Category: Endoscopy

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Use of the NeuroBalloon catheter for endoscopic third ventriculostomy

endoscopic third ventriculostomy

J Neurosurg Pediatrics 11:302–306, 2013

Endoscopic third ventriculostomy (ETV) has become the procedure of choice for treatment of obstructive hydrocephalus.

While patient selection is the most critical factor in determining the success of an ETV procedure, the technical challenge lies in the proper site of fenestration and the successful creation of a patent stoma.

Positioning of a single balloon catheter at the level or below the floor of the third ventricle to achieve an optimal ventriculostomy can at times be challenging.

Here, the authors describe the use of a double-barrel balloon catheter (NeuroBalloon catheter), which facilitates positioning across, as well as dilation of, the floor of the third ventricle.

The surgical technique and nuances of using the NeuroBalloon catheter and the experience in more than 1000 cases are described. The occurrence of vascular injury was less than 0.1%, and the risk of balloon rupture was less than 2%.

The authors found that the placement and deployment of this balloon catheter facilitate the creation of an adequate ventriculostomy in a few simple steps.

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Endoscopic endonasal skull base surgery in the pediatric population

Epeds12160-1

J Neurosurg Pediatrics 11:227–241, 2013

The use of endoscopic endonasal surgery (EES) for skull base pathologies in the pediatric population presents unique challenges and has not been well described. The authors reviewed their experience with endoscopic endonasal approaches in pediatric skull base surgery to assess surgical outcomes and complications in the context of presenting patient demographics and pathologies.

Methods. A retrospective review of 133 pediatric patients who underwent EES at our institution from July 1999 to May 2011 was performed.

Results. A total of 171 EESs were performed for skull base tumors in 112 patients and bony lesions in 21. Eightyfive patients (63.9%) were male, and the mean age at the time of surgery was 12.7 years (range 2.3–18.0 years). Skull base tumors included angiofibromas (n = 24), craniopharyngiomas (n = 16), Rathke cleft cysts (n = 12), pituitary adenomas (n = 11), chordomas/chondrosarcomas (n = 10), dermoid/epidermoid tumors (n = 9), and 30 other pathologies. In total, 19 tumors were malignant (17.0%). Among patients with follow-up data, gross-total resection was achieved in 16 cases of angiofibromas (76.2%), 9 of craniopharyngiomas (56.2%), 8 of Rathke cleft cysts (72.7%), 7 of pituitary adenomas (70%), 5 of chordomas/chondrosarcomas (50%), 6 of dermoid/epidermoid tumors (85.7%), and 9 cases of other pathologies (31%). Fourteen patients received adjuvant radiotherapy, and 5 received chemotherapy. Sixteen patients (15.4%) showed tumor recurrence and underwent reoperation. Bony abnormalities included skull base defects (n = 12), basilar invagination (n = 4), optic nerve compression (n = 3) and trauma (n = 2); preexisting neurological dysfunction resolved in 12 patients (57.1%), improved in 7 (33.3%), and remained unchanged in 2 (9.5%). Overall, complications included CSF leak in 14 cases (10.5%), meningitis in 5 (3.8%), transient diabetes insipidus in 8 patients (6.0%), and permanent diabetes insipidus in 12 (9.0%). Five patients (3.8%) had transient and 3 (2.3%) had permanent cranial nerve palsies. The mean follow-up time was 22.7 months (range 1–122 months); 5 patients were lost to follow-up.

Conclusions. Endoscopic endonasal surgery has proved to be a safe and feasible approach for the management of a variety of pediatric skull base pathologies. When appropriately indicated, EES may achieve optimal outcomes in the pediatric population

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Endoscopic Transsphenoidal Surgery for Cushing Disease

Endoscopic for Cushing Disease

Neurosurgery 72:240–247, 2013

The efficacy of endoscopic transsphenoidal surgery (ETS) for Cushing disease has not been clearly established.

OBJECTIVE: To assess efficacy of a pure endoscopic approach for treatment of Cushing disease and determine predictors of remission.

METHODS: A prospectively acquired database of 61 patients undergoing ETS was reviewed. Remission was defined as postoperative morning serum cortisol of ,5 mg/dL or normal or decreased 24-hour urine-free cortisol level in follow-up.

