Atrial masses post cardiac transplantation: diagnostic and treatment dilemmas.

Atrial masses postcardiac transplant are not well reported and their diagnosis and treatment can be challenging. In the asymptomatic patient, differentiating thrombus from cardiac tumor can sometimes be difficult and the use of multiple imaging modalities is recommended. Accurate diagnosis is imperative to inform a treatment plan that balances the benefits and risks of a medical versus surgical approach. We present three cases of atrial masses postcardiac transplant to illustrate this clinical dilemma.

SARS-coronavirus modulation of myocardial ACE2 expression and inflammation in patients with SARS.

BACKGROUND: Angiotensin converting enzyme 2 (ACE2), a monocarboxylase that degrades angiotensin II to angiotensin 1-7, is also the functional receptor for severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) and is highly expressed in the lungs and heart. Patients with SARS also suffered from cardiac disease including arrhythmias, sudden cardiac death, and systolic and diastolic dysfunction. MATERIALS AND METHODS: We studied mice infected with the human strain of the SARS-CoV and encephalomyocarditis virus and examined ACE2 mRNA and protein expression. Autopsy heart samples from patients who succumbed to the SARS crisis in Toronto (Canada) were used to investigate the impact of SARS on myocardial structure, inflammation and ACE2 protein expression. RESULTS: Pulmonary infection with the human SARS-CoV in mice led to an ACE2-dependent myocardial infection with a marked decrease in ACE2 expression confirming a critical role of ACE2 in mediating SARS-CoV infection in the heart. The SARS-CoV viral RNA was detected in 35% (7/20) of autopsied human heart samples obtained from patients who succumbed to the SARS crisis during the Toronto SARS outbreak. Macrophage-specific staining showed a marked increase in macrophage infiltration with evidence of myocardial damage in patients who had SARS-CoV in their hearts. The presence of SARS-CoV in the heart was also associated with marked reductions in ACE2 protein expression. CONCLUSIONS: Our data show that SARS-CoV can mediate myocardial inflammation and damage associated with down-regulation of myocardial ACE2 system, which may be responsible for the myocardial dysfunction and adverse cardiac outcomes in patients with SARS.

Verapamil ameliorates the clinical and pathological course of murine myocarditis.

The effects of the calcium channel blocking agent, verapamil, were studied in a murine model of viral myocarditis. Three groups of 8-wk-old DBA/2 mice (n = 25 each) were inoculated with 10 plaque-forming units of encephalomyocarditis virus and randomized to three treatment regimens. Group 1 mice received verapamil intraperitoneally (5 mg/kg per d) for 7 d before infection, followed by verapamil orally (mean dose of 3.5 mg/mouse per d) in drinking water during infection. Group 2 mice received only verapamil orally starting on day 4 after infection, coincident with peak viremia. Group 3 (infected control) received no verapamil in regular drinking water after viral inoculation. Additional control animals were studied in group 4 (n = 21), consisting of uninfected control animals receiving intraperitoneal and oral verapamil at doses identical to group 1, and in group 5 (n = 21), consisting of uninfected and untreated controls. Animals were randomly killed from each group (n = 7) at 7, 14, and 28 d after infection. Routine histology was performed blindly on an apical slice of each heart and semi-quantitatively graded for inflammation, necrosis, calcification, and fibrosis on a scale of 0-4. Digital planimetry was performed to measure the absolute and relative areas of inflammation and necrosis. The pretreated animals in group 1 showed marked reduction in inflammation and necrosis (score of 3.7 +/- 1.4 vs. 8.7 +/- 2.0 in group 3 on day 14, P < 0.05) and were indistinguishable from the posttreated group 2 mice (score of 4.0 +/- 1.5 vs. 8.7 +/- 2.0 in group 3 on day 14, P < 0.05). All the uninfected control animals (groups 4 and 5) showed no myocardial lesions whether treated with verapamil or not. Quantitative planimetry confirmed decreased inflammation and necrosis (2.0 +/- 3.3% in group 1 and 3.5 +/- 3.1% in group 2 vs. 21.9 +/- 22.6% in group 3 on day 14). Untreated infected hearts injected with liquid silicone rubber exhibited extensive areas of focal microvascular constriction and microaneurysm formation; verapamil treatment in either group 1 or 2 completely abolished these abnormalities, resembling uninfected controls in groups 4 or 5. We conclude that verapamil, whether given before infection or after peak viremia in an encephalomyocarditis model of murine myocarditis, significantly reduces the microvascular changes and myocardial necrosis, fibrosis, and calcification leading to cardiomyopathy. This suggests the potentially important role of calcium and microvascular spasm in the pathogenesis of viral myocarditis leading to dilated cardiomyopathy, and may have future therapeutic implications.

