Proposal of a New Adverse Event Classification by the Society of Interventional Radiology Standards of Practice Committee.

PURPOSE: To develop a new adverse event (AE) classification for the interventional radiology (IR) procedures and evaluate its clinical, research, and educational value compared with the existing Society of Interventional Radiology (SIR) classification via an SIR member survey. MATERIALS AND METHODS: A new AE classification was developed by members of the Standards of Practice Committee of the SIR. Subsequently, a survey was created by a group of 18 members from the SIR Standards of Practice Committee and Service Lines. Twelve clinical AE case scenarios were generated that encompassed a broad spectrum of IR procedures and potential AEs. Survey questions were designed to evaluate the following domains: educational and research values, accountability for intraprocedural challenges, consistency of AE reporting, unambiguity, and potential for incorporation into existing quality-assurance framework. For each AE scenario, the survey participants were instructed to answer questions about the proposed and existing SIR classifications. SIR members were invited via online survey links, and 68 members participated among 140 surveyed. Answers on new and existing classifications were evaluated and compared statistically. Overall comparison between the two surveys was performed by generalized linear modeling. RESULTS: The proposed AE classification received superior evaluations in terms of consistency of reporting (P < .05) and potential for incorporation into existing quality-assurance framework (P < .05). Respondents gave a higher overall rating to the educational and research value of the new compared with the existing classification (P < .05). CONCLUSIONS: This study proposed an AE classification system that outperformed the existing SIR classification in the studied domains.

Image-guided intrathymic injection of multipotent stem cells supports lifelong T-cell immunity and facilitates targeted immunotherapy.

T-cell deficiency related to disease, medical treatment, or aging represents a major clinical challenge and is associated with significant morbidity and mortality in cancer and bone marrow transplantation recipients. This study describes several innovative and clinically relevant strategies to manipulate thymic function based on an interventional radiology technique for intrathymic injection of cells or drugs. We show that intrathymic injection of multipotent hematopoietic stem/progenitor cells into irradiated syngeneic or allogeneic young or aged recipients resulted in efficient and long-lasting generation of functional donor T cells. Persistence of intrathymic donor cells was associated with intrathymic presence of cells resembling long-term hematopoietic stem cells, suggesting a self-renewal capacity of the intrathymically injected cells. Furthermore, our approach enabled the induction of long-term antigen-specific T-cell-mediated antitumor immunity following intrathymic injection of progenitor cells harboring a transgenic T-cell receptor gene. The intrathymic injection of interleukin-7 prior to irradiation conferred radioprotection. In addition, thymopoiesis of aged mice improved with a single intrathymic administration of low-dose keratinocyte growth factor, an effect that was sustained even in the setting of radiation-induced injury. Taken together, we established a preclinical framework for the development of novel clinical protocols to establish lifelong antigen-specific T-cell immunity.

Patient perspectives and preferences for communication of medical imaging risks in a cancer care setting.

PURPOSE: To identify opportunities for improving patient-centered communication about diagnostic imaging tests that involve the use of radiation in a cancer care setting. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Patient knowledge, information sources, and communication preferences were assessed in six focus groups during 2012. The groups consisted of patients undergoing treatment for metastatic colorectal carcinoma, women treated within the past 6 months for early-stage breast carcinoma, men undergoing surveillance after testicular cancer treatment, parents of patients treated for stage I-III neuroblastoma, patients in a thoracic oncology survivorship program, and participants in a lung cancer screening program. A multidisciplinary research team performed thematic content analysis of focus group transcripts. High-level findings were summarized during consensus conferences. RESULTS: Although they were aware of the long-term risk of cancer from exposure to ionizing radiation, most participants reported that their health care provider did not initiate discussion about benefits and risks of radiation from imaging tests. Most patients obtained information by means of self-directed internet searches. Participants expressed gratitude for tests ("That CT saved my daughter's life," "I'd rather have the radiation dosage than being opened up"), yet they expressed concern about having to initiate discussions ("If you don't ask, nobody is going to tell you anything") and the desire to be offered information concerning the rationale for ordering specific imaging examinations, intervals for follow-up imaging, and testing alternatives. Participants believed that such information should be available routinely and that conversation with their personal physician or endorsed, readily available reference materials were ideal methods for information exchange. Understanding imaging radiation risks and active participation in decision making about imaging were especially important to cancer survivors. CONCLUSION: A substantial gap exists between patient expectations and current practices for providing information about medical imaging tests that involve the use of radiation.

