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General Surgery
Extrahepatic Biliary Tract and Gallbladder
Built from Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery
What’s inside
11 sections · 196 slides
Overview
- Scope of this topic
Embryogenesis and normal development
- Distal part of the hepatic diverticulum is credited with forming the extrahepatic duct system End of 4th week: cystic duct and gallbladder primordium have appeared Beginning of 5th week: common bile duct and hepatic ducts become visible Solid stage of the ducts occupies the 5th week; ducts elongate to reach the forming liver Slow recanalisation of the ducts runs from about the 6th through the 12th week
- Developmental sequence of the biliary primordium
- Human fetal gallbladder contractility has been reported in the second half of pregnancy Its physiological role in fetal life is unknown Gallstones are among the fetal gallbladder anomalies that have been reported
- Sites of potential biliary tract malformation
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder (continued)
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder (continued)
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder (continued)
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder (continued)
- Anatomic and Surgical History of the Extrahepatic Biliary Tract and Gallbladder (continued)
Variations and anomalies of the gallbladder
- Anomalies of the Extrahepatic Biliary Ducts and the Gallbladder
- Anomalies of the Extrahepatic Biliary Ducts and the Gallbladder (continued)
- Absence and vestigial forms of the gallbladder
- Familial occurrence of absent gallbladder has been suggested Ultrasonography now detects absence in people who have no gallbladder disease Preoperative cholangiography plus laparoscopic exploration and laparoscopic sonography is recommended If imaging fails to visualise the gallbladder, laparoscopy should precede laparotomy
- A double gallbladder was found at autopsy by Blasius in 1674; first recorded in a living patient in 1911 A review covered 297 reports of double and eight of triple gallbladder; 142 were adequately described Triple gallbladders may share one cystic duct, have three separate ducts, or two share and one separate The anomalies form a continuous spectrum, from an internal longitudinal septum to widely separated organs Six basic types are recognised: three in the split primordium group, three in the accessory group
- Double gallbladder arising from a split primordium
- Accessory gallbladder types
- Reported more often in women than men, 1.7 to 1, though true incidence is probably nearer equal The disparity is attributed to the greater incidence of gallbladder disease in women Both organs are usually diseased when intimately connected, less often when separation is complete Ultrasound is the best test and is useful in both the healthy and the diseased state Oral or intravenous cholecystography previously failed to detect duplication in 60% of cases Nuclear scan may show it, but cystic duct obstruction will hide one or both organs
- Left-sided gallbladder lies under the left lobe; the cystic duct enters the common bile duct from the left No functional disorder is associated with it, but the radiologist must be alert to it on ultrasound Intrahepatic gallbladder is submerged in the liver and mimics absence; CT or ultrasound may be the only clue A high rate of lithiasis is associated with the intrahepatic gallbladder The mobile gallbladder hangs on a mesentery and is liable to torsion and strangulation
Vascular anomalies of the portal system
- A portal vein entering the inferior vena cava was first publicly described in 1793 It is perhaps the result of persisting supracardinal veins It is an anomaly of the formation of the vena cava rather than of portal vein development The condition is compatible with life
- Described in 1921 in a patient whose portal vein crossed the duodenum anteriorly Thirteen further cases were recorded in the next forty years The original patient had no symptoms, but duodenal compression has resulted from such a vein The vein lies in front of the duodenum, exactly where a surgeon expects to divide tissue
- Embryonic origin of the preduodenal portal vein
- Failure of the portal vein to bifurcate has been reported, with emphasis on its surgical significance Congenital absence of the portal vein is very rare: intestinal and splenic blood drains to the vena cava Absent portal flow may cause nodular regenerative hyperplasia of the liver
- Pulmonary veins that pierce the diaphragm and enter the portal system are found occasionally At least 37 cases have been reported; they form about 15% of all anomalous pulmonary venous drainage The result is a left-to-right shunt, usually compensated by a right-to-left shunt through a patent foramen ovale Cause: failure of the pulmonary vein to tap the pulmonary plexus, with a persisting splanchnic connection in the fifth week Successful correction by anastomosing the pulmonary channel to the left atrium has been reported
Variations and anomalies of the biliary ducts
- Congenital biliary atresia is the most serious malformation of the biliary tract A short segment, an entire duct, or the whole system may be atretic, in any combination The atretic duct may be hypoplastic, stenosed, or reduced to a fibrous band easily overlooked Surgery is the only treatment; the actual procedure is decided in the operating room
- Patterns of biliary atresia and their correctability
- If a liver has formed from the hepatic primordium, agenesis of non-cystic structures is hard to imagine The hepatic and common hepatic ducts have therefore formed, even if in a greatly reduced state Even when no remnant can be identified, no true agenesis of these ducts has occurred Biliary ductular atresias are divided into three groups; three explanations for atresia have been offered