Favorable left ventricular remodeling following large myocardial infarction by exercise training. Effect on ventricular morphology and gene expression.

Continued adverse remodeling of myocardium after infarction may lead to progressive ventricular dilation and heart failure. We tested the hypothesis that exercise training in a healed myocardial infarction-dysfunction rat model can favorably modify the adverse effects of ventricular remodeling including attenuation of abnormal myosin gene expression. Sprague-Dawley rats were subjected to either proximal LAD ligation or sham operation. At 5 wk after the operation, animals were randomly assigned to sedentary conditions or 6 wk of graduated swim training, creating four experimental groups: infarct sedentary (IS), infarct exercise (IE), sham sedentary (SS), and sham exercise (SE). At 11 wk all rats were sacrificed and analyzed. Compared to sedentary infarct controls, exercise training attenuated left ventricular (LV) dilation and allowed more hypertrophy of the non infarct wall. The exercise-trained hearts also showed a reduction in the estimated peak wall tension. Northern blot analysis showed an increase in beta-myosin heavy chain expression in the hearts of the sedentary infarction group soon after infarction when compared to sham controls. However, with exercise training, there was a significant attenuation of the beta-myosin heavy chain expression in the myocardium. Exercise training in a model of left ventricular dysfunction after healed myocardial infarction can improve the adverse remodeling process by attenuating ventricular dilation and reducing wall tension. The abnormal beta-myosin expression was also attenuated in the exercise trained group. This is evidence that abnormal gene expression following severe myocardial infarction dysfunction can be favorably modified by an intervention.

Inhibition of norepinephrine-induced cardiac hypertrophy in s100beta transgenic mice.

We have recently reported that the Ca2+-binding protein S100beta was induced in rat heart after infarction and forced expression of S100beta in neonatal rat cardiac myocyte cultures inhibited alpha1-adrenergic induction of beta myosin heavy chain (MHC) and skeletal alpha-actin (skACT). We now extend this work by showing that S100beta is induced in hearts of human subjects after myocardial infarction. Furthermore, to determine whether overexpression of S100beta was sufficient to inhibit in vivo hypertrophy, transgenic mice containing multiple copies of the human gene under the control of its own promoter, and CD1 control mice were treated with norepinephrine (NE) (1.5 mg/kg) or vehicle, intraperitoneally twice daily for 15 d. In CD1, NE produced an increase in left ventricular/body weight ratio, ventricular wall thickness, induction of skACT, atrial natriuretic factor, betaMHC, and downregulation of alphaMHC. In transgenic mice, NE induced S100beta transgene mRNA and protein, but provoked neither hypertrophy nor regulated cardiac-specific gene expression. NE induced hypertrophy in cultured CD1 but not S100beta transgenic myocytes, confirming that the effects of S100beta on cardiac mass reflected myocyte-specific responses. These transgenic studies complement in vitro data and support the hypothesis that S100beta acts as an intrinsic negative regulator of the myocardial hypertrophic response.

An approach to endomyocardial biopsy interpretation.

The endomyocardial biopsy (EMB) remains the gold standard mode of investigation for diagnosing many primary and secondary cardiac conditions. Through a percutaneous and transvenous route, tissue fragments are generally procured from the right ventricular septum, with very few complications. Widespread use of EMB followed the development of heart transplantation as a means to follow allograft rejection. It has since been useful in helping to diagnose conditions affecting the heart, including cardiomyopathies, myocarditis, infiltrative lesions, arrhythmias, and drug toxicities. The procedure has also been used as a research tool to investigate the natural history of disease and the cardiotoxicity of new medications. This review presents an approach to the evaluation of the EMB, which is particularly directed towards those who may be asked to interpret such biopsies, but are not dedicated cardiovascular pathologists. Through a systematic evaluation of the endocardium, myocardium, interstitium, and intramural vessels, in the context of a complete clinical history, enough information can be deduced to diagnose or exclude specific conditions of clinical value.

