- Email: [email protected]
Does intraoperative transesophageal echocardiography predict pulmonary valve dysfunction during the Ross procedure?
Does Intraoperative Transesophageal Echocardiography Predict Pulmonary Valve Dysfunction During the Ross Procedure? Carmen B. Gomez, MD, Pablo G. Stutzbach, MD, Eduardo Guevara, MD, and Roberto R. Favaloro, MD Objective: To determine the value of intraoperative transesophageal echocardiography for the assessment of the pulmonary valve anatomy and the pulmonary autograft performance in patients undergoing the Ross procedure. Design: Open, prospective, observational survey. Setting: Favaloro Foundation, single institution. Participants: Consecutive patients undergoing elective Ross procedure (n ⴝ 87). Interventions: Pulmonary valve function and anatomy were assessed by transesophageal echocardiography and the surgeon. Pulmonary autograft function was assessed after implantation. Regurgitation was considered mild (ⴙ/ 4), moderate (ⴙⴙ/4), moderate-to-severe (ⴙⴙⴙ/4), and severe (ⴙⴙⴙⴙ/4). Patients were restudied during midterm follow-up. Measurements and Main Results: The Ross procedure was done in 74 patients (85%). Overall mortality was 3.4%. Mean follow-up was 24 ⴞ 13 months. The Ross procedure was not done in 13 patients (15%): 6 patients had a bicuspid pulmonary valve, 6 patients had >3 mm fenestrations, and 1 patient had regurgitation. The surgeon diagnosed anomalies in
the pulmonary valve through direct observation. Transesophageal echocardiography was not sensitive enough to diagnose pulmonary valve defects in 12 of 13 patients with anomalies. Pulmonary valve regurgitation was identified by intraoperative transesophageal echocardiography in only 1 patient. Autograft regurgitation was 1.07 ⴞ 0.35 at postoperative evaluation. At 1, 6, and 12 months, it was 1.25 ⴞ 0.7 (p ⴝ 0.18), 1.27 ⴞ 0.9 (p ⴝ 0.185), and 1.29 ⴞ 0.8 (p ⴝ 0.17). The difference in values was not statistically significant. Four patients (5.4%) showed an increase in regurgitation during the first transthoracic autograft control. Conclusion: Intraoperative transesophageal echocardiography allows assessment of autograft performance after implantation. This method is not helpful, however, in detecting pulmonary valve anatomic anomalies. Copyright 2002, Elsevier Science (USA). All rights reserved.
T
Patients were premedicated in the operating room with midazolam or diazepam, 0.05 to 0.1 mg/kg. In most patients, anesthesia was induced with propofol, 0.5 mg/kg; fentanyl, 3 to 4 g/kg; and pancuronium, 0.15 mg/kg. Maintenance anesthesia was achieved with fentanyl infusion, 0.08 g/kg/min, or a continuous infusion of propofol, 0.04 mg/kg/min, and isoflurane, ⬍1%.12 A continuous aprotinin infusion was used according to the Hammermich protocol to prevent bleeding.13 Standard invasive hemodynamic monitoring was done with a catheter in the radial artery and one in the internal jugular vein to measure mean arterial pressure and central venous pressure. Most patients were gradually weaned from CPB with vasodilators, which produced controlled hypotension until the reversal of heparinization and surgical hemostasis were obtained.
HE USE OF THE pulmonary autograft in aortic position was first reported by Ross in 1967.1 Prolonged cardiopulmonary bypass (CPB) and the problems it presents discouraged use of the Ross procedure until the 1990s. In 1998, the International Registry of the Ross Procedure reported the clinical outcomes of 3,123 patients undergoing this procedure.2 The main advantage of the pulmonary autograft over the aortic homograft is that it is an autologous tissue that remains viable after implantation. Aortic homografts may present more serious histologic degeneration, whereas pulmonary autografts are less likely to degenerate. The pulmonary autograft entails low risk of thromboembolism and infection, and it generally does not require temporary or permanent anticoagulant therapy, as a mechanical prosthesis does.3 Some studies already have focused on the analysis of the findings of intraoperative transesophageal echocardiography (IOTEE) monitoring during cardiac valve surgery and concluded that it is a valuable tool in the diagnosis and treatment of heart valve disease.4-8 This method allows evaluating the valvular anatomy and preoperative and postoperative function, constituting the method of choice in heart valve surgery operative decision making, guidance of the reconstructive technique, assessment of adequacy of mitral valve repair, and prediction of late results.8-11 The value of this method in the assessment of the native valve for use in the Ross procedure has not been determined yet. The present study evaluates the usefulness of this method for the assessment of the pulmonary valve anatomy and pulmonary autograft performance in patients undergoing the Ross procedure and compares immediate postoperative findings with midterm results. METHODS From 1995 to 1999, the Ross procedure was indicated in 87 patients (27 women and 60 men). The mean age was 37⫾12 years. Baseline characteristics of the population are shown in Table 1.
