Early and Long-term Results after Reconstructive Surgery in 42 Children and Two Young Adults with Renovascular Hypertension due to Fibromuscular Dysplasia and Middle Aortic Syndrome

Myhre syndrome: expanding its paediatric phenotypic spectrum

Myhre syndrome is a rare disease secondary to pathogenic variants in SMAD4 gene. It is a multisystem disease characterised by short stature, deafness, joint stiffness, craniofacial dysmorphism, and potential cardiac manifestations. Herein, we report two new paediatric cases of Myhre syndrome who, additionally, presented with mid-aortic syndrome. This confirms and extends the scarce reports describing the association between these two entities.

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.

Hypertension crisis as the first symptom of renovascular hypertension in children

BACKGROUND

Renovascular hypertension (RVH) is one of the main causes of hypertensive crisis (HTN-C). It is characterized by acute onset and severe disease, and early diagnosis and treatment are difficult. The objective was to describe the characteristics of RVH and factors associated with RVH leading to HTN-C in children. At present, there are few clinical studies on RVH in children with large cases in China.

METHODS

This study retrospectively analyzed the clinical data of inpatient children with RVH. Patients were divided into non-hypertensive crisis (non-HTN-C) group, and HTN-C group according to the first symptoms and blood pressure. Further, HTN-C were classified as hypertensive urgency (HTN-U) or hypertensive emergency (HTN-E).

RESULTS

Fifty-four pediatric cases (41 boys and 13 girls) were included. 83.3% of the RVH cases were ≥ 6 years old. Three cases were classified into the non-HTN-C group. Of the 51 HTN-C cases, 18 cases were grouped as HTN-U and 33 as HTN-E. The HTN-U group were mainly asymptomatic (50.0%, 9/18) while the HTN-E group mainly presented with neurological symptoms (72.7%, 24/33). The number of unknown etiology children was 32 (59.2%). The top three known etiologies were Takayasu's arteritis (50.0%, 11/22), congenital renal dysplasia (27.3%, 6/22) and fibromuscular dysplasia (13.6%, 3/22). As for the target organ damage of RVH, patients had a higher prevalence of left ventricular hypertrophy (71.4%, 35/49) and retinopathy (77.8%, 21/27).

CONCLUSIONS

Most RVH patients with HTN-C as the first symptoms, especially for males over 6 years old, should be assessed for RVH even if they were asymptomatic. Most asymptomatic patients with RVH already had target organ damage, and symptomatic patients even developed life-threatening complications. As preventive measures, routine monitoring of BP during children's physical examinations is advised.

Presentation, treatment, and outcome of renovascular hypertension below 2 years of age

Renovascular hypertension in most cases requires endovascular treatment and/or surgery. This is technically much more difficult in small children and there is very limited published knowledge in this age group. We here present treatment and outcome of young children with renovascular hypertension at our institution. Children below 2 years of age, with renovascular hypertension between January 1998 and March 2020 were retrospectively reviewed. Demographics and treatment modalities were noted. Primary outcome was blood pressure within a week after the procedures and at last available visit. Sixty-six angiographies were performed in 34 patients. Median age at time of first angiography was 1.03 (interquartile range (IQR) 0.4-1.4) years and systolic blood pressure at presentation 130 (IQR 130-150) mm Hg. Thirty-eight percent (13/34) of children were incidentally diagnosed and 18% (6/34) presented with heart failure. Twenty-six (76%) children had main renal artery stenosis and 17 (50%) mid-aortic syndrome. Seventeen (50%) children showed intrarenal, six (18%) mesenteric, and three (9%) cerebrovascular involvement. Twenty patients underwent 45 percutaneous transluminal angioplasty procedures and seven children surgeries. In 44% of the 16 patients who underwent only percutaneous transluminal angioplasty blood pressure was normalized, 38% had improvement on same or decreased treatment and 19% showed no improvement. Complications were seen in 7.5% (5/66) of angiographies. In four of the seven (57%) children who underwent surgery blood pressure was normalized, two had improved (29%) and one unchanged (14%) blood pressure.

CONCLUSION

In small children with renovascular hypertension below the age of 2 years, percutaneous transluminal angioplasty caused significant improvement in blood pressure with low complication profile. Surgery can be recommended where percutaneous transluminal angioplasty and medical treatments failed.

WHAT IS KNOWN

• Renovascular hypertension is diagnosed in all age groups from a few weeks of life until adulthood. • Both angioplasty and surgery are significantly more difficult to perform in small children and the published information on short and long-term outcome in these children is very scarce.

WHAT IS NEW

• Children below the age of two years can safely and successfully undergo selective renal angiography and also safely be treated with angioplasty. • We here present a large group of babies and infants where angioplasty and in some cases surgery effectively and safely improved their blood pressure.

