Ventral Intrameningeal Cyst Treatment and Management: Technical Note.

BACKGROUND: Intrameningeal cysts are rare lesions without definitive etiologies that can involve the dura or arachnoid mater. Spinal arachnoid cysts have been described, and several different etiologies have been hypothesized. This includes one-way valve mechanisms, traumatic herniation of arachnoid through the dura, and abnormal arachnoid membrane proliferation. To the authors' knowledge, no such descriptions exist regarding purely dural-based cystic lesions; however, the authors hypothesize similar mechanisms may be involved. Most notably, a traumatic injury to the dura leading to a one-way valve mechanism may allow for egress of cerebrospinal fluid between the dural layers, splitting them open. This progressive enlargement can lead to displacement of neural elements and subsequent neurological compromise. METHODS: We describe a 17-year-old girl who presented with progressive neck and back pain, left upper-extremity numbness, bilateral lower-extremity weakness, paresthesias, and numbness without obvious etiology despite an extensive neurologic investigation. She had undergone conservative management options including multiple medications, physical and chiropractic therapy, and epidural steroid injections. Computed tomography myelography revealed a cerebrospinal fluid leak into the lumbar epidural space for which surgical exploration was performed. Despite utilizing fluoroscopy and intrathecal fluorescein, no leak source was identified. Fluid collection was found contained within the dural layers rather than the epidural space. RESULTS: An intracystic blood patch was performed with near-complete resolution of the lesion by 6-week follow-up and near-complete return of neurologic function. CONCLUSIONS: Ventral panspinal cysts are an exceedingly rare cause of radiculopathy and myelopathy that can be resolved by an intracystic blood patch.

Soft tissue grafts for dural reconstruction after meningioma surgery.

The meninges are involved in various pathologies and are often directly or indirectly severed during surgical procedures, especially the dura mater. This can pose a real challenge for the surgeon, as a proper reconstruction of the meninges is important to prevent complications such as cerebrospinal fluid leak (CSF). A variety of techniques for dural reconstruction have been described, employing natural and artificial materials. A novel technique for dural reconstruction involves soft tissue grafts in the form of fibrous or fibromuscular flaps, which are placed on the dural defects to seal the gaps. These soft tissue grafts represent an appropriate scaffold for cell ingrowth and fibrosis, thus preventing CSF. In this pilot study, we described the application of soft tissue grafts for dural reconstruction in 10 patients who underwent convexity meningioma surgery.

The effect of vancomycin powder on human dural fibroblast culture and its implications for dural repair during spine surgery.

OBJECTIVE Surgical site infections (SSIs) are a major source of morbidity after spinal surgery. Several recent studies have described the finding that applying vancomycin powder to the surgical bed may reduce the incidence of SSI. However, applying vancomycin in high concentrations has been shown in vitro to inhibit osteoblast proliferation and to induce cell death. Vancomycin may have a deleterious effect on dural healing after repair of an intentional or unintentional durotomy. This study was therefore undertaken to assess the effect of different concentrations of vancomycin on a human dura mater cell culture. METHODS Human dura intended for disposal after decompressive craniectomy was harvested. Explant primary cultures and subcultures were subsequently performed. Cells were characterized through common staining and immunohistochemistry. A growth curve was performed to assess the effect of different concentrations of vancomycin (40, 400, and 4000 µg/ml) on cell count. The effect of vancomycin on cellular shape, intercellular arrangement, and viability was also evaluated. RESULTS All dural tissue samples successfully developed into fusiform cells, demonstrating pseudopod projections and spindle formation. The cells demonstrated vimentin positivity and also had typical features of fibroblasts. When applied to the cultures, the highest dose of vancomycin induced generalized cell death within 24 hours. The mean (± SD) cell counts for control, 40, 400, and 4000 µg/ml were 38.72 ± 15.93, 36.28 ± 22.87, 19.48 ± 6.53, and 4.07 ± 9.66, respectively (p < 0.0001, ANOVA). Compared with controls, vancomycin-exposed cells histologically demonstrated a smaller cytoplasm and decreased pseudopodia formation resulting in the inhibition of normal spindle intercellular arrangement. CONCLUSIONS When vancomycin powder is applied locally, dural cells are exposed to a concentration several times greater than when delivered systemically. In this in vitro model, vancomycin induced dural cell death, inhibited growth, and altered cellular morphology in a concentration-dependent fashion. Defining a safe vancomycin concentration that is both bactericidal and also does not inhibit normal dural healing is necessary.

