HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nasu, M. Articles by Shomura, T. Search for Related Content PubMed PubMed Citation Articles by Nasu, M. Articles by Shomura, T.

Ann Thorac Surg 1995;59:154-162
© 1995 The Society of Thoracic Surgeons

Postoperative Flow Characteristics of Left Internal Thoracic Artery Grafts

Departments of Thoracic and Cardiovascular Surgery and Cardiology, Kobe City General Hospital, Kobe, Japan

Accepted for publication July 21, 1994.

	Abstract

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Twenty patients whose left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) underwent postoperative coronary angiography and Doppler ultrasound velocimetry. During angiography, the diameter of the LITA conduit was measured at three points: proximal, mid, and distal. The degree of left anterior descending artery stenosis proximal to the anastomotic site was evaluated by densitometry. The LITA flow velocity pattern was obtained at the three points to calculate the total, systolic, and diastolic flow volume. There were significant differences in the total LITA flow among the three points (proximal, 36.0 ± 17.2 mL/min; mid, 29.9 ± 15.2 mL/min; distal, 27.2 ± 14.0 mL/min; p < 0.001 between the proximal and the mid or distal portions). The degree of left anterior descending artery stenosis affected the distal LITA flow and diameter (r = 0.823 and 0.811, respectively). There were significant differences in the systolic LITA flow among the three points (proximal, 13.2 ± 6.5 mL/min; mid, 8.1 ± 4.7 mL/min; distal, 5.6 ± 3.4 mL/min; p < 0.001 between the proximal and the mid or distal portions). However, there was no statistically significant difference in the diastolic LITA flow among the three points (proximal, 22.9 ± 11.0 mL/min; mid, 21.7 ± 10.8 mL/min; distal, 21.6 ± 10.8 mL/min). We conclude that a lower degree of LAD stenosis significantly reduces the LITA flow, inducing the string phenomenon. Additionally, during the diastolic phase, the LITA graft transports the blood primarily to the coronary artery but not to the side branches. Therefore, the steal phenomenon might not apply in the setting of an LITA graft.

	Introduction

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
See also page 161.

The many clinical capabilities of the left internal thoracic artery (LITA) as graft material have been established by many surgeons. However, some problems with its use still remain. Although the biggest advantage of an LITA graft is its long-term patency [1], flow reserve is limited during exercise despite the relief of angina [2]. The string phenomenon may occur when an LITA graft is anastomosed to the left anterior descending artery (LAD) with a low-grade proximal stenosis [3–6]. Additionally, the size of the LITA graft depends on LITA flow [2]. However, these observations are mainly based on angiographic findings and there are no clinical reports concerning the relationship of the size of the LITA graft or the degree of LAD stenosis with the actual flow of the LITA graft. The steal phenomenon was observed in patients who received an LITA graft that included a large remnant of the lateral costal branch [7–11]. When the steal phenomenon is generally discussed, the areas involved are in either the systemic or coronary circulation. On the contrary, an LITA graft perfuses both the systemic and coronary circulations. However, there is a big difference in the perfusion pattern between the coronary and systemic circulations. Although the systemic circulation is mainly perfused during the systolic phase, the coronary circulation is primarily perfused during the diastolic phase. Therefore, it seems that the same mechanism cannot account for the steal phenomenon affecting an LITA graft.

The present study focused on the following two issues: (1) whether proximal LAD stenosis affects on the LITA graft flow volume, and (2) whether side branch flow compromises coronary perfusion from an LITA graft.

