Research Spotlight

Albilia, J. B., H. Weisleder and L. M. Wolford (2018). “Treatment of Posterior Dislocation of the Mandibular Condyle With the Double Mitek Mini Anchor Technique: A Case Report.” J Oral Maxillofac Surg 76(2): 396.e391-396.e399.

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Posterior dislocation of the mandibular condyle is a rare disorder caused by trauma to the chin accompanied by damage to the external auditory canal. Treatment of posterior condylar dislocation (PCD) is directed at repositioning the condyle into the glenoid fossa, preventing recurrent dislocations, and maintaining patency of the ear canal. With early intervention, closed reduction with manual manipulation is successful but could be ineffective for chronic protracted PCD. This case report describes an elderly patient with a chronic protracted PCD resulting from a blow to the chin and in which manual reduction was unsuccessful. An open arthroplasty for condylar reduction and application of a “reverse” double Mitek mini anchor technique was required to prevent recurrence of PCD, with a successful outcome.

Ahmad, K. A., M. M. Bennett, S. F. Ahmad, R. H. Clark and V. N. Tolia (2018). “Morbidity and mortality with early pulmonary haemorrhage in preterm neonates.” Arch Dis Child Fetal Neonatal Ed. Jan 27 [Epub ahead of print].

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OBJECTIVE: There are no large studies evaluating pulmonary haemorrhage (PH) in premature infants. We sought to quantify the clinical characteristics, morbidities and mortality associated with early PH. DESIGN: Data were abstracted from the Pediatrix Clinical Data Warehouse, a large de-identified data set. For incidence calculations, we included infants from 340 Pediatrix United States Neonatal Intensive Care Units from 2005 to 2014 without congenital anomalies. Infants <28 weeks' gestation with PH within 7 days of birth were then matched with two controls for birth weight, gestational age, gender, antenatal steroid exposure, day of life 0 or 1 intubation and multiple gestation. RESULTS: From 596 411 total infants, we identified 2799 with a diagnosis of PH. Peak incidence was 86.9 cases per 1000 admissions for neonates born at 24 weeks' gestation. We then identified 1476 infants <28 weeks' gestation with an early PH diagnosis at

Mehrotra, S., V. Kilambi, K. Bui, R. Gilroy, S. P. Alexopoulos, D. S. Goldberg, D. P. Ladner and G. B. Klintmalm (2018). “A Concentric Neighborhood Solution to Disparity in Liver Access That Contains Current UNOS Districts.” Transplantation 102(2): 255-278.

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BACKGROUND: Policymakers are deliberating reforms to reduce geographic disparity in liver allocation. Public comments and the United Network for Organ Sharing Liver and Intestinal Committee have expressed interest in refining the neighborhoods approach. Share 35 and Share 15 policies affect geographic disparity. METHODS: We construct concentric neighborhoods superimposing the current 11 regions. Using concepts from concentric circles, we construct neighborhoods for each donor service area (DSA) that consider all DSAs within 400, 500, or 600 miles as neighbors. We consider limiting each neighborhood to 10 DSAs and use no metrics for liver supplies and demands. We change Model for End-Stage Liver Disease (MELD) thresholds for the Share 15 policy to 18 or 20 and apply 3- and 5-point MELD proximity boosts to enhance local priority, control travel distances, and reduce disparity. We conduct simulations comparing current allocation with the neighborhoods and sharing policies. RESULTS: Concentric neighborhoods structures provide an array of solutions where simulation results indicate that they reduce geographic disparity, annual mortalities, and the airplane travel distances by varying degrees. Tuning of the parameters and policy combinations can lead to beneficial improvements with acceptable transplant volume loss and reductions in geographic disparity and travel distance. Particularly, the 10-DSA, 500-mile neighborhood solution with Share 35, Share 15, and 0-point MELD boost achieves such while limiting transplant volume losses to below 10%. CONCLUSIONS: The current 11 districts can be adapted systematically by adding neighboring DSAs to improve geographic disparity, mortality, and airplane travel distance. Modifications to Share 35 and Share 15 policies result in further improvements. The solutions may be refined further for implementation.

Friedman, D. J., J. P. Piccini, T. Wang, J. Zheng, S. C. Malaisrie, D. R. Holmes, R. M. Suri, M. J. Mack, V. Badhwar, J. P. Jacobs, J. G. Gaca, S. C. Chow, E. D. Peterson and J. M. Brennan (2018). “Association Between Left Atrial Appendage Occlusion and Readmission for Thromboembolism Among Patients With Atrial Fibrillation Undergoing Concomitant Cardiac Surgery.” JAMA 319(4): 365-374.

