This paper presents a protocol for a single-centre, prospective, randomised, open-label, blinded-endpoint controlled trial to evaluate whether continuous parasacral ischial plane block (CPIPB) combined with standard of care improves complete ulcer healing at 12 weeks compared to standard of care alone in patients with diabetic foot ulcers.
Key Findings
Methods
The trial uses a PROBE (prospective, randomised, open-label, blinded-endpoint) parallel-group design to evaluate CPIPB combined with standard of care versus standard of care alone for diabetic foot ulcer healing.
Single-centre study registered at chictr.org.cn with identifier ChiCTR2400083504
Participants are randomised 1:1 using variable block randomisation
The open-label design is used because blinding the intervention (catheter placement) is not feasible, while endpoints are assessed by blinded evaluators
The trial includes a 2-week standard of care run-in period before randomisation, with inclusion requiring less than 30% wound area reduction during this period
Methods
A total of 78 participants aged 20–89 years will be recruited, with diabetic foot ulcers classified as University of Texas Classification 1A–2D present for more than 4 weeks but less than 1 year.
Ulcer area must be between 1–20 cm²
Adequate perfusion is required, defined as ankle-brachial index (ABI) greater than 0.7 or equivalent
Participants must have less than 30% wound area reduction during the 2-week run-in period to qualify for randomisation
Age range is 20–89 years
Methods
The CPIPB intervention involves ultrasound-guided catheter placement in the parasacral ischial plane for continuous infusion of 0.2% ropivacaine at 5 mL/h for 14 days.
CPIPB targets the sacral plexus as a regional anaesthesia technique
The infusion is administered for a duration of 14 days
The concentration of ropivacaine used is 0.2% at a rate of 5 mL/h
The technique has shown potential in preclinical studies and feasibility assessments to improve lower limb analgesia and perfusion by modulating sympathetic tone
Methods
The primary outcome is the incidence of complete ulcer healing at 12 weeks.
Statistical analysis will primarily use the intention-to-treat principle
Group comparisons will use chi-square tests, t-tests or Mann-Whitney U tests, Kaplan-Meier analysis, and logistic/linear regression models adjusting for baseline covariates
The 12-week endpoint was chosen to capture healing outcomes following 14 days of CPIPB treatment
Methods
Secondary outcomes include multiple measures of wound healing, perfusion, pain, quality of life, and safety.
Secondary outcomes include time to complete healing and percentage change in ulcer area
Proportion of participants achieving ≥50% area reduction, ulcer recurrence, and infection rates are also assessed
Pain will be measured using the Visual Analogue Scale (VAS)
Lower limb perfusion will be assessed using transcutaneous oxygen pressure (TcPO2) and Peak Systolic Velocity
Health-related quality of life will be measured using the Wound-QoL instrument
Background
The investigators hypothesize that CPIPB combined with standard of care will significantly improve ulcer healing compared to standard of care alone without provoking significant adverse reactions.
The hypothesis is based on preclinical studies and feasibility assessments suggesting CPIPB improves lower limb analgesia and perfusion by modulating sympathetic tone
Standard of care includes glycaemic control, appropriate debridement, and standard dressings
The authors state these findings 'potentially pave the way for a safe and effective adjunctive therapy for DFU'
What This Means
This research describes the protocol for a clinical trial testing a nerve block technique called continuous parasacral ischial plane block (CPIPB) as a potential treatment to help heal diabetic foot ulcers (DFUs). DFUs are open wounds on the feet of people with diabetes that are difficult to heal and significantly increase the risk of amputation. The trial will enroll 78 patients who have had a foot ulcer for at least 4 weeks that has not responded well to standard care, and will randomly assign them to receive either standard care alone or standard care plus a continuous infusion of a local anesthetic (ropivacaine) delivered near the sacral nerves in the lower back for 14 days. The main question the trial seeks to answer is whether more patients in the CPIPB group have completely healed ulcers after 12 weeks.
The rationale for this approach is that the nerve block may reduce pain and also improve blood flow to the foot by calming down the sympathetic nervous system, which controls blood vessel constriction. Better blood flow and reduced pain could create conditions more favorable for wound healing. The trial also measures secondary outcomes including how quickly wounds heal, how much the wound area shrinks, infection rates, blood flow in the leg, and patients' quality of life.
This research suggests that regional nerve blocks, typically used for pain management, may have broader benefits for wound healing in diabetic patients by improving circulation in the affected limb. If the trial confirms the hypothesis, CPIPB could represent a new add-on treatment option for the many patients whose diabetic foot ulcers do not heal adequately with current standard approaches. However, as this is a study protocol, the actual results are not yet available.
Ye P, Pan X, Huang Y, Zhuang J, Fan H, Lin Y, et al.. (2026). Ultrasound-guided continuous parasacral ischial plane block for diabetic foot ulcer healing: study protocol for a single-centre, prospective, randomised, open-label, blinded-endpoint controlled trial.. Frontiers in endocrinology. https://doi.org/10.3389/fendo.2026.1884667