The risk of free flap revision and subsequent medical costs in patients with hypopharyngeal cancer.

BACKGROUND: Few studies have examined the preoperative risks and healthcare costs related to free flap revision in hypopharyngeal cancer (HPC) patients. METHODS: A 20-year retrospective case-control study was conducted using the Chang Gung Research Database, focusing on HPC patients who underwent tumor excision and free flap reconstruction from January 1, 2001, to December 31, 2019. The impacts of clinical variables on the need for re-exploration due to free flap complications were assessed using logistic regression. The direct and indirect effects of these complications on medical costs were evaluated by causal mediation analysis. RESULTS: Among 348 patients studied, 43 (12.4%) developed complications requiring re-exploration. Lower preoperative albumin levels significantly increased the risk of complications (OR 2.45, 95% CI 1.12-5.35), especially in older and previously irradiated patients. Causal mediation analysis revealed that these complications explained 11.4% of the effect on increased hospitalization costs, after controlling for confounders. CONCLUSIONS: Lower preoperative albumin levels in HPC patients are associated with a higher risk of microvascular free flap complications and elevated healthcare costs, underscoring the need for enhanced nutritional support before surgery in this population.

Applicability of Oculomotor Tests for Predicting Central Vestibular Disorder Using Principal Component Analysis.

The videonystagmography oculomotor test battery is considered useful method for diagnosing vertigo. However, its role in diagnosing central vestibular disorder has not been clarified due to variations in interpretation. Patients (n = 103) with vertigo or dizziness symptoms undergoing the oculomotor tests and brain MRI within 1 month were analyzed. Two otology specialists retrospectively interpreted the oculomotor tests, and three neurology and neuroradiology specialists determined whether central lesions were present on brain MRI. Multivariable logistic regression analysis was performed to determine the factors contributing to discordant interpretation between oculomotor tests and brain MRI. Oculomotor tests predicting central lesions were assessed using principal component analysis. The intra- and inter-rater reliability in oculomotor test interpretation was moderate to good. Age > 60 years and multiple comorbidities were significant predictors of a discordant interpretation between MRI and oculomotor tests. Positive neurological symptoms and a higher oculomotor index (according to saccade (vertical axis), smooth pursuit (horizontal axis), and gaze-evoked nystagmus (horizontal/vertical axes) tests) significantly predicted central vestibular disorder in vertigo patients. Caution is required when interpreting the results of the oculomotor test battery for diagnosis of central lesions in older patients, as well as in those with multiple comorbidities.

Association of carotid intima-media thickness with the risk of sudden sensorineural hearing loss.

Cardiovascular factors are associated with the pathophysiological features and risk of sudden sensorineural hearing loss (SSNHL). However, little is known about the link between carotid intima-media thickness (IMT), SSNHL risk, and their respective treatment outcomes. In this study, we retrospectively reviewed 47 SSNHL cases and 33 control subjects from a single medical center and compared their demographic data and clinical characteristics, including their carotid IMT and audiological data. Of the 80 enrolled subjects, the proportion of those with high carotid IMT was greater in the SSNHL group (53.2%) than in the control group (21.2%), with an odds ratio (OR) of 4.22 (95% confidence interval (CI) [1.53-11.61], P = 0.004). Notably, high carotid IMT was more common in female SSNHL patients than females in the control group (54.2% vs. 12.5%; OR, 8.27 (95% CI [1.53-44.62]), P = 0.008), particularly in female patients ≥50 years of age (75% vs. 25%; OR, 9.0 (95% CI [1.27-63.9]), P = 0.032). The multivariate regression analyses showed the association between high carotid IMT and SSNHL with an adjusted OR of 4.655 (95% CI [1.348-16.076], P = 0.015), particularly in female SSNHL patients (adjusted OR, 9.818 (95% CI [1.064-90.587], P = 0.044). The carotid IMT was not associated with the treatment outcomes of SSNHL. Our results indicate that early-stage atherosclerosis may be associated with SSNHL, particularly in female patients more than 50 years old.

Xenobiotic substrate reduces yield of activated sludge in a continuous flow system.

The biomass yield of a continuous flow activated sludge system varied when the system treated influent containing different compositions of biogenic and xenobiotic substrates. Both the biogenic substrate and a test xenobiotic 2,4-dichlorophenoxyacetic acid (2,4-D) were degraded at steady-state activated sludge operations. The true yields, determined from steady-state activated sludge treatment performances, were at the maximum and the minimum when the activated sludge treated the influent of sole biogenic substrate and sole 2,4-D, respectively. The minimum yield was 56% of the maximum. Yield reduction between the maximum and the minimum was proportional to the concentration of 2,4-D in the influent. This trend of yield reduction suited a model that describes the metabolic uncoupling effect of 2,4-D on the sludge's degradation of the substrates. The model function variable was defined as the ratio of 2,4-D to biogenic COD concentrations in the influent.