- Surgery is the only treatment for children with extrahepatic biliary atresia A modification of hepatic portoenterostomy, the Kasai operation, used a Cavitron ultrasonic suction aspirator Persistent biliary drainage resulted in 77% of the cases treated with that modification
- A local balloon-shaped or cylindrical enlargement of the common bile duct is probably congenital Symptoms of obstruction are the result of the dilatation rather than its cause Several explanations for the dilatation have been offered; none seems adequate First classified in 1959 into three types; modified in 1984 into the five types in common use
- Todani classification of choledochal cysts
- Choledochocele
- Adults with anomalous junction of the pancreaticobiliary ductal system have a high incidence of gallbladder cancer Prophylactic cholecystectomy is recommended even when no malignant lesion is found in the gallbladder Gallbladder carcinoma has been reported with maljunction and no biliary dilatation at all Some advise resecting the extrahepatic biliary tract, not cholecystectomy alone, to prevent bile duct carcinoma Maljunction without a cyst may need only cholecystectomy; maljunction with a cyst requires cyst excision
- Most common in adult females complaining of biliary symptoms or pancreatitis In infants a right upper quadrant mass with pain and jaundice suggests a choledochal cyst The classic triad of pain, jaundice and palpable mass is often absent in ductular dilatation Diagnosis is established by ultrasonography, CT scan and cholangiography Sonography, ERCP and iminodiacetic acid scanning make the diagnosis straightforward
- Maljunction outside the sphincter of Oddi without dilatation is an important risk factor for gallbladder carcinoma Some favourable outcomes have been reported for gallbladder carcinoma associated with maljunction A counter-view holds gallbladder carcinoma to be an age-dependent malignancy, mostly in females That view links it instead to long-term benign gallstone disease Several questions about the origin of choledochal cysts remain unanswered
- Variations in the union of the hepatic ducts
- Accessory hepatic ducts
- Variations of the common bile duct
- Duplication of the common hepatic duct
- Duplications of the common bile duct
- Duplications of the cystic duct
- Absent and atretic cystic duct
- An anomaly or variation must be recognised as such when it is encountered The surgeon should never attempt to explain abnormal findings as normal Some variants may be more prone to lithiasis than the normal configuration This is especially critical in laparoscopic surgery and reinforces the importance of cholangiography
Blood vessels of the porta hepatis
- The extrahepatic triad consists of the hepatic artery, hepatic portal vein and hepatic duct The three run together in the free edge of the hepatoduodenal ligament The hepatic artery supplies 25% of the afferent blood to the liver and about 50% of its oxygen The hepatic arterial supply is derived from the celiac trunk in 55% of subjects In the other 45% the common, right or left hepatic artery arises elsewhere: aberrant hepatic arteries
- Origin and branches of the celiac trunk
- Division of the celiac trunk
- Variations of the hepatic artery
- The artery may divide into right and left branches anywhere between the hilum and its own origin The gastroduodenal artery always arises at the transition of mobile and fixed segments of the first duodenum Its origin is therefore determined by whichever hepatic vessel passes that fixed point If a normal common hepatic artery bifurcates very early, medial to the portal vein, the right branch passes behind the vein Those pulsations can be palpated through the hiatus of Winslow
- It runs horizontally along the upper border of the head of the pancreas It then turns upward to ascend between the layers of the lesser omentum Peritoneum of the posterior wall of the omental bursa covers the horizontal portion The hepatoduodenal ligament envelops the ascending portion The ascending portion lies in front of the epiploic foramen, left of the common bile duct, anterior to the portal vein
- Aberrant hepatic arteries occur in roughly 41-46% of subjects across four large studies An artery arising entirely outside the celiac distribution is called replacing; it may supply a whole lobe An atypical artery additive to a normal celiac branch is often called accessory Truly accessory arteries scarcely exist: they provide the primary supply to a lobe, segment or subsegment Almost every accessory hepatic artery exposed surgically should be treated as essential to liver survival
- Patterns of aberrant hepatic artery origin
- Course of an aberrant right hepatic artery from the superior mesenteric artery
- Aberrant hepatic branches were found in 46% of preparations A right aberrant branch in 24%, a left in 30%, and both in 8% The distinction between accessory and replaced branches is very difficult to make during surgery An aberrant left branch always arises from the left gastric artery and runs in the cranial lesser omentum It is endangered during gastrectomy and hiatal hernia repair; it enters the liver through the fissure of the venous ligament
- Arterial patterns were catalogued in 1000 donor livers used for transplantation A right hepatic artery from the superior mesenteric artery may pass through the pancreatic head Knowing that before pancreatectomy or hemihepatectomy is of great value A left hepatic artery from the left gastric allows rapid dissection of the porta hepatis in hemihepatectomy Ligation or embolisation for trauma, tumour, aneurysm or haemobilia requires detailed angiographic analysis
