Pannus Overgrowth Research Articles

Subacute Transcatheter CoreValve Thrombotic Obstruction

An 86-year-old man with severe symptomatic aortic stenosis (additive Euroscore 7) underwent a transcatheter aortic valve implantation with a CoreValve bioprosthesis (26 mm, CoreValve Revalving Technology, Medtronic, Inc., Minneapolis, MN). The patient was discharged on aspirin and clopidogrel and advised to stop the clopidogrel after 3 months. This first 6-month follow-up was uneventful. Repeated echocardiograms obtained during this period revealed a slight increase in mean transprosthetic aortic pressure gradient without significant concomitant aortic regurgitation. At the last visit, 1 year later, the patient became symptomatic (New York Heart Association class II–III). He had no fever. Between the 6th and 12th month of follow-up, there was a documented increase in transprosthetic aortic peak velocity (4.11 m/s) and mean gradient (41 mm Hg) and a significant reduction in aortic effective orifice area (0.69 cm2), which indicated severe prosthetic valve stenosis. To evaluate the shape of the CoreValve, both transesophageal echocardiogram and cardiac computed tomography were performed. Although computed tomography revealed no change in prosthesis position (when compared with pre–transcatheter aortic valve implantation computed tomography) and the absence of significant deformation of the stent by any calcifications (Figure 1A–1D), transesophageal echocardiogram evidenced thickened …

Blockage of a Mechanical Aortic Valve Leaflet with BioGlue: A Case Report

Mechanical aortic valve dysfunction is a very rare event and is usually due to thrombosis, pannus overgrowth, or both. BioGlue as a cause for such a complication has been reported only occasionally. We describe a case of a 63-year-old woman who underwent operation for symptomatic tight aortic stenosis. After implantation of an aortic valve (AGN-751, size 19; St. Jude Medical, St. Paul, MN, USA) because of a transverse tear of the aortic wall above the annulus occurring during the suturing of the aortotomy, a triangular Vascutek Dacron patch (Vascutek/Terumo, Inchinnan, Scotland, UK) was included. To secure hemostasis, BioGlue (CryoLife, Kennesaw, GA, USA) was applied. A transthoracic echocardiography (TTE) examination performed after signs of ischemia appeared in the electrocardiogram on postoperative day 5 revealed an aortic transvalvular gradient of 74/38 mm Hg and a functional valve area of 1.0 cm2. No coronary lesions were revealed in a coronarography evaluation, but cinefluoroscopy (CF) examination revealed immobility of 1 valve leaflet. The reoperation revealed a thick, rough layer of the glue on the inner side of the patch. This glue had run down to the valve, blocking a mechanical leaflet. Cleaning the valve was not possible, and the valve had to be changed. The subsequent postoperative course was uneventful. The transvalvular gradient was 39/20 mm Hg, and the functional valve area was 1.2 cm2. We believe that the use of BioGlue and other surgical sealants is justified to secure complex suture lines and for maintaining hemostasis in cardiac surgery, but some precautionary rules must be respected. Authors have indicated that the glue enters through the needle holes in such cases, but our findings suggest it can also pass to the Dacron patch itself. CF is superior to TTE and transesophageal echocardiography for analyzing movement of the mechanical valve leaflet, and cardiac catheterization is rarely needed.

Three‐Dimensional Imaging of Pannus Overgrowth after Mitral Valve Repair

We present the case of a 65-year-old man who was diagnosed with late mitral stenosis caused by pannus formation after Duran ring annuloplasty due to ischemicmitral regurgitation. Threedimensional echocardiography provided signifi cant information regarding the anatomy of the valve and the estimation of the severity of mitral stenosis.

A Rapid Structural Degeneration of a Porcine Mitral Valve

A 73-year-old woman underwent both mitral and aortic valve replacements with porcine heart valve prostheses because of severe mitral regurgitation and severe aortic regurgitation. Ten months after surgery, maximal flow velocity of the aortic valve reached 4.6 m/sec and moderate mitral regurgitation was detected. Repeated mitral and aortic valve replacements with mechanical heart valves were performed. The excised mitral valve showed thinning of the 3 cusps, and 2 of them were perforated. There was pannus overgrowth on the flow surface of the porcine aortic valve. Histologic examination of the excised mitral valve revealed marked inflammatory changes with macrophages.

Acute Dysfunction of Mechanical Aortic Valve as Electrocardiographic Mimic of Acute Left Main Coronary Artery Occlusion

We report three patients with acute dysfunction of mechanical aortic valve prosthesis resulting in chest pain, concomitant cardiogenic shock, and electrocardiographic changes mimicking acute occlusion of the left main coronary artery whereas emergency coronary angiography revealed normal coronary arteries. During operation, abnormal proliferation of subvalvular pannus overgrowth on the inflow aspect of the prosthesis was found to impede normal prosthesis closure. We discuss the possible underlying mechanisms of electrocardiographic presentations.

Cuspal Dehiscence at a Post and Along the Stent Cloth in a Bovine Pericardium Heart Valve Implanted for Seven Years

A failing mitral valve prosthesis made from bovine pericardium was explanted from a 50-year-old patient. Preoperative transthoracic-echocardiography had confirmed severe mitral regurgitation due to structural failure of this HP Bio bovine pericardium heart valve prosthesis. The explanted device was examined macroscopically, by scanning electron microscopy (SEM), by light microscopy, and by transmission electron microscopy (TEM). Samples of unassembled patches of bovine pericardium were used as a pre-implantation control to better understand the changes that occurred in the structure of the pericardium following the 7 years of implantation. Examination confirmed complete dehiscence of a cusp along a valve post and the stent: This detached cusp was observed floating in the bloodstream at echocardiography. The fibrous pannus overgrowth was well developed along the stent and extended to the bottom of the cusps both on the inflow and the outflow sides. The fibrous panni were found to be poorly adhesive to the pericardium cusps and had become stiff, thus impairing the opening and closure of the valve. The structure of the pericardium cusps was severely deteriorated compared to the control bovine pericardium tissue samples. The collagen bundles were frequently broken and more stretched in the explanted device, lacking the wavy histological pattern of normal collagen fibers. However, the tissues were devoid of any calcification. In conclusion, the failure mode of this valve was the dehiscence of a cusp from a valve post and along the stent cloth in the absence calcification.

Starr-Edwards valves at the aortic and mitral positions implanted for 39 years

Cloth-covered Starr-Edwards caged ball valves implanted in the aortic and mitral valve positions for 39 years were extracted. Both showed valve dysfunction resulting from pannus overgrowth. The metal cages of the Starr-Edwards valves were covered with worn cloth. This case indicates the extended durability of Starr-Edwards valves and the importance of the design and materials of prosthetic heart valves to avoid pannus overgrowth and prosthetic valve abrasion.

Paroxysmal mechanical aortic valve prosthesis dysfunction: capturing the right moment

A 62-year-old female presented to the emergency room under suspicion of acute myocardial infarction. While shopping she suddenly experienced severe chest pain and nearly collapsed. Her medical history revealed aortic valve replacement (Medtronic Hall 22 mm) 8 years before and since 5 years repeated presentations to the emergency room because of intermittent chest pain. An initial electrocardiogram (ECG) showed sinus tachycardia with transient ST elevation in leads aVR and V1 and ST depression in leads I, II, III, aVF and V3–V6 (Fig. 1), which resolved within 5 min. Physical examination, laboratory results and transthoracic echocardiography were unremarkable. Fig. 1 ECG at presentation during chest pain, showing sinus tachycardia with ST elevation in leads aVR and V1 and ST depression in leads I, II, III, aVF and V3-V6 Under suspicion of an acute coronary syndrome, coronary angiography was performed and showed a 70% stenosis in the second diagonal branch of the left descending artery. Because of the discrepancy between the ECG at presentation and the coronary angiography, it was decided not to perform a percutaneous coronary intervention. Immediately after the coronary angiography the patient had recurrent chest pain with remarkable ST depression. A second coronary angiography was performed which revealed non-closure of the mechanical aortic valve, causing severe aortic regurgitation (Movies 1 and 2). The patient was scheduled for valve revision. At operation dysfunction of the mechanical disk became apparent. When the disk was opened a pannus overgrowth beneath the valve was clearly visible. This was causing a block of the disk in opening position with temporarily massive aortic regurgitation (Fig. 2). After removing the mechanical prosthesis, the circular pannus overgrowth was most evident (Fig. 3). The pannus was removed and a bioprosthesis (Edwards Life Sciences Perimount Magna 23 mm) was implanted. The patient made an uncomplicated recovery. She has had no recurrent chest pain 5 months after the valve replacement. Fig. 2 The mechanical prosthesis is opened. A pannus overgrowth is visible behind the prosthesis (indicated by arrows). AO: ascending aorta Fig. 3 After removing the mechanical prosthesis, the circular pannus is entirely visible (indicated by arrows) Intermittent severe aortic regurgitation due to pannus overgrowth of a mechanical prosthetic aortic valve is a serious complication and has been reported before [1–4]. The clinical presentation is varied and due to the intermittent appearance of the malfunctioning valve, the diagnosis is often difficult and can be easily overlooked. In this specific patient it was possible to diagnose this clinical problem due to the findings on angiography. However, simple cinefluoroscopy of the mechanical valve during symptoms would have diagnosed mechanical valve immobility earlier.

