Radicality of lateral ventricular neoplasms removal and risk factors of postoperative hemorrhagic complications

Introduction. Lateral ventricular neoplasms (tumors, vascular neoplasms, cysts) are rare and according to different sources comprise between 0.64 and 3.5 % of all brain tumors. Due to relatively slow growth, tumors can reach significant size before patient develops neurological symptoms. Surgery is the main method of treatment of lateral ventricular neoplasms, and in many cases radical removal can be achieved. The main complications after surgery are hydrocephalus and hemorrhages. The later frequently lead to escalation of neurological symptoms and sometimes require repeat surgical intervention. The success of intraventricular surgery consists of reasonable radicality and absence of complications.Aims. To evaluate the radicality and safety of lateral ventricular tumor removal through traditional approaches–transcallosal and transcortical – using arterial spin labeling (ASL perfusion) and to analyze the risk of hemorrhagic complications in the early postoperative period in the context of tumor location and blood supply.Materials and methods. At the N.N. Burdenko National Medical Research Center of Neurosurgery between 2017 and 2019 48 patients with space‑occupying lesions of the lateral ventricles were examined and treated with surgery. All patients were examined using the same MRI protocol before and after surgery: Т1‑weighted, Т1‑weighed contrast‑enhanced, 3D SPGR, Т2‑weighted, Т2‑FLAIR, DWI, T2‑FLAIR CUBE, SWAN, ASL perfusion. In 28 (58 %) cases, transcortical approach was used (through the frontal lobe in 24 cases, through the upper temporal lobe in 2 cases, through the parietal lobe in 2 cases); transcallosal approach was used in 16 (33 %) cases; combination approach (for advanced tumors of the lateral ventricles) was used in 3 (6 %) cases; supracerebellar infratentorial approach was used in 1 (2 %) case. Radicality of lateral ventricular tumor removal and risk factors for postoperative hemorrhagic complications using different approaches were evaluated based on the following parameters: tumor volume and location, sex, blood flow characteristics, presence of hydrocephalus.Results. In the compared groups I and II, similar rates of radical tumor removal were observed: 63 % for transcortical approach and 71 % for transcallosal approach. Hematomas in the tumor bed were more frequently observed in patients operated through transcortical approach (64 % vs. 31 % in transcallosal) without statistical significance. Generally, there were no statistically significant differences between surgical treatment results in groups I and II (p >0.05); this conclusion was confirmed in pseudo‑randomized patient subgroups selected through propensity score matching. Analysis of the association between hematoma in the postoperative period and baseline blood flow level showed that in the group with such hematomas mean tumor blood flow prior to surgery was almost twice as high as in the group without hemorrhagic complications after resection (80.6 vs. 49.4 ml/100 g/min, respectively).The following postoperative parameters are statistically significant for development of hematoma in the tumor bed: presence of hydrocephalus, Evans index in the early postoperative period.Conclusions. Correct and adequate choice of surgical approach considering anatomical location and advancement of the tumor, presence of hydrocephalus and surgeon’s preferences ensures high radicality of removal. Factors affecting the risk of hemorrhagic complications in the early postoperative period should be taken into account: sex, presence of hydrocephalus, neoplasm location and blood flow level.