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Dive into the research topics where Yusuke Nishizawa is active.

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Featured researches published by Yusuke Nishizawa.


International Journal of Colorectal Disease | 2008

Relationship between multiple numbers of stapler firings during rectal division and anastomotic leakage after laparoscopic rectal resection.

Masaaki Ito; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa; Yoshiyuki Tsunoda; Norio Saito

BackgroundWe experienced some technical difficulty in dividing the middle and lower rectum through the right-lower quadrant intracorporeally. The aim of this study was to determine whether multiple stapler firings during rectal division are associated with anastomotic leakage after laparoscopic rectal resection.MethodsLaparoscopic anterior resection with double-stapling technique anastomosis was performed in 180 consecutive rectal cancer patients. We often used vertical rectal division through a suprapubic site instead of the standard transverse rectal division for laparoscopic total mesorectal excision (LapTME). We attempted to determine whether there was an association between the number of stapler firings and procedures in rectal division. Moreover, we identified risk factors for anastomotic leakage after laparoscopic rectal resection by multivariate analysis.ResultsAnastomotic leakage occurred in 5% of the subjects of this study. Vertical rectal division through the suprapubic site after Lap TME required fewer staples than transverse division through the right-lower port and a smaller percentage of patients required three or more staples for vertical rectal division than for transverse division (15% vs. 45%, p = 0.03). In the multivariate analysis, TME and the number of staplers used for rectal division were the factors found to be associated with a significantly greater risk of subsequent leakage (odd’s ratio = 5.3; 95% CI 1.2–22.7 and odd’s ratio = 4.6; 95% CI 1.1–19.2).ConclusionTME and multiple stapler firings during distal rectal division were associated with anastomotic leakage after laparoscopic rectal resection. Vertical rectal division through a suprapubic site was a useful method of avoiding multiple stapler firings during laparoscopic TME.


Diseases of The Colon & Rectum | 2009

Analysis of clinical factors associated with anal function after intersphincteric resection for very low rectal cancer.

Masaaki Ito; Norio Saito; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa; Yoshiyuki Tsunoda

PURPOSE: The purpose of this study was to identify factors that have a negative impact on anal function after intersphincteric resection. METHODS: We evaluated postoperative anal function in 96 patients with very lower rectal cancer who underwent intersphincteric resection by having patients fill out detailed questionnaires at 3, 6, 12, and 24 months after surgery. Univariate and multivariate analysis based on the Wexner incontinence score were used to identify factors associated with poor anal function after intersphincteric resection. RESULTS: The mean Wexner score at 12 months after stoma closure was 10.0. Patients with frequent major soiling showed a Wexner score of ≥16, and this score was used as a cutoff value of poor anal function. In the univariate analysis, poor anal function was significantly associated with a greater extent of excision of the internal sphincter and with preoperative chemoradiotherapy. In the multivariate analysis, preoperative chemoradiotherapy was the only independent factor associated with poor anal function after intersphincteric resection (odds ratio=10.3; 95 percent confidence interval, 2.3-46.3, P < 0.01). CONCLUSIONS: Preoperative chemoradiotherapy was identified as the risk factor with the greatest negative impact on anal function after intersphincteric resection, regardless of extent of excision of the internal sphincter.


Diseases of The Colon & Rectum | 2011

The association between anal function and neural degeneration after preoperative chemoradiotherapy followed by intersphincteric resection.

Yuji Nishizawa; Satoshi Fujii; Norio Saito; Masaaki Ito; Atsushi Ochiai; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa

BACKGROUND: Preoperative chemoradiotherapy for rectal cancer is administered to improve local control, but it can also induce severe anal dysfunction after surgery. OBJECTIVE: The goals of the study were to assess the influence of preoperative chemoradiotherapy on pathological findings and to examine the correlation of these findings with the cause of severe anal dysfunction after intersphincteric resection. DESIGN: Peripheral nerve degeneration was evaluated histopathologically with the use of hematoxylin and eosin-stained sections of surgical specimens after intersphincteric resection, based on karyopyknosis, vacuolar degeneration, acidophilic degeneration of cytoplasm, denucleation, and adventitial neuronal changes. Each item was scored to quantify the level of neural degeneration, and the relationship between degeneration and anal function was examined at 12 months after closure of the stoma. Anal function was assessed by questionnaire, and incontinence was evaluated based on the Wexner score. SETTING: This study was conducted at the National Cancer Center Hospital East from 2001 to 2006. PATIENTS: The subjects were 68 patients with lower rectal cancer who underwent intersphincteric resection with (n = 47) or without (n = 21) preoperative chemoradiotherapy. MAIN OUTCOME MEASURES: The findings in the 2 groups were compared to clarify the association between the degree of histological degeneration and postoperative anal function. RESULTS: Neural degeneration was significantly higher in the chemoradiotherapy group, and the neural degeneration and Wexner scores had a significant correlation (P = .003, r = 0.477). CONCLUSION: Preoperative chemoradiotherapy induced marked neural degeneration around the rectal tumor. The significant correlation between the degeneration score and postoperative anal function suggests that this score may be a useful marker to predict the influence of preoperative chemoradiotherapy on anal function after surgery.


Surgery Today | 2011

Association Between Incisional Surgical Site Infection and the Type of Skin Closure After Stoma Closure

Shin Kobayashi; Masaaki Ito; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa; Norio Saito

PurposeThis study was performed to investigate the effect of subcuticular sutures on the incidence of incisional surgical site infection (SSI) after closure of a diverting stoma.MethodsThe study was carried out as a retrospective analysis of prospectively collected data from 51 patients who underwent closure of diverting stoma following resections of lower rectal cancer between January 2008 and December 2008. This study attempted to determine whether there was an association between the type of skin closure and the incidence of incisional SSI. Moreover, risk factors for incisional SSI after closure of diverting stoma were identified using a multivariate analysis.ResultsAn incisional SSI occurred in 12 of the 51 patients (23.5%). The rate of incisional SSI with subcuticular sutures was 11.1% (3/27) in comparison to 37.5% (9/24) with transdermal suture and skin stapler. A subcuticular skin closure was the only favorable factor that was significantly associated with a lower incidence of incisional SSI (odds ratio: 0.19; 95% confidence interval: 0.04–0.92).ConclusionsA subcuticular skin closure has a protective effect against incisional SSI after closure of diverting stoma. A larger study is necessary to further define the role of subcuticular suture on the prevention of incisional SSI in cases of gastrointestinal surgery.


Diseases of The Colon & Rectum | 2011

Predictive factors for pulmonary metastases after curative resection of rectal cancer without preoperative chemoradiotherapy.

Kazuhiro Watanabe; Norio Saito; Masanori Sugito; Masaaki Ito; Akihiro Kobayashi; Yusuke Nishizawa

OBJECTIVE: The aim of this study was to clarify the actuarial incidence of pulmonary metastases and risk factors for pulmonary metastases after curative resection of rectal cancer without preoperative chemoradiotherapy. DESIGN: This study was a retrospective review. PATIENTS: Data for 314 patients who underwent R0 resection for rectal cancer without preoperative chemoradiotherapy from 2000 to 2006 were reviewed. The mean duration of follow-up was 57.0 months. RESULTS: Pulmonary metastases developed in 41 patients. Mean duration from rectal surgery to identification of pulmonary metastases was 21.1 months. Surgery for pulmonary metastases was performed first for 19 patients (46.3%), and all patients achieved R0 surgery. Multivariate analysis revealed that tumor depth (T3 to T4), lymph node ratio (>0.091), and tumor location (anal canal) were significant independent risk factors for pulmonary metastases. Five-year actuarial incidence of pulmonary metastasis increased significantly with increased numbers of risk factors (0 factors, 1.1%; 1 factor, 13.2%; ≥2 factors, 40.1%). In terms of lateral pelvic lymph node involvement, the number of lateral pelvic lymph node involvements (≥4) and the distribution of lateral pelvic lymph node metastases (bilateral) were significant risk factors for pulmonary metastases. CONCLUSIONS: The present study clearly demonstrated predictive factors for pulmonary metastases after R0 resection of rectal cancer without preoperative chemoradiotherapy. Actuarial incidence of pulmonary metastases was significantly related to the number of risk factors present. The data from the present study should facilitate the establishment of novel algorithms for predicting pulmonary metastases after resection of rectal cancer, which may lead to the appropriate surveillance strategies after rectal surgery.


