chronic inflammation and focal calcification. The postoperative course was benign, and the patient currently is

Transcription

1 Mycotic Aortic Aneurysm in Children Jacob Bergsland, M.D, Akira Kawaguchi, M.D., J. Michel Roland, M.D., Daniel R. Pieroni, M.D., and S. Subramanian, M.D. ABSTRACT Mycotic aneurysms of the aorta are uncommon in babies and children. Prior to the development of antibiotics, most mycotic aneurysms were seen secondary to bacterial endocarditis, but this is now uncommon. Instead, more cases have been reported as complications of umbilical artery catheters in newborns. We have seen five cases of mycotic aneurysms in children, two of them secondary to umbilical artery catheters. One patient had coarctation of the aorta, and the other patients had different sources of infection. Three patients were treated surgically by us with good results after antibiotic therapy. One patient died of sepsis before the aneurysm was diagnosed. The fifth patient was treated elsewhere and now has a recurrent aneurysm. We think a combination of aggressive medical and early surgical therapy may save a high percentage of these patients. Mycotic aortic aneurysm is an uncommon, frequently fatal condition occasionally seen in children. Within the last decade, several cases have been reported to occur after insertion of umbilical artery catheters. The clinical picture is usually dominated by sepsis, and many cases are still first diagnosed at postmortem examination. Angiography should be done early if this condition is suspected. Aggressive antibiotic therapy followed by early operative intervention may save many of the patients. Aneurysms detected later in the course should be operated on as soon as possible, since rupture of the aneurysm is unpredictable. Umbilical artery catheterization is a major risk factor, and strict technique is required when using these devices. The following case reports present our experience with 5 children with mycotic aortic aneurysm. Material and Methods Patient 1 A male infant was born at term after a normal pregnancy. Mild respiratory distress developed and was treated with constant positive airway pressure for three days. An umbilical artery catheter was used to monitor his condition. When the patient was 5 days old, Staphylococcus aureus septicemia developed. He was treated with antibiotics, and the umbilical artery catheter was removed. The patient responded well, but two weeks From the Departments of Cardiology and Cardiovascular Surgery, Chddren s Hospital, Buffalo, NY. Accepted for publication Aug 10, Address reprint requests to Dr. Subramanian, Division of Cardiovascular Surgery, 219 Bryant St, Buffalo, NY later a mediastinal mass was noted on chest roentgenogram. Angiography revealed multiple aortic aneurysms. A cardiovascular surgery consultant considered the aneurysms inoperable. At 6 months of age, the patient was doing well and was referred to the Children s Hospital of Buffalo. A repeat angiogram was made; the major findings are shown in Figures 1 and 2. At operation, the aneurysms were resected using one high thoracic and one thoracoabdominal incision. The aorta was cross-clamped intermittently, and the aneurysms resected one by one. Primary lateral closure was done without using graft material. Pathological examination of the aorta revealed chronic inflammation, and a culture grew enterococci. The postoperative course was benign. Currently the patient is doing well and has no signs of recurrence. Patient 2 A full-term male infant in a severely cyanotic condition was transferred to the Children s Hospital of Buffalo one day after birth. An umbilical artery catheter was inserted for monitoring. Heart catheterization showed transposition of the great arteries and patent ductus arteriosus. Balloon septostomy was performed, and the patient s condition improved markedly. The umbilical artery catheter was removed after two days, since the patient was doing well. Two days later, however, he became septic. Cultures of blood and umbilical secretions and from the tip of the catheter all grew S. aureus. In spite of appropriate antibiotic therapy, the patient continued to be febrile. A new upper mediastinal mass on the left side was now seen on the chest roentgenogram (Fig 3). The patient died after a continued downhill course. Postmortem examination revealed transposition of the great arteries, large septic thrombi in the right ventricle, septic emboli in the anterior descending coronary artery, and two large septic aneurysms at the level of the patent ductus arteriosus. This had also been the location of the tip of the umbilical artery catheter. Patient 3 A female infant was born at term and was well until she was 12 months old. At that time, a septic illness developed after a measles vaccination. The patient was treated with antibiotics. A large pericardial effusion was diagnosed, and a tap revealed straw-colored fluid. The results of culture were negative. She did well and was next seen eight years later for a cough. Calcifications in the ascending aorta were noted on routine chest roentgenograms. Cardiac catheterization and aortography showed a large aneurysm of the ascending aorta (Fig 4) but was otherwise normal. 314

