| ObjectivesWe sought to investigate the feasibility and safety of totally thoracoscopic repair of a ventricular septal defect and to investigate the feasibility and safety of totally thoracoscopic replacement of mitral valve through three ports in right chest. To verify mode thoracoscopic cardiac surgery and surgical reliability, clinical treatment norms for thoracoscopic techniques to lay the theoretical foundation in the cardiac surgery and clinical application promotion.MethodsPatient selectionThis study was approved by the institutional review board of Qilu Hospital and Liaocheng People’s Hospital. Written informed consent was obtained from all participants before the study.Part I Written informed consent was obtained from all participants before the study. Between Sept2011and March2013, patients with congenital VSD were selected from the Department of Cardiac Surgery of the two hospitals. The selection criteria were:a) VSD of any size; b)>2years old with a body weight of more than15kg; c) pulmonary arterial systolic pressure (measured by echocardiography)<60mmHg; d) no previous history of lung disease or surgeries on the right chest; and4) no other cardiovascular disease or chronic illnesses. Of the selected119patients, there were66male and53females with a mean age of7.1±3.6years (range,2-36). The mean body weight was32.4±7.8kg (range,18-68). Echocardiographic examination showed membranous VSD in64, paramembranous VSD in55. The size of the defect ranged from4mm to14mm. Twenty-eight patients had mild pulmonary hypertension (pulmonary arterial pressure30-40mmHg),22patients had moderate pulmonary hypertension (pulmonary arterial pressure,40-59mm Hg), and6had severe pulmonary hypertension (pulmonary arterial pressure,60-90mm Hg). Sixteen patients also had tricuspid regurgitation due to right ventricular dilation. Valvuloplasty using DeVega technique and Edware ring were performed in nine and three patients, respectively, after the VSD repair in the same procedure. Follow-up echocardiographic studies showed no tricuspid regurgitation in these patients.Part II Written informed consent was obtained from all participants before the study. Between Oct2011and March2013,62patients with rheumatic heart disease were selected from the Department of Cardiac Surgery of the two hospitals. The selection criteria was:a) New York Heart Association functional class Ⅰ/Ⅱ; b) Age>15years old with a body weight of more than45kg; c) no left atrial thrombosis; d) Pulmonary arterial systolic pressure (measured by echocardiography)<60mmHg; e) no previous history of lung disease or surgeries on the right chest; and f) No other cardiovascular disease or chronic illnesses. Of the selected62patients, there were27males and35females with a mean age of51.7±5.6years (range,28-65). The mean body weight was66.4±6.7kg (range,48-90). Echocardiographic examination showed mitral valve stenosis in39, mitral valve regurgitation in10and combined mitral valve stenosis and regurgitation in13. Twenty-eight patients had mild pulmonary hypertension (pulmonary arterial pressure30-40mmHg), and13had moderate pulmonary hypertension (pulmonary arterial pressure,40-59mm Hg).AnesthesiaAfter induction of general anesthesia, a left-sided double-lumen endotracheal tube (>50kg) or single-lumen endotracheal tube(<50kg) was placed to allow for single-lung ventilation. The respiration rate was set between18-30/min and the arterial oxygen saturation rate was maintained at>97%. After the induction of general anesthesia, a transesophageal echocardiography probe was inserted to monitor the VSD closure. Cardiopulmonary bypass was established peripherally through femoral vein and femoral arteries.Surgical techniquesThe patient was positioned in a15-20degree left lateral decubitus position. Three small incisions (ports) were made on the right side of the chest. Port1(1-1.5cm) was located in the3th intercostal space inside of right midclavicular line. This port was for the insertion of surgical instruments such as tissue forceps, using the left hand (for a right-handed operator). Port2(1-1.5cm) was for the entry of instruments, such as scissors, suture needle, handled by the right hand of the operator. It was located in the5th or6th intercostal space outside right midclavicular line. Port3(1.5-2.0cm) was located in the4th intercostal space between mid-axilliary line and anterior axillary line. This port was for the placement of thoracoscopy.Once the ports were made, a tissues retractor was inserted into each of the three ports to keep the ports open and to facilitate the insertion or withdrawal of the instruments or thoracoscopy. First, a thoracoscopy was inserted through port3to visualize the right mediastinum.Pericardiotomy was performed and one suture was placed to suspend the pericardium. Caval snares were placed in the superior and inferior vena cava before commencing cardiopulmonary bypass. A3mm incision was made between left-superior pulmonary vein and the left atrium for the insertion of a left atrium drainage tube. The thoracoscopy was then