Infrarenal aortic stents: initial clinical experience and angiographic follow-up

Endovascular Stent-Anchored Aortic Grafts: A Comparison between Self-Expanding and Balloon-Expandable Stents in Minipigs

Purpose:

To study endovascular graft attachment with self-expanding Gianturco Z-stents and balloon-expanded Palmaz stents and the effect of these devices on the renal ostia.

Methods:

Ten stent-grafts were constructed, 5 with Gianturco Z-stents and 5 with Palmaz stents. The endografts were implanted under fluoroscopic guidance into the abdominal aorta of 10 pigs so that the uncovered portion of the proximal stent extended over the renal artery orifices. Distal aortic blood pressure and flow were measured before and after graft placement and 1 hour postprocedure. The aorta was then exposed surgically, and the central portion of the stent-graft was inspected through an aortotomy to assess perigraft leakage.

Results:

Stent-graft implantation was accurate and hemostatic in all cases, despite longitudinal folding of the graft due to oversizing. However, transverse folds produced pressure gradients (> 15 mmHg) between the ends of the graft in two cases. In another case, a pressure gradient resulted from partial thrombosis of the graft. In two cases, renal artery occlusion and thrombosis occurred due to coverage by the graft material. In two other animals, one of the renal arteries was entirely uncovered by a stent. The remaining 16 renal arteries were covered by the proximal stent but not the graft, as intended. One (6.25%) of these arteries thrombosed, but the remainder were grossly patent when the animals were sacrificed at 1 hour.

Conclusions:

Both Palmaz and Gianturco Z-stents produced hemostatic endovascular graft attachment, even in the presence of moderate graft oversizing. The risk of acute renal artery occlusion from juxtarenal stenting does not appear to be prohibitive, but longer term observations are needed.

Endovascular treatment of infrarenal abdominal aortic lesions with or without common iliac artery involvement

PURPOSE

To evaluate the results of stent placement for obstructive atherosclerotic aortic disease with or without involvement of the common iliac artery.

MATERIALS AND METHODS

Forty patients had self-expanding stents primarily or after balloon dilatation in the abdominal aorta between January 2005 and May 2011. All patients had trouble walking. Follow-up examinations were performed with clinical visits; these included color Doppler ultrasonography and computed tomographic angiography.

RESULTS

Technical, clinical, and hemodynamic success was achieved in all patients. None of the patients underwent reintervention during the follow-up period, which ranged from 3 months to 6 years (median 24 months). Nine complications occurred in six patients. Of the nine complications, four were distal thromboembolisms, which were successfully treated with catheter-directed thrombolysis or anticoagulation therapy.

CONCLUSION

Endovascular treatment of the obstructive aortic disease using self-expanding stents was safe and effective, with high technical success and long-term patency. Thromboembolic complications were high even though direct stenting was considered protective for thromboembolism formation. Particularly for infrarenal aortic stenosis, it can be recommended as the first-line treatment option for patients with obstructive atherosclerotic aortic disease.

Endovascular management of aortoiliac occlusive disease

Patients with aortoiliac occlusive disease (AIOD) may be asymptomatic or may have intermittent claudication or critical limb ischemia. Treatment options for AIOD include management of risk factors, endovascular intervention, and/or surgical revascularization.

Low-profile primary stent placement for the treatment of focal calcified ulcerated stenosis in the infrarenal aorta

PURPOSE

To analyze the immediate and midterm success of low-profile stent placement in calcified ulcerated lesions of the infrarenal aorta in patients with arterial occlusive disease.

MATERIALS AND METHODS

In this prospective case series, 13 symptomatic patients (eight men, five women; mean age, 64.8 years +/- 12.1; age range, 44-84 years) with focal calcified ulcerated stenoses of the infrarenal aorta were treated with stent placement by using a low-profile technique in a radiology intervention center during a 4-year period. Clinical examinations and duplex ultrasonography were used to evaluate the stents? patency and clinical success. Kaplan-Meier graphs were calculated to analyze the freedom-of-symptom rate.

RESULTS

The initial technical success rate was 92% (12 of 13 patients). Due to extended calcifications, a residual stenosis of 50%-60% remained in one patient. No peri-interventional complications occurred. The mean follow-up was 26 months (range, 5-53 months). During follow-up, one patient had a restenosis after 7 months and presented clinically with Fontaine stage IIb. Two patients had iliac and/or femoral stenoses, and both presented with Fontaine stage IIb. One patient's symptoms originated from the lumbar spine. Primary patency and primary clinical success rates were 85% and 69%, respectively. According to Kaplan-Meier tables, the freedom-from-symptom rates were 92%, 84%, 73%, and 63% at 0, 7, 12, and 21 months, respectively.

CONCLUSIONS

Low-profile stent placement in calcified, ulcerated lesions of the infrarenal aorta is an effective and safe treatment for symptomatic stenoses in patients with arterial occlusive disease after a mean follow-up of 26 months.

Standards for the Endovascular Management of Aortic Occlusive Disease

Occlusive disease of the infrarenal aorta and aorto-iliac arteries can be safely treated by minimally invasive therapy and is now widely available. The aim of this article is to produce standards for the management of these patients using current endovascular techniques.

Primary stenting in the treatment of focal atherosclerotic abdominal aortic stenoses

AIM

To evaluate the results of primary stent placement in focal atherosclerotic aortic stenoses using balloon expandable stents.

MATERIALS AND METHODS

Twenty-six primary balloon expandable stent placements in the abdominal aorta were performed and reviewed. All the aortic stenoses were atherosclerotic. Patients were followed up by ankle/brachial pressure indices (ABPI) and Doppler ultrasound (US) at 24h after procedure and at 12 and 24 months. Follow-up angiograms were performed at 12 months.

RESULTS

Twenty-six stents in 26 patients were placed in the infrarenal aorta. All procedures were technically successful and immediate clinical success was obtained. The mean ABPI significantly improved from 0.52+/-0.10 to 0.94+/-0.09 within 24h after procedure, and remained at 0.90+/-0.12 between 12 and 24 months follow-up (mean 18 months). There was full haemodynamic success at hospital discharge and at 12 and 24 months after the procedure. Clinical success at 12 and 24 months (mean 18 months) was defined as an improvement in the Fontaine classification by at least one class compared with the pre-procedure class and was shown to be 100%.

CONCLUSION

In summary, we report that primary stenting is a safe and effective alternative to surgery in cases of symptomatic stenosis of the infrarenal abdominal aorta. The excellent intermediate term results suggested that we would recommend primary stenting as the treatment of choice for focal atherosclerotic stenoses of the infrarenal aorta in selected patients.

Long-term results of primary stent placement to treat infrarenal aortic stenosis

OBJECTIVE

To determine the safety and the long-term results of primary stent placement for localized distal aortic occlusive disease.

DESIGN

Retrospective observational study.

PATIENTS AND METHODS

From July 1998 to July 2005 17 patients (14 female and 3 men, mean age 57 years (39-80)) were treated for intermittent claudication. Five of these patients underwent additional endovascular treatment of focal iliac lesions.

RESULTS

Technical success defined as residual stenosis of less than 50% or a trans-stenotic systolic pressure gradient <10% was achieved in 14 of 17 (82%) patients. Major complications included dissection at the puncture site in one patient and thrombosis of additional iliac stents in another patient. Both of these complications were successfully treated. During a mean follow-up of 27 months (range 1-86), four patients had recurrence of symptoms due to in-stent restenoses (n=2), femoral (n=1) or iliac occlusion (n=1), respectively. By Kaplan-Meier analysis, primary aortic hemodynamic patency was 83% at 3 years. Secondary aortic hemodynamic patency was 100%. The primary clinical patency was 68% at 3 years.

CONCLUSION

Primary stent placement for distal aortic stenoses is an alternative to surgical treatment because of its high patency and relatively low complication rates.

Primary Endovascular Stent Placement for Focal Infrarenal Aortic Stenosis: Long-term Results

PURPOSE

The objectives of this retrospective study were to determine the technical success, safety, and long-term results of primary stent implantation in infrarenal aortic stenosis.

MATERIALS AND METHODS

A total of eight atherosclerotic stenoses and one occlusion of the infrarenal aorta (ie, midaortic syndrome) were treated with endoluminal stent placement after balloon angioplasty. Aortoiliac lesions were excluded. Technical success and patency were assessed.

RESULTS

Primary technical success in percutaneous transluminal angioplasty and subsequent stent placement was achieved in all patients. No complications occurred, and no morbidity was encountered. Primary clinical patency rates were 100% on all follow-up examinations. Long-term results with a mean follow-up of 110 months (range, 99-117 months) were recorded in seven patients; one patient had died and one was lost to follow-up.

CONCLUSIONS

In view of the excellent initial results and promising long-term follow-up data in a small series, stent placement after predilation in properly selected patients with isolated infrarenal aortic stenosis appears to be a promising, durable treatment. It should be considered as a primary method of treatment.

Long-term Results After Primary Stenting of Distal Aortic Stenosis

PURPOSE

To review the long-term results of primary stent placement in the distal aorta above the bifurcation.

METHODS

Fourteen patients (8 men; mean age 62 years, range 46-82) underwent primary stent implantation performed by an interdisciplinary radiosurgical team. In 10 patients, a long-term follow-up examination consisting of patient history, clinical examination, and duplex sonography was performed. The ankle-brachial index (ABI) for the posterior tibial artery was calculated on the basis of Doppler pressure measurements.

RESULTS

The clinical success rate at the first follow-up examination (mean 2.9 months, range 2.1-4.4) was 100% (n = 14). The mean baseline ABI of 0.64 +/- 0.12 had risen to 1.02 +/- 0.10 (p < 0.0001). At midterm follow-up (mean 22.8 months, range 14-42) in 12 patients, the ABI was 0.96 +/- 0.12 (p < 0.0001 versus baseline). At a mean 86 months (range 51-119) after stent treatment, the ABI in 10 patients was 0.90 +/- 0.20 (p < 0.0001 versus baseline). Over the long term, the clinical success rate was 70%. Deterioration was due to the progression of atherosclerosis distal to the aorta; duplex sonography showed no aortic restenosis or occlusion.

CONCLUSION

In view of the excellent long-term results in our small series, primary stent placement in focal abdominal aortic stenosis in properly selected patients is a durable treatment. In addition, the mortality and morbidity risks are markedly reduced compared with open surgery.

Conformation of Adjacent Self-expanding Stents: A Cross-Sectional In Vitro Study

We examined the proximal conformation of three commonly used self-expanding stents when the stents were deployed adjacent to one another in a tubular model, simulating a "kissing" stent technique. The stent pairs were evaluated by computed tomogrphy to determine the cross-sectional area excluded by the stents within the model. The mean areas associated with each stent pair were compared and significance evaluated by a t-test. A statistically significant difference was found when the area excluded by adjacent Wallstents was compared with both the Luminexx and SMART stents (p < 0.001 and p < 0.002, respectively). The difference in the area excluded and differences in conformation might play a role in the lower patencies that have been observed in "kissing" stent series.

Primary Stent Placement for Infrarenal Aortic Stenosis: Immediate and Midterm Results

PURPOSE

To evaluate the safety and the long-term clinical and hemodynamic results of primary stent placement of atherosclerotic calcified stenosis of the infrarenal aorta.

MATERIAL AND METHODS

Between July 1996 and July 1999, 15 patients (nine male, si- female; mean age, 53.9 years) with symptomatic, calcified aortic stenosis were treated with primary stent placement. Patients underwent abdominal aortography and bilateral lower extremity arteriography. Follow-up was performed in all 15 patients. Technical success was defined as residual stenosis of less than 30% or a resting trans-systolic pressure gradient of less than 10 mm Hg after stent placement. Clinical patency was defined as the absence or improvement of symptoms after stent placement. Hemodynamic patency was defined as a normal triphasic Doppler waveform in the common femoral artery, an ankle-brachial index greater than 0.90, or the absence of a thigh-brachial pressure gradient at rest in either limb.

RESULTS

Technical success was achieved in 13 of 15 patients. The two patients considered to be technical failures had resting trans-systolic pressure gradients of 12 and 13 mm Hg, respectively, after stent placement. After the mean follow-up of 36 months, primary clinical and hemodynamic patency rates were 85% and the secondary hemodynamic patency rate was 100%. Two of five symptomatic recurrences during the 36-month follow-up period (range, 12-46 months) were a result of aortic restenosis and were treated with repeated percutaneous transluminal angioplasty. None of the patients required aortic surgery. Complications of the primary procedure included one puncture site infection, one pseudoaneurysm, and one distal embolization, which delayed discharge of three patients. There was no morbidity during the secondary interventions.

CONCLUSION

Primary stent placement as treatment of calcified infrarenal aortic stenosis proved to be safe and also provided durable long-term clinical improvement.

Primary Stenting of Focal Atherosclerotic Infrarenal Aortic Stenoses: Long-Term Results in 13 Patients and a Literature Review

We conducted this study to investigate the value of primary stent implantation for the endovascular treatment of focal atherosclerotic stenoses of the infrarenal abdominal aorta. The data of 13 patients with a localized complex infrarenal aortic stenosis who underwent primary stenting was retrospectively evaluated. The patients (6 females, 7 males) had a mean age of 57.3 +/- 9.1 years (mean +/- SD). In all patients, the aortic diameter was measured on CT sections, and a self-expanding endoprosthesis was primarily implanted followed by dilatation with single or double balloons. In 3 patients, additional distal stenoses were also endovascularly treated. The procedure was technically successful in all patients. No complications occurred except for 2 minor groin hematomas. During the 43 +/- 23 months (mean +/- SD) follow-up (range: 12-96 months), all stented aortic segments remained patent. Clinical patency was lost in 4 patients, which was due to atherosclerosis or restenosis distal to the aorta. In view of the excellent early and long-term results, we believe that primary stenting should be considered the first line treatment in properly selected patients with focal atherosclerotic infrarenal stenoses of the abdominal aorta.

Clinical efficacy of metal stents for the treatment of focal abdominal aortic stenosis

Seven patients (four women and three men) who underwent primary stenting of infrarenal abdominal aortic stenosis over a 4-year period are reported. The patients ranged between 44 and 77 years of age. All were referred for treatment of disabling claudication. Self-expanding stents with balloon assistance were used. A single complication, a retroperitoneal haematoma, requiring surgical intervention occurred in one patient. Patients had either complete resolution of symptoms (five of seven) or a substantial decrease in their claudication symptoms. Primary stenting is a safe and effective treatment for severe abdominal aortic stenosis.

Endovascular Treatment of Isolated Atherosclerotic Stenosis of the Infrarenal Abdominal Aorta: Long-term Outcome

The purpose of this multicenter study was to assess the long-term outcome of endovascular treatment of isolated atherosclerotic stenosis of the infrarenal abdominal aorta on the basis of clinical and ultrasound examination. Clinical, ultrasound, and angiographic findings from 36 women and 50 men (mean age, 53.2 years) treated for atherosclerotic stenosis of the infrarenal abdominal aorta were reviewed. Patients had claudication in 74 cases and rest pain in 4. Seven patients presented trophic manifestations and one had blue toe syndrome. Mean preoperative systolic index was 0.71. Mean diameter reduction was 77%. Circumferential calcification was partial in 36 cases (41%) and complete in 30 cases (35%). Percutaneous transluminal angioplasty was performed using the single-balloon technique in 60 cases and double-balloon technique in 26 cases. A stent was placed in 76 cases (88%) by necessity in 34% of cases (22 residual stenoses, 4 dissections). Completion angiographic findings were considered good in 82 cases (95%). The remaining four patients had residual stenosis with a diameter reduction >30%. One patient died during the immediate postoperative period from septicemia unrelated to treatment (early mortality, 1.2%). Aortic angioplasty was complicated by stent detachment from the angioplasty balloon in two patients, retroperitoneal hematoma in one, peripheral embolism in two, puncture-site hematoma in three, myocardial infarction in one, and thrombophlebitis of deep femoral artery in one patient (early morbidity, 9.3%). All patients underwent follow-up with clinical and hemodynamic evaluation (mean follow-up, 31 months). Actuarial survival at 3 years was 91%. Primary actuarial patency was 94% at 1 year, 89% at 3 years, and 77% at 5 years. Aortic restenosis occurred in seven patients and was treated by angioplasty in two, aortobifemoral bypass in four, and surveillance in one. Mean systolic index was 0.89. Statistical analysis of patency demonstrated no factor predictive of long-term complication. From the long-term follow-up findings in this study, we conclude that aortic angioplasty is a reliable minimally invasive technique for treatment of isolated atherosclerotic stenosis of the infrarenal abdominal aorta.

Percutaneous endovascular treatment for stenoses and occlusions of infrarenal aorta and aortoiliac bifurcation: midterm results

OBJECTIVE

evaluation and comparison of the endovascular treatment of isolated aortic and aortoiliac atherosclerotic lesions (stenoses and occlusions).

METHODS

a percutaneous endovascular procedure was performed in 52 patients (38 men and 14 women) with a mean age of 52 years (range, 25-85 years). The baseline angiogram showed 35 aortic lesions (31 stenoses, 4 occlusions) and 17 aortoiliac lesions (14 stenoses, 3 occlusions). Percutaneous techniques used in this series included variable combinations of transluminal angioplasty and stenting. All stents placements were performed over-the-wire using the transfemoral route (most often bilateral approach). Clinical examination and Duplex-scan were performed at discharge, 1 month, 6 months, 12 months, and then yearly.

RESULTS

technical success was 100% for aortic and aortoiliac lesions. Angiographic success rates were comparable for aortic (91%) and aortoiliac (94%) lesions. No death occurred during or early after the endovascular intervention. Duplex-scan confirmed 100% patency rate at discharge. There was no significant difference between the aortic (94%) and aortoiliac (96%) groups regarding immediate clinical improvement. Mean follow-up was 34+/-31 months (range, 0-130 months). The cumulative primary patency rate at 36 months was 85% in the aortic group and 86% in the aortoiliac group. Clinical success, defined as a symptom-free status at the end of follow-up, was also similar in both groups.

CONCLUSION

endovascular treatment of isolated aortic lesions of the infra-renal aorta has favorable outcomes comparable to those of aortoiliac lesions.

Percutaneous arterial aortoiliac intervention

Historically reconstructive vascular surgery, has been a cornerstone of treatment for symptomatic obliterative aortoiliac disease. Surgical results include a reported aortobifemoral bypass 5-year patency rate from 85% to 90% and a 10-year patency rate of 70% to 75%. Operative mortality for aortoiliac reconstruction ranges from 1.6% to 3.3%, with an aggregated systemic morbidity of 8.3%. Clinical indications for surgical intervention are well-established and are limited primarily to severe claudication and limb-threatening ischemia. Broader application of surgical intervention is not recommended because of significant morbidity and mortality associated with the procedure. As balloon angioplasty and endovascular stenting technologies evolve, they are proving to be an effective modality for the treatment of aortoiliac disease. These lower risk procedures have allowed expansion of traditional indications for intervention. Treatment is recommended presently for patients with clinical symptoms that impact lifestyle and professional requirements. Less conventional indications include allowing access for coronary intervention or for placement of an intra-aortic balloon pump, or improving inflow prior to a distal surgical bypass procedure. Results of aortoiliac percutaneous interventions are difficult to compare with surgical data since methods and technology continue to improve and evolve, and randomized studies are limited. It is clear that as long as outcomes of percutaneous interventions are predictable and secondary patency rates acceptable, the low complication rates of a percutaneous intervention are clearly preferable to a riskier surgical alternative.

Stenting for localised arterial stenoses in the aorto-iliac segment

OBJECTIVE

to determine complications and patency following angioplasty (PTA) and stenting of aorto-iliac stenoses.

SETTING

District General Hospital in U.K.

DESIGN

prospective observational study.

PATIENTS AND METHODS

between December 1994 and June 2000, 50 patients (38 men), median age 64 (41-89) years underwent aorto-iliac stenting. A total of 61 stents were placed. Indications were intermittent claudication in 38 and rest pain, ulceration or gangrene in 12. Sites stented were aorta 11, common iliac artery 32, external iliac artery 14, common and external iliac arteries two. Bilateral iliac procedures were carried out in nine. Two stents were used to correct residual stenoses after aortic stenting. Some 11 recurrent stenoses were treated. The other reasons for stenting were residual stenoses greater than 30% after PTA, tight calcified stenoses or when a stenosed iliac artery was being used as a donor prior to crossover or femoropopliteal bypass.

RESULTS

two immediate technical failures occurred due to malposition. Residual stenoses were corrected by PTA. Two further patients sustained minor complications. None of the aortic stents occluded through two required secondary procedures. Primary-assisted patency was thus 100% at three years. Primary patency following iliac stenting for claudication and critical ischaemia were 97% and 86% at three years respectively.

CONCLUSION

PTA and stenting of aorto-iliac stenoses can be safely achieved with durable results.

Infrarenal Aortic Stenosis: Value of Stent Placement after Percutaneous Transluminal Angioplasty Failure

PURPOSE

To evaluate the long-term clinical and hemodynamic effectiveness of aortic stent placement in cases of failure of intended infrarenal percutaneous transluminal aortic angioplasty (PTAA).

MATERIALS AND METHODS

Fifty-three patients who underwent technically successful PTAA were compared with 24 patients who underwent aortic stent placement because of PTAA failure (19 patients) or ulcerated lesions (five patients) that otherwise would have been treated surgically because of the embolization hazard associated with PTAA alone. Clinical patency was defined as the absence or improvement of symptoms after the intervention. Hemodynamic patency was defined as a normal Doppler waveform in the common femoral arteries, an ankle-brachial index greater than 0.95, or the absence of a thigh-brachial pressure gradient.

RESULTS

Three-year clinical and hemodynamic patency rates, respectively, were 85% and 79% for PTAA and 69% and 43% for aortic stent placement. No morbidity was encountered. With use of the Cox proportional hazards model, two significant risk factors were retained for restenosis: unchanged smoking habit (P =.04) and small dilatation diameter (P =.001). Aortic stent placement, performed in patients with a smaller aortic diameter (10.3 vs. 12.7 mm for PTAA), appeared to be a predictive factor for restenosis by using univariate analysis. By using the Cox proportional hazards model, however, the restenosis rates after PTAA and aortic stent placement were not significantly different.

CONCLUSION

When aortic diameter is taken into consideration, there is no evidence that clinical outcome after secondary aortic stent placement would be poorer than technically successful PTAA.

Endovascular treatment of occlusive lesions in the distal aorta: mid-term results in a series of 31 consecutive patients

The purpose of this study was to evaluate the early and mid-term results of endovascular treatment of occlusive lesions in the distal aorta in a consecutive series of patients. Between February 1996 and March 1999, a total of 31 patients underwent transluminal procedures for treatment of occlusive atherosclerotic lesions located at the lower end of the aorta. Thirty patients presented with intermittent claudication and one had critical ischemia. Manifestations were bilateral in 26 cases and unilateral in 5. The lesion was confined to the lower aorta in 3 patients and extended to the common iliac arteries in 19, with predominant proximal lesions of the common iliac artery occurring in 9 patients. Fourteen patients had concurrent infracrural occlusive lesions. All patients underwent exclusive endovascular treatment without any associated open surgical procedure. The three patients with isolated aortic lesions were treated by angioplasty, followed by stent placement in two cases. The 19 patients with aortobiiliac lesions were treated by bilateral common iliac artery angioplasty according to the "kissing-balloon" technique; 7 of these patients also underwent aortic angioplasty. In these 19 patients, aortic stenting was performed in 3 cases and bilateral iliac stenting in 10 cases, including 3 in association with aortic stenting. The nine patients with a proximal lesion of the common iliac arteries were treated by angioplasty, followed by bilateral stenting in three cases and unilateral stenting in three cases. The findings of this study show that the mid-term anatomical and functional results of endovascular treatment for atherosclerotic lesions of the distal aorta are satisfactory. We recommend it as the initial treatment modality.

Non-surgical treatment of patients with peripheral vascular disease

Dotter first described percutaneous revascularization of peripheral vascular disease (PVD) in 1964. In 1974, Gruentzig developed a balloon catheter for dilation of vascular lesions. Currently, percutaneous transluminal angioplasty (PTA) employs a variety of devices ranging from implantable stents to endovascular radiation devices for re-stenosis and is recognized as a safe and effective alternative to surgery for selected patients. In addition to the general efficacy of peripheral angioplasty, which is comparable to that of bypass surgery for selected lesions, angioplasty offers several distinct advantages over surgery. It is performed under local anaesthesia, making it feasible to treat patients who are at high risk for general anaesthesia. When compared to surgical revascularization, the morbidity from angioplasty is low, generally related to problems at the vascular access site, and mortality is extremely rare. Unlike vascular surgery, there is no recovery period after angioplasty, and most patients can return to normal activity within 24-48 h of an uncomplicated procedure. Finally, angioplasty can be repeated if necessary usually without increased difficulty or increased patient risk compared to the first procedure, and does not preclude surgery as adjunctive or definitive therapy.

Primary stenting for chronic total occlusion of the infrarenal aorta

PURPOSE

To present a rare case of chronic total occlusion of the infrarenal aorta treated with a self-expanding endoluminal stent implanted without preliminary dilation.

METHODS AND RESULTS

A 68-year-old woman presented with severe bilateral buttock and thigh claudication. Angiography revealed total occlusion of the infrarenal abdominal aorta and relatively normal iliac vessels. Via a right groin puncture and a 9-F sheath, a 14-mm x 5-cm self-expanding Wallstent was deployed in the abdominal aorta and expanded with an angioplasty balloon. Completion angiography showed successful recanalization of the aorta with satisfactory distal flow. Palpable distal pulses were restored, and the patient's symptoms were alleviated. She remained asymptomatic until her death from a major stroke 11 months after aortic stent implantation.

CONCLUSIONS

Primary stenting may be considered a viable alternative to conventional surgery in selected patients with total infrarenal aortic occlusion.

Primary stenting in infrarenal aortic occlusive disease

PURPOSE

To evaluate the results of primary stenting in aortic occlusive disease.

METHODS

Thirty patients underwent primary stenting of focal concentric (n = 2) and complex aortic stenoses (n = 19), and aortic or aorto-iliac occlusions (n = 9). Sixteen patients underwent endovascular outflow procedures, three of whom also had distal open surgical reconstructions. Median follow-up was 16 months (range 1-60 months).

RESULTS

Guidewire crossing of two aorto-biiliac occlusions failed, resulting in a 93% (28/30) technical success. Major complications included one access hematoma, one myocardial infarction, one death (recurrent thromboembolism) in a patient with widespread malignancy, and one fatal hemorrhage during thrombolysis of distal emboli from a recanalized occluded iliac artery. One patient did not improve his symptoms, resulting in a 1-month clinical success of 83% (25/30). Following restenting the 26 stented survivors changed their clinical limb status to +3 (n = 17) and +2 (n = 9). During follow-up one symptomatic aortic restenosis occurred and was successfully restented.

CONCLUSIONS

Primary stenting of complex aortic stenoses and short occlusions is an attractive alternative to conventional surgery. Larger studies with longer follow-up and stratification of lesion morphology are warranted to define its role relative to balloon angioplasty. Stenting of aorto-biiliac occlusions is feasible but its role relative to bypass grafting remains to be defined.

Early and long-term results of percutaneous transluminal angioplasty of the lower abdominal aorta

PURPOSE

The purpose of this study was to determine the early and long-term results of percutaneous transluminal angioplasty (PTA) of atherosclerotic lower abdominal aorta stenosis.

METHODS

This study was performed as a retrospective study. From 1980 to 1997, 46 patients with chronic lower limb ischemia with moderate to severe claudication as the result of isolated infrarenal disease or aortoiliac disease underwent PTA. All patients underwent angiography before and after angioplasty and Doppler ultrasound scan examination with ankle-brachial index determination. No stents were used.

RESULTS

The technical success rate was 96% (44 of 46 cases). Thirty-eight patients (83%) immediately showed clinical, hemodynamic, and angiographic improvement. The initial success rate for patients with isolated infrarenal or bifurcation disease was 92%, whereas it was 71% for aortoiliac disease. Among the eight patients with no initial improvement, four had clinical deterioration and two required emergency surgical revascularization. There were no other complications. Fifty-six percent of the patient conditions (95% confidence interval [CI], 38% to 74%) remained clinically improved at the 5-year follow-up examination. Recurrence of symptoms was caused by femoropopliteal disease in most patients. The primary patency rate assumed with maintenance of hemodynamic improvements was 70% (95% CI, 52% to 88%) and 64% (95% CI, 44% to 84%) at 4 and 5 years of follow-up, respectively. The primary patency rate at 4 years for patients with isolated infrarenal or bifurcation disease was 83% (95% CI, 64% to 100%), whereas it was 55% for aortoiliac disease (95% CI, 30% to 80%; P =.06) The variables that were statistically predictive of patency failure were poor runoff (P =. 01) and presence of aortoiliac atherosclerotic disease (P =.04).

CONCLUSION

Our results suggest that PTA is an excellent treatment for chronic arterial insufficiency of the lower extremities as the result of isolated atherosclerotic lower abdominal aortic occlusive lesions because of good long-term patency. Aortic PTA for those patients with iliac involvement or with poor runoff gives acceptable results but carries lower patency and clinical success rates.

Late in-stent restenosis of the abdominal aorta in a patient with Takayasu's arteritis and related pathology

This report describes an in-stent restenosis of the infrarenal aorta in a patient with Takayasu's arteritis in a nonactive state. A 10-mm-diameter Wallstent had been deployed 42 months previously. The stented restenosed segment was replaced by a surgical graft. Histopathological examination of the excised aortic segment showed a thin layer of fibrocellular neointima and massive organized and calcified thrombus. To our knowledge, this is the first histopathological report of a late in-stent restenosis of the abdominal aorta in Takayasu's arteritis.

Comparison of conventional angioplasty with the Palmaz stent in the treatment of abdominal aortic stenoses from the STAR registry. SCVIR Transluminal Angioplasty and Revascularization

PURPOSE

To retrospectively compare the safety and short-term efficacy of conventional percutaneous transluminal angioplasty (PTA) and PTA with the Palmaz balloon-expandable intravascular stent for the treatment of infrarenal abdominal aortic atherosclerotic stenoses.

PATIENTS AND METHODS

The records of 25 patients with infrarenal aortic stenoses treated by means of percutaneous techniques were retrieved from the SCVIR Transluminal Angioplasty and Revascularization (STAR) Registry and analyzed. Thirteen patients were treated with PTA alone and 12 were treated with the Palmaz intravascular stent.

RESULTS

Technical success was achieved in 92% of patients treated with PTA alone and in 100% of those treated with the Palmaz stent. Significant improvements in lesion morphology, hemodynamics, clinical status, and ankle arm indexes were shown in both groups. There was no statistically significant difference in percent stenosis reduction, decrease in trans-stenotic gradient, or initial clinical outcome between the group treated by means of PTA and the group treated by means of PTA with the Palmaz stent.

CONCLUSIONS

PTA and intravascular stent placement of atherosclerotic stenoses involving the infrarenal aorta are both safe and efficacious therapeutic modalities. At present, it does not appear that primary stent placement confers any short-term benefits over technically successful PTA in aortic stenoses.

