Experimental Endoscopic Angular Domains of Transnasal And Transoral Routes to the Craniovertebral Junction (original) (raw)
Related papers
2016
Study Design. We investigate on the surgical reliability of nasal palatine line for the transnasal approach and introduce a conceptually analogue radiological line as a reliable predictor of the maximal superior extension of the transoral approach. We have also compared radiological and surgical lines to find possible radiological references points to predict preoperatively the maximal extent of superior dissection for the transoral approach. Objective. After comparing the surgical exposition angle and the working channel volume of both the approaches in our previous article, now we compare the radiological (theoretical) with the “surgical” (effective) Nasopalatine line and the latter with the recently introduced Nasal Axial Line. We conceived a radiological line with a similar significance for the transoral approach and we called it Mandibulopalatine line; then we compared the radiological with the “surgical” one. Summary of Background Data. Endoscopy represents both an alternative...
Comparison of endoscopic transnasal and transoral approaches to the craniovertebral junction
World neurosurgery, 2010
The study compared the endoscopic anatomy of the transnasal and transoral approaches to the craniovertebral junction (CVJ). Structures examined and compared with both the straight and angled telescopes in 10 cadaveric specimens included the pharyngeal walls and adjacent musculature, resected anterior arch of the axis and odontoid, cruciform, axial, and apical ligaments, clival and dural openings, and the intradural exposure. There is considerable overlap at the pharyngeal level in the structures that can be viewed by the transoral and transnasal routes. The transoral approach provides a wider corridor with less restricted manipulation of instruments than the transnasal approach, but the transnasal approach provides a better view of the clivus, upper part of the CVJ, and the structures posterior to the removed odontoid and anterior arch of C1. Combining the two approaches provides significantly better access to the midline anterior CVJ than either approach alone, allows the scopes to...
Ultrasound in Medicine and Biology, 2010
The transoral (TO) approach to the craniocervical junction provides similar access to the periclival and subaxial spine compared with the extraoral anterolateral prevascular (EAP) approach, but the additional exposure gained by the EAP approach has not been quantified. This study quantitatively compared the two surgical exposures.Ten silicon-injected fixed cadaver heads were used for the TO approach and another 5 heads (10 sides) were dissected for the EAP approach. For the TO approach, mouth opening was standardized to 5.5 cm using a Spetzler-Sonntag retractor, and the soft palate was split 1.5 cm to access the periclival area. A frameless stereotactic device was used to calculate the lengths, angles, and areas of surgical exposure for different anatomic targets.The vertical working length on the dura progressively increased 61% (336 ± 26 mm to 539 ± 16 mm [mean ± standard deviation]; P < 0.001), and the vertical working angle increased 23% (98 ± 3 degrees to 121 ± 5 degrees; P < 0.0) using the TO versus the EAP approach. In the TO approach, the bilateral average horizontal working length on the C1 arch was less on the ipsilateral side than for the EAP approach (11 ± 1 mm vs. 17 ± 1 mm, 61%; P < 0.01). The mean periclival and subaxial exposures were 546 ± 72 mm2 and 932 ± 70 mm2 with the TO approach and 874 ± 75 mm2 and 1644 ± 107 mm2 with the EAP approach (mean increases 62% and 77%, respectively; both P < 0.001).Both the TO and EAP approaches improved surgical exposure, but the EAP approach provides more significant and consistent gains to the anterolateral periclival and subaxial areas.
The rhinopalatine line as a reliable predictor of the inferior extent of endonasal odontoidectomies
Neurosurgical focus, 2015
OBJECT The endoscopic endonasal approach (EEA) provides a minimally invasive corridor through which the cervicomedullary junction can be decompressed with reduced morbidity rates compared to those with the classic transoral approaches. The limit of the EEA is its inferior extent, and preoperative estimation of its reach is vital for determining its suitability. The aim of this study was to evaluate the actual inferior limit of the EEA in a surgical series of patients and develop an accurate and reliable predictor that can be used in planning endonasal odontoidectomies. METHODS The actual inferior extent of surgery was determined in a series of 6 patients with adequate preoperative and postoperative imaging who underwent endoscopie endonasal odontoidectomy. The medians of the differences between several previously described predictive lines, namely the nasopalatine line (NPL) and nasoaxial line (NAxL), were compared with the actual surgical limit and the hard-palate line by using non...
