The impact of intraoperative neural monitoring during papillary thyroid cancer surgery on completeness of thyroidectomy and thyroglobulin response: a propensity-score matched study

BACKGROUND

Intraoperative neural monitoring (IONM) has been utilized for a variety of thyroid pathologies, including papillary thyroid carcinoma (PTC). Remnant thyroid tissue following total thyroidectomy (TT) in patients with PTC is associated with increased recurrence. The aim of this study is to investigate whether the use of IONM in PTC surgery has an impact on the completeness of thyroidectomy.

METHODS

Retrospectively, patients with preoperative diagnosis of PTC, who underwent TT in a tertiary center were reviewed. They were grouped based on the IONM usage, and 1:1 propensity-score match was performed. Primary outcome was the completeness of thyroidectomy, determined by measuring postoperative stimulated thyroglobulin levels (sTg).

RESULTS

Among 274 clinically node-negative PTC patients who underwent TT and ipsilateral prophylactic central lymph-node dissection, a total of 170 patients (85:85) were matched. Postoperative sTg levels were significantly lower in the IONM group (1 ng/dL vs. 0.4 ng/dL; p < 0.01) with higher percentage of the patients with sTg levels <1 ng/ml (50.6% vs. 69.4%; p = 0.01). More patients in the no-IONM group received RAI ablation with significantly higher doses (mean mci: 120 vs. 102; p = 0.02).

CONCLUSION

The use of IONM during thyroidectomy provides improvement in the completeness of thyroidectomy and reduction in postoperative sTg levels which can be used as a guide by clinicians to avoid RAI ablation in selected PTC patients and to adjust low ablative doses in patients who are scheduled for remnant ablation.

Artificial Intelligence in Minimally Invasive Adrenalectomy: Using Deep Learning to Identify the Left Adrenal Vein

BACKGROUND

Minimally invasive adrenalectomy is the main surgical treatment option for the resection of adrenal masses. Recognition and ligation of adrenal veins are critical parts of adrenal surgery. The utilization of artificial intelligence and deep learning algorithms to identify anatomic structures during laparoscopic and robot-assisted surgery can be used to provide real-time guidance.

METHODS

In this experimental feasibility study, intraoperative videos of patients who underwent minimally invasive transabdominal left adrenalectomy procedures between 2011 and 2022 in a tertiary endocrine referral center were retrospectively analyzed and used to develop an artificial intelligence model. Semantic segmentation of the left adrenal vein with deep learning was performed. To train a model, 50 random images per patient were captured during the identification and dissection of the left adrenal vein. A randomly selected 70% of data was used to train models while 15% for testing and 15% for validation with 3 efficient stage-wise feature pyramid networks (ESFPNet). Dice similarity coefficient (DSC) and intersection over union scores were used to evaluate segmentation accuracy.

RESULTS

A total of 40 videos were analyzed. Annotation of the left adrenal vein was performed in 2000 images. The segmentation network training on 1400 images was used to identify the left adrenal vein in 300 test images. The mean DSC and sensitivity for the highest scoring efficient stage-wise feature pyramid network B-2 network were 0.77 (±0.16 SD) and 0.82 (±0.15 SD), respectively, while the maximum DSC was 0.93, suggesting a successful prediction of anatomy.

CONCLUSIONS

Deep learning algorithms can predict the left adrenal vein anatomy with high performance and can potentially be utilized to identify critical anatomy during adrenal surgery and provide real-time guidance in the near future.

