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2.
DEN Open ; 2(1): e13, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35310715

RESUMEN

A 70-year-old man underwent surveillance colonoscopy following surgery for occlusive sigmoid colon cancer. The procedure revealed nine sessile serrated lesions (SSLs), including three inverted lesions. Endoscopic and surgical resections were performed. All nine lesions were confirmed pathologically as SSL, and the patient was diagnosed with serrated polyposis syndrome (SPS). Three inverted SSLs (iSSLs) showed endophytic growth without epithelial misplacement. Crypt analysis revealed that iSSL crypts were wider at the bottom than the opening, roughly resembling a frustoconical shape. Our results suggest that a horizontal arrangement of frustoconical crypts leads to hemispherical deformation of the muscularis mucosa, forming an inverted shape. This is the first report to reveal the morphogenesis of iSSLs from the shape of the crypt.

3.
Surg Today ; 52(1): 106-113, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34455492

RESUMEN

PURPOSE: To evaluate the effect of mild renal dysfunction on the clinical course after colectomy in patients with colon cancer. METHODS: The subjects of this retrospective study were 263 patients who underwent surgical resection for colon cancer at our hospital between 2011 and 2015. Renal function was assessed based on preoperative estimated glomerular filtration rate (eGFR) values. Patients were divided into groups based on their eGFR value of 55 ml/min/1.73 m2. The Mann-Whitney U test, chi-square or Fisher exact test, and log-rank test were used in the data analysis. RESULTS: There were 59 patients (22.4%) in the low eGFR group and 204 patients in the normal eGFR group. There were differences between the groups in age, comorbidities, and the levels of hemoglobin, albumin, and serum creatinine. The overall postoperative complication rate, frequency of severe complications, and length of stay were significantly higher in the low eGFR group than in the normal eGFR group. Multivariate analysis revealed that low eGFR was the only independent risk factor for severe complications (Clavien-Dindo classification III/IV). There were no differences in survival between the groups. CONCLUSION: Preoperative asymptomatic renal dysfunction may be correlated with the development of postoperative complications and a possible significant risk factor for severe complications after colon cancer surgery.


Asunto(s)
Enfermedades Asintomáticas , Colectomía , Neoplasias del Colon/cirugía , Enfermedades Renales/complicaciones , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Anciano , Anciano de 80 o más Años , Femenino , Tasa de Filtración Glomerular , Humanos , Enfermedades Renales/diagnóstico , Enfermedades Renales/fisiopatología , Masculino , Persona de Mediana Edad , Gravedad del Paciente , Periodo Preoperatorio , Pronóstico , Estudios Retrospectivos , Factores de Riesgo
4.
Int J Colorectal Dis ; 37(1): 161-170, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34599685

RESUMEN

PURPOSE: Colorectal endoscopic submucosal dissection (ESD) produces exfoliated tumor cells that occasionally cause local recurrence. However, the biological characteristics of these tumor cells have not been clarified. The aim of this study was to clarify the genetic background and viability of exfoliated tumor cells in colorectal ESDs, as well as possible method for their elimination. METHODS: Post-ESD intraluminal lavage samples from 19 patients who underwent colorectal ESDs were collected. In four patients with adenocarcinoma, gene mutations in the primary tumors and exfoliated cells in lavage samples were analyzed using a next-generation sequencer (NGS). In 15 patients with adenoma or adenocarcinoma, the viability of exfoliated cells and the cell-killing effect of povidone-iodine on exfoliated cells were evaluated. RESULTS: The analysis using a NGS demonstrated that tumors targeted for ESD had already acquired mutations in many genes involved in cell proliferation, angiogenesis, and invasions. Furthermore, gene mutations between the exfoliated tumor cells and tumors resected by ESDs showed a 92 to 100% concordance. The median viable cell counts and the median viability of exfoliated cells in intraluminal lavage samples after ESDs were 4.9 × 105 cells/mL and 24%, respectively. The viability of the exfoliated cells did not decrease even 12 h after ESD. However, contact with 2.0% povidone-iodine solution reduced both viable cell counts and viability, significantly. CONCLUSION: A large number of tumor cells exfoliated during colorectal ESDs had acquired survival-favorable gene mutations and could survive for some time. Therefore, a lavage using a solution of 2.0% povidone-iodine may be effective against such cells. TRIAL REGISTRATION: The prospective study registered 1317, and the retrospective study registered 2729. The prospective study approved on June 20, 2016, and the retrospective study approved on October 6, 2020.


