Persistent Endoleak Research Articles

Aortic arch debranching and thoracic endovascular repair

Currently, the best approach to the aortic arch remains unsupported by robust evidence. Most of the available data rely on small sample numbers, heterogeneous settings, and limited follow-up. The objective of this study was to evaluate early and midterm results of arch debranching and endovascular procedures. From 2005 through 2013, 104 consecutive patients underwent elective arch treatment with debranching and thoracic endovascular aortic repair. Rates of perioperative (30-day) mortality and neurological complications, and mortality, endoleak, supra-aortic vessel patency, and arch diameter changes at 5 years were analyzed. Patients' mean age was 69.8 years, and 90 were males. Twenty arches were repaired for dissection. Nineteen patients required total debranching for diseases extended to zone 0. In 59, debranching and thoracic endovascular aortic repair procedures were staged. At 30 days, death, stroke, and spinal cord ischemia occurred in six, four, and three patients, respectively. Extension to ascending aorta (zone 0 landing) was the only multivariate independent predictor for perioperative mortality (odds ratio, 9.6; 95% confidence interval, 1.54-59.90; P = .015), but not for stroke. Four retrograde dissections, two fatal, occurred during the perioperative period. At 1, 3, and 5 years, Kaplan-Meier survival rates were 89.0%, 82.8%, and 70.9%, and freedom from persistent endoleak rates were 96.1%, 92.5%, and 88.3%, respectively. Over 5-year follow-up, 34 aneurysms shrank ≥ 5 mm, and four grew. Five reinterventions were required. Two supra-aortic vessel occlusions and no late aorta-related mortalities were recorded. Despite the perioperative mortality risk, the late outcome of endovascular arch repair presents a low rate of aorta-related deaths and reinterventions and acceptable midterm survival. Furthermore, more than one-third of the aneurysms' diameters decrease over 5 years as a measure of the long-term efficacy of treatment. Retrograde type A dissection remains a major concern in the perioperative period and careful arch approach is required.

Clinical significance of endoleaks characterized by computed tomography during aortography performed immediately after endovascular abdominal aortic aneurysm repair: prediction of persistent endoleak

This study aimed to predict the persistence of endoleaks (ELs) using patterns and volumes evaluated by computed tomography during aortography (CTDA) performed immediately after endovascular abdominal aortic aneurysm repair (EVAR). CTDA immediately after EVAR and at the 6-month follow-up CT were performed in 52 patients. ELs were classified as localized-type pattern (LTP; <180° around the center of the aneurysmal lumen) or circumferential-type pattern (CTP; >180°). The proportion of EL volume in the aneurysmal sac, excluding mural thrombus, was classified as grade A (≤5 %), B (5-10 %), or C (≥10 %). The 6-month follow-up residual rates were evaluated, and volume ratios (follow-up CT aneurysmal volume including mural thrombus/CTDA aneurysmal volume) were calculated. The residual rate (5.3 %) and mean volume ratio (83.9 %) of ELs with LTP were significantly lower than those of ELs with CTP (72.2 and 99.3 %, respectively); there was no significant difference in residual rate or mean volume ratio among EL grades (A: 17.6, 88.1 %; B: 55.6, 89.7 %; C: 54.5, 97.8 %). ELs with LTP generally disappear over time after EVAR, with a concomitant reduction in aneurysm volume, whereas those with CTP persist, indicating that patients with EL with a CTP should be followed up carefully.

A new injectable radiopaque chitosan-based sclerosing embolizing hydrogel for endovascular therapies

Endovascular repair of abdominal aortic aneurysms with a stent graft is limited by the persistence or recurrence of endoleaks. These are believed to be related to the recanalization of the aneurismal sac by endothelialized neochannels, which could lead to late type I and II endoleaks. Embolization has been proposed to treat or prevent endoleaks, but presently commercialized embolizing materials have several drawbacks and do not fully prevent endoleak recurrence. A novel chitosan hydrogel that is injectable, radiopaque and contains sodium tetradecyl sulfate (STS), a well-known sclerosing agent, was developed in order to combine blood flow occlusion and endothelium ablation properties. chitosan/STS hydrogels were characterized and optimized using rheometry, scanning electron microscopy, swelling and ex vivo embolization assay. They were shown to exhibit rapid gelation and good mechanical properties, as well as sclerosing properties. Their potential for the embolization of aneurysms was subjected to preliminary in vivo evaluation in a bilateral iliac aneurysm model (three dogs) reproducing persistent endoleaks after endovascular aneurysm repair (EVAR). At 3months no endoleak was detected in any of the three aneurysms treated with chitosan/STS hydrogels. In contrast, type I endoleaks were detected in two of the three aneurysms treated with chitosan hydrogels. Generally, chitosan/STS hydrogels have great potential as embolizing and sclerosing agents for EVAR and possibly other endovascular therapies.

