History Of Abdominal Aortic Aneurysm Research Articles

The Role of Aortic Volume in the Natural History of Abdominal Aortic Aneurysms and Post-Endovascular Aortic Aneurysm Repair Surveillance.

There has been a debate about whether maximum diameter can be solely used to assess the natural history of abdominal aortic aneurysm. The aim of the present review is to collect all the available evidence on the role of abdominal aortic aneurysm (AAA) volume in the natural history of AAAs, including small untreated AAAs and AAAs treated by EVAR. The current literature appears to reinforce the role of volume as a supplementary measure for evaluating the natural history of AAA, in both intact AAAs and after EVAR. The clinical impact of AAA volume measurements remains unclear. Several studies show that volumetric analysis can assess changes in AAAs and predict successful endoluminal exclusion after EVAR more accurately than diameter. However, most studies lack strict standardized measurement criteria and well-defined outcome definitions. It remains unclear whether volumetry could replace diameter assessment in defining the risk of rupture of AAAs and identifying clinically relevant sac growth.

Clinical data, guidelines and real-world outcomes of endovascular iliac aneurysm repair with the GORE® EXCLUDER® Iliac Branch EndoprosthesisProvision of Services for People with Vascular Disease 2021

Isolated aneurysms of the iliac arteries are extremely rare. They most frequently occur in the common iliac artery (CIA) and are least frequent in the external iliac artery (EIA).1 Most (95%) affected patients are male and the median age of diagnosis is in the seventh decade of life.2 The underlying pathology of isolated iliac artery aneurysms is similar to that of abdominal aortic aneurysms. This includes degenerative aneurysm, pseudoaneurysm, penetrating ulcer, post-dissection aneurysm mycotic aneurysm, and traumatic aneurysm.3 Unlike patients with abdominal aortic aneurysms, those with iliac artery aneurysms present with symptoms of compression of other structures, particularly the ureter, sacral plexus and iliac veins. Reported growth rate of isolated iliac artery aneurysms is similar to that of abdominal aortic aneurysms. Ruptured isolated iliac artery aneurysms are associated with significant mortality,4 which is higher when treatment is undertaken as an emergency rather than an elective surgical procedure. Effective and timely intervention is therefore essential to improve survival. The aim of surgical treatment is to exclude the aneurysm from the circulation to prevent further growth and rupture. Traditional open surgical repair (OSR) was the mainstay of treatment but is technically challenging due to the location of the aneurysms in the pelvis and a frequent prior history of abdominal aortic aneurysms.1 Endovascular repair (EVAR) of isolated iliac artery aneurysms is a less invasive alternative to OSR. It is performed by a combination of branch-vessel coil embolisation and stent grafting, and has potential advantages over OSR in reducing perioperative morbidity and mortality.5 This supplement is a report of a satellite symposium held during the Vascular Societies' Annual Scientific Meeting in November 2022. It reviews clinical data, guidelines and real-world outcomes of endovascular iliac aneurysm repair with the GORE® EXCLUDER® Iliac Branch Endoprosthesis.

Characterization of small abdominal aortic aneurysms' growth status using spatial pattern analysis of aneurismal hemodynamics

Aneurysm hemodynamics is known for its crucial role in the natural history of abdominal aortic aneurysms (AAA). However, there is a lack of well-developed quantitative assessments for disturbed aneurysmal flow. Therefore, we aimed to develop innovative metrics for quantifying disturbed aneurysm hemodynamics and evaluate their effectiveness in predicting the growth status of AAAs, specifically distinguishing between fast-growing and slowly-growing aneurysms. The growth status of aneurysms was classified as fast (≥ 5 mm/year) or slow (< 5 mm/year) based on serial imaging over time. We conducted computational fluid dynamics (CFD) simulations on 70 patients with computed tomography (CT) angiography findings. By converting hemodynamics data (wall shear stress and velocity) located on unstructured meshes into image-like data, we enabled spatial pattern analysis using Radiomics methods, referred to as "Hemodynamics-informatics" (i.e., using informatics techniques to analyze hemodynamic data). Our best model achieved an AUROC of 0.93 and an accuracy of 87.83%, correctly identifying 82.00% of fast-growing and 90.75% of slowly-growing AAAs. Compared with six classification methods, the models incorporating hemodynamics-informatics exhibited an average improvement of 8.40% in AUROC and 7.95% in total accuracy. These preliminary results indicate that hemodynamics-informatics correlates with AAAs' growth status and aids in assessing their progression.

