Common Bile Duct Exploration – Procedures
What the Anesthesiologist Should Know before the Operative Procedure
Common bile duct procedures may cause problems for many practitioners because of the associated comorbidities. It is not uncommon that these patients present with significant cardiopulmonary issues. What raises the level of acuity is the presence of liver dysfunction and/or concomitant sepsis. Some of the patients will be asymptomatic, but every clinician must be aware of these risks associated with the procedures.
One must do a careful and complete physical examination and pay extra attention to a history that includes jaundice, prior surgeries that may have required blood transfusions, excessive use of alcohol and other recreational drugs, sexual history, as well as presence of pruritus, abdominal distention, weight loss, easy fatigability, and easy bruising after minor trauma. Clinical signs for liver dysfunction should be sought for such as: icterus, ascites, hepatomegaly, splenomegaly, palmar erythema, spider nevi, testicular atrophy and gynecomastia.
If suspicion for liver disease exists, testing for liver function, liver enzymes, coagulation studies, and electrolytes should be performed. While routine liver function tests are not indicated due to low prevalence in most preoperative patients, it is common that patients with biliary disease have already had a full laboratory evaluation.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
In circumstances of biliary obstruction or biliary sepsis there is evidence that surgical intervention must proceed without delay. The clinical information or the lab work may be incomplete, but rapidity in resolving the issue may avoid overwhelming sepsis and worsening liver dysfunction. Most commonly this diagnosis was made after some imaging was performed, whether it was a CT scan, right upper quadrant ultrasound, or endoscopic retrograde cholangiopancreatography (ERCP).
The decision may be to proceed with either urgent/emergency surgical intervention or with ERCP to evacuate a stone or place a stent in a narrowed/strictured biliary tree due to pancreaticobiliary malignancy.
Emergency: Acute emergencies in biliary surgery are relatively uncommon. They mostly include biliary tract sepsis, acalculous cholecystitis with sepsis, or acute biliary tract perforation that may require biliary exploration and/or repair. Coexisting diseases in the setting of an acute inflammatory process are likely to be the major concern for the anesthesiologist. The requirement for invasive monitoring is individualized based on the procedure and the clinical presentation: that is, a septic patient may require invasive monitoring and vasopressor medication and may also need an ICU bed and prolonged intubation as part of the perioperative course.
Another important difference that needs to be taken into account is whether the procedure is being done by a surgeon in the operating room, or requires that the anesthesia team provide patient care in the GI suite and the procedure performed by a gastroenterologist. Unless the patient comes from the ICU and already has a secured airway it can be assumed that there is a “full stomach” risk for pulmonary aspiration. So even if in another circumstance one might consider MAC anesthesia for endoscopy, General anesthesia would be preferred by most clinicians.
Urgent: These are most of the gallbladder surgical procedures that are done while on call. Patients often present with biliary colic and cholethiasis confirmed on ultrasonography or abdominal CT scanning. Blood chemistries often show enzymatic evidence of biliary obstruction plus possible elevated bilirubin levels. If the patient is very unstable or has only sludge and no evidence of biliary tree obstruction a cholecystostomy tube is chosen as a viable alternative; otherwise, laparoscopic cholecystectomy with intraoperative cholangiogram is the usual course for this presentation. As gastrointestinal endoscopists become more and more aggressive, it is likely that the GI suite may replace the operating room for some of these cases.
Elective: This category includes all symptomatic patients with gallstones who require cholecystectomy. Most surgeons today want to provide these as outpatient procedures, but not all patients are good candidates, and evaluation and management should be individualized. Another category of patients are those with chronic pancreatitis or pancreaticobiliary malignancies who may require ERCP and placement of biliary/pancreatic stents in the GI suite. In many institutions, there is the concern that patients for GI endoscopy do not come to the preoperative clinic for medical evaluation and some information may be missed. Whether to administer GETA or MAC is a decision based on indications/contraindications, preference of the provider, and the skills of the gastroenterologist.
A third category are patients with suspected or known pancreaticobiliary malignancy who require either curative or palliative major surgical procedures. These patients often have laparoscopic evaluation prior to the open procedure, whether done in the same setting or not as is the preference of the surgeon. They are evaluated in the preadmission clinic, have all the lab work ready, and often benefit from regional anesthesia for postoperative pain control in addition to general anesthesia. The use of invasive monitoring depends on the planned extent of the surgical procedure and the surgeon’s skills in avoiding large blood losses.
