Abdominal Aortic Rupture Research Articles

Abstract Tu019: Single-Cell RNA Sequencing Identifies IFNICs as a Cellular Target for Mitigating the Progression of Abdominal Aortic Aneurysm and Rupture Risk

Introduction: Abdominal aortic aneurysm (AAA) represents a life-threatening condition characterized by medial layer degeneration of the abdominal aorta. Nevertheless, knowledge regarding changes in regulators associated with aortic status remains incomplete. A thorough understanding of cell types and signaling pathways involved in the development and progression of AAAs is essential for the development of medical therapy. Methods and Results: We harvested specimens of the abdominal aorta with different pathological features in Angiotensin II (AngII)-infused ApoE -/- mice, conducted scRNA-seq, identified a unique population of interferon-inducible monocytes/macrophages (IFNICs), which were amply found in the abdominal aortic aneurysms (AAAs). Gene set variation analysis (GSVA) revealed that activation of the cytosolic DNA sensing cGAS-STING and JAK-STAT pathways promoted the secretion of type I interferons in monocytes/macrophages and differentiated them into IFNICs. We generated myeloid cell-specific deletion of Sting1 ( Lyz2 -Cre +/- ; Sting1 flox/flox ) mice and performed bone marrow transplantation and found that myeloid cell-specific deletion of Sting1 or Ifnar1 significantly reduced the incidence of AAA, aortic rupture rate and diameter of the abdominal aorta. Mechanistically, the activated pyroptosis- and inflammation-related signaling pathways, regulated by IRF7 in IFNICs, play critical roles in the developing AAAs. Conclusion: IFNICs is a unique monocyte/macrophage subset implicated in the development of AAAs and aortic rupture.

Proximal sealing in the aortic arch for inner curve disease using the custom Relay scalloped and fenestrated stent graft

ObjectiveThis study aimed to analyze early and midterm results of custom-made proximal scallop and fenestrated stent grafts for thoracic endovascular aortic repair (TEVAR) with a proximal landing zone (PLZ) in the aortic arch. MethodsAll consecutive patients treated with the custom made proximal scalloped and fenestrated Relay stent grafts (Terumo Aortic Bolton Medical Inc.) in 10 Italian centers between January 2014 and December 2022 were included. The primary end points were technical success, incidence of intraoperative major adverse events, deployment accuracy, and rate of early neurological complications, endoleaks (ELs) and retrograde aortic dissection. ResultsDuring the study period, 49 patients received TEVAR with Relay custom-made endograft in Italy were enrolled. The median patient age was 70.1 years (interquartile range, 23-86 years) and 65.3% were male. The indication for treatment was atherosclerotic aneurysms in 59.2% of cases and penetrating aortic ulcer in 22.4%. The endograft configuration was proximal fenestration in 55.1% and scallop in 44.9%. The proximal landing zone was zone 0 in 25 cases (51%), zone 1 in 14 cases (28.6%), and zone 2 in 10 cases (20.4%). The supra-aortic debranching procedures were 38 (77.5%). Technical success was 97.9% (48/49) owing to one case (2.0%) of inaccurate deployment. Intraoperatively, one (2.0%) type Ia and one (2.0%) type III EL were detected. There were no cases of in-hospital mortality, major adverse events, or retrograde dissection. Three minor strokes (6.1%) (National Institutes of Health Stroke Scale score of ≤4) were observed. At a mean follow-up time of 36.3 ± 21.3 months the rate of types I to III ELs and reintervention was 4.1%, respectively. Four patients (8.2%) died during the follow-up period, one (2.1%) from abdominal aortic rupture and three (6.1%) from nonaortic causes. ConclusionsOur early and midterm outcomes suggest that scalloped and fenestrated TEVAR may provide an acceptable alternative treatment option for aortic arch pathologies. Large-scale studies are needed to assess the long-term durability of this technique.

Single-cell RNA sequencing identifies IFNICs as a cellular target for mitigating the progression of abdominal aortic aneurysm and rupture risk.

