AnaConDa Device Research Articles

Fenestrated Endovascular Aortic Repair of Complex Aneurysm Using the Anaconda Fenestrated Device: 1-Year Results From the French Multicenter Registry.

This study aims to assess the safety and efficacy of the fenestrated Anaconda device for the treatment of complex aortic aneurysms over 1 year in daily clinical practice. All patients who received the graft between October 2019 and October 2020 were prospectively enrolled in an observational, multicenter national registry. The primary endpoint was the aneurysm-related 1-year mortality rate. Secondary endpoints included all-cause mortality, technical success, device-related adverse events (AEs) and major complications, secondary reinterventions, endoleaks, target vessel (TV) outcomes, and a center-volume analysis comparing mortality and secondary reintervention rate between expert centers (>15 F/BEVAR per year) and nonexpert centers (≤15 F/BEVAR per year). Ninety-seven patients from 28 centers were treated. Aneurysms types included juxta-renal and short neck (84.6%), pararenal (5.2%), paravisceral (3.1%), and type IV thoracoabdominal (2.5%). Configurations with 1, 2, 3, and 4 fenestrations were used in 2, 12, 18, and 65 cases, respectively, totaling 350 TVs. Technical success was 98.0%, with 1 type Ic and 1 type IIIc endoleak. Mean follow-up was 468 days. Ten patients died, with 8 deaths (8.2%) due to non-aortic causes and 2 deaths (2.1%) from unknown causes. The estimated 1-year survival rate was 92.7% (95% CI: 87.8-98.1%). The reintervention rate at 30 days was 11.3% and the estimated reintervention rate at 1 year was 21.6% (95% CI: 12.7-29.6%). No type Ia endoleak occurred during follow-up. Three type III endoleaks occurred and required reintervention. Three TV occlusion occurred, yielding a 1-year TVI-free rate of 92.4% (95% CI: 89.4-99.3). No device-related major complication was recorded, and 3 device-related AEs occurred: 1 limb migration, 1 limb kinking and 1 limb thrombosis. There was no statistically significant difference in mortality and survival without reintervention between expert and nonexpert centers (Log rank p=0.52 and p=0.16, respectively). The fenestrated Anaconda device demonstrated acceptable early and at 1-year safety and efficacy for treating primarily juxta-renal and short-neck aortic aneurysms, in centers with varying levels of experience. The Anaconda Fenestrated, as the second commercially available custom-made device for complex endovascular aortic surgery, might adress some anatomical challenges. Following market authorization, this registry presents the 1-year outcomes of real-world device usage in a large number of centers, including small clinics. The results indicate that the device provided adequate efficacy and safety for treating mostly juxta-renal and short neck aneurysms, with notable improvement in technical success rate compared to older reports.

Technical Aspects and Outcome of Multi-Staged and Single-Staged Thoracoabdominal Fenestrated Endovascular Aortic Repair.

In some cases of endovascular thoracoabdominal or juxtarenal aortic aneurysm repair, a thoracic endograft in combination with a fenestrated renovisceral device may be needed in order to create a sufficient proximal landing zone. This study aimed to evaluate the technical aspects and postoperative morbidity of a single- or 2-stage approach. Eighty-seven consecutive patients undergoing thoracic endovascular aortic repair (TEVAR) in combination with elective fenestrated repair (fenestrated endovascular aortic repair [FEVAR]; fenestrated Anaconda device) from 2015 to 2022 were included in this retrospective bicentric study. Underlying pathologies, aortic morphology, technical details, and postoperative morbidity were recorded. Single-staged ("1S," n=61) and 2-staged ("2S," n=26) interventions were compared. Indications were thoracoabdominal aneurysms (TAAAs) (Crawford I-IV) (n=56, 64%) and juxtarenal aneurysms (n=31, 36%). In 2S, the proportion of TAAA was higher than in 1S (2S: 77%, 1S: 59%; p=0.001). In 2S, the covered length of the descending aorta was longer (1S: 128±60 mm, 2S: 202±64 mm; p=0.003). Temporary aneurysm sack perfusion (TASP) was established in 11 (18%) of 1S and 1 (4%) of 2S patients (p=0.079), as well as cerebrospinal fluid (CSF) drainage catheter in 48 (79%) of 1S and 19 (73%) of 2S. The rate of spinal cord ischemia (SCI) and the severity of SCI were not different in both groups, with a total of 3 cases of persisting paraplegia. The rate of access complications was higher in 2S (n=6, 23%) than in 1S (n=4, 7%; p=0.027). Postoperative 30 day morbidity did not significantly differ in both groups and neither did 30 day mortality (4.6% in 1S vs 3.8% in 2S; p=0.083). The combination of TEVAR and FEVAR using a fenestrated endograft is feasible and safe. Aortic morphology does not change significantly after endovascular repair. A single-staged strategy is feasible with excellent results, especially in Crawford IV, Crawford V, or juxtarenal aneurysms. Two-staged repair is recommended in cases with long aortic coverage and a higher American Society of Anesthesiologists (ASA) class. Follow-up data are needed to evaluate the long-term stability of the TEVAR/FEVAR interconnection. Our study has revealed the safety and efficacy of the combination of TEVAR and FEVAR in the treatment of TAAAs and juxtarenal aneurysms with compromised supravisceral landing zones. A single-staged concept is not necessary in all cases. Staged procedures may reduce postoperative morbidity in cases with long aortic coverage and higher ASA class.

Ultrasound Particle Image Velocimetry to Investigate Potential Hemodynamic Causes of Limb Thrombosis After Endovascular Aneurysm Repair With the Anaconda Device.

To identify potential hemodynamic predictors for limb thrombosis (LT) following endovascular aneurysm repair with the Anaconda endograft in a patient-specific phantom. A thin-walled flow phantom, based on a patient's aortic anatomy and treated with an Anaconda endograft, that presented with a left-sided LT was fabricated. Contrast-enhanced ultrasound particle image velocimetry was performed to quantify time-resolved velocity fields. Measurements were performed in the same phantom with and without the Anaconda endograft, to investigate the impact of the endograft on the local flow fields. Hemodynamic parameters, namely vector complexity (VC) and residence time (RT), were calculated for both iliac arteries. In both limbs, the vector fields were mostly unidirectional during the peak systolic and end-systolic velocity phases before and after endograft placement. Local vortical structures and complex flow fields were observed at the diastolic and transitional flow phases. The average VC was higher (0.11) in the phantom with endograft, compared to the phantom without endograft (0.05). Notably, in both left and right iliac arteries, the anterior wall regions corresponded to a 2- and 4-fold increase in VC in the phantom with endograft, respectively. RT simulations showed values of 1.3 to 6 seconds in the phantom without endograft. A higher RT (up to 25 seconds) was observed in the phantom with endograft, in which the left iliac artery, with LT in follow-up, showed 2 fluid stasis regions. This in vitro study shows that unfavorable hemodynamics were present mostly in the limb that thrombosed during follow-up, with the highest VC and longest RT. These parameters might be valuable in predicting the occurrence of LT in the future. This in-vitro study aimed to identify potential hemodynamic predictors for limb thrombosis following EVAR using ultrasound particle image velocimetry (echoPIV) technique. It was shown that unfavorable hemodynamic norms were present mostly in the thrombosed limb. Owing to the in-vivo feasibility of the echoPIV, future efforts should focus on the evaluation of these hemodynamic norms in clinical trials. Thereafter, using echoPIV as a bedside technique in hospitals becomes more promising. Performing echoPIV in pre-op phase may provide valuable insights for surgeons to enhance treatment planning. EchoPIV is also applicable for follow-up sessions to evaluate treatment progress and avoid/predict complications.

