Evaluation and management of biliary complications after pediatric liver transplantation: pearls and pitfalls for percutaneous techniques.

In pediatric liver transplantation, bile duct complications occur with a greater incidence than vascular anastomotic dysfunction and represent a major source of morbidity and mortality. While surgical re-anastomosis can reduce the need for retransplantation, interventional radiology offers minimally invasive and graft-saving therapies. The combination of small patient size and prevailing Roux-en-Y biliary enteric anastomotic techniques makes endoscopic retrograde cholangiopancreatography difficult if not impossible. Expertise in percutaneous management is therefore imperative. This article describes post-surgical anatomy, pathophysiology and noninvasive imaging of biliary complications. We review percutaneous techniques, focusing heavily on biliary access and interventions for reduced liver grafts. Subsequently we review the results and adverse events of these procedures and describe conditions that masquerade as biliary obstruction.

Value of Antibiotic Prophylaxis for Percutaneous Gastrostomy: A Double-Blind Randomized Trial.

PURPOSE: To compare peristomal infection rates following percutaneous gastrostomy (PG) after a single dose of prophylactic antibiotics versus placebo and evaluate rates of peristomal infection in patients receiving concurrent antibiotics. MATERIALS AND METHODS: This single-center, randomized trial (2012-2016) enrolled 122 patients referred for image-guided PG; all enrolled patients completed the study. Of enrolled patients, 68 were randomly assigned to receive either antibiotics (n = 34) or placebo (n = 34) before PG placement. The remaining 54 patients were taking pre-existing antibiotics and were assigned to an observation arm. Stoma sites were assessed for signs of infection by a blinded evaluator at early (between 3-5 d and 7-10 d) and late (between 14-17 d and 28-30 d) time points after the procedure. The primary outcome was peristomal infection. RESULTS: Under intention-to-treat analysis, early infection rate was 11.8% (4/34 patients; 95% CI, 0.0%-9.4%) in the placebo arm and 0.0% (0/34 patients; 95% CI, 0.0%-8.4%) in the antibiotic arm (P = .057 for comparison of infections in the 2 arms). Under per-protocol analysis, early infection rate was 13.3% (4/30 patients; 95% CI, 4.4%-29.1%) in the placebo arm and 0.0% (0/32 patients; 95% CI, 0.0%-8.9%) in the antibiotic arm (P = .049). The number needed to treat to prevent 1 early infection was 8.5 and 7.5 from the 2 analyses, respectively. CONCLUSIONS: There is a trend toward reduction in rate of peristomal infection after PG when prophylactic antibiotics are administered.

An Interventionalist's Guide to Hemoptysis in Cystic Fibrosis.

Massive hemoptysis occurs in a minority of patients with cystic fibrosis, with an annual incidence of 1%. Although rare, massive hemoptysis can be a severe and potentially fatal complication of this disease. Beyond the acute life-threatening event, hemoptysis in patients with cystic fibrosis has been associated with faster decline in lung function, accelerated need for lung transplant, and increased mortality. The bronchial arteries are the culprit vessels in over 90% of cases of hemoptysis. This normally quiescent vascular system undergoes remarkable hypertrophy, collateralization, and angiogenesis before the onset of hemoptysis, introducing numerous pitfalls for the interventionalist. However, in experienced hands, bronchial artery embolization is a safe and potentially lifesaving therapy. Preprocedural noninvasive imaging, specifically computed tomographic angiography, has been repeatedly validated for helping to localize the likely site of bleeding, characterizing pertinent arterial anatomy, and promoting efficient and effective intervention; it has been recommended for all stable patients with hemoptysis. Success in the angiographic suite requires a thorough understanding of normal and variant bronchial arterial anatomy, appropriate patient selection, and a meticulous embolization technique. A meticulous approach to imaging and intervention, conscientious of both visualized and nonvisualized collateral pathways and nontarget vessels, can minimize potentially devastating complications. This review summarizes the current literature, modern procedural techniques, and emerging controversies, serving to guide an evolving approach to management of patients with cystic fibrosis and hemoptysis. ©RSNA, 2018.

