Effectiveness of computer-assisted virtual planning, cutting guides and pre-engineered plates on outcomes in mandible fibular free flap reconstructions: a systematic review protocol.

OBJECTIVE: The objective of this review is to synthesize the best available evidence on the outcomes of mandibular fibular free flap (MFFF) reconstructions using computer-assisted techniques versus traditional freehand techniques. INTRODUCTION: Fibular free flaps are the most commonly used free flap for mandible reconstruction and are considered best practice for mandible reconstructions following resection of head and neck cancers. There are several reported advantages of computer-assisted MFFF reconstructions, including increased accuracy, decreased operation time, decreased ischemia time, decreased overall cost and improved patient outcomes. It is important to assess the advantages and potential harms of these techniques in a systematic review. INCLUSION CRITERIA: Eligible studies will consider patients of all ages undergoing MFFF reconstruction. Studies will compare computer-assisted techniques to traditional freehand techniques for the primary outcomes of flap failure, patient-reported outcomes and bony resection margin status. Studies published in English from 2008 will be included. Experimental, quasi-experimental, prospective and retrospective cohort, case-control and analytical cross-sectional studies will be considered. METHODS: MEDLINE, Embase, Scopus and the Cochrane Central Register of Controlled Trials will be searched. Gray literature sources will include Google Scholar and the World Health Organization International Clinical Trials Registry Platform. Two independent reviewers will screen titles and abstracts, assess full-text papers against the inclusion criteria, evaluate methodological quality using standardized critical appraisal instruments and extract data using a customized form. If possible, data will be pooled for statistical meta-analysis, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings will be presented.

Predictive value of computed tomography in identifying extracapsular spread of cervical lymph node metastases in p16 positive oropharyngeal squamous cell carcinoma.

BACKGROUND: Extracapsular spread (ECS) of lymph node metastases is associated with poor prognosis and is an indication for adjuvant chemoradiotherapy. Accurately identifying ECS using imaging may allow us to recommend primary chemoradiotherapy to avoid trimodality treatment. We investigated the accuracy of staging CT in diagnosing ECS in P16 + oropharyngeal squamous cell carcinoma (OPSCC). METHODS: Patients with pathologically determined cervical nodal metastases from P16 + OPSCC were included. Two blinded radiologists scored images to predict the presence of ECS in comparison to histopathology. RESULTS: Eighty patients with a total of 91 specimens were evaluated. Pathologic ECS was identified in 53.8% of the patients. Sensitivity and specificity of CT for the two observers were 56.5% and 60.9%, and 73.3% and 66.7%, respectively. The presence of perinodal stranding was found to be significantly associated with pathological ECS. CONCLUSION: Computed tomography displays consistently high specificity, which may be used to rule out the presence of extracapsular spread in cervical nodal metastases of P16 + oropharyngeal squamous cell carcinoma.

Frailty in geriatric head and neck cancer: A contemporary review.

OBJECTIVE: To provide a summary of the current frailty literature relating to head and neck cancer. DATA SOURCES: Ovid MEDLINE, PubMed, Google Scholar. METHODS: A comprehensive review of the literature was performed from 2000 to 2017 using key words frailty, elderly, geriatric, surgery, otolaryngology, head and neck cancer. RESULTS: The aging population has led to an increased diagnosis of head and neck cancer in elderly patients. The prevalence of comorbidities, disabilities, geriatric syndromes and social issues can make treatment planning and management in this population challenging. Chronological age alone may not be the optimal approach to guiding treatment decisions, as there is marked heterogeneity amongst this age group. Individualization of treatment can be achieved by assessing for the presence of frailty, which has growing evidence as an important marker of health status in geriatric oncology. Frailty is a complex geriatric syndrome characterized by a state of increased vulnerability to stressors and is associated with morbidity, mortality, and treatment toxicity. Screening for frailty may provide an efficient method to identify those who would benefit from further assessment or pretreatment optimization, and to provide prognostic information to assist clinicians and patients in formulating the most ideal treatment plan for the elderly individual with head and neck cancer. CONCLUSIONS: Frailty has emerged as an important concept in geriatric oncology, with wide significance in head and neck cancer. Incorporating frailty assessments into clinical practice may provide otolaryngologists pertinent information regarding health status and outcomes leading to optimal care of the elderly cancer patient. Laryngoscope, 128:E416-E424, 2018.

Sinus Penetration of a Pulsating Device Versus the Classic Squeeze Bottle in Cadavers Undergoing Sinus Surgery.

