3D printing: a useful tool for safe clinical practice in children with complex vasculature.

BACKGROUND: 3D printing has been used in different medical contexts, although it is underutilised in paediatrics. We present the first use of 3D printing in the management of three paediatric patients with complex renovascular disease. METHODS: Patient-specific 3D models were produced from conventional 2D imaging and manufactured using 3D polyjet printing technology. All three patients had different underlying pathologies, but all underwent multiple endovascular interventions (renal artery balloon angioplasty) prior to 3D printing and subsequent vascular surgery. The models were verified by an expert radiologist and then presented to the multidisciplinary team to aid with surgical planning. RESULTS: Following evaluation of the 3D-printed models, all patients underwent successful uni/bilateral renal auto-transplants and aortic bypass surgery. The 3D models allowed more detailed preoperative discussions and more focused planning of surgical approach, therefore enhancing safer surgical planning. It influenced clinical decision-making and shortened general anaesthetic time. The families and the patients reported that they had a significantly improved understanding of the patient's condition and had more confidence in understanding proposed surgical intervention, thereby contributing to obtaining good-quality informed consent. CONCLUSION: 3D printing has a great potential to improve both surgical safety and decision-making as well as patient understanding in the field of paediatrics and may be considered in wider surgical areas.

Cardiovascular outcomes improve in children with renovascular hypertension following endovascular and surgical interventions.

BACKGROUND: Renovascular hypertension (RenoVH) is a cause of hypertension in children. A common cause of RenoVH is renal artery stenosis which acts by reducing blood supply to renal parenchyma and activating the renin-angiotensin-aldosterone axis, often leading to cardiac remodelling. This longitudinal observational study aims to describe occurrence of cardiovascular changes secondary to RenoVH and also any improvement in cardiac remodelling after successful endovascular and/or surgical intervention. METHODS: All patients with RenoVH referred to our centre, who received ≥ 1 endovascular intervention (some had also undergone surgical interventions) were included. Data were collected by retrospective database review over a 22-year period. We assessed oscillometric blood pressure and eight echocardiographic parameters pre- and post-intervention. RESULTS: One hundred fifty-two patients met inclusion criteria and had on average two endovascular interventions; of these children, six presented in heart failure. Blood pressure (BP) control was achieved by 54.4% of patients post-intervention. Average z-scores improved in interventricular septal thickness in diastole (IVSD), posterior Wall thickness in diastole (PWD) and fractional shortening (FS); left ventricular mass index (LVMI) and relative wall thickness (RWT) also improved. PWD saw the greatest reduction in mean difference in children with abnormal (z-score reduction 0.25, p < 0.001) and severely abnormal (z-score reduction 0.23, p < 0.001) z-scores between pre- and post-intervention echocardiograms. Almost half (45.9%) had reduction in prescribed antihypertensive medications, and 21.3% could discontinue all antihypertensive therapy. CONCLUSIONS: Our study reports improvement in cardiac outcomes after endovascular + / - surgical interventions. This is evidenced by BP control, and echocardiogram changes in which almost half achieved normalisation in systolic BP readings and reduction in the number of children with abnormal echocardiographic parameters. A higher resolution version of the Graphical abstract is available as Supplementary information.

Is There Really No Kit for Kids? Quantification of Manufacturer Recommendations Regarding Paediatric Use For High-Volume IR Devices.