A01] Fractured Proximal Nitinol Ring in Fenestrated Anaconda Device: A Multicentre Case Series

A01] Fractured Proximal Nitinol Ring in Fenestrated Anaconda Device: A Multicentre Case Series

Mechanical Behaviour of Fenestrations in Current Aortic Endografts

The aim of this study was to assess the mechanical characteristics of current commercially available fenestrated endografts (FE). The performance of the fenestrations according to the design were compared as the relationship between a bridging covered stent graft (CSG) and the fenestration. A total of 21 Zenith (Cook Medical, Bloomington, IN, USA) and 17 Anaconda (Terumo Company, Inchinnan, UK) fenestrations were studied. Radial extension tests were performed, inserting two half cylinders spaced up to 2 mm in a 7 mm diameter fenestration from each device. Branch pull out force was measured to test the stability of the assembly with a calibrated 8 mm branch and two CSGs: Advanta V12 (Atrium Medical; Hudson, NH, USA) and BeGraft Peripheral Stent Graft (Bentley InnoMed GmbH, Hechingen, Germany). A branch was inserted in both the 7 mm diameter fenestrations and in a control 7 mm fenestration. Fatigue tests were performed on the devices to assess long term outcomes of the endograft. Over a 2 mm vertical displacement, the resulting loading curves look similar for both devices. The force value level was 33.4 ± 6.9 N for the Cook fenestration and 54.45 ± 18 N for the Anaconda fenestration (p= .001). With respect to an 8 mm calibrated branch, the required extraction strength from the fenestration was statistically significantly greater with the Anaconda device (9.5 ± 4.7 N vs. 4.49 ± 0.28 N; p= .001). The required strength to extract the V12 CSG from a control cylindered shape was statistically significantly higher than for the BeGraft CSG (6.75 ± 2.86 N vs. 1.83 ± 0.67 N; p= .003). The surface area of the fenestration of the Cook device was increased with cycling (7 200 cycles) compared with the Anaconda device (15.5% vs. 6.5% hole surface area increase). The mechanical performance of the fenestration can be fine tuned by considering its design. A CSG optimising the performance of the fenestration and the CGS-fenestration interface could reduce the risk of leakage in clinical practice.

Assessment of Pull-out Forces in TEVAR and ANACONDA FEVAR Combination and Early Clinical Results: Creation of a Proximal Landing Zone for FEVAR in Patients with Extent I and Extent IV TAAAs

Although recent data on the treatment of thoracoabdominal aortic aneurysms (TAAAs) are promising, in some cases, the paravisceral segment of the aorta may not be suitable for a branched endograft due to space restrictions. A combination of a fenestrated aneurysm repair (FEVAR) with a thoracic aneurysm repair (TEVAR) may represent a feasible treatment option. The current investigation was performed to assess the stability of a fenestrated Anaconda device implanted into a set of thoracic endografts from different manufacturers. We then assessed our clinical results with the FEVAR/TEVAR combination. Pull-out forces were measured invitro after docking a fenestrated Anaconda graft within the distal end of different TEVAR devices. Anaconda devices were implanted in 28- or 30-mm thoracic tube grafts (oversizing of at least 2mm: 13.3-21.4; minimum overlap of 15mm). Continuously increasing longitudinal pull forces of up to 100N were applied on an Instron Tensile Tester. Initial break point and damage to the endografts were documented. Clinical results of patients treated with such an FEVAR/TEVAR combination at our institution are presented as a second part of this study. Median pull-out forces ranged from 2.38N to 55.0N. The highest stability was achieved with 34-mm Anaconda devices in 28-mm thoracic tube grafts. Grafts with either thinner Dacron material or those featuring a polytetrafluorethylene membrane seemed especially vulnerable to punctures and tears caused by the downward-looking hooks of the Anaconda device. Between April 1, 2013 and December 31, 2018, in 28 of 172 patients treated with a fenestrated Anaconda device, prior implantation of a thoracic tube graft was necessary to create a sufficient proximal landing zone. In 25 cases (89.3%), the aneurysm was successfully treated. Although the 30-day reintervention rate in this subgroup was relatively high at 28.6%, none of these was due to a failure of the FEVAR/TEVAR combination. Upon an average follow-up of 15months, no failure of the graft connection and no type III endoleak due to membrane damage were observed. The combination of a thoracic tube graft and a fenestrated Anaconda device is a viable option for the treatment of patients with Extent I or IV TAAAs with no adequate landing zone above the celiac trunk. Although pull-out testing has shown good stability with most assessed grafts, the thoracic devices with thicker Dacron membranes seemed to be especially suitable.

