Injuries to the liver and biliary tract

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Chapter 102 Injuries to the liver and biliary tract

Overview

The surgeon attempting to control torrential bleeding from a high-grade liver injury faces a formidable challenge. The source of bleeding is often difficult to control, and there is only a narrow window of opportunity to save the patient’s life prior to the onset of hypothermia, acidosis, and coagulopathy—the markers of an irreversible physiologic insult. Furthermore, the bloodless and meticulous resection techniques of elective hepatobiliary surgery do not apply in this dramatic race against time in a hostile physiologic environment. It is therefore not surprising that the management of major liver injuries has always been one of the most demanding aspects of trauma surgery.

The evolution of the management of liver injury over the past century reflects the rapid progression of trauma surgery as a surgical discipline. The initial therapeutic nihilism evolved as pioneers of a new era attempted formal major hepatic resections, and these were advocated and applauded. Disappointing results with this aggressive approach and better understanding of the injured patient’s physiology led to a paradigm shift toward damage control that has dominated modern trauma surgery since the early 1990s. At the same time, better understanding of the natural history of liver injuries in hemodynamically stable patients has led to increased nonoperative management utilizing an array of modern imaging and minimally invasive technologies.

This chapter presents the current approach to hepatobiliary injuries from the perspective of the trauma surgeon, describing the approach to the three major clinical patterns of liver trauma and emphasizing the importance of tailoring the approach to the patient’s specific anatomic and physiologic circumstances. Finally, the principles and techniques of operative management for hepatobiliary trauma are reviewed, emphasizing the fundamental differences between emergency and elective hepatobiliary operations.

Evolution of the Approach to Hepatic Trauma

More than a century ago, Pringle (1908) described hepatic vascular inflow occlusion in a trauma patient by manual compression of the hepatoduodenal ligament, a maneuver that bears his name. Although less often appreciated, Pringle also described exsanguinating hemorrhage from the liver following hematoma decompression during laparotomy and discussed the use of packing to control bleeding from the liver. Packing is therefore not a new concept. Between the turn of the twentieth century and World War II, surgeons packed deep liver lacerations and sometimes added sutures over the pack to achieve tamponade (Schroeder, 1906).

As techniques for selective hemostasis of liver injuries evolved during World War II and later in Vietnam, packing acquired a bad reputation and was abandoned in favor of alternatives such as deep liver sutures and hepatic artery ligation (Aaron et al, 1975; Lewis et al, 1974; Mays, 1967). The report of anatomic right hepatectomy by Lortat-Jacob and Robert in 1952 and the subsequent dissemination of the technical aspects of the operation (Quattlebaum & Quattlebaum, 1959) was rapidly followed by enthusiastic reports of the successful application of these formal resection techniques to trauma (Ackroyd et al, 1969; McClelland et al, 1964).

In the late 1970s, packing reemerged as a valid hemostatic technique for major liver injuries. In 1976, Lucas reported 3 patients in a series of 637 who survived packing (Lucas & Ledgerwood, 1976), and 3 years later, Calne reported 4 additional patients transferred to their hospital with liver packs in place (Calne et al, 1979). These and other reports (Malhotra et al, 2000) coincided with a growing realization among surgeons that major formal hepatic resection in critically injured patients is ill advised, because the combination of severe trauma and extensive surgery often leads to an irreversible physiologic insult and death (Fang et al, 2000).

The reintroduction of packing in the 1990s was the harbinger of a major paradigm shift in trauma surgery, from long and complex definitive procedures to a staged approach that was aptly referred to as damage control (Rotondo et al, 1993). In this new paradigm, the goals of the initial operation are limited to rapid control of bleeding and spillage of intestinal contents. This is followed by resuscitation of the patient in the surgical ICU followed by a planned reoperation for definitive reconstruction of the anatomy several days later. By the beginning of the new millennium, this new approach had become the standard of care for major abdominal trauma (Johnson et al, 2001; Shapiro et al, 2000), thus packing and temporary abdominal closure replaced hepatectomy as the dominant approach for major hepatic wounds (Johnson et al, 2001; Knudson et al, 1990; Malhotra et al, 2000; Pachter et al, 1996).

