Efficacy of a Protective Sheet for Reducing Ocular Radiation Exposure During Transcatheter Aortic Valve Implantation.

BACKGROUND: The use of hybrid operating rooms (HOR) for transcatheter aortic valve implantation (TAVI) has increased, so radiation exposure during procedures that use X-ray fluoroscopy is a fundamental problem not only for patients but also for surgeons and interventional cardiologists, increasing the risk of cataracts among operators. We investigated the efficacy of leaded glasses and protective sheets for ocular radiation protection.Methods and Results: Between January 2020 and February 2021 we enrolled 54 TAVI procedures using the transfemoral approach. The subjects were divided into a curtain protection group (Group C, n=20), glass protection group (Group G, n=17), and sheet protection group (Group S, n=17). The cumulative dose (CD) of the operators showed a decreasing trend in Group S compared with the other two groups. The CD normalized by dose area product (CD/DAP) of the operators was significantly reduced in Group S compared with Group C. However, Group G showed no significant difference compared with Group C. Regarding the distribution of CD/DAP, Group S had a significantly lower distribution than that in groups C and G. CONCLUSIONS: Protective sheets provide more stable radiation protection than conventional curtains or leaded glasses.

Effect of Host Structure on Optical Freedericksz Transition in Dye-Doped Liquid Crystals.

The optical Freedericksz transition (OFT) can reversibly control the molecular orientation of liquid crystals (LCs) only by light irradiation, leading to the development of all-optical devices, such as smart windows. In particular, oligothiophene-doped LCs show the highly sensitive OFT due to the interaction between dyes and an optical-electric field. However, the sensitivity is still low for the application to optical devices. It is necessary to understand the factors in LCs affecting the OFT behavior to reduce the sensitivity. In this study, we investigated the effect of the host LC structure on the OFT in oligothiophene-doped LCs. The threshold light intensity for the OFT in trifluorinated LCs was 42% lower than that in LCs without fluorine substituents. This result contributes to the material design for the low-threshold optical devices utilizing the OFT of dye-doped LCs.

Impact of radiation to the eye of operators during endo-cardiovascular surgery and the importance of protection.

OBJECTIVE: To verify the amount of radiation exposure to the eye of operators during endocardiovascular surgery (ECVS) in hybrid operating room (HOR), which increases the risk of cataracts in surgeons. METHODS: Fifty cases of ECVS (including 36 transcatheter aortic valve implantation and 14 thoracic endovascular repair) using the transfemoral approach performed from February 2020 to July 2020 were included. A measurement device was attached to the left side of the head of the operators and their assistants to measure the cumulative dose (CD) of intraoperative radiation exposure. The subjects were divided into the control group (Group C, n = 26), received conventional protection using the protective curtain in HOR and the protected group (Group R, n = 24), received conventional protection and protection sheet. The normalized CD by dose area product (CD/DAP) was evaluated. RESULTS: The CD/DAP of the surgeons was significantly decreased in Group R, averaging at 5.97 µSV/Gy cm2 in Group C group and 4.40 µSV/Gy cm2 in Group R (p < 0.01). Moreover, CD/DAP of the assistant was significantly reduced in the Group R, with an average of 1.87 µSV/Gy cm2 in the Group C and 1.01 µSV/Gy cm2 in Group R (p < 0.01). CONCLUSIONS: The radiation exposure to the surgeon's eye could be significantly reduced by protection sheet.

Successful treatment of graft-duodenal fistula after renovisceral debranching thoracic endovascular aortic repair with limited graft resection based on 18F-fluorodeoxyglucose positron emission tomography with computed tomography.

We present the case of a patient with a graft-duodenal fistula after renovisceral debranching thoracic endovascular aortic repair. 18F-fluorodeoxyglucose positron emission tomography with computed tomography showed that the infection was localized to the renovisceral bypass grafts and the right kidney. Based on the preoperative imaging findings, a limited surgery with resection was performed in the fistula, right kidney, and fluorodeoxyglucose-positive bypass grafts, while preserving the fluorodeoxyglucose-negative grafts. No signs of reinfection were reported 2 years after the surgery. Accurate assessment of infection with 18F-fluorodeoxyglucose positron emission tomography with computed tomography may be useful for performing adequate excision of infected lesions.

Atrial fibrillation following aortic valve replacement: impact of perioperative use of intravenous ß-blocker.

OBJECTIVES: Despite recent advances in perioperative management, postoperative atrial fibrillation/flutter (POAF) remains the most common complication after cardiac surgery. Therefore, it is important to determine related risk factors to establish effective management. However, most studies have focused on patients undergoing coronary artery bypass grafting and little is known about POAF in those who receive aortic valve replacement (AVR). We investigated the relationship of clinical predictors with POAF in patients undergoing AVR. METHODS: A total of 119 patients who underwent AVR were enrolled in this study, and the relationships between POAF incidence and perioperative (preoperative, operative, postoperative) factors were examined. RESULTS: POAF occurred in 47 patients (40%). In univariate analysis, older age was significantly associated with POAF occurrence, which was significantly related to prolonged intensive care unit (ICU) stay and postoperative stroke. It also showed patients with preoperative ß-blocker experienced POAF less frequently than those without ß-blocker. Multivariate analysis showed that preoperative ß-blocker usage was an independent predictor of POAF. In patients who received both preoperative oral and postoperative intravenous ß-blocker administrations, the incidence of POAF was reduced to 14% (3/22). CONCLUSIONS: POAF frequently occurred in patients undergoing AVR, and was significantly related to prolonged ICU stay and postoperative stroke. Our findings show that advanced age and absence of preoperative ß-blocker usage are risk factors for POAF. Furthermore, in patients undergoing AVR, perioperative intravenous ß-blocker administration may be useful for prevention.