- The portal vein provides 75% of the blood and about 50% of the oxygen reaching the liver It is formed behind the neck of the pancreas by the confluence of superior mesenteric and splenic veins Towards the liver it lies in front of the inferior vena cava, duct to its right, proper hepatic artery to its left It is 7-10 cm long, 0.8-1.4 cm in diameter, and has no valves At the porta hepatis it bifurcates into right and left portal veins
- Portal vein and its major tributaries
- Portal venous supply of the liver
- Participation of the Inferior Mesenteric Vein in the Formation of the Hepatic Portal Vein
- The inferior mesenteric vein ends with approximately equal frequency in splenic, superior mesenteric or portal vein In 17 of 23 dissected subjects the left gastric vein entered the portal vein; in six it entered the splenic vein A portal termination of the left gastric vein was observed in 83% of another series Where drainage was into the portal vein, the left gastric vein lay in the hepatogastric ligament
- The liver is drained by dorsal hepatic veins opening into the inferior vena cava at the upper hilum There are three major veins, right, middle and left, and from 10 to 50 smaller veins The extrahepatic length of the three major veins varies from 0.5 cm to 1.5 cm The right hepatic vein is the largest; it lies in the right segmental fissure It drains the entire posterior segment and the superior area of the anterior segment of the right lobe
- The middle hepatic vein lies in the main lobar fissure It drains the inferior area of the anterior segment of the right lobe and the inferior medial segment of the left The left hepatic vein lies in the upper part of the left segmental fissure It drains the superior area of the medial segment and all of the lateral segment In about 60% of people left and middle veins unite and enter the cava as a single trunk 1-2 cm long
- A common trunk of the left and middle veins was found in 70 of 83 autopsies One centimetre of vein without tributaries was judged sufficient for successful ligation By that standard the right vein could have been ligated in 60% of cadavers examined The middle and left veins could have been ligated in only 11% Between 5 and 10 of the small veins will require ligation during hepatic resection
- A significant segment of the right hepatic vein may course retrohepatically There it is vulnerable to posterior incisions at the level of the 12th rib The left hepatic vein may be torn during operations at the gastro-oesophageal junction when the left triangular ligament is incised One or two constant veins drain the caudate lobe into the left side of the inferior vena cava Muscular and collagenous fibres at the vein-cava junction may act as a sphincter-like formation
Extrahepatic ducts and the gallbladder
- Bile canaliculi arise within the hepatic lobules Canaliculi empty into the canals of Hering in the interlobular triads Canals of Hering are collected into ducts draining the hepatic areas Area ducts form the four hepatic segment ducts Outside the liver the segment ducts form the right and left hepatic ducts
- Biliary drainage from lobule to duodenum
- Formed by the union of the anterior and posterior segment ducts at the porta hepatis That pattern was present in 72% of specimens examined In the remainder the posterior, or rarely the anterior, segment duct crosses the fissure to the left system In those cases the right hepatic duct is absent The average length of the right hepatic duct, when present, is 0.9 cm
- Variations in the tributaries of the right hepatic duct
- Left hepatic duct
- Sites of drainage of the medial segment duct
- Formed by the union of the right and left hepatic ducts at the transverse fissure of the liver Its lower end is defined as its junction with the cystic duct The distance between those two points varies from 1.0 cm to 7.5 cm The diameter of the duct is about 0.4 cm Several arteries lie in relation to it, many of them anterior to the duct
- Location of the common hepatic duct
- Segments of the Biliary Tract and the Frequency of Arteries Lying Anterior to Them
- Segments of the Biliary Tract and the Frequency of Arteries Lying Anterior to Them (continued)
- The cystic duct contains 5 to 12 crescent-shaped mucosal folds, the spiral valve of Heister Similar folds are seen in the neck of the gallbladder Secretion pressure of the cystic duct mucous glands exceeds the secretion pressure of bile Prolonged obstruction proximal to the cystic duct produces white bile, composed only of mucus The ridges of the valve, with the constriction at the neck, obstruct instruments and gallstones
- The cystic duct joins the hepatic duct at about 40 degrees in 64-75% of individuals In 17-23% it runs parallel to the hepatic duct and may even enter the duodenum separately That separate entry is called absence of the common bile duct In 8-13% the cystic duct passes below or above the hepatic duct to enter it on the left side In the parallel type the common duct is at risk from a surgeon attempting to ligate the cystic duct
- Variations of the cystic duct
- A long remnant can cause postcholecystectomy symptoms, sometimes severe It acts as a site of chronic inflammation, lithiasis or neuroma formation Rarely it kinks the common bile duct or causes reflex spasm of Oddi Re-exploration and excision is indicated only after thorough study and if symptoms disable the patient A remnant found long or diseased at reoperation on the biliary tree or pancreas must be excised Prevention: meticulous dissection and ligation 2-3 mm from the junction with the common bile duct
