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New surgical approach to aortic dissection: Flow reversal and thromboexclusion
J
THoRAc CARDIOV ASC
S URG 81 :659-668, 1981
Original Communications
New surgical approach to aortic dissection: Flow reversal and thromboexclusion With the aim or decreasing the complications and mortality associated with the current techniques for aortic dissections, \I'e have developed an operation which consists or bypassing the dissected aorta and creating fiow reversal in the dissected segment, Seven patients with either acute (five} or chronic aortic dissections (two) \I'ere operated upon success/idly, with no early or late deaths. Three transient postoperative complications \1'1'1'1' encountered: loll' cardiac output, hemiparesis, and renal insufficiency, Postoperative arteriography \I'as performed in five patients and demonstrated exclusion or the dissected lesions by thrombosisfollowing jiow reversal in the descending aorta, Follow-up is available from 2 to 28 months (average 13 months). with 110 long-term complications,
A, Carpentier, M,D, (by invitation), A, Deloche, M,D, (by invitation), J. N. Fabiani, M.D. (by invitation), S. Chauvaud, M.D. (by invitation), J. Reiland, M.D. (by invitation), R. Nottin, M,D. (by invitation), P. Vouhe , M.D. (by invitation), H. Massoud, M.D. (by invitation), and Ch. Dubost, M.D., Paris, France
Aortic dissection continues to be associated with a high incidence of early and late mortality despite continued progress in surgical technique and myocardial protection. The various factors responsible for this poor prognosis have been examined both experimentally and clinically, and a technique has been developed to overcome the most frequent complications: bleeding, suture line dehiscence, recurrent dissection, rupture, and ischemia.
Concept of thromboexclusion by blood flow reversal in the descending aorta Most of the complications associated with the currently used operations for aortic dissection result from From Laboratoire d 'Etudes des Protheses Cardfaques-c. N.R. S., and Association Claude Bemard-H6pital Broussais, Paris, France. Read at the Sixtieth Annual Meeting of The American Association for Thoracic Surgery, San Francisco, Calif., April 28 to 30, 1980. Address for reprints: Alain Carpentier, M.D" H6pital Broussais, 96 rue Didot, 750l4-Paris, France,
the following two factors: The anastomotic sutures to the Dacron graft are placed in the dissected aorta, which may lead to hemorrhage or suture line disruption because of the fragility of the tissues. The resection of the dissected aorta is limited and a large dissected portion is left in place, so that the potential remains for recurrent dissection, rupture, or ischemia in the postoperative course. Our efforts were directed toward an operation that would avoid sutures in the dissected areas and effectively correct the lesions. This was to be achieved by reversing the flow in the dissected aorta and producing subsequent thrombosis and exclusion of the lesions (Fig. 1). This technique is based on the following principles: Arterial reconstruction is accomplished by an aortoaortic bypass graft that is sutured to the nondissected areas of the aorta and thereby avoids the dissected aorta. A permanent clamp placed at the upper limit of the dissection effectively reverses the flow in the descending aorta. Blood flow in the true lumen is partially restored and the size and extent of the false lumen is reduced. The stagnating blood thromboses in the false
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Fig. 1. Concept of flow reversal and thromboexclusion of aortic dissection. I, A Dacron graft is placed so as to bypass the dissected aorta. 2, A permanent clamp is placedat the upper limit of the dissection.3, Flow reversal in the descending aorta restores blood flow in the true lumen and reduces the size and extent of the false lumen. 4, Thrombosis in the false lumen and in the segment of the aorta devoid of major branches. lumen and in the segment of the descending aorta devoid of major branches. The progressive nature of the thrombosis allows for a period of circulatory adaptation of the spinal cord. The intra-aortic thrombosis spontaneously limits its distal extent to the major collateral branches of the aorta, the artery of Adamkiewicz, and the intra-abdominal branches.
were ligated. A specially designed permanent clamp* was subsequently placed distal to the proximal anastomosis of the bypass graft and proximal to the site of dissection (Fig. 2). Four dogs survived, and in all cases thrombosis occurred in the false lumen and the distal portion of the true lumen corresponding to the area of ligated intercostal branches.
Experimental evaluation
Clinical experience
Five mongrel dogs were operated upon by means of a left lateral thoracotomy through the sixth intercostal space. A 15 mm by 20 em Dacron bypass graft was sutured between the descending aorta distal to the subclavian artery and the supradiaphragmatic thoracic aorta. End-to-side anastomoses were constructed with continuous 4-0 Prolene sutures after a partial occlusion clamp had been applied to the aorta. Once the graft was in place and functioning, an aortic dissection was created. This was done by doubly cross-clamping and opening the aorta distal to the proximal anastomosis, by creating a cleavage of the media of the aortic wall with a nerve hook, and by a circumferential partial excision of the inner layer. Following closure of the aorta, cross-clamps were released and blood flow restored to the dissected area. The first two pairs of intercostal branches distal to the site of experimental dissection
Between December, 1977, and February, 1980, seven patients having either acute dissection (five patients) or chronic dissection (two patients) were operated upon by means of the technique of blood flow reversal and thromboexclusion. The age of the patients ranged from 24 to 61 years, average 46 years. There were five men and two women. Four patients had severe hypertension prior to the operation (average blood pressure 220/140 mm Hg). Two displayed the typical features of Marfan 's syndrome and one had no previous medical history. Five patients were operated upon during the acute phase of the dissection, that is, 2, 10, 15, 15, and 20 days, respectively, after the onset of symptoms. There were two type I dissections and one type III dissection. The remaining two patients had *S.A.I.M.A.P. CO Paris.
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Fig. 2. Aortic clamps designed to cross-clamp the aorta permanently.
been previously operated upon for a type II and a type I aortic dissection with replacement of the aortic valve by a valvular bioprosthesis and replacement of the ascending aorta by a Dacron graft. Following the operation, both patients had an acute recurrent dissection of the descending aorta with a left hemothorax. Two patients were operated upon in the chronic phase of dissection, 4 and 10 months after the onset of the initial symptoms. Both of these patients had type III aortic dissections. Operative technique The technique varied depending on the extent of the lesions and the type of dissection. They were classified into four groups: 1. Type III aortic dissection (three patients). The technique did not require extracorporeal circulation and the entire operation was carried out through a median sternotomy and midline abdominal incision. The dissection involved the abdominal aorta in all cases. A nondissected segment of the abdominal aorta was selected which was, in all three cases, the distal portion of the abdominal aorta at the origin of the inferior mesenteric artery. A 22 mm woven USCI Dacron graft was preclotted by being coated with heparinized blood and then autoclaved according to the method of Bethea and Reemtsma.' The graft was implanted end to side after the aorta had been cross-clamped, opened, and the distal vascular bed had been protected from clotting by injection of a heparinized saline solution. After aortotomy, the edges of the aorta were reinforced externally and internally by two strips of Teflon felt sutured
together with the aortic wall in between. The anastomosis was then constructed with a continuous 4-0 Prolene suture. The prosthesis was placed in the retroperitoneum, then routed through the transverse mesocolon and the lesser sac to the diaphragm lateral to the left lobe of the liver. The graft was passed through the diaphragm anteriorly to the inferior vena cava. It was then positioned within the right pleural cavity lateral to the heart. The graft was passed through the pericardium at the level of the aorta. The ascending aorta was partially occluded laterally. End-to-side anastomosis was completed after the edges of the aorta had been reinforced by two strips of Teflon felt as previously described. A permanent clamp was placed across the aorta distal to the left subclavian artery. Adequate vascularization of the abdominal arteries was carefully noted before the sternum and the abdomen were closed. 2. Type I dissection (one patient) (Fig. 3). The procedure was done through a median sternotomy and midline abdominal incision. A 24 mm Dacron bypass graft was placed between the aortic root and the abdominal aorta. The distal anastomosis was performed distal to the renal arteries after the edges of the aorta had been reinforced by two strips of Teflon felt. The Dacron graft was positioned as previously described and brought up into the right pleural cavity. A 15 by 7 mm bifurcation graft was implanted end to side on the aortic Dacron graft for revascularization of the inominate and left carotid arteries. A third 8 mm Dacron graft was implanted on the bifurcation graft for revascularization of the left subclavian artery. The revascularization of these arteries was carried out without extracorporeal
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Fig. 3. Technique for type I aortic dissection. A. Lesions. B, Distal anastomosis to a nondissected segment of abdominal aorta. C. Revascularization of innominate, left carotid, and left subclavian arteries. D. Under extracorporeal circulation, aortic valve replacement and proximal anastomoses. E. Placement of permanent aortic clamp, flow reversal, and thromboexclusion.
Fig. 4. Technique for type I retrograde aortic dissection. A. Distal anastomosis to nondissected segment of abdominal aorta, B. Under extracorporeal circulation, opening, gluing, and reinforcing the ascending aorta. C. Proximal anastomosis. D. Permanent clamp on descending aorta, flow reversal, and thrornboexclusion.
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Fig. S. Technique for recurrent dissection after previous replacement of ascending aorta for type I dissection. A. Previous operation-replacement of aortic valve and ascending aorta. B. Recurrent dissection and rupture into the left pleura. C. Bypass graft between a nondissected segment of the abdominal aorta and the ascending aorta graft. Placement of permanent clamp, flow reversal, and thromboexclusion.
circulation by serial clamping of each vessel under continuous electroencephalographic monitoring. Extracorporeal circulation was then instituted with myocardial protection using a 4° C cardioplegic solution. The ascending aorta was opened. The aortic valve was replaced with a valvular bioprosthesis. As the sinuses of Valsalva were not extensively dissected, the proximal end of the Dacron aortic graft was sutured just above the commissures after the dissected lumina had been stuck together with a biologic glue* and the edges of the proximal aorta had been reinforced with two strips of Teflon felt. The anastomosis was carried out with a continuous 4-0 Prolene suture. A permanent clamp was placed on the distal portion of the ascending aorta. After discontinuation of bypass, adequate vascularization of the major abdominal branches was carefully checked. 3. Type I dissection with origin in the descending aorta (one patient) (Fig. 4). One 50-year-old male patient presented with an acute dissection and minimal aortic insufficiency. At angiography, the dissection was considered to be classical type I. At operation the ascending aorta was found to be dissected in a retrograde *Pharmacie Centrale, Hopital Henri Mondor, Paris, France.
fashion but not ruptured. A 22 mm Dacron graft was sutured to the abdominal aorta just above the bifurcation. Cardiopulmonary bypass was instituted. The ascending aorta was cross-clamped and opened by a right lateral longitudinal incision. As the true lumen had not ruptured and the aortic valve was intact, the aortic layers were approximated firmly together with a biologic glue. The edges of the aorta were further reinforced by two strips of Teflon felt. The proximal end of the bypass graft was then sutured to the aortotomy and a permanent clamp was placed across the aorta distal to the left subclavian artery. 4. Recurrent dissection after previous replacement of ascending aorta (two patients) (Fig. 5). One patient with a type I dissection and one patient with a type II dissection had previously undergone replacement of the ascending aorta according to the current technique of resection and prosthetic replacement. Three months and 12 days, respectively, after this first operation they had recurrent left chest pain and left hemothorax resulting from partial rupture of the descending aorta. This lesion was treated in both cases by flow reversal and thromboexclusion of the descending aorta. A 22 mm Dacron bypass graft was implanted between the abdominal aorta close to its bifurcation and
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Fig. 6. Roentgenograms of patient whose operation is diagrammed in Fig. 5. Left, Preoperative chest x-ray film showing recurrent dissection and left hemothorax. Right, Postoperative chest x-ray film showing complete resolution. Permanent aortic clamp is visible.
the right lateral side of the ascending aortic graft. This did not necessitate extracorporeal circulation. A permanent clamp was then placed across the aorta distal to the left subclavian artery. Even though the ruptured aorta was not treated directly and the hemothorax was not drained, the pain and the hemothorax disappeared completely in the postoperative period in both cases (Fig. 6).
Results All seven patients survived the operation. One patient with a type I dissection had a left hemiparesis which regressed completely within I month. One patient had transient low cardiac output and one had transient renal insufficiency. There were no neurologic complications suggestive of circulatory disturbances to the spinal cord. All patients displayed normal circulation of the lower extremities as assessed clinically and by ultrasonic Doppler technique. Postoperative blood pressures remained identical to the preoperative figures. Aortography was performed in five patients I month after the operation. All showed normal vascularization of the branches of the abdominal aorta and loss of the double contour image of the abdominal aortic lumen. The upper two thirds of the descending thoracic aorta was not filled by the contrast medium, and the intercostal vessels were visible at the junction between the opacified and nonopacified segments (Figs. 7 and 8). One patient with a type I dissection had a body scan combined with repeat intravenous dye injections I month after the operation, and these studies also showed the thrombosis of the lesion (Fig. 9). The patients were discharged from the hospital
without any medication, except for antihypertensive drugs in three patients. The long-term course of all of the patients has been uncomplicated thus far, with a follow-up of 2, 4, II, 13, 16, 18, and 28 months, respectively.
Discussion In the past 10 years, the treatment of aortic dissection" has benefited from successive improvements, among which the most significant have been resection and prosthetic replacement of a limited segment of the dissected aorta, medical treatment aimed at reducing hypertension, and finally the use of biologic glue'': ~ or a ringed intraluminal graft" 6 in order to reduce bleeding at the suture line. Nevertheless, the incidence of operative complications and early mortality remains high, averaging 20% to 50%. The incidence of late complications and late mortality remains even higher, 5% to 10% per patient-year. Actuarial survival at 8 years was recently reported to be 33% to 50% depending on the type of dissections. The technique presented in this paper was developed to improve results. 7-9 The main advantages of this operation are the following: The operation is performed through a single incision regardless of the types of dissection. This presents the unique advantage of diagnosing and treating a dissection which may evolve in an antegrade or retrograde fashion after angiography. The operation can be carried out without extracorporeal circulation in type III dissection and with a reduced bypass time in type I dissection, as the distal anatomoses are performed before bypass is established. The risk of disruption and hemorrhage is reduced, because the sutures are placed in the
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Fig. 7. Type III aortic dissection. Left. Preoperative angiogram. Right. Postoperative angiogram showing flow reversal in the descending aorta and thrombosis of the upper thoracic segment.
Fig. 8. Type I aortic dissection. Postoperative angiograms showing revascularization of innominate, left carotid, and left subclavian arteries (left), retrograde revascularization of abdominal vessels, and lack of opacification above the eleventh intercostal artery (right). nondissected areas of the aorta. If the sinuses of Valsalva and coronary ostia are dissected, the proximal end of the Dacron graft can be sutured to the aortic anulus with coronary revascularization. If the dissection does not extend to the sinuses of Valsalva, the proximal end of the Dacron graft is sutured at the level of the commissures. The latter is preferred in cases of limited
dissection, because sticking the two layers of dissected aorta together with biologic glue and reinforcing the aortic wall with strips of Teflon felt have proved to be effective and safe procedures. The distal anastomosis of the aortic graft is constructed in a nondissected segment of the distal aorta, which may be at the supradiaphragmatic or subdia-
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Fig. 9. Type I aortic dissection. Body scan I month following operation. A, Cut through pulmonary artery (p}, Aortic graft (g) anteriorly is fully opacified. Descending dissected aorta ida) posteriorly showing thrombosis of both false and true lumina. B, Cut through the heart. Aortic graft anteriorly is fully opacified. Descending aorta posteriorly showing true lumen partially opacified and false lumen completely thrombosed. C. Cut through the diaphragm. Aortic graft lateral to the heart is fully opacied. Descending aorta posteriorly showing true lumen fully opacified and false lumen thrombosed. D, Cut through the liver. Aortic graft is fully opacified. and abdominal aorta is fully opacified with no visible dissection.
phragmatic level; the supradiaphragmatic aorta can be approached after dividing the diaphragm, It is usually necessary to implant the distal end of the graft to the abdominal aorta close to its bifurcation. It may be necessary to go even further to the iliac arteries using a bifurcation graft. Flow reversal restores blood flow in the segment of the true lumen which has vital runoff and allows the false lumen to thrombose. The gradual nature of the thrombosis permits a period of adaptation for the spinal cord, as proved by our experience. Although no complications have been observed thus far in the follow-up period of these seven patients, the question as to whether or not these results will withstand time remains to be answered. The long aortic bypass graft per se, described by Shumacker and King.!" does not seem to have caused problems, Wei first utilized this technique in 1969 for cases of complicated coarctation of the aorta, and the first patient operated upon is still alive and well after II years, Since
then, there have been several similar reports of long aortic bypass grafts with excellent results .11* The operation proposed in this paper is indeed based upon a very different concept introducing new unknown hazards: the extent of the thrombosis, the fate of the dissected aorta, vascularization of the spinal cord, abdominal viscera, and the peripheral circulation. One would expect to encounter impaired vascularization of one or more abdominal branches such as the renal or mesenteric arteries after flow reversal. This could conceivably require additional revascularization off the main Dacron graft. The results obtained in this preliminary experience compare favorably with those obtained in our center in an earlier series of patients operated upon by previous techniques." It is therefore our present policy to use the proposed operation in type I and type III acute and chronic aortic dissections. *Brom G: Personal communication.
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Addendum Since this paper was submitted for publication, one additional patient with type III aortic dissection developed paraplegia 6 hours after operation. The patient was reoperated upon immediately, and it was verified that thrombosis had not occurred in the distal segment of the aorta. This complication could have been due to an extension of the dissection before the onset of thrombosis. For technical reasons, the left subclavian artery was clamped during the first operation, and this may have been a contributory factor to this complication. All the patients described in this study continue to do well without complications.
We wish to gratefully acknowledge Dr. Stephen Colvin for help in reviewing the manuscript and Miss Christiane Veneziani for her valuable technical assistance. REFERENCES Bethea MC, Reemtsma K: Graft hemostasis. An alternative to preclotting. Ann Thorac Surg 27:374, 1979 2 De Bakey ME, Henly WS, Cooley DA, Morris GC Jr, Crawford ES, Beall AC Jr: Surgical management of dissecting aneurysms of the aorta. J THORAC CARDIOVASC SURG 49:130-149, 1965 3 Guilmet 0, Liebeaux M, Dhainaut JF, Goudot B, Francoual M, Bachet J: Traitement chirurgical des dissections aigues de laorte ascendante. Arch Mal Coeur 70:639-
644, 1977 4 Wolfe WG, Moran JF: The evolution of medical and surgical management of acute aortic dissection. Circulation
56:503-505, 1977 5 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 76:390-396, 1978 6 Dureau G, Villard 1, George M, Deliry P, Froment JC, Clermont A: New surgical technique for the operative management of acute dissections of the ascending aorta. J THORAC CARDIOVASC SURG 76:385-389, 1978 7 Carpentier A, Guilmet 0, Prigent CI, Gandjbakhch I, Deloche A, Lessana A, Farge CI, Tricot J, Morillo F, Dubost Ch: Aneurysms of the aortic arch, Eighteenth Congress of German Society of Thoracic Surgery, Bad Nauheim, 1969, Thoraxchirurgie Vaski.ilare Chirurgie, Vol 19, Part 5, October, 1971 8 Carpentier A: Dissections aigues de I'aorte , Actualites de chirurgie cardiovasculaire de I'Hopital Broussais, Ch Dubost, A Carpentier, eds., Paris, 1979, Masson & Cie 9 Carpentier A: A new approach to the treatment of aortic dissections. Lancet 2: 1291, 1979 10 Shumacker HB Jr. King H: Surgical management of rapidly expanding intrathoracic pulsating hematomas. Surg Gynecol Obstet 109: 155-164, 1959 II Frantz SL, Kaplin MJ: An alternate operative approach
for the highly diseased abdominal aorta. Cardiovasc Dis Bull Texas Heart Inst 1:1974 12 Anagnostopoulos EE: Acute aortic dissection. Baltimore, 1975, University Park Press 13 Dubost Ch , Guilmet 0, Soyer R: Les anevrysmes de laorte , Paris, 1971, Masson & Cie
Discussion DR. GERALD M. LEMOLE Philadelphia, Pa.
Since 1974, Dr. Strong, Dr. Spagna, and I have been working with a rigid steel spooled Dacron graft placed inside the lumen of the dissector above and below the tear. It was held in place by a strip of Dacron felt. The first five patients were treated by means of this method. However, we had to make these grafts by hand. For convenience sake we began using the USCI manufactured rigid polypropylene spool and a Dacron umbilical tape, although I am not sure whether or not this tape will have a tourniquet effect. We did our first case in 1976 and we have done nine cases since then. Five of these were type I dissections and four were type Ill. There were seven acute and two chronic cases. Of the five patients with type I dissections, two required valves and one required quadruple coronary bypass. Cross-clamp time averaged less than an hour. The pump time and blood usage were approximately one third of what we normally had required prior to this. There were no intraoperative deaths. There was one death in the postoperative third week caused by massive gastrointestinal hemorrhage in a patient who was posted and whose prosthesis was functioning well. Another patient died at 7 months of an infected graft and empyema. We have a 4 year follow-up on these cases. [Slide] This slide shows the first case that was done in 1976. At follow-up 3 years after implantation, the graft was in good position and the continuity of the vessel was proper. Three months ago we had a case in which the cardiologists could not decide whether the patient had an acute dissector or preinfarction angina. As it turned out, both diagnoses were right. He had a false lumen with a tear and left main lesion, an occluded marginal artery, and an occluded right coronary artery. We did an interposition and a triple saphenous vein bypass graft with an internal mammary artery grafted to the anterior descending. Postoperative films show the graft in place and a nuclear scan shows a 60% ejection fraction, We feel that this is the therapy of choice in our hands and we have extended this treatment to arteriosclerotic aneurysms. DR. SURESH C. GHOSH Philadelphia. Pa.
I would like to share with you our experience at the Medical College of Pennsylvania and the Albert Einstein Medical College Northern Division in Philadelphia, Pennsylvania. We are using a new prosthesis called the "intraluminal ringed shunt," which is similar to the prosthesis to which Dr. Lemole has already alluded. We started in late 1974, and our first operation was performed in July, 1975. We published six
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case reports in the Association journal in September, 1975. The description of the device is as follows: It was a stainless steel ring, 10 mm wide and I mm thick with an external groove 5 mm deep. The internal diameter ranged from 18 to 15 mm. A Dacron graft of corresponding size was inserted through the rings, folded over, and sutured back into the graft, so that there were two cloth-covered rings at both ends of the tubular graft. The length of the graft was variable. Subsequently, this was made by USCI, and it is available with an outside diameter from 20 to 34 mm and with 4, 6, and 8 cm Dacron tubes. The rings are made of radiopaque rigid polypropylene. This device can be used in the treatment of type I and type III dissections of the thoracic aorta. The actual technique of insertion is simple. After total cardiopulmonary bypass, the aorta is opened and the dissection is identified. Three pledget-supported sutures are used to secure the ring, proximally and distally. The arota is tied over the rigid rings with a tape of any heavy, strong suture material. Finally, the diseased aorta is sutured over the graft. In cases in which there is aortic regurgitation but the aortic valve is normal, the valve can be suspended with pledget-supported sutures through the commissures without replacing the aortic valve. Sometimes the graft can be longer than the aorta. In such a case, the graft can be divided, trimmed, and fashioned to proper size. The basic purpose of this discussion is to avoid suture lines, because there is significant bleeding from suture
Thoracic and Cardiovascular Surgery
lines in the usual graft replacement in dissection of thoracic aorta. I am very happy to report that our long-time survival is more than 5 years. DR. CAR PEN TIE R (Closing) I would like to thank the discussers. There were two comments on techniques for reducing bleeding problems associated with partial resection and replacement of the aorta. We have found these techniques unsatisfactory in type I and type II aortic dissections because the coronary arteries prevent securing the graft close to the aortic anulus, thus leaving in place the dissected sinuses of Valsalva. Bypass grafting between the ascending aorta and the abdominal aorta is not a new operation. It was actually performed for the first time by Shumacker in 1966 in this country. The proposed approach is different, in that its aim is to treat the aortic dissection during the acute phase, before a chronic aneurysm is constituted and early enough to restore the blood flow in the true lumen. As aortic dissection is a disease involving the entire aorta, we do not expect to eliminate all of the complications. However, we have found the mortality and morbidity to be much less frequent with this technique than with the current techniques. This was a preliminary report, and we need more time to see if the initial good results hold with time in order to confirm the value of this concept.
THoRAc CARDIOV ASC
S URG 81 :659-668, 1981
Original Communications
New surgical approach to aortic dissection: Flow reversal and thromboexclusion With the aim or decreasing the complications and mortality associated with the current techniques for aortic dissections, \I'e have developed an operation which consists or bypassing the dissected aorta and creating fiow reversal in the dissected segment, Seven patients with either acute (five} or chronic aortic dissections (two) \I'ere operated upon success/idly, with no early or late deaths. Three transient postoperative complications \1'1'1'1' encountered: loll' cardiac output, hemiparesis, and renal insufficiency, Postoperative arteriography \I'as performed in five patients and demonstrated exclusion or the dissected lesions by thrombosisfollowing jiow reversal in the descending aorta, Follow-up is available from 2 to 28 months (average 13 months). with 110 long-term complications,
A, Carpentier, M,D, (by invitation), A, Deloche, M,D, (by invitation), J. N. Fabiani, M.D. (by invitation), S. Chauvaud, M.D. (by invitation), J. Reiland, M.D. (by invitation), R. Nottin, M,D. (by invitation), P. Vouhe , M.D. (by invitation), H. Massoud, M.D. (by invitation), and Ch. Dubost, M.D., Paris, France
Aortic dissection continues to be associated with a high incidence of early and late mortality despite continued progress in surgical technique and myocardial protection. The various factors responsible for this poor prognosis have been examined both experimentally and clinically, and a technique has been developed to overcome the most frequent complications: bleeding, suture line dehiscence, recurrent dissection, rupture, and ischemia.
Concept of thromboexclusion by blood flow reversal in the descending aorta Most of the complications associated with the currently used operations for aortic dissection result from From Laboratoire d 'Etudes des Protheses Cardfaques-c. N.R. S., and Association Claude Bemard-H6pital Broussais, Paris, France. Read at the Sixtieth Annual Meeting of The American Association for Thoracic Surgery, San Francisco, Calif., April 28 to 30, 1980. Address for reprints: Alain Carpentier, M.D" H6pital Broussais, 96 rue Didot, 750l4-Paris, France,
the following two factors: The anastomotic sutures to the Dacron graft are placed in the dissected aorta, which may lead to hemorrhage or suture line disruption because of the fragility of the tissues. The resection of the dissected aorta is limited and a large dissected portion is left in place, so that the potential remains for recurrent dissection, rupture, or ischemia in the postoperative course. Our efforts were directed toward an operation that would avoid sutures in the dissected areas and effectively correct the lesions. This was to be achieved by reversing the flow in the dissected aorta and producing subsequent thrombosis and exclusion of the lesions (Fig. 1). This technique is based on the following principles: Arterial reconstruction is accomplished by an aortoaortic bypass graft that is sutured to the nondissected areas of the aorta and thereby avoids the dissected aorta. A permanent clamp placed at the upper limit of the dissection effectively reverses the flow in the descending aorta. Blood flow in the true lumen is partially restored and the size and extent of the false lumen is reduced. The stagnating blood thromboses in the false
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Fig. 1. Concept of flow reversal and thromboexclusion of aortic dissection. I, A Dacron graft is placed so as to bypass the dissected aorta. 2, A permanent clamp is placedat the upper limit of the dissection.3, Flow reversal in the descending aorta restores blood flow in the true lumen and reduces the size and extent of the false lumen. 4, Thrombosis in the false lumen and in the segment of the aorta devoid of major branches. lumen and in the segment of the descending aorta devoid of major branches. The progressive nature of the thrombosis allows for a period of circulatory adaptation of the spinal cord. The intra-aortic thrombosis spontaneously limits its distal extent to the major collateral branches of the aorta, the artery of Adamkiewicz, and the intra-abdominal branches.
were ligated. A specially designed permanent clamp* was subsequently placed distal to the proximal anastomosis of the bypass graft and proximal to the site of dissection (Fig. 2). Four dogs survived, and in all cases thrombosis occurred in the false lumen and the distal portion of the true lumen corresponding to the area of ligated intercostal branches.
Experimental evaluation
Clinical experience
Five mongrel dogs were operated upon by means of a left lateral thoracotomy through the sixth intercostal space. A 15 mm by 20 em Dacron bypass graft was sutured between the descending aorta distal to the subclavian artery and the supradiaphragmatic thoracic aorta. End-to-side anastomoses were constructed with continuous 4-0 Prolene sutures after a partial occlusion clamp had been applied to the aorta. Once the graft was in place and functioning, an aortic dissection was created. This was done by doubly cross-clamping and opening the aorta distal to the proximal anastomosis, by creating a cleavage of the media of the aortic wall with a nerve hook, and by a circumferential partial excision of the inner layer. Following closure of the aorta, cross-clamps were released and blood flow restored to the dissected area. The first two pairs of intercostal branches distal to the site of experimental dissection
Between December, 1977, and February, 1980, seven patients having either acute dissection (five patients) or chronic dissection (two patients) were operated upon by means of the technique of blood flow reversal and thromboexclusion. The age of the patients ranged from 24 to 61 years, average 46 years. There were five men and two women. Four patients had severe hypertension prior to the operation (average blood pressure 220/140 mm Hg). Two displayed the typical features of Marfan 's syndrome and one had no previous medical history. Five patients were operated upon during the acute phase of the dissection, that is, 2, 10, 15, 15, and 20 days, respectively, after the onset of symptoms. There were two type I dissections and one type III dissection. The remaining two patients had *S.A.I.M.A.P. CO Paris.
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Fig. 2. Aortic clamps designed to cross-clamp the aorta permanently.
been previously operated upon for a type II and a type I aortic dissection with replacement of the aortic valve by a valvular bioprosthesis and replacement of the ascending aorta by a Dacron graft. Following the operation, both patients had an acute recurrent dissection of the descending aorta with a left hemothorax. Two patients were operated upon in the chronic phase of dissection, 4 and 10 months after the onset of the initial symptoms. Both of these patients had type III aortic dissections. Operative technique The technique varied depending on the extent of the lesions and the type of dissection. They were classified into four groups: 1. Type III aortic dissection (three patients). The technique did not require extracorporeal circulation and the entire operation was carried out through a median sternotomy and midline abdominal incision. The dissection involved the abdominal aorta in all cases. A nondissected segment of the abdominal aorta was selected which was, in all three cases, the distal portion of the abdominal aorta at the origin of the inferior mesenteric artery. A 22 mm woven USCI Dacron graft was preclotted by being coated with heparinized blood and then autoclaved according to the method of Bethea and Reemtsma.' The graft was implanted end to side after the aorta had been cross-clamped, opened, and the distal vascular bed had been protected from clotting by injection of a heparinized saline solution. After aortotomy, the edges of the aorta were reinforced externally and internally by two strips of Teflon felt sutured
together with the aortic wall in between. The anastomosis was then constructed with a continuous 4-0 Prolene suture. The prosthesis was placed in the retroperitoneum, then routed through the transverse mesocolon and the lesser sac to the diaphragm lateral to the left lobe of the liver. The graft was passed through the diaphragm anteriorly to the inferior vena cava. It was then positioned within the right pleural cavity lateral to the heart. The graft was passed through the pericardium at the level of the aorta. The ascending aorta was partially occluded laterally. End-to-side anastomosis was completed after the edges of the aorta had been reinforced by two strips of Teflon felt as previously described. A permanent clamp was placed across the aorta distal to the left subclavian artery. Adequate vascularization of the abdominal arteries was carefully noted before the sternum and the abdomen were closed. 2. Type I dissection (one patient) (Fig. 3). The procedure was done through a median sternotomy and midline abdominal incision. A 24 mm Dacron bypass graft was placed between the aortic root and the abdominal aorta. The distal anastomosis was performed distal to the renal arteries after the edges of the aorta had been reinforced by two strips of Teflon felt. The Dacron graft was positioned as previously described and brought up into the right pleural cavity. A 15 by 7 mm bifurcation graft was implanted end to side on the aortic Dacron graft for revascularization of the inominate and left carotid arteries. A third 8 mm Dacron graft was implanted on the bifurcation graft for revascularization of the left subclavian artery. The revascularization of these arteries was carried out without extracorporeal
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Fig. 3. Technique for type I aortic dissection. A. Lesions. B, Distal anastomosis to a nondissected segment of abdominal aorta. C. Revascularization of innominate, left carotid, and left subclavian arteries. D. Under extracorporeal circulation, aortic valve replacement and proximal anastomoses. E. Placement of permanent aortic clamp, flow reversal, and thromboexclusion.
Fig. 4. Technique for type I retrograde aortic dissection. A. Distal anastomosis to nondissected segment of abdominal aorta, B. Under extracorporeal circulation, opening, gluing, and reinforcing the ascending aorta. C. Proximal anastomosis. D. Permanent clamp on descending aorta, flow reversal, and thrornboexclusion.
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Fig. S. Technique for recurrent dissection after previous replacement of ascending aorta for type I dissection. A. Previous operation-replacement of aortic valve and ascending aorta. B. Recurrent dissection and rupture into the left pleura. C. Bypass graft between a nondissected segment of the abdominal aorta and the ascending aorta graft. Placement of permanent clamp, flow reversal, and thromboexclusion.
circulation by serial clamping of each vessel under continuous electroencephalographic monitoring. Extracorporeal circulation was then instituted with myocardial protection using a 4° C cardioplegic solution. The ascending aorta was opened. The aortic valve was replaced with a valvular bioprosthesis. As the sinuses of Valsalva were not extensively dissected, the proximal end of the Dacron aortic graft was sutured just above the commissures after the dissected lumina had been stuck together with a biologic glue* and the edges of the proximal aorta had been reinforced with two strips of Teflon felt. The anastomosis was carried out with a continuous 4-0 Prolene suture. A permanent clamp was placed on the distal portion of the ascending aorta. After discontinuation of bypass, adequate vascularization of the major abdominal branches was carefully checked. 3. Type I dissection with origin in the descending aorta (one patient) (Fig. 4). One 50-year-old male patient presented with an acute dissection and minimal aortic insufficiency. At angiography, the dissection was considered to be classical type I. At operation the ascending aorta was found to be dissected in a retrograde *Pharmacie Centrale, Hopital Henri Mondor, Paris, France.
fashion but not ruptured. A 22 mm Dacron graft was sutured to the abdominal aorta just above the bifurcation. Cardiopulmonary bypass was instituted. The ascending aorta was cross-clamped and opened by a right lateral longitudinal incision. As the true lumen had not ruptured and the aortic valve was intact, the aortic layers were approximated firmly together with a biologic glue. The edges of the aorta were further reinforced by two strips of Teflon felt. The proximal end of the bypass graft was then sutured to the aortotomy and a permanent clamp was placed across the aorta distal to the left subclavian artery. 4. Recurrent dissection after previous replacement of ascending aorta (two patients) (Fig. 5). One patient with a type I dissection and one patient with a type II dissection had previously undergone replacement of the ascending aorta according to the current technique of resection and prosthetic replacement. Three months and 12 days, respectively, after this first operation they had recurrent left chest pain and left hemothorax resulting from partial rupture of the descending aorta. This lesion was treated in both cases by flow reversal and thromboexclusion of the descending aorta. A 22 mm Dacron bypass graft was implanted between the abdominal aorta close to its bifurcation and
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Fig. 6. Roentgenograms of patient whose operation is diagrammed in Fig. 5. Left, Preoperative chest x-ray film showing recurrent dissection and left hemothorax. Right, Postoperative chest x-ray film showing complete resolution. Permanent aortic clamp is visible.
the right lateral side of the ascending aortic graft. This did not necessitate extracorporeal circulation. A permanent clamp was then placed across the aorta distal to the left subclavian artery. Even though the ruptured aorta was not treated directly and the hemothorax was not drained, the pain and the hemothorax disappeared completely in the postoperative period in both cases (Fig. 6).
Results All seven patients survived the operation. One patient with a type I dissection had a left hemiparesis which regressed completely within I month. One patient had transient low cardiac output and one had transient renal insufficiency. There were no neurologic complications suggestive of circulatory disturbances to the spinal cord. All patients displayed normal circulation of the lower extremities as assessed clinically and by ultrasonic Doppler technique. Postoperative blood pressures remained identical to the preoperative figures. Aortography was performed in five patients I month after the operation. All showed normal vascularization of the branches of the abdominal aorta and loss of the double contour image of the abdominal aortic lumen. The upper two thirds of the descending thoracic aorta was not filled by the contrast medium, and the intercostal vessels were visible at the junction between the opacified and nonopacified segments (Figs. 7 and 8). One patient with a type I dissection had a body scan combined with repeat intravenous dye injections I month after the operation, and these studies also showed the thrombosis of the lesion (Fig. 9). The patients were discharged from the hospital
without any medication, except for antihypertensive drugs in three patients. The long-term course of all of the patients has been uncomplicated thus far, with a follow-up of 2, 4, II, 13, 16, 18, and 28 months, respectively.
Discussion In the past 10 years, the treatment of aortic dissection" has benefited from successive improvements, among which the most significant have been resection and prosthetic replacement of a limited segment of the dissected aorta, medical treatment aimed at reducing hypertension, and finally the use of biologic glue'': ~ or a ringed intraluminal graft" 6 in order to reduce bleeding at the suture line. Nevertheless, the incidence of operative complications and early mortality remains high, averaging 20% to 50%. The incidence of late complications and late mortality remains even higher, 5% to 10% per patient-year. Actuarial survival at 8 years was recently reported to be 33% to 50% depending on the type of dissections. The technique presented in this paper was developed to improve results. 7-9 The main advantages of this operation are the following: The operation is performed through a single incision regardless of the types of dissection. This presents the unique advantage of diagnosing and treating a dissection which may evolve in an antegrade or retrograde fashion after angiography. The operation can be carried out without extracorporeal circulation in type III dissection and with a reduced bypass time in type I dissection, as the distal anatomoses are performed before bypass is established. The risk of disruption and hemorrhage is reduced, because the sutures are placed in the
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Fig. 7. Type III aortic dissection. Left. Preoperative angiogram. Right. Postoperative angiogram showing flow reversal in the descending aorta and thrombosis of the upper thoracic segment.
Fig. 8. Type I aortic dissection. Postoperative angiograms showing revascularization of innominate, left carotid, and left subclavian arteries (left), retrograde revascularization of abdominal vessels, and lack of opacification above the eleventh intercostal artery (right). nondissected areas of the aorta. If the sinuses of Valsalva and coronary ostia are dissected, the proximal end of the Dacron graft can be sutured to the aortic anulus with coronary revascularization. If the dissection does not extend to the sinuses of Valsalva, the proximal end of the Dacron graft is sutured at the level of the commissures. The latter is preferred in cases of limited
dissection, because sticking the two layers of dissected aorta together with biologic glue and reinforcing the aortic wall with strips of Teflon felt have proved to be effective and safe procedures. The distal anastomosis of the aortic graft is constructed in a nondissected segment of the distal aorta, which may be at the supradiaphragmatic or subdia-
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Fig. 9. Type I aortic dissection. Body scan I month following operation. A, Cut through pulmonary artery (p}, Aortic graft (g) anteriorly is fully opacified. Descending dissected aorta ida) posteriorly showing thrombosis of both false and true lumina. B, Cut through the heart. Aortic graft anteriorly is fully opacified. Descending aorta posteriorly showing true lumen partially opacified and false lumen completely thrombosed. C. Cut through the diaphragm. Aortic graft lateral to the heart is fully opacied. Descending aorta posteriorly showing true lumen fully opacified and false lumen thrombosed. D, Cut through the liver. Aortic graft is fully opacified. and abdominal aorta is fully opacified with no visible dissection.
phragmatic level; the supradiaphragmatic aorta can be approached after dividing the diaphragm, It is usually necessary to implant the distal end of the graft to the abdominal aorta close to its bifurcation. It may be necessary to go even further to the iliac arteries using a bifurcation graft. Flow reversal restores blood flow in the segment of the true lumen which has vital runoff and allows the false lumen to thrombose. The gradual nature of the thrombosis permits a period of adaptation for the spinal cord, as proved by our experience. Although no complications have been observed thus far in the follow-up period of these seven patients, the question as to whether or not these results will withstand time remains to be answered. The long aortic bypass graft per se, described by Shumacker and King.!" does not seem to have caused problems, Wei first utilized this technique in 1969 for cases of complicated coarctation of the aorta, and the first patient operated upon is still alive and well after II years, Since
then, there have been several similar reports of long aortic bypass grafts with excellent results .11* The operation proposed in this paper is indeed based upon a very different concept introducing new unknown hazards: the extent of the thrombosis, the fate of the dissected aorta, vascularization of the spinal cord, abdominal viscera, and the peripheral circulation. One would expect to encounter impaired vascularization of one or more abdominal branches such as the renal or mesenteric arteries after flow reversal. This could conceivably require additional revascularization off the main Dacron graft. The results obtained in this preliminary experience compare favorably with those obtained in our center in an earlier series of patients operated upon by previous techniques." It is therefore our present policy to use the proposed operation in type I and type III acute and chronic aortic dissections. *Brom G: Personal communication.
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Addendum Since this paper was submitted for publication, one additional patient with type III aortic dissection developed paraplegia 6 hours after operation. The patient was reoperated upon immediately, and it was verified that thrombosis had not occurred in the distal segment of the aorta. This complication could have been due to an extension of the dissection before the onset of thrombosis. For technical reasons, the left subclavian artery was clamped during the first operation, and this may have been a contributory factor to this complication. All the patients described in this study continue to do well without complications.
We wish to gratefully acknowledge Dr. Stephen Colvin for help in reviewing the manuscript and Miss Christiane Veneziani for her valuable technical assistance. REFERENCES Bethea MC, Reemtsma K: Graft hemostasis. An alternative to preclotting. Ann Thorac Surg 27:374, 1979 2 De Bakey ME, Henly WS, Cooley DA, Morris GC Jr, Crawford ES, Beall AC Jr: Surgical management of dissecting aneurysms of the aorta. J THORAC CARDIOVASC SURG 49:130-149, 1965 3 Guilmet 0, Liebeaux M, Dhainaut JF, Goudot B, Francoual M, Bachet J: Traitement chirurgical des dissections aigues de laorte ascendante. Arch Mal Coeur 70:639-
644, 1977 4 Wolfe WG, Moran JF: The evolution of medical and surgical management of acute aortic dissection. Circulation
56:503-505, 1977 5 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 76:390-396, 1978 6 Dureau G, Villard 1, George M, Deliry P, Froment JC, Clermont A: New surgical technique for the operative management of acute dissections of the ascending aorta. J THORAC CARDIOVASC SURG 76:385-389, 1978 7 Carpentier A, Guilmet 0, Prigent CI, Gandjbakhch I, Deloche A, Lessana A, Farge CI, Tricot J, Morillo F, Dubost Ch: Aneurysms of the aortic arch, Eighteenth Congress of German Society of Thoracic Surgery, Bad Nauheim, 1969, Thoraxchirurgie Vaski.ilare Chirurgie, Vol 19, Part 5, October, 1971 8 Carpentier A: Dissections aigues de I'aorte , Actualites de chirurgie cardiovasculaire de I'Hopital Broussais, Ch Dubost, A Carpentier, eds., Paris, 1979, Masson & Cie 9 Carpentier A: A new approach to the treatment of aortic dissections. Lancet 2: 1291, 1979 10 Shumacker HB Jr. King H: Surgical management of rapidly expanding intrathoracic pulsating hematomas. Surg Gynecol Obstet 109: 155-164, 1959 II Frantz SL, Kaplin MJ: An alternate operative approach
for the highly diseased abdominal aorta. Cardiovasc Dis Bull Texas Heart Inst 1:1974 12 Anagnostopoulos EE: Acute aortic dissection. Baltimore, 1975, University Park Press 13 Dubost Ch , Guilmet 0, Soyer R: Les anevrysmes de laorte , Paris, 1971, Masson & Cie
Discussion DR. GERALD M. LEMOLE Philadelphia, Pa.
Since 1974, Dr. Strong, Dr. Spagna, and I have been working with a rigid steel spooled Dacron graft placed inside the lumen of the dissector above and below the tear. It was held in place by a strip of Dacron felt. The first five patients were treated by means of this method. However, we had to make these grafts by hand. For convenience sake we began using the USCI manufactured rigid polypropylene spool and a Dacron umbilical tape, although I am not sure whether or not this tape will have a tourniquet effect. We did our first case in 1976 and we have done nine cases since then. Five of these were type I dissections and four were type Ill. There were seven acute and two chronic cases. Of the five patients with type I dissections, two required valves and one required quadruple coronary bypass. Cross-clamp time averaged less than an hour. The pump time and blood usage were approximately one third of what we normally had required prior to this. There were no intraoperative deaths. There was one death in the postoperative third week caused by massive gastrointestinal hemorrhage in a patient who was posted and whose prosthesis was functioning well. Another patient died at 7 months of an infected graft and empyema. We have a 4 year follow-up on these cases. [Slide] This slide shows the first case that was done in 1976. At follow-up 3 years after implantation, the graft was in good position and the continuity of the vessel was proper. Three months ago we had a case in which the cardiologists could not decide whether the patient had an acute dissector or preinfarction angina. As it turned out, both diagnoses were right. He had a false lumen with a tear and left main lesion, an occluded marginal artery, and an occluded right coronary artery. We did an interposition and a triple saphenous vein bypass graft with an internal mammary artery grafted to the anterior descending. Postoperative films show the graft in place and a nuclear scan shows a 60% ejection fraction, We feel that this is the therapy of choice in our hands and we have extended this treatment to arteriosclerotic aneurysms. DR. SURESH C. GHOSH Philadelphia. Pa.
I would like to share with you our experience at the Medical College of Pennsylvania and the Albert Einstein Medical College Northern Division in Philadelphia, Pennsylvania. We are using a new prosthesis called the "intraluminal ringed shunt," which is similar to the prosthesis to which Dr. Lemole has already alluded. We started in late 1974, and our first operation was performed in July, 1975. We published six
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case reports in the Association journal in September, 1975. The description of the device is as follows: It was a stainless steel ring, 10 mm wide and I mm thick with an external groove 5 mm deep. The internal diameter ranged from 18 to 15 mm. A Dacron graft of corresponding size was inserted through the rings, folded over, and sutured back into the graft, so that there were two cloth-covered rings at both ends of the tubular graft. The length of the graft was variable. Subsequently, this was made by USCI, and it is available with an outside diameter from 20 to 34 mm and with 4, 6, and 8 cm Dacron tubes. The rings are made of radiopaque rigid polypropylene. This device can be used in the treatment of type I and type III dissections of the thoracic aorta. The actual technique of insertion is simple. After total cardiopulmonary bypass, the aorta is opened and the dissection is identified. Three pledget-supported sutures are used to secure the ring, proximally and distally. The arota is tied over the rigid rings with a tape of any heavy, strong suture material. Finally, the diseased aorta is sutured over the graft. In cases in which there is aortic regurgitation but the aortic valve is normal, the valve can be suspended with pledget-supported sutures through the commissures without replacing the aortic valve. Sometimes the graft can be longer than the aorta. In such a case, the graft can be divided, trimmed, and fashioned to proper size. The basic purpose of this discussion is to avoid suture lines, because there is significant bleeding from suture
Thoracic and Cardiovascular Surgery
lines in the usual graft replacement in dissection of thoracic aorta. I am very happy to report that our long-time survival is more than 5 years. DR. CAR PEN TIE R (Closing) I would like to thank the discussers. There were two comments on techniques for reducing bleeding problems associated with partial resection and replacement of the aorta. We have found these techniques unsatisfactory in type I and type II aortic dissections because the coronary arteries prevent securing the graft close to the aortic anulus, thus leaving in place the dissected sinuses of Valsalva. Bypass grafting between the ascending aorta and the abdominal aorta is not a new operation. It was actually performed for the first time by Shumacker in 1966 in this country. The proposed approach is different, in that its aim is to treat the aortic dissection during the acute phase, before a chronic aneurysm is constituted and early enough to restore the blood flow in the true lumen. As aortic dissection is a disease involving the entire aorta, we do not expect to eliminate all of the complications. However, we have found the mortality and morbidity to be much less frequent with this technique than with the current techniques. This was a preliminary report, and we need more time to see if the initial good results hold with time in order to confirm the value of this concept.