Repair of the initial tear is the most crucial step in the

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1 Total Aortic Arch Grafting for Acute Type A Dissection: Analysis of Residual False Lumen Yoshiharu Takahara, MD, Yoshio Sudo, MD, Kenzi Mogi, MD, Mituyuki Nakayama, MD, and Manabu Sakurai, MD Division of Cardiovascular Surgery, Funabashi Municipal Medical Center, Funabashi, Japan Background. In surgery for acute type A dissection, an unresected dissection and residual false lumina are causes of the progression of aneurysms and ruptures. We grafted the ascending aorta and total arch, the maximum grafting possible through a median sternotomy alone, in all patients with type A dissection extending to the descending aorta, wherever initial tears existed in the arch. Methods. A total of 37 consecutive patients with acute type A dissection underwent ascending and total arch grafting between August 1994 and December Cerebral protection was achieved by selective cerebral perfusion. The distal anastomosis was conducted using the Elephant Trunk technique. Patent false lumina were evaluated using computed tomography 3 months after the operation. Results. The hospital mortality was 8.1%. No major cerebral complications were observed. The incidence of residual thoracic patent false lumina was 26.5%. Univariate analyses showed Marfan syndrome and preoperative extension of false lumina to be statistically significant determinants of residual thoracic false lumina. On multivariate analysis, no other significant independent predictor of residual false lumina in the thoracic aorta was found. Conclusions. Outcomes of our strategy were satisfactory. However, residual thoracic false lumina could not be prevented in 26.5% of the patients. Thus, this extended operation is indicated in patients with initial tears in the aortic arch or distal arch, those with Marfan syndrome, and young patients with preoperative patent false lumina extending to the abdominal aorta. (Ann Thorac Surg 2002;73:450 4) 2002 by The Society of Thoracic Surgeons Repair of the initial tear is the most crucial step in the surgical treatment of aortic dissections. In the operation for acute type A (Stanford classification) aortic dissection extending to the transverse aortic arch and descending aorta, ascending aortic replacement is appropriate for patients whose initial tears exist in the ascending aorta. Proximal hemiarch replacement is appropriate for patients whose initial tears exist in the proximal aortic arch, and ascending aorta and total aortic arch replacement is appropriate for patients whose initial tears exist in the aortic arch or distal aortic arch [1 8]. However, an unresected dissected aorta and the residual false lumen are frequent causes of operative bleeding as well as progression of aneurysms and ruptures. We replaced the ascending aorta and total aortic arch, the maximum graft replacement possible through a median sternotomy alone, in all patients with type A dissection extending to the transverse aortic arch, wherever the initial tear existed in the arch. The surgical results and the patent residual false lumina were evaluated postoperatively. Accepted for publication Oct 16, Address reprint requests to Dr Takahara, Division of Cardiovascular Surgery, Funabashi Municipal Medical Center, , Kanasugi, Funabashi, Chiba, Japan ; yosh193@attglobal.net. Material and Methods From August 1994 to December 2000, a total of 48 consecutive patients with type A aortic dissection underwent grafting of the thoracic aorta in our hospital. All patients were in the acute stage within 2 weeks after onset. Eleven patients with ascending and proximal aortic arch dissection underwent grafting of the ascending aorta under hypothermic circulatory arrest. The other 37 patients with aortic dissection extending to the descending aorta underwent grafting of the ascending and total aortic arch using hypothermic selective cerebral perfusion. Of these 37 patients, who ranged in age from 31 to 75 years, 24 were men and 13 were women. There were 3 patients with Marfan syndrome. In terms of preoperative complications, 2 patients had neurologic symptoms, 4 had acute leg ischemia, 9 severe acute aortic valve insufficiency, 2 acute myocardial infarction, 8 cardiac tamponade, and 2 aortic rupture. Ten patients were in states of preshock or shock (Table 1). All patients underwent preoperative computed tomography (CT) with contrast enhancement. Those patients who survived the operation underwent evaluation of the patent residual false lumen using CT with contrast enhancement 3 months after the operation. Follow-up data were obtained from clinic visits in 97.3% of patients. The mean follow-up time was months by The Society of Thoracic Surgeons /02/$22.00 Published by Elsevier Science Inc PII S (01)

2 Ann Thorac Surg TAKAHARA ET AL 2002;73:450 4 TOTAL ARCH GRAFTING FOR TYPE A DISSECTION 451 Table 1. Patient Profiles Sex (male/female) 24/13 Age range (y) Mean SD Marfan syndrome (%) 3 (8.1) Preoperative complications (%) Neurologic symptoms 2 (5.4) Acute leg ischemia 4 (10.8) Sever aortic valve insufficiency 9 (24.3) Acute myocardial infarction 2 (5.4) Cardiac tamponade 8 (21.6) Aortic rupture 2 (5.4) Preshock or shock 10 (27.0) Surgical Technique All operations were performed under hypothermic selective cerebral perfusion (20 C). Arterial cannulation of the systemic circulation was performed to the femoral artery and venous cannulation to the right atrium. Cardiopulmonary bypass was started and the body temperature was cooled down to 20%. The arterial cannulations of the selective cerebral perfusion were performed to the right brachio-cephalic artery, left carotid artery, and left axillary artery. The left axillary artery was prepared through a small incision on the left axillary area. In patients whose dissection extended to the aortic arch branches, arterial cannulas were inserted directly through the aortic arch lumen internally under hypothermic circulatory arrest. While the body temperature was cooled down, ascending aortic cross-clamping and cardioplegia was performed. The proximal ascending aorta was trimmed. The surrounding continuous mattress suture was performed on the edge of the proximal aorta with Teflon (Impra Inc, subsidiary of L. R. Bard, Tempe, AZ) felt strips on both the inside and outside. From April 1996, the dissection lumen was fixed by gelatin-resorcine-formaldehyde (GRF) glue [2, 9]. Cerebral perfusion pressure was adjusted to maintain a right radial pressure of 40 to 70 mm Hg. The total blood flow rate of the selective cerebral perfusion was 10 ml kg 1 min 1, and carbon dioxide gas was added to the cerebral perfusion [10]. The aortic arch was resected and the distal aortic anastomosis performed using the open aortic technique. Trimming in the descending aorta was performed using the same method as for the ascending aorta. The four-branch aortic arch graft was used. In the distal aortic anastomosis, we used the Elephant Trunk technique [11, 12]. The trunk (5 cm in length) to be used was invaginated retrogradely into the aortic arch graft of the distal side before the distal anastomosis. After the anastomosis the trunk was extended to the descending aorta and advanced downstream. If the true lumen of the descending aorta was too small to accommodate the arch graft, we used another, smaller graft for the trunk. Antegrade systemic perfusion was started through one of the graft branches. The ascending aortic anastomosis and aortic arch reconstruction using the other three graft branches were performed during rewarming. Procedures performed concomitantly were 7 cases of aortic root replacement, 1 case of aortic valve suspension, 2 cases of coronary arterial bypass surgery, and 3 cases of femoro-femoral bypass. Aortic root replacement using Carrel s button technique [13], aortic valve suspension, and coronary arterial bypass surgery were performed during cooling down with cardiopulmonary bypass. The femoro-femoral bypass for acute