Advanced endografting techniques: snorkels, chimneys, periscopes, fenestrations, and branched endografts

The anatomy of aortic aneurysms from the proximal neck to the access vessels may create technical challenges for endovascular repair. Upwards of 30% of patients with abdominal aortic aneurysms (AAA) have unsuitable proximal neck morphology for endovascular repair. Anatomies considered unsuitable for conventional infrarenal stent grafting include short or absent necks, angulated necks, conical necks, or large necks exceeding size availability for current stent grafts. A number of advanced endovascular techniques and devices have been developed to circumvent these challenges, each with unique advantages and disadvantages. These include snorkeling procedures such as chimneys, periscopes, and sandwich techniques; "homemade" or "back-table" fenestrated endografts as well as manufactured, customized fenestrated endografts; and more recently, physician modified branched devices. Furthermore, new devices in the pipeline under investigation, such as "off-the-shelf" fenestrated stent grafts, branched stent grafts, lower profile devices, and novel sealing designs, have the potential of solving many of the aforementioned problems. The treatment of aortic aneurysms continues to evolve, further expanding the population of patients that can be treated with an endovascular approach. As the technology grows so do the number of challenging aortic anatomies that endovascular specialists take on, further pushing the envelope in the arena of aortic repair.

Endovascular management of acute aortic dissection

Acute dissection of the thoracic aorta is a potentially life-threatening condition which requires collaborative treatment from multiple specialties for optimal patient outcomes. Dissections involving the ascending aorta and aortic arch have traditionally been managed entirely by surgery, while dissections beyond the arch vessels have most commonly been relegated to medical management. This algorithm has been undergoing a paradigm shift over the past two decades due to improvements in stent graft technology, better understanding of the hemodynamic interactions of the true and false lumen and their influence on organ and limb perfusion, and improvements in medical management and long term surveillance for dissection-related complications. This manuscript includes a brief discussion of the pathogenesis and etiology of dissection, followed by an in-depth review of the medical and endovascular techniques utilized to treat patients afflicted by this condition.

Is there a connection between postprandial hyperglycemia and IGT related sensory nerve dysfunction?

BACKGROUND AND AIMS

To assess the risk factors for sensory nerve dysfunction in subjects with isolated impaired glucose tolerance (IGT).

METHODS AND RESULTS

Seventy-two people with isolated IGT (WHO 1999 criteria) and 39 gender and age-matched healthy volunteers underwent detailed clinical and neurological assessment including quantitative sensory testing using the Neurometer device (current perception threshold measurement on four limbs at three different frequencies). Sensory nerve dysfunction was defined as at least two abnormalities on any frequencies on the upper or lower limbs. Sensory nerve dysfunction was more prevalent among subjects with IGT compared to controls (58.3 vs. 10.3%, OR: 11.23, 95%CI: 3.57-35.35). This association was not influenced by BMI, systolic and diastolic blood pressure, heart rate and autonomic neuropathy (multiple adjusted OR: 13.87, 95%CI: 3.18-60.58), but further adjustment for glycaemic measures abolished the association (OR: 1.58, 95%CI: 0.07-35.68). Assessing the components of glycaemic measures separately, the association between sensory nerve dysfunction and IGT was not affected by HbA1c (OR: 13.94, 95%CI: 1.84-105.5). It was, however, substantially attenuated by fasting plasma glucose (OR: 6.75, 95%CI: 1.33-34.27) while the significance was lost after adjustment for 120 min postload glucose level (OR: 3.76, 95%CI: 0.26-54.10). In the pooled population assessed, independent determinants of sensory nerve dysfunction were older age, 120 min glucose, higher height and cardiovascular autonomic neuropathy at near significance.

CONCLUSIONS

Sensory nerve dysfunction amongst subjects with IGT was not explained by cardiovascular covariates, only by glycaemic measures. In addition to 120 min glucose, cardiovascular autonomic neuropathy at borderline significance, age, and height were the independent determinants of sensory nerve dysfunction.

Stage-specific differences in secretory profile of mesenchymal stromal cells (MSCs) subjected to early- vs late-stage OA synovial fluid

OBJECTIVE

Although, mesenchymal stromal cells (MSCs) are being clinically investigated for their use in osteoarthritis (OA), it is unclear whether their postulated therapeutic properties are equally effective in the early- and late-stages of OA. In this study we investigated MSC cytokine secretion post-exposure to synovial fluid (SF), obtained from early- vs late-stage knee OA patients to justify a potential patient stratification strategy to maximize MSC-mediated treatment effects.

METHOD

Subjects were recruited and categorized into early- [Kellgren-Lawrence (KL) grade I/II, n = 12] and late-stage (KL-III/IV, n = 12) knee OA groups. SF samples were obtained, and their proteome was tested using multiplex assays, after 3-days culture, with and without MSCs. SFs cultured without MSCs were used as a baseline to identify MSC-secreted factors into SFs cultured with MSCs. Linear mixed-effect models and non-parametric tests were used to identify alterations in the MSC secretome during exposure to OA SF (3-days). MSCs cultured for 3-days in 0.5% fetal bovine serum (FBS)-supplemented medium were used to compare SF results with culture medium.

RESULTS

Following exposure to OA SF, the MSC secretome contained proteins that are involved in tissue repair, angiogenesis, chemotaxis, matrix remodeling and the clotting process. However, chemokine (C-X-C motif) ligand-8 (CXCL8; chemoattractant), interleukin-6 (IL6) and chemokine (C-C motif) ligand 2 (CCL2) were elevated in the MSC-secretome in response to early- vs late-stage OA SF.

CONCLUSION

Early- vs late-stage OA SF samples elicit a differential MSC secretome response, arguing for stratification of OA patients to maximize MSC-mediated therapeutic effects.

The Effect of a New Angiographic Imaging Technology on Radiation Dose in Visceral Embolization Procedures

PURPOSE

To evaluate the impact of a new angiographic imaging technology on radiation dose during visceral embolization procedures involving both fluoroscopy and digital subtraction angiography.

MATERIAL AND METHODS

A retrospective analysis from a single-center consecutive series of patients was performed comparing 2 angiographic imaging systems. The AlluraClarity (CIQ; Philips Healthcare, Best, the Netherlands) was used in 100 patients (n = 59 male, mean age: 70.6 years) from July 2013 to April 2014 and compared to the former AlluraXper (AX) technology used in 139 patients (n = 71 male, mean age: 70.1 years) from May 2011 to June 2013. Patients were categorized according to body mass index (BMI [kg/m²])-group 1: BMI <25, group 2: BMI ≥25 and <30, and group 3: BMI ≥30. Fluoroscopy time, the total dose of iodinated contrast administered, and procedural AirKerma (Ka, r [mGy]) were obtained.

RESULTS

Mean BMI was 26.4 ± 5.0 kg/m² in the CIQ and 26.4 ± 7.1 kg/m² in the AX group ( P = .93). Fluoroscopy time and the amount of contrast media were equally distributed. Ka, r was 1342.9 mGy versus 2214.8 mGy ( P < .001, t test) when comparing CIQ to AX. Comparing CIQ to AX, BMI subgroup analysis revealed a mean Ka, r of 970.1 to 1586.1 mGy ( P = .003, t test), 1484.7 to 2170.1 mGy ( P = .02, t test), and 1848.8 to 3348.9 mGy ( P = .001, t test) in BMI groups 1, 2, and 3, respectively.

CONCLUSION

The CIQ technology significantly reduced mean radiation dose by 39.4% for visceral embolization procedures when compared to fluoroscopy time and contrast media dose. This dose relationship was consistent across all BMI groups.

A Phase 2 Randomized Study Investigating the Efficacy and Safety of Myostatin Antibody LY2495655 versus Placebo in Patients Undergoing Elective Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty relieves joint pain in patients with end stage osteoarthritis. However, postoperative muscle atrophy often results in suboptimal lower limb function. There is a need to improve functional recovery after total hip arthroplasty.

