A Novel Technique for Postoperative Analgesia in Video-Assisted Thoracoscopic Surgery: “A Modified Pectoral Nerve Block”

Abstract

VIDEO-ASSISTED thoracoscopic surgery (VATS) has become the most common minimally invasive surgical technique for anatomic resection of early-stage lung cancer.1Ng CSH MacDonald JK Gilbert S et al.Expert consensus statement on optimal approach to lobectomy for non-small cell lung cancer.Innovations. 2019; 14: 87-89Crossref PubMed Scopus (6) Google Scholar VATS allows for smaller incisions with fewer chest-wall traumas and less impact on respiratory mechanics, which have been shown to result in shorter hospital length of stay, lower rates of pulmonary complications, and less postoperative pain when compared with thoracotomy.2Power AD Merritt RE Abdel-Rasoul M et al.Estimating the risk of conversion from video-assisted thoracoscopic lung surgery to thoracotomy-a systematic review and meta-analysis.J Thorac Dis. 2021; 13: 812-823Crossref PubMed Google Scholar A multimodal analgesic approach including regional blocks has been recommended for thoracic surgery including VATS, using the enhanced recovery after lung surgery protocol.3Batchelor TJP Rasburn NJ Abdelnour-Berchtold E et al.Guidelines for enhanced recovery after lung surgery: Recommendations of the Enhanced Recovery After Surgery (ERAS) Society and the European Society of Thoracic Surgeons (ESTS).Eur J Cardiothorac Surg. 2019; 55: 91-115Crossref PubMed Scopus (266) Google Scholar At the present time, there are multiple approaches for postoperative pain control after VATS, including the use of thoracic epidural analgesia,4Sztain JF Gabriel RA Said ET. Thoracic epidurals are associated with decreased opioid consumption compared to surgical infiltration of liposomal bupivacaine following video-assisted thoracoscopic surgery for lobectomy: A retrospective cohort analysis.J Cardiothorac Vasc Anesth. 2019; 33: 694-698Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar intercostal blocks,5Campos JH Peacher D. Choosing the best method for postoperative regional analgesia after video-assisted thoracoscopic surgery.J Cardiothorac Vasc Anesth. 2020; 34: 1877-1880Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar anterior erector spinae blocks, serratus plane blocks, and thoracic paravertebral blocks (TPVB).6Ciftci B Ekinci M Celik EC et al.Efficacy of an ultrasound-guided erector spinae plane block for postoperative analgesia management after video-assisted thoracic surgery: A prospective randomized study.J Cardiothorac Vasc Anesth. 2020; 34: 444-449Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar,7D'Ercole F Arora H Kumar PA. Paravertebral block for thoracic surgery.J Cardiothorac Vasc Anesth. 2018; 32: 915-927Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar In addition, newer local anesthetics also have been used in VATS.8Campos JH Seering M Peacher D. Is the role of liposomal bupivacaine the future of analgesia for thoracic surgery? An update and review.J Cardiothorac Vasc Anesth. 2020; 34: 3093-3103Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar Thoracic epidural analgesia and TPVB have been considered the gold standard for early postoperative pain control management after thoracic surgery. However, the roles of thoracic epidural analgesia and TPVB after VATS remain controversial.8Campos JH Seering M Peacher D. Is the role of liposomal bupivacaine the future of analgesia for thoracic surgery? An update and review.J Cardiothorac Vasc Anesth. 2020; 34: 3093-3103Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar The ideal regional block for a minimally invasive thoracic surgery such as VATS should be easy technically to place, be guided with ultrasonography, provide effective analgesia, and have no complications; unfortunately, there is no such block at the present time. Each regional block technique has its advantages and disadvantages. Some regional blocks have reported some major complications; therefore, a newer block with minimal or no complications would be ideal. Fascial plane blocks have begun to be favored in thoracic surgery, particularly for minimally invasive surgery such as VATS.9Franco CD Inozemtsev K. Refining a great idea: The consolidation of PECS I, PECS II and serratus blocks into a single thoracic fascial plane block, the SAP block [e-pub ahead of print].Reg Anesth Pain Med. 2019; (Accessed)https://doi.org/10.1136/rapm-2019-100745Crossref Scopus (11) Google Scholar,10Luo G Zhu J Ni H et al.Pretreatment with pectoral nerve block II is effective for reducing pain in patients undergoing thoracoscopic lobectomy: A randomized, double-blind, placebo-controlled trial.Biomed Res Int. 2021; 20216693221Crossref PubMed Scopus (2) Google Scholar In this issue of the Journal, Yildirim et al.11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar described a study of a relatively novel regional block, the modified pectoral nerve (PEC) block, and compared this with the TPVB by using an ultrasonography guidance technique in VATS. In this prospective randomized trial, their primary objective was the duration of analgesia by using 30 mL of bupivacaine 0.375%, along with their consumption of morphine; the secondary outcome was the amount of intraoperative