Aortic Bifurcation Research Articles

Abstract 13826: Automatic Aorta Segmentation in Positron Emission Tomography Computed Tomography Using a 3D U-Net

Introduction: Noninvasive imaging techniques play a central role in identification, stratification, and follow-up of infectious and inflammatory vascular disease. Manual or semi-automatic quantification of these diseases is time consuming. Besides that, most fully automated analysis software fails to integrate information obtained from hybrid nuclear medicine images like PET/CT. The aim of this study is to develop an accurate, fast, and fully automated algorithm to segment the aorta on low dose CT (LDCT) as a navigator for PET-assessed vascular disease. Methods: Eighteen non-contrast LDCT scans from [ 18 fluor]fluordeoxyglucose ([ 18 F]FDG) PET/CT scans were used. The aorta was manually delineated from aortic valve to iliac bifurcation and used as ground truth. Split, rotation, and noise addition augmentation was used on fifteen scans to create 100 3D patches, which were split into a training (n=80) and validation (n=20) set. Three scans were used as test set. Cropping, normalization, and zero-centering were used for image preprocessing to speed up and improve accuracy of the training. No down sampling was used. A U-Net architecture was modified to process 3D inputs and outputs. The Dice Similarity Metric (DSM) was used to assess algorithm performance. Results: Fully automated segmentation of the aorta was feasible training a modified 3D U-Net on non-contrast LDCT obtained from PET/CT scans. The test set yielded a DSM of 0.846 ± 0.020 (mean ± SD) for the entire aorta. The run time for the test set with the trained 3D U-Net was on average 2 seconds per patient, whereas the manual delineation was in the order of 30 minutes per patient. Conclusions: Comparisons of ground truth and automatic segmentations using the trained 3D U-Net demonstrated excellent concordance. This method can be used for faster and more in-depth analyses of PET tracer uptake in the vascular wall and potentially applied for fast and accurate quantification of inflammatory and infectious vascular diseases.

Real-Time Evaluation of Blood Flow Patterns Using AneurysmFlow for an in vivo Abdominal Aortic Aneurysm Model

Many new tools for abdominal aortic aneurysm (AAA) rupture risk evaluation have been developed. These new tools need detailed hemodynamic information in AAA. However, hemodynamic data obtained from in vivo research are lacking. Thus, the objective of this study was to analyze blood flow patterns in an in vivo AAA model to acquire real-time hemodynamic information using AneurysmFlow, a novel flow evaluation system. Digital subtraction angiography images of patients who underwent endovascular aneurysm repair were analyzed using the visualization function of the AneurysmFlow to classify blood flow patterns as laminar or turbulent flow. The presence of boundary layer separation was also evaluated. The time taken for contrast medium to travel from the infrarenal aortic neck to aortic bifurcation was acquired to calculate the flow velocity. Associations between characteristics of aneurysm including lumen occupying ratio of intraluminal thrombus (ILT) and the hemodynamic flow pattern were evaluated. A total of 37 AAA patients was enrolled. Their blood flow patterns were evaluated using the AneurysmFlow. Logistic regression analyses with lumen occupying ratio of ILT as an independent variable showed that the larger the lumen occupying ratio of ILT, the more likely the aneurysm was to show a laminar pattern (P=0.03), and the more likely the boundary layer separation would not exist (P=0.04). The flow velocity from the infrarenal aortic neck to the aortic bifurcation showed a positive association with the lumen occupying ratio of the ILT in linear regression analysis (P < 0.001). Hemodynamic analysis of AAA with the AneurysmFlow using real-time individual patient models showed different flow patterns and flow velocities depending on ILT. This novel analytic approach using AneurysmFlow has potential to play an important role in obtaining clinically meaningful hemodynamic information of AAA.

Midterm outcomes of the covered endovascular reconstruction of the aortic bifurcation for aortoiliac occlusive disease in a latinoamerican population.

