Venous Access: National Guideline and Registry Development (VANGUARD): Advancing Patient-Centered Venous Access Care Through the Development of a National Coordinated Registry Network

There are over 8 million central venous access devices inserted each year, many in patients with chronic conditions who rely on central access for life-preserving therapies. Central venous access device-related complications can be life-threatening and add tens of billions of dollars to health care costs, while their incidence is most likely grossly mis- or underreported by medical institutions. In this communication, we review the challenges that impair retention, exchange, and analysis of data necessary for a meaningful understanding of critical events and outcomes in this clinical domain. The difficulty is not only with data extraction and harmonization from electronic health records, national surveillance systems, or other health information repositories where data might be stored. The problem is that reliable and appropriate data are not recorded, or falsely recorded, at least in part because policy, payment, penalties, proprietary concerns, and workflow burdens discourage completeness and accuracy. We provide a roadmap for the development of health care information systems and infrastructure that address these challenges, framed within the context of research studies that build a framework of standardized terminology, decision support, data capture, and information exchange necessary for the task. This roadmap is embedded in a broader Coordinated Registry Network Learning Community, and facilitated by the Medical Device Epidemiology Network, a Public-Private Partnership sponsored by the US Food and Drug Administration, with the scope of advancing methods, national and international infrastructure, and partnerships needed for the evaluation of medical devices throughout their total life cycle.

Research Priorities for Percutaneous Arteriovenous Fistula Creation in Patients with End-Stage Renal Disease: Proceedings and Recommendations from a Multidisciplinary Research Consensus Panel

Recently developed endovascular techniques to create percutaneous arteriovenous fistulas are an alternative to surgical arteriovenous fistula creation, although there is currently a lack of high-level evidence regarding their creation, maturation, utilization, and long-term function. Recognizing this, the Society of Interventional Radiology Foundation sponsored a Research Consensus Panel and Summit for the prioritization of a research agenda to identify and address the gaps in current knowledge.

Evidence-Based Strategies and Recommendations for Preservation of Central Venous Access in Children

Children with chronic illness often require prolonged or repeated venous access. They remain at high risk for venous catheter-related complications (high-risk patients), which largely derive from elective decisions during catheter insertion and continuing care. These complications result in progressive loss of the venous capital (patent and compliant venous pathways) necessary for delivery of life-preserving therapies. A nonstandardized, episodic, isolated approach to venous care in these high-need, high-cost patients is too often the norm, imposing a disproportionate burden on affected persons and escalating costs. This state-of-the-art review identifies known failure points in the current systems of venous care, details the elements of an individualized plan of care, and emphasizes a patient-centered, multidisciplinary, collaborative, and evidence-based approach to care in these vulnerable populations. These guidelines are intended to enable every practitioner in every practice to deliver better care and better outcomes to these patients through awareness of critical issues, anticipatory attention to meaningful components of care, and appropriate consultation or referral when necessary.

Recommended Clinical Trial End Points for Dialysis Catheters

Central venous catheters are used frequently in patients on hemodialysis as a bridge to a permanent vascular access. They are prone to frequent complications, including catheter-related bloodstream infection, catheter dysfunction, and central vein obstruction. There is a compelling need to develop new drugs or devices to prevent central venous catheter complications. We convened a multidisciplinary panel of experts to propose standardized definitions of catheter end points to guide the design of future clinical trials seeking approval from the Food and Drug Administration. Our workgroup suggests diagnosing catheter-related bloodstream infection in catheter-dependent patients on hemodialysis with a clinical suspicion of infection (fever, rigors, altered mental status, or unexplained hypotension), blood cultures growing the same organism from the catheter hub and a peripheral vein (or the dialysis bloodline), and absence of evidence for an alternative source of infection. Catheter dysfunction is defined as the inability of a central venous catheter to (1) complete a single dialysis session without triggering recurrent pressure alarms or (2) reproducibly deliver a mean dialysis blood flow of >300 ml/min (with arterial and venous pressures being within the hemodialysis unit parameters) on two consecutive dialysis sessions or provide a Kt/V≥1.2 in 4 hours or less. Catheter dysfunction is defined only if it persists, despite attempts to reposition the patient, reverse the arterial and venous lines, or forcefully flush the catheter. Central vein obstruction is suspected in patients with >70% stenosis of a central vein by contrast venography or the equivalent, ipsilateral upper extremity edema, and an existing or prior history of a central venous catheter. There is some uncertainty about the specific criteria for these diagnoses, and the workgroup has also proposed future high-priority studies to resolve these questions.

