Low-risk pneumatosis intestinalis in the pediatric surgical population.

BACKGROUND: Pneumatosis intestinalis (PI, presence of air in bowel wall) develops in a variety of settings and due to a variety of insults which is then characterized by varying severity and clinical course. Anecdotally, many of these cases are benign with few clinical sequelae; however, we lack evidence-based guidelines to help guide management of such lower-risk cases. We aimed to describe the clinical entity of low-risk PI, characterize the population of children who develop this form of PI, determine if management approach or clinical outcomes differed depending on the managing physician's field of practice, and finally determine if a shortened course of NPO and antibiotics was safe in the population of children with low-risk PI. METHODS: We performed a retrospective review of all children over age 1 year treated at Children's Hospital Colorado (CHCO), between 2009 and 2019 with a diagnosis of PI who did not also have a diagnosis of cancer or history of bone marrow transplant (BMT). Data including demographic variables, clinical course, and outcomes were obtained from the electronic medical record. Low-risk criteria included no need for ICU admission, vasopressor use, or urgent surgical intervention. RESULTS: Ninety-one children were treated for their first episode of PI during the study period, 72 of whom met our low-risk criteria. Among the low-risk group, rates of complications including hemodynamic decompensation during treatment, PI recurrence, Clostridium difficile colitis, and death did not differ between those who received 3 days or less of antibiotics and those who received more than 3 days of antibiotics. Outcomes also did not differ between children cared for by surgeons or pediatricians. CONCLUSIONS: Here, we define low-risk PI as that which occurs in children over age 1 who do not have a prior diagnosis of cancer or prior BMT and who do not require ICU admission, vasopressor administration, or urgent surgical intervention. It is likely safe to treat these children with only 3 days of antibiotic therapy and NPO. LEVEL OF EVIDENCE: Level III.

Association of Sociodemographic Factors with Surgical Management of Hepatoblastoma and Hepatocellular Carcinoma in Children.

OBJECTIVE: To evaluate for disparities in surgical care among US children with hepatoblastoma (HB) and hepatocellular carcinoma (HCC). STUDY DESIGN: In this retrospective National Cancer Database study (2004-2015), children aged <18 years with HB or HCC were included. Multivariable mixed-effects logistic regression was used to evaluate the association of sociodemographic factors (age, sex, race and ethnicity, insurance status, income, proximity to treating hospital) with the odds of undergoing surgical treatment after adjusting for disease-related factors (tumor size, metastasis, comorbidities) and hospital-level effects. Subgroup analyses by tumor histology were performed. RESULTS: A total of 811 children were included (HB: 80.9%; HCC: 19.1%), of which 610 (75.2%) underwent surgical treatment. Following adjustment, decreased odds of undergoing surgical treatment were associated with Black race (OR: 0.46 vs White, 95% CI [95% CI]: 0.26-0.80, P = .01), and having Medicaid (OR: 0.58 vs private, 95% CI: 0.38-0.88, P = .01) or no insurance (OR: 0.33 vs private, 95% CI: 0.13-0.80, P = .02). In children with HB, Black race was associated with decreased odds of undergoing surgical treatment (OR: 0.47 vs White, 95% CI: 0.25-0.89, P = .02). In children with HCC, Medicaid (OR: 0.10 vs private, 95% CI: 0.03-0.35, P < .001), or no insurance status (OR: 0.10 vs private, 95% CI: 0.01-0.83, P = .03) were associated with decreased odds of undergoing surgical treatment. Other than metastatic disease, no additional factors were associated with likelihood of surgical treatment in any group. CONCLUSIONS: Black race and having Medicaid or no insurance are independently associated with decreased odds of surgical treatment in children with HB and HCC, respectively. These children may be less likely to undergo curative surgery for their liver cancer.

What is the role of neutropenia in pediatric cancer patients with pneumatosis intestinalis?

