Incidence and risk factors of late rupture, conversion, and death after endovascular repair of infrarenal aortic aneurysms: the EUROSTAR experience. European Collaborators on Stent/graft techniques for aortic aneurysm repair

OBJECTIVE

The EUROSTAR (European Collaborators on Stent/graft techniques for aortic aneurysm repair) Registry was established in 1996 to collect data on the outcome of treatment of patients with infrarenal aortic aneurysms with endovascular repair. To date, 88 European centers of vascular surgery have contributed. The purpose of the study was to evaluate the results of this treatment in the medium term (up to 4 years) according to the analysis of "hard" or primary end points of rupture, late conversion, and death.

PATIENTS AND METHODS

Patients with aortic aneurysms suitable for endovascular aneurysm repair were notified to the EUROSTAR Data Registry Centre before treatment to eliminate bias due to selective reporting. The following information was collected on all patients: (1) demographic details and the anatomic characteristics of their aneurysms, (2) details of the endovascular device used, (3) complications encountered during the procedure and the immediate outcome, (4) results of contrast enhanced computed tomographic imaging at 3, 6, 12, and 18 months after operation and at yearly intervals thereafter, and (5) all adverse events. Life table analysis was performed to determine the cumulative rates of (1) death from all causes, (2) rupture, and (3) late conversion to open repair. Risk factors for rupture and late conversion were identified through regression analysis.

RESULTS

By March 2000, 2464 patients had been registered, and their mean duration of follow-up was 12.19 months (SD, 12.3 months). There were 14 patients with confirmed rupture of their aneurysms. The cumulative rate (risk) of rupture was approximately 1% per year. Emergency surgery was undertaken in 12 (86%) patients, of whom five (41.6%) survived. Two patients who were not treated surgically also died, which resulted in an overall death rate of 64.5% (9/14) of the patients. Significant risk factors for rupture were proximal type I endoleak (P =.001), midgraft (type III) endoleak (P =.001), graft migration (P =.001), and postoperative kinking of the endograft (P =.001). Forty-one patients underwent late conversion to open repair with a perioperative mortality rate of 24.4% (10/41). The cumulative rate (risk) of late conversion was approximately 2.1% per year. Risk factors (indications) for late conversion were proximal type I endoleak (P =. 001), midgraft (type III) endoleak (P =.001), type II endoleak (P =. 003), graft migration (P =.001), graft kinking (P =.001), and distal type I endoleak (P =.001).

CONCLUSIONS

Endovascular repair of infrarenal aortic aneurysms with the first- and second-generation devices that predominated in this study was associated with a risk of late failure, according to an analysis of observed hard end points of 3% per year. Action taken to address the risk factors identified by the study may improve results in the future.

Limb Graft Occlusion Following EVAR: Clinical Pattern, Outcomes and Predictive Factors of Occurrence

INTRODUCTION

We reviewed our experience with limb occlusion after EVAR in order (1) to assess the clinical pattern and treatment options (2) to assess outcomes and (3) to identify predictive factors of occurrence.

MATERIALS AND METHOD

Between 1995 and 2005, 460 AAA patients were electively treated with a variety of commercially available stent grafts. There were 369 bifurcated and 91 aortouniiliac grafts (829 limbs). Follow-up included physical examination, plain X-ray, Duplex ultrasonography, and spiral computed tomographic scans at 1, 6, 12 months and annually thereafter. All pertinent data were collected prospectively and analysed retrospectively. The follow-up period ranged from Day 0 to 104 months, with a median follow-up of 23.4 months.

RESULTS

36 limbs in 33 patients (7.2%) occluded between Day 0 and 71 months (average: 9.5 months) after EVAR. Presentation was acute ischemia in 11 cases, rest pain in 9, claudication in ten. Four occlusions remained asymptomatic and two occurred intraoperatively. Treatment was femoro-femoral cross-over graft in 19 cases, axillo-femoral bypass in three, thrombectomy and stent in three, thrombolysis and stent in nine, and conservative in two. One patient (3%) died of multiple organ failure after thrombolysis. There was no amputation. Reocclusions occurred in two patients (6.1%). Multivariate logistic regression showed that kinking (odds ratio [OR] 11.9; confidence interval [CI] 3.39-42.1; p=0.0001), first graft generation (OR 2.87; CI 1.25-6.62; p=0.017) and younger age (OR 1.05; CI 1.00-1.09; p=0.034) were independently related to the occurrence of graft limb occlusion.

CONCLUSION

Acute graft limb occlusion is not rare after EVAR. The frequency of limb occlusion has declined with current stent grafts generation. Although surgery and endovascular treatments are efficient and safe, development of a graft limb kink should lead to aggressive pre-emptive treatment to prevent occlusion.

Outcomes of secondary interventions after abdominal aortic aneurysm endovascular repair

PURPOSE

We assessed the distribution of secondary interventions after aortic stent grafting (EVAR) performed to treat infrarenal abdominal aortic aneurysm (AAA), and evaluated clinical success and survival in patients who underwent a secondary procedure (group 2) compared with patients who did not undergo a secondary procedure (group 1).

METHODS

Two hundred fifty patients (mean age, 71.3 years) with asymptomatic AAAs (mean aneurysm diameter, 54.5 mm) underwent treatment with commercially available stent grafts. Mean follow-up was 28 months (median, 25 months). Secondary procedures were defined as any additional procedures performed after initial graft placement to treat endoleak, migration, kinking, stenosis, or occlusion. Overall clinical success was defined according to reporting standards of the Society for Vascular Surgery/American Association for Vascular Surgery.

RESULTS

Sixty-eight patients (27%) required 112 secondary procedures, with a mean time from initial graft placement of 18.2 months. Patients who received grafts since removed from the market required more secondary procedures (59%, procedure:patient ratio) compared with patients who received devices still on the market (21%; P =.001). Thirty-six patients (53%) required a single secondary procedure, 24 patients (35%) required two procedures, 5 patients (10%) required three procedures, 2 patients (3%) required four procedures, and 1 patient required five secondary procedures. Ninety-eight procedures (87%) were performed with endovascular methods, including placement of 42 additional covered stent grafts (36 iliac, 6 aortic), with a success rate of 85%; 35 embolization procedures (21 lumbar, 9 internal iliac artery, 5 mesenteric), with only 23 (65%) successful; 14 angioplasty procedures, with 85% successful; 4 thrombolysis procedures, 2 of them successful (50%); and 3 successfully placed new endografts within a previous endovascular graft. Surgical secondary operations included nine femorofemoral bypass procedures and three femoral thromboendarterectomies, all of which remain patent; one cerclage of an external iliac limb; and one laparoscopic repair of a type II endoleak, which was successful. Overall clinical success rate for EVAR was 84% (211 of 250) in this series. Clinical success rate in groups 1 and 2 was 91% (166 of 182) versus 66% (45 of 68; P =.001) if all endoleaks on the most recent computed tomography scans are taken into account, and 94% (171 of 182) versus 76% (52 of 68; P =.001) if type II endoleak without aneurysm growth is not considered failure. The survival rate and rupture-free survival in groups 1 and 2 were, respectively, 97.7% +/- 1.0% and 98.5% +/- 1.4% at 1 month, 95.9% +/- 1.5% and 96.9% +/- 2.1% at 6 months, 94.4% +/- 2.0% and 93.2% +/- 3.4% at 1 year, and 80.8% +/- 5.2% and 88.5% +/- 5.0% at 3 years (P =.273, log-rank test).

CONCLUSION

With close follow-up and a significant number of secondary operations, this 8-year experience has not included any aneurysm ruptures to date. Secondary operations did not lead to increased mortality, but were associated with more surgical conversions and with a higher clinical failure rate.

Risk factors and long-term outcome of transplant renal artery stenosis in adult recipients after treatment by percutaneous transluminal angioplasty

Transplant renal artery stenosis (TRAS) is a common complication of kidney transplantation but attempts to identify predisposing risk factors for TRAS have yielded conflicting results. In order to determine the predisposing factors for transplant (TRAS), we retrospectively reviewed the records of 29 renal allograft recipients with TRAS treated with percutaneous transluminal angioplasty (PTA). The TRAS group was compared with a case-control group of 58 patients. Predisposing factors for TRAS included CMV infection (41.4% vs. 12.1% p = 0.0018) and initial delayed graft function (DGF) (48.3% vs. 15.5% p = 0.0018), respectively in the TRAS and the control group. Acute rejection occurred more frequently in patients from the TRAS group (48.3%) compared with the control group (27.6%), although the difference was not significant (p = 0.06). In a multivariate analysis, only CMV infection (p = 0.005) and DGF (p = 0.009) appear to be significantly and independently associated with TRAS. The long-term graft survival was significantly higher in the control group, compared with the TRAS group (p = 0.03). Our study suggests that CMV infection and DGF are two reliable risk factors for TRAS. Despite treatment by PTA with primary successful results, TRAS significantly affects long-term graft outcome.

Image guidance for endovascular repair of complex aortic aneurysms: comparison of two-dimensional and three-dimensional angiography and image fusion

PURPOSE

To evaluate the feasibility of image fusion (IF) of preprocedural arterial-phase computed tomography with intraprocedural fluoroscopy for roadmapping in endovascular repair of complex aortic aneurysms, and to compare this approach versus current roadmapping methods (ie, two-dimensional [2D] and three-dimensional [3D] angiography).

