Low skeletal muscle radiodensity is a risk factor for adjuvant chemotherapy discontinuation in colorectal cancer.

BACKGROUND: Previously, we reported SMR (skeletal muscle radiodensity) as a potential prognostic marker for colorectal cancer. However, there have been limited studies on the association between SMR and the continuation of adjuvant chemotherapy in colorectal cancer. METHODS: In this retrospective study, 143 colorectal cancer patients underwent curative surgery and adjuvant chemotherapy using the CAPOX regimen. Patients' SMRs were measured from preoperative CT images and divided into low (bottom quarter) and high (top three quarters) SMR groups. We compared chemotherapy cycles, capecitabine and oxaliplatin doses, and adverse effects in each group. RESULTS: The low SMR group had significantly fewer patients completing adjuvant chemotherapy compared to the high SMR group (44% vs. 68%, P < 0.01). Capecitabine and oxaliplatin doses were also lower in the low SMR group. Incidences of Grade 2 or Grade 3 adverse effects did not differ between groups, but treatment discontinuation due to adverse effects was significantly higher in the low SMR group. Logistic regression analysis revealed Stage III disease (odds ratio 18.09, 95% CI 1.41-231.55) and low SMR (odds ratio 3.26, 95% CI 1.11-9.56) as factors associated with unsuccessful treatment completion. Additionally, a higher proportion of low SMR patients received fewer than 2 cycles of chemotherapy (50% vs. 12%). CONCLUSION: The low SMR group showed higher treatment incompletion rates and received lower drug doses during adjuvant chemotherapy. Low SMR independently contributed to treatment non-completion in colorectal cancer patients.

Less demand on stem cell marker-positive cancer cells may characterize metastasis of colon cancer.

BACKGROUND: CD44 and CD133 are stem cell markers in colorectal cancer (CRC). CD44 has distinctive isoforms with different oncological properties like total CD44 (CD44T) and variant CD44 (CD44V). Clinical significance of such markers remains elusive. METHODS: Sixty colon cancer were examined for CD44T/CD44V and CD133 at mRNA level in a quantitative PCR, and clarified for their association with clinicopathological factors. RESULTS: (1) Both CD44T and CD44V showed higher expression in primary colon tumors than in non-cancerous mucosas (p<0.0001), while CD133 was expressed even in non-cancerous mucosa and rather decreased in the tumors (p = 0.048). (2) CD44V expression was significantly associated with CD44T expression (R = 0.62, p<0.0001), while they were not correlated to CD133 at all in the primary tumors. (3) CD44V/CD44T expressions were significantly higher in right colon cancer than in left colon cancer (p = 0.035/p = 0.012, respectively), while CD133 expression were not (p = 0.20). (4) In primary tumors, unexpectedly, CD44V/CD44T/CD133 mRNA expressions were not correlated with aggressive phenotypes, but CD44V/CD44T rather significantly with less aggressive lymph node metastasis/distant metastasis (p = 0.040/p = 0.039, respectively). Moreover, both CD44V and CD133 expressions were significantly decreased in liver metastasis as compared to primary tumors (p = 0.0005 and p = 0.0006, respectively). CONCLUSION: Our transcript expression analysis of cancer stem cell markers did not conclude that their expression could represent aggressive phenotypes of primary and metastatic tumors, and rather represented less demand on stem cell marker-positive cancer cells.

Short-term outcomes of robot-assisted versus conventional laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy: a propensity score-matched analysis.

The benefits of robot-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. Only a few studies have evaluated the safety and feasibility of RALS following neoadjuvant chemoradiotherapy (NCRT). This study aimed to compare the short-term outcomes of RALS versus conventional laparoscopic surgery (CLS) after NCRT for rectal cancer. Propensity score matching of 111 consecutive patients who underwent RALS or CLS after NCRT for rectal adenocarcinoma between February 2014 and February 2022 was performed. Among them, 60 matched patients were enrolled and their short-term outcomes were compared. Although operative time, conversion rate to open laparotomy and blood loss were comparable, the incidence of postoperative complications, including anastomotic leakage, was significantly lower, urinary retention tended to be lower, and the days to soft diet intake and postoperative hospital stay were significantly shorter in the RALS than the CLS group. No postoperative mortality was observed in either group, and there were no significant differences in terms of resection margins and number of lymph nodes dissected. RALS after NCRT for rectal cancer is safe and technically feasible, and has acceptable short-term outcomes. Further studies are required for validation of the long-term oncological outcomes.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study.

