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Hiroaki Komuro

Publications and source records attributed to Hiroaki Komuro.

9 recordsLinked to original sources
PubMed2007

Regeneration of the esophagus using gastric acellular matrix: an experimental study in a rat model.

Recently, tissue engineering of the autologous esophagus has been thought to provide a promising strategy for esophageal substitution. In this study, gastric acellular matrix (GAM) was used as a scaffold for regeneration of the esophagus in a rat model. Usage of GAM has an advantage that naturally derived extracellular matrix autograft can be prepared less invasively in a clinical setting. Twenty-seven F344 female rats were used as recipients. Patch defects created in the abdominal esophagus were replaced by GAM patch grafts. The rats were sacrificed 1 week to 18 months after implantation. The specimen was examined macroscopically as well as microscopically. 5'-Bromo-2'-deoxyuridine (BrdU) proliferation assay was performed in six rats that were sacrificed 1, 2, and 4 weeks after implantation. Twenty-four rats survived without complications. The graft site did not show esophageal stenosis or dilatation in any rat. Keratinized stratified squamous esophageal mucosa was regenerated in the entire graft 2 weeks after implantation. Regeneration of the muscle layer or lamina muscularis mucosae in the graft site was not observed even 18 months after implantation. Marked incorporation of BrdU was observed only in the mucosal layer but not in the muscle layer. GAM patch graft provided satisfactory mucosal regeneration of the esophagus without stenosis or dilatation, although muscle regeneration was still a future challenge.

Animals↗
PubMed2005

Rare association of severe hypoplasia of the abdominal aorta with imperforate anus, colonic atresia, and choledochal cyst.

Hypoplasia of the abdominal aorta (HAA) is a rare condition that causes marked hypertension. Although multiple etiologies have been postulated for HAA, congenital structural anomalies are rarely observed except in cases associated with some hereditary syndromes. The authors describe a neonatal case with HAA complicated by multiple anomalies including colonic atresia (CA), imperforate anus, choledochal cyst, facial cleft, and brain defects. This patient showed CA in the descending colon and caliber change in the transverse colon mimicking Hirschsprung disease, both of which were thought to be caused by vascular insult to the mesentery due to HAA. Although multiple surgical corrections were successfully performed, the hypertension was uncontrollable.

Abnormalities, Multiple↗
PubMed2005

Perforation of the colon in neonates.

PURPOSE: Gastrointestinal perforation is a catastrophic condition in neonates, especially in premature neonates. Although perforation is commonly observed in the small intestine during the neonatal period, perforation of the colon is a rare condition. This study analyzed the clinical findings and results of perforation of the colon in neonates. METHODS: Between 1989 and 2004, 8 neonates were treated for spontaneous perforation of the colon at our institute. These patients were retrospectively reviewed. RESULTS: Gestational ages ranged from 36 to 41 weeks. Seven patients weighed above 2500 g, whereas one patient weighed 1800 g at birth. Perforations developed within 7 days after birth in 6 patients and before birth in two. Associated bowel diseases included rectosigmoid type of Hirschsprung's disease in two patients, immature ganglia in one, imperforate anus in one, colonic atresia in one, and necrotizing enterocolitis in one. An obvious cause was not identified in the remaining two. Six patients without definite anatomic obstructions, such as imperforate anus or colonic atresia, required evaluations for suspected Hirschsprung's disease. All 8 patients underwent colostomy and recovered from peritonitis. Seven survived, but one died of sudden infant death syndrome. CONCLUSIONS: In this study, perforation of the colon during the neonatal period mostly occurred in term or near-term neonates and carried a good prognosis. During management, it was important to identify Hirschsprung's and its allied disorders as a cause of perforation.

Colonic Diseases↗
PubMed2004

Placental vascular compromise in jejunoileal atresia.

BACKGROUND/PURPOSE: The mechanisms of intrauterine vascular disruptions that result in the development of jejunoileal atresia (JIA) are not fully understood. Monochorionic twinning with fetal death of a cotwin is known to be correlated with the development of JIA in the survivor through placental communication. The aim of this study was to evaluate whether other placental vascular compromises might contribute to the development of JIA. METHODS: Forty-five newborns (23 boys and 22 girls) who were treated for JIA at Tsukuba University Hospital from 1978 to 2003 were reviewed. Placental findings were informative in 23 cases. RESULTS: No or slight abnormality of the placenta was found in 19 cases. Significant placental abnormalities were found in 4 patients who also had a low birth weight. One patient with apple peel atresia (APA) had excessive torsion of the umbilical cord (UC), which was inserted at the margin of the placenta, and there was an adjacent area of infarction. One patent with multiple atresia (MA) was a surviving monochorionic twin with intrauterine fetal death of the other. Another case of MA showed marginal insertion of the UC. Severe placental abnormalities including wide infarction, cyst formation, and marginal insertion of the UC were found in 1 case of MA. These 3 cases of MA were complicated with other anomalies including brain anomaly. CONCLUSIONS: Placental vascular compromises were involved infrequently in JIA but might possibly be responsible for the development of JIA as well as associated anomalies and a low birth weight as chronic insults since an early stage of gestation in some cases.

