Forequarter amputation is done for malignant tumors in the proximal part of the upper extremity (the shoulder or axillary region) when involvement of critical structures such as the neurovascular bundle in the axilla prevent a lesser procedure. Currently, this procedure is done rarely because the development of surgical techniques allowing limb-preserving resection and the availability of adjuvant modalities (neoadjuvant or adjuvant radiation therapy) have resulted in successful local control for most patients, obviating the necessity for radical surgery. However, there are patients in whom previous surgical and radiation treatments fail. These patients present with extensive tumor involvement of the brachial plexus and axillary vessels with an extremity that is immensely edematous, painful, and nonfunctioning. In the absence of metastatic disease, these patients can be considered for forequarter amputation.
Traditionally, an anterior approach (Berger) or a posterior approach (Littlewood) is used.4,5 In the anterior approach, a segment of the middle of the clavicle is removed, the subclavius muscle is divided and then the subclavian vessels are dissected, ligated, and divided. The dissection around the vessels can be tedious as the anatomic structures are crowded in a confined space and if inadvertent bleeding from the subclavian vein occurs, particularly its posterior wall, it can be difficult to expose and control because this vessel may not be adequately mobilized. In this approach, the vein is divided first while the artery still is open, resulting in blood loss within the extremity to be removed. The posterior approach divides the trapezius muscle, other muscles attached to the vertebral border of the scapula, the serratus anterior and latissimus dorsi, and as the scapula is mobilized off the chest wall, the trunks of the brachial plexus are serially ligated and divided exposing the subclavian artery, which also is ligated and divided, followed by ligation and division of the more anteriorly placed subclavian vein. In this approach, the posterior aspect of these vessels is well exposed but the anterior aspect remains obscure, as there is a considerable amount of tissue which is intact. In both of these techniques, the ligation of the vessels occurs where they cross the first rib approximately 3 cm from the thoracic inlet.
A technique of forequarter amputation is described which combines the two traditional techniques and is particularly applicable to patients requiring this operation after radiation to the axilla, which obliterates normal tissue planes. Ligation and transection of the subclavian vessels can be done at the thoracic inlet.
The patient is placed in a semilateral position with the affected shoulder, axillary region, and the upper extremity prepared and draped, the upper extremity being covered with a sterile stocking so that it can be manipulated as the procedure evolves. The incision starts at the medial end of the clavicle and extends over the medial half of the clavicle and then anteriorly deviates along the deltopectoral groove and around the axilla to the inferior angle of the scapula (Fig 1A). The posterior incision extends from the middle of the clavicle toward the acromion and the lateral border of the scapula to meet the anterior incision at the inferior angle of the scapula (Fig 1B). This incision may be modified according to the location of the tumor and its proximity to the skin surface. In the anterior portion of the incision, the dissection continues down to the fascia of the pectoralis major and a flap is developed through dissection on the surface of the pectoralis major, the latter being divided close to its sternal and costal origin, maintaining a sufficient distance away from the axilla where the tumor might be present (Fig 2). The pectoralis minor also is divided off its origin from the third to the fifth ribs. The dissection continues on the surface of the chest wall toward the axillary area. As the dissection approaches the area of the axilla, the serratus anterior is divided off its origin at the ribs, thereby maintaining a plane on the surface of the ribs. The posterior portion of the incision is deepened down to the investing fascia and a flap is developed posteromedially to the medial (vertebral) border of the scapula. The trapezius muscle is divided close to the upper medial angle of the scapula and then the levator scapulae and rhomboideus minor and major (Fig 3). The latissimus dorsi muscle is divided as the dissection continues around the inferior angle of the scapula. This frees the medial border of the scapula. As this border is lifted, dissection continues on the chest wall dividing the remaining attachments of the serratus anterior to the rib surface. The scapula is freed all the way around approaching the area of the lower neck. Then, a segment of the clavicle approximately 4 cm in length is removed by dividing the clavicle medially and laterally with a Gigli saw and the subclavius muscle is divided. The extremity is supported by an assistant so as to avoid undue traction on the subclavian vessels which might cause their disruption. From a posterior approach the omohyoid muscle is transected and the brachial plexus is exposed. The nerve trunks are serially ligated and divided as they issue between the scalenus anterior and medius at the base of the neck. This leaves the subclavian vessels to be ligated in the lower neck. Dissection around these vessels is begun. The subclavian artery and then the vein are ligated, suture-ligated, and divided at the thoracic inlet medial to the border of the first rib, permitting removal of the specimen. Suction drains are placed under the flaps and the incision is closed in routine fashion.
For tumors involving the skin of the axilla (Fig 4A), the incision is modified to include a fasciocutaneous flap from the deltoid area which is raised off the deltoid muscle based in its blood supply at the base of the neck (Figs 4A-B). The flap is developed to just above the clavicle, the acromion, and the spine of the scapula (Fig 4C). The dissection then in the deeper planes continues as with the common incision (Figs 1A-B) described previously. At the end of the operation, the flap may be trimmed if redundant or ischemic at the edge.
