Characteristic differences between patients who have undergone surgical treatment for lung metastasis or hepatic metastasis from colorectal cancer.

OBJECTIVE: The characteristic differences between patients with lung or liver metastases from colorectal carcinoma (CRC) have not yet been clarified. A small group of these patients demonstrate a better prognosis, and the selection criteria for resection of liver and/or lung metastasis are not well defined. It is important to compare and analyze the most common metastatic sites, which include liver metastases and lung metastases. The objective of this study was to compare the characteristics of the two groups in order to identify patients who benefitted from surgical resection of CRC. METHODS: We retrospectively reviewed the medical charts of 80 patients who had undergone resection for liver or lung metastasis from CRC in Fukuoka University Hospital between June 1991 and December 2004. These patients were grouped according to surgical therapy received for the metastases, and separated into two groups, as follows: LUM, lung metastases resection; LIM, liver metastases resection. We evaluated these groups for a set of several factors. RESULTS: The characteristic factors between the two groups (LUM vs. LIM) demonstrated significant differences according to histological differentiation, venous invasion, and lymphatic permeation. There was a statistical difference in the disease-free interval (DFI) between the two groups (947.06 +/- 840.39 days in LUM vs. 246.03 +/- 229.26 days in LIM). Although serum CEA levels at resection of metastasis showed significant differences between the groups (LUM, 13.25 +/- 31.55 ng/ml; LIM, 55.21 +/- 99.52 ng/ml), the primary serum CEA levels were not significantly different. Overall survival rates at 5 years were 37.0 % for LUM and 42.8 % for LIM. There was no significant difference in the survival rate of the LUM vs. the LIM group after resection of metastasis. The Cox proportional hazards regression model was used to determine serum CEA status at the time of the metastases and showed a significant difference indicating poor prognosis for patients with LUM, but the results were not significant for LIM cases. CONCLUSIONS: Candidates for surgical treatment for lung or liver metastases from CRC may be an acceptable for the same valuable approach, even if characteristic differences were observed in each group.

Application of dye-enhanced laser ablation for liver resection. Production of protein sealant on the cut surface of the liver by enhanced thermal energy of low power diode laser.

BACKGROUND: Dye-enhanced laser ablation (DLA) using a low-power diode laser for indocyanine green (ICG)-stained tissue has proven its effectiveness in dye-enhanced laser photocoagulation of retinal vessels or endoscopic surgical mucosectomy. We have applied DLA in hepatectomy and described its histological distinction in comparison with the cavitron ultrasonic surgical aspirator (CUSA). METHODS: A diode laser (UDL-60 Laser unit, Olympus, Tokyo, Japan) with 810 +/- 20 nm wavelength was employed for this study. The ICG dye (Diagnogreen, Daiichi Pharmaceutical, Tokyo, Japan) with a peak absorption wavelength at 800-810 nm was injected topically into the resection plane of the liver. The liver tissue was divided by touching the tip of the diode laser. Three different concentrations of ICG solution such as 2.0, 1.0 and 0.5 mg/ml were tested in the preliminary animal experiment. The use of a low-power diode laser at 10 W with an ICG concentration of 0.5 mg/ml was the appropriate combination for liver resection. In the clinical series, 27 hepatectomies were performed by DLA, and 10 with CUSA. RESULTS: DLA demonstrated smooth cutting and good hemostasis in liver resection. Among the hepatectomy cases given DLA, no postoperative hemorrhage or bile leakage was noted. The postoperative hospital stay was significantly shorter in the DLA than the CUSA group. The cut surface of the liver was sealed microscopically with a layer of protein coagulum. CONCLUSIONS: A layer of protein sealant on the cut surface of the liver contributes to the short postoperative hospital stay when using DLA.

Adeno-endocrine cell carcinoma of the gallbladder.

We encountered a rare case of adeno-endocrine cell carcinoma of the gallbladder in an 81-year-old woman. Imaging study revealed a common bile duct stone. Endoscopic sphincterotomy was performed, and the stone was extracted successfully. Thereafter, cholecystectomy was performed. A papillary tumor was found in the neck of the gallbladder. Histologically, the tumor consisted of two components, well differentiated adenocarcinoma and endocrine cell carcinoma. However, no clinical signs of tumor hormonal activity were observed. The tumor cells in the area of the endocrine cell carcinoma were small and round. Histochemical studies of these tumor cells were positive for chromogranin A and Grimelius silver impregnation. The tumor cells in the area of the adenocarcinoma were well differentiated adenocarcinoma and included goblet-type cells with a tubular structure or solid growth pattern. These adenocarcinoma cells stained positively for Alcian blue and periodic acid-Schiff, and both types of tumor cells stained positively for carbohydrate antigen and carcinoembryonic antigen. It was suggested that the histogenesis of the endocrine cell carcinoma of the gallbladder was closely related to that of the adenocarcinoma.

Resectable carcinoma of the pancreatic head developing 7 years and 4 months after distal pancreatectomy for carcinoma of the pancreatic tail.

