**3.1 History and background**

In 1952, Nulsen and Spitz began the era of ventricular cerebrospinal fluid (CSF) shunting [14]. Due to the lack of initial encouraging results, not until 1970s, an interest in ETV for treating obstructive hydrocephalus was renewed when the imaging capability of endoscopes had a remarkable improvement. In 1978, Vries described his experience treating five patients with hydrocephalus, in whom he demonstrated that ETVs were technically feasible using a fiberoptic endoscope [15]. In the small series of 24 patients with various forms of hydrocephalus, Jones and colleagues described a 50% shunt-free success rate for ETV, initially in 1990 [16]. They reported a better success rate of 61% in a series of 103 patients 4 years later [17]. Obstructive hydrocephalus which has resulted from either benign aqueductal stenosis or compressive

#### *Endoscopy in Neurosurgery DOI: http://dx.doi.org/10.5772/intechopen.100252*

periaqueductal benign or malignant mass lesions are being treated primarily with ETV in the modern era. In the current time, the shunt-free success rate ranges from 80 to 95% [2].

The indications for ETV are expanding to meningomyelocele, Chiari malformation or Dandy-Walker-related hydrocephalus cases. Few studies reported fairly good success rates after ETV for cases of communicating hydrocephalus in idiopathic normal pressure hydrocephalus [18]. In selected cases, ETV is becoming more and more preferable to ventriculoperitoneal (VP) shunt placement due to avoidance of shunt dependency and complications that come with the shunting [19]. With introduction of improved endoscopic techniques, ETV is now used to treat hydrocephalus following shunt malfunction or infection and refractory slit-ventricle syndrome [18].
