Potential long-term complications of endovascular stent grafting for blunt thoracic aortic injury

Thoracic endovascular repair for blunt traumatic thoracic aortic injury: Long-term results

OBJECTIVE

This study aims to evaluate the endoprosthesis complications in patients undergoing TEVAR for blunt traumatic thoracic aortic injury, through long-term clinical and diagnostic follow-up.

METHODS

During the study interval (November 2000-October 2020), a total of 38 patients (63% male; average age 37.5 years) with thoracic aortic injury underwent thoracic endovascular aortic repair. Patients underwent routine follow-up with clinical examination and radiological evaluation (CT-angiography or MRI-angiography plus chest radiograph), scheduled at 1 month, at 6 months (only in the cases of thoracic aortic dissection), at 1 year after the procedure and every 1 year thereafter.

RESULTS

Technical success was achieved in 38 procedures (100%). The TEVAR-related mortality rate was 0%. No immediate major complications related to the endovascular procedure were observed. The median duration of diagnostic follow-up was 80 months. A total of four procedure-related complications (10.5%) were identified at the follow-up. Three (7.9%) distal infoldings and collapses of the thoracic endoprosthesis and one (2.6%) type Ia endoleak were observed. No thrombosis of the prosthesis, nor signs of aortic pseudocoarctation were identified. No further complications related to endograft (endoleaks, infections, rupture, partial or complete thrombosis) occurred. No changes in the native aorta, stenosis, or increases in the endograft's diameters were observed. A total of 20 patients (52.6%) underwent MRI-angiography examinations, while a total of 34 patients (89.5%) underwent chest radiographs at the follow-up. In all cases, CT-angiography examinations were performed at the follow-up.

CONCLUSIONS

Procedure-related complications were observed within one year of TEVAR, limiting concerns related to the durability of the prosthesis. No morphological changes in the aorta were observed despite long-term follow-up. The consequences of lifelong surveillance in terms of radiation exposure deserve special consideration, especially in younger patients treated for TAI.

Thoracic endovascular aortic repair for traumatic aortic injuries: insight from literature and practical recommendations

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) for treatment of blunt traumatic aortic injuries (BTAIs) is nowadays the gold standard technique in adult patients, replacing gradually the use of open repair (OR). Although randomized controlled trials will never be performed comparing TEVAR to OR for BTAIs management, trauma and vascular societies guidelines today primarily recommend the former for BTAI patients with a suitable anatomy. The aim of this review was to describe past and recent data published in literature regarding pros and cons of TEVAR treatment in BTAI, and to analyze some debated issues and future perspectives.

EVIDENCE ACQUISITION

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Scale for the Assessment of Narrative Review Articles (SANRA) were used to obtain and describe selected articles on TEVAR in BTAI.

EVIDENCE SYNTHESIS

Young (<50 years) men were the most operated population. The use of TEVAR increased over the years, with a progressive reduction in mortality and overall postoperative complication rates when compared with OR. Lack of information remains about the percentage of urgent cases.

CONCLUSIONS

TEVAR is considered nowadays the treatment of choice in BTAI patients. In case of aortic rupture (grade IV) the treatment is mandatory, while intimal tear (grade I) and intramural hematoma (grade II) can be safely managed with no operative management (NOM). Debate is still ongoing on grade III (pseudoaneurysms). Unfortunately, several aspects remain not yet clarified, including disease classification, type and grade to treat, timing (urgent versus elective), priority of vascular injuries in polytrauma patients, and TEVAR use in pediatrics and young patients.

Open Conversion for Recurrent Endograft Occlusion after Endovascular Treatment of Blunt Traumatic Aortic Injury: A Peculiar Case Report

BACKGROUND

We report a rare case of delayed, symptomatic thoracic endograft thrombosis after the initial thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury which was successfully retreated with a redo TEVAR, followed by open conversion due to recurrent partial occlusion of the distal edge of the endografts.

METHODS

Two years ago, a 22-year-old man had undergone an emergency TEVAR for blunt thoracic aortic injury. A Zenith Cook 22 × 100 mm (Cook Incorporated, Bloomington, IN) endograft was used. Six months later, he underwent an emergency endovascular relining of the endograft using the same type of device. The multiorgan perfusion was completely restored except for the spinal cord injury. After 8 months, a recurrent partial occlusion of the distal edge of the second graft was documented. The thoracic aorta was replaced with a 22-mm silver-coated graft (Maquet Spain, SLU).

RESULTS

Histology examination showed a neointimal formation and thickening and fibrosis of the inner 1/3 of the media with loss of smooth muscle cells and increase of the elastic fibers.

CONCLUSIONS

The need for secondary interventions or open conversion because of potential complications after TEVAR for traumatic aortic injury is an additional consideration when weighing the risks and benefits of endovascular repair and subsequent surveillance strategies.

Effects of longitudinal pre-stretch on the mechanics of human aorta before and after thoracic endovascular aortic repair (TEVAR) in trauma patients

Thoracic endovascular aortic repair (TEVAR) has evolved as a first-line therapy for trauma patients. Most trauma patients are young, and their aortas are compliant and longitudinally pre-stretched. We have developed a method to include longitudinal pre-stretch in computational models of human thoracic aortas of different ages before and after TEVAR. Finite element models were built using computerized tomography angiography data obtained from human subjects in 6 age groups 10-69 years old. Aortic properties were determined with planar biaxial testing, and pre-stretch was simulated using a series of springs. GORE C-Tag stent-graft was computationally deployed in aortas with and without pre-stretch, and the stress-strain fields were compared. Pre-stretch had significant qualitative and quantitative effects on the aortic stress-strain state before and after TEVAR. Before TEVAR, mean intramural aortic stresses with and without pre-stretch decreased with age from 108 kPa and 83 kPa in the youngest age group, to 60 kPa in the oldest age group. TEVAR increased intramural stresses by an average of 73 ± 15 kPa and 48 ± 10 kPa for aortas with and without pre-stretch and produced high stress concentrations near the aortic isthmus. Inclusion of pre-stretch in young aortas increased intramural stresses by 30%, while in > 50-year-old subjects it did not change the results. Computational modeling of aorta-stent-graft interaction that includes pre-stretch can be instrumental for device design and assessment of its long-term performance, and in the future may help more accurately determine the stress-strain characteristics associated with TEVAR complications.

Experts' Results in Blunt Thoracic Aortic Injury are Reproducible in Lower Volume Tertiary Institutions. Early and Mid-term Results of an Observational Study

OBJECTIVES

The aim of this study was to evaluate the early and mid-term clinical results, the device performance, and the mid-term re-intervention rates of patients suffering blunt thoracic aortic injury (BTAI) managed by a multidisciplinary team in a low-volume BTAI centre.

METHODS

This was a retrospective observational study in a tertiary hospital setting. From December 2005 to March 2016, all patients over 18 years old admitted with BTAI were included in the study. No exclusion criteria were applied. The study data were collected and analysed retrospectively. Follow-up of survivors included computed tomography imaging 3 and 9 months post-procedure, then annually.

RESULTS

Twenty-eight patients were included in the study. Their mean age was 42 ± 16 years and 89% were male. A contained aortic rupture was diagnosed in 20 patients, a Stanford type B dissection in six, and intramural haematoma in two patients. Multidisciplinary evaluations were performed and an intervention was indicated in 25 patients (89%), four of whom died before the intervention. Nineteen patients underwent thoracic endovascular aortic repair of the descending thoracic aorta and two patients underwent a frozen elephant trunk procedure. The procedures were performed 0.7 ± 1.2 days after injury. All procedures were successful. There were no device related complications. The post-operative 30 day mortality was 5%, with one patient dying on the day of operation from other vascular injuries. The 30 day mortality of all patients was 18%. The median mid-term follow-up period was 786 days. All 30 day survivors survived the follow-up period. The mid-term imaging showed stable results in 19 patients. Two patients required frozen elephant trunk procedures after 240 and 681 days and both procedures were successful.

