1 case of anaesthetic management of ultrasound-guided heart-tip path through catheter aortic valve placement.

. Transcatheter aortic valve implantation (TAVI) is currently a new treatment for patients with high-risk severe aortic valve stenosis (As) due to the low trauma and the absence of in vitro circulation and open chest surgery. TAVI path has a variety of paths, such as transverse artery path TAVI (Transfemoral TAVI, TF-TAVI) and trans-tip path TAVI (Transpreort TAVI, TA-TAVI) and so on, in which TA-TAVI is directly simple due to the surgical path, avoiding peripheral
vascular
damage and reduce the risk of arterial plaque loss, often used in peripheral artery diameter, severe calcification and distortion of AS patients. Due to the operation of TA-TAVI, left ventrin altin puncture tube and other operations, perfect anaesthetic
management
is an important factor in the success of surgery. The hospital's first TA-TAVI
management
is reported.

. 1.
clinical
datapatient, male, 62 years old, admitted to hospital for "27 years after two-tip valve replacement surgery, and then heart palpitations, shortness of breath for 10 months". Ultrasound examination: post-double-tip valve replacement; aortic valve calcification, mild stenosis with severe reflux, reflux area 7.3 cm2; aortic valve cross-valve pressure difference of 41mmHg, aortic valve flow rate 277 cm/s, left ventricular ejecation score (Left ventr ejection, LVEF) 43%.

electrocardiogram examination: sinus heart rate, complete left beam conduction block, ST-T change. There were no obvious abnormalities in the coronary artery angiography, and the chest abdominal aortic CT
angiology
the angiography suggested the formation of peripheral artery calcified plaques, accompanied by mild stenosis in the tube cavity. Brain-type urethra excretion peptide (BNP) 503pg/mL, the rest of the blood biochemical laboratory tests did not show significant abnormalities. Admission
diagnosis
: rheumatic heart disease, two-tip valve replacement surgery, AS companion closed incomplete, complete left beam conduction block, peripheral atherosclerosis plaque formation, heart function III. After admission to the hospital to take oxygen absorption, strong heart and diuretic support treatment, proposed in the trachea intubation general anesthesia downstream TATAVI surgery.

. TA-TAVI is performed in the operating room and is used in the middle of the procedure for the in vitro circulation machine. Patients are routinely monitored with electrocardiograms (ECG), oxygen saturation (SpO2), placed in vitro defibrillator electrodes, and used a temperature-changing blanket to keep warm. The first 15min of anesthesia induction was given to the right metadomide intravenously (load dose 1 ?g/kg, maintained at 0.5 ?g.kg-1-h-1 after the injection of the 15min pump), 1% Lidoca in local anaesthetic lower left arterial puncture, monitoring of invasive artery blood pressure, while using the FloTrac/Cardiao system to monitor the patient's blood volume (g-d, cell) and per-rate variation. Intravenous midazolam 0.08mg/kg, relientine 0.2mg/kg and Suffintani 0.4 sg/kg for anaesthetic induction, intravenous lychee of rhocomine ammonium 1.2mg/kg for trachea intubation to moisture Volume 10mL/kg, breathing rate 13 times/min, I:E 1:2 and exhalation of the end of positive pressure ventilation (Positive endendatory pressure, PEEP) - 5 cm H2O for mechanical ventilation, and according to arterial blood gas analysis results to adjust the respiratory parameters.

tracheal intubation and placed in the esophagus ultrasound probe through the esophagus, monitored by Transesophageal echocardiography (TEE), and placed a temperature probe in the nasopharynx for temperature monitoring. Intravenous pump propofol 2 to 4 mg kg-1 h-1 and riffinteni 0.05 to 0.10 sg.kg-1.min-1, while inhalation of heptafluoroethertheration 1% to 2% maintenance of anesthesia, Narcotrend value at 40 to 60. The right intra-cervical venous puncture, the monitoring of central venous pressure (CVP) and the pump injection of vascular active drugs, and the 5F vascular crucible sesame are placed to place temporary pacemaker electrodes at the tip of the right ventricle.

continuous intravenous infusion lidocain 1 mg kg-1 h-1, maintaining blood K plus concentration of 5.0 to 5.5mmol/L. Infusion of the appropriate amount of crystal fluid and colloidal fluid to maintain CVP 8 to 12mmHg and SVV 13%. Intravenous infusion of deoxyrepinephrine and norepinephrine maintain hemodynamic stability. Give heparin 1mg/kg before placing a temporary paceelectrode to maintain a full blood-activated coagulation time (Activated clotting time of whole blood, ACT) by 300s. Before the aortic cyst distates dilate and place the artificial aortic valve, a temporary pacemaker is applied for rapid ventrpacing (Rapidventr pacing, RVP) with a pacing heart rate of 180 times per minute. Before RVP, patients with blood pressure 111/60 (77) mmHg, a brief drop in blood pressure after RVP, the lowest mean arterial pressure (Mean arterial pressure, MAP) is 30mmHg, duration is less than 10s, intravenous opiate oppherin 50 sg, valve after successful cessation of RVP, blood pressure recovery to 99/59 (72) mmHg.

