Thermal tumor ablation therapy for colorectal cancer hepatic metastasis.

Surgical resection for colorectal hepatic metastases (CRHM) is the preferred treatment for suitable candidates, and the only potentially curative modality. However, due to various limitations, the majority of patients with CRHM are not candidates for liver resection. In recent years, there has been an increasing interest in the role of thermal tumor ablation (TTA) as a component of combined resection-ablation strategies, staged hepatic resections, or as standalone adjunct treatment for patients with CRHM. Thus, ablative approaches have expanded the group of patients with CRHM that may benefit from liver-directed treatment strategies.

Development of hepatic pseudotumors for image-guided interventional and surgical research in a large animal model.

PURPOSE: Real-time image guidance and navigation have become increasingly important in an era of minimally invasive interventional and surgical procedures in the liver. To develop, test, and implement tools for real-time image guidance, the authors sought to create an in vivo tumor mimic with realistic imaging and treatment capabilities. MATERIALS AND METHODS: Hepatic pseudotumors were created by injecting 1-2 mL of alginate (a hydrocolloid) directly into the liver parenchyma in eight live pigs and two dog cadavers. Tumors were imaged by B-mode ultrasound (US), US elasticity imaging, multi-detector row computed tomography (CT), CT fluoroscopy, and magnetic resonance (MR) imaging to assess imaging capabilities. Procedures performed with the alginate pseudotumors included radiofrequency (RF) ablation and robotic needle guidance. RESULTS: Twenty-four hepatic pseudotumors were created, ranging in size from 10 mm to 28 mm at an average depth of 6 mm. Average time of preparation and insertion was 3 minutes. All tumors were palpable under the surface of the liver and were easily visible on B-mode US, US elasticity imaging, CT, and MR imaging. Tumors were successfully "treated" with RF ablation, and gross examination of the liver showed good encompassment of the tumor by the zone of thermal coagulation. In addition, the pseudotumors allowed for easy introduction of various types of needles, including RF ablation probes and experimental steerable needles. CONCLUSIONS: Alginate pseudotumors can easily be imaged and allow for different procedures to be performed. This model can be used for various research purposes.

Intra-abdominal healing: gastrointestinal tract and adhesions.

The abdominal cavity represents one of the most active areas of surgical activity. Surgical procedures involving the gastrointestinal (GI) tract are among the most common procedures performed today. Healing of the GI tract after removal of a segment of bowel and healing of the peritoneal surfaces with subsequent adhesion formation remain vexing clinical problems. Interventions to modify both the responses are myriad, yet a full understanding of the pathophysiology of these responses remains elusive. Different aspects of GI and peritoneal healing, with associated factors, are discussed in this article.

Factors determining the sensitivity of intraoperative ultrasonography in detecting colorectal liver metastases in the modern era.

BACKGROUND: With improved preoperative cross-sectional imaging, the added clinical value of intraoperative ultrasonography (IOUS) in the detection of colorectal liver metastases (CRLM) is unclear. Specifically, the ability of IOUS to detect additional liver metastases during surgery and its relationship between clinical and lesion specific ultrasonographic characteristics remains ill-defined. The purpose of the current study was to determine the association of clinical parameters and tumor echogenicity with the ability of IOUS to detect occult CRLM. MATERIALS AND METHODS: A total of 213 patients undergoing surgical exploration and IOUS for CRLM between 1998 and 2009 were included in the study. All patients underwent preoperative multidetector computed tomography (CT) imaging and lesion detection was compared with those identified by IOUS. In addition, early (<6 months) intrahepatic recurrence was used as a surrogate for residual disease (e.g., metastases that were undetected on initial IOUS). The influence of various characteristics on the rate in which additional metastases were detected and the rate of early intrahepatic recurrence was examined. RESULTS: Overall, IOUS detected additional liver metastases in 10% of patients (n = 22). Detection of additional metastases was significantly higher in patients with multiple (≥4) tumors (P < 0.001) and hypoechoic tumors (P = 0.007). Of 153 patients undergoing resection only, 17 (11%) had an early intrahepatic recurrence. This was more common in patients with isoechoic metastases during IOUS (P = 0.03). CONCLUSIONS: Even with the use of modern cross-sectional preoperative imaging, IOUS detects additional liver metastases in 10% of patients. In addition, the sensitivity of IOUS for detecting occult CRLM is highly dependent on the number and echogenicity of detected tumors.

Infected primary retroperitoneal teratoma presenting as a subhepatic abscess in a postpartum woman.