Assessment of Pull-out Forces in TEVAR & ANACONDA FEVAR Combination and Early Clinical Results: Creation of a Proximal Landing Zone for FEVAR in Patients with Type I and Type IV TAAAs

Introduction: In certain cases of Type I thoracoabdominal aortic aneurysms (TAAA), endovascular treatment with off-the-shelf tube grafts is not feasible due to a lack of distal landing zone proximal to the celiac trunk. Likewise, the paravisceral segment of Type IV TAAAs is in certain cases not suitable for a branched endograft due to space restrictions. The creation of a proximal landing zone using a thoracic tube graft in combination with a distally implanted fenestrated Anaconda device may represent a feasible treatment option. The current investigation was performed to assess the stability of a fenestrated Anaconda device (FEVAR) implanted into a set of thoracic endografts from different manufacturers. We also evaluated our own clinical results with the TEVAR & FEVAR combination. Methods: The first part of the study was an experimental set-up. Pull-out forces were measured after docking the proximal end of an Anaconda graft within the distal end of a range of different TEVAR devices to assess the risk of migration and subsequent endoleak at the device interface. 30mm, 32mm and 34mm Anaconda devices were implanted in five different 28mm thoracic tube grafts (Cook Zenith, Medtronic Valiant, Jotec E-vita, Bolton Relay and Gore CTAG). The minimum overlap distance was 15mm. The device combination was mounted onto an Instron Tensile Tester and continuously increasing longitudinal pull forces of up to 100 Newton were applied. The initial break point and damage to the endografts were documented. For the second part of the study, a prospectively held database on FEVAR patients treated with the fenestrated Anaconda device at our institution was screened for cases where a suitable proximal landing zone had been created with a TEVAR device followed by aneurysm exclusion with a fenestrated device. Results: Median pull-out forces ranged from 1.05N to 55.0N. Pull-out forces were above 10.72N for all assessed combinations of grafts except for those including the 30mm Gore CTAG device and highest stability was achieved with 34mm Anaconda devices in 28mm thoracic tube grafts. While minor puncture holes caused by the downward-looking hooks of the Anaconda device were documented in all thoracic devices, the PTFE membrane of the Gore device and the Dacron material of the Jotec and Medtronic devices seemed especially vulnerable and fabric tears were observed. Between April 1st 2013 and December 31st 2018, in 28 out of 172 patients treated with a fenestrated Anaconda device, preliminary implantation of a thoracic tube graft was necessary to create a sufficient proximal landing zone. In 25 cases (89.3%), the aneurysm was successfully treated. Conclusion: The combination of a thoracic tube graft and a fenestrated Anaconda device is a viable option for the treatment of patients with Type I or IV TAAAs with no adequate landing zone above the celiac trunk. While pull-out testing has shown good stability with most assessed grafts, the Bolton and Cook thoracic devices seemed to be especially suitable. Disclosure: Jürgen Falkensammer & Afshin Assadian are have proctored fenestrated Anaconda implantations for Vascutek

Fractured Proximal Nitinol Ring in a Fenestrated Anaconda Device

Fractured Proximal Nitinol Ring in a Fenestrated Anaconda Device

Incidence and Treatment of Limb Occlusion of the Anaconda Endograft After Endovascular Aneurysm Repair

