Biomedical subjects

Michael J Reardon

Publications and source records attributed to Michael J Reardon.

At least 19 recordsLinked to original sources

PubMed2006

Coronary pseudoaneurysm: an unreported complication of Castleman's disease.

Castleman's disease is considered a benign disease with very few reports of local invasion into adjacent structures. We present the first reported case of myocardial involvement with Castleman's disease. Careful preoperative planning allowed the placement of a left ventricular assist device with eventual heart transplantation after complete resection of the tumor and unsuccessful myocardial revascularization.

Adrenal Cortex Hormones↗

PubMed2006

Cardiac autotransplantation for primary cardiac tumors.

BACKGROUND: Complete tumor resection is the optimal treatment of cardiac tumors. Anatomic accessibility and proximity to vital structures complicates resection of tumors involving the left heart. The results of standard resection and resection with orthotopic heart transplantation are dismal. We, therefore, reviewed our series of patients with complex left-sided primary cardiac tumors who underwent tumor resection with cardiac autotransplantation. METHODS: Since April 1998, 11 consecutive patients with complex left atrial or left ventricular intracavitary cardiac tumors underwent 12 resections using cardiac autotransplantation-cardiac explantation, ex vivo tumor resection with cardiac reconstruction, and cardiac reimplantation. Demographics, tumor histology, operative data, and mortality were analyzed. Follow-up was complete in all patients. RESULTS: Complete resection by cardiac autotransplantation was used in 7 patients with left atrial sarcoma, 1 patient with left ventricular sarcoma, 2 patients with left atrial paraganglioma, and 1 patient with a complex giant left atrial myxoma. Eight patients had previous resection of their cardiac tumor, and 1 patient had a repeat autotransplantation for recurrent disease. There were no operative deaths. Median overall survival was 18.5 months in patients with sarcomas. All patients with benign tumors are alive without evidence of recurrence. CONCLUSIONS: Cardiac autotransplantation is a feasible technique for resection of complex left-sided cardiac tumors. Recurrent disease after previous resections can be safely treated with this technique. Operative mortality and overall survival seems favorable in this series of patients. Benefits of this technique include improved accessibility and ability to perform a complete tumor resection with reliable cardiac reconstruction.

Adult↗

PubMed2006

Therapy insight: malignant primary cardiac tumors.

Benign cardiac tumors are resected with a high degree of success with modern cardiac surgical techniques. Malignant cardiac tumors, however, continue to pose a therapeutic challenge to cardiac surgeons and oncologists because of the technical difficulty involved in extensive cardiac resections and the aggressive biological nature of the tumors. The majority of malignant cardiac tumors are sarcomas and can be categorized as right heart sarcoma, left heart sarcoma or pulmonary artery sarcoma. Right heart sarcomas are generally angiosarcomas, which infiltrate widely and metastasize early. A combination of chemotherapy and surgical resection is the preferred therapy. Left heart sarcomas, although large, are often less infiltrative and metastasize later than right heart sarcomas, but a similar approach to treatment is usually employed. Surgical resection is more-frequently necessary for left heart sarcomas because of intracardiac blood flow obstruction and congestive heart failure, although the anatomic position and relation of these tumors to cardiac structures can complicate surgery. We have developed and employed the technique of cardiac autotransplantation, which involves cardiac excision, ex vivo tumor resection with cardiac reconstruction, and cardiac reimplantation, to lessen these technical difficulties. Pulmonary artery sarcomas can be treated by radiotherapy, as well as by the other therapies, because the myocardium can be avoided by the radiation fields. Surgical resection of this sarcoma type often requires pneumonectomy and can require pulmonary root replacement.

Antineoplastic Agents↗

PubMed2006

Cardiac autotransplantation for surgical resection of a primary malignant left ventricular tumor.

Primary cardiac sarcomas are rare. In such tumors, surgical resection is sometimes considered necessary to correct obstruction of flow caused by the tumor and to accomplish complete resection. The anatomic difficulties associated with large, primary, intracavitary left-sided sarcomas have led us to use cardiac explantation, ex vivo tumor resection, and cardiac autotransplantation to meet the anatomic challenges of left atrial tumors. We report the case of a patient who had a large, primary, intracavitary, left ventricular sarcoma that was successfully removed by cardiac explantation and ex vivo reconstruction with use of the cardiac autotransplantation technique. This is the 1st report describing the use of cardiac autotransplantation to surgically resect an intracavitary left ventricular malignancy.