- The gallbladder is 7-10 cm long with a capacity of 30-50 ml It lies on the visceral surface of the liver in a shallow fossa The fossa marks the plane dividing the right lobe from the medial segment of the left lobe: the GB-IVC line That is the junction of the quadrate lobe, segment IV, and the right lobe, along the line of Rex Glisson's capsule separates the gallbladder from the liver; anteriorly its peritoneum is continuous with the liver's
- Divisions of the gallbladder
- Usually located at the angle of the ninth costal cartilage with the right border of the rectus sheath It lies to the left of the hepatic flexure of the colon It is completely covered by peritoneum because it projects beyond the lower border of the liver Partial folding of the fundus produces the Phrygian cap deformity in 2-6% of gallbladders The deformity may or may not be visible from outside; many radiographic cases show defective fundal musculature
- Phrygian cap and Hartmann's pouch
- The body contacts the first and second portions of the duodenum and occupies the gallbladder fossa It is also related to the transverse colon Only with a mesentery, the wandering gallbladder, is the body completely covered by peritoneum That mesentery is the prerequisite for acute torsion
- Peritoneal folds from the gallbladder
- The narrow neck curves up and forward, then sharply back and downward in an S to become the cystic duct A constriction is said to mark the junction of neck and cystic duct The cystic artery lies here in the loose connective tissue attaching the neck to the liver The mucosa of the neck forms a spiral ridge, not to be confused with the valve of Heister in the duct The neck lies in the free border of the hepatoduodenal ligament
- After cholecystectomy bile sometimes leaks from small ducts in the gallbladder bed Whether these hepatocystic ducts enter the gallbladder itself is disputed In 500 carefully dissected specimens no such communicating ducts were found Branches from the right hepatic duct were found in the bed but did not communicate with the gallbladder One view holds minute canaliculi drain hepatic parenchyma into the gallbladder; another calls them post-inflammatory artefacts
Common bile duct and the choledochoduodenal junction
- It begins at the union of the cystic and common hepatic ducts It ends at the papilla of Vater in the second part of the duodenum Length varies from 5 cm to 15 cm depending on where the ductal union lies In 22% the common hepatic and cystic ducts run parallel for an average of 17 mm before uniting The average diameter is about 6 mm
- Four portions of the common bile duct
- Supraduodenal portion and its arterial relations
- It lies between the superior margin of the first duodenum and the superior margin of the pancreatic head It is 1-3.5 cm long and may be free or partially fixed to the duodenum The gastroduodenal artery lies to its left The posterior superior pancreaticoduodenal artery lies anterior to the duct The middle colic artery lies anterior to the duct and to the other arteries
- In 35 specimens four types of relationship between gastroduodenal artery and duct were described Type 1, 22 cases: the two structures separate progressively, artery to the left of the duct Type 2, 7 cases: they approach each other without crossing Type 3, 5 cases: the artery crosses in front of the duct at the level of the first duodenum Type 4, 1 case: the artery crosses below D1 and runs along the duct's right border The pancreaticoduodenal artery originated at the posterior face of D1 in 20% and crossed in front of the duct
- Acquired absence of the cystic duct may follow an impacted gallstone in Hartmann's pouch The inflammatory process obliterates the duct, and this may occur with some frequency The surgeon must therefore be extremely careful to avoid injuring the common bile duct A problem remains where the cystic duct is congenitally absent or obliterated by inflammation
- It runs from the upper margin of the head of the pancreas to the point of entry into the duodenum It passes downward and to the right, posterior to the pancreas or within the pancreatic parenchyma Five patterns of the relation of duct to pancreas were described from 200 specimens A prepancreatic common bile duct is rare: seven cases were found among 550 bodies One case is recorded in which the duct was completely extrapancreatic and near the renal vein
- Relation of the common bile duct to the pancreas
- The intramural portion takes an oblique path averaging 1.5 cm through the duodenal wall There it receives the main pancreatic duct inferiorly The two ducts usually lie side by side with a common adventitia for several millimetres The diameter of both ducts decreases within the duodenal wall The septum between the ducts is reduced to a thin mucosal membrane before they become confluent
- Choledochoduodenal junction and the sphincter
- In the embryo the main pancreatic duct arises as a branch of the common bile duct As the duodenum grows it absorbs the proximal bile duct up to its junction with the pancreatic duct Minimal resorption leaves a long ampulla with a high or even extramural junction Increased resorption shortens the ampulla; maximum resorption gives separate orifices for the two ducts A long common channel exceeding 15 mm carries a higher incidence of gallbladder or bile duct carcinoma
- Variations of the ductal opening into the duodenum
- Duplication of the common bile duct with ectopic openings
- It was suggested that a stone impacted at the papilla with a long ampulla lets bile reflux into the pancreatic duct That common channel theory was supported and later revived by several workers One critic observed that pancreatic secretory pressure is usually higher than hepatic secretory pressure Reflux pancreatitis is real, but how often it arises from ampullary obstruction remains controversial Anomalous junction of pancreaticobiliary ducts is regarded as an anatomic factor inducing pancreatitis
