Surgical navigation system for laparoscopic lateral pelvic lymph node dissection in rectal cancer surgery using laparoscopic-vision-tracked ultrasonic imaging.

BACKGROUND: Laparoscopic lateral pelvic lymph node dissection (LPLND) in rectal cancer surgery requires considerable skill because the pelvic arteries, which need to be located to guide the dissection, are covered by other tissues and cannot be observed on laparoscopic views. Therefore, surgeons need to localize the pelvic arteries accurately before dissection, to prevent injury to these arteries. METHODS: This report proposes a surgical navigation system to facilitate artery localization in laparoscopic LPLND by combining ultrasonic imaging and laparoscopy. Specifically, free-hand laparoscopic ultrasound (LUS) is employed to capture the arteries intraoperatively in this approach, and a laparoscopic vision-based tracking system is utilized to track the LUS probe. To extract the artery contours from the two-dimensional ultrasound image sequences efficiently, an artery extraction framework based on local phase-based snakes was developed. After reconstructing the three-dimensional intraoperative artery model from ultrasound images, a high-resolution artery model segmented from preoperative computed tomography (CT) images was rigidly registered to the intraoperative artery model and overlaid onto the laparoscopic view to guide laparoscopic LPLND. RESULTS: Experiments were conducted to evaluate the performance of the vision-based tracking system, and the average reconstruction error of the proposed tracking system was found to be 2.4 mm. Then, the proposed navigation system was quantitatively evaluated on an artery phantom. The reconstruction time and average navigation error were 8 min and 2.3 mm, respectively. A navigation system was also successfully constructed to localize the pelvic arteries in laparoscopic and open surgeries of a swine. This demonstrated the feasibility of the proposed system in vivo. The construction times in the laparoscopic and open surgeries were 14 and 12 min, respectively. CONCLUSIONS: The experimental results showed that the proposed navigation system can guide laparoscopic LPLND and requires a significantly shorter setting time than the state-of-the-art navigation systems do.

Development of a Semiautomatic Dura Mater Suturing Device for Preventing Cerebrospinal Fluid Leakage in Transsphenoidal Surgery.

Dural suturing in transsphenoidal surgery requires well-honed technical skills. We have developed a semiautomatic dural suturing device and confirmed its effectiveness by comparing it with the conventional method. This device significantly shortens the suturing time compared with the conventional method. The dural suturing time in transsphenoidal surgery could be decreased significantly by use of this novel device.

An educational intervention improved knowledge of dietary supplements in college students.

BACKGROUND: We have previously reported on the prevalence of dietary supplements among college students; it was deduced that their intake of supplements increased according to their grade (i.e., 13.1% in the first grade to 20.5% in the sixth grade). We also reported that some students had experienced adverse events in Japan due to their intake of these supplements. However, awareness of dietary supplements among college students remains limited, even among pharmaceutical students. Being appropriately educated about them is important for pharmaceutical students, both for themselves as well as for their future careers as pharmacists. METHODS: We conducted a lecture-based educational intervention about dietary supplements on 328 college students in Japan-184 from pharmaceutical science and 144 from environmental science or food and life science disciplines. The purpose of this study was to evaluate the effects of an educational intervention on college students' understanding of dietary supplements. The intervention involved a lecture that covered the quality of dietary supplements, how they differed from drugs, and a summary of their adverse events. The lecture was evaluated using a 14-question questionnaire. We then compared the pre- and post-intervention responses to the same questionnaire using a Wilcoxon signed-rank test. The questions were assessed using a Likert scale that ranged from "strongly agree" to "strongly disagree"; the latter being the preferred answer. RESULTS: Before the intervention had taken place, the students' understanding of dietary supplements was shown to be deficient. Conversely, post-intervention, their knowledge levels had significantly improved, especially concerning agreement on whether "Dietary supplements are safe because they are just food items". Pre-intervention, 2.7% strongly agreed and 37.5% agreed; post-intervention, 1.2% strongly agreed and 15.6% agreed. On whether "Dietary supplements made from natural ingredients or herbs are safe", at the pre-intervention stage 2.8% strongly agreed and 44.0% agreed and post-intervention, 2.2% strongly agreed and 16.9% agreed. On whether "Dietary supplements made from food items are safe", 4.0% strongly agreed and 43.6% agreed pre-intervention and 0.9% strongly agreed and 16.6% agreed post-intervention. Despite there being a greater number of pharmaceutical students who had a correct understanding of dietary supplements before the intervention, these students still showed improvement after the lecture. CONCLUSION: An intervention in the form of a single educational lecture has the capacity to improve college students' understanding of dietary supplements. It is important for pharmacists to be appropriately educated about dietary supplements when they consult with patients. We will evaluate the long-term effects of the intervention on the alumni (pharmacists) in a subsequent study.

