Anterior Transoral Approach Research Articles

Upper cervical spine instability due to pyogenic infection successfully treated by one stage posterior debridement and stabilization: Case Report and literature review

Pyogenic osteomyelitis of the upper cervical spine is a rare condition associated with different clinical symptoms and signs. Previous studies have stressed the difficulties in making the diagnosis due to its unusual location and relatively rare occurrence. We hereby describe a case of a 65-year-old man with pyogenic infection of the craniocervical junction up to the axis with severe instability managed by posterior fusion from occiput to C6, an open biopsy from C1–C2 lesions and irrigation and debridement. On follow-up visit at two years, our patient had recovered completely. We present this case to show that the posterior approach without the anterior transoral approach is a valid surgical option in such cases. Additionally, we emphasize the importance of stabilization to successfully treat spine osteomyelitis and summarize the literature available discussing upper cervical spine infection treatment options.

Osteoplastic Anterior Transoral Approach for Tumors of the Middle Cranial Fossa.

Surgical access to tumors involving the midline skull base remains a considerable challenge for surgeons. Various surgical approaches for treating these tumors like transnasal, transantral, and endoscopic approaches sometimes have anatomical limitations. This paper describes a transoral approach with a Lefort I osteotomy that allows a great visualization, not only to the center of the skull base but also the infratemporal fossa. This technique may be used for the surgical resection of extracranial and intracranial benign tumors, and non-neoplastic intradural pathology, which does not require dural resection. The authors will review proper patient selection, surgical exposure, operative procedure, and complications.

Odontoidectomy through posterior midline approach followed by same sitting occipitocervical fixation: A cadaveric study.

Object:Atlantoaxial instability with irreducible odontoid process is one of the challenges in spine surgery. These lesions are commonly treated through anterior transoral approach which is followed by posterior atlantoaxial fusion. However, there are still many limitations, especially cerebrospinal fluid fistula with subsequent life-threatening infection, difficulty in cases with limited opening of mouth due to temporomandibular arthritis or anomalies of naso-oropharynx. Türe et al. used the extreme lateral transatlas approach for the removal of odontoid. In this study, we applied the transatlas approach but through posterior midline incision aiming to evaluate its safety and feasibility.Methods:In four silicon injected, formalin-fixed cadaver heads, posterior removal of the odontoid was done through the familiar midline incision and subperiosteal muscle separation and elevation of muscles as on unit followed by microscopic exposure and mobilization of the vertebral artery after opening of the foramen transversarium of atlas followed by drilling of lateral mass and odontoidectomy. Occipitocervical stabilization was done between the occiput and C2, C3 (C1 lateral mass screw can be added in the contralateral side for better stabilization).Results:Unilateral excision of the lateral mass of atlas after mobilization of the vertebral artery provided safe and excellent exposure of the odontoid process in the four cadaver heads without injury to vertebral artery or retraction of the dura.Conclusion:Posterior removal of the odontoid can be done safely through wide and sterile operative field, and occipitocervical fixation performed at the same sitting without need for another operation and hence avoids the risk of cord injury from repositioning.

Clinical and Radiographic Outcomes of C1 Laminectomy Without Fusion in Patients With Cervical Myelopathy That Is Associated With a Retro-odontoid Pseudotumor.

A retro-odontoid pseudotumor that is not associated with rheumatoid arthritis or hemodialysis is clinically rare. The majority of surgeons select transoral resection as the surgical treatment, often followed by posterior fusion or posterior decompression and fusion. In contrast, some authors have reported success with simple decompression without posterior stabilization in cases where atlanto-axial instability (AAI) is either absent or minor. In this study, we have evaluated the clinical and radiographic outcomes of C1 laminectomy without fusion as the surgical treatment for patients with cervical myelopathy that is associated with a retro-odontoid pseudotumor. A retrospective chart review was conducted on 10 patients who underwent C1 laminectomy without fusion for cervical myelopathy associated with a retro-odontoid pseudotumor. The average follow-up time was 29 months. All cases were graded as Ranawat grade 3a or 3b. After surgery, myelopathy improved in all of the patients. In 2 patients, the atlas-dens interval increased in the flexed position; however, this did not result in any clinical problems. The size of the retro-odontoid mass (measured on magnetic resonance images at least 12 mo after surgery) decreased in 4 of the 10 cases. AAI progression and mass enlargement were our primary concerns for this surgical option; however, C1 laminectomy did not cause severe AAI progression, no patients showed serious mass enlargement, and all patients demonstrated neurological improvement. This surgical strategy is beneficial especially for elderly patients given the risks of other surgical options that use an anterior transoral approach or posterior fusion.

Retro-odontoid mass without atlantoaxial instability causing cervical myelopathy: a case report of transdural surgical resection.

