The Endoscopy Patient as a Vector and Victim.

Patient and procedural factors can increase the risk of infectious adverse events during endoscopy. Prophylactic antibiotic use must be judicious and individualized in the era of antibiotic resistance. New and emerging procedures require high-quality studies to elucidate appropriate risk profiles.

Endoscopic ultrasound versus computed tomography in determining the resectability of pancreatic cancer: A diagnostic test accuracy meta-analysis.

BACKGROUND/AIM: Endoscopic ultrasound (EUS) and contrast-enhanced computed tomography (CT) with pancreas protocol are used in assessing the resectability of neoplastic pancreatic lesions. Here, we performed a diagnostic test accuracy (DTA) meta-analysis, comparing the diagnostic accuracy of EUS and CT in evaluating the resectability of pancreatic cancer using surgical assessment as the reference standard. PATIENTS AND METHODS: A comprehensive electronic search was conducted up to March 2020. Studies comparing EUS and CT in assessing the resectability of pancreatic cancer using surgical assessment as reference standard were included. QUADAS-2 tool was used to assess the quality of the included studies. After data extraction, an analysis was done using DerSimonian Laird method (random-effects model) to estimate the overall diagnostic odds ratio (DOR) and determine the best-fitting receiver operating characteristics (ROC) curve. RESULTS: Two studies, with 77 subjects combined, were included in the analysis. Overall, the risk of bias was moderate. EUS and CT were comparable in determining the resectability of pancreatic cancer with AUC = 75% (95% confidence interval (CI) 66%- 84%) for EUS as compared to 78% (95% CI 69%- 87%) for CT (P > 0.05). Pooled sensitivity and specificity was 87% (95% CI 70%- 96%) and 63% (95% CI 48%- 77%), respectively for EUS and 87% (95% CI 70%- 96%) and 70% (95% CI 55%- 83%), respectively for CT. DOR was 11.51 (95% CI 3.55- 36.81) for EUS as compared to 15.91 (95% CI 4.83- 51.62) for CT (P > 0.05). CONCLUSIONS: Both EUS and CT provide reasonable sensitivity and specificity to detect the resectability of pancreatic cancer.

Resident Survey on Gastroenterology Training in Canada.

BACKGROUND: Gastroenterology training in Canada is guided by the Royal College of Physicians and Surgeons of Canada. Resident perspectives on training and the degree of heterogeneity across training programs have not been previously surveyed. AIM: This study aims to evaluate the current Canadian adult gastroenterology training experience from a resident perspective and provide insight into the heterogeneity among training programs. METHOD: A survey designed by three current gastroenterology residents was distributed to trainees attending the Gastroenterology Residents-in-Training course at Canadian Digestive Diseases Week 2018. Categorical data from the survey was analyzed in table format. Other continuous data was converted to dichotomous data and analyzed in groups of small and large programs, the large program defined as greater than six trainees. RESULTS: The overall response rate was 45 of 56 (80%), representing 13 of 14 accredited training sites. Mandatory rotations and core procedures varied widely across respondents, with only inpatient training consistent across all sites. Small programs had a higher call burden (P=0.039), but staff were more likely to be available to cover call if the resident coverage was unavailable (P=0.002). There were nonsignificant trends in small programs in the inability to take a post-call day (P=0.07) and a resident perception of being well trained (P=0.07). CONCLUSIONS: There is heterogeneity across programs in mandatory rotations and core procedures. With the upcoming shift to competency-based medical education, it is an opportune time to re-evaluate and perhaps standardize how gastroenterology training is delivered in Canada.

EUS versus magnetic resonance imaging in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis.