Intraforaminal ozone therapy and particular side effects: preliminary results and early warning.

BACKGROUND: The term "low back pain syndrome" represents a complex nosological entity. The therapeutic approach is often only symptomatic and not etiologic. METHODS: Since 2013, 186 patients (97 males and 89 females, mean age 59.8 years) have undergone microsurgery for lumbar disc hernia or lumbar segmental stenosis. Among these patients, 23 had been previously treated with ozone therapy by the intraforaminal approach and 28 by intraforaminal steroid injections in other hospitals between 12 and 24 months before our clinical evaluation. These patients received 16 applications in an 8-week period (standard therapy). RESULTS: During the surgery, many hard adhesions between the soft tissues and bony structures were unexpectedly discovered. In particular, it was noted that the root contracted and had firm adhesions to the dural sac and/or fragmented disc, which were difficult to resolve. These specific pathological patterns were observed only in the patients who received ozone injections by the intraforaminal approach. We did not find any pathological abnormalities in the patients who did not receive any injections or who received intraforaminal steroid injections. Thus, we could exclude that the tissue damage was due to the mechanical action of the needle. CONCLUSION: It is important to assert that ozone therapy procedures can be associated with several major complications. Therefore, performing a revision of the guidelines and protocols for ozone therapy application is indispensable.

Cerebrospinal fluid reconstitution via a perfusion-based cadaveric model: feasibility study demonstrating surgical simulation of neuroendoscopic procedures.

Cadaveric surgical simulation carries the advantage of realistic anatomy and haptic feedback but has been historically difficult to model for intraventricular approaches given the need for active flow of CSF. This feasibility study was designed to simulate intraventricular neuroendoscopic approaches and techniques by reconstituting natural CSF flow in a cadaveric model. In 10 fresh human cadavers, a simple cervical laminectomy and dural opening were made, and a 12-gauge arterial catheter was introduced. Saline was continuously perfused at physiological CSF pressures to reconstitute the subarachnoid space and ventricles. A neuroendoscope was subsequently inserted via a standard right frontal bur hole. In 8 of the 10 cadavers, adequate reconstitution and endoscopic access of the lateral and third ventricles were achieved. In 2 cadavers, ventricular access was not feasible, perhaps because of a small ventricle size and/or deteriorated tissue quality. In all 8 cadavers with successful CSF flow reconstitution and endoscopic access, identifying the foramen of Monro was possible, as was performing septum pellucidotomy and endoscopic third ventriculostomy. Furthermore, navigation of the cerebral aqueduct, fourth ventricle, prepontine cistern, and suprasellar cistern via the lamina terminalis was possible, providing a complementary educational paradigm for resident education that cannot typically be performed in live surgery. Surgical simulation plays a critical and increasingly prominent role in surgical education, particularly for techniques with steep learning curves including intraventricular neuroendoscopic procedures. This novel model provides feasible and realistic surgical simulation of neuroendoscopic intraventricular procedures and approaches.

Effectiveness of a new gelatin sealant system for dural closure.

OBJECTIVES: Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage. METHODS: The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated. RESULTS: The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P < 0·001) or the PEG-based hydrogel sealant (46·3 ± 20·9 mmHg, P  =  0·007). Bonding strength was higher for the gelatin glue than fibrin glue (P < 0·001) or PEG-based hydrogel sealant (P  =  0·001). The maximum intracranial pressure in the in vivo model was higher for the gelatin glue group (59·0 ± 2·2 mmHg) than the control group (13·8 ± 4·0 mmHg, P < 0·001). Tissue adhesion was lower for the gelatin glue group than the control group (P  =  0·005). DISCUSSION: The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.

