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

Abstract

BACKGROUND: EUS-guided photodynamic therapy (PDT) with the photosensitizing agent porfimer sodium has been shown to be effective in ablation of pancreatic tissue. OBJECTIVE: The objective of this study was to determine the effectiveness and safety of EUS PDT with verteporfin, a photosensitizer associated with less photosensitivity. DESIGN: Prospective investigation of 6 swine that received an IV injection of 6 mg/m2 of verteporfin before EUS. SETTING: Hospital animal laboratory. INTERVENTIONS: The 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 MEASUREMENTS: Follow-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. RESULTS: Localized 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. LIMITATIONS: Normal animal model (lack of malignant tissue). CONCLUSIONS: EUS-guided PDT of porcine pancreas with verteporfin achieved localized pancreatic tissue ablation in a dose-related fashion.