Abdominal aortic aneurysm (AAA) represents a life-threatening condition characterized by medial layer degeneration of the abdominal aorta. Nevertheless, knowledge regarding changes in regulators associated with aortic status remains incomplete. A thorough understanding of cell types and signaling pathways involved in the development and progression of AAAs is essential for the development of medical therapy. We harvested specimens of the abdominal aorta with different pathological features in Angiotensin II (AngII)-infused ApoE-/- mice, conducted scRNA-seq, identified a unique population of interferon-inducible monocytes/macrophages (IFNICs), which were amply found in the abdominal aortic aneurysms (AAAs). Gene set variation analysis (GSVA) revealed that activation of the cytosolic DNA sensing cGAS-STING and JAK-STAT pathways promoted the secretion of type I interferons in monocytes/macrophages and differentiated them into IFNICs. We generated myeloid cell-specific deletion of Sting1 (Lyz2-Cre+/-; Sting1flox/flox) mice and performed bone marrow transplantation and found that myeloid cell-specific deletion of Sting1 or Ifnar1 significantly reduced the incidence of AAA, aortic rupture rate and diameter of the abdominal aorta. Mechanistically, the activated pyroptosis- and inflammation-related signaling pathways, regulated by IRF7 in IFNICs, play critical roles in the developing AAAs. IFNICs is a unique monocyte/macrophage subset implicated in the development of AAAs and aortic rupture.

Emergency Treatment of Ruptured Abdominal Aneurysm

Introduction: Abdominal aneurysm is considered a formidable pathological condition that requires prompt treatment. Its progressive increase leads to rupture and massive internal bleeding, which requires the most effective medical care. However, despite the improvement in medical equipment and postoperative care, mortality due to ruptured abdominal aneurysms is still close to 50%, which is primarily related to the severity of the pathology and open surgical intervention.
 Materials and Methods: 46 patients diagnosed with rupture of the abdominal aorta took part in the study. Selection criteria were a history of abdominal aortic rupture, conservative/operative treatment for the disease, and absence of other complications (acute renal failure, liver infarction) that could affect the results of the study.
 Results: Since January 2018, 46 cases of ruptured AAAs have been diagnosed. In all forty-six cases, surgical intervention was used: open surgery or endovascular technique. All 100% of patients had a previous history of diagnosed abdominal aortic aneurysm, for which they underwent periodic ultrasound examinations.
 As a result of the study, it was found that endovascular aortic aneurysm correction is the optimal method for both planned and emergency treatment of aortic aneurysm and its rupture. According to the Cochrane Specialized Register, it was established that endovascular repair is associated with a reduction in early morbidity and mortality after abdominal aneurysm, compared with other methods of surgical treatment. Furthermore, the study found that, unlike open surgery methods, endovascular techniques are associated with a lower risk of complications in the form of intestinal ischemia.
 Conclusions: Inferior quality studies and lack of information limit the conclusions of this review. From the statistical data shown in this paper, it can be concluded that there is a difference between endovascular and open methods of treatment of abdominal aortic aneurysm rupture. Mortality within the first 30 days after treatment and short-term complications are significantly lower in patients using EVAR. Systemic complications are also more prevalent in patients who were prescribed open surgical treatment.

Spontaneous abdominal aortic rupture in a patient with SARS-CoV-2 infection

Spontaneous abdominal aortic rupture in a patient with SARS-CoV-2 infection

Evidence for a protective role of Protein Disulfide Isomerase-A1 against aortic dissection

Background and aimsRedox signaling is involved in the pathophysiology of aortic aneurysm/dissection. Protein Disulfide Isomerases and its prototype PDIA1 are thiol redox chaperones mainly from endoplasmic reticulum (ER), while PDIA1 cell surface pool redox-regulates thrombosis, cytoskeleton remodeling and integrin activation, which are mechanisms involved in aortic disease. Here we investigate the roles of PDIA1 in aortic dissection. MethodsInitially, we assessed the outcome of aortic aneurysm/dissection in transgenic PDIA1-overexpressing FVB mice using a model of 28-day exposure to lysyl oxidase inhibitor BAPN plus angiotensin-II infusion. In a second protocol, we assessed the effects of PDIA1 inhibitor isoquercetin (IQ) against aortic dissection in C57BL/6 mice exposed to BAPN for 28 days. ResultsTransgenic PDIA1 overexpression associated with ca. 50% (p = 0.022) decrease (vs.wild-type) in mortality due to abdominal aortic rupture and protected against elastic fiber breaks in thoracic aorta. Conversely, exposure of mice to IQ increased thoracic aorta dissection-related mortality rates, from ca. 18%–50% within 28-days (p = 0.019); elastic fiber disruption and collagen deposition were also enhanced. The structurally-related compound diosmetin, which does not inhibit PDI, had negligible effects. In parallel, stretch-tension curves indicated that IQ amplified a ductile-type of biomechanical failure vs. control or BAPN-exposed mice aortas. IQ-induced effects seemed unassociated with nonspecific antioxidant effects or ER stress. In both models, echocardiographic analysis of surviving mice suggested that aortic rupture was dissociated from progressive dilatation. ConclusionsOur data indicate a protective role of PDIA1 against aortic dissection/rupture and potentially uncovers a novel integrative mechanism coupling redox and biomechanical homeostasis in vascular remodeling.

