Image fusion using the two-dimensional-three-dimensional registration method helps reduce contrast medium volume, fluoroscopy time, and procedure time in hybrid thoracic endovascular aortic repairs

Implications of aortic neck dilation following thoracic endovascular aortic repair

OBJECTIVE

This article reports on a retrospective observational study designed to evaluate the incidence, etiology, and clinical implications of aortic neck dilation following thoracic endovascular aortic repair (TEVAR) for aneurysms with landing zones II and III.

METHODS

The study included 37 patients who underwent TEVAR and had postoperative computed tomography angiography available within 30 days and at least one computed tomography angiography at 1 year postoperatively. The primary end point was proximal aortic dilation (defined as growth ≥5 mm or ≥10% of the original diameter), and secondary end points included annual growth of the aneurysmal sac, device migration, endoleak, and reintervention with additional neck-related adverse events. The measurements taken during follow-up included the maximum diameter of the aneurysm and aortic diameter at various locations relative to the stent graft.

RESULTS

During follow-up, a significant increase in aortic diameter was observed at the proximal edge of TEVAR. The estimated freedom from 5 mm or 10% proximal aortic neck growth at 1, 2, and 3 years was 81%, 70%, and 65%, respectively. At the proximal edge of TEVAR the type III aortic arch was significantly associated with 5 mm growth during follow-up (P = .047) and this growth (5 mm or 10%) as well as a 10% increase at +20 mm were significantly associated with more aortic-related reinterventions. Moreover, an aortic diameter at the start <36 mm was associated with a greater increase during follow-up (area under curve in receiver operating characteristic >80%; P < .05).

CONCLUSIONS

The study concludes that proximal aortic dilation after TEVAR is a common and progressive phenomenon, and the management strategies for aortic neck dilation, including surveillance, secondary interventions, and open conversion, should be considered carefully to optimize patient outcomes and improve the long-term success of the procedure.

Automated image fusion during endovascular aneurysm repair: a feasibility and accuracy study

PURPOSE

Image fusion merges preoperative computed tomography angiography (CTA) with live fluoroscopy during endovascular procedures to function as an overlay 3D roadmap. However, in most current systems, the registration between imaging modalities is performed manually by vertebral column matching which can be subjective, inaccurate and time consuming depending on experience. Our objective was to evaluate feasibility and accuracy of image-based automated 2D-3D image fusion between preoperative CTA and intraoperative fluoroscopy based on vertebral column matching.

METHODS

A single-center study with offline procedure data was conducted in 10 consecutive patients which had endovascular aortic repair in which we evaluated unreleased automated fusion software provided by Philips (Best, the Netherlands). Fluoroscopy and digital subtraction angiography images were collected after the procedures and the vertebral column was fused fully automatically. Primary endpoints were feasibility and accuracy of bone alignment (mm). Secondary endpoint was vascular alignment (mm) between the lowest renal artery orifices. Clinical non-inferiority was defined at a mismatch of < 1 mm.

RESULTS

In total, 87 automated measurements and 40 manual measurements were performed on vertebrae T12-L5 in all 10 patients. Manual correction was needed in 3 of the 10 patients due to incomplete visibility of the vertebral edges in the fluoroscopy image. Median difference between automated fusion and manual fusion was 0.1 mm for bone alignment (p = 0.94). The vascular alignment was 4.9 mm (0.7-17.5 mm) for manual and 5.5 mm (1.0-14.0 mm) for automated fusion. This did not improve, due to the presence of stiff wires and stent graft.

CONCLUSION

Automated image fusion was feasible when all vertebral edges were visible. Accuracy was non-inferior to manual image fusion regarding bone alignment. Future developments should focus on intraoperative image-based correction of vascular alignment.

The role of multimodal imaging in emergency vascular conditions: The journey from diagnosis to hybrid operating rooms

Multimodal imaging is the incorporation of two or more imaging modalities during the same examination, and it has both diagnostic and treatment applications. The use of image fusion for intraoperative guidance in endovascular interventions is being extended increasingly to the field of vascular surgery, especially in the context of hybrid operating rooms. The aim of this work was to perform a review and narrative synthesis of the available literature in order to report on current applications of multimodal imaging in diagnosis and treatment of emergent vascular conditions. Of 311 records selected in the initial search, 10 articles were included in the present review: 4 cohort studies and 6 case reports. The authors have presented their experience in treating ruptured abdominal aortic aneurysms; aortic dissections; traumas; standard endovascular aortic aneurysm repair, with or without deterioration of renal function; and complex endovascular aortic aneurysm repair, and reported on the long-term clinical results. Although the current literature about multimodal imaging application in emergency vascular conditions is limited, this review highlights the potential of image fusion in hybrid angio-surgical suites, especially for diagnosing and performing treatment in the same operating room, avoiding patient transfer, and allowing procedures with zero or low-dose contrast mean.

Favorable Remodeling After TEVAR in Uncomplicated Acute and Subacute Type B Aortic Dissection in Comparison to Conservative Treatment: A Midterm Analysis

PURPOSE

The purpose of the study was to evaluate the midterm and long-term outcomes of patients who underwent thoracic endovascular aortic repair (TEVAR) procedure to treat an uncomplicated acute and subacute type B aortic dissection (uATBAD) with high risk for subsequent aortic complications compared with the group of patients who received a conservative treatment protocol during the same period.

MATERIALS AND METHODS

Between 2008 and 2019, 35 patients who had TEVAR due to uATBAD and those with conservative procedure (n=18) were included in a retrospective analysis and follow-up study. The primary endpoints were false lumen thrombosis/perfusion, true lumen diameter, and aortic dilatation. The aortic-related mortality, reintervention, and long-term survival were the secondary endpoints.

