Neuroendoscopy in the Surgical Management of Lateral and Third Ventricular Tumors: Looking Beyond Microneurosurgery.

BACKGROUND: Intraventricular tumors pose a surgical challenge because of the difficulty in reaching their deep location through safe corridors and their adherence or proximity to vital neurovascular structures. Although microneurosurgery is the mainstay of surgical management, neuroendoscopy aided by adjuncts, namely, navigation and ultrasonic aspirators, has made a great contribution to improving surgical results. OBJECTIVE: This article reviews the experience of a neurosurgical unit with endoscopic procedures for intraventricular tumors. The current indications, benefits, and complications of neuroendoscopy are described. MATERIALS AND METHODS: This is a retrospective, observational study of lateral and third ventricular tumors tackled either purely with an endoscope or with its assistance over 19 years in a single unit at Bombay Hospital Institute of Medical Sciences, Mumbai. RESULTS: Of a total of 247 operated patients with intraventricular tumors, 85 cases operated using an endoscope were included. The majority of the patients had a tumor in the third ventricle (n = 62), whereas 23 patients had tumor in the lateral ventricle. The most common pathologies were colloid cyst and arachnoid cyst (n = 18). An endoscope was used for microsurgical assisted excision of tumors in 31 cases, biopsy in 24, cyst fenestration in 23, and pure endoscopic excision in seven cases. CONCLUSION: Microsurgery remains the gold standard for the removal of giant, vascular intraventricular tumors. However, endoscopic fenestration or excision of cysts and biopsy have become better alternatives in many cases. Endoscope-assisted microsurgery affords safety and helps in achieving a more complete excision.

Experience with Management of Intracranial Arachnoid Cysts.

OBJECTIVES: The aim of this study was to analyze the demographics, clinical presentation, and surgical outcome of intracranial arachnoid cysts and to review the surgical options. METHODS: This is a retrospective observational study of 56 cases of symptomatic arachnoid cysts among all age groups treated between 2004 and 2020 at the Bombay Hospital, Mumbai. Endoscopic fenestration, microsurgical cyst excision, and shunt insertion were the interventions performed. Clinical presentation, cyst reduction post-intervention, and complications were studied. The follow-up period varied from 1 month to 16 years. Statistical analysis was done for 43 patients with a minimum of 3 years' follow-up. RESULTS: In all, 75% of patients were <18 years of age. Of these, the majority were between the age of 1 and 10 years. There were 14 cases of temporal, 13 cases of retrocerebellar, 10 cases of quadrigeminal cistern, and 7 cases each of interhemispheric and suprasellar arachnoid cysts. The most common clinical presentation was headache and vomiting. Concomitant hydrocephalus was seen on imaging in 24 cases. Endoscopic fenestration of cyst was the most routinely performed procedure (35 cases). Four patients of endoscopic fenestration underwent a redo endoscopic procedure on follow-up. Post-operative reduction in cyst size was found to be significantly better after endoscopic fenestration (p < 0.05). CONCLUSION: Though the best available treatment for arachnoid cysts remains controversial, surgery has been found to be beneficial in symptomatic cases. Endoscopic fenestration is considered the first-line surgical option and it may be followed by shunt, if necessary. Shunts may be preferred in very young children where there is associated hydrocephalus/macrocephaly.

Sellar Pathologies Mimicking Pituitary Tumors.

The most common sellar pathology that merits neurosurgical attention is the pituitary adenoma. However, some developmental, inflammatory, and neoplastic lesions may primarily or secondarily involve the sella, mimicking pituitary tumors. Advances in imaging and endocrinological assessment have helped in the recognition of these less common sellar, supra sellar pathologies, which may occasionally create confusion in management. The most common developmental anomaly is the Rathke's cleft cyst and an increasingly recognized inflammatory pathology is the spectrum of hypophysitis. Neoplasms, viz. Craniopharyngioma, Germinoma, Langerhans's cell histiocytosis or metastasis, have more distinctive features in various age groups and are more likely to be correctly diagnosed on current imaging and managed accordingly. This review looks at mainly intraparenchymal pathologies, namely Rathke's Cleft Cyst and various hypophysitides, and will discuss their management strategies.

Endonasal endoscopic skullbase surgery in children.

