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

Mechanical force regulates the paracrine functions of ADSCs to assist skin expansion in rats

BACKGROUND

In the repair of massive tissue defects using expanded large skin flaps, the incidence of complications increases with the size of the expanded area. Currently, stem cell therapy has limitations to solve this problem. We hypothesized that conditioned medium of adipose-derived stem cells (ADSC-CM) collected following mechanical pretreatment can assist skin expansion.

METHODS

Rat aortic endothelial cells and fibroblasts were cultured with ADSC-CM collected under 0%, 10%, 12%, and 15% stretching force. Ten-milliliter cylindrical soft tissue expanders were subcutaneously implanted into the backs of 36 Sprague-Dawley rats. The 0% and 10% stretch groups were injected with ADSC-CM collected under 0% and 10% stretching force, respectively, while the control group was not injected. After 3, 7, 14, and 30 days of expansion, expanded skin tissue was harvested for staining and qPCR analyses.

RESULTS

Endothelial cells had the best lumen formation and highest migration rate, and fibroblasts secreted the most collagen upon culture with ADSC-CM collected under 10% stretching force. The skin expansion rate was significantly increased in the 10% stretch group. After 7 days of expansion, the number of blood vessels in the expanded area, expression of the angiogenesis-associated proteins vascular endothelial growth factor, basic fibroblast growth factor, and hepatocyte growth factor, and collagen deposition were significantly increased in the 10% stretch group.

CONCLUSIONS

The optimal mechanical force upregulates specific paracrine proteins in ADSCs to increase angiogenesis and collagen secretion, and thereby promote skin regeneration and expansion. This study provides a new auxiliary method to expand large skin flaps.

[Complications of head and neck expansion: Acting on modifiable factors. A study of 98 prothesis]

BACKGROUND

Tissue expansion is a key tool in the therapeutic arsenal that is proposed for repairing soft tissue losses of the head and neck. This technique, however interesting it may be, is not without its risks. The aim of this work is to identify the different steps of this procedure, determine the complications risk factors inherent to each step of the expansion and propose recommendations to improve functional and aesthetic results.

PATIENTS AND METHODS

We carried out a retrospective study on tissue expansion of the head and neck over a period of 10 years extending from January 2009 to December 2018, with at least one year follow-up for each patient. Our study counted 63 patients with the placement of 98 prostheses. We considered the various variables involved in the expansion process in order to determine those that increase the risk of complications.

RESULTS

In our series we counted 66.3 % of complications and 22.4 % of failures. We found that a young age increased the risk of skin suffering and that smoking increased the risk of hematoma occurrence. Neck expansion was found to be the riskiest site of expansion followed by the scalp that increased the risk of exposure (especially the parietal section of the scalp). The face is considered as an interesting site for expansion. We found that the use of multiple expanders is an attractive alternative to iterative expansions and to the choice of large expanders.

CONCLUSION

Tissue expansion of the head and neck requires careful planning that takes into account each step of the process.

Prefabricated Expanded Flap Combined With Expanded Scalp Flap for Total Face Resurfacing

ABSTRACT

Reconstruction of total facial deformities and defects has been a major challenge of reconstructive surgery. Allotransplantation is limited by the number of donors and the need for life-long immunosuppression. Autotransplantation, where multiple autogenous tissue grafts from various donor sites are used to repair facial defects, inevitably leaves conspicuous patchwork scars. A prefabricated monoblock flap, although the preferred treatment modality, is limited by insufficient blood supply and the large size of the flap. In the Journal of Craniofacial Surgery (2014;25:21-25), Li et al applied the technique of flap prefabrication and stem cell-assisted tissue expansion to reconstruct total facial injuries, but the operations were complicated and the final expanded flap area was also uncertain. This article introduces an approach to reconstruct total facial injuries with a prefabricated expanded thoracic flap combined with an expanded scalp flap (called combined flaps), which not only solves the limitations of blood supply and expanded volume but also reduces patchwork scars. The approach is a simple, feasible, and effective surgical method for total face resurfacing.

Infrared thermography-guided designing and harvesting of pre-expanded pedicled flap for head and neck reconstruction

BACKGROUND

Pre-expanded pedicled flaps possess a more flexible transfer pattern and higher tissue utilization than random flaps, but the perfusion is fully dependent on the chosen axial vessels. A precise mapping of the vessels would assist the surgical design and increase the likelihood of success. The application of Infrared thermography (IRT) has been previously reported for perforator location. The aim of this study is to report the use of IRT in mapping the course and distribution of axial vessels in the pre-expanded flap to guide the designing and harvesting.

METHODS

Patients who underwent head and neck reconstruction using pre-expanded flaps were included. After tissue expansion, IRT was used to mark the vessel distribution along the expanded flap. The results were compared with color Doppler ultrasound (CDU) and/or computed tomographic angiography (CTA). The flap was designed and raised based on the pre-operative marking by IRT. The mark was verified intraoperatively.

RESULTS

A total of 26 expanded flaps were performed, including 20 pedicled flaps and 6 free flaps. IRT succeeded to map the vessel distribution in all cases. All marked results were verified by CDU, CTA, and intraoperative dissection (26/26, 100%). IRT showed more comprehensive distribution of vascular branches than CDU or CTA, and could be utilized intraoperatively to identify the arteries.

CONCLUSION

IRT provides accurate and comprehensive mapping of the axial vessel distribution in the pre-expanded flaps, assisting with flap design and harvest. It is easy to use and non-invasive as an important tool pre- or intraoperatively to ensure the safe elevation.

The Use of Self-Inflating Hygroscopic Tissue Expanders to Facilitate Osteosarcoma Removal in a Massasauga Rattlesnake (Sistrurus catenatus)

A 0.34 kg adult female Massasauga rattlesnake (Sistrurus catenatus) was presented for evaluation of a subcutaneous mass affecting the ventral scales. The mass was diagnosed as a sarcoma via punch biopsy with no evidence of metastasis on diagnostic imaging. Surgical margins of 1-2 cm were planned to achieve complete excision of the neoplasm. A technique for tissue expansion was employed due to concerns regarding the ability to close the surgical site without excess tension or dehiscence. Two 27 mm diameter × 5 mm hygroscopic self-inflating tissue expanders were placed subcutaneously under the lateral scales adjacent to the mass. Maximum skin expansion occurred over a four-week period, and no direct negative effects were noted. Excision of the primary mass was performed routinely five weeks after implant placement. Primary closure of the defect was achieved with minimal tension by incorporating the expanded skin. While the surgery was successful with no evidence of metastasis, the snake died of sepsis two weeks postoperatively. This is the first report of the use of self-inflating hygroscopic tissue expanders to help close a surgical defect in a reptile.

Tissue Expansion Improves the Outcome and Predictability for Alveolar Bone Augmentation: Prospective, Multicenter, Randomized Controlled Trial

Objectives: The purpose of this study was to evaluate the effectiveness of the intraoral use of subperiosteally placed self-inflating tissue expanders for subsequent bone augmentation and implant integrity. Material and methods: A prospective, multicenter, randomized controlled trial was performed on patients requiring alveolar bone graft for dental implant insertion. Patients were assigned to three groups: tissue expansion and tunneling graft (TET group), tissue expansion and conventional bone graft (TEG), and control group without tissue expansion. Dimensional changes of soft tissue and radiographic vertical bone gain, retention, and peri-implant marginal bone changes were evaluated and secondary outcomes; clinical complications and thickness changes of expanded overlying tissue were assessed. Results: Among 75 patients screened, a total of 57 patients were included in the final analysis. Most patients showed uneventful soft tissue expansion without any inflammatory sign or symptoms. Ultrasonographic measurements of overlying gingiva revealed no thinning after tissue expansion (p > 0.05). Mean soft vertical and horizontal tissue measurements at the end of its expansion were 5.62 and 6.03 mm, respectively. Significantly higher vertical bone gain was shown in the TEG (5.71 ± 1.99 mm) compared with that in the control patients (4.32 ± 0.97 mm; p < 0.05). Hard tissue retention— measured by bone resorption after 6 months—showed that control group showed higher amount of vertical (2.06 ± 1.00 mm) and horizontal bone resorption (1.69 ± 0.81 mm) compared to that of the TEG group (p < 0.05). Conclusion: The self-inflating tissue expander effectively augmented soft tissue volume and both conventional bone graft and tunneling techniques confirmed their effectiveness in bone augmentation. With greater amount of bone gain and better 6 month hard tissue integrity, the TEG group compared to the control group—without tissue expansion—showed that the combined modality of tissue expander use and guided bone regeneration (GBR) technique may improve the outcome and predictability of hard tissue augmentation.

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.

Safety and Efficacy of Smooth Surface Tissue Expander Breast Reconstruction

BACKGROUND

Traditional 2-stage breast reconstruction involves placement of a textured-surface tissue expander (TTE). Recent studies have demonstrated textured surface devices have higher propensity for bacterial contamination and biofilm formation.

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of smooth surface tissue expanders (STE) in immediate breast reconstruction.

METHODS

The authors retrospectively reviewed consecutive women who underwent STE breast reconstruction from 2016 to 2017 at 3 institutions. Indications and outcomes were evaluated.

RESULTS

A total 112 patients underwent STE reconstruction (75 subpectoral, 37 prepectoral placement), receiving 173 devices and monitored for a mean follow-up of 14.1 months. Demographics of patients included average age of 53 years and average BMI of 27.2 kg/m2, and 18.6% received postmastectomy radiation therapy. Overall complication rates were 15.6% and included mastectomy skin flap necrosis (10.4%), seroma (5.2%), expander malposition (2.9%), and infection requiring intravenous antibiotic therapy (3.5%). Six (3.5%) unplanned reoperations with explantation were reported for 3 infections and 3 patients requesting change of plan with no reconstruction.

CONCLUSIONS

STEs represent a safe and efficacious alternative to TTE breast reconstruction with at least equitable outcomes. Technique modification including tab fixation, strict pocket control, postoperative bra support, and suture choice may contribute to observed favorable outcomes and are reviewed. Early results for infection control and explantation rate are encouraging and warrant comparative evaluation for potential superiority over TTEs in a prospective randomized trial.

LEVEL OF EVIDENCE: 4

Complications of tissue expansion in the head and neck

BACKGROUND

The authors aim to present a comprehensive review detailing the present state of evidence with regard to complications following tissue expansion in the head and neck.

METHODS

A systematic literature search was conducted to identify all studies reporting complications of tissue expansion in the head and neck between 2000 and 2019. Subgroup comparisons based on expander locations and planes were conducted.

RESULTS

A total of 7058 patients were included. Tissue expansion was associated with an overall complication rate of 8.73% (616/7058). The most common complications were extrusion (207/7009; 3.0%) and hematoma (200/7009; 2.9%). Overall complications were highest in the scalp (65/238; 27.3%) and lowest in the mastoid (347/5688; 6.1%). Complications were more common with expansion in the non-subcutaneous plane (63/590; 10.7%).

CONCLUSION

In the absence of large clinical trials, systematic reviews such as these can help inform clinical guidelines and provide practitioners with an evidence-based reference to improve informed consent.

The Combination of Expanded Scalp Flap and 800 nm Diode Laser in the Reconstruction of Forehead Defect

Skin grafting is often the first choice for closing forehead defects. However, the aesthetics of skin grafting-reconstructed forehead defects are still not accepted by a large number of patients. With the technological advancement of laser hair removal, scalp flaps have been considered as donors for reconstruction of forehead defects. We evaluated 10 cases of forehead defect reconstructions with expanded scalp flaps followed by hair removal by an 800 nm diode laser. All flaps survived uneventfully and underwent 4-6 laser treatments for hair removal. The appearances of the reconstructed foreheads were similar to that of the adjacent skin, and all patients were satisfied with the treatment outcomes during the 6-24 months of follow-up. It is concluded that the combined treatments of expanded scalp flaps and diode laser hair removal are effective for repairing forehead defects.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Autologous Stem Cell Transplantation Promotes Mechanical Stretch Induced Skin Regeneration: A Randomized Phase I/II Clinical Trial

Background

Mechanical stretch, in term of skin expansion, can induce effective but limited in vivo skin regeneration for complex skin defect reconstruction. We propose a strategy to obtain regenerated skin by combining autologous stem cell transplantation with mechanical stretch.

Methods

This randomized, blinded placebo-controlled trial enrolled 38 adult patients undergoing skin expansion presenting with signs of exhausted regenerative capacity. Patients randomly received autologous bone marrow mononuclear cell (MNC) or placebo injections intradermally. Follow-up examinations were at 4, 8 weeks and 2 years. The primary endpoint was the volume achieved in relation to the designed size of the expander (expansion index, EI). Secondary endpoints were surface area, thickness and texture of expanded skin. This trial is registered with ClinicalTrial.gov, NCT01209611.

Findings

The MNC group had a significantly higher EI at 4 weeks (mean difference 0.59 [95% CI, 0.03–1.16]; p = 0.039) and 8 weeks (1.05 [95% CI, 0.45–1.66]; p = 0.001) versus controls. At 8 weeks, the MNC group had significantly thicker skin (epidermis: p < 0.001, dermis: p < 0.001) and higher subjective scores for skin quality/texture (24.8 [95% CI, 17.6–32.1]; p < 0.001). The MNC group had more skin surface area (70.34 cm² [95% CI, 39.75–100.92]; p < 0.001). Patients in the MNC group gained up to the quadrupled surface area of expanded skin compared to pre-expansion at the end of expansion. No severe adverse events occurred.

Interpretation

Intradermal transplantation of autologous stem cells represents a safe and effective strategy to promote in vivo mechanical stretch induced skin regeneration, which can provide complex skin defect reconstruction with plentiful of tissue.

•

This study shows that intradermally transplanted MNCs in mechanical stretched skin is a safe and feasible clinical application.

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Intradermally transplantation of MNCs can overcome the regenerative limitations of skin.

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The strategy of combining stem cell and microenvironment can provide significant amounts tissue for surgical reconstruction.

Though stem cells are proved to participate in tissue regeneration, there is seldom clinical research combining stem cell and in vivo mechanotransduction to provoke skin regeneration. In this study, we introduce autologous bone marrow stem cells to mechanical stretch induced skin regeneration. The results showed that the potential of autologous stem cells in promoting skin regeneration. The application of stem cell assisted skin expansion can overcome the regenerative limitations of skin to provide significant amounts tissue for surgical reconstruction. The integration of stem cells and mechanical stretch stimuli will engender further advances in in vivo tissue regeneration.

Design, Manufacturing, and In Vitro Testing of a Patient-Specific Shape-Memory Expander for Nose Reconstruction With Forehead Flap Technique

Forehead skin is widely acknowledged as a good donor site for total nasal reconstruction, thanks to its matching color, texture, and abundant vascularity. The forehead flap technique uses an axial pattern flap forehead skin to replace missing nasal tissue. To increase the amount of available tissue and reduce the size of the tissue defect after flap mobilization, tissue expanders may be used. Although this is a relatively established technique, limitations include reduced moldability of the forehead skin (which is thicker than the nasal skin), and the need for multiple sessions of expansion to achieve a sufficient yield to close the forehead.Shape-memory metals, such as nitinol, can be programmed to "remember" complex shapes. In this work, the methodology for producing a prototype of nitinol tissue expander able to mold the skin in a predetermined patient-specific skin shape is described. A realistic nose mold was manufactured using metal rapid prototyping; nitinol sheet and mesh were molded into nose-shape constructs, having hyperelastic as well as shape-memory capability. Computed tomography scanning was performed to assess the ability of the structure to regain its shape after phase transformation upon cooling within 2% of initial dimensions. The prototypes were implanted in a pig forehead to test its ability to impose a nose shape to the forehead skin.The shape-memory properties of nitinol offer the possibility of producing bespoke tissue expanders able to deliver complex, precisely designed skin envelopes. The hyperelastic properties of nitinol allow constant preprogrammed expansion forces to be generated throughout the expansion process.

