Publications by authors named "Atsuo Mori"

24 Publications

  • Page 1 of 1

Coronary Artery Fistula Aneurysm: Pathological Analysis After Surgery.

Cureus 2021 May 8;13(5):e14903. Epub 2021 May 8.

Cardiology, Kawasaki Municipal Ida Hospital, Kawasaki, JPN.

An asymptomatic 75-year-old woman was identified with a 40-mm-sized, round-shaped lesion beside the pulmonary artery on computed tomography (CT). Coronary angiography showed a coronary artery fistula (CAF) with an aneurysm branching from the left anterior descending artery toward the pulmonary artery. The CAF aneurysm (CAFA) was resected and coronary artery bypass graft surgery using the left internal thoracic artery was performed successfully. Pathological analysis revealed that medial depletion similar to segmental arterial mediolysis (SAM) may contribute to aneurysm formation.
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http://dx.doi.org/10.7759/cureus.14903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8183465PMC
May 2021

Giant Aneurysm of Coronary Artery Fistula Successfully Treated by Surgical Repair.

Cureus 2020 Mar 27;12(3):e7430. Epub 2020 Mar 27.

Cardiology, Kawasaki Municipal Ida Hospital, Kawasaki, JPN.

An asymptomatic 65-year-old woman was identified with an oversized round-shaped hypoechoic lesion (62 mm in diameter) between right and left atria by echocardiogram. A contrast-enhanced 320-slice multidetector computed tomography demonstrated a giant aneurysmatic fistula branched from the left main coronary trunk towards right atrium. The patient underwent an elective surgical repair. The aneurysm was resected, followed by coronary artery bypass graft surgery using bilateral internal thoracic arteries. The surgery was successful, and the patient enjoys normal life without any symptoms for 15 months.
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http://dx.doi.org/10.7759/cureus.7430DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7186111PMC
March 2020

Emergency Endografting for Spontaneous Thoracic Aortic Rupture.

Ann Thorac Cardiovasc Surg 2021 Feb 12;27(1):68-70. Epub 2018 Jun 12.

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan.

Spontaneous rupture of the thoracic aorta is rare. We present a 76-year-old man who developed spontaneous rupture of the aortic arch associated with massive periaortic hematoma and hypovolemic shock. Because the site of rupture could not be identified, emergency hybrid endovascular aortic repair to shield a long segment of the aorta was performed according to the extent and density of periaortic hematoma on axial CT scans. His blood pressure improved just after deployment of the endograft. Rapid diagnosis by CT and prompt control of aortic hemorrhage by endografting salvaged this patient. Three-dimensional (3D) volume-rendered CT images are useful for identifying the site of aortic rupture, but may not be available in an emergency.
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http://dx.doi.org/10.5761/atcs.cr.18-00020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8043022PMC
February 2021

Mediastinal schwannoma diagnosed preoperatively as a cyst.

Tex Heart Inst J 2014 Feb;41(1):76-9

Departments of Cardiovascular Surgery (Drs. Mori, Suzuki, and Taguchi), Radiology (Drs. Hasegawa and Sato), and Pathology (Drs. Irie and Sugiura), Kawasaki Municipal Hospital, Kawasaki, Kanagawa 210-0013, Japan.

Mediastinal schwannomas are sometimes diagnosed as pericardial or bronchogenic cysts, if cystic degeneration is extensive. When mediastinal schwannomas are not diagnosed as primary cardiac tumors, the use of cardiopulmonary bypass in their resection appears to be infrequent. We report the case of a 48-year-old woman who presented with symptoms from a suspected intrapericardial cyst. Multiple diagnostic images revealed a large mass, potentially a proteinaceous or hemorrhagic cyst, in the transverse sinus behind the ascending aorta and against the left main trunk. After complete resection with the use of cardiopulmonary bypass, the mass was identified as a benign extracardiac schwannoma. More than 3 years postoperatively, the patient had no relevant symptoms. We discuss the preoperative diagnosis, the method of resection, and our broad strategy for dealing with such a case.
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http://dx.doi.org/10.14503/THIJ-12-2760DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3967471PMC
February 2014

Thoracic and thoracoabdominal aortic repair under regional spinal cord hypothermia.

Eur J Cardiothorac Surg 2014 Jul 12;46(1):40-3. Epub 2013 Dec 12.

Department of Cardiovascular Surgery, Keio University, Tokyo, Japan.

