Percutaneous mitral balloon commissurotomy
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Mohammed A. Sbeih, M.D. [2]
Overview
The development of this approach was done by Inoue in 1984 and Lock in 1985 for the treatment of mitral stenosis [1][2]. For a long time, surgical commissurotomy and open valve replacement were the only methods by which mitral stenosis could be corrected [3]. PMBV can be performed in chronically symptomatic patients, patients who present emergently with cardiac arrest or pulmonary edema and in asymptomatic patients who plan on childbearing or major noncardiac surgery [4][5]. There is improvement in the mortality rates for mitral stenosis by intervention by percutaneous mitral balloon valvotomy or surgery.
The 2006 American College of Cardiology/American Heart Association (ACC/AHA) guidelines on the management of valvular heart disease recommended intervention in symptomatic patients with moderate to severe mitral stenosis [4].
Indications
In asymptomatic patients, intervention is recommended in moderate to severe MS and pulmonary hypertension (pulmonary artery systolic pressure >50 mmHg at rest or >60 mmHg with exercise).
When intervention is indicated in patients with rheumatic MS, the 2006 ACC/AHA guidelines recommend that Percutaneous mitral balloon valvotomy (PMBV) is preferred to surgery if the valve morphology is favorable and the patient does not have left atrial thrombus or moderate to severe (3+ to 4+) mitral regurgitation. Valve repair is performed if possible and preferred over valve replacement which has higher perioperative mortality and morbidity. Valve repair includes both open commissurotomy and placement of an annuloplasty ring after direct visualization of the valve [4].
The decision of whether valvuloplasty is superior to surgery depends on age (<60 favors valvuloplasty), and Cath/ECHO findings (e.g. LVEDP, degree of mobility, thickening and calcification). The average end result for the mitral valve surface area with both strategies is about 2 cm2. Moderate or greater MR (mitral regurgitation) and LA thrombus are contraindications to valvuloplasty.
Mitral stenosis is amenable to percutaneous mitral valvuloplasty if the echocardiography demonstrates :
- Thickening confined to valve tips.
- Good mobility of Anterior mitral valve leaflet.
- Little chordal involvement.
- No more than trivial mitral regurgitation.
- No left atrial thrombus.
- No commissural calcification.
To determine which patients would benefit from Percutaneous mitral balloon valvotomy (PMBV), a scoring system has been developed.2 Scoring is based on four echocardiographic criteria:
- Leaflet mobility.
- Leaflet thickening.
- Subvalvar thickening.
- Calcification.
Individuals with a score of ≥ 8 tended to have suboptimal results.3 Superb results with valvotomy are seen in individuals with a crisp opening snap, score < 8, and no calcium in the commissures.
Percutaneous mitral balloon valvotomy (PMBV) technique
The interventional cardiologist gains access to the mitral valve by making a puncture in the interatrial septum during cardiac catheterization. Inflation and rapid deflation of a single balloon or a double-balloon opens the stenotic valve. This mechanism is similar to that of surgical commissurotomy [6].
- Transvenous transeptal technique is most commonly used with the Inoue balloon system.
- Fossa ovalis lies usually at 1-7 o’clock but this orientation can be distorted in the presence of mitral stenosis where the interatrial septum becomes more flat, horizontal and lower.
- For the femoral vein approach a 70 cm Brockenbrough needle should be used or an 8 Fr Mullins sheath and advanced under fluoroscopic guidance with pressure monitoring.
- The latter is necessary to monitor for puncture into adjacent structures such as aorta.
- Further catheter manipulation may be necessary to direct the catheter into the left ventricle through the mitral valve rather than towards one of the pulmonary veins.
- The Mullins sheath is exchanged for a solid-core coiled 0.025 inch guidewire over which a 14 Fr dilator is placed.
- This is exchanged for the Inoue balloon (24-30 mm) which inflates in three stages allowing for balloon self-positioning with the last inflation resulting in commissural splitting.
A transthoracic echocardiography should be done to measure the mitral valve area and assess the severity of regurgitation as a complication of the procedure. PMBV should be stopped if adequate valve area has been achieved or if the severity of mitral regurgitation has been increased.
Outcome
- Complications are usually less than 5% of cases with low mortality.
- Failure to puncture the interatrial septum is the most common reason for aborted procedure.
- Most common complication is development of severe mitral regurgitation The indication for invasive treatment with either a mitral valve replacement or valvuloplasty is NYHA functional class III or IV symptoms.
- PMBV versus open and closed surgical commissurotomy
Some trials showed that the outcome after PMBV is better than the surgical commissurotomy approach [7]. Long term outcome studies showed that the mitral valve area was less in closed commissurotomy compared to other approaches, also the rate of restenosis was higher for closed commissurotomy approach [8].
- PMBV versus mitral valve replacement combined with tricuspid valve repair
Some trials showed that the outcome after mitral valve replacement combined with tricuspid valve repair (if the patient has tricuspid regurgitation) is better than PMBV in patients with severe mitral stenosis and severe tricuspid regurgitation [9].
References
- ↑ Carroll JD, Feldman T (1993). "Percutaneous mitral balloon valvotomy and the new demographics of mitral stenosis". JAMA. 270 (14): 1731–6. PMID 8411505.
- ↑ Inoue K, Owaki T, Nakamura T, Kitamura F, Miyamoto N (1984). "Clinical application of transvenous mitral commissurotomy by a new balloon catheter". J Thorac Cardiovasc Surg. 87 (3): 394–402. PMID 6700245.
- ↑ Lock JE, Khalilullah M, Shrivastava S, Bahl V, Keane JF (1985). "Percutaneous catheter commissurotomy in rheumatic mitral stenosis". N Engl J Med. 313 (24): 1515–8. doi:10.1056/NEJM198512123132405. PMID 4069160.
- ↑ 4.0 4.1 4.2 Bonow RO, Carabello BA, Chatterjee K, de Leon AC, Faxon DP, Freed MD; et al. (2008). "2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons". Circulation. 118 (15): e523–661. doi:10.1161/CIRCULATIONAHA.108.190748. PMID 18820172.
- ↑ Lokhandwala YY, Banker D, Vora AM, Kerkar PG, Deshpande JR, Kulkarni HL; et al. (1998). "Emergent balloon mitral valvotomy in patients presenting with cardiac arrest, cardiogenic shock or refractory pulmonary edema". J Am Coll Cardiol. 32 (1): 154–8. PMID 9669264.
- ↑ Inoue K, Feldman T (1993). "Percutaneous transvenous mitral commissurotomy using the Inoue balloon catheter". Cathet Cardiovasc Diagn. 28 (2): 119–25. PMID 8448794.
- ↑ Patel JJ, Shama D, Mitha AS, Blyth D, Hassen F, Le Roux BT; et al. (1991). "Balloon valvuloplasty versus closed commissurotomy for pliable mitral stenosis: a prospective hemodynamic study". J Am Coll Cardiol. 18 (5): 1318–22. PMID 1918709.
- ↑ Turi ZG, Reyes VP, Raju BS, Raju AR, Kumar DN, Rajagopal P; et al. (1991). "Percutaneous balloon versus surgical closed commissurotomy for mitral stenosis. A prospective, randomized trial". Circulation. 83 (4): 1179–85. PMID 2013139.
- ↑ Song H, Kang DH, Kim JH, Park KM, Song JM, Choi KJ; et al. (2007). "Percutaneous mitral valvuloplasty versus surgical treatment in mitral stenosis with severe tricuspid regurgitation". Circulation. 116 (11 Suppl): I246–50. doi:10.1161/CIRCULATIONAHA.107.678151. PMID 17846312.