Purpose: To achieve good outcomes during aortic surgery with circulatory arrest, a secure and non-bleeding anastomosis must be achieved rapidly to ensure brain protection. We report our initial experiences with a modified Branched Graft Inverting (BGI) technique using an inserter under mild hypothermia. We aimed to reduce the surgical duration and to prevent unnecessary damage to the fragile aorta. Methods: We retrospectively reviewed patients with type A acute aortic dissection (AAD) who underwent distal anastomosis via the modified BGI technique using an inserter between January 2012 and March 2013. Open distal anastomosis was performed under mild hypothermia with right hemisphere perfusion from the right axillary artery. Results: Eight patients were enrolled. There was no mortality. Circulatory arrest time was reproducibly 20.3 ± 1.9 min, which was sufficient to complete non-bleeding distal anastomoses. The average rectal temperature during circulatory arrest was 26.5℃ ± 1.9℃. All patients were extubated the day after the operation without any neurological deficit. Conclusion: The modified BGI technique employing an inserter and mild hypothermia offered easy, secure, and reproducible distal anastomosis for ascending aortic replacement for type A acute aortic dissection. Our outcomes were favorable and support further development of this technique.
To achieve good outcomes during aortic surgery with circulatory arrest, such as open distal anastomosis for type A acute aortic dissection, a secure and non-bleeding anastomosis must be achieved rapidly to ensure brain protection. Typically, a two-step method is adopted that involves aortic stump reinforcement and graft anastomosis, which can prolong both the surgical duration and circulatory arrest time. The extent of aortic replacement and surgical duration have been reported as significant risk factors for hospital mortality [
The use of an inverted graft that was invaginated into an injection syringe before being atraumatically injected into the aorta, yielded promising results [
This was a retrospective observational study reporting our initial experiences with a modified BGI technique using an inserter under mild hypothermia. The modified technique employed an inserter designed to allow reinforcement of the aortic stump while simultaneously performing distal graft anastomosis. The primary outcome was to determine feasibility of the technique, and the secondary outcomes were the safety and operative parameters. We retrospectively reviewed the medical records of all the patients before surgery. Additionally, all patients received contrast-enhanced computed tomography (CT) followed by transthoracic echocardiography to detect pericardial effusion, aortic valve regurgitation (AR), and to assess cardiac function. Data were expressed as mean ± standard deviation for continuous variables and as percentages for categorical variables.
We enrolled patients who underwent ascending aortic replacement for acute aortic dissection using the modified BGI technique at our institution between April 2012 and April 2013. Patients were excluded if they required aortic arch replacement or had severe atherosclerotic changes in the aortic arch.
A single branched 26 mm Triplex graft (Terumo Corp, Tokyo, Japan) was cut 4 cm proximal and 2 cm distal to the branch, resulting in a total length of approximately 7 cm. Further, the graft was completely inverted (
(a) Preparation of the graft. The branched graft is cut and completely inverted; (b) The inverted graft is invaginated into the severed syringe and prepared for deployment; (c) By withdrawing the barrel with the plunger fixed, the graft is atraumatically placed in the aorta
The right axillary and femoral arteries were cannulated for perfusion. Cardiopulmonary bypass was initiated with right atrial drainage. Next, cooling was initiated, during which the ascending aorta was cross-clamped, and the proximal stump of the aorta was reinforced and anastomosed with a graft. When the core temperature reached 26˚C, the carotid branches were clamped and circulatory arrest was initiated. Right cerebral hemisphere perfusion was continued from the right brachial artery for selective cerebral perfusion.
The ascending aorta was transected 1 cm proximal to the origin of the brachiocephalic artery. Next, we carefully introduced the inserter holding the inverted graft into the aorta. After withdrawing the syringe barrel with the plunger fixed, the inverted graft was placed in the aorta (
After insertion the graft was evenly fixed using four felt-pledgeted sutures. Distal anastomosis was performed using 3 - 0 polypropylene running sutures buttressed with a Teflon felt strip outside the aorta (
We identified 8 patients who met the inclusion and exclusion criteria; their preoperative profiles are shown in
There were no mortalities. Although open distal anastomosis with the BGI technique was performed by 4 different surgeons (including a resident), the circulatory arrest time was short at 20.3 ± 1.9 min (range, 18 - 24 min) (
Postoperative complications were minimal. There were no neurologic complications related to surgical
The distal anastomosis performed after insertion of the inverted graft into the aorta
. Preoperative patient characteristics and complications.
Demographics | |
---|---|
age (years) | 62.1 ± 6.4 |
Sex (male:female) | 6:02 |
Preoperative complication | |
Occlusion type | 0 |
AR | 4(50%) |
shock by cardiac tamponade | 1(12.5%) |
AMI | 0 |
Brachiocephalic artery occlusion | 2 |
coronary dissection | 1 |
CRF | 0 |
Cerebral ischemia | 2(25%) |
. CA time by 4 surgeon performing BGI technique.
Pt | CA (min) | Operator |
---|---|---|
1 | 19 | Chief |
2 | 22 | Surgeon A |
3 | 20 | Surgeon A |
4 | 23 | Surgeon B |
5 | 22 | Surgeon B |
6 | 18 | Chief |
7 | 23 | Surgeon A |
8 | 24 | Surgeon C |
procedures and no re-operations to control bleeding. All patients were extubated the day after surgery without neurological deficit. One patient developed a stroke 12 days postoperatively.
The mean duration of stay in the intensive care unit was 3.7 ± 1.9 days, and the mean duration of hospitalization was 14.0 days. Related procedures included fixation of detached aortic commissures (n = 4), brachiocephalic artery reconstruction (n = 2), and coronary artery bypass grafting (n = 1).
The extent of aortic replacement and surgical duration are significant risk factors for hospital mortality [
It is possible that our results were favorable because of the target level and duration of hypothermia. Indeed, we had no bleeding or neurological complications as stated. The evidence now suggests that decreasing the systemic temperature to below 22˚C may be unnecessary and associated with a higher incidence of neurologic injury during DHT [
Although this modified BGI technique can lessen the impact of surgery and hypothermia related stress, it cannot be used for severely atherosclerotic or “shaggy” aortas because of the risk of embolism. However, it is sometimes difficult to insert an inverted graft into a fragile dissected aorta, and the aortic arch can be damaged if the graft is inserted without care. The use of an injection syringe for graft insertion in non-bleeding anastomoses was successful in this regard. This is because the inverted graft is invaginated into an injection syringe and atraumatically injected into the aorta [
Finally, this study does have limitations. Notably, the sample size was small (n = 8), the study was not controlled, and we performed no statistical analysis. Consequently, the present data are insufficient to claim definitively that this procedure is effective. However, this study does provide the foundation for further investigation.
Our technique offers an easy, secure, and reproducible method for performing non-bleeding distal anastomosis. We could secure non-bleeding anastomosis within 20 min, ensuring safe circulatory arrest under mild hypothermia. Shorter circulatory arrest times and mild hypothermia probably contributed to the low rate of postoperative complications. Therefore, we consider that under mild hypothermia, this technique was useful for ascending aortic replacement in type A acute aortic dissection. However, further studies with larger cohorts that compare outcomes against the standard procedure are necessary to confirm these initial findings.
The author declares no conflicts of interest.