Idiopathic mid-aortic syndrome in children

Renal Artery Stenosis and Mid-Aortic Syndrome in Children-A Review

Background: Renal artery stenosis (RAS) and mid-aortic syndrome (MAS) are significant yet under-recognized causes of pediatric hypertension. RAS is characterized by the narrowing of the renal arteries, while MAS involves the stenosis of the abdominal aorta along with its associated vessels. The etiologies of RAS and MAS often involve genetic factors and acquired conditions such as fibromuscular dysplasia and Takayasu arteritis, contributing to their complex clinical presentations. Despite advancements in diagnostic imaging, challenges remain in effectively identifying these conditions. Pharmacological treatment can achieve partial blood pressure control, but it usually does not lead to complete recovery. Treatment options range from angioplasty to more definitive surgical interventions such as renal artery reimplantation and aorto-aortic bypass, tailored according to the specific pathology and extent of the disease. Methods: This review explores the diagnosis and management of RAS and MAS in children, highlighting the necessity for early detection and showcasing the evolving landscape of treatment. Conclusions: We advocate for a multidisciplinary approach that includes advanced imaging for effective diagnosis and tailored therapy. By integrating the latest research and clinical practices, this article provides valuable insights into managing complex vascular conditions in the pediatric population, ultimately aiming to enhance the quality of life for affected individuals.

Mid-aortic syndrome presented as dilated cardiomyopathy

Mid-aortic syndrome (MAS) is a rare vascular disease that usually leads to renovascular hypertension. With the predominant manifestations being intractable arterial hypertension and lower extremity arterial insufficiency, it has rarely been associated with dilated cardiomyopathy. We report a young girl with congestive heart failure, where the cause was initially attributed to dilated cardiomyopathy. A repeated echocardiogram 6 months later brought the physician's suspicion of MAS because of the abnormal colour of Doppler from the subcostal view. Further assessment using CT angiography revealed discrete thoracic coarctation at the level of T10, with the narrowest diameter of 2.1 mm, thus confirming the diagnosis. Her inflammatory markers and connective tissue screening were negative. She underwent successful stenting of coarctation of the aorta, which later caused improvement in her cardiac function. We highlighted the importance of looking for treatable causes of dilated cardiomyopathy and vigilant clinical and echocardiogram assessment with high suspicion to diagnose MAS.

Pediatric hypertension caused by congenital abdominal aortic stenosis: A case image report

We confirm that the cause of hypertension in this pediatric patient is congenital abdominal aortic stenosis. This case serves as a reminder to be vigilant for the possibility of congenital vascular abnormalities leading to hypertension in children.

Case report: Personalized transcatheter approach to mid-aortic syndrome by in vitro simulation on a 3-dimensional printed model

An 8-year-old girl, diagnosed with mid-aortic syndrome (MAS) at the age of 2 months and under antihypertensive therapy, presented with severe systemic hypertension (>200/120 mmHg). Computed tomography (CT) examination revealed aortic aneurysm between severe stenoses at pre- and infra-renal segments, and occlusion of principal splanchnic arteries with peripheral collateral revascularization. Based on CT imaging, preoperative three-dimensional (3D) anatomy was reconstructed to assess aortic dimensions and a dedicated in vitro planning platform was designed to investigate the feasibility of a stenting procedure under fluoroscopic guidance. The in vitro system was designed to incorporate a translucent flexible 3D-printed patient-specific model filled with saline. A covered 8-zig 45-mm-long Cheatham-Platinum (CP) stent and a bare 8-zig, 34-mm-long CP stent were implanted with partial overlap to treat the stenoses (global peak-to-peak pressure gradient > 60 mmHg), excluding the aneurysm and avoiding risk of renal arteries occlusion. Percutaneous procedure was successfully performed with no residual pressure gradient and exactly replicating the strategy tested in vitro. Also, as investigated on the 3D-printed model, additional angioplasty was feasible across the frames of the stent to improve bilateral renal flow. Postoperative systemic pressure significantly reduced (130/70 mmHg) as well as dosage of antihypertensive therapy. This is the first report demonstrating the use of a 3D-printed model to effectively plan percutaneous intervention in a complex pediatric MAS case: taking full advantage of the combined use of a patient-specific 3D model and a dedicated in vitro platform, feasibility of the stenting procedure was successfully tested during pre-procedural assessment. Hence, use of patient-specific 3D-printed models and in vitro dedicated platforms is encouraged to assist pre-procedural planning and personalize treatment, thus enhancing intervention success.

Aorto-aortic bypass in an infant with middle aortic syndrome and Marfan syndrome: a 15-year follow-up

We present a 15-year follow-up after aorto-aortic bypass surgery in a 7-month-old infant with middle aortic syndrome and confirmed Marfan syndrome. In anticipation of her growth, the length of the graft was adjusted to the anticipated length of the narrowed aorta in her adolescence. In addition, her height was controlled by oestrogen, and her growth was stopped at 178 cm. To date, the patient is free from aortic reoperation and lower limb malperfusion.

Editor's Choice - Therapeutic Options and Outcomes in Midaortic Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE

Midaortic syndrome (MAS) is narrowing of the distal thoracic and or abdominal aorta with congenital, inflammatory, or idiopathic aetiology. If left untreated, the prognosis is poor due to hypertensive complications. Follow up data after treatment are sparse, contrary to aortic coarctation. This study aimed to investigate hypertension during follow up after medical, endovascular, and surgical therapy in juveniles and adults.

