Greater Curvature Research Articles

Endoscopic features of synchronous multiple early gastric cancers: Findings from a nationwide cohort.

We investigated the factors associated with synchronous multiple early gastric cancers and determined their localization. We analyzed 8191 patients who underwent endoscopic submucosal dissection for early gastric cancers at 33 hospitals in Japan from November 2013 to October 2016. Background factors were compared between single-lesion (n=7221) and synchronous multi-lesion cases (n=970) using univariate and multivariate analyses. We extracted cases with two synchronous lesions (n=832) and evaluated their localization. Significant independent risk factors for synchronous multiple early gastric cancer were older age (≥75 years old) (OR=1.257), male sex (OR=1.385), severe mucosal atrophy (OR=1.400), tumor localization in the middle (OR=1.362) or lower region (OR=1.404), and submucosal invasion (OR=1.528 (SM1), 1.488 (SM2)). Depressed macroscopic type (OR=0.679) and pure undifferentiated histology OR=0.334) were more common in single early gastric cancers. When one lesion was in the upper region, the other was more frequently located in the lesser curvature of the middle region. When one lesion was in the middle region, the other was more frequently located in the middle region or the lesser curvature of the lower region. When one lesion was in the lower region, the other was more frequently located in the lesser curvature of the middle region or the lower region. Factors associated with synchronous multiple early gastric cancer included older age, male sex, severe mucosal atrophy, tumor localization in the middle or lower region, and tumor submucosal invasion. Our findings provide useful information regarding specific areas that should be examined carefully when one lesion is detected.

Laparoscopic Spleen-Preserving Hilar Lymphadenectomy for Advanced Proximal Gastric Cancer Without Greater Curvature Invasion

Splenic hilar lymphadenectomy has been recommended for locally advanced proximal gastric cancer (APGC) involving the greater curvature. However, it is unclear whether laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPSHL) is associated with a long-term survival benefit for APGC without greater curvature invasion. To present the 5-year follow-up data from a randomized clinical trial that compared laparoscopic total gastrectomy (D2 group) with D2 plus LSPSHL (D2 + No. 10 group) among patients with resectable APGC. This is a post hoc secondary analysis of a randomized clinical trial that enrolled 536 patients with potentially resectable APGC (cT2-4a, N0 or N+, and M0) without greater curvature invasion from January 5, 2015, to October 10, 2018. All patients were tracked for at least 5 years. The final follow-up was on October 30, 2023. Patients were randomly assigned in a 1:1 ratio to the D2 + No. 10 or D2 groups. The 5-year disease-free survival (DFS) and overall survival (OS) rates were measured. Recurrence patterns and causes of death were compared. A total of 526 patients (392 men [74.5%]; mean [SD] age, 60.6 [9.6] years) were included in the modified intent-to-treat analysis, with 263 patients in each group. The 5-year DFS rate was 63.9% (95% CI, 58.1%-69.7%) for the D2 + No. 10 group and 55.1% (95% CI, 49.1%-61.1%) for the D2 group (log-rank P = .04). A statistically significant difference was observed in the 5-year OS between the D2 + No. 10 group and the D2 group (66.2% [95% CI, 60.4%-71.9%] vs 57.4% [95% CI, 51.4%-63.4%]; log-rank P = .03). The No. 10 lymph node exhibited a therapeutic value index (TVI) of 6.5, surpassing that of Nos. 8a (TVI, 3.0), 11 (TVI, 5.8), and 12a (TVI, 0.8). A total of 86 patients in the D2 + No. 10 group (cumulative incidence, 32.7%) and 111 patients in the D2 group (cumulative incidence, 42.2%) experienced recurrence (hazard ratio, 0.72; 95% CI, 0.54-0.95; P = .02). The multivariable competing risk regression model demonstrated that D2 + No. 10 remained an independent protective factor for a lower 5-year cumulative recurrence rate after surgery (hazard ratio, 0.75; 95% CI, 0.56-1.00; P = .05). There was a significant difference in the 5-year cumulative recurrence rate at the No. 10 lymph node area between the 2 groups (D2 + No. 10 group vs D2 group: 0% vs 2.3% [n = 6]; P = .01). This post hoc secondary analysis of a randomized clinical trial found that laparoscopic total gastrectomy with LSPSHL can improve the prognosis and reduce recurrence for APGC without greater curvature invasion. Future multicenter studies are warranted to validate these findings. ClinicalTrials.gov Identifier: NCT02333721.

