Comparison of endovascular and conventional vascular prostheses in an experimental infection model

In situ Reconstruction with Autologous Veins for the Treatment of Infected Abdominal Endografts: Single Center Experience

Background: Vascular graft infection is a feared complication with high mortality and morbidity rates. Complete excision with in situ repair is recommended. We report our experience with patients suffering of abdominal aortic endograft infection undergoing excision and in situ reconstruction with autologous vein. Patients and Methods: All patients who underwent excision of an abdominal aortic endograft and in situ reconstruction with autologous superficial femoral veins between April 2005 and June 2021 were retrospectively reviewed. Primary outcome measures were mortality and reinfection. Secondary outcome measure was patient morbidity. Results: Fifteen patients (14 male; 93%) were included. Twenty percent of the index procedures (N = 3) were performed at our hospital, 80% (N = 12) were referred patients. Three aorto-enteric fistulae were seen. Staphylococci and enterococci were the most common pathogens (N = 8; 53%). In two out of six patients (33%) with an endograft with suprarenal fixation, the suprarenal fixation stent was left in situ. 30-day mortality rate was 6.6% (N = 1). Median follow-up time was 12 months (range 0-85). During follow-up, no reinfection was seen. Serious morbidity was witnessed in 2 patients (sepsis due to bowel leakage (N = 1), pneumonia (N = 2), hemodialysis (N = 1)). Eventration was the most common late morbidity observed (N = 5). Conclusions: Surgical treatment of vascular abdominal endograft infection by in situ reconstruction with autologous deep vein is a challenging procedure. If a multidisciplinary approach is applied and patients are centralized in experienced centers, acceptable mortality and morbidity rates can be achieved.

Mycotic Aneurysm of the Common Iliac Artery and Distal Aorta Following Stent Placement

A 43-year-old man was evaluated for disabling left leg claudication. Aortography demon strated occlusion of the left common and external iliac arteries with reconstitution of the left common femoral artery. During this procedure a 10 mm x 9.4 cm Wallstent was placed from the proximal common iliac to the mid-external iliac artery followed by a 10 mm Palmaz stent placed proximal to the Wallstent. He returned after 2 weeks with recurrent symptoms and an absent left femoral pulse. Repeat aortography confirmed that the stented iliac artery was thrombosed. Following thrombolysis, a stenosis distal to the Wallstent was identified and another 8 mm x 4 cm Wallstent was inserted to dilate the stenotic lesion. He did well until the following week when he returned complaining of fever, anorexia, and low back pain. Staphylococcus aureus was cultured from the blood. An initial computed tomography (CT) scan demonstrated only inflammation around the distal aorta, but owing to unremitting fever and symptoms, he underwent another CT scan 4 days later, which demonstrated a large aneurysm of the distal aorta and left common iliac artery. The patient was taken to the operating room where a right-to-left femorofemoral bypass was performed. After the groin wounds were closed, an exploratory laparotomy disclosed a large mycotic aneurysm of the distal aorta and proximal left common iliac artery. The aorta was oversewn below the level of the inferior mesenteric artery (IMA) and the Palmaz and proximal Wallstent were removed. An IMA thrombec tomy was performed because no Doppler flow was present in the sigmoid mesentery. Following abdominal closure, a right axillofemoral graft and thrombectomy of the femo rofemoral graft were performed. On postoperative day 12, he developed an ileus and signs of sepsis. Upon reexploration, a sigmoid perforation was discovered and a sigmoid resection and colostomy were performed. He was treated with parenteral antibiotics and enteral nutrition and was transferred for continued rehabilitation 8 weeks later.

Diagnostic Options in Assessing Abdominal Aortic Endograft Infection

Endovascular treatment of aortic aneurysms has gained widespread popularity in recent years. Stent grafts have emerged as another option in the surgeon's armamentarium in the treatment of aneurysmal disease. The infectivity of endovascular grafts and therapy for associated graft infections is unknown. Aortic graft infections have the potential for disastrous complications. This report presents a 72-year-old woman with persistent fever and an infected aortic stent graft in the early postoperative period.