KEY WORDS: Ross procedure, intraoperative transesophageal echocardiography (IOTEE), autograft performance, pulmonary anatomy
Echocardiographic Monitoring Preoperatively, all patients were examined by transthoracic Doppler echocardiography assessing the pulmonary valve by a short-axis view and the aortic valve by 4-chamber and long-axis views. Intraoperative monitoring was performed with Sonos 1500, 2500, and 5500 (Hewlett Packard, Andover, MA) echocardiographic machines with a 5.5- to 3.7-MHz Omniplane I probe. IOTEE was performed by echocardiographers or when performed by the anesthesiologist in the operating room was monitored by staff of the Department of Echocardiography by a closed circuit television system. Images were obtained before skin incision and before and after CPB. Standard images were obtained in all patients, including a midesophageal 4-chamber view and left atrium, left ventricle, and mitral and aortic valve long-axis views. A 2-chamber view (0° to 130°) that
From the Department of Cardiovascular Surgery, Section of Anesthesiology and Heart Valve Disease, Favaloro Foundation, Buenos Aires, Argentina. Address reprint requests to Carmen B. Gomez, MD, Favaloro Foundation, Belgrano 1746, 1093 Buenos Aires, Argentina. E-mail: [email protected] Copyright 2002, Elsevier Science (USA). All rights reserved. 1053-0770/02/1604-0009$35.00/0 doi:10.1053/jcan.2002.125147
Journal of Cardiothoracic and Vascular Anesthesia, Vol 16, No 4 (August), 2002: pp 437-440
437
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GOMEZ ET AL
Table 1. Demographic, Clinical, and Perioperative Data Patients (n ⫽ 87)
Mean age (y) Gender Male Female Aortic regurgitation Aortic stenosis Endocarditis NYHA Functional class I-II Functional class III-IV Mean LVEF (%) Aortic homograft Mechanical aortic valve RP (isolated) RP (combined)
37 ⫾ 12 27 (68%) 60 (32%) 43 (49%) 41 (47%) 3 (4%) 73 (84%) 14 (16%) 55 ⫾ 12 (30-70)* 10 3 60 14
Abbreviations: NYHA, New York Heart Association; LVEF, left ventricular ejection fraction; RP, Ross procedure. *Range in parentheses.
allowed visualization of the left ventricular outflow tract, aortic valve, and first few centimeters of the ascending aorta was obtained with the multiplane probe. A pulmonary artery longitudinal view was obtained to view the right ventricular outflow tract, pulmonary valve, and proximal pulmonary artery. The pulmonary valve regurgitation grade was quantified before and after placing the pulmonary valve in the aortic position by color Doppler echocardiography: ⫹/4 was considered mild; ⫹⫹/4, moderate; ⫹⫹⫹/4, moderate-to-severe; and ⫹⫹⫹⫹/4, severe. Regurgitation grade ⬎⫹⫹/4 was considered to be autograft dysfunction. Continuous IOTEE monitoring was performed to determine the left ventricular function.
