Intraoperative detection of stuck leaflet of prosthetic mitral valve.

Bileaflet prosthesis valves are the most commonly used mechanical valves. Dysfunction of bileaflet prosthesis valve is rarely observed. Pannus and thrombus can obstruct prosthesis valve in postoperative period over a period of time. Here we present a rare case of intraoperatively diagnosed prosthesis valve dysfunction along with review of different mechanism causing such complication.

50 years male presented with severe shortness of breath at rest and fever since 15 days. He was already on antibiotics when he was referred to our center for further management.He was thoroughly evaluated and echocardiography showed severe mitral regurgitation with vegetation on posterior mitral leaflet bouncing in left atrium. Considering high embolic potential of the lesion, patient was urgently scheduled for open heart surgery for removal of lesion and correction of mitral regurgitation. After smooth anaesthesia induction, transesophageal echocardiography (TEE) was performed and it revealed 1.2 square cm mobile mass on the posterior mitral leaflet. (Fig. 1, clip 1) Severe mitral regurgitation was observed due to non-coaptation of mitral leaflets. (Fig. 2, clip 2) After instituting cardiopulmonary bypass, mass with mitral leaflets were resected and sent for bacterial and fungal cultures. OnX 25 mm bileaflet prosthetic mechanical mitral valve was inserted. While weaning from bypass, TEE revealed one stuck leaflet of prosthetic mitral valve in semiclosed position, where as other leaflet was moving normally. (Fig. 3, Clip 3,4) As the cardiac output was low even after optimizing loading conditions, it was decided to reinstitute cardiopulmonary bypass again. After achieving cardioplegic arrest of the heart, prosthetic valve was examined. Both leaflets could be easily opened with cotton tipped swab. We assume that subvalvular tissue might be obstructing the movement of one leaflet. So, prosthetic valve was rotated by 90 ° with the rotator. TEE showed normal movements of both leaflets of prosthetic valve. (Fig. 4, Clip 5) Hemodynamics were stable and patient was easily weaned from bypass. Postoperative course of the patient was uneventful.

Fig. 1

Midesophageal long axis transesophageal echocardiographic view showing mass on posterior mitral leaflet.

Fig. 2

Midesophageal long axis transesophageal echocardiographic view showing severe mitral regurgitation.

Fig. 3

Midesophageal 4 chamber transesophageal echocardiographic view showing one stuck leaflet in semiclosed position in systole and diastole.

Fig. 4

Midesophageal transesophageal echocardiographic view showing both leaflets in opened position.

Bileaflet prosthetic valves are most commonly used mechanical valves due to their good hemodynamic performance and low incidence of valve complications.1 Thrombosis and pannus can cause prosthetic valve dysfunction in postoperative period over a due course of time.2, 3, 4 However, Intraoperative mechanical valve dysfunction is rare event with potentially fatal complication.5, 6, 7, 8

Such complication has been reported more commonly with metallic prosthetic valves than bioprosthetic valves. Obstruction causing stuck valve can be intrinsic or extrinsic. Intrinsic obstruction is caused by inherent defects in manufacturing of the valve or defects due to wear.9 Manufacturing defect in Bjork-Shiley valve resulting in sticking of the occluder disc in the closed position has been reported.10 However with continuous improvement in prosthetic designs and materials, incidences of intrinsic failure have decreased over a period of time. Extrinsic obstruction is caused by mitral subvalvular apparatus or suboptimal orientation and mechanical obstruction by suture.1

Prosthetic mitral valve dysfunction can result in failure to wean from CPB and hemodynamic worsening. There are some reported cases of Intraoperative and early postoperative detection of stuck leaflet of prosthesis valve [Table 1]. It is essential to know the mechanism of stuck leaflet Intraoperatively so that the issue can be addressed effectively with proper management and future precautions.

Table 1

Mechanism and management of stuck prosthetic valve leaflet detected intraoperatively or early postoperatively.

