Evaluation of the advantage of surgeons certified by the endoscopic surgical skill qualification system participating in laparoscopic low anterior rectal resection.

Background: A technical qualification system was developed in 2004 by the Japan Society for Endoscopic Surgery. An analysis of the EnSSURE study on 3188 stage II-III rectal cancer patients, which was performed by including the participation of qualified surgeons as assistants and advisers without restricting their participation as operators, revealed that the participation of technically qualified surgeons in surgery improved the technical and oncological safety of laparoscopic rectal resection. Aim: This secondary retrospective analysis of the EnSSURE study examined the advantage of qualified surgeons participating in laparoscopic low anterior resection (LAR). Methods: The outcomes of low anterior resection were compared between groups with and without the participation of surgeons qualified by the Endoscopic Surgical Skill Qualification System (Q and non-Q groups, respectively). We used propensity score matching to generate paired cohorts at a one-to-one ratio. The postoperative complication rate, short-term results (hemorrhage volume, operative time, number of dissected lymph nodes, open conversion rate, intraoperative complication rate, and R0 resection rate), and long-term results (disease-free survival rate, local recurrence rate, and overall survival rate) were evaluated. Results: The frequencies of postoperative complications, anastomotic bleeding, and intraperitoneal abscess were significantly lower, the operative time was significantly shorter, the postoperative hospital stay was significantly shorter, and the number of dissected lymph nodes was higher in the Q group. No significant differences were observed in disease-free survival, local recurrence, or overall survival rate rates between the groups. Conclusion: The participation of qualified surgeons in LAR is technically advantageous.

Differentiation grade as a risk factor for lymph node metastasis in T1 colorectal cancer.

Objectives: Japanese guidelines include high-grade (poorly differentiated) tumors as a risk factor for lymph node metastasis (LNM) in T1 colorectal cancer (CRC). However, whether the grading is based on the least or most predominant component when the lesion consists of two or more levels of differentiation varies among institutions. This study aimed to investigate which method is optimal for assessing the risk of LNM in T1 CRC. Methods: We retrospectively evaluated 971 consecutive patients with T1 CRC who underwent initial or additional surgical resection from 2001 to 2021 at our institution. Tumor grading was divided into low-grade (well- to moderately differentiated) and high-grade based on the least or predominant differentiation analyses. We investigated the correlations between LNM and these two grading analyses. Results: LNM was present in 9.8% of patients. High-grade tumors, as determined by least differentiation analysis, accounted for 17.0%, compared to 0.8% identified by predominant differentiation analysis. A significant association with LNM was noted for the least differentiation method (p < 0.05), while no such association was found for predominant differentiation (p = 0.18). In multivariate logistic regression, grading based on least differentiation was an independent predictor of LNM (p = 0.04, odds ratio 1.68, 95% confidence interval 1.00-2.83). Sensitivity and specificity for detecting LNM were 27.4% and 84.1% for least differentiation, and 2.1% and 99.3% for predominant differentiation, respectively. Conclusions: Tumor grading via least differentiation analysis proved to be a more reliable measure for assessing LNM risk in T1 CRC compared to grading by predominant differentiation.

Optimal Timing of Laparoscopic Cholecystectomy After Conservative Therapy for Acute Cholecystitis.

Background/Aim: According to the Tokyo Guidelines 2018, the operation for acute cholecystitis is recommended to be performed as early as possible. However, there are cases in which early surgeries cannot be performed due to complications of patients or facility conditions, resulting in elective surgery. Hence, we retrospectively analyzed elective surgery cases in this study. Patients and Methods: There were 345 patients who were underwent laparoscopic cholecystectomy (LC) at our hospital from January 2019 to December 2020 in this retrospective study. A total of 83 patients underwent LC more than 3 days after conservative treatment. The elective LC patients were divided into the Early group (4-90 days after onset, n=36) and the Delayed group [91 days or more (13 weeks or more) after onset, n=31], excluding 16 patients who underwent percutaneous transhepatic gallbladder drainage. Results: As for operative time, there was a significant difference between the Delayed and Early groups (91.2 vs. 117 minutes, p=0.0108). And also, there was a significant difference in the postoperative hospital stay, which was significantly shorter in the Delayed group than in the Early group (3.4 vs. 5.9 days, p=0.0436). Although there were no significant differences in either conversion rates or complication rates, both of these were decreasing in the Delayed group. In particular, there were no complications in the Delayed group. Conclusion: When the conservative treatment for acute cholecystitis precedes and precludes urgent/early LC within 3 days, delaying LC for at least 91 days (13 weeks or more) after onset could reduce operative time and postoperative hospital stay. Moreover, there would be no complications after LC, and the rates of conversion during LC may be kept low.

