Association of low skeletal muscle mass with the presence of advanced colorectal neoplasm: integrative analysis using three skeletal muscle mass indices.

AIM: This study aimed to evaluate an association between colorectal neoplasm (CRN) and skeletal muscle mass using three widely accepted skeletal muscle mass indices (SMIs) in a large population at average risk. METHOD: We performed a cross-sectional study using a screening colonoscopy database of 33 958 asymptomatic subjects aged 40-75 years. Appendicular skeletal muscle mass (ASM) was measured using a bioelectrical impedance analyser. ASM adjusted for height squared (ASM/ht2 ), weight (ASM/wt) and body mass index (ASM/BMI) were used as indices for muscle mass. Logistic regression models were used to evaluate the association between SMIs and CRN. RESULTS: In a multivariable-adjusted model, the risk of an advanced CRN increased linearly with decreasing quartiles for all three SMIs. The adjusted odds ratios (ORs) for advanced CRN in quartiles 1, 2 and 3 of ASM/wt compared with that in quartile 4 were 1.279, 1.196 and 1.179, respectively (Ptrend  = 0.017); for ASM/BMI, ORs were 1.307, 1.144 and 1.091, respectively (Ptrend  = 0.002); and for ASM/ht2 , ORs were 1.342, 1.169 and 1.062, respectively (Ptrend  = 0.002). The risk of distally located advanced CRN was higher in quartile 1 than in quartile 4 for all three SMIs (ASM/wt, OR = 1.356; ASM/BMI, OR = 1.383; ASM/ht2 , OR = 1.430). CONCLUSION: Our study demonstrated that low skeletal muscle mass was consistently associated with the presence of advanced CRN in a population at average risk regardless of the operational definition of the SMI, and it was particularly associated with distal advanced CRN.

Navigation programs, are they helpful for perioperative care with thyroid cancer patients?

The purpose of this study was to develop and evaluate a navigation program for patients with thyroid cancer. The navigation program was developed following an analysis of the unmet needs of patients who underwent surgery for thyroid cancer. Ninety-nine patients in the control group received usual care, and 95 in the navigation group were managed with a navigation program during the perioperative period. The effectiveness of the navigation program was assessed by administering a questionnaire to both groups. Overall satisfaction scores were significantly higher in the navigation than in the control group (p = .025), as were satisfaction scores on the continuity of information (p < .001), the continuity of management (p = .002), the continuity of relationships with healthcare providers (p<.001), and patient empowerment (p < .001). The newly developed navigation program for patients with thyroid cancer was effective in raising satisfaction levels and in actively managing the disease during the perioperative period.

Frequent visualization of thyroglossal duct remnant on post-ablation 131I-SPECT/CT and its clinical implications.

AIM: To evaluate the frequency of thyroglossal duct remnant (TGDR) uptake on post-therapy (131)I-scintigraphy in thyroid cancer patients, to analyse the rate of persistent TGDR uptake on follow-up combined (131)I-single-photon emission CT/CT (SPECT/CT), and to identify the differential clinical characteristics between patients with positive and negative TGDR uptake on (131)I-SPECT/CT. MATERIALS AND METHODS: A total of 179 patients treated with total thyroidectomy for thyroid cancer were enrolled in the study. At (131)I-whole-body scan (WBS), TGDR uptake was defined as an increase in radioactivity at the midline of the neck versus the thyroid bed. TGDR uptake on (131)I- SPECT/CT was defined as the presence of radioactivity at the expected pathway of the thyroglossal duct without evidence of metastatic foci. Persistent TGDR uptake was confirmed when TGDR uptake on follow-up (131)I-SPECT/CT corresponded to previous TGDR uptake detected by post-therapy (131)I-SPECT/CT. RESULTS: At SPECT/CT, TGDR uptake was noted in 86 of 179 patients. Stimulated thyroglobulin (sTg) levels were significantly higher (p = 0.02) in patients with positive TGDR uptake. Persistent TGDR uptake on follow-up (131)I-SPECT/CT was noted in 15 of 86 patients; sTg levels were significantly higher (p = 0.03) in the patients with persistent TGDR uptake. CONCLUSION: TGDR uptake is frequently visualized on post-therapy (131)I-SPECT/CT images and can be resistant to (131)I ablation. TGDR uptake has the potential to result in an elevation of serum thyroglobulin levels. (131)I-SPECT/CT clarifies TGDR uptake without additional invasive procedures or imaging studies, eliminating confusion among clinicians for managing differentiated thyroid cancer patients.

