Laparoscopic surgery is widely used for rectal cancer; however, this technique is challenging due to tapering of the mesorectum in the pelvis, and the forward angle of the distal rectum, which renders this part of the rectum less accessible from the abdominal cavity. Hence, concerns regarding its safety and curability have been raised, particularly for inadequate distal and circumferential resection margins. Recently, transanal total mesorectal excision (TaTME), which involves endoscopic total mesorectal excision (TME) retrogradely from the anal side, has attracted attention worldwide as a solution to these problems. TaTME is superior to the conventional laparoscopic approach for rectal cancer in terms of both oncological and functional preservations. However, a shallow learning curve caused by the unfamiliar anatomical view from the anal side can pose challenges. Therefore, an efficient educational system needs to be established. Randomized controlled trials comparing conventional laparoscopic TME with TaTME are ongoing to demonstrate the usefulness of TaTME. This article reviews changes in the surgical treatment of rectal cancer, with a focus on TaTME, and describes the indications, surgical techniques, and training curricula for TaTME.

For transanal total mesorectal excision (TaTME), the indication for single-stapling technique (SST) has been expanded to include lower anastomosis, even in intersphincteric resection (ISR). We focused on the anastomotic techniques following ISR with TaTME and examined the feasibility and safety of the SST below the anorectal junction (ARJ). Data on postoperative anastomosis-related complications and anorectal function was evaluated in comparison to conventional manual hand-sewn coloanal anastomosis in ISR with TaTME. We examined patients with 3-6 cm tumors from the anal verge who underwent ISR with TaTME between January 2018 and March 2020, and whose anastomotic line was located below the ARJ. Postoperative short-term outcomes and anorectal functions were compared. We also analyzed the effects of various factors on major low anterior resection syndrome (LARS) using multivariate logistic regression analysis. In total, 87 patients-48 in the hand-sewn anastomosis group and 39 in the SST group-were included in this study. SST below the ARJ in ISR with TaTME did not exacerbate surgical outcomes, including anastomosis-related complications. The SST group had a significantly lower LARS score as compared to the hand-sewn anastomosis group, and the proportion of major LARS was significantly lower. Only hand-sewn anastomosis was identified as a statistically significant independent risk factor for major LARS. In TaTME, SST below the ARJ was safe and feasible and had a lower negative impact on postoperative anastomosis-related complications and anorectal function as compared to hand-sewn anastomosis. Thus, SST is a promising anastomotic option for patients with low-lying rectal tumors.

Early-onset colorectal cancer (CRC), which refers to CRC diagnosed in individuals below the age of 50 years, is a growing health concern that presents unique challenges in diagnosis, treatment, and long-term outcomes. Although approximately 70% of early-onset CRC cases are sporadic, with no apparent family history, approximately 25% have a familial component, and up to 20% may be associated with germline mutations, indicating a higher prevalence compared with the general population. Despite the progress in identifying the environmental, molecular, and genetic risk factors of early-onset CRC, the underlying causes for the global increase in its incidence remain unclear. This comprehensive review aims to provide a thorough analysis of early-onset CRC by examining the trends associated with its incidence, clinical and pathological characteristics, risk factors, molecular and genetic profiles, prognosis and screening strategies. By deepening our understanding of early-onset CRC, significant advances related to improving the outcomes and alleviating the burden of this disease on individuals, families, and healthcare systems can be achieved.

Objectives: Conventional anal dilatation for anal fissures has long been abandoned because of the high incidence of anal incontinence. However, less invasive and more precise dilation techniques have been developed that have shown high healing and low incontinence rates. This study aimed to evaluate the efficacy and safety of controlled anal dilatation (CAD) using a standardized maximum anal diameter.

Methods: This study included 523 patients who underwent CAD for chronic anal fissures between January 2010 and December 2014. CAD was performed under sacral epidural anesthesia. The index fingers of both hands were placed in the anus and dilated evenly in various directions. CAD was completed when the anus was dilated to the sixth scale (35 mm in diameter) using a caliber ruler.

