a coexisting cavernous malformation. We report the case of a 42-year-old patient who presented with acute left-hand paresis secondary to a subcortical hemorrhage. This bleeding originated from a DVA in the corticospinal tract area and was surgically drained through an awake craniotomy. To accomplish this, we used a trans-precentral sulcus approach. After the complete removal of the coagulum, small venous channels appeared, which were coagulated. No associated cavernoma was found. Although the main DVA trunk was left patent, no signs of ischemia or venous infarction were observed after coagulating the small venous channels found inside the hematoma cavity. Two weeks after the procedure, the patient's hand function improved, and he was able to resume desktop work. DVA-associated hemorrhage within the cortico-spinal tract could be safely removed with modern awake mapping techniques. This technique allowed the patient to rapidly improve his hand function.

Use of Saito technique to resect an anterior lumbar spine meningioma: Technical note.

BACKGROUND: Complete (Simpson Grade I: total removal) resections for anterior spinal meningiomas are especially challenging. This is largely attributed to difficulty obtaining a water-tight dural repair where the tumor has infiltrated the dura requiring duroplasty, thus often resulting in just a Simpson Grade II resection (i.e. coagulation of the dural implantation site). Here, we present a 56-year-old female who underwent resection of a ventral lumbar meningioma utilizing the Saito technique, that effectively separated the dura into two layers, removing just the inner layer but leaving the outer layer intact for direct dural repair. METHODS: A 56-year-old female underwent a L1-L2 laminectomy. The anterior intradural resection of tumor was achieved with the Saito technique; this required cutting circumferentially around the tumor insertion site, and removing only the inner layer. RESULTS: Postoperatively, the patient did well without tumor recurrence over 8 years. The postoperative biopsy confirmed a World Health Organization Grade I meningothelial meningioma. CONCLUSION: Saito's technique proved to be a safe and effective method for achieving gross total resection of an anterior lumbar meningioma.

Optic Nerve Mobilization as an Alternative to Anterior Clinoidectomy for Superior Carotid-Ophthalmic Aneurysms: Operative Technique.

BACKGROUND: Carotid-ophthalmic aneurysms arise from the internal carotid artery between the distal dural ring and the origin of the posterior communicating artery. The surgical treatment of these aneurysms usually requires anterior clinoidectomy. However, this procedure is not without complications. In the present report, we have described optic nerve mobilization after optic foraminotomy as an alternative to anterior clinoidectomy to clip superior carotid-ophthalmic aneurysms. METHODS: We have reported the cases of 3 patients with superior carotid-ophthalmic aneurysms who had undergone surgical clipping. Instead of an anterior clinoidectomy, the optic nerve was mobilized after performing optic foraminotomy. The optic canal was carefully unroofed with a 3-mm, high-speed, diamond drill under constant cold saline irrigation to avoid thermal damage to the optic nerve. After incision of the falciform ligament and optic sheath, the optic nerve was gently mobilized with a No. 6 Penfield dissector, facilitating aneurysmal neck exposure and clipping through a widened opticocarotid triangle. RESULTS: The postoperative course was uneventful for all 3 patients, without any added visual defect. Optic nerve mobilization allowed us to safely widen the opticocarotid triangle and dissect the aneurysm off the optic nerve, without the need for clinoidectomy. This alternative technique permitted, not only early decompression of the optic nerve, but also dissection of the arachnoid between the inferior surface of the optic nerve and the superior surface of the ophthalmic-carotid artery and aneurysm dome. CONCLUSIONS: Optic nerve mobilization after optic foraminotomy proved to be a safe and relatively easy technique for exposing and treating superior carotid-ophthalmic aneurysms.

Unilateral C1 split fracture osteosynthesis using a patient-specific three-dimensional-printed guide: Technique report.

Split-type C1 lateral mass fractures have a propensity for progressive fracture displacement. Since almost all cases end up showing progressive fragment diastasis, many authors recommend early surgical treatment. However, placing a C1 lag screw through a C1 split fracture is a challenging task. To overcome this, we designed a patient-custom three-dimensional (3D)-printed guide plate. We present the case of a 57-year-old female patient with a C1 lateral mass split fracture. Considering the amount of fragment translation, primary osteosynthesis was proposed. To purchase both fragments, placement of a lag screw was assisted intraoperatively by a custom 3D-printed composite guide plate, which enabled us to accurately place the screw. After an uneventful procedure, the patient was discharged from hospital after 72 h. Computed tomography scan performed at 12 months showed good fracture consolidation. The use of a patient-specific guide to place a lag screw through a split fracture of the atlas proved to be a safe, accurate, and inexpensive alternative to intraoperative imaging integrated with image-guided surgery.