RESULTS: Overall, hypercortisolemia resolved in 58 of 61 patients (95%) by discharge. Tumor size did not predict resolution of hypercortisolemia at discharge (microadenomas [97%], magnetic resonance imaging-negative Cushing [100%], macroadenomas [87%]). At 2- to 3-month evaluations, 45 of 49 patients (91.8%) were in remission. Fifty patients were followed for at least 12 months (mean, 28 months; range, 12-72). Forty-two (84%) achieved remission from a single ETS. In these patients, there was no significant difference in remission rates between microadenomas (93%), magnetic resonance imaging-negative (70%), and macroadenomas (77%). Patients with history of previous surgery (n = 14, 23%) were 9 times less likely to achieve follow-up remission (P = .021). In-house cortisol level of ,5.7 mg/dL provided the best prediction of follow-up remission (sensitivity 88.6%, specificity 83.3%). Postoperative diabetes insipidus occurred transiently in 7 patients (9%) and permanently in 3 (5%). One patient experienced postoperative cerebrospinal fluid leak that resolved with further surgery.

CONCLUSION: ETS for Cushing disease provides high rates of remission with low rates of complications regardless of size. Although patients with a history of previous surgery are less likely to achieve remission, the majority can still achieve remission following treatment.

KEYWORDS:

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Transphenoidal surgery in acromegalic patients: anatomical considerations and potential pitfalls

Transphenoidal surgery in acromegalic patients- anatomical considerations and potential pitfalls.1 Transphenoidal surgery in acromegalic patients- anatomical considerations and potential pitfalls

Acta Neurochir (2013) 155:125–130

Transphenoidal surgery is an effective treatment for acromegalic patients with growth hormone (GH) producing pituitary adenomas. Since acromegaly is a systemic disease which causes multiple bony alterations, we hypothesized that it could affect the sphenoid sinus anatomy. The aim of the study was to determine whether acromegalic patients have sphenoid sinus alterations with potential surgical impact.

Methods Fourty-six consecutive patients (23 acromegalics- GH group, 23 non-acromegalics-nGH group) undergoing transphenoidal surgery were included in this study. Preoperative volumetric CT scan of the head was used to assess the following anatomic characteristics: type of sphenoid sinus (sellar, pre-sellar, conchal); number of intrasphenoid septa; number of carotid-directed septa; intercarotid distance; depth of the sphenoid sinus; depth and size of the sella.

Results The sphenoid sinus was of the pre-sellar/conchal type in 26 % of the patients with acromegaly (n023) versus 9 % of the patients of the nGH group (n023). The number of intrasphenoid septations was significantly higher in the GH group than in the nGH group (P=.03). Interestingly, the intercarotid distance was smaller in GH patients than in nGH displaying a trend toward significance (P=.05). The sphenoid bone was deeper in the GH group as compared to the nGH group (P=.01) but the distance sphenoid sinus-sella was reduced (P<.01). Finally, the sella was not deeper, nor larger in acromegalic patients.

Conclusions The sphenoid sinus of acromegalic patients resulted in being deeper, characterized by more septa and by a reduced intercarotid distance. These alterations deserve special pre- and intraoperative care, being potentially responsible for surgical difficulties.

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Endoscopic endonasal surgery for giant pituitary adenomas: advantages and limitations

Endoscopic endonasal surgery limitations

J Neurosurg / January 4, 2013. DOI: 10.3171/2012.11.JNS121190

Giant pituitary adenomas (> 4 cm in maximum diameter) represent a significant surgical challenge. Endoscopic endonasal surgery (EES) has recently been introduced as a treatment option for these tumors. The authors present the results of EES for giant adenomas and analyze the advantages and limitations of this technique.

Methods. The authors retrospectively reviewed the medical files and imaging studies of 54 patients with giant pituitary adenomas who underwent EES and studied the factors affecting surgical outcome.

