Objective
To analyze the early complications and causes of oblique lateral interbody fusion, and put forward preventive measures.
Methods
There were 235 patients (79 males and 156 females) analyzed ...in our study from October 2014 to May 2017. The average age was 61.9 ± 0.21 years (from 32 to 83 years). Ninety‐one cases were treated with oblique lateral interbody fusion (OLIF) alone (OLIF alone group) and 144 with OLIF combined with posterior pedicle screw fixation through the intermuscular space approach (OLIF combined group). In addition, 137/144 cases in the combined group were primarily treated by posterior pedicle screw fixation, while the treatments were postponed in 7 cases. There were 190 cases of single fusion segments, 11 of 2 segments, 21 of 3 segments, and 13 of 4 segments. Intraoperative and postoperative complications were observed.
Results
Average follow‐up time was 15.6 ± 7.5 months (ranged from 6 to 36 months). Five cases were lost to follow‐up (2 cases from the OLIF alone group and 3 cases from the OLIF combined group). There were 7 cases of vascular injury, 22 cases of endplate damage, 2 cases of vertebral body fracture, 11 cases of nerve injury, 18 cases of cage sedimentation or cage transverse shifting, 3 cases of iliac crest pain, 1 case of right psoas major hematoma, 2 cases of incomplete ileus, 1 case of acute heart failure, 1 case of cerebral infarction, 3 case of left lower abdominal pain, 9 cases of transient psoas weakness, 3 cases of transient quadriceps weakness, and 8 cases of reoperation. The complication incidence was 32.34%. Thirty‐three cases occurred in the OLIF alone group, with a rate of 36.26%, and 43 cases in the group of OLIF combined posterior pedicle screw fixation, with a rate of 29.86%. Fifty‐seven cases occurred in single‐segment fusion, with a rate of 30.0% (57/190), 4 cases occurred in two‐segment fusion, with a rate of 36.36% (4/11), 9 cases occurred in three‐segment fusion, with a rate of 42.86% (9/21), and 6 cases occurred in four‐segment fusion, with a rate of 46.15% (6/13).
Conclusion
In summary, OLIF is a relatively safe and very effective technique for minimally invasive lumbar fusion. Nonetheless, it should be noted that OLIF carries the risk of complications, especially in the early stage of development.
Emerging evidence indicates that circRNAs are broadly expressed in osteosarcoma (OS) cells and play a crucial role in OS progression. Recently, cancer-specific circRNA circPRKAR1B has been identified ...by high-throughput sequencing and is recorded in publicly available databases. Nevertheless, the detailed functions and underlying mechanisms of circPRKAR1B in OS remains poorly understood. By functional experiments, we found that circPRKAR1B enhanced OS cell proliferation, migration, and promotes OS epithelial-mesenchymal transition (EMT). Mechanistic investigations suggested that circPRKAR1B promotes OS progression through sponging miR-361-3p to modulate the expression of FZD4. Subsequently, we identified that EIF4A3 promoted cirPRKAR1B formation through binding to the downstream target of circPRKAR1B on PRKAR1B mRNA. Further rescue study revealed that overexpression of the Wnt signalling could impair the onco-suppressor activities of the silencing of circPRKAR1B. Interestingly, further experiments indicated that circPRKAR1B is involved in the sensitivity of chemoresistance in OS. On the whole, our results demonstrated that circPRKAR1B exerted oncogenic roles in OS and suggested the circPRKAR1B/miR-361-3p/FZD4 axis plays an important role in OS progression and might be a potential therapeutic target.
Multifidus muscle injury and atrophy are common after posterior lumbar spine surgery and are associated with low back pain and functional disability. In theory, muscle-splitting and retraction with a ...self-retaining retractor are considered to be the major surgical factors. The effects and mechanisms of retraction have been well studied, but the exact effect and possible mechanism of injury and atrophy after muscle-splitting still lack experimental evidence.
New Zealand White rabbits were divided into two groups. In group S, through a skin and lumbodorsal fascial incision, the bilateral multifidus muscles were dissected from the osseous structures in the standard fashion, while in group C, only a skin and lumbodorsal fascial incision was made. In each group, the multifidus muscle was evaluated by magnetic resonance imaging (MRI) and by histological analysis at three and forty-eight hours and at one, three, six, twelve, and twenty-four weeks after surgery.
