Endoscopic odontoidectomy for brainstem compression in association with posterior fossa decompression and occipitocervical fusion

J Neurosurg 139:1152–1159, 2023

Endonasal endoscopic odontoidectomy (EEO) is an alternative to transoral surgery for symptomatic ventral compression of the anterior cervicomedullary junction (CMJ), allowing for earlier extubation and feeding. Because the procedure destabilizes the C1–2 ligamentous complex, posterior cervical fusion is often performed concomitantly. The authors’ institutional experience was reviewed to describe the indications, outcomes, and complications in a large series of EEO surgical procedures in which EEO was combined with posterior decompression and fusion.

METHODS A consecutive, prospective series of patients who underwent EEO between 2011 and 2021 was studied. Demographic and outcome metrics, radiographic parameters, extent of ventral compression, extent of dens removal, and increase in CSF space ventral to the brainstem were measured on the preoperative and postoperative scans (first and most recent scans).

RESULTS Forty-two patients (26.2% pediatric) underwent EEO: 78.6% had basilar invagination, and 76.2% had Chiari type I malformation. The mean ± SD age was 33.6 ± 3.0 years, with a mean follow-up of 32.3 ± 4.0 months. The majority of patients (95.2%) underwent posterior decompression and fusion immediately before EEO. Two patients underwent prior fusion. There were 7 intraoperative CSF leaks but no postoperative CSF leaks. The inferior limit of decompression fell between the nasoaxial and rhinopalatine lines. The mean ± SD vertical height of dens resection was 11.98 ± 0.45 mm, equivalent to a mean ± SD resection of 74.18% ± 2.56%. The mean increase in ventral CSF space immediately postoperatively was 1.68 ± 0.17 mm (p < 0.0001), which increased to 2.75 ± 0.23 mm (p < 0.0001) at the most recent follow-up (p < 0.0001). The median (range) length of stay was 5 (2–33) days. The median time to extubation was 0 (0–3) days. The median time to oral feeding (defined as, at minimum, toleration of a clear liquid diet) was 1 (0–3) day. Symptoms improved in 97.6% of patients. Complications were rare and mostly associated with the cervical fusion portion of the combined surgical procedures.

CONCLUSIONS EEO is safe and effective for achieving anterior CMJ decompression and is often accompanied by posterior cervical stabilization. Ventral decompression improves over time. EEO should be considered for patients with appropriate indications.

Endoscopic odontoidectomy for brainstem compression in association with posterior fossa decompression and occipitocervical fusion

J Neurosurg 139:1152–1159, 2023

Endonasal endoscopic odontoidectomy (EEO) is an alternative to transoral surgery for symptomatic ventral compression of the anterior cervicomedullary junction (CMJ), allowing for earlier extubation and feeding. Because the procedure destabilizes the C1–2 ligamentous complex, posterior cervical fusion is often performed concomitantly. The authors’ institutional experience was reviewed to describe the indications, outcomes, and complications in a large series of EEO surgical procedures in which EEO was combined with posterior decompression and fusion.

METHODS A consecutive, prospective series of patients who underwent EEO between 2011 and 2021 was studied. Demographic and outcome metrics, radiographic parameters, extent of ventral compression, extent of dens removal, and increase in CSF space ventral to the brainstem were measured on the preoperative and postoperative scans (first and most recent scans).

RESULTS Forty-two patients (26.2% pediatric) underwent EEO: 78.6% had basilar invagination, and 76.2% had Chiari type I malformation. The mean ± SD age was 33.6 ± 3.0 years, with a mean follow-up of 32.3 ± 4.0 months. The majority of patients (95.2%) underwent posterior decompression and fusion immediately before EEO. Two patients underwent prior fusion. There were 7 intraoperative CSF leaks but no postoperative CSF leaks. The inferior limit of decompression fell between the nasoaxial and rhinopalatine lines. The mean ± SD vertical height of dens resection was 11.98 ± 0.45 mm, equivalent to a mean ± SD resection of 74.18% ± 2.56%. The mean increase in ventral CSF space immediately postoperatively was 1.68 ± 0.17 mm (p < 0.0001), which increased to 2.75 ± 0.23 mm (p < 0.0001) at the most recent follow-up (p < 0.0001). The median (range) length of stay was 5 (2–33) days. The median time to extubation was 0 (0–3) days. The median time to oral feeding (defined as, at minimum, toleration of a clear liquid diet) was 1 (0–3) day. Symptoms improved in 97.6% of patients. Complications were rare and mostly associated with the cervical fusion portion of the combined surgical procedures.

