Login to Access Video or Poster Abstract: MP52-09
Sources of Funding: This study was supported the Sidney Kimmel Center for Prostate and Urologic Cancers, the NIH/NCI Cancer Center Support Grant P30_x000D_ CA008748, and by David H. Koch through the Prostate Cancer Foundation

Introduction

Intraoperative identification of nerves is essential in various surgical scenarios, where nerve injury can be inadvertent and cause loss of function. We compared the diagnostic efficacy of intravenous (IV) vs. topical administration of the fluorophore GE3126 to identify nerves in a surgical model.

Methods

Surgical models were created using Yorkshire pigs. Under general anesthesia, a laparotomy was performed and the retroperitoneum exposed. GE3126 was administered using an IV or topical route. Fluorescence was recorded using open and laparoscopic imaging systems. A retroperitoneal dissection was performed to harvest distinct fluorescent structures resembling nerves. Pigs were euthanized at the end of the procedure. Pathologic analysis of harvested tissues included microscopy and staining with hematoxylin and eosin (H&E) and Luxol fast blue. Fisher&[prime]s exact test was used to compare the positive predictive value of fluorescence after intravenous vs. topical administration of GE3126.

Results

Specimens were collected from 5 animals after IV administration of GE3126 (dose range, 0.7-10 mg/kg), and from 5 animals after topical administration of GE3126 (dose range, 100-900 mcg) A total of 15 distinct fluorescent structures were harvested after IV injection; 11 were harvested after topical application. The positive predictive value for nerve identification was 11/15 (73%) for the IV route vs. 8/11 (73%) for the topical route (p=1.0). The average diameter of nerves identified was 560 microns, ranging from 20 to 2,072 microns, with a similar diameter distribution between specimens collected after IV and topical administration.

Conclusions

Real-time anatomical enhancement of nerves was consistently achieved in a large animal model using the fluorophore GE3126, with similar diagnostic efficacy whether administered using an IV or topical route. Research in human subjects is warranted.

Funding

This study was supported the Sidney Kimmel Center for Prostate and Urologic Cancers, the NIH/NCI Cancer Center Support Grant P30_x000D_ CA008748, and by David H. Koch through the Prostate Cancer Foundation