Marwan Youssef

Patency of renal and visceral vessels after open thoracoabdominal aortic replacement

OBJECTIVE In thoracoabdominal aortic aneurysms (TAAAs), a paradigm shift is observed from open surgery toward total endovascular aortic repair using fenestrated and branched endografts. Whereas outcome after open replacement in terms of mortality and paraplegia has been evaluated extensively, no studies exist addressing long-term patency of visceral and renal vessels. To enable comparison of target vessel patency between open and endovascular treatment, we analyzed our series of open TAAA replacements. METHODS Our vascular surgery database was screened for patients who received open TAAA replacement between 1998 and 2012, and patient records were analyzed retrospectively. All available imaging scans (computed tomography and magnetic resonance angiography: preoperative, postoperative, and follow-up) were evaluated for graft and vessel patency. RESULTS We identified 62 patients (mean age, 66 ± 10 years; 40 men) who had been operated on for aneurysms of Crawford types I (8), II (13), III (13), and IV (24) and Safi type V (4). A total of 181 vessels were revascularized by either patch inclusion (n = 147) or selective revascularization (bypass or transposition, n = 34); 48 survived the procedure, resulting in a number of vessels available for follow-up of 154 (patch, 126; selective revascularization, 28). The respective patency rates for overall, patch, and selective revascularization were 95.2%, 94.2%, and 100% at 5 years and 83.7%, 81.3%, and 100% at 10 years, respectively. In addition, a trend for better performance of selective revascularization (bypass or transposition) was evident as all vessel occlusions were observed in cases of patch inclusion, whereas all selectively revascularized vessels were patent. The respective patency rates for the celiac trunk, superior mesenteric artery, and left and right renal artery were 100%, 97.5%, 92.3%, and 90.3% at 5 years. CONCLUSIONS In our series of open thoracoabdominal aortic replacement, excellent patency rates for revascularized renal and visceral vessels were observed during long-term follow-up. We were able to provide a reference value of long-term target vessel patency that can and should be taken into account to judge the efficacy of endovascular repair in TAAA.

Endovascular Aneurysm Sealing (EVAS) and Chimney EVAS in the Treatment of Failed Endovascular Aneurysm Repairs

Purpose: To assess the technical success and clinical outcome of reinterventions using the Nellix Endovascular Aneurysm Sealing (EVAS) System to treat complications after endovascular aneurysm repair (EVAR). Methods: Fifteen consecutive patients (mean age 79 years; 14 men) with prior EVAR were treated with EVAS between March 2014 and December 2015 at 2 institutions. The failed prior EVARs included 13 bifurcated endografts, 1 bifurcated graft plus fenestrated cuff, and 1 tube endograft. Endoleaks were the predominant indications: type Ia in 10 and type III in 5 (3 type IIIa and 2 type IIIb). All patients presented with progressive aortic aneurysms (median 7.85-cm diameter; range 6.5–11). Eight patients were treated on an urgent or emergency basis (6 symptomatic aneurysms and 2 contained ruptures). All patients underwent Nellix relining of the failed stent-graft; 10 had chimney (Ch) procedures in combination with EVAS (chEVAS) because the proximal landing zones were inadequate. Results: Technical success was 100%. All endoleaks were successfully sealed, and no additional intervention was required. No further endoleak after EVAS or chEVAS was recorded. Endobag protrusion occurred in 1 case without sequelae. One elderly patient with ruptured aneurysm died from multiple organ failure 2 months postoperatively. One renal artery guidewire injury led to nephrectomy because of active bleeding. No reinterventions, aneurysm-related mortalities, graft thrombosis, endoleaks, or chimney graft occlusions were observed during a median follow-up of 8 months (range 3–24). Conclusion: The present preliminary experience demonstrates that the use of EVAS/chEVAS is feasible for treatment of failed EVAR. This technique may be used as bailout or an alternative treatment when other established methods are infeasible or not available.

Initial Experience in the Treatment of Extensive Iliac Artery Aneurysms With the Nellix Aneurysm Sealing System.