Purpose: To evaluate the incidence and treatment of limb occlusions of the second- and third-generation Anaconda endografts. Methods: A single-center retrospective study was conducted involving 317 consecutive patients (mean age 76 years; 289 men) who underwent endovascular aneurysm repair for elective asymptomatic, symptomatic intact, and ruptured infrarenal abdominal aortic aneurysm with 2 versions of the Anaconda device. From September 2003 to July 2011, the second-generation device was used in 189 patients (mean age 77 years; 169 men) and from July 2011 to September 2015, the third-generation device was implanted in 128 patients (mean age 75 years; 120 men). The rates of limb occlusion were compared between groups and according to compliance with the instructions for use (IFU); predictors were sought in multivariate analysis. The results of the latter are given as the hazard ratio (HR) and 95% confidence interval (CI). Results: Kaplan-Meier freedom of occlusion estimates for second- and third-generation devices, respectively, was 96.6% and 95.0% at 1 year, 89.9% and 95.0% at 2 years, and 86.5% and 88.6% at 5 years. There was no significant difference in overall occlusion rate between the second-generation devices (p=0.332) or with regard to use within the IFU (p=0.827); however, there was a clinically relevant decrease in the occlusion rate for elective patients treated with the third-generation device (6.4% vs 13.1%, p=0.077). There was an increase in the occlusion rate when the iliac limb diameter was ≤13 mm. In multivariate analysis, the only independent predictor of limb occlusion was a small distal prosthesis diameter (HR 0.732, 95% CI 0.63 to 0.86, p<0.001). Symptomatic nonruptured and ruptured abdominal aortic aneurysm (AAA) interventions had an almost 2-fold increased risk of occlusion (HR 1.95, 95% CI 0.93 to 4.11, p=0.078), though this did not reach statistical significance. Conclusion: The Anaconda design has proven effectiveness in AAA exclusion in daily practice inside the IFU. However, efforts could be made to further reduce the limb occlusion rate.

Operative and 1-Year Outcomes of the Custom-Made Fenestrated Anaconda Aortic Stent Graft—A UK Multicenter Study

Early and 1-year outcomes are presented for fenestrated endovascular aneurysm repair (FEVAR) of complex aortic aneurysmal disease with the custom-made Anaconda fenestrated stent graft in 101 patients. Retrospective site-reported data from the first 101 elective cases (2010-2014) from 4 UK centers were studied to evaluate patient demographics, aneurysm morphology, clinical success, and 1-year outcomes in patients undergoing fenestrated aneurysm repair with the custom-made Anaconda device. 101 fenestrated grafts (median age 76, 85% male) were implanted with a total of 255 fenestrations (196 renal arteries, 48 superior mesenteric artery, and 11 celiac arteries) with 3% mortality, 98.4% target vessel patency (TVP) at 30day follow-up. Although 15 type I or III endoleaks were demonstrated at completion angiography, all 10 type Ia endoleaks resolved spontaneously. Survival by Kaplan-Meier analysis was 97% and 91% at 1 month and 1 year, respectively; with 75.8% showing reduction in abdominal aortic aneurysm diameter and only 1 patient with sac expansion. Freedom from loss of TVP was 97.6%. Custom-made fenestrated Anaconda devices demonstrate low procedural mortality and a high rate of technical and clinical success at 30days and 1 year.

Rescue of failed endovascular aortic aneurysm repair using the fenestrated Anaconda device

ObjectiveEndovascular aortic aneurysm repair (EVAR) with a fenestrated device (FEVAR) allows an extension of the proximal sealing zone above the renal arteries to an adequate, healthier segment of the aorta. This feature makes FEVAR an option to treat patients with a diseased aortic neck or type Ia endoleak after EVAR. The aim of this investigation was to present a single-center experience with FEVAR for patients with an abdominal aortic endograft in situ compared with primary FEVAR. MethodsA prospectively held database on FEVAR patients treated with the fenestrated Anaconda device (Vascutek/Terumo, Inchinnan, Scotland, United Kingdom) at our institution was screened for individuals who had previously undergone EVAR. ResultsBetween April 1, 2013, and July 31, 2016, 94 fenestrated Anaconda devices were implanted at our institution. Twelve patients with prior EVAR were treated for pathology of the proximal neck: type I endoleak (n = 7), for stent migration with aneurysm progression but no visible endoleak (n = 2), and progressive aortic disease at the level of the visceral segment (n = 3). When redo cases and primary FEVARs were compared, primary technical success rates were 58.3% and 87.8% (P = .02) and primary functional success rates were 91.7% and 95.1%, respectively (P = .62). Perioperative rate of major deployment-related (14.6% and 16.7%) and systemic complications (8.5% and 8.3%) as well as 30-day mortality (6.1% and 0%; P = .5) were comparable between groups. After an average follow-up interval of 10 months (range, 0-43 months), no late occlusions of connecting stents were observed. The late reintervention rates were 11.0% and 16.7%, respectively (P = .57). ConclusionsThe risk of a failure to cannulate one or more visceral arteries through the respective fenestrations was increased in patients who had previously undergone EVAR. This is most likely caused by increased friction between the fenestrated endograft and the failing graft in situ, which may impair the adaption of the unsupported Anaconda device to the aortic wall. As a consequence, fenestrations may not line up perfectly at the respective openings of the visceral or renal arteries, and folding of the fabric may be increased, making cannulation of the fenestrations more difficult.

