Culture of abdominal aortic aneurysm contents. An additional series

We evaluated the microbiologic nature of aneurysm contents. Aerobic and anaerobic cultures were taken from non-blood fluid, laminar thrombus, or ulcerated plaque within aortic aneurysms operated on during an eight-year period. Positive bacterial cultures were obtained from 22 (10.4%) of 211 aneurysms. Staphylococcus epidermidis was the most common organism recovered (12/22, 54%). Bacterial colonization of the arterial wall has a possible role in the pathophysiology of prosthetic graft sepsis. These data are valuable not only in choosing appropriate prophylactic antibiotics for aneurysm repair, but also in experimental efforts to develop an infection-resistant vascular graft by directing the antimicrobial characteristics of agents selected for binding to various prosthetic flow surfaces.     

Detection of C. pneumoniae by polymerase chain reaction-enzyme immunoassay in abdominal aortic aneurysm walls and its association with rupture.

OBJECTIVE: Serological studies have suggested that one of the risk factors for aneurysm development is C. pneumoniae infection. The purpose of this study was to evaluate whether there is an association between the presence of C. pneumoniae DNA in aneurysms and ruptured abdominal aortic aneurysms. METHODS: Aortic walls were collected consecutively from 30 patients with intact AAA, 16 patients with ruptured AAA and 19 healthy organ donors (control). Purified DNAs from all aortas were analyzed for the presence of C. pneumoniae DNA in parallel by polymerase chain reaction-enzyme immunoassay (PCR-EIA) and agarose gel electrophoresis. PCR-EIA has a high sensitivity in detecting low DNA copy number in clinical atherosclerotic samples. RESULTS: C. pneumoniae DNA was detected more frequently in patients with aneurysms, particular with ruptured aneurysms. The incidence of positive C. pneumoniae DNA was 73.3% in intact AAA and 10.5% in control aortas, with the highest frequency in ruptured AAA (100%) (p < 0.05). CONCLUSION: Giving the high specificity and sensitivity of PCR-EIA, these findings support the association of C. pneumoniae in the pathogenesis of aneurysm development, growth and rupture.     

Aneurysm contents as a source of graft infection.

During the past 5 1/2 years, cultures were taken from 68 to 151 surgically treated aortic aneurysms. These cultures were made from nonblood fluids, laminated clot, necrotic areas of the aneurysm wall, or ulcerated atheromatous plaques. Organisms were harvested from seven of the 68 cultures, including Staphylococcus, Escherichia coli, Pseudomonas, and hemolytic Streptococcus. Prophylactic antibiotics were used in all patients; however, the organisms cultured, excepting Streptococcus, were not sensitive to the chosen antibiotics. Three of the seven patients with a positive aneurysm culture died of causes unrelated to infection. Evidence of graft infection has not developed in four surviving patients with positive cultures. Knowledge of the presence of bacteria permitted massive antibiotic therapy based on organism sensitivity.     

Rupture of a smoldering mycotic aneurysm of the thoracic aorta into the lung.

A 65-year-old man was a diagnosed with meningitis and bacteremia, as Streptococcus pneumoniae was isolated from spinal fluid and blood cultures. After three weeks of antibiotic therapy, computed tomography revealed a ruptured aneurysm of the descending thoracic aorta. The aneurysm had appeared during the first episode of meningitis but had remained silent for two years. The patient underwent in situ Dacron graft replacement and his postoperative course was uneventful with no infectious complication.     

Infective endocarditis with cerebral mycotic aneurysm: treatment dilemma

Cerebral mycotic aneurysms are uncommon but severe complications of infective endocarditis. Management of these patients remains controversial. We present a case of a 23-year-old man who had infective endocarditis complicated by an intracranial mycotic aneurysm. Because antimicrobial therapy was not effective in reducing the size of the mycotic aneurysm, a decision was made to perform craniotomy before cardiac surgery. The patient underwent an open heart operation 20 days after aneurysm clipping. His postoperative course was uneventful, and the patient continues to be healthy without neurological complications.     