Adult↗

PubMed2005

Doppler estimation of left ventricular filling pressures in patients with mitral valve disease.

BACKGROUND: Conventional Doppler measurements have limitations in the prediction of left atrial pressure (LAP) in patients with mitral valve disease (MVD), given the confounding effect of valve area, left ventricular (LV) relaxation, and stiffness. However, the time interval between the onset of early diastolic mitral inflow velocity (E) and annular early diastolic velocity (Ea) by tissue Doppler imaging (TDI), T(E-Ea), which is well related to the time constant of LV relaxation (tau) in canine and clinical studies, is not subject to these variables. We therefore undertook this study to test its usefulness in a patient population. METHODS AND RESULTS: Two-dimensional Doppler and TDI echocardiography were performed simultaneously with right-heart catheterization in 51 consecutive patients (mean+/-SD age, 64+/-11 years) with MVD: 35 with moderately severe to severe mitral regurgitation (MR) and 16 with moderate to severe mitral stenosis (MS). Among several Doppler measurements, only the mitral E/A ratio, isovolumetric relaxation time (IVRT), and pulmonary venous Ar duration had significant relations with mean pulmonary capillary wedge pressure (PCWP). The ratio of IVRT to T(E-Ea) (for MR, r=-0.92; for MS, r=-0.88; both P<0.001) and the ratio of IVRT to tau (for MR, r=-0.74; for MS, r=-0.85; both P<0.001) had the best correlations with PCWP. In 54 repeat studies, including those performed after MV repair or replacement, these ratios tracked well the changes in PCWP and readily identified changes in mean PCWP by > or =5 mm Hg. A similar correlation was noted in 13 patients with atrial fibrillation (r=-0.92, P<0.01) and in a prospective group of 14 patients with MR (r=-0.93, P<0.001). CONCLUSIONS: The ratio of IVRT to T(E-Ea) or to tau can be readily applied for estimating mean PCWP in patients with MVD and can track changes in PCWP after valve surgery.

Aged↗

PubMed2005

Heparin-induced thrombocytopenia associated with bilateral adrenal hemorrhage after coronary artery bypass surgery.

Heparin-induced thrombocytopenia (HIT) is a well-recognized syndrome associated with thrombosis and multiple potential clinical sequelae. We report a case of bilateral adrenal hemorrhage, a known but rare complication of heparin-induced thrombocytopenia complicating a routine coronary artery bypass surgery. Thrombocytopenia, abdominal pain, and signs of adrenal insufficiency in the context of heparin treatment should raise suspicion of this unusual complication.

Adrenal Gland Diseases↗

PubMed2005

Stentless bioprosthetic aortic valve replacement after a homograft root replacement: Toronto SPV implantation after a homograft root.

Stentless bioprosthetic valves for the aortic position offer excellent hemodynamic characteristics, making them an attractive choice ahead of other valve prostheses. We present a unique case in which a patient underwent aortic valve replacement with a stentless porcine valve and mitral valve repair for severe aortic and mitral regurgitation 1 year after a homograft root replacement for acute aortic endocarditis. The rationale for our approach is outlined in the context of current surgical trends.

Animals↗

PubMed2005

Growth of a left atrial sarcoma followed by resection and autotransplantation.

Left atrial sarcomas are among the rarest primary cardiac tumors. This type of tumor has an aggressive behavior and is often resistant to standard approaches to treatment. In this case report we show its rapid growth in vivo and document successful local control with an aggressive surgical approach of ex-vivo resection, reconstruction of the left atrium by a pericardial patch, and subsequent autotransplantation.

Female↗

PubMed2005

Invited commentary.

Explore the source record for details and available documents.

Aortic Dissection↗

PubMed2005

Visceral pericardial hemangioma: unusual location for a rare cardiac tumor.

A 41-year-old man presented with chest pain and a positive electrocardiographic stress treadmill test. Coronary angiography revealed no significant coronary disease, but suggested a mass posterior to the heart. Transthoracic and transesophageal echocardiography revealed a smooth-surfaced mass in the inferoposterior atrioventricular groove, with color Doppler evidence of vascular formation within the mass. Magnetic resonance imaging confirmed the presence of the tumor, without extension into adjacent cardiac chambers or pericardial effusion. At operation, a 4.6- x 3.0-cm tumor attached to the visceral pericardium was excised. Pathologic section resulted in a diagnosis of hemangioma. Hemangiomas account for 2% to 5% of benign cardiac tumors, arising from the cardiac ventricles, atria, valves, and, rarely, the epicardium/pericardium. This case illustrates a very rare location for an unusual benign cardiac tumor. The patient recovered after operation without complication.

