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Dive into the research topics where Ohsawa T is active.

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Featured researches published by Ohsawa T.


Surgery Today | 2009

Short-term intravenous antimicrobial prophylaxis in combination with preoperative oral antibiotics on surgical site infection and methicillin-resistant Staphylococcus aureus infection in elective colon cancer surgery: Results of a prospective randomized trial

Keiichiro Ishibashi; Kuwabara K; Toru Ishiguro; Ohsawa T; Okada N; Tatsuya Miyazaki; Masaru Yokoyama; Hideyuki Ishida

PurposeWe performed a prospective randomized study to assess the effectiveness of short-term intravenous antimicrobial prophylaxis in combination with preoperative oral antibiotics on a surgical site and methicillin-resistant Staphylococcus aureus (MRSA) infection in elective colon cancer surgery.MethodsThe patients were administered preoperative oral antibiotics, kanamycin and erythromycin, after mechanical cleansing, which began within 24 h of elective surgery for colon cancer. The patients were randomly assigned to receive the intravenous administration of cefmetazol or cefotiam on the day of surgery (group 1) or for 3 days (group 2). A total of 275 patients (136 for group 1 and 139 for group 2) were eligible for the study.ResultsThe incidence of a surgical site infection was 5.1% in group 1 and 6.5% in group 2 (P = 0.80). The incidence of MRSA infection was 2.2% in group 1 and 2.9% in group 2 (P > 0.99). A multivariate logistic regression analysis showed that the American Society of Anesthesiologists physical status score and the duration of surgery were independent significant factors affecting the surgical site infection and MRSA infection.ConclusionThese findings suggest that short-term intravenous antimicrobial prophylaxis in combination with preoperative oral antibiotics may be successfully applied to colon cancer surgery that is generally performed in Japan.


Surgical Endoscopy and Other Interventional Techniques | 2005

Minilaparotomy approach for colonic cancer: initial experience of 54 cases

Hideyuki Ishida; Hiroshi Nakada; Masaru Yokoyama; Yoichi Hayashi; Ohsawa T; Sigehisa Inokuma; Takanobu Hoshino; Daijo Hashimoto

BackgroundThe early outcomes of minilaparotomy for resection of colonic cancer were evaluated.MethodsIn this study, 54 patients (34 Dukes’ A, 15 Dukes’ B, and 5 Dukes’ C) successfully underwent curative resection of colonic cancer via minilaparotomy (skin incision, =7 cm). The major exclusion criteria for this approach required a body mass index greater than 25 kg/m2, a tumor size exceeding 7 cm, a preoperative ileus, and tumor invading the adjacent organs. Patients (n = 54) who had undergone conventional open surgery before the introduction of this technique served as the control group by matching several clinicopathologic factors including body mass index.ResultsThe passage of flatus (p < 0.01) and the beginning of oral intake (p = 0.02) were earlier, analgesic requirements were lower (p < 0.01), and postoperative serum C-reactive protein levels were lower in the minilaparotomy group (p < 0.01). The blood loss and frequency of postoperative complications did not differ between the groups.ConclusionA minilaparotomy approach is a feasible, minimally invasive, and attractive alternative to conventional laparotomy for selected patients with colonic cancer.


Surgery Today | 2003

Carcinosarcoma of the rectosigmoid colon: Report of a case

Hideyuki Ishida; Ohsawa T; Hiroshi Nakada; Daijo Hashimoto; Takeshi Ohkubo; Akiko Adachi; Shinji Itoyama

We report an unusual case of carcinosarcoma of the colon. An 80-year-old woman was admitted to our hospital with lower abdominal pain. Computed tomography showed a large pelvic mass, 18 cm in maximal diameter, and barium enema and colonoscopy both showed a type-2 tumor in the sigmoid colon. We performed Hartmanns procedure with resection of the ileocolic segment. Immunohistochemical stains of the resected specimen revealed that most of the tumor consisted of spindle cell sarcoma with neural and muscle differentiation, while only the superficial area of an ulcerated lesion contained adenocarcinoma positive for carcinoembryonic antigen. The patient died of a fast-growing recurrent pelvic tumor 6 months postoperatively. Our experience of this case and our review of eight other cases in the English literature indicate that wide resection provides the best chance of cure, but careful postoperative follow-up is essential.


International Surgery | 2011

Three-dimensional vascular anatomy relevant to oncologic resection of right colon cancer.

