DOI: https://doi.org/10.21203/rs.3.rs-2832146/v1
Objective: To investigate the feasibility and effectiveness of free ALTP flap in the repairment of the large head soft-tissue defect after electric shock injury.
Methods: In this study, 25 patients underwent the reconstruction to repair the defect of the head by ALTP, including 18 males and 7 females (mean age:43 years; ranged 20 to 53 years). The etiologies of all patients were electric shock. The location of the defects involved 11 occipitalia,6 tempus,3 forehead and 5 crown, while the dimension of the defects ranged 7*5 to 21*10 cm2(mean 18.5*9.5 cm2).
Results: 25 patients were successfully treated by ALTP. Reconstructions were performed at the second stage in all cases, and all flaps survived completely. The donor sites were closed primarily in nearly all cases with an exception of 5 cases, which were covered with skin-grafting. The Pain Score was from 0 to 45 points with an average of 20 points. The score of Vancouver Scar Scale of donor sites was from 2 to 5 points with an average of 3.4 points. All flaps were followed-up for an average of 16 months (ranged from 6 to 24 months). No significant effect on quadriceps muscle strength and knee movement. Most cases showed satisfactory outcomes.
Conclusion: The use of free ALTP for the repairment of large head defects after electroshock injury is worthy of clinical promotion and application because of its strong resistance to infection, high repair fit and rapid postoperative recovery.
With the acceleration of industrialization, the incidence of electric shock injury is increasing year by year, in which the incidence of head and neck electric shock injury is second only to the upper limbs and body1. As the human body is a conductor, electric injuries cause burns on the direct contact parts of the limbs first, then lead to delayed necrosis of deep muscles, blood vessels and nerves later2. And Heilbronn et al. found that due to the vascular embolism and rupture, tissue infection, and cell membrane damage, the head electric shock injury is easy to cause extensive necrosis of the scalp layer3. Localized cranial defects and necrosis may even occur to varying degrees. Because of the poor microcirculatory conditions on the wound, the success rate of skin-grafting is low. Generally, local rotation pedicled flap4 was used to repair the defect when the dimension of it was less than 6.0*6.0cm2. For large, irregular defect, a free flap was usually considered to reconstruct it, such as TMF (Trapezius Myocutaneous Flap), LDMF (Latissimus Dorsi Myocutaneous Flap) and DIEP flap (Deep Inferior Epigastric Artery Perforator Flap) etc5.
The bulky appearance and poor hair growth on the head are the disadvantages of adopting these flaps for the reconstruction, which could influence the aesthetics and psychology of the patient. The utilization of an ALTP flap (Anterolateral Thigh Perforator Flap) could be an ideal method to repair large head soft-tissue defect after electroshock injury, because of its appropriate vascular diameter, abundant blood supply, excellent anti-infection ability, good abrasion resistance, adjustable thickness and large resectable area. Hsiao et al.6reported a series of cases in which a flow-through ALTP was used to cover the electrical burn defect on the upper extremity and got a satisfactory result about reconstruction of both the revascularization and soft tissue coverage. On the basis of these points, in our series of study, the ALTP was used to reconstruct the head soft-tissue defect caused by electroshock injury. The specific purpose of this study is to evaluate the efficacy of this approach to reconstruct the head soft-tissue defect after electroshock injury.
The characteristics of the patients are provided in Table 1. From October 2013 to December 2020, 25 patients underwent the reconstruction surgery to repair the defect of the head by ALTP. The etiologies of all patients involved high voltage electric shock and low voltage electric shock. In this study, 25 patients received the reconstruction surgery using the ALTP, including 18 males and 7 females (mean age:43 years; ranged 20 to 53 years). All the patients sustained a head soft-tissue defect with the exposure of the tendon and the skull. The location of the defects involved 11 occipitalia,6 tempus,3 forehead and 5 crown, while the dimension of the defects ranged 7*5 to 21*10 cm2(mean 18.5*9.5 cm2). All the reconstructive surgeries were performed at the second stage after the craniocerebral injury was excluded or cured. This study was approved by the ethical guidelines of the Hospital Ethical Committee of the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University. The protocol was performed in accordance with the ethical standards of the Helsinki Declaration of 1975 and all subsequent revisions. All informed consent was verbally acquired from patients.