Fig 1. Pulmonary autograft mean regurgitation. ID: intraoperative pts: patients
(1.1%). The surgeon diagnosed anomalies in the pulmonary valve through direct observation. IOTEE was not sensitive enough to diagnose pulmonary valve defects in 12 of 13 (92%) patients with anomalies. It was possible to identify pulmonary valve regurgitation by IOTEE in only 1 patient (8%). Monitoring of the pulmonary autograft performance during surgery identified severe regurgitation in 2 patients, in whom the pulmonary autograft was replaced during the same surgery. Mean regurgitation of the patients with normal pulmonary autograft function during intraoperative control was 1.07 ⫾ 0.35 (⫹/4), whereas at 1, 6, and 12 months it was 1.25 ⫾ 0.7 (p ⫽ 0.18), 1.27 ⫾ 0.9 (p ⫽ 0.185), and 1.29 ⫾ 0.8 (p ⫽ 0.17) (Fig 1). The difference in the values of the 3 postoperative evaluations compared with the IOTEE was not statistically significant. Four patients (5.4%) showed an increase in regurgitation during the first transthoracic autograft follow-up measurements (Fig 2).
Surgical Technique Aortic root replacement was done with 4-0 blue-braided polyester fiber (Tychron) interrupted suture on the aortic annulus, reimplantation of coronary ostia was done with 6-0 or 5-0 polypropylene (Prolene) suture, and aortopulmonary distal anastomosis was done with 5-0 continuous suture. At the beginning of this series, no effort was made to match the aortic and pulmonary autograft annulus. Later the aortic and pulmonary annuli were matched using Northrup’s14 or Elkins’15 techniques, and the diameters of both structures were carefully verified. The sinotubular junction was stabilized to prevent dilation and autograft regurgitation. The procedure was done using CPB with a membrane oxygenator, moderate hypothermia, and myocardial protection with anterograde and retrograde blood cardioplegia and topical ice slush. Patients were evaluated clinically and echocardiographically at 1, 3, and 6 months after surgery and once a year thereafter. Hospital mortality was defined as any death occurring within 30 days of surgery either before or after discharge. Mean values and SDs were calculated for all variables. The analysis of preoperative and intraoperative variables was done with Student t-test and chi-square tests.
DISCUSSION
For a long time, knowledge about the outcomes of the Ross procedure was limited. In the past, the results of the International Registry of the Ross Procedure and the experience published by pioneers of the technique contributed to clarify some issues and to renew interest in the procedure. In the 1990s, improved myocardial protection techniques allowed an in-hospital mortality similar to that of other surgical techniques to be achieved. Santini et al16 reported morbidity and mortality rates comparable to those of aortic homografts.
RESULTS
The Ross procedure was performed in 74 patients. Overall mortality was 3.4%. Mean follow-up was 24 ⫾ 13 months. The Ross procedure was not done in 13 patients (15%): 6 patients had a bicuspid pulmonary valve (6.8%), 6 patients had ⬎3 mm fenestrations (6.8%), and 1 patient had severe regurgitation
Fig 2. Pulmonary autograft regurgitation in different patients. ID: intraoperative pts: patients
PULMONARY VALVE DYSFUNCTION DURING ROSS PROCEDURE
The Ross procedure is technically complex enough to require an adequately trained surgical and anesthetic team. It is possible to protect the autograft by means of controlled hypotension. A careful control of hemostasis decreases the postoperative bleeding rate. Antifibrinolytics reduce blood loss and transfusions in patients undergoing valvular surgery.12,17 In the authors’ experience, aprotinin was reserved for patients at risk of excessive bleeding, such as patients undergoing the Ross procedure or cardiac reoperation. For the procedure to be successful it is important to select the patient correctly: ⬍35 mm aortic annulus and a normal pulmonary valve are essential characteristics. Autograft acute failure was present in only 2 patients. It was caused by an anatomic defect of the pulmonary valve. IOTEE monitoring could not predict the anomaly, but it allowed the failure to be assessed when the pulmonary valve was transferred into the aortic position, and the autograft could be replaced during the same surgery. According to these results, patients with a bicuspid aortic