Research Spotlight

Lara, L. F., M. Takita, J. S. Burdick, D. C. DeMarco, R. R. Pimentel, T. Erim and M. F. Levy (2017). “A study of the clinical utility of a 20-minute secretin-stimulated endoscopic pancreas function test and performance according to clinical variables.” Gastrointest Endosc 86(6): 1048-1055.e1042.

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ACKGROUND AND AIMS: Direct pancreas juice testing of bicarbonate, lipase, or trypsin after stimulation by secretin or cholecystokinin is used to determine exocrine function, a surrogate for diagnosing chronic pancreatitis (CP). Endoscopic pancreas function tests (ePFTs), where a peak bicarbonate concentration (PBC) >/=80 mEq/L in pancreas juice is considered normal, are now used more frequently. In this ePFT, aspirates start 35 minutes after secretin administration because pancreas output peaks 30 minutes after secretagogue administration. The performance of ePFT in a cohort of patients with a presumptive diagnosis of CP referred to a pancreas clinic for consideration of an intervention including total pancreatectomy and islet autotransplantation was studied, compared with EUS, ERCP, histology, and consensus diagnosis. The effect of sedation, narcotic use, aspirate volume, body mass index, age, and proton pump inhibitors (PPIs) on test performance is reported. METHODS: After a test dose, synthetic human secretin was administered intravenously, and 30 minutes later sedation was achieved with midazolam and fentanyl or propofol. A gastroscope was advanced to the major papilla where 4 continuous aspiration samples were performed at 5-minute intervals in sealed bottles. PBC >/=80 mEq/L was normal. RESULTS: Eighty-one patients had ePFTs from August 2010 through October 2015. Twenty-seven patients (33%) were diagnosed with CP. Eighteen of the 27 patients with CP and 1 of the 54 patients without CP had an abnormal ePFT, producing a sensitivity of 66% (95% CI, 46.0-83.5), specificity 98% (95% CI, 90.1-99.9), positive predictive value 94.7% (95% CI, 74-99.9), and negative predictive value 85.5% (95% CI, 74.2-93.1). ERCP and PBC concordance was generally poor, but none of the patients without CP had major EUS changes, and only 3 patients with a PBC <80 mEq/L had a normal EUS. The PBC was affected by narcotics and PPI use. CONCLUSION: A 20-minute ePFT after secretin administration had a marginal sensitivity for diagnosis of CP. The diagnosis of CP should not rely on a single study and certainly not a PFT. The duodenal aspirate volume did not correlate with the PBC, which contrasts with current secretin-enhanced MRCP knowledge; therefore, further studies on this subject are warranted. Neither type of sedation, BMI, nor age affected test performance. Narcotics and PPIs may affect the PBC, so borderline results should be interpreted with caution in these groups.

Ostermann, M., P. A. McCullough, L. G. Forni, S. M. Bagshaw, M. Joannidis, J. Shi, K. Kashani, P. M. Honore, L. S. Chawla and J. A. Kellum (2017). “Kinetics of urinary cell cycle arrest markers for acute kidney injury following exposure to potential renal insults.” Crit Care Med: 2017 Nov [Epub ahead of print].

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OBJECTIVES: Urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 predict the development of acute kidney injury following renal insults of varied aetiology. To aid clinical interpretation, we describe the kinetics of biomarker elevations around an exposure. DESIGN: In an ancillary analysis of the multicenter SAPPHIRE study, we examined the kinetics of the urinary [tissue inhibitor of metalloproteinase-2]*[insulin-like growth factor binding protein 7] in association with exposure to common renal insults (major surgery, IV radiocontrast, vancomycin, nonsteroidal anti-inflammatory drugs, and piperacillin/tazobactam). SETTING: Thirty-five sites in North America and Europe between September 2010 and June 2012. PATIENTS: Seven hundred twenty-three critically ill adult patients admitted to the ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared the urinary [tissue metalloproteinase-2]*[insulin growth factor binding protein 7] kinetics from the day prior to exposure up to 5 days after exposure in patients developing acute kidney injury stage 2-3, stage 1, or no acute kidney injury by Kidney Disease Improving Global Outcome criteria. Among the 723 patients, 679 (94%) had at least one, 70% had more than one, and 35% had three or more exposures to a known renal insult. There was a significant association between cumulative number of exposures up to study day 3 and risk of acute kidney injury (p = 0.02) but no association between the specific type of exposure and acute kidney injury (p = 0.22). With the exception of radiocontrast, patients who developed acute kidney injury stage 2-3 after one of the five exposures, had a clear rise and fall of urinary [tissue inhibitor of metalloproteinase-2]*[insulin-like growth factor binding protein 7] from the day of exposure to 24-48 hours later. In patients without acute kidney injury, there was no significant elevation in urinary [tissue inhibitor of metalloproteinase-2]*[insulin-like growth factor binding protein 7]. CONCLUSIONS: Exposure to potential renal insults is common. In patients developing acute kidney injury stage 2-3, the kinetics of urinary [tissue inhibitor of metalloproteinase-2]*[insulin-like growth factor binding protein 7] matched the exposure except in the case of radiocontrast.