| Table 1 | |
|---|---|
| Characteristics of the patients | |
| Items | Value |
| Number of patients | 25 |
| Gender (n) | |
| Male | 18 |
| Female | 7 |
| Age (years) | 43 (ranged, 20 to 53) |
| Location of the defect (n) | |
| Occipitalia | 11 |
| Tempus | 6 |
| Forehead | 3 |
| Crown | 5 |
| Dimension of defects (cm2) | 18.5*9.5 (ranged, 7*5 to 21*10) |
| Complication (n) | |
| Venous congestion | 1 |
Surgical technique
After the admission of the patients, all patients underwent radical emergency debridement, and the defects were covered by a vacuum sealing drainage (VSD). After the defects have formed fresh granulation tissue and the infection has been effectively controlled, flap repair surgeries were performed. The operations were performed under general anesthesia and the patients were placed in a flat position. The defect of skull was repaired by titanium plate. The line between the anterior superior iliac crest and the lateral superior patellar border and the midpoint of the line were marked, and the flap was designed around this area. The distal end of the flap was designed at the midpoint of the calibration, in order to place the flap as close to the proximal thigh as possible and to facilitate the primary closure of the donor area. According to the demands of the repairment, the flap was designed approximately 20% more than the wound. After general anesthesia becomes effective, the medial edge of the flap is first incised, and the flap is lifted laterally along with the broad fascial layer, and the perforators were carefully searched. The vascular trunks were separated retrograde to the lateral femoral muscle along the perforators and the ineffective branches were ligated along the way, and the accompanying veins and nerves were protected. After separating the vascular pedicle to a sufficient length, the rest of the flap edges were incised. Only the lateral femoral artery and its company vein and lateral femoral cutaneous nerve branches were connected to the entire flap. The vessels and the nerves of the flap were ligated and cut according to the desired length of the pedicle after the blood supply to the flap edges was checked to be good. The blood vessels are trimmed under the microscope, and then the flap fat is trimmed according to the fatness of the patient's head. Then the flap was transferred to the defect on the head, the arteries and their company veins were anastomosed to the recipient site respectively. To ensure the patent blood-flow in the veins, at least two or more veins should be anastomosed, and the nerves in the flap should be anastomosed with those in the recipient area as much as possible. After completion of the vascular and nerve anastomosis, the temporary sutures of the flap were removed to ensure that there was no obvious bleeding under the flap, and the position of the flap was adjusted to satisfaction before the flap was loosely sutured and fixed in the recipient area. The donor site was closed primarily or with skin grafting.
Evaluation of outcomes
The assessments were performed by a group of experienced reconstructive surgeons. The scar of the donor site was assessed by the Vancouver Scar Scale7, and the feeling of pain was evaluated by the Pain score (ranged 0-100).
In this study,25 patients were successfully treated by ALTP. Reconstructions were performed at the second stage in all cases, and all flaps survived completely. The donor sites were closed primarily in nearly all cases with an exception of 5 cases, which were covered with skin-grafting. All the donor sites healed uneventfully. All results of the surgery are listed in Table 2. In summary, the dimension of flaps ranged from 8*6 to 21*12. The range of operation time was 5.5 to 9 hours with an average time of 7.5h. The Pain Score was from 0 to 45 points with an average of 20 points. The score of Vancouver Scar Scale of donor sites was from 2 to 5 points with an average of 3.4 points. All flaps were followed-up for an average of 16 months (ranged from 6 to 24 months). These flaps provided mild pigmentation and texture without bulky appearance. All flaps showed a content recovery of sensory. There was linear scar growth around the flaps, and a little hair growth on the flaps. No significant effect on quadriceps muscle strength and knee movement. Most cases showed satisfactory outcomes.
