Enrico Gallitto

Commentary on: "could four dimensional contrast-enhanced ultrasounds replace computed tomography angiography during follow-up of fenestrated endografts? Results of a preliminary experience".

OBJECTIVE To evaluate four-dimensional contrast-enhanced ultrasound (4D-CEUS) as an alternative imaging method to computed tomography angiography (CTA) during follow up of fenestrated endovascular aneurysm repair (FEVAR) for juxta- and para-renal abdominal aortic aneurysms (AAA). METHODS Between October 2011 and March 2012, all consecutive patients who underwent FEVAR follow up were included in the study and evaluated with both 4D-CEUS and CTA. The interval between the two examinations was always ≤ 30 days. Endpoints were the comparison of postoperative AAA diameter, AAA volume, presence of endoleaks, revascularized visceral vessel (RVV) visualization, and patency. Comparative analysis was performed using Bland-Altman plots and McNemars Chi-square test. RESULTS Twenty-two patients (96% male, 4% female; mean age 74 ± 7 years; American Society of Anesthesiologists grade III/IV 82%/18%) were enrolled. Seventy-eight RVV (fenestrations: 60; scallops: 17; branches: 1) were analyzed. The mean AAA diameter evaluated by 4D-CEUS and CTA was 45 ± 10 mm (range 30-69 mm) and 48 ± 9 mm (range 32-70 mm), respectively. The mean difference was 3 ± 3 mm. The mean AAA volume evaluated by 4D-CEUS and CTA was 150 ± 7 cc (range 88-300 cc) and 159 ± 68 cc (range 80-310 cc), respectively. The mean difference was 7 ± 4 cc; a Bland-Altman plot revealed agreement in AAA diameter and volume evaluation (p < .01) between 4D-CEUS and CTA. The observed agreement for the detection of endoleaks was 95%. McNemars Chi-square test confirmed that 4D-CEUS and CTA were equivalent (p > .05) at detecting endoleaks. The first segment of six (8%) RVVs (four renal and two superior mesenteric arteries) was not directly visualized by 4D-CEUS owing to obesity, but the contrast enhancement into the distal part of vessel or into the relative parenchyma gave indirect information about their patency. McNemars Chi-square test demonstrated the superiority of CTA (p = .031) in visualizing RVVs. The patency of 77/78 RVVs was confirmed with both techniques. McNemars Chi-square test confirmed that 4D-CEUS and CTA were equivalent in their ability to detect visceral vessel patency. CONCLUSIONS The data suggest that 4D-CEUS is as accurate as CTA in the evaluation of postoperative AAA diameter and volume, endoleak detection, and RVV patency after FEVAR. Four-dimensional CEUS could provide hemodynamic information regarding RVVs, and reduce radiation exposure and renal impairment during follow up. Obesity limits the diagnostic accuracy of 4D-CEUS.

Follow-up outcomes of hybrid procedures for thoracoabdominal aortic pathologies with special focus on graft patency and late mortality

OBJECTIVE The purpose of this study was to analyze midterm results of bypass patency and overall and aortic-related mortality rates of hybrid aortic procedures for thoracoabdominal aortic pathologies. METHODS A retrospective study was performed considering prospectively collected data in two centers. From January 2001 to December 2012, 45 patients (33 men; mean age, 67.8 ± 7.6 years) received hybrid aortic procedures for thoracoabdominal aortic diseases (31 atherosclerotic aneurysms, 7 chronic expanding type B aortic dissections, 2 penetrating aortic ulcers, and 5 pseudoaneurysms), corresponding to 155 revascularized visceral abdominal arteries. Elective/emergency and staged/simultaneous approaches were 31 of 14 and 28 of 17, respectively. Patient demographics, clinical risk factors, and aortic morphological and procedural data were collected. End points were technical success, 30-day morbidity, reintervention and mortality, bypass graft patency, freedom from reintervention, and overall and aortic-related mortality during midterm follow-up. Mean follow-up was 2.2 ± 2.4 years. RESULTS Technical success was achieved in 86.6% (39/45) of patients. Thirty-day morbidity rate was 60% (paraplegia/paraparesis: 13.3%, stroke: 6.7%, renal failure: 31.3%, permanent dialysis: 4.4%). Thirty-day freedom from reintervention rates were 67.1% and 78.5%, respectively. Thirty-day occlusion of revascularized visceral vessels occurred in 11 (7.1%, 11/155) target arteries. In-hospital mortality rate was 24.4%. Primary graft patency after 1, 2, and 4 years was 89.7%, 85.3%, and 79%, respectively. Bypass thrombosis or stenosis developed in nine (6.8%, 9/132) vessels during follow-up. Of these, three patients required reintervention and one died. Freedom from reintervention rates after 1, 2, and 4 years were 45.6%, 45.6%, and 34.2%, respectively. Overall and aortic-related mortality rates after 1, 2, and 4 years were 32.6%, 41.4%, and 45.3% and 9.1%, 13.9%, and 13.9%, respectively. CONCLUSIONS A hybrid procedure for thoracoabdominal aortic pathologies in high-risk patient is feasible but carries a significant rate of early and midterm reintervention and death. Long-term surveillance of the visceral bypass is necessary because one-third of the patients will have bypass-related complications.

