Retrograde Cardioplegia Through the Coronary Sinus Philippe Menaschk, M.D., and Armand Piwnica, M.D.

ABSTRACT We describe a balloon catheter designed for perfusing cardioplegic solution retrograde through the coronary sinus during cardiac surgical procedures. Empha- sis is placed on features that increase both the safety and the effectiveness of this alternative means of delivering cardioplegic solution.

Over the past years, retrograde coronary sinus perfusion has emerged as an attractive means of delivering cardio- plegic solution during aortic cross-clamping. Both ex- perimental [l-31 and clinical [4, 51 studies have docu- mented the ability of retrograde cardioplegia to achieve adequate myocardial preservation during elective isch- emic arrest. The two major concerns that have been raised about the use of this technique are injury to the coronary sinus and poor protection of the right ventricle. On the basis of a six-year clinical experience that now encompasses more than 500 patients, we have devel- oped a specific retroperfusion catheter that is intended to circumvent these shortcomings.

Operative Technique Cardiopulmonary bypass is established between the two individually cannulated venae cavae and the ascending aorta. Care is taken to insert the inferior vena cava can- nula into the posterior part of the right atrial free wall, close to the interatrial groove. After induction of sys- temic cooling, both venae cavae are snared and a short (3 cm) atriotomy is made in the anterior part of the right atrial free wall, parallel to the atrioventricular sulcus. This approach provides direct exposure of the coronary sinus ostium.

Immediately after aortic cross-clamping (or even in the last moments that precede application of the aortic cross- clamp), a balloon-tipped catheter is advanced into the terminal portion of the coronary sinus. The balloon is gently inflated with saline solution until it occludes the coronary sinus orifice, and infusion of cardioplegic solu- tion is initiated. The surgical procedure is then carried out in the usual way.

Whenever cardioplegic solution has to be reinfused, it can be done without interrupting the operation because the catheter is self-secured into the coronary sinus by means of balloon inflation. In aortic valve procedures, adequate drainage of retroperfused cardioplegic solution is ensured by the opened ascending aorta and the right

From the Department of Cardiovascular Surgery, Hapital Lariboisiere, Pans, France.

Accepted for publication Dec 11, 1986.

Address reprint requests to Dr. Menasche, Service de Chirurgie Car- diovasculaire, 2, rue Ambroise Par&, 75010 Paris, France.

atriotomy. In mitral valve or coronary artery bypass grafting operations, an aortic vent allows perfusate flow- ing back through the coronary ostia (predominantly the let3 coronary ostium) to escape from the aortic root.

Immediately before removal of the aortic cross-clamp, the balloon is deflated, the catheter is withdrawn, and the right atriotomy is closed with a running suture. Be- fore the final knots are tied, the caval tapes are released to ensure the removal of air from the right heart cham- bers. With some experience, the whole procedure of ret- rograde coronary sinus perfusion takes but a few min- utes and is neither more complicated nor more time- consuming than direct cannulation of the coronary ostia in patients with severely calcified aortic stenosis.

Catheter Design For a long time, we used a Foley urinary catheter and obtained satisfactory results overall. The major concern about using this catheter is the spherical shape of its balloon. Balloon inflation is likely to occlude the more distal branches of the sinus that may drain as close as 5 mm from its entry into the right atrium [4], thus prevent- ing effective retroperfusion of the right ventricle.

For this reason, we developed a pear-shaped balloon (Peters Laboratories, B.P. 46-93302 Aubervilliers Cedex, France) that nicely fits the funnellike configuration of the coronary sinus orifice (Figure). Only the distal soft end of this high-pressure polyvinyl chloride catheter is ad- vanced into the lumen of the venous conduit; this is necessary to prevent the catheter from being pulled into the right atrial cavity during cardioplegia infusion. In this way, balloon inflation does not jeopardize the termi- nal tributaries of the coronary sinus and hence does not impede the distribution of cardioplegic solution to the right-sided cardiac structures. Further, the predomi- nantly intraatrial location of the inflated balloon mini- mizes mechanical stress to the underlying venous wall. An additional feature of the catheter design is the crimp- ing of the balloon material. This measure enhances self- maintenance of the catheter in the proper position dur- ing cross-clamping.

The catheter is connected to the cardioplegia line by means of a three-way stopcock to which a pressure line can be attached easily for monitoring perfusion pres- sure. Maintenance of perfusion pressure in the range of 40 mm Hg is mandatory for avoiding coronary venous injury. Assuming that the pressure drop across the catheter is approximately 10 mm Hg, perfusion pres- sure, as measured at the proximal end of the catheter, should not exceed 50 mm Hg. In fact, we, like others [2], have found that under conditions of cold cardioplegic arrest, the pressure-flow relationship in the venous sys- tem is fairly constant. Therefore, in practice, we have

214 Ann Thorac Surg 44.214-216, Aug 1987

215 How to Do It: Menasche and Piwnica: Retrograde Cardioplegia through Coronary Sinus

Retroperfusion catheter. The balloon is shown partly inflated to make the distal end of the catheter more clearly visible. When it is maxi- mally inflated, the balloon has a pear shape that fits the configuration of the coronary sinus orifice nicely.

discontinued the monitoring of perfusion pressure and simply fix the flow rate of the cardioplegia delivery sys- tem to approximately 50 muper minute, which ensures that distal perfusion pressure will remain within the ap- propriate range. The resulting length of the period of cardioplegia infusion (20 minutes for the initial 1-liter infusion) is more an advantage than a disadvantage, in particular because of enhanced washout of toxic by- products of anaerobic metabolism and more efficacious equilibration between cardioplegia ingredients and the intracellular milieu.

