Endovascular stent infection

Late onset infection of covered and bare metal arterial stents

OBJECTIVE

The objective was to present the case of a late covered iliac stent late infection and report a comprehensive literature review on diagnosis and outcomes in this setting.

METHODS

A comprehensive review of the literature was performed through MedLine by two independent reviewers from 1990 to 2020 on reported cases of arterial stent late onset infection over arterial stents. The data about on the risk factors, clinical presentation, treatment and outcomes were collected.

RESULTS

Twenty-two studies were selected as pertinent for the analysis, totalling 24 patients including the indexed case. Infection occurred at a median of 22 months postoperatively (range 2-120 months) over a bare metal stent in 66.7% (n 16) of cases versus 33.3% (n 8) over a covered stent. Clinical presentation included local symptoms (local pain, oedema, petechiae or skin rash) in 21 (87.5%) cases and non-specific systemic symptoms (fever, sepsis, chills and leucocytosis) in 8 cases (33.3%). In 4 cases (16.7%), patients presented with haemorrhagic shock upon arterial rupture. The bacteria most frequently encountered were S. aureus (54.2% of cases). Several factors were supposed to be responsible for the infection including among which procedure-related (non-aseptic technique, lack of prophylactic antibiotics and repetitive punctures at the access site) or related to pre-existing patient's clinical conditions (immunosuppression, diabetes and concurrent infection) have been considered responsible for the infection. Treatment consisted in antibiotics alone (2 patients, 8.3%) or in association with surgical explant, both with or and without revascularization (n 21, 87.5%). In one case, an endovascular coiling was performed. Complications occurred in 29.2% (n 7) of cases and included the need for amputation, bowel resection, endocarditis, pulmonary failure or pneumonia. Overall, three patients (12.5%) died from a septic shock or multi-organ failure.

CONCLUSIONS

Intravascular stent infection is a rare but fearsome condition associated with high morbidity and mortality.

Endoleak and Pseudoaneurysm Formation in the Setting of Stent Graft Infection Following Endovascular Uretero-Arterial Fistula Repair: The Dreaded Complication

The complication of uretero-arterial fistula after prolong ureteral stenting is well recognized. The treatment is primarily endovascular stenting across the fistulous communication accepting the potential risk of stent graft infection. Herein we present a case of a 71-year-old female who developed an uretero-arterial fistula after prolong ureteral stenting and exchanges following ileal conduit obstruction. Initial treatment with left common iliac stenting controlled the hematuria, but only temporarily. Repeat angiography revealed a type 1b endoleak requiring stent extension. Unfortunately, persistent hematuria necessitating further angiography showed the development of a saccular pseudoaneurysm around the stent graft requiring proximal stent extension. A nuclear medicine indium 111-tagged white blood cell scan with single-photon emission CT (SPECT)/CT confirmed stent graft infection. Conservative therapy with antibiotics failed, causing graft failure that ultimately required bypass surgery.

First case report of sepsis caused by Rhizobium pusense in Japan

Introduction

Species of the genus Rhizobium are opportunistic, usually saprophytic, glucose-non-fermenting, Gram-negative bacilli found in agricultural soil. Rhizobium pusense infections are the least common Rhizobium infections and have low incidence.

Case presentation

Herein, we report the first case of sepsis with R. pusense in Japan in a 67-year-old Japanese woman with a history of hyperlipidaemia, hypertension, diabetes, hypothyroidism and osteoporosis. She had undergone cerebrovascular treatment because she was diagnosed with a subarachnoid haemorrhage. The results of postoperative blood culture showed oxidase-positive, urease-positive, non-lactose-fermenting Gram-stain-negative rods. Using the Vitek2 system, the isolate was distinctly identified as Rhizobium radiobacter. However, 16S rRNA gene sequencing showed 99.93 % similarity with the type strain of R. pusense and 99.06 % similarity with the type strain of R. radiobacter. Additional gene sequencing analysis using recA (97.2 %) and atpD (96.2 %) also showed that the isolated strain is most closely related to R. pusense. The patient was cured by treatment using intravenous meropenem (3 g/d) for 4 weeks and was discharged safely.

