Convection-enhanced delivery （CED） is a promising technique leveraging pressure-driven flow to increase penetration of infused drugs into interstitial spaces. We have developed a fiberoptic microneedle device for in...Convection-enhanced delivery （CED） is a promising technique leveraging pressure-driven flow to increase penetration of infused drugs into interstitial spaces. We have developed a fiberoptic microneedle device for inducing local sub-lethal hyperthermia to further improve CED drug distribution volumes, and this study seeks to quantitatively characterize this approach in agarose tissue phantoms. Infusions of dye were conducted in 0.6% （w/w） agarose tissue phantoms with isothermal conditions at 15 ℃, 20℃, 25 ℃, and 30 ℃. Infusion metrics were quantified using a custom shadowgraphy setup and image- processing algorithm. These data were used to build an empirical predictive temporal model of distribution volume as a function of phantom temperature. A second set of proof- of-concept experiments was conducted to evaluate a novel fiberoptic device capable of generating local photothermal heating during fluid infusion. The isothermal infusions showed a positive correlation between temperature and distribution volume, with the volume at 30℃ showing a 7-fold increase at 100 min over the 15 ℃ isothermal case. Infusions during photothermal heating （1064 nm at 500 mW） showed a similar effect with a 3.5-fold increase at 4 h over the control （0 mW）. These results and analyses serve to provide insight into and characterization of heat-mediated enhancement of volumetric dispersal.展开更多
BACKGROUND High-speed rotational atherectomy (HSRA) is most commonly used to modify calcified coronary artery lesions to facilitate stent deployment and expansion. The use of HSRA as an emergency rescue technique to r...BACKGROUND High-speed rotational atherectomy (HSRA) is most commonly used to modify calcified coronary artery lesions to facilitate stent deployment and expansion. The use of HSRA as an emergency rescue technique to release a fractured microcatheter has not been described. We report the use of HSRA in a case of a fracture trapped corsair tip that was impeding coronary flow causing a ST elevation myocardial infarct. CASE SUMMARY A 79 years old male was scheduled for elective percutaneous coronary intervention (PCI) to his left anterior descending artery (LAD). Given its calcific nature, a decision was made for upfront rotablation. During procedural preparations, the tip of an employed micro-catheter was separated from the shaft resulting in obstructing coronary flow and ST-segment elevation. The consensus was for an attempt bail out PCI strategy. A rotafloppy wire was advanced to the distal LAD using a corsair micro-catheter which was placed proximal to the occlusion site. Modification of the mid LAD segment was performed, resulting in mobilising the corsair tip, and deflecting it to a small diagonal branch. Following serial predilation, the procedure was completed using two overlapping drug eluting stents, jailing the corsair tip in the diagonal branch. The patient made uneventful recovery and was clinically stable at one year follow up. CONCLUSION HSRA may be offered as a bailed-out strategy to rescue fractured and jailed micro-catheter tip in high risk surgical cases.展开更多
基金the Coulter Foundation and NIH (NIH/NCI 1R21CA156078) for their funding of this project
文摘Convection-enhanced delivery （CED） is a promising technique leveraging pressure-driven flow to increase penetration of infused drugs into interstitial spaces. We have developed a fiberoptic microneedle device for inducing local sub-lethal hyperthermia to further improve CED drug distribution volumes, and this study seeks to quantitatively characterize this approach in agarose tissue phantoms. Infusions of dye were conducted in 0.6% （w/w） agarose tissue phantoms with isothermal conditions at 15 ℃, 20℃, 25 ℃, and 30 ℃. Infusion metrics were quantified using a custom shadowgraphy setup and image- processing algorithm. These data were used to build an empirical predictive temporal model of distribution volume as a function of phantom temperature. A second set of proof- of-concept experiments was conducted to evaluate a novel fiberoptic device capable of generating local photothermal heating during fluid infusion. The isothermal infusions showed a positive correlation between temperature and distribution volume, with the volume at 30℃ showing a 7-fold increase at 100 min over the 15 ℃ isothermal case. Infusions during photothermal heating （1064 nm at 500 mW） showed a similar effect with a 3.5-fold increase at 4 h over the control （0 mW）. These results and analyses serve to provide insight into and characterization of heat-mediated enhancement of volumetric dispersal.
文摘BACKGROUND High-speed rotational atherectomy (HSRA) is most commonly used to modify calcified coronary artery lesions to facilitate stent deployment and expansion. The use of HSRA as an emergency rescue technique to release a fractured microcatheter has not been described. We report the use of HSRA in a case of a fracture trapped corsair tip that was impeding coronary flow causing a ST elevation myocardial infarct. CASE SUMMARY A 79 years old male was scheduled for elective percutaneous coronary intervention (PCI) to his left anterior descending artery (LAD). Given its calcific nature, a decision was made for upfront rotablation. During procedural preparations, the tip of an employed micro-catheter was separated from the shaft resulting in obstructing coronary flow and ST-segment elevation. The consensus was for an attempt bail out PCI strategy. A rotafloppy wire was advanced to the distal LAD using a corsair micro-catheter which was placed proximal to the occlusion site. Modification of the mid LAD segment was performed, resulting in mobilising the corsair tip, and deflecting it to a small diagonal branch. Following serial predilation, the procedure was completed using two overlapping drug eluting stents, jailing the corsair tip in the diagonal branch. The patient made uneventful recovery and was clinically stable at one year follow up. CONCLUSION HSRA may be offered as a bailed-out strategy to rescue fractured and jailed micro-catheter tip in high risk surgical cases.