| Table 2 | |
|---|---|
| Results of the surgery | |
| Items | Value |
| Dimension of flaps(cm2) | 19*11 (ranged, 8*6 to 21*12) |
| Operation time(hour) | 7.5 (ranged, 5.5 to 9) |
| Treatment of donor site (n) | |
| Primary closure | 20 |
| Skin-grafting | 5 |
| Pain Score | 20 (ranged, 0 to 45) |
| Vancouver Scar Scale | 3.4 (ranged, 2 to 5) |
| Follow-up time (months) | 16 (ranged, 6 to 24) |
Case report
A 50-year-old male sustained an electric shock injury that caused a large soft-tissue defect on posterior occipital with the exposure of skull (Fig. 1A). The dimension of the defect was 18.5*9.5 cm2 after the completion of repeated radical debridement and the drainage of Vacuum Sealing Drainage (VSD) device. The reconstruction surgery was performed after the fresh granulation tissue was formed on the wound surface. The flap was designed on the right lateral thigh according to the shape and dimension of the defect on the posterior occipital, and the dimension of the flap was 20*10 cm2(Fig. 1B 1C 1D) according to the standard of surgery and the demand of the reconstruction. The descending branch of the lateral femoral circumflex artery and its accompanying veins were anastomosed to the superficial temporal artery and vein respectively (Fig. 1E), and the anastomosis of the cutaneous nerve of the flap and the branches of great auricular nerve was performed at the same time. The position of the flap was adjusted to satisfaction before the flap was loosely sutured and fixed in the posterior occipital (Fig. 1F). The donor site was covered with skin grafting and healed well in one stage (Fig. 1G). The postoperative course was uneventful, and the patient received a 12-month follow-up after the operation (Fig. 1H). The flap showed satisfactory contour, and there was no excessive bulky appearance. There is a small amount of hair growth on the flap, and the recovery of the sensory in the recipient site was satisfactory. The patient’s Pain Score was 10 points, and the Vancouver Scar Scale of donor site was 4 points. No significant effect on quadriceps muscle strength and knee movement.
The damage to the human body from electric shock is mainly direct damage to human cells8 and thermal damage to human tissues and organs from heat generation by the electric resistance of body9. The skin and subcutaneous tissues suffer various degrees of burns, deep tissue (muscles, fat, tendons, etc.) become edematous, and the compression of the nutrient vessels leads to occlusion and ischemic necrosis of the tissues. In addition to scalp necrosis, electrical burns to the head are often accompanied by periosteal and cranial involvement, while brain parenchymal injury is rare, but care should be taken in the diagnosis to exclude10. Since the 1980s, there have been many reports on the application of local scalp flap transfer11, pedicled oblique muscle flap, free greater omentum with skin-grafting12 and free flap13 graft to repair electrical burn wounds with skull necrosis in the head after emergency debridement. In the repair of electrical burns on the head with cranial osteonecrosis, the method of removing all of the necrotic cranial bone or drilling the cranial bone to allow the granulation tissue to grow and then transplanting the skin piece is now less commonly used. And the osteonecrosis in electrical burns can be judged by the color of the bone. Electric shock injury to the head should be concerned not only with the repairment of defect and appearance, but also with restoring the function of the head. For small electrical head burn wounds with skull necrosis or exposure, many reconstructive microsurgeons use early expansion of the scalp flap to cover the defects while avoiding skin-grafting and hair loss14. The ideal repair of electrical burns to the head should include scalp and skull repair as well as hair reconstruction to achieve unity of appearance and function. In this case, free flap is considered a better approach to repair the defect. The representative free flaps are: latissimus dorsi muscle flap, ALTP, rectus abdominis muscle flap, and inferior oblique muscle flap. The constant vascularity, large excisional area, rich blood supply, and ability to resist infection are the advantages of latissimus dorsi muscle flap, but its bulky appearance and the need for postoperative braking increase the difficulty of care. The use of dermal scaffold + skin-grafting technique15 for repairing skull exposure in head defects has also been reported to reduce surgical trauma and is suitable for elderly patients with poor body constitution. However, because the dermis cannot grow hair, hair transplantation is required later for patients with special needs, and due to the technique is expensive, the application of it was limited. Based on safety, economic and postoperative efficacy considerations, the ALTP was preferred to repair the large defects of head after electroshock injury in our study.
