Review of Techniques to Achieve Optical Surface Cleanliness and Their Potential Application to Surgical Endoscopes

Miniature fluorescence sensor for quantitative detection of brain tumour

Fluorescence-guided surgery has emerged as a vital tool for tumour resection procedures. As well as intraoperative tumour visualisation, 5-ALA-induced PpIX provides an avenue for quantitative tumour identification based on ratiometric fluorescence measurement. To this end, fluorescence imaging and fibre-based probes have enabled more precise demarcation between the cancerous and healthy tissues. These sensing approaches, which rely on collecting the fluorescence light from the tumour resection site and its "remote" spectral sensing, introduce challenges associated with optical losses. In this work, we demonstrate the viability of tumour detection at the resection site using a miniature fluorescence measurement system. Unlike the current bulky systems, which necessitate remote measurement, we have adopted a millimetre-sized spectral sensor chip for quantitative fluorescence measurements. A reliable measurement at the resection site requires a stable optical window between the tissue and the optoelectronic system. This is achieved using an antifouling diamond window, which provides stable optical transparency. The system achieved a sensitivity of 92.3% and specificity of 98.3% in detecting a surrogate tumour at a resolution of 1 × 1 mm2. As well as addressing losses associated with collecting and coupling fluorescence light in the current 'remote' sensing approaches, the small size of the system introduced in this work paves the way for its direct integration with the tumour resection tools with the aim of more accurate interoperative tumour identification.

A Low-cost 3D Printed Telescopic Sleeve: A Technical Note

Background: Endoscopic nasal surgery is often a tedious process due to repeated removal of the Hopkins rod telescope from the nasal cavity for manual defogging of the tip due to the presence of blood, smoke, and secretions. Objective: To design and print a 3-dimensional (3D) low-cost telescopic sleeve to allow the defogging solution to clean the rigid telescope tip without removing it from the nasal cavity. In addition, the sleeve must also act as a conduit for suction and irrigation to provide a clear surgical field view intraoperatively. Results and conclusion: A 3D printed low-cost telescopic sleeve, when used in conjunction with other add-ons, can be a helpful and cost-effective adjunct during endoscopic nasal surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03281-0.

Laser-Enabled Surface Treatment of Disposable Endoscope Lens with Superior Antifouling and Optical Properties

Endoscopes are ubiquitous in minimally invasive or keyhole surgeries globally. However, frequent removal of endoscopes from the patient's body due to the lens contaminations results in undesirable consequences. Therefore, a cost-effective process chain to fabricate thermoplastic-based endoscope lenses with superior antifouling and optical properties is proposed in this research. Such multifunctional surface response was achieved by lubricant impregnation of nanostructures. Two types of topographies were produced by femtosecond laser processing of metallic molds, especially to produce single-tier laser-induced periodic surface structures (LIPSS) and two-tier multiscale structures (MS). Then, these two LIPSS and MS masters were used to replicate them onto two thermoplastic substrates, namely polycarbonate and cyclic olefin copolymer, by using hot embossing. Finally, the LIPSS and MS surfaces of the replicas were infiltrated by silicone oils to prepare lubricant-impregnated surfaces (LIS). Droplet sliding tests revealed that the durability of the as-prepared LIS improved with the increase of the lubricant viscosity. Moreover, the single-tier LIPSS replicas exhibited longer-lasting lubricant conservation properties than the MS ones. Also, LIPSS-LIS replicas demonstrated an excellent optical transparency, better than the MS-LIS ones, and almost match the performance of the reference polished ones. Furthermore, the LIPSS-LIS treatment led to superior antifouling characteristics, i.e., regarding fogging, blood adhesion, protein adsorption, and microalgae attachment, and thus demonstrated its high suitability for treating endoscopic lenses. Finally, a proof-of-concept LIPSS-LIS treatment of endoscope lenses was conducted that confirmed their superior multifunctional response.

