and Discrete Ascending Aortic Aneurysm

Transcription

1 ST cal Repair of Dissection of e Upper Descending Thoracic Aorta and Discrete Ascending Aortic Aneurysm Grant V. S. Parr, M.D., and Nicholas T. Kouchoukos, M.D. ABSTRACT This report describes successful staged surgical repair in 2 patients with dissection of the upper descending thoracic aorta (DeBakey type 111) with coexisting discrete Marfan s aneurysms of the ascending aorta. Initial repair of the descending aortic dissection was done through a left thoracotomy using a transverse aorta-femoral artery shunt in 1 patient and a left ventricular apex-femoral artery shunt without systemic heparinizaiion in the other. Emphasis is placed on the need for pharmacological reduction of blood pressure during aortic crossclamping as well as the use of a shunt to prevent dissection of the ascending aortic aneurysm. In both patients, subsequent repair of the ascending aortic aneurysm was accomplished using composite graft replacement of the aortic valve and ascending aorta. This operation is advised for such patients even in the absence of notable aortic valve incompetence. The decreased life expectancy of patients with Marfan s disease has been well documented [271. Death is most commonly caused by aortic valve incompetence, aortic dissection, or aneurysmal rupture [l, 2, 5, 12, 13, 26, 27,361. When associated with Marfan s disease, aortic dissection usually occurs at the site of an ascending aortic aneurysm [l, 2, 12, 13, 16, 291. Surgical treatment using cardiopulmonary bypass is advised for ascending aortic dissections (DeBakey type I or 11; Anagnostopolous type A) or aneurysms [l, 2,7,8, 14,20,22,24,28,30,31,33,35, 371. There is considerable controversy over the From the Department of Surgery, College of Medicine, The Milton S. Hershey Medical Center of The Pennsylvania State University, Hershey, PA, and the Division of Cardiovascular Surgery, Department of Surgery, University of Alabama Hospitals, Birmingham, AL. Presented at the Fifteenth Annual Meeting of The Society of Thoracic Surgeons, Jan 15-17, 1979, Phoenix, AZ. Address reprint requests to Dr. Parr, Department of Surgery, The Milton S. Hershey Medical Center of The Pennsylvania State University, 500 University Dr, Hershey, PA use of pharmacological versus surgical treatment of dissections of the upper descending thoracic aorta (DeBakey type 111, Anagnostopolous type B) [l-3, 7-9,17,18,21,25,33,35,371. Two patients, each with a coexisting dissection of the upper descending thoracic aorta and a Marfan s aneurysm of the ascending aorta, are described. Each presented a dilemma as to appropriate treatment. Pharmacological treatment may not be as effective for Marfan s disease as it is for dissections due to hypertensive disease alone. Primary repair of the distal dissection can give rise to dissection of the ascending aortic aneurysm during cross-clamping, and thus makes special precautions necessary. Conversely, the presence of an acute distal dissection makes primary repair of the ascending aneurysm hazardous because of the need for systemic heparinization. Treatment in these 2 patients was, in part, dictated by their clinical course; however, this brief experience permits a basis for future management. Furthermore, the present commercially available shunts and composite grafts, as well as present operative and anesthetic techniques, make staged surgical therapy feasible. Patient 1 A 37-year-old man with known Marfan s disease was admitted to the University of Alabama Hospitals on September 16, 1974, two weeks after an episode of sharp, tearing back pain. A murmur of aortic incompetence was noted, and aortography showed an aneurysm of the ascending aorta and a dissection of the upper descending thoracic aorta with a tear just distal to the origin of the left subclavian artery (Fig 1). Elective surgical repair of the descending aortic dissection was undertaken. A standard posterolateral left thoracotomy was made through the bed of the unresected fifth rib, and the left common femoral artery was isolated. A shunt was constructed of 3/s inch (9.5 mm) by Grant V. S. Parr

