Tricuspid leaflet resection in an open beating heart for the creation of a canine tricuspid regurgitation model.

OBJECTIVES: Outcomes of tricuspid valve replacement are poor, partly due to right heart remodelling. The research on its underlying mechanisms is hampered by a lack of animal models of tricuspid regurgitation (TR). Our objective was to create a reproducible and clinically compatible TR animal model to study right heart remodelling caused by TR. METHODS: Fourteen juvenile male Beagle dogs were divided randomly into an intervention group (n = 11) and a sham-operated control group (n = 3). The intervention group underwent thoracotomy and right atrial incision following superior and inferior vena caval occlusion. The anterior leaflet, together with the chordae, of the tricuspid valve was resected in eight dogs ('one leaflet' group), whereas both anterior and posterior leaflets, together with the chordae, were resected in three dogs ('two leaflets' group). The right atrium and chest were then closed. The control group underwent the same procedure, except leaflet resection. One dog from the 'two leaflets' group and one control dog were sacrificed and autopsy was performed at 12 months post-surgery. RESULTS: All dogs survived over the 1-year observation period postoperatively. TR grade IV occurred immediately postoperatively in the 'one leaflet' group, and TR grade IV plus in the 'two leaflets' group. The overall procedure lasted 30-40 min, and the mean time of vena caval occlusion was 87 ± 10 s. Central venous pressure increased from 6 ± 1.2 at baseline to 13 ± 1.7 mmHg (P < 0.01). By 12 months after TR creation, both in the 'one leaflet' group and in the 'two leaflets' group, the right atrial area, tricuspid annular diameter and right ventricular index of myocardial performance increased significantly, right ventricular fractional area change and tricuspid annular plane systolic excursion decreased significantly. Autopsy of the intervention dog revealed oedema, ascites and cirrhosis. CONCLUSIONS: Our surgical technique to create a TR animal model was reproducible with high success and survival rates. This animal model would prove suitable to investigate the mechanisms of right heart remodelling.

Anti-diabetic effects of shubat in type 2 diabetic rats induced by combination of high-glucose-fat diet and low-dose streptozotocin.

ETHNOPHARMACOLOGICAL RELEVANCE: Shubat, probiotic fermented camel milk, has been used both as a drink with ethnic flavor and a medicine among Kazakh population for diabetic patients. Kazakh people have lower diabetic prevalence and impaired fasting glucose (IFG) than do other ethnic groups living in Xinjiang China, which might be related to the beneficial properties of shubat. We therefore prepared shubat in laboratory and tested anti-diabetic activity and evaluated its possible hypolipidemic and renoprotective effects in type 2 diabetic rats. MATERIALS AND METHODS: Type 2 diabetic rats were induced by an administration of high-glucose-fat diet for 6 weeks and an intraperitoneal injection of streptozotocin (STZ, 30mg/kg). Diabetic rats were divided randomly into four groups and treated for 28 days with sitagliptin (30mg/kg) or shubat (6.97×10(6) lactic acid bacteria+2.20×10(4) yeasts) CFU/mL, (6.97×10(7) lactic acid bacteria+2.20×10(5) yeasts) CFU/mL and (6.97×10(8) lactic acid bacteria+2.20×10(6) yeasts) CFU/mL. In addition, a normal control group and a diabetic control group were used for comparison. All drugs were given orally once daily 10mL/kg for 4 weeks. Fasting blood glucose (FBG) and body weight (BW) were measured before treatment and every week thereafter. Total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), serum creatinine (SCr), blood urea nitrogen (BUN), C-peptide, glycated hemoglobin (HbAlc), glucagon-like peptide-1 (GLP-1) levels and pancreas tissue sections were tested after 4 weeks. RESULTS: Shubat demonstrated positive hypoglycemic activity on FBG, HbAlc, C-peptide and GLP-1 levels, high dose shubat decreased FBG (P<0.01) and HbAlc (P<0.05), increased C-peptide (P<0.05) and GLP-1 (P<0.01), decreased serum TC, TG, LDL-c (P<0.05), increased HDL-c (P<0.01), and improved the reduction of body weight as well as decreased SCr and BUN levels (P<0.01) compared to diabetic controls. Histological analysis showed shubat protected the function of islets of type 2 diabetic rats. CONCLUSION: The results of this study indicate that shubat has significant hypoglycemic potential in T2D rats and may modulate lipid metabolism and protect renal function in the type 2 diabetic condition, which might be related to various probiotics acting through promoting the release of GLP-1 and improving the function of ß-cells.

