Antibiotics Affect ROS Production and Fibroblast Migration in an In-vitro Model of Sinonasal Wound Healing.

Introduction: Antibiotics are often administered to patients perioperatively and have been shown to affect ROS production of nasal cells in vitro, but their effect in the setting of active wound healing remains unclear. Reactive oxygen species (ROS) are known to play a significant role in wound healing. This study analyzed a broad array of antibiotics used after sinus surgery to assess their effect on wound healing and ROS production in vitro. It was hypothesized that ROS production would be affected by these antibiotics and there would be a negative relationship between ROS activity and cell migration speed. Methods: Monolayers of primary human nasal epithelial cells (HNEC) and primary fibroblasts were disrupted with a linear wound, treated with 10 different antibiotics or a ROS inhibitor and observed over 36 h in a controlled environment using confocal microscopy. ROS activity and migration speed of the wound edge were measured at regular intervals. The relationship between the two parameters was analyzed using mixed linear modeling. Results: Performing a linear scratch over the cell monolayers produced an immediate increase in ROS production of ~35% compared to unscratched controls in both cell types. Incubation with mitoquinone and the oxazolidinone antibiotic linezolid inhibited ROS activity in both fibroblasts and HNEC in association with slowed fibroblast cell migration (p < 0.05). Fibroblast cell migration was also reduced in the presence of clarithromycin and mupirocin (p < 0.05). A significant correlation was seen between ROS suppression and cell migration rate in fibroblasts for mitoquinone and all antibiotics except for azithromycin and doxycycline, where no clear relationship was seen. Treatments that slowed fibroblast cell migration compared to untreated controls showed a significant correlation with ROS suppression (p < 0.05). Conclusion: Increased ROS production in freshly wounded HNEC and fibroblast cell monolayers was suppressed in the presence of antibiotics, in correlation with reduced fibroblast cell migration. In contrast, HNEC cell migration was not significantly affected by any of the antibiotics tested. This differential effect of antibiotics on fibroblast and HNEC migration might have clinical relevance by reducing adhesion formation without affecting epithelial healing in the postoperative setting.

How I do it: transnasal retraction during transoral robotic oropharyngeal resection.

Collapse of the resection plane presents a frustrating problem during transoral robotic resection, in a situation already typified by limited vision and access for instruments. We present a quick and cost-effective retraction technique to effectively mitigate this issue and increase the ease and reliability of robotic oropharyngeal resection. This technique utilises a simple transnasal apparatus to create greater exposure of the resection plane. A Y-suction catheter is inserted into the oropharynx via the nasal cavity. A silk suture is then used to attach it to the oropharyngeal resection specimen. When pulled from the nasal cavity, this apparatus adds a non-intrusive, tremor-free fixation point that pulls the resected specimen along a unique cephalo-posterior vector. This significantly improves access and vision of the desired dissection plane. The entire process takes approximately 1-2 min per side to properly execute. It can be adapted for various pathologies and subsites of the oropharynx. This transnasal technique is a simple, minimally invasive, and inexpensive method for improving wound tension during transoral oropharyngeal resection.

Transoral robotic surgery using the Medrobotic Flex® system: the Adelaide experience.

Transoral robotic surgery (TORS) has become an accepted treatment option for a variety of benign and malignant pathologies of the head and neck. The Medrobotics Flex® system is a novel single port platform available as an alternative tool to current multiport robotic technology. We present the Adelaide experience with this system thus far. The Medrobotics Flex® system was introduced in Adelaide in January 2017. Patient demographics, pathology, indication for surgery and complications are prospectively recorded for all cases. The first 20 patients are presented in this case series. 11/20 underwent surgery for malignant disease. Of these nine were diagnosed with oropharyngeal squamous cell carcinoma (OPSCC). Histopathology revealed clear margins of primary tumour excision in 8/9 patients. There were no intraoperative complications. In terms of secondary complications, one patient undergoing tonsillectomy for recurrent tonsillitis experienced a secondary haemorrhage at day 13 following operation and one patient undergoing lateral oropharyngectomy for pT3N2b tonsillar SCC sustained an oro-cervical fistula, which settled with conservative management. We have found the Medrobotic Flex® system to be a safe, reliable tool for managing transoral surgery. The range of pathology managed with this platform, as well as the histologic outcomes presented, demonstrates efficacy in the oropharynx and posterior oral cavity for both benign and malignant disease.

Extent of maxillary sinus surgery and its effect on instrument access, irrigation penetration, and disease clearance.

BACKGROUND: Middle meatal antrostomy (MMA) provides limited access to the anteromedial and inferior aspect of the maxillary sinus (MS) often resulting in residual disease and inflammatory burden. Newer extended procedures, such as mega-antrostomy (Mega-A) and extended modified mega-antrostomy (EMMA), have been developed to address this limitation. This study assesses the effect of varying extent of MS surgery on irrigation penetration and access of instrumentation. METHODS: The MS of 5 fresh-frozen cadavers were sequentially dissected. Irrigation was evaluated with a squeeze bottle (SB) in different head positions and using different volumes of fluid. Surgical reach and visualization were examined using common sinus instruments and different angled endoscopes. A disease simulation was also performed to check for residual debris after instrumentation and irrigations. RESULTS: Irrigation penetration improved as antrostomy size increased (p < 0.0001), with a significant difference observed between the extended procedures and MMA. The effect of the volume was significant for SB (p < 0.0001) but head positions appeared irrelevant (p = 0.613). Overall visualization improved for Mega-A and EMMA. A similar trend was seen for the reach of the instruments to all sinus wall subsites. EMMA facilitated the most removal of "sinus disease" in the disease simulation model when compared with both MMA and Mega-A, due to its reach of the anteroinferior aspects of the maxillary sinus. CONCLUSIONS: High-volume irrigation using SB achieved good sinus penetration, irrespective of head position. Extended MS procedures appear to further increase irrigation penetration as well as surgical access.

Deferiprone has anti-inflammatory properties and reduces fibroblast migration in vitro.

Normal wound healing is a highly regulated and coordinated process. However, tissue injury often results in inflammation with excessive scar tissue formation after 40-70% of operations. Here, we evaluated the effect of the iron chelator deferiprone on inflammation and the migration of primary nasal fibroblasts and primary human nasal epithelial cells (HNECs) in vitro. The cytotoxicity of deferiprone was examined by the lactate dehydrogenase assay on primary nasal fibroblasts and air-liquid interface (ALI) cultures of HNECs. Wound closure was observed in scratch assays by using time-lapse confocal scanning laser microscopy. Interleukin-6 (IL-6) and type I and III collagen protein levels were determined by ELISA. Intracellular Reactive Oxygen Species (ROS) activity was measured by utilizing the fluorescent probe H2DCFDA. Deferiprone at 10 mM concentration was non-toxic to primary fibroblasts and HNECs for up to 48 hours application. Deferiprone had significant dose-dependent inhibitory effects on the migration, secreted collagen production and ROS release by primary nasal fibroblasts. Deferiprone blocked Poly (I:C)-induced IL-6 production by HNECs but did not alter their migration in scratch assays. Deferiprone has the potential to limit scar tissue formation and should be considered in future clinical applications.