Real world experience with the TREO device in standard EVAR: Mid-term results of 150 cases from a German Multicenter study.

Background: The objective of the study was to analyze mid-term results of unselected patients treated with the TREO (Terumo Aortic, Florida, USA) device at six German hospital sites. Methods: A multicenter, retrospective analysis of patients treated within and outside instructions for use (IFU) from January 2017 to November 2020 was performed. Primary outcomes were technical success, mortality and endograft related complications according to IFU status. Secondary outcomes were aneurysm/procedure related re-interventions. Results: 150 patients (92% male, mean age 73 ±8 years) were treated (within IFU 84% vs. outside IFU 16%) with the TREO device for abdominal aortic aneurysms (n=127 intact, n=17 symptomatic and n=6 ruptured; p=0.30). Technical success was achieved in 147/150 (within IFU 99% vs. outside IFU 92%, p=0.08). 30-day mortality was 2%, one year and overall mortality was 3% and 5%. During a mean follow-up of 28.4 months (range: 1-67.4 months), 35 (25%; within IFU 23% vs. outside IFU 35%, p=0.23) patients suffered from endoleaks. The majority were endoleaks type II (n=33), the remaining type Ia (n=5) and type Ib (n=3). No endoleaks type III-V, migrations or aneurysm ruptures occurred. Overall, 19 patients (13%; within IFU 13% vs. 15% outside IFU, p=0.70) received a secondary intervention: nine endoleak related endovascular procedures, three open conversions, two endograft limb related interventions, four surgical revisions of the femoral access sites and two bowl ischemia related procedures, respectively. Conclusions: This non industry-sponsored, multicenter trial indicates that using the TREO device in a real-world setting (both within and outside IFU) seems feasible in the treatment of patients suffering from AAA. While the rate of complications and secondary interventions is in line with previously published data, the findings highlight the fact that standard EVAR is associated with serious adverse events.

Covered Endovascular Reconstruction of the Iliac Artery Bifurcation (CERIB).

PURPOSE: The aim of this study was to present the covered endovascular reconstruction of the iliac artery bifurcation (CERIB) technique as a revascularization option for aorto-iliac occlusive disease (AIOD) involving the iliac artery bifurcation. METHODS: This was a retrospective single-center study including all patients undergoing a CERIB procedure from January 2021 until December 2022. Covered endovascular reconstruction of the iliac artery bifurcation procedures were performed percutaneously with bilateral femoral access, excepting cases where simultaneous open femoral artery reconstruction was required due to the extension of peripheral arterial occlusive disease. Standard patient, procedural, and follow-up (FU) data including survival and arterial reinterventions were gathered and analyzed. RESULTS: A total of 13 patients were included (11/13 male, median age=70 [60-76] years). Additional open and/or endovascular procedures included endarterectomy of the femoral bifurcation (n=6), rotational atherectomy (n=2), and 1 axillary artery cutdown for upper limb access (n=1). Median operating time was 2.9 hours (1.5-4.9 hours); median radiation duration and dose were 28.4 (14.3-63.3 minutes) and 4090.6 (384.4-9430.1 cGray/cm2), respectively. The stent grafts used for CERIB were BeGraft peripheral n=31, BeGraft Aortic n=4 and BeGraft peripheral plus n=1 (Bentley InnoMed GmbH, Hechingen, Germany). In 2 patients with prior stenting of the common iliac artery (CIA), only the internal and external iliac arteries (IIA and EIA) were treated in this study, and in 2 cases, additional uncovered stents were required for relining. Technical success was 100%. During a midterm FU (median 18 [4-31] months), 2 patients died from cardiovascular reasons and 1 patient with prior iliac stenting required reinterventions for recurring occlusion. CONCLUSION: Covered endovascular reconstruction of the iliac artery bifurcation is a straightforward option for treating AIOD involving the iliac artery bifurcation that allows preservation of internal iliac artery perfusion and shows good early and midterm results. Prior iliac artery stenting may be a risk factor for early occlusion after CERIB. CLINICAL IMPACT: Aorto-iliac occlusive disease with involvement of the internal iliac artery is encountered regularly in vascular surgical practice, but the internal iliac artery is often not included in the revascularization strategy. The present article will increase the awareness for the relevance of including the internal iliac artery in revascularization strategies and presents CERIB as another method to be added to the armamentarium of (endo-)vascular surgeons and interventionalists.

