Percutaneous Transvenous Mitral Commissurotomy — A Modified Over-the-Wire Technique for Difficult Left Ventricle Entry

Abstract: Percutaneous transvenous mitral commissurotomy (PTMC) is an acceptable and preferred alternative to surgical commissurotomy in suitable patients with severe rheumatic mitral stenosis. Various over-the-wire techniques have been described in the past for difficult left ventricle (LV) entry during PTMC. Here, we report two cases of successful PTMC with difficult LV entry with a new modified over-the-wire technique. After several failed attempts using classical steps of Inoue PTMC technique, an AR-1 diagnostic catheter was introduced in the left atrium. The AR-1 has a favorable shape when faced end-on to the critically stenosed mitral orifice, hence facilitating LV entry by 0.035˝ hydrophilic glidewire. The hydrophilic wire was then exchanged with a 0.035˝ Amplatz super-stiff guidewire, which was coiled in vitro to make small loops of its floppy portion. This extra-stiff wire provided enough support to track the Inoue PTMC catheter to the LV cavity and small loops didn’t caused any arrhythmia during the procedure. Thus, this technique may help in reducing procedural failure for “difficult LV entry” situations in critically stenosed mitral valves.

J INVASIVE CARDIOL 2013;25(9):471-473

Key words: mitral stenosis, right Amplatz, extra-stiff wire, percutaneous transvenous mitral commisurotomy, difficult LV entry

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Percutaneous transvenous mitral commissurotomy (PTMC) is an accepted and preferred alternative to surgical commissurotomy in suitable patients with severe rheumatic mitral stenosis. Two key steps in performing PTMC are atrial septal puncture and crossing the mitral valve. After appropriate septal puncture, left ventricle (LV) entry by Inoue technique involving a free-floating entry of the Inoue balloon catheter is successful in most cases. However, even an experienced operator sometimes faces difficulty in crossing the mitral valve, which may be either due to critical mitral stenosis (mitral valve area <0.6 cm²) and severe subvalvular disease or abnormal atrial septal puncture site. Several modifications of classical Inoue technique to overcome this problem have been described in the literature.^1,2 Here, we describe two cases of “difficult LV entry” that were successfully completed using a new modified over-the-wire technique. 

Case 1

A 26-year-old female was admitted to our hospital with a history of dyspnea on exertion that was insidious in onset, gradually progressive (New York Heart Association [NYHA] class II) for the last 1 year. On clinical cardiac evaluation, the patient was diagnosed with severe rheumatic mitral stenosis. Two-dimensional cross-sectional echocardiographic and Doppler examination revealed thickened mitral valve with significant subvalvular disease. The cross-sectional area by planimetry was 0.7 cm² and the mean gradient across the mitral valve was 18 mm Hg. The left atrium (LA) in parasternal long axis view was 4.9 cm. The estimated right ventricular systolic pressure was 64 mm Hg. Wilkin’s mitral valve score was 8/16. 

The patient gave informed consent and was taken for PTMC. After standard septal puncture, several attempts to cross the Inoue balloon into the LV failed. Various attempts were made with reverse-loop and double-loop techniques, but failed to cross the mitral valve. Then, a 4 Fr AR-1 diagnostic coronary catheter was negotiated over the 260-cm long, floppy-tipped, 0.025˝ stainless-steel guidewire into the left atrium (Figure 1). This catheter shape was favorable for crossing the critically stenosed mitral valve, which was crossed with a 0.035˝, hydrophilic, 260-cm long glidewire (Figure 2). The hydrophilic wire was then exchanged with a 0.035˝ Amplatz supe-stiff guidewire, which was coiled in vitro to make extra loops of its floppy portion (Figure 3). The super-stiff wire was kept in the LV cavity, making sure the loops were not entangling the chordae or papillary muscles (confirmed on transthoracic echocardiography) and avoiding prolonged runs of ventricular tachycardia. The Inoue PTMC catheter was slenderized over this super-stiff wire without its metal stylet and gradually negotiated to park across the stenotic mitral valve orifice (Figure 4). Successful dilatation of the mitral valve was ensured with reduction of the mean left atrial pressure and the mean diastolic gradient with insignificant mitral regurgitation. 

