Papers by Takahiro Okamoto
Research Square (Research Square), Aug 25, 2022
Original research article Risk factors of mediastinal lymph node metastasis and lung metastasis i... more Original research article Risk factors of mediastinal lymph node metastasis and lung metastasis in papillary thyroid carcinoma patients: Who benefits from preoperative computed tomography?
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association)
Case 1 : A 35-year-old female patient underwent laparoscopic bilateral adrenalectomy for bilatera... more Case 1 : A 35-year-old female patient underwent laparoscopic bilateral adrenalectomy for bilateral adrenal pheochromocytomas. As the right pheochromocytoma was too large (13.5 cm) to be removed only by a laparoscopic procedure, hand-assisted laparoscopic surgery (HALS) was used after adequate exposure of the tumor. Case 2 : An 82-year-old female underwent laparoscopic left adrenalectomy for a pheochromocytoma 10 cm in size. The posterior and superior surfaces of the tumor were dissected using a laparoscopic procedure, which was then converted to HALS. Both cases required an extended skin incision for the hand port to facilitate removal of the tumor. HALS is a tactile technique that enables protective tumor traction and surgical field development. The laparoscope enables observation in the retroperitoneal region of the upper abdomen, where maintaining a surgical field of view is anatomically difficult. HALS for large pheochromocytomas is a safe, minimally invasive, and curative management procedure. Key words：pheochromocytoma，laparoscopic surgery，hand-assisted laparoscopic surgery
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association)
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association), 2016
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association)
Surgical Case Reports
Background Distant metastasis is extremely rare for papillary thyroid microcarcinoma (PTMC) witho... more Background Distant metastasis is extremely rare for papillary thyroid microcarcinoma (PTMC) without lymph node metastasis or extrathyroidal extension, for which active surveillance (AS) is indicated. The evaluation of distant metastases in low-risk PTMC is controversial. A case of PTMC in which AS would have been performed if chest CT and lung surgery had not been performed is reported. Case presentation The patient was a 71-year-old woman undergoing follow-up in the Department of Thoracic Surgery at our hospital for multiple frosted glass shadows in both lung fields for one and a half years. To make a definitive diagnosis, thoracoscopic right middle lobectomy and left upper partial lobectomy were performed 4 and 6 months earlier, respectively. In both resected specimens, lung adenocarcinoma and small metastasis of papillary thyroid carcinoma (PTC) were found. The patient was transferred to our department for a thorough examination for PTC. Ultrasonography was performed to search fo...
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association), 2019
Aims:Postoperativenauseaandvomiting(PONV)areunpleasantsymptomscommoninwomenundergoingbreastcancer... more Aims:Postoperativenauseaandvomiting(PONV)areunpleasantsymptomscommoninwomenundergoingbreastcancersurgery.Weinvestigatedtheriskfactorsandevaluatedpreventivemeasuresas-sociatedwithPONVfollowingbreastcancersurgery.Method:Thisretrospectiveobservationalstudyin-cluded175womenwithbreastcancerwhounderwentbreastcancersurgery.BasedontheApfelscoring systemforPONV,thesewomenwereclassifiedintoahigh-andlow-riskgroup.Pharmacologicalprophylaxis was administered to 81 women in the "treatment group". Results:The incidence of PONV was 27.7%(95%confidenceinterval[CI]18.6-36.7%)inthenon-treatmentgroupand9.9%(95%CI3.4-16.4%) in the treatment group, and relative risk reduction was 64% (95% CI 25-83%). Multivariate analysis showedthatpharmacologicalprophylaxis(oddsratio0.15,95%CI0.06-0.39)andriskclassificationbased ontheApfelscore(oddsratio6.4,95%CI1.7-24.1)weresignificantriskfactorsforPONV.Conclusion: Theadministrationofpharmacologicalprophylaxisbasedonapre-surgicalscoringsystemwaseffective forthepreventionofPONV.
Endocrine Connections, 2022
Background Cancer-related fatigue is one of the most important issues for patients, but research ... more Background Cancer-related fatigue is one of the most important issues for patients, but research on this topic is sparse. This study aimed to determine the prevalence of fatigue in postoperative patients with papillary thyroid carcinoma (PTC) and to identify the clinical features associated with fatigue. Methods We conducted a cross-sectional study on 292 thyroid cancer survivors. Fatigue and quality of life were the study outcomes, measured using the Cancer Fatigue Scale (CFS) and the SF-36 version 2.0. Furthermore, correlations of demographic characteristics and hormonal data with the CFS scores were assessed by univariable and multivariable analyses. Results The prevalence of fatigue was 41.8% (95% CI: 36.1, 47.5). The CFS score was significantly correlated with the free T3 level (Pearson’s r = −0.123, 95% CI: −0.234, −0.008). Multiple regression analysis revealed that the free T3 level and having a job were significant predictors of the CFS score, with unstandardized regression ...
