MyMedR

Fulltext Nephrogenic adenoma of the urethra presenting as hematuria

Krishna Kumar G, Malcomson R, Chandran H

Indian J Surg, 2014 Jun;76(3):228-9.

PMID: 25177122 DOI: 10.1007/s12262-013-0932-2

A haemostatic agent delivery system for endoscopic neurosurgical procedures

Waran V, Sek K, Bahuri NF, Narayanan P, Chandran H

Minim Invasive Neurosurg, 2011 Oct;54(5-6):279-81.

PMID: 22278798 DOI: 10.1055/s-0031-1297997

In endoscopic neurosurgery problems with haemostasis due to poor access exist. We have developed a system which allows the delivery of a variety of haemostatic agents in a more efficacious manner. The system has been used successfully in endoscopic skull base surgery and endoscopic surgery within the parenchyma of the brain using tube systems.

Fulltext Calcified pseudomeningocele of the lumbar spine: a review

Narverud SF, Ramli NB, Chandran H, Ganesan D

Eur Spine J, 2013 May;22 Suppl 3:S443-9.

PMID: 23233216 DOI: 10.1007/s00586-012-2610-7

In this article, we review the English literature of calcified pseudomeningoceles in the lumbar region.

Development of a bone substitute material based on alpha-tricalcium phosphate scaffold coated with carbonate apatite/poly-epsilon-caprolactone

Bang LT, Ramesh S, Purbolaksono J, Long BD, Chandran H, Ramesh S, et al.

Biomed Mater, 2015 Aug;10(4):045011.

PMID: 26225725 DOI: 10.1088/1748-6041/10/4/045011

Interconnected porous tricalcium phosphate ceramics are considered to be potential bone substitutes. However, insufficient mechanical properties when using tricalcium phosphate powders remain a challenge. To mitigate these issues, we have developed a new approach to produce an interconnected alpha-tricalcium phosphate (α-TCP) scaffold and to perform surface modification on the scaffold with a composite layer, which consists of hybrid carbonate apatite / poly-epsilon-caprolactone (CO3Ap/PCL) with enhanced mechanical properties and biological performance. Different CO3Ap combinations were tested to evaluate the optimal mechanical strength and in vitro cell response of the scaffold. The α-TCP scaffold coated with CO3Ap/PCL maintained a fully interconnected structure with a porosity of 80% to 86% and achieved an improved compressive strength mimicking that of cancellous bone. The addition of CO3Ap coupled with the fully interconnected microstructure of the α-TCP scaffolds coated with CO3Ap/PCL increased cell attachment, accelerated proliferation and resulted in greater alkaline phosphatase (ALP) activity. Hence, our bone substitute exhibited promising potential for applications in cancellous bone-type replacement.

Fulltext Electroacupuncture-Assisted Craniotomy on an Awake Patient

Sidhu A, Murgahayah T, Narayanan V, Chandran H, Waran V

J Acupunct Meridian Stud, 2017 Jan;10(1):45-48.

PMID: 28254101 DOI: 10.1016/j.jams.2016.06.005

Although acupuncture has existed for over 2000 years, its application as an anesthetic aid began in the 1950s in China. The first surgical procedure performed under acupuncture anesthesia was a tonsillectomy. Soon thereafter, major and minor surgical procedures took place with electroacupuncture alone providing the anesthesia. The procedures performed were diverse, ranging from cardiothoracic surgery to dental extractions. Usage of acupuncture anesthesia, specifically in neurosurgery, has been well documented in hospitals across China, especially in Beijing, dating back to the 1970s. We present a case of a 65-year-old man who presented with right-sided body weakness. He had a past medical history of uncontrolled diabetes mellitus, hypertension, and obstructive sleep apnea requiring use of a nasal continuous positive airway pressure device during sleep. We performed a computed tomography brain scan, which revealed a left-sided acute on chronic subdural hemorrhage. Due to his multiple comorbidities, we decided to perform the surgical procedure under electroacupuncture anesthesia. The aim of this case report is to describe a craniotomy performed under electroacupuncture on an elderly patient with multiple comorbidities who was awake during the procedure and in whom this procedure, if it had been performed under general anesthesia, would have carried high risk.

Neuronavigation with the universal probe to access intracranial targets

Waran V, Chandran H, Devaraj P, Ravindran K, Rathinam AK, Balakrishnan YK, et al.