A 67-year-old woman was referred with an abnormal finding on an abdominal echogram but presented with no symptoms; a pancreatic tail tumor was detected by ultrasonography. Biochemical examinations showed slight elevation of serum carcinoembryonic antigen level. The lesion was resected by tail and body pancreatectomy and her postoperative course was uneventful. Seven years and 4 months after the initial operation, however, her serum level of carbohydrate antigen 19-9 was found to be elevated, and a recurrence of pancreatic cancer was suspected. Examinations revealed a mass in the head of the remnant pancreas. The lesion was radically resected by total remnant pancreatectomy. Histological examinations showed that the initial tumor was a well differentiated tubular adenocarcinoma, while the second tumor was characterized as a moderately differentiated tubular adenocarcinoma. The surgical margins of the distal pancreatectomy specimen were free of atypical cells. Therefore, the position of the second lesion diminished the likelihood that it had developed by intrapancreatic metastasis. This suggests that the second carcinoma in the head of the pancreas may have been a second primary lesion.

In vitro B-mode ultrasonographic criteria for diagnosing axillary lymph node metastasis of breast cancer.

Axillary lymph node status is an important factor for staging and treatment planning in breast cancer. Our study was performed in vitro on a node-by-node basis to evaluate the ability of B-mode ultrasonographic images to distinguish metastatic from nonmetastatic nodes. Immediately prior to histologic examination, individual dissected axillary nodes were scanned in a water bath using a 10 MHz B-mode ultrasonographic transducer. Four B-mode features (size, circularity, border demarcation, and internal echo) were evaluated for their ability to distinguish metastatic from nonmetastatic lymph nodes. Lymph node metastasis was indicated by (1) a large size (i.e., a length of the longest axis of 10 mm or greater); (2) a circular shape (i.e., the ratio of the shortest axis to the longest axis between 0.5 and 1.0); (3) a sharply demarcated border compared with surrounding fatty tissue; and (4) a hypoechoic internal echo, with obliteration of the fatty hilum. The sensitivity and specificity were compared for all combinations of features. We examined 84 histologically characterized axillary nodes from 27 breast cancer patients, including 64 nonmetastatic and 20 metastatic nodes. Of the criteria cited, circular shape was the best single feature for distinguishing metastatic from nonmetastatic nodes (sensitivity, 65%; specificity, 73%). The best combination of sensitivity (85%) and specificity (73%) was obtained using the criterion that a lymph node contained cancer when at least three positive features were present. The present in vitro study demonstrated that the sensitivity and specificity of B-mode ultrasonography for diagnosing lymph node metastasis were lower than 90%. Therefore, B-mode ultrasonography may not be an optimal noninvasive screening method for diagnosing axillary lymph node metastasis in breast cancer patients, particularly under in vivo clinical conditions.

In vitro diagnosis of axillary lymph node metastases in breast cancer by spectrum analysis of radio frequency echo signals.

Axillary lymph node status is of particular importance for staging and managing breast cancer. Currently, axillary lymph node dissection is performed routinely in cases of invasive breast cancer because of the lack of accurate noninvasive methods for diagnosing lymph node metastasis. We investigated the diagnostic ability of ultrasonic tissue characterization based on spectrum analysis of backscattered echo signals to detect axillary lymph node metastasis in breast cancer in vitro compared with in vitro B-mode imaging. Immediately after surgery, individual lymph nodes were isolated from axillary tissue. Each lymph node was scanned in a water bath using a 10-MHz instrument, and radio frequency data and B-mode images were acquired. Spectral parameter values were calculated, and discriminant analysis was performed to classify metastatic and nonmetastatic lymph nodes. Forty histologically characterized axillary lymph nodes were enrolled in this study, including 25 nonmetastatic and 15 metastatic lymph nodes. A significant difference existed in the spectral parameter values (slope and intercept) for metastatic and nonmetastatic lymph nodes. Spectral parameter-based discriminant function classification of metastatic vs. nonmetastatic lymph nodes provided a sensitivity of 93.3%, specificity of 92.0%, and overall accuracy of 92.5%. In comparison, B-mode ultrasound images of in vitro lymph nodes provided a sensitivity of 73.3%, specificity of 84.0%, and overall accuracy of 80.0%. Receiver operating characteristic (ROC) analysis comparing the efficacy of both methods gave an ROC curve area of 0.9888 for spectral methods, which was greater than the area of 0.8980 for B-mode ultrasound. Hence, this in vitro study suggests that the diagnostic ability of spectrum analysis may prove to be markedly superior to that of B-mode ultrasound in detecting axillary lymph node metastasis in breast cancer. Because of these encouraging results, we intend to conduct an investigation of the ability of spectral methods to classify metastatic axillary lymph nodes in vivo.

In vitro investigation of lymph node metastasis of colorectal cancer using ultrasonic spectral parameters.

