Congenital Absence of Pericardium: A Case Report and Technical Considerations in Cardiac Surgery.

This case report describes a rare instance of left-sided congenital pericardial agenesis (CPA) encountered during coronary artery bypass grafting (CABG) in a 77-year-old male. In this unique case, the presence of an unusual strip of left pericardium containing the phrenic nerve posed significant surgical challenges. Special attention was required for the graft lay, ensuring adequate filling of the heart during assessment before closure, as well as emphasis on the need for generous graft length. Additionally, the evaluation of graft positioning prior to cardiopulmonary bypass was crucial. Despite these complexities, CABG was successfully performed with no complications to note. This case underscores the importance of adaptability in surgical technique to manage the unique challenges posed by CPA, leading to a positive outcome despite the atypical cardiac anatomy.

Bilateral versus Single Internal Thoracic Artery Grafting Strategies Supplemented by Radial Artery Grafting.

PURPOSE: It is unclear if a second or third arterial graft can improve clinical outcomes in coronary artery bypass graft surgery. We compared the outcomes of bilateral internal thoracic artery (BITA) plus radial artery (RA) grafting versus left internal thoracic artery (LITA) plus RA grafting after off-pump coronary artery bypass grafting. MATERIALS AND METHODS: Between January 2009 and December 2020, a total of 3007 patients with three-vessel coronary artery disease who underwent off-pump coronary artery bypass were analyzed. Among them, 971 patients received total arterial grafting using LITA. We divided the patients into two groups [group A, BITA+RA grafting (n=227) and group B, LITA+RA grafting (n=744)], and compared the survival and major adverse cardiac and cerebrovascular event (MACCE) rates between the two groups at 10 years. RESULTS: After risk adjustment with inverse probability treatment weighting methods, the freedom from all-cause mortality was 93.1% and 88.3% in groups A and B, respectively (p=0.140). The freedom from MACCE rates were 68.3% and 89.0%, respectively (p<0.0001). LITA plus RA grafting [hazard ratio (HR): 1.3, 95% confidence interval (CI): 1.05-2.37, p=0.025] and incomplete revascularization (HR 1.2, 95% CI: 0.70-2.15, p=0.046) were significant risk factors for MACCEs in multivariable Cox regression analysis. CONCLUSION: The rates of MACCEs were lower with LITA plus RA grafting than with BITA plus RA grafting in total arterial revascularization. Furthermore, complete revascularization improved long-term outcomes following total arterial grafting.

Long-term survival of single versus bilateral internal mammary artery grafting in patients under 70.

OBJECTIVES: As definitive data from randomized controlled trials comparing the effect on long-term survival of using single internal mammary artery (SIMA) or bilateral internal mammary artery (BIMA) grafting are not yet available, observational studies allow for long-term follow-up in large and representative populations, which might complement the information potentially derived from randomized trials. To compare long-term survival in patients under 70 years of age undergoing SIMA or BIMA grafting. METHODS: Retrospective analysis of 3384 consecutive patients under 70 years undergoing primary isolated coronary artery bypass grafting, performed from 2000 to 2015, in a Portuguese level III Hospital. We identified 2176 and 1208 patients from the study population who underwent SIMA and BIMA grafting, respectively. The primary end point was all-cause mortality at 10 years. We employed inverse probability weighting to restrict confounding by indication. RESULTS: The mean age of the study population was 59.4 (± 7.6) years, and 567 (16.8%) were females. Inverse probability weighting was effective in eliminating differences in all significant baseline characteristics. Follow-up was 99.88% complete. The median follow-up time was 12.82 (interquartile range, 9.65, 16.74) years: the primary end point of all-cause mortality at 10 years occurred in 463 patients (21.3%) and 166 (13.7%) in the SIMA and BIMA grafting groups, respectively (hazard ratio, 0.78; 95% confidence interval, 0.66-0.92; P = 0.004). CONCLUSIONS: Bilateral internal mammary grafting is associated with lower long-term mortality than single internal mammary grafting. Moreover, this survival benefit comes at no increased perioperative morbidity or mortality cost.

Left or bilateral internal mammary artery employment in coronary artery bypass grafting: midterm results.

