Benjamin O. Patterson

Aortic Pathology Determines Midterm Outcome After Endovascular Repair of the Thoracic Aorta Report From the Medtronic Thoracic Endovascular Registry (MOTHER) Database

Background— Endovascular repair of the thoracic aorta has become an increasingly utilized therapy. Although the short-term mortality advantage over open surgery is well documented, late mortality and the impact of presenting pathology on long-term outcomes remain poorly reported. Methods and Results— A database was built from 5 prospective studies and a single institutional series. Rates of perioperative adverse events were calculated, as were midterm death and reintervention rates. Multivariate analysis was performed with the use of logistic regression modeling. Kaplan-Meier survival curves were drawn for midterm outcomes. The database contained 1010 patients: 670 patients with thoracic aortic aneurysm, 195 with chronic type B aortic dissection, and 114 with acute type B aortic dissection. Lower elective mortality was observed in patients with chronic dissections (3%) compared with patients with aneurysms (5%). Multivariate analysis identified age, mode of admission, American Society of Anesthesiologists grade, and pathology as independent predictors of 30-day death (P < 0.05). In the midterm, the all-cause mortality rate was 8, 4.9, and 3.2 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. The rates of aortic-related death were 0.6, 1.2, and 0.4 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. Conclusions— This study indicated that the midterm outcomes of endovascular repair of the thoracic aorta are defined by presenting pathology, associated comorbidities, and mode of admission. Nonaortic mortality is high in the midterm for patients with thoracic aortic aneurysm, and managing modifiable risk factors appears vital. Endovascular repair of the thoracic aorta results in excellent midterm protection from aortic-related mortality, regardless of presenting pathology.Background— Endovascular repair of the thoracic aorta has become an increasingly utilized therapy. Although the short-term mortality advantage over open surgery is well documented, late mortality and the impact of presenting pathology on long-term outcomes remain poorly reported.nnMethods and Results— A database was built from 5 prospective studies and a single institutional series. Rates of perioperative adverse events were calculated, as were midterm death and reintervention rates. Multivariate analysis was performed with the use of logistic regression modeling. Kaplan-Meier survival curves were drawn for midterm outcomes. The database contained 1010 patients: 670 patients with thoracic aortic aneurysm, 195 with chronic type B aortic dissection, and 114 with acute type B aortic dissection. Lower elective mortality was observed in patients with chronic dissections (3%) compared with patients with aneurysms (5%). Multivariate analysis identified age, mode of admission, American Society of Anesthesiologists grade, and pathology as independent predictors of 30-day death ( P < 0.05). In the midterm, the all-cause mortality rate was 8, 4.9, and 3.2 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. The rates of aortic-related death were 0.6, 1.2, and 0.4 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively.nnConclusions— This study indicated that the midterm outcomes of endovascular repair of the thoracic aorta are defined by presenting pathology, associated comorbidities, and mode of admission. Nonaortic mortality is high in the midterm for patients with thoracic aortic aneurysm, and managing modifiable risk factors appears vital. Endovascular repair of the thoracic aorta results in excellent midterm protection from aortic-related mortality, regardless of presenting pathology.nn# Clinical Perspective {#article-title-33}

Retrograde aortic dissection after thoracic endovascular aortic repair.

Objective:To provide data regarding the etiology and timing of retrograde type A aortic dissection (RTAD) after thoracic endovascular aortic repair (TEVAR). Methods:Details of patients who had RTAD after TEVAR were obtained from the MOTHER Registry supplemented by data from a systematic review of the literature. Univariate analysis and binary logistic regression analysis of patient or technical factors was performed. Results:In MOTHER, RTAD developed in 16 of the 1010 patients (1.6%). Binary logistic regression demonstrated that an indication of TEVAR for aortic dissection (acute P = 0.000212; chronic P = 0.006) and device oversizing (OR 1.14 per 1% increase in oversizing above 9%, P < 0.0001) were significantly more frequent in patients with RTAD. Data from the systematic review was pooled with MOTHER data and demonstrated that RTAD occurred in 1.7% (168/9894). Most of RTAD occurred in the immediate postoperative (58%) period and was associated with a high mortality rate (33.6%). The odds ratio of RTAD for an acute aortic dissection was 10.0 (CI: 4.7–21.9) and 3.4 (CI: 1.3–8.8) for chronic aortic dissection. The incidence of RTAD was not significantly different for endografts with proximal bare stent (2.8%) or nonbare stent (1.9%) (P = 0.1298). Conclusions:Although RTAD after TEVAR is an uncommon complication, it has a high mortality rate. RTAD is significantly more frequent in patients treated for acute and chronic type B dissection, and when the endograft is significantly oversized. The proximal endograft configuration was not associated with any difference in the incidence of RTAD.

