Clinical trial NCT05235815: Ultrasound- Guided Retro Superior Costotransverse Ligament (SCTL) Compartment Block
Official title: Ultrasound-Guided Retro Superior Costotransverse Ligament (SCTL) Compartment Block: Description of Sonoanatomy, Technique and Block Dynamics
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Thoracic Surgery, Video-Assisted
Keywords: Superior costotransverse ligament
Video assisted thoracoscopic surgery
Thoracic paravertebral block
Retro superior costotransverse ligament compartment
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
First posted: 2022-02-11
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: Thoracic paravertebral block (TPVB) is a regional anaesthetic technique that produces ipsilateral, segmental, somatic and sympathetic nerve blockade of multiple contiguous thoracic dermatomes. Although it is a safe technique, the needle tip comes close to the pleura during the injection, therefore, increasing the potential for pleural puncture and pneumothorax, especially when performed by inexperienced physicians. With the recently described retro superior costotransverse ligament (SCTL) compartment (using MRI) which has been shown to be in direct continuity with the intervertebral foramen, the investigators propose that the block needle need not pierce the SCTL and lie close to the pleura but can be positioned safely behind the ligament to deposit the local anaesthetic (LA). Therefore, this study aims to describe the sonoanatomy of the retro SCTL compartment and evaluate the block injection technique and sensory dynamics in patients scheduled for video-assisted thoracoscopic surgery (VATS).

Detailed description: During a TPVB the LA is injected into the paravertebral space adjacent to the thoracic vertebra and close to the intervertebral foramen. Traditionally, either landmark or ultrasound-guided, TPVB is performed by depositing the LA anterior to the superior costotransverse ligament (SCTL), i.e. the block needle typically pierces the SCTL to reach the wedge-shaped TPVB space. Although it is a safe technique, the needle tip comes close to the pleura during the injection, therefore, increasing the potential for pleural puncture and pneumothorax, especially when performed by inexperienced physicians.

Recently, with the help of 3D micro computer tomography (CT), Cho T and colleagues have demonstrated in cadavers that the medial part of the SCTL does not end at the base of the transverse process but extends anteriorly to the vertebral body dividing the wedge-shaped paravertebral space into a retro SCTL compartment (posterior to SCTL) and a true paravertebral space (anterior to SCTL). Also, they demonstrated that the SCTL, as it extends to the vertebral body, forms a medial slit near the intervertebral foramen through which the ventral rami enters the true paravertebral space. Furthermore, they highlighted that the retro SCTL space or compartment is in direct communication with the intervertebral foramen and epidural space medially and to the true paravertebral space (through the medial and lateral slits). It is evident from their study that the retro SCTL compartment contains both the divisions of the spinal nerve, i.e., the ventral and dorsal rami, the latter exits the compartment to enter the erector spinae plane. Hence, with this new concept, it appears that the block needle tip needs not to pierce the SCTL as required in a conventional TPVB and LA deposited at the retro SCTL compartment, theoretically can spread to the paravertebral space, intervertebral foramen and the epidural space, to block the spinal nerves and its divisions, and the sympathetic trunks. The investigators believe that the LA injection in the retro SCTL compartment, owing to its close relationship with the intervertebral foramen, thoracic spinal nerve, and the sympathetic trunks, will also produce rapid onset of ipsilateral and or bilateral segmental somatic and sympathetic blockade of the thoracic dermatomes, akin to TPVB. In addition, as the needle tip lies farther away from the pleura (posterior to SCTL) the investigators believe that this technique may also be safer in terms of the potential risk of pleural puncture or pneumothorax than a conventional TPVB.

Eligibility criteria: Inclusion Criteria:

* Phase 1: Healthy volunteers of age 18-60 years
* Phase 2: Patients age 18-80 years scheduled for video assisted thoracoscopic surgery (VATS)

Exclusion Criteria:

* Phase 2: 1. Patient refusal 2. Local skin site infection 3. Coagulopathy 4. History of allergy to local anesthetics

Primary outcomes:
measure: Ultrasound visualization of the retro SCTL compartment in volunteers
timeFrame: Within 30 minutes after entering the procedure room
measure: Readiness for surgery
timeFrame: Within 30 minutes after the block at 5 minutes interval
Secondary outcomes:
measure: Complete sensory block
timeFrame: Within 30 minutes after the block at 5 minutes interval
measure: Block performance time
timeFrame: Within 30 minutes after entering the procedure room
measure: Total amount of vasopressor used
timeFrame: After completion of the block and through the surgical period, an average of 6 hours
measure: Total amount of morphine used
timeFrame: During surgical period and postanesthesia care unit (PACU) period, an average of 6 hours
measure: Postoperative pain score
timeFrame: At arrival and discharge from postanesthesia care unit (PACU)
measure: Postoperative sensory score before discharge
timeFrame: At discharge from postanesthesia care unit (PACU)
measure: Complications
timeFrame: Within 45 minutes after the block, within 24 hours post surgery and at 1 week after the surgery
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Prince of Wales Hospital
Study officials:
affiliation: Chinese University of Hong Kong
name: Manoj K Karmakar, MD
role: PRINCIPAL_INVESTIGATOR
References: