| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 2002;73:1130-1137
© 2002 The Society of Thoracic Surgeons
lu, MDalu, MDa, MDa
lker Mataraciapek, MDa
ik, MDa
a Department of Cardiovascular Surgery, Kouyolu Heart and Research Hospital, Istanbul, Turkey
Accepted for publication December 10, 2001.
* Address reprint requests to Dr Kirali, Kouyolu Heart and Research Hospital, 81020, Kadiköy, Istanbul, Türkiye Turkey
e-mail: imkkirali{at}yahoo.com
 |
Abstract |
|---|
 Top Abstract IntroductionMaterial and methodsResultsCommentReferences |
|---|
Methods. Between January 1996 and June 2001, 96 patients underwent aortic root replacement using a flanged composite graft. Eighty patients (83.3%) were male, and 16 patients (16.7%) were female with a mean age of 48.7 ± 14.4 years. Indications for operation were a true or false aneurysm (65.6%), severe calcified aortic valve stenosis (4.2%) or severe aortic insufficiency (2.1%) with dilated ascending aorta, acute dissection (2.1%), or combination of indications (26%). Thirty-one patients (32.3%) received a concomitant cardiac procedure. Mean aortic cross-clamp time was 89.5 ± 28.6 minutes, and mean cardiopulmonary bypass time was 146.2 ± 45.6 minutes. Total follow-up was 253.9 patient-years.
Results. Operative mortality was 8.3% (8 patients). The causes of hospital mortality were severe bleeding (3 patients), low cardiac output syndrome (2), acute respiratory distress syndrome (2) and cerebrovascular event (1). No patient died of flange-related complications. Univariate predictors of early mortality were low cardiac output syndrome (p < 0.001), neurologic complication (p = 0.03), and renal complication (p = 0.03). Multivariate analysis demonstrated only low cardiac output syndrome to be significant (p = 0.001) predictor for early mortality. There were five (5.7%) late deaths. Actuarial survival was 82.65% ± 4.8% at 5 years (1.95% patient-year). Cox proportional hazards regression analysis demonstrated only low cardiac output syndrome to be significant (p = 0.032) predictor for late mortality. Actuarial freedom from prosthetic- and technique-related mortality was 100% at 5 years.
Conclusions. The flanged composite graft offers excellent long-term results, with very low prevalence of prosthetic-related complications. The new created sinuses and the flange are especially helpful to continue physiologic function of the aortic root.
|
Introduction |
|---|
|
TopAbstractIntroductionMaterial and methodsResultsCommentReferences |
|---|
Modified Bentall methods have many beneficial effects such as reduced tension on button coronary anastomoses, prevention of excessive bleeding and development of false aneurysms, avoidance of kinking of coronary arteries, decreased cross-clamp and operation time, and performance of complete aortic root replacement with lower mortality and morbidity rates [9–13]. However, some problems remain: the technique of coronary ostia implantation; the choice of material for conduit formation; the continuance of the physiologic functions of the aortic annulus; the anastomotic technique of graft to the aortic annulus; the repair of iatrogenic subannular defects. The flanged technique deals with last three problems [14].
The purpose of the present study was to assess the early- and long-term outcome of aortic root replacement using the flanged composite graft and to determine risk factors for early and late mortality and morbidity.
|
Material and methods |
|---|
|
TopAbstractIntroductionMaterial and methodsResultsCommentReferences |
|---|
uyolu Heart and Research Hospital. Data were collected with regard to patient age, sex, indication for procedure, prior history of cardiac operation, extent of aortic replacement, need for concomitant procedures (ie, coronary artery bypass grafting, mitral valve replacement, repair of congenital defects), cardiopulmonary bypass time, aortic cross-clamp time, operative time, use and duration of hypothermic circulatory arrest with/without retrograde cerebral perfusion, hospital and late morbidity and mortality. All data have been prospectively entered into an aortic surgery database maintained at our hospital; it is the primary source of data for this report. There were 80 (83.3%) male and 16 (16.7%) female patients. The age of patients ranged from 19 to 77 years (mean, 48.7 ± 14.4 years). Clinical characteristics of patients and the etiology of their aortic lesions are presented in Table 1. Hypertension was the most common preoperative medical disorder, with an incidence of 40.6%. Ascending aortic aneurysms with or without other aortic root pathologies were the most frequent indication for operation, with an incidence of 91.7%. The mean diameter of the ascending aorta was 6.5 ± 1.3 cm (range, 4.4 to 10 cm). The aortic root replacement was performed as an emergency procedure in 8 patients (8.3%) with acute aortic dissection and electively in 88 patients (91.7%). The median ascending aortic diameter of the first 8 patients (5 patients with severe aortic valve and wall calcification, 2 patients with severe aortic insufficiency with thinned aortic wall, and 1 patient with acute type A dissection) was 4.7 cm (range, 4.4 to 4.9 cm). The ascending aorta was dilated (> 5 cm) in the other 88 patients and the median ascending aortic diameter at the time of operation was 6.5 cm (range, 5 to 10 cm with a mean diameter of 6.7 ± 1.2 cm).
|
To replace the aortic root, we built a flanged composite graft intraoperatively using a woven Dacron Hemashield tube graft (Meadox Medicals, Inc, Oakland, NJ) and St. Jude aortic prosthetic valve (St. Jude Medical, Inc, St. Paul, MN) to avoid hemorrhaging through the graft and to benefit from the superior hemodynamics of the prosthetic valve. After we sized the aortic annulus for the prosthetic valve, we chose the tubular graft one or two size wider than the prosthetic valve. A segment of the proximal end of the vascular graft was everted outward to form the flange of the graft. The length of the graft was left 5 or 6 mm to anastomose the graft to the annulus. (The length of the flange, ie, 1 to 3 cm long, is adjusted accordingly depending on the procedure, ie, aortic root enlargement or subannular area repair.) Then, a mechanic valve was inserted into the graft, which was fixed at the four corners to the graft with 4-0 polypropylene sutures. A continuous 4-0 polypropylene suture was used to anastomose the bottom border of the stent of the prosthetic valve to the graft. We prefer pledgeted mattress sutures placed from the aorta to the ventricular aspect to strengthen dissected tissues in type A aortic dissection involving the aortic annulus. The flange of the conduit was then returned to its original position, and implanted into the aortic annulus with a continuous 3-0 polypropylene suture. Therefore, we have, lengthwise, a pseudosinus between the stent of the valve and the tubular graft, and above the prosthetic valve. The left coronary button was implanted with a continuous 5-0 polypropylene suture, and then the right coronary button was anastomosed. The pseudosinuses allowed anastomosis of the coronary ostia to the graft without any tension, and this elasticity prevented bleeding and kinking of the button anastomoses. The distal anastomosis of the graft to the transected aorta was performed with the closed (70 patients) or open (26 patients) technique using hypothermic circulatory arrest with or without retrograde cerebral perfusion. Retrograde cerebral perfusion was used in 19 patients for a mean duration of 17.2 ± 11.1 minutes. We decreased the patient’s temperature to 18°C before removing the cross-clamp and beginning hypothermic circulatory arrest. The aorta was trimmed up to the base of the innominate artery, or if the arch was enlarged or dissected, the entire underside of the arch up to the ligamentum arteriosum was excised, leaving a bevel containing the ostia of the arch vessels and the descending thoracic aorta. The last few sutures on the distal ascending aorta were left loose, and flow through the femoral artery was begun at a rate of 500 to 1,000 mL/min to remove air. After de-airing the aorta, the suture line was pulled up and tied. In cases of acute dissection, the perfusion through the femoral artery was discontinued, and a second arterial cannula was placed within the graft to provide antegrade perfusion during rewarming.
Anticoagulation
In the postoperative period, 150 mg/d acetylsalicylic acid and 2.5 mg/d warfarin sodium was started after extubation and continued lifelong. For patients receiving only prosthetic aortic valve with sinus rhythm, and without pre- and postoperatively thromboembolic complication we chose a dose of anticoagulation with an international normalized ratio between 2.5 to 3. We continued anticoagulation in the remainding patients with an international normalized ratio between 3 to 3.5.