Unusual 25-Year Durability of an Ionescu-Shiley Pericardial Bioprosthesis

Ionescu-Shiley valve was withdrawn from clinical use in 1987 for its early structural failure after implantation. This was due to valve design rather than the natural properties of bovine pericardium itself. We describe the unexpected 25-year survival of an Ionescu-Shiley bioprosthesis in the mitral and tricuspid positions, implanted to treat endomyocardial fibrosis. This report makes 2 important points: (1) pannus overgrowth may be a favorable determinant of the durability of xenografts, and (2) bovine pericardial valves may have excellent hemodynamic performance and tissue durability for more than 20 years in the mitral position even in young patients.

Calcification of allograft and stentless xenograft valves for right ventricular outflow tract reconstruction: An experimental study in adolescent sheep

Aortic homografts were compared with pulmonary homografts in the setting of right ventricular outflow tract reconstruction in adolescent sheep. Furthermore, clinically available stentless porcine and bovine xenografts were studied as an alternative to homografts. In 51 adolescent sheep cryopreserved aortic and pulmonary (ovine) homografts, as well as 6 different types of clinically available stentless bioprostheses (Prima Plus, Toronto SPV, Toronto BiLinx, Freestyle, Pericarbon Stentless, and Contegra) were implanted in the pulmonary position. After 5 to 6 months, the valves were explanted and studied for structural valve degeneration by means of radiographic analysis, histology, and calcium content determination. Pulmonary homografts calcified significantly less than aortic homografts in the wall portion. Leaflet calcification was mild, hardly detectable on radiographic analysis, and comparable between aortic and pulmonary homografts. Stentless porcine xenografts showed severe calcification in the aortic wall portion, irrespective of the antimineralization treatment. Leaflet calcification was mild and in the range of that seen in homografts. Pannus formation was present but never induced leaflet retraction or cusp immobilization. Calcification was absent in the stentless Pericarbon valve implants, but all valves showed extensive pannus overgrowth, leaflet retraction, and cusp immobilization. The Contegra valves showed wall calcification, but the leaflets were completely free of calcification and pannus. For right ventricular outflow tract reconstruction, the pulmonary homograft remains the first choice. All xenografts result in either calcific degeneration or cusp immobilization.

Obstruction of St. Jude Medical Valves in the Aortic Position: Plasma Transforming Growth Factor Type Beta 1 in Patients With Pannus Overgrowth

The study investigated the hypothesis that plasma transforming growth factor type beta 1 (TGF-beta1) initiated pannus overgrowth in cases with aortic prosthetic valve dysfunction (PVD). Patients with obstruction of an aortic St. Jude Medical valve in 26 cases (PVD group) and without obstruction in 48 cases (control group) were studied. Plasma TGF-beta1, the intensity of the prothrombin time-international normalized ratio (PT-INR), and the interruption of an oral anticoagulant medicine were conducted. Plasma TGF-beta1 levels in the PVD group (87.7 +/- 29.2 ng/mL) were significantly higher (P < 0.05) than in the control group (73.7 +/- 25.2 ng/mL). The interruption of an oral anticoagulant medicine in 54% of the PVD group versus 12% of the control group was identified (P < 0.001). The mean value of the PT-INR in the PVD group (1.75 +/- 0.30) and control group (1.75 +/- 0.30) was not significantly different (P = 0.82). In conclusion, elevated levels of plasma TGF-beta1 may play a role in pannus overgrowth.

