This exploratory randomized controlled trial evaluated the association of interscalene brachial plexus block (ISB) with early postoperative wound-related symptom scores and perioperative biomarker responses in patients undergoing open rotator cuff repair.

Participants were randomly allocated to receive either ultrasound-guided interscalene brachial plexus block or standardized general anaesthesia. The primary outcome was postoperative wound-related assessment using the Toronto Symptom Assessment System for Wounds (TSAS-W) on postoperative days 5 and 14. TSAS-W was used as an exploratory patient-reported wound symptom assessment tool.

Secondary outcomes included perioperative serum cytokine and growth-factor concentrations (IL-1β, IL-2, TNF-α, EGF, PDGF, and TGF-β), platelet counts, postoperative pain scores, tramadol consumption within 48 hours, time to mobilisation, and postoperative nausea and vomiting.

This study aimed to investigate whether interscalene brachial plexus block was associated with differences in perioperative biological responses and postoperative wound-related symptom scores compared with general anaesthesia.

Study Design and Participants

This prospective, parallel-group randomized controlled trial included adult patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I-II who were scheduled for elective open rotator cuff repair.

Participants were randomly allocated in a 1:1 ratio to receive either ultrasound-guided interscalene brachial plexus block (ISB) or general anaesthesia (GA). Randomization was performed using a computer-generated block randomization sequence with a fixed block size of four. Allocation concealment was achieved using sequentially numbered opaque sealed envelopes prepared by an investigator not otherwise involved in patient care or outcome assessment.

Due to the nature of the intervention, participants and the attending anaesthesiologist were not blinded. The operating surgeon was aware of group allocation because of the visible differences in perioperative anaesthetic management. However, laboratory personnel, postoperative outcome assessors, postoperative care staff, and the statistician remained blinded to group allocation whenever feasible.

A total of 34 participants were randomized. Two participants in the general anaesthesia group were excluded after randomization (one protocol violation and one missing follow-up), leaving 32 participants (GA n=15; ISB n=17) for per-protocol analysis.

Interventions

Patients in the ISB group received ultrasound-guided interscalene brachial plexus block using 20 mL of 0.25% bupivacaine. Surgery in the ISB group was performed under awake regional anaesthesia without routine sedation. Supplemental intravenous fentanyl boluses (25-50 μg) were permitted intraoperatively if clinically required according to predefined haemodynamic criteria.

Patients in the GA group received standardized general anaesthesia with propofol, fentanyl, rocuronium, and sevoflurane.

Outcomes and Data Collection

The primary outcome was early postoperative wound-related assessment using the Toronto Symptom Assessment System for Wounds (TSAS-W) on postoperative days 5 and 14. TSAS-W is a patient-reported wound symptom assessment tool originally developed for chronic wound settings and was used as an exploratory symptom assessment instrument rather than as an objective measure of wound healing.

Secondary outcomes included perioperative serum cytokine and growth-factor concentrations (IL-1β, IL-2, TNF-α, EGF, PDGF, and TGF-β), platelet counts, postoperative pain scores, total postoperative tramadol consumption within 48 hours, time to mobilisation, and postoperative nausea and vomiting.

Blood samples were collected preoperatively and at 24 and 48 hours postoperatively. Laboratory analyses were performed using standardized enzyme-linked immunosorbent assay methods.

Protocol Registration

The study protocol was registered at ClinicalTrials.gov (NCT05499897). Administrative updates to the registry record were made during and after study completion to improve consistency with the final protocol and reported analyses. These updates included clarification of outcome measures, biomarker analyses, sample size reporting, and administrative study dates. No changes were made to the collected data or analyses after study completion.

Inclusion Criteria:

• Adult patients aged 18-65 years
• American Society of Anesthesiologists (ASA) physical status I-II
• Scheduled for elective open repair of a full-thickness rotator cuff tear

Exclusion Criteria:

• Pregnancy or lactation
• Known coagulopathy
• Chronic renal insufficiency
• Chronic hepatic insufficiency
• Significant uncontrolled cardiopulmonary disease
• Chronic opioid use
• Immunosuppressive therapy
• Diabetes mellitus or other uncontrolled metabolic disorders potentially affecting wound healing
• Chronic inflammatory disease
• Morbid obesity (body mass index ≥35 kg/m²)
• Allergy to amide local anaesthetics
• Infection at the injection site
• Emergency surgery
• Inability to complete postoperative assessments

Individual participant data are not planned to be shared because the study involved a small exploratory sample and no formal data-sharing framework was established at the time of study conduct.

Outcome assessors, laboratory personnel, postoperative care staff, and the statistician were blinded to treatment allocation whenever feasible. Due to the nature of the intervention, participants and attending anaesthesiologists were not blinded.