Root Reconstruction with Total Replacement of Ascending Aorta Using Hypothermic Circulatory Arrest and Selective Cerebral Perfusion for Moderately Dilated Distal Ascending Aorta

doi:10.4236/wjcs.2013.33018

Paper Menu >>

Journal Menu >>

World Journal of Cardiovascular Surgery, 2013, 3, 101-105

http://dx.doi.org/10.4236/wjcs.2013.33018 Published Online July 2013 (http://www.scirp.org/journal/wjcs)

Root Reconstruction with Total Replacement of

Ascending Aorta Using Hypothermic Circulatory

Arrest and Selective Cerebral Perfusion for

Moderately Dilated Distal Ascending Aorta

Satoshi Yamashiro*, Ryoko Arakaki, Yuya Kise, Hitoshi Inafuku, Yukio Kuniyoshi

Department of Thoracic and Cardiovascular Surgery, University of the Ryukyus, Nishihara, Okinawa, Japan

Email: *[email protected]

Received June 3, 2013; revised July 3, 2013; accepted July 10, 2013

cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Objective: We have occasionally encountered a moderately dilated distal ascending aorta while reconstructing an aortic

root. We describe reconstruction of an extended root and ascending aorta using our current strategy. Patients and

Methods: Between March 2011 and December 2012, 15 (11 men; mean age, 70.1 ± 7.3 years) patients underwent root

reconstruction with hemi-arch replacement under hypothermic circulatory arrest with antegrade selective cerebral per-

fusion. The maximum diameter of the aortic root was 52.5 ± 4.4 mm. The distal ascending aorta just below innominate

artery was moderately dilated to 41.7 ± 1.4 mm in diameter. Results: Operative outcomes excluding the diameter of the

distal ascending aorta did not significantly differ from those of patients who had undergone root reconstruction under

distal ascending aortic clamping during the same period. Postoperative computed tomography confirmed complete re-

section of the dilated ascending aorta in the patients, and did not develop neurological dysfunction or stroke. Conclu-

sion: Postoperative computed tomography confirmed complete resection of dilated ascending aortae. We considered

that complete resection under hypothermic circulatory arrest and selective cerebral perfusion might help to avoid re-

peated surgery to treat dilation of the distal ascending aorta over the long-term.

Keywords: Annulo-Aortic Ectasia; Re-Operation

1. Introduction

Ascending aorta replacement is the most common strat-

egy for treating thoracic aortic pathologies. Graft repla-

cement for an ascending aortic aneurysm is now a rela-

tively safe and standard surgical procedure. However,

management of a mildly to moderately dilated ascending

aorta during cardiac surgery remains controversial. We

have encountered some patients with a moderately di-

lated distal ascending aorta during aortic root reconstruc-

tion. Distal anastomosis of the ascending aorta usually

proceeds under aortic clamping, when a dilated distal

ascending aorta would remain. The most important con-

sequence of an enlarged ascending aortic dimension is a

proportional increase in the incidence of aortic rupture,

dissection and re-operation. We have routinely wrapped

borderline dilated distal ascending aortae with prosthetic

grafts or felt strips to prevent dilation over the long term.

However, we have recently replaced moderately dilated

ascending aortae (hemi-arch replacement), using open

distal anastomosis for complete resection.

2. Patients and Methods

Between March 2011 and December 2012, 15 patients

(11 men and 4 women; mean age, 70.1 ± 7.3 years) un-

derwent root reconstruction with total replacement of a

dilated ascending aorta under hypothermic circulatory

arrest (HCA) with antegrade selective cerebral perfusion

(ASCP), (HCA group). The ascending aorta was comple-

tely resected just below the innominate artery (hemi-arch

group). All patients were preoperatively diagnosed by

computed tomography (CT), angiography and ultrasound

cardiography as having annulo-aortic ectasia (AAE) with

aortic regurgitation (AR). The maximum aortic root di-

ameter was 52.5 ± 4.4 mm. The distal ascending aorta

just below the innominate artery was moderately dilated

*Corresponding a uthor.

S. YAMASHIRO ET AL.

102

to 41.7 ± 1.4 mm in diameter. The root was reconstructed

using the modified Bentall (n = 11) and David (n = 4)

procedures.

The cerebral circulation of all patients undergoing

elective surgery was preoperatively evaluated by Doppler

ultrasonogr aphy of the extracr anial vessels and by digital

subtraction angiography of the extracranial and intracra-

nial circulation. A cardiopulmonary bypass (CPB) was

established with ascending aortic and right axillary arte-

rial cannulation for arterial inflow and right atrial drain-

age. Core cooling was started during CPB to generate

hypothermia over a period of 30 - 40 minutes, during

which, the proximal repair proceeded. The circulation

was arrested when the electroencephalogram flat-lined.

