Preoperative scallop-by-scallop assessment of mitral prolapse using 2D-transthoracic echocardiography

An endoscopically compatible fast-gelation powder forms Janus-adhesive hydrogel barrier to prevent postoperative adhesions

Postoperative adhesions occur widely in various tissues, bringing the risk of secondary surgery and increased medical burden. Hydrogel barriers with Janus-adhesive ability can achieve physical isolation of adjacent tissues and are therefore considered an ideal solution. However, integrating endoscopic delivery convenience and viscoelastic Janus hydrogel formation remains a great challenge. Here, we present a report of the in situ formation of Janus-adhesive hydrogel barrier using a sprayable fast-Janus-gelation (FJG) powder. We first methacrylate the polysaccharide macromolecules to break the intermolecular hydrogen bonds and impart the ability of rapid hydration. FJG powder can rapidly absorb interfacial water and crosslink through borate ester bonds, forming a toughly adhesive viscoelastic hydrogel. The Janus barrier can be simply formed by further hydrating the upper powder with cationic solution. We construct rat models to demonstrate the antiadhesions efficiency of viscoelastic FJG hydrogels in organs with different motion modalities (e.g., intestine, heart, liver). We also developed a low-cost delivery device with a standardized surgical procedure and further validated the feasibility and effectiveness of FJG powder in minimally invasive surgery using a preclinical translational porcine model. Considering the advantages in terms of therapeutic efficacy, clinical convenience, and commercialization, our results reveal the great potential of Janus-gelation powder materials as a next-generation antiadhesions barrier.

Mitral Annular Disjunction Assessed Using CMR Imaging: Insights From the UK Biobank Population Study

BACKGROUND

Mitral annular disjunction is the atrial displacement of the mural mitral valve leaflet hinge point within the atrioventricular junction. Said to be associated with malignant ventricular arrhythmias and sudden death, its prevalence in the general population is not known.

OBJECTIVES

The purpose of this study was to assess the frequency of occurrence and extent of mitral annular disjunction in a large population cohort.

METHODS

The authors assessed the cardiac magnetic resonance (CMR) images in 2,646 Caucasian subjects enrolled in the UK Biobank imaging study, measuring the length of disjunction at 4 points around the mitral annulus, assessing for presence of prolapse or billowing of the leaflets, and for curling motion of the inferolateral left ventricular wall.

RESULTS

From 2,607 included participants, the authors found disjunction in 1,990 (76%) cases, most commonly at the anterior and inferior ventricular wall. The authors found inferolateral disjunction, reported as clinically important, in 134 (5%) cases. Prolapse was more frequent in subjects with disjunction (odds ratio [OR]: 2.5; P = 0.02), with positive associations found between systolic curling and disjunction at any site (OR: 3.6; P < 0.01), and systolic curling and prolapse (OR: 71.9; P < 0.01).

CONCLUSIONS

This large-scale study shows that disjunction is a common finding when using CMR. Disjunction at the inferolateral ventricular wall, however, was rare. The authors found associations between disjunction and both prolapse and billowing of the mural mitral valve leaflet. These findings support the notion that only extensive inferolateral disjunction, when found, warrants consideration of further investigation, but disjunction elsewhere in the annulus should be considered a normal finding.

Spotted Temporal Lobe Necrosis following Concurrent Chemoradiation Therapy Using Image-Guided Radiotherapy for Nasopharyngeal Carcinoma

Background. To explore spotted temporal lobe necrosis (TLN) and changes in brain magnetic resonance imaging (MRI) after image-guided radiotherapy (IGRT) in a patient with nasopharyngeal carcinoma (NPC). Case presentation: a 57-year-old male was diagnosed with stage III NPC, cT1N2M0, in 2017. He underwent concurrent chemoradiation therapy (CCRT) with cisplatin (30 mg/m2) and 5- fluorouracil (5-FU, 500 mg/m2) plus IGRT with 70 Gy in 35 fractions for 7 weeks. The following MRI showed a complete response in the NPC. However, the patient suffered from fainting periodically when standing up approximately 3 years after CCRT. Neck sonography showed mild atherosclerosis (< 15%) of bilateral carotid bifurcations and bilateral small-diameter vertebral arteries, with reduced flow volume. The following MRI showed a 9 mm × 7 mm enhancing lesion in the right temporal lobe without locoregional recurrence, and TLN was diagnosed. The lesion was near the watershed area between the anterior temporal and temporo-occipital arteries. The volume of the necrotic lesion was 0.51 c.c., and the mean dose and Dmax of the lesion were 64.4 Gy and 73.7 Gy, respectively. Additionally, the mean dose, V45, D1 c.c. (dose to 1 ml of the temporal lobe volume), D0.5 c.c. and Dmax of the right and left temporal lobes were 11.1 Gy and 11.4 Gy, 8.5 c.c. and 6.7 c.c., 70.1 Gy and 67.1 Gy, 72.0 Gy and 68.8 Gy, and 74.2 Gy and 72.1 Gy, respectively. Conclusion. Spotted TLN in patients with NPC treated by IGRT may be difficult to diagnose due to a lack of clinical symptoms and radiological signs. Endothelial damage may occur in carotid and vertebral arteries within the irradiated area, affecting the small branches supplying the temporal lobe and inducing spotted TLN. Future research on the relationship between vessels and RT or CCRT and the development of TLN is warranted.