BACKGROUND: The gold standard for coronary artery bypass grafting to the left anterior descending artery is use of the left internal mammary artery. Better long-term survival has been reported using bilateral internal mammary arteries compared to left internal mammary artery only, but many surgeons are reluctant to employ bilateral internal mammary arteries in coronary artery bypass grafting. This study aimed to evaluate the effectiveness and safety of bilateral internal mammary artery use. METHODS: From 2014 to 2017, 1703 patients underwent coronary artery bypass grafting in our institute. Of these, 772 met the inclusion criteria and were randomly assigned to receive bilateral (n = 387) or left (n = 385) internal mammary artery grafts. The mean age was 67.1 ± 6.0 years (range 48-85 years) and 474 (61.4%) were male. The mean number of diseased vessels was 3.1 ± 0.9, and mean EuroSCORE II was 3.4% ± 1.1%. RESULTS: Hospital mortality was 1.2% in the left internal mammary artery group vs. 1.8% in the bilateral internal mammary artery group (p = 0.55). There was no difference in procedure-related complications between groups. Mean follow-up was 65.9 months. Survival in the bilateral internal mammary artery group at 1, 3, and 5 years was 98.7%, 98.7%, and 94.8% vs. 98.1%, 98.1%, and 90.9%, respectively, in the left internal mammary artery group (p = 0.63). CONCLUSION: Application of bilateral internal mammary arteries in coronary artery bypass grafting is safe and effective, with comparable midterm results to those with the left internal mammary artery only.

Branched internal mammary conduit permits non-sequenced total arterial revascularization.

Recent trends in cardiac surgery have encouraged total arterial coronary revascularization, citing advantages in long-term patency and overall mortality. Often relying on sequenced, composite, and free-graft strategies, total arterial coronary revascularization is limited by conduit availability and surgical complexity. We present the use of bilateral internal mammary artery grafts to achieve nonsequential 3-vessel total arterial coronary revascularization using the preserved distal bifurcation of the right internal mammary artery. Utilization of distal internal mammary artery branches should be considered a viable strategy in select patients and can broaden the opportunities for total arterial coronary revascularization in patients with multivessel coronary disease.

Coronary-coronary bypass grafting: artery or vein?

BACKGROUND: The method of coronary-coronary bypass grafting was described in 1987 but has not been widely used, and there are only a few studies that report good short-term and mid-term results as well as some individual cases of long-term follow-up. In our medical institution, we carried out an analysis of the long-term results of coronary-coronary bypass grafting, which are presented in this study. METHODS: This was a retrospective single-center study on 95 patients who underwent coronary-coronary bypass grafting as a supplement to the standard coronary bypass grafting procedure. All patients underwent angiographic assessment of the coronary bypass grafts during the long-term follow-up period. The observation period was up to 123 months. Angiographic assessment of 109 coronary-coronary grafts was carried out. RESULTS: Twelve (7.6%) arterial and 11 (19.3%) venous conduits were found to be occluded, and 8 (10.3%) arterial and 10 (31.3%) venous coronary-coronary grafts were occluded during the observation period. CONCLUSION: Arterial coronary-coronary artery bypass grafting represents an alternative technique that allows complete myocardial revascularization.

Does moderate coronary stenosis affect the fate of the left internal thoracic artery graft?

Abstract Introduction: In this study we try to observe the fate of the left internal thoracic artery grafts that were bypassed to left anterior descending artery with moderate stenosis identified with fractional flow reserve (FFR) technique. Doppler ultrasonography was chosen as a noninvasive screening method. Methods: A total of 30 patients who underwent coronary artery bypass grafting depending on results of the fractional flow reserve between January 2007 and January 2012, were subjected to transthoracic color Doppler ultrasonographic evaluation irrespective of the presence of symptoms, and the presence of a systolic-diastolic flow pattern was investigated using the supraclavicular approach. Results: The left internal thoracic artery graft was found to be functional in 63.3% of patients within a mean period of 35.1±19.7 months between coronary bypass and color Doppler ultrasonography. This period was found to be 29.4±19.6 months in the functional graft group, and 44.7±16.6 months in the dysfunctional graft group (P=0.046). Preoperative complaints of angina were reported to fall from 88.9% to 16.7% in the functional graft group, when compared to the postoperative period (P<0.001), but fell from 90.9% to 36.4% in the dysfunctional graft group (P=0.034). Conclusion: Functional left internal thoracic artery graft rates of the study population were found to be lower than the studies reported in the literature.

