Key points

Video of adipose tissue harvesting by infiltration accompanies this article at http://www.plasticsurgery.theclinics.com/

Introduction

Adipose tissue is a connective tissue containing a reservoir of mesenchymal stem cells that can divide indefinitely, producing various cellular lines. Coleman’s processing and harvesting technique described in 1992 increased fat graft survival, making its adoption more reliable and predictable. Initially used as a filler to correct volume deficiencies and for esthetic purposes, autologous fat grafting has found a progressively greater field of application, and recently has entered regenerative medicine. The experience of Rigotti and coworkers in treating radiodystrophic outcomes obtaining local improvement of tegument trophic characteristics after autologous fat grafting was pioneering.

Inspired by these results, we applied the same technique to burn scars with excellent clinical results. Histologic examination of the treated skin showed patterns of new collagen deposition, local hypervascularity, and dermal hyperplasia with tissue regeneration. Building on these results, we began to treat other kinds of pathologic scars with an overall improvement in tissue quality. In our experience, autologous fat graft has proved to be an efficient and safe procedure to treat scars of different origin, demonstrating the capability of lipostructure to achieve architectural remodeling and loose connective regeneration.

In different clinical settings, we observed how lipostructure managed to relieve neuropathic pain thanks not only to regenerative effects, but also as a result of molecular changes induced in the microenvironment and secretion of substances able to give prolonged analgesia. Finally, we positively adopted its regenerative properties in the setting of posttraumatic “hard-to-heal” wounds, obtaining an improvement of healed skin quality and elasticity that appears very similar to normal skin.

Our clinical experience shows that autologous fat grafting can be adopted in different clinical settings by evolving reconstructive into regenerative surgery. It is well known that scars of different origin may impede function, especially in cases of joint involvement, which may cause discomfort, tightness, or even pain, and achieve cosmetic deformity. Several surgical approaches to treat scar tissue have been described, such as surgical excision and resuturing, Z-plasty, W-plasty, and geometric broken line suturing. However, all these revision techniques are adopted in selected cases and may achieve suboptimal results.

Skin ulcer can be extremely challenging to approach. Treatment is typically to avoid ulcer infection, remove any excess discharge, maintain a moist wound environment, control the edema, and ease pain caused by nerve and tissue damage. Although all these procedures are followed, ulcers do not frequently re-epithelize, showing a tendency to become chronic. This tendency is caused by several factors, such as anatomic location and patient condition, concomitant pathologies, drug assumption, previous local therapy, and smoking.

This article describes how autologous fat grafting regenerative properties can be applied in scar tissue and ulcer treatment.

Introduction

Adipose tissue is a connective tissue containing a reservoir of mesenchymal stem cells that can divide indefinitely, producing various cellular lines. Coleman’s processing and harvesting technique described in 1992 increased fat graft survival, making its adoption more reliable and predictable. Initially used as a filler to correct volume deficiencies and for esthetic purposes, autologous fat grafting has found a progressively greater field of application, and recently has entered regenerative medicine. The experience of Rigotti and coworkers in treating radiodystrophic outcomes obtaining local improvement of tegument trophic characteristics after autologous fat grafting was pioneering.

Inspired by these results, we applied the same technique to burn scars with excellent clinical results. Histologic examination of the treated skin showed patterns of new collagen deposition, local hypervascularity, and dermal hyperplasia with tissue regeneration. Building on these results, we began to treat other kinds of pathologic scars with an overall improvement in tissue quality. In our experience, autologous fat graft has proved to be an efficient and safe procedure to treat scars of different origin, demonstrating the capability of lipostructure to achieve architectural remodeling and loose connective regeneration.

In different clinical settings, we observed how lipostructure managed to relieve neuropathic pain thanks not only to regenerative effects, but also as a result of molecular changes induced in the microenvironment and secretion of substances able to give prolonged analgesia. Finally, we positively adopted its regenerative properties in the setting of posttraumatic “hard-to-heal” wounds, obtaining an improvement of healed skin quality and elasticity that appears very similar to normal skin.

Our clinical experience shows that autologous fat grafting can be adopted in different clinical settings by evolving reconstructive into regenerative surgery. It is well known that scars of different origin may impede function, especially in cases of joint involvement, which may cause discomfort, tightness, or even pain, and achieve cosmetic deformity. Several surgical approaches to treat scar tissue have been described, such as surgical excision and resuturing, Z-plasty, W-plasty, and geometric broken line suturing. However, all these revision techniques are adopted in selected cases and may achieve suboptimal results.

Skin ulcer can be extremely challenging to approach. Treatment is typically to avoid ulcer infection, remove any excess discharge, maintain a moist wound environment, control the edema, and ease pain caused by nerve and tissue damage. Although all these procedures are followed, ulcers do not frequently re-epithelize, showing a tendency to become chronic. This tendency is caused by several factors, such as anatomic location and patient condition, concomitant pathologies, drug assumption, previous local therapy, and smoking.

This article describes how autologous fat grafting regenerative properties can be applied in scar tissue and ulcer treatment.

Treatment goals and planned outcomes

In scar tissue–related problems and chronic ulcer, a proper assessment and adequate counseling before treatment are fundamental so that the patient is informed about the expected outcome. We indicate scar treatment with autologous fat graft in cases of wide nonlinear scars, in tension areas, or in cases of depressed scars. We propose treatment only on mature scars, giving a minimum threshold of 2 years from the causative factor. In all these clinical conditions surgical revision could result in a new and even worse scar than the previous one, whereas autologous fat graft and its regenerative properties are the more innovative surgical option.