DATA SOURCES

A meta-analysis of case series and reports was performed, focusing on the incidence of hypertension during the follow up of juvenile (i.e., age 0-17 years) and adult MAS patients after medical, endovascular, or surgical therapy.

REVIEW METHODS

Search queries were performed in PubMed, Embase, and Web of Science, and eligible articles underwent quality control. Descriptive statistics were reported based on available data, and individual patient data meta-analyses were performed using a one stage approach, accounting for clustering by case series or decades of reporting for case reports. For the meta-analysis, missing outcome and aetiology data were multiply imputed.

RESULTS

The number of juveniles and adults who underwent endovascular therapy (33.7% vs. 27.3%; p = .42) and surgery (52.2% vs. 58.0%; p = .46) was similar. At baseline, 92.4% of juveniles and 87.5% of adults were hypertensive, decreasing to 23.2% and 24.1% during a follow up of 23 months (juveniles) and 18 months (adults), respectively. More hypertension was found compared with surgery in juveniles after endovascular therapy (38.1% vs. 10.8%; p = .020). Meta-analysis also demonstrated a trend for hypertension after endovascular therapy in juveniles, whereas hypertension was more prevalent following surgery in adults compared with endovascular therapy or medication.

CONCLUSION

This review and meta-analysis investigated therapeutic options for MAS in juveniles and adults. It found that complications and hypertension during follow up were more common in juveniles after endovascular treatment, whereas surgery in adults was associated with more hypertension.

Mid-aortic Syndrome in a Pediatric Cohort

Mid-aortic syndrome (MAS) is an uncommon condition characterized by severe narrowing of the abdominal aorta, usually involving visceral and renal arteries. Most patients are asymptomatic and typically present with incidental hypertension which might evolve into end-organ damage if untreated. Our aim was to review 8 new pediatric MAS cases. A retrospective observational study of all pediatric patients with MAS diagnosis (April 1992-November 2021) was conducted. Patients underwent systematic evaluation (medical and family history; 12-lead electrocardiogram; echocardiogram; angiography and/or computed tomography or magnetic resonance angiography). 8 pediatric patients with MAS were included. Median age at diagnosis was 2.6 [0.2-4.7] years; median follow-up time was 8.6 [6.6-10.0] years. 6/8 patients presented with incidental hypertension, 1/8 with heart murmur, and 1/8 with heart failure symptoms. All patients were on antihypertensive treatment. 1/8 patients underwent surgery and 7/8 an endovascular treatment. At the end of the study period, among the 6 patients that underwent a successful endovascular procedure, 2 achieved good blood pressure (BP) control, 2 acceptable BP control, 1 stage 1 hypertension and, another, stage 2 hypertension. There was 1 death during follow-up. BP monitoring in pediatric patients is crucial for early recognition of MAS. Treatment should be based on the individual clinical characteristics of patients with careful planning of surgical revascularisation, if possible, after adult growth is completed. Our study demonstrates that endovascular treatment might be a good alternative to surgery. Nevertheless, further trials with larger sample size and longer-term follow-up are required to determine the best treatment approach.

ELN missense variant in patient with mid-aortic syndrome case report

BACKGROUND

Mid-aortic syndrome (MAS) is characterized by the congenital coarctation of the abdominal aorta, abdominal and limb claudication, and hypertension. The etiology of this disorder is very diverse and often manifests in conjunction with Takayasu's arteritis, Williams-Beurens syndrome, and neurofibromatosis. The isolated mid-aortic syndrome is very rare with only a few cases reported in the literature.

CASE PRESENTATION

A 45 years old man was admitted to the Emergency Department with sudden muscle weakness and facial paralysis on the left side. Imaging studies reveal right middle cerebral artery infarction at the M1 section. Incidental findings include multiple moderate to severe stenoses in the right internal carotid artery, and total abdominal aorta occlusion. A variant at the ELN gene (Elastin, OMIM*130,160): c.1768G > A/wt (p.Ala590Thr) was identified.

CONCLUSION

This is the first reported case of ELN related mid-aortic syndrome in Vietnam which was diagnosed through careful clinical and genetic workup. The finding of mid-aortic syndrome, in this case, was incidental and the decision to reverse the occlusion was postponed as there was no immediate risk of renal failure or reduced blood flow to the lower limb.

Treatment of 12-year-old girl with midaortic syndrome by using Cook Formula stent

Middle aortic syndrome is a severe form of aortic coarctation and mostly involves the thoracic and abdominal part of the aorta. Traditional surgical approach has some potential risks and repetitive operations. Percutaneous stent implantation is a feasible and safe method for the palliation of middle aortic syndrome in childhood. Herein, a child with middle aortic syndrome was presented who has been treated by transcatheter stent implantation.

Percutaneous cutting balloon angioplasty for the treatment of renovascular hypertension in children and adolescents

OBJECTIVE

Percutaneous transluminal renal angioplasty (PTRA), the recommended treatment in children with renovascular hypertension (RVH), often has unsatisfactory outcomes. Cutting balloons may improve the results of angioplasty in different vascular beds with complex and resistant lesions. We retrospectively analysed the effects of percutaneous cutting balloon angioplasty (PCBA) on blood pressure, cardiac mass and renal artery acceleration time in children/adolescents referred to our centre for RVH.

PATIENTS AND METHODS

Thirteen patients (aged 9-19 years) with renal artery stenosis (RAS) and severe hypertension were identified. RASs were focal fibromuscular (FMD) or FMD-like dysplasia (in six cases bilateral, in five associated with mid aortic syndrome). Ten patients had uncontrolled hypertension, in nine cases associated with left ventricular hypertrophy (LVH). Acceleration time was abnormal in all stenotic arteries. Eighteen PCBA were performed, in three arteries associated with stent implantation.

