Early and mid-term results in the endovascular treatment of popliteal aneurysms with the multilayer flow modulator

Endoleak following endovascular repair of popliteal artery aneurysm: clinical outcome and contrast-enhanced ultrasound detection

BACKGROUND

Continued blood flow in the aneurysm sac after repair, also known as endoleak, can occur after both open and endovascular popliteal aneurysm repair (EPAR) with risk for aneurysm sac enlargement. Primary aims were to investigate aneurysm sac growth and the presence and classification of endoleak after EPAR using contrast-enhanced ultrasound (CEUS).

METHODS

Cross-sectional study of patients receiving EPAR with expanded polytetrafluorethylene (ePTFE) covered stent-grafts between 1^st of January 2009 and 1^st of February 2019 at a tertiary referral endovascular center. Patients were re-invited in 2021 and 31 legs were examined for endoleak using CEUS. Endoleaks were classified by a core-lab consisting of three CEUS-experienced physicians.

RESULTS

Median follow-up was 57 months (range 33-143 months). Endoleak was detected in 16 PAA, and categorized as type I (N.=3), type II (N.=10), type III (N.=1) or indeterminate (N.=2). Median maximal PAA diameter was 24 mm (range 15-55 mm) at the time of EPAR compared to 17 mm (range 6-43 mm) at follow-up (P<.001). Maximal aneurysm sac diameter was smaller at follow-up than at the index procedure in both PAAs with and without endoleak on CEUS (P=0.005 vs. P<0.001, respectively). There was no difference in PAA sac shrinkage at follow-up between patients with or without endoleak (P=0.28). Freedom from aneurysm sac growth was 97%.

CONCLUSIONS

CEUS was sensitive in endoleak detection after EPAR. Shrinkage of the PAA sac was found in both patients with and without endoleaks. CEUS appears useful for targeted examinations rather than routine surveillance after EPAR.

Spontaneous Isolated Thrombosed True Popliteal Aneurysm in an Eight-Year-Old Child: A Rare Case Report With Literature Review

Spontaneous aneurysms are rare in the pediatric age group. Aneurysms of peripheral arteries are even rarer. The diagnosis should not be missed to prevent distal limb ischemia and life-threatening complications. Hence, timely surgery to save the affected limb is advised. There is an increasing number of reported cases of such aneurysms in the English scientific literature. We present a rare case of pediatric idiopathic popliteal artery aneurysm (PAA), with no known risk factors. This scientific writing is unique in its way of reporting an idiopathic aneurysm with spontaneous onset. However, we have successfully investigated and managed the patient considering the established guidelines on aneurysmal surgery.

Endovascular treatment of complicated aortic aneurysms using a modified flow-diverting strategy: Mid- to long-term outcome from a multicenter cohort study

OBJECTIVES

Frequently reported adverse events following flow-diverting stents' treatment of aortic aneurysms indicate further refinements of this technique are required. This study aims at evaluating the clinical efficacy of an improved flow-diverting strategy.

METHODS

A modified flow-diverting procedure was utilized in selected patients, in which stent-grafts were used to cover the non-branched segment of the aneurysmal lesion while flow-diverting multilayered bare metal stents were applied to cover the reno-visceral segment. The safety and efficacy of this joint procedure were assessed by regular follow-up.

RESULTS

We screened 497 patients and included 67 cases (mean age: 67.07 ± 12.14 years; 53 males) between February 2012 and March 2018. The median number of stent-grafts and bare metal stents used in the procedure were 1 (range: 1 to 3) and 3 (range: 2 to 4), respectively. During a mean follow-up period of 34.54 ± 20.28 months, aneurysm maximum diameter decreased from 64.79 ± 10.31 to 59.32 ± 10.20 mm (p = 0.002), while sac thrombosis ratio increased from 26.01±10.99% to 98.46±4.84% (p<0.001). Aneurysm-related death or conversion to open repair was documented in three patients. The majority side-branches (198/201) remained patent during follow-up. Overall clinical success rate reached 91.04% (61/67).

CONCLUSIONS

The joint procedure is characterized by significant aneurysm thrombosis along with high aneurysm stabilization/shrinkage and side-branches' patency rate. It might represent a potential improvement of the flow-diverting strategy in treating complex aortic lesions, yet large-scale, prospective, and randomized trials are anticipated to draw a robust conclusion.

ADVANCES IN KNOWLEDGE

The joint procedure could potentially exclude complex aortic aneurysms from circulation while maintaining the collateral branches.

