- Email: [email protected]
NEW FIBREOPTIC CARDIAC CATHETER
836 is undesirable, since it is associated with severe metabolic bone disease.14 Azathioprine was ineffective in two doubleblind studies,15,16 although reanalysis of the data suggested that it may prolong survival.l’ Penicillamine, studied in large randomised, controlled trials,l,2 showed no beneficial effect. Chlorambucip8 and colchicine’9 slightly improved some of the immunological or biochemical markers of the disease. The improvement in biochemical markers that we noted during UDCA administration is striking and, to our knowledge, has not been reported with other agents or during the spontaneous evolution of the disease. We must emphasise that our study was not a controlled, randomised, double-blind trial and that such a trial is urgently needed before UDCA treatment can be introduced. However, it is unlikely that these results could occur by chance or by some bias in patient selection. The study participants were unselected patients with chronic, stable cholestasis. PBC progresses slowly towards deterioration without consistent trend of improvement with time. In three patients, interruption of UDCA was followed by immediate and clear deterioration of liver function tests, which was reversed by reintroduction of UDCA. Most of our patients were in the early stage of PBC, so we cannot say whether UDCA would be so beneficial in patients with more advanced PBC and more severe hyperbilirubinaemia. We found no evidence of any effect of UDCA therapy on globulin and IgM levels, which suggests use
that humoral immune function was not affected. The rationale for the use of UDCA was to induce qualitative changes in the bile-acid pool. We chose the daily dose of UDCA since preliminary studies had shown that 13-15 mg/kg was well tolerated and produced striking changes in serum bile-acid composition in patients with PBC. The changes in bile-acid composition in our patients were similar to those reported in patients receiving 10-15 mg/kg body weight UDCA for cholesterol gallstones.2o The simultaneous change in bile-acid composition and improvement in liver function that we observed during UDCA therapy further suggests that endogenous bile acids may be partly responsible for hepatic injury occurring in PBC. Our study suggests that long-term UDCA administration might constitute a safe and effective treatment for PBC. The results must be confirmed by a randomised double-blind trial; we are in the process of setting up such a trial. We thank Dr Y. Delage, Dr J. Petit, Dr. T. Andreani, and Dr J. D. Grange for follow-up of patients and Synthelabo France, Departement Robert et Carriere for providing UDCA.
Correspondence should be addressed to R. P., Hopital Saint-Antoine, de Faubourg Saint-Antoine, 75012 Paris, France.
184
rue
REFERENCES
James SP. Primary biliary cirrhosis. N Engl J Med 1985; 312: 1055-57. 2. James OFW D-penicillamine for primary biliary cirrhosis. Gut 1985; 26: 109-13. 3. Roll J. A new treatment for primary biliary cirrhosis? Gastroenterology 1985; 89: 1.
1195-99. 4. Schaffner
F, Bacchin PG, Hutterer F, et al. Mechanism of cholestasis. 4. Structural and biochemical changes in the liver and serum in rats after bile duct ligation. Gastroenterology 1971; 60: 888-97 5. Palmer RH. Bile acids, liver injury, and liver disease. Arch Intern Med 1972; 130: 606-17. 6 Hertz R, Paumgartner G, Preisig R. Inhibition of bile formation by high doses of taurocholate in the perfused rat liver. Scand J Gastroenterol 1975; 11: 741-46. 7. Hatoff DE, Hardison WGM. Bile acids modify alkaline phosphatase induction and bile secretion pressure after bile duct obstruction in the rat. Gastroenterology 1981; 80: 666-72. 8. Schölmerich J, Becher MS, Schmidt K, et al. Influence of hydroxylation and conjugation of bile salts on their membrane-damaging properties—studies on isolated hepatocytes and lipid membrane vesicles. Hepatology 1984; 4: 661-66 9 Hofmann AF. Medical treatment of cholesterol gallstones by bile desaturating agents. Hepatology 1984; 4 (suppl): 199-208.
Methods and Devices NEW FIBREOPTIC CARDIAC CATHETER G. TAYLOR
M. C. PETCH F. C. WELLS
Regional Cardiac Unit, Papworth Hospital, Cambridge CB38RE TRADITIONAL methods of measuring pressures rely on fluidfilled catheters connected to an external pressure transducer. Although cheap and convenient these have disadvantages such as distortion of the pressure waveform through damping and overshoot, delay in transmission of the pressure signal, and interference from extraneous signals such as movement of the catheter or patient. Pressure manometers mounted on the tip of a cardiac catheter overcome these problems but hitherto they have been very expensive, delicate, and difficult to use. We describe here a type of catheter that incorporates the pressure manometer at the tip and transmits the signal through a fibreoptic pathway.
