Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients.

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Short-term and three-year long-term outcomes of laparoscopic surgery versus open surgery for obstructive colorectal cancer following self-expandable metallic stent placement: a meta-analysis.

BACKGROUND: A bridge to surgery (BTS) after self-expandable metallic stent (SEMS) placement is a widely recognized treatment strategy for obstructive colorectal cancer. However, there is still a lack of evidence for the efficacy and safety of laparoscopic surgery following SEMS placement. The aim of this systematic review and meta-analysis was to compare the short-term and long-term outcomes of laparoscopic surgery with those of open surgery following SEMS placement in patients with obstructive colorectal cancer. METHODS: An electronic literature search through to December 2022 was performed to identify studies comparing short-term and long-term outcomes between laparoscopic and open surgery following SEMS placement for obstructive colorectal cancer. The main outcome measures were postoperative complication rates and mortality. Secondary outcome measures were the 3-year recurrence-free survival (RFS) and 3-year overall survival (OS) rates. The meta-analysis was performed using fixed-effect or random-effects methods to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: The meta-analysis included 15 studies and 883 patients, of whom 467 (52.9%) underwent laparoscopic surgery and 416 (47.1%) underwent open surgery following SEMS placement. The postoperative complication rate was significantly lower in the laparoscopic surgery group than in the open surgery group (OR 0.47, 95% CI 0.32-0.67, P < 0.001). There was no significant difference in the 3-year RFS rate or 3-year OS rate between the laparoscopic and open surgery groups (3-year RFS, OR 0.78, 95% CI 0.50-1.24, P = 0.30; 3-year OS, OR 0.68, 95% CI 0.41-1.12, P = 0.13). CONCLUSION: This meta-analysis found that the short-term outcome was better in patients who underwent laparoscopic surgery following SEMS placement than in those who underwent open surgery. Furthermore, there was no significant difference in long-term outcomes between the two groups. Laparoscopic surgery following SEMS placement may be a safe and effective treatment option for obstructive colorectal cancer.

The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis.

PURPOSE: Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure. METHODS: Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure. RESULTS: Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure. CONCLUSIONS: Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer.

PURPOSE: Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking. METHODS: We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days. RESULTS: In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72). CONCLUSIONS: A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Postoperative infectious complications have a negative oncological impact in patients after stent placement with malignant large bowel obstruction.

PURPOSE: In this study, we aimed to investigate the oncological impact of postoperative infection in patients with malignant large bowel obstruction managed by self-expandable metallic stent placement as a bridge to surgery. METHODS: The cohort of this multicenter retrospective study comprised 129 patients with pathological stage II/III malignant large bowel obstruction who had undergone bridge to surgery. Patients were allocated to no-postoperative infection (n = 116) and postoperative infection groups (n = 13). RESULTS: The postoperative infection group had a significantly greater proportion of men, fewer harvested lymph nodes, and longer postoperative hospital stays than did the no-postoperative infection group. Self-expandable metallic stent-related variables, including clinical failure, were not associated with postoperative infection. Male sex and low body mass index were identified as risk factors for postoperative infection by multivariate logistic regression. Three-year relapse-free survival rates were 75.5% and 30.8% in the no-postoperative infection and postoperative infection groups, respectively; this difference is statistically significant. Male sex, postoperative infection, and T4 were identified as independent prognostic factors by multivariate Cox proportional hazard analysis. The postoperative infection group had a significantly higher total recurrence rate and shorter interval to recurrence than did the no-postoperative infection group. CONCLUSION: To the best of our knowledge, this is the first study to show that postoperative infection in bridge to surgery patients has a negative oncological impact. This finding indicates that further improvement in perioperative management of bridge to surgery patients is required to minimize postoperative infection and that patient-risk stratification and additional therapy would contribute to improving oncological outcomes.

The T-CEA score: a useful prognostic indicator based on postoperative CEA and pathological T4 levels for patients with stage II-III colorectal cancer.