MATERIALS AND METHODS

Thirty-seven consecutive patients with complex aortic aneurysms treated with endovascular techniques were retrospectively reviewed; these included aneurysms of digestive and/or renal arteries and pararenal and juxtarenal aortic aneurysms. All interventions were performed with the same angiographic system. According to the availability of different roadmapping software, patients were successively placed into three intraprocedural image guidance groups: (i) 2D angiography (n = 9), (ii) 3D rotational angiography (n = 14), and (iii) IF (n = 14). X-ray exposure (dose-area product [DAP]), injected contrast medium volume, and procedure time were recorded.

RESULTS

Patient characteristics were similar among groups, with no statistically significant differences (P ≥ .05). There was no statistical difference in endograft deployment success between groups (2D angiography, eight of nine patients [89%]; 3D angiography and IF, 14 of 14 patients each [100%]). The IF group showed significant reduction (P < .0001) in injected contrast medium volume versus other groups (2D, 235 mL ± 145; 3D, 225 mL ± 119; IF, 65 mL ± 28). Mean DAP values showed no significant difference between groups (2D, 1,188 Gy · cm(2) ± 1,067; 3D, 984 Gy · cm(2) ± 581; IF, 655 Gy · cm(2) ± 457; P = .18); nor did procedure times (2D, 233 min ± 123; 3D, 181 min ± 53; IF, 189 min ± 60; P = .59).

CONCLUSIONS

The use of IF-based roadmapping is a feasible technique for endovascular complex aneurysm repair associated with significant reduction of injected contrast agent volume and similar x-ray exposure and procedure time.

Overexpression of transforming growth factor-beta1 stabilizes already-formed aortic aneurysms: a first approach to induction of functional healing by endovascular gene therapy

BACKGROUND

The cell response to transforming growth factor-beta1 (TGF-beta1), a multipotent cytokine with healing potential, varies according to tissue context. We have evaluated the ability of TGF-beta1 overexpression by endovascular gene therapy to stabilize abdominal aortic aneurysms (AAAs) already injured by inflammation and proteolysis.

METHODS AND RESULTS

Active TGF-beta1 overexpression was obtained in already-developed experimental AAAs in rats after endovascular delivery of an adenoviral construct encoding for a mutated form of active simian TGF-beta1 and in an explant model using human atherosclerotic AAA fragments incubated with recombinant active TGF-beta1. Transient exogenous TGF-beta1 overexpression by endovascular gene delivery was followed by induction of endogenous rat TGF-beta1. Overexpression of active TGF-beta1 in experimental AAAs was associated with diameter stabilization, preservation of medial elastin, decreased infiltration of monocyte-macrophages and T lymphocytes, and a decrease in matrix metalloproteinase-2 and -9, which was also observed in the explant model, in both thrombus and wall. In parallel with downregulation of the destructive process, active TGF-beta1 overexpression triggered endoluminal reconstruction, replacing the thrombus by a vascular smooth muscle cell-, collagen-, and elastin-rich intima.

CONCLUSIONS

Local TGF-beta1 self-induction after transient exogenous overexpression reprograms dilated aortas altered by inflammation and proteolysis and restores their ability to withstand arterial pressure without further dilation. This first demonstration of stabilization of expanding AAAs by delivery of a single multipotent self-promoting gene supports the view that endovascular gene therapy should be considered for treatment of aneurysms.

Emergency Endovascular Repair for Ruptured Abdominal Aortic Aneurysms: Feasibility and Comparison of Early Results with Conventional Open Repair

PURPOSE

To assess the feasibility of endovascular aortic repair (EVAR) on patients presenting with a ruptured abdominal aortic aneurysm (AAA) in a teaching hospital, and to compare there post-operative outcomes with contemporaneous patients treated with open repair (OR).

METHODS

A series of consecutive of patients presenting ruptured AAA with retro/intraperitoneal haematoma were included in the study. EVAR was attempted whenever possible. In all other cases (severe haemodynamic instability, adverse anatomy, device unavailability), ruptured AAA were treated by OR.

RESULTS

Thirty-seven patients were enrolled between January 2001 and July 2004. Seventeen (46%) patients were treated using adapted designed aortoiliac endografts (eight bifurcated, eight aorto-uniiliac, one iliac extension). Twenty (54%) patients unfit for EVAR because of severe haemodynamic instability (n=8), adverse anatomical configuration (n=7), or unavailability of an appropriate endograft (n=5) were treated by OR. Twenty-seven (73%) had a retrospective suitable anatomy for EVAR. Three early conversions from EVAR to OR were performed. Blood loss, operating time, and intensive care stay were significantly decreased in EVAR patients (respectively: 156 min+/-60, 1520 ml+/-1175, 3 days for EVAR; vs. 222 min+/-82, 3075 ml+/-1750, 13 days for OS; P<.01). The 30-day mortality rate was 23.5% for EVAR vs. 50% for OR (P=0.09).

