Authors (including presenting author) :
Tsang KM(1), Yung EP(1)
Affiliation :
(1) Perfusion Team, Department of Surgery, Prince of Wales Hospital
Introduction :
Open repair of thoracoabdominal aortic aneurysm (TAAA) traditionally poses significant risk of perioperative morbidity and mortality.
Although endovascular treatment options with fenestrated and branched endovascular repair is already routinely used for TAAA treatment in dedicated centers, open aortic repair remains the standard of care in many centers.
Since 2020, the Prince of Wales Hospital has advanced using open surgical repairing as one of the treatment considerations. 24 out of 66 patients had undergone resection and graft replacement of the diseased aortic segments using selective hypothermic (25-33 °C) cardiopulmonary bypass (CPB) with or without circulatory arrest, including 14 elective and 10 emergency rupture cases.
Open repair is the gold standard for TAAA treatment. The Prince of Wales Hospital (PWH) is one of the cardiac center offered open surgical repair of TAAA.
The aim of this study was to clarify if selective perfusion has such an effect and to review the clinical outcomes in patients have undergone the open surgical treatment of TAAA.
Objectives :
1. To review the ongoing experience with open repair of complex thoracoabdominal aneurysms.
2. To evaluate our experience with thoracoabdominal aortic aneurysm repair using selective hypothermic CPB with or without circulatory arrest.
3. To assess the effectiveness and clinical use of selective hypothermic CPB with or without circulatory arrest during open thoracoabdominal aortic surgery.
Methodology :
Between January 2020 and September 2022, 24 patients with descending thoracic and thoracoabdominal aneurysms were operated. Despite a standard femoral-femoral cardiopulmonary bypass with circulatory arrest is established, the circuit is completed by a bifurcated system at the arterial perfusion side. The bifurcated approach has emerged to maintain distal aortic perfusion and provide selective visceral perfusion.
Once the proximal anastomosis is completed and tested, arterial perfusion to the upper body is reestablished by using one of the bifurcated systems to perfuse independently. The flow rate is kept between 1-1.5 L per minute to keep the mean arterial pressure (MAP) at 55 mmHg or above. The cardiopulmonary bypass will be terminated when all the anastomoses are completed.
Selective hypothermic CPB eliminates the need for proximal and sequential clamping as well as extensive mobilization of the aorta. Most of the shed blood is returned to the perfusion circuit. The hypothermia helps increase ischemic tolerance and allows unhurried aortic reconstruction.
Result & Outcome :
During the period of January 2020 and September 2022, 11 patients were put on partial hypothermic cardiopulmonary bypass without circulatory arrest and the other 13 patients required circulatory arrest. The mean duration of cardiopulmonary bypass and hypothermic circulatory arrest was 242.7 +/-78.9 mins and 58.8 +/- 24.9 mins.
Among these 24 patients, only 4 patients required renal perfusion (31-162 mins), 3 patients would need visceral perfusion (131-250 mins).
The ICU-stay for these patients is 1-32 days. The 7-day mortality rate was 12.5% (3 patients, 2 of them died of pneumonia on day 6). The 30-day mortality rate was 0% (0 patient). 2 patients had died within 1 year after the operation.
The selective hypothermic cardiopulmonary bypass with intervals of circulatory arrest is a safe and effective method for repair of thoracoabdominal aortic aneurysms. This technique provides a bloodless field and access to the aortic arch.
The selective hypothermic cardiopulmonary bypass procedure with or without circulatory arrest has been successfully used for the treatment of complex disease that involves the descending thoracic and thoracoabdominal aorta in the PWH.
