Evaluation Of Microsurgical Removal Of Petroclival Meningiomas

Objective:To evaluate and analyze the therapeutic outcomes of microsurgical removal of petroclival meningiomas (PCMs). And analyze the relative factors which may affect the extent of tumor resection and prognostic factors may affect further quality of patient life in order to explore the individual surgical strategy, decrease the complication and morbidity and improve the patient prognosis and further quality of life.Material and Method:Retrospectively analyzed clinical and followed-up data in a consecutive series of116patients with PCMs received microsurgical removal between July1991and October2013by the same surgeon.104cases were received the initial surgical treatment,9cases were tumor recurrence or progress which had undergone the previous surgery in other hospitals and3cases were tumor progress which had undergone the previous y-knife treatment. There were24male cases (20.7%) and92female cases (79.3%) with the average age of48.6±11.2(range from15to73). The main initial clinical symptoms were including nonspecific headache, facial numbness, trigeminal neuralgia, tinnitus, hearing loss, walking instability and so on with the duration ranging from7days to360months (M=18, QR=40.5). Depending on the tumor subtype, there were16cases (13.8%) of clivus type,45cases (38.8%) of petroclival type,11cases (9.5%) sphenopetroclival type and44cases (37.9%) of petroclivosphenoidal type with the average tumor size of44.6±10.7mm (range from15mm to80mm).97cases (83.6%) were treated visa suboccipital retrosigmoid approach including61cases (52.6%) with classical suboccipital retrosigmoid approach and36cases (31.0%) with suboccipital retrosigmoid-transtentorial approach,6cases (5.2%) were treated visa extended pterional approach approach,6cases (5.2%) were treated visa presigmoid combined supra-infratentorial approach and7cases (6.0%) were treated visa other kinds of approaches. Quality of life was measured using Karnofsky Performance Scale. The preoperative KPS was40-100with the average of75.2±12.5.Clinical history, preoperative and postoperative functional state, image results, surgical outcomes and tumor characteristic were all detailedly collected. The patients were followed up at regular intervals and functional state, quality of life and reviewed image results were totally recorded. The choice of surgical approaches, the extent of tumor resection, tumor recurrence and progress, further functional state and quality of life and the long-term survival rate were analyzed and studied statistically by software of IBM SPSS21.0. Many kind of statistical approaches were used to analyze the possible factors which may affect the extent of tumor removal, prognostic quality of life and long-term survival rate.Results The gross total removal of tumor (GTR) reached in73cases (62.9%). The subtotal removal (STR) achieved in25cases (21.6%). The partial removal (PR) was18cases (15.1%). Especially45cases (73.8%) reached GTR via classical suboccipital retrosigmoid approach and20cases (55.6%) of GTR reached by suboccipital retrosigmoid-transtentorial approach. There was no case died during the surgery and2cases (1.7%) died postoperatively. The main complications were including intracranial infection, pulmonary infection, intracranial hematoma, cerebral infarction and cerebrospinal fluid leakage. The new neurological dysfunction appeared in52cases (44.8%) postoperatively. The average day of patient in hospital postoperatively was16.5±10.1days (range from6days to77days). The postoperative KPS score was20-90with the average of66.4±14.6.22cases (51.2%) patients who reached non gross total resection (nGTR) received y-knife treatment.There were107cases (92.2%) getting followed-up, ranging from4to270months (M=24, QR=48).8patients (7.5%) died during the follow-up due to kinds of reasons.25cases (25.3%) were still in different level of neurological dysfunctional state and11cases (11.1%) were permanent disability in99alive cases during the follow-up. The KPS at the last visit ranged from50to100with the average of73.9±14.2. Tumor recurrence was identified in9cases (13.6%) in66cases of GTR which got followed up with the recurrence time from12to48months postoperatively. And8cases (12.5%) respectively and7cases (10.9%) died during follow-up. Tumor progress was identified in12cases (29.3%) in41cases of nGTR which got followed up including9cases (47.4%) who never received any postoperative treatment and3cases (14.3%) who received postoperative γ-knife treatment. The rate of tumor progression in the group which received y-knife treatment postoperatively was lower than the group which never received any treatment postoperatively (χ2=5.604, P=0.018). The overall survival rate was96.9%at1year,93.4%at3years,91.1%at5years and80.1%at10years in all the follow-ups; in addition, the R/P-free survival rate was98.2%at1year,91.5%at3years,87.9%at5years and67.7%at10years.Analyzed and compared by Chi-squared test or t test, between GTR group and nGTR group, there were significant differences in the days in hospital postoperatively (P=0.031), KPS score and excellent rates of KPS postoperatively (P=0.011and0.037, respectively), KPS score and excellent rates of KPS in follow-ups (P=0.001and0.017, respectively), but not in the rate of complication (P=0.377) and the new appearance of neurological dysfunction postoperatively (P=0.505). Analyzed by Chi-squared test univariate analysis and Logistic regression multivariate analysis, the extent of tumor removal were related with the factors of tumor size (OR=0.447,95%CI:0.171～1.169, P=0.092), texture (OR=0.488,95%CI:0.204～1.170, P=0.088), whether to invade into cavernous sinus (OR=0.083,95%CI:0.032～0.221, P=0.001) and whether to wrap neurovascular structures (OR=0.347,95%CI:0.131～0.916, P=0.033).Analyzed by Chi-squared test univariate analysis and Logistic regression multivariate analysis, the prognosis of further quality of life were related with the factors of quality of life preoperatively (OR=3.123,95%CI:1.139～8.562, P=0.027), tumor subtype (OR=1.896,95%CI:0.930～3.864, P=0.078), texture (OR=0.317,95%CI:0.127～0.793, P=0.014), invading extent of cranial fossa (OR=0.179,95%CI:0.048～0.667, P=0.010) and extent of tumor resection (OR=2.281,95%CI:0.795～6.540, P=0.095).Analyzed by Log-rank test univariate analysis and Cox proportional hazard regression model multivariate analysis, the long-term survival rate were related with the factors of sex (RR=0.192,95%CI:0.043～0.087, P=0.029), tumor texture (RR=7.418,95%CI:1.508～36.477, P=0.014) and extent of tumor resection (RR=1.179,95%CI:0.740～5.294, P=0.048). Conclusions:1. It is helpful to increase the rate of GTR by classifying the tumor subtype based on tumor growth orientation and surgical approach choosing. And suboccipital retrosigmoid-transtentorial approach is one of the simplest, most useful and most effective approaches.2. Microsurgical removal of PCMs needs doctors to be very familiar with the anatomy of petroclival region, their habitual surgical approach, practiced microsurgical skills and abundant experience.3. The total removal of PCMs can lead to excellent further prognosis. The extent of tumor removal is related with the factors of tumor size, texture, whether to invade into cavernous sinus and whether to wrap neurovascular structures.4. The prognosis of further quality of life are related with the factors of quality of life preoperatively, tumor subtype, texture, invading extent of cranial fossa and extent of tumor resection.5. The long-term survival rate is related with patient gender, tumor texture and the extent of tumor resection.6. The remnant of tumor postoperatively can be controlled effectively by y-knife treatment to get low rate of tumor progression.7. The doctors should take sufficient preoperative assessment to make a reasonable and individual treatment strategy and suitable surgical approaches should be chosen based on the different related factors affecting tumor removal, which is important to increase the therapeutic efficacy, decrease the postoperative complications and improve the quality of life for the patients.