Targeted transcriptomic analysis of pancreatic adenocarcinoma in EUS-FNA samples by NanoString technology.

Background: Integration of transcriptomic testing into EUS-FNA samples is a growing need for precision oncology in pancreatic ductal adenocarcinoma (PDAC). The NanoString platform is suitable for transcriptome profiling in low yield RNA samples. Methods: Inclusion of patients that underwent EUS-FNA cytological diagnosis of pancreatic ductal adenocarcinoma using 19G and/or 22G needles and subsequent surgical resection. Formalin-fixed, paraffin-embedded (FFPE) cytological and surgical samples underwent RNA extraction and transcriptomic analysis using a custom 52-gene NanoString panel of stromal PDAC features. Cell type abundance was quantified in FFPE specimens and correlated. Results: 18 PDAC patients were included. Mean EUS-FNA passes was 2 + 0.7. All FFPE passed the RNA quality control for genomic analysis. Hierarchical clustering on the global gene expression data showed that genes were differentially expressed between EUS and surgical samples. A more enriched cancer-associated fibroblasts and epithelial-mesenchymal transition transcriptomic profile was observed across surgical specimens whereas immunological biomarkers were more represented in EUS-FNA samples. Cytological examination confirmed a scanty representation of CAF and more immunological cell abundance in cytological samples in comparison to surgical specimens. Conclusion: Targeted transcriptomic NanoString profiling of PDAC samples obtained by EUS-FNA is a feasible approach for pre-surgical molecular analysis although stromal CAF/EMT mRNA biomarkers are underrepresented.

EUS-guided tissue acquisition in the study of the adrenal glands: Results of a nationwide multicenter study.

BACKGROUND: There are limited data about the role of endoscopic ultrasound-guided tissue acquisition (EUS-TA), by fine needle aspiration (EUS-FNA) or biopsy (EUS-FNB), in the evaluation of the adrenal glands (AG). The primary aim was to assess the diagnostic yield and safety. The secondary aims were the malignancy predictors, and to create a predictive model of malignancy. METHODS: This was a retrospective nationwide study involving all Spanish hospitals experienced in EUS-TA of AGs. Inclusion period was from April-2003 to April-2016. Inclusion criteria: all consecutive cases that underwent EUS-TA of AGs. EUS and cytopathology findings were evaluated. Statistical analyses: diagnostic accuracy of echoendoscopist's suspicion using cytology by EUS-TA, as gold standard; multivariate logistic regression model to predict tumor malignancy. RESULTS: A total of 204 EUS-TA of AGs were evaluated. Primary tumor locations were lung70%, others19%, and unknown11%. AG samples were adequate for cytological diagnosis in 91%, and confirmed malignancy in 60%. Diagnostic accuracy of the endosonographer's suspicion was 68%. The most common technique was: a 22-G (65%) and cytological needle (75%) with suction-syringe (66%). No serious adverse events were described. The variables most associated with malignancy were size>30mm (OR2.27; 95%CI, 1.16-4.05), heterogeneous echo-pattern (OR2.11; 95%CI, 1.1-3.9), variegated AG shape (OR2.46; 95%CI, 1-6.24), and endosonographer suspicion (OR17.46; 95%CI, 6.2-58.5). The best variables for a predictive multivariate logistic model of malignancy were age, sex, echo-pattern, and AG-shape. CONCLUSIONS: EUS-TA of the AGs is a safe, minimally invasive procedure, allowing an excellent diagnostic yield. These results suggest the possibility of developing a pre-EUS procedure predictive malignancy model.

Efficacy and safety of a combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 as a submucosal injection solution for endoscopic resection: pilot study on a swine model.

BACKGROUND AND AIMS: Endoscopic resection techniques require use of submucosal injection. The aim of this study was to assess a new solution that combines hyaluronic acid, chondroitin sulfate, and poloxamer 407 for submucosal injection. METHODS: A total of 48 gastric submucosal cushions were created in fresh porcine stomachs using gelafundin (n = 16) or the new solution diluted at 50 % (n = 16), or 80 % (n = 16). The duration of mucosal elevation was measured. In an in vivo model, 10 gastric submucosal cushions were created by injecting 2 mL of the new solution at 80 % and the animal was euthanized 30 minutes after the last injection. RESULTS: Submucosal cushions with the new solution at 80 % and 50 % concentration lasted longer than with gelafundin (23.13 ±â€Š15.57, 13.1 ±â€Š6.6, 3.94 ±â€Š1.53 minutes, respectively; P  = 0.000). In the in vivo study, no damage or necrosis was observed in the mucosa or muscularis propria. CONCLUSION: The combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 produces a long-lasting submucosal cushion and does not seem to induce acute damage in the tissue making it suitable for submucosal injection.

