Table 2. Characteristics of the stricture studies included in a systematic review and meta-analysis of the efficacy of peroral cholangioscopy for difficult bile duct stones and indeterminate strictures.
| First author | Year | Setting | Study design | Type of POC | Sample size | Technical success rate | Patients involved (VISUAL), n | Stricture sensitivity (VISUAL) | Stricture specificity (VISUAL) | Stricture accuracy (VISUAL) | Patients involved (BIOPSY), n | Biopsy samples per patient, mean, n | Stricture sensitivity (BIOPSY) | Stricture specificity (BIOPSY) | Stricture accuracy (BIOPSY) | Complication/adverse event rate | Patients lost to follow-up, n | Duration of follow-up, mean, mo | NOS score |
| Akerman | 2012 | Single | Retrospective | Catheter-based | 34 | 0.97 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0 | NR | 0 | 3 |
| Alameel | 2013 | Single | Prospective | Catheter-based | 30 | NR | 19 | 0.83 | 0.84 | 0.84 | 16 | NR | 0.4 | 1 | 0.81 | 0.05 | 0 | 5 | 5 |
| Albert | 2011 | Single | Prospective | Ultraslim endoscope | 22 | 0.88 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.045 | NR | 0 | 3 |
| Awadallah | 2006 | Single | Prospective | Mother – daughter | 41 | NR | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.05 | 1 | 0 | 5 |
| Chen | 2011 | Multicenter | Prospective | Catheter-based | 297 | 0.983 | 95 | 0.78 | 0.82 | 0.8 | 95 | 3 | 0.49 | 0.98 | 0.75 | 0.075 | 20 | > 6 | 6 |
| Chen | 2007 | Multicenter | Prospective | Catheter-based | 35 | NR | 20 | 1 | 0.77 | 0.85 | 20 | 4.5 | 0.71 | 1 | 0.9 | 0.06 | 0 | > 6 | 6 |
| Draganov | 2011 | Single | Prospective | Catheter-based | 75 | 0.933 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.048 | 0 | 0 | 3 |
| Draganov | 2012 | Single | Prospective | Catheter-based | 26 | 1 | 0 | NR | NR | NR | 26 | NR | 0.765 | 1 | 0.846 | 0.077 | 0 | 21.78 | 6 |
| Farnik | 2014 | Multicenter | Retrospective | Ultraslim endoscope | 89 | 0.885 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.077 | NR | 0 | 3 |
| Fishman | 2009 | Single | Retrospective | Catheter-based | 128 | NR | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0 | NR | 0 | 3 |
| Fukuda | 2005 | Single | Retrospective | Mother – daughter | 97 | 1 | 76 | 1 | 0.87 | 0.934 | 0 | NR | NR | NR | NR | 0.02 | NR | > 12 | 6 |
| Hartman | 2012 | Single | Retrospective | Catheter-based | 89 | NR | 15 | 0.88 | 0.86 | 0.87 | 29 | 3 | 0.57 | 1 | 0.78 | NR | 3 | 23 | 5 |
| Itoi | 2014 | Multicenter | Prospective | Ultraslim endoscope | 41 | 0.83 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.048 | NR | 0 | 3 |
| Itoi | 2010 | Multicenter | Retrospective | Mother – daughter | 144 | NR | 0 | NR | NR | NR | 0 | 1.6 | NR | NR | NR | 0.07 | 0 | > 12 | 6 |
| Kalaitzakis | 2012 | Multicenter | Retrospective | Catheter-based | 165 | 0.95 | 0 | NR | NR | NR | 49 | 3 | 0.62 | 1 | 0.84 | 0.09 | 4 | 15 | 5 |
| Khan | 2013 | Single | Retrospective | NA | 66 | NR | 0 | NR | NR | NR | 66 | NR | 0.487 | 0.963 | 0.68 | NR | 0 | 0 | 3 |
| Liu | 2014 | Multicenter | Retrospective | Catheter-based | 25 | NR | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0 | NR | 0 | 4 |
| Manta | 2013 | Single | Prospective | Catheter-based | 52 | 1 | 0 | NR | NR | NR | 42 | NR | 0.88 | 0.94 | 0.9 | 0.038 | 0 | 24 | 6 |
| Meves | 2014 | Single | Prospective | Ultraslim endoscope | 84 | 0.87 | 0 | NR | NR | NR | 26 | NR | 0.895 | NR | NR | 0.12 | NR | 0 | 4 |
| Moon | 2009 | Single | Prospective | Ultraslim endoscope | 29 | 0.78 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0 | NR | 0 | 3 |
| Nguyen | 2013 | Single | Prospective | Catheter-based | 40 | 0.947 | 0 | NR | NR | NR | 18 | NR | NR | NR | 0.89 | 0.05 | 0 | 22 | 6 |
| Nishikawa | 2013 | Single | Prospective | Mother – daughter | 33 | 1 | 33 | 1 | 0.917 | 0.97 | 33 | 2.39 | 0.381 | 1 | 0.606 | 0.06 | 0 | > 12 | 6 |
| Osanai | 2013 | Multicenter | Prospective | Mother – daughter | 87 | 1 | 38 | 0.964 | 0.8 | 0.921 | 35 | 2.4 | 0.815 | 1 | 0.857 | 0.069 | 0 | > 12 | 6 |
| Pohl | 2013 | Single | RCT | Mixed | 60 | 0.88 | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.117 | 0 | 6 | 6 |
| Ramchandani | 2011 | Single | Prospective | Catheter-based | 36 | 1 | 36 | 0.95 | 0.79 | 0.89 | 33 | 3.5 | 0.82 | 0.82 | 0.82 | 0.083 | 0 | > 6 | 6 |
| Shah | 2006 | Single | Prospective | Mother – daughter | 62 | NR | 0 | NR | NR | NR | 0 | NR | NR | NR | NR | 0.056 | 4 | 12.4 | 6 |
| Siddiqui | 2012 | Single | Retrospective | Catheter-based | 30 | NR | 0 | NR | NR | NR | 30 | NR | 0.77 | NR | NR | 0.033 | 0 | > 6 | 6 |
| Tischendorf | 2006 | Single | Prospective | Mother – daughter | 53 | 1 | 53 | 0.92 | 0.93 | 0.93 | 0 | NR | NR | NR | NR | 0 | 0 | 37 | 6 |
| Woo | 2014 | Single | Retrospective | Catheter-based | 32 | NR | 31 | 1 | 0.9 | 0.967 | 19 | 2.84 | 0.642 | 1 | 0.736 | 0.094 | 0 | > 6 | 6 |
POC, peroral cholangioscopy; NR, not reported; NA, not applicable; NOS, Newcastle – Ottawa Scale.