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Laparoscopic Anatomy of the Biliary Tree
SURGICAL ANATOMY AND EMBRYOLOGY
0039-6109/93 $0.00 + .20
LAPAROSCOPIC ANATOMY OF THE BILIARY TREE David W. Crist, MD, and Thomas R. Gadacz, MD, FACS
Cholecystectomy is one of the most commonly performed abdominal operations in general surgery. Considerable clinical experience accumulated over the past several decades has demonstrated that the traditional cholecystectomy may be performed with a low operative mobidity and mortality. 10. 17. 19. 21 The safety of the traditional cholecystectomy is due in large part to a generation of well-trained surgeons with an appreciation for the normal biliary anatomy and its frequent anatomic variations. Recently, laparoscopic cholecystectomy has replaced the traditional open cholecystectomy as the preferred initial approach for removal of the gallbladder in most institutions. Unfortunately, recent published reports have indicated that the incidence of bile duct injury following laparoscopic cholecystectomy is from two to four times higher than following open cholecystectomy.1.2. 6. 15. 16. 20. 25. 27. 30. 31 The greater incidence of ductal injuries following laparoscopic cholecystectomy may be due to a number of factors including limited experience with laparoscopic techniques, failure to achieve adequate exposure of the structures within the hepatocystic triangle, and lack of appreciation for the anatomy of the biliary tree as viewed through the laparoscope. Although laparoscopy provides a clear image of the biliary structures, they are viewed from a different perspective than during a standard cholecystectomy. During laparoscopic cholecystectomy, the surgeon has a limited view of the operative field and lacks the ability to palpate structures. In addition, the normal anatomic relationships are frequently distorted by the firm cephalad retraction of the gallbladder required for adequate exposure of the cystic duct and artery. Finally, the magnified, two-dimensional video
From the Department of Surgery, The Medical College of Georgia, Augusta, Georgia
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image may alter the appearance of otherwise familiar anatomic landmarks. This review emphasizes the basic aspects of the anatomy of the biliary tract and its frequent anatomic variations, and it applies this information to laparoscopic cholecystectomy. Recognition of biliary structures during laparoscopic procedures requires a greater familiarity of anatomy than for a standard or open procedure. ANATOMY OF THE EXTRAHEPATIC BILIARY TREE
The biliary drainage of the right and left liver is into the right and left hepatic ducts, respectively (Fig. 1). The left hepatic duct is formed within the umbilical fissure from the union of the three segmental ducts draining the left liver (segments II, III, and IV). The left hepatic duct crosses the base of segment IV (medial segment of the left lobe) in a horizontal direction to join the right hepatic duct to form the common hepatic duct. The right hepatic duct drains segments V, VI, VII, and VIII and is formed from the union of the right posterior and right anterior segmental ducts. The right posterior segmental duct is formed by the confluence of ducts draining segments VI and VII. The posterior segmental duct initially courses in a nearly horizonal direction before descending in a more vertical direction to join the anterior segmental duct. The
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Figure 1. Anatomic divisions of the gallbladder and bile ducts. (From Gadacz TR: Biliary anatomy and physiology. In Greenfield LJ, Mulholland MW, Oldham KT (eds): Surgery: Scientific Principles and Practice. Philadelphia, JB Lippincott, 1993, p 931; with permission.)
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right anterior segmental duct is formed by the union of the ducts draining segments V and VIII. The biliary drainage of the caudate lobe (segment I) is variableY In approximately 80% of individuals, the caudate lobe drains into both the right and left hepatic ducts; in 15% of patients, the caudate lobe drains only into the left hepatic duct; and in the remaining 5% of cases, the lobe is drained exclusively by the right hepatic duct. The confluence of the right and left hepatic ducts to form the common hepatic duct occurs in an extrahepatic location anterior to the portal venous bifurcation. The extrahepatic portion of the right hepatic duct is short, whereas the left hepatic duct has an extrahepatic length of 2 cm or more. The biliary confluence is separated from the posterior aspect of the quadrate lobe (segment IV) by the fibrous connective tissue of the hilar plate. The common hepatic duct descends in the hepatoduodenalligament and is joined by the cystic duct to form the common bile duct. The length of the common hepatic duct varies according to its point of union with the cystic duct. The common bile duct is approximately 8 cm in length, but like the common hepatic duct, varies in length according to the site of union of the cystic duct and common hepatic duct. The upper third, or supra duodenal portion, of the common bile duct courses downward in the free edge of the lesser omentum, anterior to the portal vein and to the right of the hepatic artery. The middle third, or retroduodenal portion, of the common bile duct passes behind the first portion of the duodenum, lateral to the portal vein and anterior to the inferior vena cava. The lower third, or intrapancreatic portion, of the common bile duct traverses the posterior aspect of the pancreas in a tunnel or groove to enter the second portion of the duodenum, where it is accompanied by the duct of Wirsung. The intramural, or intraduodenal, portion of the common bile ducts passes obliquely through the duodenal wall to enter the duodenum lumen at the papilla of Vater. The gallbladder is a pear shaped, distensible reservoir located on the undersurface of the liver within the cystic fossa. The gallbladder has a capacity of 30 to 50 mL and consists of a fundus, body, and neck or infundibulum. The fundus is the rounded portion of the gallbladder that usually extends beyond the edge of the liver. The body of the gallbladder extends from the fundus to the tapered portion, or neck, of the gallbladder. The neck occupies the deepest part of the gallbladder fossa and lies in the free portion of the hepatoduodenalligament. Dilation of the neck of the gallbladder creates a diverticulum or pouch (Hartmann's pouch), which may obscure the junction of the cystic duct with the common hepatic duct. The gallbladder may occasionally be partially or completely embedded within the liver parenchyma (intrahepatic gallbladder) or abnormally positioned beneath the left lobe of the liver. The gallbladder may also be suspended from the cystic fossa by a complete mesenteric attachment that may predispose to torsion of the gallbladder. Rare congenital anomalies of the gallbladder include gallbladder agenesis and bilobed gallbladders. The cystic duct arises from the neck of the gallbladder and passes downward in the hepatoduodenalligament to join the common hepatic
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duct at an acute angle. The length of the cystic duct is variable depending upon the location of its union with the common hepatic duct. In most instances, the cystic duct is 0.5 to 4 cm in length and joins the lateral aspect of the supraduodenal portion of the common hepatic duct at an acute angle. ANOMALIES OF THE EXTRAHEPATIC BILIARY TREE
A knowledge of the variable anatomy of the extrahepatic biliary tree is important for the general surgeon, because failure to recognize anatomic variations may result in a significant ductal injury. In 1976, Benson and Page3 described the ductal and arterial anomalies in 205 operative and cadaveric dissections. On the basis of this experience, they defined five ductal anomalies of significance to the surgeon during performance of a cholecystectomy (Fig. 2). In most instances, these anomalies should be easily recognized at the time of operation by careful and meticulous dissection. One of the most common ductal variations is the presence of a long cystic duct with a low union with the common hepatic duct. The long cystic duct may run parallel to the common hepatic duct for a variable distance, or spiral anterior or posterior to the common hepatic duct to form a left-sided junction. In both situations, the cystic duct is usually closely adherent to the hepatic duct for a variable length. Efforts to display the entire length of the cystic duct and its union with the common hepatic duct may result in a ductal injury and should be avoided. The cystic duct may also join the common hepatic duct near the hepatic duct confluence or enter the right hepatic duct or a right segmental duct. Accessory hepatic ducts, usually from the right lobe of the liver, may join the common hepatic duct or cystic duct. These accessory ducts often
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Figure 2. Duct anomalies. A, Long cystic duct with low fusion with common hepatic duct. B, Abnormally high fusion of cystic duct with common hepatic duct (trifurcation). C, Accessory hepatic duct. D, Cystic duct entering right hepatic duct. E, Cholecystohepatic duct. (From Benson EA. Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:854.1976; with permission.)