Ascorbic acid PEG-2L is superior for early morning colonoscopies in colorectal cancer screening programs: A prospective non-randomized controlled trial

BACKGROUND: The quality of colon cleansing and the tolerability of anterograde preparation are essential to the success of colorectal cancer screening. AIM: To compare the tolerability and efficacy of low-volume preparations vs the standard regimen in individuals scheduled for an early morning colonoscopy. Study: Participants in a population-based colorectal cancer screening program using the fecal immunochemical test who were scheduled for a colonoscopy from 09:00 a.m. to 10:20 a.m. were prospectively included and assigned to: (1) control group (PEG-ELS 4L): PEG 4L and electrolytes; (2) group AscPEG-2L: a combination of PEG and ascorbic acid 2L; and (3) group PiMg: sodium picosulfate and magnesium citrate 500 mL plus 2 L of clear fluids. Tolerability was evaluated with a questionnaire and the quality of bowel preparation with the Boston Bowel Preparation Scale. RESULTS: A total of 292 participants were included: 98 in the PEG-ELS 4L control group, 96 in the AscPEG-2L study group and 98 in the PiMg study group. Low-volume treatments were better tolerated than the standard solution (AscPEG-2L 94.8% and PiMg 93.9% vs PEG-ELS 4L 75.5%; p < 0.0001). The effectiveness of AscPEG-2L was superior to that of PEG-ELS 4L and PiMg (p = 0.011 and p = 0.032, respectively). Patient acceptance was higher for single-dose than for split-dose administration but efficacy was higher with the split dose than with other doses. CONCLUSIONS: In early morning colonoscopies, ascPEG-2L appears to be the best option, especially when administered in a split-dose

ANTECEDENTES: La calidad de la limpieza del colon y la tolerancia a la preparación anterógrada son claves para el éxito de un programa de cribado de cáncer colorrectal. OBJETIVO: Comparar la tolerancia y eficacia de las preparaciones de volumen reducido frente a la preparación estándar en pacientes programados para colonoscopia a primera hora de la mañana. Estudio: Individuos del programa de cribado poblacional con test de sangre oculta en heces programados para colonoscopia entre las 09:00 y 10:20 a.m fueron prospectivamente asignados a: 1) Grupo Control (PEG-ELS 4L): PEG con electrolitos 4 litros; 2) Grupo AscPEG-2L: PEG más ácido ascórbico 2 litros; y 3) Groupo PiMg: picosulfato sódico más citrato de magnesio 500 ml seguido de 2 litros de líquidos claros. Se evaluó la tolerancia mediante cuestionario y la calidad mediante la Boston Bowel Preparation Scale. RESULTADOS: Se incluyeron 292 sujetos: 98 en el grupo control PEG-ELS 4L, 96 en el grupo a estudio AscPEG-2L y 98 en el grupo a estudio PiMg. Las soluciones de volumen reducido fueron mejor toleradas que la solución estándar (AscPEG-2L 94.8% y PiMg 93.9% vs PEG-ELS 4L 75.5%; p < 0.0001). La calidad de la preparación fue superior en el grupo AscPEG-2L que en el grupo control PEG-ELS 4L y grupo PiMg (p = 0.011 and p = 0.032, respectivamente). Las dosis partidas fueron peor aceptadas por los sujetos pero resultaron en una mayor calidad de la preparación. CONCLUSIONES: AscPEG-2L es la mejor opción para las colonoscopias programadas a primera hora de la mañana, especialmente cuando se administra en dosis partida

Ascorbic acid PEG-2L is superior for early morning colonoscopies in colorectal cancer screening programs: a prospective non-randomized controlled trial.

