Ultrasound- Guided Retro Superior Costotransverse Ligament (SCTL) Compartment Block

NCT ID: NCT05235815

Last Updated: 2024-04-16

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-05-17
• Study Completion Date: 2024-03-20

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.

Conditions

Thoracic Surgery, Video-Assisted

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Sonoanatomy and retro SCTL compartment block

During phase 1, ten healthy human volunteers will be involved. A bilateral ultrasound scan will be performed in the paravertebral region to describe the sonoanatomy of the retro SCTL compartment.

During phase 2, participants who are scheduled for video-assisted thoracoscopic surgery (VATS) will receive an ultrasound-guided multi-level (T3-4, T5-6 and T7-8) retro SCTL compartment block.

Group Type: EXPERIMENTAL

Retro SCTL compartment block

Intervention Type: PROCEDURE

For phase 1, healthy human volunteers will be positioned in the lateral position with the side to be scanned in the non-dependent position. An ultrasound scan sequence to describe the retro SCTL space will be performed on both sides.

During phase 2, participants who are scheduled for video-assisted thoracoscopic surgery (VATS) will receive an ultrasound-guided multi-level (T3-4, T5-6 and T7-8) retro SCTL compartment block. After positioning the participants, cleaning and draping the injection site, under sterile aseptic precautions and local anaesthetic infiltration, the block needle is inserted at the corresponding vertebral level (T7-T8) under ultrasound guidance in-plane to the ultrasound beam. Once the needle tip reaches the lateral aspect of the inferior articular process and behind the SCTL ligament, the desired volume (6ml/each level) of LA will be injected. This process will be continued at the remaining two vertebral levels (T5-T6 and T3-T4).

Interventions

Retro SCTL compartment block

For phase 1, healthy human volunteers will be positioned in the lateral position with the side to be scanned in the non-dependent position. An ultrasound scan sequence to describe the retro SCTL space will be performed on both sides.

During phase 2, participants who are scheduled for video-assisted thoracoscopic surgery (VATS) will receive an ultrasound-guided multi-level (T3-4, T5-6 and T7-8) retro SCTL compartment block. After positioning the participants, cleaning and draping the injection site, under sterile aseptic precautions and local anaesthetic infiltration, the block needle is inserted at the corresponding vertebral level (T7-T8) under ultrasound guidance in-plane to the ultrasound beam. Once the needle tip reaches the lateral aspect of the inferior articular process and behind the SCTL ligament, the desired volume (6ml/each level) of LA will be injected. This process will be continued at the remaining two vertebral levels (T5-T6 and T3-T4).

Intervention Type: PROCEDURE

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Chinese University of Hong Kong

OTHER

Sponsor Role: lead

Responsible Party

Prof Manoj K Karmakar

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Manoj K Karmakar, MD

Role: PRINCIPAL_INVESTIGATOR

Chinese University of Hong Kong

Locations

Prince of Wales Hospital

Hong Kong, , Hong Kong

Countries

Hong Kong

Other Identifiers

Retro SCTL Block ver3

Identifier Type: -

Identifier Source: org_study_id