The impact of COVID-19 on Japanese patients with eosinophilic gastrointestinal disorders during the vaccination era

Background

Eosinophilic gastrointestinal disorders (EGIDs) are chronic allergic diseases categorized as eosinophilic esophagitis (EoE) and non-EoE EGIDs. Few studies regarding the association between EGIDs and coronavirus disease 2019 (COVID-19) have been reported. Although most Japanese individuals received the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, the incidence of COVID-19 remained high in 2022. This study examines the incidence of COVID-19 in patients with EGIDs during the vaccination era.

Methods

Patients with EGIDs who visited our department between October and December 2022 were enrolled in the study. The incidence and severity of COVID-19 prior to October 1, 2022 were determined. Patients who reported having COVID-19 also reported their hospitalization history, intensive care unit admissions, and EGID flares. The number of SARS-CoV-2 vaccinations received and treatment for EGIDs were obtained from the patients' medical records.

Results

Of 111 patients with EGIDs (65 with EoE and 46 with non-EoE EGIDs) included in this study, 31 (28%) patients reported having COVID-19, including 14 (22%) with EoE and 17 (37%) with non-EoE EGIDs. Fifty-nine (84%) patients received two or more vaccinations, and 11 (16%) patients received no vaccinations. COVID-19 was mild in all but one patient who had moderate symptoms. COVID-19 was not associated with EGID flares. EGID treatments and an unvaccinated status were not associated with an increased risk of COVID-19.

Conclusion

COVID-19 was mild in patients with EGIDs and not associated with EGIDs flares during the vaccination era. There was a relatively high incidence of COVID-19 among patients with non-EoE EGIDs.

Risk factors for adverse events associated with endoscopic submucosal dissection for superficial pharyngeal cancer

BACKGROUND

Superficial pharyngeal cancer can be treated with curative intent while preserving function using minimally invasive peroral endoscopic resection techniques such as endoscopic submucosal dissection (ESD). However, severe adverse events occasionally occur, such as laryngeal edema requiring temporary tracheotomy and fistula formation. Therefore, we investigated the risk factors for adverse events associated with ESD for superficial pharyngeal cancer.

METHODS

This retrospective observational study was conducted at a single institution, and 63 patients who underwent ESD were enrolled. The primary outcome was the risk factors for adverse events associated with ESD. The secondary outcomes were adverse events associated with ESD and their frequency.

RESULTS

The overall adverse event rate was 15.9% (10/63). The incidence of laryngeal edema requiring prophylactic temporary tracheotomy was 11.1%, while laryngeal edema requiring emergency temporary tracheotomy, postoperative bleeding, aspiration pneumonia, fistula, abscess, and stricture formation occurred in 1.6% of patients, respectively. Logistic regression analyses showed that a history of radiotherapy for head and neck cancer was a risk factor for adverse events (odds ratio [OR], 16.67; 95% confidence interval [CI], 3.04-91.34; p = 0.001). After adjusting the model for differences in the baseline risk factors using the inverse probability of treatment weighting method, the adverse events were found to increase in association with a history of radiotherapy for head and neck cancer (OR, 39.66; 95% CI,5.85-268.72; p < 0.001).

CONCLUSION

History of radiotherapy for head and neck cancer is an independent risk factor for adverse events associated with ESD for superficial pharyngeal cancer. Among adverse events, laryngeal edema requiring prophylactic temporary tracheotomy was particularly high.

Influence of a biliary stent in patients with advanced pancreatic cancer treated with modified FOLFIRINOX

Endoscopic biliary drainage is the recommended 1st-line treatment for malignant biliary obstruction. Although a high incidence of febrile neutropenia has been reported in patients treated with FOLFIRINOX and a biliary stent, it remains unknown whether the biliary stent contributes to patient survival. Thus, we aimed to elucidate the effects of biliary stents on the survival of patients with advanced pancreatic cancer treated with modified FOLFIRINOX (mFFX). We retrospectively reviewed medical charts of patients with advanced pancreatic cancer treated with mFFX between January 2014 and April 2020. We compared the overall survival (OS) of patients with and without biliary stent during mFFX treatment and examined the independent effect on mortality using propensity score matching. Overall, we included 89 patients (stent group, n = 24; non-stent group, n = 65). The proportion of patients with pancreatic head cancer was significantly higher in the stent group than in the non-stent group (P < .01). Stratification analysis in patients with pancreatic head cancer revealed that OS was significantly shorter in the stent group than in the non-stent group (P = .03). After propensity score matching, 19 pairs of patients in each group were analyzed. The stent group revealed a significantly shorter survival than the non-stent group (median OS, 10.3 vs 24.9 months; P < .01). The incidences of febrile neutropenia (P = .01) and biliary tract-related events that required biliary stenting or stent replacement (P < .01) were significantly higher in the stent group than in the non-stent group. Stent insertion was an independent risk factor for overall mortality. Biliary stents may reduce survival in patients with advanced pancreatic cancer. The rate of febrile neutropenia was higher in the stent group than in the non-stent group. There is a need to assess the patient's condition with discretion and develop a treatment strategy with short prognosis in mind after stent insertion.

