Predicting intestinal viability by consecutive photoacoustic monitoring of oxygenation recovery after reperfusion in acute mesenteric ischemia in rats

The purpose was to assess whether consecutive monitoring of oxygenation by photoacoustic imaging (PAI) can objectively predict intestinal viability during surgery for acute mesenteric ischemia (AMI). PAI uses laser light to detect relative amounts of oxygenated and deoxygenated hemoglobin in intestinal tissue. In 30 rats, AMI was induced by clamping the mesenteric and marginal vessels of the ileum for 0 min in the control group, 30 min in the mild group, and 180 min in the severe group (10 rats per group). After 60 min of reperfusion, intestinal damage was evaluated pathologically. Oxygenation of the intestine was monitored throughout the procedure in real time by a commercially available PAI system and compared among the groups. All rats showed irreversible (i.e. transmucosal or transmural infarction) damage in the severe group. After reperfusion, the oxygenation in the mild group recovered immediately and was significantly higher than in the severe group at 1, 5, 10, 30, and 60 min (P = .011, 002, < .001, 001, and 001, respectively). Oxygenation showed a significant strong negative correlation with pathological severity (rs = − 0.7783, − 0.7806, − 0.7422, − 0.7728, and − 0.7704, respectively). In conclusion, PAI could objectively predict irreversible ischemic damage immediately after reperfusion, which potentially prevents inadequate surgery.

Predicting Intestinal Viability After Acute Mesenteric Ischemia by Photoacoustic Imaging: An Experimental Study in Rats

Our purpose was to assess the ability of photoacoustic imaging (PAI) to objectively predict ischemic intestinal pathological damage during surgery for acute mesenteric ischemia (AMI). PAI uses laser light to detect relative amounts of oxygenated and deoxygenated hemoglobin in intestinal tissue. In 18 rats, AMI was induced by clamping the mesenteric and marginal vessels of the ileum for 0 minutes in the sham group (n = 6), 30 minutes in the mild group (n = 6), and 180 minutes in the severe group (n = 6). After 60 minutes of reperfusion, the damage of the intestine was evaluated pathologically. Oxygenation of the intestine was monitored throughout the procedure in real time by the PAI system and compared between the mild and severe groups. All rats showed irreversible (i.e. transmucosal or transmural infarction) damage in the severe group. After reperfusion, the oxygenation in the mild group recovered immediately and was significantly higher than in the severe group at 1, 5, 10, 30, and 60 minutes (P = .007, 014, 016, 008, and 003, respectively). Oxygenation showed a significant strong negative correlation with the pathological severity. In conclusion, PAI could objectively predict irreversible ischemic damage immediately after reperfusion, which potentially prevents inadequate surgery.

Prevalence of myocardial viability and ischemic burden in chronic total occluded coronary artery disease

Aims We assessed the viable myocardium status and investigated the relationship between collaterals with the ischemia burden and myocardial viability utilizing cardiac magnetic resonance imaging (CMR) and adenosine stress single-photon emission computed tomography (SPECT). Methods and results 150 consecutive patients with at least one native CTO artery, as confirmed by coronary arteriography or coronary CT angiography, were prospectively recruited. SPECT examination was accepted by only 50 patients while declined by the other 100 patients for reasons such as financial problems. Of all segments in the 173 CTO artery territories, only 10.4% exhibited transmural myocardial infarction and 60.2% showed no late gadolinium enhancement. Among 50 patients who completed SPECT examination, 36 patients showed inducible perfusion defect in CTO territory, and the proportion of the ischemic area of 42% patients was over 10%. Conclusion Most patients with CTO had different degrees of myocardial infarction detected by CMR, but only a minority of them showed transmural infarction and cardiac function in patients with transmural infarction declined compared to those without transmural infarction. Approximately half of CTO patients exhibited inducible ischemia in CTO territory. Based on this, a large proportion of patients potentially benefit from CTO-PCI. Figure 1. Relationship between WMSI, LVE Funding Acknowledgement Type of funding source: Other. Main funding source(s): Beijing Municipal Education Commission Science and Technology Plan for 2020, Capital Health Development Research Project (no. 2018-2-2063)

Non-ST-segment elevation myocardial infarction with evidence of transmural infarction complicated by left ventricular rupture during percutaneous coronary intervention

We report a case of a 68-year-old man presenting with a non-ST-segment elevation myocardial infarction, complicated by fatal left ventricular free wall rupture with electromechanical disassociation and cardiac tamponade during percutaneous coronary intervention. The aetiology for the sudden haemodynamic collapse was initially unclear; however, transthoracic echocardiography confirmed pericardial tamponade and postmortem revealed complete transmural myocardial infarction with left ventricular free wall rupture. This serves as an important lesson that transmural infarction and subsequent mechanical complications, including ventricular rupture, can occur in non-ST-segment myocardial infarction and not just ST-segment myocardial infarction.

