Laparoscopically treated bowel obstruction secondary to a lesser omental hernia resulting from a previous laparoscopic total colectomy for ulcerative colitis: A report of two cases.

Lesser omental hernias are rare; however, they should be considered in symptomatic bowel obstruction subsequent to a subtotal or total colectomy. This report describes two cases of recurrent bowel obstruction secondary to lesser omental hernias after laparoscopic total colectomies for ulcerative colitis. Initially, these patients had been treated conservatively; however, due to symptom recurrence, surgical intervention was decided on. In both cases, laparoscopic surgery revealed lesser omental hernias. The small bowel, which had entered from the dorsal aspect of the stomach, was returned to the original position, and the lesser omentum was closed. The patients were discharged uneventfully, with no recurrent bowel obstruction during the follow-up period. These cases highlight the importance of including internal hernias in the differential diagnosis relative to recurrent bowel obstruction, in patient subpopulations with a prior history of a subtotal or total colectomy. Confirmation by computed tomography is preferable.

The usefulness of the endoscopic surgical skill qualification system in laparoscopic right hemicolectomy: a single-center, retrospective analysis with propensity score matching.

PURPOSE: Recently, a new certification system called the Endoscopic Surgical Skill Qualification System (ESSQS) has been launched in Japan to improve surgical safety. This study aimed to determine whether ESSQS-qualified surgeons affect the short- and long-term outcomes of laparoscopic right hemicolectomy. METHODS: A total of 187 colon cancer patients who underwent laparoscopic right hemicolectomy at Kindai University Hospital between January 2016 and December 2020 were enrolled. These patients were divided into two groups based on surgeries performed by ESSQS-qualified surgeons (QS group) and non-ESSQS-qualified surgeons (NQS group). The short- and long-term outcomes were compared between the two groups before and after propensity score matching (PSM). RESULTS: After PSM, 43 patients from each group were included in the matched cohort. In the short-term outcomes, the total operative time was significantly longer in the NQS group than in the QS group (229 vs. 174 min, p < 0.0001). However, there were no significant differences in the two groups regarding blood loss (0 vs. 0 ml, p = 0.7126), conversion (0.0% vs. 7.0%, p = 0.0779), Clavien-Dindo ≥ 2 complications (9.3% vs. 7.0%, p = 0.6933), mortality (2.3% vs. 0.0%, p = 0.3145), and postoperative hospital stay (9 vs. 9 days, p = 0.5357). In the long-term outcomes, there were no significant differences between the two groups in the 3-year overall survival (86.6% vs. 83.0%, p = 0.8361) and recurrence-free survival (61.7% vs. 72.0%, p = 0.3394). CONCLUSION: Laparoscopic right hemicolectomy performed by ESSQS-qualified surgeons contributed to shorter operative time. Under the supervision of ESSQS-qualified surgeons, almost equivalent safety and oncological outcomes are expected even in surgeries performed by non-ESSQS-qualified surgeons.

Mechanisms of primary and acquired resistance to immune checkpoint inhibitors in advanced non-small cell lung cancer: A multiplex immunohistochemistry-based single-cell analysis.

OBJECTIVE: Immune checkpoint inhibitors (ICIs) have become a key therapeutic modality for advanced non-small cell lung cancer (NSCLC), but most patients experience primary or acquired resistance to these drugs. We here explored the mechanisms underlying both types of ICI resistance by analysis of the tumor immune microenvironment (TME). MATERIALS AND METHODS: Four patients who experienced a long-term response to ICI treatment (progression-free survival [PFS] of ≥12 months) followed by disease progression, after which a rebiopsy was immediately performed (cohort-A), as well as four patients who experienced early tumor progression during ICI treatment (PFS of <9 weeks, cohort-B) were enrolled in this retrospective study. The pretreatment TME was evaluated by 16- or 17-color multiplex immunohistochemistry (mIHC)-based spatial profiling at the single-cell level for both cohorts. In cohort-A, changes in the TME after disease progression during ICI treatment were also investigated by mIHC analysis and transcriptomic analysis. RESULTS: Pretreatment tumor tissue from cohort-B manifested poor infiltration of tumor-reactive CD8+ T cells characterized by CD39 and CD103 expression or by programmed cell death-1 expression, implicating insufficient recognition of tumor cells by CD8+ T cells as a mechanism of primary ICI resistance. Analysis of the paired tumor specimens from cohort-A revealed various changes in the TME associated with acquired ICI resistance, including substantial infiltration of myeloid-derived suppressor cells and M2-type tumor-associated macrophages without a marked decline in the number of tumor-reactive CD8+ T cells; a decrease in the number of tumor-reactive CD8+ T cells; and an apparent decrease in neoantigen presentation by tumor cells. CONCLUSION: The presence of intratumoral tumor-reactive CD8+ T cells may be a prerequisite for a long-term response to ICI treatment in advanced NSCLC, but it is not sufficient for cancer cell eradication. Various TME profiles are associated with acquired ICI resistance, suggesting that patient-specific strategies to overcome such resistance may be necessary.

