Tissue Expansion in the Head and Neck

An Overview of Scaffolds and Biomaterials for Skin Expansion and Soft Tissue Regeneration: Insights on Zinc and Magnesium as New Potential Key Elements

The utilization of materials in medical implants, serving as substitutes for non-functional biological structures, supporting damaged tissues, or reinforcing active organs, holds significant importance in modern healthcare, positively impacting the quality of life for millions of individuals worldwide. However, certain implants may only be required temporarily to aid in the healing process of diseased or injured tissues and tissue expansion. Biodegradable metals, including zinc (Zn), magnesium (Mg), iron, and others, present a new paradigm in the realm of implant materials. Ongoing research focuses on developing optimized materials that meet medical standards, encompassing controllable corrosion rates, sustained mechanical stability, and favorable biocompatibility. Achieving these objectives involves refining alloy compositions and tailoring processing techniques to carefully control microstructures and mechanical properties. Among the materials under investigation, Mg- and Zn-based biodegradable materials and their alloys demonstrate the ability to provide necessary support during tissue regeneration while gradually degrading over time. Furthermore, as essential elements in the human body, Mg and Zn offer additional benefits, including promoting wound healing, facilitating cell growth, and participating in gene generation while interacting with various vital biological functions. This review provides an overview of the physiological function and significance for human health of Mg and Zn and their usage as implants in tissue regeneration using tissue scaffolds. The scaffold qualities, such as biodegradation, mechanical characteristics, and biocompatibility, are also discussed.

Expansion microscopy: A revolution in diagnostic pathology

Expansion microscopy (ExM) is a recent discovery in diagnostic pathology and microbiology that promotes a physical magnification of the tissue specimen instead of optical magnification. It not only improves the resolution of the specimen but also enhances the diagnostic precision, and permits nanoscale imaging of the specimen. Optical microscopy is routinely used in histopathology and microbiology for ages. Due to its simplicity, compatibility with different types of specimens, and ease of operation it is accepted by pathologists. ExM and its variants have been widely tested in different types of tissue specimens and microbiological specimens and yielded brilliant results.

Cell-free fat extract promotes tissue regeneration in a tissue expansion model

Background

Tissue expansion techniques play an important role in plastic surgery. How to improve the quality of the expanded skin and shorten the expansion period are still worth investigating. Our previous studies found that a cell-free fat extract (CEFFE) possessed pro-angiogenic and pro-proliferative activities. However, the role of CEFFE on tissue expansion has remained unclear. The purpose of this study was to evaluate the effect of CEFFE on tissue expansion.

Methods

A rat tissue expansion model was used. Animals were treated with CEFFE by subcutaneous injection. After 4 weeks of tissue expansion, the skin necrosis and retraction rates were evaluated, the thicknesses of the epidermis and dermis were determined by histological analyses, blood vessel density was measured by anti-CD31 staining, cell proliferation was assessed by proliferating cell nuclear antigen staining, and the expression of specific proteins was evaluated by western blot analyses. In addition, the effects of CEFFE on the proliferation and cell cycle of cultured HaCaT cells were evaluated in vitro.

Results

CEFFE treatment significantly decreased the necrosis rate and retraction of the expanded skin. The thickness of the epidermal and dermal layers was higher in CEFFE-treated compared to untreated skin. The density of blood vessels and cell proliferation in the epidermis of the expanded skin was improved by CEFFE treatment. In addition, CEFFE treatment significantly increased the expression of the vascular endothelial growth factor receptor, epidermal growth factor receptor, collagen type 1, and collagen type 3. CEFFE also increased the proliferation of HaCaT cells in culture.

Conclusions

CEFFE improves the quality of the expanded skin by promoting angiogenesis and cell proliferation. It could be potentially used clinically for augmenting tissue expansion.

Full-Thickness Skin Grafting for Local Defect Coverage Following Scalp Adjacent Tissue Transfer in the Setting of Cranioplasty

INTRODUCTION

Numerous techniques have been described to overcome scalp deficiency and high-tension closure at time of cranioplasty. However, there is an existing controversy, over when and if a free flap is needed during complex skull reconstruction (ie, cranioplasty). As such the authors present here our experience using full-thickness skin grafts (FTSGs) to cover local defects following scalp adjacent tissue transfer in the setting of cranioplasty.

METHODS

By way of an institutional review board-approved database, the authors identified patients treated over a 3-year period spanning January 2015 to December 2017, who underwent scalp reconstruction using the technique presented here. Patient demographics, clinical characteristics, technical details, outcomes, and long-term follow up were statistically analyzed for the purpose of this study.

RESULTS

Thirty-three patients, who underwent combined cranioplasty and scalp reconstruction using an FTSG for local donor site coverage, were identified. Twenty-five (75%) patients were considered to have "high complexity" scalp defects prior to reconstruction. Of them, 12 patients (36%) were large-sized and 20 (60%) medium-sized; 21 (64%) grafts were inset over vascularized muscle or pericranium while the remaining grafts were placed over bare calvarial bone. In total, the authors found 94% (31/33) success for all FTSGs in this cohort. Two of the skin grafts failed due to unsuccessful take. Owing to the high rate of success in this series, none of the patient's risk factors were found to correlate with graft failure. In addition, the success rate did not differ whether the graft was placed over bone verses over vascularized muscle/pericranium.

CONCLUSION

In contrary to previous studies that have reported inconsistent success with full-thickness skin grafting in this setting, the authors present a simple technique with consistent results-as compared to other more complex reconstructive methods-even in the setting of highly complex scalp reconstruction and simultaneous cranioplasty.

Tissue expanders; review of indications, results and outcome during 15 years' experience

BACKGROUND

Tissue expanders (TE) are frequently used worldwide. In this study we surveyed outcome of our patients retrospectively during 15 years.

MATERIALS AND METHODS

We had 1105 patients for whom 3059 TEs have been used. Demographic data, age, sex, indications, type of tissue expander devices, volume of devices, site of scar and site TE insertion, our technique for tissue expander insertion and flap design, complications and outcome were gathered. A complete and through technical points and tips will be discussed.

RESULTS

In 91% of patients overexpansion was done. (Expansion ratio=2.1-4.5). Re-expansion has been done in about 12% of patients. Complications were perforation of skin of pocket (11%) or exposure, infection (6%), dehiscence of the wound (1.5%), perforation of the port or disconnection of the tubes (2.1%), expansion of the scar itself (1%), saggy flap (3%), dog ear (5%), lack of adhesions of flap to its new site (4%).

OUTCOME

In 93% of the patients we could totally remove the scar. Around 9.1% of our patients had two sessions of expansion in the same area and 2.9% had three sessions of expansion. 51% of our patients were highly satisfied and 42% were satisfied of the results of expansion.

CONCLUSION

Our patients were satisfied with the results. In 12% cases we have done re-expansion. Re-expansion is possible as long as you have enough thickness of dermis in the skin. More than 50% of our patients were optimistic for 2nd or 3rd session of re-expansion.

A Crossover Reconstruction Between the Forehead Expansion and Upper Eyelid Skin

BACKGROUND

In cosmetic surgery, the authors have successfully used forehead expansion for reconstruction of the upper eyelid, and have found it to be indispensable for reconstruction of the upper eyelid. In such an operation, preserving the eyebrow is often a problem, and they suggest an approach in 2 stages, which allows us to both save the eyebrow and use the expander flap at the same time. In the last 6 years, they have performed 5 forehead expansions for total upper eyelid skin reconstruction, achieving very good aesthetic outcomes.

METHODS

Firstly, the authors measure the defect and choose an appropriate expander implant for the forehead. Secondly, they cut out the pathologically changed-turned red or scarred-skin to protect the eyebrow. Next they get out the tissue expander and use the tissue flap to repair the upper eyelid defect, while the eyebrow is under the expander flap, covered by skin, which they originally cut from the upper eyelid. Three weeks later they can cut down the pedicel and the flap becomes the new upper eyelid skin.

