A 57-yr-old man (weight, 61 kg; height, 158 cm) with a history of hypertension and smoking was scheduled for aortic valve replacement to treat severe aortic stenosis. Echocardiography revealed an aortic valve area of 0.6 cm2 and a mean pressure gradient of 66 mm Hg across the stenotic aortic valve. Left ventricular hypertrophy was evident with normal systolic function and impaired diastolic function indicated by an abnormal relaxation pattern.
After anesthetic induction and tracheal intubation, a 5-MHz multiplane transesophageal echocardiography (TEE) probe (Agilent Technologies, Andover, MA) was inserted into the esophagus. A 7.5F pulmonary artery catheter (PAC) (Edward Lifesciences LLC, Irvine, CA) was then inserted through an 8.5F percutaneous sheath introducer (Argon Medical Devices, Athens, TX) positioned in the right internal jugular vein. A normal pulmonary artery wedge pressure tracing was obtained at a depth of 50 cm, and the position of the catheter tip in the right main pulmonary artery was confirmed by TEE. No difficulties or immediate complications were associated with PAC insertion, and TEE of the right atrium, right ventricle, and pulmonary artery revealed no obvious abnormalities. Two vena cava cannulae (DLP69328, 28F cannula for inferior vena cava [IVC]; Medtronic, Minneapolis, MN) were inserted into the right atrium for cardiopulmonary bypass (CPB).
After aortic valve replacement, the patient was uneventfully separated from CPB, and the 2 vena cava cannulae were easily removed. About 1 h after separation from CPB, there was a change in the waveform of the PAC suggestive of catheter wedging. The PAC tip was thought to be located too deeply; the anesthesiologist encountered resistance while attempting to gently withdraw the PAC by pulling with mild force and the catheter did not move. Therefore, TEE was interrogated to determine the cause of the resistance. A midesophageal bicaval view, with the multiplane angle at 85° and a field depth of 12 cm, revealed an area of relatively high brightness resembling an echogenic spot on the PAC, which was accompanied by acoustic shadowing and was fixed in the IVC cannulation site (Fig. 1). Gentle traction on the PAC produced invagination of the IVC cannulation site (Fig. 1) (Video 1; see Supplemental Digital Content 1, http://links.lww.com/AA/A37, transesophageal echocardiography showing entrapment of a pulmonary artery catheter [PAC]. Midesophageal bicaval view shows PAC entrapment. An area of relatively high brightness, resembling an echogenic spot, is visible on the PAC [circle], accompanied by acoustic shadowing [triangles]. Traction on the PAC produced invagination of the right atrial wall [arrow] with the echogenic spot and acoustic shadowing. The right atrial wall resembles “tenting” following the manual traction. RA, right atrium; LA, left atrium; SVC, superior vena cava; IVC, inferior vena cava; PAC, pulmonary artery catheter.) After we indicated that the PAC might be entrapped at the IVC cannulation site, the surgeon palpated the PAC in the right atrium. A slight pull on the catheter stretched and also pulled the purse string suture at the IVC cannulation site, which confirmed PAC entrapment. A new 2–0 Nespolen purse-string suture was placed around the original stitch, which was excised, and the catheter was released from the suture site without complications. The catheter was then withdrawn without difficulty to determine whether it had been perforated with the needle. The catheter appeared normal, demonstrating that the PAC was not perforated, but merely encircled by the suture. The patient was transferred to the intensive care unit and had an uneventful recovery.
Placement of a PAC for hemodynamic monitoring during cardiac surgery is associated with various complications, one of which is entrapment of the catheter.1 PACs have become entrapped at various locations, such as the cannulation site on the IVC,2–4 the right atriotomy suture line,1,4 the pulmonary artery vent site,4–7 and the right ventricular papillary muscle.1 The mechanisms of catheter entrapment involve a suture encircling or perforating the catheter and knotting of the catheter around cardiac structures (such as the tricuspid apparatus) or around the catheter itself.1,7 In this case, with the aid of TEE, we made an intraoperative diagnosis of PAC entrapment because of encircling by the purse-string suture at the IVC cannulation site. Exact localization of the entrapment site with TEE led to safe surgical removal of the entrapment.
