Intraoperative Evaluation of Blood Flow in the Internal Mammary or Thoracodorsal Artery as a Recipient Vessel for a Free TRAM Flap

Abstract

Although the free microvascular transverse rectus abdominis musculocutaneous (TRAM) flap is in routine use for breast reconstruction, little is known of its hemodynamics. The purpose of this study was to determine whether any differences exist when the free TRAM flap is anastomosed to the thoracodorsal or internal mammary vessels. The study comprised 25 patients receiving a free TRAM flap for breast reconstruction. The thoracodorsal vessels were used as recipients in 21 patients and the internal mammary vessels were used in 4 patients. Blood flow rate was measured directly in the donor and recipient arteries, and after anastomosis by a transit-time ultrasonic flowmeter (CardioMed). Two- and 3-mm probes were used. The blood flow rate in the donor artery (deep inferior epigastric) before flap dissection was 11 +/- 6 ml per minute (mean +/- standard deviation). The rate was significantly (p < 0.05) lower (5 +/- 3 ml per minute) in the recipient thoracodorsal artery than in the donor, but after transplantation it increased to 14 +/- 5 ml per minute (p < 0.05), attaining the same value as the donor artery. The blood flow rate in the intact internal mammary artery was significantly higher (25 +/- 10 ml per minute) than in the donor and thoracodorsal arteries, but after anastomosis it dropped to the same value (12 +/- 3 ml per minute; p < 0.05) as the donor artery. The intake of blood in TRAM flaps supplied by the intemal mammary artery seems to be no greater than that in free flaps anastomosed to thoracodorsal vessels, although the flow in the internal mammary artery was much higher. The authors concluded that the blood supply in a free TRAM flap is independent of the flow in the recipient artery and that thoracodorsal vessels, although often in a scarred bed and radiated, are as suitable for anastomosing a free TRAM flap as are internal mammary vessels.

Avoidance of complications after the use of deep inferior epigastric perforator flaps for reconstruction of the breast

“…This procedure reduces the Table I The thoracodorsal artery has been reported to have a lower flow rate than the mammary artery [10,11]. According to Lorenzetti et al there is no difference in flow rate between these vessels after anastomosis of free TRAM flaps [10]. However, we know of no data that describe the venous flow rate in these vessels, which could explain the higher rate of venous complications in the first 25 patients in our study.…”

“…It might also be explained by the fact that prophylactic anastomosis of the superficial epigastric vein was not used at all in the first 25 patients, but in three of the second 25 patients (Table II). This procedure reduces the Table I The thoracodorsal artery has been reported to have a lower flow rate than the mammary artery [10,11]. According to Lorenzetti et al there is no difference in flow rate between these vessels after anastomosis of free TRAM flaps [10].…”

The Internal Mammary Artery and Vein as Recipient Vessels for Microvascular Breast Reconstruction:

“…15,16 The blood flow rate of the IMA ranges from 15 to 35 mL/minute (mean, 25 mL/minute) and the blood flow rate of the thoracodorsal artery ranges from 2 to 8 mL/minute (mean, 5 mL/minute. 17,18 These anatomic and physiologic studies have provided the basis and support for use of the IMA as a recipient vessel for free tissue transfers. These blood flow rates are also responsible for the superiority of the IMA over the saphenous vein graft for CABG.…”

Achieving autologous breast reconstruction for breast cancer patients in the setting of post-mastectomy radiotherapy

“…For these reasons, as well as good exposure of these vessels during axillary dissection, they are frequently the preferred recipient vessels in the setting of immediate reconstruction and axillary dissection [14]. The internal mammary vessels are often employed as recipient vessels in view of their impressive calibre, however there is no evidence to suggest improved outcomes when this vessel is selected [15,16]. Both vessels however, may be adversely affected following radiotherapy.…”