Efficacy and safety of robotic-assisted versus median sternotomy for cardiac surgery: results from a university affiliated hospital.

We aimed to report the experience of robotic-assisted cardiac surgery (RACS) using the Da Vinci robotic surgical system, meanwhile its efficacy and safety was also evaluated by comparing with traditional open-heart surgery (TOHS), thus to provide evidence for a broader application of RACS in clinical practice. From July 2017 to May 2022, a total of 255 patients who underwent cardiac surgery assisted by Da Vinci robotic surgery system in the First Affiliated Hospital of Anhui Medical University, which included 134 males with an average age of 52.6±6.3 years and 121 females with an average age of 51.8±5.4 years. They were defined as the RACS group. By searching the hospital's electronic medical record information system, 736 patients with the same disease types who underwent median sternotomy and had complete data in the same period were selected as the TOHS group. Intra- and postoperative clinical results of the both groups were compared, and we focused the following indices including surgery time, reoperation rate for postoperative bleeding, length of intensive care unit (ICU) stay, postoperative hospitalization day, the number of died and withdrawing treatments, and the time of patients back to normal daily activities after discharge. In RACS group, 2 patients were scheduled to undergo mitral valvuloplasty (MVP), but they had to change to mitral valve replacement (MVR) due to unsatisfactory results; furthermore, 1 patient who received atrial septal defect (ASD) repair experienced abdominal hemorrhage because a rupture of abdominal aorta which were induced by the femoral arterial cannulation, and this patient eventually died of invalid rescue. As for the comparison of clinical results between both groups, there were no significant statistical differences in reoperation rate for postoperative bleeding, and the number of died and withdrawing treatments between both groups. However, length ICU stay, postoperative hospitalization day, and the time of patients back to normal daily activities after discharge was lower in RACS group in addition to the surgery time. Compared with TOHS, RACS is safe and effective in clinical and is worthy of promotion in an appropriate place.

Surgical outcomes of thoracic endovascular aortic repair for retrograde Stanford type a dissection.

The optimal indications and contraindications for thoracic endovascular aortic repair of retrograde Stanford type A acute aortic dissection (R-AAAD) are not well known. The goal of this study was to determine the outcomes of thoracic endovascular aortic repair for R-AAAD at our institution and to discuss optimal indications. The medical records of 359 patients admitted to our institution for R-AAAD between December 2016 and December 2022 were reviewed, and 83 patients were finally diagnosed with R-AAAD. We selected thoracic endovascular aortic repair as an alternative, considering the anatomy of aortic dissection and the risk to patients undergoing open surgery. Nineteen patients underwent thoracic endovascular aortic repair for R-AAAD. No in-hospital deaths or neurologic complications occurred. A type Ia endoleak was detected in 1 patient. All other primary entries were successfully closed. All dissection-related complications, such as cardiac tamponade, malperfusion distal to the primary entry and abdominal aortic rupture, were resolved. One patient required open conversion for intimal injury at the proximal edge of the stent graft; all other ascending false lumens were completely thrombosed and contracted at discharge. During the follow-up period, no aortic-related deaths or aortic events proximal to the stent graft occurred. The indications for thoracic endovascular aortic repair were expanded to low-risk and emergency cases at our institution. The early- and midterm outcomes of thoracic endovascular aortic repair for R-AAAD were acceptable. Further long-term follow-up is required.

A sudden death, an aortic rupture, and an unexpected cause: a report about suspected child abuse.

