Br. J. Surg. Vol. 63 (1976) 51-54
Operative cholangiography : criteria which make exploration of the common bile duct desirable C. G . M A R K S A N D F . M . K E L V I N * SUMMARY
The purpose of this study was to evaluate the individual criteria and combination of criteria examined by operative cholangiography which make exploration of the common bile duct desirable. The overall accuracy of exploration of the common bile duct (89 per cent) was similar to that of previous series. In the normal group the accuracy of the criteria established by L e Quesne (1960) is confirmed. The most reliable criteria in the abnormal cholangiograms were the presence of single or multiple filling defects in the common bile duct, the absence of free $ow of contrast medium into the duodenum and an abnormality of the terminal narrow segment. Measurements to aid assessment of free flow into the duodenum are suggested. I n 34 of 40 positive explorations the common bile duct diameter was 14 mm or less; I 0 common bile ducts which contained stones were less than I0 m m in diameter. Excess filling of the intrahepatic ducts was often impossible to judge in the abnormal group and was the least valuable criterion. Attention is drawn to the advantage o f a n immediate radiological report.
THEcriteria for a normal operative cholangiogram were stated by Le Quesne (1960): 1. The diameter of the common bile duct measures 12 mm or less. 2. Free flow of contrast occurs into the duodenum. 3. The terminal narrow segment of the common bile duct is clearly seen on at least one film. 4. Absence of filling defects in the common bile duct. 5. N o excess retrograde filling of the intrahepatic ducts. Fig. 1 illustrates a normal operative cholangiogram. Le Quesne considered that all these conditions had to be fulfilled for the examination to be interpreted as normal and the absence of any one of the criteria was an indication for the exploration of the common bile duct. The present study attempted to assess the validity of these criteria in patients whose common bile duct contained stones. Patients and methods One hundred and seventeen operative cholangiograms undertaken by two surgeons (Mr T. Rowntree and Mr C . G. Marks) during cholecystectomies for calculous disease between September 1971 and December 1974 were examined. Patients with biliary disease other than calculi have been excluded from this series.
Fig. 1. Normal operative cholangiogram after injection of 3 ml of contrast medium showing a normal terminal narrow segment and filling of the duodenum.
Operative technique After the patient had been positioned with the left side raised 15", the abdomen was opened and a Stoke-onTrent cannula inserted into the cystic duct. The cannula was flushed with saline to remove air bubbles from the system. Three films were then taken, at a focal film distance of approximately 100 cm, after the slow injection of 3, 6 and 10ml of Hypaque 25 per cent. The gallbladder was removed whilst the films were being processed, which were then immediately reported by a radiologist. The films were returned to the operating theatre and the decision whether or not to explore the common bile duct was made. Radiological assessment 1. Immediate report. This refers to the radiologist's report made during the operation. 2. After the operation the X-rays were reviewed independently by two radiologists. 3. Subsequently, each cholangiogram was assessed for the five criteria described by Le Quesne (1960).
* Southampton University Hospitals. Present address of C . G . Marks: Radcliffe Infirmary, Oxford. 51
C. G. Marks and F. M. Kelvin
Fig. 2. Abnormal cholangiogram showing reduced density of contrast medium in the duodenum compared with that in the common bile duct, and an irregular terminal narrow segment.
Fig. 3. Cholangiogram showing a normal terminal narrow segment in a common bile duct containing two air bubbles immediately below the catheter tip.
Table I: ACCURACY OF INDIVIDUAL CRITERIA Normal Abnormal group group Overail (52 patients) (40 patients) aCcUracy Criterion No. % No. % (%) Diameter of common I3 25 30 15 75 bile duct > 10 mm No free flow into duodenum measured by length of duodenum filled 5 10 37 ;:}88 First film: < 2 cm Second film: < 7 cm 7 13 32 Abnormal terminal 6 12 35 87.5 88 narrow segment Filling defects 1 2 39 97.5 98 No excess filling of 1 2 13 33 70 intrahepatic ducts
patient’s symptoms or subsequent surgical management. Twenty-eight of these patients underwent exploration of the common bile duct followed by T tube cholangiograms. The presence of calculi was confirmed in 23. The accuracies of the immediate report and of the two radiologists in this group were 80, 84 and 80 per cent respectively. There were 5 negative explorations, all of which were followed by normal T tube cholangiograms. These, together with the 47 cholangiograms reported normal on all three reports, form the 52 patients in the normal group. This is a reasonable assumption in view of the findings of Chapman et al. (1964) that a normal operative cholangiogram is a reliable indication of a normal biliary tree, as shown by subsequent clinical follow-up and intravenous cholangiography.