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course through the hepatocystic triangle and may be injured during dissection in this area. Segmental hepatic ducts may also directly enter the common hepatic duct, cystic duct, and, occasionally, the gallbladder. Finally, small cholecystohepatic ducts from the liver may enter the gallbladder directly. If a cholecystohepatic duct is discovered during dissection of the gallbladder from the cystic fossa, it should be ligated to avoid a postoperative biliary leak. HEPATOCYSTIC TRIANGLE
In 1891, Calot defined a triangle-shaped anatomic area formed by the common hepatic duct medially, the cystic duct laterally, and the cystic artery superiorly.22, 28 In its current usage, "Calot's triangle" is generally considered to be the triangular area with an upper boundary formed by the inferior margin of the right lobe of the liver, rather than the cystic artery. This more recent interpretation of this important anatomic area is more appropriately referred to as the "hepatocystic" or "hepatobiliary" triangle, rather than "Calot's triangle." The hepatocystic triangle is of key significance to the surgeon during cholecystectomy, because a number of important structures pass through this area. In most instances, the cystic artery arises as a branch of the right hepatic artery within the hepatocystic triangle. A replaced or aberrant right hepatic artery originating from the superior mesenteric artery usually courses through the medial aspect of the triangle, posterior to the cystic duct. The hepatocystic triangle may also contain aberrant or accessory hepatic ducts that join the cystic duct or common hepatic duct. During performance of a cholecystectomy, it is essential to dearly visualize the hepatocystic triangle and accurately identify all structures within the triangle. This is particularly important during a laparoscopic cholecystectomy, in which the two-dimensional video image and cephalad retraction of the gallbladder may significantly alter the surgeon's perception of these structures. ARTERIAL ANATOMY
The cystic artery arises from the hepatic artery within the hepatocystic triangle in approximately 80% of individuals. 18 As it crosses the hepatocystic triangle, the cystic artery often supplies the cystic duct with one or more small arterial branches. Although generally overlooked during an open cholecystectomy, these branches may be the source of troublesome bleeding during a laparoscopic cholecystectomy. Recently, Hugh and Kelly12 have suggested that these previously unnamed arterial branches of the cystic artery be referred to as "Calot's arteries." Near the gallbladder, the cystic artery usually divides into a superficial branch and a deep branch. The superficial branch of the cystic artery courses along the anterior surface of the gallbladder, whereas the deep branch
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passes between the gallbladder and liver within the cystic fossa. When viewed through the laparoscope, the superficial branch often appears as a cord-like structure beneath the peritoneum of the gallbladder. 26 This finding provides a useful anatomic landmark that aids in identification of the cystic artery. Anatomic variations of the hepatic and cystic arteries are recognized in approximately 50% of individuals. 3 • 5. 14 Based upon their anatomic dissections, Benson and Page3 have defined three surgically significant variations in the arterial anatomy (Fig. 3). An accessory or double cystic artery occurs in approximately 15% to 20% of individuals. 3 • 12. 18 These arteries usually arise from the right hepatic artery within the hepatocystic triangle. During dissection of the hepatocystic triangle, care should be taken to exclude an accessory cystic artery. If present, the vessel should be carefully ligated to avoid troublesome bleeding that may be difficult to control by laparoscopic techniques. In 5% to 15% of individuals, the right hepatic artery courses through the hepatocystic triangle in close proximity to the cystic duct before turning upward to enter the hilum of the liver. 3• 5 In this location, the cystic artery arises from the convex aspect of the angled or humped portion of the hepatic artery. This "caterpillar hump" right hepatic artery may easily be mistaken for the cystic artery and inadvertently ligated. The cystic artery that arises from the caterpillar hump is typically short and may easily be avulsed from the hepatic artery if excessive traction is applied to the gallbladder. The presence of a "caterpillar hump" right hepatic artery should be suspected when an unusually large "cystic artery" is viewed through the laparoscope. 26 The cystic artery may occasionally pass anterior to the common bile duct or common hepatic duct. In this location, the cystic artery, rather than the cystic duct, is usually the first structure encountered during dissection of the lower border of the hepatocystic triangleY· 26 It is usu-
Figure 3. Vascular anomalies. A and A', "Caterpillar hump" right hepatic artery. B, Right hepatic artery anterior to common hepatic (or common bile) ducts. C, Cystic artery anterior to common hepatic (or common bile) duct. D, Accessory cystic artery. (From Benson EA, Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:854, 1976; with permission.)
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ally necessary to ligate and divide such arteries early in the dissection to provide adequate exposure of the cystic duct.
ANATOMIC RELATIONSHIPS IN LAPAROSCOPIC CHOLECYSTECTOMY
The incidence of bile duct injury during laparoscopic cholecystectomy is approximately two to four times higher than during open cholecystectomy. I, 2, 6, IS, 16,20,25,27,30,31 The higher incidence of bile duct injury following laparoscopic cholecystectomy is primarily due to a combination of two factors: (1) failure to provide adequate exposure of the critical structures within the hepatocystic triangle and (2) failure to accurately define the anatomy of the hepatocystic triangle. The majority of bile duct injuries should be avoidable by a greater appreciation of the anatomy of the biliary tree as viewed through the laparoscope and by strict adherence to the principles of laparoscopic cholecystectomy that have evolved over the past several years. 9, 13, 23, 29, 32 A nasogastric tube is placed to decompress the stomach and facilitate exposure of the porta hepatis. The patient is placed in a steep reverse Trendelenburg position to displace the stomach and transverse colon caudally. A 3D-degree forward oblique viewing laparoscope is routinely used during performance of a laparoscopic cholecystectomy in our institution. The 3D-degree laparoscope provides the surgeon with an overhead view of the portal structures, similar to the view obtained during an open cholecystectomy. This overhead view greatly facilitates visualization of the common bile duct and its relationship to the cystic duct and gallbladder. When a D-degree forward viewing laparoscope is used, the critical structures within the hepatocystic triangle are viewed from an unfamiliar perspective. This change in visual orientation may result in misidentification of the common bile duct for the cystic duct. During laparoscopic cholecystectomy, adequate exposure of the hepatocystic triangle must be ensured. A grasper placed through the lateral cannula is used to reflect the fundus of the gallbladder and liver in a cephalad direction (Fig. 4). Firm cephalic retraction of the gallbladder fundus exposes the infundibulum of the gallbladder, which is grasped with a second grasping instrument placed through the midclavicular cannula. The infundibulum of the gallbladder is then retracted ifi a lateral direction (Fig. 5). This critical maneuver opens the hepatocYr'ltic triangle and separates the cystic duct from the common hepatic ductP,23 Early illustrations of the technique of laparoscopic cholecystectomy often depicted cephalic retraction on the infundibulum of the gallbladder (Fig. 6). This method of gallbladder retraction should be avoided, because it tends to collapse the hepatocystic triangle, placing the cystic duct in dangerously close proximity to the hepatic duct, hepatic artery, and hepatic duct bifurcationp,23 In addition, cephalic retraction of the gallbladder infundibulum produces tenting of the common bile duct and causes the cystic duct and common bile duct to become aligned in the
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Figure 4. A grasper placed through the most lateral trocar is used to reflect the gallbladder and liver in a cephalad direction to expose the gallbladder infundibulum. (Modified from Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:72, 1991; with permission.)