Type II Endoleaks After Endovascular Repair of Abdominal Aortic Aneurysms:Fate of the Aneurysm Sac and Neck Changes During Long-term Follow-up

To evaluate the frequency of type II endoleaks after endovascular aneurysm repair (EVAR) and to compare sac diameter and neck changes in patients with type II endoleak to endoleak-free patients with at least 3-year imaging follow-up. Among 407 consecutive EVAR patients, 109 patients (101 men; mean age 72.1 years, range 55-86) had at least 3-year computed tomography (CT) data and no type I or III endoleak. In this cohort, 49 patients presented with a type II endoleak at some time and 60 patients had no endoleak. Patients with type II endoleaks were further divided into subgroups based on the vessel origin and the perfusion status (persistent or transient). The course of the perfusion status of type II endoleaks and changes in the aneurysm sac diameters, neck diameters, and renal to stent-graft distances (RSD) were evaluated in the defined groups. Reintervention and death rates were also reported. The mean follow-up was 68.1 ± 23.8 months. Compared to the no endoleak group, overall sac diameter increased significantly in the type II endoleak group (p = 0.007), but vessel origin did not have any influence. With regard to the perfusion status of type II endoleaks, aneurysm sac changes were significantly higher (p = 0.002) in the persistent endoleak group. During the study period, the increase in the proximal neck diameter was significantly higher in the no endoleak group compared to the type II endoleak group (p = 0.025). No significant difference was found in RSD changes between the defined groups. Reinterventions were performed in 20 (18.3%) patients (13 for type II endoleak); 2 (1.8%) patients without type II endoleak died of ruptured aneurysm. Persistent type II endoleaks led to significant aneurysm sac enlargement, but without increased mortality or rupture rates.

Commentary: Late Aortic Rupture:The Achilles' Heel of Endovascular Abdominal Aortic Aneurysm Repair

Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) was introduced 20 years ago as a minimally invasive prophylactic procedure to prevent aneurysm rupture. However, rupture after EVAR has been reported and is associated with a high mortality. Rupture after successful EVAR is usually preceded by endograft-related complications, such as type I endoleak and stentgraft migration detected by optimal imaging surveillance. In this issue of JEVT, Venermo et al. attempt to calculate the risk of AAA rupture after EVAR with persistent type Ia endoleak compared to the risk in a cohort of patients with untreated AAA of a similar size. The conventional wisdom is that type I endoleak increases aneurysm rupture risk after EVAR equal to that of a non-operated AAA and therefore needs endovascular reintervention or open conversion. Therefore, the findings that the rupture rate and aneurysm-related death are lower in patients with type I endoleaks compared to the untreated AAA group are interesting and challenge the commonly held notion that type I endoleak following EVAR is evidence of inadequate treatment. This observation suggests that EVAR is beneficial to the patient even if the deployment is not technically successful, which may be of importance in the high-risk patient with multiple comorbidities, a large AAA, and anatomy hostile to stent-graft repair. The authors report that the aneurysmrelated mortality was significantly reduced in the endoleak group compared to the untreated AAA cohort at all time points up to 3 years. The surveillance imaging protocol was good in that the investigators used both duplex ultrasound and contrast-enhanced computed tomography at each follow-up interval with independent classification of endoleak type by both a radiologist and vascular surgeon, although no misclassification rate is given. The length of follow-up is, however, relatively short; ruptures occur at all times during follow-up, with the mean interval from EVAR to rupture recently reported at 4.8 years. The importance of long-term 10year follow-up has been recently highlighted, and the patients in this study require further surveillance before we can draw robust conclusions. As the authors acknowledge, the potential mechanism of protection from rupture despite a persistent type I endoleak is unknown. It may involve prevention or limitation of AAA enlargement by endograft placement. Good stent position, despite an imperfect sealing zone, may allow only a small amount of blood to flow into an already depressurized aneurysm sac, limiting AAA enlargement. The cohort from this study was a ‘‘controlled’’ group of endoleak patients, whereby prompt secondary endovascular intervention was undertaken to try and seal proximal sites that gave rise to type Ia endoleaks. Hence, the

Reprinted Article “Realistic Expectations for Patients with Stent-graft Treatment of Abdominal Aortic Aneurysms. Results of a European Multicentre Registry”

