Portal hypertensive bleeding: Operative devascularization

Treatment of esophagogastric varices

This chapter addresses the role of devascularization procedures in the management of portal hypertensive bleeding. The management of variceal bleeding is based on the underlying cause, liver function, presentation, and the patient’s clinical condition. Several nonsurgical therapeutic options are available to manage an acute bleeding episode and prevent subsequent episodes (see Chapters 80 , 81 , and 84 ). The roles of other treatment modalities, including pharmacotherapy (see Chapter 80 ), endoscopic therapy (see Chapter 81 ), transjugular intrahepatic portosystemic shunt (TIPS) (see Chapter 85 ), and portosystemic shunts (see Chapters 84 and 85 ), are discussed in other chapters in this book.

Bleeding from esophageal and gastric varices is the most life-threatening acute manifestation of portal hypertension and is a cause of significant morbidity and mortality. ^, Variceal bleeding is commonly from esophageal varices, and although primary hemorrhage from gastric varices is uncommon, it is more difficult to control and has higher morbidity and mortality. ^, The mortality from an acute episode of bleeding depends on the patient’s liver function status and clinical status. With the advent of pharmacologic agents, endoscopic procedures, including sclerotherapy, variceal band ligation, and glue injection, and radiologic procedures, such as TIPS and balloon-occluded retrograde transvenous obliteration (see Chapter 30 ), improved control of variceal bleed has been possible. ^, ^, In the last decade, with standardized approaches using these nonsurgical options in patients with acute variceal hemorrhage, the mortality rate, which was reported as high as 30% to 40%, has come down to 14% to 15%. ^,

Of patients with variceal bleeding, 10% to 15% do not respond to nonoperative methods and require surgical intervention. Surgical options include shunt and nonshunt procedures. The role of shunts is discussed in Chapters 84 and 85 . In patients with chronic liver disease and significant functional compromise, nonselective shunts have an unacceptably high incidence of encephalopathy and hepatic decompensation. ^, In advanced stages of liver failure, liver transplantation will be a definitive treatment (see Chapter 105 ), with other modalities bridging the interim waiting period. Devascularization procedures are directed toward varices in the esophagus and the stomach. Compared with TIPS and surgical shunts, the devascularization procedures maintain portal perfusion and hepatocyte function, thereby resulting in a much lower incidence of postoperative hepatic dysfunction and encephalopathy. Besides, the applications of shunting operations are limited in patients with extensive thrombosis of the mesenteric venous system, in both cirrhotic and noncirrhotic settings. In addition, nonshunting operations do not alter vascular anatomy and do not complicate future liver transplant surgery, although they can cause significant upper abdominal adhesions, which may be associated with increased bleeding at the time of transplantation.

Devascularization procedures are now performed less frequently; however, when most nonsurgical measures fail in an emergent scenario, and when radiologic therapies are not feasible, their role still exists in the surgical armamentarium available to salvage critical situations of variceal bleeding. In elective situations in patients without cirrhosis with no shuntable vein and difficult-to-obliterate varices, devascularization is the best and, at times, the only option available.

Indications

Devascularization procedures aim to control bleeding from varices in the esophagogastric region. They do not control bleeding from ectopic varices, nor do they treat the underlying disease. However, splenectomy, which is part of most described devascularization procedures, can effectively treat hypersplenism and improve liver function in some patients because of the favorable changes in splanchnic hemodynamics. Devascularization procedures can be used for primary prophylaxis of variceal bleeding, to control acute bleeding, or to prevent recurrent bleeding from esophagogastric varices.

The indications for devascularization procedures can be discussed in two scenarios: (1) patients with underlying chronic liver disease and (2) patients with a healthy liver, as in extrahepatic portal vein obstruction (EHPVO) and noncirrhotic portal fibrosis (NCPF).

In the current era, transplantation of the liver being a well-established modality (see Chapter 105 ), there are only a few indications for devascularization for the treatment of esophagogastric varices in patients with chronic liver disease. The recent American Association for the Study of Liver Diseases practice guidelines does not include devascularization procedures in their recommended practice guidelines in the acute or prophylactic setting. This may perhaps be due to the fact that the majority of patients of portal hypertension in the United States have a cirrhotic cause, and the options of nonsurgical modalities, as well as liver transplantation, are more easily available. However, in other parts of the world where the facilities are not as well developed, devascularization procedures still have a significant role to play, especially in the emergency management of esophagogastric variceal bleeding.