Safety and efficacy of percutaneous cecostomy/colostomy for treatment of large bowel obstruction in adults with cancer.

PURPOSE: To assess the safety and efficacy of image-guided percutaneous cecostomy/colostomy (PC) in the management of colonic obstruction in patients with cancer. MATERIALS AND METHODS: Twenty-seven consecutive patients underwent image-guided PC to relieve large bowel obstruction at a single institution between 2000 and 2012. Colonic obstruction was the common indication. Patient demographics, diagnosis, procedural details, and outcomes including maximum colonic distension (MCD; ie, greatest transverse measurement of the colon on radiograph or scout computed tomography image) were recorded and retrospectively analyzed. RESULTS: Following PC, no patient experienced colonic perforation; pain was relieved in 24 of 27 patients (89%). Catheters with tip position in luminal gas rather than mixed stool/gas or stool were associated with greater decrease in MCD (-40%, -12%, and -16%, respectively), with the difference reaching statistical significance (P = .002 and P = .013, respectively). Catheter size was not associated with change in MCD (P = .978). Catheters were successfully removed from six of nine patients (67%) with functional obstructions and two of 18 patients (11%) with mechanical obstructions. One patient underwent endoscopic stent placement after catheter removal. Three patients required diverting colostomy after PC, and their catheters were removed at the time of surgery. One major complication (3.7%; subcutaneous emphysema, pneumomediastinum, and sepsis) occurred 8 days after PC and was successfully treated with cecostomy exchange, soft-tissue drainage, and intravenous antibiotic therapy. CONCLUSIONS: Image-guided PC is safe and effective for management of functional and mechanical bowel obstruction in patients with cancer. For optimal efficacy, catheters should terminate within luminal gas.

Radiofrequency ablation of T1 lung carcinoma: comparison of outcomes for first primary, metachronous, and synchronous lung tumors.

PURPOSE: To report and compare outcomes after radiofrequency ablation for treatment-naïve first primary, metachronous, and synchronous T1 lung tumors. MATERIALS AND METHODS: This institutional review board-approved retrospective study reviewed 29 patients (12 men and 17 women; median age, 73 y; age range, 55-86 y) with treatment-naïve T1 lung tumors treated with radiofrequency ablation. Tumors in the 29 patients included 21 T1a and 8 T1b first primary (n = 11), metachronous (n = 14), or synchronous (n = 4) tumors (adenocarcinoma, n = 25; squamous cell carcinoma, n = 3; unspecified, n = 1). Median tumor diameter was 14 mm (range, 10-26 mm). Surveillance computed tomography or positron emission tomography-computed tomography was performed over a median period of 28 months (range, 12-83 mo). Technical success and effectiveness rates and overall and progression-free 1-year, 3-year, and 5-year survivals were calculated according to stage, first primary, metachronous, and synchronous tumor status. RESULTS: Technical success and effectiveness was 97%. Local control occurred in 17 of 21 T1a tumors (81%) and 5 of 8 T1b tumors (62.5%). The local progression rate of first primary tumors (5 of 11; 45%) was higher than that of metachronous (2 of 14; 14%; P = .07) and synchronous (0 of 4; P = .01) tumors. Estimated 1-year, 3-year, and 5-year local tumor progression-free survival was 79%, 75%, and 75%. Estimated 1-year, 3-year, and 5-year overall survival was 100%, 60%, and 14%. Survival outcomes were similar for patients with first primary, metachronous, or synchronous tumors. CONCLUSIONS: Radiofrequency ablation results in good local control and progression-free survival in patients with treatment-naïve T1 lung tumors, including patients with metachronous and synchronous tumors.

Factors affecting periprocedural morbidity and mortality and long-term patient survival after arterial embolization of hepatic neuroendocrine metastases.

