Precise highlighting of the pancreas by semantic segmentation during robot-assisted gastrectomy: visual assistance with artificial intelligence for surgeons.

BACKGROUND: A postoperative pancreatic fistula (POPF) is a critical complication of radical gastrectomy for gastric cancer, mainly because surgeons occasionally misrecognize the pancreas and fat during lymphadenectomy. Therefore, this study aimed to develop an artificial intelligence (AI) system capable of identifying and highlighting the pancreas during robot-assisted gastrectomy. METHODS: A pancreas recognition algorithm was developed using HRNet, with 926 training images and 232 validation images extracted from 62 scenes of robot-assisted gastrectomy videos. During quantitative evaluation, the precision, recall, intersection over union (IoU), and Dice coefficients were calculated based on the surgeons' ground truth and the AI-inferred image from 80 test images. During the qualitative evaluation, 10 surgeons answered two questions related to sensitivity and similarity for assessing clinical usefulness. RESULTS: The precision, recall, IoU, and Dice coefficients were 0.70, 0.59, 0.46, and 0.61, respectively. Regarding sensitivity, the average score for pancreas recognition by AI was 4.18 out of 5 points (1 = lowest recognition [less than 50%]; 5 = highest recognition [more than 90%]). Regarding similarity, only 54% of the AI-inferred images were correctly differentiated from the ground truth. CONCLUSIONS: Our surgical AI system precisely highlighted the pancreas during robot-assisted gastrectomy at a level that was convincing to surgeons. This technology may prevent misrecognition of the pancreas by surgeons, thus leading to fewer POPFs.

Subcutaneous emphysema associated with laparoscopic or robotic abdominal surgery: a retrospective single-center study.

BACKGROUND: Subcutaneous emphysema (SCE) is a common complication in laparoscopic surgery. However, its precise incidence and impact on the clinical course are partially known. In this study, the incidence and risk factors of SCE were retrospectively analyzed. METHODS: Patients who underwent laparoscopic/robotic abdominal surgery (e.g., gastrointestinal, hepatobiliary, gynecologic, and urologic surgery) between October 2019 and September 2022 were retrospectively analyzed. The presence of SCE was confirmed by either conclusive findings obtained through chest/abdominal X-ray examination immediately after operation, or intraoperative palpation conducted by nurses. X-ray examination was performed in the operation room before extubation. RESULTS: A total of 2503 patients treated with laparoscopic/robotic abdominal surgery between October 2019 and September 2022 were identified and all of them were included in the analysis. SCE was confirmed in 23.1% of the patients (i.e., 577/2503). SCE was identified by X-ray examination in 97.6% of the patients. Extubation failure was observed in 10 patients; however, pneumothorax was not observed. Female sex (odds ratio [OR]: 2.09; 95% confidence interval [95%CI]: 1.69-2.57), age ≥ 80 years (OR 1.63; 95%CI 1.19-2.22), body mass index < 20 (OR 1.32; 95%CI 1.06-1.65), operation time > 360 min (OR 1.97; 95%CI 1.53-2.54), robotic surgery (OR 2.54; 95%CI 1.91-3.38), maximum intraabdominal pressure with CO2 > 15 mmHg (OR 1.79; 95%CI 1.02-3.16), and endo-tidal CO2 > 50 mmHg (OR 1.32; 95%CI 1.08-1.62)were identified as independent factors of SCE. Regarding the extubation failure due to SCE, age (OR 5.84; 95%CI 1.27-26.8) and maximum intraabdominal pressure with CO2 (OR 21.7; 95%CI 4.76-99.3) were identified as risk factors. CONCLUSION: Although the presence of SCE is associated with a low risk of severe complications, monitoring of the perioperative intraabdominal pressure is essential for performing safe laparoscopic/robotic surgery, particularly in elderly patients.

Pterostilbene Induces Apoptosis from Endoplasmic Reticulum Stress Synergistically with Anticancer Drugs That Deposit Iron in Mitochondria.

