Shuji Fukunaga

Obstruction of st jude medical valves in the aortic position: histology and immunohistochemistry of pannus

OBJECTIVE This study aims to reveal the morphological, histological, and immunohistochemical mechanism of pannus formation using resected pannus tissue from patients with prosthetic valve dysfunction. METHOD Eleven patients with prosthetic valve (St Jude Medical valve) dysfunction in the aortic position who underwent reoperation were studied. We used specimens of resected pannus for histological staining (hematoxylin and eosin, Grocotts, azan, elastica van Gieson) and immunohistochemical staining (transforming growth factor-beta, transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, epithelial membrane antigen, CD34, factor VIII, CD68KP1, matrix metalloproteinase-1, matrix metalloproteinase-3, and matrix metalloproteinase-9). RESULTS Pannus without thrombus was observed at the periannulus of the left ventricular septal side; it extended into the pivot guard, interfering with the movement of the straight edge of the leaflet. The histological staining demonstrated that the specimens were mainly constituted with collagen and elastic fibrous tissue accompanied by endothelial cells, chronic inflammatory cells infiltration, and myofibroblasts. The immunohistochemical findings showed significant expression of transforming growth factor-beta, transforming growth factor-beta receptor 1, CD34, and factor VIII in the endothelial cells of the lumen layer; strong transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, and epithelial membrane antigen in the myofibroblasts of the media layer; and transforming growth factor-beta, transforming growth factor-beta receptor 1, and CD68KP1 in macrophages of the stump lesion. CONCLUSIONS Pannus appeared to originate in the neointima in the periannulus of the left ventricular septum. The structure of the pannus consisted of myofibroblasts and an extracellular matrix such as collagen fiber. The pannus formation after prosthetic valve replacement may be associated with a process of periannular tissue healing via the expression of transforming growth factor-beta.

Usefulness of a multidetector-row computed tomography scanner for detecting pannus formation

BACKGROUND Prosthetic valve dysfunction (PVD) as a result of pannus or thrombus formation is an infrequent but serious complication. Currently available diagnostic tools, however, are insufficient to detect a minute pannus and thrombi. The use of a more advanced diagnostic image, multidetector-row computed tomography scanner, may enable us to determine the anatomic and functional causes of PVD. METHODS Patients who underwent aortic valve replacement with a St. Jude Medical valve were examined by transthoracic echocardiography and cineradiography to diagnose PVD. Sixteen patients with PVD (PVD group) and 12 patients with normal prosthetic valve function (control group) were studied using the multidetector-row computed tomography scanner. The multidetector-row computed tomography findings in 2 patients with PVD were validated by the observations during reoperation. RESULTS In 13 of 16 patients (81%) in the PVD group and 3 of 12 patients (25%) in the control group, multidetector-row computed tomography demonstrated that an abnormal small tissue, regarded as pannus, was found to extend from the left ventricular septum into the pivot guard. These findings were confirmed by the observations during reoperation in 2 patients in the PVD group. CONCLUSIONS Multidetector-row computed tomography can be a useful diagnostic technique for anatomic and functional evaluation of PVD as a result of pannus formation.

Tricuspid valve replacement with the St. Jude Medical valve: 19 years of experience

