Treatment for Infection of Artificial Dura Mater Using Free Fascia Lata:

Dural Reconstruction Materials for the Repairing of Spinal Neoplastic Cerebrospinal Fluid Leaks

Spinal tumors often lead to more complex complications than other bone tumors. Nerve injuries, dura mater defect, and subsequent cerebrospinal fluid (CSF) leakage generally appear in spinal tumor surgeries and are followed by serious adverse outcomes such as infections and even death. The use of suitable dura mater replacements to achieve multifunctionality in fluid leakage plugging, preventing adhesions, and dural reconstruction is a promising therapeutic approach. Although there have been innovative endeavors to manage dura mater defects, only a handful of materials have realized the targeted multifunctionality. Here, we review recent advances in dura repair materials and techniques and discuss the relative merits in both preclinical and clinical trials as well as future therapeutic options. With these advances, spinal tumor patients with dura mater defects may be able to benefit from novel treatments.

Clinical management of dural defects: A review

Dural defects are common in spinal and cranial neurosurgery. A series of complications, such as cerebrospinal fluid leakage, occur after rupture of the dura. Therefore, treatment strategies are necessary to reduce or avoid complications. This review comprehensively summarizes the common causes, risk factors, clinical complications, and repair methods of dural defects. The latest research progress on dural repair methods and materials is summarized, including direct sutures, grafts, biomaterials, non-biomaterial materials, and composites formed by different materials. The characteristics and efficacy of these dural substitutes are reviewed, and these materials and methods are systematically evaluated. Finally, the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

Tissue Expanders in Staged Calvarial Reconstruction: A Systematic Review

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm ² , and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology ( p  = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

Autologous Free Fascia Lata Can Be Used as Dura Graft in the Salvage Treatment of Recalcitrant Postcraniotomy Intracranial Infection Caused by Multidrug-Resistant Gram-Negative Bacteria

Objective

The multidrug-resistant (MDR) gram-negative bacteria-induced intracranial infections after neurosurgical procedures represent a particular therapeutic challenge. Combining the removal of infected prosthetic meninge plus an appropriate antibiotic administration appears to be the only therapeutic strategy likely to succeed when the infection is complicated by artificial dura mater. This study aimed to assess the efficacy of free fascia lata as a substitute for dura reconstruction in the salvage treatment for such recalcitrant nosocomial infections.

Methods

The retrospective, observational study was conducted at Shanghai Tenth hospital. Patients with definite intracranial infection caused by MDR Gram-Negative bacteria who underwent salvage dura reconstruction using autologous free fascia lata were included in the study. Electronic medical data on clinical characteristics, underlying condition, bacterial culture, antibiotic susceptibilities, perioperative management, surgical techniques, outcome, and follow-up were collected and analyzed.

Results

19 patients were included in the study cohort. All these patients underwent salvage surgery, including removal of infected artificial dura substitute, achievement of complete dura seal with free fascia lata, and other adjunctive procedures to drain the CSF and infuse sensitive antimicrobial agents. Intraventricular or intrathecal administration of antibiotics, including Colistin (14 case), Tigecycline (1 case), Amikacin (1 case), was employed in 16 patients. The infection was cured in 17 patients. In-hospital death occurred in 3 patients. One died from multiple system/organ failure, 1 died from massive occipital ICH, 1 died from brain stem hemorrhage after ventricular-peritoneal shunt surgery. The patients remained without clinical evidence of recurrence during the follow-up period.

Conclusion

On the basis of a comprehensive approach to achieving prompt sterilization of causative pathogens and an optimal healing environment, free fascia lata can serve as a simpler but effective option for dura reconstruction even in the setting of a severe septic area for patients who otherwise need much more complicated and demanding tissue transfer surgery.

Applications of materials for dural reconstruction in pre-clinical and clinical studies: Advantages and drawbacks, efficacy, and selections

The dura mater provides a barrier to protect the tissue underneath and cerebrospinal fluid. However, dural defects normally cause cerebrospinal fluid leakage and other complications, such as wound infections, meningitis, etc. Therefore, the reconstruction of dura mater has important clinical significance. Current dural reconstruction materials include: homologous, acellular, natural, synthetic, and composite materials. This review comprehensively summarizes the characteristics and efficacy of these dural substitutes, especially in clinical applications, including the advantages and drawbacks of those from different sources, the host tissue response in pre-clinical studies and clinical practice, and the comparison of these materials across different surgical procedures. Furthermore, the selections of materials for different surgical procedures are highlighted. Finally, the challenges and future perspectives in the development of ideal dural repair materials are discussed.

An algorithm for one-stage malignant oncologic scalp reconstruction

Background

Scalp reconstruction has always been a challenging problem after oncological resection. Advanced surgical techniques can reconstruct any defects, but there are a large number of patients who cannot benefit from surgery for immature strategies. The authors here describe an algorithm for selecting the best reconstructive categories and minimizing complications according to the surgical defect of scalp tumors.

Methods

A single-institution retrospective review was conducted that included 173 patients with scalp tumors treated with surgery followed by reconstruction. Patients were identified by tumor type and nature; the location of scalp defect, size, and depth; the types of reconstructions and surgical. A systematic algorithm was developed according to our findings and current literature.

