Dig Dis 1992; 10(suppl I ): 94-102

Medizinische Universitätsklinik. Freiburg, FRG

KeyWords Transjugular intrahepatic portosystemic stent-shunt Portal hypertension Variceal bleeding Hepatic encephalopathy Cirrhosis

Interventional T reatment of Portal Hypertension

Abstract

For many years now, percutaneous transhepatic and transju­ gular approaches to the portal vein have been applied by gas­ troenterologists and radiologists for diagnosis and therapy. In patients with variceal bleeding these techniques were used to obliterate the varices, and have provided the knowledge for further developments, such as the creation of an intrahepatic portosystemic shunt by balloon dilatation of the needle tract between the portal vein and a hepatic vein. The recent devel­ opment of expandable vascular stents has led to improve­ ments in the efficiency and long-term patency of interven­ tional shunts, and justified their clinical application. The rationales for this new approach to the treatment of portal hypertension are its relative safety, even in Child C patients, and the disabilities such as rebleeding or aggravation of hepatic encephalopathy of other current treatments. Since the first clinical application of the transjugular intrahepatic porto­ systemic stent-shunt in January 1988, the technique has been improved considerably, and the frequency of its application is increasing rapidly. This article attempts to summarize the cur­ rent state of knowledge of this interventional technique, which will soon have its place among the various methods of treating portal hypertension.

Introduction

Percutaneous transhepatic [1-8] or trans­ jugular [9-11] catheterization of the portal vein has been used for many years to treat variceal bleeding by obliterating the varices.

Clinical studies indicate that percutaneous obliteration of varices may stop the acute bleeding but docs not prevent recurrence. Thus, it can be assumed that varices recur as long as the elevated portal pressure persists. This led to revival of decompressing proce-

Prof. Dr. M. Rosslc Medizinisch: Universitätsklinik Hugsteuerstrasse 55 D-W-7800 Freiburg (FRG)

© IM2 S. Karger AG. Basel 0257-2753/92/ 0I07-0094S2.75/0

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Marlin Russie Klaus Haag

omitting the percutaneous transhepatic tar­ geting. using ultrasound guidance instead [28], With this improved technique more than 50 patients have been treated since June 1990. The experiences of this present study and the results of other studies published so far arc summarized in this article.

Methods Technique of TIPS For fluoroscopic targeting, the portal bifurcation is located by sagittal sonography and its position is marked on the skin. Under mild sedation (midazolam) and anesthesia (pethidin). the right hepatic vein is then catheterized transjugularlv and a modified Ross needle is introduced through this catheter (Cook Transjugular Biopsy Kit). The connection between the hepatic vein and the intrahepatie right or left branch of the portal vein is created by advancing the needle transhepatically. The path of the needle is controlled fluoroscopically as it advances towards the target. After successful puncture of the portal vein, a guide wire (Amplatz super stiff. 0.035) is introduced through the needle, the catheter is advanced into the portal vein and the nee­ dle is removed. The needle tract is then dilated by bal­ loon catheter (balloon size: 7 mm) and an expandable stent is introduced and dilated to a diameter of 810 mm. 1,000 U of heparin are injected intravenously at the time of stent placement. Finally, the jugular access sheath is removed and the patient is observed intensively for 12 h unless complications occurred. Pie- and Postoperative Management Upper endoscopy w-as performed preoperatively to determine the status of the varices and to exclude the presence of ulcers which could have resulted from pre­ vious sclerotherapy and which arc a potential source of postoperative gastrointestinal bleeding. In the pres­ ence of deep ulcers with stigmata of bleeding (Forrest 1 and 2). the procedure was postponed until improve­ ment. Sonography and Duplex sonography are re­ quired to exclude hepatocellular carcinoma and to assure patency of the portal vein, hepatic artery', and the hepatic veins. Paracentesis is indicated in patients with gross ascites. The more cranial and sagittal posi­ tion of the liver, caused by gross ascites, makes the transjugular puncture of the portal vein more difficult. Moreover, in cases of liver capsule perforation and intra-abdominal bleeding, spontaneous coagulation

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dures, and the development of interventional techniques to establish an intrahepatie porto­ systemic shunt. As early as 1967, Hanafee and Weier [12] described the transjugular approach to the portal vein and. in 1969 and 1971, Rösch et al. [13, 14] published their studies with trans­ jugular intrahepatie shunts in pigs and dogs by the introduction of Teflon- or siliconecoated tubes between the portal vein and the inferior vena cava. With the availability of expandable balloon catheters. Buergener and Gutierrer [15-17] created intraparenchymal channels by balloon dilatation of the liver tis­ sue in animals. Using this technique. Colapinto et al. [18. 19] performed a clinical study in 1982. The results of this study [20] were disappointing, because most patients died early from recurrent bleedings, demonstrating that balloon dilatation of the tissue tract per sc was not sufficient to maintain effective por­ tal decompression and portosystemic shunt­ ing. This problem was overcome by the devel­ opment of expandable vascular stents which, introduced into the liver parenchyma be­ tween a main branch of the portal vein and a hepatic vein, created a permanent channel through the liver tissue. Animal studies by Palmaz et al. [21, 22] in 1985 and 1986. and by Rösch et al. [23] in 1987 demonstrated the efficiency and long-term patency of transjugu­ lar intrahepatie portosystemic stent-shunts (TIPS). Based on these experiences, we performed a pilot study in 1988 and 1989 in 12 patients with recurrent variceal hemorrhage [24. 25]. The original technique consisted of a percuta­ neous transhepatic catheterization of the por­ tal vein and placement of a target near the portal bifurcation, and the transjugular punc­ ture of the portal vein with the aid of the tar­ get. and the creation of the intrahepatie shunt [26, 27], During the course of the study the technique was improved considerably by

