Johanna M. Hendriks

Endovascular versus Conventional Open Repair of Acute Abdominal Aortic Aneurysm: Feasibility and Preliminary Results

PURPOSEnTo evaluate the feasibility of endovascular treatment of acute abdominal aortic aneurysm (AAA) with commercially prepared bifurcated systems.nnnMETHODSnFrom January through July 2001, 22 patients (17 men; mean age 73.6 years, range 59-89) were referred with an acute (symptomatic/ruptured) AAA. Six patients were treated with emergent open surgery because of hemodynamic instability, but the other 16 patients underwent computed tomographic angiography with multidirectional reconstruction. Six (27%) aneurysms were suitable for endovascular repair (EVR) and were successfully treated. Procedural variables, morbidity, and mortality were compared between the EVR group and 6 patients of equivalent hemodynamic status from among the conventionally treated patients.nnnRESULTSnThere was no mortality in either group. The median aneurysm diameter in the EVR group was 63 mm (range 48-84) versus 80 mm (45-82) in the matched surgically treated AAAs (p=0.628). Procedural duration was 193 minutes (150-265) for the EVR group compared to 203 minutes (130-270) for the matched group (p=0.630). Median blood loss was significantly less (p=0.010) in the EVR group (125 versus 3400 mL). Median length of stay (LOS) in intensive care was 8 hours (0-21) versus 62 hours (48-112) for the surgical group (p=0.004). Hospital LOS was significantly reduced (p=0.024) for the EVR patients (7.5 [2-16] versus 15.5 [10-34] days).nnnCONCLUSIONSnEndovascular treatment of acute aneurysm is feasible, and preliminary results are promising.

Adequate Seal and No Endoleak on the First Postoperative Computed Tomography Angiography as Criteria for No Additional Imaging Up to 5 Years after Endovascular Aneurysm Repair

OBJECTIVEnIntensive image surveillance after endovascular aneurysm repair is generally recommended due to continued risk of complications. However, patients at lower risk may not benefit from this strategy. We evaluated the predictive value of the first postoperative computed tomography angiography (CTA) characteristics for aneurysm-related adverse events as a means of patient selection for risk-adapted surveillance.nnnMETHODSnAll patients treated with the Low-Permeability Excluder Endoprosthesis (W. L. Gore & Assoc, Flagstaff, Ariz) at a tertiary institution from 2004 to 2011 were included. First postoperative CTAs were analyzed for the presence of endoleaks, endograft kinking, distance from the lowermost renal artery to the start of the endograft, and for proximal and distal sealing length using center lumen line reconstructions. The primary end point was freedom from aneurysm-related adverse events. Multivariable Cox regression was used to test postoperative CTA characteristics as independent risk factors, which were subsequently used as selection criteria for low-risk and high-risk groups. Estimates for freedom from adverse events were obtained using Kaplan-Meier survival curves.nnnRESULTSnIncluded were 131 patients. The median follow-up was 4.1 years (interquartile range, 2.1-6.1). During this period, 30 patients (23%) sustained aneurysm-related adverse events. Seal lengthxa0<10 mm and presence of endoleak were significant risk factors for this end point. Patients were subsequently categorized as low-risk (proximal and distal seal length ≥10 mm and no endoleak, nxa0= 62) or high-risk (seal lengthxa0<10 mm or presence of endoleak, or both; nxa0= 69). During follow-up, four low-risk patients (3%) and 26 high-risk patients (19%) sustained events (Pxa0< .001). Four secondary interventions were required in three low-risk patients, and 31 secondary interventions in 23 high-risk patients. Sac growth was observed in two low-risk patients and in 15 high-risk patients. The 5-year estimates for freedom from aneurysm-related adverse events were 98% for the low-risk group and 52% for the high-risk group. For each diagnosis, 81.7 image examinations were necessary in the low-risk group and 8.2 in the high-risk group.nnnCONCLUSIONSnOur results suggest that the first postoperative CTA provides important information for risk stratification after endovascular aneurysm repair when the Excluder endoprosthesis is used. In patients with adequate seal and no endoleaks, the risk of aneurysm-related adverse events was significantly reduced, resulting in a large number of unnecessary image examinations. Adjusting the imaging protocol beyond 30 days and up to 5 years, based on individual patients risk, may result in a more efficient and rational postoperative surveillance.