Stop the Smudge: A Novel Solution to Loss of Vision During Laparoscopic Colorectal Surgery

BACKGROUND

An obscured vision of surgical field during laparoscopic surgery is inconvenient. Several temporary methods were described as solutions to loss of vision, and common practice is scope removal, cleaning, and heating. A lately developed and introduced device claims continuous clear vision during laparoscopic surgery. This study aims to present our initial experience with the device during laparoscopic colorectal surgery.

MATERIALS AND METHODS

We have included medical records of all patients scheduled for laparoscopic colorectal surgery with the device between March and August 2021 at Cleveland Clinic. Patient demographics, surgery type and time, the number of loss of vision events were recorded.

RESULTS

Fifteen patients underwent laparoscopic colorectal surgery during the study period. The median age was 42 (range: 25 to 86) years, and 10 (66%) were female. The median surgery time was 127 (range: 67 to 240) minutes, and the median loss of vision event number was 3 (1 to 6) per surgery. There was no need for laparoscope removal during any of the surgeries. All surgeries were completed without any intraoperative complications.

CONCLUSION

The novel system, provides clear vision during laparoscopic colorectal surgery with no need of scope removal for loss of vision events. The system provides removal of particulate gathering on the tip of the scope.

Utility of Nasal Access Guides in Endoscopic Endonasal Skull Base Surgery: Assessment of Use during Cadaveric Dissection and Workflow Analysis in Surgery

Background  A nasal access guide (NAG) for endoscopic endonasal approaches (EEAs) to the skull-base has been developed and approved for clinical use but its utility has not been formally investigated. Objective  The study aims to assess the effect of a NAG on endoscopic visualization during cadaveric dissection and to perform a workflow analysis with process-based performance measures in the operating room and their effect on clinical outcomes. Methods  Skull-base course participants were observed during hands-on cadaveric dissection with and without NAG. Instances of endoscope withdrawal for lens cleaning and inadequate visualization due to lens soiling were tabulated. Participants completed a Likert-scale survey examining the NAG utility and provided an overall grading. Surgical workflow and process-based performance on patients undergoing EEA to the skull-base was analyzed. Passage of powered and dissecting instruments, removal of endoscopes for cleaning, and dislodgment or migration of the device were reviewed. Postoperative assessments included mucosal trauma and synechiae formation. Results  Instances of endoscope soiling and manual cleaning were significantly reduced by 40% and 61% with the NAG during cadaveric dissection. The overall grading of the device was 2.75/3. Surgical workflow was observed in 35 patients. Average number of passes of endoscopes, instruments, and powered tools during a 10-minute observation period were 3,17, and 5 during the surgical approach, and 3, 18, and 1 during tumor dissection. Dislodgement of the device occurred in 25.7% and migration of the device in 2.8% of cases. Postoperative synechiae, exposed cartilage or septal perforation was not observed in follow up. Conclusion  NAG can significantly reduce inadequate visualization during EEA to the skull-base and has the potential to reduce instances of nasal trauma. Participants assessed its overall utility as being "excellent."

Effectiveness of oolong tea and simethicone solution for lens cleansing during colonoscopy: A double-blinded randomized study

BACKGROUND AND AIMS

water is an imperfect agent for lens cleansing during endoscopy due to its incompetence to clean hydrophobic dirt, whereas amphiphilic surfactants have the potential to overcome the limitation of water. The trial was aimed to evaluate the cleansing effectiveness of 2 typical surfactants (simethicone solution and oolong tea) for colonoscopic lens.

METHODS

Oolong tea (O-), low concentration simethicone solution (S1-), high concentration simethicone solution (S2-) and distilled water (D-) were used as washing solutions for colonoscopic lens. Study I: The tip of the colonoscope was immersed in lard oil in order to simulate the blur, and photographs were taken toward a standard colonoscopy image in-vitro pre- and post- each cleansing procedure. The blurred areas of each image were quantified and compared. Study II: 395 consecutive patients who were due to colonoscopy examination were enrolled and randomized into O-, S2-, D-group. The volume of washing solution used and cleansing level during the examination procedure, adenoma and polyp detected per colonoscopy, insertion time and withdraw time were analyzed.

