Safety and efficacy of autologous blood tattooing for preoperative colonic localization: a comparative study with conventional India ink tattooing.

BACKGROUND: India ink has been a popular choice for a tattooing agent in preoperative endoscopic localization but often results in unfavorable effects. Subsequently, autologous blood tattooing has arisen as an alternative option. Due to the limited availability of comparative studies on the matter, we conducted a study to compare the perioperative outcomes associated with India ink tattooing versus autologous blood tattooing. METHODS: A total of 96 patients who underwent minimally invasive surgical procedures for left-sided colonic neoplasm following preoperative endoscopic localization were included in the study. These patients were categorized into two groups: 36 patients who received India ink tattooing and 60 patients who underwent autologous blood tattooing. The perioperative outcomes including procedure-related outcomes and postoperative outcomes were compared between the two groups. RESULTS: There was no significant difference in visibility and spillage of tattooing agent between India ink group and autologous blood group. However, India ink group showed a higher incidence of post-tattooing fever, higher level of postoperative C-reactive protein level, longer time to first flatus, resumption of surgical soft diet, and duration of hospital stay, and a higher occurrence of postoperative complications including ileus and surgical site infection compared with the autologous blood group. In the multivariate analysis, India ink tattooing was significantly associated with the occurrence of postoperative complications. In the subgroup analysis involving patients with intraperitoneal spillage, the autologous blood group demonstrated significantly favorable perioperative outcomes compared with India ink group. CONCLUSIONS: Autologous blood tattooing demonstrated comparable visibility and enhanced safety, establishing it as a potential alternative to India ink for preoperative endoscopic localization.

Oncologic relevance of genetic alterations in sporadic synchronous and solitary colorectal cancer: a retrospective multicenter study.

BACKGROUND: Oncologic impact of genetic alteration across synchronous colorectal cancer (CRC) still remains unclear. This study aimed to compare the oncologic relevance according to genetic alteration between synchronous and solitary CRC with performing systematic review. METHODS: Multicenter retrospective analysis was performed for CRC patients with curative resection. Genetic profiling was consisted of microsatellite instability (MSI) testing, RAS (K-ras, and N-ras), and BRAF (v-Raf murine sarcoma viral oncogene homolog B1) V600E mutation. Multivariate analyses were conducted using logistic regression for synchronicity, and Cox proportional hazard model with stage-adjusting for overall survival (OS) and disease-free survival (DFS). RESULTS: It was identified synchronous (n = 36) and solitary (n = 579) CRC with similar base line characteristics. RAS mutation was associated to synchronous CRC with no relations of MSI and BRAF. During median follow up of 77.8 month, Kaplan-meier curves showed significant differences according to MSI-high for OS, and in RAS, and BRAF mutation for DFS, respectively. In multivariable analyses, RAS and BRAF mutation were independent factors (RAS, HR = 1.808, 95% CI = 1.18-2.77, p = 0.007; BRAF, HR = 2.417, 95% CI = 1.32-4.41, p = 0.004). Old age was independent factor for OS (HR = 3.626, 95% CI = 1.09-12.00, p = 0.035). CONCLUSION: This study showed that oncologic outcomes might differ according to mutation burden characterized by RAS, BRAF, and MSI between synchronous CRC and solitary CRC. In addition, our systematic review highlighted a lack of data and much heterogeneity in genetic characteristics and survival outcomes of synchronous CRC relative to that of solitary CRC.

Laparoscopic repair of perforated peptic ulcer: a multicenter, propensity score matching analysis.

