Mycotic Aneurysm of the Ascending Aorta Following Coronary Revascularhation Ivan K . Crosby, F.R.C.S., and Charles Tegtmeyer, M.D. ABSTRACT A large mycotic aneurysm of the ascending aorta that appeared two years, three months after triple coronary revascularization is described. Hypothermia and total circulatory arrest were used in excising the aneurysm, and sterilization of the mediastinum was achieved with systemic and local antibiotic therapy. Follow-up at eight months showed a satisfactory postoperative course and no recurrence of mediastid infection.
Coronary artery revascularization has undergone progressive refinement and simplification over the last ten years, and careful attention to surgical technique and postoperative management'has reduced the incidence of mortality and perioperative morbidity. However, long-term follow-up of the revascularized patient is essential in evaluating the true benefits of the procedure as well as in unmasking some uncommon late complications of this popular operative procedure. Documented late vascular complications following coronary revascularization include graft thrombosis, subintimal hyperplasia of the venous conduit, and aneurysmal dilatation of the aortic anastomosis of the vein graft, which has been attributed to suture fragmentation [ll. Koch is usually credited with the original pathological description of a mycotic aneurysm in a patient with bacterial endocarditis, but the term malignant endocarditis was introduced by Osler 151 in 1885 to denote aneurysms resulting from an infectious process involving the arterial wall. Such mycotic aneurysms, involving any section of the arterial tree secondary to generalized septicemia, have been documented clinically and arteriographically [2, 4, 61. However, mycotic aneurysms of the ascending aorta as a complication of coronary artery revasculariFrom the Departments of Surgery and Radiology, University of Virginia Medical Center, Charlottesville, VA. Accepted for publication Sept 6, 1977. Address reprint requests to Dr. Crosby, Box 181, Department of Surgery, University of Virginia Medical Center, Charlottesville, VA 22901. 474 0003-497517810025-0519$1.00 @ 1978 by Ivan K. Crosby
zation are very unusual. The purpose of this paper is to illustrate such a problem and describe its satisfactory management. In July, 1974, a 50-year-old man underwent a triple-vessel revascularization for severe hypokinesis of his left ventricle and critical triple-vessel occlusive disease. His operative procedure was uneventful, and two days later he was back in his room, where he refused all pulmonary toilet and physical therapy and immediately commenced smoking cigarettes. He had copious secretions, which he handled ineffectively. Over the next several days his chest radiograph showed severe bilateral lower lobe atelectasis, and he developed serous drainage from the lower end of his sternotomy incision. It was necessary to reclose his sternum on the tenth postoperative day. There was no evidence of gross infection, and the mediastinum was irrigated copiously with antibiotic solution. The sternum was closed with mattress sutures of stainless steel wire, and the retrosternal space was drained. He was discharged from the hospital twelve days after the second operation. In October, 1976, two years, three months after the initial procedure, he was seen at his local hospital with a large mass protruding over the upper end of his sternum. The mass was thought to be an abscess. A small incision was made in the skin over the mass to establish drainage, but the procedure was discontinued because the mass was pulsatile. The patient sustained a major cerebrovascular accident at that time and was transferred to the University of Virginia Medical Center. Physical examination revealed a febrile, conscious, but incoherent man with severe right hemiplegia. A large, pulsating mass was present at the upper end of his sternum, and arteriography demonstrated a large false aneurysm arising from the ascending aorta just distal to the proximal graft anastomoses (Figure) and pouching up over the manubrium. All his coronary
475 Case Report: Crosby and Tegtmeyer: Mycotic Aneurysm of the Ascending Aorta
A
B
