EPIDERM Technique: Safety and Outcomes of Skin Grafted Free Flaps in Head and Neck Reconstruction

ABSTRACT

Objectives

While prior studies have demonstrated favorable aesthetic outcomes using skin grafted free flaps to improve recipient site color match (Epithelial Preservation Including Dermal Resection Microvascular technique: EPIDERM technique), the clinical safety of this approach has not been established. Manipulation of the skin paddle potentially impairs free tissue monitoring and therefore may affect success rates. This study aims to compare perioperative outcomes in patients undergoing head and neck free flap reconstruction with and without the EPIDERM technique.

Methods

A retrospective 1:1 matched cohort study was conducted involving 138 patients who underwent free flap reconstruction between January 2022 and December 2024 at a single tertiary care center. Patients were matched by flap type to control for variations in reconstructive technique and defect site. Data collected included demographics, defect characteristics, flap type, operative time, perioperative complications, reoperations, and hospital length of stay.

Results

Defect distribution differed between groups, with scalp defects more common in the EPIDERM group (p = 0.05) and oropharyngeal and mandibular defects more frequent in the standard group (p < 0.01, p = 0.02). Despite these differences in defect distribution, no significant differences were observed in flap viability, wound complications, reoperation rates, hospital readmissions, or length of hospital stay between the color match and non–color match groups.

Conclusion

The EPIDERM technique represents a safe adjunct to head and neck free flap reconstruction, offering the potential for improved aesthetic outcomes with no apparent increase in perioperative risk or morbidity.

Level of Evidence

3.

This study evaluates the safety and outcomes of the EPIDERM technique using skin‐grafted free flaps in head and neck reconstruction. Our findings show that the technique is feasible, reliable, and associated with low complication rates, supporting its usefulness in select reconstructive scenarios.

1. Introduction

Head and neck ablative surgery often results in substantial aesthetic and functional consequences, with postoperative disfigurement posing significant challenges to patient quality of life. Among these, color mismatch between native facial skin and reconstructed tissue is one of the most visually apparent and psychologically distressing issues for patients, particularly when reconstructions involve prominent cutaneous areas of the face [1, 2]. Achieving an optimal color match is important not only for aesthetic restoration but also for improving patient self‐image, social reintegration, and overall satisfaction following oncologic or traumatic reconstruction.

Over the past decade, the accuracy, objectivity, and modifiability of facial skin color matching in reconstructive surgery have been increasingly documented in the literature. Advances in objective colorimetric assessment tools and imaging analysis have enabled surgeons to quantify and compare skin color differences using standardized metrics such as ΔE values, enhancing the ability to assess color match outcomes reliably and guiding refinements in reconstructive strategies [3, 4, 5]. These technologies have provided an evidence‐based framework for selecting donor sites and reconstructive approaches optimized for color harmony. When color‐matched skin paddles are not available or are inappropriate for use, the use of the epithelial preservation including dermal resection microvascular (EPIDERM) technique, using split‐thickness skin grafts (STSG) harvested from the skin paddle placed atop variable thickness of dermis/soft tissue resected free tissue has gained attention as an effective, modifiable technique to improve facial skin color match. Recent studies have demonstrated that the EPIDERM technique achieves effective aesthetic integration compared to reconstructions using free tissue with intact epithelium, as validated by both subjective assessments and quantitative color measurements [2, 6]. As a result, color match techniques like EPIDERM have increasingly been incorporated into reconstructive protocols, with their aesthetic benefits increasingly well established [3, 4].

Despite this growing body of evidence confirming the aesthetic efficacy of EPIDERM, no study to date has systematically evaluated its clinical safety and perioperative outcomes. It remains unclear whether the additional operative steps involved in these techniques, such as flap de‐epithelialization and skin graft application, introduce increased perioperative risks, including prolonged operative time, higher complication rates, wound healing issues, or increased revision procedures. Given the dual priorities of optimizing aesthetic outcomes while ensuring surgical safety in head and neck reconstruction, it is essential to determine whether these color match strategies can be safely incorporated into standard reconstructive practice.