- Endoscopic nasobiliary drainage was reported to prevent progression from mild to severe acute pancreatitis A thin tube is inserted into the bile duct with the help of a duodenoscope Gallstones leave the common pancreaticobiliary channel Bile then drains directly to the exterior instead of into the duodenum The tube curves in a U-shaped course around the ampulla and is thought to pull it and relieve obstruction
- Endoscopic nasobiliary drainage
- Endoscopic nasobiliary drainage
- Endoscopic nasobiliary drainage
- Endoscopic nasobiliary drainage
Vessels, lymphatics, innervation and histology
- The cystic artery usually arises from the right hepatic artery within the hepatocystic triangle It runs to the right of the common hepatic duct The lymph node of Calot usually lies just superficial to it and is a good guide to finding it Reaching the gallbladder behind the common hepatic duct, it divides into anterior superficial and posterior deep branches The branches anastomose and send arterial twigs to the adjacent liver Remember that in about one third of cases the right hepatic artery arises from the superior mesenteric artery
- Variations of the origin of the cystic artery
- Origin of the Cystic Artery
- A cystic artery arising to the right of the ducts from the right hepatic branch lies in the triangle between hepatic and cystic ducts A second cystic artery arising to the left of the ducts usually runs anterior to the bile ducts If the posterior pancreaticoduodenal arcade arises from a normal gastroduodenal artery it lies in front of the ductus choledochus If that arcade arises from a vessel behind the pancreatic head it also passes behind the choledochus Both facts matter during choledochotomy and pancreaticoduodenectomy
- Normal position of the cystic artery
- Double cystic artery
- Large cystic artery with an aberrant right hepatic artery
- Cystic artery arising from the gastroduodenal artery
- Cystic artery arising from the left hepatic artery
- The right hepatic artery is the commonest origin of the cystic artery at 76.6% Calot's triangle is bounded by the common hepatic duct, the cystic duct and the cystic artery 86.1% of all cystic arteries coursed through the triangle 100% of those arising from the right hepatic artery ran through it, but only 54% of those from other hepatic origins None arising from gastroduodenal, celiac, superior mesenteric or superior pancreaticoduodenal arteries passed through it Of right hepatic origin arteries, 72.7% ran beneath the common hepatic duct as they entered the triangle
- The ducts are supplied from the cystic artery above and the posterior superior pancreaticoduodenal artery below The upper supply from the cystic artery is relatively constant The lower supply may come from the hepatic, gastroduodenal or supraduodenal arteries The epicholedochal arterial plexus of the common bile duct derives from the retroduodenal or pancreaticoduodenal arteries Collateral circulation is enhanced by two intramural plexuses
- Epicholedochal arterial plexus
- Retroduodenal and retroportal arteries seen from behind
- Arterial supply of the extrahepatic biliary tract
- Venous drainage of the gallbladder
- Long collecting trunks drain the lymphatic plexus of the fundus and body Trunks run on the right and left borders of the gallbladder, joined by an oblique trunk, forming a large N Left-sided trunks drain to the cystic node in the angle between cystic and common hepatic ducts Right-sided trunks follow the cystic duct without entering the cystic node These and the efferents of the cystic node reach the hiatal node and the superior pancreaticoduodenal nodes There is no drainage upward into the liver
- Intrahepatic and extrahepatic lymphatic drainage
- Nodal drainage of the gallbladder wall
- Lymph nodes around the pancreatic head and hepatoduodenal ligament
- Lymphatic spread by site of bile duct carcinoma
- Parasympathetic vagal and visceral sensory fibres come from the hepatic division of the anterior vagal trunk and from the celiac division of the posterior vagal trunk, following the hepatic artery and its branches Preganglionic sympathetics and pain afferents reach the celiac plexus by the greater thoracic splanchnic nerves Fibres synapse in the celiac ganglia; postganglionic and sensory fibres run in the hepatic plexuses Fibres from the right phrenic nerve reach the gallbladder via phrenic, celiac and hepatic plexuses Many are afferent and explain pain referred to the right hypochondrium and between the shoulder blades
- Three nerve plexuses are demonstrable: subserous, muscular and mucosal Ganglion cells decrease in number from subserous to mucosal levels Compared with the myenteric plexus of the gut, subserous plexus ganglia are larger and spaced further apart Despite this well-developed nerve supply there are relatively few smooth muscle cells in the ducts A distinct nerve to the sphincter of the common bile duct was found in 92% of cases studied
- The bile ducts have an external fibrous layer, a few thin smooth muscle layers and a columnar mucosa The smooth muscle layers run longitudinal, oblique and circular True ducts of Luschka open into the cystic duct They lie in the connective tissue between the neck of the gallbladder and the liver They open into the lumen of the cystic duct, not that of the gallbladder Histologically they resemble intrahepatic bile ducts and may be remnants of aberrant embryonic ducts
- Layers of the gallbladder wall
