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MMCTS (November 29, 2005). doi:10.1510/mmcts.2004.001008
Copyright © 2005 European Association for Cardio-thoracic Surgery

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Luca Weltert
Francesco Patanè
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Right arrow Revascularization of ischemic myocardium
 

Procedure


Internal mammary artery

Antonio M. Calafiorea,*, Luca Welterta, Michele Di Maurob, Guglielmo Actis-Datoa, Angela L. Iacòb, Paolo Centofantia, Michele La Torrea and Francesco Patanèa

a Department of Cardiac Surgery, S Giovanni Battista Hospital, University of Turin, C.so Dogliotti 16, 10126 Turin, Italy
b Department of Cardiac Surgery, University "G D'Annunzio", Chieti, Italy

* Corresponding author: * Tel.: +39-011-633 5514; fax: +39-011-633 5512. E-mail: calafiore{at}unich.it


   Summary
Top
 Summary
Introduction
 Surgical strategies
 Surgical technique
 Results
 References
 
The internal mammary artery (IMA) has been already used in some pioneering experiences since the middle of last century but it became the graft of choice only in the 1980s, after widespread angiographic and clinical demonstration of its superiority over the saphenous vein graft (SVG). The use of both mammary arteries was then explored in order to achieve better long-term results when compared to single IMA and SVG. The IMA can be harvested pedicled or skeletonized and used as an in situ graft or as a source for composite graft (Y-graft, lengthened graft). When the bilateral internal mammary artery (BIMA) is grafted in situ, the left internal mammary artery (LIMA) is generally used for the left descending artery (LAD) and the RIMA for the right coronary artery (RCA), or for the lateral wall, usually going through the transverse sinus. In the case of Y-graft, the left coronary system is more frequently chosen as the target site of revascularization. Our experience shows that: (1) The use of IMA provides better 15-year clinical results when compared to SVG. (2) The use of BIMA in patients younger than 75 years can produce higher 10-year freedom from cardiac-related events than the single one, even in diabetic patients.

Key Words: Bilateral mammary artery • Internal thoracic artery • Y-graft


   Introduction
Top
 Summary
 Introduction
Surgical strategies
 Surgical technique
 Results
 References
 
The internal mammary artery (LIMA) was used for indirect myocardial revascularization by Vineberg in 1946 [1]. About 20 years later, Kolessov performed the first LIMA-LAD direct anastomoses on the beating heart [2]. Over the following years, many surgeons reported their experiences using the internal mammary artery as coronary graft. At the end of 1960, Favaloro [3] introduced the saphenous vein for myocardial revascularization, which resulted in easier to harvest and to graft. This limited the diffusion of the IMA until the mid-1980s, when the angiographic and clinical superiority of the left internal mammary artery over the saphenous vein graft (SVG) [4,5,6] was clearly demonstrated.

The possibility that by increasing the number of arterial anastomoses, long-term results could be even better, was then explored. The first arterial conduit that could be added to the LIMA was the right internal mammary artery (RIMA) which, of course, presented characteristics similar to the LIMA [7,8].

However, some drawbacks limited the widespread utilization of the bilateral internal mammary artery (BIMA) grafting:

  • the increase of deep sternal wound problems, especially in diabetic patients;
  • the reduced length of the RIMA, that limited its utilization as in situ graft;
  • the low patency rate (similar to the SVG one) when the RIMA was grafted to the RCA, the nearest target coronary vessel;
  • the longer operative time.

The use of both mammary arteries rather than the single one, as a determinant of better early and late outcome, remained uncertain for a long time [9,10] until the end of 1990, when higher freedom from death [11,12], cardiac death [13] and cardiac-related events [13,14,15] in the case of BIMA grafting were reported.

Because of these evidences, many surgeons have been reluctant for a long time to use BIMA grafting, because of a higher risk of deep sternal problems. Recently, IMA harvesting as a skeletonized conduit [16], was shown to lower the risk of sternal wound problems in patients who receive BIMA grafting. Also in diabetic patients this strategy was demonstrated to be beneficial.

