Laparoscopic approach for abdominal neuroblastoma in Japan: results from nationwide multicenter survey.

Background: Some neuroblastoma (NB) cases are suitable for minimally invasive surgery (MIS), but indication and technical issue are unclear. We assessed the current status of MIS for abdominal NB after mass screening period in Japan.

Methods: Preliminary questionnaires requesting the numbers of NB cases that underwent MIS from 2004 to 2016 were sent to 159 Japanese institutes of pediatric surgery. The secondary questionnaires were then sent to the institutions that reported MIS cases of NB in order to collect detailed data.

Results: One hundred and thirty-four (84.2%) institutions responded to the preliminary questionnaires, and 83 (52.2%) reported managing operative cases. The total number of operative cases was 1496. MIS was performed for 175 (11.6%) cases, of which the completed forms of 140 patients were returned, including 100 abdominal NB cases. The male/female ratio was 51/49. Forty-seven cases underwent a laparoscopic biopsy, and 2 (4.3%) cases were converted to laparotomy due to bleeding. Sixty-five cases underwent MIS for radical resection, and 7 (10.8%) were converted to laparotomy. The reasons for open conversion were bleeding and severe adhesion. Regarding open conversion, there were no significant relationships between conversion and neo-adjuvant chemotherapy, biopsies, stage, size, or MYCN amplification. We found no relationship between resectability and vascular encasement in this study. There was relationship between the resected tumor size and the patients' height, which was expressed using the following formula: [Formula: see text] (x, patients height, y, tumor size; p = 0.004219, SE: 1.55566). Postoperative complications after radical resection were recognized in 7 (10.8%) cases.

Conclusions: MIS was performed in limited cases of abdominal NB. A laparoscopic biopsy with careful attention to bleeding is feasible. The resected tumor size was shown to correlate with the patients' height. Tumor size within 6 cm of maximum diameter can be resected safely.