Image-Guided Transrectal Drainage of Pelvic Abscesses in Children.

OBJECTIVE: To describe our technique and share our experience with image-guided transrectal drainage (TRD) of pelvic abscesses in children. MATERIALS AND METHODS: Retrospective review and analysis of indications for image-guided TRD and examination of procedural outcomes in pediatric patients with pelvic abscesses over 8 years. RESULTS: A total of 69 patients (33 males and 36 females) with symptomatic pelvic abscesses underwent image-guided TRD. The median age and weight of the patients were 11.5 years (range, 3-18) and 46.8 kg (range, 15.1-118.0), respectively. The etiologies of the pelvic abscesses were perforated appendicitis (72.5%) and post-operative collections (27.5%). All patients presented with abdominal pain. Fever, emesis, and diarrhea were also common symptoms. The size of the pelvic abscesses ranged from 24.0 to 937.1 mL (median, 132.7). Technical success was achieved in 68 of 69 TRD procedures (98.6%). Clinical improvement was observed in all patients with technically successful TRD. The TRD catheter dwell time ranged from 0 to 10 days (median, 4.0). Most patients who underwent TRD for perforated appendicitis subsequently underwent elective appendectomy after the resolution of the pelvic abscess (84.0%). The median time from TRD to elective appendectomy was 2.8 months (range, 0.3-6.1). There were no procedure-related complications. CONCLUSION: Image-guided TRD is a safe and effective procedure with high technical and clinical success rates for the treatment of pelvic abscesses in children.

Fostering research in pediatric interventional radiology: needs assessment and suggestions for support.

BACKGROUND: Due to the rarity of pediatric diseases, collaborative research is the key to maximizing the impact of research studies. A research needs assessment survey was created to support initiatives to foster pediatric interventional radiology research. OBJECTIVE: To assess the status of pediatric interventional radiology research, identify perceived barriers, obtain community input on areas of research/education/support, and create metrics for evaluating changes/responses to programmatic initiatives. MATERIALS AND METHODS: A survey link was sent to approximately 275 members of the Society for Pediatric Interventional Radiology (SPIR) between May and October 2020. Data was collected using a web-based interface. Data collected included practice setting, clinical role, research experience, research barriers, and suggestions for future initiatives. RESULTS: Fifty-nine surveys were analyzed with a staff physician survey response rate of 28% (56/198). A wide range of practice sizes from 15 countries were represented. Respondents were predominantly staff physicians (95%; 56/59) with an average of 11 years (range: 1-25 years) of clinical experience working at academic or freestanding children's hospitals. A total of 100% (59/59) had research experience, and 70% (41/58) had published research with a mean of 30 peer-reviewed publications (range: 1-200). For job security, 56% (33/59) of respondents were expected or required to publish, but only 19% (11/58) had research support staff, and 42% (25/59) had protected research time, but of those, 36% (9/25) got the time "sometimes or never." Lack of support staff, established collaborative processes, and education were identified as top barriers to performing research. CONCLUSIONS: The needs assessment survey demonstrated active research output despite several identified barriers. There is a widespread interest within the pediatric interventional radiology community for collaborative research.

Kaposiform Lymphangiomatosis: Pathologic Aspects in 43 Patients.

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

Cerebrospinal fluid leak in epidural venous malformations and blue rubber bleb nevus syndrome.

OBJECTIVE: Clinical manifestations of blue rubber bleb nevus syndrome (BRBNS) and multifocal venous malformation (MVM) vary depending on the location of the lesions. The aim of this study was to assess the risk of developing CSF leaks in patients with epidural venous malformations (VMs). METHODS: The authors retrospectively investigated the relationship between the development of a CSF leak and the presence of epidural VMs. RESULTS: Nine patients (5 females) had epidural VMs and presentation that was confirmatory or suggestive of a CSF leak: 4 had BRBNS, 4 had MVMs, and 1 had a solitary VM. Of 66 patients with BRBNS, clinical and imaging features of CSF leak were noted in 3 (4.5%) with epidural VMs at the age of 11-44 years. A fourth patient had suggestive symptoms without imaging confirmation. An epidural blood patch was ineffective in 2 patients, both with more than one source of leakage, requiring surgical repair or decompression. Symptomatic downward displacement of the cerebellar tonsils was noted in 3 patients with MVM and 1 with a solitary VM; 3 required surgical decompression. CONCLUSIONS: These findings suggest an increased risk of CSF leak in patients with epidural VM, including BRBNS, MVMs, and solitary VMs. Awareness of the association between epidural VM and CSF leakage may facilitate earlier diagnosis and therapeutic intervention.

The use of the internal mammary vein for central venous access.

PURPOSE: To describe the use of the internal mammary vein as an alternative access for central venous catheters. METHODS: We performed a retrospective review of patients who underwent placement of central venous catheters via the internal mammary vein. Patient demographics, indication for venous access, technical success, catheter type, dwell time and indication for exchange or removal were recorded. RESULTS: Placement of central venous catheters via the internal mammary vein was attempted in 11 patients including 8 children (4 males, mean age 5.7 years) and 3 adults. The most common indication was parenteral nutrition in patients with intestinal failure (7/11). Initial needle access of the vein was successful in all patients. Catheter placement was successful in 9 and unsuccessful in 2 patients due to occlusion of the superior vena cava. There were no immediate complications. A total of 20 catheters of various sizes (3-14.5 French) and lengths (8-23 cm) were either placed (n = 12) or exchanged (n = 8). The most common indications for catheter exchange were poor function and malposition (7/8). Four catheters were removed for infection and 4 were accidentally removed. The mean dwell time was 141 days (range 0-963 days) per catheter for a total of 2829 catheter days. The total mean dwell time per patient, including primarily placed and exchanged catheters, was 314 days (range 5-963 days). CONCLUSIONS: The internal mammary vein may provide a safe alternative route for patients who have lost their traditional access veins.

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.

Vascular anomalies of the head and neck.

The head and neck are the most common site of involvement for vascular tumors and malformations, with more than half of all vascular anomalies seen in this region. Lesions in this location can cause significant disfigurement and can be associated with airway obstruction, impairment in vision or hearing, swallowing disorders and hemorrhage. Accurate diagnosis is critical in determining treatment, and interdisciplinary care is essential for optimal management. We review clinical and imaging features that are key to establishing the correct diagnosis, and review treatment modalities, with emphasis on interventional and surgical procedures.

Two-hour Observation After Liver Biopsy in Children: Clinical and Economic Outcome of a Quality Improvement Intervention.

OBJECTIVE: Following percutaneous liver biopsy performed at our institution on an outpatient basis, children traditionally were observed for 4 hours then discharged after verifying a stable hematocrit level. In June 2015, we adopted a quality improvement project with shorter 2-hour observation for patients with no known risks and the hematocrit test was abandoned.The purpose of this study is to evaluate the clinical and economic outcomes of early discharge of children following liver biopsy. METHODS: We analyzed data on 2 groups of children who underwent ultrasound-guided nontargeted core needle liver biopsy performed on outpatient basis. Group A (100 procedures with 4-hour postprocedural observation time and hematocrit test) was compared with group B (100 procedures with 2-hour observation without hematocrit test). RESULTS: Group A consisted of 92 patients (43 boys; 49 girls) with a mean age of 11.1 years and mean weight of 52.6 kg. Group B had 92 patients (47 boys; 45 girls) with a mean age of 8.9 years and mean weight of 40.5 kg. The mean length of observation was 281 minutes (range 204-540 minutes) and 147 minutes (range 86-332 minutes) for groups A and B, respectively. The mean recovery charges were reduced by 35% per procedure in group B. The tissue obtained was sufficient for pathologic diagnosis in all procedures. There were no biopsy-related complications in either group. CONCLUSIONS: Enhanced recovery with early discharge of low-risk children after 2-hour observation following percutaneous liver biopsy can be safely implemented without adversely affecting the outcome. Shorter postbiopsy observation can be cost-saving and may potentially improve patient satisfaction.

Single Procedure Saline Lavage for Treatment of Inspissated Bile.

Inspissated bile syndrome is a rare cause of cholestatic jaundice in infancy, occurring due to obstruction of the biliary ducts and gallbladder by biliary sludge. Traditional methods of treatment include surgical drainage or cholecystostomy drain placement. Both can be associated with complications and prolonged admission. We present 2 cases treated with a single percutaneous needle puncture of the gallbladder followed by saline lavage. Two neonates presented with cholestatic jaundice and sonographic evidence of biliary sludge and dilation of the common bile duct. Single sonographic-guided needle puncture of the gallbladder was followed by irrigation with saline. Clearing of the biliary sludge was confirmed by sonography and cholecystocholangiography. There was resolution of the cholestatic jaundice, with no complications or repeat procedures.

Congenital Disseminated Pyogenic Granuloma: Characterization of an Aggressive Multisystemic Disorder.

