Publication Note

The abstract of this article had been presented at the 16th annual meeting of World Congress of the World Society of Cardio-Thoracic Surgeons in Ottawa/CANADA,17-20/08/2006.

Introduction

Pulmonary artery catheters are widely used to manage critically all patients but can be associated with various complications(₁). Since its introduction in 1970, the pulmonary artery catheter (PAC) has been widely used in perioperative and intensive care patient management(₁,₂). Entrapment of a PAC (Swan-Ganz catheter) in the heart, vena cava or pulmonary artery is a very rare and serious complication that may lead to life-threatening complications such as cardiac rupture, pulmonary artery rupture, cardiac tamponade, among others, if not recognized and treated early(₃).American Association of Anesthesiologists reported that major complication rate is 0.1 to 0.5%(₄).An European report including 5306 cardiac operations with PAC, had a major complication rate of 0.07%(₄). During the 6 years period our complication rate was 0.1% for 2310 PAC insertion and it was correlated with recent literature.

Material And Methods

During the 6 years between 2001 January and 2006 December, totally 2310 PACs were inserted to patients going under cardiovascular operations. Insertions were performed after intubation for endotracheal general anesthesia to control the patient peroperatively and early period postoperatively. The procedure was made with sedation and local anesthesia in the patients needing long-term postop follow-up at Intensive Care Unit(ICU).Before all insertions; ECG, invasive arterial pressure, peripheral oxygen saturation monitorizations and arterial blood gas analysis were made.Seldinger technique was used for cannulation and the first choice was right internal jugular vein approach. Pulmonary artery catheter(Edwards Lifesciences,Swan-Ganz, True Size Monitoring Catheter,7F,110cm) was advanced to right atrium and inflated with 1.5cc air under pressure monitoring and advanced to right ventricle. Catheter advanced 50cm and balloon deflated when wedge pressure was recorded. Except arrhytmias as ventricular extrasystoly not needing medical therapy, there wasn't any problem with pulmonary pressure monitoring and taking blood from the distal lumen. In 3(%0.1) cases resistance to removal of PAC was seen. Pressure tracing showed that catheters are at right atrial level in these cases.

Clinical features of these patients are; A 48 years old woman went under aort valve replacement (AVR) because of severe aort insufficiency and a 43 years old man went under AVR+mitral valve replacement (MVR) operation. The third patient was a 35 years old woman with rheumatismal carditis and operated for MVR planning. To monitor the hemodynamic changes in detail, a PAC catheter was introduced from right internal jugular vein in all cases. There wasn't any problem during early postop period and on 2nd day catheter was tried to removed but it got stucked at 15th and 20th cm.s and in the 3rd patient at 25th cm.

Results

Radiographic images showed that catheters were resisted to displacement because they were knotted near the thermosistor part in two cases (Figures 1,2 and 3).

Figure 1

Figure 1: X-ray image of PAC knot resisting at 10cm of the first woman case(AVR performed).

Figure 2

Figure 2: X-ray image of PAC knot resisting at 20cm in second case (AVR+MVR performed).

Figure 3

Figure 3: Close view of the knot,resisting at 20cm in second case.

In third case catheter was fixed at right atrial level. This finding was determined with emergent transthoracic echocardiography. In the first two cases, catheters were pulled with appropriate manipulations and knot became smaller. Then,the knotted segment was removed from side-arm introducer dilated venous and skin entering points. Compression prevented the morbid hemorrhage and hematoma complications at catheter placement regions(Figure 4).

Figure 4

Figure 4: Catheter which was removed successfully by a non-invasive method from the second case.

Third case was reoperated because it was thought to be fixed with atrial sutures and open surgery technique showed that the catheter's distal end was fixed between right atrial auricule purse sutures. The first 2 cases discharged at postop 7th and the third at 8th day with cure. There wasn't any long-term complication due to postop oral warfarin therapy and they're still controlled at our clinic.