OBJECTIVE: The role of endonasal endoscopic approach for pathologies in the paediatric population is evolving and has still not been accepted as standard of care in neurosurgery. It represents a challenge in terms of narrow access, instrument manipulation and adequate reconstruction of defects. We have described our experience in 49 cases from a single neurosurgical unit in paediatric skull base surgeries through this approach over the last 12 years. MATERIAL AND METHODS: A case series of 59 paediatric skull base surgeries in 49 children through endoscopic endonasal route over the last 12 years is presented. The age ranges from 4 months to 18 years. Out of 49 cases, 22 cases were of craniopharyngiomas, 8 cases of pituitary adenomas, 5 cases with CSF rhinorrhea, 5 cases with meningoencephalocele, 3 cases of Rathke's cleft cysts, 2 cases of odontoidectomy and 4 miscellaneous cases viz. mucocele, hypothalamic glioma, esthesioneuroblastoma and epidermoid. CSF leaks were repaired with free graft in the initial years and by vascularized flap more recently. RESULTS: The goal of surgery was achieved in all but two cases in whom the tumour excision was unsatisfactory due to failure of the cyst wall to collapse after decompression. Extent of tumour excision was not compromised by the choice of this approach. Revision surgery for CSF leak was required in three patients. Local vascularized nasoseptal flap has been possible even in very young patients and has now become the standard for reconstruction. CONCLUSION: In spite of the challenges posed by small nostrils and ill-developed sinuses in the paediatric age group, surgery from endoscopic endonasal corridor is possible to be carried out successfully in selected cases.

Combined endoscopic approach in the management of suprasellar craniopharyngioma.

INTRODUCTION: Craniopharyngiomas are dysontogenic tumors with benign histology but aggressive behavior. The surgical challenges posed by the tumor are well recognized. Neuroendoscopy has recently contributed to its surgical management. This study focuses on our experience in managing craniopharyngiomas in recent years, highlighting the role of combined endoscopic trans-ventricular and endonasal approach. CASE SERIES: Ninety-two patients have been treated for craniopharyngioma from 2000 to 2016 by the senior author. A total of 125 procedures, microsurgical (58) and endoscopic (67), were undertaken. Combined endoscopic approach was carried out in 18 of these patients, 16 children and 2 young adults. All of these patients presented with a large cystic suprasellar mass associated with hydrocephalus. In the first instance, they were treated with a transventricular endoscopic procedure to decompress the cystic component. This was followed by an endonasal transsphenoidal procedure for excision within the next 2 to 6 days. All these patients improved after the initial cyst decompression with relief of hydrocephalus while awaiting remaining tumor removal in a more elective setting. Gross total resection could be done in 84% of these patients. Diabetes insipidus was the most common postsurgical complication seen in 61% patients in the immediate period but was persistent in only two patients at 1-year follow-up. None of the children in this group developed morbid obesity. There was one case of CSF leak requiring repair after initial surgery. Peri-operative mortality was seen in one patient secondary to ventriculitis. DISCUSSION: The patients who benefit most from the combined approach are those who present with raised intracranial pressure secondary to a large tumor with cyst causing hydrocephalus. Intraventricular endoscopic cyst drainage allows resolution of hydrocephalus with restoration of normal intracranial pressure, gives time for proper preoperative work up, and has reduced incidence of CSF leak after transnasal surgery. CONCLUSION: Combined endoscopic approach thus gives a unique opportunity to remove these lesions more radically with less morbidity.

Surgical Management of Rathke Cleft Cysts.

BACKGROUND: The diagnosis of Rathke cleft cysts (RCC) has increased in recent times as a result of improvements in imaging techniques; however, symptomatic patients are uncommon and accurate preoperative diagnosis may sometimes be difficult. The indications of surgical management protocol are evolving. We aim to provide a comprehensive review of clinical, imaging, and histopathologic features with operative management strategies along with outcome and prognosis in RCC. METHODS: A retrospective analysis (2003-2015) was performed of 58 consecutive cases of RCC seen in a surgical unit. Twenty-seven surgically treated symptomatic RCCs were further evaluated for their clinical presentation, imaging characteristics, surgical approaches, and intraoperative findings. RESULTS: Headache was the most common presenting complaint followed by visual deficit. Hormonal abnormality was observed in 13 patients. On magnetic resonance imaging, the characteristic intracystic nodule was identified in 6 patients. Transsphenoidal surgery for cyst excision was performed in all 27 patients with an endoscopic route in 25 patients and radical excision was performed in 17 patients. The pituitary stalk and the normal gland were preserved in all patients. Headache improved in 96% of patients and visual field defect resolved in all. Around 46% had improvement of the anterior pituitary axis. New permanent hormone deficiency was not observed. The recurrence rate was 3.7% after a minimum of 18 months follow-up. CONCLUSIONS: RCCs are an uncommon disease with a wide spectrum of clinical and radiologic features. Endonasal endoscopic transsphenoidal surgery provides excellent clinical and endocrinologic improvement. We believe that radical excision does not necessarily result in endocrinologic impairment and may have a better impact on recurrence and cyst resolution.

