Nghia J. Vo

Anatomic distribution of renal artery stenosis in children: implications for imaging

BackgroundRenal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment.ObjectiveTo identify locations of RAS lesions in these hypertensive children without comorbid conditions.Materials and methodsPatients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses.ResultsEighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery.ConclusionHypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

Safety and Efficacy of Drug-eluting Bead Chemoembolization for Hepatocellular Carcinoma: Comparison of Small-versus Medium-size Particles

PURPOSE To compare safety and imaging response with 100-300 μm and 300-500 μm doxorubicin drug-eluting bead (DEBs) to determine optimal particle size for chemoembolization of hepatocellular carcinoma (HCC). MATERIALS AND METHODS DEB chemoembolization using 100-300 μm (n = 39) or 300-500 μm (n = 22) LC beads loaded with 50 mg of doxorubicin was performed in 61 patients with HCC. Patient age, sex, etiology of liver disease, degree of underlying liver disease, tumor burden, and performance status were similar between the groups. All treatments were performed in a single session and represented the patients first treatment. Toxicities and imaging response in a single index tumor were analyzed using World Health Organization (WHO) and European Association for the Study of the Liver (EASL) criteria. RESULTS There was a significantly lower incidence of postembolization syndrome and fatigue after treatment in the 100-300 μm group (8% and 36%) versus the 300-500 μm group (40% and 70%) (100-300 μm group, P = .011; 300-500 μm group, P = .025). Mean change in tumor size was similar between the two groups based on WHO and EASL criteria and similar rates of objective response, but there was a trend toward a higher incidence of EASL complete response with 100-300 μm beads versus 300-500 μm beads (59% vs 36%; P = .114). CONCLUSIONS In DEB chemoembolization for treatment of HCC, 100-300 μm doxorubicin DEBs are favored over 300-500 μm doxorubicin DEBs because of lower rates of toxicity after treatment and a trend toward more complete imaging response at initial follow-up.

Propranolol Reduces Infantile Hemangioma Volume and Vessel Density

Objective To evaluate changes in infantile hemangioma tissue before and after propranolol therapy, using gray-scale and color Doppler ultrasound imaging. Study Design Case series with chart review. Setting Tertiary pediatric hospital. Subjects and Methods Medical records and image studies of head and neck infantile hemangioma patients treated with propranolol, identified in a quality improvement database, were reviewed. Patients with imaging before and at least 4 weeks following the initiation of treatment were included. Data collected included sex, age, location, and concurrent treatment. Student t tests were used to evaluate change in cutaneous lesion area, volume, and vessel density. Logistic regression was used to compare lesion area, volume, and vessel density. Results Of the 177 patients identified, 19 met inclusion criteria. Fourteen of 19 were female, and 5 of 19 were older than 1 year. Mean lesion area change with treatment was 13.0 cm2 (range, −2.8 to 28.9 cm2, P = .05). Measured volume change was a mean of 10.3 cm3 (range, 1.5-19.2 cm3, P = .01). Mean vessel density change was 4.4 vessels per cm2 (range, 2.5-6.3 vessels per cm2, P < .01). Treatment decreased clinically determined hemangioma area proportionately less than gray-scale and color Doppler ultrasound measured lesion volume. Gray-scale and color Doppler ultrasound measured treatment response did not differ with sex, lesion location, or age at propranolol initiation. Conclusion Gray-scale and color Doppler ultrasound imaging of propranolol-treated infantile hemangiomas detected a significant reduction in lesion volume and vessel density. Patient age at propranolol treatment and concomitant corticosteroid use did not affect lesion volume change.

Pelvic imaging in the stable trauma patient: is the AP pelvic radiograph necessary when abdominopelvic CT shows no acute injury?