valve were significantly associated with a higher probability of pulmonary valve anatomic defects.18 Of the patients with an indication for the Ross procedure, approximately 10% were not eligible because they presented with pulmonary valve anatomic defects, which necessitated a careful direct exploration before the dissection to corroborate its anatomic indemnity because it was not possible to accurately assess its anatomy by means of TEE. Late follow-up confirmed the favorable outcomes of the procedure. Chambers et al19 reported 88% and 75% freedom from reoperation because of autograft failure at 10 and 20 years. In this survey, incidence of pulmonary autograft failure (regurgitation) is directly related to the authors’ initial experience, when a small proportion of the 10 patients who were not operated on with Elkins’ or Northrup’s techniques presented with severe insufficiency.20 The history of aortic insufficiency that led to autograft failure was caused by the mismatch of the
439
pulmonary autograft with the aortic annulus owing to the increase in size of the annulus. David et al21 also suggested this mechanism may generate pulmonary autograft insufficiency. The use of the above-mentioned techniques22 to reduce the annulus size allows matching both structures, which would explain freedom from pulmonary autograft failure in the rest of the patients. IOTEE accuracy to measure the pulmonary annulus and the aortic annulus diameters has been well studied, finding a high correlation between the surgeon’s and IOTEE measurements.23,24 The stability of the sinotubular junction at the time of the Ross procedure prevents regurgitation of the pulmonary autograft. The Elkins procedure refers to the matching of the aortic annulus with the pulmonary annulus. This matching also was done after Northrup’s technique, in which the commissures are plicated to reduce the aortic annulus when there is annulus dilation. IOTEE was useful to determine that there was aortic dilation at the sinotubular junction. The surgeon decided whether the ascending aorta was tailored to reduce the diameter, however, and to match the diameter of the pulmonary autograft. IOTEE was helpful in the long-term follow-up because it showed that there was autograft insufficiency in patients with aortic annular dilation. On those grounds, the authors started to perform aortic annuloplasty to match the aortic and pulmonary annuli. Although it is possible to predict late dysfunction with IOTEE monitoring after mitral valve repair, this is not possible for the Ross procedure. Fix et al11 showed that IOTEE monitoring after mitral valve repair identified patients with ⬎⫹⫹⫹/4 regurgitation as a high-risk population that may require reoperation. It is not possible to predict late reoperation in patients undergoing the Ross procedure because pulmonary autograft remodeling may cause late failure and valve prolapse.21,25
REFERENCES 1. Ross DN: Replacement of aortic and mitral valves with pulmonary autograft. Lancet 2:956-958, 1967 2. Oury JH, Mackey K, Duran C: Critical analysis of the Ross procedure: Do its problems justify wider application? Semin Thorac Cardiovasc Surg 11:55-61, 1999 3. Elkins RC: Pulmonary autograft: The optimal substitute for the aortic valve? N Engl J Med 330:59-60, 1994 4. Michel-Cherqui M, Ceddaha A, Liu N, et al: Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: A prospective study of 203 patients. J Cardiothor Vasc Anesth 14:45-50, 2000 5. De Simone R, Lange R, Saggau W, et al: Intraoperative transesophageal echocardiography for the evaluation of mitral, aortic and tricuspid valve repair: A tool to optimize surgical outcome. Eur J Cardiothorac Surg 6:665-673, 1992 6. Bryan AJ, Barzilai B, Kouchoukos NT: Transesophageal echocardiography and adult cardiac operations. Ann Thorac Surg 59:773779, 1995 7. D’Ambra M: Is intraoperative echocardiography a useful monitor in the operating room? Ann Thorac Surg 56:S83-S85, 1993 8. Practice guidelines for perioperative transesophageal echocardiophy. A report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiolgy 84:986-1106, 1996
