Hydrocephalus is a common disease in neurosurgery, and its main treatment is currently a shunt procedure to introduce cerebrospinal fluid into other cavities in the body, among which the V-P shunt is recognized and widely used in clinical practice [1]. Although this shunt procedure has become a classic procedure for the treatment of hydrocephalus in recent times, there are still complications such as shunt blockage, infection and excessive drainage, which are the main causes of failure and a problem for neurosurgeons [2]. Jinlong Sun, Department of Neurosurgery, Shandong Qianfo Mountain Hospital
With the development of endoscopic instruments and application techniques, there is a place for neuroendoscopic techniques to treat hydrocephalus for conduit stenosis or other non-traffic hydrocephalus, especially the third ventricular floor fistula can be the preferred treatment for conduit stenosis hydrocephalus. The application of laparoscopy, on the other hand, has significantly improved the therapeutic effect of V-P shunt, reduced the trauma of this procedure, and is a more desirable surgical procedure for the treatment of traffic and obstructive hydrocephalus. This article focuses on the application of laparoscopic techniques in the treatment of hydrocephalus.
Application of laparoscopic V-P hepatic-diaphragmatic gap shunt
We have been using laparoscopy since 1996 to place the ventral end of the shunt into the hepatic-diaphragmatic space under the guidance of a television screen and fix it on the ventral surface of the diaphragm. To facilitate fixation and prevent obstruction of the ventral end of the shunt, we placed the end of the shunt into a 5-cm-long trocar with multiple holes, which also reduces the risk of the end of the shunt being wrapped around the greater omentum and avoiding perforation of the intestinal canal [3]. The advantages of using laparoscopy for this procedure are: small incision, minimal trauma, quick recovery, and almost no abdominal wall scarring. The artificial pneumoperitoneum makes the hepatic-diaphragmatic space well exposed, the field of view is large and open, the operating space is large, and the end of the shunt can be easily placed and fixed in the hepatic-diaphragmatic space. The possibility of adhesions and obstruction at the end of the shunt is significantly reduced by the “trocar” shunt. The intraoperative operation under the direct view of the TV screen can avoid damage to the liver and make it easy to fix the end of the shunt, and whether CSF is dripping from the end of the shunt and whether it is dripping smoothly can be seen through the laparoscope or screen during the operation, so that the shunt effect can be clarified; the occurrence of complications such as incisional infection, incisional leakage, incisional hernia, intestinal adhesions and intestinal obstruction is significantly reduced by follow-up comparison [3]. However, in patients who have undergone multiple V-P shunts with significant abdominal adhesions, it is not easy to perform further laparoscopic ventriculo-hepatodiaphragmatic interstitial shunts.
Neuroendoscopic treatment of hydrocephalus
Third ventriculostomy: The application of neuroendoscopy for third ventriculostomy is unique in that it can accurately reach the base of the third ventricle through anatomical positioning under direct vision and determine the size of the fistula made under direct vision, and it can accurately avoid the basilar artery and its branches to avoid intraoperative hemorrhage [4]. The current indications and anatomical requirements for the application of endoscopic third ventricle fundoplication are: (i) stenosis of the conduit or other non-traffic hydrocephalus; (ii) the third ventricle must be sufficiently wide, greater than 7 mm, without anatomical contraindications, such as large intermediate masses or too small a three-ventricular floor or occlusion of the fundic pool; (iii) a history of radiotherapy can be considered a contraindication; and (iv) traffic hydrocephalus is a contraindication. The determination of the interventricular foramen during intraoperative intracerebroventricular operations is important, and the diameter of the fistula hole should be greater than 5L to avoid postoperative adhesion blockage. Intraoperative injury to the vault, thalamic veins and internal cerebral veins should be avoided.