Asunto(s)
Neoplasias Colorrectales , Resección Endoscópica de la Mucosa , Recuento de Células , Colonoscopía , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/cirugía , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Irrigación Terapéutica , Resultado del Tratamiento
5.
J Phys Ther Sci ; 33(9): 627-631, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34539064

RESUMEN

[Purpose] To quantitatively analyze the characteristics of movements evoked by certain motor instruction words on the basis of measurements of ankle elevation and related body movements in step-over motion tasks. [Participants and Methods] Sixty-one healthy adult participants were presented with motor instructions and asked to step over an obstacle in accordance with the instructions. The motor instructions were as follows: "Raise your XX (body part) up YY (expression)" in four combinations using "thigh" and "knee" for body part and "high" and "firmly" for expression. Using Kinect to analyze movements, ankle elevation, trunk-anteversion angle, hip-flexion angle, and knee-flexion angle were measured and statistically processed. [Results] With respect to body part, there was no significant difference in the mean and standard deviation (individual variation) values for ankle elevation. With respect to expression, hip joint and knee joint were bent significantly more for "high" than for "firmly", and although the mean value for ankle elevation was high, ankle elevation standard deviation (individual variation) values were significantly lower for "firmly" than for "high". [Conclusion] Explicit motor instruction words such as "high" may be effective in improving performance, while ambiguous motor instruction words like "firmly" may be effective in stabilizing movements.

6.
J Anus Rectum Colon ; 5(2): 158-166, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33937556

RESUMEN

OBJECTIVES: Many patients have endoscopic evidence of recurrent Crohn's disease (CD) 1 year after intestinal resection, and endoscopic lesions predict future clinical recurrence. The aim of this study was to describe some anastomotic lesions including changes in endoscopic features in CD patients and to discuss recurrence. We also compared anastomotic lesions in CD patients and in right-side colon cancer (rt-CC) patients. METHODS: We enrolled patients with CD and rt-CC who underwent surgical resection between 2008 and 2014. Eleven CD patients underwent postoperative endoscopy at least twice, with the first time being from 6 months to 1 year after surgery and the second time being from 2 to 3 years after surgery. Eighty-six patients with rt-CC underwent postoperative endoscopy after approximately one year. RESULTS: A total of 90.9% of CD patients had postoperative lesions around the anastomosis at the first postoperative ileocolonoscopy, which was markedly higher than that in rt-CC patients (3.5%, p<0.001). Many of these lesions in CD required enhanced treatment. However, linear superficial ulcers at the anastomotic line at the first ileocolonoscopy did not worsen with the same treatment (18.1%). CONCLUSIONS: Postoperative anastomotic lesions were detected at a higher rate in CD cases than that in rt-CC cases. Many anastomotic lesions were recognized as recurrent disease and required enhanced treatment, whereas linear superficial ulcers did not require treatment changes. Therefore, linear superficial ulcers might not be recurrent disease. As this issue is related to recurrence, it should be further explored with the accumulation of more cases in a multicenter analysis.

7.
Int J Colorectal Dis ; 36(8): 1677-1684, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33616737

RESUMEN

PURPOSE: Lateral lymph node (LLN) metastasis is one of the leading causes of local recurrence in patients with lower rectal cancer. Unfortunately, no diagnostic biomarkers are currently available that can predict LLN metastasis preoperatively. Accordingly, we investigated the relationship between the middle rectal artery (MRA) identified by contrast-enhanced magnetic resonance imaging (ceMRI) and LLN metastases. METHODS: Data from 102 patients with lower rectal cancer who underwent surgery, and were evaluated by preoperative ceMRI, between 2008 and 2016 were reviewed retrospectively. Two expert radiologists evaluated the MRA findings. The diagnostic performance of MRA for LLN metastasis was evaluated by a multivariate analysis with conventional clinicopathological factors. RESULTS: The MRA was detected in 67 patients (65.7%), including 32 (31.4%) with bilateral MRA and 35 (34.3%) with unilateral MRA. The tumor size, presence of the MRA, and clinical LLN status were significantly correlated with LLN metastasis. A multivariate analysis demonstrated that the presence of MRA (P = 0.045) and clinical LLN status (P = 0.001) were independent predictive factors for LLN metastasis. Furthermore, the sensitivity and negative predictive value of MRA for LLN metastasis were 95% and 97.1%, respectively. CONCLUSION: We successfully demonstrated that MRAs could be clearly detected by ceMRI, and the presence of MRA robustly predicted LLN metastasis in patients with lower rectal cancer, highlighting its clinical significance in the selection of more appropriate treatment strategies. TRIAL REGISTRATION: Trial registration number: retrospectively registered 2126 Trial registration date of registration: August 23, 2019.


