R. Zayat

The flutter-by effect: a comprehensive study of the fluttering cusps of the Perceval heart valve prosthesis

OBJECTIVES Sutureless aortic valve prostheses are gaining popularity due to the substantial reduction in cross-clamp time. In this study, we report our observations on the cusp-fluttering phenomenon of the Perceval bioprosthesis (LivaNova, London, UK) using a combination of technical and medical perspectives. METHODS Between August 2014 and December 2016, a total of 108 patients (69% women) with a mean age of 78 years had aortic valve replacement using the Perceval bioprosthesis (34 combined procedures). All patients underwent transoesophageal echocardiography (TOE) intraoperatively. TOE was performed postoperatively to detect paravalvular leakage and to measure gradients, acceleration time, Doppler velocity indices (Vmax and LVOT/Vmax AV) and effective orifice area indices. In addition, a TOE examination was performed in 21 patients postoperatively. Data were collected retrospectively from our hospital database. RESULTS The retrospective evaluation of the intraoperative TOE examinations revealed consistent fluttering in all patients with the Perceval bioprosthesis. The echocardiographic postoperative measurements showed a mean effective orifice area index of 0.91 ± 0.12 cm2/m2. The overall mean pressure and peak pressure gradients were in a higher range (13.5 ± 5.1 mmHg and 25.5 ± 8.6 mmHg, respectively), whereas acceleration time (62.8 ± 16.4 ms) and Doppler velocity indices (0.43 ± 0.11) were within the normal range according to the American Society of Echocardiography or european association of echocardiography (EAE) guidelines. The 2-dimensional TOE in Motion Mode (M-Mode) that was performed in patients with elevated lactate dehydrogenase (LDH) levels revealed remarkable fluttering of the cusps of the Perceval bioprosthesis. CONCLUSIONS In our study cohort, we observed the fluttering phenomenon in all patients who received the Perceval bioprosthesis, which was correlated with elevated LDH levels and higher pressure gradients.

Cross-contamination between Tracheostomy and Sternotomy Following Percutaneous Dilation Tracheostomy and Its Influence on Sternal Wound Infections in Cardiac Surgery

Background: The impact of percutaneous dilation tracheostomy (PDT) on development of post-median sternotomy wound infection (SWI) is still debated. In a retrospective study, we aimed to investigate the frequency of cross-contamination and whether PDT changes the microbial spectrum in SWI. Methods: In this study, between January 2010 and May 2013, all patients with post-median sternotomy PDT were included (group A and B). Our control group C comprised patients with SWI without postoperative PDT. Pre-, peri-, and postoperative parameters, day and duration of the PDT, duration of mechanical ventilation and microbiological data from tracheal secretion, sternal wound, blood cultures, and clinical outcomes were collected. Results: From 265 patients who received PDT, 25 (9.43%) developed SWI after PDT (group A). In eight (32%) patients from group A, identical pathogens were isolated from the tracheostomy and sternal wound. The majority of patients with cross-contamination had polymicrobial infections. The common pathogens isolated from both sites were: 77% tracheal pathogens (Coagulase-negative staphylococci (n = 2), Candida spp. (n = 5), Klebsiella spp. (n = 3)) and 23% gram-negative bacteria (n = 3). In group A versus C, there was significantly more mediastinitis (28% (7/25) versus 12.2% (16/131), p = 0.0001). Seven (87.5%) patients with cross-contamination had CDC II-III infection. In our control group (C) of SWI without postoperative PDT, 73.2% gram positive species and only 1.5% (2/131; p = 0.0012) Candida spp. were detected. The overall mortality was high in group A versus C (48% (n = 12) versus 3.82% (n = 5), p = 0.0001). Mortality within the first 30 postoperative days was 12% (n = 3) versus 0 (p = 0.003). One patient who died in the first 30 POD had cross-contamination. Pearson-test did not demonstrate a correlation between the day of PDT and the development of SWI. Conclusion: Although risk of microbial cross-contamination from PDT to the sternal wound is high (32%) due to neighboring anatomical structures, its clinical relevance remains uncertain. Coincidence of PDT and SWI remains low. In our study, we could detect changes in the microbial spectrum: the incidence of candida spp. was significantly higher (20% versus 1.5% p = 0.0012) in patients with SWI after PDT than in SWI without PDT. At the same time, the incidence of S. aureus (8% versus 29% p = 0.026) was significantly lower. Large multicenter studies would be needed to further clarify the described interferences.