Follow-up
Follow-up data were provided from the patients and hospital records as of May 2001. Follow-up was 100% complete in 96 patients. No patient was lost to follow-up. Total follow-up was 253.9 patient-years, with a mean of 2.6 ± 1.6 years (range, 0 to 5.4 years). All patients underwent echocardiographic, computerized tomographic, or angiographic evaluation in every 6 months.
Statistical methods
The definition of complications and methods of analysis were consistent with the guidelines issued by Edmunds and colleagues [15]. Results are presented as mean ± standard deviation. Twenty-three variables were analyzed: age, gender, preoperative functional class, indication for procedure (aneurysm, dissection, severe aortic calcification), associated diseases (coronary artery disease, chronic obstructive pulmonary disease, hypertension, diabetes), emergency surgery, prior history of cardiac operation, need for concomitant procedures, cardiopulmonary bypass time, aortic cross-clamp time, use of hypothermic circulatory arrest with/without retrograde cerebral perfusion, postoperative complications (recross-clamp, low cardiac output syndrome [LCOS], neurologic, renal, pulmonary, rhythm, infection). Univariate and multivariate analyses were used to assess risk factors as independent predictors of early mortality. Cox proportional hazard regression analysis was used to assess risk factors as independent predictors of patient survival. Differences between categorical variables were tested using a 
2 test; differences between continuous variables were tested using the Student’s t test. Survival curves were constructed using Kaplan-Meier method. Results are presented as mean ± standard error. The log rank test for independent groups was used to test the significance of differences. A p value less than or equal to 0.05 was considered statistically significant for all comparisons. A commercial statistical software package (SPSS for Windows, version 10.0, SPSS Inc, Chicago, IL) was used for data analysis.
|
Results |
|---|
|
TopAbstractIntroductionMaterial and methodsResultsCommentReferences |
|---|
|
|
In the univariate analysis three factors (LCOS, p < 0.001; neurologic complication, p = 0.03; renal complication, p = 0.03) were statistically significant risk factors for early mortality. However, forward stepwise logistic regression analysis indicated only LCOS (p = 0.001) as an independent risk factor for early mortality in the presence of the other factors. The odds ratio for LCOS was 100.5 (95% confidence interval 7 to 1,443).
When we compared survivors with early deaths we found that LCOS and renal complications were significantly higher in latter group (Table 4). Older age, concomitant procedure, and recross-clamp ratios were higher in the same group.
|
Repeat cross-clamp
In 8 patients (8.3%), intraoperative massive bleeding required repeat cross-clamping of the aorta and cardioplegic arrest. In 5 patients, this was attributed to massive bleeding without obvious cause. After cross-clamping we did not find any leak around the aortic annulus and coronary orifices. When we removed the cross-clamp we observed that bleeding continued. The excessive bleeding from the tubular graft itself, which was resterilized more than twice, stopped in 2 patients after protamine sulfate administration. We waited for 30 to 60 minutes, and after bleeding stopped both patientswere discharged from the operating room without any complications. The remaining 3 patients could not wean from cardiopulmonary bypass because of LCOS, which aggravated hemorrhagic problems, and they died.
Three patients required additional sutures to control bleeding after recross-clamping. Massive bleeding occurred at the aortic annulus near the commissure between non- and left coronary sinuses in 1 patient with fragile tissue, and at the lower part of the left coronary ostial anastomosis in 2 patients.
Hospital morbidity
Postoperative complications developed in 40 patients (41.7%). There were a total of 54 early morbid events in these patients (Table 5).
