Midterm Results of Physician-Modified Stent Grafts for Thoracoabdominal and Complex Abdominal Aortic Aneurysms Repair.

BACKGROUND: To assess midterm results of physician-modified stent grafts (PMSG) for the treatment of emergent complex abdominal and thoracoabdominal aortic aneurysms (TAAA) in high-risk patients. METHODS: All consecutive patients with emergent complex abdominal or TAAA undergoing PMSG technique between January 2012 and July 2019 were retrospectively included. Indications for PMSG were symptomatic aneurysms and rapidly growing aneurysms >70 mm. Ruptured aneurysms were excluded. RESULTS: Thirty-three patients (mean age: 74 +/- 11 years) were included. The mean aneurysm diameter was 76 +- 20 mm. Patients presented with TAAA (n = 20, 61%), complex abdominal aortic aneurysms (CAAA, n = 9, 27%), type I endoleak after previous endovascular aneurysm repair (n = 3, 9%) and intramural aortic hematoma (n = 1, 3%). Chimney technique was performed in addition to PMSG in seven cases (21%). Intraoperative adverse events were recorded in seven cases (35%) in the TAAA group and one case (11%) in the CAAA group. In-hospital mortality rate was 15% (n = 3) in the TAAA group and 11% (n = 1) in the CAAA group. Moderate to severe complications were recorded in 45% of cases (n = 15). Spinal cord ischemia occurred in two cases (6%, one case without residual deficit and one with minor motor deficit). One (3%) patient required transient hemodialysis. One patient presented with early aortic rupture and required an open conversion. The mean follow-up duration was 31 months (1-79). Overall survival estimates were 81.4% (95% confidence interval [CI]: 63.1.-91.2) at 1 year and 71.6% (95% CI: 52.6-84.1) at 2 years. Freedom from reintervention rates at 1 and 2 years were 61.2% (95% CI: 41.7-75.9) and 57.4% (95% CI: 37.9-72.8). Target vessel primary patency rates at 1 and 2 years were 99.2% (95% CI: 94.2-99.9) and 97.7% (95% CI: 90.7-99.4). CONCLUSIONS: PMSG for high-risk patients with complex aneurysms provided acceptable technical success and excellent target vessel patency rates but were associated with a 12% in-hospital mortality rate. Reinterventions were frequent. This technique should be limited to selected high-risk patients for whom the risk of rupture in the short-term is deemed too high to wait for graft manufacturing of custom-made device.

ECMO support as a bridge to lung transplantation is an independent risk factor for bronchial anastomotic dehiscence.

BACKGROUND: Airway complications are frequent after lung transplantation (LT), as they affect up to 23% of recipients. The implication of perioperative extracorporeal membrane oxygenation (ECMO) support and haemodynamic instability has never been specifically assessed. The first aim of this study was to explore the impact of perioperative ECMO support on bronchial anastomotic dehiscence (BAD) at Day 90 after LT. METHODS: This prospective observational monocentric study analysed BAD in all consecutive patients who underwent LT in the Bichat Claude Bernard Hospital, Paris, France, between January 2016 and May 2019. BAD visible on bronchial endoscopy and/or tomodensitometry was recorded. A univariate analysis was performed (Fisher's exacts and Mann-Whitney tests), followed by a multivariate analysis to assess independent risk factors for BAD during the first 90 days after LT (p < 0.05 as significant). The Paris North Hospitals Institutional Review Board approved the study. RESULTS: A total of 156 patients were analysed. BAD was observed in the first 90 days in 42 (27%) patients and was the main cause of death in 22 (14%) patients. BAD occurred during the first month after surgery in 34/42 (81%) patients. ECMO support was used as a bridge to LT, during and after surgery in 9 (6%), 117 (75%) and 40 (27%) patients, respectively. On multivariate analysis, ECMO as a bridge to LT (p = 0.04) and septic shock (p = 0.01) were independent risk factors for BAD. CONCLUSION: ECMO as a bridge to LT is an independent risk factor for BAD during the first 90 days after surgery. Close monitoring of bronchial conditions must be performed in these high-risk recipients.

