Development and Validation of a Risk Prediction Tool for In-hospital Mortality After Thoracic Endovascular Repair in Patients with Blunt Thoracic Aortic Injury Using the Aortic Trauma Foundation Registry

BACKGROUND

The objective of our present effort was to use an international blunt thoracic aortic injury (BTAI) registry to create a prediction model identifying important preoperative and intraoperative factors associated with postoperative mortality, and to develop and validate a simple risk prediction tool that could assist with patient selection and risk stratification in this patient population.

METHODS

For the purpose of the present study, all patients undergoing thoracic endovascular aortic repair (TEVAR) for BTAI and registered in the Aortic Trauma Foundation (ATF) database from January 2016 as of June 2022 were identified. Patients undergoing medical management or open repair were excluded. The primary outcome was binary in-hospital all-cause mortality. Two predictive models were generated: a preoperative model (i.e. only including variables before TEVAR or intention-to-treat) and a full model (i.e. also including variables after TEVAR or per-protocol).

RESULTS

Out of a total of 944 cases included in the ATF registry until June 2022, 448 underwent TEVAR and were included in the study population. TEVAR for BTAI was associated with an 8.5% in-hospital all-cause mortality in the ATF dataset. These study subjects were subsequently divided using 3:1 random sampling in a derivation cohort (336; 75.0%) and a validation cohort (112; 25.0%). The median age was 38 years, and the majority of patients were male (350; 78%). A total of 38 variables were included in the final analysis. Of these, 17 variables were considered in the preoperative model, 9 variables were integrated in the full model, and 12 variables were excluded owing to either extremely low variance or strong correlation with other variables. The calibration graphs showed how both models from the ATF dataset tended to underestimate risk, mainly in intermediate-risk cases. The discriminative capacity was moderate in all models; the best performing model was the full model from the ATF dataset, as evident from both the Receiver Operating Characteristic curve (Area Under the Curve 0.84; 95% CI 0.74-0.91) and from the density graph.

CONCLUSIONS

In this study, we developed and validated a contemporary risk prediction model, which incorporates several preoperative and postoperative variables and is strongly predictive of early mortality. While this model can reasonably predict in-hospital all-cause mortality, thereby assisting physicians with risk-stratification as well as inform patients and their caregivers, its intrinsic limitations must be taken into account and it should only be considered an adjunctive tool that may complement clinical judgment and shared decision-making.

Outcomes of thoracic endovascular aortic repair in patients with concomitant blunt thoracic aortic injury and traumatic brain injury from the Aortic Trauma Foundation global registry

BACKGROUND

Traumatic brain injury (TBI) and blunt thoracic aortic injury (BTAI) are the top two leading causes of death after blunt force trauma. Patients presenting with concomitant BTAI and TBI pose a specific challenge with respect to management strategy, because the optimal hemodynamic parameters are conflicting between the two pathologies. Early thoracic endovascular aortic repair (TEVAR) is often performed, even for minimal aortic injuries, to allow for the higher blood pressure parameters required for TBI management. However, the optimal timing of TEVAR for the treatment of BTAI in patients with concomitant TBI remains an active matter of controversy.

METHODS

The Aortic Trauma Foundation international prospective multicenter registry was used to identify all patients who had undergone TEVAR for BTAI in the setting of TBI from 2015 to 2020. The primary outcomes included delayed ischemic or hemorrhagic stroke, in-hospital mortality, and aortic-related mortality. The outcomes were examined among patients who had undergone TEVAR at emergent (<6 vs ≥6 hours) or urgent (<24 vs ≥24 hours) intervals.

