|Year : 2017 | Volume
| Issue : 1 | Page : 116-121
Multislice computed tomography in the evaluation of portosystemic collaterals in cirrhotic patients with portal hypertension
Adel M El Wakeel1, Osama L El Abd1, Tarek F Abd Ella1, Heba S Abdel Ghany Ellaban MBBCh 2
1 Department of Radiology, Faculty of Medicine, Menoufia University Shebin El kom, Shebin Elkom, Egypt
2 Radiodiagnosis, National Liver Institute, Menoufia University, Shebin Elkom, Egypt
|Date of Submission||12-Aug-2014|
|Date of Acceptance||07-Sep-2014|
|Date of Web Publication||25-Jul-2017|
Heba S Abdel Ghany Ellaban
Department of Radiodiagnosis, National Liver Institute, Menoufia University, Shobra Bokhom, Quesna, Shebein Elkom, Menoufia Governorate, 32631
Source of Support: None, Conflict of Interest: None
The aim of the study was to investigate the role of computed tomography (CT) and portography in the evaluation of collaterals in cases of portal hypertension.
Liver cirrhosis can result in portal hypertension. Portosystemic collaterals are one of the most severe complications. It may cause massive hemorrhage of the upper gastrointestinal tract. Therefore, prompt evaluation of portosystemic collaterals is imperative.
Patients and methods
This study included 80 patients (63 male and 17 female) aged between 13 and 73 years. It was conducted from May 2012 to February 2014 on outpatients and inpatients of the Hepatology Department, National Liver Institute, Menoufia University. Patients with liver cirrhosis who had findings of portal hypertension on clinical examination underwent multislice CT, and portography images were obtained using the Work Station. Ten patients underwent upper endoscopy for sclerotherapy. We also detected a correlation between the portal vein (PV) diameter and number of collaterals.
Multislice CT and CT portography have been shown to be useful in the evaluation of portosystemic collaterals in cases of portal hypertension. When compared with upper gastrointestinal endoscopy there is upgrading of collaterals. Further, this study detected a significant correlation between the PV diameter and number of collaterals.
Multislice CT has become an important tool for investigation of the liver and can detect potentially problematic varices by detailing the course of these tortuous vessels. This knowledge is important in major operations such as liver transplantation for detection of unexpected varices that can result in significant bleeding. CT portography images can replace the endoscope in the detection of varices.
Keywords: collaterals, computed tomography, portal hypertension
|How to cite this article:|
El Wakeel AM, El Abd OL, Abd Ella TF, Abdel Ghany Ellaban HS. Multislice computed tomography in the evaluation of portosystemic collaterals in cirrhotic patients with portal hypertension. Menoufia Med J 2017;30:116-21
|How to cite this URL:|
El Wakeel AM, El Abd OL, Abd Ella TF, Abdel Ghany Ellaban HS. Multislice computed tomography in the evaluation of portosystemic collaterals in cirrhotic patients with portal hypertension. Menoufia Med J [serial online] 2017 [cited 2019 Sep 21];30:116-21. Available from: http://www.mmj.eg.net/text.asp?2017/30/1/116/211500
| Introduction|| |
Liver cirrhosis can result in portal hypertension. Gastric fundus and/or esophageal varices are one of the most severe complications. It may cause massive hemorrhage of the upper gastrointestinal tract. The clinical management of gastric varices (GVs) is related to their hemodynamics and locations. GVs are classified into three types according to Sarin's classification, which is based on the location of the varices as observed with an endoscope .
Precise and reliable assessment of the portal venous system in patients with hepatic cirrhosis and portal hypertension is essential before liver transplantation, nonsurgical transjugular shunting, or surgical portosystemic shunting. In patients with portal hypertension and a history of gastroesophageal bleeding, it is necessary to determine whether the portal venous system is patent or the portal vein (PV) or its main branches have thrombosis .
