Effect of referral pattern and histopathology grade on surgery for nonmalignant colorectal polyps.

BACKGROUND AND AIMS: The incidence of surgery for nonmalignant colorectal polyps is rising. The aims of this study were to evaluate referral patterns to surgery for nonmalignant polyps, to compare outcomes between surgery and endoscopic resection (ER), and to identify factors associated with surgery in a university-based, tertiary care center. METHODS: Patients referred to colorectal surgery (CRS) for nonmalignant colorectal polyps between 2014 and 2019 were selected from the institution's integrated data repository. Clinical characteristics were obtained through chart review. Multivariate analysis was performed to identify factors associated with surgery for nonmalignant polyps. RESULTS: Six hundred sixty-four patients with colorectal lesions were referred to CRS, of which 315 were for nonmalignant polyps. Most referrals (69%) came from gastroenterologists. Of the 315 cases, 136 underwent surgery and 117 were referred for attempt at ER. Complete ER was achieved in 87.2% (n = 102), with polyp recurrence in 27.2% at a median of 14 months (range, 0-72). When compared with surgery, ER was associated with a lower hospitalization rate (22.2% vs 95.6%; P < .0001), shorter hospital stay (mean, .5 ± .9 vs 2.23 ± 1 days; P < .0001), and fewer adverse events (5.9% vs 22.8%; P = .0002). Intramucosal adenocarcinoma on baseline pathology (odds ratio, 5.7; 95% confidence interval, 1.2-28.2) and referrals by academic gastroenterologists (odds ratio, 2.5; 95% confidence interval, 1.11-5.72) were associated with a higher likelihood of surgery on multivariate analysis. CONCLUSIONS: Gastroenterologists commonly refer nonmalignant colorectal polyps to surgery, even though ER is effective and associated with lower morbidity. Both referrals from academic gastroenterologists and baseline pathology of intramucosal adenocarcinoma were factors associated with surgery. All colorectal polyps should be evaluated in a multidisciplinary approach to identify lesions suitable for ER before embarking in surgery.

Histologic Analysis of Endoscopic Ultrasound-Guided Through the Needle Microforceps Biopsies Accurately Identifies Mucinous Pancreas Cysts.

BACKGROUND & AIMS: It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs. METHODS: We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available. RESULTS: The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P < .001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P < .001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P < .001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P < .001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P = .04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%). CONCLUSIONS: In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA-even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509.

Impact of Endotracheal Intubation on Interventional Endoscopy Unit Efficiency Metrics at a Tertiary Academic Medical Center.

OBJECTIVES: Measures for evaluating interventional endoscopy unit efficiency have not been adequately validated, especially in reference to the involvement of anesthesia services for endoscopy. Primary aim was to compare process measures/metrics of interventional endoscopy unit efficiency between intubated and non-intubated patients. Secondary aim was to assess variables associated with the need for endotracheal intubation. METHODS: The prospectively collected endoscopy unit metrics database at UF Health was reviewed for procedures performed in the interventional endoscopy unit for 6 months. Parameters included hospital-mandated metrics available from the database. RESULTS: A total of 1,421 patients underwent 1,635 interventional endoscopic procedures and 271/1,421 patients (19.1%) were intubated. There was no significant difference between intubated and non-intubated cohorts with respect to age, gender, BMI, ASA Score, Mallampati Score, or the Charlson Comorbidity Index. Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) were more frequently intubated than those undergoing non-ERCP procedures (41.3 vs. 12.4%, P<0.0001). Inpatients comprised 48.3% of all intubated patients, whereas only 29.2% of non-intubated patients were inpatients (P<0.0001). Most patients (159/271, 58.7%) were intubated per anesthesiologist preference. All process efficiency metrics were significantly prolonged in the intubated compared with the non-intubated patient cohort, except the time interval between successive procedures. Multivariate analysis revealed that patients with an anesthesiologist who had performed a greater number of total endoscopic sedations were less likely to be intubated than patients with an anesthesiologist who had performed fewer total procedures (P=0.0066). CONCLUSIONS: Endotracheal intubation negatively impacts efficiency metrics in an interventional endoscopy unit. Careful assessment for the need for intubation should be emphasized.

