[Abstract] Objective To prospectively investigate the dynamic changes of the position of the ventral end of the shunt after ventriculo-peritoneal (V-P) shunt and to determine a simple and effective disposal method for the ventral end. Methods Forty consecutive patients with hydrocephalus were treated by V-P shunt between January 2007 and October 2010. The ventricular end was punctured by frontal horn puncture, and the ventral end was placed into the abdominal cavity by a 4-cm median incision below the glabella. The cranial CT was routinely reviewed on postoperative days 1, 3 and 7 to determine the intracranial status, and abdominal plain films were also taken to determine the location of the shunt at the ventral end. The clinical data and follow-up results of these 40 patients were retrospectively summarized. Results In this group, there were 27 males and 13 females with a mean age of 55±17 years; causes of hydrocephalus: craniocerebral trauma in 15 cases, spontaneous intracerebral hemorrhage in 7 cases, ruptured bleeding aneurysm in 6 cases, brain tumor in 5 cases, idiopathic in 4 cases, dural arteriovenous fistula in 2 cases and meningitis in 1 case. Dynamic cranial CT examination showed that all 40 cases had good shunting effect. The abdominal plain film showed that the abdominal end of the shunt was located in the pelvis in 31 cases and the lower abdominal cavity in 5 cases on postoperative day 1; the abdominal end of the shunt was located in the pelvis in 35 and 39 cases on postoperative day 3 and 7, respectively. One case in this group developed a contralateral acute subdural hematoma 5 days after surgery, and the family gave up the operation and was discharged automatically; the rest of the patients were discharged on average 11±4 days after surgery. one case developed an infection at the ventral end 1 year after surgery, and the infection was controlled and converted to a ventriculo-atrial (V-A) shunt; the rest of the patients were followed up 1 month to 2 years after surgery without shunt-related complications. Conclusion The use of a small incision in the posterior subxiphoid process can reduce the surgical trauma and shorten the operative time and obtain a good shunt effect. Keywords] Hydrocephalus; V-P shunt; abdominal plain film Hydrocephalus is one of the common neurosurgical disorders, and Ventriculo-peritoneal shunt (V-P shunt) is the most commonly used surgical method in clinical practice for patients with obvious symptoms. This method is simple and effective, but the complications of blind placement, shunt obstruction, infection, and abdominal and pelvic perforation caused by the abdominal end of the shunt affect the surgical efficacy of this procedure. In order to ensure the absorption effect after V-P shunt surgery and reduce the incidence of large omental wrapping, abdominal pseudocysts, intestinal adhesions, and intestinal obstruction, scholars have used diverse disposal methods of shunts at the abdominal end, including different disposal methods of abdominal incision, liver compartment fixation, small peritoneal cavity placement, pelvic built-in tube, and laparoscopic assistance. In order to explore simple and effective methods of disposal of abdominal end shunts in V-P shunts, we have prospectively observed the position of the end of abdominal end shunts in the abdominal cavity after V-P shunts using regular observation by abdominal X-ray plain film for the last 3 years and followed up the postoperative outcome, and the results are reported below. Data and methods 1. General data: 27 male and 13 female cases in this group, aged 21-83 years (mean age 55±17 years); causes of hydrocephalus: 15 cases of craniocerebral trauma, 7 cases of spontaneous intracerebral hemorrhage, 6 cases of ruptured bleeding aneurysm, 5 cases of brain tumor (2 cases of astrocytoma, 2 cases of giant pituitary tumor, 1 case of intracerebroventricular ganglion cell tumor), 4 cases of senility, 2 cases of dural arteriovenous fistula 1 case of meningitis; duration of disease: 14 days to 3 years, average 86±133 days; 2. Clinical manifestations: 15 cases of craniocerebral trauma, all with craniocerebral hemorrhage or brain swelling, treated by unilateral large bone flap decompression, postoperative follow-up revealed progressive enlargement of the ventricular system, accompanied by gradual outward expansion of the decompression window; 7 cases of spontaneous intracerebral hemorrhage, with gradual outward expansion of the decompression window after hematoma removal + debridement decompression In two cases (one treated with embolization and one with intracerebral hematoma removal and arteriovenous fistula excision), there was a postoperative improvement in consciousness followed by deterioration; and in one case of encephalitis, there was drowsiness and vomiting. Preoperative Glasgow Coma Scale (GCS): 6 cases with ≤8 points, 24 cases with 9-12 points, and 10 cases with 13-15 points, with an average of 11±3 points; 3. Preoperative imaging: The group was examined by cranial CT scan before surgery, and all of them showed enlarged ventricles accompanied by periventricular hypodense exudates. In 4 cases of idiopathic hydrocephalus, preoperative routine cranial MRI examination showed periventricular high signal shadow on T2 image except for ventricular enlargement. In the four cases with surgical clamping of aneurysm, whole brain DSA was performed before shunt surgery, which showed complete clamping of aneurysm. 