Lateral costal artery: clinical importance of an accessory thoracic artery

Abstract The lateral costal artery has sometimes been identified as the culprit for the "steal phenomenon" after coronary artery bypass grafting, besides being occasionally used for myocardial revascularization. Its branches make anastomoses with the internal thoracic artery through lateral intercostal arteries. We aim to report, on three cases, the clinical significance of a well-developed lateral costal artery after coronary artery bypass grafting. Two out of three patients who underwent coronary artery bypass graft surgery in our center between June 2010 and August 2017, applied to us with stable angina pectoris, while the third one was diagnosed with acute coronary syndrome after applying to the emergency department. In coronary cineangiography, in all three cases, a well-developed accessory vessel arising from the proximal 2.5 cm segment of the left internal thoracic artery coursed as far as the 6th rib was detected, and it was confirmed to be the lateral costal artery. A stable angina pectoris in two of the patients was thought to be the result of steal phenomenon caused by the well-developed lateral costal artery. In the two cases with stable angina pectoris the lateral costal artery was obliterated via coil embolization. In the other case with the proximal left anterior descending artery stenosis, before percutaneous coronary intervention, the lateral costal artery was obliterated via coil embolization and the occluded subclavian artery was stented. Routine visualization in cineangiography and satisfactory surgical exploration of the left internal thoracic artery could be very helpful to identify any possible accessory branch of the left internal thoracic artery like the lateral costal artery.

Internal mammary artery with side-branch.

We present the case of a 72-year-old man who underwent off-pump coronary artery bypass grafting of 4 coronary arteries with exclusive use of the left internal mammary artery with a side-branch (mediastinal artery). Before discharge from the hospital, contrast computed tomography angiography confirmed the patency of all 4 coronary grafts. Use of the mediastinal artery side-branch of the internal mammary artery allowed grafting of 4 coronary arteries using only one internal thoracic artery.

Effect of lima harvesting technique on postoperative drainage in off-pump CABG

Abstract Objective: We investigated the effects of pedicled and semiskeletonized left internal mammary artery (LIMA) harvesting techniques on postoperative drainage in patients subjected to off-pump CABG, ignoring other advantages or disadvantages of those techniques. Methods: The present study comprises a total of 160 subjects that underwent coronary artery bypass surgery in our clinic. Data were collected consecutively and retrospectively. An attempt was made to have similar groups in terms of demographic characteristics. Patients that underwent off-pump coronary artery bypass surgery by two surgical teams which differed only in LIMA harvesting technique were dichotomized and compared according to these techniques. The first group (Group 1) consisted of patients in whom LIMA was harvested with surrounding tissues using the pedicled technique. The second group (Group 2) consisted of patients in whom LIMA was harvested using the semiskeletonized technique, with the veins separated from surrounding connective tissues. Results: The mean amount of drainage in the first 24 hours was 706.1±234.2 ml vs. 591±258.8 ml (Group 1 vs. Group 2; P=0.005), the mean amount of drainage in the second 24 hours was 270±133.6 ml vs. 189.4±140.4 ml (Group 1 vs. Group 2; P<0.001), and the mean amount of total drainage was determined to be 976.1±306.9 ml vs. 781.2±335.5 ml (Group 1 vs. Group 2; P<0.001). Conclusion: It was observed that semiskeletonized LIMA presents reduced amount of postoperative drainage in the first and second 24-hour periods and total amount of drainage than pedicled LIMA, independent of pleural integrity.

Antegrade filling of mammary graft by inappropriately revascularized artery.

A 57-year-old man underwent multiple-arterial revascularization including a sequential left internal mammary artery graft to the diagonal branch and left anterior descending coronary artery. Twenty-one months later, repeat angiography due to a new onset of chest discomfort confirmed string sign and nonfunctional proximal left internal mammary artery, and antegrade filling of the distal leg of the sequential graft and the left anterior descending artery through the diagonal branch. This is a known but uncommon angiographic finding that confirms the importance of eventual competitive flow.

