CASE REPORTS. Surgical Treatment of Mycotic Aneurysm Associated with Coarctation of the Aorta. H. Newland Oldham, Jr., M.D., Joseph F. Phillips, M.D.

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1 CASE REPORTS Surgical Treatment of Mycotic Aneurysm Associated with Coarctation of the Aorta H. Newland Oldham, Jr., M.D., Joseph F. Phillips, M.D., Paul H. Jewett, M.D., and James T. Chen, M.D. ABSTRACT Mycotic aneurysm is a rare complication associated with coarctation of the aorta. A review of 13 patients treated surgically for this combination of lesions illustrates the typical pathological characteristics, the importance of proper timing of surgical intervention, and the significant improvement in survival following excision of the aneurysm and coarctation after a course of appropriate antibiotic therapy. D evelopment of an aneurysm in the thoracic aorta, the intercostal arteries, or the cerebral vessels is not an uncommon occurrence in patients with coarctation of the aorta. These aneurysms are related to sustained hypertension and structural alterations in the vessel walls and are found with increasing frequency in older patients. Abbott [l] examined 200 postmortem specimens from patients with coarctation and found 39 aneurysms. In a more recent clinical series, Schuster and Gross [14] reported that 9% of 505 patients undergoing operation for coarctation had aneurysms but only 2y0 of these aneurysms involved the aorta. Mycotic aneurysm associated with coarctation of the aorta is a distinctly less common complication that occurs more frequently in younger patients, often develops rapidly, and usually ruptures if left untreated. The role of surgical excision in the management of patients with mycotic aneurysm and coarctation of the aorta is illustrated by the course of a child undergoing successful operative treatment and a review of 12 previously reported patients. From the Departments of Surgery, Radiology, and Pediatrics, Duke University Medical Center, Durham, N.C. Accepted for publication Sept. 19, Address reprint requests to Dr. Oldham, Department of Surgery, Duke University Medical Center, Durham, N.C VOL. 15, NO. 4, APRIL,

2 OLDHAM ET AL. A 5-year-old boy was referred to Duke University Medical Center on November 18, 1970, for evaluation of coarctation of the aorta. He was first noted to have a heart murmur at 1 month of age, but he had remained asymptomatic until July, 1970, when he was hospitalized for evaluation of fever, chills, and malaise. Physical examination at that time demonstrated a harsh systolic murmur best heard over the second left intercostal space and radiating to the back. Blood pressures of 180/ 110 mm. Hg were recorded in the arms and 70 mm. Hg systolic in the legs, and both femoral pulses were reduced in amplitude. The chest roentgenogram demonstrated mild cardiomegaly and an indentation of the descending thoracic aorta. No rib notching was present, and there was no evidence of an aortic aneurysm. After multiple blood cultures produced coagulase-positive Staphylococcus, the patient was treated for six weeks with intravenously administered antibiotics. When first seen at Duke University Medical Center, the patient was asymptomatic and had no physical or laboratory evidence of persistent infection. Blood cultures at this time were sterile. A repeat chest film on November 21, 1970, demonstrated a large posterior mediastinal mass that compressed the left main-stem bronchus and displaced the esophagus (Fig. 1). The mass did not pulsate during fluoroscopic examination. Cardiac catheterization and cineangiography documented coarctation of the descending aorta and a saccular aneurysm originating just beyond the site of coarctation (Fig. 2). No abnormality of the aortic valve was detected. At operation the saccular aneurysm was found to measure 7 cm. in diameter and to communicate with the lateral aspect of the descending aorta just distal to the coarctation. A 3 cm. section of aorta containing the coarctation and the origin of the aneurysm was resected, and a primary FZG. 1. Chest films obtained three months after antibiotic treatment, demonstrating a large posterior mediastinal mass. 412 THE ANNALS OF THORACIC SURGERY

