Free flap transfer for the treatment of intractable postcraniotomy subdural empyemas and epidural abscesses

Neural tissue tolerance to synthetic dural mater graft implantation in a rabbit durotomy model

In neurosurgical interventions, effective closure of the dura mater is essential to prevent cerebrospinal fluid leakage and minimize post-operative complications. Biodegradable synthetic materials have the potential to be used as dura mater grafts owing to their regenerative properties and low immunogenicity. This study evaluated the safety of ArtiFascia, a synthetic dura mater graft composed of poly(l-lactic-co-caprolactone acid) and poly(d-lactic-co-caprolactone acid), in a rabbit durotomy model. Previously, ArtiFascia demonstrated positive local tolerance and biodegradability in a 12-month preclinical trial. Here, specialized stains were used to evaluate potential brain damage associated with ArtiFascia use. Histochemical and immunohistochemical assessments included Luxol Fast Blue, cresyl Violet, Masson's Trichrome, neuronal nuclei,, Glial Fibrillary Acidic Protein, and ionized calcium-binding adaptor molecule 1 stains. The stained slides were graded based on the brain-specific reactions. The results showed no damage to the underlying brain tissue for either the ArtiFascia or control implants. Neither inflammation nor neuronal loss was evident, corroborating the safety of the ArtiFascia. This approach, combined with previous histopathological analyses, strengthens the safety profile of ArtiFascia and sets a benchmark for biodegradable material assessment in dura graft applications. This study aligns with the Food and Drug Administration guidelines and offers a comprehensive evaluation of the potential neural tissue effects of synthetic dura mater grafts.

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.

Comparison of the Morphologic and Mechanical Features of Human Cranial Dura and Other Graft Materials Used for Duraplasty

OBJECTIVE

This study aimed to compare the thickness and mechanical properties of the frontal; parietal; temporal; occipital human dura; autogenous grafts (facia lata, temporal fascia, galea aponeurotica); and artificial dura.

METHODS

Sagittal and transverse dura samples were obtained from standard regions of the cranial dura from 30 autopsies for histologic and mechanical property measurements. Identical measurements were made for the autogenous grafts artificial dura, and the results were statistically analyzed.

RESULTS

The thickness of the temporal (0.35 ± 0.11 mm), parietal (0.44 ± 0.13 mm), frontal (0.38 ± 0.12 mm), and occipital (0.46 ± 0.18 mm) dura showed regional variations. The parietal and occipital dura were significantly thicker than the temporal dura. The occipital dura was considerably thicker than the frontal dura. The frontal and temporal dura of males were significantly thicker than females. The sagittal maximum tensile force measurements were significantly greater than transverse, for the frontal, temporal, and occipital dura. The stiffness measurements in sagittal direction were greater than the measurements in transverse direction for the frontal dura. The mechanical properties and thickness of the autogenous and artificial dura were not similar to the human dura.

CONCLUSIONS

The thickness and mechanical properties of the regional cranial dura should be taken into consideration for a better cure and fewer complications. The mechanical properties of sagittal and transverse dura should be kept in mind for the preference of dura material. The present study's data can pave the way to produce artificial regional dura by mimicking the thickness and mechanical properties of the human dura.

Versatility of the Latissimus Dorsi Free Flap during the Treatment of Complex Postcraniotomy Surgical Site Infections

Background:

Some intractable cases of postcraniotomy infection, which can involve compromised skin, an open frontal air sinus, and residual epidural dead space, have been reported. In such cases, reconstructing the scalp and skull is challenging.

Methods:

Between 2009 and 2016, the author treated 12 patients with recalcitrant postcraniotomy surgical site infections with latissimus dorsi (LD) free flaps. The patients’ ages ranged from 37 to 79 years (mean, 63.5 years), and their underlying diseases included subarachnoid hemorrhaging (n = 5), brain tumors (n = 4), and cerebral arteriovenous malformations (n = 3).

Results:

The LD free flap was used for scalp reconstruction in 3 cases, scalp reconstruction and separation of the intracranial and nasal cavities in 5 cases, and the obliteration of epidural dead space in 4 cases. Debridement followed by staged cranial reconstruction was carried out in 8 cases, and single-stage cranial reconstruction was conducted in 2 cases. The bone defects of the other 2 cases, which were small, were filled with LD musculo-adipose free flaps. The postoperative local appearance of the wounds was acceptable in every case, and no complications occurred.

Conclusions:

The LD free flap is a versatile tool for the treatment of complex postcraniotomy surgical site infections. This vascularized muscle flap is useful for controlling local infections because of its abundant vascularity. Moreover, its variety of uses means that it can resolve several problems in cases involving complex cranial wounds.

Cranial Reconstruction following the Removal of an Infected Synthetic Dura Mater Substitute

Background:

The objective of this study was to describe the outcomes of an algorithmic approach to cranial reconstruction following the removal of an infected synthetic dura mater substitute due to postcraniotomy infection.

Methods:

A retrospective review was conducted of the cases of 12 patients who underwent cranial reconstruction from 2006 to 2013 after the removal of an infected expanded polytetrafluoroethylene sheet (a synthetic dura mater substitute) due to postcraniotomy infection.

Results:

Average patient age was 46 years (range, 19–70 years). Follow-up was 4.6 years. The expanded polytetrafluoroethylene sheets were implanted after decompressive craniectomy or after combined resection of the dura mater and a tumor. Epidural, but not subdural, abscesses were found in 6 patients, in whom a sufficient capsule developed underneath the synthetic dura mater. Both epidural and subdural abscesses were found in the remaining 6 patients, and the capsule remained intact after debridement of the subdural abscesses in half of them. Secondary cranial reconstruction was safely performed by leaving the capsule intact in the 9 cases in which no additional dural reconstruction was performed. In the remaining 3 patients, in whom no capsule remained after debridement, secondary cranial reconstruction was carried out by leaving the pericranium over the brain surface. None of the patients developed postoperative complications in follow-up periods.

Conclusions:

Staged cranial reconstruction after the removal of an infected synthetic dura mater substitute using an algorithmic approach is feasible and safe, produces satisfactory cosmetic results, and is not associated with any complications.