External Fixator Usage and Delayed MRI Scans: A National Survey Study.

OBJECTIVE: To report the current state of institutional protocols regarding the use of MRI in patients with external fixation devices (EFDs) in the United States. DESIGN: National Survey Study. PARTICIPANTS: Practicing orthopaedic surgeons frequenting the Orthopaedic Trauma Association website were invited to participate in this study. RESULTS: Sixty-two eligible orthopaedic surgeons completed the survey. No respondents reported any known harmful complications of MRI use with an EFD. Eight respondents (13%) reported at least one early scan termination because of mild warmth or vibration without any lasting complications. Fifty-six respondents (90%) reported delays to care related to MRI-EFD compatibility labeling, and 27 respondents (48%) reported delayed MRI scans in every patient with an EFD who needed one. Twenty-six surgeons (42%) had modified their practice in some way in response to these barriers. Examples include delaying EFD placement until after MRI, relying on CT arthrograms over MRI for surgical planning, and taking patients to the operating room to remove EFDs temporarily and then replace them. Nineteen respondents (31%) had developed formal protocols to address this issue, but having a written protocol was not associated with any decrease in delays ( P = 0.119). Eighty-nine percent of respondents thought there was a need for a national consensus guideline on this issue. CONCLUSION: Despite no previous reports of harmful complications, MRI utilization is frequently delayed or prevented in patients with EFDs in place. This is a pervasive problem nationally, which persists despite the implementation of written institutional protocols. Additional research is needed, potentially at the national level, to address this common issue. LEVEL OF EVIDENCE: V.

What is "safety"?: Lethal means counseling as a cross-cultural communication.

U.S. suicide rates have risen every year over the past two decades with self-directed firearm use as the method accounting for the highest proportion of deaths. This pattern is particularly pronounced among veterans and members of the U.S. Armed Forces. The numerical burden of firearm-related suicide accompanied by characteristics of self-directed firearm injury have motivated the development of lethal means safety initiatives focused on firearms. Simultaneously, research has sought to characterize patterns of firearm ownership and use among veterans as well as optimal strategies for clinicians to deliver suicide prevention messages to firearm owners. Increasingly, findings from research have been understood as cultural factors that warrant greater attention to improve the quality of lethal means counseling. Here, we review and interpret selected research on cultural aspects of firearm ownership and suggest that cultural differences between health care practitioners and firearm owners may result in health care practitioners delivering clinical interventions that are broadly divergent from perspectives within the cultural frameworks of firearm owners. We follow by organizing these cultural factors into existing frameworks of cultural competency training as a basis for developing curriculum for health care practitioners to improve clinical care.

Percutaneous treatment of hepatocellular carcinoma in patients with cirrhosis: a comparison of the safety of cryoablation and radiofrequency ablation.

PURPOSE: To compare the safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis. MATERIALS AND METHODS: This retrospective HIPAA-compliant study received institutional review board approval. Forty-two adult patients with cirrhosis underwent image-guided percutaneous ablation of hepatocellular carcinoma from 2003 to 2011. Twenty-five patients underwent 33 cryoablation procedures to treat 39 tumors, and 22 underwent 30 radiofrequency ablation procedures to treat 39 tumors. Five patients underwent both cryoablation and radiofrequency ablation procedures. Complication rates and severity per procedure were compared between the ablation groups. Potential confounding patient, procedure, and tumor-related variables were also compared. Statistical analyses included Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests. Two-sided P-values <0.05 were considered significant. RESULTS: The overall complication rates, 13 (39.4%) of 33 cryoablation procedures versus eight (26.7%) of 30 radiofrequency ablation procedures and severe/fatal complication rates, two (6.1%) of 33 cryoablation procedures versus one (3.3%) of 30 radiofrequency ablation procedures, were not significantly different between the ablation groups (both P=0.26). Severe complications included pneumothoraces requiring chest tube insertion during two cryoablation procedures. One death occurred within 90 days of a radiofrequency ablation procedure; all other complications were managed successfully. CONCLUSION: No significant difference was seen in the overall safety of image-guided percutaneous cryoablation and radiofrequency ablation in the treatment of hepatocellular carcinoma in patients with cirrhosis.

The effects of electronic polarization on water adsorption in metal-organic frameworks: H2O in MIL-53(Cr).

The effects of electronic polarization on the adsorption of water in the MIL-53(Cr) metal-organic framework are investigated using molecular dynamics simulations. For this purpose a fully polarizable force field for MIL-53(Cr) was developed which is compatible with the ab initio-based TTM3-F water model. The analysis of the spatial distributions of the water molecules within the MIL-53(Cr) nanopores calculated as a function of loading indicates that polarization effects play an important role in the formation of hydrogen bonds between the water molecules and the hydroxyl groups of the framework. As a result, large qualitative differences are found between the radial distribution functions calculated with non-polarizable and polarizable force fields. The present analysis suggests that polarization effects can significantly impact molecular adsorption in metal-organic frameworks under hydrated conditions.

