Technical performance of colonoscopy -- multicenter study in university and non-university centers of Romania

The aim of the paper was to evaluate the national availability of colonoscopy and the quality parameters of this procedure in our country.

MATERIAL AND METHOD

During a 6 months period (01.07- 31.12.2009), we performed a prospective multicenter study in which 76 centers were invited to respond to a questionnaire regarding colonoscopy, 39 centers agreeing to participate. We assessed: the number of colonoscopies, the number of total colonoscopies and the causes of incomplete colonoscopies.

RESULTS

During the study period, 16,083 colonoscopies were performed, 12,294 (76.4%) of them total colonoscopies. In 1,191 cases, stenosis was the cause of incomplete colonoscopy. If we consider this an objective reason for an incomplete colonoscopy, there were 12,294 total colonoscopies (82.4%). Comparing university centers with non-university ones, the proportion of total colonoscopies was 10,400/12,475 (83.4%) vs. 1,894/2,417 (78.4%) (p less then 0.0001). However, comparing the present study with previous ones, performed in 2003 and 2007, the proportion of total colonoscopies increased from 70.5% to 76.9% and 82.4% respectively (2003 vs. 2007 p less then 0.0001; 2007 vs. 2009 p less then 0.0001), while the quality difference between university and non-university hospitals persisted.

CONCLUSIONS

the quality of colonoscopy in Romania increased in the last 5 years, while the quality difference between university and non-university hospitals persisted.

Time-resolved MR venography of the pulmonary veins precatheter-based ablation for atrial fibrillation

PURPOSE

To evaluate time-resolved magnetic resonance angiography (TR-MRA) of the pulmonary venous circulation using the time-resolved angiography with interleaved stochastic trajectories (TWIST) method and compare it with the more commonly used conventional contrast-enhanced magnetic resonance angiography (CE-MRA) approach in atrial fibrillation patients referred for preablation pulmonary vein mapping.

MATERIALS AND METHODS

This study was approved by the Institutional Review Board. Twenty-six patients (15 males; age 59.6 ± 12.7 years) referred for preablation pulmonary vein mapping underwent both conventional CE-MRA and TR-MRA with TWIST. Imaging was performed on a 1.5 T (Magnetom Avanto, Siemens Healthcare, Erlangen, Germany) MRI scanner. Source partition and maximum intensity projection (MIP) images were evaluated retrospectively. For quantitative analysis, pulmonary vein ostium orthogonal dimensions were measured using double oblique multiplanar reformatting. The results were analyzed using paired t-tests, Lin's concordance correlation coefficient, and Bland-Altman plots. For qualitative analysis, both source partition images and MIP images were assessed by two observers (A.P. and M.G.). The presence of common ostiums or accessory veins was recorded and analyzed using unweighted Cohen's kappa. Pulmonary vein conspicuity was scored on a scale of 1-4 (1 = poor, 2 = fair, 3 = good, 4 = excellent) and analyzed using paired t-tests, intraclass correlation coefficients, and quadratic weighted kappa statistics.

RESULTS

Orthogonal venous diameters were comparable for both TR-MRA and conventional CE-MRA (1.34 ± 0.37 vs. 1.38 cm ± 0.36, respectively). Results of paired t-tests, Lin's concordance correlation coefficient, and Bland-Altman analysis revealed relatively close comparison between methods. The magnitude of the mean difference for any of the statistical comparisons did not exceed 0.10 cm. The visualization of variant pulmonary vein anatomy was very similar for both techniques. Agreement between techniques was determined to be "good" to "very good" (κ = 0.78-0.85). Conspicuity scores for each pulmonary vein were also very close. Paired t-tests, intraclass correlation coefficients, and quadratic weighted kappa statistics all revealed strong agreement between methods.

CONCLUSION

TR-MRA using TWIST produces comparable anatomic images and pulmonary venous dimensions to the more widely used CE-MRA technique. Additionally, the TWIST technique improves arterio-venous separation, does not need exact bolus timing, requires less gadolinium, and gives additional information on vein perfusion.

