Dual Dural Patch Graft With AlloDerm and DuraGen Underlay for Duraplasty in Chiari Malformation Results in Significantly Decreased Cerebrospinal Fluid Leak Complications

Operative Neurosurgery 24:162–167, 2023

Grafts available for posterior fossa dural reconstruction after Chiari decompression surgery include synthetic, xenograft, allograft, and autograft materials. The reported rates of postoperative pseudomeningocele and cerebrospinal fluid leak vary, but so far, no dural patch material or technique has sufficiently eliminated these problems.

OBJECTIVE: To compare the incidence of graft-related complications after posterior fossa surgery using AlloDerm alone vs AlloDerm with a DuraGen underlay.

METHODS: We performed a retrospective single-center study of a cohort of 106 patients who underwent Chiari decompression surgery by a single surgeon from 2014 through 2021. Age, sex, body mass index, tonsillar descent, syrinx formation, type of dural graft, and follow-up data were analyzed using univariate and χ2 statistical tests.

RESULTS: The AlloDerm-only group had a percutaneous cerebrospinal fluid (CSF) leak rate of 8.6% vs a 0% rate in the dual graft group (P = .037). At initial follow-up, there was a 15.5% combined rate of pseudomeningocele formation plus CSF leak in the AlloDerm-only group vs 18.8% in the AlloDerm + DuraGen group (P = .659). However, the pseudomeningoceles were larger in the AlloDerm-only cohort (45.5 vs 22.4 mm anteroposterior plane, P = .004), and 5 patients in this group required operative repair (56%). All pseudomeningoceles resolved without reoperation in the AlloDerm + DuraGen group (P = .003).

CONCLUSION: The use of a DuraGen underlay with a sutured AlloDerm dural patch resulted in significantly fewer CSF-related complications and eliminated the need for reoperation compared with AlloDerm alone. This single-center study provides evidence that buttressing posterior fossa dural grafts with a DuraGen underlay may decrease the risk of postoperative complications.

Dura Management Strategies in the Surgical Treatment of Adult Chiari Type I Malformation

Operative Neurosurgery 23:304–311, 2022

Symptomatic Chiari I malformation is treated with suboccipital decompression and C1 laminectomy. However, whether the dura should be opened (durotomy) or enlarged with a graft (duraplasty) remains unclear.

OBJECTIVE: To compare outcomes in adult Chiari I malformation patients treated with duraplasty, durotomy, or without dural opening (“mini-decompression”).

METHODS: A retrospective, multicenter, population-based cohort study was performed of all adult patients surgically treated for a Chiari I malformation at 3 regional neurosurgical centers between 2005 and 2017. Three different dura management strategies were favored by the participating hospitals, with data stratified accordingly. The primary outcome was measured using the Chicago Chiari Outcome Scale (CCOS), dichotomized into favorable (CCOS ≥13) or unfavorable (CCOS ≤12). Propensity score matching was used to adjust for potential confounders in outcome comparisons.

RESULTS: In total, 318 patients were included, of whom 52% were treated with duraplasty, 37% with durotomy, and 11% with mini-decompression. In total, 285 (90%) showed a favorable surgical outcome (CCOS ≥13). Duraplasty was associated with more favorable CCOS and shorter hospital stay compared with durotomy, both in unadjusted (93% vs 84%. P = .018 and 6.0 vs 8.0 days, P < .001) and adjusted analyses (92% vs 84%, P = .044 and 6.0 vs 8.0 days, P < .001). Mini-decompression was excluded from the adjusted analyses because of its small sample size.

CONCLUSION: In this study of adult Chiari I malformation, posterior fossa decompression with duraplasty was associated with more favorable postoperative outcome, as determined by the CCOS, compared with posterior fossa decompression with durotomy alone.

Randomized controlled study comparing 2 surgical techniques for decompressive craniectomy: with watertight duraplasty and without watertight duraplasty

J Neurosurg 129:1017–1023, 2018

Decompressive craniectomy (DC) is a widely used procedure in neurosurgery; however, few studies focus on the best surgical technique for the procedure. The authors’ objective was to conduct a prospective randomized controlled trial comparing 2 techniques for performing DC: with watertight duraplasty and without watertight duraplasty (rapid-closure DC).

