Percutaneous trans-hepatic bilateral biliary stenting in Bismuth IV malignant obstruction.

AIM: To investigate the clinical efficiency of percutaneous trans-hepatic bilateral biliary metallic stenting for the management of Bismuth IV malignant obstructive disease. METHODS: Our hospital's database was searched for all patients suffering from the inoperable malignant biliary obstruction Bismuth IV, and treated with percutaneous bilateral trans-hepatic placement of self-expandable nitinol stents. The indication for percutaneous stenting was an inoperable, malignant, symptomatic, biliary obstruction. An un-correctable coagulation disorder was the only absolute contra-indication for treatment. Bismuth grading was performed using magnetic resonance cholangiopancreatography. Computed tomography evaluation of the lesion and the dilatation status of the biliary tree was always performed prior to the procedure. All procedures were performed under conscious sedation. A single trans-hepatic track technique was preferred (T-configuration stenting) and a second, contra-lateral trans-hepatic track (Y-configuration stenting) was used only in cases of inability to access the contra-lateral lobe using a single track technique. The study's primary endpoints were clinical success, defined as a decrease in bilirubin levels within 10 d and patient survival rates. Secondary endpoints included peri-procedural complications, primary and secondary patency rates. RESULTS: A total of 35 patients (18 female, 51.4%) with a mean age 69 ± 13 years (range 33-88) were included in the study. The procedures were performed between March 2000 and June 2008 and mean time follow-up was 13.5 ± 22.0 mo (range 0-96). The underlying malignant disease was cholangiocarcinoma (n = 10), hepatocellular carcinoma (n = 9), pancreatic carcinoma (n = 5), gastric cancer (n = 2), bile duct tumor (n = 2), colorectal cancer (n = 2), gallbladder carcinoma (n = 2), lung cancer (n = 1), breast cancer (n = 1) or non-Hodgkin lymphoma (n = 1). In all cases, various self-expandable bare metal stents with diameters ranging from 7 to 10 mm were used. Stents were placed in Y-configuration in 24/35 cases (68.6%) using two stents in 12/24 patients and three stents in 12/24 cases (50%). A T-configuration stent placement was performed in 11/35 patients (31.4%), using two stents in 4/11 cases (36.4%) and three stents in 7/11 cases (63.6%). Follow-up was available in all patients (35/35). Patient survival ranged from 0 to 1763 d and the mean survival time was 168 d. Clinical success rate was 77.1% (27/35 cases), and peri-procedural mortality rate was 5.7% (2/35 patients). Biliary re-obstruction due to stent occlusion occurred in 25.7% of the cases (9/35 patients), while in 7/11 (63.6%) one additional percutaneous re-intervention due to stent occlusion resulting in clinical relapse of symptomatology was successfully performed. In the remaining 4/11 patients (36.4%) more than 1 additional reintervention was performed. The median decrease of total serum bilirubin was 60.5% and occurred in 81.8% of the cases (27/33 patients). The median primary and secondary patency was 105 (range 0-719) and 181 d (range 5-1763), respectively. According to the Kaplan-Meyer survival analysis, the estimated survival rate was 73.5%, 47.1% and 26.1% at 1, 6 and 12 mo respectively, while the 8-year survival rate was 4.9%. Major and minor complication rates were 5.7% (2/35 patients) and 17.1% (6/35 patients), respectively. CONCLUSION: Percutaneous bilateral biliary stenting is a safe and clinically effective palliative approach in patients suffering from Bismuth IV malignant obstruction.

Treatment of infrainguinal thromboembolic complications during peripheral endovascular procedures with AngioJet rheolytic thrombectomy, intraoperative thrombolysis, and selective stenting.