The ascending aorta in the area of the defect could have been excluded by the creation of a double-outlet left ventricle, using a valved conduit from the apex of the left ventricle to the thoracic or abdominal aorta and oversewing the ascending aorta immediately distal to the proximal graft anastomoses. However, we elected to close the 1.5 an defect using a monofilament, nonabsorbable suture in order to avoid incorgrafts were patent. He was immediately taken to porating a prosthetic vascular conduit in the the operating room where, under general anes- presence of obvious septicemia. During total thesia, the femoral artery and vein were cannu- circulatory arrest the defect was closed with lated and partial cardiopulmonary bypass was 3-0 Prolene sutures. While the patient was recommenced, with a steady arterial pressure of 80 warmed, the walls of the false mycotic aneurysm mm Hg, while he was gradually cooled to 23°C. were excised and mediastinal antibiotic irrigaWhen he went into spontaneous ventricular fib- tion catheters were introduced through the left rillation, he was promptly exsanguinated into hemithorax to irrigate the upper and lower the cardiotomy reservoir. Utilizing total cir- mediastinal areas. Drainage tubes were inserted culatory arrest, the sternum was opened, the in the retrosternum and left hemithorax. The aneurysm entered, and the defect in the ascend- sternotomy incision, which showed no evidence ing aorta readily seen and occluded with a of osteomyelitis, was then closed in the routine finger. The opening was 1.5 cm in diameter at fashion. The two periods of circulatory arrest the site of the previous arterial perfusion can- lasted seven minutes in all, and the patient was nula. With digital occlusion of the opening, car- transfused with a total of two units of blood diopulmonary bypass was instituted and the during the entire operative procedure. mycotic aneurysm was debrided. The entire Postoperatively, bacteriological evaluation mediastinum and pericardial cavity were oblit- showed gram-negative rods, gram-positive erated by dense, mature fibrous adhesions. cocci, and anaerobic gram-negative rods grow-
(A)Ascending aortogram in the lateral projection shows all three vein grafts to be patent. Arrows indicate the central lumen of the mycotic aneurysm; the dotted line, the external capsule protruding superiorly over the sternal wires. Radiopaque circles and metallic clips indicate the proximal graft anastomoses below the lumen of the false mycotic aneurysm. (B)The oblique projection shows the multiloculated pseudoaneuysm (arrows),distal to the proximal graft anastomoses.
476 The Annals of Thoracic Surgery
Vol 25 No 5 May 1978
ing from the mediastinal abscess wall. Because the cultures grew enterobacteria, the patient was treated with a combination of multiple systemic antibiotics and local antibiotic irrigation. There was steady improvement in his neurological status, and at the time of his discharge from the hospital six weeks after the operation, he was afebrile and ambulatory and had a normal white blood count. Serial chest radiographs showed progressive reduction in the diameter of his mediastinal cavity. Follow-up at eight months showed little residuum of the septic embolus to his brain and no evidence of recurrent mediastinal infection. Comment Following his original coronary revascularization in 1974, the patient developed an enterobacterial pulmonary infection. The presence of enterobacteria in the mycotic mediastinal aneurysm seems a logical sequel to his earlier pulmonary infection. The septic embolus to his dominant hemisphere was carefully monitored by brain scans and serial white blood counts, and responded well to prolonged systemic antibiotics. With the expanding aneurysm protruding over the upper end of his sternum, it was impossible to reopen the sternum without rup-
turing the mycotic aneurysm. The technique of profound hypothermia and total circulatory arrest facilitated surgical exposure of the lesion and minimized blood loss. The oversewing of the aortic defect with a monofilament suture, excision of the abscess wall, and local antibiotic irrigation of the mediastinum obviated insertion of additional prosthetic material and have, thus far, yielded a satisfactory early postoperative result. Long-term follow-up is necessary to evaluate the adequacy of this approach. References 1. Baltaxe HE, Levin DC: Angiographic demonstration of complications related to the saphenous aorta-coronary bypass procedure. Am J Roentgenol Radium Ther Nucl Med 119:484, 1973 2. Clark RE, Jacobson AC, Petty WE: Intrarenal mycotic (false) aneurysm secondary to staphylococcal septicemia. Radiology 115:421, 1975 3. Crosby IK, Killen DA, Shaikh AN, et al: Operative risk in coronary revascularization of patients with ventricular dysfunction. Am J Surg 128:746, 1974 4. Kahn PC: Iatrogenic diseasesof the arteries. Semin Roentgenol 5:284, 1970 5. Osler W: Gulstonian lectures on malignant endocarditis. Br Med J 1:467, 1885 6. Weintraub RA, Abrams HL: Mycotic aneurysms. Am J Roentgenol Radium Ther Nucl Med 102:354, 1968
