Takayuki Yamamoto

Takayuki Yamamoto

orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2000 in Diseases of the Colon & Rectum
Verified
Journal Article
Closed access
TYTakayuki Yamamoto
Takayuki Yamamoto
RARobert N. Allan
Robert N. Allan
MKMichael R. B. Keighley
Michael R. B. Keighley
This study examined risk factors for intra-abdominal sepsis after surgery in Crohn's disease. We reviewed 343 patients who underwent 1,008 intestinal anastomoses during 566 operations for primary or recurrent Crohn's disease between 1980 and 1997. Possible factors for intra-abdominal sepsis were analyzed by both univariate (chi-squared test) and multivariate (multiple regression) analyses. Intra-abdominal septic complications, defined as anastomotic leak, intra-abdominal abscess, or enterocutaneous fistula, developed after 76 operations (13 percent). Intra-abdominal septic complications were significantly associated with preoperative low albumin level (< 30 g/l; P = 0.04), preoperative steroids use (P = 0.03), abscess at the time of laparotomy (P = 0.03), and fistula at the time of laparotomy (P = 0.04). The intra-abdominal septic complication rate was 50 percent (8/16 operations) in patients with all of these four risk factors, 29 percent (10/35 operations) in patients with three risk factors, 14 percent (14/98 operations) in patients with two risk factors, 16 percent (33/209 operations) in patients with only one risk factor, and 5 percent (11/208 operations) in patients with none of these risk factors (P<0.0001). The following factors did not affect the incidence of septic complications; age, duration of symptoms, number of previous bowel resections, site of disease, type of operation (resection, strictureplasty, or bypass), covering stoma, and number, site, or method (sutured or stapled) of anastomoses. Preoperative low albumin level, steroid use, and the presence of abscess or fistula at the time of laparotomy significantly increased the risk of septic complications after surgery in Crohn's disease.

1 November 2007 in Diseases of the Colon & Rectum
Verified
Journal Article
Closed access
TYTakayuki Yamamoto
Takayuki Yamamoto
VFVictor W. Fazio
Victor W. Fazio
PTParis P. Tekkis
Paris P. Tekkis
This study was designed to review safety and efficacy of strictureplasty for Crohn's disease. A literature search was performed to identify studies published between 1975 and 2005 that reported the outcome of strictureplasty. Systematic review was performed on the following subjects separately: 1) overall experience of strictureplasty; 2) postoperative complications; 3) postoperative recurrence and site of recurrence; 4) factors affecting postoperative complications and recurrence; 5) short-bowel syndrome; and 6) cancer risk. Meta-analysis of recurrence rate after strictureplasty was performed by using random-effect model and meta-regressive techniques. A total of 1,112 patients who underwent 3,259 strictureplasties (Heineke-Mikulicz, 81 percent; Finney, 10 percent; side-to-side isoperistaltic, 5 percent) were identified. The sites of strictureplasty were jejunum and/or ileum (94 percent), previous anastomosis (4 percent), duodenum (1 percent), and colon (1 percent). After jejunoileal strictureplasty, including ileocolonic strictureplasty, septic complications (leak/fistula/abscess) occurred in 4 percent of patients. Overall surgical recurrence was 23 percent (95 percent confidence interval, 17-30 percent). Using meta-regressive analysis, the five-year recurrence rate after strictureplasty was 28 percent. In 90 percent of patients, recurrence occurred at nonstrictureplasty sites, and the site-specific recurrence rate was 3 percent. Two patients developed adenocarcinoma at the site of previous jejunoileal strictureplasty. The experience of duodenal or colonic strictureplasty was limited. Strictureplasty is a safe and effective procedure for jejunoileal Crohn's disease, including ileocolonic recurrence, and it has the advantage of protecting against further small bowel loss. However, the place for strictureplasty is less well defined in duodenal and colonic diseases.

2 September 2008 in International Journal of Colorectal Disease
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Journal Article
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PDF file
GRGeorge E. Reese
George E. Reese
TNTheodore Nanidis
Theodore Nanidis
CBCatherine Borysiewicz
Catherine Borysiewicz
TYTakayuki Yamamoto
Takayuki Yamamoto
TOTimothy Orchard
Timothy Orchard
PTParis Tekkis
Paris Tekkis

