Arch-Clamping Technique Under Mild Hypothermia in Treating With Acute Type A Aortic Dissection

Beijing Anzhen Hospital306 enrolled

Overview

The study is a multicenter, three-arm, open-label, randomized, parallel-controlled trial, which plans to enroll 306 participants diagnosed with acute type A aortic dissection (ATAAD) from 7 hospitals in China. All patients receive total arch replacement (TAR) combined with frozen elephant trunk (FET) implantation and are randomized to Group 1 (arch-clamping technique under mild hypothermia), Group 2 (arch-clamping technique under moderate hypothermia) and Group 3 (Sun's procedure using bilateral antegrade cerebral perfusion) in the ratio of 1:1:1. After a 1-year follow-up, the validity and safety of the mild hypothermic arch-clamping technique for ATAAD was evaluated via the incidence of major adverse events including death, renal replacement therapy, stroke, and paraplegia, as well as times of circulatory arrest, cardiopulmonary bypass, and mechanical ventilation, and length of ICU stay.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

306

Conditions

Acute Type A Aortic Dissection Hypothermia Total Aortic Arch Replacement

Interventions

Arch-Clamping Technique under Mild HypothermiaPROCEDURE

This procedure is performed under mild hypothermia. The branch arteries of the arch are reconstructed using the side arms of a Y-shaped graft, which allows bilateral antegrade cerebral perfusion (bACP) through the right axillary artery. A FET is deployed in the descending aorta and clamped together with the autologous aorta immediately, then distal perfusion is restored through the femoral artery. After the proximal procedures are completed, the distal anastomosis is performed in an end-to-end fashion. Finally, the main trunk of the Y-shaped graft is anastomosed to the proximal grafts.

Arch-Clamping Technique under Moderate HypothermiaPROCEDURE

This procedure is performed under moderate hypothermia. The branch arteries of the arch are reconstructed using the side arms of a Y-shaped graft, which allow bACP through the right axillary artery. A FET is deployed in the descending aorta and clamped together with the autologous aorta immediately, then distal perfusion is restored through the femoral artery. After the proximal procedures are completed, the distal anastomosis is performed in an end-to-end fashion. Finally, the main trunk of the Y-shaped graft is anastomosed to the proximal grafts.

Total Arch Replacement combined Frozen Elephant Trunk Implantation using Bilateral Antegrade Cerebral Perfusion under Moderate Hypothermic Circulatory ArrestPROCEDURE

This procedure is performed using bACP under MHCA, which involves FET deployment in the descending aorta followed by total arch replacement with a four-branched vascular graft. Deployment of the FET and suture of the distal anastomosis are completed during bACP. MHCA is terminated and distal reperfusion is initiated once the distal anastomosis is completed, and the left carotid artery is reconstructed first (after which bACP is stopped, rewarming is started and the brain is perfused bilaterally). The root or valve procedures and some concomitant operations, if indicated, are performed during the cooling phase.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Aortic CTA confirmed as ATAAD according to the 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease; 2. Adult patients (18-70 years) weighing 50-120 kg; 3. Time interval between the onset of symptoms and operation is less than 14 days; 4. Indications for total aortic arch replacement are available; 5. Signed informed consent and availability for follow-up. Exclusion Criteria: 1. History of chronic renal failure, hepatocirrhosis, and hepatic insufficiency; 2. Severe gastrointestinal complications of non-aortic dissection, such as mesenteric ischemia, gastrointestinal bleeding, hepatopancreaticobiliary dysfunction, and intestinal obstruction; 3. History of severe cerebral infarction (with cerebral infarction sequels); 4. Preoperative intubation or unconsciousness; 5. Inflammatory aortic diseases, such as Takayasu arteritis and Behçet's disease, etc; 6. History of infectious aortic diseases; 7. History of cardiac and aortic surgery; 8. History of malignancy or previous radiotherapy; 9. Pregnant or feeding women, or anyone planning to reproduce during the test period; 10. Without an informed consent signature; 11. Participating in any other clinical trial; 12. Having other causes not eligible for operation.

Outcomes

Primary Outcomes

Major adverse events

Major adverse events include death, renal replacement therapy, stroke, and paraplegia

Time frame: Thirty days and 12 months after the operation

Secondary Outcomes

Circulatory arrest time

Time interval between ceasing and restarting cardiopulmonary bypass when core temperature reaches moderate hypothermia.

Time frame: During surgery

Cardiopulmonary bypass time

Start-to-end time of cardiopulmonary bypass to complete aortic repair.

Time frame: During surgery

Mechanical ventilation time

Time interval between mechanical ventilation and extubation after operation

Time frame: Discharge / 30 days after operation

The length of ICU stay

Time interval from ICU admission to transfer or death