Anatomy
The IMA arises from the subclavian artery, above and behind the sternal end of the clavicle. In 70% of cases the LIMA originates alone, whereas in 30% it arises from a common trunk with other arteries (thyreocervical trunk, suprascapular artery, inferior thyroid artery) (Schematic 1). In an angiographic study, our group found that the LIMA can originate together with other arteries in more than 1/3 of cases (Photo 1). In an echographic study, the RIMA arises alone from the subclavian artery in 95% of cases whereas in the remaining 5% it originates from a common trunk with other arteries [17].



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  		Schematic 1 Internal mammary artery can have different origins: (a) from the thyrocervical trunk; (b) together with the suprascapular artery; (c) together with the inferior thyroid artery. (Reprinted from [18] with permission of Mosby.)

 


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  		Photo 1 Angiographic demonstration of common origin of the internal mammary artery with the inferior thyroid artery and suprascapular artery. (Reprinted from [19] with permission of Elsevier Inc.)

 
In 95% of the cadavers the IMA descends antero-medially behind the internal jugular vein and the brachiocephalic vein (Schematic 2). Passing behind the first costal cartilage, close to the phrenic nerve, it goes down into the thorax. The artery descends vertically 1 cm lateral to the sternal border, behind the first six costal cartilages. The IMA is separated from the pleura at the second or third costal cartilage by a strong layer of endothoracic fascia and inferiorly by the transversus thoracis muscle. It is accompanied by two mammary veins, which ascend medially and laterally, respectively [18,19].



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  		Schematic 2 Internal mammary artery descends antero-medially behind the internal jugular vein and the brachiocephalic vein. (Reprinted from [18] with permission of Mosby.)

 
Both phrenic nerves cross the ITAs anteriorly in 54% of the cases and posteriorly in 14%. The left phrenic nerve crosses the artery anteriorly and the right phrenic nerve posteriorly in 12% of the cases, whereas the reverse relationship was observed in 20%.

The lateral costal branch is present in 15% of the cases, single side in 10%, and both sides in 5% (Photo 2). All the arteries that sometimes have a common origin with an IMA and the lateral costal branch originate from the first centimeters of the IMA and are never ligated, as the subclavian vein lies over them.



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  		Photo 2 Angiographic demonstration of the presence of the lateral costal branch. (Reprinted from [19] with permission of Elsevier Inc.)

 
The ITA ends as a bifurcation in 93% of the cases (superior epigastric and musculophrenic arteries), and as a trifurcation in 7% (a third branch, the diaphragmatic branch adds to the previous ones) [17].

Internal mammary artery and sternal vascularization
Sternal vascularization is provided by six different types of vessels (Schematic 3), five arising from the IMA and one running close to it. Three out of six can potentially act as conduits for collateral flow to the sternum.



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  		Schematic 3 Sternal vascularization is provided by six different types of vessels. (Reprinted from [20] with permission of Elsevier Inc.)

 
The three non-collateral branches are: sternal, intercostal, and perforating. They typically arise, respectively, from the medial, lateral, and anterior aspects of the IMA. Noncollateral vessels outnumber collateral vessels by approximately 5:2.

The three collateral branches are: sternal/intercostals (S/I) from the anterior or lateral aspect of the IMA; sternal/perforating (S/P) from the anterior or medial aspect of the IMA; and, rarely, a persistent posterior intercostal artery.

While the first two branches arise from the IMA as a common trunk, dividing then to supply both the sternum and an adjoining area, the intercostal space (S/I) or the anterior soft tissue (S/P). The third one runs bypassing the ITA without anastomosing with it.