Two patients returned to surgical theater because of bleeding from distal anastomosis 4 days after operation. The bleeding was controlled by a single suture. Both patients had less than 500 mL of blood loss in the first 24 hours, but the drainage exceeded 750 mL in the second and third postoperative days. Temporary neurologic complications involving left or right side weaknesses were observed in 2 patients before extubation on the first postoperative day. In both patients the deficit fully recovered on the third postoperative day, and neither patient has had any further episode. Respiratory failure, defined as a need for mechanical ventilation for more than 24 hours, occurred in 3 patients. One patient developed a wound infection with methicillin-resistant Staphylococcus aureus, and healed after antibiotic therapy without the development of sternal dehiscence. The wound was resutured 2 weeks after the first operation. There were seven atrioventricular blocks, but only 1 patient required a permanent pacemaker.
|
Actuarial survival for the overall 96 patients (including hospital deaths) is shown in Figure 1. Concomitant cardiac procedures did not worsen life expectancy. Five-year freedom from death was 89.4% ± 4.1% in patients without any concomitant procedure versus 71.8% ± 9.8% in patients with a concomitant procedure (Fig 2). Univariate predictors of late mortality were LCOS (p = 0.005) and recross-clamping (p = 0.017); however, only LCOS was found by Cox proportional hazard regression analysis to be associated with increased late mortality in the presence of the other factors (p = 0.032). The odds ratio for LCOS was 13.8 (95% confidence interval 1.25 to 152.77).
|
|
Anticoagulant-related complications
Two patients had complications related to anticoagulant therapy. One of them died from cerebral hemorrhage, the other one from severe gastrointestinal bleeding. We did not detect any other nonfatal anticoagulant-related complications. Freedom from anticoagulant-related complications was 98.6% ± 1.4% at 2 years and 96.3% ± 2.6% at 5 years (Fig 3).
|
|
Comment |
|---|
|
TopAbstractIntroductionMaterial and methodsResultsCommentReferences |
|---|
The technique for reimplantation of the coronary arteries was not a predictor of early mortality. We prefer a bigger diameter for vascular grafts than those for prosthetic valves. After the anastomosis of the bottom border of the prosthetic valve to the graft, a new sinus is created around the stent and above the prosthetic valve. The level of the stent of the prosthetic valve in the tubular graft is higher than in the classic button technique, but it is never higher than 4 to 5 mm from the aortic annulus (Fig 4). This upper location of the prosthetic valve does not hinder coronary anastomosis. The coronary buttons do not require greater mobilization, and they are not located more distally. The pseudosinuses allow the coronary ostia to be reimplanted without any tension or kinking (Fig 5 and 6). During the follow-up period, we have not observed any late complication caused by reimplantation of the coronary arteries. The newly developed aortic root prosthesis can be an alternative to built new sinuses [7]. This type of prostheses allows for better reimplantation of the coronary arteries, and prevents any tension at the anastomotic area. Dossche and associates [12] reported that detachment and mobilization of the coronary arteries was never a problem and could easily be performed within a few minutes. We believe that the button technique is not technically demanding. Our modified technique for aortic root replacement is also not time consuming and has better early and late results than the button technique [16].
|
|
|
The recross-clamping ratio seems higher than in other studies, but we did not detect any leak around the anastomoses. We used resterilized tubular graft in 2 patients and we did not find any leak after reclamping. Massive bleeding occurred from the pores of the grafts, which stopped after protamine sulfate administration and compressing the tubular graft with gauze. In 3 patients bleeding occurred at the left coronary annulus or the left coronary anastomosis. We begin suturing from the middle of the left aortic annulus and finish on the right coronary annulus. At the beginning we preferred Gore-Tex suture (W. L. Gore and Associates, Inc., Flagstaff, Arizona, USA), which was not slippery like polypropylene suture, but we encountered leaks with this suture material. We used polypropylene suture after the twentieth patient and did not observe any bleeding from the anastomotic areas in the last 76 patients. The 3 patients, who died intraoperatively, did not have any detectable bleeding causes. They developed LCOS after removing the cross-clamp and weaning from cardiopulmonary bypass was not possible.