Utility of clinical suspicion and endoscopic re-examination for detection of esophagogastric perforation after pneumatic dilation for achalasia.

BACKGROUND AND STUDY AIMS: Esophagrams are often obtained routinely after pneumatic balloon dilation for achalasia, even in asymptomatic patients, as there is a risk of postprocedure esophagogastric perforation, which is a potentially life-threatening complication. The aim of this study was to determine whether the combination of a clinical suspicion of perforation and endoscopic re-examination after pneumatic dilation for achalasia can detect esophagogastric perforation, and thereby preclude the need for routine esophagrams in all patients. PATIENTS AND METHODS: All patients who underwent pneumatic dilation between January 2002 and June 2012 at our single tertiary referral center were identified retrospectively. Procedures were categorized into two groups: Group 1 underwent routine esophagograms after pneumatic dilation, and Group 2 underwent esophagograms only if there was a clinical suspicion of perforation. The detection rate of esophageal perforation after pneumatic dilation was compared between the two groups. RESULTS: A total of 119 achalasia dilation procedures were performed in 70 patients. Group 1 included 49/119 procedures (41.2 %), all of which were followed by routine esophagograms. Group 2 included 70/119 procedures (58.8 %), 12 of which were followed by esophagograms based on a clinical suspicion of perforation. No esophageal perforations were found in Group 1, whereas three were found in Group 2. No perforations occurred in the 58 procedures that were not followed by esophagograms. The overall rate of perforation was 3/119 (2.5 %). CONCLUSIONS: Esophagrams obtained routinely after pneumatic dilation for achalasia did not reveal unsuspected esophagogastric perforations. No esophageal perforations were missed after procedures that were not followed by esophagograms. Obtaining an esophagram only in cases of clinical suspicion of perforation and endoscopic evaluation may be an alternative to routine esophagograms in patients undergoing pneumatic dilation for achalasia.

Chronic pancreatitis.

PURPOSE OF REVIEW: We review selected important clinical observations in chronic pancreatitis reported in 2013. RECENT FINDINGS: Early diagnosis of chronic pancreatitis remains difficult, although newer techniques utilizing endoscopic ultrasonography-elastography and MRI hold promise. Patients with chronic pancreatitis are at risk of nutritional deficiencies. Osteoporosis, osteopenia, and bone fracture are particularly common in these patients, and require active intervention and treatment. Diabetes caused by chronic pancreatitis, type 3c diabetes, has specific characteristics and requires careful management. Antioxidants and neuromodulators may decrease pain in some patients with chronic pancreatitis. Endoscopic treatment is effective and can be utilized in patients with painful chronic pancreatitis, although randomized trials demonstrate that surgical therapy is somewhat more durable and effective. Although surgery has typically been a last resort, some advocate early surgical intervention but the optimal time remains unknown. SUMMARY: Early diagnosis of pancreatitis may be improved by newer techniques associated with endoscopic ultrasonography imaging. Treatment of nutritional deficiencies and diabetes is an important aspect of treating chronic pancreatitis. Pain relief with adjunct means of pain modulation should be tried before starting narcotics for pain control. Endoscopic therapy is appropriate for treating chronic pancreatitis and its local complications and surgical intervention can be considered early in carefully selected individuals.

Safety of cold resection of non-ampullary duodenal polyps: Systematic review and meta-analysis.

Background and study aims Endoscopic resection has traditionally involved electrosurgical cautery (hot snare) to resect premalignant polyps. Recent data have suggested superior safety of cold resection. We aimed to assess the safety of cold compared with traditional (hot) resection for non-ampullary duodenal polyps. Methods We performed a systematic review ending in September 2022. The primary outcome of interest was the adverse event (AE) rate for cold compared with hot polyp resection. We reported odds ratios with 95% confidence intervals (CIs). Secondary outcomes included rates of polyp recurrence and post-polypectomy syndrome. We assessed publication bias with the classic fail-safe test and used forest plots to report pooled effect estimates. We assessed heterogeneity using I 2 index. Results Our systematic review identified 1,215 unique citations. Eight of these met inclusion criteria, seven of which were published manuscripts and one of which was a recent meeting abstract. On random effect modeling, cold resection was associated with significantly lower odds of delayed bleeding compared with hot resection. The difference in the odds of perforation (odds ratio [OR] 0.31 [95% confidence interval [CI] 0.05-2.87], P =0.2, I 2 =0) and polyp recurrence (OR 0.75 [95% CI 0.15-3.73], P =0.72, I 2 =0) between hot and cold resection was not statistically significant. There were no cases of post-polypectomy syndrome reported with either hot or cold techniques. Conclusions Cold resection is associated with lower odds of delayed bleeding compared with hot resection for duodenal tumors. There was a trend toward higher odds of perforation and recurrence following hot resection, but this trend was not statistically significant.