Multidetector computed tomography (CT) angiography has become a powerful tool for investigation of the liver. The addition of a portal-phase acquisition with three-dimensional vascular reconstructions can augment the surgeon's perception of potentially problematic varices by detailing the course of these tortuous vessels. This knowledge is important not only for major operations such as liver transplantation but also for more common procedures in which an unexpected varix can result in significant bleeding. With this tool, the radiologist can significantly alter patient care and alert a colleague to potential disaster .
The current study aimed to discuss the role of multislice CT angiography in the evaluation of portosystemic collaterals in case of portal hypertension.
| Patients and Methods|| |
The study was carried out at the Department of Radiology, National Liver Institute, Menoufia University, from May 2012 to February 2014. It is a cross-sectional study including 80 patients (63 male and 17 female) aged between 13 and 73 years from the outpatient clinic and from among inpatients of the Hepatology Department, National Liver Institute.
Patients with advanced liver disease (Child–Pugh's C score or active gastrointestinal bleeding, encephalopathy, or ascites) and those with glomerular infiltration not less than 90 ml/min were eligible for inclusion in the study.
Patients with renal impairment were excluded.
Consent was taken from patients or their relatives before performing CT and they had the right to refuse at any time. The study was approved by the Research Ethics Committee of the National Liver Institute and the Research Ethics Committee of the Faculty of Medicine, Menoufia University.
All individuals were subjected to clinical assessment including full history taking and clinical examination, laboratory investigation, and triphasic multislice CT scanning, and upper endoscopy for 10 patients for sclerotherapy.
Multislice triphasic computed tomography scanning
CT was performed with a Siemens Somatome Definition Scanner (Siemens Aktiengesellschaft, Wittelsbacherplatz 2 80333, Munich, Germany) (20 detectors) in the National Liver Institute.
- Patients had to fast for 6 h before the scan.
- No oral contrast was used.
- Glomerular filtration rate had to be at least 90 ml/min.
- The patients were subjected to vigorous oral hydration.
- An intravenous cannula was introduced through the antecubital vein.
- The patient was made to lie supine. Scanning started from the lung bases down to the symphysis pubis in all phases.
- One scout was acquired in anteroposterior view. The examination was planned on this scout from the top of the right diaphragmatic cupola (hepatic dome) until the symphysis pubis in the precontrast and postcontrast sequences.
- The precontrast series was taken at 10 mm thickness, at a slice pitch of 1.5, a gantry rotation period of 0.6 s, and a table speed of 15 mm/rotation. The X-ray tube voltage was 120 kV, and current was 240–280 mA.
- Images using a multidetector CT scanner were taken in the arterial, portovenous, and delayed phases for all patients. All patients received 120 ml of nonionic material (Ultravist 300, Berlex–US) introduced at an infusion rate of 4.0 ml/s intravenous using a single power injector.
- Arterial dominant-phase images were acquired at 18 s (collimation 1.25 mm; pitch 0.6; voltage 120 kVp; current 240–280 mA).
- Portal dominant-phase images were acquired at 60 s (collimation 2.5 mm; pitch 0.6; voltage 120 kVp; current 240–280 mA).
- Delayed-phase images were also taken of the entire liver at 200 s (collimation 2.5 mm; pitch 0.6; voltage 120 kVp; current 240–280 mA).
All acquired data were reconstructed with a standard algorithm, and postprocessing was performed on a commercially available workstation (Syngo Work Station, Siemens, USA) equipped with software that allowed generation of three-dimensional images.
We use the macrophage inflammatory protein technique and three-dimensional image reconstruction for portography images, which is helpful for the detection of details and orientation of vessels.
The following features were recorded.
The portography images and portal-phase imageswere analyzed for PV patency and diameter, for splenic vein diameter, for the presence of collaterals, their sites, and grading, and for signs of manifestation of portal hypertension such as splenomegaly and ascites.
The dilated varices are classified into the following: varices draining into the superior vena cava (SVC), such as esophageal, paraesophageal, and GVs; and varices draining into the inferior vena cava (IVC), such as splenic, perisplenic, lienorenal, and recanalized paraumbilical vein. The dilated veins present within and outside the wall of the lower esophagus are termed esophageal and paraesophageal, respectively.
The dilated veins within the submucosal layer of the stomach are the gastric submucosal varices, whereas those within the adventitial layer at the exterior wall of the stomach are termed gastric adventitial varices. The dilated veins surrounding the stomach are termed the perigastric collaterals. The dilated veins along the splenic hilum are termed splenic varices, whereas veins surrounding the spleen are termed perisplenic varices. The recanalized paraumbilical vein is the dilated vein at the site of the ligmentum teres and falciform ligament. On cross-section it appears circular or tubular  [Figure 1].
|Figure 1: Diagram showing sites of portal–systemic collateral circulation.|
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Varices involving the splenic, lienorenal, and recanalized paraumbilical vein were defined as vascular if their diameter was greater than 3 mm. For the esophageal, paraesophageal, and gastric collaterals the size criterion was 2 mm in diameter. Grading of varices by measuring the largest visible varix, according to the diameter of the largest varix and the number of varices on cross-section images, was based on a five-point scale. If there were more than four dilated vessels on the second cross-section the varices were graded one step higher  [Table 1].
|Table 1 Computed tomography grading of collaterals on a five-point scale|
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All images, including three-dimensional reconstructed models, were sent to Syngo Work Station in the National Liver Institute for interactive analysis.
The data were collected, coded, and processed using statistical software (SPSS; SPSS Inc., Chicago, Illinois, USA) under professional XP and statistical tests were applied.
Results were collected, tabulated, and statistically analyzed with an IBM personal computer and statistical package SPSS (version 20). Two types of statistics were determined.
- Descriptive statistics: In the form of percentage ofcollaterals.
- P value: Showing the correlation between the PV diameter and the number of collaterals, splenic vein diameter, and middle hepatic vein.
- P values less than 0.05 indicated significant difference.
- P values greater than 0.05 indicated nonsignificant difference.
- P values less than 0.001 indicated highly significant difference.
| Results|| |
The gastric and perigastric collaterals were the most common type of collaterals draining into the SVC, being present in 76.25% of cases [Table 2].
|Table 2 Distribution of the studied patients regarding draining of their collaterals|
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The splenic hilum and splenic collaterals were the most common type of collaterals draining into the IVC, being present in 56.25% of cases [Table 3].
|Table 3 Distribution of the studied patients regarding their collaterals draining into the inferior vena cava|
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The esophageal collaterals initially seen on endoscopy were upgraded on CT [Table 4].
|Table 4 Distribution of the studied patients regarding their grading by computed tomography and endoscopy|
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There was significant correlation between the PV diameter and number of collaterals (P = 0.001). The increase in collateral number was associated with a decrease in PV diameter [Table 5].
|Table 5 Correlation between portal vein diameter and number of collaterals, splenic vein diameter, and middle hepatic vein diameter|
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There was a highly significant correlation between the PV diameter and splenic vein diameter and the middle hepatic vein diameter (P < 0.001). The increase in PV diameter was associated with an increase in splenic vein diameter and decrease in middle hepatic vein diameter [Figure 2],[Figure 3],[Figure 4],[Figure 5].
|Figure 2: Descriptive statistics showing distribution of the studied patients with respect to collaterals draining into the superior vena cava.|
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|Figure 3: Descriptive statistics showing distribution of the studied patients with respect to collaterals draining into the inferior vena cava.|
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|Figure 4: Volume rendering technique image showing dilated lienorenal and splenic collaterals (arrow). (b) Computed tomography (CT) portography showing dilated lienorenal collaterals(arrow). (c) CT coronal image showing HCC infiltrating the portal vein (arrow).|
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|Figure 5: a) Computed tomography (CT) portography image showing the dilated perigatric collaterals (arrow). (b) CT coronal image showing portal vein thrombosis recanalized by collaterals (arrow).|
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| Discussion|| |
The portal system consists of all veins that carry blood from the abdominal part of the alimentary tract except the lower rectum and anal canal. It also receives drainage from the pancreas, spleen, and gall bladder. Multidetector CT portal venography can determine the extent and location of portosystemic collaterals in patients with portal hypertension .