Endovascular Graft Infection: Preliminary Results of an International Enquiry

Purpose:

To investigate the frequency of aortoiliac endovascular graft infections and seek the main factors influencing their development.

Methods:

To augment personal experience (1 case), a questionnaire was sent to 40 international centers of vascular and endovascular surgery. The literature was also reviewed to collect data on infections developing in endovascular grafts.

Results:

The survey (85% response rate) and literature review identified 62 cases of infected endovascular grafts (0.4% frequency of endograft infection). In 22 (35%) patients, the infection manifested initially with vague symptoms only, but 41 (65%) patients eventually presented with abdominal abscess, groin fistula, and septic embolization. Common bacteria, such as Staphylococcus aureus, were identified as the cause of most infections (54.5%). The majority (49, 79%) of the 62 patients were treated surgically; 11 (17.7%) patients received conservative therapy (no therapeutic data in 2 patients). Overall mortality was 27.4% (17/62), and operative mortality was 16.3% (8/49). Conservative treatment led to a mortality rate of 36.4% (4/11). The mean follow-up for all patients was 47.8 weeks. Possible factors influencing the development of an infection were secondary adjunctive procedures, immunosuppression, treatment of false aneurysms, and infected central lines.

Conclusions:

Infected endovascular grafts are an urgent problem that has been heretofore underestimated and will probably increase as follow-up lengthens. New techniques should be sought to expedite the diagnosis, and an international registry should be set up to provide validated data.

A Case Report on the Successful Treatment of Streptococcus pneumoniae-Induced Infectious Abdominal Aortic Aneurysm Initially Presenting with Meningitis

Infectious abdominal aortic aneurysms often present with abdominal and lower back pain, but prolonged fever may be the only symptom. Infectious abdominal aortic aneurysms initially presenting with meningitis are extremely rare; there are no reports of their successful treatment. Cases with Streptococcus pneumoniae as the causative bacteria are even rarer with a higher mortality rate than those caused by other bacteria. We present the case of a 65-year-old man with lower limb weakness and back pain. Examination revealed fever and neck stiffness. Cerebrospinal fluid showed leukocytosis and low glucose levels. The patient was diagnosed with meningitis and bacteremia caused by Streptococcus pneumoniae and treated with antibiotics. Fever, inflammatory response, and neurologic findings showed improvement. However, abdominal computed tomography revealed an aneurysm not present on admission. Antibiotics were continued, and a rifampicin soaked artificial vascular graft was implanted. Tissue cultures showed no bacteria, and histological findings indicated inflammation with high leukocyte levels. There were no postoperative complications or neurologic abnormalities. Physical examination, blood tests, and computed tomography confirmed there was no relapse over the following 13 months. This is the first reported case of survival of a patient with an infectious abdominal aortic aneurysm initially presenting with meningitis caused by Streptococcus pneumoniae.

How To Diagnose and Manage Infected Endografts after Endovascular Aneurysm Repair

The prevalence of endograft infections (EI) after endovascular abdominal aortic aneurysm repair is below 1%. With the growing number of patients with aortic endografts and the aging population, the number of patients with EI might also increase. The diagnosis is based on an association of clinical symptoms, imaging, and microbial cultures. Angio-computed tomography is currently the gold-standard technique for diagnosis. Low-grade infection sometimes requires nuclear medicine imaging to make a correct diagnosis. There is no good evidence to guide management so far. In the case of active gastrointestinal bleeding, pseudoaneurysm, or extensive perigraft purulence involving adjacent organs, an invasive treatment should always be attempted. In the other cases (the majority), when there is not an immediate danger to the patient's life, a conservative management is started with a proper antimicrobial therapy. Any infectious cavity can be percutaneously drained. Management depends on the patient's condition and a tailored approach should always be offered. In the case of a patient who is young, has a good life expectancy, or in whom there is absence of significant comorbidities, a surgical attempt can be proposed. Surgical techniques favor, in terms of mortality, patency, and reinfection rate, the in situ reconstruction. Choice of technique relies on the center and the operator's experience. Long-term antibiotic therapy is always required in all cases, with close monitoring of the C-reactive protein.

