Microsurgical repair by autografting in traumatic injuries of peripheral nerves.

BACKGROUND: Peripheral nerve injuries (PNI) with traumatic origin in upper and lower extremities are pathologies with an important quality-of-life considerations. For neurosurgeons, it is mandatory to understand their physiopathological mechanism and a proper treatment. The authors describe a series of 50 patients with traumatic PNI who underwent microsurgical reconstruction by autologous graft between 1993 and 2014. METHODS: Patients aged less than 65, who had neurological deficit in a range 3-12 months and severe and persistent nerve injury at electrophysiological examination were included in the study. After grafting, the overall functional recovery of the neurological deficit, the main prognostic factors (age, injured nerve, damage mechanism, gap length and surgical timing) and the postoperative functional outcome were analyzed. Neurological and electrophysiological follow-up was at 6-/12-/24-/48 months after surgery. RESULTS: The results showed that the best neurological recovery can be found in young patients with cut injuries of the upper limbs and that the outcome mainly depends on involved nerve, lesion type and minimum gap length. Moreover, follow-up for these pathologies should last till 48 months. CONCLUSIONS: In the future, these results could be further improved by the rising new techniques of nerve repair and the advances in neurobiology.

The Management of the Venous Sinuses During Surgery for Posterior Fossa Meningiomas.

OBJECTIVE: To define, from a series of surgically treated meningiomas of the posterior fossa with dural attachment above the dural sinuses, the best management of the sinus invasion according to the pattern of venous circulation. METHODS: Seventy-five patients with posterior fossa meningioma whose dural attachment involved the major venous sinuses were included in the study. We considered tumor location and dural attachment, pattern of venous sinus circulation, degree of sinus involvement and its management, entity of surgical resection, complications, and recurrences. RESULTS: The resection of the involved sinus segment (Simpson I) was performed in 15 patients (20%) (10 with complete occlusion and pattern of circulation of types A and B and 5 with narrowed sinus and type B circulation); 42 cases (56%, all of type 1) were treated by coagulation and/or removal of the outer dural layer (Simpson II). In 14 (19%) the intrasinusal fragment was left (Simpson III), and in 4 (5%) the resection was partial, with residual intradural tumor (Simpson IV). No postoperative complications secondary to venous obstruction occurred. Eleven patients (15%) experienced tumor recurrence and were reoperated on. Only 4 of them with extensive dural invasion had further recurrence. CONCLUSIONS: In patients with posterior fossa meningiomas, we suggest to safety resect the involved sinus segment only when completely occluded. If the sinus lumen is not invaded or the tumor lies on the side of the unique or dominant transverse sinus, it should be preserved. This results in no or negligible risk of venous infarction and rather low recurrence rate.

Vascularized nerve grafts: an experimental study.

OBJECTIVE: The aim of this study is to define an experimental model in order to promote the functional recovery of the nerves using grafts with vascular support (Vascular Nerve Grafts - VNG). The aim of this study is to define, on an experimental model in normal recipient bed, whether the functional recovery with VNG is superior to that obtained non-vascularized graft (NNG). METHODS: Twenty male rabbits, which underwent dissection of sciatic nerve, were later treated by reinnervation through an autograft. In 10 animals the reconstruction of sciatic nerve was realized with VNG; in 10 control animals the reconstruction of sciatic nerve was realized with NNG. RESULTS: The VNG group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (after 30 days) than the NNG group, whereas the difference in the axonal number at day 90 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by VNG group. DISCUSSION: Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.

Glioblastoma in the elderly: the impact of advanced age on treatment and survival.