CONCLUSIONS EEO is safe and effective for achieving anterior CMJ decompression and is often accompanied by posterior cervical stabilization. Ventral decompression improves over time. EEO should be considered for patients with appropriate indications.

Transuncal Selective Amygdalohippocampectomy by an Inferolateral Preseptal Endoscopic Approach Through Inferior Eyelid Conjunctival Incision: An Anatomic Study

Operative Neurosurgery 25:199–208, 2023

Transorbital endoscopic approaches have been described for pathologies of anterior and middle fossae. Standard lateral orbitotomy gives access to mesial temporal lobe, but the axis of work is partially obscured by the temporal pole and working corridor is limited.

OBJECTIVE: To evaluate the usefulness of an inferolateral orbitotomy to provide a more direct corridor to perform a transuncal selective amygdalohippocampectomy.

METHODS: Three adult cadaveric specimens were used for a total of 6 dissections. A step-by-step description and illustration of the transuncal corridor for a selective amygdalohippocampectomy were performed using the inferolateral orbitotomy through an inferior eyelid conjunctival incision. The anatomic landmarks were demonstrated in detail. Orbitotomies and angles of work were measured from computed tomography scans, and the area of resection was illustrated by postdissection MRI.

RESULTS: Inferior eyelid conjunctival incision was made for exposure of the inferior orbital rim. Inferolateral transorbital approach was performed to access the transuncal corridor. Endoscopic selective amygdalohippocampectomy was performed through the entorhinal cortex without damage to the temporal neocortex or Meyer’s loop. The mean horizontal diameter of the osteotomy was 14.4 mm, and the vertical one was 13.6 mm. The mean angles of work were 65°and 35.5°in the axial and sagittal planes, respectively. Complete amygdalohippocampectomy was achieved in all 6 dissections.

CONCLUSION: Transuncal selective amygdalohippocampectomy was feasible in cadaveric specimens using the inferolateral transorbital endoscopic approach avoiding damage to the temporal neocortex and Meyer’s loop. The inferior eyelid conjunctival incision may result in an excellent cosmetic outcome.

Endoscopic clipping of an anterior communicating artery aneurysm

Acta Neurochirurgica (2023) 165:1227–1231

Anterior communicating artery aneurysms are most prone to rupture. Surgically, they are conventionally being managed by a pterional approach. Some neurosurgeons prefer a supraorbital keyhole approach in select cases. Fully endoscopic clipping of such aneurysms is seldom described.

Method We clipped an antero-inferiorly directed anterior communicating artery aneurysm endoscopically via a supraorbital keyhole approach. The intraoperative aneurysmal rupture was also managed endoscopically. The patient made an excellent postoperative recovery without any neurological deficits.

Conclusion Select cases of anterior communicating artery aneurysms can be clipped endoscopically using standard instruments and adhering to the basic principles of aneurysm clipping.

Expanded endoscopic endonasal approach for the resection of midline craniopharyngiomas with hypothalamic involvement

Acta Neurochirurgica (2022) 164:3291–3296

With relevant surrounding neurological structures and potential involvement of the hypothalamus, the surgical management of craniopharyngiomas is complex. Compared to the transcranial approach, the expanded endoscopic endonasal approach provides direct access to the supradiaphragmatic and retrochiasmatic areas without crossing nerves and arteries.

Method Based on our substantial experience of 68 patients operated on between 2008 and 2022 by endoscopic surgery, our strategy has evolved such that all of our midline infundibular craniopharyngiomas with hypothalamic involvement are currently treated with an expanded endonasal route, except for tumours isolated to the third ventricle. Vascularized mucosal nasoseptal flaps are required for closure. Fine details of the related anatomy and surgical technique are described.

