Vinayak Nagaraja
University of Sydney
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Featured researches published by Vinayak Nagaraja.
Journal of gastrointestinal oncology | 2014
Vinayak Nagaraja; Michael R. Cox
BACKGROUND Open surgical gastrojejunostomy (GJ) has been the treatment of choice, but it has high morbidity and mortality rates. During the last decade, endoscopic self-expandable metal stents (SEMS) have been used. This meta-analysis aimed to compare surgical GJ and endoscopic stenting in palliation of malignant gastric outlet obstruction (GOO). METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. The search identified 3 randomized controlled trials (RCTs) and 14 non-RCTs reporting on patients who underwent surgical GJ or endoscopic stenting for malignant gastroduodenal outflow obstruction. RESULTS THE RESULTS OF THE THREE RCTS DEMONSTRATED THAT SEMS RESULTED IN COMPARABLE MAJOR [ODDS RATIO (OR): 0.62, 95% confidence intervals (CI): 0.021-18.371] and minor (OR: 0.32, 95% CI: 0.049-2.089) complications in a shorter time to tolerating an oral intake (SEMS: 3.55 days and GJ: 7.15 days) and shorter hospital stay (SEMS: 5.1 days and GJ: 12.13 days, however, statistical insignificant P value =0.11). Among the non RCTs: SEMS resulted in a shorter time to tolerating an oral intake (SEMS: 1.48 days and GJ: 8.07 days, P value <0.01), similar rate of complications (OR: 0.33, 95% CI: 0.1-1.08), lower mortality (OR: 0.5, 95% CI: 0.21-1.20, P value <0.01) and a shorter hospital stay (SEMS: 7.61 days and GJ: 19.04 days, P value <0.0001). There was no significant difference between median survival times among RCTs and non RCTs. CONCLUSIONS These findings suggest that stent placement is associated with better short-term outcomes and hence, duodenal stenting is a safe means of palliating malignant gastric outflow obstruction. However, a large RCT is needed to systematically compare stent placement with GJ with regard to medical effects, quality of life and costs.
Ejso | 2013
Vinayak Nagaraja
BACKGROUND The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a complete lymph node dissection (CLND). However, metastatic melanoma is not present in approximately 80% of CLND specimens. A meta-analysis was performed to identify the clinicopathological variables most predictive of non-sentinel node (NSN) metastases when the sentinel node is positive in patients with melanoma. METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google scholar, Science Direct, and Web of Science. The search identified 54 relevant articles reporting the frequency of NSN metastases in melanoma. Original data was abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI). FINDINGS The pooled estimates that were found to be significantly associated with the high likelihood of NSN metastases were: ulceration (OR: 1.88, 95% CI: 1.53-2.31), satellitosis (OR: 3.25, 95% CI: 1.86-5.66), neurotropism (OR: 2.51, 95% CI: 1.39-4.53), >1 positive SLN (OR: 1.77, 95% CI: 1.2-2.62), Starz 3 (old) (OR: 1.83, 95% CI: 0.89-3.76), Angiolymphatic invasion (OR: 2.46, 95% CI: 1.34-4.54), extensive location (OR: 2.22, 95% CI: 1.74-2.81), macrometastases >2 mm (OR: 1.95, 95% CI: 1.61-2.35), extranodal extension (OR: 3.38, 95% CI: 1.79-6.40) and capsular involvement (OR: 3.16, 95% CI: 1.37-7.27). There were 3 characteristics not associated with NSN metastases: subcapsular location (OR: 0.51, 95% CI: 0.38-0.67), Rotterdam Criteria <0.1 mm (OR: 0.29, 95% CI: 0.17-0.50) and Starz I (new) (OR: 0.44, 95% CI: 0.22-0.91). Other variables including gender, Breslow thickness 2-4 mm and extremity as primary site were found to be equivocal. INTERPRETATION This meta-analysis provides evidence that patients with low SLN tumor burden could probably be spared the morbidity associated with CLND. We identified 9 factors predictive of non-SLN metastases that should be recorded and evaluated routinely in SLN databases. However, further studies are needed to confirm the standard criteria for not performing CLND.
Alimentary Pharmacology & Therapeutics | 2014
Vinayak Nagaraja
Carcinoma of the gall‐bladder is the fifth commonest gastrointestinal tract cancer and is endemic in several countries. An association of chronic typhoid carriage and carcinoma of the gall‐bladder has been reported.