P-754 Perinatal outcomes and congenital anomalies after clomiphene citrate based minimal ovarian stimulation in vitro fertilisation stratified by embryo transfer method: a 10-year cohort study

Study question

Is the embryo transfer method associated with perinatal outcomes and congenital anomalies after minimal ovarian stimulation in vitro fertilisation (IVF) with clomiphene citrate (CC)?

Summary answer

Single vitrified-warmed blastocyst transfers in natural cycles had a lower incidence of pregnancy complications compared to single fresh cleaved embryo transfers after CC-based ovarian stimulation.

What is known already

Pregnancies resulting from IVF are associated with a higher risk of adverse perinatal outcomes compared to spontaneous conception; therefore, the next focus in reproductive medicine is to assess whether the increased risks are attributable to the IVF. Perinatal outcomes and congenital anomalies should be considered in addition to pregnancy outcomes in selecting the embryo transfer method. However, studies describing the influence of transfer methods on perinatal and maternal outcomes are limited.

Study design, size, duration

This study retrospectively analysed a single centre 10-year cohort. A total of 82,491 clinical records of women who underwent oocyte retrieval during a CC-based minimal stimulation cycle followed by single fresh cleaved embryo transfer (SFCT), single vitrified-warmed cleaved embryo transfer (SVCT), or single vitrified-warmed blastocyst transfer (SVBT) at the Kato Ladies Clinic between January 2008 and December 2017 were retrospectively analysed.

Participants/materials, setting, methods

The oocyte retrievals were performed in CC-based minimal ovarian stimulation. The embryos were transferred 2–3 days after retrieval, or vitrified at the cleavage or blastocyst stages. The vitrified embryos were warmed and transferred within the natural cycles. Perinatal outcomes and congenital anomalies were stratified by the transfer method. Multivariate logistic regression analysis was performed to evaluate the effect of transfer methods on pregnancy complications and congenital anomalies.

Main results and the role of chance

The perinatal outcomes and congenital anomalies in 19,069 singleton pregnancies were analysed. Multivariate logistic regression analysis revealed that the incidence of hypertensive disorders of pregnancy was significantly lower in the SVBT group compared with the SFCT group (adjusted odds ratio [AOR], 0.628; P &lt; 0.0001). The incidence of low-lying placenta (AOR 0.359 P = 0.0483; AOR 0.452 P &lt; 0.0001, respectively) and placenta previa (AOR 0.300 P = 0.0021; AOR 0.542 P &lt; 0.0001, respectively) were lower in the SVCT and SVBT groups than in the SFCT group. The rate of preterm delivery was lower in SVBT compared with SFCT (AOR 0.732 P &lt; 0.0001). The rate of low birth weight was significantly lower after SVCT and SVBT, compared with the SFCT group (AOR 0.751; P = 0.0261: AOR, 0.560; P &lt; 0.0001: respectively). A lower incidence of small for gestational age (AOR 0.720 P = 0.0436; AOR 0.494 P &lt; 0.0001, respectively) and higher incidence of large for gestational age (AOR 1.287 P = 0.0332; AOR 1.706 P &lt; 0.0001, respectively) were observed in the SVCT and SVBT groups compared to the SFCT group. The incidence of each congenital anomaly was similar among the groups.

Limitations, reasons for caution

The data was collected through self-reported parental questionnaires on neonatal outcomes and congenital malformations. Furthermore, this study was retrospective in nature; further studies are necessary to ascertain the generalisability of these findings to other clinics with different protocols and/or patient demographics.

Wider implications of the findings

This study demonstrated reassuring outcomes for SVBT, in terms of a lower incidence of pregnancy complications compared with SFCT. Our findings provide valuable knowledge to improve perinatal outcomes in CC-based stimulation and to inform couples of the possible benefits and harms of each type of embryo transfer method.

Trial registration number

not applicable

Lustrous White Erosions Surrounded by an Erythematous Mucosa: A Novel Endoscopic Finding of Gastric Lesions in Patients with Wilson Disease

Wilson disease is an inherited copper metabolism disorder. We herein report a novel endoscopic finding in three men with Wilson disease. These patients underwent upper endoscopy due to gastrointestinal symptoms or during follow-up. In each case, endoscopy revealed lustrous white erosions surrounded by an erythematous mucosa in the greater curvature of the gastric body. A biopsy of the lesions showed orcein-positive tissue, indicating copper deposition, in the interstitial stroma and fundic glands of the mucosa. All patients had been receiving treatment with zinc acetate. These endoscopic findings might have been related to the cytotoxicity of the accumulated copper and zinc acetate.

