Early Postoperative Renal Dysfunction Predicts Long-Term Renal Function Degradation after Type IV Thoracoabdominal Aortic Aneurysm Surgical Repair.

BACKGROUND: Type IV thoracoabdominal aortic aneurysm surgical repair is often complicated by postoperative acute kidney injury. The aim was to evaluate early renal injury influence on long-term renal function. METHODS: All type IV thoracoabdominal surgical repair performed between January 2000 and January 2014 in our tertiary hospital were included in this retrospective observational study. All procedures were performed through a retroperitoneal approach with at least suprarenal aortic cross-clamping. Cold Ringer Lactate was used to perfuse the kidneys. Serum creatinine (Scr.) and glomerular filtration rate (GFR) were recorded preoperatively, daily until discharge and at least annually during follow-up. Postoperative renal dysfunction was classified using the RIFLE score. Predictors of long-term renal decline were identified by logistic regression and a Cox model. RESULTS: Of total, 80 patients were included. Aortic clamping level was suprarenal (10%), supramesenteric (37%) or supracoeliac (53%). Ischemic durations were 29 ± 9 min for the gastrointestinal tract and the right kidney, 54 ± 28 min for the left kidney. Three patients died postoperatively. At discharge, 31 (38.8%) patients did not have a postoperative renal impairment (RIFLE-), compared with 49 (61.2%) who had a renal dysfunction (RIFLE+). GFR was 89 ± 29 ml/min vs 68 ± 37 ml/min, respectively (P < 0.01). In the RIFLE + group, Scr. was increased by x1.5 (Risk) for 22 patients, x2 (Injury) for 19 patients, and ×3 (Failure) for 8 patients. Mean follow-up was 59 months. Eighteen patients died, and 2 patients started permanent dialysis at 46 and 118 months during follow-up. The only predictive factor of long-term GFR degradation was a postoperative GFR below 45 ml/min (OR: 16.5; 95%; P < 0.001). CONCLUSIONS: Postoperative renal dysfunction was a frequent complication, associated with long-term renal function degradation.

Long-term Outcomes after Transplant Renal Artery Stenosis Surgery.

The occurrence of transplant renal artery stenosis (TRAS) ranges from 1 to 23% and is associated with resistant hypertension, volume overload, graft dysfunction, and poor long-term graft and patient survival. Enhancing graft availability with expanded criteria donors results in the transplantation of kidneys with atherosclerotic arteries, increasing the risk of vascular complications. Although endovascular management is the first-line strategy in this context, in some patients, surgery has to be considered. We report the experience and long-term follow-up of TRAS surgery in a French kidney transplantation center. Between 2004 and 2009, 10 patients with postoperative TRAS, considered unfit for an endovascular procedure by a multidisciplinary team, were addressed for surgery. Mean time from transplantation to surgery was 139.8 ± 136.4 days. Clinical indications were oliguria, anuria, or acute decrease in urine output (n = 5), resistant hypertension (n = 4), and persistence of a decreased allograft function (n = 1). Imaging-revealed ostial stenosis is associated with external iliac artery stenosis (n = 3) or early bifurcation (n = 2), and kinking (n = 5). Revascularization techniques consisted in a great saphenous vein bypass (n = 5) and internal iliac artery anastomosis (n = 5). In the postoperative period, there was no graft loss, but 2 patients required hemodialysis during the first week. Mean follow-up was 9.8 ± 2.1 years. One patient lost his graft 10.3 years after transplantation due to chronic rejection, and 1 patient needed endovascular dilation. There was no graft loss at 5 years. Blood pressure was controlled in all patients. Surgical intervention for TRAS is safe and effective on graft survival and graft function and has to be considered for patients unsuitable for endovascular repair.

Low baseline and subsequent higher aortic abdominal aneurysm FDG uptake are associated with poor sac shrinkage post endovascular repair.

