Assessing the characteristics of different-sized particles in the first flush of roof runoff.

The first flush occurs during urban runoff events. In this study, we aimed to assess the characteristics of different-sized particles in the first flush of roof runoff, and runoff was collected from an asphalt roof (AR), metal roof (MR), and cement roof (CR) for analysis. There were no clear patterns in the particle size distributions in the runoff from the three roofs and were affected by several factors. The strength of the first flushes differed significantly for particles in different size categories in AR, MR, and CR runoff and were very different from suspended solids (SS). The comparison showed that it would be possible to meet the SS control design expectation required by the Chinese national standard for runoff pollution control (VFF = 3 mm) for particles <45 µm but not for particles >45 µm. The methods presented provide an alternative for assessing the ability to control the transport of different-sized particles in runoff.

Influence of urban runoff pollutant first flush strength on bioretention pollutant removal performance.

Bioretention is commonly used for runoff pollution control. The first flush strength of pollutants can affect bioretention performance. To examine the influence of the first flush strength on bioretention performance, bioretention columns filled with garden soil as the main media were established. Activated carbon and water treatment residuals (WTR) were added and compared for their ability to enhance phosphorus removal. Waste edible fungus culture medium (WEFCM) as a carbon source was also explored. When WEFCM was used as a carbon source instead of wood chips, total nitrogen (TN) removal increased from 60.83 ± 21.22 to 62.21 ± 16.43%, but chemical oxygen demand (COD) leaching was observed. WTR was better able than activated carbon to enhance phosphorus removal (87.97 ± 8.87 vs. 81.66 ± 9.27%) without impacting TN removal. NH4+-N removal increased with increasing first flush strength, but there was no trend for suspended solids (SS), COD, TN, or total phosphorus. First leaching phenomenon in bioretention outflow was proposed in this study. A low first leaching was observed in the outflow when the inflow had a uniform pollutant mass (i.e., no first flush) because of media leaching. A weak first leaching outflow was observed for SS and COD when they were present at strong first flush inflow.

Pollutant first flush identification and its implications for urban runoff pollution control: a roof and road runoff case study in Beijing, China.

First flush is a common phenomenon in urban runoff pollution. Typical cement roof and asphalt road runoff in Beijing, China were monitored for 2 years. Based on the M(v) curve, the suspended solids (SS), chemical oxygen demand (COD), total phosphorus (TP) and particulate phosphorus in cement roof runoff presented a stronger first flush than those in asphalt road runoff. The first flush volume (VFF) of SS, COD, total nitrogen (TN) and TP in asphalt road runoff differed slightly from the cement roof. There were also differences in the first flush assessment depending on which method was used. We proposed a new method based on the runoff depth versus pollutant cumulative mass curve. According to the national standards in China (VFF = 3 mm), various masses of different pollutants, such as 91.42 ± 9.80% (cement roof) and 78.49 ± 19.41% (asphalt road) of SS and 86.85 ± 13.54% (cement roof) and 72.80 ± 25.79% (asphalt road) of COD, can be effectively controlled, but our mass control efficiencies were 55.91%-66.65% when VFF = 1 mm. The new method proposed in this study provides an alternative approach for assessing runoff pollution control efficiency of different VFF.

Endovascular Treatment of Iliac Artery Stenosis Caused by Takayasu Arteritis: A 10-Year Experience.

Purpose: To evaluate the safety and efficacy of endovascular treatment for iliac artery stenosis caused by Takayasu arteritis (TA). Methods: Twenty-three consecutive TA patients (mean age 28.6±9.5 years; 17 women) with 30 iliac artery stenoses underwent percutaneous transluminal angioplasty (PTA) and selective stent implantation between January 2007 and December 2016. All had claudication (Rutherford category 2 or 3). The changes in the Rutherford category, ankle-brachial index (ABI), 6-minute walking capacity, and adverse events were assessed. Results: The success rate of endovascular therapy for iliac artery lesions was 93.3% (28/30). Guidewires could not cross either lesion in a patient with bilateral stenoses. Twenty-four lesions were treated by PTA alone and the other 4 lesions with provisional stents. One patient had a puncture site hematoma. Over an average of 4.8±3.3 years, 18 patients remained asymptomatic or had mild intermittent claudication. The other 4 patients developed moderate to severe intermittent claudication due to progression of a previously existing iliac lesion (n=1) or restenosis (n=3); all 4 underwent PTA. At the last follow-up, improvements were seen in the ABI (0.95±0.12 vs 0.51±0.22, p<0.001), 6-minute walking capacity (409.5±46.1 vs 272.6±32.3 m, p<0.001), and the Rutherford category of 22 patients. One patient died of a hemorrhagic stroke at 27 months due to uncontrolled hypertension. Conclusion: Endovascular therapy was safe and effective in treating TA patients with iliac artery stenosis, with good clinical outcomes in the long term.

