EUS-guided photodynamic therapy with verteporfin for ablation of normal pancreatic tissue: a pilot study in a porcine model (with video)

BackgroundEUS-guided photodynamic therapy (PDT) with the photosensitizing agent porfimer sodium has been shown to be effective in ablation of pancreatic tissue.ObjectiveThe objective of this study was to determine the effectiveness and safety of EUS PDT with verteporfin, a photosensitizer associated with less photosensitivity.DesignProspective investigation of 6 swine that received an IV injection of 6 mg/m2 of verteporfin before EUS.SettingHospital animal laboratory.InterventionsThe tail of the pancreas was located with EUS and was used to guide the placement of a light catheter. The pancreatic tail was exposed to 10, 15, or 20 minutes of laser light (689 nm).Main Outcome MeasurementsFollow-up abdominal CT, liver and renal function tests, and serum pancreatic enzymes levels were performed. Histology of the pancreas was obtained 7 days after the procedure on necropsy.ResultsLocalized tissue necrosis within the pancreatic tail (range 6.6-30.5 mm in diameter) was seen in all animals. The diameter of the necrotic tissue was directly related to the dose of light. No post-procedural complications were observed.LimitationsNormal animal model (lack of malignant tissue).ConclusionsEUS-guided PDT of porcine pancreas with verteporfin achieved localized pancreatic tissue ablation in a dose-related fashion.