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15MEDICAL SCIENCES
COMPARATIVE ANALYSIS OF THE EFFECT OF THE NEUROTROPHIC FACTOR BDNF AND CHONDROTINASE ABC, MESENCHYMAL STEM CELLS IN THE HYDROGEL ON THE REGENERATION OF THE SPINAL CORD OF RAT WITH AN EXPERIMENTAL TRAUMA.
Akshulakov S.
MD, Professor,
"National Centre for Neurosurgery" JSC, Astana, Kazakhstan
Kerimbayev T.
MD,
"National Centre for Neurosurgery" JSC, Astana, Kazakhstan
Aleinikov V.
"National Centre for Neurosurgery" JSC, Astana, Kazakhstan
Smagul Zh.
"National Centre for Neurosurgery" JSC, Astana, Kazakhstan
Ogay V.
"National Centre for Biotecnology" JSC, Astana, Kazakhstan
ABSTRACT
Purpose. To investigate the effect of hydrogel containing brain-derived neurotrophic factors and chon-droitinase ABC, mesenchymal stem cells to the regeneration of experimental spinal cord injury of rats.
Objectives. To determine the pathomorphological and functional efficacy of an anastomosis of the damaged area of the spinal cord of experimental animals using the peripheral nerve autograft imbibrated by neurotrophic factor BDNF, chondrotinase ABC, mesenchymal stem cells in the hydrogel.
Methods. The studies were performed on 30 outbred male Wistar rats weighing 180-200 grams, age not less than 5-6 months. The experimental protocol used in the work was approved by the Ethics Committee of the National Centre for Neurosurgery in Astana. The autograft of the femoral nerve imbibrated with hydrogel containing the neurotrophic factor BDNF and chondrotinase ABC, mesenchymal stem cells, was placed in the spinal cord crushing site. Efficacy was assessed at 1, 15, 30 and 60 days after surgery, the neurological deficit was determined on a scale, and locomotor dysfunction with the help of the Locomotor Rating Scale.
Results. Analysis of the results of the Basso-Beattie-Bresnahan (BBB) Locomotor test, the ASIA/Frankel neurological deficit at 1, 15, 30, 60 days, showed restoration of the lost functions in the experimental group, whereas in the control group, all the animals operated on by this method were marked with a neurological deficiency type A, with complete loss of motor function. The locomotor test, assessment of the neurological deficit were performed at the same time, in the control and main groups. The pathomorphological picture showed signs of white substance regeneration in the zone of spinal cord injury.
Conclusion. The results of the study testify to the prospects of using an autograft of a nerve with a hydrogel containing neurotrophic factor BDNF and chondrotinase ABC, mesenchymal stem cells in combined therapy for severe spinal cord trauma.
Keywords. Spine trauma, spinal cord, regeneration, allograft, hydrogel.
Introduction
Spinal cord injury (SCI) is one of the most destructive injuries and can lead to severe sensory and motor deficits with many severe complications. Currently, drug therapy, recommended for the treatment of traumatic spinal cord injuries, is used with a noticeable, but unfortunately limited success [1]. One of the main obstacles to the restoration of the function of the spinal cord is its low ability to regenerate. In addition, in acute trauma adult axons do not grow as quickly as young, chronically damaged axons are even more prone to disruption of regeneration, they need additional stimulation, for example, exogenous neurotrophins, to spur the regenerative response. An
obstacle to successful regeneration is the glial scar, which forms immediately around the lesion. Reactive astrocytes, fibroblasts, and NG2 + progenitor cells within the scar quickly activate the production of inhibitory molecules, including several chondroitin sulfate proteoglycans (CSPG), which may play a key role in the low regenerative capacity of damaged nerve cells. Previous laboratory studies have shown that the treatment of spinal cord injury in the form of hemisection with neurotrophic factors, including glial cell line-derived neurotrophic factor (GDNF) and the brain-derived neurotrophic factor (BDNF), by inserting peripheral nerves into the lesion cavity, was accompanied by a positive regulation of the growth of
proteins associated with regeneration and contributed to an increase in the number of axons regenerating into the grafted nerve [2, 3]. A number of preclinical studies have shown that bone marrow transplantation of MSC to rats with spinal cord injury accelerates restoration of axons and certain functions [8]. For a sustained release of neurotrophic factors in the damage zone, a biological reservoir containing neurotrophic factors and serving as a matrix for the proliferation of axons is needed. At present, tissue engineering is one of the most promising areas of research in connection with its potential for the regeneration of damaged or non-viable tissues. One of the most suitable biopolymers for this purpose, of course, are natural hydrogels [9]. Hydroalgens based on hyaluronic acid, such as the combination of MC and HA, are of particular interest, since they are biodegradable, non-toxic and can be injected into the damaged spinal cord. Because of their mechanical characteristics and biological functions, hydrogels based on HA can be used to create biocompatible scaffolds in the engineering of nerve tissue. This hydrogel may contain neurotrophic factors and cells or release molecules of anti-inhibitors such as thermostabilized chondrotinase (ChABC) into the damaged portion of the spinal cord. Thus, hydrogel based on HA have properties that are favorable for their application to the regeneration of damaged nervous tissue. However, these strategies are currently limited to poor animal survival and uncontrolled differentiation of transplanted stem cells.