A pilot bioretention system with commercial activated carbon and river sediment-derived biochar for enhanced nutrient removal from stormwater.

Bioretention is an effective technology for urban stormwater management, but the nutrient removal in conventional bioretention systems is highly variable. Thus, a pilot bioretention column experiment was performed to evaluate the nutrient control of systems with commercial activated carbon and river sediment-derived biochar. Significant chemical oxygen demand (COD) and total phosphorus (TP) leaching were found with the addition of activated carbon and biochar, but total nitrogen (TN) leaching was significantly improved when activated carbon was used as the medium. During a semi-synthetic runoff experiment, the bioretention systems containing two types of fluvial biochar showed relatively better COD and TN control (average mass removal efficiencies and cumulative removal efficiencies) than commercial activated carbon. However, the average TP mass removal efficiency with commercial activated carbon (95% ± 3%) was significantly higher than biochar (48% ± 20% and 56 ± 14%). The addition of biochar in the media increased the nitrogen removal efficiency, and the addition of activated carbon significantly increased the phosphorous removal efficiency. Therefore, both biochar and activated carbon are effective materials for bioretention, and fluvial biochar provides an alternative approach to comprehensively utilize river sediment.

Clinical outcomes and influencing factors of in-stent restenosis after stenting for symptomatic stenosis of the vertebral V1 segment.

OBJECTIVE: The objective of this study was to evaluate 30-day and long-term clinical outcomes and influencing factors of in-stent restenosis (ISR) after stenting for symptomatic stenosis of the vertebral V1 segment. METHODS: The clinical and follow-up data of 301 consecutive patients (mean age, 64 ± 8 years; 252 men) with symptomatic V1 stenosis who underwent stenting at the Fuwai Hospital between January 2010 and June 2016 were collected retrospectively. The 30-day and long-term follow-up of stroke and death after stenting and the recurrence of symptoms, ISR, and repeated revascularization were assessed. RESULTS: Technical success was 100%. The mean stenosis of lesions was reduced from 82.8% ± 7.6% to 4.4% ± 4.0% immediately after 312 stents (165 bare-metal stents [BMSs] and 147 drug-eluting stents) were implanted. The overall risk of combined any stroke and death was 1.0% (3/301) within 30 days after stenting. The rates of freedom from any stroke and death were 98.2%, 96.8%, and 91.4% at 1 year, 3 years, and 5 years, respectively. After a mean follow-up of 2.9 ± 1.5 years, 46 (15.8%) patients developed ISR, of whom 19 (6.5%) were symptomatic. Twenty-two (7.6%) patients with ISR underwent repeated revascularization. The primary and assisted patency rates were 90.0% and 95.4%, 82.6% and 90.3%, and 80.3% and 87.9% at 1 year, 3 years, and 5 years, respectively. BMS (hazard ratio, 2.02; 95% confidence interval, 1.01-4.06; P < .05) and diabetes (hazard ratio, 1.87; 95% confidence interval, 1.04-3.37; P = .04) were independently associated with an increased risk of ISR. CONCLUSIONS: Percutaneous stent placement for symptomatic V1 stenosis is safe and associated with a good long-term patency rate. BMS and diabetes are independent predictive factors of ISR.

Nutrient leaching from extensive green roofs with different substrate compositions: a laboratory study.

To investigate nutrient leaching from extensive green roofs, green roof platforms were established to investigate the effluent quantity and quality during artificial rainfall. When the influent volume reached three times the empty bed volume, for which the cumulative rainfall was around 300 mm, the effluent TP and COD concentrations of green roof platforms filled with peat soil did not tend to stabilize. For a long-term operation, the substrate depths had little significant influence on TN, TP and COD concentrations of the green roof effluents. A normalized cumulative emission process method was proposed to discuss the difference in various pollutant leaching processes. Obvious differences in the leaching process of different contaminants for green roof platforms filled with various substrates were observed. For the green roof filled with modified substrates, the nitrogen and phosphorus pollutant leaching rates were relatively high in the initial stage of green roof operation and the phosphorus leaching rate was higher than that of nitrogen. The green roof is a sink for TN, but not for TP and COD in this study. The outcomes are critical for the selection of green roof substrates and also contribute to green roof maintenance.