Conclusion

The definite source of sepsis was unknown. However, the possibility of having been infected through the catheter during the cerebrovascular operation was speculated.

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.

Stent-Related Iliac Artery and Iliac Vein Infections: Two Unreported Presentations and Review of the Literature

Purpose:

To discuss the presentation, diagnosis, and treatment of stent-related infections on the basis of 2 new cases and historical review.

Case Reports:

Two previously unreported cases of vascular stent infection are presented with a summary of cases from the literature. One case involved an iliac artery stent infection secondary to a remote bacteremia 6 months after stent placement. The other case was an early iliac vein stent infection, a previously unreported site of this complication. Both cases were diagnosed by use of computed tomography and were treated surgically after medical management failed. Both patients survived.

Conclusions:

A high index of suspicion is necessary for the diagnosis of stent infections, and an aggressive treatment is usually necessary for survival. Prophylactic antibiotics should definitely be considered in cases involving repeat interventions and prolonged catheterization, as well as before bacteremia-inducing therapies.

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.

Infections of intravascular bare metal stents: a case report and review of literature

OBJECTIVE

The objective of the paper is to present a case of an infected bare metal stent in the left common iliac artery that was removed by an urgent operation, and to review the literature on diagnosis and outcome of infected coronary and non-coronary metal stents.

METHODS

A systematic search of the Medline database was performed with the purpose of identifying risk factors, signs and symptoms, imaging strategies, and treatment modalities of bare metal stent infections, both coronary and peripheral.

RESULTS

In total, 76 additional studies/case reports (48 non-coronary; 29 coronary) were included and analyzed. Intravascular bare metal stent infections are a rare but serious complication, often leading to emergency surgery (overall: 75.3%; non-coronary cases: 83.3%; coronary cases: 62.1%). In 25.0% of the non-coronary cases, infection led to amputation of an extremity or removal of viscera. Reported mortality was up to 32.5% of the cases (non-coronary: 22.9%; coronary 48.3%). Physicians should always be suspicious of a stent infection when patients present with aspecific symptoms such as fever and chills after stent placement. Additional imaging can be used to detect the presence of a pseudoaneurysm. A PET-CT is an ideal medium for identification of a stent infection.

CONCLUSIONS

Intravascular stent infection is associated with a high risk of morbidity and mortality. Surgery is the preferred treatment option, but not always possible, especially in patients with a coronary stent. In selected cases, bare metal stent infections may be prevented by the use of prophylactic antibiotics at stent placement.

Infection of an aortic stent graft with suprarenal fixation

We report a case of an elderly man admitted with abdominal pain and fever, 5 months after endovascular aortic aneurysm repair of a suspected inflammatory abdominal aortic aneurysm. He underwent successful explantation of an infected stent graft with suprarenal fixation following extra-anatomic revascularization. After a prolonged hospitalization, he was discharged on antibiotics and at follow-up has returned to baseline activity level. Although explantation of an infected prosthesis following endovascular aortic aneurysm repair has been previously reported, our case prompted a review of the literature to evaluate mode of presentation, putative factors, and management decisions associated with reduced morbidity and mortality.

The current state of endovascular therapy in the evaluation and management of renovascular disease

Hypertension is the most common reason for physician office visits among nonpregnant adults in the United States; up to one-third of Americans over the age of 18 have been diagnosed with hypertension. Patients with physiologically significant renal artery stenosis often go unnoticed because hypertension can often be well controlled with antihypertensive medications. As a result, screening for renovascular causes of hypertension is rarely done. However, the likelihood of renovascular disease increases in patients with acute, severe, or refractory hypertension and should be explored in patients who fall into these categories. Renovascular disease is a crucial consideration in the management of hypertension due to its increasing incidence and its potential for reversibility. Although renovascular disease accounts for less than 1% of patients with mild hypertension, it is estimated that between 10 and 45% of white patients with severe or malignant hypertension have renal artery stenosis (RAS). In this population, diagnosing and treating RAS can have a profound and long-lasting effect on the treatment of hypertension.