The purpose of this study is to compare the safety and clinical outcomes of patients undergoing head and neck free flap reconstruction with and without the use of the EPIDERM technique. Specifically, this study aims to assess perioperative complication rates, flap viability, wound healing outcomes, and the need for revision procedures in both cohorts. By addressing this gap in the literature, this project seeks to determine whether color match techniques represent a safe and effective adjunct in complex head and neck reconstructive surgery.

2. Methods

2.1. Study Design and Patient Selection

This was a retrospective matched cohort study conducted at a large tertiary care center with Institutional Review Board approval (study #20‐32412). All study participants had undergone head and neck free flap reconstruction between January 2022 and December 2024 and were identified through the institutional surgical database. Patients were divided into two cohorts: those who underwent the EPIDERM technique and those who underwent standard free tissue transfer.

To account for potential variability in perioperative outcomes across different flap types, each patient in the EPIDERM group was matched 1:1 by flap type with a control patient undergoing standard reconstruction. This resulted in a total of 138 patients included for analysis: 69 in the EPIDERM group and 69 in the standard group. Patients were eligible for inclusion if they underwent free flap reconstruction for head and neck defects. Patients were excluded if they were less than 18 years of age, had incomplete operative records, or were missing postoperative follow‐up data.

2.2. Flap Monitoring Protocol

Postoperative flap monitoring was performed using a standardized institutional protocol. All flaps were assessed with handheld Doppler at the anastomotic site, clinical examination for turgor, capillary refill, and, if concerned, bleeding on needle prick. Nursing assessments were performed hourly for the first 72 h, then spaced out gradually over the subsequent days. Intraoral or buried flaps were monitored via externalized skin paddles or implantable Doppler devices when direct visualization was not possible.

2.3. Data Collection and Outcome Measures

Data was extracted from the institution's electronic medical record system. Variables collected included demographics such as age, sex, smoking status, and comorbidities (including diabetes, peripheral vascular disease, and immunosuppression); operative variables including defect location, free flap type, and operative time; and clinical outcomes involving flap viability, wound healing complications, return to the operating room, and length of hospital stay.

The primary outcome was surgical safety, measured by rates of perioperative complications, flap viability, wound healing outcomes, and reoperation rates within 30 days of surgery. Secondary outcomes included length of hospital stay and flap‐specific complications.

2.4. Statistical Analysis

Descriptive statistics were used to summarize patient demographics and perioperative variables. Categorical variables were presented as frequencies and percentages, whereas continuous variables were expressed as means ± standard deviations depending on data distribution. Comparisons between the two cohorts were performed using unpaired t‐tests for continuous variables and chi‐square or Fisher's exact tests for categorical variables, as appropriate. A two‐tailed p‐value < 0.05 was considered statistically significant.

2.5. Power Calculation

Given the relatively low incidence of free flap failure, our study was powered to detect a clinically meaningful difference in overall complication rates. With 138 patients (69 per group), this study was adequately powered (80% at α = 0.05) to detect a minimum absolute difference of 20% in overall complication rates between the EPIDERM and control cohorts.

All analyses were performed using R statistical software (R Studio Team, 2024, PBC, Boston, MA).

2.6. Ethical Considerations

All of the patient data was de‐identified to ensure confidentiality. Given the retrospective nature of the study, informed consent was waived by the IRB.

3. Results

A total of 138 patients underwent head and neck free tissue transfer reconstructive surgery, with 69 (50%) in the EPIDERM group and 69 (50%) in the standard reconstruction group.

3.1. Baseline Demographics and Preoperative Risk Factors

Baseline demographic and clinical characteristics were comparable between the two groups (Table 1). The mean age at surgery was 67.98 ± 10.31 years, with no significant difference between groups (67.2 ± 9.00 years in the EPIDERM group versus 66.76 ± 10.31 years in the standard reconstruction group; p = 0.59).

TABLE 1.

Baseline patient demographics and preoperative risk factors in flap reconstruction cases.

