EFFECTS OF NEUROLYTIC CONCENTRATIONS OF ALCOHOL AND PHENOL ON DACRON AND GORE-TEX VASCULAR PROSTHETIC GRAFTS

Background and Objectives. Neurolytic nerve block, using either alcoho l (A) or phenol (P), is frequently used to treat intractable pain. How ever, these agents may disrupt the integrity of prosthetic vascular gr afts. To investigate this possibility, the tensile strength of Dacron (Meadox Medicals, Oakland, NJ) and Gore-Tex (W.L. Gore Associates, Fla gstaff, AZ) vascular grafts was determined after in vitro exposure to various clinically used concentrations of A or P. Methods. Segments of Dacron and Gore-Tex graft were placed in the following solutions: sal ine (S), 6% and 9% P, and 25%, 50%, 75%, and 100% A, and stored at 23- degrees +/- 1-degree-C for 72 hours. Axial maximum load (in kilonewton s, KN) and strain (in mm/mm) were determined with an Instron universal testing machine (Instron Corporation, Camden, MA). Samples from the S , 9% P, and the 100% A groups were evaluated using a scanning electron microscope. Results. Dacron tensile strength decreased a maximum of 2 3% after exposure to 50%, 75%, and 100% A. Dacron strain capacity decr eased after exposure to A (50%, 75%, 100%) and P (6%, 9%). Scanning el ectron microscope of both P and A showed significant degradation. No c hanges were found in the Gore-Tex group after exposure to P or A, howe ver, scanning electron microscope of the 100% A sample showed moderate fiber degradation. Conclusions. The study shows that Dacron woven gra fts are degraded by concentrations of A of at least 50%, and to a less er extent, concentrations of at least 6%, while Gore-Tex had only mini mal changes. While neurolytic block offers distinct advantages in pati ents with terminal cancer pain, the findings suggest that the use of m ore conservative modalities, such as oral medication regimens, be cons idered for the treatment of intractable pain in patients with vascular prosthetic grafts that are proximate to the proposed site of neurolys is.