[Evaluation of Safety Information of the Foods with Function Claims Based on Adverse Event Reports in Information System on Safety and Effectiveness for Health Foods Database].

Foods with Function Claims are allowed to label health claims based on scientific evidence evaluated by the manufacturers. To prevent health problems caused by inadequate use, the manufacturers should label proper safety information. To evaluate whether safety information is sufficiently provided, we conducted the adverse event review focused on popular functional ingredients using the database; Information system on safety and effectiveness for health food. The data suggested that causal factor of adverse events related to products containing soy isoflavone, ginkgo biloba extract and docosahexaenoic acid/eicosapentaenoic acid were overdose intake, concomitant use with certain medicines, and use by whom with an allergic predisposition. However, the safety information on the label was insufficient to prevent adverse events on each products' label. It is important not only to encourage food manufacturers to provide sufficient information based on safety review, but also to inform consumers about adverse events.

Novel clinical scoring system to identify patients with pneumothorax with suspicion for Birt-Hogg-Dubé syndrome.

BACKGROUND AND OBJECTIVE: Birt-Hogg-Dubé syndrome (BHDS) is a rare hereditary disease that presents with multiple lung cysts and pneumothorax (PTX). Although some reports propose that findings from chest computed tomography enable one to distinguish BHDS from primary spontaneous pneumothorax (PSP), it is still unclear whether clinical features are useful for identifying patients with suspicion of BHDS from those with PTX. METHODS: We retrospectively reviewed the medical records of patients with PTX who underwent video-assisted thoracoscopic surgery at Nissan Tamagawa Hospital from January 2012 to December 2015. RESULTS: We identified a total of 1141 patients with PTX, including 54 with BHDS and 517 with PSP. Among them, logistic regression analysis segregated five features that were significantly associated with BHDS: familial history of PTX, past history of bilateral PTX, age at the first episode of PTX (≥25 years old (y.o.)), body mass index (≥18.5) and gender (female). We assigned scores of 3, 3, 2, 2 and 1 to the five features, respectively, to establish a system with a calculated score from 0 to 11. The cut-off value of a calculated score ≥ 4 yielded the highest sensitivity of 93% and specificity of 86%. Receiver operating characteristic (ROC) analysis showed the area under the curve reflecting an accuracy of this diagnostic test as 0.953. CONCLUSION: BHDS has several clinical features distinct from PSP. Our scoring system consists of only five clinical variables that are easily evaluated and efficiently separate BHDS patients from those who have PTX without relying on an imaging study. Further prospective study is needed to confirm our findings.

Oxidized regenerated cellulose induces pleural thickening in patients with pneumothorax: possible involvement of the mesothelial-mesenchymal transition.