Imaging vascular trauma

Over the past 50 years the management of vascular trauma has changed from mandatory surgical exploration to selective non‐operative treatment, where possible. Accurate, non‐invasive, diagnostic imaging techniques are the key to this strategy. The purpose of this review was to define optimal first‐line imaging in patients with suspected vascular injury in different anatomical regions.

The diagnosis and management of aortic dissection

#### Summary pointsnnAortic dissection is caused by an intimal and medial tear in the aorta with propagation of a false lumen within the aortic media. It is part of the “acute aortic syndrome”—an umbrella term for aortic dissection, intramural haematoma, and symptomatic aortic ulcer (table⇓).1 Acute dissection is the most common aortic emergency, with an annual incidence of 3-4 per 100u2009000 in the United Kingdom and United States, which exceeds that of ruptured aneurysm.2 w1 w2 The prognosis is grave, with 20% preadmission mortality and 30% in-hospital mortality.2nnView this table:nnEuropean Society of Cardiologists’ classification of acute aortic syndrome nnnnThe best treatment depends on the anatomical and temporal classification of the disease. Aortic dissection is therefore categorised according to the site of the entry tear and the time between the onset of symptoms and diagnosis. A dissection is considered “acute” when the diagnosis is made within 14 days of onset, and thereafter it is termed “chronic.” The location of the entry tear plays a key role in treatment and outcome, and it is classified by being in the ascending aorta (Stanford type A dissection) or distal to …

St George's Vascular Institute Protocol: An Accurate and Reproducible Methodology to Enable Comprehensive Characterization of Infrarenal Abdominal Aortic Aneurysm Morphology in Clinical and Research Applications

Purpose To define the reproducibility of a protocol for the analysis of infrarenal abdominal aortic aneurysm (AAA) morphology for clinical and research purposes. Methods A protocol for the comprehensive assessment of preoperative AAA morphology based on formal systematic review and expert opinion featured 114 morphological parameters (maximum and minimum diameters, cross-sectional areas, vessel lengths, volumes, angulation, and calcification and tortuosity indices) in each of 3 regions: the neck, sac, and access vessels. To validate the protocol, 4 observers measured these variables on the preoperative computed tomographic angiograms from 50 patients (45 men; mean age 75 years, range 52–89) scheduled for endovascular aneurysm repair using software for 3-dimensional image reconstruction. One observer performed repeated measurements. The intra- and interobserver variabilities were calculated for all parameters; measurement time for all 114 features was recorded. Results Aortoiliac diameter, length, volume, area, and tortuosity index measurements showed good inter/intraobserver agreement. Aortic neck and aortoiliac angle measurements displayed high intra/interobserver repeatability coefficients (28%–43% and 29%–61%, respectively). Calcification measurements had the highest variability within and between observers: 39%–65% and 44%–96%, respectively. The measurement protocol was completed in a mean 105 minutes (range 55–420). Conclusion Accurate 3-dimensional analysis of AAA morphology can be performed reliably within a reasonable time. Measurements that relied on consistent anatomical landmarks were most reproducible. Assessment of angulation and calcification required a number of subjective judgments, increasing the potential for variation. Automated methods are likely to be more suitable for certain measurements.