Non-pharmacological experimental treatments for spinal cord injury: a review.

INTRODUCTION: Spinal cord injury is a complex result of primary mechanical damage and the secondary vascular compromise and inflammatory reactions. Depending on timing, different treatment modalities may have various effects. CONCLUSIONS: We review the latest advances in terms of non-pharmacological experimental treatments.

Supracerebellar-supratrochlear and infratentorial-infratrochlear approaches: gravity-dependent variations of the lateral approach over the cerebellum.

OBJECTIVE: Lateral supracerebellar-infratentorial approaches are established for lesions in ambient cistern and posterolateral midbrain, but published surgical experiences do not describe results with this approach in the sitting position. Gravity retraction of the cerebellum opens this surgical corridor and dramatically alters exposure, creating 2 variations of the lateral supracerebellar-infratentorial approach: the supracerebellar-supratrochlear approach and the infratentorial-infratrochlear approach. METHODS: We reviewed our experience treating cavernous malformations and arteriovenous malformations (AVMs) of the posteroinferior thalamus and posterolateral midbrain by use of supracerebellar-supratrochlear and infratentorial-infratrochlear approaches. Microsurgical technique, clinical data, radiographic features, and neurological outcomes were evaluated. RESULTS: During an 11-year surgical experience with 341 cavernous malformation patients and 402 AVM patients, 8 patients were identified, 6 with cavernous malformations and 2 with AVMs. Infratentorial-infratrochlear approaches were used in 4 patients (50%), including 3 with inferolateral midbrain cavernous malformations. Supracerebellar-supratrochlear approaches were used in 4 patients (50%), including 2 with posterior thalamic lesions surfacing on pulvinar. Resections were radiographically complete in all cases. There were no new, permanent neurological deficits, nor were there any medical or surgical complications. There has been no evidence of rebleeding or recurrence. CONCLUSIONS: Gravity retraction of the cerebellum transforms the lateral supracerebellar-infratentorial approach, enhancing exposure and approach trajectories that can be achieved with patients in prone or lateral positions. The increased upward viewing angle of the supracerebellar-supratrochlear approach accesses the posteroinferior thalamus. The increased downward-viewing angle of the infratentorial-infratrochlear approach accesses cerebellomesencephalic fissure and posterolateral midbrain. These approaches open wide corridors for safe surgical resection of symptomatic cavernous malformations and AVMs.

Allogeneic epidural blood patch in the setting of persistent spinal headache and disseminated coccidioidomycosis.

In most cases of post-dural puncture headache, the positional symptoms will resolve spontaneously within 2 weeks. Conservative therapies include oral analgesics and hydration, bed rest, and abdominal binders. For refractory cases, an autologous epidural blood patch remains the treatment of choice. However, in certain cases the use of autologous blood for the blood patch may place the patient at risk for infectious or malignant contamination of the central nervous system. Coccidioidomycosis results from inhalation of the arthroconidia (spore) stage of the fungal lifecycle. The most common manifestation of coccidioidomycosis is acute pulmonary symptoms, while the most feared complication is meningitis. Immunocompromised patients are at increased risk of fungemia; therefore, introduction of fungal elements into the central nervous system can occur if autologous blood is used for an epidural blood patch. We report a case of persistent dural-puncture headache in the setting of disseminated coccidioidomycosis. An autologous blood epidural blood patch was considered but deferred due to risk of coccidioidomycosis meningitis. Other epidural space interventions such as fibrin glue injection or saline infusions were judged to be too imprecise or ineffective. The patient was successfully treated with allogeneic blood donated by his wife, but only after testing of her blood as is required for any directed blood donation. Allogeneic epidural blood patches are an option for refractory dural puncture headaches when autologous blood may cause meningitis or malignant seeding of the central nervous system.

