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Direct Pancreatic Function Test (Duodenal Intubation) in the Diagnosis of Chronic Pancreatitis
GASTROENTEROLOGY 1986;90:799-803
CORRESPONDENCE Readers are encouraged to write Letters to the Editor concerning articles that have been published in GASTROENTEROLOGY. Short, general comments are also considered, but use of the Correspondence Section for publication of original data in preliminary form is not encouraged. Letters should be typewritten double-spaced and submitted in triplicate.
Direct Pancreatic Function Test (Duodenal Intubation) in the Diagnosis of Chronic Pancreatitis Dear Sir: I was very interested to read the recent progress article by Niederau and Grendell (i), and I would like to make a few comments on the direct pancreatic function test, the diagnostic value of which was strongly questioned. In our clinic, duodenal intubation is one of the investigations usually carried out on patients with chronic pancreatitis (CP). and our experience indicates that in a significant number of patients, mainly in those with early CP, it may be very useful. Our method involves a prolonged (90 min) intravenous infusion of maximal doses of secretin and caerulein (2). We have shown that this method of pancreatic stimulation has a very high sensitivity in detecting pancreatic insufficiency-even mild insufficiency (2,3). To date, we have studied 140 patients with CPo The diagnosis of CP was based on clinical history and was confirmed, at the time of study or in a subsequent follow-up, by one or more of the following criteria: pancreatic calcification, histologic findings, typical ductal alterations at endoscopic retrograde pancreatography, and pancreatic insufficiency in at least two consecutive studies (minimum interval between consecutive studies = 1 year). The sensitivity of the direct pancreatic function test was 97% (the specificity was 98%). In the vast majority of patients (-80%) ultrasound and endoscopic retrograde pancreatography were also carried out, and the sensitivity of these two techniques was lower, i.e., -70% and 90%, respectively. Our experience with computed tomography has so far involved fewer patients; however, the results obtained suggest that its sensitivity is similar to that of ultrasound. It is interesting to note that if we consider only those patients with earlier forms of CP, i.e., no calcification, steatorrhea, or diabetes (-40% of the total), the sensitivity of duodenal intubation always remains above 90%, whereas that of ultrasound and retrograde pancreatography (but above all ultrasound) further decrease. Thus, these observations clearly indicate that the diagnostic value of the direct pancreatic function test (at least by our method) is greater than that of ultrasound and retrograde pancreatography in CP, even in earlier forms of the disease which are, as is well known, the most difficult to diagnose. To my knowledge, there are no studies in literature showing that anyone of the new imaging techniques has a greater sensitivity than the direct pancreatic function tests in the diagnosis of early or mild CPo In the conclusion of their article, Niederau and Grendell emphasize that many clinical centers in the United States do not use any direct test of pancreatic function in the diagnostic approach to CPo I would like to know what they do in these centers to confirm clinical suspicion of CP, when ultrasound and tubeless pancreatic function tests are normal and retrograde pancreatography is also normal or doubtful (indeed, such cases are not infrequent). In my opinion, the fact that duodenal intubation is not performed in many centers does not indicate that the diagnostic value of this test is questionable, but largely arises from the practical drawbacks of the procedure. I would like to mention that there are several centers in Europe, well known in the field of pancreatitis, where, despite the development of the new imaging techniques, duodenal intubation continues to be regularly used in most patients with CPo
In conclusion, our own experience leads us to be less drastic than Niederau and Grendell about the value of the direct pancreatic function test in the diagnosis of CPo Although this test may not be necessary for the diagnosis of advanced CP, it is very important for the diagnosis of early or mild CPo There is no doubt that modern imaging techniques have modified the diagnostic approach to CP in recent years, but I think that this is mainly for advanced CPo In my opinion, one of the greatest practical advantages of these techniques (perhaps the most important) is that they have made the diagnosis of CP complications much easier (for example, pancreatic cysts). thereby also bringing about a marked improvement in the therapeutic approach. Finally, I would like to point out that in Table 5 of the progress article, the data concerning a study from our laboratory on the fluorescein dilaurate test (4) have been exchanged with those of another study (5). I feel it is important to point this out, as in our study the sensitivity of this tubeless test in mild CP is considerably lower than that found in the other study. LUCIO GULLO, M.D.