Fenestrated and Branched Endograft after Previous Aortic Repair

BACKGROUND Para-anastomotic aneurysms (P-AAA) and proximal aortic aneurysmal degeneration after previous aortic open repair (OR) or endovascular repair (EVAR) are challenging clinical scenarios. OR is technically demanding, and standard EVAR could be impossible due to the absence of proximal landing zone. The aim of the study is to report midterm results of fenestrated and branched endografts (FB-EVAR) to treat proximal aortic lesions after previous aortic repair. METHODS Since 2010, patients that underwent FB-EVAR after previous aortic repair were prospectively enrolled. Clinical or morphologic or intraoperative or postoperative data were collected and retrospectively analyzed. Primary end points were technical success and clinical success. Secondary end points were procedure-related events (endoleaks, target visceral vessels occlusion, mortality), midterm survival and freedom from FB-EVAR-related reinterventions. RESULTS Twenty patients (Male: 98%, age: 75 ± 6 years, American Society of Anesthesiologists [ASA] ≥ III: 100%) were enrolled. Fifteen patients (75%) underwent previous aortic OR and 5 (25%) standard EVAR. The mean time since the previous treatment was 12 ± 10 years. Present aortic lesions included thoracoabdominal aneurysms 12 (60%) and juxtarenal and pararenal aneurysms 8 (40%). The mean aortic aneurysm diameter was 67 ± 15 mm. All patients were at high risk for OR and had anatomies precluding standard EVAR. Seventy-two visceral vessels (renal arteries: 34, superior mesenteric artery: 20, celiac trunk: 18) were targeted: 49 fenestrations, 19 branches, and 4 scallops. An FB-EVAR tube and trimodular endograft was planned in 17 and 3 cases, respectively. Technical success was 95%; operative target vessel perfusion was 98.5%. Thirty-day mortality was 0%. Clinical success was 80% because there was a transient renal function worsening in 4 patients (>30% of baseline). One distal type I endoleak was detected and treated at 1-month. The mean follow-up was 15 ± 11 months. There were not proximal type I endoleaks, target visceral vessel occlusions, or aneurismal-related mortality. Survival at 1 year was 85 ± 5%. One late FEVAR-related reintervention occurred. CONCLUSIONS According to the reported data, FB-EVAR for treating P-AAA or proximal aneurysmal degeneration after previous aortic OR/EVAR in high-risk patients is a safe and/or effective solution.

Adjunctive stenting of endograft limbs during endovascular treatment of infrarenal aortic and iliac aneurysms according to 3-projection completion angiography.

Purpose To evaluate the role of 3-projection completion angiography in defining endograft limb stenosis after endovascular aneurysm repair (EVAR) and to determine the role of adjunctive stenting in reducing the risk of endograft limb occlusion. Methods In our center, stent-graft limb dilation was routinely done after endograft deployment in patients with preoperatively identified severe iliac axis angulation to reduce the incidence of limb stenosis. Completion angiography was then routinely performed in anteroposterior (AP) and 45° right and left oblique projections to identify perioperative endograft limb stenosis after the stiff guidewires were removed. Adjunctive stenting was used in iliac limbs with postangioplasty residual stenosis >50%. From January 2005 to November 2010, 302 EVAR patients (296 men; mean age 74.25±7.04 years, range 53–90) with 589 stent-graft limbs (aortomonoiliac stent-graft in 15 patients) who had a minimum 6 months of follow-up and a nonstenotic aortic bifurcation were selected for this study. Patient demographics, clinical risk factors, iliac anatomical features, procedure data, and limb patency were analyzed. Primary endpoints were the incidence of limb stenosis >50% and any associated risk factors; the secondary endpoint was the primary patency of stent-graft limbs with adjunctive stenting. Results On 3-projection completion angiography, 40 (6.8%) limbs presented limb stenosis and were treated with adjunctive stenting; in only 28 (70%) of these cases was the >50% limb stenosis evident on the AP view. According to the degree of preoperative iliac angulation, limb stenosis occurred in mild (<60°), moderate (60°–89°), and severe (≥90°) angulations in 14 (4.6%), 9 (5.6%), and 17 (13.4%) cases, respectively; positive predictors for limb stenosis were severe iliac artery angulation [vs. moderate (p=0.02) and mild (p=0.001)] and stent-graft limb diameter <16 mm (p=0.02). In the adjunctive stenting group, the mean follow-up was 16.1 months; no graft occlusion, graft erosion, or restenosis was seen during follow-up (100% primary patency at 12 and 24 months). Conclusion Three-projection completion angiography is crucial to identifying limb stenosis, for which adjunctive stenting appears to ensure primary patency in midterm follow-up. Preoperative iliac artery angulation and small endograft limb diameter are positive prognostic factors for limb stenosis >50%.

