Non-operative management of blunt traumatic aortic injuries

Abstract

BACKGROUND

Blunt traumatic aortic injury (BTAI) is a life-threatening injury, commonly associated with high-speed motor vehicle collisions. Historically, open surgical repair was the standard treatment, however with the advancement of endovascular techniques such as thoracic endovascular aortic repair (TEVAR), management strategies shifted towards endovascular repairs. Non-operative management (NOM) strategies are also favored for patients with low-grade injuries and particularly high-grade injuries recently. The Society for Vascular Surgery (SVS) 2011 guidelines recommend that grade I injuries should be managed non-operatively; newer studies also support NOM for grade II injuries.

AIM

To review higher-grade injuries. NOM can be favored for selected patients with grade III injuries.

METHODS

A retrospective review of literature to assess NOM in BTAI, using the PubMed, CINHAL, EBSCO, and Google Scholar databases, included articles published in the last 20 years between January 2003 and December 2023. Studies included Cohort studies, case-control studies, and observational studies. Two authors independently screened the titles, abstracts, and performed data extraction. Outcomes were compared by the type of treatment: NOM vs endovascular repair (TEVAR) vs open repair.

RESULTS

We identified 27 studies in our review that met the selection criteria. Most of the studies were based on retrospective analysis of institutional data, and only 16 papers reported BTAI in accordance with SVS reporting standards. A trend of increasing mortality across the BTAI grade was observed. There were heterogeneous results regarding outcomes after non-operative compared with endovascular and surgical repair. For grade I and II BTAI, NOM was associated with lower mortality, reduced rates of unplanned intervention, and resolution of pathology on follow-up. There were reports of NOM of grade III BTAI with reasonable outcomes and a high rate of resolution on follow-up, but data were limited due to very few studies focusing on this subgroup.

CONCLUSION

This review article provides the most up-to-date literature. Currently literature supporting the NOM for low-grade BTAI (grades I and II) treatment. Current SVS guidelines recommend endovascular repair for grade III BTAI patients; however, a few studies showed that grade III BTAI can be managed non-operatively with active surveillance in a selected group of patients. Literature requires further studies to compare NOM vs TEVAR in higher-grade BTAI population.

Key Words: Blunt trauma; Aortic injury; Non-operative management; Outcomes; Thoracic endovascular aortic repair

Core Tip: The non-operative management of blunt traumatic grade I aortic injury is a relatively common practice. The management of grade II aortic injury varies; some providers prefer an endovascular approach, while others prefer non-operative management. Successful non-operative management is associated with lower mortality and resolution of the primary pathology. However, non-operative management if not routinely applied for higher grade aortic injuries and the majority prefer an endovascular approach for higher grade, III or more, injury.

INTRODUCTION

Blunt traumatic aortic injury (BTAI) is a life-threatening condition caused by rapid deceleration forces, commonly associated with high-speed motor vehicle collisions, falls from significant heights, and other blunt trauma mechanisms. Despite improvement in diagnosis and treatment, thoracic aortic injuries remain highly fatal[1-3]. Aortic injuries can occur anywhere from the ascending aorta to the iliac bifurcation. The aortic isthmus is the most frequently affected site due to its anatomical fixation between the mobile aortic arch and the descending thoracic aorta[4]. The spectrum of BTAI ranges from minor intimal tears to complete aortic rupture, with the latter often being fatal before hospital arrival[2]. Historically, open surgical repair was the standard treatment for BTAI, but it was associated with significant morbidity and perioperative mortality[1,3,5,6]. With the advancement of thoracic endovascular aortic repair (TEVAR), management strategies have shifted to minimally invasive treatment, demonstrating improved survival rates and reduced complications compared to open repair. More recently, non-operative management (NOM) has emerged as an alternative strategy, particularly for select patients with low-grade injuries and particularly high-grade injuries[7].

The Society for Vascular Surgery (SVS) classifies BTAI into four grades: Grade I (intimal tear), grade II (intramural hematoma), grade III (pseudoaneurysm), and grade IV (rupture)[8-10]. While TEVAR is generally recommended for grades II-IV, emerging evidence suggests that some grade II and even select grade III injuries may be managed conservatively with strict blood pressure control and serial imaging[4,7]. Recent studies have demonstrated promising outcomes for NOM in higher-grade injuries when carefully selected, challenging the traditional approach of immediate TEVAR[3,11,12]. This review evaluates the NOM of higher-grade BTAI, examining patient selection criteria, clinical outcomes, and long-term safety. By synthesizing current evidence, we seek to clarify the role of NOM in the high-grade BTAI patient population and provide insight into best practices for its implementation.

MATERIALS AND METHODS

Eligibility criteria

We performed a review of the literature to assess the current evidence regarding NOM of BTAI. We included studies that met the following eligibility criteria: (1) Study design: Cohort studies, case-control studies, randomized-controlled trials and observational studies; (2) Population: Adult patients (≥ 18 years old) diagnosed with BTAI; (3) Intervention: NOM (consisting of observation, medical management andserial imaging), open surgical repair and endovascular techniques; and (4) Outcomes: Primary outcomes - mortality rates, aortic rupture, and need for surgical intervention; secondary outcomes - complications (e.g., infection, end-organ failure), long-term morbidity, and survival rates.