BACKGROUND: We aimed to identify prognostic indicators in pneumatosis intestinalis (PI) in a pediatric oncology population. We hypothesized that neutropenia would be an independent risk factor for adverse outcomes, including the need for abdominal operation to treat PI and for the development of recurrent PI. METHODS: We performed a retrospective review of all patients treated for PI between 2009 and 2019 with a diagnosis of cancer or history of bone marrow transplant (BMT). RESULTS: Sixty-eight children were treated for their first episode of PI; 15 (22%) were not neutropenic at presentation; eight underwent urgent abdominal operation (12%). Patients with neutropenia were more likely to receive TPN, had a longer course of NPO, and received a longer course of antibiotics. Neutropenia at presentation was associated with a decreased risk of PI recurrence (40% vs 13%, p = 0.03). Children who required an abdominal operation were more likely to require vasopressors at diagnosis (50% vs 10%, p = 0.013). CONCLUSIONS: Among pediatric cancer patients, need for vasopressors at the time of PI is a marker of severe PI, with increased likelihood of requiring operative intervention. The presence of neutropenia is associated with lower rates of PI recurrence. LEVEL OF EVIDENCE: Level III.

Using the Social Vulnerability Index to Examine Disparities in Surgical Pediatric Trauma Patients.

INTRODUCTION: The Social Vulnerability Index (SVI) is a composite measure geocoded at the census tract level that has the potential to identify target populations at risk for postoperative surgical morbidity. We applied the SVI to examine demographics and disparities in surgical outcomes in pediatric trauma patients. METHODS: Surgical pediatric trauma patients (≤18-year-old) at our institution from 2010 to 2020 were included. Patients were geocoded to identify their census tract of residence and estimated SVI and were stratified into high (≥70th percentile) and low (<70th percentile) SVI groups. Demographics, clinical data, and outcomes were compared using Kruskal-Wallis and Fisher's exact tests. RESULTS: Of 355 patients included, 21.4% had high SVI percentiles while 78.6% had low SVI percentiles. Patients with high SVI were more likely to have government insurance (73.7% versus 37.2%, P < 0.001), be of minority race (49.8% versus 19.1%, P < 0.001), present with penetrating injuries (32.9% versus 19.7%, P = 0.007), and develop surgical site infections (3.9% versus 0.4%, P = 0.03) compared to the low SVI group. CONCLUSIONS: The SVI has the potential to examine health care disparities in pediatric trauma patients and identify discrete at-risk target populations for preventative resources allocation and intervention. Future studies are necessary to determine the utility of this tool in additional pediatric cohorts.

A comparative analysis of RAS variants in patients with disorders of somatic mosaicism.

PURPOSE: RAS genes (HRAS, KRAS, and NRAS) are commonly found to be mutated in cancers, and activating RAS variants are also found in disorders of somatic mosaicism (DoSM). A survey of the mutational spectrum of RAS variants in DoSM has not been performed. METHODS: A total of 938 individuals with suspected DoSM underwent high-sensitivity clinical next-generation sequencing-based testing. We investigated the mutational spectrum and genotype-phenotype associations of mosaic RAS variants. RESULTS: In this article, we present a series of individuals with DoSM with RAS variants. Classic hotspots, including Gly12, Gly13, and Gln61 constituted the majority of RAS variants observed in DoSM. Furthermore, we present 12 individuals with HRAS and KRAS in-frame duplication/insertion (dup/ins) variants in the switch II domain. Among the 18.3% individuals with RAS in-frame dup/ins variants, clinical findings were mainly associated with vascular malformations. Hotspots were associated with a broad phenotypic spectrum, including vascular tumors, vascular malformations, nevoid proliferations, segmental overgrowth, digital anomalies, and combinations of these. The median age at testing was higher and the variant allelic fraction was lower in individuals with in-frame dup/ins variants than those in individuals with mosaic RAS hotspots. CONCLUSION: Our work provides insight into the allelic and clinical heterogeneity of mosaic RAS variants in nonmalignant conditions.

Current approaches to the management of pneumatosis intestinalis: an American Pediatric Surgical Association membership survey.

PURPOSE: Pneumatosis intestinalis (PI) remains difficult to treat as it can lead to a broad range of clinical sequalae and there are little published data available to guide management. Our aim was to evaluate how pediatric surgeons currently manage children with PI, how treatment varies based on etiology, and to identify opportunities to optimize current PI management strategies. METHODS: We administered a web-based survey of practicing pediatric surgeons in the United States and Canada. The survey was distributed to all members of the American Pediatric Surgical Association. RESULTS: Of 1508 distributed surveys, 333 responses were received (22% response rate); 174 were complete and included in analysis (12% analyzed). For all scenarios, respondents recommended treatment for PI include a median 7 days of bowel rest and 7 days antibiotics. Only 41% reported their approach to PI management was optimal. Ways to optimize care include treatment based on etiology (83%), decreased number of repeat images (64%), shorter NPO course (49%), and shorter antibiotic course (47%). CONCLUSION: Pediatric surgeons manage PI similarly regardless of etiology but most report this is suboptimal. Future work is needed to prospectively evaluate management protocols that consider etiology.

