Preoperative prediction of mortality within 1 year after elective thoracic endovascular aortic aneurysm repair

Abstract

Objective Thoracic Endovascular Aortic Repair (TEVAR) is known to have a mortality benefit over open repair in patients with descending thoracic aneurysms, and has become a mainstay of therapy. Because death before 1 year after TEVAR likely indicates an ineffective therapy, we have created a predictive model for mortality within 1-year using factors available in the preoperative setting. Methods A registry of 526 TEVARs performed at the University of Florida between September 2000 and November 2010 was queried for patients with degenerative descending thoracic aneurysm as their primary pathology. Procedures with emergent or urgent indications were excluded. Pre-operatively available variables such as baseline co-morbidities, anatomic and procedure specific planning details were recorded. Univariate predictors of mortality were analyzed with multivariable Cox proportional hazards to identify independent predictors of 30-day and 1-year mortality, defined as mortality within 30 days and within one year following TEVAR, respectively. Results A total of 224 patients were identified and evaluated. Thirty-day and 1-year mortality were 3% (n=7) and 15% (n=33). Multivariable predictors of 1-year mortality included: age >70 (p=0.001, HR 5.8, 95% CI 2.1–16.0), adjunctive intra-operative procedures (e.g. brachiocephalic/visceral stents, concomitant arch de-branching procedures) (p=0.001, HR 4.5, 95% CI 1.9–10.8), peripheral arterial disease (PAD; p=0.006, HR 3.0, 95% CI 1.4–6.7), coronary artery disease (CAD; p=0.02, HR 2.4, 95% CI 1.1–4.9), and chronic obstructive pulmonary disease (COPD; p=0.06, HR 1.9, 95% CI 1.0–3.9). A diagnosis of hyperlipidemia was protective (p=0.006, HR 0.4, 95% CI 0.2–0.7). When patients are grouped into those with 0, 1, 2, 3 or 4+ of these risk factors, the predicted one year mortality was 1, 3, 10, 27 and 54%, respectively. Conclusions Factors are available in the pre-operative setting that are predictive of mortality within 1-year after TEVAR, and can guide clinical decision-making regarding the timing of repair. Patients with multiple risk factors such as age ≥70, CAD, COPD, and a need for an extensive procedure involving adjunctive therapies have a high predicted mortality within one year, and may be best served by waiting for a larger aneurysm size to justify the risk of intervention.

Pathology-specific secondary aortic interventions after thoracic endovascular aortic repair

“…The following aortic stent grafts were used during the study interval: TAG/C-TAG 45% (W. L. Gore and Associates, Flagstaff, AZ), Zenith/TX2 40% (Cook Inc, Bloomington, IN), Talent/Valiant 9% (Medtronic Inc, Santa Rosa, CA), , and Bolton Relay 5% (Bolton Medical, Sunrise, FL). Previous reports from our group reflect a homogeneous approach to treatment philosophy 10 that is based on a multi-disciplinary team of Vascular and Cardiovascular surgeons. The practice patterns at the University of Florida have been previously described in detail regarding anatomic considerations 11 , characteristics of the TEVAR implantation procedure 11-13 and postoperative care of patients with TAA 11 , AD 13 , CTBAD 14 , and TAT 12 treated with TEVAR.…”

Predicting Mid-term All-cause Mortality in Patients Undergoing Elective Endovascular Repair of a Descending Thoracic Aortic Aneurysm

“…Patients with aneurysms that extended more proximally and required >2 devices to repair were less likely to survive to follow-up, which is consistent with other work that has suggest more proximal pathology is associated with increased mortality at one year. 6 Increasing maximum aneurysm diameter and diameter of the proximal and distal neck was also associated with poor survival, as was severe calcification of the distal aorta and access vessels. Advanced, generalised aneurysmal and calcific arterial disease is associated with a combination of risk factors that would increase the risk of death from various causes, and has been demonstrated in previous work.…”

“…The dataset used to externally validate the risk-stratification systems was obtained from investigators from the University of Florida College of Medicine (UFCM), who maintain a prospective endovascular surgery database at their institution for all patients that have undergone TEVAR 6 . Institutional ethics board committee was applied for and approved for the use of these data in this study.…”

“…Others have focused on one-year survival after AAA repair, placed in the context of rupture risk based on aneurysm diameter, which may be a more useful measure of utility of repair. 6 Risk stratification models must be validated to prove that they are reliable before use in clinical practice, 7 and this validation can be internal, temporal or external, 8 Internal validation uses the same dataset that the models were initially developed from, and is the least stringent form of validation. Temporal validation utilizes the same source as the original dataset, but uses new prospectively collected data acquired after the initial model has been developed.…”

Postoperative management

“…cardiac surgical procedures or have a degree of myocardial impairment.Prediction of mortality and complications have traditionally been difficult and dependent on these patient related factors, as much as severity of vascular disease and complexity of surgery(62).…”