Study On The Treatment Of Subarterial Ventricular Septal Defect Between The Left Anterior Thoracic Small Incision And The Sternal Median Incision

OBJECTIVE:To summarize the clinical experience and effect analysis of the left anterior thoracic small incision in the treatment of subarterial ventricular septal defect（VSD）,and to compare it with the sternal median incision.Research method:1.Clinical dataFrom September 2012 to January 2017,there are 61 cases of subarterial septal defect were treated with a small incision in the left anterior chest,which was set as the minimally invasive group.There were 32 males and 26 females in this group.The mean age was5.26±2.76 years（range,3.0-12.0）and the mean body weight was 20.70±8.52kg（range,15.0-42.0）.There are 55 cases of subarterial septal defect were treated with conventional median sternotomy incision in the same period,which was set as the conventional group.There were 32 males and 23 females in another group.The mean age was 4.80±2.54 years（range,1.0-14.0）and the mean body weight was 18.82±8.36kg（range,9.0-46.0）.The main cardiac malformations in the two groups were subarterial ventricular septal defect.In the minimally invasive group,8 patients had patent ductus arteriosus（PDA）,10patients had mild aortic valve prolapse,and 13 patients had severe pulmonary hyperten-sion（PH）.In the conventional group,8 patients had patent ductus arteriosus,26 patients had atrial septal defect（ASD）,15 patients had mild aortic valve prolapse,and 37 patients had severe pulmonary hypertension.2.Surgical methodsThe patients In the minimally invasive group were positioned in a 20 degree left lateral decubitus position,with the left arm outreached 15-20 degree.After the induction of general anesthesia,a single-lumen endotracheal tube was placed for double lung ventilation.And then,a transesophageal echocardiography probe was inserted to monitor the VSD closure.Cardiopulmonary bypass（CPB）was established peripherally through femoral vein and femoral arteries.The operations were performed by a left anterior parasternal mini-thoracotomy,through the third intercostal space,with a short incision about 4cm in length.An incision for thoracic drainage tube was located in the seventh intercostal space on the left midaxillary line and used for the entry of a left atrium drainage tube and a carbon dioxide flow pipe.The left atrium drainage tube was inserted into left atrium through an incisionog in left atrial appendage.The PDA in some patients was ligated through the third intercostal before commencing cardiopulmonary bypass.Caval snares were placed in the superior and inferior vena cava after commencing cardiopulmonary bypass.The aortic crossclamp was palaced on the ascending aorta,and the perfusion needle was inserted to the aortic root for the delivery of cardioplegic solution to achieve cardiac arrest.The transverse incision was made on main pulmonary artery to expose subarterial ventricular septal defect.A Gore-Tex patch was used to repair subarterial ventricular septal defect by intermittent suture.After VSD closure,the lungs were over-ventilated,in order to judge the leakage.The pulmonary artery was closed by 5-0 or 6-0prolene,and the air was exhaust from the heart.The patient was rewarmed,and the aortic crossclamp was released,and then the heart beating agin.Transesophageal echocardiography confirmed that there were no residual shunts or intracardiac air bubbles.The blood was rewarmed,and there were nothing unusual.And then,the left atrium drainage tube and the femoral vein drainage tube were removed.Checking the heart and chest incision,there was no blood lossed.The thoracic cavity was closed layer by layer,and and the closed thoracic drainage tube was placed.After the femoral artery tube was pulled out,the femoral artery and femoral vein incision were sutured with the 6-0 prolene lines to avoid stenosis.After the skin was sutured,the surgery was over.3.Preoperative Management（1）The preoperative education was performed on patients and their families,to understanding of the operation.Careful medical history and the chest X-ray or CT exa-mination were performed,to exclude the lung diseases.Bilateral femoral artery and vein were assessed by colour Doppler ultrasound to rule out vascular stenosis and deformities.（2）After the left chest opened,the respiration method of high frequency and low tidal volume was used.The lung were inflated every 15-20minute during the operation to ensure ventilation and avoid carbon dioxide accumulation.The left lung was surfaced by a wet gauze to avoid the contactted damage.Transesophageal echocardiography（TEE）was used to evaluate the surgical outcome.（3）Postoperative,the mechanical ventilation was controlled by volume controlled mode（VC）,with positive end expiratory pressure（PEEP）3-6cm H₂O,and tidal volume（VT）10-15ml/kg.The ventilator parameters were adjusted according to blood gas analysis results.The chest X-ray was routinely perfoemed at the bedside in the intensive care unit（ICU）as soon as possible,to observe the tracheal intubation,and to exclude complications in the lungs.The tracheal intubation was removed by the mode of Synchronous Inter-mittent Command Ventilation（SIMV）after hemodynamic stabilization.And the mechani-cal ventilation time was minimized.We encouraged patiens to sitting on the bed and walking on the ground as earlier as they could.Aspirin was eatted by 3-5mg/kg everyday,to prevent stenosis of the femoral artery.4.Observation indicatorsThe mortality and complications,the operation time,the CPB time,aortic cross clamped time,ICU time,flow volume,analgesic used rate of two groups were counted.Result:All the 116 patients obtained successfully operative without secondary surgery or death.There were no significant differences in the basic clinical data between the two groups in terms of age,sex ratio and cardiothoracic ratio.The extracorporeal circulation time（47.42±9.29min）in the minimally invasive group was slightly longer than that in the control group（40.35±7.12min）.The amount of bleeding,mechanical ventilation time,analgesic use rate,postoperative drainage volume,and hospitalization time in minimally invasive group were better than the other.In both groups,there was no significant difference in aortic occlusion time.There were no perioperative death and residual shunt in all the cases.During the follow-up period from 12 to 36 months,in the minimally invasive group,there was no asymmetry of mammary gland development,no scoliosis and chicken thoracic deformity,when 4 cases of chicken thoracic deformity in the control group.Conclusions:Our experience demonstrates that subarterial VSD can be safely closed with patch through left anterior thoracic small incision,and it has the advantage of being minimally invasive and cosmetology.This study evaluated the scientific of the left anterior thoracic small incision used in repair subarterial ventricular septal defect is effectiveness and safety.It laid a theoretical and clinical basis for the application and promotion of the left anterior thoracic small incision in cardiac surgery,and has important clinical application value.