BUN/creatinine ratios: aid to decision making about delayed imaging in Tc-99m red blood cell scans for gastrointestinal hemorrhage

Gastrointestinal Bleeding Scintigraphy in the Early 21st Century

Gastrointestinal bleeding scintigraphy performed with (99m)Tc-labeled autologous erythrocytes or historically with (99m)Tc-sulfur colloid has been a clinically useful tool since the 1970s. This article reviews the history of the techniques, the different methods of radiolabeling erythrocytes, the procedure, useful indications, diagnostic accuracy, the use of SPECT/CT and CT angiography to evaluate gastrointestinal bleeding, and Meckel diverticulum imaging. The causes of pediatric bleeding are discussed by age.

Patient characteristics with high or low blood urea nitrogen in upper gastrointestinal bleeding

AIM: To examine characteristics of patients with blood urea nitrogen (BUN) levels higher and lower than the normal limit.

METHODS: Patient records between April 2011 and March 2014 were analyzed retrospectively. During this time, 3296 patients underwent upper endoscopy. In total, 50 male (69.2 ± 13.2 years) and 26 female (72.3 ± 10.2 years) patients were assessed. Patients were divided into two groups based on BUN levels: higher than the normal limit (21.0 mg/dL) (H) and lower than the normal limit (L). One-way analysis of variance was performed to reveal differences in the variables between the H and L groups. Fisher’s exact test was used to compare the percentage of patients with gastric ulcer or gastric cancer in the H and L groups.

RESULTS: White blood cell count was higher in the H group than in the L group (P = 0.0047). Hemoglobin level was lower in the H group than in the L group (P = 0.0307). Glycated hemoglobin was higher in the H group than in the L group (P = 0.0264). The percentage of patients with gastric ulcer was higher in the H group (P = 0.0002). The H group contained no patients with gastric cancer.

CONCLUSION: Patients with BUN ≥ 21 mg/dL might have more severe upper gastrointestinal bleeding.

Value of Tc-99m-labeled red blood cells scintigraphy in diagnosis of gastrointestinal bleeding

AIM: To retrospectively study the value of technetium-99m-labeled red blood cell scinti-graphy in the localization of gastrointestinal bleeding.

METHODS: A total of 42 patients received Tc-99m RBC scintigraphy for the localization of gastrointestinal bleeding from January 2000 to December 2005, of which 17 cases were confirmed by surgical and endoscopic findings. The data obtained by Tc-99m RBC scintigraphy and the final results were comparatively analyzed.

RESULTS: Of the 17 cases confirmed by operation and endoscopy, 4 were found with perfect matches with the data of Tc-99m RBC scintigraphy, 6 with general matches and 7 without matches. The overall match ratio was 58.8% (10/17). The mismatches between Tc-99m RBC scintigraphic and endoscopic/surgical findings included 4 aspects: inaccurate localization of gastrointestinal bleeding, unknown abdominal radioactivity, false-positive and false-negative diagnosis.

CONCLUSION: Two steps are keys to avoid the diagnostic pitfall in the localization of gastrointestinal bleeding: to know the intestine anatomy; to view the obscure radioactivity in left upper adomen carefully.

Recurrent gastrointestinal bleeding diagnosed by delayed scintigraphy with Tc-99m-labeled red blood cells

A 56-year-old woman presented with bright-red blood from the rectum. Esophagogastroduodenoscopy revealed mild gastritis. Colonoscopy demonstrated diverticulosis without active bleeding, and in vitro tagged red blood cell scintigraphy was unremarkable. There was no further evidence of bleeding and the patient was discharged home. The patient returned with recurrent bright-red blood from the rectum. Although delayed scintigraphic images seldom demonstrate the site of bleeding, delayed images at 12 hours demonstrated active bleeding near the hepatic flexure in this patient. This was confirmed with selective mesenteric angiography, and was treated with coil embolization of the tertiary branches of the right middle colic artery.

Delayed 99mTc-labeled erythrocyte scintigraphy in patients with lower gastrointestinal tract hemorrhage: effect of positive findings on clinical management

RATIONALE AND OBJECTIVES

This study was performed to determine whether the results of delayed technetium 99m (99mTc)-labeled erythrocyte scintigraphy for lower gastrointestinal tract hemorrhage resulted in different clinical management and outcome from that in cases in which the results of initial scintigraphy were negative or equivocal.

MATERIALS AND METHODS

The authors retrospectively reviewed all 398 99mTc-labeled erythrocyte scintigraphic studies obtained emergently for lower gastrointestinal tract hemorrhage at their institution between January 1, 1994, and December 7, 2001. Of 67 patients who underwent delayed studies, 37 had positive findings (average delay, 18.4 hours; range, 6-25 hours) and 30 had negative findings (average delay, 20.1 hours; range, 8-26 hours). Clinical management and outcome were compared between these two groups with respect to duration of hospitalization, volume of blood transfusion, mortality, and the percentage who were treated conservatively or referred for angiography, endoscopy, and/or surgery.

RESULTS

Patients with positive delayed studies were referred more frequently for angiography than those with negative studies (35% vs 0%, P < .01). There were no significant differences between patients with positive findings and patients with negative findings with respect to mortality (8% vs 0%, P < .32), transfusion requirements (5.6 vs 3.2 units, P < .20), hospitalization (9.5 vs 6.1 days, P < .11), the percentage treated conservatively (35% vs 37%, P < .90), or the percentages referred for endoscopy (49% vs 60%, P < .50) or for surgery (24% vs 17%, P < .64).

CONCLUSION

Positive findings at delayed scintigraphy resulted in increased referrals for angiography but had no other effect on clinical course or outcome of lower gastrointestinal tract hemorrhage.

Massive lower gastrointestinal hemorrhage from the surgical anastomosis in patients with multiorgan trauma: treatment by subselective embolization with polyvinyl alcohol particles

PURPOSE

To evaluate the efficacy and safety of subselective arterial embolization with polyvinyl alcohol (PVA) particles with or without microcoil augmentation to control postoperative lower gastrointestinal (GI) bleeding.

METHODS

Ten patients with clinical, scintigraphic, and angiographic evidence of postoperative lower GI bleeding were considered for subselective embolization. Subselective embolizations were performed through coaxial microcatheters with 355-500 micron PVA particles with or without additional coil embolization.

RESULTS

Embolization was technically successful in 9 of 10 (90%) patients. In one patient, subselective embolization was not possible; consequently no embolization was performed. Clinical success was achieved after a single embolization in 6 of 10 (60%) patients and after a second embolization in an additional 3 of the 10 (30%) patients. While there was no rebleeding in patients with normal coagulation parameters, all three patients (100%) with coagulopathy rebled, two of them from another source. Although no acute ischemic effects developed, no long-term sequela such as ischemic stricture were specifically looked for. Seven patients developed abdominal discomfort and/or fever within 24-48 hr. Four of 10 patients died of complications other than hemorrhage or ischemia.

CONCLUSION

Subselective PVA embolization with or without a microcoil embolization is an effective and safe means of managing postoperative lower GI hemorrhage in patients with multiorgan trauma.