Echocardiographic diagnosis of left ventricular outflow tract obstruction after mitral valve replacement with subvalvular preservation.

We describe two cases of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus. The first patient deteriorated immediately after insertion of a high-profile bioprosthesis. In the second patient, chronic left ventricular outflow tract obstruction developed after the insertion of a low-profile mechanical prosthesis. The clinical course of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus may differ greatly. Evaluation of the left ventricular outflow tract by perioperative transesophageal echocardiography or epicardial echocardiography is essential in the prevention and treatment of this complication.     

Rescue surgical embolectomy for fatal pulmonary embolism in patient with intracranial hemorrhage

Left ventricular outflow obstruction may result from preserving the anterior leaflet after mitral valve replacement. A 79-year-old woman, who had a mitral valve replacement with the native mitral leaflets left intact 16 years before, was admitted to our hospital with severe dyspnea due to heart failure. Echocardiography showed systolic anterior motion of preserved anterior mitral leaflet, and continuous wave Doppler detected severe left ventricular outflow tract jets during systole without mitral chordal rupture. Surgical incising of the anterior mitral leaflet through the aortic root relieved the obstruction without removing the prosthetic mitral valve.     

Expanding the use of total mitral valve preservation in combination with implantation of the CarboMedics heart valve prosthesis.

BACKGROUND: Preservation of the mitral valve and subvalvular apparatus was introduced into the clinic in the early sixties, but for two decades the standard technique for mitral valve replacement included excision of both leaflets and their attached chordae tendineae. Lately, increased emphasis has again been placed on retention of the mitral subvalvular apparatus during valve replacement because of its role on left ventricular function. METHODS: We have preserved the valvular and subvalvular mitral apparatus, when possible, in connection with mitral valve replacement during the last seven years and the present investigation (partly prospective and partly retrospective) was done with the aim of making up the results of our mitral preservation technique. In the period between January 1990 and December 1995, 30% of the patients who underwent mitral valve replacement had complete retention of all mitral tissue. In 1996, the percentage had increased to 50, and during the first seven months of 1997, 70% of the patients had complete retention of all mitral tissue. Since January 1997, we have exclusively used the CarboMedics mitral heart valve prosthesis. A total of 56 patients were identified to have had a CarboMedics heart valve prosthesis implanted. There were 33 men and 23 women with a mean age of 63 years, range 23-77 years. Coronary bypass was a concomitant procedure in 22 patients. In seven patients, both the mitral and aortic valves were replaced. A severely altered valve with thickened and or calcified leaflets, stenotic leaflets, or shortened, retracted and thickened chordae tendineae were not a contraindication for the procedure. Calcified plaques were removed. Adhesion between anterior and posterior leaflets was treated with sharp dissection. Valve and subvalvular tissue were preserved. The leaflets were reefed within the valve-sutures and compressed between the sewing ring and the native annulus when implanting the valve prosthesis. Chordal tension on the ventricle was thereby maintained and the chordae pulled away from the valve effluent. Echocardiography with measurement of ejection-fraction was performed preoperatively during the postoperative course in case of cardiac problems and on a routine basis 1 month after surgery and at various intervals when the patient was seen in the outpatient clinic. Left ventricular outflow tract gradients were measured during the postoperative course in case of cardiac problems and routinely 1 month postsurgically. RESULTS: Five patients died in the postoperative period and one patient had transient neurological symptoms. In none of the patients was death or transient neurological symptoms a consequence of the retention of mitral leaflets with subvalvular apparatus. The remaining 51 patients were all alive at follow-up. Postoperative echocardiography demonstrated a preserved left ventricular function and a left ventricular outflow tract without obstruction. CONCLUSIONS: We find that the described technique in combination with implantation of a CarboMedics heart valve prosthesis is very useful even in patients with a severely altered valve, when preserving the mitral leaflets with subvalvular apparatus during valve replacement. The technique is without procedure related complications and preserves left ventricular function without obstructing the left ventricular outflow tract.     

