Management of Stomal Varices

Chapter 33: Management of Stomal Varices


Ravi N. Srinivasa, Jeffrey Forris Beecham Chick, and Wael E.A. Saad


Introduction


Portal hypertension is associated with the formation of varices in various locations, the most common being the esophagus and stomach. Varices, however, may also occur more distally within the gastrointestinal tract, including within the small bowel, colon, rectum, and in association with intestinal stomas; these are referred to as ectopic varices.


Stomal varices (also called parastomal varices) are extraperitoneal ectopic mesenteric vessels thought to arise secondary to portal hypertension and venous obstruction from surgical scarring related to stomal creation.1 Stomal varices may also be seen, although less commonly, in association with mesenteric venous thrombosis.1 The presence of stomal varices may be associated with considerable bleeding, which, although rare, may be life threatening. They are usually not life threatening because manual/digital compression is enough to stop the bleeding until medical attention is sought.1 This chapter will discuss the anatomy, clinical presentation, classification, imaging findings, management, and outcomes of stomal varices.


Anatomy


Stomal varices may not be related to portal hypertension. The surgical creation of the intestinal stoma itself may result in focal adhesions or segmental scarring, causing constrictive effects on the adjacent venous vasculature and resulting in dilated varices.1 The afferent feeding vessels of stomal varices are typically tributaries (misnomer is branches) of the superior mesenteric vein that drain the bowel segment supplying the stoma.1 These branches exit the peritoneal cavity, take a sharp turn, and surface in the abdominal wall adjacent to the stoma.1 Nearly all stomal varices are associated with systemic venous drainage in the anterior abdominal wall; however, the degree of involvement is variable. In the majority of cases there is indirect systemic venous drainage via numerous small venous anastomoses in the subcutaneous tissues of the anterior abdominal wall. These efferent veins aggregate and empty into the ipsilateral iliofemoral vein.1


Classification


Saad et al formulated a classification system for stomal varices (images Fig. 33.1).2 Most stomal varices may be classified as type-1a and type-2a. Chronic stomal varices may progress to type-3a with a portosystemic hemodynamic component. Type-1 stomal varices have no physical portosystemic collateral connection, type-2 have a portosystemic connection with minimal flow, and type-3 have a portosystemic connection with hemodynamic shunting (images Table 33.1).13 The “a” and “b” denote the presence of mesoportal occlusion, the nonocclusive or occlusive type, respectively.13


A second classification system for stomal varices is based on the type of ostomy. The two most common types are bowel diverting ileostomy or colostomy. Urine diverting ileostomies may also be associated with stomal varices but much less commonly. In theory, colostomies are less vascular and, therefore, sclerotherapy should be performed with more caution due to the increased susceptibility to ischemic complications.1




Stomal varices may also be classified based on their bleeding patterns, focal or diffuse.5 The focal-type is linked to the so called “venous spurt,” related to a localized tuft of ectopic varices. In the focal type, the stoma has relatively normal mucosa and the bleeding sites tend to respond to focal single digit compressive therapy prior to definitive treatment.1 The physical examination in patients with focal type bleeding stomal varices is critical. Localizing the portal or mesenteric venous feeder associated with bleeding is important as it directs percutaneous sclerotherapy. The diffuse type, on the other hand, is associated with congestion and diffuse venous oozing. The diffuse-type is typically managed with transjugular intrahepatic portosystemic shunt (TIPS) decompression.1


Endoscopy and Imaging


Endoscopy is not typically utilized as a first-line diagnostic tool in the management of stomal varices because stomal varices are visible to the naked eye on physical examination. If varices are deeper within the stoma, however, endoscopic localization may be necessary.


Preprocedural computed tomographic or magnetic resonance imaging is crucial for treatment planning to exclude portal venous or mesenteric venous thrombosis as the cause for the bleeding varices. In cases of mesoportal occlusion, attempts at recanalization of the occluded vessels should be attempted first as TIPS with decompression is fruitless without a patent portomesenteric circulation. Thrombectomy may be performed via mechanical, or combination mechanical and pharmacologic, means. The pharmacologic approach may be performed with trans-superior mesenteric arterial infusion of tissue plasminogen activator, which is preferred over direct stick percutaneous transhepatic portal access secondary to increased risks of bleeding.