Explantation of a 44-year-old Starr–Edwards mitral valve for delayed hemolysis

FIGURE 1. Starr–Edwards 44-year-old explanted mitral valve, model 6120, with sewing ring removed. Valve is intact, with yellowing of ball. CLINICAL SUMMARY A 68-year-old woman was admitted 44 years after undergoing mitral valve replacement with a Starr–Edwards (SE) prosthesis (Edwards Lifesciences, Irvine, Calif) for rheumatic mitral valve stenosis. Since implantation of the prosthesis in 1965 via thoracotomy, the patient had done well and maintained her anticoagulation with warfarin sodium (Coumadin). She now had fatigue and anemia. Of note, 2 years earlier the patient had had third-degree heart block necessitating the implantation of a dual-chamber pacemaker. A full workup including upper and lower endoscopy did not reveal a source of bleeding. Hematologic testing showed decreased haptoglobin, a high lactic dehydrogenase value, and increased reticulocyte count, consistent with a hemolytic anemia. Bone marrow biopsy was performed, which showed erythroid hyperplasia, normocellular bone marrow, normal megakaryocytes, and absent iron, indicative of iron deficiency anemia. Despite iron replacement therapy she continued to become increasingly transfusion dependent. She received 9 units of blood in 1 month alone. Echocardiogram revealed normal prosthetic mitral valve function with a mitral valve mean gradient of 6 mm Hg, a severely calcified aortic valve with an aortic valve mean gradient of 58 mm Hg, and an aortic valve area of less than 1.0 cm. Aortic and mitral valve replacements were performed with bioprosthetic valves. Reoperative median sternotomy was performed. After standard cannulation, Sondergaard’s groove was used to expose the mitral valve. The SE valve was in good condition without paravalvar leak. The mitral valve was explanted. The SE ball and cage were undamaged (Figure 1). There was no evidence of cloth tears or pannus overgrowth. The color of the ball had changed, presumably from lipid infiltration, but the ball was otherwise without pitting or defects. The patient underwent successful aortic valve replacement with a 21-mm Edwards Magna Thermafix bovine pericardial valve (Edwards) and mitral valve replacement with a 25-mm St Jude Epic porcine valve (St Jude Medical, Inc, St Paul, Minn). The patient was discharged

Diagnosis of the prosthetic heart valve pannus formation with real-time three-dimensional transoesophageal echocardiography

Prosthetic heart valve obstruction (PHVO) caused by pannus formation is an uncommon but serious complication. Although two-dimensional transesophageal echocardiography (2D-TEE) is the method of choice in the evaluation of PHVO, visualization of pannus is almost impossible with 2D-TEE. While demonstrating the precise aetiology of PHVO is essential for guiding the therapy, either thrombolysis for valve thrombosis or surgery for pannus formation, more sophisticated imaging techniques are needed in patients with suspected pannus formation. We present real-time 3D-TEE imaging in a patient with mechanical mitral PHVO, clearly demonstrating pannus overgrowth.

Pannus overgrowth after mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis

A Carpentier-Edwards pericardial (CEP) bioprosthesis was explanted from an 81-year-old woman due to nonstructural dysfunction 9 years after mitral valve replacement. The nonstructural dysfunction produced severe regurgitation in the mitral position. During the surgery, excessive pannus overgrowth was seen on the left ventricular side of the CEP bioprosthesis. Pannus overgrowth was prominent on one leaflet. That leaflet was stiff and shortened due to the excessive overgrowth of pannus. In this patient, the distortion of one leaflet was the main reason for transvalvular leakage of the CEP bioprosthesis in the mitral position. A new CEP bioprosthesis was implanted in the mitral position. Pathological analysis revealed fibrotic pannus with a small amount of cellular material over the leaflets of the resected CEP valve. This change was marked on the distorted leaflet.