Percutaneous recanalization of the occluded iliac artery: examples, techniques, and complications

Recanalization of an occluded iliac artery represents a technically challenging endovascular technique. Prior to attempting recanalization, the operator must have an approach in mind and understand the risks and complications associated with this endeavor. In this article, the authors provide 2 cases and review the techniques and complications associated with iliac artery recanalization.

Bare metal stent infections: Case report and review of the literature

Infection of bare metal stents in the vasculature is rare, but associated with significant morbidity and mortality. We report two cases of bare metal stent infections and review the literature regarding infected bare metal stents with respect to risk factors, pathophysiology, diagnosis, treatment, and prevention. Overall, this article highlights the need to have a high index of suspicion of bare metal stent infection, since prompt diagnosis and treatment can ultimately decrease the morbidity and mortality associated with this devastating problem.

Antibiotic Prophylaxis in Interventional Radiology—Anything New?

Every interventional procedure can result in infective complications. Generally the incidence is low; however, with newer and more aggressive techniques the infection risk is more prevalent and can result in serious adverse outcomes to our patients. Antibiotic prophylaxis has become commonplace; however, there is little controlled data to underpin our regimens and most choices are based on surgical practice and anecdotal evidence. The rise of antibiotic resistance and treatment of many immunocompromised patients further compounds the difficulties faced. The purpose of this article was to examine the evidence that is presented regarding antibiotic prophylaxis in interventional radiology and highlight how we integrate this into our daily practice. In particular we will focus on evolving procedures and techniques that are associated with a high incidence of infection.

MRSA-infected external iliac artery pseudoaneurysm treated with endovascular stenting

A 48-year-old woman with severe juvenile-onset rheumatoid arthritis presented with a bleeding cutaneous sinus distal to her right total hip replacement scar. Methicillin resistant Staphylococcus aureus (MRSA) was isolated on culture. She had previously undergone bilateral total hip and knee replacements at aged 23 and six years later had the right knee prosthesis removed for infection, with subsequent osteomyelitis of the femoral shaft and right total hip prosthesis disruption. Peripheral arteriography was performed in view of persistent bleeding from the sinus, which revealed a 6 cm false aneurysm filling from and compressing the right external iliac artery (EIA). A PTFE-covered, balloon expandable JOSTENT was deployed in the right EIA, successfully excluding the false aneurysm and preventing further bleeding from the sinus. No graft infection was reported at 12 months. This case illustrates the potential use of endovascular stent-grafting in the treatment of an infected pseudoaneurysm.

Fatal subclavian stent infection remote from implantation

We report the unusual case of a 66-year-old alcoholic male who presented with acute arm ischemia 4 months following ipsilateral subclavian artery stenting. The patient had a petechial rash and Janeway lesions in the distribution of the affected subclavian artery. He had been treated for an infected dialysis graft 10 days prior to entry into the hospital. Subsequent angiogram confirmed a patent stent with intraluminal filling defects and occlusion of the brachial artery. Thrombectomy yielded material that was consistent with septic emboli and CT scan of the chest was suggestive of a mycotic aneurysm around the stent. The subclavian stent was removed surgically and the aneurysm was repaired. Unfortunately, the patient had multiple comorbidities and died of complications during recovery. This is the first case of a subclavian stent infection following septicemia remote from implantation.

Chemical Meningitis after Cerebral Aneurysm Treatment Using Two Second-generation Aneurysm Coils: Report of Two Cases

OBJECTIVE AND IMPORTANCE:

In the quest for effective and durable endovascular aneurysm treatment, second-generation aneurysm coils endeavor to increase the biological healing response to the implanted material. We report two cases of large cerebral aneurysms treated concurrently with both available second-generation aneurysm coils and the subsequent development of symptomatic nonbacterial meningitis.

CLINICAL PRESENTATION:

Two previously healthy patients underwent endovascular treatment for large (≥2 cm) cerebral aneurysms. Both aneurysms were treated using multiple Hydrogel coils (MicroVention, Inc., Aliso Viejo, CA) and Matrix coils (Boston Scientific/Target, Fremont, CA). Careful aseptic technique was observed throughout each procedure, and prophylactic intravenous antibiotics were administered during the perioperative period to both patients. Treatment proceeded uneventfully in both cases with excellent aneurysm occlusion and no immediate postoperative neurological deficits.

INTERVENTION:

In both cases, the patients were discharged from hospital but quickly were readmitted with stigmata of meningitis. Imaging demonstrated durable occlusion of the aneurysms in both patients and also abnormalities indicative of perianeurysmal and diffuse intracranial inflammatory response. Complete septic workup failed to identify an organism in either patient. Both patients responded to treatment with corticosteroid medication used to modulate the inflammatory response induced by the coil implants.

CONCLUSION:

Second-generation aneurysm coils were developed to promote more durable occlusion of cerebral aneurysms by promoting more complete volumetric aneurysm occlusion or by eliciting a more prolific inflammatory response. The concurrent use of Hydrogel and Matrix coil systems in large aneurysms may cause an exuberant inflammatory response with both local and systemic manifestations. Although vigilant evaluation and treatment for presumptive bacterial meningitis is required in all such cases, patients respond to immunomodulatory therapy with corticosteroids. More information to understand better the interaction of Hydrogel and Matrix coils is needed.

Antibiotic prophylaxis in interventional radiology

Despite several decades of advances in both minimally invasive techniques and antibiotic therapy, infection remains one of the more common complications of invasive procedures. Interventional radiology (IR) has traditionally been believed to be associated with lower infection rates than surgery. However, new interventional techniques, as well as more aggressive therapeutic interventions, have presented new challenges in relation to pharmacological management of postprocedural infection and pain. The risk of infection associated with IR procedures can never be completely eliminated, and the reasons for this are manifold, including more virulent organisms, ongoing and newly emerging antibiotic resistance, increased numbers of immunocompromised patients, and the adoption into everyday interventional practice of more aggressive interventional techniques such as chemoembolization, uterine fibroid embolization, and complex biliary intervention. Despite the widespread use of prophylactic antibiotics in IR, and the widely held belief that they are beneficial and are the standard of care, randomized controlled clinical trials have never validated the use of antibiotics in this setting. As such, an argument could be made not to use antibiotics at all for prophylaxis in IR. The purpose of this article is to discuss some of the issues relating to the use of prophylactic antibiotics, and what choice of antibiotics physicians make when they decide to use prophylaxis for IR procedures.

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.

Infected endovascular graft secondary to coil embolization of endoleak: a demonstration of the importance of operative sterility

A 60-year-old male underwent endovascular repair of a 5.4-cm enlarging abdominal aortic aneurysm with intraoperative recognition of a type I endoleak. The endoleak was demonstrated to be arising from the left limb of the bifurcated prosthesis. An intravascular stent was placed in the limb near the origin of the common iliac artery and it appeared that the endoleak had sealed. However, 1 month after operation a CT scan demonstrated a persistent, substantial size endoleak without aneurysm enlargement. Coil embolization of the endoleak was undertaken in the interventional radiology suite with apparent satisfactory result. Four days after embolization the patient developed abdominal pain and after 8 days fever and leukocytosis developed. Two weeks after embolization an abdominal CT and indium scan revealed an infected endovascular graft. By CT, the posterior wall of the aneurysm was destroyed and a peri-graft fluid collection with gas was present at the location of the coils. The patient was treated with graft and coil excision and autologous vein reconstruction. Endoluminal prostheses can be contaminated at the time of operative placement. However, an additional source of endoluminal graft infection can arise from secondary endovascular procedures for endoleaks and other graft complications. Since we began placing endovascular grafts at our institution in 1993, most coil embolizations have been performed in the interventional radiology suite. This experience of coil-induced infection causes us to consider performing this type of secondary intervention in the operating room environment.

Repair of a mycotic aneurysm of the infrarenal aorta in a patient with HIV, using a Palmaz stent and autologous femoral vein graft

With the widespread use of endovascular surgery, aneurysms can be managed selectively with the use of stent grafts. Standard treatment of mycotic aneurysms usually requires resection and extraanatomic bypass. Although stent graft repair of a mycotic femoral aneurysm with autologous graft has been reported, we present a case of an infrarenal mycotic aneurysm in a patient with the human immunodeficiency virus (HIV) that was successfully treated with a novel endovascular approach.

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.

Infected endovascular stents managed with medical therapy alone

More than 400,000 endovascular stents are put in place in the United States annually. Infectious complications have been reported in fewer than one in 10,000 cases. It remains unclear whether the optimal management strategy for these patients is with medicine alone or surgery. We report two cases of endovascular stent infections that were treated successfully with antibiotics alone.

Staphylococcal pericarditis following percutaneous transluminal coronary angioplasty

Infectious complications occurring after percutaneous transluminal coronary angioplasty are uncommon. We are reporting a case of bacterial pericarditis developing 1 week after coronary angioplasty and stent implantation. Treatment with appropriate antibiotics and drainage of the infected pericardial effusion was followed by a protracted hospital course and eventual control of infection and discharge of the patient.

Osteomyelitis of the spine and abscess formation in the left thigh after stent-graft implantation in the superficial femoral artery

PURPOSE

To present a rare case of abscess formation around a covered stent in the superficial femoral artery.

METHODS AND RESULTS

Two weeks after balloon dilation of a left superficial femoral artery (SFA) occlusion, during which a Hemobahn covered stent had been placed to treat dissection, a 77-year-old nondiabetic male developed intolerable pain and swelling of his left thigh. An abscess had formed around the stent, which was patent; intravenous antibiotic therapy quelled the symptoms, and the patient discontinued his oral antibiotic regimen weeks after discharge. General septicemia ensued. Acute lower limb ischemia and excruciating back pain prompted readmission. The SFA stent-graft occlusion required femoropopliteal bypass; the abscess and spondylodiskitis that had developed in the T12 and L1 vertebrae responded to intravenous antibiotics. The patient is without signs of infection at 6 months.

CONCLUSIONS

Local and systemic infections associated with intraluminal prostheses are rare, and prophylactic antibiotic therapy is not commonly employed. Balloon- or device-induced arterial injury may expose the arterial wall to bacterial colonization, suggesting that patients receiving lengthy stents or experiencing arterial injury during angioplasty should receive antibiotics as a precautionary measure.

Subclavian arteritis and pseudoaneurysm formation secondary to stent infection

Technically uncomplicated percutaneous angioplasty and stent placement of a left subclavian artery stenosis was performed in a 56-year-old man for treatment of subclavian steal syndrome and vertebrobasilar insufficiency. Six days later the patient was readmitted with Staphylococcus aureus bacteremia and stigmata of septic emboli isolated to the ipsilateral hand. Nine days later he had computed tomography (CT) evidence of a contrast-enhancing phlegmon surrounding the stent. Despite clinical improvement and resolution of bacteremia on intravenous antibiotic therapy, the phlegmon progressed, and at day 21 a pseudoaneurysm was angiographically confirmed. The patient underwent surgical removal of the stented arterial segment and successful autogenous arterial reconstruction. The possible contributory factors leading to stent infection were prolonged right femoral artery access and an infected left arm venous access. Although the role of prophylactic antibiotics remains to be defined, it may be important in cases where the vascular access sheath remains in place for a prolonged period of time.

Infectibility of endovascular stents following antibiotic prophylaxis or after arterial wall incorporation

BACKGROUND

Case reports of endovascular stent infection have been accumulating in the last several years. We sought to determine if prophylactic antibiotics would prevent stent/artery complex infections in a swine model if given before a bacterial challenge at the time of stent placement and 4 weeks following deployment. We also investigated whether arterial wall incorporation protected the stent against infection without antibiotic prophylaxis.