Yusuke Tajima; Hideyuki Ishida; Ohsawa T; Kensuke Kumamoto; Keiichiro Ishibashi; Haga N; Hisato Osada

We analyzed data on the three-dimensional vascular anatomy of the right colon from the operative documents of 215 patients undergoing oncologic resection for right colon cancer. The right colic artery (RCA) was absent in 146 patients (67.9%), with the ileocolic artery (ICA) crossing the superior mesenteric vein (SMV) ventrally in 78 patients (36.3%). When the RCA was present, both the ICA and the RCA crossed the SMV ventrally in 44 patients (20.5%), dorsally in 10 patients (4.7%), the RCA crossed the SMV ventrally and the ICA dorsally in 10 patients (4.7%), and the RCA crossed the SMV dorsally and the ICA ventrally in 5 patients (2.2%). The arterial branches toward the hepatic flexure crossed the SMV ventrally in 151 eligible cases: the branch originated from the common trunk of the middle colic artery in 97 patients (64.2%) and 1 and 2 arteries directly originated from the SMA in 49 patients (32.5%) and in 5 patients (3.3%), respectively. These data would be useful to safely perform lymph node dissection around the SMV.


Surgical Endoscopy and Other Interventional Techniques | 2003

Gasless laparoscopic surgery for ulcerative colitis and familial adenomatous polyposis

Hideyuki Ishida; Daijo Hashimoto; Sigehisa Inokuma; Hiroshi Nakada; Ohsawa T; Takanobu Hoshino

PURPOSE We evaluated the data on initial experience of gasless laparoscopic surgery for patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). PATIENTS AND METHODS Seven patients (male/female = 3:4, median age 23, UC/FAP=5:2) underwent gasless laparoscopic total (procto) colectomy. Our basic surgical procedure involved (1) a 6- to 8-cm incision made at the beginning of the operation, (2) the wound pulled upward and/or laterally by retractors, and (3) conventional surgical instruments used through the wound; occasionally laparoscopic assistance and abdominal lifting were employed. The results were compared to those of 7 patients who had undergone conventional open surgery. RESULTS Oral intake started earlier (p = 0.03) and C-reactive protein level on POD 4 was lower (p = 0.03) in the gasless group than in the control group. Duration of surgery, blood loss, requirement of analgesia, and morbidity rate were not significantly different between the groups. CONCLUSION Our preliminary results suggest that gasless laparoscopic surgery for UC and FAP is feasible and can be an alternative method for minimally invasive surgery.


Surgery Today | 2011

Impact of prior abdominal surgery on curative resection of colon cancer via minilaparotomy.

Hideyuki Ishida; Tohru Ishiguro; Keiichiro Ishibashi; Ohsawa T; Kuwabara K; Okada N; Tatsuya Miyazaki

PurposeTo evaluate the impact of prior abdominal surgery on curative resection of colon cancer via a minilaparotomy approach.MethodsFeasibility, safety, and oncological outcomes were evaluated retrospectively in 263 patients scheduled to undergo curative resection of colon cancer via a minilaparotomy approach, defined as a skin incision of ≤7 cm, between September 2000 and March 2009.ResultsAbdominal adhesions were found in 59 (77.6%) of 76 patients who had undergone prior abdominal surgery (PAS group) and in 4 (2.1%) of 187 patients who had not (control group). The success rate of the minilaparotomy approach was 92.1% in the PAS group and 97.3% in the control group (P = 0.08). The incidence of extending the minilaparotomy wound for adhesiolysis was significantly higher in the PAS group than in the control group (6.6% vs 0.5%; P < 0.01). The two groups did not differ significantly in terms of the types of surgery, pathological stage, body mass index, operative time, blood loss, incidence of postoperative complications, length of postoperative hospital stay, and diseasefree survival.ConclusionsThese results suggest that prior abdominal surgery might require an extension of the minilaparotomy incision but that it does not seem to contraindicate a minilaparotomy approach for curative colectomy.


Molecular Medicine Reports | 2009

Colorectal cancer susceptibility associated with the hMLH1 V384D variant.

Ohsawa T; Tomoko Sahara; Shino Muramatsu; Yoji Nishimura; Toshimasa Yathuoka; Yoichi Tanaka; Kensei Yamaguchi; Hideyuki Ishida; Kiwamu Akagi

Lynch syndrome is an autosomal dominant colorectal cancer susceptibility syndrome caused by a dysfunction of DNA mismatch repair genes, including MLH1, MSH2, MSH6 and PMS2. However, the interpretation of certain changes in the mismatch repair genes is perplexing, as these changes do not necessarily affect the function of the protein. The pathogenicity of the hMLH1 1151T↷A variant, which results in an amino-acid substitution of valine for aspartic acid at codon 384 (V384D), is also controversial. This study was undertaken to assess the clinicopathological features of colorectal cancer patients harboring the hMLH1 V384D variant. Two independent Japanese cohorts, comprising 670 colorectal cancer patients and 332 cancer-free controls, respectively, were genotyped by polymerase chain reaction (PCR)-RFLP. The allele frequency of V384D was 0.75% in the control group and 3.1% in the colorectal cancer group (p<0.001). Thus, the V384D variant was associated with increased colorectal cancer susceptibility. However, only 5% of the colorectal cancer patients carrying the V384D variant had high micro-satellite instability; most had microsatellite-stable cancer. Additionally, these patients had no clear familial history of Lynch syndrome-related tumors. The combined results indicate that hMLH1 V384D allele frequency was 4.1-fold higher in the colorectal cancer group than in the control group. Thus, the hMLH1 V384D variant may contribute to the development of microsatellite-instable as well as -stable colorectal cancer.


