The needle is advanced to the fascial plane between the muscle fascia of the rectus abdominis and the posterior layer of the rectus sheath (see picture)

Blanco R, Parras T, McDonnell JG, Prats-Galino A: Serratus plane block: a novel ultrasound-guided thoracic wall nerve block,
Anaesthesia 68: 1107-1113 (2013)

Midline incisions near the umbilicus

Midline trocar holes near the umbilicus

Umbilical surgery

Place the patient supine

Place the probe in the parasagittal plane on the midclavicular line and the fifth rib is identified by counting from above. The rib is tracked to the midaxillary line. Rotate the probe 45 degrees from the axial plane.

The latissimus dorsi, the serratus anterior and the teres major muscles are overlying the fifth rib (see previous page). The thoracodorsal artery can be used as a marker of the fascial plane between the latissimus dorsi and serratus anterior muscles.

The needle is inserted from the anterior end of the probe and advanced in-plane

Inject 25 mL ropivacain 0.2% into the fascial plane between the serratus anterior and latissimus dorsi muscles

The rectus sheath is made by the anterior aponeuroses of the lateral abdominal muscles (external and internal obliques and the transverse abdominis) that split into an anterior and a posterior layer that encloses the rectus abdominis muscle on each side

The two layers fuse on the medial side of the rectus muscle and attach to the linea alba

The anterior layer of the rectus sheath extends from the xiphoid process to the pubic symphysis

The posterior layer only extends 3-5 cm below the umbilicus to the socalled arcuate line; it is separated from the peritoneum by the transversalis fascia

The 9th, 10th, and 11th intercostal nerves and the epigastric blood vessels are sandwiched between the rectus abdominis muscle fascia and the posterior layer of the rectus sheath

Blockade of these nerves with a rectus sheath block produces periumbilical anaesthesia

The tendinous inscriptions of the rectus abdominis muscle are not attached to the posterior lamina of the rectus sheath

This means that local anaesthetic injected between the rectus abdominis muscle and the posterior lamina in theory can spread along the backside of the rectus abdominis muscle and anaesthetize the anterior cutaneous branches of the 9th, 10th and 11th intercostal nerves

The serratus plane block produces analgesia of the lateral thoracic wall including the axilla.

The indications of the serratus plane block are postoperative analgesia after surgery of:

– lateral thoracic wall

– breast

– axilla

The needle is inserted in-plane from the cranial end of the probe until the tip of the needle penetrates the infero-lateral margin of the minor pectoral muscle and enters the lower part of the axilla between the Gerdy’s ligament and the serratus anterior muscle

Blanco R: The

With the superficial serratus plane block, the needle tip is inserted into the fascial space between the serratus anterior muscle and the latissimus dorsi muscle caudad to the teres major muscle

Local anaesthetic injected into this fascial plane covers the thoracic intercostal nerves and their lateral cutaneous branches – and also the thoracodorsal nerve which innervates the latissimus dorsi muscle and the long thoracic nerve which innervates the serratus anterior muscle. The last mentioned nerves run alongside the thoracodorsal artery.

Blanco R, Parras T, McDonnell JG, Prats-Galino A (see ref.) have also described a serratus plane block with injection of local anaesthetic into the fascial plane deep to the serratus anterior muscle

This deeper serratus plane block also produces analgesia of the thoracic intercostal nerves and the lateral hemithorax; however, the analgesia of the deep block seems to last a shorter time than the superficial serratus plane block