Conclusion Expanded endoscopic endonasal approach is a safe and effective route for resection of midline suprasellar craniopharyngiomas with hypothalamic involvement in centres of expertise.

Efficacy and safety of the endoscopic “wet‑field” technique for removal of supratentorial cavernous malformations

Acta Neurochirurgica (2022) 164:2587–2594

Cerebral cavernous malformations (CMs) presenting with focal neurological symptoms or mass effects require surgical removal. In recent years, cylindrical retractors have been widely utilized for the removal of deep-seated lesions during both microscopic and endoscopic surgery. In the present study, we evaluated the efficacy and safety of endoscopic transcylinder removal of CMs using a novel wet-field technique.

Methods We included 13 patients with supratentorial CMs who had undergone endoscopic transcylinder surgery between April 2013 and March 2022. One patient experienced recurrence of the CM and underwent a second endoscopic transcylinder surgery. Therefore, we retrospectively evaluated 14 procedures. The surgical field was continuously irrigated with artificial cerebrospinal fluid to maintain expansion and visualization of the tumor bed. We termed this method as the “wet-field technique.” Patient characteristics, symptoms, and pre- and postoperative magnetic resonance imaging results were obtained from medical records.

Results The average maximum CM diameter was 35.3 mm (range: 10–65 mm). Cylinder diameters were 6 mm in eight procedures, 10 mm in four procedures, and 17 mm in one procedure. Wet-field technique was applied in all cases. The endoscope provided a bright field of view even under water. Continuous water irrigation made it easier to observe the entire tumor bed which naturally expanded by water pressure. Gross total resection was achieved in 13 procedures, while subtotal resection was achieved in one procedure. No surgical complications were observed.

Conclusions The endoscopic transcylinder removal using wet-field technique is safe and effective for the removal of symptomatic intracranial supratentorial CMs.

Transseptal interforniceal endoscopic removal of superiorly recessed colloid cysts

J Neurosurg 137:813–819, 2022

Transforaminal endoscopic colloid cyst resection is well described. However, some anatomical colloid cyst variants may warrant a modified approach. Rarely, colloid cysts separate the forniceal columns and grow superiorly within the leaflets of the septum pellucidum. Thus, the authors’ goal was to characterize the imaging features, clinical presentation, surgical strategy, and outcomes of patients with this superiorly recessed colloid cyst variant.

METHODS A retrospective evaluation of patients who underwent endoscopic resection of colloid cysts from 1999 to 2020 was performed. The patients were dichotomized depending on whether the cyst was located predominately below the forniceal columns or was superiorly recessed (forniceal column separation with variable intraseptal extension). This comparative cohort study focused on clinical presentation, imaging features, operative technique, and patient outcome.

RESULTS In total, 182 patients were identified. Seventeen patients had colloid cysts that were defined as superiorly recessed and underwent transseptal interforniceal removal, and 165 patients underwent a standard transforaminal approach. Patients had similar demographic characteristics. However, transseptal cysts were on average larger (17.8 mm vs 11.4 mm, p < 0.0001), and these patients had a greater frontal-occipital horn ratio (0.45 vs 0.41, p = 0.012). They were also more likely to have undergone a previous resection (p = 0.02). The two cohorts had similar surgical outcomes, with no differences in extent of resection, recurrence, or complications.

CONCLUSIONS Superiorly recessed intraseptal colloid cysts are larger and tend to splay the bodies of the fornix, thus requiring a parasagittal transseptal interforniceal endoscopic approach. This achieves complete removal with comparatively negligible morbidity or rare recurrence (5.9%).

Unilateral approach with two‑cage insertion for full endoscopic transforaminal lumbar interbody fusion: technical report

Acta Neurochirurgica (2022) 164:1521–1527

The advantages of performing a transforaminal lumbar interbody fusion (TLIF) with two cages rather than a single cage include a larger cage-bone contact area and higher interbody stability.

