Evolving Navigation, Robotics, and Augmented Reality in Minimally Invasive Spine Surgery.

Innovative technology and techniques have revolutionized minimally invasive spine surgery (MIS) within the past decade. The introduction of navigation and image-guided surgery has greatly affected spinal surgery and will continue to make surgery safer and more efficient. Eventually, it is conceivable that fluoroscopy will be completely replaced with image guidance. These advancements, among others such as robotics and virtual and augmented reality technology, will continue to drive the value of 3-dimensional navigation in MIS. In this review, we cover pertinent features of navigation in MIS and explore their evolution over time. Moreover, we aim to discuss the key features germane to surgical advancement, including technique and technology development, accuracy, overall health care costs, operating room time efficiency, and radiation exposure.

Remote Cerebellar Hemorrhage Presenting with Cerebellar Mutism after Spinal Surgery: An Unusual Case Report.

Dural injury during spinal surgery can subsequently give rise to a remote cerebellar hemorrhage (RCH). Although the incidence of such injury is low, the resulting hemorrhage can be life threatening. The mechanism underlying the formation of the hemorrhage is not known, but it is mostly thought to develop after venous infarction. Cerebellar mutism (CM) is a frequent complication of posterior fossa operations in children, but it is rarely seen in adults. The development of CM after an RCH has not been described. We describe the case of a 65-year old female who lost cerebrospinal fluid after inadvertent opening of the dura during surgery. Computerized tomography performed when the patient became unable to speak revealed a bilateral cerebellar hemorrhage.

The Axon Protective Effects of Syringic Acid on Ischemia/Reperfusion Injury in a Rat Sciatic Nerve Model.

AIM: In the relevant literature, there is no experimental study that investigated the axon protective effects of syringic acid- a polyphenol compound- with an anti-oxidant capacity on ischemia/reperfusion injury. MATERIAL AND METHODS: The rats were randomly divided into four groups: Control group (no medication or surgical procedure), Sham group, Syringic acid group, and Methyprednisolone (MP) Group. Ischemia was achieved by abdominal aorta clamping and all animals were sacrificed 24 hours after ischemia. Harvested sciatic nerve segments were investigated histopathologically and for tissue biochemistry. RESULTS: Ischemic fiber degeneration scores were found significantly lower in syringic acid and MP groups than sham group. Additionally, apoptosis-related cysteine peptidase caspase-3 immunostaining scores were lower in syringic acid and MP groups. Biochemically, superoxide dismutase and nuclear respiratory factor 1 values were significantly higher in syringic acid group compared to those of control and sham groups while malondialdehyde levels were significantly lower in the syringic acid group. CONCLUSION: Syringic acid reduces oxidative stress and axonal degeneration in rat sciatic nerve after ischemia/reperfusion injury. Therefore, syringic acid may play a role in the treatment of peripheral nerve injuries due to ischemia/reperfusion.

Comparison of Anterior Cervical Discectomy Fusion Techniques: Bladed and Non Bladed PEEK Cages.

AIM: The aim of this study is to compare the different types of fusion materials known as PEEK cages used during anterior cervical discectomy (ACD) surgery. MATERIAL AND METHODS: A total of 67 patients were operated and evaluated retrospectively under two groups (group A: 35 PEEK cage patients, group B: 32 bladed PEEK cage patients) between 2009 and 2013. Preoperative and postoperative (postoperative first day, postoperative 1st, 3rd and 12-24th mo) images were obtained. The cervical disc heights, cervical and segmental lordotic angles of the operated levels were calculated. Pain assessment was performed and fusion rates were also compared. Mann-Whitney U test was applied to compare the outcomes. RESULTS: The pain scores (especially for arm pain) were decreased significantly in both groups after surgery regardless of the type of operation technique (P < 0.05). There were no significant differences between both groups at the disc height measurements of operated levels in postoperative periods (P > 0.05). In addition to these; there was no significant difference between both groups of segmental and cervical lordodic angles in postoperative periods (P > 0.05). There was no statistically significant difference between the fusion rates and pain scores of both groups (P > 0.05). CONCLUSION: The PEEK cage and bladed PEEK cages can be used safely to obtain fusion after ACD.

Effects of Aloe Vera on Spinal Cord Ischemia-Reperfusion Injury of Rats.

