Aneurysmal Disease

Long-term survival after descending thoracic and thoracoabdominal aortic aneurysm repair

OBJECTIVE

Patients with descending thoracic aortic aneurysms (dTAA) or thoracoabdominal aortic aneurysms (TAAA) often have a variety of medical comorbidities. Those that are deemed acceptable for intervention undergo complicated repairs with good early outcomes. The purpose of this study was to identify variables that were associated with mortality over time.

METHODS

This was a retrospective review of a prospectively maintained database at our institution from 1983 to 2015. Patients were included if they underwent open or endovascular repair for dTAA or TAAA. Patients were excluded if they were intervened on for traumatic transections. The primary outcome for the study was long-term survival. Secondary outcomes included aortic-related mortality. We had mortality and survival data on all patients.

RESULTS

A total of 946 patients met our study criteria with a median follow-up of 102.8 months (interquartile range [IQR], 58.9-148.2 months). The median age of the cohort was 71 years (IQR, 63-77 years) with the majority of patients being male (58.1%). The extent of TAAA pathology was as follows: type I (14.2%), type II (21.2%), type III (17.1%), type IV (26.2%), and dTAA (21.2%). A total of 147 patients (15.5%) had a prior dissection. The median diameter of aneurysm was 6.4 cm (IQR, 6.0-7.0 cm). A total of 158 patients (16.7%) underwent endovascular repair over the study period. Variables associated with mortality over time were age, surgical era, acute pathology, dissection, preoperative creatinine, and type IV TAAAs. In addition, experiencing the following complications in the postoperative period was associated with mortality over time: neurological, cardiac, and pulmonary. Aortic-related mortality was 2.1% (n = 20) over the study period. Patients who underwent endovascular repair for acute conditions had better long-term survival when compared with open repair. However, there were no differences in long-term survival between open and endovascular repair for nonacute cases. In addition, repair in the more modern era was associated with improved survival.

CONCLUSIONS

TAAAs can be repaired with reasonable perioperative mortality rates. Once patients undergo repair of their aneurysm, aortic-related mortality remains low. The addition of endovascular options has dramatically changed management of patients with dTAA and TAAA. Further, endovascular repair was associated with decreased perioperative mortality and significantly increased long-term survival in acute patients. Patients undergoing TAAA repair are generally considered high risk and therefore require extensive long-term follow-up for management of their comorbidities and complications, because these are the main contributors to mortality over time.

Outcomes of single physician-modified fenestrated stent grafts for endovascular repair of thoracic aortic lesions involving the distal aortic arch

OBJECTIVES

Our goal was to evaluate the outcomes of fenestrated thoracic endovascular aortic repair of thoracic aortic lesions involving the distal aortic arch using single physician-modified stent grafts.

METHODS

This single-centre, retrospective study included 58 consecutive patients (mean age, 57 ± 14 years; 11 women) who underwent fenestrated thoracic endovascular aortic repair for thoracic aortic pathologies involving the distal aortic arch using single physician-modified stent grafts between November 2015 and December 2018. Indications included complicated acute type B dissection or intramural haematoma with an unfavourable proximal landing zone (n = 49), type Ia endoleak subsequent to thoracic endovascular aortic repair due to acute type B dissection (n = 1) and distal arch degenerative aneurysms <15 mm from the left subclavian artery (n = 8).

RESULTS

The technical success rate was 94.8%. The 30-day mortality was 1.7%, and the perioperative ischaemic stroke rate was 1.7%. The incidence of perioperative complications was 10.3%. At a mean follow-up of 26.3 months (range, 7-44), all target vessels were patent. All-cause mortality was 5.2%. Estimated 1-, 2- and 3-year survival was 98.3 ± 1.7%, 96.4 ± 2.5% and 93.2 ± 3.9%, respectively.

CONCLUSION

The single fenestrated stent graft technique is feasible and effective for endovascular repair of thoracic aortic pathologies involving the distal aortic arch.

