Histological findings after angioplasty using conventional balloon, radiofrequency thermal balloon, and stent for experimental aortic coarctation

Comparative Analysis of Surgical and Endovascular Approaches for Isolated Aortic Coarctation Repair across Age Groups: Outcomes and Long-Term Efficacy

Background: Aortic coarctation, a condition characterized by localized narrowing of the aorta, can be managed with either surgical or endovascular techniques. This study aims to compare these approaches concerning long-term outcomes, particularly re-coarctation rates and late arterial hypertension. Methods: We retrospectively analyzed data from patients with native, isolated aortic coarctation treated by surgical or endovascular methods between 2015 and 2024. Clinical and demographic data were collected from electronic health records. Blood pressure was measured using oscillometric devices, and transthoracic echocardiography (TTE) was performed by an experienced sonographer. The primary endpoint was to identify which treatment predicted re-coarctation during follow-up, while the secondary endpoint assessed the incidence of late arterial hypertension. Results: Sixty-nine patients were included, with a mean age of 18.14 ± 8.18 years (median 16 years; range 8 to 37 years) and a median follow-up of 3 years (range 6 months to 8 years). Of these, 67 (97.1%) underwent elective repairs. Repair techniques included endovascular treatment (24.6%), surgical end-to-end anastomosis (47.8%), and surgical patchplasty (27.5%). The endovascular group was significantly older (29.82 ± 5.9 years vs. 14.33 ± 4.25 years, p = 0.056) and had shorter procedure durations and hospital stays. One-year freedom from reintervention was significantly higher in the surgical group (98.7%) compared to the endovascular group (88.23%) (p < 0.001). Conclusions: Both techniques effectively treat aortic coarctation, but surgical repair offers better long-term outcomes, while endovascular repair provides shorter recovery times. These findings should inform the choice of treatment modality based on patient-specific factors and clinical priorities.

Histopathological evaluation of aortic coarctation after conventional balloon angioplasty in neonates

BACKGROUND

Optimal management strategy for native aortic coarctation in neonates and young infants is still a matter of debate. The surgical procedure, histopathologic research, and clinical outcome in 15 neonates who underwent surgery after successful balloon angioplasty is the basis of this study.

METHOD

Between 01 October, 2014 and 01 August, 2017, we enrolled 15 patients with native aortic coarctation for this study. These patients had complications regarding recoarctation, following balloon angioplasty intervention at our institute and other centres. Surgically extracted parts were examined histopathologically and patient's data were collected retrospectively.ResultThe reasons for recurrence of recoarctation after balloon angioplasty are as follows: patients with higher preoperative echocardiographic gradients had recoarctation earlier, neointimal proliferation, aortic intimal fibrosis at the region of ductal insertion, and ductal residual tissue debris after balloon angioplasty. No repeat intervention was required in the 15 patients who underwent surgery followed by balloon angioplasty. Early mortality was seen in one patient after surgery. Postoperative complication in the surgical group occurred in the form of chylothorax in one patient.

CONCLUSION

In centres in which the neonatal ICU is inexperienced, balloon angioplasty is particularly recommended. In developing neonatal clinics, balloon angioplasty, when performed on patients at their earliest possible age, delays actual corrective operation to a later date, which in turn provides less risky surgical outcomes in infants who are gaining weight, growing, and do not have any haemodynamic complaints.

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.

Airway smooth muscle as a target in asthma and the beneficial effects of bronchial thermoplasty

Airflow within the airways is determined directly by the lumenal area of that airway. In this paper, we consider several factors which can reduce airway lumenal area, including thickening and/or active constriction of the airway smooth muscle (ASM). The latter cell type can also contribute in part to inflammation, another feature of asthma, through its ability to take on a synthetic/secretory phenotype. The ASM therefore becomes a strategically important target in the treatment of asthma, given these key contributions to the pathophysiology of that disease. Pharmacological approaches have been developed to elicit relaxation of the ASM, but these are not always effective in all patients, nor do they address the long-term structural changes which impinge on the airway lumen. The recent discovery that thermal energy can be used to ablate smooth muscle has led to the development of a novel physical intervention—bronchial thermoplasty—in the treatment of asthma. Here, we review the evolution of this novel approach, consider some of the possible mechanisms that account for its salutary effects, and pose new questions which may lead to even better therapies for asthma.

