Suctionable Gauze Ball Operated by the Console Surgeon Overcomes Wet Scenes during Robotic Rectal Surgery.

Although robotic rectal resections are now widely performed, there are few robotic suction tools that can be easily used by console surgeons. It can therefore be difficult to maintain a clear visual field in the pelvis when there is effusion and bleeding from either a highly advanced cancer or from preoperative cancer treatment. In this report, we introduce our unique surgical technique that uses a soft catheter with a small gauze ball attached, inserted through the assistant port. This simple and inexpensive "instrument" can be used by the console surgeon as a retractor as well as a reliable suction device to secure their view of the operative field in the pelvis. This technique can be used in a narrow surgical field and does not rely on an assistant surgeon, making it potentially applicable to all types of surgery.

Robotic distal gastrectomy plus spleen-preserving distal pancreatectomy: optimal resection for simultaneous gastric cancer and intraductal papillary mucinous neoplasm of the pancreatic body.

BACKGROUND: Organ-preserving surgery has recently gained increasing attention. However, performing the surgery for duplicated gastric and distal pancreatic tumors is difficult because of procedural complexity and concerns of remnant gastric necrosis. We present the first case of simultaneous robotic distal gastrectomy plus spleen-preserving distal pancreatectomy in a patient with overlapping gastric cancer and intraductal papillary mucinous neoplasm. CASE PRESENTATION: A 78-year-old man was diagnosed with gastric cancer in the middle stomach and intraductal papillary mucinous neoplasm of the pancreatic body. Radical cure surgery was performed using the da Vinci Xi robotic system. Conventional distal gastrectomy was initially completed using near-infrared ray guidance when transecting the stomach. After dividing the pancreas, the parenchyma of the distal pancreas was detached from the splenic artery and vein; multiple branches from these splenic vessels were dissected. Indocyanine green imaging confirmed sufficient blood flow in the splenic vessels and perfusion of the remnant stomach. Ultimately, gastrointestinal reconstruction was performed, and the postoperative course was uneventful. CONCLUSIONS: The robotic distal gastrectomy plus spleen-preserving distal pancreatectomy procedure was safely performed. Compared to the total gastrectomy plus distal pancreatectomy with splenectomy procedure, this technique may improve the quality of dietary life, reduce weight loss, and prevent complications associated with splenectomy.

[A Case of Transverse Colon Cancer with Gastrointestinal Amyloidosis Prevented from Anastomotic Leakage by Multidimensional Approach].

The patient was a 68-year-old woman who was on hemodialysis due to systemic amyloidosis and nephrotic syndrome. Biopsy revealed amyloid deposition in the stomach, duodenum, and colon. A transverse colon tumor was found on a follow- up CT after the aortic dissection surgery. We performed lower gastrointestinal endoscopy and contrast-enhanced CT and diagnosed transverse colon cancer with gastric wall infiltration(cStage Ⅲc). We considered that transverse colon resection was oncologically sufficient. However, due to concurrent gastrointestinal amyloidosis, which increased the risk of anastomotic leakage we performed laparoscopic extended right hemicolectomy to avoid colon-colon anastomosis with partial gastrectomy. Additionally intraoperative indocyanine green(ICG)fluorescence imaging showed that the fluorescence signal in the small intestinal wall was satisfactory, while it was weak in the colon wall. As a result, we suspected of impaired blood flow of colon wall due to an amyloidosis, so we additionally created a loop ileostomy. It is said that gastrointestinal amyloidosis raises the risk of anastomotic leakage. A case of transverse colon cancer complicated by gastrointestinal amyloidosis in which we successfully prevented anastomotic leakage through a multidimensional evaluation and approach is reported, along with a literature review.

"Role-sharing surgery": a new surgical education system that gives beginner surgeons more chances to operate while ensuring the surgical quality of robotic surgery.

