点击显示 收起
美国胃肠和内镜外科医生学会2005年会热点
Highlights of The Society of American Gastrointestinal and Endoscopic Surgeons 2005 Annual Meeting
2005年4月13－16日
美国佛罗里达州
April 13-16, 2005; Ft. Lauderdale, Florida
Timothy Kuwada, MD
Forum on Biliary Injuries
The introduction of laparoscopic cholecystectomy (LC) in the late 1980s ushered in the era of minimally invasive general surgery. Since then, it has become the preferred approach for cholecystectomy. During the initial years of LC, when surgeons were in the "learning curve" of the procedure, there was a significant increase in bile duct injuries (BDIs) compared with open cholecystectomy. However, most surgeons are now past their learning curve, and many consider LC to be a "basic" laparoscopic procedure. Nevertheless, with the current incidence of BDIs as high as 1.4%,[1,2] these injuries continue to be very morbid complications that have significant legal and financial implications.
This year, The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in conjunction with the American Hepato-Pancreato-Biliary Association (AHPBA) and the Society for Surgery of the Alimentary Tract (SSAT) presented a "Forum on Biliary Injuries." A panel of international experts reviewed the avoidance, recognition, and management of LC-associated BDIs. The session was moderated by Nathaniel Soper, MD, Professor of Surgery, Feinberg School of Medicine Northwestern University, Chicago, Illinois, and W. Scott Helton, MD, Professor of Surgery, University of Illinois at Chicago.
Lygia Stewart, MD, Associate Professor of Surgery, University of California, San Francisco, addressed the cognitive psychological issues that lead to human error and BDIs during LC. A combination of altered lighting, tunnel vision, and a lack of 3-dimensional vision and haptic feedback can create an optical illusion during LC. If this occurs, the surgeon may mistakenly believe that he or she has correctly identified the cystic duct. This leads to an "active mistake," with the surgeon intentionally dividing a duct rather than accidentally cutting or cauterizing it. Proper lighting and laparoscopic equipment, including the use of angled laparoscopes and minimizing blood in the field, help to reduce the risk of visual miscues.
There is a potential for surgeons to talk themselves out of the presence of ductal injury, despite abnormal findings during LC. According to Dr. Stewart, less than 25% of BDIs are recognized during laparoscopy, and even after conversion to an open procedure, 20% of injuries are missed. Furthermore, Dr. Stewart reported that studies have demonstrated that it takes at least 4 abnormal cues before the intraoperative recognition of BDIs approaches 100%. She also discussed the concept of "conformational bias," whereby once a surgeon has made a decision (correct or incorrect), he or she tends to favor any information that supports this initial decision and discounts findings (abnormal anatomy or an intraoperative cholangiogram ) that may indicate a BDI.[3] Surgeons must be aware of these psychological issues and be especially vigilant during the key steps of LC. Any abnormal findings or anatomy must be clarified prior to dividing any ductal structure during LC.
William Traverso, MD, Professor of Surgery, Virginia Mason Medical Center, Seattle, Washington, discussed the role of an IOC in preventing BDIs, and he reviewed the critical steps of intrepreting an IOC. On an AP view, the ductal structures found on an IOC form a "sigmoid curve." The upper portion of the curve is the left hepatic duct; the midportion is the common hepatic duct (CHD); and the bottom or distal part of the curve is the common bile duct (CBD). These structures are highly constant and should be identified on all IOCs (see Figure 1).
Figure 1.Intraoperative cholangiogram showing the "sigmoid curve."