leg ischemia was performed after cardiopulmonary bypass. Statistical Analysis Continuous data are expressed as mean SD. All statistical analyses were completed using the SPSS Base 8.0J software package (SPSS, Chicago, IL). Measurements considered for calculations are listed in Table 2. Univariate analyses were based on the 2 test. Continuous variables were analyzed with logistic regression. Multivariate analysis was performed by a stepwise multivariable logistic regression model. A p value of 0.05 or less was considered statistically significant. Results For the 37 patients of this study, operative times ranged from 244 to 925 minutes (mean SD, minutes); cardiopulmonary bypass time ranged from 146 to 335 minutes (mean SD, minutes); aortic crossclamp time ranged from 57 to 213 minutes (mean SD, minutes); open distal time ranged from 22 to 77 minutes (mean SD, minutes); and selective cerebral perfusion time ranged from 47 to 172 minutes (mean SD, minutes). The hospital mortality rate was 8.1% (3 of 37). Hospital mortality was attributed to postoperative dysrhythmia, preoperative stroke, and myocardial infarction due to the dissection extending to distal coronary arteries. During the postoperative course, no patients had major stroke, Table 2. Univariate Analyses for Determinant of Residual False Lumina in the Thoracic Aorta Variable Positive (n 9) Negative (n 25) p Value Male sex 7 (78%) 17 (68%) Age (y) Marfan syndrome 2 (22%) Histology, CMD 5 (56%) 8 (32%) Preoperative patent false lumen Thoracic only 0 11 (44%) Up to supra RA 30 (33%) 15 (60%) GRF use 6 (67%) 22 (88%) Aortic root replacement 2 (22%) 5 (20%) Resection of initial tear 6 (67%) 21 (84%) CPB time (min) SCP time (min) Open distal time (min) CMD cystic median degeneration; CPB cardiopulmonary bypass; GRF gelatin-resorcine-formaldehyde glue; RA renal artery; SCP selective cerebral perfusion.

3 452 TAKAHARA ET AL Ann Thorac Surg TOTAL ARCH GRAFTING FOR TYPE A DISSECTION 2002;73:450 4 Table 3. Patients With Residual Patent False Lumina in the Thoracic Aorta Sex Age (y) Marfan CMD Initial Tear GRF Preop PFL Postop PFL Follow-up (mo) 1 F 73 No No Arch No Supra RA Distal desc supra RA Lost (24) 2 M 31 No Yes Ascend No Infra RA Prox desc infra RA 5 cm MD (72) 3 M 50 Yes Yes Arch No Iliac A Prox desc iliac A Thoracoabdominal grafting (36) 4 M 47 Yes Yes Unclear Yes Iliac A Prox desc iliac A 5 cm MD (42) 5 M 66 No No Unclear Yes Supra RA Distal desc supra RA No change (40) 6 M 67 No No Unclear Yes Iliac A Prox desc iliac A 4.5 cm MD (36) 7 F 71 No Yes Arch Yes Infra RA Distal desc infra RA No change (32) 8 M 31 No Yes Ascend Yes Iliac A Prox desc iliac A No change (29) 9 M 34 No Yes Ascend Yes Supra RA Prox desc supra RA No change (20) Ascend ascending aorta; CMD cystic median degeneration; desc descending aorta; F female; GRF use of gelatin-resorcineformaldehyde glue; M male; MD maximum diameter of thoracic aneurysm; PFL patent false lumen; prox proximal; RA renal artery. although 2 patients experienced temporary paralysis and 1 patient temporary convulsions. Three patients had pneumonia. Five patients required prolonged postoperative mechanical ventilation for more than 48 hours. The mean length of postoperative mechanical ventilation was hours. The mean length of stay in the intensive care unit was days, and the mean postoperative hospital stay was days. In postoperative evaluations of the false lumina using CT, 9 patients (26.5%) had patent residual thoracoabdominal false lumina (Table 3). One patient, who had Marfan syndrome, had undergone the thoracoabdominal grafting for connecting the elephant trunk 3 years after the initial operation, and 3 patients had progression of their aneurysms. No late deaths have been reported to date. Among the other 25 patients (73.5%), there were no patent residual false lumina on the thoracic aorta. These patients ranged in age from 31 to75 years (mean years); 17 were men and 8 were women. There were no cases of Marfan syndrome; however, 8 patients had