Local Tissue Rearrangement for Hypertrophic Chemical Burn: Z-Plasty and VY-Plasty

Abstract

Hypertrophic scarring following burn injuries has been shown to occur in up to 70% of patients, potentially causing both long-term psychological and physical morbidity. Increased rates of depression and anxiety are seen to arise from aesthetic dissatisfaction, affecting patient rehabilitation and subsequent societal interaction. Mobility is jeopardized from contractures that develop within the damaged tissue, leading to decreased range of motion and function of the area. Both sequelae leave the patient with an overall decreased quality of life. Surgical techniques involving local tissue rearrangement, including Z-plasty and VY-plasty can be employed to improve both the function and cosmetic effects of burn scars. Essentially, these techniques illicit a decrease in tension through a lengthening of contracted tissue of up to 50–70%, allowing for better static alignment and increased mobility over joint surfaces. This video depicts the combination of both tissue rearrangement techniques as applied to hypertrophic scar contractures resulting from prior burn injuries. The authors find these techniques an invaluable part of a reconstructive surgeons' armamentarium when approaching scar revision.  

Case Overview

Background

Chemical burns from acidic agents, as seen in this case, cause damage through coagulation necrosis and cytotoxicity. Much like more common thermal injuries, this leads to protein destruction and structural changes in the tissue directly contacted by the chemical. Initial treatment involves immediate, low-pressure irrigation of the affected area to completely remove the agent and prevent the spread. Decontamination can take hours depending on the type of agent and the extent of the injury. The patient can then be treated as a typical burn case, with fluid resuscitation and precautions for hypothermia, infection, and rhabdomyolysis.¹ Standard of care surgical efforts to promote healing in deep burns utilize early excision and coverage with split-thickness skin autograft.² This management doubles as both a prophylaxis for the development of infection and a means for the reduction of severe scarring. 

The pathogenesis of scar formation progresses in three precise phases: inflammation, proliferation, and remodeling.³ Alteration in any one of these can delay the healing process. Stage one lasts for several days where early hemostasis management is achieved through the creation of a fibrin clot. Then cytokine reactions initiate recruitment of the major cell types responsible for the restoration of the skin barrier. The proliferative phase is predominated by collagen and scaffolding molecule formation through activation from deep dermal fibroblasts. The fibroblasts also stimulate myofibroblasts, which are responsible for wound contraction. Epithelialization occurs at this time as well from cell migration over the transitional extracellular matrix.⁴ The final phase of maturation and remodeling can continue for years and has the most potential for individual variation in scar qualities. 

Both the genetics of a patient and the traits of the tissue play a role in abnormal scarring processes. Hypertrophic scars are those that are raised above the skin level but remain within the original area of skin injury, typically resulting from an overproduction of collagen.⁵ They can arise after a variety of cutaneous injuries that involve the reticular dermis such as trauma, burns, surgery, skin piercing, and infectious diseases. High-risk areas for formation include places on the body that experience dynamic tension or areas of naturally tight skin. Hypertrophic scarring is the most common type of scar tissue in a severely burned patient and can be predominantly widespread. The hallmark is a dysregulation in collagen with the reduced replacement of type III with type I collagen. Excessively tight collagen bundles, along with absent elastin—for approximately 5 years after a burn—and pro-fibrotic T cells decrease skin malleability.² The resulting scar creates an area of skin that is thick, irregularly contoured, stiff, itchy, and painful.² In general, the longer a burn takes to heal, the greater the risk for pathologic scarring.

Focused History of Patient

Here we present an otherwise healthy 18-year-old male with a past medical history of six-year-old chemical burns located to the right and back of his neck, and the right side of his face. He had multiple prior surgeries, including skin grafts, and tissue rearrangements for these hypertrophic scars. The patient’s chief complaint was extreme tightness in the scar tissue at the midline of his neck severely limiting mobility, particularly during recreational sporting activity. The area contains both normal and abnormal skin that has undergone hypertrophy as a result of chronic motion.

Indications

Indications for this surgery are the release of contractures, realignment along Langer lines (natural skin folds) relieving skin tension, increasing mobility, and creating a more cosmetically pleasing appearance of the scar.⁵ Considering this patient’s extensive surgical history, a small procedure with an effective outcome was favored. 

Contraindications

There are no absolute contraindications for this surgery. Each case is evaluated individually to assess for the most appropriate surgical intervention(s). Before performing this surgery, one should take into consideration the following factors: smoking, poor glycemic control, current steroid use, and history of hypertrophic scarring or vascular disease, which can play a role in perioperative bleeding and postoperative healing.⁶ Additionally, patient priorities, the ability for rest and recovery, and the ability to follow up, or undergo additional procedures should be considered prior to intervention. 