2. Preoperative evaluation
The most important aspects of the medical condition of nonseptic biliary tract patient are the presence and severity of liver dysfunction, along with the expected difficulty of the surgical procedure and the type of anesthetic planned. While coagulopathy is not common with biliary tract disease, its presence is a serious risk factor. Classifications of liver dysfunction have been implemented to aid clinicians with risk assessment (Table I).
|Measure||1 point||2 points||3 points|
|Total bilirubin, μmol/L (mg/dL)||50 (>3)|
|Serum albumin, g/L||>35||28-35||2.20|
|Hepatic encephalopathy||None||Grade I-II (or suppressed with medication)||Grade III-IV (or refractory)|
A. Child-Pugh-Turcotte classification of chronic liver disease
This classification has limitations because it is based on subjective data such as degree of ascites and encephalopathy, which are observer-dependent quantification and was developed before the ultrasound evaluation of ascites was possible.
Chronic liver disease is classified in Child-Pugh Class A to C (Table II) by adding the points from Table I.
|Points||Class||One-year survival||Two-year survival|
Another prognostic model for estimating the severity of liver disease is becoming popular, the Model for End-stage Liver Disease (MELD). Initially developed for patients who underwent elective transjugular intrahepatic portosystemic shunt (TIPS), and shown to be an accurate predictor of survival after this procedure, it is hypothesized that MELD can be used as a prognostic tool for broader range of liver disease and severity.
Briefly, an increasing MELD score is associated with an increased severity of liver dysfunction and 3-month mortality risk. Due to its accuracy for predicting short-term survival it has been used especially by the transplant community. Due to its predictive value, the MELD system has now been expanded beyond the transplant patient and applied to a larger variety of patients with liver disease like patients undergoing TIPS, patients with alcoholic hepatitis, hepatorenal syndrome, cirrhosis with sepsis unrelated to spontaneous bacterial peritonitis, acute variceal hemorrhage, and, relevant here, for assessment of surgical mortality risk in liver disease.
The initial MELD score model took into consideration the etiology of the liver disease whether cholestatic or alcoholic or due to other etiologies.
The original formula used is: 3.8[Ln serum bilirubin (mg/dl)] + 11.2[Ln INR] +9.6[Ln serum creatinine (mg/dl)] + 6.4[etiology: 0 if cholestatic or alcoholic, 1 if other etiologies], where Ln is the natural logarithm. There are several calculators available online slightly different for various etiologies. As far as the tool utilized for determining the risk of postoperative mortality after major surgical procedures including gastrointestinal, orthopedic, and cardiac surgery there is an online calculator that takes into consideration the etiology of liver dysfunction and therefore it resembles the initial MELD formula, and can be found at: www.mayoclinic.org/meld/mayomodel9.html
It has been suggested that patients with a MELD score below 10 can undergo elective surgery, those with a score between 10 and 15 may undergo elective surgery with caution, and patients with MELD score above 15 should not have elective surgery.
The current MELD used by the United Network for Organ Sharing (UNOS) with the goal in prioritizing allocation of donor organs for liver transplantation is different in terms of not including the etiology of liver dysfunction:
C. Measures of hepatic function
Measures have been proposed including dynamic tests of liver function; unfortunately, they do not seem to provide additional prognostic information when compared to Child-Pugh classification.
The APACHE score can predict survival in patients admitted to the ICU, but they are not specifically evaluated for patients with cirrhosis undergoing surgery.
Elective or semi-urgent procedures should not be performed in patients with acute or fulminant hepatitis, alcoholic hepatitis, severe chronic hepatitis, Child class C or MELD >15 cirrhosis, severe coagulopathy, or severe extrahepatic manifestations of liver dysfunction such as hypoxia, cardiomyopathy, or acute renal failure. Elective procedures are well tolerated in patients with Child’s class A or MELD
Biliary tree injuries. See text for descriptions of types of injuries.
Type A includes injuries that involve leakage into the gallbladder bed from either minor hepatic ducts or cystic duct without loss in continuity of the biliary tree. Types B and C are occlusions (Type B), and transection (Type C) injuries of aberrant right hepatic ducts, and are frequently are associated with injuries to right hepatic artery. Type D present as lateral damage to common bile duct resulting in bile leak. Type E injuries are subclassified according to the level of injury of the biliary tree into five subtypes. These patients present years after cholecystectomy with jaundice and require surgical repair via hepaticojejunostomy.