9. Stewart W, Currie P, Salcedo E, et al: Intraoperative Doppler color-flow mapping for decision-making in valve repair for mitral regurgitation. Circulation 81:556-566, 1990 10. Stewart W, Salcedo E, Cosgrove D: The value of echocardiography in mitral valve repair. Cleve Clin J Med 57:177-183, 1990 11. Fix J, Isada L, Cosgrove D, et al: Do patients with less than “Echo-perfect” results from mitral valve repair by intraoperative echocardiography have a different outcome? Circulation 88:II 39-48, 1993 12. Rich JB: The efficacy and safety of aprotinin use in cardiac surgery. Ann Thorac Surg 66:S6-11, 1998 13. Gomez C, Stutzbach P, Favaloro RR: A systematic technical anesthetic approach to the Ross operation. 6th International Congress of Cardiothoracic and Vascular Anesthesia, Santiago, Chile, 1998 14. Northrup WF, Kshettry VR: Implantation technique of the freestanding homograft or autograft root: Emphasis on matching the host root to the graft. Ann Thorac Surg 66:280-284, 1998 15. Elkins RC, Santangelo KL, Stelzer P, et al: Pulmonary autograft replacement of the aortic valve: An evolution of technique. J Card Surg 7:108-116, 1992 16. Santini F, Dyke C, Edward S, et al: Pulmonary autograft versus homograft replacement of the aortic valve: A prospective randomized trial. J Thorac Cardiovasc Surg 113:894-900, 1997 17. Cahalan M: Anesthesia for cardiac valvular surgery. Anesth Analg 2000 (suppl): 1-5
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18. Favaloro RR, Stutzbach PG, Gomez CB, et al: Feasibility of Ross procedure: Its relationship to bicuspid aortic valve. Rev Argent Cardiol 67:S56, 1999 19. Chambers JC, Somerville J, Stone S, Ross D: Pulmonary autograft procedure for aortic valve disease: Long-term results of the pioneer series. Circulation 96:2206-2214, 1997 20. Favaloro RR, Stutzbach P, Machain AL, et al: Aortic valve diseases: Results at 3 years of follow-up of the Ross procedure. Rev Argent Cardiol 67:317-324, 1999 21. David T, Omran A, Webb G, et al: Geometric mismatch of the aortic and pulmonary roots causes aortic insufficiency after Ross procedure. J Thorac Cardiovasc Surg 112:1231-1239, 1996
GOMEZ ET AL
22. Elkins R: Pulmonary autograft: Expanding indications and increasing utilizations. J Heart Valve Dis 3:356-357, 1994 23. Oh CC, Click RL, Orszulak TA, et al: Role of intraoperative transesophageal echocardiography in determining aortic annulus diameter in homograft insertion. J Am Soc Echocardiogr 11:638-642, 1998 24. Weinert L, Karp R, Vignon P: Feasibility of aortic diameter measurement by multiplane tranesophageal echocardiography for preoperative selection and preparation of homograft aortic valves. J Thorac Cardiovasc Surg 112:954-961, 1996 25. Hokken R, Bogers JJ, Taams M, et al: Does the pulmonary autograft in the aortic position in adults increase in diameter? An echocardiographic study. J Thorac Cardiovasc Surg 113:667-674, 1997
the pulmonary valve through direct observation. Transesophageal echocardiography was not sensitive enough to diagnose pulmonary valve defects in 12 of 13 patients with anomalies. Pulmonary valve regurgitation was identified by intraoperative transesophageal echocardiography in only 1 patient. Autograft regurgitation was 1.07 ⴞ 0.35 at postoperative evaluation. At 1, 6, and 12 months, it was 1.25 ⴞ 0.7 (p ⴝ 0.18), 1.27 ⴞ 0.9 (p ⴝ 0.185), and 1.29 ⴞ 0.8 (p ⴝ 0.17). The difference in values was not statistically significant. Four patients (5.4%) showed an increase in regurgitation during the first transthoracic autograft control. Conclusion: Intraoperative transesophageal echocardiography allows assessment of autograft performance after implantation. This method is not helpful, however, in detecting pulmonary valve anatomic anomalies. Copyright 2002, Elsevier Science (USA). All rights reserved.
T
Patients were premedicated in the operating room with midazolam or diazepam, 0.05 to 0.1 mg/kg. In most patients, anesthesia was induced with propofol, 0.5 mg/kg; fentanyl, 3 to 4 g/kg; and pancuronium, 0.15 mg/kg. Maintenance anesthesia was achieved with fentanyl infusion, 0.08 g/kg/min, or a continuous infusion of propofol, 0.04 mg/kg/min, and isoflurane, ⬍1%.12 A continuous aprotinin infusion was used according to the Hammermich protocol to prevent bleeding.13 Standard invasive hemodynamic monitoring was done with a catheter in the radial artery and one in the internal jugular vein to measure mean arterial pressure and central venous pressure. Most patients were gradually weaned from CPB with vasodilators, which produced controlled hypotension until the reversal of heparinization and surgical hemostasis were obtained.
