From January 1998 to June 2002, 142 patients with hydrocephalus underwent ventriculo-abdominal shunts in our hospital. During the operation, the placement and method of the ventricular and ventral ends of the shunt were improved respectively, which improved the efficacy and shortened the operation time, and reduced the chance of various complications with satisfactory results. Data and methods I. General data There were 88 male cases and 54 female cases. The ages were 4 years-66 years. There were 76 cases of obstructive hydrocephalus and 78 cases of transmissible hydrocephalus. All patients with hydrocephalus were confirmed by CT or MRI films. The catheters used for ventriculo-peritoneal shunts were all American PS-Medical type catheters. Before surgery, lumbar puncture was performed to measure the cerebral pressure and according to the results, high-pressure, medium-pressure and low-pressure shunt catheters were selected. The ventricular end placement method: Before surgery, the level of the interventricular foramen of the lateral ventricle was selected in the axial cranial CT film, and a straight line parallel to the body of the lateral ventricle was made at this level from the side of the interventricular foramen in the direction of the occipital angle of the lateral ventricle and extended to the occipital bone. Three points on this line are chosen and marked as A, B and C. Point A is located in the lateral ventricle near the interventricular foramen, point B is at the far point of the occipital angle of the lateral ventricle, and point C is where the extension of the line connecting the two points AB intersects the occipital skull. The direction and length of points A and C were measured before surgery, and the direction was used as the placement direction of the ventricular end of the catheter during surgery, point A as the placement position of the end of the shunt, point C as the location of the hole in the skull, and the distance between points A and C as the placement depth of the ventricular end of the shunt. Placement method of ventricular end: after ultrasound examination before surgery to exclude hepatomegaly or other abdominal diseases affecting the surgical factors, a 1 cm long linear incision was made 4 cm below the median glabella in the abdomen, the anterior sheath of the rectus abdominis muscle was cut, and then the peritoneal cavity was punctured with a 3 mm diameter, 8 cm long casing with a C-shaped homemade metal trocar needle, the tip of the needle was pierced into the peritoneum and the inner trocar core was removed, and then the ventral end of the shunt was placed into the peritoneal cavity, the specific ventral position The specific abdominal location is not required, and the length is about 20-40 cm, and then the C-shaped jacket tube is pulled out. If it was difficult or inaccurate to puncture the peritoneal cavity, the cerebral angiography puncture needle was used to puncture the peritoneal cavity instead, and a C-shaped peritoneal puncture needle was introduced followed by the placement of a shunt at the peritoneal end. Results Postoperative follow-up ranged from 6 months to 48 months, and follow-up results were obtained in 124 cases. The CT scan confirmed that the direction of the ventricular end shunt was parallel to the direction of the body of the lateral ventricle, and the tip was located at the location of the interventricular foramen of the lateral ventricle, and the hydrocephalus was reduced or disappeared in 102 cases. In this group, 22 patients with hydrocephalus developed complications after surgery, including 13 cases of blockage of the ventricular end or ventral end of the shunt; 6 cases of fever caused by postoperative infection; 2 cases of small amount of bleeding in the brain tissue or intracerebral ventricles in the surgical area; and 1 case of acute epidural hematoma on the day after surgery due to excessive collapse of the brain tissue after the release of cerebrospinal fluid from the punctured ventricle during surgery. All of the above patients improved after adjustment of the ventricular end or ventral end shunts, removal of hematoma or symptomatic treatment. No complications such as intracranial pneumoperitoneum, intestinal perforation, or cerebrospinal fluid leakage occurred. Discussion Since the first ventriculo-abdominal shunt was performed by Kausch in 1905, surgical methods and catheter materials have been continuously improved and developed, making this procedure increasingly used in patients with various types of hydrocephalus [1,3,4]. Although this procedure is simple to perform, there are still some problems such as blockage of the shunt at the ventricular or ventral end, postoperative infection or the ventral end of the shunt to the outside of the body via various internal cavities, and people have been choosing an optimal procedure to solve the emergence of the above complications. The common causes of blockage of the ventricular end of the shunt after ventriculo-abdominal shunt are: blockage by brain tissue debris or blood clots during puncture, excessive protein content in the cerebrospinal fluid, inadvertent entry of brain tissue during puncture or encapsulation by the choroid plexus in the lateral ventricle, which are mostly caused by repeated puncture of brain tissue or vascular injury or improper placement of the ventricular end of the shunt [1,4]. In the past, when the lateral ventricular triangle was punctured by the temporal angle, the puncture direction and depth were not easy to grasp, and the shunt tube was placed at a certain angle with the body of the lateral ventricle, so that it was easy to accidentally penetrate into the contralateral brain tissue or be blocked by the abundant choroid plexus tissue in the lateral ventricular triangle, or the end of the shunt tube was accidentally inserted into the ipsilateral or contralateral brain tissue due to the small size of the ventricular cavity after shunt surgery. Blockage of the ventricular end of the shunt due to these causes has been reported in the literature in 14%-58% of cases [2]. The interventricular foramen is relatively unchanged after the presence of hydrocephalus and the disappearance of hydrocephalus after shunt surgery, and it is the intersection of the left and right ventricles with relatively little choroid plexus tissue, so it can be the best location for placement of the ventricular end of the shunt. The direction and length of the occipital puncture point and the interventricular foramen of the lateral ventricle were measured separately for each patient before surgery, and were used as the puncture direction and placement depth for the ventricular end catheter placement, thus avoiding repeated punctures that could cause cerebral hemorrhage and shunt blockage caused by brain tissue fragments carried into the lateral ventricle. It should be noted that too much cerebrospinal fluid should not be released after successful puncture of the ventricular end to avoid postoperative hypocranial pressure headache, intracranial pneumatization or epidural or subdural hematoma due to sudden decrease in cerebral pressure or collapsed brain tissue vascular dissection [3,4]. Subcutaneous tunneling along the temporal area to drain the ventricular end of the shunt to the ventral cavity after puncture through the frontal horn has been reported. The author believes that this method has disadvantages because the placement of the drainage tube in the temporal region affects the aesthetics, and the placement of the shunt under the skin of the zygomatic arch and face can cause discomfort to the patient, especially when the chewing temporalis muscle is in motion. There has been controversy regarding the incision of the abdominal cavity and the length of the abdominal tube placed in the abdominal cavity during the placement of the abdominal end of the shunt, and some complications have gradually decreased or disappeared with advances in catheter fabrication materials. Also, the literature reports that shunt placement anywhere in the abdominal cavity has the potential for blockage of the abdominal end or other complications [1,2,4,5]. The adopted method of trocar needle puncture of the abdominal cavity is suitable for placement in all parts of the abdominal cavity and has the advantages of greatly reducing the operative time, reducing contamination, avoiding incisional hernia and intestinal adhesions, and small abdominal incisional scar compared with the traditional incisional placement method. In the use of shunts, cerebral pressure is measured before surgery, and the selection of shunt catheters with different pressures according to the results of pressure measurement can avoid excessive shunts or insufficient shunts causing poor efficacy.