How we approach pediatric congenital chylous effusions and ascites.

Congenital lymphatic leak may develop in patients with maldeveloped lymphatics and result in life-threatening fluid and electrolyte imbalance, protein deficiency, and immunodeficiency. Rapid diagnosis and therapy are necessary to prevent these complications; however, the field lacks clinical trials to support standardized diagnostic treatment guidelines. We present our current multidisciplinary approach to the diagnosis and management of congenital lymphatic leak including chylous pleural effusions and ascites. Depending on the rate of lymphatic leak, therapy can range from observation with nutritional modifications to surgical and interventional procedures aimed to reduce lymphatic drainage. Modalities to image central and peripheral lymphatics have advanced considerably. Genetic variants and subsequent targets that drive lymphatic maldevelopment have expanded the repertoire of possible pharmacotherapeutic options.

Pediatric trauma and the role of the interventional radiologist.

PURPOSE: While interventional radiologists occupy a critical role in adult trauma management, the role of interventionalist in pediatric trauma continues to evolve. The indications for transarterial embolization (TAE) are significantly different in pediatric patients in whom non-operative management (NOM) has a much more prominent role than in adults. Contrast extravasation on imaging may not require acute surgical or interventional management as it would in an adult. There are also areas in which pediatric interventional radiology is increasingly useful such as pelvic TAE in failed management, or splenic embolization to treat bleeding without the loss of splenic function inherent to surgical splenectomy. The rapid evolution of techniques and devices in pediatric patients is also changing what interventions are possible in pediatric trauma management which necessitates frequent reassessment of the guidelines and interventional radiology's role in caring for these patients. CONCLUSION: This review seeks to consolidate the recent literature to describe the evolving role of the interventional radiologist in pediatric trauma management.

Trametinib for Refractory Chylous Effusions and Systemic Complications in Children with Noonan Syndrome.

OBJECTIVE: To evaluate the effect of the RAS-MAPK pathway inhibitor trametinib on medically refractory chylous effusions in 3 hospitalized patients with Noonan syndrome. STUDY DESIGN: Pharmacologic MEK1/2 inhibition has been used to treat conditions associated with Noonan syndrome, given that activation of RAS-MAPK pathway variants leads to downstream MEK activation. We describe our experience with 3 patients with Noonan syndrome (owing to variants in 3 distinct genes) and refractory chylous effusions treated successfully with MEK inhibition. A monitoring protocol was established to standardize medication dosing and monitoring of outcome measures. RESULTS: Subjects demonstrated improvement in lymphatic leak with additional findings of improved growth and normalization of cardiac and hematologic measurements. Trametinib was administered safely, with only moderate skin irritation in 1 subject. CONCLUSIONS: Improvements in a variety of quantifiable measurements highlight the potential utility of MEK1/2 inhibition in patients with Noonan syndrome and life-threatening lymphatic disease. Larger, prospective studies are needed to confirm efficacy and assess long-term safety.

Incidence of and risk factors for perioperative blood transfusion in infants undergoing index pediatric surgery procedures.

BACKGROUND: There is a paucity of data on the frequency of transfusion during pediatric surgery index cases and guidelines for pretransfusion testing, defined as type and screen and crossmatch testing, prior to operation are not standardized. This study aimed to determine the incidence of perioperative blood transfusions during index neonatal operations and identify risk factors associated with perioperative blood transfusion to determine which patients benefit from pretransfusion testing. METHODS: A retrospective review of infants who underwent index neonatal cases between 2013 and 2019 was performed. Data were collected for patients who underwent operations for Hirschsprung's disease, esophageal atresia/tracheoesophageal fistula (EA/TEF), biliary atresia, anorectal malformation, omphalocele, gastroschisis, duodenal atresia, congenital diaphragmatic hernia (non-ECMO) or pulmonary lobectomy. Infants under 6 months were included except in the case of lobectomy where infants up to 12 months were included. RESULTS: Analysis was performed on 420 patients. Twenty-five (6.0%) patients received perioperative blood transfusion. Patients who received perioperative transfusion most commonly underwent EA/TEF repair. Patients who received perioperative transfusion had higher rates of structural heart disease (52.0% vs 17.7%, p<0.001), preoperative transfusion (48.0% vs 8.9%, p<0.001), and prematurity (52.0% vs 25.6%, p = 0.005). Presence of all three risk factors resulted in a 48% probability of requiring perioperative transfusion. CONCLUSIONS: Blood transfusion during the perioperative period of neonatal index operations is rare. Factors associated with increased risk of perioperative transfusion include prematurity, structural heart disease, and history of previous blood transfusion. LEVEL OF EVIDENCE: III.

