Marcel Vollroth

New concepts for mitral valve imaging

The high complexity of the mitral valve (MV) anatomy and function is not yet fully understood. Studying especially the dynamic movement and interaction of MV components to describe MV physiology during the cardiac cycle remains a challenge. Imaging is the key to assessing details of MV disease and to studying the lesion and dysfunction of MV according to Carpentier. With the advances of computational geometrical and biomechanical MV models, improved quantification and characterization of the MV has been realized. Geometrical models can be divided into rigid and dynamic models. Both models are based on reconstruction techniques of echocardiographic or computed tomographic data sets. They allow detailed analysis of MV morphology and dynamics throughout the cardiac cycle. Biomechanical models aim to simulate the biomechanics of MV to allow for examination and analysis of the MV structure with blood flow. Two categories of biomechanical MV models can be distinguished: structural models and fluid-structure interaction (FSI) models. The complex structure and dynamics of MV apparatus throughout the cardiac cycle can be analyzed with different types of computational models. These represent substantial progress in the diagnosis of structural heart disease since MV morphology and dynamics can be studied in unprecedented detail. It is conceivable that MV modeling will contribute significantly to the understanding of the MV.

Mitral Valve Surgical Procedures in the Elderly

BACKGROUNDnMitral valve (MV) surgical procedures in the elderly are associated with profound operative and long-term mortality. We report our experience and results for MV surgical procedures in the elderly, especially with regard to the influence of comorbidities.nnnMETHODSnOur hospital database was assessed to identify all patients who underwent MV surgical procedures at the age of 70 years and older between 1999 and 2009. The data were retrospectively analyzed.nnnRESULTSnA total of 2,503 patients operated on during this 10-year period were identified. In 97% of patients, mitral regurgitation (MR) was the primary indication for operation, followed by coronary artery disease in 41.6% and aortic valve stenosis in 21.3%. The 30-day mortality rate was 3.1%, and the long-term survival at 5 years was 55.2% (95% confidence interval, 52.3% to 57.5%). Coronary artery bypass grafting was identified to be associated with inferior short-term and long-term survival. Numerous comorbidities significantly influenced long-term survival. The observed mortality was significantly lower than predicted by EuroSCORE (17.2%).nnnCONCLUSIONSnMV operations in the elderly can be performed with a low early mortality and promising long-term survival. However, our large series demonstrates that comorbidities are to be attributed as the real burden for successful treatment of elderly patients undergoing MV procedures.

Gender Differences in Mitral Valve Surgery

BACKGROUNDnKnowledge regarding gender-specific mitral valve (MV) pathology and postoperative outcome is rare. We herein describe a single-center experience focusing on gender differences in MV surgery.nnnMATERIALS AND METHODSnA total of 3,761 patients underwent minimal invasive MV surgery at our institution between 1999 and 2011. Demographic data, pre-, intra-, and postoperative characteristics have been collected, including details on MV pathology and surgical technique. Patient data have been analyzed with consideration of gender-specific differences.nnnRESULTSnThe cohort consisted of 2,124 male (56.5%; 58.8u2009±u200912.5 years) and 1,637 female (43.5%; 64.5u2009±u200913 years) patients. Mitral regurgitation was observed equally in women (91.3%) and men (92.4%). Additional MV stenosis has been diagnosed in 2.7% of men but in 13.9% of women (pu2009<u20090.001). Calcification of the posterior MV leaflet showed a similar trend: 20.1% in women compared with 6.5% in men. Prolapse of the posterior leaflet was present predominantly in men with 63.1 versus 35.7% in women (pu2009<u20090.001). Distinct MV repair differences were retrospectively detected between genders: posterior mitral leaflet resection was performed in 17.9% of men versus 10.1% of women; posterior mitral leaflet chordae replacement was performed in 39.3% of men compared with 20.4% of women. Prosthetic MV replacement was necessary in 26.8% of women compared with only 10.7% of men. Concomitant tricuspid valve surgery was mostly performed in women (14.4 versus 8.2%). Male patients showed a significant better postoperative long-term survival than females, with 96, 89, and 72% compared with 92, 82, and 58% after 1, 5, and 10 years, respectively (pu2009<u20090.0001).nnnCONCLUSIONnSubstantial gender-specific differences regarding MV pathology, operative strategy, and long-term outcome are present that need to be addressed in clinical practice.