Doppler ultrasound predictors of transplant hepatic venous outflow obstruction in pediatric patients.

OBJECTIVE: To investigate Doppler US and catheter venogram correlates to improve detection of transplant HVOO and avoid unnecessary invasive imaging procedures. MATERIALS AND METHODS: A retrospective review was performed in all pediatric OLT patients undergoing catheter venography of the hepatic veins between 2007 and 2017 at a single large tertiary pediatric liver transplant institution. RESULTS: Forty-four transplant hepatic venograms in 32 OLT patients were included (mean 1.38, range 1-4 venograms per patient). All venograms were preceded by an independent Doppler US examination. Twenty-one (47.7%) venograms were performed for the investigation of suspected HVOO based on Doppler US alone, 19 (43.2%) were performed for TJLB without suspected HVOO, 4 (9.1%) were performed for both. Sixteen (36.3%) instances of >50% anastomotic stenosis were identified. Mean peak anastomotic velocities were 208 cm/s and 116 cm/s in the presence and absence of a >50% venographic stenosis, respectively (P < 0.004). In all cases where there was a monophasic waveform seen on Doppler US, there was a > 50% stenosis seen on hepatic vein venogram. In all cases where a triphasic waveform was seen on Doppler US, there was no stenosis seen on hepatic vein venogram. CONCLUSION: While a Doppler US velocity threshold providing both high sensitivity and specificity has yet to be identified, increasing peak anastomotic velocity and decreasing intrahepatic venous velocity correlate strongly with venographic outflow stenosis. The presence of a triphasic intrahepatic waveform provides good NPV.

Segmental Yttrium-90 Radioembolization versus Segmental Chemoembolization for Localized Hepatocellular Carcinoma: Results of a Single-Center, Retrospective, Propensity Score-Matched Study.

PURPOSE: To compare segmental radioembolization with segmental chemoembolization for localized, unresectable hepatocellular carcinoma (HCC) not amenable to ablation. MATERIALS AND METHODS: In a single-center, retrospective study (2010-2015), 101 patients with 132 tumors underwent segmental radioembolization, and 77 patients with 103 tumors underwent segmental doxorubicin-based drug-eluting embolic or conventional chemoembolization. Patients receiving chemoembolization had worse performance status (Eastern Cooperative Oncology Group 0, 76% vs 56%; P = .003) and Child-Pugh class (class A, 65% vs 52%; P = .053); patients receiving radioembolization had larger tumors (32 mm vs 26 mm; P < .001), more infiltrative tumors (23% vs 9%; P = .01), and more vascular invasion (18% vs 1%; P < .001). Toxicity, tumor response, tumor progression, and survival were compared. Analyses were weighted using a propensity score (PS). RESULTS: Toxicity rates were low, without significant differences. Index and overall complete response rates were 92% and 84% for radioembolization and 74% and 58% for chemoembolization (P = .001 and P < .001). Index tumor progression at 1 and 2 years was 8% and 15% in the radioembolization group and 30% and 42% in the chemoembolization group (P < .001). Median progression-free and overall survival were 564 days and 1,198 days in the radioembolization group and 271 days and 1,043 days in the chemoembolization group (PS-adjusted P = .002 and P = .35; censored by transplant PS-adjusted P < .001 and P = .064). CONCLUSIONS: Segmental radioembolization demonstrates higher complete response rates and local tumor control compared with segmental chemoembolization for HCC, with similar toxicity profiles. Superior progression-free survival was achieved.

An Interventionist's Guide to Endocrine Consultations.

