Preliminary comparative study of lower extremity pressure measurements under the conditions using former models and new lithotomy stirrups in rectal cancer surgery.

BACKGROUND: This study aimed to investigate the effect of the use of new lithotomy stirrups-2 on the pressure dispersal on lower limbs, which may lead to the prevention of well-leg compartment syndrome (WLCS) and deep venous thrombosis (DVT), which are the most commonly associated adverse events with laparoscopic and robot-assisted rectal surgery. METHODS: A total of 30 healthy participants were included in this study. The pressure (mmHg) applied on various lower limb muscles when using conventional lithotomy stirrups-1 and new type stirrups-2 was recorded in various lithotomy positions; 1) neutral position, 2) Trendelenburg position (15°) with a 0° right inferior tilt, and 3) Trendelenburg position (15°) with a 10° right inferior tilt. Using a special sensor pad named Palm Q®, and the average values were compared between two types of stirrups. RESULTS: The use of new lithotomy stirrups-2 significantly reduced the pressure applied on the lower limb muscles in various lithotomy positions compared with the use of lithotomy stirrups-1. The most pressured lower limb muscle when using both lithotomy stirrups was the central soleus muscle, which is the most common site for the development of WLCS and DVT. In addition, when using the conventional lithotomy stirrups-1, the pressure was predominantly applied to the proximal soleus muscle; however, when using lithotomy stirrups-2, the pressure was shifted to the more distal soleus muscle. CONCLUSION: These results suggest that the new lithotomy stirrups-2 is useful in reducing the pressure load on leg muscles, especially on the proximal to central soleus, and may reduce the incidence of WLCS and DVT after rectal surgery performed in the lithotomy position. Further clinical studies are needed to determine whether the use of lithotomy stirrups-2 prevents these complications in various clinical settings.

Bacterial accumulation in intestinal folds induced by physical and biological factors.

BACKGROUND: The gut microbiota, vital for host health, influences metabolism, immune function, and development. Understanding the dynamic processes of bacterial accumulation within the gut is crucial, as it is closely related to immune responses, antibiotic resistance, and colorectal cancer. We investigated Escherichia coli behavior and distribution in zebrafish larval intestines, focusing on the gut microenvironment. RESULTS: We discovered that E. coli spread was considerably suppressed within the intestinal folds, leading to a strong physical accumulation in the folds. Moreover, a higher concentration of E. coli on the dorsal side than on the ventral side was observed. Our in vitro microfluidic experiments and theoretical analysis revealed that the overall distribution of E. coli in the intestines was established by a combination of physical factor and bacterial taxis. CONCLUSIONS: Our findings provide valuable insight into how the intestinal microenvironment affects bacterial motility and accumulation, enhancing our understanding of the behavioral and ecological dynamics of the intestinal microbiota.

Glucose stockpile in the intestinal apical brush border in C. elegans.

Revealing the mechanisms of glucose transport is crucial for studying pathological diseases caused by glucose toxicities. Numerous studies have revealed molecular functions involved in glucose transport in the nematode Caenorhabditis elegans, a commonly used model organism. However, the behavior of glucose in the intestinal lumen-to-cell remains elusive. To address that, we evaluated the diffusion coefficient of glucose in the intestinal apical brush border of C. elegans by using fluorescent glucose and fluorescence recovery after photobleaching. Fluorescent glucose taken in the intestine of worms accumulates in the apical brush border, and its diffusion coefficient of ∼10-8 cm2/s is two orders of magnitude slower than that in bulk. This result indicates that the intestinal brush border is a viscous layer. ERM-1 point mutations at the phosphorylation site, which shorten the microvilli length, did not significantly affect the diffusion coefficient of fluorescent glucose in the brush border. Our findings imply that glucose enrichment is dominantly maintained by the viscous layer composed of the glycocalyx and molecular complexes on the apical surface.

Totally laparoscopic surgery for a hydrocele of the canal of Nuck extending from the abdominal cavity to the subcutaneous space: a case report.

