Minimally invasive surgery of the adrenal gland is widespread. Although reports demonstrate the safety and feasibility of robot-assisted adrenalectomy, the objective benefits are still unclear, compared to those of conventional laparoscopy. Recently, robot-assisted approach has also become possible for pheochromocytoma resection. Since cardiopulmonary changes during robot-assisted dissection of the pheochromocytoma patient has not been studied in detail, we aimed to assess these concerns, compared to the routine laparoscopic technique.

In this case-control study, 19 consecutive robot-assisted adrenal resections were compared with a control group consisting of 14 conventional laparoscopic adrenalectomy. Patient characteristics and intraoperative hemodynamic and respiratory parameters were assessed. Groups were compared using the χ2 test for categorical variables and Student's t-test for continuous variables. Significance was considered p < 0.05.

The robot-assisted procedure was performed successfully in all patients, except one. The duration of the robot-assisted procedure, compared to the conventional laparoscopy group, was significantly longer (p < 0.05). Intraoperative blood loss was significantly less in the robot-assisted group (p < 0.05). Dissection of pheochromocytoma showed a significant difference between the groups, according to the incidence of intraoperative blood pressure fluctuations (p < 0.05). The robot-assisted approach resulted in less incidents. Other hemodynamic and respiratory parameters did not differ between groups significantly. There were no perioperative deaths. Complication rates and postoperative hospital stays were not significantly different.

Robot-assisted adrenalectomy is a safe and technically feasible procedure for a pheochromocytoma patient. Robot-assisted resection of pheochromocytoma minimized the occurrence of intraoperative blood pressure fluctuations and blood loss.

To compare robot vs open thyroid surgery using inverse probability of treatment weighting (IPTW) with regard to oncologic safety in papillary thyroid carcinoma (PTC) patients.

We enrolled 722 patients with PTC who underwent a total thyroidectomy with central compartment node dissection (CCND) at the Asan Medical Center in Korea from January 2009 to December 2010. These patients were classified into open thyroid surgery (n = 610) or robot thyroid surgery (n= 112) groups. We verified the impact of robot thyroid surgery on clinical recurrence and ablation/control-stimulated thyroglobulin (sTg) levels predictive of non-recurrence using weighted logistic regression models with IPTW.

Age, sex, thyroid weight, extent of CCND, and TNM stage were significantly different between the two groups (p < 0.05); however, there was no significant difference in the recurrence rate between the open and robot groups (1.5 vs 2.7%; p = 0.608). The proportion of patients with ablation sTg < 10.0 ng/mL and control sTg < 1.0 ng/mL was comparable between the two groups (p > 0.05). Logistic regression with IPTW using the propensity scores estimated by adjusting all of the parameters demonstrated that robot thyroid surgery did not influence the clinical recurrence (OR: 0.784; 95% CI: 0.150–3.403; p = 0.750), ablation sTg (OR: 0.950; 95% CI: 0.361–2.399; p = 0.914), and control sTg levels (OR: 0.498; 95% CI: 0.190–1.189; p = 0.130).

Robot thyroid surgery is comparable to open thyroid surgery with regard to oncologic safety in PTC patients.

Thyroid nodules occur in more than 50% of populations over 50 years, and only 5% of thyroid nodules are malignant. This study was aimed to evaluate Doppler ultrasonography (US) combined with elastography in the diagnosis of the malignant thyroid nodules with suspicious fine needle aspiration cytological (FNAC) results.

From August 2012 to March 2013, 107 consecutive patients eligible for thyroid surgery enrolled in the study. All patients underwent FNAC study followed by conventional US, color Doppler US, and US elastography with a real-time instrument. Thyroid nodules ultrasonographic parameters were evaluated during conventional and color Doppler US study and elastography performed in order to calculate the strain index (SI) by dividing the strain value of the nodule by that of the peripheral normal parenchyma, prior to thyroidectomy.

Of 161 nodules in 107 patients, 76 (47.2%) were benign lesions and 85 (52.8%) were malignant. The overall Doppler US score depicted a sensitivity of 64% and specificity of 59%. Using a cut of 2.905, the sensitivity and specificity for elastography US were about 54 and 76% respectively, with positive predictive value of 71.8% and negative predictive value of 59.8%. Evaluating quantitative elastography combined with Doppler US, out of 68 nodules with positive peripheral halo ring, 44 had elasticity ≥ 2.905, which was statistically significant (p < 0.001).

