S and aortic arch is associated with high morbidity and

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1 Sutureless Ring Graft Replacement of Ascending Aorta and Aortic Arch Mehmet C. Oz, MD, Robert C. Ashton, Jr, Kathleen W. McNicholas, MD, and Gerald M. Lemole, MD Department of Surgery, The Medical Center of Delaware, Wilmington, Delaware, and Department of Surgery, Columbia- Presbyterian Medical Center, New York, New York Complications after aortic replacement that result from prolonged graft insertion time and technical difficulties with suturing through friable, diseased aortic tissue can be addressed with use of the sutureless intraluminal ring graft. Between 1978 and 1989, we replaced the ascending aorta or aortic arch with this device in 49 patients. At no time were we unable to use a sutureless graft during a procedure. Twenty-eight cases of aneurysmal disease and 21 cases of acute or chronic dissection were treated. Twenty-six patients required replacement of the aortic valve, with annuloaortic ectasia being the most common indication (71%). Ten patients underwent concomitant coronary artery bypass grafting. The operative mortality rate for ascending aortic aneurysm repairs was 4%, and that for dissections was 18%. Five of 8 patients requiring aortic arch replacement survived. Most patients were studied angiographically before discharge. No complications were related to anastomotic hemorrhage, pseudoaneurysm formation, graft migration, or thromboemboli. Individual cases of phrenic nerve palsy, acute tubular necrosis, and transient ischemic attack, all of which resolved completely, were identified. The actuarial 5- year survival rate is 64%. We conclude that modification of the sutureless intraluminal ring graft to suit the pathology encountered at operation allows the quickest repair with the least chance of anastomotic complication. (Ann Thorac Surg 1990;50:74-9) urgical management of diseases of the ascending aorta S and aortic arch is associated with high morbidity and mortality [ In part, these complications result from technical difficulties with the use of conventional tube grafts, including suture line hemorrhage through friable tissue [l, 51. In addition, prolonged insertion times increase the risk of myocardial injury and cerebral ischemic damage. To avoid anastomotic complications and minimize graft insertion time, we began using sutureless intraluminal ring grafts for descending aortic dissections in 1976 and extended this practice to the ascending aorta in In this report, we review our 10-year experience with this device in the ascending aorta and aortic arch. Material and Methods Between 1978 and 1989, 49 patients underwent replacement of the ascending aorta or aortic arch with a sutureless intraluminal prosthesis. (The first eight devices were handmade in the Temple University machine shop. All remaining grafts were made by Bard, Inc [Billerica, MA].) Twenty-three of the patients were operated on during the first half of the study period, and 26 were operated on during the second half. Figure 1 summarizes patient profiles and treatment. Thirty men and 19 women were involved in the study; their ages ranged from 15 to 77 Accepted for publication Jan 29, Address reprint requests to Dr Oz, Department of Surgery, Box 170, Columbia-Presbyterian Medical Center, 622 W 168th St, New York, NY years (mean age, 57 years). The follow-up period was 104 months (mean follow-up, 49 months). Eight operations involved placement of the graft in the aortic arch, and 41 involved insertion into the ascending aorta. Fifteen patients (31%) were taken to the operating room under emergency conditions. Among the patients requiring replacement of a diseased portion of the ascending aorta, 13 had acute dissections, 4 had chronic dissections, and 24 had atherosclerotic aneurysms. Among the 8 patients requiring operation on the aortic arch, 4 had atherosclerotic aneurysms and 4 had dissections, two of which were acute. Twenty-six patients (53%) underwent aortic valve replacement at the time of their aortic operation; 20 of these individuals had aneurysmal disease. Eight patients (16%) required concomitant coronary artery bypass grafting. Four patients had an aortoatrial polytetrafluoroethylene (PTFE) shunt placed at the completion of the procedure. Most patients underwent digital subtraction angiographic evaluation of the ring graft before discharge from the hospital. A few patients underwent long-term follow-up with digital subtraction angiography, computed tomography, or magnetic resonance imaging to evaluate ring graft function. Serum hemoglobin and haptoglobin levels were measured in select patients to evaluate hemolysis. Operative Technique The sutureless intraluminal ring graft may be modified to suit the pathological condition found during replacement of the ascending aorta and aortic arch by The Society of Thoracic Surgeons /$3.50

2 Ann Thorac Surg 1990;50749 OZETAL Cases 21 Dissections 28 Aneurysms 15 Acute 6 Chronic /\ /\ /\ / \ 13Ascend 2 Arch 4Ascend 2 Arch 24 Ascend 4 Arch ( :9CAvz) (1 AVR) 6 :Go) (; 2KQ) Fig 1. Flow chart of patients undergoing replacement of the ascending aorta and aortic arch shows underlying disease and treatment required. (AVR = aortic valve replacement; CABG = coronary artery bypass grafting.) ACUTE DISSECTION. If the aortic valve is not involved or can be resuspended, the proximal spool of the prosthesis is fixed with five horizontal mattress sutures of 3-0 polypropylene placed at each aortic valve commissure and above each coronary ostium (Fig 2). The spool is secured in place with a 2-mm Dacron tie (Bard, Inc, Billerica, MA). The distal spool then is inserted and secured in place with another Dacron tie placed around the aorta. ANEURYSM WITH AORTIC INSUFFICIENCY. In patients who require simultaneous aortic valve replacement, we remove the proximal ring and suture the Dacron graft to the valve using a running 3-0 polypropylene suture (Fig 3). We most commonly used a Bjork-Shiley valve early in our experience, but later changed to the St. Jude prosthesis. After the composite graft is constructed, the device is inserted into the aorta in a fashion similar to the Bentall procedure [6]. Orifices are created in the graft and are secured at the coronary ostia with running 4-0 polypropylene sutures. The distal ring of the intraluminal device then is inserted, and the spool is secured permanently with external ligatures of nylon tape. Alternatively, we have inserted a valve with an attached PTFE graft and then secured the proximal ring of the intraluminal device within the PTFE sheath using Dacron tape ties. This method allows easier reconstruction of the coronary ostia. Even if the proximal ring is removed to construct an individualized proximal anastomosis, we believe that time is saved by retaining the distal spool for easy insertion. The aortic wall is closed about the graft at the completion of the procedure. If an aortoatrial fistula is deemed necessary, a PTFE graft 6 or 8 mm long is constructed; this graft often closes by the time of follow-up digital subtraction angiographic evaluation, and we have had no complications with these shunts. ARCH ANEURYSM. Rapid replacement of diseased tissue is accomplished using the ring grafts (Fig 4). The grafts are elongated as needed either by suturing two ring grafts together or by using a PTFE graft as a sleeve into which A B Fig 2. (A) Pathology encountered in an acute aortic dissection. The aortic valve is competent. (B) Repair is accomplished with a sutureless device secured above the aortic valve with several nylon sutures above the commissures, followed by Dacron tape ties around the spools and aortic wall.

3 76 OZETAL Ann Thorac Surg IYYO;50:74Y A D B E C F Fig 3. (A) An aortic aneurysm with aortic insufficiency. (B) The anterior aortic wall is incised to show the aortic valve annulus. (C) The proximal spool of a sutureless graft has been remooed, and the free cuff is attached to an aortic prosthetic valve and sutured in place in the usual fashion, including reanastomosis of the coronary arteries. (D) Alternatively, a prosthetic valve attached to polytetrafluoroefhylene material is inserted, and the proximal spool of a sutureless device is secured within the free end of the polytetraf7uoroethyle~le xraft with a Dacron tie. (E) No mutter how the proximal anastomosis is accomplished, the distal spool is inserted and secured zuith Dacron tape. (F) The aortic roall is closed over the ascending aortic graft.