Retro-odontoid mass rarely occur in patients with noninflammatory retro-odontoid lesions without atlantoaxial instability. We describe a rare case of retro-odontoid mass without atlantoaxial instability operated on by a transdural approach. The patient was an 83-year-old man who presented with a retro-odontoid mass causing symptomatic cervical myelopathy. Preoperative magnetic resonance imaging (MRI) revealed that the mass was severely compressing the spinal cord. We operated on it via a C1 laminectomy and performed tumor resection by a transdural approach. Pathological findings from the operative specimen confirmed the diagnosis; histopathological examination revealed that the mass contained fibrinoid material, and collagenous tissue with myxoid changes, but no granulation or a granulomatous lesion. Postoperative MRI confirmed spinal cord decompression. The patient's symptoms were alleviated, and he has not had a recurrence or cervical instability in the 7 years since his surgery. We successfully used a transdural approach in the present case and have observed no recurrence for 7 years postoperatively. C1 laminectomy is reportedly beneficial, especially for elderly patients, given the risk of other surgical options using an anterior transoral approach or posterior fusion. However, most tumors do not attenuate after C1 laminectomy alone; hence, we think that tumor resection by the transdural approach is one effective method to perform enucleation of the tumor after C1 laminectomy.

Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors.

Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations. The posterior extradural approach is the most common; however, it remains challenging due to severe epidural veins. Although regression of pseudotumors after fusion surgery has been reported, direct decompression and a pathologic diagnosis are ideal when the pseudotumor is large. We therefore developed a new microscopic surgical technique; transdural resection. After C1 laminectomy, the dorsal and ventral dura was incised while preserving the arachnoid. Removal of the pseudotumor was performed and both of the dura were repaired. The patient’s clinical symptoms subsequently improved and the pathologic findings showed degenerative fibrocartilaginous tissue. In addition, no neurological deterioration, central spinal fluid leakage, or arachnoiditis was observed. Currently, the usefulness of the transdural approach has been reported for cervical and thoracic disk herniation. According to our results, the transdural approach is recommended for resection of retro-odontoid pseudotumors because it enables direct decompression of the spinal cord and a pathologic diagnosis.

Transoral anterior release, odontoid partial resection, and reduction with posterior fusion for the treatment of irreducible atlantoaxial dislocation caused by odontoid fracture malunion.

Several techniques have been introduced to manage irreducible atlantoaxial dislocation (IAAD). However, no study has reported the surgical method for the management of IAAD caused by odontoid fracture malunion. This study aimed to introduce a surgical method of transoral anterior release, odontoid partial resection, and reduction with sequential posterior fusion for the treatment of IAAD caused by odontoid fracture malunion. We also evaluated the clinical efficacy of this surgery. This study included seven cases of IAAD caused by odontoid fracture malunion, collected from January 2008 to January 2011. Anterior atlantoaxial release was performed through anterior transoral approach, followed by partial resection of the odontoid process. C1-C2 were then fixed through pedicle screws and rods, and then fused posteriorly by single stage. Neurologic status was evaluated using the Japanese Orthopaedic Association (JOA) scoring system. All seven patients had complete release, and satisfactory reduction. Bony fusion was seen in all patients postoperatively. The patients were followed up for an average of 19.6 months (ranged from 9 to 36 months). The average of patients JOA scores at the final follow-up was significantly higher than that of their preoperative scores. Furthermore, the average improvement in neurological function was 87.4 %. No screw loosening, implant migration or implant failures, atlantoaxial redislocation, or signs of instability were observed in any of the patients during the follow-up period. Transoral anterior release, odontoid partial resection, and reduction combined with posterior fusion are effective, reliable, and safe procedures for the treatment of IAAD caused by odontoid fracture malunion.

Cranio-Spinal Junction Tumours: Role of Transoral Approach Followed by Stereotactic Radiotherapy

Cranio-spinal junction tumors are usually approached through posterior, postero-lateral and far lateral approaches but, in case of prevalently anterior extension, with posterior and postero-lateral displacement of brainstem, anterior transoral approach should be considered to achieve a satisfactory tumor removal. Anterior transoral approach allows a direct exposition of the tumor without necessity of nervous/vascular structures manipulation. Postoperative instability is not frequent, and usually posterior stabilization is rarely required. Although transoral approach allows removing only the median part of the tumor’s and in few cases radical removal can be performed, it presents an extremely low rate of new neurological deficit and a rapid resumption of vital activities. Postoperative tumor remnant can be treated, in our experience, with hypofractionated stereotactic radiotherapy with very satisfactory results concerning tumor regrow and recurrence. We believe that in the modern era its capital to deal with this extremely challenging tumor’s with a different goal: to achieve the maximal clinical result, not the maximal surgical resection at all costs.