Clinical outcome and morphologic analysis after endovascular aneurysm repair using the Excluder endograft

OBJECTIVEnLong-term follow-up after endovascular aneurysm repair (EVAR) is very scarce, and doubt remains regarding the durability of these procedures. We designed a retrospective cohort study to assess long-term clinical outcome and morphologic changes in patients with abdominal aortic aneurysms (AAAs) treated by EVAR using the Excluder endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz).nnnMETHODSnFrom 2000 to 2007, 179 patients underwent EVAR in a tertiary institution. Clinical data were retrieved from a prospective database. All patients treated with the Excluder endoprosthesis were included. Computed tomography angiography (CTA) scans were retrospectively analyzed preoperatively, at 30 days, and at the last follow-up using dedicated tridimensional reconstruction software. For patients with complications, all remaining CTAs were also analyzed. The primary end point was clinical success. Secondary end points were freedom from reintervention, sac growth, types I and III endoleak, migration, conversion to open repair, and AAA-related death or rupture. Neck dilatation, renal function, and overall survival were also analyzed.nnnRESULTSnIncluded were 144 patients (88.2% men; mean age, 71.6 years). Aneurysms were ruptured in 4.9%. American Society of Anesthesiologists classification was III/IV in 61.8%. No patients were lost during a median follow-up of 5.0 years (interquartile range, 3.1-6.4; maximum, 11.2 years). Two patients died of medical complications ≤ 30 days after EVAR. The estimated primary clinical success rates at 5 and 10 years were 63.5% and 41.1%, and secondary clinical success rates were 78.3% and 58.3%, respectively. Sac growth was observed in 37 of 142 patients (26.1%). Cox regression showed type I endoleak during follow-up (hazard ratio, 3.74; P = .008), original design model (hazard ratio, 3.85; P = .001), and preoperative neck diameter (1.27 per mm increase, P = .006) were determinants of sac growth. Secondary interventions were required in 32 patients (22.5%). The estimated 10-year rate of AAA-related death or rupture was 2.1%. Overall life expectancy after AAA repair was 6.8 years.nnnCONCLUSIONSnEVAR using the Excluder endoprosthesis provides a safe and lasting treatment for AAA, despite the need for maintained surveillance and secondary interventions. At up to 11 years, the risk of AAA-related death or postimplantation rupture is remarkably low. The incidences of postimplantation sac growth and secondary intervention were greatly reduced after the introduction of the low-permeability design in 2004.

The Carotid Body Tumor

A 63-year old female was referred to our hospital because she had a mass on the right side of the neck. The swelling had slowly progressed in a couple of months. Besides problems with swallowing there were no other complaints. Her previous medical history was unremarkable and she could not remember any family members with similar lesions. Physical examination showed a non-tender mass with a diameter of around 6 cm located just anterior of the sternocleidomastoid muscle in the anterior triangle of the neck. The mass was mobile in a back-forward direction but could not be moved in a cranial-caudal direction. No signs of cranial nerve deficits were detected. An ultrasound examination showed a highly vascularized structure in the bifurcation between the internal and external carotid artery (Fig. 33.1).

Endoscopic aneurysm sac fenestration as a treatment option for growing aneurysms due to type II endoleak or endotension

Purpose: To evaluate endoscopic fenestration as a treatment option for growing aneurysm due to a type II endoleak or endotension after endovascular aneurysm repair (EVAR). Methods: Eight patients (7 men; median age 69 years, range 55–79) who underwent “successful” EVAR were diagnosed with a growing aneurysm due to a type II endoleak (n = 4) or endotension (n=4). Surgical intervention consisted of endoscopic fenestration of the sac and removal of all the thrombus material, preceded by clipping of the inferior mesenteric and all lumbar arteries in cases of endoleak. Fluid samples from the fenestrated aneurysm sac were analyzed for the presence of microorganisms and fibrin degradation products (FDP) and/or D-dimers. Results: The median duration of operation was 220 minutes (range 111–333). There was no perioperative mortality. In one patient, the endoscopic procedure was converted to an open fenestration procedure. Seven patients had uncomplicated follow-up and a clear decrease in the diameter of the sac; one patient was converted to open repair owing to continued sac growth despite fenestration. Bacterial cultures were negative in all patients, but high levels of FDP and/or D-dimers were found in all available samples, indicating continued fibrinolysis. Conclusion: Endoscopic fenestration, with or without endoscopic clipping of all side branches, seems to be an effective, reliable and minimally invasive treatment option for patients with a growing aneurysm due to type II endoleak or endotension. The high levels of FDP and/or D-dimers in the aneurysm sac are suggestive of hyperfibrinolysis, which may play an important role in aneurysm growth after EVAR.

