Intraoperative identification of major blood supply to Adamkiewicz artery after multistep surgeries in thoraco-abdominal aortic aneurysm repair.

Herein, we report a case of thoraco-abdominal aortic repair in a 55-year-old man with a multiple treatment history for aortic aneurysm and aortic dissection. A computed tomography scan revealed that the Adamkiewicz artery was connected to an occluded intercostal artery, suggesting that the left inferior epigastric artery was the key artery supplying the Adamkiewicz artery; the key artery was identified through direct monitoring of cerebrospinal fluid temperature and selective hypothermic perfusion. No spinal cord injury was detected during the postoperative period.

Perioperative Hemodynamic Changes in the Thoracic Aorta in Patients With Aortic Valve Stenosis: A Prospective Serial 4D-Flow MRI Study.

This study investigated hemodynamic changes in the thoracic aorta and aortic arch branches before and after aortic valve replacement (AVR) by 4D-flow MRI in patients with aortic valve stenosis (AS). Thoracic 4D-flow MRI was performed in 10 AS patients before and after AVR (mean 27 ± 1.9 days). Fifteen aortic planes and 3 aortic arch branches planes were set to evaluate the mean volume flow rate in each plane during a cardiac cycle and the angle between the main flow direction in a specified plane and the axial direction of the aorta. We also focused on the distribution and magnitude of helicity density to evaluate the flow complexity. A significant increase in the volume flow rate after AVR was found in the ascending aorta (before 59.2 ± 8.7 mL/s vs after 77.3 ± 6.2 mL/s, P < 0.05) and the aortic arch branches (before 26.5 ± 2.8 mL/s vs after 35.8 ± 3.3 mL/s, P < 0.001). The flow angle significantly decreased in the ascending aorta (before 39.2 ± 2.7 degree vs after 25.2 ± 1.7°, P < 0.0001) and the arch aorta (before 19.3 ± 2.0 degree vs after 13.4 ± 0.9°, P < 0.001). The volume flow rate in the ascending aorta and the arch branches increased within 1 month after AVR, showing an increased blood supply to the upper body, including to the brain. The postoperative change was accompanied with an increased blood flow in the ascending aorta and a decreased flow complexity proximal to the arch branches.

Association between the severity of acquired von Willebrand syndrome and gastrointestinal bleeding after continuous-flow left ventricular assist device implantation.

OBJECTIVES: Acquired von Willebrand syndrome, characterized by the reduction in von Willebrand factor (vWF) large multimers, has recently been considered as one of the causes of gastrointestinal bleeding (GIB). It remains unclear whether its haematological severity is linked with susceptibility to bleeding because the definition of the haematological severity of acquired von Willebrand syndrome has not been precisely determined. This study sought to establish a quantitative methodology to assess the haematological severity of acquired von Willebrand syndrome and to define the threshold for occurrence of GIB in patients implanted with left ventricular assist devices (LVADs). METHODS: In total, 41 patients treated with continuous-flow LVAD implanted between 2011 and 2017 at Tohoku University Hospital were investigated. vWF large multimers were quantitatively evaluated using the 'vWF large multimer index' defined as the ratio of a large multimer proportion in total vWF derived from a patient to that from a normal control. Using this index, the amount of vWF large multimers was expressed as a percentage of its normal control value obtained with a simultaneous analysis of each time measurement. RESULTS: Twelve (29%) patients developed GIB events during follow-up periods (median 591 days) after an LVAD implantation. The vWF large multimer index in patients with GIB was significantly lower than that in those without GIB (25.0 ± 10.3% vs 37.5 ± 17.8%, P = 0.008). Most importantly, all patients experiencing GIB exhibited a vWF large multimer index below 40%. CONCLUSIONS: Patients with GIB exhibited a more severe loss of vWF large multimers. The vWF large multimer index may dictate the risk of GIB after an LVAD implantation. Clinical trial registration number: UMIN000018135.

Predictors of Heparin Resistance Before Cardiovascular Operations in Adults.

