Overcoming Prolonged Ischemia in Total Scalp Avulsion After Industrial Accident: A Case Report

Introduction

Total scalp avulsion is an uncommon but serious injury commonly occurring in occupational settings involving machinery with rotating parts that cause hair becoming entangled in high-speed machinery [1–4]. Specific prevalence rates are not well-documented, but certain industries, such as agriculture and manufacturing, are more susceptible due to the nature of their equipment [5]. Previously, addressing such injuries faced considerable hurdles, with standard techniques like composite grafting or free flap transfer failing to provide satisfactory visual and practical outcomes [1,6–8]. However, the introduction of microsurgical replantation has transformed treatment procedures, providing better outcomes than alternatives [1–4].

Historically, the acute care of scalp avulsion used crude procedures such as replacing the avulsed scalp with a free graft, which produced poor results in most cases [1,6–8]. The breakthrough came in 1976, when Miller et al pioneered microsurgical procedures that allowed for the successful replantation of partial and whole avulsed scalps via complicated artery and venous anastomoses [1,2].

Despite improvements, postoperative congestion remains a long-term concern, necessitating continued research into strategies to reduce its recurrence. Strategies such as adjusting the vein-to-artery ratio and using adjuvant therapies, such as leeches, have been used to solve this issue [9]. Notably, successful replantation has been accomplished with little vessel anastomoses, demonstrating the importance of vessel vitality in deciding surgical results.

In this report, we present a compelling case of total scalp avulsion in a patient who underwent microvascular replantation, showcasing not only the efficacy of this approach but also revealing a unique postoperative hair growth pattern. This case contributes to the expanding body of evidence supporting microsurgical replantation as the criterion standard treatment for total scalp avulsion, emphasizing its importance in providing the best patient results.

Case Report

A 28-year-old female patient was admitted to the Emergency Department 4 h after complete avulsion of her scalp. Her hair got tangled by moving machinery while she was working without wearing a helmet at a fiber tractor factory, resulting in traumatic scalp avulsion. Within an hour of the accident, she was admitted to a Xuyen A hospital, where the amputated flap was meticulously preserved by insulating it from direct ice exposure using a plastic bag and immersing it in an ice bath for cold storage. Subsequently, the patient was transferred to Cho Ray Hospital for salvage surgery (Figure 1). The avulsed scalp underwent emergency replantation, 7 h after the initial injury.

The patient was oriented and fully responsive, with a blood pressure of 90/60 mmHg, pulse of 90 beats/min, respiration rate of 20 breaths/min, and Glasgow Coma Scale of 15. A computed tomography scan of her cerebrum and facial bones showed no sign of intracranial bleeding or fractures (Figure 2). The patient underwent a neurosurgical evaluation, which revealed no abnormalities, thus the decision was made to proceed with emergency surgery.

Examination in the operating room revealed a complete scalp avulsion injury covering approximately 4% of the total body surface area. The laceration extended horizontally across both eyebrows and bilaterally, with the right side closely adjacent to the auricle and the left side involving half of the left ear, then continued behind the mastoids and completed the avulsion at level of the external occipital protuberance. Both the superficial temporal arteries and veins were intact.

The patient was anesthetized, and meticulous preparation of the scalp ensued, involving cleansing of the scalp using normal saline, followed by removal of debris and foreign objects (Figure 3). To prevent thrombosis, all vessels were heparinized, and a comprehensive revision of the entire scalp circumference was performed. The surgical team first identified the superficial temporal arteries and veins on the scalp (Figure 4). Upon examination, it was determined that the left and right superficial temporal arteries sustained the least damage. Therefore, bilateral anastomosis of the superficial temporal arteries was conducted, first by using a Prolen 8-0 suture, facilitating adequate perfusion within a mere 15 min (Figure 5). Then concomitant veins were anastomosed with bilateral superior temporal veins and posterior auricular veins to alleviate venous congestion and ensure optimal perfusion. In all, 2 arteries and 2 veins (left post auricular vein and superficial temporal vein) were anastomosed. Occipital vessels that fit properly for anastomosis could not be located. To manage postoperative drainage effectively, suction drainages were placed under the occipital part of the scalp. Total ischemia time in this case was 4.5 h.

The patient had a hospital stay duration of 20 days. Postoperatively, the patient received levofloxacin 750 g per day for 14 days, and enoxaparin 400 IU subcutaneously for 7 days. Recovery was uneventful during 3 days of hospital stay (Figure 6). Although the majority of the scalp tissue survived, a section of partial skin necrosis measuring 4.0×7.0 cm2 developed in the right occipital region. Therefore, we debrided the lesion and reconstructed with a split skin graft on day 10 after the operation, leading to complete patient recovery.

Approximately 5 days postoperatively, the patient began experiencing hair regrowth (Figure 7), albeit transient hair loss occurred until day 18, after which complete regrowth was observed. Despite successful microvascular anastomosis of 2 superficial temporal arteries and 2 veins, which significantly improved perfusion, compared with the baseline condition of 1 high inflow and 1 outflow vessel in flap reperfusion, nutritional deficiencies impacting hair follicles were noted.

