Readmission Following Gastric Cancer Resection: Risk Factors and Survival

Background

This study utilized a multi-institutional database to evaluate risk factors for readmission in patients undergoing curative gastrectomy for gastric adenocarcinoma with the intent of describing both perioperative risk factors and the relationship of readmission to survival.

Methods

Patients who underwent curative resection of gastric adenocarcinoma from 2000 to 2012 from seven academic institutions of the US Gastric Cancer Collaborative were analyzed. In-hospital deaths and palliative surgeries were excluded, and readmission was defined as within 30 days of discharge. Univariate and multivariable logistic regression analyses were employed and survival analysis conducted.

Results

Of the 855 patients, 121 patients (14.2 %) were readmitted. Univariate analysis identified advanced age (p?<?0.0128), American Society of Anesthesiology status ≥3 (p?=?0.0045), preexisting cardiac disease (p?<?0.0001), hypertension (p?=?0.0142), history of smoking (p?=?0.0254), increased preoperative blood urea nitrogen (BUN; p?=?0.0426), concomitant pancreatectomy (p?=?0.0056), increased operation time (p?=?0.0384), estimated blood loss (p?=?0.0196), 25th percentile length of stay (<7 days, p?=?0.0166), 75th percentile length of stay (>12 days, p?=?0.0256), postoperative complication (p?<?0.0001), and total gastrectomy (p?=?0.0167) as risk factors for readmission. Multivariable analysis identified cardiac disease (odds ratio (OR) 2.4, 95 % confidence interval (CI) 1.6–3.3, p?<?0.0001), postoperative complication (OR 2.3, 95 % CI 1.6–5.4, p?<?0.0001), and pancreatectomy (OR 2.2, 95 % CI 1.1–4.1, p?=?0.0202) as independent risk factors for readmission. There was an association of decreased overall median survival in readmitted patients (39 months for readmitted vs. 103 months for non-readmitted). This was due to decreased survival in readmitted stage 1 (p?=?0.0039), while there was no difference in survival for other stages. Stage I readmitted patients had a higher incidence of cardiac disease than stage I non-readmitted patients (58 vs. 24 %, respectively, p?=?0.0002).

Conclusions

Within this multi-institutional study investigating readmission in patients undergoing curative resection for gastric cancer, cardiac disease, postoperative complication, and concomitant pancreatectomy were identified as significant risk factors for readmission. Readmission was associated with decreased overall median survival, but on further analysis, this was driven by differences in survival for stage I disease only.

     

Simplified CLARITY for visualizing immunofluorescence labeling in the developing rat brain

CLARITY is an innovative technological advance in which intact biological tissue is transformed into a “nanoporous hydrogel-hybridized form” (Chung et al. 2013; Chung and Deisseroth 2013) with markedly improved chemical and optical accessibility, permitting fluorescent visualization and extraction of high-resolution structural data from mm-thick blocks of tissue. CLARITY affords an excellent but as yet unexploited opportunity to visualize the growth and maturation of phenotypically identified neurons and axonal processes in the developing brain. This brief report describes a moderately revised, simplified, and less expensive CLARITY protocol that effectively reveals the structure of chemically identified neurons in whole neonatal/juvenile rat brains and tissue slabs. Rats [postnatal day (P)0–24] were transcardially perfused with one of two fixative/hydrogel solutions, followed by hydrogel polymerization to generate brain hybrids. Whole brain hybrids or 2.0-mm-thick coronal slabs were passively cleared of lipid and then processed for dual immunofluorescence labeling, including labeling using tyramide signal amplification. After refractive index matching using 2,20-Thiodiethanol (60 % solution), a Leica confocal microscope equipped with a CLARITY objective was used to view the hypothalamus in whole brain hybrids or slabs. Collected image stacks revealed the distribution and three-dimensional structure of hypothalamic pro-oxyphysin (oxytocin)-, neuropeptide Y-, glucagon-like peptide-1-, and tyrosine hydroxylase-immunopositive neurons and processes within large tissue volumes. Outstanding structural preservation and immunolabeling quality demonstrates the efficacy of this approach for interrogating chemically defined neural circuits as they develop in postnatal rodent brain.     

Assessment of the kinetics of Treponema pallidum dissemination into blood and tissues in experimental syphilis by real-time quantitative PCR

Little is known about the size and kinetics of treponemal burdens in blood and tissues during acquired or experimental syphilitic infection. We used real-time quantitative PCR to measure Treponema pallidum DNA levels in rabbits infected intratesticularly with the prototype Nichols strain. At the outset, we performed a series of in vitro blood spiking experiments to determine the effect of blood processing procedures on the distribution of treponemes in various blood components. T. pallidum DNA levels in plasma and whole blood were approximately 10-fold higher than those in serum and more than 200-fold greater than those in peripheral blood mononuclear cells (PBMCs). Ten rabbits were inoculated intratesticularly with doses of treponemes ranging from 4 x 10(7) to 2 x 10(8) organisms. In five rabbits, T. pallidum DNA levels were measured sequentially in serum, plasma, whole blood, and PBMCs until sacrifice at peak orchitis, at which time brain, kidney, liver, spleen, and testicles were harvested; blood and organs were also harvested at orchitis from the other five rabbits. T. pallidum DNA was detected in plasma within 24 h postinfection. Treponeme levels in whole blood and blood components increased significantly with the development of peak orchitis. Overall, levels in serum and PBMCs were lower than those in plasma and whole blood; this disparity was particularly marked at early time points. Significantly greater numbers of spirochetes were found in the spleen than in liver, kidney, or brain tissue at the time of sacrifice. Our findings highlight the remarkable capacity of T. pallidum to disseminate from the site of infection to blood and tissues, and they identify the spleen as a prime target for treponemal invasion.