OBJECTIVE The choice of the valve substitute in the tricuspid position remains controversial. A St. Jude Medical valve is a choice of valve substitute and its lower thrombogenicity and excellent hemodynamic performance have been reported even in the tricuspid position. However, little is known of the long-term durability of the St. Jude Medical valve in the tricuspid position. Our long-term experience of tricuspid valve replacement showed the higher thrombogenicity than we had expected, therefore, this study was done to reconsider our strategy for valve choice. METHODS This study reviewed 23 patient who underwent 25 tricuspid valve replacements with the St. Jude Medical valves from 1980 to 1997. The mean age was 40 years. Eleven patients (48%) were men. There were four in-hospital deaths (17%). The remaining 19 patients were all alive and followed from 2.2 to 19.0 years (mean 11.8 years). RESULTS The overall survival, including hospital mortality, was 83%, 10 and 15 years after surgery. Valve thrombosis occurred in six patients. Freedom from valve thrombosis was 78 and 70%, 10 and 15 years after surgery, respectively. The linearized rate of the valve thrombosis was 2.9%/patient-years. Six patients required reoperation. The mean interval to reoperation was 9.5 years. Freedom from reoperation was 83% and 75%, 10 and 15 years after surgery, respectively. The linearized rate of the reoperation was 2.8%/patient-years. No structural valve deterioration was found. Echocardiographic study showed that the function of the St. Jude Medical valve without valve-related complications was well maintained. CONCLUSIONS The higher thrombogenicity of the St. Jude Medical valve in the tricuspid position altered our choice of valve substitutes from the St. Jude Medical valve to a bioprosthesis which is lack of need for anticoagulant therapy except for juvenile patients who are able to maintain potent anticoagulant therapy.

Obstruction of mechanical valve prostheses: clinical diagnosis and surgical or nonsurgical treatment.

Twenty patients underwent nonsurgical and/or surgical treatment for obstruction of mechanical prosthetic valves. The obstructed prosthetic valve was in the aortic position in 11 patients, in the mitral position in 5, and in the tricuspid position in 4. Twelve patients had a bileaflet valve (3 aortic, 5 mitral, 4 tricuspid), and 8 had a tilting disk valve (all aortic). The diagnosis of prosthetic valve obstruction was made by cineradiography and echocardiography. Thrombolytic therapy was instituted in a series of our 10 most recent patients (11 cases), except for one patient with acute renal failure, regardless of the position of the obstructed prosthetic valve. Successful thrombolysis was achieved in 6 cases (54.5%). Six patients required surgical treatment subsequent to either failed or incomplete thrombolysis, and one patient died of congestive heart failure 1 month after surgery. Nonfatal neurologic events occurred in 2 cases (18.2%). A total of 16 patients underwent surgical treatment. Two (12.6%) of the 16 patients died of causes unrelated to the operative procedures before discharge from the hospital. These results suggest that thrombolytic therapy appears to be an attractive nonsurgical alternative for valve thrombosis when the patients clinical condition is not critical, and thus surgical treatment should only be performed in an emergency on seriously ill patients.

Long-term results of aortic valve replacement with a small St. Jude medical valve in Japanese patients.

BACKGROUND The use of small aortic valve prostheses is still controversial because of negative effects caused by residual obstruction of the left ventricular outflow tract. This study evaluated the long-term results after aortic valve replacement with a small valve from St. Jude Medical (St. Paul, MN). METHODS Between 1980 and 1999, 221 patients underwent isolated aortic valve replacement with a 23-mm or smaller St. Jude Medical valve. The mortality rate and complications were analyzed, echocardiography was performed, and peak pressure gradient, mean pressure gradient, indexed effective orifice area, and left ventricular mass index were measured. RESULTS The follow-up rate in the 221 patients was 99.5% (maximum length, 24.1 years; mean, 10.3 years). Patients with a 19-mm valve were mainly women, older, and had smaller body surface areas. Freedom from valve-related death at 20 years was 100%, 86.0%, and 90.2% in patients with 19-, 21-, and 23-mm valves, respectively. There were no significant differences in the actuarial freedom from valve-related deaths. Echocardiography showed significantly higher peak (32.3 mm Hg) and mean pressure gradients (17.6 mm Hg) and a smaller indexed effective orifice area (0.70 +/- 0.15 cm(2)/m(2)) in patients with a 19-mm valve than in those with a 21- or 23-mm valve. Moderate prosthesis-patient mismatch was present in most patients with a 19-mm valve according to one definition; however, the improvements in ejection fraction and left ventricular mass index were significant, and functional recovery (mean New York Heart Association class, 1.3 +/- 0.5; mean specific activity scale, 5.1 +/- 0.8 metabolic equivalents) was satisfactory. CONCLUSIONS The present long-term results demonstrate that a small St. Jude Medical valve can be advantageously used in most Japanese patients because their body size is generally smaller than that of Western patients. These findings also emphasize that it is not prosthesis size per se that matters but rather the relation between body size and prosthesis size.