Discussion

Pulmonary artery catheter(PAC) is one of the most frequent used materials peroperatively and postoperatively by surgeons, anesthesia teams and ICU staff in order to get information and control(₄,₅).In1970's Swan and Ganz developed a cardiac catheter with an inflating-deflating balloon at the end and tested it. Inflation of the balloon permitted blood flow to direct further advancement of the catheter to the targeted level.Inserting the correct catheter became easy and directive collateral imaging method necessity decreased(₂).Pulmonary artery thermodilution catheter allows to determine many measurement parameters as; central venous, right atrial and intraventricular pressures, pulmonary artery diastolic-systolic-mean arterial pressures, pulmonary capillary wedge pressure(PCWP), cardiac output, mixt venous oxygen pressures, central body heat, cardiac volume per minute and cardiac index(₄,₅,₆). If mitral valve is compact, PCWP corresponds well to left atrial pressure and in turn left ventricular end diastolic pressure(Figure 5).

Figure 5

Figure 5: Schematic view of functional parts of PAC.

Boyd et al. reported an incidence of 0.2% for catheter looping(₇). Identified risk factors that increase likelihood of loop formation,knotting of the catheter are blind introduction and small diameter of catheter, incomplete balloon inflation before advancing it, several tries to wedge it, bending of the catheter by heat, and enlarged right heart chambers. More frequent sites of knotting are right atrium and ventricle, subclavian vein, and pulmonary artery and its branches. Diagnostic confirmation is made by chest radiography, fluoroscopy, and echocardiography(₈). Chest radiography should be used to specifically ascertain that the catheter is not in a dangerous location(₉).

To avoid from knotting during PAC procedures,it must be known that insertion point of the catheter is on right internal jugular vein and right atrium is 20cm and pulmonary artery tracing is 40-45cm away from this point.If you can't reach the appropriate pressure tracing despite advancing the catheter 10cm further than standart measures,catheter must be withdrawn and procedure must be repeated (₄). This approach is important to prevent and knotting of the catheter in right atrium and ventricle.If there is resistance to removal,then curling or knotting must be remembered first. This occurs if catheter is advanced so far that it curls over itself(₄,₁₀,₁₁). So,catheter musn't be advanced more than 10cm if tracing continues at the space with catheter tracing. Additionally,knotting risk is increased in patients with pulmonary hypertension as in our three cases(₁₀,₁₁).

Catheter must be removed if knotting is present. There are three methods for removing(₁₁,₁₂,₁₃,₁₄,₁₅):

1) The catheter is removed by manuplative maneuvers with serial radiographic evaluations and by comparing the knot size with the introducer tip,removing the knotted end from venous and skin punction regions,which were enlarged by side-arm introducer without additional surgery.

2) If radiography or fluoroscopy showed that diameter of knot loop is 1-1.5cm or larger and can not be minimalized with manuplative maneuvers, direct pulling is not indicated because vein can be dissected at thoracic and cervical region.Under fluoroscopy, via the jugular vein containing the catheter,Judkins catheter or via femoral vein, pig tail catheter advanced into right atrium and directed to vena cava inferior after passing in the knot loop.Loop is fixed with Judkins or pigtail catheter and knot is solved slowly. This helps to remove the knotted catheter without an additional operation and there isn't any operative morbidity.

3) Open surgery can be necessary for complicated ones or the catheters accidentally fixed with atrial sutures which can't be solved with the former methods.

Other reported complications of PAC include cardiac or cava perforation, damage to heart valves, entrapment in chordae tendineae, perforation and pseudoaneurysm of the pulmonary artery, pulmonary infarctus,tricuspid or pulmonary valve injury, endocarditis, and pulmonary embolism(₉,¹⁶). The most frequent minor complication is arrhytmia and it's rate is 50% (₄,₁₀,₁₁).

In conclusion; a catheter is a safe invasive tool for majority, if necessary safety measures are taken. Especially, the presure measures with PAC has a rich clinical information potential.PAC indications are increasing so will be the complications,therefore developing the information about their treatment can prevent additional morbidity and mortality.

Correspondence to

Doç.Dr. Ufuk YETKIN 1379 Sok. No: 9,Burç Apt. D: 13 35220, Alsancak – IZMIR / TURKEY Tel: +90 505 3124906 Fax: +90 232 2434848 e-mail:ufuk_yetkin@yahoo.fr