No abstract

Oxaliplatin (l‐OHP), a platinum‐based drug, is a key chemotherapeutic agent for colorectal cancer (CRC), but drug resistance and toxic effects have been major limitations of its use. Synchrotron radiation X‐ray fluorescence spectrometry (SR‐XRF) is a rapid, nondestructive technique for monitoring the distribution of metals and trace elements in cells or tissue samples. We applied SR‐XRF to visualize the distribution of platinum and other elements in 30 rectal cancer specimens resected from patients who received l‐OHP‐based preoperative chemotherapy and quantified platinum concentration in the tumor epithelium and stroma, respectively, using calibration curves. The platinum concentration in rectal cancer tissue ranged 2.85–11.44 ppm, and the detection limit of platinum was 1.848 ppm. In the tumor epithelium, the platinum concentration was significantly higher in areas of degeneration caused by chemotherapy than in nondegenerated area (p < 0.001). Conversely, in the tumor stroma, the platinum concentration was significantly higher in patients with limited therapeutic responses than in those with strong therapeutic responses (p < 0.001). Furthermore, multivariate analysis illustrated that higher platinum concentration in the tumor stroma was an independent predictive factor of limited histologic response (odds ratio; 19.99, 95% confidence interval; 2.04–196.37, p = 0.013). This is the first study to visualize and quantify the distribution of platinum in human cancer tissues using SR‐XRF. These results suggest that SR‐XRF analysis may contribute to predicting the therapeutic effect of l‐OHP‐based chemotherapy by quantifying the distribution of platinum.

Retrorectal tumors (RT) are uncommon and usually managed by open surgical excision. Laparoscopic excision for RT has been reported in only a small number of papers. We aimed to assess the laparoscopic approach for RT and to discuss the factors that made this procedure difficult. We performed laparoscopic excision using a five-trocar technique for neurogenic RT in three patients. Tumors were successfully excised laparoscopically in two patients. However, the third patient required open conversion because the tumor was strongly adhered to the sacrum and could not be mobilized by dissection, resulting in poor visualization of the dissected site. Laparoscopic excision for RT provides excellent intraoperative visualization and good cosmesis in selected patients, but firm adherence to the sacrum may cause difficulty with this procedure.

A 72-year-old man developed a bulge from the right inguinal region to the scrotum during colonoscopy. The scrotum had swollen to 20 cm in size. From abdominal CT findings, right inguinal hernia in which the greater omentum and the colon had been incarcerated was diagnosed. Since the hernia could not be reduced by manipulation, an emergency operation under general anesthesia was performed. The patient was as extremely obese as the BMI of 35 and his incarcerated hernia was so huge that demanded us to approach to the hernia from a midline laparotomy at the lower abdomen and from the inguinal region. The hernia contained the greater part of the omentum and the transverse colon. The omentum was partially excised ; the contents in the colon were absorbed from a small opening at the injured transverse colon to decompress the pressure within the colon ; and the herniated organs were able to be returned in the abdomen. After closure of the small opening, the inguinal hernia was repaired by the iliopubic tract repair method. He developed respiratory failure after the operation, but it was ameliorated in a short time. Incarcerated hernia as a complication of colonoscopy has rarely been reported so far, and clinical cases of inguinal hernia in which the transverse colon is incarcerated are extremely rare. Accordingly our case is presented here, together with a review of the literature.