D aging [l] that begins in the ascending aorta and. Simultaneous Total Aortic Replacement From Valve to Bifurcation: Experience With 21 Cases

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1 Simultaneous Total Aortic Replacement From Valve to Bifurcation: Experience With 21 Cases Carlo G. Massimo, MD, Luigi F. Presenti, MD, Piero P. Favi, MD, Clemente Crisci, MD, and Eduardo A. Cruz Guadrbn, MD University of Florence and Careggi General Hospital, Florence, Italy, and Instituto Salvadoregno del Corazh, San Salvador, El Salvador From June 1985 to December 1991, 21 patients (12 men and 9 women; mean age, 60 years) underwent total simultaneous aortic replacement that extended from the valve to the bifurcation. The causes of the diseased aorta were: medial degeneration with total aortic dilatation or multiple aneurysms (n = 7) and either acute (n = 4) or chronic (n = 10) dissection. Clinical evaluation and investigation in all patients consisted of computed tomography and magnetic resonance imaging as well as angiography. Only patients with combined thoracic and abdominal emergencies were selected, and these comprised worsening of cardiac conditions resulting from aortic regurgitation, and rapid dilatation of the ascending aorta and arch with impending rupture in conjunction with ischemia of the abdominal viscera, kidney, or either leg. The surgical technique consisted of inducing deep hypothermia by means of femoral vein-femoral artery cardiopulmonary bypass. During the cooling time, the aortic root was replaced under cardioplegia. Once lowering of the body temperature attained electroencephalographic silence, circulation was stopped and the aorta was replaced from the arch to the bifurcation. Circulation and rewarming were resumed only after the operation was completed. In our most recent patient, the operating time was reduced by opening the thoracic and the abdominal incisions during cooling; the cardioplegic solution was not injected but, instead, the myocardium was cooled down along with the whole body. In these patients, the hypothermy at electroencephalographic silence ranged from 14' to 19OC. Only once did the cerebral ischemia exceed 60 minutes. In 14 patients, the intercostal arteries were reconnected. All patients survived operation. Three (14.2%) died within 1 month, and neurologic disturbances of the lower extremities, which affected 3 patients, disappeared within 2 months. Follow-up in the 18 surviving patients ranged from 2 months to 7 years. There were two late deaths after 4 and 6 years, and the actuarial 5-year survival estimate, including the operative mortality, was 72%. Combined emergencies of the thoracic and abdominal aorta were the indication for this operation. Considering the acceptable surgical risk involved, we think that elective indications should also be considered for such a procedure. (Ann Thorac Surg 1993;56:111&6) egeneration of the elastic fibers is a phenomenon of D aging [l] that begins in the ascending aorta and spreads to the periphery, affecting the whole length of the vessel. It involves the progressive replacement of normal tissue by connective tissue, such that the aorta is changed into a rigid tube that is prone to the development of pathologic conditions. According to Crawford and associates [2], in more than half of the patients with an aortic aneurysm, regardless of the location, there is multiple involvement, so that, after a thoracic aneurysm is resected, the persistence of the degeneration or development of a new distant aneurysm is considered a predictor of late death. Nef and colleagues [3], in 1975, reported on a patient who had undergone total aortic replacement in a staged approach carried out during a 9-year period. These and other observations spawned the idea for a study of total aortic replacement [4] in patients with aneurysm, Accepted for publication Dec 28, Address reprint requests to Dr Massimo, Via A. Man, 14, Fiesole, Florence, Italy. which consisted of replacing all involved segments, larger than 5 cm, in good-risk patients [2]. Based on the findings from this study, it was concluded that extended aortic resection is frequently appropriate for the treatment of aortic disease. In 1982 at our institution [5], a patient with an acute retrograde, type B dissection that did not reach the aortic valve was successfully treated by a total simultaneous aortic replacement that extended from, and included, the arch to the bifurcation. This was performed through a left thoracotomy [6]. A report on the first 6 patients who underwent such an operation was presented in 1985 and published in 1986 [7]. In the same year, our program of total simultaneous aortic resection, including the aortic valve, was initiated. The study described here was designed to examine our experience with this operation. Material and Methods Patients Twenty-one patients, 12 men and 9 women, whose ages ranged from 49 to 69 years (mean age, 60 years) under by The Society of Thoracic Surgeons /93/$6.00