CONCLUSION

EVAR of ruptured AAA is feasible for selected patients based on haemodynamic and morphologic criteria, and should be associated with improved immediate outcomes as compared with OR. These results should be tempered by the fact that these patients have heavy comorbidities which explains the absence of difference in mid-term mortality rates between the two groups, but should also encourage surgical institutions that are managing such life-threatening emergencies to introduce EVAR as part of their therapeutic arsenal for ruptured AAA.

Follow-up evaluation of endoluminally treated abdominal aortic aneurysms with duplex ultrasonography: validation with computed tomography

OBJECTIVE

A growing number of patients with abdominal aortic aneurysms are currently being offered endoluminal treatment. However, the incidence of endoleaks, stenosis, and thrombosis is around 25% to 30%. As a result, a strict post procedure imaging surveillance protocol is necessary. The purpose of this study was to compare duplex ultrasonography (DU) and computed tomography (CT) for the follow-up of endoluminally treated aortic aneurysms.

METHODS

A total of 89 patients were followed up with serial CT and DU at 1, 3, 6, 12, and 24 months after endoluminal treatment. Special attention was directed toward the presence of endoleaks and aneurysm diameter evolution. Preoperative CT and DU were also reviewed to assess aneurysm diameter correlation.

RESULTS

With DU, 14 type I and 21 type II endoleaks were identified. In one case the DU did not visualize a type II endoleak present on CT, and CT did not confirm three type II leaks identified with DU. There was only one false positive for type I endoleak with DU. The sensitivity of DU was 96% with a specificity of 94%, when compared with CT. A linear regression analysis of the diameters obtained with DU and CT revealed a good correlation. However, variability was high, indicating poor agreement. Regarding diameter evolution, the range was identical in 45%, and the trend was similar in 73%. However, in 9% of the cases, DU showed a decrease in diameter, whereas CT showed a significant increase.

CONCLUSION

DU is an accurate tool for the diagnosis of endoleaks, but is less valuable for diameter measurements, when compared with CT. Currently, DU is a useful tool, but CT remains a key part of the postoperative evaluation after endoluminal treatment of abdominal aortic aneurysms. At institutions where DU is used for follow-up, researchers should perform quality control studies to avoid potentially significant errors.

Paracrine effect of vascular smooth muscle cells in the prevention of aortic aneurysm formation

OBJECTIVE

Inflammation and elastinolysis are observed in the media of abdominal aortic aneurysms (AAAs) where vascular smooth muscle cell (VSMC) density is decreased. In contrast, elastin and VSMCs are preserved in the noninflammatory media of stenotic atherosclerotic lesions. We have tested the hypothesis that VSMCs exert a protective effect against inflammation and proteolysis in a model of AAA in rats, in which medial elastin degradation is driven by inflammation and matrix metalloproteinases.

METHOD

Decellularized guinea pig aortas (xenografts) were implanted orthotopically into Fischer-344 rats and seeded with a suspension of rat VSMCs syngeneic to the rat recipient, or were infused with culture medium as a control. Diameter and elastin in the media were quantified 8 weeks after implantation. Inflammation, matrix metalloproteinase (MMP) and tissue inhibitor of matrix metalloproteinase (TIMP) expression were analyzed 1 and 2 weeks after implantation.

RESULTS

VSMC addition prevented AAA formation (mean +/- standard deviation diameter increase: 198.2% +/- 106.6% vs 35.3% +/- 17.8%, P =.009), elastin degradation, and decreased infiltration by monocyte-macrophages. Reverse-transcriptase polymerase chain reaction, zymography and reverse zymography for MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 demonstrated a shift of the proteolytic-antiproteolytic balance upon addition of VSMCs. Transcriptional changes were observed in the adventitia, although seeded VSMCs remained located in the intima.

CONCLUSIONS

VSMCs exert a paracrine effect on the adventitia that participate in artery wall homeostasis against inflammation and proteolysis. Failure of this protective mechanism results in AAA formation. The understanding of the molecular mechanisms underlying VSMC protective effect may represent a new approach in the treatment of aneurysm and plaque rupture.

