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Total and Complete Arterial Revascularization Using Bilateral IMAs

Wednesday, December 16, 2015

A 65-year-old man was admitted with acute inferior wall myocardial infarction, and echo revealed moderate left ventricular dysfunction. He was stabilized on medical treatment. An angiogram showed severe triple vessel disease, and the authors recommended anaortic CABG using bilateral internal mammary arteries. Both internal mammary arteries were harvested and partially skeletonized. LIMA-RIMA composite Y grafts were constructed using 8-0 prolene sutures. The left atrial appendage was plicated to facilitate graft placement. The following anastomoses were performed: the RIMA was placed to the ramus, the OM1, and the PDA; the LIMA was placed to diagonal 1, diagonal 2, and the LAD. In effect, a total arterial complete revascularization was performed using bilateral internal mammary arteries.

 

Comments

Very nice grafting strategy and surgical handsome. It falls timely with release of STS guidelines to arterial CABG. 1) do you think that the PDA anastomosis can be peformed as a T anastomosis as to spare the conduit length and offer more straight side-arm RITA course? Performing T-anastomosis is not an easy task on the lower OM and inferior branches especially on beating condition and by implementing arterial conduits. Nevertheless, I would argue that T-anastomosis in lower OM and infrior branches does offer some mechanistic benefits. 2) an alternative layout would be use RITA as inter-coronary bridge between PDA, OM,D1, LITA to LAD AND D2, and conecting RITA and LITA by a kissing anastomsis that I call Tripode composite grafting, of course adapting the abastomoses sequences to OPCAB requierements. This tactic may spare both conduits length. 3) using shunt does have more advantage than just preventing ischemia. I even use shunt on arrested heart juste because it favourably shapes the anastomosis and shifts occurrence of overlooked technical flaws towsrds zero. Sometimes, putting a shunt into side ITA arteriotomy greatly facilitate side-to-side anastomoses. Again, tanks having shared your elegant surgical video. Cordialky
Elegant technique. The concern I have is that you are relying on a single inflow source for the composite BITA supplying total coronary circulation with 6 distals. How confident are you that competitive flow will not result in graft failure, intracoronary bridging, or steal to the runoff myocardial territory with the least resistance? Have you had to rescue any cases with a graft from a second inflow source? Any long term follow-up on patency using your strategy for so many distals?
I think that the best physiological approach to surgical revascularisation is to resort a "double-inflow" source as I described in detail in a comment to the video " Can a Single ITA Composite Graft Adequately Supply the Heart?" (http://www.ctsnet.org/article/can-single-ita-composite-graft-adequately-supply-heart). The latter is the reason I try to treat right and left coronary systems separately, should it requires double-sided composite grafting (http://www.ncbi.nlm.nih.gov/pubmed/25714223). The so-called "competitive flow" is an amalgam over-used as is the case with "ITA spasm". From a physiological point of view, what we call competitive flow does have multiple physiological components such as systolic back-flow in septal barnches and second order epicardial branches (such as diagonal). the latter may be the reason of separate ITA failure aside the stenosis degrees of the hosting artery (http://www.ctsnet.org/jans/frequency-and-predictors-internal-mammary-artery-graft-failure-and-subsequent-clinical-outcomes). Therefore, the role of competitive flow is put forward regarding composite grafting in comparaison to separate grafting. Composite grafting has its own set of advantage as mentioned in this video , specially minimizing ascending aorta manipulations. The further direction is to determine which composite grafting layout could better restore coronary reserve and resist specifications of "Coronary Circulation". In other words, reaching a surgical revascularisation closer to the normal coronary physiology that I would call " Ad-Physiological" bypassing. Cordially
I'm not sure I understand all of the lingo you have named for your coronary bypassing and physiology. This patient's coronary revascularization could have been easily accomplished surgically with an all arterial off-pump, no touch aorta, bilateral IMA (in-situ with two inflow sources: left and right subclavian arteries) +/- radial artery composite (anastomosed from either the RIMA or LIMA) if additional length is needed to reach all distal targets. Regarding your comment to the contrary, competitive flow and graft spasm are real physiologic problems resulting in graft failure documented throughout the literature. If they are "overused" terms, it's because they describe the phenomena, they are understood by those surgeons performing revascularization, and no better terminology has been proposed nor stood up to scientific scrutiny,
We have been routinely using this technique now almost one and half year with bilateral IMA Usage of near 100%, we are able to achive our goal of total arterial revascularization with bilateral IMA only with OPCABG . We are routinely using intracoronary shunts and if required shunt in conduits as well (Lima or Rima ) . It was initial part that there were patients with graft failure but most of it reflected on operation table itself I believe Learning curve . The sequencing of anastomoses is very important . All the anastomoses are done as parallel anastomoses with each anastomoses slightly bigger then previous anastomoses to avoid gradient and the last anastomoses to pda is done as retrograde or antegrade anastomoses. In initial experience we had to use vein as I extension to RIMA for reaching PDA OR RCA . And we use nikorndil or milrinone infusion to avoid IMA spasm.