The role of capsule endoscopy in the detection of small bowel disease

Videocapsule endoscopy (VCE) can identify lesions in the small bowel which would otherwise be hard to detect. We have selected 53 patients with digestive symptoms in which upper and lower endoscopy had provided no findings. Patients were classified into three groups, based on their main indication for VCE exploration: group one--obscure gastrointestinal bleeding (OGIB); group two--unspecific abdominal symptoms; group 3--monitoring of a prior known pathology. We found that VCE has high predictive values, sensibility and specificity in the diagnosis of OGIB. VCE was also useful in the detection and extent evaluation of lesions in Crohn's and celiac disease. VCE is also able to detect tumors of the small bowel with sufficient accuracy, and can be used to monitor patients with hereditary pre-malignant diseases such as FAP. There were few light adverse effects and no major complications. We conclude that VCE is a safe and effective procedure for the detection of small bowel lesions.

Transient partial response to sorafenib treatment in an adolescent patient with MEN2B syndrome and end-stage medullary thyroid carcinoma

Metastatic medullary thyroid carcinoma (MTC) is an aggressive malignancy with an extremely poor prognosis. Currently no effective conventional systemic therapies exist to treat pediatric MTC. We describe an adolescent female with newly diagnosed MEN2B syndrome who presented with advanced stage metastatic MTC and demonstrated a partial transient response to sorafenib monotherapy. This clinical result supports further research into the use of sorafenib in the treatment of pediatric MTC.

Thyroid stiffness assessment by acoustic radiation force impulse elastography (ARFI)

PURPOSE

To evaluate and compare the values of thyroid tissue elasticity in subjects without known thyroid pathology, in patients with Graves' disease and with chronic autoimmune thyroiditis (CAT).

PATIENTS AND METHODS

We performed a prospective study that included 74 subjects, 23 without thyroid pathology, 29 with Graves' disease and 22 with CAT (diagnosed by specific tests). In all patients, 10 elastographic measurements were performed in the right thyroid lobe (RTL) and 10 in the left thyroid lobe (LTL) using a 2-6 MHz convex probe. Median values were calculated for each thyroid lobe, measured in meters/second (m/sec). We calculated a mean ARFI value from measurements made in the RTL and LTL.

RESULTS

Thyroid stiffness was statistically significant lower in normal subjects vs. those with Graves' disease (2.07±0.44 m/sec vs. 2.82±0.47 m/sec, p<0.001) and with CAT (2.07±0.44 m/sec vs. 2.49±0.48 m/sec, p=0.004). We also found a statistically significant difference between subjects without thyroid pathology and those with autoimmune thyroid pathology (Graves' disease and CAT) (2.07±0.44 m/sec vs. 2.68±0.50 m/sec, p<0.001).

CONCLUSION

ARFI seems to be a useful method for the evaluation of diffuse thyroid gland pathology and is able to predict with sufficient accuracy the presence of thyroid diffuse diseases (AUROC=0.80).

What did we learn from the first 3,459 cases of liver stiffness measurement by transient elastography (FibroScan®)?

PURPOSE

Chronic viral hepatopathies can be evaluated through invasive or noninvasive methods. The aim of this paper was to assess the indications and results of transient elastographic (TE) evaluation of the liver in patients with chronic viral hepatitis and cirrhosis.

MATERIALS AND METHODS

We retrospectively assessed all the liver stiffness measurements (LSM) (FibroScan®) performed over a two-year period (2007 - 2009).

RESULTS

3,459 TE evaluations were made mainly for the assessment of: HCV hepatitis, HBV infection (chronic hepatitis and inactive HBV carriers), biviral hepatitis (B + C or B + D), cirrhosis and in 176 normal subjects (to establish the normal values of LSM). From the 3,459 FS evaluations, we could not obtain valid LSM in 183 cases (5.3 %). 93.9 % of the patients in the failure group were overweight (BMI > 25 kg/m²). In 527 cases (16 %) the SR (success rate = number of valid measurements/total number of measurements) was < 60 %. TE reproducibility was analyzed in 287 cases. The ICCs for the three operators were 0.985, 0.949, and 0.874 respectively, and the overall ICC was 0.982. 596 cases of cirrhosis were evaluated. A cut-off value of 23.3kPa was found to predict the presence of at least grade 2 esophageal varices.

CONCLUSION

LSM by means of TE is a promising noninvasive evaluation method, which can be used in numerous clinical situations, some in which its value is well established (suspicion of LC, predicting significant fibrosis) and some in which its value is less known (HBV chronic hepatitis, inactive HBV carriers or severity of portal hypertension).