Anticancer agents are playing an increasing role in the treatment of gastric cancer (GC); however, novel anticancer agents have not been fully developed. Therefore, it is important to investigate compounds that improve sensitivity to the existing anticancer drugs. We have reported that pterostilbene (PTE), a plant stilbene, enhances the antitumor effect of low doses of sunitinib in gastric cancer cells accumulating mitochondrial iron (II) (mtFe) at low doses. In this study, we investigated the relationship between the mtFe deposition and the synergistic effect of PTE and different anticancer drugs. For this study, we used 5-fluorouracil (5FU), cisplatin (CPPD), and lapatinib (LAP), which are frequently used in the treatment of GC, and doxorubicin (DOX), which is known to deposit mtFe. A combination of low-dose PTE and these drugs suppressed the expression of PDZ domain-containing 8 (PDZD8) and increased mtFe accumulation and mitochondrial H2O2. Consequently, reactive oxygen species-associated hypoxia inducible factor-1α activation induced endoplasmic reticulum stress and led to apoptosis, but not ferroptosis. In contrast, 5FU and CDDP did not show the same changes as those observed with PTE and DOX or LAP, and there was no synergistic effect with PTE. These results indicate that the combination of PTE with iron-accumulating anticancer drugs exhibits a strong synergistic effect. These findings would help in developing novel therapeutic strategies for GC. However, further clinical investigations are required.

Incidence and risk factors for venous thromboembolism in the Cancer-VTE Registry stomach cancer subcohort.

BACKGROUND: The Cancer-VTE Registry was a large-scale, multicenter, prospective registry designed to investigate real-world data on venous thromboembolism (VTE) incidence and risk factors in adult Japanese patients with solid tumors. This pre-specified subgroup analysis aimed to estimate the incidence of VTE, including VTE types other than symptomatic VTE, and identify risk factors of VTE in stomach cancer from the Cancer-VTE Registry. METHODS: Stage II-IV stomach cancer patients who planned to initiate cancer therapy and underwent VTE screening within 2 months before registration were enrolled. RESULTS: Of 1,896 patients enrolled, 131 (6.9%) had VTE at baseline, but 96.2% were asymptomatic. Female sex, age ≥ 65 years, VTE history, and D-dimer > 1.2 µg/mL were independent risk factors of VTE at baseline. Notably, patients with D-dimer > 1.2 µg/mL at the time of cancer diagnosis had an approximately 20-fold risk of VTE. During follow-up, event incidences were symptomatic VTE, 0.3%; incidental VTE requiring treatment, 1.1%; composite VTE, 1.4%; bleeding, 1.6%; cerebral infarction/transient ischemic attack/systemic embolic events, 0.7%; and all-cause death, 15.0%. The incidence of all-cause death was higher in patients with VTE vs without VTE at baseline (adjusted hazard ratio 1.67; 95% confidence interval 1.21-2.32; p = 0.002). CONCLUSIONS: VTE prevalence at the time of cancer diagnosis was not negligible and was extremely high when the patients had high D-dimer. VTE screening by D-dimer before starting cancer treatment is advisable, even for asymptomatic patients, regardless of whether the patient is undergoing surgery or chemotherapy. TRIAL REGISTRATION: UMIN000024942.

Surgery utilizing artificial intelligence technology: why we should not rule it out.

Recent advances in optical and robotic technologies have given surgeons high-definition eyes and precision hands that perform beyond human capabilities. This has expanded the scope of minimally invasive surgery and increased opportunities for surgery in high-risk situations; however, absolute surgical safety has not yet been achieved. Deficiencies in human performance are associated with surgical adverse events and advanced surgery places stress on surgeons and affect their concentration, causing not only novice surgeons with limited experience, but even skilled surgeons, to make misrecognition and decision-making errors. Therefore, the issue of "surgical comfort" for surgeons cannot be ignored. In recent years, artificial intelligence (AI), which is designed to mimic the function of the human brain, has been developed in various fields to assist humans. Computer vision, a visual assistive technology that uses AI, is being applied to surgery and will become available in the near future. AI-controlled robots cannot be expected to replace surgeons, because surgeons operate with higher brain functions that integrate all their abilities, including the senses of humanity, mission, and ethics. However, if there is a way to reduce the mental and physical burden on surgeons by utilizing AI technology, then it should not be ruled out.

