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bHLH transcription factor MyoD affects myosin heavy chain expression pattern in a muscle-specific fashion. Am J Physiol Cell Physiol 85: C408-C413, 2001.--A strong correlative pattern between MyoD gene expression and myosin heavy chain IIB (MHC IIB) gene expression exists. To test whether this correlative relationship is causative, MHC gene expression in muscles from MyoD(-/-) mice was analyzed. The MHC IIB gene was not detectable in the MyoD(-/-) diaphragm, whereas the MHC IIB protein. made up 10.0 [+ or -] 1.7% of the MHC protein pool in the wild-type (WT) mouse diaphragm. Furthermore, the MHC IIA protein was not detectable in the MyoD(-/-) biceps brachii, and the MHC IIB protein was overexpressed in the masseter. To examine whether MyoD is required for the upregulation of the MHC IIB gene within slow muscle after disuse, MyoD(-/-) and WT hindlimb musculature was unweighted. MyoD(-/-) exhibited a diminished response in the upregulation of the MHC IIB mRNA within the soleus muscle as a result of the hindlimb unweighting. Collectively, these data suggest that MyoD plays a role in the MHC profile in a muscle-specific fashion. basic helix-loop-helix; fiber type; transcription factor; myogenic regulatory factor

Background Outcome of mitral valve replacement in extreme scenarios of small mitral annulus with the use of the Regent mechanical aortic valve is not well documented. Methods Records were examined in 31 consecutive patients who underwent mitral valve replacement with the use of the aortic Regent valve because of a small mitral annulus. Results Mean age was 60 ± 14 years. Mitral stenosis or mitral annulus calcification was present in 30 of 31 patients (97%). Concurrent procedures were performed in 17 of 31 patients (55%). Median valve size was 23 mm. Mean mitral gradient coming out of the operating room was 4.2 ± 1.5 mm Hg and at follow-up echocardiogram performed at a median of 32 months after the procedure was 5.8 ± 2.4 mm Hg. Conclusions A Regent aortic mechanical valve can be a viable option with a larger orifice area than the regular mechanical mitral valve in a problematic situation of a small mitral valve annulus. Moreover, the pressure gradients over the valve are acceptable intraoperatively and over time. [ABSTRACT FROM AUTHOR]

In an era of broader lung sharing, different-team transplantation (DT, procuring team from nonrecipient center) may streamline procurement logistics; however, safety and cost implications of DT remain unclear. To understand whether DT represents a safe means to reduce lung transplant (LTx) costs, we compared posttransplant outcomes and lung procurement and index hospitalization costs among matched DT and same-team transplantation (ST, procuring team from recipient center) cohorts at a single, high-volume institution. We hypothesized that DT reduces costs without compromising outcomes after LTx. Patients who underwent DT between January 2016 to May 2020 were included. A cohort of patients who underwent ST was matched 1:3 (nearest neighbor) based on recipient age, disease group, lung allocation score, history of previous LTx, and bilateral versus single LTx. Posttransplant outcomes and costs were compared between groups. In total, 23 DT and 69 matched ST recipients were included. Perioperative outcomes and posttransplant survival were similar between groups. Compared with ST, DT was associated with similar lung procurement and index hospitalization costs (DT vs ST, procurement: median $65,991 vs $58,847, P =.16; index hospitalization: median $294,346 vs $322,189, P =.7). On average, procurement costs increased $3263 less per 100 nautical miles for DT versus ST; DT offered cost-savings when travel distances exceeded approximately 363 nautical miles. At our institution, DT and ST were associated with similar post-LTx outcomes; DT offered cost-savings with increasing procurement travel distance. These findings suggest that DT may mitigate logistical and financial burdens of lung procurement; however, further investigation in a multi-institutional cohort is warranted. [Display omitted] [ABSTRACT FROM AUTHOR]

Cardiac hemangiomas are a rare tumor traditionally resected by median sternotomy. We performed a minimally invasive right ventricular cardiac hemangioma resection via a left anterior mini-incision (LAMI). The procedure was without complication, and the patient was discharged on postoperative day 2. The LAMI has been used broadly by our team for operations involving the right ventricular outflow tract, as an alternative to median sternotomy. Here we show that it can also be used for the resection of a cardiac tumor.

Pulmonary insufficiency is a known complication following Tetralogy of Fallot repair. With over 90% of patients now surviving to adulthood, surgeons are once again faced with the question of when, and more importantly, how to reintervene. We developed a novel approach to pulmonary valve replacement in this population through a 5-cm left anterior mini-incision. The incision is optimized for exposing and operating on the right ventricular outflow tract and the main pulmonary artery in patients with a history of median sternotomy. Early outcomes are reassuring, and we believe our approach is a safe and reliable alternative to median sternotomy within this patient population, with the ability to quickly convert intraoperatively when needed.

A 12-year-old, 32 kg male with history of Tetralogy of Fallot status post repair at 8 days of life presented with progressive pulmonary insufficiency and left pulmonary artery stenosis. Surgical options were discussed, and the patient and his family elected to pursue minimally invasive pulmonary valve replacement with left pulmonary artery augmentation through a 5-cm left anterior mini-incision. The procedure was performed without complication, and he was discharged on postoperative day 3. At the time of his last follow-up, the patient was recovering well without evidence of pulmonary stenosis or insufficiency.