2 Ann Thorac Surg 1993;56: MASSIMO ET AL 1111 Table 1. Causes of Aortic Diseases in 21 Patients Under,qoin,q Simultaneous Aortic Replacement Morphologic Features Histopathologic Features Dilatation Dissection No. of Medial Giant Cell Marfan Patients Total Multiple Acute Chronic Degeneration Aortitis Syndrome 12 males females a Mean age, 60 years. went simultaneous total aortic replacement between June 1985 and December Four patients had total aortic dilatation, 3 had multiple aneurysms, and 4 had an acute and 10 had a chronic aortic dissection. Medial degeneration was considered the cause in 16 patients, giant cell aortitis in 2, and Marfan syndrome in 3 (Table 1). There was aortic insufficiency of various degrees in all patients. In 12 this was due to cusp prolapse; in 7, to annular dilatation; and in 2, to heavy calcification (Table 2). Nine patients were admitted with anterior chest pain: 4 had subadventitial rupture of the ascending aorta or arch, including 1 with rupture in the left lung; 5 had rapidly increasing dilatation of the ascending aorta or arch, including laryngeal paralysis in 1. Ten patients presented with heart failure stemming from aortic valvular insufficiency; angina was present in 2. Two patients presented with neurologic disturbances of the spine resulting from increasing dilatation of the descending thoracic aorta. With regard to involvement of the distal aorta, 10 patients had signs of visceral or renal ischemia and 8 had ischemia of one or both inferior limbs (see Table 2). Three patients had abdominal pain resulting from fissuration of an abdominal aortic aneurysm. Patients were classified on the basis of their symptoms according to the New York Heart Association (NYHA) classification: 9 (42.8%) were in functional class IV, 10 (47.6%) in class 111, and 2 (9.5%) in class 11. All patients underwent a complete study, despite their critical conditions. Magnetic resonance and computed tomographic scanning plus aortography were performed to obtain more complete information to permit selection of the appropriate surgical technique. This allowed confirmation of the aortic valve insufficiency; the aortic annulus, the coronary ostia, and the aortic root were assessed; and the aortic arch was investigated with regard to the origin of the carotidosubclavian vessels. Attempts at visualizing the lower intercostal and spinal arteries were always unsuccessful. Particular attention was paid to locating the origin of the visceral, renal, and iliac arteries: patients in whom these vessels could not be reattached on a single button were ruled out as candidates, as well as those in whom bisiliac or bifemoral anastomoses were necessary for the distal aortic reconstruction. This policy was adopted to reduce the time needed for abdominal aortic grafting. Surgical Technique Replacement of the entire aorta is a technical problem that involves a period of ischemia affecting the whole body, as well as blood losses and coagulation disturbances. Cardiocirculatory arrest under profound hypothermy is the only way to achieve this goal. The patient is first placed on the operating table in the supine position, and slightly tilted to the right to expose his or her left side. A routine vertical midsternotomy with Table 2. Clinical Presentation of 21 Patients With Aortic Insufficiency Under,qoin,q Simultaneous Aortic Repair Critical Abdominal Symptoms Critical No. of Thoracic Spinal Lower Patients Symptoms Deficit Visceral Renal Limbs Combined 12 males females Fig 1. Skin incisions made in the chest and abdomen.

3 1112 MASSIMO ET AL Fig 2' After cardiopulmonay and are the temperature is dropping, the ascending aorta is cross-clamped and the cardioplegic solution is injected. extension into the left chest (fourth intercostal space) is made to expose the thoracic aorta from the valve to the diaphragm. To expose the aorta from the diaphragm to the bifurcation, a thoracoabdominal incision is then made. The skin incision is started from the level of the pubis and brought upward along the median line to the umbilicus, then angled to the left and ended in the eighth intercostal space at the midaxillary line after crossing the costal border (Fig 1) [8]. Once the costal border is interrupted, the extraperitoneal dissection is carried downward to detach the peritoneal sac from the abdominal wall; in addition, the left hemidiaphragm is detached from its circular parietal insertion. Extracorporeal circulation is instituted by cannulating a femoral artery and the right femoral vein and advancing the venous cannula to the right atrium. The left side of the Fig 3. After the aortic valve is removed, the aortic root is replaced with a composite valve graft and the coronay orifices are reimplanted. Ann Thorac Surg 1993;56111M Fig 4, The aortic graft, fashioned to the appropriate length, is anastomosed to the orifices of the carotidosubclavian vessels, heart is vented through the right superior pulmonary vein. Cardiopulmonary bypass and cooling are initiated. While the temperature is dropping, the ascending aorta is cross-clamped (Fig 2) and the heart is stopped with the injection of a cold cardioplegic solution. The aorta is opened, and, after the aortic valve has been removed, a composite valve graft prosthesis (previously elongated with an albuminized Dacron tube of the same-size) is set into place using a 3-0 monofilament continuous suture. Coronary reconnection is obtained either by direct reattachment or by graft interposition, depending on the indication (Fig 3) [9]. By the end of this process, lowering of body temperature has generally attained electroencephalographic (EEG) silence (15" to 19'C). The operating table is rotated to the right, and the sternothoracotomy is opened to expose the aortic arch. The cardiopulmonary bypass is stopped with the patient in the head-down position and the carotid trunks are