These criteria were then analysed in the light of the abnormal findings or assumed normality (see below).
Analysis of individual criteria Table I illustrates the accuracy of the individual criteria for the normal and abnormal groups. Each of these criteria will be discussed in turn.
5ll.5
Results Of the patients whose common bile duct was not explored, 25 were excluded from the analysis because either the cholangiograms were technically unsatisfactory or there was lack of agreement in the radiological reports. Forty-five of the remaining 92 patients underwent exploration of the common bile duct. Calculi were found in 40 of the explorations. These 40 patients constitute the abnormal group. To compare the accuracy of the immediate report with that made on review, the X-rays of the first 75 patients were examined without information about the 52
1 . Diameter of the common bile duct If a diameter of 14 mm (Wise, 1962; Chapman et al., 1964) is taken as the upper limit of normal, all 52 normal patients in the present series were included. The upper limit for the diameter of a normal common bile duct has been described at between 10 and 14 mm (Le Quesne, 1960; Wise, 1962; Chapman et al., 1964; McEvedy, 1970). However, in the present series 34 of the 40 abnormal cholangiograms demonstrated a common bile duct diameter of 14 mm or less, and 10 of these were below 10mm. This incidence is lower
Operative cholangiography than that of Hicken and McAllister (1964), who stated that ’at least 40 per cent of the calculi we have removed were extracted from ducts measuring I cm or less in diameter’. We agree with Le Quesne et al. (1959) that there is a wide range of common bile duct diameters in normal cholangiograms, and that a common bile duct diameter of 10 mm is the best dividing point between the two groups, giving an overall accuracy of 75 per cent in the present series. The figure of 10 mm has been used in Table I . 2. Free flow of contrast medium into the duodenum Although initially a subjective assessment, this parameter proved to be accurate. An attempt was then made to quantify normal free flow by measuring the length of duodenum filled with contrast medium. Forty-seven of the 52 normal cholangiograms showed a length of 2 cm or more on the first film (Fig. 1). Only 3 of the abnormal group showed this. On the second film a length of 7 c m or more favoured normality (present in 45 of the 52 normal and in 8 of the 40 abnormal cholangiograms). These measurements were 91 and 84 per cent accurate respectively. Clearly, these measurements are dependent upon using the same volumes of contrast medium (3, 6 and 10ml) and a similar pressure of injection. Other variables such as the degree of duodenal relaxation and the type of anaesthesia may affect these measurements. Nevertheless, in practice, they were found to be very useful. In the abnormal group it was observed that the density of contrast medium in the duodenum was often less than in the common bile duct (Fig. 2). This was not a feature of the normal cholangiogram.
3. A normal terminal narrow segment This showed an overall accuracy of 88 per cent. Within the abnormal group differing appearances were seen. Most commonly the terminal segment was not visualized at all (21 patients). Three cholangiograms showed a small filling defect within it. On 8 occasions the segment filled but with an irregular outline (Fig. 2). This was in marked contrast to the tapering outline seen in the normal group (Fig. 3). Occasionally it was difficult to be sure that filling was normal, especially when there was duodenal superimposition or an excessively long exposure resulted in blurring. 4. Absence offilling defects Table Zshows that this was the most accurate criterion (98 per cent reliable). Filling defects due to calculi were usually characteristic (Fig. 2). Those due to air bubbles (Fig. 3) or to the catheter tip were excluded from the analysis when the cholangiogram clearly indicated either to be the cause. It is essential to use small volumes of a low concentration of contrast medium in order not to obscure small calculi. 5. No excess retrograde filling of the intrahepatic ducts The overall accuracy of this was 70 per cent, because this was the most subjective and therefore the most difficult criterion to assess. This assessment was proved to be the least valuable in the abnormal group.
Table 11: ACCURACY OF COMBINATIONS OF CRITERIA IN THE ABNORMAL GROUP Combined accuracy Combinations of criteria Filling defect(s) in common bile duct No free flow into duodenum Filling defect(s) in common bile duct Abnormal terminal narrow segment No free flow into duodenum Abnormal terminal narrow segment Filling defect(s) in common bile duct N o free flow into duodenum Abnormal terminal narrow segment
No.
%
31
92.5
34
85
33
82.5
33
82.5
Only 13 of the 40 abnormal cholangiograms were considered to show undue intrahepatic filling when compared with the normal cholangiograms.