cystic median degeneration of the aortic wall. In the operation, the location of the initial tear was the ascending aorta in 12 patients and the aortic arch in 9, and was unclear in 4. Fourteen patients had no patent residual false lumina, and 11 patients had patent residual false lumina in the abdominal aorta only. Two patients succumbed to late death caused by cerebral infarction and pneumonia. No patients had progression of aneurysm or recurrent aortic dissection in the midterm follow-up. Preoperative and postoperative patent false lumina are shown in Table 4. Eleven patients had preoperative patent false lumina of the thoracic aorta only; this disappeared postoperatively in all of them. A total of 23 patients had thoracoabdominal patent false lumina preoperatively. After the operation, 3 patients had no residual patent false lumina; 14 patients had patent residual false lumina in the abdominal aorta only, and 9 had it in the thoracoabdominal aorta. Table 2 shows the results of univariate analyses for determining residual patent false lumina in the thoracic aorta. The only significant factors Marfan syndrome and preoperative extension of patent false lumina without the abdoninal aorta. On multivariate analysis, no other significant independent predictor of residual false lumina in the thoracic aorta was found. Comment In surgical treatment of acute type A aortic dissection, some previous reports have shown that ascending aortic grafting was necessary and that aortic arch grafting was also required whenever the initial tear existed in the aortic arch. The reported early mortality rates ranged from 7.9% to 36.1% [1, 3 7]. In particular, the early mortality rates of the simultaneous ascending aortic and arch grafting patients ranged from 21% to 34% [2, 3, 8, 14]. In current reports, however, this rate has improved to 6.0% [15], 7.1% [16], and 11% [17]. In our 48 consecutive patients with acute type A aortic dissection, the hospital mortality rate was 6.2% and 8.1% in the 37 patients undergoing grafting of the ascending and aortic arch. Among the patients undergoing the ascending aortic and arch grafting for type A dissection using hypothermic circulatory arrest, Bachet and colleagues [2] reported that the surgical mortality rate due to stroke was 11.5%, and Lansman and colleagues [3] reported that the cerebral complication rate was 13%. Recently, Coselli and associates [15] published data showing that the rate of stroke was 2.6%, and Hirotani and coworkers [17] reported no cerebral complications. On the other hand, selective cerebral perfusion has been regarded as a Table 4. Preoperative and Postoperative Patent False Lumen Preoperative Patent False Lumen Extending to None Postoperative Patent False Lumen Abdominal Only Thoracoabdominal Thoracic aorta Abdominal aorta supra renal artery infra renal artery Iliac artery 0 3 4

4 Ann Thorac Surg TAKAHARA ET AL 2002;73:450 4 TOTAL ARCH GRAFTING FOR TYPE A DISSECTION 453 useful method of cerebral protection during aortic arch grafting [14, 18]. In this study, there were no stroke patients, although 3 patients (8.1%) experienced temporary cerebral complications postoperatively. We can achieve a longer duration of safe cerebral protection using selective cerebral perfusion than we can using hypothermic circulatory arrest. Total arch grafting is usually conducted in patients whose initial tear exists in the aortic arch. However, in all patients with acute type A dissection extending to the descending aorta, we conducted ascending aortic and total arch grafting (the maximal graft replacement possible through a median sternotomy alone), and used the Elephant Trunk technique at the distal aortic anastomosis. This strategy aimed at extensive replacement of the dissecting aorta and prevention of the patent residual false lumen in the thoracic aorta. The Elephant Trunk technique prevents blood flow leakage into the dissecting lumen at the anastomosis site [19]. Some previous reports have shown that the patent rates