Asian Cardiovasc Thorac Ann 2006;14:e1-e3
© 2006 Asia Publishing EXchange Ltd
Late Entrapment of Ball and Cage Valve in Mitral Position
Jayesh G Akbari, MS,
Praveen K Varma, MCh,
Shrinivas V Gadhinglajkar, MD,
Kurur S Neelakandhan, MCh
Division of Cardiovascular and Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum,, India
For reprint information contact: Praveen K Varma, MCh Tel: 91 471 244 4496 Fax: 91 471 244 6433 Email: pkvarma{at}sctimst.ac.in, B-8, New faculty Quarters, Chitra staff quarters, Poonthi road, Kumarapuram, Trivandrum, Kerala-695 011, India.
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ABSTRACT
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A 32-year-old female underwent mitral valve replacement with total chordal preservation (Miki’s technique) using 26mm (1M) Starr-Edward prosthesis (SEP) in 1988. The patient was in NYHA class-I until 2001. She progressed to NYHA class-III with paroxysmal nocturnal dyspnoea. Transthoracic echocardiogram showed increased prosthetic valve gradient, and cardiac catheterization confirmed the findings. Intraoperatively, the poppet movement in the cage was found to be restricted due to the preserved subvalvular apparatus entrapping the poppet inside the prosthetic valve cage.
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INTRODUCTION
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In 1964, Lillehie, Levy and Bonnabeau recommended the preservation of the subvalvular apparatus of the mitral valve for improved short and long term left ventricular function.1 Laboratory and clinical evidence indicate that the preservation of papillary muscle-chordal attachments to the annulus is important for maintenance of left ventricular function. Moreover, this protects the atrio-ventricular groove from rupture. David, Feicks and Miki have described techniques for mitral valve replacement with total chordal preservation.2,3 These are commonly described for bi-leaflet, tilting disc and bioprosthetic valves. Late prosthetic valve dysfunction can occur as a result of overgrowth of pannus over the valve, protrusion of chordae and papillary muscles, incorrect suture technique and bacterial endocarditis.4
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CASE REPORT
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The patient was diagnosed with heart valve disease at the age of 6 years, following a febrile illness. She received medical management including digitalis and diuretic therapy, in addition to infective endocarditis prophylaxis. At 18 years of age, her symptoms worsened to New York Heart Association (NYHA) class-III. Chest X-Ray taken at that time showed a cardio-thoracic ratio of 90% with a giant left atrium. Transthoracic echocardiogram (TTE) showed severe mitral regurgitation, with anterior mitral leaflet prolapse and annular dilatation. Left ventricular dimension was 73/47 mm and ejection fraction was 63%.
She underwent mitral valve replacement (26mm SEP) with total chordal preservation, using Miki’s technique. This involves division of the anterior leaflet into anterior and posterior segments and reaffixing to respective commissures. The mid portion of the posterior leaflet was also incised to enlarge the effective orifice. She had an uneventful recovery and received regular follow-up. Postoperative TTE showed normal left ventricular and prosthetic valve function. She was asymptomatic and in sinus rhythm with normal prosthetic valve and ventricular function in subsequent annual TTE examinations. Thirteen years after surgery, she started developing dyspnoea on exertion and TTE at that time showed increased prosthetic valve gradient (22/13). In the subsequent 3 months, her symptoms worsened to NYHA class-III and the prosthetic valve gradient increased to 39/28. Left ventricular dimensions were 68/42 and ejection fraction 53%. Cardiac catheterization showed elevated pulmonary wedge pressure.
In view of the prosthetic valve dysfunction, the patient was assigned for re-replacement of the mitral valve prosthesis. Aortic and bi-caval cannulation were performed for initiation of cardiopulmonary bypass. The mitral valve was approached trans-septally. Pannus was seen overlying the sewing ring, but the primary orifice was adequate. Sutures were cut and the sewing ring was separated from the 3 to the 9 o’clock position. Pannus, subvalvular apparatus and part of the anterior mitral leaflet were seen engulfing the pillar of the cage, hampering the movement of the ball inside the cage (figure 1
). The prosthesis was completely excised and replaced with a 30mm Starr-Edward valve prosthesis. She had posterior atrioventricular groove disruption, which was repaired unsuccessfully and she expired on the table.
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Figure 1. Late prosthetic valve dysfunction due to entrapment of poppet by subvalvular mechanism. (Arrow) Anterior mitral leaflet and subvalvular apparatus with head of anterior papillary muscle.
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DISCUSSION
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Mitral valvuloplasty for correction of chronic mitral regurgitation carries a lower operative mortality and morbidity and affords superior long-term survival compared to mitral valve replacement. The procedure that most approximates mitral valvuloplasty is mitral valve replacement with preservation of chordae tendineae and papillary muscles.4 The preservation of the subvalvular apparatus helps to maintain the conical shape of the LV and prevents it from assuming a globular shape with decreased function. However, early or late prosthetic valve dysfunction due to preservation of the subvalvular apparatus remains a distinct possibility.
