Study	Reason for exclusion
Abu‐Own 2000	This is a randomised controlled trial comparing outcomes for participants receiving a Lichtenstein patch repair and a mesh plug repair. It did not compare these outcomes to a non‐mesh technique and hence does not meet the inclusion criteria for this study.
Aigner 2014	This is a prospective, randomised controlled trial comparing outcomes for participants receiving a plug and patch open repair with totally extraperitoneal inguinal hernia repair. It did not compare these outcomes to a non‐mesh technique and hence does not meet the inclusion criteria for this study.
Bay‐Nielsen 2004	This is a post‐hoc retrospective analysis of chronic pain after open mesh versus sutured repair of indirect inguinal hernia repair in young males. The study randomly selected equal numbers of participants who had already received open mesh vs sutured repair of indirect inguinal hernias from the Danish and Swedish Hernia Dabatase Collaboration, and posted a questionnaire for the participants to complete. From the 2612 participants that responded (response rate 80.9%), the study concluded that chronic pain is common after primary inguinal hernia repair in young males, and that there is no difference in the pain associated with open mesh and non‐mesh repair. This study was excluded because it did not meet the inclusion criteria of being a prospective randomised controlled trial.
Chan 2008	This is a non‐randomised prospective study comparing the long‐term outcomes of a non‐mesh suture/tissue‐based complete groin repair and the preperitoneal mesh repair techniques. Two hundred fifty‐six participants were enrolled, with 225 completing 5 years of follow up. Median age was 55 years, and hernias on the right side were more common (63.1%). Concurrent inguinal hernias were found in 115 participants (51%), and 41 (18.2%) had a previous inguinal hernia repair. A complete groin repair was performed in 120 participants and a preperitoneal mesh repair in 78. The remaining had an infrainguinal mesh repair. The overall recurrence rate was 3.1%, with a median time to recurrence of 12 months. There was no significant difference between mesh and suture repairs. Chronic postoperative pain was experienced by 20 participants (8.9%). The study concluded that femoral hernias can be repaired electively with a tissue‐based or a preperitoneal mesh technique, with durable long term results. Mesh repair is indicated for recurrent femoral hernias, inguinofemoral hernias, pre vascular hernias, association with concurrent direct hernias, and, if tension is anticipated, with complete groin repair. Infrainguinal mesh repair is used only when there has been a successful previous inguinal hernia repair. This study was excluded because it did not meet the inclusion criteria of being a randomised prospective controlled trial.
Suradom 2011	This is a non‐randomised prospective study. Its objective is to compare the effectiveness of umbrella made‐mesh plugs compared to other methods of herniorrhaphy. 194 participants were recruited in the study; males aged 16‐86 with a primary diagnosis of an indirect inguinal hernia. Assigned to two periods of elective surgery. First period was between 2003 and 2005, with assignment to either Bassini repair (n = 58) or Bassini repair with umbrella made‐mesh plug (n = 42). The second period was between 2005 and 2008, with assignment to either Lichtenstein repair (n = 40) or umbrella made mesh plug with a patching tail (n = 54). Outcomes measured included mean operating time, duration of hospital stay, complications and recurrence with follow‐up over 2 years. Conclusion that usage of umbrella made mesh plugs was a safe method of groin herniorrhaphy. This study was excluded as it did not meet inclusion criteria of being a randomised controlled trial.