Study on modeling, simulation, and sensorless feedback control algorithm of the cavopulmonary assist device based on the subpulmonary ventricular exclusion / 生物医学工程学杂志

The subpulmonary ventricular exclusion (Fontan) could effectively improve the living quality for the children patients with a functional single ventricle in clinical. However, postoperative Fontan circulation failure can easily occur, causing obvious limitations while clinically implementing Fontan. The cavopulmonary assist devices (CPAD) is currently an effective means to solve such limitations. Therefore, in this paper the

Research and application progress of mechanical circulatory support devices for univentricular circulation / 中国胸心血管外科临床杂志

@#The single ventricular circulation is notable for coexisting systemic venous hypertension and pulmonary arterial hypotension. The use of mechanical circulatory support (MCS) devices is a viable therapeutic treatment option for patients with congestive heart failure. Ventricular assisted devices, cavopulmonary assisted devices, and total artificial heart pumps continue to gain acceptance as viable treatment strategies for single ventricular physiology patients as bridge-to transplantation, bridge-to-recovery, and longer-term circulatory support alternatives. Patients with single ventricular physiology had the lower survival rates compared with those with biventricular circulation. We present a review of the current and future MCS devices for patients with univentricular circulations.

Fontan’s circulation with dextrocardia, recent pulmonary embolism, and inferior vena cava filter: Anesthetic challenges for urgent hysterectomy.

Fontan’s circulation is a unique challenge for the anesthesiologist. Venous pressure is the only source of blood flow for the pulmonary circulation. Patients with such circulation are extremely sensitive to progression of cyanosis (decreased pulmonary blood flow) or circulatory failure. Any major venous compression can compromise the pulmonary blood flow worsening cyanosis; simultaneously, an increased afterload can precipitate circulatory failure. We present a rare patient of surgically corrected Ivemark syndrome with Fontan’s physiology with dextrocardia who developed a large uterine fibroid compressing inferior vena cava (IVC). As a result of compression, not only the pulmonary circulation was compromised but she also developed stasis‑induced venous thrombosis in the lower limbs that lead to pulmonary embolism (PE) (increased afterload). In addition to oral anticoagulation an IVC filter was inserted to prevent ongoing recurrent PE. Further, to prevent both circulatory compromise and deep venous thrombosis an urgent myomectomy/ hysterectomy was planned. In the present case, we discuss the issues involved in the anesthetic management of such patients and highlight the lacunae in the present guidelines for managing perioperative anticoagulation these situations.

No Synergic Effect of Sildenafil Administration on Exercise Capacity Improvement in a Fontan Patient with Regular Exercise Training.

In Fontan patients, reduced exercise capacity due to diminished cardiac output is a common finding with important prognostic implications. Beneficial effects have been shown for sildenafil treatment and regular exercise, but data comparing both strategies is scarce. We report on a female patient with Fontan circulation who underwent repeated cardiopulmonary exercise tests with either placebo or a single dose of 50mg sildenafil before and after 6months of supervised aerobic and resistance exercise. At baseline, V O2peak was 29.1ml/min/kg, and a marked increase to 32.8ml/min/kg was observed after administration of sildenafil. After the training period, V O2peak was 34.5ml/kg/min in the placebo test, and no further increase by sildenafil was possible (33.7ml/kg/min). Similar results were observed for exercise capacity at the ventilatory anaerobic threshold. In summary, this Fontan patient showed that regular exercise might use up and probably exceed the acute sildenafil effects on exercise capacity. Exercise should be considered as a primary treatment strategy within secondary prevention and rehabilitation after the Fontan procedure.