Using Piezosurgery in Anterior Cervical Discectomy and Fusion to Treat Complex Cervical Spondylotic Myelopathy Is Safe and Effective.

Objective: To investigate the safety and efficacy of piezosurgery in anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). Methods: 47 patients with complex CSM (cCSM) underwent ACDF surgery from 2014 to 2017. Among these patients, 26 underwent ACDF using piezosurgery (group A) and 21 underwent ACDF by using traditional tools such as high-speed air drill, bone curette, and Kerrison bone punch (group B). Average surgical time, intraoperative blood loss, surgical complications, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, and improvement rate were measured. Results: Average surgical time and intraoperative blood loss were significantly lower in group A than those in group B (P < 0.01). The incidences of surgical complications were 3.8% and 23.8% in the A and B groups (P < 0.05), respectively. There were no significant differences in JOA scores and improvement rates between data collection periods at preoperative, 3-day postoperative, and 1-year postoperative follow-ups (P > 0.05). Conclusion: For treating cCSM, both the piezosurgery and traditional tools led to significant neurological improvement. However, the piezosurgery was superior to the traditional tools in terms of surgical time, blood loss, and complication rate. Hence, piezosurgery was a safe and effective adjunct for ACDF treating cCSM.

Hyperosmolarity disrupts tight junction via TNF-α/MMP pathway in primary human corneal epithelial cells.

AIM: To investigate the mechanism of the tight junction (TJ) disruption and the association between tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMPs) under hyperosmotic condition in primary human corneal epithelial cells (HCECs). METHODS: The cultured HCECs were exposed to media which adding sodium chloride (NaCl) for hyperosmolar stress or adding rh-TNF-α (10 ng/mL). NF-κB inhibitor (5 µmol/L) or GM-6001 (potent and broad spectrum MMP inhibitor, 20 µmol/L) was added 1h before that treatment. The integrity of TJ proteins was determined by immunofluorescent (IF) staining. The mRNA levels of TNF-α and MMPs were evaluated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and the protein expression by enzyme-linked immunosorbent assay (ELISA). RESULTS: TJ proteins ZO-1 and Occludin were disrupted in primary HCECs exposed to hyperosmotic medium. The mRNA expression and protein production of TNF-α increased significantly in hyperosmotic media at 500 mOsM. TNF-α mediated the expression and production of MMP-1, MMP-13, MMP-9, and MMP-3 stimulated by hyperosmotic stress. The production of MMPs in hyperosmolar media were increased through the increase of TNF-α. GM-6001 prevent the destruction of ZO-1 and Occludin in hyperosmolar stress and rh-TNF-α treated medium. TNF-α induced activation of MMPs was involved in the TJ disruption by hyperosmolarity. CONCLUSION: TJ proteins ZO-1 and Occludin are disrupted by hyperosmolar stress and TNF-α, but protected by MMP inhibitor (GM-6001). It suggests that TNF-α/MMP pathway mediates the TJ disruption in primary HCECs exposed to hyperosmotic stress.

Comprehensive evaluation of intravitreal conbercept versus half-dose photodynamic therapy for chronic central serous chorioretinopathy.

AIM: To compare the safety and efficacy of conbercept intravitreal injection and half-dose photodynamic therapy (PDT) in treating chronic central serous chorioretinopathy (CSC). METHODS: This study was retrospective. Thirty-seven patients (37 eyes) with chronic CSC received conbercept injections while 57 patients (57 eyes) were treated with half-dose PDT. All subjects were followed in 6mo. Outcome measures included change in best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and resolution of subretinal fluid (SRF). RESULTS: There was no adverse event observed in either treatment group. At the 6-month follow-up, 26 eyes (70.3%) in the conbercept group and 54 eyes (94.7%) in the half-dose PDT group (P<0.05) reached full resolution of SRF. The mean logarithm of the minimum angle of resolution (logMAR) BCVA significantly improved (P<0.001) in both treatment groups with better outcome at early phase in the half-dose PDT group (2wk, 1, and 2mo, P<0.05). All subjects experienced significant CMT improvement (P<0.001) with no statistical difference between the two groups (P>0.05). The SFCT also improved in all subjects (P<0.001) with better outcome in the half-dose PDT group (P<0.05). CONCLUSION: Both intravitreal conbercept and half-dose PDT are safe to use in treating chronic CSC. By 6mo, both treatment groups are efficacious in improving BCVA, reducing CMT and SFCT, and resolving SRF in eyes with chronic CSC. Half-dose PDT may show better outcome at initial phase of treatment in chronic CSC. Longer follow-up period is necessary to study for long-term effect and safety.