3 CASE REPORT: Mycotic Aneurysm in Coarctation FIG. 2. Cineangiogram demonstrating coarctation of the aorta and opacificution of a saccular aneurysm originating just distal to the coarctation. anastomosis of the aorta was performed using interrupted Tevdek sutures. Microscopical examination of the specimen demonstrated a thin, fibrous tissue wall without any definite aortic tissue. The pathological diagnosis was that of a false aneurysm. No bacteria or vegetations were present, and no organisms were recovered from culture of the specimen. The patient s postoperative course was uncomplicated, and he was discharged on the fifteenth day after the operation. Six months later the patient remained asymptomatic and was admitted for repeat cardiac catheterization. The aortic anastomosis was patent, and there was no difference in pressure measured above and below the site of resection. A small ventricular septa1 defect was demonstrated. The aortic valve again appeared normal. The patient has remained well eighteen months following his operation. Comment The natural history of coarctation of the aorta was clearly established by Abbott s [l] series of 200 patients dying with coarctation of the aorta, followed by a later review of 104 patients by Reifenstein and associates [13]. Endocarditis or aortitis accounted for 16 and 22y0, respectively, of the deaths in these reports. In 1960 Skandalakis and his co-workers [17] analyzed the course of 106 patients with coarctation of the aorta and an associated aneurysm reported after Abbott s review in Thirty-two, or 26y0, of these patients were diagnosed as having a mycotic aneurysm, although documentation was not always complete. Following the introduction of elective surgical resection for coarctation of the aorta, the reported incidence of mycotic aneurysms has decreased

4 OLDHAM ET AL. considerably. Kieffer and his colleagues [9] in 1961 reported 19 patients with a mycotic aneurysm arising distal to a coarctation. Only 2 of these patients were treated surgically. Because of the rapid and almost uniformly fatal course of this condition, surgical therapy has become the treatment of choice since the first successful resection of a mycotic aneurysm associated with coarctation was reported by Shumacker [16] in The results of operative treatment of 12 previously reported patients and our patient, the thirteenth, are presented in the Table. Two previously reported patients who were found to have aneurysms 11 and 13 years following a septic illness are excluded from this discussion because of lack of documentation of the relationship between their infection and the subsequent late demonstration of an aneurysm [8, lo]. Eleven of the 13 patients were males ranging in age from 8 months to 20 years, with an average age of 8 years. This contrasts with the average age in the third decade reported by Skandalakis and co-workers [17] for patients with all types of aneurysm found with coarctation. The diagnosis in these 13 patients was established by the triad of a febrile illness, positive blood cultures, and the development of a mediastinal mass in a patient with the clinical findings of coarctation of the aorta. The clinical course in all 13 patients was typical of septicemia, and 9 of the 13 had bacteria demonstrated by blood culture or by culture of the resected tissue. The organism most commonly identified was Staphylococcus. None of the patients developed evidence of aortic insufficiency either before or after operation. Organisms were identified in both the aneurysm wall and in the aortic valve of 1 patient who died during operation. Because of the high incidence of deformed aortic valves in patients with coarctation, the most common site of endocarditis in a patient with coarctation is the aortic valve. The development of a mycotic aneurysm without clinical evidence of aortic valve involvement in 12 of these 13 patients, however, clearly indicates that the area adjacent to the coarctation may be susceptible to bacterial invasion. The rapid development of a mycotic aneurysm was documented in these patients by serial changes in the chest roentgenograms. Eleven patients had chest films obtained prior to their clinical illness which showed no evidence of an aneurysm. All 13 patients had mediastinal enlargement demonstrated by a film obtained during or immediately following the episode of septicemia. The average time interval between a normal chest film and one demonstrating the aneurysm was seven weeks and ranged from six days to four months. In most instances the mass was located in the left posterior mediastinum adjacent to the left main-stem bronchus or esophagus. Fluoroscopic pulsation, which was not seen in our patient, has not been a reliable method of distinguishing vascular and nonvascular mediastinal lesions [12]. The average duration from the onset of clinical infection to surgical treatment was three months and ranged from three weeks to seven 414 THE ANNALS OF THORACIC SURGERY

