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Dive into the research topics where Kosaku Maeda is active.

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Featured researches published by Kosaku Maeda.


European Journal of Pediatric Surgery | 2015

Clinical Features of Congenital Cystic Lung Diseases: A Report on a Nationwide Multicenter Study in Japan.

Tatsuo Kuroda; Eiji Nishijima; Kosaku Maeda; Yasushi Fuchimoto; Seiichi Hirobe; Yuko Tazuke; Kumiko Nozawa; Kentaro Matsuoka; Noriaki Usui

AIM The current study aimed to assess the perinatal risk of congenital cystic lung diseases (CCLD) and to establish a suitable surgical strategy in consideration of postoperative lung growth and problems during adulthood. METHODS Among 874 CCLD patients identified in a nationwide survey, 428 patients were born between 1992 and 2012 and treated at 10 high-volume centers were retrospectively reviewed with statistical analysis. RESULTS In the 194 patients who were prenatally diagnosed to have CCLD, 16.7% presented with fetal hydrops as observed using ultrasonography. The Apgar score (5 minutes) was lower than 5 in 5.4%. As of postnatal day 30, 14.0% of the neonatal patients required respiratory support, and 3.3% (8/243) had died because of pulmonary hypoplasia. Among those who were asymptomatic immediately after birth, 33.6% of the patients developed the respiratory infectious symptoms during their first year of life, and 22.1% did so between the age of 1 and 2 years. The postoperative percent vital capacity among the prenatally diagnosed patients was significantly higher than that among the postnatally diagnosed patients (98.3 ± 11.9 vs. 81.7 ± 9.7, p < 0.0222). Late complications included thoracic deformity in 30 patients and persistent lung cyst in 4 patients, whereas malignancy was not observed in the present series. CONCLUSIONS Approximately 10 to 15% of prenatally diagnosed CCLD patients may carry a high risk of perinatal respiratory distress. Early operation before developing episodes of lung infection, seem to be associated with a better development of the reserved lung during later life. The incidence of carcinogenesis among patients with CCLD may be extremely low.


Pediatric Surgery International | 2017

Predictive factor for intraoperative tumor rupture of Wilms tumor

Hiroaki Fukuzawa; Yuko Shiima; Yasuhiko Mishima; Sachi Sekine; Shizu Miura; Kiyoaki Yabe; Satoshi Yamaki; Keiichi Morita; Yuichi Okata; Chieko Hisamatsu; Makoto Nakao; Akiko Yokoi; Kosaku Maeda; Yoshiyuki Kosaka

PurposeFor Wilms tumor, intraoperative tumor rupture with wide tumor spillage during surgical manipulation raises the classification to stage 3. Then, postoperative chemotherapy must be more intensive, and abdominal radiotherapy is added. Therefore, intraoperative tumor rupture should be avoided if possible. However, predictive factors for intraoperative tumor rupture have not been sufficiently described. Here we examined the risk factors for intraoperative tumor rupture.MethodsPatients with Wilms tumor who underwent treatment according to the National Wilms Tumor Study or the Japanese Wilms Tumor Study protocol at our institution were reviewed retrospectively. Collected cases were categorized into two groups: the ruptured group and the non-ruptured group. Risk factors for intraoperative tumor rupture, including the ratio of the tumor area to the abdominal area in a preoperative single horizontal computed tomography slice (T/A ratio), were investigated in both groups.ResultsThe two groups were not different in age, body weight, tumor laterality, sex, or histological distribution. The T/A ratio in the ruptured group was significantly higher than that in the non-ruptured group. Receiver operating characteristic curve analysis identified a discriminative value for a T/A ratio >0.5.ConclusionThe T/A ratio can be a predictive factor for intraoperative tumor rupture of Wilms tumor.