Angle of covered self-expandable metallic stents after placement is a risk factor for recurrent biliary obstruction

BACKGROUND

Studies have shown that covered self-expandable metallic stents (CSEMS) with a low axial forces after placement can cause early recurrent biliary obstruction (RBO) due to precipitating sludge formation.

AIM

To ascertain whether the angle of CSEMS after placement is a risk factor for RBO in unresectable distal malignant biliary obstruction (MBO).

METHODS

Between January 2010 and March 2019, 261 consecutive patients underwent self-expandable metallic stent insertion by endoscopic retrograde cholangiopancreatography at our facility, and 87 patients were included in this study. We evaluated the risk factors for RBO, including the angle of CSEMS after placement as the primary outcome. We measured the obtuse angle of CSEMS after placement on an abdominal radiograph using the SYNAPSE PACS system. We also evaluated technical and functional success, adverse events, time to RBO (TRBO), non-RBO rate, survival time, cause of RBO, and reintervention procedure as secondary outcomes.

RESULTS

We divided the patients into two cohorts based on the presence or absence of RBO. The angle of CSEMS after placement (per 1° and per 10°) was evaluated using the multivariate Cox proportional hazard analysis, which was an independent risk factor for RBO in unresectable distal MBO [hazard ratio, 0.97 and 0.71; 95% confidence interval (CI): 0.94-0.99 and 0.54-0.92; P = 0.01 and 0.01, respectively]. For early diagnosis of RBO, the cut-off value of the angle of CSEMS after placement using the receiver operating characteristic curve was 130° [sensitivity, 50.0%; specificity 85.5%; area under the curve 0.70 (95%CI: 0.57-0.84)]. TRBO in the < 130° angle group was significantly shorter than that in the ≥ 130° angle group (P < 0.01).

CONCLUSION

This study suggests that the angle of the CSEMS after placement for unresectable distal MBO is a risk factor for RBO. These novel results provide pertinent information for future stent management.

[Current real-world treatments for Japanese patients with eosinophilic esophagitis]

A total of 306 patients with eosinophilic esophagitis (EoE) were analyzed at our department. Proton pump inhibitors or potassium-competitive acid blockers were used as the first-line treatment in 286 (93.5%) patients. Fifty-five (18.0%) patients received topical steroid swallowing therapy. During 17.7-month mean follow-up, 46.4% of the patients were followed-up with no medications, 37.3% of the patients received maintenance or on-demand therapy using acid-suppressive drugs, and 9.8% of the patients received maintenance therapy with steroid swallowing. The majority of patients with EoE were treated using a therapeutic strategy similar to that used for gastroesophageal reflux disease. However, some patients were refractory to the treatment. Current real-world treatment strategies for Japanese patients with EoE are clarified.

Evaluation of long-term survival in patients with severe comorbidities after endoscopic submucosal dissection for esophageal squamous cell carcinoma

BACKGROUND

Endoscopic submucosal dissection (ESD) is becoming widely popular as a less invasive treatment option for superficial esophageal squamous cell carcinoma. However, data on long-term survival after esophageal ESD in patients with severe comorbidities are limited. This study aimed to evaluate long-term survival after ESD in such patients.

METHODS

Altogether, 584 consecutive patients underwent esophageal ESD at our institution from May 2004 to September 2016. Based on the American Society of Anesthesiologists Physical Status (ASA-PS) classification system, patients were grouped according to severe (ASA-PS ≥ 3) or non-severe comorbidities (ASA-PS 1/2). The overall survival (OS), disease-specific survival (DSS), and risk factors for mortality were compared between the groups using a propensity score matching analysis.

RESULTS

In a matched cohort of 69 pairs, the 5-year OS rate was poorer in ASA-PS 3 patients than in ASA-PS 1/2 patients (63.9% vs. 92.5%, P < 0.01), while the 5-year DSS rate was similar between the groups (100% vs. 100%). The mortality rate was significantly higher in ASA-PS 3 patients than in ASA-PS 1/2 patients (hazard ratio 3.47; 95% confidence interval 1.79-6.74; P < 0.01). Death due to exacerbation of comorbidities was significantly more frequent in ASA-PS 3 patients than in ASA-PS 1/2 patients (42.4% vs. 8.3%, P < 0.04).

CONCLUSION

Because of the exacerbation of comorbidities, patients with severe comorbidities had poorer long-term outcomes after esophageal ESD than those with non-severe comorbidities. Further studies will be necessary to evaluate esophageal ESD in patients with severe comorbidities.