RESULTS

A total of 100 patients (median age, 43 years; 79% men; median injury severity score, 41) with BTAI (Society for Vascular Surgery BTAI grade 1, 3%; grade 2, 10%; grade 3, 78%; grade 4, 9%) and concomitant TBI who had undergone TEVAR were identified. Emergent repair was performed for 51 patients (51%). Comparing emergent repair (<6 hours) to urgent repair (≥6 hours), no difference was found in delayed cerebral ischemic events (2.0% vs 4.1%; P = .614), in-hospital mortality (15.7% vs 22.4%; P = .389), or aortic-related mortality (2.0% vs 2.0%; P = .996) and no patient had experienced delayed hemorrhagic stroke. Likewise, repairs conducted in an urgent (<24 hours) setting showed no differences compared with those completed in an emergent (≥24 hours) setting regarding delayed ischemic stroke (2.6% vs 4.3%; P = .548), in-hospital mortality (18.2% vs 21.7%; P = .764), or aortic-related mortality (1.3% vs 4.3%; P = .654), and no patient had experienced delayed hemorrhagic stroke.

CONCLUSIONS

In contrast to prior retrospective efforts, results from the Aortic Trauma Foundation international prospective multicenter registry have demonstrated that neither emergent nor urgent TEVAR for patients with concomitant BTAI and TBI was associated with delayed stroke, in-hospital mortality, or aortic-related mortality. In these patients, the timing of TEVAR did not have an effect on the outcomes. Therefore, the decision to intervene should be guided by individual patient factors rather than surgical timing.

Outcomes and practice patterns of medical management of blunt thoracic aortic injury from the Aortic Trauma Foundation global registry

OBJECTIVE

Blunt thoracic aortic injury (BTAI) is the second leading cause of death from blunt trauma. In the present study, we aimed to determine the outcomes of medical management (MM) for BTAI. We hypothesized from the results of several previously reported studies, that patients with a minimal aortic injury (BTAI grades 1 and 2) could safely be treated with definitive MM alone.

METHODS

The Aortic Trauma Foundation international prospective multicenter registry was used to examine the demographics, injury characteristics, management, and outcomes of patients with BTAI. We analyzed a subset of patients for whom MM was initiated as definitive therapy.

RESULTS

From November 2016 to April 2020, 432 patients (median age, 41 years; 76% male; median injury severity score, 34) with BTAI (Society for Vascular Surgery grade 1, 23.6%; grade 2, 14.4%; grade 3, 51.2%; grade 4, 10.9%) were evaluated. Of the 432 patients, 245 (57%) had received MM in the initial period and 114 (26.4%) had received MM as the planned definitive therapy (grade 1, 59.6%; grade 2, 23.7%; grade 3, 15.8%; grade 4, 0.9%). The most common mechanism of BTAI was a motor vehicle collision (60.4%). Hypotension was present on arrival in 74 patients (17.2%). Continuous titratable infusion of antihypertensive medication was used for 49.1%, followed by intermittent bolus administration (29.8%), with beta-blockers (74.6%) the most common agent used. Treatments were targeted to a goal systolic blood pressure for 83.3%, most often to a target goal systolic blood pressure <120 mm Hg (66.3%). The MM goals based on blood pressure control were attained in 64.0% (73 of 114). Twelve patients (10.5%; grade 1, 1; grade 2, 0; grade 3, 10; grade 4, 1) had required subsequent intervention after MM. Eleven patients (9.6%) had undergone thoracic endovascular aortic repair and one (0.9%) had required open repair for a grade 4 injury. The overall in-hospital mortality for patients selected for definitive MM was 7.9%. No aortic-related deaths had occurred in the patients receiving definitive MM.

CONCLUSIONS

Approximately one in four patients with BTAI will receive MM as definitive therapy. The variation in the pharmacologic therapies used is considerable. MM for patients with minimal aortic injury (BTAI grades 1 and 2) is safe and effective, with a low overall intervention rate and no aortic-related deaths. These findings support the use of definitive MM for grade 2 BTAI.

The first commercial use of the Valiant Navion stent graft system for endovascular repair of a descending thoracic aortic aneurysm

Objectives

Thoracic endovascular aortic repair (TEVAR) is the standard of care for descending thoracic aortic aneurysms (DTAA), and newer generation stent grafts have significant design improvements compared to earlier generation devices.

