Yoshihide Nanno

Second primary pancreatic ductal carcinoma in the remnant pancreas after pancreatectomy for pancreatic ductal carcinoma: High cumulative incidence rates at 5 years after pancreatectomy

OBJECTIVES The aim of this study was to determine the incidence rate and clinical features of second primary pancreatic ductal carcinoma (SPPDC) in the remnant pancreas after pancreatectomy for pancreatic ductal carcinoma (PDC). METHODS Data of patients undergoing R0 resection for PDC at a single high-volume center were reviewed. SPPDC was defined as a tumor in the remnant pancreas after R0 resection for PDC, and SPPDC met at least one of the following conditions: 1) the time interval between initial pancreatectomy and development of a new tumor was 3 years or more; 2) the new tumor was not located in contact with the pancreatic stump. We investigated the clinical features and treatment outcomes of patients with SPPDC. RESULTS This study included 130 patients who underwent surgical resection for PDC between 2005 and 2014. Six (4.6%) patients developed SPPDC. The cumulative 3- and 5-year incidence rates were 3.1% and 17.7%, respectively. Four patients underwent remnant pancreatectomy for SPPDC. They were diagnosed with the disease in stage IIA or higher and developed recurrence within 6 months after remnant pancreatectomy. One patient received carbon ion radiotherapy and survived 45 months. One patient refused treatment and died 19 months after the diagnosis of SPPDC. CONCLUSIONS The incidence rate of SPPDC is not negligible, and the cumulative 5-year incidence rate of SPPDC is markedly high. Post-operative surveillance of the remnant pancreas is critical for the early detection of SPPDC, even in long-term survivors after PDC resection.

CD133 expression in well-differentiated pancreatic neuroendocrine tumors: a potential predictor of progressive clinical courses

The present study aimed to elucidate whether the stemness molecule, CD133, is expressed in well-differentiated pancreatic neuroendocrine tumors (PanNETs; World Health Organization grades 1 and 2) and establish its clinical relevance using 2 separate cohorts. In the first series (n = 178) in which tissue microarrays were available, immunohistochemistry revealed that CD133 was expressed in 14 cases (8%). CD133+ PanNETs had higher TNM stages (P < .01), more frequent lymphovascular invasion (P = .01), and higher recurrence rates (P = .01). In the second cohort (n = 56), the expression of CD133 and CK19 was examined in whole tissue sections. CD133 and CK19 were positive in 10 (18%) and 36 (64%) cases, respectively. CD133 expression correlated with higher pT scores (P < .01), the presence of microscopic venous infiltration (P = .03), and shorter disease-free periods (P < .01). When cases were divided into grade 1 and 2 neoplasms, patients with CD133+ PanNET continued to have shorter disease-free periods than did those with CD133- tumors in both groups (P < .01 and P = .02, respectively). Although CK19+ cases had shorter disease-free periods than did CK19- cases in the whole cohort (P = .02), this difference was less apparent in subanalyses of grade 1 and 2 cases. CD133 expression also appeared to be an independent predictive factor for tumor recurrence in a multivariate analysis (P = .018). The CD133 phenotype was identical between primary and metastatic foci in 17 of 18 cases from which tissues of metastatic deposits were available. In conclusion, the combination of CD133 phenotyping and World Health Organization grading may assist in stratifying patients in terms of the risk of progressive clinical courses.

Preoperative Oral Branched-Chain Amino Acid Supplementation Suppresses Intraoperative and Postoperative Blood Lactate Levels in Patients Undergoing Major Hepatectomy

BACKGROUND Lactate production is exacerbated by surgical stress. We sought to determine whether branched-chain amino acid (BCAA) supplementation could decrease blood lactate levels in patients undergoing hepatectomy. METHODS A total of 275 consecutive patients who underwent hepatectomy of ≥2 segments were retrospectively reviewed. Blood lactate levels in patients treated with BCAA supplementation before hepatectomy (December 2011 to December 2016) were compared with levels in patients who were not pretreated (January 2008 to November 2011). RESULTS Postoperative lactate levels were significantly lower in patients who received preoperative BCAA supplementation than in those who did not (2.6 vs 3.4 mmol/L; P < .001). Intraoperative blood lactate levels, which were evaluated after induction of general anesthesia, were also lower in those who received BCAA supplementation than in those who did not (1.1 vs 1.5 mmol/L, respectively; P < .001). A multiple regression analysis revealed that preoperative BCAA supplementation was independently associated with decreased postoperative and intraoperative lactate levels (P = .030 and P < .001, respectively). CONCLUSION Preoperative BCAA supplementation decreased intraoperative and postoperative blood lactate levels in patients undergoing major hepatectomy.

