Surgical treatment of pressure injuries in children: A multicentre experience

Abstract Pressure injuries (PI) are infrequent in paediatric patients, prevalence estimates ranging from 1.4% to 8.2%, and reaching values as high as 43.1% in critical care areas. They can be associated with congenital neurological or metabolic disorders that cause reduced mobility or require the need for medical devices. In children, most pressure injuries heal spontaneously. However, a small percentage of ulcers that is refractory to conservative management or is too severe at presentation (Stage 3 or 4) will be candidates for surgery. We retrospectively reviewed the clinical history of paediatric patients affected by pressure injuries from four European Plastic Surgery Centres. Information was collected from clinical and radiology records, and laboratory reports. An accurate search of the literature revealed only two articles reporting on the surgical treatment of pressure injuries in children. After debridement, we performed surgical coverage of the pressure injuries. We report here our experience with 18 children aged 1–17 years, affected by pressure injury Stages 3 and 4. They were successfully treated with pedicled (17 patients) or free flaps (1 patient). The injuries involved the sacrum (6/18 patients), lower limb (3/18 patients), thoracic spine (2/18 patients), ischium (3/18 patients, bilateral in one patient), temporal area (3/18 patients), hypogastrium (1/18 patients) and were associated to medical devices in three cases. Flaps were followed for a minimum of 19 months and up to 13 years. Only two patients developed true recurrences that were treated again surgically. Pressure injuries are infrequent in children and rarely need surgical treatment. Pedicled flaps have a high success rate. Recurrences, contrary to what is reported in the literature, were rare.


| INTRODUCTION
A pressure injury (PI) is defined as localized damage to the skin and underlying soft tissue, usually over a bony prominence or related to medical or other devices. 1 In 2016, the National Pressure Ulcer Advisory Panel (NPUAP). 1 suggested that the term injury be used instead of ulcer and that the stages be denoted using Arabic rather than Roman numerals.
The NPUAP's staging system that describes the extent of tissue loss and the physical appearance of the injury caused by pressure and/or shear, progressing from Stages 1-4, has been widely adopted internationally and has become the basis for treatment and comparison of outcomes. A particular type of PI's are the unstageable pressure injuries, full-thickness lesions in which the base is obscured by slough and/or eschar and whose correct identification can be challenging. 1 Detailed artwork describing the appearance of different stages, as agreed upon during the Consensus, can be found in reference. 1 PIs can be painful, can be complicated by infection, impact negatively on the quality of life, and heal with difficulty, despite the availability of many therapies and preventive measures, none of which has been demonstrated to be superior to the others. 2 Although they are more frequent in the adult, and especially in the geriatric population, pressure injuries can develop also in children. 3 Aetiology is variable, but the most important role is played by medical conditions that cause reduced mobility or require the need for medical devices, that are responsible for PIs in 38.5%-90% of paediatric cases. Patients with this type of PI tend to be younger. 4,5 Visscher and Taylor 4 evaluated Neonatal Intensive Care Unit (NICU) patients between 2007 and 2009. They found that nearly 80% of the PIs were associated with devices, and more than 90% of device-related PIs occurred in the premature infants.
Premature birth, spina bifida, congenital neurological or metabolic disorders, heart disease, often associated with poor vascularization, decreased sensation, friction of skin against bone and shear of skin and bone sliding across one another, and malnutrition 6 increase the risk of developing a PI. The Braden Q and Braden QD Scales are the most commonly used instrument to predict PI risk in paediatric patients, 7 although a recent Cochrane review 8 did not find enough reliable evidence from the published studies to suggest that the use of structured and systematic pressure ulcer risk assessment tools reduces the incidence, or severity of PI's.
The reported data on the incidence and prevalence of these lesions are not uniform. Compared with adults, paediatric patients require special consideration, protocols, guidelines, and standardized approaches to PI prevention. Nutritional support and pressure redistribution appear to be of uppermost importance. 11 The guidelines, regularly published by the National Pressure Advisory Panel white paper, encourage the adoption of standardized efforts of interprofessional teams to successfully prevent and treat PIs in paediatric patients. 12 In an intensive care unit, the hospital-acquired PI rate decreased from 30% to 0% as a consequence of the nurses' dedication. In children, most of the pressure ulcers heal spontaneously or with medical help or minimal surgical intervention. 13 However, a minority of ulcers that is refractory to non-operative management or is too severe at presentation (NPUAP Stage 3 or 4) will be candidates for surgery. 14 An accurate search of the literature revealed only two articles reporting on the surgical treatment of PIs in children. 14,15 We report here our experience with a retrospectively evaluated series of paediatric patients who underwent surgical treatment of PIs.

| METHODS
We reviewed the records of 18 patients who underwent flap reconstruction for pressure injuries from 2007 to 2017 at four European Plastic Surgery Departments. The principles outlined in the Declaration of Helsinki have been followed. Clinical data of patients were collected retrospectively and included age, anatomical site, comorbidities, PI stage, medical and surgical treatment, recurrence and other complications.

