Background. The MAVIG X-ray protective drape (MXPD) has been shown to reduce operator radiation dose during percutaneous coronary interventions (PCI). Whether MXPDs are also effective in reducing operator radiation during chronic total occlusion (CTO) PCI, often with dual access, is unknown. Methods. We performed a prospective, randomized-controlled study comparing operator radiation dose during CTO PCI (n = 60) with or without pelvic MXPDs. The primary outcomes were the difference in first operator radiation dose (μSv) and relative dose of the first operator (radiation dose normalized for dose area product) at the level of the chest in the two groups. The effectiveness of MXPD in CTO PCI was compared with non-CTO PCI using a patient-level pooled analysis with a previously published non-CTO PCI randomized study. Results. The use of the MXPD was associated with a 37% reduction in operator dose (weighted median dose 26.0 (IQR 10.00–29.47) μSv in the drape group versus 41.8 (IQR 30.82–60.59) μSv in the no drape group; P < 0.001) and a 60% reduction in relative operator dose (median dose 3.5 (IQR 2.5–5.4) E/DAPx10−3 in the drape group versus 8.6 (IQR 4.2–12.5) E/DAPx10−3 in the no drape group; P = 0.001). MXPD was equally effective in reducing operator dose in CTO PCI compared with non-CTO PCI (P value for interaction 0.963). Conclusions. The pelvic MAVIG X-ray protective drape significantly reduced CTO operator radiation dose. This trial is clinically registered with https://
The main source of operator radiation during percutaneous coronary interventions (PCI) is scatter from the patient. Reduction of this radiation is especially important in chronic total occlusion (CTO) PCI since these procedures are lengthy and are mostly carried out by dedicated operators. While CTO operator radiation can be reduced by adjustment of catheterization suite settings, there is potential for further improvement [[
Consecutive CTO procedures were included from October 2019 until November 2020 as part of a single-center, investigator-initiated RCT (ClinicalTrials.gov Identifier NCT04285944). During study design, it was anticipated that inclusion of CTO procedures would take much longer than inclusion for routine cardiac catheterization procedures. Therefore, a separate parallel study, with separate randomization and separate dosimeters, was planned. All drapes had already been purchased by the University Hospitals Leuven, and no funding was obtained from MAVIG (Munich, Germany). The study protocol was approved by the local ethical committee (study identifier S62469). Details of the methods, the cardiac catheterization facility, radiation measurements, and statistical analysis have been published previously [[
The MXPDs have been designed to protect against scatter radiation from the patient's body during both femoral and radial access procedures. The femoral drape (ST-FS5AMM) weighs 1.31 kg and measures 75 × 36 cm. The radial drape (ST-RZ5AMM) weighs 1.56 kg and measures 75 × 40 cm. These drapes have a lead equivalence of 0.5 mm. The MXPDs were inserted into a sterile sleeve and positioned over the pelvic area of the patient with the larger portion of the MXPD placed towards the operator.
We used a computer-based 1 : 1 randomization, which took place prior to the start of the cardiac catheterization procedure. Depending on the result, the first and second operators (who stood in the first operator and second operator positions on the right of the table, near the pelvis of the patient) wore the dosimeters for the MXPD arm or the dosimeters for the control arm. Study dosimeters were shared by CTO operators and analysed after ten procedures in order to increase the accuracy of the operator radiation dose measurement. For every procedure, the operators wore chest dosimeters (Inlight, Landauer, USA) on the outside of the left apron pocket. Dosimeters were calibrated according to ISO norms N60 reference beam against personal dose equivalent Hp(
The primary endpoints were the difference in operator radiation dose between the drape and no drape groups, and the difference in operator radiation dose indexed for the patient radiation dose as estimated by the dose area product (E/DAP). CTO operator dose was a summation of first and second operator radiation dosimeters, since the operators switched position in 27% of cases.
Continuous variables are expressed as mean ± standard deviation (SD) or median and interquartile range (IQR, 25
Sixty consecutive CTO procedures were included between October 2019 and November 2020. Baseline characteristics, CTO complexity (Table 1), fluoroscopy time, air kerma (K
Table 1 Patient, theatre, and procedural details.