International Surgery | 2011

Significance of hepatic lymph node metastasis in patients with unresectable synchronous liver metastasis of colorectal cancer.

Hideyuki Ishida; Keiichiro Ishibashi; Ohsawa T; Okada N; Kensuke Kumamoto; Haga N

The frequency and significance of hepatic lymph node (HLN) metastasis were retrospectively evaluated in 43 patients with unresectable synchronous liver metastasis of colorectal cancer who underwent resection of the primary tumor and histopathologic evaluation of HLNs between March 1997 and August 2007. HLN metastasis was detected in 12 patients (27.9%). No significant correlations were observed between the presence of HLN metastasis and any of the 12 clinicopathologic factors examined. On multivariate analysis using the Cox proportional hazards model, the presence of HLN metastasis (P = 0.002), along with a large number (> or = 4) of regional lymph node metastases (P = 0.003), and nonuse of oxaliplatin-based chemotherapy (P = 0.005) were identified as independent risk factors for shorter survival. To establish a new therapeutic strategy for initially unresectable liver metastasis of colorectal cancer, HLNs should be examined histologically in patients undergoing resection of hepatic lesions when they are rendered resectable by effective chemotherapy.


International Surgery | 2011

Minilaparotomy for perforated duodenal ulcer.

Hideyuki Ishida; Toru Ishiguro; Kensuke Kumamoto; Ohsawa T; Jun Sobajima; Keiichiro Ishibashi; Haga N

The usefulness of the minilaparotomy approach for perforated duodenal ulcer repair was retrospectively evaluated in 37 patients (26 men; mean age, 56.5 years). Simple closure with an omental patch by minilaparotomy (skin incision, < or = 7 cm) was successful in 86.5% of the cases, with an operative mortality of 2.7%. Compared with the results in historic control patients who underwent conventional open surgery (n = 27), a shorter operative time (P < 0.01), lower frequency of analgesic use (P = 0.03), earlier passage of flatus (P < 0.01), and shorter hospital stay (P = 0.04) were obtained in the patients undergoing minilapartomoy. The postoperative morbidity was identical between the two groups (16.2% versus 33.3%, P = 0.40). On multivariate analysis, a large amount of intraabdominal fluid was the only significant risk factor for extension of the minilaparotomy wound (P = 0.012). The minilaparotomy approach appears to be a feasible, safe, and less invasive approach compared with the conventional open approach and could be a useful alternative to the laparoscopic approach in selected patients with perforated duodenal ulcer.


International Surgery | 2011

Curative resection of transverse colon cancer via minilaparotomy.

Hideyuki Ishida; Tohru Ishiguro; Keiichiro Ishibashi; Ohsawa T; Okada N; Kensuke Kumamoto; Haga N

Minilaparotomy has been reported to be a minimally invasive alternative to laparoscopically assisted surgery. We retrospectively evaluated the usefulness of minilaparotomy for the resection of transverse colon cancer, which has generally been considered difficult to resect laparoscopically. Patients for whom curative resection was attempted for transverse colon cancer (n = 21) or sigmoid colon cancer (n = 81) via minilaparotomy (skin incision, < or = 7cm) were analyzed. The 2 groups did not significantly differ in terms of success rate of minilaparotomy (90.5% versus 97.5%), age, sex, pathologic stage, body mass index, operative time (mean, 133.5 minutes versus 122.5 minutes), blood loss (119.7 mL versus 92.4 mL), number of lymph nodes harvested, incidence of postoperative complications (9.5% versus 12.3%), postoperative length of stay, and 5-year disease-free survival rate (86.6% versus 79.6%). Minilaparotomy is feasible, safe, and favorable in terms of early oncologic outcome in patients with transverse colon cancer as well as those with sigmoid colon cancer.

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Hideyuki Ishida

Saitama Medical University

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Okada N

Saitama Medical University

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Masaru Yokoyama

Saitama Medical University

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Kensuke Kumamoto

Fukushima Medical University

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Haga N

Saitama Medical University

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Toru Ishiguro

Saitama Medical University

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Daijo Hashimoto

Saitama Medical University

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Kuwabara K

Saitama Medical University

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Jun Sobajima

Saitama Medical University

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