[Percutaneous treatment of a common iliac aneurysm extending to the hypogastric artery with embolization and a covered endoprosthesis]

A case of iliac aneurysm treated percutaneously by endovascular stent graft (Wallgraft - Boston) and transcatheter embolization of internal iliac artery in order to prevent retrograde filling of the aneurysm from the patent hypogastric artery is presented. The initial radiographic evaluation included arteriography, and 2D and 3D spiral CT angiograms. This enabled analysis of the extent of mural thrombus, flow direction, as well as selection of stent graft and coil size. The procedure of embolization and implantation was technically uneventful. Post procedure 3D CT and arteriography demonstrated exclusion of the aneurysm, and return to a normal flow pattern. Follow-up at 6 and 12 months confirmed the stability of the results. Percutaneous treatment of common iliac artery aneurysms involving the hypogastric artery can be performed easily, especially in elderly patients. 3D CT is essential in assessing the endo and extra luminal characteristics of the aneurysm to insure optimal results and to detect complications.

Results of an aortic endograft trial: impact of device failure beyond 12 months

PURPOSE

Analysis endpoints of patient survival and aortic rupture at a reporting interval of 12 months are regularly used to compare endograft aortic aneurysm (EAG) repair to conventional open surgical (COS) repair. This study reports a multicenter EAG repair versus COS repair parallel cohort trial at 12 months and additional observations of specific device failure types and their impact on an aortic endograft design beyond that follow-up period.

METHODS

From August 1997 to September 1998, 240 patients who were treated with bifurcation EAG repairs and 28 patients who were treated with straight EAG repairs were compared with 98 patients who were treated with COS repair for elective infrarenal aortic aneurysm repair. Allocation to treatment was based on aneurysm anatomy. All cohorts underwent infrarenal procedures. Data from concurrent, nonrandomized patient accrual from 17 United States institutions were prospectively gathered and independently adjudicated for safety and efficacy. An independent core laboratory evaluated all imaging data.

RESULTS

There were 308 men and 58 women (mean age, 72 years; range, 42-94 years) treated for infrarenal aortic aneurysm (mean diameter, 55 mm; range, 40-115 mm). Mean preoperative aneurysm diameters were clinically similar (EAG repair, 54 mm vs COS repair, 57 mm). The two cohorts were not significantly different in terms of gender (P = .30) or age (P = .32). EAG repair technical success (aneurysm exclusion, graft patency, patient survival) at 30 days was 89.2%. Five patients required immediate conversion to COS repair, four caused by access complications and one caused by operator-induced EAG repair malposition. The 30-day mortality rate was 1.5% for EAG repair and 3.1% for COS repair (P = .59). The 12-month survival rate was 94.3% for EAG repair and 95.9% for COS repair. The intermediate-term cumulative survival rate at 24 months was 84.9% for EAG repair and 80.3% for COS repair (P = .48). EAG repair device failure occurred from fabric erosion in six patients, with two deaths from ruptured aneurysm at 18 and 28 months after endografting and four device failures resolved by secondary procedures. Five endograft limb dislocations were all resolved by secondary endovascular procedures. Major or minor endograft migration required secondary procedures in five patients, including conversion in two patients.

CONCLUSION

The clinical outcome at 12 months demonstrated effective aneurysm treatment and comparable safety between EAG repair and COS repair by conventional endpoints. Ongoing follow-up beyond 12 months revealed device-related adverse events that required endograft design changes. Diligent surveillance of outcomes beyond 12 months is necessary to adequately evaluate EAG repair devices.

Update on the Talent aortic stent-graft: a preliminary report from United States phase I and II trials

PURPOSE

Phase I and phase II trials were conducted to determine the safety and efficacy of the Talent aortic stent-graft (Medtronic World Medical, Sunrise, Fla) in the treatment of infrarenal abdominal aortic aneurysms (AAA). This is a preliminary report of the technical results and 30-day clinical outcome of these trials.

METHODS

Multicenter prospective trials were conducted to test the Talent stent-graft in high-risk and low-risk patient populations with AAA, including phase I feasibility and phase II clinical trials. The low-risk study included concurrent surgical controls.

RESULTS

In the phase I trial, deployment success was achieved in 92% (23/25 patients), and initial technical success was 78% (18/23 implants without endoleak). The 30-day technical success rate was 96%, with six endoleaks that resolved spontaneously (without need for further intervention); and the 30-day mortality rate was 12% (3/25 patients). The phase II high-risk trial demonstrated a deployment success of 94% (119/127 patients) and an initial technical success of 86% (102/119 implants). The 30-day technical success rate was 96%, and the 30-day mortality rate was 1.5% (2/127 patients). The phase II low-risk trial included a first-generation and a second-generation Talent stent-graft. Deployment success rates were 97% and 99%, respectively, and technical success rates at 30 days were 97% and 96%, respectively. The 30-day mortality rate was 2% in the phase II low-risk first-generation device trial, and the adverse-event rate was 20%. Corresponding figures for the second-generation device were 0% and 1.8%, respectively.

