Quantification of intrahepatic portosystemic shunting after placement of a transjugular intrahepatic portosystemic shunt.

PURPOSE: To quantify portosystemic shunting and hepatic portal perfusion after placement of a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: Technetium-99m macroaggregated albumin (MAA) was injected directly into the portal veins of nine asymptomatic patients 3 months after TIPS placement. Portosystemic shunting was quantified by comparing counts in the lungs with those in the liver. One cirrhotic patient and one healthy patient who received portal MAA injections were used as controls. RESULTS: No portosystemic shunting was found in the healthy patient. In the cirrhotic control patient, 77% of the injected activity was in the lungs. Patients with portosystemic shunts had even more activity in the lungs. Even stenotic shunts diverted greater than 80% of portal blood flow systemically. Flow through the TIPS ranged from 84% to 100% (average, 93%); these fractions of flow correlated inversely with portosystemic pressure gradients. CONCLUSION: Cirrhotic livers may divert much of the portal blood systemically before TIPS placement. Afterward, this proportion rises, and most portal flow is diverted into the pulmonary circulation.

Percutaneous transhepatic drainage of the nondilated biliary system.

PURPOSE: The authors sought to develop a safe, efficacious technique for percutaneous transhepatic drainage of nondilated biliary systems. PATIENTS AND METHODS: Twenty-three drainage procedures were performed on 14 consecutive patients with nondilated ducts. Fourteen procedures were carried out for primary placement of a transhepatic biliary drain, eight for placement of a second drain, and one for placement of a third drain. Drainage catheter access into the biliary tree was gained via direct puncture of a peripheral duct (fourth order or smaller branch) in four procedures. In the remaining 19 procedures, peripheral duct punctures were facilitated by retrograde passage of a 5-F catheter from a previous, remote percutaneous access site into the fourth-order duct to be punctured. Nine of these 19 duct punctures were facilitated by the use of a nitinol Goose Neck snare passed through the intraductal catheter. RESULTS: Of the access methods used, the nitinol snare technique was the fastest. Successful peripheral access was achieved in all patients without bleeding complications. One patient developed symptoms of bacteremia, which resolved within 12 hours with antibiotic therapy and external biliary drainage. CONCLUSION: Percutaneous peripheral access can be achieved safely in the nondilated biliary tree and can obviate surgery for some patients and facilitate future interventions.

Localization of the portal vein for transjugular catheterization: percutaneous placement of a metallic marker with real-time US guidance.

Transjugular catheterization of the portal vein can be used to form a portosystemic shunt. Conventionally, the passage of a needle from the hepatic vein into the portal vein is performed with fluoroscopic monitoring only. Several methods to target the portal vein have been previously reported, including transhepatic venous catheterization, indirect portography (arterial catheterization), or skin marking based on ultrasound (US) mapping of portal landmarks. The authors used realtime US guidance to percutaneously place a small marking wire in the parenchyma next to the portal bifurcation. A 0.018-inch-diameter, 5-mm-long platinum wire is delivered through a 22-gauge echo-tipped needle placed adjacent to the right portal vein. This marking wire enabled rapid entry into the portal vein, helped avoid extrahepatic puncture, and was useful during stent deployment and positioning.

Testicular ultrasonography after chemotherapy for germ cell neoplasm: significance of highly hyperechoic lesions.

The sonographic appearance of the testis after administration of chemotherapy for metastatic germ cell neoplasm is not well known. Fifty-six patients (60 testes) who were previously treated with chemotherapy for metastatic germ cell neoplasm (originally diagnosed by removal of the contralateral testis or by biopsy of metastatic disease) underwent sonography followed by orchiectomy. The sonographic characteristics found to predict viable intratesticular tumor were: lesion size larger than 5 mm, fewer echoes than adjacent parenchyma (hypoechoic), inhomogeneous echo texture, poor margin definition, cystic areas, or highly hyperechoic foci within a hypoechoic lesion. Fibrosis was predicted by finding single or multiple small, highly hyperechoic lesions. These results suggest the potential for predicting the pathologic diagnosis in some patients after receiving chemotherapy for germ cell neoplasm.

Preaortic iliac venous confluence: 2-D and 3-D CT findings.

We report the CT diagnosis of a vascular anomaly of the iliac venous confluence. A preaortic iliac venous confluence is described as demonstrated on 2-D and 3-D computed tomography.

Thrombin-soaked coils: estimation of thrombin dose.

Thrombin-soaked coils have been used as embolic agents for the treatment of various conditions. Intravascular injection of thrombin also has been used for thrombus formation; however, the effects of high doses of intravascular thrombin may be detrimental. In an in vitro experiment, the dose of thrombin associated with transcatheter use of thrombin-soaked steel coils was estimated. The 8 mm x 5 cm, 0.038-inch coils absorbed an overall average dose of 38.4 U (USP) of thrombin when soaked in a solution of 10,000 U of thrombin per 10 mL of saline. The same size coils absorbed an overall average dose of 71.6 U of thrombin when soaked in a concentration of 20,000 U of thrombin per 10 mL of solution. Maximum single-coil absorbed doses were 45.6 and 88.2 U for 1,000 and 2,000 U/mL, respectively. A plateau in thrombin absorption occurred after 1 minute of soaking. Absorption of thrombin was maximized by soaking the coils in a vertical orientation; almost no thrombin was absorbed when the coils were soaked in a horizontal position.

MR demonstration of the nasal cycle in the beagle dog.

Magnetic resonance (MR) imaging of periodic engorgement of the erectile tissue surrounding the turbinates in the beagle dog yields remarkably quiet data that are well fitted by a single sinusoidal wave form. This observation holds in spite of right-left asymmetries in the distribution of the MR signal. The nasal cycle also occurs normally in humans. Judging from the clarity of its MR representation in the dog, it is possible that this phenomenon could be confused in human MR with upper respiratory congestion associated with pathological processes.

A microcomputer-based program for video analysis of chemotaxis under agarose.

We have developed a computerized system for the quantification of video images of cell migration patterns obtained in the chemotaxis under agarose assay. This system allows either manual or automatic measurement of standard parameters of chemotaxis, as well as quantification of three new parameters which reflect mean cell movement and chemokinesis. The parameters of mean cell population movement are not obtainable by the traditional analysis of the chemotaxis under agarose assay. Our system operates on an inexpensive microcomputer, is easy to use and provides data output in a format that is directly transferable to standard statistical packages.