J Neurol Surg A Cent Eur Neurosurg, 2014 Nov;75(6):422-6.

PMID: 23955263 DOI: 10.1055/s-0033-1345091

The universal probe is a tool devised to allow navigation-directed biopsies and drainage procedures to be performed in a simple manner using a single hardware and software.

A new modified speculum guided single nostril technique for endoscopic transnasal transsphenoidal surgery: an analysis of nasal complications

Waran V, Tang IP, Karuppiah R, Abd Kadir KA, Chandran H, Muthusamy KA, et al.

Br J Neurosurg, 2013 Dec;27(6):742-6.

PMID: 23647078 DOI: 10.3109/02688697.2013.791667

Abstract The endoscopic transnasal, transsphenoidal surgical technique for pituitary tumour excision has generally been regarded as a less invasive technique, ranging from single nostril to dual nostril techniques. We propose a single nostril technique using a modified nasal speculum as a preferred technique. We initially reviewed 25 patients who underwent pituitary tumour excision, via endoscopic transnasal transsphenoidal surgery, using this new modified speculum-guided single nostril technique. The results show shorter operation time with reduced intra- and post-operative nasal soft tissue injuries and complications.

Fulltext Infratentorial benign cystic meningioma mimicking a hemangioblastoma radiologically and a pilocytic astrocytoma intraoperatively: a case report

Guan TK, Pancharatnam D, Chandran H, Hooi TK, Kumar G, Ganesan D

J Med Case Rep, 2013;7:87.

PMID: 23537099 DOI: 10.1186/1752-1947-7-87

Cystic meningiomas are rare variants of meningiomas; they can pose a radiological diagnostic dilemma.

Combined endoscopic transnasal and transoral approach for extensive upper cervical osteoradionecrosis

Tan SH, Ganesan D, Rusydi WZ, Chandran H, Prepageran N, Waran V

Eur Spine J, 2015 Dec;24(12):2776-80.

PMID: 26210311 DOI: 10.1007/s00586-015-4153-1

PURPOSE: Osteoradionecrosis (ORN) is a rare yet well-recognized complication following radiotherapy to the head and neck. We illustrate the only case of a spontaneous extrusion of the sequestered C1 arch through the oral cavity and discuss our experience with a combined endoscopic transnasal and transoral approach for cervical ORN.

METHODS: A 56-year-old female presented with a 3-month history of blood-stained nasal discharge. She had been treated with radiotherapy for nasopharyngeal carcinoma 25 years earlier. Flexible nasal endoscopy demonstrated an exposed bone with an edematous posterior nasopharyngeal mass. Computed tomography showed a pre-vertebral mass with destruction of C1 and C2. She underwent occipito-cervical fusion followed by a combined transnasal and transoral endoscopic debridement of non-viable bone in the same perioperative setting. Healing of the raw mucosa was by secondary intention and reconstruction was not performed.

RESULTS: Histopathological examination reported ulcerated inflamed granulation tissue with no evidence of malignancy. During follow-up, she remained neurologically intact with no recurrence.

CONCLUSION: Using both nasal and oral spaces allows placement of the endoscope in the nasal cavity and surgical instruments in the oral cavity without splitting the palate. Hence, the endoscopic transnasal and transoral approach has vast potential to be effective in carefully selected cases of cervical ORN.

Injecting realism in surgical training-initial simulation experience with custom 3D models

Waran V, Narayanan V, Karuppiah R, Pancharatnam D, Chandran H, Raman R, et al.

J Surg Educ, 2014 Mar-Apr;71(2):193-7.

PMID: 24602709 DOI: 10.1016/j.jsurg.2013.08.010

The traditionally accepted form of training is direct supervision by an expert; however, modern trends in medicine have made this progressively more difficult to achieve. A 3-dimensional printer makes it possible to convert patients imaging data into accurate models, thus allowing the possibility to reproduce models with pathology. This enables a large number of trainees to be trained simultaneously using realistic models simulating actual neurosurgical procedures. The aim of this study was to assess the usefulness of these models in training surgeons to perform standard procedures that require complex techniques and equipment.

The creation and verification of cranial models using three-dimensional rapid prototyping technology in field of transnasal sphenoid endoscopy

Waran V, Menon R, Pancharatnam D, Rathinam AK, Balakrishnan YK, Tung TS, et al.

