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Biomedical subjects

Nobutsugu Abe

Publications and source records attributed to Nobutsugu Abe.

At least 19 recordsLinked to original sources
PubMed2006

Preoperative endoscopic pancreatic stenting for prophylaxis of pancreatic fistula development after distal pancreatectomy.

BACKGROUND AND OBJECTIVE: Pancreatic fistula is a common complication of distal pancreatectomy (DP). Although various surgical procedures have been proposed for DP in an attempt to decrease the high incidence of pancreatic fistula, the prevention of pancreatic fistula remains a major problem in DP. Endoscopic pancreatic stenting for the treatment or prophylaxis of such a fistula has been rarely described. METHODS: We reviewed 9 patients who underwent preoperative endoscopic pancreatic stenting for the prophylaxis of pancreatic fistula development after DP. RESULTS: Preoperative endoscopic pancreatic stenting was successfully performed with a 7F stent in all the 9 patients. Two patients, both with intraductal papillary mucinous tumor, developed mild acute pancreatitis after the stent placement. None of the 9 patients developed pancreatic fistula. The pancreatic stent was removed from 8 to 28 days (mean 11 days) postoperatively. CONCLUSIONS: Preoperative endoscopic pancreatic stenting may be an effective prophylactic measure against pancreatic fistula development following DP in selected patients.

Adenocarcinoma, Mucinous↗
PubMed2006

Anatomic study of the superior right colic vein: its relevance to pancreatic and colonic surgery.

BACKGROUND: This study was designed to describe the precise anatomic venous tributaries of the superior mesenteric vein with special emphasis on the superior right colic vein (SRCV), which is seldom mentioned in the literature. METHODS: Nine adult cadavers were dissected to define the venous tributaries of the superior mesenteric vein. The SRCV, middle colic vein, and right colic vein (RCV) were defined as those that drained from the marginal vein of the right flexure of the colon, the transverse colon, and the ascending colon, respectively. RESULTS: The SRCV was observed to drain from the right flexure of the colon to the confluence of the right gastroepiploic and superior pancreaticoduodenal veins and present the gastrocolic trunk of Henle (GTH) in 8 of 9 cases. The RCV terminated into the GTH in 4 cases. The SRCV, the RCV, and the middle colic vein formed a confluence and entered into the GTH in 1 case. CONCLUSIONS: The SRCV exits and drains from the right colonic flexure to the GTH in 89% of cases.

Adult↗
PubMed2006

Distribution of lymphatic vessels in the neural plexuses surrounding the superior mesenteric artery.

OBJECTIVES: To investigate whether lymphatic vessels exist in the neural plexuses surrounding the superior mesenteric artery (SMA) and the ultrastructural relationship between neural plexuses and lymphatic vessels. METHODS: A total of 970 serial sections including the structure surrounding the SMA were obtained from 9 cadavers. They were subjected to conventional hematoxylin/eosin staining and immunostaining for the lymphatic marker D2-40. Epithelial membrane antigen and S100 were also immunostained to identify the perineurium and nerve bundles, respectively. RESULTS: Thin-walled, erythrocyte-free vessels staining with lymphatic markers (D2-40) were found in the neural plexuses surrounding the SMA along a full circumference. There seemed to be a distribution correlation between lymphatic vessels and neural plexuses. Lymphatic vessels were not identified within the nerve bundles. The plexuses contained no lymph nodes in any sections. CONCLUSIONS: To our knowledge we report the immunohistochemical visualization of lymphatic vessels in peri-SMA neural plexuses for the first time. Therefore, particular attention should be paid to the lymphatic vessels within neural plexuses as a possible route of invasion and the source of pancreatic cancer recurrence.

Aged↗
PubMed2006

Actual number of tumor budding as a new tool for the individualization of treatment of T1 colorectal carcinomas.

