Abstract
The loss of skin envelope is a frequent and costly problem in health care. This article provides an overview on the state of the art in scalp reconstruction with dermal substitutes, as well as our personal experience of ten critical patients with non-melanoma skin cancer of the scalp. These patients were treated in a two-stage procedure by wide tumor excision, apposition of a dermal induction template (Hyalomatrix®) and successive skin grafting. Four patients underwent subgaleal tumor excision with preservation of the periosteum and six patients en bloc tumor excision together with the external cortical bone. A 10×10 cm template was used in all patients. Two weeks after demolition surgery, we observed neodermis formation. Results were documented by comparative photography, visual analogue scale for patient satisfaction, and Vancouver scar scale for evaluation of final graft characteristics. Patients were tumor-free during follow-up. The procedure achieved good scalp reshaping and graft scarring evolution. Patient satisfaction was high. Hyalomatrix® was effective for oncological scalp reconstruction in critical patients. It prepared the wound bed for graft take while awaiting histological diagnosis and confirmation of margin clearance. Further studies on dermal substitutes are needed to improve benefit in patients.
The loss of skin envelope is one of the oldest, yet most frequent and costly problems in our health care system. To restore functional and aesthetic integrity in patients with unstable or hypertrophic scars, in patients with burn and after skin loss for hereditary, traumatic or oncological reasons, an armamentarium of reconstructive surgical procedures, including autogenous, allogenous and xenogenous tissue transfer, as well as implantation of alloplastic materials, has been favored. For several decades, there has been increasing interest focused on tissue engineering of dermal, epidermal and full-thickness skin substitutes using both biological and synthetic matrices (1).
At our Institution, a bioresorbable dermal substitute, called Hyalomatrix® (Fidia Advanced Biopolymers, Abano Terme, Italy), has been used for immediate dermal coverage after excision of infiltrating giant non-melanoma skin cancer (NMSC) of the scalp. This article provides an overview of the current state of the art in scalp reconstruction with bioartificial skin; also, we present our experience regarding the use of Hyalomatrix® template for dermal replacement after wide oncological demolition in critical patients.
Materials and Methods
Patients affected by infiltrating giant (more than 4 cm) NMSC of the scalp, American Association of Anesthesiologists (ASA) class III, were included in this prospective clinical study. At clinical examination, the mobility of the lesion on deep layers was assessed. If the tumor was fixed to the calvarium, the patients underwent instrumental examination with computerized tomography of the scalp to assess bone infiltration.
Patients were treated by wide tumor excision. Surgical skin margins from 5 to 15 mm were selected in relation to the dimension and suspected histotype of the lesion according to the scientific evidence for NMSC excision (2). We planned a maximum skin margin excision (15 mm) in cases of relapsing neoplasm or a lesion fixed to deep layers.
Under loop magnification, when the lesion did not extended beyond the galea, the surgical excision was performed in the subgaleal plan. In cases of deeper tumor extension and suspicion of external cortical bone involvement, the external calvarium was removed en bloc together with the lesion.
More advanced tumors infiltrating the diploic bone required a full-thickness calvarium demolition, requiring different reconstructive procedures, and patients with such tumors were not included in this study.
Clinical views of case 10 of Table I. Left: Preoperative aspect of a basal cell carcinoma of the scalp not infiltrating the galea. Right: Postoperative aspect 2.5 years after partial-thickness skin grafting.
Case study, reporting demographic patient profiles, tumor histotype, time interval between dermal template apposition and skin grafting, and occurrence of complications.
In enrolled patients, during the same surgical procedure, the defect was covered by applying the Hyalomatrix® dermal induction template directly to the periosteum or the diploic bone.
Product characteristics. Hyalomatrix® is a bilayer of an esterified hyaluronan scaffold beneath a silicone membrane. The scaffold delivers hyaluronan to the wound bed, and the silicone membrane acts as a temporary epidermal barrier. This bioresorbable dermal substitute is made of HYAFF 11® (Fidia Advanced Biopolymers), a long-acting derivative of hyaluronic acid providing a microenvironment suitable for optimal tissue repair and accelerated wound healing. Hyaluronic acid is one of the main polysaccharides of the extracellular matrix and has an important role in the healing of wounds in general, and of the skin in particular. Hyalomatrix® is specifically intended for the treatment of deep burns and full-thickness wounds, providing wound preparation to support the implantation of skin grafts (3). It has also been successfully used in the treatment of extravasation injury (4).
In Italy, the cost of a 10×10 cm template of the product is 226.67 €; the cost of a 10×20 cm template is 410.42 €.
Technique of placement. Hyalomatrix® is placed in contact with the wound bed, such that the translucent silicone membrane is at the top and external. A compressive dressing is then required as in skin graft immobilization by using either a polyurethane sponge or sterile gauzes.
The removed lesion specimen and multiple biopsies of the lateral and deep margins of the created defect were sent for histological examination. Patients were discharged on the same day or the day after surgery and monitored on an outpatient basis.