OBJECTIVES

To assess safety and efficacy of LY2495655, a humanized monoclonal antibody targeting myostatin, in patients undergoing elective total hip arthroplasty.

DESIGN

Phase 2, randomized, parallel, double-blind, 12-week clinical trial with a 12-week follow-up period.

SETTING

Forty-two sites in 11 countries.

PARTICIPANTS

Individuals (N=400) aged ≥50 years scheduled for elective total hip arthroplasty for osteoarthritis within 10 ± 6 days after randomization.

INTERVENTION

Placebo or LY2495655 (35 mg, 105 mg, or 315 mg) subcutaneous injections at weeks 0 (randomization date), 4, 8, and 12 with follow up until week 24.

MEASUREMENTS

Primary endpoint: probability that LY2495655 increases appendicular lean mass (operated limb excluded) by at least 2.5% more than placebo at week 12, using dual-energy x-ray absorptiometry. Exploratory endpoints: muscle strength, performance based and self-reported measures of physical function, and whole body composition over time.

RESULTS

Participants: 59% women, aged 69 ± 8 years, BMI 29 ± 5 kg/m2. Groups were comparable at baseline. The primary objective was not reached as LY2495655 changes in lean mass did not meet the superiority threshold at week 12. However, LY2495655 105 and LY2495655 315 experienced progressive increases in appendicular lean mass that were statistically significant versus placebo at weeks 8 and 16. Whole body fat mass decreased in LY2495655 315 versus placebo at weeks 8 and 16. No meaningful differences were detected between groups in other exploratory endpoints. Injection site reactions occurred more often in LY2495655 patients than in placebo patients. No other safety signals were detected.

CONCLUSION

Dose-dependent increases in appendicular lean body mass and decreases in fat mass were observed, although this study did not achieve the threshold of its primary objective.

Putting the baby back in the bathwater

Recently, several high impact randomised controlled trials have been published suggesting no greater benefit from orthopaedic surgery over conservative treatment, or limited surgical intervention. These studies can have profound effects on clinical practice, leading to the abandonment of previously widely-used operations.

How do surgeons who believe these operations are beneficial over conservative treatment rationalise these findings, and justify their use with hospital administrators and health care funders who require evidence for the value and efficacy of surgical treatment?

Cite this article: Bone Joint J 2015;97-B:1456–7.

Single-Center Experience Comparing the Application of Small-Caliber versus Large-Caliber Arterial Access Closure in a Consecutive Series of Patients

PURPOSE

To compare the closure of ≤ 8-F versus 9-F to 12-F femoral access using the 8-F Angio-Seal VIP device (St. Jude Medical, Inc, St. Paul, Minnesota).

MATERIALS AND METHODS

In this investigator-initiated, retrospective analysis, a consecutive series of 137 patients (n = 92 male patients [67.2%]; overall mean age, 71.0 y ± 9.8) was evaluated. Common femoral artery access was performed in all patients, and either unfractionated heparin or bivalirudin was used for anticoagulation. Access site complications were defined as follows: type 0, no bleeding; type 1, no actionable bleeding; type 2, actionable bleeding.

RESULTS

The 8-F Angio-Seal VIP device was used for closure of ≤ 8-F femoral access in 76 patients (55.5%) and for 9-F to 12-F femoral access in 61 patients (44.5%). Access site complications were observed after 8-F Angio-Seal deployment in 11 patients (8.0%) (≤ 8 F, n = 5 [6.6%]; 9-12 F, n = 6 [9.8%]; P = .54). Comparing ≤ 8-F with 9-F to 12-F femoral access, type 1 complications were observed in 3 and 6 patients (P = .19) and type 2 complications were observed in 2 and 0 patients (P = .50), respectively. All type 1 complications were managed by applying external compression. Type 2 complications (n = 2 pseudoaneurysms) were treated with thrombin injection in 1 patient and secondary percutaneous intervention in 1 patient.