Lesser omentum of white rats: structural and functional characteristics

Background. According to the literature, all mammals have two omenta, one of which is the greater omentum and the other one is the lesser omentum, but white rats have two additional derivatives of the visceral peritoneum, homologous in structure to the greater omentum - called the epididymal omentum. Today, the greater omentum is comprehensively studied and arouses great interest among researchers, in turn, the lesser omentum is not popular among scientists, as a result of which many details of its anatomical and histological structure remain undisclosed. Objective. To study the morpho-functional features of the structure of the lesser omentum of white rats through a bibliographic analysis of the literature. Methods. This bibliographic analysis is based on published articles, books, textbooks, and monographs. The search for which was carried out on the worldwide network "Internet" in the scientific and metric databases of Google Scholar, Web of Science and PubMed, foreign sources of literature and the National Library of Medicine. Results. The lesser omentum is formed due to the successive transition of the duplication of the peritoneum, from the lower surface of the liver to the lesser curvature of the stomach and duodenum. At the small curvature of the stomach, the leaves that form the lesser omentum diverge and cover the front-upper and back-lower walls of the stomach. The lesser omentum consists of the hepatogastric ligament, which is an extremely thin and transparent membrane, and a thicker, transparent membrane - the hepatoduodenal ligament, which is attached to the duodenum. Microscopically, it consists of two main structural elements: thin fenestrated translucent membranes and adipose tissue-rich areas containing milky spots that may play a role in the immune defense of the peritoneal cavity. Conclusion. So, according to the analysis, the lesser omentum mainly performs a connecting role and provides support and stabilization of the organs of the abdominal cavity between which it is located.

Case report: A rare case of very well-differentiated gastric adenocarcinoma of gastric type with a lymphovascular invasion

BackgroundVery well-differentiated gastric adenocarcinoma (VWDA) is a rare variant of gastric cancer, for which the diagnostic criteria and clinical behavior are not fully established. We reported a case of an intramucosal VWDA of gastric type with a lymphovascular invasion (LVI).Case presentationA 67-year-old female was diagnosed as intramucosal gastric adenocarcinoma after a biopsy at the local hospital 3 weeks ago and then visited our hospital for further treatment. The endoscopic examination in our hospital showed a rough, slightly faded, 30-mm, flat, and elevated lesion on the lesser curvature of the middle gastric body. Histopathologically, the lesion consisted of superficial foveolar-type papillary adenocarcinoma and deep pyloric gland-type tubular adenocarcinoma. The immunostaining results showed that the foveolar-type papillary adenocarcinoma was positive for MUC5AC and had a high index of Ki-67, but the pyloric gland-type tubular adenocarcinoma was positive for MUC6 and had a low index of Ki-67. Both components were negative for MSH2 and MSH6, which suggested the high microsatellite instability phenotype. Moreover, a LVI was detected in the lesion. The pathological diagnosis was VWDA of gastric type.ConclusionThe case has unique histological and immunophenotypic characteristics, which not only indicates the importance of architectural features in the diagnosis of VWDA but also further proves that the aggressive behavior of VWDA is correlated with tumor histological type and immunophenotype.

Lymphatic spread from left-sided intrahepatic cholangiocarcinoma: reconsiderations based on the lymphatic drainage from the liver

