Blood flow evaluation of reconstructed gastric tube in esophageal surgery using near-infrared imaging and retrospective time-intensity curve analysis.

PURPOSE: Near-infrared fluorescence imaging using indocyanine green (ICG-NIFI) can visualize a blood flow in reconstructed gastric tube; however, it depends on surgeon's visual assessment. The aim of this study was to re-analyze the ICG-NIFI data by an evaluator independent from the surgeon and feasibility of creating the time-intensity curve (TIC). METHODS: We retrospectively reviewed 97 patients who underwent esophageal surgery with gastric tube reconstruction between January 2017 and November 2022. From the stored ICG videos, fluorescence intensity was examined in the four regions of interest (ROIs), which was set around the planned anastomosis site on the elevated gastric tube. After creation the TICs using the OpenCV library, we measured the intensity starting point and time constant and assessed the correlation between the anastomotic leakage. RESULTS: Postoperative leakage occurred for 12 patients. The leakage group had significantly lack of blood flow continuity between the right and left gastroepiploic arteries (75.0% vs. 22.4%; P < 0.001) and tended to have slower ICG visualization time assessed by the surgeon's eyes (40 vs. 32 s; P = 0.066). TIC could create in 65 cases. Intensity starting point at all ROIs was faster than the surgeon's assessment. The leakage group tended to have slower intensity starting point at ROI 3 compared to those in the non-leakage group (22.5 vs. 19.0 s; P = 0.087). CONCLUSION: A TIC analysis of ICG-NIFI by an independent evaluator was able to quantify the fluorescence intensity changes that the surgeon had visually determined.

The impact of the quantitative assessment procedure for coronary artery bypass graft evaluations using high-resolution near-infrared fluorescence angiography.

PURPOSE: Near-infrared angiography (NIR) is used for on-site graft assessment during coronary artery bypass grafting. This study evaluated the results of a quantitative NIR assessment using a new high-resolution NIR device (h-NIR) for graft assessment. METHODS: Forty-three patients were enrolled in our study. Internal thoracic artery (ITA) grafts anastomosed to the left anterior descending artery and examined intraoperatively using h-NIR were included. The ITA grafts were divided into 2 groups for a comparative analysis: patent grafts (P group; n = 37) and failed grafts (F group; n = 6). The graft flow was evaluated by a "quantitative NIR assessment", and the fluorescence luminance intensity (FLI) was measured. Direct observation of the graft and anastomosis with h-NIR was also performed. RESULTS: The FLI was higher in the P group than in the F group. The receiver operating characteristic analysis revealed the following cut-off values for FLIs depending on imaging duration: 21.1% at 1 s, 35.5% at 2 s, 58.4% at 3 s, and 83.3% at 4 s. The sensitivity and specificity for detecting graft failure were 83.3% and 69.8-80.6%, respectively. Furthermore, h-NIR was also able to visualize arterial dissection in ITA grafts. CONCLUSIONS: A quantitative NIR assessment with an h-NIR device can improve the detectability of anastomotic stenosis, and h-NIR successfully detected arterial dissection of grafts.

Investigation of air bubble properties: Relevance to prevention of coronary air embolism during cardiac surgery.

Although de-airing procedures are commonly performed during cardiac surgery, use of these procedures is not necessarily based on evidence. Uncertainly remains around the size of bubbles that can be detected by echocardiography, whether embolized air or carbon dioxide can be absorbed, and the reasons for embolic events occurring despite extensive de-airing. Since air bubbles are invisible in the blood, we used simple experimental models employing water and 10% dextran solution to determine the correlation between actual bubble size and the depicted size on echocardiography, bubble size, and floatation velocity and the absorption of carbon dioxide under embolization and irrigation conditions. Bubbles depicted as larger than 1 mm were overestimated by echocardiography: the actual size was larger than 0.4 mm in diameter. While bubbles of 0.5 mm had a floatation velocity of 2 to 3 cm/s, the buoyancy of bubbles smaller than 0.3 mm was negligible. Thus, bubbles that are depicted as larger than 1 mm on echocardiography or that present with apparent buoyancy should be visible and need to be meticulously removed. However, echocardiography cannot distinguish bubbles of around 0.1 mm in diameter from those of capillary size (<10 µm). Thus, we advise continuous venting of dense bubbles until they become sparse. While carbon dioxide was rapidly absorbed when circulating, the absorption of embolized carbon dioxide was negligible. These results suggest that detected intracardiac air represents residual "air," with carbon dioxide already absorbed. Therefore, the use of conventional de-airing procedures needs reconsideration: air and buoyant bubbles should be removed from the heart before they are expelled into the aorta; this requires timely and precise assessment with transesophageal echocardiography and effective collaboration between surgeons, anesthesiologists, and perfusionists.

