The effect of sevoflurane on retinal angiogenesis in a mouse model of oxygen-induced retinopathy

Sevoflurane Postconditioning Protects From an Early Neurological Deficit After Subarachnoid Hemorrhage: Results of a Randomized Laboratory Study in Rats

BACKGROUND

Subarachnoid hemorrhage (SAH) is associated with neurocognitive impairment. Recent data suggest that sevoflurane attenuates edema formation after SAH in rats. However, so far, no information is available about the long-term repair phase, nor if sevoflurane impacts functionality by increasing vascularity. This study tested whether sevoflurane postconditioning would improve long-term neurologic deficit through increased formation of new vessels close to the hemorrhage area.

METHODS

Fifty-three animals were subjected to SAH or sham surgery with or without a 2-hour sevoflurane postconditioning (versus propofol anesthesia). Animal survival, including dropout animals due to death or reaching termination criteria, as well as neurologic deficit, defined by the Garcia score, were assessed 2 hours after recovery until postoperative day 14. On day 14, blood samples and brain tissue were harvested. Vessel density was determined by the number of cluster of differentiation 31 (CD31)-positive vessels, and activated glial cells by glial fibrillary acidic protein (GFAP)-positive astrocytes per field of view.

RESULTS

The survival rate for sham animals was 100%, 69% in the SAH-propofol and 92% in the SAH-sevoflurane groups. According to the log-rank Mantel-Cox test, survival curves were significantly different (P = .024). The short-term neurologic deficit was higher in SAH-propofol versus SAH-sevoflurane animals 2 hours after recovery and on postoperative day 1 (propofol versus sevoflurane: 14. 6 ± 3.4 vs 15. 9 ± 2.7 points, P = .034, and 16. 2 ± 3.5 vs 17. 8 ± 0.9 points, P = .015). Overall complete recovery from neurologic deficit was observed on day 7 in both SAH groups (18. 0 ± 0.0 vs 18. 0 ± 0.0 points, P = 1.000). Cortical vascular density increased to 80. 6 ± 15.0 vessels per field of view in SAH-propofol animals (vs 71. 4 ± 10.1 in SAH-sevoflurane, P < .001). Activation of glial cells, an indicator of neuroinflammation, was assessed by GFAP-positive astrocytes GFAP per field of view. Hippocampal GFAP-positive cells were 201 ± 68 vs 179 ± 84 cells per field of view in SAH-propofol versus SAH-sevoflurane animals (P < .001).

CONCLUSIONS

Sevoflurane postconditioning improves survival by 23% (SAH-sevoflurane versus SAH-propofol). The sevoflurane intervention could attenuate the early neurologic deficit, while the long-term outcome was similar across the groups. A higher vascular density close to the SAH area in the propofol group was not associated with improved outcomes.

Microvascular Changes of the Non-surgical Eye after General Anesthesia in Optical Coherence Tomography Angiography

Purpose: To investigate chorioretinal vascular changes in the non-surgical eyes of patients who underwent vitreoretinal surgery under general anesthesia using optical coherence tomography angiography (OCTA).Methods: Data from 40 patients who underwent retinal surgery were retrospectively analyzed. Ophthalmologic examinations (including OCTA) were performed in the morning before and after surgery. The presence of intraoperative hypotension (IOH; mean arterial pressure <70 mmHg) was determined based on medical records. The vessel density of superficial and deep retinal capillary plexus layers, choriocapillaris void features, and thickness of the choroid and retina were quantified after image processing. Associations between retinal OCTA parameters and anesthesia profiles were also assessed.Results: DCP vessel density was increased after general anesthesia (p < 0.05). Among the patients who experienced IOH, there was no statistical difference in chorioretinal vessel parameters before and after general anesthesia. Also, we did not observe a difference in chorioretinal vessel parameters after general anesthesia between healthy patients and patients with chronic disease, including hypertension and diabetes (p > 0.05). The duration of anesthesia and average size of the choriocapillaris void (p < 0.05, r = -0.32), and the intraoperative mean arterial pressure (MAP) fluctuation and DCP, showed statistically significant negative linear correlations (p < 0.05, r = -0.38). The choriocapillaris void size and intraoperative MAP fluctuation also displayed a significant negative correlation (p < 0.05, r = -0.37), while the average size signal void showed a weak positive linear correlation (p < 0.01, r = 0.41; and p < 0.01, r = 0.44, respectively).Conclusions: This is the first study to assess the effects of general anesthesia on chorioretinal vessels using OCTA. The Vessel density of the DCP was significantly increased in the non-surgical eye after total vitrectomy under general anesthesia. Furthermore, we found a correlation between MAP fluctuation and choriocapillaris void features. More studies are needed to confirm and expand on these observations.