4. Among those with non-normal cranial pressure hydrocephalus, 5 cases chose the aforementioned adjustable pressure shunt, setting the pressure at 110-130 H2O, and the rest chose the medium pressure shunt. The choice of the shunt was made by the family according to the patient’s financial situation; 5. Surgical method: In this group, general anesthesia was used, and a straight incision (2 cm and 4-5 cm long) was made at the puncture site of the frontal horn of the lateral ventricle in the head and a median incision (about 4 cm long) 3 cm below the glabella in the abdomen. After routine disinfection of the operative field, two groups of three people in the head and abdomen were operated simultaneously. After the head borehole was successfully punctured through the ventricle, the ventricular end of the tube was placed at a depth of 5-5,5 cm (calculated on the surface of the cortex), and after connecting the fixed shunt pump and the ventral end of the shunt introduced through the subcutaneous tunnel, the skull borehole was closed with gelatin sponge and otocerebral glue, and the scalp was closed in two layers. After the abdominal operation, the skin was cut to separate the subcutaneous tissue, the anterior sheath in the incision was exposed, the abdominal white line was cut about 1 cm in the middle of the field, the extraperitoneal fat was shunted and the peritoneum was lifted and drawn out, the peritoneum was cut about 2 mm, the ventral end of the shunt, which was wiped clean and confirmed to have automatic flow of cerebrospinal fluid, was placed into the abdominal cavity, and the peritoneum, abdominal white line, subcutaneous layer and skin were closed in layers. In this group, 5 cases of debridement and decompression were repaired and reshaped by cranioplasty on the opposite side at the same time after shunt surgery; 6. class is above the flat umbilical plane, class II is between the umbilical plane and the plane of the anterior superior iliac crest, and class III is below the plane of the anterior inferior iliac crest. If the plain film on the first postoperative day showed that the position of the shunt was class III, it was not reexamined; if it was class I and II, the plain film was reexamined on the third day; if it still did not reach class III, the plain film was reexamined on the seventh day. Within 1 to 7 days after surgery, 6 routine abdominal CT thin layer scans followed by 3D imaging showed good position of the abdominal end of the shunt; 7. Main postoperative treatment: hemostatic drugs were given on the same day after surgery, dehydration drugs were stopped, and conventional comprehensive treatment was given according to the individualization of the patients. In this group, metronidazole was routinely given for 5 days after surgery (100ml/time, 2 times/day) Results 1. Neurological function recovery: In this group In one case of craniocerebral trauma with debridement and decompression, the consciousness turned clear after V-P shunt, and the cranial CT scans of 1 and 3 days after surgery showed improvement of hydrocephalus and no intracranial hemorrhage, but on the 5th day after dinner, there was a sudden coma with dilated pupils on the shunt side, and the emergency cranial CT scan showed a huge subdural hematoma with equal high mixed density on the shunt side, and the family gave up treatment and was discharged automatically. In the rest of the patients, the condition was stable and improving after surgery, and the decompression window external expansion began to relieve in 1 to 3 days after surgery, and the conscious state of those with impaired consciousness gradually improved. In the 5 cases with cranial repair at the same period, no bleeding or fluid accumulation was seen on the repair side. 3. The results of determining the location of the ventral end of the shunt: 77,5% of the shunts had entered the pelvic cavity on the first postoperative day, and 97,5% of the shunts entered the pelvic cavity on the seventh postoperative day. During the postoperative period from 3 months to 1 year, 5 cases were followed up by re-taking the abdomen, and the location of the abdominal end of the shunt was class III (intrapelvic). 4. Status of patients at discharge and follow-up results: The group was discharged home or transferred to rehabilitation treatment on average 11±4 days after surgery; GCS at discharge: ≤8 points in 1 case, 9-12 points in 4 cases, 13-15 points in 35 cases, average 13±2 points. Outpatient follow-up was used, and the follow-up period was 1 month to 2 years (mean 8±4 months). In 2 cases of cerebral astrocytoma, the tumors recurred 1 and 2 years after surgery and died of cerebral failure; in 1 of the 2 cases of giant pituitary tumors, systemic failure due to hypopituitarism died 6 months after surgery; in 1 patient in this group, intermittent fever was observed 1 year after surgery, and lumbar puncture confirmed elevated leukocytes in the CFS before surgical removal of the shunt, which was confirmed intraoperatively to be an infection at the ventral end, and was switched to a V-A shunt after inflammation control. For those who did not undergo simultaneous cranial repair, 10 cases were readmitted for cranial repair 1 to 3 months after shunt surgery. No