OBJECTIVE: This study investigated the safety and effectiveness of the infrainguinal use of the AngioJet rheolytic mechanical thrombectomy system (Possis Medical, Minneapolis, Minn) for the treatment of acute infrainguinal thromboembolism occurring during lower limb revascularization procedures. METHODS: For the interval between January 2000 and January 2011, our hospital's database was meticulously searched for all patients with acute thromboembolism that occurred during lower limb angioplasty, with or without stenting procedures, who were treated with infrainguinal AngioJet thrombectomy. Baseline patient demographics and procedural details were analyzed. Primary end points included technical success, defined as the complete revascularization of the acutely occluded vessel; clinical success, defined as the absence of death or amputation ≤ 60 days; and procedure-related complication. Secondary end points included embolized vessel primary patency and overall patient survival. RESULTS: During this 12-year period, 3147 peripheral percutaneous procedures of angioplasty, with or without stenting, were performed in our department. Intraoperative, clinically, and angiographically evident thromboembolism occurred in 18 of 3147 procedures (0.57%), and 14 (77.7%) were managed using the AngioJet thrombectomy system. In total, 22 arteries were treated (13 infrapopliteal, 3 femoropopliteal, and 6 popliteal arteries). All patients had a completion angiogram for the assessment of the runoff vessels' status. Technical and clinical success occurred in 13 of 14 (92.8%). Adjunctive local thrombolysis or clot trapping, or both, with stenting was used in 64.3% and 42.8% of the procedures, respectively. Mean time follow-up was 38.1 ± 49.0 months. The 1-year embolized vessel primary patency rate was 50.9%, and the survival rate was 53.5% up to 11.5 years of follow-up, as estimated by Kaplan-Meier analysis. The 1-year limb salvage rate was 92.3%. There were no procedure-related minor amputations and one (7.1%) procedure-related major above-knee amputation. CONCLUSIONS: The use of AngioJet rheolytic thrombectomy and adjunctive local thrombolysis or stenting, or both, under filter protection, is safe and effective for the management of severe thromboembolic complications occurring in the femoropopliteal and infrapopliteal arteries during peripheral endovascular procedures.

Coronary artery calcium detection using flat panel digital cinefluoroscopy: comparison to coronary artery calcium score assessed with multiple detector computerized tomography.

BACKGROUND: The diagnostic accuracy of flat panel digital detector (FPDD) cinefluoroscopy for coronary artery calcium (CAC) detection, compared to multiple detector computed tomography (MDCT), is not known. METHODS: CAC was assessed by FPDD cinefluoroscopy (graded as 0,1, 2 and 3) and calcium score (CACS) was determined by MDCT in 151 asymptomatic individuals of low to intermediate cardiovascular risk, 40-60 years old (mean age 53.1 ± 7.4, men 76.5%). RESULTS: CAC was detected by MDCT and cinefluoroscopy in 79 (52.3%) and 69 (45.7%) of cases respectively. Agreement between MDCT and cinefluoroscopy was 77.5% (weighted kappa coefficient 0.75). Cinefluoroscopy was able to detect CAC in 50% of subjects with minimal CACS (<10). For CACS=0, area under the curve (AUC) was 0.89 (95% CI 0.83-0.93, p=0.0001) with sensitivity 82.3% and specificity 94.4%. For CACS=10, AUC was 0.91 (95% CI 0.86-0.95, p=0.0001) with sensitivity 91.8% and specificity 85.6%. For CACS=400, AUC was 0.97 (95% CI 0.94-0.99, p=0.0001) with sensitivity 100% and specificity 88.7%. The effective radiation dose was 1.8 ± 0.09 mSv for CT and 0.26 ± 0.13 mSv for cinefluoroscopy. CONCLUSIONS: Cinefluoroscopy performed with 'state-of-the art' FPDD technology has an excellent diagnostic accuracy compared to the 'gold standard' MDCT for CAC detection in middle aged, low to intermediate cardiovascular risk, asymptomatic individuals, with the advantage of lower radiation exposure.

Endovascular treatment of visceral aneurysms and pseudoaneurysms: long-term outcomes from a multicenter European study.