BACKGROUND: Perforated peptic ulcer (PPU) is a common emergency condition requiring surgery using laparoscopy or open repair of the perforated site. The aim of this study was to assess the role of laparoscopic surgery (LS) based on the safety and efficacy for PPU. METHODS: Medical records of the consecutive patients who underwent LS or open surgery (OS) for PPU at five hospitals between January 2009 and December 2019 were retrospectively reviewed. After propensity score matching, short-term perioperative outcomes were compared between LS and OS in selected patients. RESULTS: Among the 598 patients included in the analysis, OS was more frequently performed in patients with worse factors, including older age, a higher American Society of Anesthesiologists score, more alcohol use, longer symptom duration, a higher Boey score, a higher serum C-reactive protein level, a lower serum albumin level, and a larger-diameter perforated site. After propensity score matching, 183 patients were included in each group; variables were well-balanced between-groups. Postoperative complications were not different between groups (24.6% LS group vs. 31.7% OS group, p = 0.131). However, postoperative length of hospital stay (10.03 vs. 12.53 days, respectively, p = 0.003) and postoperative time to liquid intake (3.75 vs. 5.26 days, p < 0.001) were shorter in the LS group. CONCLUSIONS: LS resulted in better functional recovery than OS and can be safely performed for treatment of PPU. When performed by experienced surgeons, LS is an alternative option, even for hemodynamically unstable patients.

Clinical outcomes of laparoscopic versus open surgery for repairing colonoscopic perforation: a multicenter study.

PURPOSE: We conducted this study to compare the perioperative outcomes of laparoscopic surgery (LS) vs. open surgery (OS) for repairing colonoscopic perforation, and to evaluate the possible predictors of complications. METHOD: We reviewed the medical records of patients who underwent surgical repair of colonoscopic perforation by LS or OS between January 2005 and June 2019 at six Hallym University-affiliated hospitals. Multivariable analysis was performed to identify the predictors of postoperative complications. RESULTS: Of the total 99 patients, 40 underwent OS and 59 underwent LS. The postoperative hospital stay and the time to resuming a soft diet were shorter in the LS group than in the OS group (P = 0.017 and 0.026, respectively). The complication rate and Clavien-Dindo classification were not significantly different between the two groups. Multivariable analysis revealed that an American Society of Anesthesiologists score (ASA) ≥ 3 and switching from non-operative management to surgical treatment were independently associated with complications (P = 0.025 and 0.010, respectively). CONCLUSION: LS may be a safe alternative to OS for repairing colonoscopic perforation with a shorter postoperative hospital stay and time to resuming a soft diet. Patients with an ASA score ≥ 3 and those with changes to their planned treatment should be monitored carefully to minimize their risk of complications.

Clinical outcomes of sigmoid volvulus and risk factors for its recurrence: a multicenter study in Korea.

PURPOSE: Sigmoid volvulus is one of the leading causes of colonic obstruction. The aims of this study were to review the treatment characteristics and clinical outcomes of patients diagnosed with sigmoid volvulus over 10 years at five university-affiliated hospitals in Korea, and to identify possible risk factors for its recurrence. METHODS: Retrospective review was performed for medical records of patients who were diagnosed with sigmoid volvulus and managed surgically or conservatively at the five Hallym University-affiliated hospitals between January 2005 and July 2018. RESULTS: A total of 69 patients were diagnosed, of whom 11 patients underwent emergency surgery and 58 patients were conservatively managed. Non-operative management was successful in 53 of 58 patients (91.4%) at initial admission. Of the non-operative managed patients, six patients required emergency surgery due to unsuccessful decompression or recurrence whereas 23 patients underwent regular surgery for definitive treatment. And overall recurrence rate and mortality rate were 25.8% (15/58) and 1.7% (1/58), respectively. A total of 40 patients underwent surgery; 23 underwent regular surgery and 17 underwent emergency surgery. Restoration of bowel continuity was more frequently performed in the regular surgery group than in the emergency surgery group (87.0% vs 52.9%, P = 0.03). In multivariable analysis, only non-operative management at the initial admission (P = 0.029) was independently associated with recurrence. CONCLUSION: Although non-operative treatment can be initially attempted, surgery is required for preventing recurrence. Regular surgery should be considered to restore continuity of the bowel.

Prognostic Impact of Tumor-Budding Grade in Stages 1-3 Colon Cancer: A Retrospective Cohort Study.

