Early outcomes of thoracoscopic trans-mitral myectomy in obstructive hypertrophic cardiomyopathy patients with left midventricular obstruction / 中华外科杂志

Objective: To examine the early effect of thoracoscopic trans-mitral myectomy for hypertrophic cardiomyopathy patients with left midventricular obstruction. Methods: From April 2020 to July 2021, 10 hypertrophic cardiomyopathy patients with left midventricular obstruction underwent thoracoscopic trans-mitral myectomy at Guangdong Provincial People's Hospital. The whole group of patients consisted of 7 males and 3 females aged (52.0±16.4) years (range: 18 to 68 years). The EuroSCORE Ⅱ predicted mortality rate was 1.78% (1.20%) (M(IQR)) (range: 0.96% to 4.86%). The clinical data were collected and analyzed retrospectively to evaluate the clinical efficacy by comparing preoperative and postoperative echocardiographic parameters using paired t-test, paired Wilcoxon test or Fisher exact test, including left ventricular outflow tract peak pressure gradient, maximum interventricular septum thickness, systolic anterior motion of the anterior mitral leaflet and so on. The safety was determined by summarizing the incidence of perioperative and follow-up complications. Results: All the procedures successed with no conversion to median sternotomy, septal defect, ventricular rupture. There was no in-hospital 30-day death, neither serious complications like permanent pacemaker implantation, re-sternotomy for bleeding, low cardiac output syndrome, stroke, or multiple organ dysfunction syndrome. The left ventricular outflow tract obstruction was effectively relieved in all patients expect a patient developed residual obstruction. Compared with that of pre-operation, the thickness of the interventricular septum was significantly reduced from (22.1±4.0) mm to (10.3±1.7) mm (t=10.693, P<0.01), while the left ventricular outflow tract peak pressure gradient was significantly reduced from (81.7±21.1) mmHg to 12.3 (11.5) mmHg (Z=-2.805, P<0.01) (1 mmHg=0.133 kPa). Conclusion: Thoracoscopic trans-mitral myectomy is an effective and safe procedure for hypertrophic cardiomyopathy patients with left midventricular obstruction.

Surgery for obstructive hypertrophic cardiomyopathy: challenge and future / 中华外科杂志

After more than 60 years of development, with the deepening of the pathophysiological understanding of obstructive hypertrophic cardiomyopathy, the extent and resection thickness of myectomy have increased significantly. Myectomy combined with the correction of anomalies of the mitral valve apparatus has become the standard treatment of obstructive hypertrophic cardiomyopathy. Only a few centers worldwide can routinely perform it due to the difficulty. Because of the advances of new drugs and interventional therapy, the development of surgical treatment faces many challenges. At the same time, generations of cardiovascular surgeons are constantly trying to promote septal myectomy, including developing devices and the surgical field, as well as improving surgical planning by advanced technology. At present, the superior long-term efficacy of septal myectomy has been confirmed. It is necessary to work together to promote the treatment of hypertrophic obstructive cardiomyopathy, so as to guard people's health.

Effect analysis of myectomy guided by personalized three-dimensional reconstruction and printing in the treatment of obstructive hypertrophic cardiomyopathy / 中华外科杂志