Multiple mycotic aneurysms due to Candida endocarditis.

Candida endocarditis is a serious condition which should be suspected in any patient with signs and symptoms compatible with bacterial endocarditis when cultures are negative. It should be managed by a medical-surgical approach which combines resection of all infected heart tissue and repair of any preexisting heart defects with appropriate antifungal therapy. Mycotic aneurysms should be treated by ligation of the vessel above and below the aneurysm, resection of the aneurysm, and implementation of appropriate antifungal or antibacterial therapy. Revascularization is not always necessary. When required, an extra-anatomic approach is preferable to placing a graft through the bed of the aneurysm.     

Arteritis due to Salmonella with aneurysm formation: two cases.

Although arterial infection due to Salmonella is rare, it remains one of the most common causes of primary mycotic aneurysms. The presentation is one of sepsis, cultures positive for Salmonella and rapid expansion or rupture of the aneurysm. The authors' experience at Victoria Hospital, London, Ont., includes two cases of aneurysms infected with Salmonella--one aneurysm of the aorta and the other of the common femoral artery. Both patients were treated by excision of the aneurysm, extra-anatomic reconstruction in an area remote from the infected field and long-term administration of appropriate antibiotics. One patient was alive and well 36 months after resection. The other died of multiple organ failure 10 days after resection. From a review of the English and French literature since 1948, 64 cases of abdominal aortic aneurysms infected with Salmonella were found; half of the patients survived the perioperative period. The diagnosis of mycotic aneurysm must be considered in any patient with an aneurysm and culture specimens positive for Salmonella. The authors favour wide débridement of the infected aneurysm with extra-anatomic reconstruction. This view is supported by a review of the literature. The appropriate antibiotic therapy is bactericidal rather than bacteriostatic.     

Femoral false aneurysms: a recommendation for the method of repair

False aneurysm formation is a major complication of vascular surgery. The most frequent site of anastomotic false aneurysm formation is the femoral artery. Between January 1974 and June 1986, 26 patients with 42 femoral false aneurysms were treated at the Princess Alexandra Hospital. Aneurysms developed following Dacron arterial grafting (29 aneurysms), saphenous vein grafting (10 aneurysms), umbilical vein grafting (one aneurysm) and femoral embolectomy (two aneurysms). Arterial wall failure (with intact suture and graft) was the most frequent operative finding. Ten recurrent aneurysms developed. There was a significantly greater number of recurrences when resuture or patch repair was employed than when an interposition graft was used as a repair. The development of a femoral anastomotic false aneurysm should be viewed as a total failure of that anastomosis and repair should be by replacement with an interposition graft rather than repair of the failed anastomosis by suture or patch.     

Deep leg vein reconstruction for an isolated mycotic common iliac artery aneurysm in an HIV-positive patient

Isolated mycotic common iliac artery aneurysms are rare, and as such, there is no consensus opinion on management. Traditional surgical options include resection with extra-anatomic bypass, placement of allograft or antibiotic treated synthetic graft, or autogenous vein reconstruction. We report the case of a 46-year-old, human immunodeficiency virus-positive male who presented with a recurrent pneumonia and new onset of right lower quadrant abdominal pain associated with right lower extremity swelling. computed tomographic scan revealed an isolated 9.5 cm right common iliac artery aneurysm with no evidence of rupture. Preoperative blood cultures grew out Streptococcus pneumoniae. Operative repair included aneurysm resection and reconstruction using an autogenous femoropopliteal vein interposition graft from the ipsilateral thigh. The patient had an uneventful recovery with resolution of his lower extremity swelling and a normal duplex exam at follow-up. Large mycotic common iliac artery aneurysms can be successfully treated with aneurysm resection and reconstruction using an autogenous femoropopliteal vein conduit. This technique obviates the need for extra-anatomic bypass or other forms of reconstruction using prosthetic material.     