Lymphatic malformations.

Lymphatic malformations are low-flow vascular malformations that arise due to errors in vascular development. Lymphatic malformations are benign and usually noted at birth or in the first few years of life. Lymphatic mass lesions are composed of varying size of cysts; this article focuses on discussion of cystic lymphatic malformations. Lymphatic malformations can occur throughout the body especially in lymphatic rich areas such as the cervical and axillary locations as well as the groin, trunk, retroperitoneum, extremities, abdominal or thoracic cavities. Treatment options vary based upon size of cysts and location. A multimodal and interdisciplinary approach is essential to care for patients with lymphatic malformations. Management options include observation, pharmacotherapy, sclerotherapy, and surgical procedures.

The ABC-D score improves the sensitivity in predicting need for massive transfusion in pediatric trauma patients.

PURPOSE: Early and accurate identification of pediatric trauma patients who will require massive transfusion (MT) remains difficult, and MT activation criteria are not well established. In children, the addition of shock index-pediatric age-adjusted (SIPA) to the ABC score (ABC-S) only modestly improves the sensitivity of the ABC score. We hypothesized that the discriminate ability of the ABC-S score would improve with the addition of elevated serum lactate and base deficit (ABCD score). METHODS: We identified children between 1 and 18 years old who received a pRBC transfusion between 2008 and 2018 from our trauma registry. We calculated sensitivity, specificity, and accuracy of the ABC, ABC-S, and ABCD scores to determine the need for MT. RESULTS: We included 211 children, of which 66 required MT. The best predictor of MT was achieved by adding BD and lactate to the ABC-S score, with an AUC of 0.805. An ABCD score of 3 or greater was 77.4% sensitive and 78.8% specific at predicting the need for MT. Pediatric trauma patients that required MT had higher injury severity score (p = 0.005), lactate (p = 0.002), base deficit (p = <0.0001). Mortality was higher in the MT group (45.5% vs 15.3%, p = 0.0004). CONCLUSIONS: The ABCD score improves the sensitivity of activating MT in pediatric trauma patients. STUDY TYPE: Treatment Study. LEVEL OF EVIDENCE: Level III.

Error traps and culture of safety in pediatric trauma.

Trauma is the leading cause of morbidity and mortality in the pediatric population. Due to a variety of factors, many pediatric trauma patients are initially evaluated and stabilized at adult hospitals that lack pediatric specific emergency medicine and surgical expertise. While similar to adult patients, the initial evaluation and resuscitation of pediatric patients does differ. Many of these key differences contribute to missed injury and susceptibility to error in the treatment of children. Here, we highlight a variety of differences between pediatric and adult trauma patients and clarify reasoning for these differences. Error traps that are discussed include missed cases of non-accidental trauma, missed blunt cerebrovascular injury, over use of CT (computed tomography) scans with unnecessary radiation exposure, missed small bowel or mesenteric injury, and unrecognized hemodynamic instability.

Symptom Resolution and Volumetric Reduction of Abdominal Lymphatic Malformations With Sclerotherapy.

