Masaaki Mitsutsuji

Ultrastructural analyses of pancreatic grafts preserved by the two-layer cold-storage method and by simple cold storage in University of Wisconsin solution

Abstract The two‐layer cold storage method (TLM) using University of Wisconsin (UW) solution supplies sufficient oxygen to pancreatic grafts during preservation and extends pancreas preservation time to up to 96h in the canine model. Simple cold storage in UW (UWM) on the other hand, preserves canine pancreas grafts for up to 72h by preventing cell swelling, mainly because of its high osmotic pressure. The aim of this study is to analyze morphologically dog pancreatic grafts preserved by these two methods with their different mechanisms. Immediately after preservation of canine pancreata by TLM for 72h and 96h (group 1 and group 3, respectively), and by UWM for 72h and 96h (group 2 and group 4, respectively), tissue ATP levels were determined using high‐performance liquid chromatography (HPLC), and detailed morphological analyses of intragraft components were performed using light‐ and electron microscopy. The mean areas of one mitochondrion and rough endoplasmic reticulum (PER) vacuolization were calculated by computer‐graphic analyses using NIH image 1.62f soft. The tissue ATP levels were significantly higher in groups 1 and 3 than groups 2 and 4 (P<0.05). Light microscopy demonstrated no marked difference among the 4 groups. By electron microscopy however, mitochondrial swelling and RER vacuolization were observed in acinar cells to various extents in the 4 groups. They were significantly more evident in group 2 than group 1 (P<0.05), and in group 4 than group 3 (P<0.05). In conclusion, TLM demonstrated excellent protection of intracellular organelles, mitochondria, and RER, up to 72–96h. Well‐maintained graft ATP levels in TLM groups may result in maintaining the integrity of intracellular organelle membranes as well as cellular membranes.

Cranial-to-caudal approach for radical lymph node dissection along the surgical trunk in laparoscopic right hemicolectomy

Complete mesocolic excision with central vascular ligation is considered to contribute to superior oncological outcomes after colon cancer surgery [1]. For advanced right-sided colon cancer, this surgery sometimes requires lymph node (LN) dissection along the superior mesenteric vein (SMV), with division of the middle colic vessels, or their right branches, at origin [2]. Here, we present cranially approached radical LN dissection along the surgical trunk during laparoscopic right hemicolectomy. The omental bursa is first opened wide, and the gastrocolic trunk of Henle is exposed, using the right gastroepiploic vessels and the accessory right colic vein (ARCV) as landmarks. After division of ARCV, SMV and middle colic vein (MCV) are identified. After dividing MCV at its root, LN dissection along SMV is conducted in a cranial-to-caudal manner. Concurrently, the middle colic artery, or its right branch, is exposed and divided at origin. The transverse colon is then raised ventrally, and LN dissection along SMV using a cranial-to-caudal approach is again performed. The ileocolic and right colic vessels are divided at origin. The ascending and transverse mesocolon, including the pedicles, are then separated from the retroperitoneal tissues, pancreatic head, and duodenum, using a medial approach. The key characteristics in this procedure consist of easy access to pancreas, early division of ARCV and middle colic vessels at origin, and easy dissection along SMV. We performed a laparoscopic colectomy using this approach for 18 patients with right-sided colon cancer. The mean operative time and blood loss were 288 min and 83 ml, respectively. The mean number of harvested LNs was 24. There were 6 cases with positive LN metastasis. There were no recurrent cases at a median follow-up period of 24 months. We consider this approach to be safe and useful for radical LN dissection along SMV for right-sided colon cancers.

Surgical outcomes of intracorporeal circular-stapled esophagojejunostomy using modified over-and-over suture technique in laparoscopic total gastrectomy

AbstractBackground Esophagojejunostomy in laparoscopic total gastrectomy (LTG) is a technically demanding procedure. Although several methods have been reported to date, none is considered consistently reliable. We developed a simple method for intracorporeal circular-stapled esophagojejunostomy using a modified over-and-over suture technique. The surgical outcomes of our technique were evaluated in comparison with those of open total gastrectomy (OTG).MethodsFrom April 2012 to August 2014, reconstruction using this method in LTG was performed for 21 consecutive patients with gastric cancer (LTG group). Their surgical outcomes were compared with those of 27 patients with gastric cancer who underwent OTG without splenectomy (OTG group) between January 2011 and April 2014.ResultsEstimated blood loss was significantly lower, and the postoperative hospital stay was significantly shorter in the LTG group than in the OTG group. The operating time and the number of harvested lymph nodes were similar between the two groups. The incidence of overall complications did not differ significantly between the two groups. Anastomotic leakage developed in one of the 21 patients in the LTG group and in two of the 27 patients in the OTG group. Anastomotic stenosis was observed in one patient in the LTG group.ConclusionsWe consider this method as simple and feasible for most laparoscopic surgeons with basic laparoscopic suturing skills. This method might help LTG to become an accepted standard surgical option for treatment of patients with gastric cancer.

