A pilot study investigating the use of 4D flow MRI for the assessment of splanchnic flow in patients suspected of mesenteric ischaemia.

The most common cause of chronic mesenteric ischaemia is atherosclerosis which results in limitation of blood flow to the gastrointestinal tract. This pilot study aimed to evaluate 4D flow MRI as a potential tool for the analysis of blood flow changes post-prandial within the mesenteric vessels. The mesenteric vessels of twelve people were scanned; patients and healthy volunteers. A baseline MRI scan was performed after 6 h of fasting followed by a post-meal scan. Two 4D flow datasets were acquired, over the superior mesenteric artery (SMA) and the main portal venous vessels. Standard 2D time-resolved PC-MRI slices were also obtained across the aorta above the coeliac trunk, superior mesenteric vein, splenic vein and portal vein (PV). In the volunteer cohort there was a marked increase in blood flow post-meal within the PV (p = 0.028), not seen in the patient cohort (p = 0.116). Similarly, there were significant flow changes within the SMA of volunteers (p = 0.028) but not for the patient group (p = 0.116). Our pilot data has shown that there is a significant haemodynamic response to meal challenge in the PV and SMA in normal subjects compared to clinically apparent CMI patients. Therefore, the interrogation of mesenteric venous vessels exclusively is a feasible method to measure post-prandial flow changes in CMI patients.

Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations.

BACKGROUND: Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography (MDCT) examination of patients with small bowel obstruction (SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques. AIM: To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia. METHODS: This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients' MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence, agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia. RESULTS: Protocol 2 resulted in more time spent and number of images than protocols 1 and 3 (P < 0.01), but the results of the two readers using the same protocol were not different (P > 0.05). Using protocol 3, both readers added multiple post-processing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1 (P < 0.01), but no difference was detected between protocols 2 and 3 (P > 0.05). The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia. CONCLUSION: Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia.

Incidence, Management, and Implications of Visceral Thrombosis in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Visceral or splanchnic thrombosis is defined as thrombi within the hepatoportal venous system, including portal (PV), mesenteric (MV), and splenic vein (SV), as well as thrombi in renal or gonadal veins. There are limited data to evaluate the prognostic significance, incidence, and clinical management of visceral thromboses in patients with pancreatic ductal adenocarcinoma (PDAC). PATIENTS AND METHODS: We conducted an analysis of 95 patients treated at Memorial Sloan Kettering Cancer Center with PDAC who had a visceral thrombosis. RESULTS: A total of 153 visceral thromboses (VsT) were identified in 95 patients (n = 51, 54% woman). A total of 36 patients (37%) had locally advanced disease, and n = 59 (62%) had metastatic disease. Systemic therapies received included FOLFIRINOX (n = 57, 60%) and GC/PTX (n = 27, 28%). All VsT events were incidentally detected. Overall survival of cohort was 12.3 months (range, 10.2-14.4 months). Visceral thrombosis incidence in the cohort was as follows: portal vein (PV) (45%), MV (26%), SV (17%), and gonadal veins (8%). Time to develop first VsT was 4.3 months (range, 3-5.6 months), and time to death from VsT development was 1.87 months (range, 0.8-2.8 months). Forty-five patients (47%) developed a second VsT. Sixty percent had a Khorana risk score of > 3. Thirty-nine patients (41%) were treated with short-term anticoagulation (AC) (< 1 month) (low-molecular-weight heparin, n = 34). Forty-five patients (47%) were treated with long-term AC (> 1 month) (low-molecular-weight heparin, n = 32; 23 were transitioned to an oral anticoagulant). Twenty-two patients (23%) were not treated with AC. Eight patients (8%) had a bleeding complication from AC. Portal vein thrombosis had the shortest overall survival at 3.6 months (range, 2.3-4.8 months). CONCLUSION: In PDAC, VsT can frequently present as an incidental finding on routine abdominal imaging. The most common location is PV, followed by MV and SV. We observed that AC is underutilized in this setting despite a low bleeding complication rate. PV was associated with the least overall survival of the VsT. Future large prospective studies should explore the role of AC and value in this setting.

CHA2DS2-VASc score in the prediction of ischemic bowel disease among patients with atrial fibrillation: Insights from a nationwide cohort.

PURPOSE: This study aimed to evaluate the predictive role of CHA2DS2-VASc score specifically for the development of ischemic bowel disease (IBD) among atrial fibrillation (AF) patients. METHODS: Using a nationwide dataset, an AF cohort was established. The study participants were followed up from the index date until they withdrew from the health insurance system, the occurrence of IBD or until the end of 2011. The hazard ratios (HRs) and 95% confidence intervals (CIs) were examined by Cox models to present the subsequent risk of IBD among AF patients by CHA2DS2-VASc score. The area under the receiver operating characteristic (ROC) curve was used to assess the predictive power of CHA2DS2-VASc score for IBD development among AF patients. RESULTS: The cumulative incidence of IBD was higher for AF patients with a CHA2DS2-VASc score≥2 than those with a CHA2DS2-VASc score<2 by 2.30% (p<0.001) at the end of follow-up. After adjustment for hyperlipidemia, chronic obstructive pulmonary disease, and chronic kidney disease, the AF patients with a CHA2DS2-VASc score≥2 had a 3.35 times higher risk for IBD development compared to those with a CHA2DS2-VASc score<2 [adjusted HR (aHR)=3.35, 95% CI=2.71-4.13]. Among AF patients, the C-statistic of the CHA2DS2-VASc score as a predictor of IBD was 0.56 (95% CI=0.55-0.57). CONCLUSIONS: In conclusion, the study is​ the first to investigate the predictive role of CHA2DS2-VASc score specifically for IBD development among AF patients. However, the predictive power was relatively low; further studies are necessary to confirm our findings.

Mesenteric Infarction: Clinical Outcomes After Restoration of Bowel Continuity.

INTRODUCTION: Patients who have a bowel resection for mesenteric infarction may require parenteral nutrition (PN). This study primarily aimed to determine the aetiological factors for a mesenteric infarction and the effects of restoring bowel continuity on the long-term PN requirements. METHODS: A retrospective review of data on patients treated for mesenteric infarction from 2000 to 2010. RESULTS: A total of 113 patients (61 women, median age 54 years) were identified. Seventy-four (65%) had a superior mesenteric artery thromboembolism, 25 (22%) had a superior mesenteric vein thrombosis, and 4 (3%) had superior mesenteric artery stricture or spasm. Patients younger than 60 years most commonly had a clotting abnormality (n = 23/46, 50%), whereas older patients had a cardiological risk factor (n = 11/17, 65%). All patients with a jejunostomy required long-term PN. Fifty-seven (49%) patients had restoration of bowel continuity (colon brought into circuit). After this, PN was stopped within 1 year in 20 (35%), within 2 years in 29 (50%) patients and within 5 years in 44 (77%) patients (P = 0.001). CONCLUSIONS: A thrombotic tendency is the main etiological factor in most patients younger than 60 years. An anastomosis of the remaining jejunum to the colon can allow PN to be stopped.