Mitral Valve Prolapse-The Role of Cardiac Imaging Modalities

Mitral valve prolapse (MVP) is the most common nonischemic mitral regurgitation etiology and mitral abnormality requiring surgery in the Western world. There is an increasing awareness that pathological findings in MVP are not confined to the valve tissue; rather, it is a complex disease, involving the mitral valve apparatus, cardiac hemodynamics, and cardiac structure. Imaging has played a fundamental role in the understanding of the diagnosis, prevalence, and consequences of MVP. The diagnosis of MVP by imaging is based upon demonstrating valve leaflets ascending into the left atrium through the saddle-shaped annulus. Transthoracic and transesophageal echocardiography are the primary modalities in the diagnosis and assessment of MVP patients and must include careful assessment of the leaflets, annulus, chords, and papillary muscles. High-spatial-resolution imaging modalities such as cardiac magnetic resonance images and cardiac computed tomography play a secondary role in this regard and can demonstrate the anatomical relation between the mitral valve annulus and leaflet excursion for appropriate diagnosis. Ongoing development of new methods of cardiac imaging can help us to accurately understand the mechanism, diagnose the disease, develop an appropriate treatment plan, and estimate the risk for sudden death. Recently, several new observations with respect to prolapse have been derived from cardiac imaging including three-dimensional echocardiography and tissue-Doppler imaging. The aim of this article is to present these new imaging-derived insights for the diagnosis, risk assessment, treatment, and follow-up of patients with MVP.

Wide-ranging clinical spectrum of paradoxical embolism

The purpose of this review is to raise the index of suspicion for paradoxical embolism among generalists. The review is based solely on anecdotal reports compiled from EMBASE, MEDLINE, Googlescholar and Pubmed. Search terms were 'paradoxical embolism', 'pulmonary embolism' and 'pulmonary arteriovenous malformations'. What emerged was that right-to-left paradoxical embolism could occur with or without concurrent pulmonary embolism, and also with and without proof of the presence of an 'embolus-in-transit'. Potential sites of single or multiple systemic involvement included the central nervous system, the coronary circulation, renal arterial circulation, splenic circulation, the mesenteric circulation and the limbs. In many cases, the deep veins of the lower limbs were the source of thromboembolism. In other cases, thrombi originated from an atrial septal aneurysm, from a central venous line, from a haemodialysis-related arterio-venous shunt, from a popliteal vein aneurysm, internal jugular vein, superior vena cava, from a pulmonary arteriovenous malformation, from tricuspid valve endocarditis (with and without pulmonary embolism) and from the right atrium, respectively. Stroke was by far the commonest systemic manifestation of paradoxical embolism. Some strokes were attributable to pulmonary arteriovenous malformations with or without coexistence of intracardiac shunts. Clinicians should have a high index of suspicion for paradoxical embolism because of its time-sensitive dimension when it occurs in the context of involvement of the intracranial circulation, coronary circulation, mesenteric circulation, and peripheral limb circulation.