Coarctação de aorta abdominal justarrenal associada à hipertensão renovascular e claudicação incapacitante: tratamento utilizando ponte ilíaco-birrenal e técnica “paving and cracking”

Resumo Coarctação da aorta abdominal é uma causa rara de claudicação de membros inferiores e hipertensão refratária. O tratamento é complexo e exige conhecimento de diversas técnicas de reconstrução vascular. Apresentamos um caso de coarctação ao nível das artérias renais, seu tratamento e revisão da literatura. Paciente feminina, 65 anos, com hipertensão refratária desde os 35 anos, utilizando cinco medicações anti-hipertensivas em dose máxima. Pressão arterial média de 260/180mmHg e claudicação incapacitante (menos de 20 metros) bilateral. Angiotomografia computadorizada demonstrou coarctação de aorta justarrenal de 4 mm de maior diâmetro, calcificação circunferencial no local da estenose e tortuosidade da aorta infrarrenal. Foi submetida a tratamento híbrido, com ponte ilíaco-birrenal e implante de stent Advanta V12 no local da estenose. A paciente evoluiu satisfatoriamente e, 60 dias depois da cirurgia, apresentava-se com uma pressão arterial de 140/80mmHg, em uso de apenas duas medicações anti-hipertensivas e sem claudicação.

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.

Complex Multi-Stage Total Aortic and Subclavian Artery Replacement in a 9-year old boy with Loeys-Dietz-Syndrome

BACKGROUND

Loeys-Dietz Syndrome is a rare connective tissue disorder that is associated with arterial pathologies such as aortic dissections, tortuosity and aneurysms.We present a child with Loeys-Dietz Syndrome type 2 that received total aortic and bilateral subclavian artery replacement.

CASE REPORT

A 9-year old boy with Loeys-Dietz Syndrome type 2 and acute type B aortic dissection received an urgent complete thoracic and thoraco-abdominal aortic repair within three days. First, the ascending aorta and aortic root were replaced in a Tirone David and Frozen Elephant Trunk procedure. Then, the descending and supramesenteric aorta was replaced by a Dacron interposition graft with direct implantation of the celiac trunk. During the 15 months follow-up, the patient required three more surgical interventions for rapid expanding aneurysms of both subclavian arteries and the infrarenal aorta. No major adverse event nor secondary interventions occurred. Ultrasonographic and magnetic resonance imaging follow-up is continued at 6-months intervals.

CONCLUSION

Children with Loeys-Dietz Syndrome may require extensive aortic repair for aortic dissection and show rapidly expanding aneurysms. Referral to a center with pediatric vascular expertise and long-term follow-up examinations are crucial.

Surgical treatment of abdominal compression syndromes: The significance of hypermobility-related disorders

Case reports and systematic studies of the most common hypermobility-related disorders, hypermobile Ehlers-Danlos syndrome (hEDS), and hypermobility spectrum disorder (HSD) typically describe gastroenterological symptoms and complaints attributed to structural malfunction, autonomic dysfunction, or inflammation of the gastrointestinal tract. However, abdominal compression syndromes (CS) may also contribute to pain and dysfunction in these individuals and be the leading pathology given symptoms significantly reduce or cease after decompressive surgery. Arising not only in the abdomen and causing pain (median arcuate ligament syndrome [MALS] and superior mesenteric artery syndrome [SMAS]), CS also occur in the retroperitoneum and the pelvis (nutcracker syndrome and May-Thurner syndrome), these latter conditions causing chronic pelvic congestion syndrome (PCS). Here, we report primarily on our experience of the assessment and management of MALS and SMAS in a cohort of cases with a surprising prevalence of HSD and hEDS. To our knowledge, this is the first cohort report of its kind in hEDS, HSD, and CS. We recommend that CS are considered in hEDS and HSD individuals with gastrointestinal and other painful complaints within the "belt" area. These CS can be identified using functional ultrasound duplex examination in experienced hands, and in appropriate cases stabilizing surgery can substantially improve quality of life.

Timing of procedural interventions in childhood renovascular hypertension

BACKGROUND

Renovascular hypertension (RVHTN) is a rare, often complex condition due to multiple etiologies including congenital stenoses, vasculitides, and fibromuscular dysplasia. Among children with RVHTN who require multiple and escalating medications to control blood pressure, the optimal timing of a procedural intervention involves a balance of numerous factors.