BACKGROUND: The quality of colon cleansing and the tolerability of anterograde preparation are essential to the success of colorectal cancer screening. AIM: To compare the tolerability and efficacy of low-volume preparations vs the standard regimen in individuals scheduled for an early morning colonoscopy. STUDY: Participants in a population-based colorectal cancer screening program using the fecal immunochemical test who were scheduled for a colonoscopy from 09:00 a.m. to 10:20 a.m. were prospectively included and assigned to: (1) control group (PEG-ELS 4L): PEG 4L and electrolytes; (2) group AscPEG-2L: a combination of PEG and ascorbic acid 2L; and (3) group PiMg: sodium picosulfate and magnesium citrate 500 mL plus 2L of clear fluids. Tolerability was evaluated with a questionnaire and the quality of bowel preparation with the Boston Bowel Preparation Scale. RESULTS: A total of 292 participants were included: 98 in the PEG-ELS 4L control group, 96 in the AscPEG-2L study group and 98 in the PiMg study group. Low-volume treatments were better tolerated than the standard solution (AscPEG-2L 94.8% and PiMg 93.9% vs PEG-ELS 4L 75.5%; p < 0.0001). The effectiveness of AscPEG-2L was superior to that of PEG-ELS 4L and PiMg (p = 0.011 and p = 0.032, respectively). Patient acceptance was higher for single-dose than for split-dose administration but efficacy was higher with the split dose than with other doses. CONCLUSIONS: In early morning colonoscopies, ascPEG-2L appears to be the best option, especially when administered in a split-dose.

The problem of an incidental uniloculated cyst.

Incidental uniloculated cysts are diagnosed more frequently due to the increase in availability of high-quality abdominal imaging. The prevalence of incidental pancreatic cysts detected on abdominal imaging is 2.6% and is even higher in old patients. Pancreatic cysts are also found in up to 25% of autopsies, 3% of which present progression to carcinoma in situ. The most frequently incidental cysts detected are <10 mm in size and the spectrum has changed from inflammatory to mucinous lesions. Although some morphological and cytological features can help to establish the nature of these cysts, it is unclear how many of them carry a risk of malignant degeneration, how to identify those accurately, and, once recognized, how to establish which ones are likely to harbor incipient cancer and how to manage them. In the last years, some guidelines have been elaborated that summarize all the evidence published up to now and provide clinicians with useful recommendations regarding the management of pancreatic uniloculated cysts.

Euro-NOTES Status Paper: from the concept to clinical practice.

BACKGROUND: The concept of natural orifice transluminal endoscopic surgery (NOTES) consists of the reduction of access trauma by using a natural orifice access to the intra-abdominal cavity. This could possibly lead to less postoperative pain, quicker recovery from surgery, fewer postoperative complications, fewer wound infections, and fewer long-term problems such as hernias. The Euro-NOTES Foundation has organized yearly meetings to work on this concept to bring it safely into clinical practice. The aim of this Euro-NOTES status update is to assess the yearly scientific working group reports and provide an overview on the current clinical practice of NOTES procedures. METHODS: After the Euro-NOTES meeting 2011 in Frankfurt, Germany, an analysis was started regarding the most important topics of the European working groups. All prospectively documented information was gathered from Euro-NOTES and D-NOTES working groups from 2007 to 2011. The top five topics were analyzed. RESULTS: The statements of the working group activities demonstrate the growing information and changing insights. The most important selected topics were infection issue, peritoneal access, education and training, platforms and new technology, closure, suture, and anastomosis. The focus on research topics changed over time. The principle of hybrid access has overcome the technical and safety limitations of pure NOTES. Currently the following NOTES access routes are established for several indications: transvaginal access for cholecystectomy, appendectomy and colon resections; transesophageal access for myotomy; transgastric access for full-thickness small-tumor resections; and transanal/transcolonic access for rectal and colon resections. CONCLUSIONS: NOTES and hybrid NOTES techniques have emerged for all natural orifices and were introduced into clinical practice with a good safety record. There are different indications for different natural orifices. Each technique has been optimized for the purpose of finding a safe and realistic solution to perform the procedure according to the specific indication.

NOTES in Europe: summary of the working group reports of the 2012 EURO-NOTES meeting.

The sixth EURO-NOTES workshop (4 - 6 October 2012, Prague, Czech Republic) focused on enabling intensive scientific dialogue and interaction between surgeons, gastroenterologists, and engineers/industry representatives and discussion of the state of the practice and development of natural orifice transluminal endoscopic surgery (NOTES) in Europe. In accordance with previous meetings, five working groups were formed. In 2012, emphasis was put on specific indications for NOTES and interventional endoscopy. Each group was assigned an important indication related to ongoing research in NOTES and interventional endoscopy: cholecystectomy and appendectomy, therapy of colorectal diseases, therapy of adenocarcinoma and neoplasia in the upper gastrointestinal tract, treating obesity, and new therapeutic approaches for achalasia. This review summarizes consensus statements of the working groups.