The use of skeletonized internal mammary artery for coronary artery bypass grafting / 解放军医学杂志

Objective To summarize the early and mid-term results and experience of skeletonized internal mammary artery (IMA) harvesting in coronary artery bypass grafting (CABG). Methods The clinical data of 56 patients (46 males and 10 females, aged 61.8±7.7 years) having undergone conventional CABG with skeletonized IMA harvesting from Jan. 2014 to Oct. 2015, were retrospectively reviewed. The patients' demographic information, major complications, perioperative related parameters and early postoperative results were collected and recorded. All the patients were followed up postoperative, and major adverse events were collected. Results 59 IMAs were harvested from 56 patients, including 55 left internal mammery artery (LIMA) and 4 right internal mammery artery (RIMA). Bilateral IMAs were harvested in 3 patients. The mean harvesting time was 55.5±13.0 minutes. According to the sequence of harvesting, all the patients were divided into group 1 (first 29 patients) and group 2 (later 27 patients). There was no significant difference in success rate of harvesting or graft flow between two groups (30.4±14.4ml/ min vs 30.3±16.0ml/min, P=0.986). The harvesting time was significantly shorter in group 2 than in group 1 (P=0.001). The mean number of anastomosis was 2.96±0.89. There was no hospital death and severe complications such as myocardial infarction, reexploration for bleeding, or deep wound infection, or non-union of the sternum. All patients were followed up for 1-23 months postoperatively. There was no death or any major adverse cardiovascular events during the follow-up period, except one patient died of acute pulmonary embolism 3 months postoperatively. Conclusion Skeletonized IMA harvesting can be safely and reliably applied to CABG with excellent early and mid-term results.

Cirugía coronaria con doble arteria mamaria interna: efecto en sobrevida a largo plazo / Coronary Artery Bypass Graft Surgery with Double Internal Mammary Artery: Effect on Long-Term Survival

Introducción: El uso de la arteria mamaria interna (AMI) izquierda en la cirugía de revascularización miocárdica (CRM) se asocia con mejor sobrevida alejada libre de eventos cardíacos tardíos; asimismo, el empleo de la AMI derecha como complemento de la izquierda ha mostrado resultados favorables. Sin embargo, aún no queda claro si la revascularización con doble AMI es una mejor opción para los pacientes a largo plazo. Objetivo: Analizar la sobrevida a largo plazo de pacientes con CRM con doble arteria mamaria interna (2AMI) en comparación con pacientes con una AMI (1AMI) en la enfermedad de múltiples vasos. Material y métodos: Se revisaron CRM consecutivas realizadas entre 1996 y 2014 de pacientes con 2AMI (n = 2.098) y con 1AMI (n = 1.659). Se comparó la sobrevida a largo plazo entre los grupos en forma global y entre 485 pares de pacientes ajustados por un puntaje de riesgo. Se generaron modelos de riesgos proporcionales de Cox. Resultados: Los pacientes con 2AMI eran más jóvenes (63,7 ± 9,1 años 2AMI vs. 65,0 ± 9,9 años 1AMI; p < 0,0001). La mortalidad hospitalaria global fue menor en el grupo 2AMI (1,2% 2AMI vs. 4,4% 1AMI; p < 0,0001). A los 10 años, la sobrevida no ajustada fue superior en el grupo 2AMI (82,6% ± 1,8% 2AMI vs. 76,1% ± 1,3% 1AMI; p = 0,001). El análisis de regresión logística de Cox en el grupo global demostró mayor sobrevida en los pacientes con 2AMI (HR 0,71, IC 95% 0,58-0,87; p < 0,001). En el análisis ajustado por puntaje de riesgo, la mortalidad hospitalaria fue similar en ambos grupos (1,6% 2AMI vs. 2,9% 1AMI; p = 0,196). La sobrevida alejada a los 10 años fue significativamente superior en el grupo de pacientes con 2AMI que en el grupo con 1AMI (81,0% ± 4,1% vs. 71,8% ± 2,5%, respectivamente; p = 0,039). Conclusión: Los pacientes con CRM y 2AMI presentaron mejor sobrevida alejada que los pacientes con 1AMI más otro tipo de conducto.