Results: The mean anal scale size expanded from 3.1 to 5.8 (p<0.001). Non-healing was observed in nine patients (1.7%) at 1 month postoperatively, six of whom underwent additional CAD. The mean maximal anal resting pressure (mmHg) decreased from 90.2 to 79.7 at three months postoperatively (p<0.001). Postoperative complications were observed in 11 (2.1%) patients, of whom three patients with thrombosed hemorrhoids underwent resection. None of the patients complained of anal incontinence during the mean follow-up period of 16.6 months. The cumulative recurrence-free rates at three and five years were 87.9% and 69.2%, respectively.

Conclusions: CAD is technically simple and safe and can achieve reasonable long-term outcomes. Thus, CAD appears to be the preferred procedure for patients with chronic anal fissures who do not respond to conservative treatments.

Objectives: Stomal prolapse (SP) is one of the most common complications of loop colostomy and can impair a patient's quality of life. Herein, we evaluated the risk factors for SP to prevent its occurrence after a transverse loop colostomy.

Methods: This retrospective study included 84 patients who underwent loop transverse colostomy between January 2016 and December 2020. We evaluated the incidence of SP and examined the relationship between perioperative factors and SP using univariate and multivariate logistic regressions.

Results: SP occurred in 11 (13.0%) patients. Median time to SP was 99 postoperative days. In the univariate analysis, a right side abdominal wall stoma site, perioperative chemotherapy, and anti-VEGF antibody therapy were associated with a significantly higher incidence of SP. Multivariate analysis identified that construction of a temporary loop colostomy in the right transverse colon during rectal cancer surgery (odds ratio, 5.07; 95% confidence interval, 1.12-22.86) is an independent risk factor.

Conclusions: In this study, multivariate analysis showed that the right side of the transverse colon was a risk factor for SP. Therefore, when constructing a transverse colon loop stoma, the stoma should be constructed in the left transverse colon to prevent SP.

Objectives: Clostridioides difficile (CD) is an anaerobic spore-forming Gram-positive rod that is a major cause of antibiotic-associated diarrhea. Hyperbaric oxygen therapy (HBO) is a well-established treatment for Clostridium perfringens, but there are no reports that have examined the efficacy of HBO against CD, which is also an anaerobic bacterium.

Methods: In this study, we retrospectively examined whether HBO therapy affects the prognosis following CD infections (CDI). This study included 92 inpatients diagnosed with CDI at our hospital between January 2013 and December 2022. Of these, 16 patients received HBO therapy. The indications for HBO therapy were stroke in five patients, ileus in four patients, cancer in two patients, acute peripheral circulatory disturbance in two patients, and others in three patients. The mean observation period was 5.4 years.

Results: In the univariate analysis, there was no significant difference in severity, mortality, hospitalization, or overall survival between patients who did and did not receive HBO therapy. However, the HBO group had a significantly lower recurrence rate (0% vs. 22.4%, p=0.0363) and a shorter symptomatic period (6.2 vs. 13.6 days, p=0.0217).

Conclusions: HBO may have beneficial effect on CDI by shortening the symptomatic period and preventing recurrence.

Objectives: The current retrospective study aimed to evaluate the association between combined preoperative and postoperative C-reactive protein-to-albumin ratio, which is correlated with prognosis in different types of malignancies, and prognosis after curative resection in patients with colorectal cancer.

Methods: This study enrolled 263 patients who underwent curative resection for stage II/III colorectal cancer. C-reactive protein-to-albumin ratio was calculated within 30 days before and 7 days after surgery. Receiver operating characteristic curve analyses were performed to determine the optimal cutoff values of preoperative and postoperative C-reactive protein-to-albumin ratio. The correlations between combined preoperative and postoperative C-reactive protein-to-albumin ratio and prognosis were analyzed.

