Critical appraisal of gastric conduit ischaemic conditioning (GIC) prior to oesophagectomy: a systematic review and meta-analysis

Introduction
Anastomotic leaks remain a major complication following oesophagectomy, accounting for high morbidity and mortality. Recently, gastric ischaemic conditioning (GIC) has been proposed to improve anastomotic integrity through neovascularisation of the gastric conduit. This systematic review and meta-analysis aim to determine the impact of GIC on postoperative outcomes following oesophagectomy.

Methods
A systematic literature search was performed to identify studies reporting GIC for any indication of oesophageal resection up to April 25, 2019. The primary outcome was anastomotic leak. Secondary outcomes were conduit necrosis, anastomotic strictures, overall and major complications or in-hospital mortality. Meta-analyses were conducted using random-effects modelling.

Results
Nineteen studies reported on GIC, of which 13 were comparative studies. GIC was performed through ligation in 13 studies and embolisation in six studies. GIC did not appear to reduce anastomotic leakages (OR 0.80, CI₉₅: 0.51–1.24, p = 0.3), anastomotic strictures (OR 0.75, CI₉₅: 0.35–1.60, p = 0.5), overall complications (OR 1.02, CI₉₅: 0.48–2.16, p = 0.9), major complications (OR 1.06, CI₉₅: 0.53–2.11, p = 0.9), or in-hospital mortality (OR 0.70, CI₉₅: 0.32–1.53, p = 0.4). However, GIC was associated with reduced rates of conduit necrosis (OR 0.30, CI₉₅: 0.11–0.77, p = 0.013).

Conclusion
GIC does not appear to reduce overall rates of anastomotic leakage after oesophagectomy but seems to reduce severity of leakages. More in depth studies are recommended.