Roderick T.A. Chalmers

Abdominal Aortic Aneurysm Growth Predicted by Uptake of Ultrasmall Superparamagnetic Particles of Iron Oxide A Pilot Study

Background— Abdominal aortic aneurysms are a major cause of death. Prediction of aneurysm expansion and rupture is challenging and currently relies on the simple measure of aneurysm diameter. Using MRI, we aimed to assess whether areas of cellular inflammation correlated with the rate of abdominal aortic aneurysm expansion. Methods and Results— Stable patients (n=29; 27 male; age, 70±5 years) with asymptomatic abdominal aortic aneurysms (4.0 to 6.6 cm) were recruited from a surveillance program and imaged using a 3-T MRI scanner before and 24 to 36 hours after administration of ultrasmall superparamagnetic particles of iron oxide (USPIO). The change in T2* value on T2*-weighted imaging was used to detect accumulation of USPIO within the abdominal aortic aneurysm. Histological examination of aneurysm tissue confirmed colocalization and uptake of USPIO in areas with macrophage infiltration. Patients with distinct mural uptake of USPIO had a 3-fold higher growth rate (n=11, 0.66 cm/y; P=0.020) than those with no (n=6, 0.22 cm/y) or nonspecific USPIO uptake (n=8, 0.24 cm/y) despite having similar aneurysm diameters (5.4±0.6, 5.1±0.5, and 5.0±0.5 cm, respectively; P>0.05). In 1 patient with an inflammatory aneurysm, there was a strong and widespread uptake of USPIO extending beyond the aortic wall. Conclusions— Uptake of USPIO in abdominal aortic aneurysms identifies cellular inflammation and appears to distinguish those patients with more rapidly progressive abdominal aortic aneurysm expansion. This technique holds major promise as a new method of risk-stratifying patients with abdominal aortic aneurysms that extends beyond the simple anatomic measure of aneurysm diameter. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00794092.

Validity of the Glasgow Aneurysm Score and the Hardman Index in predicting outcome after ruptured abdominal aortic aneurysm repair

The Glasgow Aneurysm Score and the Hardman Index have been recommended as predictors of outcome after repair of ruptured abdominal aortic aneurysm (AAA). This study aimed to assess their validities.

Prognostic scoring in ruptured abdominal aortic aneurysm: A prospective evaluation

BACKGROUND Prospective validation of prognostic scoring systems for ruptured abdominal aortic aneurysm (AAA) is lacking. This study assesses the validity of three established risk scores and a new prognostic index. METHOD Patients admitted with ruptured AAA during a 26-month period (August 2002-December 2004) were recruited prospectively. The Glasgow Aneurysm Score (GAS), Hardman Index, Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) scores, and the Edinburgh Ruptured Aneurysm Score (ERAS) were recorded and related to outcome. RESULTS During the study period, 111 patients were admitted with ruptured AAA. Of these, 84 (76%) underwent attempted operative repair and were included in the study; 37 (44%) died after operation. The GAS, Hardman Index, and the ERAS were statistically related to mortality. However, analysis by receiver-operator characteristic curve revealed the ERAS to have an area under the curve (AUC) of 0.72 (95% confidence interval [CI], 0.61-0.83). The vascular (V)-POSSUM and ruptured AAA (RAAA)-POSSUM models had an AUC of 0.70 (95% CI, 0.59-0.82). The Hardman Index and GAS had an AUC of 0.69 (95% CI, 0.57-0.80) and 0.64 (95% CI, 0.52-0.76), respectively. Although the V-POSSUM equation predicted mortality effectively (P = .086), the RAAA-POSSUM derivative demonstrated a significant lack of fit (P = .009). CONCLUSION Prospective validation shows that the Hardman Index, GAS, and V-POSSUM and RAAA-POSSUM scores do not perform well as predictors for death after ruptured AAA. The ERAS accurately stratifies perioperative risk but requires further validation.

MRI using ultrasmall superparamagnetic particles of iron oxide in patients under surveillance for abdominal aortic aneurysms to predict rupture or surgical repair: MRI for abdominal aortic aneurysms to predict rupture or surgery-the MA(3)RS study.

Introduction Population screening for abdominal aortic aneurysms (AAA) halves the associated mortality and has led to the establishment of national screening programmes. Prediction of aneurysm growth and rupture is challenging and currently relies on serial diameter measurements with ultrasound. Recently, a novel MRI-based technique using ultrasmall superparamagnetic particles of iron oxide (USPIO) has demonstrated considerable promise as a method of identifying aneurysm inflammation and expansion. Methods and analysis The MA3RS study is a prospective observational multicentre cohort study of 350 patients with AAA in three centres across Scotland. All participants will undergo MRI with USPIO and aneurysm expansion will be measured over 2 years with CT in addition to standard clinical ultrasound surveillance. The relationship between mural USPIO uptake and subsequent clinical outcomes, including expansion, rupture and repair, will be evaluated and used to determine whether the technique augments standard risk prediction markers. To ensure adequate sensitivity to answer the primary question, we need to observe 130 events (composite of rupture or repair) with an estimated event rate of 41% over 2 years of follow-up. The MA3RS study is currently recruiting and expects to report in 2017. Discussion This is the first study to evaluate the use of USPIO-enhanced MRI to provide additional information to aid risk prediction models in patients with AAA. If successful, this study will lay the foundation for a large randomised controlled trial targeted at applying this technique to determine clinical management. Trial registration number Current Controlled Trials: ISRCTN76413758.

