Bidirectional glenn operation without cardiopulmonary bypass: Operative protocol and early results

JOURNAL OF MEDICAL RESEARCH<br /> <br /> BIDIRECTIONAL GLENN OPERATION WITHOUT<br /> CARDIOPULMONARY BYPASS: OPERATIVE PROTOCOL<br /> AND EARLY RESULTS<br /> Nguyen Tran Thuy¹, Ngo Thi Hai Linh¹, Doan Quoc Hung²<br /> ¹Cardiovascular Center, E Hospital<br /> ²Hanoi Medical University<br /> The bidirectional Glenn (BDG) shunt operation serves as temporary treatment of single-ventricle physiology before the eventual Fontan procedure. Some cases can be performed without the support of a<br /> cardiopulmonary bypass (CPB) machine. In this study, we present the surgical outcomes of off-pump<br /> BDG operations with the use of temporary veno-atrial shunt to decompress the superior vena cava<br /> (SVC) during clamping. From June 2013 to June 2015, 23 patients underwent off-pump BDG operations at Cardiovascular Center, E Hospital. All patients were operated on using a venoatrial shunt to<br /> decompress the SVC. Satisfactory results with mean oxygen saturation increased from 79.6 ± 11.2 %<br /> to 87.2 ± 4.7 %. The superior vena cava (SVC) clamping time was 14 ± 2.4 minutes (ranging from 12<br /> to 21 minutes). No neurological complications or deaths occurred after the surgery and the postoperative period was uneventful. In conclusion, the use of venoatrial shunt to decompress SVC during<br /> the off-pump BDG operation is safe and produces good surgical outcomes. Its wider adoption can the<br /> deleterious effects associated with CPB. The operation is easily reproducible at low cost and overcome.<br /> <br /> Keywords: congenital heart disease, bidirectional Glenn operation, without<br /> cardiopulmonary bypass<br /> <br /> I. INTRODUCTION<br /> Bidirectional Glenn shunt operation is<br /> performed as the initial step in the treatment of functional single-ventricle physiology before the completion of the Fontan<br /> procedure. The purpose of this surgery is<br /> to provide balanced venous blood flow into<br /> two pulmonary arteries for oxygenation, as<br /> Corresponding author: Nguyen Tran Thuy, E Hospital<br /> Email: drtranthuyvd@gmail.com<br /> Received:09 May 2017<br /> Accepted: 16 November 2017<br /> <br /> JMR 111 E2 (2) - 2018<br /> <br /> oppoed to providing mixed ateriovenous<br /> blood, as in the Blalock – Taussig shunt surgery (aortopulmonary shunt) [1 - 3].<br /> Off-pump BDG operations without a<br /> temporary shunt to decompress the SVC<br /> will cause an elevation in the cerebral blood<br /> volume, leading to increased intracranial<br /> pressure and eventually, thereby, brain reduced blood flow to the brain and damage<br /> [3; 4]<br /> The BDG operation is conventionally<br /> performed with the support of CPB at the<br /> expense of higher cost and disadvantages<br /> 75<br /> <br /> JOURNAL OF MEDICAL RESEARCH<br /> of CPB. Therefore, globally, there has been<br /> a variety of reports on BDG operations without CPB [1; 5; 6]. The have show that in offpump BDG operation, pulmonary arterial<br /> pressure is lower and the hospital length of<br /> stay of off-pump group is shorter than that<br /> of the on-pump group [7; 8].<br /> However, there have been no official reports on this issue in Vietnam. In this study,<br /> we present the surgical protocol to perform<br /> off-pump BDG operation using the SVC-RA<br /> pressure lowering system and present early<br /> outcomes of this newly applied technique<br /> [9], [10].