In group C, there was no injury or atrophy of the multifidus muscle after surgery. In group S, the mean T2-weighted signal intensity ratios of gross multifidus to psoas on fat-suppressed T2-weighted cross-sectional MRI scans peaked on week 3 and returned to baseline on week 24. Necrosis and inflammation of the multifidus muscle were evident and became more severe at one week. Fibrotic change was mainly seen at three and six weeks after surgery, and fatty degeneration mainly occurred at twelve and twenty-four weeks. Decreased acetylcholine activity and granular degeneration of the neuromuscular junction were observed at all follow-up times, and the numbers of degenerating neuromuscular junctions increased significantly with time after surgery.
The splitting approach is an important cause of multifidus muscle injury and atrophy in posterior lumbar spine surgery. Denervation and disuse may be important factors in multifidus muscle atrophy in the splitting approach.
This study provides a basis for the prevention of multifidus muscle injury and atrophy after posterior lumbar surgery.
A reliability study was conducted.
To estimate the intra- and intermeasurement errors in the measurements of functional cross-sectional area (FCSA), density, and T2 signal intensity of paraspinal ...muscles using computed tomography (CT) scan and magnetic resonance imaging (MRI).
CT scan and MRI had been used widely to measure the cross-sectional area and degeneration of the back muscles in spine and muscle research. But there is still no systemic study to analyze the reliability of these measurements.
This study measured the FCSA and fatty infiltration (density on CT scan and T2 signal intensity on MRI) of the paraspinal muscles at L3-L4, L4-L5, and L5-S1 in 29 patients with chronic low back pain. Two experienced musculoskeletal radiologists and one superior spine surgeon traced the region of interest twice within 3 weeks for measurement of the intra- and interobserver reliability.
The intraclass correlation coefficients (ICCs) of the intra-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. The ICCs of the inter-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. There were no significant differences between CT scan and MRI in reliability results, except in the relative standard error of fatty infiltration measurement. The ICCs of the FCSA measurement between CT scan and MRI ranged from poor to good.
The reliabilities of the CT scan and MRI for measuring the FCSA and fatty infiltration of the atrophied lumbar paraspinal muscles were acceptable. It was reliable for using uniform one image method for a single paraspinal muscle evaluation study. And the authors preferred to advise the MRI other than CT scan for paraspinal muscles measurements of FCSA and fatty infiltration.
The valveless micropump based on dual synthetic jets is a potential fluid pumping device that has the ability to transport fluid continuously. In order to improve the performance of this device, a ...novel valveless continuous micropump based on dual synthetic jets with a Tesla structure was proposed by combining a double Tesla symmetrical nozzle and a dual synthetic jets actuator. The mechanism of the novel micropump and its flow field characteristics were analyzed, combined with numerical simulation and a PIV experiment. The performance of the novel micropump was compared with that of a dual synthetic jet micropump based on a traditional shrinking nozzle. The novel micropump achieved continuous flow with a larger and more stable flow rate in one cycle. The maximum pump flow speed reached 12 m/s. Compared with the traditional type, the pump flow rate was increased by 5.27% and the pump flow pulsation was reduced by 214.93%. The backflow and vortex inside the nozzle were prevented and inhibited effectively by the Tesla structure. The velocity and influence range of the pump flow increased with the intensification of driving voltage in a certain range.
Objective
The aim of the present paper was to evaluate cases of lumbar degenerative diseases treated with oblique lateral interbody fusion (OLIF) using a modified lateral approach (i.e. ...anteroinferior psoas exposure under direct vision) and to analyze the effect and safety of this approach.
Methods
From June 2016 to April 2019, a total of 226 patients with an average age of 65.5 ± 16.2 years (98 men and 128 women) with degenerative lumbar diseases who underwent the AIP approach of OLIF were followed up and analyzed retrospectively. Data concerning operative and clinical parameters were collected, including operative time, intraoperative estimated blood loss, duration of postoperative hospital stay, and time to ambulation after surgery. For the assessment of clinical outcomes, the visual analogue scale (VAS) score (for back pain) and the Oswestry disability index (ODI) were calculated. Complications were also recorded as surgical exposure approach‐related complications. More than 6 months after surgery, 132 patients consented to having MRI examinations to evaluate the psoas muscle atrophy when they were followed up.
