Research Spotlight

Becker, T. M., P. A. Grayburn and W. C. Roberts (2017). “Mitral valve repair for pure mitral regurgitation followed years later by mitral valve replacement for mitral stenosis.” Am J Cardiol 120(1): 160-166.

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We describe herein 2 patients who developed severe mitral stenosis (MS) approximately two decades after a mitral valve repair operation for pure mitral regurgitation (MR) secondary to mitral valve prolapse. This report’s purpose is to point out that use of a circumferential mitral annular ring during the repair has the potential to produce a transmitral pressure gradient just like that occurring after mitral valve replacement utilizing a mechanical prosthesis or a bioprosthesis in the mitral position.

Blanke, P., J. K. Park, P. Grayburn, C. Naoum, K. Ong, K. Kohli, B. L. Norgaard, J. G. Webb, J. Popma, D. Boshell, P. Sorajja, D. Muller and J. Leipsic (2017). “Left ventricular access point determination for a coaxial approach to the mitral annular landing zone in transcatheter mitral valve replacement.” J Cardiovasc Comput Tomogr 11(4): 281-287.

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INTRODUCTION: To facilitate coaxial device deployment in transcatheter mitral valve replacement (TMVR), a coaxial approach to the mitral annular plane is needed. We sought to establish a method to determine an ‘orthogonal’ left ventricular (LV) access point for transapical TMVR and to quantitatively characterize its location in patients with severe mitral regurgitation using cardiac computed tomography. METHODS: Cardiac CT data sets of 54 patients with moderate-severe mitral regurgitation evaluated for potential TMVR were analyzed. The D-shaped mitral annular contour was segmented and a 2-dimensional annular plane was derived, allowing for subsequent definition of the perpendicularly oriented mitral annular trajectory. The ‘orthogonal’ LV access point was defined as the transection point of mitral trajectory with the LV epicardial surface. The location of the access point was quantified by its epicardial distance from the true apex and by the rotational offset from a 3-chamber view. RESULTS: LV access points orthogonal to the mitral annular plane were most frequently located in the anterolateral (n = 22, 40.7%) and anterior (n = 16, 29.6%), less frequently anteroseptal (n = 6, 11.1%) and inferolateral (n = 5, 9.3%) ventricular segment; none inferior or inferoseptal. The mean distance to the LV apex was 17.6 +/- 7.7 mm. The mean forward rotational offset from the 3-chamber view was 96.4 +/- 43.4 degrees , relating to a mean forward rotational offset of 6.4 +/- 43.4 degrees in regard to a hypothetical, secondary 90 degrees x-plane view. No significant difference between patients with degenerative mitral valve disease or functional mitral regurgitation was observed. CONCLUSION: The location of the LV access point that provides an orthogonal trajectory to the mitral annular plane exhibits relevant inter-individual variability. It is commonly not identical with the true apex, and frequently localized in the anterolateral or anterior ventricular segments.

Moore, L., C. J. Kramer, S. Delcoix-Lopes and A. M. Modrykamien (2017). “Comparison of cisatracurium versus atracurium in early ards.” Respir Care 62(7): 947-952.

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BACKGROUND: Administration of cisatracurium in severe ARDS decreases in-hospital mortality. Whether clinical outcomes are cisatracurium-specific or related with all neuromuscular blockers is unknown. This study aimed to compare outcomes in severe ARDS patients treated with cisatracurium versus atracurium. METHODS: Patients admitted in ICUs with a diagnosis of severe ARDS and treated with neuromuscular blocking agents within 72 h of diagnosis were included. Subjects treated with cisatracurium versus atracurium were compared. The primary outcome was improvement in oxygenation, defined as the difference of PaO2 /FIO2 at 72 h post-initiation of neuromuscular blocking agents. Secondary outcomes were ventilator-free days at day 28, ICU and hospital lengths of stay, and hospital mortality. RESULTS: Seventy-six subjects with ARDS were included in the study. Eighteen subjects (24%) were treated with atracurium, whereas 58 (76%) were treated with cisatracurium. Equivalent dosages of sedation and analgesia as well as use of brain function monitoring technology were similar between both groups. There were no differences in clinical outcomes. Specifically, improvement of PaO2 /FIO2 was a median (interquartile range [IQR]) of 65 (25-162) in the atracurium group and 66 (IQR 16-147) in the cisatracurium group (P = .65). Ventilator-free days at day 28 were 13 d (IQR 0-22 d) and 15 d (IQR 8-21 d) in the atracurium and cisatracurium groups, respectively (P = .72). ICU length or stay was 18 d (IQR 8-34 d) in the atracurium group and 15 d (IQR 9-22 d) in the cisatracurium group (P = .34). In-hospital mortality was 50% for the atracurium population and 62% for the cisatracurium group (P = .42) CONCLUSIONS: Among subjects with early severe ARDS, the utilization of atracurium versus cisatracurium within 72 h of admission was not associated with significant differences in clinical outcomes.