Reported incidents	Mechanism of Stuck prosthetic Valve	Management
Murugesan C. et alAnn Card Anaesth 11:127–128, 2008	Tertiary chord in between disc and ring was obstructing movement of disc.	free excursion of the disc was observed after removal of chordal element
Hiroshi Kumano et alAnn Thorac Surg 1999;67:1484–5.	Subvalvular obstructionleaflet on the side of the anterolateral commissure was stuck in the closed position because of residual tissue in proximity of leaflet.	90 ° rotation of the prosthesis
Actis Dato GM. et alJ Cardiovasc Surg (Torino). 1995;36 (2):167-9.	Unravelled suture immobilising leafletThe possible explication of this rare complication is the combination between unraveled suture and the pleating held by Teflon sewing ring after restoring heart function. A flaccid heart can produce an overestimation of the annulus size and the valve ring can bring an anomalous interference with the valve mechanism.	Mechanism was revealed in autopsy.
James Jaggers et alAnn Thorac Surg 59:755–757, 1995.	Unidentified cause,structural malfunction?	Replacement of mitral prosthetic valve.
Goel S. et alJ Cardiothorac Vasc Anesth. 2011 Oct;25 (5):e44-5.	Loop of suture along the strut of bioprosthetic valve restricting mobility of one leaflet.	Problem was corrected on CPB, postoperative course was smooth.
Daniel Bolliger et al.Anesthesia analgesia 2007;104 (3):498–499.	severe regurgitation caused by immobilization of a valve leaflet in the open position.A structure responsible for obstructing leaflet motion could not be identified.	normal valve prosthesis function was achieved by a 90° rotation of the prosthesis.
Chun-Lin Chu et al.Anesthesia analgesia 2010;110 (6):1584–1586.	remnant of the native posterior leaflet was entrapped between the sewing ring and the pros- thetic leaflet.	total resec- tion of the redundant posterior mitral leaflet (mainly P3 portion) was performed, followed by reimplantation of the prosthesis.
Jorge Almeida et alInteract Cardiovasc Thorac Surg. 2007;6 (3):379–383.	discrete subvalvar tissue could be interfering with the prosthetic mechanism	occluding device was rotated to anatomic position.
Susan Pories et alAnn Thorac Surg 1988;46 (5):601–602.	papillary muscle adjacent to the sewing skirt was obstructing leaflet.	offending remnant of papillary muscle was excised, the valve was rotated within the sewing skirt and oriented away frm the area of obstruction.
R. G. Masters et alAnn Thorac Surg 1988;45:210–212.Case 1	Suture was lodged between the valve ring and disc, jamming the valve in the closed position	The disc was released. released manually, and the valve was resutured
R. G. Masters et alAnn Thorac Surg 1988;45:210–212.case 2	The tip of the posteromedial papillary muscle was wedged be- tween the disc and valve ring, locking the valve in the closed position.	The valve was opened manually, and the papillary muscle was debrided.
R. G. Masters et alAnn Thorac Surg 1988;45:210–212.Case 3	tip of the posteromedial papillary muscle was seen to lay on the valve ring, causing intermittent locking of the disc against the ring.	Debridement of the papillary mus- cle resulted in a normally functioning valve.
Miyahara K et alKyobu Geka. 1992;45 (7):635–639.	suture knots located between the valve ring and the disc prevented the occluder from seating completely and caused aortic regurgitation.	suture end was cut shorter and the prosthesis within the sewing ring was rotated so that the occluder was kept away from the suture end.
Ganesh P. Pai et alAnn Thorac Surg 1987;44:73–76.Case 1	Disc impacted by chordal debris	Excision of chordal debris
Ganesh P. Pai et alAnn Thorac Surg 1987;44:73–76.Case 2	Disc impacted by chordal debris	Excision of chordal debris
Ganesh P. Pai et alAnn Thorac Surg 1987;44:73–76.Case 3	Impending LV myocardium	Replacement of implanted prosthetic valve.
Ganesh P. Pai et alAnn Thorac Surg 1987;44:73–76.Case 4	Disc movement impeded either by calcified plaque of supraannular aorta or by interventricular septum	Valve rotated 180 ° to direct major orifice toward left coronary ostia.
Ganesh P. Pai et alAnn Thorac Surg 1987;44:73–76.Case 5	Disc impacted in closed Position by unraveled suture	Trimming of ends of unraveled suture
Donald B. Williams et alAnn Thorac Surg 1981;32 (6):58–62.Case 1Case 2Case 3	one of the sutures had migrated in- side the rim of the valve, obliterating the clearance between the disc and valve rim and causing sticking of the valve.a remnant of chordae was found to be wedged be- tween the disc and valve rim, locking the valve in the closed position.strand of chordal tissue, found compressed between the disc and the valve rim, was caus- ing the valve to stick in the closed position.	The valve was ro- tated so that the vulnerable part of the clearance was away from the offending suture, and the suture was tacked to the valve annulus directing it away from the valve orifice.The disc was easily re- leased by pressing gently on its edge, and the chordae were trimmed.After the disc was released, this chordal strand was excised and the valve appeared to func- tion normally.
Browdie DA et al.Ann Thorac Surg 1978; 26 (6):591.	Disc jamming of Lillehei-Kaster prosthesis by impaction of thin plastic tubing used for left atrial monitoring.The relatively firm, noncompressible plastic tubing commonly in use may allow the valve disc to rebound rather than jam. Softer material, in contrast, may be compressed between the disc and rim, effec- tively acting as a wedge and causing the valve to stick in the closed position.	Removal of catheter

Intraoperative Transesophageal echocardiography plays significant role in evaluating prosthetic valve function and early diagnosis and the management of the stuck valve. Acutely obstructed valve in early postoperative period can be recognized by the combination of no perceptible blood pressure even in presence of normal electrical activity of the heart, markedly raised left atrial pressure and absence of valvular prosthetic sounds.9 Donald B. Williams emphasized meticulous removal of all chordal tissue, even the most thin strand. Knots or tied sutures should be kept at an adequate distance from valve orifice.9 Leaflets motion should be checked before closing left atrium.9

Stuck prosthetic valve leaflet is uncommon but dangerous complication. Knowledge of such cases makes us prudent to prevent and manage such events.

Consent

Written informed consent was obtained from the patient’ relative for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

None