Type 2 Endoleak Detection After Endovascular Aneurysm Repair: Can Low-Flow Endoleaks Also Be Visualized in Silicon-Photomultiplier-Based Positron Emission Tomography/Computed Tomography Scans?

To present a novel clinical application of silicon-photomultiplier-based positron emission tomography (SiPM-based PET)/computed tomography (CT), detecting a type II endoleak 5 years after endovascular aneurysm repair (EVAR). SiPM-based PET/CT scans with a standard whole-body protocol were performed for a 73-year-old man with a past medical history of abdominal aortic aneurysms treated with EVAR and currently under investigation of his duodenal papillary carcinoma. The PET/CT demonstrated 18F-fluorodeoxyglucose (FDG) accumulation outside the stent graft in the native sac of the aneurysm. The site of accumulation corresponded to that of the contrast enhancement depicted in the CT angiography taken 1 month earlier. Another CT scan performed 3 months later revealed enlargement of the aneurysm. SiPM-based PET/CT, with its superior sensitivity and spatial resolution over conventional PET/CT, can detect type II low-flow endoleaks. Abnormal intra-aneurysmal FDG activity incidentally detected on SiPM-based PET/CT is worthy of attention because it may be indicative of endoleaks. Additional imaging using different modalities should be considered so that the patient would not miss the additional treatment opportunity upon observing sac enlargement. For patients with contraindications for iodine CT contrast media, SiPM-based PET/CT would serve as a suitable alternative.

Male-female differences in acute type B aortic dissection: the DisSEXion study

Abstract Background/Introduction Acute type B aortic dissection (ATBAD) is a cardiovascular emergency with high risk of morbidity and mortality. Elucidating male-female differences in ATBAD might help optimize patient-specific care, while data is scarce on this topic. Purpose The aim of this study was to identify differences between male and female ATBAD patients in presentation, management and outcomes. Methods A retrospective cohort study was conducted including all consecutive patients who presented with ATBAD between 2007–2017 in four tertiary centers. Non-acute, traumatic, and iatrogenic dissections were excluded. We included patients presenting with an intramural hematoma or penetrating aortic ulcer in acute setting. Results The study population consisted of 384 patients, of which 41% (n=156) was female. In comparison to males, females presented at an older age (67 [IQR: 57–73] vs. 62 [IQR: 52–71], p=0.015) and fewer female patients had a history of abdominal aortic aneurysm (6% vs. 15%, p=0.009). Imaging diagnostics revealed a smaller proportion of patients with distally extended dissections in females. DeBakey type IIIb was diagnosed less frequently in females (73% vs. 85%, p=0.008) as was renal artery involvement (48% vs. 66%, p=0.009). Furthermore, classical type B dissection was less often observed in female patients compared to male patients (56% vs. 78%, p&amp;lt;0.001). Absolute maximum thoracic aortic diameters were not significantly different in females and males (44.0 [38.0–50.0] mm vs. 42.0 [39.0–49.0], p=0.870). No male-female differences were found in treatment strategy (p=0.561, Figure 1). In-hospital/30-day mortality was 9.6% in female patients and 11.8% in male patients (p=0.603). Long-term mortality did not show a significant male-female difference (p=0.90) during a median follow-up duration of 6.1 [IQR: 4.1–9.1] years (Figure 2). Conclusion This study showed that female patients were older at presentation, while male patients more often had distally extended dissections. Although mortality was not significantly different, we encourage male-female specific risk factor studies on late mortality. In this way ATBAD male and female patients at high risk of mortality can be identified and patient-specific care can be implemented. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ZonMw

