Takenori Hayashi

How Can We Control Intraoperative Bacterial Contamination and Surgical-Site Infection During an Anterior Resection or Hartmann’s/Miles’ Operation?

PurposeIntraoperative bacterial contamination (IBC) is a major cause of surgical-site infection (SSI). Therefore, we investigated whether the ingenuity of surgical procedures could reduce the incidence of IBC/SSI.MethodsSixty patients who were surgically treated for recto-sigmoid cancer were investigated. Among these patients, the colon was transected during the early perioperative period (ET) in 29 patients and during the late period (LT) in 31 patients. Three samples for IBC were obtained from the irrigation fluid before abdominal closure (LAVAGE), the remaining cut sutures after peritoneal closure (SUTURE), and a subcutaneous swab of the wound (SUBCUT).ResultsThe overall SSI and IBC rates were 25% and 55.2%, respectively. Patients who developed SSI had an extremely high IBC rate (85%), and IBC patients also had a high SSI rate (68%). IBC was highest in the LAVAGE (26%) followed by the SUBCUT (26%), and the SUTURE (12%). The incidence of IBC in the LT was significantly lower than that in the ET (19% vs. 55%, p < 0.01), although the incidence of SSI was similar in both IBC groups.ConclusionShortening the exposure of the colonic mucosa decreased the incidence of IBC/SSI; thus, careful operations to minimize IBC are recommended.

Increased Lymphatic Vessels in Patients with Encapsulating Peritoneal Sclerosis

♦ Background: The angiogenic response is partly involved in the progression of encapsulating peritoneal sclerosis (EPS). However, the details of the angiogenic response, especially for lymphatic vessels in patients with EPS, remain unclear. In addition, because of technical limitations, morphology studies reported to date have examined only the parietal peritoneum. The morphologies of parietal and visceral lymphatic vessels in patients with EPS both need to be analyzed. ♦ Methods: We examined peritoneal samples from 18 patients with EPS who underwent enterolysis of the visceral peritoneum and compared them with samples from 17 autopsy cases (controls). To examine the angiogenic response, we performed immunohistochemistry for the endothelial markers CD34 (blood vessels) and podoplanin (lymphatic vessels) and for the cell proliferation marker Ki-67. Immunogold electron microscopy analysis for podoplanin was also performed. In 7 of 18 cases, we compared differences in the angiogenic response of the parietal and visceral peritoneal membranes. ♦ Results: Angiogenic responses were more frequent in the compact zone than in regenerated layers. The number of capillaries positive for anti-CD34 and anti-podoplanin monoclonal antibodies per unit area of visceral peritoneal tissue was, respectively, 41.1 ± 29.3/mm2 in EPS patients and 2.7 ± 4.4/mm2 in controls (p ≤ 0.01) and 48.1 ± 43.9/mm2 in EPS patients and 4.1 ± 5.4/mm2 in controls (p ≤ 0.01). The percentage of capillaries positive for anti-Ki-67, CD34, and podoplanin was 4.6% in EPS patients (p ≤ 0.01) and 0.8% in controls (p = 0.09). The immunogold electron microscopy analysis revealed that podoplanin was localized to endothelial cells with anchoring filaments, a specific feature of lymphatic vessels. Furthermore, compared with parietal peritoneal membrane, visceral peritoneal membrane had a more prominent podoplanin-positive capillary profile, but not a prominent CD34-positive capillary profile. In addition, fibroblast-like cells double-positive for podoplanin and smooth muscle actin were markedly increased in the degenerated layer, as previously reported. ♦ Conclusions: Our study demonstrated that lymphatic vessels are increased in the visceral peritoneum of patients with EPS.

Early cystoadenocarcinoma of vermiform appendix simulating submucosal tumor of the cecum

Colonoscopy was performed on a 54-year-old man with occult melena in our hospital. A submucosal tumor with a maximum diameter of 5cm was detected in the cecum. The tissue of the submucosal tumor was not obtained by endoscopic biopsy, and tumor diagnosis could not be confirmed by this method. A large, hypodense, cystic structure extending below the inferior wall of the cecum was revealed by computed tomography (CT). Because the tumor was too large to be a benign tumor, we were able to conclude it was malignant. After receiving informed consent from the patient, laparoscopic right colectomy was performed for both diagnosis and treatment in June 2004. As the swollen vermiform appendix pressed the cecum extraluminally, endoscopic examination indicated the possibility of submucosal tumor. Postoperative pathological diagnosis was cystoadenocarcinoma, the tumor was extended within the mucosal layer, and no lymph node metastasis was detected. Cancer cells were not present in the viscous liquid of the vermiform appendix intracavitary, either. The patient left the hospital in 10 days postoperatively. He regularly underwent examinations including CT, and no recurrence was detected for more than 24 months following the laparoscopic operation.