Factors associated with adenoma detection rate and diagnosis of polyps and colorectal cancer during colonoscopy in France: results of a prospective, nationwide survey

Introduction

Colonoscopy can prevent deaths due to colorectal cancer (CRC) through early diagnosis or resection of colonic adenomas. We conducted a prospective, nationwide study on colonoscopy practice in France.

Methods

An online questionnaire was administered to 2,600 French gastroenterologists. Data from all consecutive colonoscopies performed during one week were collected. A statistical extrapolation of the results to a whole year was performed, and factors potentially associated with the adenoma detection rate (ADR) or the diagnosis of polyps or cancer were assessed.

Results

A total of 342 gastroenterologists, representative of the overall population of French gastroenterologists, provided data on 3,266 colonoscopies, corresponding to 1,200,529 (95% CI: 1,125,936-1,275,122) procedures for the year 2011. The indication for colonoscopy was CRC screening and digestive symptoms in 49.6% and 38.9% of cases, respectively. Polypectomy was performed in 35.5% of cases. The ADR and prevalence of CRC were 17.7% and 2.9%, respectively. The main factors associated with a high ADR were male gender (p=0.0001), age over 50 (p=0.0001), personal or family history of CRC or colorectal polyps (p<0.0001 and p<0.0001, respectively), and positive fecal occult blood test (p=0.0005). The prevalence of CRC was three times higher in patients with their first colonoscopy (4.2% vs. 1.4%; p<0.0001).

Conclusions

For the first time in France, we report nationwide prospective data on colonoscopy practice, including histological results. We found an average ADR of 17.7%, and observed reduced CRC incidence in patients with previous colonoscopy.

Diagnosis and treatment of pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: An overview

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomic dominant disorder, which is characterized by the development of multiple arteriovenous malformations in either the skin, mucous membranes, and/or visceral organs. Pulmonary arteriovenous malformations (PAVMs) may either rupture, and lead to life-threatening hemoptysis/hemothorax or be responsible for a right-to-left shunting leading to paradoxical embolism, causing stroke or cerebral abscess. PAVMs patients should systematically be screened as the spontaneous complication rate is high, by reaching almost 50%. Neurological complications rate is considerably higher in patients presenting with diffuse pulmonary involvement. PAVM diagnosis is mainly based upon transthoracic contrast echocardiography and CT scanner examination. The latter also allows the planification of treatments to adopt, which consists of percutaneous embolization, having replaced surgery in most of the cases. The anchor technique consists of percutaneous coil embolization of the afferent pulmonary arteries of the PAVM, by firstly placing a coil into a small afferent arterial branch closely upstream the PAVM. Enhanced contrast CT scanner is the key follow-up examination that depicts the PAVM enlargement, indicating the various mechanisms of PAVM reperfusion. When performed by experienced operators as the prime treatment, percutaneous embolization of PAVMs, is a safe, efficient and sustained therapy in the great majority of HHT patients.

Periodic magnetorotational dynamo action as a prototype of nonlinear magnetic-field generation in shear flows

The nature of dynamo action in shear flows prone to magnetohydrodynamc instabilities is investigated using the magnetorotational dynamo in Keplerian shear flow as a prototype problem. Using direct numerical simulations and Newton's method, we compute an exact time-periodic magnetorotational dynamo solution to three-dimensional dissipative incompressible magnetohydrodynamic equations with rotation and shear. We discuss the physical mechanism behind the cycle and show that it results from a combination of linear and nonlinear interactions between a large-scale axisymmetric toroidal magnetic field and nonaxisymmetric perturbations amplified by the magnetorotational instability. We demonstrate that this large-scale dynamo mechanism is overall intrinsically nonlinear and not reducible to the standard mean-field dynamo formalism. Our results therefore provide clear evidence for a generic nonlinear generation mechanism of time-dependent coherent large-scale magnetic fields in shear flows and call for new theoretical dynamo models. These findings may offer important clues to understanding the transitional and statistical properties of subcritical magnetorotational turbulence.

Endoscopy and antiplatelet agents. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

With the increasing use of antiplatelet agents (APA), their management during the periendoscopic period has become a more common and more difficult problem. The increase in use is due to the availability of new drugs and the widespread use of drug-eluting coronary stents. Acute coronary syndromes can occur when APA therapy is withheld for noncardiovascular interventions. Guidelines about APA management during the periendoscopic period are traditionally based on assessments of the procedure-related risk of bleeding and the risk of thrombosis if APA are stopped. New data allow better assessment of these risks, of the necessary duration of APA discontinuation before endoscopy, of the use of alternative procedures (mostly for endoscopic retrograde cholangiopancreatography [ERCP]), and of endoscopic methods that can be used to prevent bleeding (following colonic polypectomy). This guideline makes graded, evidence-based, recommendations for the management of APA for all currently performed endoscopic procedures. A short summary and two tables are included for quick reference.

Pancreatic involvement in hereditary hemorrhagic telangiectasia: assessment with multidetector helical CT

PURPOSE

To evaluate and describe pancreatic involvement by using multidetector computed tomography (CT) in patients with a diagnosis of hereditary hemorrhagic telangiectasia (HHT).

MATERIALS AND METHODS

Institutional review board approval was obtained, and all patients provided informed consent. Across 12 months, all consecutive adult patients with a confirmed diagnosis of HHT referred to our pluridisciplinary HHT center for evaluation were enrolled prospectively in the study and underwent contrast material-enhanced multidetector CT of the abdomen. Pancreatic telangiectases and arteriovenous fistulas were noted, and their characteristics were described. Genetic mutation was also investigated.

RESULTS

Thirty-five patients (19 women, 16 men; mean age, 48.4 years) were included. All patients were asymptomatic. A genetic mutation was identified in 28 (80%) patients, including endoglin in 16 (57%), activin type-II-like receptor kinase 1 (ALK1) in 11 (39%), and SMAD4 in one (4%). Eleven (31%) patients exhibited pancreatic involvement. Fifty-four percent of patients with ALK1 mutation had pancreatic involvement. Twenty-three pancreatic telangiectases were identified during the arterial phase in nine patients. Seven pancreatic arteriovenous malformations (AVMs) were identified in four patients.

CONCLUSION

Pancreatic involvement commonly is found in patients with HHT (31% in our study), mainly in patients with ALK1 mutation; pancreatic telangiectases or AVMs are only diagnosed duringthe arterial phase at multidetector CT.