Keijiro Katayama

Multiple factors predict the risk of spinal cord injury after the frozen elephant trunk technique for extended thoracic aortic disease

OBJECTIVES Spinal cord injury (SCI) after the frozen elephant trunk (FET) technique is more frequent than after endovascular aneurysm repair. This study aimed to identify risk factors of SCI after the FET technique. METHODS We performed the FET technique for extended thoracic aortic disease in 224 patients (mean age, 72.1 ± 10.9 years) from September 1997 to December 2011. The patients included those with acute type A aortic dissection (n = 103), acute type B aortic dissection (n = 30), chronic type B aortic dissection (n = 11) and thoracic atherosclerotic aneurysm (n = 80). Cerebrospinal fluid drainage (CSFD) was preoperatively performed for 18 elective cases with a high risk of spinal cord ischaemia from January 2003. RESULTS Postoperative SCI was present in 8 (3.5%), including complete paraplegia in 3, patients and transient or permanent paraparesis in 5 patients. CSFD was not a significant independent risk factor (P = 0.93) for SCI. Univariate logistic regression analysis identified pathology (P = 0.001), diabetes (P = 0.001), previous aortic operation (P = 0.003), atherosclerotic aorta (P = 0.003), distal position of the stent graft below the ninth thoracic vertebral level (Th9; P = 0.001) and low blood pressure after the operation (P = 0.009) as significant independent risk factors for SCI. Stepwise logistic regression analysis identified the distal position of the stent graft below Th9 (P = 0.003; odds ratio [OR], 15.167; 95% confidence interval [95% CI], 2.568-89.578), mean pressure <70 mmHg (P = 0.008; OR, 11.470; 95% CI, 1.920-68.546) and diabetes (P = 0.009; OR, 9.621; 95% CI, 1.779-52.032) as significant independent risk factors for SCI. CONCLUSIONS There were multiple factors predicting the risk of SCI after the FET technique. Paraplegia may be prevented by avoiding deep insertion of the stent graft and by keeping blood pressure elevated after the operation.

The frozen elephant trunk technique for acute type A aortic dissection: results from 15 years of experience

OBJECTIVES We aimed to evaluate the long-term prognosis of prophylactic repair of the descending aorta using the frozen elephant trunk (FET) technique for acute type A aortic dissection (AAAD). METHODS Between 1997 and 2012, 120 consecutive patients (mean age: 64.4 ± 10.9 years) underwent total arch replacement with FET for AAAD; 36 patients had an entry at the descending aorta, 68 patients were aged <70 years and 8 patients had Marfans syndrome. With regard to preoperative morbidity, 23 patients had stroke, 10 had coronary ischaemia and 9 had visceral ischaemia. During intraoperative measurement, the required size and length of the stent graft were determined and inserted under transoesophageal echographic guidance. RESULTS Seven patients (6%) died in the hospital. Four (3%) cases of stroke and 2 (2%) with spinal cord injuries were noted. Computed tomography prior to discharge indicated complete thrombosis of the false lumen by the stent graft in 113 patients, with a mean diameter of 26.0 ± 2.5 mm before discharge and 27.5 ± 2.5 mm at 1 year postoperatively compared with a mean stent graft diameter of 27.8 ± 1.7 mm. During the long-term follow-up (mean period: 104.6 ± 51.9 months), 12 patients died of non-aortic events and 5 distal aortic reoperations were required using endovascular stent grafting of the descending aorta, including 1 case with new tear formation. None of the patients had a patent false lumen on the stent graft at the final follow-up. The 10-year survival rate was 75% and the overall 10-year reoperation-free rate on the thoracic aorta was 93%. CONCLUSIONS The FET technique results in excellent aortic remodelling of the downstream aorta and can improve the long-term outcomes for AAAD.

Intraoperative direct hemoperfusion with a polymyxin-B immobilized fiber column for treatment of infective endocarditis

PurposeEndotoxin adsorption treatment (direct hemoperfusion using a polymyxin-B immobilized fiber column, or PMX-DHP) is now considered a useful option for treating severe sepsis. However, the efficacy of PMX-DHP for infective endocarditis (IE), in which the causative microorganisms are usually Gram-positive cocci, remains unclear. In the present study, we investigated the impact of intraoperative PMX-DHP on clinical parameters during the treatment of IE.MethodsFrom November 2006 to December 2009, a total of 11 patients with active IE underwent emergent surgery using intraoperative PMX-DHP. The perioperative courses of these patients were compared with those of seven patients who underwent emergent surgery for active IE with the conventional method from January 2003 to October 2006.ResultsPMX-DHP was associated with a significant decrease in the postoperative catecholamine dose and duration. Intubation time and intensive care unit length of stay for the PMX-DHP group was significantly shorter than that for the conventional therapy group. There was also a significant difference in the number of failed organs postoperatively between the two groups.ConclusionIntraoperative PMX-DHP demonstrated several positive effects, such as a drastic decrease in the doses of inotropic agents and shortening of the duration of mechanical ventilation, in patients who underwent emergent surgery for active IE. Intraoperative PMX-DHP can be a useful option for the treatment of critically ill patients with IE.