5 RESULTS OF SURGICAL TREATMENT FOR MYCOTIC ANEURYSM WITH COARCTATION OF THE AORTA to Operation from Infection Interval Pt. No., Author, Year Age & Sex Organism Pathology Operation Results 1. Shumacker, 1948 [16] 2. Sellors, 1956 [15] 3. Cleland et al., 1956 [3] 4. Kieffer et al., 1961 [9] 8, M 9, M 20, M 15, M Pneumococcus Staphylococcus Streptococcus... 2 mo. 7 mo.... 1y2 mo. Small distal saccular false Primary aneurysm anastomosis 6 cm. distal saccular Homograft aneurysm 4.5 cm. distal saccular Homograf t false aneurysm Distal false aneurysm Thoraco tomy ruptured into pleural space 5. Dotter et al., 1961 [5] 6, M Homograft Distal false aneurysm ruptured into mediastinum Distal false aneurysm 6. Edwards et al., 1962 [6] 5, M Staphylococcus 3 wk. Subclavian- d r 7. Steinberg & Hagstrom, L cn 2: 0 le 1964 [18] 8. Wood, 1965 [19] 9. Wood, 1965 [19] 10. Khazei & Cowley, 1967 [8] 11. Matthews et al., 1967 [ll] 12. Cossette et al., 1969 [4] 13. Oldham et al. [present report] 8 mo., F 5, F 16, M 7, M 8, M 3, M 5, M Streptococcus & staphylococcus... 4 mo. 2 mo. 3 cm. proximal fusiform true aneurysm Distal fusiform true aneurysm 5 cm. distal saccular false aneurysm ruptured into pleural space to-aor t a anastomosis Died during operation Died after 4 mo. with aortic infection Staphylococcus 1 mo. Thor aco tomy Died during operation Staphylococcus... Moraxella Staphylococcus 6 mo. 2 mo. 1 mo. 10 cm. distal saccular false aneurysm 6 cm. distal saccular aneurysm ruptured into esophagus 7 cm. distal saccular false aneurysm 7 cm. distal saccular false aneurysm Primary anastomosis Teflon graft Teflon graft Dacron graft Teflon graft Primary anastomosis 5 mo.

6 OLDHAM ET AL. months. All patients received antibiotic treatment for intervals of one week to four months. The aneurysm originated just distal to the coarctation in 12 of the 13 patients and was saccular in 11 of the 12 adequately described. Only 1 patient had a fusiform aneurysm located proximal to the coarctation. The pathological description in 9 instances was sufficient to determine that 7 specimens were composed of fibrous tissue, adjacent mediastinal pleura, and adherent lung, findings that are consistent with the histological diagnosis of a false aneurysm. The typical finding was, therefore, that of a saccular false aneurysm originating distal to the coarctation. In 5 patients the aneurysm had ruptured and was partially contained by surrounding tissues. Two ruptured into the free pleura, 2 into the mediastinum, and 1 into the esophagus; the last was accompanied by massive hematemesis. There have been several theoretical proposals for the typical location of this infective process causing destruction of the aortic wall and either acute rupture or false aneurysm formation. Clagett, Kirklin, and Edwards [2] have emphasized the importance of the thickened area of intima characteristically located just beyond the coarctation. This intimal irregularity is thought to be susceptible to direct bacterial invasion. Abbott [ 11 described the kinking of the aorta in this location as a locus minoris resistentiae for formation of aneurysms. It has also been postulated that the aortitis may originate from septic emboli from the aortic valve by way of either the aortic lumen or the vasa vasorum. The low incidence of aortic valve involvement by endocarditis in this series supports the thesis that the deformed aorta just beyond the coarctation can be the site of primary bacterial aortitis with subsequent aneurysm formation. All 13 patients reviewed were treated surgically following varying periods of antibiotic administration. Five patients had operation on an emergency basis because of rupture of the aneurysm during the first to fifth week of antibiotic therapy. Four of these 5 had clinical evidence of persistent infection at the time of operation. Two of these patients died from hemorrhage prior to completion of the surgical procedure. One patient surviving operation died four months later with mediastinal infection and disruption of the aortic anastomosis. Remarkably, 2 patients operated on for rupture during the acute infected stage were long-term survivors, both with grafts inserted in the aorta. The remaining 8 patients underwent elective operation after an average of seven weeks of antibiotic treatment. No clinical evidence of infection was present at the time of operation, and all these patients survived operation. In the 11 patients with completed operations, several methods were used to reconstruct the area of the resected coarctation and aneurysm. Grafts of various types were inserted in 7 patients: three aortic homografts, three Teflon grafts, and three Dacron grafts. One patient had anastomosis of the 416 THE ANNALS OF THORACIC SURGERY

