EHEnda Hannan

Enda Hannan

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article

Previous Organizations / Institutes

The organizations / institutes from the scholar's other articles in the past ten years


Enda Hannan has a total of 109 co-authors. Here are the top co-authors by number of shared publications:

  • Colin Peirce

    Department of Colorectal Surgery, University Hospital Limerick, Limerick, Ireland

    7 shared publications
  • Gerard Feeney

    Department of Colorectal Surgery University Hospital Limerick Dooradoyle Limerick Ireland

    5 shared publications
  • John Calvin Coffey

    Department of Colorectal Surgery University Hospital Limerick Dooradoyle Limerick Ireland

    5 shared publications
  • Mohammad Fahad Ullah

    Department of Colorectal Surgery University Hospital Limerick Dooradoyle Limerick Ireland

    5 shared publications
  • Tim Harding

    St Vincent’s University Hospital

    4 shared publications
  • Desmond Toomey

    Regional Hospital Mullingar, Mullingar, Republic of Ireland

    3 shared publications

Latest Publications

  • Open Access

    Laparoscopic versus open appendicectomy performed by adult general surgeons in pre-teenage years children: a single-centre experience

    by E Hannan, Emy Lim, G Feeney, L O’bRien, Jc Coffey, C Peirce

    The utilisation of laparoscopic appendicectomy (LA) in children remains contentious despite the well-recognised advantages of laparoscopic surgery. The purpose of this study was to compare intraoperative and postoperative outcomes in LA and open appendicectomy (OA) when performed by adult general surgeons outside specialist paediatric practice in younger children. A retrospective review of all patients under the age of 13 who underwent LA for suspected appendicitis over a two-year period was conducted. These were case-matched with an equivalent number of patients who underwent OA during the same period. Intraoperative and postoperative outcomes were compared. Fifty-one patients underwent LA during the study period. Patient demographics were statistically equivalent with the OA cohort. A statistically significant longer median operating time (58 vs 49min) was noted in the LA group, but intraoperative outcomes were otherwise comparable. LA, when compared with OA, was associated with a significant improvement in postoperative length of stay (2 vs 3 days, p < 0.001), postoperative complication rate (0% vs 6%, p = 0.01), negative appendicectomy rate (3.9% vs 17.6%, p < 0.001) and 30-day readmission rate (0% vs 5.9%, p = 0.03). No patients in the LA group required conversion to open surgery. LA can be safely delivered by adult general surgeons to younger paediatric populations outside the setting of paediatric specialist practice, with statistically significant improvements in postoperative outcomes noted when compared with OA. These findings are of importance in the current healthcare context where adult general surgeons continue to perform the majority of paediatric appendicectomies.


  • Open Access

    Surveillance of low‐grade appendiceal mucinous neoplasms for progression to pseudomyxoma peritonei: Results from a structured surveillance programme

    by Enda Hannan, Lorena Martin Roman, Lukas O'BRien, Anna Mueller, Oonagh Staunton, Conor Shields, John Aird, Jurgen Mulsow

    Aim: Low‐grade appendiceal mucinous neoplasm (LAMN) of the appendix is a rare tumour that can progress to pseudomyxoma peritonei (PMP). There is a lack of standardization of surveillance following resection of LAMN as the progression rate to PMP is unclear. The aim of this study was to evaluate the rate of progression following resection of LAMN to PMP in a structured surveillance programme.Method: Data for all patients referred for LAMN surveillance from 2013 to 2021 were retrospectively collected. The surveillance regime consisted of annual CT and tumour markers for a 5‐year period. Patients who progressed to PMP were identified.Results: Of the patients enrolled in surveillance following appendicectomy and LAMN diagnosis (65.1% female, median age 56 years), 83 had completed at least 1 year of surveillance (median follow‐up 24 months). Of these, 6% (n = 5) showed disease progression during follow‐up. The median time to progression was 23 months. Survival analysis revealed no statistically significant difference in progression with regards to T staging (p = 0.39), margin positivity (p = 0.11) or appendiceal perforation (p = 0.26). No patients with Tis disease developed PMP. A statistically significant difference in progression was seen in patients with M1b staging (p = 0.021) and in those with mucin beyond the right iliac fossa at diagnosis (p = 0.04).Conclusion: The observed progression rate justifies the necessity of postappendicectomy surveillance in patients with LAMN, with the risk of progression being highest within the first 3 years of diagnosis. The described surveillance programme allows for early detection of subclinical progression to PMP.


  • Stoma Examination

    by Enda Hannan, Nicholas Johnson, Tim Harding, Ehab A. Mansour

  • Aberrant right posterior sectoral duct injury necessitating liver resection

    by G Bowen, E Hannan, T Harding, D Maguire, At Stafford

    Aberrant insertion of the right posterior sectoral duct is a particularly hazardous variation of biliary anatomy which makes it prone to injury during laparoscopic cholecystectomy Such injuries are challenging to manage, as multiple therapeutic options are available with no clear consensus in the literature for an optimal approach. Options include conservative management, intraoperative ligation of the injured duct, Roux-en-Y reconstruction and segmental liver resection. Most cases in the literature advocate for nonoperative management or hepaticojejunostomy. We present an unusual case of aberrant right posterior sectoral duct injury in which neither of these approaches was viable, necessitating a bi-segmental liver resection.


  • Open Access

    Paediatric robotic surgery: a narrative review

    by Lukas Padraig O’bRien, Enda Hannan, Brice Antao, Colin Peirce

    The benefits of minimally invasive surgery (MIS) compared with traditional open surgery, including reduced postoperative pain and a reduced length of stay, are well recognised. A significant barrier for MIS in paediatric populations has been the technical challenge posed by laparoscopic surgery in small working spaces, where rigid instruments and restrictive working angles act as barriers to safe dissection. Thus, open surgery remains commonplace in paediatrics, particularly for complex major surgery and for surgical oncology. Robotic surgical platforms have been designed to overcome the limitations of laparoscopic surgery by offering a stable 3-dimensional view, improved ergonomics and greater range of motion. Such advantages may be particularly beneficial in paediatric surgery by empowering the surgeon to perform MIS in the smaller working spaces found in children, particularly in cases that may demand intracorporeal suturing and anastomosis. However, some reservations have been raised regarding the utilisation of robotic platforms in children, including elevated cost, an increased operative time and a lack of dedicated paediatric equipment. This article aims to review the current role of robotics within the field of paediatric surgery.


  • Open Access

    Robotic colorectal surgery in elderly patients: A single‐centre experience

    by Enda Hannan, Gerard Feeney, Mohammad Fahad Ullah, Eoghan Condon, John Calvin Coffey, Colin Peirce

    Introduction: The purpose of this study was to evaluate outcomes in elderly patients (age ≥ 65 years) undergoing robotic colorectal surgery (RCRS) in comparison with non‐elderly patients.Materials and Methods: Data was collected on elderly and non‐elderly patients who underwent RCRS from a prospectively maintained database.Results: A total of 89 elderly and 73 non‐elderly patients were identified. No statistically significant differences in postoperative complication, reoperation, wound infection, anastomotic leak or mortality were observed. The median length of stay was 1 day longer in elderly patients (p = 0.007). Subgroup analysis of octogenarians demonstrated outcomes that compared favourably with younger patients.Conclusion: RCRS in elderly patients is safe and effective, with outcomes that do not differ significantly with younger patients. Older age should not be considered to be a specific exclusion criteria for RCRS. To our knowledge, this study represents the largest in the literature to examine outcomes specifically in elderly patients undergoing RCRS.


  • Open Access

    Left-sided appendicitis in intestinal malrotation: a minimally invasive approach

    by Gerard Feeney, Enda Hannan, Mohammed Alagha, Yasser Abdeldaim

    Intestinal malrotation is a rare clinical entity that occurs in 1/6000 live births. Acute appendicitis (AA) is commonly recognized clinically by migratory right iliac fossa pain. We present a rare case of AA in a patient with previously undiagnosed IM that posed a diagnostic challenge due to abnormal caecal location, which was managed by a laparoscopic approach. The presence of undiagnosed congenital anomalies such as IM can render diagnosis of even seemingly straightforward conditions such as AA challenging, meaning that the presence of classical clinical findings cannot always be relied upon. One should have a low threshold for performing cross-sectional imaging in cases where clinical findings do not yield a satisfactory diagnosis. The adult patient with AA in the context of incidental type 1 IM can be managed laparoscopically by a simple modification of standard technique, without the need to correct malrotation, thus allowing the patient to benefit minimally invasive surgery.


  • Open Access

    Laparoscopic paediatric inguinal hernia repair: lessons learned from 102 cases

    by Lukas O’bRien, Enda Hannan, Sinead Hassett

    Introduction: Paediatric inguinal hernias (IHs) are common. The first paediatric laparoscopic hernia repair was described by El-Gohary and colleagues in the United Arab Emirates in 1993. Both laparoscopic inguinal hernia repair (LIHR) and open repair still exist concurrently with no consensus on gold standard treatment at present. The purpose of this study was to retrospectively evaluate our initial experience with LIHR in paediatric patients. Methods: A retrospective observational cohort study of all paediatric patients that underwent LIHR in our institution was performed. Intraoperative and postoperative outcomes were examined. Results: During the study period, 102 patients were scheduled for LIHR. The majority (76.5%) were male with a median age of 5 months. Thirty two patients (31.4%) were neonates at the time of surgery. The majority of cases (83.3%) were elective procedures. There were no instances of intraoperative vascular or visceral injury. Most patients underwent surgery as a day case. Eighteen patients underwent bilateral LIHR. The recurrence rate was 1.9%. These occurred in the first two patients to undergo LIHR, after which no recurrences were observed following a modification of the technique. The overall complication rate was 7.1%, most of which were managed conservatively. Conclusion: Paediatric LIHR is a safe, feasible and effective procedure that is associated with a short inpatient length of stay, a low recurrence rate and low postoperative complication rate. The technique is versatile and can be used to treat both elective and emergency presentations with IH in a wide age range.