RESULTS

PCBA was technically successful in all individuals without major complications. In one patient, an intra-stent restenosis occurred, successfully redilated with conventional angioplasty without recurrence at 4 years distance. One year after PCBA, mean SBP and DBPs were markedly reduced from 146 ± 25 to 121 ± 10 mmHg and from 87 ± 11 to 65 ± 12 mmHg, respectively (P < 0.001 for both). At that time, hypertension was cured in seven children and controlled in five individuals. This favourable outcome was confirmed with ambulatory blood pressure measurement in four patients. At the latest follow-up, left ventricular mass and acceleration time were normal in all patients.

CONCLUSION

PCBA proved to be a well tolerated and effective procedure that can be considered as an alternative to PTRA to treat hypertensive children/adolescents with recurrent or resistant RAS.

Successful Surgical and Endovascular Multidisciplinary Therapy for Mid-aortic Syndrome with Complicated Atherosclerotic Comorbidities in an Older Patient

Mid-aortic syndrome (MAS) is a rare vascular disorder that causes refractory hypertension. A 76-year-old woman was hospitalized for acute heart failure (HF) with drug-resistant hypertension; other comorbidities included epigastric artery rupture, old myocardial infarction, an intraventricular thrombus, and a cerebral artery aneurysm. Angiography revealed severe narrowing of the descending aorta, which led to the diagnosis of MAS. Although intensive medical treatment improved her HF, optimal blood pressure (BP) could not be achieved. Percutaneous coronary intervention and surgical bypass for diseased aorta was then performed in two stages, resulting in the achievement of optimal BP and alleviation of HF.

HISTOLOGIC AND MORPHOLOGIC CHARACTER OF PEDIATRIC ABDOMINAL AORTIC DEVELOPMENTAL COARCTATION AND HYPOPLASIA

OBJECTIVES

Abdominal aortic coarctation and hypoplasia are uncommon diseases, recognized most often in pediatric-aged individuals. Comprehensive studies regarding the pathologic spectrum of these aortopathies are nonexistent. This investigation was undertaken to better define the histologic and morphologic character of abdominal aortic narrowings affecting children and assess its potential relevance to contemporary clinical practice.

METHODS

Aortic specimens obtained during open operations in children being treated for symptomatic, noninflammatory abdominal aortic narrowings at the University of Michigan were subjected to histologic study following hematoxylin-eosin, Movat, Verhoeff Van Gieson, and Masson's trichrome preparations. Microscopic findings were correlated with the anatomic aortic images. In addition, a detailed review was completed of all prior reports in the English literature that included images depicting the histologic character of noninflammatory abdominal aortic narrowings in children.

RESULTS

Among a series of 67 pediatric-aged individuals undergoing open surgical interventions for abdominal aortic narrowings, eight children ranging in age from 9 months to 18 years, had adequate aortic tissue available for study. The loci of the specimens paralleled the anatomic sites of segmental coarctations observed in the entire series, with involvement of the suprarenal abdominal aorta (3), intrarenal aorta (2), and infrarenal aorta (1). Diffusely hypoplastic abdominal aortas (2) included one case of a de facto aortic duplication, represented by a channel that paralleled the narrow native aorta and gave origin to celiac artery branches, as well as the superior mesenteric and renal arteries. Concentric or eccentric intimal fibroplasia was observed in every aorta, often with internal elastic fragmentation and duplication (4). Media abnormalities included elastic tissue disorganization (3), and focal medial fibrosis (1). Organizing luminal thrombus occurred in two infants. Coexistent ostial stenoses of the celiac, superior mesenteric, or renal arteries were observed in all but the only child who having an infrarenal aortic coarctation. Neurofibromatosis-1 affected one child whose histologic findings were indistinguishable from those of the other children. Review of prior published histologic images of abdominal aortic coarctation and hypoplasia affecting children from other centers revealed a total of 14 separate reports, each limited to single case photomicrographs of which 11 exhibited intimal fibroplasia.

CONCLUSIONS

Intimal fibroplasia is a common accompaniment of developmental abdominal aortic coarctation and hypoplasia. It is posited that intimal fibroplasia, that is likely progressive in instances of abnormal shear stresses in these diminutive vessels, may contribute to less salutary outcomes following endovascular and certain open reconstructions of pediatric abdominal aortic narrowings.

Mid-term outcome of angioplasty for pediatric renovascular hypertension

PURPOSE

To evaluate the mid-term outcome of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH).

MATERIALS AND METHODS

The clinical data of patients who underwent PTRA for RVH in our hospital from 2012 to 2019 were analyzed retrospectively. Post-procedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis and complications were closely followed up.

RESULTS

The procedure of PTRA was performed in total of 30 children (20 males and 10 females), with a mean age of 7.32±0.74 years (40 days ∼13.92 years) and a mean weight of 24.99±2.26 kg (3.4 ∼ 53kg). The median follow-up period was 26.5 months (1 month ∼7.5 years). Technical success was achieved in 26 of 30 patients (86.7%). Three patients (10.0%) developed restenosis. Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. No other complication was found. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 (23.3%) improved. There was no significant difference in etiology, lesion location and length between patients with clinical benefit and failure (p=0.06, 0.202 and 0.06). The GFR of the affected kidney was significantly improved from 19.85±11.24 (ml/min) to 38.09±11.88 (ml/min) at 6 months follow-up after PTRA (p<0.001).

