Muscle invasion in oropharyngeal carcinoma undergoing transoral robotic surgery.

BACKGROUNDS: Pathologic features of oropharyngeal squamous cell carcinoma (OPSCC) treated with trans-oral robotic surgery predict prognosis and adjuvant therapy. We hypothesized that pathologic muscle invasion (pMI) is associated with poor pathological markers. METHODS: Retrospective review of surgically treated OPSCC to identify pMI and its association with poor pathologic markers. RESULTS: pMI was present in 12/37 patients, and compared to non-pMI, was associated with higher rates of lymphovascular invasion (75% vs. 36%, p = 0.03), perineural invasion (16.7% vs. 0%, p = 0.04), extranodal extension (66.7% vs. 20%, p < 0.01), and tumor stage (8.3% vs. 48% pT1, 75% vs. 52% pT2 and 16.7% vs. 0% pT3). pMI was associated with having a positive margin on main specimen (41.7% vs. 12%, p = 0.04) but not after considering additional margins. CONCLUSIONS: Muscle invasion was associated with higher pathologic tumor staging, poor pathologic factors, and higher rates of positive margin on main specimen.

A systematic approach to the recurrent laryngeal nerve dissection at the cricothyroid junction.

BACKGROUND: To describe and evaluate a four step systematic approach to dissecting the recurrent laryngeal nerve (RLN) starting at the cricothyroid junction during thyroid surgery (subsequently referred to as the retrograde medial approach). METHODS: All thyroidectomies completed by the senior author between August 2014 and January 2016 were retrospectively reviewed. Patients were excluded if concurrent lateral or central neck dissection was performed. A follow up period of 1 year was included. RESULTS: Surgical photographs and illustrations demonstrate the four steps in the retrograde medial approach to dissection of the RLN in thyroid surgery. Three hundred forty-two consecutive thyroid surgeries were performed in 17 months, including 213 hemithyroidectomies, 91 total thyroidectomies, and 38 completion thyroidectomies. The rate of temporary and permanent hypocalcemia was 13% (95% confidence interval [CI]: 8-20%) and 3% (95% CI: 1-8%) respectively. The rate of temporary and permanent vocal cord palsy was 9% (95% CI: 6-12%) and 0.3% (95%CI: 0.01-2%) respectively. The median surgical times for hemithyroidectomy, total thyroidectomy, and completion thyroidectomy were 39 min (Interquartile range [IQR]: 33-47 min), 48 min (IQR: 40-60 min), and 40 min (IQR: 35-51 min) respectively. 1% of cases required conversion to an alternative surgical approach. CONCLUSION: In a tertiary endocrine head and neck practice, the routine use of the retrograde medial approach to RLN dissection is safe and results in a short operative time, and a low conversion rate to other RLN dissection approaches.

A procedure for sampling and analysis of air for energetics and related compounds.

A procedure for the sampling and analysis of energetics and related compounds in the atmosphere is described. The basic procedure consists of the collection of air samples using sampling cartridges containing XAD-2 resin, extraction of the resin with isoamyl acetate, and an analysis of the extract using gas chromatography with electron capture detection. Modifications and additions to this procedure are discussed, such as the use of a prefilter before the resin sampler to collect particulates and the use of a mass selective detector to analyze for some propellant compounds of interest or for quantitative confirmation purposes. Two differing sizes of samplers are evaluated according to the air volumes required for collection. The procedure is tested through the analysis of spiked resin samples, which had air pulled through them for periods of time corresponding with the required sampling volumes. This procedure has application toward the measurement of energetic residues in atmospheres resulting from weapons testing and operations during training exercises involving munitions.