The development of perforator flaps has popularized minimally invasive free flap reconstructions not only for adult patients but also for pediatric patients. The superficial circumflex iliac artery (SCIA) perforator (SCIP) flap is one of the most demanding flaps because it enables the inclusion of multiple components with 1 source vessel, and the donor site scar can be concealed by underwear. Furthermore, flap elevation with the superficial branch of the SCIA (SB-SCIA) as the source vessel has many advantages such as shortened surgical time and decreased donor morbidity owing to no damage to the deep layered tissue.
SCIP flap elevation can be performed using 2 major procedures: from distal to proximal or the opposite.1,2 Individual differences have been reported in the dominant vasculature in the groin area2; for successful flap elevation, it is important to detect the blood stream preoperatively with ultrasound or Doppler and access the vascular bundle with a proximal approach. However, infants and some pediatric patients were intolerant to this preoperative approach because they could not stay still. Therefore, anatomical assessment of the SB-SCIA is helpful for successful SCIP flap elevation in pediatric patients. To the best of our knowledge, anatomical assessment of the SB-SCIA in pediatric patients has not been performed previously. Moreover, the cadaver study of pediatric patients is not common. Therefore, we developed the skin incision design for the stat detection of the SB-SCIA in cases of SB-SCIP flap transfer. We aimed to evaluate the efficacy of our system for detecting the SB-SCIA location and measuring the vessel diameter.
MATERIALs AND METHODS
Our study included 11 consecutive pediatric patients who required harvesting, either skin grafting or vascularized lymph node transfer, from the inguinal area. All procedures were performed under general anesthesia in the supine position by 3 certificated plastic surgeons, randomly. No incision was made in the bilateral groin area. The study protocol was approved by our institutional ethical board. Informed consent, as a part of the operation consent form, was obtained from the guardians of the patients.
Skin Incision Design
The incision design was applied on the contralateral side of the malformation to reduce the possible bias due to vessel anomaly. All patients were placed in the supine position. The skin incision was performed in 3 steps (Fig. 1).
First, we marked the following points: the anterior supine of the iliac bone (AS), lateral superior edge of the pubis (LP), and the superior medial edge of the pubis (MP; Fig. 1A). Second, we marked a line between these pubis points (MP-LP), a vertebral line on the AS perpendicular to the pubis line (V-AS), and the pulsated center of the femoral artery on the pubis line (FA; Fig. 1B). Third, we drew a line joining AS and LP (AS-LP), and the intersection with the parallel line to V-AS (drawn from FA) was named as D. The skin incision was designed 1.5 cm toward AS on AS-LP (Fig. 1C), and the SB-SCIA bundles were dissected under 2.5× surgical loupe magnification. The distances MP-LP, LP-FA, FA-V, and V-AS were measured for the analysis. The size of each distance, the dissection time, calibers of the bundle and each vessel, and the point at which the surgeon detected the bundles were evaluated. In cases of skin graft harvesting, just after the SB-SCIA was measured, the dissection was completed to reduce unnecessary damage to the deep layered tissue. Before vessel measurement, 2% lidocaine was applied from the surface of the vessels to release possible vascular spasms. The tissue harvest was not performed until the vascular investigation was complete.
The statistical analysis was performed using the Student’s t test.
Of the 11 patients, 4 (37%) were boys. The age range was 5 months to 14 years (mean: 3.2 years, median: 1.0 years). Eight of 11 (79%) cases were either of burn injury or congenital syndactyly who required skin grafts. No patient had congenital anomaly on the inguinal area.
In all patients, the SB-SCIA bundle was successfully dissected within 5 min (1–5 min, mean: 2.5 min) (Fig. 2). No vascular damage was observed. All dissected arteries pulsated well, without requiring additional skin incision [see video, Supplementary Digital Content 1, which displays dissection of the SB-SCIA vascular bundle with a skin incision made using the present stat design system (case #9), http://links.lww.com/PRSGO/B19]. The vessel bundles were 0.7–1.5 (mean: 1.1 mm), arteries were 0.5–0.7 mm (mean: 0.58 mm), and the dominant concomitant vein was 0.4–0.8 mm (mean: 0.52 mm) (Table 1). The SB-SCIA bundle was mainly detected right below the initial skin incision line. Only in 3 cases (27%), the bundle was detected slightly medial or lateral to the initial incision, however, within the skin traction distance. No postoperative complications were detected at the donor site.
The lengths between LP-FA and FA-V were 20–33 mm (mean: 23.6 mm) and 20–33 mm (mean: 24.2 mm), respectively. The LP-FA/FA-V ratio was 0.98 ± 0.04 (Table 1).