Methods and Findings The standard instrument (fig 1) is a 120 cm 4 F gauge fibreoptic catheter with a pressure transducer mounted on the tip. Only the tip is radio-opaque. The catheter can be passed under fluoroscopy or, more easily, through an 8 F "thin wall" end-hole cardiac catheter. Alternatively, the catheter is available in an 8 F ’Swan Ganz’ format-ie, with a balloon, thermistor, and injectate port. The specifications are as follows:
K, Ohta M, Kanai S. Tauroursodeoxycholate prevents biliary excretion of proteins induced by taurocholate and taurochenodeoxycholate in the rat. Hepatology 1983; 3: 810 (abstr). 11. Kanai S, Kitani K. Glycoursodeoxycholate is as effective as tauroursodeoxycholate (TU) in preventing the taurocholate (TC)-induced cholestasis in the rat. Hepatology 1983; 3: 811 (abstr). 12. Krol T, Kitamura T, Miyai K, Hardison W. Tauroursodeoxycholate reduces ductular proliferation and portal inflammation in bile duct ligated hamsters. Hepatology 1983; 80: 881 (abstr). 13. Poupon RY, Poupon RE, Lebrec D, et al. Mechanisms for reduced hepatic clearance and elevated levels of bile acids in cirrhosis. A study in patients with an end-to-side portacaval shunt. Gastroenterology 1981; 80: 1438-44. 14. Mitchison HC, Watson AJ, Bassendine MF, et al. A pilot double blind controlled trial of prednisolone treatment in primary biliary cirrhosis (PBC). J Hepatol 1986; 3: 527 (abstr). 15. Heathcote J, Ross A, Sherlock S. A prospective controlled trial of azathioprine in primary biliary cirrhosis. Gastroenterology 1976; 70: 656-60. 16. Crowe J, Chnstensen E, Smith M, et al. Azathioprine in primary biliary cirrhosis. Gastroenterology 1980; 78: 1005-10. 17. Christensen E, Neuberger J, Crowe J, et al. Beneficial effect of azathioprine and prediction of prognosis in primary biliary cirrhosis. Final results of an international trial. Gastroenterology 1985; 59: 1084-91. 18. Hoofnagle JH, Davis GL, Schafer DF, et al. Randomized trial of chlorambucil for primary biliary cirrhosis. Gastroenterology 1986; 91: 1327-34 19. Kaplan MM, Ailing DW, Zimmerman H, et al. A prospective trial of colchicine for primary biliary cirrhosis. N Engl J Med 1986; 315: 1448-54. 20. Tint GS, Salen G, Shefer S. Effect of ursodeoxycholic acid and chenodeoxycholic acid on cholesterol and bile acid metabolism. Gastroenterology 1986; 91: 1007-18
10. Kitani
837 excellent correlation between the two systems in the phasic and values and there were no significant differences in any of the measurements of the right or left sided chambers. However, there were minor variations in right atrial pressure between the two systems because of differences in reference zero. In the 4 surgical patients, stable recordings were obtained for periods of up to 24 h. mean
Discussion
Fig. I-The new fibreoptic catheter.