Systemic cobalt toxicity from total hip arthroplasties: review of a rare condition Part 1 - history, mechanism, measurements, and pathophysiology.

UNLABELLED: Recently, the use of metal-on-metal articulations in total hip arthroplasty (THA) has led to an increase in adverse events owing to local soft-tissue reactions from metal ions and wear debris. While the majority of these implants perform well, it has been increasingly recognised that a small proportion of patients may develop complications secondary to systemic cobalt toxicity when these implants fail. However, distinguishing true toxicity from benign elevations in cobalt ion levels can be challenging. The purpose of this two part series is to review the use of cobalt alloys in THA and to highlight the following related topics of interest: mechanisms of cobalt ion release and their measurement, definitions of pathological cobalt ion levels, and the pathophysiology, risk factors and treatment of cobalt toxicity. Historically, these metal-on-metal arthroplasties are composed of a chromium-cobalt articulation. The release of cobalt is due to the mechanical and oxidative stresses placed on the prosthetic joint. It exerts its pathological effects through direct cellular toxicity. This manuscript will highlight the pathophysiology of cobalt toxicity in patients with metal-on-metal hip arthroplasties. TAKE HOME MESSAGE: Patients with new or evolving hip symptoms with a prior history of THA warrant orthopaedic surgical evaluation. Increased awareness of the range of systemic symptoms associated with cobalt toxicity, coupled with prompt orthopaedic intervention, may forestall the development of further complications.

Systemic cobalt toxicity from total hip arthroplasties: review of a rare condition Part 2. measurement, risk factors, and step-wise approach to treatment.

UNLABELLED: As adverse events related to metal on metal hip arthroplasty have been better understood, there has been increased interest in toxicity related to the high circulating levels of cobalt ions. However, distinguishing true toxicity from benign elevations in cobalt levels can be challenging. The purpose of this review is to examine the use of cobalt alloys in total hip arthroplasty, to review the methods of measuring circulating cobalt levels, to define a level of cobalt which is considered pathological and to review the pathophysiology, risk factors and treatment of cobalt toxicity. To the best of our knowledge, there are 18 published cases where cobalt metal ion toxicity has been attributed to the use of cobalt-chromium alloys in hip arthroplasty. Of these cases, the great majority reported systemic toxic reactions at serum cobalt levels more than 100 µg/L. This review highlights some of the clinical features of cobalt toxicity, with the goal that early awareness may decrease the risk factors for the development of cobalt toxicity and/or reduce its severity. TAKE HOME MESSAGE: Severe adverse events can arise from the release of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic surgeons should not only be aware of the presenting problems, but also have the knowledge to treat appropriately.

Endocardial photoablation by excimer laser.

A xenon-chlorine excimer laser was used to irradiate normal endocardium of fresh sheep and pig hearts as well as unfixed human endocardial scar. Forty pulses of 370 J and 35 ns each resulted in penetration of up to 12 mm in normal tissue and only 3.5 mm in scarred endocardium. Dosimetry indicated that the volume of vaporized scarred tissue was 1/10th that of normal endocardium (0.19 to 0.40 versus 1.35 to 3.22 mm3/J). Ultrastructurally, there was a sharp demarcation of only 10 mu between the region of injury and normal myocardium, with little evidence of heat injury. The high power and short duration of these lasers coupled with the lack of a boundary zone of injury suggest that excimers may be an ideal tool for arrhythmia ablation.

Pathologic fibrosis and matrix connective tissue in the subaortic myocardium of patients with hypertrophic cardiomyopathy.

To evaluate scar-type and matrix connective tissue and to assess their role in the diastolic dysfunction of hypertrophic cardiomyopathy, surgically resected subaortic myectomy specimens and several autopsy hearts from patients with hypertrophic cardiomyopathy were studied. Eighteen specimens were differentially stained by a newly developed method that precisely determines relative collagen content; these tissues were compared with postmortem hypertrophied and normal control subaortic specimens. Quantitation revealed a 72% higher level (36.5 vs. 22.1 micrograms collagen/mg protein) of stainable collagen in the hearts with hypertrophic cardiomyopathy than in hypertrophied control hearts. The endocardial plaque was quantitated morphometrically, and it constituted only 4.6 +/- 1.7% of the total increased collagen content in the cardiomyopathy specimens. For the matrix studies, the cardiomyopathy specimens were stained by a silver impregnation technique that identifies connective tissue elements not normally visible with routine histologic methods. There was a marked increase in content of all matrix components, both in areas of pathologic scarring and in "normal" zones. Whorls of matrix connective tissue were noted in regions of myocyte whorls, as well as independent of them. Thus, these studies revealed a striking increase of both scar-type and matrix connective tissue in hypertrophic cardiomyopathy. The extensive scarring and the pronounced interstitial and intercellular matrix connective tissue may contribute to the increased ventricular chamber stiffness and impaired relaxation in this disease.

