Modified Heterotopic Abdominal Heart Transplantation and a Novel Aortic Regurgitation Model in Rats.

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical technique. Modifying the transplantation procedure to strengthen the myocardial protection could prolong the ischemia time while preserving the donor's cardiac function. This technique's key points are as follows: transecting the donor's abdominal aorta before harvesting to unload the donor's heart; perfusing the donor's coronary arteries with a cold cardioplegic solution; and topical cooling of the donor's heart during the anastomosis procedure. Consequently, since this procedure prolongs the acceptable ischemia time, beginners can easily perform it and achieve a high success rate. Moreover, a new aortic regurgitation (AR) model was established in this work using a technique different from the existing one, which is created by inserting a catheter from the right carotid artery and puncturing the native aortic valve under continuous echocardiographic guidance. A heterotopic abdominal heart transplantation was performed using the novel AR model. In the protocol, after the donor's heart is harvested, a stiff guidewire is inserted into the donor's brachiocephalic artery and advanced toward the aortic root. The aortic valve is punctured by pushing the guidewire further even after the resistance is felt, thus inducing AR. It is easier to damage the aortic valve using this method than with the procedure described in the conventional AR model. Additionally, this novel AR model does not contribute to the recipient's circulation; therefore, this method is expected to produce a more severe AR model than the conventional procedure.

Aortic valve replacement of a quadricuspid aortic valve with right coronary artery ostium adjacent to one of the commissures.

BACKGROUND: Quadricuspid aortic valve is a rare congenital heart disease that may be associated with a different anatomical relationship between the coronary artery ostium and the commissure. CASE PRESENTATION: Herein, we report a case of a 59-year-old woman who underwent aortic valve replacement for a quadricuspid aortic valve with severe aortic regurgitation. Intraoperatively, the aortic valve had four cusps of almost equal size and the right coronary artery arose adjacent to the commissure between the right coronary cusp and one of the two non-coronary cusps. The annular stitches were placed in a non-everting mattress fashion with pledgets on the ventricular side, and stitches near the right coronary ostium were transitioned to the subannular ventricular myocardium to maintain the distance from the ostium. A one-step smaller-sized prosthesis was selected to avoid an oversized prosthetic valve potentially compressing the right coronary ostium. CONCLUSIONS: When performing aortic valve replacement for a quadricuspid aortic valve, careful observation of the coronary location and means to avoid coronary ostium obstruction are essential.

Intrapulmonary artery septation for unilateral absence of the pulmonary artery.

We describe a seven-month-old boy with tetralogy of Fallot and an absent left pulmonary artery. Due to the diminutive size of the left pulmonary artery, we performed a native tissue left pulmonary artery reconstruction and intrapulmonary artery septation procedure with a left modified Blalock-Taussig shunt. After confirming left pulmonary artery growth, the patient underwent tetralogy of Fallot repair, removal of septation patch, and division of the Blalock-Taussig shunt. Nine months post-surgery, we confirmed his balanced lung perfusion (R/L ratio 6:4). The intrapulmonary artery septation procedure would be suitable for both the resuscitation and reconstruction of the hypoplastic absent pulmonary artery.

[Valve Re-replacement after Aortic Valve Replacement with Starr-Edwards Ball Valve Forty-five Years Ago:Report of a Case].

The patient was a 67-year-old man. At 22 years of age, he underwent aortic valve replacement with Starr-Edwards ball valve. At 67 years of age, he complained of fatigue of the New York Heart Association (NYHA) class Ⅲ condition. He was diagnosed with mitral regurgitation, tricuspid regurgitation, ascending aortic aneurysm and chronic atrial fibrillation. Transthoracic and transesophageal echocardiograms showed a mobile, elongated echogenic mass attached to the valve cage and floating downstream. We performed Bentall procedure, ascending aortic replacement, mitral valve replacement, tricuspid annuloplasty and left atrial appendage closure. Explanted ball valve showed extensive cloth destruction and partial cloth tear. Mild pannus formation was observed beneath the valve. Despite 45 years after initial operation, significant valve dysfunction was not observed.

The rare case of a MitraClip device migrating into the left ventricular apex.

A 79-year-old man with atrial fibrillation and heart failure due to grade 4 + mitral valve regurgitation after coronary artery bypass underwent the MitraClip procedure using two clips. Three days after the procedure, chest radiographs indicated migration of one of the two clips into the left ventricle. He suffered from 3 + recurrent mitral regurgitation, tricuspid valve regurgitation. The echocardiogram and computed tomography scans indicated migration of the clip into the left ventricular apex; he underwent mitral valve replacement, removal of the migrated clip to prevent embolism, left atrial appendage closure, and tricuspid valve ring-annuloplasty. In the postoperative acute phase, embolism by detached and lost MitraClip device is possible, which can be difficult to remove.