Cross-sectional survey on minimally invasive mitral valve surgery

BACKGROUNDnMinimally invasive mitral valve surgery (MIMVS) has become a standard technique to perform mitral valve surgery in many cardiac centers. However, there remains a question regarding when MIMVS should not be performed due to an increased surgical risk. Consequently, expert surgeons were surveyed regarding their opinions on patient factors, mitral valve pathology and surgical skills in MIMVS.nnnMETHODSnSurgeons experienced in MIMVS were identified through an electronic search of the literature. A link to an online survey platform was sent to all surgeons, as well as two follow-up reminders. Survey responses were then submitted to a central database and analyzed.nnnRESULTSnThe survey was completed by 20 surgeons. Overall results were not uniform with regard to contraindications to performing MIMVS. Some respondents do not consider left atrial enlargement (95% of surgeons), complexity of surgery (75%), age (70%), aortic calcification (70%), EuroSCORE (60%), left ventricular ejection fraction (55%), or obesity (50%) to be contraindication to surgery. Ninety percent of respondents believe more than 20 cases are required to gain familiarity with the procedure, while 85% believe at least one MIMVS case needs to be performed per week to maintain proficiency. Eighty percent recommend establishment of multi-institutional databases and standardized surgical mentoring courses, while 75% believe MIMVS should be incorporated into current training programs for trainees.nnnCONCLUSIONSnThese results suggest that MIMVS has been accepted as a treatment option for patients with mitral valve pathologies according the expert panel. Initial training and continuing practice is recommended to maintain proficiency, as well as further research and formalization of training programs.

Conversion rate and contraindications for minimally invasive mitral valve surgery

Over the past 15 years, minimally invasive mitral valve surgery via right lateral minithoracotomy has become the preferred method for mitral valve repair and mitral valve replacement in specialized centers worldwide. This technique refers to specific operation and visualization technologies and new perfusion methods. The minimally invasive approach affords faster patient recovery, less pain, shorter hospital stay and improved cosmesis. Moreover, minimally invasive mitral valve surgery may be an alternative to conventional mitral valve surgery, given that there is comparable short- and long-term mortality and comparable in-hospital morbidity. However, several studies have shown an increased risk of stroke, aortic dissection, groin infections, prolonged cross-clamp time and cardiopulmonary bypass time (1). Owing to severe intraoperative difficulties, conversion to full sternotomy is also a serious complication. n nAt our institution, we have a very extensive experience with minimally-invasive mitral valve surgery, dating back to the late 1990s (2). We therefore aim to review the reasons and the early postoperative outcomes for those patients who underwent conversion to full sternotomy. Furthermore, we outline the contraindications for minimally-invasive mitral valve surgery.

Mitral Valve Regurgitation: A Severe Complication following Left Ventricular Biopsy 15 Years after Heart Transplantation

A 71-year-old male patient underwent orthotopic heart transplantation in 1995. Due to left heart catheterization 15 years later, biopsy from the left ventricular apex was performed for rejection screening. Two days later, echocardiography revealed severe mitral valve regurgitation requiring mitral valve replacement. This is a very rare case showing that left heart biopsy may lead to severe hemodynamic complications with the need for surgical intervention.

Biventricular Levitronix CentriMag Assist Device: A "Bridge to Recovery" Solution in Patients with Acute Fulminant Myocarditis

Fulminant myocarditis (FM) represents a crucial cardiac pathology with extensive hemodynamic compromise occurring in a previously healthy patient. Early death occurs because of acute cardiac decompensation from inflammation, necrosis, and myocytolysis. Nevertheless, in this situation implantation of an extracorporeal circulatory support system may ensure cardiac recovery. We herein report our experience using a biventricular Levitronix CentriMag system for bridge to recovery.

Complex cases of acquired pulmonary vein stenosis after radiofrequency ablation: is surgical repair an option?