Effect of intravitreal conbercept treatment before vitrectomy in proliferative diabetic retinopathy.

AIM: To evaluate the safety and efficacy of intravitreal conbercept (IVC) injections as pretreatment for pars plana vitrectomy (PPV) in severe proliferative diabetic retinopathy (PDR). METHODS: This was a retrospective chart review of all patients who underwent PPV for PDR from January 2014 to October 2016. Patients who underwent IVC injection before PPV were assigned to the IVC group; the others were assigned to the control group. The IVC was performed 3-7d before surgery in the IVC group. All the eyes in the two groups were operated by the same doctor to complete the vitrectomy. Intraoperative complications and the changes in best-corrected visual acuity (BCVA) before and after surgery were compared between the two groups. RESULTS: A total of 68 eyes of 63 patients (22 eyes in the IVC group and 46 eyes in the control group) were examined. The risk of intraoperative bleeding was lower in the IVC group (2/22) than in the control group (25/46, P=0.000). Furthermore, the use of endodiathermy was significantly lower in the IVC group (1/22) than in the control group (12/46, P=0.047). The surgical time in the IVC group (112.64±34.52min) was significantly shorter than in the control group (132.85±40.04min, P<0.05). Compared to the BCVA before surgery, the mean BCVA was significantly improved after surgery for both groups (P<0.05). CONCLUSION: PPV is an effective treatment and can improve vision in patients with PDR. Preoperative intravitreal injection of conbercept could reduce the chances of intraoperative bleeding and the use of endodiathermy and shorten the operative time, which are beneficial in the management of PDR.

Cooperative robot assistant for vitreoretinal microsurgery: development of the RVRMS and feasibility studies in an animal model.

PURPOSE: The purpose of the study was to describe the development of a robotic aided surgical system named RVRMS (robotic vitreous retinal microsurgery system) and to evaluate the capability for using it to perform vitreoretinal surgery. METHODS: The RVRMS was designed and built to include the key components of two independent arms. End-effectors of each arm fix various surgical instruments and perform intraocular manipulation. To evaluate properly the RVRMS, robot-assisted 23-gauge surgical tasks including endolaser for retinal photocoagulation, pars plana vitrectomy (PPV), retinal foreign body removal and retinal vascular cannulation were performed in two different sizes of an animal model. Endolaser was performed in the eye of a living Irish rabbit and the other tasks were done in a harvested porcine eye. For each evaluation, the duration and the successful completion of the task was assessed. RESULTS: Robot-assisted vitreoretinal operations were successfully performed in nine rabbit eyes and 25 porcine eyes without any iatrogenic complication such as retinal tear or retinal detachment. In the task of using an endolaser, three rows of burns around the induced retinal hole were performed in nine rabbit eyes with half size intervals of laser spots. Nine procine eyes underwent PPV followed by successful posterior vitreous detachment (PVD) induction assisted with triamcinolone acetonide (TA). Nine porcine eyes completed removal of a fine stainless steel wire, which was inserted into prepared retinal tissue. Finally, retinal vascular cannulation with a piece of stainless steel wire (6mm length, 45 µm pipe diameter and one end cut to ∼30° slope) was successfully achieved in seven porcine eyes. The average duration of each procedure was 10.91±1.22 min, 11.68±2.11min, 5.90±0.46 min and 13.5±6.2 min, respectively. CONCLUSIONS: Maneuverability, accuracy and stability of robot-assisted vitreoretinal microsurgery using the RVRMS were demonstrated in this study. Wider application research of robotic surgery and improvement of a robotic system should be continued.