E-cigarettes and arrhythmogenesis: a comprehensive review of pre-clinical studies and their clinical implications.

Electronic cigarette use has grown exponentially in recent years, and while their popularity has increased, the long-term effects on the heart are yet to be fully studied and understood. Originally designed as devices to assist with those trying to quit traditional combustible cigarette use, their popularity has attracted use by teens and adolescents who traditionally have not smoked combustible cigarettes. Acute effects on the heart have been shown to be similar to traditional combustible cigarettes, including increased heart rate and blood pressure. The main components of electronic cigarettes that contribute to these arrhythmic effects are found in the e-liquid that is aerosolized and inhaled, comprised of nicotine, flavourings, and a combination of vegetable glycerin (VG) and propylene glycol (PG). Nicotine can potentially induce both ventricular and atrial arrhythmogenesis, with both the atrial and ventricular effects resulting from the interactions of nicotine and the catecholamines they release via potassium channels. Atrial arrhythmogenesis, more specifically atrial fibrillation, can also occur due to structural alterations, which happens because of nicotine downregulating microRNAs 133 and 590, both post-transcriptional growth factor repressors. Liquid flavourings and the combination of PG and VG can possibly lead to arrhythmic events by exposing users to acrolein, an aldehyde that stimulates TRPA1 that in turn causes a change towards sympathetic activation and autonomic imbalance. The design of these electronic delivery devices is constantly changing; therefore, it has proven extremely difficult to study the long-term effects on the heart caused by electronic cigarettes but will be important to understand given their rising popularity. The arrhythmic effects of electronic cigarettes appear similar to traditional cigarettes as well; however, a comprehensive review has not been compiled and is the focus of this article.

Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes.

Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder characterized by fibro-fatty infiltration with an increased propensity for ventricular arrhythmias and sudden death. Genetic variants in desmosomal genes are associated with ACM. Incomplete penetrance is a common feature in ACM families, complicating the understanding of how external stressors contribute towards disease development. To analyze the dual role of genetics and external stressors on ACM progression, we developed one of the first mouse models of ACM that recapitulates a human variant by introducing the murine equivalent of the human R451G variant into endogenous desmoplakin (DspR451G/+). Mice homozygous for this variant displayed embryonic lethality. While DspR451G/+ mice were viable with reduced expression of DSP, no presentable arrhythmogenic or structural phenotypes were identified at baseline. However, increased afterload resulted in reduced cardiac performance, increased chamber dilation, and accelerated progression to heart failure. In addition, following catecholaminergic challenge, DspR451G/+ mice displayed frequent and prolonged arrhythmic events. Finally, aberrant localization of connexin-43 was noted in the DspR451G/+ mice at baseline, becoming more apparent following cardiac stress via pressure overload. In summary, cardiovascular stress is a key trigger for unmasking both electrical and structural phenotypes in one of the first humanized ACM mouse models.

Arrhythmogenic Cardiomyopathy: Molecular Insights for Improved Therapeutic Design.

Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder characterized by structural and electrical cardiac abnormalities, including myocardial fibro-fatty replacement. Its pathological ventricular substrate predisposes subjects to an increased risk of sudden cardiac death (SCD). ACM is a notorious cause of SCD in young athletes, and exercise has been documented to accelerate its progression. Although the genetic culprits are not exclusively limited to the intercalated disc, the majority of ACM-linked variants reside within desmosomal genes and are transmitted via Mendelian inheritance patterns; however, penetrance is highly variable. Its natural history features an initial "concealed phase" that results in patients being vulnerable to malignant arrhythmias prior to the onset of structural changes. Lack of effective therapies that target its pathophysiology renders management of patients challenging due to its progressive nature, and has highlighted a critical need to improve our understanding of its underlying mechanistic basis. In vitro and in vivo studies have begun to unravel the molecular consequences associated with disease causing variants, including altered Wnt/ß-catenin signaling. Characterization of ACM mouse models has facilitated the evaluation of new therapeutic approaches. Improved molecular insight into the condition promises to usher in novel forms of therapy that will lead to improved care at the clinical bedside.