After mobilization of the IMA, collateral blood flow could reach the sternum by way of an S/I or S/P branch. For this to occur, the point of division of the S/I or S/P branch into its sternal and intercostals (or perforating) sub-branches must be protected from surgical damage. The length of the common trunk ranges from 1 to 12 mm for the S/I branches), with a mean of 4.1 mm (Schematic 4A), and from 0 to 16 mm for the S/P branches. The distance is less than 5 mm in 67% of cases and less than 10 mm in 95% of cases (Schematic 4).



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  		Schematic 4 Presumed route of collateral flow to the sternum after mobilization of the internal thoracic artery: (A) via sternal/perforating branches and (B) via sternal/intercostal branches. (Reprinted from [20] with permission of Elsevier Inc.)

 
Harvesting of the IMA as a pedicle reduces blood flow of the sternum in the postoperative period (Photo 3). To avoid it, IMA has to be harvested in a skeletonized fashion (Photo 4) [21].



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  		Photo 3 Representative coronal sections of technetium 99 methylene diphosphonate bone SPECT scans showing normal uptake in the sternum before the operation (A), and reduced uptake in the left hemisternum after the operation (B), with a pedicled ITA graft. (Reprinted from [21] with permission of Elsevier Inc.)

 


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  		Photo 4 Representative coronal sections of technetium 99 methylene diphosphonate bone SPECT scans showing normal uptake in the sternum before the operation (A), and normal uptake in the left hemisternum after the operation (B), with a skeletonized ITA graft. (Reprinted from [21] with permission of Elsevier Inc.)

 

   Surgical strategies
Top
 Summary
 Introduction
 Surgical strategies
Surgical technique
 Results
 References
 
The LIMA is generally considered to be the graft of choice for the LAD system. When both IMAs are used, the main problem is to identify the best target vessel for the RIMA. Many studies showed that the most important target for the RIMA is not the RCA system, but the lateral wall [12,13,22], being the patency of the RIMA grafted on the RCA system similar to the SVG one [23,24].

When the two IMAs are used, different configurations can be designed.

If both grafts have to remain in situ, then the RIMA can be used to the LAD and the LIMA to the lateral wall. Another possibility is to use the LIMA on the LAD and the RIMA to the lateral wall, passing over the aorta or behind it, through the transverse sinus. Finally, the LIMA can be used to the LAD and the RIMA to the RCA. This latter configuration is seldom used, as its long-term results are not constant [25]. Nevertheless, it can be used when the RCA is more important than the circumflex artery system and the proximal quality of the RCA is acceptable.

As there is a strong tendency to use both IMAs to the left coronary system, the RIMA can be used as a free graft and sutured to the LIMA, as a T or a Y [26,27]. Even if different studies have demonstrated that the flow reserve of a composite graft is such as to support the request of the myocardium nourished by the left main artery [28], we think that this strategy has to be used when the grafted territories have the same expected run-off, to avoid flow competition.

A particular composite conduit is the elongation graft, where another graft can be used to increase the length of the donor IMA (the elongating conduit can be the RIMA, the radial artery, the inferior epigastric artery or a saphenous vein). This configuration is often used when the aorta is untouchable or to solve some special unforeseeable problem. Midterm results were reported only by Vitolla et al., and are fully satisfying [29].

How to use the two IMAs (in situ, as a Y or T graft, pedicled or skeletonized) is still controversial, but data from the literature seem to show good results with all these strategies [11,26,27].


   Surgical technique
Top
 Summary
 Introduction
 Surgical strategies
 Surgical technique
Results
 References
 
The IMA is generally harvested as pedicle (Video 1), that includes the veins, the muscle around it and the fascia. The harvesting as a skeletonized conduit is becoming more and more popular (Video 2), as it increases the length of the conduit [16]. Another important side effect is the preservation of the sternal vascularization. The use of hemoclips (MMCTSLink 68) and scissors preserves the integrity of the collateral circulation directed toward the sternum. This was also demonstrated by Cohen et al. [21] using pre- and postoperative technetium 99 bone scan. The rationale of extensive use of BIMA in diabetic patients is based on these findings. The use of ultrasounds (MMCTSLink 69) to harvest the IMA as a skeletonized conduit is also becoming popular (Video 3).



