Risk Factors for the Severity of Complications in Minimally Invasive Total Gastrectomy for Gastric Cancer: a Retrospective Cohort Study

Purpose@#Minimally invasive gastrectomy is a promising surgical method with well-known benefits, including reduced postoperative complications. However, for total gastrectomy of gastric cancers, this approach does not significantly reduce the risk of complications. Therefore, we aimed to evaluate the incidence and risk factors for the severity of complications associated with minimally invasive total gastrectomy for gastric cancer. @*Materials and Methods@#The study included 392 consecutive patients with gastric cancer who underwent either laparoscopic or robotic total gastrectomy between 2011 and 2019.Clinicopathological and operative characteristics were assessed to determine the features related to postoperative complications after minimally invasive total gastrectomy. Binomial and multinomial logistic regression models were used to identify the risk factors for overall complications and mild and severe complications, respectively. @*Results@#Of 103 (26.3%) patients experiencing complications, 66 (16.8%) and 37 (9.4%) developed mild and severe complications, respectively. On multivariate multinomial regression analysis, independent predictors of severe complications included obesity (OR, 2.56; 95% CI, 1.02−6.43; P=0.046), advanced stage (OR, 2.90; 95% CI, 1.13−7.43; P=0.026), and more intraoperative bleeding (OR, 1.04; 95% CI, 1.02−1.06; P=0.001). Operation time was the only independent risk factor for mild complications (OR, 1.06; 95% CI, 1.001−1.13; P=0.047). @*Conclusions@#The risk factors for mild and severe complications were associated with surgery, indicating surgical difficulty. Surgeons should be aware of these potential risks that are related to the severity of complications so as to reduce surgery-related complications after minimally invasive total gastrectomy for gastric cancer.

Omental Free-Shaped Flap Reinforcement on the Anastomosis and Dissected Area (OFFROAD) Following Reconstruction after Gastrectomy: A Retrospective Case-Control Study

The recent advancements in surgical techniques and perioperative care have improved postoperative morbidity and survival after gastric cancer surgeries. However, anastomotic leakage, the most serious complication post-gastrectomy, continues to occur. In esophageal and colorectal cancer surgeries, the omentum is used as a physical barrier and increases blood perfusion to prevent leakage to the anastomotic site. However, the use of the omentum as an anastomotic barrier after gastrectomy has not been reported yet. The authors aimed to evaluate the efficacy and safety of omental free-shaped flap reinforcement on the anastomosis and dissected area following reconstruction after gastrectomy for preventing and treating anastomotic leakage. They reported that omental free-shaped flap reinforcement on the anastomosis might prevent anastomotic leakage post-gastrectomy. The omental flap also prevented further deterioration when leakage occurred. However, anastomosis-related complications, such as anastomotic stenosis and delayed gastric emptying, after an omental patch technique need to be evaluated further.

Similar Operative Outcomes between the da Vinci Xi® and da Vinci Si® Systems in Robotic Gastrectomy for Gastric Cancer

PURPOSE: The robotic system for surgery was introduced to gastric cancer surgery in the early 2000s to overcome the shortcomings of laparoscopic surgery. The more recently introduced da Vinci Xi® system offers benefits allowing four-quadrant access, greater range of motion, and easier docking through an overhead boom rotation with laser targeting. We aimed to identify whether the Xi® system provides actual advantages over the Si® system in gastrectomy for gastric cancer by comparing the operative outcomes. MATERIALS AND METHODS: We retrospectively reviewed all patients who underwent robotic gastrectomy as treatment for gastric cancer from March 2016 to March 2017. Patients' demographic data, perioperative information, and operative and pathological outcomes were collected and analyzed. RESULTS: A total of 109 patients were included in the Xi® group and 179 in the Si® group. Demographic characteristics were similar in both groups. The mean operative time was 229.9 minutes in the Xi® group and 223.7 minutes in the Si® group. The mean estimated blood loss was 72.7 mL in the Xi® group and 62.1 mL in the Si® group. No patient in the Xi® group was converted to open or laparoscopy, while 3 patients in the Si® group were converted, 2 to open surgery and 1 to laparoscopy, this difference was not statistically significant. Bowel function was resumed 3 days after surgery, while soft diet was initiated 4 days after surgery. CONCLUSIONS: We found no difference in surgical outcomes after robotic gastrectomy for gastric cancer between the da Vinci Xi® and da Vinci Si® procedures.

Clinical Implications of Microsatellite Instability in Early Gastric Cancer

PURPOSE: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer.MATERIALS AND METHODS: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS).RESULTS: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423–2.054; P=0.861).CONCLUSIONS: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.

