Endothelialization of PTFE-covered stents for aneurysms and arteriovenous fistulas created in canine carotid arteries

To investigate the endothelialization of covered and bare stents deployed in the canine carotid arteries and subclavian arteries for treating experimental aneurysms and arteriovenous fistulas, twenty aneurysms were created in 10 dogs, and 20 fistulas in another 10 dogs. The Willis balloon-expandable covered stent and a self-expandable covered stent were used to treat these lesions, and a self-expandable bare stent was deployed in the subclavian artery for comparison. Followed up for up to 12 months, the gross observation, pathological staining, and scanning electronic microscopic data were analyzed. Two weeks after creation of animal model, thirty self-expandable covered stents and ten balloon-expandable covered stents were deployed. Fifteen bare stents were deployed within the left subclavian arteries. Twenty days after stenting, the aneurysm significantly shrank. At 6 months, the thrombi within the aneurysm cavity were organized. Three to 12 months later, most covered and bare stents were covered by a thin transparent or white layer of endothelial intima. Layers of intima or pseudomembrane were formed on the stent 20-40 days after stent deployment. Over three months, the pseudomembrane became organized, thinner, and merged into the vascular wall. Under scanning electronic microscopy, the surface of covered and bare stents had only deposition of collagen fibers and rare endothelial cells 20-40 days after stenting. From three to ten months, the endothelial cells on the internal surface of stent became mature, with spindle, stripe-like or quasi round morphology along the blood flow direction. Over time, the endothelial cells became mature. In conclusion, three months after deployment in canines' arteries, the self-expandable bare and covered stents have mostly been covered by endothelial cells which become maturer over time, whereas the balloon-expandable covered stents do not have complete coverage of endothelial cells at three months, especially for protruding stent struts and areas. Over time, the endothelialization will become mature.

Traumatic iliac vein rupture managed using a bare-metal stent

Iliac vein rupture resulting from blunt trauma is rare but can be fatal and challenging to diagnose despite thorough clinical investigation and image workup. Here, we present a case of traumatic iliac vein rupture managed by emergent endovascular repair using a bare-metal stent. Low pressure traumatic venous rupture is different from arterial rupture, and a bare-metal stent can be a sufficient tool to control bleeding.

Results Obtained with the Protege EverFlex Self-expanding Bare Stent in Interventional Treatment of Spontaneous Isolated Visceral Artery Dissection

OBJECTIVE

We evaluated the early and midterm results of the endovascular approach with a certain type of bare stent to treat spontaneous isolated visceral artery dissection (SIVAD).

METHODS

28 patients with symptomatic SIVAD were selected from two hospitals from July 2014 to September 2020. All patients had symptoms of acute persistent abdominal pain accompanied by varying degrees of nausea and vomiting. The diagnosis of SIVAD was made according to the multidetector CT angiography (CTA) findings. We retrospectively analyzed the patients' medical records. According to our previous clinical experience, the Protege EverFlex self-expanding bare stent was used in these patients, and we subsequently followed up the patients to record and analyze their outcomes after surgery. The imaging results before and after the operations were compared.

RESULTS

All 28 patients were successfully implanted with Protege EverFlex stents. The true lumen blood flow of the SIVAD recovered during the operation. The residual stenosis rate was less than 30%, and the technical success rate was 100%. There were no complications, such as bleeding, intestinal necrosis, digestive tract perforation, liver failure or spleen infarction. The abdominal pain was relieved or eliminated in all patients.

CONCLUSION

The Protege EverFlex self-expanding bare stent and the endovascular approach could be a minimally invasive, safe and effective treatment method for SIVAD with a high success rate and a relatively low price.

Successful application of the snare technique for the deployment of the proximal portion of a Zenith Alpha Thoracic Endovascular Graft: a case report

BACKGROUND

Open surgery can be required or even fatal if incomplete deployment of stent graft (SG) occurs. We herein report the first case in which a snare was successfully used to perform endovascular therapeutic troubleshooting on the proximal portion of a Zenith Alpha thoracic endovascular graft proximal component that showed incomplete deployment.

