Combined Method with Free Omentum Flap and Split-thickness Skin Flap for Hand Reconstruction Following Radical Excision of an Arteriovenous Malformation

Summary:

The treatment for arterial venous malformation (AVM) of functionally and aesthetically important parts such as the hand is considered to be challenging. AVM existed in the right forearm and the thenar region of 55-year-old man. Combined method with free omentum flap and split-thickness skin flap was performed for hand reconstruction after radical excision of an AVM. The postoperative course was good. Seven years have passed postoperatively, and functional but aesthetical results are satisfying with no recurrence. Our operative procedure with complete resection of AVM with placement of the free omental flap to the resected area and placing back the original skin as a skin graft is considered to be an ideal curative surgical treatment of the AVM.

Arterial venous malformation (AVM) is classified as the high flow type of vascular malformation.^1–3 The treatment of functionally and aesthetically important parts of the body such as the head, the neck, and the extremities is considered to be challenging.

We achieved satisfying results by performing AVM resection, free omental flap transfer, and skin grafting for the treatment of AVM in the right thenar region.

CASE REPORT

The patient is 55-year-old man and right handed.

Swelling in his right palm began to appear 20 years ago, and it gradually began to multiply and enlarge.Pain and numbness began to appear, and he consulted with our department. Multiple tumors existed in his right forearm and the thenar region (Fig. 1A).Thrill was heard using the Doppler flow meter. A magnetic resonance imaging indicated the contrast-enhanced tumor with T2W1 high intensity in the dermis and subcutaneous layer. Angiography showed proliferation of vascular anomaly and nidus, and it was diagnosed as the high flow type of AVM (Fig. 1B). Due to the high flow velocity, sclerotherapy was considered to be difficult, and surgical treatment was planned.

Fig.1.

Preoperative findings. A, Multiple tumors existed in his right forearm and the thenar region. B, Angiography showed proliferation of vascular anomaly and nidus.

Operative Procedure

The operation team consisted of AVM resection team and free omental flap harvesting team, and they began their operations simultaneously. Zig-zag incision in the forearm to the thenarregion was performed. In the thenar region, AVM also existed in the dermis layer, and thus, separation of the tumor from the superficial dermis layer was carefully performed. AVM including the nidus was resected. After tourniquet was turned off, abnormal blood vessels and bleeding was ligated and coagulated, respectively. The omental flap was harvested by 3-cm skin incision at about 30 minutes. Harvested free omental flap was spread on the resected area, and the right gastroepiploic artery/vein and radial artery/cephalic vein were anastomosed. The flap was laid over with the elevated original skin of the palm as a skin graft (Fig. 2), and bulky dressing was performed for the postoperative dressing. The postoperative course was good. Seven years have passed postoperatively, and he has no pain sensory issues, but there was a mild loss of thermal sensory. In addition, there was no restriction on flexion and extension of the wrist joint. The functional and aesthetical results were satisfying with no recurrence(Fig. 3).

Fig.2.

Intraoperative findings. The flap was laid over with the elevated original skin of the palm as a skin graft. Anastomosed area in his forearm was covered with mesh skin grafting.

Fig.3.

Postoperative findings. It has been 7 years postoperatively, and functional and aesthetical results are satisfying with no recurrence.

DISCUSSION

AVM is thought to be a lesion with arteries and veins connected to abnormal blood vessels such as nidus. Many report that the pathology of this disease is ischemia,^4–6 and we have been treating AVM under this concept. Therefore, simple resection of the tumor only leads to recurrence due to abnormal proliferation of collateral circulation, and complete resection of the tumor with favorable tissue transfer with normal vascular formation is important for curative surgical treatment. It is also vital to consider postoperative functional and aesthetical results especially for the hand and fingers. In our case, we usedthe original skin from the palm and fingers, and this led to better functional and aesthetical result. In this case, AVM existed in the dermis layer, thus separation of the tumor from the superficial dermis layer was carefully performed, and the elevated skin was placed back as a skin graft. Generally, the omental flap has a very good vascularity. This helps to prevent the recurrence of arteriovenous malformations based on ischemia. When the omental flap is selected, surgery is possible at the same time because the location of the recipient and the donor are separate. The omental flap is thin and flexible, which leads to functional and cosmetic good results. It can be harvested by 3-cm skin incision within 30 minutes. This method has no sacrifice of the muscle, so it is less invasive. Our operative procedure with complete resection of AVM with placement of free omental flap to the resected area and placing back the original skin as a skin graft is considered to be an ideal curative surgical treatment of AVM.

ACKNOWLEDGMENT

Statement of Conformity: This study was conducted in accordance with the Declaration of Helsinki. The patients provided written informed consent for the publication and the use of their images.