INTRODUCTION: Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients. METHODS: Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes. RESULTS: Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%. CONCLUSION: Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Skeletal Muscle Changes Assessed by Preoperative Computed Tomography Images Can Predict the Long-Term Prognosis of Stage III Colorectal Cancer.

Background: Myopenia and myosteatosis are reported to be long-term prognostic factors in patients with colorectal cancer (CRC). However, the established parameters are unsuitable for the Japanese population because their body composition is different from that of the Western population. Objective: We aimed to elucidate the effect of skeletal muscle changes among Japanese adults, measured using preoperative computed tomography (CT) as a prognostic factor in patients with stage III CRC. Patients: We retrospectively analyzed 341 patients diagnosed with stage III CRC. The cross-sectional area (skeletal muscle index: SMI) and mean radiodensity of skeletal muscle (skeletal muscle radiodensity: SMR) were measured using preoperative CT. The optimal sex-specific cutoff value, which was used to divide the patients according to the risk of recurrence, was set for SMI and SMR. Univariate and multivariate analysis were performed to determine the prognostic factors for recurrence-free survival (RFS). Results: The cutoff values of SMI for men and women were set as 48.5 and 41.4, respectively, and those of SMR were 35.0 and 21.7, respectively. Univariate analysis identified low SMI and SMR in men and low SMR in women as the worst prognostic factors for RFS. Multivariate analysis identified low SMI in men and low SMR in women as independent poor prognostic factors for RFS (hazard ratio [HR] = 1.87, 95% confidence interval [CI], 1.08-3.47, P = .03 and HR = 2.49, CI, 1.21-4.95, P = .01). Conclusion: Low SMI in men and low SMR in women were the independent prognostic factors for patients with stage III CRC.

Comparison of short-term outcomes of robotic-assisted and conventional laparoscopic surgery for rectal cancer: A propensity score-matched analysis.

INTRODUCTION: The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS). METHODS: The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group. RESULTS: After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested. CONCLUSION: Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

Timing of re-dosing based on population pharmacokinetic-pharmacodynamics target attainment analysis of cefmetazole in subjects undergoing lower gastrointestinal surgery.

INTRODUCTION: This study was conducted to evaluate the population pharmacokinetics of prophylactic cefmetazole sodium (CMZ) based on the serum concentrations and establish a pharmacodynamics target concentration exceeding the minimum inhibitory concentration (MIC) to design the re-dosing interval. METHODS: Serum (n = 362) samples from 107 individuals were analyzed using a nonlinear mixed-effects model. The pharmacodynamics index obtained was regarded as the probability of maintaining CMZ serum trough exceeding the minimal inhibitory concentration (MIC) of 2 mg/L. This MIC was chosen to account for methicillin-susceptible Staphylococcus aureus (MSSA), E. coli, and Klebsiella pneumoniae RESULTS: The final population pharmacokinetic model was a two-compartment model with linear elimination. Creatinine clearance and body weight were identified as significant covariates influencing the central clearance and volume of distribution in the central compartment. The probability of achieving serum concentrations exceeding the MIC90 for MSSA, E. coli, and Klebsiella pneumoniae for a 1 g dose with a 10 min intravenous infusion was above 90% except for good renal function (CLcr â‰§ 95 mL/min) at 2 h after the initial dose. For patients with good renal function (CLcr â‰§ 95 mL/min), a CMZ of 2 g re-dosing interval seemed necessary to meet the achievement probability. In patients with impaired renal function (CLcr ≤20 mL/min), the probability of achievement exceeded 90% even when the dosing interval was extended to 8 h. CONCLUSIONS: We evaluated re-dosing intervals based on the population pharmacokinetics. Re-dosing intervals should be determined based on renal function.

Pancreas-contactless gastrectomy for gastric cancer prevents postoperative inflammation.

