5.5

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In the meantime, direct cholangiography, percutaneous or endoscopic, is now only dedicated to interventional procedures.

In this article we review the clinical impact of modern imaging in emergency conditions of the gallbladder (acute cholecystitis) and bile ducts (cholangitis).

5.5.2 Acute Cholecystitis

Acute inﬂammatory conditions of the gallbladder is a complication of gallbladder stones in most cases. It is very unusual that a patient with no history of biliary symptoms, such as colic pain, develop an acute cholecystitis. Conversely, <15%

of the patients with cholelithiasis experience clinical symptoms and <5% an acute cholecystitis. It may be difficult, from a clinical point of view, to differentiate an acute but regressive attack of pain related to the stone, and acute inflammation. In the first situation, the symptoms disappear within 1 day when treated with anti-inflammatory and antispasmodic agents. In cases of acute cholecystitis, the symptoms are more likely to last longer, and to be resistant to this treatment.

Imaging provides valuable information for several reasons:

1. To ensure the ﬁnal diagnosis, as up to 20% of patients clinically classiﬁed as having acute cholecystitis have another disease that does not require surgery. Converse- ly, it has been demonstrated that surgery was required in all patients with clearly symptomatic gallstones, even without evidence of cholecystitis, as it is more than likely that an emergency treatment will be necessary within months [1].

2. To prevent the patient from complications in case of delayed diagnosis

3. To detect complications such as perforation or gangrenous cholecystitis, which may urge the surgical treatment

In most instances, the surgeon will favour a conservative treatment at the acute phase, and perform delayed surgery.

The optimal period seems to be 2 months after the initial inﬂammatory episode, as the patient may relapse in a less favourable way if surgery is performed beyond this delay

5.5.1 Introduction

Emergency conditions involving the bile ducts and the gallbladder are common radiological challenging problems. Radiology is the standard method for the diagnosis of most situations. In some instances, emergency treatment relies on radiological techniques.

In all situations, a combination of medical, radiological, surgical and endoscopic skills allows the patient to have the beneﬁt of an optimal diagnosis and treatment.

Evaluation of such patients has dramatically changed in recent years. The onset of ultrasonography has been a rev- olution, but still, the development of CT, and more recently MR cholangiography and endoscopic ultrasonography, has provided additional tools for a better and less invasive diagnosis.

Non-traumatic Abdominal Emergencies:

Imaging and Intervention in Acute Biliary Conditions

Y. Menu, M.-P. Vuillerme

5.5

5.5.1 Introduction . . . .481

5.5.2 Acute Cholecystitis . . . .481

5.5.2.1 Ultrasonography . . . .482

5.5.2.2 CT and MRI . . . .484

5.5.2.3 Cholescintigraphy . . . .485

5.5.4 Emphysematous Cholecystitis . . . .485

5.5.5 Gangrenous Cholecystitis . . . .485

5.5.6 Perforation of the Gallbladder . . . .485

5.5.7 Mirizzi Syndrome . . . .485

5.5.8 Cholecystostomy . . . .487

5.5.9 Acute Cholangitis . . . .487

5.5.9.1 Ultrasonography . . . .487

5.5.9.2 Computed Tomography . . . .488

5.5.9.3 Magnetic Resonance . . . .489

5.5.10 Emergency Intervention . . . .490

5.5.11 Conclusion . . . .491

References . . . .491 Contents

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[2]. Recently, laparoscopic surgery has gained acceptance, and it is critical for the surgeon to rule out the indication for open surgery, on the basis of imaging methods. Endo- scopic surgery is so safe that it has been proposed to perform cholecystectomy within the 48 h after the onset of acute cholecystitis, with a lower rate of conversion than in cases of delayed surgery [3].

Ultrasonography plays a major role in the diagnosis, but other methods may have a signiﬁcant value in selected cases.

5.5.2.1 Ultrasonography

Typical appearance of acute cholecystitic is well known.

Usually, in association with gallstones, a combination of wall thickening, intraluminal sludge and sonographic Murphy’s sign is observed (Figs. 1, 2); the latter seems to be the most reliable symptom. The deﬁnition of Murphy’s sign is very precise, and should not be misunderstood: pain is provoked by either the transducer or the sonographer’s palpation un- der guidance, in the exact area of the gallbladder. The pain is the same as the spontaneous pain, blocking deep breathing.

