| Time after Surgery | Different Genotype COMT | N | EWL Mean (SD) | Time after Surgery | Different Genotype COMT | N | EWL Mean (SD) |
| 2008-2010 (short-term) | AA | 8 | 28.62 (15.27) | 2004-2007 (long-term) | AA | 20 | 45.35 (29.43) |
| GA | 13 | 47.86 (17.51) | GA | 17 | 41.78 (16.09) | ||
|
| GG | 6 | 23.62 (12.72) |
| GG | 10 | 42.21 (23.02) |
|
| TOTAL | 27 | 36.77 (18.90) |
| TOTAL | 47 | 43.39 (23.55) |