<br /> <br /> II. SUBJECTS AND METHODS<br /> 1. Subjects<br /> Subjects were patients who had attributes suitable for BDG operation, without<br /> any intracardiac defects requiring correction including: pulmonary artery-plasty, atrial septal extension, atrioventricular valvuloplasty, etc.<br /> 2. Methods<br /> The study disign was a retrospective observational study<br /> Patients were prepared for the survey<br /> through the following steps:<br /> - Physical examination: Clinical symptoms (evaluating the severity of heart failure, using the NYHA classification, and the<br /> level of cyanosis), SpO2, and medical history.<br /> - Laboratory tests:<br /> <br /> + Routine blood tests, electrocardiography, and chest x-ray.<br /> <br /> + Echocardiography: evaluate left<br /> ventricular function, abnormal wall motion,<br /> 76<br /> <br /> chamber size, the functional status of the<br /> heart valves, pulmonary artery (PA) size.<br /> <br /> + Cardiac catheterization: measure<br /> PA size, anatomy, pressure and resistance.<br /> - Definitive diagnosis was established<br /> based on the following: physical examination, Doppler echocardiography, cardiac<br /> catheterization, blood tests, electrocardiography and chest x-ray.<br /> - Surgical consultation, hospital admission, and preoperative medical therapy.<br /> - When all conditions had been assured,<br /> the patients underwent surgery according to<br /> the same protocol in anesthesia, operative<br /> techniques, and postoperative resuscitation. In the operating room, hemodynamic<br /> parameters were recorded.<br /> - Technical procedure:<br /> <br /> + General anesthesia, intubation.<br /> Premedication with Midazolam, Fentanyl,<br /> Rocuronium. Patients were on controlled<br /> mechanical ventilation with Vt = 150 ml and<br /> the respiratory rate of 18 per minute. The<br /> anesthesia was maintained by Isoflurane,<br /> Fentanyl, and Rocuronium. A femoral vein<br /> catheter was placed for drug distributions<br /> and monitoring of the right atrial pressure.<br /> A right internal jugular vein catheter was<br /> inserted for SVC pressure monitoring. An<br /> invasive arterial pressure line was also<br /> placed.<br /> - Surgical steps:<br /> <br /> + Whole body antiseptic application, from the chest to the legs;<br /> <br /> + Median sternotomy;<br /> <br /> + Dissect the SVC and ligate the<br /> azygos vein;<br /> <br /> + Dissect the right branch of PA,<br /> and measure PA pressure;<br /> JMR 111 E2 (2) - 2018<br /> <br /> JOURNAL OF MEDICAL RESEARCH<br /> <br /> + Set up the system to decrease<br /> SVC-PA pressure<br /> <br /> + Trial right PA clamp for several<br /> minutes to check the changes in transcutaneous oxygen saturation (SpO2). Systemic<br /> heparin with the dose of 1 mg/kg to achieve<br /> the ACT of more than 200 seconds. Set up<br /> the system to decrease SVC-PA pressure<br /> with the head of the patients elevated 15<br /> degrees, inject methylprenisolone (20 mg/<br /> kg) intravenously, SVC clamp to anstomose<br /> with right PA, maintain the difference between mean arterial pressure and mean<br /> SVC pressure during clamping higher than<br /> 40 mmHg.<br /> During surgery, hemodynamic stability<br /> was maintained by fluid replacement and<br /> inotropes: adrenaline 0.1 mcg/kg/min and<br /> Milrinone 0.3 mcg/kg/min.