Cross-sectional imaging is important for pretreatment planning in order to identify the systemic venous drainage pattern in the anterior abdominal wall and iliofemoral venous system.


Doppler and grayscale ultrasound are important in the treatment algorithm. This is important as flow dynamics and directionality may be assessed.1 Ultrasound may be performed with the patient directing the operator to the site of bleeding and the operator may then identify the portal and systemic venous sides of the varices. In stomal varices associated with portal hypertension, the mesenteric venous feeder leading into the stoma demonstrates hepatofugal flow (toward the stoma). The systemic venous end should be evaluated with grayscale ultrasound to assess its compressibility. This will help ascertain the site and degree of compression necessary during sclerotherapy to avoid non-target delivery of sclerosant to the systemic circulation.



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Management


Various approaches have been described for the treatment of stomal varices, including creation of surgical shunts or liver transplantation.49 The most definitive treatment of stomal varices is reversal of the ostomy if it is medically and surgically feasible.1


There is currently no gold standard on the endovascular management of stomal varices. Endovascular management strategies include creation of TIPS, balloon-occluded retrograde transvenous obliteration (BRTO), and balloon-occluded antegrade transvenous obliteration (BATO).4,6,7 Patient-specific factors may dictate management. Patients with profound hepatic encephalopathy, metastatic disease to the liver, portal venous thrombosis, heart failure, or high model for end-stage liver disease scores may not be ideal candidates for TIPS creation,11 and in those cases direct portal puncture, or direct access to the mesenteric circulation with BRTO, BATO,3 or direct stick percutaneous sclerotherapy approaches may be the best options.


TIPS Decompression


TIPS is the most commonly described method for decompressing the portal circulation and reducing variceal bleeding.4,6,7,12 TIPS, however, is not beneficial in the setting of portomesenteric venous thrombosis. The diffuse bleeding type of stomal varices is best managed with TIPS creation with or without venous obliteration (images Fig. 33.2).


Stomal variceal bleeding may resolve quickly after the creation of a TIPS. TIPS without venous obliteration has a high rebleed rate, up to 21% to 37% in some case series.4,5,10,11 Due to the fragility of stomal varices, coil embolization is not advised due to the potential erosion of the coils through the walls of the varices. Venous obliteration with sclerosants, such as sotradecol, is preferred. Coils, however, may be used to eliminate collateral vessels in order to create stasis within stomal varices and allow sclerotherapy agents longer dwells. This is particularly helpful when a small occlusion balloon cannot be advanced to the site where venous obliteration is being performed.1 An alternative to coiling collaterals may include the use of small quantities of N-butyl cyanoacrylate or Onyx to occlude collaterals and generate static flow.9 Due to their higher viscosity and controlled delivery, they may occlude flow in adjacent draining collaterals and generate static flow within stomal varices prior to delivery of sclerosant.


Transvenous Obliteration


Transvenous obliteration may be performed as a stand-alone procedure or in combination with creation of a TIPS. As described, there are different approaches to transvenous obliteration of stomal varices including: BRTO from a systemic venous approach, BATO from a portal venous approach, and direct stick percutaneous sclerotherapy with systemic venous compression.1


A BRTO approach requires, at a minimum, type-2a varices but preferably type-3 ectopic stomal varices (images Fig. 33.3). Low-profile balloon occlusion catheters are not readily available in the United States and this approach generally requires use of coils sandwiched with sclerosant, which may be cumbersome.


The BATO approach to venous obliteration is another option that may be performed in conjunction with a TIPS, through an existing TIPS that has failed to relieve variceal bleeding, or via a transhepatic portal approach (images Fig. 33.4; images Fig. 33.5; images Fig. 33.6). Small occlusion balloons may be used in this setting to keep the sclerosant from refluxing into the portomesenteric circulation. Alternately, portal pressure may keep the sclerosant in the stomal varices provided there is no significant systemic venous outflow.1


Oct 29, 2018 | Posted by in CARDIOLOGY | Comments Off on Management of Stomal Varices
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