Proposal for T3 classification of esophagogastric junction carcinoma based on the interconnection of extramural anatomical structures.

Classification of extramural invasion of esophagogastric junction carcinoma (EGJC) is not yet established. The anatomy surrounding the EGJ alters between the mediastinum and the abdominal cavity. This review proposed a T3 classification of EGJC based on anatomical continuity. Analysis of endoscopic ultrasound images, review of intraoperative images, and detailed observation of surgical specimens were followed by a review of the literature. In the EGJ, the muscularis propria of the esophagus is enclosed in mediastinal adipose tissue called the adventitia, which is surrounded by the diaphragmatic crus and contains the paraesophageal lymph nodes (LNs). After passing through the esophageal hiatus along with the vagus nerves and blood vessels, the adventitia joins the adipose tissue containing the paracardial LNs, which is covered by the peritoneum, and then further divides into the lesser and greater omentum. The connective tissue outside the muscularis propria of the stomach, including the adipose tissue of the omentum, is called the subserosa. According to the TNM classification, T3 esophageal and gastric cancer is defined as invasion of the adventitia and subserosa, respectively. Given that the adventitia is anatomically continuous with the subserosa, T3 tumors of the EGJ can be described as those that extend through the muscularis propria but do not invade the peritoneum or diaphragmatic crus. We propose classifying T3 EGJC as "tumor extends through muscularis propria" rather than using the separate terms "adventitia" and "submucosa". T4 could be "tumor perforates serosa or invades adjacent structures", as per the current gastric cancer classification.

Marked improvement of severe reflux esophagitis following proximal gastrectomy with esophagogastrostomy by the right gastroepiploic vessels-preserving antrectomy and Roux-en-Y biliary diversion.

Duodenogastroesophageal reflux (DGER) following esophagectomy or gastrectomy can cause severe esophagitis, which impairs patients' quality of life and increases the risk of esophageal carcinogenesis. It is sometimes resistant to medical treatment, and surgical treatment is considered effective in such cases. However, an optimal operative procedure for medical treatment-resistant reflux esophagitis (RE) after proximal gastrectomy (PG) with esophagogastrostomy (EG) has not yet been established. We performed the right gastroepiploic vessels-preserving antrectomy and Roux-en-Y biliary diversion in a 70-year-old man with medical treatment-resistant severe esophagitis caused by DGER following PG with EG for esophagogastric junction cancer. The postoperative course was uneventful, and esophagogastroduodenoscopy performed on the 19th postoperative day showed marked improvement in the esophageal erosions. The patient reported symptomatic relief. The right gastroepiploic vessels-preserving antrectomy and Roux-en-Y biliary diversion were considered safe and feasible for medical treatment-resistant RE following PG with EG.

Survival analysis of a prospective multicenter observational study on surgical palliation among patients with malignant bowel obstruction caused by peritoneal dissemination of gastric cancer.

BACKGROUND: Our previous report showed that surgical palliation maintained quality of life (QOL), improved solid food intake, and had an acceptable surgical safety among patients with malignant bowel obstruction (MBO) caused by advanced gastric cancer. This study performed a survival analysis stratified by the patients' QOL to elucidate its impact on survival. METHODS: Patients who underwent resection or bypass of the small intestine/colon or ileostomy/colostomy for bowel obstruction caused by peritoneal dissemination of gastric cancer were included. Validated instruments (EuroQoL-5 Dimensions) were used to assess QOL at baseline and 2 weeks, 1 month, and 3 months following surgical palliation. Postoperative improvement in oral intake was also evaluated using the Gastric Outlet Obstruction Scoring System (GOOSS). Univariate and multivariate survival analyses were performed using baseline characteristics and changes in QOL and GOOSS scores 2 weeks after surgery to determine prognostic factors. RESULTS: We enrolled 60 patients with a median survival time of 6.64 (95% CI 4.76-10.28) months. Patients who received postoperative chemotherapy and had lower baseline C-reactive protein (CRP) levels, higher baseline albumin levels, better baseline EuroQoL-5 Dimensions (EQ-5D) scores, and improved oral intake after palliative surgery exhibited significantly better survival. Multivariate analysis identified postoperative chemotherapy, lower baseline CRP levels, and improved oral intake as independent prognostic factors. CONCLUSIONS: The current study revealed that baseline QOL and postoperative QOL changes did not affect survival. Moreover, improved oral intake, lower baseline CRP levels, and postoperative chemotherapy were significant prognostic factors in patients who underwent palliative surgery for advanced gastric cancer with MBO.

