Analysis Of Petroclival Meningiomas With The Retrosigmoid Approach

Objective: To define optimal resection goals based on evaluating cranial nerve deficits,Karnofsky Performance Status(KPS)score and recurrence/progression rates.Evaluation and analysis of microsurgical treatment of petroclival meningiomas(PCMs)for the sake of exploring individualized surgical strategy,reduce complications and morbidity,improve long-term follow-up quality of life.Material and Method: The clinical and follow-up data of 39 consecutive patients with PCMs which have been resected by the simple retrosigmoid approach were analyzed retrospectively between January 2006 and December 2013.All of 39 cases were received the initial surgical treatment.There were 5 males(12.82%)and 34 females(87.28%).The average age of all cases is 53.79±7.94(range from 36 to 74).The most common clinical manifestations were headache or dizziness,facial numbness or pain,hemifacial paralysis or spasm,hearing loss,limb weakness,ataxia,dysphagia.Tumors were classified into four groups by size: small(diameters <1.0 cm)0 case,medium(diameters10–24 mm)3 cases,large(diameters 25–44 mm)29 cases,giant(diameters ?45 mm)7 cases.Quality of life was measured by the KPS scale.Preoperatively,cautious collection of sufficient clinical history-taking,physical examinations,neurological functions of cranial nerves,radiographic findings.Postoperatively,detailed records of tumor properties,recovery of injured cranial nerves during follow-up,radiographic recurrence or progression at regular follow-up and quality of life.Three subtypes of petroclival meningiomas: I,Tumors involving the petroclival region with major extension into the supratentorial area;II,Tumors involving the petroclival region with major extension into the infratentorial area;III,Tumors involving the petroclival region with major extension into the supratentorial and infratentorial area equally.The extent of tumor resection,cranial nerve deficits,tumor recurrence/progress,cranial nerve deficits and quality of life were analyzed.IBM SPSS 17.0 software for statistical analysis.Results: The gross total resection(GTR)was achieved in 11 cases(28.21%).The subtotal resection(STR)was fulfilled in 28 cases(71.79%).Overall clinical results were excellent with no resultant mortality or major morbidity.There were 10 cases(25.64%)of new neurological dysfunction postoperatively.Cranial nerve deficit occurred in 6 patients(54.55%)and 4 patients(14.28%)in GTR and STR group.There were 36 cases(92.31%)getting followed up with the average time of 41.53 months(ranging from 13 to 96 months).There were 7 cases(19.44%)still in the different state of nervous system dysfunction,and 3 patients(8.33%)had permanent disability during the follow-up period.The mean postoperative KPS score was 72.00±9.19 in GTR and 82.69±10.41 in STR at the last followed up.Gross total resection(GTR)was achieved in 11 patients(28.21%)without recurrence;Subtotal resection(STR)was achieved in 28 patients(71.79%)and progression occurred in 11.54% in this group.There was no progression in 11 patients who accepted Gamma Knife radiosurgery(GKRS)in STR group(8 cases accepted actively and 3 cases accepted passively).The rate of tumor progression between accepted Gamma Knife radiosurgery treatment and not accepted Gamma Knife radiosurgery treatment were not significant differences(Fisher exact test P=0.529)in STR group.Analyzed using t-test or Fisher exact test,between GTR group and STR group,the difference was statistically significant in KPS score(t=-2.844,P=0.007)and excellent rates of KPS in followed up(Fisher exact test P=0.018),between GTR group and STR group,the difference was statistically significant in new neurological dysfunction after surgery(Fisher exact test P=0.017).Conclusions: 1.Classification of petroclival meningiomas will contribute to the approach selection.2.Suboccipital retrosigmoid approach is a kind of simple approach,less postoperative complications.3.Gamma knife radiosurgery for residual tumors in petroclival meningiomas can be used to control residual tumor progression.4.It is important to lessen the postoperative complications and ameliorate the quality of life.5.Selectively pursuing STR with or without Gamma Knife radiosurgery of tumor remnants is a reasonable strategy.