	Material and Methods

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Patients
Twenty patients (19 male, 1 female) underwent coronary angiography and the Doppler ultrasound velocimetry after they had undergone coronary artery bypass grafting using an LITA graft. Their age at examination ranged from 35 to 72 years (mean, 53.2 ± 11.1 years). Other patient characteristics are given in Table 1. The follow-up examination was performed from 1 to 56 months after the grafting procedure (average, 7.4 ± 13.3 months). In 14 patients, angiography was performed before discharge within 1 month postoperatively to confirm the success of the operative results. The remaining 6 patients were evaluated because they had shown an abnormal response during stress testing 10 to 56 months after the operation. Left ventriculography revealed normal motion of the anterior wall in 11 patients, hypokinesis in 5, and akinesis in 4. Coronary angiography showed no notable stenosis at the LITA anastomotic site and various degrees of stenosis in the LAD proximal to the anastomotic site. In 5 patients, 50% to 75% stenosis was observed; in 4, 76% to 90% stenosis; in 5, 91% to 99% stenosis; and, in 6, 100% stenosis. In addition, those patients in whom LITA angiography revealed the presence of the string phenomenon were not included in this study because the Doppler guidewire interfered with LITA flow in such patients, which made accurate assessment of flow impossible.

Flow Velocity Measurements in the LITA Graft
Details on the instrumentation used have been given in previous articles [12, 13]. All flow velocity measurements were performed with a 0.018-inch, 12-MHz, Doppler flow guidewire (Cardiometrics). The transducer has an estimated sample volume size of 2.5 mm and a diameter at range rate depth of 5 mm. The pulsed-Doppler ultrasound velocimeter (Flowmap; Cardiometrics) consisted of a real-time spectral analysis system. The Doppler system can compute a variety of on-line spectral variables.

After angiographic study of the LITA graft, a 5F catheter was positioned in the origin of the LITA from the left subclavian artery. The Doppler guidewire was advanced through the catheter and into the LITA graft and introduced to the anastomotic site. Thereafter, the guiding catheter was drawn out from the origin of the subclavian artery to avoid disturbing LITA flow. Flow velocity in the LITA graft was measured at the same three points where the diameter of the LITA graft was measured. The Doppler system can compute a variety of online spectral variables, including the time-averaged spectral peak velocity and the systolic and diastolic time velocity integral. No patients suffered any complications related to the conduit cannulation or the Doppler guidewire instrumentation.

Quantification of Flow Volume in the Left Internal Thoracic Artery
A quantitative estimate of LITA flow volume was calculated from Doppler velocity data using the following equation:

(1)

where Q is the flow volume, D is the LITA diameter, and APV is the time-averaged peak velocity [12].

In addition, systolic and diastolic LITA flows were calculated using the following equations:

(2)

and

(3)

where Qs is the systolic LITA flow, Q is the total LITA flow, SI is the systolic time velocity integral, DI is the diastolic time velocity integral, and Qd is the diastolic LITA flow. The total, systolic, and diastolic LITA flows were estimated at the three points.

Statistical Analysis
Simple regression analysis was used to evaluate the LITA diameter and the total LITA flow in relation to the severity of the proximal LAD stenosis. One-way analysis of variance was used to estimate the total, systolic, and diastolic LITA flow in relation to the sampling position; and repeated measures analysis of variance was used to compare the values at the three points. Between-group differences were compared by Scheffé's test, and a p value of less than 0.05 was considered statistically significant. All data were expressed as the mean ± standard deviation.

	Results

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Flow Velocity Patterns in the Left Internal Thoracic Artery Graft
In a patient whose LAD was totally occluded, typical biphasic velocity waveforms were consistently obtained along the length of the LITA conduit, and the predominance of the diastolic component over the systolic one at the distal LITA segment was significantly greater than that at the proximal segment (Fig 1). In a patient with less LAD stenosis, a similar transformation was observed from the proximal segment to the mid segment of the LITA conduit (Fig 2). However, the systolic retrograde flow from the LAD to the LITA graft was noted at the distal part of the graft. This finding of retrograde flow corresponded to the back flow observed when a radiopaque substance was injected into the LAD during angiography.

View larger version (88K): [in this window] [in a new window]   Fig 1. . Flow velocity patterns in a left internal thoracic artery graft at each position in a patient with 100% stenosis of the left anterior descending artery. Flow velocity patterns are consistently biphasic along the length of the graft. The predominance of the diastolic component over the systolic one is greater at the distal segment than at the proximal one.

