Postoperative morbidity and mortality after surgical resection of small bowel neuroendocrine neoplasms: A systematic review and meta‐analysis

Although small bowel resection is generally considered a low risk gastrointestinal procedure, this might not be true for small bowel neuroendocrine neoplasms (SB‐NEN) as a result of potential central mesenteric involvement. We aimed to determine the reported morbidity and mortality after resection of SB‐NEN in the literature and assess the effect of hospital volume on postoperative morbidity and mortality. A systematic review was performed by searching MEDLINE and Embase in March 2021. All studies reporting morbidity and/or mortality after SB‐NEN resection were included. Pooled proportions of overall morbidity (Clavien‐Dindo I‐IV), severe morbidity (Clavien‐Dindo III‐IV), 30‐day mortality, 90‐day mortality and in‐hospital mortality were calculated, as well as the association with hospital volume (high volume defined as the fourth quartile). Thirteen studies were included, with a total of 1087 patients. Pooled proportions revealed an overall morbidity of 13% (95% confidence interval [CI] = 7%‐24%, I (2) = 90%), severe morbidity of 7% (95% CI = 4%‐14%, I (2) = 70%), 30‐day mortality of 2% (95% CI = 1%‐3%, I (2) = 0%), 90‐day mortality of2% (95% CI = 2%‐4%, I (2) = 35%) and in‐hospital mortality of 1% (95% CI = 0%‐2%, I (2) = 0%). An annual hospital volume of nine or more resections was associated with lower overall and severe morbidity compared to lower volume: 10% vs 15% and 4% vs 9%, respectively. Thirty‐day mortality was similar (2% vs 1%) and 90‐day mortality was higher in high‐volume hospitals: 4% vs 1%. This systematic review with meta‐analyses showed severe morbidity of 7% and low mortality rates after resection of SB‐NEN. The currently available literature suggests a certain impact of hospital volume on postoperative outcomes, although heterogeneity among the included studies constrains interpretation.