Monitoring and Follow-Up of High Radiation Dose Cases in Interventional Radiology.

RATIONALE AND OBJECTIVES: To assess the implementation of radiation dose monitoring software, create a process for clinical follow-up and documentation of high-dose cases, and quantify the number of patient reported radiation-induced tissue reactions in fluoroscopically guided interventional radiology (IR) and neuro-interventional radiology (NIR) procedures. MATERIALS AND METHODS: Web-based radiation dose monitoring software was installed at our institution and a process to flag all procedures with reference point air kerma (Ka,r) > 5000 mGy was implemented. The entrance skin dose was estimated and formal reports generated, allowing for physician-initiated clinical follow-up. To evaluate our process, we reviewed all IR and NIR procedures performed at our hospital over a 1-year period. For all procedures with Ka,r > 5000 mGy, retrospective medical chart review was performed to evaluate for patient reported tissue reactions. RESULTS: Three thousand five hundred eighty-two procedures were performed over the 1-year period. The software successfully transferred dose data on 3363 (93.9%) procedures. One thousand three hundred ninety-three (368 IR and 1025 NIR) procedures were further analyzed after excluding 2189 IR procedures with Ka,r < 2000 mGy. Ten of 368 (2.7%) IR and 52 of 1025 (5.1%) NIR procedures exceeded estimated skin doses of 5000 mGy. All 10 IR cases were abdominal/pelvic trauma angiograms with/without embolization; there were no reported tissue reactions. Of 52 NIR cases, 49 were interventions and 3 were diagnostic angiograms. Five of 49 (10.2%) NIR patients reported skin/hair injuries, all of which were temporary. CONCLUSION: Software monitoring and documentation of radiation dose in interventional procedures can be successfully implemented. Radiation-induced tissue reactions are relatively uncommon.

Adjustable diameter TIPS in the pediatric patient: the constrained technique.

Placement of transjugular intrahepatic portosystemic shunt (TIPS) is necessary in children with portal hypertension complicated by variceal bleeding or ascites. However, placement of adult-sized endografts may be problematic due to the smaller anatomy of pediatric patients. On the other hand, placement of fixed diameter smaller stents have the corresponding problem of not accommodating future growth of the child. We describe a novel method to create an adjustable diameter TIPS as a technical solution to these problems. In this technique, a balloon expandable bare metal stent is placed concentrically around the ePTFE TIPS endograft, creating an intentional narrowing in the shunt diameter than can be expanded with balloon dilation at future procedures as needed. This allows for optimal calibration of shunt hemodynamics according to the child's growth and prevents the potential need for placement of additional shunts or technically challenging TIPS reduction procedures.

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.

Pediatric Percutaneous Osteoid Osteoma Ablation: Cone-Beam CT with Fluoroscopic Overlay Versus Conventional CT Guidance.

PURPOSE: To compare technical success, clinical success, complications, radiation dose, and total room utilization time for osteoid osteoma thermal (radiofrequency or microwave) ablation using cone-beam computed tomography (CBCT) with two-axis fluoroscopic navigational overlay versus conventional computed tomography (CT) guidance. MATERIALS AND METHODS: A retrospective review was performed to identify all osteoid osteoma ablations performed over a 5.5-year period at a single tertiary care pediatric hospital. Twenty-five ablations (15 radiofrequency and 10 microwave) in 23 patients undergoing fluoroscopic CBCT-guided osteoid osteoma ablation were compared to 35 ablations (35 radiofrequency) in 32 patients undergoing ablation via conventional CT guidance. Dose area product and dose length product were recorded for CBCT and conventional CT, respectively, and converted to effective doses. Technical success, clinical success (cessation of pain and medication use 1 month after ablation), complications, radiation dose, and total room utilization time were compared. RESULTS: All procedures were technically successful. Twenty-two of 25 (88.0%) CBCT and 31 of 35 (88.6%) conventional CT-guided ablations achieved immediate clinical success. There were two minor complications in each group and no major complications. Mean effective radiation dose was significantly lower for CBCT compared to CT guidance (0.12 vs. 0.39 mSv, p = 0.02). Mean total room utilization time for CBCT was longer (133.5 vs. 97.5 min, p = 0.0001). CONCLUSIONS: Fluoroscopic CBCT guidance for percutaneous osteoid osteoma ablation yields similar technical and clinical success, reduced radiation dose, and increased total room utilization time compared to conventional CT guidance.

