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Dive into the research topics where Keizo Katsumata is active.

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Featured researches published by Keizo Katsumata.


Journal of Pediatric Surgery | 1983

Extended dissection of the portahepatis and creation of an intussuscepted ileocolic conduit for biliary atresia.

Masao Endo; Keizo Katsumata; Jotaro Yokoyama; Yasuhide Morikawa; Hiromichi Ikawa; Shoichiro Kamagata; Miwako Nakano; Yuji Nirasawa; Shigeru Ueno

This paper introduces a new operation for biliary atresia that establishes successful biliary drainage by extending the portahepatic dissection, and decreases ascending cholangitis by incorporating a nonrefluxing intussuscepted draining conduit. An analysis of the postoperative results is presented. The usual dissection of the portahepatis is extended to include the area between and beneath the branches of the right portal vein to incorporate all potentially usable remnants of the intrahepatic ducts. Ascending cholangitis is decreased by interposing an intussuscepted ileocolic segment between the portahepatis and the abdominal wall. This extended dissection of the portahepatis was performed since 1978 in 15 infants with noncorrectable biliary atresia, and bile drainage was achieved in all. In ten infants an intussuscepted ileocolic conduit was constructed. Ascending cholangitis in these ten infants has been either completely absent or easily controlled by antibiotics. The draining bile was highly concentrated due to the water-absorbing capacity of the interposed colonic segment; therefore, fluid and electrolyte disturbances, which develop frequently in patients having jejunal conduits, have never been encountered.


Journal of Pediatric Surgery | 1985

The use of computerized tomography to evaluate anorectal anomalies

Hiromichi Ikawa; Jotaro Yokoyama; Toru Sanbonmatsu; Kazuhiko Hagane; Masao Endo; Keizo Katsumata; Eiichi Kohda

Computerized tomography (CT) was applied to various types of anorectal anomalies to directly image the anal sphincters. In normal cases and low type anomalies, CT demonstrated clear images of the puborectal muscle and external sphincters. Among high type anomalies, the distribution of sphincter muscle in patients with rectovesical fistula is totally different from that seen in patients with rectourethral fistula. In the latter, the puborectal muscle is attached not only around urethra, but also around the distal part of the blind rectum; external sphincters are present as a mass beneath the perineum. In the rectovesical fistula, however, the puborectal muscle cannot be identified and the external sphincters exist only as a string-like structure. CT done postoperatively identified two different causes for incontinence. In one type, the pull-through colon missed the sphincteric musculature, and in the other, sphincters were markedly hypoplastic. CT, therefore, provides adequate imaging to determine the type of operation needed to correct the abnormality.


Journal of Pediatric Surgery | 1980

A quantitative study of acetylcholine in Hirschsprung's disease.

Hiromichi Ikawa; Jotaro Yokoyama; Yasuhide Morikawa; Akira Hayashi; Keizo Katsumata

This is the first report on acetylcholine (Ach) quanititaion of the aganglionic colon by a chemical assay. Ach content in the colon of Hirschsprungs disease was measured by pyrolysis gas chromatography, which was found to be a simple, accurate, and reliable method. Microwave irradiation on the surgical resected specimens was performed before extraction procedure to abolish acetylcholinesterase (Ach-E) and cholineacetyltransferase (CAT) activity in the tissue. Ach content in the ganglionic colon was 8.51 +/- 3.15 nmole/g (n 5 in contrast to 23.79 +/- 14.17 nmole/g (n = 19) in the aganglionic segment of Hirschsprungs disease. The meaning of elevated Ach level in the aganglionic segment was discussed from the pathophysiologic standpoint.


Journal of Pediatric Surgery | 1986

Hirschsprung's disease: Catecholamine content, alpha-adrenoceptors, and the effect of electrical stimulation in aganglionic colon

Yuji Nirasawa; Jotaro Yokoyama; Hiromichi Ikawa; Yasuhide Morikawa; Keizo Katsumata

