A unique complication of thyroidectomy for Hashimoto's thyroiditis: central retinal artery thrombosis

BACKGROUND

Central retinal artery occlusion (CRAO) is a rare ophthalmological emergency and also a unique complication after thyroid surgery.

METHODS

We present the first case of CRAO following thyroid surgery in a patient with Hashimoto's thyroiditis, along with a variety of interventions to overcome this complication.

RESULTS

A 42-year-old female patient suffering from sudden vision loss following total thyroidectomy was diagnosed with CRAO. Hyperbaric oxygen therapy was started within the postoperative first 6 hours.

CONCLUSION

Although it is extremely rare, it should be noted that patients may experience retinal artery occlusion following the thyroid surgery. Immediate evaluation of patients with visual impairment in the early postoperative period, and planning of emergent hyperbaric oxygen therapy for the management are critical.

Can Unilateral Therapeutic Central Lymph Node Dissection Be Performed in Papillary Thyroid Cancer with Lateral Neck Metastasis?

Objectives

Unilateral or bilateral prophylactic central neck dissection (CND) in papillary thyroid cancer (PTC) is still controversial. We aimed to evaluate the risk factors for contralateral paratracheal lymph node metastasis and whether CND might be performed unilaterally.

Methods

Prospectively collected data of patients who underwent bilateral CND and lateral neck dissection (LND) with thyroidectomy due to PTC with lateral metastases, between January 2012 and November 2019, were evaluated retrospectively. The patients were divided into two groups according to the presence (Group 1) and absence (Group 2) of metastasis in the contralateral paratracheal region.A total of 42 patients (46 ±15.7 years) were operated. In the contralateral paratracheal region, Group 1 (35.7%) had metastases, while Group 2 (64.3%) had no metastases. In groups 1 and 2, metastasis rates were 100% vs 77.8% (p=0.073), 46.7% vs 18.5% (p=0.078), and 80% vs 40.7% (p=0.023) for the ipsilateralparatracheal, prelaryngeal and pretracheal lymph nodes, respectively.The number of metastatic lymph nodes in the central region was significantly higher in Group 1 compared to Group 2 as; 10.7±8.4 vs. 2.6±2.4 (p=0.001) in bilateral central region material; 8.3±7.4 vs. 2.9±2.7 (p=0.001) in lateral metastasis with ipsilateral unilateral central region; 3.8±3.4 vs. 1.9±1.9 (p=0.023) in ipsilateralparatracheal area; and 3.7±4.6 vs. 0.6±0.9 (p=0.001) in pretracheal region, respectively. However, no significant difference was found regarding the prelaryngeal region material (0.9±1.8 vs. 0.2±0.4 (p=0.71)).

Results

>2 metastatic central lymph nodes in unilateral CND material (AUC: 0.814, p<0.001, J=0.563) can estimate contralateral paratracheal metastasis with 93% sensitivity, 63% specificity, while >2 pretracheal metastatic lymph nodes (AUC: 0.795, p<0.001, J: 0.563) can estimate contralateral paratracheal metastasis with 60% sensitivity and 96.3% specificity.

Conclusion

In patients with lateral metastases, the rate of ipsilateralparatracheal metastasis is 85%, while the rate of contralateral paratracheal metastasis is 35.7%. The number of ipsilateral central region or pretracheal lymph node metastases may be helpful in predicting contralateral paratracheal lymph node metastases. Notably, unilateral CND may be performed in the presence of ≤ 2 metastases in the ipsilateral central region.

The Role of Frozen Section Examination in Thyroid Surgery

In endocrine pathology, frozen section (FS) examination is most commonly used for the intraoperative evaluation of thyroid and parathyroid tumors, as well as cervical lymph nodes. In the past, frozen section was considered a fundamental tool in thyroid surgery. However, with advancements in preoperative ultrasound and fine-needle aspiration biopsy (FNAB), there have been increasing queries about its routine use due to the improved preoperative diagnosis. Nowadays, while the use of FS during thyroidectomy has decreased, it is still used as an additional method for different purposes intraoperatively. FS may not always provide definitive results. If FS will alter the surgical plan or extent, it should be applied. Routine FS is not recommended for evaluating thyroid nodules. But in addition to FNAB, if FS results may change the operation plan or extent, they can be utilized. FS should not be applied for thyroid lesions smaller than 1 cm, and the entire lesion should not be frozen for FS. For the assessment of thyroid nodules, the use of FS is recommended based on the Bethesda categories of FNAB. In Bethesda I category nodules, FS may contribute to distinguishing between malignant and benign lesions and guide surgical treatment. In Bethesda II nodules, where the malignancy rate is low, the performance of FNAB and FS can be compared, but it's not recommended due to the lack of a significant contribution to the surgical strategy. The sensitivity of FS in Bethesda III and IV nodules is low; its contribution to the diagnosis is limited, and it does not provide an apparent benefit to treatment; therefore, it is not recommended. In Bethesda V nodules, FS can effectively confirm the malignancy diagnosis, contribute to the surgical strategy, and reduce the possibility of completion thyroidectomy, and accordingly, it is recommended for use. Nonetheless, in Bethesda V nodules with a benign FS report, the malignancy rate remains high, so it should not be used to rule out malignancy. In Bethesda VI nodules, the performance of FS is lower or comparable to FNAB and does not significantly contribute to the treatment strategy; hence, it is not recommended. Particularly in patients with papillary thyroid cancer, intraoperative FS can be effective in detecting extrathyroidal extension and can assist the surgeon in determining the extent of thyroid surgery and central neck dissection. FS has high sensitivity and specificity in evaluating the lymphatic status of the central region intraoperatively and can be used to determine the extent of central compartment node dissection. During thyroidectomy, FS examination can be used in recognizing parathyroid tissue and distinguishing it from fatty tissue, thymus, thyroid, lymph nodes, especially in differentiating metastatic lymph nodes.

The Role of 4D-CT for Pre-Operative Localization in Patients with Primary Hyperparathyroidism with Negative Ultrasonography and/or Sestamibi SPECT/CT

Objectives

The major cause of primary hyperparathyroidism (pHPT) is parathyroid adenoma. Today, minimally invasive parathyroidectomy (MIP) has become the standard treatment for patients in whom the pathological gland can be localized with pre-operative imaging methods. In this study, we aimed to evaluate the role of 4D-CT in pre-operative localization in patients with pHPT who are negative for ultrasonography (USG) and/or sestamibi single-photon emission computed tomography/CT (SPECT/CT) and will undergo primary surgery.

Methods

Patients whom were operated between 2018 and 2023 were included to this study. 4D-CT results of patients with one- or two-negative USG and SPECT/CT results were evaluated retrospectively.

Results

In this study, 19 patients (5 men and 14 women) with a mean age of 57.1±8.5 years were evaluated. Pathology results were consistent with parathyroid adenoma in 18 patients (94.7%) and parathyroid hyperplasia in 1 patient (5.3%). USG was negative in six patients, SPECT/CT was negative in 14 patients, and both were negative in four patients. In 4D-CT, positive images were detected in 15 patients and these results were finalized as true positive in 14 patients and false positive in 1 patient. The sensitivity of 4D-CT was 82.4% (95% CI: 60.4-95.3%), positive predictive value was 93.3% (95% CI: 73.8-99.6%), accuracy was 78.9%, and localization rate was 73.7%. In 14 (73.7%) patients, the pathological glands were removed by MIP.

Conclusion

In approximately 75% of patients with negative USG and/or SPECT/CT, the pathological gland can be localized with 4D-CT and MIP can be applied in these patients.