Tumor localization using carbon nanoparticles for laparoscopic colectomy

Jun Yan¹, Yu Zheng¹, Zhangyuanzhu Liu¹, Xiufeng Wu², Fangqing Xue¹, Xiaoling Zheng¹, Wenju Liu¹, Hong Shi², Wei Gong¹, Guoxin Li¹. ¹Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510515, P.R.China, ²Department of Surgery, Fujian Provincial Tumor Hospital, Teaching Hospital of Fujian Medical University, Fuzhou, Fujian, 350014, P.R.China

Background: Accurate tumor localization is critical to performing laparoscopic colectomy which is lack of tactile sensation. The purpose of this study was to evaluate the feasibility and safety of using carbon nanoparticles to localize non-palpable tumor for laparoscopic colectomy, compared with intra-operative colonoscopy.

Methods: A prospective study was performed between July 2012 and September 2015. Inclusion criteria included T1-3 colon cancer, big adenoma or polyp unsuitable for endoscopic resection, multiple colorectal tumors, and cancer complete or partial response after neoadjuvant therapy. Exclusion criteria included T4 colon cancer, planned local excision, previous abdominal surgery, and emergency case with bleeding or obstruction or perforation. Sixty patients were enrolled in this study and divided into carbon nanoparticles group (30 cases) and intra-operative colonoscopy group (30 cases). One milliliter carbon nanoparticles suspension, which is approved by Chinese Food and Drug Administration, was endoscopically injected into the submucosal layer at four points around the tumor one day before surgery in carbon nanoparticles group. Laparoscopic colectomy was performed. Patients' perioperative clinical and pathological data were compared between two groups.

Results: Both groups were comparable in age, sex distribution, American Society of Anesthesiologists (ASA) score, body mass index (BMI), technique performed, tumor size, and tumor location. In carbon nanoparticles group, tumor area was black-dyed by carbon nanoparticles and easily identified during laparoscopic colectomy. No patient had any side effects of carbon nanoparticles in this study. All tumors were correctly localized in two groups. However, the operative time was significant short and convertion rate was significant low in carbon nanoparticles group, compared with intra-operative colonoscopy group. Moreover, more lymph nodes were harvested in carbon nanoparticles group. There were no differences between groups regarding hospital stay and postoperative complication rates.

Conclusions: It is feasible to use carbon nanoparticles to localize non-palpable tumor for laparoscopic colectomy. Carbon nanoparticles suspension is safe for submucosal injection.