Chapter 29: The Conventional Balloon-Occluded Retrograde Transvenous Obliteration Procedure Transvenous obliteration of gastric varices can be performed from the systemic-venous side (draining veins/shunts) or from the portal-venous side (portal afferent feeders). When balloon-occluded transvenous obliteration is performed from the systemic veins, it is referred to as balloon-occluded retrograde transvenous obliteration (BRTO) ( Fig. 29.1; Fig. 29.2). However, when balloon-occluded transvenous obliteration is performed from the portal vein and its afferent feeders, it is referred to as balloon-occluded antegrade transvenous obliteration (BATO) ( Fig. 29.3).1 BRTO is the conventional obliterative procedure because it is the least invasive choice of access or approach via a transfemoral, transrenal route2–5 ( Fig. 29.1; Fig. 29.2). However, BATO is considered an alternative or adjunctive approach.1,6 The objective of BRTO and BATO is complete obliteration of the gastric varices while preserving anatomical hepatopetal flow of the splenoportal circulation. This chapter discusses the indications, contraindications, and technical considerations of the conventional BRTO procedure. The indications of concomitant portal venous modulators such as splenic embolization or the creation of a transjugular intrahepatic portosystemic shunt (TIPS) are briefly mentioned. The two clinical indications for BRTO are gastric variceal bleeding (impending, prior or current or active) and, to a lesser extent, refractory debilitating hepatic encephalopathy.7 The contraindications to BRTO are only relative contraindications at best. The contraindications include (i) severe uncorrected coagulopathy (which in this clinical setting is likely caused by liver failure), (ii) splenic vein thrombosis (segmental portal hypertension), (iii) portal vein thrombosis, and (iv) uncontrolled esophageal variceal bleeding. In patients with severe, uncorrected coagulopathy, commonly associated with liver failure, BRTO is probably being performed as an emergent, heroic measure to stop life-threatening gastric variceal bleeding. This is particularly true when the alternative (TIPS) has a high mortality rate in the setting of severe hepatic failure. The most serious contraindication, although not an absolute contraindication, is chronic portal vein thrombosis in which the gastrorenal shunt (GRS) is the only splenomesenteric (splanchnic) outflow. Uncontrolled esophageal variceal bleeding can be considered a contraindication to BRTO when performed solely. To clarify, a combined TIPS with BRTO or TIPS with trans-TIPS BATO can be performed as necessary. Hypothetically, if the gastric varices are primarily supplied by the left gastric vein (which usually supplies uncontrolled esophageal varices), they usually respond to a TIPS equally as effectively as esophageal varices.8 Performing BRTO in the presence of portal vein thrombosis may have potentially grave consequences and is a serious dilemma for the team managing the patient. Because the entire splenic and mesenteric outflow may be through the GRS, closure of the shunt could cause splenic engorgement and more thrombosis and, potentially, venous mesenteric ischemia. In this scenario, BRTO, if performed at all, is performed as part of a greater portal procedure (beyond the scope of this chapter). Similar to portal vein thrombosis, performing BRTO in a patient with isolated splenic vein thrombosis is a dilemma. In the opinion of the current authors, the primary endovascular management, especially in the presence of splenomegaly, is partial splenic (arterial) embolization with or without BRTO.9 Fig. 29.1 Illustrations of common anatomy for the conventional balloon-occluded retrograde transvenous obliteration (BRTO) procedure. (a) The basic portosystemic venous anatomy of gastric varices (GVs) pertinent to the conventional BRTO procedure with the classic gastrorenal shunt (asterisk), which is more common than a direct gastrocaval shunt. (b) The basic portosystemic venous anatomy of GVs pertinent to the conventional BRTO procedure but with the less common direct gastrocaval shunt (asterisk). IVC: inferior vena cava; LGV: left gastric vein; LRV: left renal vein; MV: mesenteric vein; PGV: posterior gastric vein; PV: portal vein; SGV: short gastric vein; SV: splenic vein. (Reproduced 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. 29.3 Balloon-occluded antegrade transvenous obliteration (BATO). Illustration demonstrating 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. (Reproduced 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.) Table 29.1 Procedural Steps of the Conventional Balloon-Occluded Retrograde Transvenous Obliteration Procedure
Introduction
Indications and Contraindications
| Broad Procedural Steps | Specific Procedural Steps |
1. | Access and approach (see Fig. 29.5) | • Venous access (femoral vs. jugular) • Approach from infrarenal IVC or suprarenal IVC |
2. | Selective catheterization (see Figs. 29.6, 29.7, 29.8, 29.9, 29.10, 29.11, 29.12, 29.13) | • Catheterization of the left renal vein • Catheterization of the common stump of the adrenal vein and GRS • Selective catheterization of the GRS proper |
3. | “Trapping” of the gastric variceal system (see Figs. 29.14, 29.15, 29.16, 29.17, 29.18, 29.19, 29.20, 29.21) | • Balloon occlusion of the GRS (with balloon manipulation) • Collateral vein embolization or sclerosis • BATO debranching |
4. | Balloon-occluded retrograde venography | |
5. | Sclerosant administration (see Figs. 29.22, 29.23) | • Preferably microcatheter catheterization of the gastric variceal system • Preferably even distribution of the sclerosant mixture |
6. | Additional intraprocedural imaging (if any) (see Fig. 29.19c-e) | • Cone-beam dynamic computed tomography • Hemodynamic analysis and imaging |
7. | Indwelling sclerosant with indwelling temporary balloon or balloon-occlusion catheter | |
8. | Deflation of balloon (deflation of balloon-occlusion catheter) |
BATO: balloon-occluded antegrade transvenous obliteration; GRS: gastrorenal shunt; IVC; inferior vena cava. Reproduced 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.
