Reoperations for left-sided low-profile mechanical prosthetic obstructions

Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients

BACKGROUND

Dysfunction of mechanical heart valve prostheses is an unusual but potentially lethal complication after mechanical prosthetic valve replacement. We seek to report our experience with mechanical valve dysfunction regarding etiology, surgical techniques and early outcomes.

METHODS

Clinical data of 48 patients with mechanical valve dysfunction surgically treated between October 1996 and June 2011 were analyzed.

RESULTS

Mean age was 43.7±10.9 years and 34 were female (70.8%). The median interval from primary valve implantation to dysfunction was 44.5 months (range, 1 hour to 20 years). There were 21 emergent and 27 elective reoperations. The etiology was thrombosis in 19 cases (39.6%), pannus in 12 (25%), thrombosis and pannus in 11 (22.9%), improper disc orientation in 2 (4.1%), missing leaflet in 1 (2.1%), excessively long knot end in 1 (2.1%), endogenous factor in 1 (2.1%) and unidentified in 1 (2.1%). Surgical procedure was mechanical valve replacement in 37 cases (77.1%), bioprosthetic valve replacement in 7 (14.9%), disc rotation in 2 (4.2%) and excision of excessive knot end in 1 (2.1%). Early deaths occurred in 7 patients (14.6%), due to low cardiac output in 3 (6.3%), multi-organ failure in 2 (4.2%) and refractory ventricular fibrillation in 2 (4.2%). Complications occurred in 10 patients (20.8%).

CONCLUSIONS

Surgical management of mechanical valve dysfunction is associated with significant mortality and morbidity. Earlier identification and prompt reoperation are vital to achieving better clinical outcomes. The high incidence of thrombosis in this series highlights the need for adequate anticoagulation and regular follow-up after mechanical valve replacement.

Prevalence of pannus formation after aortic valve replacement: clinical aspects and surgical management

Pannus formation after aortic valve replacement is not common, but obstruction due to chronic pannus is one of the most serious complications of valve replacement. The causes of pannus formation are still unknown and effective preventive methods have not been fully elucidated. We reviewed our clinical experience of all patients who underwent reoperation for prosthetic aortic valve obstruction due to pannus formation between 1973 and 2004. We compared the initial 18-year period of surgery, when the Björk-Shiley tilting-disk valve was used, and the subsequent 13-year period of surgery, when the St. Jude Medical valve was used. Seven of a total of 390 patients (1.8%) required reoperation for prosthetic aortic valve obstruction due to pannus formation. All seven patients were women; four patients underwent resection of the pannus and three patients needed replacement of the valve. The frequency of pannus formation in the early group was 2.4% (6/253), whereas it was 0.73% (1/137) in the late group (P < 0.05). Pannus was localized at the minor orifice of the Björk-Shiley valve in the early group and turbulent transvalvular blood flow was considered to be one of the important factors triggering its growth. We also consider that small bileaflet valves have the possibility of promoting pannus formation and that the implantation of a larger prosthesis can contribute to reducing the occurrence of pannus.

Thrombolytic therapy with recombinant streptokinase for prosthetic valve thrombosis

BACKGROUND

Thrombosis is a serious complication of prosthetic heart valves, and management is often difficult. Thrombolytic therapy is a promising alternative to valve re-operation in the prosthetic valve thrombosis.

METHODS

Fifteen consecutive patients with prosthetic heart valve thrombosis (10 mitral, 3 aortic, 2 tricuspid) were treated with intravenous recombinant streptokinase: 250,000 UI given over 30 minutes followed by an infusion an 100,000 UI per hour, always with clinical monitoring and echocardiographic examinations repeated at 24, 48, and 72 hours after starting thrombolytic therapy. Doppler echocardiography was the primary method use for diagnosis and was also used to follow the response to therapy

RESULTS

Fibrinolytic treatment was successful in 14 (93.3%) patients. Total response was achieved in 13 (86.6%)patients and partial response in 1 (6.7%) patient; one patient died of ventricular fibrillation. No major hemorrhagic events were observed, peripheral embolism occurred in two cases, and one case of minor peripheral bleeding occurred in another. Some patients experienced fever and chills.

CONCLUSIONS

The present study demonstrates the feasibility, safety and efficacy of thrombolytic therapy, which may be considered as first-line therapy for prosthetic heart valve thrombosis.