Objectives: Spinal cord deficits are devastating complications after surgery for thoracic and thoracoabdominal aortic aneurysms. We developed a regional spinal cord cooling system using an epidural catheter containing cold saline within an isolated counter-current lumen to prevent such complications and reviewed the clinical results.

Methods: We enrolled 37 patients with thoracic (n = 13) and thoracoabdominal (n = 24) aortic aneurysms that were repaired using the regional spinal cord cooling system under mild hypothermia with a partial femoro-femoral bypass.

Results: Although 2 patients died before hospital discharge (hospital mortality, 5.4%), none developed neurological deficits such as paraplegia or paraparesis.

Conclusions: The outcomes of surgery for thoracic and thoracoabdominal aortic aneurysms under regional spinal cord hypothermia using a custom-designed epidural catheter were excellent. Although our patient cohort was small, the results indicate that our technique might help to improve the outcomes of thoracic and thoracoabdominal aortic repair.
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http://dx.doi.org/10.1093/ejcts/ezt574DOI Listing
July 2014

Aortic valve repair with autologous pericardium for traumatic aortic valve regurgitation.

Cardiovasc Diagn Ther 2013 Sep;3(3):180-2

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan;

We present a case of successful aortic valve repair for traumatic aortic valve regurgitation. A 26-year-old male who had a history of motor-cycle accident months prior to admission, was referred to our hospital for surgical treatment of severe aortic valve regurgitation. Intraoperative inspection revealed a tear in noncoronary cusp, with otherwise preserved valvular anatomy. Aortic valvuloplasty was successfully performed with closure using an autologous pericardium patch. Intraoperative transesophageal echocardiogram confirmed absence of residual regurgitation.
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http://dx.doi.org/10.3978/j.issn.2223-3652.2013.05.03DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839205PMC
September 2013

Technique for using pedicled latissimus dorsi muscle flaps to wrap prosthetic grafts in an infected thoracic aorta.

Ann Vasc Surg 2013 Nov 5;27(8):1223-7. Epub 2013 Sep 5.

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan. Electronic address:

In this report we describe a special method of using a pedicled latissimus dorsi muscle flap for a mycotic aneurysm. The method involves wrapping the flap around a prosthetic graft. Using this method, an in situ graft, which replaces an aneurysm, can help to avoid recurrence of local infection.
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http://dx.doi.org/10.1016/j.avsg.2013.04.009DOI Listing
November 2013

Simplicity, skills, and pitfalls of ascending aortic cannulation for type A aortic dissection.

J Cardiothorac Surg 2013 Jun 26;8:161. Epub 2013 Jun 26.

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, 12-1 Shinkawadori, Kawasaki-ku, Kawasaki-city, Kanagawa 210-0013, Japan.

Background: Ascending aortic cannulation for an antegrade central perfusion during surgery for type A aortic dissection is simple and can be performed within median sternotomy. This cannulation is performed routinely without problems in our hospital. Using our experience, the skills and pitfalls were clarified to make this challenging procedure successful.

Methods: 29 cases of ascending aortic cannulation using the Seldinger technique for insertion were studied. All insertions were performed with the guidance of transesophageal echocardiography alone. The cannulas were inserted after decompressing the aorta by initiating cardiopulmonary bypass with femoral artery cannulation. From our experience, the skills required for this procedure are the abilities to carefully assess the needle insertion site preoperatively, sense resistance to needle insertion twice, and ensure the guide wire is in the descending aorta and distal arch. The pitfalls are entrance of the guide wire into the false lumen and dilatation of the false lumen during the insertion procedure.

Results: There were no complications associated with ascending aortic cannulation. Regarding morbidity, 2 cases of brain infarction occurred. There were 3 hospital deaths unrelated to the procedure.

Conclusions: In surgery for type A aortic dissection, ascending aortic cannulation using the Seldinger technique is simple to perform. We found that some practical skills and precautions were required to make this procedure successful.
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http://dx.doi.org/10.1186/1749-8090-8-161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699433PMC
June 2013

Intravenous Lobular Capillary Hemangioma Occurring after Needle Insertion during Routine Health Checkup.

Ann Vasc Dis 2013 28;6(1):102-5. Epub 2013 Feb 28.

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan.

