Magnetic Resonance Morphometry of Normal Cerebral Aqueduct in South Indian Population

Introduction Cerebral aqueduct (of Sylvius) connects the third and fourth ventricles of the brain, and the shape of the aqueduct varies. The aim of the study is to assess the morphometry of the cerebral aqueduct in normal south Indian adult population and to look for pattern by shape, if any. Materials and Methods One hundred and fifty normal brain MR images (75 males and 75 females) using 3D heavily T2-weighted sequence were analyzed for various normal parameters of cerebral aqueduct. Mean and standard deviation were calculated. Based on the shape of the aqueduct, an attempt was made to classify them. Unpaired t-test was used to assess any significant difference between age groups and gender. The intraclass coefficient correlation was used to analyze the interobserver variability. Results The mean value of the length of the cranial and caudal part of aqueduct in males were 0.69 cm and 0.86 cm and in females 0.65 cm and 0.80 cm, respectively. The length was more in males, and it was statistically significant (p = 0.006 and 0.02). There are four types of cerebral aqueduct based on shape. Conclusion MRI is considered as the investigation of choice for preoperative planning of brain operative procedures. The MR morphometric evaluation of cerebral aqueduct provides precise knowledge about the anatomy and may be of help in the diagnosis and treatment by endoscopic neurosurgery.

Sub-specialty in neurosurgery: Time has come for Nepal

With over 90 practicing neurosurgeons in the country, should we be developing sub-specialty in neurosurgery? The number of trained manpower has risen steadily, since neurosurgery was first practiced in Nepal in 1961.1Though we are halfway to the milestone of achieving a ratio of 1 neurosurgeon for every 1 lac population, the situation here is much better than in other Sub-Saharan African and south east Asian countries.2 All the seven states have now neurosurgeons working in its hospitals, though most are still concentrated in the capitals and major towns. Recently for the last five years, despite of lack of training opportunities for sub-specialty in the country, we have seen young neurosurgeons getting trained in skull base, spine, minimally invasive or endoscopic neurosurgery, functional neurosurgery, pediatric neurosurgery and vascular neurosurgery from abroad. There is a variation in nature and period of training, ranging from observership of a few weeks to fellowship of over a year. The interest seems to be getting stronger as the facilities and complexities of cases are increasing. In such scenarios, rather than few individuals we need units or teams offering these sub-specialized services from key centers and start supervised systematic training for the interested.

Endoscope-controlled Access to Thalamic Tumors using Tubular Brain Retractor: An Alternative Approach to Microscopic Excision

Background Surgery for thalamic lesions has been considered challenging due to their deep-seated location. Endoscopic excision of deep-seated brain tumors using tubular retractor has been shown to be safe and effective in prior studies; however, there are limited reports regarding its use for thalamic tumors. We present our experience of endoscope-controlled resection of thalamic tumors using a tubular retractor. Material and Methods This was a prospective observational case series done at a tertiary center specialized for endoscopic neurosurgery during the period from 2010 to 2019. Surgeries were performed under the endoscopic control using a silicon tubular retractor. Lesions were approached transcortically or trans-sulcally. Data were collected for the extent of resection, amount of blood loss, operative time, need for conversion to microscopy, and complications. Results Twenty-one patients of thalamic masses of 14- to 60-year age underwent the surgeries. Pathologies ranged from grade I to IV gliomas. Gross total and near-total resection could be done in 42.85% of cases for each group. The average blood loss and operative time were164.04 ± 83.63 mL and 157.14 ± 28.70 minutes, respectively. Complications included a small brain contusion, two transient hemipareses, and one transient speech deficit. Conclusion Endoscopic excision of thalamic tumors using a tubular retractor was found to be a safe and effective alternative to microscopic resection.

A Minimally Invasive Endoscopic Technique for Fascia Lata Graft Acquisition and Fascial Reapproximation

BACKGROUND Fascia lata remains a popular and robust graft to repair osteodural defects in endoscopic neurosurgery. Classically, this graft is obtained via a large incision in the thigh that is prone to pain and muscle herniation after surgery. OBJECTIVE To present a novel technique for harvesting fat and fascia lata graft and reapproximating the edges via an endoscopic approach through the thigh using an “outside-in” technique to prevent muscle herniation. METHODS Initially our technique was performed in cadavers and includes the following: small 2 cm incision in the lateral thigh to accommodate the endoscope, use of blunt dissection and endoscopic tools to obtain the graft, and reapproximation of the fascia via an outside-in technique using conventional sutures with endoscopic visualization to retrieve the sutures beneath the skin and tie them. We then applied the technique to a patient undergoing transsphenoidal tumor resection. RESULTS This technique was trialed in 3 cadaver specimens (6 limbs) and was used successfully in a patient with excellent cosmetic results seen in follow-up. CONCLUSION Endoscopic retrieval of fascia lata is feasible via a very small incision. Reapproximation of the cut fascial edges to minimize muscle herniation can quickly and easily be performed with an outside-in technique detailed here. Additional case series may help to solidify the endoscopic retrieval as a preferred technique for fascia lata graft.

Assessing the surgical outcome of the “chopsticks” technique in endoscopic transsphenoidal adenoma surgery

OBJECTIVEThe “chopsticks” technique is a 3-instrument, 2-hand mononostril technique that has been recently introduced in endoscopic neurosurgery. It allows a dynamic surgical view controlled by one surgeon only while keeping bimanual dissection. Being a mononostril approach, it requires manipulation of the mucosa of one nasal cavity only. The rationale of the technique is to reduce nasal morbidity without compromising surgical results and complication rates. There are, however, no data available on its results in endoscopic surgery (transsphenoidal surgery [TSS]) for pituitary adenoma.METHODSThe authors performed a cohort analysis of prospectively collected data on 144 patients (156 operations) undergoing TSS using the chopsticks technique with 3T intraoperative MRI. All patients had at least 3 months of postoperative neurosurgical, endocrinological, and rhinological follow-up (Sino-Nasal Outcome Test–20 [SNOT-20] and Sniffin’ Sticks). The surgical technique is described, and the achieved gross-total resection (GTR) and extent of resection (EOR) together with patients’ clinical outcomes and complications are descriptively reported.RESULTSOn 3-month postoperative MRI, GTR was achieved in 71.2% of patients with a mean EOR of 96.7%. GTR was the surgical goal in 122 of 156 cases and was achieved in 106 of 122 (86.9%), with a mean EOR of 98.7% (median 100%, range 49%–100%). There was no surgical mortality. At a median follow-up of 15 months (range 3–70 months), there was 1 permanent neurological deficit. As of the last available follow-up, 11.5% of patients had a new pituitary single-axis deficit, whereas 26.3% had improvement in endocrinological function. Three patients had new postoperative hyposmia. One patient had severe impairment of sinonasal function (SNOT-20 score > 40). The operation resulted in endocrine remission in 81.1% of patients with secreting adenomas.CONCLUSIONSThis study shows that the chopsticks technique confers resection and morbidity results that compare favorably with literature reports of TSS. This technique permits a single surgeon to perform effective endoscopic bimanual dissection through a single nostril, reducing manipulation of healthy tissue and thereby possibly minimizing surgical morbidity.