Acute thrombotic obstruction of mitral valve prosthesis: low protein C level

A 51-year-old female underwent redo mitral valve replacement with a pericardial bioprosthesis because of acute thrombotic obstruction of a mechanical valve, in spite of adequate anticoagulation with warfarin. Her protein C level was 24% of the normal value and protein S was reduced to 54% of normal.

Mechanical Prosthetic Valve Thrombosis: Case Report and Review of the Literature

Mechanical prosthetic valve thrombosis is a life-threatening complication necessitating immediate intervention. The presenting signs and symptoms of this illness are somewhat variable, but physical examination and transesophageal echocardiography enable rapid diagnosis. To avoid catastrophic complications, valve replacement or debridement, or thrombolysis in the correct setting, must be performed without delay. It is not entirely clear which therapy is superior. For any given patient, the risks of thrombolytic therapy, including bleeding, systemic embolism, and failure to restore valvular function, must be weighed against the risks of surgical intervention. Once the decision is made to operate, the choice of valve replacement versus debridement is one best made intraoperatively, upon visual inspection of the valve apparatus. Despite aggressive therapy, morbidity and mortality from prosthetic valve thrombosis and its treatment are not trivial. Fortunately, with current prosthetic devices and aggressive prophylactic anticoagulation, the incidence of prosthetic valve thrombosis remains low. Antiplatelet therapy may offer additional benefit to patients being prophylaxed with warfarin. This report details the case of a woman with aortic and mitral prosthetic valves who presented with heart failure and evidence of severe aortic prosthetic dysfunction after a period of suboptimal anticoagulation. She successfully underwent debridement of the mitral prosthesis and replacement of the aortic valve. The relevant literature is reviewed.

Choosing a prosthetic heart valve

Although most of the available prosthetic heart valves function remarkably well, the variety of available choices attests to the inability of any single one to fulfill the requirements of the ideal valve substitute. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves available in the United States are the Carpentier-Edwards and Hancock porcine heterograft valves and the Carpentier-Edwards pericardial valve. Review of several large comparative studies on valve performance reveals that the overall results with tissue and mechanical valves are about equal at the end of 10 years. The characteristics of each type of valve substitute dictate the selection of one prosthesis in preference to others for a particular patient. Mechanical prostheses are recommended for patients without contraindications for anticoagulants. Tissue valves are reserved for patients over 65 years of age or for patients in whom anticoagulation is contraindicated. Multiple other patient-related factors need to be considered in selecting the appropriate valve, including the psychosocial situation and patient preference.

[Refibrinolysis with r-tPA for thrombosis of the mitral prosthesis after an acute myocardial infarct]

We report the case of a 62-year-old patient with a mitral prosthesis hospitalized with an anterior acute myocardial infarction who was treated with r-tPA. Some days later, the patient had mitral thrombosis with heart failure. Because of the high risk of surgical intervention, he was successfully treated with a new dose of r-tPA.

Left atrial spontaneous echo contrast in asymptomatic patients with a mechanical valve prosthesis

BACKGROUND

Valve thromboembolism may be a fatal complication of mechanical valve prosthesis if detected late. Spontaneous echo contrast (SEC) is a well-documented prothrombotic phenomenon; here we report it in asymptomatic patients with a mechanical valve prosthesis.

METHODS

Ninety-two asymptomatic patients with a mechanical valve prosthesis for underlying rheumatic heart disease underwent transesophageal echocardiography. Appendage area, peak filling and emptying velocities of the left atrial appendage, and the presence or absence of SEC and thrombi were determined. The results of 56 patients without SEC or thrombi (group I) were compared with those of 24 patients with SEC and no thrombi (group II) and 12 patients with thrombi (group III).

RESULTS

Spontaneous echo contrast was present in 39% of the asymptomatic patients with a mechanical valve prosthesis. Although 12 patients had cardiac thrombi, including valve thrombi in 4, no patients presented symptoms. Anticoagulant therapy had no significant association with SEC and atrial thrombi. There was a significantly greater prevalence of atrial fibrillation and mitral prosthesis in groups II and III than in group I. Two patterns of left atrial appendage flow were identified: one was organized biphasic flow with peak filling velocities of 41.2 +/- 17.2 cm/s and emptying velocities of 40.5 +/- 17.5 cm/s. The other showed irregular, very low peak filling velocities (104 +/- 11.5 cm/s) and emptying velocities (12.3 +/- 13.1 cm/s). The former flow pattern was associated with sinus rhythm and the latter form was associated with atrial fibrillation.