Results. Preoperative visual impairment was present in 45 patients (83%) and partial or complete pituitary deficiency in 28 cases (52%), and 7 patients (13%) presented with apoplexy. Near-total resection (> 90%) was achieved in 36 patients (66.7%). Vision was improved or normalized in 36 cases (80%) and worsened in 2 cases due to apoplexy of residual tumor. Significant factors that limited the degree of resection were a multilobular configuration of the adenoma (p = 0.002) and extension to the middle fossa (p = 0.045). Cavernous sinus invasion, tumor size, and intraventricular or posterior fossa extension did not influence the surgical outcome. Complications included apoplexy of residual adenoma (3.7%), permanent diabetes insipidus (9.6%), new pituitary insufficiency (16.7%), and CSF leak (16.7%, which was reduced to 7.4% in recent years). Fourteen patients underwent radiation therapy after EES for residual mass or, in a later stage, for recurrence, and 10 with functional pituitary adenomas received medical treatment. During a mean follow-up of 37.9 months (range 1–114 months), 7 patients were reoperated on for tumor recurrence. Three patients were lost to follow-up.

Conclusions. Endoscopic endonasal surgery provides effective initial management of giant pituitary adenomas with favorable results compared with traditional microscopic transsphenoidal and transcranial approaches.

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The Naso-Axial Line: A New Method of Accurately Predicting the Inferior Limit of the Endoscopic Endonasal Approach to the Craniovertebral Junction

The Naso-Axial Line- A New Method of Accurately Predicting the Inferior Limit of the Endoscopic Endonasal Approach to the Craniovertebral Junction

Neurosurgery 71[ONS Suppl 2]:ons308–ons314, 2012

The endoscopic endonasal approach (EEA) has developed as an emerging surgical corridor to the craniovertebral junction (CVJ). In addition to understanding its indications and surgical anatomy, the ability to predict its inferior limit is vital for optimal surgical planning.

OBJECTIVE: To develop a method that accurately predicts the inferior limit of the EEA on the CVJ radiologically and to compare this with other currently used methods.

METHODS: Predissection computerized tomographic scans of 9 cadaver heads were used to delineate a novel line, the naso-axial line (NAxL), to predict the inferior EEA limit on the upper cervical spine. A previously described method with the use of the nasopalatine line (NPL or Kassam line) was also used. On computerized tomographic scans obtained following dissection of the EEA, the predicted inferior limits were compared with the actual extent of dissection.

RESULTS: The postdissection inferior EEA limit ranged from the dens tip to the upper half of the C2 body, which matched the limit predicted by NAxL, with no statistically significant difference between them. In contrast to the NAxL, the NPL predicted a significantly lower EEA limit (P , .001), ranging from the lower half of the C2 body to the superior end plate of C3.

CONCLUSION: The novel NAxL more accurately predicts the inferior limit of the EEA than the NPL. This method, which can be easily used on preoperative sagittal scans, accounts for variations in patients’ anatomy and can aid surgeons in the assessment of the EEA to address caudal CVJ pathology.

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Percutaneous endoscopic treatment of foraminal and extraforaminal disc herniation at the L5-S1 level

Acta Neurochir (2012) 154:1789–1795

Microsurgery of foraminal and extraforaminal disc herniation at the L5-S1 level remains a challenge because of the limited access by a high iliac crest, the sacral ala, large transverse processes of L5 and hidden disc fragments lateral to the zygapophyseal joint.

Our aim was to present the outcome of percutaneous endoscopic lumbar discectomy (PELD) of these lateral and far lateral disc herniations at the L5-S1 level using the newly described foraminal retreat technique in a group of patients with similar preoperative diagnostic studies.

Methods A total of 22 patients, 13 males and 9 females, with foraminal and extraforaminal lumbar disc herniation at the L5-S1 level were treated by applying the PELD between September 2004 and April 2010. The clinical findings and MRI were the main diagnostic methods. Preoperative evaluation was performed with clinical examinations, the Visual Analog Pain Scale (VAS) and Oswestry Low Back Disability Index (ODI).

Findings According to the Macnab criteria, overall excellent or good outcomes were obtained in 18 patients (81.8 %), fair outcomes in 3 patients (13.6 %) and a poor outcome in 1 patient (4.5 %) at the last follow-up. The mean ODI was 67.3±19.4 preoperatively and 26.7±23.4 postoperatively. Preoperative VAS was 88.6±7.6 and 28.6±22.8 at 2 days, 40.5±22.8 at 3 weeks, 34.3±25.1 at 6-months and 32 at the last follow-up. At follow-up, two patients (9.1 %) had recurrent disc herniations that were corrected with open surgery. At the time of surgery, 16 patients held jobs. Fifteen (15) patients (93.8 %) returned to their original jobs postoperatively; one patient could not return to his original job postoperatively because of a comorbidity.