Language

Studies published in English.

Timeframe: Studies published between January 2003 and December 2023

We excluded studies that focused on traumatic injuries not involving the aorta, studies with pediatric populations, and those without clear outcome reporting.

Information sources: We conducted a comprehensive search for relevant studies using the following electronic databases: PubMed, CINHAL, EBSCO, and Google Scholar. We also reviewed the references of included studies to identify additional relevant articles. The search was conducted in December 2023. We used a combination of the following key search terms and MeSH (Medical Subject Headings) terms: “blunt traumatic aortic injury”, “non-operative management”, “non-surgical treatment”, “blunt aortic injury management”, “endovascular treatment”, “aortic rupture”, “blunt trauma”, “aortic dissection”, and “aortic pseudoaneurysm”. The search strategy was modified to meet the requirements of each database (e.g., truncation, Boolean operators, etc.).

Study selection: Two independent reviewers screened the titles and abstracts of all identified studies for potential eligibility. Full-text articles of selected studies were obtained and assessed for inclusion.

Data extraction: Data were extracted independently by two reviewers using a pre-defined data extraction form. The following information was collected from each included study: (1) Study design and year of publication; (2) Patient demographics (e.g., age, sex); (3) Details of the BTAI (e.g., injury grade); and (4) Primary and secondary outcomes (mortality, complications, need for surgery, long-term outcomes). We tabulated data on short-term mortality, aortic-related mortality (ARM), and the rate of intervention following initial NOM. Where available, we also noted progression or resolution of aortic pathology on imaging follow-up.

Confidence in cumulative evidence

We assessed the strength of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. The Grading of Recommendations, Assessment, Development and Evaluation system considers factors such as study limitations, consistency of results, directness of evidence, precision of estimates, and the risk of publication bias. This process was used to evaluate the overall quality of evidence for the primary and secondary outcomes.

RESULTS

Overview of all studies included

Our search identified approximately 700 studies, of which 49 were selected for review of the article, and 27 were chosen for inclusion (Figure 1). Data from these studies were included in Table 1. Twenty-five studies were retrospective in nature, with only two studies that were prospective. Twenty studies collected data from a single institute, while three collected patient data from multiple institutions. Four studies utilized large databases such as the National Trauma Data Bank, the Aortic Trauma Foundation, and the Vascular Quality Initiative. The majority of the studies were based in the United States (17 of 27, 62.9%), Canada (2 of 27, 7.4%)[5,6], and Spain (2 of 27, 7.4%)[13,14] along with single studies from Austria[15], China[16], Japan[17], Qatar[18], South Korea[11] and one international study[19]. There was significant variation in the number of patients reported in each study. The studies with the seven largest sample sizes were either based on registry data or from multiple participating hospitals[3,12,19-23]. The only study by McCurdy et al[24] from Indiana University included more than 200 patients. All studies except two reported both NOM as well as intervention; Ott et al[6] reported BTAIs managed with stent and open operation, and Yadavalli et al[22] analyzed the Vascular Quality Initiative, which accumulates data from operative patients only[22,23].

Figure 1 Prisma diagram showing the identification of studies included in our review.

Table 1 Details of studies included in our review.

