Expansion of thyroid surgical territory through 10,000 cases under the da Vinci robotic knife

With the progress of robotic transaxillary thyroid surgery (RTTS), the indications for this procedure have gradually expanded. This study presents the insights gained from performing 10,000 RTTS cases at a single institution, along with the expansion of indications over time. RTTS was performed on 10,000 patients using the da Vinci robot system between October 2007 and April 2023 at the Yonsei University Health System, Seoul, Korea. Among 10,000 patients, 9461 (94.0%) were diagnosed with thyroid cancer, whereas 539 (5.4%) had either a benign thyroid nodule or Graves' disease. Surgical procedures were performed using four-arm-based robots (da Vinci S, Si, or Xi) for 8408 cases (84.1%), with the remaining 1592 cases (15.9%) being performed using the da Vinci SP surgical robotic system. Notably, for 53 patients with nodules ≥ 5 cm, which were not included in the eligibility criteria of the previous study, RTTS was performed safely without significant complications. The most common postoperative complication was transient hypoparathyroidism (37.91%), and recurrence occurred in 100 patients with thyroid cancer (1.1%). In conclusion, RTTS appears safe and feasible from both surgical and oncological perspectives, and the spectrum of indications suitable for RTTS surgery is progressively expanding.

Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

Background

Fine-needle aspiration biopsy (FNAB) is a good diagnostic tool for thyroid nodules; however, its high false-negative rate for giant nodules remains controversial. Many clinicians recommend surgical resection for nodules >4 cm owing to an increased risk of malignancy and an increased false-negative rate. This study aimed to examine the feasibility of this approach and investigate the incidence of malignancy in thyroid nodules >4 cm without suspicious cytology based on medical records in our center.

Methods

This was a retrospective analysis of 453 patients that underwent preoperative FNAB for nodules measuring >4 cm between January 2017 and August 2022 at Severance Hospital, Seoul.

Results

Among the 453 patients, 140 nodules were benign and 119 were indeterminate. Among 259 patients, the final pathology results were divided into benign (149) and cancerous (110) groups, and the prevalence of malignancy was 38.9% in the benign group and 55.5% in the indeterminate group. Among the malignancies, follicular carcinoma and follicular variants of papillary carcinoma were observed in 83% of the cytologically benign group and 62.8% of the indeterminate group.

Conclusion

Preoperative FNAB had high false-negative rates and low diagnostic accuracy in patients with thyroid nodules >4 cm without suspicious cytologic features; therefore, diagnostic surgery may be considered a treatment option.

Single-Port Transaxillary Robotic Modified Radical Neck Dissection (STAR-RND): Initial Experiences

OBJECTIVES

This study aimed to demonstrate the usefulness of single-port transaxillary robotic modified radical neck dissection (STAR-RND) for metastatic thyroid cancer, and its potential to make small and invisible surgical wounds possible compared to open modified radical neck dissection.

METHODS

Between January 2020 and July 2021, 30 thyroid cancer patients who underwent lateral neck dissection surgery with the da Vinci SP at Yonsei University Health System (Seoul, Korea) were studied.

RESULTS

All 30 patients, diagnosed with papillary thyroid cancer were women. The average operating time was 293.80 ± 36.58 (min), and the average postoperative hospital stay was 4.77 ± 0.57 (days). All patients were discharged after the expected number of hospitalization days without major complications.

CONCLUSION

STAR-RND is technically feasible and safe with a short length of the incision. To our knowledge, this is the first report on the use of a single-port robotic system for modified radical neck dissection. LEVEL OF EVIDENCE BY USING 2011 OCEBM: 4 Laryngoscope, 133:709-714, 2023.

Efficacy and safety of temperature-sensitive acellular dermal matrix in prevention of postoperative adhesion after thyroidectomy: A randomized, multicenter, double-blind, non-inferiority study

Introduction

MegaShield^® is a newly developed temperature-sensitive anti-adhesive containing micronized acellular dermal matrix. The aim of this study was to investigate the efficacy and safety of MegaShield^® compared with Guardix-SG^® in the prevention of adhesions in patients undergoing bilateral total thyroidectomy.

Method

We conducted a multicenter trial between October 2018 and March 2020 in patients undergoing total thyroidectomy. The patients were randomly assigned to either the MegaShield^® group or the Guardix-SG^® group. The primary outcome was the esophageal movement using marshmallow six weeks after the surgery and the secondary outcome was the assessed adhesion score. The safety assessment was also evaluated.

Results

The study included 70 patients each in the MegaShield^® and control (Guardix-SG^®) groups. Baseline clinical characteristics, the mean score of marshmallow esophagography, and the sum of adhesion scores were not statistically different between the two groups. Inferiority test demonstrated that the efficacy of MegaShield^® is not inferior to that of Guardix-SG®. There were no device-related complications in both groups.

Conclusion

The efficacy and safety of MegaShield^® were not inferior than those of Guardix-SG^®. MegaShield^® demonstrated the potential of ADM as a potential future anti-adhesive agent.

Trial registration

The name of trial registry CRIS (Clinical Research Information Service) https://cris.nih.go.kr/cris/index.jsp. (The full trial protocol can be accessed) Registration number: KCT0003204.

Thyroid lobectomy is sufficient for differentiated thyroid cancer with upgraded risk after surgery

Background

It is difficult to reliably distinguish between American Thyroid Association (ATA) low-risk and intermediate-risk differentiated thyroid cancer (DTC) before surgery. Therefore, physicians are faced with a dilemma regarding the necessity and timing of completion total thyroidectomy (CT) after thyroid lobectomy (TL). We evaluated proper surgical methods by analyzing oncologic outcomes of TL in patients with DTC whose risk had been upgraded after surgery.

Methods

We retrospectively reviewed the medical records of 1,702 patients with DTC who underwent TL and ipsilateral central lymph node (LN) dissection between January 2006 and December 2011. The patients were classified into Group A (n=1,159; low risk; ≤5 central LN metastases or the absence of pathologic microscopic capsular invasion) and Group B (n=543; upgraded intermediate risk after surgery; >5 central LN metastases or the presence of pathologic microscopic capsular invasion). We analyzed their clinicopathological characteristics and recurrence-free survival.

Results

All 32 patients who experienced recurrence underwent CT. After the first operation, the duration until reoperation in Groups A and B were 8.00±2.74 (range, 3.42–12.17) and 5.10±3.09 (range, 1.25–11.67) years, respectively. There was no significant difference in recurrence rates, disease-related mortality rates, or 10-year recurrence-free survival rates between the two groups. The mean follow-up durations in Groups A and B were 10.22±1.58 and 10.13±1.47 years, respectively. Univariate analysis showed that sex, age, tumor size, multifocality, extrathyroidal extension (ETE), and number of central LN metastases were not associated with recurrence after TL, although the rate of central LN metastases was. Multivariate analysis showed that sex, age, tumor size, multifocality, ETE, central LN metastases, and the number of central LN metastases were not associated with recurrence after TL, although multifocality was.

Conclusions

TL with prophylactic central compartment neck dissection (CCND) is sufficient for patients with DTC whose risk is upgraded after surgery because they have a good prognosis at long-term follow-up. Larger-scale randomized clinical trials are required to confirm our findings.

Predictive Factors Indicative of Hemithyroidectomy and Close Follow-Up versus Bilateral Total Thyroidectomy for Aggressive Variants of Papillary Thyroid Cancer

Simple Summary

This study evaluated the need for additional surgical treatment in patients diagnosed with aggressive variants of papillary thyroid cancer after lobectomy. With the increase in the frequency of early diagnosis, the detection of papillary thyroid cancer pathologically belonging to the aggressive variant is also increasing. Therefore, there is growing concern regarding the aggressive treatment of encapsulated aggressive variants of papillary thyroid cancer without invasive features. We suggest that close follow-up can be performed without any additional surgical treatment in patients with low-risk aggressive variants of papillary thyroid cancer incidentally detected after hemithyroidectomy. The patients should be provided sufficient consultation with clinicians.

Abstract

The diagnostic and treatment rates of early thyroid cancer have been increasing, including those of aggressive variants of papillary thyroid cancer (AVPTC). This study aimed to analyze the need for completion total thyroidectomy after lobectomy for clinically low-to-intermediate-risk AVPTC. Overall, 249 patients who underwent hemithyroidectomy (HT, n = 46) or bilateral total thyroidectomy (BTT, n = 203) for AVPTC between November 2005 and December 2019 at our single institution were examined. The average follow-up period was 14.9 years, with a recurrence rate of 4.3% and 10.8% in the HT and BTT groups, respectively. Multivariate Cox analysis revealed that palpable tumor on the neck during evaluation (HR, 2.7; 95% CI, 1.1–6.4; p = 0.025), clinical N1b (HR, 8.3; 95% CI, 1.1–63.4; p = 0.041), tumor size (cm) (HR, 1.3; 95% CI, 1.0–1.7; p = 0.036), gross extrathyroidal extension (HR, 3.1; 95% CI, 1.4–7.0; p = 0.007), and pathologic T3b (HR, 3.4; 95% CI, 1.0–11.4; p = 0.045) or T4a (HR, 6.0; 95% CI, 1.9–18.8; p = 0.002) were associated with an increased risk of recurrence. Incidentalomas identified during diagnosis had a significantly lower risk of recurrence (HR, 0.4; 95% CI, 0.2–0.9; p = 0.033). Close follow-up may be performed without completion total thyroidectomy for AVPTC found incidentally after HT.