Cancers, 2021
The high incidence of germline variants in pheochromocytoma and paraganglioma (PPGL) has been rep... more The high incidence of germline variants in pheochromocytoma and paraganglioma (PPGL) has been reported mainly in Europe, but not among Japanese populations in Asia. We aimed to study the prevalence of germline variants in Japanese PPGL patients and the genotype–phenotype correlation. We examined 370 PPGL probands, including 43 patients with family history and/or syndromic presentation and 327 patients with apparently sporadic (AS) presentation. Clinical data and blood samples were collected, and the seven major susceptibility genes (MAX, SDHB, SDHC, SDHD, TMEM127, VHL, and RET) were tested using Sanger sequencing. Overall, 120/370 (32.4%) patients had pathogenic or likely pathogenic variants, with 81/327 (24.8%) in AS presentation. SDHB was the most frequently mutated gene (57, 15.4%), followed by SDHD (27, 7.3%), and VHL (18, 4.9%). The incidence of metastatic PPGL was high in SDHB carriers (21/57, 36.8%). A few unique recurrent variants (SDHB c.137G>A and SDHB c.470delT) were d...
Endocrine Journal, 2020
The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Pr... more The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flowcharts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence ()/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence ()/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.
Surgery Today, 2019
Purpose To establish if parathyroidectomy is beneficial for patient-reported outcomes (PROs), inc... more Purpose To establish if parathyroidectomy is beneficial for patient-reported outcomes (PROs), including quality of life (QoL), of patients with mild hypercalcemia ( < 1.0 mg/dl above the upper limit of reference ranges) caused by primary hyperparathyroidism without classic symptoms (mild PHPT). Methods We conducted a systematic review of the literature. Prospective studies were selected if PROs were measured before and after surgery and if the subpopulation of mild PHPT was clearly defined. Selected studies were appraised for their designs, PRO measures, and potential biases, as well as findings. Effect sizes were estimated to evaluate the extent of the benefits, if possible. Results Four randomized controlled trials and six observational studies were included in this analysis. Seven studies used the SF-36 to measure QoL and the other three used different scales. Quantitative data on outcomes were provided in the four observational studies, but effect sizes could not be estimated. A placebo effect of surgery was discussed in five studies. Statistically significant improvements in PROs were observed in all studies, but the clinical importance of the changes was not discussed in detail. Conclusions The surgical treatment of mild PHPT may be associated with improved PROs, but the clinical significance of the changes is not yet confirmed.
World journal of surgery, Jun 14, 2017
Whether total parathyroidectomy (TPTX) or subtotal parathyroidectomy (SPTX) should be performed f... more Whether total parathyroidectomy (TPTX) or subtotal parathyroidectomy (SPTX) should be performed for primary hyperparathyroidism (PHPT) in patients with multiple endocrine neoplasia type 1 (MEN1) is controversial. At our institution, the parathyroidectomy strategy is based on the number of enlarged intraoperative parathyroid glands. We retrospectively analyzed our parathyroidectomy procedures. Data of PHPT treatment in patients with MEN1 who underwent parathyroidectomy from 1982 to 2012 at our department were retrospectively collected. The data were grouped according to the surgical procedure: TPTX, SPTX, and less than SPTX (LPTX). TPTX or SPTX was selected based on the preoperative examination findings and number of enlarged intraoperative parathyroid glands. The outcomes were the disease-free survival (DFS) rate and postoperative calcium replacement rate based on Kaplan-Meier analysis for each type of surgical procedure. Forty-five patients were analyzed. The overall 5- and 10-year...
Endocrine journal, Jan 20, 2018
To assess the efficacy, safety, and pharmacokinetics of metyrosine (an inhibitor of catecholamine... more To assess the efficacy, safety, and pharmacokinetics of metyrosine (an inhibitor of catecholamine synthesis) in patients with pheochromocytoma/paraganglioma (PPGL), we conducted a prospective, multi-center, open-label study at 11 sites in Japan. We recruited PPGL patients aged ≥12 years requiring preoperative or chronic treatment, receiving α-blocker treatment, having baseline urinary metanephrine (uMN) or normetanephrine (uNMN) levels ≥3 times the upper limit of normal values, and having symptoms associated with excess catecholamine. Metyrosine treatment was started at 500 mg/day and modified according to dose-adjustment criteria up to 4,000 mg/day. The main outcome measure was the proportion of patients who achieved at least 50% reduction in uMN or uNMN levels from baseline. Sixteen patients (11 males/5 females) aged 12-86 years participated. After 12 weeks of treatment and at the last evaluation of efficacy, the primary endpoint was achieved in 31.3% of all patients, including 66...