An unusual finding after adrenal surgery: a case series of adrenal schwannomas

Adrenal schwannomas are rare benign tumors with no specific imaging and laboratory findings to diagnose preoperatively. Due to the limited number of cases in the literature, clinical, imaging, and pathological findings are presented in this study. Case 1 is a 61-year-old woman patient who has a 31-mm mass in the right adrenal gland. This mass was nonfunctional; in imaging studies, this mass had a cystic necrotic component, and high 18-fluorodeoxyglucose (FDG) uptake was seen. There was no metaiodobenzylguanidine (MIBG) uptake. Laparoscopic transabdominal right adrenalectomy was performed, and the pathology result was consistent with adrenal schwannomas. Case 2 is a 63-year-old man patient who presented with a 38-mm mass in the left adrenal gland. This mass was nonfunctional and similar to that in Case 1; this mass had a cystic component. Laparoscopic transabdominal left adrenalectomy was performed. The diagnosis of adrenal schwannoma with degeneration was revealed. Case 3 was a 72-year-old woman patient admitted to the hospital for a 125-mm left adrenal mass. Similar to Case 1, this mass also had a cystic necrotic component in imaging studies. High FDG uptake was seen, and the patient underwent conventional adrenalectomy due to the suspicion of malignancy. After pathological evaluation, a diagnosis of adrenal schwannoma was made. A main diagnostic challenge in adrenal schwannomas is the preoperative diagnosis. These masses have no pathognomonic finding or specific hormonal function. Imaging findings of these masses may increase the suspicion of malignancy, which may affect decisions for surgery and the surgical technique.

DICER1 Mutations Occur in More Than One-Third of Follicular-Patterned Pediatric Papillary Thyroid Carcinomas and Correlate with a Low-Risk Disease and Female Gender Predilection

Some pediatric papillary thyroid carcinoma (PPTC) cohorts have suggested a preliminary correlation with respect to DICER1 mutation status and histomorphology in both benign and malignant follicular cell-derived nodules; however, the data regarding correlates of DICER1-related sporadic PPTCs subtyped based on the 2022 WHO classification criteria are largely unavailable. The current study investigated the status of hotspot DICER1 mutations with clinical, histological and outcome features in a series of 56 patients with PPTCs with no clinical or family history of DICER1-related syndromic manifestation. Fifteen (27%) PPTCs harbored BRAF p.V600E. Eight (14%) cases of PPTCs harbored DICER1 mutations with no associated BRAF p.V600E. DICER1 mutations were identified in exons 26 and 27. A novel D1810del (c.5428_5430delGAT) mutation was also detected. We also confirmed the absence of hotspot DICER1 mutations in the matched non-tumor tissue DNA in all 8 DICER1-related PPTCs. The mean age of DICER1-harboring PPTCs was 15.1 (range: 9-18) years whereas the rest of this cohort had a mean age of 14.8 (range 6-18) years. With the exception of one PPTC, all DICER1-related PPTCs were seen in females (female-to-male ratio: 7). The female to male ratio was 3.8 in 48 DICER1-wild type PPTCs. In terms of histological correlates, 5 of 8 (63%) DICER1-mutant PPTCs were invasive encapsulated follicular variant papillary thyroid carcinomas (FVPTCs) including 4 minimally invasive FVPTCs and 1 encapsulated angioinvasive FVPTC, whereas the remaining 3 PPTCs were infiltrative classic papillary thyroid carcinomas (p < 0.05). The incidence of DICER1 mutations was 19.5% in BRAF p.V600E-wild type PPTCs. Sixty-three percent of DICER1 hotspot mutations occurred in invasive encapsulated FVPTCs, and this figure represents 38% of invasive encapsulated FVPTCs. Only one (12%) patient with DICER1-related disease showed a single lymph node with micro-metastasis. Unlike DICER1-wild type patients, no distant metastasis is identified in patients with DICER1-related PPTCs. The current series expands on the surgical epidemiology of somatic DICER1-related PPTCs by correlating the mutation status with the clinicopathological variables. Our findings underscore that female gender predilection and enrichment in low-risk follicular-patterned PTCs are characteristics of DICER1-related PPTCs.

Is craniocaudal dissection of recurrent laryngeal nerve safer than lateral approach: a prospective randomized study comparing both techniques by using continuous intraoperative nerve monitoring

Purpose

This study was performed to compare the real-time electromyographic (EMG) changes and the rate of recurrent laryngeal nerve (RLN) injury in craniocaudal and lateral approaches for RLN during thyroidectomy.

Methods

One hundred twelve and 86 patients were prospectively randomized to receive lateral (group 1) or craniocaudal (group 2) approach to RLN, respectively, under continuous intraoperative nerve monitoring.