Intrahepatic cholangiocarcinoma (ICC) is known to have a high frequency of lymph node metastasis. Lymph node dissection (LND) is recommended for accurate staging, but the survival benefit of LND remains unclear. Knowledge of the pathways and direction of lymphatic drainage to the regional lymph nodes is essential when considering LND to improve patient survival. The liver has three lymphatic drainage pathways: portal, sublobular, and subcapsular. Of these, the portal lymphatic pathway, which lies along with the portal tracts, is the primary pathway. The efferent portal lymphatic vessels from the left-sided liver, which continue from the portal lymphatic pathway of the liver, communicate with the lymphatic vessels and lymph nodes along the hepatic artery at the hepatoduodenal ligament. In addition, lymphatic flow may also present along the left embryonic (aberrant) hepatic artery in the lesser omentum, based on our experience. This pathway is the previously reported pathway from the left-sided ICC to the lesser curvature of the stomach. However, through this pathway, ICC cells reach lymph nodes along the root of the left gastric artery but not the perigastric lymph nodes along the lesser curvature because of the opposite direction of lymph flow. Although further analyses using a large number of cases are needed to confirm these observations, these two pathways, along the hepatic artery at the hepatoduodenal ligament and the left embryonic (aberrant) hepatic artery in the lesser omentum should be considered when performing LND in the case of ICC in the left-sided liver.

Retrospective observational cohort study of laparoscopic surgical strategies for gastrointestinal stromal tumors.

Laparoscopic surgery has been used to treat gastric submucosal tumors (SMTs). Laparoscopic and endoscopic cooperative surgery (LECS) has been used when subtotal resection has been difficult, which enabled resection of these tumors. In this study, we reviewed the medical records of patients with gastric SMTs who underwent laparoscopic surgery in our hospital with the aim of reporting the surgical indications, procedures (especially for LECS), and outcomes of surgery. This study involved 55 patients who underwent laparoscopic surgery between April 2014 and March 2021. We classified the patients into two groups: laparoscopy-assisted surgery group (non-LECS group, n = 30) and LECS group (n = 25). LECS was performed in the upper stomach, in the greater curvature of the lower stomach, and in both intraluminal and intramural locations in the middle stomach. Non-LECS was selected for extraluminal and intramural tumors in the greater curvature of the upper stomach. There were no severe complications associated with the operation. There was one postoperative complication in the LECS group. The length of postoperative hospital stay did not significantly differ between the LECS and non-LECS groups. We reported the surgical procedures for gastric SMTs in our hospital. It is essential to make full use of the multiple techniques reported in this article and examine the location of the tumor to avoid excess or insufficient resection. Our review of the present case series allowed us to select the appropriate surgical approach for gastric SMTs based on the lesion location and type of development.

A clinicopathologic feature-based nomogram for preoperative estimation of splenic hilar lymph node metastasis in advanced proximal gastric cancer without invasion of the greater curvature

BackgroundThe indications for splenic hilar lymph node dissection in advanced proximal gastric cancer without invasion of the greater curvature are controversial. We aimed to develop a preoperative nomogram for individualized prediction of splenic hilar lymph node metastasis in non–greater curvature advanced proximal gastric cancer. MethodsFrom January 2014 to December 2021, 558 patients with non–greater curvature advanced proximal gastric cancer who underwent D2 lymphadenectomy (including splenic hilar lymph node) were retrospectively analyzed and divided into a training cohort (n = 361) and validation cohort (n = 197), depending on the admission time. A preoperative predictive nomogram of splenic hilar lymph node metastasis was established based on independent predictors identified by multivariate analysis, and the performance and prognostic value were confirmed. ResultsIn the training and validation cohorts, 48 (13.3%) and 24 patients (12.2%) had pathologically confirmed splenic hilar lymph node metastasis, respectively. Tumor located in the posterior wall, tumor size ≥5 cm, Borrmann type IV, and splenic hilar lymph node lymphadenectasis on computed tomography were preoperative factors independently associated with splenic hilar lymph node metastasis. The nomogram developed based on these four parameters had a high concordance index of 0.850 (95% confidence interval, 0.793–0.907) and 0.825 (95% confidence interval, 0.743–0.908) in the training and validation cohorts, respectively, with well-fitting calibration plots and better net benefits in the decision curve analysis. In addition, disease-free survival and overall survival were significantly shorter in the high-risk group, with hazard ratios of 3.660 (95% confidence interval, 2.228–6.011; log-rank P < .0001) and 3.769 (95% confidence interval, 2.279–6.231; log-rank P < .0001), respectively. ConclusionThe nomogram has good performance in predicting the risk of splenic hilar lymph node metastasis in non–greater curvature advanced proximal gastric cancer preoperatively, which can help surgeons make rational clinical decisions.