As far as cost-effectiveness is concerned, it is worth mentioning that for adults, a single size of the catheter (12F) fits all coronary sinus orifices because of the com- pliance of the balloon.

Comment When we started to use retrograde coronary sinus perfu- sion, our primary concern was to avoid direct cannula- tion of the coronary ostia and its attendant risks in pa- tients operated on for aortic valve disease [6] . In this population, retrograde cardioplegia was shown [4] to afford a level of intraoperative myocardial protection similar to that provided by antegrade coronary perfu- sion. Subsequently, it turned out that coronary sinus cardioplegia offered additional technical advantages with clinical relevance over the antegrade approach, in particular, the ability to repeat cardioplegia infusions without interrupting the surgical procedure and better atrial cooling.

At present, there is a growing body of experimental evidence that retrograde cardioplegia might also be ad- vantageous in patients with severe coronary artery ob- structions or stenoses because of its alleged ability to avoid the maldistribution of hypothermia and cardiople- gia that is associated with antegrade techniques [2, 31. To the best of our knowledge, however, the only clinical study [5] that has addressed this issue failed to docu- ment any difference between the two routes of cardio- plegia delivery. Currently, we consider that aortic valve procedures still represent the elective indication for coronary sinus cardioplegia. In the setting of bypass op- erations, it is likely that only certain subsets of patients are expected to benefit from retrograde techniques. These subsets may include patients with total coronary artery occlusion and poor collaterals, and patients who are reoperated on with still patent saphenous vein grafts, because in these cases, aortic root cardioplegia may cause distal embolization of atheromatous material present in the venous conduits. However, that retro- grade cardioplegia is a superior approach in these situa- tions still needs to be confirmed clinically.

In the context of retrograde techniques, some authors [7] have advocated the use of right atrial cardioplegia. The major concern with this approach is the distention of right-sided cardiac cavities. In our opinion, this con- cern overwhelms the theoretical advantage of avoiding direct cannulation of the coronary sinus.

Provided that traumatic maneuvers and perfusion pressures in excess of 40 mm Hg are avoided, retrograde coronary sinus perfusion is a safe technique. Among a study population of more than 500 patients, we have encountered 3 with coronary venous injury. All 3 in- juries occurred during our very early experience using the Foley catheter. In 1 patient, the balloon was ad- vanced too far into the coronary sinus and its excessive inflation caused rupture of the venous wall. This compli- cation can be prevented by gently inflating the balloon until it occludes the lumen of the coronary sinus, but without an excessively tight fit between the catheter and the venous vessel. Further safety should be provided by the catheter described here because the proximal part of the inflated balloon sits around the intraatrial rim of the coronary sinus orifice, thus reducing the risk of in- jury to the underlying venous wall.

216 The Annals of Thoracic Surgery Vol 44 No 2 August 1987

In the 2 other patients, a tear of the great cardiac vein occurred as a consequence of a too high perfusion pres- sure. For technical reasons, the pressure had not been accurately controlled. Since then, this complication has not been observed because care is taken not to allow the flow rate of the cardioplegia delivery pump to rise above 50 mYmin. The 3 venous injuries were repaired success-

To deal with the problem of right ventricular preserva- tion, Guiraudon and associates [5] proposed use of a Foley catheter without inflating the balloon to ensure adequate retroperfusion of distal branches of the coro- nary sinus. The catheter is anchored into the sinus by means of a pursestring suture that is placed around the rim of the coronary sinus orifice. The drawback of this technique is that it makes the procedure more com- plicated.

We think that balloon inflation is a simpler means of achieving effective maintenance of the catheter in its proper position, provided the balloon design is such that it does not impede retrograde flow into vessels supply- ing right-sided cardiac structures. This reasoning is sup- ported by the preliminary results of an ongoing study showing that postoperative right ventricular function, as assessed by radionuclide testing, is unchanged from

fully.

preoperative control levels in patients undergoing coro- nary sinus cardioplegia.

References 1.

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Solorzano J, Taitelbaum G, Chiu RC-J: Retrograde coronary sinus perfusion for myocardial protection during cardiopul- monary bypass. Ann Thorac Surg 25901, 1978 Gundry SR, Kirsh MM: A comparison of retrograde cardio- plegia versus antegrade cardioplegia in the presence of coro- nary artery obstruction. Ann Thorac Surg 38:124, 1984 Bolling SF, Flaherty JT, Bulkley BH, et al: Improved myo- cardial preservation during global ischemia by continuous retrograde coronary sinus perfusion. J Thorac Cardiovasc Surg 86:659, 1983 Menasche P, Kural S, Fauchet M, et al: Retrograde coronary sinus perfusion: a safe alternative for ensuring cardioplegic de- livery in aortic valve surgery. Ann Thorac Surg 34.647, 1982 Guiraudon G, Campbell CS, McLellan DG, et al: Retrograde coronary sinus versus aortic root perfusion with cold cardio- plegia: randomized study of levels of cardiac enzymes in 40 patients. Circulation 74:Suppl 3:105, 1986 Pennington DG, Dincer B, Bashiti H, et al: Coronary artery stenosis following aortic valve replacement and intermittent intracoronary cardioplegia. Ann Thorac Surg 33:576, 1982

L . Fabiani J-N,-Deloche i, Swanson J, Carpentier A Retro- grade cardioplegia through the right atrium. Ann Thorac Surg 41:101, 1986