IntroductionSurgical approach of aortoiliac occlusive disease (AOD) with aorto-bi-femoral graft or endarterectomy, has been the first line treatment with patency rates up to 90%. Nevertheless, this procedure has an early mortality rate of 4%. Vascular complications of aorto-bi-femoral graft have an average incidence of 5–10% and development of incisional hernia in 10% of the cases. The Covered Endovascular Reconstruction of Aortic Bifurcation or CERAB technique, as a new approach is shaping up to be a promising approach. However, there are few studies in Latin America and the Caribbean.Materials and methodsRetrospective multicenter study. All patients treated with the CERAB technique between February 2015 and June 2021 in three hospitals.ResultsA total of 9 patients (5 male and 4 female) were treated with the CERAB technique. Only one patient died. Of the total number of patients, 41.2% had a TASC II - C classification, and 58.8% had a TASC II - D classification. Complications included dissection in only 2 patients, massive bleeding in 1 patient and hematoma in 3 patients. The average number of days in critical care was 1.2 days and 2.6 in hospitalization. Two patients required endovascular reintervention. Primary patency was present in 66.7% of the patients.DiscussionThe CERAB technique presents a low morbidity and mortality with an 88.9% of technical success rate. None of our patients needed Chimney CERAB procedure. Our results are similar to those reported in the literature, where they report primary patency rates between 82% and 97%.

Finite element computation of magneto-hemodynamic flow and heat transfer in a bifurcated artery with saccular aneurysm using the Carreau-Yasuda biorheological model.

"Existing computational fluid dynamics studies of blood flows have demonstrated that the lower wall stress and higher oscillatory shear index might be the cause of acceleration in atherogenesis of vascular walls in hemodynamics. To prevent the chances of aneurysm wall rupture in the saccular aneurysm at distal aortic bifurcation, clinical biomagnetic studies have shown that extra-corporeal magnetic fields can be deployed to regulate the blood flow. Motivated by these developments, in the current study a finite element computational fluid dynamics simulation has been conducted of unsteady two-dimensional non-Newtonian magneto-hemodynamic heat transfer in electrically conducting blood flow in a bifurcated artery featuring a saccular aneurysm. The fluid flow is assumed to be pulsatile, non-Newtonian and incompressible. The Carreau-Yasuda model is adopted for blood to mimic non-Newtonian characteristics. The transformed equations with appropriate boundary conditions are solved numerically by employing the finite element method with the variational approach in the FreeFEM++ code. Hydrodynamic and thermal characteristics are elucidated in detail for the effects of key non-dimensional parameters i.e. Reynolds number (Re = 14, 21, 100, 200), Prandtl number (Pr = 14, 21) and magnetic body force parameter (Hartmann number) (M = 0.6, 1.2, 1.5) at the aneurysm and throughout the arterial domain. The influence of vessel geometry on blood flow characteristics i.e. velocity, pressure and temperature fields are also visualized through instantaneous contour patterns. It is found that an increase in the magnetic parameter reduces the pressure but increases the skin-friction coefficient in the domain. The temperature decreases at the parent artery (inlet) and both the distant and prior artery with the increment in the Prandtl number. A higher Reynolds number also causes a reduction in velocity as well as in pressure. The blood flow shows different characteristic contours with time variation at the aneurysm as well as in the arterial segment. The novelty of the current research is therefore to present a combined approach amalgamating the Carreau-Yasuda model, heat transfer and magnetohydrodynamics with complex geometric features in realistic arterial hemodynamics with extensive visualization and interpretation, in order to generalize and extend previous studies. In previous studies these features have been considered separately and not simultaneously as in the current study. The present simulations reveal some novel features of biomagnetic hemodynamics in bifurcated arterial transport featuring a saccular aneurysm which are envisaged to be of relevance in furnishing improved characterization of the rheological biomagnetic hemodynamics of realistic aneurysmic bifurcations in clinical assessment, diagnosis and magnetic-assisted treatment of cardiovascular disease."

Experimental study of the flow in the elastic model of the abdominal aortic bifurcation

This paper reflected preliminary results of physical modeling of pulsating flow in a model of abdominal aortic bifurcation with taking into account the physiological elasticity of the vessel walls. Elastic vessel models were made via molding from a silicone mixture based on Lasil-T4 silicone rubber. The auxiliary study was performed to assess the elastic properties of the silicone mixture and select a necessary composition. The experiment on the pulsating flow in the rigid and elastic models of the abdominal aortic bifurcation was carried out using a blood flow simulator with circulation of blood-emulating fluid. It was revealed that interaction between the elastic model and closed rigid circuit of the blood flow simulator resulted in generation of intense parasite flow oscillations and prevented from getting similar flow conditions for rigid and elastic models. A way to solve the problem is to include dampers with liquid in the hydraulic circuit of the blood flow simulator at the inlet and the outlets of the elastic model.