Operative and Midterm Outcomes of the Fenestrated Anaconda Stent-Graft in the Endovascular Treatment of Juxtarenal, Suprarenal, and Type IV Thoracoabdominal Aortic Aneurysms

Purpose: To report operative and midterm outcomes of fenestrated endovascular aneurysm repair (FEVAR) with the Anaconda device. Methods: A retrospective analysis was conducted of 39 consecutive patients (median age 74 years; 36 men) treated with the fenestrated Anaconda stent-graft between July 2011 and December 2015 at a single center. Indications for FEVAR were abdominal aortic aneurysms (AAAs) with neck anatomy unsuitable for a standard stent-graft. Median infrarenal neck length was 4 mm (range 0–9). Four (10%) patients presented with type IV thoracoabdominal aortic aneurysm (TAAA), 12 (31%) with suprarenal aneurysms, and 23 (59%) with juxtarenal aneurysms. Four (10%) patients had previous infrarenal aortic repair. Five (13%) patients had an infrarenal neck angulation >60°. A total of 106 fenestrations were incorporated into the stent-grafts (73 renal arteries, 25 superior mesenteric arteries, and 8 celiac trunks). Technical success, perioperative and midterm mortality and morbidity, target vessel patency, endoleaks, and reinterventions were documented. Results: Technical success was 95% (37/39). Three (8%) patients died in-hospital from mesenteric embolism in 2 and renal artery rupture with consequent multiorgan failure in 1. Two (5%) patients suffered an intraoperative embolic stroke. During a median follow-up of 33 months (range 4–55), adjunctive maneuvers were performed in 9 (23%) patients, including reintervention for type II endoleak with enlarged aneurysm sac in 2 (5%). Four additional patients died of causes unrelated to the aortic pathology (overall mortality 18%). In 34 (94%) of the 36 patients seen in follow-up, aneurysm sac size was stable or decreased. Target vessel stent patency was 99% (95/96). Conclusion: FEVAR with the Anaconda device delivers satisfactory short-term technical and clinical success rates in patients with juxtarenal, suprarenal, and type IV TAAA. Midterm efficacy and durability with respect to aneurysm sac regression and target vessel patency appear very good. Overall mortality and the need for reintervention were significant in this patient cohort.

Structural implications of fenestrated stent graft misalignment

BackgroundEndovascular aneurysm repair is a minimally-invasive method for the treatment of abdominal aortic aneurysms. For aneurysms that involve the visceral arteries, a custom-made stent graft with fenestrations for the branch arteries is required. The purpose of the current study is to evaluate the structural impact of misaligned fenestrations with respect to luminal patency and proximal aortic neck apposition in an in vitro model. MethodsA custom apparatus was used to evaluate seven Anaconda and three Zenith fenestrated stent grafts. All stent grafts were evaluated at 10° increments of stent/fenestration misalignment up to 80°. Images were captured at each interval and the luminal cross-sectional area and wall apposition were measured. ResultsThe Anaconda stent graft, which has an unsupported main body, demonstrated a linear reduction in luminal patency at increasing angles of misalignment (P < 0.0001). Stent/fenestration misalignments of 20° and 80° resulted in decreases in mean luminal patency of 14% and 54% respectively. The Zenith stent graft demonstrated a similar decrease in luminal patency, starting at misalignments of ≥40° (P < 0.0001). However, with stent/fenestration misalignments of ≥30°, apposition between the Zenith stent graft and the simulated aortic neck was compromised suggesting the creation of a type Ia endoleak. ConclusionsBoth the Anaconda and Zenith devices behave adversely at extreme angles of misalignment with luminal narrowing in the Anaconda device and loss of wall apposition in the Zenith device; however, both stent grafts appear to be equivalent at low angles of misalignment.

