Ultrasonic Cleaning for Irrigating Purulent Substances during Laparoscopic Gastrointestinal Surgery.

To improve the outcome of laparoscopic gastrointestinal surgery, improvement in the technology for removing purulent substances from the abdominal cavity is required. Ultrasonic cleaning technology may be suitable for the task. However, it is necessary to examine cleaning efficiency and safety through model tests that can lead to clinical trials for practical use. Nine surgical specialists first estimated the distribution of the actual attachment of purulent substances using videos of removing pus-like model dirt as an evaluation scale. Subsequently, cleaning tests were conducted using a small-size shower with model dirt that was somewhat difficult to remove, and its suitability as a model sample was confirmed. A mixture of miso and other substances was attached to a silicon sheet to prepare a test sample. The model dirt could be removed within a few seconds by cleaning using a probe-type ultrasonic homogenizer while the test sample was submerged in water. This performance greatly surpassed that of water flow cleaning under increased water pressure. An ultrasonic cleaner that is useful for irrigation during laparoscopic surgery will be suitable for practical use in laparoscopic surgery.

A Small-scale Washing Test That Reproduces the Mechanical Forces Occurring Inside a Commercial Washing Machine.

A small-scale washing test model was proposed to reproduce the mechanical forces occurring inside a household washing machine in Japan. Washing tests were conducted using household washing machines, a tergotometer, and four types of small-scale washing test models using JIS-designated artificially soiled fabric. As a result of conducting washing tests in 10 households during winter and summer, we determined that the mechanical force of the washing machine was equivalent to 90-100 rpm agitation by a tergotometer. Similar detergency was obtained by rotating a 50 mL centrifuge tube with a tube rotator. Then, a centrifuge tube containing 35 mL of detergent solution, ten 1/4-inch stainless steel balls, and three 20 × 20 mm soiled fabrics was rotated at 50 rpm. Probability density functional theory analysis did not identify any kinetic problems, which means that the properties of the applied mechanical forces are similar to those occurring in the tergotometer and tube rotator test.

[A Case of Laparoscopic Repair for Hiatal Hernia Occurred Five Years after Esophagectomy for Esophageal Cancer].

A 70s man underwent minimally invasive esophagectomy and gastric conduit reconstruction via the posterior mediastinal route for early esophageal cancer 5 years ago. Three days prior to hospital visit, he presented with abdominal fullness, left chest pain, and vomiting. A CT revealed a postoperative hiatal hernia, and emergency surgery was performed laparoscopically. The laparoscopic findings showed that the transverse colon had prolapsed into the left thoracic cavity through the esophageal hiatus on the left side of the gastric conduit. The transverse colon had no sign of necrosis. The diaphragmatic defect was closed with unabsorbable suture. Increased bowel motility due to postoperative fat loss in the mesentery and intra-abdominal pressure are thought to be causes of the hernia. In addition, decreased adhesion formation due to endoscopic surgery may be a contributing factor. Although there is no unanimous opinion regarding the suture fixation of the conduit to the diaphragm after esophagectomy, it should be performed to prevent a herniation. Postoperative hiatal hernia occurs more than 5 years after the surgery is relatively rare, but its occurrence should be noted.

Synergistic Action of Temperature and pH Factors in the Cleaning of Fatty Acids Soils; Analyzed by Probability Density Functional Method.

In this study, the interaction between the temperature and the pH of soil containing fatty acids with sodium dodecyl sulfate (SDS) aqueous solution was investigated to elucidate their synergistic effect in cleaning. A tergotometer was used for the cleaning test, and the cleaning results were analyzed by the probability density functional method, using the calculated parameter, µ rl , as an index of the cleaning power. The increase in µ rl by one of the factors was defined as ΔX or ΔY and the increase in µ rl by the both factors was defined as Δ(X + Y). It is assumed that there is a synergistic effect when Δ(X + Y) > ΔX + ΔY. The cleaning of fatty acid stains followed the addition rule pertaining to mechanical force and the pH effect. However, synergy was observed between the temperature and the pH effect. This was also supported by the plot of µ rl vs 1/T and observations using a phase-contrast microscope.

[A Case of Internal Hernia into a Reconstructed Pelvic Floor and Torsion of Jejunum near the Treitz Ligament after Laparoscopic Abdominoperineal Resection].

A 50s women underwent laparoscopic abdominoperineal resection(APR)for rectal cancer. Laparotomy was performed on the 8th postoperative day because of intestinal obstruction. An internal hernia was observed at the pelvic floor and the hernia orifice was found at the retroperitoneum that was sutured in the initial operation. On the other hand, the jejunum near the Treitz ligament was twisted, resulting in ischemic necrosis. The reason of the internal hernia is considered that a suction drain placed during the initial operation may have caused the rupture of the fragile part of the sutured peritoneum. Furthermore, increase of intra-abdominal pressure due to the internal hernia may have exacerbated the torsion of the jejunum near the Treitz ligament. This is probably due to the failure to the adequate reposition of the small intestine at the end of the initial operation. There is no consensus of the need for retroperitoneal sutures for APR. Currently, we only spray anti-adhesion agents on the pelvic floor without retroperitoneal reconstruction. Although the mobilization of small intestine is important to provide a good operative view in laparoscopic colorectal surgery, it is also important to confirm the reposition of the small intestine at the end of surgery.