Click on image to view video		 Video 1 Pedicled harvesting of the internal mammary artery.
 


Click on image to view video		 Video 2 Skeletonized harvesting of the internal mammary artery using the cautery (MMCTSLink 71).
 


Click on image to view video		 Video 3 Skeletonized harvesting of the internal mammary artery using the ultrasound scalpel (MMCTSLink 69).
 
When the IMA is harvested, it is closed distally. Different strategies are used to increase its size: external hot water, vasodilators or both. We prefer to inject inside the graft 5–8 ml of a solution containing 1 mg of papaverine for each ml (Video 4).



Click on image to view video		 Video 4 Injection of 8 ml of a solution containing 1 mg of papaverine each ml inside the graft.
 
When the RIMA is used in situ, it can be grafted to the RCA (Video 5), to the LAD (Video 6) or to the lateral wall, generally going through the transverse sinus (Video 7).



Click on image to view video		 Video 5 In situ right internal mammary artery is grafted to the right coronary artery.
 


Click on image to view video		 Video 6 In situ right internal mammary artery is grafted to the left descending artery.
 


Click on image to view video		 Video 7 In situ right internal mammary artery is grafted to the lateral wall, generally going through the transverse sinus.
 
When the RIMA is used as a free graft, it is generally sutured to the LIMA to obtain a composite conduit (Video 8). If the target of the RIMA is the lateral wall (the most diffuse strategy), the anastomosis between the conduits is roughly at the level of the pulmonary valve (Video 9). If the target is the RCA system (generally the posterior descending artery), the anastomosis between the conduits is more distal (Video 10).



Click on image to view video		 Video 8 Schematic view: free-graft internal mammary artery is sutured onto the other one to perform a Y-graft.
 


Click on image to view video		 Video 9 Intraoperative view: free-graft right internal mammary artery is anastomized onto the left one (Y-graft) at the level of the pulmonary valve.
 


Click on image to view video		 Video 10 Intraoperative view: free-graft right internal mammary artery is anastomized onto the distal portion of the left one (Y-graft) in order to revascularize the posterior descending artery.
 
If necessary, another conduit can be added end-to-end to the IMA to obtain an elongation conduit. The suture (MMCTSLink 50) can be directly end-to-end (Videos 11 and 12) or end-to-side, followed in this case by the occlusion of the proximal portion of the second graft (Schematic 5).



Click on image to view video		 Video 11 Schematic view: end-to-end anastomosis for lengthening of one graft with another one.
 


Click on image to view video		 Video 12 Intraoperative view: a saphenous vein graft is anastomosed end-to-end onto the left internal mammary artery.
 


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  		Schematic 5 Lengthening of internal mammary artery with another graft by means of an end-to-side anastomosis, followed by the occlusion of the proximal portion of the second graft.

 
The distal anastomoses can be end-to-side (Video 13); in case of sequential anastomoses, the configuration is side-to-side, parallel, as for the diagonals (Video 14), or diamond shaped, generally used for the intermediate anastomosis in the lateral wall (Video 15). The use of two slings (behind the inferior vena cava and through the transverse sinus) is helpful to obtain an adequate vision of the lateral and inferior walls (Video 16).



Click on image to view video		 Video 13 Schematic end-to-side distal anastomosis: the suture (MMCTSLink 50) is started with one of two needles from the left side of the IMA heel, very close to the corner, from the outside to the inside. It is then passed through the left side of the proximal corner of the coronary vessel, from the inside to the outside. This running suture continues up to anastomize the heel of the IMA onto the proximal corner of the coronary vessel (A); the suture is then continued starting from the left side of the IMA; the first stitch is reserved (U-bite) to allow a suture outside-inside in the IMA and inside-outside in the coronary vessel (B). After passing the apex of the IMA the suture is started with the other needle, from the right side with the same sense as before (C). Intraoperative view of an end-to-side distal anastomosis.
 