BACKGROUND: Pancreas-related complications after laparoscopic gastrectomy (LG) for gastric cancer can be fatal. We developed a gastrectomy procedure with no pancreas contact to prevent such complications and herein report the surgical outcomes. METHODS: We retrospectively reviewed 182 consecutive patients with gastric cancer who underwent LG at Kitasato University Hospital from January 2017 to January 2020. These patients were divided into a pancreas-contact group (C group) and pancreas-contactless group (CL group) for comparison of postoperative complications, and inflammatory parameters such as body temperature (BT) and C-reactive protein (CRP). RESULTS: Postoperative complications of CDc grade ≧ IIIa were significantly fewer in the CL group than in the C group [0/76 (0%) vs. 6/106 (5.7%), P = 0.035]. The median drain amylase (drain-AMY) on postoperative day 1 (POD1) was significantly lower in the CL group than in the C group (641 vs. 1162 IU/L, P = 0.02), as was BT at POD1 (37.4 °C vs. 37.7 °C, P = 0.04), the patient group with a BT above 37.5 °C at POD3 [5/76 (6.5%) vs. 18/106 (17%), P = 0.037], and those showing a CRP above 20.0 mg/dL at POD3 [5/76 (6.5%) vs. 20/106 (19%), P = 0.018]. CONCLUSIONS: Our technique to prevent pancreas contact during supra-pancreatic lymph node dissection during LG could minimize the inflammatory response and prevent further postoperative complications. Further large-scale, prospective studies are now required.

Association of serum and fat tissue antibiotic concentrations with surgical site infections in lower gastrointestinal surgery.

BACKGROUND: During surgery, the effectiveness of perioperative prophylactic antibiotic administration against surgical site infections is inferred from serum concentrations and not from tissues where local infections occur. This study aimed to measure the serum and tissue concentrations of cefmetazole in colorectal surgery cases to clarify whether there is an association between the incidence of surgical site infections and antibiotic concentrations. METHODS: This prospective cohort study was performed at a single tertiary care center. The data of 105 patients who underwent colorectal surgery between October 2017 and September 2019 were evaluated. The primary outcome was the incidence of surgical site infections. Univariate analysis was performed to investigate the association between surgical site infections, perioperative factors, and the serum and tissue concentrations of cefmetazole. RESULTS: The incidence of surgical site infections was 13/105 (12.4%). Cefmetazole concentrations were measured at initial incision (serum; 101 vs 93.1 mg/L, P = .75, subcutaneous fat tissue; 2.8 vs 3.7 mg/g, P = .15), intestinal resection (serum; 35.1 vs 36.7 mg/L, P = .63, mesenteric adipose tissue; 1.3 vs 1.7 mg/g, P = .55), and at skin closure (serum; 34.5 vs 44.8 mg/L, P = .18, subcutaneous fat tissue; 1.0 vs 2.2 mg/g, P = .09). In univariate analysis with P ≤ .10, cefmetazole concentration in subcutaneous fat tissue at skin closure was found to be a significant risk factor for surgical site infections. Age, additional intraoperative administration of cefmetazole, and creatinine clearance were also significant risk factors for the occurrence of surgical site infections. CONCLUSION: Low subcutaneous fat cefmetazole concentrations at skin closure during gastrointestinal operations may also be involved in the occurrence of surgical site infections.

Real-time automatic surgical phase recognition in laparoscopic sigmoidectomy using the convolutional neural network-based deep learning approach.