The clinical dressing was examined every 3-5 days, until the first dressing change was performed two weeks after surgery. During this dressing change, the compressive dressing was removed, together with the external layer of the template, and the integration of the deep layer was checked.
The wound margins were disinfected with iodine solution and the wound was covered with a non-adherent dressing based on 0.2% hyaluronic acid (Connettivina; Fidia Farmaceutici, Abano Terme, Italy). Successive dressing changes were performed every 3-5 days until the final histological examination was obtained.
Once the histological diagnosis was obtained and clearance of the margins was confirmed, final wound coverage was performed with partial-thickness skin autograft.
Clinical and instrumental views of case 1 from Table I. Above left: Preoperative aspect of a relapsing infiltrating basal cell carcinoma of the scalp with suspicious external cortical bone involvement. Above right: Preoperative computerized tomography image of the scalp showing initial external cortical bone tumor infiltration. Below left: Postoperative complete wound coverage with granulation tissue two weeks after the application of Hyalomatrix® on the diploic bone after tumor resection. Below right: Postoperative aspect 1.5 years after partial-thickness skin grafting.
Intraoperative views during demolitive surgery of case 1 from Table I. Above left: Wide tumor excision with 15 mm of surgical skin margins. Above right: Resection of the external cortical bone. Below left: Measure of the defect before round block suture with Gore-Tex CV-0 (W.L. Gore & Associates, Flagstaff, AZ, USA) used to reduce defect dimension. Below right: Defect covered with a 10×10 cm Hyalomatrix® template.
Follow-up was scheduled at 1, 3, 6 and 12 months and then planned every 6 months for up to 5 years.
Results were documented during follow-up by taking digital photographs and by assessing patient satisfaction with a visual analogue scale (VAS), scoring from 0 to 10 (poor to excellent result) and final graft characteristics with the Vancouver scar scale (VSS) for evaluation of vascularity, pigmentation, pliability and height/thickness of the graft (5).
Results
Between 2009 and 2011, 10 patients with ASA III disease (7 males, 3 females) were enrolled in the study (Table I). Their age ranged from 60 to 90 years (average=74.4 years). These patients underwent oncological surgery of the scalp. Scalp defect sizes ranged from 4.5×5 cm to 10×10 cm; four patients underwent subgaleal excision with preservation of the periosteum (Figure 1) and six patients underwent en bloc excision of tumor together with the external cortical bone (Figures 2 and 3).
All patients required a single 10×10 cm template of Hyalomatrix® to cover the defect (Figure 3). Surgery was performed with success in every patient, lasting 30 to 70 min (average=40 min). In all cases, product handling was simple. All patients were discharged on the same day or the day after surgery.
At the first dressing change, two weeks after surgery, partial integration of the template was apparent with formation of neodermis and granulation tissue (Figure 2). The matrix of hyaluronic acid provided a microenvironment suitable for optimal tissue repair and excellent wound preparation to support the implantation of autologous skin grafts, performed after final histology that confirmed margin clearance in all cases. Final diagnosis was basal cell carcinoma (BCC) in eight cases and squamous cell carcinoma (SCC) in two cases. Skin grafting was performed 14 to 21 days (average=18 days) after demolition surgery. Skin graft take was between 80 and 100% (Table I). Complete wound healing was achieved 25 to 35 days (average=30 days) after first surgery.
The procedure resulted in good reshaping (Figure 1 and 2). No complications related to surgery were observed, with the exception of one case of infection (Table I).
Patient satisfaction was high, with an average VAS score of 8.5.
The VSS highlighted good graft evolution, with normal vascularity in all cases, normal pigmentation in nine cases, hypopigmentation in one case, and no hyperpigmentation; the pliability was normal, supple or yielding in all cases; the graft height was flat or less than 2 mm.
Patients were tumor-free during follow-up (minimum 1 year, maximum 2.5 years).
Discussion
Scalp reconstruction has always been a challenging task, in particular after oncological demolition.
In this type of surgery, firstly, oncological radicality should be pursued, especially for large infiltrating tumors, although the extent of the residual defect after excision may result in technical difficulties for the reconstruction. In tumors fixed to the periosteum or the deep layers, it is sometimes convenient to defer the wound coverage until after final histology is obtained with confirmation of margin clearance, reconstructing under conditions of oncological safety (6-9). Secondly, reconstruction must be a process of restoration form and function.
With the advent of new dermal substitutes, the choice of more demanding reconstructive procedures (i.e. pedicle or free flaps) becomes less compelling and the possibility of covering the exposed bone with a dermal matrix makes the reconstructive procedure easier and less cumbersome for the patient, reducing the costs of care and hospitalization. The new biomaterials are opening up easier and less stressful possibilities of reconstruction for the patient (less lengthy interventions, lack of morbidity of the donor areas, faster postoperative rehabilitation).