CONCLUSIONS

Use of the 8-F Angio-Seal for the closure of > 8-F femoral access is safe and effective. Complication rates when using the 8-F Angio-Seal for closure of ≤ 8-F and 9-F to 12-F femoral access are comparable.

Predicting return to work following treatment of chronic pain disorder

BACKGROUND

The care of injured workers with chronic pain remains an important public health issue given its increasing prevalence. The consequences often include loss of self-esteem and stress in family relationships.

AIMS

To report our interdisciplinary approach to the care of chronic pain disorder (CPD) and describe the predictors associated with a successful return to work (RTW).

METHODS

Relevant covariates, including demographic data, time from injury, and functional scores were recorded for clients injured at work in Ontario, Canada. Our primary outcome, RTW, was assessed at 3 months post-discharge. Descriptive statistics and logistic regression were used to identify those factors predicting a successful RTW.

RESULTS

Of the injured workers who participated in the interdisciplinary CPD treatment programme, 1002 clients met our inclusion criteria and were included in the study. Fifty-five per cent were male with a mean age of 46 years. Median time from injury to treatment was 720 days. At 3 months post-treatment, 136 (14%) of the participants were working. Multivariable logistic regression revealed that earlier time since injury (OR = 0.71, 95% CI 0.55-0.92) and presence of an RTW coordinator (RTWC) (OR = 3.42, 95% CI 2.08-5.63) were significant predictors of successful RTW. There was also a significant interaction between RTWC involvement and time since injury. The latter did not appear to influence the likelihood of RTW when an RTWC was present.

CONCLUSIONS

Workers compensation boards should refer injured workers with CPD to treatment programmes as early as possible to achieve a successful RTW. Additionally, RTWCs play an important role in improving work outcomes.

Current clinical practice in postoperative endovascular aneurysm repair imaging surveillance

PURPOSE

To investigate the current clinical practice in postoperative endovascular aneurysm repair (EVAR) imaging surveillance.

MATERIALS AND METHODS

Corresponding authors of EVAR publications during the years 2006-2011 and subscribers to an endovascular journal were invited to complete a 27-question online survey related to institutional demographics, standard post-EVAR imaging surveillance, and imaging protocols in special circumstances (eg, renal insufficiency).

RESULTS

The survey was completed by 515 of 9,631 physicians performing EVAR from 52 countries. Of respondents, 65.3% were affiliated with experienced centers where EVAR has been performed for > 10 years or with > 50 EVAR procedures performed per year. Computed tomography (CT) angiography was the modality used most often for standard surveillance with a maximum time interval between studies of 12 months in 78.8% of centers out to 5 years. Experienced centers were more likely to delay follow-up imaging to 1 year after an unremarkable initial post-EVAR imaging study (P < .001), to extend surveillance intervals > 12 months (P = .043), and to use ultrasound (P < .01) for surveillance. After the detection of a type II endoleak, CT angiography was favored for follow-up by 59.4% of the respondents. Experienced centers were more likely to favor ultrasound (P = .006) and to schedule this follow-up examination later (after 6-12 months, P < .001). Of respondents, 62.8% used a glomerular filtration rate threshold of < 30 mL/min for not performing contrast-enhanced CT scan. In patients with renal insufficiency, most respondents performed ultrasound with or without a concomitant noncontrast CT scan.

CONCLUSIONS

CT is the most frequently used method of long-term surveillance after EVAR. Use of ultrasound for long-term surveillance, extension of follow-up time intervals, or both were most often reported in experienced centers.