The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy.

A health risk assessment of reclaimed municipal wastewater for industrial and miscellaneous use.

The study evaluated the safety of reclaimed water using health risk assessment and biotoxicity tests. The reclaimed water was produced from reverse osmosis and used in industrial and miscellaneous purposes. The health risk assessment was conducted based on the concentrations of detectable pollutants in reclaimed water in a hypothetical scenario. The estimated carcinogenic and non-carcinogenic risks are lower than the generally accepted level. Biotoxicity evaluation included three genotoxicity tests, a chronic toxicity test using medaka fishes, and a subchronic toxicity test using mice. The reclaimed water is not genetically toxic, and does not cause significant chronic effects on these model organisms. These results confirm the safety of using reclaimed water from municipal wastewater treatment plants.

Distinct features between longitudinally extensive transverse myelitis presenting with and without anti-aquaporin 4 antibodies.

OBJECTIVES: Longitudinally extensive transverse myelitis (LETM) with spinal cord lesions spanning three or more vertebral segments is a key feature of neuromyelitis optica (NMO). However, the role of anti-aquaporin 4 (anti-AQP4) antibody, a sensitive biomarker of NMO, in the conversion of LETM to NMO remains uncertain. METHODS: Thirty first-ever LETM patients were retrospectively analysed and divided into two groups according to the presence of anti-AQP4 antibodies. RESULTS: Eighteen (60%) patients presented with anti-AQP4 antibodies. Fifteen (83.33%) anti-AQP4 (+) LETM patients converted to NMO, while only three of 12 (25%, p = 0.002) anti-AQP4 (-) LETM patients progressed to NMO, over a mean follow-up period of 5.63 years. Seven (38.89%) anti-AQP4 (+) and one (8.33%) anti-AQP4 (-) LETM patients received interferon-ß1a treatment, respectively. Anti-AQP4 (+) LETM patients demonstrated a higher immunogamma globulin (IgG) index (0.68 ± 0.43 versus 0.47 ± 0.19, p = 0.018), annual relapse rate (0.72 ± 0.31 versus 0.42 ± 0.17, p = 0.01) and Kurtzke Expanded Disability Status Scale (4.28 ± 2.22 versus 2.67 ± 2.26, p = 0.031), than anti-AQP4 (-) LETM patients. In spinal magnetic resonance imaging (MRIs), more than half (58.33%) of the anti-AQP4 (+) LETM patients were observed to have central grey matter-predominant involvement in the axial view, while peripheral white matter-predominant involvement (51.85%) was the most common pattern observed in the anti-AQP4 (-) LETM patients. CONCLUSION: Anti-AQP4 (+) LETM demonstrated a high conversion rate to NMO (83.33%), suggesting that anti-AQP4 (+) LETM may represent an early, isolated syndrome of NMO spectrum disorder. The greater number of patients receiving interferon-ß treatment in anti-AQP4 (+) LETM may contribute to its high annual relapse rate.

Incidence and clinical behavior of papillary thyroid carcinoma in renal allograft recipients: a single center experience.

The chronic use of immunosuppressive therapy in transplant recipients increases the long-term risk for carcinoma. However, there is insufficient knowledge regarding the incidence and biological behavior of papillary thyroid carcinomas (PTC) in renal allograft recipients. In the present study we examined the incidence and biological behavior of PTCs among 1739 patients transplanted between January 1986 and December 1999 who had been followed for a mean period of 137 months (range, 84-238 months). During the follow-up, 129 (7.4%) recipients were identified to display posttransplantation malignancies, including 12 (0.7%) with PTCs. The 6 male and 6 female patients had a mean age of 41 years (range, 23-57 years). Nine cases (incidentalomas) were diagnosed based on ultrasonographic (US) screening. Eight of those 9 were TNM stage I, 2 of the 3 clinical carcinomas were TNM stage IVa. During a mean follow-up of 94 months (range, 18-159 months), 2 (16.7%) PTC patients developed locoregional recurrence, but no patients showed distant metastases. These data showed that recipients had a higher incidence of PTC compared with the general Korean population (0.7% vs 0.02%). Posttransplantation PTC tended to show no difference in gender distribution, and was often associated with aggressive lymphatic metastasis. However, most incidentalomas showed favorable treatment outcomes. In conclusion, routine surveillance of the thyroid gland using US screening is recommended to ensure early detection, treatment, and favorable prognosis of PTC.