BACKGROUND: Lymphatic malformations (LMs) are congenital and arise from errors in vascular embryogenesis. LMs are categorized by cyst size as microcystic, macrocystic, or combined. Abdominal LMs are rare. Surgical resection of abdominal LMs has been the mainstay of therapy, but recurrence and morbidity are high. We sought to determine the effectiveness of sclerotherapy treatment for abdominal LM. METHODS: A single-center, retrospective review from 2014 to 2018 was conducted evaluating pediatric patients with abdominal LM. RESULTS: Ten patients were included, n = 9 had macrocystic LM and one patient had combined disease. The average age at first treatment was 6.8 y. The most common presenting symptoms were abdominal distention, pain, infection, and anemia. Preprocedural imaging was performed for all patients; median pretreatment volume was 1572.9 cm3 (range, 67.2-13,226.4). LMs were accessed using ultrasound guidance and injected with opacified doxycycline. Patients received a mean of 7.1 sclerotherapy injections. Complications included intraperitoneal doxycycline extravasation (n = 1), managed conservatively, and LM infection (n = 1), treated with intravenous antibiotics and drainage. One patient went on to surgical resection due to inability gain stable intracystic access; follow-up ultrasonography showed no recurrence. Postprocedural imaging was available in n = 8. Volume decreased by 96.7% after sclerotherapy. The median remaining volume was 0 cm3 (range, 0-599.7) (P = 0.016). Postsclerotherapy magnetic resonance imaging was obtained in n = 6, with complete resolution in 83.3%. All patients had resolution of presenting symptoms. Follow-up duration was 12.3 mo. CONCLUSIONS: Initial results demonstrate that sclerotherapy is an effective and durable treatment for symptom resolution and volume reduction of abdominal LM.

A Single Surgeon Laparoscopic Duodenoduodenostomy Case Series for Congenital Duodenal Obstruction in an Academic Setting.

Introduction: Laparoscopic duodenoduodenostomy can be performed to repair congenital duodenal obstructions from atresia or duodenal web. There are only a few published case series in the literature. We are reporting on a single surgeon's experience with the operation and discuss the technical aspects of the operation. Material and Methods: A retrospective chart review was performed using the electronic medical record identifying all patients who underwent laparoscopic duodenoduodenostomy or duodenojejunostomy at two institutions by a singular surgeon. Results: Fifteen patients were identified as having undergone laparoscopic duodenoduodenostomy from 2010 until 2017. The weight at the time of the operation ranged from 1.5 to 8.7 kg (median 2.5 kg). The age ranged from 0 days to 15 months (median 3 days). Operative time (including other procedures) ranged from 2 hours 10 minutes to 3 hours 45 minutes with a median of 2 hours 55 minutes. One case was converted to open due to poor visualization. One patient developed a stricture that required open anastomotic revision 4 weeks after the initial surgery. In 1 patient, an enterotomy in the first portion of the duodenum was created from a retraction stitch-this was immediately recognized and repaired by primary laparoscopic closure. One patient had a small anastomotic leak that was treated with antibiotics. There were no mortalities and no intraoperative blood loss requiring transfusion. Conclusion: Laparoscopic duodenoduodenostomy is an operation that can be performed with excellent outcomes following simple steps that are easily taught in a teaching setting.

Survival after emergency department thoracotomy in the pediatric trauma population: a review of published data.

BACKGROUND/PURPOSE: The utility of EDT in the adult trauma population, using well-defined guidelines, is well established, especially for penetrating injuries. Since the introduction of these guidelines, reports on the use of EDT for pediatric trauma have been published, and these series reveal a dismal, almost universally fatal, outcome for EDT following blunt trauma in the child. This report reviews the clinical outcomes of EDT in the pediatric population. MATERIALS/METHODS: We performed a review of EDT in the pediatric population using the published data from 1980 to 2017. Variables extracted included mechanism of injury and mortality. To minimize bias, single case reports were not included in the review. RESULTS: Upon review of four decades of published literature on the use of emergency department thoracotomy (EDT) in the pediatric population, mortality rates are comparable between adults and pediatric patients for penetrating thoracic trauma. In contrast, in pediatric patients sustaining blunt trauma, no patient under the age of 15 has survived. CONCLUSION: In patients between 0 and 14 years of age presenting with no signs of life following blunt trauma, withholding EDT should be considered. Patients between the ages of 15 and 18 should be treated in accordance with adult ATLS principles for the management of thoracic trauma. LEVEL OF EVIDENCE: Level IV.

Shock index, pediatric age-adjusted (SIPA) is more accurate than age-adjusted hypotension for trauma team activation.

