The CP stent--short, long, covered--for the treatment of aortic coarctation, stenosis of pulmonary arteries and caval veins, and Fontan anastomosis in children and adults: an evaluation of 60 stents in 53 patients

Repair of iatrogenic left pulmonary artery to left atrial appendage fistula using a covered CP stent: a case report

We report a case of iatrogenic left pulmonary artery-left atrial appendage fistula following percutaneous transluminal angioplasty for residual pulmonary artery stenosis in an 11-year-old boy. This rare complication could have been predicted by understanding the anatomical relationship of these structures. In this study, simulation using three-dimensional printing greatly contributed to successful stent placement.

Medium-Term Outcomes of Stent Therapy for Aortic Coarctation in Children Under 30 kg with New Generation Low-Profile Stents: A Follow-Up Study of a Single Centre Experience

We previously reported short-term outcomes for stenting of aortic coarctation (CoA) (native or re-coarctation) with newer generation low-profile stents (Valeo, Formula, and Begraft stents) in children under 30 kg. We present here the medium-term outcomes of this procedure. Retrospective review of patients weighing under 30 kg who had percutaneous stent treatments for coarctation between 2012 and 2021 was performed. Clinical and procedural data were collected; 19 patients were included. The median age at the time of procedure was 5.1 [4.1-6.4] years and median weight 21.0 [17.3-22.3] kg. One patient had a history of re-coarctation. Thirteen (68%) patients were on anti-hypertensives pre-procedure. Different types of stents were used (14 Valeo™, 4 Formula® 535, 1 BeGraft), which can all be dilated to 18 mm or larger. One patient required a 9 F sheath, all others required a 7 F sheath. The narrowest diameter in the aorta increased from a median of 3.5 [3.0-4.5] to 9.4 [8.9-9.8] mm, p < 0.001; there was a reduction in the median pressure gradient across the coarctation from 35.0 [30.0-43.0] to 5.0 [0-10.0] mmHg, p < 0.001. There were no intra-procedural complications. Follow-up was for a median of 56.0 [13.0-65.0] months. Five (26%) of patients underwent re-intervention after a median time frame of 40.0 [39.5-52.0] months; four had balloon dilation, one had repeat stent implantation. Five (26%) patients were on anti-hypertensive agent(s) post-intervention. Our single centre experience demonstrates that percutaneous stenting for coarctation of aorta in children under 30 kg, with low-profile stents, had no significant complications during the median follow-up time of 56 months. This study demonstrated that the procedure is safe and effective for short and medium-term therapy in this group of patients with a 26% re-intervention rate. A quarter of patients remained on anti-hypertensive medication post stenting, emphasizing the importance of long-term follow-up.

A new FDA approved stent for congenital heart disease: First-in-man experiences with G-ARMORTM

We present the first clinical experience with a new hybrid cell structure covered stent, designed for congenital heart disease applications. It represents a significant redesign of the Cheatham Platinum (CP) Stent (Numed Inc.), maintaining the traditional benefits of the covered CP whilst significantly decreasing shortening and allowing controlled flaring at the ends through its combination of larger and standard sized cells. We first implanted the stent in 2 patients with superior sinus venosus defects with anomalous drainage of the right upper and middle lobe pulmonary veins. The first was a 40 year male and the second a 36 year old female. The third case was a 60 year old patient with near atresia of the aorta, with pre and poststenotic aortic dilation. The clinical result in all cases was excellent with no obstruction to pulmonary venous return and no visible L-R shunt on the transthoracic echo on 24 h and 2 week follow-up for the patient with sinus venosus defects and uniform complete revascularization of the aorta without any vascular complications in the patient with coarctation. These are the first uses of this stent in human subjects. The design is specifically aimed toward procedures where stent shortening is undesirable. Hence, coarctation of the aorta as well as stent implantation in preparation for percutaneous pulmonary valve placement are obvious use areas, as well as the growing body of evidence supporting percutaneous treatment of sinus venosus defects.

Transcatheter implantation of covered stents serving as extravascular conduits-Proof of a CT-based approach in three cases

BACKGROUND

Covered stents perform similar to surgically implanted conduits, although the stents work inside of vessels. We present a computed tomography (CT)-based workflow for the implantation of covered stents as extravascular conduits.

METHODS

We selected three different use cases: 1. Connecting a left-sided partially anomalous drainage of a pulmonary vein to the left atrium. 2. Bypassing an outgrown Dacron conduit in aortic recoarctation. 3. Re-directing hepatic venous blood to the left lung in a Fontan patient with heterotaxy, connecting the innominate vein to the right pulmonary artery like a right-sided cavopulmonary connection. By postprocessing and analyzing CT scans for planning and by the use of long needles under biplane fluoroscopy for the realization of the procedure, we projected and performed the exit of a long needle out of a vessel, the re-entering of a target vessel, and the bridging of the extravascular distance by implantation of covered stents.

RESULTS

In all three cases, the covered stents were placed successfully, connecting vessels of 15-50 mm distance from each other with very good hemodynamic results. In one case, two stents were placed consecutively, overlapping each other to accomplish an exact fitting at the connection sites to the native vessels.

Covered Stents in the Management of Aortic Coarctation and Right Ventricular Outflow Tract Obstruction

PURPOSE OF REVIEW

To review the use of covered stents in the treatment of coarctation of the aorta (CoA) and right ventricle to pulmonary artery (RV-PA) conduit obstruction.

RECENT FINDINGS

The only commercially available covered stent approved for treatment of CoA and dysfunctional RV-PA conduits is the covered Cheatham-Platinum stent (CCPS). Early outcomes have demonstrated its safety and have suggested its efficacy in treating or preventing aortic wall injury (AWI) or conduit disruption. A recent study of CCPS use for CoA reported a progressive risk of stent fracture over time and a risk of AWI despite the purported protection that the CCPS provides. The use of other covered stents has been reported, but large, systematic studies are lacking. CCPS use may reduce but does not eliminate the risk of conduit disruption or AWI. Structural limitations of the CCPS may predispose it to stent fracture. Access to a broad range of covered stents continues to be an unmet need in the field of congenital interventional cardiology.

Mechanical properties of low-diameter balloon expandable covered stents

OBJECTIVES

To determine over-dilation potential of commercially available covered stents.

BACKGROUND

Covered stents including the Atrium iCast, Gore VBX, and Lifestream stents (LS) can treat ruptures, dissections, and aneurysms in small vessels. Especially in growing patients, stents often require serial dilations beyond their implant or nominal diameters. Tolerance of serial dilations is clinically important information for interventionalists.

METHODS

Serial dilations of 5-12 mm iCast, VBX, and LS covered stents were performed in 1-2 mm increments (up to 20 mm). With each dilation, foreshortening and recoil were measured, and stent strut and covering integrity were assessed. High-pressure balloons were used to expand the stents until they fractured or could not be further expanded.

RESULTS

The 5-8 mm LS tolerated dilation to 14.5-16 mm. The 10-12 mm LS stents tolerated dilation to 18 mm and fractured on the 20 mm balloon. LS stents foreshortened 35%-45% on average after 8 mm of over-dilation and had 5%-10% recoil on <6 mm over-dilation. All iCast stents tolerated dilation to 12-13 mm and required fracture for dilation to >14 mm. ICast stents foreshortened 19%-29% at maximum dilation, with 3-6% recoil on <2 mm over-dilation, and < 3% thereafter. VBX stents over-dilated to 2.9-4.7 mm above nominal, foreshortening 40%-50% after 4-6 mm of over-dilation before collapsing into a ring. VBX stent recoil was <2.5% on all dilations.

CONCLUSIONS

LS stents had the greatest over-dilation potential. VBX stents had the least recoil but tended to foreshorten significantly 3-4 mm above nominal. Regardless of nominal size, all iCast stents (including the 5 mm) tolerated dilation to a maximum of 12-13 mm.

Endovascular stent implantation for aortic coarctation: parameters affecting clinical outcomes

OBJECTIVE

To evaluate safety and efficacy of endovascular stenting for aortic coarctation (AC) and to explore the effect of clinical parameters and stent characteristics on outcomes.

MATERIAL AND METHODS

Clinical data of all patients with AC who had attempted transcatheter stenting between 2004 and 2019 were retrospectively reviewed. Eligible patients had native or recurrent AC with systemic arterial hypertension and resting arm-leg pressure gradient > 20 mmHg. Exclusions included distance between takeoff of cervical arteries and stenotic aortic lesion < 10 mm, contraindication to antithrombotic therapy, bodyweight < 25 kg, and secondary hypertension.

RESULTS

A total of 20 patients (75.0% with native lesions) were included with a mean age of 18.4 years and a mean bodyweight of 59.2 kg. Procedure was successful in 90.0% of cases with an immediate drop in the invasive pressure gradient across lesions. On a median follow-up of 12 months (range, 8 to 144.9 months), coarctation reoccurred in five patients, but four of them required intervention after a median of 104.4 months with successful outcomes. Cheatham Platinum stents were significantly associated with lower rates of recoarctations and reinterventions. At the latest follow-up, three out of six patients with persistent hypertension had no recoarctation. Analysis showed that the need for antihypertensive therapy was not influenced by clinical parameters, aortic arch geometry, or stent characteristics.

CONCLUSION

Treating AC with stent implantation is a safe and successful procedure. Using Cheatham Platinum stents appears to be associated with better outcomes. The persistence of arterial hypertension despite successful stenting remains a complex and challenging phenomenon.

Mid-term outcomes with adult endovascular treatment of coarctation of the aorta

BACKGROUND

This study examines the contemporary medium- and long-term outcomes of endovascular repair of aortic coarctation in the adult.

METHODS

We reviewed the clinical and imaging data of 56 consecutive adult patients with aortic coarctation who underwent endovascular repair at the Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada, from 2003 to 2018.

RESULTS

There were 20 (35.7%) female and 36 (64.3%) male patients (including 9 re-intervention cases) with a mean age of 33.6 ± 13.6 years. Thirty-seven (66.1%) were treated with balloon-expandable covered stent and 12 (21.4%) were treated with balloon-expandable bare-metal stent. Pressure gradients decreased from baseline level of 27.99 ± 12.75 (8-70) mm Hg to 5.33 ± 4.42 (0-17.5) mm Hg following the procedure. There were 2 (3.6%) procedure related complications (aortic dissection [n = 1] and stent malposition [n = 1]). During a median (Q1 - Q3) follow up of 5.36 (2.28-7.58) years, 2 deaths (4.2%) and 9 (19%) re-interventions occurred, and the overall survival was 95.8%.

CONCLUSION

Percutaneous coarctoplasty, with either covered or bare metal stents, is a safe and durable option for aortic coarctation repair with excellent long-term survival.

Closure of an unusual morphology patent ductus arteriosus with a covered stent in a dog

Patent ductus arteriosus (PDA) with unusual morphology was diagnosed in a 3-year-old German shepherd presented for exercise intolerance. Two interventional PDA closure procedures with various Amplatzer devices and one surgical ligation were attempted to close the PDA. However, PDA closure failed with both methods due to the unusual morphology and the severe enlarged ductus ampulla. Therefore, the patient underwent an aortic covered stent placement, and successful closure of the PDA was achieved. Eight months after the procedure, the dog was free of clinical signs and no residual flow was identified through the PDA on transthoracic echocardiography. Moreover, computed tomography angiography demonstrated correct stent positioning, with no evidence of thrombus formation, damage to the stent, nor any aortic wall abnormalities. Aortic covered stent placement is a viable option in dogs with unusual PDA morphology.

Clinical trial of the CP stent for pulmonary artery stenosis: the first investigator-initiated clinical trial for pediatric interventional cardiology in Japan

Stenting is an important treatment option for pulmonary artery stenosis (PS) associated with congenital heart disease (CHD). However, no stent has been approved for this indication in Japan, despite negotiation between academia and the regulatory bodies for longer than 20 years. To evaluate efficacy and safety of the CP stent, we performed the first investigator-initiated clinical trial for pediatric interventional cardiology in Japan. This trial was designed as a single-arm, prospective, clinical trial. Patients who had postoperative PS associated with CHD were included. Stenting was attempted in 24 cases and succeeded in 22 cases. The median age of the patients was 11 years (3-36 years) and weight was 38 kg (12-69 kg), while follow-up for 12 months was completed. In all 22 cases, stenting was successful, with a 50% increase in the minimum lumen diameter (MLD) in 86.4% of patients (90% confidence interval, 68.4-96.2%). The mean percent change in MLD was 119.3 ± 52.5%. In two-ventricle repair, the mean percent change in systolic right ventricular/aortic pressure was - 8.5 ± 16.1%, while that of pressure gradient was - 55.9 ± 41.7%. In single-ventricle repair, the percent change in the mean pressure gradient was - 100.0 ± 0%, while that of SaO2 was 1.4 ± 1.7%. No serious adverse events or significant restenosis was reported. The CP stent is highly effective and safe for PS associated with CHD. This study has significant importance in not only scientific but also social considerations.

Early and late outcome of covered and non-covered stents in the treatment of coarctation of aorta- A single centre experience

Objective

Stenting of coarctation of aorta with covered or uncovered stents is the accepted modality of treatment in older children and adults. The indications which mandate the use of covered stents are still unclear. We attempted to study the early and late outcomes after stenting of native and recurrent coarctation of aorta with uncovered and covered stents.

Method

This is a retrospective study of patients who underwent stenting for coarctation of aorta with covered or non-covered stents at our institute. Early and late outcome for both the groups were studied.