Sustained improvement after combined anterior mitral valve leaflet retention plasty and septal myectomy in preventing systolic anterior motion in hypertrophic obstructive cardiomyopathy in children

Objective: Anatomic alterations of the mitral valve such as increased mitral leaflet area, length and laxity, and anterior displacement of the papillary muscles in hypertrophic obstructive cardiomyopathy predispose patients to residual systolic anterior motion and persistence of outflow obstruction and mitral regurgitation after septal myectomy. We investigate the long-term results of combined anterior mitral leaflet retention plasty and septal myectomy in children with hypertrophic obstructive cardiomyopathy. Methods and results: Anterior mitral leaflet retention plasty and subaortic septal myectomy were performed in 12 children (mean age 10.8 ± 1.7 years) with hypertrophic obstructive cardiomyopathy. Mean preoperative left ventricular outflow tract pressure gradient was 49 ± 11 mmHg. After careful assessment of the mobility of the anterior leaflet and subvalvular apparatus, segments of the anterior leaflet nearest the trigones were sutured to the corresponding posterior annulus with polypropylene reinforced with untreated autologous pericardial pledgets. Intraoperative valve orifice measurement based on age-related valve diameter ensures that no mitral stenosis is produced. Mean intraoperative pre- and post-septal myectomy pressure gradient was 60 ± 25 mmHg and 5 ± 6 mmHg, respectively. Post-myectomy mitral insufficiency was reduced to a regurgitant fraction of 0–10%. Mean follow-up is 11.85 ± 1.22 years. Mean left ventricular outflow tract pressure gradient was 6.2 ± 3.95 mmHg. No mortality, no repeat myectomy or repeat mitral valve repair or replacement, no mitral stenosis and no systolic anterior motion occurred. Conclusions: Long-term follow-up shows sustained absence of systolic anterior motion, attenuation of mitral regurgitation, sustained improvement in functional status, and reduction of outflow tract obstruction.     

Obstruction of left ventricular outflow tract after mechanical mitral valve replacement

We successfully operated on a patient with a rare complication of left ventricular outflow tract obstruction after mitral valve replacement. In a 57-year-old woman with previous mitral valve replacement, transthoracic echocardiography showed left ventricular outflow tract obstruction as a result of anterior displacement of the mitral prosthesis and local thickening of the interventricular septum. Cardiac surgery verified this rare lesion. During the operation, the anterior half of the prosthesis ring was cut away from hyperplastic tissue and sutured to the natural mitral annulus. Subaortic hyperplastic tissue was excised to enlarge the left ventricular outflow tract. The patient had an uneventful postoperative recovery, and left ventricular outflow tract obstruction disappeared on postoperative transthoracic echocardiography.     

Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement

Dynamic left ventricular outflow tract obstruction developed in a patient in whom the anterior leaflet was retained at mitral valve replacement. It was caused by systolic anterior movement of the native anterior leaflet. Reduced outflow tract diameter, resulting from both posterior displacement of the septum and anterior displacement of the native anterior leaflet by porcine stents, was likely instrumental in promoting dynamic obstruction.     

Use of the Alfieri edge-to-edge technique to eliminate left ventricular outflow tract obstruction caused by mitral systolic anterior motion

A 68-year-old woman with concentric left ventricular hypertrophy, prosthetic valve endocarditis with aortic root abscess, and sepsis had aortic root replacement with an aortic allograft. On weaning from cardiopulmonary bypass, she had hemodynamic instability caused by systolic anterior motion of the mitral valve, which resulted in a left ventricular outflow tract obstruction; the peak pressure gradient across the left ventricular outflow tract was 130 mm Hg, and there was moderately severe (3+) mitral regurgitation. After reinstitution of cardiopulmonary bypass, a central Alfieri edge-to-edge stitch was placed between the anterior and posterior leaflets of the mitral valve. This reduced the gradient across the left ventricular outflow tract to 10 mm Hg and eliminated the mitral regurgitation, which enabled successful separation from cardiopulmonary bypass.     

Potential mechanism of left ventricular outflow tract obstruction after mitral ring annuloplasty

