Electronic ISSN 2287-0237
Acute type A aortic dissection is a life-threatening vascular emergency and requires urgent surgical intervention. Though surgical techniques have been improved for more than ten years, the mortality rate remains high. Therefore, the initial diagnosis and treatment is extremely significant for survival since its immediate mortality rate is as high as 1% per hour over the earliest hours.1
There are several techniques of cardiopulmonary bypass (CPB) for aortic cannulation: femoral artery cannulation, axillary artery cannulation, and transapical aortic cannulation. The most important of all aortic cannulation sites is the perfusion into the true lumen.
In the case of acute type A acute aortic dissection, many institutes and the cardiac surgeons have chosen the femoral artery for aortic cannulation since the CPB is easily and quickly established in the case of hemodynamic instability. However, the femoral artery cannulation is not always appropriate due to malperfusion of the aorta and it can lead to cerebral embolism from dislodged debris tissue in patients who have severe atheromatous changes in the thoracic aorta.
The axillary artery has been used as the perfusion route thanks to the length of the retrograde perfusion is being shorter than the femoral artery and it is also used for antegrade cerebral perfusion during circulatory arrest.
Another perfusion route is the transapical aortic cannulation mentioned in this article. The most important aims for all aortic cannulation routes are blood perfusion into the true lumen and prevention the damage of the vital organs.
The study investigated 12 years’ of surgery experience in acute type A acute aortic dissection by transapical aortic cannulation Technique. This study was approved and reviewed by the ethical committee of at Kawasaki Saiwai Hospital, Kawasaki, Japan.
Surgical Technique
Firstly, bicaval cannulation was performed for venous drainage, and retrograde cardioplegia was applied to the coronary sinus. After that, a 1 cm incision was made in the apex of the left ventricle (muscular part) lateral to the left anterior descending coronary artery (LAD) and a 24-F cannula (Kurary® thin wall catheter; Kurary Co.; Osaka, Japan) was passed through the apex and across the aortic valve to lie in the proximal ascending aorta. The tip of the cannula was in the sinus of valsalva. trans-esophageal echocardiogram (TEE) was used to check the position of the cannula tip, ensuring an accurate position in the true lumen and avoiding manipulation of the ascending aorta.
A left ventricular vent was created through the right superior pulmonary vein before the cardiopulmonary bypass was established. In most cases of acute type A aortic dissection, we used deep hypothermic circulatory arrest with retrograde cerebral perfusion (RCP) and antegrade selective cerebral perfusion (SCP) as an adjunctive measure for cerebral protection. After circulatory arrest was achieved, the apical cannula was removed.
Later, RCP was started; aortotomy was performed and distal trimming was conducted to prepare for distal anastomosis. Next, SCP was inserted into the right brachiocephalic artery and RCP was stopped. Then, distal anastomosis was repaired with one branch graft. After the anastomosis was repaired, CPB was reestablished through the branch graft for aortic return, so the distal anastomosis was checked for leakage before rewarming was started.2 Finally, the incision in the left ventricular apex was closed with 5-0 polypropylene interrupted sutures, while the proximal anastomosis was performed above the Sinotubular Junction (STJ) about 10 mm.
Indications for Transapical Aortic Cannulation
Contraindication for Transapical Aortic Cannulation
Statistical Analysis
Data was processed using STATA statistic data analysis Version 11.0 software (StataCrop LP, 4905 Lakeway Drive, College Staton, Texus 77845-4512, USA). Continuous values were expressed as the mean ± standard deviation. Risk factor relevant variables with p < 0.05 on univariate analysis were incorporated into the multivariate models. Cox proportional hazard regression analysis was employed for risk ratio and Kaplan Meier curve for the survival time. Differences were considered statistically significant at p < 0.05.
Study Population
From June 2003 to September 2014, a total of 309 patients with acute type A aortic dissection underwent transapical aortic cannulation technique were investigated.
Inclusion criteria: Patients with a diagnosis of acute type A aortic dissection operated by transapical aortic cannulation technique were enrolled. The CPB that were used included deep hypothermic circulatory arrest (DHCA), DHCA with RCP, DHCA with antegrade selective cerebral perfusion (SCP), and DHCA with RCP and SCP. Exclusion criteria: Patients whose femoral artery or the axillary artery was used for aortic cannulation were excluded.
The study population (n = 309) was analyzed for survival rate. The person-time was 6363.50 person/month. The death totaled 29 patients (9.38%). The mortality rate was 4.55/1000 person/month (95% confidence interval = 3.17-6.56/1000 person/month).
The study population comprised 179 males (57.93%) and 130 females (42.07%). The mean average age by SD was 65.12 ± 13.77 years, and the glomerular filtration rate (GFR) was 70.17 ± 36.52 ml/min/1.73 m.2
The average ejection fraction (EF %) was 59.48 ± 8.11, Size of Sinus of Valsalva was 36.67 ± 5.18 mm, sinotubular junction was 33.43 ± 6.05 mm, ascending aorta diameter was 46.70 ± 6.53 mm, aortic arch diameter was 35.62 ± 5.79 mm and proximal descending aorta diameter was 32.61 ± 4.61 mm (Table 1).
The CPB used included DHCA, RCP, SCP, and DHCA with RCP and SCP. Operation time was 432.67 ± 123.35 minutes, CPB time was 235.16 ± 79.73 minutes, Cross clamp time was 176.02 ± 62.91 minutes, Circulatory arrest time was 61.44 ± 19.38 minutes, RCP time was 46.30 ± 20.88 minutes, SCP time was 16.54 ± 31.95 minutes and brain ischemic time was 25.05 ± 26.98 minutes. Temperature was controlled and measured at Rectal temperature of 22.72 ± 1.71 oC, Bladder temperature of 22.43 ± 1.98 oC and tympanic membrane temperature of 17.38 ± 1.71 oC (Table 1).
