Pre-expanded Paraumbilical Perforator Flap

The paraumbilical perforator flap is the first and the most famous perforator flap. Pre-expansion increases the flap dimension and reduces the flap thickness and donor site morbidities, making the paraumbilical perforator flap a more effective option for upper extremity reconstruction. Pre-expanded pedicled paraumbilical perforator flaps can achieve excellent function and aesthetic outcomes in patients with extensive scar contracture and giant melanocytic nevi in the upper extremity. Although this technique requires multiple procures, each operation is relatively simple and has a low complication rate, when properly planned and performed.

Key points

  • Paraumbilical perforator flap is based on deep inferior epigastric artery perforators, with a superolateral extension of skin paddle to the lateral chest wall.

  • Many of the disadvantages of pedicled paraumbilical perforator flaps are offset by pretransfer expansion.

  • With proper planning and precise definition of the pre-expansion area, the expander placement is quick and safe.

  • Because there is no need to dissect the perforators through the muscle, expanded pedicled paraumbilical perforator flaps are reliable and easy to elevate.

  • Capsulectomy and primary thinning of the flap are safely performed.

Introduction

The paraumbilical perforator flap is a paraumbilical flap based on the perforators derived from the deep inferior epigastric artery (DIEA). According to the “Gent” consensus on perforator flap terminology, it should be called DIEA perforator flap. The paraumbilical perforator flap was first described by Koshima and coworkers in 1991. He later described this flap as a superthin DIEA perforator flap or paraumbilical perforator flaps without DIEA that required supermicrosurgery for vascular anastomosis. Nowadays, most authors use the name “paraumbilical perforator flap” to address a flap design that is different from the DIEA perforator flap with the transverse skin paddle for breast reconstruction.

The early anatomic study of Taylor and colleagues showed that the perforators from DIEA extended radially like the spokes of a wheel. The perforators connect with other artery systems in anterior trunk via choke vessel, including deep superior epigastric artery, intercostal artery, and superficial inferior epigastric artery. The flap can be elevated in many directions along the axes that radiated from the umbilicus. However, because of the dominant connections with intercostal artery perforators, the best flap design seems to be the one planned along the axis between the umbilicus and the inferior angle of the scapula.

The flap based on DIEA perforators with superolateral extension of skin paddle was called the oblique paraumbilical perforator flap by some and the extended DIEA perforator flap by others. Compared with the transversely designed DIEA perforator flap, this obliquely extended flap has longer pedicle and larger arc of rotation, and its distal portion from the chest wall was relatively thin, thus it was suggested as a good distant pedicled flap option for upper extremity reconstruction. The flap was found to offer reliable coverage for the hand, wrist, and forearm.

However, the usage of this flap in upper extremity reconstruction is limited by several factors. The donor tissue can be insufficient when dealing with massive wounds. The relative thick abdominal portion of the flap, especially in obese patients, appears bulky and unnatural in the upper extremity. In addition, the pedicled flap, owing to the limited pedicle length, can hardly reach defects beyond the proximal forearm. To overcome those limitations, we combined the flap transfer with pretransfer expansion. In this article, we demonstrate the value of pre-expanded perforator-based paraumbilical flaps in upper extremity reconstruction and summarize our experiences of using this technique in patients with extensive upper extremity soft tissue defects.

Introduction

The paraumbilical perforator flap is a paraumbilical flap based on the perforators derived from the deep inferior epigastric artery (DIEA). According to the “Gent” consensus on perforator flap terminology, it should be called DIEA perforator flap. The paraumbilical perforator flap was first described by Koshima and coworkers in 1991. He later described this flap as a superthin DIEA perforator flap or paraumbilical perforator flaps without DIEA that required supermicrosurgery for vascular anastomosis. Nowadays, most authors use the name “paraumbilical perforator flap” to address a flap design that is different from the DIEA perforator flap with the transverse skin paddle for breast reconstruction.

The early anatomic study of Taylor and colleagues showed that the perforators from DIEA extended radially like the spokes of a wheel. The perforators connect with other artery systems in anterior trunk via choke vessel, including deep superior epigastric artery, intercostal artery, and superficial inferior epigastric artery. The flap can be elevated in many directions along the axes that radiated from the umbilicus. However, because of the dominant connections with intercostal artery perforators, the best flap design seems to be the one planned along the axis between the umbilicus and the inferior angle of the scapula.

The flap based on DIEA perforators with superolateral extension of skin paddle was called the oblique paraumbilical perforator flap by some and the extended DIEA perforator flap by others. Compared with the transversely designed DIEA perforator flap, this obliquely extended flap has longer pedicle and larger arc of rotation, and its distal portion from the chest wall was relatively thin, thus it was suggested as a good distant pedicled flap option for upper extremity reconstruction. The flap was found to offer reliable coverage for the hand, wrist, and forearm.

