Imaging Surveillance of Hypervascular Liver Lesions in Non-Cirrhotic Patients.

A consensus surveillance protocol is lacking for non-cirrhotic patients with hypervascular liver lesions presumed to represent hepatocellular adenomas. Patients with hypervascular liver lesions <5 cm not meeting criteria for focal nodular hyperplasia or hepatocellular carcinoma underwent surveillance with contrast-enhanced magnetic resonance imaging (MRI) 6, 12, and 24 months after baseline imaging. If lesions remained stable or decreased in size, then surveillance imaging was discontinued. Between 2011 and 2014, 116 patients with hypervascular liver lesions were evaluated. Seventy-nine patients were eligible for the surveillance protocol. Median follow-up was 24 months (range, 1-144 months). One patient (1 %) continued oral contraceptive pill (OCP) use and presented with hemorrhage requiring embolization 5 months after initial diagnosis. Ten patients (13 %) underwent elective embolization or surgical resection for size ≥5 cm. The remaining 68 patients (86 %) continued surveillance without hemorrhage or malignant transformation. Risk factors for requiring intervention during the surveillance period included younger age, larger lesion size, and estrogen use (all p < 0.05). Patients with hepatocellular adenomas <5 cm can safely be observed after discontinuing OCP with serial imaging 6, 12, and 24 months after diagnosis. If lesions remain stable or decrease in size, then longer-term surveillance is unlikely to identify patients at risk for complications.

Large thoracic aortic aneurysm and dissection with rare complication.

Thoracic aortic aneurysms can be found incidentally, however, patients can also present with acute dissection and or rupture that can be fatal. Symptoms that might indicate dissection include chest and back pain as well as lightheadedness. The diagnosis can be made with imaging studies such as computed tomography or magnetic resonance angiogram and sometimes transesophageal echocardiogram. Management is based on the aneurysmal size, location, extension, and the presence of complications. Although smaller localized and slow growing aneurysms can be monitored, larger and or complicated ones may warrant immediate repair. Less-common complications include compression over anatomic structures in the vicinity including vessels and the mediastinum. We report a unique case of a 71-year-old man who presented with a very large thoracic aortic aneurysm with dissection causing compression over the brachiocephalic veins and the mediastinum leading to facial and upper extremity swelling, dysphagia, and cough. This case represents a rare but significant complication of thoracic aortic aneurysm and emphasizes the challenges of its management.

Infrahepatic inferior vena cava agenesis with bilateral renal vein thrombosis.

Congenital anomalies of the inferior vena cava (IVC) are rare and are estimated to be present in 0.07-8.7% of the general population. IVC agenesis (IVCA) is found in approximately 5% of cases of unprovoked lower extremity deep vein thrombosis in patients <30 years of age. Renal vein thrombosis (RVT) is an extremely rare and unusual presentation of IVCA. We report a unique case of a 23-year-old previously healthy man presenting with infrahepatic IVCA-induced bilateral RVT with azygos and hemiazygos continuation. To our knowledge, this is the third reported case in the literature of IVCA-induced RVT and the first to affect the bilateral renal veins in the absence of any other thrombogenic risk factors or any lower extremity venous complications. We also present a literature review of IVCA-induced vein thrombosis and highlight the lack of literature to manage this condition.

Paravalvular leaks around prosthetic valves implanted in the mitral position: technical refinements of the ovine model.

BACKGROUND AND AIM OF THE STUDY: Currently, the sheep model is preferred for preclinical in-vivo evaluation of prosthetic heart valves implanted in the mitral position. In sheep, the anatomy and tissue characteristics in, and around, the native mitral valve's posterior commissure (12:00-3:00 quadrant) makes valve implantation technically challenging. As the majority of non-infectious paravalvular leaks occurred in this quadrant, the surgical technique was modified to offer greater exposure of the annulus in this region and permit more accurate placement of sutures. METHODS: A total of 223 valve implantations (138 bioprostheses, 85 mechanical valves) performed between 1991 and 1998 using the sheep model was retrospectively reviewed. No evidence of endocarditis was found, indicating that etiology of the leaks was due to surgical technique. The incidence of paravalvular leak in the 12:00-3:00 quadrant was compared with that in all other quadrants, both before and after the surgical technique change. RESULTS: The incidence of paravalvular leak was 33% (28/85) for mechanical valves and 13.8% (19/138) for bioprosthetic valves. Leaks in the 12:00-3:00 quadrant accounted for 82% (14/17) of those occurring before the surgery change, and only 43% (13/30) afterwards. Before the change, the incidence of paravalvular leak was 20.3% (14/69) in the 12:00-3:00 position, and 4.3% (3/69) in the non-12:00-3:00 quadrants. After the change, incidence in the 12:00-3:00 position fell to 8.4% (13/154; p < 0.05), but that in other quadrants was not significantly affected. Analysis by valve type showed that leak incidence in the 12:00-3:00 quadrant fell from 20.3% (12/59) to 3.8% (3/79) in the bioprosthesis group (p < 0.05), and from 20.0% (2/10) to 13.3% (10/75) in the mechanical valve group (p = 0.56). In all other quadrants there was no statistically significant change in either groups. CONCLUSION: Technical refinement of surgery has led to a reduced incidence of paravalvular leak in the 12:00-3:00 quadrant, thereby providing a standard by which to compare prostheses implanted in the mitral position. These data should also assist in improving prosthetic heart valve design by enabling device-related complications to be distinguished from model-related complications.