Objective The outcomes for patients after endovascular treatment of abdominal aortic aneurysm (AAA) are determined primarily by the endpoints of death and endoleaks, the latter representing continued risk of rupture. The data of a multicentre registry were analysed with regard to the early outcome of stent-graft procedures for AAA and the complications associated with this treatment. In addition, the results during follow-up were analysed by determining mortality and endoleak development as separate endpoints and as a combined endpoint defined as endoleak-free survival. Setting 38 European institutions of Vascular Surgery collaborating in a multicentre registry project. Patients and methods 899 patients with AAA underwent between May 1994 and March 1998 elective endovascular repair (818 men and 81 women; mean age 69 years). 80 (8.9%) of the patients had medical conditions that excluded them from open repair. 818 (91%) of patients had a bifurcated device, 63 (7%) had a straight tube graft, and only 18 (2%) had an aorto-uni-iliac device. Clinical examination and contrast-enhanced computed tomography was performed at fixed follow-up intervals to assess increase or decrease of the maximum transverse diameter (MTD). Endoleaks observed at follow-up were discriminated into persistent endoleak and temporary endoleak. The latter is defined as single time observed endoleaks or with two or more negative imaging studies between observed endoleaks. Life-table analyses were used to calculate the rates of freedom-from-endoleak (no endoleak at any time), freedom-from-persistent endoleak (no persistent endoleak), patient survival, and persistent-endoleak-free-survival. Results The median follow-up of this patient series was 6.2 months. The ratio between observed and expected follow-up data was 82% for the overall follow-up period. However, at 18 months of follow-up this rate was only 45%. The number of patients followed during this period was sufficient to allow statistically meaningful assessment. The MTD in patients with temporary endoleaks demonstrated a significant decrease at 6 to 12 months compared to preoperative values (mean 57 and 53 respectively, p = 0.004). In patients with persistent endoleaks there was no change between the preoperative and 6-month MTD (mean 57 and 60 mm respectively). At 6 and 18 months freedom-from-endoleak was 83% and 74% and freedom-from-persistent endoleak was 93% and 90%, respectively. The 18-month cumulative patient survival was 88% and the main outcome measure, the persistent endoleak-free-survival was 79%. Conclusions The MTD decreases in patients with temporary endoleak, but not in patients with persistent endoleak. Therefore, the use of the rate of freedom-from-persistent endoleak, reflecting absence of persisting endoleaks to estimate the prognosis with regard to the AAA, is justified. Determining persistent endoleak-free survival appears a rational approach to provide a realistic outlook for patients with stent-grafted AAA. The observed 18-month endoleak-free survival reflects a satisfactory mid-term result.

Thoracic endovascular aortic repair with homemade stent grafts: Early and mid-term outcomes

We reviewed our experience with homemade stent grafts in the repair of a variety of thoracic aortic lesions. The objective of this study was to assess the early and mid-term outcomes of this therapy. From 1999 to 2007, homemade stent grafts were inserted in 88 patients with an atherosclerotic aneurysm, dissection, pseudoaneurysm, trauma, or rupture in the thoracic aorta. The endoprostheses were stainless steel Z-stents covered by a polyester graft, and were custom-designed for each patient. Placement of stent grafts was technically successful in 81 of the 88 patients (92%). Within 30 days after treatment, 3 patients died, 3 had a cerebral infarction, and 3 had onset of paraplegia or paraparesis. Primary endoleaks were observed in 8 patients (9%). During the mean follow-up period of 32 ± 26 months, 7 patients had persistent endoleaks and 7 had stent-graft migration. The aneurysm-related mortality rate was 7%. The rate of freedom from open-surgery conversion at 32 months was 89.0%. Our early experience with elective and emergency thoracic endovascular aortic repair using homemade stent grafts provided therapeutic benefits to high-risk patients. Endoleaks and stent-graft migrations were the factors most commonly responsible for secondary intervention in the mid-term period. Careful follow-up of patients treated with this approach is needed to avoid major complications in the long term.

Emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset in 30 cases

To investigate the results of emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset. A retrospective analysis of the clinical data of 30 patients with complicated Stanford type B aortic dissections who underwent emergency endovascular repair between June 2007 and October 2008. Endovascular repairs were performed within 24 hours of symptom onset. Stent-grafts were deployed at the first entry tear through the femoral artery under fluoroscopic guidance. Follow-up computed tomography scans were performed at 1, 3, 6, 12, and 18 months after treatment. The mean patient age was 64 years (range, 43-83 years). There were 3 cases associated with rupture, 6 cases associated with refractory hypertension, 15 cases associated with persistent pain, 2 cases associated with retrograde dissection, and 4 cases associated with malperfusion. The technical success rate was 100%, and the incidence of immediate postoperative endoleaks was 13.4%. One patient died of dissection rupture within 30 days. The mean follow-up period was 12 ± 8 months. A small, persistent endoleak (<10%) occurred in 1 patient, and 1 patient died of acute liver failure 2 months after the operation. No stent dislocation, false lumen expansion, or paraplegia occurred. The false lumen was completely thrombosed in 6 patients and partially thrombosed in 19 patients. The mortality rate was 6.67%. Our results suggest that emergency endovascular repair of complicated Stanford type B aortic dissections within 24 hours of symptom onset is associated with good outcomes and can decrease mortality.

RR31. Peak Perioperative Troponin I Levels With The Revised Cardiac Risk Index Predict Outcomes Following Vascular Surgery

Objectives: The aim of this study was to evaluate the use of intraoperative DynaCT (IODCT) to asses for successful aneurysm exclusion during endovascular aneurysm repair (EVAR). Methods: Patients with EVAR who underwent IODCT were retrospectively evaluated. IODCT was performed with the 8sDSA protocol using 10s contrast injection and a 20s image acquisition time on Artis zeego with syngo DynaCT (Siemens Healthcare, Forchheim, Germany). Findings were compared with post-procedural multi slice detector CT (MDCT). 2D images and 3D post-processing reconstructions (Aquarius Workstation, TeraRecon, San Mateo, United States) were reviewed. Radiation dose was documented and contrast doses were compared between the two modalities. Statistical analysis was performed using a paired T-test. Results are expressed as mean standard error of the mean. Results: On table, completion IODCT was performed on 12 patients undergoing EVAR (one infrarenal, 2 juxtarenal, 9 thoracoabdominal) and 5 patients undergoing treatment for persistent endoleaks (2 type Ia, 3 type III). 12 cases did not show an endoleak on completion IODCT, and this was confirmed on follow-up MDCT. In 5 cases, IODCT detected an endoleak at the completion of the procedure (one type Ia, one type II and 3 type III endoleaks). Type I and III endoleaks were immediately treated and were not detected on follow-up MDCT. The type II endoleak was not visualized on follow-up MDCT. No branch occlusions, stent fractures or component separations were noted on IODCT, and this correlated with follow-up MDCT. Mean skin dose was 0.552Gy ( 0.0099) for IODCT and dose length product was 2.665 Gy*cm ( 0.200) for MDCT. Mean contrast dose was 40cc for IODCT compared to 105.29cc ( 26.248) for MDCT (p 0.001). Conclusions: IODCT is of sufficient quality to serve as an imaging modality for evaluating aneurysm exclusion in EVAR with lower contrast dose than MDCT. It could potentially replace the need for follow-up MDCT.

Fenestrated Endovascular Grafting: The French Multicentre Experience

Purpose: This study aims to evaluate the medium-term outcomes following aortic aneurysm repair using fenestrated endografts performed in 16 French academic centres. Materials and methods: A retrospective analysis of prospectively collected data was carried out. This study included all patients treated with fenestrated endografts in France between May 2004 and January 2009. Patients were judged to be at high risk for open surgical repair. Fenestrated endografts were designed using computed tomography (CT) reconstructions performed on three-dimensional (3D) workstations. All patients were evaluated with CT, duplex ultrasound and plain film radiograph at discharge, 6, 12, 18 and 24 months, and annually thereafter. Results: A total of 134 patients (129 males) were treated over the study period. Median age and aneurysm size were 73 years (range 48–91 years) and 56 mm (range 45–91 mm), respectively. A total of 403 visceral vessels were perfused through a fabric fenestration, including 265 renal arteries. One early conversion to open surgery was required. Completion angiography and discharge CT scan showed that 398/403 (99%) and 389/394 (99%) respective target vessels were patent. The 30-day mortality rate was 2% (3/134). Pre-discharge imaging identified 16 (12%) endoleaks: three type I, 12 type II and one type III. After the procedure, transient or permanent dialysis was required in four (3%) and two (1%) patients, respectively. The median duration of follow-up was 15 months (range 2–53 months). No aneurysms ruptured or required open conversion during the follow-up period. Twelve of 131 patients (9%) died during follow-up (actuarial survival at 12 and 24 months: 93% and 86%, respectively). Median time from procedure to death was 15 months. None of these deaths were aneurysm related. Aneurysm sac size decreased by more than 5 mm in 52%, 65.6% and 75% of patients at 1, 2 and 3 years, respectively. Three (4%) patients had sac enlargement within the first year, associated with a persistent endoleak. During follow-up, four renal artery occlusions were detected. A total of 12 procedure-related re-interventions were performed in 12 patients during follow-up, including six to correct endoleaks, and five to correct threatened visceral vessels. Conclusions: The use of endovascular prostheses with graft material incorporating the visceral arteries is safe and effective in preventing rupture in the medium term. A predictable high mortality rate was depicted during follow-up in this high-risk cohort. Meticulous follow-up to assess sac behaviour and visceral ostia is critical to ensure optimal results.