Quantitative elastography combined with Doppler US is more accurate in thyroid nodules diagnosis comparing to other methods and can limit the use of FNAC and the subsequent thyroidectomy in patients with nondiagnostic or unsatisfactory cytological findings.

Prophylactic central lymph node dissection with total thyroidectomy (TT) for the treatment of papillary thyroid cancer (PTC) is controversial because of the possibility of increased morbidity with uncertain benefit. We evaluated the changing trends of lymph node ratio (LNR), recurrence, and radioablation therapy. Also, we evaluated the safety of omitting radioablation after TT with PTC, especially on low PNR (positive node ratio) N1a patients compared with high PNR N1a patients.

Consecutive 147 N1a and 216 N0 patients who underwent TT with central neck dissection were enrolled. We divided 147 N1a patients into two groups: 96 high-PNR vs 51 low-PNR group according to 50% of PNR, and compared three groups including N0 group.

There were 21/147 (14.3%) recurrences on N1a intermediate-risk patients and 5/216 (2.3%) on N0 low-risk patients. Of these 21 recurrences, 20 (95.2%) occurred in the high-PNR group and only 1 (4.8%) was in the low-PNR group. The recurrence in low-PNR group (Graph 1; green line) was significantly lower than in high-PNR group (red line; log-rank p value = 0.003), but significantly not different from the N0 group (blue line; log-rank p-value = 0.889). Although this study was a retrospective nonrandomized trial with less number of patients, the 10-year recurrence of omitting RAI in low-PNR intermediate-risk N1a patients with less than 50% of PNR was shown to be comparable with 216 N0 low-risk patients.

Prophylactic central neck dissection may lead to upstaging and low recurrence, but also to overuse of radioablation. Lymph node ratio could be a useful predictor of recurrence and useful guidance in radioablation therapy.

Some recent guidelines recommend unilateral thyroidectomy for low-risk differentiated thyroid cancer (DTC) sized > 1 and < 4 cm. The present study was designed to evaluate the proper extent of thyroidectomy for patients who have DTC sized > 1 and < 4 cm.

From April 1967 to December 2011, a total of 16,065 DTC patients underwent thyroidectomy at Yonsei University Hospital. Among them, 5,427 (33.7%) patients were classified as having DTC > 1 and < 4 cm and were enrolled in this study. Clinicopathologic features and prognostic results (disease-free and disease-specific survival rates) were analyzed by retrospective medical chart review. The mean follow-up duration was 57.3 ± 58.1 months.

In the subtypes of tumors, papillary thyroid carcinoma (PTC) was the most common cancer (96.9%) and follicular and poorly differentiated carcinoma comprised 2.7 and 0.1% respectively. The mean tumor size was 1.84 ± 0.74 cm. Patients had extrathyroidal extension (69.3%), multiplicity (35.0%), bilaterality (26.3%), central lymph node metastasis (35.8%), and lateral neck node metastases (20.2%). Of a total of 5,427 patients, 4,353 (80.2%) underwent total thyroidectomy and 1,043 (19.2%) patients underwent less- than-total thyroidectomy. The recurrence rates in total thyroidectomic and less-than-total thyroidectomic groups were 3.9 and 10.0% respectively. The less-than-total thyroidectomic group showed lower disease-free survival (DFS) rate (p= 0.039) and higher disease-specific survival (DSS) (p = 0.035) rate compared with the total thyroidectomic group. In multivariate analysis for DFS, tumor size, N stage, and the extent of thyroidectomy were independent risk factors. In multivariate analysis for DSS, age, gender, tumor size, and N and M stage were independent risk factors.

In patients with tumor size > 1 and ≤ 4 cm, total thyroidectomy was beneficial in reducing recurrence. However, our study confirmed that risk factors for DSS were not the extent of thyroidectomy but traditional prognostic factors, such as older age, male sex, large tumor size, lymph node metastasis, and distant metastasis.

