Effect of tonsillectomy on the adult voice.

OBJECTIVES AND HYPOTHESIS: Anecdotal evidence suggests that tonsillectomy has no deleterious consequences on a person's voice under normal vocal demand. However, whether the enlarged dimensions of the oropharynx after tonsillectomy impair the quality of a professional voice user remains unclear. Therefore, we designed a study to determine whether adult tonsillectomy altered the resonance characteristics of the vocal tract in any way and whether these changes were transient or permanent. STUDY DESIGN: This is a prospective observational study with full institutional ethical approval. METHODS: All adult patients presenting for tonsillectomy for recurrent tonsillitis in our institution were recruited. Their voice was recorded preoperatively, postoperatively, and at 4 weeks postoperatively. The values of the first four formants were calculated in all recordings. The oropharyngeal dimensions were measured preoperatively and postoperatively. Tonsillar weights and volumes were also measured. RESULTS: The first formant was noted to rise postoperatively. The average value of F2 and F3 did not alter postoperatively or at 4 weeks. However, it was noted that the fourth formant was not universally present preoperatively but was present in all patients postoperatively and at 4 weeks. CONCLUSIONS: Altering the dimensions of the oropharynx after tonsillectomy causes the first formant to rise but has no effect on the third and fourth formants. However, the fourth formant appears in patients who previously did not demonstrate it. The fourth formant was present in a greater proportion of male patients preoperatively than female patients, but it was universally present postoperatively and at 4 weeks in both sexes. This suggests that increasing the horizontal dimensions of the oropharynx has a nontransient effect on the higher order formants of the voice.

Investigation of the impact of thyroid surgery on vocal tract steadiness.

INTRODUCTION: Subjective nonspecific upper aerodigestive symptoms are not uncommon after thyroid surgery. These are postulated to be related to injury of an extrinsic perithyroid nerve plexus that innervates the muscles of the supraglottic and glottic larynx. This plexus is thought to receive contributing branches from both the recurrent and superior laryngeal nerves. PATIENTS AND METHODS: The technique of linear predictive coding was used to estimate the F(2) values from a sustained vowel /a/ in patients before and 48 hours after thyroid or parathyroid surgery. These patients were controlled against a matched pair undergoing surgery without any theoretical effect on the supraglottic musculature. In total, 12 patients were recruited into each group. Each patient had the formant frequency fluctuation (FFF) and the formant frequency fluctuation ratio (FFFR) calculated for F(1) and F(2). RESULTS: Mixed analysis of variance (ANOVA) for all acoustic parameters revealed that the chiF(2)FF showed a significant "time" main effect (F(1,22)=7.196, P=0.014, partial eta(2)=0.246) and a significant "time by group interaction" effect (F(1,22)=8.036, P=0.010, eta(p)(2)=0.268), with changes over time for the thyroid group but not for the controls. Similarly, mean chiF(2)FFR showed a similar significant "time" main effect (F(1,22)=6.488, P=0.018, eta(p)(2)=0.228) and a "time by group interaction" effect (F(1,22)=7.134, P=0.014, eta(p)(2)=0.245). CONCLUSIONS: This work suggests that thyroid surgery produces a significant reduction in vocal tract stability in contrast to the controls. This noninvasive measurement offers a potential instrument to investigate the functional implications of any disturbance that thyroid surgery may have on pharyngeal innervations.

Cone-beam computed tomography on a mobile C-arm: novel intraoperative imaging technology for guidance of head and neck surgery.

OBJECTIVES: A conventional approach to image-guided surgery relies on positional tracking relative to preoperative images. We investigated the performance of intraoperative cone-beam computed tomography (CBCT) on a mobile C-arm for real-time guidance of head and neck surgery. Objectives were as follows: (1) to quantify improvements in surgical performance achieved with intraoperative CBCT and (2) to investigate specific, challenging surgical tasks for which CBCT is essential for total target ablation and critical structure avoidance. METHODS: Surgical performance was evaluated using a phantom model in which a simulated skull base lesion was excised with and without intraoperative CBCT guidance. Performance was quantified by means of statistical decision theory analysis for conservative and radical excision tasks, yielding measures of sensitivity and specificity for each surgical task. Cadaveric specimens were employed to demonstrate the efficacy of CBCT guidance in sinus and skull base surgery. RESULTS: Performance under CBCT guidance was significantly increased in all cases, particularly for radical excision tasks in proximity to critical normal structures. Cadaver studies demonstrated that CBCT-guided procedures yielded higher-quality surgical product and higher conformity to surgical margins with dramatically increased surgical confidence. CONCLUSIONS: Intraoperative CBCT quantifiably improved surgical performance in all excision tasks and significantly increased surgical confidence. CBCT offers an intraoperative three-dimensional imaging technology that provides exquisite, real-time visualization of sinus and skull base anatomy. Such intraoperative imaging in combination with real-time tracking and navigation should be of great benefit in delicate procedures in which excision must be executed in close proximity to critical structures.