Acoustic radiation force impulse elastography as compared to transient elastography and liver biopsy in patients with chronic hepatopathies

PURPOSE

To compare two methods of noninvasive assessment: transient elastography (TE) and acoustic radiation force impulse elastography (ARFI).

PATIENTS AND METHODS

Our study included 114 subjects: 38 healthy volunteers, (considered to have no fibrosis - F 0) and 76 patients with chronic liver disease: 53 who had undergone liver biopsy (LB) (7 with F 1, 24 with F 2, 22 with F 3 Metavir) and 23 previously diagnosed with cirrhosis (F4 Metavir). In each patient we performed a liver stiffness measurement by means of TE and ARFI. ARFI (shear wave velocity quantification) was performed at 3 points: at 0 - 1 cm, at 1 - 2 cm and at 2 - 3 cm under the capsule. For each depth, 5 valid measurements were made, and a median value was calculated, measured in m/sec.

RESULTS

A direct, strong, linear correlation (Spearman rho = 0.848) was found between TE and the stage of fibrosis (p < 0.001). A significant, direct correlation was found between ARFI measurements made 1 - 2 cm and 2 - 3 cm below the liver capsule and the severity of fibrosis (rho = 0.675 and 0.714 respectively). The subcapsularly measured ARFI values showed a poor correlation with fibrosis (rho = 0.469). The best test for predicting significant fibrosis (F ≥ 2) was TE, with the area under receiver-operating characteristic curve (AUROC) 0.908, significantly larger than the AUROCs for ARFI. If only ARFI is considered, measurements made 1 - 2 and 2 - 3 cm below the capsule have the best predictive value, with AUROCs not significantly different from each other (0.767 and 0.731, respectively). For predicting fibrosis (F > 0), TE had the best predictive value: optimized cut-off 5.65 kPa (AUROC -0.898). For ARFI, the cut-offs were: 1.4 m/sec, AUROC -0.747 (1 - 2 cm), and 1.26 m/sec AUROC -0.721 (2 - 3 cm). For predicting cirrhosis (F = 4 Metavir), the optimized cut-offs were: TE -12.9 kPa (AUROC -0.994); ARFI - 1.78 m/sec for measurements made 2 - 3 cm below the capsule, AUROC - 0.951.

CONCLUSION

At present, liver elasticity evaluation by means of ARFI is not superior to TE for the assessment of liver fibrosis. For ARFI, the most reliable results are obtained if measurements are made 1 - 2 and 2 - 3 cm below the liver capsule. ARFI is an accurate test for the diagnosis of cirrhosis.

A carbon nanotube oscillator as a surface profiling device

A double wall carbon nanotube oscillator near an infinite surface with the nanotube axis perpendicular to the surface is investigated. The oscillatory motion is governed in part by the van der Waals forces in the system, and we use the Lennard-Jones approximation for their calculation. In addition, friction losses due to the proximity of the oscillating nanotube near the infinite surface are taken into account using a phenomenological model. Newton's equation is solved and the oscillatory motion is studied as a function of the nanotube-surface distance, the nanotube length, and the initial extrusion of the moving nanotube. A practical device for surface profiling is also proposed.

Changes in prescribed doses for the Seattle neutron therapy system

From the beginning of the neutron therapy program at the University of Washington Medical Center, the neutron dose distribution in tissue has been calculated using an in-house treatment planning system called PRISM. In order to increase the accuracy of the absorbed dose calculations, two main improvements were made to the PRISM treatment planning system: (a) the algorithm was changed by the addition of an analytical expression of the central axis wedge factor dependence with field size and depth developed at UWMC. Older versions of the treatment-planning algorithm used a constant central axis wedge factor; (b) a complete newly commissioned set of measured data was introduced in the latest version of PRISM. The new version of the PRISM algorithm allowed for the use of the wedge profiles measured at different depths instead of one wedge profile measured at one depth. The comparison of the absorbed dose calculations using the old and the improved algorithm showed discrepancies mainly due to the missing central axis wedge factor dependence with field size and depth and due to the absence of the wedge profiles at depths different from 10 cm. This study concludes that the previously reported prescribed doses for neutron therapy should be changed.