Adult↗

PubMed2005

Comparison of antimicrobial impregnation with tunneling of long-term central venous catheters: a randomized controlled trial.

OBJECTIVE: We sought to compare the impact of antimicrobial impregnation to that of tunneling of long-term central venous catheters on the rates of catheter colonization and catheter-related bloodstream infection. SUMMARY BACKGROUND DATA: Tunneling of catheters constitutes a standard of care for preventing infections associated with long-term vascular access. Although antimicrobial coating of short-term central venous catheters has been demonstrated to protect against catheter-related bloodstream infection, the applicability of this preventive approach to long-term vascular access has not been established. METHODS: A prospective, randomized clinical trial in 7 university-affiliated hospitals of adult patients who required a vascular access for > or = 2 weeks. Patients were randomized to receive a silicone central venous catheter that was either impregnated with minocycline and rifampin or tunneled. The occurrence of catheter colonization and catheter-related bloodstream infection was determined. RESULTS: Of a total of 351 inserted catheters, 346 (186 antimicrobial-impregnated and 160 tunneled) were analyzed for catheter-related bloodstream infection. Clinical characteristics were comparable in the 2 study groups, but the antimicrobial-impregnated catheters remained in place for a shorter period of time (mean, 30.2 versus 43.8 days). Antimicrobial-impregnated catheters were as likely to be colonized as tunneled catheters (7.9 versus 6.3 per 1000 catheter-days). Bloodstream infection was 4 times less likely to originate from antimicrobial-impregnated than from tunneled catheters (0.36 versus 1.43 per 1000 catheter-days). CONCLUSIONS: Antimicrobial impregnation of long-term central venous catheters may help obviate the need for tunneling of catheters.

Anti-Bacterial Agents↗

PubMed2004

Loss of C. elegans BBS-7 and BBS-8 protein function results in cilia defects and compromised intraflagellar transport.

Bardet-Biedl syndrome (BBS) is a genetically heterogeneous developmental disorder whose molecular basis is largely unknown. Here, we show that mutations in the Caenorhabditis elegans bbs-7 and bbs-8 genes cause structural and functional defects in cilia. C. elegans BBS proteins localize predominantly at the base of cilia, and like proteins involved in intraflagellar transport (IFT), a process necessary for cilia biogenesis and maintenance, move bidirectionally along the ciliary axoneme. Importantly, we demonstrate that BBS-7 and BBS-8 are required for the normal localization/motility of the IFT proteins OSM-5/Polaris and CHE-11, and to a notably lesser extent, CHE-2. We propose that BBS proteins play important, selective roles in the assembly and/or function of IFT particle components. Our findings also suggest that some of the cardinal and secondary symptoms of BBS, such as obesity, diabetes, cardiomyopathy, and learning defects may result from cilia dysfunction.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Status of mitral valve surgery.

PURPOSE OF REVIEW: To review the evolution of mitral valve repair and outline currently favored repair techniques. RECENT FINDINGS: Chordal replacement with polytetrafluoroethylene sutures is an accepted and reproducible technique for repair of the anterior leaflet. Most posterior leaflet problems can be addressed with either a quadrangular resection or a sliding repair. SUMMARY: Mitral valve surgery has gradually evolved over the period of the last 50 years. Initially, most surgeons replaced the mitral valve in patients with regurgitant disease. It is now known, however, that long-term outcome for patients undergoing repair is superior to that for patients undergoing replacement. Mitral valve repair avoids the complications associated with the artificial valve and anticoagulation. The ability to reproducibly repair the mitral valve requires a detailed knowledge of the disease process and the reparative techniques. This article describes the current approach to mitral valve surgery and the important concepts necessary to achieve a durable repair.

Catheterization↗

PubMed2004

Autotransplantation for central non-small-cell lung cancer in a patient with poor pulmonary function.