Am J Rhinol Allergy, 2012 Sep-Oct;26(5):e132-6.

PMID: 23168144 DOI: 10.2500/ajra.2012.26.3808

Surgical navigation systems have been used increasingly in guiding complex ear, nose, and throat surgery. Although these are helpful, they are only beneficial intraoperatively; thus, the novice surgeon will not have the preoperative training or exposure that can be vital in complex procedures. In addition, there is a lack of reliable models to give surgeons hands-on training in performing such procedures.

Lipid Fraction Derived From MRI In- and Opposed-Phase Sequence as a Novel Biomarker for Predicting Survival Outcome of Glioma

Seow P, Narayanan V, Romelean RJ, Wong JHD, Win MT, Chandran H, et al.

Acad Radiol, 2020 02;27(2):180-187.

PMID: 31155487 DOI: 10.1016/j.acra.2019.04.015

RATIONALE AND PURPOSE: Our study evaluated the capability of magnetic resonance imaging in- and opposed-phase (IOP) derived lipid fraction as a novel prognostic biomarker of survival outcome in glioma.

MATERIALS AND METHODS: We analyzed 46 histologically proven glioma (WHO grades II-IV) patients using standard 3T magnetic resonance imaging brain tumor protocol and IOP sequence. Lipid fraction was derived from the IOP sequence signal-loss ratio. The lipid fraction of solid nonenhancing region of glioma was analyzed, using a three-group analysis approach based on volume under surface of receiver-operating characteristics to stratify the prognostic factors into three groups of low, medium, and high lipid fraction. The survival outcome was evaluated, using Kaplan-Meier survival analysis and Cox regression model.

RESULTS: Significant differences were seen between the three groups (low, medium, and high lipid fraction groups) stratified by the optimal cut-off point for overall survival (OS) (p ≤ 0.01) and time to progression (p ≤ 0.01) for solid nonenhancing region. The group with high lipid fraction had five times higher risk of poor survival and earlier time to progression compared to the low lipid fraction group. The OS plot stratified by lipid fraction also had a strong correlation with OS plot stratified by WHO grade (R = 0.61, p < 0.01), implying association to underlying histopathological changes.

CONCLUSION: The lipid fraction of solid nonenhancing region showed potential for prognostication of glioma. This method will be a useful adjunct in imaging protocol for treatment stratification and as a prognostic tool in glioma patients.

Prognostic factors in patients with non-small cell lung carcinoma and brain metastases: a Malaysian perspective

Tang WH, Alip A, Saad M, Phua VC, Chandran H, Tan YH, et al.

Asian Pac J Cancer Prev, 2015;16(5):1901-6.

PMID: 25773842

BACKGROUND: Brain metastases occur in about 20-40% of patients with non-small-cell lung carcinoma (NSCLC), and are usually associated with a poor outcome. Whole brain radiotherapy (WBRT) is widely used but increasingly, more aggressive local treatments such as surgery or stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) are being employed. In our study we aimed to describe the various factors affecting outcomes in NSCLC patients receiving local therapy for brain metastases.

MATERIALS AND METHODS: The case records of 125 patients with NSCLC and brain metastases consecutively treated with radiotherapy at two tertiary centres from January 2006 to June 2012 were analysed for patient, tumour and treatment-related prognostic factors. Patients receiving SRS/SRT were treated using Cyberknife. Variables were examined in univariate and multivariate testing.

RESULTS: Overall median survival was 3.4 months (95%CI: 1.7-5.1). Median survival for patients with multiple metastases receiving WBRT was 1.5 months, 1-3 metastases receiving WBRT was 3.6 months and 1-3 metastases receiving surgery or SRS/SRT was 8.9 months. ECOG score (≤2 vs >2, p=0.001), presence of seizure (yes versus no, p=0.031), treatment modality according to number of brain metastases (1-3 metastases+surgery or SRS/SRT±WBRT vs 1-3 metastases+WBRT only vs multiple metastases+WBRT only, p=0.007) and the use of post-therapy systemic treatment (yes versus no, p=0.001) emerged as significant on univariate analysis. All four factors remained statistically significant on multivariate analysis.

CONCLUSIONS: ECOG ≤2, presence of seizures, oligometastatic disease treated with aggressive local therapy (surgery or SRS/SRT) and the use of post-therapy systemic treatment are favourable prognostic factors in NSCLC patients with brain metastases.

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