The aim of the study was a comparative study of spinal cord regeneration through a peripheral nerve autograft implanted with a hydrogel with the neurotrophic factor BDNF and chondrotinase ABC, mesenchymal stem cells with an experimental spinal cord trauma.
Materials and methods
Study design
The experiments were performed on 50 outbred male Wistar rats weighing 180-200 grams, age not less than 5-6 months, which were purchased from the nursery of laboratory animals "Pushchino" (Russia). Animals are kept in vivarium conditions including a 12hour day/night cycle, at a temperature of 22-25 ° C. The study was conducted from 2015 to 2017. The preparation of stem cells and hydrogel was carried out on the basis of the stem cell laboratory of the RSE National Center for Biotechnology. All measuring instruments and test equipment used in the conduct of scientific research passed the verification and certification procedures in the relevant accredited bodies - JSC "National Center for Expertise and Certification" and RSE "Kazakhstan Institute of Metrology". The surgical stage was carried out on the basis of the RSE "National Center for Biotechnology" in Astana.
Description of intervention
The rat was placed in an induction chamber, where isoflurane (5% isoflurane with a flow rate of 2.0 l / min) was supplied with inhalation anesthesia. After the rat was placed on the operating table, then the expected operating field was shaved. An inhalation cone was placed on the nose and mouth of the rat, the isoflurane
concentration decreased to 3%, the flow rate increased to 3.0 liters/minute. The T12 vertebra was determined at the insertion level of the last rib. A rostral part of this vertebra was marked with a line passing through the spinous processes T11, T10, T9. An incision on this line had been made. Skin, together with subcutaneous fat, was diluted with a retractor. The superficial fascia was cut before exposing the supraspinal muscles. The scalpel produced the skeletonization of the thoracic vertebrae by cutting off the paravertebral and supraspinal muscles. A full laminectomy of T9-10 was made with nippers until the spinal cord was visualized. Using micro-scissors, a solid medulla was cut across the spinal cord and diluted to the sides. With the help of a soft vascular clamp, the area of the spinal cord was crushed, moving deeper into the front surface of the spinal canal. Aspiration of the brain detritus was performed until a 2 mm cavity was formed between the rostral and caudal sections of the spinal cord. In the control group, surgical treatment ended with suturing the wound. In the experimental group, an autograft implanted with a hydrogel containing a neurotrophic factor BDNF and chondrotinase ABC, mesenchymal stem cells was placed in the experimental group, and epineurium was attached to the dura mater more thickly and caudally with polypropylene 10/00. The wound sutured layer-by-layer with Vicryl 4/00, aspetic bandage and removed the inhalation cone.
In the control group, the peripheral nerve segment was pre-sampled. In the position of the rat lying on the stomach, the left lower limb was shaved. The tail of the rat was put under the lower extremity for better visualization of the sciatic nerve. In addition, a 5 cm3 syringe was placed under the lower limb. The orienting lines for access to the sciatic nerve were defined. The sciatic nerve in rats passes on the line connecting the knee joint and the ischial tuberosity. Scalpel made a cut along the line connecting the knee joint and sciatic tubercle. The superficial fascia of the biceps femoris and large gluteus muscles was dissected. Scissors made an incision in the muscles. In the depth of the sciatic nerve was visualized. Further manipulations were carried out under the control of a microscope. The nerve from the surrounding tissue was separated with micro-scissors. Micro pincers have made sure that the nerve is separated from surrounding tissues for 5mm. A sterile wooden spatula was placed under the nerve. Approximately the central point of the prepared area of the nerve was marked, which was located on a wooden spatula, the nerve above and below the central point was cut with a blade so that it eventually turned out to take a segment of the nerve 4 mm in length. The resected portion of the nerve was placed in a 0.9% solution of saline solution. The wound was sewn up layer by layer.
