Yasunori Kurahashi

Topographic anatomy and laparoscopic technique for dissection of no. 6 infrapyloric lymph nodes in gastric cancer surgery

We focused on the embryology and topographic anatomy of the infrapyloric lymph region, which is frequently involved in node metastases but technically complicated for dissection in gastric cancer surgery. Gastrointestinal organs possess their own mesenteries composed of double layers of peritoneum that enclose the intermediate adipose layer providing pathways for vessels, nerves, and lymphatic channels. The frontal layer of the mesoduodenum, in which no. 6 infrapyloric nodes lie, directly faces the pancreas and during gestation is overlain by the greater omentum and transverse mesocolon through the membranous connective tissue called the fusion fascia. Therefore, we performed no. 6 node dissection using the following process: (1) we traced out the mesoduodenum by detachment of the greater omentum and transverse mesocolon; (2) we transected the fusion fascia and (3) removed the adipose layer on the anterior face of the pancreas with its included lymph nodes together with the right gastroepiploic and infrapyloric vessels. The described technique is feasible and in keeping with the anatomical logic for oncologically reliable dissection of no. 6 infrapyloric nodes.

Tumor response to neoadjuvant chemotherapy in patients with esophageal cancer assessed with CT and FDG-PET/CT – RECIST 1.1 vs. PERCIST 1.0

PURPOSE We compared the response classification systems Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) 1.0 for assessment of response to neoadjuvant chemotherapy in patients with esophageal cancer. MATERIALS AND METHODS Prior to planned surgical resection, 62 patients with esophageal cancer underwent fluorodeoxyglucose (FDG)-PET/CT and contrast-enhanced CT examinations before and after receiving neoadjuvant chemotherapy. Primary tumor largest diameter, maximum standardized uptake value (SUVmax), peak lean body mass SUV (SULpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were determined. Patients were divided into responders (grade 1b-3) and non-responders (grade 0-1a) according to pathological response. RESULTS Concordance between RECIST 1.1 and PERCIST 1.0 for response classification was seen in 28 (45.2%) patients. For 18 defined as responders, the number of metabolic responders (partial metabolic response + complete metabolic response) shown by PERCIST 1.0 was 17 and the number of anatomic responders (partial response + complete response) shown by RECIST 1.1 was 13. To distinguish responders from non-responders, the area under the receiver operating characteristics curve values for reduced primary tumor largest diameter, SUVmax, SULpeak, MTV, and TLG were 0.724, 0.775, 0.781, 0.756, and 0.759, respectively. An optimal percent decrease in largest diameter cut-off value of 39.2% was found to have 66.7% sensitivity and 70.5% specificity, while that for SULpeak of 55.8% was 77.8% and 75.0%, respectively. CONCLUSIONS As compared to RECIST 1.1, PERSIST 1.0 may be more suitable for evaluation of neoadjuvant therapeutic response to esophageal cancer.

Universalization of the operative strategy by systematic mesogastric excision for stomach cancer with that for total mesorectal excision and complete mesocolic excision colorectal counterparts

Gastrointestinal cancer surgery aims at en bloc removal of the primary tumor with its lymphatic drainage by excising organ‐specific mesentery as an “intact package”. This concept was advocated in colorectal cancer surgery as total mesorectal excision (TME) or complete mesocolic excision (CME) procedures, but is not directly applicable to stomach cancer as a result of the morphological complexities of the gastric mesentery. In this review, we discuss the unique anatomical features of the mesogastrium by introducing its embryology, disclose its similarity to the mesosigmoid, and then propose a theoretical concept to mesentery‐based D2 gastrectomy, namely systematic mesogastric excision, which can universalize the operative strategy of stomach cancer with that of TME and CME colorectal counterparts.

The eCura system as a novel indicator for the necessity of salvage surgery after non-curative ESD for gastric cancer: A case-control study

Endoscopic submucosal dissection (ESD) for early gastric cancer does not always lead to complete cancer resection. The aim of this study was to determine indicators for cancer residue (CR) status in cases of non-curative ESD. We analyzed 47 cases of non-curative ESD followed by salvage surgery and collected data regarding the rates of CR, which included both local CR and lymph node metastasis (LNM). To elucidate the risk factors for CR status, we compared the CR positive and the CR negative groups among surgical specimens according to the following variables obtained from ESD findings: tumor location, tumor size, depth of invasion, lympho-vascular invasion, histological margin, and histological diagnosis. The eCura system, which is an LNM risk scoring system, was also applied and scores were calculated in each case as follows: 3 points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. There were 9 (19%) CR positive cases, which included 6 cases of local CR and 4 cases of LNM; no cancer was detected in over 80% of the patients. The eCura scoring system was the only significant factor for CR status: the higher the eCura score, the greater the CR positivity (p = 0.0128). In particular, all patients in the low-risk group (score = 0–1 point) had no CR. Although no cancer recurrence was observed during a median follow-up of 4 years, 2 patients died of pneumonia. In conclusion, the eCura system might make it possible to select appropriate cases for salvage surgery.