CONCLUSION

The overall results of PTRA for pediatric RVH caused by different etiologies are promising. Not only does it provide clinical benefit of blood pressure control in 73.3% of patients, it also significantly improves the function of the affected kidney.

Midaortic syndrome and renovascular hypertension

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta with or without the involvement of branch vessels. The majority of cases are thought to be idiopathic though MAS has been associated with a number of conditions including granulomatous vasculitis, neurofibromatosis-1 (NF-1), Alagille Syndrome, fibromuscular dysplasia (FMD), and Williams syndrome. Patients typically present with hypertension due to decreased renal perfusion. Less common presentations include renal insufficiency, heart failure, claudication, stroke, and abdominal pain. Imaging modalities help establish the diagnosis of MAS including duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), and angiography. Initial therapy focuses on medical management with antihypertensives prior to intervention. Invasive interventions are indicated when there is evidence of end organ damage or dysfunction such as decreased renal function, poorly growing kidneys, cerebrovascular accident, left ventricular hypertrophy or frank cardiac failure. Endovascular interventions may assist in diagnosis and may treat some lesions although reintervention rates are high. Most patients require some type of surgical intervention, and a variety of surgical options are available based on anatomic findings. Renal revascularization may be accomplished by renal artery bypass, autotransplantation, or renal artery reconstruction. Aortic lesions may be repaired using patch angioplasty or aortoaortic bypass. Mesenteric arteries do not typically require reconstruction as they are rarely symptomatic. More novel options include the use of tissue expanders to lengthen the aorta to allow for primary aortic reconstruction (TESLA) or the use of the meandering mesenteric artery as an autologous aortic bypass graft (MAGIC).

Renovascular hypertension in pediatric patients: update on diagnosis and management

Renovascular hypertension (RVH) is defined as an elevated blood pressure caused by kidney hypoperfusion, generally as a result of anatomic stenosis of the renal artery with consequent activation of the Renin Angiotensin-Aldosterone System. The main causes include genetic and inflammatory disorders, extrinsic compression, and idiopathic alterations. RVH is often asymptomatic and should be suspected in any child with refractory hypertension, especially if other suggestive findings are present, including those with severe hypertension, abdominal bruit, and abrupt fall of glomerular filtration rate after administration of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. There is a consensus that digital subtraction angiography is the gold standard method for the diagnosis of RVH. Nevertheless, the role of non-invasive imaging studies such as Doppler ultrasound, magnetic resonance angiography, or computed tomographic angiography remains controversial, especially due to limited pediatric evidence. The therapeutic approach should be individualized, and management options include non-surgical pharmacological therapy and revascularization with percutaneous transluminal renal angioplasty (PTRA) or surgery. The prognosis is related to the procedure performed, and PTRA has a higher restenosis rate compared to surgery, although a decreased risk of complications. This review summarizes the causes, physiopathology, diagnosis, treatment, and prognosis of RVH in pediatric patients. Further studies are required to define the best approach for RVH in children.

Hypertension in Children and Adolescents with Turner Syndrome (TS), Neurofibromatosis 1 (NF1), and Williams Syndrome (WS)

PURPOSE OF REVIEW

Turner syndrome (TS), neurofibromatosis type 1(NF1), and William Syndrome (WS) are 3 genetic conditions that are all associated with a substantial increase in risk of hypertension. In this review, we focus on factors leading to hypertension and on clinical manifestations and management of hypertension in children and adolescents with these genetic conditions RECENT FINDINGS: In most instances, hypertension is secondary. There is a high prevalence of masked hypertension in TS; however, the extent to which control of the BP helps reduce the risk of aortic dissection/aneurysm in TS is not yet fully elucidated. Vasculopathies are the least emphasized but most important manifestation of NF1. Of note, routine screening for pheochromocytoma in NFI is not recommended as it is not cost-effective. Cardiovascular complications are the major cause of death in patients with WBS. ABPM identifies patients without overt aortic or renovascular narrowing. Antihypertensive agents such as ARBs that have direct vascular wall effects and agents that inhibit oxidative stress (minoxidil) should be considered, even in those who do not exhibit overt hypertension. Elevated blood pressure in children and adolescence manifests early with end-organ changes and when left untreated, increases risk for premature onset of cardiovascular disease. Vigilant monitoring of the blood pressure is recommended. Accurate early diagnosis and management of hypertension will delay or prevent target organ damage and ensure a healthier transition to adulthood among children afflicted with these conditions.

Mid-Aortic Syndrome in Williams-Beuren Syndrome with an Atypical Small-Sized Deletion of Chromosome 7q11.23 Misdiagnosed as Takayasu Arteritis

Mid-aortic syndrome (MAS) is a rare condition characterized by stenosis of the distal thoracic and/or abdominal aorta. Williams-Beuren syndrome (WBS) is a relatively rare cause of MAS. We report a case of incidentally diagnosed MAS caused by WBS without typical manifestations caused by an atypical small-sized deletion in chromosome 7q11.23, which was initially misdiagnosed as Takayasu arteritis.

Renovascular hypertension in children

Paediatric hypertension, defined as systolic blood pressure > 95th percentile for age, sex and height is often incidentally diagnosed. Renovascular hypertension (RVH) is responsible for 5-25% of hypertension in children. Renal artery stenosis and middle aortic syndrome can both can be associated with various conditions such as fibromuscular dysplasia, Williams syndrome & Neurofibromatosis type 1. This paper discusses the approaches to diagnosis and interventional management and outcomes of renovascular hypertension in children. Angiography is considered the gold standard in establishing the diagnosis of renovascular disease in children. Angioplasty is beneficial in the majority of patients and generally repeated angioplasty is considered more appropriate than stenting. Surgical options should first be considered before placing a stent unless there is an emergent requirement. Given the established safety and success of endovascular intervention, at most institutions it remains the preferred treatment option.