Intermittent acute aortic regurgitation of a mechanical bileaflet aortic valve prosthesis: diagnosis and clinical implications

Intermittent aortic regurgitation (AR) is an unusual complication after a mechanical prosthetic replacement. We describe a rare case of intermittent dysfunction of a bileaflet mechanical aortic prosthetic valve in a 41-year-old man with a 21 mm Tri-technologies prosthetic valve implanted 4 years before. Transthoracic echocardiography (TTE) before discharge was normal and prosthesis-patient mismatch was ruled out. He was admitted to our hospital because of mild dyspnoea at effort. TTE revealed acute and severe intermittent AR. The patient underwent surgery, during which abnormal proliferation of subvalvular pannus overgrowth on the inflow aspect of the prosthesis was found impeding the normal closure of one of the discs of the prosthesis. The pannus formation was resected, the Tri-technologies prosthetic valve was prophylactic explanted and a 23 mm St Jude Medical bileaflet mechanical prosthesis valve was implanted. We describe the role of TTE and the limitation of the cinefluoroscopy in the diagnosis of Tri-technologies prosthetic dysfunction.

Mitral Valve Stenosis Caused by Abnormal Pannus Extension over the Prosthetic Ring and Leaflets After Duran Ring Mitral Annuloplasty

We treated a 61-year-old woman with mitral stenosis caused by pannus formation after Duran ring annuloplasty. Pannus overgrowth on the ring with extension onto both leaflets narrowed the mitral orifice and severely restricted the mobility of the valve leaflets. Mitral valve replacement with a St. Jude Medical mechanical heart valve prosthesis was successfully performed, and the postoperative course was uneventful. Patients undergoing Duran ring annuloplasty should be followed up with the consideration of possible mitral stenosis caused by pannus extension, as the cause for pannus formation remains unclear.

Cyclic Intermittent Aortic Regurgitation of a Mechanical Bileaflet Aortic Valve Prosthesis: Diagnosis and Clinical Implications

We describe a rare case of intermittent dysfunction of a bileaflet mechanical aortic valve prosthesis. Subvalvular pannus overgrowth on the inflow aspect of the prosthesis impeded normal closure of one leaflet causing severe aortic regurgitation, which occurred intermittently. The complementary role of transthoracic and transesophageal echocardiography and cine-fluoroscopy in the diagnosis of this case is described.

Mechanical Aortic and Mitral Valve Replacement in Infants and Children

The aim of this study was to evaluate early and late outcomes after mechanical systemic heart valve replacement in pediatric patients. Between October 1981 and December 2003, 32 children (mean age 7.2 +/- 5.4 years; 4 months - 15.9 years) underwent mechanical mitral (MVR, n = 17), aortic (AVR, n = 13) or double valve replacement (DVR, n = 2) with St. Jude Medical valves. Twenty-two patients (69 %) had undergone previous cardiac surgery. Anticoagulation self-management was used since 1995. The operative mortality was 3.1 %. Perioperative complications were complete heart block (n = 5), ventricular fibrillation (n = 1) and myocardial infarction (n = 1) and were exclusively related to patients with MVR. Mean calculated valve size ratio (geometric prosthesis orifice area/normal valve size area) was 1.72 (1.07 - 2.85) for AVR and 1.4 (0.88 - 3.12) for MVR. Mean follow-up was 9.1 +/- 6.6 years (range 0.4 - 23.2 years, cumulative 283 patient-years). There were two late deaths in patients with MVR. Actuarial survival after 10 years was 93.8 %. Late complications were endocarditis (n = 2), minor hemorrhagic event (n = 1), and stroke (n = 1). Anticoagulation self-management is well accepted by all patients/parents. Overall 10-year freedom from any anticoagulation-related adverse event with phenprocoumon was 89.1 % (1.2 %/patient year). Nine patients required reoperations: redo-MVR (outgrowth of prostheses (n = 3), pannus overgrowth (n = 2), closure of paravalvular leak after AVR (n = 2), partial aortic valve thrombosis (n = 1) and redo-DVR (n = 1 for endocarditis). Freedom from reoperation after 10 years was 80.9 %. Mechanical valve prostheses are a valuable option for left-sided heart valve replacement in pediatric patients. Perioperative morbidity was exclusively related to patients with MVR. Oversizing was often possible to avoid early reoperation for outgrowth. The operative mortality and long-term morbidity are acceptable. Anticoagulation self-management is safe and well accepted.

