Currently, aortic dissection is associated with a high mortality

Efficacy and Pitfalls of Transapical Cannulation for the Repair of Acute Type A Aortic Dissection Akihito Matsushita, MD, Susumu Manabe, MD, Minoru Tabata, MD, MPH, Toshihiro Fukui, MD, Tomoki Shimokawa, MD, and Shuichiro Takanashi, MD Department of Cardiovascular Surgery, Sakakibara Heart Institute; and Department of Cardiovascular Surgery, Teikyo University Hospital, Tokyo, Japan Background. Selection of a cannulation site for the repair of acute type A aortic dissection remains controversial. Several cannulation sites have been introduced, but each is associated with a risk of adverse complications. Transapical cannulation is a simple procedure to restore antegrade blood flow during ECC. However the efficacy of this procedure is unknown. Methods. Among 400 patients undergoing surgical repair of acute type A dissection at Sakakibara Heart Institute between 2003 and 2010, transapical cannulation was performed in 52 patients, and these patients were included in this study. Transapical cannulation was selected as the initial cannulation site in 44 patients and as conversion from femoral cannulation in 8 patients. Results. There were 4 in-hospital mortalities (mortality rate, 7.7%) and 5 patients had strokes (stroke rate, 9.6%). Transapical cannulation was successful in 47 patients (90.4%). Conversion of the cannulation site was necessary in 5 patients: Malperfusion on initiation of ECC was observed in 4 patients and emergence of aortic regurgitation was observed in 1 patient. The cannula was moved to another artery for correction in these patients. There was no mortality in patients undergoing conversion of the cannulation site. Conclusions. Transapical cannulation is considered an effective option for the repair of acute type A aortic dissection. Transapical cannulation cannot eliminate the risk of intraoperative malperfusion, and therefore careful assessment with intraoperative monitoring is necessary. (Ann Thorac Surg 2012;93:1905 9) 2012 by The Society of Thoracic Surgeons Currently, aortic dissection is associated with a high mortality rate [1], and one of its serious complications is organ malperfusion [2, 3]. In particular, in the setting of surgical procedures it is sometimes difficult to reconstruct safe extracorporeal circulation (ECC) providing sufficient blood flow to every organ [4]. Intraoperative malperfusion syndrome (IMS) is associated with a drastic flow change in ECC [5, 6]. The initiation of ECC can trigger newly developed malperfusion [7], and the selection of the cannulation site is considered important to avoid IMS [8]. The standard cannulation sites in the surgical repair of type A aortic dissection are the femoral artery [9] and axillary artery [10, 11], but both arteries are associated with the risk of IMS [7, 12, 13]. Transapical cannulation has been reported as a preferable approach to restore antegrade blood flow during ECC [14, 15]. For patients with severe atherosclerotic change in the distal aorta, antegrade blood flow may avoid the cerebral emboli because of retrograde perfusion from the femoral artery. Moreover the absence of drastic flow change after initiation of ECC may decrease the risk of IMS. However only a few studies have investigated the efficacy of this procedure [14, 15]. The adverse consequences of transapical cannulation have not been reported. Therefore, the purpose of this study was to Accepted for publication Feb 10, 2012. Address correspondence to Dr Manabe, MD, Department of Cardiovascular Surgery, Teikyo University Hospital, Kaga 2-11-1, Itabashi, Tokyo 183-0003, Japan; e-mail: s-manabe@fb3.so-net.ne.jp. investigate the efficacy of