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Continuous vagal IONM prevents recurrent laryngeal nerve paralysis by revealing initial EMG changes of impending neuropraxic injury: A prospective, multicenter study

Existing intraoperative neuromonitoring (IONM) formats stimulate the recurrent laryngeal nerve (RLN) intermittently, exposing it to risk for injury in between stimulations. We report electrophysiologic parameters of continuous vagal monitoring, utilizing a novel real‐time IONM format, and relate these parameters to intraoperative surgical maneuvers that delineate nascent adverse but reversible electrophysiologic parameters to prevent nerve injury. These results are correlated with postoperative vocal cord functional outcome.

Clinical and epidemiological features of oral cancer in a medical school teaching hospital from 1994 to 2002: increasing incidence in women, predominance of advanced local disease, and low incidence of neck metastases

PURPOSE Description of clinical and epidemiological characteristics of patients who underwent surgery for oral cancer in a Medical School Teaching Hospital, and determination of differences with respect to other institutions and/or periods of time. METHOD The charts of patients undergoing surgery for oral cancer from 1994 to 2002 were reviewed. Data were collected in a spreadsheet in order to analyze clinical and epidemiological features.. RESULTS A total of 374 patients having undergone 406 operations was identified. Their ages varied from 14 to 94 years (mean = 57.4 years), with 255 men (68.2%), and 295 out 366 Caucasian (80.6%). A majority had tumors of the tongue and/or floor of mouth (55.6%), while 20.3% had lip cancer. Squamous cell carcinoma was found in 90.3%, and glandular carcinoma in 4%. T4 tumors in 39.6%, Tis or T1 lesions in 15.2% of all patients. Nearly 62% had no regional metastases, and the relative incidence in young patients (40 years or younger) reached 8.6%. CONCLUSION In spite of the predominance of locally advanced tumors, a majority of patients had no neck metastases. The 31.8% incidence in females indicates an increasing incidence of oral cavity cancer among women when compared to previous periods at the same institution.

The nonrecurrent laryngeal nerve: Anatomic and electrophysiologic algorithm for reliable identification

The recurrent laryngeal nerve (RLN) intraoperative monitoring (IONM) provides a new functional dynamic that adds to visual identification of the RLN to optimize its intraoperative management. Intraoperative monitoring has been applied to the initial identification of the RLN. We now apply IONM to the identification of the nonrecurrent laryngeal nerve (NRLN) and provide electrophysiologic and anatomic parameters to facilitate this technique of neural identification for the NRLN, which is at increased risk of injury during thyroid surgery.

Recurrent Laryngeal Nerve Monitoring during Thyroid Surgery Normative Vagal and Recurrent Laryngeal Nerve Electrophysiological Data

Objective Injury to the recurrent laryngeal nerve (RLN) remains a significant cause of morbidity during thyroid surgery. Intraoperative nerve monitoring (IONM) is being applied in many centers to facilitate nerve identification. The aim of this study was to elucidate normative human vagal and recurrent laryngeal nerve electromyograhic (EMG) parameters during standard IONM application. Study Design A prospective IONM study conducted over an 8-month period. Internal review board (IRB) approval was obtained. Settings Department of Otolaryngology, Division of Thyroid and Parathyroid Surgery, Massachusetts Eye and Ear Infirmary, Boston. Subjects and Methods All patients who were scheduled for routine thyroid, parathyroid, or neck exploration surgery were invited to participate. All patients had a preoperative and postoperative laryngeal examination to assess vocal cord function. Any patient with an abnormal preoperative laryngeal examination was excluded. Results Fifty-eight patients participated in this study. The right and left RLN latencies were similar. The left vagus latency was greater than the right vagus but was not significant. The RLN latency was significantly less than the vagus nerve. The right vagus nerve amplitude was significantly greater than the left. There was no difference between male and female amplitudes for either the RLN or vagus nerve. Conclusion This study highlights the electrophysiological/EMG differences and similarities between the RLN and vagus nerve. Normative amplitude measurements for bilateral RLN and vagus nerve stimulation are presented. There are limited data available in the literature on normal RLN and vagal EMG signals generated during thyroid surgery.

p53 and skin carcinomas with skull base invasion : A case-control study

BACKGROUND: Some skin carcinomas may be very aggressive. Increased expression of the protein p53 has been associated with tumor aggressiveness. In this study, p53 expression was evaluated in basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) with skull base invasion, and was compared to tumors with good outcome. STUDY DESIGN AND SETTING: Expression of p53 was immunohistochemically analyzed and it was reported as present or absent in 24 BCC and 11 SCC with skull base invasion. Control group (good outcome) included 23 BCC and 10 SCC. RESULTS: Expression of p53 was noted in 70.83% of BCC with skull base invasion, compared to 43.48% in the control group (P = 0.058). Regarding SCC, p53 positivity was noted in only 9.09% of SCC with skull base invasion, compared to 40.00% in the control group (P = 0.149). CONCLUSIONS: In this study, p53 expression was more common among BCC with skull base invasion, compared to controls with good outcome, and the difference was considered marginally significant. This proportion was reversed in SCC, but the difference was not statistically significant. EBM rating: B-3b

Injury of the external branch of the superior laryngeal nerve in thyroid surgery

The external branch of the superior laryngeal nerve (EBSLN) innervates the cricothyroid muscle (CTM) to promote lengthening and thinning of the vocal fold, thus increasing voice pitch. The close relation with the superior thyroid vessels (STV) puts the EBSLN in risk every time the superior pole of the thyroid is dissected. It travels downward to innervate the CTM, lateral to the thyroid cartilage and to the inferior pharyngeal constrictor muscle (IPCM), being eventually covered by this muscle fibers as it approaches its entry point. During its descending course, the EBSLN curves and crosses the STV posteriorly. The lower this crossing occurs in the neck, the higher the risk of surgical damage to the nerve by transection, traction, entrapment, thermal damage or disrupted blood supply. The chances of surgical trauma are also increased by size and weight of the specimen, shorter neck length and non-white ethnicity. Voice changes following thyroid surgery are common and multifactorial. The actual rate of vocal impairment due to EBSLN injury is unclear, since changes to the everyday speaking voice can be minimal and laryngeal findings are usually subtle and controversial. CTM electroneuromyography (EMG) is the most accurate tool to diagnose abnormal EBSLN conductivity, but it is technically difficult and barely applicable in routine practice. Recommended approaches to prevent injury include: (I) individual distal ligature of the STV by the thyroid capsule; (II) visual identification of the nerve and its trajectory and (III) electrostimulation with either observation of CTM twitch or intraoperative nerve monitoring (IONM) via dedicated endotracheal tube electrodes. There is accumulating evidence that a combination of visual and standardized electrophysiological EBSLN identification with meticulous division of the STV improves preservation rates. IONM bears the additional benefits of prognostication, quantification and documentation of neural function once it allows intraoperative laryngeal EMG.