Purpose: To assess the feasibility and effectiveness of the Nellix prosthesis in the treatment of common iliac artery aneurysms. Methods: Between May 2013 and June 2015, 230 patients underwent implantation of the Nellix device at 2 institutions. Fifty of these patients (mean age 76 years; 35 men) were identified as having 60 common iliac artery aneurysms (CIAAs) with a median diameter of 4 cm (range 3.5–7). The majority of patients had aortoiliac aneurysms (5, 70%), 10 (20%) had isolated CIAAs, and 5 (10%) had iliac anastomotic aneurysms after aortoiliac bypass. In 20 patients, the iliac aneurysm was the indication for the intervention; in the other 30 patients, the endovascular iliac repair was an adjunct procedure to endovascular aneurysm sealing (EVAS). An iliac branch device (IBD) was used when feasible to preserve flow to the internal iliac artery. Results: Seventeen (34%) patients underwent elective implantation of the Nellix graft in combination with an IBD, 33 (66%) patients underwent Nellix sealing of the CIAA using 1 (n=5), 2 (n=22), or 3 Nellix grafts (2 bilateral grafts and 1 graft as an extension to the external iliac artery in 6 patients). The technical success rate was 100%, and no graft-related complications were reported postoperatively. No buttock claudication, reinterventions, graft thrombosis, or endoleaks were observed during a mean follow-up of 12 months. Conclusion: Our initial experience demonstrates that Nellix grafts are feasible and safe for the treatment of extensive iliac artery aneurysms. The long-term durability of these grafts should be validated in larger patient cohorts before this promising alternative endovascular technique can gain widespread acceptance.

Endovascular Repair of Paravisceral Aortic Aneurysms Combining Chimney Grafts and the Nellix Endovascular Aneurysm Sealing Technology (Four-Vessel ChEVAS)

Background We demonstrate our initial experience and first results of the endovascular aneurysm sealing (EVAS) technology with chimney grafts for the treatment of paravisceral aneurysms. Methods We present a consecutive series of seven patients with a mean age of 75 years who had been treated by four‐vessel‐chimney EVAS (ChEVAS) between May 2014 and May 2015. All patients were ASA grade ≥ III and were not eligible for fenestrated/branched endovascular aortic repair (fEVAR/brEVAR) due to urgency (n = 5) or anatomical constraints (n = 2). Results Total 28 renovisceral target vessels were treated by balloon‐expandable covered stents and 14 Nellix devices were used to seal the paravisceral aorta. Overall, 16 Nellix (Endologix Inc., Irvine, California, United States) devices and 65 covered stents were implanted with a technical success of 100%. Perioperatively, one patient with ruptured aneurysm died due to respiratory failure following splenic laceration/splenectomy (mortality = 14%) and in one patient, laceration of an axillary access vessel occurred. At a median follow‐up of 6 months, all six surviving patients were well and no reinterventions were necessary. One chimney was found occluded without clinical sequelae resulting in a patency rate of 96%. Conclusion Four‐vessel ChEVAS may serve as alternative treatment option in highly selected cases of either acute paravisceral aortic pathology and/or situations, where the implantation of fEVAR/brEVAR is hampered by anatomical constraints. Further follow‐up and a multicenter study are of course warranted to corroborate these initial results.

Three-Dimensional Analysis of Component Stability of the Nellix Endovascular Aneurysm Sealing System After Treatment of Infrarenal Abdominal Aortic Aneurysms.

Purpose: To assess short-term stability and conformational changes of the Nellix EndoVascular Aneurysm Sealing (EVAS) System using 3-dimensional (3D) analysis. Methods: Postoperative computed tomography (CT) scans obtained at 0, 3, and 12 months in 24 patients (mean age 75±7 years; 22 men) who underwent EVAS between December 2013 and December 2014 for intact abdominal aortic aneurysm (within the instructions for use) were evaluated for stent-graft deviation in multiple planes using dedicated 3D analysis software. In addition, 2D analysis using an anatomically fixed reference landmark was performed to assess craniocaudal migration. Clinical and follow-up data of the patients were recorded and matched with results of the imaging analysis. Results: Overall stability of the Nellix endografts was promising. Relevant conformational changes in the majority of cases were limited to the iliac graft segment and were clinically benign in all cases. Conversely, the only deviation of the proximal stent-graft segment was found in a patient with type Ia endoleak. Additional 2D analysis found relevant (≥5 mm) caudal migration of the Nellix stent-graft in 6 patients, including the one with the type Ia endoleak. In 3 patients, 3D analysis demonstrated the absence of relevant conformational changes of the endografts despite caudal migration. Conclusion: Overall stability of the separate EVAS stent-grafts is promising in the short term. Relevant conformational changes (stent-graft deviation) in the majority of cases were benign and confined to the iliac segment.