AIM: The purpose of this study was to evaluate the possible protective/therapeutic effects of aloe vera (AV) on ischemia-reperfusion injury (I/R) of spinal cord in rats. MATERIALS AND METHODS: A total of 28 Wistar Albino rats were divided into four random groups of equal number (n = 7). Group I (control) had no medication or surgery; Group II underwent spinal cord ischemia and was given no medication; Group III was administered AV by gastric gavage for 30 days as pre-treatment; Group IV was administered single dose intraperitoneal methylprednisolone (MP) after the ischemia. Nuclear respiratory factor-1 (NRF1), malondialdehyde (MDA) and superoxide dismutase (SOD) levels were evaluated. Tissue samples were examined histopathologically and neuronal nitric oxide synthase (nNOS) and nuclear factor-kappa B (NF-κB) protein expressions were assessed by immunohistochemical staining. RESULTS: NRF1 and SOD levels of ischemia group were found to be lower compared to the other groups. MDA levels significantly increased after I/R. Treatment with AV and MP resulted in reduced MDA levels and also alleviated hemorrhage, edema, inflammatory cell migration and neurons were partially protected from ischemic injury. When AV treatment was compared with MP, there was no statistical difference between them in terms of reduction of neuronal damage. I/R injury increased NF-κB and nNOS expressions. AV and MP treatments decreased NF-κB and nNOS expressions. CONCLUSIONS: It was observed that aloe vera attenuated neuronal damage histopathologically and biochemically as pretreatment. Further studies may provide more evidence to determine the additional role of aloe vera in spinal cord ischemia reperfusion injury.

The effect of aloe vera on ischemia--Reperfusion injury of sciatic nerve in rats.

PURPOSE: Aloe vera is compound which has strong antioxidant and anti-inflammatory effects. We investigated the neuroprotective role of aloe vera treatment in rats with experimental sciatic nerve ischemia/reperfusion injury. METHODS: Twenty-eight male Wistar Albino rats were divided equally into 4 groups. Groups; Control group (no surgical procedure or medication), sciatic nerve ischemia/reperfusion group, sciatic nerve ischemia/reperfusion+aloe vera group and sciatic nerve ischemia/reperfusion+methylprednisolone group. Ischemia was performed by clamping the infrarenal abdominal aorta. 24 hours after ischemia, all animals were sacrificed. Sciatic nerve tissues were also examined histopathologically and biochemically. RESULTS: Ischemic fiber degeneration significantly decreased in the pre-treated with aloe vera and treated with methylprednisolone groups, especially in the pre-treated with aloe vera group, compared to the sciatic nerve ischemia/reperfusion group (p<0.05). A significant decrease in MDA, an increase in NRF1 level and SOD activity were observed in the groups which obtained from the AV and MP groups when compared to the sciatic nerve ischemia/reperfusion group. When all results were analysed it was seen that the aloe vera group was not statistically different compared to the MP group (p>0.05). CONCLUSIONS: Aloe vera is effective neuroprotective against sciatic nerve ischemia/reperfusion injury via antioxidant and anti-inflammatory properties. Also aloe vera was found to be as effective as MP.

Effect of Using High-Speed Drill in Anterior Cervical Discectomy and Fusion.

AIM: The objective of this study was to investigate the effect of using 2 different surgical techniques (curette or high-speed drill) in anterior cervical discectomy surgery on the healing of cases. MATERIAL AND METHODS: Fifty-four operated cervical disc hernia cases were retrospectively examined in 2 groups. Discectomy and osteophytectomy were carried out in Group A by using a high-speed drill, while a curette was used for group B. Preoperative and postoperative computerized tomography and direct radiography were performed. Cervical disc height, cervical and segmental lordotic angles were calculated. The visual analogue scale and Odom's criteria were used in the assessment of pain and clinical healing. The fusion ratio of both groups was compared. The Mann-Whitney U test was used to compare data from the groups. RESULTS: Satisfactory results were obtained in the groups where high-speed drill and curette were used. Independently from the surgical technique, pain scores were significantly reduced in both groups after surgery. No radiologically significant differences were identified between the two groups within the postoperative period. CONCLUSION: Either high-speed drill or curette can be chosen for the osteophytectomy and discectomy stages of anterior cervical discectomy operations.

Does Glp-2 have a protective effect on cerebral ischemia/reperfusion model?