PURPOSE: To investigate the percutaneous endovascular management of visceral aneurysms (VA) and visceral pseudoaneurysms (VPA) treated in three European interventional radiology departments. METHODS: Patient archives from the department's databases were examined and retrospectively analyzed. Patients diagnosed between 2000 and 2010 with VA and/or VPA, confirmed by computed tomography angiography, magnetic resonance angiography, or digital subtraction angiography and treated exclusively with percutaneous endovascular methods, were included in the study. The study's primary end points were procedural technical success, target lesion reintervention rate, and periprocedural mortality rate. Secondary end points included major and minor complications rates. RESULTS: The medical records of 54 patients (41 male, mean age 55 ± 18.1 years) with 58 VAs or VPAs and treated with various percutaneous endovascular therapeutic modalities were analyzed. In total, 21 VAs (mean diameter 49.4 ± 21 mm, range 20-100 mm) and 37 VPAs (mean diameter 25.1 ± 14.6 mm, range 8-60 mm) were treated. Procedural technical success was achieved in 100% of the cases, while target lesion reintervention rate was 6.1% (2 of 33) and 14.2% (3 of 21) in the VPA and VA groups, respectively. Mean clinical follow-up period was 19.1 ± 21.4 months. Overall periprocedural mortality rate was 3% (1 of 33) in the VPA group and 0% (0 of 21) in the VA group. CONCLUSION: Percutaneous endovascular treatment of VAs and VPAs is safe and effective with low morbidity and mortality. There is a small but significant reintervention rate, particularly for true aneurysms; dedicated follow-up imaging is recommended. Successful aneurysm exclusion was achieved in all cases with a second procedure.

Percutaneous minimally invasive management of iatrogenic ureteral injuries.

PURPOSE: To present experience with the percutaneous management of iatrogenic ureteral injuries. PATIENTS AND METHODS: Eighteen women and six men with a mean age of 59.3 years (range 33-80 years) received a diagnosis of ureteral injury sustained during gynecologic, urologic, and general surgical procedures. In a total of 25 injured ureters, 12 had interruption of continuity of their lumen, 10 were associated with contrast extravasation, and 3 were related to both. A standard percutaneous nephrostomy tract was established on the side of the afflicted kidney. Combined use of hydrophilic guidewires and balloon dilations were performed to achieve antegrade recanalization of the ureteral lesion. Then, a ureteral stent was inserted to assure patency. RESULTS: Average stricture length was 1.21 (range 0.5-1.9 cm). Success of the aforementioned technique was possible in 18 ureters. Successful management in one session took place in 14 ureters. Average hospitalization time was 1.8 days (range 0-5 d). The follow-up period ranged between 12 and 18 months, with mean follow-up time of 12.9 months. Ureteral patency was evident at 1 week follow-up in six patients with obstructed ureters. In the remaining patients, balloon dilation of the stricture was repeated, and another stent was placed. Extravasation of contrast was observed in two patients with extravasating ureters in the same period. Nephrostomy tubes were removed after a mean indwelling period of 5.9 weeks (range 1-12 wks). Two patients treated by the described method died during their hospitalization in the intensive care unit because of sepsis from peritonitis that was related to colon injury and multiple concomitant injuries. Major complications were not observed in the remaining 22 patients during the follow-up period. CONCLUSION: The minimally invasive management of ureteral injuries is a safe and efficient method for both ureteral obstruction and/or laceration in a wide range of iatrogenic ureteral injuries.

Ureteral obstruction: is the full metallic double-pigtail stent the way to go?

BACKGROUND: The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo. OBJECTIVE: The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction. DESIGN, SETTING, AND PARTICIPANTS: In total, 50 patients with extrinsic malignant obstruction (n=25), benign ureteral obstruction (n=18), and previously obstructed mesh metal stents (n=7) were prospectively evaluated. INTERVENTION: All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities. MEASUREMENTS: We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation. RESULTS AND LIMITATIONS: The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2-12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents. CONCLUSIONS: The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study.

