thiopental and Aortic-Aneurysm--Thoracic

We have surgically treated 771 patients for thoracic and thoracoabdominal aortic aneurysms since 1983. Our primary effort has been to develop experimentally validated strategies to reduce paraplegia, renal failure, and mortality in these high-risk patients. This approach has led to a spinal cord protection protocol that has reduced paraplegia risk by 80% (observed/expected ratio = 0.19) with the use of cerebral spinal fluid drainage, moderate hypothermia (31°C-33°C), endorphin receptor antagonist (naloxone), and thiopental burst suppression while optimizing mean arterial pressure (> 90 mm Hg) and cardiac index. The elective mortality rate is 2.80% (17% for acute patients), and with rapid renal cooling for renal protection, only 0.88% required permanent dialysis. These results were achieved without the use of assisted circulation. We have reattached intercostal arteries since 2005 using preoperative magnetic resonance angiographic localization, but it remains unclear whether intercostal reimplantation reduces paraplegia risk, as we had initially proposed. We strongly believe that a consistent anesthetic and postoperative care protocol uniformly built and applied around these principles greatly enhances our surgical outcomes. We also show that improved outcomes with assisted circulation and hypothermic arrest in treatment of thoracoabdominal aortic disease follow similar principles of spinal cord and end-organ protection.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anesthetics, Intravenous; Aortic Aneurysm, Thoracic; Assisted Circulation; Cerebrospinal Fluid Shunts; Child; Constriction; Female; Heart Arrest, Induced; Hemodynamics; Humans; Hypothermia, Induced; Male; Middle Aged; Naloxone; Narcotic Antagonists; Paraplegia; Postoperative Care; Renal Insufficiency; Replantation; Risk Assessment; Risk Factors; Spinal Cord Ischemia; Suture Techniques; Thiopental; Thoracic Arteries; Treatment Outcome; Vascular Surgical Procedures; Wisconsin; Young Adult

Hypothermic circulatory arrest is a standard procedure for the treatment of aortic arch. However, there is a time limit for this procedure. There is now an urgent need to develop prophylactic measures to extend the time limit. We have used a pharmacological mixture of thiopental, nicardipine and mannitol for all patients undergoing circulatory arrest since 1991 to extend the safe limit. The purpose of this study was to analyze the neurological complications demonstrated by these patients and to evaluate the brain-protective effects of our measure.. The clinical records of 75 consecutive patients undergoing an aortic arch repair using a hypothermic circulatory arrest technique during the past 8 years were retrospectively reviewed. Systemic cooling was continued until a total disappearance of EEG activity. Prior to circulatory arrest, 15 or 30 mg/kg of thiopental, 20 mg of nicardipine and 300 ml of mannitol were infused into the venous reservoir of a cardiopulmonary bypass circuit. Graft replacement was performed in all patients and the extent of replacement was a total aortic arch in 43 patients, a distal aortic arch in 17, a hemiarch in 13 and a distal aortic arch and a total descending aorta in two.. The duration of circulatory arrest ranged from 16 to 80 min (mean 41.5 min), and it exceeded 45 min in 37 patients. Operative mortality was 10.7% and two patients died of stroke. Three patients had permanent and three other patients had transient neural deficits. The incidence of stroke was 8.0% as a whole, and no correlation between the incidence of neurological complications and the duration of circulatory arrest was found. A multivariate analysis showed that the duration of circulatory arrest was determined as a predictor of neither operative mortality nor postoperative stroke.. The findings of the present study suggest that our pharmacological brain protection appears to be effective for safely extending hypothermic circulatory arrest.

Topics: Adult; Aged; Aged, 80 and over; Aortic Aneurysm, Thoracic; Aortic Dissection; Aortic Rupture; Blood Vessel Prosthesis Implantation; Brain Injuries; Cardiopulmonary Bypass; Cause of Death; Diuretics, Osmotic; Drug Therapy, Combination; Electroencephalography; Humans; Hypnotics and Sedatives; Hypothermia, Induced; Mannitol; Middle Aged; Monitoring, Intraoperative; Nicardipine; Retrospective Studies; Thiopental; Time Factors; Treatment Outcome; Vasodilator Agents

One of the most important disadvantages of the hypothermic circulatory arrest technique is the limited time allowable for circulatory arrest. Thiopental is usually used to protect the brain against ischemic injuries. However, it remains uncertain how well thiopental reduces cerebral metabolism. We investigated its effectiveness by comparing outcomes after different doses.. Fifty patients who underwent aortic arch repair with hypothermic circulatory arrest had their records reviewed. Electroencephalograms (EEG) and partial pressures of oxygen in the internal jugular vein (PjO2) were monitored. Following confirmation of total disappearance of EEG activity, 15 or 30 mg/kg thiopental was administered before circulatory arrest Th duration of circulatory arrest ranged from 16 to 77 min.. Hospital mortality rate was 10% and 4 (8%) patients developed neu-rologic complications, but 3 of them were transient. After thiopental infusion, PjO2 increased significantly from 430 to 499mmHg (p <0.01), indicating that thiopental reduces cerebral oxygen consumption. The rate of the decrease in PjO2 during circulatory arrest was slower with the higher thiopental dose, suggesting that thiopental lowered the cerebral metabolic rate of oxygen during circulatory arrest.. It appears that thiopental has protective effects against cerebral ischemia under profound hypothermia.

Topics: Adult; Aged; Aged, 80 and over; Aortic Aneurysm, Thoracic; Brain; Brain Ischemia; Female; Heart Arrest, Induced; Humans; Hypothermia, Induced; Male; Middle Aged; Oxygen Consumption; Thiopental; Treatment Outcome

From 1992 to July 1996, 19 patients (aged 39 to 78 years) were operated on for type A acute aortic dissection. Our operative strategy is that all patients in whom aortic dissection involves the segment of transverse aortic arch should undergo simultaneous replacement or repair of the aortic arch and ascending aorta. Among these 19 patients, 17 were operated on within 24 hours after onset. In 13 patients, graft replacement extended from the ascending aorta to the transverse portion of the arch. The aortic stumps were prepared with the Teflon left both inside and outside of the aortic wall. Recently these were reconstructed with the aid of the Gelatin-Resorcin-Formaling glue, instilled into the false lumen. Cerebral protection was achieved by hypothermic circulatory arrest associated with the cerebroplegia (thiopental, nicradipine and mannitol). In one patient associated with severe aortic regurgitation, a valved conduit was implanted and the coronary arteries were reimplanted. CABG was performed concomitantly in two patients for involvement of the proximal coronary arteries by the dissection process. The hospital mortality rate was 26% (5/19). However, in two of them, death was not directly related to the operative procedure. One patient died of graft versus host disease (GVHD), another patient died of acute epidural hemorrhage which was undetected until the repair was completed. During the postoperative course, in all but two patients, the false lumens of the aortic arch and/or descending thoracic aorta were confirmed to be totally thrombosed by the examination of CT scan and/or aortography. It is concluded that the surgical treatment of type A acute aortic dissection can be successfully performed, even if the graft replacement extended to the transverse aortic arch.

Topics: Acute Disease; Adult; Aged; Aortic Aneurysm, Thoracic; Aortic Dissection; Blood Vessel Prosthesis; Cerebrovascular Circulation; Female; Heart Arrest, Induced; Humans; Hypothermia, Induced; Male; Mannitol; Middle Aged; Nicardipine; Perfusion; Potassium Compounds; Thiopental