AIMS: The development of paediatric specific devices appears to lag behind advancements in our specialty. Children could therefore be limited in the number of procedures available to them unless we continue to use and modify adult devices 'off-label'. This study quantifies the proportion of IR devices in which paediatric use is indicated by the manufacturer. MATERIALS & METHODS: Cross-sectional analysis of device instructions for use (IFU), assessing inclusion of children was performed. Vascular access, biopsy, drainage, and enteral feeding devices, from 28 companies who sponsored BSIR, CIRSE and SIR (2019-2020) as determined by the meeting websites, were included. Devices for which the IFU was not available were excluded. RESULTS: 190 (106 vascular access, 40 biopsy, 39 drainage and 5 feeding) devices with IFU's from 18 medical device manufacturers were assessed. 49/190 (26%) IFU's referenced children. 6/190 (3%) explicitly stated the device could be used in children and 1/190 (0.5%) explicitly stated the device was not for use in children. 55/190 (29%) implied they could be used in children through caution notes. The most common caution was a reference to the size of the device that could be accommodated in a child (26/190, 14%). CONCLUSIONS: This data identifies an unmet need for paediatric IR devices and could be used to support the future development of devices intended for the children we treat. There is potentially a larger proportion (29%) of devices suitable for paediatric use, but which lack manufacturer explicit support. LEVEL OF EVIDENCE: Level 2c, Cross-Sectional study.

Diagnostic yield and safety of ultrasound-guided percutaneous testicular biopsies in children.

BACKGROUND: Traditionally, testicular biopsy is performed using an open surgical approach. Ultrasound-guided percutaneous biopsy is a less invasive alternative and can be performed in children. OBJECTIVE: The aim of this study is to report our technique and to assess the diagnostic accuracy and safety of ultrasound-guided percutaneous biopsy of testicular masses in children. MATERIALS AND METHODS: This is a 16-year retrospective review of ultrasound-guided percutaneous testicular biopsies at a single pediatric hospital. RESULTS: We performed nine ultrasound-guided testicular biopsies in 9 patients (median age: 3 years, range: 4 months-11 years; median weight: 20.9 kg, range: 8.4-35 kg; median volume of testicular lesion biopsied: 4.4 mL, range: 1.2-17 mL). A percutaneous co-axial technique was used for 5/9 biopsies with absorbable gelatin sponge tract embolization performed in 4 of those biopsies. A non-co-axial technique was used in 4/9 biopsies. A median of three cores, range 2-6, were obtained. The diagnostic yield was 89% with one biopsy yielding material suggestive of, but insufficient for, a definitive diagnosis. The most common histological diagnosis was leukemic infiltration, occurring in 6/9 biopsies. Of the remaining three biopsies, one biopsy was suggestive of, but not confirmatory for, juvenile granulosa cell tumor and two biopsies confirmed normal testicular tissue; the long-term follow-up of which demonstrated normal growth and no lasting damage. There was one (clinically insignificant) complication out of nine biopsies (11%, 95% confidence interval 0-44%): a mild, self-resolving scrotal hematoma. CONCLUSION: Ultrasound-guided testicular biopsy can be performed safely in children as an alternative to open surgical biopsy, with a high diagnostic yield and low complication rate.

Shockwaves and the Rolling Stones: An Overview of Pediatric Stone Disease.

Urinary stone disease is a common problem in adults, with an estimated 10% to 20% lifetime risk of developing a stone and an annual incidence of almost 1%. In contrast, in children, even though the incidence appears to be increasing, urinary tract stones are a rare problem, with an estimated incidence of approximately 5 to 36 per 100,000 children. Consequently, typical complications of rare diseases, such as delayed diagnosis, lack of awareness, and specialist knowledge, as well as difficulties accessing specific treatments also affect children with stone disease. Indeed, because stone disease is such a common problem in adults, frequently, it is adult practitioners who will first be asked to manage affected children. Yet, there are unique aspects to pediatric urolithiasis such that treatment practices common in adults cannot necessarily be transferred to children. Here, we review the epidemiology, etiology, presentation, investigation, and management of pediatric stone disease; we highlight those aspects that separate its management from that in adults and make a case for a specialized, multidisciplinary approach to pediatric stone disease.

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.

Diagnostic yield and safety of ultrasound-guided bowel mass biopsies in children.

