| Part one The Production of Intracerebral Hematoma ModelBackgroundIntracerebral hemorrhage(ICH)is the second most common(31.5%)and the first fatal(51.7%)stroke type in the world[1-3].The current surgery for intracerebral hematoma is mainly Craniotomy to remove hematoma,Minimally invasive puncture and suction bleeding,endoscopic removal of hematoma,extraventricular drainage(mainly for intraventricular hemorrhage)[4,5].Neuroendoscopic removal of hematoma in addition to its minimally invasive,can operate under direct vision,multiple viewing angles,clear hematoma thorough advantages,but also applies to the removal of both brain parenchymal and intraventricular hematoma,and can stop bleeding by electrocoagulation and laser.The neuroendoscopic learning curve is steep,It is particularly necessary to have a suitable hematoma model for hematoma removal training for doctors without endoscopic surgery experience.After consulting the literature,there is no report abroad about the Intracerebral Hematoma Model specially designed for intracerebral hematoma surgery.Chen Xiangrong and other domestic use of coconut shells,konjac flour production of intracerebral hematoma model[6],coconut shell instead of skull structure,agar clot as brain tissue,konjac gel as a hematoma,as a neuroendoscopic training model.But there is no skull structure mark on the skull model,so it can not simulate the positioning and drilling steps,konjac gel also has some differences with the real hematoma.It is still necessary to make further studies to create a model that simulates intracerebral hematoma removal as completely as possible.PurposeTo develop an intracerebral hematoma model suitable for use as a teaching training for intracerebral hematoma removal.The establishment of an intracerebral hematoma model can help the neurosurgeons who have no experience in endoscopic surgery to get the surgical methods and techniques of endoscopic intracerebral hematoma removal,and can provide the conditions for the development of endoscopic intracerebral hematoma removal in primary hospitals.Extending its scope of application,it can also provide a realistic and practical model for intracerebral hematoma removal surgery such as craniotomy hematoma removal and puncture hematoma cavity drainage.Research methods1.Intracerebral hematoma model making1.1 Materials:3D printer,SLA photosensitive resin,agar powder,corn starch,oil paper,fresh pig blood,clear water,magnetic stirrer,beaker,glass rod,pressure cooker and so on.1.2 Production Methods:The skull model was designed by the Blender modeling software.After the modeling was completed,a light-curing 3D printer with photosensitive resin was used to print the simulated skull model.Apply oiled paper to the pre-surgical area on the skull’s inner surface to simulate the dura mater.The agar powder and the corn starch were evenly mixed in a certain proportion and added into the boiled clear water and mixed into a skull model.After cooling,a mixed agar block was formed to simulate the brain tissue.Blood clots formed by fresh porcine blood are embedded in agar blocks at specific locations to simulate intracerebral hematoma.2 Experimental application of intracerebral hematoma modelFour neurosurgeons in Nanfang Hospital with extensive experience in neuroendoscopy act as instructors trained twenty training doctors who had no experience in endoscopic surgery for endoscopic intracerebral hematoma evacuation.Assessment of the student’s operation and scores.At the end of the training,analyze the training of the students from the three quantitative indicators of hematoma clearance rate,surgical operation,and hematoma clearance rate.Questionnaires on satisfaction with the use of the model by trainees were conducted.Based on the training results of the trainees and the results of the questionnaires,The practicality and simulation of the model of the training model were evaluated.Results1 The hematoma cavity intracerebral hematoma model is realistic and close to the actual intraoperative image.The appearance of the skull is almost the same as the real skull.2 Agar powder,corn starch and the agar block made of water at a ratio of 20:1:400 is close to the brain tissue,and can be passed through by a endoscopic sheath.The feel during the puncture process,the image effect is basically the same as the actual intraoperative puncture.3 At the end of the training,the trainees basically grasped the endoscopic hematoma removal operation.The results of the questionnaire showed that trainees were satisfied with the intracerebral hematoma model.Conclusion1 The intracerebral hematoma model produced has a strong simulation,and it is suitable for endoscopic intracerebral hematoma removal surgery training.To promote its scope of use,it can also be used as a training model for hematoma removal under a craniotomy,aspiration puncture,and even as a experiment using model.2 After the endoscopic hematoma removal training course,trainees were familiared with the surgical procedure,the endoscopic surgical techniques were improved,successfully complete the transition from laboratory surgery to actual surgery learning.Part Two:The Experimental Research of Positive Pressure Ventilation in Endoscopic Intracerebral Hematoma RemovalBackgroundThe surgery of neuroendoscopic removal