BACKGROUND: We demonstrated previously that shock index, pediatric age-adjusted identifies severely injured children accurately after blunt trauma. We hypothesized that an increased shock index, pediatric age-adjusted would identify more accurately injured children requiring the highest trauma team activation than age-adjusted hypotension. METHODS: We reviewed all children age 4-16 admitted after blunt trauma with an injury severity score ≥15 from January 2007-June 2013. Criteria used as indicators of need for activation of the trauma team included blood transfusion, emergency operation, or endotracheal intubation within 24 hours of admission. Shock index, pediatric age-adjusted represents maximum normal shock index based on age. Cutoffs included shock index >1.22 (ages 4-6), >1.0 (7-12), and >0.9 (13-16). Age-adjusted cutoffs for hypotension were as follows: systolic blood pressure <90 (ages 4-6), systolic blood pressure <100 (7-16). RESULTS: A total of 559 children were included; 21% underwent operation, 37% endotracheal intubation, and 14% transfusion. Hypotension alone predicted poorly the need for operation (13%), endotracheal intubation (17%), or transfusion (22%). Operation (30%), endotracheal intubation (40%), and blood transfusion (53%) were more likely in children with an increased shock index, pediatric age-adjusted; 25 children required all three interventions, 3 (12%) were hypotensive at presentation, 15 (60%) had an increased shock index, pediatric age-adjusted (P < .001). CONCLUSION: An increased shock index, pediatric age-adjusted is superior to age-adjusted hypotension to identify injured children likely to require emergency operation, endotracheal intubation, or early blood transfusion.

Rapid Response Team Activations in Pediatric Surgical Patients.

Introduction The rapid response team (RRT) is a multidisciplinary team who evaluates hospitalized patients for concerns of nonemergent clinical deterioration. RRT evaluations are mandatory for children whose Pediatric Early Warning System (PEWS) score (assessment of child's behavior, cardiovascular and respiratory status) is ≥4. We aimed to determine if there were differences in characteristics of RRT calls between children who were admitted primarily to either medical or surgical services. We hypothesized that RRT activations would be called for less severely ill children with lower PEWS score on surgical services compared with children admitted to a medical service. Materials and Methods We performed a retrospective review of all children with RRT activations between January 2008 and April 2015 at a tertiary care pediatric hospital. We evaluated the characteristics of RRT calls and made comparisons between RRT calls made for children admitted primarily to medical or surgical services. Results A total of 2,991 RRT activations were called, and 324 (11%) involved surgical patients. Surgical patients were older than medical patients (median: 7 vs. 4 years; p < 0.001). RRT evaluations were called for lower PEWS score in surgical patients compared with medical (median: 3 vs. 4, p < 0.001). Surgical patients were more likely to remain on the inpatient ward following the RRT (51 vs. 39%, p < 0.001) and were less likely to require an advanced airway than medical patients (0.9 vs. 2.1%; p = 0.412). RRT evaluations did not differ between day and night shifts (52% day vs. 48% night; p = 0.17). All surgical patients and all but one medical patient survived the event; surgical patients were more likely to survive to hospital discharge (97 vs. 91%, p < 0.001) Conclusions RRT activations are rare events among pediatric surgical patients. When compared with medical patients, RRT evaluation is requested for surgical patients with a lower PEWS score and these children are less likely to require transfer to a higher level of care, suggesting that pediatric surgery team, families, and nursing staff may not be as comfortable with clinical deterioration.

Bevacizumab and interferon reduce venous recanalization following sclerotherapy.

PURPOSE: The treatment of venous malformations is difficult because these lesions frequently recur after resection or sclerotherapy. The purpose of this study was to determine whether recanalization of sclerosed venous lumens could be prevented with systemic angiogenic inhibition using bevacizumab or peginterferon alfa-2a. METHODS: To establish an animal model of recanalization of sclerosed facial veins, 18 rabbits had ethanol sclerotherapy of 1 facial vein followed by venography after 4weeks (n=6), 12weeks (n=6), and 24weeks (n=6). Subsequently, 21 different leporids underwent sclerotherapy of both facial veins (n=42 veins) and were treated pharmacologically in three ways: (1) control (n=14); bevacizumab (n=14); or peginterferon alfa-2a (n=14). Animals received 2 systemic drug doses 1month prior to and during the procedure. Vessel patency was determined 24weeks later using venography. RESULTS: Venous recanalization occurred in 33.3% of sclerosed facial veins after 4weeks and 50.0% after 12 and 24weeks. For animals treated with systemic medication, recanalization occurred less frequently when bevacizumab (14.3%, n=2/14) (P=0.04) or peginterferon alfa-2a (7.7%, n=1/14) (P=0.01) was administered compared to controls (57.1%, n=8/14). CONCLUSIONS: Systemic treatment with bevacizumab or peginterferon alfa-2a reduces venous recanalization following sclerotherapy in an animal model. Further studies are indicated to determine whether anti-angiogenic pharmacotherapy can prevent recurrence of venous malformations in humans after sclerotherapy.