Detection of laryngeal tumors and tumoral extension by multislice computed tomography-virtual laryngoscopy (MSCT-VL).

Virtual endoscopy is becoming a widely used non-invasive clinical diagnostic tool. The present study was designed to compare the sensitivity and specificity of the conventional endoscopy and virtual laryngoscopy with respect to laryngeal masses. A total of 38 patients (20 males, 18 females, mean age 61 years) with the complaint of hoarseness were included in the study. Laryngeal mucosa, lumen and mass pathology were evaluated initially by direct endoscopy and then by virtual laryngoscopy during multislice CT of the larynx. Histopathologic evaluation of the masses was also made. The main pathology of the patients was found to be laryngeal masses (60% of patients, one mass for each patient), which were polyps (n = 8), papilloma (n = 4) and carcinoma (n = 11) according to histopathologic evaluation. Retrospective evaluation of 6 lesions detected in virtual but not in conventional laryngoscopy resulted with the finding of viscous-dense mucous secretion. On the contrary, three lesions detected by conventional laryngoscopy could not be detected by virtual evaluation. A total of six patients were evaluated and considered as normal both by conventional and virtual laryngoscopic examinations. Sensitivity of the virtual laryngoscopy was 88% (23/26) while its specificity was only 50% (6/12). Positive and negative predictive values were 79% (23/29) and 66% (6/9), respectively. Accuracy of the virtual laryngoscopy was 76% (29/38). Virtual laryngoscopy is not an alternative to conventional laryngoscopy but may assist direct endoscopy without causing additional radiation exposure or discomfort to the patient. The three-dimensional contribution to interpretation of the results and subsequent manipulation of the data can be used for educational and surgical purposes.

The trigeminal nerve and ganglion: an anatomical, histological, and radiological study addressing the transtrigeminal approach.

BACKGROUND: The transtrigeminal route with splitting of the trigeminal ganglion (TG) is a skull base approach used to expose the posteromedial part of the cavernous sinus (CS), the base of the TG, and the petrolingual ligament (PLL). METHODS: To verify the transtrigeminal approach (TTA), the 3 divisions of the trigeminal nerve (TN), the so-called TG, and the trigeminal root were analyzed anatomically, histologically, and radiologically. The anatomic study was performed bilaterally in 5 cadaveric head specimens. For the histologic study, 6 TN specimens removed from cadavers were used. In addition, the radiologic demonstration of the TN and its so-called ganglion was performed on 5 cases by magnetic resonance imaging (MRI) scan. RESULTS: The TN is composed of linear, crossing, and connecting rootlets. These 3 types of rootlets indicate a plexiform constitution rather than a ganglion even though there are ganglionic cells. Consequently, the term "trigeminal plexus" may be preferred to describe this network. In our new proposed classification, the segments of the TN can be divided into 6 portions according to their relationship with the brainstem, the cisterns, and the bone structures. The first 3 segments before separating into 3 divisions are (1) pontine, (2) cisternal (preganglionic or preplexal), (3) gasserian (ganglionic or plexal). The last 3 segments after the division are (4) preforamino-fissural (postganglionic or postplexal), (5) foramino-fissural, and (6) extracranial (postforamino-fissural). A loose connective tissue along the rootlets of the maxillary and the mandibular divisions of the TN at the gasserian (ganglionic or plexal) segment enabled us to split the so-called "trigeminal ganglion" or "gasserian ganglion" to perform the TTA. CONCLUSION: The TTA is possible, useful, and necessary in selected cases with invasion of the posteromedial part of the CS.