Whole slide image-based prediction of lymph node metastasis in T1 colorectal cancer using unsupervised artificial intelligence.

OBJECTIVES: Lymph node metastasis (LNM) prediction for T1 colorectal cancer (CRC) is critical for determining the need for surgery after endoscopic resection because LNM occurs in 10%. We aimed to develop a novel artificial intelligence (AI) system using whole slide images (WSIs) to predict LNM. METHODS: We conducted a retrospective single center study. To train and test the AI model, we included LNM status-confirmed T1 and T2 CRC between April 2001 and October 2021. These lesions were divided into two cohorts: training (T1 and T2) and testing (T1). WSIs were cropped into small patches and clustered by unsupervised K-means. The percentage of patches belonging to each cluster was calculated from each WSI. Each cluster's percentage, sex, and tumor location were extracted and learned using the random forest algorithm. We calculated the areas under the receiver operating characteristic curves (AUCs) to identify the LNM and the rate of over-surgery of the AI model and the guidelines. RESULTS: The training cohort contained 217 T1 and 268 T2 CRCs, while 100 T1 cases (LNM-positivity 15%) were the test cohort. The AUC of the AI system for the test cohort was 0.74 (95% confidence interval [CI] 0.58-0.86), and 0.52 (95% CI 0.50-0.55) using the guidelines criteria (P = 0.0028). This AI model could reduce the 21% of over-surgery compared to the guidelines. CONCLUSION: We developed a pathologist-independent predictive model for LNM in T1 CRC using WSI for determination of the need for surgery after endoscopic resection. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN000046992, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053590).

The "Watch and Wait" Method After Chemoradiotherapy for Rectal Cancer Requiring Abdominoperineal Resection.

The present study examined the therapeutic effects of preoperative neoadjuvant chemoradiation therapy (NACRT) and predictive factors for complete clinical remission, compared the prognosis and costs of abdominoperineal resection (APR) and the "watch and wait" method (WW), and evaluated the usefulness of WW. In our department, patients with stage II-III lower rectal cancer requiring APR receive NACRT. NACRT was performed as a preoperative treatment (52 Gy + S-1: 80-120 mg/day × 25 days). Eight weeks after the completion of NACRT, rectal examination, endoscopic, computed tomography, and magnetic resonance imaging findings were evaluated to assess its therapeutic effects. APR was indicated for patients in whom endoscopic findings suggested a residual tumor in which a deep ulcer or marginal swelling remained or lymph node metastasis. However, WW was selected for patients who refused APR after informed consent was obtained. In the APR and WW groups, 5- and 20-year treatment costs after CRT were calculated using the Medical Fee Points of Japan in 2020. No significant differences were observed in 3-year disease-free survival rates for either parameter between the two groups. Regarding expenses, treatment costs were lower in the WW group than in the APR group. Organ preservation using active surveillance with CRT for rectal cancer requiring APR is feasible with the achievement of endoluminal complete remission.

Novel "resect and analysis" approach for T2 colorectal cancer with use of artificial intelligence.