Mechanical malfunction of prosthetic heart valves resulting in interference with movement of the occluder mechanism can be caused by intrinsic or extrinsic factors. Intrinsic factors result from inherent defects in the manufacture of the valve or defects caused by wear and tear. Extrinsic factors include hindrance of occluder movement by thrombi, protrusion of the ventricular myocardium, accumulation of fibrin or granulation tissue on the struts of the valve, bacterial endocarditis and unresected valvular tissue. Williams et al reported their experience with four cases of malfunction due to extrinsic obstruction of a Bjork-Shiley prosthesis.5 Trites et al described one case of extrinsic obstruction of a Medtronic Hall tilting disc valve caused by rupture of the chordae tendinae and their entrapment in the disc occluder.6 Late dysfunctions of bioprosthetic valves resulting from preserved subvalvular appararatus have also been reported.7
The SEP (Model 6120) has been in clinical use for more than 30 years. The long-term durability, user friendliness and reliability of this device have been proven beyond doubt. The design of the SEP is such that the secondary orifice has a cross-sectional area of 120% of the primary orifice. Although there are some safety aspects in its basic design, stenosis of the secondary and possibly the tertiary orifice by the preserved subvalvular apparatus remains a possibility. Hence, most surgeons are reluctant to use SEP, while preserving the subvalvular apparatus. However, there are few reports available in the literature to prove this point, except a single comment by Dr. Robinson on an article published on chordal preservation by David et al. He inserted SEP with preservation of the subvalvular apparatus and reoperation was required for prosthetic mitral stenosis. The finding at re-operation was that the remaining leaflets, chordae and papillary muscles had enveloped the secondary orifice of the ball valve.
We have been employing total chordal preservation using Miki’s technique since 1988. SEP was used in the majority of the cases: to date 106 cases have been performed using SEP. Tilting disc valves, such as the Medtronic Hall® valve and Chitra heart valve (TTK-Chitra® valve, India) have also been used. Late prosthetic valve dysfunction resulting from entrapment of the ball within the cage by the subvalvular apparatus was encountered only in this reported case. Movement of the ball inside the cage was severely restricted due to pannus growth between the papillary muscles, chordae tendinae and the leaflet tissue. Histo-pathological examination showed cicatrized tissue bridging the subvalvular apparatus. Secondary and tertiary orifices were reduced in size. Hence the patient presented with features of progressive mitral stenosis. At secondary surgery, attempted excision of the subvalvular apparatus with implanted prosthetic valve caused atrio-ventricular disruption (type-III).
During excision of a previously placed prosthesis, extreme care should be taken to avoid this dreaded complication; more so with preserved subvalvular apparatus. Adequate exposure and careful dissection avoiding excessive traction while dividing the subvalvular apparatus, and the use of smaller low profile valves are recommended to avoid this complication.8 Overzealous excision, excessive traction on the subvalvular apparatus and the use of a larger sized valve could have caused the disruption in this case.
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CONCLUSION
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We report a case of late entrapment of a Starr-Edward valve due to preserved subvalvular apparatus. The entrapment was mainly due to pannus overgrowth between the subvalvular apparatus hampering the movement of occluder and also decreasing the effective secondary and tertiary orifice. In our institution only one case showed features of entrapment in more than 100 cases of valve replacements using SEP with total chordal preservation. Hence the use of SEP may not be advised in total chordal preservation, as late entrapment remains a distinct possibility.
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REFERENCES
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- Lillehei CW, Levy MJ, Bonnabeau RC Jr. Mitral valve replacement with preservation of papillary muscles and chordae tendineae. J Thorac Cardiovasc Surg 1964;57:532–43.
- Miki S, Kusuhara K, Ueda Y, Komeda M, Ohkita Y, et al. Mitral valve replacement with preservation of chordae tendineae and papillary muscles. Ann Thorac Surg 1988;45:28–34.[Abstract]
- David TE. Mitral valve replacement with preservation of chordae tendineae: rationale and technical considerations. Ann Thorac Surg 1986;41:680–2.[Abstract]
- David TE, Burns RJ, Bacchus CM, Druck MN. Mitral valve replacement for mitral regurgitation with and without preservation of chordae tendineae. J Thorac Cardiovasc Surg 1984;88:718–25.[Abstract]
- Williams DB, Pluth JR, Orszulak TA. Extrinsic obstruction of the Bjork-Shiley valve in the mitral position. Ann Thorac Surg 1981;32:58–62.[Abstract]
- Trites PN, Kiser JC, Johnson C, Tycast FJ, Gobel FC. Occlusion of Medtronic Hall mitral valve prosthesis by ruptured papillary muscle and chordae tendineae. J Thorac Cardiovasc Surg 1984;88:301–2.[Abstract]
- Prabhakar G, Kumar N, Hatle L, al-Halees Z. Accelerated failure of bioprosthesis by entrapment in chordal-sparing mitral valve replacement. J Thorac Cardiovasc Surg 1994;108:185–7.[Free Full Text]
- Karlson KJ, Ashraf MM, Berger RL. Rupture of left ventricle following mitral valve replacement. Ann Thorac Surg 1988;46:590–7.[Abstract]
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ABSTRACT
INTRODUCTION