Fenestrated Endovascular Grafting: The French Multicentre Experience

Purpose This study aims to evaluate the medium-term outcomes following aortic aneurysm repair using fenestrated endografts performed in 16 French academic centres. Materials and methods A retrospective analysis of prospectively collected data was carried out. This study included all patients treated with fenestrated endografts in France between May 2004 and January 2009. Patients were judged to be at high risk for open surgical repair. Fenestrated endografts were designed using computed tomography (CT) reconstructions performed on three-dimensional (3D) workstations. All patients were evaluated with CT, duplex ultrasound and plain film radiograph at discharge, 6, 12, 18 and 24 months, and annually thereafter. Results A total of 134 patients (129 males) were treated over the study period. Median age and aneurysm size were 73 years (range 48–91 years) and 56 mm (range 45–91 mm), respectively. A total of 403 visceral vessels were perfused through a fabric fenestration, including 265 renal arteries. One early conversion to open surgery was required. Completion angiography and discharge CT scan showed that 398/403 (99%) and 389/394 (99%) respective target vessels were patent. The 30-day mortality rate was 2% (3/134). Pre-discharge imaging identified 16 (12%) endoleaks: three type I, 12 type II and one type III. After the procedure, transient or permanent dialysis was required in four (3%) and two (1%) patients, respectively. The median duration of follow-up was 15 months (range 2–53 months). No aneurysms ruptured or required open conversion during the follow-up period. Twelve of 131 patients (9%) died during follow-up (actuarial survival at 12 and 24 months: 93% and 86%, respectively). Median time from procedure to death was 15 months. None of these deaths were aneurysm related. Aneurysm sac size decreased by more than 5 mm in 52%, 65.6% and 75% of patients at 1, 2 and 3 years, respectively. Three (4%) patients had sac enlargement within the first year, associated with a persistent endoleak. During follow-up, four renal artery occlusions were detected. A total of 12 procedure-related re-interventions were performed in 12 patients during follow-up, including six to correct endoleaks, and five to correct threatened visceral vessels. Conclusions The use of endovascular prostheses with graft material incorporating the visceral arteries is safe and effective in preventing rupture in the medium term. A predictable high mortality rate was depicted during follow-up in this high-risk cohort. Meticulous follow-up to assess sac behaviour and visceral ostia is critical to ensure optimal results.

Management of Type II Endoleaks: Preoperative versus Postoperative versus Expectant Management

Type II endoleak is a common phenomenon after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Most type II endoleaks are innocuous and transient and therefore do not require intervention. However, particularly persistent endoleaks could lead to aneurysm enlargement and delayed aortic rupture. Decreasing the occurrence rates of type II endoleaks can be attempted with prophylactic occlusion of the inferior mesenteric, hypogastric, and lumbar arteries. Although the efficacy and clinical benefit of prophylactic occlusion of aortic branches prior to EVAR or during the endovascular repair remain controversial, we anticipate an increased use of intraoperative embolization techniques. A reasonable treatment strategy in patients with type II endoleak may be to intervene in cases of increasing aneurysm size or if the endoleak does not resolve spontaneously within 6 months. Translumbar embolization has been shown to be more effective than transarterial embolization. An alternative embolization technique is transcaval embolization, which has shown success rates comparable to translumbar embolization. Type II endoleaks can also be treated during laparoscopy or laparotomy, but these techniques are more invasive and should be used only after failure of embolization techniques.

Endovascular Treatment of Ruptured Abdominal Aneurysm into the Inferior Vena Cava in Patient After Stent Graft Placement

We report the case of a patient who underwent endovascular repair and then reintervention as a result of the presence of a persistent endoleak complicated by an aortocaval fistula. A 76-year-old patient with a history of endovascular treatment for abdominal aortic aneurysm 2 years earlier had a palpable abdominal mass, high-output cardiac failure, and renal failure. A computed tomographic scan and angiography revealed bending of the right iliac limb, a type I endoleak, and rupture of the aneurysm into the inferior vena cava with aortocaval fistula formation. An iliac extension was positioned in the right external iliac artery. The procedure was finished successfully. Control angiography showed normal flow within the endoprosthesis, and both iliac arteries were without signs of endoleakage and aortocaval fistula. Ectatic common iliac artery may lead to a late distal attachment site endoleak. The application of a stent graft in cases of secondary aortocaval fistula after stent graft repair is a good option, particularly in emergency cases.