Results

Twenty patients underwent implantation of covered stent and twenty five patients had uncovered stent implantation. Patients in the covered stent group were older and had greater basal pressure gradient. More patients in the covered stent group had residual gradient >10 mm Hg after the procedure. There was no mortality or aortic wall injury in either group. Four patients in the covered stent group underwent planned re-intervention and two had unplanned re-intervention. None of the patients in the uncovered stent group had re-intervention. Higher incidence of late lumen loss was noted in the covered stent group.

Conclusion

Uncovered stents can be safely implanted with minimal risk of aortic wall injury in patients with low risk anatomic features. Covered stent implantation is associated with higher incidence of planned and unplanned re-intervention.

Infectious stentitis after treatment of coarctation of the aorta: a case report

Background

Aortitis is a rare condition that can be caused by inflammatory or infectious aetiologies. The clinical presentation of aortitis includes a heterogeneous range of symptoms and clinical signs.

Case summary

We present a 53-year-old man whose medical history included presence of a ventricular septal defect, a bicuspid aortic valve, and coarctation of the aorta. The coarctation was treated with percutaneous stent implantation. One and a half years later, he presented to our hospital with complaints of fatigue, night sweats, and shivers. Physical examination revealed a fever, tachycardia, and hypertension. Imaging studies showed no signs of endocarditis. Positron emission tomography-computed tomography (PET-CT) showed an increase in ¹⁸F-fluorodeoxyglucose uptake at the distal end of the stent in the descending aorta. Blood cultures revealed a Streptococcus gordonii and antibiotic treatment was adjusted accordingly. The patients' functional status improved quickly, the fever resolved, and the laboratory markers of inflammation returned to normal.

Discussion

Aortitis is extremely rare after stent implantation. Risk factors for aortitis include congenital vascular malformation and stent implantation. Computed tomography is currently the imaging study of choice for aortitis, while PET-CT seems ideal for identification of stent infection. Mortality associated with infectious aortitis ranges from 21% to 44%, with generally higher mortality if managed with antibiotics alone. The differential diagnosis of stent infection should be taken into account in patients presenting with fever and chills after previous stent procedures.

Coarctation: A Review

Coarctation of the aorta occurs in 0.04% of the population, and accounts for approximately 10% of lesions in adults with congenital heart disease. It can occur as an isolated lesion or as a part of a complex defect, and is most commonly associated with bicuspid aortic valve, ventricular septal defect, and mitral valve abnormalities. Since the first surgical repair in 1944, the available treatment options have expanded greatly. Perhaps one of the most important advances in the management of coarctation of the aorta has been the development of transcatheter therapy for both native and especially recurrent coarctation of the aorta. Late complications, even after apparently successful treatment, are not uncommon. For this reason, lifelong follow-up is vital.

Covered CP Stent for Treatment of Right Ventricular Conduit Injury During Melody Transcatheter Pulmonary Valve Replacement

BACKGROUND

High-pressure balloon and stent angioplasty are frequently necessary to prepare the dysfunctional right ventricular outflow tract conduit before transcatheter pulmonary valve replacement (TPVR). Conduit injury can result, which may be catastrophic to the patient or prevent successful TPVR.

METHODS AND RESULTS

The PARCS trial (Pulmonary Artery Repair With Covered Stent) was a pivotal, prospective multicenter trial to evaluate the safety and efficacy of the NuMED Covered CP Stent (CCPS) for treatment of conduit injury occurring during TPVR. The study also evaluated immediate and short-term TPVR function in patients receiving covered stents. A total of 616 patients were consented; 120 (19.5%) had a wall injury identified and were treated with CCPS. Severe conduit injuries were uncommon (5%), but predictors for severe injury were not identified. Stenotic homografts had the highest incidence of injury (29%), compared with other conduit substrates. Among patients receiving CCPS implant, 96% required no further therapy for conduit injury, and 94% underwent TPVR at that procedure. Only 2 patients (1.6%) required urgent surgery for conduit injury, despite CCPS implant. There were few CCPS-related complications. TPVR function was similar between CCPS and non-CCPS groups at follow-up.

CONCLUSIONS

Conduit injury during TPVR is common, although severe injury is rare. The CCPS was a safe and effective treatment for right ventricular outflow tract conduit injury during preparation for TPVR, allowing nearly all patients to complete the procedure without identifiable impact on valve performance.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01824160.

Use of a Covered CP Stent to Exclude an Aortic-Brachiocephalic Conduit Pseudoaneurysm

A 63-year-old woman was incidentally found to have a thoracic aortic aneurysm. We performed hybrid repair involving aortic arch debranching and endovascular stent-graft placement. Four months later, an asymptomatic pseudoaneurysm had formed at the aortic conduit-brachiocephalic artery anastomosis. To exclude the pseudoaneurysm, we deployed a Covered CP Stent across the anastomosis through a surgically created right axillary artery conduit. We discuss the patient's case and our choice of treatment.

