Ryoko Arakaki

Potential role of omental wrapping to prevent infection after treatment for infectious thoracic aortic aneurysms

OBJECTIVES Postoperative infection control is one of the most important issues for infected aortic aneurysms, and the methods of preventing recurrent infection remain controversial. We previously reported that omental flaps could prevent or reduce the occurrence of infection after implanting an artificial aortic graft. However, the long-term outcomes of this strategy are unknown. We used imaging modalities to evaluate whether wrapping prosthetic grafts with omentum prevents postoperative graft infection over the long-term. METHODS We surgically treated 521 patients with thoracic aortic aneurysm (TAA) at our hospital between July 1995 and May 2012. Of these, 22 (3.9%) (male, n = 17; mean age, 68.2 ± 11.4 years) had infectious TAA. All infectious aneurysms were resected, all patients received in-situ grafts and 16 grafts were wrapped with omentum. We followed up all survivors annually using computed tomography. We also used angiography to investigate blood circulation in omental flaps over the long-term. RESULTS Five patients died in-hospital (operative mortality, 26.3%). The operative mortality rates of patients with and without omental wrapping were 12.5 and 50.0%, respectively (P = 0.06, NS), and the 5-year event-free survival rates were 84.6 and 33.3% (P = 0.025), respectively. Omental flaps around prosthetic grafts and their blood circulation were well-preserved over the long-term. CONCLUSIONS Wrapping implanted artificial aortic grafts with omental flaps could prevent or reduce the occurrence of subsequent infection. Furthermore, blood circulation in the flaps must be well-preserved to improve the long-term outcomes.

Management of visceral malperfusion complicated with acute type A aortic dissection

OBJECTIVES The extent of visceral malperfusion due to acute type A aortic dissection remains difficult to assess in view of the clinical signs that typically present at a late stage. We suspected that visceral malperfusion can persist after proximal aortic graft replacement despite redirecting blood flow into the true lumen. We therefore evaluated the operative outcomes of visceral malperfusion complicated with acute type A aortic dissection. METHODS Among 121 patients with acute type A aortic dissection treated at our hospital between January 2000 and December 2014, 10 (8.2%) were preoperatively complicated with visceral malperfusion. Eight of them had been treated by visceral arterial branch bypass followed by central repair, and 2 with circulatory instability had undergone central repair followed by laparotomy. RESULTS The 2 patients who underwent initial central repair required extensive intestinal resection due to necrosis and died of multiple organ failure related to visceral necrosis in hospital (hospital mortality rate, 20.0%). The ischaemic time (interval between the onset of dissection and visceral arterial revascularization) was significantly longer for patients who initially underwent central repair compared with those who were initially treated by visceral arterial revascularization. However, base excess and lactate levels did not significantly differ between the two groups. CONCLUSIONS We believe that if visceral ischaemia is severe and extensive in patients with type A aortic dissection, abdominal surgery should proceed before the aorta is surgically approached to avoid further irreversible ischaemic damage caused by circulatory arrest in organs with compromised perfusion.

Endovascular repair of intrathoracic ruptured Kommerell’s diverticulum:

A right-sided aortic arch associated with an aberrant subclavian artery is a rare anomaly. Regardless, this condition is clinically relevant because mortality is associated with rupture, morbidity results from compression of mediastinal structures, and the surgery is complex. We describe the successful surgical repair of this vascular anomaly by totally debranching the neck vessels and placing an endovascular stent-graft to exclude the ruptured Kommerell’s diverticulum.

Emergency operation for aortic dissection with ischemic stroke

A 68-year-old man lost consciousness while speaking. Computed tomography of the head revealed no hemorrhage or areas of hypodensity. Recombinant tissue plasminogen activator was administered. Neck duplex scanning showed dissecting intima of the right common carotid artery. Chest computed tomography disclosed Stanford type A aortic dissection. We performed emergency surgery because the right common carotid artery was severely stenosed. Despite 8 h of surgery due to coagulopathy, the patient was discharged without neurological deficits.

