MRI-guided percutaneous transhepatic cholangiodrainage: feasibility study in a porcine model.

BACKGROUND AND STUDY AIMS: MRI-guided procedures combine high-quality imaging with lack of radiation. Percutaneous transhepatic cholangiodrainage under real-time MRI guidance (MRI-PTCD) seems promising, allowing targeted puncture and avoiding multiple blind passes and use of contrast, which are associated with standard PTCD's heaviest complications. PATIENTS AND METHODS: Aim of this study was to investigate the feasibility of MRI-PTCD in three outbred piglets. Obstructive cholestasis was induced by common bile duct ligation. Two days later, MRI-PTCD was performed (open MRI, 1.0 Tesla) with prototype MRI-compatible accessories. Visualization was achieved with a balanced steady-state free precession real-time sequence (bSSFP: 0.75 frames/s, TR/TE [ms]: 7.2/3.6; flip angle: 45°; 200 × 200 matrix size; resolution: 1.3 × 1.3 mm(2), slice thickness: 7 mm). Cannulation of the bile ducts was followed by placement of Yamakawa drainages. RESULTS: Twelve punctures were performed (four per animal, 10/12 successful); in 2/10 the bile ducts could not be cannulated. Animal survival was 100% and no significant complications occurred. CONCLUSIONS: Initial data show that MRI-PTCD can be successfully performed. This may lead to establishment of a new optimized PTCD technique compared to the standard approach under fluoroscopy.

LFA-1 expression in a series of colorectal adenocarcinomas.

INTRODUCTION: LFA-1 is an adhesion molecule which belongs to the ß2-integrin family. Overexpression of LFA-1 in hepatic natural killer cells has been associated with increased apoptosis of neoplastic cells in colorectal cancer (CRC); moreover, studies in CRC have linked LFA-1 overexpression in neoplastic cells with vascular intrusion through adhesion to endothelial cells, thus implying a possible role in creation of metastases. AIMS AND METHODS: We studied the expression of LFA-1 in a series of 82 patients with CRC. A standard three-step immunohistochemical analysis was performed on formalin-fixed, paraffin-embedded tissue sections. An IgG2a anti-CD11a monoclonal antibody was used. Cases were characterized according to clinicopathological variables including sex, age, tumor localization, size, grade, Dukes stage, wall invasion, and presence of metastatic lymph nodes (mLNs) or distal metastases. RESULTS: LFA-1 was expressed at the primary tumor site in 51 cases and 6/33 cases with metastatic lymphnodes. In Dukes D cases (n = 4), only one case was LFA-1(+). LFA-1 expression at the primary tumor site was associated with the absence of metastatic disease and with Dukes B stage. However, in those cases with LFA-1 expression in cancer cells in mLNs, this was associated with its expression at the primary tumor site. CONCLUSION: The positive association of LFA-1 expression in mLNs when the primary tumor site is also LFA-1(+) could imply an adaptation advantage of this specific cellular clone to its micro-environment, predisposing it to creation of mLNs, pointing to a role for LFA-1 in creation of mLNs in CRC.

Percutaneous transhepatic cholangiodrainage under real-time MRI guidance: initial experience in an animal model.

AIMS: To assess percutaneous transhepatic cholangiodrainage (PTCD) under real-time MRI-guidance and compare it to procedures performed under fluoroscopy. METHODS: We developed an in vitro model for MRI-guided and conventional PTCD, using an animal organ set including liver and bile ducts placed in an MRI-compatible box and tested it in a 1.0-Tesla open MRI-scanner. Prototype 18G needles and guide wires, standard guide wires, dilatation bougies, and drainages were used (MRI-compatible). MRI-visualization was by means of a bFFE real-time sequence using a surface coil (Flex-L). Outcome measurements were success rates and time needed for bile duct puncture using real-time MRI-guidance versus conventional radiologic methods in the model. Cannulation and drainage placement were also analysed. RESULTS: Fifty MRI-guided experiments were performed, leading to rapid (mean: 43s, range: 15-72s) and successful puncture and cannulation in 96% of procedures. Median drainage placement time was 321.5s (range: 241-411s). In 35 control experiments under fluoroscopy, puncture success was 69%, whereas times were significantly longer (mean 273s, range 45-631s). CONCLUSIONS: Initial in vitro experience shows that PTCD can be successfully and rapidly performed under real-time MRI-guidance and demonstrates improved performance compared to the conventional radiologic approach.

Tissue detection of natural killer cells in colorectal adenocarcinoma.

BACKGROUND: Natural killer (NK) cells represent a first line of defence against a developing cancer; however, their exact role in colorectal cancer remains undetermined. The aim of the present study was to evaluate the expression of CD16 and CD57 [immunohistochemical markers of natural NK cells] in colorectal adenocarcinoma. METHODS: Presence of NK cells was investigated in 82 colorectal adenocarcinomas. Immunohistochemical analysis was performed, using 2 monoclonal antibodies (anti-Fc Gamma Receptor II, CD16 and an equivalent to Leu-7, specific for CD-57). The number of immunopositive cells (%) was evaluated by image analysis. The cases were characterized according to: patient gender and age, tumor location, size, grade, bowel wall invasion, lymph node metastases and Dukes' stage. RESULTS: NK cells were detected in 79/82 cases at the primary tumor site, 27/33 metastatic lymph nodes and 3/4 hepatic metastases; they were detected in levels similar to those reported in the literature, but their presence was not correlated to the clinical or pathological characteristics of the series, except for a negative association with the patients' age (p = 0.031). CONCLUSIONS: Our data do not support an association of NK cell tissue presence with clinical or pathological variables of colorectal adenocarcinoma, except for a negative association with the patients' age; this might possibly be attributed to decreased adhesion molecule expression in older ages.