Superficial Circumflex Iliac Artery Perforator Flap with Bilobed Design for the Donor Defect after Wrap‐Around Flap Transfer Reconstruction

Abstract

Objective

The repair of great toe donor site defect after wrap‐around flap transfer is still controversial. The bilobed superficial circumflex iliac artery perforator (SCIP) flap can improve the aesthetics of the great toe while maintaining its function. Thus, this study aimed to report our experience in the reconstruction of big toe donor site defects with the bilobed SCIP flap and describe the clinical outcomes.

Methods

This study was a retrospective trial. From May 2017 to May 2020, 13 patients with the great toe donor site defect after wrap‐around flap transfer were included in this study. The average age of the patients was 44 years (range, 23–60 years). All patients received free bilobed SCIP flaps to reconstruct the donor site defect of the great toe. Relevant clinical features were recorded preoperatively. The thickness and design of the SCIP flap and the harvesting layer of the flap were measured during the operation. The survival rate of flaps and skin grafts and the incidence of infection were recorded after operation. At follow‐up, donor site complications and postoperative outcomes were evaluated.

Results

In all cases, the SCIP flap covering the donor site of the great toe survived. All patients were followed up for 24–40 months (mean, 30.5 months). The average thickness of the SCIP flap was 0.38cm. All SCIP flaps were harvested from the superficial fascial layer except for three obese patients. The thin SCIP flap had a bilobed design with no further defatting procedures. Postoperatively, the great toe‐nail flap donor site regained its original appearance without bloating or flap necrosis. There was a hidden linear scar in the groin donor site, which did not affect hip joint movement. All patients were satisfied with the aesthetics of the surgical site.

Conclusion

The SCIP flap with bilobed design for repairing the donor defect of the great toe after wrap‐around flap transfer is a kind of surgical method with excellent contour, meeting the requirements of function and aesthetics.

Schematic diagram illustrating the SCIP flap with bilobed design to cover the nail area and the base of the great toe.

Introduction

The wrap‐around flap transfer reconstruction is an available method for thumb reconstruction after traumatic amputation. ¹ , ² , ³ However, the donor site defect of the great toenail after wrap‐around flap transfer is also an important problem that cannot be ignored. ⁴ To minimize morbidity, the donor site defects are mostly repaired with skin grafting, local pedicle flaps, and free flaps. ⁵ , ⁶ However, these methods are not without drawbacks.

The traditional method of restoration of the donor area is one‐stage or two‐stage skin grafting. Although free skin grafting is a simple and convenient surgical method for repairing skin surface defects, there are complications such as poor survival rate of skin grafting, poor wear resistance, and easy formation of ulcers, which seriously affect the rehabilitation and quality of life of patients. ⁷ , ⁸ Artificial dermis combined with VSD has also been used to repair the donor site of the great toe, but it is only suitable for repairing small area defects, not large ones. ⁹ Li et al. used artificial dermis combined with autogenous blade thick skin to repair hand and foot skin and soft tissue, but the artificial dermis is susceptible to infection, which is not conducive to wound recovery, and there are still many limitations. ¹⁰ Many scholars further use the pedicled island flap to repair the toe donor area. According to reports, Özay Özkaya et al. achieved satisfactory results in repairing the defect of the big toe with the first dorsal metatarsal artery island flap. Island flaps have similar anatomical features to the recipient site and do not require the sacrifice of great vessels. However, the number of tissues available for partial pedicle flaps is limited. Most pedicled flaps also require further skin grafting, which increases surgical manipulation and donor site injury, as well as risks and complications. ¹¹ , ¹²