Popliteal artery aneurysms treatments: early midterm results of the use of endovascular stent grafts

Background/aim

Popliteal artery aneurysms (PAAs) are abnormal bulgings, which account for 70% of all peripheral artery aneurysms. They are usually asymptomatic. In this study, we present our long-term results of endovascular stent grafts in the treatment of PAA in the light of literature data.

Material and methods

A total of 63 legs of 63 patients with PAA, who were treated with endovascular techniques in our clinic between July 2010 and July 2019, were retrospectively analyzed. All patients underwent color Doppler ultrasound (DUS), magnetic resonance angiography (MRA), or computed tomography angiography (CTA) to identify the diameter and length of PAAs, vessel tortuosity, the presence and degree of thrombus, and diameter in the healthy landing zone and to visualize tibioperoneal vascular structures. A Viabahn stent graft was inserted in all patients.

Results

57 patients (90.5%) were males with a mean age of 76.35 ± 7 years. 24 patients (38.1%) were symptomatic, while 11 patients (17.5%) had a concomitant abdominal aortic aneurysm (AAA). The mean follow-up period was 46.05 ± 25.01 months. The primary patency rate was 79.3%. A graft thrombosis was observed in 13 patients (20.6%) during a mean follow-up period of 8.31 ± 5.91 months. The number of distal arteries was significantly lower in the patients with thrombosis than those without.

Conclusions

Endovascular treatment of PAA using stentgrafts is safe in selected cases. However, it is reasonable to avoid endovascular treatment due to an increased risk for thrombosis in patients with a low number of patent distal arteries or impaired distal flow.

Off-Label Use of a Double-Layer Micromesh Carotid Stent for Hybrid Treatment of Popliteal Artery Aneurism Complicated by Chronic Distal Embolization

We report our initial experience in off-label use of the double-layer micromesh (DLM) Roadsaver® stent for the hybrid treatment of a fusiform popliteal artery aneurism complicated by distal embolization and chronic limb threatening ischemia in a COVID-19-positive young male. A 36-year-old male patient was admitted with chronic limb threatening ischemia of the left lower limb. The duplex ultrasound and computer tomography angiography (CTA) demonstrated a fusiform popliteal artery aneurism with a maximal diameter of 14 mm and distal occlusion of peroneal and both tibial arteries. Urgent hybrid intervention was performed, starting with an open thrombectomy from the distal posterior tibial artery via a retromalleolar access followed by percutaneous deployment of the DLM Roadsaver® stent (Terumo, Tokyo, Japan) for the exclusion of the popliteal artery aneurism. The flow diverting effect was observed immediately with contrast stagnation in the asymmetrical part of the aneurism sac (grade C2 of the O'Kelly-Marotta flow diversion scale). The procedure was uneventful, with the regaining of an adequate foot perfusion and palpable pulse at the posterior tibial artery. On the 2^nd postoperative day, the patient was diagnosed with a symptomatic form of COVID-19 infection and transferred to a dedicated facility. At a one-month follow-up, the patient had no symptoms of limb ischemia and CTA showed complete thrombosis of the aneurism sac, absence of endoleaks, and patency of the treated arterial segment. This case demonstrates the possibility of off-label use of the DLM Roadsaver® stent for hybrid treatment of popliteal artery aneurism complicated by distal embolization and critical limb ischemia.

Outcome of Endovascular Repair of Popliteal Artery Aneurysms using the Supera Stent

PURPOSE

To evaluate the efficacy of endovascular repair of popliteal artery aneurysms (PAAs) with a wire-interwoven nitinol stent.

MATERIALS AND METHODS

This is a prospective, descriptive, and analytical study. From January 2016 to December 2018, 28 consecutive patients (29 lower limbs) were treated for a PAA with the deployment of the Supera stent (Abbott Vascular, Illinois). Twenty-three (79.3%) PAAs were asymptomatic; 6 (20.7%) presented with symptoms. The mean diameter and length of the aneurysm were 26.8 mm (20-40 mm) and 47.1 mm (23-145 mm) respectively. The primary endpoint was the prevention of embolic symptoms. The secondary endpoints were aneurysm exclusion, aneurysm diameter decrease, freedom from reintervention, and preservation of preoperative runoff vessels.

RESULTS

Technical success was 100%, with a median of 2.4 run-off vessels at completion angiography, without any loss of run-off vessels. A double Supera stent was deployed in 10 cases. At completion angiography, a median of 2.4 runoff vessels were present, without any loss of runoff vessels. The mean follow-up time was 24.3 (12-35) months. Primary endpoints were reached in 100% of the cases and vessels run off was preserved in all cases. In 2 PAAs, complete sac thrombosis was witnessed at 6-month follow-up, while at 12-month follow-up, it was seen in 10 of 29 (34.4%) limbs. In all the other cases the diameter of the aneurysm remained stable, with a freedom from sac enlargement of 100%. No fractures or stent thromboses were detected.

