Stent-Graft Treatment of Infected Aortic and Arterial Aneurysms

PURPOSE

To evaluate the feasibility and effectiveness of endovascular stent-graft repair of infected aortic and arterial aneurysms.

METHODS

Eight patients (5 men; mean age 56.6 years, range 30-85) with infected saccular aneurysms in the brachiocephalic artery (n=1), proximal descending thoracic aorta (n=1), infrarenal abdominal aorta (n=3), common iliac artery (n=1), and common femoral artery (n=2) were treated with stent-graft placement and intravenous antibiotic treatment for at least 6 weeks followed by case-specific administration of oral suppressive antibiotics. All patients were considered to be in the high-surgical-risk group.

RESULTS

Exclusion of the infected aneurysm was successful in all patients. However, 2 patients died within 30 days of uncontrolled sepsis, and 1 patient died at 6 months after rupture of a persistently infected aneurysm (37% mortality rate). Over a follow-up that ranged to 8 years, the 5 survivors showed complete resolution of the infected aneurysms; no stent-graft infection was observed during follow-up.

CONCLUSION

The acceptable technical and clinical success of endovascular aneurysm repair makes this a promising treatment for infected aortic and arterial aneurysms. However, it is crucial that the infection is treated adequately prior to stent-graft placement.

Staged endovascular treatment for complicated type B aortic dissection

BACKGROUND

A 40-year-old man presented with acute chest and back pain, hypertension and anuria. Two years previously he had been diagnosed with acute uncomplicated type B aortic dissection. Following conservative management, with aggressive antihypertensive therapy and analgesia, he was monitored with 6-monthly surveillance CT scans. These demonstrated a complicated type B dissection with renal and iliac malperfusion.

INVESTIGATIONS

Multislice CT, transthoracic and transesophageal echocardiography, digital subtraction aortography.

DIAGNOSIS

Acute-on-chronic type B aortic dissection, complicated by aneurysmal dilatation of the thoracic aorta and visceral malperfusion.

MANAGEMENT

Antihypertensive therapy; staged thoracoabdominal and branch vessel endoluminal repair (STABLE procedure), with stabilization of the dissection and rescue of renal function; CT imaging surveillance to monitor for any further complications.

[Aortic involvement in patients with temporal arteritis and polymyalgia rheumatica]

In 4 patients with temporal arteritis or polymyalgia rheumatica, women aged 60, 57, 83 and 73 years respectively, signs of aortic involvement were established. The first patient presented with signs of systemic inflammation without signs of temporal arteritis or aortitis. In the second, an acute symptomatic thoracoabdominal aneurysm developed. In the third, temporal arteritis was associated with chronic progressive dilatation ofthe thoracic aorta. The fourth developed signs of intermittent claudication of the extremities. The clinical manifestations in all patients were attributed to chronic inflammation of the aorta caused by giant cell arteritis. Aortic giant cell arteritis frequently accompanies temporal arteritis, but is rarely diagnosed. Up to 75% of patients with temporal arteritis may have some degree of aortic involvement. Thoracic aneurysms, complicated by rupture or dissection, are the most serious complications. Aortic disease associated with signs of systemic inflammation should trigger the suspicion of giant cell arteritis. Corticosteroids are the most important part of treatment. Three patients recovered following treatment; the first two received an endoprosthesis; in the woman aged 83 years, this was not technically possible; she died after 1.5 years.

Mycotic Aneurysm of the Descending Thoracic Aorta in a 2-kg Neonate

Umbilical artery catheterization is often performed in critically ill neonates. Infection and thromboembolic events are relatively frequent complications, but aneurysm formation is rare. We describe the case of a premature baby who developed a rapidly expanding aneurysm of the descending thoracic aorta, secondary to a highly placed infected umbilical catheter. The rapid progression under medical therapy prompted us to replace the thoracic aorta with an 8-mm polytetrafluoroethylene graft, using extracorporeal circulation and core cooling. The baby had an excellent recovery and was discharged home after a prolonged antibiotic course. He is being followed with repeated imaging studies for a small abdominal aneurysm. We describe a novel approach to this rare and complicated problem and provide a review of the literature on the subject.