Free flaps are easy to obtain and can be designed according to the size of the donor defect. Using free flaps to repair the donor site can avoid increasing foot damage, but the commonly used free flaps are thicker. In addition, the appearance of the repaired big toe is bloated, which will affect the patient's walking function, and often requires multiple thinning operations, which increases the burden on the patient and affects the surgical effect and satisfaction. ¹³ , ¹⁴ According to reports, Liu et al. used the dorsal intermediate neurocutaneous flap to reconstruct the distal foot skin defect and achieved good patient satisfaction. However, it still does not solve the toe deformity and pain caused by ordinary skin flaps, and the skin flap cannot effectively cover the entire toe. ¹⁵ The free superficial iliac artery perforator (SCIP) flap uses the superficial iliac artery as the pedicle. Although the diameter of this vessel is relatively small and the anatomy is not constant, the flap has the advantage of being soft and having a large area to be cut. ¹⁶ , ¹⁷ The groin donor area can be sutured directly after surgery, leaving only a linear scar, with little impact on the appearance and function of the groin donor area and a hidden scar. However, with this SCIP flap covering the donor defect, the great toe is still very swollen. Consequently, we recommend a new approach which is to use a thin SCIP flap with a bilobed design to cover the nail area and the base of the great toe to restore its original contour. ¹⁸

Herein we report a case series of the repair of great toe donor site defects after rotational flap transfer with a bilobed SCIP flap. The objectives of this study were: (i) evaluate the feasibility and reliability of this new design; (ii) list the technical details of the surgery; (iii) analyze the advantages of this method and identify its limitations. ¹⁹

Patient and Methods

Inclusion and Exclusion Criteria

The inclusion criteria of this study were as follows: (1) patients with thumb skin defect, tendon, or bone exposure requiring thumb reconstruction; (2) patients with thumb defect greater than grade III; (3) patients receiving SCIP flap reconstruction for great toe donor site defect; (4) patients with at least 24 months of follow‐up.

Exclusion criteria were as follows: (1) severe brain or other organ damage; (2) severe limb damage (affecting blood supply); (3) psychiatric disorders, coagulation disorder, diabetes, or smoking history; (4) lost clinical data.

Patient

Between May 2017 and May 2020, 13 patients with donor defects of the great toe were reconstructed with SCIP flaps. There were 10 male and three female patients with an average age of 44 years (range, 23–60 years). The flaps are taken from the groin and are bilobed flaps. The flaps were elevated from the deep fascia in three cases and elevated from the superficial fascia in 10 cases. The average thickness of the flap was 0.38 cm (0.3–0.6 cm), and the donor site of the groin was primarily sutured. Data on BMI, flap thickness, flap design, harvest layer, and complications of the donor site of the great toe were recorded in Table.1.

TABLE 1.

Patients' demographic data

Case	Sex/Age	BMI(kg/m2)	The thickness of the SCIP, cm	Flap Design	Harvest layer	Complication
1	M/27	22.3	0.4	Bilobed flap	Superficial fascia	None
2	M/57	26.5	0.3	Bilobed flap	Superficial fascia	None
3	M/23	19.1	0.3	Bilobed flap	Superficial fascia	None
4	F/52	29.3	0.4	Bilobed flap	Deep fascia	None
5	M/36	20.3	0.3	Bilobed flap	Superficial fascia	None
6	M/49	32.5	0.6	Bilobed flap	Deep fascia	Hyperpigmentation
7	M/60	24.8	0.3	Bilobed flap	Superficial fascia	None
8	M/34	19.3	0.3	Bilobed flap	Superficial fascia	None
9	M/46	26.5	0.5	Bilobed flap	Superficial fascia	None
10	F/49	29.5	0.3	Bilobed flap	Superficial fascia	None
11	M/40	31.3	0.5	Bilobed flap	Deep fascia	Hyperpigmentation
12	M/51	23.9	0.4	Bilobed flap	Superficial fascia	None
13	F/56	28.4	0.4	Bilobed flap	Superficial fascia	None

This study was implemented with the approval of the Ethics Committee of the affiliated Nanhua Hospital (approval No. 2017‐1LY‐34). All procedures involving human participants were in accordance with National Research Committee and with the 1964 Helsinki Declaration and its later amendments. Informed consent was obtained from all participants included in the study.

Preoperative Examination

The superficial circumflex iliac artery (SCIA) trunk, deep branch, superficial branch, and its main penetrators were detected by computed tomographic angiography (CTA), color Doppler ultrasound before operation. The source artery emanation point was traced and marked.