Objective: To examine the clinical efficacy of myectomy guided by personalized three-dimensional reconstruction and printing for patients with obstructive hypertrophic cardiomyopathy. Methods: The clinical data of 28 patients with obstructive hypertrophic cardiomyopathy, who underwent septal myectomy guided by personalized three-dimensional reconstruction and printing in the Department of Cardiaovascular Surgery, Guangdong Provincial People's Hospital from May 2020 to December 2021, were retrospectively analyzed. There were 14 males and 14 females, aging (51.1±14.0) years (range: 18 to 72 years). Enhanced cardiac computed tomography images were imported into Mimics software for preoperative three-dimensional reconstruction. The direction of the short axial plane of each segment was marked perpendicularly to the interventricular septum on the long axial plane of the digital cardiac model, then the thickness was measured on each short axial plane. A figurative digital model was used to determine the extent of resection and to visualize mitral valve and papillary muscle abnormalities. Correlation between the length, width, thickness, and volume of the predicted resected myocardium and those of the surgically resected myocardium was assessed by Pearson correlation analysis or Spearman correlation analysis. The accuracy of detecting mitral valve and papillary muscle abnormalities of transthoracic echocardiography and three-dimensional reconstruction was also compared. Results: There was no death or serious complications like permanent pacemaker implantation, re-sternotomy for bleeding, low cardiac output syndrome, stroke, or multiple organ dysfunction syndromes in the whole group. Namely, the obstruction of the left ventricular outflow tract was effectively relieved. The systolic anterior motion of the anterior mitral valve leaflet was absent in all patients after myectomy. The length, width, and thickness of the predicted resected myocardium by three-dimensional reconstruction were significantly positively correlated with the length (R=0.65, 95%CI: 0.37 to 0.82, P<0.01), width (R=0.39, 95%CI: 0.02 to 0.67, P<0.01), and thickness (R=0.82, 95%CI: 0.65 to 0.92, P<0.01) of the surgically resected myocardium, while the relation of the volume of the predicted resected myocardium and the volume of the surgically resected myocardium was a strong positive correlation (R=0.88, 95%CI: 0.76 to 0.94, P<0.01). Importantly, the interventricular septal myocardial thickness measured by preoperative transthoracic echocardiography showed a moderate positive correlation with the volume of surgically resected myocardium (R=0.52, 95%CI: 0.19 to 0.75, P<0.01). During a follow-up of (14.4±6.8) months (range: 3 to 22 months), no death occurred, and 1 patient was readmitted for endocardial radiofrequency ablation due to atrial fibrillation. Conclusion: Personalized three-dimensional reconstruction and printing can not only visualize the intracardiac structure but also guide septal myectomy by predicting the thickness, volume, and extent of resected myocardium to achieve ideal resection.

Protective effect of retrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein and treated with resveratrol on spinal cord injury in swine / 中华外科杂志

<p><b>OBJECTIVES</b>To observe the protective effect of retrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein and treated with resveratrol on spinal cord injury and evaluate the expression changes of microtubule-associated protein 2 (MAP-2) after spinal cord ischemia reperfusion injury (SCII) in swine.</p><p><b>METHODS</b>Eighteen swine were divided into 3 groups: group I/R (n = 6, operation group), group CL (n = 6, retrograde venous perfusion of cryogenic liquid), group CL+Res (n = 6, retrograde venous perfusion of cryogenic liquid and treated with resveratrol after ischemia). In the group I/R, the aorta was clamped for 60 minutes and then removed. In the group CL and CL+Res, 9 g/L cold (4 °C) saline solution (perfusion rate, 16.65 ml/min) was infused into the accessory hemiazygos vein during ischemia.In the group CL+Res, the swine were treated with resveratrol (10 mg/kg) after spinal cord ischemia. Arterial pressure, blood gas analysis and the spinal canal and nasopharyngeal temperature changes were monitored during the surgery. Nervous function were assessed at 6 hours, 1, 2 days, 1, 2, 4 weeks and MAP-2 expression were detected at 4 weeks after reperfusion by using Western blot analysis in spinal cord tissue.</p><p><b>RESULTS</b>After operation 18 swine were all survival. Behavioral scores of all groups decreased until 1 week after reperfusion and increased as time went by. The scores of group CL and CL+Res were higher than group I/R (F = 8.612, 17.276 and 11.985, P = 0.035,0.011 and 0.023) at 6 hours, 1, 2 days, group CL+Res were higher than group CL(P = 0.021) at 1 days after surgery. After descending aortic cross clamping, the spinal canal and nasopharyngeal temperature were obviously decreased in all groups and dropped to the lowest at 60 minutes after ischemia and 20 minutes after reperfusion in group I/R and the other groups respectively(F = 23.187-55.029, P < 0.01).In group CL(0.54 ± 0.26) and CL+Res (0.66 ± 0.31), the MAP-2 expression were higher than group I/R(0.37 ± 0.18) (F = 9.381, P = 0.037) , and the level in group CL+Res was higher than in group CL (P = 0.021) .</p><p><b>CONCLUSION</b>Retrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein and treated with resveratrol can relieve the ischemia-induced spinal cord injury in swine.</p>

