title: Electrical superior vena cava isolation using photodynamic therapy in a canine model.
abstract: OBJECTIVE
  With the new era of multi-tip radiofrequency or balloon ablation catheters replacing the point-to-point ablation strategy, we aimed to determine the feasibility of a ring-laser catheter ablation technology to electrically isolate the superior vena cava (SVC) by exploring the advantages of the limitless catheter tip size possibly with the photodynamic therapy (PDT)-mediated ablation.
  
  
  RESULTS
  We developed a first-generation prototype of a circular-laser-mapping catheter by fitting a 7 cm plastic optical fibre onto a circular variable-loop Lasso™ mapping catheter. Following SVC venography, both the laser catheter and another ring catheter for monitoring the SVC potentials were placed at the SVC. After the systemic infusion of a photosensitizer (talaporfin sodium), we initiated the irradiation with an output of 1 W in three canines and 0.3 W in four. The creation of electrical isolation as well as occurrence of phrenic nerve injury, sinus node injury, and SVC stenosis were evaluated before, immediately after, and 1 month after the procedure. A PDT-mediated SVC isolation was successfully performed in all seven canines. The isolation was completed with a laser irradiation of 70.4 ± 71.4 J/cm under 30.9 ± 5.0 µg/mL of a photosensitizer without any sinus node injury, phrenic nerve palsy, or SVC stenosis in both the acute and chronic evaluations. The minimum isolation time of 270 s was not correlated with the laser input power or the photosensitizer concentration.
  
  
  CONCLUSIONS
  The electrical SVC isolation was successfully and instantly achieved using the PDT laser-ring catheter without any complications.
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan kimura@z7.keio.jp.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takatsuki
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Miyoshi
authors.affiliation: School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Mei
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Emiyu
authors.initials: E
authors.lastname: Ogawa
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Kashimura
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Katsumata
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nishiyama
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nishiyama
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tanimoto
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Aizawa
authors.affiliation: School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Arai
authors.affiliation: Department of Cardiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000200:Action Potentials; D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D057785:Catheters; D004285:Dogs; D004562:Electrocardiography; D004867:Equipment Design; D005240:Feasibility Studies; D007834:Lasers; D023421:Models, Animal; D010690:Phlebography; D010778:Photochemotherapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011166:Porphyrins / Q000008:administration & dosage; D013997:Time Factors; D014683:Vena Cava, Superior / Q000000981:diagnostic imaging / Q000601:surgery*
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; C053434:Talaporfin
keywords: Cardiac catheter ablation; Photodynamic therapy; Superior vena cava isolation; Talaporfin sodium