Starting resection of a polyp beyond the competency of the endoscopist
It is established that there are specific features of colorectal polyps which determine how difficult they will be to resect endoscopically. The SMSA score31 (table 1) describes four characteristics (polyp size, morphology, site, and access). It generates four categories of colorectal polyp complexity and has been shown to predict important outcomes after polypectomy, including incomplete resection and the frequency of adverse events (including delayed bleeding and perforation).32
Furthermore, among the most difficult to resect polyps (SMSA group 4), there is a subset which requires specific expertise. For this reason, a modification to the SMSA score has been suggested, which allows for the identification of such polyps. Known as the SMSA+ score (table 1), it combines two published scores33,34 and includes size ≥ 40mm, non-lifting polyps, non-granular polyps ≥ 20mm, location at flexures, the anorectal junction, the ileocaecal valve, and the appendiceal orifice or diverticulum involvement.
Endoscopic practitioners should not attempt resection of a colorectal polyp beyond their competency. Resection of SMSA group 3 polyps or above should be attempted by those performing polypectomy routinely and can deal with adverse events. SMSA+ polyps should be attempted only by practitioners who regularly perform referral practice for endoscopic mucosal resection (EMR).35
This is highlighted by the possible consequences that patients must face after a failed attempt at polypectomy:
- Need for multiple procedures where one may have sufficed in expert hands (repeat bowel preparation, lost workdays for patients, inconvenience).36 In our experience, there are often multiple attempts by the initial endoscopist prior to referral
- Morbidity, unnecessary hospital admission or even need for surgery due to an adverse event that cannot be managed by the endoscopist
- Need for unnecessary surgery due to scar formation and non-lifting at a second attempt or adverse events related to a second attempt37
<1cm |
1 |
Pedunculated |
1 |
Left Colon |
1 |
Easy |
1 |
1 |
4-5 points |
1-1.9 cm |
1 |
Sessile |
2 |
Right Colon |
2 |
Difficult |
3 |
2 |
6-9 points |
2-2.9 cm |
5 |
Flat |
3 |
|
|
|
|
3 |
9-12 points |
3-3.9 cm |
7 |
|
|
|
|
|
|
4 |
>12 points |
>4cm |
9 |
|
|
|
|
|
|
|
|
<4cm |
0 |
No |
0 |
Lifting/
no previous attempt |
0 |
Granular |
0 |
|
|
≥4cm |
1 |
Yes |
1 |
Non-lifting/
previous attempt |
1 |
Non-granular |
1 |
|
|
Table 1| SMSA score and SMSA+ score.
* Direct ileocecal valve involvement/diverticulum involvement/anorectal junction / appendiceal orifice involvement/ location at flexures
Figure 3: Example of undertaking a polypectomy beyond the performing endoscopists’ competency a Spurting intra-procedural bleeding. b Attempt at clip placement for bleeding (note device extended far from the endoscope and preventing visualisation of the exact bleeding point). c Persistent bleeding after placement of the first clip. d Multiple clips with persistent oozing bleeding and impeding the possibility for further resection in this area. See also Mistake 5.
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