Lymph node involvement is one of the major factors affecting the prognosis of colorectal cancer. Various imaging methods, including ultrasound and computed tomography, are not sufficiently sensitive or specific for reliably determining lymph node involvement. We investigated the feasibility of using ultrasonic tissue characterization (UTC) based on spectrum analysis of backscattered echo signals for diagnosing lymph node metastasis of colorectal cancer in vitro. Forty lymph nodes, including 17 metastatic and 23 nonmetastatic nodes, from 11 colorectal cancer operations were investigated. Lymph nodes were scanned using a clinical instrument; B-mode imaging was performed for each lymph node, and radiofrequency (RF) data were acquired. The UTC parameters, slope and intercept, were calculated from the normalized power spectrum of the backscattered echo signals from each lymph node. The mean values of UTC parameters of metastatic and nonmetastatic lymph nodes were compared. The accuracy of UTC in distinguishing metastatic from nonmetastatic lymph nodes was calculated using discriminant analysis. Receiver operating characteristic (ROC) analysis was performed to compare the classification efficacy of UTC and B-mode ultrasound. UTC parameters demonstrated a significant difference in parameter values between metastatic and nonmetastatic lymph nodes. The overall accuracy in diagnosing the lymph node metastasis was 87.5% for UTC and 77.5% for B-mode ultrasound. ROC analysis produced an ROC curve area of 0.92 or 0.89 for UTC (depending on the performance-assessment algorithm) and 0.84 for B-mode ultrasound, which indicated that UTC performed markedly better than B-mode ultrasound in diagnosing metastatic lymph nodes. The advantages of UTC over conventional B-mode ultrasound in discriminating metastatic lymph nodes from nonmetastatic lymph nodes are extremely encouraging, and warrant an in vivo UTC study.

In vivo detection of carotid plaque thrombus by ultrasonic tissue characterization.

The purpose of the study was to determine whether ultrasonic tissue characterization could detect carotid plaque thrombus in vivo. Patients undergoing carotid endarterectomy were examined preoperatively and the ultrasonic tissue characterization findings were compared to those of optical microscopy of the removed plaque specimens. Ten of 15 patients studied had plaque thrombus. Ultra-ultrasonic tissue characterization entailed an analysis of parameters obtained from the power spectrum of backscattered ultrasound signals. Data were obtained with a nominal 10 MHz sector scanning transducer with an effective bandwidth of 3 to 13 MHz. The parameters were the slope and intercept derived from the linear regression of the normalized spectrum and total power (log of the integrated power of the normalized spectrum over the effective bandwidth). The combined effect of the three parameters was determined by discriminant function analysis and showed a significant difference (P < 0.05) between nonthrombus and plaque thrombus in a small sample of patients with advance carotid atherosclerosis. These parameters applied singly could not provide such a distinction. Correct classification of carotid plaque thrombus using the multiple-parameter analysis revealed a sensitivity of 90%, specificity of 80%, and accuracy of 86.7%. This study demonstrates that analysis utilizing a combination of multiple spectral parameters was able to detect carotid plaque thrombus in vivo.

Carotid plaque typing by multiple-parameter ultrasonic tissue characterization.

We evaluated the ability of ultrasonic tissue characterization (UTC), based on backscattered echo signals, to distinguish among the components of advanced carotid plaques. We performed spectral analysis of echo signals acquired from human carotid endarterectomy specimens in vitro to calculate three parameters of the calibrated power spectrum: slope, intercept and total power for fibrous, lipid pool and thrombus constituents of plaque. Plaque constituents were identified histologically. We evaluated classification efficacy by discriminant function analysis. Slope and intercept parameters alone provided correct classification in 92.5%, 57.6% and 72.4% of fibrous, lipid pool and thrombus plaque components, respectively. Slope, intercept and total power used in combination improved classification of the three tissue types to 93.0%, 69.7% and 81.0%. The overall proportion of correctly classified tissue regions increased from 84.5% to 88.0% by the combined use of the three parameters. The improvement in classification that occurred when we included total power as a third parameter suggests that ultrasound plaque components may not consist solely of small, randomly distributed isotropic scatterers. Our ability to identify plaque thrombi provides motivation for future studies of parameter-based imaging methods for identifying such plaque that presents an increased risk of embolic neurologic ischemic events.

Technique of laparoscopic ultrasound examination of the liver and pancreas.

Since the introduction of a recent laparoscopic ultrasound (LU), the value of this modality in examining the liver and pancreas has been reported. However, a precise scanning technique of LU has not previously been described. Based on our experience with intraoperative ultrasound during laparotomy, we have developed a technique for complete examination of the entire organs using a rigid LU probe. A 7.5-MHz rigid probe, 10 mm in diameter, was employed. The scanning was performed through three trocar ports: right subcostal, subxiphoid, and umbilical. For the liver, the subcostal scanning provided fundamental transverse views. The subxiphoid and umbilical scanning delineated the areas unable to be imaged by the subcostal scanning. For the pancreas, the subcostal and umbilical scanning demonstrated longitudinal and transverse views, respectively. The subxiphoid scanning enhanced examination of the pancreatic head. Three basic probe maneuvers (advancement-withdrawal, lateral movement, and rotation) and various scanning techniques (contact, probe-standoff, and compression scanning) should be utilized appropriately. With a rigid probe, complete LU examination of the liver and pancreas is possible using these techniques. We believe the present scanning method will help more surgeons learn LU.