The completness of surgical revascularisation is just one piece of the big "puzzle " complete revascularisation". While PCI continues to progress in device conception and physiological goal revascularisation, we surgeons do not see further than "technical feasability" & " patency". The fact (being also well documented by scientific litterature) is that functionnal features of our " Aorto-Coronary" bypassing is under normal physiological capabilities, even striving on the coronary reserve by disturbing normal coronary systolic pattern and delaying rapid coronary-perfusion in early diastol, a pathophydiological "lingo" well documented and known by hemodynamic men. With the continous efforts on better preserving SVG, and moving twoards more arterial grafting, the pathophysiological aspects of Aorto-Coronary bypassing will be more highlighted in the next future, and more attentions will be paid to the pathophysiological details. Therefore, digging deeply more than epicardial technical aspects do lead discussing, conceiving, and resorting futures directions in CABG, which is one of the aim of such interactive forums feeded by mind-related hands. Resolving the competition flow and graft spasm issues do require steps beyond their recognition and documentation. Analysing different possible factors involved in occurence of adverse phenomena such as graft spasm or competition flow does be evolving and adaptable to ongoing knowledge making relative the notion of surgical "understanding" of these phenomena. I think that continous infusion of low-dose milrinone is a very good option that should be started at the end of the procedure. The only issues we had encountered is occurence or aggravation of intra-pulmonary shunts mandating its withdrawal (10% of cases). Do you have specific criteria to select ACB vs milrinone according to patients co-morbidities? What medication class do you use to switch off entrally IV milrinone? Do you use postoperative heparine for your all arteial CABG patients? What is your policy in regard of dual anti-thrombotic therapy in the setting of all arterial revasculsrisation? Cordially.
We are using milrinone in case of bad vessels ,bad lv and especially if Lima Rima is small in size and it's used only for first 12 hrs . We have seen significant change is size of conduits . Since we are using BIMA irrespective of age ,gender,lv function or bad vessels ,we find usage of milrinone extremely helpful in bad lv , small conduits , female patients . But still our milrinone usage is only in 20-30 % of patients . We are using low molecular weight heparin for three days , acute coronary syndrome and bad vessels , bad lv function . We use dual anti-platelets in all patients but continue same for one year only in acute coronary syndrome patients or when cabg done in post PTCA patients .
Thanks for providing complementary information. Milrinone is expensive, but very effective as first line conduit dilator. The latter may have some beneficial preventive effects to counter-act non occlusive inflammatory vascular disease due to perioperative stress or extra corpporeal circulation. As you proceed with OPCAB, do you advise reversing completly heparin, or 1/2, or 3/4 of estimated remaining heparin in the case of all arterial grafting? I agree that we should rely more on low molecular weight heparin to reduce hazard of occurence of fruste form of allergia to heparin, nevertheless, I heard that LMWH have some inherent anti thrombotic effects. The latter does mean that we should use triple anti platel therapy for some postoperative days. I did not noticed an increase in delayed resternotomy or secondary thoracic drainage, and I appreciate aknowlegde your and others experiences. I rely on peripherial ACB to rely milrinone, except patients requiering anti angina therapy as to avoid arterial accutumance to TNG. Conduit remodelling may take more than 3 months, and I try to keep dual anti platel therapy as long as possible within the first year for SVG and arterial conduits, provided stomach plays in tolerance. Cordially
We reverse heparin completely at end.We use ACB ,betaclocker,statins in all patients postoperatively.I agree graft remodelling in Y graft takes about three months so we keep nitrates till that time . Do you have any experience of reverse terminal anatomosis in arterial graft (PDA and RCA).
My policy is to create a dual source revascularisation when ever possible for many physiological and anatomical reasons. I normally perform a composite graft to the anterior and left lateral wall, and treat RCA branches with posterior branches separately (up to performing double sided composite grafting). In majority of cases, I avoid parallel anastomosis to PDA, as to better print a graft course. I performed some reverse terminal anastomoses on OM branches when faced to non linear pattern of distal anastomoses sites, but by resorting more reverse T composite grafting I overcome the tactical need to reverse anastomosis. cordially
Congratulations Sarju fantastic operation but my impresión looking the angiogram that this patient have a very big LAD if it is the case i dont put in any risk the left internal mammary alone to the Lad and if it is really necesary i use the rigth mammary as inflow to the others vessels with the rest of rima and vein non touch
LIMA-RIMA (Y) technique of total arterial revascularization is one of the good method of revascularization strategies, but this technique should not be used in all patients. The two inflows are always better than having one LIMA inflow supplying all left and right coronary territories consisting 4- 6 distal anastomosis. There is a saying, " do not put all eggs in one basket". Angiographic anatomical dispositions of coronary arteries as well as percentage of proximal stenosis in the native vessels and the size of the heart are very important for minimizing the flow competitions between the native vessels and the conduit flow and to minimize the inappropriate tension on the conduit causing poor distal run off, especially on the RIMA arm supplying the lateral and inferiorly located coronary branches. To my view, it is inappropriate and can be harmful to use one particular technique for every patient. In my patient populations, I prefer to use skeletonized pedicle bllateral IMA's plus minus radial artery for total arterial revascularization. In some selective and angiographically suitable patients, I use LIMA-RIMA (Y) configuration.
Nice to have so many "anaortic" OPCAB fans. I agree with the above sentiments - two in-flows are better. We (Sydney Heart and Lung Surgeon, Australia) utilise bilateral IMAs and a radial in almost all cases. The LIMA to the LAD, with a RIMA/radial tandem/extension graft via the transverse sinus to the lateral and inferior walls. Multiple sequential anastomoses are much easier on the radial artery than on the RIMA. We also routinely resect the LA appendage with a heavy (black) Covidien tri-stapler, which makes grafting technically easier and mitigates the stroke risk from peri-operative AF and going forward as the patient ages. FFR is important to ensure that distals are placed on arteries with significant stenoses only. On-table graft flow assessment is important too, as is the routine use of coronary shunts. However, not all patients are suitable for BIMAs (subclavian disease, AV fistulas for CKD, obesity and poor diabetic control etc.). We tend to use LIMA/radial "T" grafts for theses patients. Milrinone is a great vasodilator and to improve cardiac output and distal organ perfusion.

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