Ref.	Design	Demographics	Details of BTAI	Management strategies	Primary and secondary outcomes
Kepros et al[29], 2002	Retrospective, institutional	N = 5, mean age 365 years; 40% male	Aortic intimal tear (no further detail or grading)	Non-operatively	No mortality observed; 0%
Ott et al[6], 2004	Retrospective; institutional	N = 18; n = 12 open vs n = 6 endo; median 43.5 endo vs 31.5 open, P = 0.18; 58.3% male open vs 66.7% male endo	Not mentioned	Endovascular vs open	In-hospital mortality: 0% endo vs 16.7% open, P = 0.53; paraplegia: 0% endo vs 16.7% open, P = 0.53; RLN injury: 0% endo vs 8.3% open, P = 1.00; ARDS: 0.0% vs 8.3%, P = 1.00; sepsis: 0.0% vs 41.67%, P = 0.11; MI: 0.0% vs 16.67%, P = 0.53; tracheostomy: 16.67% vs 33.33%, P = 1.00; arrhythmia: 33.33% vs 16.67%, P = 0.57; PE: 16.67% vs 8.33%, P = 1.00
Hirose et al[1], 2005	Retrospective, institutional data	N = 7; age 48.7 ± 22.7 years; 42.9% male	3/7 intimal flap; 4/7 pseudoaneurysm	Non-operative	In-hospital mortality 14.2%; five-year survival 71.4%; of those that survive, 50% had stable disease, 50% had resolution
Stampfl et al[15], 2006	Retrospective, institutional	n = 12; conservative (ages 41 and 76); surgery [age 30 (20-58)]; stent [age 47 (20-74)]	Local dissection, n = 8; contained rupture, n = 4	Conservative (n = 2); surgery n = 5 (4 for rupture, 1 for dissection; stent n = 5	No mortality in any group; surgery group: One return to OR; EVAR: One endoleak at 2 days, stented; no aortic reintervention in other patients or groups; no endoleaks in follow-up, mean follow-up 63 months (5-108)
Arthurs et al[3], 2009	Retrospective, NTDB	N = 2402; age 41 ± 20 years; 42% male; NOM: n = 1642; age 42 ± 21 years; OAR: n = 665; age 39 ± 18 years; TEVAR: n = 95; age 41 ± 21 years	Data not available	68% non-operative; 28% open; 4% endovascular	30-day Mortality: 6.5% non-op vs 19% open vs 18% endovascular, P < 0.05; paraplegia: 0.3% vs 2% vs 1.6%; ARDS: 4% vs 7% vs 2%, P < 0.05; PNA 9% vs 18% vs 12%, P < 0.05; myocardial infarction: 22% vs 25% vs 4%, P < 0.05; acute renal failure: 3% vs 6% vs 10%, P < 0.05; stroke 02% vs 0.6% vs 1.6%, P = NS; ICU LOS: 11.5 ± 13 days vs 12 ± 12 days vs 13 ± 11 days, P = NS; hospital LOS: 12 ± 19 days vs 19 ± 20 days vs 23 ± 23 days, P < 0.05
Caffarelli et al[30], 2010	Retrospective; institutional	N = 53; Non-operative: n = 29; age 45 ± 15 years; 69.0% male; operative: n = 24; age 46 ± 20 years; 75% male	Non-op: 6 intimal injury; 2 IMH; 19 PSA	All non-op	93% survival; no aortic deaths; 1 failed non-op; 2 had delayed repair at OSH after discharge; follow-up mean 107 days; median 31 days; 21 (78%) stable injuries; 5 (18%) complete resolution; 1 (4%) PSA progression
Mosquera et al[13], 2011	Retrospective; institutional	N = 37 (conservative; age 44.2 ± 19.3) vs 22 surgical (age 30.8 ± 9.8) vs 7 endo (age 44.9 ± 13.8)	Transection: 24.3% conservative vs 86.4% surgical vs 85.8% endovascular; conservative: 40.5% IMH; 27.1% partial intimal tear; 8.1% PSA		In-hospital mortality: 21.6% conservative vs 22.7% surgical vs 14.3% endovascular (P = 0.57); aortic-related complications: 100% vs 0% vs 0%, P < 0.001; 1-year survival: 75.6% vs 77.2% vs 85.7%; 5-year survival: 72.3% vs 77.2% vs 85.7%, P = 0.59; no 10-year survival in endo group (suggests that long-term durability not known)
Paul et al[28], 2011	Retrospective; institutional	N = 47; (n = 15; 41.5 ± 13.9; 66.6% male non-op) vs operative (n = 19, open, 44.5 ± 23.7, 62% male; n = 13, endo, 45.2 ± 20; 79% male)	Operative repair; non-op; 2 false on angion; 2 PSA and 11 intimal tear	Non-op; 2 false; 5 resolved; 8 stable	Mortality: 10.6%; 5/32 in operative vs 0% in non-operative; follow-up imaging: Non-operative; 2 aortogram (-); 5 resolved; 8 stable
Mosquera et al[14], 2012	Retrospective; institutional	N = 52; 9 patients MAI; 43 SAI	No formal grading; intimal tear < 10 mm MAI; rest SAI; PSA in SAI	9 MAI; 100% conservative; 43 SAI (26 conservative; 9 open; 8 TEVAR)	In-hospital mortality: 22.2% MAI vs 30.2% SAI, P = 0.94; ICU LOS: 17.2 ± 16 days MAI vs 18.5 ± 14.2 days SAI, P = 0.81; one-year mortality 77.8% vs 69.6%, P = 0.46; five-year mortality: 77.8% vs 63.6%, P = 0.46; MAI: 6/7 resolution; 1 developed PSA
Kidane et al[5], 2013	Retrospective, institutional	N = 59; non-op 43.4 (14.5) vs TEVAR 43.2 (21.8); non-op 53.6% male vs TEVAR 80.0%	Grades 1: 14 (27.0%); grade 2: 1 (1.9%); grade 3: 35 (67.3%); grade 4: 2 (3.8%)	Non-operative vs TEVAR; grade I: 13 NOM, I TEVAR; grade II: 1 NOM; grade III: 12 NOM, 23 TEVAR; grade IV: 2 TEVAR	Mortality: Non-operative 428% vs TEVAR 20.7% (not stratified by treatment type in each grade); grade I: 21.4% mortality; grade II: 0% mortality; grade III: 37.1% mortality; grade IV: 50% mortality
