Ann Thorac Surg 2005;79:361-362
© 2005 The Society of Thoracic Surgeons
How to do it
Partial Right Internal Thoracic Artery Harvesting is Sufficient for Obtuse Marginal Branch Bypass Grafting
Jacob Zeitani, MDa,*,
Alfonso Penta de Peppo, MDb,
Ruggero De Paulis, MDa,
Paolo Nardi, MDa,
Antonio Scafuri, MDa,
Francesco Versaci, MDa,
Luigi Chiariello, MDa
a Division of Cardiac Surgery, Tor Vergata University, Rome, Italy
b Second University of Naples, Naples, Italy
Accepted for publication September 22, 2003.
* Address reprint requests to Dr Zeitani, Division of Cardiac Surgery, Tor Vergata University, European Hospital, Via Portuense 700, 00149 Rome, Italy
zeitani{at}hotmail.com
 |
Abstract
|
|---|
My colleagues and I present a method for revascularizing the left anterolateral myocardial wall by using an in situ left internal thoracic artery to left anterior descending coronary artery system and a short proximal segment (3 to 5 cm) of the right internal thoracic artery in Y fashion anastomosed to the in situ left internal thoracic artery to revascularize the obtuse marginal branches. With this technique the left ventricular anterolateral wall can be revascularized with both internal thoracic arteries, leaving a consistent residual blood supply to the right hemisternum.
|
Introduction
|
|---|
Evidence of better long-term patency of internal thoracic artery (ITA) grafts, compared with vein grafts [1], favors the increasing use of multiple grafts for myocardial revascularization. Despite the availability of various arterial conduits, the ITA (because of the diameter and quality of the wall) remains the ideal arterial graft [2]. The use of bilateral ITAs, either in situ or as a composite graft, might therefore be preferred in most patients. Revascularization of the anterolateral wall with both in situ ITAs has the advantage of maintaining 2 separate blood supplies to the myocardium, and no additional anastomoses are needed to create a composite graft. However, it requires harvesting the complete length of both arteries, does not always allow sequential revascularization of diagonal branches [3], and uses the distal portion of the ITA, which is known to have a suboptimal-quality wall [4].
My colleagues and I report a partial dissection of only the proximal right ITA (RITA), which provides a free arterial segment of adequate length to reach the obtuse marginal (OM) coronary artery when anastomosed in a Y fashion to the in situ left ITA (LITA).
|
Technique
|
|---|
After median sternotomy, the left parasternal endothoracic fascia is incised longitudinally, and the LITA and the adjoining veins are visualized. The artery is harvested in a skeletonized fashion for its entire length by using titanium clips and scissors to dissect collateral branches. Electrocautery is used only to expose the intercostal branches and to dissect fatty tissue. With the same technique, a proximal RITA segment (3 to 5 cm) is dissected from its origin to the second or third intercostal space; then both extremities of the dissected segment are clipped with titanium clips. The segment is removed and anastomosed as a free graft end to side to the proximal in situ LITA in a Y-graft configuration with 8-0 polypropylene sutures. The optimal site to anastomose the free RITA to the LITA is the point at which the in situ LITA crosses the pericardium border (Fig 1). We recommend that all length measurements be made with a full beating heart and without interrupting the ventilation. For the Y-graft anastomosis, the LITA is incised on the lateral side facing the left lung. At the time of distal anastomosis the OM is preferred first, followed by the LITA to the left anterior descending artery (LAD) and its branches (Fig 2).
View larger version (116K):
[in this window]
[in a new window]
|
Fig 1. Intraoperative image of a composite Y graft: a 4.5-cm proximal right internal thoracic artery (continuous arrow) is anastomosed to an in situ left internal thoracic artery (dotted arrow).
|
|
View larger version (118K):
[in this window]
[in a new window]
|
Fig 2. Intraoperative image of a composite Y graft: sequential graft with a proximal right internal thoracic artery segment to the first (*) and second (**) obtuse marginal branches. The in situ left internal thoracic artery is still to be anastomosed to the LAD.
|
|
To assess the residual blood flow to the right hemisternum, we performed a preoperative and postoperative right parasternal transthoracic color Doppler ultrasound (Sonos 5500 and a 7.5-MHz transducer; Hewlett-Packard, Andover, MA) to detect blood flow in the distal RITA before and after harvesting of the proximal segment.