Single-stage endovascular management of complicated thoracic aorta coarctation concurrent with aortic arch aneurysm using a novel fenestration device

To present a case with aorta coarctation complicated by aortic arch aneurysm which is clinical rare and entails a high risk of rupture. Here we reported a 46-year-old female patient diagnosed with aortic arch aneurysm combined with coarctation. The computed tomography angiography shows that an irregular aneurysm was located at the aortic arch site with its maximal diameter 86.55 mm and the right end of aneurysm was located 10 mm away from the ostium of left common carotid artery (LCCA). The aneurysm body invaded the left subclavian artery, and at the distal end of aneurysm a coarctation had been observed with a minimum diameter reaching 2.7 mm. We performed percutaneous balloon angioplasty, thoracic endovascular aortic repair to exclude the aneurysm, and simultaneously used a novel in situ fenestration device (Quick-Fenestrater) to revascularize the covered LCCA. This is first case of using a novel fenestration device single-stage endovascular treatment of complicated thoracic aorta coarctation concurrent with aortic arch aneurysm. Combined endovascular techniques can elevate the success rate of reconstruct complicated aorta aneurysm concurrent with coarctation and reduce complications. Under the guidance of Quick-Fenestrater, in situ fenestration could be performed with safety and a high success frequency.

Aortic rupture during stenting for recurrent aortic coarctation in an adult: live-saving, emergency, NuDEL all-in-one covered stent implantation

We report a case of successful, life-saving implantation of a covered Cheatham Platinum stent, an all-in-one NuDEL catheter system, in an adult with aortic rupture after bare-metal stenting for re-coarctation of the aorta.

Use of the AndraStent XL and XXL for the treatment of coarctation of the aorta in children and adults: immediate and midterm results

AIMS

The aim of this study is to present our experience with a new type of extra-large stent, namely the AndraStent XL/XXL.

METHODS AND RESULTS

AndraStents were implanted in 46 patients, 38 with native coarctation of the aorta (CoA) and eight with recurrent coarctation of the aorta following previous surgery (ReCoA). All patients had arterial hypertension in the upper limbs, absent or weak femoral pulses, and continuous flow in the abdominal aorta on Doppler examination. The median age of patients was 25 years (range from nine to 65). The stents (cobalt-chromium with semi-open cell design) were manually mounted on balloon catheters and delivered through 10 to 14 Fr Mullins sheaths using a conventional femoral approach. All procedures were successful (no stent migration, proper expansion, no aorta dissection/rupture, major bleeding or major vessel injury). The systolic gradient across the aorta decreased from 40.6 mmHg before the procedure to 11.6 mmHg after the procedure (p<0.001). The mean fluoroscopy time was 5.7 minutes. Imaging examinations were scheduled and performed between six and 12 months after the initial procedure in 40 patients (angiography or angio CT or both). Procedural outcome remained favourable during a mean 2.4 years of follow-up. Neither stent fracture nor dislocation was observed in any patient at follow-up. In two patients, small aneurysm formation was observed six and eight months after the procedure -they were treated successfully with subsequent covered stent implantation. Re-dilatation of the implanted stent was performed between four and 26 months in 14 patients.

CONCLUSIONS

Implantation of new large cobalt-chromium stents is a good therapeutic option for the treatment of native and recurrent CoA.

A systematic review and meta-analysis of outcomes of transcatheter stent implantation for the primary treatment of native coarctation

BACKGROUND/OBJECTIVES

The treatment of native coarctation of aorta (CoA) has evolved since surgery performed in 1944, followed by transcatheter balloon angioplasty and recently, widely adopted stent implantation. Despite good results demonstrated with stent implantation, a systematic review and meta-analysis (SRMA) looking at the efficacy and safety of the intervention, particularly in younger population is yet to be done. We aimed to obtain pooled estimates of the success and complication rates after transcatheter stent implantation in the treatment of native CoA based on SRMA.

METHODS

We searched literature published until 31 Dec. 2015, reporting outcomes of transcatheter stent implantation in the treatment of native CoA. The pooled estimates were obtained using the random effect model.

RESULTS

Seventeen reports comprising 561 patients were included. Fourteen studies reported 100% success rate, the lowest was 77%, the largest study reported 81% using a definition of systolic pressure difference of less than 15mmHg. The pooled estimate of overall success rate was 98% (95% CI: 94.5-100.0; I²=65%, heterogeneity test p<0.001). Six out of 17 studies reported zero complication. Two studies, however, reported complications in almost half of the cohort. The pooled estimate of rate of complications was 10% (95% CI: 5.1-15.5; I²=72%, heterogeneity test p<0.001). Three studies comprising only children, 62, with mean age of 11.1 (4-19) years reported high mean success rate at 98% with only 1 failure.