Thickening of the gallbladder wall over 3 mm is a common appearance but is, by far, not characteristic of acute cholecystitis, as it is possible to observe such a ﬁnding in various conditions such as cirrhosis, acute hepatitis and cavernous transformation of the portal vein.Appearance of a striated thickening, and irregular thickening, has been claimed to be more characteristic for cholecystitis but may not prove valuable as a single sign; therefore, it is mandato- ry to rule out the other conditions associated with gallbladder thickening and not requiring surgery. Acute hepatitis may mimic acute cholecystitis very closely, and it is advis- able to compare the imaging results with biological data, especially the level of transaminases.

Ancillary ﬁndings of uncomplicated acute cholecystitis are pericholecystic ﬂuid and gallbladder distension.

Doppler imaging, either colour, power or pulsed Doppler, may show the presence of mural hypervascularization.

Power Doppler may be more sensitive in demonstration of

“hot spots” within the wall, but still is subjective (Fig. 3).

As most patients are examined on the basis of emergency, it has sometimes been questioned if the younger ra- diologists would perform as well as experienced radiolo- gists, who are not always available at the time of examination. This has been studied in a series of 50 patients with different gallbladder diseases by Grantcharov et al. [4]. The authors failed to see any statistical difference between the junior radiologist and the senior radiologist for this kind of patient in the detection of gallbladder stones, but there was a statistical difference of appreciation of the wall thickening, and the calibre of the common bile duct. This means that the junior radiologist can reliably identify gallbladder stones, but the advice of a senior radiologist is required in order to assess more sophisticated ﬁndings such as the evaluation of the gallbladder wall thickening.

Acalculous cholecystitis is a common disease affecting trauma patients, and any patient in intensive care unit (Fig. 4). Similar disease, but much less severe, is seen in patients with AIDS. Inﬂammation of the gallbladder is not related to the cystic duct obstruction by a stone, but it is commonly thought that intravesicular haemorrhage, even moderate, may produce clotting and cystic duct obstruction, favouring infection and inﬂammatory process. Acal- culous cholecystitis is a challenging problem, besides the fact that no stone is seen, because the patients are often in a poor condition, and localized palpation of the abdomen is not very informative. In such cases, percutaneous cholecystostomy may be recommended for diagnosis.

Fig. 1. Acute calculous cholecystitis. A large stone is seen in the gallbladder, as well as wall thickening and some amount of sludge.

Patient was positive for Murphy’s maneuver

Fig. 2. Acute cholecystitis associated with microlithiasis. Wall thickening of the gallbladder is seen (arrows), irregular and less echogenic than in Fig. 1. Large amount of sludge

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Fig. 3.Acute cholecystitis. Ultrasonography, colour Doppler and plain CT.aThis patient had a common cholecystitis with a gallbladder stone, and marked wall thickening.bColour Doppler shows some vessels in the gallbladder wall, consistent with inﬂammation

and hypervascularization.c, dOblique reconstructions of thin slices acquired on multidetector-row CT without contrast injection show an enlarged gallbladder, with a large calciﬁed stone, and stranding of the surrounding peritoneal fat, consistent with inﬂammation

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5.5.2.2 CT and MRI

Both CT and MRI add little information to ultrasonography for the diagnosis of acute cholecystitis; both are helpful in cases with subacute presentation, when the palpation reveals a pseudomass in the right upper quadrant, corre- sponding to pericholecystic inflammation of peritoneum, even in the absence of perforation. In selected cases, the diagnosis between gallbladder cancer and cholecystitis may be difficult. Both CT and MR show an enhancing and smooth inflammatory mass, very different from heteroge- neous cancer. A special problem is the so-called porcelain gallbladder (Fig. 5). Extensive calcification of the gallbladder wall may be misinterpreted on ultrasonography as gas in the wall. Mural calcification are known to be associated with a high probability of gallbladder cancer, and then cholecystectomy should be recommended.