PURPOSE: The pleural covering technique, i.e., wrapping a part of or the entire surface of the lung with oxidized regenerative cellulose (ORC), reinforces visceral pleura through pleural thickening for patients with pneumothorax and cystic lung diseases. However, it remains undetermined how ORC induces pleural thickening. METHODS: A histopathological examination was performed for lung specimens from patients who had recurrent pneumothoraces after pleural covering and re-operation (n = 5). To evaluate the influence of ORC on the pleura in vitro, we used MeT-5A cells (a human pleural mesothelial cell line). RESULTS: Pleural thickening was confirmed in all lung specimens examined. Three months after covering, the thickened pleura showed inflammatory cell infiltration, proliferation of myofibroblasts, and expression of fibronectin and TGF-ß. However, after 1 year, those findings virtually disappeared, and the thickened pleura was composed mainly of abundant collagen. When MeT-5A cells were cultured in ORC-immersed medium, their morphology changed from a cobblestone to spindle-shaped appearance. The expression of E-cadherin decreased, whereas that of N-cadherin, α-smooth muscle actin, and fibronectin increased, suggesting mesothelial-mesenchymal transition (Meso-MT). CONCLUSIONS: Our results suggest that Meso-MT may be involved as a mechanism of pleural thickening induced by pleural covering with ORC.

Behaviors of consumers, physicians and pharmacists in response to adverse events associated with dietary supplement use.

BACKGROUND: The prevalence of dietary supplements has increased in Japan, and, as a consequence, the adverse events associated with dietary supplement use have become more prominent. Severe adverse events must be reported to the Japanese government via public health centers. However, the number of cases reported to the Japanese government is limited. To clarify this discrepancy, we conducted an internet questionnaire, and surveyed how consumers, physicians and pharmacists acted when they or their patients developed adverse events due to dietary supplement use. METHODS: This study was completed by 2732 consumers, 515 physicians, and 515 pharmacist via internet surveillance on November 2015. RESULTS: Although 8.8% of consumers developed adverse events including diarrhea, constipation, stomachache, headache, and nausea and vomiting, most of them did not report their adverse events to public health centers. However, some consumers went to hospitals because of adverse events. We also surveyed how physicians and pharmacists acted when their patients developed adverse events due to dietary supplement use. Most physicians and pharmacists did not report these cases to public health centers because they were unable to definitively prove the cause-and-effect relationship of these adverse events. Furthermore, some physicians and pharmacists did not know how or where to report these adverse events. CONCLUSIONS: We clarified the reasons for the limited number of reports of adverse events to the Japanese government in this survey. It is important to encourage not only consumers, but also physicians and pharmacists to report adverse events to public health centers. In addition, an analyzing tool of cause-and-effect relationships might be helpful for physicians and pharmacists.

Concept design of robotic modules for needlescopic surgery.

BACKGROUND: Many minimally invasive surgical procedures and assisting robotic systems have been developed to further minimize the number and size of incisions in the body surface. This paper presents a new idea combining the advantages of modular robotic surgery, single incision laparoscopic surgery and needlescopic surgery. MATERIAL AND METHODS: In the proposed concept, modules carrying therapeutic or diagnostic tools are inserted in the abdominal cavity from the navel as in single incision laparoscopic surgery and assembled to 3-mm needle shafts penetrating the abdominal wall. RESULTS: A three degree-of-freedom robotic module measuring 16 mm in diameter and 51 mm in length was designed and prototyped. The performance of the three connected robotic modules was evaluated. CONCLUSION: A new idea of modular robotic surgery was proposed, and demonstrated by prototyping a 3-DOF robotic module. The performance of the connected robotic modules was evaluated, and the challenges and future work were summarized.

Isolation of individual cellular components from lung tissues of patients with lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease entailing cystic destruction of the lungs and progressive respiratory failure. LAM lungs are histologically characterized by the proliferation of smooth muscle-like cells (LAM cells) and an abundance of lymphatic vessels. To elucidate the pathophysiological processes of LAM, cell-type-specific analyses are required. However, no method exists for isolating the individual types of cells in LAM lesions. Therefore, we established a fluorescence-activated cell sorting (FACS)-based method for the direct isolation of LAM cells and other various cellular components from LAM-affected lung tissue. We obtained LAM-affected lung tissue from resections or transplant recipients and prepared single-cell suspensions. FACS, immunohistochemical, and molecular analysis were used cooperatively to isolate HMB45-positive LAM cells with tuberous sclerosis complex (TSC) 2 loss of heterozygosity (LOH). Using a combination of antibodies against an epithelial cell adhesion molecule (EpCAM) and podoplanin, we fractionated CD45-negative lung cells into three groups: lymphatic endothelial cells (LEC) (EpCAM(-)/podoplanin(hi) subset), alveolar type II cells (EpCAM(hi)/podoplanin(-) subset), and mesenchymal cells (EpCAM(-)/podoplanin(-/low) subset). During subsequent analysis of HMB45 expression, as a LAM-specific marker, we clearly identified LAM cells in the mesenchymal cell population. We then discovered that CD90(+)/CD34(-) cells in the mesenchymal cell population are not only positive for HBM45 but also had TSC2 LOH. These isolated cells were viable and subsequently amenable to cell culture. This method enables us to isolate LAM cells and other cellular components, including LAM-associated LEC, from LAM-affected lung tissues, providing new research opportunities in this field.