It has been pointed out that robotic surgery is more time-consuming than laparoscopic surgery, and a major challenge for the future is educating young surgeons while maintaining the surgical quality. To solve these problems, we report a role-sharing surgery (RSS) approach in which the surgery is divided into several areas and timetabled, with roles shared by several operators. We performed RSS for 19 standard colorectal cancer surgeries. The surgery was completed within + 28 min of the scheduled operation time, and a beginner robotic surgeon (BRS) was able to perform approximately 66% of the total surgery. There were no statistically significant differences in the short-term outcomes between the RSS and conventional surgery groups. Based on these findings, RSS has the potential to be the best practice for educating BRSs in robotic surgery, the use of which is expected to increase steadily in the future.

Laparoscopic pancreas-preserving duodenectomy: Minimally invasive surgery for superficial nonampullary duodenal epithelial tumors.

No consensus exists regarding the optimal treatment for superficial nonampullary duodenal epithelial tumors. Herein, we describe a laparoscopic pancreas-preserving duodenectomy for the treatment of a 30-mm adenoma located in the third portion of the duodenum. The adenoma was located on the pancreatic side, further hindering safe endoscopic resection. Via laparoscopy, the jejunum was transected first. After releasing the third portion of the duodenum from the retroperitoneal space, the jejunum was pulled to the right side of the superior mesenteric artery and separated from the pancreas. Under endoscopic guidance, the duodenum was then transected and duodenojejunostomy performed intracorporeally. Laparoscopic pancreas-preserving duodenectomy can be considered minimally invasive, achieving tumor radicality while preserving organs and causing minimal destruction to the abdominal wall. In conclusion, although technically demanding, laparoscopic pancreas-preserving duodenectomy is a valuable treatment option for superficial nonampullary duodenal epithelial tumors.

Spontaneous regression of advanced transverse colon cancer with deficient mismatch repair: a case report.

BACKGROUND: Spontaneous regression (SR) of cancer occurs in 1 in 60,000-100,000 patients. This phenomenon has been reported in almost all cancer types, most commonly neuroblastoma, renal cell carcinoma, malignant melanoma, and lymphoma/leukemia. However, SR in colorectal cancer (CRC) is extremely rare, particularly in advanced cases. Hence, this report describes a very rare case of spontaneous regression of advanced transverse colon cancer. CASE PRESENTATION: A 76-year-old female with anemia was diagnosed with a type II well-differentiated adenocarcinoma in the middle transverse colon. Two months later, a second colonoscopy examination was performed for preoperative marking, and it revealed tumor shrinkage and a shift to type 0-IIc morphology. Endoscopic tattooing was then performed, followed by a laparoscopic partial resection of the transverse colon with D3 lymph node dissection. However, the resected specimen contained no tumor, and colonoscopy showed no tumor remnants in the remaining colon. Histopathological examination revealed mucosal regeneration and a mucus nodule in between the submucosal and muscular layers, with no cancer cells detected. Immunohistochemical analysis revealed the loss of MutL homolog 1 (MLH1) and postmeiotic segregation increased 2 (PMS2) expression in the cancer cells of biopsied specimens, suggesting deficient mismatch repair (dMMR). The patient continues to be followed up until 6 years postoperatively, and no recurrence has been observed. In this study, we also reviewed similar reported cases of spontaneous regression of cancer involving dMMR. CONCLUSION: This study presents a rare case of spontaneous regression of advanced transverse colon cancer wherein dMMR is strongly involved. However, further accumulation of similar cases is needed to elucidate this phenomenon and to develop new treatment strategies for CRC.

AZD6738 promotes the tumor suppressive effects of trifluridine in colorectal cancer cells.

