Combined erector spinae plane block with surgical intercostal nerve cryoablation for Nuss procedure
Myron Yaster MD, Rita Agarwal MD, and Karen Boretsky MD
It’s summertime: baseball, hot dogs, backyard BBQs, suntan lotion, school vacation, and if you are a pediatric anesthesiologist (and why else would you be reading this?), pectus excavatum surgical repair time. In 2024, the Nuss procedure is the standard of care for the surgical repair of pectus excavatum. A minimally invasive procedure, compared to it’s predecessor, the Nuss procedure is extremely painful and perioperative pain protocols include multimodal intravenous analgesics, neuraxial and peripheral nerve block analgesia (including paravertebral and intercostal nerve blocks), and, increasingly, cryoablation.1-3 Cryoablation has been a game changer but it takes about 24 hours for cryoablation to begin to produce its analgesic effects. Today’s PAAD by Aranda-Valderrama et al.1 discusses one method to bridge the analgesic gap by using erector spinae plane (ESP) blocks.
For those of you who are new to the specialty you may be wondering why pectus excavatum surgery is primarily a summer procedure? Primarily because historically, it is so painful, parents (and surgeons) electively schedule the repair for the summer to avoid missing several weeks of school time. Thus, because it’s summertime, today’s PAAD comes at the perfect time. Myron Yaster MD
Original article
Aranda-Valderrama P, Greenberg RS, Vecchione TM, Finney AG, Prichett LM, Vanderhoek SM. Combined erector spinae plane block with surgical intercostal nerve cryoablation for Nuss procedure is associated with decreased opioid use and length of stay. Reg Anesth Pain Med. 2024 Apr 2;49(4):248-253. doi: 10.1136/rapm-2023-104407. PMID: 37407278.
Today’s study, is a single institution (the Johns Hopkins Hospital) retrospective analysis of the results of adding ESP blocks to their previous multi-modal ERAS pain regimen that included the kitchen sink: “patient-controlled bolus-only intravenous opioid analgesia, low-dose adjunctive ketamine infusion (0.1mg/kg/hour), gabapentin, scheduled acetaminophen and ketorolac, and diazepam as needed.”1 Thus, they compared before and after effects of the addition of the ESP blocks on total opioid use in morphine equivalents, pain scores, and length of stay (LOS).
Let’s very briefly review cryoablation and the ESP block. What is cryoablation? “Temperatures between −60 and −70°C are applied to intercostal nerve bundles and cause Wallerian degeneration of nerve axons to induce a period of paresthesia.”1,4,5 There is a fantastic video of this technique on the Society for Pediatric Pain Medicine Visual Pearls site. Look for December 2022 Intercostal Cryotherapy at: https://pedspainmedicine.org/education/sppm-visual-pearls/. No long-term adverse effects have been identified. The main limitation of cryoablation is the onset time of roughly 24 hours which creates an analgesic gap in the immediate postoperative period. The optimal strategy for managing this period is not defined.
The ESP block is a relatively novel fascial plane peripheral nerve block developed for the management of thoracic pain and consists of injecting local anesthetic deep to the erector spinae muscle to achieve a multi-dermatomal sensory block.6 The mechanism of action is unclear and the efficacy of the ESP block is debated but it is relatively safe and the landmarks are easy to identify making it relatively easy for less skilled practitioners to perform. The patient must be turned lateral for insertion (add 15-20 minutes to your OR time) and the block should be performed at the beginning of surgery to avoid the hypothetical possibility of disrupting the new hardware at the end.
OK, what did they find? “… the addition of bilateral single injection ESP blocks at T6 to surgeon performed cryoablation reduced opioid consumption without a change in subjectively reported pain scores.” Is this a definitive study? Absolutely not. It is a retrospective, nonrandomized, single center study in which many of the data points were limited to what could be found in the hospital record. As with any retrospective observational study, readers are unable to factor in the temporal effects of preexisting trends towards earlier discharge as well as placebo effects and clinician bias. It should be thought of as a pilot study to provide effect size estimates to guide the design of future randomized trials. Optimistically, we take one step closer to defining the optimal pain management regimen.
What are the authors’ personal experiences with ESP blocks? At one Institution (KB at Boston Children’s Hospital), the initial enthusiasm for the ESP has cooled after positive retrospective data was used to power a randomized prospective trial which failed to demonstrate any statistical advantage to adding an ESP block for surgeries utilizing sternotomy incisions. My (KB) choice for NUSS procedures remains the more reliable, better studied paravertebral block. Our (RA) choice at the Lucile Packard Children’s Hospital, working with our surgeons to refine ERAS protocols to optimize analgesia and minimize hospital stay, initially started with the use of ESP catheters but has evolved to surgeon administered bupivacaine plus liposomal bupivacaine at the same anatomic locations that they are performing cryotherapy. Our (KB and RA) ERAS “kitchen sink” protocols also include gabapentin, acetaminophen , ketorolac and oral oxycodone as needed.
Are you using cryoablation in your practice? Are you adding other regional anesthetic techniques to bridge the time till cryoablation takes full effect? Are you using other multi modal analgesic techniques in your practice? Do you follow these patients days to weeks after their procedure? Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Aranda-Valderrama P, Greenberg RS, Vecchione TM, Finney AG, Prichett LM, Vanderhoek SM. Combined erector spinae plane block with surgical intercostal nerve cryoablation for Nuss procedure is associated with decreased opioid use and length of stay. Regional anesthesia and pain medicine 2024;49(4):248-253. (In eng). DOI: 10.1136/rapm-2023-104407.
2. Chidambaran V, Garcia VF, Brown RL. Are We Ready for Cryoablation in Children Undergoing Nuss Procedures? Anesthesia and analgesia 2022;134(4):881-884. (In eng). DOI: 10.1213/ane.0000000000005857.
3. Lai K, Notrica DM, McMahon LE, et al. Cryoablation in 350 Nuss Procedures: Evolution of Hospital Length of Stay and Opioid Use. J Pediatr Surg 2023;58(8):1435-1439. (In eng). DOI: 10.1016/j.jpedsurg.2022.10.051.
4. Graves CE, Moyer J, Zobel MJ, et al. Intraoperative intercostal nerve cryoablation During the Nuss procedure reduces length of stay and opioid requirement: A randomized clinical trial. J Pediatr Surg 2019;54(11):2250-2256. (In eng). DOI: 10.1016/j.jpedsurg.2019.02.057.
5. Linton SC, Tian Y, Zeineddin S, et al. Intercostal Nerve Cryoablation Reduces Opioid Use and Length of Stay Without Increasing Adverse Events: A Retrospective Cohort Study of 5442 Patients Undergoing Surgical Correction of Pectus Excavatum. Annals of surgery 2024;279(4):699-704. (In eng). DOI: 10.1097/sla.0000000000006113.
6. Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The Erector Spinae Plane Block: <em>A Novel Analgesic Technique in Thoracic Neuropathic Pain</em>. Regional Anesthesia & Pain Medicine 2016;41(5):621-627. DOI: 10.1097/aap.0000000000000451.