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.

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.

TERT Promoter and BRAF V600E Mutations in Papillary Thyroid Cancer: A Single-Institution Experience in Korea.

Telomerase reverse transcriptase (TERT) promoter mutation has been investigated for its clinical and prognostic significance in aggressive papillary thyroid cancer (PTC). In this study, we aimed to assess the prevalence, clinicopathologic features, and treatment outcomes of TERT mutation-positive PTCs along with the common BRAF V600E mutation. We performed mutational analyses for BRAF and the TERT promoter in thyroid cancer patients who had undergone surgery at our institution since 2019. We reviewed and analyzed 7797 patients with PTC in this study. The prevalence of BRAF V600E and TERT promoter mutations was 84.0% and 1.1%, respectively. Multifocal gene mutations in bilateral PTCs were identified. TERT promoter mutations were associated with older age, larger tumor size, tumor multifocality, tumor variants, advanced stages, more adjuvant radioactive iodine treatment (RAI), higher stimulated serum thyroglobulin level before RAI, and more uptakes in the regions outside the surgical field on a post-RAI whole-body scan. The coexistence of BRAF V600E and TERT promoter mutations exacerbated all clinicopathologic characteristics. The frequency of TERT promoter mutations was the lowest in this study, compared to previous studies. TERT promoter mutations consistently correlated with aggressive PTCs, and the synergistic effect of both mutations was evident. Specific clinical settings in our institution and in Korea may have led to these distinctive results. Prospective multicenter studies with longer follow-up periods are required to establish valuable oncologic outcomes.

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.

Re-do Operation Using a Robotic System due to Locoregional Recurrence after Initial Thyroidectomy for Thyroid Cancer.

Locoregional recurrent thyroid cancer is commonly treated with re-do operation. This study aimed to investigate the feasibility of using robotic system for re-do operation in locoregional recurrent thyroid cancer. Sixty-five patients who underwent re-do robotic operation using trans-axillary approach for locoregional recurrent thyroid cancer from October 2007 to April 2021 at Yonsei University Hospital were analyzed. Completion total thyroidectomy (CTT) was performed in 26 cases, CTT and modified radical neck node dissection (mRND) in 16, and mRND in 23. Most of the re-do robotic operations were performed at site of previous incision. All patients were diagnosed with papillary thyroid carcinoma (PTC). CTT with central compartment neck dissection (CCND) took 117.6 ± 26.3 min, CTT with mRND 255.6 ± 38.6 min, and mRND, 211.7 ± 52.9 min. Transient hypocalcemia occurred in 17 (26.2%) patients and permanent hypocalcemia occurred in 3 (4.6%). There was one case of recurrent laryngeal nerve(RLN) injury. One patient was diagnosed with structural recurrence after re-do robotic operation. Median follow-up duration was 50.7 ± 37.1 months. Re-do robotic operation can be an alternative for patients who are diagnosed with locoregional recurrent thyroid cancer after thyroidectomy, with no increase in morbidity, similar oncologic outcomes, and superior cosmetic satisfaction.

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

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.

Parathyroid venous sampling for the preoperative localisation of parathyroid adenoma in patients with primary hyperparathyroidism.

Preoperative localisation studies are essential for parathyroidectomy in patients with primary hyperparathyroidism. If the location of abnormal parathyroid glands cannot be identified through non-invasive studies, parathyroid venous sampling (PVS) may be employed. In this study, we evaluated the utility of preoperative PVS in parathyroid surgery. Patients with primary hyperparathyroidism who underwent preoperative PVS at Severance Hospital between January 2015 and June 2020 were identified. Patients for whom the results of non-invasive imaging studies were inconsistent or negative underwent PVS. The results of PVS were compared with operative findings and pathologic results. For 14 patients, the results of preoperative ultrasonography and 99mTc-sestamibi single-photon emission computed tomography (SPECT) were negative; for 20 patients, either the result of only one test was positive, or the results of the two tests were inconsistent. With respect to the lateralisation of diseased adenoma, the results of PVS and pathological examination were inconsistent only for one patient in either group (total: 2/34 patients). This study showed that PVS could be used effectively for preoperative localisation in patients with primary hyperparathyroidism in whom the location of diseased parathyroid glands cannot be determined through non-invasive image studies.

Clinical Implications of Age in Differentiated Thyroid Cancer: Comparison of Clinical Outcomes between Children and Young Adults.

