Management of Fusiform Ascending Aortic Aneurysms

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1 Management of Fusiform Ascending Aortic Aneurysms Stuart Houser, M.D., Jose Mijangos, M.D., Amarenda Sengupta, M.D., Lawrence Zaroff, M.D., Robert Weiner, M.D., and James A. DeWeese, M.D. ABSTRACT Thirteen patients had elective surgical treatment of fusiform ascending aortic aneurysms at Strong Memorial and Rochester General Hospitals from 1970 to There were 8 men and 5 women ranging in age from 51 to 78 years (mean, 61 years). Nine patients underwent composite tube graft and aortic valve replacement, 3 had aortic valve replacement plus supracoronary tube grafts, and 1 had aortic valve replacement plus aneurysmorrhaphy. Coronary reimplantation alone or combined with saphenous vein bypasses was fashioned in 10 patients. Potassium cardioplegia was considered a useful adjunct in 6 patients. Two early deaths accounted for an operative mortality of 15.4%. There were 3 late deaths. Eight patients are alive and well 2 to 109 months after operation. The management of fusiform ascending aortic aneurysms requires surgical repair to prevent aortic rupture or dissection, left ventricular failure secondary to aortic insufficiency, and displacement of vital structures [91. This technically demanding operation has in the past decade been facilitated by the use of composite tube graft and aortic valve prostheses, by highly developed methods of coronary artery reconstruction, and by a strict attention to techniques of myocardial preservation. This review stresses the importance of these technical aspects in a series of patients undergoing elective repair of ascending aortic aneurysm. Material and Methods Thirteen patients with fusiform, nondissecting ascending aortic aneurysms underwent surgical treatment at Strong Memorial Hospital and From the University of Rochester Medical Center, Division of Cardiothoracic Surgery, Rochester, NY. Accepted for publication Jan 30, Address reprint requests to Dr. DeWeese, Division of Cardiothoracic Surgery, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY Rochester General Hospital between 1970 and The 8 men and 5 women ranged in age from 51 to 78 years (mean, 61 years). Preoperative clinical findings were as follows: precordial murmurs of aortic insufficiency, all patients; a history of congestive heart failure, 9; chest pain, 8, but only 5 had pain typical of angina pectoris; musculoskeletal stigmata of Marfan s syndrome, 2; and hypertension, 2. Admission chest roentgenograms of these individuals revealed one or more characteristic findings (Fig 1). The degree of cardiomegaly ranged from borderline to marked. Right hilar prominence of the aortic silhouette was noted in most of the patients. A few roentgenograms demonstrated congestive heart failure. Preoperative angiograms defined the fusiform aneurysms accompanied by marked aortic regurgitation in all patients (Fig 2). However, selective coronary arteriography was completed in only 1 of the 5 patients with angina. Of the 3 patients with nonanginal chest pain, 2 had incomplete coronary arteriograms and 1 had no coronary study. The patients were divided into four surgical groups. Seven patients (Group 1) received composite tube graft and aortic valve prostheses plus reimplantation of coronary ostia into side holes made in the tube grafts. Two patients (Group 2) received composite grafts and a combination of coronary ostium reimplantation plus aortocoronary artery bypass with reversed saphenous vein. Three patients (Group 3) underwent aortic valve replacement plus insertion of a supracoronary tube graft to reconstruct the ascending aorta. Group 4 includes 1 patient who had an aortic valve replacement plus aneurysmorraphy and double aortocoronary artery bypass. Cardiopulmonary bypass was established in all patients by cannulas in the femoral artery and right atrium. The left ventricle was decompressed through the apex or right superior by The Society of Thoracic Surgeons

