Objective To compare the effects of high and low positive end-expiratory pressure( PEEP) levels on mortality and risk of barotrauma in patients with acute respiratory distress syndrome ( ARDS) . Methods Randomized controlled trials ( RCTs) were recruited from PubMed( 1966-2008. 9) ,EMBASE( 1980-2008. 9) , Cochrane Database ( Issue 2, 2008) , Chinese Cochrane Centre Database and CBMdisc ( 1978-2008. 9) . Related published and unpublished data and attached references were hand searched. All RCTs about ventilation with PEEP for patients with ARDS were included, then a systematic review were performed. Results Five eligible trials were enrolled in the systematic review. According to ventilation strategy, all trials were divided into subgroup A( low tidal volumes + high PEEP vs traditional tidal volumes + low PEEP) and subgroup B( low tidal volumes + high PEEP vs low tidal volumes + low PEEP) . In subgroup A, high PEEP was associated with a lower mortality[ RR 0. 59, 95%CI( 0. 43, 0. 82) ] and a lower prevalence of barotraumas [ RR 0. 24, 95% CI( 0. 09, 0. 70) ] in patients with ARDS. In subgroup B, the difference in mortality[ RR 0. 97, 95%CI( 0. 83, 1. 13) ] and barotraumas[ RR 1. 13, 95% CI( 0. 78, 1. 63) ]were not significant. Conclusions As compared with conventional ventilation, low tidal volumes and high PEEP ventilation strategy is associated with improved survival and a lower prevalence of barotraumas in patients with ARDS. It is necessary to further confirm the role of sole high PEEP in the ventilation strategy.
Objective To summarize the surgical experiences of ventricular septal rupture (VSR) after acute myocardial infarction (AMI) and investigate the time and methods of surgery. Methods From January 1999 to December 2008, 22 patients with VSR after AMI underwent surgical procedures. There were 17 male and 5 female with a age of 3978 years (mean age of 61.77 years). There were 18 cases with anterior VSR and 4 cases with posterior VSR, all of them combined with left ventricular aneurysm. Twentytwo cases underwent ventricular septal repair and aneurysm resection, 16 cases underwent coronary artery bypass grafting concomitantly with a graft of 2.11±1.57. Results There were 2 perioperative deaths (9.09%), 1 died of severe low cardiac output syndrome and 1 died of massive cerebral embolism. The other 20 cases were all cured and discharged. According to cardiac function classification from New York Heart Association（NYHA）, there were 4 cases in grade Ⅲ, 12 cases in grade Ⅱ and 4 cases in grade Ⅰ. Echocardiography showed that there were no VSR shunt and 2 cases with mild mitral valve regurgitation. Postoperative left ventricular enddiastolic diameter (LVEDD) reduced significantly compared with that before operation (50.27±5.33 mm vs. 57.94±6.79 mm, t=4.437, P=0.000). Sixteen cases were followed up, and the follow-up time was 3.24 months (13.9±6.5 months). Four cases were lost. There was no late death and cardiovascular event during following up. There were 11 cases in cardiac function classification (NYHA) grade Ⅱ and 5 in grade Ⅰ. Echocardiography showed that LVEDD reduced significantly (49.50±4.66 mm vs. 57.94±6.79 mm, t=5.041, P=0.000) and left ventricular ejection fraction (LVEF) increased significantly (55.08%±6.72% vs. 45.57%±11.31%, t=2.719, P=0.013)compared with those before operation. Conclusion VSR after AMI is one of the serious complications of AMI. Proper operation timing, perfect preoperative preparation, appropriate perioperative treatment, right surgical method and the avoidance of complications can effectively reduce the mortality and improve the prognosis.
Abstract: Objective To examine the cell viability and hemodynamic functions of the stented homograft valves preserved in liquid nitrogen. Methods Cell viability of the stented homograft valve preserved in liquid nitrogen after 3 months of preservation (experimental group，n=6) was examined using flow cytometer. Fresh homografts served as control group (n=6). We prepared three sorts of stented homograft valve(21#, 23#, 25#) preserved by liquid nitrogen. In vitro pulsatile flow tests were performed on valves of two groups. Effective opening area EOA),transvalve pressure gradient and regurgitation ratio were recorded at various flow volume, and compare with Perfect bioprosthetic valve. Results The results revealed that the death ratio of endothelial cell was 10.24%±1.71% in the experimental group, and 9.09%±2.72% in the control group (P=0.441). The death ratio of smooth muscle cell was 8.76%±1.82% in the experimental group, and 7.84%±0.59% (P=0.178) in the control group. The death ratio of total cell was 8.79%±1.44% in the experimental group, and 7.40%±0.49% in the control group (P=0.072). There were no significantly differences between two groups. The transvalve pressure gradient of two groups of valve depended on the flow volume, and increased with the flow volume increasing. The transvalve pressure gradient of the stented homograft valve was higher than that of Perfect valve. Regurgitation ratio of the stented homograft valve was bigger than Perfect valve’s. EOA had an increasing character when flow volume increased. EOA of the stented homograft valve was smaller than that of Perfect valve’s. Conclusion Liquid nitrogen can offer the benefit of cell viability of the stented homograft bioprosthetic valves. The stented homograft valve has salisfactory hemodynamic functions.