It is highly unusual for a 20-cm retroperitoneal teratoma to present as a subhepatic abscess with septic shock in a postpartum woman. We present a case of a multilocular cystic teratoma densely adherent to adjacent viscera and vessels. Because of the complexity of the case and the clinical condition of the patient, a 2-stage operation was employed for this special case. An initial emergency drainage effectively relieved symptoms of acute infection and facilitated the 2nd-stage resection of the tumor.

Significance of controlling chronic proliferative cholangitis in the treatment of hepatolithiasis.

BACKGROUND: Recently, high stone recurrence and biliary restenosis rates in hepatolithiasis patients have been confirmed to be closely related to chronic proliferative cholangitis (CPC). However, the effective management of CPC has not yet been established. METHODS AND RESULTS: A vicious cycle exists between the presence of intrahepatic calculi and CPC: both the stone itself and secondary biliary infection can stimulate persistent hyperplasia in the biliary duct wall, leading to the occurrence of CPC and biliary stricture. The recurrent attacks of CPC will, in turn, facilitate new stone formation via mucoglycoprotein production, or induced biliary stricture and cholestasis. Thus, even when the stone is completely removed and the biliary tract stenosis is corrected, residual CPC will persist and progress, with an underlying risk for postoperative stone recurrence and biliary tract restenosis. Therefore, the perfect hepatolithiasis treatment would target stone removal and correction of the biliary tract stricture, as well as control of postoperative residual CPC. In fact, CPC, the management of which has been traditionally ignored, is the key to breaking this vicious cycle. CONCLUSIONS: Overall, the subsequent treatment of residual CPC after operation or choledochoscopic lithotomy would be helpful to decrease postoperative stone recurrence and the rate of biliary restenosis. Adding such treatment would reduce the incidence of surgical reintervention and choledochoscopic lithotomy, and it would also improve the postoperative hepatolithiasis outlook.

Apparent behavioral benefits of tau overexpression in P301L tau transgenic mice.

Transgenic mice expressing human tau containing the P301L tau mutation (JNPL3; tau mice) develop motor neuron loss, paralysis and death between 7 and 12 months. Surprisingly, at 5 and 7 months of age, tau transgenic mice were superior to other genotypes in the rotarod task, and had near perfect scores on the balance beam and coat hanger tests. One tau transgenic mouse was performing at a superior level in the rotarod one day prior to developing paralysis. Cognitive function was also normal in the tau mice evaluated in the radial arm water maze and the Y-maze tasks. We also crossed the tau transgenic mice with Tg2576 amyloid-beta protein precursor (AbetaPP) transgenic mice. Although AbetaPP mice were deficient in the radial arm maze task, AbetaPP + tau mice were not impaired, implying a benefit of the tau transgene. Some mice were homozygous for the retinal degeneration mutation (rd/rd) and excluded from the genotype analysis. Only the water maze task discriminated the rd/rd mice from nontransgenic mice. In conclusion, it seems that the modest tau overexpression or the presence of mutant tau in the JNPL3 tau mice may provide some benefit with respect to motor and cognitive performance before the onset of paralysis.

Detection of amyloid plaques in mouse models of Alzheimer's disease by magnetic resonance imaging.

We performed three-dimensional, high-resolution magnetic resonance imaging (MRI) of fixed mouse brains to determine whether MRI can detect amyloid plaques in transgenic mouse models of Alzheimer's disease. Plaque-like structures in the cortex and hippocampus could be clearly identified in T2-weighted images with an image resolution of 46 microm x 72 microm x 72 microm. The locations of plaques were confirmed in coregistration studies comparing MR images with Congo red-stained histological results. This technique is quantitative, less labor-intensive compared to histology, and is free from artifacts related to sectioning process (deformation and missing tissues). It enabled us to study the distribution of plaques in the entire brain in 3D. The results of this study suggest that this method may be useful for assessing treatment efficacy in mouse models of Alzheimer's disease (AD).

Microglial activation facilitates Abeta plaque removal following intracranial anti-Abeta antibody administration.

The mechanisms by which anti-Abeta antibodies clear amyloid plaques in Abeta depositing transgenic mice are unclear. In the current study, we demonstrate that inhibition of anti-Abeta antibody-induced microglial activation with anti-inflammatory drugs, such as dexamethasone, inhibits removal of fibrillar amyloid deposits. We also show that anti-Abeta F(ab')(2) fragments fail to activate microglia and are less efficient in removing fibrillar amyloid than the corresponding complete IgG. Diffuse Abeta deposits are cleared by antibodies under all circumstances. These data suggest that microglial activation is necessary for efficient removal of compact amyloid deposits with immunotherapy. Inhibition of this activation may result in an impaired clinical response to vaccination against Abeta.