Endoscopic Third Ventriculostomy: Success and Failure.

Endoscopic third ventriculostomy (ETV) has now become an accepted mode of hydrocephalus treatment in children. Varying degrees of success for the procedure have been reported depending on the type and etiology of hydrocephalus, age of the patient and certain technical parameters. Review of these factors for predictability of success, complications and validation of success score is presented.

Pediatric Cushing's Disease: Dichotomy in Lateralization between Imaging and Inferior Petrosal Sinus Sampling with Review of Literature.

Inferior petrosal sinus sampling (IPSS) is a minimally invasive method done in adrenocorticotrophic hormone (ACTH)-dependent pituitary adenoma cases where magnetic resonance imaging (MRI) either gives equivocal results or fails to localize it. A 12-year-girl with cushingoid features and raised ACTH levels presented to us with two consecutive MRI's done outside showing gross change in the morphology of a left-sided pituitary adenoma. Hence, a bilateral IPSS was done which showed a higher IPS/periphery ACTH ratio on the right side as compared to left. Transsphenoidal endoscopic excision of the left pituitary adenoma along with right hemihypophysectomy was performed. ACTH levels fell postoperatively. This case stands distinct in highlighting the discordance in lateralization of pituitary adenoma on MRI and IPSS. Review of literature tells us that while IPSS is more sensitive in accurately diagnosing Cushing's disease, MRI provides better accuracy in lateralizing the site of adenoma.

Endoscopic approaches to the craniovertebral junction and odontoid process.

BACKGROUND: The microsurgical transoral approach has traditionally been the preferred access for ventral decompression of the craniovertebral junction. This natural corridor, although direct, may be a challenging approach because of potential morbidities. The evolution of endoscopic methods in skull base surgeries has reduced morbidity and improved results. Endoscopic approaches are also being used for ventral decompression at the craniovertebral junction. Some technical modifications in this approach are described. METHODS: An endoscope is inserted endonasally for a panoramic view of the entire area of interest, from the sphenoid to second cervical vertebra. Image guidance systems are used in all cases to guide the resection. The soft palate is retracted away with a rubber catheter sling when both nasal and oral corridors are being used. Various mucosal flaps are raised for access and reconstruction. Actual decompression can be done through the nasal or oral corridors based on the relationship of the pathology to the palate. Reconstruction is done using standard principles with the vascularized flaps, fat, and fibrin glue. RESULTS: Reduced surgical morbidity by avoiding palatal split and good postoperative healing are some of the advantages of this modified endoscopic technique. Better surgical exposure and a wide perspective facilitate the decompression. However, as with all newer perspectives, a learning curve exists. CONCLUSIONS: Used judiciously, this modified endoscopic approach to the craniovertebral junction and odontoid process is minimally invasive and adds to the surgeon's armamentarium.

Dorsal root entry zone approach in ventral and eccentric intramedullary tumors: A report of 2 cases.

Intramedullary tumors constitute 2-4% of all the tumors affecting the central nervous system. They include low-grade astrocytomas and ependymomas in majority. Earlier, only biopsy or decompression used to be the best available options for these tumors, but with the upcoming technology and newer techniques, gross total excision with the aim of achieving complete removal has been the preferred treatment for these tumors. Usually, nearly all intramedullary tumors are approached from posterior midline myelotomy as this is the safest corridor to approach under neurophysiologic monitoring. But sometimes, if the tumor is exophytic, eccentric, or ventral to the cord, other routes of access may also be useful. These approaches are less frequently used these days and actually may be found useful in certain cases. Hence, they should not be termed "obsolete" and must be kept in mind for tumors in specific location. We describe a similar less commonly used dorsal root entry zone approach for near total excision of ventral and eccentric cervical pilocytic astrocytomas in two patients.