Completion thyroidectomy versus total thyroidectomy: is there a difference in complication rates? An analysis of 350 patients.

BACKGROUND: This study compared our experience with completion thyroidectomy (CT) and total thyroidectomy (TT) in the management of well-differentiated thyroid cancer (WDTC). We compared complication rates and analyzed the implications of the intraoperative management of the parathyroid glands. STUDY DESIGN: We performed a retrospective cohort study comparing outcomes between patients undergoing CT and TT between January 1994 and December 2004. All patients had surgery for either suspected or confirmed WDTC on fine-needle aspiration. RESULTS: There were 201 CTs and 149 TTs. Mean hospital stays were 4.5 and 3.5 days for the CT and TT groups, respectively (p=0.001). Temporary recurrent laryngeal nerve paresis occurred in 2.0% (4 of 201) and 3.3% (5 of 149) of patients in the CT and TT groups, respectively. There was one (0.5%) case of permanent recurrent laryngeal nerve paralysis in the CT group. Permanent hypoparathyroidism rates were 2.5% and 3.3% in the CT and TT groups, respectively. There was no difference between the two groups in terms of total numbers of parathyroid glands autotransplanted (p=0.63) or present in the specimen (p=0.26). CONCLUSIONS: Completion thyroidectomy is a safe and appropriate option in the management of select cases of WDTC in which a definitive preoperative or intraoperative diagnosis is not available. But it requires a longer hospitalization, so it has implications for both hospital resources and the patients involved.

Thyroid scintigraphy in the assessment of the solitary thyroid nodule: differences in practice patterns between family physicians and specialists.

OBJECTIVE: It has been shown that there is considerable variation in the diagnosis and management of the thyroid nodule. The purpose of this study was to investigate the differences in the practice of family physicians and specialists in ordering thyroid scans in the initial workup of patients with thyroid nodules. DESIGN: Retrospective electronic and paper-based chart review. SETTING: University Health Network, Toronto. PARTICIPANTS: All patients who underwent thyroidectomy over a 2-year period. INTERVENTIONS: An audit of their preoperative diagnostic tests was performed, and the specialties of the ordering physicians were identified. RESULTS: One hundred ninety-four patients were assessed. Sixty-three patients (32.5%) were investigated exclusively by their family physician, 63 (32.5%) were investigated exclusively by a specialist, and 68 (35%) were investigated by both. Family physicians ordered thyroid scans in 51% of patients, whereas specialists ordered scans in 29% of patients (p<.001). The medical specialists ordered 36 scans (33.6%) in 107 patients, whereas the surgical specialists ordered 2 (8.3%) scans in 24 patients (p<.001). CONCLUSION: Despite the limited role for thyroid scans in the initial workup of a solitary thyroid nodule, they are still frequently ordered, particularly by family physicians. We recommend publication of Canadian evidence-based guidelines for the management of thyroid nodules, similar to existing American guidelines, which could help reduce the amount of unnecessary testing.

Intraoperative cone-beam CT for guidance of temporal bone surgery.

OBJECTIVES: To describe our preclinical experience with Cone Beam CT (CBCT) in image-guided surgery of the temporal bone. STUDY DESIGN AND SETTINGS: A mobile isocentric C-arm (PowerMobil, Siemens Medical Systems, Erlangen, Germany) modified to include a flat-panel detector (Varian Imaging Products, Palo Alto, CA) and a motorized orbit was developed to acquire multiple projections in rotation about a subject. Initial experiments imaging steel wire in air were used to investigate the system's spatial resolution in 3D image reconstruction. Subsequently temporal bone dissection was performed on five cadaver heads using the modified C-arm as an image guidance system. RESULTS: We obtained a spatial resolution of 0.85 mm. The image acquisition time was 120 seconds and the radiation dose approximately one-tenth of a conventional CT scan. CONCLUSION: CBCT provided submillimeter accuracy at high speed with low radiation dosage to offer utility as an intraoperative imaging system. SIGNIFICANCE: CBCT offers technology that approximates "near-real-time" image guidance. EBM RATING: C-4.

The sternomastoid branch of the occipital artery: a surgical landmark for the spinal accessory nerve in selective neck dissections.

OBJECTIVE: To evaluate the anatomic relationship between the spinal accessory nerve (SAN) and the sternomastoid branch of the occipital artery (SBOA) and its utility as a surgical landmark during a selective neck dissection (SND). STUDY DESIGN AND SETTINGS: Consecutive patients undergoing SND for squamous cancer from October 1, 2004 to February 28, 2005 were enrolled in this study. During surgery the distance between the SBOA and the point of insertion of the SAN into the sternomastoid muscle (SMM) was measured. RESULTS: Twenty-four patients underwent 33 SND. The distance between the SBOA and SAN ranged between 1 and 11 mm, with a mean of 6.2 mm and a median of 6 mm. CONCLUSION: The relationship between these 2 structures has a range and constancy that is acceptable as a landmark. SIGNIFICANCE: This article presents a useful adjunct for location of the SAN in the anterior neck during SND.