Asunto(s)
Escisión del Ganglio Linfático , Neoplasias del Recto , Arterias , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/patología , Metástasis Linfática , Imagen por Resonancia Magnética , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Neoplasias del Recto/cirugía , Estudios Retrospectivos
8.
Surg Today ; 51(4): 605-611, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32888080

RESUMEN

PURPOSE: The purpose of this study was to evaluate the effectiveness of a wound closure method using a combination of subcuticular sutures and subcutaneous closed-suction drainage (SS closure) for preventing incisional surgical site infection (SSI) in loop ileostomy closure. METHODS: A total of 178 consecutive patients who underwent loop ileostomy closure at Nara Medical University Hospital between 2004 and 2018 were retrospectively assessed. The patients were divided into 2 groups: the conventional skin closure (CC) group from 2004 to 2009 (75 patients) and the SS closure (SS) group from 2010 to 2018 (103 patients). The incidence of incisional SSI was compared between the two groups, and the factors associated with incisional SSI were examined by univariate and multivariate analyses. RESULTS: Incisional SSI occurred in 7 cases (9.3%) in the CC group but was significantly reduced to only 1 case (0.9%) in the SS group (p = 0.034). In the univariate analysis, the hemoglobin levels, serum creatinine levels, and SS closure were associated with incisional SSI. SS closure was the only independent preventive factor for incisional SSI according to the multivariate analysis (hazard ratio = 0.24, p = 0.011). CONCLUSION: The combination of subcuticular sutures and subcutaneous closed-suction drainage may be a promising way of preventing incisional SSI in loop ileostomy closure.


Asunto(s)
Ileostomía/efectos adversos , Succión/métodos , Infección de la Herida Quirúrgica/etiología , Infección de la Herida Quirúrgica/prevención & control , Técnicas de Sutura , Suturas , Técnicas de Cierre de Heridas , Biomarcadores/sangre , Creatina/sangre , Femenino , Hemoglobinas , Humanos , Masculino , Estudios Retrospectivos , Riesgo , Infección de la Herida Quirúrgica/diagnóstico , Resultado del Tratamiento
9.
Ann Coloproctol ; 37(5): 326-336, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32972100

RESUMEN

PURPOSE: Primary tumor location of colon cancer has been reported to affect the prognosis after curative resection. However, some reports suggested the impact was varied by tumor stage. This study analyzed the prognostic impact of the sidedness of colon cancer in stages II, III, and liver metastasis after curative resection using propensity-matched analysis. METHODS: Right-sided colon cancer was defined as a tumor located from cecum to splenic flexure, while any more distal colon cancer was defined as left-sided colon cancer. Patients who underwent curative resection at Nara Medical University hospital between 2000 and 2016 were analyzed. RESULTS: There were 110 patients with stage II, 100 patients with stage III, and 106 patients with liver metastasis. After propensity matching, 28 pairs with stage II and 32 pairs with stage III were identified. In the patients with stage II, overall survival (OS) and recurrence-free survival (RFS) were not significantly different for right- and left-sided colon cancers. In the patients with stage III, OS and RFS were significantly worse in right-sided colon cancer. In those with liver metastasis, OS of right-sided colon cancer was significantly worse than left-sided disease, while RFS was similar. Regarding metachronous liver metastasis, the difference was observed only in the patients whose primary colon cancer was stage III. In each stage, significantly higher rate of peritoneal recurrence was found in those with right-sided colon cancer. CONCLUSION: Sidedness of colon cancer had a significant and varied prognostic impact in patients with stage II, III, and liver metastasis after curative resection.