Indications and Contraindications In the first pilot study described [24. 25], TIPS was performed in patients with recurrent variceal bleeding who had been excluded from operative treatment and had had more than 6 sessions of sclerotherapy. With technical improvement the indications were extended and the treatment is now offered to all patients with recurrent variceal bleedings independent of age, prior sclerotherapy and Child stage [29]. Recently, a small study was published in which TIPS was used as an adjuvant treatment in patients with portal hyperten­ sion awaiting liver transplantation [30], Unfortunate­ ly. the authors described neither the effects of TIPS on the transplantation procedure itself, nor on pre- or posttransplantation survival. TIPS is clearly contraindicated in patients with acute liver failure and with chronic severe liver insuffi­ ciency with overt hepatic encephalopathy stages 3 or 4 and severe jaundice. Limited arterial perfusion of the liver (e.g. stenosis of the truncus celiacus or the hepatic artery) may lead to liver failure postoperatively and was excluded by Duplex sonography. Severe coagu­ lopathy is not a contraindication in patients with vari­ ceal bleedings because rebleeding is fatal, justifying the

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higher operative risk. Technically, thrombosis of the right internal jugular vein and the portal vein exclude the establishment of TIPS.

Results

Success Rate Technical success was achieved in more than 90% of the patients [29], This is in accor­ dance with the success rates reported for transjugular variceal obliteration [11], Inabil­ ity to puncture the portal vein was responsible for the treatment failures. Treatment-Related Complications Early Mortality. The first technique de­ scribed [26, 27] using a percutaneous transhepatic access to the portal vein was compli­ cated by 2 treatment-related deaths due to severe intra-abdominal bleedings from the site of the percutaneous transhepatic punc­ ture. Another patient died within a few hours from intra-abdominal bleeding emerging from the portal bifurcation in which the stent had been placed and which was located extrahepaticaliy [unpubl. data]. Therefore, punc­ ture and stent placement very close to or at the portal bifurcation has to be strictly avoided. In addition to these severe complica­ tions causing death. 10% of the patients had minor complications consisting of bleedings into the bile duct system, the liver capsule or abdominal cavity [29], These bleedings were, in part, due to postoperative heparinization, and ceased after withdrawal of heparin treat­ ment in all patients. They did not lead to rele­ vant morbidity. Technical Complications. Technical com­ plications are rare and depend on the type of stent used. In a series of 50 patients treated in our hospital, dislocation of 1 Palrnaz stent and 1 Wall stent occurred. The dislocated Palmaz stent could be disposed in the periphery Interventional Treatment of Portal Hypertension

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may be impaired by surrounding ascitic fluid. The presence and grade of hepatic encephalopathy were assessed by psychometric testing and clinical examina­ tion. All patients were treated with lactulose, and TIPS was postponed in cases of overt encephalopathy. Four packs of erythrocyte concentrates and fresh frozen plasma have to be available on the ward and. in patients with severe thrombocytopenia ( < 40,000). preoperative substitution of thrombocytes may be re­ quired. Special care is indicated for patients with reduced renal function which may deteriorate with the application of high amounts of contrast medium. Pre­ operative and intraoperative expansion of the plasma volume, intraoperative application of furosemide and postoperative application of dopamine may help to prevent additional kidney damage. Postoperatively. monitoring of blood pressure and heart rate during the first 12 h are mandatory to detect intra-abdominal bleeding in the early postoperative phase. Thereafter, severe bleeding complications arc not to be expected unless heparin is given in an over­ dose. Unless severe coagulopathy exists, 10.00020,000 U of heparin per 24 h were administered intra­ venously during the first postoperative week, followed by prophylactic subcutaneous treatment for 1 month to prevent shunt thrombosis. Acetylsalicylic acid is not recommended in these patients because of the side effects on gastric mucosa and renal function.