BACKGROUND AND AIMS: Because of a lack of reliable preoperative prediction of lymph node involvement in early-stage T2 colorectal cancer (CRC), surgical resection is the current standard treatment. This leads to overtreatment because only 25% of T2 CRC patients turn out to have lymph node metastasis (LNM). We assessed a novel artificial intelligence (AI) system to predict LNM in T2 CRC to ascertain patients who can be safely treated with less-invasive endoscopic resection such as endoscopic full-thickness resection and do not need surgery. METHODS: We included 511 consecutive patients who had surgical resection with T2 CRC from 2001 to 2016; 411 patients (2001-2014) were used as a training set for the random forest-based AI prediction tool, and 100 patients (2014-2016) were used to validate the AI tool performance. The AI algorithm included 8 clinicopathologic variables (patient age and sex, tumor size and location, lymphatic invasion, vascular invasion, histologic differentiation, and serum carcinoembryonic antigen level) and predicted the likelihood of LNM by receiver-operating characteristics using area under the curve (AUC) estimates. RESULTS: Rates of LNM in the training and validation datasets were 26% (106/411) and 28% (28/100), respectively. The AUC of the AI algorithm for the validation cohort was .93. With 96% sensitivity (95% confidence interval, 90%-99%), specificity was 88% (95% confidence interval, 80%-94%). In this case, 64% of patients could avoid surgery, whereas 1.6% of patients with LNM would lose a chance to receive surgery. CONCLUSIONS: Our proposed AI prediction model has a potential to reduce unnecessary surgery for patients with T2 CRC with very little risk. (Clinical trial registration number: UMIN 000038257.).

A technique for constructing diverting loop ileostomy to prevent outlet obstruction after rectal resection and total colectomy: a retrospective single-center study.

PURPOSE: Preventing outlet obstruction associated with a diverting stoma is important. Previously, we constructed a diverting loop ileostomy with the proximal limb of the small intestine on the caudal side, namely the oral inferior (OI) method. However, to address the issue of twisting and stenosis of the small intestine, we recently constructed a diverting loop ileostomy with the proximal limb on the cranial side, namely the oral superior (OS) method. We compared the incidence of outlet obstruction between the two methods. METHODS: The subjects of this retrospective study were 133 patients who underwent colorectal resection or total colectomy, with D2 or more lymph node dissection and diverting loop ileostomy construction, between April, 2001 and December, 2018, at our hospital. The OI method was performed in 54 patients and the OS method was performed in 79 patients. RESULTS: In the OS group, a history of laparotomy, neoadjuvant therapy, clinical stage III, and the use of anti-adhesion materials were more common, whereas blood loss and the incidence of outlet obstruction were significantly lower. Multivariate analysis identified only OS placement as a significant factor for reducing the incidence of outlet obstruction. CONCLUSION: When constructing a diverting loop ileostomy, placing the proximal limb on the cranial side is important.

Impact of non-curative endoscopic submucosal dissection on short- and long-term outcome of subsequent laparoscopic gastrectomy for pT1 gastric cancer.

BACKGROUND: The feasibility and oncological safety of non-curative endoscopic submucosal dissection (ESD) prior to additional gastrectomy for early gastric cancer (EGC) are still unclear. The aim of this study was to evaluate the impact of non-curative ESD on short- and long-term outcomes of subsequent laparoscopic gastrectomy (LG) for pathological T1 (pT1) EGC. METHODS: We retrospectively investigated 422 patients who underwent LG for pT1 EGC between January 2007 and December 2017 at our center. Eighty-five of these patients underwent ESD with curative intent before surgery. Using propensity-score matching for sex, age, body mass index, American society of anesthesiologists score, history of previous abdominal surgery, tumor location, mucosal/submucosal infiltration, histology, lymph node metastasis, extent of lymph node dissection, operative method, lymphatic invasion, and venous invasion, the clinicopathologic and survival data of these patients were compared. RESULTS: The median follow-up period was 60 (range 2-168) months. Using propensity-score matching from a total of 422 patients, 75 patients were selected in the Non-ESD and the ESD cohorts each. There were no significant differences in terms of characteristics and clinicopathological findings between the two groups. Furthermore, there were no significant differences in postoperative morbidity (13.3% vs. 17.3%; P = 0.497) and mortality (1.3% vs. 0%; P = 0.316). Both the 5-year overall survival ratio (88.8% vs. 86.9%; P = 0.757) and 5-year disease-specific survival ratio (97.1% vs. 98.4%; P = 0.333) were similar in the two groups. CONCLUSION: Short- and long-term outcomes of LG in patients with pT1 EGC are not related to preoperative ESD history. Even for non-curative resections, ESD prior to surgery is feasible in terms of oncological and surgical outcomes in pT1 EGC.

Clinicopathological features of small T1 colorectal cancers.

BACKGROUND: Although small colorectal neoplasms (< 10 mm) are often easily resected endoscopically and are considered to have less malignant potential compared with large neoplasms (≥ 10 mm), some are invasive to the submucosa. AIM: To clarify the clinicopathological features of small T1 colorectal cancers. METHODS: Of 32025 colorectal lesions between April 2001 and March 2018, a total of 1152 T1 colorectal cancers resected endoscopically or surgically were included in this study and were divided into two groups by tumor size: a small group (< 10 mm) and a large group (≥ 10 mm). We compared clinicopathological factors including lymph node metastasis (LNM) between the two groups. RESULTS: The incidence of small T1 cancers was 10.1% (116/1152). The percentage of initial endoscopic treatment in small group was significantly higher than in large group (< 10 mm 74.1% vs ≥ 10 mm 60.2%, P < 0.01). In the surgical resection cohort (n = 798), the rate of LNM did not significantly differ between the two groups (small 12.3% vs large 10.9%, P = 0.70). In addition, there were also no significant differences between the two groups in pathological factors such as histological grade, vascular invasion, or lymphatic invasion. CONCLUSION: Because there was no significant difference in the rate of LNM between small and large T1 colorectal cancers, the requirement for additional surgical resection should be determined according to pathological findings, regardless of tumor size.

Obesity is not a risk factor for either mortality or complications after laparoscopic cholecystectomy for cholecystitis.

Obesity is a positive predictor of surgical morbidity. There are few reports of laparoscopic cholecystectomy (LC) outcomes in obese patients. This study aimed to clarify this relationship. This retrospective study included patients who underwent LC at Showa University Northern Yokohama Hospital between January 2017 and April 2020. A total of 563 cases were examined and divided into two groups: obese (n = 142) (BMI ≥ 25 kg/m2) and non-obese (n = 241) (BMI < 25 kg/m2). The non-obese group had more female patients (54%), whereas the obese group had more male patients (59.1%). The obese group was younger (56.6 years). Preoperative laboratory data of liver function were within the normal range. The obese group had a significantly higher white blood cell (WBC) count (6420/µL), although this was within normal range. Operative time was significantly longer in the obese group (p = 0.0001). However, blood loss and conversion rate were not significantly different among the groups, neither were surgical outcomes, including postoperative hospital stay and complications. Male sex and previous abdominal surgery were risk factors for conversion, and only advanced age (≥ 79 years) was an independent predictor of postoperative complications as observed in the multivariate analysis. Although the operation time was prolonged in obese patients, operative factors and outcomes were not. Therefore, LC could be safely performed in obese patients with similar efficacy as in non-obese patients.

Left-sided location is a risk factor for lymph node metastasis of T1 colorectal cancer: a single-center retrospective study.

PURPOSE: Although some studies have reported differences in clinicopathological features between left- and right-sided advanced colorectal cancer (CRC), there are few reports regarding early-stage disease. In this study, we aimed to compare the clinicopathological features of left- and right-sided T1 CRC. METHODS: Subjects were 1142 cases with T1 CRC undergoing surgical or endoscopic resection between 2001 and 2018 at Showa University Northern Yokohama Hospital. Of these, 776 cases were left-sided (descending colon to rectum) and 366 cases were right-sided (cecum to transverse colon). We compared clinical (patients age, sex, tumor size, morphology, initial treatment) and pathological features (invasion depth, histological grade, lymphatic invasion, vascular invasion, tumor budding) including lymph node metastasis (LNM). RESULTS: Left-sided T1 CRC showed significantly higher rates of LNM (left-sided 12.0% vs. right-sided 5.4%, P < 0.05) and lymphatic invasion (left-sided 32.7% vs. right-sided 23.2%, P < 0.05). Especially, the sigmoid colon and rectum showed higher rates of LNM (12.4% and 12.1%, respectively) than other locations. Patients with left-sided T1 CRC were younger than those with right-sided T1 CRC (64.9 years ±11.5 years vs. 68.7 ± 11.6 years, P < 0.05), as well as significantly lower rates of poorly differentiated carcinoma/mucinous carcinoma than right-sided T1 CRC (11.6% vs. 16.1%, P < 0.05). CONCLUSION: Left-sided T1 CRC, especially in the sigmoid colon and rectum, exhibited higher rates of LNM than right-sided T1 CRC, followed by higher rates of lymphatic invasion. These results suggest that tumor location should be considered in decisions regarding additional surgery after endoscopic resection. TRIAL REGISTRATION: This study was registered with the University Hospital Medical Network Clinical Trials Registry ( UMIN 000032733 ).

