Stenting of stenotic right ventricular outflow tract is a palliative measure for severely impaired small babies with Tetralogy of Fallot or similar pathologies. Little is known about the histopathological fate of the stents in the right ventricular outflow tract.

Eight samples of surgically removed right ventricular outflow tract stents were histologically analysed according to a predefined protocol.

The most frequent diagnosis was Tetralogy of Fallot in four patients, pulmonary atresia with ventricular septal defect in two patients, double outlet right ventricle with pulmonary obstruction in one patient, and muscular obstruction of the right ventricular outflow tract in one patient with a syndromic disease with hypertrophic cardiomyopathy. Stents mean implantation duration was 444 days ranging from 105 to 1117 days (median 305.5 days). Histology revealed a variable degree of pseudointima formation consisting of fibromuscular cells surrounded by extracellular matrix. Four of the specimen contained adjacent myocardial tissue fragments, which showed regressive changes. Neither myocardium nor pseudointima tissue or tissue parts locally related to stent struts were infiltrated by inflammatory cells.

Histological analysis after explantation of early-in-life implanted right ventricular outflow tract stents revealed predominantly pronounced neo-intimal proliferation with a visible endothelial layer, no signs of inflammation, and no prolapse of muscular tissue through the stent struts. Thus, implantation of stents in early life seems to interfere little with the hosts’ immune system and might help to open up the right ventricular outflow tract by mechanical forces and regressive changes in adjacent muscular tissue.

Frontal sinus stents have been introduced to reduce frontal sinus re-stenosis after surgery and to improve outcomes.

This study was a retrospective analysis of 19 patients who had endoscopic sinus surgery with approach to the frontal sinus and insertion of a soft sinus stent.

The frontal recess was patent in 78.9 per cent and stenosed in 21.1 per cent of patients; no completely closed recesses were observed. Mean follow up was 20.7 months, and time period of stenting was 9.8 months on average; complications were observed in 47.4 per cent of the patients, with post-operative sinonasal infection being the most common.

In the authors’ experience, indications for frontal sinus stenting include recalcitrant chronic rhinosinusitis after multiple functional endoscopic sinus surgeries (especially in chronic rhinosinusitis with nasal polyps), patients with history of important craniofacial surgery or trauma, and recurrent mucoceles. The stent was overall well tolerated as only minor complications were observed. Close clinical follow up is mandatory.

The COVID-19 pandemic has resulted in huge disruption to healthcare delivery worldwide. There is a need to balance the urgent needs of the neurovascular patient population with the desire to preserve critical inpatient hospital capacity. It is incumbent on neurointerventionalists to advocate for their patients to minimise future disability. Patients still require semiurgent carotid revascularisation after ischaemic embolic events. We present a review of a novel protocol for expediting patient flow through the carotid stenting process, in accordance with government directives to minimise nonessential inpatient admissions, ensure its efficacy, and evaluate its safety. We also evaluate the literature regarding complications with attention to the timing of these related to the procedure.

A retrospective review of 45 consecutive carotid stenting cases performed at London Health Sciences Centre between March 2020 and March 2021 for symptomatic extracranial internal carotid artery stenosis utilising a default same-day discharge policy was performed. Complications were plotted as a function of time.

Twenty-four patients underwent carotid artery stenting with same-day discharge and 21 patients underwent stenting with an overnight inpatient stay. A single stent occlusion occurred 27 h post stenting.

Simple modification of protocol for symptomatic carotid artery stenting during the COVID-19 outbreak with radial access as first approach appears to provide safe, efficacious care.

Patent ductus arteriosus stenting in duct-dependent pulmonary circulation is a challenging procedure. Percutaneous carotid artery access for ductal stenting has proven to be feasible; however, comparison with femoral artery access in terms of procedure details and complications either immediate or late is scarce. Therefore, we evaluated carotid artery access in comparison with femoral artery for stenting of patent ductus arteriosus.

Forty neonates were reviewed, 20 were stented via carotid artery access, and 20 via the traditional femoral artery access. Comparison variables were neonatal demographics at the procedure, angiographic ductal anatomy, procedure details, and immediate complications. Follow-up Doppler ultrasound on access site was performed to document late complications.

Median age of included cases was 10.5 (3–28) days with complex ductal anatomy more frequently accessed via carotid artery than femoral. Immediate access-related complications were significantly higher with femoral than carotid artery access; 9 (45%) versus 3 (15%) respectively, p = 0.038. With carotid access, we had only one case with small pseudoaneurysm and acute hemiparesis 3 days after the procedure. Delayed local complications were more common with femoral access (15%) than carotid access (5%), mild stenosis in one case, and severe in another with femoral access; while with transcarotid arterial access, only one case had mild narrowing.

Percutaneous carotid artery access in neonates is a more convenient approach for patent ductus arteriosus stenting especially with complex ductal anatomy. Moreover, local complications are limited and vascular patency is better preserved, in comparison with trans-femoral arterial access. However, the potential for neurological adverse events should not be overlooked.

Recurrent aortic arch obstruction following the Norwood procedure is recognised as an important complication. Balloon arch angioplasty is associated with a high recoarctation rate.

We sought to evaluate the prevalence and outcome of stent implantation for recoarctation in children following Norwood or Damus–Kaye–Stansel procedure over the past decade at a single national cardiology centre.

