Kevin S. H. Koo

MRI phenotypes of localized intravascular coagulopathy in venous malformations

BackgroundThe incidence of localized intravascular coagulopathy (LIC) in venous malformations varies with lesion size and location, as well as the presence of palpable phleboliths. The development of LIC can cause pain and hemorrhage and can progress to disseminated intravascular coagulopathy (DIC) and thromboembolic disease resulting in death in some cases. Early recognition of LIC can relieve symptoms and prevent progression to life-threatening complications.ObjectiveThe aim of this work was to identify MRI features of venous malformation associated with LIC. We hypothesized that venous malformations with larger capacitance, slower flow and less physiological compression (greater stasis) were more likely to be associated with LIC.Materials and methodsIn this HIPAA-compliant and IRB-approved study, we retrospectively reviewed clinical records and MRI for consecutive patients undergoing evaluation of venous malformations at our multidisciplinary Birthmarks and Vascular Anomalies Center between 2003 and 2013. Inclusion required consensus diagnosis of venous malformation and availability of laboratory data and MRI; patients on anticoagulation or those previously undergoing surgical or endovascular treatment were excluded. LIC was diagnosed when D-dimer exceeded 1,000xa0ng/mL and/or fibrinogen was less than 200xa0mg/dL. Two board-certified radiologists assessed the following MRI features for each lesion: morphology (spongiform vs. phlebectatic), presence of phleboliths, size, location (truncal vs. extremity), and tissue type(s) involved (subcutis, muscle, bone and viscera). Univariate logistic regression analyses were used to test associations between LIC and MRI findings, and stepwise regression was applied to assess the significance of the individual imaging predictors.ResultsSeventy patients, 37 with LIC, met inclusion criteria during the 10-year study period (age: 14.5 +/- 13.6 years [mean +/- standard deviation]; 30 male, 40 female). Both elevated D-dimer and low fibrinogen were associated with the presence of phleboliths, larger lesion sizes and visceral involvement on MRI (all Pu2009<u20090.05). In stepwise regressions, lesion size (Pu2009<u20090.001), the presence of phleboliths (Pu2009=u20090.005) and lesion morphology (Pu2009=u20090.006) were all significant predictors of LIC.ConclusionLIC is associated with larger lesion size, visualized phleboliths, truncal location and spongiform morphology on MRI in venous malformations, suggesting that lesions with larger capacitance, slower flow and less physiological compression are more likely to be associated with coagulopathy.

Transforaminal intrathecal delivery of nusinersen using cone-beam computed tomography for children with spinal muscular atrophy and extensive surgical instrumentation: early results of technical success and safety

BackgroundNusinersen, the only treatment approved by the United States Food and Drug Administration for spinal muscular atrophy (SMA), is delivered intrathecally. Many children with SMA have extensive spinal instrumentation and deformities, often precluding the use of standard approaches for gaining intrathecal access. Furthermore the anatomical distortion that often occurs with rotoscoliosis can complicate the use of fluoroscopic guidance. Compared to fluoroscopy, CT affords superior guidance for complex needle placements. This opens up alternatives to the posterior (interlaminar) technique, including transforaminal and caudal approaches.ObjectiveThis study describes the early results of technical success, complications and radiation dose of intrathecal delivery of nusinersen using cone-beam CT guidance with two-axis fluoroscopic navigational overlay.Materials and methodsWe conducted a retrospective review of 15 consecutive nusinersen injections performed in four children with SMA and extensive spinal hardware precluding standard posterior lumbar puncture techniques. These children were treated using transforaminal thecal access employing cone-beam CT with navigational overlay. We analyzed results including technical success, complications and total fluoroscopy time.ResultsAll procedures were technically successful. No major complications and one minor complication were reported; the minor complication was a post-procedural neuropathic headache that was attributed to procedural positioning and was treated successfully with gabapentin. The average procedural fluoroscopy time and air kerma were 1.9xa0min and 55.8xa0mGy, respectively.ConclusionCone-beam CT guidance with two-axis navigational overlay is a safe, effective method for gaining transforaminal intrathecal access in children with spinal abnormalities and hardware precluding the use of standard techniques.

Emergent embolization of a ruptured splenic artery aneurysm complicating Menkes disease

We report a 7-year-old boy with Menkes disease complicated by rupture of a large splenic artery aneurysm. The aneurysm was successfully embolized with microcoils and n-butyl cyanoacrylate. Further angiographic evaluation revealed marked tortuosity of mesenteric and lower extremity vasculature, including the femoral arteries bilaterally, without aneurysm formation. The patient has since been evaluated annually with computed tomography angiography and there have been no additional vascular complications of his disease during 3-year follow up.

Ultrasound-guided lumbar puncture in pediatric patients: technical success and safety