Efficacy of Cardiopulmonary Rehabilitation With Adaptive Servo-Ventilation in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

BACKGROUND Postoperative complications after cardiac surgery increase mortality. This study aimed to evaluate the efficacy of cardiopulmonary rehabilitation with adaptive servo-ventilation (ASV) in patients undergoing off-pump coronary artery bypass grafting (OPCAB). METHODS AND RESULTS A total of 66 patients undergoing OPCAB were enrolled and divided into 2 groups according to the use of ASV (ASV group, 30 patients; non-ASV group, 36 patients). During the perioperative period, all patients undertook cardiopulmonary rehabilitation. ASV was used from postoperative day (POD) 1 to POD5. Hemodynamics showed a different pattern in the 2 groups. Blood pressure (BP) on POD6 in the ASV group was significantly lower than that in the non-ASV group (systolic BP, 112.9±12.6 vs. 126.2±15.8 mmHg, P=0.0006; diastolic BP, 62.3±9.1 vs. 67.6±9.3 mmHg, P=0.0277). The incidence of postoperative atrial fibrillation (POAF) was lower in the ASV group than in the non-ASV group (10% vs. 33%, P=0.0377). The duration of oxygen inhalation in the ASV group was significantly shorter than that in the non-ASV group (5.1±2.2 vs. 7.6±6.0 days, P=0.0238). The duration of postoperative hospitalization was significantly shorter in the ASV group than in the non-ASV group (23.5±6.6 vs. 29.0±13.1 days, P=0.0392). CONCLUSIONS Cardiopulmonary rehabilitation with ASV after OPCAB reduces both POAF occurrence and the duration of hospitalization.

Total arch repair using supra-aortic debranching technique with banding of the ascending aorta for endovascular stent graft fixation.

Endovascular stenting requires a satisfactory landing zone that guarantees fixation and sealing of the proximal part of the endograft. We report total arch repair using supra-aortic debranching technique with banding of the ascending aorta for endovascular graft fixation. An 85-year-old man presented with hoarseness of voice. A fusiform aneurysm with a maximum transverse diameter of 62 mm on the aortic arch was identified by computed tomographic angiography. Supra-aortic arch debranching of the 3 neck vessels using a trifurcated graft and coronary arterial bypass grafting were performed while closely monitoring the regional cerebral oxygen saturation. The ascending aorta was dilated to 41 mm; we successfully reduced this to a mean outer diameter of 36 mm by banding the aorta using an expanded polytetrafluoroethylene surgical membrane. The endovascular procedure was performed 17 days after surgical intervention. The patient was extubated immediately after endovascular stent placement and spent 1 day in intensive care with no signs of transient or permanent neurologic events. A postoperative computed tomographic scan did not reveal any evidence of endoleak. The banding of the ascending aorta for endovascular graft fixation could facilitate endovascular aortic arch repair and provide an alternative treatment for high-risk patients.

Mesenchymal Stem Cell-Based Therapy Improves Lower Limb Movement After Spinal Cord Ischemia in Rats

BACKGROUND Spinal cord ischemia is a devastating complication after thoracic and thoracoabdominal aortic operations. In this study, we aimed to investigate the effects of mesenchymal stem cells (MSCs), which have regenerative capability and exert paracrine actions on damaged tissues, injected into rat models of spinal cord ischemia-reperfusion injury. METHODS Forty-five Sprague-Dawley rats were divided into sham, phosphate-buffered saline (PBS), and MSC groups. Spinal cord ischemia was induced in the latter two groups by balloon occlusion of the thoracic aorta. MSCs and PBS were then immediately injected into the left carotid artery of the MSC and PBS groups, respectively. Hindlimb motor function was evaluated at 6 and 24 hours. The spinal cord was removed at 24 hours after ischemia-reperfusion injury, and histologic and immunohistochemical analyses and real-time polymerase chain reaction assessments were performed. RESULTS Rats in the MSC and PBS groups showed flaccid paraparesis/paraplegia postoperatively. Hindlimb function was significantly better at 6 and 24 hours after ischemia-reperfusion injury in the MSC group than in the PBS group (p < 0.05). The number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive neuron cells in the spinal cord and the ratio of Bax to Bcl2 were significantly larger (p < 0.05) in the PBS group than in the MSC group. The injected MSCs were observed in the spinal cord 24 hours after ischemia-reperfusion injury. CONCLUSIONS The MSC therapy by transarterial injection immediately after spinal cord ischemia-reperfusion injury may improve lower limb function by preventing apoptosis of neuron cells in the spinal cord.

