Balloon-Occluded Antegrade Transvenous Obliteration and Variations of Balloon-Occluded Retrograde Transvenous Obliteration in the Treatment of Gastric Varices

Chapter 30: Balloon-Occluded Antegrade Transvenous Obliteration and Variations of Balloon-Occluded Retrograde Transvenous Obliteration in the Treatment of Gastric Varices

Minhaj S. Khaja and Wael E.A. Saad

Introduction

Devastating hemorrhage from portosystemic varices remains a major cause of morbidity and mortality in patients with portal hypertension (PHT).1 Endovascular and surgical portosystemic shunting procedures are effective at reducing the portal pressure but may result in serious complications such as encephalopathy or hepatic insufficiency.² Additionally, even with a lowered portosystemic gradient, high-risk varices, such as those found in the gastric antrum, may still be at risk of hemorrhage.³ Embolization of varices using macroscopic coils or glue is commonly recommended but also fails to eliminate this risk entirely.⁴ Chemical-based sclerosis of varices, although frequently resulting in worsened PHT, have proven to be very effective in eradicating the varices at risk.⁵

Because many variceal systems have multiple feeding and multiple draining pathways, combinations of antegrade and retrograde techniques are frequently useful. Balloon-occluded transvenous obliteration from the systemic veins is referred to as balloon-occluded retrograde transvenous obliteration (BRTO), and balloon-occluded transvenous obliteration from the portal veins is referred to as balloon-occluded antegrade transvenous obliteration (BATO) ( Fig. 30.1; Fig. 30.2).⁶

BATO is a collective term referring to three technical approaches: percutaneous transhepatic obliteration (PTO), obliteration via transjugular portosystemic shunt (TIPS) access ( Fig. 30.2a), and other unconventional accesses, including transiliocolic vein obliteration (TIO).⁶ This chapter reviews variations of conventional BRTO, including BATO, combined BATO and BRTO, and use of vessels other than the conventional left renal vein.

Technique

The first choice of access for endovascular obliteration of gastric varices is via the traditional transrenal route ( Fig. 30.1).^7–10 Alternative routes are used for gastric varices when there is no gastrorenal shunt^11–14 or as additional access to the transrenal BRTO route.^15,16 Further alternative routes for transvenous obliteration are used in the management of nongastric varices (ectopic varices) such as duodenal, mesenteric, and stomal varices.^17–28

Alternative or adjunctive routes can be classified into portal venous access routes and systemic venous access routes. The most common alternative route described is the percutaneous transhepatic route, which is commonly referred to in the Japanese literature as PTO.^15,16 Less commonly used alternative access methods include but are not confined to transcaval, transphrenic, transileocolic, trans-TIPS, transgonadal, transazygous, and transrenal capsular vein approaches.^17–28

Fig. 30.1 The basic approach of the conventional balloon-occluded retrograde transvenous obliteration (BRTO) procedure. (a) BRTO through a transfemoral approach with the balloon in the gastrorenal shunt. BRTO is obliteration from the systemic vein side, and balloon-occluded antegrade transvenous obliteration is obliteration from the portal venous side. (b) BRTO through a transfemoral approach with the balloon in the gastrorenal shunt. GV: gastric varices. (With permission from Saad WE, Kitanosono T, Koizumi J, Hirota S. The conventional balloon-occluded retrograde transvenous obliteration procedure: indications, contraindications and technical applications. Tech Vasc Intervent Radiol 2013;16:101–151.)

Fig. 30.2 Balloon-occluded antegrade transvenous obliteration (BATO). Demonstration of BATO (balloon occlusion from the portal venous side) and its subclassification into percutaneous transhepatic obliteration (PTO: a) and trans-TIPS (transjugular intrahepatic portosystemic shunt: b) obliteration. GV: gastric varices. (c,d) Illustration demonstrating trans-TIPS BATO (c) and a fluoroscopic image of a trans-TIPS BATO (d). The illustration depicts the BATO balloon in the posterior gastric vein, and the fluoroscopic image demonstrates an air-filled BATO balloon (hollow arrow) occluding the left gastric vein (coronary vein). (With permission from Saad WE, Kitanosono T, Koizumi J, Hirota S. The conventional balloon-occluded retrograde transvenous obliteration procedure: indications, contraindications and technical applications. Tech Vasc Intervent Radiol 2013;16:101–151.)