10.
PLoS One ; 15(6): e0235279, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32598341

RESUMEN

Blue laser/light imaging (BLI) is an image-enhanced endoscopy (IEE) technique that can provide an accurate diagnosis by closely observing the surface structure of various colonic lesions. However, complete correspondence between endoscopic images and pathological images has not been demonstrated. The aim of this study was to accurately compare endoscopic images and the pathological images using a three-dimensionally (3D) reconstructed pathological model. Continuous thin layer sections were prepared from colonic tissue specimens and immunohistochemically stained for CD34 and CAM5.2. Three-dimensional reconstructed images were created by superimposing immunohistochemically stained pathological images. The endoscopic image with magnifying BLI was compared with the top view of the 3D reconstructed image to identify any one-to-one correspondence between the endoscopic images and histopathological images using the gland orifices and microvessels as a guide. Using 3D reconstructed pathological images, we were able to identify the location on the endoscope image in cases of colonic adenocarcinoma, adenoma and normal mucosa. As a result, the horizontal plane of the endoscopic image and the vertical plane of the 2D pathological specimen were able to be compared, and we successfully determined the visible blood vessel depth and performed a detailed evaluation on magnifying BLI. Examples are as follows: (1) The median vasculature depth from the mucosal surface that could be recognized as vasculature on magnifying BLI was 29.4 µm. The median depth of unrecognizable vessels on magnifying BLI was 218.8 µm, which was significantly deeper than recognizable vessels. (2) Some brownish structures were suggested to potentially be not only dense vessels, vessel expansions, corrupted vessels but also bleeding or extravasation of erythrocytes. Overall, we demonstrated a new approach to matching endoscopic images and pathological findings using a 3D-reconstructed pathological model immunohistochemically stained for CD34 and CAM5.2. This approach may increase the overall understanding of endoscopic images and positively contribute to making more accurate endoscopic diagnoses.


Asunto(s)
Adenocarcinoma/patología , Neoplasias del Colon/patología , Detección Precoz del Cáncer/métodos , Endoscopía/métodos , Imagenología Tridimensional/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen de Banda Estrecha
11.
Anticancer Res ; 40(2): 1107-1116, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32014961

RESUMEN

BACKGROUND/AIM: The aim of this study was to evaluate whether modern chemotherapy has changed characteristics of actual five-year survivors after liver resection for colorectal liver metastasis (CRLM). PATIENTS AND METHODS: The records of 210 patients, who underwent curative liver resection for CRLM at our institution between January 1990 and May 2014, were reviewed. The patients treated before 2004 when modern chemotherapy was not introduced were compared with the patients treated after 2005. RESULTS: Actual five-year survivor rates were significantly higher after 2005 (33.3% vs. 49.0%, p=0.022). Preoperative characteristics of actual five-year survivors were not different. The median survival time after non-resectable recurrence was significantly longer after 2005 (20.3 vs. 8.7 months, p=0.002). The proportion of 5-year survivors with recurrent site was significantly higher after 2005 (34.0% vs. 10.5%, p=0.019). CONCLUSION: Actual five-year survivors have increased by modern chemotherapy. However, approximately one-third of them were not cured.


Asunto(s)
Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor , Quimioterapia Adyuvante , Neoplasias Colorrectales/terapia , Terapia Combinada , Femenino , Hepatectomía/efectos adversos , Hepatectomía/métodos , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Pronóstico , Tomografía Computarizada por Rayos X
12.
J Gastrointest Cancer ; 51(1): 1-9, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30474795

RESUMEN

BACKGROUND: Patients with Crohn's disease (CD) are generally known to be at an increased risk of cancer. The anorectal area is the most frequent cancer site in Japanese CD patients. However, the risks are not well defined. The aim of this study was to clarify the clinicopathological characteristics of Japanese CD-associated anorectal carcinoma patients and to explore screening methods for the detection of cancer at earlier stages. METHODS: A systematic review of case series and reports of Japanese CD-associated anorectal cancer patients published between 1983 and 2016 was conducted. RESULT: There were 144 cases of cancer arising from anorectal lesions of CD. The median duration from the onset of CD to the cancer diagnosis was approximately 17 (0-39) years. The most prevalent histological type of cancer was mucinous carcinoma (49.3%), and 82.1% of patients were over T3 invasion. There were only 15.6% cases with early stage disease. A total of 82% patients had enhanced symptoms, whereas 56.3% of the early cancer cases had no symptomatic changes. Approximately 90% of cases were diagnosed preoperatively, and almost all early cancer patients were diagnosed with colonoscopy. The 5-year overall survival rate was 35.8%. CONCLUSION: CD-associated anorectal carcinoma had a poor prognosis due to the advanced stage of the cases and aggressive histological features. As earlier-stage cancer is associated with a better prognosis than advanced stage disease, and it is also typically diagnosed by colonoscopy, surveillance colonoscopy may therefore help to improve the prognosis in cases without any symptomatic changes.