Real-time three-dimensional transesophageal echocardiography to predict artificial chordae length for mitral valve repair.

BACKGROUND: Artificial chordae replacement is an effective technique for mitral valve repair, however, it is difficult to accurately determine the length of artificial chordae. This study aimed to assess the reliability and accuracy of real-time three-dimensional transesophageal echocardiography (TEE) to predict the length of artificial chordae preoperatively. METHODS: From December 2008 to December 2010, 48 patients with severe mitral regurgitation successfully underwent mitral valve repair using artificial chordae replacement. The patients were divided into a TEE pre-measurement group (n = 26) and a direct measurement group (n = 22), according to the method used to determine the length of artificial chordae. Cardiopulmonary bypass time, aortic cross-clamp time, and the recurrence rate of moderate or severe mitral regurgitation were compared between the two groups. RESULTS: There were no operative deaths in either group. The mean cardiopulmonary bypass time was 113.0 ± 18.7 min and 127.0 ± 28.9 min (p < 0.05), and the aortic cross-clamp time was 70.0 ± 16.6 min and 86.0 ± 20.7 min (p < 0.05) in the TEE pre-measurement group and direct measurement group, respectively. The difference between the pre-measured artificial chordal length and actual constructed artificial chordal length was not significant in the TEE pre-measurement group (p > 0.05). Although the difference in the incidence of moderate or severe mitral regurgitation between the two groups was not significant (p > 0.05), the incidence in the TEE pre-measurement group (3.8%) was lower than that in the direct measurement group (18.2%). CONCLUSIONS: Real-time three-dimensional transesophageal echocardiography can accurately predict the length of artificial chordae required for mitral valve repair, and shortens cardiopulmonary bypass time and aortic cross-clamp time while improving the results of mitral valve repair.

Surgical outcome of isolated total anomalous pulmonary venous connection in adults: a 14-year experience.

AIM OF THE STUDY: To investigate the surgical result of adult total anomalous pulmonary venous connection (TAPVC). METHODS: From March 1997 to March 2011, 12 adult cases of isolated TAPVC, with an average age of 24.9 ± 6.7 years (from 18 to 41 years), underwent surgical repair in our department. All patients suffered from right-sided volume overload with clinical manifestations varying from mild cyanosis to severe heart failure. RESULTS: According to Darling's classification, eight cases were classified as supracardiac type, four as cardiac type. Unobstructed connections were established between the left atrium and the pulmonary common vein in all patients with external cardiac approach in four supracardiac cases, and internal cardiac approach in four cardiac and three supracardiac cases, and Warden technique in one supracardiac patient. Concomitant operations included De Vega's tricuspid annuloplasty in six patients, patent arteriosus ductus closure in two. All patients survived the operation, and postoperative follow-up was 100% complete with a period ranging from 10 months to 14 years. NYHA grade decreased from 2.33 ± 0.49 to 1.08 ± 0.29 (p < 0.01). Three patients had postoperative tricuspid insufficiency. Five patients had cardiac arrhythmia, among two symptomatic cases; one controlled with medication, another received a successful radiofrequency ablation for incision-related atrial flutter. CONCLUSIONS: Surgical correction of isolated adult TAPVC can be carried out safely with acceptable long-term outcome. Postoperative tricuspid insufficiency and cardiac arrhythmias may have a negative long-term impact, which should be evaluated preoperatively and managed individually during surgery.

Matrine inhibits disturbed flow-enhanced migration via downregulation of ERK1/2-MLCK signaling vascular smooth muscle cells.