OBJECTIVES: Nasal irrigation is standard in the management of chronic rhinosinusitis both before and after surgical intervention. Numerous irrigation devices are commercially available. The aim of this study was to compare the efficacy of a handheld pulse irrigation device against the gold standard manual squeeze bottle after endoscopic sinus surgery (ESS). METHODS: Five cadaveric specimens were prepared with video visualization ports into each sinus. Endoscopic sinus surgery was performed on each cadaver from minimal to maximal dissection. Sinuses were irrigated with fluorescein solution using both devices following each dissection. The irrigations were video recorded. A blinded independent observer scored each irrigation according to a defined scale. RESULTS: Comparison of the 2 devices using an intraclass correlation coefficient (ICC = 0.39) showed the 2 systems differed. Observation of individual sinuses showed the squeeze bottle consistently provided greater irrigation in the maxillary (P < .006), frontal (P < .0001), and sphenoid (P < .0001) sinuses. Pulse irrigation improved only in the maxillary sinus following ESS. CONCLUSION: The squeeze bottle consistently demonstrated superior irrigation in both native and operated conditions. Interestingly, saline penetration was not significantly improved after opening of the frontal and sphenoid sinuses. This is likely due to decreased backpressure in the nasal passage after opening the sinus cavities.

The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection.

BACKGROUND: Bacteria and fungi are believed to influence mucosal inflammation in chronic rhinosinusitis (CRS). However their presence and relationship to disease is debated. This study used multiple detection methods to compare microbial diversity and microbial abundance in healthy and diseased sinonasal mucosa. The utility of contemporary detection methods is also examined. METHODS: Sinonasal mucosa was analyzed from 38 CRS and 6 controls. Bacterial and fungal analysis was performed using conventional culture, molecular diagnostics (polymerase chain reaction coupled with electrospray ionization time-of-flight mass spectrometry) and fluorescence in situ hybridization. RESULTS: Microbes were detected in all samples, including controls, and were often polymicrobial. 33 different bacterial species were detected in CRS, 5 in control patients, with frequent recovery of anaerobes. Staphylococcus aureus and Propionibacterium acnes were the most common organisms in CRS and controls, respectively. Using a model organism, FISH had a sensitivity of 78%, and a specificity of 93%. Many species were detected in both CRS and controls however, microbial abundance was associated with disease manifestation. CONCLUSIONS: This study highlights some cornerstones of microbial variations in healthy and diseased paranasal sinuses. Whilst the healthy sinus is clearly not sterile, it appears prevalence and abundance of organisms is critical in determining disease. Evidence from high-sensitivity techniques, limits the role of fungi in CRS to a small group of patients. Comparison with molecular analysis suggests that the detection threshold of FISH and culture is related to organism abundance and, furthermore, culture tends to select for rapidly growing organisms.

Bacterial-induced epithelial damage promotes fungal biofilm formation in a sheep model of sinusitis.

BACKGROUND: Fungal biofilms have been discovered in chronic rhinosinusitis (CRS) patients, but factors contributing to their establishment are obscure. A recent animal study showed bacterial co-inoculation was required. We examine the role of 4 bacterial species and a cilia toxin on fungal biofilm formation in a sheep sinusitis model. The importance of epithelial integrity on fungal biofilm formation is also examined. METHODS: Forty-eight frontal sinuses were inoculated with Aspergillus fumigatus alone, with 1 of 4 bacteria, or a cilia toxin. Bacterial and fungal biofilm was determined using confocal scanning laser microscopy. Inflammation and cilia integrity were assessed using light microscopy and transmission electron microscopy, respectively. RESULTS: No fungal biofilm formed when inoculated alone. Florid fungal biofilm developed in more than 75% of sinuses associated with bacterial biofilm of all species, except Haemophilus influenzae, which failed to establish bacterial biofilm. Fungal biofilm also established in association with cilia toxin. Significant cilial damage was incited by all bacterial biofilms and cilia toxin, and was associated with fungal proliferation. Fungal biofilm formation did not significantly increase mucosal inflammation or epithelial damage over that caused by the bacteria or cilia toxin alone. CONCLUSION: Bacterial biofilms cause sinonasal mucosal inflammation and epithelial injury, which provides conditions appropriate for fungal biofilm proliferation. The role of cilia in sinonasal mucosal defense against fungal organisms has been demonstrated. Without such an insult, fungal biofilms fail to proliferate in occluded sinuses. Improving cilial recovery postoperatively and treating bacterial biofilms may be key factors in reducing recalcitrance in allergic fungal rhinosinusitis patients.

Role of bacterial and fungal biofilms in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a very common condition that remains poorly understood from a pathogenic standpoint. Recent interest has been sparked by a potential role for biofilms in this process, with a significant body of evidence implicating them in inciting sinonasal inflammation. Biofilms are clearly present on the sinus mucosa of CRS patients, and their presence there is associated with severe disease characteristics and surgical recalcitrance. We are beginning to understand the importance of the species within these biofilms, but there may be other as-yet-unidentified factors at play in influencing disease outcomes. Recent exciting research has emerged documenting the immune response to the presence of biofilms-research that will ultimately solidify the nature and extent of the contribution of biofilms in CRS pathogenesis. Future research should focus on evidence-based antibiofilm treatments with reference to efficacy and timing of treatment.