The purpose of the study was to determine the utility of anteroposterior (AP) pelvic radiographs in stable trauma patients who will undergo or have undergone abdominopelvic CT as part of the initial trauma imaging evaluation. Radiology reports of all stable trauma patients who underwent both abdominopelvic CT and AP pelvic radiograph from 25 January through 30 April, 2003 were reviewed for findings of acute pelvic injuries. A total of 509 consecutive patients were included in this series. Of these, 449 patients (88.2%) had no acute pelvic injury revealed by abdominopelvic CT. CT showed 163 acute injuries in 60 patients. AP radiographs showed 132 acute injuries in 52 patients. No patients with a negative CT had an acute finding on the radiograph. There were eight false-negative pelvic radiographs (negative predictive value 98.25%). CT is highly accurate in excluding acute osseous pelvic injuries. In the stable trauma patient whose CT does not reveal an acute pelvic injury or who is scheduled to undergo an abdominopelvic CT as part of the initial imaging evaluation, the pelvic radiograph may be unnecessary.

Pediatric abdominal and pelvic trauma: safety and efficacy of arterial embolization.

PURPOSE Although transcatheter embolization is a well established technique to treat adults in the trauma setting, evidence is lacking in the pediatric population. This study assesses the safety and efficacy of arterial embolization for blunt abdominal and pelvic trauma in the pediatric population. MATERIALS AND METHODS A retrospective review of abdominal and pelvic angiograms in 97 pediatric patients with blunt trauma was conducted over an 11-year period. Abdominal angiography and embolization was performed for ongoing hepatic, renal, splenic, or nonvisceral retroperitoneal injury. Pelvic angiography was performed in the setting of pelvic fracture with ongoing pelvic hemorrhage. Complications and clinical success rates of these procedures were assessed. RESULTS Of the 97 pediatric patients who underwent angiography for acute abdominal or pelvic trauma, 54 (56%) required embolization involving 62 separate sites. Injury severity score greater than 15 was present in 94% of patients. Targets of embolization included the pelvis (n = 39), liver (n = 8), kidney (n = 7), spleen (n = 6), and retroperitoneum (n = 2). Effective hemorrhage control was achieved in 47 patients (87%). Overall mortality rate was 22% (12 of 54), with most deaths related to traumatic brain injury. Five complications occurred in four patients (7%), including three major complications (hepatic abscess, bile leak, and urinary incontinence). CONCLUSIONS Angiography and embolization is relatively safe and potentially effective in the setting of abdominal and pelvic trauma in the pediatric population. Angiography with embolization should be considered in the treatment algorithm for this patient population.

Single-stage excision of localized head and neck venous malformations using preoperative glue embolization.

Objective Describe single-stage removal of head and neck venous malformations using percutaneous embolization with n–butyl cyanoacrylate (n-BCA) glue prior to surgical resection. Study Design Case series with chart review. Setting Tertiary-care pediatric hospital. Subjects and Results A total of 169 venous malformations were identified between 2000 and 2012, and 102 (60.1%) were in the head and neck. Thirty-five of 102 (34.3%) were observed, 56 of 102 (54.9%) had invasive therapy, and 11 of 102 (10.8%) underwent n-BCA embolization and surgery (“GES procedure”). The median age of the glue embolization and surgery cohort was 14 years (range, 6-19), and 7 of 11 (63.6%) were female. Treated venous malformations involved the oral cavity/tongue (4/11; 36.4%) and parotid/face (7/11; 63.6%). During facial lesion excision, intraoperative facial nerve monitoring was used. All surgical sites (11/11) were closed primarily. No patient in this cohort had any posttreatment nerve deficits, dysarthria, and dysphagia or lesion persistence. Conclusions Localized venous malformations can be treated with preoperative percutaneous embolization with n-BCA glue followed by surgical excision. This technique, with selective motor nerve monitoring, appears safe and allows for complete venous malformation removal with limited nerve dissection, to allow maximal tissue and functional preservation.