|
Comment
|
|---|
Different surgical strategies have been developed during the last decade to achieve optimal myocardial revascularization for each patient. It is now well documented that the ITA graft compares favorably to other conduits because of vessel diameter, physiologic properties, long-term patency, and 1 surgical site [1, 2]. The use of in situ bilateral ITA does not always allow sequential revascularization of diagonal branches, and the distal segment of the ITA is not always optimal for performing anastomoses because of its small diameter and the arterial wall structure: in fact, Nataf and associates [4] reported that the distal internal mammary artery segment was not optimal as a conduit for bypass grafting because of its histologic characteristic. Indeed, the prevalence of the muscular tissue in the distal segment might cause spasm and favor the development of intimal hyperplasia. Their findings suggest that it may be beneficial to avoid the distal end of the ITA and to prefer the proximal elastic segment for coronary anastomosis.
We found that a short proximal segment of the RITA, as part of the composite Y graft, was sufficient to reach the first and even a second OM branch. On the basis of coronary anatomy and the number of coronary arteries that should be revascularized, the length of the free segment may vary from 3 to 5 cm. The operation program and strategy are based on preoperative coronary angiography evaluation; if coronary angiography is not clear enough regarding the OM topographic anatomy, intraoperative control of the OM branch position before RITA harvesting is recommended.
Bonchek and associates [5] described a technique in which a distal LITA segment is removed and used to construct a Y graft to reach a diagonal branch with unfavorable topographic anatomy to perform a sequential graft. The advantage of our strategy is in the use of a segment with a larger diameter and better histologic characteristics; this also permits reaching the OM branches.
It is hoped that the undissected distal segment of the RITA, which provides a residual blood supply to the right hemisternum, might reduce the incidence of wound complications, particularly in higher-risk patients. In fact, postoperative parasternal transthoracic color Doppler ultrasound detected a pulsatile reversed blood flow in the distal RITA stump, with similar flow velocities compared with the preoperative values (59 ± 13 vs 57 ± 7 cm/s, respectively; not significant).
This technique was performed in 20 consecutive patients with favorable coronary anatomy (coronary artery disease of the LAD and a first large OM branch). If necessary, a vein graft was used for the right coronary artery. The mean number of grafts per patient was 3 ± 0.7 (range, 2 to 5). In all patients, the in situ LITA was used to the LAD and the RITA segment to the OM branch. In 13 patients the LITA was also sequentially anastomosed to 1 or more diagonal branches, and in 2 patients the RITA segment was used as a sequential graft to the first and second OM branches. There were no deaths in this study group and no sternal wound complications. All patients experienced an uneventful recovery.
|
References
|
|---|
- Cameron A, Davis K, Green G, et al. Coronary bypass surgery with internal-thoracic-artery grafts—effects on survival over a 15-year period. N Engl J Med. 1996;334:216–219[Abstract/Free Full Text]
- Barner H. The continuing evolution of arterial conduits. Ann Thorac Surg. 1999;68(3 Suppl):S1–8
- Calafiore AM, Contini M, Vitolla G, et al. Bilateral internal thoracic artery grafting: long-term clinical and angiographic results of in situ versus Y grafts. J Thorac Cardiovasc Surg. 2000;120:990–998[Abstract/Free Full Text]
- Nataf P, Hadjiisky P, Bourbon A, et al. Morphometric and metabolic profile of the distal segment of the internal mammary artery: caution on its use for coronary anastomoses. Eur J Cardiothorac Surg. 1996;10:965–970[Abstract]
- Bonchek L, Burlingame M, Vazales B, et al. Maximal utilization of the internal mammary artery for coronary artery bypass grafting. Ann Thorac Surg. 1996;61:1848–1849[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
J. Zeitani, A. P. de Peppo, R. De Paulis, P. Nardi, A. Scafuri, S. Nardella, and L. Chiariello
Benefit of Partial Right-Bilateral Internal Thoracic Artery Harvesting in Patients at Risk of Sternal Wound Complications
Ann. Thorac. Surg.,
January 1, 2006;
81(1):
139 - 143.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
