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

Severe hypertension in tuberous sclerosis complex caused by renal artery stenosis: A case report

Tuberous sclerosis complex (TSC) is a rare autosomal dominant neurocutaneous disease. Arterial hypertension is one of its uncommon complications, which is supposed to be caused by renal cysts or angiomyolipomas. Few studies have been reported in the literature on renal artery stenosis (RAS) as the cause of hypertension in TSC. Hence, we reported a boy who presented with uncontrolled hypertension under five anti-hypertension drugs and was diagnosed with TSC complicated with left RAS. His high blood pressure was relieved by percutaneous transluminal renal angioplasty (PTRA). In one and a half years follow-up, his blood pressure was normal whilst he took four anti-hypertensive drugs. In conclusion, children with TCS complicated with hypertension should be carefully screened for RAS, which might be relieved by percutaneous balloon dilatation.

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.

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.

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.

Clinical Scenario and Long-Term Outcome of Childhood Takayasu Arteritis Undergoing 121 Endovascular Interventions: A Large Cohort Over a Fifteen-Year Period

OBJECTIVE

Evidence-based studies on endovascular approaches for childhood Takayasu arteritis (TAK) are limited. Our objective was to present the largest current real-world scenario for patients with childhood TAK undergoing interventions and their postinterventional outcomes.

METHODS

Data were collected for patients with childhood TAK admitted from 2002 to 2017. Complication/reintervention-free survival was projected by Kaplan-Meier methods. Associated factors for intervention and predictors for postinterventional complications/reinterventions were assessed via regression models.

RESULTS

Among 101 patients enrolled, 69 (68.3%) underwent 121 interventions (angioplasty 95, stenting 26) during a 3.1-year follow-up. Compared with the nonintervention group, the intervention group independently associated with a male population (odds ratio [OR] 0.27, P = 0.035) and type IV disease (OR 17.92, P = 0.001). Male sex also marginally indicated a risk for reintervention (hazard ratio [HR] 3.22, P = 0.05). Baseline retinopathy, delay in diagnosis, and descending thoracic aorta involvement were associated with stent insertion (P < 0.05). Hypertension secondary to renal artery stenosis (RAS; 59.4%) or mid-aorta stenosis (MAS; 14.5%), heart failure (21.7%), and claudication (21.7%) were leading clinical hints for interventions. The technical success rate was 96.7%. During a median 2.88-year of follow-up after intervention, 36 lesions occurred with complications in 28 patients, and 22 lesions in 17 patients, particularly on the renal artery or mid-aorta. The 5-year complication-free and reintervention-free survivals were 50.7% and 65.8%, respectively. Peri-interventional dual antiplatelet therapy (DAPT; HR 0.31), concurrent surgery (HR 26.5), and technical failure (HR 3.65) were independent predictors for complications (P < 0.05). Male sex (HR 2.52), retinopathy secondary to hypertension (HR 3.41), and pulmonary artery hypertension (PAH; HR 3.64) were baseline indicators for complications (P < 0.05).

CONCLUSION

Over two-thirds of patients with childhood TAK require interventions, and the 5-year complication-free survival is 50.7%. Male sex, retinopathy, and PAH at baseline indicate the possibility of unfavorable outcomes. Interventions on MAS or RAS in childhood TAK raise specific concerns. DAPT peri-intervention appears to protect patients with childhood TAK from postinterventional complications.

Surgical management of pediatric renin-mediated hypertension secondary to renal artery occlusive disease and abdominal aortic coarctation

BACKGROUND

Renovascular hypertension (RVH) associated with renal artery and abdominal aortic narrowings is the third most common cause of pediatric hypertension. Untreated children may experience major cardiopulmonary complications, stroke, renal failure, and death. The impetus of this study was to describe the increasingly complex surgical practice for such patients with an emphasis on anatomic phenotype and contemporary outcomes after surgical management as a means of identifying those factors responsible for persistent or recurrent hypertension necessitating reoperation.

METHODS

A retrospective analysis was performed of consecutive pediatric patients with RVH undergoing open surgical procedures at the University of Michigan from 1991 to 2017. Anatomic phenotype and patient risk factors were analyzed to predict outcomes of blood pressure control and the need for secondary operations using ordered and binomial logistic multinomial regression models, respectively.