Rabin et al[27], 2014	Retrospective; institutional	N = 97; 31 grade I; 35 grade II; 24 grade III; 7 grade IV		Grade I: 28/31 MM; 3 TEVAR; grade II: 13 MM; 11 TEVAR; grade III: 4 MM; 18 TEVAR; 2 open; grade IV: 5 open; 2 TEVAR	Grade I mortality: 10%; grade II: 20%; grade III: 21%; grade IV 29%; grade I: MM: 14.2% mortality vs 0% TEVAR; grade II: MM 46.2% mortality vs TEVAR 4.5% mortality; grade III: 5.6% TEVAR vs 0% OAR; grade IV: 50% TEVAR vs 80% OAR; follow-up: Grade I: 11 resolved; 5 unchanged; 2 small increases in injuries but no intervention (no aortic-related deaths, ruptures, complications); Grade II: 5 unchanged; 1 subsequent elective repair
DuBose et al[20], 2015	Retrospective; multi-institutional	N = 382; NOM, n = 123; age 447 ± 18.0 years; 32.5% male; operative, n = 259; age 404 ± 17.6 years; 24.7% male	Grade 1, 94; grade 2, 68; grade 3, 192; grade 4, 28	Grade I: 76.6% NOM vs 5.3% OAR vs 18.1% TEVAR; grade II: 27.9% NOM vs 7.4% OAR vs 64.7% TEVAR; grade III: 12.5% NOM vs 21.9% OAR vs 65.1% TEVAR; grade IV: 25.0% NOM vs 32.1% OAR vs 42.9% TEVAR	NOM: 32%, 2 failures(1 grade I, 1 grade III); open repair in 61 patients (16%); TEVAR was done in 198 patients (52%). 6 patients of TEVAR failed, required 2 rpt TEVAR and 4 open repairs; overall in-hospital mortality 18.8% (NOM: 9.8%, OR: 13.1%, TEVAR: 2.5%); TEVAR was protective (P = 0.03); Aortic-related mortality 6.5%; 9.8% in NOM vs 5.0% P = 0.12; managed NOM grade I: 76.6%, grade II: 27.9%, grade III: 12.5%, grade IV: 25%. Failure rates: Grade I: 1.4%, grade II: 0%, grade III: 4.2%, grade IV: 0%; Managed w/TEVAR: Grade I: 18.1%, grade II: 64.7%, grade III: 65.1%, grade IV: 42.9%; failure rates: Grade I: 0%, grade II: 2.3%, grade III: 2.4%, grade IV: 16.7%
Gandhi et al[7], 2016	Retrospective, institutional	N = 35 (17 TEVAR vs 18 NOM); 44 (23) TEVAR vs 47 (20) NOM; 64.7% male TEVAR vs 55.6% male non-op	Grade 3	TEVAR vs non-operative	In-hospital mortality: 11.8% TEVAR vs 27.8% non-op, P = 0.402; aortic-related death 0% vs 6%, P = 1.00; any complications: 64.7% vs 50.0%, P = 0.728; AKI: 23.5% vs 22.2%, P = 1.00; PNA: 29.4% vs 22.2%, P = 0.711; respiratory failure: 17.6% vs 5.6%, P = 0.338; UTI: 17.6% vs 5.6%, P = 0.338; aortic injury; resolved/improved: 92.9% vs 87.5%, P = 0.674; worsened: 7.1% vs 12.5%
Tanizaki et al[17], 2016	Retrospective; institutional	N = 18; age 58.2 years (24-88); 66.7% male	Grade III: 18 (100%)	Initial NOM for all	22% mortality; 0% ARM; 14 patients followed non-operatively up for an average of 40.9 months; six grade III injuries were resolved; six grade III injuries were unchanged but did not require intervention; two patients in grade III had progression of pseudoaneurysm; 2/18 NOM required repair
Shackford et al[21], 2017	Retrospective; multi-institutional	255 patients total, TEVAR n = 176 (68%), age 46 years (28-60), 71% male; open n = 28 (10.8%), age 29 years (19-51); 71.4% male; NOM n = 51 (19.7%); age 42 (28-54); 64.7% male	No grading described		The overall In-hospital mortality was 5.9% (TEVAR 5.7%, Open 10.7%, NOM 3.9%. P = 0.535); 1 ARM in the TEVAR group; regarding the primary outcome of mortality, including In-hospital and post-discharge deaths, there was no significant difference between the three groups (TEVAR n = 12, 6.8%, Open n = 3, 10.7%, NOM n = 2, 3.9%, P = 0.485)
Spencer et al[26], 2017	Retrospective; institutional	N = 30; TEVAR 14; age 52 years (32-65); 79% male; NOM 16; 43 (37-66); 50% male	Grade I: 16; grade II: 14	Grade I: 50%TEVAR; 50% NOM; grade II: 8 NOM; 6 TEVAR	TEVAR 14% mortality vs NOM 6%, P = NS; failure rate for grade 1-2 patients were 0%; all patients in the TEVAR group showed stable stents with no leak; 2 patients in the NOM group had progression(One from grade 1 to grade 2, one from grade 2 to grade 3), resolution in 3 grade 1 patients, and the remainder of 11 patients were stable
Sandhu et al[31], 2018	Retrospective; institutional	N = 48; NOM; age 37.5 ± 15.1 years; 70.8% male; TEVAR grade II: 23; age 40.2 ± 14.3; 82.6% male	Grade I: 26; grade II:45	Grade 1 26 NOM; grade II: 48.9% NOM vs 51.1% TEVAR	NOM: Overall 42% mortality (3.9% grade I; 4.6% grade II; 0% ARM); 71% had follow-up data; 84% resolved; 16% persistent injury; median injury resolution time was 39 days for grade 1 and 62 days for grade 2; TEVAR: 0% 30-day mortality
Gaffey et al[4], 2019	Retrospective, institutional	N = 15; age 45 ± 20.6 years; 60% male	Grade II	Non-operative	30-day mortality: 1/15; Five-year mortality: 2/15; follow-up CT 69 months (7-138); no repair performed; resolution: 73.3%; no change 26.7%
Dubose et al[19], 2021	Prospectively collected; multi-institutional; registry	N = 296; age 44.5 ± 18 years; 76% male; NOM: n = 83 (28.0%); OAR n = 6 (2.0%); TEVAR n = 173 (58.4%)	Grade I n = 67 (22.6%), grade II n = 52 (17.6%), grade III n = 140 (47.3), grade IV n = 37 (12.5%)	Most of the patients underwent TEVAR (58.4%), Medical Management (28.0%), and open repair only 2%; I: 91% MM; 9% TEVAR; II: 61.5% MM; 38.5% TEVAR; III: 11.4% MM; 1.4% open; 86.4% TEVAR; IV: 2.7% MM; 10.8% open; 70.3% TEVAR	Overall mortality was 14.2% (42/296) (Table 1), with ARM at 4.7% (14/296)