CONCLUSIONS

For endovascular repair of PAAs, the use of a thick interwoven-wire stent, that could work like a multilayer flow modulator showed encouraging mid-term results with no cases of stent fracture, occlusion or aneurysm increase.

A systematic review and meta-analysis of the performance of flow-diverting stents in the treatment of peripheral and visceral artery aneurysms

OBJECTIVE

This meta-analysis aims to evaluate the safety and efficacy of flow-diverting stents (FDS) in treating peripheral and visceral artery aneurysms (PAA/VAAs).

BACKGROUND

Though rare, PAA/VAAs can represent a life-threatening condition due to their propensity of rupture. The FDS emerges as a new solution to exclude these aneurysms while maintaining collateral branches, but convincing evidence is lacking on its clinical effectiveness.

METHODS

A systematic literature search was performed to identify studies related to FDS in treating PAA/VAAs. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement was applied to guide the data extraction, quality assessment, and synthesis of outcomes of interest. Random effect models were applied to calculate the event rates of major endpoints. OpenMeta[Analyst] software was used for statistical analysis.

RESULTS

Of 130 records screened, 10 cohort studies (including 220 patients, average age: 66.0 years, 78.4% male) were enrolled in the meta-analysis. Pooled data suggested a technical success rate of 98.5% (95% CI: 97.0-100%). During a mean follow-up period of 14.1 months, 93.6% (95% CI: 88.6-98.5%) side branches remained patent, 89.8% (95% CI: 84.3-95.3%) aneurysms were totally thrombosed, whereas shrinkage/stabilization of the aneurysm was documented in 93.4% (95% CI: 88.4-98.4%) cases. The primary stent patency rate was estimated to be 87.9% (95% CI: 81.0-94.8%). Overall clinical success was achieved in 83.2% (95% CI: 74.4-92.0%) patients.

CONCLUSIONS

The FDS features a potential advantage of preserving side branches while inducing sac thrombosis and aneurysm shrinkage/stabilization. Further prospective, comparative studies in larger patient cohorts are anticipated to draw a robust conclusion.

Results of a three-year follow-up after endovascular therapy with multilayer flow modulator in complex thoracoabdominal aortic aneurysm: A case report

OBJECTIVES

Studies on the short-, medium and long-term effects of flow guiding stents are still limited. In this case report, we present three-year follow-up of the multilayer flow modulator stent in a 55-year-old patient with Crawford Type 2 thoracoabdominal aortic aneurysm.

METHODS

A 55-year-old male patient with Crawford Type 2 thoracoabdominal aortic aneurysm had applied to our medical center. The aneurysm involved coeliac truncus and superior mesenteric artery and extended to the renal artery ostia. Multilayer flow modulator stent was successfully placed, and follow-up CT (Computed tomography) angiographic examination images recorded intermittently (36 months).

RESULTS

After three years, it was observed that the left renal artery was thrombosed and the left kidney went to atrophy. Other major vascular branches were observed to be open. During this time, the aneurysm was completely closed with thrombus, but the diameter of the aneurysm continued to increase.

CONCLUSIONS

Multilayer flow modulator stents are safe in complex aortic aneurysms. The device increases the thrombus load in the aortic aneurysm and maintains the flow of the main vascular branches. But re-interventions, dilatation of the aneurysm sac and visceral branch obstructions are still challenging for multilayer flow modulator stents.

Endovascular versus open repair of asymptomatic popliteal artery aneurysm

BACKGROUND

Popliteal artery aneurysm (PAA) is a focal dilatation and weakening of the popliteal artery. If left untreated, the aneurysm may thrombose, rupture or the clot within the aneurysm may embolise causing severe morbidity. PAA may be treated surgically by performing a bypass from the arterial segment proximal to the aneurysm to the arterial segment below the aneurysm, which excludes the aneurysm from the circulation. It may also be treated by a stent graft that is inserted percutaneously or through a small cut in the groin. The success of the procedure is gauged by the ability of the graft to stay patent over an extended duration. While surgical treatment is usually preferred in an emergency, the evidence on first line treatment in a non-emergency setting is unclear. This is an update of a review first published in 2014.