Rendezvous intervention using combined surgical carotid endarterectomy followed by endovascular thrombectomy in patients with acute tandem occlusions: a proof-of-concept experience at a tertiary care center.

BACKGROUND: Endovascular thrombectomy (EVT) is highly effective in acute stroke patients with intracranial large vessel occlusion (LVO), however, presence of concomitant cervical occlusion of the internal carotid artery (ICA) may limit the endovascular access. This study describes feasibility and efficacy of a surgical carotid access (cutdown) to perform interdisciplinary recanalization therapy including carotid endarterectomy (CEA) followed by EVT for recanalization of intracranial LVO in stroke patients with tandem occlusions. METHODS: We identified stroke patients with tandem occlusions who underwent a combined surgical-endovascular approach over a 5-year period. Surgical cutdown was provided by a cardiovascular surgery team at the angio-suite followed by EVT performed by the neuroradiological team. Demographics, stroke characteristics, treatments including antithrombotic management, procedure times, and clinical follow-up were assessed. RESULTS: Four patients with acute stroke because of tandem occlusions received CEA followed by EVT (two patients after frustrating femoral catheterization, two as first-line approach). Successful recanalization (TICI ≥ 2b) via endovascular thrombectomy was achieved in all patients at a median of 28 min after successful surgical CEA. Intraprocedural complication was observed in one case (25%; i.e. ICA dissection). CONCLUSIONS: This small study provides evidence that a combined interdisciplinary approach of CEA followed by EVT in the angio-suite in acute stroke patients with tandem occlusions is a feasible procedure in patients otherwise not accessible to endovascular recanalizing therapy and, therefore, high likelihood of developing large hemispheric infarction. Prospective data are warranted to identify patients who benefit from this combined approach as first-line therapy.

[Acute mesenteric ischemia-An overview and recommendations (S2k analogous) of the World Society of Emergency Surgery]. / Die akute Mesenterialischämie ­ eine Übersicht und Empfehlungen (S2k-analog) der World Society of Emergency Surgery.

Acute mesenteric ischemia is a severe illness, which if untreated, rapidly leads to a critical condition with sepsis, multiple organ failure and death in affected patients. The diagnosis and initiation of treatment of acute mesenteric ischemia should be performed as early and expeditiously as possible and follows the principle of the shortest possible time to reperfusion. Otherwise, the outcome of the patient rapidly deteriorates. The treatment algorithm should be adapted to the pathogenesis of the ischemia, the clinical condition and symptoms of the patients. With clinical signs of peritonitis, intestinal gangrene must be assumed and the abdomen should be surgically explored to detect and treat possible foci of sepsis at an early stage. The treatment of acute mesenteric ischemia should always be performed by an interdisciplinary team with all surgical and interventional options for intestinal revascularization as well as comprehensive intensive care medicine according to the standards of the Intestinal Stroke Center described in the literature. A short duration to revascularization and treatment in this interdisciplinary concept improves the outcome of patients with acute mesenteric ischemia. The World Society of Emergency Surgery provides expert consensus-based recommendations for the diagnosis and treatment of acute mesenteric ischemia; however, there is still a significant lack of broad high-quality evidence for this critical illness. Recommendations of the German specialist societies are urgently needed to ensure appropriate care, from the initial diagnostics to treatment and aftercare, for patients with suspected mesenteric ischemia in this country.

Infrarenal Remains Infrarenal-EVAR Suitability of Small AAA Is Rarely Compromised despite Morphological Changes during Surveillance.