In cirrhotic patients with portal hypertension some blood in the portal venous system may reverse direction and pass through the portosystemic anastomoses in the systemic venous system. As a result, a variety of major hepatofugal collateral pathways can develop in patients with portal hypertension. For many years, angiography was considered the standard for detecting collateral vessels .
Multidetector computed tomography portal venography can display esophageal varices, GVs, and related bypass circuits, especially because of the thinner slice and better spatial resolution of the CT scanner .
The purpose of our study was to assess the role of multidetector CT and portography in the evaluation of collaterals in cases of portal hypertension. It was found that multislice CT is very important for the detection of collateral sites and draining routes and for grading.
In agreement with our study, Wang et al.  reported that CT-MIP venography could be an effective, noninvasive method for detecting the compensatory circulation resulting from decompensated portal hypertension.
However, according to Agrawal et al  CT is second line to ultrasonography with color Doppler in patients with known portal hypertension, not primary. However, in our study we consider CT as the first line for demonstration of all types of collaterals.
Our study showed that the most common type of collaterals draining into the SVC is the perigastric type as we detected esophageal and paraesophageal collaterals in 70% of cases, and perigastric in 76.25%.
These results are in agreement with those of Chen et al. , who reported that the most common type is the perigastric type, as gastric fundus varices were seen in 32 (97.0%) cases and esophageal varices in 27 (81.8%). Wang et al.  also demonstrated GVs in 97% of cases and esophageal varices in 83%. Agrawal et al.  detected collaterals along the left gastric vein in 13% of cases and esophageal collaterals in 6% of cases. This is because all these cases had posthepatitic cirrhosis leading to portal hypertension.
In contrast, Henseler et al.  detected esophageal collaterals in 90% of cases and gastric in 34% of cases. This is because, in that study, the cause was postalcoholic cirrhosis and autoimmune cirrhosis.
In our study the most common type of collateral draining into the IVC was the splenic collateral, seen in 56.25% of patients; the lienorenal was seen in 28.75% and the recanalized paraumbilical vein in 10%; no intrahepatic collaterals were detected. These results are in agreement with those of Wang et al. , who reported collaterals originating from the splenic vein in 67% and from the paraumbilical vein in 17% of cases. This is due to similarity in the diseases leading to portal hypertension.
These results are in disagreement with those of Henseler et al. , who detected collaterals in the splenic hilum in 7%, recanalized paraumbilical vein in 24%, and mesenteric collaterals in 2%. This is due to changes in the causes of portal hypertension.
When the result of 10 patients who underwent upper endoscopy and abdominal triphasic CT to detect esophageal varices grading were compared, upgrading of collaterals was found on CT.
This is in agreement with the results of Yu et al. , who reported that endoscopic undergrading of the high-risk esophageal group will lead to overestimation of CT sensitivity for low-risk esophageal varices. The results are also in agreement with those of Kim et al. , who reported that careful evaluation of high-risk esophageal varices on a liver multiple detector computed tomography examination may be useful to avoid performing endoscopy. CT can be used as a single noninvasive surveillance tool for both esophageal varices and recurrent hepatocellular carcinoma.
Similarly, Perri et al.  reported high sensitivity of CT for assessment of high-risk GVs; in addition, GVs were detected in many patients in whom GVs were not detected on endoscopy. Mifune et al.  also reported that, in relation to endoscopy, MDCT is useful for prediction of high-risk esophageal varices.
In our study, significant correlation was found between the PV diameter and number of collaterals (P = 0.001). Increase in the number of collaterals is associated with a decrease in PV diameter due to conversion of blood from the PV to the collaterals.
There was also a highly significant correlation between the PV diameter and splenic vein diameter (P < 0.001). The increase in PV diameter was associated with an increase in splenic vein diameter and middle hepatic vein diameter (P < 0.001). The increase in PV diameter was associated with a decrease in hepatic vein diameter.
| Conclusion|| |
It can be concluded that multislice CT is an important noninvasive imaging modality in the diagnosis of collaterals in cases of portal hypertension. It was also found that CT portography can replace endoscopy in the detection of varices.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]