A laboratory study to determine the use of polluted river sediment as a substrate for extensive green roofs.

In this study, laboratory-scale green (e.g. living) roof platforms were established to assess the potential use of polluted river sediment in their substrate mixture. The mean runoff retention of the green roof platforms, which contained peat and/or river sediment, after 11 artificial rainfall events was >72%, significantly higher than traditional roofs. However, green roof platforms that had been filled with peat soil showed chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) leaching. Green roofs that had used river sediment showed good leaching control for COD, TN and TP. The cumulative leaching masses from the green roofs contained 30% (COD), 42% (TN) and 47% (TP) as much as the total leaching mass from traditional roofs, and the Cu, Zn, Cd and Pb leaching risk from green roofs when river sediments are used as part of a substrate mixture was relatively low. Despite some nutrient leaching in the initial phase of runoff from the green roofs, river sediment has the potential to be used as a substrate for extensive green roofs.

Stenting for left subclavian artery stenosis in patients scheduled for left internal mammary artery-coronary artery bypass grafting.

OBJECTIVES: To evaluate the early and long-term outcomes of stent placement for left subclavian artery stenosis (LSAS) in patients scheduled for left internal mammary artery-coronary artery bypass grafting (LIMA-CABG). BACKGROUND: Few studies have demonstrated the safety and effectiveness of endovascular therapy for the treatment of LSAS before LIMA-CABG; therefore, use of this therapy requires further exploration and evaluation. METHODS: Between February 2000 and April 2014, the clinical data of 167 consecutive patients (mean age 64 ± 9 years, 141 males) scheduled for LIMA-CABG with LSAS who were treated by stenting at the Fuwai Hospital were collected and analyzed retrospectively. RESULTS: The technical success rate of the procedure was 97.6% (163/167). The mean stenosis of target lesions decreased from 86.5 ± 9.9% to 7.6 ± 4.6% (P < 0.001). The incidences of death, stroke, and myocardial infarction, as well as the combined incidence of death, stroke, and myocardial infarction from the time of stenting to 30 days after the stenting procedure were 0.6% (n = 1), 1.8% (n = 3), 0% (n = 0), and 1.8% (n = 3), respectively. The 10-year rate of follow-up was 94.6%. The overall survival rate was 98.8% at 1 year, 97.5% at 2 years, 93.9% at 5 years, and 86.2% at 10 years. A total of 14.1% (23/163) of patients developed in-stent restenosis. Stent restenosis-related angina and myocardial infarction were observed in 13 and 3 patients, respectively. The patency rates of the left subclavian artery were 95.7, 93.8, 86.5, and 75.2% at 1, 2, 5, and 10 years, respectively. The target vessel reconstruction rate was 8.0% (13/163). CONCLUSIONS: Stenting of LSAS at experienced medical centers for patients scheduled for LIMA-CABG was safe and effective with a low incidence of complication and in-stent restenosis.

Single-Level Rigid Fixation Combined with Coflex: A Biomechanical Study.

BACKGROUND: The purpose of this biomechanical in vitro study was to compare the kinematics and intradiscal pressure achieved with 2 methods: L4-L5 pedicle screw-rod fixation (PSRF) with an upper L3-L4 Coflex device and L4-L5 PSRF alone. The results were used to characterize the biomechanics of the topping-off operation with a Coflex device for the lumbar motion segment adjacent to single-level rigid fixation. MATERIAL/METHODS: Six human cadaveric spine specimens were biomechanically tested in vitro (6 males, 0 females). The 3-dimensional specimen motion in response to applied loads during flexibility tests was determined. Loads were applied along anatomic axes to induce flexion-extension, lateral bending, and axial rotation. All specimens were first studied with intact lumbar motion segments, then with L4-L5 PSRF alone, and finally with L4-L5 PSRF with an upper L3-L4 Coflex device. A non-paired comparison of the 3 configurations under 3 different conditions was made. RESULTS: PSRF, with or without a Coflex device, significantly increased the range of motion (ROM) in the upper adjacent motion segments in all directions of loading. The intradiscal pressure (IDP) changed slightly. A correlation analysis showed that the ROM and IDP are significantly positively correlated. The application of the upper motion segment of the Coflex device provided greater stability in all directions of motion than did PSRF alone, particularly for extension (p<0.05), while use of a Coflex device did not significantly decrease the IDP compared with PSRF alone (p>0.05). CONCLUSIONS: These results suggest that L4-L5 PSRF with an L3-L4 Coflex device is more stable than L4-L5 PSRF alone. PSRF with an upper Coflex device is a promising alternative to PSRF alone. Based on these biomechanical tests, it might be considered a protective method to prevent adjacent segment degeneration (ASD), although some limitations with this in vitro study must be addressed in the future.