BackgroundDisadvantages of fluoroscopically guided lumbar puncture include delivery of ionizing radiation and limited resolution of incompletely ossified posterior elements. Ultrasound (US) allows visualization of critical soft tissues and the cerebrospinal fluid (CSF) space without ionizing radiation.ObjectiveTo determine the technical success and safety of US-guided lumbar puncture in pediatric patients.Materials and methodsA retrospective review identified all patients referred to interventional radiology for lumbar puncture between June 2010 and June 2017. Patients who underwent lumbar puncture with fluoroscopic guidance alone were excluded. For the remaining procedures, technical success and procedural complications were assessed. Two hundred and one image-guided lumbar punctures in 161 patients were included. Eighty patients (43%) had previously failed landmark-based attempts.ResultsOne hundred ninety-six (97.5%) patients underwent lumbar puncture. Five procedures (2.5%) were not attempted after US assessment, either due to a paucity of CSF or unsafe window for needle placement. Technical success was achieved in 187 (95.4%) of lumbar punctures attempted with US guidance. One hundred seventy-seven (90.3%) were technically successful with US alone (age range: 2xa0days-15xa0years, weight range: 1.9-53.1xa0kg) and an additional 10 (5.1%) were successful with US-guided thecal access and subsequent fluoroscopic confirmation. Three (1.5%) cases were unsuccessful with US guidance but were subsequently successful with fluoroscopic guidance. Of the 80 previously failed landmark-based lumbar punctures, 77 (96.3%) were successful with US guidance alone. There were no reported complications.ConclusionUS guidance is safe and effective for lumbar punctures and has specific advantages over fluoroscopy in pediatric patients.

Transsplenic splenoportography and portal venous interventions in pediatric patients

BackgroundData regarding transsplenic portal venous access for diagnostic imaging and endovascular intervention in children are limited, possibly due to concerns regarding high bleeding risks and resultant underutilization.ObjectiveTo investigate the safety and utility of transsplenic splenoportography and portal venous interventions in children.Materials and methodsA retrospective review was performed of all pediatric patients undergoing percutaneous transsplenic portal venous access and intervention at two large tertiary pediatric institutions between January 2012 and April 2017 was performed. Parameters assessed included procedural indications, procedural and relevant prior imaging, technical details of the procedures, laboratory values and clinical follow-up.ResultsTranssplenic portal venous access was achieved in all patients. Diagnostic transsplenic splenoportography was performed in 22 patients and was 100% successful at providing the desired anatomical and functional information. Four transsplenic portal venous interventions were performed with 100% success: meso-Rex shunt angioplasty, snare targeted transjugular intrahepatic portosystemic shunt (TIPS) creation through cavernous transformation, pharmacomechanical thrombectomy for acute thrombosis, and transplant portal vein angioplasty. Intraperitoneal bleeding occurred in 2/26 (7.7%) and one case required transfusion (3.8%). No cases of hemorrhage were observed when transsplenic access size was 4 Fr or smaller.ConclusionTranssplenic splenoportography in children is safe and effective when noninvasive imaging methods have yielded incomplete information. Additionally, a transsplenic approach has advantages for complex portal interventions. Bleeding risks are proportional to tract access size and may be mitigated by tract embolization.

Effects of Mechanical Complications on Radiation Exposure During Fluoroscopically Guided Gastrojejunostomy Exchange in the Pediatric Population

The purpose of the article is to evaluate the effects of mechanical complications, such as clogging or coiling, of gastrojejunostomy tubes on radiation exposure during exchange in the pediatric population. In this HIPAA-compliant and IRB-approved study, we retrospectively reviewed procedural records for patients undergoing gastrojejunostomy (GJ) tube exchange during a 4-month period in 2014. Success of the procedure, specifications of the tube, age, and sex of the patient as well as radiation exposure during the procedure were included. Radiation exposure was measured in fluoroscopy time and cumulative air kerma. Complications encountered during exchange were also recorded, if available. Patients presenting for gastrostomy to GJ conversions or combined procedures were excluded from the study. Ordinary and mixed effect linear regression models were used to test associations between GJ tube parameters, presence of mechanical complications, and fluoroscopy time and radiation dose. 146 patients undergoing 285 GJ exchanges met inclusion criteria over the 4-month study period (M:F 82:64). All exchanges were successful with 85 demonstrating a form of mechanical complication (44 coiled, 41 clogged). Of the reported GJ tube specifications, only tube length was significantly associated with mechanical complications (pxa0<xa00.001). The presence of mechanical complication was significantly associated with increased radiation exposure and fluoroscopy time (pxa0<xa00.0001). Mechanical complications of gastrojejunostomy tubes, such as clogging or coiling, are associated with increased radiation exposure during exchange. Strategies to decrease these complications, including re-siting the gastrostomy tract or placement of a surgical jejunostomy in the event of repeated coiling of a tube should be strongly considered.

Emergent stent-graft repair of a massive aortic pseudoaneurysm secondary to Behçet’s disease in a child

An 11-year-old male with vasculitis was found to have a large abdominal aortic pseudoaneurysm on diagnostic angiography. This report describes endovascular repair of the pseudoaneurysm by stent-graft exclusion. The existing literature surrounding this rare and potentially fatal condition is also reviewed.

Chylous effusion presenting in a 37-year-old woman with severe hypothyroidism: a case report

IntroductionWe report what is to the best of our knowledge the second adult case of chylothorax clearly associated with severe hypothyroidism in the English-language medical literature. To the best of our knowledge, this is the first case of its kind reported without a prior history of malignancy.Case presentationA 37-year-old Hispanic woman with no reported significant past medical history initially presented with shortness of breath and inability to lose weight. She was found to have a large chylous effusion requiring chest-tube drainage, as well as severe hypothyroidism. After several weeks of thyroid hormone-replacement therapy, the formation of chylous pleural fluid in the patient greatly diminished, and the chest tube was removed. Upon long-term follow-up her minimal residual effusion remains stable on serial chest radiographs.ConclusionAlthough the exact pathophysiologic relation between low thyroid hormone levels and chyle formation remains to be elucidated, hypothyroidism should be a diagnostic consideration in patients with chylous effusions, especially those refractory to conventional treatments.