Balloon-Occluded Antegrade Transvenous Obliteration

Balloon-occluded antegrade transvenous obliteration is balloon-assisted sclerosant obliteration of varices from a portal venous approach and not from the traditional retrograde approach (BRTO) from the systemic veins. It includes the percutaneous transhepatic approach, trans-TIPS approach, and (percutaneous or open surgical cutdown) approaches via ileocolic veins or mesenteric tributaries (TIO).

Fig. 30.3 Percutaneous transhepatic access for the purpose of a percutaneous transhepatic obliteration procedure. Fluoroscopic image (a) and a digitally subtracted portogram (b) alternative during a limited portogram on access of the right-sided portal vein branches with a 21-gauge needle. The operator passes the 21-gauge needle into the right hepatic lobe. Contrast is injected through the needle (solid black arrow at needle tip) as it is retracted. The needle retraction is stopped when a small portal vein branch is visualized (dashed arrows). This technique is identical to that of percutaneous transhepatic cholangiography. (c) Fluoroscopic image with a 0.018-inch guidewire (dashed arrows) (Terumo, Corp, Tokyo, Japan) being advanced through the 21-gauge needle (solid arrow at needle tip). The 0.018-inch guidewire arcs into a lower portal vein branch, where the wire tip rests in this image. (d) Fluoroscopic image obtained as the 0.018-inch guidewire (dashed arrows) is being advanced farther through the 21-gauge needle (solid arrow at needle tip) and into the more central (and larger) right-sided portal vein branches. The 0.018-inch guidewire is now buckled (hollow arrow), which allows the wire to pass, in an atraumatic manner, more centrally into larger portal vein branches. (e) Fluoroscopic image obtained after the 0.018-inch guidewire has been exchanged for a 0.035-inch guidewire (dashed arrows) using a transitional sheath (usually 4 to 6 French). The operator watches the 0.035-inch wire and whether it follows the expected morphology of the portal circulation. In this instance, the guidewire appears to pass down the main portal vein (MPV) and takes a left turn probably at the splenomesenteric confluence or junction (Sp-M-J) and into the splenic vein (SpV). This is a probability and cannot be a certainty without venography. Incidentally noted is a Rosen wire in the right hepatic vein (RHV). (With permission from Saad WE, Kitanosono T, Koizumi J. Balloon-occluded antegrade transvenous obliteration with or without balloon-occluded retrograde transvenous obliteration for the management of gastric varices: concept & technical applications. Tech Vasc Intervent Radiol 2012;15:203–225.)

Portal Venous Routes

Percutaneous transhepatic obliteration is actually the first described route used solely for the obliteration (embolization) of gastric and esophageal varices. PTO, commonly used in the 1970s, predates the TIPS era.29–33 With the advent of BRTO in the early 1990s, it has been used as a second choice approach or an adjunct to the traditional BRTO approach.^15,16 PTO is the most commonly described alternative or adjunctive access.^15,16 The portal access is obtained similarly to a right-sided percutaneous transhepatic cholangiography (PTC) and can be performed under moderate sedation ( Fig. 30.3; Fig. 30.4). General anesthesia may be helpful in patients who cannot tolerate the procedure under moderate sedation or if the operator predicts a prolonged intervention involving a PTO and BRTO.