OBJECTIVES

To assess the effectiveness of an endovascular stent graft versus conventional open surgery for the treatment of asymptomatic popliteal artery aneurysms (PAA) on primary and assisted patency rates, hospital stay, length of the procedure and local complications.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 29 January 2019.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing endovascular stent grafting versus conventional open surgical repair in patients undergoing unilateral or bilateral prophylactic repair of asymptomatic PAAs.

DATA COLLECTION AND ANALYSIS

We collected data on primary and assisted primary patency rates (primary endpoints) as well as operating time, the length of hospital stay, limb salvage and local wound complications (secondary endpoints). We presented results as risk ratio or mean difference with 95% confidence intervals and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

No new studies were identified for this update. A single RCT with a total of 30 PAAs met the inclusion criteria. There was a low risk of selection bias and detection bias. However, the risks of performance bias, attrition bias and reporting bias were unclear from the study. Despite being an RCT, the certainty of the evidence was downgraded to moderate due to the small sample size, resulting in wide confidence intervals (CIs); only 30 PAAs were randomised over a period of five years (15 PAAs each in the groups receiving endovascular stent graft and undergoing conventional open surgery). The primary patency rate at one year was 93.3% in the endovascular group and 100% in the surgery group (RR 0.94, 95% CI 0.78 to 1.12; moderate-certainty evidence). The assisted patency rate at one year was similar in both groups (RR 1.00, 95% CI 0.88 to 1.13; moderate-certainty evidence). There was no clear evidence of a difference between the two groups in the primary or assisted patency rates at four years (13 grafts were patent from 15 PAA treatments in each group; RR 1.00, 95% CI 0.76 to 1.32; moderate-certainty evidence); the effects were imprecise and compatible with the benefit of either endovascular stent graft or surgery or no difference. Mean hospital stay was shorter in the endovascular group (4.3 days for the endovascular group versus 7.7 days for the surgical group; mean difference (MD) -3.40 days, 95% CI -4.42 to -2.38; P < 0.001; moderate-certainty evidence). Mean operating time was also reduced in the endovascular group (75.4 minutes in the endovascular group versus 195.3 minutes in the surgical group; MD -119.90 minutes, 95% CI -137.71 to -102.09; P < 0.001; moderate-certainty evidence). Limb salvage was 100% in both groups. Data on local wound complications were not published in the trial report.

AUTHORS' CONCLUSIONS

Evidence to determine the effectiveness of endovascular stent graft versus conventional open surgery for the treatment of asymptomatic PAAs is limited to data from one small study. At one year there is moderate-certainty evidence that primary patency may be improved in the surgery group but assisted primary patency rates were similar between groups. At four years there was no clear benefit from either endovascular stent graft or surgery to primary or assisted primary patency (moderate-certainty evidence). As both operating time and hospital stay were reduced in the endovascular group (moderate-certainty evidence), it may represent a viable alternative to open repair of PAA. A large multicenter RCT may provide more information in the future. However, difficulties in recruiting enough patients are likely, unless it is an international collaboration including a number of high volume vascular centres.

Predictor of false lumen thrombosis after thoracic endovascular aortic repair for type B dissection

OBJECTIVE

Thoracic endovascular aortic repair of type B aortic dissection initiates thrombosis in the false lumen, which eventually results in aortic remodeling. We aimed to determine whether the false lumen thrombosis rate (FLTR) after thoracic endovascular aortic repair can be accurately predicted by an index that expresses the degree of aortic arch angulation.

METHODS

The geometry of 48 patients with acute type B aortic dissection (mean age, 48 years) after thoracic endovascular aortic repair was reconstructed from postoperative computed tomography images. We introduced a novel angle-the degree of question mark (φ)-to indicate the aortic morphology. Moreover, how aortic angulation influenced the FLTR was investigated based on hemodynamic parameters. Finally, a predicted mathematical model relating FLTR to aortic angulation was proposed, and 10 patients were chosen to validate the model.

RESULTS

The degree of question mark shape was shown to negatively correlate with FLTR (n = 38; P < .001; R = -0.661), and the linear relationship model was created as follows: FLTR (%) = -1.955 × φ + 168.24 (R² = 0.437; P < .001). In addition, the net flow rate to the false lumen significantly increased with the increase of the degree of the question mark shape of the aorta. Furthermore, the difference and concordance of the proposed prediction model were perfectly validated in the remaining 10 patients using paired-sample t test and the concordance correlation coefficient.

CONCLUSIONS

The size of the question mark shape may be a good predictor for FLTR of acute type B aortic dissection following thoracic endovascular aortic repair. The higher the degrees of the question mark, the less likely it was to form a complete thrombus.