- The mucosa has very tall, slender columnar epithelial cells No glands are present, although the elaborate folds give the first impression of glands The folds form deep diverticula of the mucosa identified as Rokitansky-Aschoff sinuses In some cases these extend through the muscularis externa Bacteria accumulate in these folds and chronic inflammation may develop
- Between 250 ml and 1500 ml of bile enters the duodenum each day The gallbladder holds 15 to 60 ml, on average about 35 ml It concentrates bile by absorbing sodium, chloride, bicarbonate and water, concentrating bile salts 5 to 250 times Potassium is concentrated as water is absorbed; further concentration follows by simple diffusion The epithelium secretes hydrogen ions, converting carbonate to bicarbonate, so calcium carbonate does not precipitate Cholecystokinin contracts the gallbladder and inhibits the sphincter of Oddi; vagal stimulation also contracts it
- The hepatocystic triangle is bounded by the gallbladder and cystic duct on the right and the common hepatic duct on the left Its upper boundary is the margin of the right lobe of the liver The triangle originally described by Calot had the cystic artery as its upper boundary The area included in the triangle has therefore enlarged over the years The area of Moosman is a circular area 30 mm in diameter fitting into the hepatocystic duct angle
- Boundaries and contents of the hepatocystic triangle
- An aberrant right hepatic artery was present in 18% of specimens In 83% of those the aberrant artery gave rise to the cystic artery within the triangle The cystic artery is found in the triangle in 96% of individuals In 80% the origin of the artery from a normal or aberrant right hepatic artery lies within the triangle Among 220 cadavers the cystic artery was double in 50 and triple in one 85% of all variations in the hepatic pedicle occur in Moosman's area, and half of these are potentially hazardous
- Structures at risk in the hepatocystic triangle
Surgery of the extrahepatic biliary tract
- Inspect and palpate the liver first Place the patient in reverse Trendelenburg so the viscera descend Gallstones can be felt because they lie in the most dependent position Palpating the hepatic triad and lesser omentum may reveal enlarged nodes and large stones in the common duct Tumours of the porta hepatis or pancreatic head are found by careful palpation Remember that obstruction can be present without dilatation of the duct
- Kocherisation of the duodenum is necessary to palpate the distal common bile duct Mobilise the hepatic flexure of the colon and incise the peritoneum lateral to the second part of the duodenum Insert the left index and middle fingers posteriorly with the thumb positioned anteriorly The common duct and any stone or tumour can then be palpated The duodenum and head of the pancreas can be evaluated at the same time
- the Anatomy of Differential Diagnosis in the Operating Room
- the Anatomy of Differential Diagnosis in the Operating Room (continued)
- Routinely the anterior leaf of the hepatoduodenal ligament is incised over the hepatocystic triangle Where adhesions from inflammation or previous surgery obscure relationships, greater effort is required A profusely bleeding gallbladder bed is managed with suction and diathermy The bed may be filled with omentum and a drain placed over the omentum, not between bed and omentum Subserous excision uses the lamina propria of loose connective tissue as the plane of dissection That plane removes the entire mucosa and leaves the liver surface uninjured
- Many surgeons begin in the hepatocystic triangle, identifying, ligating and transecting cystic artery and duct first The gallbladder is then dissected from its bed from below upward The alternative begins at the fundus and dissects downward towards the neck Fundus-first may reduce blood loss if branches of the cystic artery and veins are clamped or cauterised early Beware a small branch of the cystic artery to the cystic duct, which bleeds if avulsed Early ligation of the cystic duct keeps stones from descending into the common duct
- The junction of the cystic and common hepatic ducts should be identified regardless of the direction of dissection A short cystic duct may cause inadvertent injury to the common bile duct A long cystic duct remnant may produce the cystic duct remnant syndrome That syndrome resembles gallbladder disease secondary to lithiasis Percutaneous cholecystostomy or gallbladder drainage is safe and effective in acute cholecystitis It allows a delayed laparoscopic cholecystectomy once inflammation has settled
- Bouveret's syndrome is gastric outlet or duodenal obstruction by a giant gallstone, in 1-3% of cholecystoenteric fistulas Routine subhepatic drainage lengthens hospital stay and raises fever and complication rates Drainage should be used only where contamination, haemorrhage, bile leak or inflammation are present Timing matters: draining too early fails to solve the problem, too late risks systemic infection Extensive hepatic resection is recommended where gallbladder cancer invades the liver at the fossa Radical surgery is urged for T2 gallbladder carcinoma; nodal or perineural invasion argues for further treatment
- Patients with asymptomatic cholelithiasis may have elective cholecystectomy, a safe procedure with low morbidity and mortality Some patients are at high risk of complications from asymptomatic disease and surgery is then difficult Intraoperative ultrasonography and frozen section help assess the depth of invasion of gallbladder carcinoma Older male patients over 50 with cardiovascular disease and leucocytosis above 17,000 per mL with acute cholecystitis have increased risk of gallbladder gangrene and conversion to open surgery