Indications, results, and clinical impact of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

This article is part of a combined publication that expresses the current view of the European Society of Gastrointestinal Endoscopy (ESGE) about endoscopic ultrasound (EUS)-guided sampling in gastroenterology, including EUS-guided fine needle aspiration (EUS-FNA) and EUS-guided trucut biopsy (EUS-TCB), of submucosal tumors, diffuse esophageal/gastric wall thickening, pancreatic solid masses and cystic-appearing lesions, mediastinal lesions unrelated to lung or esophageal cancer, cancer of the esophagus, stomach, and rectum, lymph nodes of unknown origin, adrenal gland masses, and focal liver lesions. False-positive cytopathological results and needle tract seeding are also discussed. The present Clinical Guideline describes the results of EUS-guided sampling in the different clinical settings, considers the role of this technique in patient management, and makes recommendations on circumstances that warrant its use. A two-page executive summary of evidence statements and recommendations is provided. A separate Technical Guideline describes the general technique of EUS-guided sampling, particular techniques to maximize the diagnostic yield depending on the nature of the target lesion, and sample processing. The target readership for the Clinical Guideline mostly includes gastroenterologists, oncologists, internists, and surgeons while the Technical Guideline should be most useful to endoscopists who perform EUS-guided sampling.

The role of a computed tomography-based image registered navigation system for natural orifice transluminal endoscopic surgery: a comparative study in a porcine model.

BACKGROUND AND STUDY AIMS: Most natural orifice transluminal endoscopic surgery (NOTES) procedures have been performed in animal models through the anterior stomach wall, but this approach does not provide efficient access to all anatomic areas of interest. Moreover, injury of the adjacent structures has been reported when using a blind access. The aim of the current study was to assess the utility of a CT-based (CT: computed tomography) image registered navigation system in identifying safe gastrointestinal access sites for NOTES and identifying intraperitoneal structures. METHODS: A total of 30 access procedures were performed in 30 pigs: anterior gastric wall (n = 10), posterior gastric wall (n = 10), and anterior rectal wall (n = 10). Of these, 15 procedures used image registered guidance (IR-NOTES) and 15 procedures used a blind access (NOTES only). Timed abdominal exploration was performed with identification of 11 organs. The location of the endoscopic tip was tracked using an electromagnetic tracking system and was recorded for each case. Necropsy was performed immediately after the procedure. The primary outcome was the rate of complications; secondary outcome variables were number of organs identified and kinematic measurements. RESULTS: A total of 30 animals weighting a mean (± SD) of 30.2 ± 6.8 kg were included in the study. The incision point was correctly placed in 11 out of 15 animals in each group (73.3 %). The mean peritoneoscopy time and the number of properly identified organs were equivalent in the two groups. There were eight minor complications (26.7 %), two (13.3 %) in the IR-NOTES group and six (40.0 %) in the NOTES only group ( P = n. s.). Characteristics of the endoscope tip path showed a statistically significant improvement in trajectory smoothness of motion for all organs in the IR-NOTES group. CONCLUSION: The image registered system appears to be feasible in NOTES procedures and results from this study suggest that image registered guidance might be useful for supporting navigation with an increased smoothness of motion.

Endoscopic ultrasound-guided fine-needle aspiration and trucut biopsy in the diagnosis of gastric stromal tumors: a randomized crossover study.