Figure 5. The gallbladder infundibulum is retracted in a lateral direction to open the hepatocystic triangle. (Modified from Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:72, 1991; with permission.)
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Dissectin2 tissues to expose cystic i:'l-. and cystic duct
Figure 6. An illustration from an atlas of laparoscopic surgery demonstrates cephalic retraction on the gallbladder infundibulum. This method of gallbladder retraction collapses the hepatocystic triangle, placing the cystic duct in close proximity to the common hepatic duct, hepatic duct bifurcation, and hepatic artery. It also causes tenting of the common bile duct, placing this structure at risk for injury. (From Zucker DA: LaparoScopic guided cholecystectomy with electrocautery dissection. In Zucker KA, Bailey RW, Reddick EJ (eds): Surgical Laparoscopy. SI. Louis, Quality Medical Publishing, 1991, p 159; with permission.)
same planey,23 When viewed through the laparoscope from an inferior perspective, the common bile duct appears to be continuous with the cystic duct and can easily be misinterpreted as a long cystic duct. Once adequate exposure is achieved, the surgeon must accurately identify the transition between the cystic duct and gallbladder infundibulum before any structure is ligated or divided. Dissection of the cystic duct should always begin high on the gallbladder infundibulum and proceed cautiously in a medial direction. The peritoneum overlying the infundibulum is gently stripped with fine dissecting forceps. The cystic duct is usually the first structure encountered during dissection of the inferior border of the hepatocystic triangleY Occasionally, an anterior cystic artery arising outside the hepatocystic triangle may pass ventral to the cystic duct. In this situation, the anterior cystic artery may be differentiated from the cystic duct by the presence of arterial pulsations and its terminal course along the surface of the gallbladder. 26 If an anterior cystic artery is present, it may be necessary to divide it to adequately expose the cystic duct. A dissection plane is developed in the fatty areolar tissue between the cystic artery and cystic duct near the gallbladder infundibulum. This is accomplished by gently spreading the tips of a fine dissecting instrument. During dissection of this plane, small arterial branches from the cystic artery supplying the cystic duct may be encounteredP' 13,26 These branches should be cauterized or clipped before they are divided to avoid troublesome bleeding. The dissection plane is further developed to create an opening in the areolar tissue of the hepatocystic triangle. This dissection may be facilitated by displacing the infundibulum of the gallbladder medially to expose the posterior aspect
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of the hepatocystic triangle. The neck of the gallbladder should be completely mobilized to to clearly visualize the transition between the gallbladder infundibulum and cystic duct. The most common mechanism of bile duct injury during laparoscopic cholecystectomy appears to be dissection of the common hepatic or common bile duct as though these structures were the cystic duct. The common hepatic or common bile duct is then divided with or without ligation of the proximal hepatic duct?, 23 This type of injury is preventable if the transition between the gallbladder and cystic duct is identified with absolute certainty before any ductal structure is ligated or divided. Once the union of the cystic duct and gallbladder infundibulum is identified, operative cholangiography may be performed. Operative cholangiography is employed liberally in our institution to detect unsuspected common bile duct stones and to develop experience with transcystic access of the common bile duct. Some investigators have advocated routine cholangiography during laparoscopic cholecystectomy to better define the anatomy of the biliary tree and thereby reduce the risk of significant bile duct injury.4,8, 13,24 Unfortunately, bile duct injuries have occurred despite the performance of intraoperative cholangiography.4, 8, 13, 24 Operative cholangiography should never be considered a substitute for accurate identification of the structures within the hepatocystic triangle. If the anatomy of this region is unclear, the surgeon should abandon the laparoscopic procedure rather than rely on cholangiographic images to guide the operative dissection. Occasionally, the gallbladder joins the common hepatic duct with a short or virtually nonexistent, wide cystic duct. Attempts to ligate a short cystic duct may compromise the lumen of the common bile duct, resulting in a postoperative biliary stricture. The risk of this injury is increased if the bile duct is tented by excessive traction placed on the infundibulum of the gallbladder. If a satisfactory closure of the cystic duct cannot be obtained without compromising the lumen of the bile duct, the procedure should be converted to an open procedure. Attempts to dissect the entire length of the cystic duct to display its union with the common hepatic duct should be avoided. Persistent efforts to display the cystic duct-common duct junction may precipitate bleeding that is difficult to control without risking injury to ductal structures. Occasionally, the cholangiogram may demonstrate a long cystic duct coursing parallel to the common hepatic duct or spirally posterior to the hepatic duct to form a left-sided union. This may falsely lead the surgeon to believe that there is a margin of safety in dissecting and ligating an abnormally long cystic duct. A long cystic duct often is closely adherent to the common hepatic duct, and efforts to dissect its entire length may result in a ductal injury. Figure 7 demonstrates a preoperative endoscopic retrograde cholangiogram (ERC) in a 17-year-old female with suspected gallbladder dysfunction. A long cystic duct is seen coursing posterior to the common hepatic duct to form a left-sided union. A supposedly uneventful laparoscopic cholecystectomy was performed. Unfortunately, the patient became jaundiced in the early postoperative period. A postoperative ERe demon-
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Figure 7. A, Preoperative ERG in a 17-year-old girl with suspected gallbladder dysfunction. Note the presence of a long cystic duct spiraling around to the common hepatic duct to form a left-sided union. B, Postoperative ERG obtained for evaluation of jaundice. The common hepatic duct has been ligated above the low-lying cystic duct insertion. The surgeon apparently assumed that the long cystic duct provided a margin of safety in the dissection and ligation of this structure.
strates a complete ductal transection above the low-lying cystic duct insertion. The cystic artery is usually readily identified within the hepatocystic triangle. The artery should be carefully ligated and divided near its entrance onto the surface of the gallbladder. Occasionally, it is necessary to individually ligate the superficial and deep branches of the cystic artery. An abnormally large "cystic artery" may suggest the presence of a "caterpillar hump" right hepatic artery coursing near the cystic duct and gallbladder infundibulum,z6 If a "caterpillar hump" right hepatic artery is present, it should be carefully dissected away from the gallbladder infundibulum to expose the cystic artery, which usually arises from the angled portion of the hepatic artery. The cystic artery arising from a "caterpillar hump" right hepatic artery is often short and may easily be avulsed if excessive traction is applied to the gallbladder? Hemorrhage in the region of the porta hepatis should be controlled by accurate identification of the bleeding source and precise placement of hemoclips or endo-loops. Maintaining exposure, irrigation of the area, and precise localization of the bleeding source are the most important maneuvers to avoid major complications. The blind application of clips or the use of cautery in an operative field obscured by blood should be avoided.