Incidence and significance of intra-operative bacterial cultures during abdominal aortic aneurysmectomy.

Eighty patients undergoing abdominal aortic aneurysmectomy were studied to identify sources of potential graft sepsis. All but one patient received perioperative antibiotics. Samples obtained from aneurysm contents in 78 and bowel bag fluid in 45 were cultured for organisms. Twelve of 78 (15%) aneurysm cultures and five of 45 (11%) intestinal bag cultures yielded bacterial growth. Sixteen patients had positive cultures from either source and one from both, an overall incidence of 20%. Forty-four patients had asymptomatic aneurysms, 23 had symptomatic aneurysms, and 13 had ruptured aneurysms. A significantly greater frequency of bacterial growth occurred from ruptured than from non-ruptured aneurysms (p less than 0.05). Two patients (2.5%) developed graft sepsis. Comparing survivors followed a minimum of 6 months in the positive and negative culture groups, the late graft sepsis rate was 10% and 2% respectively. Two heretofore not widely recognized sources for late graft sepsis were identified: aneurysmal contents and intestinal bag fluid. Reasons for difference between potential graft sepsis incidence of 20% and actual incidence of 2.5% may include antibiotic therapy, host resistance, or other unidentified variables. Routine culture of aneurysm and intestinal bag contents is recommended. Upon identifying bacterial growth from such sources, organism-specific antibiotics are required.     

Consumption coagulopathy associated with aneurysms of the abdominal aorta and the bilateral femoral arteries. Report of a case

The authors report a case of a 70-year-old man, with repeating episodes of systemic subdermal hematoma due to consumption coagulopathy associated with abdominal aortic aneurysm and the bilateral femoral arterial aneurysms. Prior to the first operation for abdominal aortic repair, anticoagulation therapy was applied to treat thrombocytopenia and hypofibrinogenemia. Five years following the first surgery, the same treatment was required before resection of the femoral lesions. Consumption coagulopathy is seen in approximately 1-4% population of aortic aneurysms, however, repeated appearance of symptomatic coagulopathy is rarely reported. Anticoagulation therapy was effective to normalize the coagulation and fibrinolytic system and followed by uneventful surgical resection of the aneurysms.     

Endovascular treatment for a unusually large mycotic aneurysm manifesting as intracerebral hemorrhage - case report

A 62-year-old male presented with an unusually large mycotic aneurysm mimicking a saccular aneurysm manifesting as coma and hypotension. Computed tomography showed intracerebral and intraventricular hemorrhage. He was in septic shock due to acute infectious endocarditis. Cerebral angiography disclosed a large distal anterior cerebral artery aneurysm. The diagnosis was mycotic aneurysm based on the morphological features and associated endocarditis. The aneurysm and the parent artery were successfully occluded by endovascular embolization. High-dose antibiotic therapy in the following 6 weeks resulted in resolution of the infectious endocarditis. Early exclusion of ruptured mycotic aneurysm is mandatory because of the high risk of rerupture. Endovascular treatment is an effective alternative for mycotic aneurysms, especially if the patient's general condition is poor. Parent artery occlusion can be safely tolerated if the aneurysm is located distally.     

Significance of positive bacterial cultures from aortic aneurysm contents

Aneurysm contents were cultured in 275 patients out of a series of 546 cases undergoing infrarenal aortic aneurysm repair between 1961 and 1981. The incidence of positive cultures was 8 per cent. Cultures were more likely to be positive if taken from ruptured (16.7 per cent) and acute (9.1 per cent) aneurysms than from elective (4.2 per cent) cases (X2 = 6.69, P less than 0.01). Gram-positive organisms predominated with Micrococcus being the commonest isolate. Positive cultures were seen at an annual rate of 1-3 cases up to 1976 since which time all have been negative and we believe this may be due to prophylactic antibiotics being given preoperatively rather than postoperatively. The incidence of subsequent graft sepsis was greater in patients with positive aneurysm contents cultures (7 out of 22) than in those with negative cultures (6 out of 253) (X2 = 32.7, P less than 0.001). We recommend the routine culture of aneurysm contents to identify patients who are at high risk of developing graft sepsis and suggest that those cases with positive cultures receive prolonged organism-specific antibiotic therapy. In addition, there is evidence that pre-operative antibiotics may eliminate organisms from aneurysms, thus reducing the subsequent risk of graft sepsis.     