S3427 Implicit Bias Contributing to Delayed Diagnosis in a Rare Case of Endoscopic Biopsy Proven Gastrointestinal Amyloidosis

Introduction: Gastrointestinal amyloidosis often requires extensive workup to diagnose, but early diagnosis and initiation of treatment improves mortality.1 Implicit bias leads to narrow workups which can misdiagnose rare diseases. We present a case of gastrointestinal amyloidosis ultimately diagnosed by endoscopic biopsy. The rarity of this disease as well as bias that led to anchoring on more common diagnoses resulted in months of misdiagnosis. Case Description/Methods: A 67 year old woman with a history of abdominal aortic aneurysm (AAA), substance use disorder in remission, and chronic malnutrition presented with worsening of chronic abdominal pain. Workup over the course of eight prior ED visits for abdominal pain was unremarkable. Her pain was attributed to functional pain or opioid use and withdrawal despite a lack of documented opioid relapse. On this presentation, expanding AAA size prompted surgical consult. The surgical team expressed concern that she would not tolerate an open repair with a BMI of 13.9; TPN was started. GI recommended endoscopy to assess for a malabsorptive process. Unfortunately the procedure was delayed 22 days as the patient felt her uncontrolled pain was not validated by the care team. After many care conferences, she agreed to upper endoscopy which showed flattening of the villi of the duodenum. Microscopic testing from biopsies showed extensive amyloidosis (Figure). Amyloidosis resulting in intestinal ischemia was thought to be the cause of her pain and malnutrition. Discussion: Implicit bias associated with the patient’s history of addiction led to anchoring bias and initial narrow workup and misdiagnosis. Implicit bias amongst physicians regarding substance use disorders has been associated with suboptimal care.2 The severity of the patient’s abdominal pain and malnutrition should have prompted earlier referral to GI and may have led to expedited diagnosis of intestinal amyloidosis. Additionally, the frequent misdiagnosis and dismissal of symptoms resulted in mistrust leading the patient to decline further workup. Recognizing implicit bias can allow clinicians to provide more equitable workup and care.Figure 1.: DUODENUM, BIOPSY Amyloidosis, extensive, involving mucosa and submucosa, perivascular and diffuse.

S2361 Pancreatic Protrusion: A Rare Case of Grade IV Hiatal Hernia With Complete Pancreatic Herniation

Introduction: Hiatal hernias are commonly described as herniation of abdominal contents through the esophageal hiatus of the diaphragm. With this, classification systems exist to define hernias as either sliding or type one, or to consider types 2, 3 and 4 as paraesophageal which also present with other sequelae. While most commonly, hiatal hernias are type one and less severe in nature, 5 percent of cases become more involved and severe. The current prevalence of hernias ranges between 10 to 80 percent of North Americans. In this case, we shed light on the diagnosis and imaging of a rare sequelae of hiatal hernia which included not only small and large protrusion, but also herniation of the pancreas. Case Description/Methods: The patient is a 95 year old woman with a past medical history of abdominal aortic aneurysm as well as a large hiatal hernia presenting with a chief complaint of poor oral intake over the last several days prior to presentation. The patient was found to be significantly lethargic compared to baseline and reported decreased oral intake due to discomfort after eating. The patient’s initial vitals demonstrated a mild tachycardia with initial lab findings within normal ranges. A CT chest and abdomen was performed which demonstrated a large hiatal hernia, which now contained loops of small and large bowel as well as the pancreas. During the hospital course, interdisciplinary rounds were conducted in regards to the patient case with surgical and gastroenterology recommendations. The uniqueness of presentation of pancreatic protrusion was discussed as well as the current treatment and monitoring modalities of a Grade 4 hiatal hernia, now presenting with complications. Ultimately, the discussions were conducted with the patient who reported she was most amenable to comfort focused care with a pleasure based diet in an attempt to avoid any medical and surgical intervention. Discussion: In emergent cases, such as with respiratory distress and bowel strangulation, emergent surgical intervention is considered in cases of hiatal hernia. However, lesser defined and established are the findings and management as well as treatment modalities of more severe hernias involving protrusion of pancreatic contents. Here, we add to imaging the unique presentation of a common diagnosis with rare sequelae. We also hope to add to a growing body of literature on the imaging, and potential stepwise approach to management of type 4 hiatal hernias with severe and emergent treatment considerations.