RESULTS

Study I: There were no differences in 4 groups for the blurred areas on images before lens cleansing. The blurred areas after lens cleansing were significantly smaller in 3 groups (O- 8.47 ± 20.91 vs S1- 13.06 ± 10.71 vs S2- 6.76 ± 8.49 vs D- 38.24 ± 29.69, P < .05) than water. The decline range of blurred areas after lens cleansing in oolong tea, low concentration simethicone solution, high concentration simethicone solution groups were significantly higher than that in distilled water group (O- 87.35 ± 20.81 vs S1- 78.12 ± 19.24 vs S2- 89.57 ± 8.50 vs D- 53.39 ± 28.45, P < .05). Study II: The volume of washing solution used in S2-group was significantly smaller than that in O-group and D-group. The cleansing level of the colonoscopic lens of O-group was significantly superior than that of S2-group and D-group.

CONCLUSIONS

The in-vitro test showed oolong tea and simethicone solution can effectively cleans the colonoscopic lens. The clinical trial demonstrated that oolong tea instead of water is effective to provide better visualization during colonoscopy.Registration: Chictr.org.cn No: ChiCTR1900025606.

Evaluation of the safety and efficacy of suction-tip forceps, a new tool for laparoscopic surgery, for gastric cancer

INTRODUCTION

Laparoscopic surgery is a minimally invasive surgery; however, obstacles to its functional optimization remain. Surgical ports can accommodate only one instrument at a time so complex exchange manipulations are necessary during surgery which increases operation times and patient risk. We developed a new laparoscopic instrument that functions as both forceps and a suction tube, which renders intraoperative tool exchange unnecessary. This pilot study was undertaken to evaluate the safety and efficacy of this novel dual-function device in laparoscopic surgery for gastric cancer.

METHODS

This single-center pilot study assessed patient safety during and after laparoscopic distal gastrectomy for gastric cancer with the suction-forceps using intraoperative video and clinical follow-up, respectively. To evaluate instrument efficacy, we measured the time interval between the start of any bleeding and the start of aspiration ("suction access time") and compared this time with that of a conventional surgical setup.

RESULTS

In total 15 patients participated, with all procedures being successful. No excess tissue damage occurred during surgery. Suction access time was significantly shorter in cases of bleeding when the suction-tip forceps were used for aspiration (2.01 seconds) compared to an ordinary suction tube (12.5 seconds; P < .01).

CONCLUSION

These findings suggest that our new suction-tip forceps are a useful, safe, and efficacious operative tool. This surgical innovation may considerably simplify gastric laparoscopic surgery. This pilot study was registered with Japan Clinical Trial Registration on 22 June 2017 (registration number: UMIN000027879).

Polyolefin-Supported Hydrogels for Selective Cleaning Treatments of Paintings

Surface decontamination is of general concern in many technical fields including optics, electronics, medical environments, as well as art conservation. In this respect, we developed thin copolymer networks covalently bonded to flexible polyethylene (PE) sheets for hydrogel-based cleaning of varnished paintings. The syntheses of acrylates and methacrylates of the surfactants Triton X-100, Brij 35, and Ecosurf EH-3 or EH-9 and their incorporation into copolymers with acrylamide (PAM) and N-(4-benzoylphenyl)acrylamide are reported. Photocrosslinked polymer networks were prepared from these copolymers on corona-treated PE sheets, which can be swollen with aqueous solution to form hydrogel layers. The cleaning efficacy of these PE-PAM hydrogel systems, when swollen with appropriate cleaning solutions, was evaluated on painting surfaces in dependence of the PAM copolymer composition and degree of crosslinking. Specifically, soil and varnish removal and varnish surface solubilization were assessed on mock-ups as well as on paintings, indicating that even surfactant-free cleaning solutions were effective.