Skull base : official journal of North American Skull Base Society ... [et al.], 2011
The objective of this study is to determine the bony limits of the transnasal and transoral approaches to the anterior skull base. The data we present are meant to assist surgeons in preoperative planning for lesions of the sella, clivus, foramen magnum, and odontoid. Using precise measurements undertaken on 41 high-resolution computed tomography scans from patients at the University of Pennsylvania without any history of sinus or sellar pathology, we sought to define the bony limits of transoral and transnasal approaches. Direct measurements and calculated angles were used to assess the dimensions of the anterior skull base. Using our measurements, a transnasal approach can reach an average of 22.5 mm below the plane of the hard palate to the body of C2, and a transoral route can reach 38 mm above the basion along the length of the clivus. Analysis of variance demonstrated no significant differences when subjects were grouped based on race or gender. The measurements outlined withi...
World neurosurgery, 2017
Transnasal approach to lesions involving the craniovertebral junction represents a technical challenge because of limited inferior exposure. The authors describe the endoscopic transseptal approach (ETsA) with posterior nasal spine (PNS) removal; this technique can create a wide exposition of the craniovertebral junction increasing the caudal exposure. On patients undergoing anterior craniovertebral junction decompression, we calculated the degree of exposure on the sagittal plan through a paraseptal route, an ETsA without and with PNS removal. The horizontal exposure and working area with the latter approach were evaluated too. Five patients underwent the aforementioned transnasal procedure. The age of patients ranged from 34 to 71 year-old. All patients harbored basilar impression. The mean post-operatve Nurick grade (1,8) was improved over the average pre-operative grade (3). The average follow-up duration was 16 months. All patients underwent occipito-cervical fixation. The mean...
Transoral approach to the craniovertebral junction
Arquivos de Neuro-Psiquiatria, 2007
The transoral approach provides a safe exposure to lesions in the midline and the ventral side of the craniovertebral junction. The advantages of the transoral approach are 1) the impinging bony pathology and granulation tissue are accessible only via the ventral route; 2) the head is placed in the extended position, thus decreasing the angulation of the brainstem during the surgery; and 3) surgery is done through the avascular median pharyngeal raphe and clivus. We analyzed the clinical effects of odontoidectomy after treating 38 patients with basilar invagination. The anterior transoral operation to treat irreducible ventral compression in patients with basilar invagination was performed in 38 patients. The patients' ages ranged from 34 to 67 years. Fourteen patients had associated Chiari malformation and eight had previously undergone posterior decompressive surgery. The main indication for surgery was significant neurological deterioration. Symptoms and signs included neck pain, myelopathy, lower cranial nerve dysfunction, nystagmus and gait disturbance. Extended exposure was performed in 24 patients. The surgery was beneficial to the majority of patients. There was one death within 10 days of surgery, due to pulmonary embolism. Postoperative complications included two cases of pneumonia, three cases of oronasal fistula with regurgitation and one cerebrospinal fluid leak. In patients with marked ventral compression, the transoral approach provides direct access to the anterior face of the craniovertebral junction and effective means for odontoidectomy.
International Journal of Oral and Maxillofacial Surgery, 2017
Objectives: A cephalometric analysis especially designed for the patient who requires maxillofacial surgery was developed to use landmarks and measurements that can be altered by common surgical procedures. Identification of landmarks in cephalometry is very important and useful for orthognathic surgery. The aim of this study was to evaluate the accuracy of linear measurement based on digital lateral cephalograms (DLC) and on lateral cephalograms obtained from cone-beam computed tomography (CBCT) scans. Materials and Methods: The linear distances between anatomic landmarks on 6 dry human skulls were measured by 2 observers using digital calipers for sella-nasion (S-N), menton-nasion (M-N), anterior nasal spine-nasion (ANS-N), anterior nasal spine-posterior nasal spine (ANS-PNS), and pogonion-gonion (Pog-Go). Then, images were obtained by using DLCs and in lateral cephalograms obtained from CBCT scans. The measurement errors were calculated for each modality, compared with each other, and analyzed via SPSS software version 18. Results: For all lines (S-N, M-N, ANS-N, Pog-Go, and ANS-PNS), CBCT-derived values did not differ from actual dry skull dimensions (gold standard) (P > 0.05). In DLC, for S-N, M-N, ANS-N, and Pog-Go lines, measurements were significantly higher than actual measurements (P ≤ 0.05), but ANS-PNS values did not differ from actual measurements (P > 0.05). Conclusions: The results showed that the values obtained in CBCT imaging compared with calculated values of the digital lateral cephalometry much closer to the actual distance are more accurate indicators of this type of imaging and that CBCT permits oral surgeons to visualize the position and surgical anatomy of the tooth as it will be seen in the operating theater and allows orthodontists to plan directional traction.