HE USE OF THE pulmonary autograft in aortic position was first reported by Ross in 1967.1 Prolonged cardiopulmonary bypass (CPB) and the problems it presents discouraged use of the Ross procedure until the 1990s. In 1998, the International Registry of the Ross Procedure reported the clinical outcomes of 3,123 patients undergoing this procedure.2 The main advantage of the pulmonary autograft over the aortic homograft is that it is an autologous tissue that remains viable after implantation. Aortic homografts may present more serious histologic degeneration, whereas pulmonary autografts are less likely to degenerate. The pulmonary autograft entails low risk of thromboembolism and infection, and it generally does not require temporary or permanent anticoagulant therapy, as a mechanical prosthesis does.3 Some studies already have focused on the analysis of the findings of intraoperative transesophageal echocardiography (IOTEE) monitoring during cardiac valve surgery and concluded that it is a valuable tool in the diagnosis and treatment of heart valve disease.4-8 This method allows evaluating the valvular anatomy and preoperative and postoperative function, constituting the method of choice in heart valve surgery operative decision making, guidance of the reconstructive technique, assessment of adequacy of mitral valve repair, and prediction of late results.8-11 The value of this method in the assessment of the native valve for use in the Ross procedure has not been determined yet. The present study evaluates the usefulness of this method for the assessment of the pulmonary valve anatomy and pulmonary autograft performance in patients undergoing the Ross procedure and compares immediate postoperative findings with midterm results. METHODS From 1995 to 1999, the Ross procedure was indicated in 87 patients (27 women and 60 men). The mean age was 37⫾12 years. Baseline characteristics of the population are shown in Table 1.
KEY WORDS: Ross procedure, intraoperative transesophageal echocardiography (IOTEE), autograft performance, pulmonary anatomy
Echocardiographic Monitoring Preoperatively, all patients were examined by transthoracic Doppler echocardiography assessing the pulmonary valve by a short-axis view and the aortic valve by 4-chamber and long-axis views. Intraoperative monitoring was performed with Sonos 1500, 2500, and 5500 (Hewlett Packard, Andover, MA) echocardiographic machines with a 5.5- to 3.7-MHz Omniplane I probe. IOTEE was performed by echocardiographers or when performed by the anesthesiologist in the operating room was monitored by staff of the Department of Echocardiography by a closed circuit television system. Images were obtained before skin incision and before and after CPB. Standard images were obtained in all patients, including a midesophageal 4-chamber view and left atrium, left ventricle, and mitral and aortic valve long-axis views. A 2-chamber view (0° to 130°) that
From the Department of Cardiovascular Surgery, Section of Anesthesiology and Heart Valve Disease, Favaloro Foundation, Buenos Aires, Argentina. Address reprint requests to Carmen B. Gomez, MD, Favaloro Foundation, Belgrano 1746, 1093 Buenos Aires, Argentina. E-mail: [email protected] Copyright 2002, Elsevier Science (USA). All rights reserved. 1053-0770/02/1604-0009$35.00/0 doi:10.1053/jcan.2002.125147
Journal of Cardiothoracic and Vascular Anesthesia, Vol 16, No 4 (August), 2002: pp 437-440
437
438
GOMEZ ET AL
Table 1. Demographic, Clinical, and Perioperative Data Patients (n ⫽ 87)
Mean age (y) Gender Male Female Aortic regurgitation Aortic stenosis Endocarditis NYHA Functional class I-II Functional class III-IV Mean LVEF (%) Aortic homograft Mechanical aortic valve RP (isolated) RP (combined)
37 ⫾ 12 27 (68%) 60 (32%) 43 (49%) 41 (47%) 3 (4%) 73 (84%) 14 (16%) 55 ⫾ 12 (30-70)* 10 3 60 14
Abbreviations: NYHA, New York Heart Association; LVEF, left ventricular ejection fraction; RP, Ross procedure. *Range in parentheses.
allowed visualization of the left ventricular outflow tract, aortic valve, and first few centimeters of the ascending aorta was obtained with the multiplane probe. A pulmonary artery longitudinal view was obtained to view the right ventricular outflow tract, pulmonary valve, and proximal pulmonary artery. The pulmonary valve regurgitation grade was quantified before and after placing the pulmonary valve in the aortic position by color Doppler echocardiography: ⫹/4 was considered mild; ⫹⫹/4, moderate; ⫹⫹⫹/4, moderate-to-severe; and ⫹⫹⫹⫹/4, severe. Regurgitation grade ⬎⫹⫹/4 was considered to be autograft dysfunction. Continuous IOTEE monitoring was performed to determine the left ventricular function.