Wardly, D., L. M. Wolford and V. Veerappan (2017). “Idiopathic intracranial hypertension eliminated by counterclockwise maxillomandibular advancement: A case report.” Cranio 35(4): 259-267.

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INTRODUCTION: Obstructive sleep apnea (OSA) is a secondary cause of intracranial hypertension (IH). Decreased jugular venous drainage has been seen in patients with idiopathic IH. CLINICAL PRESENTATION: A complex case of a 48-year-old female whose idiopathic IH was put into remission after counterclockwise maxillomandibular advancement (CC-MMA), despite persistence of her OSA. CONCLUSION: This case highlights the relationship between OSA and IH and points to the significant morbidity that can result from mild OSA and from what are considered borderline intracranial pressures. This indicates the need for a high index of suspicion for actual underlying pathology that can be surgically corrected when patients manifest symptoms of a somatic syndrome. This is the first report in the medical literature of clinical elimination of IH by CC-MMA. The authors propose that this positive outcome was effected via mandibular advancement producing a decrease in jugular venous resistance, allowing improved absorption of cerebrospinal fluid.

Keller, D. S., A. J. Senagore, K. Fitch, A. Bochner and E. M. Haas (2017). “A new perspective on the value of minimally invasive colorectal surgery-payer, provider, and patient benefits.” Surg Endosc 31(7): 2846-2853.

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BACKGROUND: The clinical benefits of minimally invasive surgery (MIS) are proven, but overall financial benefits are not fully explored. Our goal was to evaluate the financial benefits of MIS from the payer’s perspective to demonstrate the value of minimally invasive colorectal surgery. METHODS: A Truven MarketScan(R) claim-based analysis identified all 2013 elective, inpatient colectomies. Cases were stratified into open or MIS approaches based on ICD-9 procedure codes; then costs were assessed using a similar distribution across diagnosis related groups (DRGs). Care episodes were compared for average allowed costs, complication, and readmission rates after adjusting costs for demographics, comorbidities, and geographic region. RESULTS: A total of 4615 colectomies were included-2054 (44.5 %) open and 2561 (55.5 %) MIS. Total allowed episode costs were significantly lower MIS than open ($37,540 vs. $45,284, p < 0.001). During the inpatient stay, open cases had significantly greater ICU utilization (3.9 % open vs. 2.0 % MIS, p < 0.001), higher overall complications (52.8 % open vs. 32.3 % MIS, p < 0.001), higher colorectal-specific complications (32.5 % open vs. 17.9 % MIS, p < 0.001), longer LOS (6.39 open vs. 4.44 days MIS, p < 0.001), and higher index admission costs ($39,585 open vs. $33,183 MIS, p < 0.001). Post-discharge, open cases had significantly higher readmission rates/100 cases (11.54 vs. 8.28; p = 0.0013), higher average readmission costs ($3055 vs. $2,514; p = 0.1858), and greater 30-day healthcare costs than MIS ($5699 vs. $4357; p = 0.0033). The net episode cost of care was $7744/patient greater for an open colectomy, even with similar DRG distribution. CONCLUSIONS: In a commercially insured population, the risk-adjusted allowed costs for MIS colectomy episodes were significantly lower than open. The overall cost difference between MIS and open was almost $8000 per patient. This highlights an opportunity for health plans and employers to realize financial benefits by shifting from open to MIS for colectomy. With increasing bundled payment arrangements and accountable care sharing programs, the cost impact of shifting from open to MIS introduces an opportunity for cost savings.