All ( No drape ( Drape ( Patient details Age (mean ± SD) 66 ± 11 68 ± 10 64 ± 12 Male 43 (72) 20 (67) 23 (77) Weight (kg) 78.9 ± 15.5 80.6 ± 15.6 77.2 ± 15.8 Height (m) 1.7 ± 0.1 1.7 ± 0.1 1.7 ± 0.1 Body mass index (kg/m2) 24 ± 9.7 23.5 ± 11.6 24.3 ± 7.7 Diabetes 12 (20) 8 (27) 4 (13) Hyperlipidemia 50 (83) 28 (93) 22 (73) Hypertension 42 (70) 19 (63) 23 (77) Prior PCI 29 (48) 16 (53) 13 (43) Prior CABG 8 (13) 5 (17) 3 (10) Procedure details Second operator took over 16 (27) 9 (30) 7 (23) Radial Access 50 (83) 25 (83) 25 (83) Femoral access 46 (77) 23 (77) 23 (77) Bilateral injections 53 (88) 26 (87) 27 (90) 7F access 59 (98) 29 (97) 30 (100) CTO details Left anterior descending artery 14 (23) 8 (27) 6 (20) Right coronary artery 35 (58) 18 (60) 17 (57) Circumflex artery 11 (18) 4 (13) 7 (23) Complications 0 (0) 0 (0) 0 (0) J-CTO score 2.1 ± 1.2 2.23 ± 1.3 1.9 ± 1.2
1 Values are number (%) or mean ± SD. SD, standard deviation; PCI, percutaneous coronary intervention; CABG, coronary artery bypass grafts.
Graph: Figure 1 Median and interquartile ranges for procedure time (defined as the time from sheath-in to catheter-out), fluoroscopy time, air kerma, and dose area product (DAP) in all procedures and in the two groups. Bars represent median values with interquartile range.
Graph: Figure 2 Median operator chest dose and relative operator chest dose normalized for dose area product (x10−3). Bars represent median values with interquartile range.
In this prospective randomized trial, we report that CTO operator radiation is reduced by 37% with the MAVIG X-ray protective drape (MXPD), and when DAP is taken into consideration, the effective dose for the CTO operator is reduced by 60%. These findings are in line with a previously published study with MXPD, which demonstrated a 57% reduction in relative operator radiation dose during routine cardiac catheterization and PCI [[
Several studies have demonstrated that operator radiation can be significantly reduced when using a lead or lead-equivalent drape over the pelvis of the patient [[
The MXPD can be used under the sterile sheets of the patient or can be placed in a commercially available sterile plastic sleeve. This means that the MXPDs are reusable with a significant cost reduction in the long-term compared with RADPAD. The advantage of the sleeve system is that the position of the drape can easily be adjusted to ensure that it does not come into the field of view. However, in obese patients, it has a tendency of sliding out of position.
The study has some limitations, which have been discussed previously [[
This is the first CTO-dedicated randomized-controlled trial measuring operator radiation dose reduction with and without a pelvic radiation protection device. The pelvic MAVIG X-ray protective drapes reduced the effective CTO operator radiation dose by more than half.
• CTO:
- Chronic total occlusion
• DAP:
- Dose area product
• Gy:
• Gray
• J-CTO:
- Japan chronic total occlusion
-
K
a,r : - Air kerma
• MXPD:
- MAVIG X-ray protective drapes
• PCI:
- Percutaneous coronary intervention
• RCT:
- Randomized-controlled trial.
The data used to support the findings of this study were collected from the University Hospitals Leuven Cardiac Catheterization Laboratory and are made available from the corresponding author upon request.
The authors declare that they have no conflicts of interest.
The authors would like to thank Mrs. Sabine Van Roey for help with study logistics. A part of this study received funding from the Euratom Research and Training Programme 2014–2018 (755523).
By Keir McCutcheon; Maarten Vanhaverbeke; Jérémie Dabin; Ruben Pauwels; Werner Schoonjans; Walter Desmet and Johan Bennett
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