Niall J. O'Sullivan

Mr. Niall J. O'Sullivan

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 March 2022 in Journal of Pediatric Urology
Verified
Journal Article
Closed access
NONiall J. O'Sullivan
Niall J. O'Sullivan
GNGreg Nason
Greg Nason
RMRustom P. Manecksha
Rustom P. Manecksha
FOFardod O'KElly
Fardod O'KElly

21 May 2022 in Techniques in Coloproctology
Verified
Journal Article
Closed access
PDF file
NONiall J. O'Sullivan
Niall J. O'Sullivan
HTH. C. Temperley
H. C. Temperley
TNT. S. Nugent
T. S. Nugent
ELE. Z. Low
E. Z. Low
DKD. O. Kavanagh
D. O. Kavanagh
MKM. E. Kelly
M. E. Kelly

22 January 2023 in BJUI Compass
Verified
Journal Article
Open access
NONiall J. O'Sullivan
Niall J. O'Sullivan
ANAilish Naughton
Ailish Naughton
HTHugo C. Temperley
Hugo C. Temperley
RCRowan G. Casey
Rowan G. Casey
Background: Upper tract urothelial carcinoma (UTUC) is the malignant transformation of urothelial cells, from the renal calyces to the ureteral orifices. While the benefits of minimally invasive nephroureterectomy over their open counterpart have been established, the optimal technique remains a debate. We aimed to assess current evidence in the literature and compare outcomes between robotic‐assisted (RANU) and laparoscopic nephroureterectomy (LNU).Methods: A systematic review of the literature was performed for studies comparing RANU and LNU for bladder cancer. Outcome measurements were recurrence rates (local and distal), positive margins, positive lymph node yield and perioperative outcomes. Meta‐analysis was performed using Review Manager 5.Results: Our results demonstrate a significantly higher mortality rate in patients undergoing laparoscopic nephroureterectomy when compared with the robotic‐assisted approach for the treatment of UTUC (1.8% vs. 1.1%, p = 0.008); however, these results were inconsistent on sensitivity analysis and should therefore be interpreted with caution. No significant difference was observed for other outcomes.Conclusion: The ideal approach to minimally invasive radical nephroureterectomy remains undetermined. Future research, ideally prospective randomised studies, should focus on long‐term outcomes, in particular recurrence, recurrence‐free survival, overall survival and the correlation between surgical technique and survival.

9 May 2024 in International Journal of Colorectal Disease
Verified
Journal Article
Open access
PDF file
NONiall J. O'Sullivan
Niall J. O'Sullivan
HTHugo C Temperley
Hugo C Temperley
JLJohn Larkin
John Larkin
JMJacob J McCormick
Jacob J McCormick
EREmanuele Rausa
Emanuele Rausa
MKMichael E Kelly
Michael E Kelly
Introduction: Robotic transanal minimally invasive surgery (R-TAMIS) was introduced in 2012 for the excision of benign rectal polyps and low grade rectal cancer. Ergonomic improvements over traditional laparoscopic TAMIS (L-TAMIS) include increased dexterity within a small operative field, with possibility of better surgical precision. We aim to collate the existing data surrounding the use of R-TAMIS to treat rectal neoplasms from cohort studies and larger case series, providing a foundation for future, large-scale, comparative studies. Methods: Medline, EMBASE and Web of Science were searched as part of our review. Randomised controlled trials (RCTs), cohort studies or large case series (≥ 5 patients) investigating the use of R-TAMIS to resect rectal neoplasia (benign or malignant) were eligible for inclusion in our analysis. Quality assessment of included studies was performed via the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, operative details and histopathological/oncological outcomes. Results: Eighteen studies on 317 participants were included in our analysis. The quality of studies was generally satisfactory. Overall complication rate from R-TAMIS was 9.7%. Clear margins (R0) were reported in 96.2% of patients. Local recurrence (benign or malignant) occurred in 2.2% of patients during the specified follow-up periods. Conclusion: Our review highlights the current evidence for R-TAMIS in the local excision of rectal lesions. While R-TAMIS appears to have complication, margin negativity and recurrence rates superior to those of published L-TAMIS series, comparative studies are needed.

29 May 2024 in International Journal of Colorectal Disease
Verified
Journal Article
Open access
PDF file
NONiall J. O'Sullivan
Niall J. O'Sullivan
HTHugo C. Temperley
Hugo C. Temperley
EKEimear T. Kyle
Eimear T. Kyle
KSKevin J. Sweeney
Kevin J. Sweeney
MOMaeve O’nEill
Maeve O’nEill
MKMichael E. Kelly
Michael E. Kelly
Introduction: Circulating tumour DNA (ctDNA) has emerged as a promising biomarker in various cancer types, including locally advanced rectal cancer (LARC), offering potential insights into disease progression, treatment response and recurrence. This review aims to comprehensively evaluate the utility of ctDNA as a prognostic biomarker in LARC. Methods: PubMed, EMBASE and Web of Science were searched as part of our review. Studies investigating the utility of ctDNA in locally advanced rectal cancer (LARC) were assessed for eligibility. Quality assessment of included studies was performed using the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, ctDNA details and survival data. A meta-analysis was performed on eligible studies to determine pooled recurrence-free survival (RFS). Results: Twenty-two studies involving 1676 participants were included in our analysis. Methodological quality categorised by the Newcastle Ottawa Scale was generally satisfactory across included studies. ctDNA detected at various time intervals was generally associated with poor outcomes across included studies. Meta-analysis demonstrated a pooled hazard ratio of 8.87 (95% CI 4.91–16.03) and 15.15 (95% CI 8.21–27.95), indicating an increased risk of recurrence with ctDNA positivity in the post-neoadjuvant and post-operative periods respectively. Conclusion: Our systematic review provides evidence supporting the prognostic utility of ctDNA in patients with LARC, particularly in identifying patients at higher risk of disease recurrence in the post-neoadjuvant and post-operative periods.

27 September 2022 in Current Urology
Verified
Journal Article
Open access
NONiall J. O'Sullivan
Niall J. O'Sullivan
SASteven Anderson
Steven Anderson
Background: Pelviureteric junction obstruction (PUJO) is a common urological disorder that can present at any stage of life. The underlying etiology in children has been well studied; however, a gap exists in the literature for the adult population. Herein, we performed a systematic review of the literature to evaluate the current evidence on the underlying etiologies of adult patients presenting with PUJO. Materials and methods: Four electronic databases were searched for relevant studies assessing the underlying etiologies of pelviureteric junction obstruction in adults. Studies were assessed for eligibility based on predefined inclusion and exclusion criteria, and a critical appraisal of methodological quality and risk of bias was performed. Finally, qualitative and quantitative data analyses were performed. Results: Twelve studies comprising a total of 513 patients with radiologically confirmed PUJO met the inclusion criteria and were included in our analysis. The most common finding was crossing vessels, which were observed in 50.5% of patients, followed by intrinsic ureteral stenosis (27.1%), adhesions (15.3%), and high insertion of the ureter (10.1%). Conclusions: The underlying etiologies of PUJO in adults remain unclear. This study indicated that obstruction secondary to crossing vessels is the most common cause of obstruction in adults and occurs more frequently than in the pediatric population.