Endocrinopathies are a heterogeneous group of disorders often resulting from pathologic sources of hormone production. When the clinical scenario, laboratory testing, and noninvasive imaging fail to aid confident identification of the source of hormone excess, endocrine venous sampling may localize obscure lesions to guide subsequent treatment. Knowledge of basic hormone signaling pathways, common pathophysiologic disruptions of these pathways, and serologic evaluation fosters informed conversations with referring physicians and effective patient selection. Success in the angiography suite requires familiarity with normal and variant anatomy of the multiple organs of the endocrine system, patient preparation, stimulation and sampling techniques, specimen handling, and results interpretation. ©RSNA, 2017.

Cone-Beam CT with Fluoroscopic Overlay Versus Conventional CT Guidance for Percutaneous Abdominopelvic Abscess Drain Placement.

PURPOSE: To compare technical success and procedure time for percutaneous abscess drain placement with fluoroscopic cone-beam computed tomography (CT) and two-axis needle guidance versus conventional CT guidance. MATERIALS AND METHODS: A total of 85 consecutive patients undergoing abdominopelvic abscess drain placement guided by fluoroscopic cone-beam CT or conventional CT were retrospectively reviewed over a 2-year period. Forty-three patients underwent drain placement with cone-beam CT using XperGuide navigation and 42 underwent placement with conventional 64-slice CT. Patient characteristics, median abscess size (6.8 cm vs 7.8 cm; P = .14), and depth to abscess (7.2 cm vs 7.7 cm; P = .88) were similar between groups. RESULTS: Technical success rates were 98% (42 of 43) in the cone-beam CT group and 100% (42 of 42) in the conventional CT group (P = .32), with a 10-F pigtail drainage catheter inserted in the majority of cases. There were no complications in either group. There was no significant difference in effective dose between groups (9.6 mSv vs 10.7 mSv; P = .30). Procedure times were significantly shorter in the cone-beam CT group (43 min vs 62 min; P = .02). In addition, during the study period, there was a gradual improvement in procedure time in the cone-beam CT group (50% reduction), whereas procedure time did not change for the conventional CT group. CONCLUSIONS: Cone-beam CT guidance appears to be equivalent to conventional CT guidance for drain placement into medium-sized abdominopelvic collections, yielding similar technical success rates and radiation doses, with the additional benefit of reduced procedure times.

Finding the Nidus: Detection and Workup of Non-Central Nervous System Arteriovenous Malformations.

Vascular anomalies are a diverse group of pathologic conditions. They have different manifestations, natural histories, and treatments. Compared with other vascular malformations, arteriovenous malformations (AVMs) are considered the most symptomatic and difficult to manage. AVMs inherently progress and have a high rate of recurrence after treatment. Imaging helps provide an accurate and early diagnosis, which can then be used to direct appropriate management, with embolization evolving as the primary therapy. Thus, radiology plays a crucial role in the detection, workup, and management of AVMs. Ultrasonography (US) is a useful initial imaging modality, particularly when AVMs involve the extremities or a superficial or accessible location. Limitations include poor identification of soft-tissue and bone components, as well as suboptimal evaluation of deep or complex AVMs. Magnetic resonance (MR) angiography is the preferred imaging modality for AVMs and should be considered in any symptomatic patient or in the initial evaluation of vascular anomalies that are equivocal at US. Computed tomographic angiography should be reserved for those patients who are unable to undergo MR angiography or for evaluation of acute symptoms, such as bleeding or airway compromise. Conventional catheter-based angiography is useful for real-time depiction and evaluation of AVMs, particularly in the planning and execution of endovascular treatment and in the diagnosis of an AVM when findings from noninvasive imaging are equivocal for a high-flow component. As with the diagnostic workup, MR angiography is the preferred posttreatment modality. (©)RSNA, 2016.

Beyond decreased bowel enhancement: acute abnormalities of the mesenteric and portal vasculature.