Many authors have contributed their expertise on the possibility of using dermal matrix for loss of substance with bone exposure (10-15). Some authors have integrated the use of negative pressure therapy with the use of the dermal matrix to increase local blood supply (13, 16, 17). Generally, wounds that do not have sufficient blood flow for the graft survival, with exposed bone or tendon, require the use of flaps. In particular at the calvarium, the amount of dermis influences the durability, functional, and esthetic properties of the skin graft. If the wound does not develop a well-vascularized granulation bed then local, distant or free flap coverage may be necessary, because the skin graft has a certain degree of failure of skintake, depending entirely on the re- and neovascularization arising from the wound bed (18, 19). Even today, for most patients, flaps remain the ideal treatment, but some patients are not candidates for complex reconstructive procedures that are often associated with long hospitalizations, risk of infection, thrombosis, and loss of flaps (20).
The dermal regeneration template for excellence is Integra® (Integra Lifesciences, Plainsboro, NJ), produced by organic synthesis; it consists of bovine collagen polymerized with co-polymers of glycosaminoglycan. It is the most widely used dermal substitute. Recently, Cordaro et al. reported the use of Integra® with cranioplasty for a complex scalp defect in the management of a 24-year-old patient with a history of severe cranial trauma with sinking of the frontal bone and dural laceration. After the positioning of the cranial implant, a single-layer Integra regeneration template was placed between the implant itself and the thinned skin layer. They observed that the use of Integra enabled good and appropriate reconstruction, with a normal forehead profile and thickness, without exposing the patient to a higher-risk procedure. They concluded that this dermal regeneration template allowed for appropriate coverage to be obtained and an optimal aesthetic outcome (21). In accordance with Cordero et al., we believe that in the absence of autologous dermis, staged reconstruction with a dermal equivalent or dermal regeneration template is required.
Comparison between Integra® and Hyalomatrix® templates considering origin of the material, action and cost.
We report our clinical experience of 10 cases of scalp reconstruction by another dermal induction template, named Hyalomatrix®. This bioresorbable dermal substitute of biological origin is made of HYAFF 11, a derivative of hyaluronic acid that acts as a scaffold for cellular invasion and three-dimensional neoangiogenesis. It can be used as a dermal substitute after skin removal as it provides excellent wound preparation to support the implantation of autologous skin grafts (3, 22). Advantages in using this template are its ease of use and the ability to induce neodermis formation to obtain optimal graft take after wide oncological demolitions. Firstly, this assured surgical radicality without cases of relapse, even for the most aggressive and infiltrating tumors. Secondly, reconstruction, restored form and function. We obtained good bone coverage with recovery of a sufficient soft tissue thickness and good morphology. Moreover, patients requiring oncological surgery of the scalp are often elderly, with comorbid illness, so that a complex reconstruction is not always recommended, and sometimes surgery has to be abandoned in favor of radiotherapy (23). We believe that in these cases, the use of this dermal template is a valid technical option that gives a good result, is accepted by patients, and is easy to apply.
Hyalomatrix® acts as a hyaluronan delivery system rather than a dermal regeneration template. The silicone membrane may limit wound bed colonization, and the combination of this temporary barrier with hyaluronan delivery and neodermis induction has been termed a barrier delivery-induction system. According to Myers et al., the development of similar systems for serial application offers an alternative to use of a dermal regeneration template (24). This aspect is very important to determine the most cost-effective treatment for deep and large skin defects. In Italy, the cost of treating each patient was 226.67 € for a 10×10 cm template of Hyalomatrix®, compared to 1350.00 € for a 10×10 cm template of Integra® (Table II) (25). Therefore, scalp reconstruction using Hyalomatrix® is a more cost-effective strategy.
To our knowledge, this is the first report on the use of Hyalomatrix® in oncological scalp surgery. We have used this product for scalp reconstruction after periosteum or diploic bone exposure with good results, including a remarkable quality of healing and a positive action on graft scarring. We now propose this two-stage procedure for critical patients with advanced oncological lesions of the scalp in whom general health conditions contraindicate more demanding reconstructive options (26).
Conclusion
Tissue engineering combines advances in cell culture technology with medical and surgical advances in science to allow for new solutions though synthetic substitutes and is increasingly effective and efficient. The results obtained up to this point indicate that the dermal substitutes have enormous potential to increase the therapeutic options available to the surgeon and benefit patients. The present study showed that the reconstruction of large post-oncological surgery scalp defects in critical patients with the use of Hyalomatrix® was successful. Its application to the periosteum and the diploic bone was effective, and resulted in savings compared with other techniques actually considered the gold standard. The lower morbidity compared to more demanding reconstructive procedures, and lower costs can make it preferable.
- Received September 18, 2012.
- Revision received October 17, 2012.
- Accepted October 18, 2012.
- Copyright © 2013 The Author(s). Published by the International Institute of Anticancer Research.
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