All unexpected deaths of children require an autopsy to determine the cause of death. In cases of aortic rupture, the immediate cause of death is easily identified at autopsy. Although the majority of aortic ruptures are caused by high-energy trauma, other causes should not be missed.We present and discuss the case of a 29-month-old child who died suddenly at home. Her recent medical history and the ecchymotic lesions observed on external examination of the body appeared potentially suspicious of physical abuse. The autopsy concluded that death was due to complete rupture of the abdominal aorta with associated vertebral disjunction. At first glance, the overall forensic picture could suggest a traumatic death. However, careful inspection of the retroperitoneum revealed a discrete atypical mass of infiltrative tissue within the hematoma. Histopathological examinations confirmed tumor proliferation of the soft tissues, triggering vascular and spinal injuries. Other paraneoplastic elements or metastases were ultimately revealed (orbital and subcutaneous). Overall, this was a rare and fatal case of abdominal aortic rupture induced by tumors. Due to the mechanisms and the forces needed to cause vertebral dislocations and aortic rupture, the combination of the two is highly suggestive of child abuse when an accidental traumatic history is absent or inconsistent with the injuries. Nevertheless, this case illustrates the importance of a systematic and rigorous forensic examination, rather than ignoring other possible diagnoses.

Effect of Telmisartan on the Peak Wall Stress and Peak Wall Rupture Index of Small Abdominal Aortic Aneurysms: An Exploratory Analysis of the TEDY Trial

This study was an unplanned exploratory analysis of a subset of participants from the Telmisartan in the Management of Abdominal Aortic Aneurysm (TEDY) trial. It aimed to assess the efficacy of the angiotensin 1 receptor blocker telmisartan in reducing abdominal aortic aneurysm (AAA) peak wall stress (PWS) and peak wall rupture index (PWRI) among individuals with small AAAs. Participants with AAAs measuring 35 - 49 mm in maximum diameter were randomised to receive telmisartan 40 mg or identical placebo in the TEDY trial. Participants who had computed tomography angiography performed at entry and at least one other time point during the trial (12 or 24 months) were included in the current study. Orthogonal AAA diameter, PWS, and PWRI were measured using previously validated methods. The annual change in PWS and PWRI from baseline was compared between participants allocated telmisartan or placebo using linear mixed effects models. These models were either unadjusted or adjusted for risk factors that were different in the groups at entry (p < .100) or systolic blood pressure (SBP) at one year. Of the 207 participants recruited to TEDY, 124 were eligible for inclusion in this study. This study included 65 and 59 participants from the telmisartan and placebo groups, respectively. The PWS and PWRI were not significantly different in the two groups at baseline. Participants allocated telmisartan had a slower annual increase in PWS (-4.19; 95% CI -8.24, -0.14 kPa/year; p= .043) and PWRI (-0.014; 95% CI -0.026, -0.001; p= .032) compared with those allocated placebo after adjusting for risk factors. After adjustment for SBP at one year, telmisartan did not significantly reduce annual increases in PWS or PWRI. The findings of this study suggest that telmisartan limits the rate of increase in PWS and PWRI of small AAAs by reducing blood pressure.

Single centre experience with Excluder® stent graft; 17-year outcome.

BackgroundEndovascular abdominal aortic aneurysm repair (EVAR) has become a mainstay of abdominal aorta aneurysm treatment. Long term follow-up on specific stent grafts is needed.Patients and methodsThis study included 123 patients (104 men; mean age 73.0 years, range 51–89) with abdominal aorta aneurysm, treated with Excluder® stent graft between October 2002 and June 2008. Periprocedural and follow-up data were retrieved by reviewing the records of our institution, while time and cause of death were retrieved from the National Institute of Public Health. If an abdominal aortic aneurysm rupture was listed as the cause of death, records were retrieved from the institution that issued the death certificate. Our primary goal was to assess the primary technical success rate, type 1 and type 2 endoleak, reintervention free survival, 30-day mortality, the overall survival and aneurysm rupture-free survival.ResultsThe median follow-up was 9.7 years (interquartile range, 4.6–13.8). The primary technical success was 98.4% and the 30-day mortality accounted for 0.8%. Secondary procedures were performed in 29 (23.6%) patients during the follow-up period. The one-, five-, ten-, fifteen- and seventeen-year overall survival accounted for 94.3%, 74.0%, 47.2%, 35.8% and 35.8%, while the aneurysm-related survival was 98.4%, 96.3%, 92.6%, 92.6%, 92.6%. In seven (5.7%) patients, abdominal aortic rupture was found as the primary cause of death during follow-up.ConclusionsOur data showed that EVAR with Excluder® stent graft offers good long-term results. More than 75% of patients can be treated completely percutaneously. Late ruptures do occur in the first ten years, raising awareness about regular medical controls.