Reducing the risk of postoperative pancreatic fistula in radical gastrectomy: pre-assessment with computed tomography for the diagnosis of pancreatic steatosis.

PURPOSE: To determine whether pancreatic steatosis (PS) is associated with the risk of postoperative pancreatic fistula (POPF) after radical gastrectomy, and if so, to investigate whether pre-assessment by diagnostic imaging can mitigate the risk. METHODS: The clinical records of 276 patients with cStage I gastric cancer who underwent laparoscopic gastrectomy with D1 + lymphadenectomy between 2012 and 2015 were reviewed. In the first phase up to July 2013 (n = 138), PS was classified from computed tomography (CT) findings into type S (superficial fat deposition) or type D (diffuse fatty replacement) and examined for association with POPF. In the second phase (n = 138), the preoperative CT assessment of PS was routinized. Separate samples from pancreatoduodenectomy consistent with each type were histologically examined. RESULTS: In the first phase, the incidence of POPF was significantly higher in group S, but not in group D, compared with normal pancreas (16.3% and 9.1% vs. 3.6%, respectively; P = 0.03). The drain amylase level was lowest in group D, reflecting exocrine insufficiency. Histologically, the loose connective-tissue space between the fat infiltrating the pancreas and the peripancreatic fat containing the lymph nodes was unclear in type D but conserved in type S. In the second phase, surgery was performed with more intention on accurately tracing the dissection plane and significantly lowered incidence of POPF in Group S (16.3% to 2.1%; P = 0.047). CONCLUSION: Peripancreatic lymphadenectomy is more challenging and likely to cause POPF in patients with PS. However, the risk may be reduced using appropriate dissection techniques based on the CT pre-assessment findings.

History of the lymph node numbering system in the Japanese Classification of Gastric Carcinoma since 1962.

The Japanese Classification of Gastric Carcinoma was established by the Japanese Research Society for Gastric Cancer in 1962. The latest 15th edition was published in 2017. One of its main features is that lymph nodes are numbered as stations. The number of groups has increased from 16 to 36 in 55 years. Seven groups (nos. 1, 2, 5, 7, 9, 10, and 15) were retained from the original classification. Nine groups (nos. 3, 4, 6, 8, 11, 12, 13, 14, and 16) were sub-divided into two or more groups. Furthermore, seven groups (nos. 17, 18, 19, 20, 110, 111, and 112) were added in the 6th, 11th, and 12th editions. This numbering system helps surgeons recognize the exact lymph nodes that need to be dissected. However, the numbering system has become extremely complicated. It is necessary to organize the historical background of each lymph node station and share the definitions clearly. This review focuses on nine anatomical zones around the stomach and summarizes the history of lymph node stations in the Japanese Classification of Gastric Carcinoma. Lymph node stations will continue to be modified in the future, and the historical background may be useful in future revisions.

Sunitinib and Pterostilbene Combination Treatment Exerts Antitumor Effects in Gastric Cancer via Suppression of PDZD8.