Portomesenteric Venous Stenting for Palliation of Ascites and Variceal Bleeding Caused by Prehepatic Portal Hypertension.

BACKGROUND: The purpose of this study was to evaluate percutaneous transhepatic portal vein stenting (PVS) for palliation of refractory ascites and/or variceal bleeding caused by extrahepatic portomesenteric venous stenosis in patients with pancreaticobiliary cancer. MATERIALS AND METHODS: A single-institution, retrospective review of patients who underwent PVS between January 2007 and July 2015 was performed. A total of 38 patients were identified, of whom 28 met the inclusion criterion of PVS performed primarily for refractory ascites or variceal bleeding. In addition to technical success and overall survival, clinical success was measured by fraction of remaining life palliated. The palliative effect of PVS was also quantified by measuring changes in liver and ascites volumes after the procedure. RESULTS: Technical success was 93% (26/28). Stent deployment involved more than one portomesenteric vessel in most patients (20/26). The cumulative probability of symptom recurrence at 6, 12, 18, and 24 months was 12%, 16%, 26%, and 40%, respectively. There was a significant difference (p < .001) in the probability of symptom recurrence, recurrence of abdominal ascites, and increase in liver volume between patients whose stents remained patent and those whose stents demonstrated partial or complete occlusion. The mean fraction of remaining life palliated was 87%. All but two patients were found to have improvement in clinical symptoms for the majority of their lives after the procedure. There were no major or minor complications. CONCLUSION: As a low-risk procedure with a high clinical success rate, PVS can play a substantial role in improving quality of life in patients with portomesenteric stenoses. IMPLICATIONS FOR PRACTICE: Portomesenteric venous stenosis is a challenging complication of pancreaticobiliary malignancy. Portomesenteric stenoses can lead to esophageal, gastric, and mesenteric variceal bleeding, as well as abdominal ascites. The purpose of this study was to evaluate the safety and efficacy of portal vein stenting (PVS) in patients with cancer who have symptomatic portal hypertension caused by portomesenteric venous compression. As a low-risk procedure with a high clinical success rate, PVS can play a substantial role in improving quality of life in patients with portomesenteric stenoses.

Characteristics of percutaneous core biopsies adequate for next generation genomic sequencing.

PURPOSE: Determine the characteristics of percutaneous core biopsies that are adequate for a next generation sequencing (NGS) genomic panel. MATERIALS AND METHODS: All patients undergoing percutaneous core biopsies in interventional radiology (IR) with samples evaluated for a 46-gene NGS panel during 1-year were included in this retrospective study. Patient and procedure variables were collected. An imaging-based likelihood of adequacy score incorporating targeting and sampling factors was assigned to each biopsied lesion. Univariate and multivariate logistic regression was performed. RESULTS: 153 patients were included (58.2% female, average age 59.5 years). The most common malignancy was lung cancer (40.5%), most common biopsied site was lung (36%), and average size of biopsied lesions was 3.8 cm (+/- 2.7). Adequacy for NGS was 69.9%. Univariate analysis showed higher likelihood of adequacy score (p = 0.004), primary malignancy type (p = 0.03), and absence of prior systemic therapy (p = 0.018) were associated with adequacy for NGS. Multivariate analysis showed higher adequacy for lesions with likelihood of adequacy scored 3 (high) versus lesions scored 1 (low) (OR, 7.82; p = 0.002). Melanoma lesions had higher adequacy for NGS versus breast cancer lesions (OR 9.5; p = 0.01). Absence of prior systemic therapy (OR, 6.1; p = 0.02) and systemic therapy 3 months before biopsy yielded greater adequacy for NGS. Lesions <3 cm had greater adequacy for NGS than larger lesions (OR 2.72, p = 0.02). CONCLUSION: As targeted therapy becomes standard for more cancers, percutaneous biopsy specimens adequate for NGS genomic testing will be needed. An imaging-based likelihood of adequacy score assigned by IR physicians and other pre-procedure variables can help predict the likelihood of biopsy adequacy for NGS.

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis.

