Adriana Luk

Modes of Failure in Explanted Mitroflow Pericardial Valves

BACKGROUND Bioprosthetic heart valves are a treatment option for patients with significant valvular disease. We present the first morphologic analysis of a series of explanted Mitroflow pericardial valves (model A12) and discuss their modes of failure. METHODS Between 2001 and 2010, 12 Mitroflow (A12) valves (Sorin Group Inc, Vancouver, Canada) were examined, grossly and microscopically, for postimplantation changes. Cusp tears and thickening, calcification (at radiography), pannus formation, inflammation, and thrombus deposition were noted. Microscopically, tissue degeneration including the presence of calcification, pannus formation, thrombus, collagen disruption, fluid insudation, inflammatory cells, and microorganisms were looked for. Causes for dysfunction were then identified. RESULTS There were 12 patients with a mean age of 73.0 ± 5.3 years at implantation. Duration of implantation ranged from 0.25 to 7 years (mean = 2.9 ± 2.5 years). Five valves were explanted for infective endocarditis or thrombotic vegetations. Primary structural deterioration was observed in 7 of 12 (58%) valves; characterized by para-stent post cusp tears (42%) and moderate to severe calcification (50%). Most valves showed cusp thickening and collagen disruption at the stent post and pannus. CONCLUSIONS Structural valve deterioration was observed in 100% of the Mitroflow pericardial valves that had been in place for more than 2 years. The high rate of para-stent post cusp tears, calcification, and tissue degeneration suggests a link to the design, likely associated with mechanical stress, in addition to abrasion with the cross-sutures and Dacron fabric at the stent posts.

Drug-related cardiac pathology

Many commonly used drugs, with each causing changes that may be potentially lethal, can adversely affect the function of the heart. In addition some drugs have synergistic effects that can also damage cardiovascular tissues. The drug-related cardiotoxic effects of antineoplastic agents, psychotropic medications, heavy metals, substances of abuse, promotility agents, antihistamines, antimicrobials and antiarrhythmic agents are discussed. Hypersensitivity myocarditis is also discussed.

Cardiac sarcoidosis: Recurrent disease in a heart transplant patient following pulmonary tuberculosis infection

Cardiac transplantation is indicated for patients with end-stage cardiomyopathy secondary to cardiac sarcoidosis. Although rare, recurrent disease has been reported in two cases. The current report presents a case of recurrent cardiac sarcoidosis in a patient 45 months postorthotopic heart transplantation and 40 months following reactivation of latent Mycobacterium tuberculosis infection. The patient was the first to have recurrent disease following an infection that has been proposed to be involved in its pathogenesis. The patients interval between transplant and recurrence is the longest reported to date.

Complications of Bioglue postsurgery for aortic dissections and aortic valve replacement

Aims Bioglue is an adhesive used during cardiovascular surgery to improve hemostasis perioperatively and to strengthen and reinforce vascular anastomoses. It has also been used to ‘seal’ the false lumen in patients presenting with acute aortic dissections. Herein, we examine the complications of Bioglue, which may lead to redo sternotomy in selected patients. Methods A review of pathology records at our institution from 2002 to 2010 found 4 cases of excised aortic tissue and/or aortic valves with previous Bioglue® use at initial operation. Excised tissues and valves were examined, looking for the presence of Bioglue®, inflammatory cells (acute, chronic, macrophage and giant cells) and micro-organisms. Patient demographics were also reviewed and recorded. Results We identified four cases of Bioglue use found at redo surgery, after the formation of pseudoaneurysm (n=3) and aortic stenosis (n=1). Mean interval to redo surgery was 2.28 + 0.32 years (range 2-2.6 years). Pseudoaneurysm formation was thought to be caused by an inflammatory reaction to the Bioglue® itself in two cases, while one case found no such reaction. One patient with previous aortic valve replacement had large annular abscesses filled with necrotic debris surrounding the prosthesis and pannus found on the sewing cuff, comprised of Bioglue® itself. Conclusions The mechanisms leading to these complications include mechanical strain, inflammation and tissue necrosis. The judicious use of Bioglue® when clinically indicated, and close follow-up of these patients with serial imaging, remain an integral part of avoiding future complications.