Click on image to view video		 Video 14 Schematic end-to-side distal anastomosis (IMA to diagonal branch): the suture is started from the distal corner of the IMA, from the outside to the inside. The needle is then passed through the distal corner of the coronary vessel, from the inside to the outside and the suture is continued along the right side of the IMA and along the left side of the coronary vessel up to the proximal corner of both (A). After passing the apex of the IMA the suture is started with the other needle, from the right side, with the same sense as before (B) up to end the anastomosis (C). Intraoperative view of a side-to-side distal anastomosis (LIMA to diagonal branch).
 


Click on image to view video		 Video 15 Schematic end-to-side distal anastomosis (diamond-shaped): The starting suture runs from the distal corner of the IMA (outside-to-inside) to the middle point of the left side of the coronary vessel (inside-to-outside). Five stitches are passed to reach the opposite part of either the IMA and the coronary (A); the vessels are then approached and 3 additional stitches are passed, starting with the other needle and changing the direction of the suture (U-stitches), which is always inside-outside in the coronary artery and outside-inside in the IMA (B); if the site of a diamond-shaped anastomosis lies deep into the epicardium, the flow to the distal part of the sequential graft is endangered by the seagull-wings kinking effect, especially when the myocardium will resume contractions (C). Intraoperative view of a side-to-side distal anastomosis (diamond-shaped).
 


Click on image to view video		 Video 16 The use of two slings (behind the inferior vena cava and through the transverse sinus) is helpful to obtain an adequate vision of the lateral and inferior walls.
 
Perioperative quality control of the distal anastomoses
The recent development of myocardial revascularization without cardiopulmonary bypass increased the interest in the possibility to detect the quality of the anastomosis in the operating theatre. There are essentially two methods: functional, based on ultrasounds, and morphologic, based on perioperative imaging (MMCTSLink 70).

Transit time Doppler flow evaluation
It is based on the principle that the waveform obtained when ultrasounds, generated by a source A and reflected by a surface B, are captured by a surface C, is directly related to phasic changes of volume of blood passing through a graft positioned in the middle of the system (Schematic 6). The shape of the curve obtained is shown in Schematic 7. The analysis includes the evaluation of the maximum peak flow, the minimum peak flow, the mean flow, the back flow and the pulsatility index (maximum peak flow – minimum peak flow/mean flow). Whereas there are no strictly normal values (the flow in the graft is depending on the length of the graft, the driving pressure, the resistances to the flow and to the size of the graft itself), an acceptable value for the pulsatility index has to be 3 or below.



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  		Schematic 6 Transit-time Doppler flow evaluation is based on the principle that the waveform obtained when ultrasounds, generated by a source A and reflected by a surface B, are captured by a surface C is directly related to phasic changes of volume of blood passing through a graft positioned in the middle of the system.

 


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  		Schematic 7 The shape of the curve obtained with transit-time Doppler flow (MMCTSLink 56).

 
The presence of a huge diastolic flow guarantees an unrestricted flow into the graft (Graph 1). In a composite Y graft the shapes of the curves are the mirror of the resistances of the different territories (Graph 2). In presence of low flow, a dobutamine stress test, injecting a bolus of 20 µg, can increase the diastolic flow if the distal anastomosis is not restrictive (Graph 3).



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  		Graph 1 The presence of a huge diastolic flow guarantees an unrestricted flow into the graft.

 


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  		Graph 2 (A) Flow before Y anastomosis in a composite Y graft. (B) Flow in the LAD targeted branch of the Y graft. (C) Flow in the OM targeted branch of the Y graft.

 


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  		Graph 3 (A) Low flow in basal condition. (B) Increase of diastolic flow after injection of dobutamine.

