Objectives: In Japan, there are three grades of peritoneal metastasis from colorectal cancer. The grade depends on the extent and number of lesions (P classification). The P classification is useful for its simplicity but lacks objectivity. On the other hand, the peritoneal cancer index (PCI) objectively indicates the peritoneal metastasis grade. However, the evaluation process is complicated clinically. In this study, we compared these two methods and investigated how to improve the P classification's objectivity by referring to PCI.

Methods: We investigated 150 cases of synchronous peritoneal metastasis from colorectal cancer. We inspected the correlation between the P classification and the PCI and pointed out the problems which prevented objective evaluation when using the P classification. We also estimated new criteria for extent and number in the P classification.

Results: We found the ideal definition for the best alignment between the P classification and the PCI was:

・P1 is metastases confined to one peritoneal region,

・P2 is 19 or fewer peritoneal metastases in two or more regions, and

・P3 is 20 or more metastases in two or more regions.

This revision improved the P classification's objectivity and correlated with the PCI.

Conclusions: Grading using the P classification was both imprecise and subjective. We propose a new standard value of extent and number in the P classification based on the PCI. This improvement would provide an objective, simple method of grading for peritoneal metastasis from colorectal cancer.

Objectives: To investigate the prevalence and molecular characteristics of defective DNA mismatch repair (dMMR) in small-bowel carcinoma (SBC) in a Japanese-hospital population.

Methods: Immunohistochemistry was performed to evaluate the expression of MMR proteins (MLH1, MSH2, MSH6, and PMS2) in formalin-fixed paraffin-embedded sections prepared from surgically resected primary SBCs from 30 patients during March 2002 to March 2017. Genetic testing for Lynch syndrome was performed in patients who demonstrated MMR protein loss.

Results: Two of 30 patients (6.7%) demonstrated concomitant loss of MSH2/MSH6 protein expression. Further genetic testing identified a pathogenic MSH2 variant in one of these patients.

Conclusions: The prevalence of dMMR SBCs in a Japanese hospital-based population seems lower than that reported in previous studies. To determine whether dMMR SBCs might be strongly linked to Lynch syndrome, there is a need for further investigation with a larger sample size.

Objective: Additional surgery is considered for patients at high risk for lymph node metastasis (LNM) after local resection for early rectal cancer. Several factors are considered as indications for additional surgery, although there are currently no definitive criteria. This study aimed to clarify the need for additional surgery based on the number of risk factors for LNM and to evaluate the significance of submucosal invasion on recurrence.

Methods: Patients with early rectal cancer harboring risk factors for LNM who underwent local resection between March 2005 and December 2016 were retrospectively analyzed. Associations among the number of risk factors, prognosis, and additional treatment after local resection were investigated.

Results: A total of 29 eligible patients were classified into the surgery (n = 10), chemoradiotherapy (n = 7), and no-additional-treatment (NAT, n = 12) groups. Among the 29 patients, 15 patients (52%) with only one risk factor did not relapse. The NAT group harbored fewer risk factors for LNM, and 8 of the 12 patients (67%) had only deep submucosal invasion. Local recurrence occurred in one patient in the chemoradiotherapy group. The estimated 5-year overall survival rates were 88.9%, 75.0%, and 81.5% in the surgery, chemoradiotherapy, and NAT groups, respectively. There were no disease-specific deaths in the overall cohort.

Conclusions: In the present study, no recurrence occurred in patients who did not receive additional surgery with deep submucosal invasion as the only risk factor. A multicenter investigation is necessary to confirm the safety of nonsurgical options.

Objectives: Restorative proctocolectomy and ileal pouch anal anastomosis (IPAA), with diverting ileostomy, are established ulcerative colitis (UC) treatments. The routine use of diverting ileostomy is controversial because of the risk of stoma closure and stoma related complications. In our institution, proctocolectomy and IPAA, with mucosectomy and handsewn anastomosis without diversion (one-stage IPAA), were performed for select patients with UC. The present study aimed to evaluate the clinical and functional outcomes of patients undergoing one-stage IPAA.

