Preventive Effects of Bioabsorbable Anti-Adhesion Barriers on Bowel Obstruction After Colectomy in Colon Cancer Patients: A Retrospective Cohort Study Using an Insurance Claims Database.

PURPOSE: Postoperative adhesions can be prevented by the use of bioabsorbable anti-adhesion barriers. Although the occurrence of postoperative bowel obstruction is an important concern for patients, at the time of approval of anti-adhesion barriers, its effectiveness in preventing postoperative bowel obstruction had not been evaluated. We aimed to retrospectively evaluate the incidence of bowel obstruction after colectomy in patients with colon cancer using an insurance claims database. METHODS: This retrospective cohort study analyzed the data of colon cancer patients (between 2005 and 2017 from a national insurance claims database) who underwent colectomies to compare the proportion of individuals with postoperative bowel obstruction between the barrier and no barrier groups. RESULTS: Of the 587 patients who met the inclusion criteria, 308 and 279 patients were identified as the barrier and no barrier groups, respectively. The incidence of postoperative bowel obstruction was significantly lower in the barrier group (log-rank test, P = 0.0483). The cumulative incidence of postoperative bowel obstruction 37 months after the initial colectomy was 6.1% and 10.9% in the barrier and no barrier groups, respectively. Moreover, consistent results were obtained in the matched cohort. CONCLUSION: In colectomies for patients with colon cancer, the use of anti-adhesion barriers could significantly reduce the incidence of postoperative bowel obstruction. Evaluations using insurance claims databases could provide important information on outcomes following implementation of medical devices.

Hard-to-heal wound treatment medical devices: clinical trial protocol in Japan.

In consultation with academia and the Pharmaceuticals and Medical Devices Agency (PMDA), we have developed guidance for drafting protocols for clinical trials concerning medical devices for the healing of hard-to-heal wounds without ischaemia. The guidance summarises the validity of single-arm trials for hard-to-heal wounds, the definition of hard-to-heal wounds without ischaemia, methods of patient enrolment and clinical endpoints. This review focuses on the logical thinking process that was used when establishing the guidance for improving the efficiency of clinical trials concerning medical devices for hard-to-heal wounds. We particularly focused on the feasibility of conducting single-arm trials and also tried to clarify the definition of hard-to-heal wounds. If the feasibility of randomised control trials is low, conducting single-arm trials should be considered for the benefit of patients. In addition, hard-to-heal wounds were defined as meeting the following two conditions: wounds with a wound area reduction <50% at four weeks despite appropriate standards of care; and wounds which cannot be closed by a relatively simple procedure (for example, suture, skin graft and small flaps). Medical devices for hard-to-heal wound healing are classified into two types: (1) devices for promoting re-epithelialisation; and (2) devices for improving the wound bed. For medical devices for promoting re-epithelialisation, we suggest setting complete wound closure, percent wound area reduction or distance moved by the wound edge as the primary endpoint in single-arm trials for hard-to-heal wounds. For medical devices for improving the wound bed, we suggest setting the period in which wounds can be closed by secondary intention or a simple procedure, such as the primary endpoint.

Independent Factors for In-Hospital Death Following Drug-Eluting Stent Thrombosis From the Japanese Adverse Event Report System.

BACKGROUND: Stent thrombosis (ST) is a serious complication after drug-eluting stents (DES) implantation. To identify the risk factors of mortality following ST, we evaluated adverse event reports used for safety measures after approval.Methods and Results:Between July 2004 and August 2019, 2,887 ST case reports were submitted to the Pharmaceutical and Medical Device Agency. Reports of probable or possible ST (n=604), with insufficient data regarding in-hospital outcome or duration between procedure and ST occurrence (n=37) or duplicate reports (n=191) were excluded. Accordingly, 2,045 reports with definite ST were analyzed. Among the subjects, there were 286 in-hospital deaths (14.0%). Multivariate logistic regression analysis revealed that left main trunk (LMT) (odds ratio [OR]: 4.76, 95% confidence interval [CI]: 3.26-6.96), chronic heart failure (CHF) (OR: 2.88, 95% CI: 1.61-5.14), hemodialysis (OR: 2.69, 95% CI: 1.66-4.36), prior stroke (OR: 2.28, 95% CI: 1.15-4.51), over 70 years old (OR: 1.62, 95% CI: 1.22-2.16), and right coronary artery (OR: 0.41, 95% CI: 0.27-0.63) were independent factors for in-hospital death after DES-ST. CONCLUSIONS: LMT, CHF, hemodialysis, prior stroke, and older age were independently associated with higher risk of in-hospital death following DES-ST. If target patients have these factors, maximum preventive strategies against ST occurrence, including adequate dual-antiplatelet therapy duration and optimal DES deployment procedures, are required.

Patient and lesion characteristics in late/very late stent thrombosis with everolimus-eluting stents from real-world adverse event reporting.

