*Correspondence:
Saeid Hosseini, MD, FETCS
Heart Valve Diseases Research Center, Rajaie Cardiovascular Medical, and
Research Center, Iran University of Medical Sciences, Tehran, Iran
Cell Phone: +98 912 201 41 81
Fax: +98 21 220 420 26
Tel: +98 21 2392 2193
Address: Valiasr Ave, Niayesh Intersection, Tehran, Iran
Postal code: 1995614331
Funding: None
Disclosure : None
Keywords : Frozen Elephant Trunk, FET, Hybrid Arch Replacement,
Circulatory Arrest, Commentary
The advent of Frozen elephant trunk (FET) has revolutionized aortic arch
repair and also further approaches to pathologies involving descending
aorta, providing a single-stage treatment of both arch and descending
aorta. A large body of evidence published previously reported short- and
long-term outcomes of
FET1. However, a
potential shortcoming of this technique is the necessity of a complex
arch replacement which is accompanied by adverse events mainly
neurologic and renal failure due to circulatory arrest.
Although moderate hypothermic circulatory arrest (MHCA) with selective
cerebral perfusion (SCP) offers an equivalent visceral and cerebral
protection during arch procedures compared with deep hypothermic
circulatory arrest (DHCA), an immense attempt has been made to reduce
MHCA time achieving a lower incidence of visceral ischemic complications
as well as renal impairment after
FET.2
At the same time with the introduction of the newer generations of FET3, other series
published results of modifications in FET procedure to address the
unsolved problem of circulatory arrest time. With newer FET generations,
approaching distal anastomosis has been targeted along with
well-established, safer surgical technique adjustment (i.e.
proximalization of distal anastomosis from zone 3 to zone 2 or even to
zone 1 or 0 ) 45. Aortic occlusion
balloons, also an adjunct, is being utilized to achieve lower
circulatory arrest time with earlier restoration of lower body perfusion
before completing distal anastomosis6.Nevertheless, newer
generations of FET devices coupled with increasingly FET experiences
prevent popularity of aortic balloon occlusion as it anticipated.
We read with great interest Piperata et al. article on (Evaluation of
the “release and perfuse technique” for aortic arch
surgery)7. They reported
their result using a modified technique named “release and perfuse
Technique (RPT)”. The primary rationale behind their proposed approach
was to minimize lower body circulatory arrest
time.7 The authors
described their technique during aortic arch replacement under MHCA plus
SACP. They also cited previous attempts published to reduce lower body
circulatory arrest time as mentioned above. This adjunct procedures
seems to be more valuable in stringent and particular situations with
minimum exposure of zone 2 or zone 3 which the surgeon finds hardship
with such as re-do operations or huge aneurysmal sac repair, as well as
aortic dissections in emergency settings.
A recent meta-analysis conducted by Cao et
al8 observed a lower
incidence of renal failure and need for renal replacement therapy in
MHCA comparing to DHCA when the lower body circulatory arrest time was
less than 30 minutes but a similar pooled incidence this complication in
both groups for longer than 30 minutes. This 30 minutes period for an
aortic surgeon adequately allows insertion of FET conduit along with
safe and hemostatic anastomosis of its collar, generally. Hence,
reducing the lower body circulatory arrest time by performing RPT in
expense of potential backflow bleeding around a stented portion of FET
and as the result, some difficulty in suturing of the FET‘s collar, is
not the optimal choice. Visceral organ protection is also well achieved
by lowering core body temperature because of reduced metabolism rate and
oxygen demand along with catching of more safe circulatory arrest time.
However, it prolongs operative time needless to say that due to more
time needed for cooling and rewarming.
Accordingly, Wang and colleagues studied on over a thousand patients who
underwent aortic arch surgery requiring hypothermic circulatory arrest9. The authors reported
a mean of 24 minutes for lower body circulatory arrest. When compared
with 14 minutes of lower body circulatory arrest time described by
Piperata in their technique, a reduction of 10 minutes in time of
performing distal anastomosis is a potential benefit. Although this
10-minutes period should be justified against risk of troublesome
intra-operative bleeding in the prospective clinical trials.
In addition, their approach which entailed release of the stented graft
and restoring distal blood flow through the fourth branch of FET for
restoring lower body perfusion would be potentially beneficial in
selected patient cohort with proper sizing to have good sealing. As the
authors did this RPT method in 18 patients from the total 44 cases of
FET in their cases. Except for patients with a proper sealing zone in
the thoracic aorta, surgeons will encounter troublesome back bleeding
around the stented portion into the suturing area.
Altogether, it is appropriate that we add this approach to the
armamentarium of aortic arch repair using FET for optimal outcomes for
patients and surgeons equally.
References:
1. Rezaei Y, Bashir M, Mousavizadeh M,
Daliri M, Aljadayel HA, Mohammed I, et al. Frozen elephant trunk in
total arch replacement: a systematic review and meta‐analysis of
outcomes and aortic proximalization. Journal of Cardiac Surgery. 2021;
36:1922-34.
2. Pupovac SS, Hemli JM, Bavaria JE,
Patel HJ, Trimarchi S, Pacini D, et al. Moderate Versus Deep Hypothermia
in Type A Acute Aortic Dissection Repair: Insights from the
International Registry of Acute Aortic Dissection. Ann Thorac Surg.
2021; 112:1893-9.
3. Tsagakis K, Jakob H. Which frozen
elephant trunk offers the optimal solution? Reflections from Essen
group. Seminars in Thoracic and Cardiovascular Surgery; 2019: Elsevier.
4. Mousavizadeh M, Bashir M, Jubouri
M, Tan SZ, Borzeshi EZ, Ilkhani S, et al. Zone proximilisation in frozen
elephant trunk. What is the optimal zone for open intervention? A
systematic review & meta-analysis. The Journal of cardiovascular
surgery. 2022.
5. Tsagakis K, Osswald A, Weymann A,
Demircioglu A, Schmack B, Wendt D, et al. The frozen elephant trunk
technique: impact of proximalization and the four-sites perfusion
technique. European Journal of Cardio-Thoracic Surgery. 2022;
61:195-203.
6. Sun X, Guo H, Liu Y, Li Y. The
aortic balloon occlusion technique in total arch replacement with frozen
elephant trunk. European Journal of Cardio-Thoracic Surgery. 2019;
55:1219-21.
7. Piperata A, d’Ostrevy N, Busuttil
O, Pernot M. How to minimize the circulatory arrest time by using the
Thoraflex Hybrid prosthesis: the ’release and perfuse’ technique. Eur J
Cardiothorac Surg. 2021; 61:235-7.
8. Cao L, Guo X, Jia Y, Yang L, Wang
H, Yuan S. Effect of Deep Hypothermic Circulatory Arrest Versus Moderate
Hypothermic Circulatory Arrest in Aortic Arch Surgery on Postoperative
Renal Function: A Systematic Review and Meta-Analysis. Journal of the
American Heart Association. 2020; 9:e017939.
9. Wang X, Yang F, Zhu J, Liu Y, Sun
L, Hou X. Aortic arch surgery with hypothermic circulatory arrest and
unilateral antegrade cerebral perfusion: perioperative outcomes. The
Journal of Thoracic and Cardiovascular Surgery. 2020; 159:374-87. e4.