Long-term central venous access in pediatric patients at high risk: conventional versus antibiotic-impregnated catheters

PURPOSE

To study selective use of antibiotic-impregnated catheters in children at increased risk of venous catheter-related infections (CRIs).

MATERIALS AND METHODS

From December 2008 to June 2009, 428 peripherally inserted central catheters (PICCs) were placed by the interventional radiology service of a large metropolitan children's hospital. This retrospective study analyzed demographic and outcome data for the 125 patients in this group at high risk for venous CRI. Patients at high risk were those with active systemic infection, previous complicated central venous access, intensive care unit (ICU) admission, intestinal failure, transplantation, complex congenital heart disease, or renal failure. Patients (age, 7.6 y ± 7.0; 73 male and 52 female) received a conventional or antibiotic-impregnated PICC, with 17 receiving more than one catheter.

RESULTS

Of the 146 of 428 qualifying patient encounters (34%), 53 patients received an antibiotic-impregnated PICC and 93 received a conventional PICC, representing 5,080 total catheter-days (CDs). The rates of CRIs per 1,000 CDs, including catheter exit site infections and catheter-related bloodstream infections, were 0.86 for antibiotic-impregnated PICCs and 5.5 for conventional PICCs (P = .036). A propensity-based model predicts 15-fold greater infection-free survival over the lifetime of the catheter in patients who receive an antibiotic-impregnated PICC (P < .001). Antibiotic-impregnated PICC recipients with active infection or ICU admission at the time of insertion had no catheter-associated infections, compared with 3.42 and 9.46 infections per 1,000 CDs, respectively, for patients who received conventional PICCs. Patients with intestinal failure had 1.49 and 10 infections per 1,000 CDs with antibiotic-impregnated versus conventional PICCs, respectively.

CONCLUSIONS

Antibiotic-impregnated long-term PICCs significantly improve infection-free catheter survival in pediatric patients at high risk.

Barriers to the successful treatment of liver disease by hepatocyte transplantation

Management of patients with hepatic failure and liver-based metabolic disorders is complex and expensive. Hepatic failure results in impaired coagulation, altered consciousness and cerebral function, a heightened risk of multiple organ system failure, and sepsis [1]. Such manifold problems are only treatable today and for the foreseeable future by transplantation. In fact, whole or auxiliary partial liver transplantation is often the only available treatment option for severe, even if transient, hepatic failure. Patients with life-threatening liver-based metabolic disorders similarly require organ transplantation even though their metabolic diseases are typically the result of a single enzyme deficiency, and the liver otherwise functions normally. For all of the benefits it may confer, liver transplantation is not an ideal therapy, even for severe hepatic failure. More than 17,000 patients currently await liver transplantation in the United States, a number that seriously underestimates the number of patients that need treatment [2], as it has been estimated that more than a million patients could benefit from transplantation [3]. Unfortunately, use of whole liver transplantation to treat these disorders is limited by a severe shortage of donors and by the risks to the recipient associated with major surgery [4].

Botulinum toxin A injection of salivary glands in children with drooling and chronic aspiration

PURPOSE

To review outcomes of ultrasound (US)-guided percutaneous submandibular gland injection of botulinum toxin A (BTX-A) in the treatment of drooling and chronic aspiration.

MATERIALS AND METHODS

A 3-year retrospective review was performed of 220 US-guided salivary gland injections in 36 patients. There were 21 male patients and 15 female patients with an age range of 1.4 to 19.8 years (mean, 8.6 y) and a weight range of 7.8 to 73 kg (mean, 24.4 kg). The mean pretreatment analysis period was 48 months and the mean follow-up period was 21 months. The study group was divided into groups with anterior (n = 9) and posterior (n = 27) drooling, with those with both (n = 10) included in the posterior group.