PURPOSE: To investigate a prognostic score for stage II-III colorectal cancer (CRC) based on post-CEA and pT4 levels. METHODS: Two cohorts of stage II-III CRC patients who underwent curative surgery between 2011 and 2017 were included. The prognostic score (T-CEA score) was calculated as follows: T-CEA-0, post-CEA ≤ 5 ng/mL and pT1-3; T-CEA-1, post-CEA > 5 ng/mL or pT4; T-CEA-2, post-CEA > 5 ng/mL and pT4. RESULTS: The T-CEA scores of the 587 patients were as follows: T-CEA-0 (n = 436; 74%), T-CEA-1 (n = 129; 22%), and T-CEA-2 (n = 10; 2%). The 5-year recurrence-free survival (RFS) rates of the T-CEA-0, 1, and 2 groups were 80.3%, 54.8%, and 0%, respectively (P < 0.01), and the 5-year overall survival (OS) rates were 90.9%, 74.2%, and 0%, respectively (T-CEA-0 vs T-CEA-1: P < 0.01, T-CEA-1 vs T-CEA-2: P = 0.04). Multivariate analysis revealed that an elevated T-CEA score of 1 or 2 was a significant risk factor for poor RFS (HR: 2.89, P < 0.01) and OS (HR: 2.85, P < 0.01). CONCLUSION: The T-CEA score is a reliable and convenient prognostic score for stage II-III CRC.

Colonic stent as a bridge to surgery versus emergency resection for right-sided malignant large bowel obstruction: a meta-analysis.

BACKGROUND: Preoperative colonic stenting for malignant large bowel obstruction (MLBO), also called bridge to surgery (BTS), is considered a great substitute treatment for emergency resection (ER) in the left-sided colon. However, its efficacy in the right-sided colon remains controversial. This systematic review and meta-analysis aimed to compare the postoperative short-term outcomes between BTS and ER for right-sided MLBO. METHODS: A comprehensive electronic literature search throughout December 2020 was performed to identify studies comparing short-term outcomes between BTS and ER for right-side MLBO. The main outcome measures were postoperative complications and mortality rates. A meta-analysis was performed using a fixed-effect or a random-effect method to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: Seven studies were included in this meta-analysis, comprising 5136 patients, of whom 1662 (32.4%) underwent BTS and 3474 (67.6%) underwent ER. This meta-analysis demonstrated that BTS resulted in reductions in postoperative complications (OR = 0.78; 95% CI: 0.66-0.92) and mortality (OR = 0.51; 95% CI: 0.28-0.92) than ER. CONCLUSION: The results of this meta-analysis indicate that BTS for right-sided MLBO confers preferable short-term outcomes as well as for left-sided. This suggests that BTS results in a reduction of postoperative complications and mortality for right-sided MLBO than ER.

[Long-Term Response to UFT/UZEL/Bevacizumab Therapy for Lung Metastasis after Surgery for Early-Stage Colon Cancer in a Late-Stage Elderly Patient].

Late-stage elderly patients have low tolerance to chemotherapy, and they have difficulties when they are treated with standard chemotherapy. We report a case of a late-stage elderly patient who had a long-term response to UFT/UZEL/bevacizumab( Bev)therapy for lung metastasis after surgery for early-stage colon cancer. He was 82-years-old and underwent laparoscopy-assisted sigmoid colectomy for sigmoid colon cancer at another hospital. The pathological diagnosis was pT1b, ly1, v0, N0, M0, pStage Ⅰ. Six months after the surgery, a small nodule was noted in the middle lobe of the right lung. It grew five months later and was definitely diagnosed as lung metastasis. Considering his physical condition and tumor size, we opted to introduce less invasive chemotherapy instead of standard chemotherapy. UFT/UZEL/Bev was started 14 months after surgery. Although he required dose reduction due to anorexia, he safely continued the treatment with partial response (PR), which was maintained for 2 years and 6 months. While UFT/UZEL/Bev has no convincing evidence, it may be an option for vulnerable patients, especially those with non-life-threatening disease.

The impact of molecular profile on the lymphatic spread pattern in stage III colon cancer.

The anatomical spread of lymph node (LN) metastasis is of practical importance in the surgical management of colon cancer (CC). We examined the effect of KRAS, BRAF, and microsatellite instability (MSI) on LN count and anatomical spread pattern in stage III CC. We determined KRAS, BRAF, and MSI status from stage III CC patients. Biomarker status was correlated with LN count and anatomical spread pattern, which was classified as sequential or skipped. Relapse-free survival (RFS) was estimated using Kaplan-Meier method, and correlations were assessed using log-rank and Cox regression analyses. We analyzed 369 stage III CC patients. The proportion of KRAS mutant (mt), BRAF mt, and MSI-high (H) were 44.2% (163/344), 6.8% (25/344), and 6.8% (25/344), respectively. The mean number of metastatic LN was higher in microsatellite-stable (MSS) compared with MSI patients (3.5 vs. 2.7, P = .0406), although no differences were observed in accordance with KRAS or BRAF status. Interestingly, patients with BRAF mt and MSI-H were less likely to harbor skipped metastatic LN (9.3% vs 20% and 4% vs 10.5% compared with BRAF wild-type (wt) and MSS, respectively), but KRAS status did not predict anatomical spread pattern. Patients with KRAS wt and MSI-H showed superior RFS compared with KRAS mt and MSS patients, respectively, whereas BRAF status did not affect RFS. Differences exist in the anatomical pattern of invaded LN in accordance with the molecular status of stage III CC. Patients with MSI-H CC have less invaded and skipped LN, suggesting that a tailored surgical approach is possible.

