Extended transoral approaches: surgical technique and analysis. Neurosurgery
ABSTRACT The transoral approach provides the most direct exposure to extradural lesions of the ventral craniovertebral junction. Lesions that extend beyond the exposure provided by the standard transoral approach require an extended transoral modification. The exposure can be expanded in the sagittal and axial planes by adding mandibulotomy, mandibuloglossotomy, palatotomy, and transmaxillary approaches to the standard transoral approach. Extended transoral approaches increase the surgical complexity and the risk of cosmetic and functional complications. Until recently, selection of an extended approach has been arbitrary and dependent on the surgeon's familiarity with the surgical approach.
We review the literature of extended transoral approaches and analyze the different modifications in terms of the technical aspects, added exposure, and complications.
Classic approaches and recently published morphometric studies that objectively document the gain in exposure provided by several modifications were analyzed and tabulated to outline the limits of exposure and risk of complications associated with the various modifications.
Transmaxillary approaches expand the exposure to include the sphenoid sinus and upper lateral clivus. To expand the exposure more inferiorly to C4-C5, mandibulotomy or mandibuloglossotomy can be applied. Mandibuloglossotomy increases the rostral exposure as well to the upper third of the clivus. Palatotomy increases rostral exposure without requiring a facial incision or perioperative tracheostomy, but is associated with a significant risk of velopharyngeal insufficiency.
Surgical decisions can be based on comprehensive preoperative evaluation of anatomy, pathology, and radiographic studies to maximize exposure while minimizing complications.
- [Show abstract] [Hide abstract]
ABSTRACT: An optimal power and bandwidth allocation problem is considered for multi-rate frequency-division multiplexing (FDM) and frequency-division multiple-access (FDMA) over overloaded channels. We have derived the optimum frequency-division system that minimizes the total transmitted power subject to the QoS of users defined in terms of the transmission rates and the SINR requirements. The necessary and sufficient condition is found for the admissibility of the users, and the optimum power, bandwidth, transmit waveform, and receive waveform are found for each user. It is shown that the optimum frequency-division system performs exactly the same as the optimum CDMA system when all the users have the same transmission rate and channel gain. It is also shown that the optimum frequency-division system always outperforms the ETSC-minimizing code-division system when all the overloading users have the same transmission rate.Global Telecommunications Conference, 2004. GLOBECOM '04. IEEE; 01/2004
- [Show abstract] [Hide abstract]
ABSTRACT: The transoral transpharyngeal surgical approach is a recognized technique for management of ventral lesions at the clivus and upper cervical spine. This report examines the use of neuronavigation and intraoperative magnetic resonance imaging as surgical adjuncts for lesions in this region. A retrospective review of patients undergoing transoral transpharyngeal surgery in the intraoperative magnetic resonance imaging (iMRI) unit from 1997 to present was performed. Preoperative demographic data, clinical history, physical examination, and imaging studies were reviewed. Data were collected on surgical approach, pathology, postoperative management, and adverse events. Twenty patients underwent resection of ventral lesions at the craniovertebral junction through a transoral approach in the iMRI suite. Mean age at time of surgery was 50 years. A variety of pathologies were identified including neoplasms (n=7), congenital anomalies (n=7), and degenerative disease (n=6). Intraoperative imaging and neuronavigation allowed for tailoring of the surgical approach in each of our patients: 11 patients underwent transoral surgery without a palatal split or mandibulotomy; 9 patients underwent a palatal split and of these, 5 required a mandibulotomy. Interdissection images allowed for immediate confirmation of gross total resection in all cases. Postoperatively, patients were managed in the intensive care unit for an average of 7 days. Ninety-two percent of patients had neurological improvement at a mean of 1.8 years of follow-up (range 0.4-6 years). Two patients died from tumor progression and one died from renal failure. Intraoperative MRI and neuronavigation are valuable adjuncts that allow selective surgical exposure and confirmation of surgical objectives within the narrow surgical corridor provided by a transoral approach to the craniovertebral junction.World Neurosurgery 11/2011; 78(1-2):164-9. DOI:10.1016/j.wneu.2011.09.020 · 2.42 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: STUDY DESIGN:: A retrospective study of consecutive patient series. OBJECTIVES:: To report a technique of odontoidectomy using a transoccipitocervical posterolateral approach for occipitoatlantoaxial ventral lesions in a long-term follow-up study. SUMMARY OF BACKGROUND DATA:: Occipitoatlantoaxial malformation and old traumatic dislocation usually cause compression of the high cervical spinal cord from a variety of different directions and angles, leading to high morbidity. The main objective of treatment is to relieve the anteroposterior compression and to restore the stability of the occipitocervical region. Currently, there are 2 approaches to perform the surgical procedure: (1) posterior decompression by suboccipital and occipitocervical fusion and internal fixation; and (2) decompression by a transoral approach to an odontoid resection. However, there are some short points, which need to be changed, such as the incomplete decompression (the former), narrow view, cerebrospinal fluid leakage, and the high infection rates. METHODS:: From 1999 to 2006, 23 patients with occipitoatlantoaxial ventral lesions were treated using a transoccipitocervical posterolateral approach for decompression. The procedure included an expansion of the foramen magnum, a resection of the posterior arch of atlas, a lateral occipitocervical epidural exposure to the odontoid and the C2 vertebra, and an excision of the odontoid. Thus, an anteroposterior decompression and occipitocervical spinal fusion was achieved. Neurological function, daily living ability, and the work ability of patients were assessed in a follow-up study. RESULTS:: A 28-year-old woman died of respiratory and circulatory failure 10 hours after operation. The remaining patients survived without postoperative infection. The neurological injury in 17 patients did not deteriorate, whereas 5 patients had decreased sensation in the upper limbs, and the elbow flexor muscle strength in 2 patients declined by 1 grade on the operation side. Short-term follow-up (3-6 mo, 22 cases) indicated that 19 patients recovered normal sensation with decreased limb muscle tension. Motor function was improved by >1 grade (5 patients with postoperative nerve injury recovered to preoperative levels or better). Long-term follow-up (>4 y) of 15 patients (10 patients by clinic visit and 5 patients by correspondence) indicated that the occipitoatlantoaxial regions were stable without local discomfort or loss of nerve function. Fourteen patients were able to care for themselves and some patients regained their ability to work. One patient felt no significant improvement after surgery and had no improvement in the quality of life. CONCLUSIONS:: Transoccipitocervical posterolateral approach to occipitoatlantoaxial ventral lesions provides a broad and sterile operating field to perform anteroposterior decompression and occipitocervical spinal fusion simultaneously. Neurological improvement is significant, and the long-term follow-up results are satisfactory.Journal of spinal disorders & techniques 12/2011; DOI:10.1097/BSD.0b013e31823faec4 · 1.89 Impact Factor