The use of molecular-targeted drugs in the treatment of gastric cancer is increasing. However, the variety of molecular-targeted drugs in gastric cancer is still limited, and the development of new molecular-targeted therapies is required. The effect of combining sunitinib (SUN) with pterostilbene (PTE) on the human gastric cancer cell lines TMK1 and MKN74 was examined in in vitro and in vivo. Compared with SUN or PTE treatment alone, cotreatment induced pronounced suppression of cell proliferation, with a marked increase in oxidative stress. SUN was associated with a significant retention of mitochondrial Fe2+. SUN-treated cells decreased expression of PDZ domain-containing protein 8 (PDZD8). Knockdown of PDZD8 in both cells induced Fe2+ retention, and siPDZD8+PTE markedly suppressed cell proliferation with suppressed oxidative phosphorylation, as did the combination of SUN+PTE. In a nude mouse tumor model, a pronounced antitumor effect was observed with SUN+PTE treatment compared to SUN alone. PDZD8 may be a newly discovered off-target for SUN, and that the combined use of PTE with SUN significantly promotes antitumor activity in gastric cancer cell lines. The combined use of SUN and PTE might be a new molecular-targeted therapy for gastric cancer.

Gastric equivalent of the 'Holy Plane' to standardize the surgical concept of stomach cancer to mesogastric excision: updating Jamieson and Dobson's historic schema.

BACKGROUND: Surgery for curable gastric cancer has historically involved dissection of lymph nodes, depending on the risk of metastasis. By establishing the concept of mesogastric excision (MGE), we aim to make this approach compatible with that for colorectal cancer, where the standard is excision of the mesentery. METHODS: Current advances in molecular embryology, visceral anatomy, and surgical techniques were integrated to update Jamieson and Dobson's schema, a historical reference for the mesogastrium. RESULTS: The mesogastrium develops with a three-dimensional movement, involving multiple fusions with surrounding structures (retroperitoneum or other mesenteries) and imbedding parenchymal organs (pancreas, liver, and spleen) that grow within the mesentery. Meanwhile, the fusion fascia and the investing fascia interface with adjacent structures of different embryological origin, which we consider to be equivalent to the 'Holy Plane' in rectal surgery emphasized by Heald in the concept of total mesorectal excision. Dissecting these fasciae allows for oncologic MGE, consisting of removing lymph node-containing mesenteric adipose tissue with an intact fascial package. MGE is theoretically compatible with its colorectal counterpart, although complete removal of the mesogastrium is not possible due to the need to spare imbedded vital organs. The celiac axis is treated as the central artery of the mesogastrium, but is peripherally ligated by tributaries flowing into the stomach to feed the spared organs. CONCLUSION: The obscure contour of the mesogastrium can be clarified by thinking of it as the gastric equivalent of the 'Holy Plane'. MGE could be a standard concept for surgical treatment of stomach cancer.

QOL assessment after palliative surgery for malignant bowel obstruction caused by peritoneal dissemination of gastric cancer: a prospective multicenter observational study.

BACKGROUND: Patients with peritoneal dissemination of gastric cancer have poor oral intake caused by malignant bowel obstruction (MBO). Palliative surgery has often been undertaken to improve quality of life (QOL), but few prospective studies on palliative surgery in this patient population have been published. PATIENTS AND METHODS: We prospectively investigated the significance of palliative surgery using patient-reported QOL measures. Patients underwent palliative surgery by small intestine/colon resection or small intestine/colon bypass or ileostomy/colostomy for MBO. The primary endpoint was change in QOL assessed at baseline, 14 days, 1 month, and 3 months following palliative surgery using the Euro QoL Five Dimensions (EQ-5D™) questionnaire and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire gastric cancer module (QLQ-STO22). Secondary endpoints were postoperative improvement in oral intake and surgical complications. RESULTS: Between April 2013 and March 2018, 63 patients were enrolled from 14 institutions. The mean EQ-5D™ utility index baseline score of 0.6 remained consistent. Gastric-specific symptoms mostly showed statistically significant improvement from baseline. Forty-two patients (67%) were able to eat solid food 2 weeks after palliative surgery and 36 patients (57%) tolerated it for 3 months. The rate of overall morbidity of ≥ grade III according to the Clavien-Dindo classification was 16% (10 patients) and the 30-day postoperative mortality rate was 3.2% (2 patients). CONCLUSIONS: In patients with MBO caused by peritoneal dissemination of gastric cancer, palliative surgery did not improve QOL while improving solid food intake, with an acceptable postoperative morbidity and mortality rate.