Cardiac and Aortic Reoperation for Patients withFunctional Grafts after CABG

OBJECTIVE Late cardiac and aortic reoperation after CABG is indispensable for patients with atherosclerotic disease, but reoperations are still associated with high morbidity rates. PATIENTS AND METHODS Between January 2002 and December 2010, 459 patients underwent coronary artery bypass grafting. Six patients (males; mean age, 65.0 ± 5.7 years) with previous arterial bypass grafts (mean, 2.8 ± 1.2 per patient) required reoperation for cardiac and aortic disease (3, valvular disease; 3, acute type I aortic dissection) during long-term follow-up. The mean interval between the initial operation and reoperation was 5.4 ± 2.0 years. Grafts visualized by preoperative enhanced computed tomography were harvested as pedicles and clamped for myocardial protection. The total arch or ascending aorta was replaced in three patients. The aortic valve was replaced in two patients, and the aortic and mitral valves were replaced in one. RESULTS Durations for surgery, total cardiopulmonary bypass, and cardiac ischemia were 611.5 ± 172.6, 223.2 ± 88.4, and 133.4 ± 58.0 minutes, respectively. Perioperative myocardial infarction did not develop, and all patients recovered uneventfully with no neurological deficits. CONCLUSION Bypass grafts should be preoperatively visualized and carefully exposed. Cardiac damage must be avoided during reoperation after coronary artery bypass grafting.

Prevention of Pulmonary Edema after Minimally Invasive Cardiac Surgery with Mini-Thoracotomy Using Neutrophil Elastase Inhibitor

PURPOSE Unilateral re-expansion pulmonary edema (RPE) is a rare but one of the most critical complications that may occur after re-expansion of a collapsed lung after minimally invasive cardiac surgery (MICS) with mini-thoracotomy. METHODS We performed a total of 40 consecutive patients with MICS by right mini-thoracotomy with single-lung ventilation between January 2013 and June 2016. We divided the patients into control group (n = 13) and neutrophil elastase inhibitor group (n = 27). Neutrophil elastase inhibitor group received continuous intravenous infusion of neutrophil elastase inhibitor at 0.2-0.25 mg/kg per hour from the start of anesthesia until extubation during the perioperative period. RESULTS There were no relations with operative time, cardiopulmonary bypass (CPB) time, aortic clamp time, and intraoperative water valances for postoperative mechanical ventilation support time. Compared with the neutrophil elastase inhibitor group, the control group had significantly higher initial alveolar-arterial oxygen gradient and significantly lower initial ratio of partial pressure of arterial oxygen to fraction of inspired oxygen at the intensive care unit (ICU). The control group had significantly longer postoperative mechanical ventilation support time and hospital stay compared with the neutrophil elastase inhibitor group. CONCLUSIONS Neutrophil elastase inhibitor may have beneficial effects against RPE after MICS with mini-thoracotomy.

Extended Cerebral Infarction Due to Preoperative Free-Floating Thrombus in Right Internal Carotid Artery Complicated with Acute Type-A AorticDissection

A 59-year-old man, who has cutaneous polyarteritis nodosa, presented with sudden onset of excruciating neck pain and syncope. Chest CT disclosed a Stanford type a acute aortic dissection. He rapidly lost consciousness and cardiac tamponade caused a drop in blood pressure. Emergency ascending aortic replacement proceeded under deep hypothermic circulatory arrest with antegrade selective cerebral perfusion and the cerebral blood supply was monitored throughout the procedure. However, post-operative brain CT imaging revealed extensive right hemispheric brain infarction. A large thrombus was identified in the right internal carotid artery. Whether the mechanism of brain ischemia associated with the aortic dissection was hemodynamic ischemia or thromboembolism remained unclear. We considered that thrombectomy might be needed before selective cerebral perfusion.