Sevoflurane inhibits growth factor-induced angiogenesis through suppressing Rac1/paxillin/FAK and Ras/Akt/mTOR

Aim: We investigated the direct effects of sevoflurane on angiogenesis and a variety of tumor cells. Materials & methods: The antiangiogenic activity of sevoflurane was determined using angiogenesis and biochemical assays. Results: Sevoflurane at low doses inhibits capillary network formation. Sevoflurane inhibited VEGF- and bFGF-stimulated migration, adhesion and growth in endothelial cells and induced apoptosis. Sevoflurane only at high doses inhibited growth and migration of tumor cells, suggesting differential effects of sevoflurane between endothelial and tumor cells. Mechanistically, sevoflurane decreased growth factors-induced Ras and Rac1 activation, and suppressed Ras and Rac1 signaling. Conclusion: We demonstrate the antiangiogenic effects of sevoflurane and provide preclinical evidence into the potential mechanisms by which sevoflurane may negatively affect cancer growth and metastasis.

The effect of desflurane on retinal angiogenesis in a mouse model of oxygen-induced retinopathy

PURPOSE

Retinopathy of prematurity (ROP) is an ocular disorder that primarily occurs in premature infants and is the most common cause of vision impairment. This study examined the effect of desflurane on angiogenesis in a mouse model of oxygen-induced retinopathy (OIR).

METHODS

Mice were randomly allocated to the control (C), ROP control (R_c), or ROP with desflurane exposure (R_d) group. To induce ROP, 7-day-old mice were exposed to 75% oxygen in a chamber for 5 days [postnatal days (P) 7-12], and thereafter returned to room air. Age-matched mice exposed to room air formed the C group. The R_d group was exposed to 8% desflurane for 2 h on P12, P13, and P14 with 40% oxygen. To observe changes in angiogenesis of the retina, mice were sacrificed at P16.

RESULTS

The ratio of avascular area/total retinal area was not changed significantly in the R_d group, compared to the R_c group. The expression of endothelial growth factor A (VEGF-A) and hypoxia inducible factor-1α (HIF-1α) in the R_d group and R_c group was not significantly different.

CONCLUSIONS

Desflurane does not have a significant influence on retinal angiogenesis via HIF-1α and VEGF-A expression in the OIR mouse model. However, these findings are not directly applicable to premature infants, and it is thus necessary to perform further studies to determine the effect of desflurane on angiogenesis.

Impact of Anesthetics, Analgesics, and Perioperative Blood Transfusion in Pediatric Cancer Patients: A Comprehensive Review of the Literature

Cancer is the leading cause of death by disease in developed countries. Children and adolescents with cancer need surgical interventions (ie, biopsy or major surgery) to diagnose, treat, or palliate their malignancies. Surgery is a period of high vulnerability because it stimulates the release of inflammatory mediators, catecholamines, and angiogenesis activators, which coincides with a period of immunosuppression. Thus, during and after surgery, dormant tumors or micrometastasis (ie, minimal residual disease) can grow and become clinically relevant metastasis. Anesthetics (ie, volatile agents, dexmedetomidine, and ketamine) and analgesics (ie, opioids) may also contribute to the growth of minimal residual disease or disease progression. For instance, volatile anesthetics have been implicated in immunosuppression and direct stimulation of cancer cell survival and proliferation. Contrarily, propofol has shown in vitro anticancer effects. In addition, perioperative blood transfusions are not uncommon in children undergoing cancer surgery. In adults, an association between perioperative blood transfusions and cancer progression has been described for some malignancies. Transfusion-related immunomodulation is one of the mechanisms by which blood transfusions can promote cancer progression. Other mechanisms include inflammation and the infusion of growth factors. In the present review, we discuss different aspects of tumorigenesis, metastasis, angiogenesis, the immune system, and the current studies about the impact of anesthetics, analgesics, and perioperative blood transfusions on pediatric cancer progression.