Papillary thyroid cancer (PTC) is the most frequent subtype among thyroid cancers. Lymph node (LN) metastases are frequent in PTC and the incidence is 60% on average. Recent studies have shown that there has been an increase in the mortality or recurrence with LN metastases and that more than 5 metastatic LNs are clinically important. Therefore, we investigated clinicopathologic factors associated with clinically important LN metastases.

From January 2010 to October 2013, we retrospectively enrolled 2,628 PTC patients who underwent thyroidectomy at Ajou University Hospital. Among 1,425 patients with LN metastasis, 325 had ≥ 5 LN metastases.

In univariate analysis, young age (< 45 year), male gender, capsular invasion, multiplicity, tumor size, and lymphovascular invasion (p < 0.001) were statistically associated with both LN metastasis and ≥ 5 LN metastases. However, Braking Action Fair (BRAF) mutation was not important to predict LN metastasis (p > 0.05). In multivariate analysis, lymphovascular invasion was the most important factor (odds ratio: 4.7, 4.0) among other clinicopathologic factors (odds ratio:< 2.1).

Braking Action Fair (BRAF) mutation was not useful to predict the LN metastasis. However, lymphovascular invasion was the most important factor to predict more than five cervical LN metastasis which is very important clinically.

The number of elderly patients with primary hyperparathyroidism (PHPT) has been increasing as a result of declining birth rate and aging population in Japan. The safety and effectiveness of surgical treatment in old people with PHPT are still contentious.

We retrospectively investigated the characteristics and postoperative course in 55 patients over 70 years of age who underwent parathyroidectomy (PTX) for PHPT at our institution from February 1988 to May 2015.

Forty-four of the 55 patients had comorbidities such as hypertension, diabetes, and so on. In all the cases, PTX was successfully performed and the serum levels of parathyroid hormone and calcium lowered. Neuropsychiatric symptoms also improved in 14 patients after PTX. Except two cases, no severe complication occurred after PTX: one developed aspiration pneumonitis and one needed hemodialysis for acute exacerbation in chronic kidney disease.

Active and appropriate application of PTX might contribute to improvements in the activities of daily living and quality of life in elderly patients with PHPT.

Activin, a member of the transforming growth factor beta protein family, was originally isolated from gonadal fluids and stimulates the release of pituitary follicle-stimulating hormone (FSH). Activin has numerous functions in both normal and neoplastic cells. Although it was suggested that gonadal tissue is the primary site of activin production, several extragonadal sources have subsequently been identified, including human thyrocytes.

In our study, serum levels of activin A were measured by chemiluminescence, and the expression of receptors of activin A in thyroid tissue was detected by immunohistochemistry in female patients with thyroid papillary cancer [stage I (n = 60), stage II (n = 60), stage III (n = 60), stage IV (n = 60)] and in normal controls (n = 60).

The serum levels of activin A were no significantly different between patients with thyroid papillary cancer and normal controls as well as different stages. But the expressions of receptors of activin A were greater in patients with thyroid papillary cancer than in normal controls. And the positive rates of receptor expression were significantly more in stage III and IV than in stage I and II.

In conclusion, this study demonstrates that serum levels of activin A undergo no significant changes when thyroid papillary cancer occurs. The thyroid gland is not the predominant source of activin A. The expressions of receptors of activin A were significantly greater in patients with thyroid papillary cancer than in normal controls. And the positive rates of receptor expressions were associated with the severity of cancer. Because activin A may exert negative action on thyrocyte proliferation, it is conceivable that the increase in the receptor of activin A in thyroid papillary cancer might represent a counteracting mechanism.

Gastrointestinal and pancreatic neuroendocrine tumors (NET) are classified as low grade (G1), intermediate grade (G2), and high grade (G3) by mitotic rate and/or Ki-67 index. The basic treatment for neuroendocrine carcinoma (NEC, G3) with remote metastasis is platinum-based systemic chemotherapy. In contrast, for patients with NET G1 or G2 with remote metastasis, multidisciplinary treatment is necessary in order to prolong patients' survival and relieve symptoms. We report here a patient with pancreatic G1 gastrinoma and its multiple liver metastases.

