Troubles After Swan-Ganz Catheter Placement in Cardiac Surgery

Case 1

A 75-year-old woman was admitted for surgical repair of a severe mitral regurgitation. SG catheter was placed intraoperatively just after induction of anesthesia, following the sequential changes of the pressure waveform as a guidance for the correct positioning. The PA catheter tip resulted at a depth of 40 cm from the insertion point in the right internal jugular vein, and this was correctly related to the patient’s height of 172 cm. After the mitral valve repair was successfully performed, when the pulmonary ventilation was resumed at the end of the cardiopulmonary bypass the patient experienced a sudden prolonged and massive bleeding from the endotracheal tube, with a consequent important deterioration of oxygenation. The SG catheter was removed, protamine was immediately administered to reverse heparinization and continuous blood products infusion was started until the bleeding stopped and the oxygenation progressively improved.

The operation was then completed uneventfully, and the patient was transferred to the ICU in stable conditions.

On the third postoperative day, the daily routine chest X-ray showed a circular opacity in the middle of the right lung. A computed tomography showed a pseudoaneurysm in the lower right pulmonary lobe (41 mm × 28 mm × 47 mm) (Figure 1A, 3-dimensional reconstruction). The patient remained asymptomatic for respiratory symptoms and was deemed eligible for transcatheter embolization of the pseudoaneurysm. The procedure was performed 2 weeks after cardiac surgery with a percutaneous approach, under general anesthesia. A single, 4-loop coil was implanted above the artery rupture point, and surgical glue was added. The following angiogram revealed complete closure of the feeding artery, and the control chest X-ray revealed a reduced size of the pseudoaneurysm (Figure 1B). The patient was discharged after 27 days.

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Figure 1.

(A) Three-dimensional computed tomography (CT) scan reconstruction of right pulmonary artery pseudoanerysm. (B) Chest X-ray after pulmonary artery aneurysm coil embolization. (C) Transesophageal echocardiographic (TEE) 4-chamber view shows anterior leaflet flail with anterior papillary muscle rupture. (D) TEE after tricuspid repair.

Case 2

A 69-year-old woman was admitted for surgical treatment of severe mitral regurgitation, and a SG catheter was placed intraoperatively for hemodynamic monitoring as previously described. The surgical repair was successfully accomplished, and the immediate postoperative course was uneventful. Two days after surgery, when trying to remove the SG catheter, the manoeuver failed because the catheter was completely blocked and impossible to pull out. We hypothesized that the catheter could have been enclosed in the right atrial suture. A noninvasive approach was then decided, and the patient was transferred to the catheterization lab, where under fluoroscopic guidance and using special guidewires inserted through the femoral vein the catheter was finally cut in 2 pieces and pulled out from the jugular and the femoral veins.

A transthoracic echocardiography was performed 2 hours after the procedure due to the detection of an important diastolic murmur; it revealed a massive tricuspid regurgitation with prolapse of the anterior leaflet (Figure 1C) due to the rupture of the anterior papillary muscle. The patient was urgently submitted to a successful surgical tricuspid repair, with anterior papillary muscle reconstruction and annuloplasty (Figure 1D). Postoperative recovery was uneventful and the patient was discharged 15 days later.

Discussion

The use of SG catheters is common practice for hemodynamic monitoring of critically ill patients and patients undergoing cardiac surgery. Complications deriving from their use range from 0.001% to 0.47%. ⁴

We report 2 cases of serious complications following PA catheter insertion during cardiac operations. The first patient developed a right PA pseudoaneurysm, the second patient experienced a massive tricuspid regurgitation after removal of a presumably knotted SG catheter.

In case 1, the patient developed a PA injury likely because the PA catheter advanced too distally when the heart was decompressed during cardiopulmonary bypass: unfortunately we didn’t get a clear TEE view to confirm that. Anticoagulation during cardiopulmonary bypass could have played a role in the occurrence of PA pseudoaneurysm.