removed from port one and repositioned through port2to visualize the root of the aorta. An aortic crossclamp was positioned on the ascending aorta, and a perfusion needle was inserted through port3to the aortic root for the delivery of cold St Thomas cardioplegic solution to achieve cardiac arrest.Part I The thoracoscopy was then repositioned through port3to visualize the right atrium. A tissue forceps and a scissors were entered through port1and port2, respectively. After the right atrium was opened from a site parallel to the atrioventricular annulus, three stay sutures were placed on the incision to expose the intra-atrial structure. The tricuspid valves were pulled apart and one stay suture was placed on the interventricular septum to expose VSD. For a defect of<6mm, direct suture (5-0or4-0Prolene) was used for closure. A bovine patch (Bairen Med Pharma Co, Beijing, China) was used to repair defects>6mm, using running Prolene sutures. DeVega technique or artificial tricuspid valves ring was used to repair tricuspid valve regurgitation.Part II The thoracoscopy was then repositioned through port3to visualize the right atrium. A tissue forceps and a scissors were entered through port1and port2, respectively. After the right atrium was opened from a site parallel to the atrioventricular annulus and atrial septal was opened in longitudinal axis of fossa ovalis, three stay sutures were placed on the incision to expose the left atrial structure and mitral valve. The mitral valves were ablated and Prosthesis was placed on home position, using interrupted sutures.After VSD or MVR closure, the right atrium was closed, and the air was exhaust from left heart. The aortic crossclamp was released, and the patient was rewarmed. Integrity of the VSD closure was confirmed by transesophageal echocardiography, and protamine sulfate (1:1) was administered to reverse the actions of heparin. After adequate hemostasis was achieved, all instruments were removed from the chest, and an18-24F chest tube was inserted in the right pleural space through port2for drainage. Finally, the cannulas in the right femoral vein and artery were removed, and incisions on the blood vessels were closed with sutures.In order to compare operational data and requirement for post-operative analgesics between conventional and thoracoscopic VSD closure,35patients undergoing open-chest surgery for VSD closure between June2009and March2012were selected. These patients were matched in the VSD types with the last35patients in the thoracoscopic group.Perioperative managementPrior to the surgery, education and counselling were provided to all participants on surgical techniques, possible clinical outcomes, potential complications and postoperative self-care measures. Lung function test was routinely performed in all patients before the surgery. The lungs were inflated every20min during the operation. Femoral artery and vein were assessed by colour Doppler ultrasound. Bedside chest X-ray was routinely performed in the intensive care unit to exclude complications in the lungs. Mechanical ventilation was ceased once patient’s hemodynamics was stabilized in operation room or in the intensive care unit.Statistical analysisSPSS v13.0was used for the statistical analysis. Quantitative variables are expressed as mean±SD. P value<0.05was considered statistically significant.Results Part I One patient had bleeding due to the injury to the inferior vena cava and the right atrium. Another patient had bleeding from the ascending aortic where a needle was inserted to perfuse cardioplegic solution. In both cases, the chest incision at port2was extended to4-5cm for better visualization of the bleeding sites, which were successfully stopped with sutures. Thoracoscopic VSD repair was successfully completed after the bleeding from the inferior vena cava or ascending aorta was stopped. Valvuloplasty using DeVega technique and Edware ring were performed in nine and three patients, respectively, after the VSD repair in the same procedure. Follow-up echocardiographic studies showed no tricuspid regurgitation in these patients.All patients survived the operation and being discharged from the hospital in4-6days. No patient in this cohort underwent reoperation for bleeding following the VSD repair. The mean CPB time was42.2±9.8min (range,34-142). The mean aortic crossclamp time was32.5±7.3min (range,25-57). Once the aortic clamp was removed, heart beat resumed spontaneously in84patients. In33patients,50W DC shock through the chest wall was performed to cardiovert the fibrillating heart back to sinus rhythm. The mean mechanical ventilation time was0.3±0.4h (range,0-19) and the mean duration of intensive care stay was11.0±2.6h (range,4-28). There was statistically significant difference in the mean mechanical ventilation time (0.3±0.4vs4.9±3.2h,P<.05) and duration of intensive care stay (11.0±2.6vs22.9±4.7h P<.05) between the six patients with severe pre-operative pulmonary hypertension and those with mild or moderate pre-operative pulmonary hypertension.In all