Introduction

Transcatheter aortic valve replacement (TAVR) is the treatment of choice for aortic stenosis in current days for patients at prohibitive and high surgical risk with extension of indications into intermediate surgical risk. TAVR may be superior to surgery in patients at low surgical risk and can potentially offer better results at initial follow?up.

Most preferred approach is the Transfemoral access, as it has a 20% relative reduction in mortality compared with surgical aortic valve replacement (SAVR). Understanding the mechanisms that underlie complications during transfemoral TAVR is essential, and familiarity with the techniques for their prevention and treatment is mandatory. An overview on the avoidable procedural complications of contemporary transfemoral TAVR practice, with a specific focus on strategies for their prevention and management is described.

 

Vascular access complications

In patients receiving first?generation valves, ≈12% of patients experienced a major vascular complication and 16% a life?threatening bleed. Major access complications include vascular injury (dissection, stenosis, perforation, rupture, fistula, pseudoaneurysm, hematoma, irreversible nerve injury, compartment syndrome, closure device failure), or a requirement for unplanned surgical/endovascular intervention leading to death, life?threatening or major bleeding, visceral ischemia, or neurological impairment.

How to avoid:

Meticulous MDCT assessment of the peripheral vessels. When transfemoral access is not feasible, MDCT is the modality of choice to assess suitability for subclavian access or to determine the location of “calcium?free windows” in the descending aortic wall if transcaval access is being considered.

How to manage:

Transradial secondary access has recently been demonstrated to be suitable for the management of peripheral vascular complications during TAVR.

Limited dissection or perforation may be successfully managed by prolonged occlusive balloon inflation.

 

Device landing zone rupture

Device landing zone rupture is a rare but feared complication of TAVR, with an overall mortality up to 48% and can be as high as 75% in cases of uncontained rupture. The most frequent anatomic site of rupture is the aortic annulus (involved in two thirds of cases), although left ventricular outflow tract (LVOT, 10%), sinus of Valsalva (16%), and sinotubular junction (6%) rupture have also been described.

How to avoid:

Meticulous procedural planning using preprocedural imaging with MDCT and 3?dimensional reconstruction is essential to minimize the risk of landing zone rupture. The choice of valve prosthesis is also critical, and a self?expandable valve is preferable in cases with a high?risk LVOT calcification pattern and shallow sinuses of Valsalva.

How to manage:

Conversion to emergency surgery is the only possible solution in case of uncontained rupture. Maintenance of hemodynamic stability is essential in the acute setting, and circulatory support should be immediately considered alongside a rapid search for the cause of hemodynamic instability using angiography and/or transthoracic/transesophageal echocardiography.

Percutaneous coil embolization to seal the point of landing zone rupture in cases of rapid deterioration.

 

Device embolization

Valve embolization is an infrequent yet important TAVR complication (Table 1) and accounts for ≈45% of emergency cardiac surgery in patients treated with TAVR with 9 times increase in mortality. Valve dislocations are either cranial toward the aorta or caudal into the LVOT/left ventricle. Aortic embolization is commonly the result of deployment in a high position and/or poor coaxial alignment of the device to the valve plane during implantation.

How to avoid:

Avoidance of stored tension in the delivery system

How to treat:

Hemodynamics

General anesthesia and femoral?femoral cardiopulmonary bypass can be considered before conventional cardiac surgery.

 

Coronary occlusion

Coronary artery obstruction by leaflet material during TAVR is a relatively infrequent complication but has potentially catastrophic clinical consequences, with an associated mortality of up to 50%. Intraprocedural coronary occlusion is more common during valve?in?valve procedures.

How to avoid:

Preprocedural cardiac MDCT is critical to identify patients at risk of coronary occlusion by measurement of the height of the coronary ostia in relation to the aortic annulus, the width and height of the sinus of Valsalva, and the width of the sinotubular junction.

How to manage:

Immediate cannulation of the affected coronary artery with a guiding catheter is required to allow balloon angioplasty. 

 

Stroke

Recent trials in low?risk patients have demonstrated a low incidence of disabling stroke. The occurrence of TAVR?related stroke demonstrates a bimodal pattern of distribution, with up to 50% of events occurring within the first 24 hours after TAVR (dependent on clinical and procedural factors) and a late phase >10 days after TAVR (dependent on clinical characteristics.

How to avoid:

Optimal anticoagulation throughout the procedure is essential to minimize thrombus formation.

CEPDs positioned across the origins of the supra?aortic vessels capture or deflect embolic debris away from the cerebral vasculature and potentially reduce the burden of ischemic strokes during TAVR.

How to manage:

Prompt access to computed tomography of the brain, computed tomography cerebral angiography, and specialist care by a dedicated stroke team are essential. Anectodal experiences suggest that mechanical thrombectomy may have a role in acute and late?presenting stroke following TAVR.

 

Periprocedural conduction abnormalities

Conduction abnormalities requiring permanent pacemaker (PPM) implantation and development of new left bundle branch block (LBBB) remain the most common TAVR complications. Perioperative conduction abnormalities result from mechanical compression of the conduction tissue as a result of pre? or postdilatation, deep implant depth, or the use of self?expanding devices and those with longer stent frames.

How to avoid:

Rapid ventricular pacing is indeed often required during balloon aortic valvuloplasty or valve deployment and use of pacing via the left ventricular guidewire is an established technique to simplify the procedure and reduce the risk of vascular complications and pericardial effusion.

 

Conclusion

Before any TAVR procedure, it is essential for the heart team to discuss bailout options, including whether conversion to open heart surgery is appropriate. Procedural planning is key to prevent potentially catastrophic complications, including landing zone rupture, device embolization, or coronary occlusion. Preprocedural imaging is essential to plan vascular access, and intravascular lithotripsy may have a role in high?risk cases.

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Keywords

Complications of transcatheter therapay

Source

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6818016/