The application of nonoperative management to liver injuries in the last 15 years represents a similarly dramatic revolution. Computed tomography (CT) permitted precise delineation of the anatomy of injured abdominal solid organs. With better appreciation of the natural history of these injuries came an increasingly conservative approach. Nonoperative management was initially implemented with striking success for pediatric splenic trauma (Aronson et al, 1977) and was then successfully applied to the pediatric liver (Karp et al, 1983) and subsequently to the adult spleen and liver (Meyer et al, 1985).

Since the early 1990s, nonoperative management has evolved into the standard of care for blunt hepatic trauma in hemodynamically stable patients (Stein & Scalea, 2006). However, in recent years, it has also become apparent that the conservative approach requires more than close monitoring. In fact, these patients often require adjunctive imaging and interventional techniques to manage the sequelae of major liver trauma (see Section II and Chapters 27 and 28; Carrillo et al, 1999). The most important of these adjuncts is selective angiographic embolization of hepatic artery branches, which has largely replaced operative ligation of the right or left hepatic artery at the hilum (see Chapter 28; Wahl et al, 2002).

Surgical Anatomy of the Liver from the Trauma Surgeon’s Perspective (See Chapters 1A and 1B)

Trauma surgeons view the liver as having two vascular pedicles: the inflow pedicle, comprising the portal vein and hepatic artery, is easily accessible in the hepatoduodenal ligament and is controlled by the Pringle maneuver; the outflow pedicle, comprising hepatic veins and retrohepatic inferior vena cava, is virtually inaccessible in the massively bleeding trauma patient, and total vascular isolation of the liver is rarely a practical option in this situation.

The American Association for the Surgery of Trauma (AAST) published a liver injury scale that creates a unified framework for describing the severity of hepatic trauma (Table 102.1, Fig. 102.1; Moore et al, 1995). This scale is useful not only as a descriptive tool but also as an outcome predictor that facilitates comparisons across groups of patients.

From the operating surgeon’s perspective, the AAST Liver Injury Scale translates into three types of injuries:

The approach to each type of injury depends on the patient’s hemodynamic stability and the cumulative physiologic insult. The segmental anatomy of the liver has little relevance in the trauma patient except as a way to describe the location of injuries.

The Stable Patient with Blunt Hepatic Injury

Blunt hepatic trauma in a hemodynamically stable patient is typically discovered on CT scan. If the patient is stable with no signs of peritoneal irritation, presumably indicating a hollow viscus injury, the current standard of care is nonoperative management, regardless of the grade or extent of the injury (McVay et al, 2008). Although the overall success rate of nonoperative management of hepatic trauma ranges between 85% and 98% (Croce et al, 1995; Malhotra et al, 2000; Pachter et al, 1996; Velmahos et al, 2003), high grades of injury carry a greater risk of failure and often require adjunctive measures and a multidisciplinary approach as described below (Carrillo et al, 1999; Sriussadaporn et al, 2002).

Practical Aspects of Nonoperative Management

Stable patients with high-grade liver injuries (grade III and above) are admitted to the intensive care unit for close hemodynamic monitoring and serial abdominal examination. This must include careful palpation of the liver to assess for new tenderness or any increase in liver size; both are indicative of intrahepatic hemorrhage. Many of these patients have associated injuries, such as traumatic brain injury or lung contusions, which also require intensive care. Monitoring bladder pressures for early recognition of intraabdominal hypertension is indicated in patients who have received massive fluid resuscitation and in those who have a firm, distended abdomen (Fusco et al, 2001; Yang et al, 2002).

The duration of ICU monitoring depends on the grade of injury. In general, patients with isolated liver injuries who remain stable are transferred to ward beds after 36 to 48 hours and can be discharged within a week. Routinely obtained laboratory studies include a complete blood count, coagulation profile, and also liver function tests, although these are less important.

