The Application Research To Modify The Lateral Ventricular Puncture And The Related Technique Development

Purpose:External cerebrospinal fluid drainage is one of the most commonly used therapeutic techniques in neurosurgery.It specially indicates the technique to continuously drain cerebrospinal fluid out of the ventricle or lumbar cistern.Among them,external ventricle drainage?EVD?is more common.EVD is always administrated to alleviate the increased intracranial pressure when brain hernia happens,to clear the intraventricle hematoma and to treat the intracranial infections by draining the cerebrospinal fluid.It also provides the path for intraventrical medicine injection and to monitor the intracranial pressure.Thus,the EVD has multiple function including intracranial monitor,emergency management and treat various intracranial diseases.The frontal-horn of the lateral ventricle is the most common target for the EVD implementation.EVD targeting to the frontal horn of the lateral ventricle is one of the most common manipulations for neurosurgeons,which is a basic skill and should be well mastered^[1].Though the puncture point location and the operational method for EVD targeting the front horn of the lateral ventricle has been well known by most neurosurgeons,the failure of EVD implantation is not infrequent in clinical practice.The key reason for the failure of the EVD implantation is the failure to choose the best puncture direction.The radical reason of this fail chosen is the position location in the routine CT scanning does not correctly descript the plane of the frontal horn of the lateral ventricle.However,the most common reason is the lateral ventricle is compressed to move from its normal position or to be deformed.Therefore,in order to reduce the failure rate of EVD implantation,the objective of our study are:1.to accurately locate the frontal horn of the lateral ventricle and measure the required parameters for the by reconstructing the CT imagings of the head.=2.To design an assistant tool for lateral ventricle puncture according to the parameters.3.The efficacy of the new parameters and the assistant tool based lateral ventricle puncture is verified in the clinical trial of small patients sample.Method:?1?the out-patients who have normal brain CT scans were screened and their cranial CT images were collected.The three-dimensional reconstruction of the plane of the frontal horn of the lateral ventricle for ventricle puncture were reconstructed with computer.The plane constituted by the line of between two external auditory canal and the point of 2.0cm crossing the pre-coronary suture and the central line was also reconstructed.The relative parameters of the lateral ventricle puncture through the frontal horn based on these planes were recorded.?2?the imaging data of patients with ventricular hemorrhage and secondary hydrocephalus undergone the ventricle puncture through the frontal horn of the lateral ventricles were retrospectively collected.Then,the 3-dimentional puncture plane through the path of the frontal horn of the lateral ventricular was reconstructed.The stereotactic process of the ventricle puncture was simplified as implemented in two-dimensional plane.The standard puncture point was destined as the point of 2.5 cm away from the central line of this plane.The concept that the off-angle was proposed as the angle formed by the line connecting this standard puncture point and any point inside the frontal horn of the lateral ventricle and the reconstructed 2-dimentional sagittal plane through the midline.The parallel puncture was determined as the puncture direction was 0^o angle to the 2-D digital plane through the puncture point?i.e.0 angle?;The deviate puncture was determined as the puncture direction was at least more than 0^o angle?but less than the maximum off-angle?to the 2-D digital plane through the puncture point.The processes of both the parallel puncture and the deviate puncture was simulated in the computer and the successful puncture rate of was evaluated respectively;?3?A simple assistant tool for lateral ventricle puncture via the frontal horn was developed according to the parameters of lateral ventricle puncture and the above-mentioned simulated puncture process;?4?The lateral ventricle puncture via the frontal horn was prospectively performed in a small sample size patients with the assistant tool.The patients were sub-grouped into 2 groups with or without assistant tool.Before the puncture process,the plane of the lateral ventricle puncture through the frontal horn was reconstructed in the group with assistant tool.In this group,the puncture depth and the angle were both measured before puncture and the puncture was performed according to the measured puncture depth and angle wearing the puncture assistant tool.The other group only received general lateral ventricle puncture through the frontal horn without the assistant tool.The difference of successful puncture rates between these two groups patients was evaluated.Result:1.The lateral ventricular puncture plane through the frontal horn is successfully reconstructed based on the normal adult brain images,which is formed by the connecting line between bilateral external auditory canals and the point of2.0cm before coronal suture on the central line.The minimal and the maximal widths of the frontal horn of the lateral ventricles in this plane were 7 mm and 27 mm repectively,with an average of 15.68+3.66 mm and a 95%confidence interval of15.21¹6.15 mm.The width of the frontal horn of the lateral ventricle generally increases along with the age.There is a significant difference in the widths of the frontal horn of the lateral ventricles in patients with different ages?P<0.05?.2.The innovative concepts of off-angle and parallel puncture and deviate puncture are induced.The mean maximum and minimal off-angle are 17.67°+/-1.69°and6.07°+/-3.66°respectively,which could guarantee the successful lateral ventricle puncture through the frontal horn.There is no significant difference in the maximum off-angles of the different patients with differential ages.While,there is significant difference in the minimal off-angles of the different patients with differential ages?P>0.05?.Generally,the minimal off-angle decrease with the increasing age.3.The plane of the lateral ventricular puncture through the frontal horn is reconstructed in the retrospective collecting patients of ventricular hemorrhage and secondary hydrocephalus.The simulated puncture with deviate puncture is more effective than the parallel onewith statistical significance?P<0.05?.4.The patent of the assistant tool for lateral ventricule puncture via frontal horn has been approved by National Patent Bureau.5.When the lateral ventricular puncture is prospectively implemented with the help of the assistant tool,the successful and failure rate ofthe first puncture are 100%and 0%respectively.However,the successful and failure rate of the first puncture control group without assistant tool is 87.8%and 8.9%respectively.Both differences of the successful and failure rates between the experimental and control group are significant?P<0.05?.Conclusion:1.The relative parameters of the plane of the lateral ventricle puncture through the frontal horn are obtained in the normal adults.It reveals that the width of the frontal horn of the lateral ventricles in different normal adults varies along with the varied ages.It is preliminarily confirmed the correlation between the width of the frontal horn of the lateral ventricle and the patient's age.2.The notion of the off-angle and then the parallel puncture and deviate puncture are induced based on the off-angle.The advantage of the deviate puncture has been verified in the simulating puncture based on the retrospective data.3.A simple assistant tool is established based on the above research data and the patent has been approved by National Patent Bureau.This assistant tool has been preliminarily proved to increase the right puncture rate in a pilot clinical trial.