Kazumasa Orihashi

Indocyanine Green Angiography for Intra-operative Assessment in Vascular Surgery

OBJECTIVES Indocyanine green (ICG) angiography is used for the intra-operative assessment of the graft vessel in coronary artery bypass grafting to enable immediate revision if necessary. We report the feasibility and implications of an ICG colour imaging system, HyperEye Medical System (HEMS), in surgeries for arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) which carry risk of mesenteric ischaemia. METHODS HEMS ICG angiography was used for the intra-operative assessment of 12 ASO patients and 10 AAA patients. RESULTS In the ASO patients, HEMS angiography enabled visualisation of the graft and native artery. The fluorescent lucent region in the artery distal to the anastomosis was shown in 1 of 12 ASO patients. There was a 3-s time lag in the increase of intensity between the proximal artery and distal stenotic region. In AAA patients, HEMS angiography clearly showed the perfusion in the mesenteric arteries and intestinal wall as opaque. One AAA patient had segmental ischaemia due to thromboembolism and another one had diffuse ischaemia due to systemic malperfusion. The ischaemic region of the intestine was visualised as a fluorescent lucent area by HEMS angiography. CONCLUSION HEMS angiography can accurately assess peripheral arterial perfusion in surgical cases with ASO and AAA.

Localization of Pulmonary Nodules Using Navigation Bronchoscope and a Near-Infrared Fluorescence Thoracoscope

BACKGROUND Video-assisted thoracoscopic wedge resection of multiple small, non-visible, and nonpalpable pulmonary nodules is a clinical challenge. We propose an ultra-minimally invasive technique for localization of pulmonary nodules using the electromagnetic navigation bronchoscope (ENB)-guided transbronchial indocyanine green (ICG) injection and intraoperative fluorescence detection with a near-infrared (NIR) fluorescence thoracoscope. METHODS Fluorescence properties of ICG topically injected into the lung parenchyma were determined using a resected porcine lung. The combination of ENB-guided ICG injection and NIR fluorescence detection was tested using a live porcine model. An electromagnetic sensor integrated flexible bronchoscope was geometrically registered to the three-dimensional chest computed tomographic image data by way of a real-time electromagnetic tracking system. The ICG mixed with iopamidol was injected into the pulmonary nodules by ENB guidance; ICG fluorescence was visualized by a near-infrared (NIR) thoracoscope. RESULTS The ICG existing under 24-mm depth of inflated lung was detectable by the NIR fluorescence thoracoscope. The size of the fluorescence spot made by 0.1 mL of ICG was 10.4 ± 2.2 mm. An ICG or iopamidol spot remained at the injected point of the lung for more than 6 hours in vivo. The ICG fluorescence spot injected into the pulmonary nodule with ENB guidance was identified at the pulmonary nodule with the NIR thoracoscope. CONCLUSIONS The ENB-guided transbronchial ICG injection and intraoperative NIR thoracoscopic detection is a feasible method to localize multiple pulmonary nodules.

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

OBJECTIVES Maximal graft flow acceleration (max df/dt) determined by transit-time flowmetry (TTFM) in the diastolic phase was assessed as a possible predictor of graft failure in coronary artery bypass patients. METHODS Max df/dt was retrospectively measured in 57 in situ left internal thoracic artery grafts. TTFM data were fitted to a 5-polynomial curve, which was derived from the first-derivative curve to measure max df/dt (5-polymial max df/dt). Abnormal TTFM was defined as a mean flow of <15 ml/min, pulsatility index of >5 or diastolic filling ratio of <50%. Postoperative coronary angiography (CAG) or multidetector computed tomography (MDCT) was performed within 1 year after surgery. The grafts were classified into four groups: Normal TTFM/Patent MDCT/CAG (N/P), Normal TTFM/Failing MDCT/CAG (N/F), Abnormal TTFM/Patent MDCT/CAG (Ab-N/P) and Abnormal TTFM/Failing MDCT/CAG graft (Ab-N/F). RESULTS By TTFM, 34 grafts were normal, 5 of which were occluded on CAG, and 23 grafts were abnormal, six of which were occluded on CAG. There were significant differences in 5-polynomial max df/dt between each group pair (P < 0.05, Mann-Whitney U-test) except for the N/F:Ab-N/P group pair; especially, 5-polynomial max df/dt was significantly lower in the Ab-N/F group compared with the other groups (Ab-N/F: 0.89 ± 0.41 vs N/P: 4.74 ± 3.18, N/F: 2.23 ± 0.65, Ab-N/P: 2.70 ± 1.31 ml/s(2), P < 0.01, Mann-Whitney U-test). The sensitivity and specificity of 5-polynomial max df/dt were, respectively, 72.7 and 80.4% (cut-off value, 1.918 ml/s(2)) for all grafts and 100 and 88.2% (cut-off value, 1.273 ml/s(2)) for abnormal TTFM grafts. CONCLUSIONS The TTFM 5-polymial max df/dt value in the early diastolic phase may be a promising predictor of future graft failure.