4 Ann Thorac Surg 1990;50:7&9 OZETAL 77 A Fig 4. (A) An aortic arch aneurysm. IB) Tzoo sutureless devices are joined together by retnoving adjoining rings and suturing the free ends together, thus leaving intact rings on either side. An island of tissue incorporating the arch vessels is anastotnosed to the elongated graft. Time ts saved by rapidly fixing the proximal and distal spools within the ascending and descending aorta. B the rings of each sutureless graft can be inserted. The latter technique allows the surgeon to elongate the intraluminal prosthesis as needed. In either case, an island of aortic tissue giving rise to the major vessels is anastomosed to the graft material, and the proximal and distal rings are secured using a single umbilical tape on each end. If the proximal graft must be tailored to incorporate the aortic wall tear or to include an aortic valve, the proximal ring is removed, and the distal ring alone is used. Results Intraoperative complications were uniformly related to hemodynamic compromise before operation. The mean aortic cross-clamp time was 35 minutes in uncomplicated sutureless ring graft placements. Procedures involving insertion of composite aortic valve-ring graft prostheses often required less than one hour of aortic clamping, although some combined procedures took longer. There were four surgical deaths (10%) among patients undergoing replacement of the ascending aorta, all of which occurred within the first 24 hours after operation. Three of these deaths involved hemodynamically unstable patients who had emergency operations and intraoperative cardiac arrest. The other death occurred when ventricular failure developed in a patient with a chronic ascending aortic aneurysm who underwent concomitant aortic valve replacement. Three early deaths (37%) occurred in hemodynamically unstable patients undergoing emergency aortic arch replacement. One operative death (4%) was identified among the 24 patients (62%) requiring replacement of an ascending aortic aneurysm. Seventeen patients underwent operation to repair an acute or chronic ascending aortic dissection; three operative deaths occurred (18%). None of the deaths resulted from graft dysfunction. Nonfatal early complications included individual cases of transient ischemic attack, wound infection, phrenic nerve palsy, acute tubular necrosis, and chest wall bleeding, which necessitated reoperation. All of these difficulties resolved without sequeiae or morbidity. There was no evidence of graft dislodgement, graft infection, aortic bleeding, or pseudoaneurysm formation in the postoperative period. One patient with Marfan s syndrome required reoperation 18 days postoperatively to repair an acute dissection in the descending aorta that had not been present at the initial procedure. At this time, 35 patients (73%) are still alive, with an actuarial 5-year survival rate of 64%. The leading causes of late death were arrhythmias and myocardial infarction. Randomly selected patients were followed with digital subtraction angiography, computed tomography, or magnetic resonance imaging and showed no evidence of graft

5 78 02 ETAL Ann Thorac Surg 1990:50:74-9 migration, erosion, or thrombosis. In several patients, serum hemoglobin levels were checked at various intervals up to 4 years after insertion of a sutureless device. No hemolysis was evident from these studies. At autopsy, the aortic tissue adjacent to the spools was densely fibrotic and sometimes was completely replaced with fibrous tissue. No pseudoaneurysms have been identified. The grafts have remained intact without evidence of kinking or dislodgement. Comment Since Abbe [7] first used a thin vitrilline hourglass-shaped tube to repair severed femoral vessels in 1894, vascular surgeons have been interested in using a sutureless prosthesis to repair diseases of the aorta surgically. Because of the risks of prolonged ischemia during replacement of the aorta and because sutured anastomoses can be difficult when the aorta is soft and friable, a sutureless method was appealing. By 1912, Carrel [8] had attempted intubation of the aorta with metallic tubes. However, it was not until a decade ago that our group [9, 101 and others [ll, 121 reported success using variations of intraluminal devices. Our results using sutureless intraluminal devices in the ascending aorta are comparable with those reported with use of conventional sutured anastomoses. The mortality rate for ascending aortic aneurysms is reported to be 5% to 13% [l, 131, and that for ascending aortic dissections is 8% to 27%, depending on the acuteness of the aortic wall tear [14]. Bleeding complications, which have necessitated reoperation in 11% of patients in past studies [l], did not cause serious problems for our patients. Pseudoaneurysm formation, another potentially devastating complication, also was not identified in this study. Avoiding anastomoses with friable, diseased aortic tissue provided for these results. In addition, the operations were completed quickly owing to the ease with which the ring grafts can be inserted. Even if the encountered pathology required a proximal sutured anastomosis, time was saved by using a spool instead of sutured distal anastomosis. Partly as a result of these advantages, postoperative complications were reduced, and none of the patients who survived the initial 24-hour postoperative