High reproducibility of histological characterization by whole virtual slide quantification; an example using carotid plaque specimens.

OBJECTIVE: Tissue biobanks are an important source for discovery and validation studies aiming for new proteins that are causally related with disease development. There is an increasing demand for accurate and reproducible histological characterization, especially for subsequent analysis and interpretation of data in association studies. We assessed reproducibility of one semiquantative and two quantitative methods for histological tissue characterization. We introduce a new automated method for whole digital slide quantification. Carotid atherosclerotic plaques were used to test reproducibility. METHODS: 50 atherosclerotic plaques that were obtained during carotid endarterectomy were analysed. For the semiquantitative analysis, 6 different plaque characteristics were scored in categories by two independent observers, and Cohen's κ was used to test intra- and interobserver reproducibility. The computer-aided method (assessed by two independent observers) and automated method were tested on CD68 (for macrophages) and α smooth muscle actin (for smooth muscle cells) stainings. Agreement for these two methods (done on a continuous scale) was assessed by intraclass correlation coefficients (ICCs). RESULTS: For the semiquantitative analysis, κ values ranged from 0.55 to 0.69 for interobserver variability, and were slightly higher for intraobserver reproducibility in both observers. The computer-aided method yielded intra- and interobserver ICCs between 0.6 and 0.9. The new automated method performed most optimal regarding reproducibility, with ICCs ranging from 0.92 to 0.97. CONCLUSIONS: The analysis of performance of three methods for histological slide characterization on carotid atherosclerotic plaques showed high precision and agreement in repeated measurements for the automated method for whole digital slide quantification. We suggest that this method can fulfill the need for reproducible histological quantification.

Postoperative pain during the first week after adenoidectomy and guillotine adenotonsillectomy in children.

BACKGROUND: Adenoidectomy (AD) and adenotonsillectomy (ATE) are frequently occurring and often painful interventions in children. In literature, it is very prevalent that postoperative pain in children following ATE is hard to control. The purpose of this study was to evaluate the prevalence and severity of postoperative pain in children undergoing AD and ATE in the ambulatory setting. METHODS: A prospective cohort study was performed including 167 children aged 0-12 years, undergoing AD using an adenotome and ATE using the guillotine technique in day care. Children undergoing AD received acetaminophen pre- and postoperatively. Children undergoing ATE received acetaminophen and diclofenac preoperatively, sufentanyl postoperative and a prescription of around-the-clock treatment with acetaminophen and diclofenac at home. Pain intensity and analgesic consumption were recorded in hospital using the Faces, Legs, Activity, Cry and Consolability-scale (FLACC), as well as during a 1-week follow-up period at home using the Parents' Postoperative Pain Measure (PPPM) and Visual Analogue Scale (VAS) scores. RESULTS: All children left the recovery room with adequate pain scores and were discharged with a median VAS of two after ATE and one after AD. The PPPM and VAS scores were highest at the first measurement at home for AD patients (VAS = 2.0 and PPPM = 1.5) and ATE patients (VAS = 4.5 and PPPM = 9). On the second postoperative day, AD patients scored 0.0 points on both VAS and PPPM. ATE patients scored at that time 3.0 point on the VAS and 6.0 points using the PPPM. Despite high adherence to pain treatment, daytime activities normalized after an average of 2 and 7 days after AD and ATE, respectively. CONCLUSION: Examination of the PPPM and VAS scores illustrated that children undergoing AD were comfortable with acetaminophen as a single analgesic, whereas children undergoing ATE experience significant pain for up to two postoperative days when treated with acetaminophen and diclofenac.