BACKGROUND: Tumor budding is associated with adverse histology and is a predictor of lymph node metastasis. However, it remains unclear whether tumor budding is predictive of a poor prognosis for colon cancer patients. This study sought to investigate the prognostic significance of tumor budding in colon cancer. METHODS: This study evaluated 4196 colon cancer patients who underwent radical surgery from 2007 to 2013 at a single institution. The patients were categorized according to tumor-budding status. Adjustment was made for using propensity score-matched analysis, and both disease-free survival (DFS) and overall survival (OS) were compared between the groups. RESULTS: Among the 4196 patients, 2269 had low budding (< 5 buds), 1312 had intermediate budding (5-9 buds), and 615 had high budding (≥ 10 buds). High budding was associated with adverse histologic features such as elevated levels of preoperative carcinoembryonic antigen, advanced stage, poor histology, and the presence of lymphatic/vascular/perineural invasion. Before matching, DFS and OS decreased significantly with increasing tumor budding. After matching, the difference in survival between the low- and intermediate-budding groups disappeared. However, the OS and DFS rates for the high-budding group were significantly lower than for the other two groups. In the multivariate analysis of prognostic factors, high budding was an independent poor prognostic factor in DFS and OS, whereas tumor-budding positivity itself was not an independent prognostic factor. CONCLUSION: Tumor-budding grade rather than tumor-budding positivity was an independent prognostic factor in colon cancer.

Oncologic outcome of colorectal cancer patients over age 80: a propensity score-matched analysis.

PURPOSE: It remains unclear whether old age is a poor prognostic factor in colorectal cancer (CRC). We compared oncologic outcomes in CRC patients according to age, using 80 as the dividing point. METHODS: CRC patients who underwent radical surgery from 2000 to 2011 were evaluated. We performed matched and adjusted analyses comparing oncologic outcomes between patients with ≥ 80 and < 80 years old. RESULTS: Among 9562 patients, 222 were elderly. The median age was 82.0 years in elderly patients and 59.0 years in young patients. Elderly patients received less neoadjuvant or adjuvant therapy compared to young patients (p < 0.001). After recurrence, significantly fewer elderly patients received additional treatments (p < 0.001). Before matching, disease-free survival (DFS) and cancer-specific survival (CSS) were significantly lower for elderly patients compared to those for young patients (p < 0.001 and p < 0.001, respectively). After matching, DFS and CCS were not significantly different between the two groups (p = 0.400 and p = 0.267, respectively). In a multivariate analysis for prognostic factors, old age was not an independent poor prognostic factor of DFS and CCS (p = 0.619 and p = 0.137, respectively). CONCLUSIONS: Elderly patients aged ≥ 80 years with CRC had similar oncologic outcome to young patients, and age was not an independent prognostic factor.

Operative Method for Transverse Colon Carcinoma: Transverse Colectomy Versus Extended Colectomy.

BACKGROUND: The type of surgery performed for primary transverse colon cancer varies based on tumor characteristics and surgeon perspective. The optimal oncological outcome following different surgical options has not been clearly established, and transverse colectomy has shown oncological equivalence only in small cohort studies. OBJECTIVE: Our aim was to compare long-term oncological outcomes after transverse colectomy versus extended resection for transverse colon cancer. DESIGN: This study is a retrospective review of prospectively collected data. SETTING: This study was conducted at a tertiary care hospital. METHOD: All patients treated for transverse colon cancer at the Samsung Medical Center between 1995 and 2013 were included. MAIN OUTCOME MEASURES: Oncological outcomes were compared between 2 groups of patients: a transverse colectomy group and an extended colectomy group (which included extended right hemicolectomy and left hemicolectomy). RESULTS: A total of 1066 patients were included, of whom 750 (70.4%) underwent extended right hemicolectomy, 127 (11.9%) underwent transverse colectomy, and 189 (17.7%) underwent left hemicolectomy. According to univariate analysis, surgical approach, histological type, tumor morphology, cancer T and N stage, cancer size, and lymphovascular invasion were significant factors contributing to disease-free survival (DFS). However, as seen in multivariate analysis, only node-positive disease (HR = 2.035 (1.188-3.484)), tumors with ulcerative morphology (HR = 3.643 (1.132-11.725)), and the presence of vascular invasion (HR = 2.569 (1.455-4.538)) were significant factors for DFS. Further analysis with a propensity-matched cohort between the transverse and extended colectomy groups demonstrated no significant differences in DFS and overall survival. LIMITATIONS: This study was limited because it was performed at a single institution and it was retrospective in nature. CONCLUSION: In terms of perioperative and oncological outcomes, transverse colectomy and extended colectomy did not differ despite a shorter specimen length and fewer lymph nodes harvested in the transverse colectomy group. Independent prognostic factors for DFS were node-positive disease, the presence of vascular invasion, and ulcerative morphology.