A comparative study of the performance of individuals with fragile X syndrome and Fmr1 knockout mice on Hebb-Williams mazes

Fragile X syndrome (FXS) is the most prevalent form of heritable mental retardation. It arises from a mutation in the FMR1 gene on the X chromosome that interferes with expression of fragile X mental retardation protein (FMRP) and leads to a wide range of behavioural and cognitive deficits. Previous studies have shown a deficit in basic visual perceptual processing as well as spatial abilities in FXS. How such a deficit may impact spatial navigation remains unknown. The current study extended previous research by evaluating spatial learning and memory using both virtual and physical versions of Hebb-Williams mazes, which allows for testing of humans and animals under comparable conditions. We compared the performance of individuals affected by FXS to typically developing individuals of equivalent mental age as well as the performance of Fmr1 knockout mice to wild-type control mice on the same maze problems. In human participants, performance of the comparison group improved across trials, showing expected significant decreases in both errors and latency. In contrast, the performance of the fragile X group remained at similar levels across trials. Although wild-type control mice made significantly fewer errors than the Fmr1 knockout mice, latencies were not statistically different between the groups. These findings suggest that affected humans and mice show similar spatial learning deficits attributable to the lack of FMRP. The implications of these data are discussed including the notion that Hebb-Williams mazes may represent a useful tool to examine the impact of pharmacological interventions on mitigating or reversing the symptoms associated with FXS.

Length of stay, mortality, morbidity and delay to surgery in hip fractures

Our aim was to determine the effect of delay to surgery on the time to discharge, in-hospital death, the presence of major and minor medical complications and the incidence of pressure sores in patients with a fracture of the hip. All patients admitted to Vancouver General Hospital with this injury between 1998 and 2001 inclusive were identified from our trauma registry. A review of the case notes was performed to determine the delay in time from admission to surgery, age, gender, type of fracture and medical comorbidities. A time-to-event analysis was performed for length of stay. Additionally, a Cox proportional hazards model was used to determine the effect of delay to surgery on the length of stay while controlling for other pertinent confounding factors. Using logistical regression we determined the effect of delay to surgery on in-hospital death, medical complications and the presence of pressure sores, while controlling for confounding factors. Delay to surgery (p = 0.0255), comorbidity (p < 0.0001), age (p < 0.0001) and type of fracture (p = 0.0004) were all significant in the Cox proportional hazards model for increased time to discharge. Delay to surgery was not a significant predictor of in-hospital mortality. However, a delay of more than 24 hours was a significant predictor of a minor medical complication (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.05 to 2.22), while a delay of more than 48 hours was associated with an increased risk of a major medical complication (OR 2.21, 95% CI 1.01 to 4.34), a minor medical complication (OR 2.27, 95% CI 1.38 to 3.72) and of pressure sores (OR 2.29, 95% CI 1.19 to 4.40). Patients with a fracture of the hip should have surgery early to lessen the time to acute-care hospital discharge and to minimise the risk of complications.

Survival and clinical function of cemented and uncemented prostheses in total knee replacement

Using meta-analysis we compared the survival and clinical outcomes of cemented and uncemented techniques in primary total knee replacement. We reviewed randomised controlled trials and observational studies comparing cemented and uncemented fixation. Our primary outcome was survival of the implant free of aseptic loosening. Our secondary outcome was joint function as measured by the Knee Society score. We identified 15 studies that met our final eligibility criteria. The combined odds ratio for failure of the implant due to aseptic loosening for the uncemented group was 4.2 (95% confidence interval (CI) 2.7 to 6.5) (p < 0.0001). Subgroup analysis of data only from randomised controlled trials showed no differences between the groups for odds of aseptic loosening (odds ratio 1.9, 95% CI 0.55 to 6.40, p = 0.314). The weighted mean difference for the Knee Society score was 0.005 (95% CI −0.26 to 0.26) (p = 0.972).

There was improved survival of the cemented compared to uncemented implants, with no statistically significant difference in the mean Knee Society score between groups for all pooled data.

Thalamic neuronal dysfunction and chronic sensorimotor distal symmetrical polyneuropathy in patients with type 1 diabetes mellitus

AIMS/HYPOTHESIS

Although clear peripheral nerve pathological abnormalities have been demonstrated in diabetic peripheral neuropathy (DPN), there is little information with regard to brain involvement. Our aim was to use in vivo proton magnetic resonance specroscopy (H-MRS) in patients with DPN in order to assess the neuro-chemical status of the thalamus, which acts as the gateway to the brain for somatosensory information.

