Laboratory Animals (1979) 13, 15-16
15
Catheterization of the left cardiac ventricle of the rat S. M. SMITH,
J. H. MYERS & H. M. KAPLAN
School of Medicine, Southern Illinois University, Carbondale, Illinois 62901, United States of America Summary A simple procedure is described of catheterizing left ventricle of the anaesthetized rat.
4A
Although there are numerous reports on cardiac catheteriz.ation (Popovic & Popovic, 1960; Nakhjavan, 1972; Platts, Wilson & Shaw, 1972; Warren & Ledingham, 1972; Manohar, Kumar, Bhargava, Nigam & Tyagi, 1973; Beaz.ell, Garner & Laks, 1975; Brandstaetter & Terkel, 1977), there is apparently no published description of left ventricular catheterization in the rat. Procedures for other animals cannot be extrapolated to the rat, and techniques for right ventricle catheterization are not applicable because little or no resistance is encountered in catheter transit from the right atrium. A procedure is described below for insertion of a catheter into the left ventricle of rats weighing at least 250 g. This is modified from a method developed for rats in which the aorta is cannulated (Popovic & Popovic, 1960). A suitable catheter is polyethylene tubing ('Intramedic' PE-50, internal diameter O· 58 mm, external 0·965 mm; Clay Adams Co., 299 Webro Road, Parsippany, New J~rsey 07054, USA). The tubing retains a curvature from being wound on a spool. A 40 em strip of tubing is cut from the spool, and the 'clockwise' end flared by heating. A 45° angle bevel is then cut on the 'counter-clockwise' end. A stripe is inscribed on the catheter with a felt-tipped marker 48 mm from the bevel end to act as a convenient guide to the distance traversed in the vessel by the catheter. The catheter is kinked to about a 3 ° angle, 4 mm from the bevel and in the direction of the curvature of the tubing (Fig. I A). A 1 in 100 silicone solution ('Siliclad' silicone concentrate; Clay Adams Co.) is prepared and the catheter immersed in it, at the same time drawing silicone by hypodermic syringe through the bore of the catheter. The catheter is then rinsed in distilled water and placed in an oven at 80°C for 30 min to 'set' the silicone. The catheter may be sterilized in a solution such as benzalkonium chloride ('Zephiran'; Winthrop Laboratories, Des Plaines, Illinois 60018, USA) for up to 12 h, but may soften excessively if immersed for longer. In an anaesthetized rat in dorsal recumbency, a midline incision is made from 1 cm caudal to the Received 8 May 1978. Accepted 24 July 1978.
r-m
the
Fig. 1. Rat cardiac catheter. A. Detail of catheter tip. 8. Surgical approach.
mandibular symphysis to a point just cranial to the sternal manubrium (Fig. IB). The right common carotid artery is isolated and ligated with OO-silk suture just caudal to its bifurcation. A small bulldog clamp is placed around the artery as close as possible to the sternal manubrium and a 2nd, loose, ligature tied immediately cranial to the bulldog clamp. With iris scissors pointing towards the heart an oblique cut is made in the ventral surface of the artery 1 cm cranial to the clamp. The catheter is inserted, bevel up, into the artery and toward the heart with its curvature directed toward the midline. The loose ligature cranial
Smith, Myers & Kaplan
16
to the clamp is tightened with a half-hitch knot and the catheter is advanced after removing the bulldog clamp until resistance is felt at the aortic semilunar valve. This is about 2 mm before the surface-inscribed stripe enters the artery. To avoid damage if resistance is sensed, the catheter should be slowly withdrawn 2-3 mm, rotated 1/4-1/2 turn clockwise and advanced again toward the ventricle. Proof of entry may be monitored by observing the ventricular pressure wave transmitted via a transducer to a channel recorder, a procedure which eliminates the need for the fluoroscopy commonly used in other species to test cardiac
References Beazell, J., Garner, D. & Laks, M. M. (1975). Preparation for repeated study of left ventricular function in the conscious dog. Journal of Applied Physiology 38, 934936. Brandstaetter, J. & Terkel, J. (1977). Chronic double lumen intravenous cannulation of the unrestrained rat. Laboratory A nimal Science 27,999-1003. Manohar, M., Kumar, R., Bhargava, A. K. Nigam, J. M. & Tyagi, R. P. S. (1973). Cardiac catheterization in unanesthetized cattle. Journal of the American Veterinary Medical Association 163.351-354.