Conclusions Percutaneous endoscopic discectomy using the foraminal retreat technique is an effective treatment method for patients with foraminal and extraforaminal disc herniations at the L5-S1 level on appropriately selected patients.

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Removal of an ICH through an eyebrow incision

J Neurosurg 117:767–773, 2012

Surgical evacuation of spontaneous intracerebral hemorrhage (sICH) remains a subject of controversy. Minimally invasive techniques for hematoma evacuation have shown a trend toward improved outcomes. The aim of the present study is to describe a minimally invasive alternative for the evacuation of sICH and evaluate its feasibility.
Methods
The authors reviewed records of all patients who underwent endoscopic evacuation of an sICH at the UCLA Medical Center between March 2002 and March 2011. All patients in whom the described technique was used for evacuation of an sICH were included in this series. In this approach an incision is made at the superior margin of the eyebrow, and a bur hole is made in the supraorbital bone lateral to the frontal sinus. Using stereotactic guidance, the surgeon advanced the endoscopic sheath along the long axis of the hematoma and fixed it in place at two specific depths where suction was then applied until 75%–85% of the preoperatively determined hematoma volume was removed. An endoscope’s camera, then introduced through the sheath, was used to assist in hemostasis. Preoperative and postoperative hematoma volumes and reduction in midline shift were calculated and recorded. Admission Glasgow Coma Scale and modified Rankin Scale (mRS) scores were compared with postoperative scores.
Results
Six patients underwent evacuation of an sICH using the eyebrow/bur hole technique. The mean preoperative hematoma volume was 68.9 ml (range 30.2–153.9 ml), whereas the mean postoperative residual hematoma volume was 11.9 ml (range 5.1–24.1 ml) (p = 0.02). The mean percentage of hematoma evacuated was 79.2% (range 49%–92.7%). The mean reduction in midline shift was 57.8% (p < 0.01). The Glasgow Coma Scale score improved in each patient between admission and discharge examination. In 5 of the 6 patients the mRS score improved from admission exam to last follow-up. None of the patients experienced rebleeding.
Conclusions
This minimally invasive technique is a feasible alternative to other means of evacuating sICHs. It is intended for anterior basal ganglia hematomas, which usually have an elongated, ovoid shape. The approach allows for an optimal trajectory to the long axis of the hematoma, making it possible to evacuate the vast majority of the clot with only one pass of the endoscopic sheath, theoretically minimizing the amount of damage to normal brain.

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Endoscopic Endonasal Transclival Approach to the Jugular Tubercle

Neurosurgery 71[ONS Suppl 1]:ons146–ons159, 2012

The jugular tubercle is a rounded bony prominence that arises from the inferolateral margin of the clivus. In a previous publication, we described the surgical anatomy of the expanded endonasal approach to the jugular tubercle.

OBJECTIVE: To illustrate the translation of laboratory work to the operating room describing the anatomic and technical nuances of the endonasal approach to the jugular tubercle.

METHODS: We review the relevant surgical anatomy needed to perform an endonasal approach to the jugular tubercle, and we select 4 different lesions to illustrate the application of our laboratory findings.

RESULTS: In the first case, exposure and partial drilling of the jugular tubercle was critical to gain an adequate corridor to the meningioma, particularly to its inferolateral margin. This allowed for early devascularization, safe extracapsular dissection, and preservation of surrounding neurovascular structures. In addition, the jugular tubercle was hyperostotic and its resection, along with generous dural removal, provided a grade I Simpson tumor resection. In the second (chondrosarcoma) and third (chordoma) cases, the jugular tubercle was infiltrated by tumor, and consequently its complete resection was essential to achieve total tumor removal. In the last case, an unusual adrenocorticotropic hormone-secreting adenoma recurrence at the jugular tubercle region, the technical modification of the transclival approach presented here was successfully applied to achieve complete resection and Cushing disease remission.