Late Mortality Long-term follow-up showed 1- and 2-year survivals of 58 and 50%. respectively [32], The results of this pilot study include 2 treat­ ment-related deaths due to the percutaneous transhepatic approach to the portal vein. An improvement of the mortality rate can be expected with increasing experience and om­ ission of the percutaneous transhepatic ap­ proach. Thus, in our present study, 6-month mortality amounts to only 4% (2 patients) [29]. Deaths were due to heart failure in an 84-year-old patient, and to sepsis in a 48-yearold emergency patient. Rebleedings and Stenosis The rate of rebleedings amounted to about 10% [29], Rebleedings were due to early thrombosis of the shunt (2 patients) or steno­ sis of the hepatic vein (3 patients). Stenoses of the outflow of the shunt (hepatic vein) were probably due to proliferation of the intima which may be caused by the high velocity of the blood stream. Two patients in the pilot study [32] developed shunt stenosis due to infiltration of hepatocellular carcinoma. Another 20% of the patients developed steno­ sis of the shunt which was diagnosed by rou­ tine Duplex sonography indicating transjugu­ lar réévaluation [33], All patients, except

those with hepatocellular carcinoma, were successfully treated by redilatation, and im­ plantation of an additional stent if necessary. Hepatic Encephalopathy and Liver Function The effect of TIPS on hepatic encephalop­ athy has been described in 2 studies [31, 32], Two (3%) out of a total of 60 patients treated in our hospital developed several episodes of hepatic encephalopathy stages 3 and 4. which responded to medical treatment. Mild hepatic encephalopathy, assessed by psychometric testing, did not deteriorate significantly after the shunt and was detected in 10% of the patients [29]. With the exception of 2 pa­ tients. who showed significant but transient deterioration of bilirubin concentrations, pro­ thrombin time and concentrations of biliru­ bin. cholinesterase and albumin were not changed by the shunt. In contrast, the concen­ tration of ammonia increased moderately in half of the patients [34], Hemodynamic Effects o f TIPS As described recently [24. 29. 32], with a stent diameter of 8-10 mm, TIPS reduces portal pressure to about 50% of the preexist­ ing value. In a majority of patients, the portal pressure was reduced to a gradient of less than 12 mm Hg. In patients with portal pressure gradients above 15 mm Hg and/or significant intrahepatic portal perfusion and variceal opacification, careful angiographic evaluation is required to detect the cause of shunt insuffi­ ciency. This may be due to either a too narrow or too short stent-shunt. The first possibility can be resolved by expanding the stent to a diameter of 10 mm, which almost always leads to a reduction in portal pressure to below 15 mm Hg. Therefore, in patients in whom dilation was performed using a 10-mm balloon catheter the latter condition can be assumed, and angiography usually discloses

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of the hepatic vein, and the Wail stent, which was displaced into the right atrium, could be removed via the jugular vein. Dislocations of Paimaz stents were also reported in 2 other patients treated in Metz [unpubl. data] and in Miami [31]. Another complication which oc­ curred in 2 of our patients was the loss of cath­ eter material adherent to the Paimaz stent. The pieces of catheter material. 6 and 10 cm in length, could be removed after pinching them off using laparoscopic scissors. These complications, also, did not cause relevant morbidity of the patients.

Fig. 1. Transjugular portography after creation of TIPS, a Insufficient shunting after implantation of 2 Palmaz stents due to disconnection of the shunt and the hepatic vein (arrow). Note maintenance of portal liver perfusion and variccal opacification, b Effective shunting without opacification of the varices after placement of an additional Palmaz stent. The arrow indicates the indentation caused by the wall of the hepatic vein which caused obstruction.

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ble 1). Changes towards the preoperativc he­ modynamic pattern indicate stenosis or oc­ clusion of the shunt.

Discussion

Whether or not a new therapy can be rec­ ommended depends on its impact on survival and life quality. Current treatments, e.g. med­ ical treatment, sclerotherapy or surgical shunts, do not prolong life significantly, and are biased by high rates of either rebleeding or hepatic encephalopathy [35]. This justifies continuing the search for improvements in treatment with the aim of reducing mortality, rebleeeding and incidence of hepatic encepha-

Interventional Treatment of Portal Hypertension

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disconnection of the distal (portal) or proxi­ mal (hepatic-venous) junctions of the shunt, necessitating implantation of an additional stent (fig. I). During follow-up. Duplex sonography is the most important tool for assessing hepatic hemodynamics and shunt patency. Preoperatively. the majority of the patients had signifi­ cant prograde intrahepatic portal perfusion and slow extrahepatic portal blood flow veloc­ ity (table l). Establishment of the TIPS is accompanied by (1) a significant increase of the extrahepatic portal flow velocity and por­ tal flow: (2) stagnation of the intrahepatic por­ tal perfusion: (3) high flow velocity within the shunt, and (4) increase of the arterial diastolic flow velocity and decrease of resistance (ta­

Table 1. Duplex-sonographic findings before and after stent implantation, and criteria for radiologic réévaluation

Before

After

Stent mean How velocity, cm/s

-

Portal vein mean flow velocity, cm/s

8.4 ± 4.41 I8.7 + 5.21

Percentage of patients with regular intrahepatic portal flow direction

81

61 ± 151

19

Réévaluation indicated

Interventional treatment of portal hypertension.

For many years now, percutaneous transhepatic and transjugular approaches to the portal vein have been applied by gastroenterologists and radiologists...
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