Characteristics	Total value (%)	EPIDERM group (%)	Standard group (%)	p
Patients	138	69 (50)	69 (50)	—
Sex
Male	100	51 (74)	49 (71)	0.84
Female	38	18 (26)	20 (29)	0.74
Age at surgery (years)	67.98 ± 10.31	67.2 ± 9.00	66.76 ± 10.31	0.59
Smoking status
Never	75	43 (62)	32 (46)	0.20
Former	56	24 (35)	32 (46)	0.29
Current	7	2 (3)	5 (7)	0.26
Known pack years
< 10	18	6 (9)	12 (17)	0.17
> 10	26	12 (17)	14 (20)	0.12
Race/ethnicity
White, non‐Hispanic	109	57 (83)	52 (75)	0.63
Black, non‐Hispanic	1	1 (1)	0 (0)	0.32
Hispanic/Latino	12	5 (7)	7 (10)	0.56
Asian	14	6 (9)	8 (12)	0.59
Native Hawaiian or Pacific Islander	1	0 (0)	1 (1)	0.32
American Indian or Alaskan Native	1	0 (0)	1 (1)	0.32
Medical and immunologic risk factors
Radiation history	68	37 (53)	31 (44)	0.47
Immunosuppression	40	20 (29)	20 (29)	1
Diabetes mellitus	22	12 (17)	10 (7)	0.65

The majority of patients were male (74% in EPIDERM vs. 71% in the standard group; p = 0.84) and predominantly White, non‐Hispanic (83% vs. 75%; p = 0.63). Smoking status and cumulative pack‐years were also similar across the two cohorts. A slightly higher proportion of current smokers was observed in the standard reconstruction group (7% vs. 3%; p = 0.26), though this was not statistically significant. The prevalence of medical comorbidities, including prior radiation therapy (53% in EPIDERM vs. 44% in the standard group; p = 0.47), immunosuppression (29% for both cohorts), and diabetes mellitus (17% vs. 7%; p = 0.65), showed no significant differences.

3.2. Operative Characteristics

Operative details and defect characteristics are summarized in Table 2. The majority of reconstructions were for non‐scalp cutaneous defects (35% in the EPIDERM group vs. 20% in the standard reconstruction group; p = 0.10), with scalp, oral cavity, and oropharyngeal defects comprising the large remainder. Notably, there were statistically significant differences in the distribution of scalp, oropharyngeal, and mandibular defects between groups. Scalp defects were more common in the EPIDERM group (30% vs. 14%; p = 0.05). Oropharyngeal defects were exclusively reconstructed in the standard reconstruction group (0% vs. 10%; p < 0.01), whereas mandibular defects were also more frequent in the standard reconstruction group (4% vs. 17%; p = 0.02).

TABLE 2.

Operative characteristics, defect details, and intraoperative complications in flap‐based reconstruction.

Characteristics	EPIDERM group (%)	Standard group (%)	p
n (%)	69 (50)	69 (50)	—
Defect type
Non‐scalp cutaneous	24 (35)	14 (20)	0.10
Scalp	21 (30)	10 (14)	0.05
Oral cavity	8 (12)	17 (25)	0.07
Oropharynx	0 (0)	7 (10)	< 0.01
Mandible	3 (4)	12 (17)	0.02
Maxilla	3 (4)	1 (1)	0.32
Nasal cavity	1 (1)	2 (3)	0.56
Parotid	7 (10)	5 (7)	0.56
Orbit	2 (3)	0 (0)	0.16
Thyroid	0 (0)	1 (1)	0.32
Indication for flap
Tumor	46 (67)	48 (70)	0.83
Fistula	0 (0)	3 (4)	0.08
Wound dehiscence/other	23 (33)	18 (26)	0.43
Flap type
Anterolateral thigh	43 (62)	43 (62)	—
Fibula	10 (14)	10 (14)	—
Latissimus	12 (17)	12 (17)	—
Radial Forearm	4 (6)	4 (6)	—
Average anesthesia time (minutes)	566.01 ± 136.83	559.74 ± 131.47	0.78
Length of hospital stay (days)	6.39 ± 2.98	6.26 ± 2.30	0.78

Note: Bold values indicates statistically significant p values.