Comparisons Between Normocalcemic Primary Hyperparathyroidism and Typical Primary Hyperparathyroidism

BACKGROUND

Normocalcemic primary hyperparathyroidism (NPHPT) was first described in 2008. It is defined as consistently elevated serum parathyroid hormone (PTH) levels with normal serum calcium (sCa) concentration, after excluding secondary causes of PTH elevation. However, the exact definition and management strategy for NPHPT remain controversial. We retrospectively investigated the clinicopathological features and short-term outcomes of NPHPT patients.

METHODS

A total of 280 patients who were surgically indicated for primary hyperparathyroidism (PHPT) at the Yonsei Severance Medical Center between 2015 and 2019 were included. Patients were classified according to preoperative PTH, corrected sCa, and ionized calcium (iCa) levels as follows: typical primary hyperparathyroidism (TPHPT, elevated PTH, sCa, and iCa, n = 158) and NPHPT (elevated PTH, normal sCa, n = 122).

RESULTS

NPHPT was commonly seen in younger individuals (aged < 50 years, P = 0.025); nephrolithiasis and bone fractures were common. Preoperative PTH level was higher in the TPHPT group (P < 0.001). The NPHPT group had higher numbers of multiple parathyroid lesions (P = 0.004) that were smaller (P = 0.011). NPHPT patients were further divided into two subgroups according to iCa levels: the elevated (n = 95) and normal iCa (n = 27) groups. There was no significant difference between the two subgroups regarding symptoms and multiplicity of lesions.

CONCLUSION

We found that NPHPT may be a heterogeneous disease entity of PHPT with high rates of multi-gland disease, which appears to be biochemically milder but symptomatic. Intraoperative PTH monitoring might help increase the surgery success rate. Moreover, the short-term outcomes of NPHPT after surgery did not differ from that of TPHPT.

Analysis of the cause and management of persistent laboratory abnormalities occurring after the surgical treatment of primary hyperparathyroidism

Purpose

The surgical success rate for primary hyperparathyroidism (PHPT) is currently 95%–98%. However, 3%–24% of patients show persistently elevated (Pe) parathyroid hormone (PTH) levels after parathyroidectomy (PTX). This single-center retrospective study aimed to compare the outcomes of patients with normal PTH and PePTH levels after successful PTX and to identify the factors associated with PePTH.

Methods

The normal group, defined as patients with normal serum calcium and PTH levels immediately after PTX, was compared with the PePTH group (patients with normal or low serum calcium and increased serum PTH levels up to 6 months postoperatively) to determine the causes of disease in the PePTH group.

Results

There were no significant differences in age, sex, or preoperative estimated glomerular filtration rate between the normal PTH group (333 of 364, 91.5%) and the PePTH group (31 of 364, 8.5%). However, there were significant differences in preoperative 25-hydroxyvitamin D (17.9 and 11.8 ng/mL, respectively; P = 0.003) and PTH levels (125.5 and 212.4 pg/mL, respectively; P < 0.001) between the 2 groups. Among the 31 cases of the PePTH group, 18 were attributed to vitamin D deficiency.

Conclusion

Preoperative vitamin D deficiency is a predictive factor for PePTH. Therefore, preoperative administration of vitamin D supplements may reduce the probability of postoperative disease persistence. Patients with temporary laboratory abnormalities within 6 months after successful PTX should be monitored, and appropriate vitamin D and calcium supplementation may reduce the effort and cost of various examinations or reoperations.

Single-port transaxillary robotic thyroidectomy (START): 200-cases with two-step retraction method

Background

This study aims to report the results of a pioneering clinical study using the single-port transaxillary robotic thyroidectomy (START) for 200 patients with thyroid tumor and to introduce our novel two-step retraction method.

Methods

START was performed on consecutive 200 patients using the da Vinci Single-Port (SP) robot system from January 2019 to September 2020 at the Yonsei University Health System, Seoul, Korea. The novel two-step retraction technique, in which a 3.5 cm long incision is made along the natural skin crease, was used for the latter 164 patients. The surgical outcome and invasiveness of the SP two-step retraction method were analyzed.

Results

Among the 200 cases who underwent START, 198 were female and 2 were male, with a mean age of 34.7 (range: 13–58 years). Thyroid lobectomy was performed for 177 patients and total thyroidectomy was performed for 23 patients. Ten patients had benign thyroid nodules, whereas the other 190 had thyroid malignancy. The mean body mass index (BMI) was 22.2 ± 3.7 kg/m² (range: 15.9–37.0 kg/m²). All of the operations were performed successfully without any open conversions, and patients were discharged on postoperative day 3 or 4 without significant complication. The mean operative time for thyroid lobectomy with the two-step retraction method was 116.69 ± 23.23 min, which was similar to that in the conventional robotic skin flap method (115.33 ± 17.29 min). We could minimize the extent of the robotic skin flap dissection with the two-step retraction method.

Conclusions

START is a practical surgical method. By employing the new two-step retraction method, we can maximize the cosmetic and functional benefits for patients and reduce the workload fatigue of surgeons by increasing robotic dependency.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-021-08837-9.

Laparoscopic adrenalectomy: comparison of outcomes between posterior retroperitoneoscopic and transperitoneal adrenalectomy with 10 years' experience

Background

Laparoscopic adrenalectomy is widely used for treating various adrenal tumors. Posterior retroperitoneoscopic adrenalectomy was introduced after transperitoneal laparoscopic adrenalectomy. The comparability and superiority of posterior retroperitoneoscopic adrenalectomy have been widely investigated. We aimed to compare the outcomes of posterior retroperitoneoscopic adrenalectomy and transperitoneal laparoscopic adrenalectomy using 10 years' data. The changes in outcomes over time were also analyzed.

Methods

This was a retrospective observational study. A total of 505 patients who underwent laparoscopic adrenalectomy between 2009 and 2018 were included. The patients were divided into two groups: transperitoneal (n=114) and retroperitoneal (n=391) groups. Patients who underwent posterior retroperitoneoscopic adrenalectomy were further classified into sub-groups (sub-group 1: 2009-2012; sub-group 2: 2013-2015; and sub-group 3: 2016-2018) based on time periods. Clinicopathological factors and postoperative outcomes were retrospectively reviewed and analyzed.

Results

The retroperitoneal group showed significantly shorter operation time, diet initiation time, and hospital stay compared to the transperitoneal group (P=0.000, 0.000 and 0.000, respectively). Analgesics were used less frequently in the retroperitoneal group than in the transperitoneal group (P=0.048). In the retroperitoneal group, the time to postoperative diet initiation shortened over time (P=0.000).

Conclusions

Posterior retroperitoneoscopic adrenalectomy is a favorable surgical method that results in patient outcomes that are comparable to those of conventional transperitoneal laparoscopic adrenalectomy, without compromising patient safety.

Thyroid nodules in xeroderma pigmentosum patients: a feature of premature aging

PURPOSE

Xeroderma pigmentosum (XP) is an autosomal recessive disease with defective DNA repair, a markedly increased risk of skin cancer, and premature aging. Reports from North Africa have described thyroid nodules in XP patients, but thyroid nodule prevalence has never been determined in XP patients enrolled in our natural history study at the National Institutes of Health (NIH).

METHODS

We performed thyroid ultrasound examinations on all 29 XP patients examined from 2011 to 2019 and assessed nodule malignancy using the Thyroid Imaging Reporting and Data System. Thyroid nodule prevalence was also obtained from comparison cohorts. DNA sequencing was performed on thyroid tissue from XP patients who had surgery for thyroid cancer.

RESULTS

Thyroid nodules were identified in 18/29 XP patients (62%). The median age of patients with thyroid nodules in our XP cohort (20 years) was younger than that of three comparison groups: 36 years (California study-208 subjects), 48 years (Korean study-24,757 subjects), and 52 years (NIH-682 research subjects). Multiple (2-4) thyroid nodules were found in 12/18 (67%) of the patients with nodules. Autopsy examination revealed follicular adenomas in 4/8 (50%) additional XP patients. DNA sequencing revealed rare mutations in two other XP patients with papillary thyroid cancer.

