Clinical trial NCT05045300: Paraneural Sheath & Fascial Compartments Surround Brachial Plexus at Supraclavicular Fossa During Selective Trunk Block
Official title: Paraneural Sheath and Fascial Compartments Surrounding the Brachial Plexus at the Supraclavicular Fossa: A Retrospective Review of High Definition Ultrasound Images Acquired During Selective Trunk Brachial Plexus Blockade
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Musculoskeletal Diseases or Conditions
Keywords: Selective Trunk block
Lead sponsor: Chinese University of Hong Kong
Sponsor class: OTHER
First posted: 2021-09-16
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Dataset of previous research titled "Selective Trunk Block: A Prospective Non-Randomized Study of Intervention" (approved by the Joint CUHK-NTEC CREC; CREC Ref no: 2020.687-T; Clinical trial registration: NCT04752410) and " Minimum Effective Local Anaesthetic Volume of a 1:1 Mixture of 2% Lidocaine with 5 µg/ml of Epinephrine and 0.5% Levobupivacaine Required for Ultrasound Guided Selective Trunk Block: A Dose Finding Study" (approved by the Joint CUHK-NTEC CREC; CREC Ref no:2020.680-T; Clinical trial registration: NCT04773405) will also be retrieved.

Brief summary: The aim of this retrospective study is to define the paraneural (fascial) sheath and fascial compartments that surround the brachial plexus at the supraclavicular fossa by reviewing previous ultrasound images from cases that have undergone ultrasound guided selective trunk brachial plexus block.

Detailed description: The optimal anatomical plane (relative to the nerve) or the "goal" for local anesthetic (LA) injection during an ultrasound guided (USG) brachial plexus blockade (BPB) at the supraclavicular fossa is currently not known. USG BPB is often described as a "subfascial", "extra fascial", "intracluster", "interfascial", sub-perineural", "intraneural", "corner pocket" or "periplexus" injection. Although this suggests that the local anesthetic is injected into different tissue planes or fascial compartments, even if such planes do exist, as seen in other regions such as popliteal sciatic nerve are not clearly defined at the supraclavicular fossa. However, recently with the use of high definition ultrasound imaging for USG Selective trunk block (SeTB) and principal investigator has often observed distinct paraneural (fascial) sheath and fascial compartments surrounding the brachial plexus at the supraclavicular fossa. These connective tissue layers are also better delineated after the local anesthetic injection. The principal investigator believes these may be the connective tissue layers that previous researchers have referred to in different reports. Currently there are no published data demonstrating the paraneural sheath and fascial compartment surrounding the brachial plexus in-vivo. Principal investigator believes that this fascial layer and compartment influence the spread of LA during USG BPB around the individual elements of the brachial plexus at the supraclavicular fossa and therefore, these anatomical structures have to be delineated so as to improve the safety, success and quality of USG BPB. This study will involve reviewing archived high definition ultrasound images in audio video interleave format from all adult patients who had undergone USG SeTB for surgical anesthesia during upper extremity surgery from January 1, 2020 to June 30, 2021 to define the paraneural sheath and fascial compartments that surround the brachial plexus at the supraclavicular fossa.

Eligibility criteria: Inclusion Criteria:

* Archived high definition ultrasound images (datasets) in audio video interleave (AVI) format from all adult patients who had undergone ultrasound guided selective trunk block for surgical anesthesia during upper extremity surgery since the year 2020 (from 01/01/2020 to 30/06/2021).

Exclusion Criteria:

* patients \> 75 years old
* American Society of Anesthesiologists (ASA) physical status \> Ⅲ
* previous history of surgery at ipsilateral neck.

Primary outcomes:
measure: Visualization of anatomical nerve structures
timeFrame: through study completion, an average of 1 month
Secondary outcomes:
measure: Visualization of the presence of anatomical variations
timeFrame: through study completion, an average of 1 month
measure: Presence of artery within the nerve cluster
timeFrame: through study completion, an average of 1 month
Other outcomes:
Locations:
city: Shatin
country: Hong Kong
facility: Department of Anaesthesia & Intensive Care, Prince of Wales Hospital
state: New Territories
Study officials:
affiliation: Chinese University of Hong Kong
name: Manoj K Karmakar, MD
role: PRINCIPAL_INVESTIGATOR
References: