Morphology and Computational Fluid Dynamics Support a Novel Classification of Common Iliac Aneurysms.

OBJECTIVE: Isolated common iliac artery aneurysms (CIAAs) are uncommon, and evidence concerning their development, progression, and management is weak. The objective was to describe the morphology and haemodynamics of isolated CIAAs in a retrospective study. METHODS: Initially, a series of 25 isolated CIAAs (15 intact, 10 ruptured) in 23 patients were gathered from multiple centres, reconstructed from computed tomography, and then morphologically classified and analysed with computational fluid dynamics. The morphological classification was applied in a separate, consecutive cohort of 162 patients assessed for elective aorto-iliac intervention, in which 55 patients had intact CIAAs. RESULTS: In the isolated CIAA cohort, three distinct morphologies were identified: complex (involving a bifurcation); fusiform; and kinked (distal to a sharp bend in the CIA), with mean diameters of 90.3, 48.3, and 31.7 mm, and mean time averaged wall shear stresses of 0.16, 0.31, and 0.71 Pa, respectively (both analysis of variance p values < .001). Kinked cases vs. fusiform cases had less thrombus and favourable haemodynamics similar to the non-aneurysmal contralateral common iliac artery (CIA). Ruptured isolated CIAAs were large (mean diameter 87.5 mm, range 55.5-138.0 mm) and predominantly complex. The mean CIA length for aneurysmal arteries was greatest in kinked cases followed by complex and fusiform (100.8 mm, 91.1 mm, and 80.6 mm, respectively). The morphological classification was readily applicable to a separate elective patient cohort. CONCLUSION: A new morphological categorisation of CIAAs is proposed. Potentially this is associated with both haemodynamics and clinical course. Further research is required to determine whether the kinked CIAA is protected haemodynamically from aneurysm progression and to establish the wider applicability of the categorisation presented.

Nesiritide protects endothelial function after balloon-induced trauma in the iliac artery in rabbits

To assess the effect of nesiritide on the endothelial function of iliac arteries following endothelia trauma. Right iliac artery trauma was created with a balloon catheter. Ten rabbits were treated with a 4-week subcutaneous injection of nesiritide at a fixed daily dose of 0.1mg/kg. Ten rabbits received daily normal saline injection. Plasma endothelin 1 (ET-1), nitric oxide (NO), and Von Willebrand Factor (vWF) were measured before and after the therapies. Tissue proliferating cell nuclear antigen (PCNA) was measured after the treatment. After the treatment, in the therapeutic group, the area under internal elastic membrane and the residual lumen area were higher than in the normal saline group (P <0.05). The plasma levels of ET-1 (91.6±6.8 vs 114.9±6.3 ng/L, P =0.001), vWF (134.6±10.8% vs 188.8±10.4%, P =0.001) and the ratio of PCNA positive expression (11.7±4.2% vs 36.2±11.4%, P =0.005) in the therapeutic group was lower than in the normal saline group, while the plasma levels of NO was higher (89.7±9.3 vs 43.5±5.3 µmol/L, P =0.001). Nesiritide inhibited remodeling of rabbit iliac artery following endothelial trauma. The inhibition of vascular remodeling may be related to the alleviated endothelial dysfunction and reduced expression of tissue proliferating cell nuclear antigen

Isolated common iliac artery aneurysms: a revised classification to assist endovascular repair.

Isolated common iliac artery aneurysms (CIAAs) are relatively rare; they typically progress asymptomatically and are revealed incidentally, usually after they have acquired significant dimensions. Traditional open reconstruction is associated with high morbidity and mortality rates. Rupture is a common initial manifestation. Endovascular repair has been proposed as a minimally invasive alternative, associated with lower morbidity and mortality rates, even in patients at high surgical risk; some specialists have recently proposed endoluminal repair as the first-choice procedure in suitable anatomies. However, only a few sporadic attempts have been made to define the "suitable" anatomy for endovascular repair. This article proposes a classification of isolated CIAAs and provides endovascular specialists with a guide to deciding which type of repair is feasible and efficacious according to the anatomical configuration of the aneurysm.

Descending thoracic and thoracoabdominal aortic aneurysm repair: 15-year results using a uniform approach.

This review presents the results of surgical repair of descending thoracic (DT) and thoracoabdominal aortic (TAA) aneurysms, using spinal drainage (SD) distal aortic perfusion (DAP), and other adjuncts intended to reduce complications. Records of patients undergoing repair of DT and TAA between 1986 and 2002 were reviewed. Elective operations were performed using single lung ventilation, invasive monitoring, SD, modest anticoagulation, permissive hypothermia (> or = 33 degrees F), liberal use of transaortic endarterectomy, and complete repair. Intercostal arteries were reimplanted when possible and DAP was used in DT and TAA types I, II, and III repair. Exceptions to this approach were noted. Some of these adjuncts were used in emergency cases. Actuarial survival was calculated. Fifty consecutive patients with DT (3) or TAA (47), type I (4), type II (16), type III (18), or type IV (9), aneurysms received elective (36) or emergency (14) repair between 1986 and 2002. Mortality was 2/36 (5.5%) in the elective group. In the emergency group, there were 2 intraoperative deaths and mortality was 4/14 (28.5%, p < 0.07). Overall survivor morbidity was 6/34 (17.6%) in elective and 7/10 (70%, p < 0.02) in emergency cases. Paraplegia occurred in one patient in the elective group (2.7%) with dissecting type II TAA aneurysm in whom the intercostal patch was sacrificed. Two of 12 initial survivors developed paraplegia in the emergency group (16.7%); one had SD but neither had DAP or intercostal reimplantation. Serious complications were associated with avoidable deviations from the approach. Five and 10-year survival for the entire series was 64.8% and 46.4%, respectively. These results parallel those in contemporary reports from centers where repair of descending and thoracoabdominal aortic aneurysm is frequently performed. Good long-term results can be achieved using spinal drainage and distal aortic perfusion, combined with other adjuncts as a means of reducing complications. When possible, the same approach should be used in emergency cases.

Endovascular therapeutic options for isolated iliac aneurysms with a working classification.

The purpose of this paper is to demonstrate a variety of stent-grafting and embolization techniques and describe a new classification for endovascular treatment of isolated iliac artery aneurysms. A total of 19 patients were treated for isolated iliac aneurysms. Depending on the proximal iliac neck and the uni-/bilaterality of common iliac artery aneurysms (CIAA's) the patient may be treated by a tube (Type Ia) or a bifurcated stent-graft (Type Ib) in addition to internal iliac artery embolization. Neck anatomy is also critical in determining therapeutical options for internal iliac artery aneurysms (IIAA's). These are tube stent-grafting plus internal iliac branch embolization (Type IIa), coiling of afferent and efferent internal iliac vessels (Type IIb) and IIAA packing (Type IIc). The average length of stay for these procedures was 3.8 days. During the mean follow-up of 20.9 months, aneurysm size remained unchanged in all but 4 patients. Reinterventions were necessary in option Type Ib (3/8 pat.) and Type Ia (1/7 pat.) due to extender stent-graft migration (n = 2) or reperfusion leaks (n = 2). We conclude that Iliac artery aneurysms may be successfully and safely treated by a tailored approach using embolization or a combination of embolization and stent-grafting. Long-term CT imaging follow-up is necessary, particularly in patients treated with bifurcated stent-grafts (Type Ib).

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.

Expansion rates and outcomes for iliac artery aneurysms.

PURPOSE: The expansion rates and outcomes of iliac artery aneurysms (IAAs) were determined. METHODS: A retrospective chart review was conducted to identify patients in whom IAAs had been diagnosed between June 1990 and March 1999 in a vascular surgery service at a large university-affiliated Veterans Affairs medical center. The patients were veterans, 187 men and two women, in whom the diagnosis of an IAA was made, as defined by the Ad Hoc Committee on Reporting Standards of The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter (IAA >/= 1.5 cm). Expansion rates relative to the size of IAAs and clinical outcomes were noted for all patients. RESULTS: One hundred eighty-nine patients (mean age, 72.3 +/- 0.5 years) with 323 IAAs (mean size, 2.34 +/- 0.7 cm) were found. The mean follow-up (96% of patients with B mode ultrasound scanning) period was 31.4 months, with each patient undergoing a mean of 4.2 studies. The 4-year life-table survival rate was 78.2%, with no patient deaths related to their IAAs. Symptoms were noted in six of 189 patients (3.1%; two ruptures, four chronic pain), who all had IAAs larger than 4 cm. IAAs were repaired in 34 of 189 patients (18%), in 25 of the 34 patients because of their associated abdominal aortic aneurysms and in nine of 34 patients because of their IAAs alone. All nine patients requiring operative treatment of indications related to the IAA had an IAA larger than 4 cm. Expansion rates were slow for IAAs smaller than 3 cm (0.11 +/- 0.02 cm/year) and significantly greater (P <.003) for IAAs 3 to 5 cm (0.26 +/- 0.1 cm/year). The correlation between B mode ultrasound scanning and computed tomography scanning was excellent. The size of the IAAs was underestimated by 0.03 +/- 0. 06 cm by means of B mode ultrasound scanning. CONCLUSION: The IAAs followed up by this contemporary Veterans Affairs vascular surgery service were small, rarely caused symptoms or rupture, and expanded at a slow rate. IAAs smaller than 3 cm could be followed up safely on an annual basis with B mode ultrasound scanning. IAAs that are 3 cm or larger and smaller than 3.5 cm should be carefully followed with B mode ultrasound scanning at 6-month intervals, whereas elective repair should be considered for IAAs 3.5 cm or larger in good-risk patients. Based on this report and currently available evidence and recommendations, asymptomatic IAAs that are 4 cm or larger and all other symptomatic IAAs should be considered for operative repair. Also, the reported high rupture rate of IAAs that are 5 cm or larger mandates prompt operative repair.

Persistent sciatic artery: report of an original aneurysm-associated case.

Persistent sciatic artery (PSA) is a rare embryologic abnormality and can sometimes be bilateral. It may be discovered because of a gluteal aneurysm or ischemic or embolic complications in the lower limb. The case we report was a unilateral type III aneurysm-associated PSA. Since the abnormal artery may be the only source of blood supply to the lower limb, a thorough knowledge of the artery and its embryologic origins is essential.