CONCLUSIONS

XP patients have an increased incidence of thyroid nodules at an early age in comparison to the general population. These finding confirm another premature aging feature of XP.

Miliary fibromas in tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a hamartoma syndrome characterized by multiple skin lesions, such as angiofibromas, shagreen patch and miliary fibromas (MiF).

OBJECTIVE

To determine the clinical and histological features of MiF.

METHODS

A retrospective analysis was conducted on 133 adults with TSC. Photography was used to characterize the appearance and location of MiF. Histological features in five skin samples from four individuals were evaluated by a board-certified dermatopathologist.

RESULTS

MiF were observed in 19 of 133 (14%) individuals with TSC. MiF were 1- to 3-mm skin-coloured, sessile papules scattered on the back and rarely buttocks or thighs. Most were scattered in a bilaterally symmetric distribution, but others were asymmetric or associated with a shagreen patch. Histological features of MiF included expansion of the papillary and periadnexal dermis with variable hamartomatous abnormalities involving adjacent epithelial components.

CONCLUSIONS

MiF are distinct from other cutaneous lesions in TSC such as shagreen patches and angiofibromas. Recognition of this entity is important in defining the spectrum of TSC disease and reassuring individuals with TSC that these lesions are benign.

Clinical Utility of Preoperative Vitamin D3 Injection for Preventing Transient Hypocalcemia after Total Thyroidectomy

BACKGROUND

Postoperative transient hypocalcemia (TH) is a common complication of total thyroidectomy. This retrospective study evaluated the clinical utility of preoperative vitamin D3 injection for the prevention of TH after total thyroidectomy.

METHODS

We included 2294 patients who underwent total thyroidectomy from January 2015 until October 2018 and retrospectively analyzed their data by complete chart review at our hospital. The patients were divided into two groups: vitamin D3 injection (VDI; n = 342) and vitamin D3 noninjection (VDN; n = 1952). TH was defined as serum calcium <8.2 mg/dL and signs or symptoms of hypocalcemia.

RESULTS

The mean preoperative serum 25-hydroxyvitamin D (25-OHD) levels of the VDI group were significantly lower than those of the VDN group (16.5 ± 6.9 ng/mL vs 19.4 ± 8.7 ng/mL, p < 0.001). Multivariate analysis indicated that the significant risk factors of TH include vitamin D noninjection (hazard ratio (HR): 1.717, 95% confidence interval (CI): 1.282-2.300, p < 0.001), male gender (HR: 1.427, 95% CI: 1.117-1.822, p = 0.004), and capsular extension (HR: 1.273, 95% CI: 1.011-1.603, p = 0.040).

CONCLUSIONS

Preoperative vitamin D3 injection significantly contributed to the prevention of TH after total thyroidectomy. Further prospective or multicenter studies must be conducted to determine the effect of vitamin D3 injection.

Long-term outcomes of abdominal paraganglioma

Purpose

Paragangliomas (PGL) are rare neuroendocrine tumors derived from chromaffin cells of the autonomic nervous system. We aim to describe our experience and the long-term outcome of abdominal PGL over the last decade.

Methods

A retrospective review of patients diagnosed with PGL in our hospital between November 2005 and June 2017 was conducted. All nonabdominal PGL were excluded and the clinicopathological features and long-term outcomes of the patients were analyzed.

Results

A total of 46 patients were diagnosed with abdominal PGL. The average age of diagnosis was 55.4 years and there was no sex predilection. The average tumor size was 5.85 cm and they were predominantly located in the infrarenal position (50%). The mean follow-up period was 42 months (range, 1.8–252 months). All patients with metastases had Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) of ≥4. One patient presented with synchronous metastases while 2 developed local recurrence and distant metastases. One presented with only local recurrence. One patient died 5 years after diagnosis.

Conclusion

Abdominal PGL is a rare tumor with excellent long-term prognosis. Recurrence although uncommon, can occur decades after initial diagnosis. Long-term follow-up is therefore recommended for all patients with PGL, especially in patients with PASS of ≥4.

Surgical outcomes of minimally invasive thyroidectomy in thyroid cancer: comparison with conventional open thyroidectomy

Background

Minimally invasive thyroidectomy (MIT) is a safe method of performing thyroidectomy with notable benefits, such as improved cosmesis and reduced postoperative pain. The objective of this retrospective study was to report our experience with the technical feasibility of MIT, and compare its early surgical outcomes with those of conventional open thyroidectomy (COT) in patients with differentiated thyroid carcinoma (DTC).

Methods

A total of 617 patients who underwent MIT and 2,674 patients who underwent COT were reviewed between March 2006 and November 2017 at Yonsei University (Seoul, Korea). The mean follow-up duration was 41.2±19.7 months.

Results

The mean age of patients with DTC was 46.1±11.2 years. The mean operation time in the MIT group was significantly shorter than that of the COT group (63.5±26.2 vs. 85.3±36.8 minutes, P<0.001). The mean hospital stay was significantly shorter in the MIT group than it was in the COT group as well (2.7±0.6 vs. 3.1±0.8 days, P<0.001). There were significantly fewer painkillers used after surgery in the MIT group than in the COT group (1.2±0.5 vs. 2.7±1.6, P<0.001). The mean number of harvested LNs in the MIT group was significantly lower than that of the COT group (3.1±2.6 vs. 5.5±4.0, P<0.001).

Conclusions

This study demonstrated that MIT is technically feasible in patients with DTC. MIT is a valuable alternative operative technique to COT with good surgical outcomes and outstanding cosmetic results.

Correction to: Clinical Assessment of Pediatric Patients with Differentiated Thyroid Carcinoma: A 30-Year Experience at a Single Institution

The article "Clinical Assessment of Pediatric Patients with Differentiated Thyroid Carcinoma: A 30-Year Experience at a Single Institution", written by Kim et al., was originally published electronically on the publisher's internet portal (currently SpringerLink) on May 21, 2020, with open access. With the authors' decision to step back from Open Choice, the copyright of the article changed on September 14, 2020 to © Société Internationale de Chirurgie 2020 and the article is forthwith distributed under the terms of copyright. The original article has been corrected.

The contributing factors for lateral neck lymph node metastasis in papillary thyroid microcarcinoma (PTMC)

PURPOSE

Papillary thyroid microcarcinoma (PTMC) has an excellent prognosis due to its indolent features. Only few studies have assessed the clinical factors that can predict lateral neck lymph node metastasis (LLNM) in patients with PTMC. This study aimed to examine the clinicopathological factors associated with LLNM in patients with PTMC.

METHODS

We reviewed medical records of 3578 patients with PTMC that was ≤1 cm in diameter on final pathology at Yonsei University Hospital between January 2015 and December 2017. The patients were divided into two groups (metastasis group [n = 157] and no metastasis group [n = 3421]).

RESULTS

The proportion of patients with multifocality, extrathyroidal extension (ETE), and central node metastasis was significantly higher in metastasis group (p < 0.001, p < 0.001 and p < 0.001, respectively), and the mean tumor size was relatively larger in metastasis group than in no metastasis group (0.7 ± 0.2 vs. 0.6 ± 0.2 cm, p < 0.001). However, no statistically significant differences were observed in the tumors harboring BRAF mutation between the two groups (84.8% vs. 80.6%, p = 0.199). Multivariate analysis indicated that the significant risk factors of LLNM include ETE (odds ratio [OR]: 1.904, 95% confidence interval [CI]: 1.267-2.861), multifocality (OR: 2.255, 95% CI: 1.544-3.293), and central node metastasis (OR: 7.768, 95% CI: 4.869-12.395), but not BRAF mutation (OR: 0.542, 95% CI: 0.337-0.874).

CONCLUSION

Approximately 4.4% of patients with PTMC presented with LLNM at the time of diagnosis. Moreover, the significant risk factors of LLNM include central node metastasis, ETE, and multifocal disease but not BRAF mutation.

Benefit of diverse surgical approach on short-term outcomes of MEN1-related hyperparathyroidism

Surgical excision is the preferred treatment for multiple endocrine neoplasia type 1 (MEN1)-related primary hyperparathyroidism (PHPT), although controversy regarding the surgical strategy exists. We retrospectively investigated the short-term outcomes of PHPT by various surgical extents. Thirty-three patients who underwent parathyroidectomy due to MEN1-related PHPT at Yonsei Severance Hospital between 2005 and 2018 were included (age [mean ± SD], 43.4 ± 14.1 [range, 23–81] years). Total parathyroidectomy with auto-transplantation to the forearm (TPX) was the most common surgical method (17/33), followed by less-than-subtotal parathyroidectomy (LPX; 12/33) and subtotal parathyroidectomy (SPX; 4/33). There was no postoperative persistent hyperparathyroidism. Recurrence was high in the LPX group without significance (1 in TPX, 2 in SPX, and 3 in LPX, p = 0.076). Permanent and transient hypoparathyroidism were more common in TPX (n = 6/17, 35.3%, p = 0.031; n = 4/17, 23.5%, p = 0.154, respectively). Parathyroid venous sampling (PVS) was introduced in 2013 for preoperative localisation of hyperparathyroidism at our hospital; nine among 19 patients operated on after 2013 underwent pre-parathyroidectomy PVS, with various surgical extents, and no permanent hypoparathyroidism (p = 0.033) or post-LPX recurrence was observed. Although TPX with auto-transplantation is the standard surgery for MEN1-related PHPT, surgical extent individualisation is necessary, given the postoperative hypoparathyroidism rate of TPX and feasibility of PVS.