Ureteral metal stents: 10-year experience with malignant ureteral obstruction treatment.

PURPOSE: Ureteral patency in malignant ureteral obstruction cases is a therapeutic challenge. We report our long-term experience with palliative treatment for extrinsic malignant ureteral obstruction with percutaneous placement of metal mesh stents. MATERIALS AND METHODS: From January 1996 to December 2005, 90 patients with a mean age of 59 years (range 35 to 80) with ureteral obstruction due to extrinsic ureteral compression and/or encasement by primary or metastatic tumors, or retroperitoneal lymphadenopathy underwent implantation of self-expandable metal mesh stents. A total of 119 ureters were managed. Followup included urinalysis, blood biochemistry tests and transabdominal ultrasound or intravenous urography. RESULTS: The technical success rate of percutaneous antegrade insertion of ureteral self-expandable metal mesh stents was 100%. Renal biochemistry normalized and hydronephrosis gradually resolved 1 to 2 weeks after stent insertion. Median followup was 15 months (range 8 to 38). Hyperplastic reaction and/or encrustation, or tumor ingrowth developed in 45 stents. Secondary intervention, such as repeat balloon dilation and coaxial stenting, was done to improve patency. Migration was observed in 13 metal stents. The primary and secondary patency rates during followup were 51.2% and 62.1%, respectively. A double pigtail or external-internal stent was inserted in 45 cases in which secondary interventions did not ensure patency. CONCLUSIONS: Internal drainage of extrinsic malignant ureteral obstruction with metal mesh stents provides long-term decompression of the upper urinary tract in select cases. Certain problems limit the application of metal mesh stents in the ureter. Further studies are warranted to identify independent predictors of ureteral patency after the application of metal stents for malignant obstruction.

Thrombin promotes arteriogenesis and hemodynamic recovery in a rabbit hindlimb ischemia model.

BACKGROUND: Compared with angiogenesis, arteriogenesis is a distinct process based on the remodeling and maturation of pre-existing arterioles into large conductance arteries. Therapeutic angiogenesis has been proposed as a potential treatment for ischemic atherosclerotic diseases. Since a variety of angiogenic factors have been tested with inconsistent so far clinical results, the challenge remains in identifying the factor(s) that will stimulate functional neovascularization. Thrombin has been reported to play a pivotal role in the initiation of angiogenesis by regulating and organizing a network of angiogenic mediators. Also, it was recently demonstrated that thrombin is a potent anti-apoptotic factor for endothelial cells, providing evidence on a potential role of thrombin in vascular protection and maintenance of vessel integrity. Based on these observations, we hypothesized that thrombin may promote the development of mature functional blood vessels. METHODS: Seventy-four (n=74) rabbits underwent bilateral femoral artery surgical excision. On the 20th postsurgical day increasing doses of VEGF or bFGF or thrombin were injected in one ischemic limb per rabbit and an equal volume of normal saline to the contralateral control limbs. Quantification of newly developed collateral vessels (diameter >500 mum) was performed by transauricular intra-arterial subtraction angiography. Computerized quantitative analysis of collateral vessels in angiography images was based on the concept of multiscale structural tensor. Perfusion analysis of an in vivo dynamic computed tomography study was performed to investigate hemodynamic recovery of the distal ischemic limbs. Tissue perfusion analysis was performed with the semiquantitative slope methodology, which focuses on the first-pass arterial phase. RESULTS: A single administration of thrombin exhibited a dose-dependent increase of arteriogenic outcome. Thrombin at 5000 IU induced a 30.2 +/- 7.4% (P < 0.05) increase of total collateral area and length. Both VEGF and bFGF were without any significant effect at the concentrations used. Functional estimation of limb perfusion showed a statistically significant increase of blood flow recovery only for thrombin. The semiquantitative slope method perfusion score differed significantly in the 5000 IU thrombin treated limbs (5.7 +/- 0.3 vs 5.0 +/- 0.3 in control ischemic limbs; P < .05), and was not significantly inferior from the score of normal nonoperated limbs (6.5 +/- 0.3) suggesting a trend towards hemodynamic recovery of distal limb perfusion. CONCLUSIONS: In a rabbit hindlimb ischemia model, thrombin promoted the formation of large collateral vessels and improved the perfusion of distal ischemic tissue. These results provide new insights in understanding the involvement of thrombin in vascular formation and point to a novel role of thrombin in arteriogenesis.