View larger version (96K): [in this window] [in a new window]   Fig 2. . Flow velocity patterns in a left internal thoracic artery graft at each position in a patient with 50% stenosis of the left anterior descending artery. Biphasic waveforms are seen at the proximal and mid segments of the left internal thoracic artery graft. At the distal segment, systolic reverse flow is observed.

View larger version (19K): [in this window] [in a new window]   Fig 3. . (A) Diameter of left internal thoracic artery (LITA) graft at each position. There is a significant difference in the diameter among the three points (p < 0.001 between the proximal and mid segments, between the proximal and distal segments, and between the mid and distal segments). (B) Flow volume of the left internal thoracic artery graft at each position. There is a significant difference among the three points (p < 0.001 between the proximal and distal segments, and p < 0.01 between the proximal and mid segments). (dis = distal; n.s. = not significant; px = proximal.)

View larger version (22K): [in this window] [in a new window]   Fig 4. . (A) Correlation of the degree of stenosis of the left anterior descending artery (LAD % stenosis) with the distal diameter of the left internal thoracic artery (LITA). The degree of stenosis significantly affected the distal diameter of the left internal thoracic artery graft (r = 0.811). (B) Correlation of the degree of stenosis of the left anterior descending artery with the distal flow volume of the left internal thoracic artery graft. The degree of stenosis significantly affected the flow in the graft (r = 0.823).

View larger version (19K): [in this window] [in a new window]   Fig 5. . (A) The diastolic flow volume at the three points in the left internal thoracic artery (LITA) graft. There was no statistical significance among the three points. Therefore, the diastolic blood flow in the graft is primarily perfusing the coronary system. (B) The systolic flow volume at the three points in the left internal thoracic artery graft. There was a significant difference between the flow in the proximal and mid segments (p < 0.001), between the proximal and distal segments (p < 0.001), and between the mid and distal segments (p < 0.01). (dis = distal; n.s. = not significant; px = proximal.)

	Comment

Top Footnotes Abstract Introduction Material and Methods Results Comment References

It was reported that the string sign occurred when an LITA graft was anastomosed to an LAD with low-grade proximal stenosis [3–6]. Kitamura and colleagues [17] showed angiographically that an LITA graft is patent even when the string sign with no flow occurs, so-called no-flow patency. Seki and associates [3] contended that the string phenomenon could be regarded as a physiologic change reflecting the LITA graft's response to the blood flow demands. All of these views were based on angiographic findings.

In our study, we calculated the LITA flow from the LITA size, determined during angiography, and the LITA flow velocity profile, obtained using the Doppler guidewire, to evaluate quantitatively the relationship of the proximal LAD stenosis to LITA flow. Our data showed that the LITA flow volume decreased proportionate to the decrease in the grade of the LAD stenosis. In the patients with a less than 70% LAD stenosis, the LITA flow was less than 20 mL/min and the systolic reverse flow was detected. Theoretically, LITA flow should be zero in patients with a less than 40% LAD stenosis. In the patients with a completely obstructed LAD, the LITA flow rates were distributed widely because the perfusion areas and myocardial function status in our patients varied. If we could study a population of patients who had not suffered myocardial infarction and had only a single LAD obstruction or stenosis at a similar segment, we would be able to obtain a more linear correlation between the extent of proximal LAD stenosis and LITA flow volume. However, it would be impossible to collect such a group of patients. Nevertheless, the p value is sufficiently high in our patients to indicate a linear correlation between the proximal LAD stenosis and the LITA flow volume.