Endovascular treatment for thoracoabdominal aneurysms: outcomes and results☆

Endovascular treatment of thoracoabdominal aortic aneurysms (TAAA) in combination with selective open surgical revascularization may be an alternative to conventional surgical repair. We analyzed our patient outcomes after elective and emergent endovascular TAAA repair. Mortality and outcome data from 21 consecutive patients treated with endovascular TAAA repair between 2000 and 2006 were reviewed. An integrated neuroprotective approach was used on all patients. Mortality risk estimates for open surgery (OS) were calculated using the published risk assessment models and compared to our outcomes. Of the 21 patients, 9 had acute presentation: acute pain (9), rupture (6), and malperfusion (1). The celiac axis was overstented in 15. Nine hybrid open surgical procedures were performed: visceral/renal arteries (5), infrarenal aorta (3) and complete arch revascularization (1). Eleven patients had previous aortic surgery. Thirty-day mortality rate was 4.8% (1/21, predicted OS value 8.3%), 1-, 2- and 3-year survival was 80%. One hospital death occurred due to ischemic colitis after inferior mesenteric artery overstenting. No patient with acute presentation died during the initial hospital admission. There was no paraplegia (predicted OS rate 11.46%) and one event of delayed temporary paraparesis 3 weeks after hospital discharge corrected with raising the blood pressure. Other neurologic complications included one minor left pontine stroke with complete resolution, postoperative confusion (1) and saphenous nerve injury (1). No new late endoleaks occurred after initial complete aneurysm exclusion. Five patients underwent early (<30 days) and four patients underwent late endovascular reinterventions for persistent endoleak. An additional reintervention included percutaneous stenting of a superior mesenteric artery stenosis. Actual freedom from late reintervention was 81%, and 76% at 1-, 2 and 3-year follow-up. Late major adverse events included one stent infection leading to multi-organ failure and death. Endovascular treatment of thoracoabdominal aneurysms with selective visceral and renal revascularization is associated with low mortality and can only be effectively performed by a surgeon. High-risk patients and those with acute presentation appear to benefit most from this therapy. Early results up to three years of this therapy are encouraging, but further follow up to validate long-term results is required.

Basic fibroblast growth factor slow release stent graft for endovascular aortic aneurysm repair: A canine model experiment

Persistent endoleak and endotension, complications after endovascular aortic repair, may be caused by an unorganized thrombus inside the aneurysm. The experimental study was designed to evaluate the effectiveness of stent grafts (S/Gs) with slow release of basic fibroblast growth factor (bFGF) for the organization. The S/Gs were constructed of self-expanding Z stent covered with expanded polytetra fluoroethylene graft, and coated with elastin to be able to bind and slowly release bFGF. Five elastin-coated S/Gs with bFGF (bFGF-S/Gs) and without bFGF (C-S/Gs) were placed in the normal canine aorta respectively. The thoracic aortic aneurysm models were surgically created with a jugular vein patch in 12 beagles. S/Gs with six holes, for creating endoleaks, were used in the experiment of aneurysmal repair. The bFGF-S/Gs (n = 6) and C-S/Gs (n = 6) were implanted. The beagles were sacrificed at two weeks after the endovascular procedure and examined histologically. The bFGF-S/Gs induced six times the intimal proliferation of the C-S/Gs in normal aorta. Twelve animals had successfully created aneurysms, and had endoleaks just after the endovascular procedure. At two weeks after the endovascular procedure, the percentage of fibrous area in the aneurysmal cavity treated with bFGF-S/G (35.7 +/- 4.3%) was significantly greater than C-S/G (13.6 +/- 2.2%) (P < .01). bFGF-S/Gs are effective for accelerating organization of the aneurysm cavity and developing neointima. Further research on bFGF-S/Gs would clarify the association of endoleaks.