Mitogenic and in vitro angiogenic activity of human recombinant heparin affin regulatory peptide

We have previously described the purification of a heparin binding growth factor from adult bovine brain named heparin affin regulatory peptide (HARP), which was identical to an uterus derived growth factor named pleiotrophin and to a developmentally regulated neurite promoting factor named heparin-binding growth associated molecule. However, for yet unclear reasons, the mitogenic activity of this purified polypeptide following isolation from animal tissue extracts is a subject of controversy, due to conflicting and irreproducible data when produced by recombinant DNA technologies in E. coli or insect cells. The purified protein was inactive in mitogenic assays but the natural molecule was active in assay of neurite outgrowth. In order to clarify these conflicting results and to obtain a recombinant protein free from other contaminating heparin-binding growth factors, we have cloned human cDNA encoding human HARP, engineered its expression in NIH 3T3 cells and characterised the resulting recombinant polypeptide. Purified recombinant HARP displayed mitogenic activity for capillary endothelial cells with half-maximal stimulation at approximately 1 ng/ml (55 pM) and induced angiogenesis in an in vitro model. Interestingly, while the NH2 terminal sequence of tissue purified HARP was NH2-GKKEKPEKK, the NH2 terminal sequence of the biologically active recombinant protein was NH2-AEAGKKEKPEKK, corresponding to a three amino acid extended form.

The impact of aortic endografts on renal function

OBJECTIVE

To determine the impact on late postoperative renal function of suprarenal and infrarenal fixation of endografts used to treat infrarenal abdominal aortic aneurysm (AAA).

METHODS

Retrospective analysis of 277 patients treated from 2000 to 2003 with three different endografts at two clinical centers. Five patients on dialysis for preoperative chronic renal failure were excluded. Group IF of 135 patients treated with an infrarenal device (Medtronic AneuRx) was compared with group SF of 137 patients treated with a suprarenal device (106 Cook Zenith and 31 Medtronic Talent). Renal function was evaluated by calculating preoperative and latest postoperative creatinine clearance (CrCl) using the Cockcroft formula. Patients who developed a >20% decrease in CrCl were considered to have significantly impaired renal function.

RESULTS

There were no significant differences in patient age, sex, aneurysm size, preoperative risk factors, dose of intra- and postoperative contrast, or baseline CrCl (IF: 69.3 mL/min, SF: 71.7 mL/min, P = .4). Follow-up time of 12.2 months was the same in both groups. CrCl decreased significantly during the follow-up period in both groups (IF: 69.3 mL/min to 61.7 mL/min, P < .01; SF: 71.7 mL/min to 64.9 mL/min, P < .03). Postoperative CrCl (IF: 61.7 mL/min, SF: 64.9 mL/min, P = .3), and the rate of CrCl decrease during the follow-up period (IF: -10.9%, SF: -9.5%, P = .2) was not different between the two groups. The number of patients with a >20% decrease in CrCl was not different between the two groups (IF: n = 35 [25.9%], SF: n = 41 [29.9%], P = .46). However, the magnitude of decrease in CrCl in patients with renal impairment was greater in patients treated with suprarenal fixation endografts (SF: -39%) compared with those treated with infrarenal endografts (IF: -31%, P = .005). This greater degree of renal impairment was not due to identifiable differences in preoperative risk factors, age, or baseline CrCl. No patients in these series required dialysis.

CONCLUSIONS

Regardless the type of endograft used, there is a 10% decrease in CrCl in the first year after endovascular aneurysm repair. Suprarenal fixation does not seem to increase the likelihood of postoperative renal impairment. Decline in renal function over time after endovascular aortic repair is probably due to multiple factors, and measures known to be effective in protecting kidneys should be considered for these patients. Long-term follow-up with measurement of CrCl, along with renal imaging and regular blood pressure measurements, should be performed to detect possible late renal dysfunction. Prospective studies comparing suprarenal versus infrarenal fixation are needed to confirm those results.

Mid-term results of endovascular versus open repair for abdominal aortic aneurysm in patients anatomically suitable for endovascular repair

OBJECTIVES

to prospectively evaluate the mid-term results of endovascular and open repair in patients with abdominal aortic aneurysm (AAA) anatomically suitable for endovascular repair.

MATERIAL AND METHODS

between January 1995 and March 1999, among 438 patients treated for AAA, 180 (41%) were suitable for endovascular repair as assessed by computed tomography (CT) scan and angiogram. Seventy-three were treated by various commercially available endovascular grafts (EV) and 107 by open repair (OR). Postoperatively, patients were followed every 6 months with clinical examination, duplex scan and in the EV group, CT scans. Patients>> demographic data, intra- and postoperative events were recorded prospectively in a computerised database and compared for each group.