Preoperative AminoIndex Cancer Screening (AICS) abnormalities predict postoperative recurrence in patients undergoing curative resection for non-small cell lung cancer.

BACKGROUND: AminoIndex™ Cancer Screening (AICS (lung)) was developed as a screening test for lung cancer using a multivariate analysis of plasma-free amino acid (PFAA) profiles. According to the developed index composed of PFAA, the probability of lung cancer was categorized into AICS (lung) ranks A, B, and C in order of increasing risk. The aim of the present study was to investigate the relationship between the preoperative AICS (lung) rank and surgical outcomes in patients who underwent curative resection for non-small cell lung cancer (NSCLC). METHODS: Preoperative blood samples were collected from 297 patients who underwent curative resection for NSCLC between 2006 and 2015. PFAA concentrations were measured. The relationship between the preoperative AICS (lung) rank and clinicopathological factors was examined. The effects of the preoperative AICS (lung) rank on postoperative outcomes were also analyzed. RESULTS: The AICS (lung) rank was A in 93 patients (31.3%), B in 82 (27.6%), and C in 122 (41.1%). The AICS (lung) rank did not correlate with any clinicopathological factors, except for age. Based on follow-up data (median follow-up period of 6 years), postoperative recurrence was observed in 22 rank A patients (23.7%), 15 rank B (18.3%) and 49 rank C (40.2%). In the univariate analysis, preoperative AICS (lung) rank C was a worse factor of recurrence-free survival (p = 0.0002). The multivariate analysis identified preoperative AICS (lung) rank C (HR: 2.17, p = 0.0005) as a significant predictor of postoperative recurrence, particularly in patients with early-stage disease or adenocarcinoma. CONCLUSION: Preoperative AICS (lung) rank C is a high-risk predictor of postoperative recurrence in patients undergoing curative resection for NSCLC.

Transesophageal Echocardiography During Cardiopulmonary Resuscitation (CPR-TEE).

BACKGROUND: To take full advantage of transesophageal echocardiography (TEE) during cardiopulmonary resuscitation (CPR), we propose a flowchart derived from representative cases.Methods and Results:TEE was used in patients requiring CPR to obtain information potentially helpful for rescue. TEE navigated the CPR procedures (navigation TEE), identified the possible cause of arrest (focus TEE), and optimized treatment while checking for pitfalls (secure TEE). In addition, TEE corrected prehospital misdiagnoses and detected new complications caused by CPR. CONCLUSIONS: TEE provides valuable information without interrupting CPR procedures. It is hoped that our flowchart may facilitate goal-directed, efficient assessment.

Near-infrared fluorescent solid material for visualizing indwelling devices implanted for medical use.

BACKGROUND: In clinical practice, various devices are implanted into the body for medical reasons. As X-ray fluoroscopy is necessary to visualize medical devices implanted into the body, the development of a less-invasive visualization method is highly desired. This study aimed to investigate the clinical applicability of our novel solid material that emits near-infrared fluorescence. METHODS: We developed a solid resin material that emits near-infrared fluorescence. This material incorporates a near-infrared fluorescent pigment, with quantum yield ≥ 20 times than that of indocyanine green. It can be sterilized for medical treatment. This resin material is designed to be molded into a catheter and inserted into the body with an endoscope clip. In this preclinical experiment using a swine model, the resin material was embedded into the body of the swine and visualized with a near-infrared fluorescence camera system. RESULTS: Endoscopic clips were placed in the mucosa of the stomach, esophagus, and large intestine, and the indwelling ureteral catheters were successfully visualized by near-infrared fluorescence laparoscopy. CONCLUSIONS: We confirmed the tissue permeability of the fluorescence emitted by our novel near-infrared fluorescent material and the possibility of its clinical application. This material may allow visualization of devices embedded in the body.

Feasibility, efficacy, and safety of cell-free and concentrated ascites reinfusion therapy (KM-CART) for malignant ascites.

Efficacy for alleviating signs/symptoms of malignant ascites of a renovated CART (cell-free and concentrated ascites reinfusion therapy) system, called KM-CART, was evaluated. A total of 4781 KM-CART procedures were performed in 2109 patients. All patients were accepted unless hemodynamically unstable or consciousness impaired. The ascites were processed and drip-infused into the patient. There were no major complications or deaths. The mean drainage volume was 6.2 L (maximum: 27.7 L), patient symptoms (numerical scale system) were significantly alleviated (45.1 ± 19.0 reduced to 21.2 ± 14.2, P < .001), and patient leg circumference significantly decreased (33.3 ± 4.4 cm reduced to 30.5 ± 4.4 cm, P < .001) without exacerbation of renal function. Collected cancer cells could be utilized for immune therapy. KM-CART is capable of improving the "quality of best supportive care" and can be beneficial in conjunction with medication for alleviating malignant pain.