PURPOSE: The growth phases of medically treated abdominal aortic aneurysms (AAA) are frequently associated with an 18F-fluorodesoxyglucose positron emission tomography (FDG-PET) pattern involving low baseline and subsequent higher FDG uptake. However, the FDG-PET patterns associated with the endovascular aneurysm repair (EVAR) of larger AAA are presently unknown. This study aimed to investigate the relationship between serial AAA FDG uptake measurements, obtained before EVAR and 1 and 6 months post-intervention and subsequent sac shrinkage at 6 months, a well-recognized indicator of successful repair. METHODS: Thirty-three AAA patients referred for EVAR (maximal diameter: 55.4 ± 6.0 mm, total volume: 205.7 ± 63.0 mL) underwent FDG-PET/computed tomography (CT) before EVAR and at 1 and 6 months thereafter, with the monitoring of AAA volume and of a maximal standardized FDG uptake [SUVmax] averaged between the axial slices encompassing the AAA. RESULTS: Sac shrinkage was highly variable and could be stratified into three terciles: a first tercile in which shrinkage was absent or very limited (0-29 mL) and a third tercile with pronounced shrinkage (56-165 mL). SUVmax values were relatively low at baseline in the 1st tercile (SUVmax: 1.69 ± 0.33), but markedly increased at 6 months (2.42 ± 0.69, p = 0.02 vs. baseline). These SUV max values were by contrast much higher at baseline in the 3rd tercile (SUVmax: 2.53 ± 0.83 p = 0.009 vs. 1st tercile) and stable at 6 months (2.49 ± 0.80), while intermediate results were documented in the 2nd tercile. Lastly, the amount of sac shrinkage, expressed in absolute values or in percentages of baseline AAA volumes, was positively correlated with baseline SUVmax (p = 0.001 for both). CONCLUSION: A low pre-EVAR FDG uptake and increased AAA FDG uptake at 6 months are associated with reduced sac shrinkage. This sequential FDG-PET pattern is similar to that already shown to accompany growth phases of medically treated AAA.

Elastase inhibitor AZD9668 treatment prevented progression of experimental abdominal aortic aneurysms.

OBJECTIVE: Abdominal aortic aneurysm (AAA) is a particular form of arterial disease characterized by the dilation of the aortic wall and the presence of an intraluminal thrombus linked to a high proteolytic activity. The aim of this study was to investigate the effect of an elastase inhibitor (AZD9668 from AstraZeneca) on aneurysm progression. METHODS: For this purpose, we have used a rat model of elastase perfusion followed by repeated injection of Porphyromonas gingivalis (Pg), a weak periodontal pathogen recently reported to enhance AAA thrombus formation. Pg (1.10(7) colony-forming units) was injected through the jugular vein once a week for 4 weeks, and AZD9668, incorporated in the food, was delivered concomitantly. RESULTS: Our results show a beneficial effect of AZD9668 treatment on AAA progression and composition. The increased AAA diameter induced by Pg was significantly reduced by AZD9668 treatment. Histologic analyses allowed us to observe the persistence of a neutrophil-rich luminal thrombus associated with calcifications in Pg-injected rats and the presence of a healing process in the Pg/AZD9668-treated group. The enhanced concentrations of markers of neutrophil activation, cell-free DNA, and myeloperoxidase and elastase activity in Pg-injected rats were significantly reduced both in the conditioned medium of AAA tissue samples and in plasma of rats injected with Pg and treated with AZD9668. CONCLUSIONS: AZD9668 treatment could therefore constitute a new therapeutic tool for treatment of AAA.

Thoracic aorta to femoral artery bypass allows secondary kidney transplantation in case of major iliac artery disease.

Iliac artery major calcifications can compromise kidney graft. First-performed prosthetic arterial bypass from the thoracic aorta to the femoral artery allows secondary kidney transplantation. Four patients were submitted to this procedure. No patient died during the postoperative period or the follow-up. The median time to receive a kidney graft after the arterial surgery was 24 months (4-52). The normalization of the sera creatinine level was 6.4 days (2-15). The median follow-up was 38 months (7-79). In our experience, using lateral side clamping of the descendant thoracic aorta during the proximal implantation of the arterial graft avoids bleeding and visceral abdominal ischemia. The secondary performed kidney graft is safe on a very available arterial conduit.

Axillofemoral bypass for kidney transplant protection during open repair of abdominal aortic aneurysm.

