Source Plastic & Reconstructive Surgery Volume: 98 Number: 4 Sept. 1996

The Internal Mammary Artery and Vein as a Recipient Site for Free-Flap Breast Reconstruction: A Report of 110 Consecutive Cases

Charles L. Dupin, M.D., Robert J. Allen, M.D., Cynthia A. Glass, M.D., and Ross Bunch, M.D.
New Orleans, La.

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Discussion

The most common recipient site for free-flap breast reconstruction is the subscapular system. Because of a number of problems we encountered using this recipient site, we became interested in revisiting the internal mammary vessels.

This paper reports the use of the internal mammary artery and vein as a recipient site in 110 consecutive cases of breast reconstruction in 87 patients. We also report the technical details of recipient-vessel dissection and vessel size in our series. Complications encountered in the series are discussed, and the advantages of using the internal mammary vessels are enumerated. Our experience of a 99 percent successful flap transfer rate supports the reliability of these recipient vessels in breast reconstructions. (Plast. Reconstr. Surg. 98: 685,1996.)

The internal mammary vessels are attractive recipient vessels for free-flap breast reconstruction. Shaw,1 in his original article describing the free gluteal musculocutaneous flap for breast reconstruction, utilized the vessels in the fifth intercostal space. He reported that he could only use the internal mammary vein in three of eight cases. He found that the internal mammary vein was very small at the level of the fifth rib and matched poorly with the large (and short) superior gluteal vein, which averaged 3 mm in diameter. He later reported2 that in 75 percent of the cases he was able to use the internal mammary vein, presumably by using a more proximal rib level.

The development of the free transverse rectus abdominis musculocutaneous (TRAM) flap with its longer pedicle allowed the use of the subscapular system, and the internal mammary system was largely abandoned. Feller3 in 1994 cautioned, "We do not recommend the use of the internal mammary artery and vein as recipient vessels owing to their unpredictable quality. Although the artery might be adequate as a recipient vessel, the vein is most often found to be inadequate as a recipient vein so that the external jugular or the cephalic vein . . . is pulled through subcutaneously into the dissected chest pocket. This is time consuming and is disadvantaged by the addition of scars on either the neck or the upper arm."

Although we used the subscapular system as a recipient site in our 44 free TRAM flaps and our first perforator flaps, we noted the following problems:

1. In secondary reconstructions (especially in radiated cases), the dissection of axillary vessels was very difficult.
2. The thoracodorsal artery frequently was small (less than 2 mm) and sometimes was found to have insufficient flow, necessitating anastomosis to the circumflex scapular artery more proximal in the subscapular system.
3. Medial placement of the breast mound was restricted, and lateral fullness of the flap was a common problem.
4. Several patients sustained injury to the thoracodorsal artery inadvertently during the axillary dissection, rendering its use impossible.
5. Two patients avulsed the arterial anastomosis with shoulder motion (one was salvaged).
6. Brachial plexus symptoms were seen (although transient), and some patients developed a stiff shoulder resulting from the restriction of shoulder action. These patients required therapy and/or injection.
7. Anastomosis in the axilla is technically difficult for the assistant because he or she is operating across the chest.

Development of the deep epigastric perforator flap4,5 and the superior gluteal artery flap6 7 encouraged us to revisit the internal mammary vessels as a recipient site. Between May of 1993 and February of 1995 we have used these vessels exclusively in a series of 110 flaps. We hoped to be able to solve some of the problems noted above and to determine if the internal mammary vessels were reliable recipient vessels for these perforator flaps.

Patients and Methods

We performed 110 flaps on 87 patients. Most were reconstructions following modified radical mastectomy, but a few were implant replacement procedures. Seventy-four of the flaps were deep epigastric perforator flaps, and 32 were superior gluteal artery flaps. Two inferior gluteal artery flaps and two lateral thigh perforator flaps completed the series. Eighty-seven of the flaps were for immediate reconstruction, and 23 were for delayed reconstruction. Ten patients had simultaneous bilateral deep epigastric perforator flaps, 3 patients underwent simultaneous bilateral superior gluteal artery flaps, and 1 patient underwent bilateral simultaneous lateral thigh perforator flaps for breast reconstruction.