RESULTS

All procedures were technically successful. Bilateral submandibular injections were performed in 34 procedures and bilateral submandibular and parotid injections were performed in 38 procedures. Of the 27 patients with posterior drooling, improvement occurred in 24 patients (88%), no improvement was seen in two (8%), and one (4%) was lost to follow-up. Of the nine patients with anterior drooling, six (66%) showed improvement, there was no response in two (22%), and one (12%) was lost to follow-up. The total number of hospitalizations for respiratory issues and presumed aspiration pneumonia decreased by 56.4% per year in the patients with posterior drooling. There was one procedure-related complication: an episode of self-limited oral bleeding.

CONCLUSION

Salivary gland BTX-A injection for salivary control shows promising results in decreasing saliva production and frequency of respiratory symptoms in children with drooling and chronic aspiration.

Benefit of fluoroscopically guided intraarticular, long-acting corticosteroid injection for subtalar arthritis in juvenile idiopathic arthritis

BACKGROUND

Children with arthritis may endure a lifetime of disfigurement, dysfunction, and pain if acute inflammation progresses to chronic changes in the joint cartilage and underlying bone. Intraarticular steroids have become an integral component of treatment, but at times are difficult to deliver to joints, such as the subtalar joint, that have complex anatomies.

OBJECTIVE

We describe our technique and outcomes using fluoroscopically guided intraarticular subtalar steroid injection in patients with active symptoms of juvenile idiopathic arthritis (JIA).

MATERIALS AND METHODS

Fluoroscopically guided subtalar joint injections were performed in 38 children (mean age 6.7 years). Medical records were reviewed retrospectively and improvement was evaluated clinically by the degree of foot movement in eversion and inversion.

RESULTS

Subtalar joint injection was technically successful in 100% of the JIA patients with improvement in physical symptoms in 34/38 (89%). Of the 38 children, 32 were followed up within 13 weeks of the initial injection and, therefore, satisfied the eligibility criteria for resolution of arthritis. Of these 32 children, 14 showed clinical resolution (44%). The mean duration of improvement was 1.2 +/- 0.9 years. Children with a longer interval (>1 year) from diagnosis to treatment had significantly less resolution (P = 0.04). Local subcutaneous atrophy or hypopigmentation were observed in 53% of the children after steroid injection (20/38). These minor complications were associated with a greater volume of steroid injected into the site per child (P = 0.02).

CONCLUSION

Fluoroscopically guided subtalar joint injection is an effective treatment for subtalar arthropathy. Prompt referral for intraarticular steroid treatment in the acute phase improves response. Skin changes often occur at the injection site, and specific precautions should be employed to reduce this risk. Prospective study is indicated to determine the most effective treatment strategy to prevent long-term pain and disability.

Cutting Balloon Angioplasty in Children with Resistant Renal Artery Stenosis

Children with systemic hypertension resulting from a renovascular stenosis commonly have fibromuscular dysplasia and respond to percutaneous transluminal renal angioplasty (PTRA). There is a subset of children, however, with conditions that appear to be resistant to PTRA (eg, syndromic renal artery stenosis and arteritis). These patients are often treated surgically. The development of the cutting balloon may provide a minimally invasive alternative to surgery in these individuals. Associated adverse events may include recurrent stenosis, arterial occlusion with renal loss, and arterial rupture with extravasation and pseudoaneurysm formation. Some of these adverse events can be successfully treated with percutaneous interventional techniques. The authors present four cases of cutting balloon angioplasty performed at two large metropolitan children's hospitals in children with resistant renal artery stenosis.

Reactive arthritis of the temporomandibular joints and cervical spine in a child

BACKGROUND

Temporomandibular joint (TMJ) arthritis is frequently seen in children with chronic arthritis. It has rarely been described in a non-infectious acute setting. We report a case of reactive arthritis isolated to the TMJs and cervical spine.