With the patient in the Trendelenberg position, 12 Fr

malleable perfusion cannulae connected to an oxygenator

by a separate single-roller pump head were inserted into

the left common carotid and left subclavian arteries

through the aortic lumen. The cannula in the right axil-

lary artery was used for righ t-sided ASCP with proximal

brachio-cephalic artery clamping using another single-

roller pump. Cerebral perfusion was started at a rate of

10 - 15 mL/min/kg and adjusted to maintain left radial

arterial pressure and bilateral carotid arterial stump pres-

sure between 40 and 60 mmHg. Perioperative blood flow

through the middle cerebral arteries was continuously

monitored using bilateral transcranial Doppler (Viasys

Inc. Conshocken, PA, USA) ultrasonography. Cerebral

oxygen saturation was monitored using an Invos cere-

bral oximeter (Somanetics Co., Troy, MI, USA). Distal

repair proceeded via open distal anastomosis with a sin-

gle-branched Dacron graft. Both HCA and ASCP were

terminated after reconstructing the distal ascending aorta

with antegrade perfusion from the graft branch and then

the proximal repair was completed during rewarming.

Finally, the proximal and distal grafts were anastomosed.

We compared the surgical results with those of pa-

tients whose root reconstruction had proceeded under

distal ascending aortic clamping during the same period

(Clamp group). We also compared postoperative CT

findings with those of patients who had a moderately

dilated distal ascending aorta that had bee n w rapped.

Continuous data are expressed as means ± SD, and

categorical variables are expressed as ratios (%). Char-

acteristics were compared between the two groups using

Student’s t-test.

3. Results

The durations of surgery, total CPB, cardiac ischemia,

ASCP and HCA were 445.6 ± 42.7, 239.9 ± 30.9, 211.3

± 28.2, 33.9 ± 5.9 and 33.0 ± 5.1 minutes, respectively,

in the HCA group. Rectal temperature in these patients

was maintained at 25.4˚C ± 1.6˚C during HCA. Opera-

tive outcomes excluding the diameter of the distal as-

cending aorta (41.5 ± 1.4 vs. 35.4 ± 2.8 mm) and the

lowest rectal temperature during operation (25.4 ± 1.6 vs.

30.6˚C ± 3.7˚C) did not significantly differ from those of

the Clamp group (Table 1).

Neurological dysfunction and postoperative stroke did

not arise in this series. Mechanical ventilation was re-

Table 1. Patient’s characteristics and operative outcomes.

Group HCA group (n = 15) Clamp group (n = 8) P value

Age (years old) 70.1 ± 7.3 65.5 ± 13.9

Gender (M/F) 11/4 7/1

Max Asc Ao. diameter (mm) 52.0 ± 5.7 49.8 ± 10.4

Distal Asc Ao. diamet e r (mm) 41.5 ± 1.4 35.4 ± 2.8 P = 0. 04

Surgical duration (min) 445.6 ± 42.7 505.9 ± 131.6

CPB time (min) 239.9 ± 31.9 253.4 ± 73.6

Cardiac arrest time (min) 211.3 ± 28.7 217.4 ± 67.0

Bleeding (ml) 692.2 ± 298.2 769.0 ± 454.6

Blood Transfusion (ml) 2017.7 ± 698.0 1965.0 ± 1021.0

Rectal temp (˚C) 25.4 ± 1.6 30.6 ± 3.7 P = 0.04

Respiratory time (hours) 12.2 ± 4.2 13.8 ± 5.0

Morbidity 0 1; respiratory failure (12.5%)

Hospitalization (POD; days) 26.2 ± 5.9 35.6 ± 15.1

HCA group: patients underwent root reconstruction with total replacement of the ascending aorta under hypothermic circulatory arrest (HCA) with antegrade

selective cerebral perfusion (ASCP); Clamp group: patients proceeded root reconstruction under distal ascending aortic clamping; Asc Ao.: ascending aorta;

CP: cardiopulmonary bypass; POD: post-operative days. B

S. YAMASHIRO ET AL. 103

quired after surgery for 12.2 ± 4.2 hours. Postoperative

CT confirmed complete resection of the dilated ascend-

ing aorta (Figures 1 and 2). However, the distal ascend-

ing aorta clearly remained dilated after clamping (previ-

ous patients; Figure 3). All patients remained in hospital

for 26.2 ± 5.9 days after surgery. Aetiology of aortic an-

eurysm of this series were not significant different be-

tween both groups (Table 2).