Methods A customized cage guide is docked in the disc space created after a total facet resection. The first cage is inserted deeply into the contralateral disc space. The second cage is then inserted using the cage guide device while protecting the exiting and traversing nerve roots.

Conclusion We successfully inserted two cages from unilateral side during full endoscopic TLIF. This technique is recommended for L4–L5 and L5–S1 levels.

Double pedicled nasoseptal flap for skull base repair after endoscopic expanded endonasal approach

Acta Neurochirurgica (2022) 164:1111–1114

Expanded endonasal approach offers a spectacular corridor for skull base tumour resection but requires reliable multilayer reconstruction techniques with a vascularized nasoseptal flap.

Method On the basis on our substantial experience of 136 patients operated on between January 2008 and January 2020, the double pedicled nasoseptal flap technique was developed for skull base repair. The technique is finely detailed. The nasal floor mucosa was preserved. CSF leakage occurred in 4% of patients.

Conclusion Double pedicled nasoseptal flap is a reproducible and efficient technique for skull base reconstruction after expanded endonasal approach and is associated with limited rhinological complications.

A novel endoscope-assisted technique for lateral lumbar interbody fusion

J Neurosurg Spine 35:292–298, 2021

The lateral approach to the spine is generally well tolerated, but reports of debilitating injury to the lumbar plexus, iliac vessels, ureter, and abdominal viscera are increasingly recognized, likely related to the lack of direct visualization of these nearby structures. To minimize this complication profile, the authors describe here a novel, minimally invasive, endoscope-assisted technique for the LLIF and evaluate its clinical feasibility.

Seven consecutive endoscope-assisted lateral lumbar interbody fusion (LLIF) procedures by the senior authors were reviewed for the incidence of approachrelated complications. One patient had a postoperative approach-related complication. This patient developed transient ipsilateral thigh hip flexion weakness that resolved spontaneously by the 3-month follow-up. No patient experienced visceral, urological, or vascular injury, and no patient sustained a permanent neurological injury related to the procedure.

The authors’ preliminary experience suggests that this endoscope-assisted LLIF technique may be clinically feasible to mitigate vascular, urological, and visceral injury, especially in patients with previous abdominal surgery, anomalous anatomy, and revision operations. It provides direct visualization of at-risk structures without significant additional operative time. A larger series is needed to determine whether it reduces the incidence of lumbar plexopathy or visceral injury compared with traditional lateral approaches.

Modified far lateral endoscopic transforaminal lumbar interbody fusion using a biportal endoscopic approach

Acta Neurochirurgica (2021) 163:1205–1209

Endoscopic transforaminal lumbar interbody fusion (TLIF) has the disadvantage of the small cage size and by consequence risk for cage subsidence. We succeeded to insert a large oblique lumbar interbody fusion (OLIF) cage during biportal endoscopic TLIF.

Methods Unilateral total facetectomy was performed to expose the exiting and traversing nerve roots. The distance between the exiting and traversing nerve roots was measured before OLIF cage insertion. We inserted an OLIF cage instead of a TLIF cage.

Conclusion We successfully performed modified far lateral biportal endoscopic TLIF using large OLIF cages. Modified far lateral biportal endoscopic TLIF is usually suitable for the L4-5 and L5-S1 levels.

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

J Neurosurg 132:884–894, 2020

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.

Outcomes of endoscopic discectomy compared with open microdiscectomy and tubular microdiscectomy for lumbar disc herniations: a meta-analysis

J Neurosurg Spine 31:802–815, 2019

Endoscopic discectomy (ED) has been advocated as a less-invasive alternative to open microdiscectomy (OM) and tubular microdiscectomy (TM) for lumbar disc herniations, with the potential to decrease postoperative pain and shorten recovery times. Large-scale, objective comparisons of outcomes between ED, OM, and TM, however, are lacking. The authors’ objective in this study was to conduct a meta-analysis comparing outcomes of ED, OM, and TM.