Expression and functional role of small conductance Ca(2+)-activated K(+) channels in human atrial myocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression and functional role of the small conductance Ca(2+)-activated K(+) channels in human atrial myocytes.</p><p><b>METHODS</b>We collected the right atrial appendage tissues from 8 patients with congenital heart defect with sinus rhythm undergoing open-heart surgery. Immunohistochemistry was performed to identify the expression of 3 isoforms of SK channel (SK1, SK2 and SK3). Using the classical two-step enzymatic isolation method, perforated patch clamp and conventional voltage-clamp techniques were performed to record the action potentials (APs) and the whole-cell Ca(2+)-activated K(+) current (I(K, Ca)) in the single atrial myocyte. We compared the changes in action potential duration (APD) before and after the application of a specific SK channels blocker apamin (100 nmol/L).</p><p><b>RESULTS</b>Human atrial myocytes showed positivity for all the SK1, SK2 and SK3 isoform channels. Patch-clamp recording confirmed the presence of I(K,Ca), and apamin significantly prolonged APD at 90% repolarization (APD(90)), but produced no obvious effect on APD(50).</p><p><b>CONCLUSION</b>The three isoforms of SK channels are all expressed in human atrial myocytes. SK channels play a prominent role in the late phase of repolarization in human atrial myocytes, which is distinct from their functional roles in neurons where they mediate the process of afterhyperpolarization following APs.</p>

Role of tumor necrosis factor-alpha in the pathogenesis of atrial fibrillation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tumor necrosis factor-alpha (TNF-α) is a pleiotropic proinflammatory cytokine and contributes to many kinds of cardiovascular diseases via its receptors (TNFR1/TNFR2). We hypothesize that TNF-α plays a role in the pathogenesis of chronic atrial fibrillation (AF).</p><p><b>METHODS</b>Sixty-seven consecutive patients who were scheduled to have cardiac surgery were enrolled into the study. Thirty-one patients with rheumatic heart disease (RHD) and AF were enrolled as study group (AF group). The sinus rhythm (SR) control groups consisted of 20 patients with RHD and 16 patients with coronary artery disease (CAD). Peripheral blood sample was collected before the operation. About 5 mm(3) left atrial tissue was disserted during the operation and was separated into three parts for Western blotting, real time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) analysis.</p><p><b>RESULTS</b>Compared with the controls (RHD SR and CAD SR), the levels of TNF-α ((14.40 ± 5.45) pg/ml vs. (4.20 ± 3.19) pg/ml vs. (2.68 ± 2.20) pg/ml, P = 0.000) and its soluble receptor 1 (sTNFR1) ((1623.9 ± 558.6) pg/ml vs. (1222.3 ± 175.6) pg/ml vs. (1387.5 ± 362.2) pg/ml, P = 0.001) in plasma were higher in patients with AF. TNF-α level had positive correlation with the left atrial diameter (LAD) (r = 0.642, P = 0.000). Western blotting analysis showed that the protein levels of TNF-α (0.618 ± 0.236 vs. 0.234 ± 0.178 vs. 0.180 ± 0.103, P = 0.000) were higher in patients with AF. The RT-PCR analysis results demonstrated that the mRNA expression of TNF-α (0.103 ± 0.047 vs. 0.031 ± 0.027 vs. 0.023 ± 0.018, P = 0.000) increased in patients with AF. IHC analysis displayed that, comparing to the SR, the expression of TNF-α (0.125 ± 0.025 vs. 0.080 ± 0.027 vs. 0.070 ± 0.023, P = 0.000) increased in the AF group. The protein level and mRNA expression of TNF-α also had positive correlation with left atrium diameter (LAD) (r = 0.415, P = 0.000 and r = 0.499, P = 0.000).</p><p><b>CONCLUSIONS</b>The results revealed that TNF-α elevated in the plasma and left atrial tissue and had positive correlation with LAD in patients of chronic AF. TNF-α might involve in the pathogenesis of chronic AF.</p>

