I removed together with the main trunk of the pulmonary

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1 Replacement of the Aortic Valve With a Pulmonary Autograft: The "Switch" Operation Donald Ross, FRCS Harley Street Clinic, London, England The transfer of the patient's own pulmonary valve to the aortic position developed from our earlier work with aortic homografts. The valve shows no progressive tissue failure and offers the prospect of a permanent valve replacement for young people. Like homografts, the valves can be inserted in the subcoronary position or as a root replacement. In infants and growing children root replacement should be used to benefit from the valve's growth potential. (Ann Thorac Surg 1991;52: ) n this procedure the patient's own pulmonary valve is I removed together with the main trunk of the pulmonary artery and used to replace the aortic valve. The valve can be inserted in an orthotopic subcoronary position or used as a root replacement with reimplantation of the coronary arteries (Fig 1). The operation was devised and applied in 1967 [l], 5 years after the first homografts [2] and at the time when degenerative changes in homografts were first becoming evident [3]. It seemed clear then that the only prospect of a permanent valve replacement was to use either a living homograft plus immunosuppression or a living autograft having the same anatomical configuration as the aortic valve. An obvious choice was the patient's own pulmonary valve, and there was experimental evidence to support this view [4, 51. This had shown that the autogenous pulmonary valve would function as a mitral or aortic substitute in dogs. An unknown factor was whether the transposed pulmonary valve would support aortic diastolic pressure in humans. This was soon decided clinically, and there has never been an acute or early failure in any valve in more than 350 insertions. This clinical observation has been substantiated by subsequent biomechanical studies (61. The primary indication for the operation is to provide a permanent valve replacement in young patients (approximately 30 years or less) who, with a mechanical valve, would be subject to perhaps 40 years of embolic and hemorrhagic hazard plus continuous cardiac supervision or, in the case of a bioprosthetic valve, the prospect of three to four operations with escalating hazard. More recently an increasingly important indication for the operation has been young infants or children with aortic Excise Pulmonary Valve... Pulmonary Valve To Aorta... Homograft TO Pulmonary Artery... Fig I. Steps in the operation of pulmonary airtogrflft translocation to the aortic area Accepted for publication Aug 9, 1991 Address reprint requests to Mr Ross, 25 Upper Wimpole St, London WlM TA, England by The Society of Thoracic Surgeons /91/$3.50

2 Ann Thorac Surg 1991;52134&50 HOWTODOIT ROSS 1347 Fig 2. The pulmonary artery is divided at the point that has been marked before the start of bypass. valve disease in whom there is not only the prospect of a permanent valve but also one with growth potential [7, 8; Elkins R, personal communication, Principles The first step is to decide whether the case is suitable for an autograft operation. This implies that the pulmonary valve will suit the aortic ring. Because the cardiac output of right and left ventricles is identical, it follows that the size of the right and left outflow orifices should be similar; this is in fact the case in practical terms. Also, the excised pulmonary autograft is very elastic and conforms easily to the new dimensions of the aortic root. If the patient has a dilated or hypoplastic aortic root the autograft can be inserted as a root replacement, but if the pulmonary artery is markedly distended as a result of pulmonary hypertension it may be better to abandon the Fig 4. A curved artery forcep is passed through the pulmonary artery to mark the base of the cusps. An incision is then made in the overlying muscle. operation in favor of a homograft. In any event one is not committed to the operation until the pulmonary valve has been inspected. Technique Subcoronary or Orthotopic Implantation When the chest is opened, the relative size of the pulmonary and aortic roots are appraised and a small scissors \ Fig 3. The divided pulmonary trunk is dissected from above down until right ventricular muscle is exposed. Fig 5. The autograft is excised from the right ventricular outflow. In the region of the first septa1 artery the dissection is obliquely angled away from the artery. Inset shows the dissection angled out in right ventricular muscle.