Quantitative analysis of in vivo mucosal bacterial biofilms.

BACKGROUND: Quantitative assays of mucosal biofilms on ex vivo samples are challenging using the currently applied specialized microscopic techniques to identify them. The COMSTAT2 computer program has been applied to in vitro biofilm models for quantifying biofilm structures seen on confocal scanning laser microscopy (CSLM). The aim of this study was to quantify Staphylococcus aureus (S. aureus) biofilms seen via CSLM on ex situ samples of sinonasal mucosa, using the COMSTAT2 program. METHODS: S. aureus biofilms were grown in frontal sinuses of 4 merino sheep as per a previously standardized sheep sinusitis model for biofilms. Two sinonasal mucosal samples, 10 mm × 10 mm in size, from each of the 2 sinuses of the 4 sheep were analyzed for biofilm presence with Baclight stain and CSLM. Two random image stacks of mucosa with S. aureus biofilm were recorded from each sample, and analyzed using COMSTAT2 software that translates image stacks into a simplified 3-dimensional matrix of biofilm mass by eliminating surrounding host tissue. Three independent observers analyzed images using COMSTAT2 and 3 repeated rounds of analyses were done to calculate biofilm biomass. RESULTS: The COMSTAT2 application uses an observer-dependent threshold setting to translate CSLM biofilm images into a simplified 3-dimensional output for quantitative analysis. Intraclass correlation coefficient (ICC) between thresholds set by the 3 observers for each image stacks was 0.59 (p = 0.0003). Threshold values set at different points of time by a single observer also showed significant correlation as seen by ICC of 0.80 (p < 0.001). CONCLUSION: COMSTAT2 can be applied to quantify and study the complex 3-dimensional biofilm structures that are recorded via CSLM on mucosal tissue like the sinonasal mucosa.

The efficacy of hemostatic techniques in the sheep model of carotid artery injury.

BACKGROUND: The most dramatic complication in endonasal surgery is inadvertent injury to the internal carotid artery (ICA) with massive bleeding. Nasal packing is the favored technique for control; however, this often causes complete carotid occlusion or carotid stenosis, contributing to the morbidity and mortality of the patient. The aim of this study is to compare the efficacy of endoscopically applied hemostatic techniques that maintain vascular flow in an animal model of carotid artery injury. METHODS: A total of 20 sheep underwent ICA dissection/isolation followed by the placement of the artery within a modified "sinus model otorhino neuro trainer" (SIMONT) model. A standardized 4-mm carotid artery injury was created endoscopically. Randomization of sheep to receive 1 of 5 hemostatic techniques was performed (Floseal, oxidized regenerated cellulose, Chitosan gel, muscle patch, or the U-Clip anastomotic device). Specific outcome measures were time to hemostasis, duration of time mean arterial pressure (MAP) was >55 mmHg, blood loss, and survival time. RESULTS: Muscle patch hemostasis and the U-Clip anastomotic device were significantly more effective at achieving primary hemostasis rapidly, reducing total blood loss, and increasing survival time and time MAP was >55 mmHg more than Floseal, oxidized regenerated cellulose, and Chitosan gel (p < 0.05). Additionally, all muscle patch-treated and U-Clip device-treated sheep achieved primary hemostasis and reached the endpoint of observation, while maintaining vascular patency. Floseal and oxidized regenerated cellulose failed to achieve hemostasis in any animal, with all animals exsanguinating prematurely. CONCLUSION: In the sheep model of endoscopic ICA injury, the muscle patch and U-Clip anastomotic device significantly improved survival, reduced blood loss, and achieved primary hemostasis while maintaining vascular patency.

A sheep model to investigate the role of fungal biofilms in sinusitis: fungal and bacterial synergy.

BACKGROUND: The role of fungi in the spectrum of chronic rhinosinusitis (CRS) is poorly understood. Fungal biofilms have recently been discovered in CRS patients. We have developed an animal model for the investigation of sinonasal fungal biofilms. The role of type I hypersensitivity and pathogenic bacteria is presented. METHODS: Thirty sheep were sensitized with fungal antigens-Aspergillus fumigatus and Alternaria alternata, or control. Endoscopic surgery was performed to expose both frontal sinus ostia-1 was occluded. Fungi with or without Staphylococcus aureus were inoculated into the sinus. Skin-prick tests assessed for fungal allergy. Fungal and S. aureus biofilms, histology, and culture rates were assessed. RESULTS: Forty-five percent of experimental sheep were sensitized to fungal antigen. Only 1 sinus inoculated with fungus developed minimal fungal biofilm. Eighty percent developed fungal biofilm when S. aureus was co-inoculated. The presence of hypersensitivity to fungus was not related to fungal biofilm development. CONCLUSION: Significant fungal biofilm only occurred when S. aureus was the co-inoculum. Hypersensitivity was not requisite. The relationship of S. aureus to fungal biofilms is of great clinical interest. Fungi may be opportunistic pathogens that simply require inflamed mucosa with weakened innate defenses; alternatively, a cross-kingdom synergy could be contributing to fungal proliferation.