Early surgical outcomes of coronary heart disease with severe ischemic mitral regurgitation / 南方医科大学学报

<p><b>OBJECTIVE</b>To summarize the experience with surgical treatment of coronary artery disease with severe ischemic mitral valve regurgitation (IMR).</p><p><b>METHODS</b>From January 2006 to December 2009, 45 patients (35 males, 10 females aged 32-74 years) with the diagnosis of coronary artery disease complicated by IMR underwent coronary artery bypass grafting (CABG) combined with mitral valve plasty (MVP, 24 cases) or mitral valve replacement (MVR, 21 cases).</p><p><b>RESULTS</b>Perioperative deaths occurred in 2 cases due to multiple organ failure (MOF). Echocardiography showed a significant reduction of the mitral regurgitation area (from 11.80∓2.45 cm(2) to 2.83∓0.98 cm(2), t=22.80, P=0.00) after CABG combined with mitral valve surgery, with also significantly reduced postoperative left ventricular end diastolic diameter (LVEDD) (from 57.61∓10.06 mm to 51.84∓8.98 mm, t=2.85, P=0.005). No significant difference was detected in the left ventricular ejection fraction after the operation [(52.7∓15.4)% vs (53.2∓13.2)%, t=0.16, P=0.87)].</p><p><b>CONCLUSIONS</b>CABG combined with mitral valve surgery can improve early postoperative left ventricular function in patients with ischemic coronary heart disease complicated by severe mitral regurgitation, but further follow-up study is still needed for evaluation of the long-term results.</p>

Perivenous support with autologous pericardium inhibits neointimal thickening in canine vein grafts / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of perivenous support with autologous pericardium on neointimal thickening in canine vein grafts.</p><p><b>METHODS</b>An autologous pericardium graft of 7 cm x 4 cm was harvested in right anterolateral thoracotomy. Two equal segments of the jugular vein were transplanted to both sides of the femoral arteries in 12 dogs, and on one side of the vein graft, perivenous support with autologous pericardium was applied. The vein grafts were harvested 2 and 4 weeks after operation and the thickness and area of the neointima calculated using computerized image analysis system. Scanning electron microscopy and PCNA immunohistochemistry were also performed.</p><p><b>RESULTS</b>The thickness and area of the neointima were significantly greater in the control grafts than in the grafts with perivenous support (P<0.05), and the proliferation of vascular smooth muscle cells in the supported graft was less active (P<0.05). Electron microscopy showed extensive destruction of the endothelium in the control graft, but only slight damage was found in the graft with perivenous support.</p><p><b>CONCLUSION</b>Perivenous support of the vein graft with autologous pericardium can reduce intimal and medial hyperplasia in the graft.</p>

Clinical analysis of gastrointestinal bleeding after cardiac surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To explore early diagnosis, treatment and prevention of gastrointestinal (GI) bleeding after cardiac surgery.</p><p><b>METHODS</b>In the last 13 years, cases complicated with GI bleeding after cardiac surgeries were analyzed retrospectively.</p><p><b>RESULTS</b>Fourty-four GI bleeding occurred post-operatively in (6 +/- 3) d. The mortality was 23% (10/44). Thirty-eight were located in upper GI tract, of them 26 underwent conservative therapy while 4 died of other than GI bleeding cause; six underwent laparotomy while 1 and 3 died of septicemia and multi-organ failure respectively; six underwent gastric endoscopic hemostasis by electrocautery or clipping the bleeding vessel while all survived. Six were located in lower GI tract, and 2 of them underwent laparotomy without finding bleeding section and died of multi-organ failure. By multivariable logistic regression analysis, deaths were highly related to the post-operative ventilator-dependence, acute renal insufficiency, intra-aortic balloon pump (IABP) assisting and laparotomy.</p><p><b>CONCLUSION</b>The mortality of GI bleeding after cardiac surgeries is very high, early gastrointestinal endoscopic examination and minimally invasive intervention can treat this complication more effectively. GI bleeding must be prevented whenever complicating post-operative ventilator-dependence, acute renal insufficiency, and IABP assisting after cardiac surgery.</p>