BACKGROUND: Hydrocele of the canal of Nuck (HCN) is a rare disease, and its indications for laparoscopic surgery are not well-established. CASE PRESENTATION: A 53-year-old woman was referred to our hospital due to an uncomfortable thumb-sized inguinal mass. Preoperative computed tomography scan and magnetic resonance imaging revealed a hydrocele extending from the abdominal cavity around the left deep inguinal ring via the inguinal canal to the subcutaneous space. The patient was diagnosed with HCN protruding into the abdominal cavity and extending to the subcutaneous space. Laparoscopy can easily access the hydrocele protruding into the abdominal cavity. Furthermore, laparoscopic hernioplasty can be superior to the anterior approach for females. Hence, laparoscopic surgery was performed. After transecting the round ligament of the uterus, a tense 3-cm hydrocele was dissected with it. In order to approach the hydrocele distal to the deep inguinal ring, the transversalis fascia was incised medially to the inferior epigastric vessels. The subcutaneously connected hydrocele was excised from the incision. Then, the enlarged deep inguinal ring was reinforced using a mesh with the laparoscopic transabdominal preperitoneal approach. The patient was discharged 2 days postoperatively. Laparoscopic resection can be more effective for a hydrocele protruding into the abdominal cavity as it facilitates an easy access to the hydrocele. Moreover, laparoscopic resection of a hydrocele extending from the inguinal canal to the subcutaneous space via a transversalis fascia incision can be safer, with low risk of injury to the inferior epigastric vessels. The incised transversalis fascia and the enlarged deep inguinal ring due to the HCN were simultaneously repaired with the laparoscopic transabdominal preperitoneal repair. There are two reports on laparoscopic resection via a transversalis fascia incision for HCNs located between the inguinal canal and the subcutaneous space, which does not require intraperitoneal hydrocelectomy. However, this is the first report on laparoscopic resection of large HCNs protruding into the abdominal cavity and extending beyond the inguinal canal into the subcutaneous space via intraperitoneal hydrocelectomy and a transversalis fascia incision. CONCLUSIONS: Laparoscopic surgery with transversalis fascia incision can be useful for HCNs extending from the abdominal cavity to the subcutaneous space.

Visualization of droplets and aerosols in simulated dental treatments to clarify the effectiveness of oral suction devices.

PURPOSE: The hazards of aerosols generated during dental treatments are poorly understood. This study aimed to establish visualization methods, discover conditions for droplets/aerosols generated in simulating dental treatments and identify the conditions for effective suction methods. METHODS: The spreading area was evaluated via image analysis of the droplets/aerosols generated by a dental air turbine on a mannequin using a light emitting diode (LED) light source and high-speed camera. The effects of different bur types and treatment sites, reduction effect of intra-oral suction (IOS) and extra-oral suction (EOS) devices, and effect of EOS installation conditions were evaluated. RESULTS: Regarding the bur types, a bud-shaped bur on the air turbine generated the most droplets/aerosols compared with round-shaped, round end-tapered, or needle-tapered burs. Regarding the treatment site, the area of droplets/aerosols produced by an air turbine from the palatal plane of the anterior maxillary teeth was significantly higher. The generated droplet/aerosol area was reduced by 92.1% by using IOS alone and 97.8% by combining IOS and EOS. EOS most effectively aspirated droplets/aerosols when placed close (10 cm) to the mouth in the vertical direction (0°). CONCLUSIONS: The droplets/aerosols generated by an air turbine could be visualized using an LED light and a high-speed camera in simulating dental treatments. The bur shape and position of the dental air turbine considerably influenced droplet/aerosol diffusion. The combined use of IOS and EOS at a proper position (close and perpendicular to the mouth) facilitated effective diffusion prevention to protect the dental-care environment.

Electrolyzed hypochlorous acid water exhibits potent disinfectant activity against various viruses through irreversible protein aggregation.