CONCLUSIONS

In a low volume centre, a multidisciplinary team using a standardised protocol with the endovascular first approach demonstrated excellent outcomes, similar to those of large centres. If the aortic trauma is adequately managed, the patient's outcome is closely related to the additional trauma.

Patient demographics and cardiovascular risk factors differentially influence geometric remodeling of the aorta compared with the peripheral arteries

BACKGROUND

Detailed knowledge of the dimensions and shape of the main arteries of the body and how they change with age and disease is important for understanding arterial pathophysiology and improving minimally invasive devices to treat arterial diseases. Our goal was to describe and compare geometric remodeling of the aorta and peripheral arteries in the context of patient demographics and cardiovascular risk factors.

METHODS

Three-dimensional reconstructions of computed tomography angiography scans were performed in 122 subjects 5-93 years of age (mean 47 ± 24 years, 64 M/58 F). Best-fit arterial diameters, lengths, and tortuosity for the principle named arteries in the chest, abdomen, pelvis, and upper thigh were measured, and multiple linear regression analysis was performed to examine how these morphologic parameters associate with patient demographics and risk factors.

RESULTS

Large elastic arteries increased their diameter, length, and tortuosity with age, whereas muscular arteries primarily became more tortuous. Demographics and risk factors explained >70% of the variation in diameters of the abdominal aorta, paravisceral aorta, and the aortic arch; and >75% of variation in tortuosity from the profunda femoris to the brachiocephalic artery. Male sex, larger body mass index, and hypertension contributed to larger diameters, whereas the presence of diabetes was associated with somewhat-straighter arteries. Overall, the effects of cardiovascular risk factors on geometric remodeling were small compared with those of demographics.

CONCLUSION

The geometry of the vascular tree is greatly affected by aging, demographics, and some risk factors. Elastic and muscular arteries remodel differently, possibly as the result of differences in their microstructure.

Intravascular ultrasound is a critical tool for accurate endograft sizing in the management of blunt thoracic aortic injury

BACKGROUND

Accurate measurement of true aortic luminal diameter (ALD) is critical for endograft sizing in endovascular treatment of blunt thoracic aortic injury (BTAI), but ALD is dynamic and changes with respect to patients' hemodynamic status. This study aimed to characterize how ALD at the time of diagnosis of BTAI compares with ALD at the time of endovascular repair and later at follow-up.

METHODS

This is an Institutional Review Board-approved, single-institution retrospective analysis of prospectively obtained data. Patients were included who presented between July 2007 and December 2012 with computed tomography angiography (CTA)-diagnosed BTAI; who underwent thoracic endovascular aortic repair (TEVAR); and who underwent preoperative CTA, intraoperative intravascular ultrasound (IVUS), and postimplantation CTA. Comparison measurements of the ALD were made among CTA and IVUS images at the level of the left subclavian artery (LSCA) and between initial CTA and postimplantation CTA at 10, 15, and 20 cm distal to the LSCA. Theoretical endograft sizes were determined and compared for each ALD at the LSCA.

RESULTS

Twenty-two patients were included in the analysis. Mean age was 38 ± 14 years (range, 17-61 years), with 82% men and mean Injury Severity Score of 43 ± 11 (range, 24-66). Mean time from emergency department admission to initial CTA was -1.2 ± 5 hours (range, -13 to 11.5 hours; negative time implies imaging at an outside facility before admission). Mean time from initial CTA to IVUS was 1.2 ± 1.4 days (range, 2.5 hours-5.7 days) and from IVUS to postimplantation CTA 33 ± 45 days (range, 17 hours-169 days). Overall, ALD measured by IVUS was significantly larger than that by initial CTA (Δ2.5 ± 3.1 mm; P < .05). ALD was also larger at 10, 15, and 20 cm distal to the LSCA in comparing the postimplantation CTA with the initial CTA (Δ2.4, 2.0, and 2.0 mm, respectively; all P < .05). More than half the devices would be sized differently with ALD measured by IVUS at the time of TEVAR vs initial CTA.