Man With Abdominal Pain and Syncope

A 72-year-old man with a history of abdominal aortic aneurysm, status post-endovascular aneurysm repair, presented with worsening abdominal pain, weight loss, and syncope over the previous 2 months. He had a known thoracic aneurysm with a contained rupture for which the patient had declined intervention. Blood tests showed increased WBC counts of 16.3 × 109/L and hemoglobin of 8.3 g/dL, which was previously 11 g/dL. Computed tomography angiography demonstrated an enlarging aneurysm, with more contained blood and a suspected retroperitoneal mass (Figures 1 and 2).

Hyperaldosteronism and Renal Artery Stenosis in a Post-Abdominal Aortic Aneurysm Patient: A Case Report.

IntroductionPatients with history of abdominal aortic aneurysm (AAA) undergoing surgical repair can have a myriad of surgical complications including compromise to large arteries branching from the aorta. Secondary hyperaldosteronism, characterized by high levels of aldosterone and renin, can be due to a multitude of causes, including renal artery stenosis, and presents with nonspecific symptoms of fatigue, increased thirst, and muscle spasms. While it can initially be difficult to diagnose given its multitude of metabolic abnormalities, secondary hyperaldosteronism is important to consider in patients presenting with uncontrolled hypertension, hypokalemia, and metabolic alkalosis.Case ReportThis report explores the case of a 65-year-old male with a complicated medical history presenting to the emergency department with hypokalemia and hypertension six months after undergoing endovascular repair for an AAA and was found to have metabolic abnormalities including hypokalemia and metabolic alkalosis consistent with secondary hyperaldosteronism, likely secondary to renal artery stent stenosis. He was admitted to the hospital for four days and made a full recovery.ConclusionThis case highlights the need to understand, identify, and accurately diagnose hyperaldosteronism and recognize post-AAA repair complications of renal artery stenosis as a cause of this metabolic derangement.

Osteosarcoma of the bladder: a case report

BackgroundOsteosarcoma arising from the bladder is extremely rare, with only 38 cases reported to our knowledge. It is often detected owing to hematuria, and is treated by surgery (for example, total cystectomy), radiation therapy, and chemotherapy; however, the prognosis is extremely poor.Case presentationAn 83-year-old Japanese man underwent cystoscopy for postoperative follow-up of urothelial carcinoma of the bladder, which revealed a 2-cm nodular tumor on the right wall. He had a history of abdominal aortic aneurysm and hypertension, and had been smoking 15 cigarettes per day for 45 years. Seven years previously, the patient underwent transurethral resection of bladder tumor for a 5-cm tumor on the right wall of the bladder. The histopathological diagnosis was urothelial carcinoma. No recurrence had been detected since then. Transurethral resection of bladder tumor was performed, and the histopathological diagnosis was cystosarcoma. Because of his advanced age, we decided that it would be difficult to perform total cystectomy. We therefore performed a second transurethral resection of bladder tumor and found no residual tumor. At 29 months after surgery, the patient remains alive without recurrence.ConclusionBladder osteosarcoma has a poor prognosis. However, our case was detected early, and treatment with transurethral resection of bladder tumor alone resulted in long-term survival without recurrence.