Discussion about initial runoff and volume capture ratio of annual rainfall.

In recent years, runoff pollution from urban areas has become a major concern all over the world. But there exists a worldwide confusion about how much stormwater should be captured for the purpose of runoff pollution control. Furthermore, the construction cost and pollution control efficiency are closely linked with the size of stormwater facilities, which is then related to the first flush (FF) phenomenon and volume capture ratio of annual rainfall (VCRa). Based on this background, analysis of the random and changeable characteristics of the occurrence of FF was carried out first, which was proved to vary with catchment characteristics and pollutant types. Secondly, the distribution of design rainfall depth toward 85% VCRa in China and its causes have been analyzed. Thirdly, the relationship between initial runoff and VCRa has been studied at both conceptual and numerical levels, and the change rule of VCRa along with design rainfall depth in different regions has been studied. The limitation of initial runoff has been illustrated from the perspective of runoff characteristics of single rainfall events in the first part, and from the perspective of regional differences in the two subsequent parts.

Integral stormwater management master plan and design in an ecological community.

Urban stormwater runoff nearly discharges directly into bodies of water through gray infrastructure in China, such as sewers, impermeable ditches, and pump stations. As urban flooding, water shortage, and other environment problems become serious, integrated water environment management is becoming increasingly complex and challenging. At more than 200ha, the Oriental Sun City community is a large retirement community located in the eastern side of Beijing. During the beginning of its construction, the project faced a series of serious water environment crises such as eutrophication, flood risk, water shortage, and high maintenance costs. To address these issues, an integral stormwater management master plan was developed based on the concept of low impact development (LID). A large number of LID and green stormwater infrastructure (GSI) approaches were designed and applied in the community to replace traditional stormwater drainage systems completely. These approaches mainly included bioretention (which captured nearly 85th percentile volume of the annual runoff in the site, nearly 5.4×10(5)m(3) annually), swales (which functioned as a substitute for traditional stormwater pipes), waterscapes, and stormwater wetlands. Finally, a stormwater system plan was proposed by integrating with the gray water system, landscape planning, an architectural master plan, and related consultations that supported the entire construction period. After more than 10 years of planning, designing, construction, and operation, Oriental Sun City has become one of the earliest modern large-scale LID communities in China. Moreover, the project not only addressed the crisis efficiently and effectively, but also yielded economic and ecological benefits.

Percutaneous Transforaminal Endoscopic Surgery (PTES) for Treatment of Lumbar Degenerative Disease in Patients with Underlying Diseases: A Retrospective Cohort Study of 196 Cases.

Objective: To evaluate the postoperative outcomes, safety and feasibility of percutaneous transforaminal endoscopic surgery (PTES) for the treatment of lumbar degenerative disease (LDD) in the patients with underlying diseases. Methods: From June 2017 to April 2019, PTES was performed to treat 226 patients of single-level LDD. According to clinical background, the patients were divided into two groups. A total of 102 patients with underlying diseases were included in group A. The other 124 LDD patients without underlying diseases were included in group B. The occurrence of postoperative complications was recorded. Leg pain was assessed before, immediately, 1 month, 2 months, 3 months, 6 months, 1 year, and 2 years after PTES using VAS, and ODI before PTES and 2 years after PTES were recorded. The therapeutic quality (Excellent, Good, Moderate or Poor) was defined according to MacNab grade at 2-year follow-up. Results: No aggravation of underlying diseases or serious complications was observed in all patients within 6 months after the operation. Altogether, 196 patients were followed up for more than 2 years, 89 patients in group A and 107 patients in group B. The VAS score of leg pain and ODI dropped significantly after surgery (P<0.001) in both groups. One case of group B received PTES again due to recurrence 52 months after surgery. According to MacNab, the excellent and good rate was 97.75% (87/89) in group A and 96.26% (103/107) in group B. In operative duration, frequency of intraoperative fluoroscopy, blood loss, incision length, hospital stay, VAS, ODI, and the excellent and good rate, there was no statistical difference between the two groups. Conclusion: PTES is safe, effective and feasible for the treatment of LDD with underlying diseases, which is comparable to PTES for LDD without underlying diseases. The entrance point of PTES (Gu's Point) is located at the corner of the flat back turning to the lateral side. PTES is not only a minimally invasive surgical technique but also includes a postoperative care system for preventing LDD recurrence.

