OBJECTIVE: The purpose of this study was to prospectively compare pre-operative computed tomography (CT) perfusion parameters with tumor grade from colorectal adenocarcinoma (CRC) and to correlate pre-operative CT perfusion parameters with microvessel density (MVD) to evaluate angiogenesis in CRC. MATERIALS AND METHODS: Pre-operative perfusion CTs were performed with a 64-channel multidetector row CT in 27 patients (17 women and 10 men; age range 32-82 years) who were diagnosed with CRC involving the sigmoid and rectum between August 2006 and November 2007. All patients underwent surgery without pre-operative chemotherapy or radiation therapy. Dynamic perfusion CTs were performed for 65 seconds after intravenous injection of contrast medium (100 mL, 300 mg of iodine per mL, 5 mL/sec). Before surgery, blood flow (BF), blood volume, mean transit time (MTT), and permeability-surface area product were measured in the tumor. After surgery, one gastrointestinal pathologist evaluated tumor grade and performed immunohistochemical staining using CD 34 to determine MVD in each tumor. The Kruskal-Wallis test was used to compare CT perfusion parameters with tumor grade, and Pearson's correlation analysis was used to correlate CT perfusion parameters with MVD. RESULTS: In 27 patients with CRC, tumor grading was as follows: well differentiated (n = 8); moderately differentiated (n = 15); and poorly differentiated (n = 4). BF was higher in moderately differentiated CRC than well differentiated and poorly differentiated CRCs (p = 0.14). MTT was shorter in moderately differentiated than well differentiated and poorly differentiated CRCs (p = 0.039). The MVD was greater in poorly differentiated than well differentiated and moderately differentiated CRCs (p = 0.034). There was no significant correlation between other perfusion parameters and tumor grade. There was no significant correlation between CT perfusion parameters and MVD. CONCLUSION: BF and MTT measurement by perfusion CT is effective in predicting moderately differentiated CRCs. However, perfusion CT is limited in distinguishing well differentiated and poorly differentiated CRCs. Pre-operative perfusion CT does not reflect the MVD of CRCs.
Adenocarcinoma/pathology/*radiography ; Adult ; Aged ; Aged, 80 and over ; Colorectal Neoplasms/pathology/*radiography ; Contrast Media/diagnostic use ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Microcirculation ; Middle Aged ; Neoplasm Grading ; Neovascularization, Pathologic/*radiography ; Prospective Studies ; Statistics, Nonparametric ; Tomography, X-Ray Computed/*methods

OBJECTIVE: To investigate the technical feasibility, clinical usefulness, and safety of a guiding sheath in fluoroscopic stent placement for patients with malignant colorectal obstructions. MATERIALS AND METHODS: Between June 2007 and January 2011, fluoroscopic placement of a dual colorectal stent was attempted in a total of 97 patients with malignant colorectal obstructions. A polytetrafluoroethylene guiding sheath was used in patients in whom a stent delivery system failed to reach the obstruction. Usefulness of the sheath was evaluated depending on whether the sheath could successfully assist the stent delivery system reach its area of interest. RESULTS: The guiding sheath was needed in 22 patients (15 men, 7 women; age range, 33-77 years; mean age, 59 years). The overall success rate for passing the sheath to the area of interest was 100%. There were no procedure-related deaths or major complications. The majority of the patients reported mild discomfort. In 2 of 22 patients with successful passing of the sheath to the area of interest, stent placement failed because of failure in the negotiation of a guide wire through the obstruction. CONCLUSION: Using a guiding sheath seems to be easy, safe and useful in fluoroscopic stent placement for patients with malignant colorectal obstructions.
Adult ; Aged ; Colorectal Neoplasms/*surgery ; Equipment Safety ; Feasibility Studies ; Female ; Fluoroscopy ; Humans ; Intestinal Obstruction/*surgery ; Male ; Middle Aged ; Polytetrafluoroethylene ; *Stents ; Treatment Outcome

OBJECTIVE: To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. MATERIALS AND METHODS: Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. RESULTS: EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. CONCLUSION: Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.
Bile Duct Diseases/*surgery/ultrasonography ; Cholangiopancreatography, Endoscopic Retrograde ; Choledochostomy/methods ; Drainage/*methods ; Endosonography/*methods ; Gastrostomy/methods ; Humans ; *Ultrasonography, Interventional

Endoscopic therapy by balloon dilation and placement of multiple large-bore plastic stents is the treatment of choice for benign biliary stricture. This approach is effective but it typically requires multiple endoscopic sessions given the short duration of stent patency. The endoscopic approach for treatment of bile leak involves the placement of a stent with or without biliary sphincterotomy. The self-expandable metal stent (SEMS) has traditionally been used for palliation of malignant biliary strictures given the long duration of stent patency owing to their larger stent diameter. Recently, SEMS has been used in a variety of benign biliary strictures and leaks, especially with the design of the covered self-expandable metal stent (CSEMS), which permits endoscopic-mediated stent removal. The use of CSEMS in benign biliary stricture could potentially result in a decrease in endoscopic sessions and it is technically easier when compared to placement of multiple plastic stents. However, complications such as cholecystitis due to blockage of cystic duct, stent migration, infection and pancreatitis have been reported. The potential subsegmental occlusion of contralateral intrahepatic ducts also limits the use of CSEMS in hilar stricture. Certain techniques and improvement of stent design may overcome these challenges in the future. Thus, CSEMS may be appropriate in only highly selected conditions, such as refractory benign biliary stricture, despite multiple plastic stent placement or difficult to treat bile duct stricture from chronic pancreatitis, and should not be used routinely. This review focuses on the use of fully covered self-expandable metal stent for benign biliary strictures and bile leaks.
*Bile ; Biliary Tract Diseases/diagnosis/etiology/*surgery ; Coated Materials, Biocompatible ; Constriction, Pathologic ; Diagnostic Imaging ; Equipment Design ; Foreign-Body Migration ; Humans ; Metals ; Plastics ; Postoperative Complications ; Sphincterotomy, Endoscopic ; *Stents