METHODS

Balloon expandable Palmaz stents were placed in the iliac arteries of 42 swine. At the same time, angioplasty was performed on the contralateral iliac artery as a control. In group A, prophylactic cefazolin was given to 12 swine at the time of stent deployment followed by an intraaortic bacterial challenge of Staphylococcus aureus. In group B, 10 swine received prophylactic cefazolin followed by intravenous S aureus 4 weeks after iliac stenting and angioplasty. In group C, 3 months following iliac stent placement and angioplasty an intravenous bacterial challenge was administered with S aureus. All swine were euthanized, and the iliac stent/artery complex and the contralateral angioplastied iliac artery were harvested and sent for culture and pathology. Experimental groups were compared with results from our previously published swine infection model using the Fisher's exact test. P values were considered significant if less than 0.05.

RESULTS

Group A: Two of the 12 (17%) stent/artery complexes in the antibiotic treatment group had positive cultures. This compares with 7 of 10 (70%) in the control group (P = 0.016). In addition, there was one infection in an angioplastied vessel contralateral to one of the two stent infections. Molecular strain typing verified that the positive cultures were the same strain that was used to challenge the animals. No vessel thrombosis occurred in the stented arteries even in the presence of infection. Group B: One of 10 (10%) stented iliac arteries had a culture positive infection. This compares with 7 of 14 (50%) positive cultures in the control group (P = 0.04). In addition, one angioplastied vessel did have mild S aureus growth on culture. Both positive cultures were verified to be the same as the injected strain by molecular strain typing. There were no thrombosed or occluded vessels. Group C: One of 15 patent stents had growth of S aureus on culture and evidence of acute inflammation on histopathologic examination. The stent infection rate of 1 of 15 (7%) patent stents in this study was significantly less than the infection rates with bacterial challenge at placement (7 of 10, 70%; P < 0.01) and at 1 month postplacement (7 of 14, 50%; P = 0.0142). Five stents occluded without evidence of infectious cause.

CONCLUSIONS

The results of this study support a recommendation that antibiotic prophylaxis should be used at the time of arterial stent placement and early after placement at times of anticipated bacteremia, but indefinite prophylaxis may be unnecessary due to arterial wall incorporation of the stent.

Septic endarteritis and fatal iliac wall rupture after endovascular stenting of the common iliac artery

A 52-year-old female with arterial occlusive disease underwent an uneventful percutaneous transluminal angioplasty and placement of a vascular metallic stent in the left common iliac artery. Ten days later she presented with clinical symptoms of septic endarteritis. Shortly after re-admittance, an emergency laparotomy had to be performed because of an acute retroperitoneal bleeding. Rupture of the common iliac artery directly overlaying the penetrating stent was found but control of haemorrhage was of no avail. In this report of a case, septic endarteritis following placement of a vascular metallic stent preceded fatal rupture of the common iliac artery. This up to now unknown constellation requires surgical intervention without undue delay.

Infection of endovascular stents: an uncommon but important complication

In this review article, four cases of peripheral endovascular stent infection (including a case presented in this issue of the journal) reported in the medical literature are reported. While the actual incidence of endovascular stent infection is probably low, when it occurs it can have serious consequences. This complication may result in the death of a patient, as seen in two of the case reports. The presentation of this complication, the site of stent deployment, the treatment given and the outcome in each of these cases are discussed. Stent infection should be recognized early to avoid the high morbidity and mortality of this complication.

Endoluminal treatment of vascular occlusive disease

The logical desire to avoid major cutaneous incisions and surgical dissection in the treatment of vascular occlusive disease has, in recent years, led to a surge of new therapeutic options whereby access to the diseased blood vessel is obtained via a distant site and treatment is effected from within the vessel. Such endoluminal treatment modalities include thrombolysis, balloon angioplasty, atherectomy, stenting, and stent grafting. For the purpose of this surgically oriented article, the latter two techniques are discussed.

Mycotic renal artery degeneration and systemic sepsis caused by infected renal artery stent

A case of Staphylococcus aureus renal artery stent infection was studied. Fourteen days after the procedure, the patient had a fever, hypotension, and an elevated white blood cell (WBC) count. Blood cultures were positive for S. aureus on admission and during the patient's hospitalization, despite intravenous vancomycin therapy. Evaluation included serial CT scans, revealing increasing persistent inflammation with development of multiple renal intraparenchymal abscesses, and arteriography, showing marked degeneration of the renal artery. Therapy required resection of the renal artery/stent and nephrectomy. This case confirms the severe nature of S. aureus stent infection; we recommend prophylactic antibiotics before these procedures, as well as expeditious evaluation and consideration for aggressive surgical therapy if this complication is suspected.