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Figure 8. Preoperative ERC in a patient with recurrent episodes of cholangitis. Close examination reveals that the right hepatic duct joins the cystic duct rather than the common hepatic duct.
After the cystic duct and cystic artery have been divided, dissection of the gallbladder from the cystic fossa must proceed with caution. An accessory or double cystic artery usually courses in the gallbladder fossa to supply the hepatic surface of the gallbladder. Accessory or aberrant hepatic ducts may pass through the hepatocystic triangle to enter the cystic duct or common hepatic duct (Fig. 8). Careful dissection of this area will enable the surgeon to accurately identify these structures. Cholecystohepatic ducts from the liver may enter the hepatic surface of the gallbladder. These ducts should be ligated to prevent a postoperative biliary leak. SUMMARY
A thorough knowledge of the anatomy of the extrahepatic biliary tree and its frequent anatomic variations is essential for performance of a safe laparoscopic cholecystectomy. The surgeon should have an appreciation for the distortions in the anatomy as a result of retraction on the gallbladder and how the direction of retraction alters the spatial relationships between the cystic duct and common bile duct. The steps in the operative procedure have been outlined to provide good exposure and optimize the identification of structures. Good exposure will enable the surgeon to identify anatomic variants; however, a thorough knowledge of these variants is necessary for safe performance of the operation.
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References 1. Bailey RW, Zucker KA, Flowers JL, et al: Laparoscopic cholecystectomy: Experience with 375 consecutive cases. Ann Surg 214:531-541,1991 2. Baird DR, Wilson JP, Mason EM, et al: An early review of 800 laparoscopic cholecystectomies at a university affiliated community teaching hospital. Am Surg 58:206-210, 1991
3. Benson EA, Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:853-860, 1976 4. Berd G, Sackier JM, Paz-Partlow M: Routine or selective intraoperative cholangiography during laparoscopic cholecystectomy? Am J Surg 161:355-360, 1991 5. Browne EZ: Variations in origin and course of the hepatic artery and its branches: Importance from surgical viewpoint. Surgery 8:424-425,1940 6. Cushieri A, Dubois F, Mouiel J, et al: The European experience with laparoscopic cholecystectomy. Am J Surg 161:385-387, 1991 7. Davidoff AM, Pappas TN, Murray EA, et al: Mechanisms of major biliary injury during laparoscopic cholecystectomy. Ann Surg 315:196-202,1992 8. Flowers JL, Zucker KA, Graham SM, et al: Laparoscopic cholangiography: Results and indications. Ann Surg 215:209-216,1992 9. Gadacz TR, Talamini MA, Lillemoe KD, et al: Laparoscopic cholecystectomy. Surg Clin North Am 70:1249-1262,1990 10. Ganey JB, Johnson PA, Prilliman PE, McSwain GR: Cholecystectomy: Clinical experience with a large series. Am J Surg 352-357,1986 11. Healey JE, Schroy PC: Anatomy of the biliary ducts within the human liver. Analysis of the prevailing pattern of branchings and the major variations of the biliary ducts. Arch Surg 66:599-616, 1953 12. Hugh TB, Kelly TB: Laparoscopic anatomy of the cystic artery. Am J Surg 163:593-595, 1992 13. Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:71-76, 1991 14. Johnston EV, Anson DJ: Variations in the formation and vascular relationships of the bile ducts. Surg Gynecol Obstet 94:669-686,1952 15. Larson GM, Vitale GC, Casey J, et al: Multipractice analysis of laparoscopic cholecystectomy in 1,983 patients. Am J Surg 163:221-226, 1992 16. Lillemoe KD, Yeo Talamini MA, et al: Selective cholangiography: Current role in laparoscopic cholecystectomy. Ann Surg 215:669-676, 1992 17. McSherry CK: Cholecystectomy: The gold standard. Am J Surg 158:174-178, 1989 18. Michels NA: The hepatic, cystic and retroduodenal arteries and their relations to the biliary ducts with samples of the entire celiacal blood supply. Ann Surg 133:503-524, 1951 19. Morgenstern L, Wong L, Berd G: Twelve hundred open cholecystectomies before the laparoscopic era. A standard for comparison. Arch Surg 127:400-403, 1992 20. Peters JH, Gibbons GD, Innes JT, et al: Complications of laparoscopic cholecystectomy. Surgery 110:769-778,1991
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21. Pickleman J, Gonzalez RP: The improving results of cholecystectomy. Arch Surg 121:930-934,1986
22. Rocko JM, Swan KG, Di Gioia JM: Calot's triangle revisited. Surg Gynecol Obstet 153:410, 1981 23. Rossi RL, Schirmer WI, Braasch JW, et al: Laparoscopic bile duct injuries: Risk factors, recognition, and repair. Arch Surg 127:596-602, 1992 24. Sackier JM, Berd G, Phillips E, et al: The role of cholangiography in laparoscopic cholecystectomy. Arch Surg 126:1021-1026, 1991 25. Schirmer BD, Edge SB, Dix J, et al: Laparoscopic cholecystectomy: Treatment of choice for symptomatic cholelithiasis. Ann Surg 213:665-677, 1991 26. Scott-Conner CEH, Hall T: Variant arterial anatomy in laparoscopic cholecystectomy. Am J Surg 163:590-592, 1992 27. The Southern Surgeons Club: A prospective analysis of 1,518 laparoscopic cholecystectomies. N Engl J Med 324:1073-1079, 1991 28. Specht MJ: Calot's triangle [letter]. JAMA 200:1186, 1967
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29. Talamini MA, Gadacz TR: Laparoscopic approach to cholecystectomy. Adv Surg 25:118,1992 30. Voyles CR, Petro AB, Meena AI, et al: A practical approach to laparoscopic cholecystectomy. Am J Surg 161:365-370, 1991 31. Wolfe BM, Gardiner BN, Leary BF, Frey CF: Endoscopic cholecystectomy: An analysis of complications. Arch Surg 126:1192-1198, 1991 32. Zucker KA, Bailey RW, Gadacz TR, et al: Laparoscopic guided cholecystectomy. Am J Surg 161:36-44, 1991
Address reprint requests to David W. Crist, MD Department of Surgery The Medical College of Georgia Augusta, GA 30912-4004
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LAPAROSCOPIC ANATOMY OF THE BILIARY TREE David W. Crist, MD, and Thomas R. Gadacz, MD, FACS
Cholecystectomy is one of the most commonly performed abdominal operations in general surgery. Considerable clinical experience accumulated over the past several decades has demonstrated that the traditional cholecystectomy may be performed with a low operative mobidity and mortality. 10. 17. 19. 21 The safety of the traditional cholecystectomy is due in large part to a generation of well-trained surgeons with an appreciation for the normal biliary anatomy and its frequent anatomic variations. Recently, laparoscopic cholecystectomy has replaced the traditional open cholecystectomy as the preferred initial approach for removal of the gallbladder in most institutions. Unfortunately, recent published reports have indicated that the incidence of bile duct injury following laparoscopic cholecystectomy is from two to four times higher than following open cholecystectomy.1.2. 6. 15. 16. 20. 25. 27. 30. 31 The greater incidence of ductal injuries following laparoscopic cholecystectomy may be due to a number of factors including limited experience with laparoscopic techniques, failure to achieve adequate exposure of the structures within the hepatocystic triangle, and lack of appreciation for the anatomy of the biliary tree as viewed through the laparoscope. Although laparoscopy provides a clear image of the biliary structures, they are viewed from a different perspective than during a standard cholecystectomy. During laparoscopic cholecystectomy, the surgeon has a limited view of the operative field and lacks the ability to palpate structures. In addition, the normal anatomic relationships are frequently distorted by the firm cephalad retraction of the gallbladder required for adequate exposure of the cystic duct and artery. Finally, the magnified, two-dimensional video