Asunto(s)
Neoplasias del Ano/etiología , Enfermedad de Crohn/complicaciones , Neoplasias del Recto/etiología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias del Ano/mortalidad , Neoplasias del Ano/patología , Enfermedad de Crohn/patología , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias del Recto/mortalidad , Neoplasias del Recto/patología , Análisis de Supervivencia
13.
Surg Case Rep ; 5(1): 61, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30989424

RESUMEN

BACKGROUND: Solitary adrenal metastasis from colorectal cancer is rare. Adrenal metastasis is usually detected with synchronous multiple metastases in other organs and is, therefore, considered to be unsuitable for surgical resection. The long-term outcomes of patients with solitary adrenal metastasectomy from colorectal cancer have been reported; however, the survival advantage has not been established. We herein report two cases of curative adrenal resection in patients with solitary adrenal metastasis from colorectal cancer who achieved long-term survival of > 9 years without recurrence after surgical resection. CASE PRESENTATION: The first case involved a 71-year-old man who underwent abdominoperineal rectal resection for rectal cancer. Preoperative CT revealed a mass in the right adrenal, which was growing after surgery. After chemotherapy the adrenal mass decreased in size, and adrenalectomy was performed at 8 months after the first surgery. A pathological examination confirmed metastasis from rectal cancer. The patient received adjuvant chemotherapy and is currently alive without recurrence at 9 years after the adrenalectomy. The second case involved a 53-year-old man who underwent sigmoidectomy for sigmoid colon cancer. Four years later, lobectomy was performed for isolated lung metastasis. Twenty months later, PET-CT revealed solitary metastasis in the left adrenal gland and adrenalectomy was performed. A histopathological examination revealed metastatic adenocarcinoma of sigmoid cancer. Postoperative chemotherapy was administered after adrenalectomy and the patient is currently alive and apparently disease-free at more than 9 years after undergoing adrenal metastasectomy. CONCLUSION: Curative resection for solitary adrenal metastasis from colorectal cancer may be beneficial for survival.

14.
Surg Case Rep ; 4(1): 63, 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-29943205

RESUMEN

BACKGROUND: Anal gland carcinoma with perianal Paget's disease is rare, and anal gland carcinoma in situ is extremely rare. No cases of anal gland carcinoma in situ with pagetoid spread have been previously reported. CASE PRESENTATION: Physical examination in a 75-year-old woman revealed an erythematous, inflamed, perianal skin lesion. Neither colposcopy, cystoscopy, colonoscopy, computed tomography, nor magnetic resonance imaging showed evidence of malignant genitourinary or gastrointestinal lesions. Histopathological examination of a biopsy specimen showed many Paget's cells in the perianal skin lesion and no malignant cells in the rectal or vaginal mucosa. Therefore, primary extramammary Paget's disease of the anogenital region was suspected, and we performed anus-preserving wide local excision. However, immunohistochemistry revealed a diagnosis of secondary extramammary Paget's disease due to adenocarcinoma arising from the anal gland. We therefore proceeded with a radical operation. Histopathological examination showed no residual cancer cells. The final diagnosis was anal gland adenocarcinoma in situ with pagetoid spread in the perianal skin. CONCLUSIONS: This is the first case report of anal gland adenocarcinoma in situ with pagetoid spread. We recommend immunohistochemical analysis of biopsy and locally resected specimens to obtain an accurate diagnosis and determine the appropriate treatment when there is no visible tumor.