RESULTS

There were 169 children (76 girls, 93 boys) who underwent primary index operations at a median age of 8.3 years; 31 children (18%) had neurofibromatosis type 1, 76 (45%) had abdominal aortic coarctations, and 28 (17%) had a single functioning kidney. Before treatment at the University of Michigan, 51 children experienced failed previous open operations (15) or endovascular interventions (36) for RVH at other institutions. Primary surgical interventions (342) included main renal artery (136) and segmental renal artery (10) aortic reimplantation, renal artery bypass (55), segmental renal artery embolization (10), renal artery patch angioplasty (8), resection with reanastomosis (4), and partial or total nephrectomy (25). Non-renal artery procedures included patch aortoplasty (32), aortoaortic bypass (32), and splanchnic arterial revascularization (30). Nine patients required reoperation in the early postoperative period. During a mean follow-up of 49 months, secondary interventions were required in 35 children (21%), including both open surgical (37) and endovascular (14) interventions. Remedial intervention to preserve primary renal artery patency or a nephrectomy if such was impossible was required in 22 children (13%). The remaining secondary procedures were performed to treat previously untreated disease that became clinically evident during follow-up. Age at operation and abdominal aortic coarctation were independent predictors for reoperation. The overall experience revealed hypertension to be cured in 74 children (44%), improved in 78 (46%), and unchanged in 17 (10%). Children undergoing remedial operations were less likely (33%) to be cured of hypertension. There was no perioperative death or renal insufficiency requiring dialysis after either primary or secondary interventions.

CONCLUSIONS

Contemporary surgical treatment of pediatric RVH provides a sustainable overall benefit to 90% of children. Interventions in the very young (<3 years) and concurrent abdominal aortic coarctation increase the likelihood of reoperation. Patients undergoing remedial surgery after earlier operative failures are less likely to be cured of hypertension. Judicious postoperative surveillance is imperative in children surgically treated for RVH.

Clinical Course, Management, and Outcomes of Pediatric Takayasu Arteritis Initially Presenting With Hypertension: A 16-year overview

BACKGROUND

To investigate the clinical features, management, and outcomes of childhood Takayasu arteritis (c-TA) initially presenting with hypertension.

METHODS

This study retrospectively reviewed medical charts of 96 inpatient c-TA cases from January 2002 to December 2016, with 5 additional patients being prospectively recruited from January 2017 to December 2017. Data were compared between c-TA groups initially presenting with and without hypertension. Blood pressure (BP) control, event-free survival, and associated risk factors were assessed by logistic regression, Kaplan-Meier survival curve, and COX regression models.

RESULTS

The hypertensive cohort (N = 71, 28.2% males) as compared with non-hypertensive cohort had significantly fewer active diseases; fewer episodes of claudication, syncope, blurred vision, and myocardial ischemia; and fewer systemic symptoms (P < 0.05). The hypertensive group presented with more localized abdominal lesions (OR = 14.4, P = 0.001) and limited supradiaphragmatic arterial involvement. Renovascular disease (P = 0.001) and revascularization (P = 0.006) were associated with hypertension. At the median 3-year follow-up, 53% of hypertensive patients achieved BP control and 39% experienced events including vascular complications, flares, or death. The 1-, 3-, 5-, and 10-year event-free survival were 78.7% (95% CI: 65.7%-87.2%), 63.0% (95% CI: 48.1%-74.7%), 48.9% (95% CI: 32.0%-63.8%), and 31.6% (95% CI: 13.8%-51.2%), higher than in non-hypertensive group (P = 0.014). Heart failure, stroke, and body mass index <18.5 kg/m2 were prognostic factors for events. Intervention and baseline systolic BP were independent factors for BP control (P < 0.05).

CONCLUSIONS

Majority of c-TA has hypertension, presenting with a more quiescent disease without typical systemic and/or ischemia symptoms, more localized abdominal lesions, higher proportion of revascularizations and better event-free survival. Three-year BP control is more than 50%. Intervention particularly on renal artery is beneficial for BP control and decreased events.

CLINICAL TRIAL REGISTRATION

Trial Number: NCT03199183.

Clinical course and prognostic factors of childhood Takayasu's arteritis: over 15-year comprehensive analysis of 101 patients

BACKGROUND

Childhood Takayasu's arteritis (c-TA) is scarcely reported but is characterized by devastating morbidity and mortality. This study aims to investigate the clinical course of c-TA and prognostic factors associated with rehospitalization and events including vascular complications, flares, and death.