Infected renal artery pseudoaneurysm and mycotic aortic aneurysm after percutaneous transluminal renal artery angioplasty and stent placement in a patient with a solitary kidney

Endovascular infections after percutaneous transluminal renal angioplasty with stenting (PTRAS) are rarely reported. Because strict longitudinal follow-up of patients undergoing PTRAS is lacking, the true incidence of such complications remains obscure. We report the first case of a patient with an infected renal artery pseudoaneurysm and de novo mycotic aortic aneurysm after PTRAS. This case serves to illustrate several important points, including (1) the retrieval of renal function in patients with renal artery occlusion, (2) the pathogenesis of infection after PTRAS, (3) the diagnosis and management of endovascular infection after percutaneous vascular intervention, and (4) recommendations for periprocedural antibiotic prophylaxis during PTRAS.

Aortoiliac stent deployment versus surgical reconstruction: analysis of outcome and cost

PURPOSE

The purpose of this study is to compare complication rate, primary patency, and cost of stent deployment with direct surgical reconstruction for the treatment of severe aortoiliac occlusive disease.

METHODS

From March 1, 1992, to May 31, 1996, 119 patients receiving treatment for aortoiliac occlusive disease were analyzed after exclusions. Sixty-five patients had stent deployment and 54 patients had surgical reconstruction. Data were evaluated within and between the groups by univariate and multivariate logistic regression, life-table, t-test, and cross tabulation with chi2 analysis.

RESULTS

There was no significant difference between the groups with regard to demographic features or presenting symptoms (all p values > 0.07). Incidence of procedure-related complications was similar (p = 0.30). However, there were more systemic complications in the surgery group (15 versus 2; RR = 5.5, p < 0.01) and more vascular complications in the stent group (16 versus 3; RR = 12, p < 0.002). Incidence and type of late complications were not appreciably different (all p values > 0.05). Cumulative primary patency rate of bypass grafts was significantly better than stented iliac arteries at 18 months (93% versus 77%), 30 months (93% versus 68%) and 42 months (93% versus 68%); p = 0.002, log rank. Multivariate analysis identified female gender (RR = 4.6, p = 0.03), ipsilateral SFA occlusion (RR = 5.6, p = 0.01), procedure-related vascular complication (RR = 9.7, p = 0.002), and hypercholesterolemia (RR = 5.0, p = 0.02) as independent predictors of bypass graft or stent thrombosis. Mean total hospital cost per limb treated did not differ significantly between surgery and stent deployment groups ($9383 versus $8626, respectively; p = 0.66, t-test).

CONCLUSIONS

Treatment of severe aortoiliac occlusive disease by surgical reconstruction or stent deployment has a similar complication rate. Mean hospital cost per limb treated is essentially equal. However, cumulative primary patency rate of bypass grafts is superior to stents. Therefore, considering the elements of cost and patency, surgical revascularization has greater value. The benchmark for cost-effective treatment of severe aortoiliac occlusive disease is direct surgical reconstruction.

Stent-graft repair of mycotic superficial femoral artery aneurysm using a Palmaz stent and autologous saphenous vein

Developing endoluminal technology has permitted the management of selected aneurysms using stent-grafts, but the applicability and durability of these new devices has not yet been proven. Standard treatment of mycotic aneurysms generally requires arterial ligation, excision and debridement, and autologous or extraanatomic synthetic bypass. A saphenous vein-covered stent was used to exclude an expanding, mycotic, superficial femoral artery aneurysm in a critically ill patient. Although stent-graft exclusion was intended as a bridge to standard therapy, the mass resolved, the superficial femoral artery remains patent, and the patient is symptom-free at 1 year without further intervention. Additional experience is required to determine whether stent-grafts have a role in the management of mycotic aneurysms.