The technique of forequarter amputation usually involves early ligation of the subclavian vein and artery by removing a portion of the clavicle and dividing the subclavius muscle before any mobilization of the scapula has occurred. This anterior approach4,5 makes for a painstaking, tedious, time-consuming procedure as dissection with a right angle clamp is done slowly around these vessels to avoid any bleeding. Should bleeding occur, it may be difficult to control because these vascular structures have not been mobilized sufficiently for safe, expeditious ligation to be done. This is especially true for patients who have received radiation with obliteration of the tissue planes. Finally, the anterior approach requires first ligation of the subclavian vein, resulting in trapping of and loss of blood within the extremity as the subclavian artery still is open. Perhaps for these reasons, some authors have expressed a preference for the posterior approach.4 The posterior approach4,5 exposes and divides the brachial plexus and subclavian artery and vein before the division of the pectoral muscles and overlying skin and, therefore, may cause the same difficulties in control of bleeding, should bleeding occur during dissection around the great vessels, because the specimen has not been mobilized yet and freed all the way around the vessels. Furthermore, because the vessels have not been mobilized all the way around, one is not likely to attain a high ligation of them at the thoracic inlet, as achieved by our technique. For an even higher ligation of these vessels, transthoracic approaches have been reported.1
Prior mobilization of the scapula and division of the pectoral muscles and the clavicle in our technique with the extremity properly supported make for a more expeditious procedure which provides greater control because should bleeding occur during dissection around the subclavian vessels, it would be simple to place clamps across the neurovascular bundle, the only remaining connection to the trunk, and then remove the extremity safely. Prior mobilization of the extremity (by dividing its muscular attachments to the trunk) and at the end ligation and division of the subclavian vessels provides a greater opportunity to obtain a clear margin because the subclavian vessels can be ligated at the thoracic inlet 3 to 4 cm more proximal than the level (over the first rib) at which they are divided with the classic technique for forequarter amputation. The skin flaps, if created as described previously, are sufficiently ample to cover the chest wall. If a large portion of skin has to be sacrificed because of tumor involvement, a skin graft can be applied directly to the chest wall. The fasciocutaneous deltoid flap (Fig 5), however, can provide coverage for a skin defect in the axillary area. In the deltoid flap, the fasciocutaneous flap raised off the supraspinatus and infraspinatus muscles partakes in continuity so that the entire flap is broader (Fig 6) with a very broad base. For tumors located posteriorly, a fasciocutaneous flap off the pectoralis major and anterior half of the deltoid may be fashioned. In patients who are thought to require chest wall resection because of involvement by a tumor, the deltoid flap fashioned at the beginning of the operation can provide a solution to the problem of coverage of a full thickness defect of the chest wall, providing a seal for the pleural cavity, as previously described.6 Otherwise, a free flap with microvascular technique may be required.2,3
We have used this revised technique of forequarter amputation in six patients during the last 7 years and found it to be a substantial improvement over the anterior approach. None of the six patients (three with recurrent chondrosarcoma, one with regional metastatic melanoma to the axilla, one with an extensive soft tissue sarcoma of the shoulder, one with squamous cell carcinoma after surgery, radiation, and chemotherapy, and all with circumferential involvement of the brachial plexus) have had local recurrence during a followup of 8 months to 5.5 years. The patient with metastatic melanoma died 30 months later because of pulmonary metastases, whereas the other patients are disease-free. One of the patients with chondrosarcoma had resection of a solitary pulmonary metastasis. The survival of patients after forequarter amputation, as in other oncologic procedures, is primarily a function of the biologic aggressiveness of the tumor.
In the beginning of our experience we were using the anterior approach and had no problems or complications, but gradually and spontaneously shifted to the described technique. Therefore, in the procedure of forequarter amputation, we advocate first mobilization of the specimen and then ligation of the subclavian vessels as the final step in the procedure as being more expeditious and allowing a more generous proximal margin. This would be advisable for all patients, but is particularly useful for those who had prior radiation to the axilla and lower neck. The described technique is not a new technique, but simply a combination of the anterior and posterior approaches, leaving the high ligation and division of the neurovascular bundle to be done at the end of the procedure.
1. Fianchini A, Bertani A, Greco F, Brunelli A, Muti M: Transthoracic forequarter amputation and left pneumonectomy. Ann Thorac Surg 62:1841–1843, 1996.
2. Kuhn JA, Wagman LD, Lorant JA, et al: Radical forequarter amputation with hemithoracectomy and free extended forearm flap: Technical and physiologic considerations. Ann Surg Oncol 1:353–359, 1994.
3. Pelton JJ, Milbourn CT, Parsons III TW: Circumferential forearm fasciocutaneous free flap reconstruction of forequarter amputation/chest wall resection using simultaneous extra-anatomic revascularization (SEAR). Ann Surg Oncol 5:557–560, 1998.
4. Sim FH, Pritchard DJ, Ivins JC: Forequarter amputation. Orthop Clin North Am 8:921–931, 1977.
5. Tooms RE: Amputations of Upper Extremity. In Canale ST (ed). Campbell’s Operative Orthopaedics. Ed 9. St Louis, Mosby 550–560, 1998.
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6. Volpe CM, Peterson S, Doerr RJ, Karakousis CP: Forequarter amputation with fasciocutaneous deltoid flap reconstruction for malignant tumors of the upper extremity. Ann Surg Oncol 4:298–302, 1997.