RESULTS

median age, sex ratio, preoperative risk factors and aneurysm diameters were not statistically different between the two groups. Respectively in the EV and OR, the average duration of operation was 149+/-73 mn, and 133+/-44 mn (NS), blood loss 96 ml+/-28 and 985 ml+/-113 (p<0.01), duration of hospitalisation 7 days+/-2 and 13 days+/-7 (p<0.01). The one-month mortality was 2.7% (n=2) for EV and 2.8% (n=3) for OR. The rate of cardiac and pulmonary complications was significantly higher in the OR group (6. 9% versus 19.6%, p=0.017). At a mean follow-up of 1 year, the cumulative survival rate was 82.2%+/-7.5 for EV and 96%+/-2.12 for OR (log-rank test p=0.043). No patients died of rupture, but three patients had to be converted to open surgery. Twenty-two percent (n=16) patients in the EV and 7.5% (n=8) in the OR were submitted to a subsequent minor or major reintervention (p=0.007). At 1 year, the cumulative rates free of any reintervention were respectively 78. 8%+/-6.7% and 92.9%+/-2.7% (p=0.001). In the EV there were 17 early endoleaks (23.3%). At the end of patient's follow-up seven endoleaks (9.6%) persisted. The primary success rate defined by the absence of endoleak and the absence of reintervention was 54 (74%) with EV and 101 (94%) with OR (p=0.001).

CONCLUSION

EV is a promising technique. However, with current devices and indications the immediate benefits, mainly less blood loss, fewer cardiac and pulmonary complications, and shorter hospitalisation time, are outweighed by a higher rate of reinterventions to treat endoleak, or to maintain patency of the graft.

Individual-patient meta-analysis of three randomized trials comparing endovascular versus open repair for ruptured abdominal aortic aneurysm

BACKGROUND

The benefits of endovascular repair of ruptured abdominal aortic aneurysm remain controversial, without any strong evidence about advantages in specific subgroups.

METHODS

An individual-patient data meta-analysis of three recent randomized trials of endovascular versus open repair of abdominal aortic aneurysm was conducted according to a prespecified analysis plan, reporting on results to 90 days after the index event.

RESULTS

The trials included a total of 836 patients. The mortality rate across the three trials was 31.3 per cent for patients randomized to endovascular repair/strategy and 34.0 per cent for those randomized to open repair at 30 days (pooled odds ratio 0.88, 95 per cent c.i. 0.66 to 1.18), and 34.3 and 38.0 per cent respectively at 90 days (pooled odds ratio 0.85, 0.64 to 1.13). There was no evidence of significant heterogeneity in the odds ratios between trials. Mean(s.d.) aneurysm diameter was 8.2(1.9) cm and the overall in-hospital mortality rate was 34.8 per cent. There was no significant effect modification with age or Hardman index, but there was indication of an early benefit from an endovascular strategy for women. Discharge from the primary hospital was faster after endovascular repair (hazard ratio 1.24, 95 per cent c.i. 1.04 to 1.47). For open repair, 30-day mortality diminished with increasing aneurysm neck length (adjusted odds ratio 0.69 (95 per cent c.i. 0.53 to 0.89) per 15 mm), but aortic diameter was not associated with mortality for either type of repair.

CONCLUSION

Survival to 90 days following an endovascular or open repair strategy is similar for all patients and for the restricted population anatomically suitable for endovascular repair. Women may benefit more from an endovascular strategy than men and patients are, on average, discharged sooner after endovascular repair.

A propensity-matched comparison of outcomes for fenestrated endovascular aneurysm repair and open surgical repair of complex abdominal aortic aneurysms

OBJECTIVE

The benefit of fenestrated endovascular aortic aneurysm repair (FEVAR) compared with open surgical repair (OSR) of complex abdominal aortic aneurysms (CAAAs) is unknown. This study compares 30-day outcomes of these procedures from two high-volume centers where FEVAR was undertaken for high-risk patients.

METHODS

Patients undergoing FEVAR with commercially available devices and OSR of CAAAs (total suprarenal/supravisceral clamp position) were propensity matched by demographic, clinical, and anatomic criteria to identify similar patient cohorts. Perioperative outcomes were evaluated using univariate and multivariate methods.

RESULTS

From July 2001 to August 2012, 59 FEVAR and 324 OSR patients were identified. After 1:4 propensity matching for age, gender, hypertension, congestive heart failure, coronary disease, chronic obstructive pulmonary disease, stroke, diabetes, preoperative creatinine, and anticipated/actual aortic clamp site, the study cohort consisted of 42 FEVARs and 147 OSRs. The most frequent FEVAR construct was two renal fenestrations, with or without a single mesenteric scallop, in 50% of cases. An average of 2.9 vessels were treated per patient. Univariate analysis demonstrated FEVAR had higher rates of 30-day mortality (9.5% vs. 2%; P = .05), any complication (41% vs. 23%; P = .01), procedural complications (24% vs. 7%; P < .01), and graft complications (30% vs. 2%; P < .01). Multivariable analysis showed FEVAR was associated with an increased risk of 30-day mortality (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.1-24; P = .04), any complication (OR, 2.3; 95% CI, 1.1-4.9; P = .01), and graft complications (OR, 24; 95% CI, 4.8-66; P < .01).