At the 1-month follow-up, satisfactory cosmetic outcomes were achieved, and the patient was satisfied with her appearance. Furthermore, the site healed effectively, and strong hair growth was noted within 5 days of surgery, with significant improvement noticed over the right head. The length of her hair was 28 mm. Notably, the patient showed a difference in hair development patterns between the right and left temporal areas, with greater growth on the right side (Figures 8, 9). At the 4.5-month follow up, the hair growth was in uniform follicular distribution across the entire scalp, and the patient expressed satisfaction with the aesthetic outcome (Figure 9).

Discussion

There are 5 layers of the human scalp: skin, connective tissue, epicranial aponeurosis, loose areolar tissue, and pericranium. The first 3 layers are tightly connected to form a dense unique structure consisting of hair follicles and neurovascular status that is capable of gliding over the loose areolar tissue, which is situated above the pericranium, a layer firmly attached to the skull (Figure 8). In scalp avulsion, the separation usually happens at the loose areolar tissue layer, which has few blood vessels. Microsurgical replantation is the most effective way to treat full-thickness injuries caused by complete scalp avulsion. Restoration of whole-scalp defects after accidental avulsion presents a significant challenge, requiring cosmetic finesse and functional reconstruction to maintain natural hair patterns and lines. The goal of preservation is to increase the survival of the flap and to reduce postoperative infection. Before evaluating the flap, surgeons must rule out other threading risks, including hypovolemic shock due to trauma-induced blood loss and any cranial injuries, before proceeding with operative interventions. When the patient is in stable condition, reconstruction methods depend on several factors, namely size, location, the condition of periosteum, the quality of tissue that surrounding the scalp, any hair loss, hair line, and any existing medical conditions of the patient. Prior to the introduction of anastomosis in treatment, the sole method available was skin grafting, which often resulted in permanent baldness for the patient [10]. In our case, vital signs remained within normal limits, and computed tomography revealed no evidence of intracranial hemorrhage or injury in the cranial periosteum. Grafting bone lacking periosteum is rarely successful in certain cases, although some authors suggest applying a skin graft directly onto raw bone in small areas as a biological dressing, leading to secondary healing through granulation and epithelialization [11]. However, for larger periosteal defects, treatment can involve several sessions of skull drilling. In this context, wet dressing or negative pressure therapy can be used as combination therapies. Once the granulation tissue has developed properly, a skin graft is then applied to the wound [12].

Sirimaharaj [13] described some basic knowledge of amputated flaps. First, the imperative of undertaking microvascular replantation remains paramount, even in prolonged ischemic periods. In our case, the flap was anastomosed after 7 h, but some authors have reported that a scalp can tolerate up to 17 h of warm ischemia and up to 24 h of cold ischemia, while still being successfully anastomosed [6]. Second, meticulous attention to detail during the cleansing and priming of the scalp serves as a pivotal measure to preclude the inadvertent entrapment of hair follicles and debris within the flap’s undersurface. Shaving flap hair before any surgical procedures can help to facilitate the assesssment of the vascular condition, which plays a vital role on the success of replatation, evaluation of wound healing, and change of dresssings [11]. Third, in emphasizing the pivotal role of arterial supply, it is clear that singular arterial conduits suffice for efficacious reperfusion; therefore, comprehensive mobilization is advocated, to obviate reliance on venous grafting. In fact, surgeons should always consider proceeding with vascular anastomosis if the blood vessel is not damaged. Due to the avulsion mechanism, the vessels usually have complete transaction injuries, thus making anastomosis is easier than with other injury mechanisms. Debridement and heparin are essential to address intimal clots caused by prolonged ischemic time. Looking for other impending problems, such as friable vessel walls or vasospasm, is crucial to increase the survival and success rate. A larger number of anastomosed vessels increases the chances of successful replantation. Also, many authors have published their experiences in successful scalp avulsions with a single arterial anastomosis, because of the strong collateral flow in the scalp [7]. The key to success is the availability of a reliable vein for drainage in microvascular replantation. The superficial temporal vein is typically the preferred recipient vessel for the replantation of avulsed scalp tissue in the temporal region. However, the superficial temporal vein is not always vital for anastomosis, and the deep temporal vein can be used. In our case, we used 1 superficial temporal vein on the left side and 1 posterior auricular vein on the right side. The superficial temporal vein is usually the first choice for scalp replantation, and in the descending order of choices, the supraorbital and occipital artery could be used when the superficial temporal vein is unavailable [8]. Single vein anastomosis plays a vital role in success because most of the failure of reimplantation is because of venous congestion. In our case, despite our efforts to locate both superficial temporal veins on both sides, the left superficial temporal vein was damaged and thus ineligible for anastomosis. Therefore, we used the posterior auricular vein to increase the survival rate of the replantation.

The posterior auricular artery and superficial temporal artery are the main arteries that supply blood to the external auricular. In our case, there was no damage to the posterior auricular artery. After successful anastomosis, we tested for bleeding at the edge of the partial auricular segment in the scapular flap. This provided the evidence that confirmed our flap was fully perfused. We proceeded to suture this area in correct orientation, based on anatomical considerations. The result was excellent and structurally restored.