Discussion The 89 per cent accuracy of operative cholangiograms in predicting stones in the common bile duct is similar to other series, with accuracies of 72 per cent (Wheeler et al., 1970), 73 per cent (McEvedy, 1970) and 92 per cent (Havard, 1970). Both surgeons in the present series found an immediate radiological opinion helpful whenever they had doubts about the interpretation of the cholangiogram, although in many centres the radiologist reports the operative cholangiogram after the completion of the operation. In the normal group all the criteria were of a high degree of accuracy. In the abnormal group three criteria were at least 80 per cent accurate (Table I ) : the presence of a filling defect, the absence of free flow into the duodenum and an abnormal terminal narrow segment. Different combinations of these three criteria were then considered (Table ZI). The best combination was the presence of filling defects and the absence of free flow on the first film, defined as less than 2 c m of contrast medium in the duodenum. Nevertheless, the accuracy of this combination (92.5 per cent) was less than that of filling defects alone (97.5 per cent) in this series. Acknowledgements We are grateful to Dr F. J. Brunton for his help in reviewing the X-rays, and to Mr T. Rowntree for permission to publish details of his patients. We would also like to thank Mr D. Brown for his assistance with the data analysis, and Mrs Alison Wilcox and Mrs Marguerite Benge for their secretarial help. References and LE QUESNE L. P. (1964) Operative cholangiography. An assessment of its reliability in the diagnosis of a normal, stone-free common bile duct. Br. J. Surg. 51, 600-601. HAVARD c . (1970). Operative cholangiography. Br. J. Sltrg. 57, 797-807. HICKEN N. F. and MCALLISTER A. J. (1964) Operative cholangiography as an aid in reducing the incidence of ‘‘overlooked’’ common bile duct stones : a study of 1,293 choledocholithotomies. Srwgery 55, 753-758. CHAPMAN M., CURRY R. c .
53
C. G. Marks and F. M. Kelvin (1960) Discussion of cholangiography. Proc. R. SOC.Med. 53, 852-855. LE QUESNE L. P., WHITESIDE C. G. and HAND B. (1959) The common bile duct after cholecystectomy. Br. Med. J . 1, 329-332. MCEVEDY B. v. (1970) Routine operative cholangiography. Br. J. Sirrg. 57, 211-219. LE QUESNE L. P.
54
and WILLIAMS J. A. (1970) Operative cholangiography. Its effect on the practice of cholecystectomy. Br. Med. J. 4, 161164. WISE R. E. (1962) Intravenous Cholangiography. Springfield, Ill., Thomas. WHEELER M. H., RAKASOOK S.
Operative cholangiography : criteria which make exploration of the common bile duct desirable C. G . M A R K S A N D F . M . K E L V I N * SUMMARY
The purpose of this study was to evaluate the individual criteria and combination of criteria examined by operative cholangiography which make exploration of the common bile duct desirable. The overall accuracy of exploration of the common bile duct (89 per cent) was similar to that of previous series. In the normal group the accuracy of the criteria established by L e Quesne (1960) is confirmed. The most reliable criteria in the abnormal cholangiograms were the presence of single or multiple filling defects in the common bile duct, the absence of free $ow of contrast medium into the duodenum and an abnormality of the terminal narrow segment. Measurements to aid assessment of free flow into the duodenum are suggested. I n 34 of 40 positive explorations the common bile duct diameter was 14 mm or less; I 0 common bile ducts which contained stones were less than I0 m m in diameter. Excess filling of the intrahepatic ducts was often impossible to judge in the abnormal group and was the least valuable criterion. Attention is drawn to the advantage o f a n immediate radiological report.
THEcriteria for a normal operative cholangiogram were stated by Le Quesne (1960): 1. The diameter of the common bile duct measures 12 mm or less. 2. Free flow of contrast occurs into the duodenum. 3. The terminal narrow segment of the common bile duct is clearly seen on at least one film. 4. Absence of filling defects in the common bile duct. 5. N o excess retrograde filling of the intrahepatic ducts. Fig. 1 illustrates a normal operative cholangiogram. Le Quesne considered that all these conditions had to be fulfilled for the examination to be interpreted as normal and the absence of any one of the criteria was an indication for the exploration of the common bile duct. The present study attempted to assess the validity of these criteria in patients whose common bile duct contained stones. Patients and methods One hundred and seventeen operative cholangiograms undertaken by two surgeons (Mr T. Rowntree and Mr C . G. Marks) during cholecystectomies for calculous disease between September 1971 and December 1974 were examined. Patients with biliary disease other than calculi have been excluded from this series.
Fig. 1. Normal operative cholangiogram after injection of 3 ml of contrast medium showing a normal terminal narrow segment and filling of the duodenum.
