Gallstone diseases and related disorders Flashcards
1
Q
Gallstone diseases and related disorders
A
- Most gallstone-related disease presents with pain, typically located in the epigastrium or right hypochondrium (right upper quadrant or RUQ).
- The character of the pain varies but in most cases, it is acute and intermittent.
- Less commonly, gallstone disease presents as pain and jaundice caused by a stone passing into and obstructing the common bile duct.
2
Q
Gallstone diseases and related disorders
Structure and function of the biliary system
A
- Bile collects in canaliculi between hepatocytes and drains via collecting ducts within the portal triads into a system of ducts within the liver.
- Increase in diameter until they become the right and left hepatic ducts to form the common hepatic duct.
- This is joined further distally by the cystic duct to become the common bile duct. The common bile duct is 4–5 cm long and passes down behind the duodenum then through the head of the pancreas to drain via the ampulla of Vater into the medial wall of the second part of the duodenum. The main pancreatic duct joins the common bile duct at the ampulla although it may enter the duodenum independently.
- The sphincter of Oddi within the ampulla prevents reflux of duodenal contents into the common bile duct and pancreatic duct.
3
Q
Structure and function of the biliary system
The gallbladder
A
- A muscular sac lined by mucosa characterised by a single, highly folded layer of tall columnar epithelial cells.
- Mucus-secreting glands are found at the neck of the gall bladder but are absent from the body and fundus.
- The proximal part of the duct is disposed into a spiral arrangement called the spiral valve, the function of which is not well understood.
- The gall bladder lies in a variable depression in the under-surface of the right hepatic lobe and is covered by the peritoneal envelope of the liver.
- The common bile duct is a fibrous tissue tube lined by a simple, tall columnar epithelium. Normally it is up to 0.6 cm in diameter and this can be measured on ultrasound scanning.
4
Q
Gall bladder
Gallstone composition
A
- Most gallstones are of mixed composition and contain a predominance of cholesterol; this is mixed with some bile pigment (calcium bilirubinate) and other calcium salts.
- A small proportion is virtually ‘pure’ cholesterol stones (‘cholesterol solitaire’).
- In Asia, most gallstones are composed of bile pigment alone
5
Q
Pathophysiology of the biliary system
The role of inflammation and infection
A
- Inflammation and infection probably both play a part in gallstone formation.
- Abnormalities of bile composition may cause chemical inflammation of the gall bladder, resulting in inflammatory exudation and accumulation of inflammatory debris.
- Bacteria usually form the organic nidus upon which gallstones are built; they enter the gall bladder intermittently by reflux from the duodenum or via the bloodstream.
- This process is probably normal but becomes pathological if the bacteria are not flushed out, as occurs when the gall bladder does not adequately empty.
- In support of this is the fact that faecal organisms can be cultured from at least 25% of cholecystectomy specimens.
6
Q
Investigation of gall bladder pathology
The non jaundiced patient
A
- Patients with gallstones but no history of obstructive jaundice do not require preoperative investigation for duct stones apart from an ultrasound scan and LFTs.
- If cholecystectomy is needed, intraoperative (or perioperative) cholangiography may be carried out.
- A cannula is passed through the cystic duct into the common bile duct and radiopaque contrast material injected to fill the biliary tree. X-rays or fluoroscopic imaging are then used to demonstrate the duct morphology and abnormalities such as duct dilatation, filling defects caused by stone, or distortion of the tapering lower end of the common duct, as well as obstruction of flow into the duodenum.
- If cholangiography shows stones, the duct may be explored at the time or else dealt with later by endoscopic retrograde cholangio-pancreatography (ERCP).
- Patients with a history of transient jaundice possibly attributable to stones will have either operative cholangiography at cholecystectomy or preoperative ERCP.
7
Q
Pathophysiology of the biliary system
The role of chronic obstruction
A
- Most gall bladders removed for chronic pain show histological features more in keeping with a chronic obstructive aetiology than an infective one.
- These include atrophic mucosa, submucosal and subserosal fibrosis, hypertrophy of the muscular wall, and mucosal diverticula extending into the muscular layer (known as Rokitansky–Aschoff sinuses). Evidence of active or previous infection is uncommon.
