Strain balance of papillary muscles as a prerequisite for successful mitral valve repair in patients with mitral valve prolapse due to fibroelastic deficiency.

AIMS: The aim of this study was to assess the papillary muscle strain as a contributor to recurrent mitral regurgitation (MR) after mitral valve repair for fibroelastic deficiency. METHODS AND RESULTS: Sixty-four patients with isolated posterior mitral valve prolapse and severe MR referred for surgery were prospectively recruited between 2008 and 2012. Two- and three-dimensional echocardiography and speckle tracking were performed in all patients. The longitudinal strain of the anterolateral (AL) and posteromedial (PM) papillary muscles was individually calculated as well as the global longitudinal strain of both papillary muscles was measured before and after mitral repair and normalized to left ventricle end-diastolic volume. Eight patients (12.5%) had at least moderate MR 6 months after mitral repair. The longitudinal strain of the AL (preop -4.94 ± 2.2 vs. postop -3.28 ± 1.3, P < 0.001) and the PM papillary muscles (preop -12.64 ± 5.3 vs. postop -4.12 ± 6.77, P < 0.001) as well as the global strain of both papillary muscles (preop -7.59 ± 3.48 vs. postop -1.07 ± 6, P < 0.001) were all reduced after surgical repair. The longitudinal strain of the PM papillary muscle was the strongest predictor of recurrent MR (when less than or equal to -14.78). The global preoperative papillary muscle strain was also a determinant of recurrent MR when the global strain was greater than -9.05% (area under the curve: 0.895, sensitivity: 100%, and specificity: 76.8%). CONCLUSIONS: Patients with isolated posterior mitral leaflet prolapse are less likely having any residual MR post repair when the global papillary muscle strain of both papillary muscles is close or equal to zero. Strain of the papillary muscles may be an important determinant in predicting residual MR in patients who undergo mitral valve repair.

Sulforaphane pretreatment prevents systemic inflammation and renal injury in response to cardiopulmonary bypass.

OBJECTIVES: Systemic inflammatory responses are a major cause of morbidity and mortality in patients undergoing cardiac surgery with cardiopulmonary bypass. However, the underlying molecular mechanisms for systemic inflammation in response to cardiopulmonary bypass are poorly understood. METHODS: A porcine model was established to study the signaling pathways that promote systemic inflammation in response to cardiac surgery with cardiopulmonary bypass under well-controlled experimental conditions. The influence of sulforaphane, an anti-inflammatory compound derived from green vegetables, on inflammation and injury in response to cardiopulmonary bypass was also studied. Intracellular staining and flow cytometry were performed to measure phosphorylation of p38 mitogen-activated protein kinase and the transcription factor nuclear factor-κB in granulocytes and mononuclear cells. RESULTS: Surgery with cardiopulmonary bypass for 1 to 2 hours enhanced phosphorylation of p38 (2.5-fold) and nuclear factor-κB (1.6-fold) in circulating mononuclear cells. Cardiopulmonary bypass also modified granulocytes by activating nuclear factor-κB (1.6-fold), whereas p38 was not altered. Histologic analyses revealed that cardiopulmonary bypass promoted acute tubular necrosis. Pretreatment of animals with sulforaphane reduced p38 (90% reduction) and nuclear factor-κB (50% reduction) phosphorylation in leukocytes and protected kidneys from injury. CONCLUSIONS: Systemic inflammatory responses after cardiopulmonary bypass were associated with activation of p38 and nuclear factor-κB pathways in circulating leukocytes. Inflammatory responses to cardiopulmonary bypass can be reduced by sulforaphane, which reduced leukocyte activation and protected against renal injury.

Are frozen sections of mediastinoscopy samples as effective as formal paraffin assessment of mediastinoscopy samples for a decision on a combined mediastinoscopy plus lobectomy?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was 'Are frozen sections of mediastinoscopy samples as effective as formal paraffin assessment of mediastinoscopy samples for a decision on a same-day lobectomy?'. Five papers were found using the reported search that represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. These studies compared the efficacy and accuracy of frozen sections (FSs) from mediastinal lymph nodes for staging of patients with lung cancer to determine whether a combined procedure can be planned based on these results and to proceed to thoracotomy and lung resection in cases of negative mediastinal nodes diagnosed by FS. These studies unanimously showed that FS of mediastinal nodes are as accurate as permanent section results and definite histology diagnosis with a sensitivity of >94% and specificity of 100% with no false-positive results. They also confirmed that even in benign lung conditions and other malignancies of the mediastinum, the results of FS are compared with the histology of the node. Based on the current reports, a combined procedure (staging mediastinal nodes by FS and planning for thoracotomy or abandoning thoracotomy) is a safe approach to treat non-small-cell lung cancer (NSCLC). From the patients' point of view, this approach is superior to the staged procedure (mediastinoscopy followed by lung resection at a later date based on the histology of mediastinal nodes) due to single hospitalization and anaesthesia, however whether it is cost effective or not is debatable. It is also labour-intensive and operator-dependent. In conclusion, the current evidence in the literature suggests that a combined procedure of mediastinal node FS followed by lung resection can be a safe alternative to a staged approach to this disease.

A giant saphenous vein graft aneurysm causing left internal mammary artery to left anterior descending artery graft compression.

Saphenous vein graft aneurysm is a rare complication after coronary artery bypass surgery. It is defined as a localized dilatation of the vessel to 1.5× the expected normal diameter. We report a case of 67-year-old man who presented with angina 23 years after coronary artery bypass graft. He was found to have a giant saphenous vein graft aneurysm to diagonal artery compressing the left internal mammary artery graft to the left anterior descending artery. The patient underwent aneurysm resection with satisfactory outcome.