Fig. 4.Acalculous cholecystitis in a trauma patient. The gallbladder was distended, and wall was not clearly thickened, but there is some amount of pericholecystic ﬂuid. Murphy's maneuver was negative in this comatose patient. Percutaneous cholecystostomy was performed in order to assess the diagnosis and treat the patient

Fig. 5. Acute cholecystitis with gallbladder perforation.aOn Ultrasonography, the gallbladder had a thin wall, and a small fluid-filled area was seen at the lower pole of the gallbladder (arrow), but it was difficult to find the relationship with the gallbladder. The patient had peritoneal fluid as well.

bOn contrast-enhanced CT, the gallbladder wall is not thickened but there is a clear disruption in the fundus. Biliary ﬂuid spreads to the subcapsular area, as well as peritoneal space. At surgery, clear perforation of the gallbladder was observed

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5.5.6 Perforation of the Gallbladder

Perforation of the gallbladder is now a rare complication, as early treatment reduces its occurrence. Sonography may shows intraperitoneal fluid, with sometimes an accumula- tion in the pericholecystic area, although the presence of pericholecystic fluid is not a synonym for perforation, as this may be observed in simple inflammatory cases without any perforation. Computed tomography is also helpful and may help in the depiction of the perforation. It is stressed that there should not be an additional delay related to imaging because surgical treatment is an emergency (Fig. 6). In rare cases, gallstones are seen outside of the gallbladder, in the peritoneal cavity. A report of two cases have showed that Doppler ultrasonography would be able to depict the perforation as flow signal passing through the perforated site [7].

5.5.7 Mirizzi Syndrome

Mirizzi syndrome is a manifestation of the impaction of a gallstone in the gallbladder neck that results in obstruction of the bile duct, causing jaundice and/or cholecystocholedochal ﬁstula. The anatomic arrangement of the cystic duct at the gallbladder neck, such that it runs parallel to the common hepatic duct, leads to the possibility of common duct obstruction by a cystic expanding process such as impaction of a stone. Obstruction of the common hepatic duct is mechanical by the stone itself or by secondary inﬂammation, causing intermittent or constant jaundice and/or possible recurrent cholangitis. From a clinical point of view, Mirizzi syndrome may present as a tumor in most 5.5.2.3 Cholescintigraphy

This method is widely used in some countries and com- pletely ignored in others. The principle is to show that the radiopharmaceuticals (diisopropyl-iminodiacetic acid, or DISIDA) fills in the gallbladder within 30 min in normal subjects. In case of cystic duct obstruction, gallbladder will not enhance, even after hours. This very sensitive technique carries a lower specificity, as chronic cholecystitis, and other conditions, such as pancreatitis, hyperalimenta- tion or absence of fasting before the examination, may lead to a similar finding. It is unlikely that cholescintigraphy would become popular in countries where it presently is not used.

5.5.4 Emphysematous Cholecystitis

Gas in the gallbladder wall is called an emphysematous cholecystitis. Gas formation is related to the presence of a micro-organism and is the landmark of a severe life-threat- ening disease. Emphysematous cholecystitis is more common in patients with diabetes mellitus and in older patients.

On sonograms, an echogenic line with ring-down arte- facts is seen in some cases; in others, with a larger amount of gas, this line becomes broader and irregular. In very severe cases, the gallbladder may even be very difﬁcult to differentiate from bowel gas, and this may be an advantage of CT [5].

5.5.5 Gangrenous Cholecystitis

Gangrenous cholecystitis is a severe form of the disease. It is related to wall necrosis. The perforation of the gallbladder wall is a major and early complication. Sonography is not very speciﬁc for the detection of this complication.

Gallbladder wall may be thickened or even thinner than a normal wall. In some instances, intraluminal membranes are seen, but this may be difficult to assess. It has been reported that cholescintigraphy may help when it shows a pericholecystic activity. Computed tomography is proba- bly the best method for identification of gangrenous cholecystitis, although sensitivity, specificity and accuracy of CT for acute gangrenous cholecystitis were 29.3, 96.0 and 64.1%, as compared with 91.7, 99.1 and 94.3%, respective- ly, for acute cholecystitis examined by the same authors [6]. The CT signs in these series were the following: gas in the wall or lumen; intraluminal membranes; irregular wall;

pericholecystic abscess; and association with a lack of mural enhancement, pericholecystic ﬂuid, and a greater degree of gallbladder distension and wall thickening.