Devascularization, therefore, has a role as an emergency procedure when other nonsurgical methods have failed or are not a feasible option to control acute variceal bleeding or recurrent bleeding. It has been demonstrated that rebleeding after two sessions of emergency variceal sclerotherapy is unlikely to respond to further endoscopic therapy, and devascularization may be used in noncirrhotic patients and in cirrhotic patients when other modalities such as TIPS (see Chapter 85 ) are not feasible or not available. ^, Additionally, in patients who are not candidates for transplantation and have high-grade varices with symptomatic hypersplenism, devascularization is performed for primary prophylaxis of bleeding and treatment of hypersplenism. Devascularization is contraindicated in severely compromised liver dysfunction, as in Child-Pugh C patients, except perhaps as a “last ditch” effort. Occasionally, when TIPS is unavailable, this procedure has been used as a bridge to liver transplantation because, unlike a portocaval shunt, it does not alter the vascular anatomy and complicate future transplantation surgery.

In a noncirrhotic cause, for example, EHPVO and NCPF, shunt surgery is usually the preferred option (see Chapters 83 and 84 ) However, devascularization is indicated in patients with noncirrhotic portal hypertension with unfavorable vascular anatomy, such as the absence of a shuntable vein in patients with extensive mesenteric venous thrombosis or an inadequate vein size to permit a shunt, which often may be detected intraoperatively. In noncirrhotic patients with acute variceal bleeding, devascularization is indicated when other modalities have failed to control acute bleeding and the patient is unstable to undergo a shunt procedure, even when the shunt is technically feasible. In one series, 16 of 114 patients (14%) with EHPVO underwent devascularization. The procedure has been reported to give good results in children with massive splenomegaly with hypersplenism secondary to EHPVO. ^, Goyal et al. suggested that esophagogastric devascularization is an operation that can be performed even in hospitals where facilities and expertise for shunt procedures and interventional procedures like TIPS are not available.

The devascularization procedure may be indicated in some other situations, such as portal biliopathy in the absence of a shuntable vein and chronic pancreatitis with portal hypertension.

In this chapter, splenectomy alone has not been separately considered because, in noncirrhotic patients needing splenectomy for symptomatic hypersplenism, a shunt is commonly added if there is a shuntable vein. In noncirrhotic patients with an unshuntable vein and patients with chronic liver disease, splenectomy is combined with esophagogastric devascularization. In addition, isolated splenectomy as a means of secondary prophylaxis for variceal bleeding has a 30% to 50% failure rate and hence is not advocated, ^, except in the instance of left-sided portal hypertension (i.e., isolated splenic vein thrombosis).

Surgical anatomy, pathophysiology of varices, and effects of devascularization

Anatomy and pathophysiology

To understand the basis of devascularization, the underlying anatomy that results in esophagogastric varices must be understood (see Chapter 2 ). When portal hypertension develops, there is a diversion of portal venous blood away from the liver to join the low-pressure systemic circulation by collateral pathways—natural portosystemic shunts (see Chapters 74 and 80 ). The esophagogastric region is the main site of natural portosystemic shunting. The coronary and other gastric veins are connected to tributaries of the superior vena cava by collateral channels in the submucosa of the esophagus, and in the periesophageal area (adventitial plexus). The drainage is mainly into the submucosal and subepithelial veins of the esophagus by the gastroesophageal junction. The increased blood flow and resistance in the muscularis layer of the esophagus contribute to the increase in venous pressure, resulting in the formation of dilated and tortuous varices. A three-dimensional observation reveals the intrinsic and extrinsic veins in the esophageal wall. The intrinsic veins (intramural vessels), including the submucosal, subepithelial, and the intraepithelial veins, are strongly implicated in the development of varices. Periesophageal veins comprise the extrinsic vein system and branch veins (extramural vessels) from the periesophageal collaterals enter the esophageal wall and feed the varices.