Surgery, 1995
Anterior transabdominal exploration has traditionally been advocated as the standard procedure fo... more Anterior transabdominal exploration has traditionally been advocated as the standard procedure for pheochromocytoma. However, some authors claim that a flank extraperitoneal approach with accurate unilateral localization is justifiable. Retrospective analysis was performed on 87 patients with pheochromocytoma to determine the appropriateness of extraperitoneal exploration. There were 45 men and 42 women with a mean age of 44.7 years (range, 16 to 83 years). Fifteen patients (17.5%) had pheochromocytoma as a part of multiple endocrine neoplasia (MEN) type 2A, and four had familial pheochromocytoma, von Hippel-Lindau disease, or von Recklinghausen&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease. All tumors detected by preoperative localization studies were correctly identified and were resected through flank extraperitoneal (45 patients), transabdominal (28), thoracoabdominal (13), and posterior (1) approaches. Tumors were extraadrenal in 14, multiple in 22, bilateral in 12, and unequivocally malignant in 2 patients at the initial operation. Two patients died during the immediate postoperative period, giving an operative mortality of 2.3%. Two patients had persistent disease. During follow-up within a mean period of 5 years (range, 1 month to 13.7 years) 8 patients (9.1%) experienced recurrence or metastasis. Other than the patients with MEN 2, recurrence was not attributable to the operative approach. If a preoperative localization study is accurate, an extraperitoneal approach is justifiable for many patients with pheochromocytomas.
Folia Endocrinologica Japonica, 1993
International Journal of Colorectal Disease, 2017
International Journal of Colorectal Disease, 2016
This study seeks to evaluate lateral pelvic lymph node (LPLN) and perirectal lymph node (PRLN) st... more This study seeks to evaluate lateral pelvic lymph node (LPLN) and perirectal lymph node (PRLN) status on magnetic resonance imaging (MRI) as potential risk factors for lymph node metastasis. The subjects were 394 patients with lower rectal cancer who underwent MRI prior to mesorectal excision (combined with lateral pelvic lymph node dissection in 272 patients) at 6 institutes. No patients received neoadjuvant therapy. Cases were classified as cN(+) and cN(-) based on the short axis of the largest lymph node ≥5 and &amp;amp;amp;amp;lt;5 mm, respectively. LPLN and PRLN status and other clinicopathologic factors were analyzed by multivariate logistic regression. The importance of identified risk factors for lymph node metastasis was examined using the area under the curve (AUC). Independent risk factors for right LPLN metastasis included histopathological grade (G3 + G4), pPRLN(+), M1, cLPLN(+) [odds ratio (OR) 10.73, 95 % confidence interval (CI) 4.59-27.1], and those for left LPLN metastasis were age (&amp;amp;amp;amp;lt;64), histopathological grade (G3 + G4), pPRLN(+), and cLPLN(+) (OR 24.53, 95 % CI 9.16-77.7). ORs for cLPLN(+) were highest. The AUCs for right and left cLPLN status of 0.7484 (95 % CI 0.6672-0.8153) and 0.7904 (95 % CI 0.7088-0.8538), respectively, were significantly higher than those for other risk factors. In contrast, the ORs for cPRLN(+) and cPRLN status of 2.46 (95 % CI 1.47-4.18) and 0.6396 (95 % CI 0.5917-0.6848) were not much higher than for other factors. An LPLN-positive status with a short axis ≥5 mm on MRI is an important predictor of LPLN metastasis, but PRLN status is not a strong predictor of PRLN metastasis.
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association), 2013
Molecular and clinical oncology, 2016
The present study presented a 35-year-old female patient in whom fecal occult blood was detected ... more The present study presented a 35-year-old female patient in whom fecal occult blood was detected in a medical check-up. Colonoscopy revealed a superficial elevated-type tumor with central depression in the lower rectum. The tumor was diagnosed as T1 deep invasive cancer. No swollen lymph nodes or distant metastasis were found on computed tomography or [(18)F]-fluorodeoxyglucose-positron emission tomography with computed tomography. However, a swollen right lateral pelvic lymph node (LPLN; short axis 4 mm) was revealed on magnetic resonance imaging (MRI). This lymph node exhibited high intensity on diffusion-weighted imaging (DWI), suggesting metastasis. Low anterior resection, regional lymph node dissection and right LPLN dissection (LPLD) were performed. Histological analysis revealed metastasis in the right LPLN, as suggested by the high DWI intensity. The indication for LPLD in the current Japanese guidelines is based on the tumor location and depth of invasion (≥T3), however, no...
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Papers by Takahiro Okamoto