Total Arterial Myocardial Revascularization Using New Composite Graft Techniques for Internal Mammary and/or Radial Arteries Conduits

Perioperative and clinical-angiographic late outcome of total arterial myocardial revascularization according to different composite original graft techniques

Total arterial myocardial revascularization (TAMR) is advisable because of the excellent long-term patency of arterial conduits. We present early and midterm outcomes of five different surgical configurations for TAMR. Between January 1998 and May 2004, 112 patients (aged 56.5 +/- 4.5 years, 20% female) with three-vessel disease underwent TAMR. The internal mammary arteries (IMAs) were harvested in a sketelonized fashion. The surgical techniques for TAMR consisted in Y or T composite grafts (n = 88, 78%) constructed between the in situ right IMA (RIMA) and the free left IMA (LIMA) graft (n = 58) or the radial artery (n = 30) (RA) in three different configurations. The other techniques consisted in T- and inverted T-graft (n = 24, 22%) constructed between the RA conduit and the free LIMA graft in two different configurations. The mean follow-up time was 40 +/- 23 months. Postoperative angiographic control was performed in 76/111 (70%) patients. Overall, 472 arterial anastomoses (average 4.2 per patient) were performed. One (0.9%) patient, undergoing the inverted T-graft technique, died on postoperative day 2. Another patient (0.9%), undergoing the lambda-graft technique using both IMAs and RA, suffered a new myocardial infarction probably due to RA conduit vasospasm. One week after surgery, after the transthoracic echocardiographic Doppler with adenosine provocative test, the coronary flow reserve (CFR) at the LIMA and RIMA main stems were 2 +/- 0.4 and 2.4 +/- 0.3, respectively. At 12-month follow-up, after adenosine provocative test, the CFRs at the LIMA and RIMA stems were significantly higher than the values at 1 week after surgery within the same group; (LIMA)CFR (1 week) 2.4 +/- 0.3 (12 months) vs 2 +/- 04 (1 week), P = 0.002; (RIMA)CFR 2.58 +/- 0.4 vs 2.4 +/- 0.3, P = 0.001. The CFR at the RIMA main stem was higher in all measurements within the same group than in the LIMA main stem, but not significantly. In one patient undergoing the lambda-graft technique using both IMAs, the RIMA was found to have a string sign. Postoperative angiography in 50 patients showed that the patency rate for the LIMA was 100%, for the RIMA 97.3%, and for the RA 96.7%. Angiography at 3-year follow-up in 76 patients documented excellent patency rates of the LIMA (97.4%), RIMA (95%), and RA (87%). Survival at 7 years was 92.5%, event-free survival 89.3%, and freedom from angina 94%. Total arterial myocardial revascularization using different surgical configurations is safe and effective. The use of composite arterial grafts provides excellent clinical and angiographic results, with a low rate of angina recurrence and late cardiac events. These configurations allow for complete arterial revascularization.

Surgical revascularization of coronary bifurcations employing a single arterial graft according to the "omega-anastomosis" technique: initial experience

OBJECTIVES

The aim of this study was to evaluate the early postoperative outcome in patients undergoing "omega-anastomosis" construction, a technique that permits revascularization of coronary bifurcations employing a single arterial graft.

MATERIALS AND METHODS

Between January 2000 and March 2002, omega-anastomosis was employed in 12 patients. The main indication for omega-anastomosis construction was the presence of a significant stenotic lesion involving one of the coronary tree's bifurcations, presenting a relevant secondary branch. There were ten men and two women, with a mean age of 55.4 +/- 4.3 years (range 48 to 66). The omega-anastomosis was constructed employing a single arterial graft (internal mammary artery or radial artery) effectively tailored to obtain a bi-petal shape and anastomosed to the coronary bifurcation according to a three-foliate anastomosis. All patients underwent postoperative coronary angiography.