Angiotensin-converting enzyme polymorphisms and risk of spontaneous deep intracranial hemorrhage in Taiwan.

BACKGROUND AND PURPOSE: This study examines whether angiotensin-converting enzyme (ACE) gene polymorphisms are associated with the risk of spontaneous deep intracerebral hemorrhage (SDICH) in Taiwan using a case-control study. METHODS: Totally, 217 SDICH patients and 283 controls were recruited. Associations of ACE A-240T and ACE I/D polymorphisms with SDICH were examined under the additive model and adjusted for gender, age, body mass index, total cholesterol level, smoking history, alcohol use, hypertension, and use of ACE inhibitors. RESULTS: Hypertension, diabetes mellitus, family history of spontaneous intracerebral hemorrhage (SICH), and low cholesterol level increase risk of female SDICH, whereas hypertension, alcohol use, smoking history, family history of SICH, and low cholesterol level are an important risk factor for male SDICH. After adjusting for covariates, only haplotype ACE T-D (OR = 2.7, 95% CI, 1.1-6.5, P = 0.02) was associated with female SDICH. CONCLUSIONS: This study demonstrates that environmental risk factors play a major role and ACE polymorphisms play a minor role in contributing risk of SDICH in Taiwan.

Substance P regulates macrophage inflammatory protein 3alpha/chemokine C-C ligand 20 (CCL20) with heme oxygenase-1 in human periodontal ligament cells.

Although substance P (SP), a potent proinflammatory peptide, is involved in inflammation and immune responses, the effect of SP on the expression of macrophage inflammatory protein 3alpha[MIP-3alpha, chemokine C-C ligand 20 (CCL20)] in periodontal ligament (PDL) cells is unknown. Equally enigmatic is the link between SP, the stress protein heme oxygenase-1 (HO-1), and CCL20 production. We investigated whether SP induces the release of chemokine CCL20 from immortalized PDL (IPDL) cells, and further clarify SP-mediated pathways. We also examined the relationship between HO-1 and CCL20 by treating PDL cells with SP. Incubating IPDL cells with SP increased expression of CCL20 mRNA and CCL20 protein in a dose-time-dependent manner. Highly selective p38 and extracellular-regulated kinase 1/2 (ERK1/2) inhibitors abrogated SP-induced expression of CCL20 in IPDL cells. SP is also responsible for initiating phosphorylation of IkappaB, degradation of IkappaB and activation of nuclear factor (NF)-kappaB. SP induced expression of HO-1 in both a concentration- and time-dependent manner, and CCL20 reflected similar patterns. The inductive effects of SP on HO-1 and CCL20 were enhanced by HO-1 inducer hemin and the membrane-permeable guanosine 3',5'-monophosphate (cGMP) analogue 8-bromo-cGMP. Conversely, this pathway was inhibited by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP IX) and the selective inhibitor of guanylate cyclase, 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one (ODQ). We report herein the pathway that connects SP along with other modulators of neuroimmunoregulation to the induction of HO-1 and the inflammatory mediator macrophage inflammatory protein (MIP)-3alpha/CCL20 in IPDL cells, which play an important role in the development of periodontitis or inflammation during orthodontic tooth movement.

Contribution of clinical screening to carrier detection in a large Chinese family with Fabry disease due to a novel alpha-galactosidase A gene deletion.

Diagnosis of heterozygous Fabry patients is difficult because of its variable clinical manifestations and overlapping serum alpha-galactosidase A (AGA) activity between carriers and non-carriers. We tried to facilitate diagnosis of heterozygous Fabry patients by detailed clinical examination. We analyzed clinical presentations, biochemical, electrophysiological and genetic characteristics of 16 patients with Fabry disease in a large Chinese family. Male patients demonstrated significantly higher pain scores, poorer renal function, and higher frequency of hypohidrosis and corpora angiokeratomas than female patients. Interestingly, all the males and females had corneal verticilata by slit lamp examination. However, there was no association of serum AGA activity with renal function or pain symptom scores. The results indicated that detailed ocular and neurological examination might provide an alternative way of detecting heterozygous patients. We also report a novel large deletion spanning across the joint of Alu repetitive elements in introns 1 and 2 with resultant exon 2 deletion in a Chinese family with Fabry disease.