In general complications after laparoscopic cholecystectomy are due to patient selection, surgical inexperience, and technical constraints of the minimally invasive procedures. If biliary injuries are recognized at the time of surgery a T-tube drainage of the common bile duct is indicated and primary repair is contraindicated due to higher rates of breakdown or strictures. Major biliary leaks present within 2 to 10 days after cholecystectomy with fever, abdominal pain, and/or bilious ascites, mild jaundice, leukocytosis, abnormal liver function tests, and mildly elevated bilirubin.
ERCP is an important diagnostic tool, and also can be followed by stent placement or even sphincterotomy to allowing free flow of bile. If symptoms improve, the stent can be either removed or replaced in 2 to 4 weeks’ time, although most will require hepaticojejunostomy. For patients who continue to have severe abdominal pain or peritonitis or progressive intra-abdominal sepsis, operative exploration with wash-out may be needed. Occlusive injury to the right hepatic lobe results in atrophy of the right lobe, which ultimately requires hepaticojejunostomy with possible segmental liver resection if atrophy is significant. There are multiple types of operative procedures to correct a bile duct injury, a Roux-en-Y bypass being the most commonly used.
ERCP (endoscopic retrograde cholangiopancreatography)
ERCP is a procedure performed routinely in the GI suite initially developed as a nonsurgical approach for diseases of pancreaticobiliary system. The purpose is either diagnostic for biliary or sphincter of Oddi pathology or therapeutic when stents are placed to aid with bile drainage in either benign strictures or malignancies of hepatobiliary system.
For this procedure patients need to be prone with the head turned toward the endoscopist. The decision to provide MAC vs. GETA is dependent upon the anesthesiologist’s preference, patient’s coexisting diseases, and the endoscopist’s experience. It seems that anesthesiologists that work with the same team for many of these cases feel more comfortable in providing MAC anesthesia. On the other hand when most of these procedures are performed with nursing sedation and the anesthesia team is called for a very complicated case, general anesthesia is the expectation. If MAC is the desired anesthetic good topical anesthesia of the hypopharynx should be done by the endoscopist. A minimal anesthetic may be ideal for sicker patients; nevertheless, it is more cumbersome to provide MAC in a prone patient. Small doses of medications such as fentanyl with only modest boluses of propofol while the probe is inserted can be used; infusions of remifentanyl or dexmedetomidine may also be used. Most important is the avoidance of apnea in a prone patient since mask ventilation or insertion of a LMA may be very challenging. Some of these patients come repeatedly for stent revisions, and are therefore well known to the anesthesia teams.
The advantage of MAC is rapid turnover and fast track toward discharge home, but it requires a cooperative patient. Disadvantages are obvious, first related to difficulty in maintaining a patent airway if large doses of sedation are being administered, prolonged procedure duration if the anesthetic is inadequate, and imperfect relaxation with limited tolerance for very long procedures.
Post-ERCP complications include cholangitis, cholecystitis, and pancreatic sepsis. The most important risk factor for developing cholangitis is failed endoscopic drainage, in which case antibiotic treatment may be indicated, because subsequently patients may develop fever, right upper quadrant pain, and jaundice. If adequate drainage cannot be achieved, percutaneous or surgical decompressive procedures should be promptly performed.
Gastric reduction surgeries are now considered an established treatment for bariatric patients. There are several types, including biliopancreatic diversion (BPD). BPD is considered a malabsorptive procedure and, due to its side effects that include both macro- and micronutrient deficiencies, can be followed by significant complications, some of which can be life-threatening. Another point of interest is that some surgeons perform cholecystectomy at the time of gastric bypass procedures. This is obviously associated with different risk factors due to preexisting diseases, including morbid obesity.
Whipple procedure also known as pancreaticoduodenectomy is a major surgical procedure utilized for treatment of cancers of head of pancreas, common bile duct, duodenum near the pancreas, or duodenal papilla; it consists of resection of gastric antrum, first and second portion of duodenum, head of the pancreas, common bile duct and gallbladder. Since radiographic studies like CT scan may underestimate subtle aspects of the disease, some surgeons elect to perform a laparoscopic examination prior to this procedure, either in the same setting or at a different time, and biopsy lymph nodes, liver or peritoneum that might look suspicious for cancer; the goal is to select only the candidates with localized disease that are amenable to surgical resection.
