A randomised clinical trial of routine versus selective CT imaging in acute abdomen: Impact of patient age on treatment costs and hospital resource use.

OBJECTIVES: To evaluate the impact of patient age on hospital resource use and treatment costs of acute abdominal pain (AAP). MATERIALS AND METHODS: A total of 300 adult patients with AAP were randomised to either computed tomography (CT, n=150) or selective imaging practice (SIP, n=150) groups. Final analysis included 254 patients, 143 (42 patients ≥65years) in the CT and 111 (32 patients ≥65years) in the SIP group. All CT group patients underwent abdominal CT whereas in the SIP group, imaging was based on the clinical assessment. For each patient, the hospital length of stay (LOS), the numbers and costs of diagnostic and treatment procedures arising from AAP were calculated and registered. The incremental cost-effectiveness ratio (ICER) and bootstrapped cost-effectiveness acceptability curve (CEAC) were estimated for routine CT. RESULTS: Treatment costs, imaging costs and LOS increased in conjunction with aging in both study groups, and were generally higher in the CT group compared to the SIP group. In the SIP group, CT was undertaken in 34% (27/79) of the <65year olds but in 59% (19/32) of the older patients (≥65years) (p=0.02). The proportion of patients with non-specific abdominal pain was significantly lower in patients ≥65years than in their younger counterparts (p=0.04). In the routine CT group, the ICER of obtaining a specific diagnosis was 1682 € for patients <65years and 1055 € for patients ≥65years. According to CEAC estimation, routine CT for every patient with AAP has a 95% probability of being cost-effective if society is willing to pay 14087 € for an additional specific diagnosis for patients <65 years but only 4204 € in those ≥65years. CONCLUSION: Treatment costs of AAP increase in parallel with aging, and the costs are generally higher with routine CT compared to selective imaging. The probability of obtaining a specific diagnosis of AAP increases with aging. If obtaining a specific diagnosis is deemed crucial, then routine CT is more cost-effective in patients over 65 years compared to younger patients. Considering the diagnostic challenges of AAP in the elderly, liberal CT use can be advocated in this patient group.

Interpretation of Abdominal CT Findings in Patients Who Develop Acute on Chronic Mesenteric Ischemia.

BACKGROUND: We studied whether ischemia-specific computed tomography (CT) findings are consistently detectable in patients who develop acute on chronic mesenteric ischemia (AOCMI), whereas absent in chronic mesenteric ischemia (CMI). METHODS: Consecutive patients with symptomatic angiography-verified atherosclerotic obstruction of the superior mesenteric artery (SMA) were categorized as AOCMI (n = 27) or CMI (n = 20). Three experienced radiologists blindly evaluated the contrast-enhanced CTs for vascular and intestinal findings. Kappa statistics was used to test interobserver agreement. RESULTS: Two observers had substantial agreement (k = 0.66) that two thirds of AOCMI patients showed ischemia-specific CT findings (decreased bowel wall enhancement, pneumatosis, or thrombotic SMA clot); the third observer agreed only fairly regarding pneumatosis and thrombosis (k = 0.3-0.4). All observers had substantial agreement (k = 0.65-0.71) that most patients with AOCMI had unspecific intestinal findings such as mesenteric fat stranding in up to 96%, bowel lumen dilatation in 93%, and bowel wall thickening in 70%, while only few patients with CMI had such findings (due to chronic ischemic colitis) (P < 0.001). CONCLUSION: One third of AOCMI patients presented without any ischemia-specific CT signs. However, any intestinal abnormality in CT together with SMA obstruction should raise suspicion of intestinal ischemia. Furthermore, clinicians need to be aware of the interobserver variability in the CT interpretation.

Acute Mesenteric Ischemia Is a More Common Cause than Expected of Acute Abdomen in the Elderly.