Fig. 6. Porcelain gallbladder. Extensive calciﬁcations are seen in the gallbladder wall. Difference between gas and calciﬁcation in the gallbladder wall could be assessed on sonography

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cases as slowly progressive jaundice is the main symptom, rarely as an acute disease due to cholangitis. Mirizzi syndrome is very unusual as Johnson et al. were able to retrieve 11 cases among 4180 patients with biliary stones [8]. Diag- nosis relies on the identification, either by sonography or CT, of a stone in the gallbladder neck area. Sometimes, inflammation is prominent and it may be difficult to localize the stone in the gallbladder neck or in the common bile duct (Figs. 7, 8). This is very important as the management of Mirizzi syndrome is mainly surgical and not endoscopic. Endoscopic retrograde cholangiopancreatography (ERCP), in these exceptional cases, may nevertheless repre- sent the gold standard for imaging as it delineates the cholecystocholedochal fistula and the intracystic localization of the stone.

Fig. 7. Impacted stone in the gallbladder neck (arrow). This is very difﬁcult to detect on sonography as there is no bile surrounding the stone. Posterior shadowing could be overlooked. Arrowhead indicates gallbladder infundibulum; L segment IV of the liver

Fig. 8 a–d.Mirizzi’s syndrome.a–cEnhanced CT showing thickening of gallbladder wall, dilatation of intrahepatic bile duct, inﬂam- matory mass in the porta hepatis, circumscribing the common bile duct. High-density stone is seen in the middle of the inﬂammatory

mass.dPercutaneous cholangiography in the same patient showing the dilated bile ducts, and the extrinsic compression of the common bile duct. Note the dense oval-shaped stone (arrows)

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One-third of the patients with bile duct obstruction, and up to 80% of patients with common bile duct stones have bacteria in the bile ducts.

Sepsis associated with cholangitis is usually very severe, due to the general condition of the patients, who are commonly in their seventh or eighth decade, and may have significant associated diseases such as renal failure or cardio- vascular disease. Although not yet well defined, it has been established that hyperbilirubinaemia increases the general risk by itself. The serum bilirubin level is also a predictor of the risk of sepsis. It is generally accepted that bile stasis in- hibits the anti-toxin effect of the bile salts in the bile ducts and the alimentary tract. Endotoxins, produced by the gram- negative bacteria, may then go in the general circulation and activate an inflammatory response, with several secondary effects such as endothelial cell injury, reduction of blood flow leading to hypotensive shock, deficiency of different immune mechanisms, and changes in platelet function.

The role of imaging in acute cholangitis is essential: diagnosis of bile duct stasis; localization of the obstruction level; and characterization of the obstruction. In emergency patients, common duct stones are the main ﬁndings, because the other aetiologies, such as tumour conditions, are usually revealed by a chronic jaundice.

5.5.9.1 Ultrasonography

Ultrasonography is the technique of choice for the detection of bile duct obstruction in emergency patients. It may be the only method available for patients in intensive care unit, using bedside examinations. The main application for ultrasonography is the detection of bile duct dilatation.

Technically, the examination may be difﬁcult, because emergency patients commonly experience an ileus and abdominal gas distension, which does not favour the examination of the lower part of the common bile duct. Con- versely, in most cases, at least the intrahepatic bile ducts are seen and usually the upper part of the common bile duct is also seen. The level of bile duct dilatation is not exactly cor- related with the severity, but rather to the duration of the obstruction. It is possible that an acute obstruction may cause cholangitis, and not yet bile duct dilatation. Another possibility is that the obstruction varies, with a ball-valve mechanism. In such cases, the obstruction may not lead to severe dilatation. Nevertheless, these situations are unusual, and it should be remembered that in most cases of cholangitis, a bile duct dilatation is present.

Ultrasonography is able to predict the level of obstruction in 80% of the cases. The ability of ultrasonography to detect common bile duct stones is more controversial (Fig. 9). Sensitivity has been reported to be between 22 and 85% [10].

The reasons for these discrepancies are the biases in patient recruitment and bile duct stone prevalence in the studied population. It is commonly thought that ultra-

5.5.8 Cholecystostomy

Surgery, either laparoscopic or open, remains the treatment of choice for acute cholecystitis. In some patients, when surgery would carry a very high mortality, percutaneous cholecystostomy may help the patient to go through the acute phase of the disease. Sometimes, cholecystostomy is used as a diagnostic tool in intensive care patients with inﬂammation of unknown origin and confusing appearance on ultrasonography. In a series of 55 cases, one hepatic bleeding requiring surgery occurred in 1 patient and dis- lodgment of the catheter in 9 patients. Fifty-two patients recovered and 31 were able to undergo delayed cholecystectomy [9].

