The classic anatomy of the biliary tree is present in only 30% of individuals, so it may be said that anomalies are the rule, not the exception. As with any procedure, the knowledge of normal anatomy and common variants is critical to the success of surgical intervention. The cystic duct may join the CBD at an acute angle, travel parallel to the common duct for several centimeters prior to insertion, insert into the right hepatic duct, or be congenitally absent. The cystic artery usually arises from the right hepatic artery, but one must be absolutely sure that the cystic artery is visualized entering the gallbladder wall. Occasionally the right hepatic artery will loop up onto the surface of the gallbladder, and a very short cystic artery will arise. Furthermore, there can often be a posterior cystic artery, which can easily be injured if not recognized. The common bile duct begins at the junction of the cystic duct and the common hepatic duct and passes inferiorly to the ampulla of Vater. Its normal diameter is less than 6 mm, although it may be larger in elderly patients and those with biliary obstruction.
It is important to clearly identify the structures within the hepatocystic triangle, which is the ventral aspect of the area bounded by the gallbladder wall and cystic duct, the liver edge, and the common hepatic duct. Contained within the hepatocystic triangle is the eponymic Calot's triangle: The boundaries of Calot's triangle include the cystic duct, cystic artery, and the gallbladder wall. Aberrant anatomy is a well-recognized risk factor for biliary injury. An aberrant right hepatic duct (RHD) is the most common anomaly causing problems during laparoscopic cholecystectomies. The most dangerous variant is when the cystic duct joins a low-lying aberrant right sectoral duct. Injuries to these ducts are under-reported since occlusion of an aberrant duct may be asymptomatic and even unrecognized (Fig. 48-1).
Biliary anatomy variations. A. Normal anatomy. B. Cystic duct insertion on right hepatic duct. C. Anterior or posterior spiral insertion of cystic duct. D, E, and F. Common variants of accessory right hepatic duct (RHD).
As with any abdominal operation, patients are fasted for a minimum of 8 hours prior to the operation. Patients without major comorbidities are generally scheduled as outpatient procedures. Prophylactic antibiotics are up to the surgeon's discretion; evidence suggests that most patients have a very low risk of perioperative infection.37 Antiembolic stockings and sequential compression devices are placed on both legs to avoid pooling of blood in the lower extremities by the reverse Trendelenburg position generally used during this operation. Following induction of general endotracheal anesthesia, an orogastric tube may be placed to decompress the stomach. The abdomen is shaved and prepared in standard sterile fashion with particular care taken to rid the umbilicus of all debris.
Most surgeons utilize two video monitors, one on each side of the operating table to facilitate visualization by both surgeon and assistant. Using the American technique, the surgeon stands to the left of the patient, the first assistant stands to the patient's right (Fig. 48-2). If a laparoscopic video camera operator is used, he stands to the left of the surgeon. In the French technique, the patient's legs are abducted and the surgeon stands between the legs.
A working space, provided by a pneumoperitoneum, is essential for the surgeon to see and to operate within the abdominal cavity. CO2 has the advantage of being noncombustible and rapidly absorbed from the peritoneal cavity. It may, however, lead to hypercarbia in patients with significant cardiopulmonary disease.38 The most common location for initial peritoneal entry is at the midline near the umbilicus. Supraumbilical or infraumbilical incisions may be made in vertical, horizontal, or curvilinear orientations based on surgeon's preference. Pneumoperitoneum can be established by either a closed or an open technique. In the closed technique, CO2 is insufflated into the peritoneal cavity through a Veress needle, which is subsequently replaced with a laparoscopic port, placed blindly into the abdominal cavity. In the open technique, a laparoscopic port is inserted under direct vision into the peritoneal cavity via a small incision; only after ensuring definitive and safe peritoneal entry is the pneumoperitoneum established. There are advantages and disadvantages to both techniques. Surgeons performing laparoscopic cholecystectomy should learn both and use them selectively based on the patient's body habitus and previous surgical history.
Port Placement and Exposure
Depending on the surgeon's preference, a 5- or 10-mm laparoscope is inserted into the abdomen through the periumbilical port and the abdominal cavity is visually explored. It is generally advantageous to use an angled (30- or 45-degree) laparoscope rather than a 0-degree scope, because the angled scopes enable obtaining multiple views of the same operative field. The patient is then placed in a reverse Trendelenburg position of 30 degrees while rotating the table to the left by 15 degrees. This maneuver allows the colon and duodenum to fall away from the liver edge. The falciform ligament and both lobes of the liver are examined closely for abnormalities. The gallbladder can usually be seen protruding beyond the edge of the liver.