Anastomosis behind the sternoclavicular joint is associated with increased incidence of anastomotic stenosis in retrosternal reconstruction with a gastric conduit after esophagectomy.

Anastomotic stenosis after esophagectomy is a major cause of long-term morbidity because it leads to poor dietary intake and malnutrition that markedly reduces the quality of life. The aim of this study was to test the hypothesis that anastomosis behind the sternoclavicular (SC) joint in retrosternal reconstruction is associated with an increased risk of anastomotic stenosis compared with anastomosis deviated from the joint. Among 226 patients who underwent esophagectomy for esophageal cancer between April 2010 and March 2019, we selected 114 patients who underwent retrosternal reconstruction using a gastric conduit for this study. They were classified into two groups according to the location of the anastomosis as determined by axial sections on postoperative computed tomography scans: anastomosis located behind the SC joint (Group B; n = 71) and anastomosis deviated from the joint (Group D; n = 43). The primary endpoint was the difference in the incidence of anastomotic stenosis between the two groups. Whether the occurrence of anastomotic leak affected the likelihood of anastomotic stenosis was also investigated. The incidence of anastomotic stenosis was significantly higher in Group B than in Group D (71.8% [n = 51] vs. 18.6% [n = 8]; P < 0.0001). The incidence of stenosis in patients who developed an anastomotic leak was significantly higher in Group B than in Group D (88.0% vs. 41.7%; P = 0.0057), although the findings were similar in patients who did not develop anastomotic leak (63.0% and 9.7%, respectively; P < 0.0001). We conclude that anastomosis located behind the SC joint in retrosternal reconstruction with a gastric conduit after esophagectomy is associated with an increased risk of anastomotic stenosis regardless of the development of anastomotic leak.

A case of ectopic pancreas of the stomach accompanied by intraductal papillary mucinous neoplasm with GNAS mutation.

BACKGROUND: Ectopic pancreas is basically a benign disease and is not always necessary to be removed. However, all types of neoplasms occurring in the normal pancreas such as ductal adenocarcinomas and intraductal papillary mucinous neoplasms (IPMNs) may develop even within ectopic pancreas. We recently encountered an extremely rare case of ectopic pancreas in the gastric antrum associated with IPMN possessing a GNAS mutation. CASE PRESENTATION: A 71-year-old Japanese woman complained of epigastric pain. Computed tomography and upper gastrointestinal endoscopy showed an intramural cystic mass in the antrum of the stomach. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy did not give a definitive diagnosis, and the patient underwent resection of the lesion. Histology of the resected specimen showed that the gastric intramural lesion was ectopic pancreas. Moreover, the lesion contained dilated duct components with tubulo-villous epithelial proliferation consistent with pancreatic IPMN. Since the covering epithelial cells had highly atypical nuclei, the lesion was diagnosed as IPMN with high grade dysplasia. Immunohistochemistry showed that the IPMN component showed to be MUC2-, MUC5AC-, and CDX2-positive but MUC1- and MUC6-negative. Mutational analyses using genomic DNA revealed that the IPMN component had a mutation of GNAS at exon 8 (Arg201Cys). CONCLUSION: We finally diagnosed this case as gastric ectopic pancreas accompanied by intestinal type IPMN with high grade dysplasia possessing GNAS mutation. Although there were 17 cases of ectopic pancreas with IPMN including 6 cases of gastric ones reported in the English literature, this is the first case of ectopic pancreas with IPMN which was proved to have GNAS mutation. Intimate preoperative examinations including imaging analyses and EUS-FNA biopsy/cytology are recommended to decide whether the lesion has to be resected or not even if they are not effective for getting the right diagnosis.

Laparoscopic Suprapancreatic Lymph Node Dissection Using a Systematic Mesogastric Excision Concept for Gastric Cancer.