2 152 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 Fig 1. (Patient 1 J lnitial aortogram of the dissection of the upper descending thoracic aorta. The fusiform aneurysm of the ascending aorta is not well outlined in this view. Fig 2. (Patient 1.) Aortogram made nine days after repair of the descending aortic dissection. Note the localized dissection in the ascending aorta. Although aortic regurgitation is present, the left ventricle is not visualized here. Silastic tubing and two metal perfusion can- (Fig 2). Because the patient was clinically satisnulae [181. After the intravenous administra- factory, he was discharged fourteen days after tion of 2,500 U of heparin, the shunt was in- operation. serted through a pursestring suture in the The patient was readmitted 12 weeks later. transverse aortic arch and into the left common Resection of the ascending aorta and aortic femoral artery. Trimethaphan camsylate (Ar- valve replacement was performed on January fonad) was administered to keep the systolic 24, 1975, through a median sternotomy incision blood pressure between 120 and 130 mm Hg. with cannulation of the right common femoral The aorta was cross-clamped for 45 minutes artery, as previously described [ZO]. Carbetween the left common carotid and left sub- diopulmonary bypass, at 30T, was established clavian arteries as well as above the diaphragm. for 105 minutes, and a vent was advanced into The systolic blood pressure rose transiently to the left ventricle through a pursestring suture in 150 mm Hg but was lowered with an increased the right superior pulmonary vein. The aorta infusion of trimethaphan. An 18 mm knitted was cross-clamped, a longitudinal aortotomy Dacron tube graft was sutured into the aorta was made, and coronary perfusion was estabbelow the left subclavian artery with a running lished. Sinus rhythm was maintained. The aorsuture of 4-0 Prolene and a buttressing strip of tic leaflets were excised and a composite graft, Teflon felt. The distal anastomosis was com- which had been constructed earlier of a No. 11A pleted in a similar manner with Teflon felt and Starr-Edwards model 1260 prosthesis and a 30 obliterated the false lumen. After removal of mm woven Dacron tube, was utilized. The aoroccluding clamps, the shunt was clamped and tic annulus was anastomosed to the prosthesis removed. The thoracotomy was closed and the using 2-0 Ticron in a double-armed fashion, femoral artery repaired in a standard fashion. with pledgets of Teflon on the aortic side. But- After operation, the aortic diastolic murmur tons of the Dacron graft were excised for the was noted to have increased in intensity. Aor- right and left coronary ostia and the coronary tography on the ninth postoperative day perfusion cannulae were replaced from within showed a localized (DeBakey type 11) dissection the graft. An anastomosis was constructed beof the ascending aorta and aortic incompetence tween each coronary ostium and the graft using

3 153 Parr and Kouchoukos: Dissection of Upper Descending Thoracic Aorta Fig 4. (Patient 2.) Initial aortogram. The black dots outline the aneurysm of the ascending aorta. The aortic arch appears normal, with a large dissection of the upper descending thoracic aorta. Fig 3. (Patient 1.) Aortogram made after composite graft replacement of the aortic valve and the ascending aorta. Note the patent left coronary ostium. The right coronary ostium, not well seen here, is also patent. continuous suture of 5-0 Prolene. The distal anastomosis was made to the aorta using a running suture of 4-0 Prolene. Then the coronary perfusion cannulae were removed, and air was evacuated just before completion of this anastomosis. The aneurysm then was closed over the graft and cardiopulmonary bypass was discontinued. Subsequent aortography (Fig 3) revealed the intact repair, although a double lumen was present distal to the Dacron graft in the descending aorta. The patient remains well 4 years after his second operation. Patient 2 A 22-year-old man with the clinical stigmata of Marfan s disease had severe, tearing back pain in November, He was seen in an emergency ward and found to be hypertensive, but he was released. He did well until February 12, 1978, when he again had severe back pain. Chest roentgenograms at another hospital showed a widened mediastinum, and the clini- cal diagnosis of an aortic dissection was made. He was transferred to the Milton S. Hershey Medical Center. On examination, he was hypertensive, with a blood pressure of mm Hg in both arms. Carotid, femoral, and distal arterial pulses were intact. There were no cardiac murmurs. Emergency aortography showed a dissection of the upper descending thoracic aorta and an ascending aortic