of distal false lumina were 47.3% (Ergin and colleagues [20]) and 83.3% (Cachera and associates [1]) in patients of type A dissection after ascending aortic grafting. Ando and coworkers [16] reported that the patent rate of false lumina in the descending aorta was 39.4% in patients after ascending aortic and total arch grafting. In this study, the rate of residual patent false lumina in the thoracic aorta was 26.5%. Univariate analyses showed Marfan syndrome and preoperative patent false lumina extending to the thoracic aorta to be the only statistically significant determinants of residual false lumina in the thoracic aorta. On multivariate analysis, no other significant independent predictors of residual patent false lumina in the thoracic aorta were found. This strategy could not prevent residual patent thoracic false lumina in 26.5% of the patients in this study, and multivariate analysis showed no other significant factor of residual false lumina in the thoracic aorta. Thus, the usual indication of ascending and total arch grafting in patients with acute type A dissection is only an initial tear existing in the aortic arch or distal aortic arch. We contend that patients with Marfan syndrome and young patients with preoperative patent false lumina extending to the abdominal aorta may be good candidates for the total aortic arch grafting using the Elephant Trunk technique. These patients sometime require subsequent operation as well [21]. The grafting of the aortic arch and the descending aorta or the thoracoabdominal aorta must be conducted only after the ascending grafting in the subsequent operation. However, the grafting of the descending aorta or thoracoabdominal aorta through the left thoracotomy is chosen after the initial operation of total arch grafting. Total aortic arch grafting in the initial operation decreases the risk of the subsequent operation. The Elephant Trunk technique facilitates the proximal anastomosis in the subsequent operation as well [11, 12]. In conclusion, we conducted the grafting of the ascending aortic aorta and the aortic arch using the Elephant Trunk technique under selective cerebral perfusion in all patients with acute type A dissection extending to the descending aorta. The hospital mortality rate was 8.1% and there were no major cerebral complications. This strategy was aimed at prevention of the patent residual false lumen in the thoracic aorta. However, the rate of patent residual false lumina in the thoracic aorta was 26.5%. The benefits of this extended operation are the protection of the aortic arch rupture and a decrease in the risk of the subsequent operation. Thus, the indications for this extended operation are patients with initial tears in the aortic arch or distal arch, patients with Marfan syndrome, and young patients with preoperative patent false lumina extending to the abdominal aorta. References 1. Cachera J, Vouhe PR, Loisance DY, et al. Surgical management of acute dissections involving the ascending aorta. Early and late results in 38 patients. J Thorac Cardiovasc Surg 1981;82: Bachet J, Teodori G, Goudot B, et al. Replacement of the transverse aortic arch during emergency operations for type A acute dissection. Report of 26. J Thorac Cardiovasc Surg 1988;96: Lansman SL, Raissi S, Ergin MA, Griepp RB. Urgent operation for acute transverse aortic arch dissection. J Thorac Cardiovasc Surg 1989;97: Heiemann M, Laas J, Jurmann M, Karck M, Borst H. Surgery extended into aortic arch in acute type A dissection. Indication, techniques, and result. Circulation 1991;84(Suppl III): Crawford ES, Kirklin JW, Naftel DC, Svensson LG, Coselli JS, Safi HJ. Surgery for acute dissection of ascending aorta. Should the arch be included? J Thorac Cardiovasc Surg 1992; 104: Pansini S, Gagliardotto PV, Pompei E, et al. Early and late risk factors in surgical treatment of acute type A aortic dissection. Ann Thorac Surg 1998;66: Safi HJ, Miller CC, Reardon MJ, et al. Operation for acute and chronic aortic