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.

Effect of Surgery for Atrial Fibrillation Associated With Mitral Valve Disease

BACKGROUND The purpose of this study is to evaluate the effect of surgery for atrial fibrillation (AF) associated with mitral valve disease. METHODS From September 1994 to December 2006, 244 patients who underwent mitral valve surgery were enrolled in this study. The maze procedure or pulmonary vein isolation was concomitantly performed in 147 patients, while the remaining 97 patients were not surgically treated for AF. The patients were divided into 3 groups based on their cardiac rhythm at discharge from the hospital: the sinus group (108 patients), the intractable AF group (39 patients), and the untreated AF group (97 patients). The clinical features and late results of patients were compared among these groups. RESULTS Early mortality rate was 0.7% and no major morbid events had occurred. Follow-up was completed in 95.6% of the patients and the mean follow-up period was 6.03 years. Actuarial survival was not significant between the sinus and AF groups. Actuarial freedom from thromboembolism at 5 and 10 years was 96.5% in the sinus group, 82.4% and 78.1%, respectively, in the intractable AF group, and 93.4% and 89.1%, respectively, in the untreated AF group; statistical significance was observed among the 3 groups (p = 0.01). By means of multivariate analysis, intractable AF was found to be the only risk factor for thromboembolism and other complications. CONCLUSIONS Atrial fibrillation associated with mitral valve disease should be treated, because restoration of the sinus rhythm might lead to a lower incidence of thromboembolism and valve-related complications in the later period.

High-dose cimetidine reduces proinflammatory reaction after cardiac surgery with cardiopulmonary bypass

BACKGROUND Cimetidine, which is usually used for gastric ulcer, enhances cellular immunity. The effect of cimetidine on perioperative proinflammatory response after cardiac surgery with cardiopulmonary bypass was investigated. METHODS Elective coronary artery bypass graft cases in which CPB was performed were placed randomly in a cimetidine (C) group (n = 20) or a no-treatment (N) group (n = 20). The time course of plasma levels of neutrophil elastase, interleukin (IL)-6 and IL-8, leukocyte counts, lymphocyte recovery ratio, C-reactive protein, creatine-kinase-MB, and oxygenation index were analyzed. RESULTS The plasma levels of neutrophil elastase and IL-8 were inhibited in the C groups at 2 hours after CPB termination. In a comparison of the two groups, the C group demonstrated higher lymphocyte recovery ratio and lower C-reactive protein on postoperative day 5 and shorter intubation time. No intergroup differences were observed in IL-6, leukocyte counts, creatine-kinase-MB levels, or oxygenation index. CONCLUSIONS Cimetidine may reduce surgical stress and augment the immune system after cardiac surgery with cardiopulmonary bypass.

Left ventricular myxoma: report of a case.

Abstract Although recent advances in echocardiography have made it easier to detect cardiac tumors, left ventricular myxomas are still rare and often not found until the patient presents with a history of syncopal episodes or systemic embolization. Left ventricular myxomas are usually benign and curable; however, unreliable excision of the myxoma due to poor visualization of the left ventricular cavity can result in recurrence. To prevent recurrence, it is necessary to select the most appropriate surgical approach to excise the myxoma completely. We report herein the case of a patient in whom surgical excision of a left ventricular myxoma arising from the posterior wall of the left ventricle was successfully performed.

Recurrent Mitral Regurgitation Due to Calcified Synthetic Chordae

We report a case of recurrent mitral regurgitation due to calcification of the expanded polytetrafluoroethylene sutures. According to pathologic findings, it was believed that due to the dystrophic calcification of the fibrous tissue covering the expanded polytetrafluoroethylene sutures, there was increased hyalinization, leading to sclerosis and shortening of the chordae. Calcification of expanded polytetrafluoroethylene sutures after mitral valve repair is a rare complication; however, careful follow-up should be needed because such change may occur in long-term periods after implantation.