aneurysm of the Marfan s type (Fig 4). A right radial artery cannula was placed, and antihypertensive therapy was instituted with propranolol, reserpine, and nitroprusside. In spite of good control of blood pressure, a chest roentgenogram made 36 hours later showed additional widening of the upper descending thoracic aorta and subpleural thickening consistent with a leaking dissection [lo]. Emergency operation was undertaken. A triple-lumen Swan-Ganz catheter was placed before general orotracheal anesthesia was induced. A standard left posterolateral thoracotomy was made through the bed of the nonresected fifth rib, and the left common femoral artery was exposed. Because of the large mediastinal hematoma, the transverse aortic arch was not cannulated. Rather, a com-

4 154 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 mercially available 9 mm Gott shunt was placed through pursestring sutures into the left ventricular apex and the left femoral artery. The aorta was cross-clamped between the left common carotid and left subclavian arteries, as well as just above the diaphragm, for 50 minutes. Prior to cross-clamping, infusion of sodium nitroprusside was increased to lower systolic blood pressure to 80 mm Hg. When the aorta was cross-clamped, the systolic pressure rose to 100 mm Hg and was maintained at that level. A 26 mm low-porosity woven Dacron tube graft, about 14 cm long, was sutured in place just below the left subclavian artery end-to-end, using a running suture of 3-0 Prolene. The distal anastomosis was constructed in the middle of the descending thoracic aorta, thereby closing the false lumen between the graft and a Teflon felt strip. Postoperatively, an episode of hypotension and a high central venous pressure, equal to pulmonary capillary wedge pressure, prompted a reexploration for possible pericardial tamponade; however, none was found. A superficial wound infection delayed discharge until 4 weeks after operation, but convalescence was otherwise uneventful. The patient was readmitted six months later. No cardiac murmurs were heard. A repeat aortogram (Fig 5) showed excellent repair of the dissection without stenosis or distal dissection, although the graft was minimally redundant. The ascending aorta had a large aneurysm, but no aortic valve incompetence. Nevertheless, we elected to replace the aortic valve as well as the ascending aorta because of the known incidence of subsequent aneurysms of the sinuses of Valsalva and aortic valve incompetence in patients with Marfan's syndrome in whom only a supracoronary repair is done [20, 24, 321. On August 2, 1978, an operation was performed through a median sternotomy with retrograde aortic perfusion through the right common femoral artery. Cardiopulmonary bypass was established for 117 minutes. A vent was advanced into the left ventricle through a pursestring suture in the left atrium at the confluence of the right pulmonary veins. The heart was profoundly cooled by the perfusate, and when the ventricle fibrillated, the aorta was immediately cross-clamped. Initially, we at- Fig 5. (Patient 2.) Aortogram made after repair of the dissection of the upper descending thoracic aorta. An aneurysm, typical of Marfan's disease, is seen in the ascending aorta. Aortic valve incompetence is not identified. Some redundancy is present in the Dacron graft. tempted to administer cold potassium cardioplegic solution [231 through a pursestring suture in the ascending aorta, but because of aortic incompetence then evident, this was not possible. A longitudinal aortotomy was made, and 1,300 ml of 5 C cardioplegic solution was infused by cannulation of the left and right coronary ostia until the temperature of the ventricular septum reached 10 C. External cardiac cooling was also employed by irrigating the pericardial sac with 5 C lactated Ringer's solution. The aortic leaflets were excised. Subsequent pathological examination showed myxoid degeneration of the aortic valve and a paucity of elastic fibers. The aortic aneurysm had almost no elastic fibers. A commercially prepared composite graft, consisting of a 25 mm Bjork- Shiley valve in a 28 mm woven Dacron prosthesis, was chosen and preclotted with 50 ml of heparinized blood from the venous return line plus three vials of topical thrombin [201. The valve was sutured in place using double-armed sutures of 2-0 Ethibond with pledgets of Teflon felt. When the myocardial temperature reached 17"C, 800 ml of additional cardioplegic solution was reinfused to again bring myocardial temperature to 10 C. Buttons of the Dacron graft