Features of Late Recurrence Following Transanal Local Excision for Early Rectal Cancer.

BACKGROUND: Transanal local excision has recently received attention as an alternative to radical surgery for early rectal cancer. Recurrence usually occurs within 5 years after surgery, but recurrences later than this have also been reported. OBJECTIVE: The aim of this study was to investigate the incidence and risk factors of recurrence in patients who have early rectal cancer 10 years after transanal local excision. DESIGN: Patients with early rectal cancer who underwent transanal local excision from October 1994 to December 2010 were retrospectively reviewed. We reviewed the demographics and clinicopathologic features of primary lesions and analyzed the incidence and risk factors of recurrence. SETTINGS: This investigation was conducted at a tertiary university hospital. PATIENTS: A total of 295 patients who underwent transanal local excision for pTis (n = 155) or pT1 (n = 140) early rectal cancer were included in the analysis. INTERVENTION: Transanal local excision was performed for each patient to excise primary rectal lesions. MAIN OUTCOME MEASURES: The primary end point of this study was the incidence of recurrence, especially late recurrence. The secondary end point was risk factors for recurrence. RESULTS: The 10-year cumulative local recurrence rate was 6.7% in pTis and 18.0% in pT1 patients. The rate of late local recurrence was 2.8% in pTis and 3.7% in pT1 patients. There was no evidence of late systemic recurrence 5 years after transanal local excision. In pT1 patients, a higher risk of recurrence was associated with an invasion depth of sm3, the presence of lymphovascular invasion, and a positive resection margin. LIMITATION: The main limitation of this study is its retrospective nature. CONCLUSIONS: Late recurrence can occur in patients with early rectal cancer who have undergone transanal local excision. Transanal local excision can be performed in selective patients with biologically favorable tumors, and 10-year postoperative surveillance should be considered for these patients.

Performance reporting design in artificial intelligence studies using image-based TNM staging and prognostic parameters in rectal cancer: a systematic review.

PURPOSE: The integration of artificial intelligence (AI) and magnetic resonance imaging in rectal cancer has the potential to enhance diagnostic accuracy by identifying subtle patterns and aiding tumor delineation and lymph node assessment. According to our systematic review focusing on convolutional neural networks, AI-driven tumor staging and the prediction of treatment response facilitate tailored treat-ment strategies for patients with rectal cancer. METHODS: This paper summarizes the current landscape of AI in the imaging field of rectal cancer, emphasizing the performance reporting design based on the quality of the dataset, model performance, and external validation. RESULTS: AI-driven tumor segmentation has demonstrated promising results using various convolutional neural network models. AI-based predictions of staging and treatment response have exhibited potential as auxiliary tools for personalized treatment strategies. Some studies have indicated superior performance than conventional models in predicting microsatellite instability and KRAS status, offer-ing noninvasive and cost-effective alternatives for identifying genetic mutations. CONCLUSION: Image-based AI studies for rectal can-cer have shown acceptable diagnostic performance but face several challenges, including limited dataset sizes with standardized data, the need for multicenter studies, and the absence of oncologic relevance and external validation for clinical implantation. Overcoming these pitfalls and hurdles is essential for the feasible integration of AI models in clinical settings for rectal cancer, warranting further research.