RESULTS

There were no hospital deaths, neither ECG nor enzymatic alterations. One patient was reoperated for excessive bleeding. The mean aortic cross-clamp time and duration of CPB (cardiopulmonary bypass) were 64 +/- 18 minutes (range 45 to 108) and 89 +/- 26 minutes (range 67 to 135), respectively. Thirty-four arterial conduits were used: 12 LIMA, 12 RIMA, and 10 RA. Twelve omega-anastomoses were constructed, in six patients employing the RA, and in six other patients employing one of the internal mammary arteries (IMAs). Five left Y-grafts between the in situ LIMA and free LIMA graft and one right Y-graft between the RIMA and RA were constructed. The mean ICU stay was 14.4 +/- 5.7 hours. The postoperative coronary angiography revealed a good patency of the "omega-anastomosis." Transthoracic color Doppler echocardiography (TTECD) demonstrated a normal IMAs flow pattern in all cases.

CONCLUSIONS

We define the reported configuration as a possible surgical alternative to achieve total arterial myocardial revascularization in multi-vessels patients, associated with excellent postoperative outcome that should be part of the coronary surgical armamentarium.

In situ retrocaval skeletonized right internal thoracic artery anastomosed to the circumflex system via transverse sinus: Technical aspects and postoperative outcome

BACKGROUND

The aim of this study was to investigate whether, by using the in situ right internal thoracic artery via the transverse sinus (eventually retrocaval), both the proximal and distal major branches of the circumflex system could be grafted and to evaluate the early and late outcome in these patients.

METHODS

Between January 1997 and March 2002, 452 consecutive patients underwent grafting of the circumflex system with the in situ skeletonized right internal thoracic artery routed via the transverse sinus. The mean age was 62.4 +/- 10.3 years. A mean of 2.2 +/- 0.3 arterial grafts per patient were used, and 271 (60%) patients underwent total arterial myocardial revascularization. At 3 months after surgery, 86 patients (right Y or T graft) underwent echo color Doppler imaging before and after an adenosine provocative test. The mean follow-up was 27 +/- 8 months.

RESULTS

The success rate of skeletonized right internal thoracic artery grafting to the circumflex system branch was 100%. There were 15 (3.4%) hospital deaths. In 116 patients who underwent postoperative angiography, the total patency rates of the right and left internal thoracic arteries were 94% and 96.6%, respectively. Strong predictors for nonfunctional internal thoracic artery grafts were a small internal thoracic artery caliber (P <.001), recipient coronary artery diameter less than 1.5 mm (P =.012), stenotic lesions of less than 60% (P =.016), and diffuse stenotic lesions (P =.015) of the recipient coronary artery. In 86 patients who underwent postoperative echo color Doppler imaging, the flow reserves at the main stem of the left and right internal thoracic arteries were 2.24 +/- 0.5 and 2.48 +/- 0.6, respectively. Cumulative actuarial survival at 3 years was 96.3%, and event-free cumulative survival was 93%. The Cox model revealed a left ventricular ejection fraction of less than 35% (P =.016), age greater than 70 years (P =.025), New York Heart Association grade greater than III (P =.0019), nontotal arterial myocardial revascularization (P =.002), and the preoperative presence of more than 1 ischemic area (P <.001) as strong predictors for poor overall cumulative event-free survival.

CONCLUSIONS

The skeletonized right internal thoracic artery, placed via the transverse sinus and eventually retrocaval, can reach most branches of the circumflex system and is associated with an excellent patency rate. The predictors for poor overall event-free survival seem to be similar to those of the general population undergoing conventional coronary artery bypass grafting. Use of bilateral internal thoracic arteries and in situ right internal thoracic artery grafting via the transverse sinus offers the possibility of various configuration constructions, making possible total arterial myocardial revascularization with a minimum number of arterial conduits.

Off-pump total arterial myocardial revascularization according to the right Y-graft configuration

OBJECTIVES

The aims of this study were as follows: 1) to evaluate the early outcome of the off-pump total arterial myocardial revascularization according to the right y-graft (lambda-graft) configuration and 2) to compare baseline flow and maximum flow between patients undergoing on-pump and off-pump right y-graft (RYG) construction.