when the valve is fully released, the aortic root angiography and TEE examination confirmed that the valve position is satisfactory, the opening state is good, there is no obvious valve peripheral leakage, the aortic valve cross-valve pressure difference of 8mmHg, the aortic valve flow rate 138 cm/s. After the valve is placed, the appropriate deepening of anesthesia, intravenous continuous pumping nikatiflat 2 to 6 sg kg-1 min-1 control blood pressure, maintain systolic pressure 90 to 110mmHg, fish essence protein 1:1 and heparin. Blood loss in the operation using
blood
recovery machine for self-blood transfusion. Before closing the incision, postoperative analgesia is performed with 0.5% roptopainin for local immersion and interribal nerve block around the incision.
. After the operation, the patient is admitted to the intensive care unit (Intensive care unit, ICU). The operation lasted 180min, during the operation blood loss 500mL, urine volume of 300mL, recovery of blood volume 332mL, infusion volume of 1,700mL. In the operation, RVP was 2 times, the aortic valve balloon dilated 1 time, the duration was 10s, and the blood pressure dropped sharply during the artificial aortic valve, and the hemodynamics of the patients were more stable. After the operation, the patient removed the trachea catheter 3h, 48h after the operation, 3d turned out of the ICU after surgery. Patients developed a burst
atrial fibrillation
5d after surgery, and were treated with amine iodone. After surgery 7d removed the right ventricle temporary pacemaker electrode, cardiac ultrasound indicates that the artificial aortic valve position and function is normal, the aortic cross-valve pressure difference of 14mmHg, the aortic valve flow rate 188 cm/s, LVEF 53.4%. BNP244pg/mL, significantly improved compared to preoperative surgery, the patient was discharged from the hospital 13d after surgery, a total of 22d in hospital.

. 2. DiscussionTA-TAVI surgery due to the operation of the catheter does not pass through the peripheral artery, aortic arch, aorta and aortic valve, shorten the surgical entry, for TAVI to provide a more stable platform, and TEE examination can obtain accurate valve image, can reduce the amount of contrast agent in surgery. However, TA-TAVI surgery requires chest opening and left ventricle perspiration, with varying degrees of heart muscle injury, accompanied by various arrhythmia, high risk of bleeding, easy to cause heart rupture and heart congestion and other serious complications. Therefore, TA-TAVI on the patient's degree of cooperation requirements are high, generally choose trachea intubation general anesthesia. Although single-lung ventilation was used early in TA-TAVI surgery, it is currently considered unnecessary and single-lung ventilation may further worsen cardiopulmonary function in AS patients.

in addition, due to the poor heart function of this type of patient, as far as possible to choose the circulation function of less the anesthetic drugs, anesthesia maintenance can use short-acting narcotic drugs, with a view to the early removal of trachea catheters, reduce mechanical ventilation-related complications. In addition to routine ECG, SpO2, body temperature and invasive arterial blood pressure monitoring, monitoring CVP and SVV can guide fluid management during surgery and improve patient prognosis. TEE monitoring during TA-TAVI surgery helps surgeons confirm the position of the left ventricle tip, ensuring that the guide wire or catheter is not entangled in the two-tip flap during operation, and avoids causing severe biptoludes.

. TEE monitoring can also assess the preoperative and postoperative aortic valve condition, monitor cross-valve pressure difference, early detection of valve leakage, coronary artery opening blockage, aortic mezzanine and ventricular wall movement abnormal complications, timely treatment or replacement of surgical methods. In addition, in vitro defibrillation electrodes need to be prepared, can start at any time cardiopulmonary reflux or coronary artery stent placement, etc. The core of anesthesia management is to maintain hemodynamic stability and regulate the target blood pressure according to the surgical process. PATIENTS WITH AS USUALLY HAVE THICKENED LEFT VENTRICLES AND GOOD CARDIOMYOSY CONTRACTION FUNCTION, DURING SURGERY, ACONTROLLING DOSES OF NOREPINEPHRINE OR DEOXYREPINE CAN BE USED TO MAINTAIN THE SPREAD OF THE AORTIC VALVE CROSS VALVE PRESSURE. For patients with significantly impaired heart function, small doses of positive muscle drugs such as dopamine, milinon, etc. can be used.

