Using Machine Learning to Predict Outcomes of Patients with Blunt Traumatic Aortic Injuries.

INTRODUCTION: The optimal management of blunt thoracic aortic injury (BTAI) remains controversial, with experienced centers offering therapy ranging from medical management to TEVAR. We investigated the utility of a machine learning (ML) algorithm to develop a prognostic model of risk factors on mortality in patients with BTAI. METHODS: The Aortic Trauma Foundation registry was utilized to examine demographics, injury characteristics, management and outcomes of patients with BTAI. A STREAMLINE (A Simple, Transparent, End-To-End Automated Machine Learning Pipeline Facilitating Data Analysis and Algorithm Comparison) model as well as logistic regression (LR) analysis with imputation using chained equations was developed and compared. RESULTS: From a total of 1018 patients in the registry, 702 patients were included in the final analysis. Of the 258 (37%) patients who were medically managed, 44 (17%) died during admission, 14 (5.4%) of which were aortic related deaths. 444 (63%) patients underwent TEVAR and 343 of which underwent TEVAR within 24 hours of admission. Amongst TEVAR patients, 39 (8.8%) patients died and 7 (1.6%) had aortic related deaths. (Table 1) Comparison of the STREAMLINE and LR model showed no significant difference in ROC curves and high AUCs of 0.869 (95% CI, 0.813 - 0.925) and 0.840 (95% CI, 0.779 - 0.900) respectively in predicting in-hospital mortality. Unexpectedly, however, the variables prioritized in each model differed between models (Figure 1A-B). The top three variables identified from the LR model were similar to that from existing literature. The STREAMLINE model, however, prioritized location of the injury along the lesser curve, age and aortic injury grade (Figure 1A). CONCLUSIONS: Machine learning provides insight on prioritization of variables not typically identified in standard multivariable logistic regression. Further investigation and validation in other aortic injury cohorts are needed to delineate the utility of ML models. LEVEL OF EVIDENCE: Level IIIStudy TypeOriginal research (prognostic/epidemiological).

Initial Outcomes of the Gore TAG Thoracic Branch Endoprosthesis for Endovascular Repair of Blunt Thoracic Aortic Injury.

BACKGROUND: Endovascular repair of blunt thoracic aortic injury (BTAI) has dramatically reduced the morbidity and mortality of intervention. Injuries requiring zone 2 coverage of the aorta traditionally require left subclavian artery (LSA) sacrifice or open revascularization. Furthermore, these injuries are associated with an increased risk of in-hospital mortality and long-term morbidity. Here we report 1-year outcomes of total endovascular repair of BTAI with the GORE® TAG® Thoracic Branch Endoprosthesis for LSA preservation. METHODS: Across 34 investigative sites, 9 patients with BTAI requiring LSA coverage were enrolled in a nonrandomized, prospective study of a single-branched aortic endograft. The thoracic branch endoprosthesis device allows for graft placement proximal to the LSA and incorporates a single side branch for LSA perfusion. RESULTS: This initial cohort included 8 male and 1 female patient with a median age of 43 (22, 76) and 12 months of follow-up. Five total years of follow-up are planned. All participants had grade 3 BTAI. All procedures took place between 2018 and 2019. The median injury severity score was 2 (0, 66). The median procedure time was 109 min (78, 162). All aortic injuries were repaired under general anesthesia and with heparinization. A spinal drain was used in one patient. Post-deployment balloon angioplasty was conducted in one case at the distal landing zone. There was one asymptomatic LSA branch occlusion 6 months after repair. It was attributed to the purposeful proximal deployment of the branch stent to accommodate an early vertebral takeoff. The occlusion did not require revascularization. There were no strokes, mortalities, or aortic adverse events (migration, endoleak, native aortic expansion, dissection, or thrombosis) through 12 months of follow-up. CONCLUSIONS: Initial cohort outcomes suggest that endovascular repair of zone 2 BTAI is feasible and has favorable outcomes using the thoracic branch device with LSA preservation. Additional cases and longer-term follow-up are required for a definitive assessment of the device's safety and durability in traumatic aortic injuries.

Interwoven nitinol stents for the treatment of infrainguinal peripheral arterial disease.