The mechanisms, diagnosis and management of mitral regurgitation in mitral valve prolapse and hypertrophic cardiomyopathy

Valvular disease is a frequent cardiac pathology leading to heart failure and, ultimately, death. Mitral regurgitation, defined as the inability of the two mitral leaflets to coapt, is a common valvular disease and a self sustained pathology. A better understanding of the mitral valve histological layers provides a better understanding of the leaflet and chordae changes in mitral valve prolapse. Mitral valve prolapse may occur in myxomatous degenerative abnormalities, connective tissue disorders or in sporadic isolated cases. It is the most common mitral abnormality of non-ischemic cause leading to severe surgery-requiring mitral regurgitation. In addition to standard echocardiographic investigations, newly implemented three-dimensional techniques are being used and they permit a better visualisation, from the so-called ‘surgical view’, and an improved evaluation of the mitral valve. Hypertrophic cardiomyopathy is the most frequent inherited myocardial disease caused by mutations in various genes encoding proteins of the cardiac sarcomere, leading to a marked left ventricular hypertrophy unexplained by other comorbidities. The pathological echocardiographic hallmarks of hypertrophic cardiomyopathy are left ventricular hypertrophy, left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve. The systolic anterior motion of the mitral valve contributes to the development of mitral regurgitation and further narrows the left ventricular outflow tract, leading to more severe symptomatology. Cardiac magnetic resonance imaging accurately measures the left ventricular mass, the degree of diastolic function and it may also be used to distinguish phenotypic variants. The clinical outcome of patients with these pathologies is mostly determined by the selected option of treatment. The purpose of surgical correction regarding mitral valve involvement is to restore valvular competence. Surgery has proven to be the only useful treatment in preventing heart failure, improving symptomatology and reducing mortality. Our approach wishes to enhance the understanding of the mitral valve’s involvement in hypertrophic cardiomyopathy and mitral valve prolapse from genetic, haemodynamic and clinical perspectives, as well as to present novelties in the grand field of treatment.

Comprehensive Two-Dimensional Interrogation of the Tricuspid Valve Using Knowledge Derived from Three-Dimensional Echocardiography

BACKGROUND

Accurate identification of tricuspid valve (TV) leaflets by two-dimensional (2D) transthoracic echocardiography is difficult because of variability in the intersection between the imaging plane and leaflets. Using information obtained from multiplanar reconstruction (MPR) of three-dimensional (3D) data sets, the investigators sought to define "novel" 2D views that would allow targeted interrogation of TV leaflets using 2D transthoracic echocardiography.

METHODS

Images of the TV in the standard 2D views (apical four chamber, right ventricular focused, right ventricular inflow, and parasternal short axis) and 3D data sets were acquired from the same probe position in 106 adults. Three-dimensional MPR was used to determine which leaflet combination was seen in the 2D image: anterior and septal, anterior and posterior, anterior alone, or posterior and septal. Using this analysis, 2D landmarks were identified to define nonstandard TV views tailored to depict specific leaflets. Two-dimensional images in these views and 3D data sets were then prospectively collected in 54 additional patients. Three independent readers analyzed these 2D views to determine TV leaflet combinations, and their interpretation was compared with 3D MPR-derived reference.

RESULTS

Three-dimensional MPR views made it possible to define six nonstandard 2D views on the basis of anatomic clues and landmarks, which consistently depicted all the aforementioned leaflet combinations. When these six views were prospectively tested, the agreement of TV leaflet identification against 3D MPR was excellent (κ = 0.88, κ = 0.93, and κ = 0.98).

CONCLUSION

The nonstandard 2D views defined in this study allow accurate TV leaflet identification and may thus be useful when localization of TV leaflet pathology is clinically important.

Transthoracic two-dimensional xPlane and three-dimensional echocardiographic analysis of the site of mitral valve prolapse

This study sought to assess the value of two-dimensional (2D) transthoracic echocardiography (TTE), 2D xPlane imaging and three-dimensional (3D) TTE for the definition of the site and the extent of mitral valve (MV) prolapse. Fifty patients underwent transthoracic 2D, 2D xPlane and 3D echocardiography. With 2D xPlane a segmental analysis of the MV was performed, by making a lateral sweep across the MV coaptation line as seen in the parasternal short-axis view. Inter-observer agreement for specific scallop prolapse was for 2D xPlane excellent (97 %, kappa = 0.94) and for 3D TTE moderate (85 %, kappa = 0.67). The respective sensitivities of standard 2D TTE, 2D xPlane, and 3D TTE for the identification of the precise posterior scallop prolapse were for P1 92, 85, and 92 %, for P2 96, 96, and 82 %, and for P3 86, 81, and 71 %. In total, 5 (8 %) prolapsing MV scallops were missed by 2D TTE, 7 (12 %) by 2D xPlane, and 12 (20 %) by 3D TTE. The sensitivity of 3D TTE was significantly lower than standard 2D imaging (80 % versus 93 %, P < 0.05). The extent of P2 prolapse was under or overestimated in 5 patients with 2D xPlane and in 9 patients with 3D TTE. 2D xPlane imaging is an accurate, easy to use (compared to 3D TTE) and easy to interpret (compared to 2D and 3D TTE) imaging modality to study the site and the extent of MV prolapse.