Pediatric Surgery International | 2017

Pediatric airway surgery

Kosaku Maeda

Pediatric airway surgery is a challenging field in pediatric surgery. Laryngotracheal stenosis has a variety of congenital and acquired conditions that require precise assessment and tailored treatment for each individual patient. About 90% of acquired conditions are represented by subglottic stenosis (SGS) resulting as a complication of tracheal intubation. Congenital tracheal stenosis (CTS) is a rare and life-threatening malformation, usually associated with complete tracheal rings along a variable length of the trachea. Tracheomalacia (TM) is a process characterized by flaccidity of the supporting tracheal cartilage, widening of the posterior membranous wall, and reduced anterior-posterior airway caliber. The clinical presentation can vary from almost asymptomatic patients to near fatal airway obstruction. There is considerable variation in both the morphologic subtypes and the prognosis of pediatric airway. The patients are divided into three clinical groups (mild, moderate, and severe). A further division was proposed according to the presence or absence of associated anomalies. The definitive diagnosis of pediatric airway was made by means of rigid bronchoscope and computed tomography scan with three-dimensional reconstruction (3D-CT). Rigid bronchoscopy and 3D-CT confirmed the diagnosis in all the cases. Other associated anomalies include congenital heart disease, vascular anomalies, and BPFM (maldevelopment of aerodigestive tract). After definitive diagnosis of pediatric airway lesions, surgical intervention should be considered. Surgical strategy was presented on each lesion.


Pediatric Surgery International | 2018

Bronchoscopic assessments and clinical outcomes in pediatric patients with tracheomalacia and bronchomalacia

Yuichi Okata; Tomomi Hasegawa; Yuko Bitoh; Kosaku Maeda

BackgroundTracheomalacia and bronchomalacia (TM/BM) are one of the serious causes of airway obstruction in infants and children. This study reviewed our bronchoscopic assessments and clinical outcomes in pediatric patients with TM/BM, and investigated risk factors of surgical intervention for TM/BM.MethodsFifty-seven consecutive patients who were diagnosed as TM/BM by bronchoscopy between 2009 and 2013 were reviewed retrospectively. They were divided into two groups according to the presence (group E, n = 26) or absence (group N, n = 31) of acute life-threatening events and extubation failure (ALTE/EF). The severity of TM/BM was evaluated by Oblateness Index which was obtained from bronchoscopic images.ResultsOblateness Index was significantly higher in Group E than in Group N. Patients in Group E underwent surgical intervention for TM/BM more frequently, and had significantly longer intubation period and hospital stay. Clinical symptoms of ALTE/EF, Oblateness Index ≥ 0.70, and multiple malacic lesions were significant risk factors indicating surgical events in patients with TM/BM.ConclusionsPatients with TM/BM who had ALTE/EF had more severe malacic lesions indicating surgical intervention, and worse clinical outcomes. Oblateness Index is a simple and semi-quantitative index for bronchoscopic assessment of TM/BM, and can be one of the prognostic tools to predict clinical severity of pediatric TM/BM.


Pediatrics International | 2015

Brain abscess in hepatopulmonary syndrome associated with biliary atresia

Keiichi Morita; Hiroaki Fukuzawa; Kosaku Maeda

The first‐choice therapy for biliary atresia (BA) is Kasai hepatoportoenterostomy, which has been shown to greatly improve outcome. Various long‐term complications, however, such as portal hypertension and hepatopulmonary syndrome (HPS), can occur in patients with native liver. A rare case of brain abscess in an 11‐year‐old girl with HPS associated with BA is reported. The patient underwent hepatoportoenterostomy for BA at 53 days of age, with resolution of hyperbilirubinemia. At 10 years of age, she was diagnosed with severe HPS with right‐to‐left shunting, and preparations for liver transplantation proceeded. Three months after the diagnosis, she had a right parietal brain abscess. Given that the brain abscess enlarged in size, surgical drainage of the brain abscess was performed. The postoperative course was uneventful, but a slight left hemiplegia remained at discharge. The presumed mechanism of abscess formation in HPS may be right‐to‐left bacterial transit through intrapulmonary vascular dilatations and/or arteriovenous fistulae.


Asian Journal of Endoscopic Surgery | 2015

Thoracoscopic repair of a large neonatal congenital diaphragmatic hernia using Gerota's fascia

Hiroaki Fukuzawa; Akihiko Tamaki; Jyunkichi Takemoto; Keiichi Morita; Kosuke Endo; Tamaki Iwade; Okata Yuichi; Yuko Bitoh; Akiko Yokoi; Kosaku Maeda

A large congenital diaphragmatic hernia needing patch repair has a high risk of recurrence. Thus, managing these large congenital diaphragmatic hernias under thoracoscopy has become a problem. Here, a large congenital diaphragmatic hernia that was repaired using Gerotas fascia under thoracoscopy is reported. In the present case, it was impossible to close the hernia directly under thoracoscopy because the hernia was too large. Gerotas fascia was raised up by the left kidney and used for the repair. The left colon adhering to Gerotas fascia was mobilized, and a large space was made under thoracoscopy. Gerotas fascia was fixed to the diaphragmatic defect. The patients postoperative course was good, and there was no recurrence. This technique could be one option for repairing a large hernia under thoracoscopy.