| Surgical procedure
The principles of surgical treatment of refractory or severe pressure injuries are well described for the adult population 16 and were followed also in our paediatric patients. were removed if nonviable or infected; otherwise, they were reduced in volume and modelled in shape with scalpels or burrs.
If the cause of the pressure lesion was a medical device or other foreign material, we considered it contaminated, because exposed and, if possible, 17 we removed it. After debridement, the defect was reassessed to evaluate and choose the available reconstructive options.
Negative pressure wound-therapy was sometimes used, to prepare the wound bed, reducing bacterial contamination, removing secretions, promoting granulation, and reducing the size of the defect. 18 2.2 | Several flaps were used for reconstruction In most cases, we used a pedicled flap, and only rarely microsurgical free flaps.
A pedicled flap is a portion of tissue that maintains its vascular supply by preservation of the vessels entering and exiting the flap and that are called pedicle of the flap. When a pedicled flap is harvested from the area surrounding the defect to be covered, it is called local flap, while if it is harvested at some distance from the defect that it is reached by means of a longer pedicle, it is called regional flap. In our study, in most cases local flaps were sufficient to obtain a safe and durable coverage, regional flaps being seldom necessary. A microsurgical flap, very rarely used in our study, cannot reach the defect by means of a pedicle because it is harvested too far from it. Its vessels are therefore divided, the flap is transferred into the defect and the artery and vein are anastomosed with microsurgical technique to an artery and vein close to the defect. Details on the patients are reported in Table 1.
Eight patients were wheelchair-dependent, and 12 had sensory impairment at the ulcer site. One patient developed a PI during the hospital stay, following abdominal surgery under general anaesthesia for peritonitis.

| Clinical cases
We describe five cases illustrative of treatment in different body areas, listing reconstructive options alternative to our choice.  Wound healing was uneventful and he was discharged after an intensive rehabilitation program. Regular follow up as an outpatient showed no recurrence until 9 years postoperatively, when a Stage 2 PI recurrence, that was treated conservatively, developed on the right side.

| Recurrences
During follow-up lasting 19 months to 13 years, two of our patients (Cases 12 and 13) developed a recurrence, while Cases 2 and 10 developed new injuries in a different anatomical site. (Table 1).  19,20 After debridement, soft tissue reconstruction is safe, even over a contaminated wound. 21 Several surgical techniques have been proposed, including direct closure and skin grafting (rarely indicated) and, more importantly, local, regional, and microsurgical free flaps. 12,13,18,22,23 Although reconstructive techniques used in the paediatric population do not differ significantly from the ones used in the adult, the different characteristics of soft tissues in children, must be considered.
In children, the subcutaneous tissues are firmer and therefore more difficult to mobilize than in the elderly, while skin and dermis are more elastic. 24 In children, the greater softness and elasticity of the skin and dermis are of help when planning and harvesting a flap for reconstruction, allowing smaller incisions and possibly reducing wound tension. In addition, the vessels are generally healthy, and skin perfusion richer, facilitating the success of regional or free flaps. 25 In treating PI, it is important to use a single flap, planned in such a way as not to interfere with the need for future flaps, especially in chil- The possibility to reuse these flaps in case of PI recurrence has been described. 23 Therefore, due to their advantages, 28 we used pedicled perforator flaps, in different anatomical sites, in Cases 5, 11,12, 14 and 15.
As discussed by Rethlefsen, 29 foot pressure injuries develop in approximately 10% of paediatric patients suffering from spina bifida.
In our study, we treated two such patients with different flaps. In one case with a dorsalis pedis (Case 2) and in one (Case 9) with a free antero lateral thigh (ALT) flap.
The microsurgical ALT flap was chosen because it is considered the best option for lower limb reconstruction in children 30 being reliable, having a relatively thick dermis and the advantage that the donor site can be hidden. Local flaps from weight-bearing surfaces of the same foot were not considered necessary in this case because the patient was not ambulatory, and were avoided to preserve the area in case of new or recurrent PIs.
According to the literature, medical devices are frequently (38.5%-90%) involved in the aetiology of PIs (now specifically called medical device-related PIs) and affected patients are usually younger. In their presence, prevention strategies seem to be particularly important. 15 Seven cases of PIs with exposed medical devices were included in our study. The devices were osteosynthesis material in Cases 1, 14 and Although the recurrence rate of PIs is known to be high in adults, the few data reported in children are not uniform. Singh et al. 15 reported an overall PI recurrence rate of 5% (one of 20 PIs) while in Firriolo's series 14 there was a 42% recurrence rate in ulceration after flap reconstruction, that correlated with a preoperative history of noncompliance with conservative therapy. (Table 2).
Of our 18 patients followed for up to 13 years, two developed a recurrence (Cases 12 and 13) and two patients (Cases 2 and 10) developed new injuries in a different anatomical site and needed to be re-treated.
Contrary to Firriolo's study, 14 where wheelchairs and other equipment for many of the patients were inadequate and in bad condition, and medical care was inconsistent because of self-reported insurance coverage limitations, in our countries, the public health systems supply equipment and free medical follow-up.

| CONCLUSIONS
Flap reconstruction is usually beneficial for the treatment of PIs in the paediatric patients in whom conservative therapy was not sufficient.
However, when surgical repair is necessary. We found in our multicentre retrospective study that long-term success could be achieved with accurate debridement, tailored reconstructive surgery and prevention of new injuries. In our experience, the prevalence of recurrence was lower than previously reported.