A 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.

An educational training simulator for advanced perfusion techniques using a high-fidelity virtual patient model.

The operation of cardiopulmonary bypass procedure requires an advanced skill in both physiological and mechanical knowledge. We developed a virtual patient simulator system using a numerical cardiovascular regulation model to manage perfusion crisis. This article evaluates the ability of the new simulator to prevent perfusion crisis. It combined short-term baroreflex regulation of venous capacity, vascular resistance, heart rate, time-varying elastance of the heart, and plasma-refilling with a simple lumped parameter model of the cardiovascular system. The combination of parameters related to baroreflex regulation was calculated using clinical hemodynamic data. We examined the effect of differences in autonomous-nerve control parameter settings on changes in blood volume and hemodynamic parameters and determined the influence of the model on operation of the control arterial line flow and blood volume during the initiation and weaning from cardiopulmonary bypass. Typical blood pressure (BP) changes (hypertension, stable, and hypotension) were reproducible using a combination of four control parameters that can be estimated from changes in patient physiology, BP, and blood volume. This simulation model is a useful educational tool to learn the recognition and management skills of extracorporeal circulation. Identification method for control parameter can be applied for diagnosis of heart failure.

In Vitro Drug Sensitivity Tests to Predict Molecular Target Drug Responses in Surgically Resected Lung Cancer.

Background Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors have dramatically changed the strategy of medical treatment of lung cancer. Patients should be screened for the presence of the EGFR mutation or echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene prior to chemotherapy to predict their clinical response. The succinate dehydrogenase inhibition (SDI) test and collagen gel droplet embedded culture drug sensitivity test (CD-DST) are established in vitro drug sensitivity tests, which may predict the sensitivity of patients to cytotoxic anticancer drugs. We applied in vitro drug sensitivity tests for cyclopedic prediction of clinical responses to different molecular targeting drugs. Methods The growth inhibitory effects of erlotinib and crizotinib were confirmed for lung cancer cell lines using SDI and CD-DST. The sensitivity of 35 cases of surgically resected lung cancer to erlotinib was examined using SDI or CD-DST, and compared with EGFR mutation status. Results HCC827 (Exon19: E746-A750 del) and H3122 (EML4-ALK) cells were inhibited by lower concentrations of erlotinib and crizotinib, respectively than A549, H460, and H1975 (L858R+T790M) cells were. The viability of the surgically resected lung cancer was 60.0 ± 9.8 and 86.8 ± 13.9% in EGFR-mutants vs. wild types in the SDI (p = 0.0003). The cell viability was 33.5 ± 21.2 and 79.0 ± 18.6% in EGFR mutants vs. wild-type cases (p = 0.026) in CD-DST. Conclusions In vitro drug sensitivity evaluated by either SDI or CD-DST correlated with EGFR gene status. Therefore, SDI and CD-DST may be useful predictors of potential clinical responses to the molecular anticancer drugs, cyclopedically.

Giant Left Atrial Myxoma in a Nonagenarian

To the Editor: An independent 90-year-old man presented with progressive shortness of breath. A left atrial mass had been accidentally found on chest computed tomography at another hospital 2 years earlier. He had declined further investigation and treatment for the mass. He had been asymptomatic until 3 months earlier. He had undergone a unilateral nephrectomy for renal cell carcinoma 17 years before and had been free of recurrence after surgery. His family history was unremarkable. On physical examination, his pulse rate was 63 beats per minute, and blood pressure was 132/62 mmHg. He had bilateral leg edema and a distended jugular vein. An accentuated first heart sound without tumor plop or diastolic murmur was heard. Breath sounds were diminished. Electrocardiogram was unremarkable. Chest X-ray showed bilateral pleural effusion. Transthoracic and transesophageal echocardiography revealed a mobile and pedunculated mass in the left atrium attached to the interatrial septum (Figure 1A). The mass prolapsed into the left ventricle across the mitral valve, resulting in mitral valve obstruction and pulmonary hypertension. Tricuspid regurgitation was mild, with a pressure gradient of 53 mmHg. The inferior vena cava was 18 mm in diameter, with low respiratory change. The mitral valve appeared structurally normal, and mitral regurgitation was trivial. The left ventricle was normal in size and function. He was open to the prospect of surgical removal of the mass and accepted after obtaining the details of the surgery and discussing matters with us and his family. He underwent surgical resection of the mass (Figure 1B). Histologic examination confirmed a diagnosis of myxoma. Postoperatively, pressure gradient calculated from tricuspid regurgitation decreased to 27 mmHg. He recovered without major complication and was discharged. Figure 1 (A) Transesophageal echocardiogram showing an atrial mass prolapsing into the left ventricle. (B) The excised myxoma (3.5 × 4.5 × 7 cm).