4. Discussion

Although the results of surgical intervention of the tho-

racic aorta have gradually improved, hospital mortality

rates as well as neurological and systemic complications

remain considerable [1]. Therefore, management of the

mildly to moderately dilated ascending aorta has re-

mained controversial. In general, surgery with concomi-

tant cardiovascular procedures especially involving the

Table 2. Aetiology of aneurysms.

HCA group Clamp group

Atherosclerotic change 8 (53.3%) 4 (50.0%)

Degenerative change 6 (40.0%) 3 (37.5%)

Central medial n e c rosis 2 (13.3%) 1 (12.5%)

Aortitis 1 (6.7%) 1 (12.5%)

Bicuspid valve 1 (6.7%) 0

Marfan syndrome 0 1 (12.5%)

Figure 1. Postoperative computed tomography image after

hemi-arch replacement with hypothermic circulatory arrest

and antegrade selective cerebral perfusion. Dilated ascend-

ing aorta is completely resected (arrow).

David

(a) (b)

m-Bentall

Figure 2. Postoer

hemi-arch ry arrest

perative computed tomography image aft

replacement with hypothermic circulato

and antegrade selective cerebral perfusion. Dilated ascend-

ing aortae are completely resected after David procedure (a,

c) and modified-Bentall operation (b, d) (arrows).

(a) (b)

Figure 3. Posed tomo-

graphy ims dilated

e can proceed when aortic dilation is between

5 - 50 mm in diameter. We had previously wrapped

toperative three-dimensional comput

age. (a, b) Distal ascending aorta remain

after clamping for distal anastomosis of ascending aorta

(arrows).

aortic valv

borderline dilated distal ascending aortae with a felt or

prosthetic graft to prevent dilation over the long term.

Some reports have indicated that wrapping effectively

preserves dilated ascending aortae [2-4]. However, we

recently experienced a need to re-operate on a replaced

distal ascending aorta of a male patient that had become

dilated despite being wrapped with a prosthetic graft

(Figure 4). The distal ascending aorta at the initial op-

eration was moderately dilated to a diameter of 43 mm.

Thereafter, we considered that extensive replacement of

the dilated ascending aorta (hemi-arch replacement) us-

ing open distal anastomosis might have been a better

S. YAMASHIRO ET AL.

104

(a) (c)

(b) (d)

Figure 4. Pre- and post-operative computed tomography

images. (a) Aneurysmal dilation of ascending aorta to ma-

ximal diameter of 53 mm in with mildly dilated

distal asceal ascen-

ory management have evolved to in-

rease the safety and duration of cerebral protection.

niques include HCA alone, retrograde cerebral

sion in 1995, and found

operative CT

a patient

nding aorta; (b) Borderline dilated dist

ding aorta wrapped w ith felt; (c) Distal ascending aorta in-

cludes arch aorta enlarged (arrow) at one year after initial

operation; (d) Reconstructed vessel after repeated aortic

arch replacement.

choice.

Over the past 2 decades, various adjunctive techniques

of cerebral circulat

These tech

rfusion (RCP) with HCA, and ASCP with HCA. The

safe time period of HCA to prevent temporary neurologic

dysfunction has been reported to be less than 45 minutes

[5]. The safe duration of HCA is limited and prolonged

periods of HCA are associated with end-organ ischemia

and postoperative neurologic dysfunction [6]. Therefore,

further efforts to improve cerebral protection have led to

the development of antegrade and retrograde cerebral

perfusion. The optimal method of cerebral perfusion (an-

tegrade versus retrograde) is a well-debated topic and has

yet to be determined. RCP can be instituted easily ju st by

clamping the venous drainage tube of the inferior vena

cava, snaring the superior vena cava cannula, and coun-

ter-rotating the CPB pump. However, this method is as-

sociated with two major concerns: insufficient cerebral

oxygen supply and cerebral edema with increased intrac-

ranial pressure due to high venous pressure [7]. ASCP is

employed in many institutions but requires extra arterial

cannulation and, in some cases, an extra arterial pump;

thus, it is relatively complicated and time-consuming [8].

However, only about 20% of adults have anatomically

and functionally completed circle of Wills [9]. Therefor e,

we considered that bilateral ASCP might be unachievable

via unilateral carotid perfusion.

