Preoperative Clinical Features and High Pulmonary Wedge Pressure with a Discordant Pattern as Prognostic Factor in Hemodialysis Patients with Severe Aortic Valve Stenosis.

Hemodialysis (HD) is one of the important risks for the development of cardiovascular disease, including aortic valve stenosis (AS). Although aortic valve replacement (AVR) is a beneficial treatment for AS, HD patients are known to show a high rate of mortality after AVR than non-HD patients.We retrospectively studied 109 patients who underwent AVR for severe AS, 18 of which were HD patients. Survival rate after AVR, preoperative clinical data, and surgical procedure were investigated.In preoperative clinical features, left ventricular end-diastolic diameter was larger, intraventricular septum thickness (IVST) was thicker, left ventricular mass index (LVMI) was higher, left ventricular ejection fraction was lower, E/e' was higher, and pulmonary arterial wedge pressure (PAWP) was higher in the HD group than in the non-HD group. During a follow-up period of 3.2 ± 2.3 years after AVR, patients receiving HD had a worse prognosis than those without HD treatment: the 3-year survival rate after surgery in the HD group was 36.2% and that in the non-HD group was 84.9%. With regard to prognostic factors in the whole cohort, significant differences were found in IVST, LVMI, E/e', PAWP, and HD. In patients receiving HD, abnormally high PAWP for their right atrial pressure (RAP) was observed, suggesting that PAWP and RAP were discordant, and univariate analysis revealed that high PAWP was the only predictor of mortality in HD patients after surgery.Preoperative PAWP with a discordant pattern in HD patients might be an important prognostic predictor after AVR.

Dynamics of Oxidative Stress Evoked by Myocardial Ischemia Reperfusion After Off-Pump Coronary Artery Bypass Grafting Elucidated by Bilirubin Oxidation.

BACKGROUND: Revascularization therapy relieves myocardial ischemia, but can also result in ischemia-reperfusion injury caused by oxidative stress. However, the biokinetics of oxidative stress after myocardial ischemia-reperfusion are uncertain. This study aimed to evaluate the dynamics of oxidative stress after off-pump coronary artery bypass grafting (OPCAB) by measuring urinary biopyrrin levels. Biopyrrin is an oxidative metabolite of bilirubin thought to reflect oxidative stress, along with reactive nitrogen species (RNS).Methods and Results:The study included 18 patients who underwent OPCAB; patients were divided into effort angina pectoris (EAP; n=11) and unstable angina pectoris (UAP; n=7). Urinary biopyrrin and RNS levels were measured during the perioperative period (≤48 h after surgery). Biopyrrin levels transiently increased 4-12 h post-surgery (early phase), followed by a prolonged increase approximately 24-32 h post-surgery (late phase). The delayed increase in biopyrrin tended to be higher in patients with UAP, with a simultaneous increase in RNS. The patients in the UAP group had generally high pulmonary capillary wedge pressure (PCWP), although the cardiac index was within a normal range during the delay phase. CONCLUSIONS: The dynamics of biopyrrin levels revealed a biphasic pattern of oxidative stress after OPCAB. Delayed production of oxidative stress may be influenced by preoperative severity of myocardial ischemia and delayed RNS production.

Quantitative assessment technique of HyperEye medical system angiography for coronary artery bypass grafting.

PURPOSE: The HyperEye Medical System (HEMS) uses indocyanine green (ICG) to visualize blood vessels in coronary artery bypass grafting (CABG). We performed quantitative HEMS assessment to detect grafts at risk of occlusion. METHODS: We assessed the HEMS angiograms of 177 grafts from 69 patients who underwent CABG and compared the results with those of fluoroscopic coronary angiography, by measuring the increasing rate of ICG intensity, average acceleration value, and time to peak luminance intensity. RESULTS: Grafts in the patent and failed groups showed significant differences in their increasing rate of intensity and average acceleration value. The average accelerations value of ICG intensity of internal thoracic artery (ITA) and saphenous vein (SV) grafts were 112.3 and 144.9 intensity/s2 in the patent group, and 71.0 and 91.8 intensity/s2 in the failed group. The time to peak luminance intensity was 1.7 and 1.4 s in the patent group and 2.3 and 1.9 s in the failed group; these values were not significantly different. CONCLUSION: Significant reductions in the ICG intensity rate and average acceleration value can occur in failed grafts. Therefore, quantifiable changes in ICG intensity may help detect minute changes in blood flow.

Influence of vessel stenosis on indocyanine green fluorescence intensity assessed by near-infrared fluorescence angiography.

PURPOSE: Although useful for visualizing blood flow during revascularization surgery, the permeability of near-infrared fluorescence (NIR) angiography using indocyanine green (ICG) does not allow for vessel stenosis visualization. We hypothesized that changes in ICG fluorescence intensity reflect vessel stenosis, and evaluated the influence of stenosis on blood flow by ex vivo experimentation. METHODS: The vessel stenosis model comprised a silicon tube, a graft occluder, and artificial blood. During near-infrared angiography, the fluorescense intensity was calculated during pre- and post-stenosis of an artificial circuit, using a NIR angiography. We measured the maximum fluorescence intensity and the time to maximum fluorescence intensity. RESULTS: Severe stenosis (≥75%) attenuated the increase in ICG fluorescence intensity in the tube significantly, pre- and post-stenosis. The time to maximum fluorescence intensity did not differ between sites pre- and post-stenosis, irrespective of stenosis severity. CONCLUSION: Stenosis affected the ICG fluorescence intensity through the vessel. Thus, quantitative analysis using NIR angiography may detect severe vessel stenosis (≥75%), and the extinction curve of indocyanine fluorescence intensity may support the evaluation of blood flow. The absence of differences in the time to maximum fluorescence intensity for degrees of stenosis might suggest a limitation of previous conventional qualitative assessments.

[Ascending Aortic Thrombus Recognized by Acute Brachial Arterial Occlusion].

We report a case of ascending aortic thrombus with acute arterial occlusion of the brachial artery. A 49-year-old woman had sudden pain in her right arm due to acute occlusion of the right brachial artery. Contrast-enhanced computed tomography and echocardiography revealed a large mobile thrombus in the ascending aorta, which prompted surgical intervention. The thrombi were removed via aortotomy under circulatory arrest. Trans-esophageal echocardiography was useful for watching a potential detachment of the thrombus in the aorta during surgical manipulations or systemic perfusion. Despite no evidence of either inherited or acquired thrombotic predisposition, thrombosis in the right atrium and deep veins of the lower extremities was found postoperatively. Since antiplatelet and anticoagulant therapy was started, she has suffered from no thrombotic event.

Maximal blood flow acceleration analysis in the early diastolic phase for aortocoronary artery bypass grafts: a new transit-time flow measurement predictor of graft failure following coronary artery bypass grafting.

PURPOSE: Maximal graft flow acceleration (max df/dt) determined using transit-time flowmetry (TTFM) in the diastolic phase was assessed as a potential predictor of graft failure for aortocoronary artery (AC) bypass grafts in coronary artery bypass patients. METHODS: Max df/dt was retrospectively measured in 114 aortocoronary artery bypass grafts. TTFM data were fitted to a 9-polynomial curve, which was derived from the first-derivative curve, to measure max df/dt (9-polynomial max df/dt). Abnormal TTFM was defined as a mean flow of <15 ml/min, a pulsatility index of >5 or a diastolic filling ratio of <50 %. Postoperative assessments were routinely performed by coronary artery angiography (CAG) at 1 year after surgery. RESULTS: Using TTFM, 68 grafts were normal, 4 of which were failing on CAG, and 46 grafts were abnormal, 21 of which were failing on CAG. 9-polynomial max df/dt was significantly lower in abnormal TTFM/failing by the CAG group compared with abnormal TTFM/patent by the CAG group (1.08 ± 0.89 vs. 2.05 ± 1.51 ml/s(2), respectively; P < 0.01, Mann-Whitney U test, Holm adjustment). CONCLUSIONS: TTFM 9-polynomial max df/dt in the early diastolic phase may be a promising predictor of future graft failure for AC bypass grafts, particularly in abnormal TTFM grafts.

Efficacy of intraoperative HyperEye Medical System angiography for coronary artery bypass grafting.

PURPOSE: When performing coronary artery bypass grafting, anastomotic insufficiency needs to be detected during surgery. We developed a novel indocyanine green angiography system, the HyperEye Medical System (HEMS), which enables color imaging of the bypass flow. This article described the accuracy of HEMS angiography for predicting graft patency. METHODS: A total of 144 grafts in 40 coronary artery bypass grafting patients were assessed by HEMS angiography, a transit time flowmeter (TTF) during surgery and fluoroscopic angiography 1 year after the operation. RESULTS: HEMS angiography showed normal flow in 133 grafts, but abnormal flow in 11. Fluoroscopic angiography showed that 130 of the 133 "normal" grafts were patent (negative predictive value: 97.7%) and that nine of the 11 "abnormal" grafts were occluded (positive predictive value: 81.8%). As a result, 134 grafts were assessed as normal and 10 as abnormal by TTF. Fluoroscopic angiography showed that 124 of these 134 grafts were patent (negative predictive value: 92.5%), whereas two of the 10 grafts were occluded (positive predictive value: 20.0%). For the 127 grafts with compatible results by the HEMS and TTF assessments, the positive and negative predictive values were 100 and 97.6%, respectively. CONCLUSION: HEMS angiography of a bypass graft may provide an accurate prediction of the graft patency after surgery.

[Operative Results of Total Arch Replacement with Arch First Technique using a Trifurcated Graft].

In aortic arch surgery, we reconstruct branches before opening the arch to avoid cerebral embolism of the debris derived from the aortic wall. We made a trifurcated graft for branch reconstruction using 10 mm and 8 mm polyester grafts. Cardiopulmonary bypass started under right axillary perfusion and venous drainage through the right atrium. While cooling, the left subclavian artery was clamped and anastomosed to the end of the trifurcated graft. Then the ascending aorta was cross-clamped and cardioplegic solution was infused. At 25 degrees centigrade of the tympanic temperature, the left carotid artery is clamped and anastomosed to the branch of the trifurcated graft with or without perfusion into the left carotid artery. Subsequently the brachiocephalic artery was reconstructed in the same manner. After antegrade cerebral perfusion was established through the trifurcated graft via right axillary perfusion, distal anastomosis of the aortic arch was done with the open distal technique. Graft-graft anastomosis was followed to reperfuse the lower half of the body. Finally proximal anastomosis was performed to complete total arch replacement. Forty-four patients underwent total arch replacement in this technique. In-hospital mortality was 4.5%. Cerebral infarction occurred in 4.5% of the patients probably due to embolization of the debris derived from the branches of the aortic arch.

Cardiac calcified amorphous tumor stuck in the aortic valve that mimicked a chameleon's tongue: report of a case.

A calcified amorphous tumor (CAT) is a rare intracardiac mass that carries a risk of embolism. We herein present the case of a club-shaped CAT that originated from the calcified mitral annulus. Echocardiography indicated a pendular motion of the mass and repeated entrapment by a stenotic aortic valve that was sustained for several beats, mimicking a chameleon's tongue. An emergency operation was performed because of the risk of embolism, as well as potential progression of cardiac failure due to worsening aortic valve stenosis. The histological findings were consistent with the diagnosis of a CAT. This report describes a case of an intracardiac tumor that showed unique motion like a chameleon's tongue.

[Pacemaker infection in a child; report of a case].

In the treatment for pacemaker infection, removal of infected devices and intensive antibiotics therapy are in principle and new devices should be implanted apart from the infected site. However, there are some problems in the case of children:it is not easy to remove infected devices because epicardial leads are often used for them. If endocardial leads are chosen as a new system, extension of the lead would be concerned with their growth. We report a pediatric case of infection of pacemaker using epicardial leads. It was difficult to cure infection by repeated local treatment leaving epicardial leads and antibiotics therapy was obliged to continue for 9 years to keep infection under control. After growing up, we implanted endocardial leads for her and removed infected devices to cure infection completely.

Development of a new selective coronary perfusion cannula.

The two most common types of coronary perfusion cannulae currently being used are the "balloon type", with a balloon at the tip, and the "fenestrated type", which has holes along the side near the tip. However, on occasion an unusually high perfusion pressure or a considerable amount of leakage is encountered during infusion of the cardioplegic solution. We have examined the properties of a newly developed Kochi Medical School (KMS)-type cannula and compared these to the properties of the balloon-type and fenestrated-type cannulae in an ex vivo experimental model that contains ostia of 4, 3, or 2 mm in diameter. Ejected flow velocity, circuit pressure, and the amount of leakage were measured at an infusion rate of 100 and 200 mL/min, with the latter two parameters measured under the counterpressure of 0 and 50 cmH2O to examine the influence of coronary vascular resistance. Without counterpressure, the balloon type presented with the highest flow velocity (263 cm/s at 200 mL/min) and perfusion pressure (64 mmHg at 200 mL/min) but without leakage. The fenestrated type yielded a considerable amount of leakage (40 % at an ostium size of 2 mm). The KMS type showed a lower flow velocity and circuit pressure with less leakage. Under 50 cmH2O counterpressure, however, only the KMS-type cannula could inject the water to any ostium size at both flow rates. These results suggest that the concept of the KMS-type cannula may be advantageous to achieving a secure infusion to a diseased coronary ostium.

Intraoperative continuous hemodiafiltration with selective venous drainage of ischemic limbs.

We report two cases of acute limb ischemia with threatened myonephropathic metabolic syndrome (MNMS) in which continuous hemodiafiltration (CHDF) was started before revascularization with selective drainage from the clamped femoral vein of ischemic limb and return of processed blood into the contralateral femoral vein. It was aimed to optimise the removal of metabolites which were produced by myolysis following reperfusion as well as to minimize the deviation of metabolites into the systemic circulation. Both cases had uneventful postoperative course without MNMS and the limbs were salvaged.

[Introduction, designs and assessment of a suture set for standard cardiovascular surgery].

A packing system for threads and needles has been introduced with the aim of efficient operations in the field of cardiovascular surgery. To provide competent and safe surgery to patients, a suture set was developed according to the standard cardiovascular surgery procedure with cooperation between doctors and nurses at Kochi University Hospital. This suture set was introduced to all surgeries for adults conducted under cardiopulmonary bypass. Herein, we describe problems before the introduction, the process of the introduction, and designs of the suture set. In addition, we assessed the present condition since the introduction of this suture set. Many positive opinions were obtained from both doctors and nurses, and the suture set thus yielded a satisfactory assessment. Psychological stability and safety provided by the suture set may lead not only to cost reduction but also to an increased level of surgery as a whole. In addition, it may now be possible to provide simpler and more efficient cardiovascular surgery with this set. This suture set will serve as a useful model for thread and needle packing systems to be developed at various facilities in the future.

Intake of dissolved organic matter from deep seawater inhibits atherosclerosis progression.

Dissolved organic matter (DOM) in seawater can be defined as the fraction of organic matter that passes through a filter of sub micron pore size. In this study, we have examined the effect of DOM of deep seawater (DSW) from Pacific Ocean on platelet aggregation and atherosclerosis progression. DSW was passed through a series of filters and then through an Octadecyl C18 filter; the retained substance in ethanol was designated as C18 extractable DOM (C18-DOM). Our studies showed that C18-DOM treatment inhibited platelet aggregation, P-selectin expression and activity of COX-1 significantly. C18-DOM increased the expression of anti-atherogenic molecule namely heme oxygenase-1 in endothelial cells and all these data showed that C18-DOM is exhibiting aspirin-like effects. Moreover our in vivo studies showed that C18-DOM feeding slowed remarkably the progression of atherosclerosis. Our study demonstrated a novel biological effect of oceanic DOM, which has several important implications, including a possible therapeutic strategy for atherosclerosis.

A Case of Anastomotic Stenosis of a Peripheral Arterial Bypass Graft Undetected in Indocyanine Green Angiography.

We report the case of a 75-year-old man who underwent right femoral-popliteal bypass surgery. Anastomotic stenosis was overlooked in indocyanine green (ICG) angiography due to opacification on the bypass graft. X-ray angiography revealed slit-shaped stenosis in the distal graft anastomosis that required revision. Although blood flow may be maintained despite of anastomotic stenosis, small decreases in blood flow cannot be detected in ICG angiography. We describe and discuss the pitfalls of qualitative graft assessment using ICG angiography, and compare ICG fluorescence luminance intensity between primary and revised grafts.

Pathological investigation of graft-related oesophageal fistula.

Oesophageal fistulae after thoracic endovascular aneurysm repair (TEVAR) for thoracic aortic aneurysm (TAA) have been reported, although the causes are unknown. One hypothesis is that the structural configuration of the aortic aneurysm, as it protrudes towards the oesophagus, may affect oesophageal fistula formation. The pathological findings of an oesophageal fistula following TEVAR are reviewed here. This report presents the case of a 68-year-old man with a stent graft-related oesophageal fistula after TEVAR for TAA. The oesophageal fistula suddenly appeared on the 11th day after TEVAR, and oesophagectomy was performed, without stent graft extirpation. The pathological findings showed neutrophil infiltration from the adventitia to the mucosa and congestion in the capillaries of the oesophageal wall around the site of penetration and no bacterial infection. There have been reports with logical hypotheses about the causes of stent graft-related oesophageal fistulae. Our pathological findings support the theory that pressure necrosis or ischaemic insult by physical compression of a rigid thrombosed aneurysm may result in fistula formation. For descending aortic aneurysms that protrude toward the oesophagus, caution must be exercised to prevent oesophageal fistula formation after TEVAR.

Iatrogenic subintimal aortic dissection that disappeared without a trace.

A case of an unusual iatrogenic aortic dissection is reported. A 77-year-old male patient in shock status due to acute type A aortic dissection underwent emergency surgery. Systemic perfusion was started via the femoral artery, but another dissection appeared in the descending aorta detected by transoesophageal echocardiography. However, the flap was unusually thin, and there was no change in the pre-existing thrombosed false lumen. These findings suggested subintimal development of dissection. After systemic perfusion was promptly switched to antegrade perfusion, the new dissection could no longer be detected. Since there was no malperfusion or aortic rupture, the ascending aorta was repaired. His postoperative course was uneventful, and there were no significant complications. Unless the aorta is carefully observed at the right time during the operation, such vanishing aortic dissection may be missed and potentially result in 'organ damage of unknown cause'.

Intima migration from the iliac artery to a debranched graft after thoracic endovascular aortic repair.

An 84-year-old woman underwent single-debranched thoracic endovascular aortic repair for aortic aneurysm. A few hours later, malperfusion of the left upper extremity occurred. Surgical exploration revealed a tubular-shaped intima packed in the debranched graft. As computed tomography showed localized dissection in the right external iliac artery probably due to access route injury, the intima roll was thought to have migrated from the iliac artery. This extremely rare case is described in detail with a discussion of the potential mechanism.

Triple ultrasonography for iatrogenic acute aortic dissection caused by axillary arterial perfusion.

Iatrogenic aortic dissection caused by axillary arterial cannulation or perfusion becomes a fatal complication of cardiopulmonary bypass when surgeons do not recognize it in the surgical field of view immediately during surgery. Therefore, we routinely monitor the aorta using 'triple ultrasonography' during cardiovascular surgery. An 85-year-old woman underwent partial arch replacement for chronic type A aortic dissection. During cardiopulmonary bypass, acute aortic dissection was observed in the aortic arch from the right axillary artery on real-time transoesophageal echocardiography. Epiaortic and neck surface ultrasonography detected malperfusion of the carotid artery. During femoral arterial perfusion, the patient was rescued with partial aortic replacement. Axillary artery cannulation is useful for cardiopulmonary bypass but confers a risk of iatrogenic aortic dissection that cannot be confirmed by surgeons surgically. The transoesophageal echocardiography can guard the aorta while systemic perfusion is initiated. Furthermore, epiaortic and neck surface echography can be incorporated to transoesophageal echocardiography. Triple ultrasonography allows for the detection of iatrogenic aortic dissection.