The inadvertent administration of anticoagulants to ED patients ultimately diagnosed with thoracic aortic dissection

OBJECTIVES

Aortic dissection (AD) may present similarly to acute coronary syndrome or pulmonary embolus; however, anticoagulation may be detrimental to patients with AD.

METHODS

Clinical data were abstracted from medical records of emergency department (ED) patients with nontraumatic AD. Patients administered with anticoagulants were compared with non-anticoagulated patients with regard to presenting symptoms, chest radiograph and electrocardiogram (ECG) findings, and outcome.

RESULTS

A total of 44 ED patients with nontraumatic AD was identified over a 4-year period; anticoagulants were administered to 9 (21%). Anticoagulated patients had a higher incidence of chest pain without back pain (78% vs 23%; P = .002) and ST elevations or depressions on ECG (89% vs 6%; P < .001) and were less likely to have a widened mediastinum on chest radiograph (0% vs 67%; P < .001). Two ED anticoagulated patients died, one required a second surgery for bleeding complications, and another suffered a stroke after reversal of anticoagulation.

CONCLUSIONS

There is a clinically significant incidence of anticoagulation administration to ED patients ultimately diagnosed with AD, especially in the presence of ambiguous ECG and radiographic findings.

INvestigation of STEnt grafts in patients with type B Aortic Dissection: design of the INSTEAD trial--a prospective, multicenter, European randomized trial

PURPOSE

This study describes the design of an ongoing randomized trial initiated to compare the 2-year outcome of uncomplicated type B aortic dissection when treated by endovascular implantation of a Medtronic Talent stent graft adjunctive to best medical treatment versus best medical treatment alone.

METHODS

Patients older than 18 years with type B aortic dissection as diagnosed by computed tomography or magnetic resonance angiography are randomized to either a thoracic aortic endoprosthesis and antihypertensive treatment, called "stent grafting," or a tailored antihypertensive treatment, called "medical treatment." Only patients in a clinically stable condition and without spontaneous thrombosis of the false lumen after 14 days of the index dissection are considered eligible for study inclusion.

RESULTS

Primary outcome measure is all-cause mortality. Secondary outcome variables include conversion to stent and/or surgery, induced thrombosis of the false lumen, cardiovascular morbidity, aortic expansion (>5 mm/y of maximum diameter including true and false lumina), quality of life, and length of intensive care unit and hospital stay. The study design calls for 136 patients to be randomized and monitored for 24 months.

CONCLUSIONS

The INSTEAD trial is the first randomized trial investigating the role of endoluminal treatment of uncomplicated type B aortic dissection. By the end of December 2004, 125 patients were randomized, accounting for 92% of the target. Final results of the INSTEAD trial should be available in 2006.

Could medical intervention work for aortic aneurysms?

BACKGROUND

Aortic aneurysms represent a serious and common condition. Current therapies are based on mechanical treatment. With increased knowledge of the biochemical mechanisms responsible for aneurysm expansion, it may be possible to prevent the growth of small aneurysms.

METHODS

A series of experiments performed in the investigator's laboratory during the past decade is outlined to show the evolution of our concepts of the processes underlying aneurysm formation and progression.

RESULTS

Our understanding of aortic aneurysms has changed dramatically. Once thought to represent a simple degenerative process, aneurysm tissue is highly active metabolically with ongoing synthesis and degradation of matrix proteins. Several members of a family of matrix-degrading enzymes play an important role in this process. These enzymes can be inhibited by the antibiotic doxycycline.

CONCLUSIONS

With a better understanding of aneurysm pathology, it may be possible in the future to inhibit the growth of small aortic aneurysms before they reach a size at which the risk of rupture is significant.

Effects of the patent false lumen on the long-term outcome of type B acute aortic dissection

OBJECTIVE

To determine the most effective treatment, we performed a detailed comparative study of the clinical course of patients with type B aortic dissection with a patent or thrombosed false lumen who did not undergo surgery in the acute period. We examined the effect of patency of the false lumen on outcome.