Emerging RAS, BRAF, and EGFR mutations in cell-free DNA of metastatic colorectal patients are associated with both primary and secondary resistance to first-line anti-EGFR therapy.

Oncogenic RAS mutations are negative biomarkers of response to epidermal growth factor receptor (EGFR) blockade. RAS mutations are usually detected in biopsies of primary colorectal tumors. However, the genomic profiles of primary tumors and metastases are not always concordant, and chemotherapeutic agents can alter the tumor molecular landscape. Cell-free DNA (cfDNA) is a novel tool to detect molecular heterogeneity. This study evaluated the clinical utility of cfDNA to predict primary or secondary resistance to EGFR blockade in patients with metastatic colorectal cancer. Thirty metastatic colorectal cancer patients without RAS and BRAF mutations were prospectively enrolled and treated with cytotoxic agents and EGFR blockade as first-line therapy. cfDNA was analyzed for the presence of RAS, BRAF, and EGFR (S492R) point mutations before initiating chemotherapy and every 2 months during chemotherapy. The analysis was performed in 223 plasma samples from all 30 patients. Of the 30 patients, five had RAS mutations in their cfDNA before starting chemotherapy and did not respond. Twenty-four of the remaining 25 patients without cfDNA RAS mutations had a response. Twenty of the 24 responders developed secondary resistance and cfDNA RAS mutations were found in 17 of the 20. cfDNA BRAF mutations were found in seven, and EGFR mutations were found in eight of the 20 patients. Emerging RAS, BRAF, and EGFR mutations occurred in patients with primary and secondary resistance to EGFR blockade. The detection of these mutations in cfDNA is a promising approach to predict treatment response and secondary resistance.

[A Case of Peritoneal Dissemination of Colorectal Cancer in Which Conversion Surgery Could Be Performed after Reduction with CAPOX/Bevacizumab].

A woman in her 60s underwent lower endoscopy due to a positive fecal occult blood test. A type 2 tumor was found in the cecum, and a biopsy resulted in the diagnosis of adenocarcinoma(tub2). Contrast-enhanced CT showed an enlarged paracolonic lymph node but no distant metastasis, so the patient underwent a laparoscopic-assisted ileocolic resection and D3 lymph node dissection for cecum cancer. The pathology was pT3, pN2b, pM0, pStage Ⅲc, and 12 courses of FOLFOX were administered as adjuvant chemotherapy. Twenty-four months after the completion of adjuvant chemotherapy, an elevated CEA was observed, and a PET-CT was performed, which showed multiple peritoneal disseminated nodules with FDG accumulation. Based on this finding, CAPOX/bevacizumab therapy was introduced, and on completion of 4 courses, the PET-CT showed a decrease in the size of the nodules and the disappearance of FDG accumulation. Based on this, the patient underwent resection. A peritoneal dissemination resection and bilateral ovariectomy were laparoscopically performed, and the patient is currently under observation. In patients with metastatic recurrence of peritoneal dissemination who underwent complete resection, treatment with CAPOX/bevacizumab may allow for disease control and provide a long-term prognosis.

Analysis of colorectal cancer-related mutations by liquid biopsy: Utility of circulating cell-free DNA and circulating tumor cells.

We recruited 56 colorectal cancer patients and compared the mutational spectrum of tumor tissue DNA, circulating cell-free DNA (ccfDNA) and circulating tumor cell (CTC) DNA (ctcDNA) to evaluate the potential of liquid biopsy to detect heterogeneity of cancer. Tumor tissue DNA, ccfDNA, and ctcDNA were extracted from each patient and analyzed using next-generation sequencing (NGS) and digital PCR. To maximize yields of CTC, three antibodies were used in the capture process. From 34 untreated patients, 53 mutations were detected in tumor tissue DNA using NGS. Forty-seven mutations were detected in ccfDNA, including 20 not detected in tissues. Sixteen mutations were detected in ctcDNA, including five not detected in tissues. In 12 patients (35.3%), mutations not found in tumor tissues were detected by liquid biopsy: nine (26.5%) in ccfDNA only and three (8.8%) in ctcDNA only. Combination analysis of the two liquid biopsy samples increased the sensitivity to detect heterogeneity. From 22 stage IV patients with RAS mutations in their primary tumors, RAS mutations were detected in 14 (63.6%) ccfDNA and in eight (36.4%) ctcDNA using digital PCR. Mutations not detected in primary tumors can be identified in ccfDNA and in ctcDNA, indicating the potential of liquid biopsy in complementing gene analysis. Combination analysis improves sensitivity. Sensitivity to detect cancer-specific mutations is higher in ccfDNA compared with ctcDNA.