Recently, in a long-term experimental study conducted by Lust and colleagues [18], it was found that, even after 2 months of chronic flow competition from a fully patent native artery, there was still a recruitable flow reserve for the LITA graft when the native vessels were occluded. In a patient of Kitamura and associates [17], the anatomic patency of a nonfunctioning LITA graft was demonstrated when the native artery was occluded by a percutaneous transluminal coronary angioplasty balloon catheter. We encountered an interesting case that also shed light on this matter (Figs 6, 7). One month after operation in a patient of ours, LITA arteriography revealed the presence of the string phenomenon together with backflow of the radiopaque substance into the LAD. One year after operation, the LITA conduit was observed to be functioning despite a totally occluded proximal LAD, and the flow velocity pattern of the LITA graft was normally biphasic. These findings indicate that a string sign represents a dynamic response to a sustained period of flow competition. However, basic research has shown that a direct product of the velocity of flowing blood, shear stress, is implicated as a cause of the vascular remodeling that occurs in native vessels [19]. Therefore, it remains open to question how long the anatomic patency and flow recruitability can be maintained in a nonfunctioning LITA graft.

View larger version (149K): [in this window] [in a new window]   Fig 6. . (A) Angiogram of the left anterior descending artery showing the string phenomenon 1 month after operation. At this time, an angiogram of the left anterior descending artery revealed good flow with backflow into the graft. (B) A functioning left internal thoracic artery graft was observed 1 year after operation, with total occlusion of the proximal left anterior descending artery.

View larger version (77K): [in this window] [in a new window]   Fig 7. . (A) Flow velocity pattern of a nonfunctioning left internal thoracic artery (LITA) graft 1 month after operation. The waveform of the nonfunctioning graft is similar to that of the systemic artery. (B) Flow velocity pattern of a functioning left internal thoracic artery graft 1 year after operation. The waveform is biphasic and the diastolic component is highly predominant over the systolic one.

Our study has three limitations. First, the changes in the LITA diameter during a cardiac cycle are ignored. At the present time, there is no way to obtain a real-time measurement of LITA diameters at the three points during a cardiac cycle. Angiography did not reveal any changes in the LITA size. The second drawback to our study was that the LITA flow velocity was only measured in the resting state. To investigate the steal phenomenon, we must perform the studies not only at rest but also during exercise.

The third limitation is that the flow calculation does not yield entirely accurate measurements. In addition, the patients in our study did not have large branches, but it is unlikely that the diastolic coronary vascular resistance is greater than the diastolic systemic one under any circumstances. Therefore, we believe that the flow pattern in the LITA graft does not change in any situation. Flemma and colleagues [21] observed LITA flow to range from 10 to 65 mL/min and average 43 mL/min intraoperatively, whereas Barner [22] observed it to average 56 mL/min. Both investigators used an electromagnetic flow probe. In our study, the distal LITA flow averaged 34 mL/min in 12 patients with a proximal LAD stenosis that exceeded 90%. Therefore, the calculated LITA flows in our patients are slightly lower than previously reported values. Doucette and associates [13] validated the accuracy of the flow measurement achieved using the Doppler guide wire method and quantitative angiography, both under in vivo and in vitro conditions. Their in vitro study showed that Doppler-derived flow, calculated using known tube diameters and estimating the mean velocity as 0.5 times the time-averaged peak velocity, was nearly identical to the flow measured by the electromagnetic flowmeter. It also showed that the tortuosity of the tube consistently caused the flow rate to be underestimated. Therefore, we positioned the guidewire tip at the straightly coursing segments of the LITA grafts. In addition, their in vivo study revealed that the Doppler-derived native coronary artery flow rate was comparable to the value determined by electromagnetic flowmeter approximately 85% of the time. This difference is attributed to the fact that the spatial flow pattern in a straightly coursing artery should be parabolic. Therefore, our LITA flow rates could be slightly lower than the real LITA flow rates.

