A real-world analysis of hybrid CDA and ACDF compared to multilevel ACDF.

BACKGROUND: Multilevel anterior cervical discectomy and fusion (mACDF) is the gold standard for multilevel spinal disease; although safe and effective, mACDF can limit regular spinal motion and contribute to adjacent segment disease (ASD). Hybrid surgery, composed of ACDF and cervical disc arthroplasty, has the potential to reduce ASD by retaining spinal mobility. This study examined the safety of hybrid surgery by utilizing administrative claims data to compare real-world rates of subsequent surgery and post-procedural hospitalization within populations of patients undergoing hybrid surgery versus mACDF for multilevel spinal disease. METHODS: This observational, retrospective analysis used the MarketScan Commercial and Medicare Database from July 2013 through June 2020. Propensity score matched cohorts of patients who received hybrid surgery or mACDF were established based on the presence of spinal surgery procedure codes in the claims data and followed over a variable post-period. Rates of subsequent surgery and post-procedural hospitalization (30- and 90-day) were compared between hybrid surgery and mACDF cohorts. RESULTS: A total of 430 hybrid surgery patients and 2,136 mACDF patients qualified for the study; average follow-up was approximately 2 years. Similar rates of subsequent surgery (Hybrid: 1.9 surgeries/100 patient-years; mACDF: 1.8 surgeries/100 patient-years) were observed for the two cohorts. Hospitalization rates were also similar across cohorts at 30 days post-procedure (Hybrid: 0.67% hospitalized/patient-year; mACDF: 0.87% hospitalized/patient-year). At 90 days post-procedure, hybrid surgery patients had slightly lower rates of hospitalization compared to mACDF patients (0.23% versus 0.42% hospitalized/patient-year; p < 0.05). CONCLUSIONS: Findings of this real-world, retrospective cohort study confirm prior reports indicating that hybrid surgery is a safe and effective intervention for multilevel spinal disease which demonstrates non-inferiority in relation to the current gold standard mACDF. The use of administrative claims data in this analysis provides a unique perspective allowing the inclusion of a larger, more generalizable population has historically been reported on in small cohort studies.

Mitroflow aortic pericardial bioprosthesis--clinical performance.

OBJECTIVE: Advancing life expectancy with the increased prevalence of aortic valve degenerative disease brings the need for an aortic bioprosthesis with excellent haemodynamic performance and comparable durability. The Mitroflow bioprosthesis has been on the worldwide market, except in the United States, since 1982, while the current model (1991) has only recently gained regulatory approval in the latter country. This study was primarily performed to determine the durability of the current Mitroflow bioprosthesis. METHODS: The contemporary Mitroflow bioprosthesis was implanted in 381 patients in three centres. The mean age was 76.4 years (range 53-91 years) and the mean follow-up period was 5.4+/-3.4 years, a total of 2048.7 years of evaluation. Prosthesis-patient mismatch (PPM) was classified by reference effective orifice area index categories: normal > or = 0.85 cm(2) m(-2) (53.9%), mild 0.84-0.76 cm(2) m(-2) (33.9%), moderate < or = 0.75-0.66 cm(2) m(-2) (11.7%) and severe < or = 0.65 cm(2) m(-2) (0.5%). RESULTS: The survival, at 10 years, was 39.9+/-7.9% for 50-69 years, 27.0+/-3.7% for 70-79 years and 16.6+/-4.4% for > or = 80 years (p=0.011). There was a trend (p=0.063) influencing survival for moderate-to-severe PPM. Of the independent predictors influencing survival--moderate-to-severe projected effective orifice area index (pEOAI) (Hazard Ratio (HR) 1.6, p=0.0142) and left ventricular dysfunction (ejection fraction < 35%) (HR 1.9, p=0.0193) were included. The 10-year freedom from structural valve deterioration (SVD) at explant assessing the same age groups as survival was not different (p=0.081). The 10-year actual/actuarial freedom from SVD, at explant was for > or = 60 years--94.4+/-1.4% (85.2+/-3.9%), for > or = 65 years--94.2+/-1.4% (85.0+/-4.0%), for 61-70 years--97.4+/-2.6% (95.7+/-4.3%) and for > 70 years--94.0+/-1.5% (83.2+/-4.6%). CONCLUSIONS: The Mitroflow external mounted, pericardial aortic bioprosthesis with documented excellent haemodynamics (especially for the small aortic root), demonstrates that prosthesis-patient mismatch in moderate and severe categories can essentially be eliminated, with durability performance comparable to other heterograft (porcine and pericardial) bioprostheses.

Classification of Texas Reservoirs in Relation to Limnology and Fish Community Associations.

I used cluster analysis to examine associations among 20 fish species to develop a classification scheme for 132 large Texas reservoirs. Five major groups of reservoirs were identified by cluster analysis based on species associations. Of 29 reservoirs surveyed previously, 76% were classified into the same species associations from one survey to the next. When 19 environmental variables were used in canonical correlation analysis of the five reservoir groups, I found a general east-to-west separation of species associations by water quality and a northwest-to-southeast separation by surface elevation and growing season. A discriminant functions model based on a reduced set of nine environmental variables had an unbiased error rate of 18% for predicting the species association in unclassified reservoirs. A stratified sampling scheme based on the classification model decreased the variance of statewide electrofishing catch per effort up to 43% for bluegill Lepomis macrochirus and 23% for largemouth bass Micropterus salmoides over a simple random sample of reservoirs.