BACKGROUND: Automatic surgical workflow recognition is a key component for developing the context-aware computer-assisted surgery (CA-CAS) systems. However, automatic surgical phase recognition focused on colorectal surgery has not been reported. We aimed to develop a deep learning model for automatic surgical phase recognition based on laparoscopic sigmoidectomy (Lap-S) videos, which could be used for real-time phase recognition, and to clarify the accuracies of the automatic surgical phase and action recognitions using visual information. METHODS: The dataset used contained 71 cases of Lap-S. The video data were divided into frame units every 1/30 s as static images. Every Lap-S video was manually divided into 11 surgical phases (Phases 0-10) and manually annotated for each surgical action on every frame. The model was generated based on the training data. Validation of the model was performed on a set of unseen test data. Convolutional neural network (CNN)-based deep learning was also used. RESULTS: The average surgical time was 175 min (± 43 min SD), with the individual surgical phases also showing high variations in the duration between cases. Each surgery started in the first phase (Phase 0) and ended in the last phase (Phase 10), and phase transitions occurred 14 (± 2 SD) times per procedure on an average. The accuracy of the automatic surgical phase recognition was 91.9% and those for the automatic surgical action recognition of extracorporeal action and irrigation were 89.4% and 82.5%, respectively. Moreover, this system could perform real-time automatic surgical phase recognition at 32 fps. CONCLUSIONS: The CNN-based deep learning approach enabled the recognition of surgical phases and actions in 71 Lap-S cases based on manually annotated data. This system could perform automatic surgical phase recognition and automatic target surgical action recognition with high accuracy. Moreover, this study showed the feasibility of real-time automatic surgical phase recognition with high frame rate.

WiNTRLINC1/ASCL2/c-Myc Axis Characteristics of Colon Cancer with Differentiated Histology at Young Onset and Essential for Cell Viability.

BACKGROUND: WiNTRLINC1 is a long non-coding RNA (lncRNA) that positively regulates the Wnt pathway via achaete-scute complex homolog 2 (ASCL2) in colorectal cancer. ASCL2 was recently reported to play a critical role in chemoresistance, however clinical relevance of the WiNTRLINC1/ASCL2 axis remains obscure in colon cancer. PATIENTS AND METHODS: WiNTRLINC1/ASCL2 expression was investigated at messenger RNA (mRNA) level in 40 primary colon cancer tissues and the corresponding normal mucosa tissues, together with Wnt-related genes (c-Myc/PRL-3) and other lncRNAs (H19, HOTAIR, and MALAT1). Knock-down experiments of WiNTRLINC1 clarified its role in their expression and chemoresistance. RESULTS: Real-time quantitative reverse transcriptase-polymerase chain reaction confirmed definite overexpression of WiNTRLINC1 mRNA in primary colon cancer compared with the corresponding normal colon mucosa tissues (p = 0.0005), such as ASCL2, c-Myc, and PRL-3 (p < 0.0001). The four gene expression signatures were tightly associated in the center of the ASCL2 gene (r = 0.72, p < 0.0001) in clinical samples. WiNTRLINC1 was not significantly associated with prognostic factors in colon cancer and other lncRNAs, while the WiNTRLINC1/ASCL2/c-Myc signatures were unique to young-onset colon cancer with differentiated histology. On the other hand, undifferentiated histology was significantly associated with H19 expression. Knockdown of the WiNTRLINC1 gene reduced the expression of ASCL2/c-Myc, but rather augmented PRL-3 at mRNA level, and robustly affected cell viability in colon cancer cell lines. CONCLUSION: The enhanced WiNTRLINC1/ASCL2/c-Myc axis involved in Wnt pathway activation is a common pathway essential for differentiated colon tumorigenesis, especially with young onset, and may be essential for a viable phenotype of colon cancer.

Epigenetic Status of CDO1 Gene May Reflect Chemosensitivity in Colon Cancer with Postoperative Adjuvant Chemotherapy.

BACKGROUND: Cysteine dioxygenase type 1 (CDO1) acts as a tumor suppressor gene, and its expression is regulated by promoter DNA methylation in human cancer. The metabolic product mediated by CDO1 enzyme increases mitochondrial membrane potential (MMP), putatively representing chemoresistance. The aim of this study is to investigate the functional relevance of CDO1 gene in colon cancer with chemotherapy. PATIENTS AND METHODS: We investigated 170 stage III colon cancer patients for CDO1 methylation by using quantitative methylation-specific polymerase chain reaction (PCR). To elucidate the functional role of CDO1 gene in colorectal cancer (CRC) biology, we established cell lines that stably express CDO1 gene and evaluated chemosensitivity, MMP, and tolerability assay including anaerobic environment. RESULTS: Hypermethylation of CDO1 gene was an independent prognostic factor for stage III colon cancer on multivariate prognostic analysis. Surprisingly, patients with CDO1 hypermethylation exhibited better prognosis than those with CDO1 hypomethylation in stage III colon cancer with postoperative chemotherapy (P = 0.03); however, a similar finding was not seen in those without postoperative chemotherapy. In some CRC cell lines, forced expression of CDO1 gene increased MMP accompanied by chemoresistance and/or tolerance under hypoxia. CONCLUSION: CDO1 methylation may be a useful biomarker to increase the number of stage III colon cancer patients who can be saved by adjuvant therapy. Such clinical relevance may represent the functionally oncogenic property of CDO1 gene through MMP activity.

