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

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.

Resection of an intrapericardial lipoma with nonsustained ventricular tachycardia.

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.

Pacemaker Relocation for Radiation Against Overlapping Lung Cancer.

We experienced a patient after pacemaker (PM) implantation who had lung cancer of the left upper lobe that developed just behind the PM. The patient was an 81-year-old man with many complications. Radiation was the only treatment option. The PM had to be moved to another place to avoid direct radiation exposure to it. An epicardial pacing lead was implanted on the right ventricular epicardium, and the new generator was implanted in the abdomen. The patient was treated with a total of 62 Gy of radiotherapy for lung cancer, achieving a temporary shrinkage of the tumor. During the radiotherapy period, the PM functioned well without harmful events. When radiation therapy is needed in cases where the tumor overlaps the PM, relocation surgery using an epicardial pacing lead may be a useful option.

Emergency Endografting for Spontaneous Thoracic Aortic Rupture.

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.

Creation of an Analytical Model of Spinal Cord Cooling by Epidural Catheter for Preventing Paraplegia.

Introduction Paraplegia is a serious complication after thoracic and thoracoabdominal aortic aneurysm surgery. The aortic cross-clamp blocks blood flow to the intercostal artery as a feeding blood vessel, so the spinal cord is at risk of being exposed to ischemia. Hypothermia with systemic cooling is a useful means of avoiding spinal ischemia caused by aortic blockade but has various side effects. Theoretically, local cooling by epidural cooling catheter is an effective method to reduce the side effects. However, the use of needle sensors to measure the temperature of the human spinal cord is not ethically applicable in the real clinical field. The purpose of the study is to build computer modeling of human-sized spinal cords and a basic platform for simulating spinal cord cooling. This is being done to prove that local cooling can cool the human spinal cord in the same way, even in human spinal cords larger than laboratory animals. Methods We tried to model a horizontal cross-section of tissue near the spinal cord at a size equivalent to that of an adult human. The tissue around the spinal cord was decomposed into many small matrices for analysis using the finite element method. Next, the analysis was performed using a high-speed computer on the assumption that the matrix exchanges heat with the adjacent matrix over time according to Pennes' bio-heat equation. Repeated calculations were performed on a high-speed computer to calculate temperature changes in the central part of the spinal cord. Result By setting the temperature of the cooling catheter to 20°C, temperatures at the center of the spinal cord after 5, 10, 15, 20 and 25 minutes were 34.08°C, 33.64°C, 33.48°C, 33.40°C, and 33.36°C, respectively. After stopping the cooling, the temperature at the center of the spinal cord recovered to baseline temperature within 10 minutes. Conclusion Results were similar to those of previous animal studies using our local cooling system, suggesting that evaluation of cooling catheter's performance by computational simulation (CS) is effective.

Coronary Artery Fistula Aneurysm: Pathological Analysis After Surgery.

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.

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

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.

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

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.

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

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.

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

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.

Aortic intramural hematoma with severe aortic regurgitation.

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.

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

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.

Mediastinal schwannoma diagnosed preoperatively as a cyst.

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.

Thoracic and thoracoabdominal aortic repair under regional spinal cord hypothermia.

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.

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

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.

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

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.

Malignant solitary fibrous tumor of the left ventricular epicardium.

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.

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

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.

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

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.