Institute of Clinical Medicine and Gastroenterology St. Orsola Hospital 40138 Bologna, Italy
JH. Diagnosis of chronic pancreatitis. Gastroenterology 1985;88:1973-95. Gullo L, Costa PL, Fontana G, Labo G. Investigation of exocrine pancreatic function by continuous infusion of caerulein and secretin in normal subjects and in chronic pancreatitis. Digestion 1976;14:97-107. Gullo L, Costa PL, Labo G. A comparison between injection and infusion of pancreatic stimulants in the diagnosis of exocrine pancreatic insufficiency. Digestion 1978;18:64-9. Ventrucci M, Gullo L, Daniele C, Priori P, Labo G. Pancreolauryl test for pancreatic exocrine insufficiency. Am J GastroenteroI1983;73:806-9. Stock KP, Schenk 1. Schmack B, Domschke W. Funktions"Screening" des exokrinen Pankreas. FDL- , NBT-PABA-Test, Stuhl-Chymotrypsinbestimmung im Vergleich mit dem Sekretin-Pankreozymin-Test. Dtsch Med Wochenschr 1981; 106:983-7.
1. Niederau C, Grendell
2.
3. 4. 5.
Reply. In our review of the diagnosis of chronic pancreatitis (i), we did not dispute the relatively high accuracy of direct tests of secretory capacity following duodenal intubation such as the secretin-caerulein test used by Gullo and his colleagues. In fact, we included this as an option in the figure describing our recommended diagnostic approach to this disease. The extremely high sensitivity and specificity reported by Gullo et al. (2,3), however, is considerably better than the overall experience with this type of test, as discussed in our review. We still believe that, as we stated (1), the role of the direct function test is uncertain and that for most patients a direct test of pancreatic function is no longer required for the diagnosis of chronic pancreatitis. The disuse into which direct secretory tests have fallen in the United States does not necessarily reflect a lack of appreciation of their diagnostic accuracy but rather an assessment that, for most patients in clinical practice, the discomfort, cost, and difficulty of performing and standardizing such tests are
CORRESPONDENCE Readers are encouraged to write Letters to the Editor concerning articles that have been published in GASTROENTEROLOGY. Short, general comments are also considered, but use of the Correspondence Section for publication of original data in preliminary form is not encouraged. Letters should be typewritten double-spaced and submitted in triplicate.
Direct Pancreatic Function Test (Duodenal Intubation) in the Diagnosis of Chronic Pancreatitis Dear Sir: I was very interested to read the recent progress article by Niederau and Grendell (i), and I would like to make a few comments on the direct pancreatic function test, the diagnostic value of which was strongly questioned. In our clinic, duodenal intubation is one of the investigations usually carried out on patients with chronic pancreatitis (CP). and our experience indicates that in a significant number of patients, mainly in those with early CP, it may be very useful. Our method involves a prolonged (90 min) intravenous infusion of maximal doses of secretin and caerulein (2). We have shown that this method of pancreatic stimulation has a very high sensitivity in detecting pancreatic insufficiency-even mild insufficiency (2,3). To date, we have studied 140 patients with CPo The diagnosis of CP was based on clinical history and was confirmed, at the time of study or in a subsequent follow-up, by one or more of the following criteria: pancreatic calcification, histologic findings, typical ductal alterations at endoscopic retrograde pancreatography, and pancreatic insufficiency in at least two consecutive studies (minimum interval between consecutive studies = 1 year). The sensitivity of the direct pancreatic function test was 97% (the specificity was 98%). In the vast majority of patients (-80%) ultrasound and endoscopic retrograde pancreatography were also carried out, and the sensitivity of these two techniques was lower, i.e., -70% and 90%, respectively. Our experience with computed tomography has so far involved fewer patients; however, the results obtained suggest that its sensitivity is similar to that of ultrasound. It is interesting to note that if we consider only those patients with earlier forms of CP, i.e., no calcification, steatorrhea, or diabetes (-40% of the total), the sensitivity of duodenal intubation always remains above 90%, whereas that of ultrasound and retrograde pancreatography (but above all ultrasound) further decrease. Thus, these observations clearly indicate that the diagnostic