An Experimental Study on the Pharmacokinetics of 5-Fluorouracil Regional Chemotherapy for Pancreatic Cancer

Background: Recently a few centers reported promising results of regional intra-arterial chemotherapy for pancreatic cancer. However, the detailed pharmacokinetics and the side effects of anticancer agents remain unclear.Methods: Catheters were introduced into the gastroduodenal artery and the splenic artery of dogs. In group I, arterial infusion of 5-fluorouracil (5-FU) was performed over 10 minutes. In group II, 5-FU was infused systemically. In group III, an intra-arterial infusion was repeated weekly three times. Blood samples and liver and pancreas tissue samples were obtained to determine 5-FU levels. In a subset of each group, the pancreas, duodenum, and liver were excised for histological analyses.Results: Immediately after the infusion of 5-FU, the portal level in group I was higher than that in group II. However, the mean systemic level in group I was lower than in group II. The mean tissue concentration in the pancreas in group I was significantly higher than that of group II. Histological examination revealed no microscopic alterations after treatment in all groups, including group III.Conclusions: This fundamental study suggested that intra-arterial chemotherapy of 5-FU for pancreatic cancer allows higher regional drug delivery without adverse effects on normal regions of the pancreas, the duodenum, and the liver.

Superiority of Mild Hypothermic (20??C) Preservation for Pancreatic Microvasculature Using the Two-Layer Storage Method

Hypothermia causes vascular endothelial damage that leads to graft microcirculation disorder and eventually thrombosis after reperfusion. The two-layer cold storage method (TL) was previously demonstrated to supply oxygen to the pancreas graft and maintain high adenosine triphosphate tissue concentration. In this study, we evaluated whether mild hypothermic (20°C) preservation using the TL method could reduce endothelial damage while maintaining parenchymal viability. Graft survival by 20°C preservation was investigated using a dog segmental pancreas autotransplantation model (simple storage in University of Wisconsin solution (UW) for 5 and 8 hours or TL for 5, 8, 12, and 24 hrs, respectively). Subsequently, the grafts were preserved in four different conditions (4 and 20°C UW, 4 and 20°C TL) for 8 hours to evaluate microvascular endothelial damage. Trypan blue uptake of vascular endothelium and pancreatic tissue perfusion were evaluated. No graft preserved by 20°C UW for 5 and 8 hours survived (0/7 and 0/4). In contrast, the graft survival rates by 20°C TL for 5, 8, 12, and 24 hours were 100% (5/5), 80% (4/5), 20% (1/5), and 0% (0/4), respectively. In trypan blue uptake analysis, there were significant differences between 4 and 20°C in both UW and TL (4°C UW, 37% [n = 5) vs. 20°C UW, 13% [n = 4] [p < 0.01]; 4°C TL, 29% [n = 5] vs. 20°C TL, 10% [n = 5] [p < 0.01]). The perfusion values in 20°C TL were significantly higher than those in other groups at least for up to 120 minutes after reperfusion (p < 0.01). In short-term pancreas preservation, mild hypothermic TL reduced vascular endothelial cell damage and ameliorated graft microcirculation while maintaining parenchymal viability. Mild hypothermic TL may lessen vascular complications in clinical pancreas transplantation when used for several-hour preservation.

A Case of Poorly Differentiated Early Adenocarcinoma of the Stomach Forming a Protruded Type Lesion

Abstract: A case of poorly differentiated adenocarcinoma (undifferentiated type by Nakamura, diffuse type by Lauren) of the stomach infiltrating the submucosa and forming a protruded type lesion is reported. A 60‐year‐old man underwent endoscopic examination, which revealed a protruded type lesion with a nodular configuration and shallow ulceration accompanied by slough along the greater curvature of the upper gastric body, which was proved to be poorly differentiated adenocarcinoma by endoscopic biopsy. The patient underwent radical surgery, consisting of total gastrectomy with pancreato‐splenectomy. Macroscopic observation of the resected specimen revealed a protruded type lesion, measuring 30 mm in diameter, in the fundus along the greater curvature. The surface of the lesion had an irregular and nodular configuration with erythema and superficial erosions. Although, in the setting of early gastric cancer, poorly differentiated adenocarcinomas are usually macroscopically depressed or ulcerated type, this case presented a protruded type lesion (polypoid type). We report this unusual case because of its extremely important implications in the discussion of gastric cancer therapy.