The need to treat an abdominal aortic aneurysm (AAA) in kidney transplanted patient is a rare event. To date, no method to protect the kidney during the aneurysm treatment has been identified as undeniably relevant. On the other hand, the advantage of endovascular treatment of the aneurysm (EVAR) is to avoid transplanted kidney injury. Unfortunately, EVAR is not always available leading to open repair and then aortic cross clamping. We report here 3 cases of AAA open repair in kidney transplanted patients using a temporary axillofemoral bypass to protect the renal function.

Aortoiliac elongation after endovascular aortic aneurysm repair.

BACKGROUND: Aortoiliac elongation after endovascular aortic aneurysm repair (EVAR) is not well studied. We sought to assess the long-term morphologic changes after EVAR and identify potentially modifiable factors associated with such a change. METHODS: An institutional review board-approved retrospective review was conducted for 88 consecutive patients who underwent EVAR at a single academic center from 2003 to 2007 and who also had at least 2 follow-up computed tomography angiograms (CTAs) available for review up to 5 years after surgery. Standardized centerline aortic lengths and diameters were obtained on Aquarius iNtuition 3D workstation (TeraRecon Inc., San Mateo, CA) on postoperative and all-available follow-up CTAs. Relationships to aortic elongation were determined using Wilcoxon rank-sum test or linear regression (Stata version 12.1, College Station, TX). Changes in length over time were determined by mixed-effects analysis (SAS version 9.3, Cary, NC). RESULTS: The study cohort was composed of mostly men (88%), with a mean age of (76 ± 8) and a mean follow-up of 3.2 years (range, 0.4-7.5 years). Fifty-seven percent of patients (n = 50) had devices with suprarenal fixation and 43% (n = 38) had no suprarenal fixation. Significant lengthening was observed over the study period in the aortoiliac segments, but not in the iliofemoral segments. Aortoiliac elongation over time was not associated with sex (P = 0.3), hypertension (P = 0.7), coronary artery disease (P = 0.3), diabetes (P = 0.3), or tobacco use (P = 0.4), but was associated with the use of statins (P = 0.03) and the presence of chronic obstructive pulmonary disease (P = 0.02). Significant aortic lengthening was associated with increased type I endoleaks (P = 0.03) and reinterventions (P = 0.03). Over the study period, 4 different devices were used; Zenith (Cook Medical Inc., Bloomington, IN), Talent (Medtronic, Minneapolis, MN), Aneuryx (Medtronic), and Excluder (W. L. Gore and Associates Inc., Flagstaff, AZ). After adjusting for differences in proximal landing zone, significant differences in aortic lengthening over time were observed by device type (P = 0.02). CONCLUSIONS: Significant aortoiliac elongation was observed after EVAR. Such morphologic changes may impact long-term durability of EVAR, warranting further investigation into factors associated with these morphologic changes.

Chimney stent graft for endovascular sealing of a pararenal aortic aneurysm.

Chimney endovascular aneurysm repair is still a controversial treatment of complex aortic aneurysms. Stent-graft patency and type-I endoleaks are the main challenges that temper this bailout technique. Endovascular aneurysm sealing (EVAS) consists of anchoring and sealing the device within the aneurysm sac. The first results are promising, even for adverse anatomy. We describe a case of EVAS for a pararenal aortic aneurysm associated with a chimney stent graft for the right renal artery. Wrapping the chimney stent graft inside endobags filled with polymer is expected to prevent gutters and stent compressions.

Open aortic repair up to previous abdominal aortic surgery.

BACKGROUND: To determine whether direct open repair of thoracoabdominal aortic aneurysms after previous abdominal aortic surgery is a safe option. METHODS: Ten patients were operated between January 2006 and January 2012. Mean age was 70 years (62-78 years). Four aneurysms (Crawford type III) were treated by firstly performed bypasses from the upper thoracic aorta to the celiac trunk, the superior mesenteric artery, and the left renal artery. Secondly performed aortic repair included revascularization of intercostal arteries identified as critical for spinal cord and the right renal artery. Similarly, the 6 aneurysms (Crawford type IV) were treated by firstly performed bypass from the upper thoracic aorta to the left renal artery before aortic repair. RESULTS: The overall mortality and paraplegia rates were nil. The maximal creatinin sera variation was 48 ± 16% with return to the baseline level before discharge. Five patients presented with pulmonary complications. The duration of stay was 9.3 days (2-29) in the intensive care unit and 24 days (10-40) in the surgical unit. The mean follow-up was 35 months. No patient died during the follow-up. CONCLUSIONS: In our experience, open redo aortic surgery appears to be safe. The main relevant point is the sequential reconstruction of the aorta including bypasses of the visceral branches that lowered the visceral ischemic damage because of high level aortic cross-clamping.

