Kazunori Komatsu

Upregulation of the apoptosis-related inflammasome in cardiac allograft rejection

BACKGROUND Inflammation is a major factor in cardiac allograft rejection. Accumulating reports have demonstrated an important role of the inflammation-induced adaptor complex, called the inflammasome, in the field of immunology. The apoptosis-associated, speck-like protein containing a caspase recruitment domain (ASC) is an adaptor protein that forms the inflammasome and regulates caspase-1-dependent generation of inflammatory cytokines. The aim of the present study was to determine how ASC is associated with the development of cardiac allograft rejection. METHODS We used a murine heterotopic cardiac transplantation model between fully incompatible strains. Donor hearts (n = 9 for each time-point) were harvested for examination on Days 1, 4, 7 and 12 after transplantation. Histopathologic findings of cardiac grafts were evaluated using rejection scores. The expression of ASC and inflammatory cytokines in cardiac grafts were analyzed by immunohistochemistry and real-time reverse transcript-polymerase chain reaction (RT-PCR). RESULTS Expression levels of both ASC and IL-1 beta were higher in the myocardial interstitium of allografts in parallel to the progress of cardiac rejection during the acute phase after transplantation. In contrast, expression of ASC and IL-1 beta remained low in isografts. Cardiac allografts treated with tacrolimus showed decreased expression of both ASC and IL-1 beta similar to that seen in isografts. Real-time RT-PCR demonstrated similar alteration of ASC and IL-1 beta mRNA expression in cardiac grafts during the acute phase. CONCLUSIONS Our results demonstrate a novel finding showing that upregulation of ASC is closely associated with the inflammation induced in cardiac grafts after transplantation in the mouse.

Surgical Outcomes of Acute Type A Aortic Dissection in Elderly Patients

BACKGROUND Age is still considered a risk factor in the repair of acute type A aortic dissection. Instead of total arch replacement, we performed hemiarch or partial arch replacement with intimal tear exclusion to reduce death in elderly patients and evaluated early-term and midterm outcomes. METHODS From January 2004 to April 2012, 59 patients older than 70 years (mean age, 77.0±4.3 years) underwent emergency operations for acute type A aortic dissection at our institution. We performed hemiarch, partial arch, or total arch replacement, according to the location of the primary entry tear. The characteristics, surgical procedures, and early-term and midterm outcomes of these patients were reviewed. RESULTS We performed hemiarch replacement in 47 patients, partial arch replacement in 4, and total arch replacement in 8. The primary entry site was excluded in 56 of 59 patients (94.9%). In-hospital mortality was 6.8%, and neurologic impairment occurred in 25.4%. We obtained midterm outcomes for 55 of 59 patients, with a mean follow-up period of 43.9±23.7 months. Fourteen patients died, two of these of aortic-related causes. One patient required repeat aortic operation for rupture of a pseudoaneurysm. Follow-up computed tomography imaging was done in 28 of 55 patients during the 12 months after the operation. No significant difference was noted in the increase in maximal aortic diameter between patients with and without residual dissection. CONCLUSIONS In-hospital mortality was 6.8%; relatively low compared with previous reports. Hemiarch and partial arch replacement with entry tear exclusion may reduce deaths associated with acute type A aortic dissection repair in elderly patients, without increasing the risk of reoperation and aortic-related death.

Tracheo-Bronchial Obstruction and Esophageal Perforation after TEVAR for Thoracic Aortic Rupture.

A 67-year-old man was referred to our hospital for an ascending aortic aneurysm, thoracoabdominal aortic aneurysm and aortic regurgitation. Graft repair of the thoracic aortic arch and aortic valve replacement was given priority and completed, however he developed descending aortic rupture before the second scheduled surgery, and endovascular stent grafting was performed. He subsequently developed tracheobronchial obstruction and esophageal perforation. The patient underwent urgent esophagectomy and enterostomy with continuity later reestablished. However, he died of sepsis 5 months after surgery. Despite the less invasive nature of endovascular treatment, esophageal perforation can nevertheless occur and postoperative vigilance is well warranted.

Innovative Application of Available Stent Grafts in Japan in Aortic Aneurysm Treatment—Significance of Innovative Debranching and Chimney Method and Coil Embolization Procedure

OBJECTIVE We here describe our experience with innovative uses of these devices. PATIENTS AND METHODS We reviewed treatment outcomes of 310 endovascular abdominal aortic repair (EVAR) and 83 thoracic endovascular aortic repair (TEVAR) cases performed between August 2007 and February 2012. We separately assessed results in elderly and high-risk patients who had a novel procedure. This group included 94 patients who underwent EVAR with IIA embolization, 10 patients who had EVAR and a renal artery chimney procedure for a short aortic neck, 20 patients who had two de-branching TEVAR or Chimney method for thoracic aortic aneurysms (TAA) and 3 patients who had debranching TEVAR for thoracic abdominal aortic aneurysms (TAAA). RESULTS Of the 393 patients given stent grafts (SGs), 3 (0.8%) died in the hospital, including 1 patient with pneumonia who underwent EVAR and IIA embolization and 1 patient with a cerebral infarction who had TEVAR. Four patients (4.3%) who were treated with EVAR with internal iliac artery (IIA) embolization presented with residual buttock claudication 6 months postoperatively, and 3 patients (3.2%) had onset of ischemic enteritis; however, in all 7 patients, the condition resolved without additional intervention. In the 10 patients who had EVAR and a renal artery chimney method, the landing zone (LZ) was ≤10 mm, but neither endoleak nor renal artery occlusion was observed perioperatively or during midterm follow-up. Of the 20 patients who had a 2-debranching TEVAR, including 9 in whom the chimney method was used with the LZ in zone 0, 1 (5%) had a residual endoleak. In 3 patients with TAAA, we used SGs to cover 4 abdominal branches and bypassed the visceral artery; the outcomes were good, with all patients being ambulatory at hospital discharge. CONCLUSION Among innovative SGs treatments, the debranching procedure and the chimney method using catheterization and the coil-embolization technique provided good outcomes, as used in addition to surgical procedures. Aortic aneurysm treatment will become increasingly noninvasive with the continuing development of more innovative ways to use the SGs currently available in Japan. (English Translation of Jpn J Vasc Surg 2012; 21: 165-173).