value of the direct pancreatic function test (at least by our method) is greater than that of ultrasound and retrograde pancreatography in CP, even in earlier forms of the disease which are, as is well known, the most difficult to diagnose. To my knowledge, there are no studies in literature showing that anyone of the new imaging techniques has a greater sensitivity than the direct pancreatic function tests in the diagnosis of early or mild CPo In the conclusion of their article, Niederau and Grendell emphasize that many clinical centers in the United States do not use any direct test of pancreatic function in the diagnostic approach to CPo I would like to know what they do in these centers to confirm clinical suspicion of CP, when ultrasound and tubeless pancreatic function tests are normal and retrograde pancreatography is also normal or doubtful (indeed, such cases are not infrequent). In my opinion, the fact that duodenal intubation is not performed in many centers does not indicate that the diagnostic value of this test is questionable, but largely arises from the practical drawbacks of the procedure. I would like to mention that there are several centers in Europe, well known in the field of pancreatitis, where, despite the development of the new imaging techniques, duodenal intubation continues to be regularly used in most patients with CPo
In conclusion, our own experience leads us to be less drastic than Niederau and Grendell about the value of the direct pancreatic function test in the diagnosis of CPo Although this test may not be necessary for the diagnosis of advanced CP, it is very important for the diagnosis of early or mild CPo There is no doubt that modern imaging techniques have modified the diagnostic approach to CP in recent years, but I think that this is mainly for advanced CPo In my opinion, one of the greatest practical advantages of these techniques (perhaps the most important) is that they have made the diagnosis of CP complications much easier (for example, pancreatic cysts). thereby also bringing about a marked improvement in the therapeutic approach. Finally, I would like to point out that in Table 5 of the progress article, the data concerning a study from our laboratory on the fluorescein dilaurate test (4) have been exchanged with those of another study (5). I feel it is important to point this out, as in our study the sensitivity of this tubeless test in mild CP is considerably lower than that found in the other study. LUCIO GULLO, M.D.
Institute of Clinical Medicine and Gastroenterology St. Orsola Hospital 40138 Bologna, Italy
JH. Diagnosis of chronic pancreatitis. Gastroenterology 1985;88:1973-95. Gullo L, Costa PL, Fontana G, Labo G. Investigation of exocrine pancreatic function by continuous infusion of caerulein and secretin in normal subjects and in chronic pancreatitis. Digestion 1976;14:97-107. Gullo L, Costa PL, Labo G. A comparison between injection and infusion of pancreatic stimulants in the diagnosis of exocrine pancreatic insufficiency. Digestion 1978;18:64-9. Ventrucci M, Gullo L, Daniele C, Priori P, Labo G. Pancreolauryl test for pancreatic exocrine insufficiency. Am J GastroenteroI1983;73:806-9. Stock KP, Schenk 1. Schmack B, Domschke W. Funktions"Screening" des exokrinen Pankreas. FDL- , NBT-PABA-Test, Stuhl-Chymotrypsinbestimmung im Vergleich mit dem Sekretin-Pankreozymin-Test. Dtsch Med Wochenschr 1981; 106:983-7.
1. Niederau C, Grendell
2.
3. 4. 5.
Reply. In our review of the diagnosis of chronic pancreatitis (i), we did not dispute the relatively high accuracy of direct tests of secretory capacity following duodenal intubation such as the secretin-caerulein test used by Gullo and his colleagues. In fact, we included this as an option in the figure describing our recommended diagnostic approach to this disease. The extremely high sensitivity and specificity reported by Gullo et al. (2,3), however, is considerably better than the overall experience with this type of test, as discussed in our review. We still believe that, as we stated (1), the role of the direct function test is uncertain and that for most patients a direct test of pancreatic function is no longer required for the diagnosis of chronic pancreatitis. The disuse into which direct secretory tests have fallen in the United States does not necessarily reflect a lack of appreciation of their diagnostic accuracy but rather an assessment that, for most patients in clinical practice, the discomfort, cost, and difficulty of performing and standardizing such tests are