The primary indication for flap reconstruction was tumor resection (67% vs. 70%; p = 0.83), followed by wound dehiscence and fistula management. The anterolateral thigh (ALT) flap was the most commonly utilized in both groups (62% each), followed by latissimus, fibula, and radial forearm.

Average anesthesia time was comparable between groups (566.01 ± 136.83 min vs. 559.74 ± 131.47 min; p = 0.78), as was the length of hospital stay (6.39 ± 2.98 days vs. 6.26 ± 2.30 days; p = 0.78).

3.3. Postoperative Outcomes

Postoperative complications and resource utilization are detailed in Table 3. Flap failure rates were low and not significantly different between the groups (3% EPIDERM vs. 4% standard reconstruction group; p = 0.65). The incidence of dehiscence or infection (7% vs. 6%; p = 0.74), hematoma formation (7% vs. 4%; p = 0.48), and seroma (0% in both groups) was comparable.

TABLE 3.

Postoperative complications, surgical outcomes, and resource utilization following flap reconstruction.

Adverse event	EPIDERM group (%)	Standard group (%)	p
Flap failure	2 (3)	3 (4)	0.65
Dehiscence/infection	5 (7)	4 (6)	0.74
Recipient site hematoma	5 (7)	3 (4)	0.48
Seroma	0 (0)	0 (0)	—
OR take back due to complication	5 (7)	6 (9)	0.76
Hospital readmission in 30 days	4 (6)	4 (6)	1

The rate of return to the operating room for postoperative complications was similar between groups (7% EPIDERM vs. 9% standard reconstruction group; p = 0.76). Additionally, hospital readmission within 30 days occurred in 6% of patients in both groups (p = 1.00).

Overall, the use of color match techniques in flap reconstruction was associated with comparable perioperative outcomes relative to the standard reconstruction group. Figure 1 demonstrates the postoperative healing trajectory of a representative patient who underwent the EPIDERM technique, with sequential images highlighting flap integration and skin graft take over time. There were no significant differences in complication rates, flap survival, operative times, hospital stay, or readmission rates.

FIGURE 1.

Postoperative Healing Sequence Following EPIDERM Technique. Representative patient undergoing head and neck free flap reconstruction with the EPIDERM (Epithelial Preservation/Dermal Resection Microvascular) technique. Sequential photographs demonstrate the progression of flap integration and split‐thickness skin graft take at (A) preoperative, (B) intraoperative following dermal resection, (C) 1 week post‐op after bolster removal, and (D) 8 weeks post‐surgery. Images highlight successful graft adherence, color match, and absence of wound complications.

4. Discussion

In this retrospective cohort study comparing patients undergoing head and neck free flap reconstruction with and without the EPIDERM technique, the findings identified no significant differences in perioperative surgical outcomes between two groups. Specifically, rates of flap failure, wound complications (including infection, dehiscence, hematoma, and seroma), reoperation within 30 days, and hospital length of stay were comparable between patients reconstructed with color‐matching skin grafting techniques and those treated with standard free tissue transfer alone. These results suggest that incorporating split‐thickness skin grafts over de‐epithelialized free tissue does not meaningfully increase perioperative morbidity or risk and can be safely integrated into reconstructive protocols.

These findings build on the existing literature which highlights the aesthetic advantages of color match techniques in head and neck reconstruction. Initially described by Knott in 2015 for scalp reconstruction, subsequent work by Knott et al. and Yoshimatsu et al. demonstrated that STSG applied over de‐epithelialized free tissue achieves superior facial skin color blending compared to intact epithelialized flaps, with objective improvements measured via photometric and colorimetric analyses [2, 6, 7, 8]. While these aesthetic benefits have been well documented, our study specifically addresses an unresolved safety concern—namely, whether interference with monitoring protocols inherent to the removal of the dermis and epidermis and coverage of the vascularized tissue with a split thickness skin graft and bolster to improve recipient site color match increases the risk of flap compromise. Prior reports have primarily focused on cosmesis without formal systematic evaluation of safety. By providing the first matched cohort safety analysis of the EPIDERM technique, this study directly responds to that clinical uncertainty.

