Lymph sampling and lymphangiography via EUS-guided transesophageal thoracic duct puncture in a swine model.

Background: The thoracic duct plays an important role in fluid balance, lipid absorption, and transport of immunologically active cells. The thoracic duct is difficult to access but is readily identified by EUS. The present study assessed the feasibility of EUS identification and EUS-guided puncture of the thoracic duct in a swine model.

Carbon dioxide digital subtraction angiography: the practical approach.

CO(2) has developed into a viable alternative to iodinated contrast for digital vascular imaging. Because CO(2) is a gas, it has a unique set of properties that affords certain advantages over iodinated contrast in a variety of settings. However, if CO(2) is used inappropriately, these same properties are associated with a unique set of rare but potentially harmful events.

Maternal atherogenic diet in swine is protective against early atherosclerosis development in offspring consuming an atherogenic diet post-natally.

Atherosclerosis found early in life suggests that it may arise from fetal adaptations during development in utero. We evaluated the effect of a maternal atherogenic diet on atherosclerosis development in offspring. Aortic fat deposition was evaluated by Sudan IV staining and coronary atherosclerosis was assessed histologically.

Laparoscopic and percutaneous radiofrequency ablation of the kidney: acute and chronic porcine study.

Objectives: The chronic effects of renal radiofrequency ablation are unknown. Herein, we investigate the anatomic and physiologic sequelae of laparoscopic and percutaneous renal radiofrequency ablation in acute and chronic porcine models.

Methods: Our study comprised two phases-an acute phase and a chronic phase.

Aortic prosthetic graft infections: radiologic manifestations and implications for management.

Prosthetic graft infections are an uncommon complication of aortic bypass. These infections may have serious sequelae such as limb loss and can be lethal. They are hard to eradicate and, under certain circumstances, difficult to diagnose.

Relative ultrasonographic echogenicity of standard, dimpled, and polymeric-coated needles.

Purpose: To use quantitative ultrasonographic measurements to compare the effect of a polymeric coating designed to increase needle echogenicity to commercially available needles.

Materials And Methods: Commercially available standard smooth and dimpled echogenic tip 21-gauge needles established reference levels of echogenicity in gelatin-based and turkey breast phantoms. Examples of both types of needles were coated with a thin polymeric film that utilizes entrapped microbubbles of air on its surface to increase echogenicity.

Complications and technical limitations of hepatic arterial infusion catheter placement for chemotherapy.

Purpose: To determine the rate of complications associated with hepatic arterial infusion (HAI) catheter placement, as well as technical success related to liver perfusion.

Materials And Methods: The authors reviewed 44 patients who underwent 106 HAI catheter placements, including 15 men and 29 women with an average age of 55 years (range, 32-82 years). One to nine placements were performed per patient with 61 (58%) via the left brachial artery, 40 (38%) via the right femoral artery, and five (4%) via the left femoral artery.

Thrombolytic enhancement with perfluorocarbon-exposed sonicated dextrose albumin microbubbles.

Whereas low-intensity, high-frequency ultrasound (US) alone appears to cause minimal thrombolysis, US combined with air-filled microbubbles does increase the amount of urokinase (UK)-mediated clot lysis (CL). Because this phenomenon may be mediated by cavitation-induced streaming, we hypothesized that perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles, which are more stable than air-filled microbubbles, may also enhance US-induced thrombolysis. We measured the percentage CL of equally sized thrombi (1.

Biliary strictures in liver transplant recipients: treatment with metal stents.

Purpose: To determine initial and long-term results of metal stent placement in biliary strictures that failed to respond to balloon dilation.

Materials And Methods: Sixty-one metal stents were placed in 36 liver transplant recipients (age range, 3 months to 71 years) with biliary strictures that failed to respond to balloon dilation. Patients were followed up for up to 5 years.

Awakenings to the pathogenicity of urease and the requirement for continuous long term therapy.

Urease is an enzyme found in plants and bacteria, but not mammals. It catalyzes the conversion of urea to carbon dioxide and ammonia. Ammonia shortens the life span of cells; and higher concentrations cause tissue necrosis and cytolysis.

Ultrasound-assisted thrombolysis.

Rationale And Objectives: Current use of thrombolytic agents to lyse thrombus, though safe, is complicated by stroke, bleeding, and clot embolization. Therapy may be protracted, resulting in further ischemia and possible tissue loss. Peripheral arterial and graft occlusions often require several hours of thrombolytic therapy, which may occasionally exceed 48 hours and may also require expensive intensive care monitoring.