Surgical Procedure

After the great toe wrap‐around flap was excised and moved to the reconstructed finger recipient area for vascular‐neural anastomosis, the other group repaired the donor area of the foot. The penetration point of the SCIA was used as the central point of the flap, with the pulsation point of the femoral artery 2.5 cm below the inguinal ligament and the anterior superior iliac spine (ASIS) as the axis line of the flap. The SCIP flap was designed according to the size and shape of the defect area, and the flap was about 0.5–1 cm larger than the defect area to avoid flap shrinking after harvest. The skin and subcutaneous adipose tissue of the pedicle were first incised, and the superficial and deep branches of SCIA and their main penetrators were explored.

The SCIP flap was dissected from the superficial fascial layer between the deep and superficial fat layers when preparing an ultra‐thin flap. When the subcutaneous fat was thick and penetrators were difficult to identify with the naked eye in the superficial fascial layer, the flap was dissected from the deep fascial layer. The penetrators were carefully separated, and the main penetrators were protected into the flap, and then the flap and pedicle were dissected retrograde to the femoral artery sheath. When the common superficial subcutaneous veins in the groin area had the refluxing effect, they also should be dissected to the appropriate length for anastomosis. Before the pedicle was severed, the superficial fascia was dissected sharply under the microscope to separate the penetrator from the superficial fascia to the skin entry point, protecting the penetrator and the pedicle. The fat layer of the flap was thinned uniformly and sufficiently to preserve approximately 0.1 cm of fat particles to create a thin flap for the donor area. After confirming the reliable blood flow of the thinned flap, the pedicle was severed and the bilobed SCIP flap was sutured to the nail area and the base of the great toe respectively (Figure 1). The superficial circumflex iliac artery was anastomosed to the first dorsal metatarsal artery, and the superficial flap vein was anastomosed to the subcutaneous vein of the foot, with drainage placed under the flap. The groin donor area was directly closed.

FIG. 1.

Schematic diagram illustrating the SCIP flap with bilobed design to cover the nail area and the base of the great toe, respectively

Postoperative Management

Avoid any medications that may constrict blood vessels after surgery. The draining graft was removed 24–48 h after surgery. The dressing was changed every 2 days, and the flap survival, wound healing, and infection were observed. The sutures were removed 2 weeks after the operation.

Statistical Analysis

Statistical analyses were performed using the commercial software package SPSS 23.0 (IBM Corporation, Chicago, Illinois, USA). Data are reported as numbers and percentages for categorical variables, and continuous variables are presented as means and standard deviations (SD). Statistical significance was set at p < 0.05.

Result

The surgery was performed by two groups of surgeons simultaneously, and the mean time from flap removal to grafting to the big toe donor site was 3.6 h (range, 3–4 h), and the mean time to complete the entire procedure was 7.2 h (range, 6–8 h). All 13 cases of SCIP flaps were successfully harvested and survived. The average thickness of the thin SCIP flaps was 0.38 cm (range, 0.3–0.6 cm). The average follow‐up time was 30.5 months (range, 24 to 40 months). Most thin SCIP flap repaired areas had good coverage and a thin and soft shape, without ulceration, and generally did not require further flap revision or defatting procedures. Except for two cases, the SCIP flap had hyperpigmentation, and the color was different from the donor site affecting the appearance. No other complications occurred. There was no infection or skin necrosis after the incision and the groin donor site was primary sutured. There was a hidden linear scar in the donor site after surgery, which did not affect hip joint movement.

Classic Case Reports

Case 1

A 36‐year‐old man was injured by machine crush causing avulsion of the skin and soft tissues of his left hand. In the emergency department, we performed debridement of the left hand, partial amputation of the middle and distal part of fingers, and repair of the palm and dorsal of the hand by flaps for the patient. At 6 weeks postoperatively, the patient requested the reconstruction of the left index finger. The left index finger was repaired by the great toenail flap. The donor site of the great toe was repaired by the thin SCIP flap, and the SCIP flap was designed with bilobed according to the position of the perforator before the operation. The groin donor site was primary sutured. The reconstructed index finger and the thin SCIP flaps survived. The patient was followed up for 28 months. The reconstructed index finger and donor defect of the great toe had a good appearance and postoperative range of motion of the reconstructed index finger was the same as the contralateral right index finger. The patient could walk and run normally without postoperative skin erosions or ulcerations (Figure 2).