Results

Loss of signal (LOS) occurred in 7 (2.0%) of 356 nerves at risk (NAR). LOS was significantly associated with repeated adverse EMG changes and presence of RLN entrapment at the ligament of Berry (LOB), which was accompanied by other clinicopathological or anatomical features, such as tubercle of Zuckerkandl (TZ), extralaryngeal branching, hyperthyroidism, autoimmune thyroid disease (ATD), or thyroid lobe volume of >29 cm³ (P = 0.001 and P = 0.030, respectively). The rate of repeated adverse EMG changes and LOS in the NARs with LOB entrapment accompanied by other clinicopathological and anatomical features was higher in group 1 vs. group 2 (11.1% vs. 2.2%, respectively and 9.7% vs. 0%, respectively; P = 0.070). The total rate of vocal cord palsy (VCP) was significantly higher in group 1 than in group 2 (P = 0.005). The rate of permanent VCP showed no significant difference between the 2 groups.

Conclusion

The craniocaudal approach to the RLN is safer than the lateral approach in the RLNs with entrapment at the LOB accompanied by other features, such as TZ, extralaryngeal branching, hyperthyroidism, ATD, or high thyroid lobe volume.

Varied Recurrent Laryngeal Nerve Course Is Associated with Increased Risk of Nerve Dysfunction During Thyroidectomy: Results of the Surgical Anatomy of the Recurrent Laryngeal Nerve in Thyroid Surgery Study, an International Multicenter Prospective Anatomic and Electrophysiologic Study of 1000 Monitored Nerves at Risk from the International Neural Monitoring Study Group

Background: The recurrent laryngeal nerve (RLN) can be injured during thyroid surgery, which can negatively affect a patient's quality of life. The impact of intraoperative anatomic variations of the RLN on nerve injury remains unclear. Objectives of this study were to (1) better understand the detailed surgical anatomic variability of the RLN with a worldwide perspective; (2) establish potential correlates between intraoperative RLN anatomy and electrophysiologic responses; and (3) use the information to minimize complications and assure accurate and safe intraoperative neuromonitoring (IONM). Methods: A large international registry database study with prospectively collected data was conducted through the International Neural Monitoring Study Group (INMSG) evaluating 1000 RLNs at risk during thyroid surgery using a specially designed online data repository. Monitored thyroid surgeries following standardized IONM guidelines were included. Cases with bulky lymphadenopathy, IONM failure, and failed RLN visualization were excluded. Systematic evaluation of the surgical anatomy of the RLN was performed using the International RLN Anatomic Classification System. In cases of loss of signal (LOS), the mechanism of neural injury was identified, and functional evaluation of the vocal cord was performed. Results: A total of 1000 nerves at risk (NARs) were evaluated from 574 patients undergoing thyroid surgery at 17 centers from 12 countries and 5 continents. A higher than expected percentage of nerves followed an abnormal intraoperative trajectory (23%). LOS was identified in 3.5% of NARs, with 34% of LOS nerves following an abnormal intraoperative trajectory. LOS was more likely in cases of abnormal nerve trajectory, fixed splayed or entrapped nerves (including at the ligament of Berry), extensive neural dissection, cases of cancer invasion, or when lateral lymph node dissection was needed. Traction injury was found to be the most common form of RLN injury and to be less recoverable than previous reports. Conclusions: Multicenter international studies enrolling diverse patient populations can help reshape our understanding of surgical anatomy during thyroid surgery. There can be significant variability in the anatomic and intraoperative characteristics of the RLN, which can impact the risk of neural injury.

Management of endocrine surgical disorders during COVID-19 pandemic: expert opinion for non-surgical options

Purpose

The COVID-19 pandemic brought unprecedented conditions for overall health care systems by restricting resources for non-COVID-19 patients. As the burden of the disease escalates, routine elective surgeries are being cancelled. The aim of this paper was to provide a guideline for management of endocrine surgical disorders during a pandemic.