Cystic Lateral Lymph Node Metastases From Papillary Thyroid Cancer Patients

OBJECTIVES/HYPOTHESIS

Papillary thyroid carcinoma (PTC) tends to metastasize rather early to local lymph nodes (LNs). Incidences of cystic LN metastases is relatively rare compared with that of solid LN metastases. Few studies have attempted to assess the characteristics in these patients. This study aimed to compare the clinicopathologic characteristics and surgical outcomes between patients with cystic LN metastases and those with solid LN metastases.

STUDY DESIGN

Retrospective cohort study.

METHODS

We retrospectively reviewed the data of 1,028 patients with N1b PTC who underwent bilateral total thyroidectomy with central compartment neck dissection and modified radical neck dissection between January 2005 and September 2011. Of these, 136 (13.2%) had cystic LN metastases and 892 (86.8%) had solid LN metastases. Clinicopathologic characteristics and surgical outcomes were compared between these two patient groups.

RESULTS

The proportion of patients with thyroid tumor multifocality was relatively higher in the cystic node cohort (19.9% vs. 12.7%, P = .048). The number of total metastatic LNs and positive lateral LNs was slightly higher in the cystic node cohort (11.3 ± 8.9 vs. 9.7 ± 7.5, P = .029 and 6.9 ± 6.3 vs. 5.5 ± 4.6, P = .018, respectively). The proportion of patients with recurrence was higher in the cystic node cohort (14.0% vs. 3.0%, P < .001). Multivariate analysis indicated that cystic nodes were a significant risk factor for recurrence (hazard ratio: 5.265, 95% confidence interval: 2.898-9.563).

CONCLUSIONS

This study demonstrates that cystic lateral LN metastases are associated with aggressive tumor behavior in PTC patients. and that their presence is a significant independent prognostic factor for disease-free survival.

LEVEL OF EVIDENCE

2b Laryngoscope, 2020.

Robotic Transaxillary Hemithyroidectomy Using the da Vinci SP Robotic System: Initial Experience With 10 Consecutive Cases

Background: Many studies have shown the operative feasibility and safety of robotic thyroidectomy. However, there is still a concern on the operative invasiveness of robotic thyroidectomy owing to the wide flap dissection. The aim of this study was to introduce our novel robotic technique, which can minimize the dissection extent using the da Vinci SP robotic system. Methods: Ten patients underwent robotic transaxillary thyroidectomy using the da Vinci SP robotic system between December 2018 and April 2019 at Yonsei University Hospital (Seoul, Korea). All procedures were performed successfully using the single-port robotic system. Results: All 10 patients were women and diagnosed with papillary thyroid carcinoma. The mean operative time was 148.7 ± 26.8 minutes. The mean operative time using the gasless method was shorter than that using the gas insufflation method (130.5 ± 14.1 vs 176.0 ± 12.8 minutes). All patients were discharged on the third day after operation without any complications. Conclusions: Robotic transaxillary thyroidectomy using the da Vinci SP robotic system is technically feasible and safe with a short length of incision, shorter than what earlier reported. To our knowledge, this is the first study to use a single-port robotic system for thyroidectomy. To verify the superior operative outcomes, further clinical trials are necessary.

Hemodynamic stability during adrenalectomy for pheochromocytoma: A case control study of posterior retroperitoneal vs lateral transperitoneal approaches

Hemodynamic stability is one of the most critical aspects of adrenal surgery for pheochromocytoma. Few articles have evaluated the hemodynamic status of patients undergoing posterior retroperitoneal adrenalectomy (PRA) for pheochromocytoma. The aim of this study is to compare the intraoperative hemodynamic parameters between lateral transperitoneal adrenalectomy (TPA) and PRA in this groups of patients.This report describes a retrospective study of 53 pheochromocytoma patients who underwent endoscopic adrenalectomy via transperitoneal (22 patients) or posterior retroperitoneal (31 patients) approaches from January 2008 to March 2015. Data from these patients were compared to investigate the differences in hemodynamic parameters between the 2 approaches.Clinical parameters at presentation were similar between the 2 groups, except for tumor size, which was larger in the TPA group. The PRA group is associated with reduced operative time, blood loss, and length of hospital stay compared to TPA even after adjusting for the tumor size. There was greater BP fluctuations and higher maximum systolic and diastolic blood pressure (BP) within the TPA group compared to PRA during univariate analysis. This was however not significant after adjusting for tumor size. There was no difference in the intraoperative inotropic support requirement between the 2 groups.PRA is associated with stable intraoperative hemodynamic status, as well as favorable perioperative outcomes compared to TPA in patients with small pheochromocytomas.

Comparison of long-term prognosis for differentiated thyroid cancer according to the 7th and 8th editions of the AJCC/UICC TNM staging system

BACKGROUND

The 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumor-node-metastasis (TNM) staging system was released with major revisions. The purpose of this retrospective study was to investigate differences between the 7th and 8th editions of the AJCC/UICC TNM staging system and to compare the predictability of prognosis between the two staging systems with patients who underwent thyroidectomy for differentiated thyroid cancer (DTC) at a single institution.

METHODS

A total of 3238 patients underwent thyroid operation from January 2002 to December 2006 at Yonsei University Hospital (Seoul, Korea), of which 2294 with complete clinical data and sustained follow up were enrolled. Clinicopathologic features and TNM staging by applying the 7th and 8th editions of the AJCC/UICC were analyzed retrospectively by the complete review of medical charts and pathology reports of patients. Mean follow-up duration was 132.9 ± 27.9 months.

RESULTS

A significant number of T3 patients were downstaged to T1 (838, 36.5%) and T2 (122, 5.3%). After applying the 8th edition of the AJCC/UICC TNM staging system, the number of stage I patients increased significantly from 1434 (62.5%) to 2058 (89.7%), whereas numbers of stage III and IV patients decreased significantly from 644 (28.1%) to 33 (1.4%) and from 199 (8.7%) to 17 (0.7%), respectively. According to Kaplan-Meier survival analyses and values of the Harrell's c-index and integrated area under the curve (iAUC), the 8th edition has significantly better predictive performance for disease-free survival (DFS) and disease-specific survival (DSS) than the 7th edition.

CONCLUSIONS

A significant population was downstaged after applying the 8th edition of the AJCC/UICC TNM staging system, and the 8th edition provided significantly better accuracy in predicting DFS and DSS in patients with DTC.

Clinical outcomes of parathyroidectomy versus cinacalcet in the clinical management of secondary hyperparathyroidism

Parathyroidectomy (PTX) is the standard treatment for secondary hyperparathyroidism (SHPT); however, the administration of cinacalcet has gained prominence as a noninvasive treatment. We aimed to determine whether PTX or cinacalcet is more effective in preventing morbidity and mortality through reviewing follow-up data concerning surgical management of SHPT. We retrospectively analyzed and divided 209 patients with SHPT into two treatment groups: PTX (n = 78) and cinacalcet (n = 131) groups. We compared clinical features, the over-the-target range rate during pre- and post-intervention periods, new cardiovascular events, and all-cause mortality between both groups. Almost all biochemical parameters were well controlled in the post-intervention period, and were within the recommended target range for the PTX group but not for the cinacalcet group. A significant difference was observed in the over-the-target range rate during the post-intervention period between the groups. PTX and cinacalcet interventions significantly lowered the over-the-target range rates for serum intact parathyroid hormone (iPTH) (>300 pg/mL), corrected calcium (>10.5 mg/mL), serum phosphorus (>5.5 mg/dL), and calcium-phosphorus product (>55) in both groups (p = 0.001). PTX reduced the risk of new cardiovascular events by 86% compared to cinacalcet (p = 0.001); however, all-cause mortality did not differ significantly (14.1% vs. 7.6%, p = 0.132). For patients with SHPT, PTX helps prevent cardiovascular events through normalizing biochemical variables, according to recommended guidelines. PTX should be considered before cinacalcet treatment to prevent new cardiovascular events. Early PTX for appropriate patients can help prevent immediate postoperative complications and mortality.