Heart Lung and Circulation | 2013
Vinayak Nagaraja; Jwalant Raval; David Burgess; A. Robert Denniss
INTRODUCTION The prevalence of patent foramen ovale among patients with cryptogenic stroke is higher than that in the general population. Closure with a percutaneous device is often recommended in such patients, but it is not known whether this intervention reduces the risk of recurrent stroke. METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data were abstracted from each study and used to calculate a pooled event rate (ER), odd ratio (OR) and 95% confidence interval (95% CI). RESULTS Only three randomised trials comprising 2303 patients met full criteria for analysis. Procedural success (ER: 94.20%, 95% CI: 87.6-97.4%) and effective closure (ER: 92.70%, 95% CI: 85.9-96.4%) of closure therapy were good. The odds ratio for stroke (OR: 0.654, 95% CI: 0.358-1.193) and transient ischaemic attack (OR: 0.768, 95% CI: 0.413-1.429) did not confer a benefit of PFO closure over medical therapy. Age {<45 years (OR: 0.449, 95% CI: 0.117-1.722), >45 years (OR: 0.707, 95% CI: 0.27-1.856)}, gender {males (OR: 0.498, 95% CI: 0.247-1.004), females (OR: 1.16, 95% CI: 0.597-2.255)}, substantial shunt size (OR: 0.354, 95% CI: 0.089-1.406) and the presence of atrial septal aneurysm (OR: 0.7, 95% CI: 0.21-2.33) did not influence the treatment effect of PFO closure. However, the adverse events like major vascular complication (OR: 10.905, 95% CI: 1.997-59.562) and atrial fibrillation (OR: 3.297, 95% CI: 0.874-12.432) were significantly higher in the closure group. CONCLUSIONS In patients with cryptogenic stroke or TIA who had a patent foramen ovale, closure with a device does not confer an advantage over medical therapy and is associated with adverse events like major vascular complication and atrial fibrillation.
Heart Lung and Circulation | 2014
Jwalant Raval; Vinayak Nagaraja; A. Robert Denniss
INTRODUCTION Transcatheter aortic valve implantation (TAVI) has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness and outcomes of this emerging procedure. We have examined available literature to provide an overview of valve-in-valve implantation using transcatheter heart valves (THVs) in aortic, mitral, pulmonary, tricuspid positions. METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. RESULTS Only 61 studies met full criteria and were included the review. This included 31 studies reporting transcatheter aortic valve-in-valve implantation, mitral valve-in-valve implantation (13 studies), tricuspid valve-in-valve implantation (12 studies), and pure native aortic valve regurgitation (nine studies). One of the limitations of this review is that most of the studies included were case reports, together with some case series. CONCLUSION Valve-in-valve implantation can be considered as an acceptable alternative to conventional open heart surgery for elderly high-risk surgical patients with bioprosthetic degeneration. Long-term follow-up of treated patients will be necessary to establish the true role of valve-in-valve implantation for bioprosthetic degeneration. Patients should be evaluated on an individual basis until outcomes are proven in large cohort studies or randomised trials.
Journal of gastrointestinal oncology | 2014
Vinayak Nagaraja
BACKGROUND The incidence of esophageal cancer is rising, and survival rates remain poor. This meta-analysis summarizes five molecular mechanisms of disease progression, which are related to prognosis. PATIENTS AND METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data was abstracted from each study and used to calculate a pooled event rate and 95% confidence interval (95% CI). RESULTS Our analysis included five octamer-binding transcription factor 4 (OCT4) studies (564 patients), six sex determining region Y-box 2 (SOX2) studies (336 patients), five oestrogen receptor (ER) studies (367 patients), seven MET or MNNG HOS Transforming gene (c-Met) studies (1,015 patients) and six insulin like growth factor receptor studies (764 patients). Incidence of OCT4 in SCC was 53.60% (95% CI: 0.182-0.857) and the overall hazard ratio for poor clinic outcome was 2.9 (95% CI: 1.843-4.565). The incidence of SOX2 in SCC was 69.2% (95% CI: 0.361-0.899) however, was associated with significant heterogeneity of 90.94%. The prevalence of Oestrogen receptor α and β in SCC were 37.90% (95% CI: 0.317-0.444) and 67.20% (95% CI: 0.314-0.901) respectively. The prevalence of MET in EAC was 33.20% (95% CI: 0.031-0.884) and the incidence of insulin-like growth factor-1 receptor (IGF-1R) in EAC was 67.70% (95% CI: 0.333-0.898). CONCLUSIONS Our results show that the status of ER, OCT4 and SOX2 expression correlates with the unfavourable prognosis in patients with esophageal squamous cell carcinoma (ESCC). This study also highlights the potential impact of the IGF-1R on the biology of EAC and the expression of Met was recognised as a significant prognostic factor. Our data supports the concept of IGF axis, ER, Met, OCT4 and SOX2 inhibition as (neo-) adjuvant treatment.