- The first laparoscopic cholecystectomy was performed in Germany on 12 September 1985, looking through the scope without video A piece of bicycle tubing served as the large cannula through which the gallbladder was removed The surgeon's licence was revoked shortly afterwards The technique was reintroduced to the profession in 1988 Since then it has become the treatment of choice for symptomatic gallstones It is described as safe and valid for acute cholecystitis with a low rate of complications
- Algorithm for the management of acute cholecystitis
- The widespread adoption of laparoscopy did not worsen survival in patients with gallbladder cancer Laparoscopic manipulation of a cancerous gallbladder is not a proximate cause of the poor prognosis Laparoscopic common bile duct exploration is safe, applicable and cost-effective for choledocholithiasis Laparoscopic cholecystectomy is the procedure of choice for gallstones in infants and children Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of haemorrhage Those branches should be identified preoperatively with ultrasound
- Although the duct dilates with obstruction, there is no sharp dividing line between normal and obstructed ducts Mobilising the distal duct from the undersurface of the pancreas gained 2-5 cm of length The pancreas and duodenum should be mobilised because the duct may be intrapancreatic In about 70% the duct is free on the pancreatic surface or covered by a tongue leaving a cleavage plane End-to-end anastomosis is avoided in favour of Roux-en-Y hepatico- or choledochojejunostomy That avoidance is now standard practice in virtually all bile duct reconstructions
- Absence of multifocality, diploid tumours and a negative proximal margin predict long-term survival in proximal duct carcinoma Curative resection is achievable in about one third of patients with cholangiocarcinoma and should be the goal Survival improves in resectable patients who undergo removal of all gross disease Palliative surgical treatment also showed a survival advantage over non-operative therapy Hepp-Couinaud hepaticojejunostomy without stenting is reliable for postcholecystectomy stricture Because proximal strictures cannot reliably be called benign or malignant, they should be presumed malignant
- Solvents such as chenodeoxycholic and ursodeoxycholic acid have no primary indication for duct stones They may be considered in a small group for whom invasive or surgical treatment is risky or likely to fail Acute cholangitis and pancreatitis from duct stones need systemic antibiotics and early stone removal by ERCP and sphincterotomy Endoscopic sphincterotomy followed by interval laparoscopic cholecystectomy is safe for gallstone cholangitis Leaving the gallbladder in situ after sphincterotomy increases the risk of further biliary symptoms Side-to-side choledochoduodenostomy with a wide stoma is safe in selected patients, with about 5% complications
- Laparoscopic cholangiography is safe, quick, and detects common bile duct stones Open choledochostomy retains a definite place alongside ERCP, papillotomy and laparoscopic exploration Residual stones were effectively treated by the percutaneous route through a T-tube track in 373 patients Endoscopic papillary balloon dilatation is an alternative to papillotomy for small stones, pending further study Laparoscopic duct exploration provides all-in-one treatment and avoids preoperative ERCP in most patients
- Surgical options for choledochal cysts
- Cyst excision with Roux-en-Y hepaticojejunostomy
- Portal hypertension is an increase in resistance to portal flow, usually secondary to cirrhosis It may also follow splenic vein thrombosis Collateral circulation develops between the portal and systemic venous networks Submucosal varices develop in the proximal stomach and distal oesophagus Haematemesis, ascites, hypersplenism and encephalopathy may follow Spontaneous splenorenal shunts occur in about 17% of cases
- Collateral circulation in isolated splenic vein occlusion
- Selective distal splenorenal shunt
- Mesorenal interposition shunt
Anatomic complications and bile duct injury
- Percutaneous transhepatic cholangiography: haemorrhage, bile peritonitis and septicaemia are the chief dangers ERCP: cholangitis, duodenal perforation, pancreatitis, pancreatic sepsis and pseudocyst formation The endoscope may injure the common bile duct, main pancreatic duct or duodenal papilla Angiography may worsen ongoing gastrointestinal bleeding or existing renal or hepatic insufficiency Contrast medium should not exceed 1 g of iodine per kilogram of body weight Peritoneoscopy gave 12 major complications in 2400 procedures, 0.5%; other series report up to 2.5%
- About 500,000 operations for biliary tract disease are performed annually in the United States Nearly 10,000 deaths result from complications or treatment of diseases of the biliary system Many of these deaths follow surgery in elderly patients with comorbid conditions The hazards of cholecystectomy, common bile duct surgery and sphincteroplasty are broadly the same The anatomic complications of laparoscopic cholecystectomy are similar to those of open removal
- The chief danger is haemorrhage from the many large vessels lying anterior to the biliary tree These vessels are inconstant in number and location The posterior superior pancreaticoduodenal artery, anterior to the retroduodenal duct, is met most frequently Injury to the portal vein or the inferior vena cava is serious and must be repaired at once Bleeding from veins of the gallbladder bed or of the common bile duct is a minor complication Ischaemia of the liver may follow unintended ligation of a right hepatic or aberrant right hepatic artery
