Options for breast reconstruction have changed significantly over the past few decades, with an increase in free flap autologous reconstructions. The IM vessels are known to have significant advantages over those of the thoracodorsal vessels and are used almost exclusively (2
). It is often mentioned in speculation that the use of the IM vessels may be deleterious to patients who develop cardiac disease in that the preferred conduit choice for coronary bypass surgery (the IMA) has been sacrificed in the breast reconstruction. However, there has been minimal patient-physician interaction, or academic research, to consider whether microsurgical reconstruction using the IMA is sacrificing a major conduit for cardiac salvage, ultimately having an impact on patient morbidity and survival.
The present retrospective chart review of all microsurgical breast reconstructions performed at our institution from 2005 to 2009 shows that two of 81 patients identified experienced postoperative myocardial infarctions. Flap loss and other complication statistics were comparable with previously published figures. In the two patients who experienced cardiac complications, additional investigations revealed significant triple vessel coronary artery disease, normally mandating multivessel coronary artery bypass surgery using the IM vessels for the optimal long-term relief from angina and, thus, conferring superior survival benefits. Because the IM vessels had been used for breast reconstruction, these patients underwent angioplasty and stenting instead. Angioplasty does not offer the same survival and anginal-free state as multivessel coronary artery bypass. In fact, percutaneous coronary intervention has never been proven to have any life-prolonging benefits (8
). Their treatment course may have ultimately been different had they not undergone breast reconstruction using IM vessels. While the small sample size of the breast reconstruction population in the present study may over- or underestimate the true risk or incidence, it certainly raises the concern that the issue of use of the IMA in breast reconstruction warrants more attention.
With regard to choice of recipient vessels in free flap breast reconstruction, the main decision is between the use of thoracodorsal and IM vessels. The IMA originates from the subclavian artery, runs ventral to the parietal pleura and transversus thoracis, and dorsal to the costal cartilage. The IMA divides into the superior epigastric artery and musculophrenic artery at the sixth intercostal space (9
). The main benefits of using the IM vessels include medial flap positioning and avoidance of lateral fullness; the ability to use a flap with a shorter pedicle; consistent location of large-calibre vessels; and lack of a scarred bed with potentially unreliable recipient vessel flow, which can occur in delayed reconstruction following axillary dissection (2
). Drawbacks of the IM site include its unpredictable venous anatomy, the fragility of the IM veins and the risk of pneumothorax (11
). Movement during respiration can complicate microsurgical anastomosis, but may improve venous outflow via the negative pressure during inspiration (2
The diameter of the IMA at the level of the fourth rib is often 2 mm, and maintains a reasonable diameter throughout its length (1 mm to 2.5 mm) (9
). In contrast to the IMA, the venous anatomy is more variable. Commonly described preparation of the IM vessels for microvascular anastomosis includes removal of the medial portion of the third costal cartilage (13
). The third rib is often chosen primarily for venous diameter; however, anastamosis has been described anywhere from the second to the fifth intercostal space (14
). Most often (94%) there is a single, medially positioned, comitant vein (9
). Hefel et al (9
) reported that the IMA and IM vein are suitable for microsurgery at the level of the fourth rib, which certainly, was supported by several cases in this series. It is not currently known whether the use of the IMA at any level for breast reconstruction is compatible with future use in coronary artery bypass surgery; however, intuitively, one would expect that the longer the length of virgin vessel, the more likely the possibility of future use for coronary bypass.
Ischemic heart disease remains the most common cause of death for women in developed countries. Despite current trends in percutaneous coronary intervention and the recent popularity of drug-eluting stents, the strongest, most robust evidence with the longest follow-up still fervently supports coronary artery bypass surgery as the gold standard therapy for left main coronary artery disease, triple vessel disease and two vessel disease with proximal left anterior descending artery involvement (5
). Evidence regarding the superior patency of IMA grafts over any other conduit or intracoronary revascularization mechanism is clear. Recent studies have suggested patency rates of between 95% and 99% at 10 years (6
), and 88% patency at 15 years (8
). Alternatively, saphenous vein grafts have an expected patency rate of approximately 50% to 60% at 10 years. The most persuasive information about the left IMA graft is that, unlike saphenous vein grafts or coronary stents, the left IMA-left anterior descending bypass is the only form of coronary revascularization that has been associated with improved early and late patient survival (4
). In general, most cardiac surgeons reserve bilateral IMA grafting for young, nondiabetic patients with an appropriate body habitus.