BACKGROUND: Heparin resistance (HR) is often encountered during cardiovascular operations that require cardiopulmonary bypass. Clinical risk factors and the mechanism underlying heparin resistance are yet to be determined. The aim of this study was to elucidate the clinically valid preoperative predictors related to HR. METHODS: The study evaluated 489 patients undergoing cardiovascular operations. Of these, 25 patients presented with HR and received antithrombin III for the initiation of cardiopulmonary bypass with an effective activated coagulation time. The remaining 464 patients, who did not receive antithrombin III, served as controls (NHR). Preoperative patient demographic and laboratory data were analyzed to identify risk factors for HR. RESULTS: The preoperative laboratory data showed platelet count, fibrinogen, D-dimer, creatinine, and C-reactive protein were significantly higher in the HR group than in the NHR group. As expected, the antithrombin III level was significantly lower overall in the HR group (86.0% vs 95.5%, p = 0.009); however, 80% of the patients in the HR group showed normal antithrombin III levels preoperatively. Multivariable logistic regression analysis identified chronic aortic dissection, chronic obstructive pulmonary disease, smoking, and elevated fibrinogen levels as independent predictors for HR. CONCLUSIONS: HR was shown to be associated with preoperative high fibrinogen levels, a smoking habit, and a preoperative diagnosis of chronic, but not acute, aortic dissection, with chronic obstructive pulmonary disease as comorbidity. Administration of antithrombin III resolved HR in all of the affected patients, even when their preoperative antithrombin III level was within the normal limit.

Oxygenation of the cerebrospinal fluid with artificial cerebrospinal fluid can ameliorate a spinal cord ischemic injury in a rabbit model.

OBJECTIVE: We evaluated the effect of cerebrospinal fluid oxygenation for the prevention of spinal cord ischemic injury after infrarenal aortic occlusion in a rabbit model. METHODS: Twenty white Japanese rabbits were categorized into the following 4 groups (5 in each): group S (sham), balloon catheter insertion on to the aorta; group C (control), spinal cord ischemic injury by infrarenal abdominal aortic balloon occlusion for 15 minutes; group N (nonoxygenated), spinal cord ischemic injury with cerebrospinal fluid replacement by nonoxygenated artificial cerebrospinal fluid; and group O (oxygenated), spinal cord ischemic injury with cerebrospinal fluid replacement by nanobubble-oxygenated artificial cerebrospinal fluid. The changes in cerebrospinal fluid partial pressure of oxygen during the peri-ischemic period, modified Tarlov score, and histopathology of the spinal cord 48 hours after aortic maneuvers were evaluated. RESULTS: Cerebrospinal fluid partial pressure of oxygen significantly increased in group O compared with group N after cerebrospinal fluid replacement (254.5 ± 54.8 mm Hg vs 136.1 ± 43.5 mm Hg, P = .02). After 15 minutes of spinal cord ischemic injury, cerebrospinal fluid partial pressure of oxygen in group C decreased to 65.8 ± 18.6 mm Hg compared with baseline (148.8 ± 20.6 mm Hg, P < .01), whereas cerebrospinal fluid partial pressure of oxygen in group O was maintained at remarkably high levels after spinal cord ischemic injury (291.9 ± 51.8 mm Hg), which was associated with improved neurologic function, with 20% of spinal cord ischemic injury having a Tarlov score less than 5 compared with 100% of spinal cord ischemic injury in group C. Preservation of anterior horn neurons in groups N and O was confirmed by histopathologic analysis with significant reduction of degenerated neurons compared with group C. CONCLUSIONS: Cerebrospinal fluid oxygenation with artificial cerebrospinal fluid can exert a protective effect against spinal cord ischemic injury in rabbits.

[Patient with massive hemothorax due to blunt trauma saved by transcatheter arterial embolization (TAE)].

A 78-year-old man who fell from a step ladder was transported to our hospital by ambulance under the diagnosis of multiple rib fractures and right hemothorax. Since he was in shock on arrival, endotracheal intubation and tube thoracotomy were immediately performed. Though 2 liters of blood was evacuated, persistent hemorrhage was observed, requiring continuous rapid infusion and blood transfusion. Emergency thoracic arteriography revealed active bleeding from a branch of the right internal thoracic artery. Transcatheter arterial embolization (TAE) was performed using vascular embolization coils and porous gelatin particles. These procedures successfully controlled active hemorrhage from the chest. Intrathoracic hematoma was evacuated through the 2nd large chest tube. Chest tubes were removed on the 7th day. He was discharged on the 17th day without any complications.