Advanced Preoperative Clinical Stage Is Associated With More Lymph Node Harvest in Patients With Right Colon Cancer.

PURPOSE: The adequacy of lymph node (LN) harvest is important in oncological colon cancer resections. While several studies have suggested factors influencing LN yield in colon cancer, limited data are available only regarding right hemicolectomies with complete mesocolic excision (CME) and central vessel ligation (CVL). METHODS: A retrospective analysis was conducted on 169 patients who underwent right hemicolectomies with CME and CVL for right-sided colon cancer between February 2019 and March 2023. The patients were divided into 2 groups: groups with ≤24 LN yield and >24 LN yield, and the patient, surgical, and pathologic factors, which could potentially influence the LN yield, were analyzed. RESULTS: Younger age, lower American Society of Anesthesiologists (ASA) classification, and advanced clinical TNM (cTNM) stage among patient factors, the presence of obstructions regarding the surgical factors, and the presence of desmoplastic tumor reaction in the pathologic factors were more likely to harvest >24 LNs. In a multivariate analysis, younger age, lower ASA classification, advanced cTNM stage, and an ileocolic artery (ICA) crossing pattern posterior to the superior mesenteric vein (SMV) were independently associated with a >24 LN harvest. Patients with cTNM 3,4 showed the tendency of > 24 LN yield consistently within each subgroup, irrespective of the age, ASA classification, and ileocolic artery crossing pattern. CONCLUSIONS: Our investigation revealed a significant correlation between the advanced preoperative clinical stage and an increased number of harvested lymph nodes (LNs) in patients undergoing right hemicolectomies with CME a CVL. The observed association is potentially influenced by tumor aggressiveness and the extent of surgical resection performed by the surgeon. To elucidate the intricate relationship between surgical outcomes and the quantity of LN harvest in patients subjected to standardized CME and CVL for right-sided colon cancer, further dedicated research is warranted.

Short-term outcomes of single-incision robotic colectomy versus conventional multiport laparoscopic colectomy for colon cancer.

Since the da Vinci SP (dVSP) surgical system was introduced, single-incision robotic surgery (SIRS) for colorectal diseases has gained increasing acceptance. Comparison of the short-term outcomes between SIRS using dVSP and those of conventional multiport laparoscopic surgery (CMLS) was performed to verify its efficacy and safety in colon cancer. The medical records of 237 patients who underwent curative resection for colon cancer by a single surgeon were retrospectively reviewed. Patients were divided into two groups according to surgical modality: SIRS (RS group) and CMLS (LS group). Intra- and postoperative outcomes were analyzed. Of the 237 patients, 140 were included in the analysis. Patients in the RS group (n = 43) were predominantly female, younger, and had better general performance than those in the LS group (n = 97). The total operation time was longer in the RS group than in the LS group (232.8 ± 46.0 vs. 204.1 ± 41.7 min, P < 0.001). The RS group showed faster first flatus passing (2.5 ± 0.9 vs. 3.1 ± 1.2 days, P = 0.003) and less opioid analgesic requirement (analgesic withdrawal within 3 postoperative days: 37.2% vs. 18.6%, P = 0.018) than the LS group. The RS group showed a higher immediate postoperative albumin level (3.9 ± 0.3 vs. 3.6 ± 0.4 g/dL, P < 0.001) and lower C-reactive protein level (6.6 ± 5.2 vs. 9.3 ± 5.5 mg/dL, P = 0.007) than the LS group during the postoperative period. On multivariate analysis after adjusting for deviated patient characteristics, no significant difference was observed in short-term outcomes, except for operation time. SIRS with dVSP showed short-term outcomes comparable with those of CMLS for colon cancer.

Prognostic Value of Artificial Intelligence-Driven, Computed Tomography-Based, Volumetric Assessment of the Volume and Density of Muscle in Patients With Colon Cancer.