Surgical management of pediatric renovascular hypertension and midaortic syndrome at a single-center multidisciplinary program

OBJECTIVE

To evaluate the outcomes of various surgical approaches in the treatment of renovascular hypertension and midaortic syndrome (MAS) in children.

METHODS

We performed a retrospective medical record review of patients who had undergone surgery for renovascular hypertension from 2010 to 2018 at our center under the care of a multidisciplinary team. The operative interventions included mesenteric artery growth improves circulation (MAGIC), tissue expander-stimulated lengthening of arteries (TESLA), aortic bypass using polytetrafluorethylene, renal artery reimplantation, and autotransplantation. The MAGIC procedure uses the meandering mesenteric artery as a free conduit for aortic bypass. The TESLA procedure is based on lengthening the normal distal aorta and iliac arteries by gradual filling of a retroaortic tissue expander for several weeks, followed by resection of the stenotic aorta and subsequent primary reconstruction.

RESULTS

A total of 39 patients were identified, 10 with isolated renal artery stenosis, 26 with MAS, and 3 with systemic inflammatory vasculitis. The median age at presentation and surgery was 6.4 years (range, 0-16.3 years) and 9.3 years (range, 0-9.2 years), respectively. The MAS-associated syndromes included neurofibromatosis type 1 (15.4%) and Williams syndrome (5.1%), although most cases were idiopathic. At surgery, 33.3% had had stage 1 hypertension (HTN), 53.8% stage 2 HTN, and 12.8% normal blood pressure with a median of three antihypertensive medications. Follow-up of 37 patients at a median of 2.5 years demonstrated normal blood pressure in 86.1%, stage 1 HTN in 8.3%, and stage 2 HTN in 5.6%, with a median of one antihypertensive medication for the entire cohort.

CONCLUSIONS

The patterns of vascular involvement leading to renovascular hypertension in children are variable and complex, requiring thoughtful multidisciplinary planning and surgical decision-making. The MAGIC and TESLA procedures provide feasible approaches for aortic bypass and reconstruction using autologous tissues and will result in normalization of blood pressure in 85% of children 2.5 years after surgery.

Fetal congenital midaortic syndrome with unilateral renal artery stenosis prenatally presenting with polyhydramnios and postpartum as hyponatremic hypertensive syndrome

The midaortic syndrome (MAS) is a rare anomaly, characterised by narrowing of the distal aorta and its major branches. The most common symptom is severe arterial hypertension. The combination of hyponatremia, polyuria and renovascular hypertension caused by a unilateral renal artery stenosis is described as hyponatremic hypertensive syndrome. We report a case of MAS with unilateral renal artery stenosis in a preterm female neonate. A pregnant woman at 34 weeks of gestation was referred with fast growing abdominal circumference and pain. The ultrasound revealed severe polyhydramnios and fetal myocardial hypertrophy. Within the first 48 hours of the neonatal period, the diagnosis of MAS was made. We conclude that symptomatic MAS, caused by unilateral renal artery stenosis, resulting in increased renin-angiotensin-aldosterone system activity and subsequent polyuria of the non-stenotic kidney, lead to clinically significant polyhydramnios.

Surgical management of middle aortic syndrome in an adult

Middle aortic syndrome (MAS), a coarctation of the lower thoracic and/or abdominal aorta, is typically diagnosed and treated in the pediatric population. We present a 48-year-old patient with a long-standing history of hypertension who was lost to follow-up owing to a lack of insurance coverage. After two myocardial infarcts owing to severe hypertension, a vascular workup including a computed tomography angiogram revealed a diagnosis of MAS. He underwent open vascular reconstruction with a thoracoabdominal Dacron bypass graft. He was discharged within 1 week with no hypertension or claudication. Adult patients diagnosed with MAS should undergo open or endovascular surgical repair with close follow-up.

Computational analysis of renal artery flow characteristics by modeling aortoplasty and aortic bypass interventions for abdominal aortic coarctation

OBJECTIVE

Suprarenal abdominal aortic coarctation (SAAC) alters flow and pressure patterns to the kidneys and is often associated with severe angiotensin-mediated hypertension refractory to drug therapy. SAAC is most often treated by a thoracoabdominal bypass (TAB) or patch aortoplasty (PA). It is currently unclear what effect these interventions have on renal flow and pressure waveforms. This study, using retrospective data from a patient with SAAC subjected to a TAB, undertook computational modeling to analyze aortorenal blood flow preoperatively as well as postoperatively after a variety of TAB and PA interventions.

METHODS

Patient-specific anatomic models were constructed from preoperative computed tomography angiograms of a 9-year-old child with an isolated SAAC. Fluid-structure interaction (FSI) simulations of hemodynamics were performed to analyze preoperative renal flow and pressure waveforms. A parametric study was then performed to examine the hemodynamic impact of different bypass diameters and patch oversizing.

RESULTS

Preoperative FSI results documented diastole-dominated renal perfusion with considerable high-frequency disturbances in blood flow and pressure. The postoperative TAB right and left kidney volumes increased by 58% and 79%, respectively, reflecting the increased renal artery blood flows calculated by the FSI analysis. Postoperative increases in systolic flow accompanied decreases in high-frequency disturbances, aortic pressure, and collateral flow after all surgical interventions. In general, lesser degrees of high-frequency disturbances followed PA interventions. High-frequency disturbances were eliminated with the 0% PA in contrast to the 30% and 50% PA oversizing and TAB interventions, in which these flow disturbances remained.