BACKGROUND: Pediatric patients with differentiated thyroid cancer (DTC) present with unique characteristics compared to adult patients. This study aimed to evaluate clinical presentation and surgical outcomes according to age and to identify the clinical significance of age in DTC. METHODS: In total, 98 pediatric patients, 1261 young adult patients, and 4017 adult patients with DTC who underwent thyroid surgery between January 1982 and December 2012 at Yonsei University Hospital (Seoul, Republic of Korea) were retrospectively reviewed. The mean follow-up duration was 120.4 ± 54.2 months. RESULTS: Mean tumor size was significantly larger in the pediatric group than in the adult groups (p < 0.001). The recurrence rate was significantly higher in the pediatric group (14.3% versus 6.6% versus 3.0%, p=0.004 and p < 0.001). In multivariate analysis, the risk of disease-free survival (DFS) was lower in the adult group (HR, 0.362; p < 0.001). Reanalysis of patients with tumor size of 2-4 cm revealed that the adult group was not a significant risk factor for DFS in multivariate analysis (HR, 0.305; 95% CI, 0.158 to 0.588; p < 0.001). CONCLUSIONS: Our findings suggest that pediatric patients present with more aggressive features and higher recurrence rates compared to adult patients and should be carefully treated from initial evaluation to surgery and postoperative care.

Safety and Feasibility of Robotic Transaxillary Thyroidectomy for Graves' Disease: A Retrospective Cohort Study.

BACKGROUND: Despite the increase in experience and understanding of robotic thyroidectomy, its application for Graves' disease (GD) remains controversial. This study aimed to assess the safety and feasibility of robotic transaxillary thyroidectomy (RTT) for GD in comparison with the conventional open thyroidectomy (open group: OG) approach. METHODS: A total of 192 patients who underwent surgical resection for GD were retrospectively reviewed. Among them, 51 patients underwent RTT and the remaining 141 patients were in the conventional OG. RESULTS: All robotic operations were performed successfully without open conversion. Patients who underwent RTT were significantly younger (P < 0.001) and predominantly of the female sex. Operative time was longer for RTT than for the OG (182.5 ± 58.1 vs. 112.0 ± 29.5; P < 0.001). The mean intraoperative blood loss was not statistically different between RTT and the OG (113.3 ± 161.6 vs. 95.3 ± 209.1, P = 0.223). The mean weight of the resected thyroid was reduced in those who underwent RTT compared with open thyroidectomy (P = 0.033). The overall complication rate for RTT and open thyroidectomy was not significantly different (33.3% vs. 22.7%, P = 0.135). In RTT, the most common complication was transient hypocalcemia (21%). Permanent hypocalcemia and recurrent laryngeal nerve injury occurred in only one patient in each group. The weight of the resected thyroid was not related to the incidence of complications in patients receiving RTT. CONCLUSIONS: Considering excellent cosmesis, findings of this study support the safety and feasibility of RTT. Nevertheless, it should be performed by expert surgeons with extensive robotic surgery experience.

Robotic Adrenalectomy Using the da Vinci SP Robotic System: Technical Feasibility Comparison with Single-Port Access Using the da Vinci Multi-arm Robotic System.

BACKGROUND: Laparoscopic adrenalectomy is the gold standard for adrenal tumor; however, robotic adrenal surgery has gained interest recently. For minimally invasive surgeries, we first reported on robotic adrenalectomy using a single-port access performed using the da Vinci multi-arm robotic system (RA-SA) in 2011. Since its introduction in 2018, we first performed robotic adrenalectomy using the da Vinci SP robotic system in 2020. OBJECTIVE: We aimed to introduce the novel single-port robotic system (RA-SP) for adrenalectomy and evaluate its technical feasibility by comparing it with the surgical outcomes of patients who underwent robotic adrenalectomy using the RA-SA. METHODS: Eight patients who underwent robotic adrenalectomy using the RA-SP from February 2020 to June 2021 were compared with 11 patients who underwent RA-SA from 2011 to 2015 by a single surgeon. RESULTS: The two groups were similar in age, sex, body mass index, type of operation, and final pathologic diagnosis. Despite no significant differences, RA-SP resulted in moderately less mean operation time, estimated blood loss, and length of hospitalization. CONCLUSIONS: The Da Vinci SP robotic system is a novel, safe, and feasible technique to improve the convenience of operation and cosmetic effect for adrenalectomy.

Robotic transaxillary lateral neck dissection for thyroid cancer: learning experience from 500 cases.

BACKGROUND: Differentiated thyroid carcinoma with lateral neck lymph node metastasis requires aggressive operative intervention, including lateral neck dissection. Although several robotic approaches have made precise surgery for thyroid cancer possible, few centers have expanded the technique for application to lateral neck dissections. This study aimed to demonstrate the technical feasibility, cosmetic effectiveness, and safety of robotic transaxillary lateral neck dissection (RTLND) using the da Vinci system. METHODS: From January 2008 to July 2019, 500 patients diagnosed with thyroid cancer with lateral neck node metastasis underwent RTLND. The clinicopathologic characteristics and surgical outcomes were retrospectively reviewed. RESULTS: All operations were performed successfully without open conversion. As the primary operation for thyroid cancer, 476 (95.2%) patients underwent unilateral or bilateral RTLND, including robotic total thyroidectomy. The remaining 24 patients (4.8%), all of whom had a recurrence, also underwent RTLND with additional procedures, if needed. The mean operation time for the 500 operations was 293.71 ± 67.22 min. Only five cases had recurrence and required further treatment. CONCLUSIONS: RTLND is technically feasible and safe through the precise manipulation of robotic instruments. While this method is thorough and provides safe and effective surgical outcomes, it also offers the additional advantage of being minimally invasive.