2 71 Houser et al: Fusiform Ascending Aortic Aneurysms Fig 2. Posteroanterior thoracic aortogram showing marked pear-shaped dilatation of the ascending aorta. Fig 1. Posteroanterior chest roentgenogram showing prominent ascending aorta and cardiomegaly. Myocardial Preservation Techniques Potassium Variables Systemic Cooling Coronary Perfusion Cardioplegia No. of patients Dates of operation 2/70-11/78 2/70-4/77 8/76-11/78 Group Group Group Group Core temperature ("C) (mean, 25.7) (mean, 26.6) (mean, 25) Myocardial temperature ("C)... Not measured Less than 20 Aortic clamp time (min) (mean, 125.5) (mean, 105.5) Myocardial infarction Operative deaths Late deaths pulmonary vein. All patients were cooled systemically to 20" to 30 C (mean, 25.7"C). Seven patients had direct coronary artery perfusion, and 6 had cold potassium cardioplegia (Table). In 2 patients in the latter group, myocardial temperatures were measured and were below 20 C while the aortas were clamped. The accumulated aortic cross-clamp times are summarized in the Table. Twelve woven tube grafts were 25 to 35 mm in diameter. Six Starr-Edwards (sizes 9 to 12) and seven Lillehei-Kaster (sizes 16 to 25) valve prostheses were used; both types were incorporated in the composite grafts. The aneurysm wall was fashioned around the tube grafts in 8 patients, resected in 4, and imbricated for definitive repair in 1. Figure 3 illustrates the insertion of the com-

3 72 The Annals of Thoracic Surgery Vol30 No 1 July 1980 Fig 3. Insertion of the composite graft. Anastomosis of the Dacron tube to the coronary ostia with a running suture. The technique is begun after the prosthesis is sewn to the aortic annulus. 1 posite graft in Group 1. After the graft is sewn to the aortic annulus, the upwardly displaced coronary ostia are reimplanted into side holes in the Dacron tube, using a running 4-0 Prolene suture technique. The distal graft-aorta anastomosis can then be started inside the aorta to allow subsequent wraparound of the aneurysm wall to aid hemostasis. In 1 patient in Group 2, the right coronary ostium was mobilized with a cuff of aorta and then reimplanted into the Dacron tube (Fig 4). The saphenous vein graft in this patient was brought off the aorta above the tube graft to minimize bleeding in the suture line. Figures 5 and 6 illustrate the techniques used in Groups 3 and 4, respectively. In Group 3, Teflon strips were used, as popularized by Anagnostopoulos [l], to reinforce both the proximal and distal anastomoses between aorta and tube graft. Likewise in Group 4, Teflon strips reinforced the aortic closure. It is notable that the integrity of the aortic wall in the patient in Group 4 was sufficient not only to allow safe aneurysmorraphy but also to support aortocoronary bypass of the triple-vessel disease. Fig 4. Anastornosis of the right coronary artery with a cuff of aorta to the Dacron tube. The vein graft is sewn to the aorta distal to the Dacron tube. Pa thology Excised valve cusps were grossly deformed and had irregular, thickened areas. Nine of twelve valves examined histologically showed myxomatous changes. Six of eight specimens of aorta showed microscopic changes ranging from medial mucoid degeneration to cystic medial necrosis. Results Complications Two patients required early reexploration for suture line bleeding. In 1 of them the bleeding was not controlled, and the patient died. Two patients sustained perioperative myocardial infarctions. One survived, and the other died of low cardiac output failure after a prolonged period. The operative mortality was 15.4%. One patient had early malfunction of the

4 73 Houser et al: Fusiform Ascending Aortic Aneurysms Fig 5. Supracoronary tube graft in Group 3 patients. Note the use of Teflon strips to reinforce the aortic suture lines. Fig 6. Use of Teflon strips to reinforce the closure of the aneurysmorrhaphy. valve prosthesis, necessitating reoperation and rotation of the disc. Atrial fibrillation developed in 3 patients, and another had a transient heart block postoperatively. In 1 patient, respiratory insufficiency necessitated prolonged ventilator support. Another patient had mild leg ischemia related to femoral artery cannulation; no treatment was required. Follow- UP Figure 7 depicts the follow-up of these patients. Three died of unknown causes 12, 21, and 31 months postoperatively. Therefore, 8 patients were alive and well from 2 to 109 months after operation. All 4 surgical groups are represented in these 8 survivors. In 2 patients in Group 1, postoperative angiograms were made. One study showed good function of the composite graft. The left coronary artery was visualized, but the right was not. This patient died 21 months postoperatively. The second study also showed proper MONTHS Fig 7. Patient follow-up: 8 patients are alive and doing well 2 to 109 months postoperatively.