cross-clamped. The incision in the ascending aorta is continued into the arch, taking care to avoid injury to the laryngeal nerve, and is extended to the diaphragm. After the graft has been inserted into the aortic lumen, the aortic arch is reconstructed by anastomosing the carotidosubclavian orifices in a single button to the side of the graft (Fig 4). Replacement of the thoracoabdominal aorta is then begun. To start with, the thoracoabdominal incision is opened, and the peritoneal sac and the left hemidiaphragm are moved to the right, allowing wide exposure of the aorta from the midthoracic portion to the bifurcation. The incision of the thoracic aorta is continued distally (Fig 5), passing behind the takeoff of the left renal artery. First, the aortic lumen is inspected at the superior edge of this incision and the intercostal orifices are tied up; the lower pairs (eight to ten), if patent, are anastornosed to the side of the aortic graft (see Fig 5). Subsequently, the graft is stretched into the lumen of the abdominal aorta and the

4 Ann Thorac Surg 1993;56:111M Fig 5. The intercostal orifices are tied u p and the lower pairs are anastornosed to the graft. celiac axis, and the superior mesenteric artery and both the renal and inferior mesenteric arteries are anastornosed to the side of the graft in a single button (Fig 6). To include in a single anastomosis as many vascular orifices as possible, sometimes the mouth of the distal aorta is also encompassed, together with the visceral arteries. Using this technique, no more than two abdominal anastomoses are generally required (Fig 7; Table 3). At the completion of the procedure, air is evacuated from the graft and rewarming is started. Cardiac activity generally resumes at 34 C and proceeds spontaneously to sinus rhythm, so that, at 36"C, the patient is weaned off the pump without mechanical support. While still on the operating table, the patient is wrapped in a heat blanket to maintain normothermia and then transported to the intensive care unit. All patients in this series were extubated Fig 6. The orifices of the visceral and renal arteries are anastornosed to the graft on a single button. MASSIMO ET AL 1113 Fig 7. The distal end of the graft is reconnected to the distal aorta near the bifurcation. on the first postoperative day and discharged an average of 25 days after the operation. The mean myocardial ischemic time in these patients was 94 minutes; the mean duration of total body ischemia under profound hypothermia was 55.5 minutes (range, 45 to 66 minutes). The duration of brain ischemia never exceeded 58 minutes; if, after 45 minutes of circulatory arrest, we realized that time was running out, cerebral circulation was resumed at low flow (24 C) through an arterial cannula placed in the right axillary artery in a centripetal direction. This early upper body reperfusion was needed in 9 patients who required an intercostal implant. When the intercostal arteries were not implanted, aortic reconstruction from the arch to the bifurcation took an average of 38 minutes. The average rewarming time for the series was 60 minutes (Table 4). We changed our strategy in our most recent patient, in that, while beginning the skin incision, extracorporeal circulation is instituted by arterovenous cannulation in the right groin and cooling is started. As soon as the sternum is opened, the left side of the heart is decompressed. The thoracic and abdominal openings are completed while the body temperature is lowered to the point of EEG silence. Cardioplegia is not used but, instead, the myocardium is cooled down, along with the whole body. The circulation is then stopped and the operation carried out in the usual fashion during one single period of cardiocirculatory arrest. Using this technique, the operating time has been sensibly reduced. To replace the aortic root, 7 albuminized composite valve grafts with a Bjork-Shiley valve and 14 with a St. Jude valve were used. The valved graft was elongated with a collagen-impregnated tubular Dacron graft that ranged from 24 to 26 mm in diameter (Hemashield woven Dacron double-velour grafts, Meadox Medicals, Oakland, NJ). For every patient, 10 units of blood, 9 units of plasma, and 5 units of platelets were available, but bleeding never posed a problem. Tranexamic acid (an antifi-

5 1114 MASSIMO ET AL Ann Thorac Surg 1993; Table 3. Technical Data and Extent of Aortic Replacement Replaced Aortic Segments Reimplanted Vessels No. of Ascending Descending Abdominal Coronary Abdominal Patients Valve A Arch A A Arteries Carotidosubclavian Intercostal Visceral 12 males females A = aorta brinolytic agent) was administered immediately before and during cardiopulmonary bypass. The postoperative blood loss ranged from 700 to 1,800 ml. Antibiotic prophylaxis using the second-generation cephalosporins cefamandole and cefuroxime was given to all patients. Results Early Outcome All 21 patients survived operation. Three patients died within 1 month, for an overall mortality rate of 14.2%: one death was due to low cardiac output after reoperation for the control of bleeding from the reattachment of the left coronary ostium; another patient died of myocardial infarction, and the third died of stroke. Transient renal failure requiring dialysis occurred in 2 patients. One patient had central neurologic disturbances that disappeared in 10 days. Neurologic disturbances of the lower extremities