Gastrin: a new branch of the gastropancreatic axis that can explain the effect of sleeve gastrectomy on glucose metabolism

BackgroundAmong bariatric techniques, sleeve gastrectomy (SG) stands out owing to its efficiency. The role of the stomach as a secretory organ of many substances, such as gastrin, related to insulin secretion is well known. Gastrin induces insulin release in isolated pancreatic islets, limiting somatostatin-14 intraislet release, and has been associated with blood glucose level improvement in diabetic models after SG. SG involves gastric resection along the greater curvature. This study aimed to determine the role of gastrin in glucose metabolism improvement after SG with the aid of the gastrin antagonist netazepide. MethodsIn 12 sham-operated, 12 SG-operated, and 12 SG-operated/netazepide-treated Wistar rats, we compared medium- and long-term plasma insulin, oral glucose tolerance test (OGTT) results, and plasma gastrin levels. In addition, gastrin expression was assessed in the gastric remnant, and the beta-cell mass was measured. ResultsSG induced a medium-term elevation of the insulin response and plasma gastrin levels without modification of the OGTT results. However, long-term depletion of the insulin response with elevated OGTT areas under the curve and plasma gastrin levels appeared after SG. Netazepide prevented the SG effect on these parameters. Gastrin tissue expression was greater in SG animals than in SG/netazepide-treated or control animals. The beta-cell mass was lower in the SG group than in the control or SG/netazepide group. ConclusionGastrin plays a central role in glucose improvement after SG. It stimulates a medium-term strong insulin response but also causes long-term beta-cell mass depletion and a loss of insulin response. These effects are prevented by gastrin antagonists such as netazepide.

Endoscopic sleeve gastroplasty: the identification of the key procedural steps through a modified Delphi method

BackgroundEndoscopic sleeve gastroplasty (ESG) is an innovative, minimally invasive bariatric procedure with an excellent safety and efficacy profile in adults with obesity. The purpose of the procedure is to shorten and tubularize the stomach along its greater curvature. Nevertheless, there are some heterogeneities in the approach to ESG, which will be important to address as the procedure sees increasingly widespread clinical adoption. Here, an expert consensus on standardized ESG techniques is presented. MethodsThe modified Delphi method was used to establish the key procedural steps of an ESG. A panel of 8 experts was selected, of which 6 participated. The panel was selected based on their experience with performing the procedure and consisted of 1 bariatric surgeon and 5 interventional gastroenterologists. A neutral facilitator was designated and produced a skeletonized initial version of the key steps that was sent to each expert. Each survey began with the experts rating the given steps on a Likert scale of 1 to 5, with 1 being the most inaccurate and 5 being the most accurate. Furthermore, the final product was rated. The survey continued with open-ended questions designed to revise and polish the key steps. Areas of discrepancy were addressed using binary questions and a majority vote. The respondents were given 10 days to complete each survey. At the end of each round, the survey was redistributed with updated key steps and questions. This process was continued for a predesignated 3 rounds. ResultsOf the 8 experts who were queried, 6/8, 5/8, and 5/8 replied to each round. The given ratings for the accuracy of the steps in each round were 4.2, 4.6, and 4.4. The final rating was 4.8. Although expert opinion varied around smaller portions of the procedure, such as the placement of an overtube and the shape of each suture line, there was consensus on the need for full-thickness bites and appropriate swirling of the tissue with the helix device. Whether or not to include the fundus in the gastroplasty was an additional area of discrepancy. Of note, 4 of 5 experts agreed that the fundus should remain intact. The final protocol consisted of 21 steps curated from the summarized responses of the experts. ConclusionUsing the modified Delphi method, 21 key steps have been described for a safe and effective ESG. This rubric will be standardized across institutions and practitioners. Furthermore, these findings allow for the generation of educational assessment tools to facilitate training and increase the adoption of ESG by endoscopists.

Bilateral Dorsal Nail Curvature of the Thumb Distal Phalanx - A Case Report.

