|Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
| Almost all latissimus dorsi muscle flap transplantations may be performed using two teams, simultaneously dissecting the donor and recipient sites. When the latissimus muscle is used for scalp and skull coverage, the patient is placed in the lateral position with the recipient side up. If the muscle transplant is to the lower extremity, the choice of donor muscle depends on the recipient vessels to be used in the leg. Preoperative angiography is the key to this decision. If the posterior tibial vessels are to be used, the contralateral latissimus dorsi muscle is chosen. If the anterior tibial vessels are to be used, the ipsilateral latissimus is used as the donor muscle. The patient is again placed in the midlateral position with the appropriate side up. As noted, preoperative angiography is almost always mandatory for latissimus dorsi transplantation, particularly in patients with post-traumatic or postoperative defects, with or without irradiation.
A template of the recipient wound size should be made to allow estimation of the amount of latissimus dorsi muscle required.
Based on the preoperative angiography, the recipient vasculature should be chosen and the appropriate orientation of the flap determined. The dominant vascular pedicle of the latissimus dorsi consists of one artery and one vein, both of 2 mm caliber. Occasionally, the vein is even larger. In the head and neck region, the superficial temporal, facial, or occipital arteries are all satisfactory recipient vessels. Other branches of the external carotid system, such as the lingual or superior thyroidal artery in the neck, are also satisfactory. Because of the size of the thoracodorsal vein, the external jugular or facial veins are excellent recipient veins. The superficial temporal vein may be used, but its size and texture vary considerably. The necessity of choosing an alternate vein in this situation must be considered in the preoperative plan.
In the lower extremity, the posterior tibial or anterior tibial arteries are compatible with the thoracodorsal artery. The larger of the two venae comitantes with either of these arteries may be used as a recipient vein. The greater and lesser saphenous veins are also useful as recipient veins for latissimus dorsi, but good proximal drainage must be confirmed, particularly in severely injured legs.
Proper debridement of all unstable, infected, or necrotic soft tissue as well as appropriate sequestrectomies must be performed before muscle transplantation to the recipient site.
Because of the proprioceptive component of the thoracodorsal motor nerve to the latissimus, a regional sensory nerve such as the sural, saphenous, or superficial peroneal nerve may be used for microneurorrhaphy to the thoracodorsal nerve in an attempt to achieve protective sensation in the transplanted muscle. Sensory-to-motor anastomoses have been documented to regenerate experimentally, and several patients have been walking on sensory-neurotized muscles for years.14
Following are the key landmarks in the latissimus dissection.
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