Comparison of the Diagnostic Efficiency of Radial- and Convex-Arrayed Echoendoscopes for Indirect Findings of Pancreatic Cancer: A Retrospective Comparative Study Using Propensity Score Method

Simple Summary

Pancreatic cancer (PC) has a poor prognosis; however, diagnosing PC at an earlier stage could improve long-term patient outcomes. Endoscopic ultrasonography (EUS) plays an important role in PC detection, and the indirect findings (caliber change, retention cysts, and dilatation of the branch duct) that are detected by EUS are especially important for the early detection of PC. The aim of this retrospective study was to compare the diagnostic efficacy of radial- and convex-arrayed echoendoscope for the detection rate of indirect findings. As a result, the radial-arrayed echoendoscope was found to be an independent detection factor of indirect findings by multivariate analysis. The radial-arrayed echoendoscope is useful for the detection of indirect findings.

Abstract

Endoscopic ultrasonography (EUS) is useful for detecting early-stage pancreatic cancer. Because the detection of small lesions is difficult, it is important to detect indirect findings, namely caliber change, retention cysts, and dilatation of the branch duct, during the procedure. Although two types of EUS endoscopes are frequently used, there is no comparative study on their efficacy for detecting indirect findings. Therefore, we aimed to compare the diagnostic efficacy of these two types for indirect findings. We retrospectively analyzed 316 consecutive patients who had undergone EUS for pancreaticobiliary disease at a single center between January 2017 and December 2018. The main outcome was the detection rate of indirect findings and its comparison between the two echoendoscope types. This outcome was achieved using the inverse probability of treatment weighting (IPTW) analysis. The detection rate of indirect findings was higher for the radial-arrayed endoscope than for the convex-arrayed echoendoscope (9.2% vs. 2.3% (p = 0.02)). The univariate analysis also revealed that the radial-arrayed echoendoscope was significantly superior to the convex-arrayed echoendoscope in terms of the detection of indirect findings (odds ratio, 5.94; 95% confidence interval, 1.68–21.10; p = 0.01) after IPTW. After adjustment for magnetic resonance imaging (MRI) and computed tomography (CT), radial-arrayed echoendoscope remained an independent factor for indirect finding detection (odds ratio, 6.04; 95% confidence interval, 1.74–21.00; p = 0.01). Finally, five patients who had indirect EUS findings were diagnosed with pancreatic cancer. Our results indicate that the radial-arrayed echoendoscope is useful for the detection of indirect findings.

Endoscopic findings of gastric lesions in patients with eosinophilic gastrointestinal disorders

Background and study aims  Eosinophilic gastrointestinal disorders are classified into eosinophilic esophagitis, eosinophilic gastritis, eosinophilic gastroenteritis, and eosinophilic colitis according to the site of eosinophilic infiltration. Although well established in eosinophilic esophagitis, endoscopic findings in eosinophilic gastritis and eosinophilic gastroenteritis with regard to gastric lesions have not been clearly described. The aim of this study was to identify endoscopic findings of gastric lesions associated with eosinophilic gastrointestinal disorders. Patients and methods  Out of 278 patients with eosinophilic gastrointestinal disorders, 18 had eosinophilic gastritis or eosinophilic gastroenteritis confirmed by biopsy; their endoscopic images were analyzed retrospectively. The association between endoscopic findings and number of eosinophils in the gastric mucosa was investigated. Results  Erythema was most frequently observed (72 %), followed by ulcers (39 %), discoloration (33 %), erosions (28 %), nodularity (28 %), and polyps (28 %). There were several unique endoscopic findings such as submucosal tumor-like deep large ulcers in three patients, antral Penthorum -like appearances (small nodules radially lined toward the pyloric ring) in three patients, "muskmelon-like appearances" (discolored mucosa-composed mesh pattern) in three patients, multiple white granular elevations in two patients, cracks (appearance of furrows similar to those in eosinophilic esophagitis) in five patients, and antral rings in one patient. No significant association was observed between endoscopic findings and number of gastric eosinophils. Conclusions  Several unique endoscopic findings of gastric lesions were observed in patients with eosinophilic gastritis or eosinophilic gastroenteritis. Submucosal tumor-like ulcers, antral Penthorum -like appearances, muskmelon-like appearances, and cracks might be associated with eosinophilic gastrointestinal disorders.

