The Need for Centralization for Small Intestinal Neuroendocrine Tumor Surgery: A Cohort Study from the GTE-Endocan-RENATEN Network, the CentralChirSINET Study.

BACKGROUND: The concept of surgical centralization is becoming more and more accepted for specific surgical procedures. OBJECTIVE: The aim of this study was to evaluate the relationship between procedure volume and the outcomes of surgical small intestine (SI) neuroendocrine tumor (NET) resections. METHODS: We conducted a retrospective national study that included patients who underwent SI-NET resection between 2019 and 2021. A high-volume center (hvC) was defined as a center that performed more than five SI-NET resections per year. The quality of the surgical resections was evaluated between hvCs and low-volume centers (lvCs) by comparing the number of resected lymph nodes (LNs) as the primary endpoint. RESULTS: A total of 157 patients underwent surgery in 33 centers: 90 patients in four hvCs and 67 patients in 29 lvCs. Laparotomy was more often performed in hvCs (85.6% vs. 59.7%; p < 0.001), as was right hemicolectomy (64.4% vs. 38.8%; p < 0.001), whereas limited ileocolic resection was performed in 18% of patients in lvCs versus none in hvCs. A bi-digital palpation of the entire SI length (95.6% vs. 34.3%, p < 0.001), a cholecystectomy (93.3% vs. 14.9%; p < 0.001), and a mesenteric mass resection (70% vs. 35.8%; p < 0.001) were more often performed in hvCs. The proportion of patients with ≥8 LNs resected was significantly higher (96.3% vs. 65.1%; p < 0.001) in hvCs compared with lvCs, as was the proportion of patients with ≥12 LNs resected (87.8% vs. 52.4%). Furthermore, the number of patients with multiple SI-NETs was higher in the hvC group compared with the lvC group (43.3% vs. 25.4%), as were the number of tumors in those patients (median of 7 vs. 2; p < 0.001). CONCLUSIONS: Optimal SI-NET resection was significantly more often performed in hvCs. Centralization of surgical care of SI-NETs is recommended.

Unifocal versus Multiple Ileal Neuroendocrine Tumors Location: An Embryological Origin.

INTRODUCTION: Small-intestinal neuroendocrine tumors (SI-NET) are situated preferentially within the ileum. The aim was to describe a potential difference in location between unifocal and multiple ileal-NET. PATIENTS AND METHODS: Between December 2010 and December 2019, all consecutive patients who underwent resection in our European Neuroendocrine Tumor Society Center of Excellence, of at least 1 non-duodenal SI-NET, were retrospectively included. The main objective was to prove that multiple ileal-NET were mostly located on the left side of the superior mesenteric artery (SMA) axis (defined as 40 cm from the ileocecal valve), and unifocal ones on the right side. RESULTS: Ninety-four patients were included, 6 with unifocal jejunal-NET located 35 cm (range, 10-60) from the duodenojejunal angle (DJA), 44 (47%) with unifocal ileal-NET and 44 (47%) with multiple ileal-NET. The median number of tumors in multiple ileal-NET was 7 (range, 2-95), within a median small bowel segment of 105 cm (10-240). The median length between the proximal tumor and the DJA was 428 cm (300-635) and 540 cm (350-725) for the distal one; 40 (91%) of them were located on the left side of the SMA axis. In contrast, unifocal ileal-NET were located at a median distance of 577 cm (305-820) from the DJA (p < 0.001, compared to multiple ileal-NET); 30 (68%) of them were on the right side of the SMA axis (p < 0.001). CONCLUSION: Multiple ileal-NET are mostly located on the left side of the SMA axis. Further studies are warranted to explore the embryological origin of unifocal versus multiple ileal-NET.