Sebastian Mitchell

Dr. Sebastian Mitchell

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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17 June 2023 in Chest
Verified
Journal Article
Open access
ARAndrew I. Ritchie
Andrew I. Ritchie
ASAran Singanayagam
Aran Singanayagam
SMSebastian Mitchell
Sebastian Mitchell
JWJadwiga A. Wedzicha
Jadwiga A. Wedzicha
ASAnand Shah
Anand Shah
CBChloë I. Bloom
Chloë I. Bloom
Inhaled corticosteroids (ICS) increase the risk of pneumonia in COPD and commonly are used in patients with COPD-bronchiectasis overlap. Is the risk of pneumonia associated with ICS further heightened in COPD-bronchiectasis? Electronic health care records (from 2004-2019) were used to obtain a cohort of patients with COPD and a nested case-control group (age and sex matched 1:4). Analyses were conducted to determine the risk of hospitalization for pneumonia in COPD associated with ICS use in those with bronchiectasis. Findings were confirmed by several sensitivity analyses. Additionally, a smaller nested case-control group containing only patients with COPD-bronchiectasis overlap and those with recent blood eosinophil counts (BECs) was used to determine any association with BEC. Three hundred sixteen thousand six hundred sixty-three patients were eligible for the COPD cohort; bronchiectasis significantly increased the risk of pneumonia (adjusted hazard ratio, 1.24; 95% CI, 1.15-1.33). In the first nested case-control group of 84,316 patients with COPD, ICS was found to increase the odds of pneumonia (adjusted OR [AOR], 1.26; 95% CI, 1.19-1.32) only if used in the previous 180 days. However, bronchiectasis was a significant modifier such that ICS use did not augment further the already elevated bronchiectasis-associated pneumonia risk (COPD-bronchiectasis: AOR, 1.01; 95% CI, 0.8-1.28; no bronchiectasis: AOR, 1.27; 95% CI, 1.20-1.34). Several sensitivity analyses and a second smaller nested case-control group confirmed these findings. Finally, we found that BEC modified the ICS-associated pneumonia risk in COPD-bronchiectasis overlap, where lower BEC was associated significantly with pneumonia (BEC ≤ 3 × 109/L: AOR, 1.56; 95% CI, 1.05-2.31; BEC > 3 × 109/L: AOR, 0.89; 95% CI, 0.53-1.24). ICS use does not augment further the already increased risk of hospitalization for pneumonia associated with concomitant bronchiectasis in patients with COPD.

Verified
Journal Article
Open access
PDF file
SMSebastian Mitchell
Sebastian Mitchell
DWDiana Wu
Diana Wu
MCMichael Cheah
Michael Cheah
PMPeter Mekhail
Peter Mekhail
SNShayanthan Nanthakumaran
Shayanthan Nanthakumaran
ARAndrew G Robertson
Andrew G Robertson
Background/Objectives: Obesity is extremely common among patients with end stage renal disease (ESRD) due to shared metabolic risk factors. Renal transplantation is the gold standard treatment for ESRD, however obesity is a major barrier due to increased anaesthetic risks, surgical complications and poorer graft outcomes. The aim of this study was to assess ESRD patients referred for metabolic bariatric surgery (MBS) in Scotland. Methods: Data from all adult patients with ESRD who were referred for MBS in Scotland from January 2014 to August 2025 were obtained retrospectively. Categorical data are presented as number and percentage; non-parametric continuous data are presented as median and inter-quartile range. A focused review of comparable published cohorts was performed for context. Results: A total of 9 patients with ESRD were referred for MBS over the study period; of these, 5 patients went on to have MBS. Of the patients who underwent MBS, the median age at referral was 47 years, 3 of 5 were female and the median starting weight and body mass index (BMI) were 131 kg and 49 kg/m2 respectively. Four patients underwent laparoscopic sleeve gastrectomy, and 1 patient underwent one-anastomosis gastric bypass. The median length of hospital stay was 2 days. The median total percentage weight loss was 33.5% (range 27.7% to 48.1%). Four of the five patients were able to be activated on the transplant waiting list after successfully achieving their target weight after a median of 8.4 months. Of the 4 listed patients, 3 were transplanted with no post-operative complications, and 1 remains active on the waiting list. Across seven comparable cohorts (19 to 198 operated patients), all single- or two-centre, ours had the only national coverage. Listing and transplantation outcomes (4 of 5 listed, 3 of 5 transplanted) were broadly consistent with the range reported in these cohorts, although the small sample precludes formal comparison. Conclusions: In this small case series and review, MBS appeared safe and feasible in a highly selected group of patients with obesity and ESRD. MBS facilitates access to renal transplant but is under-utilised in Scotland. We plan to formalise a national treatment pathway to streamline access to bariatric services for patients with ESRD and enable more patients to undergo renal transplantation.