Fatal Aortoduodenal Fistula Caused by a Ruptured Abdominal Aortic Aneurysm - a Case Report

ABSTRACT Introduction: Ruptured abdominal aortic aneurysm (AAA) has a high mortality, even when the patients reach the hospital in time and the intervention is expeditious. Case presentation: We present the case of a 66-year-old male patient, with a known history of AAA, presenting to the emergency room in a state of hypovolemic shock due to massive bleeding in the upper and lower gastrointestinal tract and acute abdominal pain, which presented an abrupt onset one hour before presentation. The computed tomography angiography identified an aortoduodenal fistula with a trajectory toward the D3 segment of the duodenum, as well as a common iliac artery occlusion and extensive atherosclerotic stigmas. The patient was rushed to the operation room where he was resuscitated with intravenous fluids, two units of packed red blood cells, and hemostatic agents. The bleeding was stopped by clamping the aorta above the aneurysm. The duodenum was sutured, and the aorta was reconstructed with an aortobifemoral graft. Unfortunately, even though intensive care procedures continued for a few hours after surgery, all therapeutic efforts failed and the patient had succumbed.

Postoperative endoleak after EVAR and effective endovascular reintervention. The case of the 64-year old male with abdominal aortic aneurysm with concomitant common iliac artery aneurysm.

Endovascular aneurysm repair (EVAR) is a widely accepted alternative for open surgical repair (OSR) in the treatment of an abdominal aortic aneurysm (AAA). Metaanalyses of randomized controlled trials revealed significantly lower short-term mortality after EVAR procedure than OSR. From a technical point of view, proper sizing and selection of the stent-graft is very important. Most instructions for use (IFUs) of the current endografts recommend 10-20% oversizing concerning the preoperative aortic diameter. It can prevent endoleaks or subsequent complications such as displacement of the leg to the abdominal aneurysmal sac. In this paper, we present a case of a 64-year old male with a history of abdominal aortic aneurysm with concomitant common iliac artery (CIA) aneurysm. The patient underwent endovascular implantation of bifurcated stent-graft with extension to the right common iliac artery. He was admitted to the Department of Vascular Surgery due to increasing pain in the right-lower abdomen. The analysis of the imaging examination and the symptoms of an increasing lower limb ischaemia caused by deformation of the stent-graft allowed to decide for an endovascular intervention involving the implantation of the iliac side branch device (IBD). Postoperative angiography confirmed the correct location of the IBD with proper blood flow. After five days the patient was discharged home.

Acute Thromboembolism from Trauma in a Patient with Abdominal Aortic Aneurysm.

Case PresentationA 64-year-old man with a history of a 5.5-centimeter (cm) abdominal aortic aneurysm (AAA) presented to the emergency department (ED) complaining of severe back pain after climbing over a fence and falling a distance of eight feet. Prior to arrival, the prehospital paramedics reported that the patient did not have palpable pulses in either lower extremity. The initial physical examination in the ED was significant for absent dorsalis pedis pulses bilaterally as well as absent posterior tibialis pulses bilaterally and cold, insensate lower extremities. Point-of-care ultrasound identified an approximate 7-cm infrarenal AAA with a mural thrombus present. After receiving several computed tomography (CT) studies including CT head without contrast and CT angiography of the chest, abdomen and pelvis, the patient was diagnosed with acute thrombosis of AAA and associated thromboembolic occlusion of both his right and left distal iliac vessels causing bilateral acute limb ischemia. He immediately received unfractionated heparin and was admitted to the hospital for embolectomy and intra-arterial tissue plasminogen activator.DiscussionAcute thrombosis of AAA and subsequent thromboembolic events are a rare but significant complication that can occur in patients with a history of AAA. Thromboembolic events may occur spontaneously or in the setting of blunt abdominal trauma. Common presenting signs and symptoms include distal limb ischemia and absent femoral pulses. Timely management and recognition of this rare complication is vital as this condition can ultimately result in limb loss or death if not treated in a timely manner. Heparinization after confirmation of non-ruptured AAA as well as vascular surgery, and therapeutic and vascular interventional radiology consultations are key steps that should be taken to decrease patient morbidity and mortality.

