Free Anterolateral Thigh Flap Reconstruction After Excision of Extensive Vascular Malformations in Toddlers: Report of Two Cases

ABSTRACT

Vascular malformations often become symptomatic during childhood and require multidisciplinary intervention. However, reports of resection followed by free flap reconstruction in pediatric patients remain rare. We report two toddler cases of vascular malformations reconstructed with free anterolateral thigh (ALT) flaps. Case 1 was a 2‐year‐old boy with a submandibular venous malformation complicated by coagulopathy. After lesion resection with overlying skin (5 × 10 cm), an ALT flap (5.5 × 12 cm) was transferred. The flap artery was interposed with the transected facial artery, and the veins were anastomosed end‐to‐side to the internal and external jugular veins. The flap survived completely, and coagulation parameters normalized. Case 2 was a 3‐year‐old boy with a painful forearm ulcer caused by a capillary lymphatic venous malformation. After ulcer debridement (5.5 × 13 cm), the defect was reconstructed with an ALT flap (6 × 14 cm). The flap vessels were anastomosed to the radial artery and its concomitant veins in a flow‐through manner. Partial flap necrosis required secondary wound closure, but the ulcer did not recur, and the pain resolved completely. No anastomotic failure or donor‐site complications occurred in either case. Extensive resection followed by ALT flap reconstruction is a reliable option for pediatric vascular malformations. Meticulous microvascular techniques and multiple anastomoses may reduce microvascular complications in young patients.

1. Introduction

Vascular malformations are congenital anomalies of vascular and/or lymphatic structures that arise during embryonic angiogenesis (Cooke‐Barber et al. ²⁰²⁰; Gibson and Barnacle ²⁰²⁰; Zhuo et al. ²⁰¹⁷). Although present at birth, the clinical onset varies. These lesions can occur anywhere in the body and may present as cosmetic deformity, pain, bleeding, or functional impairment, leading to significant reductions in quality of life.

Treatment options include compression garments, sclerotherapy, and targeted systemic therapies (Lokhorst et al. 2021). Nevertheless, surgical resection remains an effective treatment for achieving definitive results. Extensive resections, however, often produce large soft tissue defects that require reconstruction. Although free flap transfer provides a versatile method for reconstruction, reports of free flap reconstruction after vascular malformation excision in pediatric patients remain scarce (Upton and Guo 2008; Gharb et al. ²⁰¹¹).

Compared with other free flaps—including the groin, radial forearm, and scapular flaps—the anterolateral thigh (ALT) flap provides a larger skin paddle, results in lower donor‐site morbidity, and allows harvest without patient repositioning. These advantages are especially beneficial in small children (Srikanth 2019).

We report two toddler cases with extensive vascular malformations successfully reconstructed using free ALT flaps, highlighting technical strategies for microvascular anastomosis in small‐caliber vessels.

2. Case Reports

2.1. Case 1

A 2‐year‐old (30‐months‐old) boy presented with an enlarging submandibular venous malformation (Figure 1a). Multiple purpuric lesions, an elevated D‐dimer level (25.7 μg/mL), and a low plasma fibrinogen level (93 mg/dL) were noted, reflecting consumptive coagulopathy. Magnetic resonance imaging (MRI) using a STIR sequence showed the submandibular lesion with high signal intensity (Figure 1b).

FIGURE 1.

(a) Preoperative photograph of Case 1. (b) Magnetic resonance image.

The lesion and overlying skin were resected, resulting in a 5‐ × 10‐cm defect with partial exposure of the mandible (Figure 2a). An ALT flap measuring 5.5 × 12 cm, incorporating one musculocutaneous perforator, was harvested from the right thigh (Figure 2b) using a 2.5× magnification loupe and transferred to the defect. The vessel caliber was approximately 1.0 mm. The donor site was closed primarily. The descending branch of the lateral circumflex femoral artery and its branch were anastomosed to the facial artery in a flow‐through manner. Two concomitant veins were anastomosed end‐to‐side to the internal and external jugular veins (Figure 2c,d). The intraoperative blood loss was 105 mL. No perioperative anticoagulant was used, and pinprick testing of the flap was performed three times a day for 1 week after the surgery.