BACKGROUND: Traditionally, ultrasound (US)-guided bowel mass biopsies are avoided in favour of endoscopic or surgical biopsies. However, endoscopy cannot easily reach lesions between the duodenojejunal flexure and the terminal ileum and lesions not involving the mucosa may not be accessible via an endoscopic route. OBJECTIVE: The aim of this study was to report our technique and to assess the diagnostic accuracy and safety of US-guided biopsy of bowel masses in children. MATERIALS AND METHODS: We conducted a 14-year retrospective review of US-guided bowel mass biopsies at a single paediatric hospital. RESULTS: Twenty US-guided bowel mass biopsies were performed in 19 patients (median age: 6 years and 6 months, range: 22 months-17 years, median weight: 22 kg, range: 10.2-48.4 kg). For 14 biopsies, there was no other lesion that could potentially be biopsied. A percutaneous coaxial technique was used for 19 biopsies and a transanal non-coaxial biopsy was performed in 1. A median of 9 (range: 2-15) cores of tissue was obtained at each biopsy. The technical success rate and adequacy of diagnostic yield were 100%. The most common diagnosis was lymphoma, which occurred in 16 biopsies. Three biopsies contained mucosa. There was one complication out of 20 biopsies (5%, 95% confidence interval 0-15%): a self-limiting, post biopsy pyrexia. Nineteen procedures were accompanied by a bone marrow aspirate and/or trephine within 2 weeks of the bowel biopsy, only one of which was diagnostic. CONCLUSION: US-guided bowel mass biopsy can be performed safely in children, with a high diagnostic yield and low complication rate.

Pancreatic pseudocyst drainage in children by image-guided cystogastrostomy and stent insertion.

BACKGROUND: Endoscopic ultrasound is seldom available at paediatric centres; therefore drainage of pancreatic pseudocysts in children has traditionally been achieved by surgery. OBJECTIVE: This study assessed the feasibility and safety of performing image-guided internal drainage of pancreatic pseudocysts with a flanged self-expanding covered nitinol pancreatic pseudocyst drainage stent. MATERIALS AND METHODS: We conducted a retrospective case note review of children undergoing image-guided cystogastrostomy at two paediatric hospitals. Percutaneous access to the stomach was achieved via an existing gastrostomy tract or image-guided formation of a new tract. Under combined ultrasound, fluoroscopic or cone-beam CT guidance the pancreatic pseudocysts were punctured through the posterior wall of the stomach. A self-expanding covered nitinol stent was deployed to create a cystogastrostomy opening. RESULTS: Image-guided cystogastrostomy was performed in 6 children (4 male; median age 6 years, range 46 months to 15 years; median weight 18 kg, range 13.8-47 kg). Two children had prior failed attempts at surgical or endoscopic drainage. Median maximum cyst diameter was 11.5 cm (range 4.7-15.5 cm) pre-procedure. Technical success was 100%. There were no complications. There was complete pseudocyst resolution in five children and a small (2.1-cm) residual pseudocyst in one. Pseudocyst-related symptoms resolved in all children. CONCLUSION: Pancreatic pseudocyst drainage can be successfully performed in children by image-guided placement of a cystogastrostomy stent. In this cohort of six children there were no complications.

Non-vascular interventional radiology in the paediatric alimentary tract.

Paediatric interventional radiology is an evolving speciality which is able to offer numerous minimally invasive treatments for gastrointestinal tract pathologies. Here we describe interventions performed by paediatric interventional radiologists on the alimentary tract from the mouth to the rectum. The interventions include sclerotherapy, stricture management by dilation, stenting and adjunctive therapies such as Mitomycin C administration and enteral access for feeding, motility assessment and administration of enemas.

Cardiovascular Manifestations and Complications of Loeys-Dietz Syndrome: CT and MR Imaging Findings.

