Roberto Parravicini

Among available biomaterials, cornea is almost completely devoid of cells and is composed only of collagen fibers oriented in an orderly pattern, which contributes to low antigenicity. Thunnus thynnus, the Atlantic bluefin tuna, is a fish with large eyes that can withstand pressures of approximately 10 MPa. We evaluated the potential of this tuna cornea in cardiac bioimplantation. Eyes from freshly caught Atlantic bluefin tuna were harvested and preserved in a fixative solution. Sterilized samples of corneal stroma were embedded in paraffin and stained with hematoxylin and eosin, and the histologic features were studied. Physical and mechanical resistance tests were performed in comparison with bovine pericardial strips and porcine mitral valves. Corneal material was implanted subcutaneously in 7 rats, to evaluate in vivo calcification rates. Mitral valves made from tuna corneal leaflets were implanted in 9 sheep. We found that the corneal tissue consisted only of parallel collagen fibers without evidence of vascular or neural structures. In tensile strength, the tuna corneal specimens were substantially similar to bovine pericardium. After 23 days, the rat-implanted samples showed no calcium or calcium salt deposition. Hydrodynamic and fatigue testing of valve prototypes yielded acceptable functional and long-term behavioral results. In the sheep, valvular performance was stable during the 180-day follow-up period, with no instrumental sign of calcification at the end of observation. We conclude that low antigenicity and favorable physical properties qualify tuna cornea as a potential material for durable bioimplantation. Further study is warranted.

Acute intermittent porphyria (AIP) is a disorder of the heme biosynthesis pathway of a specific inherited enzymatic defect. Many different environmental factors such as drugs, calorie restriction, infection etc., often play a key role in triggering a porphiric acute attack. We describe a 50‐year‐old woman with AIP who underwent aortic valve replacement due to acute infective endocarditis and review the perioperative management of these patients.(J Card Surg 2012;27:331–334)

Antiphospholipid antibodies are a heterogeneous family of immunoglobulins that includes lupus anticoagulant and anticardiolipin antibodies. They are strongly associated with a clinical syndrome characterized by venous and arterial thrombosis and spontaneous fetal losses. This syndrome may be primary or else secondary to autoimmune or neoplastic diseases. The cardiovascular system is frequently involved with mitral or aortic insufficiency, juvenile myocardial infarction, and primitive pulmonary hypertension. However, the occurrence of intracardiac thrombi is rare. We describe a case of an intracardiac right atrial thrombus in a 19-year-old asymptomatic woman who was admitted in December 1998 to the Thrombosis Center owing to the finding, during routine work-up, of a prolonged activated partial thromboplastin time (71 s) and thrombocytopenia (71 x 1000/mm3), a positive antinuclear antibody test (1/320), positivity for lupus anticoagulant, and increased IgG (92 GPL-U/ml) and IgM (27 MPL-U/ml) anticardiolipin antibodies. Six months later, the patient presented with headache, edema and cyanosis of the face and jugular swelling. Transthoracic and transesophageal echocardiography revealed a right atrial mass which was clearly distinguishable from the tricuspid valve and extended to the superior vena cava. The patient was successfully submitted to surgical excision of the thrombus. Histology revealed that the mass was adherent to an abnormal septum consisting of mesenchymal tissue. Although the American Rheumatology Association criteria for the diagnosis of systemic lupus erythematosus were not fulfilled, the positivity of antinuclear antibody test is in favor of a lupus-like syndrome. The decision to opt for surgical excision of the thrombus was determined by the unclear nature of the atrial mass. It may be necessary that such patients be submitted to anticoagulant therapy for the rest of their lives or temporarily (6-12 months). This underscores the importance of the anatomical abnormality as a promoting factor. Transthoracic echocardiography (as well as transesophageal echocardiography in selected cases) must be considered as an essential component of the initial diagnostic work-up in patients presenting with antiphospholipid antibodies.

The authors report a case of cardiac metastasis of a rectal adenocarcinoma that infiltrated the right ventricle and partially obstructed its outflow tract. Surgical treatment was performed because of syncopal attacks. The differential diagnosis between organized thrombi and intracardiac tumor is considered.

The thickening of the gallbladder wall in patients with ascites is commonly related to hypoalbuminemia and/or portal hypertension. To evaluate the pathogenetic role of these two factors, we correlated gallbladder wall thickness (GBWT) with the albuminemia and the serum–ascites albumin gradient (SAAG), an index of portal hypertension, in 47 patients with ascites caused by cirrhosis of the liver or abdominal malignancy. We found a thickened gallbladder wall in 30/47 patients. The correlation between GBWT and SAAG was 0.64 (n = 47 p < 0.001). No correlation was found between GBWT and albuminemia (r = 0.04). We suggest that the sonographic finding of ascites and gallbladder wall thickening should be considered a valuable sign of transudative ascites and of portal hypertension whatever its cause.

The authors evaluated the diagnostic accuracy of sialic acid and its lipid-bound fraction in ascites and compared these tests with others (fibronectin, cholesterol) recently claimed as valuable in the differential diagnosis of ascites. Fibronectin yielded the best diagnostic accuracy (85%) with no false-positive and 37% of false-negative (10/27). The authors also found higher concentration of sialic acid in malignant ascites than in nonmalignant ascites (P < 0.001) and, taking 300 mg/1 as the cutoff value, the false-positive rate was 10% (four of 40), the false-negative rate 30% (eight of 27), and the overall diagnostic accuracy 82%, comparable to that of the fibronectin. The authors conclude that both fibronectin and sialic acid determinations in ascites may be regarded as accurate markers of neoplastic involvement of the peritoneum, although no test is useful in the ascites with hepatocellular carcinoma and cirrhosis of the liver.

The plasma clearance after oral administration of a completely absorbed drug that is metabolized by the liver depends on its intrinsic clearance. In cirrhosis the bioavailability of a flow-dependent drug increases because of both portosystemic shunting and hepatocyte dysfunction. A drug with a high extraction ratio, lidocaine, and a drug with a low extraction ratio, theophylline, were administered to 27 patients with cirrhosis and 16 control subjects. We found a significant impairment of both theophylline clearance (p < 0.001) and lidocaine clearance (p < 0.001) and an increase in the lidocaine peak concentration (p < 0.001). The three parameters were significantly correlated with each other. The impairment of theophylline metabolism did not correlate with other indexes of disease severity, whereas lidocaine clearance was lower and lidocaine peak level higher in patients with decompensated cirrhosis and evidence of portal hypertension. Thus impairment in lidocaine disposition, which reflects both hepatocyte dysfunction and portosystemic shunting, correlated closer with the severity of liver disease than did theophylline metabolism.