METHODS The study population comprised patients ranging in age from 18 to 60 years who were admitted to the Neurotrauma Service of the Hospital da Restauração with a clinical indication for unilateral decompressive craniectomy. Patients were randomized by numbered envelopes into 2 groups: with watertight duraplasty (control group) and without watertight duraplasty (test group). After unilateral DC was completed, watertight duraplasty was performed in the control group, while in the test group, no watertight duraplasty was performed and the exposed parenchyma was covered with Surgicel and the remaining dura mater. Patients were then monitored daily from the date of surgery until hospital discharge or death. The primary end point was the incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections). The following were analyzed as secondary end points: clinical outcome (analyzed using the Glasgow Outcome Scale [GOS]), surgical time, and hospital costs.

RESULTS Fifty-eight patients were enrolled, 29 in each group. Three patients were excluded, leaving 27 in the test group and 28 in the control group. There were no significant differences between groups regarding age, Glasgow Coma Scale score at the time of surgery, GOS score, and number of postoperative follow-up days. There were 9 surgical complications (5 in the control group and 4 in the test group), with no significant differences between the groups. The mean surgical time in the control group was 132 minutes, while in the test group the average surgical time was 101 minutes, a difference of 31 minutes (p = 0.001). The mean reduction in total cost was $420.00 USD (a 23.4% reduction) per procedure in the test group.

CONCLUSIONS Rapid-closure DC without watertight duraplasty is a safe procedure. It is not associated with a higher incidence of surgical complications (CSF leak, wound infection, brain abscess, or subgaleal fluid collections), and it decreased surgical time by 31 minutes on average. There was also a hospital cost reduction of $420.00 USD (23.4% reduction) per procedure. Clinical trial registration no.: NCT02594137 (clinicaltrials.gov)


Chiari I malformation: surgical technique, indications and limits

Acta Neurochir (2018) 160:213–217

Chiari malformation type I (CM-I) is a rare disease characterised by herniation of cerebellar tonsils below the foramen magnum with associated anomalies of posterior fossa. We describe here the surgical technique, indications and limits of surgical treatment.

Method The authors describe the surgical technique, including: posterior fossa decompression, opening of the foramen of Magendie and duraplasty in case of CM-I.

Conclusions Posterior fossa decompression plus duraplasty is a safe and effective procedure for patients with CM-I malformation.

Augmented Autologous Pericranium Duraplasty in 100 Posterior Fossa Surgeries—A Retrospective Case Series

Neurosurgery 71[ONS Suppl 2]:ons302–ons307, 2012

Primary closure of the dura in posterior fossa (p-fossa) surgeries is technically difficult and usually requires the use of a dural substitute. A variety of substitutes are currently available and data suggest that autologous materials are preferred in comparison with nonautologous substitutes.

OBJECTIVE: To report our experience using locally harvested autologous pericranium as a dural substitute in patients who underwent p-fossa surgeries.

METHODS: Retrospective analysis of patients who had undergone p-fossa craniotomies between 2005 and 2011. All patients received locally harvested autologous pericranium for duraplasty augmented with a dural sealant. Data were reviewed for complications including: surgical site infection, meningitis, cerebrospinal fluid leak, the radiographic formation of a pseudomeningocele, and any new neurological symptoms related to the incision or repair.

RESULTS: One hundred patients were identified. Indications for surgery included tumor, vascular lesions, or hemorrhage requiring surgical intervention, symptomatic Chiari I malformation, microvascular decompression for trigeminal neuralgia, and trauma requiring surgical decompression. The complication rate was 1% with 1 patient developing an nonsteroidal anti-inflammatory drug-induced aseptic meningitis and graft dehiscence requiring surgical revision.

CONCLUSION: Autologous pericranium with dural sealant augmentation is an effective way to repair the durotomy in p-fossa surgeries. To the best of our knowledge, this is currently the largest study using this technique in the adult neurosurgical literature. Our results report a much lower rate of complications in comparison with other duraplasty studies.

Results of the Prospective, Randomized, Multicenter Clinical Trial Evaluating a Biosynthesized Cellulose Graft for Repair of Dural Defects

Neurosurgery 69:1093–1104, 2011 DOI: 10.1227/NEU.0b013e3182284aca 

After intradural cranial surgery, a dural substitute is often required for dural closure. Although preferred, limitations of autograft include local availability and additional surgical site morbidity. Thus, allografts, xenografts, and synthetics are frequently used.

OBJECTIVE: To report 6-month results of a randomized, controlled trial of a biosynthesized cellulose (BSC) composed duraplasty device compared with commercially available dural replacements.