Placement of an electrode array as a dural substitute for dorsal column stimulation: technical note.

One the drawbacks of the dorsal column stimulation (DCS) method is that the electrode array and the subsequent electrical stimulation induce proliferation of connective tissue between the array and the dura. In this case report, a patient is presented in whom dural thickening after placement of a DCS electrode array at the C2-C3 level prevented sufficient electrical penetration and thus resulted in treatment failure. The thickened dura was excised and the electronic array was used as a dural substitute. This resulted in efficient DCS and resolution of the pain symptoms.

Low frequency electrical stimulation through subdural electrodes in a case of refractory status epilepticus.

OBJECTIVE: We delivered low frequency stimulation through subdural electrodes to suppress seizures in a case of refractory status epilepticus (RSE). METHODS: A 26-year-old female developed RSE after several days of febrile illness. Seizure control required continuous infusion of two anesthetics plus high doses of 2-4 enteral antiepileptic drugs. After 3 months of RSE, subdural strips were placed to determine surgical candidacy. Five independent ictal onset zones were identified. Because she was a poor candidate for epilepsy surgery and had a poor prognosis, the implanted subdural electrodes were used to administer 0.5 Hz stimulations to the ictal onset zones in 30 min trains daily for 7 consecutive days in an attempt to suppress seizures. RESULTS: After 1 day of stimulation, one anesthetic agent was successfully discontinued. Seizures only returned by the 4th day when the second anesthetic had been reduced by 60%. Upon returning, seizures arose from only one of the 5 original ictal onset zones. Unfortunately, RSE persisted, and she eventually died. CONCLUSIONS: In this case of RSE, low frequency stimulation through subdural electrodes transiently suppressed seizures from all but one ictal onset zone and allowed significant reduction in seizure medication. SIGNIFICANCE: Low frequency cortical stimulation may be useful in suppressing seizures.

Single neuronal recordings using surface micromachined polysilicon microelectrodes.

Bulk micromachining techniques of silicon have been used successfully in the past several years to microfabricate microelectrodes for monitoring single neurons in acute and chronic experiments. In this study we report for the first time a novel surface micromachining technique to microfabricate a very thin polysilicon microelectrode that can be used for monitoring single-unit activity in the central nervous system. The microelectrodes are 3 mm long and 50 microm x 3.75 microm in cross-section. Excellent signal to noise ratios in the order of 25-35 dB were obtained while recording neuronal action potentials. The microelectrodes successfully penetrated the brains after a microincision of the dura mater. Chronic implantation of the microprobe for up to 33 days produced only minor gliosis. Since the polysilicon shank acts as a conductor, additional processing steps involved in laying conductor lines on silicon substrates are avoided. Further, surface micromachining allows for fabricating extremely thin microelectrodes which could result in decreased inflammatory responses. We conclude that the polysilicon microelectrode reported here could be a complementary approach to bulk-micromachined silicon microelectrodes for chronic monitoring of single neurons in the central nervous system.

Prevention of epidural fibrosis with ADCON-L in presence of a durotomy during lumbar disc surgery: experiences with a pre-clinical model.

A potential complication of lumbo-sacral surgery is the inadvertent tear of the dura mater, which sometimes eludes intra-operative detection. ADCON-L, a bioabsorbable gel used in lumbosacral laminectomies or laminotomies, is a physical barrier to post-operative epidural fibrosis. Three experimental lumbar laminectomy studies were designed to assess in vivo the effects of ADCON-L when applied in presence of dural punctures in a rat model. In the first study, the durotomy was repaired with fibrin sealant, in the second experiment the dural defect was microsurgically sutured, while in a third protocol the durotomy was left unrepaired. In each study, dural healing was assessed respectively at 4, 8, or 12 weeks post-operatively. Blinded anatomical dissection and histopathology were used to compare results between treatments (sham operated control vs. ADCON-L). In the fibrin sealant experiment, an additional treatment group (fibrin sealant used together with ADCON-L) was included. The results of these studies consistently demonstrate that ADCON-L is an effective anti-fibrotic agent, and does not interfere with the normal dural healing processes following a meningeal puncture. The application of the gel may therefore be safe in presence of dural incisions, even when they are not identified during surgery, as demonstrated in these in vivo studies.

