Research Spotlight

Leeds, S. G., M. Mencio, E. Ontiveros and M. A. Ward (2019). “Endoluminal Vacuum Therapy: How I Do It.” J Gastrointest Surg Jan 22. [Epub ahead of print].

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Perforations and leaks of the gastrointestinal tract are difficult to manage and are associated with high morbidity and mortality. Recently, endoscopic approaches have been applied with varying degrees of success. Most recently, the use of endoluminal vacuum therapy has been used with high success rates in decreasing both morbidity and mortality. Under an IRB-approved prospective registry that we started in July 2013, we have been using endoluminal vacuum therapy to treat a variety of leaks throughout the GI tract. The procedure uses an endosponge connected to a nasogastric tube that is endoscopically guided into a fistula cavity in order to facilitate healing, obtain source control, and aid in reperfusion of the adjacent tissue with debridement. Endoluminal vacuum therapy has been used on all patients in the registry. Overall success rate for healing the leak or fistula is 95% in the esophagus, 83% in the stomach, 100% in the small bowel, and 60% of colorectal cases. The purpose of this report is to review the history of endoluminal wound vacuum therapy, identify appropriate patient selection criteria, and highlight “pearls” of the procedure. This article is written in the context of our own clinical experience, with a primary focus on a “How I Do It” technical description.

Lai, J. C., R. Rahimi, E. C. Verna, M. R. Kappus, M. A. Dunn, M. McAdams-DeMarco, C. E. Haugen, M. L. Volk, A. Duarte-Rojo, D. R. Ganger, G. O’Leary J, J. L. Dodge, D. Ladner and D. Segev (2019). “Frailty Associated With Waitlist Mortality Independent of Ascites and Hepatic Encephalopathy in a Multi-Center Study.” Gastroenterology Jan 17. [Epub ahead of print].

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BACKGROUND & AIMS: Frailty is associated with mortality in patients with cirrhosis. We measured frailty using 3 simple tests and calculated liver frailty index (LFI) scores for patients at multiple ambulatory centers. We investigated associations between LFI scores, ascites, and hepatic encephalopathy (HE) and mortality. METHODS: Adults without hepatocellular carcinoma who were on the liver transplant waitlist at 9 centers in the United States (n=1044) were evaluated using the LFI LFI scores of 4.5 or more indicated that patients were frail. We performed logistic regression analyses to assess associations between frailty and ascites or HE and competing risk regression analyses (with liver transplantation as the competing risk) to estimate subhazard ratios (sHR) of waitlist mortality (death or removal from the waitlist). RESULTS: Of study subjects, 36% had ascites, 41% had HE, and 25% were frail. The odds of frailty were higher for patients with ascites (adjusted odd ratio, 1.56 95% CI, 1.15-2.14) or HE (OR, 2.45 95% CI, 1.80-3.33) than without these features. Higher proportions of frail patients with ascites (29%) or HE (30%) died while on the waitlist compared to patients who were not frail (17% of patients with ascites and 20% with HE). In univariable analysis, ascites (sHR, 1.52 95% CI, 1.14-2.05), HE (sHR, 1.84 95% CI, 1.38-2.45), and frailty (sHR, 2.38 95% CI, 1.77-3.20) were associated with waitlist mortality. In adjusted models, only frailty remained significantly associated with waitlist mortality (sHR, 1.82 95% CI, 1.31-2.52)-ascites and HE were not. CONCLUSIONS: Frailty is a prevalent complication of cirrhosis that is observed more frequently in patients with ascites or HE and independently associated with waitlist mortality. LFI scores can be used to objectively quantify risk of death related to frailty – in excess of liver disease severity – in patients with cirrhosis.

Kilic, A., J. N. Katz, S. M. Joseph, M. A. Brisco-Bacik, N. Uriel, B. Lima, R. Agarwal, R. Bharmi, D. J. Farrar and S. Lee (2019). “Changes in pulmonary artery pressure before and after left ventricular assist device implantation in patients utilizing remote haemodynamic monitoring.” ESC Heart Fail 6(1): 138-145.

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AIMS: The time course of changes in pulmonary artery (PA) pressure due to left ventricular assist devices (LVADs) is not well understood. Here, we describe longitudinal haemodynamic trends during the peri-LVAD implantation period in patients previously implanted with a remote monitoring PA pressure sensor. METHODS AND RESULTS: We retrospectively studied PA pressure trends in patients implanted with CardioMEMS PA pressure sensor between October 2007 and March 2017 who subsequently had an LVAD procedure. Data are presented as mean +/- standard deviation, and P-values are calculated using standard t-test with equal variance. Among 436 patients in cohort, 108 (age 58 +/- 11 years, 82% male) received an LVAD and 328 (age 60 +/- 13 years, 70% male) did not. The mean PA pressure at sensor implant was higher by 29% (P < 0.001) among patients who later received LVAD. Mean PA pressure 6 months prior to LVAD implant was 35.5 +/- 8.5 mmHg, increasing to 39.4 +/- 9.9 mmHg (P = 0.04) at 4 weeks before LVAD, and then decreasing 27% to 28.8 +/- 8.4 mmHg (P < 0.001) at 3 months post-implant and stabilizing at 31.0 +/- 9.4 mmHg at 1 year. CONCLUSIONS: Patients who later receive LVADs have higher PA pressures at sensor implant and show a further increase leading up to LVAD implantation. There is a significant reduction of PA pressures post-LVAD implantation that persists long term. PA pressure monitoring may aid in the clinical decision making of timing for LVAD implantation and in management of LVAD patients.

