Letters to the Editor
We thank De Cassai and Ban1 for the thoughtful reply to our case presentation2 and for highlighting the breast and axilla innervation. The aim of our case presentation was to demonstrate the efficacy of the erector spinae plane (ESP) block as a complete anesthesia technique for a patient undergoing modified radical mastectomy.
We agree that the ESP block provides anesthesia to the intercostal nerves when the block is performed at the T5 level, but its effect is not limited to these nerves. Its mechanism of action is likely linked to the transforaminal and epidural spread of local anesthesia,3 which may be a potential advantage over other thoracic interfascial plane blocks. However, ESP blocks do not block the medial or lateral pectoral nerves or the long thoracic and thoracodorsal nerves.
An ESP block may not provide adequate analgesia for surgeries in which subpectoral prosthesis and expander placement are performed; rather, a pectoral plane (PECS) I block may be required. One question that remains when using the PECS I block for breast surgery is how a sensory block is obtained when attempting to block the pectoral nerves, which are motor nerves innervating the pectoral muscles. A recent, randomized, double-blind trial showed that PECS I was not better than a saline placebo in the presence of multimodal analgesia for breast cancer surgery.4 It is an interesting study, but we respectfully disagree with the inclusion of many different types of surgical interventions in the trial because, in some surgeries, a PECS I block is not justifiable to provide better analgesia. Mastectomies can be conducted using substantially different surgical approaches that will change the appropriate anesthetic technique.
Recently, Forero et al5 published a study that demonstrated the analgesic efficacy of the ESP block performed at the T2/T3 level for chronic shoulder pain. It is postulated that both cephalad and caudad local anesthetic spread are facilitated by the thoracolumbar fascia as it is deep to the erector spinae muscle. However, spreading of local anesthetic up to the brachial plexus with an ESP block at T5 is unlikely.
For our patient, the contribution of the brachial plexus was probably less important because we obtained satisfactory anesthetic effect with the ESP block. It is possible that we are placing more importance on the brachial plexus than it has in reality for breast surgery. Further studies are necessary to understand whether this is an unnecessary precaution.
Pedro Paulo Kimachi, MD
Elaine Gomes Martins, MD, CIPS
Department of Anesthesia
Instituto de Ensino e Pesquisa
Hospital Sírio Libanês
São Paulo, Brazil
1. De Cassai A, Ban IIs selective brachial plexus block necessary after erector spinae plane block in breast surgery? A A Pract. 2018;11:261.
2. Kimachi PP, Martins EG, Peng P, Forero MThe erector spinae plane block provides complete surgical anesthesia in breast surgery: a case report. A A Pract. 2018; [epub ahead of print].
3. Schwartzmann A, Peng P, Maciel MA, Forero MMechanism of the erector spinae plane block: insights from a magnetic resonance imaging study. Can J Anesth. 2018;43:596604. doi:10.1007/s12630-018-1187-y.
4. Cros J, Sengès P, Kaprelian SPectoral I block does not improve postoperative analgesia after breast cancer surgery: a randomized, double-blind, dual-centered controlled trial. Reg Anesth Pain Med. 2018;43:596604.
5. Forero M, Rajarathinam M, Adhikary SD, Chin KJErector spinae plane block for the management of chronic shoulder pain: a case report. Can J Anesth. 2018;65:288293.