BACKGROUND AND AIMS: EUS and magnetic resonance imaging (MRI) are both used for locoregional staging of rectal cancer, which determines treatment options. There is a lack of consensus on the best modality for locoregional staging, with studies supporting both EUS and MRI. In this study, we performed the first diagnostic test accuracy meta-analysis to compare the diagnostic accuracy, sensitivity, and specificity of EUS and MRI in the staging of rectal cancer. METHODS: A comprehensive electronic literature search up to June 2018 was performed to identify prospective cohort studies directly comparing the accuracy of EUS with MRI in staging nonmetastatic rectal cancer with surgical pathology as the reference standard. Quality of the included studies was measured by using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. A bivariate hierarchical model was used to perform the meta-analysis of diagnostic test accuracy according to the Cochrane approved methodology. Summary receiver operating characteristics were developed, and the area under the curve was calculated for overall and individual T and N staging, for EUS, MRI, and head-to-head comparison. RESULTS: Six of 2475 studies including 234 patients were eligible. Pooled sensitivity and specificity in T staging were .79 (95% confidence interval [CI], .72-.85) and .89 (95% CI, .84-.93) for EUS and .79 (95% CI, .72-.85) and .85 (95% CI, .79-.90) for MRI, respectively. Pooled sensitivity and specificity in N staging were .81 (95% CI, .71-.89) and .88 (95% CI, .80-.94) for EUS and .83 (95% CI, .73-.90), and .90 (95% CI, .82-.95) for MRI, respectively. In area under the curve head-to-head analysis, EUS was superior to MRI in overall T staging (P < .05). EUS outperformed MRI in overall T, overall N, T1, and T3 staging (P < .01), after excluding studies using an endorectal coil for MRI. MRI was superior to EUS in T2 staging (P = .01) in both analyses. CONCLUSIONS: EUS and MRI both provide reasonable diagnostic accuracy in the staging of nonmetastatic rectal cancer. EUS was superior to MRI in overall T staging and overall T and N staging after adjusting for MRI technology. Practitioners should be aware of advantages and disadvantages of both modalities and choose appropriate methods while considering diagnostic accuracy of each test and institutional practices and limitations.

Adenocarcinoma Arising from a Gastric Duplication Cyst.

Gastric duplication cysts are rare congenital anomalies, and malignant transformation has only been reported in 11 cases. A healthy 57-year-old woman presented with abdominal discomfort, and computed tomography revealed a 5.8 × 6.6 × 8.2 cm mass at the gastric fundus. On endoscopic ultrasound, the mass was mostly hypoechoic with anechoic cystic cavities arising from the submucosal layer. Fine-needle aspiration was suspicious for adenocarcinoma. Surgical pathology confirmed high-grade adenocarcinoma, clear cell cytology arising from a foregut duplication cyst. Endoscopic ultrasound is underutilized in the evaluation duplication cysts and should be considered in routine workup.

Patient comfort scores do not affect endoscopist behavior during colonoscopy, while trainee involvement has negative effects on patient comfort.

INTRODUCTION: Patient comfort is an important part of endoscopy and reflects procedure quality and endoscopist technique. Using the validated, Nurse Assisted Patient Comfort Score (NAPCOMS), this study aimed to determine whether the introduction of NAPCOMS would affect sedation use by endoscopists. PATIENTS AND METHODS: The study was conducted over 3 phases. Phase One and Two consisted of 8 weeks of endoscopist blinded and aware data collection, respectively. Data in Phase Three was collected over a 5-month period and scores fed back to individual endoscopists on a monthly basis. RESULTS: NAPCOMS consists of 3 domains - pain, sedation, and global tolerability. Comparison of Phase One and Two, showed no significant differences in sedative use or NAPCOMS. Phase Three data showed a decline in fentanyl use between individual months ( P  = 0.035), but no change in overall NAPCOMS. Procedures involving trainees were found to use more midazolam ( P  = 0.01) and fentanyl ( P  = 0.01), have worse NAPCOMS scores, and resulted in longer procedure duration ( P  < 0.001). Data comparing gastroenterologists and general surgeons showed increased fentanyl use ( P  = 0.037), decreased midazolam use ( P  = 0.001), and more position changes ( P  = 0.002) among gastroenterologists. CONCLUSIONS: The introduction of a patient comfort scoring system resulted in a decrease in fentanyl use, although with minimal clinical significance. Additional studies are required to determine the role of patient comfort scores in quality control in endoscopy. Procedures completed with trainees used more sedation, were longer, and had worse NAPCOMS scores, the implications of which, for teaching hospitals and training programs, will need to be further considered.

