Clinical Study on Early Conservative Tangential Excision Combined with Xenogeneic Dermal Grafting for the Treatment of Extensive Critical Burns

Technical Summary: Early Conservative Tangential Excision Combined with Xenogeneic Dermal Grafting for Extensive Critical Burns

Problem Statement
Patients with extensive critical burns (Total Body Surface Area [TBSA] >50%) face high mortality rates, primarily driven by systemic complications such as Multiple Organ Dysfunction Syndrome (MODS), sepsis, and Systemic Inflammatory Response Syndrome (SIRS). A central clinical dilemma exists regarding the timing of surgical intervention: while early escharectomy (within 48–72 hours) is recommended to remove necrotic tissue and reduce inflammatory mediator release, performing surgery during the early shock phase (within 24 hours) carries significant risks. Conventional escharectomy often results in substantial intraoperative blood loss (approx. 0.8–1.0 mL/cm²), necessitating large-volume transfusions that can exacerbate hemodynamic instability. Conversely, delayed surgery allows for hemodynamic stabilization but permits the sustained absorption of burn toxins and inflammatory mediators, increasing susceptibility to SIRS and MODS. There is currently no unified standard for the optimal timing, method, or extent of surgery for these critical patients.

Methodology
This study presents a retrospective analysis of 22 patients with extensive burns (TBSA 50%–90%, mean 65.4%) admitted to the Burn Department of Gansu Provincial Hospital between December 2019 and June 2025. All patients underwent a specific intervention protocol:

• Timing: Surgery was performed within the early shock phase, specifically 12 to 24 hours post-burn, once hemodynamic stability (Mean Arterial Pressure >65 mmHg, urine output >0.5 mL/kg/h) was achieved.
• Surgical Technique: A "conservative tangential excision" was utilized. Unlike conventional methods that remove tissue down to healthy fascia, this technique preserved viable intermediate-zone tissue and partial reticular dermis. Debridement was halted when minimal oozing hemorrhage (for deep partial-thickness) or scattered punctate bleeding points (for full-thickness) were observed. Circumferential burns were decompressed, but no debridement was performed on the head, neck, perineum, or toes.
• Grafting: Immediately following excision, wounds were covered with xenogeneic dermis (acellular dermal matrix, 0.3–0.5 mm thickness).
• Resuscitation: Fluid resuscitation followed the Third Military Medical University formula but was dynamically adjusted based on urine output and hemodynamic parameters.
• Data Collection: The study monitored hemodynamic stability (hemoglobin, B-type Natriuretic Peptide [BNP], blood lactate), inflammatory markers (TNF-α, IL-6, IL-10, Procalcitonin [PCT], WBC), and clinical outcomes (wound healing rate, infection rates, number of surgeries, length of stay).

Key Results
The study reported the following outcomes for the 22 patients:

• Hemodynamic Stability: Despite surgery during the shock phase, hemoglobin levels remained stable, with postoperative levels averaging 156.43 ± 25.60 g/L. Notably, no intraoperative blood transfusions were required.
• Fluid Resuscitation: Actual fluid volumes administered were significantly lower than formula-calculated estimates. At 24 hours, actual infusion was 5,195.95 ± 1,758.06 mL compared to a formula estimate of 8,735.36 ± 2,729.43 mL (P < 0.05). At 48 hours, actual infusion was 9,279.52 ± 2,698.76 mL versus 14,103.04 ± 4,094.14 mL (P < 0.05).
• Metabolic and Cardiac Markers: Blood lactate levels decreased significantly to 2.70 ± 0.95 mmol/L by the first postoperative day. BNP levels showed a transient increase, peaking on day 6 (571.8 pg/mL) before declining, consistent with the post-burn resorptive phase, with no evidence of cardiac dysfunction.
• Inflammatory Response: Procalcitonin (PCT) peaked on postoperative day 1 and subsequently declined. IL-6 levels peaked on day 3 before decreasing. IL-10 showed a downward trend. TNF-α fluctuated within the normal range.
• Clinical Outcomes:
  • Infection: The wound infection rate was 9.1% (2 cases), with no instances of systemic sepsis, MODS, or mortality.
  • Healing: Spontaneous wound healing reached 44.5 ± 22.15% by three weeks postoperatively.
  • Efficiency: The average number of surgical interventions per patient was 3.35 ± 1.81, and the average hospital stay was 53.9 ± 26.7 days.

Key Contributions
The paper proposes a strategy that balances the benefits of early debridement with the risks of shock-phase surgery. By combining conservative tangential excision (which preserves viable tissue and minimizes blood loss) with xenogeneic dermal grafting (which acts as a biological barrier against bacterial colonization and fluid loss), the study demonstrates that:

1. Early surgery (12–24 hours) can be performed without exacerbating hemodynamic instability or requiring massive transfusions.
2. The approach effectively reduces the systemic inflammatory response and metabolic disturbances associated with extensive burns.
3. The use of xenogeneic dermis facilitates spontaneous healing of a significant portion of the wound, reducing the need for subsequent autologous skin grafting.

Significance and Claims
The authors claim that this combined strategy represents a safe and effective early intervention protocol for extensive critical burns. The study suggests that this approach effectively maintains hemodynamic stability, significantly reduces systemic inflammatory responses, lowers infection incidence, decreases the total number of required surgeries, and shortens hospital stays compared to current international averages.

The paper acknowledges its limitations, noting the small sample size (n=22), the retrospective nature of the study, and the lack of a randomized controlled design or multicenter investigation. Consequently, the authors present these findings as a novel theoretical and practical insight for early severe burn management, rather than a definitive standard of care, calling for further validation.