Role of secondary sialic acid binding sites in influenza N1 neuraminidase.

Within influenza viral particles, the intricate balance between host cell binding and sialic acid receptor destruction is carefully maintained by the hemagglutinin (HA) and neuraminidase (NA) glycoproteins, respectively. A major outstanding question in influenza biology is the function of a secondary sialic acid binding site on the NA enzyme. Through a series of Brownian dynamics (BD) simulations of the avian N1, human pandemic N2, and currently circulating pandemic (H1)N1 enzymes, we have probed the role of this secondary sialic acid binding site in the avian N1 subtype. Our results suggest that electrostatic interactions at the secondary and primary sites in avian NA may play a key role in the recognition process of the sialic acid receptors and catalytic efficiency of NA. This secondary site appears to facilitate the formation of complexes with the NA protein and the sialic acid receptors, as well as provide HA activity to a lesser extent. Moreover, this site is able to steer inhibitor binding as well, albeit with reduced capacity in N1, and may have potential implications for drug resistance or optimal inhibitor design. Although the secondary sialic acid binding site has previously been shown to be nonconserved in swine NA strains, our investigations of the currently circulating pandemic H1N1 strain of swine origin appears to have retained some of the key features of the secondary sialic acid binding site. Our results indicate possible lowered HA activity for this secondary sialic acid site, which may be an important event in the emergence of the current pandemic strain.

Do nonspecific deep corticomedullary sutures performed during partial nephrectomy adequately control major vascular and collecting system injury?

OBJECTIVE: To critically evaluate the effectiveness of placing nonspecific deep corticomedullary sutures in the setting of major vascular and collecting system injury during laparoscopic partial nephrectomy (LPN). We also aimed to evaluate the incidence of ischaemic injury to the remaining renal remnant because of these sutures, as many laparoscopic centres have adopted this practice. MATERIALS AND METHODS: We performed open PN on eight porcine kidneys. Both the artery and vein were clamped. The ureter was transected and tied around an angiocatheter for evaluating collecting system integrity both before and after corticomedullary suturing. The renal artery was cannulated for angiography before and after the corticomedullary suturing. The rate of bleeding was also assessed before and after corticomedullary suturing. RESULTS: There was marked arterial bleeding and large collecting system injury induced in all kidneys. Two of the eight renal units continued to have significant arterial bleeding after the deep corticomedullary sutures were placed. All of the eight units had at least a small urinary leak after suturing, with three having medium-to-large leaks. In four of the renal units, there were major segmental vessels occluded by the sutures, as detected by angiography. CONCLUSIONS: The practice of placing nonspecific deep corticomedullary sutures, during PN, may not adequately control major vascular and collecting system injury. In addition, segmental vessels supplying remnant renal tissue are often affected; thereby further compromising function because of devascularization. The search for the best technique for LPN continues.

Outside CT imaging among emergency department transfer patients.

PURPOSE: The aim of this study was to characterize the quantity and types of outside computed tomographic (CT) examinations submitted for reinterpretation among emergency department (ED) transfers to a tertiary care, level I trauma, academic medical center and the frequency of and reasons for repeat imaging. METHODS: Reinterpretation requests for outside CT studies accompanying ED transfer patients over a 4-month period were prospectively audited. Clinicians completed forms specifying type of CT study, outside report availability, interpretational discrepancies, repeat imaging requests, and reasons for repeat imaging. RESULTS: A total of 425 CT studies were reviewed among 255 transfer patients, with a mean of 2.8 examinations (range, 0-16) on 1.7 patients (range, 0-8) per day. The patients' mean age was 59 years, and 57% were male. The clinicians reported no outside verbal or written reports for 16% of patients. Interpretational discrepancies were noted in 12% of those with outside reports. Repeat scans might have been avoided in as many as 25% of rescanned patients (35% of repeat examinations) because they were performed solely for imaging or information technology reasons (inadequate imaging, compact disc inoperability, or unavailable images within the hospital's picture archiving and communication system). Rescanned trauma patients in particular had a high per patient rate (32%) of potentially avoidable reasons, with a lower rate (11%) in nontrauma patients. CONCLUSION: Outside CT imaging in ED transfers adds workload and resource requirements for receiving institutions. A communication gap exists between transferring and receiving institutions, and interpretational discrepancies are common. Process improvement measures are suggested that might reduce the substantial rates of potentially avoidable reimaging.

Geographic variations in the use of medical and surgical therapies for benign prostatic hyperplasia.