Endovascular treatment of peripheral arterial disease has emerged as a minimally-invasive alternative to surgical intervention and has often become the first-line therapy. The patency of these interventions has shown promise but has remained variable depending upon the location, length of lesion and device used for a particular treatment. Specifically, one of the most common locations that is treated with endovascular means for chronic-limb threatening ischemia is the femoropopliteal region. This area of the arterial tree is highly exposed to movements such as flexion, extension, and rotational torque; as such, placing metallic stents can result in kinking and damage to the stent, and subsequently the artery, over time. Stent characteristics are defined according to the metal property that composes them. Nitinol has been experimented with for use in the arterial tree since the 1980s namely because of its uniquely elastic mechanical properties, which were ideal for sustaining its shape within an anatomic area prone to positional variability. More recently, nitinol stents were introduced in an interwoven fashion, the design of which creates a scaffold of structure for the elastic property of the metal to remain reinforced within highly flexible arteries. This review article discusses the available literature and evidence behind the use of these interwoven nitinol stents in lower extremity peripheral arterial interventions.

Contemporary outcomes of initial treatment strategy of endovascular intervention or bypass in patients with critical limb ischemia.

OBJECTIVE: The optimal management for revascularization after critical limb ischemia (CLI) is controversial due to limited studies comparing long-term results of endovascular and open techniques. This study compares long-term outcomes after initial management of CLI via lower extremity bypass (LEB) and percutaneous vascular intervention (PVI). METHODS: This retrospective cohort study investigates outcomes of patients who underwent endovascular or open surgical management for CLI at a single institution from 2013-2018. All patients with diagnosis of CLI were included and separated based on initial therapy of PVI or LEB. Demographic, procedural, and follow-up data were assessed. Primary endpoints included major adverse limb events (MALE), specifically the need for major amputation and reintervention. Secondary endpoints included mortality at 30 days and one year. A multivariable Cox Proportional Hazard regression model was used to assess the relationship between Surgery group and time to MALE/death while controlling for confounding variables. RESULTS: This study identified 338 patients with an initial diagnosis of CLI who underwent either LEB (n = 108, 32%) or PVI (n = 230, 68%). The average age was 71.4, 54.4% were male, 30% were African American, 53.6% were diabetic, and 93.2% had hypertension. Patients who underwent LEB were more predominantly smokers (p = .003) and less predominantly on dialysis at time of surgery (p = .01). Re-intervention rates in the bypass group (11%) were not significantly different than the PVI group (9%; p = .95). In the bypass group, 20 (19%) patients had a major amputation with a median time of 189.5 days compared to 23 (10%) patients at a median time of 113 days in the PVI group; however, this difference was not significant (p = .16). There was no significant difference in 1-year mortality between the LEB (2%) and PVI group (4%; p = .2). The cumulative incidence of MALE/death at 30 days was 4.0% in the bypass group and 3.7% in the PVI group (p = .2). Incidences of MALE/death were 21.1% and 48.5% in the bypass group and 19.7 and 45.9% in the PVI group at one and 2 years, respectively. Intervention type was not found to be significantly associated with MALE/death after controlling for possible confounders (HR = 0.82, p = .43). CONCLUSIONS: In the initial management of CLI, there is no significant difference in long-term outcomes in terms of major amputation, need for reintervention, limb-salvage, and 1-year mortality.

Midterm Results of the Supera Stent for the Treatment of Femoropopliteal Occlusive Disease.

BACKGROUND: The Supera (Abbott Vascular, Santa Clara, CA) stent is an interwoven nitinol, shape-memory stent with high strength and flexibility characteristics which are purported to increase resistance to kinking and compression. The purpose of this study was to review single-center outcomes of the use of this stent in the femoropopliteal segment. METHODS: We performed a single-center, retrospective analysis of patients who underwent Supera stent placement for femoropopliteal occlusive disease from 2016-2019. Data was collected on patient demographics and procedural details. Follow-up imaging data, including duplex imaging and ankle-brachial indices, and clinical data were abstracted from encounter notes. RESULTS: Sixty-two patients with 72 unique Supera stent placements were identified. Mean age was 76 and 69% were male. 56% of patients had severe calcification and 11% had moderate calcification. 48% of lesions were Trans-Atlantic Inter-Society Consensus Document C or D lesions. Primary patency rates at 12, 24, and 36 months were 85%, 82%, and 75%, respectively. Primary patency was not affected significantly by lesion length, degree of calcification, number of outflow vessels, concomitant interventions, or stent size. CONCLUSIONS: These results demonstrate sustained primary patency with the Supera stent over a 3-year interval in treatment of patients with femoropopliteal occlusive disease, including in the setting of severely calcified vessels.