OBJECTIVE: The prognostic value of the volume and density of skeletal muscles in the abdominal waist of patients with colon cancer remains unclear. This study aimed to investigate the association between the automated computed tomography (CT)-based volume and density of the muscle in the abdominal waist and survival outcomes in patients with colon cancer. MATERIALS AND METHODS: We retrospectively evaluated 474 patients with colon cancer who underwent surgery with curative intent between January 2010 and October 2017. Volumetric skeletal muscle index and muscular density were measured at the abdominal waist using artificial intelligence (AI)-based volumetric segmentation of body composition on preoperative pre-contrast CT images. Patients were grouped based on their skeletal muscle index (sarcopenia vs. not) and muscular density (myosteatosis vs. not) values and combinations (normal, sarcopenia alone, myosteatosis alone, and combined sarcopenia and myosteatosis). Postsurgical disease-free survival (DFS) and overall survival (OS) were analyzed using univariable and multivariable analyses, including multivariable Cox proportional hazard regression. RESULTS: Univariable analysis showed that DFS and OS were significantly worse for the sarcopenia group than for the non-sarcopenia group (P = 0.044 and P = 0.003, respectively, by log-rank test) and for the myosteatosis group than for the non-myosteatosis group (P < 0.001 by log-rank test for all). In the multivariable analysis, the myosteatotic muscle type was associated with worse DFS (adjusted hazard ratio [aHR], 1.89 [95% confidence interval, 1.25-2.86]; P = 0.003) and OS (aHR, 1.90 [95% confidence interval, 1.84-3.04]; P = 0.008) than the normal muscle type. The combined muscle type showed worse OS than the normal muscle type (aHR, 1.95 [95% confidence interval, 1.08-3.54]; P = 0.027). CONCLUSION: Preoperative volumetric sarcopenia and myosteatosis, automatically assessed from pre-contrast CT scans using AI-based software, adversely affect survival outcomes in patients with colon cancer.

Trans-abdominal single-incision robotic surgery with the da Vinci SP® surgical system for 8 cases of retrorectal tumour.

BACKGROUND: This study aimed to evaluate transabdominal single-incision robotic surgery using the da Vinci SP (dVSP, Intuitive Surgical, Sunnyvale, CA, USA) surgical system for retrorectal tumours. METHODS: Eight patients who underwent surgical excision of retrorectal tumours using the dVSP surgical system were retrospectively analysed. RESULTS: Five patients (62.5%) had tumours positioned above the levator ani muscle, two (25.0%) had that extending across the levator ani muscle, and one (12.5%) had that located below the levator ani muscle. All surgical procedures were successfully completed without any intraoperative complications. The median operative, docking, and console times were 198, 6, and 145 min, respectively. Two patients (25.0%) experienced postoperative complications classified as Clavien-Dindo grade II. The median duration of follow-up was 6.5 months, and no recurrence was observed. CONCLUSIONS: In our early experience of eight patients, retrorectal tumours can be safely excised with the dVSP surgical system, even at very low tumour levels.

Exosomes Derived from Colon Cancer Cells Promote Tumor Progression and Affect the Tumor Microenvironment.

Cancer-cell-derived exosomes confer oncogenic properties in their tumor microenvironment and to other cells; however, the exact mechanism underlying this process is unclear. Here, we investigated the roles of cancer-cell-derived exosomes in colon cancer. Exosomes were isolated from colon cancer cell lines, HT-29, SW480, and LoVo, using an ExoQuick-TC kit, identified using Western blotting for exosome markers, and characterized using transmission electron microscopy and nanosight tracking analysis. The isolated exosomes were used to treat HT-29 to evaluate their effect on cancer progression, specifically cell viability and migration. Cancer-associated fibroblasts (CAFs) were obtained from patients with colorectal cancer to analyze the effect of the exosomes on the tumor microenvironment. RNA sequencing was performed to evaluate the effect of the exosomes on the mRNA component of CAFs. The results showed that exosome treatment significantly increased cancer cell proliferation, upregulated N-cadherin, and downregulated E-cadherin. Exosome-treated cells exhibited higher motility than control cells. Compared with control CAFs, exosome-treated CAFs showed more downregulated genes. The exosomes also altered the regulation of different genes involved in CAFs. In conclusion, colon cancer-cell-derived exosomes affect cancer cell proliferation and the epithelial-mesenchymal transition. They promote tumor progression and metastasis and affect the tumor microenvironment.