Operative technique After the patient had been positioned with the left side raised 15", the abdomen was opened and a Stoke-onTrent cannula inserted into the cystic duct. The cannula was flushed with saline to remove air bubbles from the system. Three films were then taken, at a focal film distance of approximately 100 cm, after the slow injection of 3, 6 and 10ml of Hypaque 25 per cent. The gallbladder was removed whilst the films were being processed, which were then immediately reported by a radiologist. The films were returned to the operating theatre and the decision whether or not to explore the common bile duct was made. Radiological assessment 1. Immediate report. This refers to the radiologist's report made during the operation. 2. After the operation the X-rays were reviewed independently by two radiologists. 3. Subsequently, each cholangiogram was assessed for the five criteria described by Le Quesne (1960).
* Southampton University Hospitals. Present address of C . G . Marks: Radcliffe Infirmary, Oxford. 51
C. G. Marks and F. M. Kelvin
Fig. 2. Abnormal cholangiogram showing reduced density of contrast medium in the duodenum compared with that in the common bile duct, and an irregular terminal narrow segment.
Fig. 3. Cholangiogram showing a normal terminal narrow segment in a common bile duct containing two air bubbles immediately below the catheter tip.
Table I: ACCURACY OF INDIVIDUAL CRITERIA Normal Abnormal group group Overail (52 patients) (40 patients) aCcUracy Criterion No. % No. % (%) Diameter of common I3 25 30 15 75 bile duct > 10 mm No free flow into duodenum measured by length of duodenum filled 5 10 37 ;:}88 First film: < 2 cm Second film: < 7 cm 7 13 32 Abnormal terminal 6 12 35 87.5 88 narrow segment Filling defects 1 2 39 97.5 98 No excess filling of 1 2 13 33 70 intrahepatic ducts
patient’s symptoms or subsequent surgical management. Twenty-eight of these patients underwent exploration of the common bile duct followed by T tube cholangiograms. The presence of calculi was confirmed in 23. The accuracies of the immediate report and of the two radiologists in this group were 80, 84 and 80 per cent respectively. There were 5 negative explorations, all of which were followed by normal T tube cholangiograms. These, together with the 47 cholangiograms reported normal on all three reports, form the 52 patients in the normal group. This is a reasonable assumption in view of the findings of Chapman et al. (1964) that a normal operative cholangiogram is a reliable indication of a normal biliary tree, as shown by subsequent clinical follow-up and intravenous cholangiography.
These criteria were then analysed in the light of the abnormal findings or assumed normality (see below).
Analysis of individual criteria Table I illustrates the accuracy of the individual criteria for the normal and abnormal groups. Each of these criteria will be discussed in turn.
5ll.5
Results Of the patients whose common bile duct was not explored, 25 were excluded from the analysis because either the cholangiograms were technically unsatisfactory or there was lack of agreement in the radiological reports. Forty-five of the remaining 92 patients underwent exploration of the common bile duct. Calculi were found in 40 of the explorations. These 40 patients constitute the abnormal group. To compare the accuracy of the immediate report with that made on review, the X-rays of the first 75 patients were examined without information about the 52
1 . Diameter of the common bile duct If a diameter of 14 mm (Wise, 1962; Chapman et al., 1964) is taken as the upper limit of normal, all 52 normal patients in the present series were included. The upper limit for the diameter of a normal common bile duct has been described at between 10 and 14 mm (Le Quesne, 1960; Wise, 1962; Chapman et al., 1964; McEvedy, 1970). However, in the present series 34 of the 40 abnormal cholangiograms demonstrated a common bile duct diameter of 14 mm or less, and 10 of these were below 10mm. This incidence is lower
Operative cholangiography than that of Hicken and McAllister (1964), who stated that ’at least 40 per cent of the calculi we have removed were extracted from ducts measuring I cm or less in diameter’. We agree with Le Quesne et al. (1959) that there is a wide range of common bile duct diameters in normal cholangiograms, and that a common bile duct diameter of 10 mm is the best dividing point between the two groups, giving an overall accuracy of 75 per cent in the present series. The figure of 10 mm has been used in Table I . 2. Free flow of contrast medium into the duodenum Although initially a subjective assessment, this parameter proved to be accurate. An attempt was then made to quantify normal free flow by measuring the length of duodenum filled with contrast medium. Forty-seven of the 52 normal cholangiograms showed a length of 2 cm or more on the first film (Fig. 1). Only 3 of the abnormal group showed this. On the second film a length of 7 c m or more favoured normality (present in 45 of the 52 normal and in 8 of the 40 abnormal cholangiograms). These measurements were 91 and 84 per cent accurate respectively. Clearly, these measurements are dependent upon using the same volumes of contrast medium (3, 6 and 10ml) and a similar pressure of injection. Other variables such as the degree of duodenal relaxation and the type of anaesthesia may affect these measurements. Nevertheless, in practice, they were found to be very useful. In the abnormal group it was observed that the density of contrast medium in the duodenum was often less than in the common bile duct (Fig. 2). This was not a feature of the normal cholangiogram.
