Maximal Diameter (maximal + diameter)

Distribution by Scientific Domains


Selected Abstracts


Treatment response to transcatheter arterial embolization and chemoembolization in primary and metastatic tumors of the liver

HPB, Issue 6 2008
Avo Artinyan
Abstract Introduction. Transcatheter arterial embolization (TAE) and chemoembolization (TACE) are increasingly used to treat unresectable primary and metastatic liver tumors. The purpose of this study was to determine the objective response to TAE and TACE in unresectable hepatic malignancies and to identify clinicopathologic predictors of response. Materials and methods. Seventy-nine consecutive patients who underwent 119 TAE/TACE procedures between 1998 and 2006 were reviewed. The change in maximal diameter of 121 evaluable lesions in 56 patients was calculated from pre and post-procedure imaging. Response rates were determined using Response Evaluation Criteria in Solid Tumors (RECIST) guidelines. The Kaplan-Meier method was used to compare survival in responders vs. non-responders and in primary vs. metastatic histologies. Results. TAE and TACE resulted in a mean decrease in lesion size of 10.3%±1.9% (p<0.001). TACE (vs. TAE) and carcinoid tumors were associated with a greater response (p<0.05). Lesion response was not predicted by pre-treatment size, vascularity, or histology. The RECIST partial response (PR) rate was 12.3% and all partial responders were in the TACE group. Neuroendocrine tumors, and specifically carcinoid lesions, had a significantly greater PR rate (p<0.05). Overall survival, however, was not associated with histology or radiologic response. Discussion. TAE and TACE produce a significant objective treatment response by RECIST criteria. Response is greatest in neuroendocrine tumors and is independent of vascularity and lesion size. TACE appears to be superior to TAE. Although an association of response with improved survival was not demonstrated, large cohort studies are necessary to further define this relationship. [source]


Natural course of hepatic focal nodular hyperplasia: A long-term follow-up study with sonography

JOURNAL OF CLINICAL ULTRASOUND, Issue 3 2009
Yuan-Hung Kuo MD
Abstract Purpose. We aimed to investigate the natural course of hepatic focal nodular hyperplasia (FNH) in a long-term follow-up study with sonography. Method. This study comprised 30 patients (24 women and 6 men) with 34 FNHs. Diagnosis of FNH was made using color Doppler sonography, contrast-enhanced CT, or MRI in combination with needle biopsy. Patients were followed every 3 to 6 months with sonography. Regression or progression of tumor was defined as a change of over 30% in maximal diameter. Disappearance was defined as no vizualization of the tumor on at least 3 follow-up sonographic examinations. Results. Thirty-four FNHs were followed over a mean period of 42 months (range, 7,95 months). Twenty-four lesions (70.6%) were stable in size, 1 (2.9%) progressed, and 9 (26.5%) regressed. Of those that regressed, 6 (17.6%) disappeared over a mean period of 59 ± 30 months (range, 20,95 months). Older age (OR 1.26, 95% CI 1.02,1.56; p < 0.05) and longer follow-up time (OR 1.11, 95% CI 1.01,1.21; p < 0.05) were the independent factors associated with complete regression of FNH. Conclusion. Most FNHs were stable or regressed/disappeared after a long follow-up period. Based on the benign course, conservative treatment for asymptomatic FNH should be advocated. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound 2009. [source]


Is aperistalsis with complete lower esophageal sphincter relaxation an early stage of classic achalasia?

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 4 2007
Jeong Hwan Kim
Abstract Background:, Aperistalsis with complete lower esophageal sphinter (LES) relaxation, characterized by the complete relaxation of the LES and aperistalsis of the esophageal body on manometry, has been considered by some authors to be an early manifestation of classic achalasia, which is defined as incomplete relaxation of the LES and aperistalsis of the esophageal body. The aim of the present study was to compare the clinical features of patients with aperistalsis with complete LES relaxation, with those of patients with classic achalasia. Methods:, Eighteen patients with aperistalsis with complete LES relaxation and 53 patients with classic achalasia were analyzed with regard to clinical history, the maximal diameter of the esophageal body on barium esophagogram, LES resting pressure and the duration of LES relaxation on manometric recordings, and the selected treatment and its efficacy. Results:, The aperistalsis with complete LES relaxation group had distinctly different features compared to those of the classic achalasia group including older age, more frequent association with non-cardiac chest pain, less frequent association with dysphagia and weight loss, lower LES resting pressures, and longer duration of LES relaxation. However, the two groups were similar in terms of maximal diameter of the esophageal body, and efficacy associated with pneumatic dilation. Conclusions:, Aperistalsis with complete LES relaxation on manometry is not necessarily an early manifestation of classic achalasia. However, this condition does not preclude a diagnosis of achalasia or a good response to achalasia therapy. [source]


Expression of matrix metalloproteinase-9 in predicting prognosis of hepatocellular carcinoma after liver transplantation