Differentiation of Adipose-Derived Stem Cells into Smooth Muscle Cells in an Internal Anal Sphincter-Targeting Anal Incontinence Rat Model.

OBJECTIVE: Studies on development of an anal incontinence (AI) model targeting smooth muscle cells (SMCs) of the internal anal sphincter (IAS) have not been reported. The differentiation of implanted human adipose-derived stem cells (hADScs) into SMCs in an IAS-targeting AI model has also not been demonstrated. We aimed to develop an IAS-targeting AI animal model and to determine the differentiation of hADScs into SMCs in an established model. MATERIALS AND METHODS: The IAS-targeting AI model was developed by inducing cryoinjury at the inner side of the muscular layer via posterior intersphincteric dissection in Sprague-Dawley rats. Dil-stained hADScs were implanted at the IAS injury site. Multiple markers for SMCs were used to confirm molecular changes before and after cell implantation. Analyses were performed using H&E, immunofluorescence, Masson's trichrome staining, and quantitative RT-PCR. RESULTS: Impaired smooth muscle layers accompanying other intact layers were identified in the cryoinjury group. Specific SMC markers, including SM22α, calponin, caldesmon, SMMHC, smoothelin, and SDF-1 were significantly decreased in the cryoinjured group compared with levels in the control group. However, CoL1A1 was increased significantly in the cryoinjured group. In the hADSc-treated group, higher levels of SMMHC, smoothelin, SM22α, and α-SMA were observed at two weeks after implantation than at one week after implantation. Cell tracking revealed that Dil-stained cells were located at the site of augmented SMCs. CONCLUSIONS: This study first demonstrated that implanted hADSc restored impaired SMCs at the injury site, showing stem cell fate corresponding to the established IAS-specific AI model.

A systematic review of translation and experimental studies on internal anal sphincter for fecal incontinence.

The complexity in the molecular mechanism of the internal anal sphincter (IAS) limits preclinical or clinical outcomes of fecal incontinence (FI) treatment. So far, there are no systematic reviews of IAS translation and experimental studies that have been reported. This systematic review aims to provide a comprehensive understanding of IAS critical role in FI. Previous studies revealed the key pathway for basal tone and relaxation of IAS in different properties as follows; calcium, Rho-associated, coiled-coil containing serine/threonine kinase, aging-associated IAS dysfunction, oxidative stress, renin-angiotensin-aldosterone, cyclooxygenase, and inhibitory neurotransmitters. Previous studies have reported improved functional outcomes of cellular treatment for regeneration of dysfunctional IAS, using various stem cells, but did not demonstrate the interrelationship between those results and basal tone or relaxation-related molecular pathway of IAS. Furthermore, these results have lower specificity for IAS-incontinence due to the included external anal sphincter or nerve injury regardless of the cell type. An acellular approach using bioengineered IAS showed a physiologic response of basal tone and relaxation response similar to human IAS. However, in both cellular and acellular approaches, the lack of human IAS data still hampers clinical application. Therefore, the IAS regeneration presents more challenges and warrants more advances.

Neoadjuvant chemoradiotherapy determines the prognostic impact of anastomotic leakage in advanced rectal cancer.