CONCLUSION: The transjugular tubercle variant of the expanded endonasal transclival approach allows for direct access to ventrolateral lesions in the inferior clival/petroclival region with no cerebral or cerebellar retraction, or cranial nerve manipulation during the approach.

 

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Efficacy and Safety of Endoscopic Transventricular Lamina Terminalis Fenestration for Hydrocephalus

Neurosurgery 71:464–473, 2012 DOI: 10.1227/NEU.0b013e31825b1e8d

Endoscopic third ventriculostomy (ETV) has become the procedure of choice in the treatment of obstructive hydrocephalus. In certain cases, standard ETV might not be technically possible or may engender significant risk.

OBJECTIVE: To present an alternative through the lamina terminalis (LT) by a transventricular, transforaminal approach with flexible neuroendoscopy and to discuss the indications, technique, neuroendoscopic findings, and outcomes.

METHODS: Between 1994 and 2010, all patients who underwent endoscopic LT fenestration as an alternative to ETV were analyzed and prospectively followed up. The decision to perform an LT fenestration was made intraoperatively.

RESULTS: Twenty-five patients, ranging in age from 7 months to 76 years (mean, 28.1 years), underwent endoscopic LT fenestration. Patients had obstructive hydrocephalus secondary to neurocysticercosis (11 patients), neoplasms (6 patients), congenital aqueductal stenosis (3 patients), and other (5 patients). Thirteen patients (52%) had had at least 1 ventriculoperitoneal shunt that malfunctioned; 6 patients (24%) had undergone a previous endoscopic procedure. Intraoperative findings that led to an LT fenestration were the following: ETV not feasible to perform, basal subarachnoid space not sufficient, or adhesions in the third ventricle. No perioperative complications occurred. The mean follow-up period was 63.76 months. Overall, 19 patients (76%) had resolutions of symptoms, had no evidence of ventriculomegaly, and did not require another procedure. Six (24%) required a ventriculoperitoneal shunt.

CONCLUSION: Endoscopic transventricular transforaminal LT fenestration with flexible neuroendoscopy is feasible with a low incidence of complications. It is a good alternative to standard ETV. Adequate intraoperative assessment of ETV success is necessary to identify patients who will benefit.

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Endoscopic indocyanine green video angiography in aneurysm surgery

J Neurosurg 117:302–308, 2012

Recently, intraoperative fluorescence video angiography using indocyanine green (ICG) has been widely used in aneurysm surgery. This is a simple and useful method to confirm complete occlusion of the aneurysm lumen and preservation of blood flow in the arteries around the aneurysm. However, the observation field of ICG video angiography is limited under a microscope, making it difficult to confirm the flow in the arteries behind the parent arteries or aneurysm.

The authors developed a new technique of intraoperative endoscopic ICG video angiography to assess the blood flow in perforating arteries hidden by the parent arteries or aneurysm. The endoscope emits excitation light with a wavelength of approximately 800 nm, and video images were obtained through a cut filter.

The authors used this ICG fluorescence endoscope in treating 3 patients with unruptured cerebral aneurysms. During clip placement, the endoscope was inserted to confirm aneurysm occlusion. Then, ICG was intravenously administered, and the fluorescence in the vessels was observed via the endoscope as well as under the microscope. The blood flow in the perforating arteries was clearly identified, and no procedural complication occurred.

The authors conclude that the technique is very useful and facilitates intraoperative real-time assessment of the patency of perforating arteries behind parent arteries or aneurysms.

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Why does endoscopic aqueductoplasty fail so frequently?

J Neurosurg 117:141–149, 2012

The aim of this study was to evaluate and compare CSF flow after endoscopic third ventriculostomy (ETV) and endoscopic aqueductoplasty (EAP) in patients presenting with obstructive hydrocephalus caused by aqueductal stenosis.

Methods. In patients harboring aqueductal stenosis who underwent EAP (n = 8), ETV (n = 8), and both ETV and EAP (n = 6), CSF flow through the restored aqueduct and through the ventriculostomy was investigated using cine cardiac-gated phase-contrast MRI. For qualitative evaluation of CSF flow, an in-plane phase-contrast sequence in the midsagittal plane was used. The MR images were displayed in a closed-loop cine format. Quantitative through-plane measurements were performed in the axial plane perpendicular to the aqueduct and/or floor of the third ventricle.