Total Robotic Ligation of Inferior Mesenteric Artery for Type II Endoleak after Endovascular Aneurysm Repair

We present a case of totally robotic ligation of the inferior mesenteric artery (IMA) for treatment of a persistent endoleak from the IMA into the aneurysm sac after endovascular aneurysm repair (EVAR). An 84-year-old male underwent EVAR with a Gore Excluder stent graft for an asymptomatic infrarenal abdominal aortic aneurysm. Follow-up computed tomographic (CT) scan showed persistent type II endoleak from the IMA, with progressive enlargement of the aneurysm sac from 5 to 6.1 cm over an 18-month period. In this case, the patient underwent ligation of the IMA using the da Vinci Surgical System for the treatment of retrograde flow into the aneurysm sac. The total operating time was 249 min; of this, the robotic assistance time was approximately 180 min. No intraoperative complications occurred. The estimated blood loss was 50 mL and the urine output 650 mL. The patient was extubated immediately after the procedure and tolerated a regular diet the following day. He was discharged home with a urinary catheter on postoperative day 2. CT scan postoperatively and at 3-month follow-up demonstrated an occluded IMA and stabilization of the aneurysm sac size.

ENDOVASCULAR GRAFTING OF THE THORACIC AORTA, AN EVOLVING THERAPY: TEN‐YEAR EXPERIENCE IN A SINGLE CENTRE

Surgical therapy for the thoracic aorta carries a high morbidity and mortality. Endovascular therapy for aneurysms and its adaptation to the thoracic aorta over the past 10 years is an exciting advance. This is a retrospective review of endovascular grafting of the thoracic aorta during the past decade at Royal Prince Alfred Hospital and the outcomes achieved over this period. A retrospective review of all patients at our institution who underwent endovascular grafting of the thoracic aorta between March 1995 and March 2005 was carried out. Data were analysed using Stata version 8.0 (Stata corporation, College Station, TX, USA). Sixty-five patients underwent endovascular stent grafting of the thoracic aorta. The indications were degenerative aneurysm (31), Stanford type B dissection (23) both acute (12) and chronic (11), traumatic transection (9) and penetrating ulcer (2). There were no conversions to open repair. Twenty-two patients required additional procedures, six of which were unplanned. The median age was 65 (range 18-85), 68% of patients were men. The median procedure time was 115 min (range 55-240 min). Mean hospital stay was 9.8+/-7.3 days and high dependency/intensive care unit stay 1.5+/-3.2 days. Thirty-day mortality was 0 in 41 for elective cases (one patient (2.5%) died 37 days post-procedure) and 12% (3 of 25) for emergency cases. Complications occurred in 20 of 41 (49%) elective cases and 14 of 24 (58%) emergency cases within the first 30 days. The most frequent major complications were neurological including paraplegia (transient 2 of 65, permanent (2 of 65)) and stroke (4 of 65). Other complications included endoleak (12 of 65), acute renal failure (1 of 65), and brachial artery false aneurysm (1 of 65). The mean length of follow up was 22.5 months (range, 1-97 months). Six patients required further endovascular procedures for persistent endoleak or ongoing perfusion of chronic dissection. Late deaths (>30 days) related to the endovascular treatment occurred in two patients (3%). Endovascular grafting of the thoracic aorta is an evolution in the treatment of thoracic aortic pathology. The results of elective endovascular grafts were acceptable. Emergency procedures had a higher incidence of complications and death. Improvement in graft technology, design and deployment are required.

An IVUS-Based Approach to Traumatic Aortic Rupture, with a Look at the Lesion from inside

To review a single-institution experience with endovascular repair of acute traumatic aortic rupture (ATAR) performed on an emergency basis using intravascular ultrasound (IVUS) exclusively as the navigation tool for stent-graft implantation (no arteriography). Between September 1998 and November 2006, 26 consecutive patients (19 men; mean age 38+/-19 years, range 15 to 83) underwent endovascular repair of ATAR performed by a surgical team using IVUS and fluoroscopy for lesion characterization and stent-graft deployment guidance. Transesophageal echocardiography was routinely used in all patients to visualize the aortic lesion and rule out residual flow after device deployment. Sealing of the aortic tear was evaluated by postoperative contrast-enhanced computed tomography. IVUS revealed an extensive disruption of the tunica intima and media (>180 degrees ) in 46% (12/26) of patients; the disruption was circumferential in 3 cases, with pseudocoarctation. The aortic diameter at the site of rupture measured 24+/-4 mm. Primary technical success was 92% (24/26); 1 persistent but small proximal endoleak and an intraoperative death (4% in-hospital mortality) from abdominal bleeding in an octogenarian accounted for the failures. Procedure-related complications (2, 8%) included the aforementioned endoleak and a minor stroke secondary to cerebral embolization. There was no paraplegia associated with the repairs. Endovascular repair of acute traumatic aortic disruption yields promising results, with high technical success and minimal procedure-related morbidity. IVUS as the primary navigation tool for device implantation allows prompt endovascular setup, instant aortic measurements, and precise visualization of the aortic disruption.