PURPOSE: To evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy. MATERIALS AND METHODS: In this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if the absolute difference in their propensity scores was ≤equal to 0.02. RESULTS: Before matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates. CONCLUSIONS: The self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.

Minimally invasive image-guided therapies for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most frequently occurring cancer globally and predominantly develops in the setting of various grades of underlying chronic liver disease, which affects management decisions. Image-guided percutaneous ablative or transarterial therapies have acquired wide acceptance in HCC management as a single treatment modality or combined with other treatment options in patients who are not amenable for surgery. Recently, such treatment modalities have also been used for bridging or downsizing before definitive treatment (ie, surgical resection or liver transplantation). This review focuses on the use of minimally invasive image-guided locoregional therapies for HCC. Additionally, it highlights recent advancements in imaging and catheter technology, embolic materials, chemotherapeutic agents, and delivery techniques; all lead to improved patient outcomes, thereby increasing the interest in these invasive techniques.

Yttrium-90 resin microspheres as an adjunct to sorafenib in patients with unresectable hepatocellular carcinoma.

PURPOSE: The safety and efficacy of the combined use of sorafenib and yttrium-90 resin microspheres (Y90 RMS) to treat advanced hepatocellular carcinoma (HCC) is not well established. We determined the incidence of adverse events with this combination therapy in patients with advanced HCC at our institution and analyzed the treatment and survival outcomes. MATERIALS AND METHODS: We reviewed the records of 19 patients with Barcelona Clinic Liver Cancer class B or C HCC who underwent treatment with Y90 RMS (for 21 sessions) while receiving full or reduced doses of sorafenib between January 2008 and May 2010. Therapy response was evaluated using Response Evaluation Criteria in Solid Tumors. We evaluated median overall survival (OS) and progression-free survival (PFS) as well as hepatic and extrahepatic disease PFS and incidence of adverse events. RESULTS: The median patient age was 67 years, and portal or hepatic venous invasion was present in eight patients (42%). Ten patients received reduced doses of sorafenib. The median Y90 radiation activity delivered was 41.2 mCi. The partial response of Response Evaluation Criteria in Solid Tumors was observed in four patients (19%). The median hepatic disease PFS was 7.82 months, extrahepatic disease PFS was 8.94 months, OS was 19.52 months, and PFS was 6.63 months. Ninety days after treatment with Y90 RMS, five patients (26%) had grade II adverse events and four patients (21%) had grade III adverse events. CONCLUSION: OS and PFS outcomes were superior to those observed in prior studies evaluating sorafenib alone in patients with a similar disease status, warranting further study of this treatment combination.

Eradication of Missing Liver Metastases After Fiducial Placement.

BACKGROUND: The risk of colorectal liver metastases (CLM) disappearing on cross-sectional imaging has increased with advances in preoperative chemotherapy, but <50 % of disappearing CLM demonstrate complete pathological response. OBJECTIVE: The aim of this study was to evaluate the role of fiducial marker placement before potentially curative treatment of CLM at risk of disappearing with chemotherapy. METHODS: All consecutive patients who underwent fiducial placement for tracking of CLM at a tertiary center were reviewed. RESULTS: Among 1377 patients undergoing CLM resection between 2005 and 2015, 35 patients underwent fiducial placement. Three patients were excluded due to disease progression. The study population comprised 32 patients who underwent fiducial placement in 41 CLM. Among the 41 marked CLM, 34 (83 %) were located >10 mm deep in the liver parenchyma, 25 (61 %) were in the right liver, and median size was 12 mm (range, 6-20 mm). No complication occurred after fiducial placement. After chemotherapy, 19 (46 %) of the 41 marked metastases disappeared on cross-sectional imaging. All fiducial-tracked CLM were treated with resection (n = 31) or ablation (n = 10). After median follow-up of 14 months (range, 0-64 months), no local recurrences were observed. CONCLUSION: Fiducial placement represents a safe procedure that facilitates accurate localization for resection or ablation of small CLM at risk of disappearing with chemotherapy.

