Intramuscular Stimulation Reduced Postoperative Thoracotomy Pain and Opioid Use

Needle electrical twitch intramuscular targeting the retracted intercostal muscles reduced pain after thoracotomy.

A novel intramuscular stimulation approach targeting retracted intercostal muscles was found to effectively alleviate postoperative pain after thoracoscopic surgery. These findings were published in The Journal of Thoracic and Cardiovascular Surgery.

This randomized trial was conducted between 2018 and 2020 at the Gangnam Severance Hospital in South Korea. Patients (N=77) undergoing video-assisted thoracoscopic surgery (VATS) pulmonary resection were randomized in a 1:1 ratio to receive needle electrical twitch obtaining intramuscular stimulation (NETOIMS; n=36) or intravenous (IV) patient-controlled analgesia (PCA) with fentanyl (n=41).

The NETOIMS intervention was applied on the retracted intercostal muscle after the main VATS procedure before skin closure. The primary outcomes were postoperative pain on a numeric rating scale (NRS) and opioid consumption through postoperative day 5.

The NETOIMS and IV-PCA cohorts were aged mean 59.5 (interquartile range [IQR], 49.0-65.8) and 51 (IQR, 39.5-66.0) years, 47.2% and 53.7% were men, 58.3% and 53.7% underwent wedge resection, 33.3% and 34.1% underwent lobectomy, 8.3% and 12.2% underwent segmentectomy, and the procedure lasted 75.8 (standard deviation [SD], 45.5) and 74.6 (SD, 47.8) minutes, respectively.

Pain scores were lower on postoperative day 0 (mean, 5.31 vs 6.15; P <.01), day 2 (mean, 1.51 vs 2.36; P <.001), day 4 (mean, 1.01 vs 1.84; P <.001), and day 5 (mean, 0.54 vs 1.73; P =.01) among NETOIMS recipients. Based on these trends in pain reduction, the investigators predicted the time to pain resolution would be 13.4 days for the NETOIMS cohort and 21.8 days for the IV PCA group.

Fewer of the NETOIMS cohort received IV nonsteroidal antiinflammatory drugs (NSAIDs; 5.6% vs 70.7%; P <.001), IV opioids (22.2% vs 48.8%; P =.026), and oral NSAIDs (8.3% vs 34.1%; P =.006). In addition, numerically fewer patients in the NETOIMS cohort received oral opioids, although the difference was not significant (27.8% vs 43.9%; P =.142).

The NETOIMS cohort was associated with lower oral opioid consumption on postoperative day 0 (mean morphine milligram equivalent [MME], 13.72 vs 131.28; P <.001) and one (mean MME, 16.35 vs 134.37; P <.001).

The NETOIMS cohort was associated with fewer side effects (P <.001). The NETOIMS recipients reported nausea or vomiting (n=7) and the IV-PCA recipients reported nausea or vomiting (n=28), sleeping tendency (n=9), dizziness (n=6), and urinary retention (n=2).

This study was limited by its small sample size and lack of treatment blinding.

The results of this study support the use of NETOIMS to reduce VATS postoperative pain scores and opioid consumption.

“We believe that [this study] is of high clinical importance since it provides an academic basis for significantly reducing the use of opioids after thoracotomy,” the study authors concluded.


Moon DH, Park J, Park YG, et al. Intramuscular stimulation as a new modality to control postthoracotomy pain: A randomized clinical trial. J Thorac Cardiovasc Surg. 2022;S0022-5223(22)00243-4. doi:10.1016/j.jtcvs.2022.02.047