It is essential to employ efficient measures to prevent the transmission of pathogenic agents during a pandemic. One such method involves using hypochlorous acid (HClO) solution. The oxidative properties of HClO water (HAW) can contribute to its ability to eliminate viral particles. Here, we examined a highly purified slightly acidic hypochlorous acid water (Hp-SA-HAW) obtained from the reverse osmosis membrane treatment of an electrolytically-generated SA-HAW for its anti-viral activity and mode of action on viral proteins. Hp-SA-HAW exhibited broad-spectrum antiviral effects against various viruses, including adenovirus, hepatitis B virus, Japanese encephalitis virus (JEV), and rotavirus. Additionally, Hp-SA-HAW treatment dose-dependently resulted in irreversibly aggregated multimers of the JEV envelope and capsid proteins. However, Hp-SA-HAW treatment had no discernible effect on viral RNA, indicating that Hp-SA-HAW acts against amino acids rather than nucleic acids. Furthermore, Hp-SA-HAW substantially reduced the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the ancestral variant and other multiple variants. Hp-SA-HAW treatment induced the aggregation of the SARS-CoV-2 spike and nuclear proteins and disrupted the binding of the purified spike protein of SARS-CoV-2 to human ACE2. This study demonstrates that the broad-spectrum virucidal activity of highly purified HClO is attributed to viral protein aggregation of virion via protein oxidation.

Endotracheal tube, by the venturi effect, reduces the efficacy of increasing inlet pressure in improving pendelluft.

In mechanically ventilated severe acute respiratory distress syndrome patients, spontaneous inspiratory effort generates more negative pressure in the dorsal lung than in the ventral lung. The airflow caused by this pressure difference is called pendelluft, which is a possible mechanisms of patient self-inflicted lung injury. This study aimed to use computer simulation to understand how the endotracheal tube and insufficient ventilatory support contribute to pendelluft. We established two models. In the invasive model, an endotracheal tube was connected to the tracheobronchial tree with 34 outlets grouped into six locations: the right and left upper, lower, and middle lobes. In the non-invasive model, the upper airway, including the glottis, was connected to the tracheobronchial tree. To recreate the inspiratory effort of acute respiratory distress syndrome patients, the lower lobe pressure was set at -13 cmH2O, while the upper and middle lobe pressure was set at -6.4 cmH2O. The inlet pressure was set from 10 to 30 cmH2O to recreate ventilatory support. Using the finite volume method, the total flow rates through each model and toward each lobe were calculated. The invasive model had half the total flow rate of the non-invasive model (1.92 L/s versus 3.73 L/s under 10 cmH2O, respectively). More pendelluft (gas flow into the model from the outlets) was observed in the invasive model than in the non-invasive model. The inlet pressure increase from 10 to 30 cmH2O decreased pendelluft by 11% and 29% in the invasive and non-invasive models, respectively. In the invasive model, a faster jet flowed from the tip of the endotracheal tube toward the lower lobes, consequently entraining gas from the upper and middle lobes. Increasing ventilatory support intensifies the jet from the endotracheal tube, causing a venturi effect at the bifurcation in the tracheobronchial tree. Clinically acceptable ventilatory support cannot completely prevent pendelluft.

A case of non-ampullary duodenal adenosquamous carcinoma with successful emergency pancreaticoduodenectomy for gastrointestinal hemorrhage.

BACKGROUND: Although most duodenal carcinomas are pathological adenocarcinomas, a small number of cases have been reported of adenosquamous carcinoma, characterized by variable combinations of two malignant components: adenocarcinoma and squamous cell carcinoma. However, owing to the small number of cases of non-ampullary duodenal adenosquamous carcinoma, there have been no reported cases of emergency pancreaticoduodenectomy for gastrointestinal hemorrhage due to non-ampullary duodenal adenosquamous carcinoma. CASE PRESENTATION: A 66-year-old Japanese male presented to the referring hospital with a chief complaint of abdominal pain, diarrhea, and dark urine that had persisted for 1 month. The patient was referred to our hospital because of liver dysfunction on a blood examination. Laboratory results of the blood on the day of admission showed that total and direct bilirubin levels (12.0 mg/dl and 9.6 mg/dl) were markedly increased. An endoscopic retrograde biliary drainage tube was inserted for the treatment of obstructive jaundice, and imaging studies were continuously performed. Contrast-enhanced computed tomography and endoscopy revealed an ill-defined lesion involving the second portion of the duodenum, predominantly along the medial wall, and measuring 60 mm in diameter. No metastases were observed by positron emission tomography. Pancreaticoduodenectomy was planned based on the pathological findings of poorly differentiated adenocarcinoma. However, 2 days before the scheduled surgery, the patient experienced hemorrhagic shock with melena. Owing to poor hemostasis after endoscopic treatment and poor control of hemodynamic circulation despite blood transfusion, radiological embolization and hemostasis were attempted but were incomplete. An emergency pancreaticoduodenectomy was performed after embolizing the route from the gastroduodenal artery and pseudoaneurysm area to reduce bleeding. The operation was completed using an anterior approach without Kocherization or tunneling due to the huge tumor. The operation time was 4 h and 32 min, and blood loss was 595 mL The pathological diagnosis was adenosquamous carcinoma. The postoperative course was uneventful with 17 day hospital stay and the patient is currently well, with no signs of recurrence 9 months after surgery. CONCLUSIONS: This report presents an extremely rare case of successful emergency pancreaticoduodenectomy for gastrointestinal hemorrhage caused by non-ampullary duodenal adenosquamous carcinoma.