Background: Utilization of the left internal mammary artery (IMA) in coronary artery bypass graft surgery (CABG) is associated with long-term survival free from late cardiac events; moreover, use of the right IMA as a complement of the left artery has shown favorable results. However, it is not yet clear whether double IMA revascularization is a better long-term option. Objective: The aim of this work was to analyze long-term survival of patients with multi-vessel disease undergoing double IMA (2IMA) compared with single IMA (1IMA) CABG. Methods: Consecutive 2IMA (n=2,098) and 1IMA (n=1,659) CABG surgeries performed between 1996 and 2014 were reviewed, comparing overall long-term survival between groups and between 485 pairs of patients matched by propensity score. Cox proportional hazard models were generated. Results: Patients with 2IMA CABG were younger (2IMA: 63.7±9.1 years vs. 1IMA: 65.0±9.9 years; p<0.0001). Overall in­hospital mortality was lower in the 2IMA group (2IMA: 1.2% vs. 1IMA: 4.4%; p<0.0001). At 10 years, unadjusted survival was higher in the 2IMA group (2IMA: 82.6%±1.8% vs. 1IMA: 76.1%±1.3%; p=0.001). Overall Cox logistic regression analysis showed higher survival in patients with 2IMA CABG (HR 0.71, 95% CI 0.58-0.87; p<0.001). In the propensity score adjusted analysis, in-hospital mortality was similar in both groups (2IMA: 1.6% vs. 1IMA: 2.9%; p=0.196), but the 2IMA group still had higher long-term survival at 10 years (2IMA: 81.0%±4.1% vs. 1IMA: 71.8%±2.5%; p=0.039). Conclusion: Patients with 2IMA CABG evidenced better long-term survival than patients with 1IMA plus another type of conduit.

Retroaortic right internal thoracic artery grafting of circumflex artery targets.

BACKGROUND: Retroaortic right internal thoracic artery grafting has failed to gain popularity. We aimed to delineate patient correlates of eligibility, distribution of targets, and effects of target remoteness on outcome and risk of retroaortic bleeding. METHODS: Data of 861 patients undergoing skeletonized bilateral internal thoracic artery grafting (2007-2012) were analyzed according to retroaortic (n = 300) or T-graft configuration. Retroaortic graft subgroups were categorized according to proximal (first obtuse marginal, ramus) or distal (2nd, 3rd, or sequential 1st-2nd obtuse marginal) circumflex artery targets. RESULTS: LOESS curve analyses revealed that taller patients had a higher likelihood of retroaortic grafting. The distribution of 337 retroaortic graft targets (300 patients) was first obtuse marginal in 74.5%, 2nd marginal in 12.4%, ramus in 11.2%, 3rd marginal in 1.9% and sequential 1st-2nd marginal in 12.3%. The success rate in reaching proximal and distal circumflex artery targets was 97% and 30%, respectively, 5-year survival (92.2%) and freedom from major adverse cardiac and cerebrovascular events (85.8%) were comparable between proximal and distal retroaortic graft subgroups. Distal circumflex artery targets had no effect on the occurrence of major adverse cardiac and cerebrovascular events. The incidence of retroaortic bleeding from skeletonized retroaortic grafts was 0.6%. CONCLUSIONS: Taller patients have a greater likelihood of qualifying for retroaortic grafting. This technique is highly reproducible for proximal but not distal circumflex artery targets. Distal circumflex artery targets are not independent correlates of early or late adverse outcomes. The risk of retroaortic bleeding is low despite retroaortic right internal thoracic artery skeletonization.

Internal thoracic artery: anatomical and biological characteristics revisited.

The left internal thoracic artery has become the conduit of choice for coronary artery bypass grafting, due to its superior patency rates at 10 or more years with little or no evidence of atherosclerotic changes. Recent evidence indicates that a second internal thoracic artery graft provides improved results relative to overall survival and major cardiac and cerebrovascular event-free survival, and reduces the need for repeat revascularization. However, the routine use of bilateral internal thoracic arteries is limited due to a perceived higher incidence of deep sternal wound infection. The surgical anatomy, collateral blood supply to the sternum, and biological characteristics of internal thoracic artery conduits are reviewed.

Which is the best graft for the right coronary artery?

Bilateral internal mammary arteries directed to the left coronaries are gaining popularity; an increasing level of evidence nowadays supports this surgical strategy. On the other hand, composite right internal mammary artery, radial artery, and gastroepiploic artery targeting high-grade stenotic lesions in the right coronary artery system may confer improved mid- and long-term patency compared to long saphenous veins. This analysis looks into the evidence comparing data of the third best available conduit for grafting the right coronary artery, and by extrapolating this report, compares total arterial revascularization vs. conventional coronary artery bypass grafting.

