Coronary artery surgery using inverted internal mammary artery

Utilizing the Retrograde Flow of Internal Mammary Vessels as a Donor Pedicle

Introduction  The aim of this study is to assess the results of retrograde flow of internal mammary artery and vein (IMA/V) as a donor vessel for free flap microvascular anastomosis (MVA). This need arises with bipedicle deep inferior epigastric perforator (DIEP) flaps, when all four zones with extra fat need to be harvested for unilateral breast reconstruction coupled with poor midline crossover of circulation naturally or because of midline scar. Large anterolateral thigh flaps for chest wall cover, with multiple perforators from separate pedicles, also need supercharging. This needs an additional source of donor vessels, antegrade IMA/V being the first one.

Materials and Methods  Retrospective study of microvascular breast reconstruction using retrograde internal mammary donor vessels.

Results  Out of 35 cases, 20 cases had distal IMA/V, with retrograde flow, as donor vessel for second set of arterial and venous anastomosis. In two cases, retrograde IMA/V was used for the solitary set of MVA. In remaining 13 cases, either retrograde IMA or V was utilized either as a principal or accessory donor. No flap was lost. Venous and arterial insufficiency happened in one case each, both were salvaged. Two cases developed partial necrosis, needing debridement and suturing. One case developed marginal necrosis. Only one case developed fat necrosis with superadded infection on follow-up.

Conclusion  Distal end of IMA and IMV on retrograde flow is safe for MVA as an additional or sole pedicle. It is convenient to use being in the same field. It enables preservation of other including thoracodorsal pedicle and latissimus dorsi flap for use in case of a complication or recurrence.

Complete Myocardial Revascularization in Severe Arteriopathy

Multivessel coronary revascularization was successfully performed in a 75-year-old man with severe atherosclerosis of the ascending aorta and aortic arch, significant stenoses in the right subclavian, innominate, and aortoiliac arteries, renal impairment, and conduit shortage, by combining the beating-heart approach with aorta-sparing pedicled arterial and venous grafts. No postoperative complications were encountered.

Retrograde internal mammary artery as coronary bypass. A prospective study with postoperative angiographic evaluation

Although the internal mammary artery (IMA) as a coronary graft offers better long-term patency than the saphenous vein, a factor limiting its use has been the length of the artery's pedicle. In an attempt to overcome this limitation, we evaluated the use of retrograde right IMA in a prospective study. In ten patients scheduled for routine coronary artery bypass surgery, bilateral IMA grafting was used, the left IMA in routine fashion, but the right IMA dissected from the level of the first rib, cut there and placed as an inverted graft. Three months postoperatively the patients were clinically evaluated with stress exercise test (n = 10) and coronary angiography (n = 9). No patient had recurrence of angina. Angiography revealed patency of the retrograde right IMA graft in six of nine patients. On the basis of these data we do not recommend routine use of retrograde IMA.

Flow capacity of the human retrograde internal mammary artery: surgical considerations

The diastolic flow of the retrograde internal mammary artery (IMA) was calculated in 30 patients and compared with the expected coronary flow of the left ventricle and that of specific branches. Arterial pressure and free flow were measured in the proximal and distal IMA as well as in the superior epigastric and musculophrenic arteries. Systolic and mean arterial pressure were significantly higher in the proximal IMA than in any other site, but diastolic pressure was comparable. Overall and diastolic antegrade IMA flows (77 +/- 6 and 44 +/- 3 mL/min) were significantly greater than the retrograde flows through the distal IMA (18.5 +/- 2 and 11.5 +/- 1 mL/min), musculophrenic artery (13.3 +/- 1 and 7.9 +/- 1 mL/min), and superior epigastric artery (5.3 +/- 0.4 and 3.1 +/- 0.2 mL/min). Only patient-size-related variables correlated significantly with retrograde IMA flow. Diastolic retrograde IMA flow represented 8.5% +/- 0.6% of the expected left ventricle coronary flow and in 12 patients (40%) was greater than the expected flow of at least one posteroinferior coronary artery. Based on these data, the retrograde IMA may adequately perfuse the posterior descending or other posterolateral coronary branches in select patients. Previous measuring of the retrograde flow is mandatory.

Retrograde flow in the internal mammary artery

Thirty-two patients undergoing coronary artery bypass grafting were studied to evaluate retrograde flow in the internal mammary artery (IMA). The left IMA pedicle was prepared in routine fashion from the level of the first rib superiorly to just distal to the IMA bifurcation. Following cannulation for cardiopulmonary bypass but before institution of extracorporeal circulation, the IMA was divided 5 mm proximal to its bifurcation and allowed to bleed freely. The flow from each end was then measured by allowing the segment to bleed for 30 seconds. The mean antegrade flow was 73 +/- 34 ml/min, and the retrograde flow was 25 +/- 17.2 ml/min. The difference between the flows was significant (p less than 0.05). Based on these data we do not recommend the retrograde IMA technique as a primary form of revascularization of the myocardium. In selected circumstances it may be used if adequate retrograde flow is demonstrated before constructing the anastomosis.