transapical cannulation for repair of acute type A aortic dissection. Patients and Methods Study Subjects Between January 2003 and December 2010, surgical repair of acute type A dissection was performed in 400 patients at Sakakibara Heart Institute. Our strategy of selection of the cannulation site was as follows: (1) the femoral artery was the standard cannulation site unless there was a contraindication; (2) the contraindications for femoral artery cannulation were distal aortic aneurysm, iliofemoral disease, femoral artery dissection, and the presence of limb ischemia; and (3) transapical cannulation was the second option. Over 8 years, the femoral artery was selected as the initial cannulation site in 342 patients, and transapical cannulation was selected in 44 patients. Other cannulation sites were selected in 14 patients (ascending aorta in 12 patients and subclavian artery in 2 patients) (Fig 1). The cannulation site was converted from the femoral artery to transapical aortic cannulation in 8 patients because of IMS. The total number of patients undergoing transapical cannulation was 52, and these patients were compared with 348 patients who did not undergo transapical cannulation. All preoperative data, in-hospital outcomes, and postoperative data were collected from patient medical records. The Ethics Committee of the Sakakibara Heart Institute 2012 by The Society of Thoracic Surgeons 0003-4975/$36.00 Published by Elsevier Inc doi:10.1016/j.athoracsur.2012.02.036

1906 MATSUSHITA ET AL Ann Thorac Surg EFFICACY OF TRANSAPICAL CANNULATION 2012;93:1905 9 Total number of pa ents n=400 Ini al cannula on site Ascending aorta Subclavian artery Femoral artery Apex of le ventricle n=12 n=2 n=342 n=44 Conversion due to IMS n=8 Pa ents without transapical cannula on n=348 Pa ents with transapical cannula on n=52 Fig 1. Selection algorithm of cannulation site. (IMS intraoperative malperfusion syndrome.) approved this study, waived the need for patient consent, and provided approval before publication of the data. Operative Procedure Ascending aortic replacement was performed in 27 patients, hemiarch replacement in 3 patients, total arch replacement in 21 patients, and aortic root replacement with valve sparing in 1 patient. Retrograde cerebral perfusion was used for ascending, hemiarch, or aortic root replacement. Selective antegrade cerebral perfusion was used for total arch replacement. Cooling to a rectal temperature of 25 C was initiated. After cerebral perfu- Table 1. Preoperative Patient Characteristics Variables Total With TA Without TA p Value a Patient number 400 52 348 Age (years) 65.3 13.0 65.7 13.8 65.1 13.0 0.601 Male 209 (52.3%) 36 (69.2%) 173 (49.7%) 0.008 Hypertension 351 (87.8%) 50 (96.2%) 301 (86.5%) 0.079 Hyperlipidemia 66 (16.5%) 6 (11.5%) 60 (17.2%) 0.404 History of cerebral infarction 42 (10.5%) 5 (9.6%) 37 (10.6%) 0.984 History of ischemic heart disease 30 (7.5%) 4 (7.7%) 26 (7.5%) 0.341 Thoracic aneurysm 25 (6.3%) 6 (11.5%) 19 (5.5%) 0.166 Marfan syndrome 11 (2.8%) 0 (0%) 11 (3.2%) 0.397 Shock status 73 (18.3%) 11 (21.2%) 62 (17.8%) 0.561 Cardiac tamponade 91 (22.8%) 13 (25.0%) 78 (22.4%) 0.678 Aortic regurgitation (moderate or more) 45 (11.3%) 5 (9.6%) 40 (11.5%) 0.869 Renal failure (creatinine level 2.0mg/dL) 5 (1.3%) 1 (1.9%) 4 (1.1%) 0.840 Respiratory failure (preoperative intubation) 35 (8.8%) 4 (7.7%) 31 (8.9%) 0.979 Organ ischemia Myocardial 24 (6.0%) 3 (5.8%) 21 (6.0%) 0.811 Cerebral 17 (4.3%) 3 (5.8%) 14 (4.0%) 0.830 Intestinal 8 (2.0%) 1 (1.9%) 7 (2.0%) 0.625 Upper extremity 18 (4.5%) 3 (5.8%) 18 (5.2%) 0.908 Lower extremity 26 (6.5%) 8 (15.4%) 18 (5.2%) 0.012 a With TA versus without TA. TA transapical cannulation.