shunt-related complications occurred in the rest of the patients, except for one case of infection and one case of subdural hematoma 5 days after surgery, as described above. Discussion Hydrocephalus is the accumulation of cerebrospinal fluid in the ventricular system and subarachnoid space due to obstruction of cerebrospinal fluid circulation pathways, impaired absorption, or excessive secretion caused by various reasons, resulting in partial or total, symmetric or asymmetric enlargement of the ventricular system, clinically manifested by the syndrome of increased intracranial pressure such as headache, vomiting, impaired consciousness or/and optic nerve papilledema, cranial decompression window ectasia, or cognitive impairment, urinary incontinence, and The normal cranial pressure hydrocephalus syndrome with three main evidence of gait instability. Since its first application by Kausch in 1908 and especially since the introduction of the flap system shunt in 1952, V-P shunt has become the most common clinical treatment for all types of hydrocephalus because of its wide indications, ease of operation, minimal surgical trauma, and established efficacy. However, multiple complications associated with this procedure, such as shunt blockage, infection, organ perforation, and excessive or inadequate shunts, are the main factors affecting the efficacy and are the topics facing neurosurgical clinics. In order to avoid and reduce the complications caused by intra-abdominal large omental wrapped shunts, scholars have used various technical methods, including fixation in the liver compartment, small omental cavity or pelvic cavity, and abdominal incisions such as subxiphoid, right upper abdomen, paramedian, left and right lower abdomen, all of which lack imaging assessment of the location of the abdominal end of the shunt and have different efficacy. In our group, a small subxiphoid mid-abdominal incision was used, and after placing the shunt into the abdominal cavity, the change in the position of the shunt was prospectively observed by abdominal plain film. The results of 40 cases in our group showed that after the abdominal end of the shunt was placed into the abdominal cavity, the abdominal end of the shunt entered the pelvic cavity in 77.5% of patients within 24 h, 87.5% within 3 days, and 97.5% within 7 days after surgery, relying on the action of their own intestinal peristalsis, even if they were in bed. Moreover, in the 5 cases followed up for more than 3 months, the abdominal end of the shunt was all in the pelvic cavity. One case in this group developed infection 1 year after surgery, and intraoperative confirmation of yellow staining of the wall of the terminal end of the abdominal end of the tube was estimated to be penetration into the intestinal cavity leading to retrograde intracranial infection; after controlling the infection in this patient, hydrocephalus was controlled after switching to V-A shunt. In the rest of the patients, no abdominal-related complications occurred, and all had good outcomes after shunting. One case in this group had an acute subdural hematoma 5 days after surgery, which was probably caused by bleeding at the puncture site or cortical vein bleeding after improvement of hydrocephalus. This example of concurrent skull repair might have prevented the occurrence of secondary intracranial hemorrhage. Compared with other site incisions, our group used a small straight subxiphoid incision to avoid the operation of cutting or/and separating the abdominal muscle layer, which was simple, convenient, less bleeding, and quick in opening and closing the abdominal cavity, and also shortened the time of the operation. Based on the preliminary results of this group, we believe that in V-P shunt, the abdominal end of the shunt does not require special treatment of fixing it to the liver compartment, small omental cavity or pelvic cavity. In order to avoid the occurrence of postoperative infection, obstruction and perforation caused by excessive length of the abdominal end, we believe that the following matters should be noted: 1. Preoperative disinfection should be strict, and unnecessary contact with the shunt device should be minimized intraoperatively; 2. Before connecting the shunt, measure the length from the ventricular puncture point to 5 cm below the plane of the anterior superior iliac crest of the patient, determine the length of the shunt that is the abdominal end, and cut the excessively long shunt from the proximal end; 3. Avoid blood seepage from the abdominal incision into the abdominal cavity, and wipe the blood from the wall of the shunt before entering the abdominal cavity; 4. After cutting the peritoneum, confirm that it is a smooth inner wall of the abdominal cavity, and then place the shunt downward, and ensure smoothness without obvious resistance. The method of using abdominal plain film to observe the position of the shunt is universal and easy to use, even if the patient cannot stand, it does not affect the determination of the position. The present group is only preliminary results, which need more cases and longer follow-up to confirm, and the use of three-dimensional imaging to determine the three-dimensional positional relationship of the terminal end of the shunt in the pelvis will help to better understand the efficacy after V-P shunt.