Conservative management of persistent aortocaval fistula after endovascular aortic repair

Endovascular repair is a valid alternative for patients with abdominal aortic aneurysms. However, in patients with concomitant aortocaval fistulas, type II endoleaks may result in a persistent communication between the aneurysm sac and the inferior vena cava. In these patients, prompt closure of the persistent fistula has been advocated. We present a patient with an abdominal aortic aneurysm, with aortocaval fistula, who was managed endovascularly. Aneurysm sac shrinkage was observed despite persistent aortocaval communication due to type II endoleak. This case demonstrates that conservative management of type II endoleaks associated with persistent aortocaval fistulas is possible and may result in favorable aneurysm sac remodelling.

Radial Force Measurements in Carotid Stents: Influence of Stent Design and Length of the Lesion

PURPOSEnTo assess the differences in radial force of carotid stents and whether the length of the lesion influences the measurements.nnnMATERIALS AND METHODSnDifferent models of tapered stents of similar size (length, 30 mm) were used. The tapered nitinol Acculink, Protégé, and Cristallo Ideale carotid artery stents and the straight, braided Elgiloy carotid Wallstent were compared. A measurement device consisting of three film loops along the stent body connected to aluminium rods with copper strain gauges was developed. Five stents of each type were deployed within 3-mm stenoses in simulated long (26 mm) and short (8 mm) stenoses.nnnRESULTSnIn the short stenosis simulation, the greatest radial force was seen in the Protégé stent, at 3.14 N ± 0.45, followed by the Cristallo Ideale stent (1.73 N ± 0.51), Acculink (1.16 N ± 0.21), and Wallstent (0.84 N ± 0.10; P < .001). In the long stenosis simulation, peak radial force again was highest in the Protégé stent (1.67 N ± 0.37), but the Acculink stent was second (0.95 N ± 0.12) and the Wallstent third (0.80 N ± 0.06). The Cristallo Ideale stent, in contrast to the short stenosis simulation, produced the least radial force (0.44 N ± 0.13) in the long stenosis simulation (P = .001).nnnCONCLUSIONSnRadial forces exerted by carotid stents vary significantly among stent designs. Differences between stent types are dependent on the length of the stenosis. An understanding of radial force is necessary for a well-considered choice of stent type in each individual patient.

Clinical outcome and morphologic determinants of mural thrombus in abdominal aortic endografts

OBJECTIVEnEndograft mural thrombus has been associated with stent graft or limb thrombosis after endovascular aneurysm repair (EVAR). This study aimed to identify clinical and morphologic determinants of endograft mural thrombus accumulation and its influence on thromboembolic events after EVAR.nnnMETHODSnA prospectively maintained database of patients treated by EVAR at a tertiary institution from 2000 to 2012 was analyzed. Patients treated for degenerative infrarenal abdominal aortic aneurysms and with available imaging for thrombus analysis were considered. All measurements were performed on three-dimensional center-lumen line computed tomography angiography (CTA) reconstructions. Patients with thrombus accumulation within the endografts main body with a thickness >2 mm and an extension >25% of the main bodys circumference were included in the study group and compared with a control group that included all remaining patients. Clinical and morphologic variables were assessed for association with significant thrombus accumulation within the endografts main body by multivariate regression analysis. Estimates for freedom from thromboembolic events were obtained by Kaplan-Meier plots.nnnRESULTSnSixty-eight patients (16.4%) presented with endograft mural thrombus. Median follow-up time was 3.54 years (interquartile range, 1.99-5.47 years). In-graft mural thrombus was identified on 30-day CTA in 22 patients (32.4% of the study group), on 6-month CTA in 8 patients (11.8%), and on 1-year CTA in 17 patients (25%). Intraprosthetic thrombus progressively accumulated during the study period in 40 patients of the study group (55.8%). Overall, 17 patients (4.1%) presented with endograft or limb occlusions, 3 (4.4%) in the thrombus group and 14 (4.1%) in the control group (P = .89). Thirty-one patients (7.5%) received an aortouni-iliac (AUI) endograft. Two endograft occlusions were identified among AUI devices (6.5%; overall, 0.5%). None of these patients showed thrombotic deposits in the main body, nor were any outflow abnormalities identified on the immediately preceding CTA. Estimated freedom from thromboembolic events at 5 years was 95% in both groups (P = .97). Endograft thrombus accumulation was associated with >25% proximal aneurysm neck thrombus coverage at baseline (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.3), neck length ≤ 15 mm (OR, 2.4; 95% CI, 1.3-4.2), proximal neck diameter ≥ 30 mm (OR, 2.4; 95% CI, 1.3-4.6), AUI (OR, 2.2; 95% CI, 1.8-5.5), or polyester-covered stent grafts (OR, 4.0; 95% CI, 2.2-7.3) and with main component barrel-like configuration (OR, 6.9; 95% CI, 1.7-28.3).nnnCONCLUSIONSnMural thrombus formation within the main body of the endograft is related to different endograft configurations, main body geometry, and device fabric but appears to have no association with the occurrence of thromboembolic events over time.