Predictive Factors, Morphologic Effects, and Proposed Treatment Paradigm for Type II Endoleaks after Repair of Infrarenal Abdominal Aortic Aneurysms

To evaluate the predictive factors and outcome of type II endoleaks after endovascular repair of infrarenal abdominal aortic aneurysms with use of a Zenith endograft. Patients classified at high risk were enrolled in a prospective study and evaluated with serial cross-sectional imaging techniques. The effect of a type II endoleak on sac behavior and associated factors were analyzed. Type II endoleaks were categorized as absent, persistent, or transient, and the morphologic effects were determined. Logistic regression and classification tree were used to predict which patients may be at risk for persistent type II endoleaks. A total of 273 patients were enrolled. Patients were excluded in the absence of a minimum of 6 months digital data or the presence of endoleak not classified as type II. Two hundred four patients met inclusion criteria, with a median follow-up period of 24 months (range, 6-60 months). Early type II endoleak was detected in 35 patients (17%), which resolved spontaneously in 17 cases. There were 18 patients with persistent endoleak, 17 patients with transient type II endoleak, and 169 patients with no endoleak. Aneurysm enlargement was detected in seven patients with persistent endoleak (39%), no patients with transient type II endoleak, and one patient with no endoleak. No variables were predictive of the development of persistent endoleak. The relative risk of aneurysmal growth was 77 with persistent endoleak. Successfully treated persistent endoleaks were not associated with any growth. Persistent endoleaks are associated with sac growth. Transient type II endoleaks have a benign course and do not require treatment. Successful treatment of persistent endoleak ameliorates the risk of growth.

Persistent type 2 endoleak after endovascular repair of abdominal aortic aneurysm is associated with adverse late outcomes

Type 2 endoleak occurs in up to 20% of patients after endovascular aneurysm repair (EVAR), but its long-term significance is debated. We reviewed our experience to evaluate late outcomes associated with type 2 endoleak. During the interval January 1994 to December 2005, 873 patients underwent EVAR. Computed tomography (CT) scan assessment was performed < or =1 month of the operation and at least annually thereafter. Sequential 6-month CT scan follow-up was adopted for those patients with persistent type 2 endoleaks, and reintervention was limited to those with sac enlargement >5 mm. Study end points included overall survival, aneurysm sac growth, reintervention rate, conversion to open repair, and abdominal aortic aneurysm (AAA) rupture. Preoperative variables and anatomic factors potentially associated with these endpoints were assessed using multivariate analysis. We identified 164 (18.9%) patients with early (at the first follow-up CT scan) type 2 endoleaks. Mean follow-up was 32.6 months. In 131 (79.9%) early type 2 endoleaks, complete and permanent leak resolution occurred < or =6 months. Endoleaks persisted in 33 patients (3.8% of total patients; 20.1% of early type 2 endoleaks) for >6 months. Transient type 2 endoleak (those that resolved < or =6 months of EVAR) was not associated with adverse late outcomes. In contrast, persistent endoleak was associated with several adverse outcomes. AAA-related death was not significantly different between patients with and without a type 2 endoleak (P = .78). When evaluating patients with no early endoleak vs persistent endoleak, freedom from sac expansion at 1, 3, and 5 years was 99.2%, 97.6%, and 94.9% (no leak) vs 88.1%, 48.0%, and 28.0% (persistent) (P < .001). Patients with persistent endoleak were at increased risk for aneurysm sac growth vs patients without endoleak (odds ratio [OR], 25.9; 95% confidence interval [CI] 11.8 to 57.4; P < .001). Patients with a persistent endoleak also had a significantly increased rate of reintervention (OR, 19.0; 95% CI, 8.0 to 44.7); P < .001). Finally, aneurysm rupture occurred in 4 patients with type 2 endoleaks. Freedom from rupture at 1, 3, and 5 years for patients with a persistent type 2 endoleak was 96.8%, 96.8%, and 91.1% vs 99.8%, 98.5%, and 97.4% for patients without a type 2 endoleak. Multivariate analysis demonstrated persistent type 2 endoleak to be a significant predictor of aneurysm rupture (P = .03). Persistent type 2 endoleak is associated with an increased incidence of adverse outcomes, including aneurysm sac growth, the need for conversion to open repair, reintervention rate, and rupture. These data suggest that patients with persistent type 2 endoleak (>6 months) should be considered for more frequent follow-up or a more aggressive approach to reintervention.