Few articles about the LITA flow velocity pattern have been published. Bach's group [23] found a consistent biphasic flow velocity pattern along the length of LITA conduits and a gradual transition in the velocity pattern from a systemic to coronary artery flow velocity pattern. They attributed this finding to a particular intrinsic property of the internal mammary artery wall, possibly its high elastic tissue content. Certainly, van Son and associates [24] showed the tissue that makes up the proximal and distal segments is elastomuscular and that of the mid segment is elastic. In Guo-Wei's pharmacologic study [25], the reactivity of the distal LITA section was found to be inversely correlated with the diameter of the artery. The findings from these studies suggest that the vascular compliance of the LITA varies along its length. This variability might account for the gradual transition in the LITA flow velocity pattern. However, as any surgeon knows, postoperatively the LITA is tightly surrounded by hard connective tissue, and this might cause a highly compliant vessel to be less compliant. Bach and colleagues [23] missed the LITA flow diversion to side branches and the coronary artery. We believe that LITA flow diversion is a primary cause of the gradual transition in the flow velocity pattern along the length of the LITA conduit.

In summary, the presence of an LAD stenosis proximal to the anastomotic site significantly affects the LITA flow volume, and this validates the observations made previously on the basis of angiographic findings. Additionally, an LITA graft transports the blood primarily to the coronary artery during the diastolic phase and the steal phenomenon might not apply in the setting of an LITA graft.

	Footnotes

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Address reprint requests to Dr Nasu, Department of Thoracic and Cardiovascular Surgery, Kobe City General Hospital, 4-6, Minatojima-Nakamachi, Chuo-ku, Kobe, Hyogo, 650, Japan.