BACKGROUND: Gastrointestinal cancer surgery requires en bloc removal of the primary tumor and organ-specific mesentery1,2. However, this surgical concept for gastric cancer has not yet been applied because of the morphological complexity of the mesenteries of the stomach. Lymph node dissection in gastric cancer surgery can be roughly performed into three regions: lesser curvature, grater curvature, and suprapancreatic region. In this video, we introduced laparoscopic lymphadenectomy in the suprapancreatic region using a systematic mesogastric excision (SME), which has been reported as a concept to perform en bloc resection3. METHODS: This procedure was divided into three steps. First, mesenterization of the mesogastrium was performed by dissecting the embryological planes, and the mesogastrium was dissected from the retroperitoneal surface (Fig. 1a). Second, soft tissue, including the lymph node, was separated from the pancreas and the splenic artery by tracing the inner dissectable layer (Fig. 1b). Finally, the tumor-specific mesentery was transected according to the extent of the lymphadenectomy (Fig. 1c).Fig. 1Intraoperative findings during the stepwise procedure in dissecting the lymph node in the suprapancreatic region. The red broken line indicates the surgical outline. a The mesogastrium is dissected from the retroperitoneal tissue. b The mesogastrium is separated from the pancreas and splenic artery. c The mesogastric transection line is determined on the basis of the extent of the lymphadenectomy. Inf. phrenic a. inferior phrenic artery; PGA posterior gastric artery; Post. epiploic a. posterior epiploic artery; RV renal vein; SA splenic artery; SV splenic vein RESULTS: Between January 2017 and December 2017, six patients underwent laparoscopic distal gastrectomy with D2 lymphadenectomy using SME. The median time required to complete the suprapancreatic lymphadenectomy was 48 min. No patient underwent conversion to open surgery or experienced intraoperative complications. CONCLUSIONS: We believe that this laparoscopic suprapancreatic lymphadenectomy using SME takes advantage of the surgical anatomy and achieves en bloc removal of the primary tumor and gastric mesentery. This series is a proof of concept that this procedure can be performed in a timely manner and is feasible.

Three-dimensional morphogenesis of the omental bursa from four recesses in staged human embryos.

The omental bursa (OB) is a complex upper abdominal structure in adults. Its morphological complexity stems from embryonic development. Approximately 200 years ago, the first theory regarding OB development was reported, describing that the OB developed from changes in the position of the stomach and its dorsal mesentery. Thereafter, the second theory reported that the OB originated from three recesses: the right pneumato-enteric recess (rPER), hepato-enteric recess (HER), and pancreatico-enteric recess (PaER). However, the first theory, focusing on the rotation of the stomach, is still described in certain modern embryology textbooks. These two coexisting embryological theories deter the understanding of the anatomical complexity of the OB. This study aimed to unify these two theories into realistic illustrations. Approximately 10 samples per stage among Carnegie stage (CS) 13 and CS21 were microscopically observed and histological serial sections of the representative samples were aligned using the new automatic alignment method. The aligned images were segmented computationally and reconstructed into 3D models. The rPER and the HER encompassed the right half circumference of the esophagus and the stomach at CS13 and CS14, the PaER spread dorsal to the stomach and formed a discoid shape at CS15 and CS16, the infracardiac bursa (ICB) was separated by the diaphragm at CS17 and CS18, and the fourth recess, which we called the greater omental recess (GOR), extended caudally from the PaER among CS19 and CS21. The present results indicate that the fourth recess is also the origin of the OB. These two theories over 200 years can be generally unified into one embryological description indicating a new recess as the origin of the OB.

Mesenteric excision of upper esophagus: a concept for rational anatomical lymphadenectomy of the recurrent laryngeal nodes in thoracoscopic esophagectomy.

