Peri-medullary anterior spinal artery aneurysm associated with cervical pial arterio-venous fistula.

Spinal arteriovenous fistulas represent a heterogenous group of pathologies and are divided into four categories. Type IV fistulas are further stratified into three groups (IVa, IVb and IVc) according to the number and dimensions of the fistulous vessels. Approximately 10% of these fistulas are associated with aneurysms. However, we are not aware of a previously reported case of an aneurysm associated with a Type IVa fistula with an anterior spinal artery (ASA) feeder at the cervico-medullary junction. We therefore describe our experience with a patient presenting with a ruptured aneurysm associated with a fistula in this location.

The endoscopic transpterional port approach: anatomy, technique, and initial clinical experience.

OBJECTIVE: The evolution of microsurgical and endoscopic techniques has allowed the development of less invasive transcranial approaches. The authors describe a purely endoscopic transpterional port craniotomy to access lesions involving the cavernous sinus and the anterolateral skull base. METHODS: Through single- or dual-port incisions and with direct endoscopic visualization, the authors performed an endoscopic transpterional port approach (ETPA) using a 4-mm straight endoscope in 8 sides of 4 formalin-fixed cadaveric heads injected with colored latex. A main working port incision is made just below the superior temporal line and behind the hairline. An optional 0.5- to 1-cm second skin port incision is made on the lateral supraorbital region, allowing multiangle endoscopic visualization and maneuverability. A 1.5- to 2-cm craniotomy centered over the pterion is done through the main port, which allows an extradural exposure of the cavernous sinus region and extra/intradural exposure of the frontal and temporal cranial fossae. The authors present a pilot surgical series of 17 ETPA procedures and analyze the surgical indications and clinical outcomes retrospectively. RESULTS: The initial stage of this work on cadavers provided familiarity with the technique, standardized its steps, and showed its anatomical limits. The clinical ETPA was applied to gain access into the cavernous sinus, as well as for aneurysm clipping and meningioma resection. Overall, perioperative complications occurred in 1 patient (6%), there was no mortality, and at last follow-up all patients had a modified Rankin Scale score of 0 or 1. CONCLUSIONS: The ETPA provides a less invasive, focused, and direct route to the cavernous sinus, and to the frontal and temporal cranial fossae, and it is feasible in clinical practice for selected indications with good results.

The Extended Lateral Supraorbital Approach and Extradural Anterior Clinoidectomy Through a Frontopterio-Orbital Window: Technical Note and Pilot Surgical Series.

BACKGROUND: Lateral approaches to treat anterior cranial fossa lesions have evolved since the first frontotemporal approach described by Dandy in 1918. We describe a less invasive approach to perform extradural anterior clinoidectomy through a lateral supraorbital (LSO) approach for anterior circulation aneurysms and anterolateral skull base lesions. METHODS: The extended LSO approach involves performing a standard lateral supraorbital craniotomy followed by drilling of the sphenoid wing and lateral wall of the orbit through the frontal bony opening of the LSO approach, without any temporal extension of the craniotomy. This creates a frontopterio-orbital window exposing the periorbita; superior, medial, and anterior aspect of the temporal dura mater; and superior orbital fissure. After unroofing the superior orbital fissure, the meningo-orbital fold is cut, and the temporal dura mater is peeled from the lateral wall of the cavernous sinus to expose the anterior clinoid process allowing a standard opening of the optic canal and anterior clinoidectomy. RESULTS: The extended LSO approach and extradural anterior clinoidectomy allowed access to 4 sphenoid wing/anterior clinoidal meningiomas, 5 anterior circulation aneurysms, 2 temporomesial lesions, and 1 orbital/cavernous sinus abscess. Postoperatively, 2 patients had transient hemiparesis, 2 patients had transient third nerve palsy, and 1 patient had minimal visual field deterioration. All patients had a modified Rankin Scale score ≤1 at 8-week follow-up. CONCLUSION: The extended LSO approach opens a new route (frontopterio-orbital window) to perform extradural anterior clinoidectomy safely and increases surgical exposure, angles, and operability of a less invasive keyhole craniotomy (LSO approach) to treat anterior cranial fossa lesions.

Safety, efficacy, and cost of surgery for patients with unruptured aneurysms deemed unsuitable for endovascular therapy.

BACKGROUND: Open surgery is a frequent option given to patients with unruptured intracranial aneurysms (UIAs) unsuitable for endovascular repair. Since the risk of rupture of UIAs is generally low, we determined whether the risks and costs of surgery in this patient subset are warranted. METHODS: The safety, efficacy, and costs of minimally invasive surgery by minicraniotomy were evaluated in 102 consecutive patients with anterior circulation UIAs deemed unsuitable for endovascular repair by an interdisciplinary conference of surgeons and neurointerventionalists. Data from 107 UIA patients treated by endovascular means in the same period were used as the standard. RESULTS: Surgical patients comprised a different subset of aneurysms, with more MCA and fewer paraophthalmic aneurysms (54 vs. 6, p < 0.0001 and 4 vs. 60, p < 0.0001, for minicraniotomy and endovascular, respectively). However, surgery incurred shorter anesthesia time (197.7 vs. 149.3 min, p < 0.0001), higher rates of complete aneurysm obliteration (94.57 vs. 66.67 %, p < 0.0001), and lower overall hospital costs ($8,287 CAD vs. $17,732 CAD, p < 0.0001) than the endovascular cohort. There were no treatment-related surgical deaths, but one patient had an mRS of 3 after 6 months due to temporal lobe epilepsy and memory problems. This compared favorably with the endovascular cohort in which two patients died due to treatment (mRS = 6) and one suffered a severe stroke (mRS = 5 at 6 months). CONCLUSIONS: For patients counseled to undergo treatment but have UIAs unsuitable for endovascular repair, surgery is safe, effective, and cost-efficient.