Microvascular Free Transfer of A Compound Deep Circumflex Groin and Iliac Crest Flap to The Mandible



Microvascular Free Transfer of A Compound Deep Circumflex Groin and Iliac Crest Flap to The Mandible


G. I. TAYLOR

R. J. CORLETT





The vascular territory of the deep circumflex iliac artery encompasses a large amount of skin and bone that can be used for one-stage transfer with reliability. The bone graft is well vascularized and provides excellent contour for the mandible, and the donor site has minimal morbidity (1, 2). In addition to skin, other soft-tissue elements can be harvested with a common blood supply to provide a functional as well as an aesthetic result. This composite graft is best suited for the difficult problems encountered in head and neck reconstruction (3, 4, 5).




ANATOMY

The deep circumflex iliac artery arises from its posterolateral side at the level of the inguinal ligament. The artery, together with its paired venae comitantes, courses upward and laterally in its own fascial sheath behind the inguinal ligament toward the anterior superior iliac spine (Fig. 208.1). The paired venae comitantes join to form a single vein 2 to 3 cm lateral to the external iliac artery. This vein then characteristically diverges upward from its artery to reach the external iliac vein. In so doing, it crosses either in front of or behind the external iliac artery. At this point of divergence, there is usually a communication with one of the venae comitantes of the superficial circumflex iliac artery.

Approximately 1 cm medial to the anterior superior iliac spine, a large ascending muscular branch is given off. This vessel pierces the transversus muscle and the internal oblique. It may be found reliably 1 cm above and lateral to the anterior superior iliac spine. Rarely, the deep circumflex iliac vessels may lie in a more superficial plane, and when this occurs, the variation usually is associated with an abnormal obturator artery.







FIGURE 208.1 Diagram of the deep circumflex iliac artery with its periosteal supply to the inner cortex of the ilium and the musculocutaneous perforators that pierce the three muscles of the abdominal wall at intervals to nourish the overlying skin. The iliacus muscle is cross-batched. (From Taylor et al., ref. 2, with permission.)

The musculocutaneous perforators to the skin arise from the parent artery as it lies adjacent to the inner aspect of the ilium. They penetrate the muscles beyond the anterior superior iliac spine and emerge from the external oblique in a row approximately 1 cm above the iliac crest. The terminal part of the deep circumflex iliac artery usually emerges as the largest perforator 8 to 10 cm from the anterior superior iliac spine.

The deep circumflex iliac artery is 1.0 to 1.5 mm in diameter and is usually suitable for anastomosis. It can be used to provide a distal runoff from the graft or to connect to another vessel (e.g., the superficial circumflex iliac artery) to augment cutaneous circulation. After division of the three layers of the abdominal wall, the deep circumflex iliac artery will be found situated in the fold between the overhanging transversus muscle and the iliacus.


FLAP DESIGN AND DIMENSIONS

We perform angiography on most patients, which provides valuable information on both the donor and recipient vessels (Fig. 208.2). It outlines the effects of previous surgery, radiation, or tumor expansion on the vascular anatomy. The finding of an abnormal obturator artery in the groin is a preoperative warning that the course of the deep circumflex iliac artery may be more superficial than normal, although we have yet to encounter this in a clinical case.

The presence or absence of suitable recipient vessels on one side of the neck is noted after neck dissection or radiation therapy, and this predicts the need for vein grafts or a modification of graft design.






FIGURE 208.2 Angiogram showing the characteristic “paintbrush stroke” of the deep circumflex iliac artery passing upward and laterally at 45 degrees from the region of the hip joint. (From Taylor, Daniel, ref. 11, with permission.)

An acrylic pelvis with detachable iliac crests is a useful aid when selecting the donor hip for planning the correct orientation of the graft. A methyl methacrylate replica of the bone defect is made preoperatively and used both in the planning and as a preoperative check of the size and shape of the graft both at the donor and recipient sites (Fig. 208.4). The mandible may be designed from the iliac crest in one of three ways, depending on the length of graft required and the position of the vascular pedicle (see Fig. 208.1).

Jun 26, 2016 | Posted by in General Surgery | Comments Off on Microvascular Free Transfer of A Compound Deep Circumflex Groin and Iliac Crest Flap to The Mandible
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