3 1348 HOW TO DO IT ROSS Ann Thorac Surg 1991;52:134&50 cut is made in the adventitia of the pulmonary artery just below its bifurcation and well above the commissures. This is a guide to the site of subsequent transection before the pulmonary artery collapses and familiar landmarks are lost. It is perfectly satisfactory to establish bypass with a single venous cannula as the tricuspid valve will remain competent, but double cannulation is acceptable. The aorta is opened by an oblique incision into the noncoronary sinus exactly as for homograft replacement, and the aortic valve is inspected and excised. It is usual to introduce flexible, plastic balloon-tipped coronary cannulas at this stage through which blood, and subsequently, cardioplegia solution, can be perfused. Once the surgeon has decided on an autograft, a transverse incision is made in the pulmonary artery at the point selected and the valve is inspected from above to exclude a diseased or bicuspid valve (Fig 2). If the valve is satisfactory, the pulmonary artery is transected just below its bifurcation and dissected from above down with scissors. The plane of the dissection is continued posteriorly keeping close to the pulmonary artery wall until right ventricular muscle is fully exposed (Fig 3). There is often a small area of dense adherence between pulmonary artery and aorta, possibly where the truncus had divided, but most of the dissection is through loose areolar tissue. It is convenient during this phase of the dissection to use conventional coronary perfusion. Because the dissection is relatively bloodless, this will indicate whether the plane of dissection is too close to the left coronary branches. Any small capillary or venous oozing can be gently coagulated during intermittent perfusion of the coronary arteries. By looking down the inside of the transected pulmo- Fig 6. A proxinial running suture takes tension off the subsequent sutures in the region of the first septnl artery. Inset shows superficial bites picking up endocardium and some muscle. J Fig 7. The untailored autograft is fixed in place in the aortic root with multiple interrupted 4-0 sutures. It can then be tailored appropriately or anastomused side-to-side to the coronary arteries. nary artery it is possible to see the sinuses and judge the position of the incision on the right ventricular outflow muscle so as to avoid the cusps. A small stab incision is made at an appropriate level (Fig 4). The muscle incision is then developed across the outflow so as to run about 2 to 3 mm below the base of the sinuses. Over the posterior wall, and particularly toward the left coronary area, the valve is enucleated obliquely with a minimum of muscle from below up to avoid damage to the septal branches of the anterior descending artery [9] (Fig 5). Once the autograft has been removed it is customary to let it lie in the blood within the pericardial cavity or in a blood-filled container. A further perfusion of blood down the left coronary orifice will identify any bleeding points that need attention, after which cardioplegia can be induced. A suitable pulmonary homograft [lo, 111 is chosen, erring preferably in the large size; here size is not particularly important. The pulmonary trunk of the homograft is divided about 1.5 cm above the commissures, and excess muscle is trimmed across the base of the sinuses, leaving more anteriorly to be matched to the ventriculotomy later. The pulmonary homograft should not be too long and is inserted in its normal anatomical position with two sinuses anteriorly and one posteriorly. The distal anastomosis to the pulmonary artery bifurcation is made with a running 4-0 Prolene suture (Ethicon, Somerville, NJ), starting at the midpoint of the carina between the right and left pulmonary arteries. It should be locked at least twice to avoid a pursestringing effect. The anastomosis to the right ventricular muscle starts at the midpoint posteriorly using a running 4-0 Prolene suture. The objective here is to take all tension from the area of the septal artery by carrying this suture toward the operator and taking good, deep, full-thickness bites. It is locked proximally. With the approximating tension taken by this first suture line, the adjacent edges of ventricle and homograft

4 Ann Thorac Surg 1 %1;52: HOWTODOIT ROSS 1349 Fig 8. When the autograft is inserted as a free-standing root the aorta is divided, and the coronary arteries are preserved on buttons or on a tongue of aorta. will lie in close proximity (Fig 6). The suture is then continued in a direction away from the operator, picking up only endocardium and approximately half of the right ventricular wall thickness until the posterior suture line is complete and locked at both ends. The anterior layer is then completed after the homograft muscle is trimmed appropriately, and full thickness bites are again used. Venous pressure is raised just before final closure to expel air from the right ventricle. Attention is then directed to the aorta. The autograft is then trimmed of excess fat, taking care not to buttonhole the thin pulmonary artery wall, and the lower edge of the autograft muscle is trimmed away in a straight line about 1 mm below the lowest point of the cusps. Excess muscle outside the endocardium can be pared away. No attempt is made to sculpt the sinuses, and the pulmonary artery wall is kept intact and held firmly in a clamp during insertion of the autograft. The subsequent steps (Fig 7) are identical with the technique for inserting an aortic homograft [12, 131, but the strength and elasticity of the living autograft tissue make handling and insertion of the sutures much less hazardous than with a friable homograft. Also, because the pulmonary valve is anatomically symmetrical, its placement within the aorta does not have to conform to any anatomical configuration but is oriented at the convenience of the surgeon. Autograft Root Replacement Apart from the theoretical advantages of root replacement [14, 151, which ensures an entirely competent valve and a consequent reduction in turbulence and probable increase in cusp durability, the insertion of the autograft valve in children should probably always be as a root. This allows for growth of the valve ring and cusps without any surrounding tissue restraints. The technique is simpler than conventional subcoronary placement and applies equally to autografts and homografts. Once the autograft has been harvested and the valve removed, the aortic root is exposed more clearly by Fig 9. The lower interrupted sutures can be tied over a thin strip of Teflon or pericardium,q to aid hemostasis.