From the Department of Surgery, The Medical College of Georgia, Augusta, Georgia
SURGICAL CLINICS OF NORTH AMERICA VOLUME 73 • NUMBER 4· AUGUST 1993
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image may alter the appearance of otherwise familiar anatomic landmarks. This review emphasizes the basic aspects of the anatomy of the biliary tract and its frequent anatomic variations, and it applies this information to laparoscopic cholecystectomy. Recognition of biliary structures during laparoscopic procedures requires a greater familiarity of anatomy than for a standard or open procedure. ANATOMY OF THE EXTRAHEPATIC BILIARY TREE
The biliary drainage of the right and left liver is into the right and left hepatic ducts, respectively (Fig. 1). The left hepatic duct is formed within the umbilical fissure from the union of the three segmental ducts draining the left liver (segments II, III, and IV). The left hepatic duct crosses the base of segment IV (medial segment of the left lobe) in a horizontal direction to join the right hepatic duct to form the common hepatic duct. The right hepatic duct drains segments V, VI, VII, and VIII and is formed from the union of the right posterior and right anterior segmental ducts. The right posterior segmental duct is formed by the confluence of ducts draining segments VI and VII. The posterior segmental duct initially courses in a nearly horizonal direction before descending in a more vertical direction to join the anterior segmental duct. The
Right hepatic artery
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. Left hepatiC duct
Cystic duct .- -
Common hepatiC duct
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. -. Supraduodenal - - Retroduodenal
Gallbladder - - -
i
Fundus - - - + -
<..:::: - - Intrapancreatlc
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Papilla of Vater--- --'1,L~&=---7----- Intramural
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I I
Common bile duct
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Figure 1. Anatomic divisions of the gallbladder and bile ducts. (From Gadacz TR: Biliary anatomy and physiology. In Greenfield LJ, Mulholland MW, Oldham KT (eds): Surgery: Scientific Principles and Practice. Philadelphia, JB Lippincott, 1993, p 931; with permission.)
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right anterior segmental duct is formed by the union of the ducts draining segments V and VIII. The biliary drainage of the caudate lobe (segment I) is variableY In approximately 80% of individuals, the caudate lobe drains into both the right and left hepatic ducts; in 15% of patients, the caudate lobe drains only into the left hepatic duct; and in the remaining 5% of cases, the lobe is drained exclusively by the right hepatic duct. The confluence of the right and left hepatic ducts to form the common hepatic duct occurs in an extrahepatic location anterior to the portal venous bifurcation. The extrahepatic portion of the right hepatic duct is short, whereas the left hepatic duct has an extrahepatic length of 2 cm or more. The biliary confluence is separated from the posterior aspect of the quadrate lobe (segment IV) by the fibrous connective tissue of the hilar plate. The common hepatic duct descends in the hepatoduodenalligament and is joined by the cystic duct to form the common bile duct. The length of the common hepatic duct varies according to its point of union with the cystic duct. The common bile duct is approximately 8 cm in length, but like the common hepatic duct, varies in length according to the site of union of the cystic duct and common hepatic duct. The upper third, or supra duodenal portion, of the common bile duct courses downward in the free edge of the lesser omentum, anterior to the portal vein and to the right of the hepatic artery. The middle third, or retroduodenal portion, of the common bile duct passes behind the first portion of the duodenum, lateral to the portal vein and anterior to the inferior vena cava. The lower third, or intrapancreatic portion, of the common bile duct traverses the posterior aspect of the pancreas in a tunnel or groove to enter the second portion of the duodenum, where it is accompanied by the duct of Wirsung. The intramural, or intraduodenal, portion of the common bile ducts passes obliquely through the duodenal wall to enter the duodenum lumen at the papilla of Vater. The gallbladder is a pear shaped, distensible reservoir located on the undersurface of the liver within the cystic fossa. The gallbladder has a capacity of 30 to 50 mL and consists of a fundus, body, and neck or infundibulum. The fundus is the rounded portion of the gallbladder that usually extends beyond the edge of the liver. The body of the gallbladder extends from the fundus to the tapered portion, or neck, of the gallbladder. The neck occupies the deepest part of the gallbladder fossa and lies in the free portion of the hepatoduodenalligament. Dilation of the neck of the gallbladder creates a diverticulum or pouch (Hartmann's pouch), which may obscure the junction of the cystic duct with the common hepatic duct. The gallbladder may occasionally be partially or completely embedded within the liver parenchyma (intrahepatic gallbladder) or abnormally positioned beneath the left lobe of the liver. The gallbladder may also be suspended from the cystic fossa by a complete mesenteric attachment that may predispose to torsion of the gallbladder. Rare congenital anomalies of the gallbladder include gallbladder agenesis and bilobed gallbladders. The cystic duct arises from the neck of the gallbladder and passes downward in the hepatoduodenalligament to join the common hepatic
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duct at an acute angle. The length of the cystic duct is variable depending upon the location of its union with the common hepatic duct. In most instances, the cystic duct is 0.5 to 4 cm in length and joins the lateral aspect of the supraduodenal portion of the common hepatic duct at an acute angle. ANOMALIES OF THE EXTRAHEPATIC BILIARY TREE
A knowledge of the variable anatomy of the extrahepatic biliary tree is important for the general surgeon, because failure to recognize anatomic variations may result in a significant ductal injury. In 1976, Benson and Page3 described the ductal and arterial anomalies in 205 operative and cadaveric dissections. On the basis of this experience, they defined five ductal anomalies of significance to the surgeon during performance of a cholecystectomy (Fig. 2). In most instances, these anomalies should be easily recognized at the time of operation by careful and meticulous dissection. One of the most common ductal variations is the presence of a long cystic duct with a low union with the common hepatic duct. The long cystic duct may run parallel to the common hepatic duct for a variable distance, or spiral anterior or posterior to the common hepatic duct to form a left-sided junction. In both situations, the cystic duct is usually closely adherent to the hepatic duct for a variable length. Efforts to display the entire length of the cystic duct and its union with the common hepatic duct may result in a ductal injury and should be avoided. The cystic duct may also join the common hepatic duct near the hepatic duct confluence or enter the right hepatic duct or a right segmental duct. Accessory hepatic ducts, usually from the right lobe of the liver, may join the common hepatic duct or cystic duct. These accessory ducts often
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Figure 2. Duct anomalies. A, Long cystic duct with low fusion with common hepatic duct. B, Abnormally high fusion of cystic duct with common hepatic duct (trifurcation). C, Accessory hepatic duct. D, Cystic duct entering right hepatic duct. E, Cholecystohepatic duct. (From Benson EA. Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:854.1976; with permission.)