Idriss, R., J. Hasse, T. Wu, F. Khan, G. Saracino, G. McKenna, G. Testa, J. Trotter, G. Klintmalm and S. K. Asrani (2019). “Impact of Prior Bariatric Surgery on Perioperative Liver Transplant Outcomes.” Liver Transpl 25(2): 217-227.

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Bariatric surgery (BS) is effective in treating morbid obesity, but the impact of prior BS on candidacy for liver transplantation (LT) is unclear. We examined 78 patients with cirrhosis with prior BS compared with a concurrent cohort of 156 patients matched by age, Model for End-Stage Liver Disease score, and underlying liver disease. We compared rates of transplant denial after evaluation, delisting on the waiting list, and survival after LT. The median time from BS to LT evaluation was 7 years. Roux-en-Y gastric bypass was the most common BS procedure performed (63% of cohort). Nonalcoholic fatty liver disease was the leading etiology for liver cirrhosis (47%). Delisting/death on the waiting list was higher among patients with BS (33.3% versus 10.1%; P = 0.002), and the transplantation rate was lower (48.9% versus 65.2%; P = 0.03). Intention-to-treat (ITT) survival from listing to 1 year after LT was lower in the BS cohort versus concurrent cohort (1-year survival, 84% versus 90%; P = 0.05). On adjusted analysis, a history of BS was associated with an increased risk of death on the waiting list (hazard ratio [HR], 5.7; 95% confidence interval [CI], 2.2-15.1), but this impact was attenuated (HR, 4.9; 95% CI, 1.8-13.4) by the presence of malnutrition. When limited to matched controls by sex, mortality attributed to BS was no longer significant for females (P = 0.37) but was significant for males (P = 0.046). Sarcopenia, as captured by skeletal muscle index, was calculated in a subset of patients (n = 49). The total skeletal surface area was lower in the BS group (127 [105-141] cm(2) versus 153 [131-191] cm(2) ; P = 0.005). Rates of sarcopenia were higher among patients delisted after listing (71.4% versus 16.7%; P = 0.04). In conclusion, a history of BS was associated with higher rates of delisting on the waiting list as well as lower survival from the time of listing on ITT analysis. Presence of malnutrition and sarcopenia among patients with BS may contribute to worse outcomes.

Harmon, D. M., K. M. Tecson, B. Lima, J. D. G. Collier, A. F. Shaikh, S. Still, R. D. Baxter, N. Lew, R. Thakur, J. Felius, S. A. Hall, G. V. Gonzalez-Stawinski and S. M. Joseph (2019). “Outcomes of Moderate-to-Severe Acute Kidney Injury following Left Ventricular Assist Device Implantation.” Cardiorenal Med 9(2): 100-107.

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BACKGROUND: Although acute kidney injury (AKI) is a common complication following cardiac surgery, less is known about the occurrence and consequences of moderate/severe AKI following left ventricular assist device (LVAD) implantation. METHODS: All patients who had an LVAD implanted at our center from 2008 to 2016 were reviewed to determine the incidence of, and risk factors for, moderate/severe (stage 2/3) AKI and to compare postoperative complications and mortality rates between those with and those without moderate/severe AKI. RESULTS: Of 246 patients, 68 (28%) developed moderate/severe AKI. A multivariable logistic regression comprising body mass index and prior sternotomy had fair predictive ability (area under the curve = 0.71). A 1-unit increase in body mass index increased the risk of moderate/severe AKI by 7% (odds ratio = 1.07; 95% confidence interval: 1.03-1.11); a prior sternotomy increased the risk more than 3-fold (odds ratio = 3.4; 95% confidence interval: 1.84-6.43). The group of patients with moderate/severe AKI had higher rates of respiratory failure and death than the group of patients with mild/no AKI. Patients with moderate/severe AKI were at 3.2 (95% confidence interval: 1.2-8.2) times the risk of 30-day mortality compared to those without. Even after adjusting for age and Interagency Registry for Mechanically Assisted Circulatory Support profile, those with moderate/severe AKI had 1.75 (95% confidence interval: 1.03-3.0) times the risk of 1-year mortality compared to those without. DISCUSSION: Risk-stratifying patients prior to LVAD placement in regard to AKI development may be a step toward improving surgical outcomes.