We obtained a PA waveform at 40 cm from the inserting point, which is the usual location. In our opinion the depth of insertion of the PA catheter in relation to the patient’s height is important and it would be useful being mindful of this relationship when inserting a PA catheter. We suggest, as reported in the literature, that failure to obtain a PA occlusion (“wedge”) pressure waveform after a PA pressure waveform was obtained, should alert the clinician on the possibility of coiling in the main PA. ⁵

In case 2, the insertion of a pulmonary artery catheter was probably complicated by the formation of a knot around the chordae tendineae of the tricuspid valve; this has already been described in only 2 cases in the literature,^6,7 and it is difficult for anesthesiologists to prevent, and then detect, this kind of devastating complication. Otherwise, we can speculate the tricuspid valve was injured because the catheter was caught on the valve, or due to instrumentation during the removal procedure.

The wrong positioning and the possible kinking of the SG catheter, as well as its forced withdrawal during removal attempts, can result in accidental shear-off of the distal part, with its consequent central embolization into the caval veins, heart chambers or pulmonary vasculature. ⁸

Other procedure-related complications include inadvertent arterial puncture (1.9%), pneumothorax (0.5%), arrhythmias (12.5% to >70%), catheter-related bacteremia (1.3%-2.3%), sepsis, and PA thrombosis. ⁹

Risk factors implicated in PA injury with SG catheter use include age >60 years, female gender, pulmonary hypertension, systemic anticoagulation, long-term steroid use, and surgically induced hypothermia. ¹⁰ Our patients had 4 of these risk factors for sustaining PA injury as a consequence of SG placement. They were older than 60 years, females, and received anticoagulation during the cardiac operation under hypothermia. Studies show that in patients older than 60 years the PA is more likely to rupture at a given pressure compared with younger populations. Cardiac surgery patients are subjected to hypothermia during cardiopulmonary bypass, which may stiffen the catheter, and manipulation of the empty heart may dislodge the catheter thereby increasing the risk of PA injury.

Although this complication has been already reported in the literature, we think it is important for the anesthesiologist to be mindful of it. ⁴ In our opinion, it is important to check by transesophageal echocardiography (TEE) that the PA catheter tip is in the proximal right PA branch or in the main PA when cardiopulmonary bypass is instituted, to prevent this potentially fatal complication. To detect the position of SG catheter, the upper-esophageal ascending aorta short-axis TEE view could be used. PA rupture is in fact a serious and dynamic complication, which can result in high mortality. ⁴

The right lung is the most frequently affected. ⁵ The symptoms may be mild such as slight cough, or severe such as massive hemorrhage. We removed the catheter immediately at the beginning of haemoptysis, but other authors have left the catheter in place,^4,11 and the catheter itself was used to help hemostasis and then removed some days later.

There are currently 2 approaches to treat mechanical complications of SG catheter insertion: surgical (lobectomy or sleeve lung resection) ¹² or endovascular management.^13,14

In case of in-vascular lesions smaller than 2.2 cm without clinical signs, some authors propose just imaging follow-up.^15,16 In case of severe bleeding from the ruptured PA, extracorporeal membrane oxygenation (ECMO) may be indicated as a supportive tool to avoid severe hypoxemia and to stabilize the patient. ¹⁷

In our institution, we remove the PA catheter in the postoperative intensive care unit when the hemodynamic conditions of the patients are stable. Unfortunately, the catheter knotting or entrapment could only be detected when you try to remove it, and in our experience trying to prevent this complication checking the mobility or sliding of the catheter intraoperatively once the right atrial suture has been performed, is not useful.

Despite its extremely low incidence, iatrogenic pulmonary artery rupture or valve damage are serious, life-threatening complications of SG catheterization. It is evident that reoperation strongly increases perioperative risk. SG catheter placement is daily practice in our institution in patients with depressed left ventricular function, or undergoing mitral valve repair or REDO procedure. We suggest to limit the placement in those patients with high risk to develop impairment of cardiac function in the postoperative period, or when the continuous knowledge of intracardiac pressures can bear really meaningful information. The cases presented here provide reasons that support our opinion that PA catheters should only be inserted when the benefit outweighs the risk.