Results
The mean operative time was 82.5 ± 31.6 min. The mean operative time for each segment of OLIF was 43.3 ± 15.5 min. The mean blood loss was 48.0 ± 11.6 mL. The mean blood loss for each segment of OLIF was 25.3 ± 10.1 mL. No patients needed blood transfusion intraoperatively or postoperatively. The mean hospital stay was 4.1 ± 2.1 days. All patients were followed up for 12–31 months (mean 18.2 months). Clinical assessment showed that the VAS and ODI scores at 6 months after surgery were markedly lower than the preoperative scores (P < 0.001) but did not differ from the scores at the final follow‐up (P > 0.05). There was no significant difference in percentage changes of the cross‐sectional area of the lean psoas muscle and the T2 signal intensity ratio of gross psoas to quadratus lumborum muscles between the left side (operative side) and the right side (nonoperative side) (P > 0.05). A total of 11 surgical exposure approach‐related complications were reported, with an incidence of 4.9%: transient thigh pain/numbness, psoas weakness (2.2%), sympathetic chain injury (1.3%), cage subsidence (0.9%), and segmental artery injury (0.4%). There was no permanent motor neurological deficit, and no injury of vascular, ureter or peritoneal membranes.
Conclusion
The anteroinferior psoas approach for OLIF is safe and can preserve the psoas and lumbar plexus.
We presented a modified lateral approach (i.e. anteroinferior psoas exposure under direct vision) for OLIF and found that it is safe and can preserve the psoas and the lumbar plexus.
Objective
Surgery is indicated when antibiotic treatment fails in pyogenic spondylodiscitis, which is caused by pathogens such as the Staphylococcus species. The aim of the present study was to ...investigate the efficacy and safety of the oblique lateral interbody fusion (OLIF) corridor approach combined with posterior pedicle screw fixation for treating pyogenic spondylodiscitis.
Methods
This was a retrospective case series study. A total of 11 patients with an average age of 60.7 years (range, 40–70 years; 10 males and 1 females) with lumbar pyogenic spondylodiscitis who underwent single‐stage debridement and reconstruction using the OLIF corridor combined with posterior pedicle screw fixation were recruited in our study from June 2016 to July 2017. All patients had single‐level pyogenic spondylodiscitis between T12 and L5. The baseline data, perioperative outcomes (operative time, intra‐operative blood loss, and intra‐operative complication), postoperative laboratory tests (erythrocyte sedimentation rate ESR, C‐reactive protein CRP, white blood count WBC, and tissue culture results), long‐term complications (recurrence, fixation failure, and bony non‐fusion rates), and duration of antibiotic administration were reviewed. Outcomes evaluated using a variety of scales including visual analog scale (VAS) score and Oswestry disability index (ODI), were compared pre‐operatively and post‐operatively.
Results
The mean follow‐up period of time was 18.3 months. The average operative time and intra‐operative blood loss were 217.0 ± 91.91 min and 220.9 ± 166.10 mL, respectively. There were no intra‐operative complications, except in 1 patient who encountered somatosensory evoked potentials changes and 1 patient who had motor evoked potentials changes, both without post‐surgery neurological deficits. Causative organisms were identified in 4 patients: Staphylococcus aureus in 1 patient and Streptococcus in 3 patients. At approximately 8.8 weeks after surgery, WBC, CRP, and ESR had returned to normal levels. All patients were pain free with no recurring infection. There was no fixation failure during follow up. Solid bony fusions were observed in all cases within 6 months. At the final follow up, the mean VAS (0.6 ± 0.69) and ODI (14.4 ± 4.27) were significantly lower than those before surgery (P < 0.05).
Conclusion
One‐stage debridement with autogenous iliac bone graft through the OLIF corridor combined with posterior pedicle screw fixation is effective and safe for single‐level spontaneous lumbar pyogenic spondylodiscitis after antibiotic treatment fails.
Asphaltene deposition is a common phenomenon during CO2 flooding in ultralow permeability reservoirs. The deposited asphaltene occupies the pore volume and decreases permeability, resulting in ...serious formation damage and pore well productivity. It is urgent to investigate the asphaltene deposition mechanisms, adverse effects, and preventive measures. However, few asphaltene deposition investigations have been systematically conducted by now. In this research, the asphaltene precipitation mechanisms and adverse effects were comprehensively investigated by using experimental and numerical methods. To study the effects of pressure, asphaltene content, and temperature on asphaltene precipitation qualitatively and quantitatively, the microscope visible detection experiment and the PVT cell static experiment were firstly conducted. The adverse effects on porosity and permeability resulted from asphaltene deposition were also studied by the core flooding experiment. Secondly, simulation models of asphaltene precipitation and deposition were developed and validated by experimental data. Finally, a case study from Changqing oil field was presented to analyze the asphaltene deposition characteristic and preventive measures. The experimental results showed that the asphaltene precipitation increases with the increased pressure before reaching the minimum miscible pressure (MMP) and gets the peak value around the MMP, while decreases slowly. The asphaltene precipitation increases with the increased temperature and asphaltene content. The variation trend of adverse effects on porosity and permeability resulted from asphaltene deposition is similar to that of asphaltene precipitation under the influence of pressure, asphaltene content, and temperature. The case study shows that the water-altering-gas (WAG) with high injection rate suffers more serious asphaltene deposition compared with the WAG with low injection rate, for the asphaltene precipitation increases as the increased pressure before reaching the MMP. The CO2 continuous injection with high injection rate is the worst choice, for low sweep efficiency and the most severe formation damage. Thus, the WAG with optimal injection rate was proposed to maintain well productivity and to reduce formation damage resulted from asphaltene deposition during developing ultralow permeability reservoirs.
Oblique lateral lumbar interbody fusion (OLIF) has been extensively used, with satisfactory outcomes for the treatment of degenerative lumbar disease. This article aims to demonstrate a modified ...lateral approach, also known as the anteroinferior psoas (AIP) technique for OLIF, which is expected to enhance security by operating under direct vision. The core procedures of our technique are as follows. First, a minimal skin incision is recommended 2 cm backward compared with the normal incision of OLIF, facilitating the oblique placement of the working channel and the orthogonal maneuver for the cage placement. Second, two special custom‐made retractors, as an alternative to the index finger, are used to pull the psoas muscle to the dorsal side and pull the abdominal organs together with extraperitoneal fate to the ventral side under direct visualization, making the exposure of the working channel convenient and safe and avoiding radiation exposure. Third, the anterior border of the psoas is bluntly dissected and retracted backwards, obviously enlarging the retroperitoneal anatomic corridor and then expanding clinical indications of OLIF. The benefits of this technique include that it has a short learning curve, satisfactory clinical outcomes, and low risk of perioperative complications.
Preoperative static and dynamic anteroposterior radiograph of the lumbar spine. Mild forward slippage of L4, which manifested as instability in lumbar dynamic position, scoliosis, and degenerative change with osteoporosis.
The treatment of chronic wound is an important topic of current clinical issue. Neovascularization plays a crucial role in skin wound healing by delivering fresh nutrients and oxygen to the wound ...area. The aim of this study was to investigate the mechanisms of urolithin A (UA) in angiogenesis during wound healing. The results of
experiments showed that treatment with UA (5-20 μM) promoted the proliferation, migration, and angiogenic capacity of HUVECs. Furthermore, we investigated the effect of UA
using a full-thickness skin wound model. Subsequently, we found that UA promoted the regeneration of new blood vessels, which is consistent with the results of accelerated angiogenesis
experiments. After UA treatment, the blood vessels in the wound are rapidly formed, and the deposition and remodeling process of the collagen matrix is also accelerated, which ultimately promotes the effective wound healing. Mechanistic studies have shown that UA promotes angiogenesis by inhibiting the PI3K/AKT pathway. Our study provides evidence that UA can promote angiogenesis and skin regeneration in chronic wounds, especially ischemic wounds.
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