METHODS The PubMed database was searched for articles published as of February 1, 2019, for comparative studies reporting outcomes of some combination of ED, OM, and TM. A meta-analysis of outcome parameters was performed assuming random effects.

RESULTS Twenty-six studies describing the outcomes of 2577 patients were included. Estimated blood loss was significantly higher with OM than with both TM (p = 0.01) and ED (p < 0.00001). Length of stay was significantly longer with OM than with ED (p < 0.00001). Return to work time was significantly longer in OM than with ED (p = 0.001). Postoperative leg (p = 0.02) and back (p = 0.01) VAS scores, and Oswestry Disability Index scores (p = 0.006) at latest follow-up were significantly higher for OM than for ED. Serum creatine phosphokinase (p = 0.02) and C-reactive protein (p < 0.00001) levels on postoperative day 1 were significantly higher with OM than with ED.

CONCLUSIONS Outcomes of TM and OM for lumbar disc herniations are largely equivalent. While this analysis demonstrated that several clinical variables were significantly improved in patients undergoing ED when compared with OM, the magnitude of many of these differences was small and of uncertain clinical relevance, and several of the included studies were retrospective and subject to a high risk of bias. Further high-quality prospective studies are needed before definitive conclusions can be drawn regarding the comparative efficacy of the various surgical treatments for lumbar disc herniations.

 

Complications associated with microscopic and endoscopic transsphenoidal pituitary surgery: experience of 1153 consecutive cases treated at a single tertiary care pituitary center

J Neurosurg 130:1576–1583, 2019

Pituitary adenomas (PAs) are benign neoplasms that are frequently encountered during workup for endocrinopathy, headache, or visual loss. Transsphenoidal surgery remains the first-line approach for PA resection. The authors retrospectively assessed complication rates associated with transsphenoidal PA resection from an institutional database.

METHODS A retrospective analysis of 1153 consecutive transsphenoidal pituitary adenoma resections performed at the Keck Hospital of USC between November 1992 and March 2017 was conducted. Microscopic transsphenoidal resection was performed in 85.3% of cases, and endoscopic transsphenoidal resection was performed in 14.7%. Analysis of perioperative complications and patient and tumor risk factors was conducted.

RESULTS The overall median hospital stay was 3 days. There was 1 perioperative death (0.1%). Surgical complications included postoperative cerebrospinal fluid leak (2.6%), epistaxis (1.1%), postoperative hematoma (1.1%), meningitis (1.0%), cranial nerve paresis (0.8%), hydrocephalus (0.8%), vision loss (0.6%), stroke (0.3%), abdominal hematoma or infection (0.2%), carotid artery injury (0.1%), and vegetative state (0.2%). Perioperative medical complications included bacteremia/sepsis (0.5%), pneumonia (0.3%), myocardial infarction (0.3%), and deep venous thrombosis/pulmonary embolism (0.1%). Endocrine complications were the most frequent, including transient diabetes insipidus (4.3%), symptomatic hyponatremia (4.2%), new hypopituitarism (any axis) (3.6%), permanent diabetes insipidus (0.3%), and adrenal insufficiency (0.2%). There were no significant differences between microscopic and endoscopic approaches with regard to surgical complications (6.4% vs 8.8%, p = 0.247) or endocrine complications (11.4 vs 11.8%, p = 0.888). Risk factors for surgical complications included prior transsphenoidal surgery (11.4% vs 6.8%, p = 0.025), preoperative vision loss (10.3% vs 6.8%, p = 0.002), and presence of PA invasion on MRI (8.5% vs 4.4%, p = 0.007).

CONCLUSIONS In this single tertiary center study assessing complications associated with transsphenoidal PA resection, the rate of death or major disability was 0.26%. Risk factors for complications included prior surgical treatment and PA invasion. No differences in complication rates between endoscopic and microscopic surgery were observed. When performed at experienced pituitary centers, transsphenoidal surgery for PAs may be performed with a high degree of safety.