The aim was to analyze small abdominal aortic aneurysm (AAA) morphology during surveillance with regard to standard endovascular aortic repair (EVAR) suitability. This retrospective single-center study included all patients (n = 52, 48 male, 70 ± 8 years) with asymptomatic AAA ≤ 5.4 cm undergoing ≥2 computed tomography angiography(CTA)/magnetic resonance imaging (MRI) studies (interval: ≥6 months) between 2010 and 2018. Aneurysm diameter, neck quality (shape, length, angulation, thrombus/calcification), aneurysm thrombus, and distal landing zone diameters were compared between first and last CTA/MRI. Resulting treatment plan changes were determined. Neck shortening occurred in 25 AAA (mean rate: 2.0 ± 4.2 mm/year). Neck thrombus, present in 31 patients initially, increased in 16. Average AAA diameters were 47.7 ± 9.3 mm and 56.3 ± 11.6 mm on first and last CTA/MRI, mean aneurysm growth rate was 4.2 mm/year. Aneurysm thrombus was present in 46 patients primarily, increasing in 32. Neck thrombus growth and neck length change, aneurysm thrombus amount and aneurysm growth and aneurysm growth and neck angulation were significantly correlated. A total of 46 (88%) patients underwent open (12/46) or endovascular (34/46) surgery. The planned procedure changed from EVAR to fenestrated EVAR in two patients and from double to triple fenestrated EVAR in one. Thus, standard EVAR suitability was predominantly maintained as the threshold diameter for surgery was reached despite morphological changes. Consecutively, a possibly different pathogenesis of infra- versus suprarenal AAA merits further investigation.

First-in-Human Clinical Application of the Medyria TrackCath System in Endovascular Repair of Complex Aortic Aneurysms (ACCESS Trial): A Prospective Multicenter Single-Arm Clinical Trial.

PURPOSE: The Medyria TrackCath Catheter (MedTCC) is an innovative, thermal convection-based blood flow velocity (BFV) tracking catheter that may be used during complex aortic endovascular procedures for identification and catheterization of target orifices. The ACCESS Trial analyzes the safety and performance of the MedTCC for targeted vessel catheterization to generally evaluate the feasibility of thermal convection-based BFV. MATERIALS AND METHODS: We performed a first-in-human, proof-of-concept, prospective single-arm multicenter clinical trial between March 2018 and February 2019 in patients who underwent endovascular aortic procedures at 4 high-volume centers. During these procedures, the MedTCC was advanced over a guidewire through the femoral access. The D-shape was enfolded in the reno-visceral part of the aorta and target orifices were identified and catheterized with a guidewire via the side port of the MedTCC through BFV tracking. BFV measurements were performed at baseline (Baseline-BFV), alignment to the orifice (Orifice-BFV), and following catheterization (Confirmation-BFV) to prove correct identification and catheterization of target orifices. The procedural success rate, the catheterization success rate, procedure-related parameters, and (serious) adverse events ((S)AE) during the follow-up were analyzed. RESULTS: A total of 38 patients were included in the safety group (SG) and 26 in the performance group (PG). The procedural success rate was 89% (PG), the MedTCC catheterization success rate was 98% (PG). The MedTCC reliably measured BFV changes indicated by significant differences in BFV between Baseline-BFV and Orifice-BFV (p<0.05). Median (interquartile range; IQR) fluoroscopy time per orifice was 5.0 (1.5-8.5) minutes [total surgery 49 (26-74) minutes], median (IQR) contrast agent used per orifice was 1.0 (0-5.0) mL [total surgery 80 (40-100) mL], and median (IQR) MedTCC-based procedural time was 3.0 (2.0-6.0) minutes. There was no device-related SAE. CONCLUSIONS: The ACCESS Trial suggests that BFV measurement allows for reliable target orifice identification and catheterization. The use of MedTCC is safe and generates short fluoroscopy time and low contrast agent use, which in turn might facilitate complex endovascular procedures.

Xenogeneic materials for the surgical treatment of aortic infections.