An Adrenal Myelolipoma With Hemorrhage

An 80-year-old man with a history of abdominal aortic aneurysm presented after a large left adrenal mass was found on surveillance ultrasonography. A subsequent abdominal and pelvic computed tomography (CT) scan revealed a 15-cm heterogeneous, round mass with a small internal fat component (Fig. 1A) with evidence of focal active extravasation of contrast within the mass consistent with active hemorrhage (Fig. 1B). On his CT 4 years prior, the adrenal lesion measured 4.9 cm and had areas of macroscopic fat and punctate calcifications consistent with a myelolipoma.

Validation of natural language processing to determine the presence and size of abdominal aortic aneurysms in a large integrated health system

Previous studies of the natural history of abdominal aortic aneurysms (AAAs) have been limited by small cohort sizes or heterogeneous analyses of pooled data. By quickly and efficiently extracting imaging data from the health records, natural language processing (NLP) has the potential to substantially improve how we study and care for patients with AAAs. The aim of the present study was to test the ability of an NLP tool to accurately identify the presence or absence of AAAs and detect the maximal abdominal aortic diameter in a large dataset of imaging study reports. Relevant imaging study reports (n= 230,660) from 2003 to 2017 were obtained for 32,778 patients followed up in a prospective aneurysm surveillance registry within a large, diverse, integrated healthcare system. A commercially available NLP algorithm was used to assess the presence of AAAs, confirm the absence of AAAs, and extract the maximal diameter of the abdominal aorta, if stated. A blinded expert manual review of 18,000 randomly selected imaging reports was used as the reference standard. The positive predictive value (PPV or precision), sensitivity (recall), and the kappa statistics were calculated. Of the randomly selected 18,000 studies that underwent expert manual review, 48.7% were positive for AAAs. In confirming the presence of an AAA, the interrater reliability of the NLP compared with the expert review showed a kappa value of 0.84 (95% confidence interval [CI], 0.83-0.85), with a PPV of 95% and sensitivity of 88.5%. The NLP algorithm showed similar results for confirming the absence of an AAA, with a kappa of 0.79 (95% CI, 0.799-0.80), PPV of 77.7%, and sensitivity of 91.9%. The kappa, PPV, and sensitivity of the NLP for correctly identifying the maximal aortic diameter was 0.88 (95% CI, 0.87-0.89), 88.8%, and 88.2% respectively. The use of NLP software can accurately analyze large volumes of radiology report data to detect AAA disease and assemble a contemporary aortic diameter-based cohort of patients for longitudinal analysis to guide surveillance, medical management, and operative decision making. It can also potentially be used to identify from the electronic medical records pre- and postoperative AAA patients "lost to follow-up," leverage human resources engaged in the ongoing surveillance of patients with AAAs, and facilitate the construction and implementation of AAA screening programs.

Acute Nonsuppurative Sialadenitis After Contrast Material Administration For Computed Tomography Angiography

Introduction: By the use of iodine-containing intravenous contrast agents, sialadenitis rarely occurs with a sudden expansion of the salivary glands. Its pathogenesis is uncertain, but it appears to be the result of an idiosyncratic reaction or accumulation of iodine in the ductal system of the salivary gland. In this article, we aimed to present a case of contrast-induced sialadenitis after an iodine-containing contrast agent. Case Presentation: A sixty-six-year-old male with a history of abdominal aortic aneurysm was referred for CT angiography. The patient had referred to emergency service with mildly tenderness, pain, and swelling in the bilateral submandibular region. Physical examination also revealed mildly enlarged bilateral submandibular glands, with no fever. There was no erythema, ulcer, and no symptom in both oral and oropharyngeal mucosa. The US performed bilateral diffuse homogeneous expansion of the submandibular salivary glands. In the light of clinical and radiological findings, contrast-induced non-suppurative sialadenitis was considered. Conclusion: Non-suppurative sialadenitis is a rare adverse effect of contrast material administration, which true incidence is unknown. Chronic kidney failure and repeated dose of contrast material are risk factors for this complication. We think that this adverse effect deserves more attention, and follow-up, and prevention for recurrence because its long-term importance is unknown yet.