Fucoidan interferes with Porphyromonas gingivalis-induced aneurysm enlargement by decreasing neutrophil activation.

PURPOSE: Neutrophils have been shown to be involved in all stages of human and experimental abdominal aortic aneurysm (AAA) development. The initial processes of neutrophil rolling and trapping in the intraluminal thrombus (ILT) are mediated mainly by P-selectin expressed by activated platelets. In the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the ILT induced by repeated episodes of weak bacteremia. METHODS: Sixty Lewis rats with experimental AAAs, developed from decellularized aortic xenografts, were divided into four groups. Two groups were used as controls: group fucoidan control (FC) was treated with 200 mg of fucoidan (F) delivered by 2 mL, 4-week osmotic pumps placed intraperitoneally before closing the abdomen, and group C received saline instead of fucoidan. Two more groups were injected weekly with Porphyromonas gingivalis (P. gingivalis [Pg]): group F+Pg received 200 mg of intraperitoneal fucoidan and group Pg received saline. AAAs were harvested after 4 weeks and peripheral blood was sampled at that time. Cell-free DNA (cf-DNA) and myeloperoxydase (MPO) antigen concentrations were determined in plasma and in AAA-conditioned media. Histology and P-selectin immunostaining were performed on AAA tissue samples. RESULTS: Comparing rats injected with Pg, those receiving fucoidan presented reduced aneurysmal diameter. Histologic analysis of AAAs showed that fucoidan reduced the ILT thickness in Pg-injected rats, with fewer trapped neutrophils, and with signs of a healing process, as observed in control group C. Immunohistological analysis revealed a substantial decrease in P-selectin immunostaining at the luminal surface of aneurysms in fucoidan-treated rats compared to the other groups, suggesting an interaction between fucoidan and P-selectin. A significant decrease in MPO concentrations in both plasma and conditioned medium was induced by fucoidan treatment in Pg-injected rats, reflecting a pacification of the ILT biological activity. This effect was associated with a reduction in neutrophil activation and apoptosis, reflected by a significant decrease in cf-DNA concentration in both plasma and conditioned medium of fucoidan-treated rats. CONCLUSIONS: Our results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration by decreasing neutrophil activation in the ILT enhanced by weak pathogen contamination. This effect seems to be related to its interaction with P-selectin, which may decrease the trapping of neutrophils into the ILT. Fucoidan could represent a therapeutic option in AAAs to decrease the neutrophil activation involved in the degenerative process of aneurysmal expansion and rupture.

Post-EVAR Thrombus Density on Late Non-Contrast CT Scans Predicts Successful Aneurysm Exclusion.

PURPOSE: The incidence of type II endoleaks (ELII) after endovascular aneurysm repair (EVAR) ranges from 10-44%. Aneurysm thrombus density after EVAR could predict successful aneurysm exclusion. MATERIALS AND METHODS: Twenty-seven patients with an abdominal aortic aneurysm (AAA) who had a CT scan within the first 45 days (early group) post-surgery or after 7 months (late group) were included. Thrombus density was analyzed on non-contrast enhanced CT scans. RESULTS: A total of 5/13 (38%) patients in the early group had an ELII and 9/14 (64.3%) in the late group had a persistent ELII since surgery. In the early group, thrombus density was similar in patients with or without an ELII (mean: 39.9 ± 4.8 vs. 41.9 ± 3.4, p = 0.7; median: 38.7 ± 4.8 vs. 39.7 ± 3.1, p = 0.8). In patients with an ELII, there was no difference in thrombus density at 45 days and after 7 months (mean: 39.9 ± 4.8 vs. 40.2 ± 2.1, p = 0.9; median: 38.7 ± 4.8 vs. 38 ± 2.6, p = 0.9). In patients without an ELII, thrombus density was significantly higher at 45 days than after 7 months (mean: 41.9 ± 3.44 vs. 25.7 ± 2.0, p = 0.005; median: 39.7 ± 3.11 vs. 24.4 ± 1.5, p = 0.004). In patients with an ELII, thrombus density was significantly higher after 7 months than in patients without an ELII (mean: 40.2 ± 2.1 vs. 25.7 ± 2.0. p = 0.001; median: 38 ± 2.6 vs. 24.4 ± 1.5, p = 0.003). CONCLUSION: Low thrombus density after EVAR on late unenhanced CT scans predicts aneurysm exclusion.

