title: Assessment of safety, accuracy, and human CD34+ cell retention after intramyocardial injections with a helical needle catheter in a porcine model.
abstract: OBJECTIVE
  Assess accuracy of Helix injections via fluoroscopic-mapping and evaluate delivery safety.
  
  
  BACKGROUND
  Percutaneous intramyocardial-delivery of agents must be safe and accurate; retention is also important. A delivery system (Helical Infusion/Morph Guide-Catheter, Biocardia Inc) has been developed to improve maneuverability and stability of catheter-needle-myocardium intersection.
  
  
  METHODS
  Accuracy and safety: 12 swine underwent LV and coronary angiography via 8F sheath. Targeted delivery was assigned into LAD, LCX, or RCA. System was advanced into LV and 6 targeted intramyocardial dye injections (5 mm apart) delivered using fluoroscopy. After euthanization, hearts underwent gross and histologic evaluation. Retention was assessed by iron-oxide and fluorochrome labeled CD34+ cells. Cells were injected into 6 swine using same techniques. Delivery system was advanced into LV, and injections delivered using fluoroscopy. Euthanization was performed at 2 hr and hearts formalin fixed. MRI was performed on 6 treated hearts and 4 untreated controls. Blinded analysis performed by 2 radiologists. Two treated hearts underwent immunohistological analysis.
  
  
  RESULTS
  Accuracy and safety evaluation: 71/72 injections (98.6%) were within prespecified zone; 7/72 (9.7%) less than 5 mm apart. No adverse events occurred. MRI-presence of iron-oxide labeled CD34+ cells were correctly identified in 95% (19/20) of imaged injections. Anti-CD34+ antibody staining and fluorescence microscopy confirmed CD34+ cells in myocardium. Histology confirmed cell viability at fixation.
  
  
  CONCLUSIONS
  Helix system was accurate and safe. Retention of CD34+ cells was confirmed by MRI and immunohistology. Further preclinical studies are needed to characterize retention over time and quantify efficiency. Studies are needed to confirm accuracy, safety, and retention in humans.
authors.affiliation: Section of Cardiology, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois, USA. kumararun@health.missouri.edu
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar
authors.forename: Chris A
authors.initials: CA
authors.lastname: Haralampus
authors.forename: Micah
authors.initials: M
authors.lastname: Hughes
authors.forename: Didier
authors.initials: D
authors.lastname: Rouy
authors.forename: Nate
authors.initials: N
authors.lastname: Cresswell
authors.forename: Ryan
authors.initials: R
authors.lastname: Braun
authors.forename: David
authors.initials: D
authors.lastname: Turner
authors.forename: David
authors.initials: D
authors.lastname: Amrani
authors.forename: Delara
authors.initials: D
authors.lastname: Motlagh
authors.forename: Gary L
authors.initials: GL
authors.lastname: Schaer
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D057785:Catheters; D002470:Cell Survival; D017023:Coronary Angiography; D004867:Equipment Design; D005471:Fluoroscopy; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007273:Injections, Intramuscular; D008279:Magnetic Resonance Imaging; D008856:Microscopy, Fluorescence; D023421:Models, Animal; D009206:Myocardium / Q000378:metabolism*; D009339:Needles; D015641:Radiography, Interventional / Q000379:methods; D013552:Swine; D013997:Time Factors
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers