Usefulness of Motor Evoked Potential Measurement and Analysis of Risk Factors for Spinal Cord Ischaemia from 300 Cases of Thoracic Endovascular Aortic Repair.

OBJECTIVE: This study investigated the usefulness of motor evoked potentials (MEPs) for intra-operative monitoring to detect the risk of spinal cord ischaemia (SCI) during thoracic endovascular aortic repair (TEVAR). Risk factors for SCI in TEVAR were also analysed. METHODS: Among 330 TEVARs performed from February 2009 to October 2018, 300 patients underwent intra-operative MEP monitoring. SCI risk groups were extracted based on MEP amplitude changes using a cutoff value of 50%. When the amplitude decreased to < 50% of the pre-operative value, intra-operative mean arterial pressure (MAP) was increased by about 20 mmHg using noradrenaline, whereas MAP was usually controlled to about 80 mmHg during surgery. Other efforts were also made to increase MEP amplitude by increasing cardiac output, correcting anaemia, and finishing the surgery promptly. Based on MEP amplitude data, SCI risk groups were extracted and risk factors for SCI in TEVAR were analysed. RESULTS: A total of 283 non-SCI risk patients and 17 SCI risk patients by MEP monitoring were extracted; only 1.0% developed immediate paraplegia and none developed delayed paraplegia. Bivariable analysis showed significant differences in chronic kidney disease, haemodialysis, artery of Adamkiewicz closure, and stent graft (SG) covered length ≥ 8 vertebral bodies. Logistic regression analysis showed hyperlipidaemia (odds ratio [OR] 3.55, 95% confidence interval [CI] 1.08 - 11.67; p = .037), SG covered length ≥ 8 vertebral bodies (OR 1.35, 95% CI 1.02 - 1.78; p = .034), and haemodialysis (OR 27.78, 95% CI 6.02 - 128.22; p < .001) were the most influential risk factors for SCI in TEVAR. CONCLUSION: MEPs might be a useful monitoring tool to predict SCI in TEVAR. In addition, hyperlipidaemia, SG covered length ≥ 8 vertebral bodies, and haemodialysis represent key risk factors for SCI during TEVAR.

[Rupture of Artificial Blood Vessel by a Sternal Wire:Report of a Case].

Formation of a pseudoaneurysm due to blood leakage from the anastomotic site of the vascular graft in large-diameter vessels is often seen, but formation of a pseudoaneurysm from the non-anastomotic site is extremely rare. A 68-year-old woman presented with a history of double valve replacement for combined valvular disease at 37 years old and hemiarch replacement for thoracic aortic dilatation at 65 years old. She visited the emergency room with a 2-week history of chest pain. Contrast-enhanced computed tomography (CT) revealed a 5-cm-diameter pseudoaneurysm and extravasation from the ascending aorta, so emergency surgery was performed. Around the ascending aorta area, we confirmed bleeding from a 5-mm dehiscence in the non-anastomotic part of the graft prosthesis, so hemostasis was performed with a cross-stitch mattress suture over a felt strip. Initially, the cause of the pseudoaneurysm was unknown, but re-examination of CT images from after the previous hemiarch replacement confirmed contact between the sternal wire and graft prosthesis. The wire was thus considered to have caused damage and bleeding. The patient was discharged from the hospital with a good postoperative course and is being followed-up in the outpatient department.

[Pulmonary Artery Transection in Surgery for Coronary Artery Fistula].

Coronary artery fistula is a rare abnormality in the communication between a coronary artery and any of the cardiac chambers or major vessels. At present, there is no standard surgical treatment and the most appropriate method is selected on a case-by-case basis. We report one case of coronary artery fistulae in which pulmonary artery transection was required around the left main trunk (LMT). A 62-year-old man who had coronary artery fistulae with an aneurysm which increased from 12 mm to 16 mm in a two-year span. The fistula was located adjacent to the LMT. A complete aneurysm excision under cardiopulmonary bypass was performed, which required pulmonary artery transection. No postoperative complications occurred. Postoperative coronary computed tomography scan showed intact coronary arteries and complete aneurysm removal.

Simultaneous upper and lower body perfusion using hypothermia during thoracoabdominal aortic surgery.

BACKGROUND: In open thoracoabdominal aortic aneurysm (TAAA) repair, we have been performing vascular reconstruction under moderate to deep hypothermia and assisted circulation using simultaneous upper and lower body perfusion. This method is effective for protecting the spinal cord and the brain, heart, and abdominal organs and for avoiding lung damage. METHODS: TAAA repair was performed under hypothermia at 20-28 °C in 18 cases (Crawford type I in 0 cases, type II in 5, type III in 3, type IV in 4, and Safi V in 6) between October 2014 and January 2023. Cardiopulmonary bypass was conducted by combined upper and lower body perfusion, with perfusion both via the femoral artery and either transapically or via the descending aorta or the left brachial artery. RESULTS: The ischemic time for the artery of Adamkiewicz and the main segmental arteries was 40-124 min (75 ± 33 min). No spinal cord ischemic injury or brain or heart complications occurred. One patient with postoperative right renal artery occlusion and one with an infected aneurysm required tracheostomy, but the intubation time for the other 16 was 32 ± 33 h. The duration of postoperative intensive care unit stay was 6.5 ± 6.2 days, the length of hospital stay was 29 ± 15 days, and no in-hospital deaths occurred. CONCLUSIONS: Simultaneous upper and lower body perfusion under moderate to deep hypothermia during thoracoabdominal aortic surgery may avoid not only spinal cord injury, but also cardiac and brain complications.

Mechanism of Increased Spinal Cord Blood Flow due to Noradrenaline Administration Using Vascular Resistance: An Experimental Study Using a Canine Model.

Background: During thoracoabdominal aortic surgery, the spinal cord is placed under ischemic conditions. Elevation of systemic blood pressure is thus recommended as a method of increasing the blood supply from collateral networks. This study examined the mechanisms by which noradrenaline administration increases spinal cord blood flow (SCBF) by elevating systemic blood pressure. Methods: In beagles (n = 7), the thoracoabdominal aorta and L2-L7 spinal cord segmental arteries (SAs) were exposed and a distal perfusion bypass was created to simulate clinical practice. SCBF was measured by laser flowmetry at the L5 dura mater and spinal cord perfusion pressure (SCPP) was measured inside the clamped aorta. The six pairs of SAs from L2 to L7 were clamped, and mean systemic blood pressure (mSBP), SCBF, and SCPP were measured before and after clamping and after starting continuous infusion of noradrenaline at 0.5 µg/kg/min. Rates of change in systemic vascular resistance (SVR) and spinal cord vascular resistance (SCVR) were calculated from the measured values. Results: With no SA clamping (control), the rate of increase in SCVR was 0.74 times the rate of increase in SVR (y = 0.2 + 0.74x, r = 0.889, r2 = 0.789; P < 0.01). When all six pairs of SAs were clamped, a weak correlation was evident between rate of change in SCVR and rate of change in SVR, and the rate of increase in SCVR was lower than the rate of increase in SVR (y = 0.39 + 0.07x, r = 0.209, r2 = 0.039; P < 0.01). When all six pairs of SAs were clamped in the absence of distal perfusion, a weak correlation was also evident between rate of change in SCVR and rate of change in SVR, and the rate of increase in SCVR was lower than the rate of increase in SVR (y = 0.19 + 0.08x, r = 0.379, r2 = 0.144; P < 0.01). Conclusions: The rate of increase in SCVR induced by noradrenaline administration was lower than the rate of increase in SVR in the control group with no spinal cord SA clamping and in both experimental groups with clamped SAs (with and without distal perfusion), creating an environment conducive to spinal cord flow distribution.

Three Arterial Ruptures in a Patient with Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF-1) is a rare disease known to cause vascular fragility. A case of a 59-year-old man with NF who had ruptures in three different arteries within a month is presented. The first rupture occurred in the right renal artery and was treated using a stent graft and embolization coils. The second and third ruptures occurred in an artery that had been compressed by a hematoma formed during the first bleed; both were embolized. In patients with NF-1, blood vessel fragility must be considered in treatment selection, especially when performing surgery or other invasive procedures near the great vessels.

Open Repair for Patent Ductus Arteriosus Aneurysm in an Adult.

Ductus arteriosus aneurysm (DAA) is rarely encountered in adults. There have been several hypotheses regarding its origin and potential indications for intervention in asymptomatic cases. If left untreated, rupture, compression of surrounding organs, and serious complications due to thromboembolism may occur, and aggressive surgical intervention appears desirable for patients who can tolerate surgery. We report a case involving a 30-mm, saccular, patent DAA that was incidentally discovered in a 49-year-old man on computed tomography. Open repair was performed by femorofemoral bypass assistance, which allowed decompression of the aorta and aneurysm and successful closure of the aortic and pulmonary artery ends.

Survival and cause of death after aortic arch aneurysm repair.

BACKGROUND: This study aimed to identify differences in prognosis, causes of death, and outcomes between open and endovascular repair for aortic arch aneurysms. METHODS: We retrospectively analyzed the survival status and causes of death determined from the medical records of 124 consecutive elderly patients (age>70 years) with aortic arch aneurysms that were treated between 2010 and 2018 at our hospital. Forty patients (male, N.=30; mean age, 76 years) underwent open repair and 84 (male, N.=68; mean age, 78 years) underwent endovascular repair. RESULTS: Early postoperative complications (10.0% vs. 6.3%; P=0.4) and rates of in-hospital death (2.5% vs. 6.3%; P=0.2) did not significantly differ between open and endovascular repair. Cumulative long-term and event free survival rates at eight years were similar in both groups (78.7% vs. 66.3%, P=0.1 and 66.6% vs. 58.4%; P=0.4, respectively). The causes of death at follow-up after endovascular repair comprised malignancies in 11 (52.4%) patients and cardiopulmonary and cerebral events unrelated to aortic aneurysms in 10 (47.6%). CONCLUSIONS: Early and late outcomes did not statistically differ after both procedures. However, the prevalence of cancer-related death occurring late after arch repair was significantly higher after endovascular repair. The most important observation from this series was that significantly more patients died of malignant disease during follow-up after endovascular repair than open repair.

Transapical aortic perfusion using a deep hypothermic procedure during descending thoracic or thoracoabdominal aortic surgery.

BACKGROUND: In descending thoracic aortic aneurysm (DTAA) or thoracoabdominal aortic aneurysm (TAAA) surgery, though proximal anastomosis using deep hypothermic circulatory arrest (DHCA) is often selected, there are issues surrounding brain and heart protection. In this study, the usefulness of concomitant upper body perfusion via transapical aortic cannulation during deep hypothermic surgery was examined. METHODS: Between October 2014 and May 2019, 5 patients (Crawford extent II chronic dissection, N.=3; extent IV aneurysms, N.=1; DTAA, N.=1) underwent DTAA/TAAA repair under deep hypothermia using transapical aortic perfusion. A proximal anastomosis and artery of Adamkiewicz (AKA) reconstruction were performed under continuous perfusion of the upper and lower body at 20 °C. RESULTS: The time from aortic cross-clamping to proximal anastomosis was 69±33 minutes, and it took 86±47 minutes to AKA reperfusion. There was no spinal cord ischemic injury or brain or heart complications. One patient required tracheostomy, and the average postoperative intubation time for the other patients was 57±52 hours. All patients were discharged, and the average postoperative hospital stay was 25.6±8.1 days. CONCLUSIONS: Concomitant upper body perfusion by the transapical aortic approach contributes to avoidance of brain and heart complications and maintaining spinal cord circulation under deep hypothermic DTAA/TAAA surgery.

Direct Monitoring of Reconstructed Segmental Arterial Pressure during Deep Hypothermic Thoracoabdominal Aortic Aneurysm Surgery.

Deep hypothermia in thoracoabdominal aortic aneurysm operations is considered extremely useful for ensuring sufficient time to reconstruct the segmental arteries feeding the spinal cord. However, because the amplitude of motor evoked potentials (MEPs) decrease or disappear during deep hypothermia, feasible methods for assessing spinal cord circulation have not yet been reported. Performing additional segmental arterial reconstructions that rely on MEPs is also impractical. In the present case, to ascertain spinal cord circulation under deep hypothermia, we intraoperatively measured the reconstructed segmental arterial pressure in real time and investigated whether sufficient spinal cord blood flow had been attained.

Direct reopening of the occluded hepatic veins of Budd-Chiari syndrome: verification of our operative method by the perioperative course of esophageal varices.

OBJECTIVE: A total of 69 patients with Budd-Chiari syndrome (BCS) were operated by direct approach under cardiopulmonary bypass (CPB). To assess the operative procedure, the perioperative course of esophageal varices (EVs) was evaluated. PATIENTS AND METHODS: Of the 69 patients, 59 (22 females) were enrolled in this study because they had complete follow-up data for endoscopic evaluation of EVs. Their mean age was 46.3 ± 13.0 years (range 21-73.3 years). EVs were found in 52 patients. Under partial cardiopulmonary bypass, the inferior vena cava (IVC) was incised. The obstruction of the IVC was excised, and the occluded hepatic veins were reopened. The incised IVC was reconstructed with an auto-pericardial patch. RESULTS: Postoperatively, the repaired IVC was patent in all patients. The average number of patent hepatic veins (HVs) increased from 1.23 ± 0.81 to 2.21 ± 0.97/patient. The pressure gradient between the IVC and right atrium (RA) decreased from 12.4 ± 5.52 to 4.46 ± 3.21 mmHg. The indocyanine green clearance test (ICG) at 15 min decreased from 31.57 ± 17.44 to 22.27 ± 15.23%. EVs had disappeared in 13 patients at discharge and in 6 patients at late postoperative follow-up. CONCLUSION: Our operative procedure for BCS is useful for decreasing portal pressure, which is reflected by disappearance of EVs. Therefore, the high risk of EV rupture could be avoided by reopening the occluded HVs.

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.

Transapical aortic perfusion using a deep hypothermic procedure to prevent dissecting lung injury during re-do thoracoabdominal aortic aneurysm surgery.

BACKGROUND: Avoiding various complications is a challenge during re-do thoracoabdominal aneurysm surgery. CASE PRESENTATION: A 56-year-old man had undergone surgery for type I aortic dissection four times. The residual thoracoabdominal aortic aneurysm that had severe adhesions to lung parenchyma was resected. Since the proximal anastomotic site was buried in lung parenchyma, deep hypothermia was essential to avoid lung dissection and to protect the spinal cord during the proximal anastomosis. The deep hypothermia was induced with bilateral infusion of cardiopulmonary bypass by femoral artery cannulation for the lower body and by transapical cannulation for the upper body because of easy access. There was no hemorrhagic tendency after deep hypothermic bypass. The patient was discharged uneventfully. CONCLUSIONS: For upper body perfusion, transapical aortic cannulation was a simple and effective procedure during left thoracotomy.

Long-term Treatment of Teicoplanin for Methicillin-resistant Staphylococcus aureus Sternal Osteomyelitis with Renal Impairment: A Case of High Teicoplanin Trough Levels Maintained by Therapeutic Drug Monitoring.

Teicoplanin, a glycopeptide antibiotic for methicillin-resistant Staphylococcus aureus, is recommended for therapeutic drug monitoring during treatment. Maintaining a high trough range of teicoplanin is also recommended for severe infectious disease. However, the optimal dose and interval of treatment for severe renal impairment is unknown. We report a 79-year-old man who received long-term teicoplanin treatment for methicillin-resistant Staphylococcus aureus bacteremia due to postoperative sternal osteomyelitis with renal impairment. Plasma teicoplanin trough levels were maintained at a high range (20-30 µg/mL). Although the patient required long-term teicoplanin treatment, a further decline in renal function was not observed, and blood culture remained negative after the start of treatment. Teicoplanin treatment that is maintained at a high trough level by therapeutic drug monitoring might be beneficial for severe methicillin-resistant Staphylococcus aureus infection accompanied by renal impairment.

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.

Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

OBJECTIVE: During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. METHODS: In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. RESULTS: Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P < .01) and without (r = 0.834, P < .01) distal aortic perfusion. In addition, we observed significant correlations between spinal cord perfusion pressure and spinal cord blood flow with and without distal perfusion (r = 0.803, P < .001 and r = 0.832, P < .01, respectively), and between mean systemic blood pressure and spinal cord perfusion pressure with and without distal perfusion (r = 0.898, P < .001 and r = 0.837, P < .001, respectively). The spinal cord was perfused from the collateral network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. CONCLUSIONS: Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring perioperative spinal cord blood flow.

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.

Detection of active bleeding from gastric antral vascular ectasia by capsule endoscopy.

Gastric antral vascular ectasia (GAVE) has been recognized as one of the important causes of occult and obscure gastrointestinal bleeding. The diagnosis is typically made based on the characteristic endoscopic features, including longitudinal row of flat, reddish stripes radiating from the pylorus into the antrum that resemble the stripes on a watermelon. These appearances, however, can easily be misinterpreted as moderate to severe gastritis. Although it is believed that capsule endoscopy (CE) is not helpful for the study of the stomach with its large lumen, GAVE can be more likely to be detected at CE rather than conventional endoscopy. CE can be regarded as "physiologic" endoscopy, without the need for gastric inflation and subsequent compression of the vasculature. The blood flow of the ecstatic vessels may be diminished in an inflated stomach. Therefore, GAVE may be prominent in CE. We herein describe a case of active bleeding from GAVE detected by CE and would like to emphasize a possibility that CE can improve diagnostic yields for GAVE.

Determination of oxidative stress and cardiac dysfunction after ischemia/reperfusion injury in isolated rat hearts.

BACKGROUND: Oxidative stress due to reactive oxygen species (ROS) is thought to play a considerable role in ischemia/reperfusion (I/R) injury that impairs cardiac function. The present study examined oxidative damage in I/R injury and investigated the correlation between oxidative stress and impaired cardiac function after I/R injury of the isolated rat heart. METHODS: Hearts isolated from male Sprague-Dawley rats were mounted on a Langendorff apparatus. Hearts arrested using St. Thomas cardioplegic solution and then they were reperfused. The hearts were divided into three groups depending on the frequency (0-2) of I/R. After I/R, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), positive maximum left ventricular developing pressure (max LV dP/dt) and coronary flow (CF) were measured. Creatine kinase (CK) was measured in the coronary effluent and 8-hydroxy-2'deoxyguanosine (8OHdG), a marker of oxidative DNA damage, was measured. Adenosine triphosphate (ATP) was measured from frozen myocardial tissue after experiment. RESULTS: We immunohistochemically demonstrated and quantified levels of 8-OHdG after I/R injury of the heart. The frequency of I/R injury and cardiac dysfunction significantly and negatively correlated. The ATP products were similar among the three groups. The incidence of ventricular arrhythmias was not by affected oxidative stress. CONCLUSION: The frequency of I/R injury had more of an effect on 8-OHdG products and on impaired cardiac function with less myocyte damage than ischemic duration within 30 minutes of ischemia.

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.