Midterm results after covered stenting of the superior mesenteric artery.

OBJECTIVE: Despite the continuing controversy of covered stents (CS) vs bare metal stents, the use of CS in mesenteric occlusive disease (MOD) has been recommended by expert centers. The aim of this study was to report midterm results with CS of the superior mesenteric artery. METHODS: Between January 2014 and October 2019, patients with MOD with a severe atheromatous stenosis or occlusion of the superior mesenteric artery treated by mesenteric CS were included. Clinical presentation included both acute mesenteric ischemia (AMI), chronic mesenteric ischemia, and asymptomatic patients planned for major surgery. Demographics, procedure details, and follow-up data were prospectively collected and retrospectively reviewed. Study end points included primary patency, primary assisted patency, and secondary patency. RESULTS: During the study period, 86 patients (mean age, 70 ± 9 years; 57% males) were included. Clinical presentation was AMI (n = 42 [49%]), chronic mesenteric ischemia (n = 31 [36%]), and asymptomatic (n = 13 [15%]). The technical success rate was 97%. A total of 96 stents were implanted, including 86 proximal CS (Advanta V12, n = 73; Lifestream, n = 13). The mean length and mean diameter of the CS were 31.5 ± 6.3 mm and 6.9 ± 0.5 mm, respectively. Additional distal bare metal stents were used in 10 patients (12%) to overcome a kinking (n = 9) or a dissection (n = 1) downstream of the CS. All postoperative deaths occurred in patients with AMI (n = 11, 13%). During a median follow-up of 15.6 months (95% confidence interval [CI], 15.6 ± 3.6 months), 12 patients (14%) underwent reinterventions for either stent misplacement (n = 3), stent recoil (n = 3), stent thrombosis (n = 2), de novo stenosis at the distal edge of the CS (n = 2), or gastric ischemia (n = 1). At 1 year, overall the primary patency, primary assisted patency, and secondary patency rates were 83% (95% CI, 83% ± 9%), 99% (95% CI, 99% ± 3%), and 99% (95% CI, 99% ± 3%), respectively. At 2 years, the overall primary patency, primary assisted patency, and secondary patency rates were 76% (95% CI, 76% ± 13%), 95% (95% CI, 95% ± 8%) and 95% (95% CI, 95% ± 8%), respectively. CONCLUSIONS: Mesenteric CS provide very satisfactory midterm results in patients with MOD, with an excellent primary assisted patency rate at 2 years, at the price of a significant reintervention rate.

Staged hybrid repair of type II thoracoabdominal aneurysms.

BACKGROUND: Open repair of type II thoracoabdominal aortic aneurysms (TAAAs) remains a challenging procedure. Staged procedures could decrease the incidence and severity of complications after complex aortic repair. In the present report, we have described a strategy using thoracic endovascular aortic repair (TEVAR) for proximal repair, followed by distal open repair. METHODS: From 2014 to 2018, 14 patients had undergone TEVAR, followed by distal open repair, for type II TAAAs. All patients should have a suitable proximal landing zone according to the current guidelines. In cases of chronic dissection, false lumen embolization was performed to achieve total exclusion. RESULTS: The mean patient age was 48 ± 15 years. Of the 14 patients, 5 had had Marfan syndrome (36%) and 6 had undergone previous aortic arch repair (43%). Ten patients had had a chronic dissection. The maximal aortic diameter was 73 ± 12 mm. The TEVAR technical success rate was 100%. The aortic length coverage was 211 ± 63 mm. The number of covered segmental arteries was 6 (range, 4-13). Two endoleaks were observed, one type Ib and one type II. The delay between TEVAR and open repair was 12 ± 8 weeks. Cerebrospinal fluid drainage was used in 13 patients. Six patients had undergone segmental artery reattachment during surgery. No spinal cord ischemic event was observed. One patient had died 5 weeks after open repair of multiple organ failure. During the 32 months of follow-up, no aortic-related deaths had occurred. No new aortic procedure was needed. The type Ib endoleak had resolved during open repair, and the type II TAAA had resolved spontaneously. The mean maximal thoracic aortic diameter had significantly decreased to 49 ± 8 mm (P < .0001). Aneurysmal shrinkage of ≥5 mm was observed in 13 patients (93%). CONCLUSIONS: Staged hybrid repair of type II TAAAs appears to be efficient, with low morbidity and mortality rates. This technique could improve postoperative outcomes after open repair, and TEVAR might have a role in ischemic preconditioning to protect against spinal cord ischemia.