- In some cases the gall bladder is so grossly scarred, distorted or contracted that its absorptive and contractile functions have been completely destroyed.
8
Q
Investigation of gall bladder pathology
Blood tests and imaging
A
- Haemolytic disorders such as hereditary spherocytosis, thalassaemia and sickle-cell trait should be considered as they may predispose to pigment stones.
- Liver function tests (LFTs) are indicated to look for indications of common duct stone obstruction if there is any suggestion of jaundice and to exclude other liver abnormalities.
- Ultrasonography can reliably identify stones in the gall bladder and any increase in thickness of the wall
9
Q
Investigation of gall bladder pathology
Objectives
A
- Exclude haematological and liver abnormalities and other metabolic disorders
- Establish if gallstones are present in the gall bladder and/or common duct and whether the gall bladder wall is thickened
- Assess the integrity and patency of the bile duct system and the pancreatic duct (if there is any suggestion of obstruction)
10
Q
Investigation of gall bladder pathology
The jaundiced patient
A
- When obstructive jaundice has been diagnosed, it is important to distinguish between stone and tumour in order to plan appropriate management.
- Ultrasonography is usually the initial investigation. This shows the extent of dilatation of intrahepatic and extrahepatic ducts and may even show a stone lodged at the lower end of the duct.
- If stones are in the gall bladder, this suggests stones are blocking the duct rather than tumour, but the two can coexist.
- The ultrasound scan will usually demonstrate the presence of a carcinoma of the pancreatic head or enlarged lymph nodes in the porta hepatis; either may cause extrahepatic biliary obstruction.
11
Q
Clinical presentations of gallstone disease
A
- Gallstones may cause chronic, low-grade symptoms, often labelled chronic cholecystitis.
- However, many of these symptoms may be due to irritable bowel syndrome or chronic aerophagia (air swallowing).
- Transient obstruction of the gall bladder by stone may cause episodes of acute pain (biliary colic).
- If the obstruction persists, the gall bladder becomes chemically inflamed causing acute cholecystitis.
- If obstruction does not resolve by itself and the contents do not become infected, the gall bladder becomes distended with mucus; this is known as a mucocoele, and is often palpable and tender.
- If the contents become infected, an abscess develops within the gall bladder and this is known as an empyema of the gall bladder.
12
Q
Clinical presentations of gallstone disease
A
- Gallstones may cause chronic, low-grade symptoms, often labelled chronic cholecystitis.
- However, many of these symptoms may be due to irritable bowel syndrome or chronic aerophagia (air swallowing).
- Transient obstruction of the gall bladder by stone may cause episodes of acute pain (biliary colic).
- If the obstruction persists, the gall bladder becomes chemically inflamed causing acute cholecystitis.
- If obstruction does not resolve by itself and the contents do not become infected, the gall bladder becomes distended with mucus; this is known as a mucocoele, and is often palpable and tender.
- If the contents become infected, an abscess develops within the gall bladder and this is known as an empyema of the gall bladder.
13
Q
- *Biliary colic**
- Clinical features*
A
- intermittent cystic duct obstruction by stone. The pain is severe; it typically rises to a plateau over a few minutes then continues unrelentingly
- does not have the strikingly intermittent brief peaks of other forms of colic (e.g. ureteric)
- patients may be in agony until the pain resolves spontaneously after several hours or after opiate analgesia
- Vomiting is often associated with the attack and the patient feels exhausted and sore for the next day or so.
- If the attack does not settle within 24 hours, acute cholecystitis is a more likely diagnosis
14
Q
Biliary colic
Management
A
- Relief of pain usually requires only one injection of an opiate and the attack passes.
- In acute gallstone disease, cholecystectomy scheduled for the next available list is preferred by many surgeons and is generally safe
- Cholecystectomy is the definitive treatment for attacks of biliary colic. Patients put on a low-fat diet whilst awaiting operation, often relieves symptoms, presumably by removing a stimulus to gall bladder contraction.
15
Q
- *Acute cholecystitis**
- Pathophysiology and clinical features*
A
Several factors contribute to causing acute inflammation in an obstructed gall bladder.
- These include physical and chemical irritation and, later in the episode, bacterial infection.