CONCLUSIONS

Both TAB and PA dramatically improved renal artery flow and pressure waveforms, although disturbed renal waveforms remained in many of the surgical scenarios. Importantly, only the 0% PA oversizing scenario eliminated all high-frequency disturbances, resulting in nearly normal aortorenal blood flow. The study also establishes the relevance of patient-specific computational modeling in planning interventions for the midaortic syndrome.

Patient-specific 3D Printing: A Novel Technique for Complex Pediatric Renal Transplantation

OBJECTIVE

The authors investigated a novel application of patient-specific three-dimensional (3D) printing, to enhance preoperative, multidisciplinary planning in complex, living-donor pediatric renal transplantation.

SUMMARY BACKGROUND DATA

For children with end-stage kidney disease, the transplantation of adult-sized, living-donor kidneys into small recipients (<20 kg) with increasingly complex structural anomalies can be difficult. Establishing the operative feasibility in such cases demands a surgical understanding of anatomy to be derived from medical imaging. However, this is hampered by the representation of complex structures in 2D, the inherent interpretive expertise this demands, and the challenge of conveying this appreciation to others.

METHODS

We report the novel use of patient-specific 3D printed models to achieve personalized management for 3 children who underwent living-donor renal transplantation. Each presented a unique surgical challenge that would otherwise prevent preoperative determination of transplantation feasibility. Patient-specific geometries were segmented from imaging data and fabricated using polyjet, 3D printing technology. Models were verified by an expert radiologist and presented during multidisciplinary discussion and surgical simulation.

RESULTS

3D printed models enhanced preoperative deliberation and surgical simulation and allowed on-table exploration of a small child to be avoided. We have critically determined specific clinical indications, technical insights, limitations, and outcomes of this approach. At latest follow-up (>16 mo) all patients remain well with functioning renal allografts.

CONCLUSIONS

We report the new and safe integration of patient-specific 3D printing into complex pediatric renal transplantation. This technique enhances surgical planning and can inform operative feasibility in those cases which would otherwise be uncertain.

Doppler ultrasonographic and clinical features of middle aortic syndrome

OBJECTIVES

To discuss Doppler ultrasonographic and clinical features of middle aortic syndrome (MAS).

MATERIALS AND METHODS

Doppler ultrasonographic images and clinical dates of 11 patients with MAS confirmed by angiography were retrospectively analyzed from January 2004 to September 2016.

RESULTS

The median age of 11 patients was 10 years (1-39 years). Ten patients presented with hypertension, only 2 cases presented with symptomatic intermittent claudication, and 1 case presented with abdominal pain. The ultrasonographic features of 11 patients with MAS included: (a) Gray-scale image showed significant segmental narrowing of the aorta in 9 cases. (b) Color Doppler demonstrated aliasing in the suspicious narrowed vessels of all cases. (c) On Spectral Doppler image, peak systolic velocity in the location of aorta coarctation was significantly elevated (range, 2.3~4.8 m/s). When infrarenal aorta was involved, a tardus-parvus waveform was only seen in the distal aorta. When suprarenal or inter-renal aorta was involved, a tardus-parvus pattern was seen in the distal aorta as well as renal artery.

CONCLUSIONS

Significant segmental narrowing and a tardus-parvus waveform are the important ultrasonographic features in patients with MAS, the latter may be more reliable. Doppler ultrasound can be used as a simple screening method, especially for children and adolescents suspected of having a vascular cause of refractory hypertension.

The management of pediatric renovascular hypertension: a single center experience and review of the literature

INTRODUCTION

Renal artery occlusive disease is poorly characterized in children; treatments include medications, endovascular techniques, and surgery. We aimed to describe the course of renovascular hypertension (RVH), its treatments and outcomes.

METHODS

We performed literature review and retrospective review (1993-2014) of children with renovascular hypertension at our institution. Response to treatment was defined by National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents at most-recent follow-up.

RESULTS

We identified 39 patients with RVH. 54% (n=21) were male, with mean age of 6.93 ± 5.27 years. Most underwent endovascular treatment (n=17), with medication alone (n=12) and surgery (n=10) less commonly utilized. Endovascular treatment resulted in 18% cure, 65% improvement and 18% failure; surgery resulted in 30% cure, 50% improvement and 20% failure. Medication alone resulted in 0% cure, 75% improvement and 25% failure. 24% with endovascular treatment required secondary endovascular intervention; 18% required secondary surgery. 20% of patients who underwent initial surgery required reoperation for re-stenosis. Mean follow-up was 52.2 ± 58.4 months.

CONCLUSIONS

RVH treatment in children includes medications, surgical or endovascular approaches, with all resulting in combined 79% improvement in or cure rates. A multidisciplinary approach and individualized patient management are critical to optimize outcomes.

TYPE OF STUDY

Retrospective comparative study LEVEL OF EVIDENCE: Level III.

Management and Outcomes of Childhood Renal Artery Stenosis and Middle Aortic Syndrome

BACKGROUND

Renal artery stenosis (RAS) in isolation or in conjunction with middle aortic syndrome (MAS) are important vascular causes of childhood hypertension. Few longitudinal studies have assessed the risk of surgical or endovascular intervention, and outcomes by etiology or extent of vascular disease.

