The Clinical Study Of Conal Ventricular Septal Defect Surgery Through Left Anterior Minithoracotomy

Objective This study is to evaluate the safety and effectiveness of conal ventricular septal defect(VSD)surgery through left anterior minithoractomy.Methods1.Clinical DataA retrospective study was carried out in General Hospital of Jinan Military Region from Apr.2014 to Sep.2016.29 patients(Test group)with conal ventricular septal defect(VSD)were underwent correction through left anterior minithoracotomy,involving 15males and 14 females,that median age(4.9±3.2)years old(From 3years to 12years old)and median weight(17.5±4.3)kilogram(From 15 to 47kilogram).The main corrected defect was single conal VSD.30cases,who underwent conal VSD correction through the median sternotomy from Apr.2012 to Mar.2014 by the same surgical team,were selected as control group.2.Surgical TechniquesThe patient was in the supine position with the left pad 15-20 degree.The external defibrillation electrodes were put on the right anterior and the left posterior chest.After induction of general anesthesia,a single lumen endotracheal tube was placed.When the left chest was open,we used the respiration principle of low tidal volume and high frequency synchronization to keep the oxygen saturation above 98%.Peripherally Cardiopulmonary bypass(CPB)was established through femoral arteries and veins.In test group,19cases used unipolar porous femoral venous cannula,and combined with superior vena cava cannulation.Two basic small incisions were made on the left chest.The 1st incision(about 4cm to 6cm)was a main operation access in the 3rd intercostal space on left prothorax.The 2nd one(about 1cm to 1.5cm)was located in the 7th intercostal space on left midaxillary line and used for the entry of left drainage tube and carbon dioxide flow pipe,that was also an access for thoracic drainage tube after surgery.In addition,the 3rd incision(about 1cm to 2cm)was selectivity located in the 2nd intercostal space between right midclavicular line and lineae parasternalis,used as an access for Superior vena cava cannulation,Chitwood aortic cross-clamp and Infusion needle.Correction of cardiac malformations:Aortic cross-clamp was placed and the myocardial protective fluid was infusion by an antegrade cardiopledia needle on ascending aorta.The upper and inferior vena cava was blocked after perfusion.The transverse incision was made on main pulmonary artery to expose conal VSD via the 1st incision.The VSD was closed with Gore-Tex patch by intermittent suture.Someone with PDA should be ligated before CPB via the 1st incision too.3.Preoperative Management3.1 Education and counseling on surgical techniques were provided before the study.Informed consent was obtained from all participants and there parents at the same time.Personal history of the disease was asked in details,especially on lung disease,left chest surgery,and pleurisy.The chest X-ray,Echocardiography and Intravascular Ultrasound Doppler examination were routinely performed before surgery.3.2 The respiration principle of low tidal volume and high frequency synchronization was used when the left chest was open.The lung was covered by wet gauze to avoid direct instrument injury,and was inflated every 20 min during the operation.The VSD residual shunt and left ventricular system ventilation were assessed by Transesophageal Echocardiography(TEE).The blood oxygen saturation and skin color of the lower extremities of the femoral vein cannula was observed carefully during the whole operation.3.3 The early mechanical ventilation was controlled by pressure controlled model(PC model)with PEEP 2-5cmH2O.When the patient recovered from anesthesia with hemodynamic stability,Synchronized Intermittent Mandatory Ventilation model(SIMV model)was used for Practice autonomous respiration.Tracheal intubation was removed after sufficiently Sputum suction without abnormality found in arterial blood gas analysis.Aspirin was taken orally by 3-5 mg/kg·day for 3months.Encourage patients to exercise early,especially for the lower limbs.4.Observation indexThe mortality and complications of two groups were counted.The operation time,CPB time,aortic cross clamp time,postoperative ventilator assistance time,ICU time,postoperative hospitalization time and flow volume 12 hours after operation were analyzed statistically in two groups.During the follow-up,Electrocardiogram,chest X-ray,Echocardiography,Intravascular Ultrasound Doppler of lower limbs were performed routinely.ResultsAll cases obtained successfully operative procedure without death.There were no significant differences(P>0.05)between the two groups in terms of age,sex ratio,weight,and the time of aortic cross-clamp.In test group,the ICU time were shorter than that of the control group,but that difference was no statistically significant(p=0.063).In the compare with control group,the operation time and the CBP time were longer,and the mechanical ventilation time,the postoperative hospitalization time and the volume of pleural drainage for 12 hrs after operation were shorter than that in test group.That difference was statistically significant(P<0.05).Complications in test group include:2 cases(6.9%)of hemoglobinuria,3 cases(10.3%)of subcutaneous emphysema on left chest and 3 cases(10.3%,weight lower than 20kg)of the lower limb swelling after femoral arterial and venous cannulation.Intravascular Ultrasound Doppler showed that the diameter of the femoral veins were moderately narrow and blood flow was obviously accelerated.In control group,5 cases(16.7%)of thoracocyllosis were found in follow-up.No other complications occurred.ConclusionsWe evaluated that the left anterior minithoractomy of conal VSD surgery has the same safety and effectiveness as the traditional sternotomy approach.This study provides valuable experiences and clinical ideas for the minimally invasive cardiac surgery via left minithoractomy approach,and has important scientific significance.