CASE PRESENTATION

A 6-year-old Native American boy hospitalized for treatment of lymphadenitis and aseptic meningitis had an incidental brain magnetic resonance imaging (MRI) finding of effusions in the TMJs, as well as the atlanto-occipital and C1-C2 articulations. Repeat TMJ and cervical spine MRI four weeks later showed resolution of effusions. Reactive TMJ arthritis has been previously reported in adults but not in children.

CONCLUSION

This report represents the first pediatric case of reactive arthritis isolated to the cervical spine and TMJs. Arthritis of the TMJ should be considered in the differential diagnosis of children with reactive arthritides.

CT-Guided Percutaneous Steroid Injection for Management of Inflammatory Arthropathy of the Temporomandibular Joint in Children

OBJECTIVE

The purposes of this study were to retrospectively review an injection technique, to develop a grading system for evaluation of imaging findings, and to report preliminary outcome related to percutaneous CT-guided steroid injection into the temporomandibular joints of children with inflammatory arthropathy.

CONCLUSION

CT-guided steroid injection into the temporomandibular joint of children with inflammatory arthropathy results in clinical and imaging improvement in a substantial proportion of children treated.

Interventional radiology: a modular approach

The authors offer a modular approach to the development of new procedures in the field of pediatric interventional radiology as a conceptual model and a springboard for further discussion.

Pseudoaneurysm in children: diagnosis and interventional management

Pseudoaneurysms (PAn) are uncommon in adults and even less common in children. They are most often encountered after iatrogenic arterial injury. Presentation may be substantially delayed after the iatrogenic event, and diagnosis can be difficult, especially when the PAn occurs in an unexpected location. Treatment of PAn has evolved during the last two decades from a reliance on surgical resection to US-guided compression, coil embolization, covered stents, and stent-graft exclusion. More recently, direct percutaneous US-guided thrombin injection has been used in the treatment of PAn. We present three cases of successful PAn thrombosis by US-guided percutaneous thrombin injection in children, one of the epigastric artery and two of the femoral artery.

Transgluteal Approach for Draining Pelvic Fluid Collections in Pediatric Patients

PURPOSE

To evaluate a transgluteal approach for draining pelvic fluid collections in pediatric patients.

MATERIALS AND METHODS

Institutional review board approval and informed consent for interventional procedures were obtained. From September 1995 to December 2002, 140 abdominopelvic fluid collections were drained at two institutions. Retrospective analysis of a prospectively gathered procedural database revealed that a transgluteal approach was used to drain 53 of these 140 collections (38%) in 51 patients (29 female, 22 male; mean age, 11.2 years; age range, 0.2-19 years). All patients received antibiotics before the procedure. A retrospective analysis was conducted of the patients' medical records and diagnostic imaging and interventional procedure findings, including the reason for referral; location, volume, and character of collections; method and equipment used for evacuation; duration of therapy; evidence of complications; results of microbiologic examination of specimens; and success rates.

RESULTS

Transgluteal drainage was performed with computed tomographic (CT) guidance in 45 of the 53 collections (85%), with fluoroscopic guidance in three (6%), and with a combination of both modalities in five (9%). A drainage catheter was successfully placed in 49 collections; four small collections were aspirated without drain placement. Infected fluid was obtained from 41 collections, and serosanguineous fluid was obtained from 12 collections. The mean volume aspirated was 80 mL (2-600 mL). A positive culture was obtained at 28 of the 53 procedures. The mean duration of catheter placement was 4 days (range, 2-14 days). There were no major complications.

CONCLUSION

The transgluteal approach to the drainage of abdominopelvic fluid collections with imaging guidance is safe and effective.

Utility of corticosteroid injection for temporomandibular arthritis in children with juvenile idiopathic arthritis

OBJECTIVE

To assess the effects of computed tomography (CT)-guided injection of corticosteroid into the temporomandibular joint (TMJ) in children with juvenile idiopathic arthritis (JIA) and clinical and magnetic resonance imaging (MRI) evidence of TMJ inflammation.

METHODS

Twenty-three children ages 4-16 years with JIA and MRI evidence of TMJ inflammation received CT-guided TMJ injections of corticosteroid (triamcinolone acetonide [n = 16] or triamcinolone hexacetonide [n = 7]). Jaw pain or dysfunction and maximal incisal opening (MIO) distance were assessed before and after injection. Fourteen patients had followup MRI studies of the TMJ 6-12 months after injection.