<br /> <br /> + Make end-to-side SVC-PA anastomosis by 7.0 prolene suture<br /> <br /> + Remove cannulae, achieve hemostasis, insert drains, electrodes, close<br /> the pericardium if possible<br /> <br /> + Close the sternotomy by steel suture, soft tissue was closed using running<br /> suture or interrupted absorbable suture in<br /> patients with high risks of infection.<br /> <br /> + In the intensive care unit, an<br /> <br /> echocardiography, routine laboratory tests<br /> (complete blood count, electrolytes, arterial<br /> blood gases, ...) were done. All complications and actions taken were recorded.<br /> <br /> + After the ICU stay, patients were<br /> transferred to Pediatric Cardiology Department for further treatment until discharge.<br /> 3. Ethics<br /> All study procedures complied with the<br /> ethical principles of biomedical research.<br /> Participants consented to take part in the<br /> study and were told that they could withdraw at any time. Participants’ information<br /> was kept secure and confidential.<br /> <br /> III. RESULTS<br /> From June 2013 to June 2015, we performed off-pump BDG operation on 23 patients. The mean SVC clamp time was 14 ±<br /> 2.4 minutes (ranged from 12 - 21 minutes).<br /> During clamping, the mean central venous<br /> pressure ranged from 24 to 40 mmHg (average 31.5 ± 6.1 mm Hg). Preoperative PA<br /> pressure ranged 11 - 25 mmHg (average<br /> 16.3 ± 3.2 mmHg). There was no conversion to CPB machine.<br /> Indications of patients undergoing BDG<br /> operations are summarized in Table 1.<br /> <br /> Table 1. Indications of patients undergoing BDG operations<br /> Other surgeries<br /> <br /> Patients (n)<br /> <br /> Percent (%)<br /> <br /> Single-ventricle physiology<br /> <br /> 11<br /> <br /> 47.8<br /> <br /> Double outlet right ventricle with transposition of the great<br /> arteries<br /> <br /> 5<br /> <br /> 21.7<br /> <br /> Transposition of the great arteries, pulmonary stenosis,<br /> large ventricular septal defect<br /> <br /> 6<br /> <br /> 26.2<br /> <br /> Atrioventricular disassociation, double outlet right ventricle<br /> <br /> 1<br /> <br /> 4.3<br /> <br /> JMR 111 E2 (2) - 2018<br /> <br /> 77<br /> <br /> JOURNAL OF MEDICAL RESEARCH<br /> Early results<br /> The mean ventilator time after surgery was 2.6 ± 1.2 hours (1 - 6 hours), the ICU length<br /> of stay was 13.2 ± 3.1 (10 - 18 hours); no death occurred. Echocardiography evaluation at<br /> discharge showed no anastomosis stenosis, and postoperative electrocardiography (ECG)<br /> revealed no arrhythmia.<br /> Mean postoperative PA pressure was 13.6 ± 2.5 mmHg.<br /> Table 2. Postoperative complications<br /> Complications<br /> <br /> Patient (n)<br /> <br /> Percent (%)<br /> <br /> Chylothorax<br /> <br /> 1<br /> <br /> 4.3<br /> <br /> Pneumonia<br /> <br /> 2<br /> <br /> 8.6<br /> <br /> Pulmonary effusion requires drainage<br /> <br /> 1<br /> <br /> 4.3<br /> <br /> Surgical wound infection<br /> <br /> 1<br /> <br /> 4.3<br /> <br /> Reoperation<br /> <br /> 1<br /> <br /> 4.3<br /> <br /> Neurological deficits<br /> <br /> 0<br /> <br /> 0<br /> <br /> Reoperation due to thrombus at the Glenn anastomosis<br /> Table 3. Pre and postoperative Hct, SpO2<br /> Parameters<br /> <br /> Preoperative<br /> <br /> Postoperative<br /> <br /> p<br /> <br /> Hct (%)<br /> <br /> 0.53 ± 0.11<br /> <br /> 0.43 ± 0.05<br /> <br /> 0.001<br /> <br /> SpO2 (%)<br /> <br /> 79.96 ± 11.2<br /> <br /> 87.2 ± 4.7<br /> <br /> 0.011<br /> <br /> The hospital length of stay ranged from<br /> 6 to 9 days (average 7.1 ± 1.3 days). Echocardiography showed no significant pressure gradient through the SVC-RPA anastomosis and also showed good velocity<br /> of blood flow; ECG showed normal sinus<br /> rhythm in all patients, and no neurological<br /> complications were recorded.