We developed a simple incision design to detect the SB-SCIA for SCIP flap elevation in pediatric patients. In all the present cases, detection was easily possible within 5 min.
The SCIP flap is a modified perforator flap of the conventional groin flap.3,4 Groin flap was the first vascularized skin-free flap reported in the early 1970s.5 The perforator-based flap on the groin area was established in 2004.4 Recent studies have performed flap elevation above the superficial layer by only including the SB-SCIA to reduce donor morbidity.1,6 Although this flap elevation procedure was less invasive, the vascular diameters were sometimes very small, occasionally requiring supermicrosurgical anastomoses.6–8
The SCIP flap vascularized based on the superficial branch (SB-SCIP flap) has the following advantages: decreased donor morbidity,9–11 reliable vascularity,4,12 short time for flap elevation,1,8,13 and multiple tissue/component inclusion.13–17
These advantages are particularly meaningful in pediatric patients.10,18–23 The donor site has been frequently used for skin graft harvesting.18,19,23 The donor site scars are usually concealable with underwear.20, 22 Furthermore, the SB-SCIP flap elevation does not include deep tissue dissection, including lymphatic system or nerves, thereby preventing possible postoperative complications such as lymphorrhea or nerve injury.8,12,24 The flap can be elevated with an axial pattern vascularity, reducing vessel damage.8,15 In the present study, all cases had well-pulsated arteries with 0.5-mm diameter. Supermicrosurgical anastomoses are typically required for free tissue transfers; notably, elevation and anastomosis are possible because the vessels are larger than 0.5 mm in diameter, as seen even in the infants of the present study. Importantly, we can reduce surgical time for SCIP flap elevation by proximal dissection of the SCIA. Furthermore, multiple tissues such as lymph nodes, lymph vessels,8 bones,25 muscles,26 adipose tissue, and skin can be included with a single source vessel. In addition, the flap can be trimmed to meet the demands of the defects, such as pure skin perforator flap for very thin skin flap or multiple skin paddles.1,8
The proximal dissection for initial source vessel detection has been advantageous because the surgeons can be aware of the vascular system included into the flap.2 The relationship among other branches for the groin flaps was considered complementary; sometimes, the vascularity was reliable on either the deep branch of the SCIA or superficial inferior epigastric artery system. Our skin incision was made in the middle of the positions of these other possible flaps; therefore, switching to those flaps is possible using the initial incision in the case of complications such as pedicle damage during the dissection.
This design is based on the relative position according to body points, and not on the absolute distance, and therefore, can be applied across all age groups. Furthermore, the distances LP-FA and FA-V were almost equal in all patients (LP-FA/FA-V ratio: 0.98 ± 0.04). Therefore, a simple skin incision line from the middle point of AS-LP toward AS might also be a substitute. In fact, we were able to elevate and transfer the SCIP flap with vascularized iliac bone included in a 1-year-old boy with hypoplastic thumb (type 3) (Fig 3).
Previous perforator location analysis studies on adult patients were mainly designed based on the distance from the AS-LP, the inguinal ligament. Few studies have reported the perforator location of pediatric SCIA. However, our study results reveal that the vertebral length (V-AS) increases more drastically than the horizontal length (MP-V) with body growth, and the inguinal ligament angle changes with increase in body size. Therefore, our incision design might be better suited to pediatric settings because the landmark points are constant, and the inguinal ligament angle was not factored in our system.
Our study has limitations. We might have overtaken the other branch as the SB-SCIA because we did not dissect the entire vascular length to avoid unnecessary damage to the pediatric patients. However, preoperative ultrasound showed the branch to be SB-SCIA. Furthermore, for flap elevation from the groin area, identifying the dominant and reliable vessel is a major concern, which was successfully achieved with our design. Moreover, based on our clinical experience of SCIP flap elevation, the location of the SB-SCIA was compatible with that found using the present design. Further studies with larger number of cases should be conducted to validate the results presented here and develop effective variations.
Altogether, this study is the first to conduct an SCIA anatomical study in pediatric patients. The skin incision design developed here effectively detected the SCIA in pediatric patients and may also be applied to adult patients.
1. Hong JP, Choi DH, Suh H, et al. A new plane of elevation: the superficial fascial plane for perforator flap elevation. J Reconstr Microsurg. 2014;30:491–496.
2. Yoshimatsu H, Yamamoto T, Hayashi A, et al. Proximal-to-distally elevated superficial circumflex iliac artery perforator flap enabling hybrid reconstruction. Plast Reconstr Surg. 2016;138:910–922.