Two small accessory subcostal ports are then placed under direct vision. The first 5-mm trocar is placed along the right anterior axillary line between the 12th rib and the iliac crest. A second 5-mm port is inserted in the right subcostal area in the midclavicular line. Grasping forceps are placed through these two ports to secure the gallbladder. The assistant manipulates the lateral grasping forceps, which are used to grasp the fundus and elevate the liver. The fourth working port is then inserted through an incision in the midline of the epigastrium (Fig. 48-3). This trocar is usually inserted approximately 5 cm below the xiphoid process, but the precise position and angle depends on the location of the gallbladder as well as the size of the medial segment of the left lobe of the liver. Dissecting forceps are then inserted and directed toward the gallbladder neck. One should note that the orientation of the laparoscope is generally parallel to that of the cystic duct when the fundus is elevated, whereas the instruments placed through the other three ports enter the abdomen at right angles to this plane. The surgeon uses a dissecting forceps to raise a serosal fold of the most dependent portion of the fundus. The assistant's heavy grasping forceps are then locked onto this fold using either a spring or ratchet device. With these axillary grasping forceps, the fundus of the gallbladder is then pushed in a lateral and cephalad direction, rolling the entire right lobe of the liver cranially.
This maneuver is complicated in patients with a fixed, cirrhotic liver or a heavy, friable liver because of fatty infiltration. In patients with few adhesions to the gallbladder, pushing the fundus cephalad exposes the entire gallbladder, cystic duct, and porta hepatis. Most patients, however, have adhesions between the gallbladder and the omentum, hepatic flexure and/or duodenum. These adhesions are generally avascular and may be lysed bluntly by grasping them with dissecting forceps at their site of attachment to the gallbladder wall and gently stripping them down toward the infundibulum. Extreme caution should be taken to avoid damage to surrounding structures. Use of electrocautery may accidentally damage the unvisualized CBD or proximally located duodenum. After exposing the infundibulum, blunt grasping forceps held in the surgeon's left hand and placed through the midclavicular trocar are used to grasp and place traction on the neck of the gallbladder.
The infundibulum is grasped, placing traction on the gallbladder in a lateral direction to distract the cystic duct from the CBD (Fig. 48-4). Fine-tipped dissecting forceps (Maryland) are used to dissect away the overlying fibroareolar structures from the infundibulum of the gallbladder. The dissection should begin from a known structure, for example, the gallbladder, rather than in an unknown area, to avoid damage to the underlying structures such as a bile duct or hepatic artery. The dissection initially commences 4 or 5 cm proximal to the neck of the gallbladder and proceeds distally, such that a modified “top-down” technique is employed. The objective of the initial dissection is to free the gallbladder from its bed such that there is a window beneath it through which the liver substance can be seen. The hepatocystic triangle is maximally opened and converted into a trapezoid shape by retracting the infundibulum of the gallbladder inferiorly and laterally while maintaining the fundus under traction in a superior and medial direction. A lymph node usually lies on the surface of the cystic artery, and occasionally it is necessary to use a brief application of low-wattage electrosurgical coagulation to obtain hemostasis as the lymph node is bluntly swept away. To expose the reverse of Calot's triangle, the infundibulum of the gallbladder is pulled in a superior and medial direction. The use of an angled laparoscope facilitates viewing both sides of the hepatocystic triangle when used in combination with these retraction techniques. After clearing the structures from the apex of the triangle, the junction between the infundibulum and the origin of the proximal cystic duct can be tentatively identified. The strands of peritoneal, lymphatic, and neurovascular tissue are stripped away from the cystic duct to clear a segment from the surrounding tissue. Curved dissecting forceps are helpful in creating a window around the posterior aspect of the cystic duct to skeletonize the duct itself. Alternatively, the tip of the hook cautery can be used to encircle and expose the duct. It is generally unnecessary and potentially harmful to dissect the cystic duct down to its junction with the CBD. The cystic artery is separated from the surrounding tissue by similar blunt dissection at this time. If the cystic artery crosses anterior to the duct, the artery may require dissection and division prior to approaching the cystic duct. The neck of the gallbladder is thus dissected away from its liver bed, leaving a large window at its base through which the liver parenchyma is visualized. There should be two, and only two, structures (the cystic duct and artery) crossing this window—this is the “critical view of safety,” which should be demonstrated prior to clipping or cutting any tubular structures.38 To reiterate, no structure should be divided until the cystic duct and cystic artery are unequivocally identified. Developing this critical view of safety is an essential step to minimize the chance of bile duct injury during laparoscopic cholecystectomy (Fig. 48-5).38
Retraction of the gallbladder.