Hippocampal mitogen-activated protein kinase phosphatase-1 regulates behavioral and systemic effects of chronic corticosterone administration.

Clinical reports indicate a bidirectional relationship between mental illness and chronic systemic diseases. However, brain mechanisms linking chronic stress and development of mood disorders to accompanying peripheral organ dysfunction are still not well characterized in animal models. In the current study, we investigated whether activation of hippocampal mitogen-activated protein kinase phosphatase-1 (MKP-1), a key factor in depression pathophysiology, also acts as a mediator of systemic effects of stress. First, we demonstrated that treatment with the glucocorticoid receptor (GR) agonist dexamethasone or acute restraint stress (ARS) significantly increased Mkp-1 mRNA levels within the rat hippocampus. Conversely, administration of the GR antagonist mifepristone 30 min before ARS produced a partial blockade of Mkp-1 upregulation, suggesting that stress activates MKP-1, at least in part, through upstream GR signaling. Chronic corticosterone (CORT) administration evoked comparable increases in hippocampal MKP-1 protein levels and produced a robust increase in behavioral emotionality. In addition to behavioral deficits, chronic CORT treatment also produced systemic pathophysiological effects. Elevated levels of renal inflammation protein markers (NGAL and IL18) were observed suggesting tissue damage and early kidney impairment. In a rescue experiment, the effects of CORT on development of depressive-like behaviors and increased NGAL and IL18 protein levels in the kidney were blocked by CRISPR-mediated knockdown of hippocampal Mkp-1 prior to CORT exposure. In sum, these findings further demonstrate that MKP-1 is necessary for development of enhanced behavioral emotionality, while also suggesting a role in stress mechanisms linking brain dysfunction and systemic illness such as kidney disease.

Outcomes of Thoracic Endovascular Aneurysm Repair (TEVAR) in Patients With Connective Tissue Disorders.

OBJECTIVES: Thoracic endovascular aortic repair (TEVAR) remains controversial in patients with connective tissue disorders given the concern for durability. We report on the largest series to date on outcomes of patients with thoracic aortic disease and connective tissue disorders treated with TEVAR. METHODS: The Vascular Quality Initiative registry identified 12 207 patients treated with TEVAR from January 2010 to December 2018, including 102 with Marfans, Ehlers-Danlos, or Loey-Dietz syndrome. Outcomes were analyzed per the Society for Vascular Surgery reporting standards. RESULTS: Median age was 50.6 years (interquartile range: 57.0-75.0), and 62 (60.7%) were male. Eighty-eight (86.3%) patients had Marfan, 9 (8.8%) had Ehlers-Danlos, and 5 (4.9%) had Loey-Dietz syndrome. Twenty-six (25.5%) patients were treated for degenerative aneurysmal disease and 76 (74.5%) patients for type B dissections (33 acute, 31 chronic). Most common indications for interventions in patients with type B dissection were pain (n = 41), aneurysmal degeneration (n = 16), and malperfusion (n = 8), with 3 patients who presented ruptured. There was no significant difference in perioperative complications between acute/chronic dissections and aneurysms (P = .14). Percutaneous access was utilized in 61.7% of patients, with a 2.9% rate of arterial injury requiring reintervention. Follow-up data were available for 75 (73.3%) patients at a mean follow-up of 15.6 months. Overall mortality was 5.3%. There were 30 patients with follow-up endoleak data, and 8 (26.7%) endoleaks were identified. All endoleaks were in patients treated for acute type B dissection, and all resolved after a mean of 2.1 reinterventions. Three patients treated for acute Type B Aortic Dissection (TBAD) had retrograde dissections requiring intervention. DISCUSSION: Thoracic endovascular aortic repair for patients with connective tissue disorders can be performed with low perioperative mortality, spinal cord ischemia, or Cerebrovascular Accident (CVA). On follow-up, acute type B aortic dissections represent a higher risk subgroup with increased rates of endoleak and retrograde dissection. Closer follow-up for these patients and early reintervention may be beneficial.