Arterial distribution characteristics of Embozene particles and comparison with other spherical embolic agents in the porcine acute embolization model

PURPOSE

To determine the arterial distribution pattern of the embolic agent Embozene within the porcine kidney and compare it with those of other spherical embolic agents.

MATERIALS AND METHODS

Embozene, Embosphere, Bead Block, and Contour SE in size classes of 100-300 microm, 500-700 microm, and 700-900 microm and Embozene and Embosphere in the size class of 40-120 microm were used for total arterial occlusion in minipig kidneys. Organs were evaluated microscopically regarding vascular distribution of the different embolic agents and particle sizes.

RESULTS

The following variations of arterial distribution were identified. In the 40-120-microm size class, Embosphere particles penetrated significantly deeper compared with Embozene (P = .04). In the 100-300-microm size class, Bead Block showed a significantly deeper distribution as microscopy identified particles in arteries much smaller than their nominal size. In the 500-700-microm size class, Embosphere and Contour SE showed a deeper distribution. The most uniform arterial distribution was observed in the 700-900 microm size class,. However, few Embosphere and Contour SE particles were found in arcuate arteries, also indicating a distal distribution.

CONCLUSIONS

Throughout the four most-used size classes, from very small (40-120 microm) to large (700-900 microm), the distribution characteristics of the four tested materials vary substantially. Particularly, small Embosphere particles and small Bead Block particles showed a more distal distribution, as did medium-sized Embosphere and Contour SE particles. In the largest investigated size class, the distribution was more uniform. In general, the Embozene particles are very uniform in size, and they seem to reach vessels closely corresponding to their nominal size.

Transarterial embolization of primary and secondary tumors of the skeletal system

Percutaneous transcatheteral embolizations of primary and secondary bone tumors are important minimal invasive angiographic interventions of the skeletal system. In most of the cases embolization is performed for preoperative devascularization or as a palliative measure to treat tumor-associated pain or other tumor bulk symptoms. The transarterial embolization of primary and secondary tumors of the skeletal system has been developed to a safe and very effective method. Indications, techniques, results and complications of this minimal invasive interventional therapy for treatment of primary and secondary bone tumors are described and discussed and compared with the newer literature and our own results.

Paclitaxel-induced arterial wall toxicity and inflammation: part 2--long-term tissue response in a minipig model

PURPOSE

In part 1 of the present study, the authors demonstrated that coronary paclitaxel uptake from drug eluting stents (DESs) was not dependent on exposure time and dose. In this second part, the effect of the different paclitaxel dose densities on long-term biologic behavior was evaluated.

MATERIALS AND METHODS

In 40 minipigs, (with 4- and 12-week follow-up), identical stents with the same three paclitaxel dose densities as in part 1 were implanted in the right coronary artery. Minipigs implanted with Polyzene-F nanocoated stents served as the control group. Quantitative angiography measuring average luminal diameter (from three in-stent reference points), minimal luminal diameter (from the point of maximum in-stent stenosis), average late loss, maximum late loss, and binary stenosis rate was performed, as was microscopy to determine neointimal thickening, injury score, and inflammation.

RESULTS

All three DESs were associated with a high average late loss, binary stenosis rate, and neointimal thickening, without significant differences. Drug-free stents had significantly less late in-stent stenosis: there was an average late loss of 0.3 mm +/- 0.3 in drug-free stents versus 0.8 mm +/- 0.2 in intermediate-dose stents and 1.5 mm +/- 0.6 in high-dose stents (P = .04). DES-associated inflammation was high in all DESs and six times higher as in the drug-free stents (Kornowski scores of 0.2 +/- 0.1 in drug-free stents, 1.3 +/- 0.9 in low-dose stents, 1.7 +/- 0.8 in intermediate-dose stents, and 1.3 +/- 1.0 in high-dose stents; P = .04). It worsened with time in all DESs, as did late in-stent stenosis.

CONCLUSIONS

The extensive and long-term retention of paclitaxel even in a low-dose formulation, at least according to the present labeling of DESs, might be associated with negative long-term results with regard to inflammation and late in-stent stenosis.