Acute mesenteric ischemia (AMI) is a potentially life-threatening condition with an associated high mortality. Prompt diagnosis is crucial to achieve a favorable outcome. The radiologist plays a central role in the initial evaluation of a patient with suspected AMI. In this pictorial essay, we review the appropriate imaging evaluation of a patient with suspected AMI, and we review both the common and uncommon etiologies of mesenteric ischemia. With each etiology presented, relevant clinical and imaging findings, as well as potential treatments, are reviewed.

Radiology of foreign bodies: how do we image them?

To assess the sensitivity of detecting the most commonly encountered foreign bodies in Emergency Radiology using all imaging modalities (conventional radiography, computed tomography, ultrasound, and magnetic resonance imaging). The following materials were inserted into a pig-leg phantom and imaged using conventional radiography, computed tomography, ultrasound, and magnetic resonance imaging: Plastics #1, 2, 3, 5, and compostable plastic; dry and wet wood, aluminum, gravel, glass (tinted and non-tinted), and Salmon and Halibut fish bones. The visibility of plastic is variable on both conventional radiography and computed tomography, depending on composition, but all types of plastic are well visualized on ultrasound. Wood is most easily identified and localized on both computed tomography and ultrasound, is only faintly visible on conventional radiography, and is not well visualized on magnetic resonance imaging. Gravel, glass, and aluminum are well visualized on all modalities, with the exception of magnetic resonance imaging, where there is significant artifact surrounding the foreign body. Fish bones (Halibut and Salmon) are well visualized on conventional radiography, computed tomography, and ultrasound. Conventional radiography and computed tomography are great modalities for detecting foreign bodies of various compositions. Computed tomography is particularly useful at localizing the foreign body and determining its relationship to surrounding structures and its depth of involvement. All foreign bodies are visualized on ultrasound if the location is known and the foreign body is in the plane of the transducer. Magnetic resonance imaging is not helpful in detecting foreign bodies.

Abnormal skin, limb and craniofacial morphogenesis in mice deficient for interferon regulatory factor 6 (Irf6).

Transcription factor paralogs may share a common role in staged or overlapping expression in specific tissues, as in the Hox family. In other cases, family members have distinct roles in a range of embryologic, differentiation or response pathways (as in the Tbx and Pax families). For the interferon regulatory factor (IRF) family of transcription factors, mice deficient in Irf1, Irf2, Irf3, Irf4, Irf5, Irf7, Irf8 or Irf9 have defects in the immune response but show no embryologic abnormalities. Mice deficient for Irf6 have not been reported, but in humans, mutations in IRF6 cause two mendelian orofacial clefting syndromes, and genetic variation in IRF6 confers risk for isolated cleft lip and palate. Here we report that mice deficient for Irf6 have abnormal skin, limb and craniofacial development. Histological and gene expression analyses indicate that the primary defect is in keratinocyte differentiation and proliferation. This study describes a new role for an IRF family member in epidermal development.

Surgical resection of a malignant liver lesion: what the surgeon wants the radiologist to know.

OBJECTIVE: Hepatic malignancy is a common and lethal disease, whether due to a primary tumor or metastasis. There are numerous treatment options available depending on the stage of the disease and medical condition of the patient, including systemic chemotherapy, transcatheter embolization, thermal ablation, and surgical resection. In a subset of patients with liver malignancy, surgical resection can offer the best chance of long-term survival and potentially even cure. This article reviews the major indications and contraindications for resection, basic surgical techniques and terminology, key clinical and imaging preoperative workup, and pertinent interventional oncology procedures in the management of hepatic malignancy. CONCLUSION: Diagnostic and interventional radiology plays an important role in the assessment and treatment of malignant hepatic lesions. Radiologists should be familiar with how surgeons select, work up, and treat candidates for liver resection to provide the most clinically valuable service.

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.

Percutaneous thrombectomy of upper extremity and thoracic central veins using Inari ClotTriever System: Experience in 14 patients.