Infection of endovascular abdominal aortic aneurysm stent graft after urosepsis: case report and review of the literature

Infection of endovascular abdominal aneurysm stent grafts is an uncommon but known complication. Inoculation with bacteria of the endovascular abdominal aneurysm stent graft during the actual implantation, in the periprocedural hospitalization or later due to an aortoenteric fistula, has been described in the literature. We report a case of endovascular abdominal aortic aneurysm stent graft infection occurring 40 months after implantation in a patient doing well up to an episode of urosepsis. In conclusion, we postulate that poor intraluminal healing of stent grafts, as observed in several explant studies, may result in a higher susceptibility to episodes of bacteremia than prosthetic vascular grafts inserted during open repair. We therefore consider the administration of prophylactic antibiotics in patients with endovascular stent grafts during periods with a likelihood of bacteremia.

Gram-negative groin sepsis treated with covered stents and systemic antibiotics

Prosthetic graft infections are hazardous conditions. Those due to Gram-negative bacteria are particularly serious. When Gram-negative microorganisms are present, entire graft excision is recommended, with revascularization if needed, preferably with autogenous tissues or with prosthetic grafts via non-infected planes if autogenous options are not available. We herein report the case of a diabetic man with critical limb ischemia, who after lower-extremity revascularization with a prosthetic graft, developed an early graft infection due to Gram-negative and fungal organisms, and who was successfully treated with a covered stent placed across grossly infected tissues. A discussion on the pertinent literature is also offered.

Infecção em endoprótese

A infecção envolvendo endopróteses é uma complicação pouco frequente, associada a elevadas taxas de mortalidade. A apresentação clínica é geralmente tardia, podendo variar de sintomas inespecíficos até complicações graves como pseudoaneurisma e fístula aortoentérica. O diagnóstico envolve alto índice de suspeição e investigação com exames de imagem e laboratoriais. O tratamento segue os preceitos da infecção de prótese em cirurgia convencional, indicando-se, para a maioria dos pacientes, a excisão cirúrgica acompanhada da revascularização in situ ou extra-anatômica. O tratamento conservador fica reservado para casos selecionados.

Down Syndrome: A Risk Factor For Mycotic Aneurysm?

Down syndrome, or trisomy 21, has a characteristic constellation of clinical findings, including various congenital heart defects. We report a case of an adult male with Down syndrome who presented with a 3-week history of lower limb pain and swelling, attributed to cellulitis. Clinical and angiographic evaluation identified a below-knee mycotic pseudoaneurysm secondary to infective endocarditis. Surgical aneurysmal repair and revascularization were performed. Various management options are outlined in this report.

Late Infection of an Endovascular Stent Graft with Septic Embolization, Colonic Perforation, and Aortoduodenal Fistula

We report on a 52-year-old male who developed late stent graft infection resulting in infective aneurysm formation with systemic septic embolization and aortoduodenal fistulation 9 months following endoluminal repair of an abdominal aortic aneurysm. Although endoluminal stent graft infection and erosion into surrounding viscera is rare, we highlight the need for awareness of this potentially catastrophic complication.

