A System for Accurate Deployment of Unconstrained Triple-Fenestrated Aortic Arch Endografts

Purpose: To achieve accurate rotational orientation and the axial position of unconstrained triple-fenestrated physician-modified endografts upon deployment in the aortic arch during total arch thoracic endovascular aortic repair (TA-TEVAR). Materials and Methods: Following a detailed study of reconstructed computerized tomography angiography images of patients’ arch anatomy, customized, sealable fenestrations with radio-opaque margins are created onsite on Valiant Captivia (Medtronic) endografts, transposing the arch branch ostial anatomic interrelationship onto the endograft precisely. Radio-opaque figure-of-8 markers, indicating the 12 o’clock (superior) position, are attached to the endograft on the surface and brought up to the surface under the endograft cover during resheathing. Resheathing without any twist in the endograft is achieved by lining up the welds in each endograft stent segment in a straight line. The fluoroscopic working view for arch endograft delivery and deployment is the left anterior oblique view that is orthogonal to the plane of the arch, which, in turn, is the right anterior oblique view in which parts of a stiff indwelling guidewire in the ascending and descending aorta precisely overlap. During introduction in the working view, the endograft delivery system is rotated in the descending thoracic aorta so that the 12 o’clock figure-of-8 markers are viewed on the edge and situated at the outer aortic curvature; continued advancement into the arch without any further rotation will ensure superior orientation of the figure-of-8 markers and, consequently, correct endograft rotational orientation. Proper axial endograft positioning requires locating the left common carotid artery (LCCA) fenestration just proximal to a taut externalized LCCA-femoral guidewire loop marking the posterior limit of the LCCA ostium. After endograft deployment during rapid cardiac pacing, the target arch branches are cannulated through their respective fenestrations using hydrophilic 0.035-inch guidewires that are externalized via distal sheaths to create femoral-arch branch (through-and-through) loops over which covered fenestrated stents are introduced and deployed. Results: This technique was used successfully in 31 consecutive patients undergoing TA-TEVAR; systemic blood pressure was obtained in all arch branches immediately after endograft deployment, indicating adequate blood flow. All arch branches were successfully cannulated and stented. Conclusion: This system enables accurate deployment of unconstrained triple-fenestrated arch endografts simply and reliably during TA-TEVAR.

Accuracy of registration techniques and vascular imaging modalities in fusion imaging for aortic endovascular interventions: a phantom study

Background This study aimed to assess the error of different registration techniques and imaging modalities for fusion imaging of the aorta in a standardized setting using a anthropomorphic body phantom. Materials and methods A phantom with the 3D printed vasculature of a patient suffering from an infrarenal aortic aneurysm was constructed. Pulsatile flow was generated via an external pump. CTA/MRA of the phantom was performed, and a virtual 3D vascular model was computed. Subsequently, fusion imaging was performed employing 3D-3D and 2D-3D registration techniques. Accuracy of the registration was evaluated from 7 right/left anterior oblique c-arm angulations using the agreement of centerlines and landmarks between the phantom vessels and the virtual 3D virtual vascular model. Differences between imaging modalities were assessed in a head-to-head comparison based on centerline deviation. Statistics included the comparison of means ± standard deviations, student’s t-test, Bland-Altman analysis, and intraclass correlation coefficient for intra- and inter-reader analysis. Results 3D-3D registration was superior to 2D-3D registration, with the highest mean centerline deviation being 1.67 ± 0.24 mm compared to 4.47 ± 0.92 mm. The highest absolute deviation was 3.25 mm for 3D-3D and 6.25 mm for 2D-3D registration. Differences for all angulations between registration techniques reached statistical significance. A decrease in registration accuracy was observed for c-arm angulations beyond 30° right anterior oblique/left anterior oblique. All landmarks (100%) were correctly positioned using 3D-3D registration compared to 81% using 2D-3D registration. Differences in accuracy between CT and MRI were acceptably small. Intra- and inter-reader reliability was excellent. Conclusion In the realm of registration techniques, the 3D-3D method proved more accurate than did the 2D-3D method. Based on our data, the use of 2D-3D registration for interventions with high registration quality requirements (e.g., fenestrated aortic repair procedures) cannot be fully recommended. Regarding imaging modalities, CTA and MRA can be used equivalently.