PURPOSE: To identify factors affecting periprocedural morbidity and mortality and long-term survival following hepatic artery embolization (HAE) of hepatic neuroendocrine tumor (NET) metastases. MATERIALS AND METHODS: This single-center, institutional review board-approved retrospective review included 320 consecutive HAEs for NET metastases performed in 137 patients between September 1996 and September 2007. Forty-seven HAEs (15%) were performed urgently to manage refractory symptoms in inpatients (urgent group), and 273 HAEs (85%) were elective (elective group). Overall survival (OS) was estimated by Kaplan-Meier methodology. Complications were categorized per Common Terminology Criteria for Adverse Events, version 4.0. Univariate and multivariate analyses were performed to determine independent predictors for OS, complications, and 30-day mortality. The independent factors were combined to develop clinical risk score groups. RESULTS: Urgent HAE (P = .007), greater than 50% liver replacement by tumor (P < .0001), and extrahepatic metastasis (P = .007) were independent predictors for shorter OS. Patients with all three risk factors had decreased OS versus those with none (median, 8.5 vs 86 mo; P < .001). Thirty-day mortality was significantly lower in the elective (1%) versus the urgent group (8.5%; P = .0009). There were eight complications (3%) in the elective group and five (10.6%) in the urgent group (P = .03). Male sex and urgent group were independent factors for higher 30-day mortality rate (P = .023 and P =.016, respectively) and complications (P = .012 and P =.001, respectively). CONCLUSIONS: Urgent HAE, replacement of more than 50% of liver by tumor, and extrahepatic metastasis are strong independent predictors of shorter OS. Male sex and urgent HAE carry higher 30-day mortality and periprocedural morbidity risks.

Long-term outcomes comparing surgery to embolization-ablation for treatment of solitary HCC<7 cm.

BACKGROUND: Resection has been the standard of care for patients with solitary hepatocellular carcinoma (HCC). Transarterial embolization and percutaneous ablation are alternative therapies often reserved for suboptimal surgical candidates. Here we compare long-term outcomes of patients with solitary HCC treated with resection versus combined embo-ablation. METHODS: We previously reported a retrospective comparison of resection and embo-ablation in 73 patients with solitary HCC<7 cm after a median follow-up of 23 months. This study represents long-term updated follow-up over a median of 134 months. RESULTS: There was no difference in survival among Okuda I patients who underwent resection versus embo-ablation (66 vs 58 months, p=.39). There was no difference between the groups in the rate of distant intrahepatic (p=.35) or metastatic progression (p=.48). Surgical patients experienced more complications (p=.004), longer hospitalizations (p<.001), and were more likely to require hospital readmission within 30 days of discharge (p=.03). CONCLUSION: Over a median follow up of more than 10 years, we found no significant difference in overall survival of Okuda 1 patients with solitary HCC<7 cm who underwent surgical resection versus embo-ablation. Our data suggest that there may be a greater role for primary embo-ablation in the treatment of potentially resectable solitary HCC.

Image-guided thermal ablation of tumors increases the plasma level of interleukin-6 and interleukin-10.

PURPOSE: To identify changes in plasma cytokine levels after image-guided thermal ablation of human tumors and to identify the factors that independently predict changes in plasma cytokine levels. MATERIALS AND METHODS: Whole-blood samples were collected from 36 patients at three time points: before ablation, after ablation (within 48 hours), and at follow-up (1-5 weeks after ablation). Plasma levels of interleukin (IL)-1α, IL-2, IL-6, IL-10, and tumor necrosis factor (TNF)-α were measured using a multiplex immunoassay. Univariate and multivariate analyses were performed using cytokine level as the dependent variable and sample collection, time, age, sex, primary diagnosis, metastatic status, ablation site, and ablation type as the independent variables. RESULTS: There was a significant increase in the plasma level of IL-6 after ablation compared with before ablation (9.6-fold ± 31-fold, P<.002). IL-10 also showed a significant increase after ablation (1.9-fold ± 2.8-fold, P<.02). Plasma levels of IL-1α, IL-2, and TNF-α were not significantly changed after ablation. Cryoablation resulted in the largest change in IL-6 level (>54-fold), whereas radiofrequency ablation and microwave ablation showed 3.6-fold and 3.4-fold changes, respectively. Ablation of melanomas showed the largest change in IL-6 48 hours after ablation (92×), followed by ablation of kidney (26×), liver (8×), and lung (6×) cancers. Multivariate analysis revealed that ablation type (P<.0003) and primary diagnosis (P<.03) were independent predictors of changes to IL-6 after ablation. Age was the only independent predictor of IL-10 levels after ablation (P< .019). CONCLUSIONS: Image-guided thermal ablation of tumors increases plasma levels of IL-6 and IL-10, without increasing plasma levels of IL-1α, IL-2, or TNF-α.