1 January 2005 in World Journal of Gastroenterology
Verified
Journal Article
Open access
TYTakayuki Yamamoto
Takayuki Yamamoto
Although in Crohn's disease post-operative recurrence is common, the determinants of disease recurrence remain speculative. The aim of this study was to examine factors affecting post-operative recurrence of Crohn's disease. A Medline-based literature review was carried out. The following factors were investigated: age at onset of disease, sex, family history of Crohn's disease, smoking, duration of Crohn's disease before surgery, prophylactic medical treatment (corticosteroids, 5-amino salicylic acid (5-ASA) and immunosuppressants), anatomical site of involvement, indication for surgery (perforating or non-perforating disease), length of resected bowel, anastomotic technique, presence of granuloma in the specimen, involvement of disease at the resection margin, blood transfusions and post-operative complications. Smoking significantly increases the risk of recurrence (risk is approximately twice as high), especially in women and heavy smokers. Quitting smoking reduces the post-operative recurrence rate. A number of studies have shown a higher risk when the duration of the disease before surgery was short. There were, however, different definitions of 'short' among the studies. Prophylactic corticosteroids therapy is not effective in reducing the post-operative recurrence. A number of randomized controlled trials offered evidence of the efficacy of 5-ASA (mesalazine) in reducing post-operative recurrence. Recently, the therapeutic efficacy of immunosuppressive drugs (azathioprine and 6-mercaptopurine) in the prevention of post-operative recurrence has been investigated and several studies have reported that these drugs might help prevent the recurrence. Further clinical trials would be necessary to evaluate the prophylactic efficacy of immunosuppressants. Several studies showed a higher recurrence rate in patients with perforating disease than in those with non-perforating disease. However, evidence for differing recurrence rates in perforating and non-perforating diseases is inconclusive. A number of retrospective studies reported that a stapled functional end-to-end anastomosis was associated with a lower recurrence rate compared with other types of anastomosis. However, prospective randomized studies would be necessary to draw a definite conclusion. Many studies found no difference in the recurrence rates between patients with radical resection and non-radical resection. Therefore, minimal surgery including strictureplasty has been justified in the management of Crohn's disease. In this review, the following factors do not seem to be predictive of post-operative recurrence: age at onset of disease, sex, family history of Crohn's disease, anatomical site of disease, length of resected bowel, presence of granuloma in the specimen, blood transfusions and post-operative complications. The most significant factor affecting post-operative recurrence of Crohn's disease is smoking. Smoking significantly increases the risk of recurrence. A short disease duration before surgery seems, albeit to a very minor degree, to be associated with a higher recurrence rate. 5-ASA has been shown with some degree of confidence to lead to a lower recurrence rate. The prophylactic efficacy of immunosuppressive drugs should be assessed in future. A wider anastomotic technique after resection may reduce the post-operative recurrence rate, though this should be investigated with prospective randomized controlled trials.

1 October 2007 in Diseases of the Colon & Rectum
Verified
Journal Article
Closed access
CSConstantinos Simillis
Constantinos Simillis
SPSanjay Purkayastha
Sanjay Purkayastha
TYTakayuki Yamamoto
Takayuki Yamamoto
SSScott A. Strong
Scott A. Strong
ADAra W. Darzi
Ara W. Darzi
PTParis P. Tekkis
Paris P. Tekkis
This study compared outcomes between end-to-end anastomosis and other anastomotic configurations after intestinal resection for patients with Crohn's disease by using meta-analytical techniques. Comparative studies published between 1992 and 2005 of end-to-end anastomosis vs. other anastomotic configurations were included. Using a random effects model, end points evaluated were short-term complications and perianastomotic recurrence of Crohn's disease. Heterogeneity was assessed and sensitivity analysis was performed to account for bias in patient selection. Eight studies (2 prospective, randomized, controlled trials; 1 nonrandomized, prospective; 5 nonrandomized, retrospective studies) reported on 661 patients who underwent 712 anastomoses, of which 383 (53.8 percent) were sutured end-to-end anastomosis and 329 (46.2 percent) were other anastomotic configurations (259 stapled side-to-side, 59 end-to-side or side-to-end, 11 stapled circular end-to-end). Anastomotic leak rate was significantly reduced in the other anastomotic configurations group (odds ratio (OR), 4.37; P = 0.02) and remained significantly lower in studies comparing only side-to-side anastomosis vs. end-to-end anastomosis (OR, 4.37; P = 0.02) and studies including only ileocolonic anastomosis (OR, 3.8; P = 0.05). Overall postoperative complications (OR, 2.64; P < 0.001), complications other than anastomotic leak (OR, 1.89; P = 0.04), and postoperative hospital stay (weighted mean difference, 2.81; P = 0.007) were significantly reduced in the side-to-side anastomosis group when considering studies comparing only side-to-side anastomosis vs. end-to-end anastomosis. There was no significant difference between the groups in perianastomotic recurrence and reoperation needed because of perianastomotic recurrence. End-to-end anastomosis after resection for Crohn's disease may be associated with increased anastomotic leak rates. Side-to-side anastomosis may lead to fewer anastomotic leaks and overall postoperative complications, a shorter hospital stay, and a perianastomotic recurrence rate comparable to end-to-end anastomosis. Further randomized, controlled trials should be performed for confirmation.

1 March 2018 in Gastroenterology
Verified
Journal Article
Closed access
PDF file
MNMakoto Naganuma
Makoto Naganuma
SSShinya Sugimoto
Shinya Sugimoto
KMKeiichi Mitsuyama
Keiichi Mitsuyama
TKTaku Kobayashi
Taku Kobayashi
NYNaoki Yoshimura
Naoki Yoshimura
RRRachel Roberts
Rachel Roberts