Intraoperative Colonoscopy in Laparoscopic Rectal Cancer Surgery Reduces Anastomotic Leakage.

Objectives: Anastomotic leakage (AL) is the most severe complication of colorectal surgery and is a frequent cause of postoperative mortality. This study aimed to identify the risk factors for AL, including the type of air leak test (ALT) performed, in patients undergoing laparoscopic colorectal cancer surgery. Methods: This study involved a retrospective review of 201 patients who underwent elective laparoscopic procedures using circular stapled anastomosis for colorectal cancer between January 2015 and December 2020 at Kyorin University Hospital, Tokyo, Japan. In all cases, the distance from the anal verge to the anastomotic site was within 15 cm. Results: Overall, AL was observed in 16 patients (8.0%). Univariate analysis revealed that the risk factors for AL included diabetes (P = 0.068), tumor location (P = 0.049), level of anastomosis (P = 0.002), number of linear stapler firings (P = 0.007), and intraoperative colonoscopy (IOCS; P = 0.069). Multivariate analysis revealed that the level of anastomosis (P = 0.029) and IOCS (P = 0.039) were significant and independent risk factors for AL. One of the 107 patients undergoing ALT without IOCS and 3 of the 94 patients undergoing ALT with IOCS were proven to be positive for air leak. However, these four patients underwent additional suturing intraoperatively and developed no AL following surgery. Conclusions: This study identified the level of anastomosis and ALT with IOCS as predictors for AL. The results of our study indicate that ALT with IOCS may be more effective than ALT without IOCS in the diagnosis and prevention of AL.

Prognostic factors of patients with left-sided obstructive colorectal cancer: post hoc analysis of a retrospective multicenter study by the Japan Colonic Stent Safe Procedure Research Group.

BACKGROUND: There are many reports on the choice of treatment for and prognosis of left-sided obstructive colorectal cancer; however, few studies have focused on the prognostic factors of left-sided obstructive colorectal cancer. Therefore, we analyzed the prognostic factors using a post hoc analysis of a retrospective multicenter study in Japan. METHODS: A total of 301 patients were enrolled in this study to investigate the prognostic factors for relapse-free survival. The relationships between sex, age, decompression for bridge to surgery, depth of invasion, lymph node metastasis, postoperative complications, adjuvant chemotherapy, carcinoembryonic antigen, carbohydrate antigen 19-9, neutrophil-to-lymphocyte ratio, and relapse-free survival were examined. RESULTS: No change in the decompression method, T3 cancer, negative postoperative complications (grades 0-1 of Clavien-Dindo classification), and adjuvant chemotherapy during Stage III indicated a significantly better prognosis in a Cox univariate analysis. Lymph node metastasis was not selected as a prognostic factor. Excluding patients with <12 harvested lymph nodes (possible stage migration), lymph node metastasis was determined as a prognostic factor. In a Cox multivariate analysis, change in the decompression method, depth of invasion, lymph node metastasis (excluding N0 cases with <12 harvested lymph nodes), and adjuvant chemotherapy were prognostic factors. CONCLUSIONS: Similar to those in nonobstructive colorectal cancer, depth of invasion and lymph node metastasis were prognostic factors in left-sided obstructive colorectal cancer, and patients with <12 dissected lymph nodes experienced stage migration. Stage migration may result in disadvantages, such as not being able to receive adjuvant chemotherapy.

Effectiveness of negative pressure wound therapy for the wound of ileostomy closure: a multicenter, phase II randomized controlled trial.

BACKGROUND: The American Society of Surgery and American Society for Surgical Infections issued guidelines for surgical site infections (SSIs) in December 2016. These guidelines recommend a purse-string suture (PSS) for stoma closure as it facilitates granulation and enables open wound drainage. This study investigated the effect of using negative pressure wound therapy (NPWT) along with standard PSS and aimed to determine the optimal period of NPWT use. METHODS: The patients were divided into three groups as follows: Group A, postoperative wound management alone with gauze exchange as the representative of conventional PSS; Group B, the performed management was similar to that of Group A plus NPWT for 1 week; and Group C, the performed management was similar to that of Group A plus NPWT for 2 weeks. Regarding objective measures, the wound reduction rate was the primary outcome, and the incidence of SSIs, length of hospital stay, and wound healing duration were the secondary outcomes. RESULTS: In total, 30 patients (male: 18, female: 12) were enrolled. The average age was 63 (range: 43-84) years. The wound reduction rate was significantly higher in Group B than in Group A on postoperative days (PODs) 7 (66.1 vs. 48.4%, p = 0.049) and 10 (78.6 vs. 58.2%, p = 0.011), whereas no significant difference was observed on POD 14. Compared with Group A, Group C (POD 7: 65.9%, POD 10: 69.2%) showed an increase in the wound reduction rate on POD 7, although the difference was not significant (p = 0.075). SSIs were observed in Groups B (n = 2) and C (n = 2) (20%) but not in Group A (0%). CONCLUSIONS: The most effective duration of NPWT use for ileostomy closure with PSS in terms of the maximum wound reduction rate was from PODs 3 to 10. However, NPWT did not shorten the wound healing duration. NPWT may reduce the wound size but should be used with precautions for SSIs. The small sample size (30 cases), the use of only one type of NPWT system, and the fact that wound assessment was subjective and not blinded were the limitations of this study. Further studies are needed to confirm our findings. TRIAL REGISTRATION: UMIN Clinical Trials Registry; UMIN000032174 (10/04/2018).