BACKGROUND AND AIM: The diagnosis of gastrointestinal stromal tumors (GISTs) has important prognostic and therapeutic implications. The specific diagnosis of GIST has to be based on immunocytochemistry. This study aimed to prospectively compare in a crossover manner the accuracy of endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) and EUS-guided trucut biopsy (EUS-TCB) in the specific diagnosis of gastric GISTs. We hypothesized that EUS-TCB is superior to EUS-FNA in this respect. PATIENTS AND METHODS: Forty patients with gastric subepithelial tumors suspected on the basis of EUS of being a GIST underwent both EUS-FNA and EUS-TCB. The sequence in which the techniques were employed was randomly assigned to avoid bias. RESULTS: Forty tumors were sampled (mean number of passes: 2.1 +/- 0.9 with EUS-TNB and 1.9 +/- 0.8 with EUS-FNA; P = not significant, NS). Final diagnoses were: GIST (n = 27), carcinoma (n = 2), leiomyoma (n = 1), schwannoma (n = 1), and no diagnosis possible (n = 9). Device failure occurred in 6 patients with EUS-TCB. A cytohistological diagnosis of mesenchymal tumor (n = 29) and carcinoma (n = 2) was made in 70 % of cases by EUS-FNA and in 60 % of cases by EUS-TCB ( P = NS). Among the samples that were adequate, immunohistochemistry could be performed in 74 % of EUS-FNA samples and in 91 % of EUS-TCB samples ( P = 0.025). When inadequate samples were included, the overall diagnostic accuracy of EUS-FNA was 52 % and that of EUS-TCB was 55 % ( P = NS). There were no complications. CONCLUSIONS: EUS-TCB is not superior to EUS-FNA in GISTs because of the high rate of technical failure of trucut. However, when an adequate sample is obtained with EUS-TCB, immunohistochemical phenotyping is almost always possible. EUS-TCB can be safely performed in this set of patients.

Incidence and clinical significance of hyperamylasemia after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions: a prospective and controlled study.

BACKGROUND AND STUDY AIM: Acute pancreatitis as a complication of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions is rarely observed. However, there is little information on the incidence of hyperamylasemia after EUS-FNA of the pancreas and its clinical significance. This study aimed to supply this lack of information. PATIENTS AND METHODS: Patients who underwent EUS-FNA of a pancreatic lesion between October 2004 and October 2005 were studied prospectively. Exclusion criteria were: (i) platelet count under 50,000/mm (3) and/or prothrombin time < 50 %; (ii) performance of surgery, endoscopic retrograde cholangiopancreatography (ERCP), a percutaneous biopsy attempt, or another invasive procedure within 7 days before EUS-FNA; (iii) lack of informed consent. Serum amylase levels were determined before and 8 and 24 h after the procedure. Hyperamylasemia was defined by amylase levels above 104 UI/L (and higher than baseline levels) 8 h after the procedure. Acute pancreatitis was defined by upper abdominal pain (with or without nausea and/or vomiting) accompanied by elevation of serum amylase or lipase to at least twice baseline levels. RESULTS: A total of 100 patients underwent EUS-FNA of a pancreatic lesion (58 men, 42 women; mean age 60 +/- 13 years). Eleven patients (11 %) showed hyperamylasemia 8 h after the puncture (298 +/- 293 UI/L, range 105 - 1044 UI/L), but only two of them developed acute mild pancreatitis after EUS-FNA. Hyperamylasemia was not related either to the type of lesion (cystic or solid) or to its location, the duration of the procedure, or the number of passes performed. CONCLUSIONS: Pancreatitis after pancreatic EUS-FNA occurs in 2 % of patients, with some more cases of silent hyperamylasemia. This complication may have to be included in the information given to patients for their informed consent.

EUS FNA in intraductal papillary mucinous tumors of the pancreas.

BACKGROUND/AIMS: There is little information concerning the potential role of fine-needle aspiration guided by endoscopic ultrasonography in the pathologic diagnosis of intraductal papillary mucinous tumors of the pancreas. METHODOLOGY: Patients with an intraductal papillary mucinous tumor of the pancreas suggested by endoscopic ultrasonography underwent fine-needle aspiration guided by endoscopic ultrasonography in order to investigate the presence of mucin and/or cytologic changes consistent with this diagnosis. A group of 111 patients with other pancreatic lesions explored during the same period of time was used as a control group. RESULTS: Fine-needle aspiration guided by endoscopic ultrasonography was safely performed in 19 patients and supported the diagnosis in 17 of them. Nine out of the 17 patients with suspicion of intraductal papillary mucinous tumors of the pancreas went to surgery and this diagnosis was confirmed in the resected specimen in all of them. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS FNA in the diagnosis of IPMT were 82%, 100%, 100%, 92% and 94% respectively. CONCLUSIONS: Fine-needle aspiration guided by endoscopic ultrasonography is a good technique to support the diagnosis of intraductal papillary mucinous tumors of the pancreas and should be considered in this group of patients if pathologic confirmation is judged to be necessary.

