Limits...
Increased prediction of right nonrecurrent laryngeal nerve in thyroid surgery using preoperative computed tomography with intraoperative neuromonitoring identification.

Gao EL, Zou X, Zhou YH, Xie DH, Lan J, Guan HG - World J Surg Oncol (2014)

Bottom Line: All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM).Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN.Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

View Article: PubMed Central - PubMed

Affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, No, 188 Shizi Street, Suzhou 215006, Jiangsu, People's Republic of China. 21474646@qq.com.

ABSTRACT

Background: A nonrecurrent laryngeal nerve (NRLN) is a rare but potentially serious anatomical variant. Although the incidence is reported to be 0.3% to 1.3%, it carries a much higher risk of palsy during thyroid surgery. The objective of this study is to investigate the usefulness of computed tomography (CT) for preoperative identification and intraoperative neuromonitoring identification (IONM) of NRLN in thyroid cancer patients.

Methods: The preoperative neck CT scans from 1,574 patients who needed thyroid surgery were examined. Absence of the brachiocephalic artery (BCA) and the presence of arteria lusoria were defined as positive with NRLN. Systematic intraoperative neuromonitoring (IONM) was also carried out for these 1,574 patients to localize and identify NRLN. A negative electromyography (EMG) response from lower vagal stimulation but a positive EMG response from the upper position indicated the occurrence of an NRLN.

Results: Nine NRLN (0.57%) were intraoperatively identified out of the 1,574 patients, and no patient with a NRLN showed preoperative clinical symptoms related to NRLN. Prior to the operation, surgeons identified only seven suspected NRLN cases based on identification of arteria lusoria. But a review of CT scans revealed that all cases could be identified by vascular anomalies. All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM). Postoperative vocal cord function was normal in all patients.

Conclusions: CT of the neck is a reliable method for predicting NRLN before thyroid cancer surgery. However, some image features can be easily missed. Neurophysiology helps the surgeon to identify the NRLNs more precisely. Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN. Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

Show MeSH

Related in: MedlinePlus

Computed tomography (CT) scans showing thearteria lusoriacoming from the dorsal side of the aortic arch.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4150955&req=5

Fig2: Computed tomography (CT) scans showing thearteria lusoriacoming from the dorsal side of the aortic arch.

Mentions: All nine NRLNs (0.58%) were detected with IONM. Specifically, the two patients without preoperative recognition were also detected due to the negative EMG signals from the lower portion but positive responses from the upper portion vagal stimulation. None of the nine cases developed permanent or temporary palsy after surgery. There was not any complication attributed to the application of IONM. Computed tomographic angiography (CTA) was performed in five cases. The imaging showed that the arteria lusoria originated from the distal part of the aortic arch, traveled through the esophagus posteriorly and reached the right axillary area (Figures 2 and3). Magnetic resonance angiographic (MRA) imaging also showed that the brachiocephalic artery was absent but that the arteria lusoria was present (Figure 4).Figure 2


Increased prediction of right nonrecurrent laryngeal nerve in thyroid surgery using preoperative computed tomography with intraoperative neuromonitoring identification.

Gao EL, Zou X, Zhou YH, Xie DH, Lan J, Guan HG - World J Surg Oncol (2014)

Computed tomography (CT) scans showing thearteria lusoriacoming from the dorsal side of the aortic arch.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4150955&req=5

Fig2: Computed tomography (CT) scans showing thearteria lusoriacoming from the dorsal side of the aortic arch.
Mentions: All nine NRLNs (0.58%) were detected with IONM. Specifically, the two patients without preoperative recognition were also detected due to the negative EMG signals from the lower portion but positive responses from the upper portion vagal stimulation. None of the nine cases developed permanent or temporary palsy after surgery. There was not any complication attributed to the application of IONM. Computed tomographic angiography (CTA) was performed in five cases. The imaging showed that the arteria lusoria originated from the distal part of the aortic arch, traveled through the esophagus posteriorly and reached the right axillary area (Figures 2 and3). Magnetic resonance angiographic (MRA) imaging also showed that the brachiocephalic artery was absent but that the arteria lusoria was present (Figure 4).Figure 2

Bottom Line: All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM).Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN.Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

View Article: PubMed Central - PubMed

Affiliation: Department of General Surgery, The First Affiliated Hospital of Soochow University, No, 188 Shizi Street, Suzhou 215006, Jiangsu, People's Republic of China. 21474646@qq.com.

ABSTRACT

Background: A nonrecurrent laryngeal nerve (NRLN) is a rare but potentially serious anatomical variant. Although the incidence is reported to be 0.3% to 1.3%, it carries a much higher risk of palsy during thyroid surgery. The objective of this study is to investigate the usefulness of computed tomography (CT) for preoperative identification and intraoperative neuromonitoring identification (IONM) of NRLN in thyroid cancer patients.

Methods: The preoperative neck CT scans from 1,574 patients who needed thyroid surgery were examined. Absence of the brachiocephalic artery (BCA) and the presence of arteria lusoria were defined as positive with NRLN. Systematic intraoperative neuromonitoring (IONM) was also carried out for these 1,574 patients to localize and identify NRLN. A negative electromyography (EMG) response from lower vagal stimulation but a positive EMG response from the upper position indicated the occurrence of an NRLN.

Results: Nine NRLN (0.57%) were intraoperatively identified out of the 1,574 patients, and no patient with a NRLN showed preoperative clinical symptoms related to NRLN. Prior to the operation, surgeons identified only seven suspected NRLN cases based on identification of arteria lusoria. But a review of CT scans revealed that all cases could be identified by vascular anomalies. All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM). Postoperative vocal cord function was normal in all patients.

Conclusions: CT of the neck is a reliable method for predicting NRLN before thyroid cancer surgery. However, some image features can be easily missed. Neurophysiology helps the surgeon to identify the NRLNs more precisely. Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN. Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

Show MeSH
Related in: MedlinePlus