BACKGROUND: The recurrent laryngeal nerve (RLN) lymph nodes are among the most frequently involved lymph nodes in esophageal cancer. Surgical removal of these lymph nodes is considered beneficial for postoperative prognosis, especially in patients with squamous cell carcinoma. Unfortunately, the precise surgical anatomy of the upper mediastinum is not well understood and no distinct high-resolution images are currently available. METHODS: In this article, we provide a simple intuitive concept of upper mediastinal surgical anatomy that could facilitate rational anatomical lymphadenectomy of the RLN lymph nodes. The essential concept of this mesenteric excision is to mobilize mesoesophagus including RLN in an en bloc fashion and to save RLN laterally by incising visceral sheath. This is applicable identically to both right and left upper mediastinum. RESULTS: Between January 2009 and December 2017, thoracoscopic esophagectomy with upper mediastinal lymphadenectomy for primary esophageal cancer was performed in 189 patients. Median thoracoscopic procedure time was 297 (range 205-568) min and median intraoperative blood loss was 70 ml (range unmeasurable up to 2545 ml). Median number of harvested upper mediastinal lymph nodes was 12. Postoperative complication of Clavien-Dindo classification grade III or higher events was observed in 14% of patients. RLN palsy of grade II or higher occurred in 20 patients (11%). CONCLUSION: The mesoesophagus in the upper mediastinum is an anatomical unit surrounded by fibrous connective tissue containing the esophagus, trachea, tracheoesophageal vessels, lymphatic tissue, and RLNs. Thus, mesenteric excision of esophagus is defined to resect this area by sparing trachea and RLNs for rational anatomical lymphadenectomy. We believe that this concept makes upper mediastinal lymphadenectomy safer and more appropriate.

Improvement in Hyperglycemia Prevents Surgical Site Infection Irrespective of Insulin Therapy in Non-diabetic Patients Undergoing Gastrointestinal Surgery.

BACKGROUND: Intensive glycemic control is recommended to prevent surgical site infections (SSI). Our aim was to evaluate retrospectively the effect of improvement in hyperglycemia irrespective of insulin use on the incidence of SSI in non-diabetic patients. METHODS: The highest blood glucose (BG) concentration within 12 h (early peak BG) and the final BG from 12 to 24 h after surgery were evaluated in patients who underwent gastrointestinal surgery. Patients with an early peak BG of ≥150 mg/dL were divided into those with persistent (final BG of ≥150 mg/dL) and improved hyperglycemia (final BG of <150 mg/dL). Patients without hyperglycemia and those with late-onset hyperglycemia were also assessed for SSI risk. RESULTS: Overall, 1612 patients were studied (diabetes, n = 293). Although hyperglycemia increased the SSI rates in non-diabetic patients, no correlation was demonstrated in patients with diabetes at any cutoff final BG defining htperglycemia except for 180 mg/dL. Hyperglycemia improved without insulin therapy in 283 of 512 non-diabetic patients who had early hyperglycemia. The adjusted standardized residual for those with SSI and persistent hyperglycemia was 5.2 (P < 0.05). In contrast, the absence of hyperglycemia was a significant preventive factor for SSI. In the multivariate analyses, persistent hyperglycemia was an independent risk factor for SSI (odds ratio 1.54; 95% confidence interval 1.03-2.31). CONCLUSIONS: Remission of hyperglycemia within 24 h after surgery prevented SSI in non-diabetic patients. Considering that hyperglycemia improved in approximately half of patients without insulin therapy, commencement of insulin dosing after two consecutive BGs of ≥150 mg/dL might be reasonable, especially in general wards.

True esophagogastric junction adenocarcinoma: background of its definition and current surgical trends.

The definition of true esophagogastric junction (EGJ) adenocarcinoma and its surgical treatment are debatable. We review the basis for the current definition and the Japanese surgical strategy in managing true EGJ adenocarcinoma. The Siewert classification is a well-known anatomical classification system for EGJ adenocarcinomas: type II tumors in the region 1 cm above and 2 cm below the EGJ are described as "true carcinoma of the cardia". Coincidentally, this range matches gastric cardiac gland distribution. Conversely, Nishi's classification is generally used to describe EGJ carcinomas, defined as tumors with the center located within 2 cm above and 2 cm below the EGJ, regardless of their histological subtype. This range coincides with the extent of the lower esophageal sphincter combined with gastric cardiac gland distribution. The current Japanese surgical strategy focuses on the tumor range from the EGJ to the esophagus and stomach. According to previous studies, the strategy can be roughly classified into three types. The optimal surgical procedure for true EGJ adenocarcinoma is controversial. However, an ongoing Japanese nationwide prospective trial will help confirm the appropriate standard surgery, including the optimal extent of lymph node dissection.