					For grade 1 and 2 patients, 59.7% managed medically, and 40.3% underwent TEVAR. No significant difference in aortic-related mortality for grade 1 and 2 injuries; I: 7.5% overall mortality; 1.5% ARM; II: 17.3% mortality; 1.9% ARM; III: 10% mortality; 1.4% ARM; IV: 37.8% mortality; 27.0% ARM
McCurdy et al[24], 2020	Single center; retrospective	N = 229; age 45.8 ± 19.7 years; 70.3% male; TEVAR: n = 61; 45.4 ± 15.7; 68.9% male; OAR: n = 66; 40.6 ± 20.0; 75.8% male; NOM: n = 102; 49.5 ± 19.7; 67.7% male	I: 69 (30.1%); II: 19 (8.3%); III: 69 (30.1%); IV: 72 (31.4%)	TEVAR vs OAR vs NOM; I: 5 vs 12 vs 52; II: 5 vs 1 vs 13; III: 29 vs 19 vs 21; IV: 22 vs 34 vs 16; overall: 44% NOM, 27%; TEVAR, and 29% OAR	Overall, 30-day mortality was 22%; NOM 30-day mortality: 8% for grade 1, 15% for grade 2, 48% for grade 3, and 94% for grade 4; TEVAR: 16% for grade I/II and 0% for grade III/IV; NOM 30%, 8.2% for the TEVAR group, and 21% for open surgery group
Madigan et al[25], 2022	Retrospective; institutional	N = 176; NOM: n = 64; age 39 years (26-58); 28.1% female; TEVAR; n = 112; age 39 (26-58) years; 24.1% female	Grade I n = 36; grade II n = 24; grade III n = 115; grade IV n = 1	63.6% selected for TEVAR; grade I: 1/36; grade II 9/24; grade III 101/115; grade IV 1/1	30-day morbidity: 44.6% NOM vs 48.7% TEVAR, P = 0.64; 1-year mortality: 1.8% NOM vs 3.1% TEVAR, none of the NOM patients had progression; 44% resolution at follow-up; complete resolution of the aortic injury was seen in 28.6% of the grade 1 injuries and 20% of the grade 2 injuries at 30 days; remainder were stable; no progression 14 of grade 3 patients were treated NOM, most common reason to manage NOM was smaller size of PSA < 8 m without presence of peri-aortic hematoma, without proximal zone (Zone 0-1) lesion, and injuries in patients at extremes of age (< 18 or > 80). None of these lesions had progressed during follow-up, and one of the lesions resolved at 2-year follow-up
Sun et al[16], 2022	Single-center 10-year retrospective study between 2013 and 2022	N = 72	Grade 1 = 1 (1.4%); grade 2 = 17 (23.6%); grade 3 = 52 (72.2%); grade 4 = 2 (2.8%)		Total 72 patients, 60 patients with/ TEVAR, 8 NOM, 4 open surgery; total all-cause mortality was 12.5%, aortic-related mortality was 4.2%; TEVAR patients were grade 2 ( n = 15) and 3 (n = 45), grade 3 patients had a higher rate of ICU admission (0% vs 13.3%) and similar in-hospital mortality (1.7% vs 5%)
Al-Thani et al[18], 2022	Retrospective observational study between 2000-2020; single center	N = 87; NOM: Age 40.6 ± 16.4 years; 97.1% male; OAR: Age 37.1 ± 10.9 years; 47.4% male; TEVAR: 34.1 ± 13.8; 84.8% male	Grade 1 10 (11.5%); grade 2 12 (13.8%); grade 3 36 (41.4%); Grade 4 29 (33.3%)	40% NOM n = 35; 60% treated operatively n = 52; TEVAR 33 patients (63.5%); open surgery 19 patients (36.5%); grade I: 10 NOM; grade II: 12 NOM; grade III: 4 NOM vs 10 OAR vs 22 stent; grade IV: 9 NOM vs 9 OAR vs 11 stent	Overall, in-hospital mortality was 25.3%; significantly higher in-hospital mortality in the conservative group (40%), compared to open surgery (31.6%) and TEVAR (6.1%); TEVAR patients n = 33; grade I: 0% mortality; grade II: NOM 25% mortality; grade III: 50% NOM vs 20% OA vs 45% stent; grade IV: 100% NOM vs 44.4% OAR vs 9.1% stent
Arbabi et al[12], 2022	Prospective, multi-institutional; aortic trauma foundation	N = 432; NOM: n = 114; 38.5 (29); 69.3% male; intervention; n = 318, age 45 years (IQR 29); 78.3% male	Grade I 102; grade II 62; grade III 221; grade IV 47	114 patients underwent MM; 68 (59.6%) grade 1, 27 (23.7%) grade II, 18 (15.8%) grade III and 1(0.9%) grade IV; intervention: Grade I 34 (10.7%), grade II 35 (11.0%), grade III 203 (60.8%), grade IV 46 (14.5%)	12/114 required intervention; with 11 undergoing TEVAR and 1 open; grade I 1.5% failure rate; grade II 0% failure rate; grade III 55.5% failure rate; grade IV 100% failure rate; 30-day mortality rate of 1.7%; in-hospital mortality rate of 7.9%; no aortic-related mortality
Ye et al[11], 2022	Retrospective, institutional	N = 12, age 60 (16.1) years, 50% male	Grade 2 n = 2; grade 3 n = 10	NOM: n = 7; TEVAR n = 5; median 2 days	Mortality: 0% vs 40%, P = 0.182; LOS: 41.5 (17.5-69.0) vs 3.0 (1.5-38.5), P = 0.177
Yadavalli et al[22], 2023	Retrospective cohort, collected data from VQI, between 2013 to 2022	N = 1311	Grade 1 = 106 (8%); grade 2 = 244 (19%); grade 3 = 741 (57%); grade 4 = 220 (17 %)	All patients underwent TEVAR	Primary outcomes were peri-op (within 30 days) and 5-year mortality; higher grades with higher mortality overall (grade 1: 6.6%, grade 2: 4.9 %, grade 3: 7.2%, grade 4 14%); 5-year mortality rates were higher with grade 4 as well. (grade 1 11%, grade 2: 10%, grade 3 11%, and grade 4: 19%)
Golestani et al[23], 2024	Retrospective analysis of Aortic Trauma Foundation (Multicenter Registry)	N = 269	Grade 1 186; grade 2 83	218 patients Non-operative; 51 TEVAR	There was a significant difference in mortality between NOM alone and TEVAR (8% vs 18% P = 0.009); patients with/TEVAR increased incidence of DVT( 12% vs 1%, P = 0.002); hospital and ICU length of stay were not different