An unopened titanium Greenfield IVC filter: intravascular ultrasound to reveal associated thrombus and aid in filter opening.

A titanium Greenfield filter did not open following placement in the infrarenal inferior vena cava (IVC). Abdominal radiograph and cavogram showed no definite reason for filter malfunction. Intravascular ultrasound (IVUS) demonstrated the unopened filter in the IVC with thrombus binding the legs.

Effectiveness of a prolapsed bird's nest filter.

Purpose: The authors evaluated the variable deployment of the Bird's Nest filter, including frequency and extent of prolapse in clinical use, and analyzed the effects of this variability on clot-trapping efficiency with an in vitro model.

Materials And Methods: In the clinical placement of 20 filters, the average length of cephalic filter wires from the center of the filter was measured from radiographs obtained immediately after placement. To analyze the effects of prolapse, a variable-rate pump was used to mimic the effects of respiration on IVC flow.

Inhibition of smooth muscle cell proliferation and experimental angioplasty restenosis by beta-cyclodextrin tetradecasulfate.

Heparin inhibits smooth muscle cell proliferation in vitro, a property that makes it potentially useful in preventing restenosis after angioplasty. Its utility in this setting is limited by the inability to use high doses (secondary to anticoagulant effects) and the need for subcutaneous administration. We tested the ability of beta-cyclodextrin tetradecasulfate (CDT), a nonanticoagulant synthetic heparin mimic, to inhibit smooth muscle cell proliferation in vitro and tested its efficacy when orally administered for the prevention of angioplasty restenosis in a rabbit atherosclerosis model.

The mythology of povidone-iodine and the development of self-sterilizing plastics.

The predominance of elemental iodine as a chemical antiseptic has been established during a century. Free iodine is effective for treatment and prevention of infection. Iodophors, such as povidone-iodine, have replaced elemental iodine in clinical use.

Shear stress in the performance of esophageal dilation: comparison of balloon dilation and bougienage.

While both the balloon catheter and the bougie are effective for esophageal dilation, each has its proponents. From a biomechanical point of view, the two methods should differ significantly, since bougienage depends on advancing a tapered dilator to generate radial force and balloon catheter dilation depends solely on balloon inflation to generate its radial dilating force. In a series of equivalent esophageal stenoses made by suture plication in swine esophageal segments, the authors measured shear force and radial force generated by dilation with a Maloney bougie, a Savary-Gilliard bougie, and an esophageal balloon.

Restenosis and successful angioplasty: histologic-radiologic correlation.

Histologic analysis was undertaken on 24 perfusion-fixed arteries from New Zealand White rabbits that had undergone percutaneous transluminal angioplasty (PTA) of a focal arteriosclerotic lesion in the femoral artery 1 month earlier. Experiments representative of occlusion, restenosis (greater than or equal to 50% stenosis), a good result (less than 50% stenosis), or aneurysm (as defined angiographically) were randomly selected for histologic analysis. Histologic findings were compared with those in untreated control lesions in the contralateral femoral artery.

Photoplethysmographic documentation of improved microcirculation after pentoxifylline therapy.

Pentoxifylline is the prototype of a new class of drugs that improve peripheral blood flow mainly by increasing red blood cell flexibility. Few studies have been performed to objectively evaluate the effect of the drug in a routine clinical setting. In 11 patients with intermittent claudication, photoplethysmography was used to monitor the effect of pentoxifylline on the microcirculation in the lower extremities.

Sources of error in arterial morphometric measurements.

The authors used radiopaque vascular casts to test a new computer-based analysis method that employs a densitometric profile to determine arterial diameters. Results from this method were compared with those obtained with caliper measurements of overhead projection images of the radiograph and direct caliper measurements of the vascular cast. In addition, the corresponding in vivo angiograms were compared with the measurements obtained from the vascular casts.

Effects of angioplasty balloon inflation time on arterial contractions and mechanics.

The purpose of this study was to characterize and compare the immediate effects of short and long angioplasty inflation times on arterial contractions and passive mechanics and thereby determine if there is a potential advantage obtained by increasing the duration of balloon inflation. In each of 10 nonatherosclerotic New Zealand rabbits, one external iliac artery was dilated for 20 seconds, and the contralateral artery was dilated for 2 minutes. Although angioplasty stretched the arteries 27% and 30% for the short and long dilations respectively, the pre- and post-angioplasty arteriographic diameters were not different.

Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow.

To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.