To the Editor,

Providing adequate postoperative analgesia and preventing back muscle spasms after posterior spinal fusion for adolescent idiopathic scoliosis (AIS) remains a challenge.1 With patient assent and parental written consent, we report our experience of a patient with AIS who had excellent post-spinal fusion pain control and absence of back spasms with the use of surgically placed bilateral erector spinae plane catheters (SP-EC).

A 16 yr-old, 70-kg healthy female with a 56° Lenke 1A (right main thoracic) scoliosis underwent T4–T12 posterior spinal instrumentation. After general anesthesia induction, normal baseline somatosensory-evoked potentials (SSEPs) and transcranial motor-evoked potentials (TCMEPs) were obtained. The anesthetic was maintained with 0.1–0.5% sevoflurane, ketamine 0.3–0.5 mg·kg−1·hr−1, and propofol 50–100 μg·kg−1·min−1. Facetectomies were performed and two ponte osteotomies were performed at T7–8 and T9–10. Predominantly pedicle screw instrumentation was used. At the conclusion of surgery, bilateral SP-ECs (E-Cath 83 mm, Pajunk, Germany) were inserted percutaneously above the incision site with the tips on top of the T6 transverse processes (Figure). Once the fascial and paraspinal muscles were closed, a 20-mL bolus of lidocaine 0.5% was given via each catheter. Somatosensory-evoked potentials and TCMEPs were monitored for 30 min during and after the remainder of closure. No surgical drains were placed. Somatosensory-evoked potentials and TCMEPs remained at baseline throughout the pre- and post-local anesthetic (LA) bolus time periods. Intraoperatively, a total of 100 μg fentanyl and hydromorphone 2.4 mg iv were administrated prior to LA. In the recovery room, the patient woke up and reported no pain at rest or with movement. Postoperatively, alternating left- and right-sided boluses with 20 mL of 0.5% lidocaine were administered every 60 min via an automated pump. She was put on intravenous hydromorphone patient-controlled analgesia and continued on scheduled acetaminophen. Overnight, the patient reported a peak pain score of 5/10 and utilized a total of 1.7 mg hydromorphone. After increasing the bolus to 22 mL and allowing a few hours of sitting up on the morning of postoperative day (POD) 1, the patient was comfortable with a pain score of 0–2/10 throughout the day. The patient was able to fully participate in physiotherapy and reached all pertinent recovery milestones. Serum lidocaine levels were 0.9 μg·mL−1 (POD 0) and 1.1 μg·mL−1 (POD 1). Patient was then started on an oral multimodal regimen of oxycodone, ibuprofen, and methocarbamol as needed on POD 1. The patient began walking on POD 1 and was discharged after catheter removal on the morning of POD 2. Following discharge, her pain remained well controlled with oral medication.

Figure
figure 1

Bilateral surgically placed erector spinae plane catheter (SP-EC). Catheters placed percutaneously above the incision sites at approximately T2–3 level with the catheter tip tunnelled next to T6 pedicle screws. Bottom: x-ray images taken at preoperative and intraoperative x-ray images captured after instrumentation completed and prior to the insertion of the catheters and surgical closure in prone position. ESM = erector spinae muscle.

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This is the first description of SP-ECs used for analgesia and prevention of muscle spasms after posterior spinal fusion for AIS. In contrast to typical experiences with increased pain and back spasms during initial mobilization, our patient reported minimal pain and no posterior muscle spasms with activity. The pain during the first night may have been due to inadequate spread of the LA while in a supine position. The following morning, discomfort greatly improved upon sitting up and mobilizing likely because gravity facilitated the caudal spread of LA under the erector spinae muscle (ESM) along the incision site via the surgically opened erector spinae plane channel. Unlike epidural catheters associated with occasional motor blockade,2 SP-ECs may directly block the dorsal rami of spinal nerves innervating the corresponding posterior ESMs and incision sites without causing intraoperative SSEP/TCMEP changes and postoperative motor weakness.3,4,5 To ensure proper placement and minimize infection risk, the surgical team placed the catheters under direct visualization within the sterile field. Further studies are needed to clarify the optimal LA dosage of SP-ECs for varying fusion lengths.