METHODS: A total of 99 patients (62 BSC; 37 control) were treated on protocol, using a 2:1 (BSC:control) blocked randomization schedule. Physical examinations were performed pre- and postoperatively within 10 days and at 1, 3, and 6 months. Magnetic resonance imaging was performed preoperatively and at 6 months. The primary study endpoint was the absence of pseudomeningocele and extracerebral fluid collection confirmed radiographically and the absence of cerebrospinal fluid fistula at 6 months.

RESULTS: At 6 months, the primary hypothesis, noninferiority of the BSC implant compared with the control group, was confirmed (P = .0206). Overall success was achieved by 96.6% of BSC and 97.1% of control patients. No significant difference was revealed between treatment groups for surgical site infection (P = 1.0000) or wound healing assessment (P $ .3685) outcomes, or radiologic endpoints (P $ .4061). Device strength and seal quality favored BSC.

CONCLUSION: This randomized, controlled trial establishes BSC as noninferior to commercially available dural replacement devices. BSC offers a hypothetical advantage concerning prion and other infectious agent exposure; superior handling qualities are evident. Longer term data are necessary to identify limitations of BSC and its potential equivalence to the gold standard of pericranium.

“In-window” craniotomy and “bridgelike” duraplasty: an alternative to decompressive hemicraniectomy

J Neurosurg 113:982–989, 2010. DOI: 10.3171/2009.11.JNS09674

The object of this study was to propose an alternative procedure to the classic decompressive hemicraniectomy using an “in-window” craniotomy and a “bridgelike” duraplasty.

Methods. The authors performed a large, almost rectangular craniotomy involving the frontal, temporal, and parietal bones and part of the occipital squama in 5 patients. The dura mater is opened and its area is enlarged using a rectangular dural patch of the surgeon’s choice in the form of a bridge between the anterior and posterior dural edges. With a vertical cut, the bone flap is divided into 2 similarly sized pieces that function as “window lids.” The outer frontal and occipital sides of the bone are tied to the skull border at 2 points to function as a hinge joint. The angle of the bone cut must be beveled outward (inclination ~ 45° of the bone drill or saw) to allow the bone flap to rest on the adjacent skull and prevent its slippage toward the intracranial cavity.

Results. The above procedures were performed with effective control of intracranial hypertension due to cerebral venous sinus thrombosis, brain trauma, intracerebral hematoma, or malignant cerebral ischemia.

Conclusions. Decompressive surgery, which uses an in-window craniotomy that gradually opens according to the intracranial pressure, is an alternative solution for deploying autologous material. The procedure has the advantage of obviating the need for a second surgical procedure to close the bone defect, and thus preventing the metabolic cerebral impairment associated with the absence of an overlying skull.

Decompression of Chiari malformation with and without duraplasty: morbidity versus recurrence

J Neurosurg Pediatrics 5:474-478, 2010. DOI: 10.3171/2010.1.PEDS09218

The optimal surgical management of Chiari malformation (CM) is evolving. Evidence continues to accrue that supports decompression without duraplasty as an effective treatment to achieve symptomatic relief and anatomical decompression. The risks and benefits of this less invasive operation need to be weighed against decompression with duraplasty.

Methods. The authors performed a retrospective review of all CM decompressions from 2003 to 2007. All operations were performed by a single surgeon at a single institution. Data were analyzed for outcome, postoperative morbidity, and recurrence.

Results. Of 121 unique patients, 56 underwent posterior fossa decompressions without duraplasty (PFD) and 64 patients underwent posterior fossa decompressions with duraplasty (PFDD). Of the 56 PFD patients, 7 (12.5%) needed a subsequent PFDD for symptomatic recurrence. Of the 64 patients who underwent a PFDD, 2 (3.1%) needed a repeated PFDD for symptomatic recurrence. Patients treated with PFDD had an average operative time of 201 minutes in contrast to 127 minutes for those who underwent PFD (p = 0.0001). Patients treated with PFDD had average hospital stays of 4.0 days, whereas that for patients treated with PFD was 2.7 days (p = 0.0001). While in the hospital, patients treated with PFDD used low-grade narcotics, intravenous narcotics, muscle relaxants, and antiemetic medications at statistically significant differing rates.

Conclusions. While PFD was associated with a higher rate of recurrent symptoms requiring repeated decompression, this may be justified by the significantly lower morbidity rate. Clearer delineation of the trade-off between morbidity and recurrence may be used to help patients and their families make decisions regarding care.