The patient was a 42 years old male who had been suffering from diarrhea for 2 years, and his serum level of gastrin was as high as 4200 pg/mL before treatment. Needle biopsy of the liver proved the tumor was positive for chromogranin A, gastrin, and somatostatin receptor type 2A.

First, we chose an induction drug therapy with sunitinib and octreotide. The size of the liver tumors decreased dramatically and the serum gastrin level became lower than 500 pg/mL. About 1 year after diagnosis, we performed distal pancreatectomy and right hepatic lobectomy. After surgery, the serum gastrin level was normalized, and the activity of daily living (ADL) of the patient was much improved by the consecutive therapies. During the 2-year postoperative follow-up time, the course was favorable and no recurrent lesion was found.

Even when there are remote metastases, multidisciplinary treatment including surgical resection should be considered for G1/ G2 NET. Further, it should be necessary to study in a larger number of patients if perioperative drug therapy for G1/G2 NET with remote metastases is effective.

The efficacy of prophylactic central neck dissection (pCND) in patients with papillary thyroid carcinoma (PTC) is still unclear. The aim of this prospective randomized controlled study was to evaluate the clinical strengths and weaknesses of pCND.

Between May 2009 and September 2015, a total of 1,134 patients with clinical N0 PTC were randomly assigned to two groups. Group A was treated with thyroidectomy alone and group B was treated with thyroidectomy + pCND. When the surgeon detected extrathyroidal extension or suspicious lymph nodes during the operation, frozen biopsy was performed to confirm the metastasis and the patients were excluded. We analyzed the clinicopathologic characteristics, postoperative complications, and recurrence.

Of the 1,134 patients, 110 were excluded because they had evidence of either capsular invasion or lymph node metastasis proven by frozen biopsy during the operation (rate of dropout: 9.7%). A total of 1,024 patients were included, 504 patients in group A and 520 patients in group B. In group B, 67 patients had ipsilateral central lymph node metastasis in frozen biopsy that were converted to total thyroidectomy. Clinicopathologic characteristics of the two groups were not significantly different. The median follow-up period was 20 months (1–77 months). Recurrence was detected in three patients (0.3%) in the lateral lymph node. Disease-free survival was not statistically significantly different between the two groups (p = 0.561). However, the incidence of temporary hypoparathyroidism in group B was significantly higher than that in group A (group A: 13.1%, group B: 20.8%, p = 0.001), while the permanent hypoparathyroidism, vocal cord palsy, chyle leakage, bleeding, and wound infection were similar between groups A and B.

Prophylactic central neck dissection did not reduce locoregional recurrence in clinical N0 PTC, but it significantly increased the incidence of transient hypoparathyroidism. But the assessment of effectiveness of pCND in reducing recurrence and mortality requires a long-term follow-up.

In recent times, robot thyroid surgery has been performed worldwide in thyroid tumors, and reducing surgical complication is also an important factor in robot surgery besides thyroidectomy. This study presents the surgical technique of preserving the recurrent laryngeal nerve and parathyroid gland in transaxillary robot thyroid surgery.

The drawback of robot thyroid surgery is that it cannot tell how strong the surgeon is holding and retracting the tissues or feels the thermal change when energy device is activated. Dissection or manipulation should be performed by layers and structures. The surgeon should not advance to the next procedure immediately after activating the coagulating energy device when related to tissues for preservation since there could be a thermal injury. After the activation, pause or make contact to a gauze placed in the operative field to check the spread of remaining heat. The shielded side of the device should be placed to the remnant structure side. By doing so, the thermal spread could be minimized. When coagulating vessels, the surgeon should not impatiently manipulate the grasped tissues since they could tear before fully coagulated and encounter bleeding. When preserving the recurrent laryngeal nerve and parathyroid gland, these surgical tips are very important to minimize the injury.

Applying such surgical techniques, the result of preserving the recurrent laryngeal nerve and parathyroid gland is safe and secure in robot thyroid surgery as presented in our video clip.

Endocrine surgeons perform functionally safe thyroidectomy and reduce the surgical complications in any type of thyroid surgery. The above-mentioned techniques will help preserve the recurrent laryngeal nerve and parathyroid gland in robot thyroid surgery