13 September 2025 in Annals of Plastic Surgery
Verified
Journal Article
Closed access
TNThendo Netshiongolwe
Thendo Netshiongolwe
SMSebastian Mitchell
Sebastian Mitchell
SKSenthooran Kathiravelupillai
Senthooran Kathiravelupillai
PSPraveen Subbiah
Praveen Subbiah
MZMing Zien
Ming Zien
AKAnkur Khajuria
Ankur Khajuria
Background: The field of gender-affirming surgery is rapidly evolving, with plastic surgery units worldwide increasingly offering these services. Phalloplasty is a critical component of female-to-male (FTM) transition, providing significant psychological and functional benefits. Although robust comparative trials are scarce, expert consensus favors the radial forearm free flap (RFF) when feasible. This systematic review directly compares outcomes of pedicle anterolateral flap (pALT) and the RFF in FTM gender-affirming surgery. Methods: A systematic review was conducted following the PRISMA guidelines, searching PubMed/Medline, Scopus, Web of Science, ProQuest, and EBSCO for eligible studies. Two independent reviewers screened and selected studies, resolving discrepancies by consensus. Flap survival and patient satisfaction were the primary outcome measures. Secondary outcomes included standing voiding ability, penetrative sexual function, number of operative stages, surgical duration, anesthetic techniques, and donor site morbidity or acceptance. Risk of bias was assessed using ROBINS-I, and evidence quality was evaluated using GRADE. Results: A total of 19 studies comprising 769 patients (614 RFF, 155 pALT) were included. Both techniques demonstrated comparable outcomes, although the ALT required significantly less operative time (RFF vs pALT, 290 vs 516 minutes). Flap failure rates were low for both groups (1.9% RFF, 0.6% pALT; P = 0.348), and patient satisfaction was high (78% RFF vs 76.2% pALT; P = 1.0). Risk of bias assessment indicated serious selection bias due to the observational nature of studies. GRADE evaluation rated the evidence as low, reflecting the absence of randomized trials in this field. Conclusions: The RFF remains the most reliable technique for phalloplasty, with the pALT serving as a secondary option when the RFF is not feasible. However, the limited number of studies and the lack of standardized outcome reporting in gender-affirming surgery make it difficult to draw definitive conclusions or establish evidence-based recommendations. Although both flap types are considered safe for female-to-male phalloplasty, the small patient cohorts and absence of randomized data contribute to the ongoing uncertainty in determining the optimal approach.

24 December 2025 in Journal of Plastic, Reconstructive & Aesthetic Surgery
Verified
Journal Article
Closed access
KDKian Daneshi
Kian Daneshi
SMSebastian Mitchell
Sebastian Mitchell
VLVivienne Lewis
Vivienne Lewis
PBPanagiotis Bompolas
Panagiotis Bompolas
KKKiamehr Karagah
Kiamehr Karagah
VGVimal J. Gokani
Vimal J. Gokani

19 February 2026 in Aesthetic Plastic Surgery
Verified
Journal Article
Closed access
PDF file
SMSebastian Mitchell
Sebastian Mitchell
YYYousif F. Yousif
Yousif F. Yousif
MZMing Zien
Ming Zien
YMYasin Omer Memisoglu
Yasin Omer Memisoglu
NANoor Al-Bassam
Noor Al-Bassam
AKAnkur Khajuria
Ankur Khajuria

27 July 2026 in Scientific Reports
Verified
Journal Article
Open access
PDF file
SMSebastian Mitchell
Sebastian Mitchell
RGRyan Gidda
Ryan Gidda
JLJames Lucocq
James Lucocq
GGGeorgios Geropoulos
Georgios Geropoulos
DCDanielle Clyde
Danielle Clyde
ARAndrew G Robertson
Andrew G Robertson
Obesity is associated with breast cancer risk, and metabolic bariatric surgery (MBS) may reduce obesity-related cancer incidence. Prior reviews suggest lower breast cancer incidence after MBS, but uncertainty remains across design, menopausal status, procedure type, and confounding control. We conducted a PROSPERO-registered systematic review (CRD420261384078), meta-analysis, and network meta-analysis according to PRISMA. PubMed, Embase/MEDLINE, and Scopus were searched for comparative studies of breast cancer incidence after MBS versus control. Risk of bias was assessed using ROBINS-I and certainty using GRADE. Seventeen studies including 343,531 surgical patients and 1,587,413 controls were included. MBS was associated with lower breast cancer incidence in the primary hazard-ratio analysis (HR 0.75, 95% CI 0.70–0.81; I2 = 0%) and women-only cohorts (HR 0.74, 95% CI 0.67–0.81). Propensity-score-matched analyses showed a larger but heterogeneous association (RR 0.56, 95% CI 0.31–0.99; I2 = 91%). Premenopausal estimates favoured MBS (HR 0.74, 95% CI 0.60–0.91), whereas postmenopausal estimates were not significant (HR 0.73, 95% CI 0.50–1.07). Network estimates favoured sleeve gastrectomy and Roux-en-Y gastric bypass versus control, but no procedure was superior. Certainty ranged very low-to-moderate overall. MBS may be associated with lower breast cancer incidence, but evidence remains observational; future work must clarify causality, patient selection, and procedure effects.