Ann Thorac Surg MATSUSHITA ET AL 2012;93:1905 9 EFFICACY OF TRANSAPICAL CANNULATION 1907 Table 2. Criteria for Selection of Transapical Cannulation Reasons Cases (n 52) Distal aortic aneurysm 25 (48.1%) Distal aortic arch to descending aorta 8 (15.4%) Abdominal aorta 17 (32.7%) Iliofemoral disease 3 (5.8%) Femoral arterial dissection 10 (19.2%) Lower limb ischemia 6 (11.5%) Conversion from femoral artery 8 (15.4%) sion, ECC was reestablished through a branched graft. Concomitant procedures included coronary artery bypass in 4 patients, aortoaxillary bypass in 1 patient, and femorofemoral bypass in 1 patient. Monitoring Methods Intraoperative monitoring was performed to detect the development of organ malperfusion. The arterial pressure of both radial arteries was routinely monitored. Transesophageal echocardiography (TEE) was monitored by a board-certified anesthesiologist and cardiologist. Particular attention was paid at the timing of the initiation of ECC and aortic clamping. We evaluated blood flow in the true lumen. IMS is highly suspected in patients with an abrupt drop in blood pressure in the radial artery or an abrupt collapse of the true lumen. When IMS developed, ECC was immediately discontinued. Cardiac output was obtained immediately in most patients after discontinuation of ECC. We then changed the cannulation site and attempted to reestablish ECC with the new cannulation site. Procedure of Transapical Cannulation After right atrial cannulation for venous drainage, a 1-cm incision was made in the apex of the left ventricle without a purse-string suture, and a 7-mm diameter cannula (Sarns Soft-Flow 4948 Extended Aortic Cannulae, Terumo) with a stylet was passed through the apex and across the aortic valve until it was positioned in the ascending aorta with transesophageal echocardiographic guidance. It was confirmed that the catheter tip was positioned in the true lumen, and the position of the catheter tip was at the level of the sinotubular junction. Perfusion was started, and the position of the cannula was verified again with TEE. After the main operative procedure was performed, the incision in the left ventricular apex was closed with a few 4-0 polyvinylidene fluoride (Asflex, Crownjun, Chiba, Japan) interrupted sutures with felt pledgets. Statistical Analysis Categorical variables were reported as percentages, and continuous variables were reported as mean standard deviation. Differences between groups were compared using the 2 test for categorical variables and the Student s t test for continuous variables. Statistical significance was accepted at p less than 0.05. All statistical analyses were performed using SPSS statistical software, version 17.0. (SPSS Software Japan, Tokyo, Japan). Results Operative Outcomes The patients backgrounds are shown in Table 1. The reasons for the selection of transapical cannulation are shown in Table 2. The study included 8 patients in whom the cannulation site was converted from the femoral artery because of the development of IMS. Among 52 patients in whom transapical cannulation was used, ECC was completed successfully in 47 patients (90.4%). Postoperative morbidity and mortality are shown in Table 3. Four patients (7.7%) died in hospital. Causes of death were cerebral infarction in 3 patients and multiple organ failure in 1 patient. Five patients (9.6%) had cerebrovascular accidents. The incidence of acute renal failure and respiratory failure were higher in patients who underwent transapical cannulation than in those who did not. Conversion from Transapical Cannulation Conversion from transapical cannulation was necessary in 5 patients. IMS was observed in 4 patients, and the exacerbation of aortic insufficiency was observed in 1 Table 3. Clinical Results Variables Total N 400 With TA n 52 Without TA n 348 p Value a In-hospital mortality 15 (3.8%) 4 (7.7%) 11 (3.2%) 0.225 Cerebral complication 56 (14.0%) 8 (15.4%) 48 (13.8%) Permanent 28 (7.0%) 5 (9.6%) 23 (6.6%) 0.616 Transient 28 (7.0%) 3 (5.8%) 25 (7.2%) 0.934 Acute renal failure (creatinine 2.0mg/dL) 29 (7.3%) 9 (17.3%) 20 (5.7%) 0.006 Respiratory failure (ventilation 24 hours) 66 (16.5%) 16 (18.3%) 50 (14.4%) 0.002 Revision for bleeding 19 (4.8%) 3 (5.8%) 16 (4.6%) 0.983 Mediastinitis 14 (3.5%) 1 (1.9%) 13 (3.7%) 0.795 a With TA versus without TA. TA transapical cannulation.

