Endovascular stent infection

Aortoiliac stent placement in patients treated for intermittent claudication

PURPOSE

To assess the results of iliac artery stent placement for the treatment of patients with intermittent claudication.

MATERIALS AND METHODS

Lesions in 90 iliac arteries were treated in 65 patients with 111 Wallstents and 21 Palmaz stents. Stents were placed for symptoms of intermittent claudication classified as grade I, categories 1-3 by the SVS/ISCVS/SCVIR reporting standards. Sixty-two stenosed arteries and 28 chronically occluded arteries were treated. Patients were followed for up to 57.1 months (mean, 17.4 months +/- 14.9).

RESULTS

Technical success was achieved in 87 of 90 iliac limbs (97%), with major complications in seven of 65 patients (11%). The 30-day mortality was zero. Mean pressure gradients across stenoses improved from 14.7 mm Hg +/- 9.8 to 1.4 mm Hg +/- 1.4 (P < .001). Ankle-brachial indices improved from 0.62 +/- 0.21 to 0.90 +/- 0.18 (P < .001). With use of the Rutherford criteria, 84% demonstrated +2 or +3 improvement. The cumulative patency rates were 77%, 71%, 62%, and 62% at 1, 2, 3, and 4 years (standard error [SE] < 10%). Continued clinical and noninvasive test benefit was present in 80%, 80%, 73%, and 73% at 1, 2, 3, and 4 years, respectively (SE < 10%).

CONCLUSIONS

Significant hemodynamic improvement can be achieved by percutaneous stent placement, with excellent clinical results. Observed mortality in this series was zero, but major complications, requiring modification of the treatment plan, were seen in 11% of patients. Clinical results were better than suggested using current accepting reporting standards for "patency."

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.

Midaortic pseudoaneurysm complicating extensive endovascular stenting of aortic disease

We report a case of successful surgical management of a potentially life-threatening complication of aortoiliac stent placement. A 59-year-old man who had Leriche syndrome underwent bilateral iliac artery and infrarenal aortic stent placement at another institution. His history was significant for retroperitoneal lymph node dissection at 19 years of age for testicular cancer. One week after stent placement, the patient was readmitted with abdominal pain, poor oral intake, and diffuse intermittent tenderness. Evaluation with computed tomographic scanning and endoscopy was unremarkable, and the patient was discharged. He was admitted to our institution 1 week later with persistent abdominal pain. A computed tomographic scan of the abdomen revealed a large pseudoaneurysm of the abdominal aorta. The patient underwent urgent exploration, and exclusion of his infrarenal aorta was achieved with aortobifemoral bypass grafting. After the operation, the patient's course was complicated by a large paraduodenal hematoma, which resulted in a gastric outlet obstruction, which was managed without operation. This case illustrates a potential life-threatening complication of extensive stent placement for aortoiliac occlusive disease. Injury to the abdominal aorta must be considered in a symptomatic patient after the placement of stents in the aortoiliac region, beyond the immediate periprocedural period.

Infection of a chronically implanted iliac artery stent

Pseudoaneurysm formation and infection at the site of iliac artery stenting are uncommon complications that occur soon after stent placement. We describe a case in which an infected pseudoaneurysm developed 22 months following stent implantation. Stent infection, although rare, has potentially disastrous implications, as made evident by a review of the literature. Prophylactic antibiotic therapy at the time of stent placement is recommended.

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.

Conservative surgery for aortic graft infection

Surgery for aortic graft infection is a major challenge often characterized by the need for ingenuity and improvisation. Traditional treatment is by total graft excision and extra-anatomic bypass. In situ replacement of the infected graft using either autogenous tissue or antibiotic-impregnated Dacron is effective in selected cases but it is not clear when such conservative treatment may be employed. Graft excision and thorough débridement of infected tissue are important, whichever technique is used. It would seem unwise to perform in situ reconstruction unless the remaining operative field is free from contamination. When in situ replacement is selected, a rifampicin-soaked Dacron graft is the easy option, but large studies will be needed to determine whether this is a suitable long-term alternative to conventional treatment.

Complications of iliac artery stent deployment

PURPOSE

This study was performed to determine the primary patency, foot salvage, and complication rates associated with iliac artery stent deployment.

METHODS

From March 1992 to May 1995, 147 iliac artery stents were deployed in 98 limbs of 72 patients for disabling claudication or limb-threatening ischemia. Procedure-related and late (> 30 days) complications, as well as adjunctive maneuvers required to correct a complication, were tabulated. Stented iliac artery cumulative primary patency and foot salvage rates were calculated with life-table analysis. Factors that impacted early complications, late complications, foot salvage rates, and stented iliac artery primary patency rates were identified with stepwise logistic regression analysis.

RESULTS

A procedure-related complication occurred in 19 (19.4%) limbs. Initial technical success, however, was achieved in all but three of 98 limbs (96.9%). Stented iliac artery cumulative primary patency rates were 87.6%, 61.9%, 55.3%, and foot salvage rates were 97.7%, 85.1%, 76.1%, at 12, 18, and 24 months, respectively. External iliac artery stent deployment, superficial femoral artery occlusion before treatment, and single-vessel tibial runoff before treatment negatively affected stented iliac artery cumulative primary patency rates. Stented iliac artery primary patency rates were not significantly affected by age, smoking, coronary artery disease, diabetes, hypercholesterolemia, hypertension, presenting symptom, early complication, number of stents deployed, type of stent deployed, or stent deployment for stenosis versus occlusion.

CONCLUSIONS

Limb-threatening and life-threatening complications can be associated with iliac artery stent deployment. Stented iliac artery primary patency rates are affected by distal atherosclerotic occlusive disease and the position of the deployed stent within the iliac system. Stent reconstruction of severe iliac artery occlusive disease is feasible but should be thoughtfully selected.