[Complete Response of Liver Metastases from a HER2-Positive Gastric Cancer Treated with Combined S-1/Trastuzumab Chemotherapy].

A 74-year-old man with upper abdominal pain and anorexia was referred to our hospital in December 2013. Based on computed tomography(CT)and gastroendoscopy findings, the patient was diagnosed as having advanced gastric cancer with multiple liver metastases(S3, S5, and S6 lesions). Because of high pyloric stenosis, distal gastrectomy Roux-en-Y reconstruction was performed in mid-December 2013. Histopathological findings of the patient were L, Ant-Gre, 35×60 mm, type 2, pT4a(SE), tub2>tub1, int, INF b, ly2, v1(VB), pPM0(95mm), pDM0(15mm), pN0(0/2), HER2(IHC 3+). Postop- eratively, the patient received combined S-1/trastuzumab chemotherapy toward the end of January 2014. The clinical response was PR after 2 courses and clinical CR(cCR)after 4 courses. Because hand-foot syndrome caused by S-1 was prolonged, the dosage was completed in 11 courses. He remains alive 4.5 years after surgery without recurrence. Although ToGA examination showed that trastuzumab was effective for HER 2-positive unresectable gastric cancer, few reported cases showed progression to cCR after the treatment followed by a regimen of trastuzumab without CDDP, and they had good prognosis. Furthermore, in this case, the liver metastases showed complete response without CDDP. Thus, trastuzumab might be a chemotherapy option for patients who have difficulty using platinum analogs, including the elderly patients.

Treatment policy for colonic laterally spreading tumors based on each clinicopathologic feature of 4 subtypes: actual status of pseudo-depressed type.

BACKGROUND AND AIMS: Laterally spreading tumors (LSTs) are originally classified into 4 subtypes. Pseudo-depressed nongranular types (LSTs-NG-PD) are gaining attention because of their high malignancy potential. Previous studies discussed the classification of nongranular (LST-NG) and granular types (LST-G); however, the actual condition or indication for endoscopic treatment of LSTs-NG-PD remains unclear. We aimed to compare the submucosal invasion pattern of LSTs-NG-PD with the other 3 subtypes. METHODS: A total of 22,987 colonic neoplasms including 2822 LSTs were resected endoscopically or surgically at Showa University Northern Yokohama Hospital. In these LSTs, 322 (11.4%) were submucosal invasive carcinomas. We retrospectively evaluated the clinicopathologic features of LSTs divided into 4 subtypes. In 267 LSTs resected en bloc, their submucosal invasion site was further evaluated. RESULTS: The frequency of LSTs in all colonic neoplasms was significantly higher in women (14.9%) than in men (11.0%). Rates of submucosal invasive carcinoma were .8% in the granular homogenous type (LSTs-G-H), 15.2% in the granular nodular mixed type (LSTs-G-M), 8.0% in the nongranular flat elevated type (LSTs-NG-F), and 42.5% in LSTs-NG-PD. Tumor size was associated with submucosal invasion rate in LSTs-NG-F and LSTs-NG-PD (P < .001). The multifocal invasion rate of LSTs-NG-PD (46.9%) was significantly higher than that of LSTs-G-M (7.9%) or LSTs-NG-F (11.8%). In LSTs-NG-PD, the invasion was significantly deeper (≥1000 µm) if observed in 1 site. CONCLUSIONS: For LSTs-G-M and LSTs-NG-F that may have invaded the submucosa, en bloc resection could be considered. Considering that LSTs-NG-PD had a higher submucosal invasion rate, more multifocal invasive nature, and deeper invasion tendency, regardless if invasion was only observed in 1 site, than LSTs-NG-F, we should endoscopically distinguish LSTs-NG-PD from LSTs-NG-F and strictly adopt en bloc resection by endoscopic submucosal dissection or surgery for LSTs-NG-PD. (Clinical trial registration number: UMIN 000020261.).