Currently, our patients are discharged on the third postoperative day, with average length of stay since May of 199370f 4 days. Operative time averaged 5 hours for unilateral reconstructions and 9 hours for bilateral reconstructions.

The flap survival rate was 99 percent with one flap failure, not related to the recipient vessels. Successful repeated reconstruction with the internal mammary recipient vessels was achieved with a second free perforator flap using the ipsilateral internal mammary vein at the second rib level.

Technical Details

The size of the internal mammary vessels at the second, third, and fourth interspaces was reported recently by Clark et al.8 They focused on the anatomy of the internal mammary veins and reported that there were veins of at least 3 mm in diameter at the second interspace in 100 percent of the cadaver studies. They also found that veins of this diameter were found at 33 percent of the left and 100 percent of the right third spaces. In their study they found no veins with a diameter greater than 3 mm at the level of the left fourth intercostal space, although 60 percent of the right fourth intercostal spaces had veins greater than 3 mm.

Our measurements of vessel diameter prior to anastomosis were done with the standard "background grid" (Table I).

The recipient vein sizes were appropriate for the average size of the flap vessels (Table II). The veins were consistently more variable and smaller at the level of the fourth rib, especially on the left, and we recommend use of the vessels under the third rib (Fig. 1).

Meticulous dissection of the vessels is critical (Fig. 2). Branches to the intercostal muscle should be dissected carefully, ligated with small ties, and not coagulated. It is essential not to avulse these branches in order to avoid injuring these fragile veins. Every attempt should be made to expose the vessels from the top of the lower rib to the bottom of the upper rib. The intercostal muscle should be removed. Usually 4 cm of a vessel is exposed and prepared for the anastomosis.

Internal Mammary Vessels
(level of 3rd rib)

FIG. 1. Size match of vessels based on measurements in our series (n = 110).

It is also important to allow the vessels to rest and rewarm for 20 minutes after dissection to allow maximum dilation of the veins. The veins are quite distensible (Fig. 3). Great care also must be taken to prevent twisting during the anastomosis of these long pedicles. The respiratory motions can be troublesome. We ask the anesthetist to hand ventilate the patient during the anastomosis and to occasionally hold the respiration for placement of the sutures.

Prior to insetting the flap, the skin island is marked corresponding to the point at which the perforator enters the undersurface. This reduces confusion about which vessel is monitored.

Postoperatively, we monitor the flaps with Doppler ultrasound for artery inflow. Flap color is monitored for outflow, as is temperature.

Results

Overall flap survival was 99 percent (109 of 110). However, two early patients in the series required abandonment of the internal mammary, vein. The vein was injured during dissection because of inappropriate avulsion or coagulation of delicate branches. One patient required a vein graft to the thoracodorsal vein, and a second was switched to the subscapular system. Thus the internal mammary vessels were used successfully in 108 of 110 reconstructions (98 percent of patients). Flow from the internal mammary artery was always brisk and more than adequate. We did not see any spasm in this vessel. While the dissection is demanding, it is relatively straightforward. We have had no stiff shoulders or stretching injuries to the brachial plexus. None of our patients were restricted in arm motion following surgery. One patient was discharged on the first postoperative day and many on the second day. There was no significant pain or instability related to resection of the rib cartilage.

Advantages Over Using the Thoracodorsal Vessels

Breast mound placement can be as medial as desired, and lateral fullness is rarely encountered, decreasing the need for secondary flap revision. The dissection in delayed reconstruction and in irradiated cases is straightforward. Seven patients in our series had undergone preoperative radiation, and no radiation effect to the internal mammary vessels was observed. In bilateral reconstructions, the two internal mammary vessels can be exposed simultaneously with minimal repositioning of the patient or the operating microscope. With some tilting of the operating table, the first assistant's position at the microscope is excellent, allowing easy tying and suturing from either side of the table.