CONCLUSIONS

There is a high success rate with a small complication rate with stent implantations for native CoA even as the treatment is brought to younger age group.

"Intraoperative hybrid stenting of recurrent coarctation and arch hypoplasia with large stents in patients with univentricular hearts"

BACKGROUND

Obstruction of the reconstructed aortic arch, tubular hypoplasia and recurrent coarctation (RC) is an important risk factor in univentricular physiology. For the past two years we have adopted the concept of intraoperative hybrid stenting of RC and arch hypoplasia with large stents in patients with univentricular hearts as standard care procedure.

METHOD/RESULT

Retrospective analysis of the anatomy and procedural outcome of 14 patients was scheduled for intraoperative stenting of the aortic arch (12 during surgery for BCPS, 2 during Fontan completion). The median age was 5.3 months, weight 5.5 kg, height 62 cm. Five patients had tubular hypoplasia and 9 patients had distal stenosis of the aortic arch. Nine patients had a previous balloon dilatation. The mean diameter of the distal arch was 11.0mm, at the coarctation 5.1mm, at the level of the diaphragm 8.2mm (CoA-index 0.62). Intraoperative stenting was performed in 13/14 patients. Stents were implanted with a mean balloon diameter of 10.8mm (SD 3.4mm). The achieved final mean diameter was 9.8mm (mean, SD 2.8mm) with an oversized Coa-index of 1.2. There was no re-coarctation at a mean follow-up of 7.3 months (range 3 to 24), the maximum flow velocity of 2m/s across the stented lesion assessed by ECHO.

CONCLUSION

This hybrid approach is an easy and safe concept to manage recurrent aortic arch hypoplasia and stenosis. The use of large stents allows redilatation to adult size diameters later on.

Procedural Outcome and One Year Follow up of Patients Undergoing Endovascular Stenting for Coarctation of Aorta: A Single Center Study

INTRODUCTION

Coarctation of aorta is the fourth most common cardiac lesion requiring intervention. While surgery used to be the only treatment option, endovascular intervention is now considered the first option in simple coarctation lesions. Despite increased popularity, there are currently no FDA approved stents for use in coarctation of aorta and data on the outcome of this procedure is still sparse.

METHODS

Between October 2004 and June 2010, 33 patients who underwent treatment with Cheatham-Platinum stents for coarctation of aorta were retrospectively studied. All the patients underwent control CT scans at 6 month and echocardiography at 1 year follow-up.

RESULTS

There were 17 females and 16 males with a mean age of 26.64 ± 16.30 years (range 2-71 years). The mean stent length and balloon diameter were 3.18 ± 0.56 mm and 15.7 ± 3.12 mm respectively. We achieved an immediate success rate of 96.9% with the only complication of aortic rupture which led to our single mortality in this series. At 6 month follow up no complications were noted in the CT scans. The mean echocardiographic aortic arch gradient at one year follow up was 21.73 ± 11.06 mmHg.

CONCLUSION

This study is one of the few cohorts of patients with stenting for coarctation of aorta in Iranian population which comprised a diverse group of patients from early childhood to elderly. It was demonstrated in this study that stenting for coarctation of aorta is a safe and effective procedure if done carefully and performed in selected patients.

Compression, distortion and dislodgement of large caliber stents in congenital heart defects caused by cardiopulmonary resuscitation: a case series and review of the literature

Stenting of vascular, extracardiac or lately intracardiac stenosis has become an established interventional treatment for a variety of problems in congenital or acquired heart disease. Most stent procedures are completed successfully and the long-term outcome is favorable in the majority of cases. Stent collapse or deformation is a well recognized entity in peripheral stents and can be attributed to insufficient radial force; it can also be attributed to excessive external forces, like deformation of stents in the right ventricular outflow tract, where external compression is combined with continuous movement caused by the beating heart. The protection of the thoracic cage may prove to be insufficient in extraordinary circumstances, such as chest compression in trauma or cardiopulmonary resuscitation (CPR). In this case series, we describe three patients in whom large endovascular stents were placed to treat significant stenosis of the aorta, the aortic arch or the venous system of the inferior vena cava close to the atrium. In all patients, CPR was necessary during their clinical course for various reasons; after adequate CPR, including appropriate chest compression all patients survived the initial resuscitation phase. Clinical, echocardiographic as well as radiologic re-evaluation after resuscitation revealed significant stent distortion, compression, displacement or additional vascular injury. The possibility of mechanical deformation of large endovascular stents needs to be considered and recognized when performing CPR; if CPR is successful, immediate re-evaluation of the implanted stents--if possible by biplane fluoroscopy--seems mandatory.