However, in the challenging case of performing vascular anastomosis, Cen et al stated that a high-quality free avulsed scalp can be thinned using a specific drum-type peeling machine to produce an appropriate-thickness skin graft. Then, this graft can achieve complete engraftment, followed by the care of the postoperative wound by using sterile dressing or negative pressure treatment [12]. Kalra et al also suggested that free tissue transfer is a reliable and safe way to reconstruct total scalp defects. Moreover, the combination of using a muscle-only latissimus dorsi flap, the serratus anterior and splite-thickness skin graft for large defects scalp reconstructions has been successful in certain patients with stable soft tissue coverage, low rate of complications, and good cosmetic results [9]. Also, Huang et al [14] used indocyanine green angiography to assess tissue perfusion in scalp avulsion cases; however, we did not have a chance to use this technique in our patient.

In 1964, Horovitz first documented a case of scalp avulsion, in which the reattached scalp underwent primary closure without microvascular anastomosis [15]. The pioneering successful replantation using microvascular techniques was reported by Miller et al [2]. Given the infrequent occurrence of total scalp avulsions, no universally accepted treatment protocol has been established. However, Wechselberger et al proposed an algorithm for managing such cases, advocating for replantation surgery whenever feasible [16]. We concur with the necessity of pursuing reimplantation surgery, even in challenging scenarios, such as the present case. The optimal window for surgical intervention is within the initial 6 h, as success rates tend to diminish with prolonged delays. Despite the patient’s delayed presentation exceeding 6 h, the well-preserved scalp remained viable, justifying our decision to proceed with replantation surgery.

Early literature on microsurgical replantation of avulsed scalp often described extensive vascular anastomoses. Miller et al notably used 5 veins and both superficial temporal arteries [2,17]. However, recent studies have demonstrated successful reimplantation with fewer vascular connections, such as 1 artery and 1 or 2 veins, aligning with our surgical approach [10,16]. In this instance, we performed 1 arterial anastomosis and 2 venous anastomoses.

Upon reviewing the available literature, we assert that this case represents one of the largest scalp avulsions successfully replanted. Neurological recovery is anticipated within the initial 6 months postoperatively.

Following scalp surgery, postoperative care requires rigorous monitoring and frequent dressing changes to achieve optimal healing and prevent complications. Close surveillance is required due to the potential for congestion and necrosis in various locations of the scalp following surgery. The common complications to be aware of after discharge are local scalp swelling, scar enlargement in the suture, changes in the hairline, hair loss, tingling or numbness, and cold tolerance abnormality [18–21].

This emphasizes the importance of ongoing surveillance to detect and treat any vascular impairment or tissue necrosis, as these factors might have a substantial impact on the outcome of a replantation operation. All patients who underwent surgery were subjected to follow-up for a period of 6 months to 3 years.

In our patient, the scalp maintained adequately perfusion over the 20-day hospitalization period. All grafts survived, resulting in an uneventful recovery for the patient. Upon the removal of dressings after 5 days, the normal healing process became evident. After 20 days, the patient was discharged from the hospital and instructed to schedule a follow-up appointment in 1 month.

Given that the artery anastomosis was located on the other side of the flap, it was assumed that the reduced hair growth in this particular region was due to a slight residual ischemia. Compared with other cell types, hair follicles are more prone to ischemia and subsequent release of inflammatory factors. On days 7 and 8 after surgery, there was a decrease in frontal sensory, and sensory recovery from the frontal to parietal regions was evident 20 days after surgery. Furthermore, the return of frontal muscle contraction 20 days after surgery implied favorable progress in motor function. Ultimately, the process produced a very good overall aesthetic outcome. The patient reported no discomfort in the locations where skin was grafted.

There are several challenges and limitations presented in our case. This was one of the largest scalp avulsion injuries asscociated with prolonged ischemic time. Therefore, microsurgery was the priority decision and it had to be a swift decision and preparation. The surgeon’s technique and experience in performing microsurgical anastomosis plays a vital role in reducing operation time and restoring perfusion. Additionally, the appropriate preservation of the amputated flap significantly contributed to the result. During the procedure, the left superior temporal vein was damaged, requiring us to choose the posterior vein as a reliable vein to venous reanastomosis. Despite these challenges, the outcome was well accepted.

Conclusions

Long-term follow-up yielded favorable results in terms of hair growth, sensory recovery, and motor function, demonstrating effective regeneration of scalp tissue and nerve function despite initial challenges. Regular monitoring and follow-up examinations are required to assess the long-term results and address any outstanding difficulties. Overall, a complete approach to care, together with ongoing research initiatives, is critical for maximizing results in scalp surgery. Preventative measures, such as wearing helmets, are critical in preventing scalp avulsion injuries, particularly in occupational settings [22]. Because of the rare prevalence of this type of accident, further work needs to be done in order to find the most effective approaches for optimizing care and outcomes for patients with scalp avulsion injuries.