The identification and expression pattern of the sex determination genes and their sex-specific variants in the egg parasitoid Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae).

Introduction: Trichogramma wasps are egg parasitoids of agricultural lepidopteran pests. The sex of Trichogramma is determined by its ploidy as well as certain sex ratio distorters, such as the endosymbiotic bacteria Wolbachia spp. and the paternal sex ratio (PSR) chromosome. The sex determination systems of hymenopterans, such as Trichogramma spp., involve cascades of the genes transformer (tra), transformer-2 (tra2), and doublesex (dsx) and are associated with sex-specific tra and dsx splicing. First, these genes and their sex-specific variants must be identified to elucidate the interactions between the sex ratio disorders and the sex determination mechanism of Trichogramma. Methods: Here, we characterized the sex determination genes tra, tra2, and dsx in Trichogramma dendrolimi. Sex-specific tra and dsx variants were detected in cDNA samples obtained from both male and female Trichogramma wasps. They were observed in the early embryos (1-10 h), late embryos (12-20 h), larvae (32 h and 48 h), pre-pupae (96 h), and pupae (144 h, 168 h, 192 h, and 216 h) of both male and female T. dendrolimi offspring. Results: We detected female-specific tra variants throughout the entire early female offspring stage. The male-specific variant began to express at 9-10 h as the egg was not fertilized. However, we did not find any maternally derived, female-specific tra variant in the early male embryo. This observation suggests that the female-specific tra variant expressed in the female embryo at 1-9 h may not have originated from the maternal female wasp. Discussion: The present study might be the first to identify the sex determination genes and sex-specific gene splicing in Trichogramma wasps. The findings of this study lay the foundation for investigating the sex determination mechanisms of Trichogramma and other wasps. They also facilitate sex identification in immature T. dendrolimi and the application of this important egg parasitoid in biological insect pest control programs.

RNA Interference in the Egg Parasitoid, Trichogramma dendrolimi Matsumura.

The egg parasitoids, Trichogramma spp, are recognized as efficient biological control agents against various lepidopteran pests in agriculture and forests. The immature stages of Trichogramma offspring develop within the host egg, exhibiting remarkable diminutiveness (approximately 0.5 mm in adult length). RNA-interference (RNAi) methodology has emerged as a crucial tool for elucidating gene functions in numerous organisms. However, manipulating RNAi in certain small parasitoid species, such as Trichogramma, has generally posed significant challenges. In this study, we present an efficient RNAi method in Trichogramma denrolimi. The outlined procedure encompasses the acquisition and isolation of individual T. dendrolimi specimens from host eggs, the design and synthesis of double-stranded RNA (dsRNA), the in vitro transplantation and cultivation of T. dendrolimi pupae, the micro-injection of dsRNA, and the subsequent assessment of target gene knockdown through RT-qPCR analysis. This study furnishes a comprehensive, visually detailed procedure for conducting RNAi experiments in T. dendrolimi, thereby enabling researchers to investigate the gene regulation in this species. Furthermore, this methodology is adaptable for RNAi studies or micro-injections in other Trichogramma species with minor adjustments, rendering it a valuable reference for conducting RNAi experiments in other endoparasitic species.

Posterior concentration of Wolbachia during the early embryogenesis of the host dynamically shapes the tissue tropism of Wolbachia in host Trichogramma wasps.

