Video assisted thoracic surgery (VATS) has recently been evaluated as the standard surgical procedure for lung surgery. The advantages of VATS procedures compared with open thoracotomy are rapid recovery, short hospital stay and low complication risk. Although VATS is less painful than thoracotomy, patients may feel severe pain during the first hours at postoperative period. Thoracic epidural analgesia (TEA) which is the gold standard analgesic technique after thoracotomy, is generally used for analgesia management after VATS. However, since the surgical technique and trauma between open surgery and VATS are different, the question of what should be the gold standard for analgesia management after VATS is a topic of discussion. Especially due to the difficult administration and adverse effect profile of TEA, the opinion of minimally invasive surgical procedures, requiring less invasive analgesic techniques is supported. Analgesia management is very important for these patients in postoperative period since insufficient analgesia can cause pulmonary complications such as atelectasis, pneumonia and increased oxygen consumption.

The ultrasound (US) guided erector spina plane (ESP) block is a novel interfacial plan block defined by Forero et al. at 2016. ESP block provides thoracic analgesia at T5 level and abdominal analgesia at T7-9 level. The ESP block contains a local anesthetic injection into the deep fascia of erector spinae. This area is away from the pleural and neurological structures and thus minimizes the risk of complications due to injury. Visualization of sonoanatomy with US is easy, and the spread of local anesthesic agents can be easily seen under the erector spinae muscle. Thus, analgesia occurs in several dermatomes with cephalad-caudad way. Cadaveric studies have shown that the injection spreads to the ventral and dorsal roots of the spinal nerves and creates sensory blockade in both posterior and anterolateral thorax. In the literature, it has been reported that ESP block provides effective analgesia after open heart surgery, breast surgery and ventral hernia repair in randomized controlled studies about ESP block efficiency for postoperative analgesia management. In some case series and case reports it has been reported that ESP block provides effective analgesia after thoracotomy and VATS. Furthermore, it has been reported that it provides effective analgesia in chronic and persistant pain syndromes of thorax.

The aim of this study is to compare US-guided continuous ESP block and TEA for postoperative analgesia management after VATS. The primary aim is to compare perioperative and postoperative opioid consumption and the secondary aim is to evaluate postoperative pain scores (VAS), adverse effects related with opioids (allergic reaction, nausea, vomiting), complications due to blocks (pneumothorax, hematoma), and the time period and number of attempt for blocks.

• Other: ESP block (Group A)
  US probe will be placed longitudinally 2-3 cm lateral to the T5 transvers process. From superior to inferior, three muscles will be visualized on the hyperechoic transverse process; trapezius (upper), rhomboideus major (middle), erector spinae (lower). The block needle will be inserted cranio caudal direction and then for correction of the needle 5 ml saline will be injected deep into the erector spina muscle fascia. Following confirmation of the correct position 20G catheter will be inserted 5 cm in caudal direction. 20 ml %0.25 bupivacaine will be administered for block.
• Other: TEA group (Group B)
  Local infiltration with 2% of lidocaine under the skin, in T4/T5 intervertebral space will be administered. An 18 G Tuohy needle will be inserted at T4/T5 intervertebral space to identify epidural space using the loss of resistance technique. 20G catheter will be inserted 3-4 cm in caudal direction in the epidural space. Bolus dose of 0.125% bupivacaine 10 ml will be administered through the catheter after the negative aspiration for blood or cerebrospinal fluid

• Active Comparator: Group ESPB = Erector spinae plane block group
  ESP block (Group ESP) will be performed in the preoperative block room.A continuous infusion of 0.125% bupivacaine at the rate of 4 ml/h infusion dose, 6 ml bolus dose and 30 min lockout time will be performed till 48 h postoperative period.
  Intervention: Other: ESP block (Group A)
• Active Comparator: Group TEA = Thoracic epidural analgesia group
  TEA will be performed in the preoperative block room.A continuous infusion of 0.125% bupivacaine at the rate of 4 ml/h infusion dose, 6 ml bolus dose and 30 min lockout time will be performed till 48 h postoperative period.
  Intervention: Other: TEA group (Group B)

• Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The Erector Spinae Plane Block: A Novel Analgesic Technique in Thoracic Neuropathic Pain. Reg Anesth Pain Med. 2016 Sep-Oct;41(5):621-7. doi: 10.1097/AAP.0000000000000451.
• Forero M, Rajarathinam M, Adhikary S, Chin KJ. Continuous Erector Spinae Plane Block for Rescue Analgesia in Thoracotomy After Epidural Failure: A Case Report. A A Case Rep. 2017 May 15;8(10):254-256. doi: 10.1213/XAA.0000000000000478.
• Nagaraja PS, Ragavendran S, Singh NG, Asai O, Bhavya G, Manjunath N, Rajesh K. Comparison of continuous thoracic epidural analgesia with bilateral erector spinae plane block for perioperative pain management in cardiac surgery. Ann Card Anaesth. 2018 Jul-Sep;21(3):323-327. doi: 10.4103/aca.ACA_16_18.
• Gürkan Y, Aksu C, Kuş A, Yörükoğlu UH, Kılıç CT. Ultrasound guided erector spinae plane block reduces postoperative opioid consumption following breast surgery: A randomized controlled study. J Clin Anesth. 2018 Nov;50:65-68. doi: 10.1016/j.jclinane.2018.06.033. Epub 2018 Jul 2.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) classification I-II
• Scheduled for lVATS under general anesthesia

Exclusion Criteria:

• Bleeding diathesis
• Receiving anticoagulant treatment
• Known local anesthetics and opioid allergy
• Infection of the skin at the site of the needle puncture
• Pregnancy or lactation
• Patients who do not accept the procedure