Gold Nanoparticles in Cancer Therapy: Efficacy, Biodistribution, and Toxicity.

Gold-based nanoparticles are utilized for cancer therapeutics as a system for drug delivery, or as a mediator for thermal therapy, whether ablation or hyperthermia. This review discusses how the design of the physicochemical properties of the different types of gold-based nanoparticles affects their treatment efficacy. The basic principles and mechanism at which it mediates heating and delivers drugs efficiently in vivo is also summarized. We will also review the in vivo preclinical data on the biodistribution, intratumoral distribution, cell internalization, and its associated toxicity. Lastly, an updated list of the clinical trials based on nanoparticles and future perspectives are provided.

Photoacoustic- and Magnetic Resonance-Guided Photothermal Therapy and Tumor Vasculature Visualization Using Theranostic Magnetic Gold Nanoshells.

Nanoparticle based image-guided therapy is an emerging technology for cancer in recent years. Here, we report simultaneous photoacoustic (PA)- and magnetic resonance (MR)-guided photothermal ablation (PTA) therapy using multifunctional superparamagnetic iron oxide-containing gold nanoshells (SPIO@AuNS). Based on the intrinsic high near-infrared optical absorbance and strong magnetic property of SPIO@AuNS, we carried out in vivo dual-modality PA-MR imaging of mouse tumors. PA- and MR-guided imaging can monitor therapeutic effect after photothermal therapy mediated by our multifunctional nanomaterial. In addition, using our pulsed laser PA technique, we also observe a clearer structure of the tumor vasculature after intravenously administration SPIO@AuNS. The novel dual PA-MRI image-guided PTA therapy provides a promising new platform for cancer diagnosis and treatment simultaneously.

Transarterial hepatic chemoembolization with 70-150 µm drug-eluting beads: assessment of clinical safety and liver toxicity profile.

PURPOSE: To assess the incidence and severity of adverse events (AEs) in the form of clinical symptoms and liver/biliary injuries (LBI) in patients with hepatic malignancies treated with transarterial chemoembolization using 70-150 µm drug-eluting beads (DEBs). MATERIALS AND METHODS: A single-institution retrospective analysis was performed in 37 patients (25 patients with hepatocellular carcinoma and 12 patients with metastatic disease) who underwent 43 sessions of segmental/subsegmental 70-150 µm DEB transarterial chemoembolization with doxorubicin (38 sessions) or irinotecan (5 sessions). Patient inclusion criteria included the presence of the following lesion features: small diameter (≤ 3 cm), hypovascular, or with areas of residual disease after other locoregional therapies. Mean tumor diameter was 3.4 cm. Mean imaging and clinical follow-up periods were 171 days and 373 days, respectively. Clinical, laboratory, and imaging data were used to identify and classify clinically symptomatic AEs per session and LBI per patient according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03. Predictors for the occurrence of LBI were evaluated by logistic regression analysis. RESULTS: No grade 4 or 5 AEs were recorded. Clinically symptomatic AEs occurred in 29 (67.4%) sessions (grade 1-2, 28 sessions; grade 3, 1 session), all constituting postembolization syndrome. Asymptomatic LBI occurred in 11 (29.7%) patients (grade 1, 8 patients; grade 2, 3 patients). The mean time between 70-150 µm DEB transarterial chemoembolization session and appearance of LBI was 71 days (range, 21-223 d). No predictive factors for the development of LBI were identified. CONCLUSIONS: Transarterial chemoembolization with 70-150 µm DEBs was considered safe in the present study population given the acceptably low incidence and severity of AEs.

The Effect of Needle Gauge on the Risk of Pneumothorax and Chest Tube Placement After Percutaneous Computed Tomographic (CT)-Guided Lung Biopsy.