Methods of outcome recording
Spinal cord regeneration was assessed at 1, 15, 30 and 60 days after surgery, by determining the ASIA/Frankel neurologic deficit, and by the Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale in locomotor dysfunction in the open field test (14). The scale is divided from 0 to 9 points, where 0 complete
paralysis of the limbs, 9 points full coordination, position of the limb in relation to the body, stable position of the body and tail. Two months later, the site of the spinal cord was taken in the area of the trauma. Microscopic examination of histological preparations stained with hematoxylin and eosin was carried out with the Axioskop 40, Carl Zeiss, Germany microscope, with a total magnification of X 100, X 200.
Ethical expertise
The experiments were carried out in accordance with the conclusion of the ethical review: Protocol No. 7 of February 12, 2015, 201a
Analysis in subgroups
One of the subgroups of the control group (20 male rats which underwent crushing of the spinal cord without an autograft); (30 male rats with spinal cord crushing followed by autotransplantation of the nerve with neurotrophic factors).
Statistical analysis
Statistical processing of the results of the study was carried out in the STATISTICA software v. 6.0 (StatSoft Inc., USA). The Kraskel-Wallis H criterion, the Newman-Keils q criterion were used. The results are presented in the form M ± c, where M is the sample mean, c is the standard deviation from the mean. Differences were considered statistically significant at p <0.05.
Results
Postoperative testing on ASIA/Frankel scale was performed on days 1, 15, 30 and 60, all animals in the control group showed neurological deficit Type A, with a complete loss of the conductive spinal cord function. Testing on experimental group was performed at the same period, all of the 22 survived rats showed neurological deficit type A at day 30. At day 60, 9 of 16 survived rats were identified with neurological deficit type A and rest 6 rats were identified with neurological deficit type C.
The locomotor test was performed at the same period, during which animal was placed in a plastic circular case with a non-slip floor. Evaluation of the hips movements, the position of the paws, the ability to keep its weight within 4 minutes, and the free movement of the animal was made. Maximum score of 21 was given when full preservation of spinal cord was observed and 0 score for the absence of any movements. All of the rats in both control and experimental groups had pre-operative score of 21, and postoperative score of 0 on day 15. The score of 0 was recorded in the control group in all survived rats on the day 60 of the experiment. In the experimental group, 18 rats at day 30 showed activity levels scored from 3 to 7, on the day 60 activity level scored above 0 was observed in 7 animals.
Parametrization of the motor activity allows quantify generally the degree of recovery of the neurological functions of the spinal cord after injury.
The tracking of motor activity is necessary for a comparative evaluation of the methods of restorative therapy. The control group in our experiments showed by the day 60 the absence of an increase in the "BBB" indicator at the level of score 0, which reflects the process of complete absence of recovery. At the same time in the experimental groups with transplantation average increase was almost twice as much control, which clearly indicates autograft transplantation with hydro-gel.
Comparison of the quality and intensity of post-traumatic reactions in the tissues of the spinal cord between the control and the experiment groups allowed us to reveal the morphological changes caused by the specific effect of the agents contained in the graft, while comparing them with the positive dynamics of recovery of the function.
A fragment of the spinal cord 3-4 cm long (1.5-2 cm in rostral and caudal direction from the epicenter of the lesion), along with vertebrae, was taken for patho-morphological examination. Material was fixed for 24 hours in 10% neutral formalin, followed by traditional method. Hematoxylin and eosin, Van Gieson trichrome stainings were performed, immunohistochemistry was performed using antibodies. Pathomorphological examination was performed using microscope Axioskop 40, Carl Zeiss, Germany, with a total magnification X100, X200.