5 74 The Annals of Thoracic Surgery Vol30 No 1 July 1980 composite graft function and visualization of both coronary arteries. This patient is doing well one year after operation. Neither angiogram revealed an anastornotic or perivalvular leak. Comments The low incidence of hypertension in these 13 patients is interesting. Up to 87% of patients with acute aortic dissections are hypertensive [12]. However, like those with aortic dissections, our patients had myxomatous valve degeneration and idiopathic aortic medionecrosis, as described by Davies [6]. Most of them seem to fit the so-called forme fruste pattern of Marfan's syndrome [Sl. Evaluation of patients with fusiform ascending aortic aneurysms should include selective coronary angiography. However, massive dilatation of the aortic root with displacement of coronary ostia often makes this study difficult to complete. The use of a composite graft to repair an ascending aortic aneurysm was applied by Bentall and DeBono [31 in Edwards and Kerr 171 proposed wrapping the aneurysm wall around the tube to facilitate hemostasis. The present series substantiates the applicability of these techniques, as do other recent reports 14, 10, 111. However, the value of flexibility on the part of the surgeon and the ability to fashion the operation to the patient are also emphasized. The appropriate operation for these patients requires careful evaluation at operation of the extent of aneurysmal dilatation, displacement of coronary ostia, and, to a lesser extent, the gross integrity of the aortic wall. Furthermore, current techniques of coronary artery revascularization offer the surgeon useful alternatives for reconstituting coronary flow with repair of these aneurysms. In the past two years, groups in Minneapolis, Pittsburgh, and London have advocated the use of cold cardioplegia for myocardial preservation during these operations [2,4,101. In the current series there were no operative deaths or major complications in the cardioplegia group (see Table). One death secondary to myocardial infarction resulted from a left main coronary dissection caused by manipulation of the perfu- sion cannula. We believe that utilization of cold potassium cardioplegia can facilitate effective myocardial preservation in these patients during the aortic cross-clamp period. Infusion of the solution can be intermittent as needed to keep the myocardial temperature below 20 C and thus preclude the frustration of keeping coronary perfusion catheters in place. As others [8, 101 also have pointed out, composite graft placement can be done with an acceptable mortality. However, more data are needed to predict the outcome of these patients beyond two to three years. Mayer and his group [lo] stress the importance of postoperative angiograms. Because of the diffuse nature of the degenerative collagen disorder in these patients, the late occurrence of pseudoaneurysms and paravalvular leaks is not surprising. Two of our late deaths occurred after composite graft placement. The early postoperative angiogram in 1 of these patients did not show visualization of the right coronary artery, but the death at 31 months was unexplained. The other patient died 12 months postoperatively, also of unknown cause. We agree that close follow-up with periodic angiograms in this patient population is necessary. References Anagnostopoulos CE: Acute Aortic Dissections. Baltimore, University Park Press, 1975, p 160 Bentall HH: Discussion of Mayer et a1 [lo] Bentall H, DeBono A: A technique for complete replacement of the ascending aorta. Thorax 23:338, 1968 Campbell CD, Hardesty RL, Siewers RD, et al: Selected therapy for ascending aortic aneurysms. Arch Surg 113:1324, 1978 Chapman DW, Beazley HL, Peterson PK, et al: Annulo-aortic ectasia with cystic medial necrosis. Am J Cardiol 16:679, 1965 Davies DH: Idiopathic cystic medial necrosis of the aorta. Br Heart J 3:166, 1941 Edwards SW, Kerr AR: A safer technique for replacement of the entire ascending aorta and aortic valve. J Thorac Cardiovasc Surg , 1970 Kouchoukos NT, Karp RB, Lell WA: Replacement of the ascending aorta and aortic valve with a composite graft: results in 25 patients. Ann Thorac Surg 24:140, 1977 Liddicoat JE, Bekassy SM, Rubio PA, et al: Ascending aortic aneurysms. Circulation 52:Suppl 2:202, 1975

6 75 Houser et al: Fusiform Ascending Aortic Aneurysms 10. Mayer JE Jr, Lindsay WG, Wang V, et al: Composite replacement of the aortic valve and ascending aorta. J Thorac Cardiovasc Surg 76:816, Semb BKH, Froysaker T, Hall KV: Complete replacement of the ascending aorta and the aortic valve with coronary reimplantation. J Cardiovasc Surg (Torino) 2035, Wheat MW Jr, Harris PD, Malm JR, et al: Acute dissecting aneurysms of the aorta. J Thorac Cardiovasc Surg 58:344, 1969