Methods

We used Delphi method with a nine-scale Likert scale on two rounds of voting involving 64 experienced eminent surgeons and endocrinologists who had the necessary experience to provide insight on endocrine disorder management. All voting was done by email using a standard questionnaire.

Results

Overall, 37 recommendations were voted on. In two rounds, all recommendations reached an agreement and were either endorsed or rejected. Endorsed statements include dietary change in primary hyperparathyroidism, Cinacalcet treatment in secondary hyperparathyroidism, alpha-blocker administration for pheochromocytoma, methimazole ± β-blocker combination for Graves’ disease, and follow-up for fine-needle aspiration results of thyroid nodules indicated as Bethesda 3–4 cytological results and papillary microcarcinoma.

Conclusion

This survey summarizes expert opinion for the management of endocrine surgical conditions during unprecedented times when access to surgical treatment is severely disrupted. The statements are not applicable in circumstances in which surgical treatment is possible.

Pure transoral robotic thyroidectomy; institutional adaptation and early results from a tertiary endocrine surgery centre

PURPOSE

Novel thyroidectomy techniques have been described to minimize the visible scar. Hereby, we aim to present our experience with transoral robotic thyroidectomy (TORT) without axillary access.

MATERIAL AND METHODS

Between August 2018 and March 2019, six eligible patients were enrolled to undergo TORT. Procedures were performed by using the Da Vinci Xi platform under intermittent intraoperative nerve monitoring.

RESULTS

All patients were female, and the mean age was 40.0 ± 14.4 years. Three patients underwent total thyroidectomy, and lobectomy was performed for the remaining three patients. In one patient, the procedure was converted to conventional open thyroidectomy due to bleeding. The mean docking time, console time and total operative time were 22.8 ± 5.2 min, 118.5 ± 48.7 min and 218.29 ± 50.6 min for total thyroidectomy and 21.8 ± 4.1 min, 68.6 ± 6.1 min and 177.6 ± 15.1 min for lobectomy, respectively. All patients were discharged uneventfully.

CONCLUSIONS

Pure TORT is a safe procedure, when performed in carefully selected patients by experienced surgeons, but further prospective studies with larger number of patients are required.

Multicentricity Is More Common in Thyroid Papillary Microcancer with a Preoperative Diagnosis Compared to Incidental Microcancer

OBJECTIVE

Although multicentricity is a common feature of thyroid papillary microcancer, it might be difficult to predict this histopathological feature preoperatively.

METHODS

The records of 306 papillary microcancer patients who underwent thyroidectomy were evaluated. Papillary microcancer was diagnosed as an incidental histopathological finding in 242 (group 1), and by preoperative fine-needle aspiration biopsy in 64 (group 2). Demographic data and histopathological features were compared between the two groups.

RESULTS

Age (44 ± 11.4 vs. 43 ± 14 years) and male/female ratio (44/193 vs. 12/52) showed no significant difference between groups 1 and 2 (p > 0.05). Mean tumor size was significantly larger in group 2 (5.2 ± 2.8 mm) compared to group 1 (3.7 ± 2.4 mm) (p = 0.004). The frequency of thyroid capsule invasion (44 vs. 19%, p = 0.0001), microscopic extrathyroidal invasion (25 vs. 10%, p = 0.004) and multicentricity (44 vs. 29%, p = 0.04), and bilateral lobar involvement (22 vs. 10%, p = 0.0001) was significantly higher in group 2 compared to group 1.

CONCLUSION

Multicentricity with bilateral lobar involvement and aggressive histopathological features are more frequent in papillary microcancer patients diagnosed with preoperative fine-needle aspiration biopsy compared to papillary microcancer diagnosed as postoperative incidental histopathological finding.