A Systematic Review of Aortic Remodeling After Endovascular Repair of Type B Aortic Dissection: Methods and Outcomes

BACKGROUNDnEndovascular treatments of Stanford type B aortic dissection may help to promote aortic remodeling and reduce the incidence of aortic-related complications. The aim of this study was to review published literature describing aortic remodeling after endovascular treatmentxa0of aortic dissection.nnnMETHODSnA systematic review of the literature was performed which was compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The type of aortic morphology measurements made and the methods used to make them were characterized. The endpoints of interest were the change in these measurements over time.nnnRESULTSnAfter initial screening, 77 articles were identified; 16 of which met the inclusion criteria. Few studies used three-dimensional reconstruction software and none had validated their measurement protocol. True lumen (TL) and false lumen (FL) diameters, areas, and in some cases volumes were measured. Studies assessed the aorta at a variety of different levels and over different periods of follow-up. Acute dissection patients displayed more consistent degree of remodeling (thoracic FL thrombosis in 80% to 90%) than chronic dissection patients (38% to 91%). Less remodeling was seen below the diaphragm in both groups.nnnCONCLUSIONSnAortic remodeling after treatment for dissection is described in a highly heterogeneous manner. Despite this there appears to be a greater degree of complete FL resolution in patients with acute dissection than chronic. Factors such as length of aortic coverage and timing of treatment may explain the variation seen in the chronic dissection group. Consensus-based reporting standards are required to synthesize evidencexa0and inform clinical decisions regarding patient selection and operative timing.

Microvascular disease and risk of cardiovascular events among individuals with type 2 diabetes: a population-level cohort study

BACKGROUNDnDiabetes confers a two times excess risk of cardiovascular disease, yet predicting individual risk remains challenging. The effect of total microvascular disease burden on cardiovascular disease risk among individuals with diabetes is unknown.nnnMETHODSnA population-based cohort of patients with type 2 diabetes from the UK Clinical Practice Research Datalink was studied (n=49u2008027). We used multivariable Cox models to estimate hazard ratios (HRs) for the primary outcome (the time to first major cardiovascular event, which was a composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal ischaemic stroke) associated with cumulative burden of retinopathy, nephropathy, and peripheral neuropathy among individuals with no history of cardiovascular disease at baseline.nnnFINDINGSnDuring a median follow-up of 5·5 years, 2822 (5·8%) individuals experienced a primary outcome. After adjustment for established risk factors, significant associations were observed for the primary outcome individually for retinopathy (HR 1·39, 95% CI 1·09-1·76), peripheral neuropathy (1·40, 1·19-1·66), and nephropathy (1·35, 1·15-1·58). For individuals with one, two, or three microvascular disease states versus none, the multivariable-adjusted HRs for the primary outcome were 1·32 (95% CI 1·16-1·50), 1·62 (1·42-1·85), and 1·99 (1·70-2·34), respectively. For the primary outcome, measures of risk discrimination showed significant improvement when microvascular disease burden was added to models. In the overall cohort, the net reclassification index for USA and UK guideline risk strata were 0·036 (95% CI 0·017-0·055, p<0·0001) and 0·038 (0·013-0·060, p<0·0001), respectively.nnnINTERPRETATIONnThe cumulative burden of microvascular disease significantly affects the risk of future cardiovascular disease among individuals with type 2 diabetes. Given the prevalence of diabetes globally, further work to understand the mechanisms behind this association and strategies to mitigate this excess risk are warranted.nnnFUNDINGnCirculation Foundation.

Existing risk prediction methods for elective abdominal aortic aneurysm repair do not predict short-term outcome following endovascular repair

OBJECTIVEnImproving the safety of elective abdominal aortic aneurysm (AAA) repair has become an imperative. Five well-described risk-scoring systems developed on open aneurysm repair (OR) were tested on a multicenter contemporary sample of patients undergoing endovascular repair of AAA (EVR) to determine if they predicted 30-day morbidity and mortality.nnnMETHODSnThe Glasgow score (GAS), combined prognostic index (CPI), and its modification (M-CPI), the Leiden score and the Vascular Biochemical and Haematological Outctome Model (VBHOM) score were studied using a retrospective database of 846 patients. Thirty-day mortality and serious morbidity were used as end-points. A receiver-operator characteristic curves was plotted and the area under this (known as the c-statistic) was calculated to determine discriminatory ability of each model.nnnRESULTSnIncidence of postoperative mortality was 2.2% and serious morbidity was 12.3%. All scores were predictive of mortality except the Leiden score, which had a c-statistic of 0.603 (95% CI, 0.485-0.720; P = .123). The VBHOM score and the M-CPI had a c-statistic of 0.649 (95% CI, 0.514 -0.783; P = .026) and 0.653 (95% CI, 0.544-0.763; P = .026), respectively. The best performing scores were the GAS and CPI, which had a c-statistic of 0.677 (95% CI, 0.559-0.795; P = .008) and 0.679 (95% CI, 0.572-0.787; P = .007), respectively. No score effectively predicted morbidity.nnnCONCLUSIONnNone of the available scores predicted the outcome of EVR with enough accuracy to be recommended for clinical use. To improve preoperative risk prediction in EVR validation of new systems is required, taking into account morphologic features of the aneurysm to predict medium-term morbidity and re-intervention.