developed in 3 patients, all of whom had had lower intercostal arteries reimplanted, 12, 16, and 24 hours after operation, but all had recovered completely after 2 months (Table 5). Late Outcome Follow-up in the 18 surviving patients has ranged from 2 months to 7 years. There were two late deaths, which brings the total mortality to One of these patients died of sepsis stemming from an infected thrombus at the distal anastomosis of the graft; the other patient died after 6 years of multisystemic failure. The actuarial 5-year survival estimate, including the operative mortality, was Table 4. Ischemic Times and Body Temperature Variable No. of patients Average cooling time Body temperature at arrest Average myocardial ischemic time Brain ischemic time Average total body ischemic time Average rewarming time Early recirculation min 15"-19"C 94 min Value 258 min 55.5 min (45-66 min) 60 min 9 patients 72% (Fig 8). Ten patients are in NYHA functional class I, 5 are in class 11, and 3 are in class 111. Comment Total aortic replacement should be considered the ideal treatment for disease involving the whole aorta. In patients with an aneurysm of the aortic arch associated with distal aortic disease, Crawford and colleagues [lo] carried out total aortic replacement using a staged approach. They concluded that, in good-risk patients, all involved segments larger than 5 cm in external diameter should be removed because of the low operative risk involved. Facing the same problem, Borst and associates [ll] introduced the "elephant trunk" technique to facilitate extended and total replacement in a staged operation. Performing total aortic replacement in a staged approach carries a relatively low operative risk. In their series of patients, Crawford and co-workers [2] observed a late mortality of 21% after the two operations, but many of their patients were lost in the interval between the two operations, because they refused reoperation or died from rupture of a residual distant aneurysm, or because of the progressive deterioration in their general conditions, which obviated the second operation. We think, therefore, that total replacement accomplished at one operation should be the procedure of choice in many cases, provided the surgical risk is acceptable. In our series, none of the three early deaths was related to the magnitude of the operation itself. The profound hypothermy during circulatory arrest was effective to protect the whole body. We tried to contain the period of brain ischemia within 60 minutes. This limit proved to be safe because all patients were alert on awakening. Central neurologic disturbances arose only in 1 patient, but had Table 5. Earlu Results According to the Patholorn Neurologic disturbances No. of Pathology Patients Transient Permanent Death" Dilatation Dissection Acute Chronic 10 a Overall early mortality, 14.2%.

6 Ann Thorac Surg 1993;56:111M MASSIMO ET AL 1115 disappeared completely within 10 days and were attributed to the presence of gaseous emboli. Myocardial protection was effective for arrest times of up to 94 minutes; a single dose of crystalloid was injected at the moment of aortic cross-clamping to induce cardioplegia, and later protection was provided by lowering the body temperature. Upon rewarming, electrical activity proceeded to spontaneous rhythm, and, after the patient was weaned from the bypass, cardiac action proved to be efficient to sustain circulation without mechanical assistance. No visceral failure could be related to the ischemic time, not even the 2 cases of renal insufficiency because renal function in these 2 patients was already impaired before operation. Paraplegia was never encountered, but 3 patients, who had had the intercostal arteries reimplanted, suffered transient neurologic disturbances in their lower extremities. This low incidence of ischemic spinal damage confirms the protective value of hypothermia that we have always supported [12], in agreement with Kouchoukos and colleagues [13], and now also confirmed by the experience of Berguer and associates [14]. Two patients died after 4 and 6 years, due in one to sepsis and in the other to multiorgan failure. Other possible aortic complications did not occur. Our experience indicates that graft replacement therapy prolongs life in patients with extensive aortic disease, in that the 5-year survival of 72% rises to 89% if operative mortality is excluded and only the surviving patients are considered (see Fig 3). Our new strategy of opening the thoracic and abdominal incisions while the body temperature is dropping was successfully used in the most recent patient. Despite this success, further experience is needed, but we believe this technical simplification opens up more prospects for this operation. In the present series, simultaneous total aortic replacement was reserved for patients with combined thoracic and abdominal emergencies, in whom sufficient time for a Fig 9. Angiogram of a total aortic graft 23 months after operation. YO 20 I complete preoperative investigation was nevertheless allowed. Considering the relatively low operative mortality involved, we think that this approach should also be evaluated for use in elective operations. 0 I I I References 1. Schlatmann TJM, Becker AE. Histologic changes in the normal aging aorta: implications for dissecting aortic aneurysm. Am J Cardiol 1977;39:1% Crawford ES, Coselli JS, Svensson LG, Safi HJ, Hess KR.