Intraoperative Evaluation for Choledocholithiasis
After initially dissecting the proximal cystic duct, the CBD should be imaged if there is any concern for choledocholithiasis or questions regarding the biliary anatomy. This can be achieved by intraoperative cholangiography (IOC) or intracorporeal laparoscopic ultrasonography (LUS). Prior to either procedure, a clip is applied high on the cystic duct at its junction with the gallbladder to prevent stones migrating down the duct during subsequent manipulation. To perform IOC, the anterolateral wall of the cystic duct is incised and dissecting forceps are used to gently compress the cystic duct systematically back toward the gallbladder, thereby milking stones away from the CBD and out of the ductotomy. A 4F or 5F catheter is inserted into the duct through a hollow, 5-mm metal tube that has an appropriate gasket to prevent carbon dioxide leakage around the catheter itself. The cholangiography catheter is inserted into the cystic duct and a clip is applied loosely to secure the catheter in place. If the introducer has grasping jaws, it can be used to secure the catheter into the duct. Alternatively, catheters equipped with balloons proximal to the tip may be used for fixation. Cholangiography can be performed by either real-time fluoroscopy (dynamic) or by obtaining two standard radiographs (static) after injecting 5 and 10 mL of water-soluble contrast medium. The films should be inspected for the following: (1) the length of cystic duct and location of its junction with the CBD, (2) the diameter of the CBD, (3) the presence of luminal filling defects within the CBD, (4) free flow of contrast into the duodenum, and (5) anatomy of the extrahepatic and intrahepatic biliary tree. After the cholangiocatheter is removed, the cystic duct is doubly clipped below the ductotomy with care to avoid the wall of the CBD, and then divided. The posterior jaw of the clip applier must be visualized prior to applying each clip in order to avoid injuring the surrounding structures. Great care should be taken so that the CBD is not tented up into the clip. If the cystic duct is particularly large or friable, it may be preferable to replace one of the clips with a suture, either hand-tied or a preformed loop with slip knot.
Evaluation of the CBD by LUS is an alternative to cholangiography. Several studies39,40 performed at open cholecystectomy reported intracorporeal ultrasonography to be more accurate than operative cholangiography in assessing the CBD for stones (97–99% vs 89–94%).41–43 However, few surgeons adopted ultrasound for this purpose. Recently, LUS has been used in several centers during laparoscopic cholecystectomy and is gaining popularity.43–47 With LUS, the transducer has a higher frequency with improved resolution compared to those used with transabdominal ultrasonography. In experienced hands, LUS appears to be as accurate as cholangiography for demonstrating choledocholithiasis but can be performed more rapidly.48 In a recent prospective multicenter trial with 209 laparoscopic cholecystectomy patients, the time to perform LUS (7 ± 3 minutes) was significantly less than that of IOC (13 ± 6 minutes).48 The study showed that LUS was more sensitive for detecting stones but that IOC was better in delineating intrahepatic anatomy and defining anatomical anomalies of the ductal system. The authors concluded that the two methods of duct imaging were complementary. Despite these promising data, more clinical experience will be necessary to establish the appropriate role of LUS for the detection of choledocholithiasis during laparoscopic cholecystectomy.49,50
Completion of Cholecystectomy
The cystic duct is clipped using an endoscopic clip applier and divided using scissors. Two clips are placed proximally on the cystic duct and one clip is placed toward the gallbladder (Fig. 48-6). For cystic ducts that are large or friable, a preformed endoloop is preferable for ligating the distal cystic duct. After the duct is divided, the cystic artery is dissected from the surrounding tissue for an adequate distance to permit placement of three clips. The surgeon must determine that the structure is indeed the cystic artery and not the right hepatic artery looping up onto the neck of the gallbladder or an accessory or replaced right hepatic artery. After an appropriate length of cystic artery has been dissected free, it is clipped proximally and distally prior to transection (Fig. 48-7). Electrocautery should not be used for this division, as the current may be transmitted to the proximal clips leading to subsequent necrosis and hemorrhage.