Abnormalities in intramyocardial arteries detected in cardiac transplant biopsy specimens and lack of correlation with abnormal intracoronary ultrasound or endothelial dysfunction in large epicardial coronary arteries.

OBJECTIVES: We sought to determine whether abnormalities in small intramyocardial vessels could be detected on routine cardiac transplant biopsy specimens and whether these features correlate with intimal thickening by intracoronary ultrasound and endothelial dysfunction in large epicardial vessels. BACKGROUND: Variability in clinical presentation of allograft vasculopathy suggests differential involvement of large and small vessels. Intracoronary ultrasound and endothelial function studies detect large-vessel abnormalities but may not reflect changes in small intramyocardial arteries. The latter could be detected in routine cardiac biopsy specimens by histologic and immunohistochemical studies. METHODS: Thirty-nine cardiac transplant recipients underwent intracoronary ultrasound and acetylcholine studies 5 to 7 days after endomyocardial biopsy. Biopsy tissue was evaluated for coronary artery endothelial plumping and intimal thickening and increased immunostaining for fibronectin, tumor necrosis factor-alpha and receptor for hyaluronan-mediated motility. Large-vessel disease was assessed by calculating an average intimal index from intracoronary ultrasound of the left anterior descending coronary artery. Endothelial function was determined by quantitative coronary analysis after acetylcholine challenge. RESULTS: Coronary arteries were found in the biopsy tissue of 30 (76%) of the 39 patients who formed the study group. Fourteen of 30 patients had abnormal histologic findings. Immunohistochemical analysis for fibronectin, possible in 20 of 30 patients, was positive in 14 (70%) of 20 and correlated with abnormal histologic findings (p = 0.01). Immunostaining was positive for tumor necrosis factor-alpha and receptor for hyaluronan-mediated motility in 12 (40%) and 13 (43%) of 30 patients, respectively. All patients had intimal thickening by intracoronary ultrasound, but intimal index did not correlate significantly with small-artery disease by histologic or immunohistochemical analysis. Large-vessel endothelial dysfunction in 13 patients (43%) did not correlate with either abnormal ultrasound findings or small-vessel disease. CONCLUSIONS: Intramyocardial arteries are readily observed in biopsy specimens from cardiac transplant recipients and provide useful information about allograft vasculopathy. Lack of correlation between intramyocardial and epicardial vessel disease suggests discordant progression of allograft vasculopathy.

Analysis of prosthetic cardiac devices: a guide for the practising pathologist.

Pathologists all over the world increasingly encounter prosthetic cardiac devices. A good evaluation of these devices is a valuable source of information, which can contribute to patient care and the appreciation and understanding of the pathobiology involved in the changes occurring between the host and the implanted prosthetic device. This article summarises the considerations underlying the analysis of prosthetic devices (particularly prosthetic heart valves), including the identification of the devices, the major morphological features of the devices, their modes of failure, and some technical details about evaluation and pitfalls.

Coronary artery stents: identification and evaluation.

First introduced in the 1980s, the coronary stent has been used to reduce the rate of arterial restenosis. Coronary stent implantation is currently a common procedure performed by interventional cardiologists, and the market for development and design is constantly expanding and evolving. This article was designed to assist pathologists in the accurate identification of coronary stents that are currently available, in addition to some that are no longer being implanted. The stents reviewed here were chosen based on frequency of use and/or occurrence in the literature. Some of the newer models have yet to undergo extensive clinical testing. The summaries accompanying each stent include concise physical descriptions and documented complications, intended to serve as a guide for the investigating pathologist.

Myocarditis and myocardial hemorrhage associated with thrombotic thrombocytopenic purpura.