Cholecystostomy may well be the deﬁnitive treatment for the disease, especially when the patient condition remains poor. Conversely, in patients who recover, delayed surgery remains the recommendation.

Technique of percutaneous cholecystostomy is simple and may be a bedside procedure in intensive care units, using mobile ultrasonography. Computed tomography may be used as the guidance method as well. The gallbladder is punctured through the liver with a catheter needle (22–18 G). In fact, it has been reported that the bile leakage was not more frequent in patient with a direct transperi- toneal approach, but still it should be recommended to go through the liver when possible. A sample of the bile is used for bacteriological studies. Cholecystostomy should remain in the gallbladder for 8–10 days. Cholecystography may be obtained to show the cystic duct patency and the bile ducts. A controversy still exists about the usefulness of early cholecystography through the catheter, but late cholecystography is always useful, especially to check if the cystic duct is patent or not.

5.5.9 Acute Cholangitis

Cholangitis is the result of a combination of bacterial colo- nization of the bile ducts and bile stasis. Most common or- ganisms found in infected bile ducts are Escherichia Coli, Enterococcus and different other gram-negative coliforms.

Although anaerobes are very seldom found in the gallbladder (only in cases of emphysematous cholecystitis), up to 30% of cases of common bile duct stones are associated with such bacteria, especially in older patients. E. Coli pro- duces B-glucuronidase which favours deconjugation of the bilirubin in bile. The result is the formation of bile stones with high bile pigment content. Obstruction favours infection, and infection favours stone formation. This is the rea- son why any chronic bile duct obstruction may be associated with stones. In other words, when there are stones in the common bile ducts, imaging should rule out another cause of obstruction. The normal bile ducts are free of bacteria.

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sonography detects one-third of the stones. Conversely, speciﬁcity is very high, which means that once the diagnosis of common bile duct stones is made by ultrasonography, there is no need for further diagnostic evaluation, unless additional data are required for other abdominal organs.

Detection of stones in the common bile duct is difﬁcult mainly due to the possibility of gastric or duodenal gas preventing the examination of the lower bile duct. Other reasons are the absence of bile duct dilatation, small size of the stones and mild shadowing behind crumbly stones.

The only problems with false positives are gas in a para- papillary duodenal diverticulum, pancreatic calciﬁcation adjacent to the bile duct and associated with bile duct obstruction of pancreatic origin, and ﬁnally some cases of unusual appearance of the right branch of the hepatic artery.

Endoscopic sonography is a recognized method for the detection of common bile duct stones with a reported sensitivity of 94.9%, a speciﬁcity of 97.8%, and an accuracy of 95.9% [11].

5.5.9.2 Computed Tomography

Computed tomography is not routinely used to assess the dilatation of the bile ducts, due to the accuracy of ultrasonography, but may help in cases difﬁcult to examine with ultrasound, especially in the extrahepatic course of the common duct, and to evaluate the surrounding organs such as the duodenum and the pancreas which are sometimes involved in biliary processes.

The detection of stones in the common duct is better achieved with CT than with ultrasonography, but still the sensitivity is lower than that of magnetic resonance cholangiopancreatography (MRCP). The CT sensitivity is

usually reported as 70–80%. In a series of 40 patients with endosuspected common bile duct stones, Jimenez Cuenca et al. found 19 stones with ERCP, and 15 of these 19 stones were identiﬁed using unenhanced helical CT [12]. As most common bile duct stones are faintly hyperdense, there is no chance to detect them after contrast injection (Figs. 10, 11).

Helical CT is helpful as it provides true contiguous and even overlapping slices. Thin slices are useful to avoid the partial-volume effect, but conversely, too thin slices are in- adequate to evaluate true density of the stone. A better combination would be achieved with multidetector CT, which allows the reconstruction of a double set of images:

Thick slices (6 mm) should be used for density measure- ments, and thin slices (2–3 mm) for the precise localization of density abnormalities. Reconstruction may help in some instances and are facilitated by multidetector CT and thin slices (Fig. 12). The appearance of stones varies according to the size and content: stone density varies from bile density, then indistinguishable, to calcium density. In most cases calciﬁcation is mild and should be carefully exam- Fig. 9. Common bile duct stone seen on sonography. The common

bile duct was seen until the papilla, allowing the identiﬁcation of a small stone

Fig. 10 a, b. Patient with a large stone in the lower common bile duct.aUnenhanced CT showing a faint hyperdensity in the com- mon bile duct (arrow).bEnhanced CT: The image could be overlooked for a dilated bile duct without any stone if no reference had been made to the plain CT

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ined on plain slices. When increasing in size, the stones have a layered appearance, with one or several dense layers, and low-density intermediate layers.