Prospective assessment of the role of antibiotic prophylaxis in ERCP.

BACKGROUND/AIMS: Despite the existence of published recommendations, various studies of antibiotic prophylaxis have reached conflicting conclusions, and controversy exists regarding the role of antibiotic prophylaxis in ERCP. The aim of this study was to analyze the efficacy of the intramuscular administration of clindamicine and gentamicine before ERCP. METHODOLOGY: Sixty-one consecutive patients referred for ERCP were prospectively randomized to receive either clindamicine 600mg and gentamicine 80mg, both intramuscularly one hour before the ERCP (group I; 31 patients) or not (group II; 30 patients). Two blood samples were obtained from every patient (just before endoscopy and within 5 minutes of withdrawal of the endoscope) and were incubated for 7 days and examined daily for growth of bacteria. Patients were closely monitored for 7 days after endoscopy to detect the development of infectious complications. RESULTS: Only 7 cultures from 7 patients were positive. Four were obtained post-ERCP (two patients in group I and two in group II) and the remaining three before endoscopy. The post-ERCP isolated bacteria were: Streptococcus mitis, Peptoestreptococcus anaerobious, Moraxella spp and Escherichia coli. Two patients, one from each group, developed post-ERCP cholangitis that were solved with medical treatment. CONCLUSIONS: Our findings indicate that ERCP induce bacteremia in a small group of patients and suggest that prophylactic administration of clindamicine plus gentamicine does not reduce the incidence of bacteremia and cholangitis, and do not support the routine use of prophylactic antibiotics prior to ERCP.

Endoscopia digestiva en la ingesta de cáusticos / Digestive tract endoscopy in caustic ingestion

La ingesta de productos cáusticos, ácidos o bases, puede producir lesiones digestivas altas, que pueden ir desde el edema y la hiperemia hasta úlceras profundas y extensas áreas de necrosis, con riesgo vital para el paciente. La endoscopia digestiva permite confirmar o descartar la presencia de estas lesiones, clasificarlas en caso de que estén presentes, establecer un pronóstico y contribuir a definir las medidas terapéuticas a aplicar, y sólo está contraindicada cuando se sospecha que hay una perforación digestiva o que ésta podría producirse al practicar esta exploración

The ingestion of caustics, both acids and alkalis, can cause upper gastrointestinal tract lesions ranging from oedema and hyperaemia to life-threatening deep ulcerations and extensive areas of necrosis. Digestive tract endoscopy may confirm or rule out the presence of such lesions, classify them when present, establish a prognosis and contribute to defining the therapeutic intervention. Endoscopy is only contraindicated when viscus perforation is suspected, or when a viscus perforation may occur when carrying out procedure

The European panel on the appropriateness of gastrointestinal endoscopy guidelines colonoscopy in an open-access endoscopy unit: a prospective study.

BACKGROUND: The demand for gastrointestinal endoscopy is increasing in most developed countries, resulting in an important rise in overall costs and waiting lists for endoscopic procedures. Therefore, adherence to appropriate indications for these procedures is essential for the rational use of finite resources in an open-access system. AIM: To assess indications and appropriateness of colonoscopy according to the European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) criteria. METHODS: From May to June 2004, all consecutive patients referred to our Unit for open-access colonoscopy were considered for inclusion in this prospective study. Appropriateness of each colonoscopy was established according to the EPAGE criteria. In order to evaluate whether appropriateness of use correlated with the diagnostic yield of colonoscopy, relevant endoscopic findings were also recorded. RESULTS: A total of 350 consecutive patients were included in the study. In 38 of them, the colonoscopy indication was not listed in the EPAGE guidelines and, consequently, they were not evaluated. In the remaining 312 patients, the indication for the procedure was considered inappropriate in 73 (23%) patients. Both referring doctor characteristics (specialty and health care setting) and patient data (age) correlated with appropriateness of endoscopy. The diagnostic yield was significantly higher for appropriate colonoscopies (42%) than in those judged inappropriate (21%) (P = 0.001). CONCLUSIONS: A noteworthy proportion of patients referred for colonoscopy to an open-access endoscopy unit are considered inappropriate because of their indication, with significant differences among specialties. These results suggest that implementation of validated guidelines for its appropriate use could improve this situation and, considering the correlation between appropriateness and diagnostic yield, even contribute to improve the prognosis of patients with colorectal diseases.