Objective: In the present report, we have described the technical and clinical outcomes of percutaneous thrombectomy in the deep veins of the upper extremity and thorax using the ClotTriever system (Inari Medical, Irvine, CA). Methods: Fourteen patients with symptomatic deep venous occlusive disease in the upper extremity deep veins and thoracic central veins who had undergone thrombectomy using the ClotTriever system between October 2020 and January 2022 were reviewed. The technical results, adverse events, imaging follow-up data, and clinical outcomes were recorded. Results: Fourteen patients (seven men and seven women; mean age, 53.6 ± 13.3 years) constituted the study cohort. Of the 14 patients, 9 (64.3%) had had DVT due to intravascular invasion or external compression from known malignancy, 2 (14.3%) had had infected thrombi and/or vegetation due to Staphylococcus aureus refractory to intravenous antibiotic therapy, and 3 (21.4%) had had a benign etiology for thrombus formation. The presenting symptoms included upper extremity and/or facial swelling (n = 14), upper extremity pain (n = 6), fever (n = 2), and dyspnea (n = 1). Thrombectomy with the ClotTriever system was successfully completed in all 14 patients. Seven patients (50.0%) had required additional venous stent reconstruction after thrombectomy to address the underlying stenosis. No major adverse events were noted. All the patients had experienced resolution of the presenting symptoms. Conclusions: For the management of symptomatic deep venous occlusive disease of the upper extremity deep veins and thoracic central veins, thrombectomy using the ClotTriever system was feasible with excellent technical and clinical success.

Kissing Viabahn VBX stent graft reconstruction of thoracic central veins for management of superior vena cava syndrome.

OBJECTIVE: In the present study, we evaluated the technical and clinical outcomes of thoracic central vein reconstruction for superior vena cava (SVC) syndrome using kissing Viabahn VBX stent grafts (W.L. Gore & Associates, Flagstaff, AZ). METHODS: All adult patients with SVC syndrome who had undergone attempted bilateral brachiocephalic vein-to-SVC reconstruction using kissing VBX stent grafts at an academic hospital between August 2019 and February 2021 were reviewed. The technical results, adverse events, imaging follow-up findings, and clinical outcomes were recorded. Patency over time was assessed using Kaplan-Meier analysis. RESULTS: A total of 28 patients (16 women and 12 men; mean age, 52.0 years) constituted the study cohort. Of the 28 patients, 17 (60.7%) had had benign and 11 (39.3%) malignant etiologies. The presenting symptoms included neck swelling (n = 17; 60.7%), bilateral upper extremity swelling (n = 15; 53.6%), dyspnea (n = 7; 25%), unilateral upper extremity swelling (n = 4; 14.3%), and dysphagia (n = 1; 3.6%). SVC reconstruction with VBX stent grafts in a kissing configuration was successfully completed in 27 of the 28 patients (96.4%). Four major adverse events were noted in the benign etiology subgroup (23.5%), including intraprocedural hemopericardium (n = 3) and delayed pneumothorax (n = 1). Of the 28 patients, 27 (96.4%) had experienced resolution of their presenting symptoms. The mean clinical follow-up for the living patients was 358.8 ± 77.2 days (range, 78-645 days). The mean imaging follow-up for the living patients was 272.6 ± 91 days (range, 26-594 days). The primary, primary-assisted, and secondary patency rates at 12 months were 71.8%, 88.8%, and 100%, respectively. CONCLUSIONS: For the management of SVC syndrome, thoracic central vein reconstruction with kissing VBX stent grafts was feasible with a high rate of symptom resolution and acceptable patency. However, this technique should not be recommended for those with benign SVC syndrome owing to the high risk of cardiac tamponade.

Hepatic abscess complicating transarterial chemoembolization in a patient with liver metastases.

Hepatic abscess following transarterial chemoembolization is an uncommon complication. The authors describe a case of liver abscess after transarterial chemoembolization for neuroendocrine liver metastases, including risk factors, prophylaxis, treatment, and outcomes.