The usefulness of serial pancreatic juice aspiration cytological examination for pancreatic cancer not diagnosed by EUS-FNAB

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) is safe and useful for the diagnosis of pancreatic cancer. However, sometimes a diagnosis cannot be established by EUS-FNAB. The efficacy of serial pancreatic juice aspiration cytological examination (SPACE) for pancreatic cancer was reported. SPACE may be useful in cases in which diagnosis by EUS-FNAB is difficult; however, this has not been reported previously. We herein report two cases of pancreatic cancer diagnosed by SPACE when diagnosis by EUS-FNAB was difficult. Case 1 was a 77-year-old female. She was suspected of pancreatic cancer because of new-onset diabetes. We performed EUS-FNAB to the lesion in the pancreatic body; however, diagnosis failed. We performed SPACE and diagnosed pancreatic cancer finally. Case 2 was 72 years old female. She was suspected of having pancreatic cancer because of the dilatation of the pancreatic duct. We performed EUS-FNAB twice to the lesion in the pancreatic head, however, diagnosis failed. Therefore, we performed SPACE and got final diagnosis as pancreatic cancer. From our experience, we suggest that SPACE is a useful diagnostic method for patients with pancreatic cancer that are difficult to diagnose.

Neutralization of the Local Negative Charge Carried by Glycoprotein (GP)-Ib in Ristocetin-Induced Platelet Agglutination

Pretreatment of platelets with chymotrypsin dose-dependently decreased glycoprotein (GP)-Ib amounts as measured by SDS- PAGE, ristocetin-induced agglutination and platelet electrophoretic mobility (EPM). Decrease in platelet EPM in response to 0.75 mg/ml ristocetin alone were 7.0 ± 2.3 and 6.8 ± 4.3% (M ± S.E., n = 6) for control and chymotrypsin-treated platelets, respectively (p >0.2). Von Willebrand factor (vWF) alone had no effect on platelet EPM. However, in the presence of 0.75 mg/ml ristocetin, added vWF (2.9 μg/ml) caused a further 6.3 ± 3.8% decrease in control platelet EPM, but caused no significant decrease in the enzyme-treated platelets (p >0.05). In the presence of 0.3 mg/ml ristocetin, added vWF (2.9-14.5 μg/ml) caused a small but significant decrease in control platelet EPM, but caused no significant decrease in the enzyme-treated platelets.

These findings suggested that the GP-Ib carrying negative charge decreased by binding of vWF might facilitate a mutual approach of the GP-Ib molecules and bridge formation by vWF between different platelets.

Localization of a Thrombin-Binding Site on Human Platelet Membrane Glycoprotein Ib Determined by a Monoclonal Antibody

To determine a thrombin-binding site on GPIbα on platelet membrane, we have examined the binding activities of tryptic or chymotryptic fragments of purified GPIbα to a monoclonal antibody against GPIb (TM60) and thrombin using (immuno) affinity chromatography. When purified GPIba was digested with trypsin, two fragments (94-kDa, and 43-kDa) were obtained. The 43-kDa fragment was shown to bind to both affinity columns of TM60- and thrombin-Affi-Gel, while the 94-kDa fragment did not bind to either Affi-Gel columns. When trypsin fragments were incubated with TM60 and then applied to the column of thrombin-Affi-Gel, neither fragments were bound to the column. When the same experiment was performed using chymotrypsin, three fragments (94-kDa, 45-kDa and 39-kDa) were observed. On TM60- and thrombin-Affi-Gel columns, the smaller fragments (45-kDa and 39-kDa) were bound to the column. After incubation of these fragments with TM60, neither bound to the thrombin column. These results indicate (i) that the epitope for TM60 is located near, or on the thrombin-binding site of GPIba, and (ii) that the thrombin-binding site is located on the tail portion of GPIbα, especially on a chymotrypsin cleavage site.

Development of a robotic endoscope that locomotes in the colon with flexible helical fins

The purpose of this study was to develop a robotic endoscope that is low invasive, easy to operate and capable of locomotion from the rectum to the appendix in the human body. We believe that it would contribute to relieving pain in patients. We therefore developed a robotic endoscope that consists of a front and rear body with clockwise and anticlockwise helical fins, respectively. The front and rear bodies are connected via a DC motor. This robot moves forward in the colon by rotating the front body in the clockwise direction and the rear body in the anticlockwise direction. In addition, the radius of each helical fin can be changed by blowing air into a balloon implemented under each fin using an air compressor. Before experiments with animals, we performed experiments to evaluate the mechanical performance and safety of the robot. We confirmed that the maximum radius of the fins was less than the maximum radius of the colon by blowing air continuously into the balloons. We then confirmed that the robot can locomote in the colon without invasion of scratch and make short hole by performing an in-vivo experiment in live swine.

Effectiveness of endoscopic surgery training for medical students using a virtual reality simulator versus a box trainer: a randomized controlled trial

BACKGROUND

The first step toward increasing the level of patient safety in endoscopic surgery is for all endoscopic surgeons to acquire fundamental skills, including psychomotor skills, in the preoperation stage of training. The current study aimed to evaluate the effectiveness of virtual reality (VR) simulator training and box training for training the fundamental skills of endoscopic surgery.