Diagnostic accuracy of conventional and cholangioscopy-guided sampling of indeterminate biliary lesions at the time of ERCP: a prospective, long-term follow-up study.

BACKGROUND: The diagnostic accuracy of cholangioscopy-guided sampling has not been rigorously evaluated. OBJECTIVE: To prospectively evaluate the accuracy of cholangioscopy-guided mini-forceps sampling and compare it with standard cytology brushings and forceps biopsies for the tissue diagnosis of indeterminate biliary lesions. DESIGN: Prospective, long-term follow-up, paired design cohort study. SETTING: Tertiary center. PATIENTS: Patients undergoing cholangioscopy for the evaluation of indeterminate biliary lesions. INTERVENTIONS: Each patient underwent triple sampling with cholangioscopy-guided mini-forceps, cytology brushing, and standard forceps. MAIN OUTCOME MEASUREMENTS: Diagnostic accuracy of each sampling method compared with the patient final status (cancer vs no cancer). RESULTS: A total of 26 patients (17 cancer positive/9 cancer negative) were enrolled. The mean follow-up in the patients with no cancer was 21.78 (SD ±6.78) months. The procedure was technically successful in all cases (100%). Sample quality was adequate in 25 of 26 (96.2%) of the cytology brushings, in 26 of 26 (100%) of the standard forceps biopsies, and in 25 of 26 (96.2%) of the mini-forceps biopsies. The sensitivity, accuracy, and negative predictive values were 5.9%, 38.5%, and 36% for standard cytology brushings; 29.4%, 53.8%, and 42.8% for standard forceps biopsies; and 76.5%, 84.6%, and 69.2% for mini-forceps biopsies, respectively. When comparing the 3 methods of sampling, mini-forceps biopsy provided significantly better sensitivity and overall accuracy compared with standard cytology brushing (P < .0001) and standard forceps biopsy (P = .0215). LIMITATIONS: Potential for selection bias. CONCLUSIONS: Cholangioscopy-guided biopsies of indeterminate biliary lesions have significantly higher accuracy compared with ERCP-guided cytology brushings and standard forceps biopsies, but negative findings on mini-forceps biopsy cannot rule out malignancy with a high degree of certainty. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01227382.).

Modulating malignant epithelial tumor cell adhesion, migration and mechanics with nanorod surfaces.

The failure of tumor stents used for palliative therapy is due in part to the adhesion of tumor cells to the stent surface. It is therefore desirable to develop approaches to weaken the adhesion of malignant tumor cells to surfaces. We have previously developed SiO2 coated nanorods that resist the adhesion of normal endothelial cells and fibroblasts. The adhesion mechanisms in malignant tumor cells are significantly altered from normal cells; therefore, it is unclear if nanorods can similarly resist tumor cell adhesion. In this study, we show that the morphology of tumor epithelial cells cultured on nanorods is rounded compared to flat surfaces and associated with decreased cellular stiffness and non-muscle myosin II phosphorylation. Tumor cell viability and proliferation was unchanged on nanorods. Adherent cell numbers were significantly decreased while single tumor cell motility was increased on nanorods compared to flat surfaces. Together, these results suggest that nanorods can be used to weaken malignant tumor cell adhesion, and therefore potentially improve tumor stent performance.

Fully covered Alimaxx esophageal metal stents in the endoscopic treatment of benign esophageal diseases.