CASE-DIAGNOSIS/TREATMENT

In this presentation of a 1-month-old girl with RVHTN, the treating medical team had to consider multiple factors in the initial management and timing of interventions to treat her underlying cause of RVHTN, including concerns for kidney health, degree of hypertension, age and size of the patient, and potential methods of procedural intervention. Initially, she was treated conservatively until concern for poor renal growth arose and a durable surgical intervention was thought feasible and safe.

CONCLUSION

The evidence regarding the timing of non-medical interventions in pediatric RVHTN is limited. Considerations should include patient age, size, disease severity, comorbid conditions, and degree of medical management required to maintain safe blood pressures that allow for growth and reverse cardiac damage. The optimal interventions have not been evaluated by controlled trials and should be decided on a case-by-case basis with consideration of center expertise and family preferences.

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.

Arterial Stiffness in a Toddler with Neurofibromatosis Type 1 and Refractory Hypertension

Arterial hypertension is a common finding in patients with neurofibromatosis (NF) type 1. Renovascular hypertension due to renal artery stenosis or midaortic syndrome could be the underlying cause. We report the case of a 4-year-old girl with NF type 1 and midaortic syndrome whose changes in blood pressure and pulse wave velocity suggested the evolution of vasculopathy, diagnosis of renovascular hypertension, and provided insights of response to treatment. Hypertension persisted after percutaneous transluminal angioplasty in the abdominal aorta, requiring escalation of antihypertensive treatment, while arterial stiffness demonstrated a mild decrease. Regular assessment of blood pressure using ambulatory blood pressure monitoring and noninvasive assessment of arterial stiffness may enhance the medical care of patients with NF type 1.

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.

Cutting Balloon Angioplasty (CBA) for the Treatment of Renal Artery Fibromuscular Dysplasia (FMD) in Six Patients: 5-Year Long-Term Results

PURPOSE

To evaluate long-term outcomes in terms of hypertension control, recurrent stenosis, and reinterventions from patients who underwent cutting balloon angioplasty (CBA) for symptomatic renal artery fibromuscular dysplasia (FMD).

MATERIALS AND METHODS

From 2011, six consecutive renal artery FMD women underwent CBA for poorly controlled hypertension, despite antihypertensive therapy. Follow-up consisted of blood pressure monitoring and duplex ultrasonography at 1, 6, and 12 months and thereafter annually for 5 years.

RESULTS

All treatments were technically successful. Recurrence of hypertension was found in two patients within 12 months, and reinterventions were performed using CBA.

CONCLUSION

Results show the efficacy of CBA for renal artery FMD.

Open Repair for Abdominal Aortic Aneurysm in a Young Boy with Tuberous Sclerosis and Review of the Literature

BACKGROUND

Abdominal aortic aneurysms (AAAs) are very rare in pediatric patients and can rarely be associated with tuberous sclerosis (TS). Open surgery is the first-line therapy. We report our experience added by a review on current literature.

CASE REPORT

A 9-year-old boy with TS and history of 2 earlier open repairs for AAA presented to our department with a recurrent juxtarenal aortic aneurysm. We performed a polytetraflourethylene patch plasty. Postoperative course was uneventful. After 8 months, reconstruction was stable, and no recurrent aneurysm developed.

CONCLUSIONS

Recurrent aneurysms may develop after open surgery for TS-associated AAA. However, open surgery is the recommended therapy but requires special techniques and experience in pediatric patients.

Remedial operations for failed endovascular therapy of 32 renal artery stenoses in 24 children

BACKGROUND

Percutaneous transluminal angioplasty (PTA) for the treatment of pediatric renovascular hypertension (RVH) in contemporary practice is accompanied with ill-defined complications. This study examines the mode of pediatric renal PTA failures and the results of their surgical management.

METHODS

Twenty-four children underwent remedial operations at the University of Michigan from 1996 to 2014 for failures of renal PTA. Their clinical courses were retrospectively reviewed and results analyzed.

RESULTS

Renal PTA of 32 arteries, including 13 with stenting, was performed for severe RVH in 12 boys and 12 girls, having a mean age of 9.3 years. Developmental ostial stenoses affected 22 children. PTA failures included: 27 restenoses and five thromboses. Remedial operations included: 13 renal artery-aortic reimplantations, one segmental renal artery-main renal artery reimplantation, ten aortorenal bypasses, one arterioplasty, one iliorenal bypass, and six nephrectomies for unreconstructable arteries; the latter all in children younger than 10 years. Follow-up averaged 2.1 years. Postoperatively, hypertension was cured, improved, or unchanged in 25, 54, and 21 %, respectively. There was no perioperative renal failure or mortality.

CONCLUSIONS

Renal PTA for the treatment of pediatric RVH due to ostial disease may be complicated by failures requiring complex remedial operations or nephrectomy, the latter usually affecting younger children.

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.