BACKGROUND AND AIM: Treatment of T1 colorectal carcinomas, either local excision including endoscopic polypectomy or radical surgery, has always been problematic in everyday practice. Although previous studies have revealed that tumor budding at the invasive margin can be a marker for the malignant potential of T1 colorectal carcinomas, the evaluation of tumor budding has not been standardized as yet. In the present study, we attempted to apply the actual number of tumor budding units for the individualization of treatment in T1 colorectal carcinomas. METHODS: In 76 T1 colorectal carcinomas, associations between lymph node metastasis and clinicopathological parameters were examined statistically. A mathematical formula for predicting the risk of lymph node metastasis was constructed and decision analysis was attempted to determine individually the indication for additional surgery after endoscopic mucosal resection of T1 colorectal carcinomas. RESULTS: Of the clinicopathological parameters examined, multivariate analysis showed that the actual number of tumor budding units alone was significantly associated with lymph node metastasis. The probability of lymph node metastasis was calculated as Z = 0.07 x (budding counts) - 3.726, probability = 1/1 + e(-Z). The more the budding counts, the higher the probability of lymph node metastasis. This formula was able to accurately predict lymph node metastasis in successive cases. The actual number of tumor budding units can be applied to decision analysis in determining an indication for additional surgery after endoscopic mucosal resection of T1 colorectal carcinomas. CONCLUSIONS: The actual number of tumor budding units may be useful in the decision making for patient-oriented treatment of T1 colorectal carcinomas.

Adult↗
PubMed2006

Pancreatic carcinoma that completely obstructs the Wirsung duct without dilatation of the main pancreatic duct.

BACKGROUND AND AIM: Pancreatic carcinomas in which the main pancreatic duct (MPD) is completely obstructed are almost always associated with dilatation of the upstream MPD. However, some carcinomas are not associated with MPD dilatation despite complete MPD obstruction. This paradoxical phenomenon has not been well documented. METHODS: The findings from endoscopic retrograde cholangiopancreatography in 207 cases of pancreatic head carcinomas were analyzed with special reference to this unique type of carcinoma. Twenty-five of the patients were found to exhibit no MPD dilatation on ultrasonography, computed tomography or magnetic resonance imaging. RESULTS: Pancreatography via the major papilla showed complete obstruction of the MPD (112 patients with MPD dilatation and 6 without), stenosis (70 and 10, respectively), or no abnormal findings (0 and 9, respectively). In all six patients with complete MPD obstruction but without upstream MPD dilatation, injection of the minor papilla revealed a non-dilated dorsal pancreatic duct. The size of the obstructive carcinomas with and without MPD dilatation was comparable. CONCLUSIONS: Some (3%) pancreatic head carcinomas are not associated with MPD dilatation despite complete obstruction of the Wirsung duct. In such cases, the Santorini duct drains the dorsal pancreatic duct, completely compensating for the obstructed Wirsung duct. Attention should be paid to this unique type of carcinoma in diagnosing pancreatic head carcinomas.

Adenocarcinoma↗
PubMed2005

Tumor budding and evidence-based treatment of T2 rectal carcinomas.

BACKGROUND: The validity of the histological criteria in deciding additional bowel resection after local excision of T2 rectal carcinomas is questioned. METHODOLOGY: In 72 T2 colorectal carcinomas resected by major surgery, the associations between lymph node metastasis (LNM) and clinicopathologic parameters were examined statistically, a prediction formula for LNM was constructed and decision analysis was attempted. RESULTS: Multivariate analysis showed that female gender and a greater number of tumor budding were significantly associated with LNM. The probability of LNM can be calculated as follows; Z = 0.037 x (budding number) + 2.08 x (SEX; male, 1; female, 2) - 5.736; Probability = 1/1 + e(-Z). When a 75-year-old patient has pulmonary complications, the operative risk is assumed to be over 2%. If a number of tumor budding is 0, the risk of LNM is calculated as 2.4% in a male and 17.1% in a female patient. On the assumption that the risk of liver metastasis is half of that of LNM, and the salvageabilities after LNM and liver metastasis are 20% and 50%, respectively, observation policy is justified for a male patient, whereas additional surgery should be undertaken for a female patient. CONCLUSIONS: A number of tumor budding may be useful for determining the individualized treatment of T2 rectal carcinomas.

Cell Differentiation↗
PubMed2005

Laparoscopic pancreatic surgery.