Congenital dorsal curvature of the distal phalanx has been previously described as 'reverse Kirner' or 'ski-jump' deformity. This report describes bilateral occurrence in the thumbs. A 13-year-old male presented with difficulty caring for his thumbnails and in picking up small objects. Examination showed dorsal curvature of the distal phalanges of both thumbs, with greater curvature of the right side. Radiographs showed wedge-shaped epiphyses and dorsal curvature without coronal plane deviation of the distal phalanges. There was objective and subjective decrease in function associated with lateral pinch and tripod grasp. The reported aetiopathogenesis for Kirner deformity cannot explain the observed dorsal curvature. The bilateral nature makes a secondary physeal cause unlikely and suggests an embryologic basis. Due to the noticeable deficits in function, operative intervention may be warranted. Level of Evidence: Level V (Therapeutic).

Risk factors for intraoperative and delayed perforation related with gastric endoscopic submucosal dissection.

Perforation is one of the most important complications of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Several studies have examined risk factors for intraoperative and delayed perforations, but most were retrospective analyses with small numbers of patients. This study represents a secondary analysis of a Japanese multicenter prospective cohort study. We investigated the factors associated with each type of perforation using 9015 patients with 9975 EGCs undergoing ESD between July 2010 and June 2012. Intraoperative perforation occurred in 198 patients (2.2%) with 203 lesions (2.0%), necessitating emergency surgery for four lesions (0.04% [2.0%, 4/203]). Delayed perforation occurred in another 37 patients (0.4%) with 42 lesions (0.4%), requiring emergency surgery for 12 lesions (0.12% [28.6%, 12/42]). Factors showing significant independent correlations with intraoperative perforation were upper or middle third of the stomach; remnant stomach or gastric tube; procedure time ≥100min; tumor size >35mm; body mass index (BMI)<18.5kg/m2; and ≥72years. Factors showing significant independent correlations with delayed perforation were procedure time ≥60min; BMI<18.5kg/m2; ≥75years; ulceration; and tumor size >20mm. Intraoperative perforation occurred most frequently at the greater curvature in the upper third of the stomach (7.9%), whereas delayed perforation occurred most frequently at the greater curvature in the middle third (1.2%). This multicenter prospective cohort study clarified the risk and risk factors of intraoperative and delayed perforation related to ESD for EGCs, providing information to help endoscopists reduce perforation.

A case of young male with recurrent acute pancreatitis caused by an intrapancreatic gastric duplication cyst.

Gastric duplication cyst (GDC) is a rare gastrointestinal malformation that frequently occurs in the greater curvature of the gastric antrum or corpus. Herein, we reported a case of intrapancreatic GDC found as a result of recurring pancreatitis. A 15-year-old man experienced repeated episodes of acute pancreatitis and was found to have a cystic lesion in the pancreatic tail. Contrast-enhanced computed tomography revealed a 20-mm cystic lesion with an enhanced thick wall. Endoscopic ultrasonography revealed an anechoic cyst with a three-layered wall. Magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography (ERP) revealed a connection between the cyst and the main pancreatic duct (MPD), and the duplication of the MPD. ERP showed the pancreatic duct stenosis downstream of the cyst. Although preoperative diagnosis was difficult, distal pancreatectomy was performed to prevent recurrence of pancreatitis. Pathological examination revealed that the cystic lesion was circumferentially surrounded by the pancreatic parenchyma. The epithelial lining of the cyst was crypt epithelium containing the fundic or pyloric glands and surrounded by a smooth muscle layer. The final diagnosis was intrapancreatic GDC.

An operative case of gastric cancer with ectopic bile duct drainage in the lesser curvature of the stomach

BackgroundAmong the various anomalies of the biliary system, a double common bile duct with ectopic drainage in the stomach is rare. Furthermore, ectopic bile ducts are extremely rare in gastric cancers.Case presentationA 67-year-old man was admitted to our hospital with gastric cancer and ectopic left extrahepatic bile duct drainage in the stomach. Pre-operative testing revealed no communication between the intrahepatic bile ducts. Distal gastrectomy and bile duct jejunostomy were performed. The post-operative course was uneventful, and the patient did not exhibit recurrence for 39 mo.ConclusionsAlthough it is uncertain whether sustained bile exposure from an ectopic bile duct is related to gastric cancer, short-term follow-up might be necessary because of the possibility of gastric cancer.