Loeys-Dietz syndrome (LDS) is a recently described genetic connective tissue disorder with a wide spectrum of multisystem involvement. LDS is characterized by rapidly progressive aortic and peripheral arterial aneurysmal disease. LDS and the other inherited aortopathies such as Marfan syndrome have overlapping phenotypic features. However, LDS is characterized by a more aggressive vascular course; patient morbidity and mortality occur at an early age, with complications developing at relatively smaller aortic dimensions. In addition, there is more diffuse arterial involvement in LDS, with a large proportion of patients developing aneurysms of the iliac, mesenteric, and intracranial arteries. Early diagnosis and careful follow-up are essential for ensuring timely intervention in patients with arterial disease. Cross-sectional angiography has an important role in the baseline assessment, follow-up, and evaluation of acute complications of LDS, the thresholds and considerations of which differ from those of other inherited aortopathies. In this article, LDS is compared with other genetic vascular connective tissue disorders. In addition, the genetic, histopathologic, and cardiovascular manifestations of this disease process are reviewed, with a focus on computed tomographic and magnetic resonance imaging findings. Online DICOM image stacks and supplemental material are available for this article. ©RSNA, 2018.

The effect of reducing spatial resolution by in-plane partial volume averaging on peak velocity measurements in phase contrast magnetic resonance angiography.

BACKGROUND: The aim of this study was to quantify the degree of the effect of in-plane partial volume averaging on recorded peak velocity in phase contrast magnetic resonance angiography (PCMRA). METHODS: Using cardiac optimized 1.5 Tesla MRI scanners (Siemens Symphony and Avanto), 145 flow measurements (14 anatomical locations; ventricular outlets, aortic valve (AorV), aorta (5 sites), pulmonary arteries (3 sites), pulmonary veins, superior and inferior vena cava)- in 37 subjects (consisting of healthy volunteers, congenital and acquired heart disease patients) were analyzed by Siemens Argus default voxel averaging technique (where peak velocity = mean of highest velocity voxel and four neighbouring voxels) and by single voxel technique (1.3×1.3×5 or 1.7×1.7×5.5 mm3) (where peak velocity = highest velocity voxel only). The effect of scan protocol (breath hold versus free breathing) and scanner type (Siemens Symphony versus Siemens Avanto) were also assessed. Statistical significance was defined as P<0.05. RESULTS: There was a significant mean increase in peak velocity of 7.1% when single voxel technique was used compared to voxel averaging (P<0.0001). Significant increases in peak velocity were observed by single voxel technique compared to voxel averaging regardless of subject type, anatomical flow location, scanner type and breathing command. Disabling voxel averaging did not affect the volume of flow recorded. CONCLUSIONS: Reducing spatial resolution by the use of voxel averaging produces a significant underestimation of peak velocity. While this is of itself not surprising this is the first report to quantify the size of the effect. When PCMRA is used to assess peak velocity recording pixel averaging should be disabled.

Thrombus length estimation in acute ischemic stroke: a potential role for delayed contrast enhanced CT.

PURPOSE: Thrombus length has been shown to be an important determinant of recanalization using intravenous thrombolysis in hyperacute ischemic stroke. Various studies have attempted to quantify thrombus based on non-contrast CT (NCCT) or CT angiography (CTA). However, thrombus may not be seen on NCCT, and CTA may fail to delineate the distal extent of the thrombus. Contrast enhanced CT (CECT) following CTA can be used to estimate infarct core, but we investigated whether the angiographic data available on these images provided reliable information on thrombus length. MATERIALS AND METHODS: 15 consecutive patients, mean age 81 years (range 63-93), with terminal internal carotid artery or M1-middle cerebral artery occlusions underwent NCCT, CTA (bolus tracked technique), and CECT (acquired 80 s post initial CTA injection). Three radiologists assessed thrombus length on thin slice NCCT, and CTA and CECT. RESULTS: CTA overestimated thrombus length relative to NCCT (p<0.001) and CECT (p<0.001). There was less difference between CTA and CECT estimation in patients with good collateral scores (p<0.05). There was good correlation between NCCT and CECT (Pearson's correlation coefficient=0.90, 95% CI 0.81 to 0.95, p<0.001). Inter-rater reliability assessed using intraclass correlation was 0.95 (95% CI 0.87 to 0.98) for NCCT and 0.98 (95% CI 0.94 to 0.99) for CECT. CONCLUSIONS: CTA regularly overestimates thrombus length as the distal end of the thrombus is not delineated. This can be overcome through the use of a CECT acquisition which can reliably be used to estimate thrombus length.