5 1350 HOWTODOIT ROSS Ann Thorac Surg 19!31; transection of the aorta above the left coronary artery or, as in the Elkins modification, the left coronary orifice is retained on a tongue of aortic tissue (Fig 8). A curved blunt probe is passed down the left coronary artery to determine the lie of the left anterior descending and circumflex branches. The left coronary artery with a button of aorta is well mobilized so as to avoid subsequent tension on it. The right coronary artery is cleared and mobilized also with an adequate button of aortic tissue and retracted with a suture. The aortic root is then cleared in a roughly horizontal manner, leaving a rim of aortic tissue for attachment of the graft or along the top of the subaortic curtain of the mitral cusp and skirting along the upper margin of the membranous septum to avoid conducting tissue. The lower suture line is made with multiple interrupted 4-0 Prolene sutures. These can be conveniently tied over a thin strip of Teflon or autogenous pericardium to ensure hemostasis (Fig 9). However, if growth is an important factor or infection is suspected, the Teflon should be omitted. The coronary arteries are reanastomosed to corresponding holes made on the autograft, the surgeon having noted or marked the position of the commissures to avoid damage to them and the cusps. Where the left coronary artery is retained on a tongue this is incorporated in the upper suture line with running 4-0 Prolene. As an added precaution it is a good policy to complete the left coronary and aortic anastomosis first and temporarily open the aortic clamp. This indicates the most appropriate position for attachment of the right coronary, which may vary from case to case. References 1. Ross DN. Replacement of aortic and mitral valves with a pulmonary autograft. Lancet 1967;2:95M. 2. Ross DN. Homograft replacement of the aortic valve. Lancet 1962;2: Ross DN, Yacoub MH. Homograft replacement of the aortic valve: a critical review. Prog Cardiovasc Dis 1969;11: Lower R, Shafer RC, Shumway NE. Autotransplantation of the pulmonic valve into the aorta. J Thorac Cardiovasc Surg 1960;39: Pillsbury RC, Shumway NE. Replacement of the aortic valve autogenous pulmonic valve. Surg Forum 1966;1717&7. 6. Gorczynski A, Trenker M, Anisiurowicz L, et al. Biornechanics of the pulmonary autograft valve in the aortic position. Thorax 1982;37:53%9. 7. Murata H. A study of autologous pulmonary valve reimplantation [in Japanese]. J Jpn Assoc Thorac Surg 1984;32:14& Gerosa G, McKay R, Ross DN. Replacement of the aortic valve or root with a pulmonary autograft in children. Ann Thorac Surg 1991;51:42&9. 9. Geens M, Gonzales-Lavin L, Dawborn C, Ross DN. The surgical anatomy of the pulmonary artery root in relation to the pulmonary valve autografts and surgery of the right ventricular outflow tract. J Thorac Cardiovasc Surg 1971;62: Kay PH, Livi U, Robles A, Ross DN. Pulmonary homografts. In: Bodnar E, Yacoub M, eds. Biological and prosthetic valves. New York: Yorke Medical Books, 1986:5& Livi U, Abdulla AK, Parker R, Olsen EJ, Ross DN. Viability and morphology of aortic and pulmonary homografts. J Thorac Cardiovasc Surg 1987;93: Ross DN. Technique of aortic valve replacement with a homograft. Ann Thorac Surg 1991;52: Ross DN. Pulmonary valve autotransplantation (the Ross operation). J Cardiac Surg 1988;3(Suppl): Somerville J, Ross DN. Homograft replacement of aortic root with reimplantation of coronary arteries. Br Heart J 1982;47 47? Okita Y, Franciosi G, Matsuki 0, Robles A, Ross DN. Early and late results of aortic root replacement with antibiotic sterilized aortic homograft. J Thorac Cardiovasc Surg 1988; 95:69&704.