Aortic stenosis valvuloplasty


 * Joanna J. Wykrzykowska, M.D.; Mohammed A. Sbeih, M.D. [mailto:msbeih@perfuse.org]

Overview
Although surgical aortic valve replacement is the mainstay of treatment of aortic stenosis as it improves both symptoms and life expectancy, some patients may not be surgical candidates due to comorbidities, and minimally invasive treatment such as percutaneous aortic balloon valvotomy (PABV) maybe an alternative to surgery as a palliative strategy. PABV is a procedure in which 1 or more balloons are placed across a stenotic valve and inflated to decrease the severity of aortic stenosis. This is to be distinguished from transcatheter aortic valve implantation (TAVI) which is a different method that involves replacement of the valve percutaneously.

Indications

 * Surgical aortic valve replacement is the treatment of choice for aortic stenosis but many patients are not good candidates due to advanced age and multiple co-morbidities.
 * Percutaneous aortic valve replacement is in its infancy and thus aortic valvuloplasty can offer palliation of symptoms and potentially prolong survival for these high risk patients in class III-IV heart failure
 * It can be performed emergently in patients with end-stage heart failure due to aortic stenosis: patients in cardiogenic shock, as a bridge to aortic valve replacement, patients with critical aortic stenosis needing emergent non-cardiac surgery, poor surgical candidates and nonagenerians, patients with congenital or rheumatic aortic stenosis
 * Results usually last 6 months up to 2 years (with repeat procedures possible if aortic regurgitation is not severe)
 * Valvuloplasty tends to alleviate heart failure symptoms and improve hemodynamics but rarely does it alleviate angina


 * ACC/AHA guidelines concluded that percutaneous aortic balloon valvotomy (PABV) is not a substitute for aortic valve replacement in adults. In adults with severe calcific AS who are not good candidates for this procedure as there is high restenosis rate (more than 10% of cases) and high risk of complications. Clinical deterioration occur within 6 to 12 months in most patients, and that is why balloon valvotomy is not a substitute for aortic valve replacement surgery. The procedure can be used in children and young adults with congenital, noncalcific AS.

==ACC/AHA Guidelines- Indications for Percutaneous Aortic Balloon Valvotomy (DO NOT EDIT) == {{cquote|

Class IIb
1. Aortic balloon valvotomy might be reasonable as a bridge to surgery in hemodynamically unstable adult patients with AS who are at high risk for AVR. (Level of Evidence: C)

2. Aortic balloon valvotomy might be reasonable for palliation in adult patients with AS in whom AVR cannot be performed because of serious comorbid conditions. (Level of Evidence: C)

Class III
1. Aortic balloon valvotomy is not recommended as an alternative to AVR in adult patients with AS; certain younger adults without valve calcification may be an exception. (Level of Evidence: B)}}

Percutaneous Aortic Balloon Valvotomy (PABV) Technique

 * After preparing the patient, a guide wire is inserted through the femoral artery into the aorta (retrograde technique). 8 French femoral sheath can usually accommodate a 20 mm balloon and minimizes vascular complications. Alternatively two 6 Fr sheath from bilateral femoral approach and two smaller balloons can be used. the latter may be necessary in female elderly patients with concomitant peripheral vascular disease.
 * 0.035” straight wire is commonly used to cross the valve and advance via pig-tail or Amplatz catheter; right heart catheterization is done and transaortic gradient is typically measured pre-procedure. The 0.035” wire is then exchanged for a stiffer 0.038”Amplatz exchange length wire with the tip shaped into a pig-tail shape so as not to injure the left ventricle.


 * A long sheath is introduced over the guide wire, through the sheath a Mansfield balloon is introduced and 20-23 mmX 6 cm balloon is advance over the wire and positioned to straddle the aortic valve.


 * The balloon is manually inflated with a 60 cc syringe containing diluted contrast (slowly). Meticulous control of balloon position must be maintained at all times by backward traction on the balloon to prevent jumping forward and injuring/perforating the left ventricular apex.


 * If there is difficulty in maintaining the balloon across the aortic valve during inflation, temporary ventricular pacing at high rate can reduce the cardiac output and give stability to the balloon.


 * Balloon is deflated and the trans valvar gradient reassessed for success of the procedure. Repeated dilatations can be given if necessary.


 * The balloon should be de-aired and filled with dilute contrast to avoid the chance of air embolism in case of balloon rupture during dilatation.

Outcome

 * Immediately after the procedure a moderate reduction in the transvalvular pressure gradient is usually observed. The aortic valve area after the procedure rarely exceeds 1.0 cm2 but an early symptomatic improvement is usually observed.


 * Patient survival after repeat PABV is higher than that of untreated patients.

Complications

 * Vascular complications are most common thus suture (Perclose) or Angioseal closure after the procedure in this tenuous patient population is preferable.
 * It follows that attention to meticulous access technique is mandatory.
 * Antegrade approach ie venous access with transseptal approach can be done in select patients, however, hemodynamic effects of mitral valve incompetence as a stiff wire is placed across the mitral valve are often poorly tolerated; mitral valve injury has been reported in this approach.
 * There is a small but significant risk of development of aortic regurgitation as a result of the procedure which can lead to pulmonary edema.
 * The balloon may rupture while dilation of a calcified valve is performed.