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.

Outcomes of Subtotal Parathyroidectomy Versus Total Parathyroidectomy With Autotransplantation for Tertiary Hyperparathyroidism: Multi-institutional Study.

OBJECTIVES: Due to the paucity of data and controversy regarding the preferred surgical approach for managing tertiary HPT, we sought to investigate the outcomes of different surgical approaches in managing this challenging disease. METHODS: We performed a multi-center retrospective study to include patients with tertiary HPT who underwent STPX or total parathyroidectomy with autotransplantation (TPX-A). RESULTS: One hundred five patients had kidney transplant, and 43 were on dialysis. In the kidney transplant group, 61 patients underwent STPX, and 44 for TPX-A. Patients' demographics were not significantly different (48.61 ±â€Š9.31 vs 47.95 ±â€Š12.73 years, P = 0.759. The postoperative follow-up showed that the TPX-A cohort had a higher rate of hypoparathyroidism (N = 20, 45.45%) versus (N = 14, 22.95%) with the STPX cohort (P = 0.013). The cure among the TPX-A cohorts (84.09%) over the STPX cohort (73.77%) (P = 0.153). The long-term follow-up showed that the rate of developing temporary (N = 16, 41.03%) or permanent (N = 8, 20.51%) hypoparathyroidism was significantly higher among patients who underwent TPX-A over the patients who underwent STPX (N = 7, 17.95%), and (N = 4, 10.26%), respectively (P = 0.012). There was no statistical difference between the persistence (N = 3, 7.69%) or the recurrence (N = 2, 5.13%) of the HPT in the TPX-A cohort and the STPX cohort (N = 2, 5.13%). (N = 4, 10.26%), respectively, P = 0.644. CONCLUSIONS: To our knowledge, this is the largest multi-center study that compared different approaches for managing tertiary HPT. Showing that STPX is the better modality in patients diagnosed with tertiary HPT and had kidney transplants avoiding the risk of hypoparathyroidism.

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.

Efficacy of Immunohistochemistry for SDHB in the Screening of Hereditary Pheochromocytoma-Paraganglioma.

The most common genetic backgrounds of hereditary paraganglioma and pheochromocytoma (PPGL) are SDHx germline mutations. Given the fact that the immunohistochemistry (IHC) result for SDHB is always negative regardless of the type of SDHx mutation, we aimed to evaluate the efficacy of using SDHB IHC for screening SDHx mutations in PPGL cases. In total, 52 patients who underwent surgery for PPGL treatment between 2006 and 2020 and underwent genetic analysis at diagnosis were included. Tissue microarrays (TMAs) were constructed with PPGL tissues and IHC for SDHB was performed on TMA sections. All 10 patients with SDHB-negative IHC contained SDHB or SDHD mutations. The genetic test results of patients with SDHB-weakly positive IHC varied (one SDHB, two RET, one VHL, and three unknown gene mutations). There were no SDHx mutations in the SDHB-positive IHC group. Six patients with weakly positive SDHB IHC with primarily unknown genetic status were re-called and underwent next-generation sequencing. None of them had SDHx mutations. In conclusion, SDHB-negative IHC is a cost-effective and reliable method to predict SDHx mutations. However, in the case of weakly positive SDHB staining, an additional gene study should be considered.

Feasibility and safety of the posterior retroperitoneoscopic approach in the resection of aortocaval and infrarenal paraganglioma: a single-center experience.

BACKGROUND: The posterior retroperitoneoscopic approach (PRA) has been under attention as a method for resection of paraganglioma (PGL) for the past few years. However, only a few studies have explored the effectiveness and safety of the PRA for aortocaval and infrarenal PGL resection. METHODS: We designed this retrospective study to investigate the safety and effectiveness of the PRA for aortocaval and infrarenal PGL resection in a single center. We retrospectively reviewed the medical records of patients who underwent PRA for PGL resection at our medical center from January 2006 to March 2021. Eight patients were enrolled, of whom six had aortocaval PGL. We investigated the surgical outcomes of enrolled patients. RESULTS: The locations of the tumors in relation to the renal vein were: suprarenal in two (25.0%) patients, at the renal vein level in three (37.5%) patients, and infrarenal in three (37.5%) patients. The mean operative time of the enrolled patients was 101.5 ± 39.1 min. The mean postoperative stay was 3.5 ± 1.5 days, and the estimated blood loss was 31.3 ± 51.4 ml. There was one minor complication (chyle leakage), and two hypotensive events occurred during the surgery. Focusing on the results of the renal vein level and infrarenal PGL resection, the mean operative time, mean postoperative stay, and estimated blood loss of the patients were 109.2 ± 41.3 min, 3.5 ± 1.8 days, and 41.7 ± 56.4 ml, respectively. CONCLUSION: The PRA for aortocaval and infrarenal PGL resection is feasible and safe. Additional data analysis and long-term follow-up are needed in the future.