Of 114 children who underwent Norwood procedure or Damus–Kaye–Stansel procedure between January 2003 and June 2013, 80 patients survived. Of these 15 children underwent stent implantation for recoarctation. Six of these patients had previous balloon angioplasty. The median age at stent implantation was 4.4 months (range 2–82 months). The median peak aortic arch gradient at catheterisation decreased from 26mmHg (range 10–70mmHg) to 2mmHg (range 0–20mmHg). The median luminal diameter increased from 4.7 mm (range 3.2–7.9 mm) to 8.6 mm (range 6.2–10.9 mm). The median coarctation index increased by 0.49 (range = 0.24–0.64). A Valeo stent was employed in 11 children, a Palmaz Genesis stent in 2 patients, a MultiLink stent in 1 child, and a Jomed covered stent in 1 child. Two factors were associated with the need for stent placement: previous arch angioplasty (p valve < 0.001, χ-square 11.5) and borderline left ventricle (p = 0.04, χ-square = 4.1). Stent migration occurred in one child. There were two deaths related to poor right ventricular systolic function and severe tricuspid regurgitation. Six patients underwent redilation of the stent with no complications.

The prevalence of recurrent aortic arch obstruction following Norwood/Damus–Kaye–Stansel procedure was 18%. Stent implantation is safe and reliably eliminates the aortic obstruction. Redilation can be successfully achieved to accommodate somatic growth or development of stent recoarctation.

Transcatheter stent implantation has been employed to treat re-coarctation of the aorta in adolescents and young adults. The aim of this work is to use computational fluid dynamics to characterise haemodynamics associated with re-coarctation involving an aneurysmal ductal ampulla and aortic isthmus narrowing, which created minimal pressure drop, and to incorporate computational fluid dynamics’s findings into decision-making concerning catheter-directed treatment.

Computational fluid dynamics permits numerically solving the Navier–Stokes equations governing pulsatile flow in the aorta, based on patient-specific data. We determined flow-velocity fields, wall shear stresses, oscillatory shear indices, and particle stream traces, which cannot be ascertained from catheterisation data or magnetic resonance imaging.

Computational fluid dynamics showed that, as flow entered the isthmus, it separated from the aortic wall, and created vortices leading to re-circulating low-velocity flow that induced low and multidirectional wall shear stress, which could sustain platelet-mediated thrombus formation in the ampulla. In contrast, as flow exited the isthmus, it created a jet leading to high-velocity flow that induced high and unidirectional wall shear stress, which could eventually undermine the wall of the descending aorta.

We used computational fluid dynamics to study re-coarctation involving an aneurysmal ductal ampulla and aortic isthmus narrowing. Despite minimal pressure drop, computational fluid dynamics identified flow patterns that would place the patient at risk for: thromboembolic events, rupture of the ampulla, and impaired descending aortic wall integrity. Thus, catheter-directed stenting was undertaken and proved successful. Computational fluid dynamics yielded important information, not only about the case presented, but about the complementary role it can serve in the management of patients with complex aortic arch obstruction.

To assess the feasibility, safety, and efficiency of ductal stenting in pulmonary atresia with intact ventricular septum or critical pulmonary stenosis after balloon pulmonary valvuloplasty.

Ductal stenting in pulmonary atresia with intact ventricular septum is a re-emerging and promising technique. There is little data available on its outcomes after establishing prograde pulmonary blood flow.

We retrospectively reviewed all neonates with pulmonary atresia with intact ventricular septum or critical pulmonary stenosis who underwent ductal stenting after balloon valvuloplasty. Ductal stenting was performed either in the same setting (group A) or a few days later after balloon valvuloplasty (group B). We compared the two groups.

Eighteen coronary stents were transvenously delivered and successfully deployed in 18 newborns. There was no procedure-related mortality. The median hospital stay post-intervention was 6 days with a mean discharge oxygen saturation of 94%. Group A had a shorter overall hospital stay with a shorter overall time of irradiation but with a longer overall procedural time. On a follow-up of 18 months, no re-intervention for stent failure or overflow was undertaken. The median stent patency based on echocardiography was 12 months.

Stenting the arterial duct in pulmonary atresia with intact ventricular septum or critical pulmonary stenosis is a feasible, safe, and efficient technique. It avoids surgery or long hospital stay with prostaglandin infusion. The minimal 6 months stent longevity provides a period of time long enough to decide whether the right ventricular diastolic function is normalised or Glenn surgery is still needed.

One indication for intervention in coarctation of the aorta is a peak-to-peak gradient >20 mmHg. Gradients may be masked in patients under general anaesthesia and may be higher during exercise. Isoproterenol was given during cardiac catheterisation to simulate a more active physiologic state.

We aimed to describe the haemodynamic effects of isoproterenol in patients with coarctation and the impact of intervention on the elicited gradients.

A retrospective study was performed on two-ventricle patients who underwent cardiac catheterisation for coarctation with isoproterenol testing.

25 patients received isoproterenol before and after intervention. With isoproterenol, the mean diastolic (p=0.0015) and mean arterial (p=0.0065) blood pressures proximal to the coarctation decreased significantly. The mean systolic, diastolic, and mean arterial blood pressures distal to the coarctation decreased significantly (p<0.0001). In patients with a baseline gradient ⩽20 mmHg (n=17) at catheterisation, the median gradient increased from 10 (0–20) to 30 (15–50) mmHg (p<0.0001) with isoproterenol. Of these, 15 patients developed a gradient >20 mmHg. Post intervention, the median gradient decreased to 2 (0–29) mmHg, versus baseline, p=0.005, and with isoproterenol it decreased to 8 (0–27) mmHg, versus pre-intervention isoproterenol, p<0.0001. There were significant improvements in the gradients by Doppler (<0.0001) and by blood pressure cuff (p=0.0313). The gradients on isoproterenol best correlated with gradients by blood pressure cuff in the awake state (R2=0.76, p<0.0001).

Isoproterenol can be a useful tool to assess the significance of a coarctation and the effectiveness of an intervention. Percutaneous interventions can effectively reduce the gradients elicited by isoproterenol.