FIGURE 2.

(a) Intraoperative view after lesion resection. The arrow indicates the mandible. (b) Harvested flap. The arrowhead indicates a perforator. (c) Photograph and (d) schematic of the anastomoses. Postoperative photographs of the (e) neck and (f) thigh. ALT, anterolateral thigh flap; EJV, external jugular vein; FA, facial artery; HY, hyoid bone; IJV, internal jugular vein; MD, mandible; PG, parotid gland; SCM, sternocleidomastoid muscle; SG, submandibular gland.

The postoperative course was uneventful, and the flap survived completely. At 13 months after surgery, there was no recurrence of the disease, and a favorable aesthetic outcome was achieved (Figure 2e,f). In addition, the D‐dimer and plasma fibrinogen levels normalized (0.5 μg/mL and 223 mg/dL, respectively), indicating remission of the coagulopathy.

2.2. Case 2

A 3‐year‐old (36‐months‐old) boy presented with a capillary lymphatic venous malformation of the left upper arm. He had previously undergone V‐beam laser treatment for the lesion, which resulted in a large ulcer (Figure 3a). The ulcer caused severe pain, impairing activities of daily living, including bathing. On STIR MRI, the ulcer was surrounded by subcutaneous tissue showing high signal intensity (Figure 3b).

FIGURE 3.

(a) Preoperative photograph of Case 2. (b) Magnetic resonance image.

Debridement of the ulcer created a defect with exposure of the superficial branch of the radial nerve (Figure 4a). An ALT flap measuring 6 × 14 cm, incorporating two musculocutaneous perforators, was harvested from the right thigh (Figure 4b) using a 2.5× magnification loupe and transferred to the defect. The vessel caliber was approximately 1.5 mm. The main trunk and ascending branch of the lateral circumflex femoral artery were anastomosed to the radial artery in a flow‐through manner. Of the two concomitant veins, one was interposed with the radial vein in a flow‐through fashion, while the other was anastomosed end‐to‐end to the subcutaneous cephalic vein (Figure 4c,d). The surgery was performed without a tourniquet to prevent vascular collapse. The intraoperative blood loss was 105 mL. No perioperative anticoagulant was used, and the flap was monitored three times a day for 1 week after the surgery.

FIGURE 4.

(a) Intraoperative view after lesion resection. The arrows indicate the superficial branch of the radial nerve. (b) Harvested flap. The arrowheads indicate two perforators. (c) Photograph and (d) schematic of the anastomoses. Postoperative photographs of the (e) forearm and (f) thigh. ALT, anterolateral thigh flap; CV, concomitant vein; RA, radial artery; SV, subcutaneous vein.

Partial necrosis of the flap margins developed postoperatively. On day 14, the necrotic tissue was debrided 1.5 cm proximally and 0.5 cm distally, followed by primary closure. At 22 months after surgery, the patient remained pain‐free, and the ulcer had not recurred (Figure 4e,f).

3. Discussion

Reports of free ALT flap reconstruction in pediatric patients are limited. Few involve children younger than 3 years, and most describe traumatic injuries (Upton and Guo 2008; Gharb et al. ²⁰¹¹; Srikanth ²⁰¹⁹; El‐Gammal et al. ²⁰¹³; Acar et al. ²⁰¹⁵; Merter et al. ²⁰¹⁷). The present cases represent the youngest patients to undergo free ALT flap transfer for extensive vascular malformations.

Microsurgery in toddlers poses unique physiologic challenges, including vasospasm, thermoregulation, and coagulation imbalance. The small vessel caliber and immature autonomic regulation increase susceptibility to vasoconstriction and vasospasm (Burns et al. 2023). Furthermore, vascular malformations involve altered vascular architecture and potential coagulopathy, as seen in Case 1, complicating extensive resection and successful free flap transfer (Gibson and Barnacle 2020).