BACKGROUND: The aim of this study was to evaluate the effect of coaxial guide needle gauge (18 vs. 19 gauge) on the risk of pneumothorax and chest tube placement after CT-guided lung biopsy. METHODS: Imaging records of all patients who had undergone CT-guided lung biopsies at our institution from March 1, 2006 to December 9, 2010 were retrospectively reviewed. Univariate and multivariate logistic regression analyses were performed to assess the effect of various patient-, lesion-, and procedure-related variables on subsequent pneumothorax and chest tube placement rates. RESULTS: The study included 4262 biopsies (2304 with 18-gauge and 1958 with 19-gauge coaxial guide needles) in 3917 patients. The rates of pneumothorax and chest tube placement were 30.2 and 15%, respectively. Pneumothorax occurred in 35% of procedures performed with 18-gauge needles and in 24.5% of procedures performed with 19-gauge needles (p < 0.0001). Chest tube insertion occurred in 16.7% of procedures performed with 18-gauge needles and in 13.1% of procedures performed with 19-gauge needles (p = 0.0011). Multivariate logistic regression models demonstrated that the use of an 18-gauge needle was associated with a higher rate of pneumothorax (p < 0.0001) and chest tube placement (p = 0.0003). The following factors were also associated with higher rates of pneumothorax and chest tube placement: older age, emphysema, greater number of pleural surfaces crossed, and a longer biopsy needle path length. CONCLUSIONS: The use of a 19-gauge coaxial guide needle significantly decreases the risk of pneumothorax and chest tube placement compared with an 18-guage needle.

Pilot in vivo study of an absorbable polydioxanone vena cava filter.

OBJECTIVE: The objectives of this study were to evaluate tensile strength retention of polydioxanone as a function of time in a swine venous system and to assess the feasibility of an absorbable inferior vena cava (IVC) filter made from polydioxanone in a pilot swine study. METHODS: Twenty strands (60 cm each) of size 1 polydioxanone absorbable suture (Ethicon, Somerville, NJ) were placed in the central venous system of domestic swine. Strands were harvested at weekly intervals during 10 weeks for tensile strength testing. Results were compared with control samples obtained from an in vitro engineered circulation system containing sodium phosphate buffer solution. Three IVC filters braided from polydioxanone suture were also catheter deployed in three swine to assess absorbable IVC filter feasibility. RESULTS: Polydioxanone retained 82% tensile strength in vitro vs 79% in vivo at 35 days (P > .22), the desired prophylactic duration. For IVC filters made from polydioxanone, technical success of placement was achieved in all three filters deployed (100%). Autologous thrombus deployed inferior to the filter remained trapped in the filter until thrombus resorption, with no evidence of pulmonary emboli on follow-up computed tomography. There were no instances of caval penetration, filter-induced IVC thrombosis, filter migration, or tilt >15 degrees with imaging and clinical follow-up carried out to 32 weeks. CONCLUSIONS: Strength retention of polydioxanone suture placed in the venous system of swine is similar to earlier in vitro studies out to 10 weeks (P > .06 for all weeks) and is more than sufficient (8.20 ± 0.37 kg mean load at break for size 1) to trap thrombus. Pilot animal study suggests that an absorbable polydioxanone IVC filter can be catheter deployed to capture and to hold iatrogenically administered autologous thrombus through resorption.

Volume regeneration of segments 2 and 3 after right portal vein embolization in patients undergoing two-stage hepatectomy.

BACKGROUND: The impact of first-stage resection on volume regeneration of segments 2 and 3 (2 + 3) after right portal vein embolization (RPVE) in patients undergoing two-stage right hepatectomy has not been investigated. METHOD: Volume data for segments 2 + 3 were compared between 44 patients undergoing two-stage hepatectomy and 116 undergoing single-stage hepatectomy after RPVE. RESULTS: The degree of hypertrophy (difference between standardized volume of segments 2 + 3 before and after RPVE) and kinetic growth rate (degree of hypertrophy at initial volume assessment divided by the number of weeks elapsed after RPVE) were significantly lower in patients undergoing two-stage hepatectomy (median 8.6 vs 10.5% [p = 0.01] and 1.7 vs 2.4% [p < 0.01], respectively). Resection volume during first-stage resection was negatively correlated with standardized volume increase from the volume before first-stage resection (R (2) 0.546, p < 0.01). In patients undergoing two-stage hepatectomy after RPVE with segment 4 embolization, the degree of hypertrophy and kinetic growth rate were similar to those in patients undergoing single-stage hepatectomy (p = 0.17 and p = 0.08, respectively). CONCLUSION: In patients undergoing two-stage hepatectomy, first-stage resection impairs the dynamics of volume regeneration of segments 2 + 3 after RPVE. When two-stage extended right hepatectomy is planned, additional embolization of segment 4 provides volume hypertrophy similar to that in patients undergoing single-stage hepatectomy.

