Management of Enlarging Tracheoesophageal Fistula with Voice Prosthesis in Laryngectomized Patients.

Management of Enlarging tracheoesophageal fistula (TEF) with Voice Prosthesis in Laryngectomized Head and Neck Cancer Patients. OBJECTIVES: An enlarging TEF following voice prosthesis placement impacts patient quality of life, risks airway compromise, and can lead to aspiration pneumonia. Pharyngoesophageal strictures have previously been reported to be associated with TEF enlargement and leakage. We describe a series of patients with enlarging TEFs after Tracheoesophageal puncture (TEP) for voice prosthesis who required pharyngoesophageal reconstruction. METHODS: Retrospective case series of laryngectomized H&N cancer patients with primary or secondary TEP who underwent surgical management for enlarging TEF site between 6/2016-11/2022. RESULTS: Eight patients were included. The mean age was 62.8 years old. Seven patients had a history of hypothyroidism. Of seven with prior H&N radiation history, two had both historical and adjuvant radiation. Two of the eight TEPs were placed secondarily. Mean time from TEP to enlarging TEF diagnosis was 891.3 days. Radial forearm-free flaps were used in five patients. Six had stenosis proximal to the TEF whereas one had distal stenosis and one had no evidence of stenosis. Mean length of stay was 12.3 days. Mean follow-up was 400.4 days. Two required a second free flap for persistent fistula. CONCLUSION: Surgical reconstruction of enlarging TEFs due to TEP/VP placement is effective in combination with addressing underlying pharyngeal/esophageal stenosis contributing to TEF enlargement and leakage. Radial forearm-free flaps have the additional benefit of a long vascular pedicle to access more distant and less-irradiated recipient vessels. Many fistulae are resolved after the first flap reconstruction, but some may require subsequent reconstruction in case of failure. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:198-206, 2024.

Cost-analysis of in-office versus operating room sialendoscopy: Comparison of cost burden and outcomes.

PURPOSE: Office-based procedures in otolaryngology are increasingly utilized to increase efficiency, reduce cost, and eliminate risks associated with surgery. Gland-preserving surgical management of sialadenitis and sialolithiasis are often performed in the operating room, although many surgeons are moving this practice to clinic. We aim to determine the difference in patient charges and perioperative outcomes for salivary gland procedures performed in the clinic versus the OR. METHODS: Retrospective series of patients presenting with sialolithiasis, acute or chronic sialadenitis, and stricture between 2010 and 2019. Demographics, perioperative variables, setting, and charge data were collected. RESULTS: 528 patients underwent operative intervention (n = 427 office, n = 101 OR). Cohort demographics were comparable. Sialolithiasis was the most common presenting diagnosis in both cohorts. Both cohorts had similar rates of complete (p = 0.09) and partial (p = 0.97) response to treatment. A higher percentage of patients in the OR group reported no improvement (21.4 vs 12.2%, p = 0.034). Overall complications were similar (p = 0.582). Mean charges were statistically greater in the OR ($5560.35 OR vs $1298.33 office, p < 0.001). Operative time was significantly reduced in the office group (21.8 min vs 60.85 min, p < 0.001). CONCLUSIONS: Appropriately selected patients can be successfully treated in outpatient clinic without compromising patient safety or quality while significantly reducing the financial burden to patients and the healthcare system.

Classifying highly imbalanced ICU data.

Highly imbalanced data sets are those where the class of interest is rare. In this paper, we compare the performance of several common data mining methods, logistic regression, discriminant analysis, Classification and Regression Tree (CART) models, C5, and Support Vector Machines (SVM) in predicting the discharge status (alive or deceased, with "deceased" being the class of interest) of patients from an Intensive Care Unit (ICU). Using a variety of misclassification cost ratio (MCR) values and using specificity, recall, precision, the F-measure, and confusion entropy (CEN) as criteria for evaluating each method's performance, C5 and SVM performed better than the other methods. At a MCR of 100, C5 had the highest recall and SVM the highest specificity and lowest CEN. We also used Hand's measure to compare the five methods. According to Hand's measure, logistic regression performed the best. This article makes several contributions. We show how the use of MCR for analyzing imbalanced medical data significantly improves the method's classification performance. We also found that the F-measure and precision did not improve as the MCR was increased.

Observations on surgical demand time series: detection and resolution of holiday variance.