Initial Results of Antegrade Laser Fenestrations Using Image Fusion Guidance and Company Manufactured Stent Grafts in Complex Aortic Aneurysm Repair.

OBJECTIVE: The aim was to describe initial outcomes of physician modified stent grafts using antegrade laser fenestrations and image fusion guidance (LEVAR) and company manufactured custom made (CM) stent grafts for the treatment of complex abdominal aortic aneurysms (CAAAs), thoraco-abdominal aortic aneurysms (TAAAs) and type I endoleaks (T1ELs). METHODS: This was a retrospective single centre study. All LEVAR and Zenith (Cook) CM stent graft procedures between 1 January 2012 and 31 December 2018 were reviewed. Endpoints included intra-operative adverse events (IOAEs), in hospital mortality, re-interventions, target vessel patency, and 12 month outcomes (overall survival, freedom from re-intervention, target vessel patency). Outcomes at 12 months were estimated using the Kaplan-Meier method. RESULTS: A hundred patients were identified and included in the study. All patients were deemed unfit for open repair. The cohort included 22 LEVAR and 78 CM stent grafts. LEVAR cases included painful aneurysms (n = 5), > 65 mm aneurysms (n = 10), anatomical constrains and/or presence of previous renal stents (n = 7) or cases declined by the manufacturer planning centre (n = 2). IOAEs were recorded in 41% of cases (n = 9) in the LEVAR group vs. 10% (n = 8, p = .002) in the CM group. The in hospital mortality rate in the LEVAR group was 9% (n = 2) vs. 4% (n = 3, p = .30) in the CM group. The median follow up duration was 22 months (7 - 38) in the LEVAR group and 28 months (11 - 78) in the CM group. The estimate of overall survival at one year was 91% in both groups. The freedom from re-intervention rate at one year was 58% in the LEVAR group vs. 87% in the CM group. The target vessel patency rates at one year were 95% in both groups. CONCLUSION: In high risk patients deemed unfit for open repair, LEVAR may provide satisfactory 12 month overall survival and target vessel patency rates, though reported IOAE, mortality, and re-interventions rates were high thus requiring close and extensive follow up.

Retrograde Open Mesenteric Stenting for Acute and Chronic Mesenteric Ischaemia: Results from an Intestinal Stroke Centre.

