Kazuaki Uchimoto

Operating behind denonvilliers' fascia for reliable preservation of urogenital autonomic nerves in total mesorectal excision : A histologic study using cadaveric specimens, including a surgical experiment using fresh cadaveric models

PurposeLittle is known about which urogenital nerves are liable to be injured along surgical planes in front of or behind Denonvilliers’ fascia.Methods and ResultsUsing semiserial histology for five fixed male pelves, we demonstrated that: 1) left/right communicating branches of bilateral pelvic plexuses run immediately in front of Denonvilliers’ fascia; and 2) a lateral continuation of Denonvilliers’ fascia separates the urogenital neurovascular bundle from the mesorectum. Notably, the mesorectum contains no or few extramural ganglion cells. At the level of the seminal vesicles, incision in front of Denonvilliers’ fascia seems likely to injure superior parts of the pelvic plexus and the left/right communication. Moreover, at the prostate level, this incision misleads the surgical plane into the neurovascular bundle. Fresh cadaveric dissections of five unfixed male pelves confirmed that the surgical plane in front of Denonvilliers’ fascia continues to a fascial space for the pelvic plexus containing ganglion cell clusters lateral and/or inferior to the seminal vesicles.ConclusionsTo preserve all autonomic nerves for urogenital function, optimal total mesorectal excision for rectal cancer requires dissection behind Denonvilliers’ fascia.

Adenovirus-Mediated Bcl-Xl Gene Therapy Combined with Pronase Treatment Protects the Small Intestine from Radiation-Induced Enteritis in Mouse Model

Intestinal injury is a major side effect of radiation treatment for many malignancies. The present study investigated whether transducing Bcl-xL, a potent anti-apoptotic gene, into intestinal epithelial cells would exert protective effects against radiation-induced acute injuries. Methods: Adenoviral vectors containing the human Bcl-xL gene (AxCABclxL) or β-galactosidase gene (AxCAlacZ) driven by the CAG promoter were generated. To increase transduction efficiency into the mucosal epithelium, the intraluminal space of the small intestine of mice was washed with buffered-saline and mucus components were digested with Pronase MS®. Gene transduction was performed by injecting 2×108 pfu adenoviral vector into the pre-treated small intestine. Transduction efficiency was examined by X-gal staining 24 hours after AxCAlacZ infection. Radiation-induced acute injury of the small intestine was induced by whole body irradiation (15 Gy) performed 24 hours after adenoviral vector infection. Apoptotic epithelial cells were visualized by TUNEL assay. Morphological analysis was assessed by histological examination. Results: Successful transduction after Pronase MS® treatment was achieved in the basal crypt epithelial cells in the ileum, thought to be the location of stem cells, as determined by X-gal staining. The AxCABclxL group demonstrated significantly fewer radiation-induced apoptotic mucosal epithelial cells when compared with the other two groups at 6 hours after irradiation (p<0.05). At 72 hours after irradiation, the morphological appearance of the small intestine in the AxCABclxL group showed significantly less radiation damage in terms of mucosal thickness (p<0.001). Conclusions: The present study indicates that Bcl-xL gene expression using adenoviral vector-mediated transduction is a valuable approach to prevent intestinal injury caused by radiation exposure.

Local recurrence after rectal endoscopic submucosal dissection: a case of tumor cell implantation

We report a case of local recurrence of cancer after rectal endoscopic submucosal dissection (ESD). A 52-year-old male underwent a curative resection with ESD for rectal intramucosal cancer. Seventy-four months after ESD, surveillance colonoscopy showed an elevated lesion on the ESD scar, suspicious of a recurrence. The patient subsequently underwent a low anterior resection (intersphincteric) with lymph node dissection. Pathology revealed a well-differentiated adenocarcinoma, similar to the ESD specimen. We suspected that the local recurrence was caused by implantation of tumor cells during the ESD, due to surgical manipulation performed with the tumor in an exposed setting for a long period of time.