Detection of low-prevalence somatic TSC2 mutations in sporadic pulmonary lymphangioleiomyomatosis tissues by deep sequencing.

Lymphangioleiomyomatosis (LAM) (MIM #606690) is a rare lung disorder leading to respiratory failure associated with progressive cystic destruction due to the proliferation and infiltration of abnormal smooth muscle-like cells (LAM cells). LAM can occur alone (sporadic LAM, S-LAM) or combined with tuberous sclerosis complex (TSC-LAM). TSC is caused by a germline heterozygous mutation in either TSC1 or TSC2, and TSC-LAM is thought to occur as a result of a somatic mutation (second hit) in addition to a germline mutation in TSC1 or TSC2 (first hit). S-LAM is also thought to occur under the two-hit model involving a somatic mutation and/or loss of heterozygosity in TSC2. To identify TSC1 or TSC2 changes in S-LAM patients, the two genes were analyzed by deep next-generation sequencing (NGS) using genomic DNA from blood leukocytes (n = 9), LAM tissue from lung (n = 7), LAM cultured cells (n = 4), or LAM cell clusters (n = 1). We identified nine somatic mutations in six of nine S-LAM patients (67 %) with mutant allele frequencies of 1.7-46.2 %. Three of these six patients (50 %) showed two different TSC2 mutations with allele frequencies of 1.7-28.7 %. Furthermore, at least five mutations with low prevalence (<20 % of allele frequency) were confirmed by droplet digital PCR. As LAM tissues are likely to be composed of heterogeneous cell populations, mutant allele frequencies can be low. Our results confirm the consistent finding of TSC2 mutations in LAM samples, and highlight the benefit of laser capture microdissection and in-depth allele analyses for detection, such as NGS.

Benign clear cell "sugar" tumor of the lung in a patient with Birt-Hogg-Dubé syndrome: a case report.

BACKGROUND: Birt-Hogg-Dubé (BHD) syndrome is a rare inherited autosomal genodermatosis and caused by germline mutation of the folliculin (FLCN) gene, a tumor suppressor gene of which protein product is involved in mechanistic target of rapamycin (mTOR) signaling pathway regulating cell growth and metabolism. Clinical manifestations in BHD syndrome is characterized by fibrofolliculomas of the skin, pulmonary cysts with or without spontaneous pneumothorax, and renal neoplasms. There has been no pulmonary neoplasm reported in BHD syndrome, although the condition is due to deleterious sequence variants in a tumor suppressor gene. Here we report, for the first time to our knowledge, a patient with BHD syndrome who was complicated with a clear cell "sugar" tumor (CCST) of the lung, a benign tumor belonging to perivascular epithelioid cell tumors (PEComas) with frequent causative relation to tuberous sclerosis complex 1 (TSC1) or 2 (TSC2) gene. CASE PRESENTATION: In a 38-year-old Asian woman, two well-circumscribed nodules in the left lung and multiple thin-walled, irregularly shaped cysts on the basal and medial area of the lungs were disclosed by chest roentgenogram and computer-assisted tomography (CT) during a preoperative survey for a bilateral faucial tonsillectomy. Analysis of the resected tumor showed large polygonal cells with clear cytoplasm proliferating in a solid pattern. Immunohistochemistry revealed that these tumor cells were positive for microphthalmia-transcription factor, S100, and CD1a but negative for HMB45, indicating that the tumor was a CCST. Genetic testing indicated that the patient had a germline mutation on exon 12 of the FLCN gene, i.e., insertion of 7 nucleotides (CCACCCT) (c.1347_1353dupCCACCCT). Direct sequencing of the FLCN exon 12 using genomic DNA obtained from her microdissected CCST cells clearly revealed loss of the wild-type FLCN sequence, which confirmed complete functional loss of the FLCN gene. On the other hand, no loss of heterozygosity around TCS1- or TSC2-associated genetic region was demonstrated. CONCLUSION: To our knowledge, this is the first report of CCST of the lung in a patient with BHDS, indicating that CCST should be added to the spectrum of pulmonary manifestations of BHDS.