Bing-Neel syndrome with a paravertebral mass.

Bing-Neel syndrome, a rare neurological complication of Waldenström macroglobulinemia, is caused by the direct infiltration of malignant lymphoplasmacytic cells into the central nervous system. We report a patient who presented with back pain, weakness, lower extremity numbness, and gait disturbance accompanied by immunoglobulin M paraproteinemia and lymphoplasmacytic lymphoma in the bone marrow. Thoracic and lumbar magnetic resonance imaging revealed a long paravertebral mass around the spinal column, but the direct infiltration could not be proven. The patient was diagnosed with possible Bing-Neel syndrome and managed with bendamustine and rituximab. After chemotherapy, the patient's neurological and radiological findings improved. Magnetic resonance imaging should be considered when the Bing-Neel syndrome diagnosis is unclear.

Successful treatment with laparoscopic extended posterior sectionectomy for inflammatory pseudotumor in the liver with para-aortic lymphadenitis.

Inflammatory pseudotumor (IPT) is a rare disease that requires a differential diagnosis from malignancies. We describe a case of hepatic IPT with para-aortic lymphadenopathy, treated with a stepwise strategy of laparoscopic surgery. A 61-year-old woman was referred with a liver lesion. Computed tomography revealed a 13 cm well-defined lesion in segments VII-VI. The patient also had bead-like enlarged lymph nodes from the perihilar to the para-aortic regions. Although percutaneous lymph node biopsy showed no evidence of malignancy, 18 F-fluorodeoxyglucose positron emission tomography revealed accumulation in the lesion and lymph nodes. Lymph nodes were harvested laparoscopically for intraoperative pathological examination. With no evidence of malignancy, laparoscopic liver resection was continuously performed as a diagnostic treatment. The patient was given a pathological diagnosis of IPT and was discharged on the 16th day and is well 2 years after surgery. The minimally invasive laparoscopic approach to diagnostic treatment could be useful with secure advantages.

Effectiveness of substantial shortening of the endotracheal tube for decreasing airway resistance and increasing tidal volume during pressure-controlled ventilation in pediatric patients: a prospective observational study.

The endotracheal tubes (ETTs) used for children have a smaller inner diameter. Accordingly, the resistance across ETT (RETT) is higher. Theoretically, shortening the ETTs can decrease total airway resistance (Rtotal), because Rtotal is sum of RETT and patient's airway resistance. However, the effectiveness of ETT shortening for mechanical ventilation in the clinical setting has not been reported. We assessed the effectiveness of shortening a cuffed ETT for decreasing Rtotal, and increasing tidal volume (TV), and estimated the RETT/Rtotal ratio in children. In anesthetized children in a constant pressure-controlled ventilation setting, Rtotal and TV were measured with a pneumotachometer before and after shortening a cuffed ETT. In a laboratory experiment, the pressure gradient across the original length, shortened length, and the slip joint alone of the ETT were measured. We then determined the RETT/Rtotal ratio using the above results. The clinical study included 22 children. The median ETT percent shortening was 21.7%. Median Rtotal was decreased from 26 to 24 cmH2O/L/s, and median TV was increased by 6% after ETT shortening. The laboratory experiment showed that ETT length and the pressure gradient across ETT are linearly related under a certain flow rate, and approximately 40% of the pressure gradient across the ETT at its original length was generated by the slip joint. Median RETT/Rtotal ratio were calculated as 0.69. The effectiveness of ETT shortening on Rtotal and TV was very limited, because the resistance of the slip joint was very large.

