Intragraft Obstructive Thrombus Two Years After Endovascular Repair of Traumatic Aortic Injury: A Case Report and Review of the Literature

Introduction

Thoracic endovascular aortic repair (TEVAR) is the treatment of choice for blunt thoracic aortic injury (BTAI) and has proven to be a good alternative to open surgery. TEVAR requires less operation time, has fewer complications, can be used for relatively unstable patients, and is associated with a significantly lower mortality rate. Moreover, long term follow up data demonstrate low re-intervention rates and stentgraft failure.

Report

The case of a 21 year old man who sustained severe trauma, including a traumatic pseudoaneurysm of the descending thoracic aorta distal to the left subclavian artery in 2016, is presented. The patient was treated by TEVAR. Two years later, he presented with progressive paraplegia due to stentgraft occlusion occurring four days after a new high velocity motor vehicle accident. An axillofemoral bypass was performed to assure blood flow to the lower body. Two days later the stentgraft was removed via left thoracotomy and replaced by a Dacron graft. Gross examination showed severe thrombus formation at the proximal edge, and a thrombotic occlusion in the middle and distal third of the stent. After three months of hospitalisation the patient was discharged to a rehabilitation clinic with partial recovery of his paraplegia. As of June 2020, the patient was able to walk without assistance and his paraplegia improved with only loss of sensation of his lower legs.

Conclusion

A serious thrombotic complication two years after TEVAR is described. Although TEVAR is the currently preferred treatment for BTAI, more research is needed to examine the mechanisms behind this thrombotic complication and to elucidate whether TEVAR is definitive treatment or a “bridge to further surgery”. Smaller diameter stentgrafts, anticoagulation, regular (lifelong) follow up imaging, and prophylactic surgical conversion in (selected) patients might help to prevent this serious complication.

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Although thoracic endovascular aortic repair is the first choice treatment for blunt thoracic aortic injury, the cause of intragraft thrombus is unknown.

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Nine cases have been reported with thrombotic (near) occlusions of thoracic stentgrafts. This is the first reported total occlusion following a second trauma.

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Oversizing and trauma can potentially play a role in the formation and progression of obstructive thrombus in thoracic stentgrafts.

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Follow up is important to detect intragraft thrombus deposition and to prevent major complications by adjusting anticoagulation or performing prophylactic removal of thrombotic stentgrafts.

Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Endovascular aneurysm repair: state-of-art imaging techniques for preoperative planning and surveillance

Endovascular aneurysm repair (EVAR) represents one of the greatest advances in vascular surgery over the past 50 years. In contrast to conventional aneurysm repair, EVAR requires accurate preoperative imaging and stringent postoperative surveillance. Duplex ultrasound (DUS), transesophageal echocardiography, intravascular ultrasound, computed tomography (CT) and magnetic resonance (MR), each provide useful information for patient selection, choice of endograft type and surveillance. Today most interventionists and surgeons will rely on CT or MR to assess aortic morphology, evaluate access artery patency and locate side branch orifices. However, recent developments in cross-sectional imaging, including advanced image postprocessing, multi-modality image fusion and new contrast agents have resulted in improved spatial resolution for preoperative planning. Advanced reconstruction algorithms, like dynamic CTA and MRA, provide valuable information on dynamic changes in aneurysm morphology that might have an important impact on endograft selection. During follow-up, imaging of the graft and aneurysm is of utmost importance to identify patients in need of secondary intervention. This has led to rigorous follow-up protocols including duplex ultrasound and regular CT examinations. The use of these intense follow-up protocols has recently been questioned because of high radiation dose and the frequent use of nephrotoxic contrast agents. New imaging modalities like contrast enhanced DUS, dynamic MR and dual-source CT could reduce radiation dose and obviate the need for nephrotoxic contrast. Up-to-date knowledge of non-invasive vascular imaging and image processing is crucial for EVAR planning and is essential for the development of follow-up programs involving reduced risk of harmful side effects.

Wall Stress Analysis in Small Asymptomatic, Symptomatic and Ruptured Abdominal Aortic Aneurysms

OBJECTIVES

To evaluate the potential of wall stress analysis for the identification of abdominal aortic aneurysm (AAA) at elevated risk of rupture in spite of small diameter.

MATERIALS AND METHODS

Thirty patients with small AAA, 10 asymptomatic, 10 symptomatic and 10 ruptured, were included. Demographic data and results from physical examinations were recorded in a retrospective fashion. After CT-evaluation and the creation of a patient specific 3D model, wall stress was calculated using the finite element method.

RESULTS

No differences were observed in diameter between asymptomatic, symptomatic or ruptured aneurysms (5.1+/-0.2 cm vs. 5.1+/-0.2 cm vs. 5.3+/-0.2 cm respectively; p=0.57). Peak aortic wall stress at maximal systolic blood pressure is significantly higher in ruptured than asymptomatic aneurysms (51.7+/-2.4 N/cm(2) vs. 39.7+/-3.3 N/cm(2) respectively; p=0.04). Wall stress analysis at uniform blood pressure, performed to correct for higher blood pressure in the symptomatic and rupture group did not result in significant differences in peak wall stress (asymptomatic 31.7+/-2.3 N/cm(2); symptomatic 30.5+/-1.3 N/cm(2); rupture 36.7+/-4.0 N/cm(2); p=0.26).

CONCLUSIONS

Wall stress analysis at maximal systolic blood pressure is a promising technique to detect aneurysms at elevated aneurysm rupture risk. Since no significant differences were found at uniform blood pressure, the need for adequate blood pressure control in aneurysm patients is reiterated.

[Thromboprophylaxis in general surgical practices in the year 2004: perioperative use during hospitalisation, during out-patient care and following plaster cast immobilisation]

OBJECTIVE

To determine which thromboprophylactic modalities were used by general surgeons in the Netherlands; to check current clinical practice against national and international guidelines.

DESIGN

Descriptive.

METHOD

In April 2004 a questionnaire was sent to all 106 surgical practices in the Netherlands with questions regarding the use of thromboprophylaxis before, during and after various surgical interventions. Practice was compared with guidelines from the Dutch Institute for Healthcare Improvement CBO, the Dutch Surgical Association and the American College of Chest Physicians.

RESULTS

We obtained data from 92 (87%) surgical practices. Low molecular weight heparin was initiated before surgery by 92% of respondents. Risk factors such as age (72%) and prior venous thromboembolism (76%) played an important role in determining the thromboprophylactic protocol used. During hospitalisation, variations were seen primarily for operations performed on an out-patient basis: 61% of surgeons gave thromboprophylaxis in this setting. Prolonged thromboprophylaxis after hospital discharge was seldom administered. 54% of surgeons used prolonged thromboprophylaxis after surgery for hip or femur fractures. During cast immobilisation of the upper leg, 79% of all surgeons prescribed thromboprophylaxis.

CONCLUSION

Current practice regarding thromboprophylaxis during hospitalisation conformed consistently to the guidelines. The guidelines were followed moderately with regard to the use of prolonged thromboprophylaxis following hip fractures. In the absence of clear guidelines, there were striking differences among surgical practices regarding thromboprophylaxis during out-patient care and plaster cast immobilisation.