RESULTS

The authors find that the new upper eyelid skin may be vascularized by dermatological vessels from the expander flap. The forehead expander flap is reliable and particularly well suited for an upper eyelid, with numerous advantages. In this way, they make maximal use of the expander flap and no additional incision is needed.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Role of systematic scalp expansion before cranioplasty in patients with craniectomy defects

PURPOSE

Scalp management is challenging in all types of cranioplasties, particularly following decompression or in case of resorption of a repositioned bone flap. In these cases, reduction of brain volume is constantly associated with tightening of the skin cover.

MATERIAL AND METHODS

A retrospective analysis of 36 cranioplasties was performed. All patients showed cranial decompression or a large craniectomy. In all cases, cranioplasty was preceded by a preliminary scalp expansion.

RESULTS

Two patients had expander exposure. One of them underwent re-intervention, to reposition the implant. Complications of the cranioplasty phase were one case of extradural hematoma, five cases of swelling due to liquorrea, four cases of temporary forehead edema, and one case of temporal bulging due to the implant. Cranial decompression and other craniectomy procedures often produce a tightening of the scalp, which makes the cranioplasty problematic. The preliminary systematic scalp expansion performed in all patients resulted in a convenient skin excess that allowed a tension-less closure, preventing the scalp suture from falling right on the edge of the cranioplasty implant.

CONCLUSION

A systematic preliminary scalp expansion allows one to minimize cranioplasty complications in patients with craniectomies, to anticipate possible necrotic scalp complications in the expansion phase rather than in the cranioplasty phase, and thereby avoid implant loss.

[Cheek reconstruction]

We describe the different cheek reconstruction techniques with primary emphasis on the superficial layers. In addition to the clinical context, location and size of the lesion will be taken into account to choose the best method that will optimize the functional and aesthetic results while minimizing potential sequelae. Main evaluation criteria include absence of natural orifice deformation, scar location, skin cover quality and respect of volumes.

Treatment of a congenital melanocytic nevus on the forehead with immediate tissue expansion technique: a three-year follow-up

The aim of this case report was to determine the method and basic principles of immediate tissue expansion using a Foley catheter in the forehead region for treating a medium-sized congenital melanocytic nevus. A 4-year-old child presented with a supraorbitally located forehead congenital melanocytic nevus, close to the midline. Total excision and reconstruction with intraoperatively expanded forehead skin below the hairline was performed. Intraoperative tissue expansion using a Foley catheter allowed us to obtain expanded and enhanced local tissue, which had tissue characteristics similar to those of the forehead skin, and thus closure of a medium-sized defect without distorting important anatomic structures such as the brow and frontal hairline was possible. Of the two methods of tissue expansion, immediate expansion using a Foley catheter is a good alternative in single-stage reconstruction of head and neck defects because it has the advantage of omnidirectional expansion.

Successful treatment of large forehead defect after the failure of tissue expansion: changing plan and strategy

Tissue expansion is an effective method in head and neck reconstruction for large defects. Tissue expansion allows enlarged local tissue for advancement or rotation flaps and could result in satisfactory aesthetic and functional outcomes. A 14-year-old boy presented with a 7 × 9-cm(2) traumatic defect on his forehead. We planned a 2-stage operation with tissue expanders. In the first operation, we placed two 100-mL crescent-type tissue expanders supraperiosteally through the scalp hairline incision. After the seventh postoperative day, failure of one of the expanders was found. Hence, we overexpanded the remaining expander using rapid inflation for 7 days (20 mL/d) and changed the plan of the flap design from a bilateral advancement flap to a supratrochlear artery-based unilateral rotational flap. The patient healed uneventfully and had satisfactory results 1 year postoperatively. To overcome tissue expansion failure, an overexpansion technique with multiple small crescent-type expanders was used; a rotational flap based on the supratrochlear artery is a good alternative method.