5 155 Pam and Kouchoukos: Dissection of Upper Descending Thoracic Aorta were excised and anastomoses were made between the coronary ostia and the graft using running sutures of 4-0 Prolene, as previously described [20]. The distal anastomosis was then made using a running suture of 3-0 Prolene. Air was evacuated from the graft and the left ventricle as the heart was defibrillated. After rewarming, cardiopulmonary bypass was discontinued. However, an episode of elevated left atrial pressure and hypotension indicated compression of the graft [19] due to blood leaking between external aorta and graft. Cardiopulmonary bypass was reestablished, hemostasis was obtained, and the graft again was wrapped by the aneurysm. The patient s postoperative course was unremarkable, and he was discharged on the eighth postoperative day. He remains well. Comment We have reviewed numerous large series of patients with thoracic aortic aneurysms and dissections [l-8,12-17,20,24-31, and have failed to identify any patients similar to those discussed here. Our experience with these patients provides a reasonable plan for management. After the diagnosis is confirmed by aortography [5], initial treatment of hypertension, as recommended by Wheat and co-workers [35-371, is appropriate. However, in Marfan s disease, there is a tendency toward enlargement of the ascending aortic aneurysm [26, 271. Aortic valve incompetence, aortic dissection, or aortic rupture decrease life expectancy [27]. Furthermore, as in Patient 2, antihypertensive therapy alone can prove to be inadequate, especially in patients with Marfan s disease. Therefore, it would appear that definitive therapy involves surgical intervention. We recommend that surgical intervention be undertaken at the earliest possible time that a complete cardiovascular surgical team, including surgeon, cardiovascular anesthesiologist, scrub nurse, and perfusionist, can be assembled. Careful hemodynamic monitoring, including right radial artery and pulmonary artery catheters, is mandatory. The use of a shunt obviates the need for systemic heparinization [9,21,34]. Cannulation of the transverse aorta is preferable, as it avoids later pericardial adhesions, but may be impossible when the mediastinal hematoma is large. Left ventricular apex-femoral artery shunting appears adequate in preventing renal failure and spinal cord injury. Furthermore, the use of a shunt decreases pressure in the proximal aorta. Additional pharmacological reduction of blood pressure during aortic crossclamping may be necessary to avoid proximal dissection, as might have occurred in Patient 1. Control of systolic blood pressure to the range of 100 mm Hg, in combination with a shunt, may have prevented a proximal dissection in Patient 2. Partial femoral bypass is not recommended because of the need for heparinization and subsequent difficulties with bleeding. We agree with Mayer and colleagues [241 that aortic valve replacement is indicated in patients with Marfan s disease and aneurysms of the ascending aorta, even in the absence of marked aortic valve incompetence. As reported by Symbas and colleagues [321 and as experienced by one of us (N. T. K.) [201, supracoronary repair alone can be followed by development of massive aneurysms of the sinuses of Valsalva. Composite graft replacement of the aortic valve and the ascending aorta has proved acceptable in numerous series [6, 11, 15, 24, 28, 30, 351. Although a ball valve was used in the composite graft in Patient 1, the now commercially available combination of a tilting-disc valve in a Dacron tube graft appears ideal, and we prefer to use it in patients with Marfan s disease and aneurysms of the ascending aorta. References 1. Anagnostopolous CE: Acute Aortic Dissections. Baltimore, University Park Press, Appelbaum A, Karp RB, Kirklin JW: Ascending vs descending aortic dissections. Ann Surg 183:296, Austen WG, Buckley MJ, McFarland J, et al: Therapy of dissecting aneurysms. Arch Surg 95:835, Baer RW, Taussig HB, Oppenheimer EH: Congenital aneurysmal dilatation of the aorta associated with arachnodactyly. Bull Johns Hopkins Hosp 72:309, Barrett JS-, Helwig J Jr, Kay CF, et al: Cineaortographic evaluation of aortic insufficiency: unsuspected idiopathic aneurysmal dilatation of