Surgery was performed on a 53-year-old male patient with a painful mass in front of the elbow. The mass originally occurred after needle insertion during a routine health checkup and grew in size during a 1-year period. Intravenous tumor with arterio-venous fistula was diagnosed, and it was resected. Histopathological diagnosis of intravenous lobular capillary hemangioma was made. Occurrence of this tumor after a routine health checkup is rare. The etiology of this tumor occurring simultaneously with arteriovenous fistula is discussed.
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http://dx.doi.org/10.3400/avd.cr.12.00089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3635011PMC
May 2013

Resection of an intrapericardial lipoma with nonsustained ventricular tachycardia.

J Card Surg 2013 May 28;28(3):268-70. Epub 2013 Mar 28.

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan.

A 35-year-old female presented with nonsustained ventricular tachycardia (NSVT) and a large intrapericardial mass. The mass was attached to the left ventricular wall with a broad stalk. On histopathology, the tumor was diagnosed as a lipoma. Postoperatively, the NSVT disappeared.
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http://dx.doi.org/10.1111/jocs.12095DOI Listing
May 2013

Malignant solitary fibrous tumor of the left ventricular epicardium.

Ann Thorac Surg 2013 Apr;95(4):1447-50

Department of Cardiovascular Surgery, Kawasaki Municipal Hospital, Kanagawa, Japan.

Reports describing solitary fibrous tumors of the pericardium are rare. Surgical treatment was performed on a 49-year-old woman with a large pericardial mass. The mass was attached to the left ventricular wall with a broad stalk and was free of the parietal pericardium. It was apparent macroscopically that the tumor had invaded the left ventricular muscle. On histopathology, the tumor was diagnosed as a solitary fibrous tumor with low-grade malignancy.
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http://dx.doi.org/10.1016/j.athoracsur.2012.08.033DOI Listing
April 2013

Combined use of an epidural cooling catheter and systemic moderate hypothermia enhances spinal cord protection against ischemic injury in rabbits.

J Thorac Cardiovasc Surg 2013 Sep 13;146(3):696-701. Epub 2012 Dec 13.

Department of Cardiovascular Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan.

Background: Epidural placement of a cooling catheter can protect against ischemic spinal cord injury. With the use of rabbits, we investigated whether this epidural cooling technique, when combined with systemic moderate hypothermia, can protect the spinal cord against ischemic metabolic stress.

Methods: New Zealand white rabbits (n = 28) were assigned to 1 of 4 different groups. Animals underwent abdominal aortic occlusion for 30 minutes using a 3F balloon catheter. Group 1 (n = 7) underwent epidural cooling by the catheter and systemic moderate hypothermia (35 °C) induced with a cooling blanket. Group 2 (n = 7) underwent epidural cooling under systemic normothermia (38.5 °C). Group 3 (n = 7) underwent systemic moderate hypothermia (35 °C) without epidural cooling. Group 4 (n = 7) underwent neither epidural nor blanket cooling as a negative control. Neurologic status of their hind limbs was graded according to the modified Tarlov scale at 1, 2, and 7 days after surgery.

Results: During infrarenal aortic ischemia, epidural temperature was significantly lower in group 1 (18.5 °C ± 0.8 °C) than in group 2 (28.6 °C ± 1.0 °C; P = .0001), group 3 (34.2 °C ± 0.06 °C; P = .0001), or group 4 (38.5 °C ± 0.2 °C; P = .0001). Hind limb function recovery was greater in group 1 (mean Tarlov score, 4.9 ± 0.057) than in group 2 (2.6 ± 0.3; P = .0028), group 3 (2.1 ± 0.34; P = .0088), or group 4 (0.0 ± 0.0; P = .0003).

Conclusions: Epidural cooling catheter combined with systemic moderate hypothermia produced additive cooling ability and protected the spinal cord against ischemia in rabbits more effectively than either intervention alone.
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http://dx.doi.org/10.1016/j.jtcvs.2012.11.040DOI Listing
September 2013

Regional spinal cord cooling using a countercurrent closed-lumen epidural catheter.

Ann Thorac Surg 2010 Apr;89(4):1312-3

Department of Cardiovascular Surgery, Keio University, Shinjuku-ku, Tokyo, Japan.

We developed a method of regional spinal cord cooling by using an epidural catheter containing cold saline in its isolated counter-current lumen. We describe the clinical application of this innovative procedure to the prevention of paraplegia during surgery for thoracic and thoracoabdominal aortic aneurysms.
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http://dx.doi.org/10.1016/j.athoracsur.2009.06.045DOI Listing
April 2010

Epidural cooling minimizes spinal cord injury after aortic cross-clamping through induction of nitric oxide synthase.