However, the usage of this flap in upper extremity reconstruction is limited by several factors. The donor tissue can be insufficient when dealing with massive wounds. The relative thick abdominal portion of the flap, especially in obese patients, appears bulky and unnatural in the upper extremity. In addition, the pedicled flap, owing to the limited pedicle length, can hardly reach defects beyond the proximal forearm. To overcome those limitations, we combined the flap transfer with pretransfer expansion. In this article, we demonstrate the value of pre-expanded perforator-based paraumbilical flaps in upper extremity reconstruction and summarize our experiences of using this technique in patients with extensive upper extremity soft tissue defects.

Treatment goals and planned outcomes

We applied the pre-expanded paraumbilical perforator flap mainly in patients with extensive scar and giant congenital melanocytic nevi in upper extremity, to achieve excellent functional and aesthetic outcomes. This technique provides a large, thin flap with similar color and texture for upper extremity reconstruction. Our experience with more than 90 flaps supports the claim that this technique is safe and successful in achieving superior aesthetic results. When properly planned and performed, these operations have a low complication rate and minimal donor site morbidity.

Preoperative planning and preparation

Before implantation of the tissue expander, the dimension of the wound is evaluated ( Figs. 1 and 2 ). In the cases of burn reconstruction, the defect size following scar contracture release is estimated by referring to the corresponding area in the unaffected side. Doppler ultrasound probe is used to identify at least two large perforators adjacent to the ipsilateral umbilicus.

Fig. 1
Graphic scheme of the design of the pre-expanded flap design.

Fig. 2
( A ) Two large perforators in the paraumbilical area were detected by using Doppler ultrasound probe. The pre-expanded area was oriented along the axis between the umbilicus and the inferior angle of the scapula. The superior border was selected as the incision for expander placement. ( B ) The pre-expanded area was extended laterally to the posterior axillary line.

The pre-expanded area is designed slightly larger than the estimated defect dimension in the anterior abdomen, and is oriented along the axis between the umbilicus and the inferior angle of the scapula. We plan the medial border of pre-expanded area just lateral to the points where we detect the perforators. The pre-expanded area can be extended to the posterior axillary line, creating a sufficient space for placing a large expander in adult and pediatric patients. The pre-expansion area usually includes the lower ribs superiorly in the chest wall. Because the hard thoracic cage cannot absorb the expansion force of tissue expanders, the tissue expansion over the chest wall is effective. However, in the female patient, expansion of the area immediately below the inframammary fold should be avoided to prevent breast deformation.

Patient positioning

For tissue expander placement and removal, the patient should be in the supine position with the affected upper extremity abducted. For the second stage-procedure, we usually plan the lateral border of the flap at the posterior axillary line. To give a better exposure of this area, cushions should be put under the patients’ buttock and shoulder. This maneuver facilitates the flap elevation and closure of the donor site.

Procedural approach

Pre-expansion of the Paraumbilical Perforator Flap

The superior edge of the designed area is selected as the incision for expander placement. The incision is made down to the deep fascia and a pocket is created superficially to the external oblique aponeurosis within the marked pre-expansion area. The dissection is carried out quickly by using electrotome until the selected perforators are visualized. To avoid potential damage to the perforators, we do not expose the penetrating point from the anterior sheath of the perforator ( Fig. 3 A ). Other perforators emerging during the dissection, especially from the intercostal artery system, are ligated using bipolar coagulator or clips ( Fig. 3 B). Then the rectangular expanders with proper size are placed into the pocket. In some adult patients, two large expanders might be implanted. The filler valves are routinely positioned over the lateral chest wall.

Fig. 3
( A ) During the dissection, several perforators were observed penetrating the external oblique abdominal muscle. These perforators derived from intercostal artery and were ligated to initiate a delay effect. ( B ) The paraumbilical perforators previously detected were visualized and the dissection was terminated at this point to avoid incidental damage of the pedicle perforators.

Expansion is begun 14 days later with normal saline added on a weekly interval until adequate volume has been achieved. The flap is always overexpanded to obtain more donor tissue and to achieve direct closure of the donor site.

Transfer of Pre-expanded Paraumbilical Perforator Flap

The perforators are relocated using the Doppler probe. A pattern is made and placed over the expanded skin. The dimension of the flap is marked making the previous incision the flap superior border. A wide pedicle is designed to include the preoperatively identified perforators and to facilitate skin tube formation.

With consideration of minimal pedicle tension and most comfortable arm position following flap transfer, only half of the upper extremity lesion is resected. The flap is elevated following the expander removal ( Fig. 4 A ). As a pedicle flap, dissection of the perforators during the flap elevation is unnecessary. Capsulectomy and immediate flap debulking are performed in some patients with relatively thick flaps. The capsule near the pedicle is preserved to protect the perforators and their branches ( Fig. 4 B, C). The flap is then transferred and inset to the upper extremity wound, with its proximal portion sutured as a skin tube. The donor site is directly closed after drainage placement. The patient’s arm is immobilized to avoid pedicle avulsion with assistance of a circumferential bandage.

Nov 21, 2017 | Posted by in Dental Materials | Comments Off on Pre-expanded Paraumbilical Perforator Flap
Premium Wordpress Themes by UFO Themes