Transcatheter and transapical aortic valve replacement

Severe Symptomatic Aortic Stenosis in Older Adults: Pathophysiology, Clinical Manifestations, Treatment Guidelines, and Transcatheter Aortic Valve Replacement (TAVR)

The only effective treatment for symptomatic aortic stenosis in the older adult population is surgical aortic valve replacement. However, more than 30% of candidates are denied surgery due to advanced age and multiple comorbidities. Without surgical intervention, death from symptomatic aortic stenosis approximates 2% per month, with mortality rates of approximately 50% within 2 years of symptom onset. There is no effective medical treatment for severe symptomatic aortic stenosis; care has been limited to palliative remedies and end-of-life decisions. Nascent advances in miniaturization and catheter technologies provide a new and less invasive approach: transcatheter aortic valve replacement (TAVR). The current article summarizes treatment guidelines; pathophysiology; clinical manifestations, progression, and classification of severe symptomatic aortic stenosis; and introduces TAVR and discusses randomized controlled trials involving three patient populations from the United States, with relevant nursing implications.

Transcatheter aortic valve implantation options for treating severe aortic stenosis in the elderly: the nurse's role in postoperative monitoring and treatment

Severe calcific aortic stenosis (AS) is a progressive cardiac disease that predominantly affects elderly adults. The hallmark symptoms of AS include exertional dyspnea, angina, and syncope. Adults of advanced age do not usually seek treatment for symptoms until their quality of life is greatly diminished. The 2 standard treatments for severe AS are open aortic valve replacement and percutaneous valvuloplasty. As adults age, their comorbid medical conditions often make them too high of a surgical risk for traditional aortic valve replacement, and percutaneous valvuloplasty, although less invasive, often produces only temporary relief of AS symptoms. To provide severe AS patients with alternative less risky treatment options in their later years, transcatheter aortic valve implantation (TAVI) devices were developed. Through this overview of the disease progression of AS and the different TAVI devices and the insertion procedures, a better understanding of the initial postoperative nursing care associated with postoperative TAVI patient management will be achieved.

Immediate post-operative responses to transcatheter aortic valve implantation: An observational study

BACKGROUND

Conventional treatment for patients with severe symptomatic aortic stenosis is surgical aortic valve replacement (SAVR), but transcatheter aortic valve implantation (TAVI) has become a reliable alternative in high-risk patients.

AIMS

The aim of our study was to describe the post-operative patient response to TAVI on the evening of the procedure and the following day before discharge from the coronary care unit. A secondary aim was to compare responses of patients younger and older than 80 years of age.

METHODS

A prospective, comparative observational study triangulating nurse assessment and structured interviews on a cohort of 54 Danish patients: 28/26 male/female, 26/28 younger/older than 80. Mean age in the younger/older group was 73/85 years.

RESULTS

After TAVI pain was experienced by 47 (87%) patients; 29 (62%) were restricted by pain, and 24 (44%) had discomfort at the femoral insertion site. Disturbed sleep/rest were reported by 34 (63%)/29 (55%) patients; nausea/vomiting by 14 (26%)/5 (9%) patients, restricting eating/drinking in 11 (21%)/8 (15%) patients. Sinus rhythm/atrial fibrillation/paced rhythm were observed in 35 (65%)/8 (15%)/21 (39%) patients; bleeding/haematoma/oozing from femoral insertion site in 23 (45%)/10 (19%)/23 (43%) patients.

CONCLUSION

Patients older than 80 years did as well as the younger patients in our study; the main complaints were post-operative pain and disrupted sleep. Our numbers are small, but most patients experienced considerable pain, predominantly continuous and at rest. We recommend the development of an evidence-based pathway to address the immediate post-operative issues in TAVI patients. Non-pharmacological interventions to prevent pain and promote sleep need to be explored.

Transcatheter aortic valve replacement

Symptomatic severe aortic stenosis is a serious life-threatening condition that requires surgical intervention. Until recently, the only available treatment options were through an open-heart surgery technique. A transcatheter aortic valve replacement is a minimally invasive aortic valve replacement procedure that is available for symptomatic patients with severe aortic stenosis and who are considered high-risk surgical candidates. It is an effective procedure for individuals with multiple comorbidities and high risk for mortality. This article reviews aortic stenosis and associated morbidity and mortality, treatment options, complications, education, and implications.

Porcine vena cava as an alternative to bovine pericardium in bioprosthetic percutaneous heart valves

Percutaneous heart valves are revolutionizing valve replacement surgery by offering a less invasive treatment option for high-risk patient populations who have previously been denied the traditional open chest procedure. Percutaneous valves need to be crimped to accommodate a small-diameter catheter during deployment, and they must then open to the size of heart valve. Thus the material used must be strong and possess elastic recoil for this application. Most percutaneous valves utilize bovine pericardium as a material of choice. One possible method to reduce the device delivery diameter is to utilize a thin, highly elastic tissue. Here we investigated porcine vena cava as an alternative to bovine pericardium for percutaneous valve application. We compared the structural, mechanical, and in vivo properties of porcine vena cava to those of bovine pericardium. While the extracellular matrix fibers of pericardium are randomly oriented, the vena cava contains highly aligned collagen and elastin fibers that impart strength to the vessel in the circumferential direction and elasticity in the longitudinal direction. Moreover, the vena cava contains a greater proportion of elastin, whereas the pericardium matrix is mainly composed of collagen. Due to its high elastin content, the vena cava is significantly less stiff than the pericardium, even after crosslinking with glutaraldehyde. Furthermore, the vena cava's mechanical compliance is preserved after compression under forces similar to those exerted by a stent, whereas pericardium is significantly stiffened by this process. Bovine pericardium also showed surface cracks observed by scanning electron microscopy after crimping that were not seen in vena cava tissue. Additionally, the vena cava exhibited reduced calcification (46.64 ± 8.15 μg Ca/mg tissue) as compared to the pericardium (86.79 ± 10.34 μg/mg). These results suggest that the vena cava may provide enhanced leaflet flexibility, tissue resilience, and tissue integrity in percutaneous heart valves, ultimately reducing the device profile while improving the durability of these valves.

MR-based real time path planning for cardiac operations with transapical access

Minimally invasive surgeries (MIS) have been perpetually evolving due to their potential high impact on improving patient management and overall cost effectiveness. Currently, MIS are further strengthened by the incorporation of magnetic resonance imaging (MRI) for amended visualization and high precision. Motivated by the fact that real-time MRI is emerging as a feasible modality especially for guiding interventions and surgeries in the beating heart; in this paper we introduce a real-time path planning algorithm for intracardiac procedures. Our approach creates a volumetric safety zone inside a beating heart and updates it on-the-fly using real-time MRI during the deployment of a robotic device. In order to prove the concept and assess the feasibility of the introduced method, a realistic operational scenario of transapical aortic valve replacement in a beating heart is chosen as the virtual case study.