Self-contained image mapping of placental vasculature in 3D ultrasound-guided fetoscopy.

BACKGROUND: Surgical navigation technology directed at fetoscopic procedures is relatively underdeveloped compared with other forms of endoscopy. The narrow fetoscopic field of views and the vast vascular network on the placenta make examination and photocoagulation treatment of twin-to-twin transfusion syndrome challenging. Though ultrasonography is used for intraoperative guidance, its navigational ability is not fully exploited. This work aims to integrate 3D ultrasound imaging and endoscopic vision seamlessly for placental vasculature mapping through a self-contained framework without external navigational devices. METHODS: This is achieved through development, integration, and experimentation of novel navigational modules. Firstly, a framework design that addresses the current limitations based on identified gaps is conceptualized. Secondly, integration of navigational modules including (1) ultrasound-based localization, (2) image alignment, and (3) vision-based tracking to update the scene texture map is implemented. This updated texture map is projected to an ultrasound-constructed 3D model for photorealistic texturing of the 3D scene creating a panoramic view of the moving fetoscope. In addition, a collaborative scheme for the integration of the modular workflow system is proposed to schedule updates in a systematic fashion. Finally, experiments are carried out to evaluate each modular variation and an integrated collaborative scheme of the framework. RESULTS: The modules and the collaborative scheme are evaluated through a series of phantom experiments with controlled trajectories for repeatability. The collaborative framework demonstrated the best accuracy (5.2 % RMS error) compared with all the three single-module variations during the experiment. Validation on an ex vivo monkey placenta shows visual continuity of the freehand fetoscopic panorama. CONCLUSIONS: The proposed developed collaborative framework and the evaluation study of the framework variations provide analytical insights for effective integration of ultrasonography and endoscopy. This contributes to the development of navigation techniques in fetoscopic procedures and can potentially be extended to other applications in intraoperative imaging.

A New Suturing Device for Small Arteries.

Endoscope-assisted surgery and robot-assisted surgery are not common in cardiac surgery, particularly coronary artery bypass grafting, because of the complex nature of the procedures. We developed a new suturing device that allows for easy performance of such cardiac surgeries in comparison with conventional suturing methods. A total of 63 rabbits were used in this study. The right carotid artery was bypassed using the same side of the jugular vein under endoscopic guidance. Of these, 48 rabbits were operated on using the new devices and 15 rabbits were operated on using conventional polypropylene sutures. The proximal suturing time was 16.6 ± 5.3 minutes in the group that underwent surgery using the new device (group D) and 22.8 ± 7.6 minutes in the control group (group C; P < 0.05). The distal suture time was 16.3 ± 4.2 minutes in group D and 22.8 ± 6.0 minutes in group C (P < 0.05). The operation time was 113.0 ± 15.8 minutes in group D and 136.7 ± 20.6 minutes in group C (P < 0.05). Graft flow was 19.9 ± 12.8 mL/minute in group D and 12.1 ± 11.3 mL/minute in group C (P < 0.05). Thus, the operation time and the suture time differed significantly between the groups. This device provides advantages in endoscopic surgery compared to the conventional suture method.

All-cause mortality increased by environmental cadmium exposure in the Japanese general population in cadmium non-polluted areas.

