Toshimi Sakai

Thoracoscopic transdiaphragmatic microwave coagulation therapy for a liver tumor

AbstractBackground: Microwave coagulation therapy (MCT) for hepatocellular carcinoma, which induces tumor coagulonecrosis, is now recognized as an efficient treatment. However, when a tumor is located just below the top of the diaphragmatic dome, laparotomical MCT requires a large incision, and percutaneous MCT is sometimes impossible. Patients and Methods: The patients were four men and two women. There were four cases of hepatocellular carcinoma and two cases of liver metastasis from colorectal cancer. All tumors were located below the top of the diaphragmatic dome. Thoracoscopic transdiaphragmatic MCT (TTMCT) was performed under general anesthesia using an endotracheal double-lumen tube. Identification of the tumor site in the liver was performed using an ultrasonic probe under thoracoscopic observation. After the diaphragm above the tumor was opened, a needle electrode to transmit microwaves was inserted directly into the tumor. Microwave irradiation was repeated to coagulate the entire lesion. After completion of TTMCT, the diaphragm was closed thoracoscopically. Results: TTMCT was successfully administered to cancerous lesions in all six patients. The postoperative course was uneventful, and the average postoperative hospitalization period was 10.5 days. None of the patients has shown any recurrence during a follow-up period of 4–23 months. Conclusions: TTMCT was performed without any difficulty using the thoracoscopic surgical technique, and its therapeutic outcome was satisfactory. This is effective for tumors located just below the top of the diaphragmatic dome.

Transgastrostomal endoscopic surgery for early gastric carcinoma and submucosal tumor

AbstractBackground: Laparoscopic intraluminal surgery of the stomach is now widely used for a lesion on the posterior wall. However, this procedure has some technical limitation related to the intricate introduction of the surgical instruments into the gastric lumen. In this article, we report our newly developed technique of transgastrostomal endoscopic surgery that overcomes this limitation and is also suitable for full-thickness gastric wall resection of a lesion in the wall. Methods: After making a 4-cm-long temporary gastrostomy, a Buess-type endoscope is inserted into the gastric lumen through the gastrostomy. The operation is performed inside the gastric lumen under video camera guidance using electrocautery, scissors, and forceps. After resection, the wound in the mucosa or the wound after full-thickness resection is endoluminally sutured. Mucosal resection was performed in six cases of early gastric carcinoma, two cases of atypical epithelium, and one case of ectopic pancreas. Full-thickness wall resection was performed in four cases of a leiomyoma. Results: In all 13 cases, the lesion could be precisely located by the video camera. All lesions were then resected endoluminally. The mean duration of the operation was 148 min. The postoperative course in all cases was uneventful. Conclusions: Transgastrostomal endoscopic surgery is minimally invasive and an efficient tissue-preserving technique for the removal of early gastric carcinoma or submucosal tumor.

Clinical use of a front lifting hood rectoscope tube for transanal endoscopic microsurgery

AbstractBackground: Transanal endoscopic microsurgery (TEM), a procedure developed by Buess et al. requires a specially designed surgical rectoscope system, and adequate training for its operation is mandatory. In order to simplify the performance of TEM, and to allow the use of additional surgical instruments and devices, we have developed a new rectoscope tube. Methods: The forward half of the tube can be opened longitudinally by hand. Our working insert platform is hollowed and includes a channel for an endoscope. The resection procedure can be performed under normal atmospheric pressure. This newly developed rectoscope system has already been employed clinically. TEM was performed using our original forward lifting hood rectoscope tube in 20 patients, including 12 cases of sessile adenoma and eight cases of early carcinoma. Results: The forward hood of the tube was opened to the maximum angle of 25° in eight patients and 15–20° in the other 12 patients. The visible field of the rectal interior was extended in direct proportion to the angle. Through our working insert platform, instruments and devices could be used for either laparoscopic or open surgery. Conclusions: These modifications have made TEM easier and will therefore make the procedure available to more surgeons.

Dye-enhanced selective laser ablation for surgical mucosectomy.

The diode laser operates at a wavelength of 805 nm; indocyanine green (ICG) has a maximum energy absorption of a wavelength of approximately 800 nm. The effect of the diode laser as a laser knife can be significantly enhanced with an injection of ICG. In the present study, this dye-enhanced photothermal effect was investigated in the field of surgical endoscopy. A 9-cm2 region of the canine gastric mucosa was removed by the laser after injection of 5 ml of ICG solution at a concentration of 0.5 mg/mL into the submucosal space. The diode laser was used at a power output of 10 watts. The canine stomach was removed 10 days after the operation to investigate the site histologically. Clinical application using transanal endoscopic microsurgery (TEM) was employed using a dye-enhanced laser in five patients with a rectal adenoma. The pathological changes in the canine gastric wall resected 10 days after the operation showed that the low-power laser enhanced by ICG produced less fibrosis in the submucosal space than electrocautery. Mucosal resection using a dye-enhanced laser was easily performed in these five patients. It was concluded that this easy removal of the mucosa by a dye-enhanced laser was due to its ability to produce hemostasis of the vessels and its excellent tissue-cutting effect.

Radical lymphadenectomy for rectal cancer facilitated by a carbon particle infusion lymphangiography

For the intraoperative visualization of the para-aortic nodes and those around the iliac vessels, a fine carbon particle solution was infused into the bilateral pedal lymphatic vessels of 12 patients with rectal carcinoma. A low anterior resection with radical lymph node dissection was then performed while preserving pelvic autonomic nerves. Of 444 lymph nodes removed from the iliac arterial region, 430 were stained with carbon black (96.8%), even though the black staining was not perfect in the nodes of the inferior mesenteric arterial region. All of the lateral black stained nodes were clearly visible and hence could be easily excised. The average number of dissected nodes in one patient was 43.8 in this dissection with carbon particle infusion, which was larger than those of conventional lymph node dissection. We then examined the length of time that a postoperative indwelling bladder catheter was needed as an indication for autonomic nerve damage, and it was ascertained that less damage occurred in this operation compared to other types of dissections, such as conventional or extended lymph node dissection.

Highly sensitive immunohistological study for detection of estrogen receptor in human breast cancer.

Immunohistological methods for the detection of estrogen receptor in human breast cancer using formalin‐fixed, paraffin‐embedded tissue not only have the advantages of being cheaper and requiring less tissue but also have several theoretical advantages. For example, such methods enable direct histological visualization of the assessed tissue and thereby reduce sampling error. Traditional immunohistological methods (traditional LSAB), however, show false‐negative reactions more often than the enzyme‐binding immunoassay method (EIA).