Outcomes of patients undergoing percutaneous biliary drainage to reduce bilirubin for administration of chemotherapy.

PURPOSE: To describe outcomes in patients undergoing percutaneous biliary drainage to reduce total serum bilirubin level for administration of chemotherapy. MATERIALS AND METHODS: A total of 647 consecutive patients underwent percutaneous biliary drainage between September 2001 and December 2008. In 168, the indication for biliary drainage was to decrease total serum bilirubin level to permit administration of chemotherapy. Of these, 20 were excluded because they had hepatic arterial infusion pumps, leaving 148 patients as the study group. The primary diagnoses for these patients were gallbladder cancer (n = 23), cholangiocarcinoma (n = 21), pancreatic cancer (n = 36), and other metastatic cancers (n = 68). Medical records and imaging studies were reviewed for demographic data, procedural information, pre- and postdrainage total serum bilirubin level levels, 30-day complications, and subsequent biliary procedures. RESULTS: The probability of attaining a total serum bilirubin level of 1 mg/dL or lower by 100 days was 31% (95% CI, 23%-39%). Predrainage total serum bilirubin level of 9 mg/dL or lower (hazard ratio [HR], 3.27; 95% CI, 1.86-5.75; P < .001), 100% liver drainage (HR 2.73, 95% CI, 1.56-4.78; P <.001), and lower predrainage International Normalized Ratio (INR; HR, 0.80; 95% CI, 0.70-0.92; P = .002) were associated with an increased likelihood of attaining a total serum bilirubin level of 1 mg/dL or lower. The most common indication for follow-up was pericatheter leakage, which occurred in nearly one third of cases. During follow-up, patients required three visits per 100 catheter-days, or approximately one per month. Median overall survival in this population was approximately 3.5 months. CONCLUSIONS: Only 31% of patients attained a normal serum bilirubin level by 100 days, and median overall survival was 107 days. Careful patient selection is warranted before biliary drainage for this indication. Maximal biliary drainage, a preprocedure total serum bilirubin of less than 9 mg/dL, and a lower INR were factors associated with serum bilirubin normalization in this cohort.

Totally implantable venous access device placement by interventional radiologists: are prophylactic antibiotics necessary?

PURPOSE: To determine the rate of early infection for totally implantable venous access devices (TIVADs) placed without antibiotic prophylaxis. MATERIAL AND METHODS: A list of patients who underwent TIVAD placement in 2009 was obtained from the patient archiving and communication system (PACS). This list was cross-referenced to all patients who underwent TIVAD removal from January 1, 2009, through January 30, 2010, to identify TIVADs that were removed within 30 days of placement. Retrospective chart review was performed to record patient demographics, including age, sex, cancer diagnosis, and indication for removal. Concurrent antibiotic therapy, chemotherapy, and laboratory data before and within 30 days of placement were recorded. Central line-associated bloodstream infections (CLABSIs) were identified using U.S. Centers for Disease Control and Prevention (CDC) criteria. RESULTS: There were 1,183 ports placed and 13 removed. CLABSIs occurred in seven (0.6%) patients within 30 days of placement. At the time of TIVAD placement, 81 (7%) patients were receiving antibiotics incidental to the procedure. One patient who received an antibiotic the day of implantation developed a CLABSI. Chemotherapy was administered to 148 (13%) patients on the day of placement. CONCLUSIONS: The rate of early infection without antibiotic prophylaxis before TIVAD placement in the interventional radiology suite is < 1%. Based on these data, use of prophylactic antibiotics for TIVAD placement is not recommended.

Recurrent non-small cell lung cancer: evaluation of CT-guided radiofrequency ablation as salvage therapy.