CONCLUSIONS

The ALD of patients with BTAI is significantly larger when it is measured by IVUS at the time of TEVAR compared with at the time of initial CTA. This difference in ALD may translate to undersizing of endografts used in TEVAR for BTAI. IVUS at the time of TEVAR provides a more accurate measurement of the actual ALD and should be used for endograft sizing for patients with BTAI.

One-year results of thoracic endovascular aortic repair for blunt thoracic aortic injury (RESCUE trial)

OBJECTIVE

One-year outcomes of the RESCUE trial (endovascular aortic repair using Valiant Captivia for blunt thoracic aortic injury) are reported.

METHODS

RESCUE is a prospective, nonrandomized, multicenter trial. Fifty patients with blunt thoracic aortic injury were enrolled between April 2010 and January 2012. One-year outcomes included secondary procedures, device-, procedure-, and/or aorta-related adverse events, and all-cause mortality.

RESULTS

Mean patient age was 40.7 ± 17.4 years; 76% of patients were male. Fifty-two thoracic stent grafts were implanted within a median of 1 day of injury. Seventy percent (35 of 50) of aortic injuries were grade III or higher, including 1 free rupture. The mean Injury Severity Score was 37.6 ± 14.3. Vascular access, device delivery, and deployment were successful in all patients. The left subclavian artery was completely covered in 40% (20 of 50) and partially covered in 18% of patients (9 of 50). There were no strokes or spinal cord injuries. Median procedure time was 90.5 minutes; median hospital stay was 11 days. All-cause mortality within 1 year was 12%. There were no conversions to open repair. Four patients (8%) had subclavian artery revascularization; 1 preoperatively; 3 others postoperatively on days 8, 36, and 103. There were no device-related adverse events. During follow-up, 1 patient (2%) had aortic-related and 9 patients (18%) had procedure-related adverse events.

CONCLUSIONS

TEVAR has favorable early midterm outcomes in the treatment of blunt thoracic aortic injury, and remains the treatment modality of choice. Longevity of the stent grafts in this young patient population has yet to be established.

Long-term outcomes after thoracic aortic surgery: a population-based study

OBJECTIVE

Long-term survival after aortic surgery has remained largely unexplored, despite suggestions of superior durability compared with endovascular techniques. The objective of the present study was to determine the long-term survival after open thoracic aortic surgery and to identify the predictors of mortality.

METHODS

The provincial database was accessed to identify all adult patients who had undergone primary open thoracic aortic surgery in British Columbia since 1993. Kaplan-Meier survival analyses were performed for the entire group and by year of surgery, urgency of surgery, and aortic segment requiring surgery. Multivariate analyses were performed to identify the predictors of mortality.

RESULTS

From January 1993 to June 2010, 1960 patients underwent primary open thoracic aortic surgery at 4 hospitals in British Columbia. Overall, the 30-day mortality was 9.1%, with a perioperative stroke rate of 5.8%. Long-term survival was 77.7%, 59.6%, and 44.7% at 5, 10, and 15 years, respectively. Subanalyses demonstrated improved long-term survival in the modern era; among patients undergoing elective aortic surgery; and among patients undergoing surgery on the ascending aorta or aortic root (P < .0001). The preoperative characteristics associated with decreased long-term survival included age older than 65 years, acute renal failure, dialysis, cerebrovascular accident, chronic obstructive pulmonary disease, peripheral vascular disease, and descending or thoracoabdominal aorta surgery.

CONCLUSIONS

Long-term survival after elective thoracic aortic surgery is excellent, with improved outcomes in the modern era. Several preoperative risk factors associated with decreased survival were identified, which could assist in risk stratification and patient selection. Finally, the long-term survival rates identified in the present study should serve as a benchmark to which new aortic interventions should be compared.