BACKGROUND: Expandable esophageal stents are widely used for the palliation of dysphagia in patients with esophageal cancer and are also beginning to be used in patients with benign esophageal diseases such as refractory strictures and fistulas. There is concern regarding the increased risk of migration of the fully covered Alimaxx metal esophageal stent and experience with this stent in benign esophageal pathology has been reported in only a small series of patients. AIMS: To evaluate the technical success in placement and removal, efficacy and complications of the Alimaxx esophageal stent for benign esophageal diseases. METHODS: Our endoscopy database was retrospectively reviewed from 1/2003 to 2/2009 to identify patients with Alimaxx esophageal stent placement for benign diseases. Chart review was performed for age, gender, indication, site of the lesion, success of placement, outcome, and incidence of complications. RESULTS: Twenty-eight stents were successfully placed in 14 patients with benign esophageal diseases (mean: two stents/patient; range 1-7). Indications included esophageal fistula in seven (50%) and benign strictures in 7/14 (50%). Dysphagia improved in all patients while the fistula resolved in 6/7 (85.8%) patients. Complications related to stents included pain (2/28, 7%), stent related gastric ulcer (1/28, 4%), nausea and vomiting (3/21, 11%) and stent migration (11/28, 39%). All migrated stents were successfully endoscopically retrieved. CONCLUSIONS: The fully covered and removable Alimaxx stent is effective in the endoscopic management of benign esophageal strictures or fistulas, despite its relatively high rate of migration. Stent migration was successfully managed endoscopically without complications.

First Reported Case of Endoscopic Ultrasound-Guided Core Biopsy Yielding Diagnosis of Primary Adrenal Leiomyosarcoma.

Primary adrenal leiomyosarcoma (PAL) is an extremely rare mesenchymal tumor with only a few isolated case reports in the medical literature. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) or endoscopic ultrasound-guided core biopsy (EUS-CB) is a safe, effective modality for sampling lesions in the gastrointestinal tract and adjacent organs, including the adrenal glands. We describe the case of a 50-year-old male presenting with abdominal pain and unintentional weight loss over the course of one year. CT imaging revealed an 8.1 cm heterogeneous left adrenal mass with PET-confirmed metastases to the liver and lung. Pheochromocytoma was ruled out. Adrenal cortical carcinoma was the other critical differential diagnosis. As the patient was not a candidate for surgery, an EUS-FNA and CB were performed on this left adrenal mass revealing a spindle cell neoplasm with extensive necrosis confirming the diagnosis of primary leiomyosarcoma. The patient was treated with chemotherapy with palliative radiation. This case demonstrates the utility of EUS-FNA or CB as modalities that can aid in the diagnosis of adrenal lesions in specific circumstances.

Adherence to quality indicators and surveillance guidelines in the management of Barrett's esophagus: a retrospective analysis.

BACKGROUND: Adherence to quality indicators and surveillance guidelines in the management of Barrett's esophagus (BE) promotes high-quality, cost-effective care. The aims of this study were (1) to evaluate adherence to standardized classification (Prague Criteria) and systematic (four-quadrant) biopsy protocol, (2) to identify predictors of practice patterns, and (3) to assess adherence to surveillance guidelines for non-dysplastic BE (NDBE). METHODS: This was a single-center retrospective study of esophagogastroduodenoscopy (EGD) performed for BE (June 2008 to December 2015). Patient demographics, procedure characteristics, and histology results were obtained from the procedure report-generating database and chart review. Adherence to Prague Criteria and systematic biopsies was based on operative report documentation. Multiple logistic regression analysis was performed to identify predictors of practice patterns. Guideline adherent surveillance EGD was defined as those performed within 6 months of the recommended 3- to 5-year interval. RESULTS: In total, 397 patients (66.5 % male; mean age 60.1 ±â€Š12.5 years) had an index EGD during the study period. Adherence to Prague Criteria and systematic biopsies was 27.4 % and 24.1 %, respectively. Endoscopists who performed therapeutic interventions for BE were more likely to use the Prague Criteria (OR: 3.16; 95 %CI: 1.47 - 6.82; P  < 0.01) than those who did not. Longer time in practice was positively associated with adherence to Prague Criteria (OR 1.07; 95 %CI: 1.02 - 1.12; P  < 0.01) but with a lower likelihood of performing systematic biopsies (OR 0.91; 95 %CI: 0.85 - 0.97; P  < 0.01). More than half (55.6 %) of patients with NDBE underwent surveillance EGD sooner (range 1 - 29 months) than the recommended interval. CONCLUSION: Adherence to quality indicators and surveillance guidelines in BE is low. Operator characteristics, including experience with endoscopic therapy for BE and time in practice predicted practice pattern. Future efforts are needed to reduce variability in practice and promote high-value care.