Ataxia telangiectasia and Rad3­related (ATR) is a kinase that repairs DNA damage. Although inhibitors that selectively target ATR have been developed, their effectiveness in colorectal cancer has not been widely reported. The present study hypothesized that anticancer agents that effectively act in the S phase before the G2/M checkpoint may be ideal agents for concomitant use with ATR inhibitors, which act at the G2/M checkpoint. Therefore, the present study examined the combined effects of AZD6738, an ATR inhibitor, and trifluridine (FTD), which acts in the S phase and has a high DNA uptake rate. In vitro cell viability assays, flow cytometry and western blotting were performed to evaluate cell viability, and changes in cell cycle localization and protein expression. The results revealed that in colorectal cancer cells, the combination of AZD6738 and FTD inhibited cell viability, cell cycle arrest at the G2/M checkpoint and Chk1 phosphorylation, and increased apoptotic protein expression levels more than that when treated with FTD alone. HT29, a BRAF­mutant cell line known to be resistant to anticancer drugs, was used to induce tumors in vivo. Since FTD does not have sufficient efficacy when administered orally, it was mixed with tipiracil to prevent degradation; this mixture is known as TAS­102. TAS­102 alone exerted minimal tumor suppressive effects; however, when used in combination with AZD6738, tumor suppression was observed, suggesting that AZD6738 may increase the effectiveness of a weakly effective drug. Although ATR inhibitors are effective against p53 mutants, the present study demonstrated that these inhibitors were also effective against the p53 wild­type HCT116 colorectal cancer cell line. In conclusion, combination therapy with AZD6738 and FTD enhanced the inhibition of tumor proliferation in vitro and in vivo. In the future, we aim to investigate the potentiating effect of AZD6738 on 5­fluouracil­resistant cell lines that are difficult to treat.

Incomplete lymphatic sealing around the inferior mesenteric artery is a risk factor for chylous ascites in robotic rectal cancer surgery.

INTRODUCTION: Compared with laparoscopic surgery (LS), robotic surgery (RS) is considered to have acceptable outcomes in rectal cancer, but few reports have focused on chylous ascites in RS. The aim of this study was to investigate the incidence and etiology of chylous ascites after RS. METHODS: This retrospective study included 291 patients with rectal cancer who underwent RS (n = 165) or LS (n = 126) with high ligation of the inferior mesenteric artery (IMA). Propensity score matching (PSM) was performed to compare the two groups. RESULTS: \Dissection around the IMA was achieved using ultrasonic coagulating shears in most LS cases, and monopolar scissors in most RS cases, sometimes using bipolar vessel sealing device or bipolar forceps. The incidence of chylous ascites was 12.2% in RS and 4.1% in LS after PSM (P = .037). When limited to the RS group, multivariate analysis identified absence of lymphatic sealing at the left side of the IMA and shorter operative time as independent risk factors for chylous ascites. Except for duration of drain placement, no outcomes differed significantly with or without chylous ascites. One patient with chylous ascites developed later infection and required antibiotic treatment. CONCLUSION: The incidence of chylous ascites is significantly higher in RS than in LS, and RS with incomplete lymphatic sealing around the IMA is a risk factor for chylous ascites in rectal cancer. Although outcomes for patients with chylous ascites were acceptable, adequate lymphatic sealing during dissection around the IMA is crucial to prevent chylous ascites in RS.

Robot-assisted laparoscopic abdominoperineal resection with en bloc prostatectomy using the Retzius-sparing robot-assisted radical prostatectomy technique.

INTRODUCTION: The best surgical technique for rectal cancer invading the prostate remains controversial. Rectal resection with en bloc prostatectomy using a standard retropubic approach is an option but has disadvantages. We report a new surgical procedure applying Retzius-sparing robot-assisted radical prostatectomy. MATERIALS AND SURGICAL TECHNIQUE: First, the rectum was mobilized mainly at its dorsal side. Next, the prostate was separated from the bladder and urethra via the pouch of Douglas approach without opening the Retzius cavity, after which the surgical specimen was extracted through the perineal wound. Lateral pelvic lymph node dissection was performed after vesicourethral anastomosis. DISCUSSION: This new robotic procedure minimizes surgical trauma and preserves normal pelvic anatomy. Furthermore, this approach makes it easy to perform subsequent lateral pelvic lymph node dissection.

ATR inhibitor AZD6738 increases the sensitivity of colorectal cancer cells to 5­fluorouracil by inhibiting repair of DNA damage.