Using a novel hemostatic peptide solution to prevent bleeding after endoscopic submucosal dissection of a gastric tumor.

Endoscopic mucosal dissection has become the standard treatment for early gastric cancer. However, post-endoscopic submucosal dissection (ESD) ulcer occurs in 4.4% of patients. This study hypothesized whether applying PuraStat, a novel hemostatic peptide solution, prevents post-ESD bleeding. To investigate the preventive potential of PuraStat, a hemostatic formulation, against bleeding in post-ESD gastric ulcers. Between May 2022 and March 2023, 101 patients (Group P) underwent ESD for gastric diseases at our hospital and received PuraStat (2 mL) for post-ESD ulcers. We retrospectively compared this group with a control group (Group C) comprising 297 patients who underwent ESD for gastric diseases at our hospital between April 2017 and March 2021. P values < 0.05 on two-sided tests indicated significance. Post-ESD bleeding occurred in 6 (5.9%) (95%CI: 2.8-12.4) and 20 (6.7%) (95%CI: 4.4-10.2) patients in Groups P and C, respectively, with no significant between-group difference. The relative risk was 1.01 (95%CI: 0.95-1.07). The lesser curvature or anterior wall was the bleeding site in all 6 patients who experienced postoperative bleeding in Group P. In multivariate analysis, the odds ratios for resection diameter ≥ 50 mm and oral anticoagulant use were 6.63 (95%CI: 2.52-14.47; P = 0.0001) and 4.04 (1.26-0.69; P = 0.0164), respectively. The adjusted odds ratio of post-ESD bleeding and PuraStat was 1.28 (95%CI: 0.28-2.15). PuraStat application is not associated with post-ESD bleeding. However, the study suggests that gravitational forces may affect the effectiveness of applied PuraStat.

An Uncommon Tumor in Stomach in A Young Girl

Introduction: Gastrointestinal stromal tumours (GIST) are rare tumours of the Gastrointestinal tract. They are the most common mesenchymal tumour of the gastrointestinal tract. All GISTs are malignant.Among all Gastrointestinal tract malignancies GIST Comprises 0.1- 3%. The most common location is stomach. They are usually found in elderly and they are not common in pediatric age group. Case Report: A girl aged 16 years presented with the history of melena, hematemesis with dyspepsia. Physical examination revealed mild tenderness over right hypochondrium. On examination, multiple hypopigmented patches noted over both upper limbs. CECT abdomen showed a well-defined heterogeneously enhancing predominantly exophytic necrotic soft tissue SOL over the greater curvature of the proximal body of the stomach with intraluminal extension. Her complete blood count and routine biochemical tests were within normal limits. Endoscopic biopsy from the polyploid lesion along the greater curvature show fragmented bits of gastric mucosa involved by a tumour composed of sheets and fascicles of round to oval cells having eosinophilic to vacuolated cytoplasm and a few spindle cells. Histopathological examination revealed a mesenchymal neoplasm favouring GIST.. Then wide local excision of the stomach was done and sent for histopathological examination. The stomach mass was diagnosed as Epithelioid GIST which was confirmed by immunohistochemistry. Conclusion: GISTs are most common mesenchymal tumours of GI tract. They are malignant in nature. The primary treatment of choice is surgery followed by chemotherapy.

George Sclavunos (1869-1954): Anatomical Insights and his contribution into the “Magenstrasse of Waldeyer”