Relationship between apical thrombus formation and blood viscosity in acute anterior myocardial infarction patients

Aim: This study sought to investigate the predictive value of whole blood viscosity (WBV) to identify high-risk patients who will develop an apical thrombus during the acute phase of anterior transmural infarction. Materials & methods: Consecutive 1726 patients with first acute anterior myocardial infarction were evaluated. WBV was calculated according to the Simone’s formula. Results: Patients with an apical thrombus had prolonged pain to balloon time, higher rate of post-PCI thrombolysis in myocardial infarction flow ≤1 and significantly higher mean WBV values at both shear rates than those without an apical thrombus. Conclusion: WBV values at both shear rates were found to be significant and independent predictors for early LV apical thrombus formation complicating a first-ever anterior wall myocardial infarction.

Isolated Myocardial Infarction of the Right Ventricle Complicated by Myocardial Rupture with Cardiac Tamponade in a Female Patient with Arrhythmogenic Right Ventricular Dysplasia

Arrhythmogenic dysplasia of the right ventricle is a rare pathology of the myocardium, the diagnosis of which is difficult. Isolated myocardial infarction of the right ventricle occurs and is diagnosed extremely rarely. In this article we describe a case of arrhythmogenic right ventricular dysplasia, complicated by transmural infarction of the anterolateral wall of the right ventricle, myocardial rupture, and cardiac tamponade.

Transmural Colonic Infarction after Routine Colonoscopy in a Young Patient without Risk Factors

Colonoscopy is one of the most widely used procedures in medical practice for the diagnosis and treatment of many benign and malignant diseases of the colorectal tract. Colonscopy has become the reference procedure for screening and surveillance of colorectal cancer. The overall rate of adverse events is estimated to be about 2.8 per 1,000 procedures, while complications requiring hospitalization are about 1.9 per 1,000 colonoscopies. Mortality from all causes and colonoscopy-specific mortality are estimated to be 0.07 and 0.007%, respectively. An exceptional fearsome postcolonoscopy complication is colon ischemia (CI); only few cases have been reported worldwide. We present the case of a 43-year-old woman who presented to the emergency department complaining of abdominal pain; fever and rectal bleeding appeared 12 h after a voluntary ‘screening’ colonoscopy. She had no risk factors for CI. Her laboratory tests showed alterations in inflammatory markers and a computed tomography scan showed a circumferential thickening in the left colon and free fluid in the abdomen. After 12 h of observation and conservative therapy, the clinical state of the patient worsened with the rising of signs of peritonitis. Laparoscopy showed that colon infarction extended from the distal third of the transverse colon to the proximal rectum. Laparotomy, resection of the pathological colon and terminal colostomy were performed. The specimen examined confirmed an extended ischemic colitis and transmural infarction on the antimesocolic side, in the absence of a vasculitis. The patient underwent recanalization after 8 months. CI after colonoscopy is a rare and alarming complication that must be known and taken into account in the differential diagnosis of symptomatic cases after colonoscopy, particularly in patients with known risk factors. The diagnosis is mainly based on clinical data, imaging and especially endoscopy. Treatment is almost always conservative but, in some cases in which the pathological process appears irreversible, surgery becomes mandatory.

A Series of Unfortunate Events: Prinzmetal Angina Culminating in Transmural Infarction in the Setting of Acute Gastrointestinal Hemorrhage

Prinzmetal angina or vasospastic angina is a clinical phenomenon that is often transient and self-resolving. Clinically it is associated with ST elevations on the electrocardiogram, and initially it may be difficult to differentiate from an acute myocardial infarction. The vasospasm induced in this setting occurs in normal or mildly to moderately diseased vessels and can be triggered by a number of etiologies including smoking, changes in autonomic activity, or drug ingestion. While the ischemia induced is usually transient, myocardial infarction and life-threatening arrhythmias can occur in 25% of cases. We present the case of a 65-year-old female where repetitive intermittent coronary vasospasm culminated in transmural infarction in the setting of gastrointestinal bleeding. This case highlights the mortality associated with prinzmetal angina and the importance of recognizing the underlying etiology.