-
The new catheter was compared with a conventional fluid-filled system connected to an E for M multichannel recorder with a Bell and Howell strain gauge transducer in 10 patients who were undergoing diagnostic cardiac catheterisation. Recordings were made with the new and conventional system simultaneously by using two separate catheters or by using the sampling port of the Swan Ganz version of the new catheter during the right heart studies. There were 5 men and 5 women with a mean age of 59-4 years (range 45-68). 4 had ischaemic heart disease, 4 had mitral valve disease,1 had aortic valve disease, and 1 had mixed mitral and aortic valve disease. Right heart catheterisation was done on five occasions with the Swan Ganz technique and left heart catheterisation on five. In most instances the catheter was passed easily but on one occasion, during an attempt to manipulate the 4 F catheter across the aortic valve, the pressure signal disappeared because a small crack in the coating of the fibreoptic path led to leakage of light and hence failure of transmission of the signal. No other complications were observed. 4 other patients (2 mitral valve disease and 2 coronary artery disease) were studied after cardiac surgery, the catheter being inserted directly into the left atrium at the end of the operation. The only difficulty encountered was signal distortion when the catheter tip was against the left atrial wall or near the mitral valve apparatus. Satisfactory pressure signals were obtained in all but one of the patients undergoing cardiac catheterisation. The appearance of the trace and freedom from artefact were remarkable (fig 2). There was
The new catheter system is accurate and reliable during cardiac catheterisation and following open heart surgery. The freedom from artefact is particularly valuable, especially for procedures such as ambulatory and pulmonary artery’ pressure monitoring. The stability of the catheter system should also permit its widespread use for haemodynamic monitoring in intensive-care units. A further advantage of the new catheter is the elimination of the need for a zero reference point. In systems that require a reference point, deviation of the catheter tip from this point (for example, during the measurement of pulmonary artery wedge pressure in the peripheral and posterior part of the lung), or movement of the reference zero (such as occurs when the patient is sat up), have a significant effect on the absolute values of the filling pressures in the heart. The chief disadvantage of catheter-tip manometer systems is their cost. We have not yet compared the new catheter with other catheter tip manometers and cannot therefore comment on its relative performance. However, it is disposable and not too expensive-for example, the Swan Ganz version costs about 50% more than similar thermodilution catheters. ’
Reviews of Books Textbook of Histology F. Geneser.
Copenhagen: Munksgaard.
F. Geneser.
RA == right atnal trace. ECG electrocardiogram. =
The high-frequency artefact on B was caused by hand movement and is not present in the
fibreoptic catheter trace.
Pp 831. DKr 450.
Copenhagen: Munksgaard 1985. Pp 231. DKr 300.
Dr Geneser’s textbook is written for medical students. This is refreshing because many histology texts are rather coy about the nature of their clientele or perhaps attempt to comer too many markets. Geneser is a teacher of medical students and he knows his trade. He has written a large, full, book but the text is readable and easily understood. Apart from the numerous black and white microphotographs and electron micrographs, there are many more explanatory diagrams per page than in most histology books-an excellent feature that reminded me of Garven’s textbook which was so popular many years ago because at last it made histology comprehensible. Indeed many of the diagrams in Geneser are creamed from the best of new and old literature,
including Garven. The subject matter
Fig 2_Right atrial traces obtained with (A) fibreoptic catheter and (B) fluid-îù1ed catheter.
1986.
Color Atlas of Histology
is dealt with in a conventional succeeds in presenting and but Geneser sequence of features gross anatomy, development, integrating function, and biochemistry into the central theme of microscopic structure, so providing a rounded view of the tissue or organ. I could not find in this book any more information than I would like a medical student to know about, or to have understood at some time in his course, though undoubtedly there is much more in the book than a student could be expected to memorise for reproduction for examination purposes. However, the book was written "primarily for education" as the preface says, and as we all know, true education is what remains after we have had time to forget everything we have been told we should learn. That interpretation of education implies that the student needs to
that humoral immune function was not affected. The rationale for the use of UDCA was to induce qualitative changes in the bile-acid pool. We chose the daily dose of UDCA since preliminary studies had shown that 13-15 mg/kg was well tolerated and produced striking changes in serum bile-acid composition in patients with PBC. The changes in bile-acid composition in our patients were similar to those reported in patients receiving 10-15 mg/kg body weight UDCA for cholesterol gallstones.2o The simultaneous change in bile-acid composition and improvement in liver function that we observed during UDCA therapy further suggests that endogenous bile acids may be partly responsible for hepatic injury occurring in PBC. Our study suggests that long-term UDCA administration might constitute a safe and effective treatment for PBC. The results must be confirmed by a randomised double-blind trial; we are in the process of setting up such a trial. We thank Dr Y. Delage, Dr J. Petit, Dr. T. Andreani, and Dr J. D. Grange for follow-up of patients and Synthelabo France, Departement Robert et Carriere for providing UDCA.
Correspondence should be addressed to R. P., Hopital Saint-Antoine, de Faubourg Saint-Antoine, 75012 Paris, France.
184
rue
REFERENCES
James SP. Primary biliary cirrhosis. N Engl J Med 1985; 312: 1055-57. 2. James OFW D-penicillamine for primary biliary cirrhosis. Gut 1985; 26: 109-13. 3. Roll J. A new treatment for primary biliary cirrhosis? Gastroenterology 1985; 89: 1.