dissection: recent outcome with regard to neurologic deficit and early death. Ann Thorac Surg 1998;66: Massimo CG, Presenti LF, Marranci P, et al. Extended and total resection in the surgical treatment of acute type A aortic dissection: experience with 54 patients. Ann Thorac Surg 1988;46: Guilmet D, Bachet J, Goudot B, et al. Use of biological glue in acute aortic dissection. Preliminary clinical results with a new surgical technique. J Thorac Cardiovasc Surg 1979;77: Takahara Y, Sudo Y, Nakano T, Sato T. The effect of carbon dioxide tension cerebral circulation during hypothermic selective cerebral perfusion. J Cardiovasc Surg 2000;41: Borst HG, Schaps D. Extensive aortic replacement using Elephant Trunk prosthesis. Thorac Cardiovasc Surg 1983; 31: Heinemann MK, Buehner B, Jurmann MJ, Brost HG. Use of the Elephant Trunk Technique in aortic surgery. Ann Thorac Surg 1995;60: Miller DC, Stinson EB, Oyer PE, et al. Concomitant resection of ascending aortic aneurysm and replacement of the aortic valve. Operative and long-term results with conventional technique in ninety patients. J Thorac Cardiovasc Surg 1980;79: Kazui T, Kimura N, Yamada O, Komatsu S. Total arch graft

5 454 TAKAHARA ET AL Ann Thorac Surg TOTAL ARCH GRAFTING FOR TYPE A DISSECTION 2002;73:450 4 replacement in patients with acute type A aortic dissection. Ann Thorac Surg 1994;58: Coselli JS, Buket S, Djukanovic B. Aortic arch operation: current treatment and results. Ann Thorac Surg 1995;59: Ando M, Nakajima N, Adachi S, Nakaya M, Kawashima Y. Simultaneous graft replacement of the ascending aorta and total aortic arch for type A aortic dissection. Ann Thorac Surg 1994;57: Hirotani T, Kameda T, Kumamoto T, Shirota S. Results of a total aortic arch replacement for an acute aortic arch dissection. J Thorac Cardiovasc Surg 2000;120: Kazui T, Kimura N, Yamada O, Komatsu S. Surgical outcome of aortic aneurysms using selective cerebral perfusion. Ann Thorac Surg 1994;57: Ando M, Takamoto S, Okita Y, Morota T, Matsukawa R, Kitamura S. Elephant trunk procedure for surgical treatment of aortic dissection. Ann Thorac Surg 1998;66: Ergin MA, Philips RA, Galla JD, et al. Significance of distal false lumen after type A dissection repair. Ann Thorac Surg 1994;57: Moon MR, Sundt TM, Pasque MK, et al. Does the extent of proximal or distal resection influence outcome for type A dissections? Ann Thorac Surg 2001;71: Internet Discussion Forum The Annals of Thoracic Surgery Discussion Forum has resumed with a new format. Each month, we will select an article from The Annals for discussion within the Surgeon s Forum of the CTSNet Discussion Forum Section. The articles chosen will rotate among the six dilemma topics covered under the Surgeon s Forum, which include: General Thoracic Surgery, Adult Cardiac Surgery, Pediatric Cardiac Surgery, Cardiac Transplantation, Lung Transplantation, and Aortic and Vascular Surgery. Once the article selected for discussion is published in the online version of The Annals, we will post a notice on the CTSNet home page ( with a FREE LINK to the full-text article. Readers wishing to comment can post their own commentary in the discussion forum for that article, which will be informally moderated by The Annals Internet Editor. We encourage all surgeons to participate in this interesting exchange and to avail themselves of the other valuable features of the CTSNet Discussion Forum and web site. For February, the article chosen for discussion under the Adult Cardiac Surgery Dilemma Section of the Discussion Forum is: Prosthetic Replacement of Tricuspid Valve: Bioprosthetic or Mechanical Mehmet Kaplan, MD, Mustafa Sinan Kut, MD, Mahmut Murat Demirtas, MD, Serdar Cimen, MD, and Azmi Ozler, MD Tom R. Karl The Annals Internet Editor UCSF Children s Hospital Pediatric Cardiac Surgical Unit 505 Parnassus Ave, Room S-549 San Francisco, CA Phone: (415) Fax: (212) karlt@surgery.ucsf.edu by The Society of Thoracic Surgeons Ann Thorac Surg 2002;73: /02/$22.00 Published by Elsevier Science Inc