Changing the Donor Site Selection Concept of Facial Skin Expansion from Pure Healthy Tissue to Defect and Healthy Tissue Combination

Facial defect reconstruction is a challenge for plastic surgeons due to unique esthetic and functional properties of the region. Facial tissue expansion provides an ideal reconstruction resource. However, the donor site is limited in the facial region. Thus, a cost-effective expansion management is crucial for an efficient reconstruction. In this article, the evolution of our donor site preference for tissue expansion from pure healthy tissue to a defect-healthy tissue combination is presented. Fifteen patients underwent skin reconstruction with local tissue expansion for facial and cervical defects. The full facial or cervical region including the defect and healthy tissue combination was determined as the donor expansion site. The donor site was not limited only to pure healthy tissue. The largest size rectangular expander suitable for the combined expandable donor site size was placed under the defect and healthy tissue border, paying attention to carry the expander far beneath the defect site. The defect site and most adjacent healthy tissue were expanded simultaneously. Major complications such as infection, hematoma, rupture, or flap necrosis were not observed. The expansion of defect-healthy tissue border presented successful reconstruction results with acceptable scars. In the traditional tissue expansion concept, using a large size expander to provide more abundant flap gain does not comply with the limited size of healthy donor site in the face. Expanding the whole facial region, without restriction of the defect, supplies excess donor tissue area for larger size expander use. Eventually, defect-healthy tissue border expansion with large expanders results in minimum final scar and less tissue loss in flap relocation and enables optimal flap gain. This method can easily be adapted to any tissue expansion site of the body.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A single center experience of craniofacial tissue expansion and reconstruction

Introduction:

Tissue expansion is a versatile technique for craniofacial soft tissue defects. It has been extremely useful to restore the form and function along with good esthetics that were otherwise unobtainable.

Objectives:

To review the use of tissue expansion in the craniofacial region, with particular emphasis on indication, site, days, volume of the defect and tissue expansion used along with complications.

Materials and Methods:

Retrospective review of data on 18 expanded flap reconstructions performed in 14 patients during the period 2008–2013. Tissue expanders were placed on a subcutaneous plane above the fascia and inflated weekly. The expanded skin was used as a transposition flap for the reconstruction. Data were collected from archival records and tabulated in SPSS. Descriptive statistics, Kruskal–Wallis and Mann–Whitney tests were applied as required and a P ≤ 0.05 was taken as significant.

Results:

Trauma contributed to greater number of defects (57.1%). The most common defect occurs in face/cheek compartment (57.15%) followed by nose (35.71%). Owing to ease of access and better results, more expanders have been placed in cheek (50%), followed by neck (33.33%). The mean defect size was 2983.58 ± 828.27 mm², required 32.14 ± 6.31 days, 335.6 ± 156.51 ml in 5.29 ± 1.5 cycles of tissue expansion. The mean rate of expansion was 59.17 ± 16.27, 69.11 ± 30.19 and 62.6 ± 25.75 for forehead, face/cheek and neck cases respectively (P = 0.873).

Discussion:

Laxity of skin appears to be a good indicator of the rate of the expansion. The most favorable site for tissue expansion is cheek followed by neck. The study also shows that tissue expansion is an efficient and valuable technique for reconstruction of large craniofacial skin defects.

Tissue expanders in reconstruction of maxillofacial defects

Tissue expansion in its natural ways had fascinated man from prehistoric times itself. But tissue expansion for medical purposes was first tried and reported only in the early half of twentieth century. Presently the principle of tissue expansion is being used in reconstruction of many hard and soft tissue defects of larger dimension, which were previously regarded as great challenge for maxillofacial and plastic surgeons. Making use of the viscoelastic nature of the skin, considerable amount of tissue expansion based tissue engineering is possible in the maxillofacial region. Here we present a case of a facial scar of large dimension with a central oro cutaneous fistula developed as a result of facial artery blow out in a 24 year old female for which esthetic correction was done using the excess tissue obtained from tissue expansion. In this case where other methods of reconstruction such as local flaps, free flaps and normal tissue grafts were assessed to be non viable, tissue expansion was found to be an apt solution for esthetic reconstruction.