Early Experience With Endovascular Aneurysm Sealing in Combination With Parallel Grafts for the Treatment of Complex Abdominal Aneurysms: The ASCEND Registry:

Purpose: To report the results of the ASCEND Registry of cases involving endovascular aneurysm sealing (EVAS) in combination with chimney grafts (chEVAS) for the treatment of para- and juxtarenal aortic aneurysms (AAA). Methods: A retrospective, multicenter registry established in 8 vascular centers between 2013 and 2016 recorded the treatment results and follow-up of chEVAS procedures for nonruptured AAAs; data were analyzed using standardized outcome measures. In the observation period, 154 patients (mean age 72.3±7.7 years; 124 men) underwent elective treatment for de novo juxtarenal and pararenal aneurysms and formed the study group. Results: Sixty-two (40.3%) of the cohort were treated using a single parallel graft, 54 (35.1%) with double chimneys, 27 (17.5%) with triple chimneys, and 11 (7.1%) with 4 chimneys. The 30-day mortality was 2.8%, and there were 4 perioperative strokes (1 fatal). At 1 year, the freedom from all-cause mortality was 89.8% and the freedom from aneurysm-related mortality was 94.3%. There were 3 endoleaks within 90 days of the procedure, one type Ia and 2 type Ib. The freedom from type Ia endoleaks was 95.7% at 1 year. There were no types II or III endoleaks in this series; the freedom from all endoleaks was 94.2% at 1 year. Freedom from reintervention at 1 year was 89.2%. Target vessel patency rates at 1 year were 97.7%, 99.3%, 100%, and 100% for the left renal, right renal, superior mesenteric artery, and celiac axis stents, respectively. Conclusion: The ASCEND Registry supports a proof of concept for the use of polymer technology and EVAS with parallel grafts in managing patients with complex aortic disease. The future role of chEVAS will be defined by studies that assess mid- to long-term durability.

Treating iliac aneurysm using the Nellix Endovascular Sac Sealing System.

As endovascular treatment of abdominal aortic aneurysms has become established, there has been growing focus on treatment of the aneurysmal iliac artery. Isolated, large iliac aneurysms >30 mm pose a risk of rupture, but, in addition, 20% to 30% of abdominal aortic aneurysms are associated with iliac aneurysmal dilatation, which can compromise long-term outcomes. Endovascular solutions are evolving and until recently have utilized standard stent graft technology. The endovascular aortic sealing system was introduced as a new, effective method for the treatment of infrarenal aortic aneurysms. In this article, we present our recent extended use of the Nellix system, with or without a combination of adjuvant endovascular techniques, in the treatment of 84 common iliac artery aneurysms. The results support the use of endovascular aortic sealing system in endovascular therapy for aneurysmal iliac pathologies. Different endovascular sealing techniques for the treatment of common iliac artery aneurysms, re-interventions, and extended follow-up are also discussed.

A Multicenter Experience With a New Fenestrated-Branched Device for Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Purpose: To investigate the outcomes of patients who were treated for thoracoabdominal aortic aneurysms (TAAAs) using custom-made fenestrated-branched stent-grafts. Methods: A consecutive series of 108 patients (mean age 73.5 years; 73 men) with TAAA were treated with E-xtra Design Engineering customized fenestrated-branched stent-grafts between November 2011 and January 2017. Data on baseline characteristics, procedures, and clinical follow-up were collected from 6 regional European surgical centers for retrospective analysis of endoleaks, reinterventions, and target vessel patency. The median aneurysm diameter was 6.75 cm (range 5.5–13). The distribution of the TAAA according to the modified Crawford classification of extent was 25 (24%) type I, 19 (17%) type II, 20 (18%) type III, 29 (27%) type IV, and 15 (14%) type V. Results: Technical success was achieved in 95% (103/108) of cases. Major early perioperative complications occurred in 40 (37%) patients. The 30-day mortality was 9.2% (10/108), and perioperative spinal cord ischemia was observed in 6 (5.5%) patients [2 (1.8%) permanent]. During the mean follow-up of 17.6 months (range 3–52), 28 (26%) patients required late reintervention. Two patients died due to aneurysm- or procedure-related causes. The estimated survival rates at 1, 2, and 4 years were 87%, 84%, and 51%, respectively. The estimated target vessel patency rates at the same time points were 95%, 91%, and 90%, respectively. The freedom from reintervention estimates were 84% and 73% at 1 and 4 years, respectively. Conclusion: Endovascular repair of TAAA using Jotec customized fenestrated-branched stent-grafts appears to be safe and effective in the early to midterm. The considerable rate of secondary interventions indicates that further improvements, graft surveillance, and follow-up are required.