Results. Evaluation revealed significantly higher CSF flow through the ventriculostomies compared with flow through the aqueducts. This was true both when comparing the ETV group with the EAP group and when comparing the flow of the ventriculostomy and aqueduct within the ETV and EAP group. There was no difference in aqueductal CSF flow between patients who underwent EAP alone and patients who underwent ETV and EAP. There was also no difference in ventriculostomy CSF flow between patients who underwent ETV alone and patients who underwent ETV and EAP. Fifty percent of the restored aqueducts became occluded at a mean of 46 months after surgery (range 18–126 months). In contrast, all ETVs remained patent in the mean follow-up period of 110 months after surgery, although 1 patient required shunt placement after 66 months.

Conclusions. Cerebrospinal fluid flow through ventriculostomies is significantly higher than aqueductal CSF flow after EAP. This could be one factor to explain why the reclosure rate of aqueducts after EAP is higher than the reclosure rate of the ventriculostoma after ETV.

 

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Hyponatremia following endoscopic third ventriculostomy

Neurosurg Pediatrics 10:39–43, 2012. http://thejns.org/doi/abs/10.3171/2012.4.PEDS1222

Electrolyte and endocrinological complications of endoscopic third ventriculostomy (ETV) are infrequent but serious events, likely due to transient hypothalamic-pituitary dysfunction. While the incidence of diabetes insipidus is relatively well known, hyponatremia is not often reported. The authors report on a series of 5 patients with post-ETV hyponatremia.

Methods. The records of patients undergoing ETV between 2008 and 2010 were reviewed. All ETVs were performed with a rigid neuroendoscope via a frontal bur hole, standard third ventricle floor blunt perforation, Fogarty catheter dilation, and intermittent normal saline irrigation. Postoperative MR images were evaluated for endoscope tract injury as well as the trajectory from the bur hole center to the fenestration site.

Results. Thirty-two patients (20 male and 12 female) underwent ETV. Their median age was 6 years (range 3 weeks–28 years). Hydrocephalus was most commonly due to nontumoral aqueductal stenosis (43%), nontectal tumor (25%), or tectal glioma (13%). Five patients (16%) had multicystic/loculated hydrocephalus. Five patients (16%) developed hyponatremia between 1 and 8 days following ETV, including 2 patients with seizures (1 of whom was still hospitalized at the time of the seizure and 1 of whom was readmitted as a result of the seizure) and 3 patients who were readmitted because of decline in their condition following routine discharge. No hypothalamic injuries were noted on imaging. Univariate risk factors consisted of age of 2 years or less (p = 0.02), presence of cystic lesions (p = 0.02), and ETV trajectory angle 10° or more from perpendicular (p = 0.001).

Conclusions. Endoscopic third ventriculostomy is a well-tolerated procedure but can result in serious complications. Hyponatremia is rare and may be more likely in younger patients or those with cystic loculations. Patients with altered craniometry may be at particular risk with a rigid endoscopic approach requiring greater manipulation of subforniceal or hypothalamic structures.

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Surgical nuances for nasoseptal flap reconstruction of cranial base defects with high-flow cerebrospinal fluid leaks after endoscopic skull base surgery

Neurosurg Focus 32 (6):E7, 2012. DOI: 10.3171/2012.5.FOCUS1255

Extended endoscopic endonasal approaches have allowed for a minimally invasive solution for removal of a variety of ventral skull base lesions, including intradural tumors. Depending on the location of the pathological entity, various types of surgical corridors are used, such as transcribriform, transplanum transtuberculum, transsellar, transclival, and transodontoid approaches. Often, a large skull base dural defect with a high-flow CSF leak is created after endoscopic skull base surgery. Successful reconstruction of the cranial base defect is paramount to separate the intracranial contents from the paranasal sinus contents and to prevent postoperative CSF leakage. The vascularized pedicled nasoseptal flap (PNSF) has become the workhorse for cranial base reconstruction after endoscopic skull base surgery, dramatically reducing the rate of postoperative CSF leakage since its implementation.

