The Basis of Preoperative Vocal Fold Paralysis in a Series of Patients Undergoing Thyroid Surgery: The Preponderance of Benign Thyroid Disease
ABSTRACT Preoperative vocal fold paralysis (VFP) is thought to be rare in patients with benign thyroid disease (BTD). In contrast with cases of malignancy, in which the recurrent laryngeal nerve (RLN) should be severed, in patients with BTD and VFP the RLN can be preserved without threatening patients' lives. This study investigates the clinical features that enable identification of patients who have VFP associated with BTD.
Medical records of 187 consecutive patients who underwent thyroid surgery were retrospectively reviewed. The association between preoperative VFP and pathology (benign or malignant), clinical features, and treatment results of patients with BTD and VFP were analyzed.
Of the 187 patients, 145 patients had BTD and 8 of these cases (5.52%) had preoperative unilateral VFP. The prevalence of BTD with VFP was 4.3% (8/187). The other 42 patients had malignant thyroid disease and 4 of these cases (9.52%) had preoperative unilateral VFP. None of the aforementioned VFP was caused by previous thyroidectomy or surgery to the neck. Although the relative risk of VFP in patients with thyroid malignancy was 1.726 (9.52%/5.52%), there was no significant association between VFP and malignancy. Of the eight patients with BTD, benign fine-needle aspiration cytology or frozen sections, goiter with a diameter larger than 5 cm, cystic changes, and significant radiologic tracheo-esophageal groove compression were the common findings. During thyroidectomy, the RLN was injured but repaired in three patients. Two events occurred in patients who had severe RLN adhesion to the tumor caused by thyroidectomy performed decades ago. Two of the five patients without nerve injury recovered vocal fold function. The overall VFP recovery rate for patients with BTD and VFP was 25% (2/8).
Preoperative unilateral VFP is not uncommon in thyroid surgery. Obtaining information on laryngeal function is of extreme importance when planning surgery, especially contralateral surgery. Goiter with preoperative VFP is not necessarily an indicator of malignancy. Benign perioperative cytopathologic findings with typical radiographic compression strongly suggest that VFP is caused by BTD. If, during thyroidectomy, the RLN is carefully preserved, recovery of vocal fold function may still be possible.
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ABSTRACT: According to some authors, routine preoperative laryngoscopy should be the standard of care in all patients undergoing thyroid surgery. The rationale for this approach is (I) the risk that a patient has a preoperative vocal cord palsy (VCP) without symptoms; (II) the presence of VCP preoperatively is suggestive of invasive malignancy; (III) it is relevant for the use of intraoperative nerve monitoring; and (IV) surgical strategy may be better defined if a paralysed vocal cord is detected preoperatively. This is a review of studies of patients who underwent routine preoperative laryngoscopy to anticipate preoperative VCP and that evaluated related risk factors, including previous surgery, voice function complaints, and a diagnosis of malignancy. The estimated risk of sustaining preoperative VCF in the absence of these factors was determined. The relevant current guidelines from different professional bodies are also addressed. The level of evidence that supports routine preoperative laryngoscopy is weak. The risk of harboring preoperative VCP in the absence of previous neck or other risk-related surgery, advanced malignancy or voice symptoms is very low (0.5% of cases). Selective rather than routine use of preoperative laryngoscopy may be acceptable provided that the risk of undetected paralysis is as low as can be reasonably ascertained from the available literature.
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ABSTRACT: Objective:Our objective was to verify the analytical performance of the Afirma gene expression classifier (GEC) in the classification of cytologically indeterminate thyroid nodule fine-needle aspirates (FNAs).Design:Analytical performance studies were designed to characterize the stability of RNA in FNAs during collection and shipment, analytical sensitivity as applied to input RNA concentration and malignant/benign FNA mixtures, analytical specificity (i.e. potentially interfering substances) as tested on blood and genomic DNA, and assay performance studies including intra-nodule, intraassay, inter-assay, and inter-laboratory reproducibility.Results:RNA content within FNAs preserved in FNAProtect is stable for up to 6 d at room temperature with no changes in RNA yield (P = 0.58) or quality (P = 0.56). FNA storage and shipping temperatures were found to have no significant effect on GEC scores (P = 0.55) or calls (100% concordance). Analytical sensitivity studies demonstrated tolerance to variation in RNA input (5-25 ng) and to the dilution of malignant FNA material down to 20%. Analytical specificity studies using malignant samples mixed with blood (up to 83%) and genomic DNA (up to 30%) demonstrated negligible assay interference with respect to false-negative calls, although benign FNA samples mixed with relatively high proportions of blood demonstrated a potential for false-positive calls. The test is reproducible from extraction through GEC result, including variation across operators, runs, reagent lots, and laboratories (sd of 0.158 for scores on a >6 unit scale).Conclusions:Analytical sensitivity, analytical specificity, robustness, and quality control of the GEC were successfully verified, indicating its suitability for clinical use.The Journal of Clinical Endocrinology and Metabolism 10/2012; 97(12). DOI:10.1210/jc.2012-1923 · 6.31 Impact Factor
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ABSTRACT: Routine preoperative laryngeal examination remains controversial. We aimed to assess the utility of preoperative routine flexible laryngoscopy (FL) by looking at the incidence, clinical significance and predictors for preoperative vocal cord paresis (VCP) and incidental laryngopharyngeal conditions (LPC) in our consecutive cohort. A total of 302 patients underwent laryngeal examination by an independent otorhinolaryngologist and were specifically asked about voice/swallowing symptoms suggestive of VCP 1 day before surgery. As well as vocal cord (VC) mobility, the naso-pharynx and larynx were examined using FL. Any VCP and/or LPC was recorded. VCP was defined as reduced or absent movement in one or more VC. An LPC was considered clinically significant if the ensuing thyroidectomy was changed or deferred. Seven (2.3 %) patients had preoperative VCP, while an additional seven patients had an incidental LPC. Of the seven VCPs, five were caused by previous thyroidectomy, while two were caused by a benign goitre. The incidence of asymptomatic VCP in a previously non-operated cohort was 1/245 (0.41 %). Voice/swallowing symptoms (p = 0.033) and previous thyroidectomy (p < 0.001) were the two significant predictors for VCP. The seven incidental LPCs were vallecular cyst (n = 1), VC scar and polyp (n = 2), nasopharyngeal cyst and polyp (n = 3) and redundant arytenoid mucosa (n = 1); however, as they were benign, all seven patients proceeded to thyroidectomy as planned. Given the low incidence (0.41 %) of asymptomatic VCP in a previously non-operated cohort and that none of the seven LPCs were considered clinically significant, routine preoperative laryngoscopic examination should be reserved for those with previous thyroidectomy and/or voice/swallowing symptoms.World Journal of Surgery 09/2013; 38(2). DOI:10.1007/s00268-013-2259-3 · 2.35 Impact Factor