Fig 1. Pulmonary autograft mean regurgitation. ID: intraoperative pts: patients
(1.1%). The surgeon diagnosed anomalies in the pulmonary valve through direct observation. IOTEE was not sensitive enough to diagnose pulmonary valve defects in 12 of 13 (92%) patients with anomalies. It was possible to identify pulmonary valve regurgitation by IOTEE in only 1 patient (8%). Monitoring of the pulmonary autograft performance during surgery identified severe regurgitation in 2 patients, in whom the pulmonary autograft was replaced during the same surgery. Mean regurgitation of the patients with normal pulmonary autograft function during intraoperative control was 1.07 ⫾ 0.35 (⫹/4), whereas at 1, 6, and 12 months it was 1.25 ⫾ 0.7 (p ⫽ 0.18), 1.27 ⫾ 0.9 (p ⫽ 0.185), and 1.29 ⫾ 0.8 (p ⫽ 0.17) (Fig 1). The difference in the values of the 3 postoperative evaluations compared with the IOTEE was not statistically significant. Four patients (5.4%) showed an increase in regurgitation during the first transthoracic autograft follow-up measurements (Fig 2).
Surgical Technique Aortic root replacement was done with 4-0 blue-braided polyester fiber (Tychron) interrupted suture on the aortic annulus, reimplantation of coronary ostia was done with 6-0 or 5-0 polypropylene (Prolene) suture, and aortopulmonary distal anastomosis was done with 5-0 continuous suture. At the beginning of this series, no effort was made to match the aortic and pulmonary autograft annulus. Later the aortic and pulmonary annuli were matched using Northrup’s14 or Elkins’15 techniques, and the diameters of both structures were carefully verified. The sinotubular junction was stabilized to prevent dilation and autograft regurgitation. The procedure was done using CPB with a membrane oxygenator, moderate hypothermia, and myocardial protection with anterograde and retrograde blood cardioplegia and topical ice slush. Patients were evaluated clinically and echocardiographically at 1, 3, and 6 months after surgery and once a year thereafter. Hospital mortality was defined as any death occurring within 30 days of surgery either before or after discharge. Mean values and SDs were calculated for all variables. The analysis of preoperative and intraoperative variables was done with Student t-test and chi-square tests.
DISCUSSION
For a long time, knowledge about the outcomes of the Ross procedure was limited. In the past, the results of the International Registry of the Ross Procedure and the experience published by pioneers of the technique contributed to clarify some issues and to renew interest in the procedure. In the 1990s, improved myocardial protection techniques allowed an in-hospital mortality similar to that of other surgical techniques to be achieved. Santini et al16 reported morbidity and mortality rates comparable to those of aortic homografts.