Listeria monocytogenes: a rare cause for an infected abdominal aortic aneurysm

Infected aneurysms associated with Listeria monocytogenes are rare. We describe a case of an infrarenal abdominal aortic aneurysm infected by Listeria monocytogenes. The aneurysm was diagnosed using a contrast-enhanced computed tomography (CT) scan and the infective organism identified within positive blood cultures. The patient underwent a successful urgent open aortic aneurysm repair and completed a 6-week course of antibiotics.     

Rupture of a Previously Thrombosed Thoracoabdominal Aneurysm

Spontaneous thrombosis of abdominal aortic aneurysms is rare. A patient with a 12-cm thoracoabdominal aneurysm developed sudden thrombosis of his aneurysm. He was treated with axillobifemoral bypass. He went on to rupture 7 months later. While spontaneous thromboses of abdominal aortic aneurysms have been previously reported, we did not find any reports of a thrombosed thoracoabdominal aneurysm or a subsequent rupture of this type of aneurysm. The literature on thrombosis of aneurysms is reviewed as well as proposed etiologies for thrombosis and subsequent rupture. We believe that resectional therapy may be warranted even in high-risk patients.     

Simultaneous mitral valve replacement and bypass grafting for mycotic aneurysm of the femoral artery during the active phase of infective endocarditis: a case report.

A 52-year-old woman with a 3-week history of fever and cough was diagnosed as having bacterial endocarditis with vegetation and severe mitral valve insufficiency by echocardiography. Blood culture revealed Streptococcus mitis. After antibiotic treatment for 3 weeks, the patient noticed swelling with pain in her left groin. Computed tomography revealed an occluded aneurysm in the left common femoral artery. Simultaneous surgical treatments of mitral valve replacement and bypass grafting using a saphenous vein following resection of the mycotic femoral arterial aneurysm were performed. Pathohistological examination of surgical specimens revealed acute inflammatory findings, but no microorganisms were found, probably because of the preoperative antibiotic therapy. Her postoperative course was uneventful, and there was no recurrence of mycotic aneurysms in a period of 10 months after the operation. Prompt recognition and urgent simultaneous surgical treatments for mycotic aneurysms complicated with infective endocarditis were effective.     

Enlargement of basilar artery aneurysms following balloon occlusion--"water-hammer effect". Report of two cases

Two patients with distal basilar aneurysms were treated with intra-aneurysmal balloon occlusion. After apparently successful therapy, follow-up angiograms demonstrated aneurysm enlargement with balloon migration distally in the sac. Geometric mismatch between the base of the balloons and the aneurysm neck together with transmitted pulsation through the 2-hydroxyl-ethylmethacrylate (HEMA)-filled balloon directly contributed to aneurysm enlargement. In this report, the authors discuss the problems of progressive aneurysm enlargement due to a "water-hammer effect" and the possibility of hemorrhage following subtotal occlusion.     

Thrombosis of difficult intracranial aneurysms by the endovascular placement of platinum-Dacron microcoils.