OBJECTIVE: To describe the clinical, radiologic, and histopathologic features of "congenital disseminated pyogenic granuloma" involving various organs with high morbidity related to cerebral hemorrhagic involvement. STUDY DESIGN: We searched the database of the Vascular Anomalies Center at Boston Children's Hospital from 1999 to 2019 for patients diagnosed as having multiple vascular lesions, visceral vascular tumors, congenital hemangiomatosis, multiple pyogenic granulomas, or multiple vascular lesions without a definite diagnosis. A retrospective review of the medical records, photographs, histopathologic, and imaging studies was performed. Only patients with imaging studies and histopathologic diagnosis of pyogenic granuloma were included. RESULTS: Eight children (5 male, 3 female) had congenital multifocal cutaneous vascular tumors. Lesions also were found in the brain (n = 7), liver (n = 4), spleen (n = 3), muscles (n = 4), bone (n = 3), retroperitoneum (n = 3), and intestine/mesentery (n = 2). Less commonly affected were the spinal cord, lungs, kidneys, pancreas, and adrenal gland (n = 1 each). The mean follow-up period was 21.8 months. The cerebral and visceral lesions were hemorrhagic with severe neurologic sequelae. The histopathologic diagnosis was pyogenic granuloma with prominent areas of hemorrhage and necrosis. The endothelial cells had enlarged nuclei, pale cytoplasm and were immunopositive for CD31 and negative for D2-40 and glucose transporter 1. CONCLUSIONS: Congenital disseminated pyogenic granuloma is a distinct multisystemic aggressive disorder that primarily affects the skin, brain, visceral organs, and musculoskeletal system. Differentiation of this entity from other multiple cutaneous vascular lesions is critical because of possible cerebral hemorrhagic involvement.

Fibroadipose Vascular Anomaly in the Upper Extremity: A Distinct Entity With Characteristic Clinical, Radiological, and Histopathological Findings.

PURPOSE: Fibroadipose vascular anomaly (FAVA) is an intramuscular vascular malformation that has been recently described as a distinct clinical entity. The clinical, radiological, and histopathological characteristics of FAVA in the upper extremity are reviewed. METHODS: This was a retrospective case series of upper-extremity FAVA lesions. RESULTS: We reviewed 19 patients with FAVA of the upper limb. Pain, stiffness, swelling, and flexion contractures were the most common presentations. Except for one lesion confined to the hand, all lesions either presented with or developed a contracture within 10 years. Ten patients underwent surgical debulking. Six required tendon transfer reconstruction and 3 necessitated a free functional muscle transfer. CONCLUSIONS: Fibroadipose vascular anomaly in the upper extremity requires an accurate diagnosis and may benefit from early referral to a multidisciplinary vascular anomaly center with experienced hand surgeons. Compression garments, propranolol, and sclerotherapy seem to be ineffective. Surgical resection focused on symptomatic regions with appropriate reconstruction may have benefit in salvage of limbs with compromised function. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Surgical Management of Fibroadipose Vascular Anomaly of the Lower Extremities.

BACKGROUND: Fibroadipose vascular anomaly (FAVA) is a recently-defined vascular malformation often involving the extremities and presenting in childhood. Patients may present to orthopaedic surgeons with pain, swelling, joint contractures, and leg length discrepancy. There is no established therapy or treatment paradigm. We report on outcomes following surgical excision for patients with this condition. METHODS: Between 2007 and 2016, all 35 patients that underwent excision of lower-extremity FAVA were retrospectively reviewed using a combination of medical records, radiologic findings, and telemedicine reviews. RESULTS: Mean age at initial presentation was 12.3±6.8 years. Mean follow-up from time of definitive diagnosis at our institution was 66 months (range: 12 to 161 mo). Mean follow-up after surgery was 35 months (range: 6 to 138 mo). Females were affected more than males (71% vs. 29%). The most common location of FAVA was in the calf (49%), followed by the thigh (40%). The most commonly involved muscle was gastrocnemius (29%), followed by the quadriceps (26%). At latest follow-up after surgery, there was an improvement in the proportion of patients with pain at rest (63% vs. 29%), pain with activity (100% vs. 60%), as well as analgesia use (94% vs. 37%). Fourteen patients (40%) had symptomatic residual disease or recurrence of FAVA requiring further treatment. Six patients (17%) required further surgery and 6 (17%) required further interventional radiologic procedures. Three patients (9%) required eventual amputation for intractable pain and loss of function. Lesions with direct nerve involvement were associated with persistent neuropathic symptoms at latest follow-up (P=0.002) as well as symptomatic residual disease and/or recurrence requiring further treatment (P=0.01). Seventeen patients (49%) had 19 preoperative joint contractures. Eighteen of the 19 contractures (95%) had sustained improvement at latest follow-up. CONCLUSIONS: In carefully selected patients, surgical excision of FAVA results in improvement of symptoms. However, symptomatic residual disease and/or recurrence are not uncommon. Direct nerve involvement is associated with a worse outcome. LEVEL OF EVIDENCE: Level IV-case series.