Laparoscopic Repeat Liver Resection-Selecting the Best Approach for Repeat Liver Resection.

Recurrence of liver cancers after liver resection (LR), such as recurrences of hepatocellular carcinoma and colorectal liver metastases, is often treated with repeat LR (RLR) as the only curative treatment. However, RLR is associated with an increased risk of complications. The indications for the currently emerging laparoscopic LR and its advantages and disadvantages for repeat treatment are still under discussion. Our multi-institutional propensity-score matched analyses of laparoscopic vs. open RLRs for hepatocellular carcinoma showed the feasibility of laparoscopic RLR with comparable short- and long-term outcomes. Small blood loss and low morbidity was observed in selected patients treated using laparoscopic RLR in which total adhesiolysis can be dodged, with speculations that laparoscopic minor repeated LR can minimize functional deterioration of the liver. However, there are several disadvantages, such as easily occurring disorientation and difficulty in repeated wide-range dissection of Glissonian pedicles. Recently emerging small anatomical resection, indocyanine green fluorescence-guided surgery, and robot-assisted surgery are promising tools for the further development of laparoscopic RLR. This review discusses how laparoscopic RLR, as a powerful unique local therapy causing less damage to the residual liver and surrounding structures, could contribute to the outcomes of repeated treatments for cancers and its future perspectives.

Circular-stapled esophagogastrostomy using the keyhole procedure after radical esophagectomy for esophageal cancer.

BACKGROUND: Anastomotic leakage of cervical esophagogastrostomy following radical esophagectomy for esophageal cancer has reduced over time; however, postoperative anastomotic stricture still occurs at a considerably high rate. We developed a novel method of circular-stapled esophagogastrostomy by employing the keyhole procedure, which uses a linear stapler to enlarge the anastomotic opening made with a circular stapler (CS). METHODS: We retrospectively reviewed 70 patients with esophageal cancer who underwent transthoracic esophagectomy and reconstruction via cervical CS-mediated anastomosis with or without the keyhole procedure between 2018 and 2020. The primary outcome was postoperative anastomotic stricture incidence within 180 days after surgery. RESULTS: Among 70 patients, 22 underwent the keyhole procedure (CS + K group) and the remaining did not (CS group). No differences were observed in patients' age, sex, body mass index, performance status, American Society of Anesthesiologists physical status, Charlson's comorbidity index, tumor histological type, tumor location, clinical stage, or preoperative treatment. A smaller stapler was used in the CS + K group (p < 0.001). Incidence of anastomotic stricture was significantly different (CS vs. CS + K, 18.8 vs. 0%, p = 0.049), especially when a 21 or 23 mm CS was used (CS vs. CS + K, 50.0 vs. 0%, p = 0.005). Univariate analysis confirmed that CS ≤ 23 without keyhole was a significant risk factor (p = 0.001). CONCLUSIONS: The keyhole procedure could be a simple and useful alternative technique that reduces the risk of stricture formation in cervical esophagogastric anastomosis, especially when using the smaller-sized CS.

Establishment of a new practical telesurgical platform using the hinotori™ Surgical Robot System: a preclinical study.