METHODS

An ambispective study of 101 c-TA patients satisfying the American College of Rheumatology (ACR) criteria and/or the European League against Rheumatism (EULAR)/Pediatric Rheumatology International Trials Organization (PRINTO)/Pediatric Rheumatology European Society (PReS) criteria was conducted from January 2002 to December 2017. Data on demographic, clinical, laboratory, imaging, and therapeutic features were collected. Event-free survival, complication-free survival, flare-free survival, rehospitalization-free survival, and associated prognostic factors were assessed by Kaplan-Meier survival curve and propensity score analysis.

RESULTS

The median age at c-TA onset was 14 (interquartile range (IQR) 12-16) years and 76.2% were female. Hypertension (70.3%), blood pressure discrepancy (55.4%), bruits (51.5%), and pulse deficits (37.6%) were core presentations. Major vascular involvement included the renal artery (62.4%), abdominal aorta (42.6%), subclavian artery (43.6%), and carotid artery (42.6%). Glucocorticoids (78.2%), antihypertensive drugs (72.3%), antiplatelet agents (72.3%), and revascularization (57.4%) were made up the majority administered. At a median 2.4 (IQR 0.7-6.1) years of follow-up, events, rehospitalization, vascular complications, flares and death were observed in 44.6%, 37.6%, 44.6%, 26.7%, and 3%, respectively. The 5-year event-free survival, rehospitalization-free survival, vascular complication-free survival, and flare-free survival were 42.8%, 55.8%, 45.9%, and 62.3%, respectively. Body mass index (BMI) (hazard ratio (HR) = 0.49, 95% confidence interval (CI) 0.30-0.81, p = 0.005), stroke (HR = 7.37, 95% CI 2.35-23.1, p = 0.001), and revascularization (HR = 0.51, 95% CI 0.27-0.94, p = 0.032) were independent prognostic predictors of events. Predictors for rehospitalization include age at admission (HR = 0.81, 95% CI 0.69-0.94, p = 0.006), renal artery involvement (HR = 0.49, 95% CI 0.25-0.96, p = 0.037), and elevated C-reactive protein (CRP; HR = 2.50, 95% CI 1.24-5.00, p = 0.01). BMI level (p = 0.024) and renal artery involvement (p = 0.015) were also associated with vascular complications, while revascularization (p = 0.002) independently correlated with re-flares.

CONCLUSIONS

This large ambispective study of c-TA revealed an early 3% mortality at the first year and around 50% morbidity within 5 years after diagnosis. Hypertension, renal artery involvement, and revascularization based on anti-inflammation, antihypertension, and antiplatelet medications dominated c-TA with indications for optimistic prognosis. Patients with initial lower BMI level, a younger age at admission, stroke, and elevated CRP have a high risk of poor outcomes, requiring close c-TA monitoring and more aggressive management.

TRIAL REGISTRATION

NCT03199183 , unique protocol ID: 2016-ZX43. June 26, 2017.

Pediatric Vascular Surgical Practice Patterns

BACKGROUND

Vascular surgeons infrequently care for pediatric patients. As such, variability in operative management and available hospital resources at free-standing children's hospitals (CHs) may exist. The study aims were (1) to determine vascular surgeon comfort level with pediatric vascular surgery and (2) to determine variations in pediatric vascular surgery practice patterns.

METHODS

A survey composed of clinical vignettes emailed to all members of Vascular and Endovascular Surgery Society was designed to assess operative management of pediatric vascular conditions and hospital resources. Comparisons of surgeon satisfaction between free-standing CHs and a CH within an adult general hospital were made using Wilcoxon rank-sum tests. Comparison of surgeon comfort between hospital types was made using a McNemar's test. P-values less than or equal to 0.05 indicated statistical significance.

RESULTS

Response rate was 18% (93/525) with 96% (89/93) indicating completion of a 2 year vascular fellowship. Surgeon satisfaction with operative equipment (P = 0.002), support staff (P < 0.001), and vascular laboratory availability (P = 0.01) was significantly lower at CHs. Eighty-seven percent of surgeons operated on fewer than 2 children over the preceding 3 months. For the different clinical vignettes, there was a wide variation in practice patterns with a range of 50-89% of the surgeons performing fewer than 5 cases over the preceding 10 years. There was a significant decrease in surgeon's comfort level with elective pediatric vascular operations compared to the operative management of pediatric vascular trauma (P = 0.0025).

CONCLUSIONS

Most vascular surgeons do not feel comfortable in the operative management of pediatric vascular disease, and optimal resource availability within pediatric CHs may be lacking. Centralized care of this patient population may be warranted.