2 315 Bergsland et al: Mycotic Aneurysms in Children Fig 1. (Patient 1. ) Thoracic aortogram showing a huge aneurysm of the descending aorta. Resection was done on cardiopulmonary bypass after dense adhesions of the pericardium were taken down. The golf ball-sized aneurysm was sitting 1cm above the aortic ring and ended just before the innominate artery. The defect was repaired with a Dacron patch. Pathological examination revealed an aortic aneurysm with chronic inflammation and focal calcification. The postoperative course was benign, and the patient currently is doing well. COMMENT. In spite of the negative results of cultures during the patient s febrile illness, we consider the clinical course and pathological findings typical for a mycotic aneurysm. Patient 4 A female infant was born at term after an uncomplicated pregnancy. She was well until the age of 4 years at which time S. aureus septicemia developed. The source of the sepsis was unknown. The patient had a heart murmur, and it was thought she might have had bacterial endocarditis. She was treated successfully with antibiotics. When the patient was 7 years old, a routine examination revealed a large, pulsatile mass in the abdomen. An angiogram showed an abdominal aortic aneurysm (Fig 5). The results of cardiac catheterization were normal. At operation, the aneurysm was found below the inferior mesenteric artery. Aneurysmectomy was done and a 13 mm bifurcation Dacron graft used for replacement. Pathological examination showed intimal thickening and inflammatory changes. Fig 2. (Patient 1. ) Abdominal aortogram showing two abdominal aortic arrows) and two left iliac aneurysms (white arrows). The patient is asymptomatic 12 years after operation. A repeat angiogram showed mild stenosis of the distal anastomosis. Patient 5 A 3x-year-old boy who was a Jehovah s Witness was admitted to another hospital with bacterial endocarditis caused by S. aureus. He was known to have coarctation of the aorta. He was treated with appropriate antibiotics, but peripheral emboli and continued sepsis worsened his condition. An enlarging mass was seen in the upper mediastinum on chest roentgenograms. Emergency right heart catheterization and angiography were done and revealed a large, leaking aneurysm of the descending aorta just distal to a juxtaductal coarctation. The aortic valve could not be seen well, but a two-dimensional echocardiogram showed a bicuspid aortic valve with vegetations. The patient underwent a left thoracotomy. The aneurysm was 7 cm in diameter and grossly infected. The aorta was clamped and opened opposite to the perfora-

3 316 The Annals of Thoracic Surgery Vol 37 No 4 April 1984 Fig 3. (Patient 2.) Chest roentgenogram made one week after removal of umbilical artery catheter. The large mass (arrows) in the superior mediustinum corresponded to the location of the tip of the umbilical artery catheter that M S removed. Fig 5. (Patient 4. ) Abdominal aortogram showing large abdominal aortic aneurysm (arrows). tion. The necrotic part of the aortic wall was excised, and primary closure was done from the inside of the aorta. Then a subclavian angioplasty was performed to enlarge the lumen. The patient recovered. Four years later, the patient was seen in our hospital for evaluation. A two-dimensional echocardiogram showed a bicuspid, thickened aortic valve. Cardiac catheterization revealed an aortic valve gradient of 100 mm Hg. A recurrent aneurysm in the area of the previous coarctation was seen on angiography (Fig 6). A computed tomographic scan of the chest showed the size of the aneurysm to be 20 mm. With the patient on cardiopulmonary bypass, aortic valvotomy was performed. He did well postoperatively. Blood pressure was controlled to avoid rupture of the aneurysm. Because of the family's refusal to accept blood transfusion, the child was discharged on a regimen of iron medication. At that time, resection of the aortic aneurysm was planned for one to two months later. Comment Fig 4. (Patient 3. ) Lateral aortogram showing posterior location of large ascending aortic aneurysm (arrows). Mycotic aneurysms of the aorta are uncommon, especially in children with an undiseased aorta. In 1923, a survey by Stengel and Woelferth [l]found 217 patients with mycotic aneurysms, sixty-six of which were located in the aorta. Only 14 of the 217 patients were children. Of the patients, 187 had evidence of endocarditis; other types of bacterial infections were present in 30.With the