Significant vascular complications in percutaneous axillary intra-aortic balloon pump

ObjectiveAxillary Intra-aortic balloon pump (IABP) has been increasingly utilized for hemodynamic support in heart failure patients. Vascular complications associated with axillary IABP such as dissection or rupture are relatively rare but not negligible that could negatively affect clinical outcomes. We summarized our experiences. MethodsThis is a retrospective study reviewing of all patients receiving an axillary IABP between June 2016 and November 2020. A total of 199 patients underwent percutaneous axillary IABP placement. 6 patients (6/199, 3.0%) were complicated with arterial/aortic dissection or rupture during the procedures or the course of treatment. We described their clinical presentations and outcomes. ResultsVascular complications included acute type A aortic dissection in 2 patients, descending aortic rupture in 1 patient, abdominal aortic rupture along with type B aortic dissection in 1 patient, and the localized left subclavian artery dissection in 2 patient. 2 type A aortic dissection cases were surgically treated: 1 with emergent left ventricle assist device and ascending aorta replacement, the other with emergent left ventricle assist device. Emergent endovascular treatment was successfully performed in 2 aortic rupture cases. The left subclavian artery dissection cases were managed medically. The postoperative/treatment course was uneventful in all patients. ConclusionPercutaneous axillary IABP therapy can cause significant vascular complications. Early diagnosis and prompt treatment would be the key to improve the clinical outcomesv.

Resveratrol against lung injury in an ischemia/reperfusion model of abdominal aortic rupture.

Background The aim of this study was to examine the effects on the lungs of ischemia/reperfusion injury in a ruptured abdominal aortic aneurysm model in rats and to investigate the potential protective effects of resveratrol. Methods Thirty-two male Sprague-Dawley rats were randomly divided into four groups: control, ischemia/reperfusion, sham (ischemia/ reperfusion + solvent/dimethyl sulfoxide), and ischemia/reperfusion + resveratrol. In the groups subjected to ischemia/reperfusion, following 60-min shock to the abdominal aorta, vascular clamps were attached from the levels of the infrarenal and iliac bifurcation. A total of 60-min ischemia was applied, followed by 120-min reperfusion. In the ischemia/ reperfusion + resveratrol group, intraperitoneal 10 mg/kg resveratrol was administered 15 min before ischemia and immediately after reperfusion. Malondialdehyde, glutathione, and catalase levels were analyzed and histopathological examination of the lung tissues was performed. Results Malondialdehyde levels increased in the ischemia/reperfusion and ischemia/reperfusion + dimethyl sulfoxide groups, compared to the control group, while catalase levels decreased, and no significant difference was observed in the glutathione levels. Malondialdehyde levels decreased with the administration of resveratrol, while glutathione levels increased, and catalase levels remained unchanged. The increased inflammation in interstitial spaces, thickening in the alveolar septal walls, increased numbers of cleaved caspase-3 apoptotic pneumocytes, and increased histopathological lung damage scores observed in the ischemia/reperfusion and ischemia/reperfusion + dimethyl sulfoxide groups improved with the application of resveratrol. Conclusion These findings suggest that resveratrol may exhibit a protective effect in preventing acute lung injury developing due to ischemia/reperfusion in ruptured abdominal aortic aneurysm surgery by reducing oxidative damage.

A Case of Abdominal Aortic Rupture Treated by Chimney EVAR

腹部大動脈修復部位の感染破綻により大動脈破裂を発症した症例に対して，Chimney techniqueを用いて止血術を行い救命した症例を経験したので報告する．症例は62歳，女性．下行結腸癌術後リンパ節転移に対して4回の手術歴があり，4回目の術中に腹部大動脈を損傷し血管修復術と左腎臓摘出術を行った．術後，直腸吻合部の縫合不全による腹膜炎を発症し，大動脈修復部位の感染にひき続いて大動脈破裂を発症した．破裂部位は左腎動脈レベルの近傍であった．大動脈破裂症例であること，腹腔内や後腹膜に高度の癒着が予想され開腹による直接止血は困難であることを考慮し，ステントグラフト留置にはややネック長は短かったが，Chimney techniqueを用いて止血術を行った．術後，endoleakや腎機能悪化を認めず，救命することができた．大動脈破裂症例に対するChimney techniqueは緊急時の治療選択の1つとして有用と考えられた．

Endovascular treatment of abdominal aortic rupture after percutaneous lithotripsy.