in the left ventricle tip stitching and puncture tube process, can use Lidocain, right metomimidin and other to reduce heart stress, while preventing elevated blood pressure, to avoid increasing the risk of bleeding and heart muscle tearing. The aortic valve expansion and the temporary pacing required before placing the artificial aortic valve, RVP can cause ineffective contraction of the ventricle, reduce the left ventricle blood, has the role of stable expansion of the balloon and valve stent, can reduce the risk of valve displacement. Usually using the right ventricle to place pacing electrodes or the surface of the heart stitched pace wire for pacing, pacing heart rate of 160 to 220 times / minute, so that the systolic pressure is less than 70mmHg and pulse pressure is less than 20mmHg.

. After RVP, patients need to immediately restore circulation, maintain hemodynamic stability, most scholars recommend that before RVP to maintain MAP -75mmHg, at the same time should limit the pace time and frequency, to avoid causing coronary artery perfusion, leading to malignant arrhythmia and so on. During RVP, sharp hemodynamic deteriorations, such as positive muscle support, ventricular pacing and defibrillation, and even the establishment of emergency in vitro circulation, need to be dealt with in a timely manner. This case patients carried out 2 RVP, after the balloon expansion of the blood pressure heart rate soon returned to normal, but in the valve placement process, there is a short cardiac arrest, blood pressure drop sharply, quickly give deoxyrepineande and speed up infusion, after the valve placement completed and stop pacing, the heart rate blood pressure returned to normal. Beware of complications during surgery.

due to as-aus patients' valve calcification or other reasons, the balloon dilation and valve placement process may lead to coronary artery obstruction, low blood pressure, and even cardiac arrest. Therefore, it is important to evaluate the distance between the patient's coronary artery opening and the aortic valve, the degree of calcification of the valve and the placement position of the valve before operation. At the same time, before and after the operation, the coronary artery should be anotothed to eliminate coronary artery obstruction. In addition, if the valve position is too low, can cause the opening of the two-tip valve open restriction, resulting in the medical-derived two-tip valve narrow. If the valve position is too high, there may be no action on the valve. In addition, the valve model selection should also be appropriate, if the model is too large may cause the left beam branch conduction block or even heart rupture, the model is small or the patient's own valve calcified plaque can lead to the release of the valve incomplete, causing the valve peripheral leakage and other complications. Therefore, the assessment of the perinatal TEE is very important to assess the degree of valve opening, the presence of the biceps and the absence of valve leakage, heart bag filling and other complications.

, ta-TAVI surgery patients have a high erythnotic risk of bleeding. It is believed that heart-tip path, low body mass and coronary artery disease are independent risk factors for severe bleeding after TAVI surgery. Some scholars believe that TATAVI surgery patients are generally not suitable for TF-TAVI surgery, most patients combined such as
myocardial infarction
or peripheral artery disease, have a high Logistic EuroSCORE score, and these factors can increase the risk of bleeding.

, if the blood pressure can increase ventricular wall tension before the valve is placed, it will lead to bleeding, tearing of the left ventricle tip, increased risk of myocardial mezzanine and the formation of pseudo-aneurysm. During operation, if the end of the left front caliper artery is damaged, it can cause ischemia at the tip of the heart, causing the suture to crack. In addition, after the successful placement of artificial aortic valve, left ventricular ventricular obstruction symptoms immediately alleviated, the aortic valve cross-valve pressure difference significantly reduced, may cause blood pressure to rise rapidly, increase the risk of bleeding, easy to cause heart bag filling, and even the risk of ventricular rupture, at this time need to deepen anesthesia, the appropriate use of vascular dilation drugs such as nikado equality.
. The incidence of cardiac conduction block after TA-TAVI was 7.0% to 13.6%, significantly lower than TF-TAVI, and most heart conduction abnormalities can occur during or after surgery, the literature reported. However, the incidence of
atrial fibrillation
was significantly higher in patients with TA-TAVI than in TF-TAVI patients.

it has been reported that epidural analgesia can reduce the incidence of postoperative atrial fibrillation in patients with TATAVI. In this case, patients in 5d after surgery atrial fibrillation, amine iodone after the drug re-discipline of the heart rhythm to sinus, after surgery did not occur chamber conduction block, after surgery 7d successfully removed the right ventricle temporary pacife electrode. The goal of postoperative management is to improve postoperative analgesia, reduce mechanical ventilation time and early sleep activity, and reduce postoperative complications.

routine intravenous self-controlled analgesia may affect the hemodynamic stability of patients. Epiphany analgesia may increase the risk of bleeding due to postoperative anticoagulant therapy.