Wall Shear Stress-Based Hemodynamic Descriptors in the ‎Abdominal Aorta Bifurcation: Analysis of a Case Study

The knowledge of hemodynamic behaviour in the abdominal aorta artery bifurcation is of great ‎importance for the early diagnosis of several cardiovascular diseases common in this bifurcation. The ‎work developed focuses on a case study of hemodynamic in the abdominal aorta artery bifurcation, ‎based on a realistic 3D geometric model reconstructed from 2D medical images of a real patient. ‎Hemodynamic quantities based on the wall shear stress (WSS) of the abdominal aorta bifurcation are ‎analysed and is presented an alternative analysis of the well-established stress hemodynamic descriptors ‎to identify specific zones of the artery with a higher probability of developing cardiovascular diseases. ‎The individual analysis of different zones of the artery allowed to obtain information that can remain ‎masked when whole artery is considered as a single zone. The reported results provide a correlation ‎between the analysed stress hemodynamic descriptors and the area of the wall artery. Then, the aim of ‎this work is the identification of regions at the luminal surface subject to atherosusceptible WSS ‎phenotypes. For the patient studied, the analysis presented allowed the identification of the patient's ‎propensity to develop atherosclerosis, according to the hemodynamic descriptors time-averaged WSS ‎‎(TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). Thus, this work offers a new ‎way of looking to the stress hemodynamic descriptors.‎

TP5.2.5 The utility of ‘kissing’ common iliac artery stents in the management of occlusive atherosclerotic arterial disease of the aortic bifurcation

Abstract Introduction A systematic review published in 2017 concluded that ‘kissing’ iliac stents to treat occlusive disease of the aortic bifurcation was associated with high technical procedural success and good medium-term patency. We have explored this in a regional vascular unit. Methods Retrospective review of patients managed with endovascular treatment of aorto-iliac segment (March 2015 to September 2020). The median follow-up was 2-years. Key outcome variables included the patency of the reconstruction and requirement for secondary intervention. Results There were 1,348 iliac endovascular procedures performed for occlusive atherosclerotic arterial disease of the aorto-iliac segment of which 56 were ‘kissing’ iliac stents. Intervention was performed for chronic limb threatening ischaemia in 29 cases. In 37 cases patients had unilateral symptoms only and in 41 cases patients had either TASC A or B lesions. Technical success was achieved in 55 cases and the median duration of admission was 1-day. At follow-up there was clinical patency in 54 cases, although there were 3 major extremity amputations performed (all on the index admission). Conclusion As with much of the work on ‘kissing’ iliac stents the number of patients is small and the group of patients variable in terms of medical co-morbidity, presenting clinical features and morphology of iliac disease. The procedure appears to have high technical success and can be achieved with little in the way of major morbidity. Medium term durability is good.

A reappraisal of pediatric abdominal surface anatomy.

Surface anatomy is fundamental to clinical and surgical practices. As the surface anatomy varies with age, the purpose of this study is to provide age-standardized surface markings for the abdomen in children. A total of 155 abdominal computed tomography scans of healthy children aged 0-18 years were categorized into six groups, and the surface anatomy of the major vascular structures, solid viscera, and anatomical planes in the abdomen was analyzed. The vertebral levels of the celiac trunk, superior mesenteric artery, and hepatic portal vein formation were higher in the youngest age group, whereas the levels of the inferior mesenteric artery, formation of the inferior vena cava, and renal arteries did not differ with age. The right kidney lay between T12 and L3 and the left at T11-L3; however, both kidneys were in lower positions in younger children. The spleen was most commonly located between the 8th and 11th ribs except in toddlers. In all age groups, the hepatic portal vein formation was within the transpyloric plane and the aortic bifurcation was above the supracristal plane. In vivo reassessment of the surface anatomy enables the substantial variability of surface landmarks to be highlighted. This study demonstrates that taking account of age-related variations will increase the accuracy and therefore the clinical relevance of surface anatomy.