BACKGROUND: Radiofrequency ablation (RFA) is a potential application as a salvage tool after failure of surgery, chemotherapy, or radiotherapy of non-small cell lung cancer (NSCLC). Although several studies have evaluated the use of RFA in primary NSCLC, there is little literature on its potential application as a salvage tool. PURPOSE: To evaluate CT-guided RFA employed as a salvage therapy for pulmonary recurrences of NSCLC after prior treatment with chemotherapy, radiation therapy, and/or surgery. MATERIAL AND METHODS: A retrospective computer database search yielded 33 patients with biopsy proven primary NSCLC who underwent CT-guided RFA of 39 recurrent tumors following surgery, chemotherapy, and/or radiotherapy. Follow-up imaging was performed with CT and PET-CT. The endpoints of interest were progression-free survival (PFS) and time to local progression (TTLP). PFS and TTLP were compared by lesion size (<3 cm, ≥3 cm). RESULTS: The median PFS was 8 months. For patients with a tumor size <3 cm median PFS was 11 months, whereas the median PFS of patients with a tumor size ≥3 cm was 5 months. The difference did not reach statistical significance (P = 0.09). The median TTLP of all tumors was 14 months. TTLP of ablated tumors <3 cm in size was 24 months, compared to 8 months for ablated tumors ≥3 cm in size. The difference did not reach statistical significance (P = 0.07). CONCLUSION: RFA of recurrent NSCLC may be a valuable salvage tool to achieve local tumor control, especially in tumors measuring <3 cm in size.

Selective arterial embolization for pseudoaneurysms and arteriovenous fistula of renal artery branches following partial nephrectomy.

PURPOSE: We describe the presentation, endovascular management and functional outcomes of 15 patients with renal arterial pseudoaneurysm following open and laparoscopic partial nephrectomy. MATERIALS AND METHODS: An institutional review board approved, Health Insurance Portability and Accountability Act compliant retrospective review of a prospectively maintained database revealed that 7 of 1,160 patients who underwent open partial nephrectomy and 8 of 301 treated with laparoscopic partial nephrectomy were diagnosed with a pseudoaneurysm of a renal artery branch between 2003 and 2010. Some cases were associated with arteriovenous fistula. RESULTS: Diagnosis of pseudoaneurysm was made a median of 14 days after surgery. Gross hematuria was the most frequent symptom. Median estimated glomerular filtration rate measurements at the preoperative evaluation, postoperatively, on the day the vascular lesion was diagnosed, after embolization and at the last followup were 62, 55, 55, 56 and 58 ml/minute/1.73 m(2), respectively. Median followup was 7.8 months. All patients underwent angiography and superselective coil embolization of 1 or more pseudoaneurysms with or without arteriovenous fistula. Eleven patients had immediate cessation of symptoms while 4 had persistent gross hematuria after the procedure. Of these 4 patients 2 were treated with bedside care, 1 required repeat embolization with thrombin, which was successful, and the remaining patient had coagulopathy and underwent radical nephrectomy for persistent bleeding. CONCLUSIONS: Pseudoaneurysms and arteriovenous fistulas of the renal artery are rare complications of partial nephrectomy. Presentation is often delayed. Superselective coil embolization is a safe, minimally invasive treatment option that usually solves the clinical problem and preserves renal function.

CT-guided radiofrequency ablation as a salvage treatment of colorectal cancer hepatic metastases developing after hepatectomy.

PURPOSE: To evaluate the clinical outcomes of percutaneous radiofrequency (RF) ablation of colorectal cancer liver metastases (CLMs) that recur after hepatectomy. MATERIALS AND METHODS: From December 2002 to December 2008, 71 CLMs that developed after hepatectomy were ablated in 56 patients. Medical records and imaging were reviewed to determine technique effectiveness/complete ablation (ie, ablation defect covering the entire tumor on 4-6-week postablation computed tomography [CT]), complications, and local tumor progression (LTP) at the site of ablation. LTP-free and overall survival were calculated by using Kaplan-Meier methodology. A modified clinical risk score (CRS) including nodal status of the primary tumor, time interval between diagnoses of the primary tumor and liver metastases, number of tumors, and size of the largest tumor was assessed for its effect on overall survival and LTP. RESULTS: Tumor size ranged between 0.5 and 5.7 cm. Complete ablation was documented in 67 of 71 cases (94%). Complications included liver abscess (n = 1) and pleural effusion (n = 1). Median overall survival time was 31 months. One-, 2- and 3-year overall survival rates were 91%, 66%, and 41%, respectively. CRS was an independent factor for overall survival (74% for CRS of 0-2 vs 42% for CRS of 3-4 at 2 y; P = .03) and for LTP-free survival (66% for CRS of 0-2 vs 22% for CRS of 3-4 at 1 y after a single ablation; P <.01). CONCLUSIONS: CT-guided RF ablation can be used to treat recurrent CLM after hepatectomy. A low CRS is associated with better clinical outcomes.