PURPOSE: Patients with BPH have several treatment options. Little is known about geographic variations in surgical rates for BPH and the market relationships to medical therapy, health resources and sociodemographic factors. MATERIALS AND METHODS: We conducted a cross-sectional study using administrative data from 5 states in 2000. Rates of surgical and medical therapy were calculated per 100,000 men 55 years old or older. Main outcome measures were county level weighted coefficient of variation and systematic component of variation in therapy rates, as well as surgery rates as a function of medication dispensing rates, health care resources and sociodemographic characteristics. RESULTS: North Carolina had the lowest surgery rates (26.3 minimally invasive procedures and 332.1 invasive surgeries per 100,000) and finasteride dispensing rates (503.5 per 100,000). Overall rates of medical therapy were 5 times higher than surgery rates. Geographic variations in surgical and medical therapy rates were significant for each state, and North Carolina had the greatest variation. An increase of 11.6 per 100,000 (95% CI, 6.5-55.8) in annual county level finasteride dispensing would be associated with a decrease in the surgery rate of 1 per 100,000, controlling for other variables. CONCLUSIONS: There is significant systematic variation in rates of surgical and medical therapy for BPH at county and state levels. The relationship between finasteride and surgery in randomized clinical trials is generalizable to the marketplace. Finasteride rates are inversely related to surgery rates, and tamsulosin rates are positively associated with surgery rates. Surgery rates are not significantly associated with urologists per capita.

Controlled survival study of the effects of Tisseel or a combination of FloSeal and Tisseel on major vascular injury and major collecting-system injury during partial nephrectomy in a porcine model.

PURPOSE: We report the results of a controlled survival study in a porcine model investigating Tisseel or a combination of FloSeal and Tisseel in dealing with vascular and collecting-system injury during partial nephrectomy. MATERIALS AND METHODS: We performed an open right lower-pole partial nephrectomy on 15 large female pigs. The defect was repaired using standard open techniques (N = 5; controls), Tisseel only (N = 6; group I), or FloSeal followed by Tisseel (N = 4; group II). A Jackson-Pratt drain was placed. Nephrectomy and retrograde pyelography were performed at 1 week. RESULTS: Operative times were shorter in both study groups, achieving statistical significance in group I (P = 0.008). Warm-ischemia times were significantly improved in both study groups (P = 0.029 and P = 0.00005 in groups I and II, respectively). Time to hemostasis was significantly shorter in group II only (P = 0.002) but approached significance in Group I as well (P = 0.09). Estimated blood loss was not significantly different from the controls in either group. When Tisseel was placed alone after hilar control, hematoma formation under the Tisseel was noted on release of the hilar clamp. After 1 week, there was one urinoma and three urine leaks in the control group. In group I, there was one urinoma and four urine leaks, and there was only one urine leak and no urinomas in group II. There were no hematomas in any of the groups. CONCLUSIONS: Tisseel alone is not adequate for either hemostasis or management of major collecting-system injury. FloSeal capped with Tisseel appears sufficient to control major vascular and collecting-system injuries without adjunctive surgical measures. A proposed technique for laparoscopic partial nephrectomy without reconstructive techniques is presented that warrants clinical study.

Location and etiology of flexible and semirigid ureteroscope damage.

OBJECTIVES: To perform an analysis of currently available manufacturer data regarding the character of ureteroscope damage. The high costs associated with the repair of flexible and semirigid ureteroscopes are well documented. Increased knowledge of the etiology of ureteroscope damage should aid urologists in prolonging the lives of these delicate instruments. METHODS: We requested data from the four major ureteroscope manufacturers (ACMI, Olympus America, Karl Storz, and Richard Wolf) on the types, speculated causes, costs, and frequency of ureteroscope damage. The results were tabulated in a blinded fashion and analyzed for trends. We then formulated guidelines that could be applied by practicing urologists. RESULTS: For both flexible and semirigid ureteroscopes, the frequency of repair increased with decreasing ureteroscope diameter and increasing instrument length. The cost of the repair was generally greater for flexible ureteroscopes (mean 4597 dollars) than for semirigid ureteroscopes (mean 2437 dollars). The major causes of flexible ureteroscope damage were working channel damage from laser burn or instrument passage and extreme scope deflection with an indwelling instrument. The primary reasons for semirigid ureteroscope repair included overtorquing and improper handling in the operating room and during sterile processing. CONCLUSIONS: Urologists can minimize the repair costs of flexible and semirigid ureteroscopes by taking precautions to eliminate laser fiber-induced damage and by avoiding overdeflection. Improved storage and handling of these instruments is also necessary. Although small-diameter ureteroscopes are favorable because of their increased mobility and ease of passage, physician and staff awareness of their increased fragility is vital in maximizing the longevity of these commonly used instruments.