Efficacy of low extra-abdominal aortic block in cesarean section for placenta accreta spectrum disorders and its effect on the expression of MDA and SOD. / ä½Žä½è ¹ä¸»åŠ¨è„‰å¤–é˜»æ–­æœ¯åœ¨èƒŽç›˜æ¤å ¥æ€§ç–¾ç— å‰–å®«äº§æœ¯ä¸­çš„æ•ˆæžœåŠå¯¹MDA、SOD表达的影响.

OBJECTIVES: Placenta accreta spectrum disorders (PAS) refers to a group of abnormalities in placental adhesion and invasion, which may lead to serious complications such as intractable postpartum hemorrhage. The use of low-level extra-abdominal aortic temporary block during cesarean section may reduce intraoperative bleeding in patients with PAS, but it may also cause ischemia-reperfusion injury. In this study, we intend to investigate the efficacy of low extra-abdominal aortic block in cesarean section for placental implantation disease and its effect on malondialdehyde (MDA) level and superoxide dismutase (SOD) activity, and analyze the severity of ischemia-reperfusion injury caused by them. METHODS: Pregnant women with invasive placenta accreta spectrum disorders who delivered in the Department of Obstetrics and Gynecology of the Third Xiangya Hospital of Central South University from July 2017 to July 2021, were selected, and they were divided into 2 groups. Group A consisted of those who underwent low extra-abdominal aortic block during cesarean section (n=15) and group B consisted of those who did not undergo extra-abdominal aortic block (n=15). The intraoperative bleeding, blood transfusion, hysterectomy and complication rate, postoperative hospital stay and hospitalization expenses were compared between the 2 groups to analyze the efficacy of abdominal aortic block. The biochemical indexes related to ischemia-reperfusion, MDA content and total superoxide dismutase (T-SOD) activity, were measured at the corresponding time points in both groups. The time points of each test were: in group A, before the block of the low extra-abdominal aorta after delivery (A0), 0 h (A1, when the myometrium was started to be sutured), 0.5 h (A2), 2 h (A3), and 4 h (A4) after the open block; in group B, after delivery of the fetus (B0), 0 h (B1), 0.5 h (B2), 2 h (B3), and 4 h (B4) after the myometrium was started to be sutured. Total duration of abdominal aortic block in group A was also recorded. Both groups were observed for sings of edema, ischemia, necrosis and infection in the limbs after surgery. The severity of ischemia-reperfusion injury caused by abdominal aortic block were determined by detecting the relevant biochemical indexes at different moments of reperfusion. RESULTS: The intraoperative bleeding and blood transfusion in group A were less than those in group B, and the difference was statistically significant (P<0.05). There was no significant difference in postoperative hospital stay and hospitalization expenses between the 2 groups (P>0.05). Surgical complications: in group A, the uterus was preserved in all cases, there was 1 bladder injury and 2 pelvic infections; while in group B, there was 1 hysterectomy, 3 bladder injuries, and 3 pelvic infections. Changes in T-SOD and MDA values: compared with A0 before block, the MDA level was significantly elevated in blood at time points A1, A2, and A3, while SOD activity was significantly decreased (P<0.05), and the 2 observed indexes basically returned to A1 level (ischemic period) at 4 h after open block (A4). There was no significant difference in the changes of T-SOD and MDA in group B (P>0.05). Comparison of T-SOD and MDA levels between group A and B: the difference of the 2 indexes was not statistically significant between A0 and B0 (P>0.05), MDA level was not statistically significant between A1 and B1, T-SOD activity at A1 was lower than B1, the difference was statistically significant, at the rest of the same time point, MDA level in group A were higher than that in group B, T-SOD activity in group A were lower than that in group B, the difference was statistically significant (P<0.05). No postoperative limb edema, ischemia, necrosis, or infection occurred in both groups. CONCLUSIONS: Low-level extra-abdominal aortic block effectively reduces bleeding and transfusion during cesarean section for placenta accreta spectrum disorders, resulting in a transient MDA elevation and a decrease of SOD activity, which means causing transient ischemia-reperfusion injury without complications such as limb edema, ischemia, necrosis, and infection.

Efficacy of temporary ligation of infrarenal abdominal aorta during cesarean section in pernicious placenta previa.

OBJECTIVE: To evaluate the efficacy and safety of temporary loop ligation of the infrarenal abdominal aorta for control of intraoperative blood loss in patients with pernicious placenta previa.
 Methods: We retrospectively analyzed the clinical data of 14 patients with pernicious placenta previa, who underwent temporary loop ligation of the infrarenal abdominal aorta for control of blood loss during cesarean section between July 2013 and December 2014.
 Results: Eight patients received conservative management to preserve the uterus and 6 patients underwent cesarean hysterectomy. The occlusion time of the abdominal aorta was (31.42±12.67) min. The average estimated intraoperative blood loss was (1 117.85±745.13) mL. The volume of packed red blood cell transfusion was (3.91±3.24) units, and the volume of fresh frozen plasma transfusion was (192.85±156.71) mL. Post-operative histologic diagnosis revealed 6 cases of placenta percreta, 4 of increta, 3 of accreta and 1 non-creta. All patients experienced an uneventful postoperative recovery.
 Conclusion: In patients with pernicious placenta previa, temporary ligation of the infrarenal abdominal aorta provide a safe and effective means for controlling intraoperative hemorrhage during cesarean section. Additionally, the procedure may provide an opportunity to preserve fertility by avoiding a cesarean hysterectomy.

[Therapeutic effect of hemin on gestational hypertension in rats and the mechanism].

OBJECTIVE: To investigate the therapeutic effects of hemin, an inducer of heme oxygenase, in a rat model of gestational hypertension and explore the possible mechanism. METHODS: Eighteen pregnant SD rats at day 12 of gestation were randomized equally into gestational hypertension model group, hemin treatment group, and normal pregnancy (control) group. In the former two groups, the rats were subjected to daily nitro-L-arginine methyl ester (L-NAME, 80 mg/kg) gavage since gestational day 14 for 7 consecutive days to induce gestational hypertension; saline was administered in the same manner in the control rats. The rats in hemin group received daily intraperitoneal injection of hemin (30 mg/kg) starting from gestational day 16. HO activity and carboxyhemoglobin (COHb) level in rat placental tissue were detected with spectrophotometric method, and soluble vascular endothelial growth factor receptor-1 (sFlt-1) and vascular endothelial growth factor (VEGF) level in the placental tissue homogenate supernatant were detected using ELSIA. RESULTS: At gestational day 20, the blood pressure and 24-h urinary protein were significantly higher in the model group than in the other two groups (P<0.05), and were higher in hemin group than in the control group (P<0.05); HO activity and COHb content in the placenta tissue were the lowest in the model group (P<0.05), and was lower in hemin group than in the control group (P<0.05). The level of sFlt-1 was significantly higher and VEGF level significantly lower in the model group than in the other two groups (P<0.05); sFlt-1 level remained higher and VEGF lower in hemin group than in the control group (P<0.05). CONCLUSION: Hemin can reduce blood pressure and urinary protein in rats with gestational hypertension possibly by up-regulating HO activity, enhancing carbon monoxide production, reducing sFlt-1 and increasing VEGF in the placental tissue.