Depressed Colorectal Cancer: A New Paradigm in Early Colorectal Cancer.

INTRODUCTION: In contrast to most colorectal carcinomas arising from pedunculated or sessile protruded adenomas, submucosal-invasive (pT1) colorectal carcinoma exhibiting a depressed surface (hereinafter, "depressed colorectal carcinoma," identified by means of high-definition endoscopy) is considered to be derived from depressed precursors. We hypothesized that depressed colorectal neoplasms have unique clinicopathological features different that are different from those of protruded and flat colorectal neoplasms. METHODS: We classified 27,129 colorectal neoplasms (909 pT1 carcinomas and 26,220 adenomas) resected between 2001 and 2017 into depressed (211 carcinomas and 109 adenomas), flat (304 carcinomas and 11,246 adenomas), and protruded subtypes (394 carcinomas and 14,865 adenomas) and compared their clinicopathological features. As exploratory analyses of pT1 carcinomas, we conducted whole-exome sequencing for 19 depressed and 8 protruded subtypes and RNA sequencing for 8 depressed and 8 protruded subtypes. RESULTS: pT1 carcinomas were more common in depressed lesions (66%) than in protruded (2.6%) and flat lesions (2.6%) (P < 0.001). Compared with nondepressed pT1 carcinomas, depressed pT1 carcinomas were positively correlated with lymphovascular invasion, tumor budding, and massive submucosal invasion and inversely correlated with the presence of an adenoma component (all P < 0.001). Depressed adenomas were more likely to contain high-grade dysplasia than nondepressed adenomas (49% vs 11%, P < 0.001). A KRAS mutation was observed only in one of the 19 depressed pT1 carcinomas. Relative to protruded carcinomas, depressed carcinomas generally exhibited higher expression of genes related to angiogenesis and epithelial-mesenchymal transition. DISCUSSION: Depressed colorectal neoplasms may harbor a unique combination of malignant histopathological phenotypes and molecular features.

High Serum CA19-9 Concentration Predicts Poor Prognosis in Elderly Patients with Stage IV Colorectal Cancer.

BACKGROUND/AIM: The optimal treatment strategy for elderly patients with stage IV colorectal cancer (CRC) remains controversial due to limited research data. The purpose of this study was to evaluate treatment results and to clarify the prognostic factors, especially poor prognosis factors, in elderly patients with stage IV CRC. METHODS: We retrospectively reviewed the data of 82 elderly patients (aged ≥75 years) with stage IV CRC who underwent surgical treatment at our hospital between April 2001 and March 2017. Factors that affected prognosis and the ability to undergo treatment were analyzed via multivariate analysis. RESULTS: The median overall survival (OS) in the patients with high pretreatment serum carbohydrate antigen 19-9 (CA19-9) concentration (> 370 U/mL) was significantly worse than in those with lower serum CA19-9 concentration (0-370 U/mL) (8.5 vs. 19.2 months, p = 0.0059). In univariate analysis, age (≥80 years) (p = 0.014), performance status of 1-3 (p = 0.028), and high pretreatment serum CA19-9 concentration (p = 0.014) were significant prognostic factors for poor OS. By contrast, resection of the primary tumor (p = 0.024), chemotherapy (p < 0.0001), and resection of distant metastasis (p = 0.0005) were significant prognostic factors for favorable OS. Multivariate analysis showed that a high pretreatment serum CA19-9 concentration was an independent prognostic factor for poor OS (p = 0.01). Meanwhile, resection of the primary tumor (p = 0.033), chemotherapy (p < 0.0001), and resection of distant metastasis (p = 0.0008) were prognostic factors for favorable OS. CONCLUSIONS: A high pretreatment serum CA19-9 concentration (> 370 U/mL) was a reliable predictive factor for poor prognosis, and aggressive treatments should be performed carefully in these patients. Moreover, various treatments, including surgery and chemotherapy, might improve OS in elderly patients with stage IV CRC.

