technetium-tc-99m-exametazime and Gastrointestinal-Hemorrhage

To compare the thrombogenicity and patency of the Palmaz stent and the Wallstent, and to evaluate the effect of periprocedural heparin therapy in cirrhotic patients with maintained coagulation capacity who receive a transjugular intrahepatic portosystemic shunt (TIPS).. Twenty-four patients were randomized into 4 groups of 6 patients. Each received a Palmaz-stent or Wallstent TIPS with or without periprocedural heparin therapy. The groups receiving periprocedural heparin were given 24 U/kg b.w. just before stent placement, followed by 24 h therapeutic i.v. heparin. After 24 hours, all patients received i.v. heparin for 1 week followed by subcutaneous treatment with low-molecular-weight heparin (0.3 ml/day) for another 4 weeks. Stent thrombogenicity was determined scintigraphically after i.v. injection of 120-290 mBq of 99mTc-labeled platelets at the time of stent placement and expressed as the stent/heart ratio. Shunt patency was assessed by duplex sonography and confirmed radiologically.. The aggregation ratio was highest 90 min after stent implantation. Wallstents showed a significantly higher ratio than Palmaz stents. Heparin reduced the ratio in patients with a Wallstent (-41%) but had no effect on Palmaz stents. Patients with a Wallstent without heparin had a higher rate of early shunt insufficiency (66.6%) than the other patients (0-16.6%). Primary assisted long-term patency was similar in the 4 groups.. Wallstents were more thrombogenic than Palmaz stents and gave a significantly higher risk of early shunt insufficiency in cirrhotic patients with maintained coagulation capacity. Periprocedural heparin was effective in the prevention of shunt insufficiency and is therefore indicated in such patients.

Topics: Anticoagulants; Blood Platelets; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Humans; Intraoperative Care; Liver Cirrhosis; Male; Middle Aged; Organotechnetium Compounds; Oximes; Platelet Aggregation; Portal System; Portasystemic Shunt, Transjugular Intrahepatic; Postoperative Care; Radionuclide Imaging; Stents; Technetium Tc 99m Exametazime; Thrombosis; Ultrasonography

A 50-year-old-man with abdominal pain, who had undergone aortic aneurysm reconstructive surgery (aortic graft) 3 years before, was admitted to the hospital. A CT scan showed findings suggestive of perigraft infection. Scintigraphy with 99mTc-hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes confirmed the diagnosis of aortic graft infection and documented an active concurrent bleeding in the gastrointestinal tract from a secondary aortoenteric fistula. This case illustrates the diagnosis of the precise location of the source of bleeding from aortoenteric fistula by leukocyte scintigraphy. The images aided the surgical team by revealing the aortic site of bleeding and the severity of the problem.

Topics: Contrast Media; Gastrointestinal Hemorrhage; Humans; Incidental Findings; Intestinal Fistula; Leukocytes; Male; Middle Aged; Radionuclide Imaging; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed; Vascular Fistula

This study assesses the causes of colonic localization of labeled white blood cells (WBCs) in critically ill patients who had undergone leukocyte scintigraphy for suspected infection. Forty-two patients showed abdominal or pelvic WBC localization; 20 of these had a pattern of colonic localization, and some also showed a pattern of small bowel activity. Eight of the 20 patients had documented gastrointestinal bleeding. White blood cell scintigraphy in these eight patients showed a pattern of multifocal and/or regional bowel activity that changed in intensity and location from early (3-5-hour) to delayed (18-28-hour) images. In contrast, 5 of the 6 patients with documented pseudomembranous colitis (PMC) showed intense WBC localization involving most of the colon. In 3 of these 5 patients, early and delayed images were acquired and showed a relatively constant pattern of WBC localization. The sixth PMC patient had been treated with vancomycin before leukocyte scintigraphy and showed minimal distal small bowel activity on early images and only mild regional colonic activity on delayed images. As in the patients with gastrointestinal bleeding, the remaining six patients showed either focal or regional activity of variable intensity that changed over time. In critically ill patients, gastrointestinal bleeding and PMC accounted for 14 of the 20 patients in which labeled leukocyte scintigraphy exhibited colonic activity. A pattern of diffuse, intense colonic radiotracer activity which persists from early to delayed imaging strongly suggests the presence of PMC in this patient population.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Clostridioides difficile; Colon; Enterocolitis, Pseudomembranous; Female; Gastrointestinal Hemorrhage; Humans; Indium Radioisotopes; Leukocytes; Male; Middle Aged; Organometallic Compounds; Organotechnetium Compounds; Oximes; Oxyquinoline; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Time Factors

Clinical applications for Tc-99m HMPAO labeled red blood cells have not been previously reported. The authors describe a simple, aseptic, closed, one-step centrifugal procedure for red blood cell labeling with Tc-99m HMPAO and isolation from whole blood, and they report the preliminary results of using these labeled red blood cells to detect acute gastrointestinal bleeding in 11 patients. Whole blood was radiolabeled with Tc-99m HMPAO preparation and blood cells were separated by centrifugation (30 min, 200 g, 20 degrees C) using Polyprep density gradient medium. Red blood cells contained about 50% of the radioactivity. Four out of the 11 patients imaged with a gamma camera after reinjection of labeled autologous red blood cells showed abnormal accumulation, suggesting gastrointestinal bleeding that was verified at surgery and was at the site of abnormal activity in all cases. Image quality with Tc-99m HMPAO was comparable to that of Tc-99m pertechnetate labeled pretinned red blood cells. Tc-99m HMPAO can be used as a red blood cell labeler; however, its elution rate from red blood cells limits its applicability in some investigations.

Topics: Adult; Centrifugation, Density Gradient; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Isotope Labeling; Male; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Exametazime