 
Perioperative imaging
This system (MMCTSLink 70) consists of a camera, that generates a laser light, positioned over the patient. The imaging agent (indocyanine green) is injected in the venous flow by the anesthesist. The laser stimulates the imaging agent causing the fluorescence which enables the camera to follow it as it flows through the graft. The images are transmitted to a monitor and then recorded.

The interest in this method is the possibility not only to visualize the flow inside the graft, but also to study the spontaneous distribution of the flow according to the different resistances as the dye is not injected manually with force inside the graft (as during conventional angiography). The quality of the images obtained is very high (Video 17). Many interesting findings can be observed, as competition of flow in the case of the Y graft (Videos 18 and 19) or sequential grafting (Video 20). When surgery is performed off-pump, it is possible to detect the patency of each distal anastomosis (Video 21).



Click on image to view video		 Video 17 Quality comparison of images acquired with traditional angiography and indocyanin intraoperative angiography.
 


Click on image to view video		 Video 18 Competition of flow in Y graft before and after injection of dobutamin.
 


Click on image to view video		 Video 19 (Continued from Video 18).
 


Click on image to view video		 Video 20 Competition of flow in sequential anastomosis before and after injection of dobutamin.
 


Click on image to view video		 Video 21 Patency control of anastomosis during off-pump bypass.
 
Postoperative controls
A coronary angiography is the golden standard to control the results of surgical myocardial revascularization (Video 22). Unfortunately it is nearly impossible to have routine angiographies. Alternative techniques, as multi slices angio CT scan, have been developed and, especially with the further improvements, can be very helpful in postoperative controls (Video 23).



Click on image to view video		 Video 22 Postoperative coronary angiography evaluating surgical result.
 


Click on image to view video		 Video 23 Postoperative multislices angio TC scan evaluating surgical result.
 

   Results
Top
 Summary
 Introduction
 Surgical strategies
 Surgical technique
 Results
References
 
LIMA vs. SVG

  • Left internal mammary artery provides higher cumulative survival (P<0.01), less early recurrence of angina (P<0.01), fewer myocardial infarctions (P<0.02), fewer reoperations (P<0.001), and better cumulative event-free survival (P<0.01) than saphenous vein graft, 15 years after the operation [5].
  • 10-year survival according to the number of diseased vessels was [4]:
    • 1-vessel disease: 93.4% (LIMA) vs. 88.0% (SVG) P=0.05
    • 2-vessel disease: 90.0% (LIMA) vs. 79.5% (SVG) P<0.0001
    • 3-vessel disease: 82.6% (LIMA) vs. 71.0% (SVG) P<0.0001

  • Cox multivariate analysis has confirmed that SVG is a risk factor for 10-year outcome: HR=1.61 (survival); HR=1.41 (late myocardial infarction); HR=1.25 cardiac events; HR=2.00 cardiac reoperation HR=1.27 all late cardiac events [4].
  • Angiographic results: within 5 years of operation, mammary artery graft patency exceeded vein graft patency. Between 5 and 12 years after operation, the attrition rate of vein grafts greatly exceeded that of mammary artery grafts (82% for SVG and 97% for IMA P<0.0001) [6].
  • Our experience: from September 1986 up to December 2001, 1014 patients (507 in each group) were selected by means of propensity score according to the graft (LIMA or SVG) used on the LAD. Two groups (LIMA and SVG), 507 patients each, were identified. Long-term clinical results were:
    • 15-year freedom from death of any cause: 82.6±2.6 (LIMA) vs. 66.3±2.3 (SVG), P<0.0001 (Graph 4)
    • 15-year freedom from cardiac death: 90.3±2.1 (LIMA) vs. 76.3±2.1 (SVG), P<0.0001 (Graph 5)
    • 15-year freedom from cardiac events: 78.9±3.0 (LIMA) vs. 69.5±2.3 (SVG), P=0.0207 (Graph 6)
    • 15-year freedom from any event: 66.2±4.1 (LIMA) vs. 52.4±2.6 (SVG), P=0.0122 (Graph 7).