Systematic review of outcomes of combined proximal stent grafting with distal bare stenting for management of aortic dissection

OBJECTIVEnAvailable data on outcomes of combined proximal stent grafting with distal bare stenting for management of aortic dissection are limited. This is a systematic review of outcomes of this approach.nnnMETHODSnStudies involving combined proximal stent grafting with distal bare stenting for management of aortic dissection were systematically searched and reviewed.nnnRESULTSnA total of 4 studies were included, with 108 patients treated for acute (nxa0=xa054) and chronic (nxa0=xa054) aortic dissection. Technical success rate was 95.3% (range, 84-100). The 30-day mortality was 2.7% (range, 0%-5%). Morbidity rate within 30 days was 51.8% (range, 0%-65%) and included stroke (2.7%), paraplegia (2.7%), retrograde dissection (1.8%), renal failure (14.8%), severe cardiopulmonary complications (5.5%), and bowel ischemia (0.9%). Incidence of type I endoleak was 9.2% (10/108). During follow-up, 5 patient deaths (4.6%) were related to aortic rupture or aortic repair. Reintervention rate was from 12.9%. Two cases of delayed retrograde type A dissection (1.9%) and 1 case of aortobronchial fistula (0.9%) were reported. Most common delayed complication was thoracic stent-graft migration (4.7%). Device failure rate was 9.2%. Favorable aortic remodeling was observed: studies reporting midterm follow-up of the true lumen demonstrated high rates of false-lumen regression and true-lumen expansion. At 12 months, complete false-lumen thrombosis was observed at the thoracic level in 70.4% and at the abdominal level in 13.5%.nnnCONCLUSIONSnCombined proximal stent grafting with distal bare stenting for management of aortic dissection appears to be a reasonable approach for type B aortic dissection, clearly improved true-lumen perfusion and diameter although failing to suppress false-lumen patency completely. Contemporary information on this approach is mainly provided by small series with a wide range of results.

The Glasgow Aneurysm Score does not predict mortality after open abdominal aortic aneurysm in the era of endovascular aneurysm repair

OBJECTIVEnEndovascular aneurysm repair (EVAR) has reduced early adverse outcomes from abdominal aortic aneurysm (AAA) repair. Preferential use of EVAR may have altered the profile of patients who undergo open repair. The validity of scoring systems such as the Glasgow Aneurysm Score (GAS), devised when open surgery was the only treatment, required reappraisal.nnnMETHODSnPatients were identified from a database of patients undergoing elective infrarenal aneurysm repair at seven United Kingdom centers, and the GAS was calculated for each patient. Discrimination and calibration were calculated to determine the performance of the model in this setting using the C statistic, tertile analysis, and the χ(2) test. Univariate analysis was performed to determine if a new iteration of the GAS could be produced.nnnRESULTSnWe identified 330 patients who met the inclusion criteria. There were 18 deaths ≤30 days of surgery (5.4%). The average (standard deviation) GAS was 78.6 (8.8) for the survivors and 81.9 (10.4) for nonsurvivors (P = .122). The C statistic was 0.625 (95% confidence interval, 0.481-0.769; P = .75) suggesting a discriminatory ability not much better than chance alone. Despite this, calibration of the model was good. There was no significant difference in the comorbidities of either group, so no recalibration of the GAS could be performed.nnnCONCLUSIONnThe GAS did not discriminate between survivors and nonsurvivors after open AAA repair in this cohort. In the era of EVAR, it is possible that the GAS does not predict the outcome of open AAA repair. An alternative explanation is that patients with risk factors for poor outcomes from EVAR, such as adverse AAA morphology, are being selected out for open repair.