Internal Medicine Journal | 2015
L. Back; Vinayak Nagaraja; A. Kapur
Prognosis for patients with ‘malignant’ or space‐occupying oedema post middle cerebral artery infarct remains poor despite maximal medical therapy delivered in the intensive care setting.
Journal of gastrointestinal oncology | 2014
Vinayak Nagaraja; Michael R. Cox
BACKGROUND Patients with locally advanced esophageal cancer who require neoadjuvant therapy have significant dysphagia and may severely impair nutritional status. We conducted a meta-analysis to assess the efficacy of self-expandable metal stents prior to neoadjuvant therapy. METHODS A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data was abstracted from each study and used to calculate a pooled odd ratio (OR) and 95% confidence interval (95% CI). RESULTS Only nine studies comprising of 180 patients were included for analysis. The overall procedural success rate was 95% (95% CI, 0.895-0.977). There was a substantial decrease in the dysphagia scores standard difference in means (SDM) -0.81 [standard error (SE) 0.15, 95% CI, -1.1 to -0.51], similar increase in weight SDM 0.591 (SE 0.434, 95% CI, -0.261 to 1.442) and serum albumin SDM 0.35 (SE 0.271, 95% CI, -0.181 to 0.881). The incidence of major adverse events included stent migration 32% (95% CI, 0.258-0.395) and chest discomfort 51.4% (95% CI, 0.206-0.812). CONCLUSIONS Placement of stents in patients with locally advanced esophageal cancer significantly improves dysphagia and allows for oral nutrition during neoadjuvant therapy. Stents appear to be effective for palliating dysphagia. Stent migration was a common occurrence; however, migration may be a sign of tumor response to neoadjuvant therapy.
Internal Medicine Journal | 2015
S B Jung; Vinayak Nagaraja; Amit Kapur
Vitamin B12 (cobalamin) deficiency can result in irreversible structural brain changes if not treated appropriately. Long‐term use of acid‐lowering agents (ALA) has been linked to vitamin B12 deficiency, but results are inconsistent.
Open Heart | 2014
Vinayak Nagaraja; Jwalant Raval; Andrew T.L. Ong
Introduction Many patients deemed inoperable for surgical aortic valve replacement (SAVR) have been treated successfully by transcatheter aortic-valve replacement (TAVR). This meta-analysis is designed to evaluate the performance of TAVR in comparison with SAVR. Methods A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, the Cochrane library, Google Scholar, Science Direct and Web of Science. Original data were abstracted from each study and used to calculate a pooled OR and 95% CI. Results Among three randomised controlled trials (RCTs), differences between the two cohorts were not statistically significant for the frequency of stroke (OR=1.94, 95% CI=0.813 to 4.633), incidence of myocardial infarction (MI), (OR=0.765, 95% CI=0.05 to 11.76) 30-day mortality rate, 1-year mortality rate (0.82, 95% CI=0.62 to 1.09) and acute kidney injury incidence rate. The non-RCTs demonstrated that the TAVR group had an amplified frequency aortic regurgitation at discharge (OR=5.465, 95% CI=3.441 to 8.680). While differences between the two cohorts were not statistically significant for the incidence of MI (OR=0.697, 95% CI=0.22 to 2.21), stroke (OR=0.575, 95% CI=0.263 to 1.259), acute renal failure requiring haemodialysis (OR=0.943, 95% CI=0.276 to 3.222), 30-day mortality (OR=0.869, 95% CI=0.621 to 1.216) and the need for a pacemaker (OR=1.832, 95% CI=0.869 to 3.862), a lower incidence of patients needing transfusion (OR=0.349, 95% CI=0.121 to 1.005) and new-onset atrial fibrillation (OR=0.296, 95% CI=0.124 to 0.706) was seen in the TAVR group. Conclusions Randomised and observational evidence adjusted on the baseline patient’s characteristics finds a similar risk for 30 days mortality, 1-year mortality, stroke, MI and acute kidney injury in TAVR and SAVR.