of intracerebral hematoma can be divided into extral-axial endoscopic neurosurgery,also known as XEN,the inrtral-axial endoscopic neurosurgery,also known as IEN.Extral-axial endoscopic removal of intracerebral hematomas uses retractors,sleeves or even film to retract open brain tissue into surgical channels[7,8].Endoscopy is the only light source and imaging system.Microsurgical instruments can be used to remove hematomas.As for inrtral-axial endoscopic intracerebral hematoma removal,endoscopic puncture hematoma cavity with the transparent endoscopic sheath[9],endoscopic equipment remove the hematoma through the endoscopic working channel,then the brain tissue injury and pulling are less traumatic than XEN,and the degree of traction in brain tissue is lower.It is more in line with the minimally invasive concept.During endoscopic surgery,the image of the hematoma cavity is clearer in the air than in the water environment,and continuous irrigation is not required.The clear vision[10]can greatly shorten the operation time.Absorption of air in the air environment is always difficult to avoid,and endoscopic working channel is slender,in addition to the device’s entrance,improper suction method may cause negative pressure in the hematoma cavity due to empty suction.This will cause a pressure gradient in the intracranial pressure,which may lead to a subdural hematoma due to severe bridge vein rupture.On the other hand,when the air environment attracts a hematoma,the lens is easily contaminated by a hematoma.Whether the endoscope is pulled out of the sheath or the lens is dripped to clean the lens,it can affect the surgical procedure.It is the above two reasons for endoscopic surgery.In addition,extral-axial endoscopic intracerebral hematoma removal is closer to microsurgery.Neurosurgeons have to sacrifice minimally invasive surgery and chose the XEN.In order to reduce the lens contamination and increase the safety of intra-axial endoscopic intracerebral hematoma removal surgery in the air environment,This study attempted to use a pneumoperitoneum machine as a ventilation device and medical carbon dioxide as a gas source for positive pressure ventilation in hematoma.and to verify the positive pressure ventilation in the experiment can reduce endoscopic lens contamination and reduce the negative pressure in the hematoma cavity.To investigate the relationship between positive pressure ventilation and surgical operation of hematoma cavity,how to achieve less surgical injury than endoscopic surgery can safely and quickly complete the operation.Due to the special nature of craniocerebral surgery,intrahepatic ventilation of the hematoma needs to ensure gas sterility and avoid gas-borne intracranial infection.This study sterilizes the gas pathways associated with the abdomen and airways,and conducts bacterial cultures on the gas blown out of the ventilator pathway to detect gas safety during positive pressure ventilation using an aerator device.PurposeThe aim of this study was to investigate the effect of positive pressure ventilation in hematoma in reducing lens contamination and reducing the negative pressure in the hematoma cavity during endoscopic debridement.When the number of lens contaminations is reduced,the ineffective surgical movement of the endoscope to and from the sheath and the shift of the endoscope sheath to cause the traction of the brain tissue are reduced,and the negative pressure in the hematoma cavity is reduced,thereby reducing the intracranial pressure gradient during the suction.The resulting adverse consequences.If positive pressure ventilation can achieve this goal,the development of new endoscopic instruments will provide new ideas for endoscopic hematoma removal and other endoscopic surgical methods.Methods1 Positive pressure ventilation in hematoma removal related tests1.1 T A 250 ml bottle with a rubber stopper with a mixture of 200 ml of pig blood and blood clot was taken.The disposable abdominal penetrator penetrated the rubber stopper and the body of the puncture needle was removed,and the head was retained to simulate the closed hematoma cavity.The U-shaped pressure tube measures the pressure inside the bottle through the vent of the trocar.The large-channel neuroendoscope and the transparent catheter sheath are inserted into the glass via a disposable abdominal trocar.Connect the outlet end of the abdomen machine with the side channel of the large tunnel neuroendoscope and set the parameters of the abdomen machine(pressure 15mmHg,gas flow 10L/min).Connect the vacuum suction and set the attraction size to-200mmHg.In the way of blocking the hole on the side of the aspirator,set the intermittent suction frequency(the same time as the blocking time and the release time).1.2 Suction was continued and the glass bottle was air-sucked for 1 minute in a manner of continuous attraction and the highest negative pressure in the glass bottles was measured in both inflated and non-inflated manners,and each group was measured 20 times.1.3 Under positive pressure ventilation,intermittent vacuum is applied to glass bottles at 30,60,90,120,and 150 different frequency intervals to measure the maximum negative pressure in the glass.1.4 Set the intermittent attraction frequency of 120 times/min.In the positive