OBJECTIVE: To report the intra-operative adverse events (IOAEs) and the initial and one year outcomes of retrograde open mesenteric stenting (ROMS) using balloon expandable covered stents for acute and chronic mesenteric ischaemia. METHODS: Clinical data and outcomes of all consecutive patients treated with ROMS for acute and chronic mesenteric ischaemia at an intestinal stroke centre between November 2012 and September 2019 were reviewed. ROMS was performed using balloon expandable covered stents. Endpoints included IOAEs, in hospital mortality, post-operative complications, and re-interventions. One year overall survival, freedom from re-intervention, primary patency and assisted primary patency rates were analysed using the Kaplan-Meier time to event method. RESULTS: During the study period, 379 patients were referred to the centre for acute or chronic mesenteric ischaemia. Thirty-seven patients who underwent the ROMS procedure were included. All the patients had severe atherosclerotic mesenteric lesions. The ROMS technical success rate was 89% in this cohort. The rate of IOAEs was 19% and included four cases of retrograde recanalisation failure. All ROMS failures occurred in patients presenting with flush superior mesenteric artery occlusion and they were treated by mesenteric bypass. Ten patients (27%) underwent bowel resection, four of which resulted in a short bowel syndrome (11%). The in hospital mortality rate was 27%. Post-operative complications and re-intervention rates were 67% (n = 25) and 32% (n = 12), respectively. The median follow up was 20.2 months (interquartile range 29). The estimated one year overall survival for the cohort was 70.1% (95% confidence interval [CI] 52.5% - 82.2%). The estimated freedom from re-intervention at one year was 61.1% (95% CI 42.3 - 75.4). The one year primary patency and assisted primary patency rates were 84.54% (95% CI 63.34 - 94) and 92.4% (95% CI 72.8 - 98), respectively. CONCLUSION: ROMS procedures offer acceptable one year outcomes for mesenteric ischaemia but are associated with frequent stent related complications. Precise pre-operative planning, high quality imaging, and meticulous stent placement techniques may limit the occurrence of such events.

Persistence of Intraluminal Thrombus Makes Saccular Aneurysm More Biologically Active than Fusiform in an Experimental Rat Model.

INTRODUCTION: Saccular aneurysms are thought to have a worse prognosis than fusiform aneurysms in humans, due to hemodynamic reasons. However, data comparing hemodynamic and biology in saccular and fusiform aneurysms are lacking. The main objective was to evaluate the impact of aneurysm morphology on intra-luminal thrombus (ILT) formation and activity. METHODS: Forty Lewis rats were ran-domly divided into 2 groups of 20: "saccular" (Group A) and "fusiform" (Group B) aneurysms. Decellularized thoracic aortas from guinea pigs were xenografted to create saccular or fusiform aneurysms. Final imaging evaluation of the aneurysms was carried out during the third week, by quantitative Doppler ultrasound and magnetic resonance imaging. Assays of myeloperoxidase (MPO), platelet factor 4 (PF4), advanced oxidation protein products (AOPPs) iron and matrix metallopeptidase-9 (MMP-9) were performed as biological criteria. RESULTS: Quantitatively, saccular aneurysms are characterized by a more thicker ILT, lower inflow velocities and more important relative backflow velocities as compared to fusiform aneurysms. Compared to fusiform, saccular aneurysms released significantly more MPO (p = 0.004), PF4 (p = 0.02), AOPPs (p < 0.002), iron (p < 0.0001) and MMP-9 (p < 0.04). CONCLUSION: Experimental saccular and fusiform aneurysms show differential specific hemodynamics, which seem to impact the histology and the biology of the ILT in each type of aneurysm.

Intraoperative adverse events and early outcomes of custom-made fenestrated stent grafts and physician-modified stent grafts for complex aortic aneurysms.