RESULTS

Of the 13 patients with symptoms of jaw pain prior to corticosteroid treatment, 10 (77%) had complete resolution of pain (P < 0.05). Prior to corticosteroid injection, MIO in all 23 patients was below age-matched normal values. After injection, the MIO was improved by at least 0.5 cm in 10 patients (43%) (P = 0.0017). Patients under 6 years of age at the time of injection showed the best response, with a postinjection MIO similar to that in age-matched controls (P = 0.2267). There was involvement of 23 TMJs in the 14 patients who had followup MRI studies; resolution of effusions was observed in 11 (48%) of the TMJs. Other than short-term facial swelling in 2 patients, there were no side effects.

CONCLUSION

The majority of children with symptomatic TMJ arthritis improved after intraarticular corticosteroid injection. Approximately half the patients experienced significant improvement in MIO and TMJ effusion. These data suggest that corticosteroid injection may be a useful procedure for the prevention and treatment of morbidities associated with TMJ arthritis in JIA.

Oral and intravenous caffeine for treatment of children with post-sedation paradoxical hyperactivity

BACKGROUND

Paradoxical hyperactivity (PH) is a known complication of sedation in children, especially with barbiturates such as pentobarbital. The accompanying inconsolable irritability and agitation, similar to behaviors reported in children with attention deficit hyperactivity disorder (ADHD), is uncomfortable for the child and anxiety-provoking for parents and health-care workers. Our objective was to describe our experience with oral (PO) and intravenous (IV) caffeine as a treatment for sedation-induced PH.

MATERIALS AND METHODS

From January 2000 to April 2003, 19,894 children were sedated in our institution for radiology procedures. Of these, 360 children were diagnosed with PH. A total of 229 children exhibiting symptoms of PH after sedative administration were treated with PO caffeine ( n=88; 43 boys, 45 girls; mean age 4.5 years, mean weight 18.7 kg) or IV caffeine ( n=131; 73 boys, 58 girls; mean age 4.8 years, mean weight 20.1 kg) or both ( n=10; 8 boys, 2 girls; mean age 5.0 years, mean weight 19.9 kg). A positive effect was defined as a decrease in agitation, crying, or hyperactivity within 40 min of caffeine administration. A control group ( n=45) was obtained from those 141 children who experienced post-sedation PH but were not treated with caffeine, and matched for age and sex with samples of children treated with IV caffeine ( n=45) and PO caffeine ( n=45).

RESULTS

Children treated intravenously received the equivalent of 20 mg/kg caffeine citrate (to a maximum of 200 mg). Of those treated with IV caffeine, 82/131 (63%) showed a positive effect, and returned to baseline behavioral status after an average of 33 min (SD=23 min). The untreated control group required a significantly longer time to recover ( P<0.01) than those treated with IV caffeine. Children treated orally received approximately 1.0-2.5 mg/kg caffeine in Mountain Dew (Pepsi-Cola Company), and 36/88 (41%) showed a positive effect and returned to baseline behavioral status after an average of 42 min (SD=27 min). Of the 10 children treated with both PO and IV caffeine, 6 showed a positive effect. There was no significant difference in recovery time between the untreated control group and either the matched orally treated group or the group treated with both IV and PO caffeine. No complications occurred after caffeine administration.

CONCLUSION

IV caffeine appears to be an effective treatment for PH in children with sedation-induced PH. Further controlled prospective study is needed to determine the optimum dose and route of administration and to compare efficacy with other potential drug classes.

Closed reduction with CT-guided screw fixation for unstable sacroiliac joint fracture-dislocation

BACKGROUND

Unstable posterior pelvic ring fractures and dislocations are uncommon but potentially life-threatening injuries in children. Early definitive management reduces risk of immediate complications as well as chronic pain and gait dysfunction. Conventional operative therapy carries substantial risk of extensive blood loss and iatrogenic neurological and vascular injury. Minimally invasive image-guided intervention may further reduce immediate risk and improve long-term outcome.