CONCLUSIONS

FEVAR, in this two-center study, was associated with a significantly higher risk of perioperative mortality and morbidity compared with OSR for management of CAAAs. These data suggest that extension of the paradigm shift comparing EVAR with OSR for routine AAAs to patients with CAAAs is not appropriate. Further study to establish proper patient selection for FEVAR instead of OSR is warranted before widespread use should be considered.

A substituted dextran enhances muscle fiber survival and regeneration in ischemic and denervated rat EDL muscle

Ischemia and denervation of EDL muscle of adult rat induce a large central zone of degeneration surrounded by a thin zone of peripheral surviving muscle fibers. Muscle regeneration is a complex phenomenon in which many agents interact, such as growth factors and heparan sulfate components of the extracellular matrix. We have shown that synthetic polymers, called RGTA (as regenerating agents), which imitate the heparan sulfates, are able to stimulate tissue repair when applied at the site of injury. In crushed muscles, RGTA were found to accelerate both regeneration and reinnervation. In vitro, RGTA act as protectors and potentiators of various heparin binding growth factors (HBGF). It was postulated that in vivo their tissue repair properties were due in part to an increase of bioavailability of endogenously released HBGF. In the present work, we show that ischemic and denervated EDL muscle treated by a unique injection of RGTA differs from the control after 1 wk in several aspects: 1) the epimysial postinflammatory reaction is inhibited and the area of fibrotic tissue among fibers is reduced; 2) the peripheral zone, as measured by the number of intact muscle fibers, was increased by more than twofold; and 3) In the central zone, RGTA enhances the regeneration of the muscle fibers as well as muscle revascularization. These results suggest that RGTA both protects muscle fibers from degeneration and preserves the differentiated state of the surviving fibers. For the first time it is demonstrated that a functionalized polymeric compound can prevent some of the damage resulting from muscle ischemia. RGTA may therefore open a new therapeutic approach for muscle fibrosis and other postischemic muscle pathologies.

Assessment of critical limb ischemia in patients with diabetes: comparison of MR angiography and digital subtraction angiography

OBJECTIVE

The purpose of our study was to evaluate the diagnostic accuracy of hybrid MR angiography by comparison with digital subtraction angiography (DSA) in diabetic patients with critical limb ischemia.

SUBJECTS AND METHODS

Thirty-one patients prospectively underwent both hybrid MR angiography and DSA. The hybrid MR angiography study consisted of high-resolution MR angiography of a single calf and foot using a contrast-enhanced 3D gradient-echo volumetric interpolated breath-hold examination with surface coils, followed by three-station bolus chase MR angiography with a dedicated peripheral vascular coil. Two blinded reviewers separately analyzed maximum-intensity-projection hybrid MR angiograms and DSA images. The peripheral vessels were divided into 10 anatomic segments for review. The status of each segment was graded as normal, stenosis less than 50% in diameter, stenosis greater than 50%, or occluded. The sensitivity and specificity of hybrid MR angiography were determined using DSA as the gold standard. Treatment options were considered separately from the results of each examination.

RESULTS

Among 310 analyzed segments, the sensitivities of hybrid MR angiography for stenosis and occlusion were, respectively, 95% and 95% for reviewer 1 and 96% and 90% for reviewer 2. The specificities of hybrid MR angiography for stenosis and occlusion were, respectively, 98% and 98% for reviewer 1 and 98% and 99% for reviewer 2. In 25 patients (81%), the quality of bolus chase MR angiography images was insufficient to assess runoff arteries. All treatments proposed on the basis of DSA findings were endorsed by hybrid MR angiography findings. Eleven more treatments were formulated on the basis of hybrid MR angiography findings. Of these, four were due to overestimation of stenosis on MR angiography and seven were due to the detection of patent infrageniculate arteries on hybrid MR angiography that were not detected on DSA.

CONCLUSION

Hybrid MR angiography depicts runoff arteries not seen on DSA. Hybrid MR angiography may be useful for treatment planning in selected diabetic patients with critical limb ischemia.

Efficacy of a Drug-Eluting Stent Versus Bare Metal Stents for Symptomatic Femoropopliteal Peripheral Artery Disease: Primary Results of the EMINENT Randomized Trial

BACKGROUND

A clear patency benefit of a drug-eluting stent (DES) over bare metal stents (BMSs) for treating peripheral artery disease of the femoropopliteal segment has not been definitively demonstrated. The EMINENT study (Trial Comparing Eluvia Versus Bare Metal Stent in Treatment of Superficial Femoral and/or Proximal Popliteal Artery) was designed to evaluate the patency of the Eluvia DES (Boston Scientific, Marlborough, MA), a polymer-coated paclitaxel-eluting stent, compared with BMSs for the treatment of femoropopliteal artery lesions.