CASE PRESENTATION

The patient was an 80-year-old woman. She underwent thoracic endovascular aortic repair (TEVAR) for subacute phase Stanford type B ulcer-like projection aortic dissection. Although the ulcer-like projection disappeared, a follow-up computed tomography angiogram (CTA) obtained approximately 1 year postoperatively showed type Ia and Ib endoleaks. Since there is a high risk of rupture as the aneurysm diameter increases, we determined that an additional SG was indicated. An attempt was made to place the SG in Zone 3, but as the lesser curvature side of the proximal portion stopped in a position that was perpendicular to the vascular wall (downward facing), the SG proximal portion did not completely expand. A guiding sheath was inserted into the aortic arch via the left brachial artery, and, using a snare that we inserted via the femoral artery, we grasped the guiding sheath. A catheter and guidewire (GW) were inserted via the guiding sheath and then rotated under the lesser curvature of the SG proximal portion; the GW was then passed through the loop of the snare. This allowed us to insert the hard loop structure under the SG proximal portion, which in turn allowed successful repair of the incomplete deployment of the SG. Type Ia and Ib endoleaks remained but were less than those before additional TEVAR. One week later, she was discharged. One year later, CT showed no interval change in the size of aortic aneurysm with dissection, and she has been followed on an outpatient basis.

CONCLUSIONS

When the endovascular diameter of the proximal aortic arch is large, incomplete deployment of the proximal portion of a Zenith Alpha thoracic endovascular graft can occur, but bailout is possible through the use of the snare technique as endovascular therapy.

Placement of a Zenith® Dissection Endovascular System in the Descending Thoracic Aorta Can Hamper Further Surgical Aortic Operations

Introduction

The efficacy of endovascular treatment for complicated Stanford type B acute aortic dissection is being established. However, aortic events sometimes occur, and some cases require surgical intervention.

Report

A 52 year old man underwent ascending aorta replacement for Stanford type A acute aortic dissection in August 2016. Post-operative computed tomography (CT) showed residual dissection from the aortic arch to the right common iliac artery and a large re-entry in the right common iliac artery (RCIA). Two months after the operation, CT revealed enlargement of the false lumen of the thoracic aorta and the thoracic aortic diameter. Aiming to reduce the false lumen and remodel the aorta, a three stage operation was performed, as described below. Four months after the dissection, total aortic arch replacement and a frozen elephant trunk insertion were performed as the first stage. Subsequently, as a second stage operation, thoracic endovascular repair (TEVAR) was performed using a Zenith® Dissection Endovascular System (Cook Japan Co., Ltd, Tokyo, Japan), with the aim of expanding the true aortic lumen. The implanted devices were a stent graft for the proximal part and two bare stents for the middle and distal part. As a third stage operation, abdominal aortic endovascular treatment was performed with the purpose of closing the re-entry from the RCIA. However, two years after the three stage operation, CT showed that the thoracic aorta was over 60 mm in diameter. Graft replacement of the thoraco-abdominal aorta was performed. The bare stents were expected to be easily removable from the aorta, but unexpectedly, they were strongly attached to the intima, which made it extremely difficult to perform surgical and aortic operations.

Discussion

Surgical operations for the aorta can become more difficult after bare stent placement in the aorta.

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Surgical operations on the aorta can be hampered after intra-aortic bare stent placement.

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The bare stents and the intima of the true lumen were integrated.

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Operability seemed to be relatively smooth when the electric cautery was operated at a high output.

A meta-analysis of combined proximal stent grafting with or without adjunctive distal bare stent for the management of aortic dissection

BACKGROUND

The efficacy and safety of placement of a proximal covered stent graft combined with a distal bare stent are controversial because of the lack of evidence. This systematic review and meta-analysis compared the outcomes of combined proximal covered stent grafting with distal bare stenting (BS group) and proximal covered stent grafting without distal bare stenting (non-BS group).

METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases and key references were searched up to January 26, 2019. Predefined outcomes of interest were mortality, morbidity, and postoperative assessment of aortic remodeling. We pooled risk ratios (RRs) of the outcomes of interest using fixed effects model or random effects model.

