Indian Journal of Thoracic and Cardiovascular Surgery 1989-90: 6:86-88

Double Knot of Swan Ganz Catheter K MURALIDHAR S MANIMALA RAO B BHASKAR RAO P RAJAt;OPAL

ABSTRACT: Intracardiac knot formation at the distal end of a pulmonary artery catheter in a patient who underwent mitral valve replacement is described. The fluoroscopic methods used to undo the knot were futile. The catheter was finally pulled out after sustained traction which reduced the size of the knot.

KEY WORD: pulmonary artery catheter

INTRODUCTION

The introduction of pulmonary artery catheter (quadruple lumen Swan Ganz thermodilution catheter) has contributed to the care of the critically ill and the anaesthetic management of the high risk patient. However, a variety of complications can and do occur which range from minor sequelae without clinical significance to those with fatal outcome.

We describe one such complication which occured in a patient who underwent an otherwise uneventful mitral valve replacement.

CASE REPORT

A 17-year-old male patient was admitted with severe mitral regurgitation and severe pulmonary artery hypertension for mitral valve replacement.

From the Department of Anaesthesiology and Cardio- thoracic and Vascular Surgery, Nizam's Institute of Medical Sciences, Hyderabad, India.

Address for correspondence : Dr K Muralidhar, Depart- ment of Anaesthesiology, BN Birla Heart Research Institute, 1/1, Library Avenue. Calcutta 700 027, India.

He was anaesthetised. The right internal jugular vein (RIJV) was identified with the patient in Trende- lenberg position and head turned to the left. An t8 G thin-walled 5 cm teflon catheter (Vasofix) was placed in the RIJV and threaded down the vessel for a short distance. Flexible end of the guidewire was passed through the 18 G catheter into the superior vena cava (SVC) and the 18 G catheter was removed. The dilator set consisting of an internal vessel dilator and an external 10 G catheter sheath was passed into the RIJV over the guidewire by twisting motion until the catheter sheath was in the SVC. Then a 7 F quadruple lumen pulmonary artery balloon floatation catheter (PAC) which was previously filled with flushing fluid and attached to a transducer was passed through the sheath into the SVC. Further passage of the catheter was aided by transduction and wave form analysis on the oscilloscope. The right atrium (RA) and. right ventricle (RV) were entered easily but the pul- monary artery was entered with some difficulty and a satisfactory pulmonary capillary wedge position was obtained at 75 cm mark on the catheter at the skin.

The patient underwent mitral valve replacement uneventfully and was extubated after overnight ventilatory support. At the end of 48 hours, an attempt

Knotted catheter 87

was made to remove the PAC. It could be withdrawn upto 25 cm mark and with some resistance upto 15 cm mark; but beyond this it was not possible to withdraw it. The chest x-ray at this moment showed a knot of the PAC (Fig.l) which was freely mobile in the right atrium and SVC. Under fluoroscopic control, several futile attempts were made to untie the knot. The methods included manipulation, hooking the loop of the knot with a pigtail catheter and left coronary artery catheter (both passed via the right femoral vein into the right atrium).

pressure (PCWP) is feasible without fluoroscopy. The monitoring of pulmonary artery pressure and cardiac output using a Swan Ganz catheter is advocated after mitral and aortic valve replacements, more so if pulmonary arterial hypertension or myocardial failure is present. Reports of intracardiac knotting of the PAC have been infrequent. The knots may take the form of free, single or double knots in the catheter or more ominously, may incorporate intracardiac structures such as papillary muscle, chordae tendinae or the lead from the cardiac pace- maker z3'4. The formation of a double knot, i.e., a knot within a knot with figure of 8 configuration (Figs 2&3) which occured in our patient is not

Fig.1 The knotted Swan Ganz catheter in the superior vena cava

Ultimately by continued gentle traction of the proximal end of the PAC, it was noticed fluoro- scopically that the knot was becoming tightened and diminutive in size and then with a little force, it could be completely withdrawn out of the RIJV through the initial venepuncture site. After 10 minutes of manual compression at the puncture site bleeding stopped. A repeat chest radiograph showed mild surgical emphysema but no haemothorax. Further course of the patient was uneventful.

DISCUSSION

With the introduction of the flow-directed, balloon-tipped catheter, haemodynamic irivestiga- tion of the severely ill patient has become so greatly facilitated that rapid and reliable determination of the right ventricular pressure (RVP), pulmonary artery pressure (PAP) and pulmonary capillary wedge

Fig.2 Distal end of the knotted pulmonary artery catheter immediately after withdrawal

reported so far to our knowledge. We employed fluoroscopic methods to untie the knot without success. Ultimately continued traction helped to diminish the size of the knot enough for the catheter to be pulled through the original venepuncture site of the RIJV. Thijs et al have described double knot formation at two places in the distal end which

88 Muralidhar et al

Acknowledgement

The authors wish to thank Professor K Subba Rao, Director of the Institute for permitting to publish this case report.

Fig.3 The knot showing a figure of 8 configuration

could be removed after a venotomy under anaes- thesia 2. Previous reports describe the use of an 8 French Des i le t s -Hoffman sheath and 14 French catheter from a biliary stent kit (Cook) to tighten the knotted catheter and allow removal from an internal jugular vein 5'6. Ibert et al have described a case of knotting of a Swan Ganz catheter in the pulmonary artery which gave erroneous values of cardiac output but could be subsequently removed easily without complicat ion 7.

References

KEEFER RJ, BARASH PG. lntracardiac knotting: pul- monal 3' artery catheterisation. In: Casey D Blitt, ed. Monitoring in Anaesthesia and Critical Care Medicine. New York: Churchill Livingstone, 1985: 205-7.

2. THUS LG, VEN HENKELEM HA, BRONSVELD W e t al. Double intracardiac knotting of Swan Ganz catheter. Br J Anaesth 1981; 53: 672.

3. SCHWARTZ KV, GARCIA FG. Entanglement of Swan G anz catheter around an intracardiac structure. JAMA 1977; 237:1198.

4. LIP1, He t al. Intracardiac knotting of a flow directed balloon catheter. New Engl J Med 1974; 184: 220.

5. KUMAR PK, YANS J, KWATRA M, LOESCI-1 DM, VITU- RAWONG V. Removal of a knotted flow--directed catheter by a nonsurgical method. Ann Intern Med 1980; 92: 629--40.

6. DACH JL, GALPUT DL, LEPAGE JR. The knotted Swan Ganz catheter: new solution to a vexing problem. Am J Radiol 1981; 137: 1274-5.

7, IBERT TJ, JAYAGOPAL SG. Knotting of the Swan Ganz catheter in the pulmonary artery. Chest 1983; 4:711.