Echocardiographic assessment of aortic valve replacement with stentless porcine xenografts.

Stentless porcine xenografts (SPXs) implanted in the aortic position have potential hemodynamic advantages over traditional valve prostheses because of the lack of a rigid stent. Twenty-four patients (mean age 59 years) who underwent aortic valve replacement with SPXs were studied by echocardiography early after and 26 +/- 10 months (range 8 to 40) after operation. Peak and mean gradients, as well as aortic valve area, did not change significantly from baseline (16.3 +/- 8 and 9.8 +/- 5.6 mm Hg, and 1.78 +/- 0.63 cm2, respectively) to follow-up study (12.5 +/- 5 and 7.7 +/- 3 mm Hg, and 1.8 +/- 0.65 cm2, respectively). At baseline, color flow Doppler imaging showed aortic valve regurgitation where the leaflets coapted centrally in 17 of 24 patients (trivial, n = 14; mild, n = 3). Besides the central leak, paravalvular regurgitation was seen in 4 patients (trivial, n = 3; mild, n = 1). At follow-up, 18 of 24 patients had aortic valve regurgitation (trivial, n = 11; mild, n = 6; and moderate, n = 1). New valvular regurgitation (graded as trivial, n = 2; mild, n = 2; and moderate, n = 1) was detected in 5 patients, and new paravalvular regurgitation (graded as mild) developed in 1 patient. Two patients underwent repeat operation for valve-related complications: (1) rupture of a valve cusp with acute pulmonary edema, and (2) fibrotic stenosis of the left coronary ostium with unstable angina. In conclusion, this study demonstrates good hemodynamic performance of the SPX in the aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

The entrapped balloon: report of a possibly serious complication.

Entrapment of a balloon in the femoral artery at the site of insertion is described. A rupture in the balloon allowed the formation of a clot inside the balloon, which necessitated surgical removal.

Origin of the left pulmonary artery from the aorta: embryologic considerations.

We observed a case of anomalous origin of the left pulmonary artery from the aorta in which the media of the abnormal vessel and the main pulmonary artery were fused, but without communication. This is the fifth isolated case of repair without the use of cardiopulmonary bypass reported in the literature. This pathology should be included in the aortic arch anomalies as a partial or complete failure of development of the left sixth arch.

Selective use of chest tubes in thoracotomies for congenital cardiovascular procedures.

BACKGROUND: Advantages and complications have been reported from the use of chest tubes (CT). To reduce the incidence of complications we have employed a selective use of CT in thoracotomy for congenital cardiovascular procedure; ie, in absence of air leaks and fluid to be drained, no CT was inserted. METHODS: The lung was reexpanded and air evacuated during the chest closure. Early and 6 hours chest roentgenograms were performed on every patient. This study retrospectively reviews the results of this selective approach in 546 patients operated on between 1980 and 1998 mainly for patent ductus arteriosum ligation, pulmonary artery band, aortic coarctation, Blalock-Taussig shunt. Four hundred and eighteen patients did not receive a CT at the initial surgery (group I), and 128 patients received a CT either before or at surgery (group II). RESULTS: 40 patients in group I developed an air or fluid collection large enough to require a CT. Only one patient had complication, from an undetected hemothorax. Nine patients in group II required another CT, and one patient developed a pneumothorax upon pulling out the CT. No death in either group was related to the use or lack of use of the CT. A total of 378 CTs and collecting chambers were saved. CONCLUSIONS: A selective approach to the use of CT in thoracotomies for cardiovascular procedures can be employed with minimal complications, more comfort for the patient, and cost savings.

Tetralogy of Fallot with congenital aortic valvar stenosis: the tetralogy-truncus interrelationship.