	References

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 

1. Boylan MJ, Lytle BM, Loop FD, et al. Surgical treatment of isolated left anterior descending coronary stenosis. Comparison of left internal mammary artery and venous autograft at 18 to 20 years of follow-up. J Thorac Cardiovasc Surg 1994;107:657–62.[Abstract/Free Full Text]
2. Kawasuji M, Tedoriya T, Takemuro H, Sakakibara N, Taki J, Watanabe Y. Flow capacities of arterial grafts for coronary artery bypass grafting. Ann Thorac Surg 1993;56:957–62.[Abstract]
3. Seki T, Kitamura S, Kawachi K, et al. A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery. J Thorac Cardiovasc Surg 1992;104:1532–8.[Abstract]
4. Ivert T, Huttunen K, Landou C, Bjork VO. Angiographic studies of internal mammary artery grafts 11 years after coronary artery bypass grafting. J Thorac Cardiovasc Surg 1988;96:1–12.[Abstract]
5. Dincer B, Barner HD. The ``occluded'' internal mammary artery graft: restoration of patency after apparent occlusion associated with progression of coronary disease. J Thorac Cardiovasc Surg 1983;85:318–20.[Medline]
6. Arice A, Borras X, Ramino J. Patency of internal mammary grafts in no-flow situations. J Thorac Cardiovasc Surg 1987;93:62–4.[Abstract]
7. Schmid C, Heublein B, Reichelt S, Borst HG. Steal phenomenon caused by a parallel branch of the internal mammary artery. Ann Thorac Surg 1990;50:463–4.[Abstract]
8. Wolfenden HD, Newman DC. Avoidance of steal phenomena by thorough internal mammary artery dissection. J Thorac Cardiovasc Surg 1992;103:1230–1.[Medline]
9. Pelias A, Del Rossi A. A case of postoperative internal mammary steal. J Thorac Cardiovasc Surg 1985;90:794–5.
10. Singh RN, Magovern GJ. Internal mammary graft: improved flow resulting from correction of steal phenomenon. J Thorac Cardiovasc Surg 1982;84:146–9.[Medline]
11. Singh RN, Pittsburgh P, Sosa JA. Internal mammary artery--coronary artery anastomosis. Influence of the side branches on surgical result. J Thorac Cardiovasc Surg 1981;82:909–14.[Abstract]
12. Segal J, Kern MJ, Scott NA, et al. Alterations of phasic coronary artery flow velocity in humans during percutaneous coronary angioplasty. J Am Coll Cardiol 1992;20:276–86.[Abstract]
13. Docerre JW, Corl PD, Payne HM, et al. Validation of a Doppler guide wire for intravascular measurement of coronary artery flow velocity. Circulation 1992;85:1899–1911.[Abstract/Free Full Text]
14. Daly RC, McCarthy PM, Orzulak TA, Schaff HV, Edwards WD. Histologic comparison of experimental coronary artery bypass grafts. Similarity of in situ and free internal mammary artery grafts. J Thorac Cardiovasc Surg 1988;96:19–29.[Abstract]
15. Grondin CM, Campeau L, Lesperance J, Enjalbert M, Bourassa MG. Comparison of late changes in internal mammary artery and saphenous vein grafts in two consecutive series of patients 10 years after operation. Circulation 1984;70(Suppl 1):208–12.
16. Acinapura AJ, Rose DM, Jacobowitz IJ, et al. Internal mammary artery bypass grafting: influence on recurrent angina and survival in 2100 patients. Ann Thorac Surg 1989;48: 186–91.[Abstract]
17. Kitamura S, Kawachi K, Seki T, Sawabata N, Morita R, Kawata T. Angiographic demonstration of no-flow anatomical patency of internal thoracic--coronary artery bypass grafts. Ann Thorac Surg 1992;53:156–9.[Abstract]
18. Lust RM, Zeri RS, Spence PA, et al. Effects of chronic native flow competition on internal thoracic artery grafts. Ann Thorac Surg 1994;57:45–50.[Abstract]
19. Glagov S, Zarins C, Giddens DP, Ku DN. Hemodynamics and atherosclerosis. Insight and perspectives gained from studies of human arteries. Arch Pathol Lab Med 1988;112:1018–31.[Medline]
20. O'Brien JW, Johnson SH, VanSteyn SJ, et al. Effects of internal mammary artery dissection on phrenic nerve perfusion and function. Ann Thorac Surg 1991;52:182–8.[Abstract]
21. Flemma RJ, Singh HM, Tector AJ, Lepley D Jr, Frazier BL. Comparative hemodynamic properties of vein and mammary artery in coronary bypass operations. Ann Thorac Surg 1975;20:619–27.[Abstract]
22. Barner HB. Blood flow in the internal mammary artery. Am Heart J 1973;86:570–1.[Medline]
23. Bach RG, Kern MJ, Donohue TJ, Aguirre FV, Caracciolo EA. Comparison of phasic blood flow velocity characteristics of arterial and venous coronary artery bypass conduits. Circulation 1993;88(Suppl 2):133–40.
24. Van Son JAM, Smedts F, de Wilde PCM, et al. Histological study of the internal mammary artery with emphasis on its suitability as a coronary artery bypass graft. Ann Thorac Surg 1993;55:106–13.[Abstract]
25. He GW. Contractility of the human internal mammary artery at the distal section increases toward the end. Emphasis on not using the end of the internal mammary artery for grafting. J Thorac Cardiovasc Surg 1993;106:406–11.[Abstract]

This article has been cited by other articles:

				M. Taniguchi, T. Akasaka, Y. Saito, S. Kaji, T. Kawamoto, R. Sukmawan, H. Yoshitani, Y. Neishi, T. Ohe, K. Tanemoto, et al. Improvement of flow capacity of the left internal thoracic artery graft assessed by using a pressure wire. J. Thorac. Cardiovasc. Surg., October 1, 2007; 134(4): 1012 - 1016. [Abstract] [Full Text] [PDF]

				J. Hartman, H. Kelder, R. Ackerstaff, H. van Swieten, F. Vermeulen, and A. Bogers Preserved hyperaemic response in (distal) string sign left internal mammary artery grafts Eur. J. Cardiothorac. Surg., February 1, 2007; 31(2): 283 - 289. [Abstract] [Full Text] [PDF]

				C. M. Jones, T. Athanasiou, P. P. Tekkis, V. Malinovski, S. Purkayastha, A. Haq, J. Kokotsakis, and A. Darzi Does Doppler echography have a diagnostic role in patency assessment of internal thoracic artery grafts? Eur. J. Cardiothorac. Surg., November 1, 2005; 28(5): 692 - 700. [Abstract] [Full Text] [PDF]