Pyogenic abscess after hepatic artery embolization: a rare but potentially lethal complication.

PURPOSE: Hepatic artery embolization (HAE) is used commonly to treat liver tumors or hemorrhage. Infectious complications are rare but carry high rates of morbidity and mortality. Identification of clinical factors associated with postembolization abscess may improve management and outcome. MATERIALS AND METHODS: Clinical and pathologic variables of patients treated with HAE were collected and analyzed to determine the etiology, incidence, and outcome of pyogenic hepatic abscess. RESULTS: From January 1998 to January 2010, 971 patients underwent 2,045 HAE procedures. Fourteen patients developed a pyogenic hepatic abscess after embolization, for an overall rate of 1.4%. Thirty-four patients (4%) had a history of bilioenteric anastomosis (BEA) and 21 patients (2%) lacked a competent sphincter of Oddi because of the presence of a biliary stent (n = 19) or a previous sphincterotomy (n = 2). Eleven of the 34 patients with a BEA (33%) and two of 21 patients with an incompetent sphincter (10%) developed abscesses, in contrast to only one abscess (0.05%) among the 916 patients with apparently normal sphincters (0.1%; odds ratio, 437.6; 95% CI, 54.2-3,533; P < .0001). Gram-negative and Gram-positive aerobes were the most common bacteria isolated after drainage. Percutaneous drainage was the initial management strategy in all patients; two patients (14%) required subsequent surgical drainage and hepatectomy, and three (21%) died. CONCLUSIONS: Pyogenic hepatic abscess is rare after HAE. A history of BEA or an incompetent sphincter of Oddi caused by a biliary stent or previous sphincterotomy substantially increases the likelihood of this highly morbid and potentially fatal complication.

Analysis and prioritization of near-miss adverse events in a radiology department.

OBJECTIVE: The purpose of this study is to describe a method for the evaluation and prioritization of near-miss events in a radiology department. MATERIALS AND METHODS: Sixty-two consecutive near-miss events occurring between 2007 and 2009 were retrospectively evaluated, classified by error type, and scored for five elements associated with risk. The worst outcome potentially associated with each event was predicted by consensus and scored on a standardized 5-point complications grading scale. Scores were then assigned for event frequency, method of detection, barrier number, and quality. The product of individual scores, ranging from 1 to 180, was termed the hazard score. Events were analyzed by error type, element scores, and hazard score. RESULTS: Electronic order entry errors were the most common error type, and 90% of these errors originated outside the radiology department. More than half (65%) of the events were assigned maximal severity scores, and 68% of the errors had been encountered three or more times previously. Twenty-five events (40%) were detected by good fortune rather than by plan. No barrier to the projected worst outcome was identified in nearly half (47%) of cases. In most instances (73%), strong barriers were absent. Nine events (15%) had maximal hazard scores of 180, whereas 21 events (34%) had hazard scores of 30 or less. CONCLUSION: This method was constructed from standardized definitions of outcome severity, the ability of current systems to detect or mitigate an adverse event or outcome, and event frequency and offers a tool for systematic evaluation and stratification of near-miss adverse events.

Enhancing the case log by coding the level of trainee participation in vascular interventional radiology procedures.

OBJECTIVE: The purpose of this article is to describe a new method for coding trainee participation in vascular interventional radiology procedures. MATERIALS AND METHODS: From July 2008 through June 2009, all interventional radiology fellows maintained an enhanced case log at our institution; 748 unique cases were logged by procedure type, supervising physician, and level of participation in the case. Level of participation was classified on a 5-point scale that included designations for observation, first assistant, performance of basic techniques, performance of advanced techniques, and primary operation. Descriptive statistics of participation scores were calculated for each quarter and were analyzed by procedure type and by teaching faculty member. RESULTS: As expected, analysis by procedure type showed that average participation scores increased from one quarter to the next in most cases. By the fourth quarter, the modal participation score was 5, indicating primary operation or performance of multiple critical steps. Analysis by teaching faculty member revealed three patterns: those attending physicians facilitating increasing levels of participation in every quarter, those facilitating maximal growth within the first 6 months, and those with irregular trainee participation profiles. CONCLUSION: Data from a 5-point participation scale add information to the procedure case log that could be used to quantitatively track the technical progress of trainees while providing education quality feedback to both teaching physicians and program directors.