Abdominal Aortic Aneurysms No Not Develop More Aggressively Among Patients With a Positive Family History of the Disease

Introduction: It is well known that a family history of Abdominal Aortic Aneurysm (AAA) strongly increases the risk of developing AAA, but it is still unknown whether familial AAAs develop differently than non-familial AAAs. Objectives: To investigate whether familial AAAs develop more aggressively than non-familial AAAs by looking at the growth rate, risk of surgery and rupture, as well as the size of the aneurysm at the time of diagnosis and the patient’s age at the time of operation, rupture and diagnosis. Design: Observational retrospective longitudinal study. Materials and Methods: 318 patients with AAA diagnosed between 1996-2008 in Jutland, Denmark with information on family history of AAA, the diameter of AAA throughout follow-up, surgery, ruptures, comorbidity, smoking, and use of medication. Patients with and without a family history of AAA were compared regarding mean age at diagnosis and surgery, the diameter of AAA at diagnosis, risk of surgery and rupture as well as comorbidity and use of medication. Mean growth rates were compared between the two groups and a mixed-effects model was fitted to control for confounders. Results: We included 93 patients with and 225 without a family history of AAA. Patients with a family history of AAA ere significantly younger than patients with no family history of the disease (69.8 vs. 72.4 years, p=0.032), but we found no significant differences in age at operation (72.2 vs. 70.6, p=0.204), the proportion of patients experiencing rupture (16.0 vs. 10.6%, p=0.226) or undergoing surgery (78.2% vs. 81.7%, p=0.484). We found no significant difference in growth rates between the two groups; 5.25 mm/year for patients with positive family history and 6.19 mm/year for patients with no family history of AAA (p=0.490). Conclusions: We found no evidence to suggest that AAA develops more aggressively in patients with a positive family history of the disease.

Abstract P248: Smoking, Smoking Cessation, and Risk of Abdominal Aortic Aneurysm: The Atherosclerosis Risk in Communities Study

Introduction: Smoking is the strongest risk factor for abdominal aortic aneurysm (AAA), and male ever smokers who are recommended for one-time screening for AAA with ultrasonography at age of 65 to 75 years. However, the proportion of eligible individuals who receive this screening remains small (~1%). Few studies have evaluated the association of key smoking parameters with incident AAA by sex. Methods: In 14,889 ARIC participants free of a history of AAA at baseline (1987-89), we quantified the associations of smoking parameters (pack-years, duration, and intensity [pack/day]) with incident AAA (hospitalizations with AAA diagnosis [ICD code: 441.3, 441.4, 38.44, 39.71] or a death certificate ICD code: 441.3, 441.4, I71.3, I71.4) using Cox models. Years since quitting in former smokers were explored as time-varying variables. Results: Over a median follow-up of 20 years, there were 567 cases of AAA. The incident rate of AAA was 5.98 per 1,000 person-years in male current smokers and 2.65 per 1,000 person-years in female current smokers. Pack-years was significantly associated with incident AAA (HR 7.31 [95% CI 5.48-9.74] for those smoked ≥40 pack-years vs. never smokers) and the association was stronger in women than men (8.53 [5.03-14.45] vs. 5.97 [4.21-8.47], p-for-interaction =0.02). Both smoking duration and intensity showed significant associations with AAA. Smoking cessation demonstrated a graded association with lower risk of AAA in both sexes, but significantly increased risk lasted longer in men (2.16 [1.39-3.36] in 30-&lt;40 years after cessation) than in women (1.84 [0.76-4.46] in 20-&lt;30 years after cessation) (Table). Conclusions: All smoking parameters tested consistently show significant associations with incident AAA in both sexes. After cessation, the residual risk lasted at least 40 years in men and 20 years in women. Our results further emphasize the importance of smoking prevention and early cessation for preventing AAA and the potential need of AAA screening in female current smokers and recent quitters.