7 1116 MASSIMO ET AL Ann Thorac Surg 1993;56: 111C-6 Diffuse aneurysmal disease (chronic aortic dissection, Marfan, and mega aorta syndromes) and multiple aneurysm. Treatment by subtotal and total aortic replacement emphasizing the elephant trunk operation. Ann Surg 1990;211: Nef J, Meyer J, Cooley DA. Aneurysmal dilatation of the entire aorta: surgical management of an unusual case. Texas Heart Inst J 1975;2: Crawford ES, Cohen ES. Aortic aneurysm: a multifocal disease. Arch Surg 1982; Borzoni GC, Moretti R, Massimo CG, et al. Resezione dell - arc0 aortico, dell aorta discendente e dell aorta addominale con l impiego di un tempo di arrest0 arcolatorio in ipotermia moderata. Osp It Chir 1982;35: Crawford ES, Coselli JS, Safi HJ. Partial cardiopulmonary bypass, hypothermic circulatory arrest, and posterolateral exposure for thoracic aortic aneurysm operation. J Thorac Cardiovasc Surg 1987;94:82&7. 7. Massimo CG, Poma AG, Viligiardi RR, et al. Simultaneous total aortic replacement from arch to bifurcation: experience with six cases. Texas Heart Inst J 1986;13: Massimo CG, Favi PP, Ponzalli M, et al. Total simultaneous aortic replacement [Abstract]. J Am Coll Cardiol 1990;15: 230A. 9. Massimo CG, Presenti LF, Viligiardi RG. Coronary reattachment in resection of the aortic root [Abstract]. J Am Coll Cardiol 1991;17363A. 10. Crawford ES, Stowe CL, Crawford JL, et al. Aortic arch aneurysm: a sentinel of extensive aortic disease requiring subtotal and total aortic replacement. Ann Surg 1984; Borst HG, Walterbusch G, Schaps D. Extensive aortic replacement using elephant trunk prosthesis. Thorac Cardiovasc Surg 1983;31: Massimo CG, Favi PP, Balestra N, Wiechmann V. Surgical treatment of descending thoracic aortic aneurysms by patch grafting: a technique to avoid spinal cord damage. Bull Texas Heart Inst 1977; Kouchoukos NT, Wareing TH, Izumoto H, Klausing W, Abboud N. Elective hypothermic cardiopulmonary bypass and circulatory arrest for spinal cord protection during operations on the thoracoabdominal aorta. J Thorac Cardivasc Surg 1990; Berguer R, Porto J, Fedoronko B, Dragovic L. Selective deep hypothermia of the spinal cord prevents paraplegia after aortic cross-clamping in the dog model. J Vasc Surg 1992;15: REVIEW OF RECENT BOOKS Cardiac Mechanical Assistance Beyond Balloon Pumping Edited by Susan 1. Quaal, PhD, RN, CVS, CCRN St. Louis, MO, Mosby-Year Book, pp, 125 illustrations, $29.00 Reviewed by Moisb Calderbn, MD, and Raul Verdin, MD This book presents a comprehensive, yet concise, summary of the state-of-the-art technology and clinical experience with mechanical cardiac support. It is well-referenced and up-to-date, and contains excellent illustrations and tables, adequately discussed in the text. The chapters have been written by physicians, nurses, clinical engineers, and perhsionists; all are members of international and recognized reference centers in ventricular assistance. The book is divided into five parts. The first part discusses the overview of ventricular failure and mechanical support. Part two comprises a number of chapters reviewing the international clinical experience with the application of partial and total cardiac assist device-from the roller pump to the total artificial heart. It also gives a glimpse into ventricular assist technology in Japan and the former Soviet Union. The last three parts of the book represent superb reviews and discussions of the development of ventricular assist devices, clinical and experimental programs, the engineer s and perfusionist s role as part of the team, biomechanical support, and all ethical issues associated with assisted circulation. The overall text is authoritative, up-to-date, well-organized, generously illustrated, and very readable. It is certainly a useful reference for all the members of transplant and circulatory support departments. Mexico City, Mexico