Procedure

The patient’s neck was surveyed to determine the best location and tissue to use. A small area on the right anterior neck and a larger area at the anterior midline neck were decided as the most advantageous locations for a typical Z-plasty and a Z- and VY-plasty, respectively. These locations were marked using a sterile marker and checked for correct Langer line alignment. Local anesthetic was infiltrated along the marked sites. At the midline site, an incision in the central limb was made, with the plane of dissection for both plasty procedures being in the subcutaneous tissue. Cautery and suction were used to gain control of the bleeding and clear the surgical field. Mosquito forceps helped bluntly dissect the subcutaneous tissue area to locate a tether point for the transposition of the tips. Then the VY-plasty was started by creating incisions along the remaining lines. In the closure of the plasty, first monofilament Prolene sutures were used to secure the tips to ensure appropriate alignment. Simple interrupted sutures were then used for placement of tension-relieving stitches and secondary sutures equilibrizing the tension. The second plasty was within a skin grafting area, with the angles more obtuse to orient the longitudinal scar into the transverse direction. After incision along the markings, forceps were again used to bluntly dissect the subcutaneous tissue, allowing the wound to pop open. The same closure technique was used, placing first the tip and then the tension-relieving sutures.  

Discussion

Surgical interventions are considered only after non-surgical therapies to reduce the hypertrophic scar have failed.³ It is preferred to wait approximately one year after the event, allowing time for scar maturation.⁷ Due to the relative avascularity of the scar, there is a reduced potential for bleeding, poor graft take, and further damage. Treating contractures should generally be completed through immediate, incisional release. This decreases the requirement for a skin cover in one procedure, providing more immediate results. Once the release has been achieved in a post-burn contracture, skin cover decisions can be contemplated. The major options are split-skin grafts and skin flaps. The former is used for all contractures as a general rule, allowing the donor site to heal independently of the recipient site.⁸ The use of skin flaps is more limited, only being used in specific situations when open joints or cosmetic concerns need to be addressed. Local flaps are helpful post-graft maturation when contracting bands form around the skin junction, and the wound does not follow Langer’s tension lines, impeding the normal range of motion of joints. This situation is particularly true in the pediatric burn population due to the inability of hypertrophic scars to grow to accommodate the growth of long bones.  

The two utilized flap procedures, in this case, are the Z-plasty and VY-plasty. Z-plasty procedures change the length and orientation of a scar. There are a variety of different types of Z-plasties, with chosen configuration tailored to fit with the surrounding skin and scar tissue. The most basic version consists of three equal length limbs that make two 60° triangular flaps (Figure 1). The middle limb is situated along the axis of the scar. This allows lengthening of the contracture theoretically by around 75% and reorientation by 90°.⁸ By adjusting the length and angle of the limbs, increased lengthening of the scar can be obtained. However, angles that are too large or too small create further complications for the flap. Angles larger than 75° cause too much skin tension, while angles less than 45° are linked to a higher risk of flap necrosis due to compromised blood flow to the tips. 

Figure 1: Z-Plasty. The Z-Plasty procedure shown with the transposition of the two flaps. The initial line is perpendicular to the Langer lines. By incising and transposing the flaps to the opposite corners, the scar undergoes 90° rotation, decreasing tension.

The VY-plasty can be used to cover small defects and lengthen structures (Figure 2). The main differences between the two procedures revolve around complication risk and dimensional considerations. The flap created in this configuration has a lower risk of vascular compromise due to having maintained its subcutaneous pedicle, thereby reducing the risk of flap necrosis.² Therefore, without dimensions being limited due to perfusion considerations, more individualized sizes can be created. The original base, called the leading-edge, guides the height of the triangle, usually 1.5 to 2 times its length. When deciding orientation, the tip of the triangle is placed in line with the contracture, resulting in the transposition of extra tissue in line with the contracture. 

Figure 2: VY-Plasty. VY-Plasty closure is depicted here. It is a modified flap used for small and medium defects, that preserves vascular supply. A triangular incision is made that alleviates tension through suturing the lateral sides to each other and the created flap. 

Preoperatively, the surgeon should evaluate the scar, assessing the skin for laxity, quantity, and orientation. These factors determine the most appropriate variant of Z-plasty to use and the most advantageous location. The surgeon should also assess the risk of wound site infection, potentially placing the patient on prophylactic antibiotics and advising cessation of anticoagulants or antiplatelet drugs to prevent excessive bleeding. Finally, meticulous preoperative marking of the planned incision ensures correct orientation and alignment of flaps. After the procedure, patients can use over-the-counter pain relievers and would rarely require narcotic pain relief. Clinical examination of the surgical site should take place within one to two days, and sutures can be removed after 2 weeks. 

The most common complications occurring after Z-plasty and VY-plasty procedures include flap necrosis, wound infection, and the development of a subcutaneous hematoma.⁹ Wound tension can also occur and cause sloughing of the created flap. The trap-door phenomenon—where the central tissue of a flap becomes elevated due to the downward pull of the surrounding scar—is also a common complication.⁹ With careful planning and meticulous surgical technique, most complications can be avoided.¹⁰ It is important to inform patients of the possibility of adjuvant treatments and the need for further procedures. 

Equipment

Steven scissors

#15 scalpel blade

Electrocautery unit

Suction device

Forceps

Local anesthetic 

4-0 and 5-0 Prolene suture

Disclosures

The authors have no financial interests to disclose in relation to this work.

Statement of Consent

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.