Contribution of MMP14-expressing cancer-associated fibroblasts in the tumor immune microenvironment to progression of colorectal cancer.

Matrix metalloproteinase 14 (MMP14) expression is implicated in progression of colorectal cancer, but its role in the tumor microenvironment (TME) has been unclear. The relevance of MMP14 to colorectal cancer progression was explored by analysis of transcriptomic data for colorectal adenocarcinoma patients (n = 592) in The Cancer Genome Atlas. The role of MMP14 in the TME was investigated in a retrospective analysis of tumor samples from 86 individuals with stage III colorectal cancer by single cell-based spatial profiling of MMP14 expression as performed by 12-color multiplex immunohistochemistry (mIHC). Analysis of gene expression data revealed that high MMP14 expression was associated with tumor progression and implicated both cancer-associated fibroblasts (CAFs) and tumor-associated macrophages in such progression. Spatial profiling by mIHC revealed that a higher percentage of MMP14+ cells among intratumoral CAFs (MMP14+ CAF/CAF ratio) was associated with poorer relapse-free survival. Multivariable analysis including key clinical factors identified the MMP14+ CAF/CAF ratio as an independent poor prognostic factor. Moreover, the patient subset with both a high MMP14+ CAF/CAF ratio and a low tumor-infiltrating lymphocyte density showed the worst prognosis. Our results suggest that MMP14+ CAFs play an important role in progression of stage III colorectal cancer and may therefore be a promising therapeutic target.

Performance of Idylla™ RAS-BRAF mutation test for formalin-fixed paraffin-embedded tissues of colorectal cancer.

BACKGROUND: The Biocartis Idylla™ platform is a fully automated, real-time PCR-based diagnostic system. The Idylla™ KRAS and NRAS-BRAF Mutation Tests have been developed for the qualitative detection of mutations in KRAS, NRAS and BRAF genes, facilitating the genomic profiling of patients with colorectal cancer. The aim of the present study was to evaluate clinical performances of these tests in Japan. METHODS: The RAS and BRAF mutation statuses of 253 formalin-fixed paraffin-embedded (FFPE) colorectal cancer tissues were analyzed using the Investigational Use Only Idylla™ KRAS Mutation Test and the Idylla™ NRAS-BRAF Mutation Test and an in vitro diagnostics (IVD) kit (MEBGEN RASKET™-B kit). RESULTS: The success rate for obtaining a valid mutational data without retest of the Idylla tests was 97.6% (247/253): 111 KRAS mutations (43.8%), 9 NRAS mutations (3.6%), and 36 BRAF V600E mutations (14.2%) were detected using the Idylla tests. Compared with the MEBGEN RASKET-B results, the positive concordance rate was 97.4%, the negative concordance rate was 95.7%, and the overall concordance rate was 95.3% (κ = 0.919, 95% CI 0.871-0.967). The average turnaround time to Idylla™ KRAS and NRAS-BRAF Mutation Test was 5.6 working days (range: 3-11 days). CONCLUSION: This result demonstrates a high concordance between the Idylla™ KRAS and NRAS-BRAF Mutation Tests and an existing IVD kit. In this manner, the Idylla™ mutation tests were validated for the detection of clinically significant KRAS, NRAS, and BRAF mutations in FFPE samples from colorectal cancer patients.

Effectiveness of negative pressure wound therapy with instillation and dwelling after stoma closure: a retrospective and propensity score matching analysis.