FIG. 2.

A 36‐year‐old man with a finger amputated due to a crush injury. (A) Wound condition after hand debridement; (B, C) Appearance after left hand flap repair; (D–F) Design and cutting process of SCIP flap; (G, H) Appearance after repair of big toe donor area flap; (I) Reconstruction of left index finger Postoperative appearance; (J–M) Follow‐up of finger and big toe donor sites at 30 months postoperatively

Case 2

A 57‐year‐old man sustained a traumatic amputation of the right thumb from a blast injury. To restore the function and appearance of the affected thumb, toe‐to‐thumb transplantation was performed. From the examination of the groin region, the bilobed SCIP flap was designed. After dissection of the flap and adequate defatting, we were able to obtain a SCIP flap approximately 0.3 cm in thickness from the superficial branch of the superficial circumflex iliac artery. Twenty‐four months after surgery, the thin SCIP flap had a good appearance, without further flap revision or defatting procedures. The patient walks in shoes without difficulty. The function of the right thumb is satisfactory. From a cosmetic point of view, there is no problem with the wound on the right great toe. The scar of the groin donor site was hidden, and the appearance was not affected (Figure 3).

FIG. 3.

A 57‐year‐old man sought thumb reconstruction after traumatic amputation of his right thumb; (A–D) Flap design and cutting process; (E, F) Appearance after reconstruction of the right thumb; (G, H) Appearance of the donor area of the big toe after repair; (I–N) Follow‐up of the reconstructed thumb and the donor area of the big toe at 26 months after the operation

Discussion

For the repair of the great toe donor site defect after wrap‐around flap transfer, the treatment aims to choose a flap that provides good contour and is thin and pliable. Avoid the inconvenience of walking due to the bloated big toe affecting wearing shoes. We reviewed our experience in repairing the great toe donor site defect and proposed that the bilobed SCIP flap can better repair the donor site defect after wrap‐around flap transfer.

Analysis of Main Research Results

Thumb injuries leading to amputation are more common in daily life. ²⁰ In 1980, Morrison et al. first used a wraparound neurovascular free flap from the great toe successfully to reconstruct an amputated thumb. ³ This procedure has been widely used because it is excellent for reconstructing thumbs both aesthetically and functionally. However, the toe is the only donor site that provides nail. So, how to repair the donor site and return it to its original appearance and function has been a thorny problem in recent years.

In our study, 13 cases requiring donor site repair of the big toe after transfer of the surrounding flap were reported. All SCIP flaps survived successfully. According to a previous report, Liu et al. repaired five cases of distal foot skin defects using the median dorsal neurocutaneous flap, of which only one case showed superficial necrosis. ¹⁵ We follow up for more than 30.5 months on average to obtain the most accurate and detailed surgical results and patient satisfaction. The results of the reconstruction of the big toe were satisfactory, with only two patients experiencing hyperpigmentation complications. In our case series, we did not encounter any complications at the inguinal donor site. Because the average width of the flaps obtained was 8 cm, this may be the reason for the low incidence of inguinal donor sites. Through a large sample study, Peng et al. found that the peroneal artery perforator‐plus fasciocutaneous flap can also effectively repair soft tissue defects in the distal foot. ²¹ During the average follow‐up of 17.2 months, they found almost no obvious complications, which also provides a new idea for the repair of soft tissue defects in the distal foot. During our procedure, the average time from lift‐up to grafting to the donor site of the big toe was about 45 min, which highlights the convenience and speed of the SCIP flap. And it can cover the defect distal to the big toe without sacrificing the aorta.

