F. Bekkema

Stent fractures in the Hemobahn/Viabahn stent graft after endovascular popliteal aneurysm repair.

OBJECTIVE During the last decade, endovascular repair of popliteal artery aneurysms (PAAs) has become a valid alternative to open repair. This study analyzes the incidence and origin of stent graft fractures after endovascular repair, its impact on patency, and strategies to prevent fractures. METHODS Data of 78 atherosclerotic PAAs in 64 patients were gathered in a prospectively-held database from 1998 to 2009. All x-rays were reviewed to detect stent fractures. Only circumferential fractures were included for analysis; localized strut fractures were excluded. Clinical endpoints were circumferential stent fracture, occlusion, and clinical status of the patient. RESULTS Mean follow-up time was 50 months (range, 1-127 months). Fifteen circumferential stent fractures occurred in 13 (16.7%) patients. The majority of stent fractures (93.3%) were associated with the use of multiple stent grafts. At univariate analysis, younger age was identified as the only significant predictor for stent fracture (P = .007). The cumulative stent fracture-free survival was estimated at 78% and 73% at 5- and 10-year follow-up, respectively. The cumulative primary patency rate, defined as time to occlusion, was not different for the fracture group compared with the nonfracture group (P = .284). CONCLUSIONS The incidence of stent fractures after endovascular PAA repair is probably underreported in the literature. Stent graft fractures mainly occur at overlap zones and are associated with younger age of the patient. Fracture of the stent did not significantly influence patency of the stent graft.

Mortality of ruptured abdominal aortic aneurysm treated with open or endovascular repair

OBJECTIVES The study defined the selection criteria used for treatment of ruptured abdominal aortic aneurysms (RAAAs) and reviewed results during a 5-year period. METHODS From 2002 on, our tertiary referral center adopted a protocol of selective use of endovascular repair for RAAAs. The study included all patients with a proven RAAA who were admitted to our hospital from 2002 to 2006. The primary outcome measure was surgical mortality. RESULTS A total of 187 patients were admitted with an acute AAA, and an RAAA was confirmed 135 (72%) by computed tomography scanning or at laparotomy, and 125 (93%) were treated, 89 by open means and 36 by endovascular means. The overall mortality rate was 24% and the mortality rate was 13.9% for endovascular repair. Endovascular repair was consistently used more often in patients with favorable anatomy and in patients who were hemodynamically more stable. There were considerable differences in approach between the four consultant vascular surgeons. The overall evaluation and inclusion for endovascular treatment increased during the study period. CONCLUSIONS A strict protocol for admission, evaluation, and treatment of RAAA, with selective use of endovascular repair, resulted in low mortality rates in our center.

Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair

OBJECTIVE Fenestrated endovascular abdominal aortic aneurysm repair (F-EVAR) has been introduced for treatment of aneurysms in which visceral arteries are incorporated. Patency of target vessels has been reported to be excellent. Results of the use of stent grafts to accommodate visceral arteries in F-EVAR are presented in this study, including an overview of factors that affect outcome. METHODS All patients treated with fenestrated stent grafts in a single center between November 2001 and October 2011 were reviewed. Patients treated for suprarenal, juxtarenal, and infrarenal short-necked aortic aneurysms were included. Patients with thoraco-abdominal aneurysms or aneurysms treated with grafts with fixed side branches were excluded. Polytetrafluoroethylene covered stents were used routinely since June 2005. Target vessels and stents were examined using computed tomography angiography reconstructions. Primary end points were primary patency, defined as the absence of occlusion, and loss of renal function. Secondary end points were technical success, stenosis (defined as a ≥50% angiographic diameter reduction), stent fracture, and mortality. RESULTS A total of 138 patients with a median age of 73 years (range, 50-91 years) met the inclusion criteria. Median computed tomography angiography follow-up was 13 months (range, 1-97 months). In total, 392 target vessels were provided with 140 scallops and 252 fenestrations. Visceral stents (-grafts) were placed in 254 target vessels. Technical success was obtained in 249 arteries (98.0%). Overall stent patency of target vessels was 95.7% at 1 year and 88.6% at 4 years. Renal artery stent patency was 97.4% at 1 year and 91.2% at 4 years (96.8% and 89.1% for uncovered stents; 97.3% and 92.4% for covered stents, respectively). There was no significant difference in patency between covered and uncovered stents in renal arteries (P = .71). Renal artery stenosis occurred in 26 stented arteries (11.3%) and occlusion in seven arteries. Renal artery stent stenosis occurred significantly more in uncovered than in covered stents (P = .04). Stent fractures occurred more in uncovered than in covered stents (P = .01) and was associated with a significantly lower visceral stent patency rate (P < .01). During follow-up, 13 patients developed permanent renal function impairment (9.4%), of which two required permanent dialysis (1.4%). Renal dysfunction was significantly associated with renal stent occlusion or stenosis (P < .01). CONCLUSIONS Patency rates of visceral artery stent (-grafts) in F-EVAR were 95.7% at 1 year and 88.6% at 4 years. Patency rates were affected by stent fractures, which occurred more in uncovered compared with covered stents. Renal artery stent stenosis occurred more in uncovered compared with covered stents. Renal dysfunction was significantly associated with renal stent occlusion or stenosis.