Osteoid osteoma: diagnosis and treatment.

Treatment of small but painful osteoid osteomas was traditionally based on either prolonged medication or resection. In the era of rapidly evolving minimally invasive techniques, reluctance has been posed against surgical interventions mostly due to their relatively high rates of recurrence, complications, or persistent pain. Nonetheless, incomplete pain control and intolerance to anti-inflammatory drugs unfavorably affect prognosis. The objective of this article is to explore the nature and clinical presentation of osteoid osteomas, discuss their imaging and histological features, review available data regarding surgical and percutaneous methods for addressing these lesions and comment on their feasibility, safety, and efficacy.

Global vasomotor dysfunction and accelerated vascular aging in beta-thalassemia major.

BACKGROUND: Patients with beta-thalassemia major (beta-TM) demonstrate an increased incidence of vascular complications, which are thought to result from a procoagulant/proinflammatory environment. We investigated the arterial vasorelaxing capacity and sought for early carotid atherosclerosis and underlying pathophysiological correlates in these transfusion-dependent patients. METHODS AND RESULTS: The vasodilatory properties of the brachial artery and the carotid intima-media thickness (IMT) were examined with ultrasonography in 35 non-diabetic young adults with beta-TM (patient group) and 35 control subjects (control group). Among thalassemic patients, both endothelium-dependent (FMD) and -independent dilatation (FID) as well as their ratio was impaired, whereas IMT was increased (p<0.01). Patients on optimal, as compared with those on non-optimal chelation treatment had a non-significantly lower IMT. Vasodilatory capacity in the patient group was inversely correlated with IMT and independently associated either with the quality of chelation therapy (FMD) or serum ferritin levels (FID). Plasma concentrations of D-dimers, circulating markers of endothelial activation, inflammation and apoptosis were higher, while plasma cholesterol and fibrinogen levels were lower-than-normal in the patient group. Independent predictors of IMT among thalassemic patients were tumor necrosis factor-alpha levels and age. CONCLUSIONS: Young adults with beta-TM exhibit both a global impairment of arterial vasorelaxation and early carotid atherosclerosis. A procoagulant/proinflammatory state in these transfusion-dependent patients may overwhelm atheroprotective mechanisms, including an optimal chelation regimen, and promote vascular injury and atherogenesis.

Application of paclitaxel-eluting metal stents in renal artery of pig model.

BACKGROUND AND PURPOSE: Recent reports concerning coronary, carotid, and femoral vasculature have proposed the use of drug-eluting metal stents (MS) to improve clinical and angiographic outcomes. Based on these reports, we used paclitaxel-eluting MS within an animal renal artery lumen and compared the results with those using a bare-metal stent. MATERIALS AND METHODS: The experimental model in this study was the female pig renal artery. Ten pigs with weights ranging from 25 to 30 kg were used. Twenty stents were placed, two in each animal. The MS placement was randomly performed in either the right or left renal artery of each animal. In 10 arteries, a 3.5 x 18 mm R-stent (group A) was placed; in the remaining 10 arteries, a 3 x 32 mm paclitaxel-eluting coronary stent (T-stent, group B) was inserted. Patency was estimated with the use of digital subtraction angiography, CT angiography, and virtual endoscopy at 24 hours and 1 month poststent placement. RESULTS: The positioning of the MS was successful in all cases. The initial angiographic result was maintained 24 hours after the intervention. No stent migration was seen, except for one paclitaxel stent that was acutely occluded. The one-month patency rate, as demonstrated by angiography, CT angiography, and virtual endoscopy, was 70% (8 arteries) in group A and 90% (9 arteries) in group B. The thickness of the endothelium and of the muscular coat was statistically significantly less in group B compared with group A (P = 0.0352 and P = 0.0046, respectively). CONCLUSION: These preliminary experimental study results suggest that the paclitaxel-eluting MS is more efficient than the bare-metal stent when used within the pig renal artery. Further experimental and clinical studies are necessary to validate our preliminary encouraging results.