Post-operative AICS status in completely resected lung cancer patients with pre-operative AICS abnormalities: predictive significance of disease recurrence

The AminoIndexTM Cancer Screening (AICS) system, a plasma-free amino acid (PFAA)-based multivariate discrimination index, is a blood screening test for lung cancer based on the comparison of PFAA concentrations between patients with lung cancer and healthy controls. Pre- and post-operative AICS values were compared among 72 patients who underwent curative resection for lung cancer. Post-operative changes in PFAA concentrations were also evaluated. AICS values were classified as rank A (0.0–4.9), B (5.0–7.9), or C (8.0–10.0). Rank B–C patients were evaluated for outcomes and post-operative changes in their AICS values. Twenty-three of the 44 pre-operative rank B–C patients experienced post-operative reductions in AICS rank. Only one patient experienced cancer recurrence. Post-operative changes in PFAA concentrations were associated with the risk of post-operative cancer recurrence (p = 0.001). Multivariate analysis revealed that the absence of a post-operative reduction in AICS rank independently predicted cancer recurrence (hazard ratio: 14.28; p = 0.012). The majority of patients had high pre-operative AICS values and exhibited a reduction in AICS rank after curative resection. However, the absence of a post-operative reduction in AICS rank was associated with cancer recurrence, suggesting that AICS rank may be a sensitive marker of post-operative recurrence.

Multiple coronary and cerebral aneurysms in a patient with chronic thromboangiitis

A 73-year-old man had multiple coronary aneurysms that resulted in acute myocardial infarction on the day before surgery for cerebral aneurysms. Emergent coronary angiography revealed that the lesion that caused the myocardial infarction was a distal left circumflex artery, and two huge coronary aneurysms were also found in the left circumflex artery. A two-stage treatment strategy was planned, including coronary aneurysm surgery, followed by cerebral aneurysm surgery. He underwent coronary artery aneurysmorrhaphy with closure of the ostia of the afferent and efferent arteries, and coronary artery bypass grafting with a saphenous vein graft applied to the left circumflex artery. The pathological findings suggested chronic thromboangiitis, as the inflammatory cells were observed to have infiltrated the coronary artery wall. The tissue remodeling of the aneurysmal wall indicated a positive response to tenascin C. We report a case of multiple coronary aneurysms, focusing on the pathological findings. <Learning objective: Only few reports have described coronary aneurysms related to inflammatory, atherosclerotic, and connective tissue diseases. This report describes the simultaneous occurrence of coronary and cerebral artery aneurysms, focusing on the histopathological findings. The patients histopathological examination revealed a positive response to tenascin C, which suggested tissue remodeling of the aneurysmal wall and chronic thromboangiitis.>.

Visceral malperfusion after thoracic endovascular aortic repair for type B aortic dissection in a post-abdominal aortic grafting patient

A 69-year-old woman with a history of graft replacement for abdominal aortic aneurysm developed a complicated type B aortic dissection that resulted in renal malperfusion after thoracic endovascular aortic repair (TEVAR). The primary entry tear was formed at the aortic arch and the false lumen (FL) continued to the abdominal aorta. The distal end of the FL formed a pouch-like blind alley above the suture line of the bifurcated abdominal graft. The true lumen (TL) was compressed and caused severe limb ischemia. The right renal artery (rRA) originated from the FL. The patient had initially undergone emergent axillofemoral bypass for limb malperfusion. Three weeks later, restenosis of the TL caused visceral malperfusion, and a huge thrombus formed in the FL pouch. TEVAR expanded the TL and restored visceral vascularization. However, the expanded TL compressed the thrombus in the blind alley to the rRA orifice and caused right renal malperfusion. The history of abdominal graft replacement may have increased the risk of a thrombotic event after TEVAR. Primary TEVAR may have helped prevent thrombus formation in the FL pouch. <Learning objective: This case report describes visceral arterial embolism induced by endovascular aortic repair (TEVAR) for type B aortic dissection in a patient with prior abdominal aortic grafting. A huge thrombus formed in the blind pouch of the false lumen (FL) above the graft suture line. TEVAR expanded the true lumen and the FL thrombus occluded a visceral artery with FL origin. Post-graft replacement has a risk of thrombus formation in the FL pouch and thrombus compression in visceral arteries.>.