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course through the hepatocystic triangle and may be injured during dissection in this area. Segmental hepatic ducts may also directly enter the common hepatic duct, cystic duct, and, occasionally, the gallbladder. Finally, small cholecystohepatic ducts from the liver may enter the gallbladder directly. If a cholecystohepatic duct is discovered during dissection of the gallbladder from the cystic fossa, it should be ligated to avoid a postoperative biliary leak. HEPATOCYSTIC TRIANGLE
In 1891, Calot defined a triangle-shaped anatomic area formed by the common hepatic duct medially, the cystic duct laterally, and the cystic artery superiorly.22, 28 In its current usage, "Calot's triangle" is generally considered to be the triangular area with an upper boundary formed by the inferior margin of the right lobe of the liver, rather than the cystic artery. This more recent interpretation of this important anatomic area is more appropriately referred to as the "hepatocystic" or "hepatobiliary" triangle, rather than "Calot's triangle." The hepatocystic triangle is of key significance to the surgeon during cholecystectomy, because a number of important structures pass through this area. In most instances, the cystic artery arises as a branch of the right hepatic artery within the hepatocystic triangle. A replaced or aberrant right hepatic artery originating from the superior mesenteric artery usually courses through the medial aspect of the triangle, posterior to the cystic duct. The hepatocystic triangle may also contain aberrant or accessory hepatic ducts that join the cystic duct or common hepatic duct. During performance of a cholecystectomy, it is essential to dearly visualize the hepatocystic triangle and accurately identify all structures within the triangle. This is particularly important during a laparoscopic cholecystectomy, in which the two-dimensional video image and cephalad retraction of the gallbladder may significantly alter the surgeon's perception of these structures. ARTERIAL ANATOMY
The cystic artery arises from the hepatic artery within the hepatocystic triangle in approximately 80% of individuals. 18 As it crosses the hepatocystic triangle, the cystic artery often supplies the cystic duct with one or more small arterial branches. Although generally overlooked during an open cholecystectomy, these branches may be the source of troublesome bleeding during a laparoscopic cholecystectomy. Recently, Hugh and Kelly12 have suggested that these previously unnamed arterial branches of the cystic artery be referred to as "Calot's arteries." Near the gallbladder, the cystic artery usually divides into a superficial branch and a deep branch. The superficial branch of the cystic artery courses along the anterior surface of the gallbladder, whereas the deep branch
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passes between the gallbladder and liver within the cystic fossa. When viewed through the laparoscope, the superficial branch often appears as a cord-like structure beneath the peritoneum of the gallbladder. 26 This finding provides a useful anatomic landmark that aids in identification of the cystic artery. Anatomic variations of the hepatic and cystic arteries are recognized in approximately 50% of individuals. 3 • 5. 14 Based upon their anatomic dissections, Benson and Page3 have defined three surgically significant variations in the arterial anatomy (Fig. 3). An accessory or double cystic artery occurs in approximately 15% to 20% of individuals. 3 • 12. 18 These arteries usually arise from the right hepatic artery within the hepatocystic triangle. During dissection of the hepatocystic triangle, care should be taken to exclude an accessory cystic artery. If present, the vessel should be carefully ligated to avoid troublesome bleeding that may be difficult to control by laparoscopic techniques. In 5% to 15% of individuals, the right hepatic artery courses through the hepatocystic triangle in close proximity to the cystic duct before turning upward to enter the hilum of the liver. 3• 5 In this location, the cystic artery arises from the convex aspect of the angled or humped portion of the hepatic artery. This "caterpillar hump" right hepatic artery may easily be mistaken for the cystic artery and inadvertently ligated. The cystic artery that arises from the caterpillar hump is typically short and may easily be avulsed from the hepatic artery if excessive traction is applied to the gallbladder. The presence of a "caterpillar hump" right hepatic artery should be suspected when an unusually large "cystic artery" is viewed through the laparoscope. 26 The cystic artery may occasionally pass anterior to the common bile duct or common hepatic duct. In this location, the cystic artery, rather than the cystic duct, is usually the first structure encountered during dissection of the lower border of the hepatocystic triangleY· 26 It is usu-
Figure 3. Vascular anomalies. A and A', "Caterpillar hump" right hepatic artery. B, Right hepatic artery anterior to common hepatic (or common bile) ducts. C, Cystic artery anterior to common hepatic (or common bile) duct. D, Accessory cystic artery. (From Benson EA, Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:854, 1976; with permission.)
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ally necessary to ligate and divide such arteries early in the dissection to provide adequate exposure of the cystic duct.
ANATOMIC RELATIONSHIPS IN LAPAROSCOPIC CHOLECYSTECTOMY
The incidence of bile duct injury during laparoscopic cholecystectomy is approximately two to four times higher than during open cholecystectomy. I, 2, 6, IS, 16,20,25,27,30,31 The higher incidence of bile duct injury following laparoscopic cholecystectomy is primarily due to a combination of two factors: (1) failure to provide adequate exposure of the critical structures within the hepatocystic triangle and (2) failure to accurately define the anatomy of the hepatocystic triangle. The majority of bile duct injuries should be avoidable by a greater appreciation of the anatomy of the biliary tree as viewed through the laparoscope and by strict adherence to the principles of laparoscopic cholecystectomy that have evolved over the past several years. 9, 13, 23, 29, 32 A nasogastric tube is placed to decompress the stomach and facilitate exposure of the porta hepatis. The patient is placed in a steep reverse Trendelenburg position to displace the stomach and transverse colon caudally. A 3D-degree forward oblique viewing laparoscope is routinely used during performance of a laparoscopic cholecystectomy in our institution. The 3D-degree laparoscope provides the surgeon with an overhead view of the portal structures, similar to the view obtained during an open cholecystectomy. This overhead view greatly facilitates visualization of the common bile duct and its relationship to the cystic duct and gallbladder. When a D-degree forward viewing laparoscope is used, the critical structures within the hepatocystic triangle are viewed from an unfamiliar perspective. This change in visual orientation may result in misidentification of the common bile duct for the cystic duct. During laparoscopic cholecystectomy, adequate exposure of the hepatocystic triangle must be ensured. A grasper placed through the lateral cannula is used to reflect the fundus of the gallbladder and liver in a cephalad direction (Fig. 4). Firm cephalic retraction of the gallbladder fundus exposes the infundibulum of the gallbladder, which is grasped with a second grasping instrument placed through the midclavicular cannula. The infundibulum of the gallbladder is then retracted ifi a lateral direction (Fig. 5). This critical maneuver opens the hepatocYr'ltic triangle and separates the cystic duct from the common hepatic ductP,23 Early illustrations of the technique of laparoscopic cholecystectomy often depicted cephalic retraction on the infundibulum of the gallbladder (Fig. 6). This method of gallbladder retraction should be avoided, because it tends to collapse the hepatocystic triangle, placing the cystic duct in dangerously close proximity to the hepatic duct, hepatic artery, and hepatic duct bifurcationp,23 In addition, cephalic retraction of the gallbladder infundibulum produces tenting of the common bile duct and causes the cystic duct and common bile duct to become aligned in the
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Figure 4. A grasper placed through the most lateral trocar is used to reflect the gallbladder and liver in a cephalad direction to expose the gallbladder infundibulum. (Modified from Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:72, 1991; with permission.)
