Comparison of Serratus Posterior Superior Intercostal Plane Block and Paravertebral Block for Post-Thoracotomy Pain Management

Thoracotomy is a commonly performed approach in thoracic surgery and is associated withsevere postoperative pain due to extensive tissue dissection and rib retraction.Inadequate control of postoperative pain may lead to serious complications, includingimpaired respiratory function, secretion retention, atelectasis, pneumonia, chronicpost‐thoracotomy pain syndrome, and reduced patient satisfaction . Therefore, identifyingeffective, safe, and sustainable analgesic strategies following thoracotomy is ofcritical importance for improving both patient comfort and clinical outcomes.Thoracic epidural analgesia (TEA) has long been considered one of the most widely usedtechniques for postoperative pain control in thoracic surgery. Although TEA provideseffective bilateral somatic and visceral analgesia, its clinical use is limited byseveral factors, including hypotension, urinary retention, motor blockade, epiduralhematoma, technical challenges, and the requirement for patient cooperation.Consequently, in addition to systemic analgesics, regional anesthesia techniques havebecome essential components of multimodal analgesia protocols in thoracic surgery . Thishas encouraged the development of alternative approaches that are less invasive,technically more feasible, and capable of providing comparable analgesic efficacy.Fascial plane blocks, such as paravertebral block (PVB), erector spinae plane block(ESPB), serratus anterior plane block, and serratus posterior plane blocks, have gainedincreasing attention because they can be performed within more superficial anatomicalplanes and are associated with a lower risk of complications . These techniques areparticularly considered safe alternatives in patients for whom epidural analgesia iscontraindicated or technically challenging .Thoracic paravertebral block (PVB), one of the techniques evaluated in the present study,provides effective control of both somatic and visceral pain through direct blockade ofthe thoracic spinal nerves. Despite its relatively deep anatomical location, PVB hasdemonstrated efficacy in numerous clinical settings and has been widely adopted inclinical practice. It has been successfully utilized in major thoracic procedures,including open thoracotomy, video‐assisted thoracoscopic surgery (VATS), breast surgery,management of rib fractures, and extensive thoracic operations such as pneumonectomy andlobectomy. However, due to its deep anatomical location, PVB is associated with technicalchallenges and potential complications, including pneumothorax and vascular injury .As an alternative approach, the Serratus Posterior Superior Intercostal Plane Block(SPSIPB) has emerged as a novel regional anesthesia technique offering a technicallysimpler and anatomically safer profile owing to its more superficial site ofadministration. This block is performed by injecting local anesthetic between theserratus posterior superior muscle and the second or third intercostal muscles. Followinginjection, the spread of local anesthetic may extend to the dorsal rami, lateralcutaneous branches of the intercostal nerves, and the paravertebral space. Consequently,SPSIPB can provide extensive sensory blockade covering dermatomes from T2 to T9 .The potential of SPSIPB to achieve broad dermatomal coverage and provide segmentalanalgesia comparable to that of PVB has been supported by cadaveric studies and caseseries reported in the literature. Anatomical and technical descriptions havedemonstrated that the sensory distribution of SPSIPB may extend from C3 to T10 dermatomes. Such extensive spread suggests that SPSIPB may provide effective analgesia for upperthoracic regions.The analgesic efficacy of SPSIPB has also been demonstrated in procedures involvinganatomical regions similar to thoracic surgery, including video‐assisted thoracoscopicsurgery (VATS), reduction mammaplasty, cardiac surgery, and pectus excavatum repair, asreported in several case studies and clinical reports. However, prospective studiesdirectly comparing SPSIPB and PVB in patients undergoing open thoracotomy remain limited.In this context, the primary objective of the present study is to compare the efficacy ofSPSIPB and PVB in providing postoperative analgesia in patients undergoing thoracicsurgical procedures performed via thoracotomy and to contribute to the optimization ofpostoperative pain management strategies in thoracic surgery.Patients undergoing thoracic surgery via thoracotomy are required to remain in thelateral decubitus position for prolonged periods to facilitate surgical exposure. Thispositioning is considered one of the major contributors to postoperative shoulder pain,primarily due to the mechanical stress imposed on the non‐dependent shoulder andscapulothoracic region. The resulting pain not only compromises patient comfort but mayalso delay early mobilization, thereby adversely affecting respiratory function and therecovery of postoperative pulmonary capacity . Therefore, the ability of regionalanesthesia techniques used in thoracic surgery to provide sensory blockade extendingbeyond the surgical incision site to include dermatomes associated with the shouldergirdle has emerged as an important determinant of analgesic success.Accordingly, the present study aims to comprehensively compare SPSIPB and PVB with regardto both the management of post‐thoracotomy postoperative shoulder pain and their overallanalgesic efficacy. Furthermore, the contribution of these two techniques topostoperative pain management will be thoroughly evaluated in terms of patient comfortand safety profiles.