Primary choriocarcinoma of the bilateral basal ganglia presenting in a teenaged male.

Primary intracranial choriocarcinoma (PICCC), a type of germ-cell tumor, is a very rare primary tumor of the central nervous system that generally arises in the pineal or suprasellar region. We present a case of a teenage boy with PICCC of the bilateral basal ganglia, an anatomic site for which we were unable to find the previous reports. We offer discussion of the differential diagnosis, imaging characteristics, and prognosis of PICCC and germ-cell tumors of the basal ganglia, in the hope that it will increase awareness and allow for early detection.

Percutaneous Bullectomy in Conjunction with Endobronchial Valve Placement as an Alternative to Surgical Management of Giant Bullae.

We present the first reported case of the treatment and management of a giant bulla using percutaneous bullectomy and endobronchial valve placement. A 74-year-old woman with chronic obstructive pulmonary disease and a known large bulla in the left chest presented to the emergency department with acute-onset confusion after a traumatic fall. She was subsequently diagnosed with an intracranial hemorrhage in the distribution of the right basal ganglia. Chest imaging revealed a giant apical bulla occupying 80% of the left hemithorax. In addition, there was midline shift away from the affected side associated with volume loss in the right hemithorax and no radiographic evidence of aeration in the remainder of the left lung. Arterial blood gas analysis revealed significant hypercapnia. Surgical bullectomy was not an option, and thus, a novel approach was utilized to treat this patient.

Portosystemic Shunts: Stable Utilization and Improved Outcomes, Two Decades After the Transjugular Intrahepatic Portosystemic Shunt.

PURPOSE: The aim of this study was to assess national trends in utilization, demographics, hospital characteristics, and outcomes of patients undergoing surgical or percutaneous portal decompression since the introduction of transjugular intrahepatic portosystemic shunts (TIPS). METHODS: A retrospective analysis of patients undergoing surgical portal decompression and TIPS procedures was conducted using Medicare Physician/Supplier Procedure Summary Master Files from January 2003 through December 2013 and National (Nationwide) Inpatient Sample data from 1993, 2003, and 2012. Utilization rates normalized to the annual number of Medicare enrollees, estimated means, and 95% confidence intervals were calculated. RESULTS: The Medicare total annual utilization rate per million for all portosystemic decompression procedures decreased by 6.5% during the study period, from 15.3 in 2003 to 14.3 in 2013. TIPS utilization increased by 19.4% (from 10.3 to 12.3 per million), whereas open surgical shunt utilization decreased by 60.0% (from 5.0 to 2.0 per million). TIPS procedures represented 86% of all procedures in 2013. From 1993 to 2012, mean age increased slightly (from 53.0 to 55.5 years, P < .05). The percentage of procedures performed at teaching hospitals increased, whereas in-hospital mortality and length of stay decreased by 42% (P < .05) and 20% (P < .05), respectively. Of factors evaluated, the performance of procedures on an elective basis was the most influential on in-hospital mortality (P < .01, all years studied) and length of stay (P < .0001, all years studied). CONCLUSIONS: Approximately two decades after the introduction of TIPS, the utilization of all portal decompression procedures has remained relatively stable. The TIPS procedure represents the dominant portal decompression technique. In-hospital mortality and mean length of stay after decompression have decreased, partially because of the performance of procedures during elective admissions.

Blunt impacts to the back: Biomechanical response for model development.

The development of advanced injury prediction models requires biomechanical and injury tolerance information for all regions of the body. While numerous studies have investigated injury mechanics of the thorax under frontal impact, there remains a dearth of information on the injury mechanics of the torso under blunt impact to the back. A series of hub-impact tests were performed to the back surface of the mid-thorax of four mid-size male cadavers. Repeated tests were performed to characterize the biomechanical and injury response of the thorax under various impact speeds (1.5m/s, 3m/s and 5.5m/s). Deformation of the chest was recorded with a 59-gage chestband. Subject kinematics were also recorded with a high-speed optoelectronic 3D motion capture system. In the highest-severity tests, peak impact forces ranged from 6.9 to 10.5 kN. The peak change in extension angle measured between the 1st thoracic vertebra and the lumbar spine ranged from 39 to 62°. The most commonly observed injuries were strains of the costovertebral/costotransverse joint complexes, rib fractures, and strains of the interspinous and supraspinous ligaments. The majority of the rib fractures occurred in the rib neck between the costovertebral and costotransverse joints. The prevalence of rib-neck fractures suggests a novel, indirect loading mechanism resulting from bending moments generated in the rib necks caused by motion of the spine. In addition to the injury information, the biomechanical responses quantified here will facilitate the future development and validation of human body models for predicting injury risk during impact to the back.

Injury tolerance of the wrist and distal forearm to impact loading onto outstretched hands.

BACKGROUND: The wrist/forearm complex is one of the most commonly fractured body regions, yet the impact tolerance of the wrist is poorly understood. This study sought to quantify the injury tolerance of the adult male forearm-wrist complex under loading simulating axial impact to an outstretched hand. METHODS: Fifteen isolated cadaveric forearm/wrist specimens were tested. Loading was applied via an instrumented drop tower device designed to impact the palmar surface of the hand with the wrist extended to approximately 90 degrees. Impact severity was modulated by adjusting the boundary condition of the elbow. Elbow reaction force and deformation of the specimen (deflection of the palmar surface of the hand toward the elbow) were measured. Bone-implanted strain gauges were used to detect the time of fracture. Injury risk functions were developed using parametric survival analysis with a cumulative Weibull distribution. RESULTS: Of 14 specimens, 10 exhibited a fracture to the wrist or forearm after test (one specimen was excluded from the analysis). Injury severities varied from nondisplaced fractures of the radius to severely displaced fractures and/or fracture-dislocations of the carpal bones. Of the potential predictors studied, the specimen deflection expressed as a percentage of the initial specimen length produced the injury risk model of best fit (50% risk of fracture at 1.69% deflection; 95% confidence interval, 1.38-2.07% deflection). The value of the elbow reaction force corresponding to a 50% risk of injury was 4.34 kN (3.80-4.97 kN). CONCLUSION: These results provide information for the prediction of wrist and forearm injury in biomechanical models simulating impacts in the field and provide tolerance information for the development of injury mitigation countermeasures.

Spontaneous cervical artery dissection: the borgess classification.

BACKGROUND AND PURPOSE: The pathogenesis of spontaneous cervical artery dissections (sCAD) and its best medical treatment are debated. This may be due to a lack of clear classification of sCAD. We propose the new Borgess classification of sCAD, based on the presence or absence of intimal tear as depicted on imaging studies and effect on blood flow. MATERIALS AND METHODS: This is a single-center investigator-initiated registry on consecutive patients treated for sCAD. In the Borgess classification, type I dissections have intact intima and type II dissections have an intimal tear. RESULTS: Forty-four patients and 52 dissected arteries were found. Forty-nine of 52 dissections (93%) were treated with dual anti-platelet therapy. Twenty-one of 52 dissections were type I; 31 were type II. Type I dissections were more likely to present with ischemic symptoms [stroke, transient ischemic attack (TIA)] (p = 0.001). More type I dissections occurred in the vertebral artery, while more type II dissections occurred in the internal carotid artery (p < 0.001). Follow-up averaged 18.1 months (range: 3-108 months) with no recurrent ischemic events (stroke, TIA), deaths, or hemorrhage. Forty-six vessels had 6 month follow-up on medical treatment; 19/46 (41%) healed. Type I dissections were more likely to heal than type II (p < 0.001). CONCLUSION: The two dissection types in the Borgess classification appear to relate to clinical presentation and rate of healing, making the classification useful in clinical management. Dual anti-platelet therapy for sCAD seems to have a very low risk of subsequent stroke; however, a large prospective study is needed to investigate the best treatment.

Tumor necrosis factor-α in liver ischemia/reperfusion injury.

The pathophysiology of hepatic ischemia/reperfusion injury (IRI) includes a number of complex and diverse mechanisms involving interactions between hepatocytes, Kupffer cells, neutrophils, macrophages, sinusoidal endothelial cells, and platelets. Tumor Necrosis Factor-α (TNF-α), a cytokine produced by numerous cell types in response to inflammatory stimuli, is a well-known mediator during ischemia/reperfusion (IR) that plays a central role in injury to hepatocytes. TNF-α has a multifactorial effect in hepatic IRI because of the many interactions between TNF-α and reactive oxygen species, nitric oxide, adhesion molecules, and various cytokines and chemokines. The intracellular cascades that TNF-α triggers and their downstream effects are clearly presented throughout this manuscript. With these mechanisms in mind, ischemic preconditioning and pharmacological interventions with potential clinical application to prevent or attenuate IRI will be emphasized.