1195-99. 4. Schaffner
F, Bacchin PG, Hutterer F, et al. Mechanism of cholestasis. 4. Structural and biochemical changes in the liver and serum in rats after bile duct ligation. Gastroenterology 1971; 60: 888-97 5. Palmer RH. Bile acids, liver injury, and liver disease. Arch Intern Med 1972; 130: 606-17. 6 Hertz R, Paumgartner G, Preisig R. Inhibition of bile formation by high doses of taurocholate in the perfused rat liver. Scand J Gastroenterol 1975; 11: 741-46. 7. Hatoff DE, Hardison WGM. Bile acids modify alkaline phosphatase induction and bile secretion pressure after bile duct obstruction in the rat. Gastroenterology 1981; 80: 666-72. 8. Schölmerich J, Becher MS, Schmidt K, et al. Influence of hydroxylation and conjugation of bile salts on their membrane-damaging properties—studies on isolated hepatocytes and lipid membrane vesicles. Hepatology 1984; 4: 661-66 9 Hofmann AF. Medical treatment of cholesterol gallstones by bile desaturating agents. Hepatology 1984; 4 (suppl): 199-208.
Methods and Devices NEW FIBREOPTIC CARDIAC CATHETER G. TAYLOR
M. C. PETCH F. C. WELLS
Regional Cardiac Unit, Papworth Hospital, Cambridge CB38RE TRADITIONAL methods of measuring pressures rely on fluidfilled catheters connected to an external pressure transducer. Although cheap and convenient these have disadvantages such as distortion of the pressure waveform through damping and overshoot, delay in transmission of the pressure signal, and interference from extraneous signals such as movement of the catheter or patient. Pressure manometers mounted on the tip of a cardiac catheter overcome these problems but hitherto they have been very expensive, delicate, and difficult to use. We describe here a type of catheter that incorporates the pressure manometer at the tip and transmits the signal through a fibreoptic pathway.
Methods and Findings The standard instrument (fig 1) is a 120 cm 4 F gauge fibreoptic catheter with a pressure transducer mounted on the tip. Only the tip is radio-opaque. The catheter can be passed under fluoroscopy or, more easily, through an 8 F "thin wall" end-hole cardiac catheter. Alternatively, the catheter is available in an 8 F ’Swan Ganz’ format-ie, with a balloon, thermistor, and injectate port. The specifications are as follows:
K, Ohta M, Kanai S. Tauroursodeoxycholate prevents biliary excretion of proteins induced by taurocholate and taurochenodeoxycholate in the rat. Hepatology 1983; 3: 810 (abstr). 11. Kanai S, Kitani K. Glycoursodeoxycholate is as effective as tauroursodeoxycholate (TU) in preventing the taurocholate (TC)-induced cholestasis in the rat. Hepatology 1983; 3: 811 (abstr). 12. Krol T, Kitamura T, Miyai K, Hardison W. Tauroursodeoxycholate reduces ductular proliferation and portal inflammation in bile duct ligated hamsters. Hepatology 1983; 80: 881 (abstr). 13. Poupon RY, Poupon RE, Lebrec D, et al. Mechanisms for reduced hepatic clearance and elevated levels of bile acids in cirrhosis. A study in patients with an end-to-side portacaval shunt. Gastroenterology 1981; 80: 1438-44. 14. Mitchison HC, Watson AJ, Bassendine MF, et al. A pilot double blind controlled trial of prednisolone treatment in primary biliary cirrhosis (PBC). J Hepatol 1986; 3: 527 (abstr). 15. Heathcote J, Ross A, Sherlock S. A prospective controlled trial of azathioprine in primary biliary cirrhosis. Gastroenterology 1976; 70: 656-60. 16. Crowe J, Chnstensen E, Smith M, et al. Azathioprine in primary biliary cirrhosis. Gastroenterology 1980; 78: 1005-10. 17. Christensen E, Neuberger J, Crowe J, et al. Beneficial effect of azathioprine and prediction of prognosis in primary biliary cirrhosis. Final results of an international trial. Gastroenterology 1985; 59: 1084-91. 18. Hoofnagle JH, Davis GL, Schafer DF, et al. Randomized trial of chlorambucil for primary biliary cirrhosis. Gastroenterology 1986; 91: 1327-34 19. Kaplan MM, Ailing DW, Zimmerman H, et al. A prospective trial of colchicine for primary biliary cirrhosis. N Engl J Med 1986; 315: 1448-54. 20. Tint GS, Salen G, Shefer S. Effect of ursodeoxycholic acid and chenodeoxycholic acid on cholesterol and bile acid metabolism. Gastroenterology 1986; 91: 1007-18
10. Kitani
837 excellent correlation between the two systems in the phasic and values and there were no significant differences in any of the measurements of the right or left sided chambers. However, there were minor variations in right atrial pressure between the two systems because of differences in reference zero. In the 4 surgical patients, stable recordings were obtained for periods of up to 24 h. mean
Discussion
Fig. I-The new fibreoptic catheter.
