Utility of Routine Spirometry Measures for Surveillance of Idiopathic Subglottic Stenosis.

Importance: Because of the recurrent nature of idiopathic subglottic stenosis, routine follow-up is necessary for monitoring progression of stenosis. However, no easily accessible, standardized objective measure exists to monitor disease progression. Objective: To determine whether peak expiratory flow (PEF) can be used as a reliable and easily accessible biometric indicator of disease progression relative to other validated spirometry measures in patients with idiopathic subglottic stenosis. Design, Setting, and Participants: Prospectively collected data on PEF, expiratory disproportion index (EDI), and total peak flow (TPF) from 42 women with idiopathic subglottic stenosis without comorbid lower airway or parenchymal lung disease who were treated at a single tertiary referral center between 2014 and 2018 were analyzed. The mean follow-up period was 18.2 months (range, 2-40 months). Ten patients initially screened were not included in the analysis owing to comorbid glottic or supraglottic stenosis or nonidiopathic etiology. Main Outcomes and Measures: Measurements of PEF, EDI, and TPF were taken at preoperative visits and at all other visits. Results: Forty-two women (mean age, 51.5 years; 98% white [n = 41]) met the inclusion criteria. The area under the curve for PEF was 0.855 (95% CI, 0.784-0.926). The optimal cutoff value was 4.4 liters per second (264 L/min), with a sensitivity and specificity of 84.4% and 82.0%, respectively. The area under the curve for EDI was 0.853 (95% CI, 0.782-0.925). For TPF, this was 0.836 (95% CI, 0.757-0.916). Conclusions and Relevance: This study provides evidence supporting the use of PEF as a simple, efficient, and accessible way of monitoring progression of idiopathic subglottic stenosis and predicting receipt of surgical intervention. Sensitivity and specificity of PEF were comparable to those of the more complex measures of TPF and EDI.

Impact of blood transfusions on patients with head and neck cancer undergoing free tissue transfer.

OBJECTIVES/HYPOTHESIS: To determine whether blood transfusions are associated with adverse outcomes in patients with head and neck cancer (HNC) undergoing microvascular free tissue transfer. STUDY DESIGN: Retrospective cohort study. METHODS: The records of all patients who underwent free flaps for reconstruction after HNC resection from July 2007 through February 2013 at a single institution were reviewed. Rates of overall survival (OS), recurrence free survival (RFS), and postoperative wound infection were determined. Statistical analyses included Cox proportional hazards models and chi-square tests. RESULTS: Of 167 patients, 90 received 0 to 2 units of blood and 77 received ≥ 3. After controlling for age, preoperative hemoglobin, preoperative albumin, cancer stage, and adverse pathologic features, transfusion of ≥ 3 (versus 0 to 2) units was associated with poorer OS (P = 0.0006; hazard ratio [HR] = 2.96) and RFS (P = 0.003; HR = 2.35). The rates of wound infection in patients who received 0, 1, 2, or ≥ 3 units were 13.3%, 21.2%, 33.3%, and 31.2%, respectively. There was a statistically significant difference in wound infection rates between those patients receiving 0 to 1 versus ≥ 2 units (P = 0.04). CONCLUSIONS: Patients who receive ≥ 3 units of blood after free tissue transfer for HNC had a significantly increased risk of death after controlling for age, preoperative hemoglobin and albumin, cancer stage, and adverse pathologic features. Increased transfusions are also associated with higher wound infection rates. The increased tendency to transfuse free flap patients in order to maintain a threshold hematocrit may have a detrimental impact on survival and wound infections and should be revisited.

Matrix metalloproteinase-9 is associated with acute inflammation after olfactory injury.

We previously reported an increase in matrix metalloproteinase-9 (MMP-9) levels in the olfactory bulb immediately after nerve transection; however, its role remains unknown. In this study, we determined the source of MMP-9 by monitoring the infiltration of inflammatory leukocytes in the olfactory bulb after nerve transection. We used myeloperoxidase to identify neutrophils and CD68 to identify macrophages at days 1, 7, and 10. MMP-9 colocalized with neutrophils at all three time points but was not contained in macrophages. This is the first study to demonstrate that MMP-9 is associated with early inflammatory response after olfactory injury, and provides insight into mechanisms underlying olfactory injury and recovery processes.

Matrix metalloproteinase-9 and -2 expression in the olfactory bulb following methyl bromide gas exposure.

Matrix metalloproteinase-9 (MMP-9) and MMP-2 are important for recovery following direct traumatic injury within the central nervous system (CNS). However, most CNS injury models include both direct trauma and neuronal deafferentation. This limits the ability to determine if these MMPs are important to one or both components of injury. To establish if MMPs play a role in the deafferentation processes, we investigated MMP-9 and MMP-2 in the olfactory bulb following methyl bromide gas exposure. This injury model lesions neurons within the olfactory epithelium and thereby leads to deafferentation of the bulb without damaging it directly. We measured the response of MMP-9 and MMP-2 in the olfactory bulb from 1 to 60 days during neuronal deafferentation and recovery. MMP-9 increased rapidly on day 5 and remained elevated for 10 days. MMP-2 expression levels were low compared with MMP-9. Immunohistological staining performed on days 1, 5, and 10 revealed MMP-9 was localized to inflammatory cells within the olfactory nerve and glomerular layers. Our results demonstrate MMP-9 is present in inflammatory cells during deafferentation processes in the olfactory bulb. Although MMP-9 is elevated in other CNS injury models, this is the first report to demonstrate an increase in MMP-9 associated with neuronal deafferentation in the absence of direct trauma.