The repair of DNA damage caused by chemotherapy in cancer cells occurs mainly at two cell cycle checkpoints (G1 and G2) and is a factor contributing to chemoresistance. Most colorectal cancers harbor mutations in p53, the main pathway involved in the G1 checkpoint, and thus, are particularly dependent on the G2 checkpoint for DNA repair. The present study examined the effect of AZD6738, a specific inhibitor of ataxia telangiectasia mutated and rad3­related (ATR) involved in the G2 checkpoint, combined with 5­fluorouracil (5­FU), a central chemotherapeutic agent, on colorectal cancer cells. Since 5­FU has a DNA­damaging effect, its combination with AZD6738 is likely to enhance the therapeutic effect. The effects of the AZD6738/5­FU combination were evaluated in various colorectal cancer cells (HT29, SW480, HCT116 and DLD­1 cells) by flow cytometry (HT29 cells), western blotting (HT29 cells) and water­soluble tetrazolium 1 assays (HT29, SW480, HCT116 and DLD­1 cells), as well as in an experimental animal model (HT29 cells). In vitro, the AZD6738/5­FU combination increased the number of mitotic cells according to flow cytometry, decreased the checkpoint kinase 1 phosphorylation levels and increased cleaved caspase­3 and phosphorylated form of H2A.X variant histone levels according to western blotting, and decreased the proliferation rate of four colon cancer cell lines according to cell viability experiments. In vivo, xenografted colorectal cancer cells treated with the AZD6738/5­FU combination exhibited a marked decrease in proliferation compared with the 5­FU alone group. The present results suggested that AZD6738 enhanced the effect of 5­FU in p53­mutated colorectal cancer.

The Interaction Between Cancer-associated Fibroblasts and Cancer Cells Enhances Bcl-xL and Mcl-1 in Colorectal Cancer.

BACKGROUND/AIM: The acquisition of resistance to apoptosis is one of the biggest problems in colorectal cancer (CRC) treatment. This study aimed to elucidate the mechanisms of resistance to apoptosis with a focus on interleukin (IL)-6 produced by the interaction between cancer cells and cancer-associated fibroblasts (CAFs). MATERIALS AND METHODS: DLD-1 and HCT116 cell lines were treated with IL-6 and furthermore co-cultured with CAFs. The expression levels of Bcl-xL, Mcl-1 and phosphorylation of STAT3 were evaluated by western blotting. We also performed immunostaining for CRC specimens and evaluated the correlation between CAFs invasion and Bcl-xL/Mcl-1 expression. RESULTS: Both IL-6 and co-culturing enhanced Bcl-xL, Mcl-1 and the phosphorylation of STAT3. Immunohistochemistry showed a positive correlation between CAFs and Bcl-xL/Mcl-1. These results showed that the interaction between CAFs and cancer cells enhances Bcl-xL and Mcl-1 through the IL-6/STAT3 signaling pathway. CONCLUSION: Our findings provide new potential therapeutic targets and strategies for CRC treatment.

Chitinase 3-like 1 secreted from cancer-associated fibroblasts promotes tumor angiogenesis via interleukin-8 secretion in colorectal cancer.