Safety and curability of laparoscopic gastrectomy in elderly patients with gastric cancer.

BACKGROUND: Elderly patients are often considered as a high-risk population for major abdominal surgery due to reduced functional reserve and increased comorbidities. The aim of this study was to assess the safety and curability of laparoscopic gastrectomy in elderly patients with gastric cancer compared with short- and long-term outcomes in non-elderly patients. METHODS: We retrospectively investigated 386 patients who underwent laparoscopic gastrectomy for gastric cancer between January 2007 and December 2015 at the Digestive Disease Center, Showa University, Northern Yokohama Hospital. We categorized the patients into two groups by age: the elderly patients (≥ 75 years old) and the non-elderly patients (< 74 years old). Patient characteristics, clinicopathologic and operative findings, and short- and long-term outcomes were investigated and compared between the two groups. RESULTS: The elderly group showed a significantly higher rate of comorbidities (73.1 vs. 49.2%, P < 0.001), and American Society of Anesthesiologists (ASA) scores ≥ 2 (76.3 vs. 43.7%, P < 0.001), and using anticoagulant agents (25.8 vs. 7.9%, P < 0.001) than the non-elderly group. The postoperative morbidity and mortality did not differ between the two groups (19.4 vs. 18.8%; P = 0.880, 2.2 vs. 0%; P = 0.058). In the multivariate analysis, male sex was the only risk factor for postoperative morbidity after laparoscopic gastrectomy. However, age was not found to be a risk factor. The 5-year overall survival ratio was significantly lower in the elderly group than in the non-elderly group (67.7 vs. 85.0%; P < 0.001). However, the 5-year disease-specific survival ratio was similar in the two groups (84.8 vs. 89.1%; P = 0.071). CONCLUSION: Laparoscopic gastrectomy for gastric cancer could be safely performed in elderly patients with acceptable postoperative morbidity and curability.

Impact of obesity on short- and long-term outcomes of laparoscopy assisted distal gastrectomy for gastric cancer.

BACKGROUND: Laparoscopy assisted distal gastrectomy (LADG) for gastric cancer has been rapidly adopted for the treatment of both early and advanced gastric cancers which need lymph node dissection, but remains difficult procedure, especially in patients with obesity. We evaluated the impact of obesity on short- and long-term outcomes of LADG for gastric cancer. METHODS: We retrospectively investigated 243 patients who underwent LADG for gastric cancer between January 2007 and December 2014. The patients were classified based on their body mass index (BMI) into the Obese (BMI ≥ 25) and Non-Obese (BMI < 25) Groups. Patient characteristics, clinicopathologic and operative findings, and short- and long-term outcomes were investigated and compared between the groups. RESULTS: The groups did not differ in age, sex, American Society of Anesthesiologists score, the presence of comorbidities, or pathologic stage. Operative time (265 ± 46.6 vs. 244 ± 55.6 min; P = 0.007) and estimated blood loss (113 ± 101.4 vs. 66.5 ± 95.2 ml; P = 0.007) were greater in the Obese Group. Fewer lymph nodes were retrieved in the Obese Group (38 ± 23.7 vs. 47.5 ± 24.3; P = 0.004). No differences were evident in postoperative complication rate (20% vs. 17%; P = 0.688) or the duration of postoperative hospital stay (9 ± 8.5 vs. 9 ± 5.1 days; P = 0.283) between the two groups. In the Obese Group, the 5-year overall survival rate was significantly lower than in the Non-Obese Group (67.6% vs. 90.3%; P = 0.036). Furthermore, 5-year disease-specific survival was significantly lower in the Obese Group than in the Non-Obese Group (72.7% vs. 94.9%; P = 0.015). CONCLUSIONS: LADG in patients with obesity could be performed as safe as in patients without obesity, with comparable postoperative results. But obesity may be a poor prognostic factor in gastric cancer.

Fecal Volume after Laparoscopic Low Anterior Resection Predicts Anastomotic Leakage.