Determination of a sevoflurane dosing formula for AnaConDa device in children

Determination of a sevoflurane dosing formula for AnaConDa device in children

The scavenging of volatile anesthetic agents in the cardiovascular intensive care unit environment: a technical report

The use of volatile-based sedation within critical care environments has been limited by difficulties of drug administration and safety concerns over environment pollution and staff exposure in an intensive care unit (ICU) with no scavenging. The aim of this study was to develop a simple scavenging system to be used with the Anesthesia Conserving Device (AnaConDa(®)) and to determine whether or not ambient concentrations of residual anesthetic are within current acceptable limits. The scavenging system consists of two Deltasorb(®) canisters attached to the ICU ventilator in series. AnaConDa is a miniature vaporizer designed to provide volatile-based sedation within an ICU. The first ten patients recruited into a larger randomized trial assessing outcomes after elective coronary graft bypass surgery were sedated within the cardiac ICU using either isoflurane or sevoflurane. Sedation was guided by the Sedation Agitation Scale, resulting in an end-tidal minimum anesthetic concentration of volatile agent ranging from 0.1-0.3. At one hour post ICU admission, infrared photometric analysis was used to assess environmental contamination at four points along the ventilator circuit and scavenging system and around the patient's head. All measurements taken within the patient's room were below 1 part per million, which satisfies criteria for occupational exposure. This study shows that volatile agents can be administered safely within critical care settings using a simple scavenging system. Our scavenging system used in conjunction with the AnaConDa device reduced the concentration of environmental contamination to a level that is acceptable to Canadian standards and standards in most Western countries and thus conforms to international safety standards. The related clinical trial was registered at www.clinicaltrials.gov (NCT01151254).

Early clinical experience with the Anaconda re-deployable endograft in 106 patients with abdominal aortic aneurism: the west of Scotland Anaconda registry

Endovascular repair of abdominal aortic aneurysm is a common procedure and not without complications. The aim of this study was to evaluate the early results of the Anaconda endograft (Vascutek Ltd., Inchinnan, Scotland, UK) in 106 patients in three hospitals in the west of Scotland. A prospective registry of 106 consecutive patients undergoing endoluminal repair of their abdominal aortic aneurysms using the Anaconda device was set up to record the clinical outcomes, with a mean follow-up of two years. There was no 30-day perioperative mortality in the 106 patients. Only type II endoleaks were detected on serial computed tomography scanning at follow-up. Technical success was achieved in 99% (105/106) in this study; one patient was converted to open surgical repair. Two cases of proximal device migration (>1 cm) were detected at one month and 19 months, respectively, with no associated endoleak or sac enlargement. Five cases of endograft limb thrombosis were noted in this study. Our early clinical experience with the Anaconda endograft compares favourably with other commercially available endografts in the treatment of abdominal aortic aneurysms. The main advantages of this device are that it is re-deployable and that it has a magnetic wire system which makes it easy to implant.

A review of the practice of sedation with inhalational anaesthetics in the intensive care unit with the AnaConDa® device