METHODS

Computed tomography scans of 138 patients with type B acute aortic dissection were reviewed. Of 138 patients, 110 were medically treated and survived the acute period. We focused on the outcome of these 110 patients, 62 with medically treated thrombosed false lumen (thrombosed group) and 48 with medically treated patent false lumen (patent group). We investigated factors influencing outcome among the 110 patients. The follow-up period was up to 10 years after the onset of aortic dissection. The three study endpoints were death from any cause, dissection-related death (aortic rupture, perioperative death, or death due to organ ischemia), and a dissection-related event (aortic rupture or surgery). In the patent group, we investigated factors influencing long-term outcome.

RESULTS

Patency of the false lumen was an independent risk factor for dissection-related death (P = 0.038, hazard ratio=5.6, confidence interval=1.1-28) and for a dissection-related event (P = 0.000, hazard ratio=7.6, confidence interval=2.7-22) but not for death from any cause (P = 0.769, hazard ratio=1.2, confidence interval=0.45-2.91). In the patent group, location of the most dilated aortic segment at the distal arch was an independent risk factor for dissection-related death (P = 0.026, hazard ratio=13.6, confidence interval=1.4-135) and for a dissection-related event (P = 0.048, hazard ratio=2.6, confidence interval=1.0-6.9).

CONCLUSIONS

Patency of the false lumen is a strong independent prognostic factor for type B aortic dissection. Location of the most dilated aortic segment at the distal arch is a significant risk factor in the patients with a patent false lumen.

Thoracic spondylitis from a mycotic (Streptococcus pneumoniae) aortic aneurysm: a case report

STUDY DESIGN

We report on a 54-year-old man with chronic lower back pain after recent streptococcus pneumoniae pulmonary infection, resulting in a mycotic aortic aneurysm and spondylodiscitis of the eighth vertebrae 6 months later. Successful surgical treatment and recurrence-free survival after 4 years are described.

SUMMARY OF BACKGROUND DATA

Osteomyelitis by Streptococcus pneumoniae of the spine combined with contained rupture of a mycotic aortic aneurysm into lung and spine has not been reported to date. Mycotic aneurysms with pulmonary fistulas are reported to carry a mortality rate of up to 100%. Few cases have been reported with different operative and conservative strategies.

METHODS

The mycotic aortic aneurysm was excised using extracorporeal circulation and replaced by a Dacron graft. The spondylitic section of the eighth thoracic vertebrae was radically resected, and a tricortical bone block from the iliac crest was inserted into the defect. To keep compartments separated, collagen sponges with antibiotic supplementation were used. A triple antibiotic therapy (Metronidazol 3 x 0.5 g/day, Cefotaxim 3 x 2 g/day, and Flucloxacillin 3 x 2 g/day) was prescribed for 6 weeks and changed to Clindamycin for 1 year thereafter.

RESULTS

The patient made a good recovery and is free of recurrence 4 years after surgery.

CONCLUSIONS

Lower back pain might be a projected pain. Particularly in older patients or in the presence of comorbidities resulting in an immunocompromised status, an aggressive workup may be indicated. Radical resection of inflammatory tissues, sparse use of implant material, and prolonged administration of antibiotics proved a successful strategy in this patient.

Use of Continuous Paravertebral Analgesia to Facilitate Neurologic Assessment and Enhance Recovery After Thoracoabdominal Aortic Aneurysm Repair

Neurologic assessment after thoracic aortic aneurysm repair is important for detecting and treating late onset paraplegia. Traditional methods of pain control, such as patient-controlled IV analgesia and epidural analgesia, may interfere with neurologic assessment. We present a case of a patient who received continuous thoracic paravertebral analgesia that provided excellent analgesia while preserving the ability to monitor neurologic function.

IMPLICATIONS

We provided postoperative continuous paravertebral analgesia in a patient after thoracoabdominal aneurysm repair requiring postoperative neurologic assessment. Paravertebral analgesia provides unilateral analgesia with fewer neurologic and hemodynamic side effects than central neuraxial blockade and should be considered for management of patients undergoing thoracic aortic aneurysm repair.