OBJECTIVES: The purpose of this study was to explore whether geometric changes that predispose to left ventricular outflow tract obstruction after mitral ring annuloplasty are coupled to subvalvular apparatus disturbances. METHODS: Radiopaque markers were implanted in sheep: 9 in the ventricle, 1 in the high interventricular septum, 1 on each papillary muscle tip, 8 around the mitral anulus, 4 on the anterior mitral leaflet, and 2 on the posterior leaflet. One group served as control (n = 5); the others were randomized to undergo annuloplasty with the Duran ring (n = 6; Medtronic, Inc, Minneapolis, Minn) or Carpentier-Edwards Physio ring (n = 6; Baxter Healthcare Corp, Irvine, Calif). After a 7- to 10-day recovery period, 3-dimensional marker coordinates were measured with biplane videofluoroscopy. RESULTS: At the beginning of ejection, (1) the anterior leaflet was displaced toward the left ventricular outflow tract; (2) the normal atrially flexed anterior anulus was flattened into the left ventricular outflow tract; (3) the posterior anulus was displaced toward the left ventricular outflow tract; (4) the anterior papillary muscle was displaced septally; and (5) the posterior papillary muscle was dislocated inwardly toward the anterior papillary muscle in the Physio ring group compared with the control group. During ejection, all these structures moved septally, encroaching further on the left ventricular outflow tract. In the Duran ring group, only the posterior anulus was displaced toward the left ventricular outflow tract; the anterior leaflet was not displaced toward the left ventricular outflow tract, and it did not move septally during ejection. CONCLUSIONS: The semirigid Physio ring was associated with perturbations in annular dynamics that caused changes in papillary muscle geometry. We propose an integrated valvular-subvalvular mechanism to explain displacement of the anterior leaflet into the left ventricular outflow tract after mitral ring annuloplasty.     

Systolic anterior motion of the mitral valve despite the sliding leaflet technique for repair of the mitral valve

We report a systolic anterior motion of the anterior mitral leaflet despite employing the sliding leaflet technique for repair of mitral valve regurgitation. A 65-year-old man with chronic, symptomatic mitral regurgitation due to ruptured chordae tendineae underwent mitral valve repair by quadrangular resection of the posterior leaflet and sliding leaflet technique with ring annuloplasty. After weaning from cardiopulmonary bypass, left ventricular outflow obstruction developed and transesophageal echocardiography demonstrated systolic anterior motion of the mitral valve and severe mitral regurgitation. Non-operative treatment resolved the outflow tract obstruction, systolic anterior motion and mitral regurgitation. We conclude that post-repair systolic anterior motion can still occur after the sliding plasty procedure and that medical treatment can successfully resolve systolic anterior motion and outflow tract obstruction in most patients.     

Transaortic edge-to-edge mitral valve repair and left ventricular myectomy

Systolic anterior motion of mitral anterior leaflet is a serious clinical condition and it is hard to control medically. Alfieri edge-to-edge repair has been thought one of the useful techniques to improve abnormal anterior systolic motion with hypertrophic obstructive cardiomyopathy. Here, we present a 71-year-old lady who had the left ventricular outflow tract obstruction, severe mitral valve regurgitation with systolic anterior motion. The patient had a history of aortic valve replacement 5 years ago. She was successfully treated with transaortic edge-to-edge mitral valve plasty and myectomy of the left ventricle. Postoperative course was uneventful.     

Left ventricular outflow tract obstruction with mitral mechanical prosthesis.

Left ventricular outflow tract obstruction after mitral valve replacement may occur when the native mitral apparatus is preserved intact. Although it has usually been reported using bioprostheses, we present one case using a low-profile mechanical prosthesis. The reduction of left ventricular dimensions and valvular redundancy contributed to this complication. We obtained definitive relief of left ventricular outflow tract obstruction by transaortic exposure and partial resection of the obstructing tissue with the help of video-assisted cardioscopy.     

Simplified correction of outflow obstruction after mitral valve replacement.

Left ventricular outflow tract obstruction after mitral valve replacement may occur when a retained native anterior leaflet prolapses between prosthetic struts. Existing reports of left ventricular outflow tract obstruction by this mechanism lack emphasis on its surgical treatment. We obtained definitive relief of left ventricular outflow tract obstruction by transaortic exposure, division, and partial excision of the obstructing leaflet. This approach minimizes the complexity and potential morbidity of the correction.     

Sudden Development of Intraoperative Left Ventricular Outflow Obstruction: Differential and Mechanism. An Intraoperative Two-Dimensional Echocardiographic Study

