Chapter 10: Percutaneous Management of Surgically Placed Portosystemic Shunts

The first line of treatment for acute recurrent gastroesophageal variceal bleeding is medical management with endoscopic banding or sclerosis of varices. Where available, percutaneous transjugular intrahepatic portosystemic shunts (TIPS) have largely replaced surgical shunting. Elective surgery is still preferred by some authorities for portal decompression in patients with relatively good liver function (Child’s A) and who fail endoscopic treatment.1,2 These clinicians believe that surgical shunts are associated with longer periods of patency and a lower incidence of encephalopathy. They reserve the use of TIPS for Child’s B patients as a bridge to liver transplantation.

The most popular types of portal decompressive surgery include the placement of small-diameter interposition portocaval or mesocaval shunts and the splenorenal shunt.³

Shunt malfunction is usually the result of kinking, build-up of a thick mural thrombus, or complete thrombotic occlusion. The incidence of shunt occlusion is estimated to be 7% to 10%, based on rebleeding episodes, angiography, surgery, and autopsy.⁴ However, the true incidence of shunt stenosis is probably in the range of 30% or more, because shunts can become stenotic or occluded without recurrent variceal bleeding (hemodynamic stenosis without clinical dysfunction). Percutaneous recanalization of dysfunctional shunts is often such a simple operation that it should be considered a first–intention procedure for treating patients with active esophageal variceal bleeding.⁵ Moreover, adhesion and fibrosis around the surgical shunt may hinder surgical revisions of these surgically established portosystemic shunts.⁴

Diagnosis of Shunt Dysfunction

The evaluation of shunt patency is most commonly performed by Doppler ultrasound, which is reasonably accurate when shunt flow is visualized and when the cephalad segment of the superior mesenteric vein is noted to be wider than its caudal segment.⁶ However, moderate shunt stenosis can be missed. Shunts may not be visible in the presence of intestinal gas and in large abdomens. Although magnetic resonance angiography and cross-sectional imaging are probably more accurate in defining shunt patency, these studies are not commonly used, especially if the patient is actively bleeding. In stable patients the author (WS) prefers portal venous phase CT. Adjunct Doppler ultrasound to evaluate for patency and dysfunction of flow within the portal vein is also used.

When a patient with a history of having a surgical shunt is admitted with variceal hemorrhage and has failed endoscopic therapy, he or she should be considered for emergency percutaneous shunt catheterization.^7–11 If the shunt is found to have a residual lumen, then it usually can be easily and safely reopened to lower the portocaval pressure gradient to a safe level. Recanalization of a malfunctioning portosystemic shunt via the inferior vena cava (IVC) is safe, quick, and requires only standard catheter and angioplasty balloon technology. Stent placement is usually reserved for lesions that are recalcitrant to balloon angioplasty or have frequent recurrences after balloon angioplasty.

Indirect Portography

Celiac and superior mesenteric arteriography can be performed to assess the patency and hemodynamics of the shunt and portal circulation. At least 50 to 70 mL higher-concentration radiopaque media must be injected in each vessel to obtain good opacification of the portal system. For more precise visualization of H-shunts it is suggested that the mesenteric arteriogram be performed after an intraarterial vasodilator is instilled into the artery and imaging performed in a left posterior oblique position. Opacification of the shunt and the IVC indicates some degree of patency, which can allow subsequent transcaval dilatation. The reverse is not true, because some hemodynamically occluded shunts can still be recanalized (see Fig. 6.3). Opacification of the IVC alone can occur through large natural splenorenal shunts and cannot therefore be of use as a sign of surgical shunt patency.

Shunt Catheterization Through the Inferior Vena Cava

Stay updated, free articles. Join our Telegram channel

Join