TEE and fluoroscopy are imaging techniques that can be used to confirm the location of an entrapped catheter. However, TEE might be superior to fluoroscopy for intraoperative diagnosis, especially with an open sternotomy, because it is readily available to cardiac anesthesiologists. Other advantages of TEE as a diagnostic modality are that the right atrium, right ventricle, right ventricular outflow tract, and pulmonary artery can be simply and clearly visualized. A few reports have described TEE as a useful tool for diagnosing PAC entrapment at the site of atrial purse-string sutures,2 in the right atrial wall at the site of suturing of the incision for retrograde cardioplegia solution infusion,3 and the pulmonary artery vent suture site.5 Because entrapment can occur at different sites, corresponding to specific scanning planes (Table 1), a combination of different scanning planes would be required to define the entrapment site when the exact site is difficult to confirm.
In this case, the PAC was entrapped at the IVC cannulation site, at the anterior part of the right atrium near the IVC. Therefore, a midesophageal bicaval view was appropriate for confirming the entrapment site; this view also revealed the portion of the catheter in the right atrium that was fixed on the IVC cannulation site. This appeared on TEE images as a relatively high brightness portion, similar to an echogenic spot, with acoustic shadowing beyond it (Fig. 1), and was confirmed by palpation by the surgeon. Furthermore, gentle traction on the PAC produced invagination of the IVC cannulation site, with the echogenic spot with acoustic shadowing also moving with manual traction, resembling “tenting” of the atrial wall. (Fig. 1) (Video 1; see Supplemental Digital Content 1, http://links.lww.com/AA/A37, transesophageal echocardiography showing entrapment of a pulmonary artery catheter [PAC].)
It is necessary to distinguish an entrapped catheter from artifacts such as a side lobe artifact from the catheter or confounding anatomical structures such as the crista terminalis or an elongated Eustachian valve. However, the precise image of the catheter as described above, together with movement of the atrial wall with the echogenic spot with manual traction, the movement being unrelated to the cardiac cycle, facilitated an accurate diagnosis.
Our experience in this case suggests that it is important to check PAC mobility by the application of gentle traction on the catheter, before sternal closure. If resistance is encountered, then TEE evaluation should be performed to locate an entrapped PAC before closing the chest. Entrapping suture images, depicted as an echogenic spot with acoustic shadowing on the PAC, and invagination of the tissue wall at the entrapment site with manual traction, resembling “tenting” in the appropriate TEE view, are likely to localize the entrapment site of the PAC.
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2. Troianos CA, Stypula RW Jr. Transesophageal echocardiographic diagnosis of pulmonary artery catheter entrapment and coiling. Anesthesiology 1993;79:602–4
3. Wang HJ, Wang SS, Liau CS. Transesophageal echocardiographic diagnosis of intracardiac entrapment of a Swan-Ganz catheter in open heart operation. J Am Soc Echocardiogr 2004; 17:277–9
4. Jacobsohn E, Fessler DA, Rosemeier F, Tymkew H, Avidan M. Morbidity and mortality associated with accidentally entrapped pulmonary artery catheters during cardiac surgery: a case series. J Cardiothorac Vasc Anesth 2006;20:371–5
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6. Huang GS, Wang HJ, Chen CH, Ho ST, Wong CS. Pulmonary artery rupture after attempted removal of a pulmonary artery catheter. Anesth Analg 2002;95:299–301
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By Nikolaos J. Skubas, MD, Kent H. Rehfeldt, MD, and Martin J. London, MD
- Intraoperative entrapment of a pulmonary artery catheter (PAC) during cardiac surgery may result from inadvertent suturing at cardiotomy sites, knotting of the catheter around intracardiac structures, or looping of the catheter on itself; transesophageal echocardiography (TEE) 2-dimensional imaging can help delineate the exact mechanism.
- Reproducible movement on TEE imaging of a cardiac wall (usually atrial, as occurred in this case) or other structure with gentle traction on the PAC, is highly suggestive of an entrapped catheter and facilitates localization of the entrapment site.
- An entrapped PAC needs to be distinguished from imaging artifact (eg. side lobe) or normal anatomic variants (Eustachian valve or crista terminalis); high echogenicity of the suspected region of entrapment and motion during gentle traction will usually differentiate the PAC from other echo densities.