Analysis of colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

BACKGROUND AND STUDY AIMS: Intestinal tuberculosis and Crohn's disease are chronic inflammatory bowel disorders that are difficult to differentiate from one another. This study aimed to evaluate the diagnostic value of various colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease. PATIENTS AND METHODS: Colonoscopic findings on initial work-up were prospectively recorded in patients with an initial diagnosis of either intestinal tuberculosis or Crohn's disease. These findings were analyzed after a final diagnosis of intestinal tuberculosis (n = 44) or Crohn's disease (n = 44) had been made after follow-up. RESULTS: Four parameters (anorectal lesions, longitudinal ulcers, aphthous ulcers, and cobblestone appearance) were significantly more common in patients with Crohn's disease than in patients with intestinal tuberculosis. Four other parameters (involvement of fewer than four segments, a patulous ileocecal valve, transverse ulcers, and scars or pseudopolyps) were observed more frequently in patients with intestinal tuberculosis than in patients with Crohn's disease. We hypothesized that a diagnosis of Crohn's disease could be made when the number of parameters characteristic of Crohn's disease was higher than the number of parameters characteristic of intestinal tuberculosis, and vice versa. Making these assumptions, we calculated that the diagnosis of either intestinal tuberculosis or Crohn's disease would have been made made correctly in 77 of our 88 patients (87.5 %), incorrectly in seven patients (8.0 %), and would not have been made in four patients (4.5 %). CONCLUSIONS: A systematic analysis of colonoscopic findings is very useful in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

Modulatory influence of sodium 2-propenyl thiosulfate from garlic on cyclooxygenase activity in canine platelets: possible mechanism for the anti-aggregatory effect.

We previously found that sodium 2-propenyl thiosulfate (2PTS) has an anti-aggregatory effect in vitro on both canine and human platelets at relatively low concentrations, but the extent of aggregation tends to return to the control level at high concentrations. To clarify the mechanism of this modulatory influence of 2PTS on the aggregation of platelets, we investigated the effects of 2PTS on cyclooxygenase (COX) activity and the reduced glutathione (GSH) concentration in canine platelets. Platelet COX activity was inhibited by 2PTS in a dose-dependent manner up to 0.1 mM, but tended to return to the control level at 1 mM. In contrast, the platelet GSH concentration decreased in a dose-dependent manner after treatment with 2PTS and a significant decrease was observed at 0.1 mM (P<0.05) and 1 mM (P<0.001). Furthermore, the activity of purified COX-1 was directly inhibited by addition of GSH in a dose-dependent manner. From these results, we conclude that the 2PTS-induced inhibition of platelet aggregation occurs as a result of inhibition of COX activity. Additionally, 2PTS may have a modulatory effect on platelet aggregation by affecting the platelet GSH concentration.

Postmortem study of the spinal cord showing snake-eyes appearance due to damage by ossification of the posterior longitudinal ligament and kyphotic deformity.

UNLABELLED: CLINICAL DESIGN: A case report. OBJECTIVES: To elucidate the clinical role of snake-eyes appearance in this case, correlation between radiological, clinical and postmortem study was performed. SETTING: Aichi, Japan. CASE REPORT: A 73-year-old man developed weakness and pain in the upper limbs due to kyphotic deformity secondary to laminectomy for cervical ossification of the posterior longitudinal ligament. Axial magnetic resonance imaging revealed snake-eyes appearance from C4 to C6. He died of acute myocardial infarction 3 months after anterior decompressive surgery. RESULTS: A postmortem examination of the cervical spinal cord showed small cystic six necrotic areas at the junction of the central gray matter and the ventrolateral posterior column, one in the right and one in the left, in association with neuronal loss in the anterior horn. CONCLUSIONS: Bilateral small intramedullary high-signal areas known as 'snake-eyes appearance' located around the central gray matter and the ventrolateral posterior column, are associated with neuronal loss in the compressed anterior horn that played an important role in worsening weakness of the upper limbs.

Melanotic neuroectodermal tumour of infancy in the maxilla: a case report.