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.

Renal arteries covered by aortic stents: clinical experience from endovascular grafting of aortic aneurysms

OBJECTIVES

During the endovascular repair of abdominal aortic aneurysms (AAAs), effective anchoring of the stent-graft is difficult in the presence of a short infrarenal aneurysm neck. The aim of this study was to investigate renal artery patency and renal function after deployment of graft anchoring stents across the renal arteries.

DESIGN

Retrospective open study.

PATIENTS

Twenty-five renal arteries, in 18 patients treated by endovascular exclusion of an AAA, were intentionally covered with the Gianturco Z-stent to ensure stent graft attachment.

METHODS

Renal artery patency was assessed by repeated spiral computed tomography (CT) scans and angiography. Creatinine levels, blood pressure and antihypertensive medication were recorded. Follow-up was a median 6 months (2-9).

RESULTS

All 25 stent-covered renal arteries remained patent. CT showed a small infarct in one kidney. Creatinine was 108 mumol/l (89-133) before intervention and 98 mumol/l (87-127) at follow-up. Blood pressure was 150/80 mmHg on both occasions. Antihypertensive therapy was intensified in one patient whose creatinine level remained stable and whose separate renin sampling was normal.

CONCLUSIONS

Covering the renal arteries with the Gianturco Z-stent does not seem to affect renal function within 6 months. Further follow-up is needed before suprarenal stent deployment can be advocated.

The effect of endovascular aortic stents placed across the renal arteries

OBJECTIVES

To investigate renal artery patency and renal function after deployment of aortic stents covering the orifices of renal arteries.

DESIGN

Prospective open animal study.

SETTING

Department of Experimental Surgery at a university hospital.

MATERIALS

Twenty-three pigs were used.

METHODS

Ten pigs were observed for 1 h after graft-anchoring aortic stents, Gianturco (5) and Palmaz (5), were placed so that the stents covered the renal arterial orifices. In 13 pigs, Gianturco (6) and Palmaz (7) stents without grafts were placed over the renal arteries and left in situ for 7 days. Renal function and blood flow were measured by renograms, iohexol clearance and ultrasonic blood flow meter and patency was verified by angiograms. The kidneys were microscopically examined for signs of ischaemia and microemboli.

RESULTS

One renal artery covered by a graft-anchoring Gianturco stent occluded. The remaining renal arteries remained patent without any significant decrease in renal blood flow after stent deployment. Normal renal function and histology was maintained.

CONCLUSIONS

Aortic stents placed at the level of the renal arteries do not affect renal blood flow within 1 week in this experimental model. This may prove valuable in endovascular treatment of aortic aneurysms and in other procedures involving stents.

Percutaneous transluminal stent placement in the abdominal aorta

PURPOSE

To retrospectively review and to report the results of stent placement for focal mid-abdominal aortic stenoses.

MATERIALS AND METHODS

During a 4-year period, 10 focal mid-abdominal aortic stenoses were treated with stent placement in nine patients (six women and three men; mean age, 61 years; range, 49-73 years). All of the stenoses were atherosclerotic in nature except for one at the proximal anastomosis of an aortobi-femoral graft, which may have been from fibrointimal hyperplasia. Seven of the 10 stenoses were treated with primary stent placement, whereas three were treated with stent placement after suboptimal angioplasty.

RESULTS

The technical success rate was 100%. Clinical success, defined as complete elimination or improvement of symptoms present before stent placement, was achieved in eight of the nine patients with a mean duration of follow-up of 1.6 years (range, 0.2-3.0 years).

CONCLUSION

In view of the excellent technical and clinical success, the authors believe that stent placement should be considered as an adjective therapy to angioplasty or as a primary method of treatment in properly selected patients with focal mid-abdominal aortic stenoses.

Young women with advanced aortoiliac occlusive disease: new insights

We identified a group of 24 young (less than 50 years of age) women with isolated, premature atherosclerotic aortoiliac occlusive disease and attempted to identify distinguishing hemostatic characteristics. Most of these patients (62%) presented with acute thromboembolic events (blue toe syndrome, n = 6; macroemboli, n = 6; or aortoiliac thrombosis, n = 3). Aortoiliac reconstruction (aortoiliac endarterectomy, n = 10, aortobifurcation bypass grafts, n = 6; and percutaneous angioplasty, n = 4) was complicated by early thrombosis in 6 of 20 cases (30%), (1 of 10 endarterectomies, 4 of 6 bypass grafts, and 1 of 4 angioplasties). Fresh thrombus overlying an atherosclerotic plaque was a common finding at surgery. This observation and the relatively high incidence of thromboembolic events led us to hypothesize that a characteristic hemostatic profile might underlie the remarkably similar clinical presentations of these women. Levels of antiphospholipid antibodies (anticardiolipin antibodies and lupus anticoagulant), plasminogen activator inhibitor-1, fibrinogen, antithrombin III, protein C, protein S, plasminogen, prothrombin fragment F1 + 2, and D-dimer were determined for these young women and for 21 age-matched white female control subjects without vascular disease and nine white male patients with aortoiliac occlusive disease (mean 61 years, range 43 to 74 years). The incidence of anticardiolipin antibodies was 42% (8 of 19) in the female patients, which was significantly elevated (p = 0.028). The female (62.5%) and male (100%) patients had significantly elevated D-dimer levels (p < 0.001). Deficiencies of antithrombin III, protein C, and protein S were rare. A unique pattern of premature aortoiliac atherosclerosis exists in some young women. Intra-arterial thromboembolic events are common at presentation and complicate surgical management. The role of antiphospholipid antibodies remains uncertain.