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.
Biliary Tract Diseases/*surgery ; Coated Materials, Biocompatible ; Device Removal ; Drainage/methods ; Endoscopy ; Foreign-Body Migration/surgery ; Humans ; Metals ; Postoperative Complications/surgery ; *Stents/adverse effects

As recent advances in chemotherapy and surgical treatment have improved outcomes in patients with biliary cancers, the search for an optimal strategy for relief of their obstructive jaundice has become even more important. Without satisfactory relief of biliary obstruction, many patients would be ineligible for treatment. We review all prospective randomized trials and recent retrospective non-randomized studies for evidence that would support such a strategy. For distal malignant biliary obstruction, an optimal strategy would be insertion of metallic stents either endoscopically or percutaneously. Evidence shows that a metallic stent inserted percutaneously has better outcomes than plastic stents inserted endoscopically. For malignant hilar obstruction, percutaneous biliary drainage with or without metallic stents is preferred.
Bile Duct Neoplasms/pathology/surgery ; Biliary Tract Diseases/pathology/*surgery ; Cholangiocarcinoma/pathology/surgery ; Decompression, Surgical ; Drainage/methods ; Endoscopy ; *Evidence-Based Medicine ; Hepatic Duct, Common ; Humans ; Jaundice, Obstructive/pathology/*surgery ; Klatskin's Tumor/pathology/surgery ; Stents

Major vascular complications related to pancreatitis can cause life-threatening hemorrhage and have to be dealt with as an emergency, utilizing a multidisciplinary approach of angiography, endoscopy or surgery. These may occur secondary to direct vascular injuries, which result in the formation of splanchnic pseudoaneurysms, gastrointestinal etiologies such as peptic ulcer disease and gastroesophageal varices, and post-operative bleeding related to pancreatic surgery. In this review article, we discuss the pathophysiologic mechanisms, diagnostic modalities, and treatment of pancreatic vascular complications, with a focus on the role of minimally-invasive interventional therapies such as angioembolization, endovascular stenting, and ultrasound-guided percutaneous thrombin injection in their management.
Diagnostic Imaging ; Embolization, Therapeutic/methods ; Hemostasis, Endoscopic ; Hemostatics/administration & dosage ; Humans ; Pancreatitis/*complications ; Stents ; Thrombin/administration & dosage ; Ultrasonography, Interventional ; Vascular Diseases/diagnosis/*etiology/physiopathology/*therapy ; Vascular Surgical Procedures/*methods

Bleeding from gastric varices is generally more severe than bleeding from esophageal varices, although it occurs less frequently. Recently, new endoscopic treatment options and interventional radiological procedures have broadened the therapeutic armamentarium for gastric varices. This review provides an overview of the classification and pathophysiology of gastric varices, an introduction to current endoscopic and interventional radiological management options for gastric varices, and details of a practical approach to endoscopic variceal obturation using N-butyl-2-cyanoacrylate.
Enbucrilate/*therapeutic use ; Endoscopy, Gastrointestinal/*methods ; Esophageal and Gastric Varices/*diagnosis/physiopathology/*therapy ; Gastrointestinal Hemorrhage/*diagnosis/physiopathology/*therapy ; Hemostasis, Endoscopic/*methods ; Humans ; Sclerotherapy/methods

Nonvariceal upper gastrointestinal (UGI) bleeding is a frequent complication with significant morbidity and mortality. Although endoscopic hemostasis remains the initial treatment modality, severe bleeding despite endoscopic management occurs in 5-10% of patients, necessitating surgery or interventional embolotherapy. Endovascular embolotherapy is now considered the first-line therapy for massive UGI bleeding that is refractory to endoscopic management. Interventional radiologists need to be familiar with the choice of embolic materials, technical aspects of embolotherapy, and the factors affecting the favorable or unfavorable outcomes after embolotherapy for UGI bleeding.
Angiography ; Embolization, Therapeutic/*methods ; Endoscopy, Gastrointestinal ; Gastrointestinal Hemorrhage/etiology/*therapy ; Hemostasis, Endoscopic ; Humans ; *Upper Gastrointestinal Tract

This paper focuses on new technologies that are practically useful for telemedicine. Three representative systems are introduced: a Digital Video Transport System (DVTS), an H.323 compatible videoconferencing system, and Vidyo. Based on some of our experiences, we highlight the advantages and disadvantages of each technology, and point out technologies that are especially targeted at doctors and technicians, so that those interested in using similar technologies can make appropriate choices and achieve their own goals depending on their specific conditions.
Humans ; Internet ; Remote Consultation/*instrumentation ; Software ; Telemedicine/*instrumentation/*trends ; Videoconferencing/*instrumentation