Yusuke Inaba

Clinical Application of Intermittent Pressure-Augmented Retrograde Cerebral Perfusion

Brain protection is important during aortic arch surgery, especially in patients with cerebral ischemia. We clinically applied the effectiveness of a novel protocol of retrograde cerebral perfusion with intermittent pressure augmentation for brain protection in a canine model, as described in a previous report. Although, in our patient the brachiocephalic artery and left subclavian artery were occluded as a result of aortitis, there was a history of right cerebral infarction, recovery of consciousness, and no neurologic sequelae. Near-infrared oximetry showed recovery of intracranial blood oxygen saturation every time the pressure was augmented.

Clinical efficacy of intermittent pressure augmented–retrograde cerebral perfusion

OBJECTIVE During aortic surgery under hypothermic circulatory arrest, retrograde cerebral perfusion (RCP) is commonly used as a cerebroprotective method to extend the duration of circulatory arrest safely. Kitahori and colleagues described a novel protocol of RCP using intermittent pressure augmented (IPA)-RCP in 2005. The aim of the present study was to determine the clinical effectiveness of this novel protocol. METHODS A total of 20 consecutive patients undergoing total replacement of the aortic arch were assigned to a conventional RCP (n = 10) or an IPA-RCP group (n = 10). Cerebral perfusion was provided at a continuous venous pressure of 25 mm Hg in the conventional RCP, and venous pressure was intermittently provided at 20 mm Hg for 120 seconds and at 45 mm Hg for 30 seconds in the IPA-RCP group. The clinical outcomes were compared between the 2 groups. Regional cerebral oxygen saturation (rSO(2)) was measured using near infrared spectroscopy every 10 minutes from the beginning of RCP initiation. To represent the brain oxygen consumption, the decline ratio of rSO(2) was calculated. RESULTS There was no surgical mortality or major neurologic complications in either group. The interval from the end of surgery to full wakefulness was significantly shorter in the IPA-RCP group (85 ± 64 minutes) than in the conventional RCP group (310 ± 282 minutes; P < .05). Although the initial rSO(2) value did not show significant difference in both groups, the rSO(2) with IPA-RCP was greater than that with conventional RCP from 10 to 70 minutes (P < .05). The decline ratio of rSO(2) was lower in the IPA-RCP group than in the RCP perfusion group at all points (P < .05). CONCLUSIONS IPA-RCP might provide more homogenous cerebral perfusion and a more effective oxygen supply to the brain with better clinical results than conventional RCP.

Equine pericardial roll graft replacement of infected pseudoaneurysm of the aortic arch

Resection of the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy is the standard procedure for treating infected aortic aneurysms, but the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected thoracic aortic aneurysm. The aneurysm was located in the proximal aortic arch. Because the patients had previously undergone abdominal surgery, the aortic arch were replaced in situ with a branched equine pericardial roll grafts. The patient is alive and well 23 months after the operation.

Patency of Saphenous Vein Grafts Using the PAS-Port System During Coronary Artery Bypass Surgery

BACKGROUND Several proximal anastomosis devices have been developed to shorten the time required for a proximal anastomosis and to avoid aortic cross-/side-clamping during coronary artery bypass grafting. This study retrospectively examined the patency of saphenous vein grafts (SVGs) using the PAS-Port System (Cardia Inc, Redwood City, CA). METHODS From 2004 to 2014, 451 patients underwent coronary artery bypass graft operations requiring at least 1 proximal anastomosis using a PAS-Port device. A total of 802 PAS-Port devices were used, and 95.0% (762 of 802) were implanted successfully. Among the successfully implanted anastomoses, 76.8% (585 of 762) were evaluated using coronary angiography or multidimensional computed tomography, or both. The evaluations were performed between postoperative days 4 and 3,182 (mean, 319 ± 624 days). The early (1 to 365 days) and the midterm to long-term (more than 366 days) occlusion rates were examined. A complete postoperative clinical course was recorded for 70.7% of the patients. RESULTS Overall, 93.8% (549 of 585) of the device-dependent SVGs were patent. The patency rates of device-dependent SVGs that were 1, 2, 3, 4, 5, 6, 7, and 8 years old were 90.1% ± 1.8%, 87.1% ± 2.3%, 86.1% ± 2.5%, 82.9% ± 3.3%, 80.6% ± 3.9%, 77.2% ± 5.0%, 77.2% ± 5.0%, and 70.2% ± 8.1%, respectively. The longest follow-up period was 3,182 days (8.7 years). The occlusion rate for device-dependent SVGs tended to decrease as the number of patients accumulated. CONCLUSIONS The PAS-Port system provided acceptable SVG patency and clinical outcome for the early and midterm to long-term. There may be a learning curve for the use of PAS-Port device that affects the device-dependent SVG patency.