An Artificial Intelligence Approach for Automatic Delineation of Para-Aortic Clinical Target Volume

Treatment of metastatic para-aortic lymph nodes (PAN) is critical for locally advanced cervical cancer (LACC) control. However, the clinical target volume (CTV) delineation for the para-aortic region is tedious and time-consuming even for a well-trained radiation oncologist. In this study, we trained a deep learning (DL) segmentation network that led to automatic and accurate PAN-CTV delineation.We retrospectively collected 47 radiotherapy planning CTs of LACC patients. For each planning CT, the Aorta, Inferior Vena Cava (IVC) and PAN-CTV were manually delineated for radiotherapy treatment planning for the elective para-aortic region from the left renal vein to the aortic bifurcation. The PAN-CTV was prophylactically contoured (ignoring gross para-aortic nodes) according to the recent Small et al. (2020) consensus guidelines. For each CT set, the spine structures were automatically delineated using threshold- and morphology-based segmentation. Then, all CTs were registered to a common reference frame based on the delineated spine structures and cropped to dimensions of 15 cm x 15 cm x 20 cm centered along the spine. A U-Net-based DL segmentation network was developed and trained to automatically segment Spine, Aorta, IVC, and PAN-CTV in the registered and cropped region. The segmented structures were converted into DICOM RTStruct with the original CT association.We used 32 CTs for training, 8 for validation, and 7 for testing. The Dice coefficient (DC) and Hausdorff distance (HD95) were used as the evaluation metrics. The mean (std) DC of PAN-CTV for training, validation and test sets were 0.911 (0.027), 0.757 (0.046) and 0.755 (0.073), respectively. The mean (std) HD95 of PAN-CTV for training, validation and test sets were 2.39 (2.77) mm, 10.12 (6.83) mm and 8.42 (4.52) mm, respectively. All testing PAN-CTVs were visually checked by an attending radiation oncologist specializing in gynecologic malignancies and deemed clinically acceptable.An Artificial Intelligence approach comprised of registration and DL network was developed and validated for automatic segmentation of Spine, Aorta, IVC, and PAN-CTV in LACC. Registration was used to improve the boundary definition of the virtual structure, PAN-CTV, for DL segmentation without human intervention. This approach could facilitate efficient workflow and allow for optimal dose delivery to the involved nodal basins in LACC.W. Chi: None. P. D'Cunha: None. M. Chen: None. L. Ma: None. M. Kazemimoghadam: None. Z. Yang: None. X. Gu: None. K.V. Albuquerque: Research Grant; Astra Zeneca. Honoraria; ACR, ARRT. Travel Expenses; ACR, ARRT, ASCO.W. Lu: None.

P01 Catastrophic antiphospholipid syndrome presenting as diffuse peripheral and central thromboses

P01 Catastrophic antiphospholipid syndrome presenting as diffuse peripheral and central thromboses

Clinical Implications of Anatomic Variations of the Presacral Space

<h3>Study Objective</h3> To describe the presacral space and the spatial relationship between key anatomic landmarks, demonstrate anatomic variations in the presacral space, and discuss the clinical implications as they relate to minimally invasive surgery. <h3>Design</h3> Video description of key landmarks found in the presacral space, the fundamental steps of a presacral neurectomy, cases with anatomic variations of the presacral space, and clinical implications. Patients provided consent for the video and publication. This video with no identifying patient data was exempt from Institutional Review Boards Approval. <h3>Setting</h3> Video laparoscopy was performed. <h3>Patients or Participants</h3> We present patients with anatomic variations of the presacral space as well as cases demonstrating the clinical implications. <h3>Interventions</h3> Once the presacral space is entered, there are key landmarks to note. In a presacral neurectomy, the peritoneum overlying the sacral promontory is elevated and a small opening is made. The peritoneum is incised horizontally and vertically, and the opening is extended cephalad to the aortic bifurcation. Retroperitoneal lymphatic tissue including the nerve fibers of the hypogastric plexus are skeletonized, desiccated, and excised. All of the nerve fibers within the boundaries of the Triangle of Cotte are removed, including those entering the area from under the common iliac arteries and over the left common iliac vein. <h3>Measurements and Main Results</h3> The procedures that warrant dissection in this area include presacral neurectomy, sacropexy, lymphadenectomy, and certain cases of bowel mobilization. The clinical implications of anatomic variations are important to consider prior to abdominal entry and dissection of the presacral space to decrease the risk of surgical complications<b>.</b> <h3>Conclusion</h3> The anatomic pattern of the presacral space is variable, major vessels may deviate significantly from their expected positions, and prior to entering the space, surgeons should be careful to have full exposure.