OBJECTIVE: To evaluate the effects of combined treatments on the outcome and survival of elderly (≥ 65 years) patients with glioblastoma as compared with younger ones. MATERIAL AND METHODS: Fifty consecutive elderly (≥ 65 years) patients (group A) who underwent complete or subtotal (> 80%) resection of brain glioblastoma followed by irradiation and chemotherapy with temozolomide between 2004 and 2009 were retrospectively reviewed and compared with 50 glioblastoma patients aged < 65 years, treated in the same period (group B). Patient sex, tumor location, size and side, combined treatments, reoperation, progression-free survival, and overall survival were compared in the two groups by using the Kaplan-Meyer method. RESULTS: There were no significant differences between the two groups for tumor location, size and side, and Ki-67 Li. Forty-four of 50 group B patients were treated by the Stupp protocol, whereas all group A patients underwent irradiation and adjuvant temozolomide. Second-line chemotherapy was administrated in 32% of group A and 76% of group B cases, and reoperation was performed in 16% and 36%, respectively. The median survival of the overall series of 100 patients was 15.6 months. Group A patients (≥ 65 years) had a median survival of 14.5 months, significantly lower than group B cases (17 months) (p = 0.02). CONCLUSION: Elderly patients with glioblastoma may benefit from combined treatments, including surgery, radiotherapy, and chemotherapy. Although younger patients do survive longer than older ones, the difference of survival is less significant if several criteria of selection to surgery, such as good Karnofsky performance status (KPS), largely resectable tumor, and no significant comorbidity, are respected.

Role of extracellular matrix components in facial nerve regeneration: an experimental study.

OBJECTIVE: The aim of this study is to evaluate the role of extracellular matrix components in nerve regeneration. Matrigel, a complex of extracellular matrix components such as laminin (the most abundant) heparan sulphate proteoglycans (HSPG), type IV collagen and fibronectin, was used. METHODS: Forty male rabbits, which had undergone section of the right facial nerve, were later treated by reinnervation through an artificial graft of expanded polytetrafluoroethylene (ePTFE). In 20 animals the tubes of ePTFE were filled with Matrigel; in 20 control animals the tubes were filled with saline solution. RESULTS: The Matrigel group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (at days 15 and 30 respectively) than the control group, whereas the difference of the axons number at day 60 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by Matrigel. DISCUSSION: Our data suggest that Matrigel is an important factor in promoting and enhancing the early phases of the regeneration after nerve injuries. Tree neurite promoting agents, such as laminin, fibronectin and collagen, allow a more systematic and agonized regeneration. Extracellular matrix components may represent a direction guidance for axonal pathway.

One-stage removal of residual intracanalicular acoustic neuroma and hemihypoglossal-intratemporal facial nerve anastomosis: technical note.

OBJECTIVE AND IMPORTANCE: Incomplete removal of residual intracanalicular tumor and injury to the facial nerve are the main problems associated with surgery of large acoustic neuromas via the retromastoid suboccipital approach. In patients with residual or recurrent intracanalicular neuromas, the translabyrinthine approach is the preferred surgical route, allowing complete tumor removal; it may eventually also be used for exposure of the intratemporal portion of the facial nerve for a hemihypoglossal-facial nerve anastomosis when a postoperative facial palsy exists This one-stage procedure has not been described previously. CLINICAL PRESENTATION: Three patients with postoperative facial palsy and residual intracanalicular tumor after surgical removal of a large acoustic neuroma via the retromastoid suboccipital approach underwent reoperation via the translabyrinthine approach and one-stage removal of the residual tumor and hemihypoglossal-facial nerve anastomosis. All three patients had a complete facial palsy of House-Brackmann Grade VI and a residual tumor of 8 to 12 mm. TECHNIQUE: A classic translabyrinthine approach was used to open the internal auditory canal and remove the residual intracanalicular tumor. The facial nerve was exposed in its mastoid and tympanic parts, mobilized, and transected; then, the long nerve stump was transposed into the neck and used for an end-to-side anastomosis into the hypoglossal nerve. The operation resulted in variable improvement of the facial muscle function up to Grade III (one patient) and Grade IV (two patients). CONCLUSION: Reoperation via the translabyrinthine approach is indicated for removal of residual intracanalicular acoustic neuroma and realization of a hypoglossal-facial nerve anastomosis in a single procedure. It is suggested that this type of anastomosis may also be used during the initial operation for acoustic neuroma removal when the facial nerve is inadvertently sectioned.