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Minimally invasive platforms with built-in fluorescence imaging systems have facilitated the widespread implementation of fluorescence guided surgery. The use of fluorescent dyes, such as indocyanine green, have a wide range of applications in gynecologic oncology and have improved the accuracy of lymphatic mapping and identification of sentinel lymph nodes. However, near infrared imaging systems for open surgeries lack portability and mobility due to size and connections of cables and/or mechanical arms between the handheld component and the image processor/monitor, or even because of the need for a connection to the electric power supply.
Given that current guidelines for the management of early stage cervical cancer recommend the open abdominal approach and the aforementioned issues for the fluorescence imaging systems currently available on the market, we conceptualized our homemade device, Easy Light, as a low cost user friendly system for targeted procedures in open surgeries. In brief, this device is an open field handheld wireless fluorescence imaging system for real time visualization of fluorescence in smartphones and tablets that are accessible to many health professionals. The handheld system is a rechargeable device responsible for excitation of the operative field with infrared lighting and for capturing the fluorescence emitted by fluorescent dye, visualized via wi-fi on smartphones and tablets using pre-installed application software (ie, mobile app) (Figure 1).
We next focused our efforts on developing a handheld prototype that could avoid physical connections. Electric and electronic parts were acquired from online markets and assembled into a pistol shaped case. Near infrared excitation was provided with high power light emitting diodes with a lens arranged in a circular way around a wi-fi micro-camera equipped with optical filters. A rechargeable battery was also added to allow up to 6 hours of continuous use. Proof of concept tests were first developed as preclinical experiments, injecting an indocyanine green solution into fresh chicken wings (Figure 2). Thereafter, we performed ex vivo evaluations of fresh surgical specimens removed during robotic surgeries (online supplemental picture 1). Finally, we also developed an early feasibility study (NCT05004623) to evaluate the functionality of our device in a clinical setting, and also to guide future adjustments and improvements. Intraoperative detection of at least one sentinel lymph node was achievable in all five patients recruited to participate (online supplemental video 1), with bilateral detection in two patients (Figure 3).
We consider that it is important to report this innovative device that may help to disseminate the use of fluorescence lighting for targeted procedures in medicine. At this point, we have already filed a patent in Brazil (BR 10 2021 014051 8) and we are adding improvements to our prototype to initiate a manufacturing process. Finally, we hope our approach may serve as motivation to increase the involvement of surgeons in the process of producing surgical innovations and medical devices.
Patient consent for publication
The study protocol was reviewed by the Ethics Research Committee of IMIP-Instituto de Medicina Integral Professor Fernando Figueira (Reference No CAAE 45814621.5.0000.5201, acceptance protocol No 4.735.768; May 26, 2021) and registered on ClinicalTrials.gov (NCT05004623).
We acknowledge Professor Francisco de AC Barbosa for providing us with the first bottles of indocyanine green that allowed us to start our initial experiments, and Professor Romulo AV Silva for designing an initial pistol shaped case for our device. We also thank Dr Mário R Martins for supporting us during the ex vivo examinations of the fresh surgical specimens removed via minimally invasive robotic surgery, and Dr Vandré CG Carneiro and Dr Diógenes FS Fontão for helping us with patient recruitment during our early feasibility study. Thanks also to residents in general surgery from the Instituto de Medicina Integral Professor Fernando Figueira for helping us with data collection.
Presented at Some data from this study were presented as an oral presentation during the XV Congress of the Brazilian Society of Surgical Oncology (virtual meeting, November 17-20, 2021).
Contributors Study concept and design: all authors, mainly TPB. Device physical set-up and optoelectronics tests: AD. Acquisition of the data: all authors, mainly TPB. Analysis and interpretation of the data: TPB. Drafting of the manuscript: TPB. Critical revision of the manuscript for important intellectual content: ASLG and AD. Administrative support: TPB. Material support: all authors, mainly TPB. Study supervision: TPB and ASLG.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial, or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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