External beam irradiation and restenosis following femoral stenting: long-term results of a prospective randomized study.

PURPOSE: To assess the long-term outcome of external beam irradiation (EBI) for the prevention of restenosis due to neointimal hyperplasia, following percutaneous transluminal angioplasty (PTA) and stenting of the superficial femoral artery. METHODS: Sixty consecutive patients with peripheral arterial disease, who were treated with "bail-out" stent implantation in the superficial femoral artery due to suboptimal PTA, were included in this study. Patients were randomly allocated into two groups, receiving either external beam irradiation (6 MV photons, total dose 24 Gy in a hypofractionated schedule) plus antiplatelet therapy (EBI group) or antiplatelet therapy alone (control group). RESULTS: No procedure-related complications occurred, and all patients of the EBI group received the full dose of 24 Gy. During the long-term follow-up, an overall statistically significant difference was demonstrated in favor of the EBI group patients, regarding both the in-stent (log-rank test, p = 0.0072) and the in-segment binary restenosis (log-rank test, p = 0.0103). The primary patency rates were also significantly better in the EBI group at specific time-points, such as in the first (74.2% vs 46.5%, p = 0.019), second (62.5% vs 33.8%, p = 0.020), and third (54.6% vs 29.0%, p = 0.039) year, respectively. Moreover, the overall clinically driven reintervention rate was significantly lower among patients of the irradiated group (log-rank test, p = 0.038). CONCLUSION: Our long-term follow-up analysis revealed that EBI following femoral artery PTA and stenting significantly reduces restenosis and reintervention rates, while improving primary patency.

Application of paclitaxel-eluting metal mesh stents within the pig ureter: an experimental study.

OBJECTIVE: The purpose of the present study is to compare the standard bare metal stents (BMS) with the Paclitaxel-Drug Eluting Stent (DES) in the ureter of a pig model. MATERIALS AND METHODS: We report on an experimental study with ten female pigs weighing between 25 and 30 kg. The stents were randomly placed in either the right or left ureter in each of 10 study animals, for a total of 20 stented ureters. Ten ureters were stented with an R-Stent (Orbus Medical Technologies, Hoevelaken Netherlands), and ten with a Paclitaxel-Eluting Coronary Stent (Boston Scientific, Natick, MA, USA). Patency was measured by radiograph of the nephrostomy tract, intravenous urography and virtual endoscopy at 24 hours and 21 days after the initial procedure, respectively. RESULTS: Free flow of urine through the stents into the bladder was documented in all stented ureters 24 hours after stent insertion by radiograph of the nephrostomy tract. At the 21 day follow-up examination, 5 R-Stents were found to be completely occluded and two partially stenosed, whereas no occluded stent was detected in the Paclitaxel-DES group. Pathology examination of the stents at 21 days follow-up showed that the obstructed R-Stents generated severe inflammation with metaplasia of the urothelium. The Paclitaxel-Eluting MS generated a mild inflammatory response within the ureteral lumen at the site of the stent, without hindering ureteral patency. R-stents proved to develop more hyperplasia compared to the Paclitaxel-Eluting MS. CONCLUSIONS: Paclitaxel-DES, when compared with the standard R- Stent BMS, generated less inflammation and/or hyperplasia of the surrounding tissues, thus maintaining ureteral patency. Long-term animal trials are required to further validate our results.

Trends and future needs in clinical radiology: insights from an academic medical center.