Oblique Lumbar Interbody Fusion From L2 to S1: 2-Dimensional Operative Video.

This surgical video demonstrates the technique of an oblique lumbar interbody fusion (OLIF) in the lumbar spine from L2 to L5 as well as an oblique approach to the L5-S1 level. It demonstrates the surgical approach, technical nuances of OLIF, and pearls of the surgery. The video discusses the importance of the release of the disc space to allow for height restoration and deformity correction, endplate preparation to enhance arthrodesis, and appropriate implant sizing. The concept of the approach is the minimally invasive blunt dissection through the abdominal wall musculature and mobilization of the retroperitoneal fat. Unlike the transpsoas approach, the surgery is performed anterior to the psoas, avoiding the lumbar plexus.1 For L5-S1, the approach is still performed in the lateral position but with an oblique approach. A vascular surgeon performs the L5-S1 approach, and the disc space is accessed through the iliac bifurcation.2 The discectomy and interbody fusion are performed similarly to a standard anterior lumbar interbody fusion (ALIF), but in a lateral position and at an oblique angle. The patient consented to this procedure and for filming a video of this case.

Use of the AFX Stent Graft in Patients with Extremely Narrow Aortic Bifurcation: A Multicenter Retrospective Study.

Introduction This study analyzed the patient outcomes following endovascular aortic aneurysm repair (EVAR) for infrarenal aortic pathologies with very narrow aortic bifurcations using the AFX stent graft. Methods The data was retrieved from the archived medical records of 35 patients treated for abdominal aortic aneurysm (AAA) (48.6%) or penetrating aortic ulcer (PAU) (51.4%) with very narrow aortic bifurcation between January 2013 and May 2020. Patient survival, freedom from endoleak (EL), and limb occlusion were estimated applying the Kaplan–Meier method. Results The mean follow-up time was 20.4 ± 22.8 months. The mean aortic bifurcation diameter was 15.8 ± 2.2 mm. Technical success was 100%, and no procedure-related deaths occurred. Two type II ELs occurred within 30-day follow-up. We observed one common iliac artery stenosis at four months and one type III EL at 54 months in the same patient, both of which required re-intervention. Overall patient survival was 95 ± 5% (AAA: 100%; PAU: 89 ± 10%), freedom from limb occlusion was 94 ± 5% (AAA: 91 ± 9%; PAU: 100%), freedom from type II EL was 94 ± 4% (AAA: 88 ± 8%; PAU: 100%), and freedom from EL type III was 83 ± 15% (AAA: 80 ± 18%; PAU: 100%) at the end of the follow-up period. Conclusions Very narrow aortic bifurcations may predispose patients to procedure-related complications following EVAR. Our results suggest a safe use of the AFX stent graft in such scenarios. The overall short- and long-term procedure-related patient outcomes are satisfying albeit they may seem superior for PAU when compared to AAA.

Comparison of Human Renal Arteries in Cadavers and in Computed Tomography Scans – A Morphometric Study

Introduction: The right and left kidneys receive their blood supply from the lateral branches of the abdominal aorta that is, respectively, from the right and the left renal arteries. The study of renal arteries is thus very important, but the literature shows a scarcity of data for the Indian population. This study was, therefore, planned to compare the morphometry of human renal arteries in cadavers and in computed tomography scans. Material and Methods: The study was conducted on 36 formalin-fixed cadavers and on 36 computed tomographic scans of renal arteries. The various parameters measured included the length of renal arteries, internal diameter of renal arteries at its origin, the vertical distance between the renal arteries at its origin and the point of bifurcation of the aorta, and vertical distance between the origins of the right and left renal arteries. Results: The length of the right renal artery was more than the left renal artery, there was no difference in the internal diameter of both the vessels at their origin and no difference in the vertical distance between the site of origin of renal arteries and bifurcation of Aorta. Discussion and Conclusion: The information of the right renal artery being longer than the left kidney confirms with the data available in the literature. The vertical distance between the origins of the renal artery and bifurcation of the aorta is important as it aids the radiologists for performing angiography. Furthermore, the data from this study would aid and supplement the preexisting data for the surgeons during renal transplantations.

