Case report: Extended Isolated Stopflow Limb Infusion (EISLI) for highly malignant osteosarcoma - complete pathological tumor remission and implantation of a knee joint prosthesis

INTRODUCTION AND IMPORTANCE

An 18-year old osteosarcoma patient with a huge tumor mass at the distal femur and inguinal metastases was treated with the intention to preserve the leg and additionally treat the pelvic metastases locally. Therefore we modulated the technique of isolated limb perfusion.

CASE PRESENTATION

Isolated Limb Perfusion was performed as an Extended Isolated Limb Stop-Flow Infusion (EISLI) where the pelvis was included into the perfusion bed. Balloon catheters were placed in the arterial and venous bifurcation in the pelvis. For increasing the drug concentration at the tumor site, an angiographic catheter was placed arterially with the tip right in front of the tumor region. A Stop-Flow phase before the perfusion phase was applied.

CLINICAL DISCUSSION

After 4 cycles of EISLI the lesions in the pelvis disappeared and surgical resection of the tumor and implantation of an endoprosthesis was possible and successful. Histopathological findings showed no vital cells in the resected tumor region. Currently the patient is tumor free and does not show recurrence or pulmonal metastases for 18 months after the last induction treatment cycle.

CONCLUSION

With EISLI the inclusion of the pelvis is possible during isolated limb perfusion. In addition with low total dosages EISLI enabled drug concentrations many times higher at the tumor site than possible during systemic chemotherapy or standard isolated limb perfusion. It is a technique that allows limb preservation and treatment of positive lymphnodes in the groin. Quality of life is maintained during the Regional Chemotherapy (RCT).

A two-scale approach for CFD modeling of endovascular Chemofilter device

Two-scale CFD modeling is used to design and optimize a novel endovascular filtration device for removing toxins from flowing blood. The Chemofilter is temporarily deployed in the venous side of a tumor during the intra-arterial chemotherapy in order to filter excessive chemotherapy drugs such as Doxorubicin from the blood stream. The device chemically binds selective drugs to its surface thus filtering them from blood, after they have had the effect on the tumor and before they reach the heart and other organs. The Chemofilter consists of a porous membrane made of microscale architected materials and is installed on a structure similar to an embolic protection device. Simulations resolving the microscale structure of the device were carried out to determine the permeability of the microcell membrane. The resulting permeability coefficients were then used for macroscale simulations of the flow through the device modeled as a porous material. The microscale simulations indicate that greater number of microcell layers and smaller microcell size result in increased pressure drop across the membrane, while providing larger surface area for drug binding. In the macroscale simulations, the study of idealized prototypes show that the pressure drop can be reduced by increasing the membrane's tip angle and by decreasing the number of membrane's sectors. Such design, however, can conversely affect the overall drug binding. By decreasing the concentration of toxins in the cardiovascular system, the drug dosage can be increased while side effects are reduced, thus improving the effectiveness of treatment.

Optimization of an endovascular magnetic filter for maximized capture of magnetic nanoparticles

To computationally optimize the design of an endovascular magnetic filtration device that binds iron oxide nanoparticles and to validate simulations with experimental results of prototype devices in physiologic flow testing. Three-dimensional computational models of different endovascular magnetic filter devices assessed magnetic particle capture. We simulated a series of cylindrical neodymium N52 magnets and capture of 1500 iron oxide nanoparticles infused in a simulated 14 mm-diameter vessel. Device parameters varied included: magnetization orientation (across the diameter, "D", along the length, "L", of the filter), magnet outer diameter (3, 4, 5 mm), magnet length (5, 10 mm), and spacing between magnets (1, 3 mm). Top designs were tested in vitro using ⁸⁹Zr-radiolabeled iron oxide nanoparticles and gamma counting both in continuous and multiple pass flow model. Computationally, "D" magnetized devices had greater capture than "L" magnetized devices. Increasing outer diameter of magnets increased particle capture as follows: "D" designs, 3 mm: 12.8-13.6 %, 4 mm: 16.6-17.6 %, 5 mm: 21.8-24.6 %; "L" designs, 3 mm: 5.6-10 %, 4 mm: 9.4-15.8 %, 5 mm: 14.8-21.2 %. In vitro, while there was significant capture by all device designs, with most capturing 87-93 % within the first two minutes, compared to control non-magnetic devices, there was no significant difference in particle capture with the parameters varied. The computational study predicts that endovascular magnetic filters demonstrate maximum particle capture with "D" magnetization. In vitro flow testing demonstrated no difference in capture with varied parameters. Clinically, "D" magnetized devices would be most practical, sized as large as possible without causing intravascular flow obstruction.