Nobuyuki Sakurazawa

Roles of inducible nitric oxide synthase in the development and healing of experimentally induced gastric ulcers

Summary.  The roles of inducible nitric oxide synthase (iNOS) in the development and healing of gastric ulcers have not been fully characterized. We characterized iNOS expression in experimentally induced ulcers in rat and mouse stomachs and investigated the roles of iNOS using iNOS gene‐deficient (iNOS–/–) mice and wildtype mice. Gastric ulcers were induced in rats and mice by the application of acetic acid and cryoinjury, respectively. iNOS expression was detected on days 1–7 and peaked 3 days after ulcer induction in the rat. iNOS‐positive cells were distributed mainly among the infiltrating cells and fibroblasts in the ulcer bed. The almost similar courses of healing and iNOS expression were observed in the ulcers of mice. During the course of healing, the iNOS gene status did not affect cell proliferation in the healing zone or vessel formation in the ulcer bed. iNOS deficiency, however, caused larger ulcers and severer inflammation during ulcer healing; the clearance of inflammatory cells in the ulcer bed by apoptosis was also delayed when the ulcer was re‐epithelialized in the iNOS‐deficient mice. These results indicate that iNOS is expressed in the ulcer bed and that iNOS activity may play beneficial roles in the ulcer repair process, possibly by regulating inflammation.

Isoperistaltic versus antiperistaltic stapled side-to-side anastomosis for colon cancer surgery: a randomized controlled trial.

BACKGROUND Isoperistaltic stapled side-to-side anastomosis (SSSA), which is a modified technique from conventional antiperistaltic SSSA, has the benefits of antiperistaltic SSSA but requires less intestinal mobility. The aim of this randomized controlled trial was to evaluate short-term outcomes of isoperistaltic SSSA comparing them with antiperistaltic SSSA during colon cancer surgery. MATERIALS AND METHODS We conducted a randomized controlled trial of patients with colon cancer who underwent elective curative resection and had enough intestinal mobility at anastomosis. The primary outcome was the presence of anastomotic failure, including leakage, hemorrhage, and stenosis. RESULTS Between July 2012 and January 2014, forty patients were enrolled (20 patients in each group). The study was suspended on detecting excess morbidity in the isoperistaltic SSSA group. No significant differences were observed in all preoperative backgrounds between the two groups. Anastomotic leakage was seen in two patients in the isoperistaltic SSSA group, compared with none in the antiperistaltic SSSA group, although the difference was not statistically significant (P = 0.487). One patient in the antiperistaltic SSSA group had anastomotic stenosis, which improved conservatively, compared with none in the isoperistaltic SSSA group (P = 1.000). No anastomotic hemorrhage was seen in either group. There was no significant difference in the median postoperative hospital stay (P = 0.313). CONCLUSIONS This study did not show any short-term advantage or disadvantage of isoperistaltic SSSA compared with that of antiperistaltic SSSA. However, considering that anastomotic leakage occurred only in the isoperistaltic SSSA group, additional modifications are recommended to perform safe isoperistaltic SSSA for colon surgery.

Supportive techniques and devices for endoscopic submucosal dissection of gastric cancer

The indications for endoscopic treatment have expanded in recent years, and relatively intestinal-type mucosal stomach carcinomas with a low potential for metastasis are now often resected en bloc by endoscopic submucosal dissection (ESD), even if they measure over 20 mm in size. However, ESD requires complex maneuvers, which entails a long operation time, and is often accompanied by complications such as bleeding and perforation. Many technical developments have been implemented to overcome these complications. The scope, cutting device, hemostasis device, and other supportive devices have been improved. However, even with these innovations, ESD remains a potentially complex procedure. One of the major difficulties is poor visualization of the submucosal layer resulting from the poor countertraction afforded during submucosal dissection. Recently, countertraction devices have been developed. In this paper, we introduce countertraction techniques and devices mainly for gastric cancer.

Inducible nitric oxide synthase activity induced by sodium chloride solution prolongs luminal pH elevation in rat and mouse stomachs.

Background:  Sodium chloride (NaCl) is a strong promoter of gastric cancer. We hypothesized that inducible nitric oxide synthase (iNOS) induced by NaCl may be involved in its promoting effects. We investigated iNOS expression by hypertonic NaCl solutions and its pathophysiological roles in the gastric mucosa of rats and mice.

Laparoscopic mesh repair for lumbar hernia after iliac crest bone harvest

Lumbar hernia after iliac crest bone harvest is relatively rare. When it does occur, it presents as a flank abdominal protrusion through a lateroposterior abdominal wall defect. A laparoscopic approach for this type of hernia is reported to have advantages over the classic open method. Here, we present a case of a 49‐year‐old Caucasian man who presented with an enlarged left flank mass after iliac bone harvest for pseudarthrosis. He had undergone open onlay mesh repair for inferior lumbar hernia, but the hernia recurred 3 months postoperatively. Laparoscopic intraperitoneal onlay mesh repair using a composite mesh was performed 7 months after recurrence. The patient was discharged 6 days postoperatively without complications. No signs of recurrence were detected during 1‐year follow‐up period. The laparoscopic approach for lumbar hernia conferred excellent visualization of the hernia defect and enabled a safe mesh repair using intra‐abdominal pressure to hold it in position. This approach provided all the benefits of minimally invasive surgery.