Case 2

A 31-year-old female was admitted with clinical diagnosis of severe rheumatic mitral stenosis with atrial fibrillation and NYHA functional class III. Two-dimensional cross-sectional echocardiographic and Doppler examination revealed thickened and calcified mitral valve with significant subvalvular involvement. The cross-sectional area by planimetry was 0.5 cm² and mean gradient across the mitral valve was 22 mm Hg. Wilkin’s mitral valve score was 9/16. The LA in parasternal long axis view was 6.0 cm. Estimated right ventricular systolic pressure was 78 mm Hg. Transesophageal echocardiography did not reveal any clot in the LA. The patient was stabilized medically and was planned for PTMC after informed consent. As in the previous case, after atrial septal puncture we had difficulty in negotiating the Inoue balloon across the stenotic mitral valve. In this case, before attempting other alternative techniques, we directly used an AR-1 diagnostic catheter to cross the stenotic mitral valve and a 0.035˝ Amplatz super-stiff guidewire to track the Inoue catheter to the LV, and thus completed the procedure successfully. There was no clinically and hemodynamically significant mitral regurgitation and the patient was discharged without any complications.

Discussion

The technique followed worldwide currently for PTMC is transseptal entry into the LA followed by entry of a free-floating Inoue PTMC catheter into the LV. Difficulties are often encountered to cross the mitral valve in situations such as a very medial or lower septal puncture, giant as well as small LA cavity, and significant subvalvular thickening with an eccentric mitral orifice. Various modifications of the standard technique have been described in the literature for difficult LV entry; for example, the “reverse-loop” technique, the “double-loop” technique, the “vertical approach” using left ventricular pressure as a guide for LV entry,^1-4  and various over-the-wire techniques and transjugular approach.⁵ An over-the-wire technique using bifoil or trefoil catheters with a long sheath support has been described.⁶ Another over-the-wire Multitrack system had fair results and was shown to be cost effective, but doesn’t address the problem of difficult LV entry.⁷ The over-the-wire double-balloon technique (DBT) of balloon mitral valvuloplasty (PTMC) has been decreasingly used in recent years because of its relative complexity and potential for left ventricular perforation.¹² A relatively simple over-the-wire single-balloon technique (SBT) using either the femoral or jugular approach for transseptal mitral valve dilatation showed fair results.¹³ Use of such over-the-wire balloons has had the advantage of lower cost compared to the Inoue balloon, but disadvantages of longer fluoroscopy time, increased incidence of ventricular tachyarrhythmia, and (rarely) ventricular perforation.                                                            

 The technique described by Meier uses a 0.020˝ J-tip back-up wire to cross the mitral valve and JR diagnostic catheter introduced over it. Through the JR catheter, a 0.025˝ pigtail stainless-steel wire is introduced in the LV and then over this wire, the Inoue PTMC catheter is introduced.¹⁰ However, in our experience, the 0.025˝ stainless-steel wire provides inadequate support for Inoue balloon catheter, for which we used a 0.035˝ Amplatz super-stiff guidewire. In addition, the AR catheter is better than the JR catheter for difficult LV entry since it faces end-on to the mitral orifice (Figure 6). Another technique by Mehan and Meier advocated the use of a balloon flotation catheter (Swan-Ganz) to cross the mitral valve and placing it in the ascending aorta, through which a 0.021˝ long back-up guidewire passed to the descending aorta, and then the Inoue balloon was introduced over this wire.¹¹ This is a more challenging and cumbersome technique, and involves crossing two valves. In another over-the-wire Inoue balloon technique, the coiled, stainless-steel, 0.025˝, 260-cm long guidewire that was used has a large loop diameter, which increases chances of arrhythmias (Figure 5).^12,13 In our case, we have made smaller loops of 0.035˝ Amplatz extra-stiff glidewire with artery forceps in vitro, and were thus well accommodated in the LV (Figure 6). Also, the support provided by a 0.025˝ stainless-steel wire is less when compared to a 0.035˝ Amplatz extra-stiff glidewire. 