- The clinical result is acute cholecystitis, which often presents as a surgical emergency.
- In contrast to biliary colic, the patient is usually systemically unwell with a fever and tachycardia.
- On examination there is tenderness in the right upper quadrant, more marked on inspiration and a tender inflammatory gall bladder mass may be palpable.
- The term ‘Murphy’s sign’ is often misused in this context; it was originally used to describe tenderness at the tip of the ninth rib.
- Being inflammatory in origin, the clinical course of acute cholecystitis is more prolonged than biliary colic, usually lasting several days before settling or else precipitating urgent surgery.
17
Q
Empyema of the gall bladder
A
- Empyema, represents an abscess of the gall bladder.
- As with abscesses elsewhere, a swinging pyrexia is often found.
- Part of the gall bladder wall becomes necrotic, leading to perforation which causes a subphrenic abscess or generalised peritonitis.
- These patients require surgery without delay.
- Gangrenous cholecystitis and perforation are rare because the gall bladder has a rich blood supply from its hepatic bed as well as from the cystic artery.
18
Q
Cholecysto-duodenal fistula and gallstone ileus
A
- Occur when the inflamed gall bladder becomes adherent to the adjacent duodenum and a stone ulcerates through the wall to form a cholecysto-duodenal fistula.
- The fistula decompresses the obstructed gall bladder and allows stones to pass into the bowel and gas to enter the biliary tree.
- The condition is usually painless and unsuspected but may be diagnosed on plain abdominal X-ray by the presence of gas outlining the biliary tree
- Sometimes a fistula is discovered at operation.
19
Q
Carcinoma of the gall bladder
A
- Chronic irritation by stone over a long period is believed to predispose to adenocarcinoma of the gall bladder.
- This condition is rare and only found in the elderly. The presenting symptoms are similar to chronic inflammatory gall bladder disease.
- Jaundice may develop if the tumour obstructs the bile ducts.
- Carcinoma of the gall bladder is usually an unexpected finding at cholecystectomy for stones and is often incurable by the time of detection.
20
Q
Ascending cholangitis
A
- Bile stasis in the common duct occurs with chronic obstruction and dilatation and predisposes to bacterial infection.
- The condition is known as ascending cholangitis and is a potent cause of systemic sepsis.
- It is characterised by intermittent attacks of pain, swinging pyrexia and jaundice.
- This triad is referred to as Charcot’s intermittent hepatic fever and is often accompanied by marked weight loss.
- Ascending cholangitis is a serious condition and may culminate in life-threatening acute suppurative cholangitis.
- The bile duct must be drained urgently, either by surgical operation or preferably by endoscopic sphincterotomy.
21
Q
Surgical management of gallstones
Indications for surgery and preparation of the patient
A
- Symptomatic gallstone disease
- Asymptomatic gallstones when there is a reasonable likelihood of future symptoms or complications
- If stones in duct system, common duct exploration is added to cholecystectomy or else stones are extracted at ERCP
22
Q
Cholecystectomy—open versus laparoscopic surgery
A
- Laparoscopic cholecystectomy is now the gold standard treatment for gallstones.
- All surgeons performing this operation must also be able to competently perform the laparoscopic operation but also a potentially difficult open operation to cope with the occasional conversion to open operation brought about by unexpected difficulties or complications arising during a laparoscopic operation.
23
Q
- *Operations on the common bile duct
- Exploration of the common bile duct***
A
- The duct is opened through a longitudinal or transverse incision and stones retrieved by a combination of manipulation, irrigation, grasping with stone forceps or a Dormia basket or use of a balloon catheter.
- Operative choledochoscopy is often used to check for residual stones and to remove difficult stones.
- A flexible fibreoptic choledochoscope gives good visibility and manoeuvrability and can also be used in laparoscopic surgery.
- After exploration, a latex T-tube is usually inserted to drain bile to the exterior, with the transverse limb placed within the common bile duct.
- The main purpose of a T-tube is to provide access to the biliary tree for a further cholangiogram about 1 week after operation
24
Q
Complications of biliary surgery
A
- The retained stone
- Biliary peritonitis
- Bile duct damage
- Haemorrhage
- pre-existing jaundice
- Ascending cholangitis and other infections
- subphrenic abscess