Early and mid-term results of endovascular treatment of thoracic aorta diseases: a single-center experience

We conducted an analysis to assess early and mid-term outcomes of patients after thoracic endovascular aortic repair (TEVAR) for type B thoracic aorta dissection, descending thoracic aneurysm, or traumatic aortic transection. From January 2016 through December 2018, twenty-seven patients (23 male, 4 female, mean age of 57 years) affected by type B dissection (n = 13 [48.2%]), thoracic aneurysm (n = 9 [33.3%]), and post-traumatic aortic isthmus rupture (n = 5 [18.5%]) were treated using TEVAR with and without left subclavian artery revascularization. All procedures were performed in a hybrid operating room using general (n = 12) or regional (n = 15) anesthesia. A combined brachial artery and bilateral femoral artery access was used in all patients. To achieve adequate proximal thoracic aorta landing zone length, coverage of the left subclavian artery with proximal endovascular plug occlusion was performed in 17 patients (62.9%); including 4 patients undergoing carotid-subclavian artery bypass before TEVAR stent-graft deployment. Primary procedural success rate was 96.3%; 1 patient had a Type Ib endoleak that was treated by distal stent graft extension. Four adverse outcomes occurred in the immediate postoperative period, including 2 cases of left upper arm acute ischemia (7.4%), ischemic stroke (3.7%), and asymptomatic iliac artery dissection (3.7%). During a mean follow-up of 18 months, no graft-related deaths or endoleak occurred. One patient developed symptomatic subclavian steal syndrome 1 month after operation and underwent a left carotid-subclavian artery bypass with symptom resolution. One patient died 6 months after TEVAR due to neoplasm. Our experience indicates TEVAR is a safe and less invasive alternative to open surgery for a spectrum of thoracic aorta diseases, especially for urgent conditions and in patients with high-risk surgical comorbidities.

Total Endovascular Aortic Arch Repair with Branched Graft

In selected cases, the utilization of branched endografts for the treatment of aortic arch aneurysms could be a safe and advantageous alternative to high-risk procedures such as open total aortic arch replacement or hybrid arch repair. We present the case of a 70-year-old man with saccular aneurysm of a bovine aortic arch which was endovascularly treated using a double-branched custom-made aortic endoprosthesis based on the Relay NBS (Non-Bare Stent) Plus platform intended for zone 0 deployment. The postoperative clinical course was uneventful. The postoperative computed tomography scan showed a good result of the implant. The patient was discharged 6 days after the procedure.

Management of the vertebral artery during thoracic endovascular aortic repair with coverage of the left subclavian artery

BACKGROUND

The application of thoracic endovascular aortic repair (TEVAR), a minimally invasive operation, in the aortic arch has been a challenge of cardiovascular surgery in recent years. This study aimed to investigate management of the vertebral artery with coverage of the left subclavian artery (LSA) during TEVAR.

METHODS

From January 2007 to September 2014 in the Department of Cardiothoracic Surgery at Wuhan General Hospital of Guangzhou Military Region, 160 patients underwent LSA closure or partial coverage during TEVAR of an aortic lesion near the LSA. The vertebral artery treatment, the reason for the surgical approach selection, and the prognosis were analyzed.

RESULTS

In 94 patients with partial LSA coverage during TEVAR, no treatment was provided for the vertebral arteries, revealing blood flow of the left vertebral artery forward into the skull after surgery. For 66 patients with full LSA coverage (closure) during TEVAR, right carotid artery-left common carotid artery bypass surgery was performed before TEVAR in ten patients, without any treatment for the vertebral artery, showing reverse blood flow of the left vertebral artery after surgery. Left common carotid artery-LSA bypass surgery was performed before TEVAR in four patients; right common carotid artery-left common carotid artery-LSA bypass surgery was performed before TEVAR in three cases, and 6 out of these 7 patients underwent proximal LSA ligation, showing no obvious blood flow in the left vertebral artery. The closure of the LSA aortic arch opening using an occluder was performed in one patient, preserving the forward blood flow in the left vertebral artery. Among the 160 patients in this study, postoperative recurrent laryngeal nerve injury occurred in one patient after right common carotid artery-left common carotid artery-LSA bypass surgery, and the remaining 159 patients had no significant severe complications or death within 1 postoperative month.

