SNFGE SNFGE
 
Thématique :
- Endoscopie/Imagerie
Originalité :
Intermédiaire
Solidité :
Intermédiaire
Doit faire évoluer notre pratique :
Pas encore
 
 
Nom du veilleur :
Professeur Emmanuel CORON
Coup de coeur :
 
 
Gut
  2016/06  
 
  2016 Jun;65(6):963-70  
  doi: 10.1136/gutjnl-2014-308411  
 
  Development and validation of the WASP classification system for optical diagnosis of adenomas, hyperplastic polyps and sessile serrated adenomas/polyps.  
 
  IJspeert JE, Bastiaansen BA, van Leerdam ME, Meijer GA, van Eeden S, Sanduleanu S, Schoon EJ, Bisseling TM, Spaander MC, van Lelyveld N, Bargeman M,Wang J, Dekker E; Dutch Workgroup serrAted polypS & Polyposis (WASP).  
  http://www.ncbi.nlm.nih.gov/pubmed/?term=IJspeert+JE%2C+Bastiaansen+BA%2C+van+Leerdam+ME%2C+Meijer+GA%2C+van+Eeden+S%2C+Sanduleanu+S%2C+Schoon+EJ%2C+Bisseling+TM%2C+Spaander+MC%2C+van+Lelyveld+N%2C+Bargeman+M%2CWang+J%2C+Dekker+E%3B+Dutch+Workgroup+serrAt  
 
 

OBJECTIVE:

Accurate endoscopic differentiation would enable to resect and discard small and diminutive colonic lesions, thereby increasing cost-efficiency. Current classification systems based on narrow band imaging (NBI), however, do not include neoplastic sessile serrated adenomas/polyps (SSA/Ps). We aimed to develop and validate a new classification system for endoscopic differentiation of adenomas, hyperplastic polyps and SSA/Ps <10 mm.

DESIGN:

We developed the Workgroup serrAted polypS and Polyposis (WASP) classification, combining the NBI International Colorectal Endoscopic classification and criteria for differentiation of SSA/Ps in a stepwise approach. Ten consultant gastroenterologists predicted polyp histology, including levels of confidence, based on the endoscopic aspect of 45 polyps, before and after participation in training in the WASP classification. After 6 months, the same endoscopists predicted polyp histology of a new set of 50 polyps, with a ratio of lesions comparable to daily practice.

RESULTS:

The accuracy of optical diagnosis was 0.63 (95% CI 0.54 to 0.71) at baseline, which improved to 0.79 (95% CI 0.72 to 0.86, p<0.001) after training. For polyps diagnosed with high confidence the accuracy was 0.73 (95% CI 0.64 to 0.82), which improved to 0.87 (95% CI 0.80 to 0.95, p<0.01). The accuracy of optical diagnosis after 6 months was 0.76 (95% CI 0.72 to 0.80), increasing to 0.84 (95% CI 0.81 to 0.88) considering high confidence diagnosis. The combined negative predictive value with high confidence of diminutive neoplastic lesions (adenomas and SSA/Ps together) was 0.91 (95% CI 0.83 to 0.96).

CONCLUSIONS:

We developed and validated the first integrative classification method for endoscopic differentiation of small and diminutive adenomas, hyperplastic polyps and SSA/Ps. In a still image evaluation setting, introduction of the WASP classification significantly improved the accuracy of optical diagnosis overall as well as SSA/P in particular, which proved to be sustainable after 6 months.

 

 
Question posée
 
Le Narrow Band Imaging permet-il d’identifier les lésions festonnées ?
 
Question posée
 
Cette étude multicentrique néerlandaise réalisée à partir d’image fixes a évalué la pertinence d’une nouvelle classification (WASP) qui semble capable de différencier les polypes coliques hyperplasiques, adénomateux et les lésions festonnées.
 
Commentaires

L’une des forces de cette étude est de proposer d’associer un ‘degré de confiance’ au diagnostic présumé, ce qui permet d’obtenir une excellente valeur prédictive négative (91%) et une bonne reproductibilité lorsque cet indice de confiance est fort. Il reste à évaluer cette nouvelle classification dans ‘la vraie vie’ et non sur des photos sélectionnées…

 
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