BACKGROUND/AIM: To investigate the neuroprotective effects of glucagon-like peptide 2 (Glp-2), which increases cerebral blood flow, on the hippocampal complex after cerebral ischemia/reperfusion (I/R) injury in rats. MATERIALS AND METHODS: Animals were randomized into 4 groups: sham, I/R + 0.9% NaCl, I/R + pre-Glp-2, and I/R + post-Glp-2. Cerebral ischemia was performed via the occlusion of the bilateral internal carotid artery for 40 min and continued with a reperfusion process. At the end of 6 h of reperfusion, animals were decapitated in all groups and brain tissues were removed. Malondialdehyde (MDA) and natural intracellular antioxidant glutathione (GSH) levels and myeloperoxidase (MPO) activities were measured in the left hippocampal tissue. The right hippocampal tissues of all group members were taken for histopathologic study. RESULTS: MDA levels and MPO activities increased from Group I to Group II and decreased from Group II to Groups III and IV. On the other hand, GSH levels were not significantly different among the groups. The number of apoptotic hippocampal tissue cells increased from Group I to Group II and decreased from Group II to Groups III and IV. CONCLUSION: Our preliminary study revealed that Glp-2 treatment may decrease oxidative damage from I/R in cerebral tissue.

Spontaneous Regression of Lumbar Disc Herniation After Weight Loss: Case Report.

Diagnosis, treatment, and surgery for lumbar disc herniations have existed for over a century. However, during the last three decades, there have been many new developments in imaging techniques, surgical procedures, physical medicine, and rehabilitation. In light of this, the most effective and appropriate treatment is controversial. Spontaneous regression of sequestrated, extruded, or protruded disc herniation has often been reported in the literature, although it is still a rare phenomenon. After a thorough review of the literature, we did not find any case report about this phenomenon after weight loss. In this report, though, we present a recent case about spontaneous regression of extruded disc herniation following weight loss.

The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats.

OBJECTIVE: The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. METHODS: Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. RESULTS: The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (p<0.05). Catalase and superoxide dismutase levels of the kefir group were significantly higher than ischemia group (p<0.05). In histopathological samples, the kefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (p<0.05). In immunohistochemical staining, hipoxia-inducible factor-1α and caspase 3 immunopositive neurons were significantly decreased in kefir group compared with ischemia group (p<0.05). The neurological deficit scores of kefir group were significantly higher than ischemia group at 24 h (p<0.05). CONCLUSION: Our study revealed that kefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future.

The Effect of Coumaric Acid on Ischemia-Reperfusion Injury of Sciatic Nerve in Rats.

The aim of the study was to determine the effect of coumaric acid on sciatic nerve ischemia/reperfusion (SNI) injury in rats. The rats were randomly divided into four groups: control group (no medication or surgical procedure), SNI group, SNI + coumaric acid (CA) group, and SNI + methylprednisolone (MP) group. Ischemia was achieved by abdominal aorta clamping, and all animals were sacrificed 24 h after ischemia. Harvested sciatic nerve segments were investigated histopathologically and for tissue biochemistry. A significant decrease in MDA, an increase in NRF1 levels, and increase in SOD activity were observed in the groups which received coumaric acid and methylprednisolone when compared to the corresponding untreated group (p < 0.05). Ischemic fiber degeneration significantly reduced in the SNI + CA and SNI + MP groups, especially in the SNI + MP group, compared to the SNI group (p < 0.05). Beta amyloid protein expressions were significantly decreased in the SNI + CA group compared to the SNI group (p < 0.05). Our study revealed that coumaric acid treatment after ischemia/reperfusion in rat sciatic nerves reduced oxidative stress and axonal degeneration. Therefore, coumaric acid may play a role in the treatment of peripheral nerve injuries due to ischemia/reperfusion.

Neuroprotective effect of p-coumaric acid in rat model of embolic cerebral ischemia.

OBJECTIVES: Stroke poses a crucial risk for mortality and morbidity. Our study aimed to investigate the effect of p-coumaric acid on focal cerebral ischemia in rats. MATERIAL AND METHODS: Rats were randomly divided into four groups, namely Group I (control rats), Group II (ischemia rats), Group III (6 hr ischemia + p-coumaric acid rats) and Group IV (24 hr ischemia + p-coumaric acid rats). Cerebral ischemia was induced via intraluminal monofilament occlusion model. In all groups, the brain was removed after the procedure and rats were sacrificed. Malondialdehyde, superoxide dismutase and nuclear respiratory factor-1 were measured in the ischemic hemisphere. The histopathological changes were observed in the right hemisphere within the samples. Functional assessment was performed for neurological deficit scores. RESULTS: Following the treatment, biochemical factors changed significantly. Histopathologically, it was shown that p-coumaric acid decreased the oxidative damage. The neurological deficit scores of p-coumaric acid-treated rats were significantly improved after cerebral ischemia. CONCLUSION: Our results showed that p-coumaric acid is a neuroprotective agent on account of its strong anti-oxidant and anti-apoptotic features. Moreover, p-coumaric acid decreased the focal ischemia. Extra effort should be made to introduce p-coumaric acid as a promising therapeutic agent to be utilized for treatment of human cerebral ischemia in the future.