15.
J Anus Rectum Colon ; 2(3): 97-102, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31559350

RESUMEN

OBJECTIVES: With endoscopic submucosal dissection and laparoscopic surgery, treatment for colorectal neoplasms has become minimally invasive. However, few studies have compared endoscopic submucosal dissection with laparoscopic surgery for colorectal neoplasms, excluding deeply invasive cancer on preoperative diagnosis. METHODS: We retrospectively reviewed the files of patients who had undergone endoscopic submucosal dissection or laparoscopic surgery for colorectal neoplasms between November 2005 and December 2015. We limited patients who were not suspected preoperatively to have aggressive submucosal invasion >1,000 µm. RESULTS: Ninety-five patients underwent endoscopic submucosal dissection and 37 underwent laparoscopic surgery. Cases of endoscopic submucosal dissection tended to involve rectal neoplasms more often than colonic neoplasms, shorter operative times, and shorter lengths of hospital stay compared with laparoscopic surgery. The perforation rate during colonic endoscopic submucosal dissection in the early period (November 2005 to December 2010) and late period (January 2011 to December 2015) was 14.8% and 2.9%, respectively. In all cases of perforation during colonic endoscopic submucosal dissection, the ability to maneuver the endoscope was compromised. Though tumors were larger in patients who underwent rectal endoscopic submucosal dissection compared with colonic endoscopic submucosal dissection, the perforation and postoperative bleeding rates with rectal endoscopic submucosal dissection were both 3.2%. The most common indication for laparoscopic surgery was difficulty performing endoscopic submucosal dissection. Serious complications were rare. CONCLUSIONS: For colonic neoplasms, laparoscopic surgery should be considered when endoscopic submucosal dissection is technically difficult in the early period. For rectal neoplasms, endoscopic submucosal dissection is desirable even for those of large size.

16.
J Mech Behav Biomed Mater ; 78: 1-9, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29128693

RESUMEN

Selective laser melting (SLM) technology was recently introduced to fabricate dental prostheses. However, the fatigue strength of clasps in removable partial dentures prepared by SLM still requires improvement. In this study, we attempted to improve the fatigue strength of clasps by adding support structures for overhanging parts, which can generally be manufactured at an angle to be self-supporting. The results show that the fatigue strength of the supported specimens was more than twice that of unsupported specimens. Electron back-scattered diffraction analysis revealed that the supported specimens exhibited lower kernel average misorientation values than the unsupported specimens, which suggested that the support structure reduced the residual strain during the SLM process and helped to prevent micro-cracks led by thermal distortion. In addition, the supported specimens cooled more rapidly, thereby forming a finer grain size compared to that of the unsupported specimens, which contributed to improving the fatigue strength. The results of this study suggest that the fatigue strength of overhanging parts can be improved by intentionally adding support structures.


Asunto(s)
Abrazadera Dental , Rayos Láser , Fenómenos Mecánicos , Diseño de Prótesis , Análisis de Elementos Finitos , Ensayo de Materiales , Estrés Mecánico , Propiedades de Superficie
17.
J Mech Behav Biomed Mater ; 59: 446-458, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26974490

RESUMEN

We aimed to investigate the fatigue strength of Co-Cr-Mo clasps for removable partial dentures prepared by selective laser melting (SLM). The Co-Cr-Mo alloy specimens for tensile tests (dumbbell specimens) and fatigue tests (clasp specimens) were prepared by SLM with varying angles between the building and longitudinal directions (i.e., 0° (TL0, FL0), 45° (TL45, FL45), and 90° (TL90, FL90)). The clasp specimens were subjected to cyclic deformations of 0.25mm and 0.50mm for 10(6) cycles. The SLM specimens showed no obvious mechanical anisotropy in tensile tests and exhibited significantly higher yield strength and ultimate tensile strength than the cast specimens under all conditions. In contrast, a high degree of anisotropy in fatigue performance associated with the build orientation was found. For specimens under the 0.50mm deflection, FL90 exhibited significantly longer fatigue life (205,418 cycles) than the cast specimens (112,770 cycles). In contrast, the fatigue lives of FL0 (28,484 cycles) and FL45 (43,465 cycles) were significantly shorter. The surface roughnesses of FL0 and FL45 were considerably higher than those of the cast specimens, whereas there were no significant differences between FL90 and the cast specimens. Electron backscatter diffraction (EBSD) analysis indicated the grains of FL0 showed preferential close to <001> orientation of the γ phase along the normal direction to the fracture surface. In contrast, the FL45 and FL90 grains showed no significant preferential orientation. Fatigue strength may therefore be affected by a number of factors, including surface roughness and crystal orientation. The SLM process is a promising candidate for preparing tough removable partial denture frameworks, as long as the appropriate build direction is adopted.


