Chronic pain and foreign body sensation based on mesh placement in primary ventral hernia repair: a systematic review highlighting the evidence gap and a call to action.

Purpose: This systematic review aimed to investigate differences in chronic pain and foreign body sensation based on mesh placement, with recurrence as a secondary outcome.

Methods: The review was registered in PROSPERO (ID: CRD42024592114), and searches were conducted in MEDLINE (PubMed), Embase Ovid, and Cochrane CENTRAL on October 3rd, 2024. Studies were included if they compared mesh placements, categorized as onlay, retromuscular, preperitoneal, or intraperitoneal onlay mesh (IPOM), in primary ventral hernia repairs in adults. Chronic pain (≥ 6 months post-surgery) and foreign body sensation were the primary outcomes. Randomized controlled trials (RCTs) and cohort studies were included, while incisional hernias alone and animal studies were excluded. Risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies and Cochrane Risk of Bias 2 (RoB2) tool for RCTs. Due to significant heterogeneity, a meta-analysis was not feasible, and a narrative synthesis was provided.

Results: A total of 6,562 records were screened, of which nine cohort studies and one RCT were included. Studies were heterogeneous and many did not aim to assess chronic pain as the primary outcome. Two studies reported significantly lower chronic pain rates with retromuscular mesh placement, but data pooling was not possible. Foreign body sensation could not be assessed because the only study reporting on this did not have extractable data.

Conclusion: Currently, there is insufficient evidence to favor one mesh placement over another for chronic pain or foreign body sensation. While crude rates suggest that retromuscular and preperitoneal placements may result in less chronic pain than onlay and IPOM, the evidence remains very uncertain due to significant clinical and methodological heterogeneity. Further research is warranted.