Fenestrated Stent-Grafts for Salvage of Prior Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES To review our experience with fenestrated endovascular aneurysm repair (F-EVAR) to treat complications after previous standard infrarenal endovascular aneurysm repair (EVAR). METHODS A prospectively maintained database including all consecutive patients with juxtarenal abdominal aortic aneurysm that were treated with F-EVAR after failed previous EVAR within the period March 2002 to November 2012 at the University Medical Center of Groningen, Netherlands (up to October 2009), and the Klinikum Nürnberg Süd, Germany (from November 2009) was analyzed. Evaluated outcomes included initial technical success, operative mortality and morbidity, and late procedure-related events with regard to survival, target vessel patency, endoleak, renal function, and reintervention. RESULTS A total of 26 patients (24 male, mean age 73.2 ± 6.5 years) were treated. All patients had proximal anatomies precluding endovascular reintervention with standard techniques. In 23 patients a fenestrated proximal cuff was used, and in three patients a bifurcated fenestrated stent graft. Technical success was achieved in 24 (92.3%) patients. One patient required on-table open conversion because of impossibility to retrieve the top cap as a result of twist of the ipsilateral limb. In the second patient the right kidney was lost due to inadvertent stenting in a smaller branch of the renal artery. Catheterization difficulties, all related to the passage through the limbs or struts of the previous stent graft, were encountered in 11 (42.3%) cases, including five (19.2%) patients with iliac access problems and six (23.1%) with challenging renal catheterization. Operative target vessel perfusion success rate was 94.6% (70/74). Operative mortality was 0%. Mean follow-up was 26.8 ± 28.5 months. No proximal type I endoleak was present on first postoperative CTA. The mean aneurysm maximal diameter decreased from 73 ± 20 mm to 66.7 ± 21 mm (p < .05). There were six late deaths, one of them aneurysm related. Estimated survival rates at 1 and 2 years were 94.1 ± 5.7% and 87.4 ± 8.4%, respectively. Patency during follow-up for the target vessels treated successfully with a fenestrated stent graft was 100% (70/70). Reintervention was required in four cases, including one acute conversion due to rupture, one for iliac limb occlusion and two for type Ib and II endoleak. Renal function deterioration was observed solely in the two cases of primary technical failure. CONCLUSIONS F-EVAR represents a feasible option for the repair of juxtarenal abdominal aortic aneurysm after prior EVAR failure. It is advantageous in terms of mortality and less morbid than open surgery, but is associated with increased technical challenges because of the previously placed stent graft. Outcome seems related to initial technical success.

Type 2 diabetes mellitus is associated with an imbalance in circulating endothelial and smooth muscle progenitor cell numbers

Aims/hypothesisIndividuals with type 2 diabetes mellitus have increased rates of macrovascular disease (MVD). Endothelial progenitor cells (EPCs), circulating angiogenic cells (CACs) and smooth muscle progenitor cells (SMPCs) are suggested to play a role in the pathogenesis of MVD. The relationship between vasoregenerative EPCs or CACs and damaging SMPCs and the development of accelerated MVD in diabetes is still unknown. We tried to elucidate whether EPC, CAC and SMPC numbers and differentiation capacities in vitro differ in patients with and without diabetes or MVD.MethodsPeripheral blood was obtained from insdividuals with and without diabetes and MVD (coronary or peripheral artery disease). EPC and SMPC numbers were determined with flow cytometry. Furthermore, CAC and SMPC numbers were quantified after in vitro culture. Their in vitro differentiation capacity was investigated with real-time RT-PCR and quantitative immunofluorescence.ResultsIn diabetic patients both EPC and CAC levels were reduced (1.3-fold [p < 0.05] and 1.5-fold [p < 0.05], respectively). CAC outgrowth from diabetic patients with MVD was reduced 1.5-fold compared with diabetic patients without MVD (p < 0.05). SMPC levels were similar between diabetic patients and healthy controls. The CAC/SMPC ratio of in vitro cultured progenitor cells was reduced 2.3-fold in samples from diabetic patients (p < 0.001). The differentiation capacity of CACs and SMPCs in vitro remained similar independently of diabetes or MVD.Conclusions/interpretationThe ratio between EPCs or CACs and SMPCs is disturbed in type 2 diabetes in favour of SMPCs. This may translate into reduced vascular repair capacity, thereby promoting MVD in type 2 diabetes.