Coronary artery revascularization has undergone progressive refinement and simplification over the last ten years, and careful attention to surgical technique and postoperative management'has reduced the incidence of mortality and perioperative morbidity. However, long-term follow-up of the revascularized patient is essential in evaluating the true benefits of the procedure as well as in unmasking some uncommon late complications of this popular operative procedure. Documented late vascular complications following coronary revascularization include graft thrombosis, subintimal hyperplasia of the venous conduit, and aneurysmal dilatation of the aortic anastomosis of the vein graft, which has been attributed to suture fragmentation [ll. Koch is usually credited with the original pathological description of a mycotic aneurysm in a patient with bacterial endocarditis, but the term malignant endocarditis was introduced by Osler 151 in 1885 to denote aneurysms resulting from an infectious process involving the arterial wall. Such mycotic aneurysms, involving any section of the arterial tree secondary to generalized septicemia, have been documented clinically and arteriographically [2, 4, 61. However, mycotic aneurysms of the ascending aorta as a complication of coronary artery revasculariFrom the Departments of Surgery and Radiology, University of Virginia Medical Center, Charlottesville, VA. Accepted for publication Sept 6, 1977. Address reprint requests to Dr. Crosby, Box 181, Department of Surgery, University of Virginia Medical Center, Charlottesville, VA 22901. 474 0003-497517810025-0519$1.00 @ 1978 by Ivan K. Crosby
zation are very unusual. The purpose of this paper is to illustrate such a problem and describe its satisfactory management. In July, 1974, a 50-year-old man underwent a triple-vessel revascularization for severe hypokinesis of his left ventricle and critical triple-vessel occlusive disease. His operative procedure was uneventful, and two days later he was back in his room, where he refused all pulmonary toilet and physical therapy and immediately commenced smoking cigarettes. He had copious secretions, which he handled ineffectively. Over the next several days his chest radiograph showed severe bilateral lower lobe atelectasis, and he developed serous drainage from the lower end of his sternotomy incision. It was necessary to reclose his sternum on the tenth postoperative day. There was no evidence of gross infection, and the mediastinum was irrigated copiously with antibiotic solution. The sternum was closed with mattress sutures of stainless steel wire, and the retrosternal space was drained. He was discharged from the hospital twelve days after the second operation. In October, 1976, two years, three months after the initial procedure, he was seen at his local hospital with a large mass protruding over the upper end of his sternum. The mass was thought to be an abscess. A small incision was made in the skin over the mass to establish drainage, but the procedure was discontinued because the mass was pulsatile. The patient sustained a major cerebrovascular accident at that time and was transferred to the University of Virginia Medical Center. Physical examination revealed a febrile, conscious, but incoherent man with severe right hemiplegia. A large, pulsating mass was present at the upper end of his sternum, and arteriography demonstrated a large false aneurysm arising from the ascending aorta just distal to the proximal graft anastomoses (Figure) and pouching up over the manubrium. All his coronary
475 Case Report: Crosby and Tegtmeyer: Mycotic Aneurysm of the Ascending Aorta
A
B
