Introduction
The internal thoracic artery (ITA), namely, the left ITA (LITA), is arguably the most vital conduit for the conduct of coronary artery bypass grafting (CABG) due to its superior long-term patency and mortality benefit. Harvesting of the ITA must be done in an efficient and atraumatic fashion to preserve full functionality and longevity of the conduit. This is especially true where the LITA will be used in composite grafting configurations and will serve as the main conduit for other conduits to branch form. Skeletonization of the ITA requires even more meticulous technique as there is less fascia to manipulate on the ITA.
ITA harvest requires excellent surgical exposure while aiming to distort a patient anatomy as minimal as possible. Aggressive manipulation of a patient anatomy with excessive sternal retraction can lead to consequences such as postoperative pain, respiratory insufficiency, rib fractures, sternal fractures, costochondral dislocation, and neuropathy (e.g., brachial plexus injury) . Great care must be taken when exposing the ITA to prevent these complications. Prior to the advent of retractors created for ITA harvest, an assistant provided upward retraction with sternal rakes or similar instruments . Fortunately, there are now a variety of sternal and ITA retractors that provide adequate exposure of the ITA for safe and expedient harvest.
This chapter will cover the most common retractors for the harvest of the ITA through median sternotomy. Minimally invasive options are covered more in depth in other chapters. Advantages and disadvantages of each retractor will be discussed and are summarized in Table 5.1 . It should be noted that although there are several retractors available, there is limited evidence for using one retractor over another. Retractor use should be adapted to each clinical situation taking into account patient factors and clinical context. Furthermore, the use of each retractor is often institution and surgeon specific.
| Retractor | Advantages | Disadvantages |
|---|---|---|
| Bugge retractor |
|
|
| Couetil retractor and other “rake” retractors |
|
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| Pittman retractor |
|
|
| Rultract retractor |
|
|
Bugge retractor
The Bugge retractor was first described by Dr. Bugge in 1990 ( Fig. 5.1 ) . It is a modification of a standard median sternotomy retractor to allow for angulated and asymmetrical retraction of the ITA. Each side of the retractor has a mounted tilted blade that allows for one side of the sternum to be lifted while the other side of the sternum is simultaneously depressed. There is also an adjustable mount on the lifted portion of the sternal retractor to adjust the angle of retraction. As the screw is tightened, the sternum and rib on the side of the ITA are pushed down and angled toward the surgeon to allow for improved visualization. Caution should be used when adjusting the angle of retraction with this method as it can place excessive angulated stress on the ribs, increasing the risk of fracture and costochondral separation or dislocation.