A 4.5-month-old Chinese boy presented with a bulging mass in the anterior right maxillary region. Clinical features and incisional biopsy examination confirmed the diagnosis of melanotic neuroectodermal tumour of infancy (MNTI). The lesion had first been noted a month before the biopsy. The extent of the lesion was defined via computed tomography, and surgical excision was accomplished through a partial maxillectomy under general anaesthesia. The patient has been irregularly followed-up over the past 8 years, and no evidence of recurrence has been found, either by clinical examination or serial computed tomography scans. A bony defect and a lack of alveolar process were noted on the right side of the anterior maxilla. The patient displayed social withdrawal at school as a result of his partial anodontia. There have only been a limited number of reports on the dental rehabilitation of postoperative MNTI. We report a case of maxillary MNTI in which the need for dental rehabilitation was emphasized.

Atypical endoscopic features of rectal carcinoids.

BACKGROUND AND STUDY AIMS: It is not normally difficult to diagnose carcinoid tumors (well-differentiated endocrine neoplasms) of the rectum endoscopically, as they usually have a characteristic appearance. However, little is known about the atypical endoscopic findings in some rectal carcinoids and the present study was performed to analyze these. PATIENTS AND METHODS: The endoscopic findings in 67 consecutive patients with rectal carcinoids (37 men, 30 women; age range 23 - 76) were analyzed retrospectively. RESULTS: Tumor size ranged from 2 mm to 30 mm (average 7.4 mm). Of the 67 patients, 52 (78 %) displayed the characteristic endoscopic findings of smooth, round, sessile elevations covered with normal-appearing or yellow-discolored mucosa; in 15 (22 %) there were one or more atypical endoscopic findings. These included a semipedunculated appearance (n = 6), hyperemia (n = 5), a central depression (n = 6), erosion (n = 5), and ulceration (n = 4). Atypical findings were noted in none of 20 carcinoids &lambda< 5 mm in diameter; in six (20 %) of the 30 carcinoids between 5 mm and 9 mm; in six (43 %) of the 14 carcinoids between 10 mm and 19 mm; and in three (100 %) of the three carcinoids >/= 20 mm in diameter ( P < 0.001). Invasion into the muscularis propria or metastasis to the liver or lymph nodes occurred in three of the four patients with ulceration, but it was confirmed in only one of the 63 patients without ulceration ( P < 0.001). CONCLUSIONS: Atypical endoscopic appearances of rectal carcinoids are observed more frequently as the size of the tumor increases and a finding of ulceration may have a prognostic value.

Acceleration of superoxide generation in polymorphonuclear leukocytes and inhibition of platelet aggregation by alk(en)yl thiosulfates derived from onion and garlic in dogs and humans.

We recently identified sodium n-propyl thiosulfate (NPTS) and sodium 2-propenyl thiosulfate (2PTS) from boiled onion and garlic, respectively, as causative agents of hemolytic anemia in dogs. We present here data concerning the effects of these alk(en)yl thiosulfates on superoxide (O(2)(-)) generation in peripheral polymorphonuclear leukocytes (PMNs) and on adenosine 5'-diphosphate (ADP)-induced platelet aggregation in dogs and humans in vitro. Both NPTS and 2PTS increased O(2)(-) generation significantly (P<0.05 at 1mM NPTS, P<0.005 at 0.1 and 1mM 2PTS) and reduced its reaction time significantly (P<0.05 between 0.01 and 1mM NPTS and at 1mM 2PTS) in canine PMNs stimulated by phorbol 12-myristate 13-acetate, compared with the control without alk(en)yl thiosulfates. However, a tendency to return to the control level was observed at 10mM of the alk(en)yl thiosulfates in both O(2)(-) generation and its reaction time. Although NPTS and 2PTS did not exert any significant effect on the O(2)(-) generation in human PMNs, 2PTS reduced its reaction time significantly (P<0.05) at 1 and 10mM compared with the control, showing that 2PTS accelerated O(2)(-) generation in human PMNs. The difference in effects on O(2)(-) generation may be due to that in susceptibility to alk(en)yl thiosulfates between canine and human PMNs. On the other hand, NPTS and 2PTS were shown to significantly inhibit ADP-induced platelet aggregation at 0.01mM (P<0.01) in canine platelets and at 0.001-0.1mM (P<0.05) in human platelets. In contrast, the maximal aggregation percentage returned to the control level at 1mM of alk(en)yl thiosulfates in both canine and human platelets. From these results, we conclude that NPTS and 2PTS have the potential to promote immune functions and prevent cardiovascular diseases.

