Imaging of gastrointestinal stromal tumors before and after imatinib mesylate therapy.

Gastrointestinal stromal tumors (GISTs) account for the majority of gastrointestinal mesenchymal tumors. Recent advances in treatment using the molecular targeting agent imatinib mesylate have shown startling response rates and variegated imaging findings. We present the various imaging appearances of GIST on computed tomography (CT) and magnetic resonance imaging (MRI), both before and after treatment.

Interventional radiology in the chest.

Interventional radiologic techniques offer many options and benefits in the care of patients with thoracic disorders. Imaging-guided catheter techniques provide heretofore unsurpassed precision and accuracy in performance of these procedures. Improved efficacy, with reduced morbidity is the goal and usually the result for the patient.

Interventional gallbladder procedures.

Interventional radiologic procedures in the gallbladder are influencing both the diagnosis and therapy of many gallbladder disorders. Current diagnostic and therapeutic percutaneous techniques offer important alternatives for their management. This article highlights the spectrum of interventional radiologic techniques available for gallbladder diseases.

Interventional ultrasound in the musculoskeletal system.

This article highlights the multiple applications of ultrasound as a guidance modality for interventional procedures in the musculoskeletal system. The percutaneous aspiration, drainage, and biopsy of musculoskeletal abscesses, masses, and focal muscular pathology in the extremities, trunk, and neck using ultrasound as the guidance system is described. Techniques for biopsy, fluid aspiration, catheter insertion, and needle visualization by ultrasound are discussed.

Drainage of intraabdominal abscesses. Tactics and choices.

The experience in treating 44 intraabdominal abscesses in 30 patients using percutaneous or surgical drainage was analyzed. Ultrasonography or computerized tomography-guided percutaneous drainage was highly satisfactory for the definitive treatment of single, accessible collections. Complex, multilocular, and phlegmonous lesions can also be treated by percutaneous drainage as a temporizing measure. Abscesses that are inaccessible, contain large amounts of necrotic material or are ill-defined, as well as those that have not responded to percutaneous drainage, require surgical exploration. Using these principles, there was only one death from sepsis in this series and three significant complications.

Computed tomography of peripancreatic fat planes.

Obliteration of peripancreatic fat planes usually is considered an indicator of peripancreatic tumour infiltration in the presence of a malignant mass, or of inflammation of peripancreatic tissues in patients with pancreatitis. However, absence of peripancreatic fat planes also may be found in patients without evidence of pancreatic disease. Hence, CT scans of 125 patients without clinical or computed tomographic evidence of pancreatic disease were evaluated to assess normal variations in the anatomy of the pancreas and its relation to surrounding vessels and bowel loops. The fat plane separating the superior mesenteric artery from the pancreas was preserved in 100% of patients. Conversely, fat planes between the pancreas and the superior mesenteric vein, inferior vena cava, and adjacent bowel loops were partially or totally obliterated in 13% to 50% of patients. It is concluded that the absence of fat around the superior mesenteric artery is highly suggestive of pathologic changes of the pancreas, while the lack of fat planes between the pancreas and other splanchnic vessels or bowel loops frequently is normal, and therefore, is an unreliable sign of pancreatic disease. The applications of these findings to the assessment of tumour resectability by CT, and to CT scanning techniques, are discussed.

Percutaneous transtracheal ventilation: experimental and practical aspects.

Percutaneous transtracheal ventilation can be a lifesaving procedure when endotracheal intubation is not possible, but an understanding of the technique and necessary instruments is essential. This study, performed on adult sheep, defined the limited circumstances under which a 15-gauge needle, connected to oxygen at 50 pounds per square inch (psi), can provide an emergency transtracheal airway. There are situations, such as complete airway obstruction, when this combination is contraindicated. In addition, transtracheal ventilation might have to be performed using simpler equipment, such as a self-inflating resuscitation bag (AMBU-type) or with no equipment other than the transtracheal airway. A 3.0-mm I.D. cannula provided an adequate transtracheal airway under all circumstances examined. A 3.5-mm cannula is commercially available and physicians who deal with airway problems should be familiar with its use.