Establishment and characterization of a novel neuroendocrine carcinoma cell line derived from a human ascending colon tumor.

The incidence of rare neuroendocrine tumors (NET) is rapidly increasing. Neuroendocrine carcinoma (NEC) is a NET with poorly differentiated histological features, high proliferative properties and associated poor prognoses. As these carcinomas are so rare and, thus, affect only a small number of patients allowing for few cell lines to be derived from patient biopsies, the histological, immunohistochemical, and clinical characteristics associated with colorectal NEC and NEC in other organs have yet to be clearly defined. Herein, we describe the establishment of a novel NEC cell line (SS-2) derived from a tumor resection of the ascending colon from a 59-year-old Japanese woman. The histological, electron microscopic and immunohistochemical features of chromogranin A (CgA) as well as confirmation of synaptophysin positivity in this tumor were typical of those commonly observed in surgically resected colorectal NEC. Further, the Ki-67 labeling index of the resected tumor was >20% and, thus, the tumor was diagnosed as an NEC of the ascending colon. The SS-2 cell line maintained characteristic features to those of the resected tumor, which were further retained following implantation into subcutaneous tissues of nude mice. Additionally, when SS-2 cells were seeded into ultra-low attachment plates, they formed spheres that expressed higher levels of the cancer stem cell (CSC) marker CD133 compared to SS-2 cells cultured under adherent conditions. SS-2 cells may, therefore, contribute to the current knowledge on midgut NEC biological function while providing a novel platform for examining the effects of colorectal NEC drugs, including CSC.

[Consideration for Prognostic Indicators of Ovarian Metastasis of Colorectal Cancer].

Ovarian metastasis of colorectal cancer is associated with poor prognosis. Recent advances in chemotherapy may improve this prognosis. In this retrospective study, we evaluated indicators of poor prognosis for ovarian metastasis of colorectal cancer. Twenty patients, who were diagnosed with ovarian metastasis of colorectal cancer from April 2000 to December 2017, were enrolled. Oophorectomy was performed in 18 of the 20 patients. Postoperative chemotherapy was provided to 13 patients, and molecular targeting agents were administered in 5 patients. Metastases to other organs besides the ovaries, premenopausal condition, undifferentiated histologic type of the primary tumor, and no resection of ovarian metastases were identified as indicators of poor prognosis. The 3-year survival rate was 15%, and the 5-year survival rate was 0%. In conclusion, oophorectomy can improve the prognosis of patients with ovarian metastasis of colorectal cancer. However, prognostic improvement due to molecular target agents was not shown.

Relationship Between Immunophenotypes, Genetic Profiles, and Clinicopathologic Characteristics in Small Bowel Adenocarcinoma.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.

Lymphatic spread patterns in young versus elderly patients with stage III colon cancer.

BACKGROUND: The anatomical pattern of lymph nodes spread differs between young (aged 45 years or younger) and elderly (aged 80 years or older) patients with stage III colon cancer and is poorly investigated. METHODS: Two groups of patients (young and elderly) with stage III colon cancer who underwent upfront extensive (D3) lymphadenectomy at eight Japanese centres between 1998 and 2018 were retrospectively analysed. The primary endpoint was the proportion of positive central lymph nodes. The lymph nodes spreading pattern and its prognostic impact on recurrence-free survival and overall survival in the two groups were also compared. RESULTS: Two hundred and ten young patients and 348 elderly patients were identified and compared. The total number of lymph nodes harvested and the total number of invaded lymph nodes were significantly higher in younger patients compared with elderly patients (median of 31.5 (3-151) versus 21 (3-116), P < 0.001 and median of 3 (1-21) versus 2 (1-25), P < 0.001 respectively). The proportion of positive central lymph nodes were higher in younger patients than in elderly patients (9.52% (95% c.i. 6.24 to 14.2%) versus 4.59% (95% c.i. 2.84 to 7.31%), P = 0.012). In multivariate models for recurrence-free survival, central lymph nodes invasion were identified as a poor prognostic factor in younger patients (HR 5.21 (95% c.i. 1.76 to 15.39)) but not in elderly patients (HR 1.73 (95% c.i. 0.80 to 3.76)). CONCLUSION: Young patients with stage III colon cancer have a higher risk of central lymph nodes invasion, suggesting a more aggressive disease biology. The presence of central lymph nodes invasion are associated with a worse outcome in young patients.