RESULTS

Overall, eight observational studies involving 914 patients were included. There were no significant differences in overall aorta-related mortality (RR, 0.54; confidence interval [CI], 0.24-1.24; P = .15), complete thoracic false lumen (FL) thrombosis rate (RR, 1.23; CI, 0.83-1.81; P = .30), or complete abdominal FL thrombosis rate (RR, 1.96; CI, 0.68-5.69; P = .21) between the BS group and the non-BS group. The BS group had a lower rate of partial thoracic FL thrombosis (RR, 0.40; CI, 0.25-0.65; P = .0002), a lower stent graft-induced new entry rate (RR, 0.08; CI, 0.02-0.41; P = .003), and a lower reintervention rate (RR, 0.42; CI, 0.26-0.69; P = .0005).

CONCLUSIONS

Combined proximal covered stent grafting with distal adjunctive bare stenting had the potential to reduce the partial thoracic FL thrombosis rate and the rates of stent graft-induced new entry and reintervention but was not associated with lower aorta-related mortality or the complete FL thrombosis rate. Further research with a stricter methodology is needed.

Thoracic endovascular aortic repair with stent grafts alone or with a composite device design in patients with acute type B aortic dissection in the setting of malperfusion

OBJECTIVE

The objective of this study was to compare short-term outcomes in patients who underwent thoracic endovascular aortic repair (TEVAR) with stent grafts alone or with a composite device design (stent graft plus bare-metal aortic stent) for acute type B aortic dissection in the setting of malperfusion.

METHODS

This retrospective analysis included patients with acute (≤14 days of symptom onset) complicated type B dissection in the setting of malperfusion who were treated with stent grafts alone (TEVAR cohort) at two European institutions vs those who underwent TEVAR with a composite device design (Cook Medical, Bloomington, Ind) in the investigational STABLE I feasibility study and STABLE II pivotal study (STABLE cohort). Preoperative characteristics and 30-day outcomes (including mortality, malperfusion-related mortality, morbidity, and secondary interventions) were compared between the two groups.

RESULTS

The TEVAR cohort (41 patients; mean age, 58.8 ± 12.7 years; 78.0% male) and the STABLE cohort (84 patients; mean age, 57.8 ± 11.7 years; 71.4% male) were largely similar in preoperative medical characteristics, with more STABLE patients presenting with a history of hypertension (79.8% vs 58.5%; P = .018). The TEVAR and STABLE groups had similar lengths of dissection (451.8 ± 112.7 mm vs 411.8 ± 116.4 mm; P = .10) and similar proximal and distal extent of dissection. At presentation, the two groups exhibited comparable organ system involvement in malperfusion: renal (53.7% TEVAR, 57.1% STABLE), gastrointestinal (41.5% TEVAR, 44.0% STABLE), lower extremities (34.1% TEVAR, 52.4% STABLE), and spinal cord (9.8% TEVAR, 2.4% STABLE). The 30-day rate of all-cause mortality was 17.1% (7/41) in the TEVAR group and 8.3% (7/84) in the STABLE group (P = .22). The 30-day rate of malperfusion-related mortality (deaths from bowel/mesenteric ischemia or multiple organ failure) was 12% (5/41) in the TEVAR group and 2.4% (2/84) in the STABLE group (P = .038). The 30-day morbidity, for the TEVAR and STABLE groups, respectively, included bowel ischemia (9.8% [4/41] vs 2.4% [2/84]; P = .09), renal failure requiring dialysis (7.3% [3/41] vs 9.5% [8/84]; P > .99), paraplegia or paraparesis (4.9% [2/41] vs 3.6% [3/84]; P = .66), and stroke (2.4% [1/41] vs 10.7% [9/84]; P = .16). The occurrence of 30-day secondary intervention was similar in the TEVAR and STABLE groups (7.3% [3/41] vs 7.1% [6/84]; P > .99). True lumen expansion in the abdominal aorta was significantly greater in the STABLE group.

CONCLUSIONS

In patients with acute type B aortic dissection in the setting of branch vessel malperfusion, the use of a composite device with proximal stent grafts and distal bare aortic stent appeared to result in lower malperfusion-related mortality than the use of stent grafts alone. The 30-day rates of morbidity and secondary interventions were similar between the groups.