In this report, the authors review the surgical technique and describe the operative nuances and lessons learned for successful multilayered PNSF reconstruction of cranial base defects with high-flow CSF leaks created after endoscopic skull base surgery. The authors specifically highlight important surgical pearls that are critical for successful PNSF reconstruction, including target-specific flap design and harvesting, pedicle preservation, preparation of bony defect and graft site to optimize flap adherence, multilayered closure technique, maximization of the reach of the flap, final flap positioning, and proper bolstering and buttressing of the PNSF to prevent flap dehiscence. Using this technique in 93 patients, the authors’ overall postoperative CSF leak rate was 3.2%.

An illustrative intraoperative video demonstrating the reconstruction technique is also presented.

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Endoscopy in Aneurysm Surgery

Neurosurgery 70[ONS Suppl 2]:ons184–ons191, 2012. DOI: 10.1227/NEU.0b013e3182376a36

Surgical clipping with complete occlusion of the aneurysm and preservation of parent, branching, and perforating vessels remains the most definitive treatment for intracranial aneurysms.

OBJECTIVE: To evaluate the benefit of endoscopic application during microsurgical procedures in a retrospective study.

METHODS: One hundred eighty aneurysms were microsurgically treated in 124 operations. Three different applications of endoscopic visualization were used, depending on the respective requirements: inspection before clipping, clipping under endoscopic view, and postclipping evaluation.

RESULTS: Of 1380 aneurysms, 292 procedures were done with application of the endoscope. Of these 292, a complete data set, including video recording of the procedures for retrospective evaluation, was available in 180 cases. In these, the endoscope provided a favorable enhancement of the visual field, particularly in complex or deepseated lesions. No adverse effects were observed. Before clipping, the endoscope was used to gain additional topographic information in 150 of 180 cases (83%). Clipping under endoscopic view was performed in 4 cases. After clipping, endoscopic inspection was performed in 130 of 180 procedures. Depending on the endoscopic findings, rearrangement of the applied clip or additional clipping was found to be necessary in 26 of 130 cases (20.0%).

CONCLUSION: Endoscopic enhancement of the visual field provided by the endoscope before, during, and after microsurgical aneurysm occlusion may be a safe and effective application to increase the quality of treatment. Although unexpected findings concerning completeness of aneurysm occlusion and compromise of involved vessels could be diminished by endoscopic assessment, total prevention was not accomplished.

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Surgical nuances for the endoscopic endonasal transpterygoid approach to lateral sphenoid sinus encephaloceles

Neurosurg Focus 32 (6):E5, 2012

Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions.

However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches. In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases.

The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.

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Surgical nuances for the endoscopic endonasal transpterygoid approach to lateral sphenoid sinus encephaloceles

Neurosurg Focus 32 (6):E5, 2012. (http://thejns.org/doi/abs/10.3171/2012.3.FOCUS1267)

Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions. However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches.

In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases.

The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.

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Optimal trajectory of endoscopic third ventriculostomy

J Neurosurg 116:1153–1157, 2012. http://thejns.org/doi/abs/10.3171/2012.2.JNS111287

An optimal entry point for endoscopic third ventriculostomy (ETV) helps protect critical structures from undue manipulation. A commonly accepted ideal entry point is 3 cm from the midline and 1 cm anterior to the coronal suture. The authors of this study reexamine this ideal entry point.

Methods. Trajectory views from MR images or CT scans used for cranial image guidance in 53 patients (age range 3–85 years) who had undergone ETV were retrospectively evaluated. The trajectory from the tuber cinereum back through the center of the foramen of Monro was projected to the surface of the head. The relation of the entry point to the midline and the coronal suture was established.

Results. The mean perpendicular distance from the ideal entry point to the midline was 30.1 ± 7 mm (median 31.9 mm, range 12.5–42.2 mm). The mean perpendicular distance to the coronal suture was 8.9 ± 14.1 mm posterior (median 10.4 mm), ranging from 30.6 mm anterior to 35.8 mm posterior. The entry point tended to be located more posteriorly in women and adults: 5.8 ± 15.4 mm posterior in males versus 13.1 ± 13.2 mm posterior in females (p = 0.08) and 9.1 ± 14.8 mm posterior in adults versus 8.2 ± 11.7 mm posterior in children (p = 0.84).

