Wednesday, November 17, 2010

Latisimus Dorsi Myocutaneous Flap with Extended Skin Paddle for Cross Midline Chest Wall Defects

The latissimus dorsi myocutaneous flap continues to be one of the workhorse flaps used in Plastic & Reconstructive Surgery. The words latissimus dorsi means "broadest of the back" and it is this characteristic that allows it to cover large defects locally, regionally, and for distant transfer. The latissumus dorsi muscle is a Nahai & Mathes type V muscle with its blood supply originating from the thoracodorsal vessels as well as paraspinal lumbar perforators.
I have found that the extent of the skin paddle used for the latissumus dorsi can be extended beyond those stated in standard textbooks. The skin paddle can be as wide as the breadth of the muscle and allow primary closure in the back. The length of the skin paddle can be upwards of 22 inches or greater depending upon how many perforators are incorporated into the skin paddle.
In the photo below, radiation has caused significant burn to the anterior chest leaving an open wound with exposed bone. Adequate treatment of this requires wide surgical debridement of devitalized tissue and closure with vascularized tissue. The latissimus dorsi myocutaneous flap was chosen.




The flap was marked on the posterior chest wall with demensions of 10 x 22 inches. The left of the photo marks the scapula with the right marking the iliac crest.





Dissection of the latissumus dorsi is best commenced anteriorly at the free border. Perforators are carefully coagulated as one dissects posteriorly. The muscle is then disinserted from its inferior origin along the iliac crest. The dissection around the scapula can be difficult. Thus, I find it easier to proceed from a superior to inferior direction by elevating the superior border of the muscle with double hooks and then proceeding inferiorly towards the scapula tip.


The serratus branch is then suture ligated and the pedicle is then followed proximally toward the axillae until the thoracodorsal artery and vein are identified.

The vascular leash on the latissimus is then checked to see if the muscle can be rotated freely anteriorly towards the chest wall.


A z-plasty can be completed across the axillae to allow free rotation anteriorly towards the anterior chest.



The latissimus dorsi muscle and skin paddle can extend across the midline in anterior chest wall defects.





The flap is then inset and closed over closed suction drains.