The question of routine follow-up imaging is controversial (Alonso et al, 2003). Although routine follow-up imaging is not indicated, most patients with high-grade injuries undergo subsequent CT scans in search of complications such as biloma or hepatic necrosis or because of associated injuries. Fever, leukocytosis, unexplained drops in hematocrit, and a rising bilirubin are obvious indications for repeat imaging (Pachter et al, 1996).

Faliure of Nonoperative Management

Failure of nonoperative management is an uncommon but potentially life-threatening complication that should be recognized early and addressed aggressively (Galvan & Peitzman, 2006). Ongoing bleeding is the major cause of failure. Evidence of ongoing hemorrhage includes hypotension, falling hematocrit, an increase in liver size, or the onset of new or increased pain in the right upper quadrant. If the patient is stable, a repeat CT scan will demonstrate the bleeding, which can then be controlled by angiographic embolization (Misselbeck et al, 2009). The patient in shock is urgently taken to the operating room for laparotomy. The complications of nonoperative management are listed in Box 102.1.

Adjuncts to Nonoperative Management

Adjunctive modalities have a crucial role in the nonoperative management of hepatic trauma. These modalities include angiography, image-guided drainage, endoscopic retrograde cholangiopancreatography (ERCP), and laparoscopy (see Chapters 18, 19, 21, and 28; Carrillo et al, 2010).

Angiography is by far the most important adjunct. A “blush” of intravenous contrast on CT scan (i.e., active extravasation) typically results from injury to a branch of the hepatic artery (Fig. 102.2). This blush is an indication for selective angiographic embolization of the bleeding vessel to prevent pseudoaneurysm formation and delayed hemorrhage (Demetriades et al, 2006; Eubanks et al, 2003).

A blush on CT scan is by no means the only indication for angiography. Evidence suggests that liberal use of angiography for any high-grade liver injury is safe and effective, because significant injury to lobar and segmental vessels may occur without a blush, and if left untreated, this may lead to delayed hemorrhage (Mohr et al, 2003).

CT-guided percutaneous drainage plays a key role in nonoperative management, because bile collections are common around the injured liver (Castagnetti et al, 2006). Such drainage obviates the need for laparotomy in the majority of cases. Persistent high-output bile drainage from a percutaneously placed drain indicates injury to a segmental or lobar bile duct. In these patients, ERCP may be used to delineate the site of injury and to decompress the biliary tree by endoscopic papillotomy and stenting (Lubezky et al, 2006); however, in the absence of ductal isolation, adequate external drainage should be sufficient for fistula closure. Image-guided percutaneous drainage is also useful in addressing perihepatic or intrahepatic abscesses.

Delayed laparoscopic lavage is emerging as another useful adjunct to conservative management (Carrillo et al, 2001; Franklin et al, 2007). This minimally invasive procedure is indicated when the patient fails to thrive, with persistent low-grade fever and other signs of ongoing systemic inflammatory response. Port placement is similar to a laparoscopic cholecystectomy with a single subhepatic lateral port. The injured liver is inspected, perihepatic collections are drained and cultured under direct vision, and the infected “rind” of clotted blood and bile on the surface of the liver is gently and bluntly teased off the capsule. The area of injury is typically obvious and is carefully avoided. The liver is irrigated with the suction irrigator, and drains are placed under direct vision in the relevant spaces above or below it.

Other Complications of Nonoperative Management

Rarely, a false aneurysm of a branch of the hepatic artery (Schouten van der Velden et al, 2009) will decompress into an injured biliary radical in a delayed fashion, causing hemobilia (Green et al, 2001; see Chapters 104 and 105). The patient presents weeks or months after the injury with upper gastrointestinal bleeding, jaundice, and colicky abdominal pain as a result of blood and clots in the biliary tree that are subsequently passed through the ampulla of Vater. Angiographic embolization (see Chapters 28 and 83

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