Outcomes of primary sternal closure for postoperative mediastinitis in children.

OBJECTIVES: We retrospectively analysed outcomes of debridement and primary sternal closure for postoperative mediastinitis in children. METHODS: Between January 2007 and July 2019, 1285 patients under the age of 20 years underwent congenital heart surgery at the Iwate Medical University. Of these, 22 children had postoperative mediastinitis (1.7%). We performed adequate debridement and primary sternal closure with pectoralis major muscle advancement flaps. We evaluated hospital survival rates, reintervention, duration of intravenous antibiotic treatment, intensive care unit (ICU) stay and hospital stay. RESULTS: The median age and weight at surgery were 12.5 months (range 0-228 months) and 7.8 kg (range 2.2-64.2 kg), respectively. Two patients (9%) had a history of delayed sternal closure. Staphylococcus was the most common causative agent for infection (82%). All cases were categorized as Robicsek's classification type II mediastinitis. The hospital survival rate was 95%, and freedom from reintervention for infectious complications was observed in 91% of the patients. The median durations of intravenous antibiotic treatment, ICU stay and hospital stay were 18 days (range 9-46 days), 4 days (range 1-87 days) and 22.5 days (range 11-87 days). The median follow-up time was 89 months (range 2-148 months), and there was no evidence of recurrent mediastinitis, musculoskeletal growth, physical deformity, breast development and upper trunk or limb movement. CONCLUSIONS: Primary sternal closure is an effective procedure for children as it can significantly shorten treatment duration and reduce physical and psychological burdens. Its results compare favourably with those of conventional therapy in terms of mortality and complications.

Adult case of tetralogy of Fallot associated with atrioventricular septal defect.

The patient was a 28-year-old woman who was misdiagnosed with tetralogy of Fallot and straddling mitral valve after birth. She underwent a left modified Blalock-Taussig shunt at the age of 1 year. At age 28, she presented with fatigue and progressive cyanosis. Finally, she was diagnosed with tetralogy of Fallot and complete atrioventricular septal defect. To measure the exact biventricular volumes, we performed cardiac magnetic resonance imaging in addition to cardiac angiography and ensured adequate volume capacity. We eventually decided to perform biventricular repair. Her postoperative course was uneventful, and she returned to full-time work.

[Metastasis of Clear Cell Renal Cell Carcinoma to the Left Ventricle].

Cardiac metastasis from renal cell carcinoma (RCC) is relatively rare. It generally initiates from the right atrium with or without involvement of the inferior vena cava (IVC). Here, we report a case of metastasis of isolated clear cell RCC to the left ventricular( LV) papillary muscle. An 84-year-old male who had undergone renal resection due to RCC 19 years before, presented to our hospital with suspected LV tumor by echocardiography. The tumor was located near the posterior papillary muscle, with a size of 15×12 mm. The patient underwent resection of the LV tumor. Pathologically, the tumor was diagnosed as clear cell RCC. The postoperative course was stable, and he did not require any chemotherapy. Although there is no definite evidence of the mechanisms of metastasis, the tumor was supposed to metastasize lymphogeneously.

A superior vena cava to right pulmonary artery shunt for severe right ventricular outflow tract stenosis caused by an unresectable cardiac tumor.

We report the case of a 47-year-old man who was diagnosed with severe right ventricular outflow tract (RVOT) stenosis due to a space-occupying lesion; the diagnosis was made using computed tomography. He underwent mass reduction, pulmonary valve replacement, and RVOT reconstruction with a bovine pericardial patch. The pathological diagnosis was undifferentiated pleomorphic sarcoma originating from the myocardium. As the mass resection was incomplete, he received heavy particle therapy. He did not want to receive adjuvant chemotherapy. Four months later, severe RVOT stenosis recurred because the residual mass had invaded the prosthetic valve in the pulmonic position and one of the cusps was fixed in the closed position. He presented with dyspnea and marked lower leg edema. We performed superior vena cava (SVC) to right pulmonary artery (RPA) shunting as a palliative operation to improve his heart failure symptoms. After surgery, his symptoms improved; his hemodynamics have been stable for one year. SVC-RPA shunting is a palliative operation but can be used to effectively treat severe RVOT stenosis caused by unresectable cardiac tumors. .