Felipe Rafael Zaldívar-Ramírez

Selective use of drains in thyroid surgery

To identify whether there are differences in the use of drains and, if used, which would be the best for thyroid surgery.

Combined use of fine-needle aspiration biopsy, MIBI scans and frozen section biopsy offers the best diagnostic accuracy in the assessment of the hypofunctioning solitary thyroid nodule

PurposeThe probability of malignancy is increased in hypofunctioning solitary thyroid nodules (HFNs). Fine-needle aspiration biopsy (FNA), 99mTc-methoxyisobutylisonitrile (MIBI) and frozen section biopsy (FS) have limited independent diagnostic accuracy for the differential diagnosis of HFNs. The goal of this study was to assess the accuracy of the three independent diagnostic methods in distinguishing between benign and malignant disease.MethodsA total of 130 patients with an HFN on the 99mTc-pertechnetate scan were included in this study. FNA, MIBI scans, FS, thyroidectomy and histological analysis of surgical specimens for final diagnosis were performed in all patients.ResultsOf the 130 patients, 80 (61.54%) had benign lesions and 50 (38.46%), malignant lesions. FNA was diagnostic in 78/130 (60%) patients and non-diagnostic in 52/130 (40%) patients. None of the patients with a negative MIBI scan had a final histological diagnosis of malignancy, and MIBI scans were negative in 38.46% of patients with non-diagnostic FNA results. FS was diagnostic in 104/130 (80%) patients and non-diagnostic in 26/130 (20%) patients. Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios were 81.3%, 97.8%, 96%, 88%, 36.95 and 0.19 respectively for FNA; 100%, 61.3%, 61.7%, 100%, 2.58 and 0 respectively for MIBI; and 80.5%, 100%, 100%, 89%, 0 and 0.2 respectively for FS. Use of both MIBI scans and FS in patients with non-diagnostic FNA rendered a specificity and sensitivity of 100%.ConclusionMIBI scans exclude malignancy in a significant proportion of patients with non-diagnostic FNAs (38% in this study). Cystic nodules with a positive MIBI scan should be further investigated even when the FNA result indicates a benign lesion. Combined use of FNA, MIBI and FS offers the best diagnostic accuracy.

Risk of Injury to the External Branch of the Superior Laryngeal Nerve in Thyroidectomy

Objective To establish in the Mexican population with thyroid disease the risk of injury to the external branch of the superior laryngeal nerve (EBSLN) based on its anatomical position.

Efficacy of Intraoperative Neuro-Monitoring to Localize the External Branch of the Superior Laryngeal Nerve.

BACKGROUND This study investigated whether visual localization of the external branch of the superior laryngeal nerve (EBSLN) coincides with its localization via intraoperative neuro-monitoring (IONM) during thyroidectomy and whether its use influences the frequency of injuries. METHODS A prospective, comparative, cross-sectional, observational study was performed in 240 superior thyroid poles. The metrics were visual identification of the EBSLN and its corroboration with IONM. The frequency of EBSLN injuries was also determined. Statistical analysis was achieved via kappa and chi-square tests, as well as odds ratios (OR). RESULTS Of the 240 superior thyroid poles, IONM identified 234 (97.5%) EBSLN, whereas 190 (79.1%) were identified visually: OR = 10.35 [CI 4.37-24.65] p < 0.0001. Of the 190 EBSLN identified visually, 150 were confirmed through IONM. Indeed, their structure corresponded to an EBSLN to yield a kappa with a linear weighting value of 0.362. The standard error was 0.0467 [CI 0.2686-0.4554], indicating a fair agreement between the visual and IONM classification. CONCLUSION IONM identified 97.5% of EBSLN cases. It was higher than the visual identification. There were no injuries to EBSLN identified through IONM.