Female↗
PubMed2004

The etiologic role of intrauterine volvulus and intussusception in jejunoileal atresia.

PURPOSE: Although intussusception has been reported as quite a rare cause of jejunoileal atresia (JIA), pediatric surgeons have noted the frequent presence of intussusception as well as volvulus at surgery. The aim of this study was to investigate the contribution of intrauterine intussusception and volvulus to the development of JIA. METHODS: In 48 newborns (24 boys and 24 girls) treated for JIA at our hospital between 1978 and 2004, the operative and pathologic findings were reviewed. RESULTS: Intussusception was responsible for gap and cord type atresia in 12 cases (25%). The cord showed an atrophic intestinal lumen in 2 cases. Volvulus was observed in 13 cases. Volvulus and intussusception were simultaneously noted in 1 case. This suggested that intussusception was the cause of the atresia, whereas volvulus was a secondary event. Neither intussusception nor volvulus was observed in high jejunal, apple peel, or multiple atresia. CONCLUSIONS: Intrauterine volvulus and intussusception were commonly observed in single mid- and low JIA. Thus, intrauterine intussusception may be a common cause of gap and cord type JIA. Volvulus may not only cause JIA but also result from anatomic changes after the development of JIA in some cases.

Female↗
PubMed2003

Aneurysm of the superficial femoral artery in an infant.

An isolated arterial aneurysm in childhood is extremely rare. We report a 1-year-old girl with an aneurysm of the right superficial femoral artery, presenting as an asymptomatic mass of the thigh. The aneurysm involved the whole superficial femoral artery (9 cm in length), and surgical treatment would have required replacement of the affected artery. Conservative treatment was chosen, influenced by the patient's rapid growth at that time. Non-invasive, 3-D contrast-enhanced magnetic resonance angiography (MRA) was useful as an alternative to conventional angiography for detailed evaluation of the femoral arteries, including the aneurysm.

Aneurysm↗
PubMed2003

Tissue-engineered urinary bladder wall using PLGA mesh-collagen hybrid scaffolds: a comparison study of collagen sponge and gel as a scaffold.

PURPOSE: Tissue engineering of the urinary bladder using autologous cells and biodegradable scaffold is a promising method for augmentation. The authors developed 2 hybrid scaffolds by combining poly (DL-lactic-co-glycolic acid; PLGA) mesh for mechanical strength with collagen sponge or gel suitable for cell seeding. The aim of this study was to compare collagen as a scaffold between collagen sponge and gel and to construct a tissue-engineered urinary bladder wall utilizing these hybrid scaffolds. METHODS: The PLGA mesh-collagen hybrid scaffolds were prepared by introducing collagen sponge or gel into the PLGA knitted mesh. Urothelial and smooth muscle cells were obtained from porcine urinary bladder wall and were cultured in their respective media. The cells were seeded on these hybrid scaffolds. These constructs were analyzed morphologically and immunohistochemically. RESULTS: The urothelial layer was generated 3 dimensionally by culturing urothelial cells with PLGA mesh and collagen sponge. The smooth muscle layer was constructed by culturing smooth muscle cells with PLGA mesh and collagen gel. And a novel tissue-engineered urinary bladder wall was constructed laminating the urothelial and smooth muscle layers. CONCLUSIONS: Ex vivo construction of urinary bladder wall using hybrid scaffolds prepared by combining PLGA mesh with collagen sponge or gel was successful. This tissue-engineered urinary bladder wall allows easy handling and may become a promising tool for bladder augmentation.

Absorbable Implants↗
PubMed2002

Application of collagen sponge scaffold to muscular defects of the esophagus: an experimental study in piglets.

BACKGROUND/PURPOSE: Circular myotomy often has been used to elongate the esophagus in end-to-end anastomosis for esophageal atresia with a long gap. Defects of the muscular layer often have led to the ballooning of the esophagus during the postoperative course. Recently, successful regeneration of the neo-esophagus using collagen sponge scaffold (CSS) for self-tissue regeneration has been reported. The authors applied this CSS to the muscular defect after circular myotomy in animal experiments. METHODS: Myectomy or myotomy of the cervical or thoracic esophagus was performed in 11 piglets. CSS was applied to the amuscular site, which was 20 to 30 mm in length, to examine the regeneration of the muscular layer in 8 piglets (CSS group). The amuscular site was not wrapped by CSS in 3 piglets as a control (control group). Two months after operation, the animals were killed, and their operated esophagi were examined macroscopically and microscopically. RESULTS: All 11 piglets increased in weight normally without any sign of dysphagia or vomiting. The amuscular site onto which CSS was implanted was covered with loose connective tissue, but muscle regeneration was not found microscopically. The amuscular site, which had been wrapped by CSS, was not distended in any of the 8 piglets when inflated, and ballooning was observed in all 3 of the control group. CONCLUSION: The results suggested that application of CSS to the site of circular myotomy for esophageal atresia with a long gap might not induce muscle regeneration but could prevent postoperative ballooning by inducing connective tissue growth.

Anastomosis, Surgical↗