Table 1
Number of animals withdrawn from the ex_ periment. _
№ Da Contr Experimen
y ol group tal group
1 1 2 3
2 15 3 5
3 30 8 6
4 60 7 16
In all animals, both the experimental and control groups, there was a classic pathomorphological picture of the spinal cord injury (see Figure 1). In the white matter of the spinal cord with the spread on the gray matter, the extensive centers of a coagulative necrosis were observed with formation of microcavities due to lipid hydrolysis accumulations of spherical granules (li-pid-laden macrophages). In the necrotic masses, shadow of the glial cells could be seen. Gray matter had the structure of a "butterfly" with non-uniform plethoric and thrombosed vessels, micronecroses. In the anterior and posterior horns, deformed neurons with shrunken nuclei were determined; its cytoplasm had indistinct contours, basophilic, destroyed in some places - "melting neurons" (see Figure 2.). Swelling and small focal hemorrhages were present.
Fig. 1. Spinal cord injury: Fig. 2. "Melting neurons." necrosis and microcavity X 200. Staining of white with transition to gray matter with hematoxylin and eosin. X100. Staining with hematoxylin and eosin.
In 2 rats of the control group withdrawn from the growths of young fibrous tissue was found by Van Gie-experiment on day 60, in gray substance on border with son trichrome staining. Most likely, these perivascular necrosis zone of white matter, perivascular soft fibrous growths of fibrous tissue are a source of formation of
regenerative scar (see. Fig. 3).
Figure 3. Perivascular growths Fig. 4. Growth ofgranulation tissue of young fibrous tissue in the zone ofperipheral nerve impingement. X100.
Van Gieson trichrome staining. X100. hematoxylin and eosin stainin
In 4 rats of the control group withdrawn from the experiment on days 21 and 30 in the area of peripheral nerve replanting growth of granulation tissue took
glial tissue, immunohystochemically positive for GFAP was observed (Fig. 5). At the junction region of glia and peripheral nerve replanting region proliferates
place (Fig. 4). In one rat of the same group withdrawn of cells immunopositive for BrdU were observed (Fig.
from the experiment on day 60 in the area of peripheral nerve replanting perineural soft fibrous overgrowth of
6).
Fig. 5. Perineural growth of a glia. Fig. 6. Cell proliferation. H. 200. IHC: positive reaction to GFAP. X 200IHC: a positive response to BrdU.
Discussion
Experiments made by A. J. Aguayo in 80s made real changes in the study of spinal cord reconstruction and showed that axons have the capacity for regeneration in case of a favorable cellular environment [1]. Since the axon successfully regenerates in the peripheral nerves, the connection of the cut axon of the central nervous system (CNS) and the peripheral nerve seemed to be able to solve the problem. However, the growth of axons in peripheral nerves is significantly different from their regeneration within the CNS. The difficulty lies in the decelerating role of glial cells and primarily CNS myelin on the growth of the axons [1, 2]. In undamaged CNS axons are in contact with astrocytes and oligodendrocytes. After an injury numerous cellular processes occur, including the division of astrocytes and glial scar formation, destruction of myelin, the division and migration of microglia and oligodendrocyte precursors. Therefore, the center of damage contains four main cell-like types: astrocytes, oligodendrocytes, progenitor oligodendrocytes and microglia. Unfortunately, all of these cells can inhibit axonal growth. Mature oligodendrocytes, which form the CNS myelin, have the two main molecules that inhibits growth: NI-250 (Neutralizing antibodies against neurite growth inhibitor - 250) and MAG (myelin - associated glucopro-tein). The precursors of oligodendrocytes produce proteoglycan NG-2 (neural/glial antigen-2) that pevents axonal regeneration. Action of astrocytes is more mul-tifaceted: the undamaged brain and in a short time after injury, astrocytes may start stimulation of the axon growth, but a few days after the injury, they start to allocate a number of inhibitory proteoglycans. Influence of a microglia is also complex: in general, it promotes axonal regeneration but may allocate various toxins which destroy neurons and damage axons. It is clear that with such a multitude of inhibitory molecules it is difficult to target all molecules. However, M. E. Schwab et al. used antibodies to myelin binded inhibitory molecules: they obtained monoclonal antibodies -IN-1 (inhibitor of neurite growth protein-1) to NI-250. These experiments for the first time convincingly demonstrated the regeneration of axons of the CNS on