Catheter-free survival after primary percutaneous stenting of malignant bile duct obstruction.

OBJECTIVE: The purpose of this article is to review the outcomes of patients with malignant biliary obstruction treated by immediate placement of a metallic stent at the time of percutaneous biliary drainage. MATERIALS AND METHODS: By a search of our PACS, we retrospectively identified all patients who underwent biliary stent placement at our interventional radiology section between January 2003 and December 2008. Of 564 biliary stent procedures, 71 primary percutaneous stents were placed at the time of biliary drainage; the other 493 were secondary percutaneous stents, placed at various durations after biliary drainage. Medical records and procedure reports were reviewed for the primary percutaneous stent group recording time to removal of the percutaneous catheter, periprocedural complications, subsequent biliary interventions, overall survival, and catheter-free survival. RESULTS: After placement of primary percutaneous stents, 97% of patients were able to have their transhepatic catheter removed, and in 73% of patients, this 5-French catheter was removed within 24 hours. Major complications after placement of primary percutaneous stents included bile peritonitis requiring IV analgesia for less than 48 hours (5.6%) and fever with leukocytosis treated with IV antibiotics (8.5%) for 48-72 hours. Median overall survival was 165 days, and 90% of patients had 100% catheter-free survival. Overall, 94% of survival days were catheter free. CONCLUSION: Placement of primary percutaneous stents when clinically appropriate has the advantage of avoiding an externalized drainage catheter and its attendant lifestyle limitations and complications. Most patients with malignant biliary obstruction, for whom expected survival is short, will experience 100% catheter-free survival after placement of a primary percutaneous stent.

Fears, feelings, and facts: interactively communicating benefits and risks of medical radiation with patients.

OBJECTIVE: As public awareness of medical radiation exposure increases, there has been heightened awareness among patients and physicians of the importance of holistic benefit-and-risk discussions in shared medical decision making. CONCLUSION: We examine the rationale for informed consent and risk communication, draw on the literature on the psychology of radiation risk communication to increase understanding, examine methods commonly used to communicate radiation risk, and suggest strategies for improving communication about medical radiation benefits and risk.

Irreversible electroporation near the heart: ventricular arrhythmias can be prevented with ECG synchronization.

OBJECTIVE: Irreversible electroporation is a nonthermal ablative tool that uses direct electrical pulses to create irreversible membrane pores and cell death. The ablation zone is surrounded by a zone of reversibly increased permeability; either zone can cause cardiac arrhythmias. Our purpose was to establish a safety profile for the use of irreversible electroporation close to the heart. MATERIALS AND METHODS: The effect of unsynchronized and synchronized (with the R wave on ECG) irreversible electroporation in swine lung and myocardium was studied in 11 pigs. Twelve lead ECG recordings were analyzed by an electrophysiologist for the presence of arrhythmia. Ventricular arrhythmias were categorized as major events. Minor events included all other dysrhythmias or ECG changes. Cardiac and lung tissue was submitted for histopathologic analysis. Electrical field modeling was performed to predict the distance from the applicators over which cells show electroporation-induced increased permeability. RESULTS: At less than or equal to 1.7 cm from the heart, fatal (major) events occurred with all unsynchronized irreversible electroporation. No major and three minor events were seen with synchronized irreversible electroporation. At more than 1.7 cm from the heart, two minor events occurred with only unsynchronized irreversible electroporation. Electrical field modeling correlates well with the clinical results, revealing increased cell membrane permeability up to 1.7 cm away from the applicators. Complete lung ablation without intervening live cells was seen. No myocardial injury was seen. CONCLUSION: Unsynchronized irreversible electroporation close to the heart can cause fatal ventricular arrhythmias. Synchronizing irreversible electroporation pulse delivery with absolute refractory period avoids significant cardiac arrhythmias.