Midterm follow-up of transjugular intrahepatic portosystemic shunts using polytetrafluoroethylene endografts in children

PURPOSE To report the initial experience of a pediatric centers use of expanded polytetrafluoroethylene (ePTFE) endografts for the creation of transjugular intrahepatic portosystemic shunts (TIPSs) in children. MATERIALS AND METHODS Twelve consecutive patients had a TIPS created, all with ePTFE endografts. Nine were children younger than 18 years of age: one infant (age 18 mo) and eight adolescent children with a median age of 14 years, 3 months (range, 10 y, 1 mo, to 17 y, 2 mo). All had gastric or esophageal varices. Acute variceal bleeding was the primary indication in four of nine cases (44%). Mean follow-up was 20 months (range, 4 d to 32 mo). RESULTS Technical success rate was 100%. Seven TIPSs (78%) were created with a 10-mm-diameter endograft and two (22%) were created with an 8-mm-diameter endograft. Mean portosystemic gradient was reduced from 15.9 mm Hg to 5.8 mm Hg after TIPS creation. The devices were not dilated to their nominal diameter in seven of nine cases (78%). There were no major complications or mortalities associated with TIPS creation. There was one minor complication during follow-up in which a child developed progressively increasing lethargy. Primary patency rate by ultrasound during follow-up was 100%. There were no shunt dysfunctions or repeat interventions required, and no clinical recurrences. One child received a liver transplant 4 days after TIPS creation. CONCLUSIONS TIPSs can be created in children with the use of ePTFE endografts with an excellent midterm primary patency rate and a low complication rate.

Frequency of External Iliac Artery Branch Injury in Blunt Trauma: Improved Detection with Selective External Iliac Angiography

PURPOSE To assess the utility of selective external iliac artery (EIA) angiography and the frequency of injury to branches of the EIA in cases of blunt pelvic trauma. MATERIALS AND METHODS A retrospective review of pelvic angiograms in 66 patients with blunt pelvic trauma was conducted over a 12-month period. Pelvic and femur fracture patterns were correlated to the presence of EIA injury. Pelvic arteriography was compared versus selective EIA angiography for the detection of arterial injury. RESULTS Fifty-four of 66 patients (82%) exhibited pelvic arterial injury or elicited enough suspicion for injury to warrant embolization. Internal iliac artery embolization was performed in 50 of 66 (76%). EIA branch injury was identified in 11 of 66 patients (17%), and 10 were successfully embolized. EIA branch vessel injury was identified more frequently when there was ipsilateral intertrochanteric fracture (P = .07) or ipsilateral ilium fracture (P = .07). The sensitivity of nonselective pelvic angiography in the detection of EIA branch vessel injury was 45%. CONCLUSIONS EIA branch injury occurs in a substantial fraction of patients with blunt pelvic trauma who undergo pelvic angiography. Selective EIA angiography should be considered in all patients undergoing pelvic angiography in this situation.

Cecal volvulus: a rare cause of bowel obstruction in a pediatric patient diagnosed pre-operatively by conventional imaging studies.

Cecal volvulus is an acute surgical condition that is extremely rare in children, with a mortality rate of up to 40%. The clinical symptoms are often non-specific, and pediatric patients frequently have neurological deficits with associated communication difficulties, making the clinical diagnosis extremely challenging. Conventional radiographic imaging studies play a key role in the prospective diagnosis in children. We report a rare case of cecal volvulus in a 12-year-old boy who was diagnosed pre-operatively by abdominal radiographs and a contrast enema.

Percutaneous drainage of intra-abdominal abscess in children with perforated appendicitis

BackgroundBecause the surgical management of perforated appendicitis remains controversial, percutaneous catheter drainage (PCD) has gained favor for managing periappendiceal abscess in hemodynamically stable children.ObjectiveTo determine the safety and effectiveness of PCD in children with perforated appendicitis and to identify any variables of prognostic value.Materials & methodsWe retrospectively evaluated clinical data and imaging features for 33 children undergoing PCD for periappendiceal abscess from October 2006 to February 2010. Those with preprocedural CT studies were assigned to one of three risk categories based on imaging features.ResultsAppendectomy was successfully postponed for all patients. Our technical success rate was 87.9%, with three recurrences (two requiring repeat drainage, one managed conservatively) and one possible complication (enterocutaneous fistula formation). Children with large and diffuse abscesses had a 50% rate of technical failure, which was significantly increased when compared to children with large but localized abscesses (P < 0.028). Extraluminal appendicolith, extraluminal gas, leukocytosis, ileus/obstruction and procedural variables were not reliable predictors of outcome.ConclusionPCD can be effective for managing perforated appendicitis in children. Children with large and ill-defined abscess might be at increased risk for complication or recurrence.