Feasibility of Linear-Shaped Gastroduodenostomy during the Performance of Totally Robotic Distal Gastrectomy

PURPOSE: Although linear-shaped gastroduodenostomy (LSGD) was reported to be a feasible and reliable method of Billroth I anastomosis in patients undergoing totally laparoscopic distal gastrectomy (TLDG), the feasibility of LSGD for patients undergoing totally robotic distal gastrectomy (TRDG) has not been determined. This study compared the feasibility of LSGD in patients undergoing TRDG and TLDG.MATERIALS AND METHODS: ALL C: onsecutive patients who underwent LSGD after distal gastrectomy for gastric cancer between January 2009 and December 2017 were analyzed retrospectively. Propensity score matching (PSM) analysis was performed to reduce the selection bias between TRDG and TLDG. Short-term outcomes, functional outcomes, learning curve, and risk factors for postoperative complications were analyzed.RESULTS: This analysis included 414 patients, of whom 275 underwent laparoscopy and 139 underwent robotic surgery. PSM analysis showed that operation time was significantly longer (163.5 vs. 132.1 minutes, P<0.001) and postoperative hospital stay significantly shorter (6.2 vs. 7.5 days, P<0.003) in patients who underwent TRDG than in patients who underwent TLDG. Operation time was the independent risk factor for LSGD after intracorporeal gastroduodenostomy. Cumulative sum analysis showed no definitive turning point in the TRDG learning curve. Long-term endoscopic findings revealed similar results in the two groups, but bile reflux at 5 years showed significantly better improvement in the TLDG group than in the TRDG group (P=0.016).CONCLUSIONS: LSGD is feasible in TRDG, with short-term and long-term outcomes comparable to that in TLDG. LSGD may be a good option for intracorporeal Billroth I anastomosis in patients undergoing TRDG.

Single Patient Classifier Assay, Microsatellite Instability, and Epstein-Barr Virus Status Predict Clinical Outcomes in Stage II/III Gastric Cancer: Results from CLASSIC Trial

PURPOSE: Clinical implications of single patient classifier (SPC) and microsatellite instability (MSI) in stage II/III gastric cancer have been reported. We investigated SPC and the status of MSI and Epstein-Barr virus (EBV) as combinatory biomarkers to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer. MATERIALS AND METHODS: Tumor specimens and clinical information were collected from patients enrolled in CLASSIC trial, a randomized controlled study of capecitabine plus oxaliplatin-based adjuvant chemotherapy. The results of nine-gene based SPC assay were classified as prognostication (SPC-prognosis) and prediction of chemotherapy benefit (SPC-prediction). Five quasimonomorphic mononucleotide markers were used to assess tumor MSI status. EBV-encoded small RNA in situ hybridization was performed to define EBV status. RESULTS: There were positive associations among SPC, MSI, and EBV statuses among 586 patients. In multivariate analysis of disease-free survival, SPC-prognosis [hazard ratio (HR): 1.879 (1.101–3.205), 2.399 (1.415–4.067), p=0.003] and MSI status (HR: 0.363, 95% confidence interval: 0.161–0.820, p=0.015) were independent prognostic factors along with age, Lauren classification, TNM stage, and chemotherapy. Patient survival of SPC-prognosis was well stratified regardless of EBV status and in microsatellite stable (MSS) group, but not in MSI-high group. Significant survival benefit from adjuvant chemotherapy was observed by SPC-Prediction in MSS and EBV-negative gastric cancer. CONCLUSION: SPC, MSI, and EBV statuses could be used in combination to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer.

The Role of Laparoscopic Necrosectomy in the Era of Minimally Invasive Treatment for Necrotizing Pancreatitis: A Case Series and Review of the Literature

PURPOSE: Despite the recent increasing application of minimally invasive techniques to treat necrotizing pancreatitis, few reports on laparoscopic necrosectomy have appeared. The aim of the present study was to evaluate the role played by laparoscopic necrosectomy in treatment of necrotizing pancreatitis. We review our own experience and the relevant literature. METHODS: All patients undergoing laparoscopic necrosectomy at Seoul National University Bundang Hospital from March 2005 to January 2016 were included in the study. Data on patient demographics, CT severity index score, American Society of Anesthesiologists' score, preoperative procedures, operative methods, operation time, estimated blood loss, postoperative complications, and length of hospital stay were retrospectively analyzed. We also performed an up-to-date review of the relevant literature. RESULTS: Laparoscopic necrosectomy was performed on four patients with infective pancreatic necrosis that was inadequately treated by percutaneous drainage. A transgastrocolic, transmesocolic, or retrocolic approach was used. The median time from diagnosis to operation was 57 days (range, 34~109 days) and the median operation time 203 min (range, 180~255 min). There was no operative mortality. The necrotic tissue was successfully removed in a single operation in three of the four patients. Three patients experienced postoperative complications, including pleural effusion and recurrence of necrosis. The median postoperative hospital stay was 39 days (range, 16~99 days). CONCLUSION: Laparoscopic necrosectomy is safe and effective when used to treat necrotizing pancreatitis. Such treatment is especially useful for patients with solid, necrotic pancreatic components that are not removed by percutaneous or endoscopic drainage.