Which is more painful? A randomized trial comparing loop with laser excision of the cervical transformation zone

We compared the pain of excisional cervical surgery by the laser or loop diathermy (LLETZ) in a randomised controlled clinical trial. Eighty women with CIN III were recruited from a laser colposcopy clinic specifically adapted to run randomized trials. They were scheduled for excision of their cervical transformation zone and both groups were matched for age, parity, and size of lesion. We measured linear analogue pain scores, subjective pain scores, and operative time. The laser and loop diathermy inflicts similar discomfort and there is no detectable difference between the median pain scores of women in either group (P = 0.99). However, in the hands of an experienced surgeon it takes 4 min extra to excise the cervical transformation zone with a laser compared to loop diathermy. The average time from sitting in the chair to the end of the procedure was 13.02 min (SD 3.65) for the group allocated diathermy surgery compared to 17.30 min (SD 5.33) for a laser excision log transformed t(log transformed data) = 3.7 (P < 0.001).