Reduction of late in-stent stenosis in a porcine coronary artery model by cobalt chromium stents with a nanocoat of polyphosphazene (Polyzene-F)

The purpose of this study was to investigate the potential of nanoscale coating with the highly biocompatible polymer Polyzene-F (PZF), in combination with cobalt chromium and stainless steel stents, to reduce in-stent stenosis, thrombogenicity, and vessel wall injury and inflammation. One bare cobalt chromium, PZF-nanocoated stainless steel or PZF-nanocoated cobalt chromium stent was implanted in right coronary artery of 30 mini-pigs (4- or 12-week follow-up). Primary study end points were in-stent stenosis and thrombogenicity. Secondary study end points were vessel wall injury and inflammation as evaluated by microscopy and a new immunoreactivity score applying C-reactive protein (CRP), tumor-necrosis factor alpha (TNFalpha), and TGFbeta. At 12 weeks, angiography showed a significantly lower average loss in lumen diameter (2.1% +/- 3.05%) in PZF-nanocoated cobalt chromium stents compared with stents in the other groups (9.73% +/- 4.93% for bare cobalt chromium stents and 9.71% +/- 7% for PZF-nanocoated stainless steel stents; p = 0.04), which was confirmed at microscopy (neointima 40.7 +/- 16 lm in PZF-nanocoated cobalt chromium stents, 74.7 +/- 57.6 lm in bare cobalt chromium stents, and 141.5 +/- 109 lm in PZF-nanocoated stainless steel stents; p = 0.04). Injury and inflammation scores were low in all stents and were without significant differences. PZF-nanocoated cobalt chromium stents provided the highest efficacy in reducing in-stent stenosis at long-term follow-up. The PZF nanocoat proved to be biocompatible with respect to thromboresistance and inflammation. Our data suggest that its combination with cobalt chromium stents might provide an interesting passive stent platform.

Paclitaxel-induced arterial wall toxicity and inflammation: tissue uptake in various dose densities in a minipig model

PURPOSE

Paclitaxel is an antiproliferative agent in drug-eluting stents with largely unknown tissue interaction. Toxicity might result from overdosage and/or accumulation. Part 1 of this two-step study investigated how paclitaxel uptake depends on dose density, coronary drug transfer kinetics, and elution efficacy.

MATERIALS AND METHODS

With cobalt chromium stents and Polyzene-F nanoscale coating, low, intermediate, and high paclitaxel dose densities (25 microg, 50 microg, and 150 microg per stent) were investigated in porcine right coronary arteries (RCAs). Coronary and myocardial tissue concentration measurements and determination of on-stent paclitaxel and plasma concentrations were performed at 2, 8, 24, and 72 hours.

RESULTS

For all stents, uptake was similar at all time intervals (paclitaxel RCA concentration range, 1,610-33,300 ng). Low- and intermediate-dose stents showed similar RCA concentrations, but those for high-dose stents were three times greater. Residual on-stent paclitaxel concentration was not time-dependent, at 33.3% on low-, 30.6% on intermediate-, and 17.4% on high-dose stents. Paclitaxel was measurable in only the plasma immediately after stent placement, with a linear dose relationship and a timely regression: measurements in high-dose stents were 0.0454-0.656 ng/mL at 1 minute and 0.0329-0.0879 ng/mL at 5 minutes. Untreated control samples of the left coronary artery showed a linear dose-dependent concentration (12.6 ng/g, 21.2 ng/g, and 85.2 ng/g).

CONCLUSIONS

Overall coronary paclitaxel uptake is fairly independent from the baseline overall dose density and, hence, depends on immediate binding mechanisms of the arterial wall. This is supported by the fact that, regardless of the applied dose density, the kinetics of paclitaxel uptake did not follow an exposure time pattern.

Lung sequestration: a rare cause for pulmonary symptoms in adulthood

BACKGROUND

Lung sequestration is a rare congenital pulmonary disorder and is usually diagnosed in children with recurrent pulmonary infections. Lung sequestrations are not commonly found to be a cause of respiratory symptoms in adults.

OBJECTIVES

It was the aim of this study to show that pulmonary sequestration is rare in advanced age and can be accompanied by severe pulmonary symptoms.

METHODS

We conducted a case series analysis of patient characteristics, symptoms, diagnosis and treatment of 11 adults with a lung sequestration at the Thoraxklinik Heidelberg between 2001 and 2009.