Asunto(s)
Aleaciones de Cromo , Abrazadera Dental , Análisis del Estrés Dental , Dentadura Parcial Removible , Aleaciones Dentales , Ensayo de Materiales , Propiedades de Superficie , Resistencia a la Tracción
18.
Gan To Kagaku Ryoho ; 43(12): 1736-1738, 2016 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-28133115

RESUMEN

A 75-year-old man was diagnosed with sigmoid colon cancer with multiple liver metastases at our hospital in May 2010. He underwent mFOLFOX6 and panitumumab chemotherapy for 6 months. He then underwent sigmoidectomy, lymphadenectomy D3, partial resection of 2 parts of S6, and cholecystectomy in January 2011. However, he underwent partial resection of the liver an additional 4 times in the 5 years followingthe primary operation. Despite multiple liver metastases, he is alive 5 years after the primary operation, havingsurvived 5 hepatectomies for multiple resectable liver metastases.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias del Colon Sigmoide/tratamiento farmacológico , Anciano , Anticuerpos Monoclonales/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Colectomía , Fluorouracilo/administración & dosificación , Hepatectomía , Humanos , Leucovorina/administración & dosificación , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/cirugía , Masculino , Compuestos Organoplatinos/administración & dosificación , Panitumumab , Neoplasias del Colon Sigmoide/patología , Neoplasias del Colon Sigmoide/cirugía , Resultado del Tratamiento
19.
Surg Endosc ; 30(7): 2773-8, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26487195

RESUMEN

BACKGROUND: Endoscopic submucosal dissection (ESD) involves dissection of tumors and manipulation of them in an exposed condition for prolonged periods. A large number of tumor cells are exfoliated into the intestinal lumen after colorectal ESD. The aim of this study was to determine whether lavage volume has an influence on tumor cell clearance after colorectal ESD. METHODS: Twenty patients who underwent colorectal ESD at our hospital between July 2013 and December 2014 were studied. Cytological examination of intraluminal lavage samples associated incremental increases in lavage volume was collected. This prospective study was approved by the ethics committee of our hospital. RESULTS: No patients had exfoliated tumor cells in their samples before ESD. Four patients (20 %) had exfoliated tumor cells in their samples after lavage with 500 ml, while one patient (5 %) had exfoliated tumor cells after lavage with 1000 or 1500 ml. CONCLUSION: Tumor cells are exfoliated into the intestinal lumen by tumor manipulation during colorectal ESD. There seems to be a risk for implantation after ESD, as well as rectal surgery. Sufficient intraluminal lavage of more than 1000 ml may be desirable to remove exfoliated tumor cells after colorectal ESD.


Asunto(s)
Adenocarcinoma/cirugía , Neoplasias Colorrectales/cirugía , Resección Endoscópica de la Mucosa/métodos , Mucosa Intestinal/cirugía , Siembra Neoplásica , Irrigación Terapéutica/métodos , Anciano , Anciano de 80 o más Años , Técnicas Citológicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
20.
Ann Surg Oncol ; 23 Suppl 2: S266-74, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25801355

RESUMEN

PURPOSE: In laparoscopic colorectal cancer (Lap-CRC) surgery, determination of a suitable mesentery division line and the appropriate degree of lymphadenectomy by tracing the blood supply is critical. We performed visualization of the lymph and blood flow by laparoscopic indocyanine green (ICG) fluorescence imaging (Lap-IGFI). METHODS: ICG is injected into the submucosa near the tumor via colonoscopy, and the lymph flow is observed. Intestinal blood flow is evaluated by administering ICG intravenously. RESULTS: For lymph flow, visualization of the main lymph node basin helped to determine the surgical division line for cases in which the blood flow was not completely visualized. Lap-IGFI changed the surgical plan of the lymphadenectomy in 23.5 %. In our experience, the metastatic rate of ICG-positive nodes was 10.0 %, and the metastatic rate of ICG-negative nodes was 5.3 %. Furthermore, there were no metastatic nodes that were ICG negative more than 5 cm from the tumor. For blood flow, the blood flow distribution of the intestinal wall from the last branch of the vasa recta of the anastomotic site was clearly visualized and proved useful in choosing the extent of intestinal resection. Lap-IGFI changed the surgical plan of the extensive intestinal resection in 16.7 %. CONCLUSIONS: Lap-IGFI can noninvasively provide detailed lymph and blood flow information and is a useful device to aid in the accurate identification of individual patients' lymph drainage. This helps dictate adequate lymphadenectomy and the extent of intestinal resection in Lap-CRC surgery.


Asunto(s)
Neoplasias Colorrectales/patología , Verde de Indocianina , Laparoscopía , Escisión del Ganglio Linfático , Imagen Óptica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/irrigación sanguínea , Neoplasias Colorrectales/cirugía , Colorantes , Femenino , Fluorescencia , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Biopsia del Ganglio Linfático Centinela
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