In portal hypertension, the increased venous pressure can produce varices throughout the length of the esophagus and down into the upper stomach; however, the bleeding from esophageal varices usually occurs in the lowest 5 cm of the esophagus. In the stomach, although varices are seen more often on the lesser curve, it is the less common fundal varices that are more dangerous and likely to lead to exsanguinating hemorrhage. Therefore a technique targeting extramural and intramural vessels in this vulnerable area would help in controlling or preventing bleeding from esophageal varices.

Devascularization being a variceal-directed ablative surgery, aims at the obliteration of varices or disconnection of the esophagogastric veins from the hypertensive portal tributaries. The goal of the esophagogastric devascularization is to disconnect the esophagus and stomach from this collateral system while maintaining a portosystemic shunt in place by the adventitial plexus surrounding the esophagus. Most of the described devascularization procedures have two major components:

1.
Devascularization of the esophagogastric region to reduce bleeding from the esophagogastric varices.
2.
Splenectomy, which decreases portal flow and thereby pressure, facilitates esophagogastric devascularization, and also effectively deals with hypersplenism, if present.

The devascularization of the esophagogastric region is achieved by interruption of the extramural and the intramural vessels feeding gastroesophageal varices with the maintenance of hepatic portal perfusion. Based on the targeted vessels the surgical procedures can be conceptually classified as:

1.
Devascularization procedures (Hassab type) that targets extramural vessels feeding gastroesophageal varices
2.
Devascularization procedures (Sugiura type) that focus on extramural and intramural vessels feeding gastroesophageal varices and preserving the longitudinal esophageal vessels, thereby maintaining the spontaneous portoazygos flow in the region

Evolution of devascularization procedures

The evolution of devascularization procedures can be divided into three stages. In the early 1950s and 1960s, surgery was directed toward ligation/transection of varices and esophageal transection. Boerema and Crile, in 1950, reported ligation of esophageal varices with unsatisfactory results. Walker, in 1964, reported transthoracic esophageal transection. Along similar lines, gastroesophageal resection, upper gastric transection and transabdominal esophageal transection ^, were also reported in the period, with unsatisfactory outcomes.

In the late 1960s and early 1970s, Hassab and Sugiura developed the two successful procedures named after them that describe systematic devascularization of the esophagogastric region together with splenectomy. Hassab, in 1967, described an esophagogastric devascularization completely performed through the abdominal route in portal hypertension, secondary to schistosomiasis. In 1973, Japanese surgeons Sugiura and Futagawa described a transthoracic esophageal devascularization combined with esophageal transection and an abdominal approach for splenectomy and upper stomach devascularization with vagotomy and pyloroplasty. Hassab and Sugiura and Futagawa reported good results and laid the foundation for the currently practiced devascularization procedures. Both Hassab and Sugiura procedures were subsequently modified, and currently the modified versions of these two procedures is commonly used. During the last decade, devascularization procedures are frequently performed using a minimally invasive approach. Of the two devascularization procedures, conceptually, the Sugiura-type procedures result in more thorough devascularization by interrupting extramural perforating veins and intramural portosystemic shunt feeding the varices. ^, In addition, it is the most physiologic procedure because the periesophageal spontaneous portocaval shunt is preserved to preclude a postoperative rise in portal pressure. However, despite suboptimal devascularization, Hassab-type procedures are commonly used, especially in the minimally invasive approach, perhaps because of technical simplicity and the option of effectively managing post-devascularization residual varices using an endoscopic approach.

Hassab and modified hassab devascularization procedure

Hassab developed a devascularization procedure in 1957 and reported a cumulative experience of 355 cases in 1967. Even though in this series the procedure of gastroesophageal devascularization with splenectomy was applied in cases of portal hypertension secondary to bilharzial (schistosomiasis) infestation, the procedure is recommended for other causes as well.