Detection of Coronary Artery Anomaly in Tetralogy of Fallot: Comparison of Two Angiographic Views

Background: The definite treatment of tetralogy of Fallot (TOF) as the most common cyanotic congenital heart disease is open heart surgery and the operation technique depends on the coronary artery anatomy. Objectives: We aimed to evaluate the sensitivity and specificity of various root Aortogram views to detect abnormal coronary artery configuration and course in these patients. Methods: In this retrospective study, the reports of coronary anatomy in angiography and operation notes of TOF patients since 2005 to 2018 were evaluated. The sensitivity and specificity of the two common root Aortogram views including the left anterior oblique/cranial (LAO/CRA) and left anterior oblique/caudal (LAO/CAU) were determined. Results: Four hundred and fifty one patients with the median age of 28 months (3 - 432 months) were included. All patients had LAO/CRA views and 199 patients had both LAO/CRA and LAO/CAU views. The rate of coronary abnormalities reported by surgery was 8%, and abnormal origin of the left anterior descending artery from the right coronary artery was the most common reported anomaly (4.4%). The sensitivity of the LAO/CAU view was 100%, but LAO/CRA view was about 75% in detecting abnormal coronary configuration. Both of them had excellent specificity (~100%). No significant sex difference was seen between different coronary anatomy abnormalities. Conclusions: The Caudal root angiogram is an essential view to evaluate coronary artery anatomy in TOF patients and it seems that there is no need for other views like lateral view, but relying on LAO/CRA view alone may lead to significant misdiagnosis of the coronary arteries, crossing the right ventricular outflow tract (RVOT).

SCATTER RADIATION IN THE FLUOROSCOPY-GUIDED INTERVENTIONAL ROOM

Radiation scattered throughout the room during fluoroscopy-guided interventional (FGI) procedures was quantified at different locations using nanoDot optically stimulated luminescence dosemeters. All the tube angulation imaging shows that the radiation spectrum resembled a single peak distribution. The left anterior oblique 90° shows the highest single peak distribution (28.65 mSv/h). The single peak distribution for standard anteroposterior, left anterior oblique 45° and right anterior oblique 45° imaging was 13.32, 22.99 and 17.40 mSv/h, respectively. All tube angulation shows that the position of the interventional radiologist experienced a higher radiation level compared to other staffs. The doses of radiation varied widely around the perimeter of the patient’s table and changed in accordance to imaging angles during procedures. Knowledge pertaining to radiation exposure levels is integral in order to avoid adverse risks, particularly among staff.

Preemptive angioplasty for contralateral leg stenosis following EXCLUDER Iliac Branch Endoprosthesis implantation

The GORE EXCLUDER Iliac Branch Endoprosthesis (IBE) device is designed to seal off a common iliac artery (CIA) aneurysm, preserving the internal iliac artery during endovascular aortic repair. We report the case of an 84-year-old man with isolated saccular right CIA aneurysm (35 mm) and a relatively small terminal aorta (24 mm). The IBE device was successfully placed, and intraoperative angiography revealed no leakage or delay. However, postoperative computed tomography revealed marked compression of the contralateral leg by a bridging component. Although his ankle–brachial index was preserved, its acute occlusion was judged highly possible; we decided to perform preemptive angioplasty. The angiography revealed the stenosis only in the left anterior oblique view, and angioplasty was uneventfully performed. The leg was successfully patent at 1-year follow-up. When compression by IBE and bridging component in the terminal aorta is expected, caution should be preserved at intraoperative angiography following the device deployment.

What is the best angiographic view for detection of coronary artery abnormality in Tetralogy of Fallot? A retrospective study

Background The definite treatment of tetralogy of Fallot (TOF) as the most common cyanotic congenital heart disease is open heart surgery and the operation technique depends on the coronary artery anatomy. We aimed to evaluate the sensitivity and specificity of various root Aortogram views to detect abnormal coronary artery configuration and course in these patients.Methods In this retrospective study, the reports of coronary anatomy in angiography and operation notes of TOF patients since 2005 to 2017 were evaluated. The sensitivity and specificity of the two common root Aortogram views including the left anterior oblique/cranial (LAO/CRA) and left anterior oblique/caudal (LAO/CAU) were determined.Results 451 patients with the median age of 28 months (3-432 months) were included. All patients had LAO/CRA views and 199 patients had both LAO/CRA and LAO/CAU views. The rate of coronary abnormalities reported by surgery was 8%, and abnormal origin of the left anterior descending artery from the right coronary artery was the most common reported anomaly (4.4%). The sensitivity of the LAO/CAU view was 100%, but LAO/CRA view was about 75% in detecting abnormal coronary configuration. Both of them had excellent specificity (~100%). No significant sex difference was seen between different coronary anatomy abnormalities.Conclusion The Caudal root angiogram is an essential view to evaluate coronary artery anatomy in TOF patients and it seems that there is no need for other views like lateral view, but relying on LAO/CRA view alone may lead to significant misdiagnosis of the coronary arteries, crossing the right ventricular outflow tract (RVOT).