opioid used (remifentanil) or other drugs considered a rescue analgesic. The Yildirim, et al. study11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar showed that the PEC block had similar analgesic effect when compared with TPVB after VATS. This is not surprising considering a similar study with a different block involving continuous analgesia in a serratus anterior plane block versus TPVB for VATS.12Hanley C Wall T Bukowska I et al.Ultrasound-guided continuous deep serratus anterior plane block versus continuous thoracic paravertebral block for perioperative analgesia in videoscopic-assisted thoracic surgery.Eur J Pain. 2020; 24: 828-838Crossref PubMed Scopus (19) Google Scholar The study of Yildirim et al.11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar included 52 patients. In estimating the power calculation, a pilot study of 20 patients (ten in each arm group) was included, with the primary objective a 20% reduction in morphine consumption. It is interesting that the larger randomized control study did not have the same results. This may have been due to an underpowered study. This research should be studied further with a larger study to confirm these results. Yildirim et al.11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar determined that block analgesia occurred when the first patient-controlled analgesia (PCA) was used after block administration. It is interesting that their study only showed block analgesia duration by their definition to be two hours in the PEC group versus 2.8 hours in the TPVB group. There was a longer duration of action for these blocks regarding breast surgery studies and many patients did not require opioids for the first 24 hours. In the Yildirim et al. study,11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar blocks were placed after induction of anesthesia and before the surgical procedure. In looking at their operating room time for surgeries, it did show that most PEC block patients required PCA within 20 minutes of surgery conclusion, while in the TPVB patients it was 50 minutes; however, neither of these times was statistically significant. The missing component in this study was the location of the pain for these patients in the different groups. Each block has a dermatomal distribution and will have some areas that are not adequately covered for the nerve blocks. A TPVB is a nerve blockade of ipsilateral somatic and sensory nerves. This results in no upper extremity motor blockade. The spread of dermatomes is unreliable and may depend on the amount of local anesthetic used. Larger-volume single injections (20-30 mL) have a high incidence of ipsilateral and contralateral epidural spread. This can be attributed to the hypotension seen after this nerve block. Conversely, PEC blocks reliably work on blocking ipsilateral chest and axilla regions. It does this by blocking several main nerves in the chest region, the pectoral, intercostal brachial, lateral branches of intercostals one-to-six, lung thoracic and thoracodorsal nerves. With these known regions, the area of the chest is blocked for thoracic surgery as well as breast surgery. For PEC blocks, these anatomic areas of the body for blocks have a faster local metabolism than distal sites. The Yildirim et al. study11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar used 30 mL of 0.375% bupivacaine; this is a relatively higher concentration of intermediate-acting local anesthetic compared with 0.25% ropivacaine used in many PEC block studies. Although the evaluation of pain assessment in the postoperative period was done using the visual analog scale (VAS), it may have been a more specific assessment to note where the patient experienced pain when requesting additional pain modalities. With limitations to block coverage as stated above, pain at the incision, shoulder, or chest tube sites have very different meanings.13Campos JH Seering M. Does the analgesic technique in the intraoperative period have any influence on chronic pain after uniportal video-assisted thoracoscopic surgery?.J Cardiothorac Vasc Anesth. 2020; 34: 992-994Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar Furthermore, analgesia from the block can continue with pain at these sites. In many cases, the chest tube site in VATS can be infiltrated with local anesthetics by the surgeon. It was not mentioned in this study if that was done as part of the multimodal approach. Without a measurement of an early block success, it is difficult, at best, to estimate the exact duration of the block. Because the patients had their block placed after induction of anesthesia, sensory loss could not determine where to place the block. In addition, it is difficult to estimate block failure rates without this important test shown. Previous studies have shown that more invasive surgical resection usually is prone to more pain; it is hard to apply this study to all VATS surgery; especially given the fact that most of their enrolled subjects had wedge resections as opposed to lobectomies. In addition, considering the clinical aspects of the regional blocks in this study (PEC and TPVB), their patients’ body mass index was within normal weight population, and it is possible that this