Influence of residual coronary flow on bypass graft flow for graft assessment using near-infrared fluorescence angiography.

PURPOSE: Near-infrared fluorescence angiography (NIR) detects the attenuation of fluorescence luminance intensity (FLI) through coronary artery bypass grafts affected by anastomotic stenosis. This study investigates the influence of residual blood flow of the host coronary artery (Ho) on bypass graft (Gr) FLI using a coronary artery bypass (CABG) model. METHODS: A mock circuit system was created using artificial vessels and artificial blood was supplied to the Gr and the Ho. We used NIR to examine the changes in FLI through the Gr. RESULTS: The Gr FLI was significantly attenuated according to the degree of Gr stenosis. The Gr FLI did not differ significantly among all degrees of Ho stenosis. High FLI grafts included grafts with degrees of Gr stenosis ≤ 75%, regardless of the severity of Ho stenosis. Moderate and low FLI grafts had 90 or 99% Gr stenosis, regardless of the severity of Ho stenosis. Gr FLI with 99% Gr stenosis was higher in 99% Ho stenosis than in ≤ 90% Ho stenosis. CONCLUSIONS: A high Gr FLI indicated the absence of ≥ 90% stenosis in the anastomosis and a low Gr FLI indicated severe stenosis in the anastomosis despite Ho stenosis. High Ho stenosis may prevent the attenuation of Gr FLI in severely stenosed grafts.

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.

The history of transesophageal echocardiography: the role of inspiration, innovation, and applications.

Transesophageal echocardiography (TEE), which is commonly used for monitoring and diagnostic imaging during cardiovascular surgery, was originally developed by a strong desire to know what was taking place in the heart in the dark ages of cardiac surgery. The author was fortunate to be present in the midst of the development of TEE and have an opportunity to take a close look at the history of this innovation. Furthermore, the author believes that the history of TEE contains important lessons and tips for solving the problems we presently face in clinical practice. This article describes the history of TEE based on the reports in the early stage of development and discuss how inspiration and innovation was generated by a strong wish and passion to overcome problems. The development of TEE was based on the collaboration of colleagues in different fields, and an intense desire to convert ideas into reality.

Evaluation of graft anastomosis using time-intensity curves and quantitative near-infrared fluorescence angiography during peripheral arterial bypass grafting.

Near-infrared fluorescence angiography (NIR) visualizes blood perfusion using the fluorescence property of indocyanine green (ICG). This study aimed to retrospectively determine the usefulness of a quantitative analysis using NIR to predict the patency of peripheral arterial bypass grafts by measuring their fluorescence luminance intensities (FLIs).Thirteen grafts in 11 patients who underwent peripheral arterial bypass grafting were divided into a patent graft group (n = 7) and a failed graft group (n = 6). The changes in the FLIs of ICG opacification through the graft and distal host artery were retrospectively analyzed using stored NIR data. The time-intensity curves (TICs) of ICG opacification through the graft (Qgraft) and distal host artery (Qdistal) were measured. Two parameters, Δ(Qgraft - Qdistal) and integral(Qgraft - Qdistal), were also analyzed.Although not significant, decreases in Qgraft were observed in the failed graft groups. The Qdistal of the failed graft group was significantly attenuated as compared with that of the patent graft group. Δ(Qgraft - Qdistal) increased only in the failed graft group, which indicates widening of the gap in FLI. Integral(Qgraft - Qdistal) was higher in the failed graft group, as it reflects the accumulation of ICG opacification.The TICs were influenced by anastomotic stenosis in the distal site of the host arteries. Our results indicate that the comparison of Δ(Qgraft - Qdistal) and integral (Qgraft - Qdistal) quantitatively analyzed using NIR can potentially predict anastomotic stenosis.

Mitral annuloplasty for atrial functional mitral regurgitation in patients with chronic atrial fibrillation.