Anesthesiology 2009 Oct;111(4):818-25

Department of Anesthesiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.

Background: By using a U-shaped lumen catheter, the authors examined the effects of epidural cooling on spinal cord injury after aortic cross-clamping (ACC), with a focus on changes of spinal cord blood flow and expression of inducible nitric oxide synthase.

Methods: Sixteen pigs were randomized into two groups: Control group (n = 8) or Cooling group (n = 8). In the latter, epidural cooling started at 30 min (baseline) before 45 min of ACC and persisted for the next 30 min of reperfusion period. Spinal cord blood flow and somatosensory-evoked potentials were assessed during peri-ACC period. At 48 h, we evaluated hind limb function by using Tarlov score and expression of inducible nitric oxide synthase on spinal cord using immunohistochemistry.

Results: After ACC, spinal cord blood flow dropped to a similar extent in both groups. During the reperfusion period, spinal cord blood flow increased up to 113% (103-124%), median (interquartile range), level transiently and decreased to 32% (22-47%) level versus baseline in the Control group, whereas it increased and remained at 92% (86-97%) level in the Cooling group. Simultaneously, somatosensory-evoked potentials showed that onset of loss time was delayed and recovery time was shortened in the Cooling group. Tarlov scores in the Cooling group were significantly higher and accompanied by normal-appearing motor neurons and significantly greater expression of inducible nitric oxide synthase on spinal cord versus the Control group.

Conclusions: This study shows that epidural cooling during ACC minimized the risk of spinal cord injury, possibly by preventing delayed hypoperfusion and upregulating inducible nitric oxide synthase expression.
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http://dx.doi.org/10.1097/ALN.0b013e3181b764f6DOI Listing
October 2009

Formation of prebeta1-HDL during lipolysis of triglyceride-rich lipoprotein.

Biochem Biophys Res Commun 2009 Jan 12;379(1):55-9. Epub 2008 Dec 12.

Tsukuba Research Institute Research & Development Division, Sekisui Medical Co, Ltd, Ryugasaki, Japan.

Prebeta1-HDL, a putative discoid-shaped high-density lipoprotein (HDL) is known to participate in the retrieval of cholesterol from peripheral tissues. In this study, to clarify potential sources of this lipoprotein, we conducted heparin injection on four Japanese volunteer men and found that serum triglyceride (TG) level decreased in parallel with the increase in serum nonesterified fatty acids and plasma lipoprotein lipase (LPL) protein mass after heparin injection. Plasma prebeta1-HDL showed considerable increases at 15 min after the heparin injection in all of the subjects. In contrast, serum HDL-C levels did not change. Gel filtration with fast protein liquid chromatography system (FPLC) study on lipoprotein profile revealed that in post-heparin plasma, low-density lipoprotein and alphaHDL fractions did not change, whereas there was a considerable decrease in very low-density lipoprotein (VLDL) fraction and an increase in prebeta1-HDL fraction when compared with those in pre-heparin plasma. We also conducted in vitro analysis on whether prebeta1-HDL was produced during VLDL lipolysis by LPL. One hundred microliters of VLDL extracted from pooled serum by ultracentrifugation was incubated with purified bovine milk LPL at 37 degrees C for 0-120 min. Prebeta1-HDL concentration increased in a dose dependent manner with increased concentration of added LPL in the reaction mixture and with increased incubation time, indicating that prebeta1-HDL was produced during lipolysis of VLDL by LPL. Taken these in vivo and in vitro analysis together, we suggest that lipolysis of VLDL particle by LPL is an important source for formation of prebeta1-HDL.
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http://dx.doi.org/10.1016/j.bbrc.2008.11.146DOI Listing
January 2009

Use of an epidural cooling catheter with a closed countercurrent lumen to protect against ischemic spinal cord injury in pigs.

J Thorac Cardiovasc Surg 2007 Nov;134(5):1220-6

Department of Cardiovascular Surgery, Keio University School of Medicine, Tokyo, Japan.

Objective: We developed an epidural cooling catheter containing cold saline solution circulating in an isolated lumen. After placement by a minimally invasive approach, we evaluated protection effect against ischemic spinal cord injury in pigs.

