Biomedical subjects

Kazunori Yokohata

Publications and source records attributed to Kazunori Yokohata.

7 recordsLinked to original sources

PubMed2006

Merits and faults of transanal ileus tube for obstructing colorectal cancer.

BACKGROUND: We report eight cases of obstructing colorectal cancer successfully managed by preoperative lavage using transanal ileus tube. METHODS: Decompression tube was transanally inserted into the colon proximal to the tumour under the guidance of the guide wire. Intestinal lavage with 1,500-2,000 mL of warm water was done every day until surgery. RESULTS: There were six men and two women; the mean age was 67 years (range, 50-82 years). Three cancers were in the sigmoid colon and five were in the rectum. Seven patients were treated with a one-stage operation with adequate lymph node dissection. In one patient, only sigmoidostomy was carried out for unresectable huge tumour. In all cases, no dilatation was observed at the proximal colon and no anastomotic failure developed. Four patients suffered from fever of unknown cause after the insertion of the tube. In one patient, the resected specimen showed ulcer by tube compression. In the other patient, the tube penetrated the intestinal wall, which was covered by mesentery. CONCLUSION: The transanal ileus tube is effective for the treatment of obstructing colorectal cancer. However, close observation is necessary because of possible perforation.

Aged↗

PubMed2003

Severe localized stenosis and marked dilatation of the main pancreatic duct are indicators of pancreatic cancer instead of chronic pancreatitis on endoscopic retrograde balloon pancreatography.

BACKGROUND: Differentiation between benign and malignant localized stenoses of the main pancreatic duct is difficult by pancreatography. METHODS: A total of 48 patients with such localized stenosis who underwent endoscopic retrograde balloon pancreatography with abdominal compression were retrospectively studied. The following were examined: (1) diameter of the stenotic, prestenotic, and poststenotic ductal segments; (2) ratios of prestenotic/poststenotic, stenotic/prestenotic, and stenotic/poststenotic ductal segments; (3) length of stenosis and steepness of transition to the stenosis (proximal angle, distal angle); and (4) main duct and branch findings for peristenotic segments. RESULTS: The stenosis was diagnosed as caused by chronic pancreatitis in 27 patients and pancreatic cancer in 21 by histopathology, cytology, or clinical follow-up. The prestenotic/poststenotic ductal segments ratio and proximal angle were greater in pancreatic cancer compared with chronic pancreatitis. Severe stenosis (stenotic ductal segments less than 20% of prestenotic or poststenotic ductal segments); moderate (prestenotic ductal segments 2.5 to 3.5 times larger than poststenotic ductal segments), and severe (prestenotic ductal segments more than 3.5 times larger than poststenotic ductal segments) dilatation of the proximal duct were more frequent in pancreatic cancer than in chronic pancreatitis. Multivariate regression analyses showed that severe stenosis and dilatation were independently significant parameters that indicated a diagnosis of pancreatic cancer. Various combinations of severe stenosis, proximal dilatation, and double duct sign gave high predictive values. CONCLUSIONS: Severe stenosis, marked proximal dilatation, double duct sign, and combinations of these findings are useful indicators of malignant localized stenosis of the pancreatic duct.

Adult↗

PubMed2002

Laparoscopic choledochotomy for bile duct stones.

In the era of laparoscopic surgery, treatment strategies for common bile duct stones remain controversial. Laparoscopic choledochotomy is usually indicated only when transcystic duct exploration is not feasible. However, laparoscopic choledochotomy provides complete access to the ductal system and has a higher clearance rate than the transcystic approach. In addition, primary closure of the choledochotomy with a running suture and absorbable clips facilitates the procedure. Therefore, to avoid postoperative biliary stenosis, all patients with bile duct stones can be indicated for choledochotomy, except for those with nondilated common bile duct. Placement of a C-tube also provides access for the clearance of possible retained stones by endoscopic sphincterotomy as a backup procedure. C-tube placement, in contrast to T-tube insertion, is advantageous in terms of a relatively short hospital stay. In conclusion, laparoscopic choledochotomy with C-tube drainage is recommended as the treatment of choice for patients with common bile duct stones.

Biliary Tract Surgical Procedures↗

PubMed2002

Comparison of recovery of gastric phase III motility and gastric juice output after different types of gastrointestinal reconstruction following pylorus-preserving pancreatoduodenectomy.

BACKGROUND: Early gastric stasis is a frequent complication of pylorus-preserving pancreatoduodenectomy (PPPD). However, few reports have addressed this phenomenon in relation to the type of gastrointestinal reconstruction. We compared gastrointestinal motility and gastric juice output after two different types of gastrointestinal reconstruction following PPPD, end-to-side duodenojejunostomy after pancreaticojejunostomy and hepaticojejunostomy (group 1) and end-to-end duodenojejunostomy before pancreaticojejunostomy and hepaticojejunostomy (group 2). METHOD: In a total of 25 patients, 10 in group 1 and 15 in group 2, who underwent PPPD, manometry was repeated to assess gastric and jejunal motility until the first occurrence of phase III activity of gastric cyclic motor activity (CMA). The plasma level of motilin was measured in each phase of the gastric CMA and compared between the two groups. The daily volume of gastric juice output through a gastrostomy tube was also recorded for comparison. RESULT: There was no significant difference in the time period for recovery of gastric phase III activity and gastric juice output between the two groups. However, abnormal contractions with an increased basal pressure appeared frequently in the afferent jejunal loop only in group 1. The plasma motilin level after PPPD showed no apparent cyclic change even after the recovery of gastric phase III in either group. CONCLUSION: Gastrointestinal reconstructive procedures have almost no effect on the recovery of gastric CMA. The plasma motilin concentration does not play a major role in the recovery of gastric CMA in the early postoperative period after PPPD.