In the past, in the pancreas, a minimally invasive technique was only used for diagnostic laparoscopy in evaluating periampullary malignancy. Recent advances in operative techniques and instrumentation have empowered surgeons to perform virtually all procedures in the pancreas, including the Whipple procedure. Some of these procedures represent the most sophisticated application of minimally invasive surgery, and their outcomes are reportedly better than those of conventional open approaches. In addition to the evaluation of resectability in periampullary malignancy, palliative procedures, including biliary bypasses and gastrojejunostomy, can be performed laparoscopically. Although it is reportedly feasible to perform a Whipple procedure laparescopically, no benefit of the laparoscopic approach over the conventional open approach has been documented. Laparoscopic distal pancreatectomy, with or without preserving the spleen, is technically easier than the Whipple procedure, and is more widely accepted. Indications for laparoscopic distal pancreatectomy include cystic neoplasms and islet-cell tumors located in the pancreatic body or tail. Complications of acute and chronic pancreatitis may be treated with the use of surgical laparoscopy. When infected necrotizing pancreatitis is identified, surgical intervention for drainage and debridement is required. According to the type and location of infected necrotizing pancreatitis, three laparoscopic operative approaches have been reported: infracolic debridement, retroperitoneal debridement, and laparoscopic transgastric pancreatic necrosectomy. When internal drainage is indicated for a pseudocyst, a minimally invasive technique is a promising option. Laparoscopic pseudocyst gastrostomy, cyst jejunostomy, or cyst duodenostomy can be performed, depending on the size and location of the pseudocyst. Especially when a pseudocyst is located in close contact with the posterior wall of the stomach, it is best drained by a pseudocyst gastrostomy, which can also be done with the use of an intragastric operative technique.

Debridement↗
PubMed2005

Effects of granulocyte colony-stimulating factor on neutrophils and inflammatory cytokines in the early stage of severe acute pancreatitis in rats.

BACKGROUND: The high mortality rate of severe acute pancreatitis (SAP) is closely associated with secondary infections of pancreatic and peripancreatic tissues. It was reported that granulocyte colony-stimulating factor (G-CSF) increased the number of leukocytes and enhanced their functions. However, an inflammatory response may be enhanced by an increased number of leukocytes. Our purpose was to study the roles of G-CSF in peritoneal-exudate neutrophils and inflammatory cytokines in the early stage of experimental SAP. METHODS: SAP was induced by injecting 0.2 ml of 3% taurocholate acid into the biliopancreatic duct in male Wistar rats. G-CSF (90 microg/kg body weight) or saline was administered 1 h before the SAP induction. The number of neutrophils and their phagocytic and bactericidal activities were evaluated, and the concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-1beta in plasma and ascitic fluid were measured 1 h and 3 h after the SAP induction. RESULTS: The number of peritoneal-exudate neutrophils (PENs) at 3 h was increased by G-CSF administration (81 +/- 50 x 10(5) cells/total exudate), as compared with that shown with saline administration (28 +/- 13 x 10(5) cells/total exudate; P < 0.05). The numbers of phagocytic and bactericidal neutrophils were also elevated by G-CSF administration. G-CSF administration did not increase the concentrations of TNF-alpha, IL-6, and IL-1beta in the plasma and ascitic fluid. CONCLUSIONS: G-CSF increases the numbers of neutrophils and enhances their functions against bacteria, but it does not enhance intraabdominal and systemic inflammatory responses in the early stage of SAP.

Animals↗
PubMed2005

Laparoscopic lymph node dissection after endoscopic submucosal dissection: a novel and minimally invasive approach to treating early-stage gastric cancer.