Methods: Fourteen pigs underwent thoracic aortic double clamping for 45 minutes under systemic mild hypothermia (36 degrees C). Group A (n = 7) underwent local hypothermia with the cooling catheter. Group B (n = 7) underwent catheter placement only, without cooling. Spinal cord somatosensory evoked potentials were recorded to assess electrophysiologic status. Neurologic function was evaluated with a modified Tarlov score.

Results: At aortic crossclamping, spinal temperature in group A (26.5 degrees C +/- 2.4 degrees C) was significantly lower than that in group B (35.3 degrees C +/- 0.6 degrees C, P = .0001). Mean time from aortic crossclamping to onset of potential loss was significantly longer in group A (28.4 +/- 6.6 minutes) than in group B (18.3 +/- 5.0 minutes, P = .007). Mean duration of total loss of potentials was significantly shorter in group A (19.0 +/- 6.7 minutes) than that in group B (31.3 +/- 5.9 minutes, P = .003). Group A showed significantly better neurologic function (mean Tarlov score 4.4 +/- 0.8) than that of group B (0.1 +/- 0.4, P = .0001). Mean total number of intact motor neurons was significantly greater in group A (24.5 +/- 6.8) than that of group B (9.9 +/- 6.8, P = .0001).

Conclusion: By cooling the spinal cord selectively and continuously, the newly designed epidural cooling catheter prevented ischemic injury in a pig model of aortic crossclamping.
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http://dx.doi.org/10.1016/j.jtcvs.2007.06.015DOI Listing
November 2007

Protective use of N-methyl-D-aspartate receptor antagonists as a spinoplegia against excitatory amino acid neurotoxicity.

J Vasc Surg 2005 Oct;42(4):765-71

Department of Cardiovascular Surgery, Keio University, Tokyo, Japan.

Objective: Paraplegia remains a serious complication of thoracic and thoracoabdominal aortic operations. To avoid this dreadful complication, N-methyl-D-aspartate (NMDA) receptor antagonists have been examined in the ischemic or excitotoxic neuronal injury model. In the present study, we evaluated the protective efficacy of NMDA receptor antagonists that were infused segmentally after aortic clamping, as a spinoplegia, to reduce aspartate neurotoxicity in the spinal cord.

Methods: Infrarenal aortic isolation was performed in New Zealand white rabbits. Group A animals (n = 7) were pretreated with the segmental infusion of MK-801, a noncompetitive NMDA receptor antagonist, followed by segmental aspartate (50 mmol) infusion for 10 minutes. Group B animals (n = 6) received pretreatment with CGS19755, a competitive NMDA receptor antagonist, followed by the same aspartate infusion as group A. Group C animals (n = 7) received vehicle only, followed by aspartate infusion as a control group. In addition, group D animals (n = 6) were pretreated with MK-801 that was administrated intravenously 1 hour before aspartate infusion. Neurologic status was assessed at 12, 24, and 48 hours after operation by using the Tarlov score. The spinal cords were procured at 48 hours for histopathologic analysis to determine the extent of excitotoxic neuronal injury.

Results: Most of the animals in groups A and D revealed full recovery or mild motor disturbance. Group B and C animals exhibited paraplegia or paraparesis with marked neuronal necrosis. In the Tarlov score at 48 hours, group A animals represented better neurologic function than group C (P < .01) and similar motor function to group D animals. Severe histopathologic change was not observed in groups A and D. Animals in groups A and D showed a greater number of motor neurons than animals in groups B and C (P < .01). The difference could be due to chance between group A and D animals (P = .08).

Conclusions: These results showed that the segmental infusion of noncompetitive NMDA receptor antagonist as an intraoperative spinoplegia could have a protective effect on the spinal cord neurons against excitotoxic neuronal injury in vivo. On the other hand, efficacy of the use of competitive antagonist was suggested to be limited in this model, probably because of the insurmountable obstacle of the blood-brain barrier.

Clinical Relevance: Paraplegia is a devastating complication during surgical repair of the thoracic and thoracoabdominal aortas. Excitatory amino acids neurotoxicity through the N-methyl-D-aspartate (NMDA) receptor is no doubt the pathologic hallmark of ischemic and postischemic spinal cord injury. Systemic administration of either a competitive or noncompetitive NMDA antagonist has been reported to have neuroprotective effect, in terms of preoperative treatment, with dose-related central sympathomimetic and sedative effects. Local administration, particularly of a noncompetitive NMDA antagonist, infused segmentally after aortic clamping could therefore be a potent intraoperative pharmacologic strategy to minimize the effective dose that retains NMDA antagonism without undesirable adverse effects. Our ability to reproduce this model could facilitate pharmacologic prevention or provide a new surgical technique as a spinoplegia for NMDA receptor-mediated neuronal injury.
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http://dx.doi.org/10.1016/j.jvs.2005.05.052DOI Listing
October 2005

An epidural cooling catheter protects the spinal cord against ischemic injury in pigs.

