Acute Aortic Syndromes
Karim Ratib, Gurbir Bhatia, Neal Uren, James Nolan in Emergency Cardiology, 2010
The goal of surgery is to prevent progression of the dissection and to relieve obstruction in peripheral branches: thus, the intimal tear is excised and the origin of the false lumen excluded by proximal and distal suturing of the edges of the aorta. A prosthetic Dacron graft may be needed to approximate the ends of the aorta. Surgery requires a period of deep hypothermic circulatory arrest. Where the aortic valve is involved, the false channel is decompressed by the surgery described above, but may still require replacement or repair. Where the aorta is very friable, the whole ascending aorta and valve may be replaced using a composite graft containing a prosthesis with resuturing of the coronary arteries to the conduit. Preservation of the native aortic valve, which avoids the complications associated with a prosthetic valve, usually requires approximation of the two layers of dissected aortic wall and resuspension of the commissures with pledgeted sutures. However, prosthetic valve replacement is frequently advisable in the setting of pre-existent valve disease or in Marfan’s syndrome to reduce the likelihood of re-operation.
EEG Findings
Richard A. Jonas, Jane W. Newburger, Joseph J. Volpe, John W. Kirklin in Brain Injury and Pediatric Cardiac Surgery, 2019
During the continuous 48 postoperative hours of video-EEG monitoring there were a total of 16 patients who had EEG seizures without clinical accompaniment. Twelve of these patients were in the intact ventricular septum group, and nine were assigned to the circulatory arrest group. Eleven patients had both EEG and definite or suspected clinical seizures. Ten of the 11 patients in this group underwent deep hypothermic circulatory arrest, with only one undergoing low-flow bypass. Continuous EEG monitoring was able to identify ictal events before clinical signs were noted, with the ictal events on the EEG being detected from a few hours up to more than 20 hours before clinical seizures were noted. Since the physicians caring for these infants were blinded to the EEG findings, patients were treated with anticonvulsants (diazepam, lorazepam, midazolam, phenobarbitol) only after the onset of definite or possible clinical seizures, hours after the EEG seizures had begun.
Complications of open thoracoabdominal aortic aneurysm repair
Sachinder Singh Hans, Mark F. Conrad in Vascular and Endovascular Complications, 2021
Cryopreservation of cellular tissue has been employed for decades. Similarly, it has been shown that hypothermia can reduce metabolic rate and oxygen demand in nervous tissue.15 Based on this principle, in 2000, Cambria and Davison developed a method for regional spinal cord hypothermia with epidural cooling that was successful in 97% of patients in their series, with a spinal cord ischemia rate of 7% overall (type I/II 12%, all other types, 2.3%) in the setting of a clamp-and-sew technique with selective intercostal reimplantation.29 While we no longer employ this technique routinely, we do continue to use mild permissive corporeal hypothermia (32–34°C) during repair. Deep hypothermic circulatory arrest has been used to hypothetically decrease rates of paralysis, but this is typically only used in TAAA operations that involve the distal arch or to avoid cross clamping aorta affected by connective tissue disease.15
Hybrid Reconstruction of the Aortic Arch Using a Double-Branched Stent-Graft in a Canine Model
Published in Journal of Investigative Surgery, 2019
Fan Qiao, Cunhua Su, Qingqi Han, Mengwei Tan, Jun Wang, Yang Liu, Fanglin Lu, Lin Han, Zhiyun Xu
There were two reasons for the short HCA time. (1) The device was specifically designed to reduce the number of anastomoses in the aortic arch, and also the number of individual surgical steps. Deep hypothermic circulatory arrest (DHCA) was used solely to release the branched stent and for performing the vascular anastomosis. Release of the branched stent took around 5 min in the first five animals, and with experience the time decreased. (2) The aorta of the experimental dogs ordinarily had a diameter of approximately 20 mm, which is narrower than a human aorta, so the vascular anastomosis time was indeed shorter in the case of humans. For these reasons, the average DHCA time was 10 min. A somewhat longer time can be expected in humans; however, our experience suggests that this time can be limited to around 25 min in the case of human patients.
Total aortic arch replacement using the thoraflex hybrid prosthesis: early- and medium-term results from a Scandinavian center
Published in Scandinavian Cardiovascular Journal, 2021
Maria D. Soknes, Per S. Lingaas, Runar Lundblad, John-Peder Escobar Kvitting
In our data set, it was not possible to predict the outcome after the Thoraflex procedure. A meta-analysis by Tian et al. [13] identified cardiopulmonary bypass time, myocardial ischemia and circulatory arrest time to be associated with increased perioperative mortality. They reported a weighted average cardiopulmonary bypass time of 207 ± 63 min (in our cohort 200 ± 35 min), myocardial ischemia of 122 ± 45 min (in our cohort 113 ± 34 min), deep circulatory arrest time to the lower body of 48 ± 24 min (in our cohort 60 ± 22 min) and a SCAP time of 52 ± 31 min (in our cohort 67 ± 24 min). Our cohort had generally longer circulatory arrest and cerebral perfusion time than the data included in the meta-analysis by Tian, and two of our cases of in-hospital deaths had longer deep hypothermic circulatory arrest to the lower body (74 and 78 min) and SCAP time (78 and 78 min) than the weighted average reported by Tian et al. [13]. On the other hand, one of the deaths had a deep circulatory arrest to the lower body and SCAP time of 50 and 46 min, respectively. In our cohort, the number of adverse events such as death was too low to allow meaningful analysis of predictors of outcome.
Adenosine-induced transient asystole to control intraoperative rupture of intracranial aneurysms: institutional experience and systematic review of the literature
Published in British Journal of Neurosurgery, 2021
Eric S. Nussbaum, Elizabeth Burke, Leslie A. Nussbaum
There are limited reports in the literature where the indications for adenosine use involve controlling bleeding from intraoperative aneurysm rupture. Given these small sample sizes, results regarding rates of morbidity and mortality for adenosine-induced asystole cannot yet be generalized to a larger body of patients. Despite the limited patient populations and lack of guidelines reported in the literature, intraoperative adenosine use during the treatment of intracranial aneurysms has become generally accepted, and this agent appears to be a safe and useful option for patients with complex aneurysms. The minimal risks of side effects when given to appropriate patients makes adenosine considerably safer and less physiologically damaging than historical flow arrest techniques, such as deep-hypothermic circulatory arrest.16,36
Related Knowledge Centers
- Aortic Arch
- Arteriovenous Malformation
- Fibrillation
- Hypothermia
- Venae Cavae
- Atrial Septal Defect
- Cardiopulmonary Bypass
- Clinical Death
- Intracranial Aneurysm
- Pulmonary Thromboendarterectomy