In order to assess abnormalities in the adrenergic mechanism in the intestine of Hirschsprungs disease, catecholamine concentrations, alpha-adrenoceptors, and the effect of electrical field stimulation were examined in aganglionic segments of colon or rectum. The aganglionic segment had a higher concentration of norepinephrine, assayed with high performance liquid chromatography with an electrochemical detector, whereas concentrations of epinephrine or dopamine were similar in normal and pathological segments. In four patients with extensive aganglionosis, the norepinephrine concentration in aganglionic colon segments decreased progressively in descending, transverse, and ascending colon. The tissue content of alpha-adrenoceptors and their affinity assayed from the specific binding of [3H]dihydro-alpha-ergocryptine appeared similar in normal and aganglionic segments of the rectosigmoidal colon. Electrical field stimulation of normal rectosigmoidal colon segments caused relaxation at low frequencies and contraction at a very high frequency. Relaxation was not abolished by blocking concentrations of propranolol or phentolamine. In aganglionic segments, the predominant response to electrical field stimulation was contraction, which was inhibited by either atropine or tetrodotoxin. These results indicate that an alpha-adrenergic system and cholinergic innervation apparently exist in aganglionic colon segments and that dysfunction of the colon appears to result from lack of a nonadrenergic inhibitory system.


Progress in pediatric surgery | 1989

Motility of the Anorectum After the Soave-Denda Operation

Y. Morikawa; H. Matsufugi; S. Hirobe; Jotaro Yokoyama; Keizo Katsumata

A total of 82 patients were assessed by rectal manometry after operation for Hirschsprungs disease according to the Soave-Denda technique. A positive rectoanal reflex was obtained in 32 cases (39%), whereas the remaining 50 cases (61%) did not exhibit a rectoanal reflex. Among the children examined, 72% showed normal rhythmic activity of the anorectum. Anorectal function tended to increase over the years, 90% having good continence 10 years or more after operation. Patients who encountered postoperative complications had poor continence since such complications may have damaged the levator and sphincter muscles.


Journal of Pediatric Surgery | 1977

Plexiform neurofibromatosis of the ileum in an infant

Masahiko Takahashi; Keizo Katsumata; Jotaro Yokoyama; Seishichi Yokoyama; Atsuo Mikata

An infant is reported in whom severe malabsorptive symptoms developed shortly after birth associated with intermittent episodes of intestinal obstruction. Plexiform neurofibromatosis involving the terminal ileum was found at laparotomy at the age of 6 mo. The infant died from gastrointestinal functional impairment at the age of 1 yr.


Progress in pediatric surgery | 1989

The Electromyographic Examination to Evaluate the External Sphincter Muscle in Anorectal Malformations

A. Hayashi; Jotaro Yokoyama; Keizo Katsumata

Preoperative electromyographic examination is very useful in locating the external sphincter muscles and determining their degree of development. Electromyographic examinations showed the relatively abundant distribution of the external sphincter muscles in the perineum even in high-type anomalies. The results obtained by these examinations lead to the conclusion that preserving both the puborectal and external sphincter muscles should be the main consideration in surgery for anorectal malformations.


Journal of Pediatric Surgery | 1981

Reappraisal of endorectal pull-through procedure II. Animal experiment

Yasuo Ito; Jotaro Yokoyama; Sadao Namba; Yasuhide Morikawa; Keizo Katsumata

Anorectal manometry and pelvic histology following endorectal pull-through and simple abdominoperineal pull-through procedures were studied experimentally in dogs. dogs that had undergone endorectal pull-through preserved normal resting pressure of the anal canal, rectoanal reflex response, and intact perirectal anatomy. Dogs that had simple abdominoperineal pull-through, on the other hand, showed low anal canal pressure, loss of rectoanal reflex, and damage of the pelvic muscles. good continence following endorectal pull-through operation was supported by these physiologic and anatomic studies.


Progress in pediatric surgery | 1989

Problems in Diagnosis of Hirschsprung’s Disease by Anorectal Manometry

Jotaro Yokoyama; T. Kuroda; H. Matsufugi; S. Hirobe; S. Hara; Keizo Katsumata

The purpose of this study is to analyze the results of anorectal manometry and to evaluate the merits and disadvantages of this technique for the diagnosis of Hirschsprungs disease. Studies were performed in 268 patients with constipation, including 95 cases of Hirschsprungs disease. It is concluded from the results that Hirschsprungs disease can be confidently diagnosed by manometric studies. If the studies are performed carefully with a suitable probe, reliability is over 95%. Manometry is the most useful method to differentiate Hirschsprungs disease from other conditions, such as extremely short segment aganglionosis, colonic stenosis, and idiopathic megacolon.


Journal of Pediatric Surgery | 1981

Reappraisal of endorectal pull-through procedure I. Anorectal malformations

Yasuo Ito; Jotaro Yokoyama; Akira Hayashi; Noriyuki Ihara; Keizo Katsumata

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