3. McGregor IA, Jackson IT. The groin flap. Br J Plast Surg. 1972;25:3–16.
4. Koshima I, Nanba Y, Tsutsui T, et al. Superficial circumflex iliac artery perforator flap for reconstruction of limb defects. Plast Reconstr Surg. 2004;113:233–240.
5. Daniel RK, Taylor GI. Distant transfer of an island flap by microvascular anastomoses. A clinical technique. Plast Reconstr Surg. 1973;52:111–117.
6. Song JW, Ben-Nakhi M, Hong JP. Reconstruction of lower extremity with perforator free flaps by free style approach in pediatric patients. J Reconstr Microsurg. 2012;28:589–594.
7. Harii K, Ohmori K. Free groin flaps in children. Plast Reconstr Surg. 1975;55:588–592.
8. Choi DH, Goh T, Cho JY, et al. Thin superficial circumflex iliac artery perforator flap and supermicrosurgery technique for face reconstruction. J Craniofac Surg. 2014;25:2130–2133.
9. Van Landuyt K, Hamdi M, Blondeel P, et al. Free perforator flaps in children. Plast Reconstr Surg. 2005;116:159–169.
10. Sonmez E, Nasir S, Safak T, et al. Free groin flap applications in the pediatric population. J Reconstr Microsurg. 2010;26:259–264.
11. Yano T, Okazaki M, Kawaguchi R, et al. Tongue reconstruction with minimal donor site morbidity using a deep inferior epigastric perforator (DIEP) free flap in a 6-year-old girl. Microsurgery. 2013;33:487–490.
12. Suh HS, Jeong HH, Hong JP. The study of medial superficial perforator of the superficial circumflex iliac artery perforator flap using CT angiography and surgical anatomy in 142 patients. Plast Reconstr Surg. 2016.
13. Iida T, Yamamoto T, Yoshimatsu H, et al. Supermicrosurgical free sensate superficial circumflex iliac artery perforator flap for reconstruction of a soft tissue defect of the ankle in a 1-year-old child. Microsurgery. 2016;36:254–258.
14. Koshima I, Nanba Y, Nagai A, et al. Penile reconstruction with bilateral superficial circumflex iliac artery perforator (SCIP) flaps. J Reconstr Microsurg. 2006;22:137–142.
15. Iida T, Mihara M, Yoshimatsu H, et al. Reconstruction of the external auditory canal using a super-thin superficial circumflex iliac perforator flap after tumour resection. J Plast Reconstr Aesthet Surg. 2013;66:430–433.
16. Iida T, Narushima M, Yoshimatsu H, et al. Versatility of lateral cutaneous branches of intercostal vessels and nerves: anatomical study and clinical application. J Plast Reconstr Aesthet Surg. 2013;66:1564–1568.
17. Iida T, Yoshimatsu H, Hara H, et al. Reconstruction of large facial defects using a sensate superficial circumflex iliac perforator flap based on the lateral cutaneous branches of the intercostal nerves. Ann Plast Surg. 2014;72:328–331.
18. May JW Jr, Bartlett SP. Staged groin flap in reconstruction of the pediatric hand. J Hand Surg Am. 1981;6:163–171.
19. Chuang DC, Colony LH, Chen HC, et al. Groin flap design and versatility. Plast Reconstr Surg. 1989;84:100–107.
20. Isenberg JS, Nguyen H, Salomon J. Bilateral simultaneous groin flaps in the salvage of a pediatric blast-injured hand. Ann Plast Surg. 1994;33:415–417.
21. Duteille F, Lim A, Dautel G. Free flap coverage of upper and lower limb tissue defects in children: a series of 22 patients. Ann Plast Surg. 2003;50:344–349.
22. Clarke HM, Upton J, Zuker RM, et al. Pediatric free tissue transfer: an evaluation of 99 cases. Can J Surg. 1993;36:525–528.
23. Mast BA, Newton ED. Aggressive use of free flaps in children for burn scar contractures and other soft-tissue deficits. Ann Plast Surg. 1996;36:569–575.
24. Iida T. Superficial circumflex iliac perforator (SCIP) flap: variations of the SCIP flap and their clinical applications. J Reconstr Microsurg. 2014;30:505–508.
25. Iida T, Narushima M, Yoshimatsu H, et al. A free vascularised iliac bone flap based on superficial circumflex iliac perforators for head and neck reconstruction. J Plast Reconstr Aesthet Surg. 2013;66:1596–1599.
26. Yoshimatsu H, Yamamoto T, Hayashi N, Kato M, Iida T, Koshima I. Reconstruction of the ankle complex wound with a fabricated superficial circumflex iliac artery chimeric flap including the sartorius muscle: a case report. Microsurgery. 2017;37:421–425.