CONCLUSIONS

There was a relatively high prevalence of SEC and thrombi in patients with a mechanical valve prosthesis. Patients with a valve prosthesis may not have clinical symptoms. Anticoagulation intensity was not associated with the occurrence of SEC and thrombi. Patients with the mitral valve prosthesis and atrial fibrillation were identified as a high-risk of subgroup for the development of SEC and thrombi.

Hemodynamic stabilization of acute prosthetic valve thrombosis using percutaneous catheter manipulation

Thrombosis of a tilting-disk prosthetic heart valve can be an acute and potentially life-threatening problem. Surgical thrombectomy, valve replacement, or systemic thrombolytic agents have been successfully employed in the management of such cases. Some patients, however, may not survive the acute episode long enough to receive definitive surgical therapy. For such patients, temporary hemodynamic stabilization might be achieved by re-establishing partial valve disk mobility. This report describes a technique for re-establishing valve disk mobility in an acutely compromised patient by using a percutaneously introduced "rigid" catheter to manipulate an entrapped tilting-disk valve in the aortic position.

Evaluation of St. Jude Medical mitral valve function by exercise Doppler echocardiography

The aim of this study was to detect borderline mitral valve dysfunction in 100 asymptomatic patients with a St. Jude Medical valve. We studied rest and exercise hemodynamics by Doppler echocardiography. Study patients were divided into two groups according to the time since surgery: group A had valves implanted less than 5 years ago (44 patients), group B had valves implanted more than 5 years ago (56 patients). Although patients had no clinical signs of valve dysfunction, group B was found to have significant reduction of mitral valve area (p < 0.05). In the group A patients, mean gradients at rest increased from 4 +/- 2, 4 +/- 2, and 3 +/- 1 mmHg in valve sizes of 25, 27, and 29 mm, respectively, to 7 +/- 2, 7 +/- 3, and 5 +/- 2 mmHg with exercise. In the group B patients, mean gradients at rest increased from 7 +/- 1, 6 +/- 2, and 5 +/- 1 mmHg to 14 +/- 3, 13 +/- 3, and 10 +/- 4 mmHg, respectively, after exercise. The percent increase (mean) in peak pressure gradient with exercise was significantly higher in group B (more than 100%) than in group A (less than 80%) (p < 0.01). The percent increase in mean gradient with exercise was also significantly higher in group B (more than 100%) than in group A (less than 75%). In conclusion, patients with reduced valve area and more than a 100% increase of peak and mean gradients should be followed up carefully. If any signs or symptoms of heart failure develop, they must be considered as candidates for surgery.

Thrombolysis in left-sided prosthetic valve occlusion: immediate and follow-up results

Thrombolytic therapy is used increasingly for prosthetic valve thrombosis. Fear of peripheral embolism has limited its use in left-sided valve occlusions. Thirty-eight patients with prosthetic valve occlusion were treated with thrombolytic agents on 44 occasions. Duration of thrombolytic therapy was individualized. Patients were followed up with clinical, echocardiographic, and cine-fluoroscopic evaluation. Average time from onset of symptoms to presentation was 9.7 days. The anticoagulation status was inadequate in 70% of instances. The majority (75%) were in functional class IV, 8 of them being in shock. Overall success was seen in 88.6%: immediate complete success in 18 and partial in 21. Nine of those with partial success had delayed opening of the leaflets. There were nine instances of rethrombosis and one instance of re-rethrombosis; 6 patients received repeat thrombolysis with success in 5. Seventy-six percent (29/38) of the patients were surviving at the time of reporting. In conclusion, the present study demonstrates the feasibility of thrombolytic therapy for left-sided prosthetic valve occlusion. Delayed opening is common in patients with initial partial success. Rethrombosis remains a major problem.

Massive pulmonary hemorrhage complicating mitral prosthetic valve obstruction

A case is reported of prosthetic mitral valve obstruction in a patient who had had three hospital admissions with massive hemoptysis. A diagnosis was finally made after two-dimensional echocardiography with Doppler and cardiac catheterization were performed. The patient was successfully treated with re-replacement of the valve. Any new pulmonary or cardiac symptom in a patient with a prosthetic valve requires prompt evaluation and treatment.