Percutaneous biliary drainage: technical and catheter-related problems in 200 procedures.

Analysis of 200 consecutive percutaneous biliary drainages revealed critical technical and clinical components not previously emphasized. In this series, successful drainage was achieved in 188 (94%) of 200 instances, and 67 (36%) of the 188 patients were discharged from the hospital without formal surgical exploration. Severe acute periprocedural complications occurred in 16 (8%) of the 200 procedures (death, three cases; septicemia, seven; and bleeding, six). Minor periprocedural complications occurred in 39 (20%) of the 200 instances (postprocedural fever, 21; hemobilia, 18). Significant delayed in-hospital complications with catheter function occurred in 22% of procedures (postclamping cholangitis, 36; catheter leaking eight). In outpatients under chronic catheter care, complications including inadvertent catheter dislodgment, tube obstruction, and cholangitis occurred at least once in most patients. Details of the etiology, prevention, and management of these major and minor complications are outlined.

Laparoscopic injuries to the bile duct. A cause for concern.

The authors report six patients who had injuries to their common hepatic bile duct at laparoscopic cholecystectomy over a 16-month period. Five of the six complications could be attributed to laser injuries during dissection in the region of Calot's triangle. The authors discuss the possible mechanism of these injuries, their perioperative management, and the methods of surgical reconstruction. The follow-up period ranges from 3 months to 21 months. Liver function parameters and isotope biliary excretion scans are back to normal in all six patients. The potential hazards of laparoscopic surgery demand that extraordinary care be used not only during the actual surgical procedure, but also in the preoperative decision concerning the dissection method to be employed.

Surgically transplanted ovary simulating a hepatic metastasis.

BACKGROUND: Surgical procedures may alter normal anatomy, confounding the interpretation of cross-sectional imaging studies. This problem is greater if neither a relevant history nor previous comparison studies are available. CASE OUTLINE: In a 29-year-old woman submitted to radical hysterectomy for cervical carcinoma, one ovary was surgically repositioned into the right paracolic gutter out of the radiation field. This ovary simulated a hepatic metastasis on subsequent CT examinations. History was obscure, adding to the interpretive challenge. DISCUSSION: Clues to establishing the correct diagnosis are presented. The availability of an adequate history and previous radiological images are important to prevent diagnostic error.

Percutaneous gastrostomy and gastroenterostomy: 2. Clinical experience.

This report describes the authors' initial experience with percutaneous gastrostomy (PG) and gastroenterostomy (PGE) in 40 patients. Indications for PG and PGE included alimentation (35 patients) and small bowel decompression (five). Seldinger technique with air distension of the stomach via a nasogastric tube (20 patients) is a simple method to insert small (7-9 French) and firm catheters; tube exchanges for larger and softer catheters often are necessary by this method (23 procedures in 17 patients). Coaxial trocar technique (19 patients) permits initial insertion of softer and often larger catheters (9-14 French feeding tubes), which are less likely to clog or require exchange; the intragastric balloon support method facilitates trocar insertion. Now preferred is a system that uses 18-gauge needle puncture and allows coaxial insertion of a final soft feeding tube at the initial procedure. Small bowel catheter positioning (PGE) (31 patients) was more common than gastrostomy alone (8 patients); "downhill puncture" toward the gastric antrum assists direct guide-wire cannulation of the duodenum via the gastric puncture (12 patients). Five complications occurred; two were major and included catheter dislodgement in one patient. Another patient, who had a pharyngeal tumor, suffered profound respiratory difficulty from premedication and nasogastric tube malposition; patients with head and neck tumors present particular problems with nasogastric tube passage and airway monitoring. Inability to pass a nasogastric tube does not preclude PG and PGE, as direct puncture of the stomach is feasible.