Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation Type I in pediatric patients: a meta-analysis

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Surgery for Chiari malformation Type I (CM-I) is one of the most common neurosurgical procedures performed in children, although there is clearly no consensus among practitioners about which surgical method is preferred. The objective of this meta-analysis was to compare the outcome of posterior fossa decompression with duraplasty (PFDD) and posterior fossa decompression without duraplasty (PFD) for the treatment of CM-I in children.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors searched Medline–Ovid, The Cochrane Library, and the conference proceedings of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons (2000–2007) for studies meeting the following inclusion criteria: 1) surgical treatment of CM-I; 2) surgical techniques of PFD and PFDD being reported in a single cohort; and 3) patient age &lt; 18 years.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Five retrospective and 2 prospective cohort studies involving a total of 582 patients met the criteria for inclusion in the meta-analysis. Of the 582 patients, 316 were treated with PFDD and 266 were treated with PFD alone. Patient age ranged from 6 months to 18 years. Patients undergoing PFDD had a significantly lower reoperation rate (2.1 vs 12.6%, risk ratio [RR] 0.23, 95% confidence interval [CI] 0.08–0.69) and a higher rate of cerebrospinal fluid–related complications (18.5 vs 1.8%, RR 7.64, 95% CI 2.53–23.09) than those undergoing PFD. No significant differences in either clinical improvement (78.6 vs 64.6%, RR 1.23, 95% CI 0.95–1.59) or syringomyelia decrease (87.0 vs 56.3%, RR 1.43, 95% CI 0.91–2.25) were noted between PFDD and PFD.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Posterior fossa decompression with duraplasty is associated with a lower risk of reoperation than PFD but a greater risk for cerebrospinal fluid–related complications. There was no significant difference between the 2 operative techniques with respect to clinical improvement or decrease in syringomyelia.</jats:p></jats:sec>

Syrinx resolution after posterior fossa decompression in patients with scoliosis secondary to Chiari malformation type I

“…In general, pediatric patients have a better response to PFD than adults [5], implying that the more pediatric patients recruited for a study, the better the surgical outcome. Different surgical procedures might decompress the cerebellar tonsils to different extents or even exert a direct effect on the syrinx, resulting in different rates of significant syrinx improvement [4,8,[20][21][22][23]. Variability in the definition of significant improvement also may have led to contrary results among previous reports.…”

“…Results showed that syrinx improvement occurred mainly within 6 months and continued at a slow rate within 6 years after posterior fossa decompression [12]. Several factors, such as sex, preoperative size and syrinx length, have been reported as predictors of better surgical outcome after PFD [4,5,20]. Badie et al [27] reported that female patients have a better response to PFD than male patients because female patients have a lower posterior fossa volume.…”

“…There is broad consensus on the role of mechanical blockage of cerebrospinal fluid flow at the craniocervical junction in the pathogenesis of SM secondary to CMI [1,2]. Posterior fossa decompression (PFD) is currently preferred by most surgeons as the standard surgical option in the treatment of SM secondary to CMI [3][4][5][6]. This results in decompression of the cerebellar tonsil restores the normal cerebrospinal fluid flow [7].…”

Delayed resolution of syrinx after posterior fossa decompression without dural opening in children with Chiari malformation Type I

“…6,9,10,46 Despite only 70% of our patients showing radiographic improvement of the syrinx, 100% had initial improvement postoperatively and 88% remained asymptomatic or with minimal symptoms at last follow-up. These results are similar to the study by Wetjen et al, where at 6 months after PFD with dural opening, 96% of the patients experienced some degree of clinical improvement while only 86% had radiographic improvement of the syrinx; after 2 years, 68% remained mildly symptomatic even though 100% had radiographic improvement of the syrinx.…”

“…4,11,25,26,32,35,42 High rates of radiographic syrinx improvement have been reported after PFD with dural opening in pediatric CM-I, with symptom resolution often occurring prior to syrinx resolution and scoliosis improvement often occurring after. [1][2][3][4][5][6][7][8][10][11][12][15][16][17]20,26,27,[29][30][31][32][33][34][35]42,44 In part because syrinx improvement has been noted to occur in the majority of 17,19,36,39 At the 2006 American Society of Pediatric Neurosurgeons meeting, for example, a survey of 50% of the membership demonstrated that for children with a symptomatic CM-I and syrinx, only 4% would perform nondural opening surgery and another 4% would use ultrasound to guide whether to add duraplasty, with the vast majority opting for duraplasty with or without tonsillar resection. 36 However, controversy exists over whether the dura must be opened for successful surgery for pediatric CM-I with or without a syrinx, with good clinical outcomes being reported for a variety of methods.…”