OBJECTIVE: Advances in technology, expanding indications and defensive medical practice, in combination with population aging, have all contributed to a substantial increase in utilization of imaging and therapeutic radiology procedures in recent years. Moreover, the integration of education, innovation and research into high-volume workflow, although challenging, is a key requirement in teaching hospitals. Therefore, identifying forthcoming demand in the use of radiology services at a referral center might be of special interest and facilitate health policy planning in this context. METHODS: Data regarding conventional radiographic, ultrasonographic and computed tomography (CT) investigations, radiotherapy sessions, and interventional procedures were collected for a 5-year period (2000-2004). Based on these observations, we deployed appropriate models to forecast utilization rates in 2005-2009. RESULTS: Between 2000 and 2004, ultrasound examinations increased by 31.8%, mammography by 31.6%, CT scans by 17.4%, interventions by 14.5% and radiotherapy sessions by 13.9%, while conventional investigations decreased by 42.5%. We identified significant increasing trends for ultrasound, mammography, CT and interventions (all p<0.001 for linear component). Compared to current levels, the workload for these modalities is expected to rise in the next 5 years by 43%, 31%, 20% and 14%, respectively. Radiotherapy sessions demonstrate an unstable, non-significant increasing trend (p=0.189), while utilization of conventional radiography declines rapidly (p<0.001 for linear trend, 5-year prediction -51%). CONCLUSIONS: In forthcoming years, the demand for radiology services at referral centers will increase substantially. Advances in digital technology alone will not suffice to completely alleviate the need for additional resources and well-trained personnel.

Digital subtraction angiography and computer assisted image analysis for the evaluation of the antiangiogenetic effect of ionizing radiation on tumor angiogenesis.

PURPOSE: The aim of the present study was to evaluate and quantify the antiangiogenetic effect of ionizing radiation on tumor angiogenesis using digital subtraction angiography (DSA) in conjunction with computer assisted image analysis (CAIA). METHODS: Walker 256 carcinosarcoma was inoculated in both glutei of 12 Wistar rats. When the tumors reached a diameter of 1.5 cm, local irradiation of the right gluteus was performed. The left gluteus of each animal served as a control. After 24 hours of irradiation, angiography was performed, and images where digitized and subsequently processed. The effect of irradiation was observed both in big and small vessels (smaller or greater than 200 microm). RESULTS: Irradiated areas of both small and big vessels showed a statistically significant reduction in both total vessel area and length. Small vessels showed a greater trend toward suppression by irradiation (not statistically significant). CONCLUSION: Irradiation had a deleterious effect in both macro- and micro-blood supply of a tumor. The use of CAIA enhanced the efficacy of DSA and enabled the in vivo identification of the effect of irradiation on various caliber vessels as well as the ratios of total length and total area of small and big vessels.

Non-palpable breast carcinomas: correlation of mammographically detected malignant-appearing microcalcifications and epidermal growth factor receptor (EGFR) family expression.

Malignant-appearing microcalcifications (MAMCs) represent one of the earliest mammographic findings of non-palpable breast carcinomas (NPBCs). In the present study, we have evaluated the expression of all EGFR family members in NPBCs and its possible association with MAMCs. Three hundred and fifty patients with non-palpable suspicious breast lesions detected during screening mammography were studied. EGFR family proteins' expression was found to be present since the preclinical phase of breast carcinomas and was strongly correlated (except HER-3) with MAMCs. The co-expression pattern of EGFR family members combined with other molecular prognostic factors and the mammographic appearance might predict the natural history of NPBCs.

Virtual endoscopy of the urinary tract.