METHODS

Participants included 18 type 1 diabetic men (eight without DPN, ten with DPN) and six non-diabetic healthy volunteers, who all underwent detailed clinical and neurophysiological assessments yielding a Neuropathy Composite Score (NCS) derived from Neuropathy Impairment Score of the Lower Limbs plus seven tests of nerve function prior to investigation via a single-voxel H-MRS technique, which was used to sample ventral posterior thalamic parenchyma. Spectroscopic resonances including those due to N-acetyl aspartate (NAA) were assessed at both short and long echo-time, providing putative indicators of neuronal function and integrity, respectively.

RESULTS

At long echo-time we observed significantly lower NAA:creatine (p = 0.04) and NAA:choline (p = 0.02) ratios in DPN patients than in the other groups. No group differences were detected at short echo-time. We found a significant positive association between both sural amplitude (rho = 0.61, p = 0.004) and nerve conduction velocity (r = 0.58, p = 0.006) and NAA:creatine signal among participants with diabetes. Vibration detection threshold (rho = -0.70, p = 0.004) was significantly related to NAA:choline ratio. Heart rate variability with deep breathing (rho = -0.46, p = 0.05) and NCS (rho = -0.53, p = 0.03) were significantly related to NAA:creatine ratio.

CONCLUSIONS/INTERPRETATION

The significantly lower NAA:creatine ratio in DPN is suggestive of thalamic neuronal dysfunction, while the lack of difference in short echo-time between the groups does not suggest neuronal loss. Taken together with the observed correlations between NAA and neurophysiological assessments, these findings provide evidence for thalamic neuronal involvement in DPN.

Relationship between autonomic neuropathy and hypertension--are we underestimating the problem?

BACKGROUND

Cardiac autonomic neuropathy (CAN) is associated with significant morbidity and mortality in diabetes and the risk is even greater in those with hypertension.

AIMS

The aim of our study was to investigate the relationship between CAN and 24-h blood pressure profile in normoalbuminuric patients with Type 2 diabetes mellitus.

METHODS

Seventy patients with Type 2 diabetes (31 without CAN, 39 with CAN), who had no history of hypertension, and 29 healthy volunteers underwent five standard cardiovascular reflex tests to assess autonomic function and 24-h ambulatory blood pressure monitoring.

RESULTS

Twenty-four-hour mean systolic blood pressure, blood pressure load and hyperbaric impact values were significantly higher in diabetic patients with CAN compared with control subjects and diabetic patients without CAN (P < 0.05). In spite of normal clinic blood pressures, 54% of diabetic subjects with CAN and 29% without CAN were hypertensive (systolic blood pressure load > 20%, P < 0.05). In the diabetes group as a whole, Valsalva ratio, postural systolic blood pressure changes and diastolic blood pressure responses during sustained handgrip correlated significantly and negatively with 24-h mean systolic blood pressure (P < 0.01, P < 0.001, P < 0.05) and blood pressure load (P < 0.05, P < 0.001, P < 0.05).

CONCLUSIONS

Cardiovascular autonomic neuropathy is independently associated with hypertension in normoalbuminuric Type 2 diabetic patients with no history of hypertension. Relying on clinic blood pressures in subjects with CAN could lead to a failure to diagnose hypertension in over half of cases. All normotensive patients with CAN should be screened for hypertension using ambulatory blood pressure monitoring in order to institute early aggressive interventions to improve their long-term outlook.

Anti-idiotype-mediated epitope spreading and diminished phagocytosis by a human monoclonal antibody recognizing late-stage apoptotic cells

Apoptotic cells are considered an important auto-antigenic source in diseases such as systemic lupus erythematosus (SLE). A human monoclonal antibody demonstrating exquisite specificity towards late-stage apoptotic cells was generated from an SLE patient. Polyreactive recognition of ribonucleoproteins Ro52 and Ro60 was observed. The antibody significantly diminished the phagocytosis of apoptotic cells and a concomitant decrease in transforming growth factor-beta (TGF-beta) secretion was observed. Light and heavy chain sequencing revealed the antibody to be in essentially germline configuration. Elicited anti-idiotypic antibodies bound distinct self-antigens and showed augmented reactivity towards apoptotic cells as well. Thus, near-germline encoded antibodies recognizing antigens externalized during the process of apoptosis can mediate a variety of potentially pathogenic effects; decreases in the phagocytic uptake of dying cells would constitute a disease-perpetuating event and stimulation of the idiotypic network could lead to intermolecular epitope spreading, increasing the range of molecular targets..