Both HCA with ASCP are currently being applied to

protect the brain. Svenson et al. [10] started applying a

subclavian or axillary artery cannulation strategy with

HCA and antegrade brain perfu

at it was a safe approach to aortic arch surgery because

the stroke risk was < 2%. Technical simplicity and

avoidance of aorta and arch vessel manipulation, as well

as a bloodless operative field, render DHCA an alterna-

tive method of brain protection, especially during as-

cending aorta hemi-arch replacement, when a short pe-

riod of circulatory arrest is anticipated. The advantages

of ASCP are that circulatory arrest can be safely ex-

tended up to 90 minutes, which allows more complex

aortic repair [11]. However, hypothermia-associated co-

agulopathy and pulmonary, renal and micro embolic

complications have been cited in the literature as impor-

tant disadvantages [11]. Rectal temperature in our series

was maintained at 25˚C during HCA and we did not find

an increased risk of coagulative complications. Moderate,

instead of profound hypothermia can reduce the risk of

coagulative and systemic complications. The degree of

hypothermia during this procedure should be considered

when a short period of circulatory arrest is anticipated.

Cerebral oximetry is a functional and possibly superior

method of monitoring cerebral perfusion and oxygena-

tion [12,13]. Although cerebral protection techniques are

continually undergo ing refinement with improved results,

we added left brain perfusion to minimize the likelihood

of associated brain damage arising [14]. Moreover, ver-

tebral perfusion via the left axillary artery is important

for spinal, as well as cerebral protection. Therefore, we

suppose that our method of cerebral protection is accep-

table. The optimal approach to cerebral protection during

these procedures remains controversial.

Indications for total arch replacement in patients with

mildly to moderately dilated ascending and arch aortae

are contentious because the surgical results of extended

arch replacement are suboptimal [15]. Post

vealed complete resection of the dilated ascending

aorta using our procedures. We considered that such

complete resection under HCA and ASCP might prevent

the need for re-operation to treat a dilated distal ascend-

ing aorta over the long term. Neither permanent neuro-

logical dysfunction nor postoperative stroke developed in

this series. Our results suggested that extensive reim-

plantation of the ascending aorta accompanied by ade-

quate HCA and AS CP is effective. Although this study is

limited by the relatively small patient cohort, our find-

ings might have practical implications for the evolution

S. YAMASHIRO ET AL.

105

D. Spielvogel, A. Apaygin, S. L. Lansman, J.

N. McCullough, J. D. Galla and R. B. Griepp, “Surgical

Treatment of a: When and

How?” The Ary, Vol. 67, No. 6

of controversial cases. Aetiology of aortic aneurysm of

this series was not significant different between both

groups. We considered that it is important to the distal

aortic diameter.

REFERENCES

[1] M. A. Ergin,

the Dilated Ascending Aort

nnals of Thoracic Surge,

1999, pp. 1834-1839.

doi:10.1016/S0003-4975(99)00439-7

[2] O. Cohen, J. Odim, D. D. L. Zerda, C. Ukatu, R. Vyas, N.

Vyas, K. Oaratnik and H. Laks, “Long Term Experience

of Girdling the Ascending Aorta with Dacron Mesh as

Definitive Treatment for Aneurismal Dilatation,” The

Annals of Thoracic Surgery, Vol. 83, No. 2, 2007, pp.

S780-S784. doi:10.1016/j.athoracsur.2006.10.086

[3] G. I. Tagarakis, D. Karangelis, A. Baddour, M. E. Daska-

lopouls, V. T. Liouras, D. Papadopoulos, K. Stamoulis, S.

S. Lampoura and N. B. Tsilimingas, “An Alternate Solu-

tion for the Treatment of Ascending Aortic Aneurysms:

The Wrapping Technique,” Journal of Cardiothoracic

Surgery, Vol. 5, 2010, p. 100.

doi:10.1186/1749-8090-5-100

[4] E. Tappainer, V. Fiorani, A. Nocchi, E. Likaj, S. Mem-

ishaj and M. Zogno, “Safe Wrapping of the Borderline

Dilated Ascending Aorta during Aortic Valve Replace-

ment,” Journal of Cardiothoracic Surgery, Vol. 2, 2007,

p. 15. doi:10.1186/1749-8090-2-15

[5] A. Gega, J. A. Rizzo, M. H. Johnson, M. Tranquilli, E. A.