BACKGROUND: Stent thrombosis (ST) is a rare but serious complication after deployment of a drug-eluting stent. The features of ST after implantation of an everolimus-eluting stent (EES) have not been fully elucidated. METHODS: A comprehensive survey of real-world adverse event reporting with conditions for approval under the Pharmaceuticals and Medical Devices Act identified 490 cases of ST with EES. A total of 370 patients with definite ST after EES implantation [287 with early (E)ST (within 30 days), 54 with late (L)ST (31-365 days), and 29 with very late (VL)ST (over 1 year)] were divided into an EST group and an LST/VLST group to compare the patients and lesions characteristics. RESULTS: The frequency of patients with hemodialysis and in-stent restenosis (ISR) lesions were significantly higher in the LST/VLST group than in the EST group (hemodialysis, 22.9% vs 2.7%, p = 0.0001; ISR lesions, 25.9% vs 9.4%, p = 0.0001). Characteristic demographic factors for LST/VLST versus EST identified by multivariable model were hemodialysis and ISR lesions (hemodialysis: odds ratio 7.348, 95% confidence interval 2.458-21.968, p = 0.0001; ISR lesions: odds ratio, 2.490, 95% confidence interval 1.100-5.638, p = 0.027). The in-hospital death rates from ST were not significantly different between the EST group and the LST/VLST group (EST, 15% vs LST/VLST, 21.7%, p = 0.147). CONCLUSIONS: Patient-related and lesion-related characteristics were significantly different between EST and LST/VLST. Data collection from adverse event reporting could be a helpful strategy for evaluation of this serious but rare complication.

Learning Curve for Transcatheter Aortic Valve Implantation Under a Controlled Introduction System　- Initial Analysis of a Japanese Nationwide Registry.

BACKGROUND: The introduction of transcatheter aortic valve implantation (TAVI) into Japan was strictly controlled to optimize patient outcomes. The goal of this study was to assess if increasing experience during the introduction of this procedure was associated with outcomes.Methods and Results:The initial 1,752 patients registered in the Japanese national TAVI registry were included in the study. The association between operator procedure number and incidence of the early safety endpoint at 30 days (ESE30) as defined in the Valve Academic Research Consortium-2 consensus document was evaluated. Patients were divided into 4 groups by quartiles of procedure count (Groups I-IV in order of increasing number of procedures). Median patient age was 85 years, and 30.5% were male. The 30-day mortality rate was 1.4% (n=24), and 78 patients (7.9%) experienced 95 ESE30. Among the variables included in the model, ESE30 was associated with non-transfemoral approach (P=0.004), renal dysfunction (Cr >2.0 mg/dL) (P=0.01) and NYHA class III/IV (P=0.04). ESE30 incidence was not significantly different between Groups I-III and Group IV. Spline plots demonstrated that experience of 15-20 cases in total was needed to achieve a consistent low risk of ESE30. CONCLUSIONS: Increasing experience was associated with better outcomes, but to a lesser degree than in previous reports. Our findings suggested that the risks associated with the learning curve process were appropriately mitigated.

Japanese registry for Mechanically Assisted Circulatory Support: First report.

BACKGROUND: In Japan, ventricular assist devices (VADs) have been used for patients with severe heart failure as a bridge to transplantation (BTT) since 1992. However, it was not until 1997, when the Organ Transplant Law was enacted, that medical devices received approval by the national health insurance system for that use. To encourage research and development of innovative medical devices, the Pharmaceuticals and Medical Devices Agency has established a public-private partnership in collaboration with academic societies, hospitals and manufacturers. METHODS: The Japanese registry for Mechanically Assisted Circulatory Support (J-MACS) is a prospective registry designed to be harmonized with the Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS). Participation in J-MACS is mandatory for device manufacturers to meet the conditions of approval as well as for hospitals to obtain authorization for reimbursement from the national health insurance system. RESULTS: From June 2010 to April 2015, 476 patients were registered at 31 hospitals. Of these, analysis of primary VAD patients (n = 332) revealed that their overall 360-day survival was 91% (implantable 93%, extracorporeal 84%). CONCLUSIONS: This initial report from J-MACS focuses on patients' demographics, device types, survival, competing outcomes, adverse events and successful examples of system failure detection.

Reporting of Cardiovascular Medical Device Adverse Events to Pharmaceuticals and Medical Devices Agency, Japan.

BACKGROUND: Marketing authorization holders (MAHs) are obligated to report adverse events (AEs) within 15 days (some cases 30 days) to the Pharmaceuticals and Medical Devices Agency (PMDA) of Japan. METHODS: To analyze the timeliness of AE reporting to the PMDA, 6610 reports for five categories of cardiovascular devices were retrieved. Two durations were calculated: (1) time from the date the AE occurred to that when the MAH captured it (DOC: days); and (2) time from the date of MAH capture to that of MAH report (DCR: days). Number of DOC > 15 days (DOC15) and delayed reports (DCR > 15 or 30 days) were also calculated. RESULTS: AEs included 9.2% deaths and 7.5% non-recoveries. DOC15 and delayed reports were 51.0% and 10.9%, respectively. By multivariate analysis, DOC15 was associated with foreign AE, device category, MAH, patient outcome, event category, and AE that had to be reported within 15 or 30 days (AE15/30). Delayed report was associated with device category, MAH, patient outcome, event category, and AE15/30. COMMENTS: Although Japanese MAHs complied with the obligation to report AEs, they often failed to share AEs with healthcare providers. Registry may be a potential solution, although the cooperation of healthcare providers to input data is essential.