To overcome these obstacles, we applied multiple anastomotic strategies—combining flow‐through and end‐to‐side techniques—to maintain physiologic blood flow and reduce the risk of thrombosis. These techniques preserve recipient vessel continuity and stabilize hemodynamics in small‐caliber vessels, providing valuable options in pediatric microsurgery (Kagaya et al. 2021; Fujiki et al. ²⁰¹⁵). Tailoring the number and configuration of anastomoses according to vessel size, location, and disease‐specific considerations represents a technical contribution to current pediatric microsurgical practice.

Several alternatives can be considered for reconstruction of large pediatric defects. Perforator‐based local flaps provide excellent texture matching but are limited in size and mobility. Pedicled groin flaps are traditional options for upper extremity defects; however, forced limb positioning restricts their use in small children. The latissimus dorsi flap is one of the most commonly performed free flaps, but it often requires patient repositioning for harvest. The free groin flap offers minimal donor‐site morbidity; however, its vascular pedicle is smaller in caliber, and the available flap size is generally more limited than that of the ALT flap (Mosahebi et al. 2008; Ohmori et al. ¹⁹⁷⁷).

The free ALT flap combines the advantages of a long, sizable vascular pedicle and the ability to harvest the flap without repositioning, which enables a two‐team approach and decreases operative time. However, disadvantages of the ALT flap in young children include thick subcutaneous fat and a thin dermal layer. These limitations can be mitigated through careful perforator dissection and flap thinning. Despite these challenges, the versatility, reliability, and adaptability of the ALT flap made it the most suitable option for our patients (Ohmori et al. 1977; Ayad et al. ²⁰²⁴).

In Case 2, partial flap necrosis occurred, whereas the smaller flap in Case 1 (5.5 × 12 cm) survived completely. This may reflect flap size limitations relative to perforator blood supply in toddlers. The flap in Case 2 (6 × 14 cm; 84 cm²) exceeded the sizes previously reported (35–60 cm²). (Upton and Guo 2008; Gharb et al. ²⁰¹¹; Srikanth ²⁰¹⁹; El‐Gammal et al. ²⁰¹³; Acar et al. ²⁰¹⁵; Merter et al. ²⁰¹⁷) Larger flaps in toddlers may require more than two perforators, incorporation of tensor fascia lata flaps, or additional vascular anastomoses to prevent partial necrosis.

Surgical indications for pediatric vascular malformations remain challenging. Primary indications include functional impairment, pain, and bleeding risk (Cooke‐Barber et al. ²⁰²⁰; Gibson and Barnacle ²⁰²⁰). Extensive lesions in visible locations may also justify surgery for cosmetic reasons. In pediatric patients, the long‐term effects of surgery must be carefully weighed because growth and development may be influenced by surgical invasiveness. Less invasive strategies, such as targeted therapy or topical treatments, may in the future complement or replace surgical management (Lokhorst et al. 2021). Interventional radiology procedures that occlude arteriovenous shunts are less invasive and represent an effective treatment option for fast‐flow vascular malformations (Gibson and Barnacle 2020).

In summary, free ALT flap reconstruction remains a versatile option even in toddlers with vascular malformations. Awareness of age‐ and disease‐specific physiologic challenges, together with the use of multiple anastomotic strategies, can help optimize outcomes in this demanding population.

Funding

The authors have nothing to report.

Ethics Statement

This report of two cases was exempted from Institutional Review Board (IRB) review according to the policy of our institution.

Consent

Informed consent was obtained from the patient for publication of this case report.

Conflicts of Interest

The authors declare no conflicts of interest.

Fujisawa, K. , Miyamoto S., and Okazaki M.. 2026. “Free Anterolateral Thigh Flap Reconstruction After Excision of Extensive Vascular Malformations in Toddlers: Report of Two Cases.” Microsurgery 46, no. 1: e70173. 10.1002/micr.70173.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.