- Interference with the blood supply of the common bile duct may cause ischaemia and stricture Some surgeons hold that the supply is good and collateral circulation prevents local ischaemia Work on fetal and neonatal specimens concluded the duct should not be skeletonised for more than 2 cm That limit applies despite an apparently abundant blood supply The combination of ischaemia and bile leakage is a long-recognised danger
- Jaundice, biliary fistula and bile peritonitis with pain and fever follow iatrogenic ductal injury A small insidious bile leak is more dangerous than leakage from an obviously divided major duct Small ducts in the gallbladder bed and small accessory hepatic ducts are easily overlooked and cut Loosening of the cystic duct stump ligature is a possible source of postoperative bile peritonitis The duct may be injured by passing a probe without a preoperative cholangiogram Fixation from disease or adhesion from prior surgery may cause unexpected sharp angulation
- Mechanisms of iatrogenic biliary injury
- Bismuth classification of postoperative biliary strictures
- Major bile duct injuries and postoperative strictures remain a considerable surgical challenge Management begins with preoperative cholangiography to delineate the anatomy Percutaneous biliary catheters are then placed Surgical reconstruction with a Roux-en-Y hepaticojejunostomy follows That sequence is associated with a successful outcome in up to 98% of patients Efforts to mobilise the distal duct may injure the pancreas; retraction may tear the liver
- Common bile duct injury was less than 0.2% with the open method Bile duct injuries with laparoscopy were 0.58% in 1284 operations from 1989 to 1991 and 0.50% in 1143 operations from 1992 to 1994 An individual surgeon had a 1.7% injury rate in the first 15-20 laparoscopic cholecystectomies That rate fell to 0.17% after 50 operations The chance of injury remains greater in laparoscopic than in open gallbladder surgery
- Opinion differs on whether operative cholangiography is essential for recognising bile duct injury One position stresses that early recognition and repair gave successful outcomes in all cases The opposing position holds that intraoperative cholangiography is not essential but pleads for meticulous demonstration of anatomic detail at operation Routine fluoroscopic cholangiography is advocated in any surgeon's first fifty laparoscopic cholecystectomies and thereafter for inflammation, questionable anatomy, leak of golden hepatic bile or aberrant structures
- Techniques to Avoid Injury during Laparoscopic Cholecystectomy
- Techniques to Avoid Injury during Laparoscopic Cholecystectomy (continued)
- Extrahepatic bile duct injuries are iatrogenic and virtually all are preventable Careful dissection of the presumed cystic duct is essential Both junctions of the cystic duct must be identified: to the gallbladder and to the common hepatic duct The junction is exposed after dissecting approximately 1 cm above and 1 cm below it The junction of common hepatic, cystic and common bile ducts is the primary landmark for all biliary operations Injury recognised at surgery may undergo primary repair over a stent or T tube if transection is incomplete
- Strasberg classification of laparoscopic biliary injuries
- Patterns of biliary injury
- Line diagrams of biliary duct division
- Line diagrams of biliary duct division
- Line diagrams of biliary duct division
- Line diagrams of biliary duct division
- Line diagrams of biliary duct division
- Classification of Causes of Laparoscopic Biliary Injuries
- Laparotomy for treatment of complications was required by 1.2% of patients The mean rate of bile duct injury, excluding the cystic duct, was 0.6% The most lethal complications were bowel injuries at 0.14% and vascular injuries at 0.25% The most common origin of postoperative bile leak, at 0.3%, was the cystic duct ERCP resolves isolated bile leaks, but iatrogenic strictures often still require surgery afterwards Both bowel and vascular injuries are difficult to recognise at the time of surgery
- Dropped gallstones cause abscess formation and abdominal wall abscess after laparoscopic cholecystectomy Spillage is avoided by removing the gallbladder intact, in a retrieval bag Lost stones retained in the abdominal cavity should be recorded in the operation note Subcutaneous emphysema may follow carbon dioxide pneumoperitoneum, with hypercarbia and acidosis Hydrocele has followed laparoscopy when high intra-abdominal pressure opened a processus vaginalis Two instances of inferior vena cava injury during trocar insertion have been reported
- Inadvertent subtotal laparoscopic cholecystectomy with bilious ascites has been reported It was managed by exploratory laparoscopy, removal of the stone-containing remnant and drainage Specific presurgical indications exist for deliberate subtotal cholecystectomy in selected high-risk patients Retained stones should be avoided if at all possible An operating room cholangiogram will detect virtually all common bile duct stones When stones are found, duct exploration and removal is the procedure of choice, laparoscopic or open
- 45% of people do not have the whole hepatic arterial supply from the celiac trunk No artery over 0.3 cm in the hepatocystic triangle is a cystic artery 85% of hepatic pedicle variation lies inside Moosman's 30 mm area; half of it is hazardous Expose the cystic-common hepatic junction 1 cm above and 1 cm below before applying any clip Ligate the cystic duct 2-3 mm from the junction, and never skeletonise the duct for more than 2 cm Never explain an abnormal finding as normal: stop and obtain a cholangiogram
- References
- References (continued)
- References (continued)
- Skandalakis' Surgical Anatomy: The Embryologic and Anatomic Basis of Modern Surgery
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