 

Surgical resection of skull-base chordomas: experience in case selection for surgical approach according to anatomical compartments and review of the literature

Acta Neurochir (2017) 159:1835–1845

Chordoma is a rare bony malignancy known to have a high rate of local recurrence after surgery. The best treatment paradigm is still being evaluated. We report our experience and review the literature. We emphasize on the difference between endoscopic and open craniotomy in regard to the anatomical compartment harboring the tumor, the limitations of the approaches and the rate of surgical resection.

Method: We retrospectively collected all patients with skullbase chordomas operated on between 2004 and 2014. Detailed radiological description of the compartments being occupied by the tumor and the degree of surgical resection is discussed.

Results: Eighteen patients were operated on in our facility for skull-base chordoma. Seventeen endoscopic surgeries were done in 15 patients, and 7 craniotomies were done in 5 patients. The mean age was 48.9 years (±19.8 years). When reviewing the anatomical compartments, we found that the most common were the upper clivus (95.6%) and lower clivus (58.3%), left cavernous sinus (66.7%) and petrous apex (∼60%). Most of the patients had intradural tumor involvement (70.8%). In all craniotomy cases, there was residual tumor in multiple compartments. In the endoscopic cases, the most difficult compartments for total resection were the lower clivus, and lateral extensions to the petrous apex or cavernous sinus.

Conclusions: Our experience shows that the endoscopic approach is a good option for midline tumors without significant lateral extension. In cases with very lateral or lower extensions, additional approaches should be added trying to achieve complete resection.

Image-guided endoscopic surgery for spontaneous supratentorial intracerebral hematoma

J Neurosurg 127:537–542, 2017

Endoscopic removal of intracerebral hematomas is becoming increasingly common, but there is no standard technique. The authors explored the use of a simple image-guided endoscopic method for removal of spontaneous supratentorial hematomas.

METHODS Virtual reality technology based on a hospital picture archiving and communications systems (PACS) was used in 3D hematoma visualization and surgical planning. Augmented reality based on an Android smartphone app, Sina neurosurgical assist, allowed a projection of the hematoma to be seen on the patient’s scalp to facilitate selection of the best trajectory to the center of the hematoma. A obturator and transparent sheath were used to establish a working channel, and an endoscope and a metal suction apparatus were used to remove the hematoma.

RESULTS A total of 25 patients were included in the study, including 18 with putamen hemorrhages and 7 with lobar cerebral hemorrhages. Virtual reality combined with augmented reality helped in achieving the desired position with the obturator and sheath. The median time from the initial surgical incision to completion of closure was 50 minutes (range 40–70 minutes). The actual endoscopic operating time was 30 (range 15–50) minutes. The median blood loss was 80 (range 40–150) ml. No patient experienced postoperative rebleeding. The average hematoma evacuation rate was 97%. The mean (± SD) preoperative Glasgow Coma Scale (GCS) score was 6.7 ± 3.2; 1 week after hematoma evacuation the mean GCS score had improved to 11.9 ± 3.1 (p < 0.01).

CONCLUSIONS Virtual reality using hospital PACS and augmented reality with a smartphone app helped precisely localize hematomas and plan the appropriate endoscopic approach. A transparent sheath helped establish a surgical channel, and an endoscope enabled observation of the hematoma’s location to achieve satisfactory hematoma removal.

The expanded trans/supraorbital approach for large space-occupying lesions of the anterior fossa

Acta Neurochir (2017) 159:881–887

The supraorbital rim often interferes with the required upward movement of the instruments for resection of large frontal-lobe tumours through a classic supraorbital craniotomy. Here, we present the expanded trans/supraorbital approach to overcome these limitations.

Methods After an eyebrow skin incision, a one-piece bone flap was created incorporating the orbital rim and roof. Basal extension of the craniotomy allowed for a better intracranial visualisation with improved manoeuvrability and angulation of the instruments without using brain retraction.

Conclusions This approach poses a feasible alternative to large frontal craniotomies for frontal-lobe tumours, for which a regular supraorbital craniotomy is insufficient.