The use of temporary diverting stoma has become more common in low colorectal anastomosis to reduce anastomotic complications. Surgical site infection (SSI) at the stoma closure site has been one of the most frequent postoperative complications. The aim of this study was to compare the short-term outcomes between conventional primary suture closure and negative pressure wound therapy with instillation and dwelling (NPWTi-d) therapy following purse-string suturing, using propensity score matching analysis. We retrospectively evaluated the medical records of 107 patients who underwent stoma closure between January 2016 and October 2020. The primary outcome was the proportion of SSI. The secondary outcome was the day of postoperative length of stay. Propensity score matching with one-to-one match was performed for reducing treatment selection bias. Of a total of 107 patients, 67 patients had been treated with conventional primary closure and 40 with NPWTi-d therapy. The propensity score matching derived 37 pairs. The respective SSI proportions were 0% and 16.2% in the groups with NPWTi-d and primary closure (P = 0.025). The respective median days of postoperative hospital stay were 9.0 and 10.0 in the groups with NPWTi-d and primary closure (P = 0.453). NPWTi-d therapy with purse-string suturing was effective in reducing SSI after stoma closure.

Laparoscopic complete mesocolic excision with central vascular ligation for splenic flexure colon cancer: short- and long-term outcomes.

BACKGROUND: Complete mesocolic excision (CME) with central vascular ligation (CVL) for colon cancer is an essential procedure for improved oncologic outcomes after surgery. Laparoscopic surgery for splenic flexure colon cancer was recently adopted due to a greater understanding of surgical anatomy and improvements in surgical techniques and innovative surgical devices. METHODS: We retrospectively analyzed the data of patients with splenic flexure colon cancer who underwent laparoscopic CME with CVL at our institution between January 2005 and December 2017. RESULTS: Forty-five patients (4.8%) were enrolled in this study. Laparoscopic CME with CVL was successfully performed in all patients. The median operative time was 178 min, and the median estimated blood loss was 20 g. Perioperative complications developed in 6 patients (13.3%). The median postoperative hospital stay was 9 days. According to the pathological report, the median number of harvested lymph nodes was 15, and lymph node metastasis developed in 14 patients (31.1%). No metastasis was observed at the root of the middle colic artery or the inferior mesenteric artery. The median follow-up period was 49 months. The cumulative 5-year overall survival and disease-free survival rates were 85.9% and 84.7%, respectively. The cancer-specific survival rate in stage I-III patients was 92.7%. Recurrence was observed in 5 patients (11.1%), including three patients with peritoneal dissemination and two patients with distant metastasis. CONCLUSIONS: Laparoscopic CME with CVL for splenic flexure colon cancer appears to be oncologically safe and feasible based on the short- and long-term outcomes in our study. However, it is careful to introduce this procedure to necessitate the anatomical understandings and surgeon's skill. The appropriate indications must be established with more case registries because our experience is limited.

The technique for less infectious and earlier healing of stoma closure wound: negative pressure wound therapy with instillation and dwelling followed by primary closure.

BACKGROUND: Temporary stomas have been widely used to avoid the risk of complications such as anastomotic leakage after colorectal resection. Stoma closure is relatively easy; however, postoperative surgical site infection (SSI) may be a problem. Various methods have been used to reduce the incidence of SSI. We aimed to evaluate a new technique for stoma wound closure. METHODS: We enrolled patients who underwent stoma closure at our hospital between September 2019 and May 2020. We selected patients who lived far from our hospital and had difficulty visiting the hospital regularly and who agreed to undergo this surgical technique. We used negative pressure wound therapy with instillation and dwelling (NPWTi-d) and delayed primary closure for these patients. RESULTS: Four patients underwent NPWTi-d and delayed primary closure without the occurrence of SSI. The median postoperative hospital stay was 9 days (range: 7-14 days), and the median number of days to confirmation of epithelialization was 11.5 days (range: 10-16 days). CONCLUSION: The combined use of NPWTi-d and delayed primary closure for the stoma wound was very effective. This method may be a valuable new technique for wound management after stoma closure.

[A Case of Unresectable Gallbladder Cancer with Relatively Good Prognosis Treated with Upfront Surgery Followed by Systemic Chemotherapy].

A female patient in her 60s was diagnosed with advanced gallbladder cancer invading the hilar plate. Exploratory laparoscopic examination showed limited peritoneal dissemination. Despite endoscopic nasobiliary drainage, it was difficult to treat infectious cholangitis. To initiate chemotherapy, it was imperative to control the infection; hence, we chose to perform extended right hepatectomy, extrahepatic bile duct resection, lymph node dissection, and cholangiojejunostomy. We have been able to continue systemic chemotherapy for more than 2 years after surgery, and the patient did not experience infectious cholangitis. She has survived for almost 2 years and 8 months post-diagnosis.

The safety of omitting prophylactic abdominal drainage after laparoscopic liver resection: Retrospective analysis of 100 consecutive cases.