Spontaneous regression of metastatic pulmonary renal cell carcinoma in the setting of sarcomatoid differentiation of the primary tumour.

We present a case of spontaneous regression of pulmonary metastases from renal cell carcinoma (RCC) with sarcomatoid differentiation, prior to intervention. The patient presented with conventional type RCC with Furhman Grade 4/4 and sarcomatoid differentiation, complicated by pulmonary metastases. Palliative systemic therapy was planned, but prior to the onset of treatment, serial computed tomography scans demonstrated regression of metastatic disease. Spontaneous regression of metastases is rare, but well-documented in conventional clear cell RCC. To the best of our knowledge, this has not previously been described in the setting of sarcomatoid differentiation of the primary tumour.

On the catalysis of calcium oxalate dihydrate formation by osteopontin peptides.

Inhibition of calcium oxalate monohydrate (COM) formation and initiation of the dihydrate (COD) phase by osteopontin (OPN) have been proposed to play an important role in preventing kidney stone formation. We have studied the roles of OPN phosphate and carboxylate groups in the modulation of calcium oxalate (CaOx) crystallization using synthetic peptides corresponding to residues 65-80, 129-144, 220-235 and 273-288 of rat OPN. We investigated the effects of these peptides (0-20 µg/ml) on COM and COD formation by correlating qualitative and quantitative microscopic data with the physicochemical characteristics of the peptides used. In general, highly acidic/hydrophilic peptides strongly inhibit COM and promote COD formation. However, OPN129-144, which is basic, and OPN273-288, which is only slightly acidic, also induced COD precipitation. It is likely that inhibition of nucleation and/or growth of COM by OPN peptides maintains a high supersaturation, thereby allowing formation of the more-soluble dihydrate polymorph. In addition, growth of COD from the substrate in <100>/<110> directions suggests that highly acidic OPN peptides may nucleate crystals from the Ca(2+)-rich {100}/{110} faces. At higher peptide concentrations, however, peptides containing either phosphates or contiguous carboxylates inhibit COD, whereas peptides containing both promote COD formation further.

Cooperation of phosphates and carboxylates controls calcium oxalate crystallization in ultrafiltered urine.

Osteopontin (OPN) is one of a group of proteins found in urine that are believed to limit the formation of kidney stones. In the present study, we investigate the roles of phosphate and carboxylate groups in the OPN-mediated modulation of calcium oxalate (CaOx), the principal mineral phase found in kidney stones. To this end, crystallization was induced by addition of CaOx solution to ultrafiltered human urine containing either human kidney OPN (kOPN; 7 consecutive carboxylates, 8 phosphates) or synthesized peptides corresponding to residues 65-80 (pSHDHMDDDDDDDDDGD; pOPAR) or 220-235 (pSHEpSTEQSDAIDpSAEK; P3) of rat bone OPN. Sequence 65-80 was also synthesized without the phosphate group (OPAR). Effects on calcium oxalate monohydrate (COM) and dihydrate (COD) formation were studied by scanning electron microscopy. We found that controls form large, partly intergrown COM platelets; COD was never observed. Adding any of the polyelectrolytes was sufficient to prevent intergrowth of COM platelets entirely, inhibiting formation of these platelets strongly, and inducing formation of the COD phase. Strongest effects on COM formation were found for pOPAR and OPAR followed by kOPN and then P3, showing that acidity and hydrophilicity are crucial in polyelectrolyte-affected COM crystallization. At higher concentrations, OPAR also inhibited COD formation, while P3, kOPN and, in particular, pOPAR promoted COD, a difference explainable by the variations of carboxylate and phosphate groups present in the molecules. Thus, we conclude that carboxylate groups play a primary role in inhibiting COM formation, but phosphate and carboxylate groups are both important in initiating and promoting COD formation.