pressure ventilation and non-ventilation methods,the blood clot in the glass bottle was sucked,and the number of lens contamination within 1.0 minute was measured when the distance between the lens and the mirror tip was 1.0 cm,1.5 cm,2.0 cm,and 2.5 cm.2 Gas safety test2.1 Gas Pathway SterilizationThe autoclave high-pressure hose is sterilized by high pressure steam sterilization.Prepare chlorine dioxide gas to sterilize internal tubes of a ventilator.The carbon dioxide gas cylinder and the air interface of the air-belly engine were wiped with Anerithine Iodine,and the inflator and cylinder were connected.2.2 Take 20 MH agar medium,open the sterilized insufflator,and let the carbon dioxide gas blow at the center of the culture medium.Each medium is blown for 5 minutes.The inflated culture medium was placed in a constant-temperature bacterial incubator at 37℃.After 48 hours of culture,whether or not colonies were generated was counted.2.3 Randomly take the same type of air belly machine that does not sterilize the internal tubes and high-pressure hoses of the abdomen machine,and connect the gas cylinders.According to step 2.2,compare and analyze the generation of colonies in the disinfected and unsterilized groups.2.4 The cylinder valve in step 2 is closed,the air belly machine is started to drain the net gas,and the high pressure hose and the disposable filter are disassembled.The medical sterile transparent dressing closes the air supply port and the air injection port of the air belly machine.After January,replace the gas cylinders,sterilize the high-pressure hoses in the same way,sterilize the interface,connect the gas cylinders and the air belly machine,and in the same way test the gas blown by the gas belly.If the culture medium does not have bacterial growth,repeat the above operation after the 2nd and 3rd months to verify the safety of the gas cylinder after the air sterilization in the internal cylinder after sterilization.The control group was not sterilized.Results1 Under the condition of continuous attraction and intermittent attraction,the negative pressure in the glass bottle of the inflatable group was significantly smaller than that of the non-inflated group,P<0.05,which was statistically significant.Under negative pressure ventilation and non-ventilation,the negative pressure in the intermittent hematoma cavity was significantly smaller than that in the continuous suction group,P<0.05,which was statistically significant.Therefore,in order to ensure that the negative pressure in the hematoma cavity is as small as possible during hematoma removal,continuous positive pressure ventilation and intermittent suction should be selected.2 With the increase of the blocking hole frequency,the maximum negative pressure in the hematoma cavity tends to decrease.When the blocking hole frequency is 120 times/minute,the maximum negative pressure decreases.The higher the blocking frequency,the lower the hematoma removal efficiency,so the blocking frequency should be 120 times per minute.3 The frequency of lens contamination when the lens end was at a different distance from the tip of the mirror sheath when the hematoma was intermittently aspirated at a frequency of 120 beats per minute in positive pressure ventilation and non-ventilation.Using variance analysis of repeated measurement data,positive pressure ventilation in hematoma can significantly reduce the number of lens contamination per unit time,F=23.228,P=0.000,statistically significant.Hematoma distance was 1.0cm and 1.5cm,and the number of lens contamination in the positive pressure ventilation group was significantly smaller than that in the non-ventilation group(P=0.000).The distance from the hematoma was 2.0 cm and 2.5 cm,and there was no significant difference between the positive pressure ventilation group and the non-ventilation group(P>0.05).On the other hand,the farther the lens is from the tip of the mirror sheath,the narrower the field of view through the catheter sheath is.This indicates that in the positive pressure ventilation intracerebral hematoma removal,a suction distance of 1.5 cm is required to reduce the number of lens contamination.4 Gaseous Bacterial Culture Results of Gas Pipe Sterilization Group and Gas Pipe Sterilization Group:Repeated Measurement Data Analysis of Variance Analysis:F=431.78,P=0.000,statistically significant,indicating gas pipeline After sterilization,the gas content of air blown by the inflator was significantly lower than that in the non-sterilized group.Conelusion1 The Positive pressure ventilation can reduce the probability of lens contamination in simulated intracerebral hematoma removal surgery.2 The ventilation pressure not exceeding the safe range is set.In the case of air suction,positive pressure ventilation can significantly reduce the negative pressure in the hematoma cavity.3 The Positive pressure ventilation was used to remove hematoma in the brain.The effective surgical matching method was to set the distance between the inner lens end and the sheath tip to 1.5 cm and the hematoma attraction method to 120 beats per minute.4 Sterilization treatment of the relevant gas pipelines of the abdomen machine can effectively reduce the bacteria content in the gas. |
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