OBJECTIVE: Physician-modified fenestrated stent grafts (PMSGs) are a useful option for urgent or semiurgent treatment of complex abdominal aortic aneurysms (CAAAs). The aim of this study was to describe in-hospital outcomes of custom-made fenestrated stent grafts (CMSGs) and PMSGs for the treatment of CAAAs and thoracoabdominal aortic aneurysms (TAAAs). METHODS: In this single-center, retrospective study, all consecutives patients with CAAAs or TAAAs undergoing endovascular repair using Zenith CMSGs (Cook Medical, Bloomington, Ind) or PMSGs between January 2012 and November 2017 were included. End points were intraoperative adverse events, in-hospital mortality, postoperative complications, reinterventions, target vessel patency, and endoleaks. RESULTS: Ninety-seven patients were included (CMSGs, n = 69; PMSGs, n = 28). The PMSG group included more patients assigned to American Society of Anesthesiologists class 4 (n = 14 [50%] vs n = 16 [23%]; P = .006) and more TAAAs (n = 17 [61%] vs n = 10 [15%]; P < .0001). Intraoperative adverse events were recorded in eight (11%) patients in the CMSG group vs six (21%) patients in the PMSG group. No intraoperative death or open conversion occurred. In-hospital mortality rates were of 4% (n = 3) in the CMSG group and 14% in the PMSG group (n = 4). Chronic renal failure was an independent preoperative risk factor of postoperative death or complications (odds ratio, 4.88; 95% confidence interval, 1.65-14.43; P = .004). Rates of postoperative complications were 22% (n = 15) and 25% (n = 7) in the CMSG and PMSG groups. Spinal cord ischemia rates were 4% (n = 3) and 7% (n = 2) in the CMSG and PMSG groups. Reintervention rates were 16% (n = 11) in the CMSG group and 32% (n = 9) in the PMSG group. At discharge, target vessel patency rate in CMSGs was 98% (n = 207/210). All target vessels (n = 98) were patent in the PMSG group. Endoleaks at discharge were observed in 24% of the CMSG group (n = 16) vs 8% of the PMSG group (n = 2). CONCLUSIONS: Our study showed clinically relevant differences of several important in-hospital outcomes in the CMSG and PMSG groups. Larger cohorts and longer follow-up are needed to allow direct comparison. PMSGs may offer acceptable in-hospital results in patients requiring urgent interventions when CMSGs are not available or possible.

Patient Specific Computer Modelling for Automated Sizing of Fenestrated Stent Grafts.

OBJECTIVE: The aim was to validate a computational patient specific model of Zenith® fenestrated device deployment in abdominal aortic aneurysms to predict fenestration positions. METHODS: This was a retrospective analysis of the accuracy of numerical simulation for fenestrated stent graft sizing. Finite element computational simulation was performed in 51 consecutive patients that underwent successful endovascular repair with Zenith® fenestrated stent grafts in two vascular surgery units with a high volume of aortic procedures. Longitudinal and rotational clock positions of fenestrations were measured on the simulated models. These measurements were compared with those obtained by (i) an independent observer on the post-operative computed tomography (CT) scan and (ii) by the stent graft manufacturer planning team on the pre-operative CT scan. (iii) Pre- and post-operative positions were also compared. Longitudinal distance and clock face discrepancies >3 mm and 15°, respectively, were considered significant. Reproducibility was assessed using Bland-Altman and linear regression analysis. RESULTS: A total of 195 target arteries were analysed. Both Bland-Altman and linear regression showed good reproducibility between the three measurement techniques performed. The median absolute difference between the simulation and post-operative CT scan was 1.0 ± 1.1 mm for longitudinal distance measurements and 6.9 ± 6.1° for clock positions. The median absolute difference between the planning centre and post-operative CT scan was 0.8 ± 0.8 mm for longitudinal distance measurements and 5.1 ± 5.0° for clock positions. Finally, the median absolute difference between the simulation and the planning centre was 0.96 ± 0.97 mm for longitudinal distance measurements and 4.8 ± 3.6° for clock positions. CONCLUSION: The numerical model of deployed fenestrated stent grafts is accurate for planning position of fenestrations. It has been validated in 51 patients, for whom fenestration locations were similar to the sizing performed by physicians and the planning centre.

Using the OUTBACK Catheter to Overcome Aortic Reentry Issues in Retrograde Open Mesenteric Stenting.