Fig. 30.4 Percutaneous transhepatic access and portography for the purpose of a percutaneous transhepatic obliteration procedure. Digitally subtracted portogram (a) and fluoroscopic image (b) during a limited portogram on access of the right-sided portal vein branches with a 21-gauge needle. The operator passes the 21-gauge needle into the right hepatic lobe. Contrast is injected through the needle (solid white arrow at needle tip) as it is retracted. The needle retraction is stopped when a small portal vein branch is visualized (dashed arrows). (c) Fluoroscopic image with a 0.018-inch guidewire (dashed arrows) (Terumo, Corp, Tokyo, Japan) being advanced through the 21-gauge needle (solid arrow at needle tip). The 0.018-inch guidewire (dashed arrows) buckles and conforms to the accessed portal vein branch (a,b). (d) Fluoroscopic image obtained after the 0.018-inch guidewire has been exchanged for a 0.035-inch guidewire (white dashed arrows) using a transitional sheath (usually 4 to 6 French). The operator watches the 0.035-inch wire (black dashed arrows) as it is pushed (hollow arrow depicting directional central push) centrally. The 0.035-inch wire is a soft floppytipped Benston wire (Cook Corp, Bloomington, IN), which has a propensity to buckle in an atraumatic manner into the more central larger portal vein branches. (e) Fluoroscopic image obtained after the 0.035-inch guidewire (dashed arrows) was passed more centrally. The 0.035-inch wire follows the expected morphology of the portal circulation in the main portal vein. (f) Fluoroscopic image obtained after a short (11-cm) 7-Fr sheath (solid white arrow) over the 0.035-inch guidewire (dashed black arrows). (g,h) Two digitally subtracted images of a diagnostic portal angiogram/portogram in sequence. The images demonstrate the pathologic anatomy (morphology) of the gastric varices (GV) and its draining gastrorenal shunt (GRS). Despite the relatively large GRS, contrast is observed in the intrahepatic portal vein branches (solid black arrows). The dominant portal venous feeder is the posterior gastric vein (not marked or labeled), and the left gastric vein (LGV) is relatively rudimentary. IVC: inferior vena cava; PV: main portal vein; RV: left renal vein; Sp-M-J: splenomesenteric junction (confluence of the splenic and mesenteric veins); SpV: splenic vein. (With permission from Saad WE, Kitanosono T, Koizumi J. Balloon-occluded antegrade transvenous obliteration with or without balloon-occluded retrograde transvenous obliteration for the management of gastric varices: concept and technical applications. Tech Vasc Interventional Rad 2012;15:203–225.)

The patient is placed supine with his or her arm at mid-abduction. The right upper quadrant is prepared and draped in the standard surgical manner. Some operators use real-time ultrasound to access a right-sided portal vein radical. However, the current authors use real-time fluoroscopy in an attempt to access smaller, more peripheral portal vein branches that may not be visualized clearly by ultrasound. A 21- or 22-gauge needle is passed into the right hepatic lobe ( Fig. 30.3; Fig. 30.4). Contrast is injected as the needle is retracted until a portal vein radical is visualized. After confirming location within a portal vein radical, a 0.018-inch guidewire is advanced into the more central portal vein branches. A transitional graduated dilator (Accustick, Boston Scientific, Natick, Massachusetts; or Neph-set, Cook, Inc., Bloomington, Indiana) with a metal stiffener is advanced over the wire ( Fig. 30.3; Fig. 30.4). This set is used to upsize the wire to a 0.035-inch wire. The transitional dilator is then exchanged for a vascular sheath that is appropriately sized for the occlusion catheter to be used. Planning for what type and size of occlusion catheter is based on prior imaging, which is usually computed tomography (CT) venography or magnetic resonance (MR) venography. Ideally, coronal projections or reformats would be available for planning the intervention. A 7-Fr sheath is required to accommodate most 10- to 11-mm occlusion catheters, which are usually the maximum required to occlude afferent (portal-venous side) feeders to gastric varices and ectopic varices (duodenal and mesenteric varices; see later discussion). After the adequately-sized vascular sheath is placed, a splenic, mesenteric, or portal venogram is performed that is pertinent to the varix that needs obliteration ( Fig. 30.4).

The TIPS approach is the least described alternative or adjunctive access to the portal venous system ( Fig. 30.2c,d).^26,34–36 It is usually a preexisting TIPS, and the access is rarely created for the sole purpose of the varices obliteration procedure.^34,36 In a study by Park et al,³⁷ 6.7% of BRTO cases (n = 5 of 75) were performed with a combined preexisting trans-TIPS approach and a traditional transrenal BRTO approach.³⁰ After the 9- or 10-Fr TIPS sheath is placed via standard approach, a splenic, mesenteric, or portal venogram is performed that is pertinent to the varix that needs obliteration ( Fig. 30.5).

The advantages of this approach is that it is commonly performed through a preexisting TIPS, and no additional access risk is taken.^34–36 However, the largest disadvantage of this access is that it is an invasive route and takes time and resources to establish. In addition, it is a long and indirect access route (especially compared with the percutaneous transhepatic route), particularly when the target vessel is a distance from the liver such as gastric varices and distal colonic.

After the portal venous branches leading to the varices in question are identified, the operator must plan occlusion of these branches. The smaller veins are embolized with coils or vascular plugs. After the “debranching” of the gastric varix is performed, the major (largest) portal venous branch is occluded using the balloon-occlusion catheter ( Fig. 30.6; Fig. 30.7). If the access to the portal circulation is via an established TIPS, two balloon-occlusion catheters can be passed through the TIPS and occlude the two major portal venous branches (if any).