RLN: Recurrent laryngeal nerve; ARDS: Acute respiratory distress syndrome; MI: Myocardial infarction; PE: Pulmonary embolism; NOM: Non-operative management; OAR: Open aortic repair; TEVAR: Thoracic endovascular aortic repair; PNA: Pneumonia; NS: Not significant; ICU: Intensive care unity; LOSLength of stay:; IMH: Intramural hematoma; PSA: Pseudoaneurysm; OSH: Outside hospital; MAI: Minimal aortic injury; SAI: Significant aortic injury; AKI: Acute kidney injury; UTI: Urinary tract infection; CT: Computed tomography.

Demographics and BTAI grading

Basic demographics, such as age and sex of participating patients, were included in almost all studies and are included in Table 1 where available. Only sixteen studies adhered to SVS reporting standards for classification of BTAI. Three studies did not provide any description of the BTAIs reported[3,6,21]. Of the sixteen studies that adhered to SVS standards, nine studies included patients with all BTAI grades[5,12,16,18-20,22,24,25]. Three studies included patients with grade I and II BTAI only, while one study focused on grade II and III BTAI[11,21,23,26]. Gandhi et al[7] and Tanizaki et al[17] included only grade III BTAI, while Gaffey et al[4] included only grade II BTAI. Eight studies utilized non-standardized reporting standards for describing BTAIs[1,13-15,27-30]. Kepros et al[29] described their sample as patients with aortic intimal tear, while Stampfl et al[15] classified them as local dissections and contained rupture. Rabin et al[27] utilized a non-standardized grading system for classifying BTAI. Other authors classified BTAI using broad categories such as intimal tear, intramural hematoma, length of intimal disruption, and pseudoaneurysm[1,13-15,28-30].

Outcome of interest: Mortality

A total of 2792 patients were managed non-operatively, and 3698 patients received intervention as the initial management. Mortality was the most frequently reported outcome across the studies included. Amongst authors that did not provide any distinct BTAI classification, Ott et al[6] reported a higher mortality in patients undergoing open repair compared with endovascular repair (16.7% open vs 0.0% endovascular, P = 0.53), consistent with Arthurs, who also noted significantly lower mortality in the NOM group (6.5% NOM vs 19% open vs 18% endovascular, P < 0.05)[3,6]. Conversely, Shackford et al did not note any difference in mortality across these groups (3.9% NOM vs 5.7% TEVAR vs 10.7% open aortic repair, P = 0.535)[21].