METHODS

In a retrospective study of 93 children seen over 30 years with RAS and/or MAS, data on vascular involvement (isolated RAS vs. RAS with MAS), etiology (unknown, inflammatory, or genetic), and management were collected. Time to first intervention (endovascular or surgical) was assessed by Cox regression. Mixed-effects analysis examined the longitudinal change in blood pressure after intervention compared to antihypertensive medications alone.

RESULTS

Children were 7.0 ± 5.4 years old. Etiology was unknown in 50%, genetic in 26% and inflammatory in 24% of children. Children had isolated RAS (49%) or MAS with or without RAS (51%). Overall, 70% were managed with surgical or endovascular intervention. After adjusting for age, sex, and systolic blood pressure, children with unknown etiology had a higher risk of intervention compared to those with genetic and inflammatory diseases (hazard ratio 3.1, 95% confidence interval [CI] 1.7, 5.6). Children with RAS and MAS were less likely to receive intervention (hazard ratio 0.4, 95% CI 0.2, 0.8) than isolated RAS. Over a median follow-up of 2 years, 65% remained hypertensive. The longitudinal changes in systolic blood pressure did not differ by etiology, or between interventional and medical management.

CONCLUSIONS

Hypertension persists despite endovascular or surgical management of childhood RAS and MAS highlighting the importance of close monitoring and ongoing medical management.

Arterial reconstructions for pediatric splanchnic artery occlusive disease

OBJECTIVE

Pediatric splanchnic arterial occlusive disease is uncommon and a rare cause of clinically relevant intestinal ischemia. This study was undertaken to better define the clinical manifestations and appropriate treatment of celiac artery (CA) and superior mesenteric artery (SMA) occlusive disease in children.

METHODS

Clinical courses of 30 consecutive children undergoing operations for splanchnic arterial occlusive disease at the University of Michigan from 1992 to 2017 were retrospectively analyzed.

RESULTS

Vascular reconstructions were performed for splanchnic arterial disease in 18 boys and 12 girls, 1.5 to 16 years of age (mean, 7.5 ± 4.1 years). Isolated splanchnic arterial disease was uncommon (2 children), being more often associated with abdominal aortic coarctations (19 children) or ostial renal artery stenoses (25 children). Primary splanchnic arterial reconstructions (30) included aortic reimplantation of SMAs (15) or celiacomesenteric arteries (2), aortoceliac and aortomesenteric bypasses (7), reimplantation of the CA as a patch over the stenotic SMA orifice (3), and patch angioplasty of the CA (2) or SMA (1). There was no perioperative mortality. Two groups (I and II) were identified for study. Group I children (14) experienced symptomatic intestinal ischemia, manifested by various combinations of chronic postprandial abdominal discomfort (14), ischemia-related intestinal bleeding (2), or failure to thrive (4). Four children in group I became symptomatic after known CA and SMA occlusive disease was left untreated at the time they underwent earlier interventions for renovascular hypertension. Seven secondary redo interventions were undertaken for recurrent symptoms in six group I children. Only one major periprocedural complication occurred: segmental colon infarction. The assisted patency rate of reconstructed arteries in group I children was 93%, and intestinal ischemic symptoms resolved in every child. Group I follow-up from the most recent splanchnic arterial reconstruction averaged 4.3 years. Group II children (16) without manifestations of intestinal ischemia underwent prophylactic splanchnic arterial reconstructions in concert with combined aortic and renal artery procedures (11), isolated abdominal aortic reconstructions (3), or renal artery reconstructions alone (2). Group II children experienced no major perioperative morbidity and remained asymptomatic postoperatively, and none required secondary splanchnic artery interventions. Group II follow-up averaged 7.4 years.

CONCLUSIONS

Pediatric splanchnic artery occlusive lesions are often associated with developmental aortic and renal artery occlusive disease. Carefully conducted therapeutic and prophylactic reconstructive procedures are appropriate in children having splanchnic arterial occlusive disease.

Long-Term Outcomes of Pediatric Renovascular Hypertension

BACKGROUND/AIMS

Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT.

METHODS

Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed.

RESULTS

Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), percentage of atrophic kidneys became higher after follow-up period in medication group than in PTA group (60.0% vs. 26.1%, P=0.037).

CONCLUSION

Aggressive treatment of pediatric RVHT yielded fair outcomes in our cohort. CVD comorbidity was associated with relatively poor PTA outcomes. To confirm our findings, larger cohort studies with a longer follow-up period are warranted.

Sonographic evaluation of renovascular hypertension in the pediatric population: State-of-the-art

Hypertension in children affects 2-5% of the pediatric population. Identifying secondary causes of hypertension is crucial, as some of these entities may be treatable. Renovascular hypertension accounts for 5-10% of the secondary causes of hypertension in children and is mainly related to fibromuscular dysplasia and neurofibromatosis type 1. Ultrasonographic evaluation of the kidneys, including Doppler interrogation, is the recommended primary screening tool. A comprehensive study of the upper abdomen and retroperitoneum allows for identification of additional underlying etiologies. The purpose of this review is to emphasize the different causes of renovascular hypertension in children one can diagnose during the initial ultrasonographic evaluation. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:282-292, 2017.

A rare cause of cardiomyopathy in an infant: middle aortic syndrome

Coarctation of the abdominal aorta is a rare condition with a handful of cases reported in infancy. We report the case of a 4-month-old infant with severe abdominal coarctation who presented with dilated cardiomyopathy. Following successful transcatheter-based stenting of her abdominal aorta, her cardiomyopathy resolved.

