Neil C.‐W. Tan

The multiplicity of Staphylococcus aureus in chronic rhinosinusitis: correlating surface biofilm and intracellular residence.

The biofilm paradigm of chronic rhinosinusitis (CRS) is increasingly understood to play a key role in the pathophysiology of this disease. The role of intracellular infection of sinonasal epithelial cells has been suggested as a potential reservoir of pathogenic organisms that can lead to recalcitrant disease despite maximal medical and surgical treatment. Could a surface biofilm play a role in allowing intracellular infection to occur, and what are the factors associated with potential intracellular infections? The aim of this study was to investigate these questions.

Intracellular Staphylococcus aureus: the Trojan horse of recalcitrant chronic rhinosinusitis?

Background Despite recent evidence suggesting that Staphylococcus aureus exists within the sinonasal epithelium of chronic rhinosinusitis (CRS) patients, certain questions remain. The intracellular environment may provide a protective niche for pathogenic bacteria to evade host immunity and yet provide a reservoir for reinfection. To date, no studies have examined the impact of this bacterial phenotype; therefore, this study was designed to evaluate the role of intracellular S. aureus on postsurgical outcomes. Methods This study included 51 patients undergoing endoscopic sinus surgery (ESS) for medically-recalcitrant CRS. Sinonasal mucosa harvested at the time of surgery was dually stained with fluorescent molecular probes and imaged using confocal scanning laser microscopy for biofilm and intracellular status. Patients were followed in their early and late postoperative course for evidence of ongoing disease and signs of clinical relapse. Results Intracellular S. aureus was identified in 20 of 51 (39%) patients, and all were associated with surface biofilm. Biofilm alone was found in 16 of 51 (31%) patients and 15 of 51 (29%) patients had no evidence of S. aureus. Intracellular positive patients had a significantly higher risk of late clinical and microbiological relapse (p = 0.014). In this study, biofilm status without coexisting intracellular bacteria did not appear to impact on outcomes. Conclusion Clinical and microbiological relapse of disease following ESS is significantly associated with intracellular S. aureus. Evidence suggests that this disease association is independent to surface biofilm status. Intracellular bacteria should be taken into consideration when designing novel treatment strategies to lessen the chance of reinfection.Despite recent evidence suggesting that Staphylococcus aureus exists within the sinonasal epithelium of chronic rhinosinusitis (CRS) patients, certain questions remain. The intracellular environment may provide a protective niche for pathogenic bacteria to evade host immunity and yet provide a reservoir for reinfection. To date, no studies have examined the impact of this bacterial phenotype; therefore, this study was designed to evaluate the role of intracellular S. aureus on postsurgical outcomes.

Endoscopic Surgery of Skull Base Chordomas

Objective To assess our clinical experience in treating midline intracranial pathology using minimally invasive surgical techniques. Design Retrospective chart review of patients undergoing endoscopic endonasal resection of clival chordomas. Setting Two tertiary referral centers in Australia and New Zealand. Main Outcome Measures Patients were assessed by intraoperative findings (macroscopic resection rate, tumor size, and operative complications) and clinical outcomes (residual disease, postoperative complications, recurrence rate, and mortality). Results Fourteen patients underwent endoscopic resection of clival chordomas (seven primary, seven revision) with a mean follow-up of 41.45 months (3 to 104 months). Macroscopic resection rates were 71% and 29%, respectively. Mean operative time was 386 minutes. Overall cerebrospinal fluid (CSF) leak rate was 3/14 (21%) and, using the nasoseptal flap, it was 0/5 (0%). Two patients developed late recurrence; one died of disease and one was treated with intensity modulated radiation therapy. Overall mortality was 2/14 (14%). Conclusion Endoscopic resection of clival chordomas is a safe and viable alternative to the traditional open approach. The nasoseptal flap is an excellent method of obtaining a watertight skull base closure. Furthermore, this series highlighted the fact that the primary attempt at surgery offers the best chance to achieve a total resection.

Identifying intracellular Staphylococcus aureus in chronic rhinosinusitis: a direct comparison of techniques.

Background The emerging concept of intracellular pathogens such as Staphylococcus aureus playing a role in chronic rhinosinusitis (CRS) has led to the development of numerous imaging techniques for their identification. Traditional methods of bacterial culture are not effective at localizing bacteria to the surface or within tissue samples. The aim of this study was to develop and validate a novel imaging technique using confocal scanning laser microscopy (CSLM) coupled with a fluorescence in situ hybridization (FISH) probe and nucleic acid counterstain (propidium iodide [PI]) that allows for simultaneous analysis of S. aureus intracellular status and surface biofilm within whole mucosal samples. Methods A prospective study was performed including 17 patients undergoing endoscopic sinus surgery for CRS. Tissue samples were analyzed with both CSLM-FISH/PI and immunohistochemistry (IHC) for intracellular S. aureus status. Results Using CSLM-FISH/PI intracellular S. aureus was identified in 9/17 (47%) patients and in 7/17 (39%) using IHC. Surface biofilm can be identified with CSLM-FISH/PI in the same piece of tissue; however, deeper imaging to the submucosa is impossible. IHC showed submucosal bacteria in three patients. Conclusion Both CSLM-FISH/PI and IHC are complementary techniques that can be used to identify intracellular S. aureus. CSLM-FISH/PI allows for the simultaneous detection of intracellular status and surface biofilm within the tissue analyzed. IHC has a role in the identification of intracellular and submucosal S. aureus within these tissues. Additional investigation is required to identify the true pathogenic nature of intracellular organisms as well as any relationship to surface biofilm status.