ASO Author Reflections: Serum Elastase 1 Level as a Risk Factor for Postoperative Recurrence in Patients with Well-Differentiated Pancreatic Neuroendocrine Neoplasms

Well-differentiated pancreatic neuroendocrine neoplasms (PanNETs) are heterogeneous in terms of pathology and biology, and their clinical course varies widely. Complete resection is the cornerstone of clinical management of patients with PanNETs; however, prediction of recurrence after complete resection is still difficult. One of the most widely accepted prognostic factors is the World Health Organization (WHO) histological grading scheme; however, tissue sampling is necessary for this grading, and accurate preoperative assessment of malignancy risk is generally difficult. Preoperative imaging findings have also been used for assessment of malignancy risks; however, they are still incomplete to determine aggressive clinical behavior in terms of simplicity or objectivity. Alternative strategies for risk classification in the clinical setting are needed.

Effect of Oral Branched-Chain Amino Acid Supplementation on Postoperative Blood Lactate Levels in Patients Undergoing Pancreatoduodenectomy

BACKGROUND Elevations in blood lactate levels have been associated with poor postoperative outcome. The aim of the present study was to determine if preoperative supplementation with branched-chain amino acids (BCAA) decreases postoperative blood lactate levels in patients undergoing pancreatoduodenectomy. METHODS The cases of 223 consecutive patients who underwent pancreatoduodenectomy were retrospectively reviewed. Postoperative blood lactate levels in patients who were treated with BCAA supplementation before pancreatoduodenectomy (December 2011-December 2014) were compared with levels in patients who were not pretreated (January 2008-November 2011). RESULTS Postoperative lactate levels were significantly lower in patients who received preoperative BCAA supplementation than in patients who did not (2.6 vs 3.1 mmol/L, P = .005), although preoperative blood lactate levels were statistically equivalent between the groups. In the univariate analysis, preoperative BCAA supplementation, preoperative lactate levels, operation time, and postoperative glucose levels were associated with postoperative lactate levels. A multiple regression analysis was performed among the 4 factors, and the preoperative use of BCAA supplementation was independently correlated with postoperative lactate levels ( P = .046). CONCLUSIONS Preoperative BCAA supplementation decreased postoperative blood lactate levels. These results suggest that preoperative BCAA supplementation may help patients recover after surgery.

Internal hernia through a transverse mesocolon defect after laparoscopic distal pancreatectomy: Report of a case

We report a case of an internal hernia through a transverse mesocolon defect after laparoscopic distal pancreatectomy. The patient was a 58‐year‐old man with an intraductal papillary mucinous neoplasm of the pancreatic body who underwent laparoscopic distal pancreatectomy. During surgery, an approximately 5‐cm defect in the transverse mesocolon was inadvertently made. The defect was not closed as it was thought to be large enough to preclude incarceration. However, the patient developed a bowel obstruction 2 months postoperatively. Laparotomy revealed that a loop of the proximal jejunum herniated through the defect and was adherent to the stapled pancreatic stump. An additional loop of the jejunum was herniated through the narrowed mesenteric defect. To our knowledge, this is the first case of an internal hernia through a transverse mesocolon defect after laparoscopic distal pancreatectomy.

Case of intra‐abdominal spindle cell tumor after laparoscopic resection of sigmoid colon cancer

We herein report a rare case of a patient who developed a spindle cell tumor at the inferior mesenteric artery clipping site. A 58‐year‐old man underwent laparoscopy‐assisted sigmoid colectomy for sigmoid colon cancer. As follow‐up, CT scans were performed every 6 months after the primary surgery. At the 1‐year CT, an nodular soft tissue density mass measuring 54 mm in diameter was found in the mesentery. Although we initially suspected locoregional recurrence of the colon cancer resected 1 year earlier, PET‐CT showed that the tumor was unrelated to the previous cancer. During the subsequent laparotomy, the mass appeared to originate from the inferior mesenteric artery clipping site, and it adhered to the jejunum and the left ureter. We completely resected the tumor and part of the jejunum, which we separated from the abdominal aorta and left ureter. The tumor was histologically diagnosed of a spindle cell tumor. The patient has been free from recurrence since the surgery more than 4.5 years ago. Preoperative PET‐CT was helpful in ruling out local recurrence of colon cancer, which might have made palliative care a better option than surgical resection.