Carbon dioxide insufflation is associated with increased serrated polyp detection rate when compared to room air insufflation during screening colonoscopy.

BACKGROUND AND STUDY AIMS: Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) have been increasingly recognized as precursors of colorectal cancer. The aim of this study was to compare the effect of carbon dioxide insufflation (CO 2 I) vs. room air insufflation (AI) on serrated polyp detection rate (SPDR) and to identify factors associated with SPDR. PATIENTS AND METHODS: Single-center retrospective cohort study of 2083 screening colonoscopies performed with AI (November 2011 through January 2013) or CO 2 I (February 2013 to June 2015). Data on demographics, procedure characteristics and histology results were obtained from a prospectively maintained endoscopy database and chart review. SPDR was defined as proportion of colonoscopies in which ≥ 1 SSA, TSA or hyperplastic polyp (HP) ≥ 10 mm in the right colon was detected. Multi-variate analysis (MVA) was performed to identify predictors of SPDR. RESULTS: A total of 131 histologically confirmed serrated polyps (129 SSA, 2 TSA and 0 HP ≥ 10 mm) were detected. SPDR was higher with CO 2 I vs. AI (4.8 % vs. 1.4 %; P  < 0.0001). On MVA, CO 2 I was associated with higher SPDR when compared to AI (OR: 9.52; 95 % CI: 3.05 - 30.3). Both higher body mass index (OR 1.05; 95 % CI:1.02 - 1.09) and longer colonoscope withdrawal time (OR 1.11; 95 % CI: 1.07 - 1.16) were also associated with higher SPDR. CONCLUSION: CO 2 I is associated with higher SPDR when compared to AI during screening colonoscopy. While the mechanism remains unknown, we speculate that the favorable gas characteristics of CO 2 compared to room air results in improved polyp detection by optimizing bowel insufflation. These findings suggest an additional reason to prefer the use of CO 2 I over AI during colonoscopy.

Hyperinsulinism Hyperammonemia Syndrome, a Rare Clinical Constellation.

We present the unique case of adult hyperinsulinism hyperammonemia syndrome (HI/HA). This condition is rarely seen in children and even more infrequently in adults. A 27-year-old female with HI/HA, generalized tonic-clonic seizures, staring spells, and gastroesophageal reflux disease presented with diffuse abdominal pain, hypoglycemia, confusion, and sweating. She reported a history of significant nausea, vomiting, and diarrhea, which had been present intermittently over the past year. On examination, she was found to have a soft, nontender, and mildly distended abdomen without splenomegaly or masses. She had a normal blood pressure and was tachycardic (130 bpm). Her initial complete blood count and basic metabolic panel, excluding glucose, were within normal limits. She was found to have an elevated peripherally drawn venous ammonia (171 mmol/L) and near hypoglycemia (blood glucose 61 mg/dL), which were drawn given her history of HI/HA. She was continued on home carglumic acid and diazoxide, glucose was supplemented intravenously, and she was started on levetiracetam for seizure prophylaxis. An upper endoscopy (esophagogastroduodenoscopy [EGD]) was performed and was unremarkable, and biopsies taken were within normal limits. Following the EGD, she underwent a gastric emptying study that showed delayed emptying (216 minutes), consistent with a new diagnosis of gastroparesis, the likely etiology of her initial abdominal pain on presentation. This was subsequently treated with azithromycin oral solution. We present this case to raise awareness of this rarely encountered syndrome and to provide the basic principles of treatment.

Does carbon dioxide insufflation impact adenoma detection rate? A single-center retrospective analysis.