We developed a three-dimensional finite element model of the pelvis. According to Letournel methods, we established a pelvis model of T-shaped fracture with its three different fixation systems, i.e. double column reconstruction plates, anterior column plate combined with posterior column screws and anterior column plate combined with quadrilateral area screws. It was found that the pelvic model was effective and could be used to simulate the mechanical behavior of the pelvis. Three fixation systems had great therapeutic effect on the T-shaped fracture. All fixation systems could increase the stiffness of the model, decrease the stress concentration level and decrease the displacement difference along the fracture line. The quadrilateral area screws, which were drilled into cortical bone, could generate beneficial effect on the T-type fracture. Therefore, the third fixation system mentioned above (i.e. the anterior column plate combined with quadrilateral area screws) has the best biomechanical stability to the T-type fracture.
ObjectiveTo evaluate the advantages and disadvantages of patch aortoplasty and extended side-to-end anastomosis for the treatment of coarctation of the aorta (CoA) and hypoplastic aortic arch, and provide a more reasonable surgical choice. MethodsClinical data of 45 patients who underwent surgical correction for CoA and hypoplastic aortic arch in Beijing Anzhen Hospital from June 2008 to June 2013 were retrospectively analyzed. According to different surgical strategies for aortic arch hypoplasia, all the 45 patients were divided into 2 groups. In group I, there were 26 patients including 15 males and 11 females with their age of 0.5-6.8 (0.9±2.5) years and body weight of 5.0-20.3 (9.5±7.3) kg, who received patch aortoplasty and whose preoperative pressure gradient between right upper and lower limbs was 38.3±15.6 mm Hg. In groupⅡ, there were 19 patients including 14 males and 5 females with their age of 0.6-7.5 (1.0±2.7) years and body weight of 5.5-21.5 (10.2±6.6) kg, who received extended side-to-end anastomosis and whose preoperative pressure gradient between right upper and lower limbs was 40.7±16.1 mm Hg. Postoperative changes of pressure gradient between right upper and lower limbs of the 2 groups were examined and compared with preoperative values. ResultsTwo patients died postoperatively (4.4%) including 1 patient with low cardiac output syndrome and the other patient with severe lung infection. None of the patients in either group had renal failure or neurological complications. Postoperatively, there were 28 patients whose systolic blood pressure (SBP) of lower extremities was 10-20 mm Hg higher than that of upper extremities, 13 patients whose SBP gradient between upper and limbs was less than 10 mm Hg, and 4 patients whose upper limb SBP was 20 mm Hg higher than lower limb SBP. Postoperative average pressure gradient of right upper and lower extremities was 3.2±13.5 mm Hg and significantly lower than preoperative value (P < 0.05). Postoperative pressure gradient of upper and lower extremities was significantly lower than preoperative value in both groups (P < 0.05). There was no statistical difference in preoperative and postoperative changes of pressure gradient of upper and lower extremities between the 2 groups (P > 0.05). Thirty-eighty patients (88.4%) were followed up from 3 months to 5 years. During follow-up, there was 1 patient whose blood flow velocity of the descending aorta was increasingly accelerated. Pressure gradient across the aortic arch was larger than 40 mm Hg. Computer tomography showed aortic arch restenosis. This patient received reoperation 8 months after the first discharge. Three patients whose aortic pressure gradient was larger than 20 mm Hg were still followed up. Aortic arch pressure gradient was less than 20 mm Hg in all the other patients. ConclusionBoth patch aortoplasty and extended sideto-end anastomosis are ideal surgical methods for the treatment of CoA and hypoplastic aortic arch. Appropriate surgical method should be chosen according to individual conditions of pediatric patients.