Aortoiliac stent graft infection: current problems and management

Aortic stent graft infection is uncommon. Most cases have been described anecdotaly in single-case reports. After observing one case in our experience, we decided to review the literature and contact centers performing endovascular aortic repair to determine the frequency, risk factors, and current treatment of stent graft infection. The literature was reviewed and the authors of identified articles were contacted for further information. In addition, 40 centers specializing in endovascular treatment were contacted by means a dedicated questionnaire. A total of 65 aortic stent graft infections were identified, including 43 reported cases and 22 previously unpublished cases that were observed at specialized centers. Stent grafts were implanted in the aorta in 50 cases and in the iliac artery in 15 cases. The frequency of infection was 0.43%. The gender ratio was 4:1 (M:F). Twenty-three percent of patients had immunodeficiency factors. Placement was performed in an interventional radiology suite in 62.5% of cases and in a sterile operating theater in 37.5%. Also, 35.5% of patients underwent other vascular procedures during the course of study and 29.2% stent grafts benefited from adjuvant endovascular procedures. Infection was classified as low grade in 35.4% of patients and high grade in 64.6%. Thirty-one percent of infections were associated with aortoenteric fistula. The offending microorganism was Staphylococcus aureus in 54.5% of cases. Treatment was conservative in 18% of cases and surgical in 82%. Surgical treatment consisted of stent graft removal followed by either extraanatomical bypass (59.5%) or in situ prosthetic reconstruction (40.5%). Mortality was 18% overall, 36.4% after conservative treatment and 14% after surgical treatment ( p = 0.083). Mortality was 16% after surgical treatment with extraanatomical bypass vs. 5.8% surgical treatment with in situ reconstruction. From these results we conclude that stent graft infection is an uncommon occurrence associated with poorly defined risk factors. Surgical treatment with complete excision of the infected stent graft followed by in situ reconstruction provides the best outcome. Establishment of a multicenter register to record such complications is needed to confirm the findings of this study.

Mycotic aneurysm of the abdominal aorta with retroperitoneal abscess: Successful endovascular repair

Mycotic aortic aneurysms are rare. Improved diagnostic procedures, appropriate antibiotic treatment, and safe surgical techniques have reduced the high mortality associated with bacterial aortitis. However, definite evidence-based conclusions with regard to the surgical strategy cannot be drawn from the data available in the published literature. We report successful endovascular repair of a mycotic abdominal aortic aneurysm. Endovascular treatment may offer a benefit, especially in critically ill patients.

Endograft infection leading to rupture of aortic aneurysm

Aortic endografting has quickly been accepted as a less morbid method of aneurysm repair. However, preservation of the aortic sac after endografting remains a liability of this procedure. Late rupture has occurred, albeit rarely. Graft infections are another rare complication of endografting. We present the first reported case, to our knowledge, of aortic rupture secondary to infection of an aortic endograft.

Percutaneous Drainage and Explantation of an Infected Aortic Endoluminal Stent Graft

Endoluminal repair of abdominal aortic aneurysms (AAAs) has undergone explosive growth in the last decade. Although immediate benefits are attractive to both the patient and the treating physician, concerns regarding long-term success have dampened sustained enthusiasm for this technique. A rare but catastrophic complication is stent graft infection. This case report describes an early infection of an endoluminal aortic stent graft treated initially with percutaneous drainage and ultimately with staged extraanatomic bypass and graft explantation.

Prophylactic antibiotics prior to bacteremia decrease endovascular graft infection in dogs

Endovascular placement of vascular stent grafts in the aorta and peripheral vessels has become a prominent tool in the armamentaria of the vascular surgeon. Despite, several reports of stent graft infection, no current guidelines exist regarding the administration of antibiotics prior to episodes of potential bacterial seeding. We sought to clarify the role of prophylactic antibiotics in preventing stent graft infection after the parenteral administration of Staphylococcus aureus (S. aureus) at various intervals following device placement. A stent graft device was constructed from a 4 mm thin-walled polytetrafluoroethylene (PTFE) graft attached to the outside of a balloon expandable 394-Palmaz stent (Johnson and Johnson Interventional Systems, Warren, NJ). It was then inserted into the common iliac artery through an 11F peal-away sheath placed in the femoral artery. Sixty grafts were placed into 30 dogs. There were 5 groups of equal number (groups A-E). In group A, six dogs received intravenous injection of 3 cc x 104 CFU (colony forming units), biotype 31375 S. aureus, 1 day after stent graft implantation. An identically treated group B received antibiotic prophylaxis (1 gm cefazolin 30 minutes prior to bacterial challenge). Group C received bacterial injection 7 days after graft implantation with no antibiotic prophylaxis. Group D received bacterial injection 7 days after graft implantation with antibiotic prophylaxis. A control group E received no antibiotics and was not infected. All infected animals were sacrificed 7 days following bacterial challenge and the stent graft complex cultured. One half of the control group was sacrificed at 7 days and the other half at 14 days. The overall stent graft patency was 90%. Four of the six graft occlusions occurred in group A. Eleven of 12 (92%) dogs cultured S. aureus (biotype 31375) from the explanted stent graft complex. Two localized perforations occurred at the site of the infected complex. In group B, C, and D, no explanted graft complex cultured S. aureus. One graft occluded in group C and D. No stent graft in the control (group E) cultured S. aureus. A stent graft infection model can be consistently produced. In the canine model, the stent graft is more susceptible to infection in the early postoperative period and becomes less susceptible to bacterial seeding at one week after implantation. The authors recommend the use of prophylactic antibiotics in the prevention of endovascular graft infections in the early postoperative period during times when bacterial seeding may occur. They postulate that pseudointima formation during graft incorporation into the vessel wall may be responsible for the resistance to infection.

