Serratus anterior plane block for upper abdominal incisions has been previously reported

We have read carefully the case report from Tiwari et al. entitled ‘Serratus anterior plane block for upper abdominal incisions’. ¹ They state there have not been any reports of this technique being used to provide analgesia for upper abdominal incisions, but this is not the case and their approach is not novel. A similar concept was described and published in 2015: ‘The modified serratus–intercostal plane block as an analgesic technique in open cholecystectomy’. ²

Serratus–intercostal block (cutaneous branches block in the mid-axillary line) and serratus anterior plane block were described in 2013 as analgesic techniques in breast and thoracic-wall surgeries. Placing the local anaesthetic in the inter-fascial plane between the external intercostal and serratus anterior muscles or below the serratus anterior muscle, respectively, achieves the same aim: blocking the cutaneous branches of the intercostal nerves.

As the authors described, the upper abdominal wall is innervated by the T7–T11 intercostal nerves. Based on our previous experience performing the serratus–intercostal block in breast surgery, we chose a lower approach. With the patient lying supine, an 80-mm echogenic needle is introduced from caudad to cephalad, in plane, until the tip lies adjacent to the eighth rib where the local anaesthetic (LA) is deposited between the external intercostal and the serratus anterior muscles (Figure 1). The diffusion of LA in this fascial plane blocks the cutaneous branches of the intercostal nerves, providing adequate analgesia for upper abdominal surgery.^3,4 Our results from 100 patients of satisfactory opioid-sparing ⁵ are confirmation that a thoracic block can be the solution to perioperative pain management in the upper abdominal wall. ⁶

Figure 1.

Ultrasound image. C8: 8th rib; mic: intercostal muscles; ms: serratus muscle; LA: diffusion of local anaesthetic.

We applaud the initiative of the authors to place the catheter below the serratus anterior muscle. They achieved a good result, but we suggest that better analgesia could be achieved by placing the catheter at a lower level.