Randomization, allocation concealment and blinding

The randomization was performed by an independent statistical professional. The statistician initially generated a simple random number sequence, without groups, using the Bio Estat program, version 5.3, with 150 numbers and their respective groups (M or E). With the patient allocation order in hand, he prepared 150 opaque envelopes with the sequential numbering written on the outside and the allocation (M or E) on a paper inside. Every time a patient was admitted to the surgical ward for the operation, a nurse in the operating room had to open each envelope, respecting the sequence number. The surgeon (principal researcher) was only then informed about the allocation. The allocation had to be revealed at this point so that the surgeon could immediately request the hospital pharmacy to send the IPCD to the operating room so that it could be applied immediately at the end of the surgery.

The physical therapist measuring the limb circumference for edema evaluation (primary outcome) could not be blinded at the measurement after surgery, as the IPCD is visible and was not removed. Patients could not be blinded either for the same reason.