Site-specific risk factors for local recurrence after rectal cancer surgery.

BACKGROUND: Quite few studies examined risk factors for local recurrence after rectal cancer surgery with respect to local recurrence sites. METHODS: Local recurrence sites were categorized into axial, anterior, posterior, and lateral (pelvic sidewall), and axial, anterior, and posterior type were combined as the "other" type of local recurrence. Among 76 patients enrolled into our prospective randomized controlled trial to determine the indication for pelvic autonomic nerve preservation (PANP) in patients with advanced lower rectal cancer (UMIN000021353), multivariate analyses were conducted to elucidate risk factors for either lateral or the "other" type of local recurrence. RESULTS: Univariate analyses showed that tumor distance from the anal verge was significantly (p = 0.017), and type of operation (sphincter preserving operation (SPO) vs. abdominoperineal resection (APR)) was marginally (p = 0.065) associated with pelvic sidewall recurrence. Multivariate analysis using these two parameters showed that tumor distance from the anal verge was significantly and independently correlated with pelvic sidewall recurrence (p = 0.017). As for the "other" type of local recurrence, univariate analyses showed that depth of tumor invasion (p = 0.011), radial margin status (p < 0.001), and adjuvant chemotherapy (p = 0.037) were significantly associated, and multivariate analysis using these three parameters revealed that depth of tumor invasion (p = 0.004) and radial margin status (p < 0.001) were significantly and independently correlated with the "other" type of local recurrence. CONCLUSION: Risk factors for local recurrence after rectal cancer surgery were totally different with respect to the intra-pelvic recurrent sites. Site-specific probability of local recurrence can be inferred using these risk factors. TRIAL REGISTRATION NUMBER: UMIN000021353.

Changing Patterns of Distant Metastasis in Patients With Lower Rectal Cancer Undergoing Intraoperative Radiotherapy.

BACKGROUND/AIM: Local radiotherapy for primary tumors may increase the incidence of distant metastasis. However, the patterns of target organs have not been clarified yet. PATIENTS AND METHODS: In our randomized controlled trial examining the oncological efficacy of intraoperative radiotherapy (IORT) for advanced lower rectal cancer, the details of the metastatic organs were evaluated. RESULTS: In the IORT group (38 patients), 2 patients had metastasis in the liver and lung simultaneously, 9 in the liver, and 4 in the lung. In the control group (38 patients), 3 had metastasis in the lung, and 2 in the liver. The IORT group tended to have liver metastases more frequently (p=0.058). Among patients with liver metastases, distant metastasis-free intervals were significantly shorter in the IORT group, however, no significant difference was observed among patients with lung metastases. CONCLUSION: After curative rectal cancer surgery with IORT, liver metastasis may be increased and accelerated.

Intraoperative radiotherapy for resectable advanced lower rectal cancer-final results of a randomized controlled trial (UMIN000021353).

AIM: Pelvic autonomic nerve preservation (PANP) is useful to preserve voiding and sexual function after rectal cancer surgery. The aim of this study was to investigate the benefit of intraoperative radiotherapy (IORT) to have complete PANP without affecting oncological outcomes. METHODS: Patients undergoing potentially curative resection of the rectum were included. They were randomized to intraoperative radiotherapy of the completely preserved bilateral pelvic nerve plexuses (IORT group) or the control group without IORT, but with limited nerve preservation. The primary endpoint was pelvic sidewall recurrence. Moreover, patients' clinicopathologic parameters, postoperative complications, voiding function, and other oncologic outcomes were compared. RESULTS: From 79 patients, three were excluded from analysis, resulting in 38 patients in each group. Patients' demographic and pathological parameters were well balanced between the two groups. The trial was terminated prematurely in July 2017, because distant metastasis-free survivals were found to be significantly worse in the IORT group compared to the control group (odds ratio 2.554; 95% CI, 1.041 ~ 6.269; p = 0.041). Neither overall survival nor pelvic sidewall recurrence did differ between the two groups (overall survival: odds ratio 1.264; 95% CI, 0.523~3.051; p = 0.603/pelvic sidewall recurrence; odds ratio 1.350; 95% CI, 0.302~6.034; p = 0.694). Postoperative complications did not differ between the groups; however, the urinary function was significantly better in the IORT group in the short and long term. CONCLUSION: With the aid of IORT, complete PANP can be done without increase of pelvic sidewall recurrence; however, IORT may increase the incidence of distant metastases. Therefore, IORT cannot be recommended as a standard therapy to compensate less radical resection for advanced lower rectal cancer.