Oxidative stress in the pathogenesis of thoracic aortic aneurysm: protective role of statin and angiotensin II type 1 receptor blocker

OBJECTIVE

The pathogenesis of thoracic aortic aneurysms (TAA) is still unclear. A recent investigation indicated that angiotensin II, a potent activator of NADH/NADPH oxidase, plays an important role in aneurysmal formation. We investigated the potential role of p22phox-based NADH/NADPH oxidase in the pathogenesis of TAA.

METHODS

Human thoracic aneurysmal (n=40) and non-aneurysmal (control, n=39) aortic sections were examined, and the localization of p22phox, an essential component of the oxidase, and its expressional differences were investigated by immunohistochemistry and Western blot. In situ reactive oxygen species (ROS) generation was examined by the dihydroethidium method, and the impact of medical treatment on p22phox expression was investigated by multiple regression analysis.

RESULTS

In situ production of ROS and the expression of p22phox increased markedly in TAA throughout the wall, and Western blot confirmed the enhanced expression of p22phox. The expression was more intense in the regions where monocytes/macrophages accumulated. In these inflammatory regions, numerous chymase-positive mast cells and angiotensin converting enzyme-positive macrophages were present. Their localization closely overlapped the in situ activity of matrix metalloproteinase and the expression of p22phox. Multiple regression analysis revealed that medical treatment with statin and angiotensin II type 1 receptor blocker (ARB) suppressed p22phox expression in TAA.

CONCLUSION

Our findings indicate the role of p22phox-based NADH/NADPH oxidase and the local renin-angiotensin system in the pathogenesis of TAA. Statin and ARB might have inhibitory effects on the formation of aneurysms via the suppression of NADH/NADPH oxidase.

Management of aortic aneurysm infected with Salmonella

BACKGROUND

This study reviewed the clinical outcomes of patients with an aortic aneurysm infected with Salmonella treated by a single centre over 6 years.

METHODS

Data were collected by a retrospective case-note review.

RESULTS

Between September 1995 and December 2001, 121 patients with non-typhoid Salmonella bacteraemia were treated, of whom 24 patients had an aortic aneurysm infected with Salmonella. Ten had a suprarenal and 14 an infrarenal aortic infection. The most common responsible pathogen was group C Salmonella (12 patients). All of the 20 patients who had combined medical and surgical therapy survived, whereas two of four who had medical therapy alone died. There were two late deaths during a mean follow-up of 23 (range 3-63) months.

CONCLUSION

The incidence of aortic infection in patients with non-typhoid Salmonella bacteraemia was high in Taiwan. Timely surgical intervention and prolonged intravenous antibiotic therapy resulted in excellent outcomes.

Comparative study of the natural history and operative outcome in patients 75 years and older with thoracic aortic aneurysm

Surgery for thoracic aortic aneurysm (TAA) in patients 75 years and older is a high risk, but data for their natural history are not available. In the present study the subjects were 62 patients with TAA aged on average 78 years (range, 75-85 years) enrolled between August 1994 and December 2001: 20 operatively treated patients (OPE) and 42 medically managed patients (MED). All of them had been included in the indication for TAA surgery at the time of consultation. Hospital mortality rates and survival rates (Kaplan-Meier method) were compared among emergency OPE, elective OPE, and MED. There were 136 total patient-years of follow-up. Actuarial survival in MED (ie, the natural history) was 83% at 1 year after consultation and 41% at 3 years. Hospital mortality rates in emergency and elective OPE were 27% (3/11) and 0% (0/9), respectively (p=0.22), and the corresponding 3-year survival rates were 44% and 83% (p=0.019). Actuarial survival in elective OPE was higher than that in MED (p=0.022), but that of emergency OPE was similar to that for MED (p=0.17). Patients aged 75 years and older with TAA should undergo an elective operation if the aneurysm diameter is larger than 6 cm and if the patient is asymptomatic and in good anatomicosurgical, physical, and social condition.