Stampfl et al[15] and Kepros et al[29] did not report any mortality across their study samples of BTAI patients. Hirose et al[1] did reported a 14.2% in-hospital mortality rate in their study. All deaths occurring in Caffarelli et al’s analysis were prior to the decision to intervene vs manage conservatively[30]. Mosquera et al[13] found a trend towards a higher rate of mortality in the significant aortic injury patients compared with minimal aortic injury (30.2% vs 22.2%, P = 0.94), however, in their second analysis, did not find any differences across different treatment modalities (21.6% NOM vs 22.7% open vs 14.3% endovascular, P = 0.53)[13,14]. Rabin et al[27] did find increasing mortality with higher grade of injury, and in the data on grade II BTAI, they reported 46.2% mortality with NOM compared with 4.5% mortality in the TEVAR group. There were no patients undergoing NOM in the grade III or grade IV group.

Although some studies followed SVS standards for BTAI grade classification, their reported outcomes were not stratified by both grade and treatment type. These studies did demonstrate a trend of increasing mortality with increasing grade[5,19,20,25]. Of note, in all of these studies, the ARM was minimal, with most deaths being attributed to other traumatic causes. Only DuBose et al[19] reported ARM by BTAI grade, and showed a very high proportion of ARM in grade IV injury (27.0% in grade IV compared with 1.4%-1.9% in grades I to III). Yadavalli et al[22] found a higher mortality rate with increasing BTAI grade in their Vascular Quality Initiative analysis of post-stent patients (Grade I 6.6% vs grade II 4.9% vs grade III 7.2% vs grade IV 14.0%, P = 0.003). Authors who analyzed only low-grade BTAI (I and II) found mortality rates of 4.2% to 8.0% in the non-operative arm and 14%-18% in the endovascular arm[4,23,26,31]. For grade III BTAI, in-hospital mortality ranged from 22% to 28% in the non-operative group and was 12% in the TEVAR group[7,17].

Outcome of interest: Intervention after medical management

Some studies also reported rates of unplanned intervention for BTAI patients after failure of medical management. Both endovascular and surgical repair techniques were employed after the initial trial of NOM. Arbabi et al[12] did not define their criteria for repair, but Tanizaki et al[17] and DuBose et al[20] selected NOM patients who had progression on imaging for repair. DuBose et al[20] reported very low failure rates across all BTAI grades (grade 1: 1.4%, grade 2: 0%, grade 3: 4.2%, and grade 4: 0%), however Arbabi et al[12] found very high rates of intervention among high-grade BTAI patients (Grade I: 1.5%, grade II: 0%, grade III: 55.5%, and grade IV: 100%)[12,20]. Spencer et al[26] and Rabin et al[27] found very low intervention rates in their series of low-grade BTAI patients, 9.1% and 0% respectively. Per Tanizaki et al[17], 11% of grade III BTAI patients required repair after follow-up assessment.

Outcome of interest: Resolution of BTAI on follow-up imaging

Only 11 of the 27 studies had any imaging follow-up after the initial hospitalization. Most patients had stable or resolving disease on follow-up. Follow-up duration varied widely. Spencer et al[26] only followed patients till discharge, while other groups, such as Caffarelli et al[30] and Paul et al[28], had up to one year of imaging follow-up[1,26,28,30]. Few authors had an average follow-up in years[1,7,15,17,25]. Hirose et al[1] found that among survivors, 50% had stable BTAI while the rest had resolution of injury. Stampfl et al[15] did provide data on the lack of endoleaks on follow-up, but did not comment on BTAI grade. Among authors that did not adhere to SVS reporting standards, most patients had stable disease on follow-up, some had resolution of BTAI, and a small percentage experienced progression of disease, ranging from 0% to 14%[14,27,28,30]. In their studies pertaining to grade I and II BTAI, only Gaffey et al[4] found a 12.5% progression of disease, while Spencer et al[26] and Sandhu et al[31] did not find any progression. Resolution rates varied as well, with Gaffey et al[4] and Sandhu et al[31] reporting rates of 73% to 84% of resolution, while Spencer et al[26] reported only 18.8% resolution. Gandhi et al[7] and Tanizaki et al[17] found similar incidence of progression of pseudoaneurysm on imaging follow-up, 13% and 11% respectively.

DISCUSSION

Our review of the literature collected the published data over the past two decades in the management of BTAI. We evaluated multiple studies and included 7490 patients who were treated non-operatively or with endovascular or surgical techniques. Firstly, the data showed that low-grade BTAI could be managed non-operatively with lower mortality; however, higher-grade BTAI was associated with greater mortality. Secondly, even after NOM, the rates of delayed intervention were low for grade I and II BTAI, and variable for grade III BTAI. Lastly, limited data were available on imaging follow-up, but most low-grade I/II lesions did not progress, with a small percentage even undergoing resolution.

