Virginia M. Walley

Catheter-induced pulmonary artery false aneurysm and rupture: Case report and review

REAS MANY believe that information derived from the pulmonary artery catheter (PAC) is crucial for the diagnosis and quantification of cardiovascular dysfunction, there are those who think it contributes to morbidity and mortality.lJ Persons performing pulmonary artery (PA) catheterization must therefore be cognizant of iatrogenic problems related to the catheter in order to avoid preventable adverse outcomes.3 The most feared complication is perforation of the PA, which is estimated to occur in 0.06% to 0.2% of cases but which carries a mortality rate of 45% to 65%.4,5 Delayed hemorrhage resulting from rupture of catheter-induced pulmonary artery false aneurysms (PAPAs) has been described but reported to be rare.6 A Medline search of virtually all cases reported in the English literature through August 1992 indicates that the high morbidity and mortality associated with this delayed complication have not been fully appreciated. A case is reported of catheter-induced PAPA and rupture and the current knowledge of this complication is reviewed.

Tissue fragments recovered at cardiac surgery masquerading as tumoral proliferations : Evidence suggesting iatrogenic or artefactual origin and common occurrence

The entity described in the literature as a “distinctive cardiovascular lesion” resembling histiocytoid hemangioma and more recently referred to as “mesothelial/ monocytic incidental cardiac excrescence” may not be a true proliferative lesion. Rather, it may represent an artefact produced by suctioning of the pericardial cavity during cardiac surgery. This hypothesis was explored by comparing two index cases of cardiac histiocytoid hem-angioma-like lesions (HLLL) to (a) the contents of extracorporeal bypass pump (ECBP) filters in 22 random cardiac surgical cases, and (b) material adherent to mediastinal and pericardial drains in 15 random post-cardiac surgery cases. In 18 of the 22 ECBP filter cases (82%) and two of the 15 postsurgery cases (13%), tissue fragments indistinguishable from the HHLL index cases were identified. These filter and drain fragments had light microscopic, immunohistochemical, and ultrastructural features identical to those of the index cases, as well as to the HHLLs described in the literature. In neither index case, nor in the study patients, were any proliferative lesions identified at surgery. Three study cases subsequently came to autopsy, and no proliferative lesions were found. This and other evidence strongly suggest that these lesions not only are artefactual, but also are a common occurrence. They are likely produced during cardiac surgery by the cardiotomy suction, with compaction of friable mesothelial strips, other tissue debris, and fibrin into tumor-like fragments that may be transported around the operative site on the suction tip.

Comparative results with the St. Jude Medical and Medtronic Hall mechanical valves

This study compared the clinical performance of the St. Jude Medical and Medtronic Hall mechanical valves in isolated aortic or mitral valve replacement. From 1984 to 1993, 349 St. Jude Medical valves (aortic 237, mitral 112) and 465 Medtronic Hall valves (aortic 272, mitral 193) were implanted in 814 patients at the University of Ottawa Heart Institute. The patients had similar preoperative characteristics. The hospital mortality rate for aortic valve replacement was 3.4% with the St. Jude Medical valve and 5.8% with the Medtronic Hall valve (p = 0.26) and the rate for mitral valve replacement was 8.9% with the St. Jude Medical valve and 11.9% with the Medtronic Hall valve (p = 0.54). Actuarial estimates of survival and freedom from complications were calculated. At 5 years the actuarial probability of survival (including hospital deaths) for aortic valve replacement was 86% +/- 3% with the St. Jude Medical valve and 68% +/- 4% with the Medtronic Hall valve (p = 0.0001) and for mitral valve replacement was 75% +/- 7% with the St. Jude Medical valve and 70% +/- 4% with the Medtronic Hall valve (p = 0.54). The most common cause of late death was cardiac failure and no deaths were caused by structural failure. The 5-year probability of freedom from bleeding after aortic valve replacement was 99% +/- 1% with the St. Jude Medical valve and 95% +/- 2% with the Medtronic Hall valve (p = 0.06) and after mitral valve replacement 99% +/- 1% with the St. Jude Medical valve and 97% +/- 2% with the Medtronic Hall valve (p = 0.37). The 5-year probability of freedom from thromboembolism after aortic valve replacement was 88% +/- 4% with the St. Jude Medical valve and 81% +/- 3% with the Medtronic Hall valve (p = 0.08) and after mitral valve replacement was 85% +/- 7% with the St. Jude Medical valve and 77% +/- 5% with the Medtronic Hall valve (p = 0.17). Reoperation was uncommon and there were no cases of structural valve failure. The 5-year actuarial estimate of freedom from reoperation therefore for aortic valve replacement was 99% +/- 1% with the St. Jude Medical valve and 96% +/- 2% with the Medtronic Hall valve (p = 0.09) and for mitral valve replacement was 98% +/- 2% with the St. Jude Medical valve and 95% +/- 3% with the Medtronic Hall valve (p = 0.40).(ABSTRACT TRUNCATED AT 400 WORDS)