METHODS

Between December 1998 and January 2001, 47 patients (Group I) and 20 patients (Group II) with three vessel disease underwent on-pump and off-pump coronary artery bypass graft (CABG) respectively according to the RYG configuration. The mean age was 55.5 +/- 4.7 years and 55 +/- 6.4 years in Groups I and II, respectively. The RYG was constructed employing both internal mammary arteries (IMAs) only, in 21 and 8 patients in Groups I and II, respectively, presenting proximal-middle third stenosis of the left anterior descending artery (LAD) and right coronary artery (RCA). The modified RYG configuration employing both IMAs and radial artery (RA) was performed in 26 and 12 patients in Groups I and II, respectively, presenting middle-distal third stenosis of the LAD and distal stenosis of the RCA or posterior descending artery stenosis. Postoperatively all patients underwent transthoracic echo color-Doppler (TTECD) contrast enhanced (by Levovist) before and after adenosine provocative testat one week and three months after operation.

RESULTS

There were no hospital deaths. The mean mechanical ventilation was significantly different in Group I versus Group II patients, 18 +/- 4.4 hours versus 13 +/- 5.7 hours, respectively (p = 0.041). The mean intensive care unit stay was 1.5 +/- 0.6 days in Group I and 1 +/- 0.4 days in Group II (p = 0.033). There were no differences between Groups I and II regarding the IMA diameter, mean velocity, and mean flow. At follow-up time, 6 +/- 2.4 months after the surgical procedure, all patients were alive and free of angina. The coronary flow reserve (CFR) at LIMA main stem was significantly higher at three months when compared to the values at one week after the surgical procedure within the same group, (LIMA)CFR (three months) = 2.37 +/- 0.6 versus (LIMA)CFR (one week) = 2.07 +/- 0.4 (p = 0.005) in Group I and (LIMA)CFR (three months) = 2.4 +/- 0.4 versus (LIMA)CFR (one week) = 2.06 +/- 0.3 (p = 0.004) in Group II. Similarly, the CFR at RIMA main stem were significantly higher at three months when compared to the values at one week after the surgical procedure: (RIMA)CFR (three months) = 2.47 +/- 0.7 versus (RIMA)CFR (one week) = 2.1 +/- 0.5 (p = 0.004) in Group I and (RIMA)CFR (three months) = 2.48 +/- 0.5 versus (RIMA)CFR (one week) = 2.08 +/- 0.4 (p = 0.008) in Group II.

CONCLUSION

The flow dynamic data, almost identical between patients undergoing off-pump and on-pump total arterial myocardial revascularization (TAMR) according to the RYG configuration, demonstrate that this technique can be applied with excellent results without the employment of cardiopulmonary bypass in selected coronary artery disease patients.

Lambda graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: flow dynamics

BACKGROUND

The aim of this study was to evaluate the outcome and flow dynamics of the lambda graft configuration, relative to a second arterial graft.

METHODS

From 1998 to 2000, 47 patients (mean age 55.5 +/- 4.7 years) with triple-vessel disease underwent arterial revascularization using the lambda graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the lambda graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the lambda graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation.

RESULTS

There were no hospital deaths. Overall, 47 lambda grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [(LIMA)CFR = 2 +/- 0.3 vs 2.3 +/- 0.3 (p = 0.002) and (RIMA)CFR = 2.2 +/- 0.4 vs 2.5 +/- 0.3 (p = 0.009) in group I, and (LIMA)CFR = 2.12 +/- 0.33 vs 2.4 +/- 0.35 (p = 0.005) and (RIMA)CFR = 2.17 +/- 0.32 vs 2.52 +/- 0.26 (p = 0.001) in group II]. At 3 months versus 1 week, the (RIMA)diameter(i) (mm) at rest was 1.69 +/- 0.32 versus 1.48 +/- 0.2 (p = 0.015) in group I and 1.66 +/- 0.3 versus 1.47 + 0.2 (p = 0.01) in group II. At 6 +/- 2.4 months, all patients were free of angina.

CONCLUSIONS

These data, almost identical for free LIMA and RA to RIMA using the lambda graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.