The prevalence of hypomagnesaemia in pediatric patients with mitral valve prolapse syndrome and the effect of mg therapy

BACKGROUND

A paucity of data exists regarding the prevalence and relationship of hypomagnesaemia with clinical symptoms of mitral valve prolapse (MVP) in pediatric patients.

OBJECTIVE

In this study we evaluated the prevalence of magnesium (Mg) deficiency in pediatric patients with MVP syndrome and attempted to clarify the effect of Mg therapy on alleviating their symptoms.

METHODS

The present study was conducted from April 2010 to January 2012, and included 230 patients (90 males and 140 females) with symptoms of mitral valve prolapse and mean age of 11.6±3.66. Serum magnesium (Mg) level less than 1.5 mg/dl was defined as hypomagnesaemia. Patients with 2 mm leaflet displacement and maximum leaflet thickness of 5 mm in echocardiography were considered to have classic MVP, while those with leaflet thickness less than 5 mm were considered as non-classic MVP. Patients with hypomagnesaemia were orally treated with 4.5 mg/kg/day Mg chloride for 5 weeks followed by re-evaluation of symptoms of chest pain, palpitation, fatigue and dyspnea.

RESULTS

Hypomagnesaemia was found in 19 (8.2 %) of 230 patients with mitral valve prolapse. The re-evaluation of patients with Hypomagnesaemia after 5 weeks of Mg therapy, showed statistically significant relief of chest pain (P=0.01). However, no significant changes was detected in regard to palpitation (P=0.06), fatigue (P= 0.5) and dyspnea (P=0.99).

CONCLUSION

This study revealed that the prevalence of hypomagnesaemia in pediatric patients with mitral valve prolapse is relatively low compared to adults, but treatment with oral Mg in patient with hypomagnesaemia decreases chest pain.

Ideal site for ventricular anchoring of artificial chordae in mitral regurgitation

OBJECTIVE

Surgical treatment of mitral leaflet prolapse using artificial neochordae shows excellent outcomes. Upcoming devices attempt the same treatment in a minimally invasive way but target the left ventricular apex as an anchoring point, rather than the tip of the corresponding papillary muscle. In this study, cine cardiac magnetic resonance imaging was used to compare these 2 different anchoring positions and their dynamic relationship with the mitral leaflets.

METHODS

Eleven healthy volunteers (mean age, 31 years; 6 female; mean ejection fraction, 62%) were examined by cardiac magnetic resonance imaging (3 Tesla, cine steady free precession technique with retrospective gating), whereby dedicated software enabled assessment of the physiologic distances among 3 anchoring sites (anterior papillary muscle, posterior papillary muscle, and apex) and the plane of the mitral annulus at the level of leaflet coaptation. These distances were measured in systole and diastole, and the performance of virtual neochordae was analyzed for the 3 potential anchoring sites.

RESULTS

Length difference between systole and diastole for the 3 measured distances were 0.19 ± 0.11 cm (5.9% ± 3.4%) for the anterior papillary muscle, 0.19 ± 0.09 cm (6.7% ± 3.6%) for the posterior papillary muscle, and 1.52 ± 0.18 cm (17.8% ± 2.8%) for the left ventricular apex (P = .001). Virtual neochordae between the leaflet and the left ventricular apex were first adjusted in systole to achieve leaflet coaptation. Leaflet tear in diastole can only be avoided if the width of the attached leaflet is larger than the systole-diastole length difference. On the other hand, if virtual neochordae are adjusted in diastole to avoid leaflet tear, residual leaflet prolapse during systole can result. Because the systole-diastole length difference for papillary muscle anchored chordae is smaller than for apical chordae by a factor 10, there is a strongly reduced risk of prolapse or tearing and the leaflet width is unimportant. Furthermore, if the neochordae attached to the anterior mitral leaflet uses the apex as a distal anchoring site, the angle α between the aortic valve plane and this mitral leaflet is significantly reduced in diastole and therefore increases the risk of systolic anterior motion.

CONCLUSIONS

Anchoring of neochordae at the papillary muscles, thereby mimicking the real anatomy, should be preferred over the left ventricular apex. Further analysis of dilated hearts and papillary muscle displacement is necessary to include the whole spectrum of pathologies.