Computed tomographic cholangiography has been claimed to increase CT sensitivity for the detection of stones. In a series of 101 patients with suspected common bile duct stones, CT cholangiography was positive in 21 of 22 proved stones, and no false positive was observed [13].

Despite these results, CT cholangiography has not gained acceptance, because MRCP sensitivity remains better, and biliary contrast injection is not allowed in case of severe obstruction.

5.5.9.3 Magnetic Resonance

Magnetic resonance cholangiopancreatography has had a tremendous impact on the management of bile duct diseases, as for the ﬁrst time, images with anatomical details very similar to those of direct cholangiography were made available with a totally noninvasive procedure. There are varieties of sequences dedicated to MRCP, and still there is no standard protocol. The basis of the examination is that thin slices of the bile ducts should be acquired as well as

“cholangiographic” views (usually thick slices in coronal, sagittal, or oblique planes). Most authors favor a combination of bile duct imaging and parenchymal imaging (liver and pancreas) in the same session (Fig. 13). Recently, ad- vances in MRCP with contrast injection have been present- ed but are not yet accepted in a routine examination.

In a representative series of 51 patients, 26 patients (51%) had stones [14], sensitivity was 65% for unenhanced helical CT, 92% for CT cholangiography, and 96% for MRCP. Speciﬁcity was 84% for unenhanced helical CT, 92%

for CT cholangiography and 100% for MR cholangiography, the difference being statistically significant. Differ- ences in specificity were not significant.

In a series of 286 consecutive patients [15] MRCP was compared with ERCP, percutaneous transhepatic cholangiography, intraoperative cholangiography and surgical or imaging follow-up ﬁndings. Prevalence of stones was 27%

in this series. The MRCP sensitivity was 92% and speciﬁci- ty was 97%. Interobserver agreement was excellent with a 0.84 kappa.

These two series are representative of very homoge- neous reports from the literature. Pitfalls for MRCP are the following: it is difﬁcult to examine patients with a poor general condition, and especially patients with a systemic shock; aerobilia may be overlooked as stones, if no reference is made to the axial slices (Fig. 14); even if the se- quence time is very short, a minimal cooperation from the patient remains necessary. These are a few reasons why not all MRCP examinations are optimal. One last pitfall of MRI is a low availability in many centres, especially for emergency patients. Finally, the main limitation of MRCP is the size of the stones. When smaller than 2 or 3 mm, the prob- Fig 11 a, b. Patient with intrahepatic stones.a Unenhanced CT

showing a calciﬁed intrahepatic stone in the right hepatic duct.

bAfter injection, this dense stones is hypodense

Fig. 12. A CT reconstruction through the common bile duct in a patient with multiple stones. This multiplanar reformation has been performed with 3-mm-thick slices and a 1.5-mm reconstruction interval

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ability to be overlooked is high. Even larger stones, up to 6 mm, may be difﬁcult to detect [16]. Technical improve- ments may enhance the capability of MRCP to detect small stones, but it is likely that imaging of very small stones will remain a challenging issue.

5.5.9.10 Emergency Intervention

It is very uncommon that cholangitis would require an emergency intervention, percutaneous, endoscopic, or surgical. Treatment includes fluid resuscitation and an- timicrobial agents that cover enteric flora. Biliary decom- pression is required when patients do not rapidly respond to conservative therapy. Definitive therapy can be performed by a surgical, percutaneous, or endoscopic route.

Historically, surgery has been the gold standard, but in the past 20 years or so, endoscopic removal of stones has gained wide acceptance. One question was the prevalence of complications of long-term endoscopic sphincterotomy, especially in young patients. In a series of 94 patients less than 60 years old with a mean follow-up of 15 years, late complication rate was 24% [17]. Most of these problems were stone recurrence, and almost all could be treated during a new endoscopic session. These results explain why endoscopy is now the treatment of choice for common bile duct stones, whether it be associated with laparoscopic cholecystectomy or not when gallstones are seen.