LIVER TRANSPLANTATION, Issue 5 2010
Deniz Nart
Matrix metalloproteinases (MMPs) are known to play an important role in cell migration during cancer invasion by degrading extracellular matrix proteins. This study aimed to determine the role of MMP-9 in hepatocellular carcinoma (HCC) carcinogenesis. Eighty-nine cases who underwent liver transplantation for HCC in cirrhotic liver were selected for this study. The tumor characteristics such as nodule number, maximal diameter, portal vein invasion, and the preoperative alpha-fetoprotein levels were reviewed. The intensity of immunostaining and the percentage of immunoreactive cells with MMP-9 were evaluated. All patients were evaluated for HCC recurrence and/or death, and cause of death was noted. There was a lower survival and more recurrence risk among participants with 4 or more nodules exceeding 3 cm in diameter, with poorly differentiated tumor, and with large-vessel involvement. Eleven patients developed recurrent HCC (12.4%). Twelve patients died as a result of HCC (13.5%). Among 89 HCCs, the incidences of a weak (+) and moderate (++) expression of MMP-9 in carcinoma cells were 30.3% (23/89) and 43.8% (39/89), respectively. Increased expression and intensity of MMP-9 were found to be inversely associated with poor tumor differentiation (P = 0.016, P = 0.009, respectively). A significant correlation between expression and intensity of MMP-9 and large vascular invasion (P = 0.01, and P = 0.03) was also observed. As far as prognosis is concerned, increased immunoreactivity and intensity of MMP-9 were found to exert an unfavorable impact on overall survival rates (P < 0.01, P = 0.01, respectively) and recurrences (P = 0.001, P = 0.02). Multivariate analyses revealed that MMP-9 staining percentage (P = 0.007) and portal vein invasion (P = 0.002) were independent predictors of survival, whereas the only independent predictor of recurrences was portal vein invasion (P = 0.007). In this study, our results indicate a positive association between MMP-9 expression and histopathologic parameters that indicate poor prognosis. We conclude that together, MMP-9 staining percentage and portal vein invasion in HCC may aid to predict poor outcome. Nevertheless MMP-9 staining percentage is expected to be a potential predictive marker on survival and needs to be studied more in detail. Liver Transpl 16:621-630, 2010. © 2010 AASLD. [source]


A Novel Route to Multiphase Polymer Systems Containing Nano-Droplets: Radical Polymerization of Vinylic Monomers in Gelled Water-in-Oil Miniemulsions

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005
Christian Holtze
Abstract Summary: A new strategy for the synthesis of composite polymers with larger volume fraction of aqueous inclusions less than 1 µm in diameter is presented. A water-in-oil miniemulsion of aqueous droplets in a continuous, cross-linkable monomer phase is prepared. The addition of an organo-gelator allows the immobilization of the droplets in a solid gel, thus avoiding the usual demixing upon polymerization of the continuous phase. This pregelled system is then converted into a composite polymer by photoinitiated free radical polymerization. Such coatings may be used for an improved climate control of buildings or as a deposit for the controlled release of actives from polar nano-droplets. SEM image of a cross-linked composite polymer showing controlled droplet inclusions with a maximal diameter of 500 nm. [source]


Ischemia,Reperfusion Impairs Ascending Vasodilation in Feed Arteries of Hamster Skeletal Muscle

MICROCIRCULATION, Issue 7 2005
MIRIAM C. J. DE WITH
ABSTRACT Objective: Vasodilation originating within the microcirculation ascends into proximal feed arteries during muscle contraction to attain peak levels of muscle blood flow. Ascending vasodilation (AVD) requires an intact endothelium, as does conducted vasodilation in response to acetylcholine (ACh). Whereas ischemia,reperfusion (I-R) can affect endothelial cell function, the effect of I-R on AVD is unknown. The authors tested the hypothesis that I-R (1h,1h) would impair AVD. Methods: Using the retractor muscle of anesthetized hamsters, contractions were evoked using field stimulation (200 ms at 40 Hz every 2 s for 1 min) and ACh was delivered using microiontophoresis (1 ,m tip, 500,4000 ms pulse at 800 nA). Feed artery responses were monitored 500,1500 ,m upstream. Results: Neither resting (51 ± 4 ,m) nor maximal diameter (81 ± 5 ,m; 10 ,m sodium nitroprusside) following I-R (n = 8) were different from time-matched controls (n = 10). With peak active tension of 23 ± 4 mN · mm,2, control AVD was 26 ± 2 ,m. Following I-R, active tension fell by 48% (p < .05) and AVD by 57% (p < .05). Stimulation at 70 Hz restored active tension but AVD remained depressed by nearly half (p < .05), as did local and conducted responses to ACh. Nevertheless, control responses to 500 ms ACh were restored by increasing stimulus duration to 4000 ms. Conclusions: Ischemia,reperfusion impairs the initiation of feed artery dilation with muscle contraction and with ACh while conduction along the vessel wall is preserved. Respective components of endothelial cell signaling events may differ in their susceptibility to I-R. [source]


