Takamichi Kamiyama

Surgical treatment of congenital dilatation of the bile duct with special reference to late complications after total excisional operation

The surgical treatment of 100 cases with congenital dilatation of bile duct with special reference to late complications was analyzed. There were no deaths nor occurrences of malignancy. Among 91 patients who had undergone the standard operation, namely total excision of the dilated extrahepatic bile duct and reconstruction after Roux-en-Y hepaticojejunostomy, there were one early complication (pancreatic juice leakage) and five late complications (four intrahepatic gallstones and one liver abscess). The cause of intrahepatic gallstone formation after a total excisional operation was attributed to the remaining intrahepatic bile duct dilatation and the stenosis located between the intrahepatic bile duct dilatation and the common hepatic duct. Accordingly, these results support the total excisional procedure for this condition; however, with regard to the cases associated with cystic dilatation of intrahepatic bile ducts, completely free bile drainage from the dilated intrahepatic biliary system should be performed at the radical operation.

Development of an implantable artificial anal sphincter by the use of the shape memory alloy.

In this study, we developed and assessed an artificial anal sphincter driven by an shape memory alloy actuator (AS-SMA). The performance characteristics of the device were analyzed with a measurement system. Assessment showed that the AS-SMA could generate a pressure of 55 mm Hg at an atmospheric temperature of 36°C, and displacement of the SMA actuator was 7.5 mm when the temperature of the SMA plate was 55°C. To evaluate opening and closing, we studied a piglet colostomy model, in which the AS-SMA was implanted around the colostomy in the extraperitoneal space. Flow control tests using living porcine intestine revealed that the AS-SMA could maintain fecal continence against an intestinal pressure of 75 mm Hg. The high pressure zone corresponding to the location of the device was demonstrated in a manometric examination. For 6 days after surgery, we activated the AS-SMA twice a day and observed the bowel movements. The animal experiment indicated that the AS-SMA is able to control the bowel movements of patients with fecal incontinence if several problems, such as burning of tissue around the device and compression injury of the intestine, are resolved.

Thermal control of shape memory alloy artificial anal sphincters for complete implantation

This paper presents an approach for the thermal control of an artificial anal sphincter using shape memory alloys. An artificial anal sphincter has been proposed by the authors to resolve problems of severe fecal incontinence in patients. The basic design of the artificial sphincter consists of two all-round shape memory alloy plates as the main functional parts, and heaters that are attached to the SMA plates for generating the thermal cycles required for the phase transformation accompanied shape changes of the plates. The SMA artificial sphincter could be fitted around intestines, performing an occlusion function at body temperature and a release function upon heating. Thermal compatibility of such prostheses is most important and is critical for practical use. Since a temperature rise of approximately 20 °C from body temperature is needed to activate a complete transformation of SMA plates, an earlier model of ours allowed only a short period of heating, resulting in incomplete evacuation. In this work, a thermal control approach using a temperature-responsive reed switch has been incorporated into the device to prevent the SMA plates from overheating. Then, with thermal insulation the artificial anal sphincter is expected to allow a long enough opening period for fecal continence; without any thermal impact to the surrounding tissues that would be in contact with the artificial sphincter. Thermal control was confirmed in both in vitro and in vivo experiments, suggesting the effectiveness of the present approach. The modified SMA artificial anal sphincter has been implanted into animal models for chronic experiments of up to 4 weeks, and has exhibited good performance by maintaining occlusion and release functions. At autopsy, no anomaly due to thermal impact was found on the surfaces of intestines that had been in contact with the artificial anal sphincter.

Functional evaluation of an artificial anal sphincter using shape memory alloys.

This article describes an implantable artificial anal sphincter using shape memory alloys and its in vivo assessment in porcine models. The new design was developed as a low invasive prosthesis with a simple structure to solve the problem of severe fecal incontinence in patients with hypoplastic sphincters or without anal sphincters and especially for ostomates. The artificial anal sphincter consists of two shape memory alloy (SMA) plates as the main functional parts to perform two basic functions when the SMA artificial sphincter is fitted around intestines (i.e., an occlusion at body temperature and an opening function on heating). Our previous assessments with short-term animal experiments revealed promising properties with the occlusion function of the device, although some complications, such as overpressure induced ischemia, heat burn, and infections, remained. This article addresses the concerns related to the practical use of the device, the power supplement to drive the actuator, and overheating protection of the device inside bodies. Results of chronic animal experiments of up to 4 weeks suggested great potential for the improved device.

Two-point rectal mucosal biopsy for selection of surgical treatment of Hirschsprung's disease

A two-point rectal mucosal biopsy (utilizing a histochemical study), namely biopsies at sites 5 to 10 mm and 30 to 50 mm oral to the dentate line, was developed to differentiate patients who can be treated adequately by rectal myectomy without colostomy and those who require other definitive surgery for Hirschsprungs disease. The examinations were performed in 28 patients suspected having a short aganglionic rectum. Ganglion cells were demonstrated by upper biopsy in four of 13 neonates, six of nine infants, and three of six children. These cases were successfully treated by rectal myectomy. The two-point rectal mucosal biopsy is useful not only for making definitive diagnosis but also for the selection of the surgical treatment for patients with Hirschsprungs disease.

Coping Patterns in a Mother of a Child with Multiple Congenital Anomalies: A Case Study

Objective: To study the coping pattern of a mother of a child with multiple congenital anomalies (MCAs) based on interview data. Methods: The mother of a child born at Tohoku University Hospital, Japan, who was diagnosed with MCAs at 3 days of age and subsequently underwent surgery at 7 months, was asked to be interviewed. She answered semi structured interviews at the hospital when the child was two years old and again when the child was five years old. Psychological assessment with the State-Trait Anxiety Inventory (STAI) and the Self-rating Depression Scale (SDS) was conducted before each interview. Results: Psychological assessment showed that the mother had high levels of anxiety and depression when the child was two and when the child was five years old. The interview data showed that when the mother first learned that her baby had MCAs, her initial reaction was (1) shock. She then felt (2) Absent-minded. (3) Responsibility to take care of her child. (4) Depression, (5) Defense against acceptance of child’s disease as it is. The mother had this sequence of thoughts and emotions between the times of diagnosis of MCAs up through the time of surgery. In the first stage of coping, the mother showed defense against learning as much as possible about her child’s disease and MCAs. In the second stage of coping, the mother reported (when the child was five years old) that she felt that she had some control over her child’s situation. The mother started to accept her child’s disease as she as possible and learned what would be happened to her child. Conclusion: The mother of the child with MCAs was in a severe psychological condition over at least five years since diagnosis. In order to alleviate the psychological stress on mothers of a child with MCAs or other congenital disease, it is useful to educate the mother so that she can understand her child’s disease. However, it is difficult for parents without medical knowledge to understand a complicated disease such as MCAs. Providers need more training to educate parents with MCAs.