Percutaneous treatment is seldom necessary for common bile duct stones, as endoscopic removal is feasible in most cases. In a few instances, when endoscopy is not possible (local variants, previous surgery with biliary enteric anastomosis), percutaneous management is useful. Advan- tages of the percutaneous route are the following: possibility to perform an associated choledocoscopy, although endosonography and cholangioscopy have similar results [18]; possibility to perform intraluminal lithotripsy or lithotomy; and absence of permanent sphincterotomy. Dif- Fig. 13. Magnetic resonance cholangiopancreatography showing a

very small stone in the right hepatic duct. Combination of axial

and coronal slices allows more conﬁdence for the diagnosis of small stones

Fig. 14. Patient with aerobilia. Air, like stones, is seen as a black area, with no signal. Axial slices show that the stones lay on the posterior aspect of the common bile duct, as they are heavier than the bile. In this case, there is an air-ﬂuid level

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tion: color Doppler ﬁndings. Abdom Imaging 27:47–50 8. Johnson LW, Sehon JK, Lee WC et al. (2001) Mirizzi’s syn-

drome: experience from a multi-institutional review. Am Surg 67:11–14

9. Spira RM, Nissan A, Zamir O et al. (2002) Percutaneous transhepatic cholecystostomy and delayed laparoscopic cholecystectomy in critically ill patients with acute calculus cholecystitis. Am J Surg 183:62–66

10. Contini S, Dalla Valle R, Campanella G (1997) Reliability of ultrasound in detecting common bile duct stones before biliary surgery. A retrospective analysis. Panminerva Med 39:106–110 11. Palazzo L, Girollet PP, Salmeron M et al. (1995) Value of endoscopic ultrasonography in the diagnosis of common bile duct stones: comparison with surgical exploration and ERCP. Gas- trointest Endosc 42:225–231

12. Jimenez Cuenca I, del Olmo Martinez L, Perez Homs M (2001) Helical CT without contrast in choledocholithiasis diagnosis.

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stones: comparison of unenhanced helical CT, oral contrast- enhanced CT cholangiography, and MR cholangiography. Am J Roentgenol 175:1127–1134

15. Boraschi P, Neri E, Braccini G et al. (1999) Choledocolithiasis:

diagnostic accuracy of MR cholangiopancreatography. Three- year experience. Magn Reson Imaging 17:1245–1253 16. Zidi SH, Prat F, Le Guen O et al. (1999) Use of magnetic reso-

nance cholangiography in the diagnosis of choledocholithiasis: prospective comparison with a reference imaging method.

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17. Bergman JJ, van der Mey S, Rauws EA et al. (1996) Long-term follow-up after endoscopic sphincterotomy for bile duct stones in patients younger than 60 years of age. Gastrointest Endosc 44:643–649

18. Tamada K, Ohashi A, Tomiyama T et al. (2001) Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identiﬁcation of residual bile duct stones during lithotripsy. J Gastroenterol Hepatol 16:100–103 19. Van der Velden JJ, Berger MY, Bonjer HJ et al. (2000) Percuta-

neous treatment of bile duct stones in patients treated unsuccessfully with endoscopic retrograde procedures. Gastrointest Endosc 51:418–422

20. Yoshimoto H, Ikeda S, Tanaka M et al. (1989) Choledochoscop- ic electrohydraulic lithotripsy and lithotomy for stones in the common bile duct, intrahepatic ducts, and gallbladder. Ann Surg 210:576–582

ferent techniques should be used to treat the stones. Bal- loon dilatation of the sphincter will allow to push and ﬂush the stones through the papilla: in a series of 31 patients, the success rate was 87% [19] with a mean treatment time of 16 days. Dormia baskets help to retrieve the stones, as long as they are large enough to be strongly tightened in it. En- docacitary lithotomy or lithotripsy can be performed to burst large stones in smaller fragments with a high success rate [20]. A combination of these different methods may be used according to each situation. In fact, it may be haz- ardous to compare the results of endoscopic and percutaneous treatment, because the patients referred to the latter have usually been unsuccessfully treated by the endoscopic approach.

5.5.11 Conclusion

Imaging methods are necessary for the management of acute biliary conditions. Ultrasonography remains the most simple method, and should always be performed ﬁrst.

At the end of this examination, the radiologist should be able to decide which patients require additional exploration, and to be able to choose between CT and MRCP, and in some instances endosonography. Intervention is seldom necessary during the ﬁrst hours, but it may be critical in the integrated management of these patients in general with endoscopist and surgeon.

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