period died in the hospital. Three possible complications may occur with insertion of a sutureless intraluminal prosthesis: (1) thrombosis or embolism, (2) hemorrhage or pseudoaneurysm development due to erosion of the wall of the aorta, and (3) migration of the prosthesis due to insufficient fixation. None of these complications has occurred in the 104- month follow-up of the patients in this study. Several technical developments provide for these results. We use a woven Dacron graft on surfaces exposed to blood to induce an adherent neointima and minimize the possibility of a thromboembolism. The graft also is preclotted by autoclaving in the patient s plasma for three minutes. The outer surface of the spools is lined with Dacron cloth, which induces sufficient scarring to hold the prosthesis in place [15]. Finally, the broad design of the spool and the vascular nature of the aortic wall make erosion after tying of the spool unlikely. This complication has never occurred in our patients. Surgeons without experience with the sutureless intraluminal devices often use too wide or too long a graft for the involved aorta. Reduction of the aortic lumen by up to 70% produces no increase in intravascular hemolysis and creates no flow-related insufficiencies. For this reason, when selecting graft diameter, error on the side of a smaller graft is warranted. We size the ascending aortic lumen with valve obturators and choose a graft diameter that fits comfortably within the proposed vessel. In our experience, a 24-mm diameter graft is used most often; infrequently, we use devices 22 and 26 mm in diameter. Use of too long a graft results in kinking, with serious hemodynamic complications. The Dacron grafts stretch 30% after intraaortic insertion; therefore, a graft length that is shorter than the diseased aortic segment should be selected. Again, too little graft is better than too much. If a composite PTFE device is used, the PTFE can be fixed to the ring after insertion, when a more precise determination of the optimal graft length has been made. Incorrect placement of fixation ligatures on the spools is a final danger encountered during the learning process. We routinely place two ties on the spools and sometimes apply a third tie on the graft material itself between the spools to prevent blood leakage through the graft-spool interface. When stabilizing the spool, care must be taken to ensure that the posterior surface of the spool is in contact with the tie before tension is applied on the ligature. This avoids dislodgement of the device and prevents inadvertent injury to the aortic wall by the shearing force of the ligature pulling the aortic back wall over the spool. Although sutureless intraluminal devices are especially useful in aortic dissections, we now are using these grafts routinely in aortic aneurysms and infected aortitis [16]. The advantages over sutured anastomoses are not as great; however, the reduction in operative time warrants use of a sutureless graft in these situations, especially if the patient s condition is unstable. References 1. Kouchoukos NT, Marshall WG Jr, Wedige-Stecher TA. Eleven-year experience with composite graft replacement of the ascending aorta and aortic valve. J Thorac Cardiovasc Surg 1986;92: Daily PO, Trueblood HW, Stinson EB, et al. Management of acute aortic dissections. Ann Thorac Surg 1970;10: Rosenberg HL, Mulder DG. Dissecting thoracic aortic aneurysms. Arch Surg 1972;105: Wheat MW Jr, Palmer RF, Bartley TD, Seelman RC. Treatment of dissecting aneurysms of the aorta without surgery. J Thorac Cardiovasc Surg 1965;50: Edwards WS, Kerr AR. A safer technique for replacement of the entire ascending aorta and aortic valve. J Thorac Cardiovasc Surg 1970;59: Bentall HH, DeBono A. A technique for complete replacement of the ascending aorta. Thorax 1968;3:33%9. 7. AbbC R. The surgery of the hand. NY Med J 1894;59: Carrel A. Results of the permanent intubation of the thoracic aorta. Surg Gynecol Obstet 1912;15:245.

6 Ann Thorac Surg 1990;50:749 OZETAL Strong MD, Spagna PM, Lemole GM. Sutureless prosthesis for aortic aneurysms [Letter]. Chest 1979;75: Lemole GM, Strong MD, Spagna I M, Karmilowicz NP. Improved results for dissecting aneurysms. Intraluminal sutureless prosthesis. J Thorac Cardiovasc Surg 1982;83: Dureau G, Villard J, George M, Deliry 1, Froment JC, Clermont A. New surgical technique for the operative management of acute dissections of the ascending aorta. Report of two cases. J Thorac Cardiovasc Surg 1978;76: Ablaza SGG, Ghosh SC, Grana VP. Use of a ringed intraluminal graft in the surgical treatment of dissecting aneurysms of the thoracic aorta. J Thorac Cardiovasc Surg 1978;76:39M. 13. Crawford ES, Crawford JL. Diseases of the aorta: including an atlas of angiographic pathology and surgical technique. Baltimore: Williams & Wilkins, 1984: Miller DC, Stinson EB, Oyer PE, et al. Concomitant resection of ascending aortic aneurysm and replacement of the aortic valve: operative and long-term results with conventional techniques in ninety patients. J Thorac Cardiovasc Surg 1980;79: Koyamada K, Ishikawa S, Yamaki S, Kakihata H. Surgical treatment for dissecting aneurysm of the aorta using a double ringed graft. J Cardiovasc Surg 1985;26:48& Oz MC, McNicholas KW, Serra JS, Spagna PM, Lemole GM. Review of Salmonella mycotic aneurysms of the thoracic aorta. J Cardiovasc Surg 1989;30: