Ann Thorac Surg 1999;68:1860-1863
© 1999 The Society of Thoracic Surgeons
Case Reports
Enlargement of ulcer-like projections after repair of acute type A aortic dissection
Tokuo Koshino, MDa,
Kiyofumi Morishita, MD, PhDa,
Yukihiko Tamiya, MDa,
Johji Fukada, MDa,
Tomio Abe, MD, PhDa
a Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
Address reprint requests to Dr Koshino, Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo 060-8543, Japan
e-mail: tokuo{at}serpent.cc.sapmed.ac.jp
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Abstract
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We treated two cases of enlargement of ulcer-like projections in the descending thoracic aorta, which were recognized after emergency graft replacement from the ascending aorta to the aortic arch for acute type A aortic dissection. The intimal tear, which was near the left subclavian artery, was resected during the initial operation. Graft replacement of the descending thoracic aorta was successful.
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Introduction
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The Stanford classification has been used recently for aortic dissection [1]. Type A dissection contains two types, antegrade dissection and retrograde dissection. Kazui and colleagues [2] proposed the latter dissection as "type A dissection with the tear in the descending aorta"; ie, the intimal tear exists just distal to the left subclavian artery and the dissection extends in a retrograde manner to the ascending aorta. We recognized the enlargement of residual tears in the descending thoracic aorta after a graft replacement for acute type A dissection with the tear in the descending aorta.
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Case reports
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Patient 1
A 65-year-old woman with a complaint of chest and back pain was transferred to our hospital. Enhanced computed tomographic scan showed broad dissection from the ascending aorta to the abdominal aorta and the patent false lumen in the ascending aorta. The visceral branches emerged from the true lumen. Emergency graft replacement of the ascending aorta to the aortic arch was done.
The heart, ascending aorta, aortic arch, and arch vessels were exposed through median sternotomy. The ascending aorta was cross-clamped and transected above the orifices of the coronary arteries. Gelatin-resorcinol-formol glue was used for proximal aortic stump plasty. When the rectal temperature was 21°C, selective cerebral perfusion was started. The descending aorta was transected completely distal to the left subclavian artery. The intimal tear existed just distal to the left subclavian artery. Gelatin-resorcinol-formol glue was used for distal aortic stump plasty. A four-limbed arch graft was sutured to the stump of the descending thoracic aorta. Subsequently, the left subclavian artery was sutured to a side limb of the graft. Antegrade systemic circulation was started through the fourth limb. The proximal graft, the innominate artery, and the left carotid artery were anastomosed. Enhanced computed tomographic scan performed 1 month after the operation showed thrombosed occlusion of the false lumen. However, intra-aortic digital subtraction angiography conducted 8 months after the operation showed multiple ulcer-like projections (ULPs) in the descending thoracic aorta (Fig 1).
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Fig 1. (A) Digital subtraction angiogram taken after the first operation showed multiple ulcer-like projections in the descending thoracic aorta in case 1. (B) Diagram of operative technique.
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A reoperation was done by left thoracotomy. When the left pleural cavity was opened, a dilated descending thoracic aorta was observed. Both the previously implanted arch graft and the descending thoracic aorta above the diaphragm were cross-clamped and cut open. There were four ULPs in the descending thoracic aorta. A woven Dacron graft was anastomosed to the distal end of arch graft previously implanted. The distal site of the graft was anastomosed to the descending aorta just above the diaphragm. The postoperative course was uneventful, and postoperative intraaortic digital subtraction angiography showed excellent reconstruction of the thoracic aorta.
Patient 2
A 75-year-old man was admitted because he had a sudden onset of chest and back pain and subsequently lost consciousness. Enhanced computed tomographic scan showed acute Stanford type A aortic dissection with cardiac tamponade. The false lumen was thrombosed, and visceral branches emerged from the true lumen. Urgent operation was done. The surgical procedures and techniques used were the same as for case 1. The intimal tear existed just distal to the left subclavian artery and was resected. Postoperative enhanced computed tomographic scan showed thrombosed occlusion of the distal false lumen. During follow-up, an abnormal shadow near the descending aorta was recognized in a chest roentgenogram. Intra-aortic digital subtraction angiography performed 6 months after the operation showed a giant ULP in the descending aorta (Fig 2). For reoperation the same procedure was used. The giant ULP existed distal to the previous suture line. Intraaortic digital subtraction angiography done after the second operation showed satisfactory reconstruction of the descending aorta.
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Fig 2. (A) Digital subtraction angiogram taken after the first operation showed a large ulcer-like projection in the descending thoracic aorta in case 2. (B) Diagram of operative technique.
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Comment
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There has been remarkable improvement in the surgical results for acute type A aortic dissection because of the progress in surgical techniques and adjuncts. In acute type A aortic dissection, there are a few cases where the intimal tear is not located in the ascending aorta or aortic arch. In such cases, the intimal tear often is recognized in the descending thoracic aorta near the left subclavian artery, and the dissection extends in a retrograde manner to the ascending aorta. Kazui and associates [2] termed this type of dissection "acute type A dissection with the tear in the descending thoracic aorta." Although preoperative determination of type A dissection is difficult, we think that it is not of critical importance to decide the portion of the intimal tear preoperatively because the surgical procedure for type A dissection, whether it is an antegrade dissection or retrograde dissection, is always done through a median sternotomy with appropriate cerebral protection. Therefore, a distinction between antegrade dissection and retrograde dissection can be made intraoperatively. When the intimal tear does not exist in the ascending aorta or aortic arch, inspection of the descending aorta around the left subclavian artery is necessary, and resection of the intimal tear should be done.
Because of the improved results of selective cerebral perfusion [3], graft replacement of the aortic arch as well as the ascending aorta for type A dissection is recommended. In this procedure, the intimal tear should be resected near the left subclavian artery. There remains the possibility of a residual intimal tear in the descending thoracic aorta, which could increase gradually during postoperative period. We suspect that the patients described herein had multiple intimal tears, because the intimal tear that existed just distal to the left subclavian artery was resected during the initial operation. According to Tisnado and associates [4], the appearance of ULPs in the aortogram indicate a possible rupture, so surgical treatment should be done as early as possible.
Recently, endovascular stent-graft placement has been a good therapeutic option for aortic aneurysms. In 1994, Dake and colleagues [5] reported the feasibility of endovascular stent-grafts for descending thoracic aneurysms. Mitchell and coworkers [6] reported good results using that technique. Stent-graft placement might be beneficial to high-risk patients because it is less invasive than conventional surgical methods. Technically, this procedure should be limited to patients with a sufficient distal and proximal neck. Patients with enlargement of ULPs in the descending thoracic aorta might be good candidates for stent-graft placement.
In the treatment of acute type A dissection with the tear in the descending aorta, when graft replacement of the aortic arch as well as the ascending aorta has been done, the intimal tear located near the left subclavian artery should be resected as much as possible. In regions more distal to the distal anastomotic site in the descending aorta, residual intimal tears, which might not be seen through a median sternotomy, might exist, as in our cases. Therefore, to prevent residual ULPs from forming aneurysms and rupturing, postoperative angiography should be scheduled early after the initial operation. If evidence of ULPs is found, further surgical treatment must be done as soon as possible.
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References
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Daily P.O., Trueblood H.W., Stinson E.B., Wuerflein R.D., Shumway N.E. Management of acute aortic dissections. Ann Thorac Surg 1970;10:237-247.[Free Full Text]
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Kazui T., Tamiya Y., Tanaka T., Komatsu S. Extended aortic replacement for acute type A dissection with the tear in the descending aorta. J Thorac Cardiovasc Surg 1996;112:973-978.[Abstract/Free Full Text]
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Kazui T., Kimura N., Komatsu S. Surgical treatment of aortic arch aneurysms using selective cerebral perfusion. Experience with 100 patients. Eur J Cardiothorac Surg 1995;9:491-495.[Abstract/Free Full Text]
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Tisnado J., Cho S.R., Beachley M.C., Vines F.S. Ulcerlike projections. Am J Roentgenol 1980;135:719-722.[Abstract]
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Dake M.D., Miller D.C., Semba C.P., Mitchell R.S., Walker P.J., Liddell R.P. Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994;331:1729-1734.[Medline]
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Mitchell R.S., Dake M.D., Semba C.P., et al. Endovascular stent-graft repair of thoracic aortic aneurysms. J Thorac Cardiovasc Surg 1996;111:1054-1062.[Abstract/Free Full Text]
Accepted for publication April 22, 1999.
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Abstract
Introduction