METHODS

For this study, 35 medical students at Kyushu University were divided into three groups: simulator (SIM) group (n = 20), box trainer (BOX) group (n = 20), and control group (n = 15). None of the students had any experience assisting with endoscopic surgery or any previous training for endoscopic surgery. The students in the SIM group underwent training using a VR simulator, the Procedicus MIST, 2 h per day for 2 days. The students in the BOX group underwent training using a box trainer 2 h per day for 2 days. The students in the control group watched an educational video for 30 min. The endoscopic surgical skills of all the students were evaluated before and after training with a task of suturing and knot tying using a box trainer.

RESULTS

Although no significant differences were found between the three groups in the total time taken to complete the evaluation task before training, there were significant improvements in the SIM and BOX groups after training compared with the control group. Box training increased errors during the task, but simulator training did not.

CONCLUSION

The findings showed that box training and VR training have different outcomes. The authors expect that the best curriculum for their training center would involve a combination that uses the merits of both methods.

Robotic laparoscopic distal gastrectomy: a comparison of the da Vinci and Zeus systems

BACKGROUND

The robotic surgical systems working on a master-slave principle have been developed and used in the worldwide in cardiac, urologic, and general surgery.

METHODS

The two robotic systems, the da Vinci and the Zeus Robotic Surgical System (Intuitive Surgical, Calif., USA), were compared with the aim of evaluating operative feasibility and technical efficacy in distal gastrectomy.

RESULTS

During laparoscopic gastrectomy, the da Vinci System (n = 2) had a shorter total operative time (445 versus 656 minutes; p = 0.09) and less blood loss (65 versus 277 mL; p = 0.08) compared with the Zeus System (n = 3). The articulated instruments of both systems were useful in lymph node dissection, isolation of vessels in fat tissue, ligation of vessels, and intraabdominal anastomosis of the gastrointestinal tract. Robotic laparoscopic procedures can be performed effectively using either the da Vinci or Zeus System.

CONCLUSION

In this limited study, the robotic instruments, especially those of da Vinci system, made it easier to complete tissue dissection including lymph nodes, complicated endoscopic anastomoses, and ligatures in a closed cavity.

Interventional navigation for abdominal therapy based on simultaneous use of MRI and ultrasound

An interventional navigation system designed for percutaneous abdominal therapies was proposed, and a pilot study was carried out to assess the proposed system. Integration of US to MRI-based segmentation and 3D display of tumours can help physicians deal with instabilities such as respiratory motion and soft tissue shift that are inherent in abdominal interventions. In addition to the 3D display of the needle and tumours, we adapted the system for the abdominal applications and incorporated a process to correct the mismatch in needle path between MRI and US. The preliminary results of phantom and animal experiments indicated that the proposed method could combine the advantages of both MRI and US. The time required to determine the optimal needle insertion path by using this system was significantly less than that required when either US or MRI guidance alone was employed. The developed system was applied in two patients who underwent PEIT therapy, and its clinical feasibility was partially confirmed.

Development and assessment of morphologic criteria for diagnosing gastric cancer using confocal endomicroscopy: an ex vivo and in vivo study

BACKGROUND AND STUDY AIMS

The Confocal Endomicroscopy System (Optiscan Pty Ltd. and Pentax Corp.) is a newly developed imaging tool that uses laser light and optical technology to visualize living tissue at the cellular level. Digital images of cells magnified 1000-fold appear in real time on a computer screen, which enables immediate detection of changes in cellular structure without the need for a biopsy. The aim of this study was to assess the features of the cellular architecture of cancerous tissue that can be used in the differential diagnosis of cancerous tissue and normal mucosa using this system's image-processing software.

PATIENTS AND METHODS

A total of 27 gastric cancers were examined ex vivo using confocal endomicroscopy. A fluorescent contrast agent, acriflavine, was applied topically to normal and to cancerous mucosa. In vivo imaging of the gastric mucosa after intravenous injection of fluorescein sodium was also performed in nine patients with gastritis or gastric cancer.

RESULTS

The nuclear area in the ex vivo specimens was calculated using Scion Image software. The mean nuclear area of cancer cells was found to be significantly larger than that of normal cells in 18/27 gastric cancers (67 %). The mean nuclear area of the cancers tended to be larger than that of normal mucosa, especially in cases of differentiated adenocarcinoma. In more than half the cases, it was possible to diagnose malignancy automatically using confocal endomicroscopy and image-processing software without the need for biopsy and pathological examination. In vivo imaging of cancerous lesions showed irregularity in cellularity and vascularity.