The purpose of this article is to present a well-known physician and highlight his contribution into an essential, but neglected anatomical feature. George Sclavunos (1869-1954) was a 20th century Greek physician, whose scientific work was a significant milestone in global medical knowledge. In 1899 he became Professor of Anatomy and Head Director of the Department of Anatomy. In 1906 Sclavunos G. published the first volume of the three volume book “Human Anatomy” (1906-1926), which is characterized by its unparalleled illustrations. For more than a century it was the most important book of medical literature in Greece. In 1926 he became a Full Member of the Academy of Athens and was named Life Partner of the International Anatomi- cal Society. His interests included Anatomy, Physiology, Histology, as well as Osteology and Syndesmology. In his book “Human Anatomy”, he described for first time the “Sialine Groove of the Stomach”, which was described by Waldeyer-Hartz almost at the same time as the “Magenstrasse”, a German word that means “stomach road”. It is a ribbon-like path that extends along the lesser curvature of the stomach from the gastric cardia to the antrum and releases the gastric content directly into the small intestine. Its importance is confirmed by its association not only with drug delivery, but also with anti-obesity surgical techniques. The old German term has come back into common medical usage in view of the commonly performed Magenstrasse and Mill pro- cedure, a form of bariatric surgery.&#x0D; Conclusion: Sclavunos G. managed to observe an anatomical structure that has remained of great importance until today.

Conversion surgery for stage IV gastric cancer with multiple liver metastases with a complete pathological response to S-1 plus oxaliplatin therapy.

Although patients with stage IV gastric cancer who respond well to systemic chemotherapy can be treated with gastrectomy, the prognosis of patients with multiple liver metastases is poor. We herein describe a patient with stage IV gastric cancer with multiple liver metastases who underwent conversion surgery after systemic treatment with S-1 plus oxaliplatin. The patient was a 62-year-old man. Upper gastrointestinal endoscopy revealed a 30-mm type 2 tumor in the greater curvature of the stomach at the anterior wall, and biopsy revealed a poorly differentiated adenocarcinoma. Imaging showed three suspected liver metastases in liver segment S8. The patient was judged to have gastric cancer, cStage IV (cT3N1M1(H)), and systemic chemotherapy was administered. He was treated with a total of six courses of chemotherapy. After re-evaluation, the primary tumor had shrunk significantly, and liver metastases could not be detected. Confirming no signs of seeding by laparoscopy, robot-assisted pylorus-preserving gastrectomy with D2 dissection and laparoscopic partial hepatic (S8) resection were performed. The patient was diagnosed with a complete pathological response. Conversion surgery is an option for stage IV gastric cancer when distant metastases are controlled with chemotherapy and when R0 resection is possible.

Double-nylon purse-string suture in closing postoperative wounds following endoscopic resection of large (≥ 3 cm) gastric submucosal tumors.

Endoscopic full-thickness resection (EFTR) of gastric submucosal tumors (SMTs) is safe and effective; however, postoperative wound management is equally important. Literature on suturing following EFTR for large (≥ 3 cm) SMTs is scarce and limited. To evaluate the efficacy and clinical value of double-nylon purse-string suture in closing postoperative wounds following EFTR of large (≥ 3 cm) SMTs. We retrospectively analyzed the data of 85 patients with gastric SMTs in the fundus of the stomach or in the lesser curvature of the gastric body whose wounds were treated with double-nylon purse-string sutures after successful tumor resection at the Endoscopy Center of Renmin Hospital of Wuhan University. The operative, postoperative, and follow-up conditions of the patients were evaluated. All tumors were completely resected using EFTR. 36 (42.35%) patients had tumors located in the fundus of the stomach, and 49 (57.65%) had tumors located in the body of the stomach. All patients underwent suturing with double-nylon sutures after EFTR without laparoscopic assistance or further surgical treatment. Postoperative fever and stomach pain were reported in 13 (15.29%) and 14 (16.47%) patients, respectively. No serious adverse events occurred during the intraoperative or postoperative periods. A postoperative review of all patients revealed no residual or recurrent lesions. Double-nylon purse-string sutures can be used to successfully close wounds that cannot be completely closed with a single nylon suture, especially for large (≥ 3 cm) EFTR wounds in SMTs.