Ann Thorac Surg 2005 Nov;80(5):1829-33

Department of Cardiovascular Surgery, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.

Background: Using swine, we investigated whether epidural placement of a cooling catheter rather than infusing iced saline solution could protect the spinal cord from ischemia during aortic surgery.

Methods: We divided 14 domestic pigs into two groups of 7 each. Each underwent epidural catheter placement preceding 30 minutes of aortic cross-clamping distal to the origin of the left subclavian artery. In group 1, cold water was circulated continuously through the lumen of the catheter connected to an external unit. In group 2, animals received catheter placement without cooling. Spinal cord somatosensory evoked potentials were recorded. Neurologic status involving hind limbs was graded sequentially after surgery.

Results: At aortic cross-clamping, spinal temperature in group 1 (31.7 degrees +/- 0.6 degrees C) was significantly lower than in group 2 (37.8 degrees +/- 0.4 degrees C; p < 0.0001). No significant elevation of intrathecal pressure accompanied cooling with the catheter (group 1, 8.1 +/- 1.7 mm Hg; group 2, 8.0 +/- 1.5 mm Hg). Mean duration of total loss of potentials was significantly shorter in group 1 (7.4 +/- 3.8 minutes) than group 2 (19.7 +/- 7.3 minutes; p = 0.0002). Pigs in group 1 exhibited better hind limb function recovery (mean Tarlov score, 4.7 +/- 0.5) than group 2 (0.6 +/- 0.8; p = 0.0017). Group 1 showed normal histologic characteristics, whereas group 2 showed loss of motor neurons in the ventral horns.

Conclusions: Epidural cooling catheter without iced saline infusion can cool the spinal cord without elevating intrathecal pressure, protecting the cord against ischemia.
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http://dx.doi.org/10.1016/j.athoracsur.2005.04.031DOI Listing
November 2005

Effect of the free radical scavenger MCI-186 on spinal cord reperfusion after transient ischemia in the rabbit.

Jpn J Thorac Cardiovasc Surg 2005 Aug;53(8):426-33

Division of Cardiovascular Surgery, Saitama Municipal Hospital, Saitama, Japan.

Objective: Paraplegia remains a serious complication of aortic operations. The production of free radicals during reperfusion after transient ischemia is believed to induce secondary spinal neuronal injury, resulting in paraplegia. The aim of the present study was to clarify the protective effect and method of administration of antioxidants on the neurological and histological outcome in the animal model for reperfusion injury after transient spinal cord ischemia.

Methods: New Zealand white rabbits underwent surgical exposure of the abdominal aorta that was clamped for 15 minutes to achieve spinal cord ischemia. Group A animals received two 10 mg/kg doses of 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186) at the time of release of the aortic clamp and 30 minutes later. In group B, MCI-186, 5 mg/kg, was given three times, at the time of aorta clamp release, 30 minutes and 12 hours later. In group C (control group), one dose of vehicle was administered. Neurological status was assessed using modified Tarlov's score until 168 hours after operation. Spinal cord sections were examined microscopically to determine the extent of ischemic neuronal damage.

Results: Groups A and B animals had better neurological function than group C (p < 0.001). In contrast, group C animals exhibited paraplegia or paraparesis with marked neuronal necrosis. The number of surviving neurons within examined sections of the spinal cord was significantly greater in group B than in group C (p < 0.001).

Conclusion: In a 15-minute ischemia-reperfusion model using rabbits, systemic repetitious administration of MCI-186, a free radical scavenger, was found to have a protective effect on the spinal cord neurons both neurologically and histologically. We postulate that the drug minimizes the delayed neuronal cell death for reperfusion injury after transient ischemia by reducing the free radical molecules. Moreover, it was thought that we could protect delayed neuronal cell death more effectively by administering MCI-186 12 hours later.
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http://dx.doi.org/10.1007/s11748-005-0078-7DOI Listing
August 2005

Beating-heart epicardial radiofrequency ablation: optimal temperature setting.