METHODS

EMINENT is a prospective, randomized, controlled, multicenter European study with blinded participants and outcome assessment. Patients with symptomatic peripheral artery disease (Rutherford category 2, 3, or 4) of the native superficial femoral artery or proximal popliteal artery with stenosis ≥70%, vessel diameter of 4 to 6 mm, and total lesion length of 30 to 210 mm were randomly assigned 2:1 to treatment with DES or BMS. The primary effectiveness outcome was primary patency at 12 months, defined as independent core laboratory-assessed duplex ultrasound peak systolic velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion. Primary sustained clinical improvement was a secondary outcome defined as a decrease in Rutherford classification of ≥1 categories compared with baseline without a repeat target lesion revascularization. Health-related quality of life and walking function were assessed.

RESULTS

A total of 775 patients were randomly assigned to treatment with DES (n=508) or commercially available BMSs (n=267). Baseline clinical, demographic, and lesion characteristics were similar between the study groups. Mean lesion length was 75.6±50.3 and 72.2±47.0 mm in the DES and BMS groups, respectively. The 12-month incidence of primary patency for DES treatment (83.2% [337 of 405]) was significantly greater than for BMS (74.3% [165 of 222]; P<0.01). Incidence of primary sustained clinical improvement was greater among patients treated with the DES than among those who received a BMS (83.0% versus 76.6%; P=0.045). The health-related quality of life dimensions of mobility and pain/discomfort improved for the majority of patients in both groups (for 66.4% and 53.6% of DES-treated and for 64.2% and 58.1% of BMS-treated patients, respectively) but did not differ significantly. At 12 months, no statistical difference was observed in all-cause mortality between patients treated with the DES or BMS (2.7% [13 of 474] versus 1.1% [3 of 263]; relative risk, 2.4 [95% CI, 0.69-8.36]; P=0.15).

CONCLUSIONS

By demonstrating superior 1-year primary patency, the results of the EMINENT randomized study support the benefit of using a polymer-based paclitaxel-eluting stent as a first-line stent-based intervention for patients with symptomatic peripheral artery disease attributable to femoropopliteal lesions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02921230.

RGTA® or ReGeneraTing Agents mimic heparan sulfate in regenerative medicine: from concept to curing patients

The importance of extracellular matrix (ECM) integrity in maintaining normal tissue function is highlighted by numerous pathologies and situations of acute and chronic injury associated with dysregulation or destruction of ECM components. Heparan sulfate (HS) is a key component of the ECM, where it fulfils important functions associated with tissue homeostasis. Its degradation following tissue injury disrupts this delicate equilibrium and may impair the wound healing process. ReGeneraTing Agents (RGTA^®s) are polysaccharides specifically designed to replace degraded HS in injured tissues. The unique properties of RGTA^® (resistance to degradation, binding and protection of ECM structural and signaling proteins, like HS) permit the reconstruction of the ECM, restoring both structural and biochemical functions to this essential substrate, and facilitating the processes of tissue repair and regeneration. Here, we review 25 years of research surrounding this HS mimic, supporting the mode of action, pre-clinical studies and therapeutic efficacy of RGTA^® in the clinic, and discuss the potential of RGTA^® in new branches of regenerative medicine.

New bacteriological patterns in primary infected aorto-iliac aneurysms: a single-centre experience

OBJECTIVES

To assess causative pathogens and surgical outcomes in patients with primary infected aorto-iliac aneurysms at our institution.

DESIGN

Retrospective study of patients treated at a university hospital between 1992 and 2009.

RESULTS

We identified 26 patients (median age, 63 years) with primary infected aneurysms on the aorta (descending thoracic, n = 2; thoraco-abdominal, n = 3; suprarenal, n = 2; infrarenal, n = 15) or iliac arteries (n = 4). Among them, 22 were symptomatic, including 13 with ruptured aneurysms. The causative organisms, identified in 25/26 patients, were Campylobacter fetus, n = 6; Streptococcus pneumoniae, n = 4; Listeria, n = 3; Salmonella, n = 2; Mycobacterium tuberculosis, n = 2; Staphylococcus aureus, n = 1; and other, n = 7. Immune suppression was a feature in 10 (38.4%) patients. Revascularisation was performed in situ in 23 patients (10 allografts, eight grafts, three superficial femoral veins, and 2 stentgrafts) and by extra-anatomic bypass in three patients. Hospital mortality was 23% (in situ group, 17.4%; extra-anatomic group, 66.7%; χ(2)(Yates), P = 0.24). During follow-up in the 20 survivors (median, 48.5 months), there were two non-infection-related deaths (five and 24 months) and six (30%) vascular complications.

CONCLUSIONS

The bacteriological spectrum of primary infected aorto-iliac aneurysms was wider than previously reported. The availability of new diagnostic tests and increased prevalence of immunosuppression may explain this finding.