Clipping the cystic duct.
Clipping the cystic artery.
The ligated stumps of the cystic duct and the artery are then examined to ensure that there is no leakage of either bile or blood and that the clips are placed securely and compress the entire lumen of the structures without impinging on adjacent tissues. A suction-irrigation catheter is used to remove any debris or blood that has accumulated during the dissection. Separation of the gallbladder away from its hepatic bed is then initiated using an electrosurgical probe to coagulate small vessels and lymphatics. While maintaining cephalad traction on the fundus of the gallbladder with the axillary forceps, the midclavicular forceps pulls the neck of the gallbladder anterosuperiorly and then alternatively medially and laterally to expose and place the tissue connecting the gallbladder to its fossa under tension. An electrocautery spatula or hook is used to coagulate and divide the tissue. Intermittent blunt dissection will facilitate exposure of the proper plane (Fig. 48-8).
Dissecting the gallbladder off the liver.
Dissection of the gallbladder fossa continues from the infundibulum to the fundus, progressively moving the midclavicular grasping forceps cephalad to allow maximal countertraction. The dissection proceeds until the gallbladder is attached by only a thin bridge of tissue. At this point, prior to completely detaching the gallbladder, the hepatic fossa and porta hepatis are once again inspected for hemostasis and bile leakage. Small bleeding points are coagulated and the right upper quadrant is liberally irrigated and then aspirated dry while checking for any residual bleeding or bile leakage. The final attachments of the gallbladder are divided, and the liver edge is again examined for hemostasis.
After the cholecystectomy has been performed, the gallbladder must be removed from the abdominal cavity. The gallbladder may be placed within an entrapment sac prior to extracting it through the abdominal wall (Fig. 48-9). This is recommended particularly if the gallbladder has been perforated intraoperatively or if the specimen is large. If the stone burden is small, the gallbladder can be extracted at the subxiphoid port site. Usually, the gallbladder is most easily removed at the umbilical port site where there are no muscle layers anterior to the fascial plane. Also, if the fascial opening needs to be enlarged because of large or numerous stones, extension of the umbilical incision causes less postoperative pain and has better cosmesis than does enlarging the subxiphoid incision. The laparoscope is removed from the umbilical port and placed through the epigastric port. Large “claw” grasping forceps are introduced through the umbilical port to grasp the infundibulum of the gallbladder. The forceps, trocar, and gallbladder neck are then retracted as a unit through the umbilical incision. The neck of the gallbladder is thus exteriorized through the anterior abdominal wall with the fundus remaining within the abdominal cavity. If the gallbladder is not distended with bile or stones, it can be simply withdrawn with gentle traction. In many cases, a suction catheter introduced through an incision in the gallbladder neck is used to aspirate bile and small stones. Stone forceps can also be placed into the gallbladder to extract or crush calculi if necessary. Occasionally, the fascial incision must be extended to extract larger stones or thick-walled gallbladders.
Placing gallbladder in entrapment bag.
Each incision is infiltrated with bupivacaine for postoperative analgesia. The fascia of the umbilical incision is closed with one or two large absorbable sutures in an interrupted or figure-of-eight fashion. Closure of the subxiphoid fascia is optional, as visceral herniation is unlikely to occur because of the oblique entry angle of the trocar into the abdominal cavity and its location anterior to the falciform ligament. The skin of the subxiphoid and umbilical incisions is closed with subcuticular absorbable sutures. The skin incisions at both 5-mm port sites can be closed with absorbable sutures, adhesive strips, or skin closure adhesives. The orogastric tube is removed in the operating room, and the patient is transferred to the postanesthesia care unit. Patients are allowed out of bed as soon as they are fit enough to walk, and more than 90% of patients are discharged from the hospital within 24 hours. Fit patients who have been preoperatively selected may be safely discharged within 6 hours following surgery.45 Patients are evaluated 1 week following surgery and if sutures are present, they are removed. At this time, more than 95% of patients are back to a normal routine and most return to work immediately following their clinic visit.