BACKGROUND: The incidence of acute mesenteric ischemia (AMI) increases exponentially with age. The significance of AMI as a differential diagnosis in elderly patients with acute abdomen may be underestimated. METHODS: Consecutive patients hospitalized for AMI between 2009 and 2013 were retrospectively identified in a well-defined population. Acute appendicitis, ruptured abdominal aortic aneurysm, acute pancreatitis, and acute cholecystitis were used as reference diagnoses, and the age-specific incidence rates were calculated. In addition, long-term mortality risk was assessed for AMI survivors. RESULTS: The in-hospital incidence rates of AMI, acute obstructive mesenteric ischemia, and non-obstructive mesenteric ischemia were 7.3, 4.5, and 2.0/100,000/year, respectively. AMI was more common than ruptured abdominal aortic aneurysm, and the age-specific incidence of AMI was higher than the incidence of acute appendicitis in patients over age 75 years with acute abdomen. During the follow-up, the age-adjusted risk of death was 1.8 times higher in AMI survivors than in survivors of acute cholecystitis. CONCLUSION: AMI may be a more common cause of acute abdomen in elderly patients than is generally thought, emphasizing the importance of performing urgent computed tomography with contrast enhancement preferably in arterial and venous phases in these patients.

Detecting acute mesenteric ischemia in CT of the acute abdomen is dependent on clinical suspicion: Review of 95 consecutive patients.

OBJECTIVES: (1) To evaluate the ability of emergency room radiologists to detect acute mesenteric ischemia (AMI) from computed tomography (CT) images in patients with acute abdominal pain. (2) To identify factors affecting radiologists' performance in the CT interpretation and patient outcome. MATERIALS AND METHODS: A retrospective study of 95 consecutive patients treated for 97 AMI events between 2009 and 2013 was carried out. The etiology of AMI was embolism in 24 (25%), atherosclerotic vascular disease (ASVD) in 39 (40%), non-obstructive mesenteric ischemia (NOMI) in 25 (26%), and mesenteric venous thrombosis (MVT) in nine (9%) cases. The protocols, referrals and initial radiology reports of the abdominal CTs were analyzed. The CT studies were further scrutinized for vascular and intestinal findings. RESULTS: The referring clinician had suspected AMI in 30 (31%) cases prior to imaging. The crucial findings of AMI had been stated in 97% of the radiology reports if the clinician had mentioned AMI suspicion in the referral; if not, the corresponding rate was 81% (p=0.04). Patients without suspicion of AMI prior to CT were more prone to undergo bowel resection. CT protocol was optimal for AMI (with contrast enhancement in arterial and venous phases) in only 34 (35%) cases. Intestinal findings were more difficult to detect than vascular findings. Vascular findings were retrospectively detectable in 92% of cases with embolism and 100% in ASVD and MVT. Some evidence of intestinal abnormality was retrospectively found in the CT findings in 92%, 100%, 100% and 67% of cases with embolism, ASVD, NOMI and MVT, respectively. CONCLUSIONS: AMI is underdiagnosed in the CT of the acute abdomen if there is no clinical suspicion.

Endovascular Therapy as a Primary Revascularization Modality in Acute Mesenteric Ischemia.

PURPOSE: To evaluate endovascular therapy (EVT) as the primary revascularization method for acute mesenteric ischemia (AMI). METHODS: A retrospective review was performed on all consecutive patients treated for AMI during a 5-year period (January 2009 to December 2013). EVT was attempted in all patients referred for emergent revascularization. Surgical revascularization was performed selectively after failure of EVT. Patient characteristics, clinical presentation, and outcomes were studied. Failures and complications of EVT were recorded. RESULTS: Fifty patients, aged 79 ± 9 years (mean ± SD), out of 66 consecutive patients with AMI secondary to embolic or thrombotic obstruction of the superior mesenteric artery were referred for revascularization. The etiology of AMI was embolism in 18 (36 %) and thrombosis in 32 (64 %) patients. EVT was technically successful in 44 (88 %) patients. Mortality after successful or failed EVT was 32 %. The rates of emergency laparotomy, bowel resection, and EVT-related complication were 40, 34, and 10 %, respectively. Three out of six patients with failure of EVT were treated with surgical bypass. EVT failure did not significantly affect survival. CONCLUSIONS: EVT is feasible in most cases of AMI, with favorable patient outcome and acceptable complication rate.