Covered stents in the management of native coarctation of the aorta--intermediate and long-term follow-up

OBJECTIVES

To evaluate the results of covered Cheatham-Platinum stent implantation in the management of native coarctation of the aorta and report intermediate and long-term follow-up.

BACKGROUND

Covered stents are being used increasingly in severe and complex coarctation of the aorta mainly to reduce risk of aortic wall complications. There is, however, limited data on the intermediate and long-term outcome.

PATIENTS AND METHODS

Fifty-six patients received 59 covered Cheatham-Platinum stents (January 2002-December 2011) at a single center-in 54 patients as primary treatment and in 2 as a rescue. Mean age was 22.25 ± 1.2 (11-56) years and mean weight 58.6 ± 2.1 (32-99) kg. Primary end points were reduction in systolic pressure gradient and an increase in coarctation segment diameter. Changes in antihypertensive medicines and complications were recorded on follow-up.

RESULTS

Mean coarctation segment diameter increased from 4.69 ± 0.20 to 15.1 ± 3.2 mm (P < 0.0001). The systolic gradient decreased from mean of 51.4 ± 3.4 to 4.6 ± 0.7 mm Hg (P < 0.0001). There was one death 3 days postprocedure due to cerebral anoxia. There was one dissection diagnosed 24-hr postprocedure. At a mean follow-up of 45.9 ± 3.9 (3-120) months, all stents were patent and in good position on computed tomography. Four (7.1%) patients underwent successful redilation. Antihypertensive medication was decreased or stopped in 37 (66%) patients.

CONCLUSIONS

Covered Cheetham-Platinum stents may be used effectively as therapy of choice in selected patients with severe coarctation of the aorta. Aortic wall complications occur even with covered stents. Covered stents provide a safe alternative to conventional stenting in the intermediate and long-term and can be redilated safely to keep pace with somatic growth.

Stenting Options for Coarctation of the Aorta

The narrowing of the lumen in coarctation of the aorta can be relieved with a high degree of immediate success by transcatheter methods. All methods are associated with immediate and longer-term complications, including dissection, aneurysm formation, and recoarctation. The introduction of the use of covered stents in aortic coarctation is encouraging because the material cover provides additional protection to the acutely disrupted aortic wall and can provide long-term protection of the dilated segment and the downstream area of poststenotic dilation. This review discusses the currently available options for stenting aortic coarctation.

Coarctation of the Aorta Stent Trial (COAST): study design and rationale

BACKGROUND

Coarctation of the aorta (CoA) accounts for 4% to 5% of congenital cardiac abnormalities. Stent therapy has become an accepted alternative to surgery for older children and adults, although there are no balloon-expandable stents approved by the Food and Drug Administration for use in the aorta. The Cheatham-Platinum (CP) stent was designed for CoA therapy and is widely used outside the United States. We have designed the first prospective trial of stent therapy for CoA to serve as the pivotal trial for Food and Drug Administration approval of the CP stent.

METHODS

The COAST study is a prospective, multicenter, single-arm clinical study. The population includes patients with native or recurrent CoA. Four primary outcome variables were defined. For each variable, the stent will be compared to performance guidelines derived from surgical experience. The first efficacy outcome is reduction in arm-leg systolic blood pressure gradient, and the second is reduction in hospital length of stay. Safety outcomes include the following: the occurrence of any serious or somewhat serious adverse event attributed to the stent or implantation procedure and the occurrence of postprocedure paradoxical hypertension. A total of 105 patients treated with the CP stent will be enrolled.

DISCUSSION

To ascertain the effectiveness and safety of an interventional device, randomized controlled trials have been offered as the criterion standard. However, these trials are not well suited to study rare conditions such as CoA, especially once the therapy in question has received acceptance within the medical community. New clinical trial and statistical approaches are needed to evaluate such therapies. The COAST study is an example of this kind of innovative trial design.

Use of a self-expanding custom-made stent graft to treat lateral tunnel leak, stenosis, and fenestration in the Fontan pathway

A 12-year-old girl with hypoplastic right heart, double inlet left ventricle, and transposition of the great arteries had a lateral tunnel Fontan operation 8 years previously. She developed symptoms related to a combination of stenosis in the inferior caval venous pathway, a fenestration, and leak in the lateral tunnel. These were successfully treated with a custom-made stent graft.