Idiopathic midaortic syndrome.

Midaortic syndrome (MAS) is characterized by narrowing of the descending aorta between the distal aortic arch and the aortic bifurcation. We present the case of a 4-year-old male presenting with a murmur and diagnosed with MAS. He was treated with a thoracoabdominal bypass graft.

AN ATYPICAL PRESENTATION OF AN ACUTE AORTIC DISSECTION: A CASE REPORT

TOPIC: Signs and Symptoms of Chest Diseases TYPE: Medical Student/Resident Case Reports INTRODUCTION: An acute aortic dissection (AAD) is defined as a tear in the intimal layer of the aorta and is considered a rare cardiovascular event [1]. AAD can contribute to the weakening of the adjacent aortic intimal layer, thereby resulting in the expansion of the dissection to other arteries, reduction of blood flow through the aortic lumen, and reduction of vital organ perfusion [2]. We present a case of a painless AAD, which was identified after a syncopal episode and manifested as right lower extremity weakness along with a "lump in the throat." CASE PRESENTATION: A 70 year old female with a history of hypertension presented to the emergency department (ED) after having a syncopal episode just prior to arrival. The patient denied any pain but reported non-specific tightness in her neck and new-onset right lower extremity weakness. Neurological examination revealed reduced muscle strength and decreased sensitivity to light touch in the right lower extremity. Computed tomography (CT) Angiography of the head and neck revealed a dissection involving a significant portion of the aortic arch and the brachiocephalic, left common carotid, and subclavian arteries. The dissection of the left subclavian artery extended to the left vertebral artery. CT of the chest, abdomen, and pelvis with contrast revealed a type I aortic dissection that extended from the aortic root to the aortic bifurcation. The patient was subsequently transferred to our tertiary care center and underwent emergent vascular surgery. DISCUSSION: An AAD classically presents with severe, acute chest, abdominal, or back pain [3]. Atypical symptoms include migratory pain [4], nonspecific gastrointestinal symptoms such as vomiting or diarrhea [5], and neurological symptoms such as seizures, syncope, paraparesis, and ischemic neuropathy [6]. Painless AAD has been associated with persistent altered mental status, syncope, and focal neurological deficits [7]. Early diagnosis is critical due to its high mortality rate [1]. Barriers to early diagnosis include identification of individuals with little to mild pain [8] as well as understanding the differing presentations between genders. Although less frequently affected by AAD, women tend to present at an older age, with atypical symptoms, and demonstrate higher mortality rates when compared to their male counterparts [9]. CONCLUSIONS: Acute aortic dissection can have a wide array of presentations that may often imitate common cardiovascular conditions. This case underscores the importance of maintaining a high index of suspicion for AAD in the presence of well established risk factors and non-specific symptom presentations. REFERENCE #1: Sen I, Erben YM, Franco-Mesa C, DeMartino RR. Epidemiology of aortic dissection. Semin Vasc Surg. 2021;34(1):10-17 REFERENCE #2: Juang D, Braverman AC, Eagle K. Aortic dissection. Circulation. 2008 Sep 30;118(14):e507-10. doi: 10.1161/CIRCULATIONAHA.108.799908. PMID: 18824647. REFERENCE #3: Siegal EM. Acute aortic dissection. J Hosp Med. 2006;1(2):94-105. doi:10.1002/jhm.69 DISCLOSURES: No relevant relationships by Taylor Charter, source=Web Response No relevant relationships by Winnie Chu, source=Web Response No relevant relationships by Elise Hsu, source=Web Response No relevant relationships by Minyoung Park, source=Web Response No relevant relationships by Samantha Shetty, source=Web Response

Pattern of Recurrence After Stereotactic Radiotherapy in Prostate Cancer Patients With Nodal Pelvic Relapse. A Multi-Institutional Retrospective Analysis