1908 MATSUSHITA ET AL Ann Thorac Surg EFFICACY OF TRANSAPICAL CANNULATION 2012;93:1905 9 Table 4. Patient Characteristics in Conversion from Transapical Cannulation Patient Age (y) Sex Performed Operation Entry Site Secondary Cannulation Site Findings in Site Intraoperative Monitoring 1 74 Female Ascending Ascending Right SCA Abrupt BP disappearance in the right RA 2 79 Female Hemiarch Proximal arch. Right FA Newly developed aortic regurgitation in TEE 3 54 Male Ascending Ascending Right FA Obstruction of the true lumen in TEE 4 67 Female Total arch Distal arch Right FA Abrupt BP disappearance in the right RA 5 67 Female Ascending Ascending Right FA Abrupt BP disappearance in the left RA Obstruction of the true lumen in TEE BP blood pressure; FA femoral artery; RA radial artery; SCA subclavian artery; TEE transesophageal echocardiography. patient. Patient characteristics, performed procedures, and the situation at conversion are shown in Table 4. The cannula was safely switched to the subclavian or femoral artery for correction in these patients. There was no mortality in patients undergoing conversion of the cannulation site. Comment The present study reviewed the surgical experience of transapical cannulation in 52 patients. ECC was completed through the left ventricular apex in 47 patients (90.4%), and the operative procedure was performed with acceptable short-term results. Conversion of the cannulation site was necessary in 5 patients. The development of IMS could be immediately detected by intraoperative monitoring and could be successfully treated by switching the cannulation site. The optimal cannulation site for the repair of acute ascending aortic dissection is still controversial because all the cannulation sites are associated with the risk of adverse complications [12]. Transapical cannulation is a simple procedure. Insertion of the cannula through the apex of the left ventricle is not technically demanding and takes only a few minutes to establish ECC. Several studies have reported the efficacy of transapical cannulation for the repair of type A aortic dissection [14, 15]. In the present study, the first choice for the cannulation site was the femoral artery. Transapical cannulation was used for patients with contraindications to femoral artery cannulation. For patients with distal aortic aneurysm, femoral artery cannulation is associated with the risk of retrograde cerebral emboli [8]. We performed transapical cannulation in 25 patients with distal aortic aneurysm. The clinical results in these patients were acceptable (stroke rate, 8.0%; in-hospital mortality rate, 0%). We also performed transapical cannulation in 8 patients who experienced IMS with femoral artery cannulation. IMS was avoided by switching the cannulation site, and there were no intraoperative complications in these patients. These results suggested that transapical cannulation is an effective option, especially for patients with contraindications to femoral artery cannulation. IMS is a serious complication in the surgical treatment of aortic dissection [2, 3], and all the cannulation sites are associated with the risk of IMS [12]. The incidence of IMS with femoral artery cannulation has been reported to be 2.5% to 13% [9, 12]. Previous studies have suggested that transapical cannulation is effective for avoiding IMS because it can restore antegrade blood flow during ECC Fig 2. Echocardiographic sequences of intraoperative malperfusion syndrome (IMS) in patients undergoing transapical cannulation. (A) Before the initiation of ECC. (B) After the insertion of the cannula (arrow) through the apex of the left ventricle. The cannula was identified in the true lumen of the ascending aorta. (C) After initiation of ECC. A false lumen expanded abruptly. (D) After discontinuation of ECC. Expansion of the false lumen was diminished. (ECC extracorporeal circulation.)