An alternative path to atrial lesions through a contralateral interhemispheric transfalcine transcingular infra-precuneus approach: A case report.

BACKGROUND: The surgical management of lesions located in the trigone of the lateral ventricle remains a neurosurgical challenge. Previously described approaches to the atrium include the transtemporal, parietal transcortical, parietal trans intraparietal sulcus, occipital transcingulate, posterior transcallosal, and transfalcine transprecuneus. However, reaching this area specifically through the cingulate cortex below the subparietal sulcus has not been described thus far. CASE DESCRIPTION: We present here the removal of a left atrial meningioma through a right parietal "contralateral interhemispheric transfalcine transcingular infra-precuneus" approach and compare it with previously described midline approaches to the atrium. To accomplish this, a right parietal craniotomy was performed. After the left subprecuneus cingulate cortex was exposed through a window in the falx, a limited corticotomy was performed, which allowed the tumor to be reached after deepening the bipolar dissection by 8 mm. Postoperative magnetic resonance imaging showed complete resection of the lesion sparing the corpus callosum, forceps major, and sagittal stratum. Although this approach disrupts the posterior cingulate fasciculus, no deficits have been described so far after unilaterally disrupting the posterior cingulate cortex or the posterior part of the cingulate fasciculus. In fact, a thorough postoperative cognitive examination did not show any deficits. CONCLUSION: The "contralateral interhemispheric transfalcine transcingular infra-precuneus" approach combines the advantages of several previously described approaches. Since it conserves the major white matter tracts that surround the atrium and has a shorter attack angle than the contralateral transfalcine transprecuneus approach, we believe that it could be a potentially new alternative path to reach atrial lesions.

A novel temporary cranial fixation device for awake cranial surgery: Technical report of 14 cases.

BACKGROUND: Awake craniotomy has become the gold standard in various cranial procedures. As part of the awake technique, three-point pin fixation of the patient's head is important. One of the issues we encountered is the problem of matching the scalp infiltration site with the final pin position. To overcome this problem, we developed a flat plunger type fixator that adapts to the Mayfield holder. METHODS: Our fixator has a 2.5 cm metallic shaft that articulates in a ball and socket joint to allow its concave surfaces to adapt to the patient's scalp. After placing the patient in the desired position, the head is fixed with the three plungers, circles are drawn around each plunger, and they are then removed for the circles to be infiltrated with bupivacaine. Standard fixation pins are then placed in the Mayfield holder and aimed at the center of the circles. RESULTS: So far, we have operated on 14 patients with this technique. No patient experienced pain during temporary fixation, and the drawn circles ensured that there were no mismatches between the local anesthetic and pin locations. The technique was particularly useful on hairy scalps, where infiltration sites were hidden. We also used only 22.5 mg bupivacaine at the pin sites, freeing a dose for the field block around the scalp incision. CONCLUSION: The temporary plunger type fixator provided a simple method to economize on local anesthetic use, check the patient's head position before final fixation, and ensure that the Mayfield pins matched with the anesthetized area.

Anatomía quirúrgica en 3D de las osteotomías vertebrales cervicales / 3D surgical anatomy of cervical vertebral osteotomies

Objetivo: realizar osteotomías cervicales en preparados cadavéricos, siguiendo la clasificación moderna de 7 grados según Ames y colaboradores, tomando fotos 3D para poner en evidencia la magnitud de resección ósea de cada uno de los subtipos. Material y Métodos: Se utilizaron dos preparados cadavéricos formolizados con inyección vascular, realizándose imágenes fotográficas en 3 dimensiones de los mismos. Las fotografías fueron tomadas con una camara Nikon D90, con lente 50 mm Af 1.8G, flash Nikon SB700, y una barra regulable para fotografía. Se realizó sobre las preparaciones cadavéricas la disección cervical con incisión en línea media posterior y abordaje por vía anterior segun Smith y Robinson. Se efectuó la exposición muscular y esquelitización ósea con exposición de láminas, apófisis espinosas, facetas articulares, ligamentos, discos, apófisis unciformes y cuerpos vertebrales. Mediante la utilización de un drill neumático de alta velocidad se realizaron 8 osteotomías, 4 por vía posterior y 4 por vía anterior. Resultados: Las osteotomías realizadas por vía anterior fueron la discectomía anterior completa (denominada osteotomía grado I anterior), la corpectomía parcial o total incluyendo discectomía superior e inferior (denominada osteotomía grado III), la resección completa de la unión uncovertebral o articulación de Luschka (denominada osteotomía grado IV) y la resección vertebral completa o espondilectomía (denominada osteotomía grado VII). Por vía posterior, se realizaron la facetectomía parcial (denominada osteotomía grado I posterior), la facetectomía total u osteotomía de Ponte (denominada osteotomía grado II), la osteotomía de apertura angular (denominada osteotomía grado V) y la osteotomía de cierre angular o de sustracción pedicular (denominada osteotomía grado VI). Las imágenes fotográficas obtenidas fueron procesadas con los siguientes softwares con técnica anaglífica: Anaglyph Maker versión 1.08 y StereoPhoto Maker versión 4.54...