Stent graft repair for rupture of the subclavian artery secondary to infection of a subclavian-to-carotid bypass graft

The case of anastomotic rupture of the subclavian artery following infection of a subclavian-to-carotid bypass grafting is reported. Emergency endoluminal stent graft repair was life saving and aided wound healing, but stent graft thrombosis occurred. Such a complication raises some concern about the safety of this procedure in an infected setting. The use of autologous saphenous vein-covered stent graft may provide some advantages in avoiding graft infection and thrombosis.

Successful management of tracheo-innominate artery fistula with endovascular stent graft repair

Tracheo-innominate artery fistula is a highly lethal complication after tracheostomy. A 37-year-old man who had undergone a tracheostomy 14 years earlier because of dysphagia after brain surgery had a tracheo-innominate artery fistula with exsanguinating hemorrhage from his tracheostomy site. After temporary control of the bleeding, a stent graft was implanted in the innominate artery through the brachial artery. The patient recovered uneventfully and remained well 14 months after the procedure, with no sign of infection. Endovascular stent grafting may be the treatment of choice for patients with tracheo-innominate artery fistula.

Endoluminal femoropopliteal bypass for intermittent claudication

OBJECTIVES

(i) to describe our initial clinical experience with endoluminal femoropopliteal bypass using a technique developed in a cadaveric model; (ii) to identify areas requiring technical modification to improve patency and complication rates.

DESIGN

prospective, experimental pilot study.

MATERIALS AND METHODS

fourteen consecutive patients with disabling intermittent claudication and superficial femoral artery occlusion underwent endarterectomy through a groin incision and endoluminal placement of a polytetrafluoroethylene graft. Follow-up was by duplex ultrasound and arteriography.

RESULTS

two endovascular technical failures required conversion to open surgery. The cumulative primary (1 degrees), 1 degrees-assisted and secondary (2 degrees) patency rates at 1 year were 35.7%, 42.8% and 71.4% respectively; at 2 years the patency rates were 14.3%, 31.2% and 57.1%. Twenty-three endovascular interventions were required to maintain graft patency in 10 patients. Five patients subsequently required conventional bypass, of whom two proceeded to major amputation because of graft infection. Seven endovascular grafts remain patent at a mean follow-up of 50 months.

CONCLUSIONS

this minimally invasive surgical technique is feasible, with acceptable patency rates. However, considerable investment of time and resources is required to maintain graft patency. With increasing experience and improved technical design, this procedure may offer a real alternative to conventional surgery in patients disabled by short-distance claudication.

Endovascular stent graft repair of aortopulmonary fistula

Two patients who had aortopulmonary fistula of postoperative origin with hemoptysis underwent successful repair by means of an endovascular stent graft procedure. One patient had undergone repeated thoracotomies two times, and the other one time to repair anastomotic aneurysms of the descending aorta after surgery for Takayasu's arteritis. A self-expanding stainless steel stent covered with a Dacron graft was inserted into the lesion through the external iliac or femoral artery. The patients recovered well, with no signs of infection or recurrent hemoptysis 8 months after the procedure. Endovascular stent grafting may be a therapeutic option for treating patients with aortopulmonary fistula.