Percutaneous Endovascular Therapeutic Options in Treating Posttransplant Hepatic Artery Thrombosis With the Aim of Salvaging Liver Allografts: Our Experience.

OBJECTIVES: Hepatic artery thrombosis remains a major complication after orthoptic liver transplant. Treatment of hepatic artery thrombosis is complex and requires a multidisciplinary approach. Retransplant is the procedure of choice. In nonsurgical candidates, endovascular options are evolving. MATERIALS AND METHODS: Based on our experience at a busy transplant center, we discuss 4 representative cases to explain the potential role of endovascular treatment beyond just attempts at recanalization. From our experience, as well as a review of the literature, we propose a clinical practice algorithm for optimal treatment of hepatic artery thrombosis after orthoptic liver transplant. RESULTS: The primary traditional endovascular interventional options remain thrombectomy, balloon angioplasty, and use of stents with the aim of revascularization. However, these methods have not proven to be effective. Ultrasonography-assisted thrombolysis, which has thus far been relatively less described in the hepatic vasculature, has the potential of producing the same angiographic results but at lower doses of the thrombolytic agent, thus decreasing the potential for hemorrhagic complications. The adjunctive use of splenic artery embolization and prompt treatment of biliary complications are in our opinion useful in "buying time" to allow adequate development of collateral "neovascularization of the liver," thus preventing further ischemia. CONCLUSIONS: Although surgical retransplant still remains the standard treatment for hepatic artery thrombosis, organ shortages and high mortality still exist. Endovascular techniques are rapidly evolving, but these techniques are dependent on expertise available and, even in the best hands, have not proven to be effective at reversing hepatic artery thrombosis. The use of a multimodality endovascular approach could salvage the liver allografts, thereby preventing retransplant or facilitating transplant at a more elective setting.

Prostatic Artery Embolization After Failed Urological Interventions for Benign Prostatic Obstruction: A Case Series of Three Patients.

Benign prostate obstruction with associated lower urinary tract symptoms is a common diagnosis with multiple minimally invasive treatment options available. Herein, the authors describe three patients who failed prior different urological interventions who underwent prostate artery embolization with a subsequent improvement in symptoms. The positive response suggests that embolization may be an effective treatment alternative in this subset of patients.

Is Antibiotic Prophylaxis for Percutaneous Radiofrequency Ablation (RFA) of Primary Liver Tumors Necessary? Results From a Single-Center Experience.

PURPOSE: The purpose of this study was to evaluate need for antibiotic prophylaxis for radiofrequency ablation (RFA) of liver tumors in patients with no significant co-existing risk factors for infection. MATERIALS AND METHODS: From January 2004 to September 2013, 83 patients underwent 123 percutaneous RFA procedures for total of 152 hepatocellular carcinoma (HCC) lesions. None of the patients had pre-existing biliary enteric anastomosis (BEA) or any biliary tract abnormality predisposing to ascending biliary infection or uncontrolled diabetes mellitus. No pre- or post-procedure antibiotic prophylaxis was provided for 121 procedures. Data for potential risk factors were reviewed retrospectively and analyzed for the frequency of infectious complications, including abscess formation. RESULTS: One patient (1/121 (0.8%) RFA sessions) developed a large segment 5 liver abscess/infected biloma communicating with the gallbladder 7 weeks after the procedure, successfully treated over 10 weeks with IV and PO antibiotic therapy and percutaneous catheter drainage. This patient did not receive any antibiotics prior to RFA. During the procedure, there was inadvertent placement of RFA probe tines into the gallbladder. No other infectious complications were documented. CONCLUSION: These data suggest that the routine use of prophylactic antibiotics for liver RFA is not necessary in majority of the patients undergoing liver ablation for HCC and could be limited to patients with high-risk factors such as the presence of BEA or other biliary abnormalities, uncontrolled diabetes mellitus, and large centrally located tumors in close proximity to central bile ducts. Larger randomized studies are needed to confirm this hypothesis.

Tip of the iceberg: subtle findings on traumatic knee radiographs portend significant injury.

Despite their low clinical yield, knee radiographs are among the most commonly acquired radiographic trauma studies in the emergency department. Although obvious fractures may be present, several subtler radiographic findings suggest internal derangement and significant injury. In this review, we provide an overview of traumatic knee radiography, including anatomy, acquisition techniques, and pitfalls with associated magnetic resonance imaging correlation when available.

Hypoxia induces chondrocyte-specific gene expression in mesenchymal cells in association with transcriptional activation of Sox9.

Endochondral bone is formed during an avascular period in an environment of low oxygen. Under these conditions, pluripotential mesenchymal stromal cells preferentially differentiate into chondrocytes and form cartilage. In this study, we investigated the hypothesis that oxygen tension modulates bone mesenchymal cell fate by altering the expression of genes that function to promote chondrogenesis. Microarray of RNA samples from ST2 cells revealed significant changes in 728 array elements (P < 0.01) in response to hypoxia. Real-time PCR on these RNA samples, and separate samples from C3H10T1/2 cells, revealed hypoxia-induced changes in the expression of additional genes known to be expressed by chondrocytes including Sox9 and its downstream targets aggrecan and Col2a. These changes were accompanied by the accumulation of mucopolysacharide as detected by alcian blue staining. To investigate the mechanisms responsible for upregulation of Sox9 by hypoxia, we determined the effect of hypoxia on HIF-1alpha levels and Sox9 promoter activity in ST2 cells. Hypoxia increased nuclear accumulation of HIF-1alpha and activated the Sox9 promoter. The ability of hypoxia to transactivate the Sox9 promoter was virtually abolished by deletion of HIF-1alpha consensus sites within the proximal promoter. These findings suggest that hypoxia promotes the differentiation of mesenchymal cells along a chondrocyte pathway in part by activating Sox-9 via a HIF-1alpha-dependent mechanism.