Comparison of Survival Rates after Bland Arterial Embolization and Ablation Versus Surgical Resection for Treating Solitary Hepatocellular Carcinoma up to 7 cm

PURPOSE

The vast majority of hepatocellular carcinomas (HCC) occur in patients with underlying liver dysfunction, making surgical resection available to only a subset of patients with adequate hepatic reserve. This study analyzes the authors' results with bland arterial embolization combined with radiofrequency ablation (RFA) or percutaneous ethanol injection (PEIT) compared with surgical resection for the treatment of solitary HCC up to 7 cm in size.

MATERIALS AND METHODS

A retrospective review of all patients undergoing either surgical resection or bland embolization combined with local ablation for solitary HCC between January 1996 and August 2002 was performed. Progression-free survival rate and overall survival rate were calculated by the Kaplan-Meier method.

RESULTS

There were 40 patients who underwent surgical resection and 33 patients who underwent embolization and ablation. Age, gender, and size of the treated lesion were not significantly different between the groups. The embolization/ablation group had more patients classified as Okuda stage II (P<.001). The surgical group had a longer median recurrence-free survival rate (53.1 vs 25.1 months). With a median follow-up of 23 months, the 1-, 3- and 5-year actuarial overall survival rates were 97%, 77%, and 56% for the embolization/ablation group and 81%, 70%, and 58% for the surgical group, respectively. There was no statistical difference in overall survival rates (P=.20).

CONCLUSIONS

Bland arterial embolization in combination with ablation is effective in treating solitary HCC lesions up to 7 cm and achieves similar overall survival rates to surgical resection in selected patients.

Factors associated with pneumothorax and pneumothorax requiring treatment after percutaneous lung biopsy in 443 consecutive patients

PURPOSE

To describe patient- and procedure-related factors associated with post-biopsy pneumothorax and those that require intervention.

MATERIALS AND METHODS

Patient and procedure data from all lung biopsies performed at a single center between January 2000 and July 2001 were recorded prospectively. Data included patient demographics, lesion size, lesion depth from skin, needle size, number of passes, patient position during biopsy, imaging method used (computed tomography/fluoroscopy), if sedation was used, occurrence of pneumothorax and whether the pneumothorax required treatment. Patient charts were retrospectively reviewed to determine smoking history, as well as previous ipsilateral chest surgery or radiation therapy. Univariate and multivariate analysis was performed, and P <.05 was considered significant.

RESULTS

Four-hundred fifty-three biopsies were performed on 443 patients. One-hundred six patients (23.4%) had post-biopsy pneumothorax and 31 patients (6.8% overall, 29.2% of pneumothorax group) required intervention. By univariate analysis, increased patient age, smaller lesion size, increased depth from skin, supine position, and no history of surgery were significant predictors of biopsy-related pneumothorax. However, only increased patient age, supine position, no history of ipsilateral surgery, and history of smoking were associated with pneumothorax that required intervention. By multivariate analysis, increased patient age, smaller lesion size, and no history of surgery predicted pneumothorax; supine position, history of smoking, and no history of ipsilateral surgery predicted which patients with pneumothorax would require treatment.

CONCLUSION

Independent risk factors for pneumothorax include increased patient age, smaller lesion size, and no history of surgery. Previous surgery and prone positioning during biopsy appear to provide a "protective effect" against clinically significant post-biopsy pneumothorax.

