OBJECTIVES Current guidelines recommend prophylactic replacement of the ascending aorta at an aneurysmal diameter of >55 mm to prevent acute Type A aortic dissection (TAAD) in non-Marfan patients. Several publications have challenged this threshold, suggesting that surgery should be performed in smaller aneurysms to prevent this devastating disease. We reviewed our experience with measuring aortic size at the time of TAAD to validate the existing recommendation for prophylactic ascending aorta replacement. METHODS All patients who had been admitted for TAAD to our emergency department from 2014 to 2019 and underwent ascending aorta replacement were included. Marfan patients were excluded. The maximum diameter of the dissected aorta was measured preoperatively using CT scan. We estimated the aortic diameter at the time of dissection to be 7 mm smaller than the measured maximum diameter of the dissected aorta (modelled pre-dissection diameter). RESULTS Overall, 102 patients were included. Of these, 67 were male (65.6%) and 35 were female (34.4%), and the cohort’s mean age was 65 ± 12.1 years. In addition, 66% were treated for arterial hypertension. The mean maximum modelled pre-dissection diameter was 39.6 ± 4.8 mm: 39.1 ± 5.1 mm in men and 40.7 ± 2.8 mm in women (P = 0.1). The cumulative 30-day mortality rate was 19.6% (20/102). CONCLUSIONS TAAD occurred at a modelled aortic diameter below 45 mm in 87.7% of our patients. Therefore, the current aortic diameter threshold of 55 mm excludes ∼99% of patients with TAAD from prophylactic replacement of the ascending aorta. The maximum diameter of the ascending aorta warrants reappraisal and this parameter should be a distinct part of a personalized decision-making process that also takes into account age, gender and body surface area to establish the surgical indication for preventive aorta replacement aimed to improve the survival benefit of this procedure.
Objectives To quantitatively evaluate the impact of virtual monochromatic images (VMI) on reduced-iodine-dose dual-energy coronary computed tomography angiography (CCTA) in terms of coronary lumen segmentation in vitro, and secondly to assess the image quality in vivo, compared with conventional CT obtained with regular iodine dose. Materials and methods A phantom simulating regular and reduced iodine injection was used to determine the accuracy and precision of lumen area segmentation for various VMI energy levels. We retrospectively included 203 patients from December 2017 to August 2018 (mean age, 51.7 ± 16.8 years) who underwent CCTA using either standard (group A, n = 103) or reduced (group B, n = 100) iodine doses. Conventional images (group A) were qualitatively and quantitatively compared with 55-keV VMI (group B). We recorded the location of venous catheters. Results In vitro, VMI outperformed conventional CT, with a segmentation accuracy of 0.998 vs. 1.684 mm2, respectively (p < 0.001), and a precision of 0.982 vs. 1.229 mm2, respectively (p < 0.001), in simulated overweight adult subjects. In vivo, the rate of diagnostic CCTA in groups A and B was 88.4% (n = 91/103) vs. 89% (n = 89/100), respectively, and noninferiority of protocol B was inferred. Contrast-to-noise ratios (CNR) of lumen versus fat and muscle were higher in group B (p < 0.001) and comparable for lumen versus calcium (p = 0.423). Venous catheters were more often placed on the forearm or hand in group B (p < 0.001). Conclusion In vitro, low-keV VMI improve vessel area segmentation. In vivo, low-keV VMI allows for a 40% iodine dose and injection rate reduction while maintaining diagnostic image quality and improves the CNR between lumen versus fat and muscle. Key Points • Dual-energy coronary CT angiography is becoming increasingly available and might help improve patient management. • Compared with regular-iodine-dose coronary CT angiography, reduced-iodine-dose dual-energy CT with low-keV monochromatic image reconstructions performed better in phantom-based vessel cross-sectional segmentation and proved to be noninferior in vivo. • Patients receiving reduced-iodine-dose dual-energy coronary CT angiography often had the venous catheter placed on the forearm or wrist without compromising image quality.