INTRODUCTION: Whether prophylactic abdominal drainage after laparoscopic liver resection (LLR) is necessary remains unclear. This study aimed to evaluate the safety of omitting prophylactic abdominal drainage after LLR. METHODS: A retrospective analysis of 100 consecutive patients who underwent LLR at Osaka Rosai Hospital from April 2011 to November 2018 was performed. During this period, prophylactic abdominal drainage was routinely omitted during LLR without biliary anastomosis. The primary endpoint was the frequency of additional abdominal drainage. The secondary endpoint was the rate of postoperative complications. RESULTS: Ninety-six patients (96%) underwent partial resection or lateral segmentectomy, and 89 patients (89%) were Child-Pugh grade A. The median operative time was 102 (range, 31-274) minutes. The median blood loss was minimal (range, 0-280 ml), and blood transfusion was performed for one patient (1%). One case (1%) was converted to open surgery. Additional abdominal drainage was required for one patient (1%) with an intraabdominal abscess. Postoperative complications were seen in 5 patients (5%). High-grade complications (≥grade III according to the Clavien-Dindo classification) were seen in two patients (2%). There were no cases of reoperation or perioperative death. The median postoperative hospital stay was 8 (range, 4-65) days. CONCLUSIONS: Prophylactic abdominal drainage could be safely omitted for selected patients and operative procedures.

[A Case of Conversion Surgery Following Combined Chemotherapy with Molecular Targeting Agent for Unresectable Colorectal Liver Metastases].

A 76-year-old woman complaining of constipation was diagnosed with advanced rectosigmoid colon cancer with unresectable liver metastases. We performed a laparoscopic high-anterior resection due to the obstruction. The patient then received a capecitabine plus oxaliplatin(CapeOX)plus cetuximab(Cmab)combination chemotherapy. After 7 cycles of CapeOX with Cmab, the multiple liver metastases had reduced remarkably in size. Therefore, a liver metastases resection was performed. The patient underwent 6 cycles of postoperative CapeOX with Cmab therapy and has survived 7 years with no recurrence after the primary surgery.

[A Case of Rectal Cancer with Multiple Liver Metastases Curatively Resected after Systemic Chemotherapy].

A 61-year-old man complainingof bloody stool was diagnosed with advanced rectal cancer with multiple liver metastases (cT3[A]N1M1a[H2], cStage Ⅳ). We introduced bevacizumab combined systemic chemotherapy prior to radical surgery and confirmed tumor shrinkage in both the primary tumor and liver metastases following systemic chemotherapy. We performed laparoscopic lower-anterior resection, and then the patient underwent liver metastases resection. The histologic evaluation was Grade 2. This was a pathologically curative resection, and the patient has been disease-free since the last operation.

[A Case of Conversion Surgery for a Patient with Initially Unresectable Pancreatic Cancer with a Pathological Complete Response to S-1 Chemotherapy].

We present a case ofa 67-year-old woman with Stage IV pancreatic head cancer with invasion to the superior mesenteric vein and artery, and distant lymph node metastases. The patient received S-1 mono-chemotherapy. After 2 courses of chemotherapy, the tumor marker was decreased to the normal levels, and the tumor size was dramatically reduced with undetectable lymph node metastases on CT. As the disease status was maintained following chemotherapy, the patient underwent subtotal stomach preserving pancreaticoduodenectomy, 8 months after initiation of the chemotherapy. Histopathologically, no cancer cells were found in the main tumor and dissected lymph nodes. Final diagnosis was made with pathological complete response. The patient was alive without recurrence for 10 months after surgery.

[Resection of the Distal Part of the Gastric Tube for the Gastric Tube Cancer after Esophagectomy - A Case Report].

A 76-year-old man was admitted to our hospital for treatment of gastric tube cancer(cT2N0M0, cStage II A)detected by a screening upper gastrointestinal endoscopy. Seven years previously, he had undergone subtotal esophagectomy for esophageal cancer with gastric pull-up via the retrosternal route. At that time, he experienced cardiopulmonary arrest due to ventric- ular tachycardia. He was in a state of poor nutrition(BMI 15 kg/m2). Therefore, reducing operative stress as much as possible, minimizing complications after surgery, and aiming for a satisfactory postoperative course are all important goals. Based on his past history, we performed distal gastrectomy(resection of the distal part of the gastric tube)without excision of the right gastroepiploic artery. The postoperative course was uneventful. He was discharged 40 days after surgery. By considering the risks of surgery due to cardiac dysfunction and malnutrition, we were able to provide effective and safe therapy for the patient.