The aim of the present study was to evaluate the effect of environmental cadmium (Cd) exposure indicated by urinary Cd on all-cause mortality in the Japanese general population. A 19-year cohort study was conducted in 1067 men and 1590 women aged 50 years or older who lived in three cadmium non-polluted areas in Japan. The subjects were divided into four quartiles based on creatinine adjusted U-Cd (µg g(-1) cre). The hazard ratio (HR) and 95% confidence interval (CI) for continuous U-Cd or the quartiles of U-Cd were estimated for all-cause mortality using a proportional hazards regression.The all-cause mortality rates per 1000 person years were 31.2 and 15.1 in men and women, respectively. Continuous U-Cd (+1 µg g(-1) cre) was significantly related to the all-cause mortality in men (HR 1.05, 95% CI: 1.02-1.09) and women (HR 1.04, 95% CI: 1.01-1.07). Furthermore in men, the third (1.96-3.22 µg g(-1) cre) and fourth quartile (≥3.23 µg g(-1) cre) of U-Cd showed a significant, positive HR (third: HR 1.35, 95% CI: 1.03-1.77, fourth: HR 1.64, 95% CI: 1.26-2.14) for all-cause mortality compared with the first quartile (<1.14 µg g(-1) cre). In women, the fourth quartile of U-Cd (≥4.66 µg g(-1) cre) also showed a significant HR (1.49, 95% CI 1.11-2.00) for all-cause mortality compared with the first quartile (<1.46 µg g(-1) cre).In the present study, U-Cd was significantly associated with increased mortality in the Japanese general population, indicating that environmental Cd exposure adversely affects the life prognosis in Cd non-polluted areas in Japan.

Vitamin C prevents cigarette smoke-induced pulmonary emphysema in mice and provides pulmonary restoration.

Vitamin C (VC) is a potent antioxidant and is essential for collagen synthesis. We investigated whether VC treatment prevents and cures smoke-induced emphysema in senescence marker protein-30 knockout (SMP30-KO) mice, which cannot synthesize VC. Two smoke-exposure experiments using SMP30-KO mice were conducted. In the first one (a preventive study), 4-month-old mice received minimal VC (0.0375 g/l) [VC(L)] or physiologically sufficient VC (1.5 g/l) [VC(S)] and exposed to cigarette smoke or smoke-free air for 2 months. Pulmonary evaluations followed when the mice were 6 months of age. The second study began after the establishment of smoke-induced emphysema (a treatment study). These mice no longer underwent smoke exposure but received VC(S) or VC(L) treatment for 2 months. Morphometric analysis was performed, and measurements of oxidative stress, collagen synthesis, and vascular endothelial growth factor in the lungs were evaluated. Chronic smoke exposure caused emphysema (29.6% increases of mean linear intercepts [MLI] and 106.5% increases of destructive index compared with the air-only group) in 6-month-old SMP30-KO mice, and this emphysema closely resembled human chronic obstructive pulmonary disease. Smoke-induced emphysema persisted in the VC(L) group after smoking cessation, whereas VC treatment provided pulmonary restoration (18.5% decrease of MLI and 41.3% decrease of destructive index compared with VC(L) group). VC treatment diminished oxidative stress, increased collagen synthesis, and improved vascular endothelial growth factor levels in the lungs. Our results suggest that VC not only prevents smoke-induced emphysema in SMP30-KO mice but also restores emphysematous lungs. Therefore, VC may provide a new therapeutic strategy for treating chronic obstructive pulmonary disease in humans.

Characterization of pulmonary cysts in Birt-Hogg-Dubé syndrome: histopathological and morphometric analysis of 229 pulmonary cysts from 50 unrelated patients.