RESULTS

In the study period, 53 patients (22 females) with a mean age of 61.1±13 years were included. No 30-day and in-hospital mortality was recorded. Permanent neurological deficits occurred in 2 patients (5.7%). In the TEVAR group (n=35) and in a median follow-up period of 34 months, a significant reduction of maximum aortic and false lumen diameter as well as a significant increase of true lumen diameter were detected (p<0.001 each). Complete false lumen thrombosis increased from 6% preoperatively to 60% at follow-up. The median difference in aortic, false lumen, and true lumen diameter was -5 mm (interquartile range [IQR]=-28 to 8 mm), -11 mm (IQR=-53 to 10 mm), and 7 mm (IQR=-13 to 17 mm), respectively. In 3 patients (8.6%), a reintervention was needed. Two patients (1 aortic-related) died during follow-up. The estimated survival according to Kaplan-Meyer analysis was 94.1% after 3 years and 87.5% after 5 years. Similar to the TEVAR group, no 30-day or in-hospital mortality was recorded in the conservative group. During follow-up, 2 patients died and 5 patients underwent conversion-TEVAR (28%). In a median follow-up period of 26 months (range=150), a significant increase of maximum aortic diameter (p=0.006) and a tendency to augmentation of the false lumen (p=0.06) were noted. No significant reduction of the true lumen was seen.

CONCLUSIONS

Thoracic endovascular aortic repair in patients at high risk of subsequent aortic complications in uncomplicated acute and subacute type B aortic dissection is safe and is associated with favorable midterm outcomes regarding aortic remodeling.

CLINICAL IMPACT

In a retrospective, single center analysis of prospectively collected data with follow-up, we compared 35 patients with high-risk features who recieved TEVAR in acute and sub-acute uncomplicated type B aortic dissection to a control-group (n=18). The TEVAR group showed a significant positive remoduling (reduction of max. aortic and false lumen diameter and increase of true lumen diameter (p<0.001 each)) during follow-up with an estimated survival of 94.1% after 3 years and 87.5% after 5 years.

New tools to reduce radiation exposure during aortic endovascular procedures

INTRODUCTION

The evolution of endovascular surgery over the past 30 years has made it possible to treat increasingly complex vascular pathologies with an endovascular method. Although this generally speeds up the patient's recovery, the risks of health problems caused by long-term exposure to radioactive radiation increase. This warrants the demand for radiation-reducing tools to reduce radiation exposure during these procedures.

AREAS COVERED

For this systematic review Pubmed, Embase and Cochrane library databases were searched on 28 December 2021 to provide an overview of tools that are currently used or have the potential to contribute to reducing radiation exposure during endovascular aortic procedures. In addition, an overview is presented of radiation characteristics of clinical studies comparing a (potential) radiation-reducing device with conventional fluoroscopy use.

EXPERT OPINION

Radiation-reducing instruments such as fiber optic shape sensing or electromagnetic tracking devices offer the possibility to further reduce or even eliminate the use of radiation during endovascular procedures. In an era of increasing endovascular interventional complexity and awareness of the health risks of long-term radiation exposure, the use of these technologies could have a major impact on an ongoing challenge to move toward radiation-free endovascular surgery.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

Technical Aspects of Branched Thoracic Arch Graft Implantation for Aortic Arch Pathologies

PURPOSE

To describe the implantation steps and tips and tricks for the Inner Branch Arch Endograft designed to treat aortic arch aneurysm and chronic type A aortic dissection.

TECHNIQUE

Anatomical suitability criteria should be met in order to use this device. The proximal segment of the graft lands in the ascending aorta distally to the sinotubular junction and the distal segment lands in the descending aorta. The device includes 2 inner branches; the proximal branch is used for a connection to the innominate artery (positioned slightly posterior at 12:30 o'clock), while the second branch is positioned slightly anterior at 11:30 o'clock and is used as a connection to the left common carotid artery. Access, implantation technique, deployment of the device, and catheterization of the branches are described thoroughly.

CONCLUSION

This Inner Branch Arch Endograft is an appealing alternative to treat aortic arch pathology, especially in patients unsuitable for open repair. Nevertheless, complex aortic arch repair is associated with a learning curve. Meticulous preoperative planning and a high level of concentration intraoperatively are mandatory.

Constrained stochastic state estimation of deformable 1D objects: Application to single-view 3D reconstruction of catheters with radio-opaque markers

Minimally invasive fluoroscopy-based procedures are the gold standard for diagnosis and treatment of various pathologies of the cardiovascular system. This kind of procedures imply for the clinicians to infer the 3D shape of the device from 2D images, which is known to be an ill-posed problem. In this paper we present a method to reconstruct the 3D shape of the interventional device, with the aim of improving the navigation. The method combines a physics-based simulation with non-linear Bayesian filter. Whereas the physics-based model provides a prediction of the shape of the device navigating within the blood vessels (taking into account non-linear interactions between the catheter and the surrounding anatomy), an Unscented Kalman Filter is used to correct the navigation model using 2D image features as external observations. The proposed framework has been evaluated on both synthetic and real data, under different model parameterizations, filter parameters tuning and external observations data-sets. Comparing the reconstructed 3D shape with a known ground truth, for the synthetic data-set, we obtained average values for 3D Hausdorff Distance of 0.81±0.53mm, for the 3D mean distance at the segment of 0.37±0.17mm and an average 3D tip error of 0.24±0.13mm. For the real data-set,we obtained an average 3D Hausdorff distance of 1.74±0.77mm, a average 3D mean distance at the distal segment of 0.91±0.14mm, an average 3D error on the tip of 0.53±0.09mm. These results show the ability of our method to retrieve the 3D shape of the device, under a variety of filter parameterizations and challenging conditions: uncertainties on model parameterization, ambiguous views and non-linear complex phenomena such as stick and slip motions.