  • Cox analysis confirmed that the use of saphenous veins is an independent variable for lower freedom from death of any cause (HR=2.0, P<0.001), freedom from cardiac death (HR=2.5, P<0.001), freedom from cardiac events (HR=1.4, P=0.017) and freedom from any event (HR=2.0, P<0.001).



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  		Graph 4 Fifteen-year freedom from death of any cause between patients who received left internal mammary artery (blue line) or saphenous vein graft (red line).
 


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  		Graph 5 Fifteen-year freedom from cardiac death between patients who received left internal mammary artery (blue line) or saphenous vein graft (red line).
 


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  		Graph 6 Fifteen-year freedom from cardiac events between patients who received left internal mammary artery (blue line) or saphenous vein graft (red line).
 


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  		Graph 7 Fifteen-year freedom from any event between patients who received left internal mammary artery ((blue line) or saphenous vein graft (red line).
 
BIMA vs. LIMA

  • Lytle et al. [11,30] reported better survival after 5, 10, 15 and 20 years if BIMA was used, independently from the anastomotic site of the RIMA.
  • Pick [13] showed that patients undergoing BIMA grafting presented higher freedom from cardiac death.
  • Berreklouw [14] also showed higher freedom from angina return, AMI and, globally, from ischemic events.
  • The Cleveland Clinic found less incidence of repeat revascularization [10].
  • Our experience: In a recent propensity analysis [15], early and late results of 576 patients younger than 75 years, who underwent first time myocardial revascularization using BIMA (±SVG) were compared with those of 576 patients who received LIMA and SVG:
    • Group BIMA showed better 10-year freedom from cardiac death (96.5±0.8 vs. 91.3±1.4, P=0.0288) and from cardiac events (93.9±1.1 vs. 86.3±1.8, P=0.0388), whereas no significant difference was found out regarding freedom from death of any cause (90.5±2.8 vs. 87.1±1.6, P=0.0696) and from any event (86.3±2.9 vs. 80.1±2.5, P=0.0973) (Graphs 8,9,10,11).

  • Cox analysis confirmed that LIMA+SV(s) was an independent risk factor for lower freedom from cardiac death (HR=1.9), AMI (2.3), AMI in the grafted area (HR=2.8) and cardiac events (HR=1.5).



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  		Graph 8 Ten-year freedom from death of any cause between patients who received BIMA±SVG (red line) or LIMA+SVG (blue line).
 


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  		Graph 9 Ten-year freedom from cardiac death between patients who received BIMA±SVG (red line) or LIMA+SVG (blue line).
 


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  		Graph 10 Ten-year freedom from cardiac events between patients who received BIMA±SVG (red line) or LIMA+SVG (blue line).
 


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  		Graph 11 Ten-year freedom from any event between patients who received BIMA±SVG (red line) or LIMA+SVG (Blue line).
 
Diabetic patients
Diabetes has represented for a long time the main limitation to use BIMA [31,32] because of a higher incidence of deep sternal infection. Recently, IMA harvesting as a skeletonized conduit [16] together with a better-controlled glucose management in the postoperative period [33], was shown to reduce the incidence of this complication. In a series of 400 diabetic patients [34] selected using propensity score analysis, BIMA was found to be a protective factor for long-term outcome if compared with LIMA and SVG. Moreover, no differences were found out between using BIMA or LIMA+SVG regarding sternal wound problems (3.0% BIMA vs. 1.5% LIMA, P=0.500).



   References
Top
 Summary
 Introduction
 Surgical strategies
 Surgical technique
 Results
 References
 

  1. Vineberg AM. Development of the anastomoses between the coronary vessel and a transplanted internal mammary artery. Can Med Assoc J 1946;55:117.
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