CONCLUSION

The ability of this imaging device to differentiate between normal tissue and cancerous tissues gives it potential value as a new screening tool for early detection of malignancy.

Laparoscopic cholecystectomy using a newly developed laparoscope manipulator for 10 patients with cholelithiasis

BACKGROUND

Laparoscopic surgery has continued to gain popularity in almost all fields of abdominal surgery, and robotic systems have been introduced in general surgery. Naviot is a new remote-controlled laparoscope manipulator system controlled by the operator's hand. This study assessed its introduction into clinical practice.

METHODS

A group of 10 consecutive patients with cholelithiasis underwent laparoscopic cholecystectomy assisted by the Naviot system (Naviot group). Another group of 41 patients who underwent laparoscopic cholecystectomy with a conventional human camera holder (human camera group) were selected for a comparison of their operative results with those of the Naviot group.

RESULTS

The operative time of 89.3 +/- 27.1 min for the Naviot group was significantly longer than that of 74.8 +/- 28.1 min for the human camera group (p < 0.05). However, when the setup time for the Naviot system was excluded, the operative time was not significantly different from that for the human camera group. Other operative results showed no significant difference between the two groups.

CONCLUSIONS

The authors believe that the new Naviot system is feasible for clinical use, and that it enables surgeons to perform solo gastrointestinal surgery.

Hyperbilirubinemia induced by endoscopic variceal ligation for esophageal varices in a patient with primary biliary cirrhosis: a case report

We describe the case of a 51-year-old woman with primary biliary cirrhosis who developed hyperbilirubinemia with transient liver dysfunction after undergoing endoscopic variceral ligation to control hemorrhaging from esophageal varices. After undergoing a variceal ligation, the serum total bilirubin increased from 4.0 mg/dL to 9.5 mg/dL, and the degree of liver failure worsened. She finally had to undergo a liver transplant. We discuss the mechanism of hyperbilirubinemia after endoscopic variceal ligation.

Acquired storage-pool disorders occurring late after allogeneic bone marrow transplantation: partial activation of platelets in asymptomatic patients

Bone marrow transplantation (BMT) may be complicated by coagulation abnormalities. The present study evaluated whether platelets might be activated in patients who had undergone BMT without significant coagulopathy. The patients selected had received allogeneic BMTs a median of 39 months before the study (range, 11-124 months) and had not received cyclosporine, FK506 (tacrolimus), or other medication affecting cyclo-oxygenase for at least 3 months prior to the collection of blood samples. Furthermore, patients had platelet counts greater than 100 x 10(9) cells/L and normal serum creatinine levels. Twenty-five healthy volunteers acted as controls. Platelet aggregation studies and a mepacrine assay of platelets showed abnormal aggregation and decreased staining in some patients. The platelet storage-pool adenosine 5'-triphosphate (ATP) level in 15 patients after BMT was 0.45+/-0.24 micromol per 10(11) platelets, whereas the level in 18 controls was 1.03+/-0.36 micromol per 10(11) platelets (P = .00078). The total ATP levels of platelets in patients and controls were 4.33+/-1.14 and 5.63+/-1.51 micromol per 10(11) platelets, respectively (P = .016). With the exception of 1 patient, plasma levels of thrombomodulin and von Willebrand factor were all within the normal range. The average plasma level of 11-dehydrothromboxane B2 was significantly increased in 15 patients after BMT compared with controls, 20.6+/-8.2 and 10.3+/-1.2 pg/mL, respectively (P = .0004). These findings suggest a long-term process of platelet activation in patients after BMT and, following the cessation of cyclosporine, development of acquired storage-pool disorder of platelets.

The therapeutic strategies in performing emergency surgery for gastroduodenal ulcer perforation in 130 patients over 70 years of age

BACKGROUND/AIMS

Gastroduodenal ulcer is a very common illness in Japan. As the number of elderly persons in Japan increases the same as in Europe and America, the number of such patients requiring a gastroduodenal emergency operation has also increased. Regarding the complications of peptic ulcer, a perforation remains the most important fatal complication. The aim of this study is to investigate the operative risk factors and the long-term recurrence rates and to define the optimal surgical procedures in emergency situations in elderly patients.

METHODOLOGY

From April 1988 through March 1997, 130 patients over 70 years of age with a perforated gastroduodenal ulcer (a duodenal ulcer perforation in 50 patients and a gastric ulcer perforation in 80 patients) were operated on in an emergency situation in our clinic. We investigated the following items; medical illness, preoperative risk factor, optimal surgical procedure, postoperative organ failure and the cumulative recurrence-free rates after surgical treatment.