Lung resection is the standard therapy for non-small-cell lung cancer confined to the lung. The extent of pulmonary resection is dictated by the location and extent of the tumor and the patient's physiologic ability to tolerate resection. We present the case of a patient who had a large non-small-cell tumor of the lung that involved the right main stem bronchus and the adjacent pulmonary artery; poor pulmonary function precluded a pneumonectomy. Right upper and middle sleeve bilobectomy resection was performed, but reconstruction was not possible due to tethering by the intact lower lobe vein. Therefore, the remaining lower lobe was removed, and the lower lobe vein was divided and reimplanted into the upper lobe pulmonary venous stump. Cephalad advancement and autotransplantation of the lower lobe were then accomplished. These procedures allowed enough mobilization for direct bronchial and arterial reconstruction.

Bronchi↗

PubMed2003

Identification of hibernating myocardium with quantitative intravenous myocardial contrast echocardiography: comparison with dobutamine echocardiography and thallium-201 scintigraphy.

BACKGROUND: There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl(201)) scintigraphy. METHODS AND RESULTS: Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (n=18) and rest-redistribution Tl(201) tomography (n=16) before revascularization. MCE was performed using continuous Optison infusion (12 to 16 cc/h) with intermittent pulse inversion harmonics and incremental triggering (1:1 to 1:8). Myocardial contrast intensity (MCI) replenishment curves were constructed to derive quantitative MCE indices of blood velocity and flow. Recovery of function occurred in 38% of dysfunctional segments. MCE parameters of perfusion in hibernating myocardium were similar to segments with normal function and higher than dysfunctional myocardium without recovery of function (P<0.001). The best MCE parameter for predicting functional recovery was Peak MCIxbeta, an index of myocardial blood flow (area under the curve, 0.83). MCE parameters were higher in segments with contractile reserve and Tl(201) uptake > or =60% (P<0.05) and identified viable segments without contractile reserve by DE. The sensitivity of Peak MCIxbeta >1.5 dB/s for recovery of function was 90% and was similar to Tl(201) scintigraphy (92%) and any contractile reserve (80%); specificity was higher than for Tl(201) and DE (63%, 45%, and 54%, respectively; P<0.05). CONCLUSIONS: MCE with intravenous contrast identifies myocardial hibernation in humans. Prediction of viable myocardium with MCE is best using quantification of myocardial blood flow and provides improved accuracy compared with DE and Tl(201) scintigraphy.

Aged↗

PubMed2003

Surgical outcome in 85 patients with primary cardiac tumors.

BACKGROUND: We present a large, single institution experience with adult cardiac tumors and address factors affecting outcome. METHODS: A retrospective review was made of all patients who underwent surgery for primary cardiac tumors from April 1975 through August 2002. RESULTS: Eighty-five patients (33 male and 52 female) with a mean age of 54 years were identified with follow-up available for 80 (94%) patients. There were 68 (80%) benign tumors and 17 (20%) malignant tumors. Three tumors recurred and were resected giving a total of 88 surgeries. All benign tumors were grossly resected and the extent of resection for malignant disease ranged from 14 (78%) gross resections and 3 (17%) debulkings to 1 (5%) biopsy. There were 4 (5%) early hospital deaths. Median survival was 9.6 months and 322 months for patients with malignant and benign diseases, respectively. Significant predictors of long-term mortality were malignant disease (P <0.0001) and New York Heart Association class (P <0.03). CONCLUSIONS: Surgical resection provides excellent outcome in patients with benign cardiac tumors. Malignant tumors continue to pose a challenge with good local tumor control but limited survival owing to metastatic disease.

Adolescent↗

PubMed2003

A loop technique for the safe, secure, and convenient fixation of subclavian central venous catheters to the chest wall.

Central venous catheters are placed frequently at our institution. Residents are taught the technique of subclavian line placement starting in their first year of training. Frequently the teaching stops once the line is in the vein. We have developed a method of fixation for subclavian central venous catheters that provides a safe, secure, and convenient means of fixation to the chest wall. The central venous catheter can be inserted by that technique with which the physician is the most comfortable and familiar.

Catheterization, Central Venous↗

PubMed2003

Current thinking in stentless valve surgery.

Aortic valve replacement for aortic stenosis represents a tremendous achievement in the management of cardiac disease. However, despite 4 decades of use, the ideal substitute for the diseased aortic valve is still not agreed upon. Stentless aortic valves represent the optimum in hemodynamic performance. This article reviews the current thinking in stentless aortic valve surgery.

Aortic Valve↗