OBJECTIVE

To describe CT-guided closed reduction and internal fixation (CRIF) and review outcomes of unstable fracture-dislocation of the sacroiliac (SI) joint in children.

MATERIALS AND METHODS

Between 2000 and 2003, three children (two girls, one boy) age 8-14 years were referred to interventional radiology for treatment of unstable SI joint fracture-dislocation not adequately treated with anterior external fixation alone.

RESULTS

The three affected SI joints (two left, one right) were treated in a combined approach by pediatric interventional radiologists and orthopedic surgeons, using a percutaneous approach under CT guidance. Over a threaded guiding pin, 7.3 mm cannulated screws were used to achieve stable reduction of the affected SI joints. One screw was removed after slight (2 mm) migration. No neurovascular or other complications occurred. All patients had satisfactory healing with near-anatomic reduction, although recovery of the youngest was delayed by associated spinal injury.

CONCLUSIONS

Compared to open surgical alternatives, CRIF under CT guidance reduces operating time, decreases blood loss, and allows early definitive fixation and immediate non-weight-bearing mobilization with a low rate of complication for unstable posterior pelvic ring fractures. In addition, CT-guided placement of the guide pin may allow safer screw positioning and may minimize the total number of screws needed to achieve pelvic stability.

CT-guided Percutaneous Lung Biopsy in Children

PURPOSE

To describe techniques and evaluate outcomes of computed tomography (CT)-guided percutaneous lung biopsy in children.

MATERIALS AND METHODS

Between April 1992 and June 2003, 64 patients (32 male, 32 female) with a mean age of 10.8 years (0.6-20 years) were referred for 75 lung biopsies. Most biopsies were performed for suspected malignancy (n = 24; 32%) or to distinguish posttransplantation lymphoproliferative disorder from fungal infection in immunocompromised patients (n = 17; 23%). All children referred to the pediatric interventionalists in two children's hospitals for CT-guided biopsy of parenchymal or pleural-based lesions in the thorax were studied. Prospectively gathered procedural data were reviewed for medical history and indications for procedure, admission status, type of anesthesia, technical approach (core vs aspiration biopsy), procedural modifications, lesion size, number of passes required, and immediate complications. Medical records were retrospectively reviewed for diagnostic outcome, impact on patient management, and delayed complications.

RESULTS

Procedures were performed under deep sedation whenever possible (n = 61; 81%) with use of a coaxial core biopsy technique (n = 56; 75%), a fine needle aspiration biopsy technique (n = 15; 20%), or both (n = 4; 5%). Mean lesion diameters were 2.5 cm (range, 1-10 cm) in the core biopsy group and 1.0 cm (range, 0.5-1.7 cm) in the aspiration biopsy group. Sixty-four biopsies (85%) were diagnostic. There was one major complication (1.3%), a tension pneumothorax treated with intraprocedural placement of a chest tube.

CONCLUSION

Percutaneous CT-guided lung biopsy is a safe and accurate diagnostic procedure in children that obviates open surgical biopsy in most patients.

Transmural migration of gastrostomy tube retention discs

BACKGROUND

Accidental dislodgment is one of the most frequent causes of avoidable cost and consternation related to gastrostomy tubes. The Sacks-Vine gastrostomy tube, inserted in an antegrade fashion by a percutaneous technique, is extremely stable due to the construction of its disc retention device. However, transmural migration of the retention disc is a known severe delayed complication associated with this tube.

OBJECTIVE

To review the presentation, diagnosis, and treatment of transmural migration of gastrostomy retention discs, to propose a mechanism for the progressive development of this complication, and to recommend a method for preventing its occurrence.

MATERIALS AND METHODS

From January 1991 to October 1999, pediatric interventional radiologists at two children's hospitals performed 300 antegrade gastrostomy and gastrojejunostomy primary insertion procedures. A "push-pull" variation of the antegrade approach used for 44 of these insertions is excluded from further analysis. Of the remaining 256 procedures, 5 boys and 3 girls with a mean age of 5.1 years (range 0.8-19 years) were identified from review of the prospectively gathered procedural database with significant complications related to the disc retention component of their gastrostomy tubes. A retrospective analysis was conducted of their medical records, diagnostic imaging, and interventional and surgical findings.