Ann Thorac Surg 2004 Jul;78(1):308-11; discussion 312

Department of Cardiovascular Surgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Tochigi, Japan.

Purpose: Pulmonary vein isolation is a simple procedure, which has recently been reported as an effective treatment for the termination of atrial fibrillation. Although there are several clinical reports of beating-heart epicardial ablation, the optimal temperature has not been experimentally investigated. We evaluated the effective temperature for the placement of circular lesions around the pulmonary vein-left atrial junction.

Description: Twelve swine underwent epicardial ablation to create linear conduction block lesions around the pulmonary vein-left atrial junction by a seven-electrode ablation catheter. The ablation was performed at 60 degrees C (group I), 70 degrees C (group II), 80 degrees C (group III), and 90 degrees C (group IV) for 120 seconds. The creation of a firm conduction block across the ablated lesion under pacing was compared.

Evaluation: Complete conduction block was observed in all groups except group I. However, heat injury to adjacent structures in group IV and transient discoloration of the tissue surrounding coronary arteries in groups III and IV were observed.

Conclusions: The effective temperature for epicardial radiofrequency pulmonary vein isolation was 120 minutes and above 70 degrees C.
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http://dx.doi.org/10.1016/S0003-4975(03)01163-9DOI Listing
July 2004

Neuroprotective effects of N-methyl-D-aspartate receptor antagonist on aspartate induced neurotoxicity in the spinal cord in vivo.

Jpn J Thorac Cardiovasc Surg 2003 Oct;51(10):500-5

Department of Cardiovascular Surgery, Keio University, Tokyo, Japan.

Objective: Much evidence has been gathered to show that neurotoxicity of excitatory amino acids is mainly activated through an N-methyl-D-aspartate (NMDA) receptor cascade. We evaluated the protective effects of NMDA receptor antagonists, MK-801 and CGS19755 on spinal cord neurons using the NMDA receptor mediated neurotoxicity model in vivo.

Methods: New Zealand white rabbits underwent an infrarenal aortic isolation. Group A animals (n = 7) received segmental aspartate (50 mM) infusion for 10 minutes. Group B animals (n = 6) were pretreated with MK-801 (6mg/kg), a noncompetitive NMDA receptor antagonist, that was administrated intravenously for 3 hours beginning 1 hour before the segmental infusion of aspartate (50 mM) of 10 minutes. Group C animals (n = 6) received pretreatment with CGS19755 (30mg/kg), a competitive NMDA receptor antagonist, that was administrated in the same fashion as group B, followed by the segmental infusion of aspartate (50 mM). Neurologic status was scored at 12, 24, and 48 hours after operation using the Tarlov score. All the animals were sacrificed for histologic assessment at 48 hours.

Results: Group A animals exhibited paraplegia or paraparesis with marked neuronal necrosis. Group B and C animals showed significantly better neurologic function compared with group A (p = 0.0013, A vs. B) (p = 0.0011, A vs. C). Pathohistological change was not observed in group B and C animals.

Conclusions: NMDA receptor antagonists can have protective effects on spinal cord neurons against aspartate induced neurotoxicity. This model may be useful in assaying protective agents in the spinal cord against neuronal injury mediated by NMDA receptors in vivo.
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http://dx.doi.org/10.1007/s11748-003-0110-8DOI Listing
October 2003

Aortic intramural hematoma with severe aortic regurgitation.

Jpn J Thorac Cardiovasc Surg 2003 May;51(5):198-200

Department of Cardiovascular Surgery, Saiseikai Utsunomiya Hospital, Tochigi, Japan.

A 71-year-old Japanese woman with severe chest pain was diagnosed with Stanford type A acute aortic dissection. After 3 months of medical treatment, she was operated on under a diagnosis of dissecting aneurysm of the ascending aorta and severe aortic regurgitation. Operative findings showed prolapse of the redundant aortic leaflets and a dilated ascending aorta without intimal tears. Operative and computed tomography findings differed from those of a classical dissection, which was the primary diagnosis of this patient, and were compatible with a diagnosis of aortic intramural hematoma (IMH). Few reports of IMH include concomitant aortic regurgitation. Surgery involved aortic root remodeling and prosthetic graft replacement of the ascending aorta.
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http://dx.doi.org/10.1007/s11748-003-0031-6DOI Listing
May 2003
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