Pathologic Evaluation of 28 Mitroflow Pericardial Valves: A 12-Year Experience

BACKGROUND Mitroflow pericardial valves (model A12) are used for aortic valve replacement with favorable hemodynamic results, and are ideal for patients with a small aortic annulus as the pericardium is mounted outside the stent frame. We report the morphologic findings in explanted Mitroflow valves from our institution and demonstrate pathologic changes leading to explantation. METHODS From 2001 to 2013, 28 Mitroflow valves were analyzed at our institution. Demographic data was recorded. The excised valves were analyzed by gross and microscopic examination. After pathologic examination, mode of failure was determined. RESULTS During the 12-year period, 28 valves were explanted. The 28 patients, with a mean age at implant of 72.2 ± 5.7 years (range, 60 to 81 years), included 16 males (57%). The mean interval between index surgery and explantation was 4.5 ± 3.4 years (range, 3 months to 11 years). Structural valve deterioration was seen in 18 (64%) patients; mean age at implantation was 72.1 ± 5.69 years with an implant duration of 6.25 ± 2.6 years. Findings in patients with structural valve deterioration included cusp thickening (n = 18), tears (n = 17), pannus deposition (n = 17), and calcification (n = 14). Nonstructural valve deterioration and endocarditis was seen in 1 (4%) and 7 patients (25%), respectively. One valve explanted at post mortem did not contribute to the patients death. CONCLUSIONS Structural valve deterioration was seen in 18 of 19 explanted valves with implant durations of at least 30 months, and is related to valve design. It appears that clinicians should carefully consider Mitroflow valve implantation in all patients, even in patients older than 65 years old, given the early presence of structural valve deterioration.

Giant cell aortitis: a difficult diagnosis assessing risk for the development of aneurysms and dissections

A significant location affected by giant cell (GC) arteritis is the ascending aorta, where aneurysms may develop and catastrophic ruptures and acute dissections can occur. Herein, we discuss three cases of GC aortitis discovered at pathological examination of surgically excised aortic aneurysmal tissue. There was no clinical suspicion of any underlying inflammatory process. We describe the main clinical features of the patients in conjunction with a review of the literature to identify any common clinical presentations that manifest in these patients. Giant cell aortitis in the absence of previously established GC arteritis is difficult to identify, and a careful analysis of the history and presentation along with appropriate investigations (e.g., erythrocyte sedimentation rate) may prompt the clinician to consider GC aortitis and suggest immunosuppressant therapy.

Recurrent cardiac amyloidosis following previous heart transplantation

Recurrent cardiac amyloidosis has been reported in the literature. We present two cases, one at 41 months after heart transplant and autologous stem cell transplant, and the other, at 83 months following heart transplantation. The former is the first case ever reported of a patient with amyloid light chain amyloidosis with systemic recurrence following these two treatment modalities, and the latter is a patient with hereditary amyloidosis, whose interval to disease recurrence is the longest ever reported for this type.

Bilateral rectus sheath hematomas in a coughing patient.

Funding: None. Conflict of Interest: MM receives consultancy funds and grants from: Eli Lilly Canada, Astra Zeneca, Merck Canada, and Pfizer Inc. The other authors have nothing to disclose. Authorship: All authors had access to data and a role in manuscript preparation. Requests for reprints should be addressed to Lorraine Jensen, MD, Department of Medicine, University of Toronto, Suite RFE 3-805, 200 Elizabeth Street, Toronto, ON M5G 2C4, Canada. E-mail address: lorraine.jensen@mail.utoronto.ca

Bilateral congenitally bicuspid aortic and pulmonic valves: a rare entity

We present a case of a 70-year-old man who presented to hospital with autoimmune hemolytic anemia, who was found, incidentally, at postmortem, to have bilateral bicuspid aortic and pulmonic valves.

Incidental finding of cor triatriatum sinister in an adult post-myocardial infarction.

We report a case of a 51-year-old man who was transferred from a community hospital to our institution in cardiogenic shock after thrombolytic therapy for myocardial infarction. At autopsy, a cor triatriatum sinister was found. This may have contributed to his poor outcome post infarction.