BACKGROUND: The surgical treatment of aortic infections (AIs) is challenging. In situ aortic reconstructions represent nowadays the favored therapy for fit patients and xenogeneic materials are used increasingly. The aim of this study was to present our experience with xenogeneic reconstructions for AI using self-made bovine pericardium tubes and/or the biosynthetic Omniflow® II graft. METHODS: This retrospective single-center study included all patients undergoing xenogeneic aortic and aortoiliac reconstructions from December 2015 to June 2020. Patient comorbidities, symptoms, procedural characteristics, types of pathogens and postoperative outcomes were analyzed. RESULTS: Twenty-eight patients [23 male (82%), median age 68 (range, 28-84) years] were included. Ten patients (36%) had native AIs and 18 (64%) had graft infections, including 3 (11%) aortoesophageal and 2 (7%) aortoduodenal fistulas (ADF). Twenty-four patients (86%) were symptomatic, the most common symptoms being contained aortic rupture (n=8) and sepsis (n=4). The surgical procedures were infra- and juxtarenal aortic repairs (n=11, 39% and n=7, 25%), thoracoabdominal aortic repairs (type IV: n=1, 4%; type V: n=3, 11%), descending thoracic aortic repairs (n=4, 14%) and 2 reconstructions (7%) involving the ascending aorta/aortic arch. Most were urgent (n=10, 43%) or emergent operations (n=11, 35%). Identification of pathogen(s), mostly Gram-positive bacteria, was possible in 25 patients (89%). Twelve patients (43%) had polymicrobial infections and 6 (21%) infections with multi-resistant bacteria. In-hospital mortality was 32% (n=9) due to acute cardiac failure (1/9), endocarditis (1/9), bleeding (3/9) and sepsis (4/9). The most frequent complications were transient need for dialysis (n=12, 43%) and persisting sepsis (n=11, 39%). Two early occlusions of Omniflow® II grafts were observed (7%). Median follow-up (FU), during which 2 patients died of non-aortic causes, was 14 months (95% CI: 9-19 months). Freedom from reoperation was 100%, there was no evidence for reinfection during FU. CONCLUSIONS: Xenogeneic orthotopic reconstructions for AI can be performed at all aortic levels. Combining bovine pericardium and the Omniflow® II graft can be useful for reconstructing the branched aortic segments and both materials show appropriate early to midterm outcomes. Nonetheless, AIs are serious conditions associated with relevant morbidity/mortality rates, even in a specialized center.

Changes in Target Vessel Anatomy Following Fenestrated Endovascular Aneurysm Repair: Midterm Results.

Purpose: To analyze the changes in target vessel (TV) anatomy after fenestrated endovascular aneurysm repair (fEVAR) during midterm follow-up. Materials and Methods: A retrospective single-center study analyzed 56 patients (mean age 71±7 years; 49 men) who underwent fEVAR using custom-made stent-grafts (22 Zenith and 34 Anaconda) between June 2010 and July 2016. Advanta V12 (V12; 74, 53%) and BeGraft (BeG; 66, 47%) stent-grafts were used to bridge to the 140 TVs. Measurements of the TV deviation at the aortic origin, the vessel shift distal to the bridging stent-graft (BSG), and the outer and inner BSG curve lengths were performed after 3-dimensional reconstruction of the serial computed tomography angiography scans. The results of the measurements for the main devices, the TVs, and the bridging stent-grafts were compared using univariable and multivariable analysis. Results: Of the 140 BSGs examined (74 V12s and 66 BeGs), 393 measurements (38 celiac trunks, 102 superior mesenteric arteries, 121 left renal arteries, and 132 right renal arteries) were analyzed. The outer/inner BSG curve length ratio was larger after implantation of Zenith devices compared with Anaconda (p<0.001). The vessel shift distal to the BSG was significantly associated with the interaction of the TV and type of BSG only in the univariable analysis (p=0.001). There were no significant changes of the TV deviation at the aortic origin. Only the outer BSG curve length was significantly associated with TV complications (p=0.033). Median follow-up was 24 months (range 2-61). The BSG curve length ratio showed a significant increase over time (p<0.001) but did not differ between the BeG and V12 (p=0.381). Conclusion: No difference was found between the V12 and the BeG stent-grafts regarding anatomical TV changes during midterm follow-up after fEVAR. Both stent-grafts adapt to the TV anatomy over time, and moderate anatomical changes seem to be tolerated without increasing the risk for TV complications. The type of main device also influences the TV anatomy.

Patients with degenerative cervical myelopathy have signs of blood spinal cord barrier disruption, and its magnitude correlates with myelopathy severity: a prospective comparative cohort study.