Safety and diagnostic accuracy of percutaneous biopsy in upper tract urothelial carcinoma.

OBJECTIVE: To assess the diagnostic accuracy and safety of percutaneous biopsy for upper tract urothelial carcinoma (UTUC). PATIENTS AND METHODS: From 2002 to 2013, 26 upper tract lesions in 24 patients (20 men; median [range] age 67.8 [51.7-85.9] years) were percutaneously biopsied. Analysis was separated based on lesion appearance: (i) mass infiltrating renal parenchyma, (ii) filling defect in the collecting system, (iii) urothelial wall thickening. We tracked immediate complications and tract seeding on follow-up imaging. RESULTS: Of the 26 upper tract lesions, 15 (58%) were masses infiltrating the renal parenchyma (mean [range] size 5.4 [1.1-14.0] cm), six (23%) were urothelial wall thickenings (mean [range] size 0.8 [0.4-1.1] cm), and five (19%) were filling defects within the renal pelvis or calyx (mean [range] size 2.7 [1.0-4.6] cm). Definitive diagnosis of UTUC was made by biopsy in 22 of 26 lesions (85%). Biopsy characterised 14 of 15 infiltrative masses and five of five filling defects; biopsy characterised three of six cases of urothelial wall thickening. CT follow-up was available for 19 patients (73%) at a median (range) of 13.6 (1.0-98.9) months. Three patients (11%) developed recurrence in the nephrectomy bed at 5.6, 9.7, and 29.0 months after biopsy; none were attributed to tract seeding after independent review, because recurrence was remote from the biopsy site. CONCLUSION: Percutaneous biopsy is effective for diagnosis of UTUC, providing tissue diagnosis in 85% of cases. While case reports cite a risk of tract seeding, no cases of recurrence were definitely attributable to percutaneous biopsy. Thus, for upper tract urothelial lesions, which are not amenable to endoscopic biopsy, percutaneous biopsy is a safe and effective technique.

Image-guided interventions in oncology.

Interventional oncology, a term commonly used to indicate the minimally invasive procedures performed by interventional radiologists to diagnose and manage cancer, encompasses a broad spectrum of techniques unique to interventional radiology that have been established as a vital part of the multidisciplinary oncologic cancer care team. This article provides an updated overview of the variety of applications of image-guided procedures to distinct clinical scenarios, such as the diagnosis, treatment, and management of complications of malignancies.

Irreversible electroporation of the lumbar vertebrae in a porcine model: is there clinical-pathologic evidence of neural toxicity?

PURPOSE: To evaluate the effects of irreversible electroporation (IRE) in the porcine spine. MATERIALS AND METHODS: This study was approved by the institutional animal care and use committee. Twenty computed tomographically guided IRE ablations in either a transpedicular location or directly over the posterior cortex were performed in the lumbar vertebrae of 10 pigs by a single operator. T1- and T2-weighted magnetic resonance (MR) imaging was performed with and without contrast material 2 or 7 days after ablation. Mathematical modeling was performed to estimate the extent of ablation. Clinical, radiologic, pathologic, and simulation findings were analyzed. The Miller low-bias back transformation was used to construct 95% confidence intervals for the mean absolute percentage difference between the maximum length and width of the ablation zone on MR images and pathologic measurements by using square-root-transformed data. RESULTS: Bipolar IRE electrode placement and ablation were successful in all cases. The mean distances from the IRE electrode to the posterior wall of the vertebral body or the exiting nerve root were 2.93 mm ± 0.77 (standard deviation) and 7.87 mm ± 1.99, respectively. None of the animals had neurologic deficits. Well-delineated areas of necrosis of bone, bone marrow, and skeletal muscle adjacent to the vertebral body were present. Histopathologic changes showed outcomes that matched with simulation-estimated ablation zones. The percentage absolute differences in the ablation measurements between MR imaging and histopathologic examination showed the following average errors: 24.2% for length and 28.8% for width measurements on T2-weighted images, and 26.1% for length and 33.3% for width measurements on T1-weighted contrast material-enhanced images. CONCLUSION: IRE ablation in the porcine spine is feasible and safe and produces localized necrosis with minimal neural toxicity. Signal intensity changes on images acquired with standard MR imaging sequences demonstrate the ablation zone to be larger than that at histopathologic examination.