Figure 5. The gallbladder infundibulum is retracted in a lateral direction to open the hepatocystic triangle. (Modified from Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:72, 1991; with permission.)
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Dissectin2 tissues to expose cystic i:'l-. and cystic duct
Figure 6. An illustration from an atlas of laparoscopic surgery demonstrates cephalic retraction on the gallbladder infundibulum. This method of gallbladder retraction collapses the hepatocystic triangle, placing the cystic duct in close proximity to the common hepatic duct, hepatic duct bifurcation, and hepatic artery. It also causes tenting of the common bile duct, placing this structure at risk for injury. (From Zucker DA: LaparoScopic guided cholecystectomy with electrocautery dissection. In Zucker KA, Bailey RW, Reddick EJ (eds): Surgical Laparoscopy. SI. Louis, Quality Medical Publishing, 1991, p 159; with permission.)
same planey,23 When viewed through the laparoscope from an inferior perspective, the common bile duct appears to be continuous with the cystic duct and can easily be misinterpreted as a long cystic duct. Once adequate exposure is achieved, the surgeon must accurately identify the transition between the cystic duct and gallbladder infundibulum before any structure is ligated or divided. Dissection of the cystic duct should always begin high on the gallbladder infundibulum and proceed cautiously in a medial direction. The peritoneum overlying the infundibulum is gently stripped with fine dissecting forceps. The cystic duct is usually the first structure encountered during dissection of the inferior border of the hepatocystic triangleY Occasionally, an anterior cystic artery arising outside the hepatocystic triangle may pass ventral to the cystic duct. In this situation, the anterior cystic artery may be differentiated from the cystic duct by the presence of arterial pulsations and its terminal course along the surface of the gallbladder. 26 If an anterior cystic artery is present, it may be necessary to divide it to adequately expose the cystic duct. A dissection plane is developed in the fatty areolar tissue between the cystic artery and cystic duct near the gallbladder infundibulum. This is accomplished by gently spreading the tips of a fine dissecting instrument. During dissection of this plane, small arterial branches from the cystic artery supplying the cystic duct may be encounteredP' 13,26 These branches should be cauterized or clipped before they are divided to avoid troublesome bleeding. The dissection plane is further developed to create an opening in the areolar tissue of the hepatocystic triangle. This dissection may be facilitated by displacing the infundibulum of the gallbladder medially to expose the posterior aspect
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of the hepatocystic triangle. The neck of the gallbladder should be completely mobilized to to clearly visualize the transition between the gallbladder infundibulum and cystic duct. The most common mechanism of bile duct injury during laparoscopic cholecystectomy appears to be dissection of the common hepatic or common bile duct as though these structures were the cystic duct. The common hepatic or common bile duct is then divided with or without ligation of the proximal hepatic duct?, 23 This type of injury is preventable if the transition between the gallbladder and cystic duct is identified with absolute certainty before any ductal structure is ligated or divided. Once the union of the cystic duct and gallbladder infundibulum is identified, operative cholangiography may be performed. Operative cholangiography is employed liberally in our institution to detect unsuspected common bile duct stones and to develop experience with transcystic access of the common bile duct. Some investigators have advocated routine cholangiography during laparoscopic cholecystectomy to better define the anatomy of the biliary tree and thereby reduce the risk of significant bile duct injury.4,8, 13,24 Unfortunately, bile duct injuries have occurred despite the performance of intraoperative cholangiography.4, 8, 13, 24 Operative cholangiography should never be considered a substitute for accurate identification of the structures within the hepatocystic triangle. If the anatomy of this region is unclear, the surgeon should abandon the laparoscopic procedure rather than rely on cholangiographic images to guide the operative dissection. Occasionally, the gallbladder joins the common hepatic duct with a short or virtually nonexistent, wide cystic duct. Attempts to ligate a short cystic duct may compromise the lumen of the common bile duct, resulting in a postoperative biliary stricture. The risk of this injury is increased if the bile duct is tented by excessive traction placed on the infundibulum of the gallbladder. If a satisfactory closure of the cystic duct cannot be obtained without compromising the lumen of the bile duct, the procedure should be converted to an open procedure. Attempts to dissect the entire length of the cystic duct to display its union with the common hepatic duct should be avoided. Persistent efforts to display the cystic duct-common duct junction may precipitate bleeding that is difficult to control without risking injury to ductal structures. Occasionally, the cholangiogram may demonstrate a long cystic duct coursing parallel to the common hepatic duct or spirally posterior to the hepatic duct to form a left-sided union. This may falsely lead the surgeon to believe that there is a margin of safety in dissecting and ligating an abnormally long cystic duct. A long cystic duct often is closely adherent to the common hepatic duct, and efforts to dissect its entire length may result in a ductal injury. Figure 7 demonstrates a preoperative endoscopic retrograde cholangiogram (ERC) in a 17-year-old female with suspected gallbladder dysfunction. A long cystic duct is seen coursing posterior to the common hepatic duct to form a left-sided union. A supposedly uneventful laparoscopic cholecystectomy was performed. Unfortunately, the patient became jaundiced in the early postoperative period. A postoperative ERe demon-
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Figure 7. A, Preoperative ERG in a 17-year-old girl with suspected gallbladder dysfunction. Note the presence of a long cystic duct spiraling around to the common hepatic duct to form a left-sided union. B, Postoperative ERG obtained for evaluation of jaundice. The common hepatic duct has been ligated above the low-lying cystic duct insertion. The surgeon apparently assumed that the long cystic duct provided a margin of safety in the dissection and ligation of this structure.
strates a complete ductal transection above the low-lying cystic duct insertion. The cystic artery is usually readily identified within the hepatocystic triangle. The artery should be carefully ligated and divided near its entrance onto the surface of the gallbladder. Occasionally, it is necessary to individually ligate the superficial and deep branches of the cystic artery. An abnormally large "cystic artery" may suggest the presence of a "caterpillar hump" right hepatic artery coursing near the cystic duct and gallbladder infundibulum,z6 If a "caterpillar hump" right hepatic artery is present, it should be carefully dissected away from the gallbladder infundibulum to expose the cystic artery, which usually arises from the angled portion of the hepatic artery. The cystic artery arising from a "caterpillar hump" right hepatic artery is often short and may easily be avulsed if excessive traction is applied to the gallbladder? Hemorrhage in the region of the porta hepatis should be controlled by accurate identification of the bleeding source and precise placement of hemoclips or endo-loops. Maintaining exposure, irrigation of the area, and precise localization of the bleeding source are the most important maneuvers to avoid major complications. The blind application of clips or the use of cautery in an operative field obscured by blood should be avoided.