Color standardization method and system for whole slide imaging based on spectral sensing.

In the field of whole slide imaging, the imaging device or staining process cause color variations for each slide that affect the result of image analysis made by pathologist. In order to stabilize the analysis, we developed a color standardization method and system as described below. (1) Color standardization method based on RGB imaging and multi spectral sensing, which utilize less band (16 bands) than conventional method (60 bands). (2) High speed spectral sensing module. As a result, we confirmed the following effect. (1) We confirmed the performance improvement of nucleus detection by the color standardization. And we can conduct without training data set which is needed in conventional method. (2) We can get detection performance of H&E component equivalent to conventional method (60 bands). And measurement process is more than 255 times faster.

Administration of the Rho-kinase inhibitor, fasudil, following nitroglycerin additionally dilates the site of coronary spasm in patients with vasospastic angina.

BACKGROUND: The Rho/Rho-kinase signaling pathway is known to be involved in the pathogenesis of coronary artery spasm. Previous studies reported the efficacy of the Rho-kinase inhibitor, fasudil, in the prevention and relief of coronary spasm. The usefulness of fasudil in combination with conventional vasodilating agents, however, has not been fully examined in patients with vasospastic angina. METHODS AND RESULTS: A total of 26 patients (mean age, 61+/-11 years) with documented vasospasm in the left anterior descending coronary artery were examined by the acetylcholine stress test. Coronary diameter at the spasm site was measured at baseline and after the administration of vasodilator agents in the following order: intracoronary nitroglycerin (NTG) (300 microg), intravenous fasudil (30 mg, n=15, fasudil group) or saline (n=11, saline group), and again NTG during coronary angiography. The increase in diameter observed following the first NTG administration was found to be similar in the fasudil and saline groups (38.3+/-23.5% and 42.3+/-17.1%, respectively). The additional change in diameter on fasudil treatment (16.9+/-11.2% increase over the diameter after the first NTG administration) was significantly larger than that with saline (-2.8+/-7.6%, P<0.001). The second administration of NTG did not affect the diameter of the spasm site in either group. CONCLUSIONS: Fasudil further dilated the site of coronary spasm, which had already been treated with NTG in patients with vasospastic angina. These findings support and extend the previous results that showed the feasibility of employing fasudil as a novel therapeutic approach for coronary spasm.

Pacemaker contact dermatitis: The effective use of a polytetrafluoroethylene sheet.

A 52-year-old man with Down's syndrome was implanted with a DDDR pacemaker for advanced atrioventricular block. He was admitted with development of skin eczema and partial exposure of the generator 1 year after reimplantation. There was no evidence of infection on laboratory data. A skin patch test was positive for the metal of the generator (purity 99.9% titanium) after 72 hours. These findings indicated pacemaker contact dermatitis. After the patient was reimplanted with a pacemaker wrapped with a polytetrafluoroethylene sheet, there has been no recurrence of the contact dermatitis during a follow-up period of 3 years.

Vasodilatory effect of subsequent administration of fasudil, a rho-kinase inhibitor, surpasses that of nitroglycerin at the concentric coronary stenosis in patients with stable angina pectoris.

BACKGROUND: Recent studies have suggested that the Rho/Rho-kinase mediated pathway (Rho-kinase pathway) regulates the vasomotion of arteries in pathological conditions. However, it remains unclear regarding whether this pathway regulates the coronary vasomotion of atherosclerotic lesions. METHODS AND RESULTS: The coronary diameter at the concentric stenotic site, which is considered to reflect the whole circumferential atherosclerosis, in patients with stable angina pectoris (SAP; n=11) and the control site in patients with SAP and chest pain syndrome (CPS; n=9), was measured at baseline and after the intracoronary administration of nitroglycerin (200 microg) and the subsequent intravenous infusion of fasudil (30 mg for 30 min), a Rho-kinase inhibitor, during coronary angiography. The change in the diameter with fasudil at the concentric stenotic site (22.0+/-10.0%) was significantly higher than that with nitroglycerin (4.7+/-6.0%, p<0.001) in patients with SAP. Meanwhile, the vasodilatory effect of nitroglycerin and fasudil at the control site was similar in both group of patients (25.5+/-17.3% and 21.9+/-14.9% in SAP and 34.4+/-20.8% and 33.2+/-23.6% in CPS, respectively). CONCLUSIONS: The vasodilatory effect of the subsequent administration of fasudil surpassed that of nitroglycerin at the concentric coronary stenosis in patients with SAP, thus suggesting that the Rho-kinase pathway regulates the coronary vasomotion of atherosclerotic lesions.