Technique of the Balloon-Occluded Retrograde Transvenous Obliteration Procedure
The hemodynamic endpoint of BRTO is the complete obliteration of the gastric varices while preserving the anatomical hepatopetal flow through the splenoportal veins. The concept of BRTO ( Fig. 29.1; Fig. 29.2) is to access and occlude the GRS with subsequent reflux of sclerosant throughout the gastric variceal system without spillage into the portal circulation.2–4 The basic steps of the BRTO procedure are listed and summarized in Table 29.1. The following is a detailed description of the procedural steps of BRTO of gastric varices. For the inventory used, particularly balloon-occlusion catheters and sclerosants, see Saad et al.10
The operator should note that in the setting of active gastric variceal bleeding, transoral gastric tamponade insufflation balloons (e.g., the Blakemore tube) should be used. However, if the gastric Blakemore tube is placed and inflated, it is of utmost importance that the gastric balloon be deflated (intraprocedurally) during the catheterization stage of the BRTO procedure; if inflated, the balloon compresses and distorts the varices and creates additional difficult anatomy for the BRTO procedure ( Fig. 29.4). Additionally, the compression of the gastric varices by the Blakemore balloon will not allow for adequate filling of the varices by the sclerosant, even with appropriate balloon occlusion of the gastrorenal shunt, and complete obliteration or sclerosis of the gastric varices will be virtually impossible. As a result of incomplete obliteration, if bleeding continues after the BRTO, then a balloon-occluded antegrade transvenous obliteration, TIPS, or both is required because the draining GRS at that point will be sclerosed or thrombosed.
Fig. 29.4 Balloon-occluded retrograde transvenous obliteration (BRTO) attempt in the presence of an inflated Blakemore (gastric or fundic) balloon. (The balloon must be deflated.) Chest radiography with the upper abdomen with a Blakemore tube inflated (a,b) and pulled back in the stomach fundus (asterisk).
Access and Approach
For conventional BRTO (via the GRS), the approach is invariably transrenal to the GRS.2–5 However, the access and approach to the left renal vein can be transfemoral or transjugular2–4,6,11–16 ( Fig. 29.1; Fig. 29.2). The transjugular approach is advantageous in that it is less likely to introduce infection compared with the transfemoral approach and is likely better tolerated by the patient. Bacteremia suspected from the indwelling balloon has been described in 2.4% of cases.11 However, the transjugular approach requires longer reinforced sheaths to reach the GRS (at least 50- to 55-cm length), which may not be easily available to all operators. Conversely, the transfemoral approach requires shorter reinforced sheaths (40- to 45-cm length) and frees the right internal jugular vein for additional access, particularly when adjunctive transcaval phrenic vein embolization is required or for additional TIPS creation. The primary advantage of the transfemoral approach is the “pushability” of the coaxial wire and catheter system. Selection of the left renal vein and GRS from a jugular approach usually requires Cobra-shaped selective catheters and balloon-occlusion catheters. Alternatively, a Simmons-shaped catheter is usually required to select the GRS from a femoral approach, although Cobra-shaped catheters may also be used.
The distance between the common stump (of the left adrenal vein and GRS) and the inferior vena cava (IVC) can vary. Additionally, the origin of the common stump may vary in angulation as it arises from the superior aspect of the left renal vein ( Fig. 29.5; Fig. 29.6). The GRS is easier to select from a femoral approach when it is situated closer to the IVC and has a steeper (more perpendicular) angle with relation to the renal vein. Conversely, selection of the GRS is easier from the jugular approach when it originates farther from the IVC and has a shallower (more parallel) angle with the left renal vein ( Fig. 29.6). However, this anatomical and technical divide may be moot when using the transfemoral pullback straight-sheath selection approach described later.
Fig. 29.5 Anatomy of the distal gastrorenal shunt (GRS) and its venous outflow. The GRS commonly does not empty directly into the left renal vein (LRV) but actually empties in the LRV via a common stump (asterisk) with the left adrenal vein (open arrow). Commonly, there is a weblike narrowing (solid black arrow) at the junction of the GRS (the GRS proper) with the common trunk (asterisk). IVC: inferior vena cava. (Reproduced 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.)