Regeneration from leaf protoplasts of Arabidopsis thaliana ecotype estland

Protoplasts (2 x 10(7)/g fresh wt) were isolated from leaves of A. thaliana ecotype estland, with a viability of more than 90%. Protoplasts cultured in calcium alginate beads or layers showed division while culture in liquid or agarose beads failed to elicit any division. Effect of culture density showed highest frequency of division occurring at 5 x 10(5) while no division was seen when cultured at a density of 5 x 10(4). Culture in MS medium resulted in higher division frequency and better sustenance of microcolonies as compared to B5 medium. Under optimized conditions, macrocolonies were formed at a frequency of 1.8%. Shoot regeneration was seen in 50% of microcalli transferred to shoot induction medium for regeneration. Shoots were rooted and plantlets transferred to pots. The plants produced flowers and were fertile.

Defining the learning curve for the Focused Abdominal Sonogram for Trauma (FAST) examination: implications for credentialing

Focused Abdominal Sonogram for Trauma (FAST) examination is being used increasingly for the torso evaluation of injured patients. In a controlled setting using peritoneal dialysis patients as models for injured patients with free fluid we hypothesized that more experienced providers would perform FAST with greater accuracy. Twelve fellow or attending level trauma surgeons, two radiologists, and one ultrasound technician were studied for their ability to detect intraperitoneal fluid (0-1600 cm3) in nine peritoneal dialysis patients with two different volumes of dialysate/patient. FAST experience with injured patients was defined as minimal (<30 patients examinations), moderate (30-100), or extensive (>100). All surgeons had participated in a didactic/practical course before the study. Test results were reported as "+" or "-" by the participant; "+" results were further quantified by volume. The sensitivity of those in the minimal-, moderate-, and extensive-experience to detect <1 L was 45, 87, and 100 per cent, respectively; the accuracy in detecting dialysate volume within 250 cm3 was 38, 63, and 90 per cent, respectively. In this controlled setting the accuracy of FAST particularly in diagnosing smaller volumes, as well as the ability to quantify volume, improves with experience. The learning curve for FAST starts to flatten out at 30 to 100 examinations. Training and credentialing policies should consider these findings to optimize patient care.

Safety and cost of low-molecular-weight heparin as bridging anticoagulant therapy in subacute cerebral ischemia

BACKGROUND AND PURPOSE

Anticoagulation with intravenous unfractionated heparin (IVUH) while awaiting therapeutic oral anticoagulant levels is a common practice in patients with acute and subacute cerebral ischemia. A promising alternative strategy is to use bridging subcutaneous low-molecular-weight heparin (LMWH), which may have a favorable risk-benefit profile compared with IVUH and may permit earlier discharge with completion of transition to warfarin therapy as an outpatient.

METHODS

A LMWH, enoxaparin 1 mg/kg BID, was used as bridging anticoagulation therapy in 24 consecutive patients admitted to a university stroke center in whom the treatment plan included transition from acute to chronic anticoagulation. The LMWH group was contrasted with the preceding 24 patients transitioned to warfarin with IVUH at the same center.

RESULTS

Fewer patients in the LMWH bridging therapy group experienced neurological worsening than in the IVUH bridging therapy group (2/24 versus 8/24; P:=0.033). Fewer total adverse events were noted in the LMWH group than in the IVUH cohort (3 versus 20; P:=0. 002). Fifteen of the 24 LMWH patients (62.5%) were discharged while still receiving LMWH and completed transition to warfarin as outpatients, receiving an average of 3.6 days of outpatient transitional therapy. In these 15 patients, use of LMWH was associated with a net savings of $2197 per patient.

CONCLUSIONS

In this pilot cohort with subacute cerebral ischemia, bridging LMWH appeared to be safer than bridging IVUH and was associated with reduced hospital stay and reduced total cost of care.

Oxidant-antioxidant status in acute and chronic renal failure

Present study was carried out to evaluate oxidant-antioxidant status and effect of hemodialysis in acute and chronic renal failure. Serum MDA levels increased while serum SOD found decreased significantly. This study indicates the existence and increased production of an oxidizing stress resulting from hemodialysis and disturbance in antioxidant enzyme system.