Two rare patients are reported with tetralogy of Fallot and congenital aortic valvar stenosis. The anatomic and developmental interrelationship between tetralogy of Fallot and truncus arteriosus is summarized. A study of 100 randomly selected postmortem cases of tetralogy revealed aortic valve pathology in 8%, myxomatous aortic valve leaflets without stenosis in 4%, bicuspid aortic valves without stenosis in 3%, and congenital aortic valvar stenosis in 1%. The frequency of systemic semilunar valve pathology in truncus was much higher (66%): moderate to marked myxomatous change in 44%, mild myxomatous change in 22%, truncal valvar stenosis in 11%, and truncal valvar regurgitation in 15%. Being aware of the tetralogy-truncus interrelationship and knowing that myxomatous aortic valves are prone to premature calcific aortic stenosis and/or regurgitation, physicians should follow the aortic valves of surgically repaired patients with tetralogy of Fallot and truncus arteriosus long term with great care. Timely aortic valvuloplasty or replacement may well prove life-saving in such patients.

Inflammatory pseudotumor of the spleen in a young child.

We describe a case of an inflammatory pseudotumor of the spleen in a 5-year-old boy, found incidentally during a physical examination. The boy underwent a hemisplenectomy. The problems in differentiating this disease from lymphoma of the spleen before surgery and the advantages of hemisplenectomy are discussed. This rare disease has previously been described in the spleen in only 28 cases, the youngest being a 16-year-old patient.

Replacement of the mitral valve in an infant with group B streptococcal endocarditis.

Endocarditis due to group B streptococcus is very rare in infants, and may be associated with significant morbidity and mortality. Review of the literature reveals only a single reported case of an infant with this type of streptococcal endocarditis involving the mitral valve. This infant had underlying congenital heart disease, and died shortly after catheterization. We now report group B streptococcal endocarditis occurring in an infant with a structurally normal heart who was treated successfully by replacement of the mitral valve.

Induction of oxidative stress by homocyst(e)ine impairs endothelial function.

Previous studies have demonstrated a relationship between hyperhomocysteinemia and endothelial dysfunction, reduced bioavailability of nitric oxide, elastinolysis and, vascular muscle cell proliferation. In vivo decreased nitric oxide production is associated with increased matrix metalloproteinase (MMP) activity and formation of nitrotyrosine. To test the hypothesis that homocysteine neutralizes vascular endothelial nitric oxide, activates metalloproteinase, causes elastinolysis and vascular hypertrophy, we isolated aortas from normotensive Wistar rats and cultured them in medium containing homocysteine, and calf serum for 14 days. Homocysteine-mediated impairment of endothelial-dependent vasodilatation was reversed by co-incubation of homocysteine with nicotinamide (an inhibitor of peroxinitrite and nitrotyrosine), suggesting a role of homocysteine in redox-mediating endothelial dysfunction and nitrotyrosine formation. The Western blot analysis, using anti-nitrotyrosine antibody, on aortic tissue homogeneates demonstrated decreased nitrotyrosine in hyperhomocysteinemic vessels treated with nicotinamide. Zymographic analysis revealed increased elastinolytic gelatinase A and B (MMP-2, -9) in homocysteine treated vessels and the treatment with nicotinamide decreases the homocysteine-induced MMP activation. Morphometric analyses revealed significant medial hypertrophic thickening (1.4 +/- 0.2-fold of control, P = 0.03) and elastin disruption in homocysteine-treated vessels as compared to control. To determine whether homocysteine causes endothelial cell injury, cross-sections of aortas were analyzed for caspase activity by incubating with Ac-YVAD-AMC (substrate for apoptotic enzyme, caspase). The endothelium of homocysteine treated vessels, and endothelial cells treated with homocysteine, showed marked labeling for caspase. The length-tension relationship of homocysteine treated aortas was shifted to the left as compared to untreated aortas, indicating reduced vascular elastic compliance in homocysteine-treated vessels. Co-incubation of homocysteine and inhibitors of MMP, tissue inhibitor of metalloproteinase-4 (TIMP-4), and caspase, YVAD-CHO, improved vascular function. The results suggest that alteration in vascular elastin/collagen ratio and activation of MMP-2 are associated with decreased NO production in hyperhomocysteinemia.

Mitral replacement: clinical experience with a ball-valve prosthesis. Twenty-five years later.