Association of intracellular Staphylococcus aureus with prognosis in chronic rhinosinusitis

Staphylococcus aureus (S. aureus) has been shown to exist within nasal epithelial cells in chronic rhinosinusitis (CRS) patients. This study investigates the localization of intracellular S. aureus (ICSA) in CRS patients, the associated histopathology changes, and their effect on long‐term postoperative outcomes.

Safety evaluation of a sinus surfactant in an explant-based cytotoxicity assay

Biofilms are associated with clinical relapse following surgery for chronic rhinosinusitis. Encased bacteria are protected from innate immunity and antimicrobial therapy. Surfactants can disperse the biofilm into its planktonic phenotype so that traditional treatments may be effective. The aim of this study was to assess a surfactant for its cytotoxicity profile.

Transillumination-Assisted Maxillary Trephination: Cadaver Validation of a New Technique

INTRODUCTION Endoscopic sinus surgery is performed on patients with chronic rhinosinusitis who have previously failed medical therapy. The maxillary sinus is one of the most commonly affected, and endoscopic access is typically through uncinectomy and middle meatal antrostomy (MMA). Difficulties in reaching the anterior and inferior portions of the sinus have been noted due to limitations of rigid endoscopic equipment. The canine fossa puncture has been suggested as a secondary route of surgical access, and was initially described as a trochared puncture through the canine fossa, superior to the root of the canine tooth, inferior to the infraorbital foramen, medial to the zygomatic buttress, and lateral to the pyriform aperture. Recently, an updated anatomical study has described new landmarks, namely a trephination at the intersection of the midpupillary line and the horizontal line through the floor of the nasal vestibule. Cadaveric studies have shown this to be the optimum position for avoiding damage to the plexuses of the anterior superior alveolar nerve (ASAN) and middle superior alveolar nerve (MSAN), and the potential sequelae of cheek swelling, dental numbness, facial numbness, tingling, and pain. We present a modification of this technique that uses transillumination of the anterior wall of the maxillary sinus to identify the major trunks of the ASAN and MSAN, followed by an accurately drilled trephination to gain surgical access to the sinus, and a cadaveric study to assess nerve injuries in heads that have undergone canine fossa trephination (CFT) using updated anatomical landmarks. Subsequent to this cadaveric study, we tested this method of locating the optimum trephination position in patients who required CFT as part of the operative management of sinus disease.

Prelacrimal approach for nasolacrimal duct excision in the management of lacrimal system tumours

ABSTRACT Purpose: To report a case of a lacrimal sac tumour and describe a prelacrimal approach to the maxillary sinus to excise the nasolacrimal duct in its management. To our knowledge, this approach has not been adapted to remove the nasolacrimal duct for the management of pathological processes involving the nasolacrimal system. Methods: A 58-year-old female patient presented with a 6-month history of epiphora. A lacrimal sac mass was identified, and a biopsy revealed squamous cell carcinoma. Surgical excision was performed via a combined external and endoscopic prelacrimal approach. Results: A prelacrimal approach to the maxillary sinus to excise the nasolacrimal duct in combination with an external approach facilitated an en-bloc excision of the nasolacrimal apparatus. This allowed preservation on the entire inferior turbinate following reconstitution of the lateral nasal wall at the completion of the procedure. Conclusion: The endoscopic endonasal prelacrimal approach to the maxillary sinus is a useful method to approach and excise the nasolacrimal duct in the management of nasolacrimal pathology.

Partial resection of the middle turbinate during endoscopic sinus surgery for chronic rhinosinusitis does not lead to an increased risk of empty nose syndrome: a cohort study of a tertiary practice: PMTR during ESS for CRS and the risk of ENS

The treatment of the middle turbinate (MT) during endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) remains a contentious issue with arguments both for and against its resection. The purpose of this study was to examine the clinical impact of partial MT resection (PMTR) during ESS, paying particular attention to the risk of developing empty nose syndrome (ENS) and alteration to olfaction.

Improvement in Olfaction following Modified Endoscopic Lothrop Procedure

Objectives: The Modified Endoscopic Lothrop Procedure (MELP) is performed for severe cases of chronic rhinosinusitis (CRS) refractory to standard medical and surgical treatments. It involves creating a wide neo-ostium connecting both frontal ostia and the removal of bone between the frontal beak and the olfactory fossa. The posterior margins of dissection are the fibers of the first olfactory neurons; therefore, this procedure may influence sense of smell. The aim of this study was to assess the objective sense of smell pre- and post-MELP. Methods: A prospective study of 20 patients with severe recalcitrant CRS undergoing MELP. Preoperative and postoperative sense of smell was assessed with the University of Pennsylvania Smell Inventory Test (UPSIT). Results: Mean UPSIT scores improved from 19.8 to 25.5 following MELP (p=0.0277, t-test). The greatest improvement was seen in patients with a poor sense of smell preoperatively; mean UPSIT 11.6 to 22.4 (p=0.0026, t-test). In patients with a good sense of smell preoperatively, this was not affected negatively by MELP; mean UPSIT 29.25 to 29 (p=0.9351, t-test). Conclusions: Modified Endoscopic Lothrop Procedure can have a beneficial effect on postoperative sense of smell, and importantly, the operation does not cause any disturbance in sense of smell following surgery in this cohort of patients.