The cancer­stromal interaction has been demonstrated to promote tumor progression, and cancer-associated fibroblasts (CAFs), which are the main components of stromal cells, have attracted attention as novel treatment targets. Chitinase 3-like 1 (CHI3L1) is a chitinase-like protein, which affects cell proliferation and angiogenesis. However, the mechanisms through which cells secrete CHI3L1 and through which CHI3L1 mediates tumor progression in the cancer microenvironment are still unclear. Accordingly, the present study assessed the secretion of CHI3L1 in the microenvironment of colorectal cancer and evaluated how CHI3L1 affects tumor angiogenesis. CAFs and normal fibroblasts (NFs) established from colorectal cancer tissue, and human colon cancer cell lines were evaluated using immunostaining, cytokine antibody array, RNA interference, reverse transcription-quantitative PCR (RT-qPCR), ELISA, western blotting and angiogenesis assays. The expression and secretion of CHI3L1 in CAFs were stronger than those in NFs and colorectal cancer cell lines. In addition, interleukin-13 receptor α2 (IL-13Rα2), a receptor for CHI3L1, was not expressed in colorectal cancer cell lines, but was expressed in fibroblasts, particularly CAFs. Furthermore, the expression and secretion of IL-8 in CAFs was stronger than that in NFs and cancer cell lines, and recombinant CHI3L1 addition increased IL-8 expression in CAFs, whereas knockdown of CHI3L1 suppressed IL-8 expression. Furthermore, IL-13Rα2 knockdown suppressed the enhancement of IL-8 expression induced by CHI3L1 treatment in CAFs. For vascular endothelial growth factor-A (VEGFA), similar results to IL-8 were observed in an ELISA for comparison of secretion between CAFs and NFs and for changes in secretion after CHI3L1 treatment in CAFs; however, no significant differences were observed for changes in expression after CHI3L1 treatment or IL-13Rα2 knockdown in CAFs assessed using RT-qPCR assays. Angiogenesis assays revealed that tube formation in vascular endothelial cells was suppressed by conditioned medium from CAFs with the addition of human CHI3L1 neutralizing antibodies compared with control IgG, and also suppressed by conditioned medium from CAFs transfected with CHI3L1, IL-8 or VEGFA small interfering RNA compared with negative control small interfering RNA. Overall, the present findings indicated that CHI3L1 secreted from CAFs acted on CAFs to increase the secretion of IL-8, thereby affecting tumor angiogenesis in colorectal cancer.

[A Case of Rectal Cancer with Lymph Node Metastasis Diagnosed as Intramucosal Cancer].

The patient was a 62-year-old man in whom 0-Ⅱa plus Ⅱc lesions in Rs were identified during follow-up observation of multiple colorectal polyps that were found during colonoscopy performed for the examination of fecal occult blood. CT showed no lymphadenopathy or distant metastasis to other organs. Laparoscopic-assisted high anterior resection of the rectum was performed with a diagnosis of clinical stage Ⅰ. Pathologically, there was a well-to-moderately differentiated tubular adenocarcinoma that remained in the lamina propria; however, 1 metastasis was found in the lymph node adjacent to the rectum(#251). Therefore, adjuvant chemotherapy was performed for 6 months after the operation, and 5 years have passed with no recurrence. Here, we report a case with no apparent submucosal invasion but with lymph node metastasis. We confirm recurrence-free survival for 5 years after surgery.

[Neutrophil-Lymphocyte Ratio as a Prognostic Indicator in Patients Treated with Nivolumab for Gastric Cancer].

BACKGROUND: Immune checkpoint inhibitors(nivolumab)have been recommended as third-line chemotherapy for advanced gastric cancer(AGC)according to the Guidelines of Gastric Cancer(5th edition). Therefore, they have been used in daily clinical practice. On the other hand, the neutrophil-lymphocyte ratio(NLR)has been reported to be associated with the prognosis of cancer patients. METHODS: Twenty patients treated with nivolumab for AGC between January 2018 and November 2019 were retrospectively examined. RESULTS: Median age of the 20 patients(18 males, 2 females)was 70 years(55- 84 years). Nivolumab was administered as second-, third-, fourth-, and fifth-line therapy in 1, 11, 7, and 1 case, respectively. The best tumor response evaluation was observed in PR 1, SD 7 and PD 10 cases. Median overall survival(OS)was 10 months, and median progression-free survival(PFS)was 3 months. No serious adverse events occurred. Compared to the NLR>2.0 group, OS significantly prolonged(2.2 months vs 21.9 months)and PFS tended to prolong(1.4 months vs 6.2 months)in the NLR≤2.0 group. CONCLUSION: NLR may be an effective prognostic factor in patients with AGC receiving nivolumab treatment.