BACKGROUND: Surgical scheduling is complicated by both naturally occurring and human-induced variability in the demand for surgical services. Surgical demand time series are decomposed into periodic, lagged, and linear trends with frequent occurrences of nonconstant variations in mean and variance. The authors used time series methods to model surgical demand time series in order to improve the scheduling of scarce surgical resources. METHODS: With institutional approval, the authors studied 47,752 surgeries undertaken at a large academic medical center. They initially extracted periodic information from the time series using two frequency domain techniques: the harmonic F test and the multitaper test. They subsequently extracted lagged (correlated) behavior using a seasonal autoregressive integrated moving average model. Finally, they used moving variance filters on the residuals to identify variance in the time series that coincided with major US holidays. RESULTS: Linear terms such as periodic cycles, trends, and daily and weekly lags explained 80% of the variance in the raw time series. In the residuals, the authors used moving variance filters to detect nonlinear variance artifacts that correlated with surgical activities on specific US holidays. CONCLUSIONS: After extracting linear terms, the remaining variance was attributable to a combination of nonlinear and unexplained random events. The authors used the term holiday variance to describe a specific nonlinear disturbance in surgical demand attributable to statutory US holidays. Resolving these holiday variances may assist in management and scheduling of scarce surgical personnel and resources.

Modeling ischemia-induced dyssynchronous myocardial contraction.

Left ventricular (LV) contraction dyssynchrony is not easily quantified. We previously described a model for quantifying LV dyssynchrony that referenced regional amplitude and phase angles to global LV systole using esmolol-induced regional dyskinesis. We tested the hypothesis that our sine wave model and phase angle analysis of regional dyssynchrony in a canine model could also assess dyssynchrony of contraction during regional ischemia. Hence we compared intracoronary esmolol and matched regional ischemia in 10 anesthetized open-chest dogs. Regional and total LV volumes (conductance catheter), piezoelectric crystal shortening, and LV pressures were measured before, during, and after esmolol-induced apical dyskinesis and matched regional ischemia. We defined regional phase angle of contraction (alpha) as the relative distance, measured in degrees, that regional minimal volume differed from global end-systole. We also compared maximal stroke volume (SV), observed effective SV (that portion of regional SV contributing to total SV for each treatment), and calculated effective SV (total regional SV x cosine alpha). Dobutamine infusion increased homogeneity of regional alpha relative to baseline. Both esmolol and ischemia significantly delayed (P < 0.05) apical contraction as quantified by increased alpha (12.4 degrees +/- 28.1 degrees to 27.4 degrees +/- 30.4 degrees and 54.2 degrees +/- 32.6 degrees , respectively) (mean +/- sd) and decreased regional effective SV (4.7 +/- 2.5 mL to 3.6 +/- 2.2 mL and 4 +/- 2.5 mL, respectively) relative to baseline. Our study indicates that intracoronary esmolol and ischemia induced qualitatively similar mechanical effects on myocardial function and that a sine wave model to estimate regional effective SV is a sensitive method to detect and quantify regional dyssynchrony induced by ischemia. Potentially, phase angle and regional amplitude analyses may prove to be effective measures to identify and quantify the beneficial effects of resynchronization therapies on myocardial function.

An outpatient segmentation model: estimation of stakeholder costs.

This research describes a constraint-based heuristic model of capacity segmentation for outpatient facilities used to estimate the effect of segmentation constraints on stakeholders. Growth of free-standing ambulatory surgery centres has been dramatic in recent years with institutions being urged by governments and insurers to segment inpatients (IP) and outpatients (OP) to reduce costs and improve services. Critics of segmentation argue it is a false economy to separate inpatients and outpatients since pooling of patients in large IP facilities offers economies of scale and opportunities for parallel processing, not to mention elimination of infrastructure. We implemented a constraint-based heuristic model of capacity segmentation for OP facilities and used it to estimate the effect of segmentation on stakeholders.

Estimating procedure times for surgeries by determining location parameters for the lognormal model.

We present an empirical study of methods for estimating the location parameter of the lognormal distribution. Our results identify the best order statistic to use, and indicate that using the best order statistic instead of the median may lead to less frequent incorrect rejection of the lognormal model, more accurate critical value estimates, and higher goodness-of-fit. Using simulation data, we constructed and compared two models for identifying the best order statistic, one based on conventional nonlinear regression and the other using a data mining/machine learning technique. Better surgical procedure time estimates may lead to improved surgical operations.