Management of Type II Odontoid Fracture for Osteoporotic Bone Structure: Preliminary Report.

AIM: Anterior transodontoid screw fixation technique is generally chosen for the management of type II odontoid fractures. The nonunion of type II odontoid fractures is still a major problem especially in elderly and osteoporotic patients. Eleven osteoporotic type II odontoid fracured patients were presented in this article. MATERIAL AND METHODS: We have divided 11 patients in two groups as classical and Ozer's technique. We have also compared (radiologically and clinically) the classical anterior transodontoid screw fixation (group II: 6 cases) and Ozer's transodontoid screw fixation technique (group I: 5 cases) retrospectively. RESULTS: There was no difference regaring the clinical features of the groups. However, the radiological results showed 100% fusion for Ozer's screw fixation technique and 83% fusion for the classical screw fixation technique. CONCLUSION: In conclusion, we suggest that Ozer's technique may help to increase the fusion capacity for osteoporotic type II odontoid fractures.

The Neuroprotective Effect of Coumaric Acid on Spinal Cord Ischemia/Reperfusion Injury in Rats.

The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of coumaric acid on spinal cord ischemia injury in rats. Rats were divided randomly into four groups of eight animals as follows: control, ischemia, ischemia + coumaric acid, and ischemia + methylprednisolone. In the control group, only a laparotomy was performed. In all other groups, the spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. Levels of malondialdehyde and nuclear respiratory factor 1 were analyzed, as were the activity of superoxide dismutase. Histopathological and immunohistochemical evaluations were performed. Neurological evaluation was performed with the Tarlov scoring system. The ischemia + coumaric acid group was compared with the ischemia group, and a significant decrease in malondialdehyde and levels was observed. Nuclear respiratory factor 1 level and superoxide dismutase activity of the ischemia + coumaric acid group were significantly higher than in the ischemia group. In histopathological samples, the ischemia + coumaric acid group is compared with the ischemia group, and there was a significant increase in numbers of normal neurons. In immunohistochemical staining, hypoxia-inducible factor-1α and NF-kappa B immunopositive neurons were significantly decreased in the ischemia + coumaric acid group compared with that in the ischemia group. The neurological deficit scores of the ischemia + coumaric acid group were significantly higher than the ischemia group at 24 h. Our results revealed for the first time that coumaric acid exhibits meaningful neuroprotective activity following ischemia-reperfusion injury of the spinal cord.

The Neuroprotective Effect of Syringic Acid on Spinal Cord Ischemia/Reperfusion Injury in Rats.

Acute arterial occlusions via different vascular pathologies are the main causes of spinal cord ischemia. We investigated neuroprotective effects of syringic acid on spinal cord ischemia injury in rats. Rats were divided into four groups: (I) sham-operated control rats, (II) spinal cord ischemia group, (III) spinal cord ischemia group performed syringic acid, and (IV) spinal cord ischemia group performed methylprednisolone intraperitoneally. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. A significant decrease was seen in malondialdehyde levels in group III as compared to group II (P < 0.05). Besides these, nuclear respiratory factor-1 and superoxide dismutase activity of group III were significantly higher than group II (P < 0.05). In histopathological samples, when group III was compared with group II, there was a significant decrease in numbers of apoptotic neurons (P < 0.05). In immunohistochemical staining, BECN1 and caspase-3-immunopositive neurons were significantly decreased in group III compared with group II (P < 0.05). The neurological deficit scores of group III were significantly higher than group II at twenty-fourth hour of ischemia (P < 0.05). Our study revealed that syringic acid pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required for syringic acid to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future.

Neuroprotective effects of daidzein on focal cerebral ischemia injury in rats.