				T. Shimizu, H. Suesada, M. Cho, S. Ito, K. Ikeda, and S. Ishimaru Flow Capacity of Gastroepiploic Artery Versus Vein Grafts for Intermediate Coronary Artery Stenosis Ann. Thorac. Surg., July 1, 2005; 80(1): 124 - 130. [Abstract] [Full Text] [PDF]

				J. F. Sabik III, B. W. Lytle, E. H. Blackstone, P. L. Houghtaling, and D. M. Cosgrove Comparison of Saphenous Vein and Internal Thoracic Artery Graft Patency by Coronary System Ann. Thorac. Surg., February 1, 2005; 79(2): 544 - 551. [Abstract] [Full Text] [PDF]

				A. Berger, P. A. MacCarthy, U. Siebert, S. Carlier, W. Wijns, G. Heyndrickx, J. Bartunek, H. Vanermen, and B. De Bruyne Long-Term Patency of Internal Mammary Artery Bypass Grafts: Relationship With Preoperative Severity of the Native Coronary Artery Stenosis Circulation, September 14, 2004; 110(11_suppl_1): II-36 - II-40. [Abstract] [Full Text] [PDF]

				J. F. Sabik III, B. W. Lytle, E. H. Blackstone, M. Khan, P. L. Houghtaling, and D. M. Cosgrove Does competitive flow reduce internal thoracic artery graft patency? Ann. Thorac. Surg., November 1, 2003; 76(5): 1490 - 1497. [Abstract] [Full Text] [PDF]

				M. Yoshitatsu, Y. Miyamoto, M. Mitsuno, K. Toda, M. Yoshikawa, S. Fukui, F. Nomura, N. Hirata, and K. Onishi Changes in left anterior descending coronary artery flow profiles after coronary artery bypass grafting examined by means of transthoracic Doppler echocardiography J. Thorac. Cardiovasc. Surg., November 1, 2003; 126(5): 1531 - 1536. [Abstract] [Full Text] [PDF]

				G. Polvani, M. R. Marino, M. Roberto, L. Dainese, A. Parolari, G. Pompilio, S. D. Matteo, A. Fumero, A. Cannata, F. Barili, et al. Acute effects of 17{beta}-estradiol on left internal mammary graft after coronary artery bypass grafting Ann. Thorac. Surg., September 1, 2002; 74(3): 695 - 699. [Abstract] [Full Text] [PDF]

				M. Gaudino, F. Alessandrini, G. Nasso, P. Bruno, A. Manzoli, and G. Possati Severity of coronary artery stenosis at preoperative angiography and midterm mammary graft status Ann. Thorac. Surg., July 1, 2002; 74(1): 119 - 121. [Abstract] [Full Text] [PDF]

				Y. Ichikawa, H. Kajiwara, Y. Noishiki, I. Yamazaki, K. Yamamoto, T. Kosuge, S. Sato, and Y. Takanashi Flow dynamics in internal thoracic artery grafts 10 years after coronary artery bypass grafting Ann. Thorac. Surg., January 1, 2002; 73(1): 131 - 137. [Abstract] [Full Text] [PDF]

				B. F. Buxton, P. Ruengsakulrach, J. Fuller, A. Rosalion, C. M. Reid, and J. Tatoulis The right internal thoracic artery graft - benefits of grafting the left coronary system and native vessels with a high grade stenosis Eur. J. Cardiothorac. Surg., September 1, 2000; 18(3): 255 - 261. [Abstract] [Full Text] [PDF]

				T. Shimizu, T. Hirayama, H. Suesada, K. Ikeda, S. Ito, and S. Ishimaru Effect of flow competition on internal thoracic artery graft: Postoperative velocimetric and angiographic study J. Thorac. Cardiovasc. Surg., September 1, 2000; 120(3): 459 - 465. [Abstract] [Full Text] [PDF]