Tissue expanders for soft tissue reconstruction in the head and neck area--requirements and limitations

OBJECTIVES

The repair of skin defects in the head and neck region still poses a significant problem for many clinicians. Tissue expansion is described as a treatment option providing good color, texture, and thickness match of the expanded skin. Unfortunately, the complication rates for tissue expansion range from 0 to 48 %. Therefore, the purpose of this study was to investigate risk factors for the use of tissue expanders in head and neck reconstructions.

MATERIALS AND METHODS

Forty-nine patients with skin deficits in the head and neck area underwent tissue expansion. Sixty-two implanted expanders were analyzed regarding the various complications and the success rate.

RESULTS

The success rate of treated patients was 37 (75.5 %) of all 49 included patients. The most frequent cause for the skin deficit was a tumor resection near the tip of the nose followed by skin deficits resulting after craniectomy. Interestingly, a higher number of expanders and a larger volume were significantly associated with a worse outcome. There was a trend of association between larger defect size and failure, too.

CONCLUSIONS

The internal tissue expansion is a suitable technique for skin reconstruction in the head and face area. Compared to distant or free flaps, it often offers a better cosmetic outcome. In very large defects (>100 cm(2)) or when more than two expanders are needed, the failure rate increases. In these cases, other treatment options are recommended.

CLINICAL RELEVANCE

The internal tissue expansion is a suitable technique for skin reconstruction in the head and face area.

Reconstruction of a large scalp defect by the sequential use of dermal substitute, self-filling osmotic tissue expander and rotational flap

Large scalp defects pose a challenge for the surgeon. Here, we present a 31-year-old male patient with a soft tissue defect on the temple with exposed bone. To allow reconstruction, we placed a self-filling osmotic expander in the subgaleal pocket for 12 weeks. The final volume of the tissue expander was 300 mL. In the last step, a rotational flap was created after removal of the tissue expander from its pocket. Thereby, a tension-free suturing was possible. The post-surgical healing was uncomplicated. Osmotic tissue expanders are a valuable tool for the closure of large tissue defects without the necessity of repeated filling procedures.

Scrotal reconstruction using rapid intraoperative tissue expansion: a preliminary report

PURPOSE

Extensive scrotal skin loss can pose a difficult management problem. In most cases delayed scrotal approximation is feasible due to the redundancy of scrotal skin. However, large defects usually require reconstruction using flaps or grafts. We present a novel technique of scrotal closure using rapid intraoperative tissue expansion to manage select extensive partial scrotal defects.

MATERIALS AND METHODS

Between January 1996 and April 2006, 3 patients underwent delayed closure using rapid intraoperative tissue expansion for approximately 75% scrotal skin loss. Intraoperatively the residual lateral scrotal and medial thigh skin, and subcutaneous tissues were dissected, creating bilateral cavities for the placement of round 300 cc tissue expanders. Gradual inflation for a total of 20 minutes allowed adequate tissue expansion of the 2 thigh flaps, enabling tension-free scrotal closure.

RESULTS

Each patient was followed for 12 months. The resulting reconstruction provided a tension-free, cosmetically appealing scrotum with complete testicular coverage. There were no perioperative or postoperative complications.

CONCLUSIONS

Although rapid intraoperative tissue expansion has been successfully used for the closure of facial and extremity defects, to our knowledge it has not been described for genital skin loss. Our experience suggests that this relatively simple method is a viable addition to the reconstructive armamentarium in a select group of patients with extensive scrotal skin defects that are not amenable to scrotal approximation alone.

Advances in scalp reconstruction

PURPOSE OF REVIEW

The present review summarizes traditional and advanced techniques used to reconstruct defects of the scalp. These deformities range from small defects that can be closed primarily to significant defects, which require free tissue transfer.

RECENT FINDINGS

Increased use of tissue expanders, advancement rotational flaps, and hair transplantation has resulted in improved cosmetic outcomes for larger defects of the scalp. Free tissue transfer has provided a revolutionary method of reconstructing subtotal and total defects of the scalp, in particular those associated with neoplasms.

SUMMARY

New advances in techniques of scalp reconstruction have provided improved outcomes in terms of cosmetic appearance and decreased morbidity for scalp reconstruction.