Since the report of ALTP by Koshima et al.16 in 1993, it has been widely used in the repair of various parts of the body, and is therefore also known as a "universal flap". And based on the evidence mentioned above, we used the free ALTP to perform the reconstruction of the head defect after electric shock injury. Through the application of this technique in 25 patients, it provides some advantages as mentioned here:1) The descending branch of the lateral femoral circumflex artery is one of the most important branches of the lateral femoral circumflex artery, and it has high reliability of blood supply, stability of position and low anatomical variability as the origin trunk of the flap17. 2) The diameter of the descending branch of the lateral femoral circumflex artery (1.7–2.6 mm) and the diameter of the superficial temporal artery (2.0-3.3 mm), the diameter of the occipital artery (1.4–2.5 mm) and the diameter of the posterior auricular artery (1.2–3.4 mm) basically coincide in size. Therefore, the flap vascular can be well matched to the recipient site and anastomosed easily. 3) The ALTP, which contains broad fascia, has good elasticity and abrasion resistance, and also increases the protection of brain tissue.4) The anterolateral femoral cutaneous nerve can be included and anastomosed with the trabecular cutaneous nerve to make the flap with sensory function. 5) Faced with a large area of soft tissue defect trauma in the head, the expansion flap faces a limited amount of tissue in the donor area. The ALTP can be excised over a large area. The flap can be removed over the 2/3 of the thigh, which is suitable for repairing large soft-tissue defects.6) For electric shock defects, the flap is highly resistant to infection and reduces the risk of long-term non-healing of infected wounds. And we did observe some drawbacks in the use of this method:1) Since there is no hair in the flap area, patients with special requirements for hair are recommended to have a second stage hair transplant to make it more satisfactory. 2) In obese patients, the flap is bulky and often requires surgical thinning.3) Due to the abundant blood supply in the recipient site, it is necessary to anastomose the veins as much as possible to enhance venous drainage.
Several tips can be shared about this study. Firstly, based on the opinion of Khalid et al18,radical and thorough debridement is a key factor influencing flap survival after surgery. Intraoperative attention should be paid to thoroughly remove necrotic tissue from the electroshock wound and remove necrotic cranial bone tissue to prevent contamination and further injury. Secondly, the patient was positioned appropriately after surgery depending on the position of the flap to avoid pressure on the flap vascular pedicle. Next, for occipital flap repair, the postoperative position is prone or lateral, and for the parietal or temporal region, the position is flat or 45° oblique lateral. Last, the flap should be designed as close to the root of the thigh as possible, because if the defect is wide, the donor site may not be closed in one stage, and the pedicled abdominal flap can be chosen to repair the donor site.
The use of free ALTP for the repairment of large head defects after electroshock injury is worthy of clinical promotion and application because of its strong resistance to infection, high repair fit and rapid postoperative recovery.
Ethics approval and consent to participate
This study was approved by the ethical guidelines of the Hospital Ethical Committee of the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University. The protocol was performed in accordance with the ethical standards of the Helsinki Declaration of 1975 and all subsequent revisions. All informed consent was verbally acquired from patients.
Consent for publication
Not applicable.
Availability of data and materials
The datasets generated during the current study are not publicly available due the patient's permission but are available from the corresponding author on reasonable request.
Competing interests
The authors declare no competing interests.
Funding
There is no funding source to disclose.
Authors and Affiliations
Department of orthopedics, Xindu District People’s Hospital, Chengdu,China
Xincheng Tang
Department of orthopedics, The Affiliated Traditional Chinese Medicine Hospital of
Southwest Medical University, LuZhou, China.
Jiayu Li, Tianyu Huang
Author information
Xincheng Tang and Jiayu Li are co-first authors
Tianyu Huang is the corresponding author
Contributions
All authors have intellectually contributed to this manuscript. XC Tang and JY Li wrote the main manuscript text and TY Huang prepared figures and tables. All authors performed the surgeries and reviewed and approved the final manuscript.
Acknowledgements
None.