A pylorus-sparing pancreaticoduodenectomy has recently emerged and appears to be more popular especially in Europe. It seems that this newer technique offers the benefit of shorter surgical time and required less blood transfusion when compared to the classic Whipple, but there seem to be no difference in morbidity, hospital mortality, and postoperative complications between them. (See Pancreaticoduodenectomy chapter.)Common Bile Duct Exploration – Procedures What the Anesthesiologist Should Know before the Operative Procedure Common bile duct procedures may cause problems for many practitioners because of
Laparoscopic Common Bile Duct Exploration
Choledocholithiasis can be treated by either open, laparoscopic, percutaneous, or endoscopic means (Endoscopic Retrograde Cholangiopancreatography [ERCP]). In experienced hands, the laparoscopic common bile duct exploration is a potential option for managing stones within the biliary tree at the same time as laparoscopic cholecystectomy.
Patients should be given prophyaxis for deep venous thrombosis (subcutaneous heparin or low-molecular-weight heparin perioperatively, as well as sequential compression devices intraoperatively) and prophylactic antibiotics, usually or first generation cephalosporin.
The procedure is performed with the patient in the supine position, with the surgeon on the patient’s right and the assistant on the left. Care must be taken to assure that the operating bed is positioned such that a fluoroscopic C-arm can be positioned for imaging in the patient’s right upper quadrant. Incorrect bed position can result in significant intraoperative delays and unnecessary risk to the patient when re-maneuvering the bed is required.
Normally, the laparoscopic monitors are placed at the patient’s head to the left and right. All equipment, including equipment necessary for common bile duct exploration and an open surgical tray on stand-by, should be confirmed prior to the patient being brought into the room.
Port placement can be identical to that for laparoscopic cholecystectomy, whether or not cholecystectomy is being performed at the same time. A 10-12 mm infra-umbilical trocar is initially placed with either an open cut-down technique, optical trocar, pre-insufflation with a Veress needle followed by trocar placedment or optical trocar placement. A 5 or 10/12 mm port is placed inferior to the xyphoid process under direct camera-visualization, to the right of the falciform ligament, and two 5 mm placed inferior to the right subcostal margin in the anterior axillary line and in the midclavicular line. Care should be taken not to injure the superior epigastric vessles when placing the midclavicular port.
Cholangiogram and common bile duct exploration
There are two different approaches to performing laparoscopic common bile duct exploration: transcystic and through a choledochotomy.
The cystic duct is exposed for 2-3 cm and scissors used to incise it. A cholangiogram catheter is then introduced. If it has a balloon tip, this can be inflated, and 50% contrast injected under fluoroscopy to confirm position and anatomy. The common bile duct can be flushed with 30 cc of saline via the catheter. Small stones may be flushed this way, especially with administration of 1 mg of glucagon to allow relaxation of the Sphinctor of Oddi. If flushing is inadequate to clear any small stones, fluoroscopic-guided basket retrieval can be performed, or a 4 Fr Fogarty balloon can be inserted through the cystic duct, inflated, and withdrawn to pull stones into the intra-abdominal cavity to be retrieved. Alternatively, or for more difficult stones, the cystic duct orifice can be dilated in preparation for choledochoscopy. A guide wire is first passed into the common duct transcystically and an 8 Fr angioplasty balloon used to dilate the orifice. A 12 Fr introducer catheter is placed for repeated passage of the choledochoscope.
Through the choledochoscope a retrieval basket can be inserted under direct visualization. Laser ablation of stones has also been described. In either case, pressurized saline through a side working port of the scope facilitates clearance of small stones and particulate matter.
Alternatively, the above methods can be performed through a choledochotomy. The common bile duct is exposed and a vertical ductomy performed for about 5 mm on the anterior surface of the duct, distal to the cystic-common bile duct junction. The techniques for stone clearance are identical to the trans-cystic approach. The choledochotomy can be managed with a T-tube which is sutured in place with absorbable suture, primary closure over a stent (for later removal by ERCP), or primary closure alone.
If a T-tube was placed, removal can occur 4 weeks postoperatively when the tract to the skin is epithelialized. Usually, a cholangiogram is performed through the T-tube first to assure adequate clearance of the ductal system. When the transcystic approach is used, no special care is required other than routine postoperative care.Laparoscopic Common Bile Duct Exploration Choledocholithiasis can be treated by either open, laparoscopic, percutaneous, or endoscopic means (Endoscopic Retrograde Cholangiopancreatography ]]>