CONCLUSION

The Talent stent-graft can be deployed successfully and achieves endovascular exclusion in a large proportion of patients with AAA. Morbidity and mortality rates are acceptable. One-year clinical results and the comparison with concurrent surgical control subjects remain to be evaluated.

Selecting patients for combined femorofemoral bypass grafting and iliac balloon angioplasty and stenting for bilateral iliac disease

PURPOSE

This study examines the selection of patients for combined femorofemoral bypass (FFB) grafting and iliac balloon angioplasty (IBA) and stenting for bilateral iliac occlusive disease (successively or simultaneously) and the correlation of the length and location of stenoses of the donor iliac artery to the success of FFB grafts.

METHODS

Forty-one patients with long iliac occlusion and significant contralateral iliac stenosis were treated with combined FFB grafting and IBA and stenting, which were performed simultaneously or percutaneously within 1 to 2 days before surgery. Stenting was performed for suboptimal IBAs. IBA/graft patency was evaluated by duplex scanning/ankle-brachial index at 1, 3, 6, and 12 months and every 12 months thereafter. A life-table analysis of patency was performed, according to the length of stenosis as classified by the Society of Cardiovascular Interventional Radiology (group A, < 3 cm and 3-5 cm; group B, > 5 cm).

RESULTS

Indications for surgery were limb salvage (22%), rest pain (44%), and claudication (34%). The mean follow-up time was 34.1 months. Perioperative complications were 7% for group A versus 62% for group B (P = .0007) with no perioperative deaths or amputations. Stenting was needed in 12 of 13 patients (92%) in group B versus four of 28 patients (14%) in group A (P < .0001) and in 11 of 12 external iliac artery lesions versus five of 29 common iliac artery lesions (P < .0001). The overall early success rate was 100% for group A and 62% for group B (P = .0028). The primary patency rates at 1, 2, and 3 years were 96%, 85%, and 85% for group A, respectively, and for group B were 46%, 46%, and 31%, respectively (P < .01). The secondary patency rates for group A at 1, 2, and 3 years were 100%, 96%, and 87%, respectively; and for group B were 62%, 54%, and 27%, respectively (P < .001). The overall primary and secondary patency rates for common iliac and external iliac artery lesions were similar (72% and 72% versus 67% and 75%, respectively). The overall limb salvage rates were 96% for group A and 85% for group B. Seven of 13 patients (54%) of group B, in contrast with 0 of 28 patients in group A, had to undergo a revision of the procedure within 30 days (P < .01).

CONCLUSION

Combined use of IBA and stenting and FFB grafting is effective and durable and can be performed simultaneously, if the donor iliac stenosis length is 5 cm or less. Percutaneous transluminal angioplasty/stenting of stenoses of 5 cm or more fail to support FFB grafting in most patients; therefore, their combination should be questioned.

Ruptured abdominal aortic aneurysms: a personal experience

Despite advances in surgical technique and peri-operative care, mortality from ruptured abdominal aortic aneurysm presenting to a hospital remains around 50%. This is in contrast to the mortality rate of < 5% for elective repair. In a two and a half year period,the principal surgeon operated on 10 patients with ruptured AAA, with a peri-operative and overall mortality of 30%. One of the ten patients had a ruptured mycotic aneurysm. We present our experience with these patients and also correlate this with recent publications.

Improved survival after endoluminal repair with second-generation prostheses compared with open repair in the treatment of abdominal aortic aneurysms: a 5-year concurrent comparison using life table method

PURPOSE

The aim of this study was to compare the outcome of consecutive patients with abdominal aortic aneurysm (AAA) treated concurrently by means of open repair (OR) and endoluminal repair (ER) with second-generation prostheses by the same surgeons during a defined interval.

METHODS

Between May 1995 and December 1998 second-generation (low profile, fully supported, modular) endoprostheses were implanted in 148 patients. These patients, together with 135 patients treated concurrently with OR during the same period, comprised the study group of 283 patients. Patient selection was based on aneurysm morphology. Those patients who were anatomically suitable for ER were treated with this method. The ER and OR groups were similar with regard to age, sex, and size of AAA. The ER group contained high-risk patients considered unfit for OR (n = 46), and the OR group contained high-risk patients who were anatomically unsuitable for ER (n = 19). Outcome criteria in both groups were survival and successful aneurysm repair. Success in the ER group was defined as exclusion of the aneurysm sac and stability or reduction in AAA maximum transverse diameter. Persistent endoleaks were classified as failures, regardless of whether they were subsequently corrected with secondary endovascular intervention. Data were analyzed with the life table method. The minimum period of follow-up for all patients was 18 months.

RESULTS

The perioperative mortality rate was 5.9% in the OR group and 2.7% in the ER group (not significant). There was a statistically significant difference between the survival curves of the two groups in favor of the ER group when analyzed with the log-rank test (P =.004). The Kaplan-Meier curve for graft failure for the ER group revealed a 3-year graft success probability of 82%. Survival probability with successful repair in the OR group at 3 years was 85%.

CONCLUSIONS

A concurrent comparison of ER with second-generation prostheses versus OR demonstrated a significant difference in survival in favor of the ER group. The probability of survival with successful repair at 3 years was similar in both groups.

Concerns for the durability of the proximal abdominal aortic aneurysm endograft fixation from a 2-year and 3-year longitudinal computed tomography angiography study

OBJECTIVE

To provide a long-term perspective on the durability of the proximal abdominal aortic aneurysm endograft fixation from a single device series with perpendicular neck measurements in two groups of patients with complete 2- and 3-year follow-up.

DESIGN

This was a prospective study of postoperative, radiologic images.

SETTING

The study used a referral center, institutional practice, and ambulatory patients.

SUBJECTS

From January 1994 until May 1998, 37 endografts were implanted for abdominal aortic aneurysm. In the first postoperative year, there were four unrelated deaths and six conversions, leaving 27 patients with complete 24-month data and 13 with complete 36-month data.

MAIN OUTCOME MEASURE

Computed tomography angiograms were processed on a work station to measure the neck perpendicular to the central lumen line of the aorta. The surface area at the proximal endovascular anastomosis was recorded at each follow-up interval and related to the postoperative size at the same level.

RESULTS

Significant dilatation of the surface area was found: 20% (16% to 27%) at 24 months (c2 = 30; P < .001, Friedman) and 23% (18% to 28%) at 36 months (c2 = 27; P < .001, Friedman). This increase in neck size was continuous and linear, with a yearly rate of approximately 10% surface area; translated into diameter, this approximates 1 mm/y.

CONCLUSION

A continuous aortic enlargement of approximately 1 mm/y at the level of the proximal endovascular anastomosis was found. Because of the practice of oversizing the endograft relative to the infrarenal aortic neck, a loss of the endovascular seal may not become apparent until several years after endovascular abdominal aortic aneurysm repair is performed.

Evaluation of the TriSpan neck bridge device for the treatment of wide-necked aneurysms: an experimental study in canines

BACKGROUND AND PURPOSE

Many wide-necked aneurysms are difficult or impossible to treat with the Guglielmi detachable coil (GDC). The purpose of this study was to evaluate the use of a neck bridging device, the TriSpan coil, in combination with standard GDCs for the treatment of wide-necked aneurysms in an experimental canine aneurysm model.

METHODS

Of 24 experimental aneurysms in 12 animals, 19 (7 lateral and 12 terminal) were treated with the TriSpan coil in conjunction with standard GDCs. Digital subtraction angiography (DSA) was performed on all animals immediately after treatment. In 6 animals, follow-up DSA and histological evaluation were performed 4 weeks after treatment. In the remaining 6, DSA was done at both 90 and 180 days after treatment. Histological evaluation was done immediately after the 180-day angiographic evaluation.

RESULTS

The TriSpan was easy to use in conjunction with the standard GDC. Because of their geometry, some lateral aneurysms were difficult or impossible to treat with this device. Greater than 90% aneurysm occlusion was obtained in all 19 aneurysms. In no instance was there evidence of coil migration, herniation, or aneurysm recanalization. Histological evaluation of the tissue surrounding the TriSpan coil showed tissue responses similar to that seen with standard GDCs.

CONCLUSIONS

These results show that the TriSpan coil in conjunction with standard GDCs can be used safely and effectively for the treatment of wide-necked aneurysms in this canine model. Positioning and deployment of the neck bridge in aneurysms having an acute angle with the long axis of their parent artery are difficult or impossible. It is likely that this device, used in conjunction with the standard GDC, will allow treatment of some wide-necked aneurysms that are not treatable with the GDC alone.

Midterm durability of abdominal aortic aneurysm endograft repair: a word of caution

PURPOSE

Endograft technology for abdominal aortic aneurysm (AAA) repair is being applied more liberally. There is little information about the midterm performance of these grafts. This study is focused on follow-up interventions after endograft repair for AAA.

METHODS

Prospective follow-up analysis of a consecutive patient series (n = 173 patients) at a single center who underwent endovascular AAA repair up to 50 months after operation. Seventeen percent of the patients were regarded unfit for open surgery. Four types of commercially available grafts were used. The Society for Vascular Surgery/International Society for Cardiovascular Surgery guidelines were applied for endograft implantation and data preparation.

RESULTS

In two patients, the procedure was converted to open surgery. In one procedure, emergency repair for iliac artery rupture was performed. The 30-day mortality rate was 2.8% (n = 5 patients). An early second procedure to correct type I endoleaks was necessary in 8 cases (4.6%; 3-10 days). The following midterm results were obtained: median follow-up of the 166 remaining patients was 18 months (range, 1-50 months); 50 additional procedures were necessary in 37 patients (22.3%) for the treatment of leaks (n = 45 interventions) or to maintain graft patency (n = 5 grafts; four patients with concomitant graft segment disconnection); and 46% of the reinterventions were performed within the first year of follow-up and 74% of the reinterventions were performed within the second year of follow-up. One patient died after emergency surgery for rupture as the result of a secondary endoleak at 1 year. Although seven interventions (14%) were performed for type II endoleak, no serious complications were related to patent sidebranches. There was no statistically significant difference between the need for maintenance in different graft configurations (tubular, bifurcated, aorto-uniiliac), or number of graft segments (1, 2, 3-4, > or = 5 segments). New generation grafts (after 1996) performed better than early generation grafts (P = 0.04, chi-squared test) with regard to endoleak development.

CONCLUSION

Endograft repair for AAA is safe but, with current technology, not as durable as open repair. Our data suggest that the use of endograft repair for AAA is becoming safer as endograft design improves. Nevertheless in 26.6% of the patients, there is need for reintervention within midterm follow-up. Close follow-up is crucial because late leaks may develop after more than 2 years after the initial procedure. Endoluminal repair should therefore be applied with caution, strict indication, and only if a tight follow-up is warranted. These findings may also affect health care reimbursement policies.

The Hemobahn endoprosthesis: a self-expanding polytetrafluoroethylene-covered endoprosthesis for the treatment of peripheral arterial occlusive disease after balloon angioplasty

Endoluminal management of occlusive arterial disease has previously been limited to balloon angioplasty, either alone or with stent placement. This article discusses the Hemobahn endoprosthesis, a polytetraflouroethylene-covered nitinol stent graft. The Hemobahn device design characteristics, Food and Drug Administration phase I feasibility trial design and results, phase II pivotal trial design, and single-site phase II trial results are reviewed. The long-term outcomes of patients treated with angioplasty and Hemobahn stent grafting will determine the role of stent grafting in the management of occlusive arterial lesions below the aortic bifurcation.

Coronary stenting and platelet glycoprotein IIb/IIIa receptor blockade in acute myocardial infarction

BACKGROUND

Myocardial reperfusion in patients with acute myocardial infarction may be successfully achieved with primary angioplasty. However, angioplasty, as a primary reperfusion strategy, has limitations such as early recurrent ischemia and late restenosis and reocclusion. To improve the short- and long-term results of primary angioplasty, the use of adjunct strategies has been proposed.

METHODS

We reviewed published studies on the effectiveness of primary angioplasty, stenting, and platelet glycoprotein IIb/IIIa receptor blockade and identified the advantages and disadvantages of these interventions in patients with acute myocardial infarction.

RESULTS

Recent findings suggest that patients may benefit from stenting of the infarct artery and from the use of more potent antiplatelet agents such as platelet glycoprotein IIb/IIIa receptor inhibitors. In randomized trials that compared primary angioplasty versus primary stenting, stent implantation was associated with a lower rate of death, reinfarction, and especially target vessel revascularization. Platelet glycoprotein IIb/IIIa receptor inhibitors prevented acute ischemic complications after primary angioplasty and primary stenting. In addition to maintaining large vessel patency, these drugs may protect the microvasculature after primary stenting, allowing better functional recovery of the risk area.

CONCLUSIONS

Coronary artery stenting in acute myocardial infarction reduces the rate of restenosis and the incidence of problems related to recurrent ischemia. Platelet glycoprotein IIb/IIIa receptor inhibitors may come to play a key role in association with mechanical reperfusion. However, the cost-effectiveness and long-term clinical outcome of this combined pharmacologic/mechanical intervention require further study before this strategy can be recommended for routine use.

Aorto-uni-iliac endograft for complex aortoiliac aneurysms compared with tube/bifurcation endografts: results of the EVT/Guidant trials

OBJECTIVE

Our objective was to present the results of the multicenter EVT/Guidant aorto-uni-iliac trial and to compare them with the tube, bifurcated graft, and open control series in regard to patient demographics, medical comorbidity, 30-day morbidity/mortality, and outcome at 1 year.

METHODS

One hundred twenty-one patients not eligible for tube or bifurcated endografts were entered into the aorto-uni-iliac trial (A-I). These were compared with 153 patients in a tube (T) group, 268 patients in a bifurcated endograft (BI) group, and 111 patients in an open control (C) group. All data were audited and independently analyzed for presentation to the Food and Drug Administration.

RESULTS

Group demographics were similar with the following exceptions. Aneurysm diameter was significantly less in the T group (51.2 mm) but similar for the A-I (57 mm), BI (54.6 mm), and C (55.6 mm) groups (P < .001). There were more male patients in all endograft groups (A-I 92.6%, BI 89.5%, T 85.6% vs 76.6% for C, P = .002). Peripheral arterial occlusion was present more frequently in the A-I group (25.6% vs 13.8% BI, 10.5% T, and 10.8% C, P = .003). However, no differences were found in mean age, incidence of coronary artery disease, and American Society of Anesthesiologists III/IV classification. Implantation was achieved in 94.2% of the A-I group, 90.3% of the BI group, and 92% of the T group. No significant difference was seen in the operative mortality rate (4.2% A-I, 2.6% BI, O% T, 2.7% C). Postoperative cardiac complications were similar for the A-I (22%) and C (20.7%) groups but significantly less for the BI and T groups (13.4% and 10.5%, P = .019), whereas pulmonary problems were significantly reduced in all endograft groups (A-I 11.9%, BI 10.1%, and T 7.2% vs 22.5% for C, P = .002). Transient renal dysfunction occurred in 6.8% of the A-I group and 8.2% of the BI group but in only 3.3% of the T group and 1.8% of the C group (P = .028). Operating time was significantly longer for the A-I group than for the BI, T, or C groups (258 minutes vs 156, 179, and 174 minutes). Median blood loss, intensive care unit use, and hospital stays were markedly and significantly reduced in all endograft groups compared with the control group. The incidences of type I endoleak at 1 year were 2.4% A-I, 2.3% BI, and 3.8% T, and no ruptures occurred in any of the patients treated with endografts. No femoral-femoral graft thromboses occurred in the A-I group.

CONCLUSION

Despite the fact that patients with combined aortic and iliac aneurysms have a more complex repair requirement and have an increased rate of comorbidity, the results are competitive with endovascular repair of aortic aneurysm by tube and bifurcated graft systems and are associated with a lower morbidity than open operation.

Management of ectatic, nonaneurysmal iliac arteries during endoluminal aortic aneurysm repair

PURPOSE

Most endografts for an endoluminal AAA repair cannot achieve an adequate hemostatic seal in ectatic common iliac arteries larger than 14 mm. The extension of the endograft into the external iliac artery can alleviate this problem but requires sacrifice of the internal iliac artery. We have used the larger diameter aortic extension cuff to obtain adequate endograft to arterial wall apposition in patients with ectatic, nonaneurysmal common iliac arteries. Because of the resultant flared configuration of the iliac limb, the technique is termed bell-bottom. However, it is unknown whether subsequent enlargement of these ectatic common iliac arteries that will lead to endoleaks or endograft migration will occur.

METHODS

The records of all 96 patients who have undergone endoluminal abdominal aortic aneurysm repair at our institution were reviewed. Fourteen patients were identified in whom aortic extension cuffs were placed into 18 ectatic (>14 mm, but <20 mm) common iliac arteries. The mean follow-up time was 14 months (range, 6-24 months). The maximal diameter of the common iliac artery on computed tomography scan before endograft placement was compared with the maximal diameter at the most recent follow-up. The incidence of endoleaks, ruptures, and endograft migration related to the "bell-bottom" technique were recorded.

RESULTS

The mean preoperative common iliac artery diameter was 18 mm (range, 15-20 mm). Aortic extension cuffs of 20-mm diameter and 24-mm diameter were used in 14 and 4 common iliac arteries, respectively. The diameter did not change in 11 common iliac arteries (61%), increased by 1 mm in 4 common iliac arteries (22%), and decreased by 1 mm in 3 common iliac arteries (17%). No endoleaks, ruptures, or endograft migration related to this technique was identified.

CONCLUSION

The use of aortic extension cuffs for ectatic common iliac arteries expands the number of patients who can be treated endoluminally without sacrifice of the internal iliac artery. Most common iliac arteries do not increase in diameter. When enlargement occurs, the degree of dilation is minimal. Therefore, the "bell-bottom" technique appears to be an acceptable option in the management of large, nonaneurysmal iliac vessels during endoluminal abdominal aortic aneurysm repair.

Gender-related differences in infrarenal aortic aneurysm morphologic features: issues relevant to Ancure and Talent endografts

PURPOSE

The purpose of this study was to determine whether gender-related anatomic variables may reduce applicability of aortic endografting in women.

METHODS

Data on all patients evaluated at our institution for endovascular repair of their abdominal aortic aneurysm were collected prospectively. Ancure (Endovascular Technologies (EVT)/Guidant Corporation, Menlo Park, Calif) and Talent (World Medical/Medtronic Corporation, Sunrise, Fla) endografts were used. Preoperative imaging included contrast-enhanced computed tomography and arteriography or magnetic resonance angiography.

RESULTS

One hundred forty-one patients were evaluated (April 1998-December 1999), 19 women (13.5%) and 122 men (86.5%). Unsuitable anatomy resulted in rejection of 63.2% of the women versus only 33.6% of the men (P = .026). Maximum aneurysm diameter in women and men were similar (women, 56.94 +/- 8.23 mm; men, 59.29 +/- 13.22 mm; P = .5). The incidence of iliac artery tortuosity was similar across gender (women, 36.8%; men, 54.9%; P = .2). The narrowest diameter of the larger external iliac artery in women was significantly smaller (7.29 +/- 2.37 mm) than in men (8.62 +/- 2.07 mm; P = .02). The proximal neck length was significantly shorter in women (10.79 +/- 12.5 mm) than in men (20.47 +/- 19.5 mm; P = .02). The proximal neck width was significantly wider in women (30.5 +/- 2.4 mm) than in men (27.5 +/- 2.5 mm; P = .013). Proximal neck angulation (>60 degrees) was seen in a significantly higher proportion of women (21%) than men (3.3%; P = .012). Of the patients accepted for endografting, a significantly higher proportion of women required an iliofemoral conduit for access (women, 28.6%; men, 1.2%; P = .016).

CONCLUSION

Gender-related differences in infrarenal aortic aneurysm morphologic features may preclude widespread applicability of aortic endografting in women, as seen by our experience with the Ancure and Talent devices. In addition to a significantly reduced iliac artery size, women are more likely to have a shorter, more dilated, more angulated proximal aortic neck.

The Ancure endografting system: an update

The Ancure endografting system (Guidant Cardiac and Vascular Division, Menlo Park, Calif) features a unibody, nonsupported woven polyester graft designed to treat abdominal aortic aneurysms. It is constructed in tube, bifurcated, and aortoiliac configurations. The attachment system consists of a frame with four independent V-shaped double hooks that penetrate the arterial wall for fixation. There are separate attachment systems at the proximal and distal ends of the endoprosthesis. In September 1999, the Food and Drug Administration (FDA) approved the tube and bifurcated devices for general use. The aortoiliac device is under present consideration of the FDA. Phase II and III clinical trials of the system enrolled over 870 patients from the end of 1995 to the summer of 1999. The device was deployed successfully in 90% to 96% of cases, depending on the configuration and the phase of the trial. Mortality rates were similar to those of concurrent open surgical control rates, but serious morbidity was reduced. Long-term follow-up of the bifurcated group from phase II showed only one migration and no ruptures. Aneurysm size reduction in this group was noted in 51.3% of patients at 1 year and 68.5% at 2 years. In the same subset, type I endoleaks were noted in 2.7% at 1 year and 1.3% at 2 years. All postoperative imaging studies were reviewed by a core laboratory facility. The advantages of the ancure system include solid fixation, flexibility in accommodating morphologic changes, and excellent long-term clinical performance. The disadvantages include a large introducer system and the potential for limb obstruction by compression or angulation. However, limb compromise responds well to intraluminal stenting. The expected FDA approval of the aortoiliac device and a larger variety of graft sizes should expand the number of patients who can be treated with this system.

Is proximal aortic neck dilatation after endovascular aneurysm exclusion a cause for concern?

PURPOSE

The purpose of this study was to evaluate the extent and frequency of dilatation of the proximal aortic neck over time after endovascular exclusion of abdominal aortic aneurysms and the effect on the continued integrity of the repair.

METHODS

Patients enrolled in the multicenter tube and bifurcated trials of the Guidant-Endovascular Technologies Ancure endografting system and at least 1 year of follow-up were reviewed. Neck diameter measurements were obtained from computed tomography scans that were obtained with and without contrast by an independent core laboratory facility. The diameter was considered to be the minor axis of the first slice at which point at least one half of the proximal attachment frame was located. A change exceeding 2.5 mm was considered to be significant.

RESULTS

At 1 year, 13% of the patients (42/314 patients) showed evidence of proximal neck dilatation, with a mean diameter increase of 4.8 +/- 2.4 mm. The proportion of patients with dilatation increased to 21% at 2 years (48/226 patients) and 19% at 3 years (11/59 patients). The initial presence of an endoleak, the neck length, and the aneurysm size had no clear effect on the development of neck enlargement. Initial neck diameter was inversely related to and the strongest predictor of later dilatation. Graft oversizing was not an independent predictor of neck dilatation on multivariate analysis. Only one migration of the proximal attachment system was observed during follow-up.

CONCLUSION

Most proximal aortic necks remain stable, but approximately 20% of necks increase in diameter by 2 years. Smaller necks dilate more often than larger ones. This effect is independent from the frequent oversizing of grafts in smaller necks. The integrity of the repair remains good at 3 years of follow-up.

Update on the bifurcated EXCLUDER endoprosthesis: phase I results

Many devices are being investigated for treatment of infrarenal abdominal aortic aneurysms. This report describes the particular characteristics of a next generation modular endograft and the Phase I results in 29 patients. Larger comparative studies are in progress to assess the safety and efficacy of this new design.

Mid-term results after endovascular repair of the abdominal aortic aneurysm

PURPOSE

As a minimally invasive strategy for the treatment of patients with abdominal aortic aneurysm (AAA), endovascular repair has been embraced with enthusiasm because of the promise of achieving a durable result with a reduced risk of perioperative morbidity and mortality. Our mid-term experience with endovascular AAA repair was assessed by examining early and late clinical outcome in concurrent cohorts of patients stratified either as low-risk or as at increased-risk for intervention.

METHODS

From April 1994 to December 1999, endovascular AAA repair was performed in 104 patients with commercially available systems. A subset of patients considered at increased risk for intervention (n = 51) were categorized as such based on a pre-existing history of ischemic coronary artery disease (73%), with documentation of myocardial infarction (57%) or congestive heart failure (29%), or because of the presence of chronic obstructive pulmonary disease, liver disease, or malignancy.

RESULTS

The perioperative mortality rate (30-day) was 7.8% for patients at increased risk compared with 1.9% among those classified as low-risk (P = NS). There was no difference between groups in age (72 +/- 7 years vs 74 +/- 7 years; mean +/- SD), surgical time (221 +/- 90 minutes vs 192 +/- 68 minutes), blood loss (437 +/- 402 mL vs 331 +/- 238 mL), postoperative hospital stay (4.4 +/- 2.7 days vs 4.2 +/- 2.5 days), or days in the intensive care unit (1.2 +/- 1.6 days vs 0.6 +/- 1.3 days). Patients at increased risk of intervention had larger aneurysms than patients at low risk (58 +/- 11 mm vs 52 +/- 12 mm; P < .05). Stent grafts were successfully implanted in 47 (92%) patients at increased risk versus 50 (94%) patients at low risk (P = NS). Conversion rates to open operative repair were similar in increased-risk and low-risk groups at 3.9% and 5.7%, respectively. The initial endoleak rate was 21% versus 18% based on the first computed tomography performed (either at discharge or 1 month; P = NS). To date, patients at increased risk have been monitored for 14.6 +/- 12.4 months, and patients at low risk have been monitored for 17.7 +/- 15.0 months. Kaplan-Meier analysis for cumulative patient survival demonstrated a reduced probability of survival among those patients initially classified as at increased risk for intervention (P < .05, Mantel-Cox test). Both cohorts had similar 2-year clinical success rates of approximately 75%.

CONCLUSION

Despite the use of an endovascular approach for aneurysm treatment, the risk of perioperative death and morbidity remains present for all patients including those who have no significant medical comorbidity. Moreover, although clinical success rates are comparable in both patient groups, 2 years after endovascular repair was performed, at least one in four patients was classified as a clinical failure. Given the continued uncertainty associated with clinical outcome and the need for close life-long surveillance, caution is dictated in advocating endovascular treatment for the patient who is otherwise considered an ideal candidate for standard open surgical repair.

The AneuRx stent graft: four-year results and worldwide experience 2000

OBJECTIVE

The objective was to review the current results of endovascular abdominal aortic aneurysm repair with the AneuRx stent graft and to determine the effectiveness of the device in achieving the primary objective of preventing aneurysm rupture.

METHODS

The outcome of all patients treated during the past 4 years in the U.S. AneuRx clinical trial was determined, and the worldwide clinical experience was reviewed.

RESULTS

A total of 1192 patients were treated with the AneuRx stent graft during all phases of the U.S. Clinical Trial from June 1996 to November 1999, with follow-up extending to June 2000. Ten (0.8%) patients have had aneurysm rupture, with most ruptures (n = 6) occurring in 174 (3.4%) patients treated with an early stiff bifurcation stent graft design used in phase I and in the initial stages of phase II. Since the current, flexible, segmented bifurcation stent graft design was introduced, four (0.4%) ruptures have occurred among 1018 patients treated. Of these, one was during implantation, two were placed too far below the renal arteries, and one patient refused treatment of a type I endoleak. Kaplan-Meier analysis of all 1192 patients treated with the AneuRx stent graft including both stent graft designs revealed the patient survival rate to be 93% at 1 year, 88% at 2 years, and 86% at 3 years, freedom from conversion to open repair to be 98% at 1 year, 97% at 2 years, and 93% at 3 years, and freedom from secondary procedure to be 94% at 1 year, 92% at 2 years, and 88% at 3 years. Freedom from aneurysm rupture with the commercially available segmented bifurcation stent graft was 99.7% at 1 year, 99.5% at 2 years, and 99.5% at 3 years. The presence or absence of endoleak on contrast computed tomography scanning after stent graft placement was not found to be a significant predictor of long-term outcome measures. Worldwide experience with the AneuRx device now approaches 10,000 patients.

CONCLUSIONS

Endovascular management of abdominal aortic aneurysms with the AneuRx stent graft has markedly reduced the risk of aneurysm rupture while eliminating the need for open aneurysm surgery in 98% of patients at 1 year and 93% of patients at 3 years. The device was effective in preventing aneurysm rupture in 99.5% of patients over a 3-year period. The overall patient survival rate was 93% at 1 year and 86% at 3 years.

Computed tomography assessment of abdominal aortic aneurysm morphology after endograft exclusion

OBJECTIVES

Assessment of the long-term function of endografts to exclude abdominal aortic aneurysm (AAA) includes determination of aneurysm dimensions and morphologic changes that occur after implantation. This study reports the dimensional analysis of patients treated with AneuRx bifurcated endoprostheses with postintervention, 1-year (n = 51), 2-year (n = 28), and 3-year (n = 10) postimplantation contrast computed tomography data.

METHODS

Maximal diameter (D) and cross-sectional area (CSA) of the AAA were measured from axial computed tomography images. Total volume, AAA thrombus volume (AAA volume minus the volume of the device and luminal blood flow), diameter of the aorta at the level of the renal arteries and within the device, distance from the renal arteries to the device, length of the device limbs, and the angle of the proximal neck were also determined at the same follow-up intervals after deployment with computed tomography angiograms reconstructed in an interactive environment.

RESULTS

Fifty-one of 98 consecutively treated patients with the AneuRx bifurcated prosthesis (29 "stiff" and 22 "flexible" body devices) had complete data from the postprocedure and follow-up computed tomography studies available for analysis. Max D, CSA, total volume of the AAA, and AAA thrombus volume decreased sequentially from year to year compared with the postimplantation values. D and CSA decreased or were unchanged in all except four patients, two who had unrestricted enlargement of the aneurysm with eventual rupture and one who had surgical conversion for continued expansion despite four diagnostic angiograms and attempted embolizations. Total volume of the AAA increased in 11 of 51 patients at 1 year, eight of whom had endoleaks at some interval during the follow-up. Thrombus volume increased more than 5% in four of these patients, including the two with eventual rupture and the one conversion. Patients with endoleaks who had spontaneous thrombosis or were successfully treated either remained at the same volume or had decreased volume on subsequent examinations. D at the renal arteries increased an average of 0.9 mm during the first year, with a concomitant increase of 2.8 mm within the proximal end of the device related to the self-expanding nature of the Nitinol suprastructure. Subsequent enlargement of the proximal neck continued at a slow rate in some cases but never exceeded the diameter of the endoluminal device. The distance from the renal arteries to the device increased by an average of 3 mm over the first year, with the greatest increases occurring in patients with a "stiff" body device and those with rapid regression (>10% total volume) in 1 year. As regression of the AAA occurred, the angle of the proximal neck varied from -5 degrees to +25 degrees from the original alignment. Limb length varied from -8 mm to +10 mm, with no consistent pattern for the change, that is, ipsilateral or contralateral limb.

CONCLUSION

Significant variation in the quantitation of aneurysm size occurs depending on the technique of computed tomography assessment used. In most patients diameter assessment is adequate, although volumetric analysis appears to be very helpful in certain patients who do not show aneurysm regression, or in whom the diameter increases or where endoleaks persist. Three-dimensional reconstruction and volumetric analysis are also useful to assess the mechanism by which the endovascular device accommodates to morphology changes and to determine criteria for reintervention.

Carotid artery stenting: utility of cerebral protection devices

Neurologic deficits secondary to embolic events have been the most significant concern regarding carotid bifurcation stenting. Experimental studies utilizing human carotid plaques have shown that embolic particles were released from all specimens. In addition, transcranial Doppler studies have confirmed the fact that multiple emboli are released during each case. Preliminary experiences with the use of cerebral protection devices for carotid stenting have shown encouraging results with embolic particles recovered from each case, although these experiences have also revealed some of the down sides of its use. The present article provides the rationale for routine use of these protection devices and also reviews various protection devices, some of which are currently undergoing clinical trials.

Successful stent delivery through 5 French guiding catheter

BACKGROUND AND OBJECTIVE

In vessels with moderate-severe tortuosity, rigidity or calcium, 6 French guiding catheters may be of help in stent delivering, allowing a deep coronary intubation and, hence, an easier coronary stent advancement. In this study, we describe our experience in coronary stenting using 5 French guiding catheters.

METHODS AND RESULTS

The study population is constituted by 46 patients in whom coronary stenting was attempted through a 5 French guiding catheter. Sixty-six stents were delivered in 56 vessels; the 5 French Zuma guiding catheter (MedtronicAVE, Minneapolis, Minnesota) was used. In 74% of cases, a moderate-severe tortuosity was present, and calcium was visible by fluoroscopy in 27%. The stented lesions were de novo in 95%, and 42% of stents were placed in the right coronary artery. The stent was successfully delivered and implanted in all but one case (98.5%). In one patient with severe vessel tortuosity, a successful balloon dilation was performed, but the stent could not be successfully advanced through the coronary artery to the left anterior descending, and could be retrieved without any complication. Changing to a larger size guiding catheter was not required in any patient. Balloon predilation was performed before coronary placement in 41 of the 66 stents (62.1%), whereas stents were directly implanted without balloon predilation in the remaining 25 cases (37.9%).

CONCLUSION

Coronary stenting through 5 French guiding catheters is feasible. This strategy may be especially indicated in patients with moderate-severe vessel tortuosity.

Emergency polytetrafluoroethylene-covered stent implantation to treat coronary ruptures

BACKGROUND

Coronary perforation is a life-threatening complication of percutaneous interventions. In the past few years, the implantation of covered stents has emerged as a strategy for treatment when the traditional conservative approach (ie, prolonged balloon inflation and reversal of anticoagulation) fails.

METHODS AND RESULTS

Since May 1997 (when polytetrafluoroethylene [PTFE]-covered stents were available at our institutions), 11 of the 12 consecutive patients who had coronary ruptures that were unsuccessfully sealed with prolonged balloon inflation and reversal of anticoagulation were treated with 12 PTFE-covered stents (PTFE group). The efficacy of the PTFE-covered stent was compared with that of noncovered stents, which were used to treat 17 perforations (non-PTFE group). One patient sustained a very distal perforation that was not suitable for covered stent sealing and underwent emergency surgery. All vessel ruptures treated with PTFE-covered stent implantation were successfully sealed. The time necessary to deploy the stent was 10+/-3 minutes (range, 4 to 15 minutes). All patients but one were discharged from the hospital and had an optimal early clinical outcome. One patient underwent emergency bypass surgery and died in the intensive care unit. The occurrence of cardiac tamponade and the necessity for emergency surgery was significantly lower in the PTFE group than in the non-PTFE group. At 14+/-4 months, the 10 discharged patients had not experienced any major adverse cardiac events.

CONCLUSIONS

This preliminary study supports the utility of the PTFE-covered stent for the nonsurgical treatment of vessel ruptures.