Compared with V-P shunt, the advantages of neuroendoscopic triple ventriculostomy for the treatment of hydrocephalus with aqueductal stenosis are: (1) minimal surgical trauma; (2) avoidance of the inconvenience and psychological burden caused by the internal placement of the tube in V-P shunt; (3) the cerebrospinal fluid entering the normal physiological circulation and absorption process through the fistula instead of diverting the cerebrospinal fluid outside the skull; (4) the surgery is performed under direct vision, making the surgery (4) the procedure is performed under direct vision making it safer; and (5) the complications of V-P shunt are avoided. Neuroendoscopic third ventriculostomy can be the treatment of choice for hydrocephalus with aqueductal stenosis.
Choroid plexus electrocautery: For traffic hydrocephalus, endoscopic coagulation of the choroid plexus is used to bring the production and absorption of cerebrospinal fluid to a new balance by reducing the secretion of cerebrospinal fluid, so that the development of hydrocephalus can be controlled, and only the villi of the choroid plexus need to be coagulated intraoperatively. This procedure is suitable for slow progressing traffic hydrocephalus, while for rapidly progressing hydrocephalus, the addition of a V-P shunt along with choroid plexus coagulation to reduce cerebrospinal fluid secretion can bring some refractory hydrocephalus under control. Coagulation of the choroid plexus greatly reduces the chance of encapsulation of the intracranial end of the shunt [5]. In some refractory hydrocephalus, it is often difficult to achieve satisfactory results with conventional V-P shunts. The use of endoscopic choroid plexus coagulation to reduce cerebrospinal fluid secretion can lead to control of some traffic hydrocephalus. The main complication after extensive choroid plexus electrocautery is hyperthermia, which can be treated with hormone therapy and mostly recovered within a week. For refractory hydrocephalus, endoscopic choroid plexus coagulation is a less invasive, safe and effective treatment method, and it can be the first choice for slowly progressing hydrocephalus.
Clear septal fistula: clinically common interventricular foramen adhesions can cause enlargement of one side of the ventricle, and if it causes obvious clinical symptoms, endoscopic clear septal fistula or fistula plus ventriculoperitoneal shunt can be performed. In cases of periventricular foramen tumors to be treated non-operatively, endoscopic biopsy of the lesion with septal fistula and unilateral ventriculoperitoneal shunt can also be performed. For compartmentalized hydrocephalus in which the ventricles do not communicate with each other, the use of a single V-P shunt can only relieve some of the ventricular cavities, whereas the endoscopic opening of the compartmentalized fistula will allow for the communication of the ventricular cavities and make the V-P shunt effective [6]. Clinically, interventricular foramen adhesions are common, causing enlargement of one ventricle, and if they cause significant clinical symptoms, endoscopic hyaline septal fistula or fistula plus ventriculoperitoneal shunt can be performed. For separated hydrocephalus in which the ventricles do not communicate with each other, unilateral V-P shunt can only release part of the ventricular cavity, while endoscopic penetration of the separated cavity can make the ventricular cavities communicate and make V-P shunt effective.
Auxiliary, guided placement: In V-P shunt, endoscopic guidance can be used to accurately place the ventricular end shunt in the frontal corner of the ventricle to avoid blockage of the shunt due to the wrapping of the choroid plexus; for patients with obstruction of the ventricular end shunt, it may be due to local adhesions at the ventricular end or the ventricular end being wrapped around the brain parenchyma due to the shrinking of the ventricle after the shunt. The shunt can be adjusted or replaced. We have been performing V-P shunts in some patients with hydrocephalus since 2002 using a combined neuroendoscopic and laparoscopic approach [7], with the aim of accurately placing the ventricular end of the shunt in the frontal horn of the lateral ventricle to avoid obstruction of the catheter opening due to the encapsulation of the choroid plexus. Similarly, with the help of laparoscopy, the ventral end of the shunt can be placed in the hepatic-diaphragmatic space, which is an inappropriate part of the greater omentum, to reduce the obstruction and complications of the ventral end of the shunt, which is also in line with the development direction of minimally invasive neurosurgery, and the advantages and disadvantages of this technique need to be summarized and analyzed after a large number of cases and long-term follow-up.