E. P. Ward1, J. Yang3, J. Delong1, J. Wang2, N. Mendez4, C. Barback5, S. Horgan1, W. Trogler3, A. Kummel3, S. Blair1 1University Of California – San Diego,General Surgery,San Diego, CA, USA 2University Of California – San Diego,Nanoengineering,San Diego, CA, USA 3University Of California – San Diego,Chemistry,San Diego, CA, USA 4University Of California – San Diego,Material Science,San Diego, CA, USA 5University Of California – San Diego,Radiology,San Diego, CA, USA
Introduction: The consequences of retained foreign bodies (RFB) are significant for all types of medical procedures, but in laparoscopic surgery, RFB such as lost surgical needles may cause a minimally invasive surgery (MIS) to be converted to an open surgery. MIS relies on an endoscopically placed camera for navigation and visual localization of a small item, such as a needle, can be daunting and time consuming. A dual-purpose film to coat surgical needles was developed to augment localization of needles under UV (black light) for open procedures and near infrared (NIR) light for MIS cases using specialized fluorescent laparoscopes.
Methods: Epoxy was used as the matrix for dansyl chloride (DC) and indocyanine green (ICG) as visible and NIR labels, respectively, in a single film. The needles were coated via dip coating with methanol cosolvent and subsequently cured at room temperature to form a clear polymer film with tunable thickness ranging from 10 to 30 um. With UV excitation at 390 nm, DC emits green fluorescence at 520 nm. With 980 nm NIR excitation, ICG dye emits NIR light above 1000 nm visible with specialized laparoscopes. IACUC approved open and laparoscopic surgeries were simulated in New Zealand white rabbits. In the laparoscopic setting, 26 needles were searched for with a standard camera by a surgeon and 26 with an NIR sensitive laparoscope. The surgeon was blinded to needle location. In the open laparotomy setting, 26 needles were searched for with standard light and 26 were searched for with a UV light. Control needles not located within the maximum 300 s were searched with the assistance of the corresponding NIR or UV light. Time to identification was evaluated for statistical significance, p<.05.
Results:All 52 dual dye coated needles searched utilizing the NIR camera (n=26) or UV light (n=26) were located within 300 s. 9 needles in both control settings were unable to be located within 300 s (p=0.0006). The mean time to locate control needles in the open surgery and laparoscopic surgery was statistically 2-3x longer than the time to localization utilizing the dye as an adjunct (p=.0027 for open, p<.001 for laparoscopic, Table 1). Overall the dual dye resulted in greater reducuction in time required to locate the needles in laparoscopic surgery compared to open surgery (p=.0006).
Conclusion:The incorporation of a dual-dye coating on surgical needles shows potential to improve the efficiency of locating RFB and may minimize the need to convert a MIS procedure to an open surgery. Although a benefit was quantified for open surgery the greatest benefit was observed in MIS. Dual-dye coating of surgical needles has potential to decrease the time to localize lost surgical needles and may reduce the risk of RFB.