Human Vascular Wall Mesenchymal Stromal Cells Contribute to Abdominal Aortic Aneurysm Pathogenesis Through an Impaired Immunomodulatory Activity and Increased Levels of Matrix Metalloproteinase-9.

BACKGROUND The main histopathological features of abdominal aortic aneurysm (AAA) are tissue proteolysis mediated by matrix metalloproteinases (MMPs) and inflammation. This study aimed at verifying the presence and contribution of mesenchymal stromal cells (MSCs) to aneurysmal tissue remodeling. METHODS AND RESULTS MSCs were successfully isolated from the AAA wall of 12 male patients and were found to express mesenchymal and stemness markers. MMP-2/-9 are involved in AAA progression and their mRNA levels in AAA-MSCs resulted higher than healthy MSCs (cMSCs), especially MMP-9 (400-fold increased). Moreover, MMP-9 protein and activity were pronounced in AAA-MSCs. Immunomodulation was tested in AAA-MSCs after co-culture with activated peripheral blood mononuclear cells (PBMCs) and revealed a weak immunosuppressive action on PBMC proliferation (bromodeoxyuridine incorporation, flow cytometry assay), together with a reduced expression of anti-inflammatory molecules (HLA-G, IL-10) by AAA-MSCs compared to cMSCs. MMP-9 expression in AAA-MSCs was shown to be negatively modulated under the influence of cMSCs and exogenous IL-10. CONCLUSIONS MSCs with stemness properties are niched in human AAA tissues and display a dysregulation of functional activities; that is, upregulation of MMP-9 and ineffective immunomodulatory capacity, which are crucial in the AAA progression; the possibility to modulate the increased MMP-9 expression by healthy MSCs and IL-10 suggests that novel therapeutic strategies are possible for slowing down AAA progression.

Off-the-shelf multibranched endograft for urgent endovascular repair of thoracoabdominal aortic aneurysms

Objective: The aim of this paper was to report early and midterm results of endovascular repair of urgent thoracoabdominal aortic aneurysms (TAAAs) by the off‐the‐shelf multibranched Zenith t‐Branch endograft (Cook Medical, Bloomington, Ind). Methods: Between January 2014 and April 2016, all patients with urgent TAAAs (asymptomatic with diameter >8 cm, symptomatic, or ruptured TAAAs) and aortoiliac anatomic feasibility underwent endovascular repair by t‐Branch and were prospectively enrolled. Clinical, morphologic, intraoperative, and postoperative data were recorded. Follow‐up was performed by duplex ultrasound, contrast‐enhanced duplex ultrasound, and computed tomography angiography. Early end points were technical success (absence of type I or type III endoleak, loss of target visceral vessels [TVVs], conversion to open repair, or 24‐hour mortality), spinal cord ischemia, and 30‐day mortality. Follow‐up end points were survival, TVV patency, type I or type III endoleaks, and freedom from reintervention. Results: Seventeen patients (male, 71%; age, 73 ± 6 years; American Society of Anesthesiologists class 3/4, 60%/40%) affected by type II (47%), III (29%), and IV (24%) TAAAs were enrolled. The indications for t‐Branch were as follows: contained TAAA rupture, four (24%); symptomatic TAAA (pain or peripheral embolism), four (24%); and TAAA diameter ≥8 cm, nine (52%). The mean TAAA diameter was 80 ± 19 mm, with 63 TVVs. Fifteen patients (87%) needed adjunctive intraoperative procedures: 14 proximal thoracic endografts (thoracic endovascular aortic repair), 1 left carotid‐subclavian bypass, 2 endovascular hypogastric branches, and 2 surgical iliac conduits. In four cases (24%), a significant malorientation (≥60 degrees) of the main body occurred during t‐Branch deployment. Technical success was achieved in 14 cases (82%), with technical failures consisting of the loss of three renal arteries (TVV patency, 95%). Spinal cord ischemia occurred in one case (6%) with temporary paraparesis. The 30‐day mortality was 6% (one patient with ruptured type II TAAA died on postoperative day 7 of respiratory failure). Renal function worsening occurred in four patients (25%), with one case requiring permanent hemodialysis. The mean follow‐up was 11 ± 9 months. Survival at 1 month, 6 months, and 12 months was 94%, 82%, 82%, respectively. No TAAA‐related mortality and TVV occlusion occurred in the follow‐up. One type III endoleak was detected at 3 months and successfully treated. Freedom from reintervention at 1 month, 6 months, and 12 months was 88%, 82%, and 82%, respectively. Conclusions: The off‐the‐shelf multibranched endograft is a safe and effective therapeutic option for urgent total endovascular TAAA repair for which a custom‐made endograft is not obtainable in due time. However, the complex anatomy of these aneurysms needs a number of adjunctive and complex intraoperative procedures to achieve a durable repair.