Determinants of hospital survival after cardiac transplantation

To identify the preoperative factors that influence hospital survival after transplantation we analyzed our consecutive experience of 183 transplantations in 179 patients over a 10-year period. There were 151 male and 29 female transplant recipients ranging in age from 10 days to 70 years (mean, 48 +/- 1 years). Diagnoses included coronary disease in 110 patients, cardiomyopathy in 55 patients, valvular disease in 6 patients, and congenital heart disease in 9 patients. Seventy-seven had undergone a previous cardiac operation, and 30 patients required preoperative mechanical support. Forty patients received hearts from donors who were 40 years old or older (range, 40 to 62 years). Ischemic time was greater than 240 minutes in 32 cases, and pulmonary vascular resistance was greater than 3 Wood units in 40 patients (range, 3.1 to 10.0 Wood units). Cyclosporine induction was used in 52 patients, whereas 128 recipients received polyclonal antibody prophylaxis. There were 25 hospital deaths. Recipient diagnosis, use of mechanical support, donor age, and the immune suppression protocol were related to hospital survival according to univariate analysis. Using multiple logistic regression, only the method of immune suppression induction and the use of mechanical assists were significant independent determinants of survival. In conclusion, we believe that extended ischemic times and donor age do not adversely affect the early success of transplantation, whereas induction with immune globulin may reduce early mortality. Patients requiring mechanical support before transplantation continue to be a challenge.

Pulsed excimer laser angioplasty of human cadaveric arteries

Laser angioplasty has been limited by the lack of precise control of thermal and acoustic vascular injury. Pulsed excimer lasers, by contrast, have a capacity to affect target tissue without heat dispersion or damage to surrounding structures. The ablative properties of three excimer wavelengths, krypton fluoride (249 nm), xenon chloride (308 nm), and xenon fluoride (351 nm), were investigated with the use of fresh human cadaveric normal and atherosclerotic femoral arteries. Light and electron microscopy demonstrated clean cuts with histologically normal edges. There was no evidence of either thermal or acoustic damage with any of the wavelengths studied. The depth of ablation varied directly with the number of pulses and inversely with tissue density while the incision width remained constant. The excimer laser appears to offer significant advantages over its conventional counterparts for the ablation of atherosclerotic plaque.

Amyloid and the cardiovascular system: A review of pathogenesis and pathology with clinical correlations☆

The process of amyloidogenesis may complicate diverse disease states. It may be systemic and have serious clinical sequelae; in other circumstances, it is a localized phenomenon and functionally insignificant. In many cases its manifestations may be predictable, with knowledge of the responsible protein. Perhaps no organ system better exemplifies this than the cardiovascular one in which amyloid may form from precursor proteins as varied as immunoglobulin light chains, serum amyloid-A protein, transthyretin and its variants, atrial natriuretic factor, β2-microglobulin, and others. This review describes the state of knowledge in relation to cardiovascular amyloidosis, with particular emphasis on what is currently known about the pathogenesis of the process and the related pathology of the various anatomic components of the cardiovascular system.

Cardiac Transplantation After Mechanical Circulatory Support: A Canadian Perspective

BACKGROUND To assess the relative efficacy of cardiac transplantation after mechanical circulatory support with a variety of support systems, we analyzed our consecutive series of patients who had and did not have mechanical support before transplantation. METHODS A review of 209 patients undergoing cardiac transplantation from 1984 to May 1995 was performed. Group 1 consisted of 110 patients who were maintained on oral medications while awaiting transplantation, and group 2 consisted of 60 patients who required intravenous inotropic support. Group 3 included 39 patients who had transplantation after mechanical circulatory support for cardiogenic shock. The indication for device implantation was acute onset of cardiogenic shock in 38 patients and deterioration while awaiting transplantation in 1 patient. The support systems were an intraaortic balloon pump in 13 (subgroup 3A), a ventricular assist device in 7 (subgroup 3B), and a total artificial heart in 19 patients (subgroup 3C). RESULTS After transplantation, infection was more common in group 3 (56%) than in group 1 (28%) or group 2 (32%) (p = 0.005). Survival to discharge was lower for group 3 (71.7%) than for group 1 (90.9%) or 2 (88.3%) (p = 0.009). For mechanically supported patients, survival to discharge was 84.6% in subgroup 3A, 71.4% in subgroup 3B, and 63.1% in subgroup 3C (p = not significant). CONCLUSIONS Transplantation after mechanical support offers acceptable results in this group of patients for whom the only alternative is certain death. Patient selection and perioperative management remain the challenge to improving these results.