Abdominal organ protection strategy for aortic arch aneurysm surgery

Introduction: Body temperature maintained during open distal anastomosis in patients who undergo aortic surgery has been showing an upward trend; however, a higher temperature may increase visceral organ and spinal cord injury. Distal perfusion may reduce abdominal organ injury, especially acute kidney injury (AKI). Methods: From 2009 to 2016, 56 patients who underwent ascending aortic and/or aortic arch surgery were enrolled. Open distal anastomosis was performed using one of three protection strategies: 1) systemic temperature of 25°C followed by selective cerebral perfusion (SCP) with lower body circulatory arrest (Group CA25, n=27); 2) systemic temperature of 28°C followed by SCP with lower body circulatory arrest (Group CA28, n=4); and 3) systemic temperature of 28°C followed by SCP with distal aortic perfusion (Group DP, n=25). Results: During the postoperative course, levels of blood urea nitrogen, creatinine, liver enzymes, lactate dehydrogenase and lactate in Groups CA28 and CA25 were significantly higher than those in Group DP. AKI defined by the AKI Network occurred in 28 cases (50%) and 3 cases required permanent hemodialysis. AKI was significantly higher in Groups CA25 and CA28 than in Group DP (p=0.026). Mid-term follow-up showed that patients who developed postoperative AKI were more likely to suffer from cardiovascular events. Conclusions: Distal perfusion during open distal anastomosis reduced kidney and liver injury after thoracic aortic surgery despite an increased body temperature of up to 28°C. This strategy may be useful to prevent AKI, liver dysfunction, the need for hemodialysis and multiple organ failure and could improve mid-term results.

Endovascular stent graft for aortoesophageal fistula caused by esophageal stent.

A 71-year-old woman with lung cancer was admitted due to hemodynamic shock with massive hematemesis that was caused by an aortoesophageal fistula 3 months after implantation of an Ultra-flex esophageal stent. Computed tomography demonstrated an aortoesophageal fistula with an ulcer-like projection on the aortic arch where the esophageal stent touched, on axial and sagittal scans (Figure 1). We performed emergency endovascular aortic repair from zone 2, using a stent graft with simple coverage of the left subclavian artery via the right common iliac artery, through a right retroperitoneal approach. The patient was well without hemostasis and could eat 2 weeks after aortic repair. Computed tomography demonstrated complete thrombosis (Figure 2).

Prosthetic Valve Endocarditis Caused by ST8 SCC mec IVl Type Community-associated Methicillin-resistant Staphylococcus aureus : A Case Report

The emergence of a Japan-intrinsic community associated methicillin-resistant Staphylococcus aureus strain (CA-MRSA/J) has been reported. A 70-year-old man with recurrent colon cancer and a history of mitral valve replacement was admitted to the hospital in a state of shock. He was diagnosed with prosthetic valve endocarditis (PVE) caused by MRSA and underwent cardiac surgery. The MRSA isolates belonged to multilocus sequence type 8 and carried staphylococcal cassette chromosome mec IVl and the genes of toxic shock syndrome toxin-1, enterotoxin C, and enterotoxin L. These characteristics indicated a CA-MRSA/J clone. This is the first reported case of PVE caused by CA-MRSA/J.

Abdominal aortic aneurysm with occlusion of three primary mesenteric vessels treated by surgery with perfusion of the left iliac artery

A 64-year-old woman who underwent thoraco-abdominal aortic replacement for a Crawford type II aneurysm 11 years ago was referred to our hospital because of a residual juxtarenal abdominal aortic aneurysm. The coeliac, superior mesenteric and inferior mesenteric arteries were occluded. Collateral vessels from the left internal iliac artery to these 3 mesenteric arteries had developed. We performed open aneurysm repair using an extracorporeal circuit to maintain collateral flow to these mesenteric arteries.