Endovascular management of coarctation of the aorta

Untreated thoracic aortic coarctation leads to early death predominantly because of hypertension and its cardiovascular sequelae. Surgical treatment has been available for > 50 years and has improved hypertension and survival. More recently, endovascular techniques have offered a minimally invasive alternative to traditional open repair. Early and intermediate results suggest angioplasty and stenting have an important role in the management of aortic coarctation, particularly in adults and older children.

Reduction of arterial graft smooth muscle mass by moderate heat therapy

Radial artery (RA) graft spasm is a major cause of early graft failure in coronary artery bypass grafting surgeries. We explored the feasibility of thermal reduction of smooth muscle mass to attenuate vasoconstriction. Rat and rabbit femoral arteries were treated thermally in situ (45°C to 65°C; 0 s to 120 s) and then excised at various time points for histological and physiological study (pressure-diameter relationships). Human radial arteries were treated in vitro and studied in similar fashion. Weeks after thermal treatment, no overt indication was noted of vasospasm, thrombosis, or scarring in the arterial wall; however, this intervention led to a thermal dose-dependent reduction of vasoconstriction (to phenylephrine or potassium chloride) and to a conspicuous loss of smooth muscle. Pressure-diameter relationships showed no aneurismal dilation of these demuscularized arteries up to 200 mmHg. Qualitatively identical results were obtained in human radial arteries. Thermal ablation of RAs may provide a simple, safe, and effective solution to postsurgical vasospasm.

Stent implantation for coarctation of the aorta in children <30 kg

OBJECTIVES

Our aim was to determine key characteristics of stents commonly implanted in the aorta through bench testing and to describe our technique and acute results in patients weighing <30 kg.

BACKGROUND

Despite the increasing use of stents for interventional treatment for coarctation of the aorta (CoA) in larger patients, use of large stents is controversial in small children.

METHODS

Methods included bench testing of large stents, and retrospective review of all patients over 1 year of age who had stent implantation for treatment of CoA. Patients were divided into 2 groups based on weight. Paired comparisons were made before and after stent implantation, and group outcomes were compared.

RESULTS

Sixty patients comprised the entire sample, with 22 patients assigned to group I (<30 kg) and 38 patients assigned to group II (>or=30 kg). The mean minimum diameters of the CoA (group I 5.0 to 10.7 mm; group II 8.0 to 15.0 mm) and the ratio of the coarctation diameter to the descending aorta diameter measured at the level of the diaphragm (CoA/DAo ratio) (group I 0.4 to 0.93; group II 0.46 to 0.94) increased significantly in both groups (all p < 0.05). The mean systolic gradient decreased significantly in both groups (group I 23.0 to 2.0 mm Hg; group II 24.0 to 2.8 mm Hg; both p = 0.001). No difference was found between the groups in the CoA/DAo ratio, residual systolic gradients, or the decrease in systolic gradient after stent implantation. There were no significant complications in patients under 30 kg.

CONCLUSIONS

As in larger patients, use of large stents for treatment of CoA in small children is effective and safe in the short term. In these patients, stent redilations will be required, and follow-up is ongoing.

Use of covered stents to treat coarctation of the aorta

Transcatheter treatments for coarctation of the aorta include balloon angioplasty and stent implantation. However, balloon angioplasty has its limitations and may be associated with complications, such as, recoarctation, dissection, and aneurysm formation, in adult patients. Bare metal stent implantation has offered an alternative during the last decade or so, but covered stents have been used with increasing frequency more recently, to the extent that covered stent implantation is the preferred treatment in correctly selected patients. Primary stent insertion, whether bare metal or covered, prevents elastic recoil of the aorta and may provide better and more predictable results than balloon angioplasty. Furthermore, stents are preferable for the treatment of complex aortic arch obstructions, but their usage is limited to older patients, because of limitations associated with growth.

Pediatric cardiac interventions

The field of pediatric cardiac interventions has witnessed a dramatic increase in the number and type of procedures performed. We review the most common procedures performed in the catheter laboratory. Lesions are divided according to their physiological characteristics into left-to-right shunting lesions (atrial septal defect, patent ductus arteriosus, ventricular septal defect), right-to-left shunting lesions (pulmonary stenosis, pulmonary atresia/intact ventricular septum), right heart obstructive lesions (peripheral arterial pulmonic stenosis, right ventricular outflow tract obstruction), and left heart obstructive lesions (aortic valve stenosis, coarctation of the aorta). In addition, a miscellaneous group of lesions is discussed.

Long-term (up to 20 years) results of percutaneous balloon angioplasty of recurrent aortic coarctation without use of stents

AIMS

To assess the efficacy, safety, and long-term results of the balloon angioplasty of recoarctation.