Experimental and Therapeutic Medicine | 2017

3‑Dimensional computed tomography imaging of the ring‑sling complex with non‑operative survival case in a 10‑year‑old female

Hironobu Fukuda; George Imataka; Fabrizio Drago; Kosaku Maeda; Shigemi Yoshihara

We report a case of a 10-year-old female patient who survived ring-sling complex without surgery. The patient had congenital wheezing from the neonatal period and was treated after a tentative diagnosis of infantile asthma. The patient suffered from allergy and was hospitalized several times due to severe wheezing, and when she was 22 months old, she was diagnosed with ring-sling complex. We used a segmental 4 mm internal diameter of the trachea for 3-dimensional computed tomography (3D-CT). Bronchial asthma is considered an exacerbating factor in infantile period and frequently required treatment with bronchodilator. After the age of 10, the patient had recurrent breathing difficulties during physical activity and during night time, and this condition was assessed to be related to the pressure from the blood vessel on the ring. We repeated the 3D-CT evaluation later and discovered that the internal diameter of the trachea had grown to 5 mm. Eventually, patients breathing difficulties disappeared after the treatment of bronchial asthma and restriction of physical activities. Our patient remained in stable condition without undergoing any surgical procedures even after she passed the age of 10.


Fetal and Pediatric Pathology | 2015

Pathological Features of the Unilateral Favorable Histology Nephroblastoma with Relapse

Hiroaki Fukuzawa; Takeshi Aoba; Makiko Yoshida; Hideto Iwafuchi; Junki Koike; Hiroaki Kitagawa; Naoto Urushihara; Akiko Yokoi; Kosaku Maeda

Purpose: To evaluate the pathological features of the primary lesion in patients with relapse of unilateral favorable histology nephroblastoma. Material and Methods: Fifty-eight patients with unilateral favorable histology nephroblastoma who underwent initial nephrectomy before chemotherapy were categorized into one of two groups: the nonrelapsed group (n = 52) and the relapsed group (n = 6). The histological subtypes of both groups and pathological features of the relapsed group were re-evaluated retrospectively. Results: The histological subtypes of all relapsed cases were classified as blastemal predominant. In three of six cases with relapse, sheets of spindle-shaped blastemal cells that were histologically reminiscent of synovial sarcoma were predominant (massive sarcomatoid pattern). Conclusions: The histological blastemal predominant subtype of nephroblastoma is a strong indicator of relapse. In particular, the blastemal predominant subtype with massive sarcomatoid pattern may have a higher risk of relapse.


Pediatric Surgery International | 2016

Evaluation of the intraoperative risk factors for esophageal anastomotic complications after primary repair of esophageal atresia with tracheoesophageal fistula

Yuichi Okata; Kosaku Maeda; Yuko Bitoh; Yasuhiko Mishima; Akihiko Tamaki; Keiichi Morita; Kosuke Endo; Chieko Hisamatsu; Hiroaki Fukuzawa; Akiko Yokoi


Pediatric Surgery International | 2015

Severe acquired subglottic stenosis in children: analysis of clinical features and surgical outcomes based on the range of stenosis

Keiichi Morita; Akiko Yokoi; Yuko Bitoh; Hiroaki Fukuzawa; Yuichi Okata; Tamaki Iwade; Kosuke Endo; Junkichi Takemoto; Akihiko Tamaki; Kosaku Maeda

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Akiko Yokoi

Boston Children's Hospital

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Hiroaki Fukuzawa

Boston Children's Hospital

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Keiichi Morita

Boston Children's Hospital

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Yuichi Okata

Boston Children's Hospital

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Akihiko Tamaki

Boston Children's Hospital

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Kosuke Endo

Boston Children's Hospital

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Yasuhiko Mishima

Boston Children's Hospital

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Yuko Bitoh

Boston Children's Hospital

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Chieko Hisamatsu

Boston Children's Hospital

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Makiko Yoshida

Boston Children's Hospital

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