The impact of tumor location on the biological and oncological differences of colon cancer: Multi-institutional propensity score-matched study.

BACKGROUND: Several studies have reported some differences between right-sided and left-sided colon cancer. The aim was to analyze the differences in clinical and pathological features, recurrence, and prognostic impact of tumor location in patients with tumors truly located in the right and left side of the colon. PATIENTS: The study included 6790 stage I-III colon cancer patients who underwent curative resection. Patient characteristics were balanced using propensity score matching. RESULTS: Recurrence rates of stage I and II patients with left-sided colon cancer were higher than those in the right-sided group, indicating that recurrence free survival of left-sided colon cancer patients was significantly shorter than that of the right-sided patients. In stage III patients that experienced recurrence, cancer specific survival after recurrence of the right-sided colon cancer patients was significantly shorter than that of the left-sided patients (P = 0.003). CONCLUSIONS: In stage I-II patients, left-sided colon cancer was a significant risk factor for recurrence free survival, however, in stage III patients, right-sided colon cancer was a significant risk factor for after recurrence cancer specific survival.

Optimal Surveillance Protocols After Curative Resection in Patients With Stage IV Colorectal Cancer: A Multicenter Retrospective Study.

BACKGROUND: After patients with stage IV colorectal cancer undergo curative surgical resection, there is a large risk for recurrence. To establish optimal surveillance guidelines, an understanding of the temporal risk factors for recurrence is necessary. OBJECTIVE: The primary aim of our study was to determine predictors for early (within 1 year), middle (1-2 years), and late (2 years or later) recurrence following curative resection in patients with stage IV colorectal cancer. DESIGN: This was a retrospective cohort study. SETTINGS: The study was conducted at multiple institutions. PATIENTS: The retrospective cohort study comprised 1070 patients with stage IV colorectal cancer after an R0 resection for the primary and metastatic lesions in 19 institutions from January 1997 to December 2007. MAIN OUTCOME MEASURES: Risk factors for early, middle, and late recurrence were determined by logistic regression and Cox proportional hazards models. RESULTS: The overall recurrence rate was 73% (784/1070). Cancer-specific survival was 29.5 months, and recurrence-free survival was 8.9 months. Early recurrence occurred in 488 (62%), middle recurrence in 184 (24%), and late recurrence in 112 (14%). In multivariable analysis, early recurrence risk factors included rectum site, depth of tumor invasion (T4), increasing N-staging, venous invasion, and liver metastasis. Late recurrence risk factors were tumor size ≤50 mm, and peritoneal dissemination. LIMITATIONS: Because of the retrospective nature of this study, postoperative therapy was not standardized. CONCLUSIONS: Risk factors differ for early, middle, and late recurrences of stage IV colorectal cancer following curative resection. Early (within 1 year) recurrence factors were rectum site, T4, N-staging, venous invasion, and liver metastasis, whereas late (2 years or later) recurrence risk factors were small tumor size and peritoneal dissemination. Our study provides important data to guide a surveillance protocol following stage IV colorectal cancer curative resection. See Video Abstract at http://links.lww.com/DCR/A460.

Rapid detection of semenogelin by one-step immunochromatographic assay for semen identification.

To identify semen in forensic samples, we developed an analytical system for one-step immunoassay that has been constructed using the concept of immunochromatography and can identify semenogelin (Sg), which originates in the seminal vesicles. The system employed monoclonal antibody (mAb) and polyclonal antibody (pAb) against recombinant Sg-II (63 kDa), which has been synthesized in insect cells using baculovirus. The two antibodies bound with the seminal plasma motility inhibitor (SPMI; 14 kDa) as a final fragment peptide of Sg. The test stick is based on the sandwich technique using the above antibodies. When serial dilutions of seminal plasma were analyzed using this test stick, the intensity of a clear immunoreactive signal peaked at 2000-fold dilution. Thereafter, the signals decreased slowly but still persisted up to 400,000-fold dilution. The Sg antigen was undetectable in saliva, urine, breast milk, serum or vaginal secretions. Also, the test stick shown did not react with animal semen samples, such as those from horses, dogs, swine and bulls. When semen samples, diluted 100,000-fold from 100 men were tested, the Sg antigenic activity was detectable in all samples. In addition, the specificity and sensitivity of the test stick for identification of semen were demonstrated by comparative forensic studies. We conclude that this immunoassay method is a useful confirmatory test for the identification of semen. The immunochromatographic system for forensic testing or research use will become available commercially soon.