Results: The cutoff values of preoperative and postoperative C-reactive protein-to-albumin ratio were 0.223 and 0.813, respectively; higher ratios were significantly associated with poor overall survival, based on the Kaplan-Meier curves (p < 0.001, p = 0.003, respectively). Further, preoperative and postoperative C-reactive protein-to-albumin ratios were correlated with poor progression-free survival (p < 0.001, p = 0.064, respectively). In the multivariate analysis, combined preoperative and postoperative C-reactive protein-to-albumin ratio was an independent predictor of overall survival and progression-free survival (p = 0.012, p = 0.044, respectively). Compared with low preoperative and postoperative C-reactive protein-to-albumin ratio, high ratios of that were significantly associated with poor overall survival (hazard ratio = 3.897, p = 0.006) and progression-free survival (hazard ratio = 2.130, p = 0.029).

Conclusions: Combined preoperative and postoperative C-reactive protein-to-albumin ratio, useful for prognostic prediction, can be a promising prognostic marker after curative resection in patients with colorectal cancer.

Cowden syndrome (CS) /PTEN hamartoma tumor syndrome (PHTS) is a rare autosomal dominantly inherited condition caused by germline pathogenesis. It is associated with multiple hamartomatous lesions occurring in various organs and tissues, including the gastrointestinal tract, skin, mucous membranes, breast, thyroid, endometrium, and brain. Macrocephaly or multiple characteristic mucocutaneous lesions commonly develop in individuals in their 20s. This syndrome is occasionally diagnosed in childhood due to the occurrence of multiple gastrointestinal polyps, autism spectrum disorders, and intellectual disability. CS/PHTS can be diagnosed taking the opportunity of multigene panel testing in patients with cancer. Appropriate surveillance for early diagnosis of associated cancers is required because patients have a high risk of cancers including breast, thyroid, colorectal, endometrial, and renal cancers.

Under these circumstances, there is growing concern regarding the management of CS/PHTS in Japan, but there are no available practice guidelines. To address this situation, the guideline committee, which included specialists from multiple academic societies, was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour, and Welfare, Japan. The present clinical guidelines explain the principles in the diagnosis and management of CS/PHTS, together with four clinical questions and the corresponding recommendations, incorporating the concept of the Grading of Recommendations Assessment, Development, and Evaluation system. Herein, we present an English version of the guideline, some of which have been updated, to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with CS/PHTS.

Objectives: The aim of this study was to evaluate the effectiveness of transperineal repair of secondary perineal hernia (SPH) using a mesh with a memory-recoil ring.

Methods: Seven patients with SPH who underwent transperineal repair (TPR) between July 2010 and May 2022 were retrospectively analyzed. TPR was performed using a mesh with a memory-recoil ring.

Results: All SPHs developed after abdominoperineal resections in patients with anorectal malignancies. The median longitudinal and transverse diameters of the hernia orifice were 8 (7-10) cm and 6 (5-7) cm, respectively. In all cases, the mesh was fixed to the ischial tuberosity, residual levator muscle, coccygeus muscle, and coccyx after thorough dissection of the sac. The median operation time was 154 (142-280) min. Perioperative complications occurred in 2 cases (29%). One was enterotomy, which caused postoperative mesh infection requiring extraction of the mesh. The other was vaginal injury, which resulted in vaginal fistula but closed spontaneously. The median postoperative length of stay was 9 (5-14) days. No recurrence was observed during a median follow-up of 35 (9-151) months.

Conclusions: TPR using a mesh with a memory-recoil ring is safe, feasible and promising technique for SPH repairs.

A 72-year-old man with type 2 sub-circumferential tumors in the descending colon and two nodules around the pedicle of the inferior mesenteric artery (main lymph node area) underwent laparoscopic left hemicolectomy with D3 lymphadenectomy. Two lymph nodes around the inferior mesenteric artery pedicle were completely excised. Pathological examination revealed a moderately differentiated tubular adenocarcinoma. Nodules were only found in the main lymph node area, and no lymph node structures were observed in these nodules. These tumor deposits (TDs) may be extramural TDs without lymph node structure or lymph node skip metastasis. The presence of TDs in colorectal cancer is associated with an adverse prognosis, and the requirement of chemotherapy in such cases should be examined. Therefore, it is important to correctly recognize TDs and categorize the disease into a high- or low-risk group within stage III. We report this case because it is necessary to review the definition of TDs, and the assessment of extramural TDs remains controversial.