Japanese Journal of Clinical Oncology | 2011

Postoperative Lymphocyte Percentage Influences the Long-term Disease-free Survival Following a Resection for Colorectal Carcinoma

Yasuo Yoneyama; Masaaki Ito; Masanori Sugitou; Akihiro Kobayashi; Yusuke Nishizawa; Norio Saito

OBJECTIVE The aim of this study is to examine the relationship between postoperative laboratory parameters of inflammation and the disease-free survival in patients undergoing resection for colorectal cancer. METHODS Six hundred seventy-five consecutive patients who underwent an elective resection for primary colorectal cancer from October 1999 to March 2004 were included in this study. We examined the associations between cancer recurrence and white blood cell count, lymphocyte percentage, neutrophil percentage and C-reactive protein. RESULTS Lymphocyte percentage on postoperative days 3 and 7 was significantly higher in patients without recurrence than in those with recurrence. Lymphocyte percentage on postoperative day 7 differed the most between the two groups. On postoperative day 7, Stage II patients with lymphocyte percentage >15% had significantly longer survival compared with the patients with lymphocyte percentage ≤ 15%. A multivariate analysis showed lymphocyte percentage ≤ 15% on postoperative day 7 to be an independent prognostic factor, along with lymph node metastases and serosal invasion. Logistic regression analysis showed that blood loss (>250 ml) and postoperative complications were significant independent predictors of lymphocyte percentage ≤ 15% on postoperative day 7. CONCLUSIONS Lymphocyte percentage ≤ 15% on postoperative day 7 is an independent prognostic factor for the patients undergoing a resection for colorectal cancer.


Digestive Surgery | 2012

Association between Anal Function and Therapeutic Effect after Preoperative Chemoradiotherapy followed by Intersphincteric Resection

Yuji Nishizawa; Norio Saito; Satoshi Fujii; Masaaki Ito; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa

Background/Aims: Preoperative chemoradiotherapy (CRT) for rectal cancer improves local control, but can also induce severe anal dysfunction after surgery. The goal of the study was to assess the relationship of the therapeutic effect of CRT with anal function and prognosis after intersphincteric resection (ISR). Methods: The subjects were 37 patients with lower rectal cancer who underwent ISR with preoperative CRT. The rectal cancer regression grade (RCRG) was quantified based on histologic features of surgical specimens. The relationships of RCRG with anal function (assessed by questionnaire) and incontinence (Wexner score) were examined at 12 months after surgery. Results: The median Wexner scores at 12 months after stoma closure in RCRG1, -2, and -3 cases were 18.0, 7.5, and 4.5, respectively, and anal function differed significantly among these groups (p = 0.001). Four cases had local recurrence, but 5-year local recurrence rates did not differ significantly among the groups. The 5-year disease-free survival rates were 88.9, 50.8, and 50.0% and the 5-year overall survival rates were 100, 77.3, and 66.7% in RCRG1, -2, and -3 cases, respectively, with no significant differences among the groups. Conclusion: Postoperative anal function is decreased when the effect of preoperative CRT is strong in patients treated with ISR.


Diseases of The Colon & Rectum | 2014

Clinical Impact of Elastic Laminal Invasion in Colon Cancer: Elastic Laminal Invasion-positive Stage Ii Colon Cancer Is a High-risk Equivalent to Stage Iii

Mitsuru Yokota; Motohiro Kojima; Shogo Nomura; Yusuke Nishizawa; Akihiro Kobayashi; Masaaki Ito; Atsushi Ochiai; Norio Saito

