Effectiveness of repeat angiographic assessment in patients designated for radioembolization using yttrium-90 microspheres with initial extrahepatic accumulation of technitium-99m macroaggregated albumin: a single center's experience.

PURPOSE: To evaluate the efficacy of a workflow consisting of repeat assessment in patients planned for yttrium-90 ((90)Y) radioembolization in case of nontarget visceral technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) accumulation despite initial prophylactic coil embolization of nonhepatic arteries. MATERIALS AND METHODS: In 341 patients with primary and secondary liver cancer, pretreatment hepatic angiograms, as well as single-photon emission computed tomography coregistered with magnetic resonance imaging scans, were obtained. Extrahepatic tracer deposition was identified in 33 patients (9.7%) necessitating repeat assessment. Images were reviewed to correlate the site of MAA accumulation with causative gastrointestinal vessels, and repeat angiograms served as reference standard. RESULTS: At repeat angiography, the source of extrahepatic flow was identified and eliminated in 31 of 33 patients (93.9%). In 20 patients (60.6%), successful embolization of nontarget vessels was achieved, in 13 patients (39.4%), MAA was administered more distally. Afterward, extrahepatic MAA deposition was eliminated in 30 patients (90.9%). CONCLUSION: The algorithm of repeat assessment in case of extrahepatic MAA accumulation has proven highly effective to eliminate extrahepatic shunting, thus decreasing the risk of postradioembolization complications due to inadvertent visceral microsphere deposition.

Prevention of intraprocedural puncture site bleeding during arterial port implantation by use of a suture-mediated arterial closure system: a prospective randomized trial.

PURPOSE: To investigate a modified technique for arterial port placement that uses a suture-mediated closure system with the aim to reduce delays caused by intraprocedural oozing around the catheter. MATERIALS AND METHODS: Forty consecutive patients (age, 63.9 y ± 11.8) stratified for regional arterial infusion chemotherapy were prospectively randomized to undergo conventional or modified port implantation. Time for device placement, total procedure time, number of catheters, size of largest and final catheters placed, duration of bleeding from puncture site, procedural delays, and time until hemostasis was achieved were recorded. RESULTS: Time for device placement was 3.7 minutes ± 1.1, with no complications encountered. Total procedure times were 133.0 minutes ± 62.8 for conventional port implantation and 100.0 minutes ± 49.5 for modified implantation (P = .13). No differences were found in the number of catheters or size of largest or final catheter used. Duration of groin bleeding necessitating manual compression was 21.8 minutes ± 24.4 for conventional port implantation, resulting in a mean procedural delay of 6.2 minutes ± 7.0. Hemostasis was achieved after a mean of 17.1 minutes ± 20.9. Groin hematoma was observed in three patients. In contrast, with the modified technique, mean duration of oozing and intraprocedural delays were only 0.2 minutes ± 0.6 and 0.1 minutes ± 0.5, respectively (both P < .0001 vs conventional technique). Hemostasis was achieved within 3.2 minutes ± 4.1 (P < .0001), with no cases of hematoma found. CONCLUSIONS: Use of a suture-mediated closure system facilitated arterial port implantation by effective prevention of groin bleeding while allowing the use of a sheath.

Value of preoperative superselective embolization of the isthmus in a patient with upper urinary tract urothelial carcinoma and horseshoe kidney.

Standard treatment for upper urinary tract urothelial carcinoma (UUTUC) implies the radical removal of all urothelium-lined tissue, which requires nephroureterectomy with bladder cuff removal. We report on a patient with a rare coincidence of UUTUC and horseshoe kidney in whom a preoperative angiography helped to identify and subsequently embolize an abberant isthmic feeding artery, which was located in between both collecting systems. Ischemic discoloration of the isthmus area facilitated resection and no major blood loss occurred. Preoperative superselective embolization of the isthmus as the renal split area can be an effective tool to facilitate nephroureterectomy in the case of a horseshoe kidney.

Identification of a novel isoform predominantly expressed in gastric tissue and a triple-base pair polymorphism of the cathepsin W gene.

In order to investigate the prevalence of potential polymorphisms of the cathepsin W gene, the complete cDNA of 50 dyspeptic patients was analyzed. From those 37 (74%) revealed the wildtype sequence, 6 samples (12%) contained independent single base pair changes including 4 silent and 2 with amino acid changes. Furthermore, a triple-base pair polymorphism was found in 7 samples (14%, 4x heterozygous, 3x homozygous) leading to the following changes: F(217)S, H(248)Y, and I(250)T. Furthermore, a novel alternative splice variant concerning intron 10 was identified in 6 samples (12%). Notably, this novel isoform was only found in samples of gastric mucosa lymphocytes, whereas peripheral NK cells expressed cathepsin W wildtype only. Taken together, this study demonstrated for the fist time that a genetic variant and a novel isoform of cathepsin W are present in about 14% and 12%, respectively, within the Caucasian population.

Functional involvement of cathepsin W in the cytotoxic activity of NK-92 cells.

Human cathepsin W (lymphopain) is a papain-like cysteine protease of unknown function that is specifically expressed in natural killer (NK) cells and to a lesser extent in cytotoxic T cells (CTL). In order to analyze the functional importance of cathepsin W for the cytotoxic process, we investigated NK-92 cells that have an NK cell-like phenotype and express cathepsin W. NK-92 cells possess strong cytotoxic activity against Jurkat and K562 cells. The cytotoxic activity of NK-92 cells against K562 was decreased in the presence of antisense phosphorothioate oligonucleotides against the cathepsin W-cDNA. Western blot analysis showed that the impaired cytotoxic activity of NK-92 cells was accompanied by reduced amounts of cathepsin W in the antisense-treated cells. In addition, co-cultivation experiments between NK-92 and K562 cells revealed a time-dependent decrease of cathepsin W by Western blot and immunofluorescence analysis during the cytotoxic attack, whereas CD56 expression of NK-92 cells was not affected. During cytotoxic attack, cathepsin W was neither targeted to K562 cells or other subcellular compartments, as shown by immunofluorescence analysis. The decrease of cathepsin W protein was associated with stable cathepsin W transcript levels. Control experiments using HT-29 cells, which are resistant against NK-92-mediated cytotoxicity, showed no change of cathepsin W expression, implying that the decrease of cathepsin W in the NK-92/K562 assay is linked to the cytotoxic process. Although the exact function of cathepsin W with respect to its enzymatic activity and its site of action still needs to be elucidated, our data demonstrate for the first time that cathepsin W is important for cellular cytotoxicity mediated by NK cells.