Combined retrograde stent-graft placement and surgical repair for a Stanford type A aortic dissection.

PURPOSE: To report a case of retrograde acute Stanford type A aortic dissection treated without hypothermic circulatory arrest. CASE REPORT: A 55-year-old man presented with a retrograde acute type A aortic dissection with an entry tear 30 mm below the left subclavian artery. A concurrent emergent endovascular and surgical treatment was performed, excluding the entry tear with retrograde delivery of a stent-graft and replacing the ascending aorta with a Dacron tube without circulatory arrest. CONCLUSION: Avoiding hypothermic circulatory arrest was the main advantage of this hybrid therapeutic choice. This combined technique may be of interest in acute retrograde type A dissections that present complications such as impending rupture or visceral malperfusion. A close collaboration between endovascular specialists and cardiac surgeons is essential for such a hybrid strategy.

High-density lipoprotein therapy inhibits Porphyromonas gingivalis-induced abdominal aortic aneurysm progression.

Clinical and experimental studies have highlighted the potential implication of periondontal bacteria contamination in the pathogenesis of abdominal aortic aneurysms (AAA). In addition to their role in reverse cholesterol transport, high-density lipoproteins (HDLs) display multiple functions, including anti-inflammatory and lipopolysaccharide scavenging properties. Low plasma levels of HDL-cholesterol have been reported in AAA patients. We tested the effect of a HDL therapy in Sprague-Dawley rat model of AAA, obtained by intraluminal elastase infusion followed by repeated injections of Porphyromonas gingivalis (Pg). HDLs, isolated by ultracentrifugation of plasma from healthy human volunteers, were co-injected intravenously (10 mg/kg) with Pg (1.107 Colony Forming Unit) one, eight and 15 days after elastase perfusion. Rats were sacrificed one week after the last injection. Our results show that Pg injections promote the formation of a persistent neutrophil-rich thrombus associated with increased aortic diameter in this AAA model. HDLs significantly reduced the increased AAA diameter induced by Pg. Histology showed the onset of a healing process in the Pg/HDL group. HDL injections also reduced neutrophil activation in Pg-injected rats associated with decreased cytokine levels in conditioned media and plasma. Scintigraphic analysis showed an intense uptake of 99mTc-HDL by the AAA suggesting that HDLs could exert their beneficial effect by acting directly on the thrombus components. HDL supplementation may therefore constitute a new therapeutic tool for AAA treatment.

A new murine model of endovascular aortic aneurysm repair.

Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of Abdominal aortic aneurysm (AAA) pathophysiology. There is no abdominal aortic aneurysm endograft exclusion model cheap and reproducible, which would allow deep investigations of AAA before and after treatment. We hereby describe how to induce, and then to exclude with a covered coronary stentgraft an abdominal aortic aneurysm in a rat. The well known elastase induced AAA model was first reported in 1990(1) in a rat, then described in mice(2). Elastin degradation leads to dilation of the aorta with inflammatory infiltration of the abdominal wall and intra luminal thrombus, matching with human AAA. Endovascular exclusion with small covered stentgraft is then performed, excluding any interactions between circulating blood and the aneurysm thrombus. Appropriate exclusion and stentgraft patency is confirmed before euthanasia by an angiography thought the left carotid artery. Partial control of elastase diffusion makes aneurysm shape different for each animal. It is difficult to create an aneurysm, which will allow an appropriate length of aorta below the aneurysm for an easy stentgraft introduction, and with adequate proximal and distal neck to prevent endoleaks. Lots of failure can result to stentgraft introduction which sometimes lead to aorta tear with pain and troubles to stitch it, and endothelial damage with post op aorta thrombosis. Giving aspirin to rats before stentgraft implantation decreases failure rate without major hemorrhage. Clamping time activates neutrophils, endothelium and platelets, and may interfere with biological analysis.