Background and study aims: Carbon dioxide (CO2) has been associated with reduced post-procedural pain and improved patient satisfaction when compared to air insufflation (AI). The effect of CO2 insufflation (CO2I) on the adenoma detection rate (ADR) remains unclear. The aims of this study are to compare ADR in patients undergoing screening colonoscopy with AI vs. CO2I and identify predictors of ADR. Patients and methods: Single-center retrospective cohort study of 2,107 patients undergoing screening colonoscopy at the University of Florida Hospital between November 2011 and June 2015. Patient demographics, procedural parameters, and histology results were retrospectively obtained from a prospectively maintained colonoscopy database. Univariate and multivariate analysis were performed to identify predictors of ADR. Results: A total of 2107 colonoscopies (644 with AI and 1463 with CO2I) were analyzed. Overall ADR was 27.8 %. There was no significant difference in ADR between AI (27.6 %) vs. CO2I (27.8 %) (P = 0.93). Method of insufflation (AI vs. CO2I) was not significantly associated with ADR (OR 0.9; 95 % CI:0.7 - 1.2). Older age (OR: 1.02; 95 % CI: 1.001 - 1.03 per year increase), male gender (OR 1.48; 95 % CI: 1.17 - 1.87), and longer scope withdraw time (OR 1.13; 95 % CI: 1.1 - 1.16 per minute) were associated with a higher ADR. Fellow involvement was negatively associated with ADR (OR 0.60; 95 % CI: 0.47 - 0.77). Conclusion: ADR was similar between patients who underwent screening colonoscopy with AI vs. CO2I. While CO2I has been associated with improved patient comfort and post-procedural recovery time, there is no definitive evidence to suggest that this method of luminal distention enhances ADR.

Evaluation of interventional endoscopy unit efficiency metrics at a tertiary academic medical center.

BACKGROUND AND STUDY AIMS: There is an increasing demand for interventional endoscopic services and the need to develop efficient endoscopic units. The aim of this study was to analyze performance data and define metrics to improve efficiency in a single academic interventional endoscopy center. ] PATIENTS AND METHODS: The prospective operations performance data (6-month period) of our interventional endoscopy unit (EU) was analyzed. First-case start time (FIRST) delay was defined as any time the first patient of the day entered the endoscopy room after the scheduled time. Non-endoscopy time (NET) and total time (TT) were defined as non-procedural and total time elapsed in the EU, respectively. Time-interval between successive patients (TISP) was defined as the time from one patient departure from the room until the time of arrival of the next patient in the room. RESULTS: A total of 1421 patients underwent 1635 endoscopic procedures. FIRST was delayed (54.2 % cases) by 13.6 min (range 1 - 53), but started within 15 min of the scheduled time in 85 % of the cases. NET accounted for 9.1 hours (67.2 %) of 13.5 hours TT/day. TISP (37.1 min, range 5 - 125) comprised 54.2 % of the NET, and was delayed (> 30 min) in 49.8 % of cases. "Patient flow" processes (registration, admission, transportation, scheduling) accounted for 50.1 % of TISP delays. CONCLUSIONS: Delays in NET, specifically TISP, rather than FIRST, were identified as a cause for decreased efficiency. "Patient flow" processes were the main reasons for delays in TISP. This study identifies potential process measures that can be used as benchmarks to improve efficiency in the EU.

Size-exclusion chromatography in multidimensional separation schemes for proteome analysis.

Size-exclusion chromatography (SEC) is a separation technique with a relatively low resolving power, compared to those usually utilized in proteomics. Therefore, it is often overlooked in experimental protocols, when the main goal is resolving complex biological mixtures. In this report, we introduce innovative multidimensional schemes for proteomics analysis, in which SEC plays a practical role. Liquid isoelectric focusing (IEF) was combined with SEC, and experimental results were compared to those obtained by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), well-established techniques relying upon similar criteria for separation. Additional experiments were performed to evaluate the practical contribution of SEC in multidimensional chromatographic separations. Specifically, we evaluated the combination of SEC and ion exchange chromatography in an analytical scheme for the mass spectrometric analysis of protein-extracts obtained from bacterial cultures grown in stable isotope enriched media. Experimental conditions and practical considerations are discussed.