The Analgesic Efficacy of the Pectoral Nerves Block Versus Local Anesthetic Infiltration After Mastectomy

The Analgesic Efficacy of the Pectoral Nerves Block Versus Local Anesthetic Infiltration After Mastectomy: a Randomized, Controlled, Double Blinded Trial

This trial will include patients undergoing radical mastectomy under general anesthesia. One group of patients will receive a pectoral nerve block, done by the anesthetist under ultrasound guidance at the beginning of the invervention. The other group will receive the a wound infiltration at the end of the intervention, done by the surgeon. Investigators will compare acute pain-related outcomes and chronic pain at 3 and 6 months postoperatively.

Mastectomies are associated with moderate to severe postoperative pain. In addition to general anesthesia, different methods of locoregional anesthesia exist to treat postoperative pain, amongst others a pectoral nerve block. This block consists in injecting local anesthetic between the muscles of the thoracic wall and is done under ultrasound guidance. Over the last few years, the pectoral nerves block has become a recognized option for the treatment of acute post-mastectomy pain and it is routinely performed in addition to general anesthesia.

Data indicates that pectoral nerve blocks are effective for the treatment of postoperative pain during the first 24 hours after mastectomy, when compared to no block. However, the analgesic efficacy of a pectoral nerve block has never systematically compared to that of wound infiltration with local anesthetics, done by the surgeon at the end of the intervention. Such an infiltration is also currently employed.

In our study randomize patients undergoing mastectomy under general anesthesia will be randomized to receive either an ultrasound-guided pectoral nerve block with 30 mL of local anesthetic (group PECS) or a wound infiltration with 30 mL of local anesthetic (group infiltration).

Investigators will assess different pain-related outcomes over the first 24 postoperative hours, together with potential block-related side effects and patient satisfaction. Chronic postoperative pain at 3 and 6 months postoperatively will also be assessed.

Both patients and outcome assessors will be blinded to group allocation.

Inclusion Criteria:

• Patients undergoing unilateral mastectomy
• American Society of Anesthesiology Physical Status I-III
• Age ≥ 18

Exclusion Criteria:

• Contraindications to regional anesthesia, such as infection at the surgical site
• Pregnancy
• History of alcohol or drug dependence/abuse
• History of long term opioid intake
• Chronic pain disorder