Farkas and J. A. Elefteriades, “Straight Deeo Hypother-

mic Arrest: Experience in 394 Patients Supports Its Ef-

fectiveness as a Sole Means of Brain Preservation,” The

Annals of Thoracic Surgery, Vol. 84, No. 3, 2007, pp.

759-767. doi:10.1016/j.athoracsur.2007.04.107

[6] M. A. Ergin, J. D. Galla, S. L. Lansman, C. Quintana, C.

Bodian and R. B. Gripp, “Hypothermic Circulatory Arrest

in Operations on the Thoracic Aorta. Determinants of

Operative Mortality and Neurologic Outcome,” The Jour-

nal of Thoracic and Cardiovascular Surgery, Vol. 107,

No. 3, 1994, pp. 788-797.

[7] A. Usui, K. Oohara, T. L. Liu, M. Murase, M. Tanaka , E.

Takeuchi and T. Abe, “Determination of Optimum Ret-

rograde Cerebral Perfusion Conditions,” The Journal of

Thoracic and Cardiovascular Surgery, Vol. 107, No. 1,

1994, pp. 300-308.

[8] H. Ogino, H. Sasaki, K. Minatoya, H. Matsuda, H. Ta-

naka, H. Watanuki, M. Ando and S. Kitamura, “Evolving

Arch Surgery Using Integrated Selective Cerebral Perfu-

sion: Impact of Axillary Artery Perfusion,” The Journal

of Thoracic and Cardiovascular Surgery, Vol. 136, No. 3,

2008, pp. 641-648. doi:10.1016/j.jtcvs.2008.02.089

[9] S. Morita, M. Yasaka, K. Yasumori, Y. Oishi, T. Takase-

ya, H. Sonoda and T. Kawara, “Transcranial Doppler

Study to Assess Intracranial Arterial Communication be-

fore Aortic Arch Operation,” The Annals of Thoracic

Surgery, Vol. 86, No. 2, 2008, pp. 448-451.

doi:10.1016/j.athoracsur.2008.04.024

[10] L. G. Svenson, E. M. Nadolny, D. L. Penney, J.

W. A. Kimmel, M. H. Entrup and Jacobson,

R. S. D’Agostino,

“Prospective Randomized Neurocognitive and S-100

Study of Hypothermic Circulatory Arrest, Retrograde

Brain Perfusion, and Antegrade Brain Perfusion for Aor-

tic Arch Operations,” The Annals of Thoracic Surgery,

Vol. 71, No. 6, 2001, pp. 1905-1912.

doi:10.1016/S0003-4975(01)02570-X

[11] M. Eusanio, R. M. J. Wesselink, W.

Dossche and M. A. A. M. Schpens, “D

Morsunis, K. M.

eep Hypothermic

Circulatory Arrest and Antegrade Selective Cerebral Per-

fusion during Ascending Aorta-Hemiarch Replacement:

A Retrospective Comparative Study,” The Journal of

Thoracic and Cardiovascular Surgery, Vol. 125, No. 4,

2003, pp. 849-854. doi:10.1067/mtc.2003.8

[12] N. Fassiadis, H. Zayed, H. Rashid and D. W. Green, “In-

vos Cerebral Oximeter Compared with the Transcranial

k and J. C. Stanley, “Evaluation of a Cerebral Oxi-

Doppler for Monitoring Adequacy of Cerebral Perfusion

in Patients Undergoing Carotid Endarterectomy,” Inter-

national Journal of Angiology, Vol. 25, 2006, pp. 401-

406.

[13] S. K. Samra, E. A. Dy, K. Welch, P. Dorje, G. B. Ze-

lenoc

meter as a Monitor of Cerebral Ischemia during Carotid

Endarterectomy,” Anesthesiology, Vol. 93, No. 4, 2000,

pp. 964-970. doi:10.1097/00000542-200010000-00015

[14] S. Yamashiro, Y. Kuniyoshi, K. Arakaki, H. Inafuku, Y.

Morishima and Y. Kise, “Total Arch Replacement Using

ns for Elective Surgi-

Bilateral Axillary Antegrade Selective Cerebral Perfu-

sion,” Annals of Thoracic and Cardiovascular Surgery,

Vol. 16, No. 4, 2010, pp. 216-219.

[15] R. Codecasa, M. A. Mariani, A. D’Alfonso, C. Nardi and

J. G. Grandjean, “Current indicatio

cal Treatment of Dilated Ascending Aorta: A New For-

mula,” Annals of Thoracic and Cardiovascular Surger,

Vol. 125, No. 6, 2003, pp. 1528-1530.

doi:10.1016/S0022-5223(03)00059-X