Results

Small defects (≤4 cm²) could be closed by primary closure. Medium defects (4–30 cm²) were reconstructed by local flaps. We routinely used skin graft for significant surgical defects (30–90 cm²). And the tumor’s location did not have an impact on reconstructive categories of above three types of defects. Free flaps should reconstruct very large-sized defects (>90 cm²) in frontal, temporal, and vertex locations while pedicle flaps suited for occipital defects due to its anatomic vicinity. The reconstruction algorithm of recurrent disease was like the management in primary tumors except for the medium size defect in the occipital region that was primarily reconstructed by a skin graft. Multiple free flaps reconstruction is the best possibility for total scalp resection. Free flap reconstruction is used mainly for composite resection of the scalp, calvarium, and dura.

Conclusions

Successful scalp reconstruction requires careful preoperative assessment, flexible and precisely intraoperative management. The algorithm based on defect size, depth, and location can supply some degree of guidelines when considering choosing suitable reconstructive procedures.

Treatment of CSF leakage and infections of dural substitute in decompressive craniectomy using fascia lata implants and related anatomopathological findings

PURPOSE

Decompressive craniectomy (DC) is widely used to treat raised intracranial pressure (ICP) in cranial trauma and stroke. It is accompanied by numerous complications. The aim of our study is to assess the surgical treatment of infections related to the use of a dural substitute with concurrent CSF leakage performed at our institution.

MATERIAL AND METHODS

A retrospective analysis of a series of 72 patients who underwent DC between 2011 and 2017 was performed. Seven cases (9%) showed infection related to the use of xenograft (bovine pericardium) and coexisting CSF leakage. Epidural/subdural empyemas were observed in seven cases; three in conjunction with an intracerebral abscess. For reconstruction, free anterolateral thigh fascia lata flaps were used, based on the size of the defect.

RESULTS

After removal of the dural substitute and the implant of free fascia lata, infection and CSF leaks resolved in all. An anatomopathological examination of the implant at the later time of cranioplasty (CP) showed the tissue had become vascularized exhibiting integration with the native dura. No complications related to the harvesting of the fascia lata were observed.

CONCLUSIONS

Fascia lata is a validated source of autologous grafts; it is cost-free and would appear to be the biological material most similar to the dura mater. The implanted material appears to maintain a lasting vitality when covered over with a well-vascularized scalp, even after a period of months, achieving a successful suppression of infection. Subsequent skull reconstruction is performed safely and easily using artificial bone.

[Structure and mechanical characteristics of spinal dura mater in different segments of sheep's spine]

Objective

To clarify the structure and biomechanical characteristics of the dura mater of the cervical, thoracic, and lumbar segments of sheep, in order to provide a theoretical reference for the study of artificial dura mater.

Methods

Five adult male white sheep were sacrificed. The dura mater of C ₅, T ₁₀, and L ₃ planes were obtained. The histological HE staining was used to observe the internal structure and the thickness of dura mater; the inner and outer surfaces morphology of the dura was observed by scanning electron microscopy (SEM); transmission electron microscopy (TEM) was used to observe the internal structure of dura mater and to measure the diameter of collagen fibers in each part of dura mater. The dura mater of C ₆, C ₇, T ₁₁, T ₁₂, L ₄, and L ₅ planes were taken for uniaxial biomechanical test, and modulus of elasticity, tensile strength, and elongation at break were measured.

Results

HE staining showed that the thickness of the cervical, thoracic, and lumbar dura mater gradually decreased, and the thickness of the dura mater was (268.19±15.91), (198.16±27.25), (103.74±21.54) μm, respectively, and the differences were significant ( P<0.05). SEM observation showed that there were more collagen fibers and fewer cells on the inner surface of the dura mater, while more cells were distributed on the outer surface, and the cells on the inner and outer surface were stretched along the longitudinal axis. TEM observation showed that the collagen fibers in the dura mater were interlaced and arranged in layers. The collagen fibers in the lamina were arranged in the same direction, and the collagen fibers between the lamina were arranged vertically. The diameters of collagen fibers in the cervical, thoracic, and lumbar dura mater were (68.04±21.00), (64.54±20.64), (60.36±19.65) nm, respectively, and the differences were not significant ( P>0.05). Uniaxial biomechanical tests results showed that there was no significant difference in modulus of elasticity, tensile strength, and elongation at break between the axial and transverse dura mater of the cervical dura mater ( P>0.05); the axial data of thoracic and lumbar segments were significantly larger than the transverse data ( P<0.05). The axial modulus of elasticity, tensile strength, and elongation at break of the dura mater of the cervical, thoracic, and lumbar dura mater were significantly different ( P<0.05) from the transverse ones, and showing a decreasing trend. Among them, the ratio of axial and transverse modulus of elasticity of cervical and thoracic dura were significantly smaller than that of lumbar segment ( P<0.05), and there was no significant difference between cervical segments and thoracic segments ( P>0.05).

Conclusion

The thickness of dura mater in sheep decreased gradually from head to tail. There are more collagen fibers and fewer cells on the inner surface of dura mater, while the outer surface of dura mater is covered by cells. The collagen fiberboard layers in the dura mater are arranged alternately, and have obvious anisotropic biomechanical characteristics, and the anisotropic biomechanical characteristics get more significant from the head to the tail.