BACKGROUND: Elastic laminal invasion is defined as tumor invasion beyond the peritoneal elastic lamina. It is one of the factors affecting the prognosis of patients with colon cancer. OBJECTIVE: This study aimed to investigate the clinical impact of elastic laminal invasion in colon cancer and the magnitude of the worse prognosis of elastic laminal invasion-positive, node-negative patients. DESIGN: This was a retrospective cohort study. SETTINGS: This study reviewed data from a tertiary care cancer center in Japan. PATIENTS: The records of 436 patients with pT3 or pT4a colon cancer who underwent curative resection between January 1996 and December 2006 were reviewed. MAIN OUTCOME MEASURES: The primary outcome measure was recurrence-free survival. Cox regression analyses established the factors associated with recurrence-free survival. Six groups formed by combining the factors were compared. RESULTS: Of the patients with pT3 disease, those who were positive for elastic laminal invasion had a 5-year recurrence-free survival rate of 73.8% compared with a rate of 85.0% in those who were negative for elastic laminal invasion and 53.5% in patients with pT4 disease. Three unfavorable prognostic factors were identified, including lymph node metastasis, positive elastic laminal invasion, and a lack of adjuvant chemotherapy. Log-rank analysis revealed statistically significant differences in recurrence-free survival between group 1 (node negative, elastic laminal invasion negative, and no adjuvant chemotherapy) and group 3 (node negative, elastic laminal invasion positive, and no adjuvant chemotherapy). The HR for group 1 compared with group 3 was 0.49 (95% CI, 0.27–0.90). Furthermore, the HRs for group 2 (node positive, elastic laminal invasion negative, and received adjuvant chemotherapy) and group 4 (node positive, elastic laminal invasion positive, and received adjuvant chemotherapy) vs group 3 were 0.77 (95% CI, 0.35–1.69) and 1.36 (95% CI, 0.62–2.98). LIMITATIONS: Our study has limited prediction accuracy of our prognostic stratification, and an analysis of small subgroups may not have been capable of detecting significant differences. In addition, a wide range of hematoxylin and eosin- and elastica-stained slides were examined per case. CONCLUSIONS: Elastic laminal invasion adversely influences prognosis in pT3 and pT4a colon cancer. Although elastic laminal invasion positivity does not affect prognosis in node-positive patients receiving adjuvant chemotherapy, node-negative patients with elastic laminal invasion have a similar risk of recurrence as node-positive patients.


Surgery Today | 2013

Rectoseminal vesicle fistula as a rare complication after low anterior resection: a report of three cases

Kentaro Nakajima; Masanori Sugito; Yuji Nishizawa; Masaaki Ito; Akihiko Kobayashi; Yusuke Nishizawa; Takanori Suzuki; Toshiyuki Tanaka; Toru Etsunaga; Norio Saito

A rectoseminal vesicle fistula is a rare complication after a low anterior resection for rectal cancer, usually developing in the outpatient postoperative period with pneumaturia, fever, scrotal swelling or testicular pain. A diagnostic water-soluble contrast enema, cystography and computed tomography reveal a tract from the rectum to the seminal vesicle. Anastomotic leakage is thought to be partially responsible for the formation of such tracts. This report presents three cases of rectoseminal vesicle fistula, and the presumed course of the disease and optimal treatment options are discussed.


International Journal of Colorectal Disease | 2012

Differences in tissue degeneration between preoperative chemotherapy and preoperative chemoradiotherapy for colorectal cancer

Yuji Nishizawa; Satoshi Fujii; Norio Saito; Masaaki Ito; K. Nakajima; Atsushi Ochiai; Masanori Sugito; Akihiro Kobayashi; Yusuke Nishizawa

PurposePreoperative chemoradiotherapy (CRT) for rectal cancer is administered to improve local control, but can also induce severe anal dysfunction after surgery, while preoperative chemotherapy that significantly reduces the primary lesion in rectal cancer has recently been developed. The aim of the study was to examine differences in the effects of preoperative CRT and chemotherapy on tissue degeneration of patients with colorectal cancer.MethodsThe subjects were 91 patients, including 68 with rectal cancer who underwent internal sphincteric resection with (n = 47, CRT group) or without (n = 21, control group) preoperative CRT, and 23 with colorectal cancer who received preoperative FOLFOX treatment. Peripheral nerve degeneration was evaluated histopathologically using H&E-stained sections, based on karyopyknosis, disparity of the nucleus, denucleation, vacuolar or acidophilic degeneration of the cytoplasm, and adventitial neuronal changes.ResultsThe incidence of neural degeneration was significantly higher in the CRT group than in the control group and FOLFOX group. There were no differences in any items of neural degeneration between the FOLFOX and control groups.ConclusionCRT induced marked neural degeneration around the rectal tumor. FOLFOX treatment produced mild neural degeneration similar to that in the control group.

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Hirohiko Sakamoto

National Defense Medical College

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