Endovascular treatment of abdominal aortic rupture after percutaneous lithotripsy.

Endovascular Repair for Abdominal Aortic Rupture Caused by Periaortic Mantle Cell Lymphoma.

A 72-year-old man was referred to our hospital for the suspicion of ruptured abdominal aortic aneurysm. Before admission, he was suspected of having a malignant lymphoma and underwent excisional biopsy in his right groin. A contrast enhanced computed tomography scan revealed a massive retroperitoneal hematoma with an extravasation arising from the infrarenal abdominal aorta coexisting with an extensive retroperitoneal mass surrounding the aorta. An emergency endovascular aneurysm repair was performed and the postoperative course was uneventful. After the treatment, histological examination of the previous biopsy confirmed the diagnosis of mantle cell lymphoma.

Successful emergency endovascular aortic repair for intratumoral hemorrhage in extensive retroperitoneal mass of testicular origin

BackgroundMetastatic germ cell cancer of the testis is characterized by favorable prognosis since effective treatment methods are available even in cases of extensive disease. Retroperitoneal masses frequently encroach major blood vessels requiring a vascular intervention usually performed in association with the post-chemotherapy retroperitoneal lymph node dissection (RPLND). Reported clinical case describes a successful pre-treatment endovascular surgery for abdominal aortic rupture allowing for full-dose systemic chemotherapy administration, and subsequent radical surgical intervention at primary tumor site as well as metastatic retroperitoneal lymph node dissection including the reconstruction of inferior caval vein.Case presentationPatient presented with left-sided testicular tumor and voluminous retroperitoneal mass with vascular involvement. Soon after the patient had been admitted for the first cycle of cisplatin-based chemotherapy, computed tomographic angiography (CTA) revealed a dorsal aortic wall rupture with active extravasation and irregular pseudoaneurysmatic dilatation of the aorta below the leak area. Retroperitoneal intratumoral hemorrhage associated with the bilateral iliac venous thrombosis required an endovascular repair procedure of infrarenal abdominal aorta.ConclusionsFollowing the successful endovascular aortic repair 3 cycles of BEP (bleomycin, etoposide, cisplatin) regimen were administered with subsequent delayed left radical orchiectomy and RPLND associated with vena cava inferior (VCI) resection. Reconstruction of VCI was originally not deemed necessary as collateral blood flow appeared sufficient, however, intraoperative complications resulted in the need for unilateral VCI reconstruction, using the interposed bypass between right common iliac vein and infrarenal segment of VCI. Histopathologic examination of the attained specimen detected no vital cancer structures. The patient remains disease-free 18 months after the RPLND.

Endovascular Aortic Repair under Extracorporeal Cardiac Support in a Patient with an Abdominal Aortic Aneurysm Impending Rupture and Aortic Stenosis: A Case Report.

Aortic stenosis is a serious valvular disease that increases the risk of cardiac arrest and/or cardiogenic shock during noncardiac surgery. A 93-year-old woman with an abdominal aortic aneurysm impending rupture and aortic stenosis underwent endovascular abdominal aortic aneurysm repair. During surgery, the patient presented with ventricular tachycardia. Due to on-going cardiogenic shock, we did a direct cannulation into the right axillary artery for the immediate establishment of venoarterial extracorporeal membrane oxygenation. The endovascular treatment of the abdominal aortic aneurysm was completed according to the standard procedure. The patient recovered without any complications, including heart failure or neurological dysfunction.

Пути улучшения результатов лечения разрыва аневризмы брюшной аорты

Пути улучшения результатов лечения разрыва аневризмы брюшной аорты

Congenital left ventricular diverticulum in an asymptomatic patient: multi-modal evaluation

Congenital left ventricular diverticula are rare cardiac malformations. In our case a diverticular apical lesion of the left ventricle was accidentally found on a thoracic CT scan, acutely performed to rule out abdominal aortic rupture.