Large-diameter graft-stent (Advanta V12) implantation in various locations: early results

OBJECTIVES

Transcatheter stent placement carries the risk of cardiovascular aneurysm or rupture. Covered stent implantation reduces these risks. The recently marketed Advanta V12 large-diameter-covered stent is pre-mounted and requires 9 (8)-11 Fr delivery systems. The aim was to report on the early results of the treatment of various cardiovascular obstructions by the implantation of a new polytetrafluoroethylene-covered stent (V12).

METHODS

Graft stents on balloons with a diameter (12, 14, 16 millimetres) sufficient to anchor the stent in various obstructions (congenital aortic coarctation, n = 5; obstruction after ascending aorta repair, n = 2; pulmonary arteries, n = 5; inferior caval vein, n = 1; atretic superior caval vein, n = 1; pulmonary vein obstruction, n = 1; and right ventricular outflow tract, n = 1) were implanted using the smallest available delivery system. Secondary dilation with larger-diameter balloons was performed when the residual pressure was gradient, the stent-vessel wall relationship or stent re-coiling due to different reasons needed a re-intervention by pure ballooning or second stent placement.

RESULTS

All 16 patients aged 5-46 years underwent V12 implantation. The variability of the treated lesions and the need for additional interventions were responsible for large ranges in fluoroscopy time between 7.3 to 48.2 minutes (median 17.3). Considering the additional procedures, the V12 stent achieved the desired result in all cases. There were no major complications. At short-term median follow-up of 2 months, all patients are alive and well with no evidence of stent failing.

CONCLUSION

These initial results show that the covered Advanta V12 large-diameter stent is safe and effective in the immediate treatment of various cardiovascular obstructions. Long-term follow-up is required.

Cheatham-Platinum stent implantation for pulmonary artery stenosis in children and adolescents: immediate and mid-term outcome

BACKGROUND

NuMED Cheatham-Platinum (CP) stent implantation for pulmonary artery stenosis in children and adolescents has been rarely reported. This study aimed to evaluate the immediate and mid-term results of CP stent implantation for the treatment of pulmonary artery stenosis associated with congenital heart disease (CHD) in children and adolescents.

METHODS

From August 2005 to May 2007, four consecutive pediatric patients with pulmonary artery stenosis associated with CHD underwent CP stent implantation. They were followed up, and transthoracic echocardiography was done for outcome evaluation.

RESULTS

In the four patients, 5 stent placement procedures were performed and 7 CP stents were implanted (8-zig, 22-39 mm in length). All stents except one were successfully placed in the target lesions without displacement during the procedures. After the procedure, the systolic pressure gradient across the stenosis decreased from 36.67 ± 20.08 to 3.67 ± 3.20 mmHg (P=0.005), and the narrowest diameter of the stenotic segment increased from 6.97 ± 2.22 to 13.40 ± 4.40 mm (P=0.013). Two stents implanted in the left and right pulmonary arteries in patient 4 developed intrastent restenosis 6 months after the procedure, and the distal end of the main pulmonary artery also developed restenosis 26 months later. The results of the remaining stents have been stable without complications during a median follow-up of 34 months (range, 26-48 months).

CONCLUSIONS

Our experience indicates that CP stent implantation is suitable for the treatment of pulmonary artery stenosis in children and adolescents with CHD. The immediate and mid-term results are encouraging, but long-term results demand further follow-up in more cases.

Coarctation of the aorta treated with the Advanta V12 large diameter stent: acute results

OBJECTIVES

To report on the early results of treatment of coarctation of the aorta by dilation with a new polytetrafluoroethylene covered stent.

BACKGROUND

Transcatheter dilation of aortic coarctation carries the risk of aneurysm or rupture. Covered stent implantation reduces this risk but requires a large delivery system. The Advanta V12 LD covered stent is premounted and requires a 9-11 Fr delivery system.

METHODS

Covered stents on balloons of a diameter sufficient to anchor the stent in the coarctation were implanted using the smallest available delivery system. Secondary dilation with larger diameter balloons was performed until the pressure gradient was <20 mm Hg and the stent was opposed to the aortic wall.

RESULTS

Twenty-five patients with aortic coarctation underwent stent implantation. Coarctation diameter increased from (6.3 + or - 3.5) mm to (14.4 + or - 2.3) mm (P < 0.0001). Peak pressure gradient decreased from (25.3 + or - 11.6) mm Hg to (2.5 + or - 3.0) mm Hg (P < 0.0001). The stent achieved the desired diameter in all cases. There were no complications. At short-term median follow-up of 4.9 months, all patients are alive and well with no evidence of recoarctation or aneurysm.

CONCLUSIONS

These initial results show that the covered Advanta V12LD stent is safe and effective in the immediate treatment of coarctation of the aorta through a low profile delivery system of 8-11 Fr. Long term follow up is required.