AimsnResults of catheter based interventional treatment for pulmonary vein stenosis (PVS) following radiofrequency ablation (RFA) for atrial fibrillation remain suboptimal. Surgical repair may represent an alternative therapy, though long-term results have not been thoroughly investigated.nnnMethods and resultsnWe retrospectively assessed all patients in our centre undergoing surgical repair for radiofrequency-induced PVS. Data regarding surgical technique, clinical outcome, and rate of pulmonary vein (PV) restenosis were collected and analysed. Between 2004 and 2016, the rate for PVS resulting from RFA for atrial fibrillation in our institution was 0.79% (76/9633). During this period, five male patients with multiple PVS (3u2009±u20091) underwent surgical repair of a total of 13 symptomatic PVS. Surgery was performed in a standard setting under cardiopulmonary bypass. Stenotic veins were incised longitudinally followed by a patch augmentation plasty using either bovine pericard (nu2009=u20097) or polytetrafluoroethylene (PTFE) patches (nu2009=u20095). Localization of incision was on the anterior side of the PV only (nu2009=u20098) or on both the anterior and posterior sides (nu2009=u20094). In one PVS lesion, mechanical dilatation was sufficient. Long-term follow-up after 60u2009±u200969u2009months revealed an average restenosis rate of 38%. Restenosis was defined as narrowing >70%. All patients reported clinical improvement of symptoms at follow-up.nnnConclusionnEven in the era of wide circumferential lesions, PVS still occurs. While surgical PV patch plasty represents a valuable treatment option, restenosis remains an issue during follow-up. Nevertheless, surgical repair achieves highly acceptable long-term results for RFA-acquired PVS. Hence, it should be routinely discussed as a therapeutic option in cases with multiple PVS.

Rescue surgery for neonate with huge rhabdomyoma and left outflow obstruction

We describe a rescue operation in a neonate with a large left ventricular tumor obstructing the left ventricular outflow tract. Surgical resection was performed through an aortotomy and transseptal approach. We excised the main part of the tumor, which was obstructing the outflow tract, leaving a portion that was strongly attached to posterior wall of the left ventricle and mitral valve annulus, which was not feasible to remove. Histological examination showed a rhabdomyoma with benign features. The girl was doing well after 3 months, with no residual tumor growth and no signs of obstruction of the left ventricular outflow tract.

Early Effects in Perivascular Nerves and Arterial Media Following Renal Artery Denervation

In the past years 2 different innovative methods of hypertension treatments were investigated. The first is the promising examination of the electrical activation of the carotid baroreceptors, which is now in the phase III studies,1,2 and second the usage of selective renal sympathetic denervation (RSD) as an alternative treatment in therapy-resistant hypertension. RSD is thought to be based on alteration of the sympathetic innervation of kidney and secondary effects on the renin–angiotensin–aldosterone system. The renal nerves are located in close vicinity to the renal artery wall. Their activation could be important for the progression of therapy-resistant hypertension. In this context, Krum et al3 showed the proof of principle of a percutaneous, catheter-based trail to destroy renal sympathetic nerves by the introduction of a RF catheter into the lumen of the main renal artery and its subsequent connection to a radiofrequency generator. Until recently, the renal denervation seemed to be a promising therapy option for antihypertensive treatment. However, the simplicity HTN-3 study as recently announced4 indicated a lack of effect of RSD. Nevertheless, at present, the underlying molecular mechanisms remain unclear during RSD. RF injury might damage the tissue by thermal coagulation but may also cause apoptosis as observed in colon cancer.5 Thus, we made up the hypothesis that RSD may induce apoptosis in the perivascular nerves. The initiation of apoptosis is still not entirely understood. One important pathway is the release of apoptosis-inducing factor (AIF) from the mitochondrial intermembrane space together with cytochrome c .6 Subsequently, AIF translocates to the nucleus and induces chromatin decondensation and DNA degradation, likely by endonucleases. Typically, when inducing apoptosis, AIF and caspases act together. However, AIF may induce cell death in a caspase-independent manner.7 The extrinsic pathway …