RESULTS

Transmural migration was diagnosed on average 36 months after insertion (16-48 months). The diagnosis was made incidentally during endoscopy (n=1) or fluoroscopy (n=5) in six asymptomatic patients, and during barium enema to explore feculent vomiting and halitosis in two symptomatic patients. Migration of the retention disc fell along a continuum from intramural (n=4) to transmural and intracolonic (n=4), with gastric mucosal erosion, extensive granulation and inflammation in all eight patients. Although there was no evidence of free air in any patient, a gastrocolic fistula was demonstrated in four patients and a gastrocolocutaneous fistula in two of four patients with complete transmural migration. Surgical resection of the disc, gastrostomy, and fistula repair if needed was successfully performed in all patients.

CONCLUSIONS

Gastrostomy tubes with an internal retention disc are at risk for progressive disc migration into and through the gastric wall, resulting in irretrievable fixation and potential fistula formation. This severe delayed complication results from prolonged traction on the retention disc. Transmural migration may be avoided through improved tube care education, daily disc mobilization, and earlier disc retrieval.

Development of catheter-based procedures for transducing the isolated rabbit liver with plasmid DNA

Rapid systemic injection of naked plasmid DNA (pDNA) in a large volume into a mouse tail vein has been shown to result in a high level of gene expression in the liver. However, the potential therapeutic benefit to humans embodied in hydrodynamic transfection of the liver cannot be realized until a clinically viable method for gene delivery is developed. In light of this fact, we have devised and evaluated several methods for delivering pDNA to the isolated rabbit liver using minimally invasive catheter-based techniques. Using a lobar technique, pDNA was delivered hydrodynamically to an isolated hepatic lobe using a balloon occlusion balloon catheter to occlude a selected hepatic vein. A whole organ technique was used wherein the entire hepatic venous system was isolated and the pDNA solution injected hydrodynamically into the vena cava between two balloons used to block hepatic venous outflow. Lobar delivery of a plasmid encoding a secreted alkaline phosphatase (SEAP) reporter gene resulted in significant levels of transgene product in the serum. A nonsecreted transgene product, chloramphenicol acetyltransferase (CAT), showed the highest levels of expression in the injected lobe distal to the injection site. Compared to lobar delivery, whole organ delivery yielded much higher serum levels of SEAP expression and a significantly broader hepatic parenchymal distribution of CAT expression. These preliminary studies suggest that catheter-mediated hydrodynamic delivery of pDNA to the isolated liver may provide a method for human gene therapy that is both therapeutically significant and clinically practicable.

US-guided core biopsy of the spleen in children

PURPOSE

To evaluate the safety, diagnostic yield, and clinical benefits of performing ultrasonography (US)-guided percutaneous splenic core biopsy in children.

MATERIALS AND METHODS

US-guided splenic core biopsy was performed in 30 children aged 6 months to 15.3 years (mean, 7.0 years), with focal lesions in 27 patients and homogeneous splenomegaly in three. Four patients underwent repeat biopsy to identify changes in splenic disease. Four types of biopsy needles were used in this series. General anaesthesia was used in 21 patients and conscious sedation in nine. Medical records were reviewed to assess diagnostic accuracy, influence on treatment, and biopsy-related complications.

RESULTS

All biopsies were performed without complication. Among the 30 biopsies, an accurate diagnosis was obtained in 25 (83%), a false-negative result was obtained in two (7%), and three (10%) were nondiagnostic. All conclusive results influenced treatment decisions. The mean number of needle passes was 2.7 per patient (range, 2-5 passes). Use of needles was 50%-100% successful in the acquisition of adequate tissue cores. Use of the 18-gauge needle was always successful in the safe acquisition of adequate tissue, with a maximum of three passes.

CONCLUSION

US-guided splenic core biopsy is a minimally invasive, simple, and safe procedure for use in children. It provides relatively high diagnostic accuracy while minimizing complications when compared with alternative, more invasive procedures.