Surgical outcomes of laparoscopic adrenalectomy for primary hyperaldosteronism: 20 years of experience in a single institution

Purpose

Recently, posterior retroperitoneoscopic adrenalectomy (PRA) has been reported to have some advantages over laparoscopic transperitoneal adrenalectomy (LTA). The objectives of this study were to report our experience over 12 years with laparoscopic adrenalectomy for primary hyperaldosteronism (PHA) and to examine surgical outcomes of PRA compared with LTA in patients with PHA.

Methods

The medical records of 527 patients who underwent minimally invasive adrenalectomy, including LTA or PRA, from January 2006 until May 2017 were reviewed at Severance Hospital (Seoul, Korea). Clinicopathologic characteristics and surgical outcomes of 146 patients with PHA who underwent LTA (19 patients) or PRA (127 patients) were analyzed retrospectively by complete chart review.

Results

The overall rates of biochemical and clinical cure were 91.1% and 93.1%, respectively. The mean operation time of the PRA group was significantly shorter than that of the LTA group (72.3 ± 24.1 minutes vs. 115.7 ± 69.7 minutes, P = 0.015). The length of hospital stay in the PRA group was significantly shorter than in the LTA group (3.5 ± 1.3 days vs. 4.2 ± 1.6 days, P = 0.029), and the first meal after surgery came earlier in the PRA group (0.3 ± 0.5 days vs. 0.6 ± 0.5 days, P = 0.049). The number of pain-killers used was also significantly smaller in the PRA group (2.3 ± 2.1 vs. 4.3 ± 2.3, P < 0.001).

Conclusion

PRA offers an alternative or likely superior method for treatment of small adrenal diseases such as PHA, with improved surgical outcomes.

Current trends in the features of male thyroid cancer: Retrospective evaluation of their prognostic value

This study aimed to compare the clinicopathologic characteristics and oncologic outcomes of papillary thyroid cancer (PTC) patients according to sex. Then, we validated prognostic variables to determine whether sex is a significant prognostic factor for PTC.Between January 2007 and December 2010, 1232 men and 7276 women PTC patients underwent surgery. The patient characteristics and 5-year oncologic outcomes were compared. The stepwise Cox proportional hazards model determined the significance of survival variables.Men PTC patients had more lymph node (LN) metastases than women, both in the total (P < .0001) and hemithyroidectomy (P < .0001) patients. Men and women showed similar 5-year recurrence-free survivals, both in total (P = .815) and hemithyroidectomy (P = .148) patients. The tumor size and the number of positive central nodes were associated with tumor recurrence, but not sex.Sex was not an independent prognostic factor for tumor recurrence. Multicenter clinical studies with long-term follow-ups are needed to validate these results.

MON-548 The Relationship of Comorbidities to Mortality and Cause of Death in Patients with Differentiated Thyroid Carcinoma

Background: Understanding how comorbidities contribute to death in cancer patients is becoming an important topic. The present study assessed the role of comorbidities in overall mortality and causes of death in patients with differentiated thyroid carcinoma (DTC). Methods: This retrospective cohort study included 2070 patients who underwent thyroidectomy for DTC at a single institution between 2002 and 2005. Probabilities of overall, DTC-specific, and other-cause death were examined according to estimated comorbidity levels with consideration for competing events. Results: The estimated 15-year cumulative incidences of overall, DTC-specific, and other-cause death were 7.3%, 1.6%, and 5.7%, respectively. With the low comorbidity level as a reference, moderate and severe comorbidity levels were associated with higher probabilities of other-cause death (subhazard ratio = 3.82 and 18.94, respectively; p <0.001) and consequently shorter overall survival (hazard ratio = 2.94 and 12.24, respectively; p <0.001), with adjustment for age, sex, and tumor-node-metastasis stage. In contrast, the probability of DTC-specific death was reduced in patients with severe comorbidity level (subhazard ratio = 1.24e-6, p <0.001). DTC-specific death was only observed in patients with low comorbidity level or with stage III/IV DTC and moderate comorbidity level. Conclusion: Death from DTC itself accounted for only a fraction of the overall deaths among patients who underwent surgery for DTC. Comorbidities increased overall mortality by increasing the probability of other-cause death. Patients with severe comorbidities had a low probability of dying from DTC because they died earlier from comorbidities.

The Prognosis of Papillary Thyroid Cancer with Initial Distant Metastasis is Strongly Associated with Extensive Extrathyroidal Extension: A Retrospective Cohort Study

BACKGROUND

Extensive extrathyroidal extension (ETE) has a significant role in the prognosis of papillary thyroid cancer (PTC) without distant metastasis, but its role in PTC with initial distant metastasis has never been studied. This study aimed to evaluate the prognostic significance of extensive ETE regarding disease progression, survival, and remission in PTC patients with initial distant metastasis.

METHODS

This retrospective cohort study included PTC patients with initial distant metastasis who underwent total thyroidectomy with a median follow-up period of 6.7 years. The prognostic significance of extensive ETE was assessed in terms of time to tumor progression (TTP), cancer-specific survival (CSS), and cumulative incidence of remission with all-cause death as the competing event.

RESULTS

The study enrolled 64 patients. Of these patients, 21 (32.8%) had extensive ETE, which was associated with a shorter TTP (adjusted hazard ratio [HR], 4.10; p = 0.015) and a lower CSS rate (p = 0.002, log-rank), particularly for patients 55 years of age or older with stage 4b disease (10-year CSS rate: 33.3% in those with and 92.3% in those without extensive ETE; p = 0.017). Additionally, remission was observed only in patients without extensive ETE (10-year cumulative incidence of remission: 0.0% in those with and 29.3% in those without extensive ETE; p = 0.013).

CONCLUSIONS

Extensive ETE of the primary lesion results in poorer prognoses for PTC patients with initial distant metastasis. The high CSS rate for patients with stage 4b PTC but no extensive ETE indicates that the prognosis of this patient population should be distinguished from that of other stage 4 cases.

Changes of computed tomography-based body composition after adrenalectomy in patients with endogenous hypercortisolism

CONTEXT

Data on longitudinal changes of computed tomography (CT)-determined visceral fat area (VFA), skeletal muscle area (SMA) and skeletal muscle radiodensity (SMD) after adrenalectomy are limited in patients with hypercortisolism.

OBJECTIVE

To examine the association of severity of cortisol excess and improvement of CT-based muscle and fat parameters after adrenalectomy.

DESIGN

Retrospective observational cohort study.

PATIENTS

One hundred thirty-four patients with overt Cushing's syndrome (CS; n = 39), mild autonomous cortisol excess (MACE; n = 57), or nonfunctioning adrenal tumour (NFAT; n = 38) at a tertiary endocrinology institution between 2006 and 2017 were included.

MEASUREMENTS

Changes in CT-determined VFA, visceral-to-subcutaneous fat ratio (VSR), SMA, skeletal muscle index (SMI), and SMD measured at the third lumbar vertebra (L3).

RESULTS

At baseline, CS patients had higher VFA, lower SMA, SMI and SMD values, compared to NFAT or MACE patients. Compared to NFAT, significant decreases in VFA and increases in SMA, SMI and SMD was observed in CS 1 year after adrenalectomy. In MACE, adjusted mean changes of SMD but not VFA, SMA or SMI differ significantly compared to NFAT (+8.9% vs -3.4%, P = 0.032). In a multivariate linear regression model, the increase by 1 μg/dL of post-dexamethasone serum cortisol at baseline was independently associated with greater reduction of VFA (-3.95%), VSR (-3.07%), and increase in SMD (+0.92%, P < 0.05 for all) after adrenalectomy.

CONCLUSIONS

The severity of cortisol excess was associated with greater improvement of L3 VFA, VSR and SMD 1 year after adrenalectomy. These CT-based markers may allow more objective assessment of treatment benefit at earlier stage.

Pattern of urine iodine excretion with low iodine diet during preparation for radioactive iodine ablation in patients with thyroid cancer

BACKGROUND

The optimal period of low iodine diet during preparation for radioactive iodine (RAI) ablation in an area with iodine-rich diet was investigated.

METHODS

Ninety-four patients with thyroid cancer who underwent low iodine diet and RAI were prospectively allocated into 2 groups-thyroxine withdrawal or using recombinant human thyroid stimulating hormone (rhTSH) for TSH stimulation. Their urinary iodine excretion (UIE) patterns were analyzed.

RESULTS

There was no clinicopathological difference between the 2 groups except for tumor size and lymph node status. The UIE (median iodine to creatinine ratio, I/Cr) in the withdrawal group on the 7th and 14th day were 18.3 and 17.9 μg/gCr, respectively, with adequate preparation rate of 93.3% on both days (cutoff value 100 μg/gCr). In the rhTSH group, the median I/Cr on the 7th and 14th day were 48.0 and 45.7 μg/gCr (adequate preparation rates 91.8% and 93.8%), respectively.

CONCLUSION

One week of low iodine diet is sufficient preparation for RAI regardless of method of TSH stimulation.

Oncologic outcomes in patients with 1-cm to 4-cm differentiated thyroid carcinoma according to extent of thyroidectomy

BACKGROUND

Recent guidelines advocate unilateral thyroidectomy for low-risk 1-cm to 4-cm differentiated thyroid cancer (DTC). This study was designed to examine the association between the extent of thyroidectomy and oncologic outcomes in patients with 1-cm to 4-cm DTC.

MATERIALS AND METHODS

From April 1978 to December 2011, 16 057 patients with DTC underwent thyroidectomy at Yonsei University Hospital. Among them, 5266 (32.8%) patients were classified as having 1-cm to 4-cm DTC and were enrolled in this study. Clinicopathologic features and prognostic results (disease-free survival [DFS] and disease-specific survival [DSS] rates) were analyzed by retrospective medical record review. The mean follow-up duration was 57.3 ± 58.1 months.

RESULTS

Of tumor subtypes in the study group, papillary thyroid carcinoma was the most common (97.5%) and follicular thyroid carcinoma occurred at a rate of 2.5%. In this study, the mean tumor size was 1.84 ± 0.74 cm. Patients had extrathyroidal extension (69.3%), multiplicity (35.1%), bilaterality (26.4%), central lymph node metastasis (53.0%), and lateral neck node metastases (19.9%). Of the 5266 patients, 4292 (81.5%) underwent total thyroidectomy and 974 (18.5%) had lobectomies. Recurrence rates in the total thyroidectomy and lobectomy groups were 5.7% and 9.4%, respectively. The lobectomy group had lower DFS (P = .007) and higher DSS (P = .034) than the total thyroidectomy group. A multivariate analysis for DFS revealed that tumor size, N classification, and extent of thyroidectomy were independent risk factors. On multivariate analysis, independent risk factors for DSS were age, sex, tumor size, and M classifications.

CONCLUSION

Although extent of thyroidectomy does not affect DSS, total thyroidectomy is beneficial for reducing recurrence in patients with 1-cm to 4-cm DTC. However, if such tumors have such low-risk features as being unifocal, intrathyroidal, and lymph node metastasis-negative, extent of thyroidectomy does not affect oncologic outcome and lobectomy may be sufficient.

Usefulness of dynamic risk stratification in pediatric patients with differentiated thyroid carcinoma

Purpose

Recently, the American Thyroid Association (ATA) dynamic risk stratification (DRS) has been verified to be more valuable than the static anatomical staging system for predicting prognosis in patients with differentiated thyroid carcinoma (DTC). The purpose of this retrospective study was to compare the clinical usefulness of DRS, which is based on the response to initial treatment, with that of ATA initial risk stratification in pediatric patients.

Methods

A total of 144 pediatric patients underwent thyroid operation from August 1982 to December 2013 at Yonsei University Hospital (Seoul, Korea). Among them, 128 patients with complete clinical data were enrolled in this study. Clinicopathologic features and surgical outcomes were retrospectively analyzed by medical chart review. The mean follow-up duration was 11.5 years.

Results

The mean tumor size was 2.1 cm; 80.4% of patients were diagnosed with conventional papillary thyroid carcinoma, and 7.0% of patients were diagnosed with follicular thyroid carcinoma. Low-risk patients had the highest probability of an excellent response to initial treatment (66.6%). High-risk patients had the highest probability of a structural incomplete response (100%) and the lowest probability of an excellent response (11.1%). The ATA risk stratification and the DRS system were independent risk factors for disease-free survival (DFS) (P = 0.041 and P < 0.001, respectively).

Conclusion

The DRS system, which is based on the response to initial treatment, can offer more useful prognostic information compared with ATA risk stratification in pediatric patients with DTC.

Yonsei Experience of 5000 Gasless Transaxillary Robotic Thyroidectomies

BACKGROUND

Since the use of robot systems in thyroid surgery was introduced in 2007, we have advanced a novel method of robotic thyroidectomy (RT) using a gasless transaxillary approach (TAA). We report our experience with this technique and detail the surgical outcome of 5000 robotic thyroidectomies.

METHODS

From October 2007 to May 2016, we successfully performed 5000 robotic thyroidectomies using a gasless TAA at the Department of Surgery, Yonsei University Health System. The medical records of the patients are reviewed retrospectively, and the details of clinicopathologic characteristics, operation times, perioperative complications, and oncologic outcomes are analyzed.

RESULTS

The 5000 patients with thyroid tumor (4804 with cancer and 196 with benign tumor) underwent RT using a gasless TAA. Mean operation time was 134.5 ± 122.0 min. The most common histologic subtype of thyroid cancer was papillary (98%), and the mean tumor size was 8.0 ± 6.0 mm. Stage I was found in 85.4% patients regarding tumor nodes metastasis staging. The 196 benign tumors consisted of 104 adenomatous hyperplasias (53.0%), 43 follicular adenomas (21.9%), 30 Graves' diseases (15.3%), and 19 others (9.7%). Postoperative complication occurred in 24.1% without any serious one, and overall morbidity tended to decrease over time. No disease-specific mortality was observed during the follow-up period. Locoregional recurrence was developed in 26 patients (0.5%).

CONCLUSION

The authors have tried to improve RT technique using gasless TAA and achieved acceptable surgical outcomes. The rapid evolution of surgical robot technology and our constant effort to advance RT technique using gasless TAA would make it possible to reduce the perioperative morbidity and gain the best possible operative and oncologic outcomes.

Long-term oncologic outcomes of papillary thyroid microcarcinoma according to the presence of clinically apparent lymph node metastasis: a large retrospective analysis of 5,348 patients

Purpose

Active surveillance (AS) of low-risk papillary thyroid microcarcinoma (PTMC) may reduce the risk of overtreatment of clinically insignificant cancer. However, the absence of predictor for the progression of PTMC resulted in treatment delay and potentially compromising cure of aggressive disease. Therefore, to anticipate potential damage of delayed surgery, we investigated the oncologic outcomes of patients with low-risk PTMC initially eligible for AS except clinically apparent lymph node metastasis (LNM), imitating delayed surgery with neck dissection.

Materials and methods

A total of 5,348 patients, enrolled between 1987 and 2016, with low-risk PTMC initially eligible for AS were included regardless of LNM. We classified our study patients into two groups: Group I, lobectomy with prophylactic central cervical node dissection; Group II, total thyroidectomy with modified radical neck dissection for LNM. In addition, we investigated the oncological outcomes of patients with second-wave surgery due to lateral lymph node recurrence (Group III, subgroup of Group I).

Results

Group I showed more favorable clinicopathological characteristics compared with Group II. In Group I, only 29 (0.58%) of 4,927 patients underwent second-wave surgery with neck dissection for lateral lymph node recurrences, whereas in Group II, all 22 (5.23%) of 421 patients underwent second-wave selective node dissection because of nodal recurrence. Disease-free survival rates were significantly different between Groups I and II (P<0.05). Of note, the recurrence rate of Group II was still significantly higher than that of Group III (5.2% vs 0%, respectively; P=0.021). In addition, Kaplan–Mayer survival analysis indicated poor disease-free survival rates in Group II compared with Group III (P<0.05).

Conclusion

The long-term treatment outcome of PTMC without LNM was favorable even if the recurrence occurs during follow-up period compared with that of PTMC with LNM. It should be noted that AS might be able to cause poor prognosis due to clinically apparent LNM.

C-Arm Computed Tomography-Assisted Adrenal Venous Sampling Improved Right Adrenal Vein Cannulation and Sampling Quality in Primary Aldosteronism

BACKGROUND

Adrenal venous sampling (AVS) is a gold standard for subtype classification of primary aldosteronism (PA). However, this procedure has a high failure rate because of the anatomical difficulties in accessing the right adrenal vein. We investigated whether C-arm computed tomography-assisted AVS (C-AVS) could improve the success rate of adrenal sampling.

METHODS

A total of 156 patients, diagnosed with PA who underwent AVS from May 2004 through April 2017, were included. Based on the medical records, we retrospectively compared the overall, left, and right catheterization success rates of adrenal veins during the periods without C-AVS (2004 to 2010, n=32) and with C-AVS (2011 to 2016, n=124). The primary outcome was adequate bilateral sampling defined as a selectivity index (SI) >5.

RESULTS

With C-AVS, the rates of adequate bilateral AVS increased from 40.6% to 88.7% (P<0.001), with substantial decreases in failure rates (43.7% to 0.8%, P<0.001). There were significant increases in adequate sampling rates from right (43.7% to 91.9%, P<0.001) and left adrenal veins (53.1% to 95.9%, P<0.001) as well as decreases in catheterization failure from right adrenal vein (9.3% to 0.0%, P<0.001). Net improvement of SI on right side remained significant after adjustment for left side (adjusted SI, 1.1 to 9.0; P=0.038). C-AVS was an independent predictor of adequate bilateral sampling in the multivariate model (odds ratio, 9.01; P<0.001).