Comparison of catecholamine hormone release in patients undergoing carotid artery stenting or carotid endarterectomy.

Purpose: To investigate the pattern of catecholamine response in patients undergoing carotid endarterectomy (CEA) or carotid artery stenting (CAS). Methods: Adrenaline, noradrenaline, and renin levels were measured at 5 time points in 12 patients undergoing 13 CEAs (1 bilateral) and 13 patients undergoing unilateral CAS. Arterial blood samples were taken at the following time points: (1) after induction in CEA patients or 5 minutes following first contrast injection in CAS patients, (2) 5 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, (3) 60 minutes following ICA clamp release in surgical patients or deflation of the balloon in the CAS cohort, and (4) 24 hours following the procedure. Intraoperative blood pressure and heart rate were recorded using radial arterial monitoring. Changes in adrenaline, noradrenaline, and renin levels are expressed as ratios versus baseline. Results: Patterns of adrenaline and noradrenaline release were significantly different in patients undergoing CAS and CEA, with much higher and more variable surges of adrenaline and noradrenaline occurring in CEA patients. Adrenaline and noradrenaline levels increased significantly over baseline following carotid artery clamping in patients undergoing CEA (noradrenaline ratio before clamping: 1.54±1.25, 24 hours after unclamping: 8.38±16.35 [p<0.001]; adrenaline ratio before clamping: 1.12±0.49, 60 minutes after unclamping: 17.59± 19.14 [p<0.001]). Conversely, in patients undergoing CAS, catecholamine levels remained unchanged (noradrenaline ratio before dilation: 0.96±0.23, 24 hours after the procedure: 0.92±0.32 [p = NS]; adrenaline ratio before dilation: 0.83±0.33, 60 minutes after balloon deflation: 0.56±0.32 [p = NS]). Conclusions: CAS is associated with a significantly less marked catecholamine response than CEA, which may reflect down-regulation of the sympathetic nervous system in response to carotid sinus stimulation during carotid angioplasty.

In Patients with Aortic Graft Infections, Does EVAR Improve Long Term Survival Compared to Open Graft Resection?

Primary and secondary aortic infections are uncommon but potentially lethal conditions. It remains uncertain what treatment strategy is best for these patients. This chapter provides an overview of the current literature on different treatment options for primary and secondary infected aortas. No randomized controlled trials have been published and the highest levels of evidence are systematic reviews, retrospective cohort studies and case series. Mortality rates for open and endovascular repair are high (20–50 %) and both show high reinfection rates (20 %). In aortic graft infections, endovascular repair is mostly studied for the treatment of aortoenteric fistulas and seems feasible as a bridge to open surgery or as a definite treatment. In-situ repair has a slightly better outcome in most studies when compared with other open treatment options. No studies compared open with endovascular treatment. Therefore, from the current literature, no recommendations can be made and the best approach should be to weigh the pros and cons of open and endovascular treatment for each individual patient.