The Hassab devascularization procedure is performed through an abdominal incision. The options for incision include midline, extended left subcostal, or L-shaped, depending on the size of the spleen. The left lobe of the liver is freed from its attachments. Splenic artery ligation followed by splenectomy is performed. Splenectomy and ligation of short gastric veins is followed by ligation of the vessels ascending through the hiatus and the diaphragm. The gastrohepatic ligament is incised. A major part of the gastrohepatic ligament containing the left gastric vessel is divided between ligatures. The peritoneum over the intraabdominal part of the esophagus is reflected, and the abdominal esophagus is circumferentially dissected and looped with umbilical tape. This is followed by the devascularization of 3 to 4 inches (7–10 cm) of the lower esophagus and proximal stomach along with vagotomy and pyloroplasty ( Fig. 82.1 ). The abdomen is closed after the placement of a drain in the region.

FIGURE 82.1, Diagrammatic representation of the Hassab procedure.

An important aspect of the Hassab procedure is the absence of esophageal transection. Hassab suggested that portoazygous disconnection without esophageal transection was sufficient and reported that varices disappeared completely or improved in 91% of patients. However, Nakamura et al., based on endoscopic ultrasonography findings, reported that the Hassab type gastroesophageal decongestion and splenectomy is effective for the extramural connections but not for the intramural connections resulting in recurrent esophageal varices. Later Hassab suggested that combined sclerotherapy or endoscopic ligation could reduce rebleeding if there were missed obliterated esophageal perforators or if devascularization at operation was incomplete. Another critical aspect of the Hassab procedure is that the main trunk of the left gastric vessels was not preserved and the division of the left gastric vein could disrupt the spontaneous portacaval shunt between left gastric and paraesophageal veins. Disruption of the spontaneous shunt at the gastroesophageal area increases portal pressure and promotes the formation of a new collateral pathway leading to recurrence of esophageal varices and exacerbation of portal hypertension gastropathy. Therefore selective devascularization of only the branch veins that enter the wall of the esophagus and stomach was proposed as a modification of the Hassab procedure. ^, A meta-analysis of seven randomized controlled trials (RCTs) and seven nonrandomized observational clinical studies compared perioperative outcomes and postoperative complications between selective and nonselective (division of left gastric vessels) gastroesophageal devascularization. The patients who underwent selective gastroesophageal devascularization had less portal hypertensive gastropathy, rebleeding, and postoperative mortality. However, selective gastroesophageal devascularization may not be feasible in all patients. If the paraesophageal veins directly enter the esophageal wall, or if it is difficult to identify the paraesophageal vein because of the extensive varicose vessels, the left gastric vein needs to be ligated to block abnormal blood flow to the esophagogastric varices.

Sugiura and Futagawa devascularization procedure

Sugiura and Futagawa devised this devascularization procedure in 1967 and published their initial experience of 84 patients in 1973 and, subsequently, a larger experience of 671 patients in 1984. The procedure consists of a transthoracic and an abdominal procedure performed through two separate incisions. The thoracic procedure involves extensive paraesophageal devascularization up to the inferior pulmonary vein and esophageal transection. The inferior pulmonary vein is the landmark for the upper extent of devascularization because the drainage from varices to bronchial and azygous veins begins at that level. The abdominal procedure includes splenectomy, devascularization of the abdominal esophagus and upper half of the stomach with selective vagotomy, and pyloroplasty.

Contrary to general belief, Sugiura and Futagawa performed the two parts of the operation as a single stage in 55 of the 84 patients. In 29 poor-risk patients, the two parts of the operation, that is, thoracic and abdominal, were done in two stages 4 to 6 weeks apart, with transthoracic being the first stage in 21 patients and transabdominal in 8 patients.

The Sugiura and Futagawa procedure resembles the Hassab procedure in terms of performing splenectomy and devascularization directed to the paraesophagogastric area. However, in contrast to the Hassab procedure, only the transverse branches to the esophagus are ligated, preserving the paraesophageal longitudinal channels and left gastric vessels. In addition, esophageal transection is added to disrupt intramural portosystemic connections and prevent revascularization of the esophageal varices from the intramural vessels. Thus the Sugiura procedure divides extramural perforating veins and intramural portosystemic shunt feeding the varices while preserving periesophageal portocaval shunt. Splenectomy and preservation of portacaval shunt between left gastric and paraesophageal veins reduces portal pressure but not to the extent of a total shunt procedure, thus lessening the risk of hepatic decompensation.

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