Tissue Expander for Pediatric Scalp Reconstruction Complicated by Fungal Infection With Aspergillus terreus.

CASE REPORT Tissue Expander for Pediatric Scalp Reconstruction Complicated by Fungal Infection With Aspergillus terreus Shelley R Edwards, BS1; Katherine C Benedict, MD1; John Sullivan, MD1; Roberto Santos, MD2; Ian Hoppe, MD1 Keywords Tissue Expansion Fungal Infection Antifungal February 2023 ISSN 1937-5719 Index ePlasty 2023;23:e9 Abstract Background. Tissue expansion is an effective option for soft tissue reconstruction of the scalp in the pediatric population. Unfortunately, this approach carries a high risk of such complications as infection and expander exposure. While bacterial infection of alloplastic materials is most frequent, when fungal infections occur, the outcomes can be devastating. Purpose. To inform the management of fungal tissue expander infections, this report describes a case of expander-based scalp reconstruction complicated by Aspergillus terreus infection in a pediatric patient. Methods. A patient who had blunt-force head trauma presented with soft tissue injury and depressed skull fracture requiring emergent craniectomy. After stabilization, a paucity of soft tissue coverage required further surgical intervention before reconstructive cranioplasty. Six months after her injury, two remote port subgaleal tissue expanders were placed. Subsequently, purulent drainage developed from the surgical incision. Results. Infection resulted in expander exposure requiring device removal and treatment with clindamycin and ceftazidime while awaiting culture results. Intraoperative cultures were positive for Aspergillus terreus and methicillin-sensitive Staphylococcus aureus, for which she received systemic voriconazole for 23 days and cephalexin for 10 days. Conclusions. Though tissue expansion remains a viable reconstructive option, fungal infection can be disastrous, requiring systemic antifungal therapy, surgical debridement, and expander removal. Introduction Tissue expansion is a valuable tool for reconstruction of large scalp defects while allowing for restoration of hair in the involved region. Despite this significant benefit, the procedure remains time and energy-intensive for both the patient and the surgeon due to the need for frequent clinic visits for expansion and a moderately high complication rate for the procedure. Prior studies have had conflicting data regarding complication rates of expander placement, ranging from 4% to 63%. However, a large meta-analysis showed a mean complication rate of 17.4%, with the most common complication rate after tissue expander placement being implant exposure followed by infection.1,2Risk factors for the development of expander infection include large expander size (200-400 mL), disease duration ≤1 year before expander placement, and hematoma evacuation after placement.3 Presence of infection often leads to a prolonged course of surgical management due to the need for antibiotics and surgical intervention, including expander debridement, replacement, or removal. A recent study analyzing tissue expander infections showed a 9.5% removal rate after expander infection due to recalcitrant infection.3 Tissue expander infections are predominantly due to bacterial pathogens; in 1 report, Staphylococcus aureus was found in three-quarters of exudate samples cultured.4 In contrast, infection of fungal origin is rarely reported.5-7 Prolonged treatment courses, common to tissue expansion-based reconstructive cases, provide numerous opportunities for pathogen introduction. Chlorohexidine solutions to prep skin before outpatient expansion lack sufficient fungicidal activity. Albeit more effective, alcohol and iodine-based solutions lack full sporicidal efficacy.5 Furthermore, recent literature suggests that antibiotic treatment of bacterial infections may contribute to subsequent fungal infection due to the hyphae-inducing properties of peptidoglycan released from dying bacteria.8 Therefore, a postoperative course complicated by bacterial infection may contribute to expander infection with atypical organisms. Unfortunately, the treatment of fungal tissue expander infections is currently complicated by the relative lack of literature detailing appropriate management strategies, but implant removal and cultures should be considered paramount. The present report informs management strategies for the treatment of fungal tissue expander infections in the pediatric population. Methods This report presents the case of a 12-year-old female patient with a history of asthma and hypothyroidism who was undergoing craniofacial reconstruction following accidental blunt force head trauma. Initial evaluation at an outside facility revealed multiple severe, depressed, calvarial fractures, including the frontal sinus and multiple facial fractures, and atlanto-occipital disassociation injury. Shortly after her injury, she required an emergent craniectomy and was treated with a 10-day course of ampicillin-sulbactam prophylaxis and a 7-day course of erythromycin eye drops due to multiple facial fractures. Despite antibiotic prophylaxis, she subsequently suffered multiple infections, including Escherichia coli infection of the scalp wound, which was treated with ceftriaxone, and a subsequent soft tissue infection with a rare staphylococcal species. Figure 1. Clinical image showing visible deterioration of scalp wound. Obtained following transfer to tertiary care facility. Cerebrospinal fluid (CSF) cultures taken approximately 2 months after the injury revealed Candida infection requiring amphotericin B and fluconazole treatment. Ultimately, she was transferred to a tertiary care hospital for management and reconstruction due to visible deterioration of the scalp wound (Figure 1) and ongoing complex care requirements. Following transfer, she required wound debridement and obliteration of the frontal sinus before large adjacent tissue transfer to gain vascularized coverage of the previous craniectomy site. The soft tissue defect was successfully closed with local flap advancement (Figure 2). Figure 2. Clinical image captured following soft tissue defect closure with large local flap advancement. Approximately 6 months after her initial injury, 2 remote port subgaleal tissue expanders were placed to facilitate later bony reconstruction. In consideration of her numerous postinjury infections, she was discharged on oral cephalexin and topical bacitracin ointment. Initially, tissue expansion proceeded without incident until threatened exposure of the anterior expander necessitated a repeat operation to reestablish expander coverage. One month postoperatively, she was prescribed amoxicillin/clavulanic acid due to periorbital swelling noted during an outpatient expansion appointment. One week later, she returned to the clinic reporting a 3-day history of purulent drainage from her incision sites (Figure 3) with increased incisional pain. She underwent expander removal, at which time copious purulence was encountered throughout the expander (...truncated)