Long-term results of fourth ventriculo-cisternostomy in complex versus simplex atresias of the fourth ventricle outlets.

Twelve cases of atresia of the fourth ventricle outlets are presented and they are classified into 2 types: simplex versus complex. Fourth ventriculo-cisternostomy is the treatment of choice. Based on the surgical experiences in simplex cases, new technical modifications were developed to make it applicable to the complex cases as well. The advantages and limitations of such operative approaches over other conventional shunt procedures are compared and the long-term postoperative results are listed. Hopefully, the surgical intervention described here may have opened a reasonable method for treating certain cases of the trapped fourth ventricle as a special variant of the complex atresia type. It is important to realize that knitted tubes are categorically unqualified for the surgical use like this.