Observations of retinal vessels during intermittent pressure-augmented retrograde cerebral perfusion in clinical cases

OBJECTIVES Retrograde cerebral perfusion (RCP) has been used as a cerebroprotective method under hypothermic circulatory arrest (HCA) during aortic surgery. As reported in an animal model in 2005, intermittent pressure-augmented-RCP (IPA-RCP) provides more effective cerebral perfusion than RCP. In 2013, the clinical efficacy of IPA-RCP was described in terms of clinical outcomes and regional cerebral oxygen saturation using infrared spectroscopy. However, the state of cerebral microcirculation during IPA-RCP has not been investigated in humans. The aim of the present study was to investigate cerebral microcirculation during IPA-RCP in humans by assessing the retinal vessels. METHODS Between 2013 and 2014, 8 consecutive patients underwent elective total replacement of the aortic arch for true thoracic aortic aneurysms. The IPA-RCP protocol consisted of a continuous venous pressure that was intermittently augmented at 45 mmHg for 30 s and then decreased to 20 mmHg for 120 s after isolated HCA for 300 s. The retinal vessels were assessed via non-invasive direct visualization of the cerebral microcirculation using a fundus camera. Assessments were done before cardiopulmonary bypass, during isolated HCA, and during IPA-RCP at 20 and 45 mmHg. Ratio of the diameter of retinal vessels to that of the optic disc was calculated from the diameters of the retinal arteries, veins and optic disc at each time point and was statistically examined. RESULTS There were no neurological deficits and mortality. When compared with the control group and both IPA-RCP groups, the retinal vessels in the isolated HCA group were collapsed and the peripheral retinal vessels could not be clearly observed. The RVR was significantly larger in the control group and in both IPA-RCP groups when compared with the isolated HCA group. The RVR of the control group was similar to that of both IPA-RCP groups with regard to the retinal arteries and veins. The RVR of IPA-RCP at 45 mmHg was significantly larger than that at 20 mmHg with regard to the retinal veins. CONCLUSIONS Our study suggested that intermittently augmented venous pressure at 45 mmHg opened the cerebrovenous vessels and enabled adequate cerebral perfusion. IPA-RCP may provide more effective cerebral perfusion under HCA in humans.

Airway obstruction by a retropharyngeal hematoma secondary to thoracic aortic aneurysm rupture

BackgroundRetropharyngeal hematoma is a rare form of pharyngeal pathology and can present as acute airway obstruction. Among the many causes of retropharyngeal hematoma, thoracic aortic rupture is extremely rare.Methods and resultsA 78-year-old female with airway obstruction by a retropharyngeal hematoma secondary to thoracic aortic aneurysm rupture was successfully treated by total aortic arch replacement and open stent-graft insertion.ConclusionRupture of the thoracic aorta should be considered as a rare but important cause of retropharyngeal hematoma and airway obstruction.

Equine pericardial roll graft replacement of infected pseudoaneurysm of the ascending aorta

The standard procedure for treating infected aortic aneurysms is to resect the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy. However, the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected ascending aortic aneurysm. Because of previous abdominal surgery, the omentum was unavailable. The ascending aorta was replaced in situ with equine pericardial roll grafts. The patient is alive and well 29 months after the operation.

Total aortic arch replacement with patent left internal thoracic artery graft after previous coronary artery bypass graft surgery

A 78-year-old man, who had previously undergone coronary artery bypass graft surgery, was admitted to our department for treatment of a distal aortic arch aneurysm. A total aortic arch replacement with a patent left internal thoracic artery (LITA) graft was successfully performed without cardiac ischemic or neurological complications. Use of retrograde cardioplegia with intermittent pressure-augmented retrograde cerebral perfusion without clamping and dissecting the LITA graft were effective in myocardial and cerebral protection.

Off-pump hemostasis for left ventricular rupture after myocardial infarction with Hydrofit® and Surgicel®

Left ventricular free wall rupture (LVFWR) is a catastrophic complication of myocardial infarction. In these cases, cardiopulmonary bypass (CPB) should be performed for left ventricular repair, but can impact hemodynamic stability. An 87-year-old man presented with acute shock. He was diagnosed with LVFWR after myocardial infarction. We describe a simple, effective, and reproducible technique to achieve hemostasis at the LVFWR site during emergency operation using Hydrofit® and Surgicel® surgical hemostatic agents. We simply placed and manually pressed the Hydrofit® and Surgicel® composite on the bleeding site. This technique provides complete hemostasis without CPB establishment.

Two adult cases of Bland–White–Garland syndrome with lethal arrhythmia due to coronary steal phenomenon during physical or mental stress

We experienced two adult cases of anomalous origin of the left coronary artery from the pulmonary artery, so-called Bland-White-Garland (BWG) syndrome, that presented with ventricular tachycardia (VT) and ventricular fibrillation during exertion in daily life. They presented to our hospital with syncope due to VT, and recovered following application of an automated external defibrillator with cardiopulmonary resuscitation. We diagnosed BWG syndrome by multi-detector computed tomography angiography and coronary angiography. We analyzed the mechanisms of lethal arrhythmias in relation to myocardial ischemia on exertion. Coronary flow modification and implantable cardioverter defibrillator implantation were performed in order to prevent future lethal arrhythmia due to myocardial ischemia. It is important to be aware of congenital heart disease in ordinary cases. <Learning objective: We experienced two rare cases of patients who were admitted with ventricular tachycardia and ventricular fibrillation who had adult type Bland-White-Garland syndrome during exertion in daily life. It is important to be aware of congenital heart disease in ordinary cases.>.