Notably, we observed no clinically meaningful increase in anesthesia time or reperfusion time associated with the EPIDERM technique, alleviating theoretical concerns that additional procedural complexity could elevate surgical risk [9, 10]. This finding is likely attributable to careful operative planning and the expertise of high‐volume reconstructive teams [11, 12]. Furthermore, it is plausible that STSG may contribute to more reliable wound coverage in cases at risk for dermal congestion or epidermolysis, a hypothesis supported by prior reports describing STSG's benefits in reconstructive settings prone to superficial flap complications [13]. Importantly, even in previously radiated patients (53% of our flap cohort had a history of radiation prior to surgery), the EPIDERM technique remained safe and effective, with no observed increase in flap failure rates, including among immunosuppressed individuals. This is particularly noteworthy given the well‐established challenges associated with wound healing and microvascular reconstruction in radiated fields, where tissue fibrosis, compromised vascularity, and immunosuppression can elevate the risk of complications [9, 10]. Our findings suggest that the EPIDERM technique, by optimizing dermal vascularity and providing reliable superficial coverage with STSG, may mitigate some of these risks, supporting its use in even the most complex reconstructive scenarios. By demonstrating that the inability to visually assess the buried skin paddle did not translate into higher rates of flap failure or delayed recognition of complications, this study provides objective reassurance to a commonly cited surgical concern.

This study offers several notable strengths. It represents, to our knowledge, the first study to explicitly evaluate the safety of the EPIDERM technique in a controlled, matched cohort, rather than assuming safety based on cosmetic outcomes alone. The inclusion of a consecutive patient cohort from a single, high‐volume tertiary care center ensures consistency in surgical technique and postoperative care pathways while minimizing selection and management biases. Additionally, the balanced distribution of patient demographics, defect types, and flap types across groups strengthens the internal validity of our comparisons.

Nevertheless, several limitations should be acknowledged. The retrospective nature of the study introduces risks of information bias and unmeasured confounding, common to observational designs. Although we carefully extracted key demographic, clinical, and operative variables, it is possible that unrecorded factors, such as subtle variations in comorbidities, tumor characteristics, or perioperative management, may have influenced outcomes. Moreover, while the sample size provided adequate power to detect moderate differences in common complications, it may have been underpowered to capture rare adverse events or small outcome differences.

The implications of our findings are meaningful for clinical practice. Given the established psychosocial and aesthetic benefits of achieving superior skin color match in head and neck reconstruction, reconstructive surgeons should consider incorporating color match techniques in appropriate patients, particularly those with visible facial cutaneous defects [8, 14]. By demonstrating that the EPIDERM technique does not compromise flap monitoring or perioperative safety, our work addresses a key barrier to broader adoption and confirms its role as both a cosmetically and clinically sound adjunct, when indicated. Future studies should aim for prospective, multicenter data collection incorporating patient‐reported outcomes and long‐term aesthetic durability to further define the value of these techniques in contemporary reconstructive care. Randomized controlled trials and health economic evaluations would also be valuable in strengthening the evidence base and supporting broader adoption across diverse healthcare settings [15, 16].

5. Conclusion

This study demonstrates that the use of the EPIDERM in head and neck free flap reconstruction is safe and does not increase the risk of perioperative complications when compared to standard reconstructive approaches. While aesthetic advantages of these techniques have been well‐established in the literature, this study's findings provide important new evidence confirming that the addition of split‐thickness skin grafts over de‐epithelialized free tissue does not compromise flap viability, wound healing, or overall patient safety. Given the potential psychosocial and aesthetic benefits of achieving a superior skin color match, these techniques should be considered a viable adjunct in reconstructive practice. Future research should focus on prospective, patient‐centered outcomes and long‐term aesthetic analyses to further define the value and durability of color match strategies in head and neck reconstruction.

Disclosure

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Patel N., Reynoso N., Heaton C., et al., “ EPIDERM Technique: Safety and Outcomes of Skin Grafted Free Flaps in Head and Neck Reconstruction,” The Laryngoscope 136, no. 4 (2026): 1727–1733, 10.1002/lary.70261.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.