Noncoronary vascular stenting

The aim of this report is to review the current state of the art with respect to noncoronary vascular stenting. A review of the literature was performed, examining the historical aspects of stent design and usage, as well as the currently available designs and their respective functions. When appropriate, we note our personal experience with stent placement in each anatomic site. Currently available stents take many forms: balloon-expandable, self-expanding, and shape-memory alloy. Varied design modifications have been made to maximize the open area, to limit the surface area of the prosthesis, to increase (or decrease) flexibility, and to increase (or decrease) stent plasticity and elasticity. Modifications to minimize thrombogenicity are also underway. The clinical uses of the currently available stents in multiple anatomic locations will be discussed. Intravascular stents are an addition to the arsenal available for prolonging blood vessel patency.

Endovascular stent-anchored aortic grafts: a comparison between self-expanding and balloon-expandable stents in minipigs

PURPOSE

To study endovascular graft attachment with self-expanding Gianturco Z-stents and balloon-expanded Palmaz stents and the effect of these devices on the renal ostia.

METHODS

Ten stent-grafts were constructed, 5 with Gianturco Z-stents and 5 with Palmaz stents. The endografts were implanted under fluoroscopic guidance into the abdominal aorta of 10 pigs so that the uncovered portion of the proximal stent extended over the renal artery orifices. Distal aortic blood pressure and flow were measured before and after graft placement and 1 hour postprocedure. The aorta was then exposed surgically, and the central portion of the stent-graft was inspected through an aortotomy to assess perigraft leakage.

RESULTS

Stent-graft implantation was accurate and hemostatic in all cases, despite longitudinal folding of the graft due to oversizing. However, transverse folds produced pressure gradients (> 15 mmHg) between the ends of the graft in two cases. In another case, a pressure gradient resulted from partial thrombosis of the graft. In two cases, renal artery occlusion and thrombosis occurred due to coverage by the graft material. In two other animals, one of the renal arteries was entirely uncovered by a stent. The remaining 16 renal arteries were covered by the proximal stent but not the graft, as intended. One (6.25%) of these arteries thrombosed, but the remainder were grossly patent when the animals were sacrificed at 1 hour.

CONCLUSIONS

Both Palmaz and Gianturco Z-stents produced hemostatic endovascular graft attachment, even in the presence of moderate graft oversizing. The risk of acute renal artery occlusion from juxtarenal stenting does not appear to be prohibitive, but longer term observations are needed.

Percutaneous transluminal angioplasty of the infrarenal aorta: initial outcome and long-term clinical and angiographic results

OBJECTIVE

Report of 1-8 year follow-up of patients treated by percutaneous transluminal angioplasty (PTA) for obstructive atherosclerosis of the infrarenal aorta.

DESIGN

Cohort study.

MATERIALS

Thirty-eight patients aged 26-81 years (mean 50 years) were submitted to undergo percutaneous transluminal angioplasty of the infrarenal aorta. All patients had symptomatic isolated stenotic lesions of the aorta located below the renal arteries and above the bifurcation. Stenoses at bifurcation-level and the iliac arteries were excluded.

METHODS

PTA of the aorta was performed under local anaethesia in the radiological department. Clinical symptoms and ankle/brachial indices were registered before, directly after the procedure and at follow-up. Angiography was performed in all patients pre- and post-procedure, and at follow-up. All patients received angiography in March 1995. Clinical data were analysed based on intention-to-treat.

RESULTS

Initial clinical and angiographic success was achieved in 36 patients (94%). Mean follow-up was 34 months (range 1-92). Recurrent stenosis was seen in seven patients (19%) at follow-up. Only five (13%) of these had recurrent symptoms and were treated successfully with a second PTA. No major complications were seen.

CONCLUSION

These results show PTA to be a safe, minimally-invasive and effective alternative to surgery in case of symptomatic stenosis of the infrarenal abdominal aorta.

Stenting without thrombolysis for aortoiliac occlusive disease: experience in 14 high-risk patients

Stenting without thrombolysis of 16 occluded iliac artery segments and one occluded infrarenal abdominal aorta was attempted in 14 patients. All patients were either considered to be prohibitive operative risks or had contraindications to thrombolytic therapy. Indications for limb reperfusion included rest pain, disabling claudication, or dry gangrene. Successful recanalization was achieved primarily in 13 patients with self-expandable Wallstents, balloon-expandable Palmaz stents, or a combination of the two stents. Follow-up was carried out in all patients in whom recanalization was successful. All stented patients showed symptomatic improvement, and the mean preprocedure ankle/brachial index, which was 0.31, improved to 0.78 after the procedure (p = 0). Complications included a vertebrobasilar stroke during the procedure in one patient, perforation during angioplasty of a stenotic but nonoccluded external iliac artery in one, and dissection of the distal external iliac artery in one. Distal embolization did not occur. Percutaneous recanalization of aortoiliac occlusions without initial thrombolysis is possible and has a high potential for technical success. Additional data and longer follow-up are still needed, but this procedure may provide a reasonable, less invasive option in some patients at high surgical risk or in patients who have contraindications to thrombolytic therapy.