Systolic anterior motion (SAM) of the mitral valve, once considered to be pathognomonic of hypertrophic cardiomyopathy, has been reported in the absence of asymmetric septal hypertrophy. Of the 1,000 open heart operations performed with intraoperative two-dimensional epicardial echocardiography monitoring, four patients developed intraoperative dynamic left ventricular outflow obstruction associated with systolic anterior motion of the mitral valve that was not present preoperatively: three cases of mitral valve annuloplasty with Carpentier ring insertion and one of coronary artery bypass grafting. Though no patient had asymmetric septal hypertrophy or echocardiographic evidence of outflow obstruction by either preoperative cardiac catheterization or echocardiography, intraoperative two-dimensional epicardial echocardiography revealed SAM, and hyperdynamic left ventricles with three of these patients having documented left ventricular outflow tract gradients causing hemodynamic compromise. (Case 4 was hemodynamically stable following mitral valve repair, but had SAM and significant residual mitral regurgitation [MR] requiring reinstitution of cardiopulmonary bypass and re-repair). Measurement of mitral annular dimension demonstrated a normal decrease in size from diastole to systole in control operative subjects but not in the patients who developed outflow obstruction. The pathophysiology, treatment, and role of intraoperative echocardiography of dynamic left ventricular outflow tract obstruction are discussed.     

Obstruction dynamique intraventriculaire gauche après chirurgie réparatrice valvulaire mitrale

A 71 -years-old patient, undergoing mitral valve repair for degenerative valvulopathy and correction of pectus excavatus experienced a cardiogenic shock after weaning from cardiopulmonary bypass. The shock occurred after calcium chloride administration and was unresponsive to inotropic drugs. Transoesophageal echocardiography showed left ventricular outflow tract obstruction due to systolic anterior motion (SAM) of the mitral valve. Discontinuation of inotropic drugs and volume expansion restored the haemodynamic status. By its haemodynamic effects calcium chloride can cause left ventricular outflow tract obstruction, recognized by transoesophageal echocardiography.     

Surgical management of left ventricular outflow tract obstruction in a specialized hypertrophic obstructive cardiomyopathy center

ObjectivesThis study evaluates operative approach and contemporary surgical outcomes in the management of left ventricular outflow tract obstruction by a single surgeon at a high-volume, specialized hypertrophic cardiomyopathy center.MethodsThis is a retrospective review of 1559 consecutive operations for left ventricular outflow tract obstruction from 2005 to 2015. Demographic profiles, echocardiogram-derived ventricular morphology and hemodynamics, operative data, and in-hospital outcomes were analyzed.ResultsOf the 1559 operations, 586 were isolated septal myectomies, 522 were myectomies with mitral valve or subvalvular apparatus intervention, 422 were myectomies with another concomitant procedure, and 29 were isolated mitral valve interventions without myectomy. Common mitral valve interventions included anterior leaflet shortening (16%), chordae tendineae resection (9.8%), papillary muscle resection (7.2%), and papillary muscle reorientation (7.5%). Ninety-two patients underwent mitral valve replacement, 42 for left ventricular outflow tract obstruction and 50 for intrinsic mitral valve pathology. Patients undergoing mitral interventions had thinner septums (18 ± 0.4 mm vs 22 ± 0.5 mm, P < .001) and less myocardium removed (6.2 ± 3.5 g vs 8.8 ± 3.8 g, P < .001) than patients without a mitral intervention. Prevalence of in-hospital permanent pacemaker insertion was 4.2% (n = 1334) for complete heart block and 1.1% (n = 464) for isolated septal myectomy with normal preoperative conduction. Overall, there were 2 postoperative ventricular septal defects (0.13%) and none for isolated myectomies. Operative mortality was 0.38%.ConclusionsSeptal myectomy can be performed safely with excellent outcomes when the procedure is performed by a highly experienced surgeon in a high-volume, specialized center. A mitral valve intervention is a useful adjunct in patients with moderate hypertrophy.     

Accessory mitral valve associated with aortic regurgitation in an elderly patient: report of a case

We encountered a 75-year-old man who complained of exertional dyspnea. An echocardiographic examination showed aortic regurgitation and a tumor in the left ventricular outflow tract. Under complete extracorporeal circulation, we surgically made an incision of the ascending aorta with a slight thickening of the aortic valve and an enlarged annulus. After excising the aortic valve, an examination of the subvalvular region revealed mitral valve-like tissue extending from the annular region of the right coronary cusp to the ventricular septum, while the chordae tendinae was attached to the septum. This issue was excised, and the aortic valve was replaced with a 27-mm SJM valve. The postoperative course was uneventful, and the patient was discharged in good condition on postoperative day 30. An accessory mitral valve is extremely rare. Since this indication for surgical treatment is associated with congenital heart disease or a left ventricular outflow tract obstruction, most patients are young. Our patient had no associated cardiac anomalies and no pressure gradient attributable to a left ventricular outflow tract obstruction. This accessory mitral valve was discovered during aortic valve replacement surgery. To our knowledge, our patient is the oldest reported with an accessory mitral valve to have undergone a surgical resection.     