Reduced left internal mammary artery blood flow on normal sternal retraction.

The left internal mammary artery is the conduit of choice for bypassing the left anterior descending artery. A 72-year-old man underwent off-pump triple-vessel coronary artery bypass. The left internal mammary artery was harvested with brisk blood flow from the distal artery on completion of harvesting, but normal sternal retraction with a Medtronic OctoBase retractor led to cessation of flow. A vein graft was utilized for the left anterior descending artery, and the internal mammary artery was grafted to the first diagonal branch. Computed tomography-angiography on postoperative day 5 demonstrated no possible cause of the reduced flow on sternal retraction.

Right-sided reverse T composite arterial grafting to complete revascularization of the right coronary artery / Enxerto arterial composto reverso T do lado direito para completar a revascularização da artéria coronária direita

Complete arterial revascularization for the right coronary artery is underused mainly due to technical issues. Herein we report on a new approach for complete arterial revascularization of arterial revascularization for the right coronary artery branches. Complete arterial revascularization for the right coronary artery revascularization was performed in 8 patients using a reverse T composite arterial graft. None of the patients suffered perioperative myocardial infarction. All patients underwent noninvasive coronary imaging, displaying an early patency rate of 100%. Complete arterial arterial revascularization for the right coronary artery revascularization using a reverse T graft offers a new paradigm with enhanced technical flexibility in performing all arterial myocardial complete revascularizations in selected patients.

Revascularização arterial completa para a artéria coronária direita é subutilizada, principalmente devido a problemas técnicos. Nós relatamos uma nova abordagem para a revascularização arterial completa para os ramos da artéria coronária direita. Revascularização arterial completa da artéria coronária direita foi realizada em 8 pacientes usando um enxerto T arterial composto inverso. Nenhum dos pacientes sofreu infarto do miocárdio perioperatório. Todos os pacientes foram submetidos a exame de imagem não invasivo coronária não invasiva, exibindo taxa de patência precoce de 100%. Revascularização arterial completa da artéria coronária direita com enxerto inversa T oferece um novo paradigma com maior flexibilidade técnica na execução todas as revascularizações arteriais completas do miocárdio em pacientes selecionados.

Análise da medida de fluxo por tempo de trânsito da artéria torácica interna direita anastomosada para a artéria interventricular anterior comparada com a artéria torácica interna esquerda / Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

Introdução: Avaliamos por meio da medida de fluxo por tempo de trânsito o desempenho das artérias torácicas direita e esquerda quando utilizadas como enxerto para revascularização da artéria interventricular anterior. Métodos: Cinquenta pacientes submetidos à operação para revascularização do miocárdio sem circulação extracorpórea foram divididos em dois grupos. No grupo A, os pacientes receberam enxerto de artéria torácica interna direita para o ramo interventricular anterior. No grupo B, os pacientes receberam enxerto de artéria torácica interna esquerda para o mesmo ramo. Ao término da operação, o fluxo foi avaliado por meio da medida de fluxo por tempo de trânsito. Resultados: No grupo A, idade média foi de 60,6±9,49 anos. A média de peso e altura do grupo foi de 80,4±10,32 Kg e 169,2±6,86 cm. A média de pontes por paciente neste grupo foi de 3,28±1,49. O fluxo médio e a resistência distal obtidos na artéria torácica interna direita foi de 42,1±23,4 ml/min e 2,8±0,9 respectivamente. No grupo B, a idade média foi de 59,8±9,7 anos. A média de peso e altura deste grupo foi de 77,7±14,2215,7 Kg e 166,0±8,2 cm. A média de pontes por paciente neste grupo foi de 3,08±0,82. O fluxo médio e a resistência distal observados neste grupo foi de 34,2±19,1ml⁄min e 2,0±0,7. Não houve óbitos nesta série. Conclusão: A artéria torácica interna direita apresentou um comportamento similar ao da artéria torácica interna esquerda quando anastomosada ao ramo interventricular anterior da coronária esquerda. Não houve diferença estatística entre a medida de fluxo obtida entre ambas as artérias. .

INTRODUCTION: We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery. Methods: Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time. Results: In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series. Conclusion: Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries. .