Infected iliac pseudoaneurysm after uncomplicated percutaneous balloon angioplasty and (Palmaz) stent insertion: a case report and literature review

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.

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.

Successful endovascular treatment of a ruptured gigantic pseudoaneurysm of the common iliac artery secondarily complicated by infection

We report our experience with a case of emergent endovascular treatment of a large ruptured pseudoaneurysm of the common iliac artery. A 65-year-old male was admitted to the surgical department in hypovolemic shock, due to active retroperitoneal bleeding. A computerized tomography scan with intravenous contrast revealed a ruptured gigantic pseudoaneurysm of the right common iliac artery, with a maximal diameter of 7 cm and retroperitoneal hematoma. An intraoperative angiogram revealed active extravasation through the neck of the pseudoaneurysm, which was successfully sealed with the placement of a stent graft (Medtronic Endurant(®))limb component. Infection of the pseudoaneurysm sac after one month was successfully treated with catheter drainage. No shortterm relapse occurred. Endovascular management should be part of the basic surgical armamentarium on emergent basis, since it provides a fast and safe solution, especially when a patient's co-morbitities preclude open management and hemodynamic and anatomical status allows endovascular treatment.

Prophylactic antibiotic guidelines in modern interventional radiology practice

Modern interventional radiology practice is continuously evolving. Developments include increases in the number of central venous catheter placements and tumor treatments (uterine fibroid therapy, radio- and chemoembolization of liver tumor, percutaneous radiofrequency and cryoablation), and new procedures such as abdominal aortic aneurysm stent-graft repair, vertebroplasty, kyphoplasty, and varicose vein therapies. There have also been recent advancements in standard biliary and urinary drainage procedures, percutaneous gastrointestinal feeding tube placement, and transjugular intrahepatic portosystemic shunts. Prophylactic antibiotics have become the standard of care in many departments, with little clinical data to support its wide acceptance. The rise in antibiotic-resistant strains of organisms in all hospitals worldwide have forced every department to question the use of prophylactic antibiotics. The authors review the evidence behind use of prophylactic antibiotics in standard interventional radiology procedures, as well as in newer procedures that have only recently been incorporated into interventional radiology practice.

Quality improvement guidelines for endovascular treatment of iliac artery occlusive disease

Endovascular therapy is the treatment of choice for type A and the preferred treatment for type B lesions. In selective patients, this type of treatment can be applied in type C and even type D lesions. Ipsilateral femoral, contralateral femoral, and brachial approach and both the intraluminal and subintimal space can be used for successful recanalization. The application of stents has improved the immediate hemodynamic and probably long-term clinical results of iliac percutaneous transluminal angioplasty. However, the superiority of primary or direct stenting over selective stenting has not been proven yet. The choice of stent type depends on lesion morphology and location but otherwise there is insufficient evidence to support the use of a particular stent design. There is insufficient evidence to justify routine use of covered stents. All patients should receive antiaggregant therapy following endovascular recanalization of iliac arteries. There is no consensus regarding prophylaxis with antibiotics in iliac recanalization procedures.

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.

Late Infected Pseudoaneurysm Formation after Uneventful Iliac Artery Stent Placement

Percutaneous transluminal angioplasty and endovascular stent placement are becoming common techniques for iliac artery stenosis and obstruction that are intended to reduce the need for surgical bypass procedures. The usual complications include acute or subacute thrombosis, distal embolization, dissection, and extravasation. Although stent infection is very rare after stent replacement, it is reportedly associated with a high risk of morbidity and mortality, and the use of prophylactic antibiotics should be considered. We present a case of rupture of an infected pseudoaneurysm at the site of the external iliac artery that occurred 4 months after an uneventful percutaneous transluminal angioplasty and stent placement.

Aneurysmal Degeneration of the Superficial Femoral Artery following Stenting: An Uncommon Infectious Complication

Infrainguinal angioplasty and stenting is becoming a more commonly performed procedure. Its durability remains a matter of debate, however. Aneurysmal degeneration following angioplasty and stenting is a complication not previously described in the literature with regard to the superficial femoral artery. We present a case in which two aneurysms of the superficial femoral artery developed following angioplasty and multiple-stent placements in a patient who had previously undergone a failed femoral-to-below-the-knee popliteal artery PTFE bypass graft. The patient presented to our institution with an occluded, infected bypass graft. He was treated with graft and femoral artery/stent excision and vein bypass grafting. A brief review of infectious complications after stent placement is included.

Iliac artery rupture during balloon dilatation: what treatment?

Intraoperative and postoperative arterial ruptures associated with 657 iliac artery balloon dilatation procedures in our department from 1981 to 2000 were prospectively collected and retrospectively analyzed. Our results showed that failure to exercise basic safety principles and the presence of heavily calcified plaque are the major predictors of iliac artery rupture during balloon dilatation. If rupture is contained, surveillance alone is unreliable. Optimal treatment requires temporary hemostasis by balloon tamponade followed by placement of a covered stent to occlude the opening.

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.

Pseudoaneurysm formation at the site of external iliac artery stents: percutaneous stent-graft treatment

PURPOSE

To present a patient who developed an asymptomatic large iliac pseudoaneurysm complicating stent-supported iliac artery recanalization.

CASE REPORT

The pseudoaneurysm was detected in an asymptomatic 69-year-old man during routine angiography 6 months after an uncomplicated procedure to implant 3 overlapping Palmaz stents in an occluded external iliac artery. There was no evidence of stent infection. During a second intervention, the pseudoaneurysm was successfully treated by percutaneous implantation of an EndoPro System I stent-graft. Contrast-enhanced spiral computed tomography at 6 and 12 months confirmed the durability of aneurysm exclusion and the patency of the endoprosthesis.

CONCLUSIONS

Angioplasty-induced pseudoaneurysm is rare and usually asymptomatic, but elective percutaneous stent-graft repair should be considered as the first treatment option.

Common iliac artery pseudoaneurysm following inguinal hernia repair--a case report and literature review

The authors report a patient presented with a ruptured infected iliac artery pseudoaneurysm 2 weeks after ipsilateral inguinal hernia repair. Pseudoaneurysms that occur because of infection develop rapidly and mandate ligation of the affected artery and extraanatomic bypass. Noninfected pseudoaneurysms are usually discovered incidentally and may be managed with either endovascular or standard surgical techniques. A percutaneously placed aortic occlusion balloon may prevent exsanguination, when used as an adjunct to surgical repair in cases of ruptured pseudoaneurysm.

Infected aneurysms of neck and limb arteries: a retrospective multicenter study

Infected aneurysms (IA) of neck and limb arteries are uncommon. This report describes the results of a retrospective study undertaken by the University Association for Surgical Research (AURC) to evaluate etiology, bacteriology, location, diagnostic features, and therapeutic methods associated with IA. A total of 58 IA in 52 patients were reviewed. The lesion was located in a lower extremity artery in 47 patients (81%), internal carotid artery in 7 (12%), and upper extremity artery in 4 (6%). Eleven patients had multilocular aneurysm (21%). Symptoms of local infection were observed in 43 patients (82.6%). Rupture or splitting was the presenting manifestation in 13 patients (25%). Primary IA following bacteremia or septicemia without endocarditis was the most common type of IA observed in 34 patients (65.3%). Twelve patients (23%) presented mycotic IA secondary to bacterial endocarditis. In the remaining six patients (11.5%), IA resulted from direct contamination or spreading from a contiguous infection site. Surgical treatment included ligation of the artery without reconstruction in 19 patients and exclusion bypass in 33 patients. The duration of antibiotic treatment ranged from 15 days to 3 months. No recurrence of aneurysm was observed but three patients developed bypass infection. Primary IA was associated with high mortality due to severe septicemia.

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.

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.

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.

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.

Intraoperative endovascular angioplasty and stenting of iliac artery: an adjunct to femoro-popliteal bypass

BACKGROUND

With the rapid development of endovascular techniques, the management strategy of patients with multilevel atherosclerotic arterial occlusive disease is also evolving. Iliac artery stenting is a means whereby multiple bypass operations can be avoided in such patients. The early results of preoperative iliac artery stenting seem promising but the role of intraoperative iliac artery angioplasty and stenting is less clear.

STUDY DESIGN

This study was undertaken to evaluate our early results of a combined endovascular and operative approach to patients with multilevel atherosclerotic arterial occlusive disease. Between June 1995 and March 1997, primary intraoperative iliac artery balloon angioplasty and stent placement were performed on 13 affected limbs of 12 patients undergoing an infrainguinal bypass operation. Indications for operation, patient demographics, and risk factors were noted. The outcome of surgery and the patency rates of bypass graft and stent were also recorded.

RESULTS

The initial technical success of primary iliac artery angioplasty and stenting was 93%. An improvement of the ankle-brachial index by a mean value of 0.38 was attained after operation (p < 0.001). Clinical success, based on the criteria suggested by the Society for Vascular Surgery/International Society for Cardiovascular Surgery, was achieved in all patients. There was no operative or hospital mortality. Postoperative morbidity rate was 8% (n = 1). The cumulative 1-year patency rates of iliac stent and infra-inguinal bypass grafts were 100% and 85%, respectively. The limb loss rate was 7%.

CONCLUSIONS

The technique of intraoperative angioplasty and stenting can be easily mastered by an experienced and skilled vascular surgeon, using a portable C-arm fluoroscopic unit, in the operation theater. A combined endovascular and operative approach optimizes the therapeutic option to this selected group of patients.

Endovascular stent infection with delayed bacterial challenge

BACKGROUND

Reports of endovascular stent infection have recently been described. The purpose of this study was to determine if intravascular metallic stents in a swine model could become infected following a bacterial challenge given remote from the time of stent placement.

METHODS

Balloon expandable metallic stents (Palmaz) were implanted in the iliac arteries of 14 swine. An angioplasty, without stent placement, was also performed in the contralateral iliac artery. An intravenous bacterial challenge with Staphylococcus aureus was given 4 weeks after stent placement. Euthanasia was performed 72 hours after the bacterial challenge. At the time of euthanasia, the iliac artery/stent complex and the contralateral angioplastied iliac artery were harvested and sent for microbiologic and pathologic analysis.

RESULTS

Seven of the 14 stent/artery complexes were culture positive for S aureus whereas only one of the 14 angioplastied arteries was positive for S aureus (P = 0.03). On histologic examination, 6 of the 14 stent/artery complexes had evidence of acute inflammatory changes in the arterial wall. This compares with only 1 of 14 angioplastied arteries having evidence of inflammatory infiltrate in the arterial wall (P = 0.07). All 6 of the stent/artery complexes with inflammatory infiltrate were culture positive.

CONCLUSION

In the swine model, intravascular metallic stents have the potential to become infected when a bacterial challenge is given 4 weeks after stent placement. Further studies evaluating the incidence of stent infections in humans are needed.