Introduction: The bacterial endosymbiont, Wolbachia spp. induce thelytokous parthenogenesis in certain parasitoid wasps, such as the egg parasitoid wasps Trichogramma spp. To complete the cycle of vertical transmission, Wolbachia displays efficient transovarial transmission by targeting the reproductive tissues and often exhibits strong tissue-specific tropism in their host. Method: The present study aimed to describe the basic Wolbachia distribution patterns that occur during the development of Wolbachia-infected, thelytokous Trichogramma dendrolimi, and T. pretiosum. We used fluorescence in situ hybridization (FISH) to investigate Wolbachia signal dynamics during early embryogenesis (from 30 to 120 min). Wolbachia titers and distributions from the embryo to adult stages of Trichogramma after early embryogenesis were detected by absolute quantitative polymerase chain reaction (AQ-PCR) and FISH. The symmetry ratios (SR) of the Wolbachia signals were calculated using the SR odds ratios in the anterior and posterior parts of the host. The SR was determined to describe Wolbachia tropism during early embryogenesis and various developmental stages of Trichogramma. Results: Wolbachia was concentrated in the posterior part of the embryo during early embryogenesis and the various developmental stages of both T. dendrolimi and T. pretiosum. Wolbachia density increased with the number of nuclei and the initial mitotic division frequency during early embryogenesis. The total Wolbachia titer increased with postembryogenesis development in both T. dendrolimi and T. pretiosum. However, the Wolbachia densities relative to body size were significantly lower at the adult and pupal stages than they were at the embryonic stage. Discussion: The present work revealed that posterior Wolbachia concentration during early host embryogenesis determined Wolbachia localization in adult wasps. By this mechanism, Wolbachia exhibits efficient vertical transmission across generations by depositing only female Wolbachia-infected offspring. The results of this study describe the dynamics of Wolbachia during the development of their Trichogramma host. The findings of this investigation helped clarify Wolbachia tropism in Trichogramma wasps.

Differential gene expression of Wnt signaling pathway in benign, premalignant, and malignant human breast epithelial cells.

To gain insight into the role of gene expression alterations in breast cancer progression, we conducted a comprehensive gene expression analysis of a series of cell lines derived from MCF10A, which include benign MCF10A cells, premalignant AT, and malignant CA1a tumor cells. We analyzed gene expression variation using the Agilent Human Genome Oligo Microarray with the goal of identifying gene-specific expression change events. In addition to a previously noted overexpression in oncogene MDM2, HRAS, and PCNA, our studies identified overexpression of Wnt signaling pathway in malignant breast cell lines. The Kaplan-Meier plot showed that high c-Myc expression in breast cancer was associated with tumor progression and the patient's poor survival. This study showed that the Wnt pathway has further provided a basis for the development of potential biomarker for breast cancer prognosis.

Efficacy and safety of percutaneous transforaminal endoscopic surgery (PTES) compared with MIS-TLIF for surgical treatment of lumbar degenerative disease in elderly patients: A retrospective cohort study.

Objectives: To evaluate the efficacy and safety of PTES for surgical treatment of lumbar degenerative disease (LDD) including lumbar disc herniation, lateral recess stenosis, intervertebral foraminal stenosis and central spinal canal stenosis in elderly patients compared with MIS-TLIF. Methods: From November 2016 to December 2018, 84 elderly patients (>70 years old) of single-level LDD with neurologic symptoms underwent the surgical treatment. 45 patients were treated using PTES under local anesthesia in group 1 and 39 patients treated using MIS-TLIF in group 2. Preoperative, postoperative back and leg pain were evaluated using Visual analog scale (VAS) and the results were determined with Oswestry disability index (ODI) at 2-year follow-up. All complications were recorded. Results: PTES group shows significantly less operation time (55.6 ± 9.7 min vs. 97.2 ± 14.3 min, P < 0.001), less blood loss [11(2-32) ml vs. 70(35-300) ml, P < 0.001], shorter incision length (8.4 ± 1.4 mm vs. 40.6 ± 2.7 mm, P < 0.001), less fluoroscopy frequency [5(5-10) times vs. 7(6-11) times, P < 0.001] and shorter hospital stay[3(2-4) days vs. 7(5-18) days, P < 0.001] than MIS-TLIF group does. Although there was no statistical difference of leg VAS scores between two groups, back VAS scores in PTES group were significantly lower than those in MIS-TLIF group during follow-ups after surgery (P < 0.001). ODI of PTES group was also significantly lower than that of MIS-TLIF group at 2-year follow-up (12.3 ± 3.6% vs. 15.7 ± 4.8%, P < 0.001). Conclusion: Both PTES and MIS-TLIF show favorable clinical outcomes for LDD in elderly patients. Compared with MIS-TLIF, PTES has the advantages including less damage of paraspinal muscle and bone, less blood loss, faster recovery, lower complication rate, which can be performed under local anesthesia.