PURPOSE: The aim of this study is to detect the presence of blood spinal cord barrier (BSCB) disruption in patients with degenerative cervical myelopathy (DCM). METHODS: In this prospective non-randomized controlled cohort study, 28 patients with DCM were prospectively included. All patients had indication for neurosurgical decompression. Furthermore, 38 controls with thoracic abdominal aortic aneurysm (TAAA) and indication for surgery were included. All patients underwent neurological examination. Regarding BSCB disruption and intrathecal immunoglobulin (Ig) concentrations, cerebrospinal fluid (CSF) and blood serum were examined for albumin, IgG, IgA and IgM. Quotients (Q) (CSF/serum) were standardized and calculated according to Reibers' diagnostic criteria. RESULTS: Patients and controls distinguished significantly in their clinical status. AlbuminQ, as expression of BSCB disruption, was significantly increased in the DCM patients compared to the controls. Quotients of IgG and IgA differed significantly between the groups as an expression of intrathecal diffusion. In the subgroup analysis of patients with mild/moderate clinical status of myelopathy and patients with severe clinical status, the disruption of the BSCB was significantly increased with clinical severity. Likewise, IgAQ and IgGQ presented increased quotients related to the clinical severity of myelopathy. CONCLUSION: In this study, we detected an increased permeability and disruption of the BSCB in DCM patients. The severity of BSCB disruption and the diffusion of Ig are related to the clinical status in our patient cohort. Having documented this particular pathomechanism in patients with DCM, we suggest that this diagnostic tool cloud be an important addition to surgical decision making in the future. These slides can be retrieved under Electronic Supplementary Material.

Intraoperative contrast-enhanced ultrasound examination for endoleak detection after complex and infrarenal endovascular aortic repair.

OBJECTIVE: The aim of this pilot study was to evaluate intraoperative contrast-enhanced ultrasound (iCEUS) examination for endoleak (EL) detection after complex endovascular aortic repairs (EVAR) in comparison with the standard angiographic completion control. METHODS: Twenty-one patients (16 male; median age, 73 years [range, 54-81 years]) who underwent single-stage EVARs at our center between October 2016 and October 2018 were included prospectively. The procedures comprised fenestrated and/or branched EVAR (n = 14; 66%), infrarenal EVAR (n = 5; 24%), infrarenal EVAR with bilateral iliac side branch implantation (n = 1; 5%), and infrarenal EVAR with occluder implantation into the internal iliac artery (n = 1; 5%). The used endografts included 14 custom made devices (Cook, Australia Pty Ltd, Brisbane, Australia, n = 6; Vascutek Terumo, Glasgow, Scotland, n = 8) and seven standard infrarenal endografts (Medtronic Inc, Santa Rosa, Calif, n = 5; Vascutek Terumo, Glasgow, Scotland, n = 1; Cook, n = 1). All patients underwent an angiographic completion control for EL detection followed by iCEUS examination. The iCEUS examination was performed by the same examiner who was blinded to the angiography result. In addition to the comparison of the angiographic results to iCEUS examination, iCEUS examination was also compared with the computed tomography angiography (CTA) before discharge (median time to CTA, 5 days [range, 1-7 days]). RESULTS: Angiography detected eight type II EL, defining the EL origin in four cases. In addition to detecting all of those eight EL, iCEUS examination revealed eight more type II EL not seen on angiography (P = .002) and allowed a definition of the EL origin in all cases. CTA before discharge showed a persistence of only 5 of the 16 type II EL detected by iCEUS examination (31%, P = .002). CONCLUSIONS: An iCEUS examination can be used as another adjunct to decrease exposure to contrast agent and radiation during EVAR, including complex procedures. A replacement of the completion angiography by iCEUS examination is conceivable for infrarenal EVAR, but also for endovascular type IV or type V repairs. Future studies with larger patient numbers will help to further validate iCEUS examination during complex EVAR.

Management strategies for true and dissecting visceral artery aneurysms.

