Assessment of Angular Insertion-Depth of Bilateral Cochlear Implants Using Plain X-ray Scans.

OBJECTIVE: To evaluate in cochlear implant patients, the feasibility and reliability of angular depth of insertion (aDOI) measurements using plain x-ray scans. STUDY DESIGN: Retrospective study where three observers independently evaluated and compared intraoperative anterior-posterior and oblique x-ray scans. SETTING: A tertiary pediatric medical center. PATIENTS: Included were 50 children (100 ears) who underwent bilateral simultaneous cochlear implantation during 2008 to 2015. MAIN OUTCOME MEASURES: Inter-rater agreement of aDOI measured in plain x-ray scans; effect of head position on measured aDOI; and symmetry of aDOI between patients' ears in bilateral simultaneous cochlear implantations. RESULTS: Differences in the average aDOI measurements among the three observers ranged between 2 and 7 degrees. There was high inter-rater agreement (R = 0.99, p < 0.01) among all observers, and strong correlations between each pair of observers (0.92-0.99). Head rotation of 45 degrees (between the two views) resulted in a median difference in aDOI of 14 degrees, with excellent correlation among the observers. The rate of asymmetry was high, with a median difference of 39 degrees and up to 220 degrees between ears. CONCLUSIONS: Assessment of aDOI using intraoperative plain x-rays is efficient and reliable. The effect of head positioning on measurement is small. Further studies are needed to evaluate the effect of aDOI and insertion symmetry on functional outcomes.

Is There Justification for Total Thyroidectomy in Low-Risk Papillary Thyroid Carcinoma? A Decision-Analysis Model.

BACKGROUND: Low-risk papillary thyroid carcinoma is commonly treated surgically. However, uncertainties exist in regard to the optimal extent of surgery. We approached this question using a decision-analysis model. METHODS: A Markov model was used to compare outcome between patients with small (1-2 cm) low-risk PTC treated by hemithyroidectomy or total thyroidectomy. Probabilities and utilities were derived from the literature. The model was evaluated with Monte Carlo simulation. Sensitivity analysis was used to determine which variables most affected the model. RESULTS: Hemithyroidectomy was associated with a minor increase in mortality risk. After incorporation of mortality risk, complications, and quality-of-life measures, hemithyroidectomy was found to be superior to total thyroidectomy, with an increasing benefit over time. Quality-of-life measures, especially disutility of disease recurrence and undergoing surgery, had the greatest effect on the incremental benefit of hemithyroidectomy. CONCLUSION: Based on our decision-analysis model, hemithyroidectomy is the preferred option in low-risk PTC.

Is there a role for elective neck dissection with salvage laryngectomy? A decision-analysis model.

OBJECTIVES/HYPOTHESIS: Elective neck dissection for the clinically negative neck is often a matter of debate. A decision-analysis model that was published in 1994 established the widely accepted principle that neck dissection is warranted when the risk for occult metastases is higher than 20%. The aim of the present study was to build a specific and up-to-date decision-analysis model to determine the need for elective neck dissection during salvage laryngectomy after chemoradiation failure and to identify the variables that effect the decision. STUDY DESIGN: Decision-analysis model. METHODS: A decision-analysis model was performed to compare the outcome of patients after salvage total laryngectomy with and without an elective neck dissection. Probabilities and expected utilities were derived from available literature to construct the model. Monte Carlo simulation and sensitivity analysis were used to calculate our models' outcomes and to identify the variables that influence the model most, respectively. RESULTS: When calculating our model results with published data, we found that elective neck dissection is not warranted during salvage total laryngectomy. Optimal decision was found to be sensitive by two variables: 1) the probability for cure with neck dissection, and 2) the probability for regional-only recurrence after salvage laryngectomy without neck dissection. In multiway sensitivity analysis, only when cure rate with neck dissection exceeded 82%, adding neck dissection was the preferred decision. In practice, cure rates for patients after salvage total laryngectomy are around 50% to 65%. CONCLUSIONS: Based on our decision-analysis model, we do not recommend routine elective neck dissection during salvage total laryngectomy after failure of chemoradiation.