Invited commentary

Today’s treatment of complex congenital cardiovascular defects of the right ventricular outflow tract, such as hypoplastic, stenotic right ventricular outflow tract, or the pulmonary artery in tetralogy of Fallot, are far from optimal as generally nonviable patch materials are used. This results in repeated surgical intervention for two reasons. First, the patch reconstruction and the absence of a functional pulmonary valve will lead to right ventricular failure, increased tricuspid valve regurgitation, and ventricular arrhythmias. Second, material degeneration will result in obstructive pannus overgrowth and calcification after implantation. Tissue engineering can overcome these disadvantages using a biodegradable scaffold that can be in vitro or in vivo re-cellularized to allow regeneration, remodeling, and growth potential. The present study by Fujimoto and colleagues [1Fujimoto K.L. Guan J. Oshima H. Sakai T. Wagner W.R. In vivo evaluation of a porous, elastic biodegradable patch for reconstructive cardiac procedures.Ann Thorac Surg. 2007; 83: 648-654Abstract Full Text Full Text PDF PubMed Scopus (106) Google Scholar] compared an elastomeric, biodegradable polyester urethane urea (PEUU) patch with a generally used expanded polytetrafluoroethylene (e-PTFE) patch implanted into the right ventricular outflow tract. This study, performed in the rat model, showed the superiority of the PEUU patches compared with the e-PTFE patches. The PEUU material showed high elasticity and strength and porous scaffold, allowing host fibroblast to grow into the scaffold and active synthesize collagen. In contrast there was no host cell ingrowth in the e-PTFE patch. Furthermore the PEUU scaffold was nearly completely absorbed after 12 weeks of implantation. Therefore the authors need to be congratulated for this performed study as the goal of tissue engineering has almost been completely achieved. Regeneration and remodelling potential of this biodegradable patch has been proven. Future studies will be needed, eventually in the larger animal model, to show growth potential as suggested by the authors. The impact of the biodegradable patch implanted into the right ventricular outflow tract needs to be discussed. At this early stage of right ventricular outflow tract treatment, pulmonary allografts show fast tissue degeneration and (due to the absence of viability) an outgrowth of the valve size by the patient after a short period of time. Therefore patch reconstruction of the right ventricular outflow tract is generally used to bridge the patient until a reasonable valve size can be implanted. Quality of life is limited for the patient until a valve has been implanted not to overestimate the right ventricular function. For this reason, tissue engineering should concentrate on developing a valve with regeneration, remodeling, and growth potential to overcome patch reconstruction and to allowing one-stage surgical treatment. The area of interests for biodegradable patch use would be more of those complex congenital heart diseases without the need of a valve function such as repair of complete atrioventricular communication, the Fontan procedure, enlargement of the aorta in the Norwood I procedure, or complex repair of coarctation of the thoracic aorta. In Vivo Evaluation of a Porous, Elastic, Biodegradable Patch for Reconstructive Cardiac ProceduresThe Annals of Thoracic SurgeryVol. 83Issue 2PreviewSeveral synthetic materials have been used for cardiac reconstruction in patients with complex congenital heart defects. These materials are not viable, do not grow with children, and may necessitate reoperation. We report here on the cardiac implantation of a recently developed, degradable porous material designed to facilitate cellular ingrowth during the healing process. Full-Text PDF

The case of an explanted 16-year-old mitral Carpentier-Edwards pericardial bioprosthesis

We report the case of a mitral Carpentier-Edwards pericardial bioprosthesis that was explanted from a 43-year-old female patient because of structural valve deterioration 16 years following implantation. Upon removal, the prosthesis was found to be discolored and all leaflets were stiff and hard, showing extensive calcification, pannus overgrowth, leaflet hematoma, and multiple disruptions. One leaflet presented a wavy free margin due to commissural disruptions, leading to incomplete cusp coaptation. The accumulated physical symptoms of the patient were consistent with these findings.