BACKGROUND: Visceral artery aneurysms (VAA) are rare and the literature regarding management strategies is limited. The study aim was to evaluate our 13-year experience with VAA treatment including conservative, open surgical and endovascular therapy. METHODS: This retrospective single-center study included 37 patients (31 male, median age 70 years [46-79 years]) with true and dissecting VAA treated between January 2006 and December 2018. Indications for invasive therapy were ruptured (N.=1) and symptomatic (N.=8) VAA or asymptomatic VAA>20 mm (N.=15). The decision on the treatment type was made after interdisciplinary (vascular surgeons/radiologists) discussion. RESULTS: The aneurysms affected the celiac trunk (N.=18, 49%), the splenic artery (N.=11, 30%), the superior mesenteric artery (SMA, N.=6, 16%), the hepatic artery (N.=5, 14%) and proximal SMA side branches (N.=2, 5%). Six patients had multiple VAA, one had an intrahepatic artery aneurysm and one had peripheral mesocolic artery aneurysms plus a VAA. 46% of the patients (N.=17) had coexisting aneurysms in other vascular territories. Thirteen patients were managed conservatively (median VAA diameter 15 [14-25] mm), 18 underwent open surgery with venous or prosthetic bypass or interposition graft implantation and 6 were treated by endovascular means (coiling [N.=3] or endograft [N.=3]). Median follow-up (FU) was 21 months (4-123 months). In-hospital mortality was 0%. Median length of hospital stay was 11 days (5-28 days) after surgical and 3 days (2-71 days) after endovascular treatment. Complications included an early type I endoleak, 3 secondary open abdominal surgeries for bleeding/peritonitis after endovascular treatment of a ruptured intrahepatic aneurysm, an asymptomatic aorto-truncal bypass occlusion and aneurysm recurrence after a venous SMA interposition graft. None of the conservatively treated VAA required invasive treatment during FU. CONCLUSIONS: Small (<20 mm) asymptomatic VAA can be managed conservatively. Whenever invasive treatment is indicated, both open and endovascular treatments can be performed with low complication rates. In order to choose the optimal therapeutic approach, anatomical features and patient comorbidities should be considered and, ideally, discussed interdisciplinarily.

Combined Surgical and Endovascular Carotid Access for Endovascular Thrombectomy in Acute Ischemic Stroke.

OBJECTIVE: Conventional carotid catheterization is impossible in 2%-5% of acute stroke cases. Surgical carotid cutdown may be a necessary bailout strategy to allow for carotid access. We assessed the effectiveness and safety of surgical carotid cutdown for vascular access in interventional acute stroke treatment. METHODS: We compare imaging and clinical data of 15 consecutive patients, in whom we performed a carotid cutdown for acute stroke treatment with 10 consecutive patients, in whom treatment was discontinued because transfemoral access to the occlusion site was not possible. RESULTS: Baseline characteristics of both groups were comparable (P ≥ 0.065). Cutdown patients had significantly smaller infarctions (P = 0.031), significantly more often favorable clinical outcome (38% vs. 0% modified Rankin score 0-2, P = 0.046), and a lower mortality (31% vs. 60%, P = 0.222) at 3 months. Other than a small hematoma at the operation site, there were no procedure-related complications. CONCLUSIONS: Carotid cutdown is an effective bailout strategy for acute stroke patients, in whom conventional catheterization is not possible.

Feasibility and Twelve-month Patency of a Six-fold Fenestrated Stent Graft for Type IV Thoracoabdominal Aneurysm Repair.

BACKGROUND: Fenestrated endovascular aortic aneurysm repair (FEVAR) is a standard procedure for the treatment of complex aortic aneurysm. More than 4 fenestrations are still randomly used, even in case of complex aneurysm anatomy involving accessory renal arteries. METHODS: We are presenting the case of a 62-year-old male patient suffering from 63-mm juxtarenal aortic aneurysm. Because of his medical history and an ongoing immunosuppressive medication an endovascular approach was conducted. Using a 6-fold fenestrated endograft, 4 renal arteries as well as the superior mesenteric artery and the celiac trunk have been cannulated and stented successfully. RESULTS: No perioperative complications such as impairment of renal function could be observed. After 12 months, still a nonhampered renal function could be assessed. Furthermore, the endoprosthesis showed a good fit without detection of endoleaks, patent fenestrations, and a decreasing aneurysm diameter after 12 months of follow-up. Coverage of accessory renal arteries has been described as an established and necessary technique during endovascular repair of juxtarenal aortic aneurysm; yet coverage of these vessels may be related to renal infarction and an impaired renal function during follow-up. Based on current technical developments the implantation of a 6-fold FEVAR may be conducted with promising results. CONCLUSIONS: Six-fold fenestrated stent-graft prosthesis for the treatment of juxtarenal aortic aneurysm involving accessory renal arteries may be a feasible treatment option related to an appropriate 12-month patency.

Perfusion-related changes in intestinal diffusion detected by NMR-MOUSE® monitoring in minipigs.