Early initiation of enteral feeding in cancer patients after outpatient percutaneous fluoroscopy-guided gastrostomy catheter placement.

PURPOSE: To report the results of early enteral feeding in patients with cancer after outpatient placement of a percutaneous fluoroscopy-guided gastrostomy (PFG). MATERIALS AND METHODS: From January 2008 through December 2008, 121 consecutive patients with cancer underwent outpatient placement of a PFG for nutrition. Of these patients, 118 patients met criteria for early feeding, and 113 were successfully fed early (after at least 3 hours). Of the patients fed early, 5 had insufficient follow-up for further analysis leaving 108 patients for outcomes analysis. After placement of the PFG, patients were put on low-wall suction via the PFG for 1 hour followed by feeding via the PFG at least 3 hours after placement. Follow-up evaluation was done the next business day. The medical records were reviewed for 30-day outcomes of early feeding, technical aspects of the procedures, and complications. RESULTS: After placement of the PFG, 98% (118 of 121) of patients met criteria for early feeding, and 93% (113 of 121) of patients were successfully fed early. The median time between the end of the procedure and initiation of feeding was 4 hours (interquartile range, 3.7-4.4 h). The 30-day minor complication rate was 14% (15 of 108), and the 30-day major complication rate was 1% (1 of 108). No complications were directly attributable to early feeding. CONCLUSIONS: Early initiation of tube feedings after outpatient placement of a PFG was well tolerated in patients with cancer and carried comparable risks to previously reported results using traditional delayed feeding protocols. Early feeding provided patients with prompt enteral nutrition and eliminated the need for routine hospital admission after the procedure.

Efficacy and safety of portal vein embolization for two-stage hepatectomy in patients with colorectal liver metastasis.

PURPOSE: To examine the efficacy and safety of portal vein embolization (PVE) when used during two-stage hepatectomy for bilobar colorectal liver metastases (CLM). MATERIALS AND METHODS: PVE was performed as an adjunct to two-stage hepatectomy in 56 patients with CLM. Absolute future liver remnant (FLR) volumes, standardized FLR ratios, degree of hypertrophy (DH), and complications were analyzed. Segment II and III volumes and DH were also measured separately. All volumetric measurements were compared with a cohort of 96 patients (n = 37 right portal vein embolization [RPVE], n = 59 right portal vein embolization extended to segment IV portal veins [RPVE+4]) in whom PVE was performed before single-stage hepatectomy. RESULTS: For patients who completed RPVE during two-stage hepatectomy (n = 17 of 17), mean absolute FLR volume increased from 272.1 cm(3) to 427.0 cm(3) (P < .0001), mean standardized FLR ratio increased from 0.17 to 0.26 (P < .0001), and mean DH was 0.094. For patients who completed RPVE+4 during two-stage hepatectomy (n = 38 of 39), mean FLR volume increased from 288.7 cm(3) to 424.8 cm(3) (P < .0001), mean standardized FLR increased from 0.18 to 0.26 (P < .0001), and mean DH was 0.083. DH of the FLR was not significantly different between two-stage hepatectomy and single-stage hepatectomy. Complications after PVE occurred in five (8.9%) patients undergoing two-stage hepatectomy. CONCLUSIONS: PVE effectively and safely induced a significant DH in the FLR during two-stage hepatectomy in patients with CLM.