novel recommended technique might have different results in obese or morbidly obese patients with a body mass index >40 Kg/m2. An interesting prospective, randomized double-blind study included the use of pectoral nerve block II (PEC II) in patients undergoing thoracoscopic lobectomy, in which one group of 20 patients received 25 mL of 0.5% ropivacaine before general anesthesia and a comparative group of 20 patients that received only placebo (saline 0.9%). Luo et al.10Luo G Zhu J Ni H et al.Pretreatment with pectoral nerve block II is effective for reducing pain in patients undergoing thoracoscopic lobectomy: A randomized, double-blind, placebo-controlled trial.Biomed Res Int. 2021; 20216693221Crossref PubMed Scopus (2) Google Scholar performed a pin-prick test 30 minutes after the block was performed and allowed analysis of the place of sensory disappearance. According to their report, the plane of sensory disappearance reached thoracic (T) T2 in 18 patients and T6 in 12 patients who received ropivacaine. Their conclusions indicated that PEC II block prolonged the time to the first analgesic request, alleviated the pain of surgical incision and reduced opioid consumption in VATS. This study already was published and contradicted the statement by Yildirim et al.,11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar in which a claim was made that their study was the first to use PEC in VATS.10Luo G Zhu J Ni H et al.Pretreatment with pectoral nerve block II is effective for reducing pain in patients undergoing thoracoscopic lobectomy: A randomized, double-blind, placebo-controlled trial.Biomed Res Int. 2021; 20216693221Crossref PubMed Scopus (2) Google Scholar In addition, the study by Yildirim et al.11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar had 40-to-50 minutes of additional anesthesia time when compared with their surgical time. As we are aware that operating room time is a vital resource in many institutions, it would have been relevant to include the duration of the time to place the blocks. With TPVB being two injection sites and the PEC block being done under a single injection, one would imagine that block placement duration had different times. Although VAS scores at rest and within movement appeared consistent across both groups, it would have been beneficial to know change in pain with each patient rather than raw VAS numbers. Unfortunately, VAS scores have no objective confirmation test. A change from 0-to-4 (4-point change) and 3-to-4 (1-point change) are very real differences in pain over time versus looking at a single pinpoint-in-time score. Finally, a meaningful calculation for pain medications may have been in morphine-milligram equivalent. In this study by Yildirim et al.,11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar these calculations were not done, and the opioids were administered based on weight. This means patients who are 60 kg and 85 kg respectively will receive different remifentanil and induction of PCA dosing. This makes comparisons difficult at best in this regard. If all patients in this study had morphine-milligram equivalent calculated looking at remifentanil, fentanyl, and morphine PCA, this would have been a standard opioid measurement to compare with other studies. Yildirim et al.11Yildirim K Sertcakacilar G Hergunsel GO. Comparison of the results of ultrasound-guided thoracic paravertebral block and modified pectoral nerve block for postoperative analgesia in video-assisted thoracoscopic surgery; a prospective, randomized controlled study [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2021; (Accessed)https://doi.org/10.1053/j.jvca.2021.08.014Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar have tested a novel regional block, the modified PEC, used as a part of multimodal analgesia for VATS patients. Although the study was underpowered, was done in a single institution, the blocks were performed by a single anesthesiologist, and considering the limitations discussed previously in addition to their results, it is possible that the PEC might have some advantages over other blocks, including TPVB. It is considered a superficial fascial block, requires a single injection of local anesthetic, can be guided with ultrasonography, is done in a supine position; and, according to their results, the patients had fewer hypotension episodes when compared with TPVB. In contrast, TPVB requires multiple injections and potentially causes more episodes of hypotension. The overall complications related to the techniques itself were not present in the groups studied. We appreciate Dr. Yildirim et al. for their interesting study in which modified PEC blocks compared with TPVB had similar outcomes in the postoperative period when used in multimodal analgesia protocol. Larger studies and comparison with different local anesthetics (eg, liposomal bupivacaine) are needed to define the role of the novel block in VATS, including thoracic trauma surgery.14Jack JM McLellan E Versyck B et al.The role of serratus anterior plane and pectoral nerves blocks in cardiac surgery, thoracic surgery and trauma: A qualitative systematic review.Anaesthesia. 2020; 75: 1372-1385Crossref PubMed Scopus (18) Google Scholar None.