Late complications were infrequent despite the complex nature of the operation. One patient had endocarditis and healed with medical therapy. The most important late complication was anticoagulant-related hemorrhage, which was the cause of late death in 2 patients. The reasons were patient related: the uncontrolled usage of anticoagulation and postponement of routine controls. For this reason we have standardized usage of anticoagulation with 2.5 mg/d in patients who received only a prosthetic aortic valve, and no concomitant procedures or atrial fibrillation. If the patient is cooperative, we arrange anticoagulant therapy according to the patients’ international normalized ratio (maintaining it between 2.5 to 3). In patients with double valve replacement or atrial fibrillation we arrange to keep the international normalized ratio between 3 to 3.5.
There were no late complications caused by the flanged technique. No patient in this study had a pseudoaneurysm in the proximal aortic area or any coronary ostial problems. Hilgenberg and associates [17] reported no reoperation for coronary ostial pseudoaneurysm. However, the incidence of pseudoaneurysm with the button technique was reported between 3.1% and 9% in other series [4, 12, 13]. Depending on the friability of the tissues, they used either a continuous suture or interrupted mattress sutures with a small felt pledget to reattach the coronary artery buttons. Miller and Mitchell [18] describe the use of Teflon felt or autologous pericardium placed around the coronary ostium. We prefer the continuous suture technique for proximal aortic and coronary anastomoses to avoid this late complication. We do not use any felt or autologous pericardium like Dossche and associates [12]. But 2 patients required additional pledget mattress sutures to control bleeding from the left coronary ostial anastomoses.
In summary, composite valve graft replacement of the aortic root can be performed with low mortality and morbidity. Although many different types of the button technique are used for aortic root replacements, only stentless bioprosthesis, allograft, or homograft can continue the geometric and physiologic shape of the aortic annulus. The flanged technique adds three advantages: it enables aortic root enlargement and the use of a bigger prosthetic valve; repair of iatrogenic subvalvular defects occurring during aortic root grafting; and the maintenance of the elasticity and flexibility of the aortic annulus.
|
References |
|---|
|
TopAbstractIntroductionMaterial and methodsResultsCommentReferences |
|---|
lar B., Bozbua N., Gürbüz A., Balkanay M., Berki T., Iik Ö, Yakut C. Overhung technique for repair of aortic root. IXth Annual Turkish and German Joint Symposium on Cardiovascular Surgery and Cardiology 1997:10-12.
ik Ô, Kirali K., Tuncer A., Ömerôglu S.N., Toker M.E., pek G. Comparison between Bentall, and flanged techniques. VII. Aortic Surgery Symposium 2000:27-28.
This article has been cited by other articles:
|
|
 |
|
  M. Stalder, S. Staffelbach, F. F. Immer, L. Englberger, P. A. Berdat, F. S. Eckstein, and T. P. Carrel Aortic Root Replacement Does Not Affect Outcome and Quality of Life Ann. Thorac. Surg., September 1, 2007; 84(3): 775 - 781. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A Ghavidel, M. B Tabatabaei, M. A Yousefnia, G.-R. Omrani, N. Givtaj, and K. Raesi Mortality and Morbidity After Aortic Root Replacement: 10-Year Experience Asian Cardiovasc Thorac Ann, December 1, 2006; 14(6): 462 - 466. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Hirasawa, S. Aomi, S. Saito, S. Kihara, H. Tomioka, and H. Kurosawa Long-term results of modified Bentall procedure using flanged composite aortic prosthesis and separately interposed coronary graft technique Interactive CardioVascular and Thoracic Surgery, October 1, 2006; 5(5): 574 - 577. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. A. Hopkins Aortic valve leaflet sparing and salvage surgery: evolution of techniques for aortic root reconstruction Eur. J. Cardiothorac. Surg., December 1, 2003; 24(6): 886 - 897. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Kurisu, Y. Ochiai, T. Kajiwara, H. Kumeda, and R. Tominaga A modified valve-on-valve approach for aortic root replacement Ann. Thorac. Surg., December 1, 2003; 76(6): 2099 - 2101. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Kirali, V. Erentug, M. B Rabus, A. Izgi, N. U Bozbuga, K. Erkanli, E. Akinci, and C. Yakut Extensive Aortic Surgery in Marfan Syndrome: 16-Year Experience Asian Cardiovasc Thorac Ann, December 1, 2003; 11(4): 337 - 341. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