BACKGROUND AND OBJECTIVE: Endoscopic submucosal dissection (ESD), a newly developed endoscopic mucosal resection (EMR) technique, can completely cure a differentiated mucosal gastric cancer smaller than 2 cm. For early-stage gastric cancers (EGCs) deviating from the above-mentioned criterion, gastrectomy with lymph node dissection is performed for potential risk of lymph node metastasis (LNM). However, many of surgical EGC cases actually do not have LNM, indicating this surgery may not be necessary for many cases of EGC. To avoid this unnecessary surgery, we have introduced laparoscopic lymph node dissection (LLND) after ESD. Standard gastrectomy with extended lymph node dissection is indicated for patients if LLND reveals LNM. We present our novel approach and the preliminary results of EGC patients having potential risk of LNM. METHODS: Five patients with EGC deviating from the EMR criterion underwent the combination of ESD and LLND. ESD was performed using a newly developed insulation-tipped diathermic knife. Lymph nodes, which were determined on the basis of the location of the primary tumor and lymphatic drainage of the stomach, were removed laparoscopically. The lymphatic drainage was visualized by submucosally injecting indocyanine green (ICG) around the post-ESD ulcerative scars during intraoperative gastroscopy. RESULTS: The ESD enabled en bloc resection without any complications. The resected margins of all the lesions were free of cancer cells vertically and horizontally. LLND was successfully performed without any complications. The mean number of the dissected lymph nodes was 15 (range 6 to 22). In 4 of the 5 patients, the dissected lymph nodes were free of cancer cells, and therefore, the combination of ESD and LLND was considered a definitive treatment. The remaining patient was found to have LNM but chose not to undergo any surgery. During follow-ups, the patients' previous quality of life was restored without any tumor recurrence. CONCLUSIONS: The combination of ESD and LLND enables the complete resection of the primary tumor and the histologic determination of lymph node status. This combination treatment is a potential, minimally invasive method, and may obviate unnecessary gastrectomy without compromising curability for EGC patients having the potential risk of LNM.

Aged↗
PubMed2005

New guide wire technique for stent placement through an occluded self-expandable metal stent: The hairpin technique.

BACKGROUND AND AIMS: Self-expandable metal stents (SEMS) for malignant biliary strictures sometimes occlude, requiring the insertion of another stent. When a guide wire is advanced conventionally through the proximal portion of an occluded SEMS, the guide wire sometimes penetrates the stent mesh. The present study reports a new guide wire insertion technique that prevents this problem from occurring. METHODS: In this new method of advancing a guide wire, the tip is not straight but bent into a curve. Because the advancing end of the guidewire is rounded like a hairpin, it cannot penetrate the stent mesh. Before cannulation, the flexible tip of the guide wire is extended out of the tip of the cannula in the descending duodenum and then cannulation is carried out as the flexible tip makes a hairpin curve. The guide wire with a maintained hairpin curve is advanced through the proximal end of the SEMS. The hairpin curve pops open and the guide wire straightens out when the guide wire has passed through the SEMS. After that, a second stent can be inserted over the guide wire. This technique has been utilized 14 times for occluded SEMS in 10 patients between June 2001 and September 2003. RESULTS: In all patients the technique served to ensure access to the biliary tree and successful placement of a second stent. CONCLUSIONS: This new hairpin guide wire technique was effective in preventing the guide wire from penetrating the stent mesh and, therefore contributed to successful stent placement within occluded SEMS.

Biliary Tract Diseases↗
PubMed2005

Effect of granulocyte colony-stimulating factor on opsonin receptor expression in cerulein-induced acute pancreatitis.

OBJECTIVES: Decreased levels of expression of opsonin receptors (CD11b and CD32/16) on peritoneal exudate neutrophils may lead to susceptibility to infection. Granulocyte colony-stimulating factor (G-CSF) increases the expression levels of CD11b on neutrophils and prolongs neutrophil survival. The effects of G-CSF on neutrophils and opsonin receptor expressions of neutrophils were investigated in cerulein-induced acute pancreatitis. METHODS: Forty-two mice were randomly assigned to each group (n = 6). Mice received subcutaneous G-CSF (120 microg/kg body weight) before the induction of acute pancreatitis with cerulein. Saline was used for instead of G-CSF or cerulein solution in control groups. CD11b and CD32/16 expression levels on circulatory and peritoneal exudate neutrophils were investigated 6 and 24 hours after the induction of acute pancreatitis. RESULTS: Treatment with G-CSF did not aggravate the inflammation of pancreatic tissue evaluated by plasma amylase, acinar necrosis. However, it significantly increased the number of peritoneal exudate neutrophils (P < 0.05) and the CD11b- (P < 0.05) and CD32/16-positive (P < 0.05) peritoneal exudate neutrophils in mice with cerulein-induced acute pancreatitis. The means of fluorescence intensity for CD11b and CD32/16 expressions on circulatory and peritoneal exudate neutrophils were also elevated in the G-CSF groups. CONCLUSION: G-CSF administration increases the numbers of neutrophils and improves expression levels of opsonin receptors on neutrophils in mice with cerulein-induced acute pancreatitis.