Objective: to perform cervical osteotomies in cadaveric specimens, following the new classification of Ames et al. 3D pictures were taken to show the amount of bone resection on each subtype. Material & methods: Using two formolized cadaveric specimens with vascular injection, we took 3D pictures of osteotomies following the Ames et al classification of cervical osteotomies. The pictures were taken with a Nikon D90 camera, with a 50 mm lens Af 1.8G, Nikon SB700 flash, and an adjustable titanium frame designed to take 3D pictures. Anterior cadaveric dissections were made based on the Smith & Robinson technique. We also performed a posterior approach to expose laminar surfaces, spinous processes, facets complexes, ligaments, discs, uncovertebral joints and vertebral bodies. With the aid of a pneumatic drill, 8 osteotomies (4 anterior and 4 posterior) were progressively made and pictured. Results: The anterior osteotomies were: discectomy, corpectomy, discectomy with uncovertebral resection and spondilectomy. Posterior osteotomies were: partial facetectomy, complete facetectomy (Ponte), open wedge osteotomy and closing wedge osteotomy (pedicle substraction). Pictures were processed and fused with Anaglyph Maker 1.08 and StereoPhoto Maker 4.54...

One-stage open reduction of an old cervical subluxation: case report.

Study Design Case report. Objective The recommended treatment of cervical subluxation is currently closed or open reduction. These treatments are better accomplished in the acute setting, when muscular and ligamentous laxity allows the required maneuvers to realign the dislocated segments. However, subsets of patients are still being treated subacutely. The majority of the literature addressing subacute subluxations reports treatment through "front and back" approaches, many of them performed in two, three, or even four stages. Other authors recommend days or weeks of traction to reduce the subluxation, followed by anterior or posterior approaches. Herein, we present a one-stage open posterior surgical treatment of a 2-month standing C5-C6 subluxation with "jumped facets," describing a useful technique to reduce these challenging cases without the need of traction or multistage procedures. Methods After opening and exposing the posterior elements, we performed a wide C5-6 bilateral foraminotomy; we then put lateral mass screws and rods from C4 to C6. Resembling the technique used in the reduction of high-grade lumbar spondylolisthesis, we used a rod reducer to bring back the C5 screw head toward the rod, thus realigning the lateral mass screw heads and reducing the subluxation. Results No changes were observed in the motor evoked or somatosensory potentials during this maneuver. Following an uneventful procedure, the patient was transferred to the postanesthetic care unit and discharged 3 days later. Conclusions This open single-stage posterior approach dramatically reduces operating time. This technique could be added into the decision-making armamentarium for cases without disk herniation.

Subependimoma sintomático del piso del IV ventrículo: reporte de un caso y revisión de la literatura / Simptomatic subependimoma of IV ventricle

Objetivo: reportar un caso de esta infrecuente patología y realizar una revisión bibliográfica, analizando sus características clínicas y morbimortalidad. Descripción: presentamos aquí el caso de un paciente de 64 años, el cual consulta sobre un síndrome vertiginoso de un año de evolución. En la IRM se observaba una lesión ocupante de espacio en el cuarto ventrículo, la cual media 5,3 x 4,1 x 4,2 cm. No se observaba franca hidrocefalia a pesar del tamaño de la misma. Intervención: se efectuó una craniectomía suboccipital con laminectomía C1. El tumor nacía francamente del piso del IV ventrículo. Se resecó la lesión en forma completa, efectuando cavitación y disección roma entre la cápsula y el piso IV ventrículo. El paciente tuvo un postoperatorio tórpido dada la paresia de pares bajos que presentó durante las primeras semanas, por lo que fue intubado, traqueostomizado y alimentado por sonda nasoyeyunal. Al 5º mes de postoperatorio el paciente se hallaba independiente para sus actividades de la vida diaria. La resonancia postoperatoria evidenciaba la exéresis completa de la lesión. Conclusión: los subependimomas que nacen del piso del IV ventrículo tienen una elevada morbimortalidad documentada. Sólo la minuciosa disección con microscopio y cuidados intensivos postoperatorios pueden mejorar este pronóstico...