AIM: The recent development of new surgical robots and network telecommunication technology has opened new avenues for robotic telesurgery. Although a few gastroenterological surgeries have been performed in the telesurgery setting, more technically demanding procedures including gastrectomy with D2 lymphadenectomy and intracorporeal anastomosis have never been reported. We examined the feasibility of telesurgical robotic gastrectomy using the hinotori™ Surgical Robot System in a preclinical setting. METHODS: First, the suturing time in the dry model was measured in the virtual telesurgery setting to determine the latency time threshold. Second, a surgeon cockpit and a patient unit were installed at Okazaki Medical Center and Fujita Health University, respectively (approximately 30 km apart), and connected using a 10-Gbps leased optic-fiber network. After evaluating the feasibility in the dry gastrectomy model, robotic distal gastrectomies with D2 lymphadenectomy and intracorporeal B-I anastomosis were performed in two porcine models. RESULTS: The virtual telesurgery study identified a latency time threshold of 125 ms. In the actual telesurgery setting, the latency time was 27 ms, including a 2-ms telecommunication network delay and a 25-ms local information process delay. After verifying the feasibility of the operative procedures using a gastrectomy model, two telesurgical gastrectomies were successfully completed without any unexpected events. No fluctuation was observed across the actual telesurgeries. CONCLUSION: Short-distance telesurgical robotic surgery for technically more demanding procedure may be safely conducted using the hinotori Surgical Robot System connected by high-speed optic-fiber communication.

Intravascular papillary endothelial hyperplasia in the cecum: a case report.

BACKGROUND:  Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumor, is a benign, non-neoplastic vascular lesion that is characterized by reactive proliferation of papillary endothelial cells associated with a thrombus. These lesions typically develop in the vascular regions of the head and neck, oral cavity, or extremities; however, other organ systems have been affected. IPEH in the gastrointestinal tract is rare, with only a few cases reported to date. Thus, the pathogenesis and clinical features of IPEH in the gastrointestinal tract are not entirely understood. Moreover, the local excision of certain subtypes of IPEH can be curative; this makes timely diagnosis essential. We present the case of a patient with IPEH in the cecum that was discovered while investigating the cause of severe anemia. CASE PRESENTATION: A 29-year-old woman visited a general practitioner (GP) with the complaint of abdominal pain. She was diagnosed with acute appendicitis and was prescribed antibiotics. After treatment, her abdominal pain disappeared. However, she was found to be severely anemic (hemoglobin level, 6.5 g/dl). To determine the cause of her anemia, the GP referred her to our hospital for further examination and treatment. Computed tomography scan revealed cecal wall thickening. Further, a lower gastrointestinal endoscopy revealed a 2-cm raised mass-like lesion in the cecum. This lesion was pathologically identified as an inflammatory granuloma. The cause of her anemia was determined to be bleeding from the lesion in the cecum. She underwent laparoscopic ileocecal resection. Histopathological examination of the surgical specimen revealed a spongy structure comprising many small papillary fibrous tissues lined by a typical monolayer endothelium. Further, immunohistochemical analysis showed that the cells of the endothelium monolayer expressed CD31, CD34. The Ki-67 labeling index was < 1%. Based on these findings, the lesion was identified as an IPEH in the cecum. The patient's postoperative course was uneventful, and there was no evidence of recurrence during the 1.3 years of follow-up. CONCLUSIONS:  IPEH rarely arises within the abdominal cavity. Surgery remains the only treatment for IPEH and is associated with an excellent prognosis and a low recurrence rate. More aggressive lesions such as angiosarcoma should be excluded when considering the histologic diagnoses of IPEH, and expert pathologic review is vital. This is the first report of IPEH occurring in the cecum and represents a novel cause of gastrointestinal bleeding which the clinician should consider when evaluating a patient with atypical or difficult gastrointestinal bleeding sources.

Reciprocating intestinal flows enhance glucose uptake in C. elegans.

Despite its physiological and pathological importance, the mechanical relationship between glucose uptake in the intestine and intestinal flows is unclear. In the intestine of the nematode Caenorhabditis elegans, the defecation motor program (DMP) causes reciprocating intestinal flows. Although the DMP is frequently activated in the intestines, its physiological function is unknown. We evaluated the mechanical signature of enhanced glucose uptake by the DMP in worms. Glucose uptake tended to increase with increasing flow velocity during the DMP because of mechanical mixing and transport. However, the increase in input energy required for the DMP was low compared with the calorie intake. The findings suggest that animals with gastrointestinal motility exploit the reciprocating intestinal flows caused by peristalsis to promote nutrient absorption by intestinal cells.