Long-term experience with the ionescu-shiley pericardial valve**

To determine the long-term durability of the Ionescu-Shiley valve, we analyzed our experience with this valve at the University of Ottawa Heart Institute. To 1988, 780 patients have had aortic valve replacement (AVR = 528) or mitral valve replacement (MVR = 252). Of the aortic valves, 310 were standard profile and 218 were low profile. Of the mitral valves, 143 were standard profile and 109 were low profile. Actuarial survival at 10 years was as follows: AVR, 62% +/- 3%; MVR, 58% +/- 4%; p = 0.42. At 14 years, the results were AVR, 44% +/- 1% and MVR, 46% +/- 5%; p = 0.40. Reoperation was required in 197 patients. Structural failure was present in 85% of these valves, with leaflet tears alone in 69%, tears with calcification in 21%, and calcification alone in 10%. Leaflet tears occurred in 95% after AVR and in 78% after MVR (p = 0.006) and were seen in 95% of low-profile valves and 87% of standard-profile valves (p = 0.16). The actuarial freedom from reoperation at 10 years was: AVR, 58% +/- 3%; MVR, 62% +/- 5%; p = 0.49. At 13 years, these rates were 38% +/- 4% for AVR and 25% +/- 9% for MVR (p = 0.79). For AVR, the 10-year rate of freedom from reoperation was 57% +/- 4% for standard-profile valves and 57% +/- 8% for low-profile valves (p = 1.0). Similarly for MVR, the 10-year freedom from reoperation was 61% +/- 6% for standard-profile valves and 68% +/- 8% for low-profile valves.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of porcine valves prepared by dye-mediated photooxidation

BACKGROUND Previous studies demonstrated that dye-mediated photooxidation can stabilize bovine pericardium. Here, photooxidized porcine valve cusp and root tissue were assessed in comparison to fresh and glutaraldehyde-treated samples. METHODS AND RESULTS In an in vitro tissue solubility test, both photooxidized and glutaraldehyde-treated tissues were resistant to protein extraction compared to fresh tissue. A rat subcutaneous model was used to test in vivo stability and calcification potential. In this study, four of the six fresh leaflets were not visible because of resorption while both photooxidized and glutaraldehyde-treated tissues were biostable. Mineral contents of the rat explants were much lower for both fresh and photooxidized leaflets when compared with glutaraldehyde-treated leaflets. Also, the aortic root calcified whether treated or not with the most mineral being associated with glutaraldehyde-treated root. Analysis of photooxidized porcine valves explanted from the mitral position in sheep indicated a material that was biostable and contained only minor calcification, perhaps due to deformed stents. CONCLUSIONS Porcine valve tissue treated by dye-mediated photooxidation is biostable and resistant to calcification, and has potential for use in heart valve bioprostheses.

Arterial expression of the plasminogen activator system early after cardiac transplantation

OBJECTIVES Recent studies suggest that alterations in tissue thrombolysis as well as the inward migration of cells may be specific events that contribute to coronary artery narrowing after cardiac transplantation. Plasminogen activators and inhibitors play a central role in governing not only tissue thrombolysis, but also vascular cell migration. The purpose of this study was to examine arterial wall expression of the plasminogen activation system in coronary arteries during graft vascular disease initiation and progression. METHODS Using in situ hybridization and immunocytochemistry, the expression patterns of uPA and PAI-1 in coronary arteries from cardiac allografts were compared to those of young individuals without disease. RESULTS Both PAI-1 and uPA were over-expressed early after transplantation and as late as 27 months post grafting. Over-expression of these molecules preceded morphological evidence of graft vascular disease. Of special note was the adventitial expression of uPA and PAI-1 in microvessels and myofibroblasts. In contrast, the expression of uPA and PAI-1 in normal coronary arteries was confined to endothelial cells of the central lumen, as well as low levels of expression in intimal and medial smooth muscle cells. CONCLUSIONS Despite morphologic similarities between normal and transplant coronary arteries, differences were noted in the vascular expression pattern of uPA and PAI-1. The exact role of these molecules in graft vascular disease requires further study; however, it is intriguing to consider that a local imbalance in the plasminogen system may contribute to arterial wall thrombosis and/or excessive cell migration and the genesis of complex vascular lesions.