Anesthesia & Analgesia:
Cardiovascular Anesthesiology: Echo Rounds
From the Departments of *Anesthesiology and Pain Medicine, and †Surgery, Division of Cardiothoracic Anesthesiology, University of Washington Medical School, Seattle, Washington.
Accepted for publicationMay 15, 2012.
Published ahead of print December 7, 2012
The authors declare no conflicts of interest.
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Address correspondence to Srdjan Jelacic, MD, Department of Anesthesiology and Pain Medicine, Division of Cardiothoracic Anesthesiology, University of Washington School of Medicine, 1959 NE Pacific St., Seattle, WA 98195-6540. Address e-mail to email@example.com.
Written consent to report this case was received from the patient. A 44-year-old, otherwise healthy woman, with history of progressive shortness of breath was diagnosed with acute pulmonary embolus at an outside hospital and systemically anticoagulated. Two months later, she was transferred to our institution for consideration of pulmonary embolectomy and endarterectomy due to worsening shortness of breath despite therapeutic anticoagulation. Preoperative transthoracic echocardiogram (TTE) at our institution was significant for a large echodensity in the main pulmonary artery extending into left and right pulmonary arteries causing severe pulmonary artery obstruction, and severe right ventricular (RV) enlargement and dysfunction. The pulmonary valve (PV) was interpreted as normal. She was subsequently transported to the operating room for pulmonary embolectomy and endarterectomy.
Intraoperative transesophageal echocardiogram (TEE) confirmed the presence of severe pulmonary artery obstruction with a dense, early peaking jet, a measured peak velocity of 2.6 m/s, and peak pressure gradient of 27 mm Hg. The RV systolic pressure was estimated at 42 mm Hg based on the tricuspid regurgitation jet and measured central venous pressure of 10 mm Hg (Fig. 1). The degree of obstruction was likely underestimated secondary to severely reduced RV systolic function as seen in the transgastric short-axis window; the presence of a “D-shaped” septum was further evidence of RV pressure overload (Video 1, see Supplemental Digital Content, http://links.lww.com/AA/A481). The 2 PV leaflets seen in the RV inflow-outflow view appeared nearly completely destroyed (Video 2, see Supplemental Digital Content 2, http://links.lww.com/AA/A482). Pulmonary regurgitation was not observed on color Doppler images because the pulmonary artery mass completely occluded blood flow during diastole (Video 3, see Supplemental Digital Content 3, http://links.lww.com/AA/A483). We elected not to place a pulmonary artery catheter (PAC) because of the presence of a main pulmonary artery mass that would make the advancement of the catheter impossible and the need to withdraw the PAC to facilitate surgical exposure. After the induction of anesthesia, the patient was hemodynamically unstable requiring emergent initiation of cardiopulmonary bypass. She then underwent pulmonary arteriotomy, tumor debulking and endarterectomy, and PV replacement with a bioprosthetic valve because of extensive involvement of the PV by the tumor. Her postoperative course was uneventful and further work-up did not reveal any metastatic disease. The final pathology revealed high-grade leiomyosarcoma.
Primary pulmonary artery sarcomas are rare with fewer than 250 cases described in the literature since the first published report by Mandelstamm in 1923.1 The most common initial presenting symptoms are cough, dyspnea, and chest pain and common clinical findings include RV dysfunction, pulmonary hypertension, and pulmonary insufficiency.2 It takes on average 3 to 12 months to establish a diagnosis of pulmonary artery sarcoma because they are often misdiagnosed as pulmonary embolus leading to inappropriate therapy or surgical planning. The initial differential diagnosis also includes primary pulmonary hypertension, congenital pulmonary stenosis, fibrosing mediastinitis, or lung tumor. TEE is used to determine the degree of RV dysfunction and the extent of PV involvement. The PV is involved in approximately 30% of the cases,1 which, if diagnosed preoperatively, is a finding that can alter surgical management. Intraoperative TEE in this case revealed unexpected involvement and destruction of the PV that was not appreciated on the preoperative diagnostic evaluation including TTE. The prognosis is poor despite surgical intervention.
The PV is more difficult to image than any other valve by conventional 2-dimensional echocardiography. PV leaflets are thinner than aortic valve leaflets because of the lower pressures on the right side of the heart as compared with the left, which makes them more difficult to visualize. The TTE evaluation of PV morphology is difficult because of poor acoustic windows and the ability to visualize only 1 or 2 cusps simultaneously. The TEE evaluation is even more challenging because the PV is in the anterior position and, therefore, in the far field of the ultrasound beam.
