Study On The Correlation Between Image Classification Of Collateral Circulation In Portal Hypertension And Nomogram Model Of Hepatic Venous Pressure Gradient

Background and AimsThe serious complications caused by portal hypertension include gastroesophageal variceal bleeding,hepatic encephalopathy and spontaneous peritonitis,etc.Gastroesophageal variceal bleeding is more dangerous,with high incidence,recurrence rate and mortality.Studies have shown that collateral circulation is the early feature of portal hypertension and the basis of esophageal and gastric varices.Enhanced abdominal CT can fully display portal vein structure,such as the collateral circulation,portosystemic shunt,varicose site,portal vein thrombosis,etc.Enhanced abdominal CT/MRI examination should be done before endoscopic treatment for cirrhosis patients who suspected of gastroesophageal variceal bleeding according to consensus.Etiological treatment can delay the progression of the disease to a certain extent.However,some patients who have eliminated the cause of cirrhosis still progress to decompensation,with portal hypertension complications.Hepatic venous pressure gradient(HVPG)is the gold standard for the diagnosis of portal hypertension.When HVPG is greater than 5 mmHg,portal hypertension is considered to exist.When HVPG is greater than 12mmHg,cirrhosis progresses to decompensated stage.The risk of gastroesophageal variceal bleeding,ascites,and death decreased when HVPG decreased by 20%or less than 12mmHg from baseline by using non-selective beta blocker(NSBB).Studies have shown that risk stratification and targeted therapy guided and monitored by HVPG can improve treatment effectiveness,reduce the risk of rebleeding and death,and improve survival.HVPG measurement is usually invasive.Moreover,advanced monitoring equipment and technology are required for the measurement;therefore,its application in clinical practice is limited.The non-invasive prediction model of HVPG has become a research hotspot in recent years.Noninvasive models for portal pressure assessment have been explored for years,which have been conducted based on the assessment of the liver stiffness,computed tomography(CT),radiomics,magnetic resonance imaging(MRI)and serological parameters,etc.These models have good predictive ability when HVPG is less than 10mmHg,but cannot predict whether HVPG is greater than 12mmHg.HVPG 12mmHg is an important inflection point in the treatment of patients with cirrhosis,and there are few prediction models of HVPG 12mmHg in previous studies.In this paper,the characteristics of abdominal enhanced CT images of portal hypertension and hepatic vein pressure gradient model were studied.Our study include there parts as follows.Part 1 Study on the correlation between collateral circulation image classification and clinical features of portal hypertension in cirrhosis Aims:The imaging characteristics of portal hypertension were analyzed and the collateral pathways were classified to provide anatomic basis for the treatment of esophageal and gastric varices.The relationship between collateral circulation and hepatic vein pressure gradient was explored to provide possible factors for the construction of non-invasive model of hepatic vein pressure gradient.Methods:The CT image data and other clinical data were retrospectively analyzed in 258 cases of liver cirrhosis patients with portal hypertension who were hospitalized in Shandong Provincial Hospital from January 2013 to April 2019.Collateral circulation was divided into three categories according to the image characteristics and varicose vein types,and the relationship between the image characteristics and clinical characteristics of portal hypertension and hepatic vein pressure gradient was explored.Results:1.In 258 cirrhotic portal hypertension patients,left gastric varices accounted for 97.3%(251 cases),splenic varices for 92.6%(239 cases).2.The drainage vessels of varicose veins mainly flowed into superior vena cava in 194 cases,among which 156 cases(80.4%)were mainly supplied by left gastric vein,36 cases(18.6%)were left gastric vein+posterior gastric vein or short gastric vein.3.There were statistically significant differences in HVPG among different ascites degrees,Child-Pugh grade and subtype of collateral circulation,with P<0.05.There were significant differences in etiology of cirrhosis,Child-Pugh grade and ascites degree between HVPG>12mmHg and HVPG ≤12mmHg(P<0.05).Conclusions:1.Collateral circulation classified by image characteristics provides anatomic basis for the treatment of esophageal and gastric varices.2.Collateral circulation pathway,ascites degree,Child-Pugh grade and cirrhosis etiology have close relationship with HVPG.These indicators can be included as influencing factors in the further study of HVPG noninvasive model.Part 2 Nomogram Model of Hepatic Venous Pressure Gradient Based on Image Classification of Collateral CirculationAims:To develop and validate a nomogram for an HVPG 12 mm Hg.Assist clinicians to identify patients with decompensated cirrhosis quickly and guide clinical treatment.Methods:A retrospective study was performed to create a nomogram for an HVPG 12 mm Hg in a training cohort that was validated in another cohort.The discriminatory ability and calibration of the nomogram were tested using the C-statistic,area under the receiver operating characteristic curve(AUC)and calibration plots.Results:The nomogram was based on image classification of collateral circulation,the etiology of cirrhosis and Child-Pugh grade.These parameters were significantly associated with an HVPG 12 mm Hg(P<0.05 for both the training and validation cohorts).In the training cohort,the model showed good discrimination(C-statistic,AUC,and R2 of 0.71,0.71 and 0.13,respectively)and good calibration.The model’s cutoff value was 112 and the sensitivity and specificity were 57.1%and 77.6%,respectively.The nomogram model in the validation cohort still showed good discrimination(C-statistic 0.743[95%confidence interval0.61-0.89],AUC 0.743,and R2 0.16)and good calibration.Conclusions:This nomogram is a convenient tool for predicting HVPG 12 mm Hg in patients with cirrhosis and can help clinicians quickly identify patients with decompensated cirrhosis.Part 3 External validation of nomogram model of hepatic venous pressure gradientAims:To test the differential ability and calibration ability of the nomogram model of hepatic venous pressure gradient 12mmHg in external data.Evaluate the clinical application of the model.Methods:1.A total of 31 patients admitted to Jining No.1People’s Hospital from March 2020 to December 2022 due to cirrhosis or cirrhosis related complications were retrospectively collected.Portal vein pressure measurements were completed in all 31 patients,and the clinical data were completed.2.Calculate the score of each patient and the probability of portal pressure was greater than or equal to 12mmHg by using the hepatic vein pressure gradient 12mmHg nomogarm model with R statistical software in 31 outlier verification data.Analyze the AUC value and correction curve of the model in external verification data.Results:The hepatic vein pressure gradient 12mmHg nomogarm model showed good performance in external validation data,with AUC value of 0.966 and 95%CI(0.844-1.00).The corrected curve was superior to the training group and the validation group.Conclusions:The hepatic vein pressure gradient 12mmHg nomogarm model is simple and easy to understand,the parameters are easy to obtain,and the results are highly readable,which has certain guiding significance for clinical work,but the sensitivity and specificity of the model need to be further improved.