CONCLUSIONS

Appropriate management of the aortic arch branch vessels may expand the application of TEVAR to the aortic arch and reduce complications, especially for high-risk patients who have a difficult time tolerating thoracotomy.

Comparative study of abdominal and thoracic aortic aneurysms: their pathogenesis and a gingival fibroblasts-based ex vivo treatment

Aortic aneurysms (AAs) consist of slow proteolysis and loss of both collagen and elastin matrix in the aorta wall, leading to wall dilation, weakening and rupture in well-advanced lesions. This can occur in both abdominal aorta (Abdominal Aortic Aneurysm: AAA) and thoracic aorta (Thoracic Aortic Aneurysm: TAA). To date, no non-surgical therapy has been proposed to slow or stop AA progression. Previously published preclinical studies from our team using an aneurysm rabbit model showed a promising concept for treatment of AAs with gingival fibroblast (GFs) which are readily available cells. In this study, we investigated the possible tissue repair of human AAAs and TAAs using ex vivo models co-cultured with GFs. Histological analysis showed that TAA and AAA are two distinct pathologies. Both lesions presented destruction of the aorta wall, highly evidenced in AAA samples. The results have confirmed the presence of the bacterial Porphyromonas gingivalis (Pg) protein in all AAA samples, but not in TAA samples, indicating the possible role of an infectious factor in the developing and progression of AAA lesions compared to TAA. The co-culture of GFs with AA lesions shows increased expression of TIMP-1, the inhibitor of the aneurysm severity marker MMP-9. Our study indicates that GFs might ameliorate aorta wall reestablishment in both AA types by their regenerative and immunomodulatory capacities. It also demonstrates the possible infectious cause of AAA compared with TAA that may explain their different behavior.

Dissecting Thoracic Aortic Hematoma Masquerading as Blunt Force Injury of the Neck

Discoloration of the skin of the anterior and lateral neck may raise suspicion for blunt force injury, particularly cervical compression, in an unwitnessed death. We present a case of an elderly woman with an unwitnessed death at home which highlights an external examination finding of blue/purple discoloration of the skin of the neck and links this finding with those from internal examination at autopsy. Pertinent negatives include absence of conjunctival and mucosal petechiae, absence of cutaneous abrasions of the neck, and absence of contusions of the anterior neck musculature. This case illustrates a natural disease entity, spontaneous dissection of a thoracic aortic hematoma, masquerading as blunt force injury externally and highlights the importance of having an appropriate index of suspicion when triaging jurisdictional cases for postmortem examination to accurately determine cause and manner of death.

Outcomes of Thoracic Endovascular Aortic Repair and Subclavian Revascularization Techniques

BACKGROUND

Practice guidelines for management of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) are based on low-quality evidence, and there is limited literature that addresses optimal revascularization techniques. The purpose of this study was to compare outcomes of LSA coverage during TEVAR and revascularization techniques.

STUDY DESIGN

We performed a single-center retrospective cohort study from 2001 to 2013. Patients were categorized by LSA revascularization and by revascularization technique, carotid-subclavian bypass (CSB), or subclavian-carotid transposition (SCT). Thirty-day and mid-term stroke, spinal cord ischemia, vocal cord paralysis, upper extremity ischemia, primary patency of revascularization, and mortality were compared.