Methods: Between April 1999 and July 2017, 300 patients underwent one-stage IPAA in our institution. The clinical notes and prognosis were reviewed retrospectively.

Results: Postoperative complications (Clavien-Dindo classification grade ≥III) occurred in 18 patients (6.0%). The most common complication was anastomotic leakage (n = 9, 3%). There were 15 patients (5.0%) who required a defunctioning ileostomy. However, 13 patients successfully underwent ileostomy closure and achieved acceptable pouch function. Finally, two patients (0.6%) required pouch excision in this series. The cumulative pouch functional rate was 99.6% / 5 years and 99.2% / 10 years.

Conclusions: One-stage IPAA is a good strategy for carefully selected patients with UC.

Objectives: Hemorrhoid is a common disease in surgical practice, but only a few numbers of patients need surgical treatment. The most common concern of patients is postoperative pain. This study aimed to evaluate the efficacy and safety of an intersphincteric injection of botulinum toxin for post-hemorrhoidectomy pain relief.

Methods: Overall, 90 patients were enrolled, and 44 were randomized into a botulinum toxin injection group. Preoperative gradings were grade III 37 patients and grade II 2 patients. Patients received an intersphincteric injection of 0.5 ml of a solution containing 30 units of botulinum toxin (BTX). The postoperative data were collected pain score in a visual analog score (VAS), an analgesic used, hospital stay, and complication.

Results: The VAS was lower in the BTX group at 12 hours and 24 hours postoperative phase. VAS at 12 hours 4.435 ± 2.149 vs 6.232 ± 2.307 (p < 0.001), VAS at 24 hours 2.205 ± 2.079 vs 3.744 ± 2.361 (p = 0.003). The BTX group has a shorter time in defection without pain than the control group (3 vs. two days, p = 0.007). There was no difference in immediate and delay complications between the two groups.

Conclusions: Postoperative hemorrhoidectomy needs multimodalities for pain reduction. Botulinum toxin has some benefit in postoperative pain reduction.

Objectives: This study aimed to elucidate the effect of the extract of daikenchuto (DKT), a Japanese Kampo medicine, on the contractile activity of the internal anal sphincter in conscious dogs.

Methods: Force transducers were attached to the serosal surface of the rectum and the internal anal sphincter of male beagle dogs. In addition, the contractile activity of the rectum and the internal anal sphincter was continuously measured until 6 h after DKT administration via telemetry in the conscious state. The DKT dose was 1.5 g/body, and the administration route was intrarectal in the expectation of a direct effect on the rectoanal region. DKT was re-administered to the same animal after drug withdrawal, and the plasma concentrations of hydroxy-α-sanshool (HAS) and hydroxy-β-sanshool (HBS) before and after administration were measured.

Results: After DKT administration, the contractile activity of the internal anal sphincter immediately increased, peaked at 10 min, continued for ≥1 h, and had almost disappeared after 4 h. Rectal contraction differed from that of the internal anal sphincter, with no significant contraction observed. HAS and HBS were found in the plasma of animals administered with DKT and persisted up to 2 h after the administration.

Conclusions: This is the first report on in vivo telemetry demonstrating that DKT exhibited contractile effects on the dog's internal anal sphincter. The increased anal pressure and improvement of fecal incontinence symptoms observed in previous clinical studies may have been based on this sphincter contraction.

Vascular Ehlers-Danlos syndrome (vEDS) is a rare autosomal dominant connective tissue disease. Patients with vEDS are at a high risk of developing severe complications (such as arterial aneurysm, arterial rupture, intestinal rupture) at an early age. We report a case of colonic perforation in a vEDS patient with no family history of that disease. A 28-year-old man with abdominal pain arrived at our hospital in an ambulance. The preoperative diagnosis was panperitonitis due to gastrointestinal perforation. Although his parents had not suffered from vEDS, he had been diagnosed with the disease at 25 years of age because of his history of arterial dissection. We performed an emergency operation using Hartmann's procedure to construct a descending colostomy. There remains a lack of consensus on surgical management in vEDS patients with gastrointestinal perforation because of the limited number of reported cases.