Acute Disease↗
PubMed2005

[Recent important insights into treatment of pancreatic cancer].

Although surgical resection provides the only potentially curative modality in patients with pancreatic cancer, the long-term results of pancreatectomy still remain extremely poor. Despite the recent advances made in surgical techniques and/or increased surgical radicality, only limited progress has been made in improving the survival. Moreover, pancreatic cancer in most patients is surgically unresectable at the time of diagnosis. Chemotherapy and/or radiotherapy, therefore, still remain key modalities for treatment of pancreatic cancer. Recently, several randomized trials on the effects of these modalities have been reported. Various newly designed large-scale clinical trials are now in progress. In this article, recent important insights into the surgical treatment, chemotherapy, and radiotherapy of pancreatic cancer are discussed.

Antimetabolites, Antineoplastic↗
PubMed2004

A new reconstruction method for preventing delayed gastric emptying after pylorus-preserving pancreatoduodenectomy.

BACKGROUND: With the aim of preventing delayed gastric emptying after pylorus-preserving pancreatoduodenectomy (PPPD), we devised a new reconstruction method in which the pancreas and the bile duct are anastomosed to the proximal jejunum brought through the transverse mesocolon, and the duodenum is antecolically anastomosed to the jejunum below the mesocolon. The right gastric artery is divided in order to place the stomach, the duodenum, and the jejunum in a straight line. METHODS: Thirty patients underwent PPPD with the new reconstruction method (n = 12) or the conventional method (all anastomoses performed retrocolically; n = 18). Early and late complications were compared between the two groups. RESULTS: Delayed gastric emptying occurred respectively in 1 patient (8%) and 13 patients (72%) operated on by the new and conventional method (P <0.001). The incidences of other complications did not differ significantly between the two groups. CONCLUSIONS: The new reconstruction method may prevent delayed gastric emptying after PPPD.

Bile Ducts↗
PubMed2004

Endoscopic treatment or surgery for undifferentiated early gastric cancer?

BACKGROUND: Although almost all (96%) the surgical cases of undifferentiated intramucosal early gastric cancer (EGC) have been found not to have lymph node metastasis (LNM), local treatment by endoscopic mucosal resection (EMR) is not accepted as an alternative treatment to surgery for this type of EGC. If a subgroup of patients with undifferentiated EGC with negligible risk of LNM can be defined, unnecessary surgery can be avoided. This study was conducted to determine this subgroup among undifferentiated EGC patients in whom the risk of LNM can be highly ruled out in an attempt to identify candidates who can be treated by EMR. METHODS: Data from 175 patients surgically resected for undifferentiated EGC were retrospectively collected, and clinicopathological factors were multivariately analyzed to identify predictive factors for LNM. RESULTS: Multivariate logistic regression analysis identified two independent risk factors for LNM, namely, a large tumor (>/=20 mm, P = 0.011) and presence of lymphatic involvement (P = 0.0005). Using these two risk factors as the predictive factors, LNM was observed in 5.8% of patients who had neither of the two predictive factors, whereas 23.1% or 13.1% of patients with one or two predictive factors had LNM, respectively. In contrast, the LNM rate was calculated to be 60% in patients who had both factors. Lymph node metastasis was not found in any of 6 patients with small intramucosal lesions (<10 mm) without lymphatic involvement. CONCLUSIONS: An intramucosal undifferentiated EGC that is smaller than 10 mm without lymphatic involvement can safely be treated by EMR alone, given the negligible possibility of LNM. When histological examination of endoscopically resected specimens shows lymphatic involvement or unexpectedly larger tumor size than that determined at pre-EMR endoscopic diagnosis, an additional surgical procedure should be considered.

Adenocarcinoma↗