Influence of Statin Therapy on Type 2 Endoleak Evolution

BACKGROUND Endovascular repair (EVAR) for abdominal aortic aneurysm (AAA) is widely adopted; however, the procedure may be jeopardized by type 2 endoleak (T2E). Most T2Es regress over time, but their evolution is unpredictable. There is some evidence about the pleiotropic statin effect on AAA and thrombus stabilization, but there are no data on the influence of statins on T2E. The studys aim is therefore to evaluate a possible effect of statins on T2E evolution. METHODS A retrospective analysis of patients discharged from 2008 to 2013 with T2E after EVAR was performed. Patients were followed up with duplex ultrasound and computed tomography angiography and divided on statin and no statin users. The primary end point was to evaluate the T2E persistence at 6 months and during follow-up. The secondary end points were to compare the shrinkage (median and rate), the sac increasing rate, and reintervention at 6 months and during follow-up. RESULTS In the period examined, 756 EVARs were performed and 85 (11%) had T2E at discharge. Thirty-two (37%) patients with T2E were on statins. The median follow-up was 19 (interquartile range [IQR] 7) months. Statin and no statin patients had similar clinical and anatomical characteristics, endoprosthesis type, and medical therapy. At 6 months, patients on statins had lower T2E persistence ([26] 81% vs. [49] 93%, P = 0.16), reaching the significance at 36 months (11 ± 9% vs. 64 ± 7%, P = 0.001). By Cox analysis, statins are independently associated with T2E regression (hazard ratio 0.40, 95% confidence interval 0.020-0.81, P = 0.01), other characteristics are: >2 lumbar arteries or inferior mesenteric artery patency or oral anticoagulant therapy did not reduce T2E. At 6 months, statin patients had higher shrinkage rate and diameter reduction compared with no statin patients (18% vs. 3%, P = 0.03 and 11 mm (IQR 4) vs. 6 mm (IQR 4), P = 0.05, respectively). Freedom from growth diameter and reintervention rate were not significantly different (85 ± 9% vs. 81 ± 14%, P = 0.10 and 75 ± 17% vs. 37 ± 16%, P = 0.13, respectively). CONCLUSION Statin therapy seems to influence T2E regression and aortic sac stabilization after EVAR in the early medium follow-up; however, prospective studies need to confirm the present results.

