Evidence for Cerebral Embolic Prevention in Transcatheter Aortic Valve Implantation and Thoracic Endovascular Aortic Repair.

BACKGROUND: Embolic stroke is a formidable complication of transcatheter aortic valve implantation (TAVI) and thoracic endovascular aortic repair (TEVAR). Mechanical strategies to reduce the risk of ischemic embolic lesions include embolic protection devices (EPDs) and carbon dioxide flushing (CDF). This study aims to assess the efficacy for EPD and CDF uses in TAVI and TEVAR. METHODS: A literature review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis. All searches were performed via PubMed, OvidSP, MEDLINE, Web of Science Core Collection, and Cochrane Library. Conference abstracts and proceedings were included. Those that were out of scope of interest and review articles were excluded. RESULTS: Eighteen studies fulfilled the inclusion criteria of the 456 articles searched. Regarding EPD use in TAVI, systematic review comparing EPD with no-EPD showed smaller total volume of cerebral lesions and smaller volume per lesion in patients with EPD in all studies. They also performed better in postoperative neurocognitive assessments but could not demonstrate clinical prevention of embolic stroke in all studies. While for EPD use in TEVAR, capture of embolic debris and absence of early postoperative neurocognitive deficit were demonstrated in all cases of 2 prospective pilot studies. Concerning CDF in TEVAR, significant reduction in gaseous emboli released during stent-graft deployment was shown by 1 in vitro study. Successful CDF application in all patients, with only 1 case of postoperative nondisabling stroke, was also demonstrated by 1 cohort study. CONCLUSIONS: This systematic review of medical literature has demonstrated the safety and feasibility of EPD use in TAVI. Although improvements in clinical outcomes have yet been demonstrated, there was level I evidence showing reduced embolic lesions in imaging. The use of EPD and CDF in TEVAR was suggested, but evidence remained inadequate to support routine clinical use.

A Cross Sectional Study on Knowledge, Attitude and Practice related to Human Papillomavirus Vaccination for Cervical Cancer Prevention between Medical and Non-Medical Students in Hong Kong

Background: One of the most important aetiologies of cervical cancer is Human Papillomavirus (HPV) infection. While vaccination is an effective way in preventing high risk HPV infection, HPV vaccine uptake rate in Hong Kong has been low. Considering the proven effectiveness of HPV vaccination and the low vaccination uptake rate in Hong Kong, this study was conducted to compare the knowledge, attitude and practice towards HPV vaccination for cervical cancer prevention between medical and non-medical students in the University of Hong Kong. Methods: A total of 420 full time undergraduates from the University of Hong Kong were recruited and evaluated. Questionnaires covering demographics, sexual risk profile, knowledge, attitude and practice towards HPV vaccination were applied, with the Chi-square test analysis. Results: Medical students had more comprehensive knowledge than their non-medical counterparts on HPV vaccination, including the carcinogenicity of HPV (P<0.001), available vaccines on the market (P<0.001) and the outcome of vaccination (P<0.001). In particular, senior medical students (Year 3 or above) were shown to be more knowledgeable than their juniors (below Year 3) with statistical significance (P<0.001). Positive attitudes toward HPV vaccination were observed more frequently among medical students when compared to non-medical students, especially regarding the usefulness of HPV vaccination in males (P<0.001). However, there was no significant difference in the vaccination rate between medical and non-medical students (P=0.671), suggesting an importance for factors other than knowledge, such as cost of vaccination and anxiety of side effects. Conclusions: Medical students in Hong Kong, especially those in senior years, had more comprehensive knowledge and positive attitudes towards HPV vaccination than non-medical students. Yet, there was no significant difference in the practice of HPV vaccination between medical and non-medical students. In addition to medical education, other factors such as health beliefs, risk perception and financial considerations, may have a role in determining HPV vaccination for cervical cancer prevention.