AimsCurrently, when nodal pelvic oligorecurrent disease is detected, no standard treatment option is recommended. One possible salvage option is nodal stereotactic body radiotherapy (SBRT). Here we analysed recurrence patterns after nodal SBRT in patients affected by pelvic oligometastatic relapse after radical prostatectomy, and androgen deprivation therapy (ADT)-free survival in this population. Materials and methodsData on 93 patients consecutively treated in five different institutions for pelvic oligorecurrent disease were reviewed. Inclusion criteria were biochemical recurrence after radical prostatectomy and imaging showing three or fewer metachronous lymphoadenopathies under aortic bifurcation. Patients underwent SBRT on all sites of disease. Concomitant ADT was allowed. ResultsAfter a median follow-up of 20 months (interquartile range 11–41), 57 patients had post-SBRT radiological evidence of relapse, for a median disease-free survival (DFS) of 15 months (95% confidence interval 9–24). Concomitant ADT was administered in 20 patients (21.5%). Overall, eight (8.6%), 21 (22.6%) and 28 (30.1%) patients had prostate bed only, pelvic nodal or distant relapse, respectively. The median ADT-free survival was not reached. Concomitant ADT, International Society for Urologic Pathology pattern at diagnosis < or ≥3, time to relapse ≤ or >12 months, prostate-specific antigen at recurrence < or ≥1.10 ng/ml and prostate-specific membrane antigen staging were not significantly associated with DFS. After relapse, 42 patients (45.2%) received a second SBRT course. ConclusionNodal SBRT yielded encouraging DFS and ADT-free survival in this population. Only a minority of patients developed prostate bed recurrence, suggesting that local treatment may be safely avoided. A consistent percentage of patients could be managed with a second SBRT course.

Treatment of Symptomatic Paravisceral Aortic Thrombus Using Percutaneous Suction Thrombectomy

Paravisceral aortic thrombus in an otherwise normal aorta is rare. A hemodynamically significant thrombus burden in such patients can result in visceral malperfusion and bilateral lower extremity ischemia, both of which, historically, have a high mortality rate. Open thrombectomy via a thoracoabdominal approach is associated with high mortality. Other endovascular alternatives, including Fogerty embolectomy and mechanical thrombectomy, are associated with visceral embolization. The Penumbra CAT-12 lightning device (Penumbra Inc, Alameda, Calif) most commonly used to treat ileofemoral deep vein thrombosis is a 12F suction catheter with the ability to remove large amounts of clot burden with minimal blood loss owing to its sensor mechanism. The ability to suction thrombectomy-focused areas in the aorta reduces the likelihood of embolization. We have presented the cases of two patients with acute symptomatic paravisceral aortic thrombus who were treated with this device and their outcomes. Two patients had presented to the emergency room with acute onset abdominal pain and bilateral lower extremity rest pain and numbness. Patient 1 was a 46-year-old woman with antithrombin III and protein C deficiency (Fig 1). Patient 2 was a 78-year-old woman with recent coronavirus disease 2019 infection, chronic obstructive pulmonary disease, and congestive heart failure (Fig 2). Computed tomography angiography of patients demonstrated aortic thrombus in the paravisceral aorta extending from the supraceliac to the infrarenal aorta. Both patients underwent percutaneous suction thrombectomy of the aorta using the Penumbra CAT-12 lightning device. Patient 2 also underwent bilateral femoral cutdown, thrombectomy, and kissing iliac stents, followed by diagnostic laparoscopy without any further intervention. The intraoperative angiographic images demonstrated the initial aortic thrombus in the paravisceral aorta with resolution of thrombus after suction thrombectomy (Figs 1 and 2). The abdominal pain and bilateral lower extremity rest pain had resolved in both patients postoperatively and did not require any further surgical intervention. Patient 1 was discharged home on postoperative day 3. Patient 2 was discharged to a rehabilitation facility on postoperative day 10. Percutaneous suction thrombectomy devices such as the Penumbra CAT-12 lightning device is effective in removing a large paravisceral aortic clot burden without any embolization to the visceral vessels. This is a newly available alternative to consider for such patients with symptomatic paravisceral aortic thrombus considered to have a high mortality risk with open intervention.Fig 2a, Angiogram demonstrating aortic thrombus at the level of the superior mesenteric artery. b, Coronal view of paravisceral aortic thrombus. c, Abdominal aortogram demonstrating improvement in paravisceral thrombus burden with embolization of thrombus to the aortic bifurcation. d, Lateral aortogram demonstrating patent and disease-free celiac and superior mesenteric artery. e, Aortogram after bilateral femoral embolectomy and bilateral kissing iliac stents showing flow to the lower extremity and pelvis restored with no further thrombus burden. f, Post-op CTA demonstrating aortic lumen patency at the SMA take-off.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Simultaneous acute limb ischemia related to acute Leriche syndrome and pulmonary embolism without existing patent foramen ovale: a case report