Long-term symptom relief from primary hyperparathyroidism following minimally invasive parathyroidectomy.

BACKGROUND: The affect of the surgical approach for primary hyperparathyroidism (1HPT) on long-term symptom relief has not been studied. This study compares the long-term relief of symptoms assessed by the Parathyroidectomy Assessment of Symptoms (PAS) score in patients undergoing bilateral neck exploration (BNE) and minimally invasive parathyroidectomy (MIP). METHODS: In this case-control study, patients with 1HPT who had followed a protocol to assess symptoms before and after parathyroid surgery between 1999 and 2008 were contacted by letter and had blood taken to assess calcium, ionized calcium, and parathyroid hormone (PTH). The main aim was to assess symptoms at long-term follow-up using the PAS score. The incidence of persistent or recurrent 1HPT at long-term follow-up after MIP and BNE was also compared. RESULTS: Two hundred and forty-six patients underwent parathyroid surgery and 142 responded to our correspondence, of which 64 underwent MIP and 78 BNE. Follow-up after BNE was longer than MIP (61 vs. 41 months). At long-term follow-up, the mean PAS score fell by 125 and 175 in the MIP and BNE groups, respectively. There was no statistically significant difference in the decline of the PAS score between the MIP and BNE groups. Six patients developed persistent or recurrent 1HPT following MIP compared to three after BNE; this difference was not statistically significant. CONCLUSIONS: This study is the first to report on long-term symptom relief from 1HPT after MIP, and demonstrates that both MIP and BNE can achieve this. In order to establish whether the long-term outcomes from these procedures are equivalent, further adequately powered studies are required.

In vitro-in vivo correlations for drugs eliminated by glucuronidation: investigations with the model substrate zidovudine.

AIMS: To investigate the effects of incubation conditions on the kinetic constants for zidovudine (AZT) glucuronidation by human liver microsomes, and whether microsomal intrinsic clearance (CLint) derived for the various conditions predicted hepatic AZT clearance by glucuronidation (CLH) in vivo. METHODS: The effects of incubation constituents, particularly buffer type (phosphate, Tris) and activators (Brij58, alamethacin, UDP-N-acetylglucosamine (UDP-NAcG)), on the kinetics of AZT glucuronidation by human liver microsomes was investigated. AZT glucuronide (AZTG) formation by microsomal incubations was quantified by h.p.l.c. Microsomal CLint values determined for the various experimental conditions were extrapolated to a whole organ CLint and these data were used to calculate in vivo CLH using the well-stirred, parallel tube and dispersion models. RESULTS: Mean CLint values for Brij58 activated microsomes in both phosphate (3.66 +/- 1.40 micro l min-1 mg-1, 95% CI 1.92, 5.39) and Tris (3.79 +/- 0.74 micro l min-1 mg-1, 95% CI 2.87, 4.71) buffers were higher (P < 0.05) than the respective values for native microsomes (1.04 +/- 0.42, 95% CI 0.53, 1.56 and 1.37 +/- 0.30 micro l min-1 mg-1, 95% CI 1.00, 1.73). Extrapolation of the microsomal data to a whole organ CLint and substitution of these values in the expressions for the well-stirred, parallel tube and dispersion models underestimated the known in vivo blood AZT clearance by glucuronidation by 6.5- to 23-fold (3.61-12.71 l h-1vs 82 l h-1). There was no significant difference in the CLH predicted by each of the models for each set of conditions. A wide range of incubation constituents and conditions were subsequently investigated to assess their effects on GAZT formation, including alamethacin, UDP-NAcG, MgCl2, d-saccharic acid 1,4-lactone, ATP, GTP, and buffer pH and ionic strength. Of these, only decreasing the phosphate buffer concentration from 0.1 m to 0.02 m for Brij58 activated microsomes substantially increased the rate of GAZT formation, but the extrapolated CLH determined for this condition still underestimated known AZT glucuronidation clearance by more than 4-fold. AZT was shown not to bind nonspecifically to microsomes. Analysis of published data for other glucuronidated drugs confirmed a trend for microsomal CLint to underestimate in vivo CLH. CONCLUSIONS: AZT glucuronidation kinetics by human liver microsomes are markedly dependent on incubation conditions, and there is a need for interlaboratory standardization. Extrapolation of in vitro CLint underestimates in vivo hepatic clearance of drugs eliminated by glucuronidation.