a considerable distance [3]. In rats treated with IN-1, a small number of corticospinal axons regenerated at a distance of 1 cm with restoration functions of extremities associated with these neurons. Recently a striking increase in sprouting in the case of use of IN-1 for intact corticospinal tract was found: after cutting by half of the spinal cord and application of IN-1 was made, sprouting of undamaged axons through middle line with the formation of bonds in regions previously occupied by cut axons was observed [4]. New data on the molecular regulation of the brake molecules was obtained by researchers from Duke University and Max Planck Institute for Heart and Lung Research, who screened transcriptome in search for genes whose expression is increased in response to spinal cord injury in zebrafish [5]. It turned out that CTGFa (connective tissue growth factor - a) - a multifunctional cytokine that affects various signaling pathways that regulate adhesion, migration, proliferation and differentiation of cells, the formation and remodeling of blood vessels, bones and connective tissue, including in response to no damage, plays a key role in the formation of cellular bridge and subsequent regeneration of axons. To clarify CTGFa effects, scientists have gained a transgenic zebrafish with blocked gene for that protein. Such fishes developed impairment of glial scar formation, axonal growth and functional recovery after spinal cord injury. In contrast, increased expression of CTGFa stimulated these processes. The same effect was observed when recombinant human CTGF (mammalians unlike zebrafish do not have the isoforms A and B of the protein) administered to the place nervous tissue injury. Increasing CTGFa expression in response to injury of the spinal tissue in zebrafish was observed within three weeks approximately, which correlated with the duration of cell bridge formation [6]. In mammals, in particular rats, damage of the spinal cord causes a longer production of CTGF, which may be associated with the excessive growth of scar tissue that prevents the growth of axons. Application of this methodology on mammalians has the potential for further study [5].
However, the most developed methods are substitution methods, when cells are implanted to the site of the injury that can pass the growing axons. The first experiments were experiments A. J. Aguayo transplantation of segments of peripheral nerves; later they began to use pure cultured Schwann cells of peripheral nerves as the main guide axon growth. In another experiment, M. Bunge used graft of Schwann cells through which axons sprouted, in combination with the shell olfactory cells that migrated entraining axons in the distal segment of the spinal cord [7]. A promising direction in the cell transplantation is a transplantation olfactory bulb cell that have the ability to stimulate natural regrowth of diseased peripheral and central axons. Transplantation of these cells in rats with complete transversal defeat of thoracic region of spinal cord inducde axonal regeneration over long distances and subsequent recovery of paralyzed limbs locomotion [7, 8, 9]. P. Tabakow, Ph. D and W. Jarmundowicz have combined the technology of transplantation of olfactory bulb cells in humans with improved neurological deficit [10].
Another successful use of transplantation technology was transplantation of fetal tissue, and cultured neuroblasts [11]. In 1982, Bjorklund has convincingly proved the use of embryonic neural tissue as a "bridge" to the central axon regeneration through the brain tissue defect. Since this moment transplantation strategy occupies the most important place in solving the problem of spinal cord regeneration. Transplanted embryoblast characterized by a high growth potential and in some cases lead to the restoration of lost functions [12].
The extent of axon germination is determined by the correlation between the influence of the cellular environment and their regenerative capacity. Since under normal conditions the injured nervous tissue has an extremely inhibitory effect on axon growth, and the axons itself have a low regenerative potential, the maximum efficiency of their recovery should be expected when influencing both factors: changes in the cellular environment and stimulation of axons for regeneration [13]. Trophic factors have been used in most of the transplantation experiments described above. When used, the number of regenerating axons increased. The first demonstration were experiments conducted by M. E. Schwab, who used in conjunction with antibodies to myelin (IN-1) trophic factors (NT3 - neurotrophic growth factor-3, and BDNF -brain-derived neurotrophic factor) [14]. In experiments with Schwann cells, infusion of trophic factors increased the number of axonal sprouting in Schwann cells.
Similar results were obtained with transplantation of peripheral nerves and embryonic tissue. Isolated infusion of neurotrophic factor is not sufficient to achieve recovery. As an alternative to the presentation of trophic factors, genetically modified fibroblasts secreting NT3 were used. When placing the cells in the region of the dorsal hemisection of the spinal cord corticospinal axons were attracted to the transplant in a large number, and some have evolved through the graft in the distal part of the spinal cord, with some recovery of sensorimotor functions.