CONCLUSION

C-AVS improved the overall success rate of AVS, possibly as a result of better catheterization of right adrenal vein.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Effects of Rubidium Chloride on the Course of Manic-Depressive Illness

Clinical studies of the effects of rubidium ions on the course of manic-depressive illness are reported. It seems that rubidium tends to increase the length of manic phases and possibly reduces the extremes of mood. Rubidium did not seem to produce any severe side effects in the dose administered, but it has a long biological half-life and caution is still required. Some details of the CSF, RBC, saliva and plasma and urine kinetics are also reported.

Posterior Retroperitoneoscopic Resection of Extra-adrenal Paraganglioma Located in the Aorto-caval Space

BACKGROUND

The posterior retroperitoneoscopic adrenalec tomy has several advantages compared with the transperitoneal approach such as a shorter and more direct route to the target organ, no breach of the intraperitoneal space, and no required retraction of the adjacent organs. It also is a safe procedure with a short learning curve.1^-5 This report presents a challenging case of an extra-adrenal paraganglioma located in the aorto-caval space and managed using the retroperitoneal approach.

METHODS

A 39-year-old man was placed in the prone jackknife position, and three incisions were made in the right posterior abdominal wall for placement of the laparoscopic ports. The retroperitoneal space was entered with diathermy and blunt finger dissection, and retropneumoperitoneum was achieved with carbon dioxide insufflation pressure up to 18 mmHg. After identification of the right kidney and vessels, the tumor was meticulously dissected and excised with an energy device. The specimen was removed using a laparoscopic specimen retrieval bag, and the port sites were closed in layers.

RESULTS

The operative time was 130 min, and the total blood loss was 30 ml. The tumor was diagnosed as a moderately differentiated extra-adrenal paraganglioma. The Von Hippel-Lindau gene mutation was detected using next-generation sequencing.

CONCLUSIONS

The posterior retroperitoneoscopic approach is a safe, feasible, and effective method for excising an extra-adrenal paraganglioma even in the aorto-caval space. The authors suggest that this procedure is a useful surgical option for treatment of an aorto-caval paraganglioma for selected patients and by experienced surgeons.

Dynamic risk stratification in medullary thyroid carcinoma: Single institution experiences

Recently, dynamic risk stratification has been found to be more valuable than static anatomic staging system in nonmedullary thyroid cancer and this strategy has also been accepted in medullary thyroid cancer (MTC). The present study was designed to compare the clinical usefulness of response to initial therapy stratification with a traditional anatomic staging system.From August 1982 to December 2012, a total of 144 MTC patients underwent thyroidectomy in Yonsei University Hospital. Among them, 117 (82.2%) patients with complete clinical data and sustained follow-up were enrolled in this study. Clinicopathological features and surgical outcomes were analyzed by retrospective medical chart review. Mean follow-up duration was 85.78 ± 62.51 months.In this study, mean tumor size was 1.94 ± 1.40 cm and 22 (18.9%) patients had hereditary MTC; 95 (81.1%) patients had sporadic MTC. Stage I patients had highest probability of excellent response to initial therapy (92.1%). Stage IV patients had highest probability of biochemical and structural incomplete response to initial therapy (57.5% and 30.3%) and lowest probability of excellent response to initial therapy (12.1%). Both response to initial therapy stratification and TNM staging system offered useful prognostic information in this study. The TNM staging system provided risk stratification pertaining to disease-free survival (DFS), disease-specific survival (DSS), and the probability of having no evidence of disease at final outcome, but did not provide risk stratification pertaining to the probability of having biochemical persistent/recurrence disease at final outcome. However, response to initial therapy stratification provided risk stratification pertaining to not only DFS, DSS, and the probability of having no evidence of disease at final outcome but also the probability of having biochemical persistent/recurrence disease at final outcome.In this study, we demonstrated that dynamic risk stratification with adjusted response to initial therapy system can offer more useful prognostic information than anatomic staging system in MTC.

Laparoscopic total pancreatectomy for multiple metastasis of renal cell carcinoma of the pancreas: a case report and literature review

Advances in surgical techniques and laparoscopic instruments have resulted in the development of laparoscopic pancreatic surgery. Total pancreaticoduodenectomy is performed for treating benign and borderline pancreatic disease involving the whole pancreas. Here, we report a case of metastatic renal cell carcinoma in the pancreas, treated by laparoscopic pylorus-preserving total pancreaticoduodenectomy. A 59-year-old woman was diagnosed with metastatic renal cell carcinoma. Multiple metastatic lesions were found on routine follow-up. She had a history of radical video-assisted right-nephrectomy for renal cell carcinoma (conventional type, pT1) in November 2003, without any recurrence. However, in 2014, a routine health checkup revealed multiple enhancing lesions throughout the pancreas. Positron emission tomography showed a suspicious 4-cm lesion in her left thyroid. Laparoscopic pylorus-preserving total pancreaticoduodenectomy with splenectomy was performed, along with simultaneous left total thyroidectomy with central compartment node dissection for metastatic renal cell carcinomas. The total operation time was 441 min, with an estimated blood loss of 150 ml; no transfusion was administered. Her hospital stay was 12 days. The histopath report confirmed metastatic renal cell carcinoma in the pancreas and left thyroid. Based on literature reviews, we further tried to estimate the oncologic outcome of total pancreatectomy in multiple pancreatic metastasis of renal cell carcinoma. Laparoscopic pylorus-preserving total pancreaticoduodenectomy is feasible and safe, even in cases of metastatic renal cell carcinoma.

Single-Incision, Gasless, Endoscopic Trans-Axillary Total Thyroidectomy: A Feasible and Oncologic Safe Surgery in Patients with Papillary Thyroid Carcinoma

BACKGROUND

The aim of this study is to compare the feasibility and oncologic safety of Single-incision, gasless, Endoscopic trans-axillary bilateral Total thyroidectomy (SET) with open cervical total thyroidectomy in patients with papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

From March 2008 to December 2012, PTC patients underwent bilateral total thyroidectomy. Conventional, open surgery was performed on 538 patients (Group O) and endoscopic surgery was performed on 200 patients (Group E). We analyzed the patient's clinicopathologic, postoperative complications, and surgical completeness.

RESULTS

The mean ages of the patients were 48.9 ± 0.5 (range = 24-77) in Group O and 39.5 ± 0.8 (range = 17-73) in Group E with statistical significance (P < .001). Percentage of female patients were 74.3% in Group O and 96.0% in Group E with statistical significance (P < .001). The postoperative hospital stay in Group O was significantly longer than Group E (4.60 ± 0.05 versus 3.30 ± 0.05; P < .001). The operation time in Group E was significantly longer than Group O (93.9 ± 1.3 versus 142.6 ± 3.3; P < .001). More transient hypocalcemia was found in Group O compared to Group E with statistical significance (28.1% versus 22.4%; P < .001). There were no significant differences with respect to permanent hypocalcemia, permanent recurrent laryngeal nerve palsy, seroma, and hematoma. The mean 1 year-stimulated sTg was 0.23 ± 0.03 and 0.18 ± 0.02 in Group O and E, respectively. Tumor recurrence during short-term follow-up at neck ultrasonography (1 year) was detected in 4 patients in Group O.

CONCLUSION

SET is safe and effective, not only for low-risk patients with early-detected cancer, but also for selected cases of advanced cancer.

Is familial papillary thyroid microcarcinoma more aggressive than sporadic form?

Purpose

With the increasing incidence of papillary thyroid microcarcinoma (PTMC), familial papillary thyroid microcarcinoma (FPTMC) is now recognized more frequently. However, the biological behavior of FPTMC is poorly understood. The aim of this study was to investigate the prevalence of FPTMC and its biological aggressiveness.

Methods

Between March 2006 and July 2010, 2,414 patients underwent primary surgical therapy for PTMC and 149 (6.2%) were further classified as FPTMC. To determine the biological aggressiveness of FPTMC, we compared the clinicopathological features and prognosis between FPTMC and sporadic PTMC (SPTMC).

Results

The male-to-female ratio was higher in FPTMC than in sporadic papillary thyroid microcarcinoma (SPTMC: 1:4.5 vs. 1:7.2, P = 0.041). The central lymph node (LN) metastasis rate was significantly higher in FPTMC than in SPTMC (36.2% vs. 24.2%, P = 0.002). The local recurrence rate was also higher in FPTMC than in SPTMC (4.5% vs. 0.6%, P < 0.001). We identified familial occurrence in 6.2% of cases of PTMC. FPTMC is associated with a high rate of central LN metastasis and local recurrence.