BACKGROUND: To investigate the effects of matrine on the vascular smooth muscle cell (VSMC) migration modulated by disturbed flow and their underlying molecular mechanisms in vitro. METHODS: Isolated rat aortic VSMCs were grown to confluence on 20- × 80-mm fibronectin-coated glass cover slides, and then, denuded zones were made at the position calculated to be the oscillating flow-reattachment zone and also in the downstream laminar flow region. VSMCs were treated with different doses of matrine (0, 10, 20, 30, and 40 mg/L), or PD98059 (30 µM), ML-7 (10 µM) combined with matrine (40 mg/L) for 30 minutes before and during the experiments. Then, the wounded monolayers were kept under static conditions or were subjected to laminar or disturbed flow for 21 hours or 10 hours. The VSMC migration was assessed by microscopic images. The extracellular signal-regulated kinase 1/2 (ERK1/2) and myosin light chain kinase (MLCK) proteins were determined by Western blot. RESULTS: Disturbed flow significantly increased phosphorylation of ERK1/2. Selective inhibition of ERK1/2 phosphorylation by inhibitor PD98059 and matrine significantly suppressed VSMC migration under disturbed flow. Disturbed flow significantly enhanced phosphorylation of MLCK, whereas both matrine and PD98059 inhibited the phosphorylation of MLCK under disturbed flow. The complete inhibition of MLCK phosphorylation using the selective MLCK inhibitor ML-7 significantly inhibited VSMC migration under disturbed flow. CONCLUSION: Matrine inhibits VSMC migration under disturbed flow, in part, by downregulation of ERK1/2-MLCK signaling pathway.

Determination of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry.

A sensitive and rapid method was developed for quantification of olprinone in human plasma utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS). An aliquot of 1 mL plasma sample was extracted with ethyl acetate-dichloromethane. Separation of olprinone and the milrinone (internal standard, IS) from the interferences was achieved on a C(18) column followed by MS/MS detection. The analytes were monitored in the positive ionization mode. Multiple reaction monitoring using the transition of m/z 251 → m/z 155 and m/z 212 → m/z 140 was performed to quantify olprinone and IS, respectively. The method had a total chromatographic run time of 3 min and linear calibration curves over the concentration range of 0.5-60 ng/mL. The lower limit of quantification (LLOQ) was 0.5 ng/mL. The intra- and inter-day precisions were less than 16.3% for low QC level, and 7.1% for other QC levels, respectively. The intra- and inter-day relative errors were ranged between -12.2% and 3.7% for three QC concentration levels. The validated method was successfully applied to the quantification of olprinone concentration in human plasma after intravenous (i.v.) administration of olprinone at a constant rate of infusion of 2 µg/(kg min) for 5 min in order to evaluate the pharmacokinetics.

[Surgical treatment of 128 cases of constrictive pericarditis].

OBJECTIVE: To summarize the experience with surgical treatment of constrictive pericarditis. METHODS: A retrospective analysis of the post-operative clinical data was conducted in 128 surgical patients with chronic constrictive pericarditis. RESULTS: Two early postoperative death occurred in this group due to severe low cardiac output syndrome, with the mortality rate of 1.57%. The postoperative complications included low cardiac output syndrome (13.2%), arrhythmia (7.02%), acute renal insufficiency (3.9%), respiratory insufficiency (3.1%), wound infection (2.3%), postoperative chest bleeding (1.6%) and cerebral infarction (0.78%). Relapse occurred in one case because of incomplete pericardial resection. CONCLUSIONS: Constrictive pericarditis should be confirmed as soon as possible with actively surgery, and the extent of pericardial resection should be decided according to the individual conditions. Complete untethering of the diseased pericardium should be performed with active prevention of postoperative complications.

The short-term pulsatile ventricular assist device for postcardiotomy cardiogenic shock: a clinical trial in China.