FIG. 2. Typical anatomy of vessels at third rib

FTC. 4. Markings for superior gluteal artery perforator

FIG. 5. Mastectomy defect with internal mammary artery markings

 

FIG. 3. Internal mammary vein-superior gluteal vein anastomosis

FIG. 6. Postoperative result

Complications

Seven patients were returned to the operating room with postoperative problems. One patient developed mixed venous/arterial insufficiency that was delayed several hours in diagnosis. She had been on large doses of selfprescribed ergotamine preparations prior to surgery for vascular headaches. She did have a second flap using the ipsilateral second rib internal mammary vessels to salvage the reconstruction. Three patients developed venous insufficiency as a result of twisting of the flap pedicle, requiring revision of the pedicle position and reanastomosis of the vein. Two patients developed a hematoma under the flap that had to be evacuated. One patient had to be returned for arterial anastomotic problems, and one patient required surgery for a gluteal hematoma. We had one small pneumothorax that was treated conservatively and resolved with no therapy.

Conclusions

We have found the internal mammary system very reliable for free-flap breast reconstruction (Figs. 4, 5, and 6). Because of the longer pedicle and the ability to choose an appropriate venous match, the internal mammary vessels are ideal for the perforator flap.

Utilizing the traditional gluteal myocutaneous flap still presents a difficult problem because of the size and shortness of the pedicle and the availability of only the main superior gluteal vein. Although we have always dissected the perforator out of the muscle, Shaw9 has recently begun dissecting the pedicle away from the underside of the muscle in order to obtain more length and a better match.

In our experience, a satisfactory size match is reliably found between the internal mammary artery and vein at the third interspace with the inferior epigastric and superior gluteal vessels. The internal mammary system should be brought back into the armamentarium for free flap breast reconstruction.

Charles L. Dupin, M.D.
120 Meadowcrest Street
Suite 300
Gretna, La. 70056

References

Shaw, W. W. Breast reconstruction by superior gluteal microvascular free flaps without silicone implants. Plast. Reconstr. Surg. 72: 490, 1983.

Shaw, W. W., and Ahn, C. Y. Microvascular free flaps in breast reconstruction. Clin. Plast. Surg. 19: 917, 1992.

Feller, A. M. Free TRAM: Results and abdominal wall function. Clin. Plast. Surg. 21: 223, 1994.

Allen, R. J., Dupin, C. L., and Class, C. A. Breast Reconstruction Using the Deep Inferior Perforator Flaps. Presented at the Annual Meeting of the American Society of Plastic and Reconstructive Surgeons, New Orleans, Louisiana, 1993.

Allen, R. J., and Treece, P. Deep inferior epigastric perforator flap for breast reconstruction. Ann. Plast. Surg. 32: 32, 1994.

Allen, R. J., Dupin, C. L., and Glass, C. A. Breast Reconstruction with Gluteal Artery Perforator Flaps. Presented at the Annual Meeting of the American Association of Plastic Surgeons, St. Louis, Missouri, 1994.

Allen, R. J., and Tucker, C., Jr. Superior gluteal artery perforator free flap for breast reconstruction. Plast. Reconstr. Surg. 95: 1207, 1995.

Clark, C. P., Pittman, C. E., Rohrich, R.J., and Robinson, J. An Anatomical Study of the Internal Artery and Vein. Presented at the Annual Meeting of the American Society for Reconstructive Microsurgery, Marco Island, 1995.

Shaw, W. Breast Reconstruction with Gluteal Free Flaps. Presented at the Annual Meeting of the American Society for Plastic and Reconstructive Surgeons, San Diego, Calif., 1994.

From the Section of Plastic Surgery at the Louisiana State University School of Medicine. Received for publication May 30, 1995; revised September 25, 1995.