BACKGROUND/AIM: Anastomotic leakage (AL) is a major complication after laparoscopic low anterior resection (Lap-LAR). Many surgeons encounter AL following severe postoperative diarrhea. However, little is known about the relationship between postoperative fecal volume and AL. This study determined whether postoperative fecal volume can predict AL. METHODS: A retrospective assessment was performed with data from 176 patients with rectal cancers who underwent Lap-LAR between April 2011 and August 2015. A transanal tube was routinely placed in all cases. The fecal volume from the transanal tube was measured daily. The total fecal volume for 3 days after surgery was compared between the AL and non-AL groups. RESULTS: AL occurred in 11 patients. There were 3 patients with a fecal volume ≥1,000 mL for 3 days after surgery. AL occurred in these 3 patients. In patients with a fecal volume <1,000 mL, the total fecal volume was significantly greater in the AL group than that in the non-AL group (p = 0.0003). The cut-off value of the total fecal volume in AL was 118 mL. CONCLUSIONS: The volume of fecal discharge for 3 days after surgery is associated with the incidence of AL, and a fecal volume ≥118 mL may be a reliable predictor for AL.

Laparoscopic Extirpation of a Schwannoma in the Lateral Pelvic Space.

Schwannomas in the lateral pelvic space are very rare. Here, we report the case of a 48-year-old woman who had a tumor detected in her abdomen by abdominal ultrasonography. Abdominal computed tomography and magnetic resonance imaging revealed a well-defined solid tumor of 65 mm in diameter in the right lateral pelvic space. We performed laparoscopic surgery under a diagnosis of a gastrointestinal tumor or neurogenic tumor. The tumor was safely dissected and freed from the surrounding tissues using sharp and blunt maneuvers. The tumor originated from the right sciatic nerve. Complete laparoscopic extirpation was performed with preservation of the right sciatic nerve. Pathological examination suggested schwannoma. The patient recovered well but had remaining sciatic nerve palsy in her right foot. Laparoscopic extirpation for a schwannoma in the lateral pelvic space was safe and feasible due to the magnified surgical field afforded by laparoscopy.

Morphology as a risk factor for the malignant potential of T2 colorectal cancer.

Currently, depressed type T1 colorectal cancer is often detected and its malignant potential is being revealed. However, few reports have focused on the morphology of T2 colorectal cancer types. The aim of the present retrospective study was to clarify the characteristics of colorectal T2 cancer types derived from depressed type T1 cancer. The present study included 195 patients with colorectal T2 cancer surgically resected at a referral hospital between April 2001 and April 2009. A total of 48 lesions (25%) with lymph node metastasis and 4 (2%) with distant metastasis were found. The lesions were classified by their form during endoscopy into four categories: Group A, depressed type (the periphery consists of normal mucosa); group B, laterally spreading type; group C, protruded type; group D, ulcerative type (the periphery consists of neoplastic mucosa). Tumor size, lymphatic and venous involvement, lymph node metastasis, and distant metastasis were compared between the four categories. The distribution of patients were as follows: Group A, 73 (37%), group B, 26 (13%), group C, 24 (12%) and group D, 72 (37%). The average tumor size for each category was 23, 51, 30 and 36 mm for groups A, B, C and D, respectively. The number of positive findings for lymphatic involvement, venous involvement, lymph node metastasis and distant metastasis for each category were: Group A, 50 (69%), 54 (74%), 19 (26%) and 1 (1%); group B, 14 (54%), 12 (46%), 8 (31%) and 0 (0%); group C, 14 (58%), 8 (33%), 6 (25%) and 0 (0%); group D 35 (49%), 41 (57%), 16 (22%) and 3 (4%). Group A demonstrated a significantly smaller tumor size (P<0.01), and higher rates of lymphatic and venous involvement (P=0.0333 and P=0.0019, respectively). No significant differences were observed between categories with regards to nodal and distant metastases. Of the T2 cancer types, ~40% were the depressed type. Compared with the other forms, depressed type lesions exhibited a smaller tumor size, and higher rates of lymphatic and venous involvement, which suggested these lesions were of a more malignant nature.