Given the high-energy mechanisms associated with BTAI, other injuries are frequently present and may confound the mortality from the aortic pathology itself. It is well-reported that this disease process is the second most common cause of death associated with blunt trauma[8]. Given that lower mortality rates were observed with endovascular repair, there has been a shift from surgical repair to less invasive options over the past two decades as endovascular therapies are increasingly adopted into the practice pattern of vascular surgeons. In a similar trend, as the spectrum of disease has been more clearly defined into varying grades, medical management has also been shown to be successful for select patients. In our review, we noted that more dated papers did not utilize standardized terminology to describe the injuries, and classified patients into categories such as “minimal aortic injury” and “significant aortic injury”[14]. Other characteristics, such as intimal tear, intimal disruption, intramural hematoma, and localized dissection, have been used without any consistent definition[1,6,15,29]. While a large volume of data may have been published on the matter, our study showed that only sixteen of the twenty-seven studies included adhered to SVS reporting standards.

In our review, while mortality did increase with grade, lower rates of in-hospital mortality were observed in NOM compared with surgical or endovascular repair in low-grade BTAI. Earlier studies did note limited mortality with NOM; however did not stratify by grade[21]. Among analyses stratified by BTAI grade, higher mortality was observed in higher grade injury as expected across all treatment groups[20,22]. Several authors showed that for grades 1 and 2 BTAI, mortality rates were lower among the NOM group, ranging from 4.2% to 8.0%, compared with the endovascular group, with rates of 14% to 18%[4,23,26,31]. A few studies also explored NOM for grade III BTAI or pseudoaneurysm. Gandhi et al[7] showed an 11.8% in-hospital mortality in the TEVAR group compared with 27.8% in the NOM group; however, this did not meet significance. Tanizaki et al[17] only studies grade III injuries that were managed non-operatively and demonstrated an in-hospital mortality rate of 22%, but deaths were attributed to other non-aortic causes, suggesting that there is a role for endovascular management in this subgroup. Harris et al[32] in their review of traumatic aortic pseudoaneurysm, found that factors such as the diameter ratio may be used to predict stability and safety of NOM.

NOM for BTAI is associated with intensive care unit stay, strict blood pressure monitoring and control, and follow-up imaging. Progression of aortic injury despite rigorous blood pressure control, onset of hemodynamic instability, or development of symptoms may lead the team to intervention. Some patients may require intervention after a short trial of medical management. Per DuBose et al[20] and their review of multi-center data, less than 5% of patients in any grade required delayed repair, while in contrast, Arbabi et al[12] showed a grade-dependent increase in failure rates. While all authors who had sufficient follow-up found low rates of repair needed in grade I and II BTAI after NOM, a wide range of intervention rates were reported for grade III BTAI from 11% up to 55%[12,17]. Further data is needed to understand the natural history of the traumatic aortic pseudoaneurysm and factors that may influence growth or resolution.

Given the transient nature of the trauma population and several factors inhibiting follow-up, less than half of the reviewed studies included follow-up with CT imaging. Moreover, due to a lack of guidelines as well as limited understanding of the natural progression of non-operatively managed BTAI, there is significant variation in follow-up. Nonetheless, several studies demonstrated that there is a low rate of progression of BTAI that has been non-operatively managed. Even in older studies, such as those by Hirose et al[1] and Caffarelli et al[30], they reported 50% to 78% of patients had stable disease and 18% to 50% had resolution within the first year. Gandhi et al[7] showed a very low rate of worsening BTAI grade during treatment, with no difference by treatment arm (7.1% at 2.6 years follow-up in the TEVAR group vs 12.5% at 0.8 years in the NOM group, P = 0.674). In fact, both Madigan et al[25] and Sandhu et al[31] did not show any progression of low-grade BTAI on follow-up). Tanizaki et al[17] showed a very low rate of progression of grade III BTAI on follow-up, with only 2 of 14 available patients having worsening of the pathology. Overall, a percentage of patients exists who may experience worsening aortopathy after successful management, hence regular follow-up is necessary.

Limitations

Our study is limited in that it is a retrospective review of published data, and hence, there are differences in the patient populations being compared. Given that the published data is not necessarily stratified by grade, there is limited granular data related to grade II BTAI, and minimal data has been published focusing on grade III BTAI, strong recommendations cannot be made without larger studies. Moreover, given that we have included studies both before and after the SVS reporting guidelines were published, there is variation in the language used to describe BTAI. Not all studies defined the reason behind the provider’s decision to abandon medical management for endovascular or open repair. Given that most follow-up is per provider discretion and patient factors, imaging data after discharge is sparse. Lastly, given the heterogeneity of the studies included, meta-analysis was not conducted, limiting the statistical robustness of our findings.

CONCLUSION

This review article provides the most up-to-date literature. Currently literature supporting the NOM for low-grade BTAI (grades I and II) treatment. Current SVS guidelines recommend endovascular repair for grade III BTAI patients; however, a few studies showed that grade III BTAI can be managed non-operatively with active surveillance in a selected group of patients. Literature requires further studies to compare NOM vs endovascular repair in higher-grade BTAI population