Endovascular repair of the ascending aorta: the last frontier.

Different pathologies of the ascending aorta (AA), including aneurysms, acute and chronic dissections, and pseudoaneurysms, have been treated with open surgical repair with very good results, especially at aortic centers of excellence. There is, however, a subset of patients for whom open surgery is considered to pose high or prohibitive risk. These patients can benefit from a less invasive approach with catheters and wires, percutaneous techniques and stent grafts. However, the existing technology was developed to treat descending thoracic aortic pathologies; it is not approved for use in the AA by the US Food and Drug Administration (FDA). The devices used for the descending thoracic aorta (DTA) have certain size and design limitations that make their application to the AA cumbersome at times. As a result, custom-made endografts have been used to treat pathologies in the AA, although their use is feasible only in elective procedures. In addition, the AA has specific anatomic and physiologic characteristics that raise concerns about the long-term durability of the current technology. In this review, we outline the limitations, challenges and current status of endovascular technology to treat pathologies of the AA.

Endovascular therapy for patients with heritable thoracic aortic disease.

BACKGROUND: Patients with genetic or heritable aortic conditions and thoracic aortic aneurysm syndrome often develop cardiovascular abnormalities originating at the aortic root and affecting the entire thoracoabdominal aorta. Although thoracic endovascular aortic repair (TEVAR) is usually avoided in these patients, TEVAR may be worthwhile for those at high risk for surgical complications and in certain emergency circumstances. We explored indications for TEVAR in patients with suspected or confirmed genetic or heritable aortic conditions and investigated early and mid-term outcomes. METHODS: Our institutional aortic surgery database was queried for patients with suspected or confirmed Marfan syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome, Turner syndrome, neurofibromatosis, or familial aortic aneurysm and dissection who underwent TEVAR between February 1, 2002 and October 31, 2020. We extracted operative details and in-hospital, follow-up, and survival data. RESULTS: Thirty-seven patients who underwent 40 endovascular interventions met the inclusion criteria; 25 previously underwent ascending aorta or aortic root surgery, and 21 previously underwent open thoracoabdominal surgery. Postoperative complications included respiratory failure (24.3%), cardiac complications (16.2%), renal failure (13.5%), tracheostomy (8.1%), and spinal cord ischemia (paraplegia/paraparesis) (8.1%). Follow-up ranged from 1.3 to 8.5 years (median: 3.6 years), with 15 deaths overall (three early/in-hospital). Thirteen patients (35.1%) had 22 repeat interventions (open and endovascular) post-TEVAR; five had the endograft removed. CONCLUSIONS: Despite consensus that thoracic aneurysms in patients with genetic or heritable aortic conditions should be treated with conventional open surgery, the outcomes from our study suggest that TEVAR might be suitable in emergency settings or for patients in this population who are not candidates for open surgery, who are at high risk for reintervention, or who have a previously implanted Dacron graft. Nonetheless, lifelong surveillance is important for these patients after TEVAR to monitor for new dissection at distal or proximal landing zones, as repeat interventions are frequent.

Endovascular repair of acute type B thoracic aortic dissection.

Approximately one-third of patients with acute Stanford type B or DeBakey type III aortic dissection (TBAD) will develop complications, including persistent symptoms, malperfusion, enlarging aneurysms and impending rupture. In these cases, TBAD becomes a surgical emergency that requires endovascular intervention to complement the medical therapy. The immediate goal of endovascular therapy is to reestablish flow to the true lumen, stabilize the aneurysm and prevent rupture. Long-term goals are the remodeling of the descending thoracic aorta and the prevention of further surgeries in the thoracoabdominal aorta. In this report, we describe our step-by-step endovascular approach to TBAD repair.

Tissue engineering of autologous heart valves: a focused update.

The prevalence of valvular heart disease is expected to increase in the coming decades, with an associated rise in valve-related surgeries. Current options for valve prostheses remain limited, essentially confined to mechanical or biological valves. Neither selection provides an optimal balance between structural integrity and associated morbidity. Mechanical valves offer exceptional durability coupled with a considerable risk of thrombogenesis. Conversely, a biological prosthesis affords freedom from anticoagulation, but with a truncated valve lifespan. Tissue-engineered heart valves have been touted as a solution to this dilemma, by offering an immunopriviledged prosthesis combined with resistance from degeneration and the potential to grow. Although the reality of commercially available tissue-engineered heart valves remains distant, this article will highlight the cellular and clinical advancements in recent years.

Recent advancements in tissue engineering for stem cell-based cardiac therapies.

Advances in cardiac tissue engineering have recently focused on utilizing stem cells to regenerate infarcted and scarred myocardium. Due to their proliferative nature and tremendous potential for differentiation, stem cells are presently being investigated for clinical applications. Unfortunately, limiting factors such as massive cell death and poor retention have hampered clinical outcomes. Consequently, the development of an efficient delivery system for stem cells to the target site is essential. The use of innovative tissue engineering techniques has opened up new horizons within the field of cellular cardiomyoplasty. This paper will present a comprehensive overview of the recent advancements in stem cell technology destined for myocardial tissue repair. In addition, the multidisciplinary approach to tissue engineering presented here will provide the reader with insight into the clinical realization of cellular cardiomyoplasty.

Early stenosis of stentless aortic valve prosthesis: a word of caution.

Early stenosis of stentless bioprosthetic valves is rarely reported. In this report, we discuss a 75-year-old woman who presented with signs of congestive heart failure 5 months after a stentless aortic valve replacement, complicated by postoperative heparin-induced thrombocytopenia. Intraoperative findings were highly unusual, consisting of a fibrous band in the subvalvular apparatus linking the interventricular septum to the free wall of the left ventricle, resulting in significant left ventricular outflow tract obstruction. The possible causes of the fibrous band are discussed.