<br /> <br /> IV. DISCUSSION<br /> Several studies have documented the<br /> decrease in oxyhemoglobin in brain tissue,<br /> a 50% reduction in blood flow in the middle cerebral artery with significant changes<br /> <br /> 78<br /> <br /> in encephalography. Rodriguez found that<br /> clamping the SVC decreases the systolic<br /> pressure of cerebral arteries and subsequently decreases the brain's oxygen supply [2 - 4]. To avoid these complications<br /> many studies have reports on the used a<br /> temporary shunt to decompress the SVC<br /> and improve perfusion of the brain.<br /> Table 4 is summary of all studies in the<br /> past 15 years examining BDG operations<br /> without CBP. Lamberti polished his research<br /> on seven patients in 1990 and subsequently, there was a series of other studies examining off-pump BDG surgery [1; 5; 9].<br /> JMR 111 E2 (2) - 2018<br /> <br /> JOURNAL OF MEDICAL RESEARCH<br /> Table 4. Studies on off-pump BDG surgery<br /> Study<br /> <br /> Year<br /> <br /> Number of study<br /> patients<br /> <br /> Temporary shunt<br /> <br /> Lamberti<br /> <br /> 1990<br /> <br /> 7<br /> <br /> SVC – RA<br /> <br /> Lal<br /> <br /> 1996<br /> <br /> 6<br /> <br /> SVC – RA<br /> <br /> Murthy K S<br /> <br /> 1999<br /> <br /> 5<br /> <br /> SVC – PA<br /> <br /> Jahangiri<br /> <br /> 1999<br /> <br /> 6<br /> <br /> No<br /> <br /> Villagra F<br /> <br /> 2000<br /> <br /> 5<br /> <br /> No<br /> <br /> Tiereli<br /> <br /> 2003<br /> <br /> 30<br /> <br /> SVC – RA/PA<br /> <br /> Maddali<br /> <br /> 2003<br /> <br /> 2<br /> <br /> SVC – RA<br /> <br /> Liu<br /> <br /> 2004<br /> <br /> 20<br /> <br /> SVC – RA/PA<br /> <br /> Luo<br /> <br /> 2004<br /> <br /> 36<br /> <br /> SVC – RA<br /> <br /> Maeba<br /> <br /> 2006<br /> <br /> 18<br /> <br /> SVC – RA/PA<br /> <br /> Kotani<br /> <br /> 2006<br /> <br /> 14<br /> <br /> SVC – RA<br /> <br /> Hussain<br /> <br /> 2007<br /> <br /> 22<br /> <br /> No<br /> <br /> Kandakure<br /> <br /> 2010<br /> <br /> 218<br /> <br /> SVC – RA<br /> <br /> 13 studies<br /> <br /> 389<br /> <br /> Total<br /> <br /> RA: right atrium; PA: pulmonary artery; SVC: superior vena cava<br /> (Until now, there have been no official reports on this technique in Vietnam).<br /> In the study of Ulisses Alezandre Crotti, the mean age of on-pump group was 66 months<br /> and that of off-pump group was 50 months (p = 0.17 using Mann-Whitney test). This suggests the differences in age, gender, weight, types of defects between on-pump and off-pump<br /> group are not important factors in choosing the use of peripheral circulation.<br /> The choice of a temporary shunt depends on the experience and ability of the surgeons,<br /> and anesthegist, as well as the conditions of the surgical center. Our technique uses a temporary veno-atrial shunt with the following steps: placing a venous graft at the junction of SVC<br /> and azygos vein, which effectively decreases the pressure of the clamped SVC and avoids<br /> the possibility of SVC stenosis. In addition, the head-elevated position during operation facilitates the adequate decompression of SVC and provides enough space surgical.<br /> <br /> JMR 111 E2 (2) - 2018<br /> <br /> 79<br /> <br />