3. A normal terminal narrow segment This showed an overall accuracy of 88 per cent. Within the abnormal group differing appearances were seen. Most commonly the terminal segment was not visualized at all (21 patients). Three cholangiograms showed a small filling defect within it. On 8 occasions the segment filled but with an irregular outline (Fig. 2). This was in marked contrast to the tapering outline seen in the normal group (Fig. 3). Occasionally it was difficult to be sure that filling was normal, especially when there was duodenal superimposition or an excessively long exposure resulted in blurring. 4. Absence offilling defects Table Zshows that this was the most accurate criterion (98 per cent reliable). Filling defects due to calculi were usually characteristic (Fig. 2). Those due to air bubbles (Fig. 3) or to the catheter tip were excluded from the analysis when the cholangiogram clearly indicated either to be the cause. It is essential to use small volumes of a low concentration of contrast medium in order not to obscure small calculi. 5. No excess retrograde filling of the intrahepatic ducts The overall accuracy of this was 70 per cent, because this was the most subjective and therefore the most difficult criterion to assess. This assessment was proved to be the least valuable in the abnormal group.
Table 11: ACCURACY OF COMBINATIONS OF CRITERIA IN THE ABNORMAL GROUP Combined accuracy Combinations of criteria Filling defect(s) in common bile duct No free flow into duodenum Filling defect(s) in common bile duct Abnormal terminal narrow segment No free flow into duodenum Abnormal terminal narrow segment Filling defect(s) in common bile duct N o free flow into duodenum Abnormal terminal narrow segment
No.
%
31
92.5
34
85
33
82.5
33
82.5
Only 13 of the 40 abnormal cholangiograms were considered to show undue intrahepatic filling when compared with the normal cholangiograms.
Discussion The 89 per cent accuracy of operative cholangiograms in predicting stones in the common bile duct is similar to other series, with accuracies of 72 per cent (Wheeler et al., 1970), 73 per cent (McEvedy, 1970) and 92 per cent (Havard, 1970). Both surgeons in the present series found an immediate radiological opinion helpful whenever they had doubts about the interpretation of the cholangiogram, although in many centres the radiologist reports the operative cholangiogram after the completion of the operation. In the normal group all the criteria were of a high degree of accuracy. In the abnormal group three criteria were at least 80 per cent accurate (Table I ) : the presence of a filling defect, the absence of free flow into the duodenum and an abnormal terminal narrow segment. Different combinations of these three criteria were then considered (Table ZI). The best combination was the presence of filling defects and the absence of free flow on the first film, defined as less than 2 c m of contrast medium in the duodenum. Nevertheless, the accuracy of this combination (92.5 per cent) was less than that of filling defects alone (97.5 per cent) in this series. Acknowledgements We are grateful to Dr F. J. Brunton for his help in reviewing the X-rays, and to Mr T. Rowntree for permission to publish details of his patients. We would also like to thank Mr D. Brown for his assistance with the data analysis, and Mrs Alison Wilcox and Mrs Marguerite Benge for their secretarial help. References and LE QUESNE L. P. (1964) Operative cholangiography. An assessment of its reliability in the diagnosis of a normal, stone-free common bile duct. Br. J. Surg. 51, 600-601. HAVARD c . (1970). Operative cholangiography. Br. J. Sltrg. 57, 797-807. HICKEN N. F. and MCALLISTER A. J. (1964) Operative cholangiography as an aid in reducing the incidence of ‘‘overlooked’’ common bile duct stones : a study of 1,293 choledocholithotomies. Srwgery 55, 753-758. CHAPMAN M., CURRY R. c .
53
C. G. Marks and F. M. Kelvin (1960) Discussion of cholangiography. Proc. R. SOC.Med. 53, 852-855. LE QUESNE L. P., WHITESIDE C. G. and HAND B. (1959) The common bile duct after cholecystectomy. Br. Med. J . 1, 329-332. MCEVEDY B. v. (1970) Routine operative cholangiography. Br. J. Sirrg. 57, 211-219. LE QUESNE L. P.
54
and WILLIAMS J. A. (1970) Operative cholangiography. Its effect on the practice of cholecystectomy. Br. Med. J. 4, 161164. WISE R. E. (1962) Intravenous Cholangiography. Springfield, Ill., Thomas. WHEELER M. H., RAKASOOK S.
