Left-Sided Portal Hypertension - SASSiT

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1144 Dig Dis Sci (2007) 52:1141–1149 Table 2 The origin of acute gastrointestinal bleeding in patients with left-sided portal hypertension (LSPH) a For prospective studies. b Review of the literature. c Prospective studies. Number of Acute GI Mean patients with bleeding due Esophageal Gastric Combined follow-up Reference LSPH to varices varices varices varices time (mo) a 78 2 2 20 Moosa et al., 73 51 4 38 31 1985 [16] b Warshaw 8 2 8 et al., 1987 [45] Bradley 11 2 6 [44] c et al., 1987 Evans et al., 12 10 10 1990 [5] Bernades 22 1 100 [10] c et al., 1992 Sakorafas 34 6 12 et al., 2000 [7] Heider et al., 53 2 11 30 2004 [23] Köklü et al., 24 6 21 2005 [22] c most patients with gastric varices have thickened mucosal folds in the fundus of the stomach, the abnormality is rarely specific for the disorder [49]. These findings can be misinterpreted as gastric carcinoma, lymphoma, multiple polyps, or Menetrier’s disease [50, 51]. The reported accuracy of barium contrast studies in patients with proved gastric varices has ranged from 14% to 74% [52, 53]. Currently, bariumcontrast examinations are not frequently used because newer diagnostic techniques are preferred. Upper gastrointestinal endoscopy can be used to detect the presence of gastric varices. The endoscopic appearance of gastric varices varies from clear-cut variceal veins to irregularities or nodularities in the rugae [54]. If isolated gastric varices are seen on endoscopy, LSPH should be considered, and advanced diagnostic studies should be performed to clarify the diagnosis. As endoscopists have become more competent, the accuracy of visualizing gastric varices has increased. In an early series, less than half of the patients with gastric varices found on splenoportography were diagnosed correctly by endoscopy [49]. In a more recent study, gastric varices have been accurately diagnosed and localized in nearly 90% of cases [55]. A careful examination should be made to find gastric varices in every patient with gastrointestinal bleeding of obscure origin, particularly if it is accompanied by splenomegaly. Two techniques of angiography are available for diagnosing LSPH. Splenoportography was popularized by Leger in 1951 as a method to visualize the portal venous system, but that procedure is rarely used today because it is invasive and has potential morbidity, particularly in patients with portal hypertension [11]. Arteriography is the preferred method for diagnosis and is a safer and more controlled technique in patients with a prolonged prothrombin coagulation time and elevated portal or systemic pressures [56]. Angiography outlines the location of obstruction and the route of decompression. Catheterization of the celiac axis provides access to surrounding arterial structures, including abnormal hepatic and pancreatic neoplastic vasculature. Subsequently, venous phase studies can be performed [16]. The portal system is generally shown clearly; however, arterographic studies often fail to demonstrate collateral veins that can be seen on splenoportography [1]. Venous phase angiography accurately shows both the location of the splenic vein obstruction and collateral flow. The diagnosis of SVT is confirmed on angiography when the splenic vein fails to opacify on the venous phase of the splenic artery injecton. Often venous collaterals in the splenic hilum and dilated gastroepiploic and short gastric veins are also seen [26]. Intra-arterial digital substraction angiography (DSA) reliably shows the portal venous system, collateral circulation, shunt location and postoperative changes. The major advantage of intra-arterial DSA is the smaller amount of contrast medium injected, so that local and systemic side effects are rare [57]. Other well-known advantages of intra-arterial DSA are quicker execution, less injury to arteries offered by smaller-caliber catheters, and low cost. The major disadvantage of intra-arterial DSA is that the field size of the intensifier is limited to 6–9 in. Springer
Dig Dis Sci (2007) 52:1141–1149 1145 Ultrasonography (US) is often used as a preliminary, noninvasive test for LSPH. US is the least invasive of all available tests. The accuracy of US in the diagnosis of SVT, versus in the diagnosis of portal vein thrombosis, may be limited by the size and location of the splenic vein [2]. Studies comparing US with angiography and arterial portography in evaluating portal vein patency have demonstrated US to be relatively accurate, with a sensitivity and specificity of 93% and 83%, respectively [58, 59]. However, US may be less accurate in assessing splenic vein patency because of the anatomic location of the splenic vein. In one study, by Alpern et al.,the direction of flow in the splenic vein was correctly determined in 9 of 16 patients undergoing duplex US. The study found that, in some patients with SVT, imaging of collateral vessels near the splenic hilum could be misinterpreted as the splenic vein, and that operator experience is paramount [59]. Generally, Doppler ultrasonography is the first imaging technique used in patients with elevated portal pressure and is accurate in the assessment of the portal venous system [60, 61]. Noninvasive and relatively inexpensive evaluation can be achieved with color Doppler US, which shows the portal vein and provides additional information about velocity and direction of flow. However, Doppler US is observerdependent and may be unsuccessful when the acoustic window is not available for evaluation of the whole portal venous system [60–62]. In addition, US does not show the overall anatomic structure that interests the clinician. Therefore, in patients who are potential candidates for surgery, a more exact diagnostic method that covers the whole portal venous system is required, such as magnetic resonance (MR) angiography [61]. Recently, endoscopic ultrasound (EUS) has been used to assess the portal vasculature. This method appears to be a more accurate test than transabdominal US for evaluating patency of the splenic vein in some reports [63, 64]. As one of the most sensitive imaging methods for studying the pancreas, EUS has resulted in an improved ability to diagnose pancreatic mass lesions and to assess vascular involvement in pancreatic malignancies [63, 65]. EUS is superior to both US and computerized tomography (CT) in diagnosing small pancreatic lesions and assessing vascular invasion, with an accuracy of 94% and 87%, respectively [63, 65]. EUS is also useful in diagnosing chronic pancreatitis, with a sensitivity, specificity, and accuracy of 80%, 86%, and 84%, respectively [66]. It should be considered when other diagnostic methods have failed to confirm SVT as a cause of bleeding gastric or gastroesophageal varices [66]. It should also be considered in cases of SVT occurring without a history of chronic pancreatitis, so that pancreatic carcinoma can be investigated as a potential cause of SVT. Because SVT is generally associated with pancreatic pathology, EUS may be an ideal diagnostic method to evaluate the splenic vasculature and the pancreatic parenchyma. EUS has also been shown to be useful and highly sensitive in detecting paraesophageal and gastric varices [67–69, 90–92]. In a study comparing EUS and CT, the former was found to be more sensitive in detecting paraesophageal varices [67]. It has also been reported that EUS is more sensitive than conventional endoscopy in detecting gastric varices [70, 71]. Contrast-enhanced CT portography can demonstrate the portal venous system in a short time [72–75]. However, it uses ionizing radiation and requires a large amount of iodinated contrast material. Unless multidetector CT is used, CT portography may also suffer from limited longitudinal coverage because usually CT provides only axial scan mode [76]. Magnetic resonance imaging (MRI) is an increasingly valuable tool for the assessment of the portal venous system and splenic vasculature. MR angiography with gadopentetate dimeglumine has been shown to be a very promising noninvasive method for the assessment of the portal venous system [77–82]. MR angiography appears to be a more accurate diagnostic procedure than Doppler sonography and CT [60, 72, 83, 84]. In one study, the splenic vein was not evaluated optimally due to gastrointestinal gas interfering with Doppler sonography in four patients; however, on MR portograms the splenic vein was shown to be normal in three patients and partially thrombosed in one [85]. Contrast-enhanced MR angiography has also been increasingly used in patients with portal hypertension for the diagnosis of patency or thrombosis of the portal venous system [85–87]. It should be mentioned that thrombosis in the proximal splenic vein may not be shown even by the diagnostic techniques discussed here, and so sometimes it can be confirmed only intraoperatively [17, 26]. Treatment LSPH is one of the rare curable syndromes causing portal hypertension [88]. To form a consensus on the treatment of patients with LSPH, the underlying diseases, the presence and severity of symptoms, and the general condition of the patients should be considered. Bleeding (variceal or nonvariceal) is the most common manifestation of LSPH [5]. Variceal bleeding may be severe and life-threatening and can originate from esophageal, gastric, or even colonic varices [27, 56, 89]. Management should be directed at the splenic side of the portal circulation because pressure is increased only on that side [5]. Proximal portal decompressive procedures (any sort of portosystemic shunt) are hazardous and do not address the disease process, since these patients have normal portal pressures and generally normal hepatic function [5]. Conservative therapy including balloon tamponade, sclerotherapy, vasoconstrictive therapy, and band ligation may be performed for bleeding control. Springer
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Left-Sided Portal Hypertension - SASSiT

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