				R. De Paulis, F. Tomai, A. Gaspardone, L. Colagrande, P. Nardi, A. Ghini, F. Versaci, A. P. de Peppo, P. A. Gioffre, and L. Chiariello CORONARY FLOW RESERVE EARLY AND LATE AFTER MINIMALLY INVASIVE CORONARY ARTERY BYPASS GRAFTING IN PATIENTS WITH TOTALLY OCCLUDED LEFT ANTERIOR DESCENDING CORONARY ARTERY J. Thorac. Cardiovasc. Surg., October 1, 1999; 118(4): 604 - 609. [Abstract] [Full Text] [PDF]

				P. Brenner, B. Wintersperger, A. von Smekal, V. Agirov, D. Bohm, E. Kreuzer, M. Reiser, and B. Reichart Detection of coronary artery bypass graft patency by contrast enhanced magnetic resonance angiography Eur. J. Cardiothorac. Surg., April 1, 1999; 15(4): 389 - 393. [Abstract] [Full Text] [PDF]

				Y. Yoshida, M. Fujita, Y. Kihara, S. Kubo, T. Tanaka, T. Iwase, S.-i. Tamaki, T. Sato, C.-H. Park, and A. Yamazato Assessment of long-term left internal thoracic artery graft patency by exercise Doppler echocardiography J. Thorac. Cardiovasc. Surg., April 1, 1998; 115(4): 954 - 956. [Full Text] [PDF]

				R. Malhotra, Y. Mishra, P. Maheshwari, Y. Mehta, and N. Trehan Minimally Invasive Coronary Artery Bypass as a Salvage Procedure Asian Cardiovasc Thorac Ann, March 1, 1998; 6(1): 62 - 63. [Abstract] [Full Text] [PDF]

				O. Tasdemir, U. Kiziltepe, H. Y. Karagoz, B. Yamak, S. Korkmaz, and K. Bayazit LONG-TERM RESULTS OF RECONSTRUCTIONS OF THE LEFT ANTERIOR DESCENDING CORONARY ARTERY IN DIFFUSE ATHEROSCLEROTIC LESIONS J. Thorac. Cardiovasc. Surg., September 1, 1996; 112(3): 745 - 754. [Abstract] [Full Text]

				M. Kawasuji, N. Sakakibara, H. Takemura, T. Tedoriya, T. Ushijima, and Y. Watanabe IS INTERNAL THORACIC ARTERY GRAFTING SUITABLE FOR A MODERATELY STENOTIC CORONARY ARTERY? J. Thorac. Cardiovasc. Surg., August 1, 1996; 112(2): 253 - 259. [Abstract] [Full Text]

				R. Cartier, O. S. Dias, M. Pellerin, Y. Hebert, and Y. Leclerc CHANGING FLOW PATTERN OF THE INTERNAL THORACIC ARTERY UNDERGOING CORONARY BYPASS GRAFTING: CONTINUOUS-WAVE DOPPLER ASSESSMENT J. Thorac. Cardiovasc. Surg., July 1, 1996; 112(1): 52 - 58. [Abstract] [Full Text]

				M. Nasu, T. Akasaka, H. Chikusa, and T. Shoumura Flow Reserve Capacity of Left Internal Thoracic Artery 23 Years After Vineberg Procedure Ann. Thorac. Surg., April 1, 1996; 61(4): 1242 - 1244. [Abstract] [Full Text]

				H. Takemura, M. Kawasuji, N. Sakakibara, T. Tedoriya, T. Ushijima, and Y. Watanabe Internal Thoracic Artery Graft Function During Exercise Assessed by Transthoracic Doppler Echography Ann. Thorac. Surg., March 1, 1996; 61(3): 914 - 919. [Abstract] [Full Text]

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nasu, M. Articles by Shomura, T. Search for Related Content PubMed PubMed Citation Articles by Nasu, M. Articles by Shomura, T.