ОПЫТ ХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ ОПУХОЛЕЙ КРАНИОВЕРТЕБРАЛЬНОГО ПЕРЕХОДА

Objective. To analyze clinical results of surgical treatment of patients with craniocervical junction tumors. Material and Methods. A total of 47 patients with tumors of the craniocervical junction were operated on. There were 8 (17,0 %) intramedullar and 39 (83,0 %) extramedullar tumors, including 5 dumbbell tumors. Tumors were located anteriorly in 6 (12,7 %), anterolaterally in 10 (21,3 %), laterally in 14 (29,8 %), posterolaterally in 7 (14,9 %) and posteriorly in 10 (21,3 %) patients. Meningiomas were diagnosed in 25 (53,2 %), neurinomas in 10 (21,3 %), astrocytomas in 4 (8,5 %), ependymomas - in 3 (6,4 %), hordomas in 4 (8,5 %), and hemangioblastomas in 1 (2,1 %) patient. Removal of 4 (8,5 %) tumors located at the clivus level was performed via anterior transoral approach. The remaining patients were operated on using posterior and posterolateral approaches in 36 (51,1 %) and far-lateral approach in 7 (14,9 %) cases. Results. Total removal of the tumor was achieved in 86,0 % of cases. Tumors in 7 (14,0 %) patients were removed subtotally due to their hard-to-reach location and large size. Conclusion. Total removal of craniocervical junction tumors through posterolateral (far-lateral) approach is possible not only in cases of their posterolateral or lateral location, but also of anterior one. The method of choice for removal of clivus tumors is transoral approach.

Screw placement in transoral atlantoaxial plate systems: an anatomical study.

The placement of an anterior atlantoaxial plate after transoral odontoid resection has been described by Harms. Recently, the authors of biomechanical and clinical studies have shown that this procedure, especially in combination with posterior wiring, is a good alternative to established, isolated posterior atlantoaxial fixation techniques. Reports on the anatomy of the atlas and axis primarily focus on the posterior surgical approach. Scarce research regarding the quantitative anatomy of the anterior aspect of C-1 and C-2 has been reported. This study was undertaken to measure relevant dimensions of C-1 and C-2 and their relation to the anterior transoral approach. The aim of the study was to determine "safe zones" for screw placement in anterior atlantoaxial plate fixation. Fifty human dry C-1 and C-2 vertebrae were obtained for direct anatomical, radiographic, and computerized tomography (CT) measurements. Thirty-two linear and four angular parameters were evaluated. All measurements were made using a digital caliper, ruler, or goniometer. Anatomical measurements were correlated with radiographic (anteroposterior, lateral, and craniocaudal) and CT (0.5-mm-slice thickness) measurements of the corresponding vertebrae. Additionally, bone mineral density (BMD) measurements of C-1 and C-2 were obtained in 20 patients. A safe zone for anterior screw placement in an atlas of bilateral trapezoid shape could be characterized. The average medial and lateral height of the trapezoid was 4.1 +/- 1.01 mm (range 1.4-6.7 mm) and 12.9 +/- 1.73 mm (range 8.7-17.4 mm), respectively. The distance between the sagittal plane and the medial and lateral walls of the trapezoid was 10.2 +/- 1.42 mm (range 8.9-12.8 mm) and 23.5 +/- 2.98 mm (range 21.7-30.7 mm), respectively. The average depth of the lateral masses was 22.3 +/- 2.04 mm (range 17.0-26.7 mm) in the sagittal plane. The average BMD in the safe zone of C-1 was 0.89 +/- 0.11 g/cm3 (range 0.75-1.01 g/cm3). Bone mineral density measurements at C-2 revealed a spheroid zone of low density at the basis of the dens (0.68 +/- 0.09 g/cm3). In contrast, high zones of BMD were found near the articular surfaces (C1-2: 0.97 +/- 0.11 g/cm3; C2-3: 0.94 +/- 0.12 g/cm3). The safe zone for anterior axis screw placement was V-shaped, limited cranially by a zone of low bone density and laterally by the vertebral artery groove. Correlations between radiographic and anatomical measurements were generally good (r2 = 0.78-0.95), but they were higher between CT and anatomical measurements (r2 = 0.86-0.99). A quantitative understanding of the anterior anatomy of C-1 and C-2 is necessary when considering anterior atlantoaxial plate fixation after transoral odontoid resection. In this study the authors defined safe zones for anterior atlas and axis screw placement. The anterior atlantoaxial plate, as originally described by Harms, only partially respects these safe zones.

<I>Surgical Approaches to Foramen Magnum Meningioma</I>

Although foramen magnum meningiomas are usually removable, their location poses considerable surgical risk. The authors present three cases of foramen magnum meningioma. The first involved a ventral type tumor extending to the second cervical body. Following bilateral mandibulotomy, surgery was performed via the anterior transoral approach and the tumor was totally removed. Nine days postoperatively, she developed meningitis, which was successfully treated with antibiotics. The second patient's tumor was dorsal type and was deeply embedded in the lateral part of the vermis. The tumor was totally removed via the midline suboccipital approach and she recovered uneventfully, with only slight upper-extremity paresthesia. In the third case, the tumor was ventral type and situated mainly in the clivus. Craniotomy was performed by the bilateral suboccipital approach and extended nearly to the jugular tubercle. The tumor, which severely displaced the lower cranial and upper cervical nerves, was totally removed. The postoperative course was lengthy and complicated. Artificial ventilation was required for 2 months, and difficulty in swallowing persisted during long-term follow-up. As illustrated by the second case, dorsal and lateral type foramen magnum meningiomas can usually be removed via the lateral suboccipital approach. In the case of ventral type tumors, the anterior transoral approach entails the risk of infection, as occurred in the first case. The authors conclude that the lateral suboccipital approach is preferable; craniotomy extending to the jugular tubercle lowers the risk of brainstem damage.