Objective To summarize the method and outcomes of surgical treatment for 21 patients with congenital anomalous left coronary artery from the pulmonary artery (ALCAPA). Methods We retrospectively analyzed the clinical data of 21 patients with ALCAPA underwent surgical treatment in our center from January 2010 to January 2015. There were 11 males and 10 females with a mean age of 4.3 years (ranging from 0.5 to 16.0 years) and a mean weight of 19.3 kg (ranging from 5.0 to 97.0 kg). All of 21 patients underwent surgery under cardiopulmonary bypass and corrected malformations. Results There were 2 perioperative deaths and the mortality rate was 9.5%. The mean cardiopulmonary bypass time was 116.6 minutes ranging from 109.0 to 388.0 minutes and the mean aortic cross clamping time was 82.9 minutes ranging from 62.0 to 129.0 minutes. The mean time of hospital stay was 11.1 days ranging from 1.0 to 25.0 days. After surgery, cardiac function improved significantly in all patients. The mean left ventricular ejection fraction (EF), left ventricular fractional shortening (FS), and left ventricular end-diastolic diameter (LVEDD) have significantly improved after surgery (P < 0.05). Conclusions Once patients with ALPACA are diagnosed, they should be treated with surgery and most of them will achieve a satisfactory long term clinical result.
Objective To summarize the experience of the superior vena cava and pulmonary connection surgery for functional single ventricle (SV) with total anomalous pulmonary venous (TAPVC). Methods We retrospectively analyzed the clinical data of 10 patients with SV and TAPVC in our hospital from January 2012 through June 2014. There were 7 males and 3 females at average age of 90.33±86.53 months. The 10 patients were with right atrial isomerism, 9 with heterotary and asplenia syndrome. Five patients were anatomic single ventricle and others were with functional uni-ventricle. Nine patients were with supracardiac pattern TAPVC and one was with intracardiac TAPVC. All patients were operated unilateral or bilateral bidirectional Glenn procedure with TAPVC correction. Results The arterial oxygen saturation (SaO2) increased prominently after operation (86%±6% vs. 79%±6%, P<0.01). There were 3 patients with low cardiac output syndrome, one patient with severe arrhythmia, 4 patients with serious pleural effusion, 4 patients with hospital-acquired infection, and 3 patients with central nervous system complications (epilepsy or hemiplegia). One died because of hemorrhage and pulmonary thrombosis, and the other died of hypoxemia and mutiple organ dysfunction syndrome (MODS). Conclusion Glenn is one of palliated procedure choice for SV/TAPVC patients. The indication for surgery and perioperative management individually is crucial.
ObjectiveTo summarize clinical experience and results of surgical treatment of subaortic membrane (SM). MethodsClinical data of 32 SM patients who underwent surgical resection of SM between March 2009 and September 2013 in Beijing Anzhen Hospital were retrospectively analyzed. There were 22 male and 10 female patients with their age of 0.5-14.0 (3.6±3.2)years and body weight of 5.5-43.0 (17.2±9.5)kg. Among the 32 patients, 7 patients had isolated SM, and 25 patients had other intracardiac lesions including ventricular septal defect in 21 patients, mitral regurgi-tation in 1 patient, patent ductus arteriosus (PDA)in 1 patient, SM occurrence after PDA occlusion in 1 patient and surgical correction for coarctation of the aorta in another patient. Eighteen patients had aortic insufficiency (AI)in different degree. ResultsSM diagnosis was missed by preoperative echocardiography in 1 patient. Mean cardiopulmonary bypass time was 71.7±21.7 minutes, aortic cross-clamping time was 48.7±15.1 minutes, ICU stay was 2.2±1.7 days, and postoperative hospital stay was 7.9±2.5 days. There was no in-hospital death in this group. Postoperatively, 1 patient had second-degree atrioventricular block which returned to sinus rhythm 6 days after the operation. All the patients were followed up for 2-54 months after discharge. During follow-up, AI of 6 patients with isolated SM was relieved, and AI of 5 SM patients with other intracardiac lesions was relieved (P=0.003). Among the 7 patients with isolated SM, preoperative moderate AI in 4 patients changed to mild AI in 3 patients and trivial AI in 1 patient, and preoperative mild AI in 3 patients changed to trivial AI in 2 patients. Among the 25 patients with other intracardiac lesions, preoperative mild AI in 8 patients changed to trivial AI in 3 patients, and preoperative moderate AI in 3 patients changed to mild AI in 1 patients and trivial AI in another patient. There was no SM recurrence during follow-up in this group. ConclusionSM diagnosis may be missed by preo-perative echocardiography, and early surgical correction is needed once the diagnosis is established. Meticulous surgical techniques are necessary during the operation. Postoperative SM recurrence may happen, so regular follow-up is required after discharge.