A catheter with a shape that facilitates LV entry through the stenosed mitral valve and an extra-support wire with a floppy tip positioned well in the LV cavity for tracking the Inoue catheter are the maneuvers likely to troubleshoot the problem of “difficult LV entry.” An AR-1 diagnostic coronary catheter has an inherent shape that faces the mitral valve orifice end-on and hence higher chances of crossing even a critically stenosed and/or an eccentric mitral valve orifice. In vitro modifications of the extra-stiff 0.035˝ wire increase the chance of the super-stiff wire remaining stable in the LV cavity without producing sustained runs of ventricular tachyarrhythmia and not encompassing any chordae or papillary muscles. Over-the-wire use of Inoue PTMC catheter using a 0.035˝ extra-stiff guidewire combines the versatility of Inoue catheter and extra support of a stiff guidewire.

Conclusion

These two cases highlighted a modification of the over-the-wire technique to cross the mitral valve in difficult cases of PTMC. This modified technique to cross the stenotic and eccentric mitral valve with an AR-1 diagnostic catheter should be reproducible and the preshaped Amplatz 0.035˝ super-stiff guidewire provides enough support to negotiate the Inoue PTMC catheter across a stenotic mitral valve. Hence, this technique can be reserved for difficult LV entry during PTMC. 

Acknowledgment. The authors are highly thankful to Professor Tejas Patel, DM, FACC, FSCAI, FESC, for his expert opinion during preparation of the manuscript.

References

1. Ramamurthy S, Bahl VK, Manchanda SC. Successful Inoue balloon valvotomy in a difficult case of mitral stenosis using multiple modifications of technique: alternative method for loop formation of the Inoue balloon catheter. J Invasive Cardiol. 2001;13(11):755-757.
2. Trehan V, Mehta V, Mukhopadhyay S, et al. Difficult percutaneous transvenous mitral commissurotomy: a new technique for left atrium to left ventricular entry. Indian Heart J. 2004;56(2):158-162.
3. Hung JS, Lau KW. Vertical approach — a modified method in balloon crossing of mitral valve in Inoue balloon mitral valvuloplasty. J Invasive Cardiol. 1998;10(9):548-550.
4. Safi AM, Kwan T, Clark LT. Successful percutaneous balloon mitral valvuloplasty using left ventricular pressure as a guide to cross the mitral valve — a case report. Angiology. 2000;51(1):83-86.
5. Joseph G, George OK, Mandalay A, Sathe S. Transjugular approach to balloon mitral valvuloplasty helps overcome impediments caused by anatomical alterations. Catheter Cardiovasc Interv. 2002;57(3):353-362.
6. Meier B, Friedli B, Von Segesser L. Valvuloplasty with trefoil and bifoil balloons and the long sheath technique. Herz. 1988;13(1):1-13.
7. Bonhoeffer P, Esteves C, Casal U, et al. Percutaneous mitral valve dilatation with the Multi-Track system. Catheter Cardiovasc Interv. 1999;48(2):178-183.
8. Bugliani-Pastalka L, Bugliani G, Suter T, et al. Long-term results after successful mitral valvuloplasty: comparison of Inoue and double balloon technique. Schweiz Med Wochenschr. 2000;130(35):1216-1224.
9. Joseph G, Chandy S, George P, et al. Evaluation of a simplified transseptal mitral valvuloplasty technique using over-the-wire single balloons and complementary femoral and jugular venous approaches in 1,407 consecutive patients. J Invasive Cardiol. 2005;17(3):132-138.
10. Meier B. Modified Inoue technique for difficult mitral balloon commissurotomy. Cathet Cardiovasc Diagn. 1992;26(4):316-318.
11. Mehan VK, Meier B. Impossibility to cross a stenotic mitral valve with the Inoue balloon: success with a modified technique. Indian Heart J. 1994;46(1):51-52.
12. Manjunath CN, Srinivasa KH, Patil CB, et al. Balloon mitral valvuloplasty: our experience with a modified technique of crossing the mitral valve in difficult cases. Catheter Cardiovasc Interv. 1999;46(1):117-118.
13. Dani SI, Patel TM, Chag MC, et al. Difficult mitral valvuloplasty: an “over the wire” modification of Inoue technique. J Invasive Cardiol. 1995;7(5):148-151.