Up to now, COVID-19-related vascular changes were mainly described as thrombo-embolic events. A handful of researchers reported another type of vascular abnormality referred to as “vascular thickening” or “vascular enlargement,” without specifying whether the dilated vessels are arteries or veins nor providing a physiopathological hypothesis. Our observations indicate that the vascular dilatation occurs in the venous compartment, and underlying mechanisms might include increased blood flow due to inflammation and the activation of arteriovenous anastomoses.
C oronary subclavian steal syndrome (CSSS) is an uncommon complication after coronary artery bypass graft (CABG) surgery using the left internal mammary artery (LIMA). 1-3 CSSS results from the retrograde blood flow through the LIMA graft in the left subclavian artery (SCA), consecutive to a proximal SCA stenosis or total occlusion. CSSS usually manifests as stable angina pectoris 1 but also rarely presents as ST-segment-elevation myocardial infarc-tion secondary to an acute SCA occlusion or plaque rupture. 1,2 Anterior ST-segment-elevation myocardial infarction resulting from an acute thrombotic occlusion of the left anterior descending (LAD) artery at the LIMA-to-LAD anastomotic site in a patient with concomitant CSSS may be a challenging problem during primary percutaneous coronary intervention and has not been reported to date. Here, we report on a 62-year-old woman with hypertension, dyslipidemia, and peripheral artery disease who underwent CABG surgery using a LIMA graft to the LAD 12 years earlier (Figure 1 and Movie I in the online-only Data Supplement). The patient presented to the emergency department with de novo exertional chest pain. The 12-lead ECG showed negative T waves in the anterior leads, and her cardiac biomarkers were normal. During admission, the patient developed chest pain at rest associated with paresthesias of the left hand. An ECG showed new anterior ST-segment elevation, and the patient was transferred for primary percutaneous coronary intervention. The left coronary angiogram (Movie II in the online-only Data Supplement) showed a patent LAD with critical stenosis at the site of the LIMA-to-LAD anastomosis (Figure 1) and an unexpected retrograde flow through the patent LIMA graft to the left SCA (Figure 1). Interestingly, no angiographically significant stenosis was visualized on the proximal native LAD. An angiogram of the aortic root revealed total occlusion at the origin of the left SCA (Figure 1 and Movie III in the online-only Data Supplement), which, combined with the retrograde flow through the LIMA, confirmed the presence of CSSS with vascularization of the left upper limb depending on the reversed flow through the LIMA graft. Primary percutaneous coronary intervention to the LAD was performed with a drug-eluting stent across the LIMA-to-LAD anastomotic site. The final coronary angiogram (Movie IV in the online-only Data Supplement) demonstrated a restored anterograde flow from the proximal to the distal LAD and a preserved retrograde flow through the LIMA graft to the left SCA (Figure 1). Physical examination revealed a weaker left radial pulse, but plethys-mography confirmed a biphasic pulse wave at the level of the left upper limb. An urgent Doppler ultrasonography showed occlusion of the left SCA and CSSS with reversed flow in the LIMA and anterograde flow in the left vertebral artery. No critical left upper-limb ischemia was documented, and conservative management was suggested. Computed tomographic angiography demonstrated a 15-mm total occlusion at the origin of the le...
Intracavitary electrocardiography is an accurate guidance technique for peripherally inserted central catheters (PICC) tip location that is spreading widely among providers using non x-ray-based facilities. The principle behind this technology relies on the transmission of the electrocardiographic signal at the tip of the catheter and its use as an internal mobile electrode, allowing the system to identify the cavo-atrial junction (CAJ) through internal P-wave amplitude modulations. The gain in popularity of intracavitary electrography and its large diffusion have led manufacturers to offer various devices with heterogeneous properties, among which clinician who place PICCs have to choose. It is therefore important to understand differences between available techniques and devices. The potential impact might not only affect availability and costs but also the clinical impact through advantages and limitations regarding electric signal transmission PICC selection. Current perspectives on intracavitary electrocardiography will also be discussed, to give the reader a global view of the management of electrocardiographically guided PICCs, especially in an environment without x-ray support.
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