Experience with twenty-eight cases of systolic anterior motion after mitral valve reconstruction by the Carpentier technique.

Systolic anterior motion of the mitral valve with left ventricular outflow tract obstruction after Carpentier-type mitral reconstruction with ring annuloplasty has led some surgeons to abandon an otherwise successful repair or to avoid use of a rigid ring. To assess the long-term significance of such motion, we studied 439 patients undergoing Carpenter mitral reconstruction at our institution between March 1981 and June 1990. The hospital mortality rate was 4.8% (21/439) overall and 3.7% (9/243) for isolated mitral reconstruction. Systolic anterior motion was found in 6.4% (28/438) after the operation, and 2.3% (10/438) had a coexisting left ventricular outflow tract gradient (mean 53 mm Hg). Of the 28 patients with systolic anterior motion, 27 (96.4%) had leaflet prolapse, 17 (60.7%) had undergone more than a 3 cm resection of the posterior leaflet, and two (7.1%) had preexisting idiopathic hypertrophic subaortic stenosis. All patients were treated medically, 14 with negative inotropic agents. Follow-up echocardiograms at a mean of 32 months demonstrated the disappearance of systolic anterior motion in 13 of 28 patients (46.4%) and resolution of the outflow tract gradient in 10 of 10 (100%). At follow-up only one patient was in New York Heart Association class III or IV and required reoperation for rheumatic mitral insufficiency. These data demonstrate that systolic anterior motion after Carpentier mitral reconstruction with ring annuloplasty is not prevalent and should be managed medically in most cases. Associated left ventricular outflow tract obstruction resolves with medical treatment.     

Aortic elongation induced aortic stenosis (AEAS)

We present a case of a 71-year-old man who presented with aortic stenosis. This was pseudo-aortic obstruction resulting from the mitral valve subvalvular apparatus impacting into a normal aortic valve as a result of elongation of the ascending aorta. To place this case in context, we also provide a review of left ventricular outflow obstruction with an emphasis on subvalvular stenosis.     

Extended aortic root replacement with aortic allografts

Complex left ventricular outflow tract obstruction after operation for subaortic stenosis or with hypoplastic aortic anulus remains a challenge for pediatric cardiac surgeons. We have recently applied a new technique of extended aortic root replacement using a cryopreserved aortic allograft to treat two patients who had previously been operated on for subaortic stenosis and a third who had aortic stenosis with a hypoplastic aortic anulus. This new procedure combines the concept of aortoventriculoplasty with aortic root replacement and coronary artery reimplantation. The valved aortic homograft is used in place of an aortic valve prosthesis and the attached anterior mitral leaflet augments the interventricular septum to relieve the subvalvular left ventricular outflow tract obstruction. The coronary ostia are then reimplanted into the allograft and an anastomosis between the distal graft and the ascending aorta is completed. Allograft aortic tissue is then used to patch the right ventricular outflow tract. One patient had aortic stenosis with annular hypoplasia and did well after extended root replacement. Two patients had previous operations for subaortic stenosis before undergoing extended aortic root replacement. One required mediastinal exploration and drainage at 2 weeks for Serratia marcescens mediastinitis and bacteremia, but uncomplicated recovery followed. The other patient had complete heart block for 2 days, but normal sinus rhythm resumed and convalescence was benign. This modified technique with the aortic allograft was very helpful in treating these difficult problems, and the lack of mortality, limited morbidity, and good functional results are encouraging.     

Mitral annular reconstruction with anterior leaflet flip-over in concomitant surgery for mitral regurgitation associated with extensive posterior annular calcification and hypertrophic obstructive cardiomyopathy

We describe a case of severely calcified posterior mitral annulus associated with grade IV mitral re-gurgitation in addition to significant hypertrophic obstructive cardiomyopathy. A 70-year-old woman underwent successfully annular reconstruction with anterior mitral leaflet flip-over and mitral valve replacement with a bileaflet mechanical prosthesis combined with left ventricular septal myectomy. This technique can serve not only to cover the debrided posterior annulus, but also to eliminate left ventricular outflow tract obstruction and to keep left ventricular function by virtue of not severing ventricular-annular continuity.