Methods

We report the first commercial use of the Medtronic Valiant Navion stent graft for treatment of an 85-year-old woman with a 5.8 cm DTAA and a highly tortuous thoracic aorta.

Results

A percutaneous TEVAR was performed using a two-piece combination of the Valiant Navion FreeFlo and CoveredSeal stent graft configurations for zones 2–5 coverage. The devices were successfully delievered through highly tortuous anatomy and deployed, excluding the entire length of the aneurysm with precise landing, excellent apposition and no evidence of endoleak. The patient tolerated the procedure well and has had no stent graft-related complications through one-year follow-up.

Conclusions

Design enhancements such as a lower profile delivery system, better conformability, and a shorter tapered tip are some of the improvements to this third-generation TEVAR device. Coupled with the multiple configuration options available, this gives physicians a better tool to treat thoracic aortic pathologies in patients with challenging anatomy. The early results are encouraging, and evaluation of long-term outcomes will continue.

Abstract P1-01-15: Relationship amongst sentinel lymph node pressure, volume, and breast cancer tumor size

Background:

Angiogenesis in growing breast cancers (BCs) leads to leaky vessels with resultant increased interstitial fluid volume, pressure, and enhanced lymphatic flow to axillary sentinel lymph nodes (SLNs). As the BC grows the intra-tumoral pressure increases. SLNs are often firm and enlarged because of reactive sinusoidal hyperplasia, growth of metastases, and stromal responses to cytokines and fluid flow. We hypothesized that intranodal pressure (INP) of the SLN would increase with increasing primary BC tumor and SLN size.

Methods:

Axillary SLNs were identified intra-operatively using standard blue dye and radioactive techniques. The stained lymph node was visually detected and confirmation was made with a gamma probe. Pressure in the SLN was measured in vivo using a noncoring needle and recording device in 278 patients. A zero mmHg reading was obtained in the air adjacent to the node, and the INP was recorded in the SLN. The axillary SLNs along with the primary BC were excised and examined using standard pathological techniques. The size of the primary tumor (maximum dimension in cm) was recorded for each patient, along with the SLN volume = (4/3)(π)(length x width x thickness), and compared to the INP. Spearman's correlation coefficients were used to look at relationships between variables. We looked for significant relationships between variables while controlling for SLN metastasis size using multiple regression modeling. Statistical significance was set at p≤0.05.

Results:

INP from tumor-containing SLNs was 21.39±12.83 mmHg (N = 62), and 9.25±6.33 mmHg (N = 216) for those with no SLN metastasis (p&lt;0.0001). SLN metastasis size increased significantly with increasing tumor size (p&lt;0.0001). Increasing INP significantly correlated with increasing SLN volume (p = 0.0030, R = 0.1776), tumor size (p&lt;0.0001, R = 0.2603), and SLN metastasis size (p&lt;0.0001, R = 0.4633). Increasing tumor size did not significantly correlate with SLN volume (p = 0.3510, R = -0.0561). Volume of the SLN did not significantly differ between nodes with and without metastases (p = 0.2462). When controlling for the SLN metastasis size, the relationship between increasing volume of the SLN and INP remained significant (p = 0.0309), while the relationship between increasing tumor size and INP was no longer significant (p = 0.0910).

Conclusion:

The INP of BC SLNs increased with increased tumor metastasis size and also with the volume of the SLN. Because the SLN volume did not differ when metastasis was present or not, and because the INP was elevated when there was metastasis present, it is likely that pre-metastatic angiogenesis and lymphangiogenesis, seen pathologically as sinusoidal hyperplasia, may not be enough to cause the interstitial fluid pressure to rise. Our data suggests that increased INP requires tumor cells in the SLN or mechanical factors due to tumor emboli to create conditions sufficient to increase the measurable pressure significantly. Proof of this postulate requires careful quantitative evaluation of other components in the metastatic SLN, such as stromal and lymphoid hyperplasia.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-15.