Ogola, G. O., M. L. Crandall and S. Shafi (2017). “Variations in outcomes of emergency general surgery patients across hospitals: A call to establish emergency general surgery quality improvement program (eqip).” J Trauma Acute Care Surg: 2017 Nov [Epub ahead of print].

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BACKGROUND: National Surgical Quality Improvement Program (NSQIP) and Trauma Quality Improvement Program (TQIP) have shown variations in risk-adjusted outcomes across hospitals. Our study hypothesis was that there would be similar variation in risk-adjusted outcomes of Emergency General Surgery (EGS) patients. METHODS: We undertook a retrospective analysis of the National Inpatient Sample database for 2010. Patients with EGS diseases were identified using American Association for the Surgery of Trauma definitions. A hierarchical logistic regression model was used to model in-hospital mortality, accounting for patient characteristics, including age, sex, race, ethnicity, insurance type, and comorbidities. Predicted-to-Expected mortality ratios with 90% confidence intervals, were used to identify hospitals as low mortality (ratio significantly lower than 1), high mortality (ratio significantly higher than 1), or average mortality (ratio overlapping 1). RESULTS: Nationwide, 2,640,725 patients with EGS diseases were treated at 943 hospitals in 2010. About one-sixth of the hospitals (139, 15%) were low mortality, a quarter were high mortality (221, 23%), while the rest were average mortality. Mortality ratio at low mortality hospitals was almost four times lower than that of high mortality hospitals (0.57 vs. 2.03, p < .0001). If high and average mortality hospitals performed at the same level as low mortality hospitals, we estimate 16,812 (55%) more deaths than expected. CONCLUSION: There are significant variations in risk-adjusted outcomes of EGS patients across hospitals, with several thousand higher than expected number of deaths nationwide. Based upon the success of NSQIP and TQIP, we recommend establishing EGS Quality Improvement Program (EQIP) for risk-adjusted benchmarking of hospitals for EGS patients.

Packer, M. (2017). “Are meta-analyses a form of medical fake news? Thoughts about how they should contribute to medical science and practice.” Circulation 136(22): 2097-2099.

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Many physicians believe (incorrectly) that there is something magical about a metaanalysis. A meta-analysis is an observational study, but the author does no original work. Someone simply notices that several articles have data that pertain to a common topic and that they might show similar patterns. How can the patterns be described? In the past, the favored approach was to depict these in a narrative, but this task required insight into the details of each trial and a willingness to ask whether differences in design or execution might have contributed to differences in a study’s findings. The current approach to meta-analysis requires no such intellectual effort; little knowledge is needed about any trial, except that it possesses certain minimum features. Advocates of meta-analyses claim that they select trials for inclusion or exclusion based solely on their methodological qualities without awareness of their results, but it is difficult to understand how that could happen. Can the author of a meta-analysis claim to have read only the methods section of an article, but ignored the title, abstract, results, and discussion?

Oguayo, K. N., C. C. Oguayo, R. Vallabhan and J. W. Choi (2017). “Microcatheter balloon pinning technique to facilitate wiring of a left circumflex chronic total occlusion.” Cardiovasc Ther 35(6): 2017 Nov [Epub ahead of print].

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INTRODUCTION: Coronary chronic total occlusions (CTOs) are commonly encountered during diagnostic angiograms. With recent advances, especially in experienced centers, success rates with CTO percutaneous coronary intervention (PCI) have approached 80% or higher. It is important to note that despite these advancements in techniques, CTOs remain difficult to treat. We present a case of a left circumflex artery (LCX) CTO that was successfully revascularized using a microcatheter balloon pinning technique that allowed additional wire support. CASE REPORT: A 77-year-old woman status post-two-vessel coronary artery bypass graft surgery presented with new onset angina at rest and was found to have a patent graft to the left anterior descending artery, and an unrevascularized proximal LCX CTO. PCI was attempted with a microcatheter using an antegrade approach. This approach was unsuccessful due to the lack of support and the left circumflex angle. As a result, we used a balloon to pin the microcatheter to the wall of the left main to allow for successful wiring of the LCX. A stent was successfully deployed in the LCX, and the patient was discharged from the hospital 2 days later. At follow-up, the patient was asymptomatic and returned to her usual activity. DISCUSSION: After conducting a thorough literature search, it appears that this is the first case that a microcatheter has been pinned with a balloon. We believe that in LCX CTOs that require support, the microcatheter pinning technique can provide adequate support in wiring CTO’s. LCX CTOs can be very difficult to treat, we present a case of a LCX CTO that required the use of the microcatheter balloon pinning technique to allow additional wire support for successful wiring and ultimately treatment.