Four patients with thrombotic thrombocytopenic purpura (TTP) developed severe cardiac dysfunction. Endomyocardial biopsy in one patient demonstrated focal myocarditis associated with platelet microthrombi. Cardiac function and TTP improved after plasmapheresis therapy in this as well as in two other patients. A fourth patient died owing to extensive intramyocardial confluent hemorrhages. Cardiac involvement in TTP may be due to microvascular thrombosis, hemorrhage, or myocarditis. Severe myocardial dysfunction may improve with treatment aimed at the underlying hematologic disorder.

Distribution of intimal and medial thickening in the human right coronary artery: a study of 17 RCAs.

OBJECTIVE: To quantify the distribution of intimal and medial thickening in human right coronary arteries (RCAs) obtained at autopsy. BACKGROUND: The shear and tensile stresses created by arterial bifurcation are believed to result in eccentric fibromuscular intimal thickening that leads to atherosclerosis. Vascular curvature has been cited as a cause of atherosclerosis; however, details of the location and extent of intimal and medial thickness in the largely curved human RCA are not adequately documented. METHODS: The right coronary arteries were obtained from 40 postmortem hearts and cut into 20-30 segments, each being 3-4 mm in length. Microscopic sections from the proximal, acute margin, and distal regions of the RCA were digitized around the circumference of the vessel. Seventeen arteries showed insignificant stenosis (<50%) and were selected for detailed examination. RESULTS: Seventy-one percent (12/17) of proximal sections displayed eccentric intimal thickening. Normalized ensemble averaging revealed a preferential thickening on the myocardial side of the artery. At the acute margin region where curvature is most pronounced and at the distal region, 51% (8/17) of the samples showed eccentric thickening, but the ensemble average thickening in these regions showed no preferential location. In these mildly diseased arteries, the thickened intima comprised of mainly smooth muscle cells with an extracellular matrix of collagen and some elastin. A relatively uniform medial smooth muscle layer was seen at all three locations. CONCLUSIONS: The proximal region of the RCA appears to be a site of intrinsic eccentric intimal thickening with maximum thickness on the myocardial side of the artery. Eccentric thickening does occur in the acute margin and distal regions; however, no distinct pattern or location was evident.

Early degradation of collagen after acute myocardial infarction in the rat.

After acute myocardial infarction (MI), proteolysis of necrotic myocardium is mediated by infiltrating inflammatory cells at the infarct margins. Collagen forms a structural fibroskeleton in healthy myocardium, and after MI this collagen may continue to provide significant tensile strength to the necrotic muscle wall. To determine whether collagen is also degraded (which might decrease infarct wall strength) and, if so, whether inflammatory cell proteases are implicated, hydroxyproline was measured from infarct zone and normal zone tissue from 24-hour infarcts produced in control rats and in rats made leukopenic (white blood cell count less than 300/mm3) by prior whole-body irradiation. Hydroxyproline was measured after precipitation of tissue homogenates with trichloroacetic acid to separate partially degraded collagen from larger collagen molecules that might retain structural importance. At 24 hours, there was significant (25%) collagen degradation in the infarct zone (p less than 0.01) in control rats but not in leukopenic rats. Tissue cell counts revealed a paucity of inflammatory cells in the infarct margins in leukopenic rats. Electron microscopic studies revealed greater preservation of collagen in the 24-hour-old infarcts of irradiated leukopenic rats compared with those of control rats. These results suggest that at 24 hours after experimental MI in the rat, there is significant collagen degradation mediated by inflammatory cell proteases.

Effect of ibuprofen on the healing phase of experimental myocardial infarction in the rat.