AIMS: To characterize the pathological features of pulmonary cysts, and to elucidate the possible mechanism of cyst formation in the lungs of patients with Birt-Hogg-Dubé syndrome (BHDS), a tumour suppressor gene syndrome, using histological and morphometric analyses. METHODS AND RESULTS: We evaluated 229 lung cysts from 50 patients with BHDS and 117 from 34 patients with primary spontaneous pneumothorax (PSP) for their number, size, location and absence or presence of inflammation. The BHDS cysts abutted on interlobular septa (88.2%) and had intracystic septa (13.6%) or protruding venules (39.5%) without cell proliferation or inflammation. The frequencies of these histological characteristics differed significantly from those seen in the lungs of patients with PSP (P < 0.05). Although the intrapulmonary BHDS cysts were smaller than the subpleural BHDS cysts (P < 0.001), there was no difference in size between them when there was no inflammation. The number of cysts diminished logarithmically and the proportion of cysts with inflammation increased as their individual sizes became greater (P < 0.05). CONCLUSIONS: These results imply that the BHDS cysts are likely to develop in the periacinar region, an anatomically weak site in a primary lobule, where alveoli attach to connective tissue septa. We hypothesize that the BHDS cysts possibly expand in size as the alveolar walls disappear at the alveolar-septal junction, and grow even larger when several cysts fuse.

Diameters of lingual, facial, and maxillary arteries measured according to an objective protocol on 3D computed tomography angiography images.

PURPOSE: Retrograde superselective intra-arterial chemoradiotherapy is a radical treatment for advanced oral cancer. The catheter tip is placed into tumor-feeding arteries-the lingual, facial, or maxillary arteries. The diameter of the tumor-feeding arteries newly bifurcated from the external carotid artery is crucial for determining the requirement of a catheter navigation system. This study aimed to measure the diameter and distribution of the tumor-feeding artery according to an objective protocol using 3D computed tomography angiography images reproducibly. METHODS: Angiographic data of 20 noncatheterized carotid arteriesof 10 randomly selected patients were analyzed. We followed the external carotid artery to the entrance of each feeding artery to determine the center point where the artery diameter was measured. The diameter of the optimum circle measured at the adopted center point was taken as the diameter of each tumor-feeding artery. RESULTS: The diameters (mean ± standard deviation) were 3.5 ± 0.45, 2.9 ± 0.56, and 3.5 ± 0.56 mm for the maxillary, lingual, and facial arteries, respectively. The diameters of the maxillary and facial arteries were similar (p = 0.877), whereas the diameter of the lingual artery was smaller than that of the maxillary and facial arteries (p < 0.001). CONCLUSION: The findings of this study will be beneficial in determining the need of a new catheter navigation system and diameter of catheters to be used in the clinical practice. From the viewpoint of measurement automation and reproducibility, 3DCTA vessel measurement taken according to the proposed protocol was considered to be effective.

Tissue histology on the correlation between fracture energy and elasticity.

PURPOSE: Preemptively estimating tissue damage is crucial for a safe surgical procedure. We previously investigated the possibility of estimating the fracture energies of biological tissues based on their elasticities. However, the reason behind the presence of these correlations is poorly understood. In this study, we investigate the effect of a tissue's histology on the correlation between the fracture energy and elasticity. We hypothesize that two tissues with similar fibrous structure will show a similar correlation between the fracture energy and elasticity. METHODS: Porcine duodenum were used for this study. Two tensile tests were performed for each porcine duodenum specimen to determine its elasticity and tearing energy. The correlation between fracture energy and elasticity was then investigated using the results from the mechanical tests. Furthermore, duodenum specimens were fixed in 10% formalin while under tension. Microscopic images were then taken to visualize the fibrous structure within the duodenum tissues under tension. RESULTS: The results from the tensile test showed that the fracture energy had an isotropic positive and linear correlation with the elasticity to the negative 0.5th power (R2 = 0.89), which was also previously reported in small intestinal (jejunum) specimens. Furthermore, the tearing patterns of the duodenum were identical to the ones reported in the jejunum. Hematoxylin and eosin staining on tissues fixed under tension showed that the endomysium fibers are involved in providing resistance toward traction. CONCLUSION: Through mechanical tests, we showed that porcine duodenum tissues also have a correlation between its fracture energy and elasticity. We also discussed that the histological structure of a tissue is an important factor that dictates how the tearing energy of a tissue will correlate to the elasticity. We understood that since the tearing mechanism between the duodenum and jejunum was similar, the correlations between their fracture energies and elasticities were also similar.