BACKGROUND: Surgical ring annuloplasty is generally performed in patients with symptomatic atrial functional mitral regurgitation (MR) caused by long-standing atrial fibrillation (AF). However, its clinical results have not been well reported. METHODS: Twenty consecutive patients with atrial functional MR (mean age of 68 ± 9 years) and a left ventricular (LV) ejection fraction (EF) greater than 50% underwent mitral annuloplasty. Concomitant procedures included tricuspid valve surgery in 16 patients, AF ablation in 13 patients, and coronary artery bypass grafting in 2 patients. We reviewed the clinical outcomes of those patients and investigated the specific preoperative echocardiographic findings related to MR recurrence. RESULTS: At discharge, the mean left atrial (LA) volume index and mean tricuspid regurgitation peak gradient had significantly decreased from 94 ± 59 mL/m 2 to 58 ± 30 mL/m 2 and from 34 ± 11mm Hg to 23 ± 5mm Hg, respectively. During the follow-up period of 28 ± 17 months, the New York Heart Association functional class significantly improved from 2.3 ± 0.6 to 1.3 ± 0.6. Four patients developed recurrent MR, and of those, two required reoperation. Those with recurrent MR had a significantly larger preoperative LV dimension than those without recurrent MR. Preoperative three-dimensional transesophageal echocardiography was performed in 12 patients, revealing a greater degree of leaflet tethering in patients with recurrent MR than that in patients without recurrent MR. CONCLUSIONS: In patients with the combination of atrial functional MR, left ventricular dilatation and excessive leaflet tethering, mitral annuloplasty alone may not be sufficient to achieve long-term correction of MR.

[Indocyanine Green( ICG) Fluorescence Imaging to Visualize Intersegmental Plane].

Early stage lung cancers which localized in the middle layer or the center of the lung become indications for anatomical segmentectomy. As a method of intraoperative identifying the intra-segmental plane, 2 different techniques utilizing indocyanine green (ICG) fluorescence has been clinically applied. The one is a method of systemically intravenous administration of ICG after ligating the objective segmental pulmonary artery. The other is a method of insufflate the diluted ICG into the objective segmental bronchus under the bronchoscope. The segmental alveoli were visualized with a ICG fluorescence thoracoscope. Both methods visualize inter-segmental plane. Both advantages and disadvantages were discussed. These methods may help the repertoire of atypical segmentectomy getting wider. Also, ICG fluorescence imaging is incorporated into a robotic surgery. ICG fluorescence imaging is expected to be applied to various applications of thoracic surgery.

[Intraoperative Transesophageal Echocardiography].

Transesophageal echocardiography (TEE) provides real-time information on both morphology and hemodynamics without radiation exposure or contrast media, interruption of surgical procedures, or need for transferring the patient to other division, and thus can be used as intraoperative monitoring as well as diagnostic imaging. TEE is helpful for confirming the adequacy of routine surgical procedures, ruling out an occurrence of unexpected adverse events, or even navigating the manipulations of cannulae and catheters. In mitral valve repair, TEE assessment is essential for secure success and making a decision of 2nd pump run with a strategy for re-repair. In acute aortic dissection, TEE is often the only information source for making treatment strategy or detecting unexpected events. TEE provides unique information on properties of tissues, thrombus, or blood, which cannot be identified even with fluoroscopy, thus TEE is to be used efficiently in the hybrid operating room (OR). In thoracic surgery, TEE is helpful for assessing an invasion of tumor to the adjacent structures including the aorta or heart. With all these capabilities of TEE, it should be fully utilized to optimize the outcomes of thoracic and cardiovascular surgeries.

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.

Clinical utility of transthoracic echocardiography for screening abdominal aortic aneurysm: a prospective study in a Japanese population.

BACKGROUND: The aim of the present study was to evaluate the clinical utility of transthoracic echocardiography (TTE) for screening abdominal aortic aneurysm (AAA) and to identify important TTE indices associated with AAA in a Japanese population. METHODS: We prospectively studied 1912 patients who were referred for TTE. AAA was defined as ≥ 30 mm in size. RESULTS: The abdominal aorta was visualized in 95.1% (1818/1912) by TTE. AAA was identified in 2.6% (47/1818). The aortic root size was significantly larger in patients with AAA than those without (36.0 ± 4.1 vs. 31.7 ± 4.2 mm, p < 0.001). The aortic root size had a fair correlation with abdominal aortic size (r = 0.31, p < 0.001). The aortic root size of ≥ 34 mm was predictive of AAA by receiver operating characteristic curve analysis (area under the curve = 0.78, p < 0.001). Multiple logistic regression analysis revealed that aortic root size (Hazard ratio 1.23, p < 0.001) and age (Hazard ratio 1.05, p = 0.013) were the independent predictors of AAA. CONCLUSIONS: The feasibility of the abdominal aortic visualization during TTE was excellent. The aortic root size measured by TTE was the independent predictor of AAA. Screening for AAA during TTE appeared to be useful especially in the older patients with a large (≥34 mm) aortic root.