6 156 The Annals of Thoracic Surgery Vol 28 No 2 August 1979 the aortic root as a possible indication of the Marfan syndrome. Ann Intern Med 61:1071, Bentall HH, DeBono A: A technique for complete replacement of the ascending aorta. Thorax 23:338, Daily PO, Trueblood HW, Stinson EB, et al: Management of acute aortic dissections. Ann Thorac Surg 10:237, DeBakey ME, Henly WS, Cooley DA, et al: Surgical management of dissecting aneurysms of the aorta. J Thorac Cardiovasc Surg 49:130, Donahoo JS, Brawley RK, Gott VL: The heparincoated vascular shunt for thoracic aortic and great vessel procedures: a ten-year experience. Ann Thorac Surg 23:507, Dotter CT, Niles NR, Steinberg I: Impending aortic rupture: pathogenesis of x-ray signs. N Engl J Med 265:214, Edwards WS, Kerr AR: A safer technique for replacement of the entire ascending aorta and aortic valve. J Thorac Cardiovasc Surg , Gore I: Dissecting aneurysms of the aorta in persons under forty years of age. AMA Arch Pathol 55:1, Gore I, Seiwert VJ: Dissecting aneurysm of the aorta: pathologic aspects: an analysis of eightyfive fatal cases. AMA Arch Pathol53:121, Groves LK, Effler DB, Hawk WA, et al: Aortic insufficiency secondary to aneurysmal changes in the ascending aorta: surgical management. J Thorac Cardiovasc Surg 48:362, Helseth HK, Haglin JJ, Stenlund RR, et al: Evaluation of composite graft replacement of the aortic root and ascending aorta. Ann Thorac Surg 18:138, Hirst AE Jr, Johns VJ Jr, Kime SW Jr: Dissecting aneurysm of the aorta: a review of 505 cases. Medicine 37:217, Hume DM, Porter RR: Acute dissecting aortic aneurysms. Surgery 53:122, Kahn DR, Vathayanon S, Sloan H: Resection of descending thoracic aneurysms without left heart bypass. Arch Surg 97:336, Klopp E, Hauer J, Zinner M, et al: Acute supravalvular stenosis following replacement of the aortic valve and ascending aorta in a patient with Marfan s syndrome: report of a case. Surgery 84:292, 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, Krause AH, Ferguson TB, Weldon CS: Thoracic aneurysmectomy utilizing the TDMAC-heparin shunt. Ann Thorac Surg 14:123, Liotta D, Hallman GL, Milam JD, et al: Surgical treatment of acute dissecting aneurysm of the ascending aorta. Ann Thorac Surg 12:582, Manley NJ, Williams DR, Kurusz M, et al: Perfusion technique for induced cardioplegia. Proc AmSECT 1231, Mayer JE Jr, Lindsay WG, Wang Y, et al: Composite replacement of the aortic valve and ascending aorta. J Thorac Cardiovasc Surg 76:816, McFarland J, Willerson JT, Dinsmore RE, et al: The medical treatment of dissecting aortic aneurysms. N Engl J Med 286:115, McKusick VA: The cardiovascular aspects of Marfan s syndrome: a heritable disorder of connective tissue. Circulation 11:321, Murdoch JL, Walker BA, Halpern BL, et al: Life expectancy and causes of death in the Marfan syndrome. N Engl J Med 286:804, Najafi H: Aneurysm of cystic medionecrotic aortic root: a modified surgical approach. J Thorac Cardiovasc Surg 66:71, Shennan T: Dissecting aneurysms. Medical Research Council (Great Britain) Special Report Series 193:138, Singh MP, Bentall HH: Complete replacement of the ascending aorta and the aortic valve for the treatment of aortic aneurysm. J Thorac Cardiovasc Surg 63:218, Sorensen HR, Olsen H: Ruptured and dissecting aneurysms of the aorta: incidence and prospects of surgery. Acta Chir Scand 128:644, Symbas PN, Raizner AE, Tyras DH, et al: Aneurysms of all sinuses of Valsalva in patients with Marfan s syndrome: an unusual late complication following replacement of aortic valve and ascending aorta for aortic regurgitation and fusiform aneurysm of ascending aorta. Ann Surg 174:902, Thomas CS Jr, Alford WC Jr, Burrus GR, et al: The effectiveness of surgical treatment of acute aortic dissection. Ann Thorac Surg 26:42, Valiathan MS, Weldon CS, Bender HW Jr, et al: Resection of aneurysms of the descending thoracic aorta using a GBH-coated shunt bypass. J Surg Res 8:197, Wheat MW Jr, Boruchow IB, Ramset HW: Surgical treatment of aneurysms of the aortic root. Ann Thorac Surg 12:593, Wheat MW Jr, Palmer RF: Dissecting aneurysms of the aorta. Curr Probl Surg: July, Wheat MW Jr, Palmer RF, Bartley TD, et al: Treatment of dissecting aneurysms of the aorta without surgery. J Thorac Cardiovasc Surg 50: 364, 1965 Discussion DR. LEIGH I. G. IVERSON (Oakland, CA): I also believe shunting to the aorta distal to the cross-clamp is an excellent idea. At my institution, we favor femoral-