Laparoscopic surgery for locally advanced T4 colon cancer: the long-term outcomes and prognostic factors.

PURPOSE: For locally advanced pathological T4 (pT4) colon cancer, the safety and feasibility of laparoscopic procedures remain controversial. Therefore, this study aimed to assess short-term and long-term outcomes and to identify the prognostic factors in laparoscopic surgery for pT4 colon cancer. METHODS: The study group included 130 patients who underwent laparoscopic radical resection for pT4 colon and rectosigmoid cancer from January 2004 through December 2012. The short-term outcomes, long-term outcomes, and prognostic factors in pT4 colon cancer were analyzed. RESULTS: The median operative time was 205 min, with a median blood loss of 10 ml. The conversion rate was 3.8%, and 13 patients (10.0%) had postoperative complications. The radial resection margin was positive in 1 patient (0.8%). The median follow-up time was 73 months. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 77.2 and 63.5%, respectively. On a multivariate analysis, a male sex [hazard ratio (HR) 3.09, p < 0.001], lymph node ratio ≥ 0.06 (HR 2.35, p = 0.021), tumor diameter < 38 mm (HR 2.57, p = 0.007), and right-sided colon cancer (HR 2.11, p = 0.047) were significantly related to a poor OS. CONCLUSIONS: These results suggest that laparoscopic surgery for pT4 colon cancer is safe and feasible, and the oncological outcomes are acceptable. Based on the present findings, select patients with locally advanced colon cancer should not be excluded from laparoscopic surgery.

[Treatment Strategy for Liver Metastasis of Colorectal Cancer - Including Treatment for Oligometastasis].

The mainstay of treatment for metastatic colorectal cancer is surgery. Therefore, colorectal cancer metastasis is distinctive, compared to other cancer types in which chemotherapy is the main treatment. Initially, Japan experienced medical druglag compared with western countries. However, the use of oxaliplatin for unresectable recurrent metastatic colorectal cancer became available in Japan, as well as in western countries, in 2005. We have since shifted chemotherapeutic regimens from monotherapy to combination therapy with molecular targeted agents. The combination therapy has rapidly become a standard therapy for unresectable metastatic colorectal cancer, and prognosis has dramatically increased for patients with this condition. Herein, we describe the treatment of liver metastasis of colorectal cancer, and surgery and adjuvant or neoadjuvant therapy options for resectable cancer. Furthermore, we focus on conversion therapy for unresectable cancer.

Risk factors for complications after diverting ileostomy closure in patients who have undergone rectal cancer surgery.

PURPOSE: To clarify the risk factors for complications after diverting ileostomy closure in patients who have undergone rectal cancer surgery. METHODS: The study group comprised 240 patients who underwent a diverting ileostomy at the time of lower anterior resection or internal anal sphincter resection, in our department, between 2004 and 2015. Univariate and multivariate analyses of 18 variables were performed to establish which of these are risk factors for postoperative complications. RESULTS: The most common complications were intestinal obstruction and wound infection. Univariate analysis showed that an age of 72 years or older (p = 0.0028), an interval between surgery and closure of 6 months or longer (p = 0.0049), and an operation time of 145 min or longer (p = 0.0293) were significant risk factors for postoperative complications. Multivariate analysis showed that age (odds ratio, 3.4236; p = 0.0025), the interval between surgery and closure (odds ratio, 3.4780; p = 0.0039), and operation time (odds 2.5179; p = 0.0260) were independent risk factors. CONCLUSIONS: Age, interval between surgery and closure, and operation time were independent risk factors for postoperative complications after diverting ileostomy closure. Thus, temporary ileostomy closure should be performed within 6 months after surgery for rectal cancer.

Pain management using acetaminophen throughout postoperative course of laparoscopic colorectal surgery: A case-matched control study.

BACKGROUD: The main advantage of laparoscopic surgery is that it is minimally invasive because of the use of small incisions. An approach using small incisions offers many benefits including attenuation of surgical wound pain. However, the presence of postoperative pain may undermine the advantages of laparoscopic surgery as a minimally invasive technique. In addition, perioperative pain management is an important factor affecting recovery after surgery. This study investigated the usefulness of a multimodal approach to postoperative pain management with acetaminophen as a baseline analgesic after minimally invasive laparoscopic colorectal surgery. MATERIALS AND METHODS: The study included 40 patients who underwent laparoscopic colorectal surgery for colorectal cancer. 20 patients received acetaminophen as a baseline analgesic for postoperative pain management and 20 received epidural anesthesia. RESULTS: The urethral catheter could be removed earlier in the acetaminophen group (2.1 ± 0.22 days postoperatively) compared with the epidural group (4.1 ± 0.45days postoperatively). The frequencies of vertigo were significantly lower in the acetaminophen than epidural group (10.0% and 45.0%, respectively). The frequencies of the use of analgesics on an as-needed basis for postoperative pain relief as well as the variabilities in these frequencies, although not significantly different between the acetaminophen and epidural groups, were lower in the acetaminophen group than the epidural group. CONCLUSION: We herein demonstrated that postoperative pain management with acetaminophen as a baseline analgesic, and without the use of epidural anesthesia, is a safe and useful analgesic modality.

Sutureless functional end-to-end anastomosis using a linear stapler with polyglycolic acid felt for intestinal anastomoses.

BACKGROUND: Gastrointestinal anastomosis remains associated with a considerable burden of morbidity and, in some cases, mortality. Functional end-to-end anastomosis, whilst extremely efficient, is vulnerable to increased intestinal pressure in the immediate postoperative period, which may predispose to development of anastomotic leakage or bleeding. Therefore, there is a requirement for new techniques that facilitate safe and efficacious anastomotic procedures. MATERIALS AND METHODS: This study examined the clinical application of functional end-to-end anastomosis with a stapler that automatically applies a bioabsorbable polyglycolic acid sheet (Endo GIA™ Reinforced Reload with Tri-Staple™ Technology). A porcine model was used to examine functional end-to-end anastomosis with and without application of a bioabsorbable polyglycolic acid sheet. As the crotch of the anastomosis is considered the weakest point, a probe was used to test the integrity of these anastomoses. Furthermore, we performed functional end-to-end anastomosis using the Endo GIA™ Reinforced stapler in a clinical series of 20 patients undergoing gastrointestinal tract resection. In all cases, functional end-to-end anastomosis was performed without suture reinforcement. RESULTS: Small intestine anastomoses in the animal study exhibited no weakness at the crotch of the anastomosis, as tested with a probe, suggesting an increased resiliency to conventional complications of functional end-to-end anastomosis. In the clinical population, no postoperative complications were noted. No adhesive intestinal obstruction was noted. CONCLUSION: Sutureless functional end-to-end anastomosis using the Endo GIA™ Reinforced appears to be safe, efficacious, and straightforward. Reinforcement of the crotch site with a bioabsorbable polyglycolic acid sheet appears to mitigate conventional problems with crotch-site vulnerability.

Risk factors for perineal wound infection after abdominoperineal resection of advanced lower rectal cancer.