Continuous milrinone infusion during preoperative anti-inflammatory therapy in inflammatory aortic aneurysm complicating severe congestive heart failure

We report a 48-year-old man with inflammatory aortic aneurysm in the ascending aorta complicating severe heart failure due to massive aortic regurgitation. Continuous intravenous milrinone infusion was highly effective in reducing pulmonary arterial pressure and improving subjective symptoms during preoperative anti-inflammatory corticosteroid therapy over 7 weeks without any adverse effects or tolerance. Bentall's operation with a valved conduit was successfully performed after complete stabilization of inflammatory markers, and then milrinone was tapered off uneventfully. We consider that continuous milrinone infusion may be suitable for patients with surgically correctable inflammatory cardiovascular diseases complicating severe heart failure in whom maintenance of optimal hemodynamics is necessary for several weeks during preoperative anti-inflammatory corticosteroid therapy.

[Thoracic aortic aneurysm with chronic disseminated intravascular coagulation treated successfully with orally administered camostat mesilate, warfarin and aspirin]

We describe a case of thoracic aortic aneurysm complicated by chronic disseminated intravascular coagulation (DIC). Initially the DIC was controlled successfully by administration of gabexate mesilate and dalteparin. However, because these drugs were given intravenously, the patient could not be discharged. Subsequently, the DIC was treated successfully by changing to orally administered camostat mesilate, warfarin and aspirin, which allowed the patient to leave hospital.

Intra-arterial thrombin injection of an ascending aortic pseudoaneurysm complicated by transient ischemic attack and rescued with systemic abciximab

Thrombin injection as a means of inducing thrombus formation has recently received wide attention as an alternative treatment for pseudoaneurysm. We present a case of a 67-year-old man in whom a large mycotic pseudoaneurysm developed in the ascending aorta because of sternal osteomyelitis and mediastinitis after coronary artery bypass grafting. Transcatheter intra-arterial thrombin injection was performed, and it successfully induced pseudoaneurysm thrombosis. However, the procedure was complicated by a sudden transient ischemic attack caused by thrombus propagation into the cerebral circulation. Complete thrombus dissolution in the cerebral circulation with the resolution of neurologic symptoms was achieved by means of intravenous abciximab.

Aortic aneurysm in patients with autoimmune diseases treated with corticosteroids

BACKGROUND

Aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with autoimmune disorders. The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in those patients treated with corticosteroids.

METHODS

Among 429 patients operated on for abdominal aortic aneurysm during the past 10 years, six patients with autoimmune diseases treated with corticosteroids (one with progressive systemic sclerosis, one with rheumatoid arthritis and four with systemic lupus erythematosus) were reviewed retrospectively. Their data were compared with those of 391 patients with atherosclerotic aneurysms with no autoimmune disorders. The resected aneurysmal walls of the six patients were also compared histopathologically with those of the last six consecutive patients in the control group.

RESULTS

The average age of the patients with autoimmune disease was younger than that of the control group (53.8+/-16.6 vs 71.8+/-7.8 years; p<0.05). Patients with autoimmune disease had received long-term corticosteroid therapy for 15-32 years; mean 22.2+/-6.5 years. Pathological examination showed that the destructive change of the medial elastic lamina in the autoimmune disease group was wider than that in the controls. Most patients had no complications in the postoperative follow-up period (5.1+/-3.2 years), while one patient died of rupture of a dissecting aneurysm two years after operation.

CONCLUSIONS

Prolonged corticosteroid treatment probably plays a major role in the disintegration of connective tissue of the media, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with autoimmune disorders, which can result in aortic aneurysmal enlargement.

Aortic dissection and Turner's syndrome

Cardiovascular malformations, especially coarctation of the aorta and bicuspid aortic valve, are common in patients with Turner's syndrome. Only 46 patients with aortic dissection and/or rupture have been described. All patients had associated aortic dilation or aneurysm. In all cases except three, involvement of the ascending aorta was present, making surgery often imperative. We describe a rare case of a DeBakey type IIIb aortic dissection (without involvement of the proximal aorta) in a patient with Turner's syndrome mosaicism. The dissection occurred two weeks after a caesarean section because of eclampsia. No aortic dilation or other cardiovascular malformations were found. The distal extension and uncomplicated nature of the dissection indicated medical management. After fifteen months of follow-up, she is clinically doing well and repeated CT scan shows a stable dissection of the descending and abdominal aorta without dilation.