Ann Thorac Surg MATSUSHITA ET AL 2012;93:1905 9 EFFICACY OF TRANSAPICAL CANNULATION 1909 Our preliminary results need to be confirmed by studies of larger groups of patients. Fig 3. Intraoperative macroscopic findings. A large entry point (arrow) existed in the ascending aorta. Thin and thick arrows indicate the locations of entry site and aortic valve, respectively. [14, 15]. In the present study, however, we reported 4 patients who experienced IMS because of transapical cannulation. The typical sequence of transesophageal echocardiographic images showing IMS resulting from transapical cannulation is shown in Figure 2. In this patient, blood pressure in the right radial artery abruptly disappeared immediately after the initiation of ECC, and a high perfusion pressure in the circuit of the heart-lung machine could not maintain sufficient ECC. TEE showed abrupt expansion of the false lumen (Fig 2C). Discontinuation of ECC resulted in the restoration of cardiac output and IMS resolved. ECC was reestablished through the femoral artery, and the operation was completed uneventfully. Intraoperative macroscopic findings revealed a large entry tear located in the proximal part of ascending aorta, and the blood flow of ECC might enter the false lumen through this large entry tear (Fig 3). Our study demonstrated that transapical cannulation is also associated with the risk of IMS, especially for patients with a large entry in the ascending aorta. Therefore all cannulation sites are associated with the risk of IMS, and careful intraoperative monitoring is important to detect IMS. Study Limitations This was a single-institution retrospective study, which could have had significant bias, especially in patient selection. Another limitation was the number of patients; the total number of patients enrolled was relatively small. References 1. Trimarchi S, Nienaber CA, Rampoldi V, et al. Contemporary results of surgery in acute type A aortic dissection: the international registry of acute aortic dissection experience. J Thorac Cardiovasc Surg 2005;129:112 22. 2. Geirsson A, Szeto WY, Pochettino A, et al. Significance of malperfusion syndromes prior to contemporary surgical repair for acute type A dissection: outcomes and need for additional revascularizations. Eur J Cardiothorac Surg 2007; 32:255 62. 3. Yagdi T, Atay Y, Engin C, et al. Impact of organ malperfusion mortality and morbidity in acute type A aortic dissections. J Card Surg 2006;21:363 9. 4. Shimokawa T, Takanashi S, Ozawa N, et al. Management of intraoperative malperfusion syndrome using femoral artery cannulation for repair of acute type A aortic dissection. Ann Thorac Surg 2008;85:1619 24. 5. Parr GVS, Manley NJ, Williams DR, et al. Obstruction of the true lumen during retrograde perfusion of type I aortic dissections: a simplified solution. Ann Thorac Surg 1980;30: 495 8. 6. Robicsek F, Guarino RL. Compression of the true lumen by retrograde perfusion during repair of aortic dissection. J Cardiovasc Surg 1985;26:36 40. 7. Voci P, Giovanni T, Tritapepe, et al. Detection of false lumen perfusion at the beginning of cardiopulmonary bypass in patients undergoing repair of aortic dissection. Crit Care Med 2000; 28:1841 6. 8. Svensson LG, Blackstone EH, Rajeswaran J, et al. Does the arterial cannulation site for circulatory arrest influence stroke risk? Ann Thorac Surg 2004;78:1274 84. 9. Fusco DS, Shaw RK, Tranquilli M, et al. Femoral cannulation is safe for type A dissection repair. Ann Thorac Surg 2004; 78:1285 9. 10. Moizumi Y, Motoyoshi N, Sakuma K, Yoshida S. Axillary artery cannulation improves operative results for acute type A aortic dissection. Ann Thorac Surg 2005;80:77 83. 11. Sinclair MC, Singer RL, Manleyv NJ, Montesano RM. Cannulation of the axillary artery for cardiopulmonary bypass: safeguards and pitfalls. Ann Thorac Surg 2003;75:931 4. 12. Gulbins H, Pritisanac A, Ennker J. Axillary versus femoral cannulation for aortic surgery: enough evidence for a general recommendation? Ann Thorac Surg 2007;83:1219 24. 13. Schachner T, Nagiller J, Zimmer A, Laufer G, Bonatti J. Technical problems and complications of axillary artery cannulation. Eur J Cardiothorac Surg 2005;27:634 7. 14. Flege JB, Aberg T. Transventricular aortic cannulation for repair of aortic dissection. Ann Thorac Surg 2001;72:955 6. 15. Wada S, Yamamoto S, Honda J, et al. Transapical aortic cannulation for cardiopulmonary bypass in type A aortic dissection operations. J Thorac Cardiovasc Surg 2006;132: 369 72.