Estimating times of surgeries with two component procedures: comparison of the lognormal and normal models.

BACKGROUND: Variability inherent in the duration of surgical procedures complicates surgical scheduling. Modeling the duration and variability of surgeries might improve time estimates. Accurate time estimates are important operationally to improve utilization, reduce costs, and identify surgeries that might be considered outliers. Surgeries with multiple procedures are difficult to model because they are difficult to segment into homogenous groups and because they are performed less frequently than single-procedure surgeries. METHODS: The authors studied, retrospectively, 10,740 surgeries each with exactly two CPTs and 46,322 surgical cases with only one CPT from a large teaching hospital to determine if the distribution of dual-procedure surgery times fit more closely a lognormal or a normal model. The authors tested model goodness of fit to their data using Shapiro-Wilk tests, studied factors affecting the variability of time estimates, and examined the impact of coding permutations (ordered combinations) on modeling. RESULTS: The Shapiro-Wilk tests indicated that the lognormal model is statistically superior to the normal model for modeling dual-procedure surgeries. Permutations of component codes did not appear to differ significantly with respect to total procedure time and surgical time. To improve individual models for infrequent dual-procedure surgeries, permutations may be reduced and estimates may be based on the longest component procedure and type of anesthesia. CONCLUSIONS: The authors recommend use of the lognormal model for estimating surgical times for surgeries with two component procedures. Their results help legitimize the use of log transforms to normalize surgical procedure times prior to hypothesis testing using linear statistical models. Multiple-procedure surgeries may be modeled using the longest (statistically most important) component procedure and type of anesthesia.

Does dobutamine improve ventricular function in dogs with regional myocardial dysfunction?

UNLABELLED: We studied the effect of systemic dobutamine infusion (4 microg. kg(-1). min(-1) IV) on regional wall motion abnormalities (RWMAs) in eight anesthetized open-chested dogs. We hypothesized that infusion of small doses of dobutamine would reduce RWMAs and improve global ventricular function. Apical RWMAs were induced by local intracoronary boluses of 9.0 mg esmolol. Phase angles, effective stroke volume (SV), maximum SV, stroke work, and segmental shortening were compared among four left ventricular (LV) regions (apical, papillary, chordal, and basal) during baseline, dobutamine, esmolol, and dobutamine-esmolol treatments. The minimal global LV volume was designated as 0 degrees, and the cardiac cycle was divided into 360 intervals. Regional phase angles were defined as the distance (in degrees) that regional minimum volume differed from global minimal LV volume (end-systole). RWMA decreased blood pressure (92 +/- 2 mm Hg to 84 +/- 3 mm Hg) and increased LV end-diastolic pressure (1.8 +/- 0.5 mm Hg to 4.2 +/- 0.8 mm Hg). RWMA delayed regional contraction (-2.9 degrees +/- 1.6 degrees to 52.3 degrees +/- 1.5 degrees ) and decreased effective SV (2.3 +/- 0.4 mL to 1.6 +/- 0.3 mL) in the affected apical region but did not decrease maximal SV. Systemic infusion of dobutamine restored global LV function but failed to eliminate RWMA, as evidenced by decreased apical synchrony, effective SV, and stroke work. We concluded that systemic dobutamine restored global LV function but failed to correct RWMA. IMPLICATIONS: We examined the effect of systemic dobutamine on regional wall motion abnormalities (RWMAs) induced by intracoronary esmolol infusion in eight anesthetized dogs. Esmolol dilated the heart and decreased regional synchrony of contraction. Dobutamine restored cardiac function but failed to correct the asynchrony of regional contraction caused by esmolol-induced RWMAs.

A data mining approach to characterizing medical code usage patterns.

This research describes a synthetic data mining approach to identifying diagnostic (ICD-9) and procedure (CPT) code usage patterns in two US. hospitals, with the goal of determining the adequacy and effectiveness of the current coding classification systems. We combine relative frequency measurements with measures of industry concentration borrowed from industrial economics in order to (1) ascertain the extent to which physicians utilize the available codes in classifying patients and (2) discover the factors that impinge on code usage. Our results partition the domain into areas for which the coding systems perform well and those areas for which the systems perform relatively poorly. The goal is to use this approach to understand how coding systems are used and to highlight areas for targeted improvement of the current coding