Classic Architecture with Multicentricity and Local Recurrence, and Absence of TERT Promoter Mutations are Correlates of BRAF (V600E) Harboring Pediatric Papillary Thyroid Carcinomas

This study is aimed to investigate the BRAF (V600E) and TERT promoter mutation profile of 50 pediatric papillary thyroid carcinomas (PTCs) to refine their clinicopathological correlates. The median age at the time of surgery was 16 years (range, 6-18). No TERT promoter mutations were identified in this series. The BRAF (V600E) mutation was present in 15 (30 %) tumors. From genotype-histologic variant correlation perspective, 13 of 24 classic variant PTCs and 2 of 7 diffuse sclerosing variant PTCs were found to harbor BRAF (V600E) mutation. One cribriform-morular variant, 3 solid variant, and 15 follicular variant PTCs were BRAF wild type. While tumors with distant metastasis were BRAF wild type, two of five tumors with extrathyroidal extension (ETE) harbored BRAF (V600E) mutation. Nine of 15 BRAF (V600E) harboring tumors had central lymph node metastases. There was no significant correlation with BRAF (V600E) mutation and age, gender, tumor size, ETE, central lymph node metastasis, the status of pT, pN1a-b, and distant metastasis. An adverse correlation between BRAF (V600E) mutation and disease-free survival (DFS) was noted in the entire cohort; however, the predictive value of BRAF (V600E) mutation disappeared within the group of tumors displaying classic architecture as well as classic variant PTCs. The present cohort identifies that the classic architecture with multicentricity and local recurrence are correlates of BRAF (V600E) harboring pediatric PTCs. While the small size of this cohort is one of the limitations, neither the BRAF mutation status nor the classic tumor architecture does seem to be an independent prognosticator of DFS in this series. Evidence also suggests that TERT promoter mutations do not seem to play a major role in the pathogenesis of pediatric PTCs.

Comparison of histopathological features and prognosis of classical and follicular variant papillary thyroid carcinoma

PURPOSE

To compare the histopathological features and the outcomes of the follicular variant and classical variant of papillary thyroid carcinoma.

MATERIAL AND THE METHODS

Demographic data, histopathological features (tumor size, thyroid capsule invasion, extrathyroidal extension, vascular invasion and multicentricity), lymph node metastasis, local recurrence, distant metastasis and mortality during the follow-up of 258 C-PTC and 153 FVPTC patients who underwent total thyroidectomy were compared. The dynamic risk assessment system was used to refine postoperative risk estimates based on the assessment of response to initial treatment.

RESULTS

The demographic data showed no significant difference between the two groups. The mean tumor size showed no significant difference between the two groups. The rate of thyroid capsule invasion, extrathyroidal extension, and lymph node metastasis was significantly higher in C-PTC than in FVPTC group, whereas multicentricity and bilobar involvement were significantly higher in FVPTC group than in C-PTC group. Central lymph node metastasis was significantly more frequent in patients with C-PTC than in those with FVPTC (p < 0.0001). Local recurrence was found in 22 (5.3 %) patients overall and was significantly more common in C-PTC group than in FVPTC group. In patients ≥45 years, the local recurrence rate was significantly higher in patients with CPTC than in those with FVPTC. The local recurrence rate in patients <45 years was not significantly different between the two groups of patients. The multicentricity rate was significantly higher in the FVPTC group for both age groups. Dynamic risk assessment showed that the rate of intermediate- and high-risk groups showed no significant difference between C-PTC and FVPTC patients but the rate of low risk patients was higher in FVPTC group than in C-PTC group (p = 0.04). The recurrence rate in low-risk group was found higher in C-PTC compared to FVPTC patients (4.7 vs. 0.7 %, p = 0.04, respectively). The recurrence rate showed no significant difference in both intermediate- and high-risk groups in C-PTC and FVPTC patients. During the follow-up, the rate of distant metastasis and disease-specific mortality was not significantly different between the two groups (p = 0.25).

CONCLUSION

FVPTC is a common subtype of PTC and has a higher rate of multicentricity with bilobar involvement. Although aggressive histopathologic features, such as thyroid capsule invasion, extrathyroidal extension, and lymph node metastasis, are significantly more frequent in CPTC than in FVPTC, the long-term outcome is similar in both subtypes after appropriate initial surgery and postoperative RAI ablation treatment.

Single-incision laparoscopic adrenalectomy

BACKGROUND

The aim of this study was to compare outcome measures between conventional transabdominal laparoscopic adrenalectomy and single-incision laparoscopic adrenalectomy (SILA).