7 157 Parr and Kouchoukos: Dissection of Upper Descending Thoracic Aorta femoral bypass utilizing the heparin-bonded tubing and a roller pump. The venous cannula is placed in the region of the right atrium. Because this allows US to control preload to the heart, pharmacological control of hypertension in the brachiocephalic vessels usually is not necessary. Patients are ventilated with 100% oxygen, which maintains adequate oxygen levels in the periphery. Serial enzymes have been measured in several patients. We have not been able to detect any notable problems from perfusing with mixed venous blood. Using this technique, we have operated on 25 patients. Of these patients, 92% survived. The 2 deaths were unrelated to the shunting technique. There are many advantages to both the technique described by Dr. Parr and our method. Hypoxia and tissue ischemia with their attendant spinal cord and visceral organ dysfunctions are avoided. Without systemic heparinization, bleeding is kept to a minimum. The shunt allows the operation to be conducted without racing against the clock and consequently with greater accuracy. I would like to ask the authors if they find the presence of the tubing in the operative field to be cumbersome, and if some of their problems are related, perhaps, to the cannulation of the transverse arch as well as the heart. I also wonder if they plan to use the shunting technique, in future, for procedures on the descending aorta. DR. HOVALD K. HELSETH (Minneapolis, MN): I enjoyed Dr. Parr s presentation of a very difficult problem partly because at the University of Alabama Hospitals there has been very consistent support of a complete resection of the aortic root and the use of a composite graft. We have seen 1 similar patient, a 40-year-old man with Marfan s syndrome. Initially he was seen because of congestive heart failure. He also had a total descending dissection, which was estimated to be about eighteen months old. We elected to do the composite graft first. In three months we operated on the descending aorta, with left heart bypass. The patient has done well. We have had occasion to use the composite graft in 35 patients during the past 7 years. There are 34 long-term survivors, including 10 with acute ascending aortic dissections. If a surgeon is inclined to use the composite graft technique, the graft can be made up quickly in the operating room. However, I think, based on our experience with the most recent 5 patients seen, that time and blood loss can be saved if the manufactured composite graft, which has a soft sewing ring, is used. It puts the valve in a subannular position, and puts the coronary ostia somewhat more adjacent to the tube. Because I think this is going to be more of a problem in the future, I would like to ask Dr. Parr what his department would do with a true Marfan patient 10- to 15-years-old, who has mild dilatation of the ascending aorta and probably some very mild aortic incompetence, and whose father died at the age of 28 years of an acute dissected ascending aorta. DR. PARR: I would like to thank the discussants for their comments. Dr. Iverson, indeed the transverse aortic arch can be difficult if there is massive mediastinal hematoma, as in the second patient, and I find the left ventricular apex-femoral artery shunt to be totally satisfactory and not at all in the way. I appreciate your comments on using a roller pump, and I think this is an excellent idea. I would like to note, however, that data now available suggest that using a shunt from the ascending aorta provides greater afterload reduction, both in lowering of arterial pressure and left atrial or pulmonary capillary wedge pressure. As to the second question, what I would do with a 15-year-old child, Dr. Helseth, I would put him on a regimen of negative inotropic, antihypertensive agents and follow the aortic root very closely with echocardiograms, perhaps as often as every four months. If the aneurysm was small, I think I might defer operation until a full-sized valve could be placed using the technique we have shown. A normal aorta has elastin throughout the media. In patients with Marfan s syndrome, however, there is absolutely no elastin in the aorta, and I think that a surgeon has to be ready to replace the aorta in these patients at an early time. The aortic valve itself has no elastin in these patients, and thus should also be replaced.