Technological breakthroughs have advanced the temporal and spatial resolutions of diagnostic imaging, and 3 dimensional (3-D) reconstruction techniques have been introduced into everyday clinical practice. Virtual endoscopy (VE) is a non-invasive technique that amplifies the perception of cross-sectional images in the 3-D space, providing precise spatial relationships of pathological regions and their surrounding structures. A variety of computer algorithms can be used to generate 3-D images, taking advantage of the information inherent in either spiral computed tomography or magnetic resonance imaging (MRI). VE images enable endoluminal navigation through hollow organs, thus simulating conventional endoscopy. Several clinical studies have validated the diagnostic utility of virtual cystoscopy, which has high sensitivity and specificity rates in the detection of bladder tumor. Published experience in the virtual exploration of the renal pelvis, ureter and urethra is encouraging but still scarce. VE is a safe, non-invasive method that could be applied in the long-term follow-up of patients with ureteropelvic junction obstruction, urinary bladder tumors and ureteral and/or urethral strictures. Its principal limitations are the inability to provide biopsy tissue specimens for histopathologic examination and the associated ionizing radiation hazards (unless MRI is used). However, in the case of endoluminal stenosis or obstruction, VE permits virtual endoluminal navigation both cephalad and caudal to the stenotic segment. To conclude, VE provides a less invasive method of evaluating the urinary tract, especially for clinicians who are less familiar with cross-sectional imaging than radiologists.

Ureteral metal stents: a tale or a tool?

There are four types of ureteral metal stents: self expandable, balloon expandable, covered, and thermoexpandable shape-memory. Insertion of metal stents requires expertise with transurethral and percutaneous techniques. The stricture is traversed with the aid of a guidewire via a percutaneous nephrostomy, and the stenotic segment is dilated using a high-pressure balloon catheter. The stent is then inserted over the guidewire, such that the upper end bypasses the obstruction by at least 3 to 4 cm, while the lower end extends intravesically for 0.5 to 1 cm from the ureteral orifice. If necessary, two or more stents are placed in sequence, overlapping by at least 2 to 3 cm. Metal stents were initially used for the relief of end-stage malignant disease, and their role in the treatment of benign ureteral strictures is still undefined. Patients often complain of abdominal discomfort and mild pain after stent insertion, which soon resolve spontaneously. Hematuria usually stops after a few days and does not necessitate any treatment. Mild urothelial hyperplasia in the stent lumen is common but usually regresses after 4 to 6 weeks. Many authors suggest the use of a double-pigtail catheter for the first 4 to 6 weeks to avoid narrowing of the ureteral lumen. The influence of stents on ureteral peristalsis is a major but poorly documented issue. Encrustation is a significant problem that needs to be addressed. The characteristics of both the patient and the stent influence its likelihood. Migration of coated metal stents was seen in 81% of patients at our center. Virtual endoscopy has recently been introduced as a tool for the follow-up of patients with stented ureters. Further design development is necessary to obtain the ideal ureteral metal stent. In a recent study in female pigs, paclitaxel-eluting metal stents engendered less inflammation and hyperplasia of the surrounding tissues.

Hemobilia secondary to hepatic artery pseudoaneurysm: an unusual complication of bile leakage in a patient with a history of a resected IIIb Klatskin tumor.

We report a case of a 74-year-old woman with a 16-year history of a double bilo-enteric anastomosis due to resected hilar cholangiocarcinoma (Type IIIb Klatskin tumor). The patient presented with cholangitis secondary to benign anastomotic stenosis which resulted in a large intrahepatic biloma. In order to restore the patency of the anastomosis and overcome cholangitis, several attempts took place, including endobiliary stenting, balloon-assisted biloplasty and transhepatic billiary drainage. Anastomotic patency was achieved, complicated, however, by persistent upper gastro-intestinal bleeding, presented as hemobilia. A biloma-induced pseudoaneurysm of the left hepatic artery was diagnosed. This had ruptured into the biliary tract, and presented the actual cause of the hemobilia. Selective embolism of the pseudoaneurysm resulted in control of the hemorrhage, and was successfully combined with transhepatic dilatation of the anastomosis and percutaneous drainage of the biloma. The patient was ultimately cured and seems to be in excellent condition, 5 mo after treatment.