METHODS

Between January 2006 and April 2010, a total of 96 patients underwent laparoscopic adrenalectomy. Of these, 74 (77.1%) underwent conventional transabdominal laparoscopic adrenalectomy (group 1) and 22 (32.9%) underwent SILA (group 2). Age, sex ratio, tumor size, operating time, blood loss, postoperative visual analog pain scale (VAS) scores, and duration of hospitalization were compared between the two groups.

RESULTS

The mean ages of the patients in groups 1 and 2 were 43.4 ± 12.3 and 43.3 ± 10 years, respectively (P = 0.7). The female:male ratios in groups 1 and 2 were 1.6:1 and 4.5:1, respectively (P < 0.0001). The mean tumor size was significantly larger in group 1 than in group 2 (4.7 ± 1.5 vs. 3.34 ± 1.06 cm, respectively; P = 0.093). No significant difference was found between group 1 and group 2 with respect to the mean operating time (68.4 ± 20.8 vs. 63.9 ± 16.9 min, respectively; P = 0.36) or the level of intraoperative blood loss (38 ± 26.5 vs. 48.4 ± 62.4 ml, respectively; P = 0.26). The postoperative VAS score was significantly lower in group 2 than in group 1 (2.05 ± 0.57 and 3.28 ± 0.63, respectively; P < 0.0001). The length of hospital stay was significantly higher in group 1 than in group 2 (3.04 ± 1.2 and 2.45 ± 0.96 days, respectively; P = 0.04).

CONCLUSION

The findings of the present study suggest that SILA is as safe as conventional transabdominal laparoscopic adrenalectomy. Furthermore, SILA is associated with less pain and better cosmesis than the conventional laparoscopic procedure.

Excision efficiency of radioguided occult lesion localization in reoperative thyroid and parathyroid surgery

BACKGROUND

The purpose of this study was to investigate the efficiency of a radioguided occult lesion localization technique in reoperative thyroid and parathyroid procedures in patients who had undergone previous neck exploration for thyroid or parathyroid disease.

METHODS

Twenty-one consecutive patients who were scheduled for reoperative thyroid or parathyroid surgery were studied. The indication for reoperation was recurrent papillary thyroid cancer (PTC) in eight patients, completion thyroidectomy for PTC in eight patients who had previously undergone a bilateral subtotal thyroidectomy, recurrent goiter in two patients, primary hyperparathyroidism in two patients, and recurrent parathyroid cancer in one patient. Ninety minutes before surgery, 0.1 mL of Technetium-99m (0.2 mCi)-labeled macroaggregated albumin was injected directly into the lesion under ultrasonographic guidance. During surgery, a handheld gamma probe was used to localize and excise the lesions. The background and postexcisional site radioactivities were compared to confirm the completeness of each procedure. The radiation dose in the operating room environment, duration of surgery, and postoperative complication rates were evaluated in all patients. In patients with PTC, the change in serum thyroglobulin (Tg) following surgery was noted.

RESULTS

Thirty lesions were marked and excised. The postexcisional bed gamma counts (610 ± 141) were markedly decreased compared with the pre-excisional site counts (21,415.8 ± 4993.4; p = 0.0001). The ratio of the postexcisional and background counts (4.6 ± 4.3) was significantly lower than the ratio of the pre-excisional and background counts (173.7 ± 156.4; p = 0.0001). The mean operation duration was 53.3 ± 7.5 minutes. The dose absorbed by the hands of the surgeon was estimated as 0.07 ± 0.02 and 0.15 ± 0.05 millisievert/h when one or three lesions were marked, respectively. One patient developed postoperative transient hypoparathyroidism. After surgery, serum Tg levels dropped to <2 ng/mL in 86% (6/7) of the patients with PTC whose preoperative serum Tg was elevated.

CONCLUSIONS

The radioguided occult lesion localization technique was efficient in the perioperative identification of thyroid and parathyroid tumors in patients who were undergoing reoperation for PTC and hyperparathyroidism.