OBJECTIVE: The aim was to investigate perfusion-related changes in the intestinal diffusion assessed by NMR-MOUSE monitoring in minipigs. This was a follow-up study of previous experiments on landrace pigs demonstrating the feasibility of NMR-MOUSE monitoring in large animals. METHODS: 5 mature female minipigs (mean body weight 50 ±â€¯2 kg) underwent laparotomy with exposition of several small intestinal loops and their feeding vessels. The loops were examined consecutively using NMR-MOUSE monitoring for assessment of intestinal proton diffusion (fast diffusion component [FC] and slow diffusion component [SC]) and oxygen to see monitoring (O2C, LEA Medizintechnik GmbH, Giessen, Germany) for microcirculatory evaluation. Following a baseline measurement on each loop under physiological perfusion, measurements were continued as one of the following main treatments were performed per loop: method 1 - ischemia; method 2 - flow reduction; method 3 - intraluminal glucose followed by ischemia; method 4 - intraluminal glucose followed by flow reduction. Perioperative monitoring was supplemented by blood gas analyses and histopathological assessment of H.E. stained intestinal biopsies. RESULTS: The NMR-MOUSE measurement showed a significant difference in the change to baseline values in the FC during flow reduction compared to the other treatments according to the unadjusted (pM2 vs. M1 < 0.0001, pM2 vs. M3 = 0.0005, pM2 vs. M4 = 0.0005) and the adjusted p-values (pM2 vs. M1 < 0.0001, pM2 vs. M3 = 0.0030, pM2 vs. M4 = 0.0030). In the SC, the difference between ischemia and flow reduction was significant according to the unadjusted p-values (pM2 vs. M1 = 0.0397). Whereas the FC showed a trend towards ongoing increase during ischemia but towards ongoing decrease during flow reduction, the SC showed contrary trends. These effects seemed to be attenuated by prior glucose application. According to the results of O2C monitoring, ischemia as well as flow reduction caused a significant decrease of microcirculatory oxygen saturation (inner probe: methods 1-4 and outer probe methods 1, 2: p < 0.0001; outer probe: pM2 = 0.0001), velocity (inner probe: pM1 < 0.0001, pM2 = 0.0155, pM3 = 0.0027; outer probe: pM1 < 0.0001, pM2 = 0.0045, pM3 = 0.0047, pM4 = 0.0037) and serosal flow (outer probe, methods 1 and 2: p < 0.0001; pM3 = 0.0009, pM4 = 0.0008). The histopathological analysis showed a significant association with time (p = 0.003) but not with the experimental method (p = 0.1386). CONCLUSIONS: Intestinal diffusion is affected significantly by perfusion changes in mature minipigs. As shown by NMR-MOUSE monitoring, ischemia and flow reduction have contrary effects on intestinal diffusion and, additionally, the fast and slow diffusion components show opposite trends during each of those pathological perfusion states. Prior intraluminal glucose application seems to attenuate the effects of malperfusion on intestinal diffusion.

New Large Animal Model for Aortic Aneurysms in the Viscerorenal Segment.

BACKGROUND: Aortic aneurysms in the viscerorenal-segment are nowadays treatable by endovascular means. Previously, new endograft techniques were only tested in healthy animals. We aimed to establish a new large animal model for testing complex endovascular stent techniques preclinically. METHODS: In sheep, four juxtarenal and two type IV thoracoabdominal aortic aneurysms were surgically created via a retroperitoneal approach. Two pieces out of a 10 × 15-cm bovine pericardial patch were sewn with the healthy aorta longitudinally. The viscerorenal segment was clamped, and the aorta was incised longitudinally. Then, the patches were longitudinally sewn together. In the meantime, antegrade flow through the native part of the aorta was already established by tangential clamping. Computed tomography angiography was performed after 4, 8, and 52 wk. RESULTS: Technical success was 100%. The median surgical procedure time was 3 h, the median blood loss was 210 mL, and the viscerorenal-segment clamping time was 2-4 min. The animals started drinking 1 h after arousal from anesthesia. One animal died after 1 wk because of delayed bleeding and another died after 1 y because of aneurysm rupture by a secondary bacterial infection. Four animals survived. The proximal landing zone diameter and the clock position of the vessel were stable over 52 wk. CONCLUSIONS: Surgical creation of an aortic aneurysm in the viscerorenal-segment in sheep was successful, without an ischemia/reperfusion injury. This animal model offers a new platform for evaluating innovative endovascular therapy options in vivo.