The ascending aorta in the area of the defect could have been excluded by the creation of a double-outlet left ventricle, using a valved conduit from the apex of the left ventricle to the thoracic or abdominal aorta and oversewing the ascending aorta immediately distal to the proximal graft anastomoses. However, we elected to close the 1.5 an defect using a monofilament, nonabsorbable suture in order to avoid incorgrafts were patent. He was immediately taken to porating a prosthetic vascular conduit in the the operating room where, under general anes- presence of obvious septicemia. During total thesia, the femoral artery and vein were cannu- circulatory arrest the defect was closed with lated and partial cardiopulmonary bypass was 3-0 Prolene sutures. While the patient was recommenced, with a steady arterial pressure of 80 warmed, the walls of the false mycotic aneurysm mm Hg, while he was gradually cooled to 23°C. were excised and mediastinal antibiotic irrigaWhen he went into spontaneous ventricular fib- tion catheters were introduced through the left rillation, he was promptly exsanguinated into hemithorax to irrigate the upper and lower the cardiotomy reservoir. Utilizing total cir- mediastinal areas. Drainage tubes were inserted culatory arrest, the sternum was opened, the in the retrosternum and left hemithorax. The aneurysm entered, and the defect in the ascend- sternotomy incision, which showed no evidence ing aorta readily seen and occluded with a of osteomyelitis, was then closed in the routine finger. The opening was 1.5 cm in diameter at fashion. The two periods of circulatory arrest the site of the previous arterial perfusion can- lasted seven minutes in all, and the patient was nula. With digital occlusion of the opening, car- transfused with a total of two units of blood diopulmonary bypass was instituted and the during the entire operative procedure. mycotic aneurysm was debrided. The entire Postoperatively, bacteriological evaluation mediastinum and pericardial cavity were oblit- showed gram-negative rods, gram-positive erated by dense, mature fibrous adhesions. cocci, and anaerobic gram-negative rods grow-
(A)Ascending aortogram in the lateral projection shows all three vein grafts to be patent. Arrows indicate the central lumen of the mycotic aneurysm; the dotted line, the external capsule protruding superiorly over the sternal wires. Radiopaque circles and metallic clips indicate the proximal graft anastomoses below the lumen of the false mycotic aneurysm. (B)The oblique projection shows the multiloculated pseudoaneuysm (arrows),distal to the proximal graft anastomoses.
476 The Annals of Thoracic Surgery
Vol 25 No 5 May 1978
ing from the mediastinal abscess wall. Because the cultures grew enterobacteria, the patient was treated with a combination of multiple systemic antibiotics and local antibiotic irrigation. There was steady improvement in his neurological status, and at the time of his discharge from the hospital six weeks after the operation, he was afebrile and ambulatory and had a normal white blood count. Serial chest radiographs showed progressive reduction in the diameter of his mediastinal cavity. Follow-up at eight months showed little residuum of the septic embolus to his brain and no evidence of recurrent mediastinal infection. Comment Following his original coronary revascularization in 1974, the patient developed an enterobacterial pulmonary infection. The presence of enterobacteria in the mycotic mediastinal aneurysm seems a logical sequel to his earlier pulmonary infection. The septic embolus to his dominant hemisphere was carefully monitored by brain scans and serial white blood counts, and responded well to prolonged systemic antibiotics. With the expanding aneurysm protruding over the upper end of his sternum, it was impossible to reopen the sternum without rup-
turing the mycotic aneurysm. The technique of profound hypothermia and total circulatory arrest facilitated surgical exposure of the lesion and minimized blood loss. The oversewing of the aortic defect with a monofilament suture, excision of the abscess wall, and local antibiotic irrigation of the mediastinum obviated insertion of additional prosthetic material and have, thus far, yielded a satisfactory early postoperative result. Long-term follow-up is necessary to evaluate the adequacy of this approach. References 1. Baltaxe HE, Levin DC: Angiographic demonstration of complications related to the saphenous aorta-coronary bypass procedure. Am J Roentgenol Radium Ther Nucl Med 119:484, 1973 2. Clark RE, Jacobson AC, Petty WE: Intrarenal mycotic (false) aneurysm secondary to staphylococcal septicemia. Radiology 115:421, 1975 3. Crosby IK, Killen DA, Shaikh AN, et al: Operative risk in coronary revascularization of patients with ventricular dysfunction. Am J Surg 128:746, 1974 4. Kahn PC: Iatrogenic diseasesof the arteries. Semin Roentgenol 5:284, 1970 5. Osler W: Gulstonian lectures on malignant endocarditis. Br Med J 1:467, 1885 6. Weintraub RA, Abrams HL: Mycotic aneurysms. Am J Roentgenol Radium Ther Nucl Med 102:354, 1968