BACKGROUND: The purpose of this study was to describe the use of the OUTBACK catheter to overcome aortic reentry issues in acute mesenteric ischemia (AMI) treated by retrograde open mesenteric stenting (ROMS). TECHNIQUE: The technique is demonstrated in two female patients presenting with late AMI related to flush occlusion of the superior mesenteric artery (SMA). In such cases of thrombotic AMI with clear preoperative evidence of intestinal necrosis, ROMS is the first-line revascularization technique in our intestinal stroke center. Following an open approach of the SMA through laparotomy, the SMA was punctured in a retrograde fashion. Retrograde mesenteric subintimal recanalization was initiated. In case of aortic reentry issue, the OUTBACK Elite (Cordis, Hialeah, Fl) catheter was advanced through the occlusion over a 0.014 guidewire. The aortic reentry was created by puncture of the aortic wall with the OUTBACK needle, positioned in the desired position. After low-profile balloon angioplasty of the reentry site and 0.035 guidewire exchange, ROMS was performed using balloon-expandable covered stent. CONCLUSIONS: The OUTBACK catheter appears to be a safe and effective tool to overcome aortic reentry issues in ROMS. This technical tip might therefore increase the technical success rate of challenging ROMS and decrease the need for bailout bypass in the septic context of AMI.

Translational Relevance and Recent Advances of Animal Models of Abdominal Aortic Aneurysm.

Human abdominal aortic aneurysm (AAA) pathophysiology is not yet completely understood. In conductance arteries, the insoluble extracellular matrix, synthesized by vascular smooth muscle cells, assumes the function of withstanding the intraluminal arterial blood pressure. Progressive loss of this function through extracellular matrix proteolysis is a main feature of AAAs. As most patients are now treated via endovascular approaches, surgical AAA specimens have become rare. Animal models provide valuable complementary insights into AAA pathophysiology. Current experimental AAA models involve induction of intraluminal dilation (nondissecting AAAs) or a contained intramural rupture (dissecting models). Although the ideal model should reproduce the histological characteristics and natural history of the human disease, none of the currently available animal models perfectly do so. Experimental models try to represent the main pathophysiological determinants of AAAs: genetic or acquired defects in extracellular matrix, loss of vascular smooth muscle cells, and innate or adaptive immune response. Nevertheless, most models are characterized by aneurysmal stabilization and healing after a few weeks because of cessation of the initial stimulus. Recent studies have focused on ways to optimize existing models to allow continuous aneurysmal growth. This review aims to discuss the relevance and recent advances of current animal AAA models. VISUAL OVERVIEW: An online visual overview is available for this article.

Computer-assisted study of the axial orientation and distances between renovisceral arteries ostia.

PURPOSE: Endovascular navigation in aortic, renal and visceral procedures are based on precise knowledge of arterial anatomy. Our aim was to define the anatomical localization of the ostia of renovisceral arteries and their distribution to establish anatomical landmarks for endovascular catheterization. METHODS: Computer-assisted measurements performed on 55 CT scans and patients features (age, sex, aortic diameter) were analyzed. p values <0.05 were considered statistically significant. RESULTS: The mean axial angulation of CeT and the SMA origin was 21.8° ± 10.1° and 9.9° ± 10.5°, respectively. The ostia were located on the left anterior edge of the aorta in 96 % of cases for the CeT and 73 % for the SMA. CeT and SMA angles followed Gaussian distribution. Left renal artery (LRA) rose at 96° ± 15° and in 67 % of cases on the left posterior edge. The right renal artery (RRA) rose at -62° ± 16.5° and in 98 % of cases on the right anterior edge of the aorta. RRA angle measurements and cranio-caudal RRA-LRA distance measurements did not follow Gaussian distribution. The mean distances between the CeT and the SMA, LRA, and RRA were 16.7 ± 5.0, 30.7 ± 7.9 and 30.5 ± 7.7 mm, respectively. CeT-SMA distance showed correlation with age and aortic diameter (p = 0.03). CeT-LRA distance showed correlation with age (p = 0.04). The mean distance between the renal ostia was 3.75 ± 0.21 mm. The RRA ostium was higher than the LRA ostium in 52 % of cases. RRA and LRA origins were located at the same level in 7 % of cases. CONCLUSION: Our results illustrate aortic elongation with ageing and high anatomical variability of renal arteries. Our findings are complementary to anatomical features previously published and might contribute to enhance endovascular procedures safety and efficacy for vascular surgeons and interventional radiologists.