The mononostril endonasal transethmoidal-paraseptal approach

Acta Neurochir (2017) 159:453–457

The use of endoscopes in transnasal surgery offers increased visualization. To minimize rhinological morbidity without restriction in manipulation, we introduced the mononostril transethmoidal-paraseptal approach.

Methods The aim of the transethmoidal-paraseptal approach is to create sufficient space within the nasal cavity, without removal of nasal turbinates and septum. Therefore, as a first step, a partial ethmoidectomy is performed. The middle and superior turbinates are then lateralized into the ethmoidal space, allowing a wide sphenoidotomy with exposure of the central skull base.

Conclusions This minimally invasive transethmoidal-paraseptal approach is a feasible alternative to traumatic transnasal concepts with middle turbinate and extended septal resection.

Endoscopic third ventriculostomy for treatment of adult hydrocephalus: long-term follow-up of 163 patients

ETV

Neurosurg Focus 41 (3):E3, 2016

The authors performed a retrospective chart review of all adult patients (age ≥ 18 years) with symptomatic hydrocephalus treated with ETV in Calgary, Canada, over a span of 20 years (1994–2014). Patients were dichotomized into a primary or secondary ETV cohort based on whether ETV was the initial treatment modality for the hydrocephalus or if other CSF diversion procedures had been previously attempted respectively. Primary outcomes were subjective patient-reported clinical improvement within 12 weeks of surgery and the need for any CSF diversion procedures after the initial ETV during the span of the study. Categorical and actuarial data analysis was done to compare the outcomes of the primary versus secondary ETV cohorts.

Results A total of 163 adult patients with symptomatic hydrocephalus treated with ETV were identified and followed over an average of 98.6 months (range 0.1–230.4 months). All patients presented with signs of intracranial hypertension or other neurological symptoms. The primary ETV group consisted of 112 patients, and the secondary ETV consisted of 51 patients who presented with failed ventriculoperitoneal (VP) shunts. After the initial ETV procedure, clinical improvement was reported more frequently by patients in the primary cohort (87%) relative to those in the secondary ETV cohort (65%, p = 0.001). Additionally, patients in the primary ETV group required fewer reoperations (p < 0.001), with cumulative ETV survival time favoring this primary ETV cohort over the course of the follow-up period (p < 0.001). Fifteen patients required repeat ETV, with all but one experiencing successful relief of symptoms. Patients in the secondary ETV cohort also had a higher incidence of complications, with one occurring in 8 patients (16%) compared with 2 in the primary ETV group (2%; p = 0.010), although most complications were minor.

Conclusions ETV is an effective long-term treatment for selected adult patients with hydrocephalus. The overall ETV success rate when it was the primary treatment modality for adult hydrocephalus was approximately 87%, and 99% of patients experience symptomatic improvement after 2 ETVs. Patients in whom VP shunt surgery fails prior to an ETV have a 22% relative risk of ETV failure and an almost eightfold complication rate, although mostly minor, when compared with patients who undergo a primary ETV. Most ETV failures occur within the first 7 months of surgery in patients treated with primary ETV, but the time to failure is more prolonged in patients who present with failed previous shunts.

Endo ICG videoangiography: localizing the carotid artery in skull-base endonasal approaches

Endo ICG videoangiography- localizing the carotid artery in skull-base endonasal approaches

Acta Neurochir (2016) 158:1351–1353

In this work, the applicability of ICG-VA to skull base endoscopic surgery and its capacity to locate the internal carotid artery are shown.

Methods: An adapted optical module to perform ICG-VA was used to perform endoscopic procedures. There were two intraoperative phases of interest that were used to evaluate the ICA: upon exposure of the skull base and during the intradural exploration.

This new tool for obtaining ICA images in real time (as opposed to with navigation), and it is demonstrated that this tool provides a superior ability to detect the margins of the ICA compared with the Doppler technique. On the other hand, the present technique also provides enhancement of the artery through the bone of the skull base without the need for drilling.

Conclusions: ICG-VA is a safe and effective technique for locating the ICA in skull-base expanded endonasal surgery. Furthermore, this technique can provide real-time guidance for the surgeon and increase safety for the patient.