TEE examination of the RV outflow tract and PV was previously described and includes multiple views along with color flow and spectral Doppler measurements.3–5 In addition to the views previously described, the midesophageal ascending aortic short-axis view can be used to evaluate the main pulmonary artery and its branches (Table 1). This view can be developed from the midesophageal RV inflow-outflow view by slightly withdrawing and rotating the multiplane transducer anywhere from 0° to 30°. The right pulmonary artery is usually easier to image and visible on the left side of the monitor. The proximal left pulmonary artery is often difficult to image because of the interposition of the left mainstem bronchus between the esophagus and the left pulmonary artery and may require advancing the probe from the midesophageal ascending aortic short-axis view and turning it slightly to the left (Fig. 2). In some cases, a saline-filled balloon can be inserted into the left main bronchus to improve left pulmonary artery imaging as previously described.6 The short-axis images of the PV are not easily obtainable from the views described above, but can sometimes be developed from midesophageal RV inflow-outflow and aortic valve long-axis views. Although all of these views can be used for interrogation of the PV by color flow Doppler, the spectral Doppler alignment is best achieved from the upper-esophageal aortic arch and transgastric RV outflow views. Because the PAC was not floated, we used TEE spectral Doppler measurements to estimate RV and pulmonary artery systolic pressures (PASP). The transtricuspid pressure gradient using continuous wave Doppler in the absence of pulmonary stenosis or RV outflow tract obstruction is the method of choice for echocardiographic quantification of PASP because this method assumes constant stroke volume across the tricuspid valve and PV. However, in the presence of pulmonary stenosis, estimated PASP is the difference between estimated RV systolic pressure (RVSP) and the peak transpulmonary pressure gradient (PASP = RVSP – 4(PSmax)2 = [4(TRmax)2 + RAP] – 4(PSmax)2; where TRmax refers to peak tricuspid regurgitation velocity, PSmax refers to peak pulmonary stenosis velocity, and RAP refers to right atrial pressure). A comprehensive intraoperative TEE evaluation of PV despite its imaging challenges may reveal important clinical information that can alter surgical management and may not be appreciated on the preoperative diagnostic evaluation.
Name: Srdjan Jelacic, MD.
Contribution: This author helped write the manuscript.
Attestation: Srdjan Jelacic approved the final manuscript.
Name: Robert A. Meguid, MD, MPH.
Contribution: This author helped write the manuscript.
Attestation: Robert A. Meguid approved the final manuscript.
Name: Donald C. Oxorn, MD.
Contribution: This author helped write the manuscript.
Attestation: Donald C. Oxorn approved the final manuscript.
This manuscript was handled by: Martin J. London, MD.
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2. Parish JM, Rosenow EC III, Swensen SJ, Crotty TB. Pulmonary artery sarcoma: clinical features. Chest. 1996;110:1480–8
3. Stechert MM, London MJ. Native aortic root endocarditis with invasion of the right outflow tract. Anesth Analg. 2010;110:36–8
4. Rosenberger P, Cohn LH, Fox JA, Locke A, Shernan SK. Sinus of Valsalva aneurysm obstructing the right ventricular outflow tract. Anesth Analg. 2006;102:1660–1
5. Kurup V, Perrino A Jr, Barash P, Hashim SW. Infundibular pulmonary stenosis. Anesth Analg. 2007;104:507–8
6. Li YL, Wong DT, Wei W, Liu J. A new method for detecting the proximal aortic arch and innominate artery by transesophageal echocardiography. Anesthesiology. 2006;105:226–7
Clinician’s Key Teaching Points
By Nikolaos J. Skubas, MD, Roman M. Sniecinski, MD, and Martin J. London, MD
* Pulmonary artery (PA) tumors result in clinical and echocardiographic findings of pulmonary hypertension and right ventricular (RV) dysfunction and may involve the pumonary valve (PV). The differential diagnosis should include embolus, congenital PA stenosis, lung tumor, post-radiation mediastinitis or primary pulmonary hypertension.
* A dilated RV cavity with decreased free wall motion and flattening of the interventricular septum (transgastric (TG) views) indicates RV pressure overload. The RV systolic pressure (RVSP) can be calculated from the velocity of the tricuspid regurgitation jet (midesophageal (ME) RV inflow-outlfow). The PV leaflets and function should be examined with 2-dimensional and color flow Doppler in the same or the deep TG RV outflow view.
* In this case of a patient scheduled for PA embolectomy, a large tumor was obstructing the main PA (ME ascending aorta short-axis [SAX]) and was associated with immobile and destroyed PV leaflets (ME RV inflow-outflow). The distal systolic PA pressure was normal, calculated as the difference between RVSP and the gradient at the site of main PA obstruction (upper esophageal aortic arch short axis). The tumor was excised and the PV replaced with a bioprosthesis.
* Examination of the PV is challenging, due to its location in the far field transesophageal echocardiogram (TEE) and thin structure of its leaflets. The imaging of the left PA should be facilitated by advancing the TEE probe from the ME ascending aortic SAX view and leftward rotation. This will facilitate planning of the surgical procedure.