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

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.

A Unique Case of Middle Aorta Syndrome With a "Corkscrew" Descending Aorta

Middle aortic syndrome is a rare anatomic defect of the descending aorta and presents with hypertension. We present a unique case with "corkscrew" configuration. This case highlights the need for evaluation with advanced imaging for diagnosis to facilitate surgical management and avoid hypertensive complications.

Endovascular Management of Neurofibromatosis Type I-Associated Vasculopathy: A Case Series and Brief Review of the Literature

Purpose:

Neurofibromatosis type 1 (NF1) is an autosomal-dominant disorder found in approximately 1 of every 3000 individuals. Neurofibromatosis type 1 can have vascular manifestations including aneurysms, stenoses, and arteriovenous malformations. The purpose of this article is to describe the clinical manifestations of NF1 vasculopathy, discuss therapeutic options, and highlight endovascular therapies from our institutional experience.

Materials and Methods:

The radiology information system was searched for cases of NF1. Cases with vasculopathy managed with endovascular therapies were included. Demographics, clinical histories, procedural details, and outcomes were recorded. A review of the literature for the management strategies of NF1 vasculopathy was performed.

Results:

Two pediatric patients with NF1 were identified, both of whom presented with hypertension found to be secondary to renal artery stenosis. One of the patients also had infrarenal aortic narrowing. Both patients were successfully treated with balloon angioplasty, resulting in improved blood pressures. The review of the literature identified case series of pharmacologic, surgical, and endovascular therapies, although, endovascular therapies appear to be preferred due to lower morbidity and mortality.

Conclusions:

NF1 vasculopathy is a rare condition that most often presents with hypertension due to renal artery stenosis. In these situations, endovascular management is the preferred approach.

Midaortic Syndrome due to Takayasu Arteritis in a Child with Acute Decompensated Cardiac Failure Managed by an Emergency Axillo-External Iliac Artery Bypass: A Follow-Up Case Report of Long-Term Outcomes

Midaortic syndrome (MAS) is characterized by a diffuse narrowing of the distal thoracic or abdominal aorta and is concomitant with various etiologies. The common symptoms of MAS include severe hypertension or arterial insufficiency distal to the stenosis. This includes lower extremity claudication and heart failure due to afterload mismatch. We present the case of an 8-year-old girl who developed acute decompensated cardiac, respiratory, and renal failures because of the occlusion of the descending aorta secondary to Takayasu arteritis (TA). Although thoracoabdominal-aortic bypass is usually performed for patients with MAS, the procedure was considered too invasive, given the patient's condition. Therefore, we performed an emergency axillo-external iliac artery bypass for revascularization. Subsequently, organ failure improved and she was discharged. At postoperative 10 years, an asymptomatic pseudoaneurysm was detected at the distal anastomosis, for which revision surgery was performed. Overall, the long-term prognosis was satisfactory, suggesting that this procedure is less invasive and effective for treatment of MAS due to TA, in emergencies.

The Superior Mesenteric Artery: From Syndrome in the Young to Vascular Atherosclerosis in the Old

This review is directed at increasing awareness of two diverse rare upper gastrointestinal problems that occur at opposite ends of the age spectrum and are difficult to diagnose and treat. The Superior Mesenteric Artery Syndrome (SMAS) likely involves a young patient, especially female, and is especially associated with rapid weight loss, resulting in relative strangulation of the duodenum by a narrowing of the angle between the Superior Mesenteric Artery (SMA) and the aorta. On the other hand, atherosclerosis of the SMA is associated most likely with postprandial upper intestinal ischemia and abdominal pain occurs in the elderly at high risk for cardiovascular (CV) disease. Medical management of the SMAS in the young involves good alimentation and weight gain to overall increase the intestinal fat pad. Medical management of SMA atherosclerotic ischemia in the elderly is directed at marked lipid lowering with atherosclerotic plaque stabilization or even regression. If needed, surgery for SMAS can be attempted laparoscopically with duodenojejunoscopy which is the most popular procedure but there are also more conservative possibilities that avoid division of the duodenum. In addition, sometimes direct vision is needed to successfully operate on SMAS. If surgery is needed for SMA atherosclerotic ischemia, it is usually attempted endoscopically with angioplasty and stent placement. Most important, in the case of these two rare clinical entities, is that the clinician have a suspicion of their presence when indicated so that the young or old patient can be spared unnecessary suffering and return to good health in a timely fashion.