Lysophosphatidylcholine as a predictor of postoperative complications after colorectal cancer surgery

PurposeLysophosphatidylcholine (LPC), which is generated from phosphatidylcholine (PC) and metabolized by autotaxin (ATX), modulates immune responses via its anti-inflammatory property. We investigated the association between LPC and postoperative complications (POCs) after colorectal cancer surgery (CRC).MethodsThe subjects of this study were 43 patients who underwent surgery for CRC. Peripheral blood samples were collected preoperatively and immediately after surgery, and on postoperative days (PODs) 1, 3, 5, and 7. Patients were divided into a No-POC group (n = 33) and a POC group (n = 10). Blood LPC, IL-6, PC, and ATX levels were measured by specific enzymatic assays or ELISA.ResultsThe postoperative to preoperative LPC ratios were lowest on POD 1 in both groups. The POC group had significantly lower LPC ratios throughout the perioperative period than the No-POC group. The LPC ratios were inversely correlated with IL-6. The predictive impact of LPC ratios on POCs was demonstrated by ROC analysis (cut-off 51.2%, AUC 0.798) and multivariate analysis (OR 15.1, P = 0.01). The postoperative PC ratios decreased more after surgery in the POC group. ATX levels did not change significantly in either group.ConclusionsDecreased postoperative LPC is associated with increased postoperative inflammatory response and POCs. The decreased PC supply to the circulation is a mechanism of the postoperative LPC decrease.

Life-threatening hemorrhage from the corona mortis after laparoscopic inguinal hernia repair: Report of a case

Along with the increased use of other laparoscopic procedures, laparoscopic inguinal hernia repair has become widely used because of its minimally invasive nature. Here, we report a case of 66‐year‐old man who underwent transabdominal preperitoneal laparoscopic hernioplasty and developed hemorrhagic shock on postoperative day 1. CT showed postoperative venous hemorrhage from the retropubic space. Successful hemostasis of the massive hemorrhage was achieved laparoscopically. The origin of the hemorrhage was assumed to be the corona mortis vein, which was slightly injured during the operation. Despite the rarity of this complication, surgeons must be aware of the need to carefully dissect and fix the mesh in the retropubic space to avoid injuring the corona mortis. Laparoscopic hemostasis may be an effective alternative to the open approach.

Colonic stent-induced mechanical compression may suppress cancer cell proliferation in malignant large bowel obstruction

BackgroundThe short-term safety and efficacy of insertion of a self-expandable metallic colonic stent (SEMS) followed by elective surgery, “bridge to surgery (BTS)”, for malignant large bowel obstruction (MLBO) have been well described; however, the influence on long-term oncological outcomes is unclear. The aim of this study was to evaluate changes in oncological characteristics in colorectal cancer (CRC) tissues after SEMS insertion, focusing on growth factors, cell cycle and apoptosis.MethodsFrom January 2013 to September 2014, a total of 25 patients with MLBO who underwent BTS at our single institution were retrospectively included. Paired CRC tissue samples before (endoscopic biopsy) and after SEMS insertion (surgically resected) were collected from each patient. EGFR, VEGF, Ki-67, p27kip1 and TUNEL expression were determined by immunohistochemistry.ResultsNo clinical or subclinical perforations evaluated by mechanical ulceration pathologically were observed. Epithelial exfoliation, tumour necrosis, infiltration of inflammatory cells and fibrosis were observed in SEMS-inserted surgically-resected specimens. Overall, 84% (21/25) and 60% (15/25) of patients exhibited no change or a decrease in staining category, respectively, for EGFR and VEGF expression after SEMS insertion. A significant decrease in Ki-67 expression was observed in surgically-resected specimens compared with endoscopic biopsy specimens (P < 0.01). The upstream cell cycle inhibitor, p27kip1, was significantly increased after SEMS insertion (P = 0.049).ConclusionsAlthough the long-term safety of BTS should be determined in a future clinical trial, mechanical compression by SEMS may suppress cancer cell proliferation and this result could provide some insights into the issue.

Placement of a self-expandable metallic stent as a bridge to surgery for large bowel obstruction induced by effective neoadjuvant therapy: report of three cases

BackgroundSelf-expandable metallic stent placement is a widely performed palliative procedure or bridge to surgery for obstructive colorectal cancer. However, the feasibility of this procedure for large bowel obstruction induced by effective neoadjuvant therapy is unclear.Case presentationWe herein report three such cases involving a 61-year-old man who underwent neoadjuvant chemoradiotherapy for lower rectal cancer, a 56-year-old woman who underwent neoadjuvant chemotherapy for lower rectal cancer, and a 63-year-old woman who underwent neoadjuvant chemotherapy for lower rectal cancer. All were emergently hospitalized with large bowel obstruction that developed while undergoing neoadjuvant therapy. Colonoscopy revealed smooth strictures caused by effective neoadjuvant therapy. Self-expandable metallic stents were placed across the obstruction as a bridge to surgery, and laparoscopic low anterior resection was uneventfully performed in all patients.ConclusionsWe successfully treated three patients with large bowel obstruction induced by a good response to neoadjuvant therapy using self-expandable metallic stents as a bridge to surgery. Further studies with larger sample sizes are warranted to assess the feasibility of this strategy.

Laparoscopic transabdominal preperitoneal repair for strangulated inguinal hernia

Laparoscopic transabdominal preperitoneal repair (TAPP) is widely accepted in elective inguinal hernioplasty. However, given the scarcity of data, the feasibility and safety of TAPP in strangulated hernia cases have not yet been determined.