In our study, both in the experimental and control groups, there was a classic pathomorphological picture
of spinal cord injury. The process was localized more in the white matter, with autodestruction of gray matter. In the control group withdrawn from the experiment on day 60 in the gray matter in the zone of peripheral nerve replanting on border with white matter necrosis zones soft perivascular fibrous growths of young fibrous tissue were observed using histochemical Van Gieson tri-chrome staining. sMost likely, these perivascular proliferations of fibrous tissue are a source of regenerative scar. At the junction of the peripheral glia and replanted peripheral nerve, proliferates of nerve cells that are immunopositive for BrdU were observed, which characterizes morphogenesis of the initial stage of regeneration of spinal cord injuries. The obtained results determine the need for further observations of morphogenesis recovery of damaged spinal cord by transplantation of peripheral nerve with the introduction of the regeneration hydrogel.
Conclusion
The use of autograft nerve containing a biodegradable hydrogel with neurotrophic factors, mesen-chymal cells, which is capable of releasing anti-inhibitor molecules such as thermostabilized Chondroitinase ABC (ChABC) into the damaged section of the spinal cord positively affect the regeneration of damaged nerve tissue, which improves recovery prognosis of spinal cord's conductive function. The results of the study indicate the perspective of this method in the surgical treatment of severe spinal cord injury.
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THE SPINAL ANESTHESIA AND COMBINED SPINAL EPIDURAL ANESTHESIA VERSUS GENERAL ANESTHESIA FOR CESAREAN SECTION IN SEVERE PREECLAMPSIA: A RANDOMIZED CONTROLLED TRIAL STUDY
Nguyen Duc Lam
Hanoi Medical University
Vu Van Du
National Hospital of Obstetric and Gynecology
ABSTRACT
This study aim to evaluate the analgesia efficacy and the maternal/fetal effects of three anesthetic methods used randomly in women with severe preeclampsia who required cesarean delivery: spinal anesthesia (SA), combined spinal epidural (CSE) anesthesia versus general anesthesia (GA). Material and methods: A RCT study on 180 parturients with severe preeclampsia, who were to be delivered by cesarean and were randomized to general, epidural, or combined spinal-epidural anesthesia. Results: Spinal anesthesia, CSE have good per-operative anesthesia, good postoperative analgesia (good 95% in spinal anesthesia, 100% in CSE; VAS < 4); good hemodynamic stability (hypotension 21,67% in spinal anesthesia; 11,67% in CSE) with minor side effects, no depression of the newborn (Apgar 1' score is 8,4 ± 0,7 in spinal anesthesia, 8,5 ± 0,8 in CSE and 6,7 ± 1,9 in GA). Conclusion: Spinal anesthesia or CSE is a safe choice for caesarean delivery when compared to general anesthesia in severe preeclampsia. Spinal anesthesia is safe and provides better maternal outcome and has fewer intra operative and postoperative complications: good per-operativeanesthesia, good postoperative analgesia, stable hemodynamics, minor side effects and no depression of the newborn.
Keywords: preeclampsia, cesarean section, spinal anesthesia, general anesthesia, combined spinal epidural anesthesia.
1. Introduction
Pre-eclampsia is a complex syndrome of human pregnancy, characterized by hypertension after 20 weeks gestation and proteinuria. Pre-eclampsia is classified as severe if blood pressure (BP) is >160 mmHg systolic and/or >110 mmHg diastolic; or any one of following is present: cerebral or visual disturbances, proteinuria is > 3.5 g/l, thrombocytopenia, impaired liver function, impaired kidney function. Preeclampsia appear the third trimester term of pregnancy and can lead to serious complications for maternal, fetal, or neonatal health. Studies have shown that adequate therapy for a preterm severe preeclampsia is a delivery by cesarean during expectant management [1], [2], [3]. Anesthesia for a safe cesarean delivery is still an on-going challenge for obstetrical anesthesiologist. In the others days, spinal anesthesia were not recommended for se-
vere preeclampsia women due to a possible post-operative hypotension complication which decreases utero-placental blood flow.
Recent studies shown evidence supporting spinal anesthesia for severe preeclampsia women, with no significant differences between preeclampsia women underwent either SA or Epidural anesthesia. Combined spinal epidural (CSE) is well established with better maternal outcomes because it can associate the advantages of these two methods without increasing their side effects. CSE is therefore now used in several countries including Vietnam. In the other hand, GA is still a frequent anesthetic method for preeclampsia women in Vietnam. Therefore, we conduct this research to compare the analgesia efficacy as well as the maternal/neonatal outcomes of three anesthetic method for cesarean delivery on severe preeclampsia women: SA, CSE and GA.
