The Diagnostic Value Of CT In The Diagnosis Of Small Intestine Necrosis Caused By Acute Superior Mesenteric Venous Thrombosis

Objective:Summarize the computed tomography(CT)signs of small intestine necrosis caused by acute superior mesenteric venous thrombosis(SMVT)and to evaluate the diagnostic value of CT in the diagnosis of small intestine necrosis caused by SMVT.Materials and Methods:We searched for acute abdomen patients,who sought diagnosis and treatment at Tianjin Medical University General Hospital between October 2014 and August 2016 and were diagnosed clinically and/or by CT examination as SMVT;we took patients who were diagnosed as SMVT by review after surgical or non-surgical treatment as the study subjects.There were 40 males and 17 females,and their ages were between 14 and 88(mean,51.8±16.7)years old.At the time of seeking treatment,all patients had abdominal pain accompanied by sudden exacerbation history,they were experiencing various degrees of nausea,vomiting,fever,and increased white blood cells and D-dimers,and the onset time was8 h~15 d,with a median time of 6 d.Then,the SMVT patients were divided into an intestinal necrosis group and a reversible intestinal ischemia group according to whether the necrotic small intestine was surgically removed.Retrospective analysis of the plain and enhanced CT scan data of acute SMVT patients who were diagnosed via effective surgical treatment and thrombolytic therapy.According to the presence or absence of small intestine necrosis,57 cases of enrolled patients were divided into a reversible small intestine ischemia group(n=36)and an small intestine necrosis group(n=21).The patients were classified into three types according to venous thrombosis range,and the CT signs of small intestine ischemia were scored.The difference in the classification of the venous thrombosis between the groups was analyzed using Spearman's rank correlation analysis.The difference in clinical data and the scores of CT signs were first analyzed via univariate analysis,and multivariate logistic regression analysis was then used to determine the characteristic manifestation and diagnostic value of small intestine necrosis.Results:Fifty-seven patients were confirmed to have acute SMVT by follow up review after surgical pathology examination and nonsurgical treatment.There were36 cases of reversible intestinal ischemia,whose clinical symptoms and CT signs improved,with a follow-up time of 6m~20m.The small intestine necrosis group had21 cases;5 cases were confirmed by surgical resection,and the remaining 16 small intestine necrosis patients underwent thrombolytic therapy,which was ineffective,with the presence of thrombus and repeated intestinal obstruction lasting for over one month.Ten cases were eventually confirmed by surgical resection of pathogenic intestine,and the remaining 6 cases were reviewed by CT after follow up for 2-4months,confirming that the treatment was ineffective.In this group,three patients died3,4 and 8 months after disease onset.For patients who underwent multiple CT examinations after disease onset,the principles for the selection of the CT data were as follows:for the CT data of patients who underwent thrombolytic treatment,the last CT examination data before the thrombolytic treatment were selected.For the evaluation of the efficacy of thrombolytic treatment,the postoperative CT data of the last review before being discharged were selected.For patients who underwent surgical treatment,the last preoperative CT data were selected.SMVT range can be used as an independent predictor for small intestine necrosis(r_s=0.087,P=0.000).Cirrhosis(P=0.001),Thrombophilia(P=0.002),the lack of collateral circulation(P=0.000),the reduction of the reinforcement degree of the intestinal wall(P=0.000),and a high density thrombus shown on plain CT(P=0.000)are highly correlated with small intestinal necrosis.Conclusion:CT can accurately predict intestinal necrosis caused by acute SMVT.In this study,we classified SMVT according to its location and range.By combining clinical data and surgical results,we analyzed the correlation between thrombosis range and the CT signs of intestinal ischemia and the clinical occurrence of intestinal necrosis and assessed the diagnostic capability of CT in predicting the irreversible ischemia of the intestinal wall.This study suggests that acute SMVT has a wide range and simultaneously involves the proximal,distal and end branches of the SMV,which can be used as an independent predictor for small intestine necrosis.Patients with cirrhosis,thrombophilia,less collateral circulation,a decline in the degree of intestinal wall reinforcement,high-density thrombus on plain scan CT and other signs are highly correlated with the occurrence of small intestine necrosis.When the thrombosis range is limited to the main trunk of the SMV and/or the secondary branches of the mesenteric vein,small intestine ischemia can recover after anticoagulation treatment.