However, the insertion and position of the cystic duct and right hepatic duct(s) are variable, with a 12% incidence of anomalies. This may explain why a disproportionate number of major injuries occur on the right vs the left ductal system. On a standard AP view, the cystic duct usually enters the right side of the distal CHD (left side of monitor) at an angle of approximately 45°. However, the cystic duct may enter the anterior or left side (right side of monitor) of the extrahepatic ducts. The cystic duct may also parallel the extrahepatic ducts prior to insertion. This places the mid- and proximal regions of the cystic duct closer to the extrahepatic ducts, increasing the risk of BDI during dissection of the cystic duct. In approximately 2% of patients, the cystic duct joins an aberrant right hepatic duct, which may appear to be a continuation of the distal cystic duct, thus placing it at risk of injury. This aberrant right duct may be a segmental branch or the main right duct. If a segmental branch is divided and clipped (Strasberg type B injury), it will atrophy and the patient may remain asymptomatic. On the other hand, if the main right duct is divided and clipped (Strasberg type E injury), the drainage from the right lobe is obstructed and jaundice, cholangitis, or both is more likely to occur.
Complete evaluation of the ductal anatomy with IOC requires visualization of the entire extrahepatic ductal system and bifurcation of the right and left intrahepatic ducts. If the CHD and bifurcation are not visualized, the tip of the cholangiocatheter may be positioned in the CBD. Pulling the catheter back should remedy this problem. If this maneuver fails to identify the CHD and bifurcation, the surgeon should convert to an open approach.
The controversial issue of routine vs selective IOC was also raised. Dr. Traverso noted that the ability of IOC to prevent and identify BDIs is dependent on the surgeon's capacity to correctly interpret the IOC. He reviewed several studies that concluded that routine IOC reduces both the incidence of BDIs and time to diagnosis.[4,5] It was argued that routine IOC may improve interpretive skills and increase the sensitivity of detecting subtle ductal anomalies.
Mark Callery, MD, Associate Professor of Surgery, University of Massachusetts Medical School, Worcester, reviewed the Strasberg Classification of BDIs (see Figure 2), the causes and risk factors for BDIs, and operative techniques for reducing BDIs.[6] He echoed Dr. Stewart's point that most major BDIs are a result of misidentification of ductal structures. Technical complications, such as thermal injury, tenting of the ducts, and dissecting too deeply, are less frequent causes of BDIs. Surgeon inexperience, acute inflammation, cystic duct impaction, excessive bleeding, and aberrant anatomy are all risk factors for BDIs.
Figure 2.Strasberg classification of laparoscopic injuries to the biliary tract. Type A injuries originate from small bile ducts that are entered in the liver bed or from the cystic duct. Type B and Type C injuries are frequently involved in the aberrant right hepatic duct. Type A, C, D, and some E injuries may cause bilomas or fistulas. Type B and other Type E injuries occlude the biliary tree and bilomas do not occur.
Dr. Callery stressed the importance of several operative techniques to reduce the risk of BDIs. Proper gallbladder retraction during LC is critical in achieving exposure to the cystic duct. This retraction consists of cephalad and slight lateral retraction of the gallbladder fundus and lateral retraction of the gallbladder infundibulum. This maneuver places the cystic duct in a more perpendicular position relative to the CHD/CBD and moves the proximal and mid-cystic duct farther from these critical structures, thereby reducing the chance of misidentification and accidental injury. Conversely, cephalad retraction of the infundibulum places the cystic duct and gallbladder parallel, and closer, to the main extrahepatic ducts, which increases the risk of injury.
The concept of the critical view of safety was also emphasized. With the gallbladder retracted (as described above), the "critical view" is achieved by dissecting along the inferior and medial aspect of the gallbladder between the liver bed and gallbladder/cystic duct junction. Dissecting along the gallbladder edge of Calot's triangle reduces the risk of drifting medially toward the main ducts. Ultimately, a large window in Calot's triangle (the critical view) is formed, and the only 2 structures entering the gallbladder should be the cystic duct and cystic artery. No structures (duct or artery) should be clipped or divided prior to achieving the critical view.