Mediastinal Mature Teratoma With Rupture Into Pleural Cavity Due to Blunt Trauma

We report a rare case of mediastinal mature teratoma with rupture due to blunt trauma. A 15-year-old boy had received a strong head-butt in the left upper chest wall and was admitted with the sudden onset of left-sided severe chest pain and dyspnea. Chest computed tomography (CT) scan on admission revealed a heterogeneous mass lesion in the anterior mediastinum. The contrast-enhanced CT scans obtained 2 days after admission showed not only mediastinal mass lesion but also left pleural effusion. On the radiologic finding at 5 months later, the lesion became larger and was thought to be a typical mediastinal mature teratoma. The patient underwent extirpation of the tumor. Microscopically, the tumor was typically composed of adult-type tissues and was confirmed to be mature teratoma.

Delayed Esophageal Perforation Secondary to Thoracic Aortic Aneurysm Rupture in a Patient with Human Immunodeficiency Virus Infection

A 65-year-old man infected with human immunodeficiency virus underwent emergency surgery for rupture of a mycotic descending thoracic aneurysm. The aneurysm was replaced with a prosthetic graft wrapped with omentum. Esophageal perforation occurred 3 weeks after surgery. The patients condition remained stable, and we adopted a conservative treatment. The esophageal fistula had not healed completely and a biopsy of the scar revealed gastric cancer. We performed a distal gastrectomy, Roux-Y reconstruction, and enterostomy for enteral feeding. Follow-up endoscopy revealed healing of the fistula, and the patient was eventually discharged. We managed this potentially fatal complication with minimally invasive treatment.

A Case of Traumatic Retrograde Type A Aortic Dissection Accompanied by Multiorgan Injuries

A 75-year-old woman was involved in a traffic accident and suffered retrograde type A aortic dissection, multiple rib fractures, and grade II hepatic injury accompanied by intraperitoneal bleeding. We performed total arch replacement using an open stent graft with cardiopulmonary bypass and circulatory arrest. This procedure requires anticoagulation and hypothermia, which are principally contraindicated in severe trauma patients. However, this situation was resolved by managing the patient non-operatively for 7 days, confirming the stabilization of other injured organs, and then performing the surgery. She required prolonged postoperative rehabilitation; however, she recovered steadily.

Anaplastic Large-Cell Lymphoma of the Left Ventricle Presenting With Arrhythmia and Cerebral Infarction due to Cardiogenic Embolism

To the Editor: Anaplastic large-cell lymphoma (ALCL) frequently affects lymph nodes, with extranodal involvement of the skin, bone, soft tissue, lungs, and liver.[1–3] However, there are few reports of cardiovascular involvement of ALCL.[4,5] Here, we report a pediatric case of anaplastic lymphoma kinase (ALK)-positive ALCL presenting with a cardiac tumor and cardiogenic embolism. A 15-year-old male complained of high-grade fever and bilateral cervical lymphadenopathy. His symptoms persisted after the administration of antibiotics for 1 month. A needle biopsy specimen of the affected lymph node indicated

Pseudoaneurysm fistulated into the right atrium after double valve replacement.

We discuss a rare case of an ascending aorta pseudoaneurysm fistulating into the right atrium following prior aortic and mitral valve replacement. Transthoracic echocardiography and computed tomography revealed a pseudoaneurysm of the ascending aorta attached to the right atrium with fistulous communication. The pseudoaneurysm arose from the center of the former aortotomy. Emergency remedian sternotomy was performed without aneurysmal injury and with exposure of the left femoral artery and femoral vein. Aneurysmal resection and ascending aorta repair were performed without complication. Exposing peripheral vessels, and initiating cardiopulmonary bypass only after reentry, might be effective in resternotomy to approach ascending aorta pseudoaneurysms.

Early bioprosthetic valve calcification with alfacalcidol supplementation

We report a case of early bioprosthetic valve calcification in a 76 year-old woman who had received supplementation with alfacalcidol, an analogue of vitamin D, for 3 years after her initial valve replacement. She underwent aortic valve replacement at the age of 71 and subsequently complained of shortness of breath. Ultrasonic cardiography revealed severe aortic stenosis and we performed a second aortic valve replacement with a bioprosthesis. Histopathologic and x-ray examination showed calcification on the explanted valve. She had not presented with any known risk for early bioprosthetic calcification, suggesting that vitamin D supplementation may accelerate calcification of bioprosthetic valves.