Daidzein, a plant extract, has antioxidant activity. It is hypothesized, in this study, that daidzein exhibits neuroprotective effects on cerebral ischemia. Rat models of middle cerebral artery occlusion were intraperitoneally administered daidzein. Biochemical and immunohistochemical tests showed that superoxide dismutase and nuclear respiratory factor 1 expression levels in the brain tissue decreased after ischemia and they increased obviously after daidzein administration; malondialdehyde level and apoptosis-related cysteine peptidase caspase-3 and caspase-9 immunoreactivity in the brain tissue increased after ischemia and they decreased obviously after daidzein administration. Hematoxylin-eosin staining and luxol fast blue staining results showed that intraperitoneal administration of daidzein markedly alleviated neuronal damage in the ischemic brain tissue. These findings suggest that daidzein exhibits neuroprotective effects on ischemic brain tissue by decreasing oxygen free radical production, which validates the aforementioned hypothesis.

The protective effect of syringic acid on ischemia injury in rat brain.

BACKGROUND/AIM: Brain ischemia and treatment are important topics in neurological science. Free oxygen radicals and inflammation formed after ischemia are accepted as the most significant causes of damage. Currently there are studies on many chemopreventive agents to prevent cerebral ischemia damage. Our aim is to research the preventive effect of the active ingredient in syringic acid, previously unstudied, on oxidative damage in cerebral ischemia. MATERIALS AND METHODS: The rats were randomly divided into 4 groups: control group (no medication or surgical procedure), sham group (artery occlusion), artery occlusion + syringic acid group sacrificed at 6 h, and artery occlusion + syringic acid group sacrificed at 24 h. Obtained brain tissue from the right hemisphere was investigated histopathologically and for tissue biochemistry. RESULTS: Superoxide dismutase and nuclear respiratory factor 1 values decreased after ischemia and they increased after syringic acid treatment, while increased malondialdehyde levels after ischemia were reduced after treatment. Caspase-3 and caspase-9 values increased after ischemia and decreased after treatment; this reduction was more pronounced at 24 h. CONCLUSION: Our study revealed that syringic acid treatment in cerebral ischemia reduced oxidative stress and neuronal degeneration. In the light of the biochemical and histopathologic results of the present study, we think that syringic acid treatment may be an alternative treatment method.

The Neuroprotective Effect of Glycyrrhizic Acid on an Experimental Model of Focal Cerebral Ischemia in Rats.

Cerebral ischemia is still one of the most important topics in neurosciences. Our study aimed to investigate the neuroprotective and anti-oxidant effects of glycyrrhizic acid on focal cerebral ischemia in rats. Twenty-four rats were divided equally into three groups. A middle cerebral artery occlusion model was performed in this study where sham and glycyrrhizic acid were administered intraperitoneally following middle cerebral artery occlusion. Group I was evaluated as control. Malondialdehyde (MDA), superoxide dismutase (SOD), and nuclear respiratory factor-1 (NRF1) levels were analyzed biochemically on the right cerebral hemisphere, while ischemic histopathological studies were completed to investigate the anti-oxidant status. Biochemical results showed that SOD and NRF1 levels were significantly increased in the glycyrrhizic acid group compared with the sham group while MDA levels were significantly decreased. On histopathological examination, cerebral edema, vacuolization, degeneration, and destruction of neurons were decreased in the glycyrrhizic acid group compared with the sham group. Cerebral ischemia was attenuated by glycyrrhizic acid administration. These observations indicate that glycyrrhizic acid may have potential as a therapeutic agent in cerebral ischemia by preventing oxidative stress.

Effects of Tannic Acid on the Ischemic Brain Tissue of Rats.

Many studies of brain ischemia have shown the role played by massive ischemia-induced production of reactive oxygen species, the main mechanism of neuronal death. However, currently, there is no treatment choice to prevent cell death triggered by reactive oxygen species. In our study, we researched the effects of tannic acid, an antioxidant, on the ischemic tissue of rats with induced middle cerebral artery occlusion. The animals were divided into three groups of eight animals. The sham group were only administered 10 % ethanol intraperitoneally, the second group had middle cerebral artery occlusion induced and were given 10 % ethanol intraperitoneally, while the third group had middle cerebral artery occlusion with 10 mg/kg dose tannic acid dissolved in 10 % ethanol administered within half an hour intraperitoneally. The rats were sacrificed 24 h later, and brain tissue was examined biochemically and histopathologically. Biochemical evaluation of brain tissue found that comparing the ischemic group with no treatment with the tannic acid-treated ischemia group; the superoxide dismutase (SOD) levels were higher, malondialdehyde (MDA) levels were lower, and nuclear respiratory factor-1 (NRF-1) was higher in the tannic acid-treated group. Histopathological examination showed that the histopathological results of the tannic acid group were better than the group not given tannic acid. Biochemical and histopathological results showed that tannic acid administration had an antioxidant effect on the negative effects of ischemia in brain tissue.