Patients should be informed that their scars cannot disappear and the purpose of the procedure is local amelioration. Treatment goals include an increase in softness, flexibility, and extensibility of treated tissue with a release of scar bundles in superficial and deep planes, which can favor an improvement of mobility of the body district involved.

In the facial district treatment allows a partial restoration of facial mimic (kiss, smile, and other mood expression) because of the release of scar retraction. In cases of great skin depression a refill of these volume deficits can be obtained. In addition, pain symptoms related to scars can be reduced.

Patients should be informed that, after the first procedure, the result can be partial because of permanence of scar tissue retraction and depression. To obtain a satisfactory final result several procedures may be needed especially in more severe cases. Each procedure should be performed at least 3 months after the previous one to let fat graft manifest its regenerative effects. In some cases, scar release and local improvement can achieve a reduction of skin tension, allowing a secondary surgical scar revision.

In chronic ulcer, our experience suggests fat grafting effectiveness in treating areas of small to moderate size, not exceeding 3.5 cm ² . For bigger ulcer a combined approach with advanced dressing is needed. We treat posttraumatic ulcers that do not respond to advanced dressings. We are currently widening our indication to ulcers of different causes.

The aim of the treatment is to enhance the wound healing process relying on fat graft regenerative effects, obtaining a complete recovery of tissue integrity. Final re-epithelization can be obtained after more than a single procedure. As for scar treatment, pain symptoms related to ulcers, which highly affect patients’ quality of life, can be improved.

Preoperative planning and preparation

All patients selected for autologous fat graft procedure need a clinical assessment and routine preoperative examination. In case of scar treatment, preoperative markings are performed, asking the patient to note areas of greater tension and impairment to daily life activities and movements. In case of ulcer treatment, perilesional skin is marked.

Donor areas are abdomen and/or trochanteric and flank areas, given the easier access to abundant amounts of adipose tissue. Donor site is chosen according to the amount of adipose tissue, if previous surgery has been made, and according to patient preference. The areas are generally not marked before surgery.

Procedural approach

The patient is placed lying down, prone or supine according scar location. Surgical procedure is performed under local anesthesia and sedation assisted with sterile technique. We proceed to infiltration of the donor areas using a blunt cannula filled with anesthetic solution (100 mL saline solution, 10 mL of levobupivacaine 7.5 mg/mL, 20 mL of mepivacaine 10 mg/mL, and 0.5 mL epinephrine 1 mg/mL). Infiltration provides good hemostasis and adequate operative and perioperative analgesic action ( [CR] ).

Adipose tissue is harvested through the same incision by infiltration of anesthetic solution, with blunt cannulas of 2 to 3 mm in diameter of variable length (between 15 and 23 cm). The cannula used for sampling is connected with a Luer-lock syringe of 10 mL. The syringe plunger is pulled at the top and secured by hand. This creates inside the syringe a slight negative pressure, which allows the levy of adipose tissue while the cannula is advanced and retracted with radial movements inside the donor area ( [CR] ). When full, the syringe is placed in a centrifuge with resterilized containers and adipose tissue is centrifuged at 3000 rpm for 3 minutes.

Following centrifugation three distinct layers are obtained; only the intermediate one is needed for therapeutic purposes. In our experience centrifugation following the Coleman technique is the ideal processing method to obtain a final product purified and enriched with higher regenerative properties. We have recently demonstrated that centrifugation does not impair cell viability, increasing the content of adipose-derived stem cells and reducing the amount of proinflammatory blood cells. Centrifugation concentrates a higher number of viable cells with regenerative potential in a smaller amount of inoculum, thus making this method ideal for the treatment of retracting scar tissue and ulcers.

Fat is transferred from a 10-mL syringe into a 1-mL syringe Luer-lock that allows precise control of the amount of injected fat and better handling. The adipocyte fraction is injected using an 18-gauge angiographic needle with a snap-on wing (Cordis®; Johnson & Johnson, Roden, the Netherlands). The use of needles is fundamental to treat scar tissue. In our clinical experience, blunt cannulas are not the ideal instruments to perform a quick, safe, and painless procedure and better results are achieved with sharp angiographic needles.

Over the years we have found that scar tissue derived from any factor is characterized by overflowing fibrous tissue that achieves a significant resistance to the sliding of the cannulas used for fat injection. Through an 18-gauge angiographic needle, we are able to perform a highly precise technique, overcoming tissue resistance related to the presence of fibrous tissue, thus making it possible to lay a constant amount of fat at the dermal-hypodermal junction by multiple radiating passages that distribute fat in all directions, creating an ideal web to support damaged areas ( [CR] and [CR] ).

Lysis of scar tissue is obtained by two different methods. The first consists of pushing the plunger of the syringe and exploiting the strength of exiting fat to overcome the fibrous tissue resistance. In the second method we adopt a retrograde technique entering the needle for its entire length at the dermal-epidermal junction and then, while extracting the needle, releasing fat.

We believe that sharp cannula stimulates new collagen deposition and remodeling of fibrous tissues, in a fashion similar to the “needling” procedure used in aesthetic medicine. Moreover, 18-gauge angiographic sharp needles are disposable and low-cost devices compared with classic blunt cannulas.

The amount of injected fat at each passage is minimized to avoid irregularities and clusters, which are eventually deleted with digital manipulation after the procedure.