BackgroundAortoiliac occlusion disease, also called Leriche syndrome, is characterized by atherothrombotic obliteration of the aortic bifurcation and bilateral common iliac arteries; typically, it has a chronic presentation. Pulmonary embolism is more related to venous thromboembolism rather than arterial thromboembolic events. Therefore, cases of simultaneous acute Leriche syndrome and pulmonary embolism are rare. Existing intracardiac right-to-left shunt were detected in most previous cases. Herein, we present the first likely documented case wherein acute Leriche syndrome and pulmonary embolism occurred simultaneously without a patent foramen ovale.Case presentationA 58-year-old man with hyperlipidemia and coronary artery disease presented with a 4-h history of bilateral lower limb numbness. He was a heavy smoker with a history of stroke. Computed tomography angiography revealed pulmonary embolism and aortoiliac artery occlusion. Although a massive thrombus straddled the bilateral pulmonary arteries, orthopnea was his only presentation, without right ventricle failure. Cyanosis of the affected limbs was noted, and muscle strength in both limbs had regressed to grade 1. Owing to acute limb ischemia, he underwent an emergency operation to salvage the limbs. On postoperative day 5, the general condition of both the legs improved; the muscle strength improved to grade 4. He was then transferred to the general ward and enoxaparin was continued. Computed tomography angiography was repeated to evaluate the pulmonary embolism on postoperative day 8; the thrombus remained lodged in the bilateral main pulmonary arteries. Owing to persistent orthopnea and chest tightness with intermittent tachycardia, he underwent a staged operation for the pulmonary embolism on postoperative day 13. During the surgery, intraoperative transesophageal echocardiography showed no patent foramen ovale or an existing right-to-left shunt. Postoperatively, he was closely monitored in the intensive care unit for 3 days and then transferred to the general ward for 10 days. A final computed tomography angiography performed on postoperative day 18 revealed thrombus resolution. He was then discharged on postoperative day 30 without any in-hospital complications.ConclusionWe present a case that might be the first documented report of acute Leriche syndrome co-occurring with pulmonary embolism without an existing patent foramen ovale.

Neutrophil extracellular traps in feline cardiogenic arterial thrombi: a pilot study.

The aim of this study was to investigate the spatial distribution of neutrophil extracellular traps (NETs) in cardiogenic arterial thromboembolism (CATE). Specifically, we aimed to examine the related structural features of NETs in feline arterial thrombi in relation to their arterial locations. Paraffin-embedded aortic bifurcations from nine cats with hypertrophic cardiomyopathy (four with CATE and five without) were deparaffinized, and NETs were identified by immunodetection based on colocalization of cell-free DNA, citrullinated histone H3 and neutrophil elastase. The distribution of NETs in thrombi within the aortic bifurcations and common iliac arteries (CIAs) was compared based on their proximity to the descending aorta (proximal, mid, distal). Ten random fields per section were captured at × 10 and × 20 magnification for each section of the clot and analyzed. The distributions of NETs in thrombi within the aortic bifurcation and CIAs were found to differ in relation to their assigned zones (proximal, mid, distal; P = 0.04); NETs were concentrated mostly in the proximal region in the aortic bifurcations (47.56%, interquartile range [IQR] 14.07-77.95) and CIAs (44.69%, IQR 24.65-85.28), compared with the distal regions (2.69%, IQR 0.10-50.04 [P = 0.027]; 7.08%, IQR 1.27-59.33 [P = 0.02]). The variation in NET distribution within arterial thrombi may shed light on the pathogenesis of thrombus growth. This may be due to possible neutrophil entrapment or variations in shear stress.