Table 1: Demographics and general characteristic of participants in the study
The confounding factors were controlled by using Cox proportional hazard regression analysis and other factors influencing survival rate and risk factors (Table 2). In this study, the population of; the female group had had a higher rate of death with adjusted hazard ratio (AHR), 95% confidence interval (95% CI) = 0.81 and 0.25-2.61. The coronary artery disease (CAD) and nonCAD group had AHR and 95% CI = 7.27 and 1.17-45.17 (Figure 1), respectively.
The preoperative hemodynamic deterioration and non-preoperative hemodynamic deterioration group had AHR and 95% CI = 4.10 and 1.04-16.24 (Figure 2), respectively. In the operative procedure groups: the total arch replacement (TAR) had AHR and 95% CI = 5.01 and 1.12-23.14, while the Aortic Root Replacement (ARR) had AHR and 95% CI = 2.88 and 0.21-40.23; comparable to Transapical Aortic Cannulation Technique the hemiarch replacement (HAR) group (Figure 3). The CPB group was compared among DHCA, DHCA combined with RCP, DHCA combined with SCP and DHCA combined with RCP and SCP groups, indicating AHR and 95% CI = 11.89 and 1.30-108.74 (Figure 4).
Regarding the enlargement of the ascending aortic diameter and proximal descending aorta diameter, the death rates were AHR and 95% CI = 1.11 and 1.02-1.21, AHR and 95% CI = 1.18 and 1.07-1.03, respectively when the diameter expanded each 1 mm. The results of operation times were AHR and 95% CI = 1.01 and1.00-1.01 when the operation time extended each 1 minute. Concerning the natural histology of the aortic wall group: the atherosclerosis compared with the degenerative group had AHR and 95% CI = 4.23 and 0.99-18.00 (Figure 5), respectively; that was marginally significant (Table 3).
Transapical Aortic Cannulation Technique
Table 2: Percentage of pain reduction at each follow-up period.
Table 3: Univariate and multivariate analysis of risk factors in Acute Type A Aortic Dissection
Figure 1: Kaplan-Meier curves show the comparison of patients with coronary artery disease and non-coronary artery disease: AHR and 95% CI = 7.27 and 1.17-45.17 (p ≤ 0.05), respectively.
Figure 2: Kaplan-Meier curves show the comparison of patients with preoperative hemodynamic deterioration and non-preoperative deterioration: AHR and 95% CI = 4.10 and 1.04-16.24 (p ≤ 0.05), respectively.
Figure 3: Kaplan-Meier curves show the comparison of the Total Arch Replacement (TAR) and Aortic-Root Replacement (ARR) to hemiarch replacement (HAR): AHR at 95% CI = 5.01 and 1.12-23.14, AHR at 95% CI = 2.88 and 0.21-40.23, AHR at 95% CI = 1, -, - (p ≤ 0.05), respectively
Figure 4: Kaplan-Meier curves show the Deep Hypothermic circulatory arrest (DHCA) combined with RCP (Retrograde cerebral perfusion) and SCP (Antegrade selective cerebral perfusion). Compared to DHCA or DHCA and RCP or DHCA and SCP: AHR and 95% CI = 11.89 and 1.30- 108.74. AHR and 95% CI = 1, -, - (p ≤ 0.05), respectively.
Figure 5: Kaplan-Meier curves show the comparison of the patients with atherosclerosis and dissection with degenerative: AHR at 95% CI = 4.23 and 0.99-18.00, AHR at 95% CI = 4.32 and 0.83-22.43, AHR and 95% CI = 1, -, - ( p ≤ 0.05), respectively.
Femoral artery cannulation is the standard option in many cases because CPB is established quickly, in the case of hemodynamic instability.4,5 It presents the highest rate of mortality including stroke, retrograde cerebral embolization, organ malperfusion and perfusion into the false lumen.6 Reuthebuch and co-authors reported that the extension of dissection to the cerebral vessel, ascending aorta, and infrarenal abdominal aorta presented a mortality rate of 23.3% and was higher in the femoral cannulation group.7 Reece et al.,8 Chiappini el al.,9 Moizumi et al.,10 and Nourael et al.11 reported mortality rates of 23%, 17%, 22%, 30% and 40%, respectively; in femoral cannulation groups. Recently, the axillary artery has been increasingly used for perfusion route. A number of reports have noted different mortality rates between the axillary and femoral cannulation. Tiwari KK et al.13 reported that femoral artery cannulation had a higher mortality from 6.5% to 40%., while 3% to 8.6% for axillary artery cannulation, and 0%-15% for direct aortic cannulation.12-14 Kamiya et al.15 used direct ascending aortic cannulation and percutaneous femoral artery cannulation. The result showed that the femoral artery cannulation had higher mortality.
Khaladj et al.16 reported direct ascending aortic cannulation: the cannula tip was inserted by the Seldinger method and placed in the true lumen under the guidance of epiaortic echo or TEE.17,18 The innominate artery19 or carotid artery20 has also been used for the perfusion route, but rarely. Besides, the left ventricular apex has been used (Transapical Aortic Cannulation approach).21,22 Zwart et al.23 reported that retrograde passage of a cannula across the aortic valve was used as a part of the left ventricular support system. Though, this technique presented a success rate over 90% in cases of Acute Type A Aortic Dissection; the Transapical Cannulation was safer and simpler than femoral cannulation.24
The risk factors influencing the survival rate in Acute Type A Aortic Dissection included CAD, Preoperative Hemodynamic
The authors wish to thank Kawasaki Saiwai Hospital, Kawasaki, Japan and the willingly support from all of our patients.