PURPOSE: Abdominoperineal resection (APR) of advanced lower rectal cancer carries a high incidence of perineal wound infection. The aim of this study was to retrospectively evaluate risk factors for perineal wound infection after APR. METHODS: The study group comprised 154 patients who underwent APR for advanced lower rectal cancer in our department from January 1990 through December 2012. The following 15 variables were studied as potential risk factors for perineal wound infection: sex, age, body-mass index, American Society of Anesthesiologists score, diabetes mellitus, preoperative albumin level, preoperative hemoglobin level, neoadjuvant chemoradiotherapy(NCRT), surgical procedure (open surgery vs. laparoscopic surgery), operation time, bleeding volume, intraoperative transfusion, tumor diameter, invasion depth, and histopathological stage. RESULTS: Among the 154 patients, 30 (19%) had perineal wound infection. Univariate analysis showed that a hemoglobin level of ≤11 g/dL (p = 0.001) and NCRT (p = 0.001) were significantly related to perineal wound infection. On multivariate analysis including the preoperative albumin level (≤3.5 g/dL) in addition to the above 2 variables, neoadjuvant chemoradiotherapy (NCRT) was the only independent risk factor for perineal wound infection. Perineal wound infection developed in 31% of patients who received NCRT, as compared with 10% of patients who did not receive NCRT. The relative risk of perineal infection in the former group was 4.092 as compared with the latter group (p = 0.0002). CONCLUSIONS: NCRT is a risk factor for perineal wound infection after APR in patients with advanced lower rectal cancer.

Secure overlap stapling using a linear stapler with bioabsorbable polyglycolic acid felt.

INTRODUCTION: Despite the availability of various anastomosis techniques, postoperative anastomotic complications such as anastomosis failure and bleeding develop in some patients. Automatic suturing devices have been widely used for gastrointestinal anastomosis. However, overly thick or thin tissue, displacement of tissue, and the creation of a staple-on-staple site may lead to incomplete staple formation. These factors are considered to be related to postoperative complications such as anastomosis failure. METHODS: The iDrive™ Ultra Powered Stapling System was used to fire the automatic suturing device. Two types of automatic suturing devices were employed: (i) the Endo GIA™ Reinforced Reload with Tri-Staple™ Technology with a cartridge with the reinforcement material Neoveil™; and (ii) the Endo GIA™ with Tri-Staple™ Technology with no reinforcement material. Stapling was performed using a two-stage crossing approach to make a staple-on-staple site. RESULTS: The rates of complete formation with the Endo GIA™ with Tri-Staple™ Technology were 95.6 ± 0.6% for stomach tissue and 95.6 ± 2.3% for colon tissue, which is thinner than stomach tissue. In contrast, the rates of complete formation with the Endo GIA™ Reinforced Reload with Tri-Staple™ Technology were 99.3 ± 1.27% for stomach tissue and 100.0 ± 0.0% for colon tissue. CONCLUSION: Our results showed that the Endo GIA™ Reinforced Reload with Tri-Staple™ Technology had higher rates of complete staple formation than the Endo GIA™ with Tri-Staple™ Technology, irrespective of tissue thickness and the presence of a staple-on-staple site.

[A Patient Who Underwent Resection of Liver Metastases after Receiving Systemic Chemotherapy for Advanced Rectal Cancer and Multiple Liver Metastases].

The patient was a 52-year-old man who had a positive fecal occult-blood test on a medical check-upi n April 2015 and was referred to our hospital in June. Detailed preoperative examinations resulted in a diagnosis of cancer of the lower rectum, multiple liver metastases, and clinical Stage IV . A biopsy showed moderately differentiated tubular adenocarcinoma. All-RAS was wild type, and the patient was asymptomatic. Unresectable advanced rectal cancer was diagnosed, and the patient was scheduled to receive systemic chemotherapy. The patient received a total of 16 courses of combination chemotherapy with 5- fluorouracil, Leucovorin, and oxaliplatin(FOLFOX)plus panitumumab, starting in October 2015. In July 2016, Colonoscopy showed scar findings at the site of the primary rectal cancer lesion. A biopsy revealed no cancer cells. It was difficult to identify the primary lesion on computed tomography, and there was no evidence of clinically significant lymphadenopathy. Positronemission tomography and computed tomography showed shrinkage of the liver metastases, with no accumulation of tracer in the primary lesion or lymph nodes. The primary lesion had a clinical complete response(CR), and the metastatic lesions had a clinical partial response(PR). In October 2016, laparoscopic partial hepatectomy was performed to treat the liver metastases. Histologic examination showed that the liver metastases were from rectal cancer. It is currently under observation.