Caudal Approach to Laparoscopic Liver Resection-Conceptual Benefits for Repeated Multimodal Treatment for Hepatocellular Carcinoma and Extended Right Posterior Sectionectomy in the Left Lateral Position.

We had reported the novel concept of "caudal approach in laparoscopic liver resection" in 2013. In the first report, the caudal approach of laparoscopic transection-first posterior sectionectomy without prior mobilization of the liver in the left lateral position was described. Thereafter, 10 complex laparoscopic extended posterior sectionectomies with combined resection of the right hepatic vein or diaphragm were performed using the same approach. In the present study, the short-term outcomes of these cases and 42 cases of laparoscopic sectionectomies or hemi-hepatectomies (excluding left lateral sectionectomy) were compared. There was no statistically significant difference between the groups in terms of patients' backgrounds, diseases for resection, preoperative liver function, tumor number and size, as well as outcomes, operation time, intraoperative blood loss, morbidity, conversion to laparotomy, and post-operative hospital stay. Even complex laparoscopic extended posterior sectionectomy was safely performed using this procedure. This approach has the technical benefits of acquiring a well-opened transection plane between the resected liver fixed to the retroperitoneum and the residual liver sinking to the left with the force of gravity during parenchymal transection, and less bleeding from the right hepatic vein due to its higher position than the inferior vena cava. Furthermore, it has an oncological benefit similar to that of the anterior approach in open liver resection, even in posterior sectionectomy. The detailed procedure and general conceptual benefits of the caudal approach to laparoscopic liver resection for repeated multimodal treatment for hepatocellular carcinoma are described.

Influence of Respiratory Gas Density on Tidal Volume during Mechanical Ventilation: A Laboratory Investigation and Observational Study in Children.

Fluid mechanics show that high-density gases need more energy while flowing through a tube. Thus, high-density anesthetic gases consume more energy to flow and less energy for lung inflation during general anesthesia. However, its impact has not been studied. Therefore, this study aimed to investigate the effects of high-density anesthetic gases on tidal volume in laboratory and clinical settings. In the laboratory study, a test lung was ventilated at the same pressure-controlled ventilation with 22 different gas compositions (density range, 1.22-2.27 kg/m3) using an anesthesia machine. A pneumotachometer was used to record the tidal volume of the test lung and the respiratory gas composition; it showed that the tidal volume of the test lung decreased as the respiratory gas density increased. In the clinical study, the change in tidal volume per body weight, accompanied by gas composition change (2% sevoflurane in oxygen and with 0-30-60% of N2O), was recorded in 30 pediatric patients. The median tidal volume per body weight decreased by 10% when the respiratory gas density increased from 1.41 kg/m3 to 1.70 kg/m3, indicating a significant between-group difference (P < 0.0001). In both settings, an increase in respiratory gas density decreased the tidal volume during pressure-controlled ventilation, which could be explained by the fluid dynamics theory. This study clarified the detailed mechanism of high-density anesthetic gas reduced the tidal volume during mechanical ventilation and revealed that this phenomenon occurs during pediatric anesthesia, which facilitates further understanding of the mechanics of ventilation during anesthesia practice and respiratory physiology.

Morvan Syndrome Converted from Isaacs' Syndrome after Thymectomy with Positivity for Both Anti-LGI1 and Anti-CASPR2 Antibodies.

Anti-voltage-gated potassium channel complex antibodies-mediated disorder includes Isaacs' syndrome, which is characterized by neuromyotonia, and Morvan syndrome, which is characterized by neuromyotonia, encephalopathy and autonomic dysfunction. We herein report a patient with Morvan syndrome that converted from Isaacs' syndrome after thymectomy. The patient first presented with myospasm in all extremities and positivity for both anti-leucine-rich glioma inactivated 1 (LGI1) and anti-contactin-associated protein like 2 (CASPR2) antibodies and subsequently developed encephalopathy after thymectomy, which was successfully improved by immunotherapy. This is the first case of Morvan syndrome wherein thymectomy worsened Isaacs' syndrome, suggesting that immunotherapy should be considered for Isaacs' syndrome accompanied by positivity for both anti-LGI1 and anti-CASPR2 antibodies to prevent worsening to Morvan syndrome.