RESULTS

Eighty patients underwent TEVAR with LSA coverage, 25% (n = 20) were unrevascularized and the remaining patients underwent CSB (n = 22 [27.5%]) or SCT (n = 38 [47.5%]). Mean follow-up time was 24.9 months. Comparisons between unrevascularized and revascularized patients were significant for a higher rate of 30-day stroke (25% vs 2%; p = 0.003) and upper extremity ischemia (15% vs 0%; p = 0.014). However, there was no difference in 30-day or mid-term rates of spinal cord ischemia, vocal cord paralysis, or mortality. There were no statistically significant differences in 30-day or midterm outcomes for CSB vs SCT. Primary patency of revascularizations was 100%. Survival analysis comparing unrevascularized vs revascularized LSA was statistically significant for freedom from stroke and upper extremity ischemia (p = 0.02 and p = 0.003, respectively). After adjustment for advanced age, urgency, and coronary artery disease, LSA revascularization was associated with lower rates of perioperative adverse events (odds ratio = 0.23; p = 0.034).

CONCLUSIONS

During TEVAR, LSA coverage without revascularization is associated with an increased risk of stroke and upper extremity ischemia. When LSA coverage is required during TEVAR, CSB and SCT are equally acceptable options.

A rat model of aortic arch aneurysm with excellent survival

BACKGROUND

The complex mechanisms of aortic arch aneurysm have not been well studied. An animal model of aortic arch aneurysm would be beneficial to study this fatal disease. In this study, we tried to establish a rat model of aortic arch aneurysm by constricting the aortic isthmus.

METHODS

Forty-eight male Sprague-Dawley rats were randomly divided into three groups. Rats with no aortic isthmus constriction were assigned to group A (control group). The aortic isthmus was constricted to 1.5 mm in group B and to 0.8 mm in group C. The blood pressure of the rats was measured at 0, 1, 3 and 6 months after the operation. The diameter and wall thickness of aortic arch were measured at 3 and 6 months after surgery.

RESULTS

Compared to group A, group B showed no significant increase in blood pressure or aortic diameter after the operation. Compared to the control group, group B showed a marked increase in wall thickness at 3 and 6 months after surgery (p < 0.05). Compared to group A, group C showed significant increases in both blood pressure (p < 0.05) and aortic diameter (p < 0.05) after the operation. Group C also showed a more than 50% increase in wall thickness at 3 and 6 months after surgery (P < 0.05).

CONCLUSIONS

By constricting the aortic isthmus to 0.8 mm, a rat model of aortic arch aneurysm could be induced at 3 and 6 months after surgery.

Thoracic Aortic Rupture and Aortopulmonary Fistulation in the Friesian Horse

Aortic rupture in horses is a rare condition. Although it is relatively common in the Friesian breed, only limited histopathologic information is available. Twenty Friesian horses (1–10 years old) were diagnosed with aortic rupture by postmortem examination. Ruptured aortic walls were analyzed with histology and immunohistochemistry. Based on the histologic and immunohistochemical findings, these cases were divided into 3 groups: acute ( n = 4, 20%), subacute ( n = 8, 40%), and chronic ( n = 8, 40%). Features common to samples from horses in all groups included accumulation of mucoid material; disorganization and fragmentation of the elastic laminae; aortic medial smooth muscle hypertrophy; and medial necrosis of varying degrees, ranging from mild and patchy in the acute cases to severe midzonal necrosis in the chronic cases. Inflammation, most likely secondary to medial necrosis, varied from predominantly neutrophilic infiltrates in the media and periadventitial tissue in the acute group to the presence of mainly hemosiderophages in the periadventitial tissue in the chronic group. Medial fibrosis with aberrant collagen morphology was seen in the subacute group and, more commonly, in the chronic group. Only minimal changes were seen in the aortic vasa vasorum. Smooth muscle hypertrophy and accumulation of mucoid material were not related to the age of the lesions. The findings of this study suggest that a connective tissue disorder affecting elastin or collagen in the aortic media is potentially the underlying cause of aortic rupture in Friesian horses.