Reasons for Designing a Bilobed SCIP Flap

Most previous studies have focused on single‐leaf SCIP flaps, and few have reported the use of bilobed SCIP flap in the donor site of the great toe after wrap‐around flap transfer. St. Laurent and Lanzetta et al. recommended reconstructing the wrap‐around donor site with a single leaf lateral forearm free flap. ²² Dong et al. reconstructed the wrap‐around donor site with reverse anterior tibial artery flap. ¹⁴ These methods use one paddle covering the donor site resulting in great toe bloating. However, the bloating great toe has caused many complications, including skin ulceration, erosion with shoe wearing and walking, a marked cosmetic defect, and an ugly appearance of the toe. ²³ , ²⁴ , ²⁵ Based on our preliminary anatomical and clinical studies, we found that the SCIP flap with a bilobed design could cover the ventral and dorsal toes, respectively, through a bilobed flap connected by a vascular pedicle. Compared with the single leaf flap, the advantage of the bilobed flap is that it reduces the bloat of the great toe web and the lateral flap of the toe, and the bilobed flap can be placed freely when repairing large areas of skin defects in the ventral and dorsal donor sites of the toe.

Technical Points of Dissecting SCIP Flap

Dissection of the SCIP flap in the superficial fascia layer between the superficial and deep fat layers not only protects the deep fascia but also reduces complications by reducing damage to the donor area such as lymph and nerves. ²⁶ This method is especially suitable for the dissection of the flap with thinner subcutaneous fat in the donor area (Figure 4). In our study, there were three patients who were obese and subcutaneous fat was hypertrophic, so the perforators were difficult to identify with the naked eye in the superficial fascia layer, so we chose to cut the flap on the deep fascia layer. In our improved technique, we dissect the SCIP flap from the superficial fascia layer, and then removed the excess fat of the flap under the microscope in the first stage, which can effectively avoid the defatting process in the second stage. Thin Flaps are particularly useful for reconstructing thin tissue areas such as hands and feet. In this way, pain and expense for the patient are reduced. As a result of this procedure, the great toe showed a better cosmetic appearance.

FIG. 4.

(A) The anatomy and design of the inguinal donor area. (B) The SCIP flap was dissected from the superficial fascia layer between the deep‐fat layer and superficial‐fat layer

Advantages and Disadvantages

This method has the following advantages: (1) the contours of the toe are reconstructed, with no bulging and atrophy of the great toe or deformity of the great toe; (2) the groin donor site is concealed, with soft skin texture and little hair, and the donor area can be sutured directly after surgery, leaving only a linear scar; (3) the SCIP flap is pliable, thin, and accessible; (4) removing the excess fat from the flap in the first stage can effectively avoid the defatting process in the second stage; (5) this method achieves the dual effect of aesthetic and functional reconstruction, which is in line with the flap repair concept of “good repair and reconstruction of the recipient area and little damage to the donor area”. At the same time, this method also has certain defects. The preparation of the bilobed SCIP flap is complicated, and the anatomical structure of the arteries is variable, which requires high skill and experience of the operator. Furthermore, it takes a long time to obtain the flap. Secondly, there is the complication of postoperative pigmentation.

Limitations

The follow‐up time of this study was long, and the patient's satisfaction with the operation was continuously tracked. But our study also has limitations. First, the study was a retrospective single‐center study without a control group. In addition, the sample size of the study was small, making it difficult to draw clear conclusions. Therefore, to overcome these limitations, in the next step we will observe more patients, record in detail the subcutaneous course of the superficial circumflex iliac artery, and improve the design of the flap.

Conclusion

This retrospective case study found that the SCIP thin flap with bilobed design can effectively repair the defect of the great toe donor site after wrap‐around flap transfer, reduce the swelling of the toe after surgery, and meet the dual requirements of function and aesthetics. To make our point more convincing, in future studies, we should collect more cases and receive single‐leaf and multi‐leaf SCIP flaps as controls. In conclusion, the current research results have certain guiding significance for clinical practice.

Author Contributions

Chaotao Hu and Songlin Xie designed the research. Biao Hou and Xiongjie Huang collected and analyzed the data. Yunhua Xu and Qiang He drafted the manuscript. Jiangang Song followed up with the patients. All authors contributed to the article and approved the submitted version.

Funding Information

This work was financially supported by Hunan Provincial Science and Technology Department (No.2021SK4030), Major Special Project of Hunan Provincial Health and Family Planning Commission (No.20201906), and Education Department of Hunan Province (No.21C0277).

Conflict of Interest

The authors have no conflicts of interest.