Clinical characterization and long-term outcomes in pediatric epithelioid hemangioendothelioma.

There is a paucity of information about the clinical characteristics and long-term outcomes of pediatric epithelioid hemangioendothelioma (EHE), a rare vascular neoplasm commonly presenting in adulthood. In our case series of 24 patients with EHE aged 2-26 years, the majority presented with multi-organ disease. Progression was seen in 63% of patients with a mean time to progression of 18.4 months (range: 0-72). Three patients treated with sirolimus achieved stable disease or partial response for >2.5 years. Longitudinal prospective pediatric studies are needed to develop standardized approaches to surgical and medical management.

Complex Lymphatic Anomalies and Therapeutic Options.

Complex lymphatic anomalies include a variety of disorders with overlapping clinical, histological and imaging features. The often-confusing nomenclature used for lymphatic anomalies limits timely diagnosis and treatment. The updated 2018 classification of the International Society for the Study of Vascular Anomalies divides lymphatic anomalies into several subsets.1 Newer imaging techniques including intranodal and magnetic resonance lymphangiography have improved our understanding of anatomy and function of the lymphatic system. Advances in medical, interventional, and surgical treatments have opened a realm of new therapeutic options for patients with complex lymphatic disorders.

Imaging findings in epithelioid hemangioendothelioma.

PURPOSE-OBJECTIVE: Epithelioid hemangioendothelioma (EHE) is a rare vascular malignancy with varying biologic behavior. The purpose of this study was to identify imaging findings most characteristic of EHE. METHODS: Retrospective review of clinical and imaging records in patients referred to our Vascular Anomalies Center over a 17 year period with biopsy proven EHE. RESULTS: We evaluated 29 patients (17 F) with median age of 16 years (range 2-76 y). The most common presenting symptoms were pain (n = 13) and palpable mass (n = 7). 22 (70%) had multifocal disease. Most common sites of involvement were lung (n = 25), liver (n = 16), bone (n = 12), soft tissue (n = 3) and lymph nodes (n = 1). Of patients with single site disease, 3 had lung, 3 liver, and 1 had bone lesions. In 18/25 with lung disease, there were multiple nodules of varying sizes and characteristics. In 14/16 with hepatic disease there were multiple nodules with predominantly peripheral distribution. Subcapsular retraction was seen in 10/16 and a "lollipop" sign (hepatic or portal vein tapering at the edge of a well-defined hypoenhancing lesion) identified in 5/16. Of 12 osseous lesions, 11 were lytic, 8 involved vertebrae and 9 involved the axial skeleton. CONCLUSION: EHE has varied imaging findings. The most common sites are lungs, liver, and bone, with multi-organ involvement seen in most. Lung disease is most commonly characterized by multiple nodules. Hepatic lesions demonstrate the most distinctive findings, with peripheral distribution, lack of early enhancement, subcapsular retraction and "lollipop" sign. Osseous lesions are commonly lytic and more prevalent in the axial skeleton.

A somatic activating NRAS variant associated with kaposiform lymphangiomatosis.

PURPOSE: Kaposiform lymphangiomatosis (KLA) is a rare, frequently aggressive, systemic disorder of the lymphatic vasculature, occurring primarily in children. Even with multimodal treatments, KLA has a poor prognosis and high mortality rate secondary to coagulopathy, effusions, and systemic involvement. We hypothesized that, as has recently been found for other vascular anomalies, KLA may be caused by somatic mosaic variants affecting vascular development. METHODS: We performed exome sequencing of tumor samples from five individuals with KLA, along with samples from uninvolved control tissue in three of the five. We used digital polymerase chain reaction (dPCR) to validate the exome findings and to screen KLA samples from six other individuals. RESULTS: We identified a somatic activating NRAS variant (c.182 A>G, p.Q61R) in lesional tissue from 10/11 individuals, at levels ranging from 1% to 28%, that was absent from the tested control tissues. CONCLUSION: The activating NRAS p.Q61R variant is a known "hotspot" variant, frequently identified in several types of human cancer, especially melanoma. KLA, therefore, joins a growing group of vascular malformations and tumors caused by somatic activating variants in the RAS/PI3K/mTOR signaling pathways. This discovery will expand treatment options for these high-risk patients as there is potential for use of targeted RAS pathway inhibitors.