METHODS AND RESULTS

The angioplasty was performed in 99 consecutive patients aged 36 days to 32.6 years (median 268 days). Recoarctation to descending aorta diameter ratio increased from 0.44 (0.35/0.50) to 0.66 (0.57/0.77), P < 0.001. Systolic gradient was reduced from 34.0 (26.0/44.75) to 15.0 (8.25/27.0) mmHg, P < 0.001. In seven patients (7.1%) the procedure was ineffective. One patient (1%) with heart failure died within 24 h after a successful angioplasty and in another (1%) an intimal abruption necessitated surgical revision. The follow-up ranged up to 20.7 years (median 8.1 years). Actuarial probability of survival 20.7 years after the procedure was 0.91, and of reintervention-free survival was 0.44. Older age at the angioplasty was associated with a higher incidence of reinterventions (hazard ratio 1.057; 95% confidence interval 1.012-1.103; P = 0.010). The type of surgery and the recoarctation anatomy did not influence the outcome. In 69 patients aneurysm formation was studied by high-sensitive methods with only one positive finding per 462 patient-years.

CONCLUSION

Angioplasty is safe and effective regardless of the type of surgery used and the recoarctation anatomy. Older age at the angioplasty is associated with a higher incidence of reinterventions.

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta

BACKGROUND

We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques.

METHODS AND RESULTS

Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up.

CONCLUSIONS

Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Analysis of arterial intimal hyperplasia: review and hypothesis

BACKGROUND

Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology?

HYPOTHESIS

I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it "benign intimal hyperplasia". However, normal or "benign" intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates early in life to form a multi-layer intimal hyperplasia and then continues to self-renew in a controlled manner throughout life, relatively rarely compromising the blood supply to the heart, causing complications requiring intervention only in a small fraction of the population, while all humans are carriers of benign hyperplasia. Unfortunately, this fundamental fact has not been widely appreciated in arteriosclerosis research and medical education, which continue to operate on the assumption that the normal arterial intima is always an "ideal" single-layer endothelium. As a result, the disease is perceived and studied as a new pathological event caused by new mechanisms. The discovery that normal coronary arteries are morphologically indistinguishable from deadly coronary arteriosclerosis continues to elicit surprise.

CONCLUSION

Two questions should inform the priorities of our research: (1) what controls switch the single cell-layer intimal phenotype into normal hyperplasia? (2) how is normal (benign) hyperplasia maintained? We would be hard-pressed to gain practical insights without scrutinizing our premises.

The results of catheter-based therapy compared with surgical repair of adult aortic coarctation

A review was performed to compare the results of endovascular therapy (stenting and angioplasty) with surgical techniques to repair adult aortic coarctation. The immediate improvement in hypertension and the morbidity were similar across all groups. Surgical therapy was associated with a very low risk of restenosis and recurrence, whereas endovascular therapy had a much higher incidence of restenosis and the need for repeat interventions. The long-term outcome of endovascular approaches will need to be assessed in the future.

Congenital heart disease never goes away, even when it has been 'treated': the adult with congenital heart disease

PURPOSE OF REVIEW

As the specialties of pediatrics and pediatric cardiology continue to forge ahead with better diagnoses, medical care, and surgical results, an expanding population of patients with congenital heart disease (CHD) outgrows the pediatric age group, yet does not quite graduate to routine adult cardiology or general medicine. The adult with congenital heart disease (ACHD) faces medical, surgical, and psychosocial issues that are unique to this population and must be addressed as such. This review attempts to discuss and highlight some of the important advances and controversies brought up in the past year, in the care and management of these patients.

RECENT FINDINGS

The past five to 10 years have seen dynamic interest in understanding sequelae of corrected, uncorrected, or palliated congenital heart disease. The search for the ideal surgery, optimal prosthesis, and a smooth transition to adult care continues and is reflected in the vast amount of academic work and publications in this field. Of particular interest, conduit reoperations and single ventricle pathway modifications are still an art and a science in evolution.

SUMMARY

While all are agreed that there is a pressing need to focus on the delivery of care to the adult with congenital heart disease, this essentially requires a clearer understanding of late sequelae of CHD. The sheer heterogeneity of anatomy, age, surgery, and institutional management protocols can make it difficult to develop clear guidelines. This review attempts to give an up-to-date perspective on some of the new findings related to the more common lesions and problems faced in this group.