RESULTS
The Ross procedure was performed in 74 patients. Overall mortality was 3.4%. Mean follow-up was 24 ⫾ 13 months. The Ross procedure was not done in 13 patients (15%): 6 patients had a bicuspid pulmonary valve (6.8%), 6 patients had ⬎3 mm fenestrations (6.8%), and 1 patient had severe regurgitation
Fig 2. Pulmonary autograft regurgitation in different patients. ID: intraoperative pts: patients
PULMONARY VALVE DYSFUNCTION DURING ROSS PROCEDURE
The Ross procedure is technically complex enough to require an adequately trained surgical and anesthetic team. It is possible to protect the autograft by means of controlled hypotension. A careful control of hemostasis decreases the postoperative bleeding rate. Antifibrinolytics reduce blood loss and transfusions in patients undergoing valvular surgery.12,17 In the authors’ experience, aprotinin was reserved for patients at risk of excessive bleeding, such as patients undergoing the Ross procedure or cardiac reoperation. For the procedure to be successful it is important to select the patient correctly: ⬍35 mm aortic annulus and a normal pulmonary valve are essential characteristics. Autograft acute failure was present in only 2 patients. It was caused by an anatomic defect of the pulmonary valve. IOTEE monitoring could not predict the anomaly, but it allowed the failure to be assessed when the pulmonary valve was transferred into the aortic position, and the autograft could be replaced during the same surgery. According to these results, patients with a bicuspid aortic valve were significantly associated with a higher probability of pulmonary valve anatomic defects.18 Of the patients with an indication for the Ross procedure, approximately 10% were not eligible because they presented with pulmonary valve anatomic defects, which necessitated a careful direct exploration before the dissection to corroborate its anatomic indemnity because it was not possible to accurately assess its anatomy by means of TEE. Late follow-up confirmed the favorable outcomes of the procedure. Chambers et al19 reported 88% and 75% freedom from reoperation because of autograft failure at 10 and 20 years. In this survey, incidence of pulmonary autograft failure (regurgitation) is directly related to the authors’ initial experience, when a small proportion of the 10 patients who were not operated on with Elkins’ or Northrup’s techniques presented with severe insufficiency.20 The history of aortic insufficiency that led to autograft failure was caused by the mismatch of the
439
pulmonary autograft with the aortic annulus owing to the increase in size of the annulus. David et al21 also suggested this mechanism may generate pulmonary autograft insufficiency. The use of the above-mentioned techniques22 to reduce the annulus size allows matching both structures, which would explain freedom from pulmonary autograft failure in the rest of the patients. IOTEE accuracy to measure the pulmonary annulus and the aortic annulus diameters has been well studied, finding a high correlation between the surgeon’s and IOTEE measurements.23,24 The stability of the sinotubular junction at the time of the Ross procedure prevents regurgitation of the pulmonary autograft. The Elkins procedure refers to the matching of the aortic annulus with the pulmonary annulus. This matching also was done after Northrup’s technique, in which the commissures are plicated to reduce the aortic annulus when there is annulus dilation. IOTEE was useful to determine that there was aortic dilation at the sinotubular junction. The surgeon decided whether the ascending aorta was tailored to reduce the diameter, however, and to match the diameter of the pulmonary autograft. IOTEE was helpful in the long-term follow-up because it showed that there was autograft insufficiency in patients with aortic annular dilation. On those grounds, the authors started to perform aortic annuloplasty to match the aortic and pulmonary annuli. Although it is possible to predict late dysfunction with IOTEE monitoring after mitral valve repair, this is not possible for the Ross procedure. Fix et al11 showed that IOTEE monitoring after mitral valve repair identified patients with ⬎⫹⫹⫹/4 regurgitation as a high-risk population that may require reoperation. It is not possible to predict late reoperation in patients undergoing the Ross procedure because pulmonary autograft remodeling may cause late failure and valve prolapse.21,25
REFERENCES 1. Ross DN: Replacement of aortic and mitral valves with pulmonary autograft. Lancet 2:956-958, 1967 2. Oury JH, Mackey K, Duran C: Critical analysis of the Ross procedure: Do its problems justify wider application? Semin Thorac Cardiovasc Surg 11:55-61, 1999 3. Elkins RC: Pulmonary autograft: The optimal substitute for the aortic valve? N Engl J Med 330:59-60, 1994 4. Michel-Cherqui M, Ceddaha A, Liu N, et al: Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: A prospective study of 203 patients. J Cardiothor Vasc Anesth 14:45-50, 2000 5. De Simone R, Lange R, Saggau W, et al: Intraoperative transesophageal echocardiography for the evaluation of mitral, aortic and tricuspid valve repair: A tool to optimize surgical outcome. Eur J Cardiothorac Surg 6:665-673, 1992 6. Bryan AJ, Barzilai B, Kouchoukos NT: Transesophageal echocardiography and adult cardiac operations. Ann Thorac Surg 59:773779, 1995 7. D’Ambra M: Is intraoperative echocardiography a useful monitor in the operating room? Ann Thorac Surg 56:S83-S85, 1993 8. Practice guidelines for perioperative transesophageal echocardiophy. A report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiolgy 84:986-1106, 1996
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