Adult↗

PubMed2002

Biliary sphincter motility after neural isolation of the pancreatoduodenal region in conscious dogs.

BACKGROUND: Several neural and hormonal factors are known to affect the motility of the sphincter of Oddi. However, the precise mechanisms of the control of sphincter motility have not been completely explored. We investigated the relationship of canine biliary sphincter motility when it is extrinsically denervated by neural isolation of the pancreatoduodenal region. METHODS: Interdigestive and postprandial sphincter motility in a denervated pancreatoduodenal segment and effects of cholecystokinin-octapeptide were studied in 7 conscious dogs. Data were compared with those of 7 neurally intact control dogs. RESULTS: After extrinsic denervation of the pancreatoduodenal region, sphincter motility exerted a cyclic change in concert with the duodenal myoelectric cycles; this change involved short cyclic bursts of motor activity, which gradually increased in intensity. The increase in the cyclic bursts of motor activity was also cyclic and associated with an increase in the plasma motilin concentration. Neural isolation of the pancreatoduodenal region increased sphincter basal pressure and motility index (integral per minute). In the denervated biliary sphincter, the feeding pattern and temporary inhibitory effect of feeding, as seen in controls, were absent, which suggests the role of extrinsic nerves in delivering bile into the duodenum after feeding. In the denervated dogs, cholecystokinin-octapeptide caused excitation of the sphincter activity, instead of relaxation observed in controls. CONCLUSIONS: Extrinsic innervation to the pancreatoduodenal region has an inhibitory effect on biliary sphincter motility. Abnormalities in extrinsic innervation to the biliary sphincter might increase the resistance of the sphincter to the bile flow and induce bile stagnation.

Animals↗

PubMed2002

Gastric phase 3 motility after pylorus-preserving pancreatoduodenectomy.

OBJECTIVE: To analyze factors affecting the recovery course of phase 3 activity of the gastric migrating motor complex after pylorus-preserving pancreatoduodenectomy (PPPD) and investigate effects of the recovery of gastric phase 3 on gastric emptying after feeding. SUMMARY BACKGROUND DATA: Whether early recovery of gastric phase 3 during fasting would predict early recovery of the fed-state gastric emptying function after PPPD has not been well documented. METHODS: Manometric recording from the gastric antrum was repeated at a weekly interval until the first appearance of gastric phase 3 in 57 patients after PPPD. Twenty-three clinical parameters were assessed as possible factors affecting the recovery course of gastric phase 3 by simple and multiple regression analyses. A gastric emptying study after feeding of a test meal was performed by the acetaminophen method and the values were compared between patients with and without gastric phase 3 after PPPD. RESULTS: The mean period before the first appearance of gastric phase 3 was 38 days. Among 23 parameters, only lymph node dissection along the hepatoduodenal ligament significantly delayed recovery of gastric phase 3 after PPPD by univariate and multivariate analyses. The presence or absence of gastric phase 3 in the early postoperative period did not influence gastric emptying after feeding in the intermediate period after PPPD. CONCLUSIONS: Avoiding lymph node dissection along the hepatoduodenal ligament, if applicable, may contribute to early recovery of gastric phase 3 after PPPD. The recovery state of gastric phase 3 during fasting, however, is not necessarily consistent with the degree of improvement of gastric emptying after feeding.

Adult↗

PubMed2002

Effect of truncal vagotomy on sphincter of oddi cyclic motility in conscious dogs.

OBJECTIVE: To evaluate the effects of truncal vagotomy at the diaphragmatic level on the sphincter of Oddi (SO) motility. SUMMARY BACKGROUND DATA: Cholelithiasis is a well-known late complication after gastrectomy and/or vagotomy. The mechanism of gallstone formation is only partly understood, and few studies address the effects of vagotomy on SO cyclic motility in conscious subjects. METHODS: In conscious dogs, SO motility was recorded by retrograde infusion manometry through a duodenal cannula before and after bilateral truncal vagotomy at the diaphragmatic level. Effects of cholecystokinin-octapeptide and feeding were also evaluated before and after vagotomy. RESULTS: SO cyclic motility and the gastroduodenal migrating motor complex continued to occur during postvagotomy fasting. Intermittent inhibitions of the SO and duodenal contractions disappeared during phase 3 of the migrating motor complex. SO basal pressure significantly decreased, whereas the amplitude significantly increased. Cholecystokinin-octapeptide inhibited SO contractions before and after vagotomy. The amplitude of SO contractions increased and their frequency decreased after feeding; however, these effects disappeared after vagotomy. CONCLUSIONS: SO cyclic motility and the effects of feeding change after truncal vagotomy at the diaphragmatic level. These facts may at least partly explain gallstone formation after gastric surgery and/or vagotomy.

Animals↗