Ultrasonographic mass screening for thyroid carcinoma: a study in women scheduled to undergo a breast examination.

This study was carried out to clarify the sensitivity of ultrasonographic mass screening for thyroid carcinoma. Between December 1997 and July 1998, a total of 1401 subjects who were scheduled to undergo either a breast examination or a follow-up examination for breast cancer were enrolled in this study. Patients with thyroid nodules were classified into two groups according to their potential risk for malignancy based on the ultrasonographic findings. Ultrasonographic high-risk patients for thyroid cancer underwent an ultrasound guided fine-needle aspiration biopsy (FNAB) and were advised to undergo a thyroidectomy based on the FNAB results. The characteristics of the thyroid cancer patients detected by mass screening were then compared with those of 106 consecutive female patients with clinical thyroid cancer during the same period. Thyroid nodules were detected in 353 (25.2%) of the subjects, 94 (26.6%) of whom were placed in the high-risk group for thyroid cancer. Among the 94 high-risk patients, 43 underwent a thyroidectomy and 37 turned out to have thyroid carcinomas. The detection rate for thyroid cancer was 2.6% for all subjects. The tumor size was significantly smaller than that of the clinically detected cancer group (P < 0.05). Ultrasonographic mass screening for thyroid carcinoma in women who require breast examinations is thus considered to be effective for the detection of subclinical thyroid carcinoma.

Surgical decision-making on cerebral cavernous malformations.

This study is an attempt to clarify surgical decision-making on cerebral cavernous malformations based on the data available in the literature. Using a mathematical model, we calculated the morbidity-free survival curves of the patients harboring cerebral cavernous malformations. Using these survival curves, we calculated the morbidity-free life expectancies of the patients at certain age undergoing either natural course or surgery. For superficially located lesions, permissible surgical risks were very small ranging from 0.4 to 2.8 percent of combined morbidity and mortality. The surgical gain of morbidity free life expectancy was also very small (0.0-1.1 years) irrespective of patient's age or eloquence of the location. For deep lesions, the permissible risk of surgery was very large, ranging from 64.1% for a 20-year-old and 31.4% for a 60-year-old patient. The gain of morbidity-free life expectancy was also large for younger patients (17-25 years for 20-year-old patients), but this gain rapidly decreased as the patient's age grew older, becoming 1.1 to 3.1 years for 60-year-old patients. Surgery seems to be justified for younger patients with deep lesions. There seems to be little indication for surgery of superficial lesions as far as the risk of bleeding is concerned.

Minimally invasive open thyroidectomy.

We recently developed a new surgical technique for carrying out thyroidectomy, to minimize tissue trauma by obviating unnecessary neck exploration. This report describes our technique of performing minimally invasive open thyroidectomy and compares the results with those of conventional thyroidectomy. Minimally invasive open thyroidectomy was performed by making a small skin incision, 3.0-4.5cm long, and approaching the thyroid directly via a transverse division of the strap muscles without raising skin flaps. The outcomes of 466 patients who underwent a minimally invasive open thyroidectomy were retrospectively compared with those of 437 patients who underwent conventional thyroidectomy for various types of thyroid nodules. There was no significant difference in the extent of surgery between the group of patients who underwent minimally invasive thyroidectomy and the group of patients who underwent conventional thyroidectomy. However, the length of the skin incision, at 3.7 +/- 0.7 vs 9.6 +/- 3.3 cm, respectively, operative time, at 57.6 +/- 11.7 vs 85.2 +/- 32.3 min, respectively, blood loss, at 18.4 +/- 15.3 vs 43.1 +/- 21.8 ml, respectively, and hospital stay, at 1.6 +/- 0.5 vs 4.3 +/- 1.6 days, respectively, were significantly reduced in the minimally invasive open thyroidectomy group (P < 0.05). Moreover, the number of patients who required postoperative analgesia was significantly less in the minimally invasive open thyroidectomy group. These results show that minimally invasive open thyroidectomy provides surgeons with a clear operative field, and that it has proven to be simple, safe, and practical for selected patients.