Keith Lillemoe, Chairman and Professor of Surgery, Indiana University, Bloomington, Indiana, discussed the recognition and management of BDIs. According to Dr. Lillemoe, approximately 75% of patients with a BDI will have a delayed presentation ranging from days to months. He reviewed the variety of imaging options for the postcholecystectomy patient who presents with pain, fever, or jaundice. Ultrasound and computed tomography (CT) are both good modalities for assessing fluid collections and bile duct dilatation, and can provide guidance for percutaneous drainage. A hepatobiliary iminodiacetic acid (HIDA) scan can compliment the evaluation by determining whether there is complete ductal obstruction, leakage of bile, or both. Once a BDI is diagnosed, initial management includes control of sepsis with antibiotics, decompression of the biliary system with a percutaneous transhepatic catheter (PTC) or endoscopic retrograde cholangiopancreatography (ERCP), and percutaneous drainage of a biloma/bile leak. After the patient is stabilized, the BDI and biliary anatomy must be completely defined. Although ERCP is the gold standard for cholangiography, PTC is often required to define the anatomy proximal to the injury. Alternatively, magnetic resonance cholangiopancreatography (MRCP) has evolved into an excellent biliary imaging modality that can rival the detail of direct cholangiography (PTC or ERCP), with negligible morbidity.
If an injury is recognized intraoperatively, it is vital to stay calm and seek appropriate help. A complete transaction of a major duct should be repaired with a Roux-en-Y hepaticojejunostomy. A primary duct-to-duct anastomosis in this setting has an unacceptably high leak and stricture rate. However, a small lateral ductal laceration can sometimes be closed primarily over a T-tube. If a surgeon is not comfortable with biliary reconstruction, he or she should minimize the dissection, place drains, and transfer the patient to an appropriate center.
Miguel Angel Mercado, MD, National Institute of Medical Sciences and Nutrition, Mexico City, Mexico, reviewed the optimal timing and technique of bile duct repair. The advantages of delaying (> 3 months) the repair of a BDI include the following:
Conversely, early repair (< 3 months) of a ductal injury offers the following advantages:
Regardless of the timing of repair, predictors of a "good" outcome include a tension-free anastomosis to a healthy duct and preservation of the bifurcation. Dr. Mercado reviewed data from his series of BDI repairs and made several conclusions. First, enteric anastomosis to higher, more proximal regions of the extrahepatic duct have a lower stricture rate. Second, when "all things are equal," BDIs should be repaired early. Finally, success rates for repair of BDIs can exceed 90%.
The forum concluded with Eduardo de Santibanes, MD, PhD, of Buenos Aires, Argentina. Dr. de Santibanes discussed the management of biliary-enteric stenosis following bile duct repair. Anastomotic stenosis leading to lobar atrophy can be asymptomatic. However, it can yield major morbidity in the form of jaundice, cholangitis, portal hypertension, secondary biliary cirrhosis, and end-stage liver failure. The first line of therapy for anastomotic stenosis is percutaneous biliary dilatation. In a large series reported from The Johns Hopkins University, Baltimore, Maryland, 58.8% of patients who presented with anastomotic stenosis after bile duct repair were successfully treated with dilatation.[7] Arterial supply to the affected region of the bile duct should also be assessed with hepatic angiography prior to any intervention. Patients who fail dilatation should be considered for revision of their hepaticojejunostomy. In Dr. de Santibanes series, 5% of the patients went on to liver transplantation. Indications for transplant included failed revision and/or dilation of the hepaticojejunostomy and one of the following: (1) intractable ascites, (2) repeated cholangitis, and (3) worsening jaundice.
Although infrequent, BDIs during LC are associated with high morbidity, cost, and litigation.
Despite abnormal visual and cholangiographic cues, many BDIs are unrecognized at the original operation.
The panel strongly recommended routine IOC, although there was some disagreement as to whether it should be considered the standard of care.
The right ductal system and cystic duct have the highest anatomic variability and should be routinely identified on IOC as they enter the constant sigmoid curve.
Techniques for avoiding BDIs include lateral retraction of the infundibulum and establishing the "critical view of safety" prior to dividing any ductal structure.
Major BDIs should be repaired with biliary-enteric drainage (hepaticojejunostomy). Anastomotic strictures can be treated with percutaneous dilation. Strictures that fail dilation can yield significant morbidity in the form of secondary biliary cirrhosis.