Treatment of internal iliac artery aneurysms: single-centre experience

ANZ JOURNAL OF SURGERY, Issue 4 2009
Nikolaos Tsilimparis
Abstract Background:, The aim of the present study was to analyse the short-term results of treatment of internal iliac artery aneurysms (IIAA). Methods:, In a prospective single-centre cohort study all patients with IIAA (symptomatic or maximal diameter ,30 mm) were evaluated for endovascular repair, which included coil embolization of the run-off vessels and coverage of the orifice of the IIAA with a stent graft. Open repair was performed with aneurysm excision or aneurysmorrhaphy. Outcome criteria were technical and clinical success and complications of treatment. Results:, In a period of 40 months 11 patients underwent operation for 12 IIAA. Nine aneurysms were repaired endovascularly and three with open repair. Coil embolization was routinely performed in all cases. At a median follow up of 18 months, technical and clinical success was 100%. Major complications included two early limb thromboses, a contrast-agent-induced nephropathy, and an intraoperative ureteric injury. Conclusion:, Despite the limited number of patients, the present series, with good short-term results, further supports the trend towards endovascular repair of suitable IIAA. [source]


Diameter of the Cochlear Nerve in Endolymphatic Hydrops: Implications for the Etiology of Hearing Loss in Ménière's Disease,

THE LARYNGOSCOPE, Issue 9 2005
Cliff A. Megerian MD
Abstract Objective/Hypothesis: Endolymphatic hydrops (ELH) is an important histopathological hallmark of Ménière's disease. Experimental data from human temporal bones as well as animal models of the disorder have generally failed to determine the mechanism by which ELH or related pathology causes hearing loss. Hair cell and spiral ganglion cell counts in both human and animal case studies have not, for the most part, shown severe enough deterioration to explain associated severe sensorineural hearing loss. However a limited number of detailed ultrastructural studies have demonstrated significant reductions in dendritic innervation densities, raising the possibility that neurotoxicity plays an important role in the pathology of Ménière's disease (MD) as well as experimental endolymphatic hydrops (ELH). This study tests the hypothesis that neurotoxicity is an important primary mediator of injury to the hydropic ear and is reflected in measurable deterioration of the cochlear nerve in the animal model of ELH. This study also explores the previously presented hypothesis that cochlear injury in ELH is mediated through the actions of nitric oxide (NO) by evaluating whether hearing loss or various measures of cochlear damage can be ameliorated by administration of an agent that limits excess production of NO. Study Design: Part one of the project involves the surgical induction of endolymphatic hydrops and correlation of long term hearing loss with histological parameters of ELH severity as well as cochlear nerve and eighth cranial nerve diameter measurements. In part two, aminoguanidine is administered orally to a separate set of hydropic animals in an attempt to limit cochlear injury presumably mediated by NO. Methods: Guinea pigs are subjected to surgical induction of unilateral endolymphatic hydrops after establishing baseline ABR thresholds at 2, 4, 8, 16, and 32 kHz. Threshold shifts are established prior to sacrifice at 4 to 6 months and temporal bones processed for light microscopy. Measurements of cochlear nerve and eighth cranial nerve maximal diameters as well as average maximal diameters are carried out and correlated to hearing loss and a semi-quantitative measure of hydrops severity. The identical experiments are carried out in animals treated with aminoguanidine, an inhibitor of inducible nitric oxide synthase. Results: The mean maximal diameter (n = 14) of the hydropic cochlear nerve was significantly reduced (432.14 ± 43.18 vs. 479.28 ± 49.22 microns, P = .0025) as compared to the control nerve. This was also seen in measures of the eighth cranial nerve (855.71 ± 108.82 vs. 929 ± 81.53 microns, P = 0.0003). Correlation studies failed to show correlation between hydrops severity and a cochlear nerve deterioration index (r = -0.0614, P = .8348). Similarly, hearing loss severity failed to correlate with cochlear nerve deterioration (r = 0.1300, P = .6577). There was a significant correlation between hearing loss and hydrops severity (r = 0.6148, P = .0193). Aminoguanidine treated animals (n = 5) also sustained nerve deterioration to the same degree as non-treated animals and there appeared to be no protective effect (at the dosage administered) against ELH related hearing loss, hydrops formation, or nerve deterioration. Conclusion: ELH results in significant deterioration of cochlear nerve and eighth cranial nerve maximal diameters in the guinea pig model. These findings are in accord with previous studies which detected ultrastructural evidence of dendritic damage and indicate that neural injury is of sufficient severity to result in light microscopic evidence of cochlear nerve and eighth cranial nerve deterioration. These data support the concept that the principle pathological insult in ELH is a form of neurotoxicity, especially in light of previous studies which indicate relative preservation of hair cells at similar points in time. The lack of correlation between the severity of hydrops and nerve deterioration suggests that nerve deterioration is independent of hydrops severity. [source]