Katheterisieren
der linken Herzkammer
S. M. SMITH,
J. H. MYERS
bei Ratten
& H. M. KAPLAN
Zusammenfassung Beschrieben wfrd eine einfache Methode fur das Katheterisieren der linken Herzkammer bei narkotisierten Ratten.
entry. After checking the pOSition of the stripe to ensure that the catheter is still correctly placed, the ligature is firmly tied by converting the half-hitch to a square knot. For 'chronic' work, the catheter is brought out to the surface through the skin of the scalp by pushing the catheter between the eye and ear as described by Popovic & Popovic (1960). The catheter stays patent for up to 48 h if first filled (0·3 mt) with heparinized saline (1000 USP units in 4 ml of 0·9% w/v sodium chloride solution). We have catheterized more than 50 rats in this way with no adverse reaction.
Nakhjavan, F. K. (1972). New technic for measurement of physiological parameters in conscious animals. Journal of Applied Physiology 32, 145-146. Platts, R. G., Wilson, P. & Shaw, K. M. (1972). Design for a chronic right ventricular catheter for dogs. Laboratory Animal Science 22,900-903. Popovic, V. & Popovic, P. (1960). Permanent cannulation of aorta and vena cava in rats and ground squirrels. Journal of Applied Physiology 15,727-728. Warren, D. J. & Ledingham, J. G. G. (1972). Chronic left atrial catheterization in the rabbit. Pfliigers Archiv fiir die gesamte Physiologie des Menschen und der Tiere 335, 167-172.
15
Catheterization of the left cardiac ventricle of the rat S. M. SMITH,
J. H. MYERS & H. M. KAPLAN
School of Medicine, Southern Illinois University, Carbondale, Illinois 62901, United States of America Summary A simple procedure is described of catheterizing left ventricle of the anaesthetized rat.
4A
Although there are numerous reports on cardiac catheteriz.ation (Popovic & Popovic, 1960; Nakhjavan, 1972; Platts, Wilson & Shaw, 1972; Warren & Ledingham, 1972; Manohar, Kumar, Bhargava, Nigam & Tyagi, 1973; Beaz.ell, Garner & Laks, 1975; Brandstaetter & Terkel, 1977), there is apparently no published description of left ventricular catheterization in the rat. Procedures for other animals cannot be extrapolated to the rat, and techniques for right ventricle catheterization are not applicable because little or no resistance is encountered in catheter transit from the right atrium. A procedure is described below for insertion of a catheter into the left ventricle of rats weighing at least 250 g. This is modified from a method developed for rats in which the aorta is cannulated (Popovic & Popovic, 1960). A suitable catheter is polyethylene tubing ('Intramedic' PE-50, internal diameter O· 58 mm, external 0·965 mm; Clay Adams Co., 299 Webro Road, Parsippany, New J~rsey 07054, USA). The tubing retains a curvature from being wound on a spool. A 40 em strip of tubing is cut from the spool, and the 'clockwise' end flared by heating. A 45° angle bevel is then cut on the 'counter-clockwise' end. A stripe is inscribed on the catheter with a felt-tipped marker 48 mm from the bevel end to act as a convenient guide to the distance traversed in the vessel by the catheter. The catheter is kinked to about a 3 ° angle, 4 mm from the bevel and in the direction of the curvature of the tubing (Fig. I A). A 1 in 100 silicone solution ('Siliclad' silicone concentrate; Clay Adams Co.) is prepared and the catheter immersed in it, at the same time drawing silicone by hypodermic syringe through the bore of the catheter. The catheter is then rinsed in distilled water and placed in an oven at 80°C for 30 min to 'set' the silicone. The catheter may be sterilized in a solution such as benzalkonium chloride ('Zephiran'; Winthrop Laboratories, Des Plaines, Illinois 60018, USA) for up to 12 h, but may soften excessively if immersed for longer. In an anaesthetized rat in dorsal recumbency, a midline incision is made from 1 cm caudal to the Received 8 May 1978. Accepted 24 July 1978.