Doxycycline inhibits elastin degradation and reduces metalloproteinase activity in a model of aneurysmal disease

PURPOSE

Abdominal aortic aneurysms are characterized by degradation of the extracellular matrix, with a reduction in the elastin concentration of the arterial media. These changes are mediated by increased levels of endogenous metalloproteinases (MMPs) within the aorta, which provide a potential therapeutic target for pharmacologic agents aimed at reducing the growth rate of small aneurysms. In this study, the ability of doxycycline--an MMP inhibitor--to reduce matrix degradation was assessed in a previously described model of aneurysmal disease that used a brief pulse of elastase to induce MMP production and elastin degradation in arterial organ cultures.

METHODS

Porcine aortic segments (n = 8) were preincubated in exogenous pancreatic elastase for 24 hours before culture in standard conditions for 13 days with both 1 and 10 mg/L doxycycline. Control segments were cultured both without doxycycline and without elastase. At the termination of culture, MMPs were extracted from the tissue and quantified by a combination of substrate gel enzymography and immunoblotting. The volume fractions of elastin and collagen were determined by stereologic analysis of sections stained with Miller's elastin and van Gieson's stain.

RESULTS

Stereologic analysis demonstrated a significant preservation of elastin in aorta treated with doxycycline 10 mg/L (p < 0.001) and demonstrated that this preservation was accompanied by a significant reduction in MMP-9 activity (p < 0.02). Immunoblotting for tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) showed no decreased production in the doxycycline-treated groups.

CONCLUSIONS

Therapeutic ranges of doxycycline significantly inhibited elastin degradation and MMP-9 production within aortic organ cultures. These data suggest that doxycycline may have a potential application in reducing the growth rates of small abdominal aortic aneurysms.

Successful management of acute aortic dissection in a heart transplant recipient

A case of type III aortic dissection which occurred fourteen months after heart transplantation is presented. Medical therapy was instituted to achieve controlled hypotension. The evolution was favorable and the patient could be discharged after one month. Hypertension and increased ejection fraction after transplantation could have been predisposing factors via an increase of the shear stress in the aorta.

[Aneurysm of the ascending aorta in tertiary syphilis]

HISTORY AND CLINICAL FINDINGS

A 58-year-old man was admitted after he was found to have a huge aneurysm of the thoracic aorta. 38 months previously he had first experienced subacute pain in the right thorax. After this the aneurysm gradually increased in size. On admission a pulsating mass, 20 cm in diameter, was obvious, having broken through the right ventral thoracic wall. It was causing venous inflow congestion in the upper part of the body. The patient's general condition was poor: he had marked orthopnoea.

INVESTIGATIONS

Serological tests for syphilis gave the following results: VDRL test, 1:32; FTA-ABS test reactive; TPHA test, 1:8000; treponema-specific IgM negative. Computed tomography with contrast-medium injection exactly defined site and extent of the aneurysm. It started at the aortic root and extended to the aortic arch. Third-degree aortic valvar regurgitation was demonstrated on echocardiography. Pulmonary function tests indicated severe restrictive ventilatory abnormality with clearly reduced respiratory reserve.

TREATMENT AND COURSE

The symptoms improved after 2 weeks on oral medication of captopril (25 mg/d), furosemide (80 mg/d), spironolactone (100 mg/d), codeine phosphate (90 mg/d) and thick paraffin (20 mg/d as needed). The patient declined further treatment. He died 8 weeks later at home.

The use of 25% glutaraldehyde solution to strengthen the aorta of patients with annuloaortic ectasia, ascending and aortic arch aneurysms

Aortic friability is a problem of great concern and frustration for those performing operations on patients with ascending and arch aortic aneurysms, and particularly, on patients with annuloaortic ectasia. We have used 25% glutaraldehyde to successfully strengthen the distal aorta of three such patients. After the application, the aorta wall held sutures without tearing. Postoperative bleeding was minimal in each case. No neurological events were noticed, and all of the patients were discharged home within 2 weeks. The application of this tanning solution to such a friable aortic tissue should be considered as a helpful alternative to reduce postoperative bleeding, which is the most common complication after this type of surgery.