Catheter Selection of the Gastrorenal Shunt
The selection of the GRS is actually a three-step process, and any one of the steps can pose a significant technical challenge to the catheter selection process. The three-in-one selection includes (i) from the IVC to the left renal vein, (ii) from the left renal vein to the common stump of the left adrenal vein and the GRS, and (iii) from the common stump to the GRS proper ( Fig. 29.7). The complexity of the selection is because the GRS is commonly a gastroadrenorenal shunt ( Fig. 29.8) where the gastric variceal drainage (the shunt) merges with the left adrenal vein to form a common stump (asterisks in Fig. 29.5 and Fig. 29.8).
Fig. 29.6 Choice of approach (transjugular or transfemoral) based on the varying anatomy of the distal gastrorenal shunt (GRS) and its venous outflow. The GRS commonly does not empty directly into the left renal vein (LRV) but actually empties in the LRV via a common stump with the left adrenal vein. For labeling of anatomical structure, see Fig. 29.5. (a) The takeoff of the common stump of the GRS is close to the junction of the LRV with the inferior vena cava (IVC) and makes a shallower angle (more parallel to the LRV) with the LRV. Catheterization in this setting is more favorable via a transfemoral approach. The primary factor for a transfemoral approach here is the short distance between the GRS (common stump) and the IVC. (b) The takeoff of the common stump of the GRS is more or less midway between the LRV–IVC junction and the left renal hilum. In addition, the GRS makes a shallower angle (more parallel to the LRV) with the LRV. This anatomical setting is between Fig. 29.6a and Fig. 29.6c, and catheterization in this setting can be via a transfemoral or transjugular approach (depending on operator preference and availability of inventory). (c) The takeoff of the common stump of the GRS is a distance from the junction of the LRV with the IVC and makes a steep angle (more perpendicular to the LRV) with the LRV. Catheterization in this setting is more favorable via a transjugular approach. (Reproduced 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. 29.7 Catheter selection steps of the gastrorenal shunt (GRS) from the inferior vena cava (IVC). The GRS commonly does not empty directly into the left renal vein (LRV) but actually empties in the LRV via a common stump (asterisk) with the left adrenal vein. Commonly, there is a weblike narrowing (solid black arrow) at the junction of the GRS (the GRS proper) with the common trunk (asterisk). From the IVC, the operator should select three catheter selections from the IVC to the LRV (arrow in step 1), from the LRV to the common trunk of the adrenal vein and the GRS (arrow in step 2), and from the common stump to the GRS proper (arrow in step 3). (Reproduced 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. 29.9 Catheter shape and selection of the gastrorenal shunt (GRS). (a) Illustration of a femoral approach balloon-occluded retrograde transvenous obliteration (BRTO) for obliteration of gastric varices (GVs). (b) Illustration of a jugular approach BRTO for obliteration of GVs.
For the purpose of the anatomical description below, the portosystemic shunt draining the gastric varices into the “common gastroadrenal stump/common stump” is referred to as the GRS proper. Occasionally, there is little discernible difference between the common stump and the GRS proper. However, not infrequently, a web is found across the junction of the GRS proper with the adrenal vein stump ( Fig. 29.8), which is difficult to catheterize, especially when there is very little wire and catheter “purchase” into the common stump. For further details of this anatomy, please see Chapter 28.
When no discernible difference between the adrenal vein stump and the GRS proper (and no web narrowing) is found, it is easy to make this three-stage selection using a Cobra- or Simmons-shaped balloon-occlusion catheter from a transjugular or transfemoral approach, respectively ( Fig. 29.9). However, because these balloon-occlusion catheters are not currently available in the United States, American interventionalists have to selectively catheterize the GRS proper with a selective catheter and then perform an over-wire exchange for one of the commercially available straight balloon-occlusion catheters. This exchange requires adequate stiff wire “purchase” in an area of anatomy that may not allow a lot of wire purchase. Certain techniques described later can be used to selectively catheterize the GRS proper and advance a reinforced sheath and balloon-occlusion catheter in the setting of difficult anatomy.
As discussed, Cobra-shaped catheters are typically used to select the GRS from the transjugular approach ( Fig. 29.10). However, the Cobra catheter may also be helpful in selecting the GRS proper from the common stump in the presence of a web narrowing at the GRS proper to common stump junction from a femoral approach. The Cobra shape helps catheterize the left renal vein. Next, the Cobra catheter is then flipped upward so that it “scrapes” the superior aspect of the left renal vein as it is pulled back until it selects the upward-pointing common stump. A JB-2 catheter may also be used without the need to flip the catheter upward. If the left renal vein has been successfully selected and there is room to form a reverse-shaped catheter, it can be used to select the common stump. A reverse-shaped catheter is especially helpful in selection if the common stump or the GRS proper points medially in the 9 to 11 o’clock position ( Fig. 29.8d; Fig. 29.8e). Reverse-shaped catheters that can be formed in the left renal vein include a Simmons I or an SOS-shaped catheter. A reverse-shaped Simmons II catheter is ideal for selecting the GRS in a picturesque manner ( Fig. 29.11).