r-m
the
Fig. 1. Rat cardiac catheter. A. Detail of catheter tip. 8. Surgical approach.
mandibular symphysis to a point just cranial to the sternal manubrium (Fig. IB). The right common carotid artery is isolated and ligated with OO-silk suture just caudal to its bifurcation. A small bulldog clamp is placed around the artery as close as possible to the sternal manubrium and a 2nd, loose, ligature tied immediately cranial to the bulldog clamp. With iris scissors pointing towards the heart an oblique cut is made in the ventral surface of the artery 1 cm cranial to the clamp. The catheter is inserted, bevel up, into the artery and toward the heart with its curvature directed toward the midline. The loose ligature cranial
Smith, Myers & Kaplan
16
to the clamp is tightened with a half-hitch knot and the catheter is advanced after removing the bulldog clamp until resistance is felt at the aortic semilunar valve. This is about 2 mm before the surface-inscribed stripe enters the artery. To avoid damage if resistance is sensed, the catheter should be slowly withdrawn 2-3 mm, rotated 1/4-1/2 turn clockwise and advanced again toward the ventricle. Proof of entry may be monitored by observing the ventricular pressure wave transmitted via a transducer to a channel recorder, a procedure which eliminates the need for the fluoroscopy commonly used in other species to test cardiac
References Beazell, J., Garner, D. & Laks, M. M. (1975). Preparation for repeated study of left ventricular function in the conscious dog. Journal of Applied Physiology 38, 934936. Brandstaetter, J. & Terkel, J. (1977). Chronic double lumen intravenous cannulation of the unrestrained rat. Laboratory A nimal Science 27,999-1003. Manohar, M., Kumar, R., Bhargava, A. K. Nigam, J. M. & Tyagi, R. P. S. (1973). Cardiac catheterization in unanesthetized cattle. Journal of the American Veterinary Medical Association 163.351-354.
Katheterisieren
der linken Herzkammer
S. M. SMITH,
J. H. MYERS
bei Ratten
& H. M. KAPLAN
Zusammenfassung Beschrieben wfrd eine einfache Methode fur das Katheterisieren der linken Herzkammer bei narkotisierten Ratten.
entry. After checking the pOSition of the stripe to ensure that the catheter is still correctly placed, the ligature is firmly tied by converting the half-hitch to a square knot. For 'chronic' work, the catheter is brought out to the surface through the skin of the scalp by pushing the catheter between the eye and ear as described by Popovic & Popovic (1960). The catheter stays patent for up to 48 h if first filled (0·3 mt) with heparinized saline (1000 USP units in 4 ml of 0·9% w/v sodium chloride solution). We have catheterized more than 50 rats in this way with no adverse reaction.
Nakhjavan, F. K. (1972). New technic for measurement of physiological parameters in conscious animals. Journal of Applied Physiology 32, 145-146. Platts, R. G., Wilson, P. & Shaw, K. M. (1972). Design for a chronic right ventricular catheter for dogs. Laboratory Animal Science 22,900-903. Popovic, V. & Popovic, P. (1960). Permanent cannulation of aorta and vena cava in rats and ground squirrels. Journal of Applied Physiology 15,727-728. Warren, D. J. & Ledingham, J. G. G. (1972). Chronic left atrial catheterization in the rabbit. Pfliigers Archiv fiir die gesamte Physiologie des Menschen und der Tiere 335, 167-172.