Lower limb malperfusion in type B aortic dissection: a systematic review

BACKGROUND Lower limb malperfusion (LLM) syndrome occurs in up to 40% of complicated type B aortic dissections (TBAD) and in up to 71% of TBAD with malperfusion syndrome. This syndrome is associated with higher 30-day mortality. The aim of this systematic review was to provide clinical and procedural data of patients with LLM syndrome secondary to TBAD. METHODS The PubMed database was systematically searched from January 2000 to June 2014 for English-language publications reporting on demographic data of patients with LLM secondary to TBAD. RESULTS A total of 29 papers were included (10 original articles and 19 case reports), reporting on a total of 138 patients (mean age =58±12 years; male =87%). Lower limb complications developed in acute and chronic TBAD in 134 (97%) and 4 (3%) cases, respectively. LLM presented with acute limb ischemia in 120 (87%) patients. Bilateral clinical presentation occurred in 56% (40/72) of cases. LLM was the only clinically detected malperfusion in 52% of cases (44/84). In 40% (35/84) and 25% (21/84) of cases, LLM was clinically associated with renal and visceral malperfusion, respectively. Radiological imaging showed renal, celiac trunk and superior mesenteric artery involvement in 53% (47/88), 31% (27/88) and 34% (30/88) of cases, respectively. Medical, surgical and endovascular treatments were performed in 22 (16%), 51 (37%) and 65 (47%) patients, respectively. Thirty-day morbidity was 31% (13/42) and 46% (6/13) following surgical and endovascular treatment, respectively. Thirty-day mortality was 14% (5/36) and 8% (2/26) following surgical and endovascular treatment, respectively. CONCLUSIONS LLM syndrome secondary to TBAD usually developed during the acute phase and, in most cases, presented with acute limb ischemia. Bilateral clinical presentation occurred in more than half of cases. Renal and visceral malperfusion were frequently associated with lower limb flow reduction but LLM was the only clinically detected malperfusion in more than half of patients. Surgical fenestration was burdened with significant complication rates and 30-day mortality. Endovascular procedures showed lower mortality but complication rates remained high.

Impact of kidney ischemic lesions on renal function after fenestrated endovascular repair

OBJECTIVE Fenestrated endovascular aortic repair (fEVAR) is being used increasingly in the treatment of complex aortic aneurysms; however, this procedure can be associated with visceral and renal complications. Because the causes of possible renal function (RF) impairment have not been fully examined yet, we conducted a study to investigate whether there are risk factors associate with renal ischemic lesions (RILs) and if they influence RF in patients treated for complex aortic aneurysm with fEVAR. METHODS We evaluated the clinical, anatomic, and technical characteristics of consecutive patients treated with fEVAR from 2008 to 2014. RIL were identified by postoperative computed tomography angiography and the volume of renal parenchyma involved quantified. A decrease in RF (>30% glomerular filtration rate reduction) was evaluated at discharge, and at the 6- and 12-month follow-ups. RESULTS Among 53 patients, we analyzed 38 (72%) juxta/pararenal and 15 (28%) thoracoabdominal aortic aneurysms (33 [64%] with ≥3 fenestrations) and 102 renal arteries. Fifteen patients (30%) showed RIL, which was caused by accessory renal artery (ARA) coverage in 6 cases (38%), distal embolism in 6 (38%), renal artery thrombosis in 2 (18%), and iatrogenic embolization for intraoperative bleeding during fEVAR in 1 (6%). The volume of renal parenchyma involved was less than 25% in 10 (67%) and 25% to 50% in 5 (33%) cases. In no cases was more than 50% renal volume affected. On multivariate analysis, RIL predictors were the presence of ARA (odds ratio [OR], 8.00; 95% confidence interval [CI], 1.16-54.89; P = .03) and extensive thrombosis of the pararenal aorta (OR, 39.93; 95% CI, 3.36-474.23; P = .003). At discharge, chronic renal failure (CRF; OR, 4.80; 95% CI, 1.27-18.09; P = .01), diabetes (OR, 8.44; 95% CI, 1.33-53.51; P = .01), and extensive thrombosis of the pararenal aorta (OR, 5.50; 95% CI, 1.32-29.92; P = .01) were significantly associated with worsening RF. RIL, independent from volume, did not influence the postoperative RF. At 6 months and 1-year, preoperative CRF and perioperative declines in RF were identified as the only risk factors for worsening RF. CONCLUSIONS RIL is a common fEVAR complication and is primarily owing to ARA coverage and aortic thrombus embolization. However, RIL does not influence RF, which is predicted by preoperative CRF, diabetes, and extensive aortic thrombus.

Fenestrated endograft for recurrent paravisceral aortic pseudoaneurysm after thoracoabdominal aortic aneurysm open repair

Paravisceral aortic pseudoaneurysm is an uncommon late graft-related complication after thoracoabdominal aortic aneurysm open repair. The redo surgery and hybrid procedures are the treatments of choice, with significant perioperative morbidity and mortality rates. We report a total endovascular repair of a 56-mm paravisceral aortic pseudoaneurysm in a 65-year-old patient with a history of type V thoracoabdominal aortic aneurysm open repair and redo open procedure for a distal anastomotic pseudoaneurysm. The lesion was successfully treated with a custom-made four-fenestration endograft. At 18 months, the patient was asymptomatic without liver, renal, or pancreatic problems. Computed tomography angiography demonstrated the absence of endoleaks, the antegrade perfusion of visceral vessels, and the absence of stent graft fractures.