Adjunct Perfusion Branch for Reduction of Spinal Cord Ischemia in the Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Abstract Background To analyze utilization of a perfusion branch for temporary sac perfusion to reduce the spinal cord ischemia (SCI) in the endovascular repair of thoracoabdominal aortic aneurysms (TAAAs). Methods Between January 2012 and August 2016, 30 patients (18, men; median age 72 years) were treated for TAAAs with total endovascular repair using customized branched/fenestrated endografts in our institution. The median aneurysm size was 6.6 cm. Types of TAAA were: type I, 9 (30%), type II, 5 (16.6%), type III, 4 (13.3%), type IV, 6 (20%), and type V, 6 (20%). Ten patients received a perfusion branch to create an intentional endoleak, which was occluded with vascular plugs in mean interval time of 8.2 weeks (range: 6‐10). Staged procedure and automated cerebrospinal fluid drainage were used in 23 (77%) and 24 (80%) patients, respectively. Results The technical success was 97%; 107 renovisceral target vessels were revascularized (32 fenestrations, 75 branches). At the time of the planned reinterventions, the mean arterial pressure (MAP) gradients were measured between the temporarily perfused aneurysm sac and the aortic endografts, and they were significantly higher (mean gradients 42.5 ± 10 mm Hg; range: 30‐60) within the aortic grafts. The in‐hospital and 30‐day mortality was 3.3%. The incidence of postoperative SCI was 3/20 (15%) in the standard group and 0% in the group of the perfusion branch (p = 0.28). The mean follow‐up was 12 months (range: 2‐51). Conclusion We experience that the use of a dedicated perfusion branch is feasible and may serve as protective adjunct to reduce the risk of SCI in endovascular treatment of TAAA. The risk of rupture in interval appears to be low. Larger series and multicenter studies are warranted to corroborate these results.

Septic cardiomyopathy: evidence for a reduced force-generating capacity of human atrial myocardium in acute infective endocarditis

Abstract Background: This study analyzes the myocardial force-generating capacity in infective endocarditis (IE) using an experimental model of isolated human atrial myocardium. In vivo, it is difficult to decide whether or not alterations in myocardial contractile behavior are due to secondary effects associated with infection such as an altered heart rate, alterations of preload and afterload resulting from valvular defects, and altered humoral processes. Our in vitro model using isolated human myocardium, in contrast, guarantees exactly defined experimental conditions with respect to preload, afterload, and contraction frequency, thus not only preventing confounding by in vivo determinants of contractility but also excluding effects of other factors associated with sepsis, hemodynamics, humoral influences, temperature, and medical treatment. Methods: We analyzed right atrial trabeculae (diameter 0.3–0.5 mm, initial length 5 mm) from 32 patients undergoing aortic and/or mitral valve replacement for acute valve incompetence caused by IE and 65 controls receiving aortic and/or mitral valve replacement for nonendocarditic valve incompetence. Isometric force amplitudes and passive resting force values measured at optimal length in the two groups were compared using Student’s t-test. Results: There were no significant differences between the groups in terms of the passive resting force. The isometric force amplitude in the endocarditis group, however, was significantly lower than in the nonendocarditis group (p=0.001). In the endocarditis group, the calculated active force, defined as the isometric force amplitude minus the resting force, was significantly lower (p<0.0001) and the resting force/active force ratio was significantly higher (p<0.0001). Using linear regression to describe the function between resting force and active force, we identified a significant difference in slope (p<0.0001), with lower values found in the endocarditis group. Conclusion: Our data suggest that the force-generating capacity of atrial myocardium is significantly reduced in patients with IE. In these patients, an elevated resting force is required to achieve a given force amplitude. It remains unclear, however, whether this is due to calcium desensitization of the contractile apparatus, presence of myocardial edema, fibrotic remodeling, disruption of contractile units, or other mechanisms.