Under The Pillow After The Middle Of The Road Related Venous Microdissection And Clinical Significance

Objective:To explore the microsurgical anatomy of the veins related to midline suboccipital approach in order to provide morphologr evidence for protection veins and decreasing postoperative complication when dealing with lesions in the posterior fossa.Methods:Twenty adult cadaveric skulls were perfused with red and blue latex respectively for simulating median posterior suboccipital approach.Veins and its tributaries related this approach were observed and measured under microscope. We retrospectively analyzed the clinical data of90patients with tumors in the midline of posterior fossa between July2001and July2011in Department of Neurosurgery, Affiliated Hospital of Qingdao University Medical College. All have been operated on through the suboccipital median craniotomy.We explored the causes of postoperative hydrocephalus and analyzed a variety of prevention and treatment of hydrocephalus,based on tumor location,pathological diagnosis and the degree of surgical resection..In addition,one illustrative case was presend.Results:The appearance rate of inferior vermian veins was100.0%and the outer diameters was (1.24±0.33) mm; the appearance rate of vein of the cerebellomedullary fissure was (87.5±5.2)%and the outer diameters was (0.85±0.24) mm; the appearance rate of vein of the inferior cerebellar peduncle was (77.5±6.6)%and the outer diameters was (0.43±0.11) mm; the appearance rate of the median posterior medullary vein was (55.0±l.l)%and the outer diameters was (0.50±0.13) mm; the appearance rate of the cerebellomedullary cistern vein was (35.0±10.7)%and the outer diameters was (0.52±0.25)mm; the appearance rate of inferior hemispheric veins was100.0%and the outer diameters was (1.83±0.46) mm. In90patients with tumors in the midline of posterior fossa,heamangioblastoma was24cases(26.7%), medulloblastoma was21cases (23.3%),astrocytic tumors was18cases (20.0%),metastatic tumors was18cases (20.0%), ependymal tumors was5cases (5.6%),primary central nervous lymphomas was3cases (3.3%),CNS neuroblastoma was1case (1.1%). Total excision was achieved in69patients (76.7%), near total excision in15patients (16.7%),subtotal excision in6patients (6.6%),partial excision and tissue biopsies were0case (0.0%).48cases underwent lumbar puncture for81times (1.7per person),8cases underwent lumbar catheter drainage for46days (5.8days per person),7cases underwent ventricle external drainage for39days (5.6days per person),3cases underwent ventriculo-peritoneal shut.GOSs of the patients at discharge were5points in45cases (50.0%),4points in33cases(36.7%),3points in8cases(8.9%),2points in3cases (3.3%),1point in1cases (1.1%)Conclusion:Prevention and treatment of postoperative hydrocephalus is the key to improve the efficacy of surgery. There are many reasons that could result in hydrocephalus in patients with tumors in the midline of posterior fossa,venous injury is one of the main. The microsurgical anatomy of the veins related to suboccipital median approach was intricate and highly variable.Enhancing the knowledge of the veins may be help to reduce intraoperative bleeding and decrease postoperative hydrocephalus and improve the short-term prognosis.