-
The new catheter was compared with a conventional fluid-filled system connected to an E for M multichannel recorder with a Bell and Howell strain gauge transducer in 10 patients who were undergoing diagnostic cardiac catheterisation. Recordings were made with the new and conventional system simultaneously by using two separate catheters or by using the sampling port of the Swan Ganz version of the new catheter during the right heart studies. There were 5 men and 5 women with a mean age of 59-4 years (range 45-68). 4 had ischaemic heart disease, 4 had mitral valve disease,1 had aortic valve disease, and 1 had mixed mitral and aortic valve disease. Right heart catheterisation was done on five occasions with the Swan Ganz technique and left heart catheterisation on five. In most instances the catheter was passed easily but on one occasion, during an attempt to manipulate the 4 F catheter across the aortic valve, the pressure signal disappeared because a small crack in the coating of the fibreoptic path led to leakage of light and hence failure of transmission of the signal. No other complications were observed. 4 other patients (2 mitral valve disease and 2 coronary artery disease) were studied after cardiac surgery, the catheter being inserted directly into the left atrium at the end of the operation. The only difficulty encountered was signal distortion when the catheter tip was against the left atrial wall or near the mitral valve apparatus. Satisfactory pressure signals were obtained in all but one of the patients undergoing cardiac catheterisation. The appearance of the trace and freedom from artefact were remarkable (fig 2). There was
The new catheter system is accurate and reliable during cardiac catheterisation and following open heart surgery. The freedom from artefact is particularly valuable, especially for procedures such as ambulatory and pulmonary artery’ pressure monitoring. The stability of the catheter system should also permit its widespread use for haemodynamic monitoring in intensive-care units. A further advantage of the new catheter is the elimination of the need for a zero reference point. In systems that require a reference point, deviation of the catheter tip from this point (for example, during the measurement of pulmonary artery wedge pressure in the peripheral and posterior part of the lung), or movement of the reference zero (such as occurs when the patient is sat up), have a significant effect on the absolute values of the filling pressures in the heart. The chief disadvantage of catheter-tip manometer systems is their cost. We have not yet compared the new catheter with other catheter tip manometers and cannot therefore comment on its relative performance. However, it is disposable and not too expensive-for example, the Swan Ganz version costs about 50% more than similar thermodilution catheters. ’
Reviews of Books Textbook of Histology F. Geneser.
Copenhagen: Munksgaard.
F. Geneser.
RA == right atnal trace. ECG electrocardiogram. =
The high-frequency artefact on B was caused by hand movement and is not present in the
fibreoptic catheter trace.
Pp 831. DKr 450.
Copenhagen: Munksgaard 1985. Pp 231. DKr 300.
Dr Geneser’s textbook is written for medical students. This is refreshing because many histology texts are rather coy about the nature of their clientele or perhaps attempt to comer too many markets. Geneser is a teacher of medical students and he knows his trade. He has written a large, full, book but the text is readable and easily understood. Apart from the numerous black and white microphotographs and electron micrographs, there are many more explanatory diagrams per page than in most histology books-an excellent feature that reminded me of Garven’s textbook which was so popular many years ago because at last it made histology comprehensible. Indeed many of the diagrams in Geneser are creamed from the best of new and old literature,
including Garven. The subject matter
Fig 2_Right atrial traces obtained with (A) fibreoptic catheter and (B) fluid-îù1ed catheter.
1986.
Color Atlas of Histology
is dealt with in a conventional succeeds in presenting and but Geneser sequence of features gross anatomy, development, integrating function, and biochemistry into the central theme of microscopic structure, so providing a rounded view of the tissue or organ. I could not find in this book any more information than I would like a medical student to know about, or to have understood at some time in his course, though undoubtedly there is much more in the book than a student could be expected to memorise for reproduction for examination purposes. However, the book was written "primarily for education" as the preface says, and as we all know, true education is what remains after we have had time to forget everything we have been told we should learn. That interpretation of education implies that the student needs to