Conclusions. While the entry point may need to be modified from the ideal trajectory for other anatomical reasons, such as a trajectory through the motor cortex, in general, the authors found that the optimal entry point for ETV was more posterior than previously published and highly variable. Using image guidance or a customized trajectory based on analysis of a patient’s own imaging is highly preferable to using an empirical ideal trajectory.

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Complications of endoscopic microdiscectomy using the EASYGO! system

Acta Neurochir DOI 10.1007/s00701-012-1321-5.

Microendoscopic discectomy (MED) is emerging as a minimally invasive alternative to conventional microsurgical discectomy (MSD). EASYGO! is a new system for spinal endoscopy that claims smooth transition from MSD to MED, with a reduced learning curve period. The aims of this study were to describe the complications that appeared during the learning curve period of MED and to compare their incidence with the rate and type of complications that occurred during a simultaneous non-randomised series of standard MSDs.

Methods Between July 2009 and December 2010, 138 patients underwent scheduled first-time discectomy in our institution, 37 using an MED approach and 101 by a conventional MSD. A MED learning curve was obtained by plotting every case with its respective operative time. Complications, length of hospital stay, need of further surgery and outcome were prospectively recorded in both groups.

Results The mean operative time was 66 min for the MSD group and 100 min for the MED group, although for the last 14 cases of the latter group the time was reduced. Curvefitting techniques showed that the inverse equation, ƒ(x)= 122.12/x+73.05, had the best correlation between case number and operative time. The learning curve was overcome after the 30th case. Complications occurred in 9.8 % of the MSD group and 8.1 % of the MED group (P=0.49). Average length of hospital stay was 2.36 days for the MED group and 3.36 days for the MSD group (P=0.01). The procedure successfully relieved patient symptoms in 68.63 % of the MSD group and 89.92 % of the MED group. No revision surgery was required in the MED group, but it was necessary in ten patients of the MSD group.

Conclusions Between 25 and 30 cases are needed to reach the learning curve’s asymptote of MED. Even during this initial learning period MED is a safe procedure, with comparable results to those obtained with conventional MSD and with a similar complication rate. The key points for reducing intraoperative complications are an adequate expertise in MSD, a precise selection of initial cases, a proper surgical planning and a careful technique, which are mandatory to avoid unnecessary neurological injury in an otherwise secure surgical approach.

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Image-Guided Thoracoscopic Resection of Thoracic Dumbbell Nerve Sheath Tumors

Neurosurgery 70:461–468, 2012 DOI: 10.1227/NEU.0b013e318235ba96

Surgical removal of dumbbell nerve sheath tumors (NSTs) remains challenging because these neoplasms occupy ≥ 2 spinal and extraspinal spaces. The presence of intraspinal extension, tumor dimension, and/or its location within the thoracic cavity have previously made the resection of these types of neoplasms difficult.

OBJECTIVE: To describe the feasibility of performing minimally invasive thoracoscopic surgery, as facilitated by an image guidance system (IGS), to achieve gross total resection of select dumbbell NSTs located in the thoracic spine.

METHODS: The 3 cases presented here contained small intraspinal or foraminal components. Preoperative symptoms included Horner syndrome and back and chest wall pain. We used IGS to help guide the complete thoracoscopic resection of select dumbbell NSTs, consisting of extradural, intraforaminal, and paravertebral tumor components, which previously would have been challenging with only a thoracoscopic approach.

RESULTS: IGS provided continuous intraoperative anatomic orientation to achieve gross total resection in all 3 cases. All surgical and postsurgical outcomes were satisfactory; preoperative symptoms improved or resolved; and no adverse events were observed.

CONCLUSION: Thoracic dumbbell NSTs that have small intraspinal or foraminal components could be resected thoracoscopically when facilitated by IGS. Image-guided thoracoscopic resection of such dumbbell tumors may not only improve the precision of resection, reduce recurrence, and avoid the need for spinal reconstruction but also obviate the need for more invasive or simultaneous posterior procedures. The IGS enhances the accuracy and safety of 2-dimensional thoracoscopic surgery and may reduce its learning curve.

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