The purpose of this report is to review the results of mitral valve replacement since a first report in the Annals of Surgery in 1961, in order to determine the relative importance of new valve designs versus other surgical variables. The continued use of the silastic ball valve in its 1966 configuration (Model 6120), by providing a comparative data base for other new prosthetic valves, allows this analysis. For a valid comparison with the tilting disc (Bjork-Shiley) and the porcine (Hancock and Carpentier-Edwards) valves, only results with the silastic ball valves implanted during comparable time frames should be used. (Formula: see text) Thus, there are no significant differences in the results obtained with the silastic ball valve in time frames comparable to other contemporary valves introduced in the early 1970s. Improved results, therefore, must be non-prosthetic valve related.

Endoscopic retrograde cholangiopancreatography in the treatment of bile leaks and bile duct strictures after laparoscopic cholecystectomy.

We reviewed our experience over 3 years with 11 patients who had bile leaks (Group 1) and 8 patients who had bile duct strictures after laparoscopic cholecystectomy (LC) and were treated with endoscopic retrograde cholangiopancreatography (ERCP) (Group 2). In Group 1, bile leaks were at the level of the cystic duct in 10 patients and from a duct of Luschka in 1 patient; 10 patients had sphincterotomy and 11 patients received barbed stents. All patients had resolution of bile leak and stents were removed after an average of 5 weeks. In Group 2, stenoses were at the level of the common bile duct (CBD) in 7 patients and of the CBD-common hepatic duct in 1 patient. Six patients had a sphincterotomy and 7 patients were successfully treated with pneumatic polyethylene balloon dilatation and stent placement. One patient had unsatisfactory dilatation and was referred to surgery. Two patients had permanent resolution of stenosis at 3 and 4 years of follow-up, 5 patients had recurrence, and a total of 6 patients eventually needed surgery. We conclude that ERCP is effective in resolving isolated bile leaks, but iatrogenic strictures after LC more often require surgical treatment after ERCP.

The role of transesophageal echocardiography in the monitoring of cardiac mass removal: a review of 17 cases.

Intraoperative transesophageal echocardiography (TEE) was used to monitor the removal of intracardiac masses in 17 patients. Prebypass TEE was used to confirm the preoperative diagnosis. It gave a clear image and anatomical definition of the mass in 16 cases. Moreover, in 11 of these patients, prebypass TEE provided information not obtained previously by traditional exams. This information was judged either useful or indispensable for a successful outcome in 10 of these patients. However, in one of the remaining six patients, TEE did not clearly visualize a flat thrombus in the left atrium. Postbypass TEE was used in each case to monitor the surgical results of the mass removal and the associated procedures. In one patient, it disclosed a progressively expanding hematoma in the left atrial wall, which was interfering with mitral valve function. From this experience, we consider intraoperative TEE the best monitoring device during cardiac mass removal because it usually provides a more complete diagnosis and anatomical definition of the mass than the traditional preoperative methods and permits monitoring of the surgical results before chest closure. Some limitations to this method may exist.

Intraoperative echocardiography by a new miniaturized epicardial probe: preliminary findings.

Miniaturized probes constitute recent progress in the field of epicardial echocardiography. We recently used a new miniaturized probe, derived from a standard transesophageal probe, in a series of 12 adult patients who underwent cardiac surgery in order to test the possibility of obtaining new views for epicardial imaging. This study demonstrates the feasibility and safety of performing intraoperative echocardiography when using a miniaturized epicardial probe. This probe may be placed on a broader epicardial and vascular area, thus overcoming the size limitations of the commonly used epicardial probes. The major limitation found with the miniaturized probe, however, was the inability to obtain a true four-chamber view from the ventricular apex, due to the difficulty of holding the probe motionless between the apex and the diaphragm while the heart is beating. Although extensive experience with larger groups of patients and different pathologies will be required to define the full potential of this new probe, the advent of the miniaturized probe may further expand the applicability of epicardial echocardiography in pediatric patients during surgery for congenital heart disease.