Purpose: The prognostic impact of anastomotic leakage (AL) in rectal cancer remains uncertain. We investigated the prognostic significance of AL in rectal cancer patients who underwent curative surgery, especially in terms of chemoradiotherapy. Methods: A total of 1,818 rectal cancer patients who underwent radical surgery from 2011 to 2015 were retrospectively evaluated. We categorized patients according to AL and compared survival outcomes between the groups before and after matching. In locally advanced rectal cancer patients, we classified patients according to neoadjuvant chemoradiotherapy (nCRT) or adjuvant chemotherapy (aCTx) and analyzed survival outcomes according to AL in each group. Results: Before matching, overall survival (OS) was significantly worse in the AL (+) group compared to the AL (-) group (P = 0.004). In matched patients, there were no differences in disease-free survival (DFS) and OS between groups (P = 0.423 and P = 0.083, respectively). In subgroup analysis for locally advanced rectal cancer, patients were classified as follows: nCRT (+) and aCTx (+) group; nCRT (+) and aCTx (-) group; nCRT (-) and aCTx (+) group; and nCRT (-) and aCTx (-) group. In the nCRT (-) and aCTx (+) group, patients with AL exhibited significantly worse DFS than patients without AL (P = 0.040). In the other 3 groups, there were no differences in DFS according to AL. Conclusion: In locally advanced rectal cancer, AL had an adverse effect on oncologic outcome in patients receiving aCTx without nCRT but not in patients receiving nCRT.

Gastrointestinal stromal tumours: Preoperative imaging features to predict recurrence after curative resection.

PURPOSE: To identify whether preoperative factors could predict the recurrence after curative resection of gastrointestinal stromal tumours (GISTs) and evaluate the performance of a prediction model using preoperative factors for GIST recurrence compared to a model using preoperative/postoperative factors. METHOD: This retrospective study included patients who underwent curative resection and preoperative CT for GIST. CT imaging features as preoperative factors were analysed by two abdominal radiologists. Modified National Institutes of Health scores were accessed as a postoperative factor. Multiple logistic regression analysis was performed to assess the preoperative and postoperative factors in predicting GIST recurrence. Through the logistic regression, two prediction models using preoperative factors only and both preoperative/postoperative factors were constructed, respectively. The internal validation of the prediction models was performed using bootstrapping sampling. RESULTS: Data in 113 patients were evaluated. Among them, 14 patients had recurrence. The multiple logistic regression analysis demonstrated that non-gastric location (odds ratio [OR] = 5.12, p = 0.029), ill-defined margin (OR = 4.93, p = 0.023), and prominent vessels around tumour (OR = 6.78, p = 0.007) were significant factors. The prediction models using these preoperative factors and adding a postoperative factor showed an area under the receiver operating characteristic curve of 0.863 and 0.897, respectively, which were not statistically different. The bootstrapping sampling showed the two models were valid. CONCLUSION: The prediction model derived from non-gastric location, ill-defined margin, and prominent vessels around tumour can be used preoperatively to estimate the risk of recurrence after resection of GIST.

Prognostic Impact of Carcinoembryonic Antigen Levels in Rectal Cancer Patients Who Had Received Neoadjuvant Chemoradiotherapy.

PURPOSE: Carcinoembryonic antigen (CEA) is a useful marker for rectal cancer. The aim of this study was to investigate the prognostic impact of CEA level according to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer patients who underwent radical surgery. METHODS: A total of 245 patients with rectal cancer who underwent radical surgery were retrospectively evaluated. Serum CEA level was measured preoperatively and postoperatively. We compared survival outcomes based on CEA level before and after surgery according to nCRT. RESULTS: Of the 245 patients, elevation of CEA level was observed preoperatively in 79 and postoperatively in 30, respectively. Eighty-seven (35.5%) patients received nCRT, and elevated CEA level was a significant prognostic factor both before and after surgery. In patients who had not received nCRT, an elevated CEA level was a significant prognostic factor before surgery but was not significant after surgery. In a multivariate analysis for prognostic factors, elevation of preoperative CEA level was an independent prognostic factor of disease-free survival (DFS) regardless of nCRT. Postoperative CEA level was an independent prognostic factor of DFS in patients who had received nCRT but was not a factor in patients who had not received nCRT. CONCLUSION: Serum CEA level was an independent prognostic factor both preoperatively and postoperatively in rectal cancer patients who had received nCRT.