The St. Jude valve. Thrombolysis as the first line of therapy for cardiac valve thrombosis

BACKGROUND

Thrombolytic therapy is a promising alternative to valve replacement in the management of prosthetic valve thrombosis. We sought to determine the short- and long-term results of treating thrombosed St. Jude heart valves with thrombolytic therapy as the primary treatment modality.

METHODS AND RESULTS

Between March 1978 and December 1991, 988 patients underwent implantation of St. Jude prosthetic valves at our medical center, and all patients with thrombosed valves were identified prospectively. During this period, 17 patients (13 women; mean age, 66.8 +/- 19.0 years) developed prosthetic valve thrombosis (11 aortic, six mitral). In six patients, Coumadin was stopped in preparation for elective surgery. The clinical presentation was congestive heart failure in 13, syncope and fatigue in two, and a cerebrovascular accident in one; one patient was asymptomatic. The average duration of symptoms was 11.7 +/- 12.0 days (range, 1-45 days). Anticoagulation was subtherapeutic in all but one patient at the time of presentation. Cinefluoroscopy was the primary method used for diagnosis and was also used to follow the response to therapy. Twelve patients were treated medically (10 with thrombolytic therapy and two with heparin), three were treated surgically, and two were diagnosed at autopsy. Of the 12 medically treated patients, 10 had marked improvement in leaflet movement and symptoms within 12 hours. Thus, 10 of 12 patients (83%) had a satisfactory response to medical therapy alone. No medically treated patient died or had a major complication resulting in permanent damage. However, four of the 12 medically treated patients had minor complications, including a transient episode of facial weakness in one patient, hematomas in two, and epistaxis in one. Late rethrombosis recurred in two patients in the medically treated group and was successfully retreated with thrombolytic therapy. At 3 months, all patients were alive and well.

CONCLUSIONS

Thrombolytic therapy can be used as the first line of therapy for thrombosed St. Jude valves with a low risk of permanent side effects and excellent chances of success. In most cases, surgery can be reserved for patients who do not respond to thrombolytic therapy.

Obstruction of mechanical heart valve prostheses: clinical aspects and surgical management

One hundred patients (32 male) aged 5 months to 82 years (median 32 years) underwent 106 surgical procedures for 112 mechanical prosthetic valves obstructed by a thrombus (n = 61) or pannus (n = 7), or both (n = 44), between January 1, 1980 and December 31, 1989. The position of the obstructed prosthesis was aortic in 51 patients (48%), mitral in 49 (46%) and both aortic and mitral in 6 (6%). The types of obstructed prosthetic valves were Björk-Shiley (n = 51), St. Jude (n = 41) and Medtronic-Hall (n = 20). The time interval between valve replacement and obstruction ranged from 6 weeks to 13 years (median 4 years). Of 63% of patients in whom coagulation variables were available at the time of obstruction, 70% were receiving inadequate anticoagulant therapy. In 63% of the procedures the patient was in New York Heart Association functional class IV. Two patients underwent preoperative thrombolysis with incomplete results. Operative procedures included valve replacement (n = 81), valve declotting and excision of pannus (n = 23) and aortic valve replacement and mitral valve declotting (n = 2). The early mortality rate was 12.3% (13 patients), and there was no difference between surgery for mitral prostheses (12.2%) versus aortic prostheses (13.7%). The perioperative mortality rate was 17.5% (11 of 63 patients) in patients in functional class IV and 4.7% (2 of 43 patients) in those in functional classes I to III (p less than 0.05). For valve replacement, the mortality rate was 12% (10 of 81 patients) and for declotting of the prosthesis 13% (3 of 23 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical considerations for avoiding disc interference based on a ten-year experience with the Medtronic Hall heart valve

All low profile valves are susceptible to problems related to implant technique, especially immobilization of the occluder. Because the disc-valve-ring clearance may be only a fraction of a millimeter, this complication is a small yet ever present possibility of which the surgeon must be aware. Special care must be taken when implanting low profile valves to eliminate the possibility of disc interference caused by suture ends or intracardiac structures. The surgeon can minimize the risk of disc immobilization by careful attention to precautionary surgical measures described herein.