Results of Endovascular Repair of TAAA in the First 50 Patients

BACKGROUND Developments with fenestrated and branched stent grafts have opened the way to treat complex aortic aneurysms involving the visceral arteries. First reports on endovascular treatment of thoracoabdominal aneurysms have demonstrated the feasibility of the technique. METHODS A literature review and results of first 50  patients treated with a custom-made Zenith device with fixed branches are presented. Most of the patients were refused open surgery mainly for the extent of the disease combined with co-morbidity, which included in most patients a combination of several risk factors. Mean aneurysm size was 71 mm and extent of the aneurysm was type  I (n = 9), type  II (n = 13), type  III (n = 19), and type  IV (n = 9), respectively. RESULTS Primary and primary assisted technical successes in our series were 88 % (44 / 50) and 92 % (46 / 50), respectively. One patient died on day  1 from an intraoperative aneurysm rupture. In two patients a renal artery was lost, one due to rupture and one due to malpositioning of the bridging stent graft. In a fourth patient, a celiac artery could not be catheterised and was lost. Finally, in two more patients, catheterisation of in total three renal arteries proved impossible. This was solved by a retrograde approach for two renal arteries via laparotomy in one patient, and a spleno-renal bypass in the other patient. Thirty-day mortality was 8 %. Estimated survival at 6  months, 1  year, and 2  years was 91.2 %, 79.8 %, and 69.7 %, respectively. Freedom of reintervention of all kinds at 1 and 2  years was 81.9 % and 73.7 %, respectively. CONCLUSION Results of fully endovascular repair of thoracoabdominal aneurysms in a high-risk cohort are promising. A learning curve should be expected. Although longer term results need to be awaited, it is likely that endovascular repair of thoracoabdominal aneurysms will become a preferential treatment option for many patients in the future.

Fenestrated endografting of juxtarenal aneurysms after open aortic surgery

INTRODUCTION Juxtarenal aneurysms after previous surgical aortic reconstruction constitute a complex clinical scenario. Open redo surgery is technically demanding and usually requires suprarenal or supraceliac clamping. Standard endovascular repair is prohibited due to the lack of a proximal landing zone. We present our experience with fenestrated endovascular aneurysm repair (F-EVAR) in the treatment of juxtarenal aneurysms after previous open surgery. METHODS A prospectively maintained database including all patients with juxtarenal abdominal aortic aneurysm after previous surgical reconstruction that underwent F-EVAR within the period from November 2003 to February 2013 under the instruction of the senior author. Evaluated outcomes included initial technical success and operative mortality and morbidity as well as late survival, target vessel patency, aneurysm diameter regression, renal function, and reintervention. RESULTS A total of 35 patients (33 male; mean age, 71.5 ± 6.2 years) were treated. Median interval from the primary surgical reconstruction was 126 months (range, 48-223 months). All patients had proximal anatomies precluding standard endovascular techniques and were considered high risk for open repair due to their comorbidities and redo nature of the operation. In total, 111 vessels were targeted: 77 with small fenestrations, 33 with scallops, and 1 vessel with a downward branch. The operation was completed by totally endovascular means in 34 patients (97.1%). In one patient, a retroperitoneal approach was needed to gain retrograde access to a renal artery. Operative target vessel perfusion success rate was 100%. Operative mortality was 0% and median hospital stay 6 days (range, 2-40 days). Mean follow-up (FU) was 37.5 ± 25 months. Mean aneurysm maximal diameter decreased from 60 ± 4 mm to 47 ± 8 mm (P < .05). No type I endoleak was diagnosed, and no reintervention was required during FU. There were eight late deaths, all unrelated to the aneurysm. Estimated survival rates at 1, 2, and 4 years were 92.0% ± 5.5%, 82.8% ± 7.9% and 76.9% ± 9.3%, respectively. Three target vessel occlusions occurred during FU. One patient suffered a bilateral renal artery occlusion resulting in dialysis. In a second patient, one renal artery occluded without clinical symptoms. No other cases of renal function deterioration were observed. CONCLUSIONS F-EVAR is a valid treatment option for juxtarenal aneurysms after previous surgical reconstruction. F-EVAR represents a less morbid alternative to redo open surgery, has a high technical success rate, and shows durability in mid-term FU.

Update on Endovascular Repair for Ruptured Abdominal Aortic Aneurysms

Rupture of an abdominal aortic aneurysm (AAA) is a life-threatening condition with an estimated overall mortality of 90 per cent (1). Mortality rate in patients who reach hospital alive, remains as high as 48%, with multiorgan failure being the predominant cause (2). In this setting, endovascular aneurysm repair (EVAR) has been suggested as a promising alternative to open surgery. The first report of emergency endovascular aneurysm repair (eEVAR) was published in 1994 (3). Several cohort studies followed with promising initial results. An obstacle to widespread use of eEVAR is the need for an endovascular team to be available at all times. In addition, a subgroup of patients with ruptured aneurysm cannot tolerate any delay of treatment, such as that caused by the preoperative CT-scan needed for eEVAR. The aim of this study was to summarize the progression to date in the field of emergency EVAR and outline upcoming developments. Secondly we describe the key components of an emergency EVAR strategy.