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Importance: The left atrial appendage is a key site of thrombus formation in atrial fibrillation (AF) and can be occluded or removed at the time of cardiac surgery. There is limited evidence regarding the effectiveness of surgical left atrial appendage occlusion (S-LAAO) for reducing the risk of thromboembolism. Objective: To evaluate the association of S-LAAO vs no receipt of S-LAAO with the risk of thromboembolism among older patients undergoing cardiac surgery. Design, Setting, and Participants: Retrospective cohort study of a nationally representative Medicare-linked cohort from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2012). Patients aged 65 years and older with AF undergoing cardiac surgery (coronary artery bypass grafting [CABG], mitral valve surgery with or without CABG, or aortic valve surgery with or without CABG) with and without concomitant S-LAAO were followed up until December 31, 2014. Exposures: S-LAAO vs no S-LAAO. Main Outcomes and Measures: The primary outcome was readmission for thromboembolism (stroke, transient ischemic attack, or systemic embolism) at up to 3 years of follow-up, as defined by Medicare claims data. Secondary end points included hemorrhagic stroke, all-cause mortality, and a composite end point (thromboembolism, hemorrhagic stroke, or all-cause mortality). Results: Among 10524 patients undergoing surgery (median age, 76 years; 39% female; median CHA2DS2-VASc score, 4), 3892 (37%) underwent S-LAAO. Overall, at a mean follow-up of 2.6 years, thromboembolism occurred in 5.4%, hemorrhagic stroke in 0.9%, all-cause mortality in 21.5%, and the composite end point in 25.7%. S-LAAO, compared with no S-LAAO, was associated with lower unadjusted rates of thromboembolism (4.2% vs 6.2%), all-cause mortality (17.3% vs 23.9%), and the composite end point (20.5% vs 28.7%) but no significant difference in rates of hemorrhagic stroke (0.9% vs 0.9%). After inverse probability-weighted adjustment, S-LAAO was associated with a significantly lower rate of thromboembolism (subdistribution hazard ratio [HR], 0.67; 95% CI, 0.56-0.81; P < .001), all-cause mortality (HR, 0.88; 95% CI, 0.79-0.97; P = .001), and the composite end point (HR, 0.83; 95% CI, 0.76-0.91; P < .001) but not hemorrhagic stroke (subdistribution HR, 0.84; 95% CI, 0.53-1.32; P = .44). S-LAAO, compared with no S-LAAO, was associated with a lower risk of thromboembolism among patients discharged without anticoagulation (unadjusted rate, 4.2% vs 6.0%; adjusted subdistribution HR, 0.26; 95% CI, 0.17-0.40; P < .001), but not among patients discharged with anticoagulation (unadjusted rate, 4.1% vs 6.3%; adjusted subdistribution HR, 0.88; 95% CI, 0.56-1.39; P = .59). Conclusions and Relevance: Among older patients with AF undergoing concomitant cardiac surgery, S-LAAO, compared with no S-LAAO, was associated with a lower risk of readmission for thromboembolism over 3 years. These findings support the use of S-LAAO, but randomized trials are necessary to provide definitive evidence.

Widmer, R. J., M. W. Cullen, B. R. Salonen, K. K. Sundsted, D. Raslau, A. B. Mohabbat, B. M. Dougan, D. M. Bierle, D. K. Lawson, A. J. Widmer, M. Bundrick, P. Gaba, R. Tellez, D. R. Schroeder, R. B. McCully and K. F. Mauck (2018). “Cardiac Events after Non-Cardiac Surgery in Patients Undergoing Pre-Operative Dobutamine Stress Echocardiography Findings From the Mayo Poce-DSE Investigators.” Am J Med. Jan 15. [Epub ahead of print].

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BACKGROUND: Current guidelines support the use of dobutamine stress echocardiography (DSE) prior to non-cardiac surgery in higher risk patients who are unable to perform at least 4 metabolic equivalents of physical activity. We evaluated post-operative outcomes of patients in different operative risk categories after pre-operative DSE. METHODS: We collected data from the medical record on 4,494 patients from January 1, 2006 to December 31, 2011 who had DSE up to 90 days prior to a non-cardiac surgery. Patients were divided into low, intermediate, and high pre-operative surgery-specific risk. Baseline demographic data and risk factors were abstracted from the medical record as were postoperative cardiac events including myocardial infarction, cardiac arrest, and mortality within 30 days after surgery. RESULTS: There were 103 cardiac outcomes (2.3%), which included myocardial infarction (n=57, 1.3%), resuscitated cardiac arrest (n=26, 0.6%), and all-cause mortality (n=40, 0.9%). Cardiac event rates were 0.0% (95% C.I. 0.0% to 3.9%) in the low surgical risk group, 2.1% (95% C.I. 1.6% to 2.5%) in the intermediate surgical risk group, and 3.4% (95% C.I. 2.0% to 4.4%) in the high risk group. Thirty day post-operative mortality rates were 0%, 0.9%, and 0.8% for the low-risk, intermediate-risk, and high-risk surgical groups, respectively, and were not statistically different. CONCLUSIONS: These findings demonstrate low cardiac event rates in patients who underwent a DSE prior to non-cardiac surgery. The previously accepted construct of low, intermediate and high risk surgeries based on postoperative events of <1%, 1-5%, and > 5% overestimates the actual risk in contemporary settings.