RESULTS

From 2001 to 2009, intralobar lung sequestration was diagnosed and treated in 11 adults aged 19 to 58 years with an average age of 39.9 ± 11.3 years and a male:female distribution of 5:6. In 3 patients (27.3%), the predominant symptom was hemoptysis. Recurrent pulmonary infections occurred in 1 patient (9.1%); pneumonia and lung abscess were detected in 2 patients (18.2%). In 3 cases (27.3%), dry cough was the predominant symptom, and in only 2 cases (18.2%), lung sequestration was asymptomatic. Eight patients (72.7%) were diagnosed by imaging techniques prior to surgery. In 3 cases (27.3%), diagnosis was made intraoperatively and by pathological examination. Surgical intervention included 7 lobectomies (63.6%), 3 wedge resections (27.3%) and 1 (9.1%) segmentectomy.

CONCLUSION

Lung sequestration in adults is rare, but it can cause severe pulmonary symptoms. In cases of recurrent pulmonary infections of identical localization or recurrent hemoptysis, lung sequestration should be considered in order for the diagnosis to be made rapidly. Surgical resection is the treatment of choice.

Protocol of an expertise based randomized trial comparing surgical Venae Sectio versus radiological puncture of Vena Subclavia for insertion of Totally Implantable Access Port in oncological patients

Background

Totally Implantable Access Ports (TIAP) are being extensively used world-wide and can be expected to gain further importance with the introduction of new neoadjuvant and adjuvant treatments in oncology. Two different techniques for the implantation can be selected: A direct puncture of a central vein and the utilization of a Seldinger device or the surgical Venae sectio. It is still unclear which technique has the optimal benefit/risk ratio for the patient.

Design

A single-center, expertise based randomized, controlled superiority trial to compare two different TIAP implantation techniques. 100 patients will be included and randomized pre-operatively. All patients aged 18 years or older scheduled for primary elective implantation of a TIAP under local anesthesia who signed the informed consent will be included. The primary endpoint is the primary success rate of the randomized technique. Control Intervention: Venae Sectio will be employed to insert a TIAP by a surgeon; Experimental intervention: Punction of V. Subclavia will be used to place a TIAP by a radiologist. Duration of study: Approximately 10 months, follow up time: 90 days.

Organisation/Responsibility

The PORTAS 2 – Trial will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The Center of Clinical Trials at the Department of Surgery, University Hospital Heidelberg is responsible for design and conduct of the trial including randomization and documentation of patients' data. Data management and statistical analysis will be performed by the independent Institute for Medical Biometry and Informatics (IMBI), University of Heidelberg.

Trial Registration

The trial is registered at ClinicalTrials.gov (NCT00600444).

Regional Radiation Pneumonitis After SIRT of a Subcapsular Liver Metastasis: What is the Effect of Direct Beta Irradiation?

We herein present a patient undergoing selective internal radiation therapy with an almost normal lung shunt fraction of 11.5%, developing histologically proven radiation pneumonitis. Due to a predominance of pulmonary consolidations in the right lower lung and its proximity to a large liver metastases located in the dome of the right liver lobe a Monte Carlo simulation was performed to estimate the effect of direct irradiation of the lung parenchyma. According to our calculations direct irradiation seems negligible and RP is almost exclusively due to ectopic draining of radioactive spheres.

Coil embolization of a thoracic aorta hematoma with branch artery pseudoaneurysm - case report

Background

A thoracic aorta hematoma with branch artery pseudonaneurysm is a very rare complication of thoraric blunt trauma. The standard treatment of this type of injury is aortic endograft placement.

Case presentation

We present a case in which a thoracic aorta hematoma with branch artery pseudoaneurysm was treated with coil embolization instead of endografting.

Conclusions

Coil embolization of aortic injuries may be a safe and definitive treatment alternative in selected cases. This technique has the potential to reduce the risk of procedure-related complications.

The History of the Transjugular Intrahepatic Portosystemic Shunt

Few, if any, developments in the past three decades have advanced the field of portal hypertension more than the use of transjugular intrahepatic portosystemic shunts (TIPS). Initially pursued in animal studies more than 50 years ago, and discovered serendipitously, TIPS quickly became used clinically in the treatment of refractory esophageal hemorrhage. The technique is now used for many other clinical indications as well as to bridge patients to liver transplantation. Several technical advancements have improved short- and long-term outcomes of the procedure. This article will review the development of TIPS from its inception to the current state of care regarding this important minimally invasive option for patients with portal hypertension.