Prevalence and Natural History of Abdominal Aortic Aneurysm Among Men Invited to a Population Based Screening Program

Introduction: Population based screening for AAA reduces aneurysm-related mortality and all-cause mortality. The AAA screening program in Stockholm started 2010, inviting men born 1945 to a one-time examination with ultrasound. The efficacy of a screening programs depends not only on the participations-rate but on the quality of the surveillance program and the results after surgery. The aim of this study was to describe the natural history for men participating in screening, including drop-out rates and mortality in surveillance and results after surgery. In addition we present AAA treatment rates and ruptures among non-participants in our county. Methods: A population based screening program inviting 65-year-old men started in 2010 in Stockholm County (2.3 million inhabitants). The screening program is centralized and is administered using a web-based database. Patients' demographics are collected prospectively at the first visit (index) and all surveillance visits are registered. All men diagnosed with AAA 2010-2016 were included (n=662) and compared with a control group (n=237). The time of follow-up was 12-84 months. Medical charts and Swedvasc registry data were analyzed for aortic repair in all men born 1945-1951. Results: The participation in screening was 78%, the AAA-prevalence was 1.2% (n=672). Treatment rates correlated with high aortic size index (ASI) and aortic diameter, 22,5 % of men with an AAA detected in screening were treated for intact AAA. The 30-day mortality for the 152 treated men was 0%. During the study period, 35 men in surveillance died (5.2 %), non-AAA related causes (82,9 %) dominated, followed by unknown causes among 4 men (11.4%), and 2 (5.7%) possibly AAA related deaths. The rupture rate in participants vs non-participants was lower (0.0036% vs 0.096%). Conclusion: The high participation rate and low drop-out rate confirm acceptability of population based screening. The efficacy of the program is shown by the much higher rupture rate among the non-participating men. Implementing complimentary surveillance methodologies, such as ASI, should be investigated further. Disclosure: Nothing to disclose

PC176. Delayed Renal Artery Revascularization Can Be Associated With Complete Renal Recovery and Freedom From Dialysis

Acute renal ischemia can progress to irreversible loss of renal function if untreated and is considered time sensitive. Increased duration of warm ischemic time is associated with diminished long-term renal recovery. The usefulness of delayed renal artery revascularization (>48 hours) in patients with acute renal failure leading to dialysis dependence is controversial. Clinical case 1 describes a 73-year-old woman with a history of abdominal aortic aneurysm, atrophic left kidney, and right renal artery stent with a baseline creatinine of 2.3 mg/dL had presented with acute on chronic renal failure. She was severely hypertensive and hyperkalemic, with a creatinine of 9 mg/dL. She required urgent hemodialysis. On renal angiography, she was found to have a total occlusion of the right renal artery and deemed end stage renal disease. She presented 2 weeks later with a contained rupture of her abdominal aortic aneurysm. Her computed tomography scan also demonstrated opacification of the mid-right renal artery (Fig 1). She underwent open abdominal aortic aneurysm repair and right renal artery bypass. Upon discharge 12 days later, she was no longer dialysis dependent, making adequate urine, and her creatinine had returned to baseline. Clinical case 2 describes a 48-year-old woman with a history of Takayasus arteritis, prior proximal descending thoracic aorta to infrarenal abdominal aortic bypass and bypass to the left renal artery for mid-aortic syndrome, and atrophic right kidney presented with severe hypertension, fluid overload, and hyperkalemia, and a creatinine of 5.8 mg/dL requiring urgent dialysis. She was anuric and dialysis dependent. Magnetic resonance angiography revealed occlusion of the left renal artery bypass which originated from the aortic bypass graft and collateral filling of the left kidney with differential areas of perfusion (Fig 2). She underwent redo aortic graft to left renal artery bypass 18 days after her initial presentation. Upon discharge, she was no longer dialysis dependent and her creatinine has normalized. Two patients presenting with dialysis dependent acute renal failure underwent delayed renal artery revascularization, greater than 14 days from their presentation. Complete renal recovery with return to baseline renal function was observed in these patients. In select patients, delayed renal artery revascularization (>48 hours of warm ischemic time) is controversial, but can be associated with complete renal recovery and freedom from dialysis.Fig 2Case 2.View Large Image Figure ViewerDownload Hi-res image Download (PPT)