Aortic Dissection Repair Using the STABILISE Technique Associated with Arch Procedures: Report of Two Cases

Introduction

The stent assisted balloon induced intimal disruption and relamination in aortic dissection repair (STABILISE) technique is being increasingly used for the treatment of complicated aortic dissections. However, as it is a fairly recent technique, the scientific information is limited.

Report

In this paper we report two cases of the STABILISE technique associated with procedures in the ascending aorta and supra-aortic trunks, consisting of a “frozen elephant trunk” procedure in one case and in the other, a carotid endarterectomy associated with reimplantation of the vertebral artery and partial arch debranching.

Discussion

In conclusion, while acknowledging the need for longer follow up and greater experience to support the safety and efficacy of this procedure, the two cases reported confirm that the STABILISE technique is a valid endovascular alternative in the treatment of complicated aortic dissections.

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Two cases of complicated aortic dissection treated using the STABILISE technique.

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Both cases have another feature related to the need for associated aortic arch procedures.

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As it is a fairly recent technique, the scientific information about this technique is limited.

Association of high level of hs-CRP with in-stent restenosis: A case-control study

BACKGROUND

In-stent restenosis (ISR) is one adverse outcome of coronary stent implantation. Although using drug-eluting stents has reduced the rate of ISR, it remains a major problem. Here, we have investigated the relationship between several patient characteristics including serum high sensitive C-reactive protein (hs-CRP) and ISR.

METHODS

This was a case-control study comprising 104 individuals with ISR and 202 patients without. Baseline characteristics were collected using a questionnaire. Fasting blood glucose (FBG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and serum high sensitivity C-reactive protein (hs-CRP) were measured using commercial kits on an auto-analyzer. Data were analyzed using SPSS software and a p value ≤ 0.05 was considered significant.

RESULTS

Diabetes mellitus (p < 0.001), stent type (p = 0.005), serum hs-CRP (p = 0.006), FBG (p = 0.038) and serum TG (p = 0.039) were significantly associated with ISR. The association between hs-CRP and ISR remained significant after adjustment for stent type and DM. For patients with a serum hs-CRP <2.64 mg/dL, ISR was only associated with diabetes mellitus (p = 0.016); while for individuals with a serum hs-CRP ≥2.64 mg/dL, ISR was also associated with the presence of diabetes mellitus, serum triglycerides and stent type.

CONCLUSION

Higher levels of serum hs-CRP were significantly associated with the occurrence of ISR.

Transjugular Intrahepatic Portosystemic Shunt in Patients with Portal Hypertension: Patency Depends on Coverage and Interventionalist's Experience

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic shunt (TIPS) is the treatment of choice in decompensated portal hypertension. TIPS revision due to thrombosis or stenosis increases morbidity and mortality. Our aim was to investigate patient- and procedure-associated risk factors for TIPS-revision.

PATIENTS AND METHODS

We retrospectively evaluated 189 patients who underwent the TIPS procedure. Only patients who required TIPS revision within 1 year (Group I, 34 patients) and patients who did not require re-intervention within the first year (Group II [control group], 54 patients) were included.

RESULTS

Out of 88 patients, the majority were male (69.3%) and mean age was 56 ± 11 years. Indications for TIPS were refractory ascites (68%), bleeding (24%), and Budd-Chiari syndrome (8%). The most frequent liver disease was alcohol-induced cirrhosis (60%). Forty-three patients (49%) received bare and 45 patients (51%) covered stents, thus resulting in reduction of hepatic venous pressure gradient (HVPG) from 19.0 to 9.0 mm Hg. When comparing patient- and procedure-related factors, the type of stent (p < 0.01) and interventionalist's experience (number of performed TIPS implantations per year; p < 0.05) were the only factors affecting the risk of re-intervention due to stent dysfunction, while age, gender, indication, Child-Pugh, and model of end-stage liver disease score, platelet count, pre- and post-HVPG, additional variceal embolization, stent diameter, and number of stents did not significantly differ.

CONCLUSION

Patients undergoing TIPS procedure should be surveilled closely for shunt dysfunction while covered stents and high-level experience are associated with increased -patency.