Patients with symptomatic aneurysms that are not excluded from the cerebral circulation have a poor prognosis. Standard treatment is surgical exploration with direct clipping of the aneurysm. Because of their large size or relationship to the base of the skull, some aneurysms may not be suitable for direct surgical clipping and may require alternative treatment modalities. A prospective clinical and radiological study of seven patients treated with the endovascular placement of platinum-Dacron microcoils to exclude the aneurysm from the cerebral circulation is reported. The seven patients ranged in age from 37 to 63 years; four were women. At completion of the endovascular procedure, total occlusion of the aneurysm with preservation of the parent artery had been achieved in four patients and 90% occlusion of the aneurysm in two. In the seventh patient, occlusion of the internal carotid artery resulted in the patient's death. At the 6-month follow-up review, both patients with an aneurysm less than 20 mm in size had persistent aneurysm thrombosis; however, the two patients with giant aneurysms had partial recanalization. Both required repeat thrombosis of their aneurysm with the placement of additional microcoils, one at 6 weeks and one at 6 months. These two patients have persistent aneurysm thrombosis at 12 months following their second procedure. The patient mortality rate for this study was 14%, while the procedure mortality/morbidity rate was 9%. It is concluded that thrombotic aneurysm therapy of difficult aneurysms is a safe procedure and will have a place in the treatment of selected aneurysms.     

Endovascular occlusion of wide-necked aneurysms with a new intracranial microstent (Neuroform) and detachable coils

OBJECTIVE: The long-term durability of the endovascular occlusion of cerebral aneurysms is one of the major factors limiting the more widespread use of this technique. Long-term occlusion of wide-necked aneurysms has improved with new assistive devices that seem to improve aneurysm occlusion while protecting the parent vessel. We report the use of a new intracranial stent--the Neuroform microstent--in the treatment of patients with wide-necked cerebral aneurysms. METHODS: Patients identified as harboring wide-necked intracranial aneurysms were evaluated for stent-assisted coiling. After appropriate anticoagulation was performed, depending on whether the aneurysm was ruptured or unruptured, the Neuroform stent was delivered across the neck of the aneurysm and deployed with a coil pusher. After stent placement, standard coil occlusion of the aneurysm was achieved in the majority of cases. RESULTS: Fifty-six patients were identified as having wide-necked intracranial aneurysms suitable for stent-assisted coiling. A total of 49 aneurysms in 48 patients were treated with this procedure. In eight cases, stent deployment failed. Forty-one of the aneurysms were initially stented, followed by coil placement. Six aneurysms were stented only, and one aneurysm was initially coiled, followed by stent placement. There were five deaths (8.9%), one of which occurred secondary to a stroke after the procedure (1.8%). Four patients (7%) experienced thromboembolic events, three of which were considered to have been secondary to the procedure (5.3%). In addition, there were two femoral pseudoaneurysms. The overall complication rate was 10.7%. Five patients were available for follow-up angiographic evaluation, and their cases are discussed. CONCLUSION: Intracranial stenting may overcome important technical limitations in current endovascular therapy by improving the occlusion of wide-necked aneurysms while protecting the parent vessel.     

Treatment of a celiac artery aneurysm with endovascular stent grafting--a case report

As a result of more sophisticated and more commonly performed investigative procedures, aneurysms of the visceral abdominal vasculature, including celiac artery aneurysms, are increasingly recognized. Traditional therapy for visceral artery aneurysms has been limited to open aneurysmectomy or aneurysmorrhaphy to prevent catastrophic aneurysmal rupture. However, these procedures are associated with significant postoperative morbidity and mortality despite technical successes. High complication rates are likely related to poor preoperative conditions among the patient population typically presenting with these visceral artery aneurysms. This report introduces an alternative therapy for visceral artery aneurysms and highlights the potential for catheter-based interventions. This case report depicts a 61-year-old morbidly obese woman diagnosed with a 10-centimeter celiac artery aneurysm during investigation of upper abdominal pain. Given the patient's poor medical condition, punctuated by hemodynamic instability, open operation was avoided, and percutaneous embolization was not feasible owing to a large aneurysm neck. Therefore, inflow to the celiac artery aneurysm was excluded by placing a modular stent graft component within the abdominal aorta at the celiac artery orifice. During the intervening 12 months since stent graft deployment, the aneurysm sac diameter has steadily decreased, as determined by serial computed tomography scans. This report underscores the potential for catheter-based techniques to offer new therapeutic options for patients with visceral artery aneurysms. Careful individualization is required given the highly variable size, location, and character of such lesions.