Surgical Site Infections in Gastroenterological Surgery.

Surgical site infections (SSIs) remain one of the most common serious surgical complications and are the second most frequent healthcare-associated infection. Patients with SSIs have a significantly increased postoperative length of hospital stay, hospital expenses, and mortality risk compared with patients without SSIs. The prevention of SSI requires the integration of a range of perioperative measures, and approximately 50% of SSIs are preventable through the implementation of evidence-based preventative strategies. Several international guidelines for SSI prevention are currently available worldwide. However, there is an urgent need for SSI prevention guidelines specific to Japan because of the differences in the healthcare systems of Japan versus western countries. In 2018, the Japan Society for Surgical Infection published SSI prevention guidelines for gastroenterological surgery. Although evidence-based SSI prevention guidelines are now available, it is important to consider the appropriateness of these guidelines depending on the actual conditions in each facility. A systemic inflammatory host response is a hallmark of bacterial infection, including SSI. Therefore, blood inflammatory markers are potentially useful in SSI diagnosis, outcome prediction, and termination of therapeutic intervention. In this review, we describe the current guideline-based perioperative management strategies for SSI prevention, focusing on gastroenterological surgery and the supplemental utility of blood inflammatory markers.

Useful Preoperative Simulation of Laparoscopic Surgery for Rectal Cancer in Patients with Kyphosis.

Kyphosis complicates abdominal surgery. Here, we report a case of rectal cancer in a patient with kyphosis who underwent successful laparoscopic surgery after a preoperative simulation. An 81-year-old woman with rectal cancer was admitted to our department, and laparoscopic surgery was planned. Physical examination revealed severe kyphosis. To ensure successful laparoscopic surgery, we conducted a detailed preoperative simulation, including three-dimensional CT simulations of port arrangement and anatomy, simulation of body position, selection of surgical instruments, and preoperative discussion with the anesthesiologist. We planned to insert the first port in the umbilical region for pneumoperitoneum and the camera port in the ventral region under pneumoperitoneum. We planned to insert the ports on the right side of the patient's body from the caudal regions, after considering the location of the inferior mesenteric artery and the limitations in degrees and space attributable to the costal arch and promontorium. Beach chair position was planned. We used a fan-shaped retractor and sponge retractor to remove the small intestine from the surgical view. In preoperative discussions with the anesthesiologist, we decided to maintain pneumoperitoneum pressure at less than 8 mm Hg during the operation, to safeguard respiratory function. Lower anterior resection with D2 lymph node dissection was performed, without intraoperative complications. At 2 years postoperatively, the patient was healthy with no signs of recurrence. Laparoscopic surgery appears to be a suitable choice for patients with kyphosis. We believe that preoperative simulation will result in successful outcomes.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report.

BACKGROUND: A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF. CASE PRESENTATION: A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge. CONCLUSIONS: A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

A Case of a Fixed Giant Peritoneal Loose Body outside the Peritoneum and near the Rectovesical Excavation.

A peritoneal loose body (PLB) is tissue completely separated from other intraperitoneal organs. It is rare and usually found incidentally during laparotomy, examination, or autopsy. PLBs are usually located free in the peritoneal cavity and not in the extraperitoneal space. They are thought to originate when epiploic appendices are released into the abdominal cavity after ischemic necrosis. We report a case of a giant PLB outside the peritoneal cavity, adjacent to the rectovesical excavation, that was identified preoperatively inan asymptomatic 83-year-old man undergoing evaluation for cholecystolithiasis. Computed tomography revealed a mass with well-defined margins in the rectovesical excavation. The mass (diameter, 60 mm) consisted of a calcified core and peripheral soft tissue and did not appear to invade adjacent organs. Although there were no symptoms or tumor growth over time, we scheduled a laparoscopic extraction for definitive diagnosis. On laparoscopic exploration, a white ovoid mass was found in the rectovesical excavation; there was no invasion of adjacent organs. We diagnosed a giant PLB. Postoperative recovery was uneventful. Most PLBs are asymptomatic and do not require surgery, except when symptoms are present, when the PLB is large, or when malignancy is suspected. PLB is rarely extraperitoneal and is usually freely mobile; however, in our patient, it was fixed and outside the abdominal cavity, near the rectovesical fossa. Although it could not be diagnosed preoperatively as being extraperitoneal, imaging findings were typical of PLB; thus, it was possible to remove the mass laparoscopically without bowel resection.