Ampliaçäo vesical com dura-máter e pericárdio bovino: estudo comparativo em coelhos / Bladder augmentation with dura mater and bovine pericardium: comparative study in rabbits

Vários materiais aloplásicos têm sido preconizados na substituiçäo parcial da bexiga. Eles divergem em muitos aspectos, entre os quais o tempo adequado de reabsorçäo, a rejeiçäo, a formaçäo de cálculos, o tempo de reepitelizaçäo, a neoformaçäo de músculo e, o principal deles, a manutençäo das funçöes fisiológicas normais da bexiga, tais como: armazenamento com continência, esvaziamento adequado da urina e proteçäo aos rins. Com o objetivo de se avaliar, na bexiga, a repercussäo da cistoplastia com dura-máter e pericárdio bovino, estudaram-se, em 40 coelhos fêmeas, North Folk, com peso entre 1.350 e 4.500 g, os seguintes parâmetros: 1. cultura de urina; 2. estudo cistométrico; 3. uréia e creatinina plasmáticas. A pesquisa constou de quatro grupos experimentais, sendo cada um composto por dez coelhos, assim discriminados: G1 - Controle clínico, näo houve intervençäo cirúrgicas. G2 - Controle cirúrgico, realizamos cistectomia subtotal, e a porçäo excisada da bexiga era novamente anastomosada na regiäo trigonal. G3 - Dura-máter liofilizada, realizamos cistectomia subtotal e a parede vesical excisada era substituída por implante de dura-máter liofilizada de 3x1 cm. G4 - Pericárdio bovino, realizamos cistectomia subtotal e a parede vesical excisada era substituída por implante de pericárdio bovino de 3x1 cm. Os parâmetros foram estudados nos momentos: M1 - pré-operatório e M2 - doze semanas de pós-operatório. A avaliaçäoo cistomanométrica demonstrou näo haver diferenças significativas entre os diversos parâmetros, exceto uma tendência, em números absolutos, de reduçäo da capacidade vesical nos grupos 3 e 4. A complacência vesical ficou reduzida no grupo 4 nos diferentes momentos. Detectou-se 20 por cento de calculose vesical nos grupos 3 e 4. A análise físico-química do cálculo revelou composiçäo semelhante aos dois grupos

Dura mater substitutes in the surgical treatment of meningiomas.

Surgical resection of meningiomas may require removal of involved dura mater. Dural closure then requires the use of a dura mater substitute. Serious complications have been reported in patients with dural grafts. Understanding host-graft interaction and the potential for development of complications years after duraplasty aids in the delivery of comprehensive care to patients with in situ synthetic dura mater grafts.

[Autologous fibrin glue from preoperative blood or plasma donors]. / Autologer Fibrinkleber aus präoperativer Blutoder Plasmaspende.

Cryoprecipitate was prepared from autologous plasma donation (fresh frozen plasma). The composition of this cryoprecipitate (fibrinogen, factor XIII, fibronectin) meets the requirements for the fibrinogen component of a fibrin glue. The prepared glue has tensile strength values in dura mater gluing as good as the commercial tissue glues.

Dorsal column stimulation: optimization of application.

Although the basic efficacy of dorsal column stimulation (DCS) has been shown, its optimal use remains to be defined. Since 1970, a program designed to maximize clinical success with DCS has been under way at Temple University Health Sciences Center. This article reviews patients screening, operative technique, new instrumentation and postoperative adjustment in DCS. Clinical results and long-term impressions of 90 implants in 75 patients are reported.