Editor's Choice - Outcomes After One Stage Versus Two Stage Open Repair of Type II Thoraco-abdominal Aortic Aneurysms.

OBJECTIVE: This study compared the outcomes of open one stage with open two stage repair of type II thoraco-abdominal aortic aneurysms (TAAA). METHODS: This retrospective study included 94 patients (68 men) with a mean ± SD age of 54.5 ± 14 years who underwent open type II TAAA repair from March 2006 to January 2016. The mean aneurysm diameter was 65 ± 14.4 mm. The median follow up was 42 months (range 12-96). Seventy-six patients received one stage open repair and 18 patients were treated in two steps: 12 received two open procedures (thoracic and abdominal) and six received hybrid repair (one open and one endovascular procedure). This study focused on the comparison of open one stage and open two stage TAAA repair. The median time between the two steps was 31.5 days (range 1-169). RESULTS: In hospital mortality after open one stage repair versus open two stage type II repair was 22.4% versus 0% (odds ratio 7.352, 95% confidence interval [CI] 0.884-959.1]; p = .19). The one year survival rate after one stage repair versus open two stage repair was 74.7% (95% CI 62.7-83.3) versus 90.9% (95% CI 50.8-98.7 [p = .225]). The five year survival rate after one stage repair versus open two stage repair was 53.0% (95% CI 37.2-66.5) versus 90.9% (95% CI 50.8-98.7 [p = .141]). The hazard ratio for survival after one stage repair and after open two stage repair was 4.563 (95% CI 96.9-81.4 [p = .137]). Paraplegia was observed after open one stage repair versus open two stage in 10.5% vs. 8% (p = 1). Acute kidney injury requiring permanent dialysis and myocardial infarction were assessed for after open one stage repair and open two stage and were seen in 3.9% vs. 0% (p = 1) and in 5.3% vs. 0% (p = 1), respectively. CONCLUSION: Open two stage repair may be recommended as a treatment option for type II TAAAs if anatomically feasible, as it has a lower mortality and similar complication rates to one stage repair.

Comparison of urine and serum neutrophil gelatinase-associated lipocalin after open and endovascular thoraco-abdominal aortic surgery and their meaning as indicators of acute kidney injury.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) has been described as a potential biomarker of acute kidney injury (AKI) in different settings, but its behaviour under influence of open and endovascular repair of thoraco-abdominal aortic aneurysms (TAAA) has not been assessed yet. In this study, the course of NGAL was observed and differences of serum- (sNGAL) and urine-NGAL (uNGAL) levels following TAAA repair, especially with regard to AKI, were evaluated. PATIENTS AND METHODS: In this retrospective single centre study, 52 patients (mean age 64.5 years, [43-85 years]), including 39 (75 %) men, were enrolled (2014-2015, 13.2 months mean follow-up). Levels of sNGAL and uNGAL were measured perioperatively for 48 hours on intensive care unit. Twenty-three patients were treated by endovascular and 29 by open TAAA-repair. RESULTS: Logistic regression revealed an increase in NGAL (sNGAL p = 0.0263, uNGAL p = 0.0080) corresponding with an increase in serum creatinine within the first 48 hours. Fourteen patients (26.9 %) developed AKI and 11 (21.1 %) required dialysis. The course of NGAL differed significantly (uNGAL p < .0001, sNGAL p = 0.0002) between patients suffering from AKI requiring dialysis and patients without AKI. The predictive power of uNGAL was three times higher than that of sNGAL (estimate of the regression slope 0.1382 vs. 0.0460). No significant difference between patients undergoing open or endovascular TAAA repair regarding the perioperative course of sNGAL and uNGAL was observed. CONCLUSION: serum-NGAL and urine-NGAL correlate with serum creatinine levels and AKI requiring dialysis. Furthermore, the postoperative course of sNGAL and uNGAL after open and endovascular TAAA repair is not significantly different. Taken together, the results indicate that uNGAL and, to a lesser extent, sNGAL could be considered biomarkers for early detection of perioperative AKI after open and endovascular TAAA surgery.