A successful endovascular repositioning of migrated transjugular intrahepatic portosystemic shunt (TIPS) stent.

The transjugular intrahepatic portosystemic shunt (TIPS) procedure is performed to create an intrahepatic tract between the hepatic and portal veins which helps to shunt blood away from the hepatic sinusoids. This shunt decreases the portal venous pressure and secondary morbidities, including variceal bleeding and recurrent ascites. However, stent migration is a known complication of TIPS stent placement which may occur both during the procedure or postprocedural. We present a case of a 58-year-old male with history of liver cirrhosis in the setting of alcohol abuse and chronic hepatitis C infection who presented with melena and hematemesis. Esophagogastroduodenoscopy showed 4 columns of large grade IV esophageal varices with stigmata of recent bleeding. Despite endoscopic variceal banding, the patient had persistent episodes of hematemesis and became hemodynamically unstable requiring pressor support. The decision was made to proceed with emergent transjugular intrahepatic portosystemic shunt placement. After obtaining transhepatic portal access and initial stent deployment, the stent migrated from the TIPS tract into the main portal vein. While maintaining through-and-through wire access, the stent was successfully mechanically retracted using an angioplasty balloon and it was appropriately repositioned within the original TIPS tract. The stent was then further secured in place with a slightly larger stent which was deployed within the hepatic portion of the initially migrated stent. This technique was successful and obviated complete removal of the stent and follow-up imaging demonstrated patent flow and adequate positioning several months after the procedure.

Endovascular management of traumatic pseudoaneurysms.

BACKGROUND: Pseudoaneurysms (PAs) caused by traumatic injury to the arterial vasculature have a high risk of rupture, leading to life-threatening hemorrhage and mortality, requiring urgent treatment. The purpose of this study was to determine the technical and clinical outcomes of endovascular treatment of visceral and extremity traumatic pseudoaneurysms. METHODS: Clinical data were retrospectively collected from all patients presenting for endovascular treatment of PAs between September 2012 and September 2018 at a single academic level one trauma center. Technical success was defined as successful treatment of the PA with no residual filling on post-embolization angiogram. Clinical success was defined as technical successful treatment with no rebleeding throughout the follow-up period and no reintervention for the PA. RESULTS: Thirty-five patients (10F/25M), average age (± stdev) 41.7 ± 20.1 years, presented with PAs secondary to blunt (n = 31) or penetrating (n = 4) trauma. Time from trauma to intervention ranged from 2 h - 75 days (median: 4.4 h, IQR: 3.5-17.1 h) with 27 (77%) of PAs identified and treated within 24 h of trauma. Average hospitalization was 13.78 ± 13.4 days. Ten patients underwent surgery prior to intervention. PA number per patient ranged from 1 to 5 (multiple diffuse). PAs were located on the splenic (n = 12, 34.3%), pelvic (n = 11, 31.4%), hepatic (n = 9, 25.7%), upper extremity/axilla (n = 2, 5.7%), and renal arteries (n = 1, 2.9%). Technical success was 85.7%. Clinical success was 71.4%, for technical failure (n = 5), repeat embolization (n = 1) or post-IR surgical intervention (n = 4). There was no PA rebleeding or reintervention for any patient after discharge over the reported follow-up periods. Three patients died during the trauma hospitalization for reasons unrelated to the PAs. CONCLUSIONS: Endovascular treatment of traumatic visceral and extremity PAs is efficacious with minimal complication rates and low reintervention requirements.

The off-label use of the Amplatzer muscular VSD occluder for large patent ductus arteriosus: a case report and review.

A percutaneous approach to the closure of patent ductus arteriosus (PDA) is the preferred procedure in the majority of cases. However, there is little experience with percutaneous closure of unusually large PDA. We report the case of a 28-year-old female with moderate left ventricular dilation and pulmonary hypertension resulting from a large 16 mm PDA. Percutaneous closure was successfully performed using an off-label Amplatzer muscular ventricular septal defect occluder after intravascular ultrasound assessment. Technical challenges, including accurate assessment of defect size and device selection are exemplified along with a comprehensive overview of the available literature.

Water-soluble complexes of star-shaped poly(acrylic acid) with quaternized poly(4-vinylpyridine).

The interaction of star-shaped poly(acrylic acid) having various numbers of arms (5, 8, and 21) and a strong cationic polyelectrolyte, viz., poly( N-ethyl-4-vinylpyridinium bromide), was examined at pH 7 by means of turbidimetry and dynamic light scattering. Mixing aqueous solutions of the oppositely charged polymeric components was found to result in phase separation only if their base-molar ratio Z = [N+]/[COO (-) + COOH] exceeds a certain critical value ZM ( ZM < 1); this threshold value is determined by the number of arms of the star-shaped polyelectrolyte and the ionic strength of the surrounding solution. At Z < ZM, the homogeneous aqueous mixtures of the oppositely charged polymeric components contain two types of complex species clearly differing in their sizes, with the fractions of these species appearing to depend distinctly on the number of arms of the star-shaped poly(acrylic acid), the base-molar ratio of the oppositely charged polymeric components in their mixtures, and the ionic strength of the surrounding solution. The small complex species (major fraction) are assumed to represent the particles of the water-soluble interpolyelectrolyte complex whereas the large complex species (minor fraction) are considered to be complex aggregates.

Polyisobutylene-block-poly(methacrylic acid) diblock copolymers: self-assembly in aqueous media.

Ionic amphiphilic diblock copolymer polyisobutylene-block-poly(methacrylic acid) (PIBx-b-PMAAy), with various lengths of nonpolar (x=25-75) and polyelectrolyte (y=170-2600) blocks, spontaneously dissolve in aqueous media at pH>4, generating macromolecular assemblies, the aggregation number of which depends on external stimuli (pH and ionic strength). Spherical micellar morphology with a compact core formed by the PIB blocks and a swollen corona built up from the PMAA blocks was deduced by cryogenic transmission electron microscopy. The micelles were further characterized by means of dynamic and static light scattering as well as small-angle neutron scattering. The critical micellization concentration, estimated by means of fluorescence spectroscopy with the use of pyrene as a polarity probe, is decisively determined by the length of the PIB block and is insensitive to changes in the length of the PMAA block.