Abstract B091: Mechanisms underlying the omental support of ovarian cancer peritoneal metastasis

Abstract More than 80% of ovarian cancer (OC) cases have metastasized to the peritoneal cavity at diagnosis. The five-year survival rate for these patients is 25%. Within the peritoneal cavity, the most common and early site of metastasis is the omentum, a well-vascularized, specialized adipose tissue that arises off the greater curvature of the stomach. Because OC homes to the omentum, it is removed as a standard of care for patients with peritoneal metastases. In mouse models, the omentum is also an early metastatic site, and omentectomy reduces tumor expansion. The mechanism by which the omentum promotes OC growth is unknown, perhaps due to the complex omental microenvironment. The omentum contains many features that could impact OC seeding. It is covered by a mesothelial lining that extends in a sheet anchoring the omentum to surrounding tissues and is highly perfused by blood vessels. It contains lymphoid aggregates or milky spots that may contribute to pro- and anti-tumor immunity. This study explores the association of OC metastases with specific omentum features. We intraperitoneally injected luciferase-expressing ID8 OC cells to mimic high-grade serous OC metastasis. Using high-resolution, spatial ex vivo bioluminescence imaging (BLI), we found that tumor nodules preferentially formed in adipocyte-rich regions of the omentum and the mesentery, another peritoneal tissue favorable for OC seeding. To determine whether adipocytes, the most abundant omental cell type, are the primary support of OC, we crossed Adiponectin Cre+ and DTA mice to generate mice lacking white and brown adipocytes from birth. To overcome the metabolic syndrome the fatless mice develop, they receive subcutaneous fat transplants dorsally, referred to as distal adipocyte rescue of lipodystrophy (DARL) mice. Littermate controls receive sham surgeries. The blood triglyceride, glucose, and insulin levels are normalized post-transplant. Thus, the peritoneal cavity lacks mature adipocytes, but the mice have typical metabolic profiles, allowing us to study the role of omental adipocytes in peritoneal metastasis. Once the mice recovered from surgery, they were intraperitoneally injected with luciferase-expressing ID8s. While it was hypothesized that OC metastatic seeding within the adipocyte-free omentum and associated peritoneum would be impaired without local mature adipocytes, BLI revealed that the tumor burden was not decreased in DARL mice. Notably, specific regions of OC seeding, where mature adipocytes would have localized if present, such as the omentum and mesentery, retained tumor nodules in DARL mice. This conserved OC localization suggests that other cells in this specific microenvironment might be responsible for metastatic spread. To identify these cells, studies are ongoing to profile these regions in the DARL and control mice via flow cytometry and single-cell RNA sequencing. By unraveling the support for OC cells in the omentum, therapeutic strategies can be identified to repolarize the metastatic milieu and halt further spread to improve patient outcomes. Citation Format: Rachel Mintz, Alexandre Gallerand, Jichang Han, Sarah Ning, Wei Zou, Mary Wohltmann, Bernd Zinselmeyer, Gwendalyn Randolph. Mechanisms underlying the omental support of ovarian cancer peritoneal metastasis [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B091.

Gallbladder sinistroposition (left-sided) finding in laparoscopic cholecystectomy, a case report

A left-sided gallbladder (LSGB), also known as sinistropostition, is a rare anatomical variant with a reported incidence of 0.2-1.1%. It is defined as a gallbladder located on the left side of the falciform ligament, embedded in the third hepatic lobe, without situs inversus viscerum. A 37-year-old Latino man with a history of bilateral inguinal repair underwent a scheduled laparoscopic cholecystectomy due to multiple gallbladder polyps. Preoperative ultrasound reported a gallbladder of 60x20 mm, wall thickness of 1 mm, with polyps of up to 10 mm. Standard laparoscopic cholecystectomy trocar placement was used. Upon revision of the right hepatic lobe, there was an absence of the GB in the visceral side of segments IV, V, or VI. It was identified to the left of the falciform ligament with adhesions to the anterior and superior portions of the pylorus and lesser curvature. The subxiphoid trocar was adjusted to the left of the falciform ligament, and Calot’s triangle dissection was performed to obtain a critical view of safety. No other anatomical variants were identified. The procedure was performed safely with a satisfactory view of critical cholecystectomy steps and anatomy identification. After the procedure, the surgeon complained of right-hand pain and numbness due to a medial position of the subxiphoid trocar for dissection. The surgical approach of a LSGB in laparoscopic surgery should be individualized for each patient. A minimally invasive approach may be realized successfully when critical thinking by the surgeon is applied and always prioritizing the safety of the patient.