Influence of bilayer period on the characteristics of nanometre-scale ZrN/TiAIN multilayers

In the last decade, considerable research effort was directed to the deposition of multilayer films with layer thicknesses in the nanometer range (superlattice coatings), in order to increase the performance of various cutting tools and machine parts. The goal of the present work was to investigate the main microstructural, mechanical and wear resistance characteristics of a superlattice coating, consisting of alternate multilayer ZrN/TiAIN films, with various bilayer periods (5 / 20 nm). The coatings were deposited by the cathodic arc method on Si, plain carbon steel and high speed steel substrates to be used as wear resistance surfaces. The multilayer structures were prepared by using shutters placed in front of each cathode (Zr and Ti+Al). The characteristics of multilayer structures (elemental and phase composition, texture, Vickers microhardness, thickness, adhesion, and wear resistance) were determined by using various techniques (AES, XPS, XRD, microhardness measurements, scratch, and tribological tests). A comparison with the properties of ZrN and TiAIN single-layer coatings was carried out.

Venous circulation of the bronchial wall

Bronchial supply plays an important role in both the protecting mechanisms and the pathogenic ones of many chronic inflammatory, infections or ischemic diseases of the lung. However, little is known regarding the bronchial supply development; the appearance of the connections to the functional pulmonary supply; the territory supplied by the bronchial veins. In this study, we follow the distribution of the pulmonary veins branches at the level of the subcarinal airways and their relationship to the bronchial veins in the human lungs. For studying the venous supply of the airways, we used the corrosion and colored gelatin injection methods followed by microdissection by means of an operator microscope. Venous circulation of the intrapulmonary airways is mainly tributary to the pulmonary vein branches. Venous circulation of the extrapulmonary airways is tributary to both the pulmonary and the bronchial veins. Taking into account the difference of sizes, we consider that, under physiologic conditions, the main venous collector is represented by the pulmonary veins.

Laparoscopic hand-assisted adrenalectomy for a 20 cm benign tumor

Since its introduction in 1992, laparoscopic adrenalectomy (LA) has become the technique of choice in the surgical treatment of both secreting or non-secreting benign adrenal pathology. Although traditionally, laparoscopic approach was recommended only for tumor sizes less than 6-8 cm--as larger tumors were known to have an increased risk of malignancy--the currently growing experience and improvement of surgical techniques has allowed for an extension of the therapeutic indication, as shown by the recent case report of LA use for a benign 22 cm tumor (1). We report the case of a young patient operated in our Department for a benign 20 cm adrenal tumor for which laparoscopic "hand-assisted" adrenalectomy yielded a good postoperative outcome and minimal complications.

Rupture de tendons fléchisseurs sur plaque antérieure après fracture du radius distal

We report four cases of flexor tendon ruptures which occurred after distal radial fracture and reviewed the 25 other cases reported in the literature since 1932. Analysis of these 29 cases disclosed the causes of these ruptures. A deformed callus after distal radial fracture or presence of an anterior osteosynthesis plate can under certain conditions lead to secondary flexor tendon tears. It was also found that tears of the flexor pollicis longus rupture predominate, followed by injury to the flexor digitorum profundis and superficialis of the index finger. Other tendons have only been involved in only a few cases. In order to avoid this complication, we propose systematic removal of anterior plates or secondary replacement if the reduction is not totally anatomic. Surgeons should recall the importance of anatomic reduction of distal radial fractures.

Variation of cephalometric parameters in peri-puberty cephalometric aspects of sexual dymorphism

The data regarding the global and segmental growth and development of the child are useful in pluri-disciplinary studies which view the human body as an entity where the biological aspects (both the normal and the pathological ones) interlace with the socio-cultural ones, thus offering the possibility to any specialist in the field of humanities and morphological studies to cover a wide range in contemporary anthropological research. The development of the skull takes place in two active stages separated by a stage of relative quiet during the age of seven and puberty when the skull has a dolicocephalic aspect. During the second stage of active growth (which starts with puberty) there is a transversal growth of the basis of the cranium followed by an anteroposterior growth. The degree of gender-related differences as far as the dimensions and proportions of the skull are concerned vary greatly according to race, therefore we may say that general ethnic differences are more pronounced than gender-related ones.