7 CASE REPORT: Mycotic Aneurysm in Coarctation subclavian artery to the aorta, and 3 patients had a primary end-to-end aortic anastomosis performed. Most aneurysms in this series arose from the first several centimeters of aorta distal to the coarctation. Knowledge of this fact should make it possible to perform a primary anastomosis in most situations if care is taken to preserve the remaining wall of the aorta after removing the saccular aneurysm. In spite of the low incidence of recurrent infection in these patients, it is advisable to avoid inserting a graft, if possible, in the setting of aortic wall infection. Cardiopulmonary bypass was not utilized in any patient in this series, although Cossette and associates [4] successfully inserted a temporary graft between the ascending and descending aorta before dissecting the mediastinal hematoma in a patient with a ruptured aneurysm. Either of these adjuncts may be helpful in an emergency situation in view of the 40oj, operative mortality from hemorrhage in those patients with a ruptured aneurysm. The proper timing of surgical intervention remains a difficult clinical decision. Ideally, the patient should be treated for six weeks with antibiotics and be free of all evidence of infection at the time of operation. When this is possible, surgical treatment has been uniformly successful. This ideal must be weighed against the average interval from infection to rupture of three months in those patients undergoing operation and the finding of rupture in 5 patients in this series during the first five weeks of antibiotic treatment. During the period of antibiotic administration, all patients should be closely observed for evidence of rapid enlargement of the aneurysm, diffuse mediastinal enlargement, or development of pleural effusion, hemoptysis, or hematemesis. When faced with any of these findings of impending or actual rupture of the aneurysm, emergency operation becomes mandatory. References 1. Abbott, M. E. Coarctation of the aorta of the adult type. Am. Heart J. 3:574, Clagett, 0. T., Kirklin, J. W., and Edwards, J. E. Anatomic variations and pathologic changes in coarctation of the aorta. Surg. Gynecol. Obstet. 98: 103, Cleland, W. P., Counihan, T. B., Goodwin, J. F., and Steiner, R. E. Coarctation of the aorta. Br. Med. J. 2:379, Cossette, R., Davignon, A., and Stanley, P. Ruptured aortic aneurysm in a 3I/-year-old child with coarctation of the aorta. Can. Med. Assoc. J. 100:257, Dotter, C. T., Niles, N. R., and Steinberg, I. Impending aortic rupture. N. Engl. J. Med. 265:214, Edwards, B. F., Gray, S. W., Hopkins, W. A., Davis, B. M., and Skandalakis, J. E. Coarctation of the aorta complicated by the formation of an aneurysm. Surgery 52:444, France, N. E., Levin, B., and McNicholl, B. Coarctation of the aorta (adult type) with rupture distal to the coarctation. Arch. Dis. Child. 25:175, Khazei, A. H., and Cowley, R A. Mycotic aneurysm associated with coarctation of the aorta. Am. Surg. 33:325, 1967.

8 OLDHAM ET AL. 9. Kieffer, S. A., Linde, L. M., Kegel, S. M., and Latta, H. J. Mycotic aneurysm distal to coarctation of the aorta. J. Thorac. Cardiovasc. Surg. 42:507, Lawrence, G. A. Mycotic aneurysm associated with coarctation of the aorta. Lancet 2: 1066, Matthews, G. B., Buzzi, A., Armesto, J. C., and Gueblon, M. Surgical correction of aneurysm of descending aorta associated with coarctation and patent ductus arteriosus. Vasc. Surg. 1: 152, Oldham, H. N., Jr., and Sabiston, D. C., Jr. Primary tumors and cysts of the mediastinum: Lesions presenting as cardiovascular abnormalities. Arch. Surg. 96:71, Reifenstein, G. H., Levine, S. A., and Gross, R. E. Review of 104 autopsied cases of coarctation of adult type, two years of age or older. Am. Heart J. 33: 146, Schuster, S. R., and Gross, R. E. Surgery for coarctation of the aorta. J. Thorac. Cardiovasc. Surg. 43:54, Sellors, T. H. Coarctation of the aorta associated with aneurysm. Br. J. Surg. 43:365, Shumacker, H. B. Coarctation and aneurysm of the aorta: Report of a case treated by excision and end-to-end suture of aorta. Ann. Surg. 127:655, Skandalakis, J. E., Edwards, B. F., Gray, S. W., and Davis, B. M. Coarctation of the aorta with aneurysm. Surg. Gynecol. Obstet. 111:307, Steinberg, I., and Hagstrom, J. W. C. Prestenotic mycotic aneurysm complicating coarctation of the aorta. Radiology 82:626, Wood, T. J. Coarctation of the aorta associated with mycotic aneurysm. Med. J. Aust. 2:452, THE ANNALS OF THORACIC SURGERY