Contralateral bridge fixation of freehand minimally invasive pedicle screws combined with unilateral MIS-TLIF vs. open TLIF in the treatment of multi-segmental lumbar degenerative diseases: A five years retrospective study and finite element analysis.

Objective: To evaluate the efficacy, safety, feasibility and biomechanical stability of contralateral bridge fixation of freehand minimally invasive pedicle screws (Freehand MIPS) combined with unilateral minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) (smile-face surgery) and open TLIF for the treatment of multi-segmental lumbar degenerative diseases (LDDs). Methods: From January 2013 to January 2016, clinical data of multi-segmental (2- or 3-level) LDDs receiving smile-face surgery or open TLIF were retrospectively collected and analyzed. The back and leg pain VAS and ODI were used to assess clinical outcomes preoperatively and postoperatively. The MacNab criteria were used to evaluate the satisfaction of patient. The disc height (DH), lumbar lordosis (LL) and segmental lordosis angle (SLA) were measured before and after surgery. We used patient's CT data to establish the finite element model of smile-face surgery and open TLIF, and analyze biomechanical stability of two methods. Results: Smile-face surgery group showed shorter operation time, shorter incision, less blood loss, shorter hospital stay than open TLIF (P < 0.05). The back VAS in smile-face surgery group was significantly lower than that in open TLIF immediately and 3 months after surgery, and no significant difference was observed 1 year, 2 years and 5 years after surgery. There was no significant difference in the leg pain VAS and ODI between both groups after surgery. No significant difference was observed between two groups in the DH, LL and SLA. At 5-year follow-up, grade I or II fusion was achieved in 99.00% (100/101) segments of smile-face surgery group and 97.67% (84/86) segments of open TLIF group according to Bridwell system. The complication rate of open TLIF was higher than that of smile-face surgery (24.32% vs. 0%, P < 0.01). After verification, the established finite element model can accurately simulate the biological structure of lumbar spine and there was no significant difference in biomechanical stability between two methods. Conclusions: Smile-face surgery has some advantages over open TLIF including smaller aggression, less blood loss, and lower cost, indicating that it is a good choice of treatment for multi-segmental LDDs. Both methods can achieve good biomechanical stability.

Percutaneous transforaminal endoscopic surgery combined with mini-incision OLIF and anterolateral screws rod fixation vs. MIS-TLIF for surgical treatment of single-level lumbar spondylolisthesis.

Objective: Oblique lumbar interbody fusion (OLIF) has been used to treat lumbar spine spondylolisthesis. However, it usually needs posterior pedicle screws fixation for biomechanical stability and possible posterior direct decompression for relieving neurologic symptoms. We use percutaneous transforaminal endoscopic surgery (PTES) combined with mini-incision OLIF and anterolateral screws rod fixation for surgical treatment of lumbar spondylolisthesis. The purpose of study is to evaluate the feasibility, efficacy, and safety of this method compared with minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF). Methods: From July 2016 to May 2018, 65 patients of lumbar spondylolisthesis (L2-4) with neurologic symptoms were treated using PTES combined with mini-incision OLIF and anterolateral screws rod fixation (31 cases, group A) or MIS-TLIF (34 cases, group B) in this study. Operative duration, blood loss, incision length, fluoroscopy frequency, and hospital stay are compared. Preoperative and postoperative visual analog scale (VAS) pain scores of back and legs, Oswestry disability index (ODI), intervertebral space height, lumbar lordotic angle, operative segmental lordotic angle, and complications are recorded. The fusion status is assessed according to Bridwell's fusion grades. Results: The VAS score of back and leg pain and ODI significantly dropped after surgery in both groups (p < 0.001). There was no statistical difference of back and leg VAS score and ODI between two groups except that back VAS scores in group A were significantly lower than that of group B immediately after surgery (p = 0.000). Group A had significantly more intervertebral space height and operative segmental lordotic angle than group B postoperatively (p = 0.022, p = 0.002). Twenty-three segments (74.2%) were grade I and 8 segments (25.8%) were grade II in group A; 20 segments (58.8%) were grade I and 14 segments (41.2%) were grade II in group B at a 2-year follow-up (p = 0.194). No difference was observed in the complication rate between the two groups (6.5% vs. 5.9%, p = 0.924). Conclusion: The long-term clinical efficacy and complication rates of both groups are comparable. PTES combined with mini-incision OLIF and anterolateral screws rod fixation is a good choice of minimally invasive surgery for lumbar spondylolisthesis, which hardly destroys the paraspinal muscles and bone structures.