4 317 Bergsland et al: Mycotic Aneurysms in Children Fig 6. (Patient 5.) Anterior aortogram showing large aneuysm at site of previous coarctation. The right subclavian artery takes off aberrantly from the aneu y sm (arrow). development of effective antibiotics, these causes of mycotic aneurysm may be seen less frequently. However, they still occur, as in our Patients 3 and 4 and as reported by several authors [2-71. Coarctation of the aorta is known to predispose to bacterial endocarditis [S] and development of mycotic aneurysm [2], especially if there is a coexistent bicuspid aortic valve. The use of umbilical artery catheters in newborns has created a new group at risk for development of mycotic aortic aneurysms or pseudoaneurysms ( The diagnosis of mycotic aneurysm of the aorta is often difficult. In the acute stage, sepsis usually dominates the clinical picture. A chest roentgenogram and a good clinical examination of the abdomen are important. A computed tomographic scan and ultrasonogram are helpful [5], but aortography will be required in most instances for accurate anatomical delineation. Many cases of mycotic aneurysm are still not diagnosed before postmortem examination (9, 111, as in our Patient 2. Other patients have been explored for mediastinal masses thought to be tumors [14], sometimes with catastrophic results [6, 71. The clinical course is unpredictable. The patient may die early of uncontrolled sepsis [9, 10, 131. If he or she survives the septic stage, rupture is a danger that is always present. Parkhurst and Decker [15] found a 50% incidence of rupture in their 12 patients. Rupture may occur rapidly in spite of appropriate antibiotic therapy [13]. Other aneurysms may not rupture for years, as in 2 of our patients. Spontaneous cure by thrombosis has been reported in a patient with a thoracic aortic aneurysm without any treatment [16]. Previously, treatment was limited to ligation and excision of mycotic aneurysms of the peripheral arteries [l]. The optimal treatment today is antibiotic therapy followed by early operative intervention [13]. If operation is done too early, bacteria may still be present and the insertion of prosthetic graft material could cause postoperative reinfection [17]. Our first patient was operated on six months after the initial sepsis, but the results of culture of the aneurysm tissues were positive even though there was no gross infection. Graft material was not required, and this may have prevented reinfection. Operation without use of graft material has been done successfully as early as four days after initiation of antibiotic therapy, and the result was good [MI. In patients requiring very early operation at a stage at which active infection is uncontrolled, the situation is more difficult. A foreign body should not be utilized in the area of infection, and it may be necessary to ligate the proximal and distal aorta and perform an extraanatomical bypass. In Patient 5 who was operated on elsewhere, operation could not be delayed since the aneurysm was leaking. The aneurysm was grossly infected. It was excised and the coarctation repaired by a subclavian angioplasty. This method has been used with apparent success in a patient with an infected Dacron patch after coarctation repair [19], but in our patient, the aneurysm recurred and reoperation has become necessary. References 1. Stengel A, Woelferth CC: Mycotic (bacterial) aneurysms of intravascular origin. Arch Intern Med 31:527, Fricker FI, Park SC, Neches WH, et al: Aneurysm of the aorta in children. Chest 76:305, Javett SN, Kahn E: Rupture of a mycotic aneurysm of the thoracic aorta. Arch Dis Child 27:294, Mitchell RG, Claireaux AE: Mycotic aneurysm of the abdominal aorta. Arch Dis Child 27147, Rose JS, Hotson WC, Levin DC: Abdominal aortic aneurysm in childhood. Am J Roentgenol Radium Ther Nucl Med 123:708, Siege1 MJ, McAlister WH: Aortic aneurysms in children. Radiology 132:615, Wood BP, Young LW, Elbadawi NA: Primary mycotic aneurysm in infancy and childhood. Am J Roentgenol Radium Ther Nucl Med 118:109, Campbell M: Natural history of coarctation of the aorta. Br Heart J 32:633, Colclough AB, Barson A]: Infantile aortic aneurysm complicating umbilical arterial catheterization. Arch Dis Child 56795, Faer MJ, Taybi H: Mycotic aortic aneurysm in premature infants. Radiology 125:177, Rais J, Finnstroem 0, Wesstroem G: Aortic aneurysm developing after umbilical artery catheterization. Acta Paediatr Scand 65:495, Spangler JG, Kleinberg F, Fulton RE, et al: False aneurysm of the descending aorta. Am J Dis Child 131:1258, 1977

5 318 The Annals of Thoracic Surgery Vol 37 No 4 April Thompson TR, Tilleli J, Johnson DE, et al: Umbilical artery catheterization complicated by mycotic aortic aneurysm in neonates. Adv Pediatr 27275, Cliff MM, Soulen RL, Finestone AJ: Mycotic aneurysm: a challenge and a clue. Arch Intern Med , Parkhurst GF, Decker JP Bacterial aortitis and mycotic aneurysm of the aorta. Am J Pathol31:821, Barker WF: Mycotic aneurysm. Ann Surg 139:84, Bennett DE: Primary mycotic aneurysms of the aorta. Arch Surg 94:758, Malloy MH, Nichols MM: False abdominal aortic aneurysm: an unusual complication of umbilical arterial catheterization for exchange transfusion. J Pediatr 90:285, Kirsh MM, Percy 8, Spooner E: Management of pseudoaneurysm following patch grafting for coarctation of the aorta. J Thorac Cardiovasc Surg 74536, 1977 Notice from the American Board of Thoracic Surgery The American Board of Thoracic Surgery will begin its recertification process in Diplomates interested in participating in this examination should maintain a documented list of the cardiothoracic operations they performed during the year prior to application for recertification. They should also keep a record of their attendance at thoracic surgical meetings and other continuing medical education activities for the two years prior to application for recertification. In place of a cognitive examination, candidates for recertification will be required to complete both the general thoracic and cardiac portions of the SESATS (Self-Educationklf-Assessment in Thoracic Surgery) I1 Syllabus. Diplomates whose 10-year certificates will expire in 1986 may begin the recertification process in Their new certificate will be dated 10 years from the time of expiration of the original certificate. Pecertification is also open to any Diplomate with an unlimited certificate. The deadline for submission of applications is July 1, A recertification brochure outlining the rules and requirements for recertification in thoracic surgery is available on request from the American Board of Thoracic Surgery, E Seven Mile Rd, Detroit, MI