The intensive care unit (ICU) environment is often perceived to be hostile and frightening by patients due to unfamiliar surroundings coupled with presence of numerous personnel, monitors and other equipments as well as a loss of perception of time. Mechanical ventilation and multiple painful procedures that often need to be carried out in these critically ill patients add to their overall anxiety. Sedation is therefore required not only to allay the stress and anxiety, but also to allow for mechanical ventilation and other invasive therapeutic and diagnostic procedures to be performed. The conventional intravenous sedative agents used in ICUs suffer from problems of over sedation, tachyphylaxis, drug accumulation, organ specific elimination and often lead to patient agitation on withdrawal. All this tend to prolong the ventilatory as well as ICU and hospital discharge time, which increase the risk for infection and add to the overall increase in morbidity, mortality and hospital costs. In 2005, the anaesthetic conserving device (AnaConDa®) was marketed for ICU sedation with volatile anaesthetic agents. A number of trials have shown the effectiveness of using volatile anaesthetic agents for ICU sedation with the AnaConDa device. Compared with intravenous sedatives, use of volatile anaesthetic agents have resulted in shorter wake up and extubation time, lesser duration of mechanical ventilation and faster discharge from hospitals. This review shall focus on the benefits, technical pre-requisites and status of sedation with volatile anaesthetic agents in ICUs with the AnaConDa® device.

Decreased Nitric Oxide Concentration When Used in Conjunction with the AnaConDa Device

To the Editor The Anaesthetic Conserving Device AnaConDa© (ACD) (Sedana Medical, Uppsala, Sweden) is a small vaporizer inserted into a ventilator circuit that allows vaporization of liquid sevoflurane from a syringe pump, and has been used to deliver volatile anesthetics for sedation of patients in the intensive care unit.1 We recently cared for such a patient receiving inhaled nitric oxide (NO), the concentration of which appeared to be altered by the ACD. A 64-year-old man, with severe chronic obstructive pulmonary disease and hypertension, underwent both aortic and mitral valve replacement. Permission was obtained from the patient for this report. Postoperatively, severe pulmonary hypertension and right ventricular failure required treatment with levosimendan, dobutamine, epinephrine, and inhaled NO at 16 ppm. NO concentrations were monitored using the NOxBOX© (Bedfont Medical, Kent, England). The patient later developed pneumonia and acute respiratory distress syndrome with increasing hypoxia, and the method of sedation was changed from intermittent midazolam to sevoflurane administered via the ACD. While aiming for Bispectral Index values between 60 to 70, an end-tidal concentration of sevoflurane between 0.5% and 0.7% was accompanied by a decrease in the hemoglobin oxygen saturation (SpO2) from 96% to 91%. The NO concentration measured at 2 sites in the system both before and after using the ACD revealed a 50% decrease in the concentration measured after using the ACD. Changing the site of NO delivery into the breathing system after rather than before using the ACD resulted in an increased inspired NO concentration to 16 ppm and an increased SpO2 of 98%. We hypothesize that the decreased SpO2 was related to decreased inhaled NO concentration caused by absorption of NO in the carbon-activated filter of the ACD.2–4 Jose Luis Guerrero Orriach Manuel Galan Ortega Manuel Rubio Navarro Jose Cruz Manñas Anesthesia Department Hospital Virgen de la Victoria Malaga, Spain [email protected]

Anaconda AAA Bifurcated Endovascular Graft Migration: Customised Aortouniiliac Endograft Conversion

We report a case of a 58-year-old-man with a 55-mm infrarenal aortic aneurysm treated with an Anaconda™ modular endograft. An error during a delivery-system pull-back manoeuvre caused the migration of the endograft. This was resolved with an aorto-uniiliac conversion and a femoro-femoral crossover bypass. Since a ready-made aorto-uniiliac system was not available, we customised one using a new Anaconda device, squeezing the contralateral gate and occluding this limb with coils.

Active Gas Scavenging is Unnecessary When Using the AnaConDa Volatile Agent Delivery System

The AnaConDa filter system has been used in intensive care units (ICUs) to deliver low concentrations of volatile anaesthetic agents to treat severe airflow obstruction and for sedation. The manufacturer and a recently published review recommend the use of a scavenging system with the device. It is unclear from the literature what levels of volatile agent staff are exposed to when the device is being used in ICU without a scavenger. We carried out an observational study requested by the local occupational health department to measure the levels of ICU staff exposure to isoflurane when the AnaConDa delivery system was used to treat asthma. This study was carried out using an ambient air analyser while the patient was receiving therapeutic levels of isoflurane via the AnaConDa device. We conclude that gas scavenging may not be necessary when using the AnaConDa device to deliver therapeutic doses of isoflurane.