Idiopathic midaortic syndrome with malignant hypertension in 3-year-old boy

Midaortic syndrome (MAS) is a rare vascular disease that commonly causes renovascular hypertension. The lumen of the abdominal aorta narrows and the ostia of the branches show stenosis. MAS is associated with diminished pulses in the lower extremities compared with the upper extremities, severe hypertension with higher blood pressure in the upper rather than lower extremities, and an abdominal bruit. The clinical symptoms are variable, and recognition in children with hypertension can aid early diagnosis and optimal treatment. Hypertension with MAS is malignant and often refractory to several antihypertensive drugs. Recently, radiologic modalities have been developed and have led to numerous interventional procedures. We describe the case of a 3-year-old boy presenting with left ventricular hypertrophy whose severely elevated blood pressure led to the diagnosis of idiopathic MAS. This case highlights the importance of measuring blood pressure and conducting a detailed physical examination to diagnose MAS. This is the first reported case of idiopathic MAS diagnosed in childhood in Korea.

Infantile Renovascular Hypertension with Failure to Thrive

Severe hypertension in infancy is a rare cause of failure to thrive. The successful surgical management of this disease in an infant having refractory renovascular hypertension and growth failure is reported.

Middle aortic syndrome--an 8-year story of pills, pretty balloons and struts

BACKGROUND

Middle aortic syndrome (MAS) is an uncommon cause of hypertension in children. The management of hypertension secondary to MAS frequently requires several anti-hypertensive medications along with endovascular and often surgical intervention.

CASE-DIAGNOSIS/TREATMENT

A 9-year-old boy presented with headaches and vomiting and was diagnosed with severe hypertension secondary to idiopathic MAS affecting a long segment of the abdominal aorta and left renal artery stenosis. Over the following 8 years his hypertension was successfully managed initially with percutaneous transluminal balloon angioplasty (PTA) of his left renal artery, followed by balloon dilatation of his abdominal aortic narrowing. He subsequently underwent abdominal aortic stent placement following failed repeat aortic balloon dilatation. Aged 17 years and 6 months he is now on a single anti-hypertensive agent with normal renal function and no evidence of target organ damage.

CONCLUSION

In selected cases, MAS may be managed with PTA and stent placement with good long-term outcomes. Limited data on the use of PTA and stent insertion in children means that a structured approach to the management of refractory hypertension secondary to MAS remains elusive.

Angioplasty for pediatric renovascular hypertension: a 13-year experience

PURPOSE

We aimed to evaluate the long-term outcome and efficacy of percutaneous transluminal renal angioplasty (PTRA) for pediatric renal artery stenosis (RAS), which is an important cause of medication-refractory pediatric hypertension.

MATERIALS AND METHODS

We retrospectively evaluated 22 hypertensive children (age range, 3-17 years) who underwent PTRA from February 2000 to July 2012. Sixteen patients had Takayasu arteritis and six fibromuscular dysplasia. Five were not included in the statistical analysis due to loss to follow-up.

RESULTS

Technical success was achieved in 32 of 34 procedures (94.1%). The stenosis rate decreased from 84.5% before PTRA to 20.1% after PTRA. Treatment was effective in 72.7% (16/22) of patients, including complete cure in 27.3% (6/22) and improvement in 45.5% (10/22). Systolic and diastolic blood pressures decreased from 153 ± 19.1 to 131.7 ± 21.4 mmHg and from 97.9 ± 14.2 to 83.6 ± 19.3 mmHg, respectively (P <0.01). Number of antihypertensive agents decreased from 2.7 to 0.5 per patient. Restenosis was detected in 40.9% (9/22) of patients, with a restenotic interval of 11.8 months (range, 3-47 months). Lesion length was strongly correlated with clinical success (cure and improvement) (independent-sample t test, P <0.001; binary logistic regression, P = 0.040).

CONCLUSION

Lesion length is an important determination of clinical success with PTRA for pediatric RAS. PTRA is an appropriate treatment option for pediatric renovascular hypertension due to Takayasu arteritis and fibromuscular dysplasia.

Disease Beyond the Arch: A Systematic Review of Middle Aortic Syndrome in Childhood

BACKGROUND

Middle aortic syndrome (MAS) is a rare clinical entity in childhood, characterized by a severe narrowing of the distal thoracic and/or abdominal aorta, and associated with significant morbidity and mortality. MAS remains a relatively poorly defined disease. This paper systematically reviews the current knowledge on MAS with respect to etiology, clinical impact, and therapeutic options.

METHODS

A systematic search of 3 databases (Embase, MEDLINE, and Cochrane Central Register of Controlled Trials) yielded 1,252 abstracts that were screened based on eligibility criteria resulting in 184 full-text articles with 630 reported cases of childhood MAS. Data extracted included patient characteristics, clinical presentation, vascular phenotype, management, and outcomes.

RESULTS

Most cases of MAS are idiopathic (64%), 15% are associated with Mendelian disorders, and 17% are related to inflammatory diseases. Extra-aortic involvement including renal (70%), superior mesenteric (30%), and celiac (22%) arteries is common, especially among those with associated Mendelian disorders. Inferior mesenteric artery involvement is almost never reported. The majority of cases (72%) undergo endovascular or surgical management with residual hypertension reported in 34% of cases, requiring medication or reintervention. Clinical manifestations and extent of extra-aortic involvement are lacking.

CONCLUSIONS

MAS presents with significant involvement of visceral arteries with over two thirds of cases having renal artery stenosis, and one third with superior mesenteric artery stenosis. The extent of disease is worse among those with genetic and inflammatory conditions. Further studies are needed to better understand etiology, long-term effectiveness of treatment, and to determine the optimal management of this potentially devastating condition.