Management of Stalled Post-Surgical Diabetic Foot Wounds
Discontinue VAC Therapy Immediately
You should stop the VAC therapy now—the IWGDF guidelines strongly recommend against using NPWT for non-surgical diabetic foot ulcers, and your patient's wounds have transitioned from post-surgical to chronic non-healing ulcers after 6 weeks. 1, 2 The dry, crusty, avascular coating indicates the wounds have stalled and are no longer responding to negative pressure therapy. 1
The evidence shows NPWT only benefits fresh post-surgical wounds with healthy debrided tissue and controlled drainage 2, which your patient no longer has. After 5 weeks of VAC therapy with no progress for 3 weeks, continuing NPWT risks wound maceration, dressing retention, and paradoxically, infection. 1
Immediate Wound Management Protocol
Sharp Surgical Debridement (Priority #1)
Perform aggressive sharp debridement with a scalpel to completely remove the dry, crusty, proteinaceous coating and all surrounding callus from both wounds. 3, 1 This is the single most critical intervention—the avascular coating is preventing healing and must be removed. 3
Debride weekly or more frequently as needed until healthy granulation tissue appears. 3, 4 Sharp debridement is the most effective, least expensive, and universally available method. 3
However, first verify adequate perfusion: Check ankle-brachial index (ABI) and ankle pressure immediately. If ankle pressure is <50 mmHg or ABI <0.5, obtain urgent vascular imaging before aggressive debridement. 4, 1 Severe ischemia is a contraindication to aggressive debridement. 3
Post-Debridement Dressing Selection
After debridement, apply calcium alginate dressings (Kaltostat, Algicell, or Aquacel) to the wound beds if there is any exudate, or foam dressings (Mepilex, Allevyn, or PolyMem) if the wounds remain dry. 4 Change dressings daily initially, then adjust frequency based on exudate levels.
Use simple, moisture-retentive dressings—the goal is maintaining a moist wound environment without the complexity of VAC. 1, 3
Do not use antimicrobial dressings routinely unless signs of infection develop. 3
Adjunctive Therapies: Specific Recommendations
Becaplermin Gel (Regranex)
Apply becaplermin gel 0.01% (Regranex) once daily to both wounds after debridement. 5 This is FDA-approved specifically for diabetic lower extremity neuropathic ulcers extending into subcutaneous tissue. 5
- Calculate the dose based on wound size: measure wound length × width in centimeters, then apply the calculated amount from a 15g tube. 5
- Apply once daily, cover with saline-moistened gauze, then after 12 hours rinse off and apply fresh saline dressing. 5
- Continue until complete healing or 20 weeks maximum. 5
- Important caveat: Becaplermin requires adequate blood supply (TcPO2 >30 mmHg) to work. 5
Hyperbaric Oxygen Therapy (HBO)
Consider adding hyperbaric oxygen therapy (30-40 sessions at 2.0-2.5 ATA for 90 minutes) if wounds show <30% size reduction after 4 weeks of optimal standard care. 1 The IWGDF 2020 guidelines show HBO can improve healing in chronic diabetic foot ulcers when standard care fails, though evidence quality is moderate. 1
- HBO is particularly beneficial if there is any component of ischemia (ankle pressure 50-70 mmHg). 1
- Contraindications include untreated pneumothorax and certain chemotherapy agents. 1
Platelet-Rich Plasma (PRP) and Growth Factors
Do not use platelet-rich plasma or other platelet-derived products at this time. 1 The IWGDF guidelines only suggest considering placental-derived products (not PRP) after standard care has definitively failed, which hasn't been established yet since you haven't optimized standard care. 1
Topical Oxygen Therapy
Do not use topical oxygen therapy—two large blinded RCTs showed conflicting results, with one showing benefit and one showing no benefit. 1 Given the conflicting evidence and cost, this is not recommended. 1
Weight-Bearing Status and Offloading
Strict Non-Weight-Bearing Protocol
The patient must be completely non-weight-bearing on the affected foot until both wounds heal. 3, 4 Given the lateral ankle and plantar locations with recent hardware placement, any weight-bearing will prevent healing.
- Provide a knee scooter or wheelchair for mobility. 4
- If the patient must ambulate, use crutches with strict instructions for zero weight on the affected limb. 4
Protective Footwear When Healed
Once wounds close, transition to custom therapeutic footwear with custom molded insoles (Plastazote or similar) to prevent recurrence. 1 This is critical for dialysis patients with diabetes who have extremely high recurrence risk.
Bed Rest Positioning
Use a heel suspension boot (Prevalon or similar) or pillows under the calf to keep the heel completely off the bed surface during rest. 4 The plantar wound must have zero pressure even when lying down.
Infection Surveillance and Management
Weekly Assessment Protocol
Even without current signs of gross infection, assess both wounds weekly for purulent discharge, erythema extending >2cm from wound edges, warmth, or new tenderness. 3, 4
If Infection Develops
For mild infection: Start oral antibiotics targeting S. aureus and streptococci—cephalexin 500mg four times daily or clindamycin 300mg three times daily (adjust for dialysis schedule). 4, 3
For moderate/severe infection: Urgent surgical debridement and IV broad-spectrum antibiotics. 3, 4
Obtain wound cultures from the debrided base (not swabs) to guide antibiotic adjustment. 4
Dialysis-Specific Considerations
Timing of Interventions
Schedule wound care appointments on non-dialysis days when possible to maximize patient energy and compliance. 1
Coordinate antibiotic dosing with dialysis schedule—many antibiotics require post-dialysis supplementation. 4
Nutritional Optimization
Despite dialysis restrictions, ensure adequate protein intake (1.2 g/kg/day) to support wound healing. 1 Consider renal-specific nutritional supplements if dietary intake is inadequate.
Follow-Up Schedule and Monitoring
Week 1-4: Debride and assess wounds twice weekly, measure and photograph wound dimensions at each visit. 3
Week 4: If wounds show <30% size reduction, add HBO therapy. 1
Week 8-10: If still <30% reduction despite HBO and becaplermin, consider placental-derived products (EpiFix, Grafix, or similar). 1
Week 20: If not healed by 20 weeks despite all interventions, reassess vascular status and consider surgical options including flap coverage. 5
Critical Pitfalls to Avoid
Never continue VAC therapy on dry, non-progressing wounds—this is futile and expensive. 1, 2
Never skip vascular assessment—ischemia will prevent healing regardless of other interventions. 4, 1
Never allow weight-bearing on these wounds—mechanical stress will prevent closure. 3, 4
Never soak the foot in footbaths—this causes maceration and worsens healing. 3