Extracellular pressure stimulates adhesion of sarcoma cells via activation of focal adhesion kinase and Akt.

BACKGROUND: The effect of extracellular pressure on adhesion and adhesiogenic focal adhesion kinase (FAK) and Akt signaling in sarcomas was investigated. METHODS: Human sarcoma cells (HT-1080 fibrosarcoma, KHOS-240S osteosarcoma, and A-673 rhabdomyosarcoma) were subjected to increased pressure followed by adhesion assay. Two cell lines were pretreated with the FAK inhibitor 1,2,4,5-benzenetetraamine tetrahydrochloride (Y15) or Akt IV inhibitor, followed by Western analysis for activated FAK and Akt. Parallel studies were conducted in cells from a resected human fibrous histiosarcoma. RESULTS: Pressure increased adhesion in all 3 sarcoma lines and primary histosarcoma cells by 7% to 18% (n = 6; P < .01 each). Pressure activated FAK and Akt (n = 5; P < .01). Inhibiting FAK or Akt inhibited FAK or Akt phosphorylation and the stimulation of adhesion by increased pressure (n = 5 each; P < .01 each). CONCLUSIONS: Pressure increases sarcoma cell adhesiveness via Akt and FAK. Perioperative manipulation or forces in lymphatic or circulatory systems may potentiate local recurrence or distant metastasis.

Optimized cryopreservation method for human dental pulp-derived stem cells and their tissues of origin for banking and clinical use.

Dental pulp is a promising source of mesenchymal stem cells with the potential for cell-mediated therapies and tissue engineering applications. We recently reported that isolation of dental pulp-derived stem cells (DPSC) is feasible for at least 120h after tooth extraction, and that cryopreservation of early passage cultured DPSC leads to high-efficiency recovery post-thaw. This study investigated additional processing and cryobiological characteristics of DPSC, ending with development of procedures for banking. First, we aimed to optimize cryopreservation of established DPSC cultures, with regards to optimizing the cryoprotective agent (CPA), the CPA concentration, the concentration of cells frozen, and storage temperatures. Secondly, we focused on determining cryopreservation characteristics of enzymatically digested tissue as a cell suspension. Lastly, we evaluated the growth, surface markers and differentiation properties of DPSC obtained from intact teeth and undigested, whole dental tissue frozen and thawed using the optimized procedures. In these experiments it was determined that Me(2)SO at a concentration between 1 and 1.5M was the ideal cryopreservative of the three studied. It was also determined that DPSC viability after cryopreservation is not limited by the concentration of cells frozen, at least up to 2x10(6) cells/mL. It was further established that DPSC can be stored at -85 degrees C or -196 degrees C for at least six months without loss of functionality. The optimal results with the least manipulation were achieved by isolating and cryopreserving the tooth pulp tissues, with digestion and culture performed post-thaw. A recovery of cells from >85% of the tissues frozen was achieved and cells isolated post-thaw from tissue processed and frozen with a serum free, defined cryopreservation medium maintained morphological and developmental competence and demonstrated MSC-hallmark trilineage differentiation under the appropriate culture conditions.

Collection, cryopreservation, and characterization of human dental pulp-derived mesenchymal stem cells for banking and clinical use.

Recent studies have shown that mesenchymal stem cells (MSC) with the potential for cell-mediated therapies and tissue engineering applications can be isolated from extracted dental tissues. Here, we investigated the collection, processing, and cryobiological characteristics of MSC from human teeth processed under current good tissue practices (cGTP). Viable dental pulp-derived MSC (DPSC) cultures were isolated from 31 of 40 teeth examined. Of eight DPSC cultures examined more thoroughly, all expressed appropriate cell surface markers and underwent osteogenic, adipogenic, and chondrogenic differentiation in appropriate differentiation medium, thus meeting criteria to be called MSC. Viable DPSC were obtained up to 120 h postextraction. Efficient recovery of DPSC from cryopreserved intact teeth and second-passage DPSC cultures was achieved. These studies indicate that DPSC isolation is feasible for at least 5 days after tooth extraction, and imply that processing immediately after extraction may not be required for successful banking of DPSC. Further, the recovery of viable DPSC after cryopreservation of intact teeth suggests that minimal processing may be needed for the banking of samples with no immediate plans for expansion and use. These initial studies will facilitate the development of future cGTP protocols for the clinical banking of MSC.