Despite the recent advances in myocardial protection, surgical techniques, intra-aortic balloon therapy, and maximal pharmacological support, postoperative ventricular dysfunction continues to occur in 0.5-1.0% of all patients undergoing cardiac surgery. Ventricular assist device (VAD) is an important therapeutic adjunct in treating patients with profound ventricular dysfunction with postcardiotomy cardiogenic shock. The purpose of this report was to describe the clinical results with the China-made Luo-Ye VAD as a short-term circulatory support. From May 1998 to December 2006, 17 patients with postcardiotomy cardiogenic shock were supported by the Luo-Ye VAD. Of these patients, 10 were males and seven were females with a mean age of 49.6 years (range 36-68 years). All cases were supported by left VAD (LVAD). Mean duration of support was 46.3 h (range 13-113 h). A criteria of insertion was established to standardize implantation criteria. Among the 17 patients treated with LVAD, eight (47.1%) patients were weaned from support and seven (41.2%) patients were discharged from hospital. Ten (58.8%) patients died while on LVAD support (nine cases) or shortly after weaning (one case). The causes of death in the entire group were cardiac (40%), renal failure (20%), neurologic (10%), sepsis (10%), and multiple organ system failure (20%). The complications were represented by bleeding, renal failure, neurologic event, infection, ventricular arrhythmias, etc. The Luo-Ye VAD functioned well and proved to be useful in patients with postcardiotomy cardiogenic shock. It carries a less-postoperative anticoagulant and a low incidence of VAD-related complications. The survival rate was encouraging in our small cohort of patients.

The orthotopic left lung transplantation in rats: a valuable experimental model without using cuff technique.

Advances in the field of clinical lung transplantation must rely on observations made in animal models. In this study, we introduced a new procedure in the rat, orthotopic left lung transplantation without using the cuff technique, in which the donor pulmonary artery, pulmonary vein, and membranous parts of the bronchus were anastomosed continuously in the lumen using a mattress suture under a surgical microscope; meanwhile, a second, low-pressure perfusion through the pulmonary artery and turnover of the vascular stump were made, which also made the vessel anastomosis easy. Transplantations were completed in 68 rats (89.5%), the mean time used for suturing the left lung hilar structure was 23.5 +/- 4.6 min. All lung grafts had good life-sustaining function because of there being no cuff-induced granulation tissue in bronchial anastomotic stoma, and three out of 12 allografts were observed with active bronchiolitis obliterans lesions at 8 weeks after transplantation. This model is a simple, valuable experimental model for studying lung transplantation and new therapies for preventing acute or chronic rejection.

Surgical treatment of late tricuspid regurgitation after left cardiac valve replacement.

BACKGROUND: The development of late tricuspid regurgitation (TR) following left cardiac valve replacement is an important complication, as it is associated with a severe impairment of exercise capacity and a poor symptomatic outcome. The pathogenesis of this condition remains poorly defined. It is still a challenge in terms of its prevention, treatment and indications for surgical correction. AIMS: To investigate the possible pathogenesis and report the surgical results of the late TR after left cardiac valve replacement. METHODS: There were 56 patients with moderate to severe TR after left cardiac valve replacement, divided into normal prosthesis group (10 patients with normal prosthetic valve function) and dysfunctional prosthesis group (46 patients with prosthetic valve dysfunction). In the normal prosthesis group, 4 patients underwent mitral valve replacement (MVR) and 6 patients underwent combined mitral and aortic valve replacement (DVR). Patients in the dysfunctional prosthesis group included MVR in 36, aortic valve replacement (AVR) in 4 and DVR in 6, with bioprosthetic valve dysfunction occurring in 18, mechanical prosthetic valve obstruction in 22 and periprosthetic valve leakage in 6 patients. At the initial operation, 10 patients underwent DeVega's tricuspid annuloplasty and 46 patients' tricuspid valves were normal. At the second operation, the surgical treatment of TR included tricuspid valve replacement (TVR) in 9 and tricuspid annuloplasty in 47. RESULTS: Two patients died postoperatively giving a 3.6% hospital mortality. The 54 survivors were followed up for 6-132 months (mean of 79.4 months). Heart function improved significantly in 8 with TVR and in 40 with tricuspid annuloplasty. Echocardiography showed moderate TR in 5 and severe TR in 1 patient with tricuspid annuloplasty who need a further surgical treatment. CONCLUSION: Pulmonary hypertension, myocardial dysfunction, and atrial fibrillation might be responsible for the development of late TR after left cardiac valve replacement. Tricuspid annuloplasty, as the surgical method of first choice, resulted in improvement in 87% of patients with late TR after left cardiac valve replacement. TVR can also be safely applied to repair organic disease and the extremely dilated tricuspid valve annulus. If the TR area is more than 25cm(2), the TVR is recommended.