The healing phase of acute myocardial infarction (AMI) is initiated by proteolysis of necrotic myocardium, followed by infiltration of fibroblasts and deposition of collagen. To assess whether ibuprofen, a potent antiinflammatory agent, preserves existing collagen and enhances deposition of new collagen during infarct healing, biochemical and morphologic studies were made of experimentally induced myocardial infarcts in untreated rats and in rats treated with ibuprofen. All treated rats received 12.5 mg/kg of ibuprofen at 1, 6 and 18 hours after AMI. Group 1 rats underwent measurement of myocardial hydroxyproline (HP) content at 24 hours after AMI. Group 2 rats received ibuprofen, 12.5 mg/kg, twice a day for 2 additional days, with measurement of myocardial HP at 3 days (group 2a) or 21 days (group 2b) after AMI. Group 3 rats received ibuprofen, 12.5 mg/kg, twice a day for 6 additional days with measurement of HP content, or infarct size and degree of thinning at 21 days after AMI. Compared with untreated rats, ibuprofen-treated rats had significantly greater amounts of HP in the infarct at 24 hours (group 1, 8.9 +/- 2.2 nmol/mg dry weight vs untreated, 7.1 +/- 2.8 nmol/mg dry weight, p less than 0.04) and at 21 days (group 2b, 112 +/- 37 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.05, and group 3, 125 +/- 51 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.003). Substantial scar thinning was noted in all rats; no difference in scar thinning was noted between treated and untreated rats at 21 days after AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphology of graft arteriosclerosis in cardiac transplant recipients.

The morphologic features of graft arteriosclerosis (GA) and other vascular lesions were semiquantitatively evaluated. Five failed cardiac allografts attributable to GA and five other allografts were obtained from nine autopsies and one surgical explanation. The subjects, aged 4.5 to 67 years, had a mean allograft survival of 735 +/- 184 days. A total of 1,174 arterial and 754 venous cross-sections were reviewed. Intimal fibrosis (nine cases, 254 arteries, and 118 veins), fibrofatty plaques (eight cases and 35 arteries), and cellular intima thickening and concentric foam cell lesions (eight cases, 326 arteries, and 20 veins) were seen. Cellular lesions contained T lymphocytes, monocytes, and cells of smooth muscle cell origin detected by staining using the immunoperoxidase technique. Allografts with severe GA had a greater luminal stenosis in epicardial arteries (P less than .05), greater cellular proliferation in large mural arterial lesions (P less than .004), and more foam cell lesions in both arteries (P less than .06) and veins (P less than .03) than other allografts. Medical fibrosis and thinning were present in six allografts. Severity of acute rejection (P less than .01) was correlated with the presence of GA. The morphology and distribution of GA is heterogeneous, with evidence supporting an immune-mediated pathogenesis.

Morphologic findings and causes of failure in 24 explanted Ionescu-Shiley low-profile pericardial heart valves.

From 1981 to 1987 just over 608 Ionescu-Shiley low-profile bovine pericardial bioprostheses were implanted at the Toronto Hospital. Twenty-four prostheses (11 aortic and 13 mitral) were surgically explanted from 1988 to 1990 from 20 adults (10 men and 10 women). Prosthesis failure was caused by primary tissue failure in 17 valves or by other mechanisms in seven valves. Variable degrees of tissue failure were also seen in four of the seven valves from the latter group. Primary tissue failure was characterized by fluid insudation between collagen bundles, para stent post tears (alignment stitch related, 20 valves), cusp perforation with prolapse, and calcification. The earliest cusp tears occurred at 28 months. Calcification (10 of 24 cases) was minimal in seven of 10 valves (occurring primarily at the margins of the torn cusp), moderate in two, and severe in one. Tissue overgrowth (pannus) was seen in all but three prostheses. Like its predecessor, the Ionescu-Shiley standard pericardial valve, this prosthesis failed at 2 to 5 years largely due to design-related (alignment stitch) causes and tissue degeneration. Calcification was less prominent, while tissue overgrowth (pannus) was more marked.

The vascular pathology of human hepatic allografts.

Studies of hepatic transplant vasculopathy (TV) have described arterial lesions in selected cases but have not sought to establish the relative prevalence of various arterial and venous lesions. We examined 20 unselected liver allografts and 12 controls to establish the spectrum and distribution of transplant-related arterial and venous lesions. Sections of 1,175 arteries and 936 portal and hepatic veins were reviewed and several histologic parameters were tabulated. Fibrotic (18 cases: 184 arteries and 17 veins) and cellular (10 cases: 353 arteries and 33 veins) lesions were seen. Three allografts had evidence of severe TV with abundant foam cell, myointimal, and mixed fibrocellular lesions in the intima of arteries. These three grafts also had foam cells in portal veins. Allografts with TV had more stenotic arteries (P < .05) and more intimal cellular proliferation (P < .05) compared with non-TV allografts and with controls. Foam cells often demonstrated immunoperoxidase staining for actin, lysozyme, or UCHL-1. Two of the TV cases had marked paucity of bile ducts and required retransplantation.