Severe midaortic syndrome: a stepwise approach to treatment with drug-eluting balloons: a case report

Background

Severe forms of the midaortic syndrome cause persistent arterial hypertension and can lead to angina abdominalis. Untreated, morbidity, and mortality are significant. In addition to palliation through bypass surgery, few other therapeutic approaches lead to a long-term relief. Drug-eluting balloons (DEB) covered with paclitaxel, a cytostatic drug, have proven to be effective in bifurcational lesions and for in-stent stenoses in coronary arteries.

Case summary

In a 15-year-old girl with severe midaortic syndrome and multiple collateral arteries, four interventional balloon dilatations with DEB of increasing diameters resolved the stenosis within 8 months. After a procedure free interval of now 2.7 years, the anatomical and the physical condition of the patient remained unchanged.

Discussion

This stepwise approach, with a low procedural risk and a lasting result may justify further investigations into this combined treatment.

Progesterone receptor expression in fibromuscular dysplasia: A report of two unusual cases

Fibromuscular dysplasia is rarely biopsied. Progesterone receptor expression in myofibroblastic cells is useful for the histopathological evaluation in difficult-to-diagnose cases. Herein, we report two unusual cases of fibromuscular dysplasia in which progesterone receptor expression was shown in vessel sections.

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.

Cardiovascular Structure and Function in Children With Middle Aortic Syndrome and Renal Artery Stenosis

Middle aortic syndrome (MAS) is a narrowing of the abdominal aorta, often in conjunction with renal artery stenosis (RAS). Structure and function of the cardiovascular system are not well understood. In a prospective cross-sectional study, 35 children with MAS or RAS or both (MAS/RAS) were compared with 140 age-, sex-, and body surface area–matched healthy children. Vascular assessment included carotid intima–media thickness and carotid distensibility using B-mode ultrasound and central and peripheral pulse wave velocities using applanation tonometry. Left ventricular structure and function were assessed by 2-dimensional and speckle-tracking echocardiography. Children with MAS or RAS were 12.5±3.0 years old at enrollment, and 50% were men. Carotid intima–media thickness (0.54±0.10 versus 0.44±0.05 mm; P <0.001) and central pulse wave velocities (5.58±1.83 versus 5.00±0.90 m/s; P =0.01) were significantly higher in children with disease compared with healthy children; however, after adjustment for systolic blood pressure z score, only carotid intima–media thickness remained significantly higher in the MAS/RAS group compared with the controls (β=0.07 [0.03, 0.10]). Peripheral pulse wave velocities and carotid distensibility were normal. Children with disease had significantly increased left ventricular mass and changes in diastolic function (lower E/a ratio and lower e′ velocities). Systolic parameters, including ejection fraction, global longitudinal and circumferential strain, were similar to controls. Our findings demonstrate that children with MAS or RAS have evidence of carotid and left ventricular remodeling, without peripheral arterial involvement, which suggests a localized disease process. Left ventricular systolic function is preserved; however, subtle changes in diastolic function are observed. Carotid vessel changes are consistent with a 5- to 10-year aging, which underscores the importance of blood pressure control.

Middle aortic syndrome with renal artery stenosis

A 39-year lady referred to Vascular Surgery OPD from Cardiology with uncontrolled hypertension, non- functional left kidney and absent bilateral femoral pulses. Investigations revealed middle aortic syndrome with non-functional left kidney with bilateral renal artery stenosis. She successfully underwent bypass of stenotic segment with polyester graft from descending thoracic aorta to left common iliac artery with reverse saphenous vein graft interposed between polyester and right renal artery.

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.