Conclusion

These findings suggest that close follow-up can be beneficial in FPTMC patients to detect local recurrence.

Practical Performance of the 2015 American Thyroid Association Guidelines for Predicting Tumor Recurrence in Patients with Papillary Thyroid Cancer in South Korea

BACKGROUND

The 2015 American Thyroid Association (ATA) management guidelines for adult patients with differentiated thyroid cancer propose the use of the modified initial risk stratification and response to therapy re-stratification systems. This study was conducted to validate the practicality of the revised guidelines for predicting tumor recurrence in patients with differentiated thyroid cancer.

METHODS

Patients with papillary thyroid cancer (n = 2425) who underwent total thyroidectomy with central neck node dissection with or without modified radical neck node dissection at a single institution between October 1985 and July 2009 were retrospectively enrolled. The accuracy of three different risk-stratification strategies for predicting disease-free survival, set out in the 2009 and 2015 ATA management guidelines, was assessed: the initial risk stratification (ATA 2009-RSS), the modified initial risk stratification (ATA 2015-RSS), and the response to therapy re-stratification (ATA 2015-RTR).

RESULTS

After applying the ATA 2015-RSS, 258/1913 (13.5%) of patients originally designated as intermediate risk by the ATA 2009-RSS were designated as low risk. This was mainly due to the small number of metastatic lymph nodes. Recurrence was detected in 136 (5.6%) patients during follow-up. Of the 2425 cases examined, 375 were designated as low risk by the ATA 2009-RSS, with a recurrence rate of 1.1%. However, the ATA 2015-RSS designated 633 (26.1%) cases as low risk, with a recurrence rate of 0.9%. Implementing the ATA 2015-RTR predicted an excellent response in 1597 (65.9%) cases, with a recurrence rate of 1.1%. According to the proportion of variance explained (PVE), the Akaike information criterion, Harrell's c index, and integrated area under the curve, comparing the predictive accuracy of the ATA 2009-RSS, ATA 2015-RSS, and ATA 2015-RTR revealed that the ATA 2015-RTR was a superior predictor of recurrence.

CONCLUSIONS

A proportion of patients designated as intermediate risk by the ATA 2009-RSS were designated as low risk by the ATA 2015-RSS. The ATA 2015-RTR may be the most accurate predictor of risk of recurrence.

Medullary thyroid carcinoma: a 30-year experience at one institution in Korea

PURPOSE

The objective of this study was to review the clinical outcome and prognosis of patients with sporadic and hereditary medullary thyroid cancer (MTC) who were treated at a single tertiary hospital in Korea.

METHODS

We retrospectively reviewed the case files of 85 patients treated from August 1982 to February 2012.

RESULTS

In all, 65 patients (76.5%) had sporadic MTC and 20 patients (23.5%) had hereditary MTC. Patients in the sporadic group were older than in the hereditary group (P < 0.001). However, the hereditary group had more tumor multiplicity (P < 0.001) and bilaterality (P < 0.001). Neither survival rate was significantly different between the sporadic and hereditary groups (P = 0.775 and P = 0.866). By multivariate analysis, distant metastasis was a significant prognostic factor for overall and progression-free survival.

CONCLUSION

In general, patients with MTC have favorable outcomes. Distant metastasis appears to be the strongest predictor of overall and progression-free survival.

Is focused parathyroidectomy appropriate for patients with primary hyperparathyroidism?

Purpose

The aim of this study was to determine whether focused or complete parathyroidectomy was more appropriate and to compare follow-up data in primary hyperparathyroidism (PHPT).

Methods

We retrospectively analyzed 225 operations for PHPT at Yonsei University Health System between 2000 and 2012. After excluding 93 patients, the remaining 132 were divided into 2 groups: those who underwent focused parathyroidectomy (FP) and those who underwent conventional parathyroidectomy (CP). We compared clinicopathological features; preoperative calcium, parathyroid hormone (PTH), phosphorus, vitamin D, 24-hour urine calcium, and alkaline phosphatase levels; postoperative calcium and PTH levels; pathologic diagnosis; multiplicity; and results of a localization study between the 2 groups.

Results

There was no significant difference in the rates of development of postoperative persistent hyperparathyroidism (1/122 FP patients and 1/10 CP patients) between the 2 groups due to a technical reason (FP 0.8% vs. CP 10.0%, P = 0.146). Multiglandular disease (MGD) was uncommon in all cases (6 of 132, 4.5%). All MGD cases were diagnosed using a preoperative localization study. Sestamibi scan and ultrasonography sensitivity were 94.2% and 90.2%, respectively.

Conclusion

We suggest that FP is appropriate in PHPT, except in cases of MGD if detected before the operation using preoperative imaging. Knowledge of hereditary PHPT and improved preoperative localization studies, such as high-resolution ultrasonography, contributed to the decision to perform FP rather than CP in all cases of unilateral results of the localizing study.

Transaxillary robotic modified radical neck dissection: a 5-year assessment of operative and oncologic outcomes

BACKGROUND

Robotic modified radical neck dissection (MRND) using a gasless transaxillary approach has been reported to be a safe and meticulous technique in patients with papillary thyroid carcinoma (PTC) and lateral neck node metastasis (N1b). Few studies, however, have attempted to assess the long-term oncologic outcomes of robotic MRND in these patients. This study aimed to compare perioperative and 5-year oncologic outcomes of robotic MRND with conventional open procedures in patients with N1b PTC.

METHODS

Between September 2007 and February 2010, 193 patients with N1b PTC underwent total thyroidectomy and MRND by a single surgeon. Of these, 42 (21.8 %) underwent robotic procedures and 151 (78.2 %) underwent conventional open procedures. All patients received 3.7- to 5.5-GBq radioactive iodine (RAI) ablation, post-therapy whole-body scans (TxWBSs), and diagnostic WBS (DxWBSs) during follow-up. An exact 1:3 matching for age and stage was performed to minimize selection bias, and perioperative and 5-year oncologic outcomes were compared in the matched groups.

RESULTS

The mean follow-up period was 66.0 months (range 60-90 months). Number of retrieved cervical lymph nodes (LNs) (p = .102) and postoperative ablation success rates (p = .864) were similar between the two groups. TSH-suppressed serum Tg concentrations after 5 years (0.7 ± 1.5 vs. 2.4 ± 14.1 ng/ml; p = .471) and recurrence rates in the robotic and open groups (1/41 [2.4 %] vs. 3/102 [2.9 %]; p = .864) were similar for the 5-year follow-up period. Four patients experienced recurrence: Three exhibited regional lymph node metastasis, and one showed bilateral lung metastases.

CONCLUSION

The perioperative and 5-year oncologic outcomes were similar after robotic and conventional open MRND. Large, prospective randomized controlled trials with long-term follow-up data are needed to validate these results.

Optimal Cut-Off Values of Lymph Node Ratio Predicting Recurrence in Papillary Thyroid Cancer

Regional lymph node (LN) metastasis has a significant impact for prediction of recurrence in patients with papillary thyroid cancers (PTC); however, the prognostic value of the lymph node ratio (LNR), which is defined as the ratio of the number of metastatic LNs to the total number of investigated LNs, is controversial. In this study, we determined the optimal cut-off values of LNRs for the prediction of recurrence in PTC patients.This large cohort study retrospectively evaluated 2294 patients who had undergone total thyroidectomy for PTC at a single institution from October 1985 to June 2009. The prediction probability of central LNR (cLNR, level VI) and total LNR (tLNR, levels II-VI) were estimated by binominal logistic regression analysis. Hazard ratios of the cut-off LNR values for cancer recurrence were calculated for relevant covariates using multivariate Cox regression analyses. Kaplan-Meier analyses were also utilized to assess the effects of estimated LNR cut-off values on recurrence-free survival (RFS).Of the 2294 patients, 138 (6.0%) presented cancer recurrence during the follow-up period (median duration = 107.1 months). The prediction probability indicated that LNRs of 0.4 and 0.5 for central LN and total LN, respectively, are optimal cut-off values for precise prediction with minimization of outliers. Multivariate Cox regression analyses revealed that cLNR ≥0.4 was independently predictive of recurrence in patients with N0 and N1a PTCs (hazard ratio [HR]: 7.016, 95% confidence interval [CI]: 3.72-12.986, P < 0.001) and that tLNR ≥0.5 indicated a significantly increased risk of recurrence in patients with N1b PTCs (HR: 2.372, 95% CI: 1.458-3.860, P < 0.001). In addition, Kaplan-Meier analyses clearly demonstrated that these LNR cut-off values are precisely operational in RFS estimation.The cut-off LNR values of 0.4 and 0.5 for cLNR and tLNR, respectively, were identified. Risk stratification combined with these LNR cut-off values may prove useful to determine treatment and follow-up strategies for PTC patients.