Does biplane imaging reduce contrast load, procedural and screening time compared to single-plane imaging in routine diagnostic coronary angiography?

An Electromagnetically Controllable Microrobotic Interventional System for Targeted, Real-Time Cardiovascular Intervention

Robotic magnetic manipulation systems offer a wide range of potential benefits in medical fields, such as precise and selective manipulation of magnetically responsive instruments in difficult-to-reach vessels and tissues. However, more preclinical/clinical studies are necessary before robotic magnetic interventional systems can be widely adopted. In this study, a clinically translatable, electromagnetically controllable microrobotic interventional system (ECMIS) that assists a physician in remotely manipulating and controlling microdiameter guidewires in real time, is reported. The ECMIS comprises a microrobotic guidewire capable of active magnetic steering under low-strength magnetic fields, a human-scale electromagnetic actuation (EMA) system, a biplane X-ray imaging system, and a remote guidewire/catheter advancer unit. The proposed ECMIS demonstrates targeted real-time cardiovascular interventions in vascular phantoms through precise and rapid control of the microrobotic guidewire under EMA. Further, the potential clinical effectiveness of the ECMIS for real-time cardiovascular interventions is investigated through preclinical studies in coronary, iliac, and renal arteries of swine models in vivo, where the magnetic steering of the microrobotic guidewire and control of other ECMIS modules are teleoperated by operators in a separate control booth with X-ray shielding. The proposed ECMIS can help medical physicians optimally manipulate interventional devices such as guidewires under minimal radiation exposure.

Factors contributing to radiation dose for patients and operators during diagnostic cardiac angiography

INTRODUCTION

Diagnostic coronary angiography (CA) uses ionising radiation with relatively high doses, which impact on both patients and staff. This study sought to identify which patient and procedural factors impact patient and operator dose the most during CA.

METHODS

Patient and procedure related variables impacting on Kerma area product (PKA ) and operator dose (OD) were collected for 16 months. Procedures were separated into 10 different procedure categories. PKA was used for patient dose and OD was measured with an instantly downloadable dosimeter (IDD) - downloaded at the end of each procedure. High and low radiation dose was defined by binary variables based on the 75th percentile of the continuous measures. Univariate and multivariate regression were used to identify predictors.

RESULTS

Of 3860 patients included, the IDD was worn for 2591 (61.7%). Obesity (BMI > 30 compared to BMI < 25) was the strongest predictor for both a PKA (odds ratio (OR) = 19.1 (95% CI 13.5-26.9) P < 0.001) and OD (OR = 3.3 (2.4-4.4) P < 0.001) above the 75th percentile. Male gender, biplane imaging, the X-ray unit used, operator experience and procedure type also predicted a high PKA . Radial access, male gender, biplane imaging and procedure type also predicted a high OD.

CONCLUSION

Radiation dose during CA is multifactorial and is dependent on patient and procedure related variables. Many factors impact on both PKA and OD but obesity is the strongest predictor for both patients and operators to receive a high radiation dose.

Impact of single-plane versus Bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion percutaneous coronary intervention

OBJECTIVE

The aim of the study is to evaluate the impact of single-plane and bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

Between January 2008 and December 2015, a total of 359 patients received scheduled retrograde CTO PCI and were enrolled in the study; 119 patients underwent PCI by single-plane imaging, and another 240 patients underwent PCI by bi-plane imaging.

RESULTS

A 95.0% rate of technical success was noted in the single-plane imaging group, and a 95.8% rate of technical success was noted in the bi-plane imaging group. All patients received the CTO approach via the retrograde method, and the retrograde method success rate was 88.2% in single-plane imaging group, and 81.7% in the bi-plane imaging group. A longer procedural time (153.73 ± 53.15 vs 172.88 ± 61.30 min; P = 0.004), longer fluorescence time (71.40 ± 25.96 vs 80.95 ± 34.70 min; P = 0.008), and more contrast medium volume (342.77 ± 102.25 vs 394.58 ± 156.41 mL; P = 0.001) were noted in the bi-plane imaging group. After propensity score match, a longer procedural time, longer fluorescence time, and more contrast volume was noted in bi-plane group.

CONCLUSION

Bi-plane imaging could not decrease procedural time, fluorescence time, and contrast medium volume in retrograde CTO PCI.

Optimisation of coronary angiography exposures requires a multifactorial approach and careful procedural definition

OBJECTIVE

This study investigates the factors associated with higher doses for both single-plane and biplane procedures and establishes centre-specific 75th percentile levels.

METHODS

602 patients undergoing coronary angiography in a large hospital at Sydney were recruited to the study, and causal agents for high radiation doses were investigated: gender, procedural complexity, severity of coronary artery disease, presence of coronary bypass grafts, entry approach (radial or femoral), level of operator experience; and a single-plane or a biplane imaging system was employed.

RESULTS

The 75th percentile levels were calculated. The results demonstrated that, for both systems, higher exposures were associated with patients who were male (p<0.001), had coronary vessel disease (p<0.001) and had a history of coronary bypass grafts (p<0.001). In addition, for biplane systems, procedural complexity (p<0.001), types of entry approach (p<0.001) and levels of operator experience (p<0.001) significantly impacted upon the dose. Biplane examinations recorded higher doses than single-plane procedures (p<0.001) and the inclusion of left-sided ventriculography contributed to the overall dose by up to 10%.

CONCLUSION

The 75th percentile levels in this study represent the tentative reference levels and are 48.9, 44.2 and 56 Gy cm(2) for all exposures, single-plane- and biplane-specific exposures, respectively, and compare favourably with the diagnostic reference level values established elsewhere internationally, with only the UK and Irish data being lower.

ADVANCES IN KNOWLEDGE

Specific agents have been identified for dose-reducing strategies and the importance of operator training is highlighted. The assumption that biplane procedures may reduce the patient dose should be treated with caution.

Impact of biplane versus single-plane imaging on radiation dose, contrast load and procedural time in coronary angioplasty

Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose-area-product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4+/-121.0 Gycm(2)) than single-plane imaging (133.6+/-92.8 Gycm(2), p<0.0001). The difference was independent of case type (primary or elective) (p = 0.862), vascular territory (p = 0.519) and operator experience (p = 0.903). No significant difference was found in contrast load between biplane (166.8+/-62.9 ml) and single-plane imaging (176.8+/-66.0 ml) (p = 0.302). This non-significant difference was independent of case type (p = 0.551), vascular territory (p = 0.308) and operator experience (p = 0.304). Procedures performed with biplane imaging were significantly longer (55.3+/-27.8 min) than those with single-plane (48.9+/-24.2 min, p = 0.010) and, similarly, were not dependent on case type (p = 0.226), vascular territory (p = 0.642) or operator experience (p = 0.094). Biplane imaging resulted in a greater radiation dose and a longer procedural time and delivered a non-significant reduction in contrast load than single-plane imaging. These findings did not support the commonly perceived advantages of using biplane imaging in single-vessel coronary interventional procedures.