Contemporary results for open repair of suprarenal and type IV thoracoabdominal aortic aneurysms

Endovascular and hybrid procedures are not yet widely established in the management of type IV thoracoabdominal aortic aneurysm (TAAA). Open surgery remains the treatment of choice until the long‐term outcomes of these novel techniques are known.

Natural history of thoraco-abdominal aneurysm in high-risk patients.

INTRODUCTION There is considerable interest in the role of novel endovascular techniques for the treatment of patients with complex aneurysms who are unsuitable for standard interventions. Knowledge of the natural history of these lesions, as well as other co-morbidities, is required in order that these techniques may be applied correctly in this high-risk group. METHOD This study reviews the outcome of patients deemed to be unfit for surgery following assessment under the Scottish National Thoraco-abdominal aneurysm service (TAAA) service (2002-2008). RESULTS Of 216 patients assessed, 89 (41%) patients were considered to be unfit for intervention. The median (interquartile range, IQR) age of patients was 75 (70-80) years and there were 39 men (44%). Median (IQR) aneurysm size was 6 (5.6-7.0) cm. The median (IQR) follow-up time was 12 (7-26) months. There were 49 (55%) deaths during the follow-up period of which 23 (47%) cases were due to ruptured TAAA and 26 (53%) were not aneurysm-related. Comparing patients with aneurysms <6 cm (33 patients) with those aneurysms > or =6 cm (56 patients) there was no difference in aneurysm-related death (p = 0.32) or all-cause mortality (p = 0.147). CONCLUSION Aneurysm-related mortality amongst patients unsuitable for open TAAA surgery is considerable and evolving endovascular techniques may permit intervention in selected patients. However any intervention can only be justified if the patients life expectancy is sufficient to allow benefit to accrue.

Cardiac troponin I predicts outcome after ruptured abdominal aortic aneurysm repair

Cardiac troponin I (cTnI) is a highly sensitive and specific marker for myocardial injury that predicts mortality in patients with acute coronary syndromes. This study examined the relationship between perioperative cTnI levels and clinical outcome in patients with ruptured abdominal aortic aneurysm (AAA).

18F–Sodium Fluoride Uptake in Abdominal Aortic Aneurysms: The SoFIA3 Study

Background Fluorine-18–sodium fluoride (18F-NaF) uptake is a marker of active vascular calcification associated with high-risk atherosclerotic plaque. Objectives In patients with abdominal aortic aneurysm (AAA), the authors assessed whether 18F-NaF positron emission tomography (PET) and computed tomography (CT) predicts AAA growth and clinical outcomes. Methods In prospective case-control (n = 20 per group) and longitudinal cohort (n = 72) studies, patients with AAA (aortic diameter >40 mm) and control subjects (aortic diameter <30 mm) underwent abdominal ultrasound, 18F-NaF PET-CT, CT angiography, and calcium scoring. Clinical endpoints were aneurysm expansion and the composite of AAA repair or rupture. Results Fluorine-18-NaF uptake was increased in AAA compared with nonaneurysmal regions within the same aorta (p = 0.004) and aortas of control subjects (p = 0.023). Histology and micro-PET-CT demonstrated that 18F-NaF uptake localized to areas of aneurysm disease and active calcification. In 72 patients within the longitudinal cohort study (mean age 73 ± 7 years, 85% men, baseline aneurysm diameter 48.8 ± 7.7 mm), there were 19 aneurysm repairs (26.4%) and 3 ruptures (4.2%) after 510 ± 196 days. Aneurysms in the highest tertile of 18F-NaF uptake expanded 2.5× more rapidly than those in the lowest tertile (3.10 [interquartile range (IQR): 2.34 to 5.92 mm/year] vs. 1.24 [IQR: 0.52 to 2.92 mm/year]; p = 0.008) and were nearly 3× as likely to experience AAA repair or rupture (15.3% vs. 5.6%; log-rank p = 0.043). Conclusions Fluorine-18-NaF PET-CT is a novel and promising approach to the identification of disease activity in patients with AAA and is an additive predictor of aneurysm growth and future clinical events. (Sodium Fluoride Imaging of Abdominal Aortic Aneurysms [SoFIA3]; NCT02229006; Magnetic Resonance Imaging [MRI] for Abdominal Aortic Aneurysms to Predict Rupture or Surgery: The MA3RS Trial; ISRCTN76413758)

Successful management of both early and delayed-onset neurological deficit following extent II thoracoabdominal aneurysm repair

INTRODUCTION Delayed-onset paraplegia is an uncommon but devastating complication of thoracoabdominal aneurysm repair. REPORT We report the successful use of repeat cerebrospinal fluid drainage in the management of both immediate- and delayed-onset (21 days) paraplegia in the same patient undergoing open Type II thoracoabdominal aneurysm repair. DISCUSSION Few studies have looked specifically at preventing delayed onset of symptoms. We advocate continued attention to blood pressure management and hydration for the duration of hospital stay and recommend repeat CSF drainage if symptoms occur.

Ruptured thoracoabdominal aneurysm in a 27-year-old with hyper IgE syndrome

Hyperimmunoglobulin E syndrome is a rare primary immunodeficiency disorder defined by high serum immunoglobulin E titers and associated with characteristic infectious, dermatologic, skeletal, and dental abnormalities. We present the case of a 27-year-old man presenting acutely with a ruptured type IV thoracoabdominal aortic aneurysm. He was successfully treated by open operative repair and discharged with long-term prophylactic antibiotics. To our knowledge, this is the first such case reported in the English literature.