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Figure 8. Preoperative ERC in a patient with recurrent episodes of cholangitis. Close examination reveals that the right hepatic duct joins the cystic duct rather than the common hepatic duct.
After the cystic duct and cystic artery have been divided, dissection of the gallbladder from the cystic fossa must proceed with caution. An accessory or double cystic artery usually courses in the gallbladder fossa to supply the hepatic surface of the gallbladder. Accessory or aberrant hepatic ducts may pass through the hepatocystic triangle to enter the cystic duct or common hepatic duct (Fig. 8). Careful dissection of this area will enable the surgeon to accurately identify these structures. Cholecystohepatic ducts from the liver may enter the hepatic surface of the gallbladder. These ducts should be ligated to prevent a postoperative biliary leak. SUMMARY
A thorough knowledge of the anatomy of the extrahepatic biliary tree and its frequent anatomic variations is essential for performance of a safe laparoscopic cholecystectomy. The surgeon should have an appreciation for the distortions in the anatomy as a result of retraction on the gallbladder and how the direction of retraction alters the spatial relationships between the cystic duct and common bile duct. The steps in the operative procedure have been outlined to provide good exposure and optimize the identification of structures. Good exposure will enable the surgeon to identify anatomic variants; however, a thorough knowledge of these variants is necessary for safe performance of the operation.
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References 1. Bailey RW, Zucker KA, Flowers JL, et al: Laparoscopic cholecystectomy: Experience with 375 consecutive cases. Ann Surg 214:531-541,1991 2. Baird DR, Wilson JP, Mason EM, et al: An early review of 800 laparoscopic cholecystectomies at a university affiliated community teaching hospital. Am Surg 58:206-210, 1991
3. Benson EA, Page RE: A practical reappraisal of the anatomy of the extrahepatic bile ducts and arteries. Br J Surg 63:853-860, 1976 4. Berd G, Sackier JM, Paz-Partlow M: Routine or selective intraoperative cholangiography during laparoscopic cholecystectomy? Am J Surg 161:355-360, 1991 5. Browne EZ: Variations in origin and course of the hepatic artery and its branches: Importance from surgical viewpoint. Surgery 8:424-425,1940 6. Cushieri A, Dubois F, Mouiel J, et al: The European experience with laparoscopic cholecystectomy. Am J Surg 161:385-387, 1991 7. Davidoff AM, Pappas TN, Murray EA, et al: Mechanisms of major biliary injury during laparoscopic cholecystectomy. Ann Surg 315:196-202,1992 8. Flowers JL, Zucker KA, Graham SM, et al: Laparoscopic cholangiography: Results and indications. Ann Surg 215:209-216,1992 9. Gadacz TR, Talamini MA, Lillemoe KD, et al: Laparoscopic cholecystectomy. Surg Clin North Am 70:1249-1262,1990 10. Ganey JB, Johnson PA, Prilliman PE, McSwain GR: Cholecystectomy: Clinical experience with a large series. Am J Surg 352-357,1986 11. Healey JE, Schroy PC: Anatomy of the biliary ducts within the human liver. Analysis of the prevailing pattern of branchings and the major variations of the biliary ducts. Arch Surg 66:599-616, 1953 12. Hugh TB, Kelly TB: Laparoscopic anatomy of the cystic artery. Am J Surg 163:593-595, 1992 13. Hunter JG: Avoidance of bile duct injury during laparoscopic cholecystectomy. Am J Surg 162:71-76, 1991 14. Johnston EV, Anson DJ: Variations in the formation and vascular relationships of the bile ducts. Surg Gynecol Obstet 94:669-686,1952 15. Larson GM, Vitale GC, Casey J, et al: Multipractice analysis of laparoscopic cholecystectomy in 1,983 patients. Am J Surg 163:221-226, 1992 16. Lillemoe KD, Yeo Talamini MA, et al: Selective cholangiography: Current role in laparoscopic cholecystectomy. Ann Surg 215:669-676, 1992 17. McSherry CK: Cholecystectomy: The gold standard. Am J Surg 158:174-178, 1989 18. Michels NA: The hepatic, cystic and retroduodenal arteries and their relations to the biliary ducts with samples of the entire celiacal blood supply. Ann Surg 133:503-524, 1951 19. Morgenstern L, Wong L, Berd G: Twelve hundred open cholecystectomies before the laparoscopic era. A standard for comparison. Arch Surg 127:400-403, 1992 20. Peters JH, Gibbons GD, Innes JT, et al: Complications of laparoscopic cholecystectomy. Surgery 110:769-778,1991
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21. Pickleman J, Gonzalez RP: The improving results of cholecystectomy. Arch Surg 121:930-934,1986
22. Rocko JM, Swan KG, Di Gioia JM: Calot's triangle revisited. Surg Gynecol Obstet 153:410, 1981 23. Rossi RL, Schirmer WI, Braasch JW, et al: Laparoscopic bile duct injuries: Risk factors, recognition, and repair. Arch Surg 127:596-602, 1992 24. Sackier JM, Berd G, Phillips E, et al: The role of cholangiography in laparoscopic cholecystectomy. Arch Surg 126:1021-1026, 1991 25. Schirmer BD, Edge SB, Dix J, et al: Laparoscopic cholecystectomy: Treatment of choice for symptomatic cholelithiasis. Ann Surg 213:665-677, 1991 26. Scott-Conner CEH, Hall T: Variant arterial anatomy in laparoscopic cholecystectomy. Am J Surg 163:590-592, 1992 27. The Southern Surgeons Club: A prospective analysis of 1,518 laparoscopic cholecystectomies. N Engl J Med 324:1073-1079, 1991 28. Specht MJ: Calot's triangle [letter]. JAMA 200:1186, 1967
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29. Talamini MA, Gadacz TR: Laparoscopic approach to cholecystectomy. Adv Surg 25:118,1992 30. Voyles CR, Petro AB, Meena AI, et al: A practical approach to laparoscopic cholecystectomy. Am J Surg 161:365-370, 1991 31. Wolfe BM, Gardiner BN, Leary BF, Frey CF: Endoscopic cholecystectomy: An analysis of complications. Arch Surg 126:1192-1198, 1991 32. Zucker KA, Bailey RW, Gadacz TR, et al: Laparoscopic guided cholecystectomy. Am J Surg 161:36-44, 1991
Address reprint requests to David W. Crist, MD Department of Surgery The Medical College of Georgia Augusta, GA 30912-4004