patients, transesophageal echocardiography immediately after the VSD repair showed complete closure with no residual shunt. Three patients (2.26%) experienced arrhythmia, one had high degree atrioventricular conduction block which spontaneously recovered within24h following the operation. One had third degree atrioventricular conduction block which had not spontaneously recovery within seven days following the operation and was fitted with a permanence pacemaker. The other patient suffered atrial fibrillation following the VSD repair, but sinus rhythm returned after52h. One (0.75%) suffered from residence shunt which the size1mm and it closed itself in one month after the operation. One (0.75%) suffered from right pulmonary atelectasis which was recovered in two days following chest physiology therapy.Twenty-one patients (16%) required blood transfusion of400ml each during the procedure. The total volume of the post-operative chest drain ranged from30to460ml (mean,55±12ml). Patients have been followed up for6.8±3.9months (3-12months), with no signs of residual shunt on transthoracic echocardiography. Patients resumed work or schooling between14and23days (median,16) following the surgery.There was no significant difference in age, sex, cardiopulmonary bypass time and aortic crossclamp time between thoracoscopic and control group (P>.05). In the thoracoscopic group, total operation time, mechanical ventilation time, the blood loss during the surgery was significantly less than in the control group (P<.01), and the intensive care or hospital stays were shorter (P<.05). In the thoracoscopic group,38(31.9%) patients required opioid analgesics. In the control group,26patients (74.2%, P <.01) were administered with opioid analgesics for1-2days following the surgery.Part Ⅱ None of the cases required extension of chest incision. In one patient insertion of right femoral artery catheter was unsuccessfully therefore left femoral artery access was used. Valvuloplasty using DeVega technique and Edware ring were performed in6and18patients, respectively, after the mitral valve replaced in the same procedure. In5patients mitral valve replacement procedure was performed through interatrial groove incision. Follow-up echocardiographic studies showed no tricuspid regurgitation in these patients.The mean CPB time was62.2±9.8min (range,44-145). The mean aortic crossclamp time was41.5±7.3min (range,39-77). Once the aortic clamp was removed, heart beat resumed spontaneously in50patients. In12patients,50W DC shock through the chest wall was performed to defibrillate the heart. The mean mechanical ventilation time was2.2±0.6hours (range,1-22) and the mean duration of intensive care stay was14.1±4.5hours (range,6-48). No patient in this cohort underwent reoperation for bleeding following the mitral valve replacement. All patients were discharged from the hospital6-7days following the procedure.In all patients, transesophageal echocardiography immediately after the mitral valve replacement showed normal position and function of the prosthesis with no periprosthesis leakage.Newly onset of atrial fibrillation was found in6patients after the operation. One patient suffered from right pulmonary atelectasis which was recovered in two days following chest physiology therapy. Eleven patients (17.7%) required blood transfusion of400-800ml each during the procedure. The total volume of the post-operative chest drain ranged from30to460ml (mean,65±14ml).Patients have been followed up for5.2±3.9months (3-12months), with no signs of perivalvular leakage on transthoracic echocardiography. Patients resumed work23days (median,18) following the surgery.There was no significant difference in age, sex, cardiopulmonary bypass time and aortic crossclamp time between thoracoscopic and control group (P>0.05). In the thoracoscopic group, total operation time, mechanical ventilation time, and the blood loss during the surgery was significantly less than in the control group (P<0.01). The duration of intensive care or hospital stays in the thoracoscopic group were shorter than in the control group (P<0.05). In the thoracoscopic group,13(21.0%) patients required opioid analgesics postoperatively. In the control group,25patients (75.0%, P<0.01) were administered with opioid analgesics for1-2days following the surgery.Conclussions:Totally thoracoscopic repair of VSD through a3-port entry without the aid of a robotically-assisted surgical system appears to be safe and effective. Totally thoracoscopic mitral valve replacement without a robotically assisted surgical system appears feasible and safe.The patients had gotten a better minimally invasive and cosmetology,In summary, this study evaluated the scientific thoracoscopic techniques used in repair of ventricular septal defect, mitral valve replacement are feasibility and safety.They may be promote the application of thoracoscopic techniques in cardiac surgery laid the theoretical and clinical basis and has important scientific significance. |
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