RESULTS

A significant correlation with mortality was observed in patients with established comorbidity in the following organs: lung (P = 0.03), heart (P = 0.02), kidney (P = 0.04), and diabetes (P = 0.03). The highest postoperative mortality rate was recorded in patients who underwent a simple closure of a duodenal ulcer perforation (4 patients; 26.7%), while the lowest postoperative mortality rate was recorded in patients who underwent a simple closure and vagotomy of a duodenal ulcer perforation (3 patients; 12.5%). In gastric ulcers, the mortality rate in patients with a gastrectomy was significantly higher than in patients with a simple closure. The practical application of the three risk factors (preoperative shock, delay to surgery over 24 hours, and medical illness) was shown by the progressive rise in the mortality rate with the increasing number of risk factors. Based on the 5 postoperative years after treating a perforated duodenal ulcer, the cumulative recurrence rate after a simple closure (63.6%) was significantly higher than that after a simple closure and vagotomy (38.1%) (n = 0.02) or after gastrectomy (0%) (P < 0.001). At 5 years postoperatively, the cumulative recurrence rate after a simple closure (41.2%) was significantly higher than that after a gastrectomy (15.9%) (P < 0.01).

CONCLUSIONS

In conclusion, in an emergency situation, elderly patients are in a highly unfavorable prognostic condition due to their advanced age, and comorbidity, which thus leads to poorer results, not only worldwide, but also in Japan. Based on our findings, in duodenal ulcer cases, a simple closure and vagotomy is recommended because of its low mortality and minimal stress, except for cases with a giant perforation measuring over 20 mm in diameter at the perforation hole or with severe duodenal stenosis. In stomach ulcer cases, a gastrectomy may be recommended because of its low recurrence rate.

Effectiveness of gastric devascularization and splenectomy for patients with gastric varices

BACKGROUND

Bleeding from gastric varices is difficult to control and has a high mortality rate. Recently, newly developed treatments for this serious lesion have been used, but surgical intervention is still advocated by several studies. We report our experience with gastric devascularization and splenectomy and its effectiveness for patients with gastric varices.

STUDY DESIGN

Gastric devascularization and splenectomy was successfully performed to treat patients with isolated gastric varices (n = 42). The patients included 27 men and 15 women who ranged from 29 to 73 years of age (average 53.7 years). We analyzed the findings of gastric varices using endoscopy, the results of gastric devascularization and splenectomy, and survival after the operation.

RESULTS

No patient had tortuous varices (F1). Twenty-seven patients (64.3%) had nodular varices (F2) and 15 (35.7%) had tumorous varices (F3). Twenty-five patients (59.5%) had large varices that occupied two or more areas. Twenty-nine patients (69.0%) had varices with a positive red color sign. No major complications during or after the operation were observed, and peri-operative death did not occur. Gastric varices were eradicated in all 42 patients. Survival rates were 97.6% after 1 year, 88.1% after 3 years, 76.2% after 5 years (mean followup period, 46 months).

CONCLUSIONS

This study showed that gastric devascularization and splenectomy provides satisfactory results for patients with gastric varices that are likely to bleed and that it can be performed even on patients who have had other treatments.

Endoscopic ligation of oesophageal varices compared with injection sclerotherapy in primary biliary cirrhosis

BACKGROUND AND AIMS

Oesophageal varices are an important complication in primary biliary cirrhosis (PBC). However, there have yet to be any studies made on treatment of oesophageal varices in PBC. We therefore studied the efficacy and related complications of endoscopic variceal ligation (EVL) and endoscopic injection sclerotherapy (EIS) as an initial treatment in primary biliary cirrhotic patients.

METHODS

From December 1985 to March 1999, 29 biliary cirrhotic Japanese patients with portal hypertension and oesophageal varices were treated in our clinics. Eleven patients were treated with EVL and EIS, and 18 patients underwent EIS only. The liver function, renal function and respiratory function were studied before and after endoscopic treatment and any complications were also examined.

RESULTS

In stages III and IV, significant differences were observed in the serum levels for total bilirubin and gamma-glutamic pyruvic transaminase only in the EIS group. Significant differences were observed in the rate of appearance of pyrexia, retrosternal pain and pleural effusion between the EIS and EVL groups.

CONCLUSION

EVL significantly reduced the adverse effects associated with EIS at the initial session in primary biliary cirrhotic patients.

Role of nitric oxide and endothelin-1 in a portal hypertensive rat model

BACKGROUND

Portal hypertension is often accompanied by a hyperdynamic circulation state. Some reports have suggested that nitric oxide (NO) plays an important role in this hyperdynamic state. On the other hand, although endothelin (ET)-1, a powerful vasoconstrictor, was recently identified, little is known about its role in portal hypertension or about the interaction between NO and ET-1. The aim of this study was therefore to investigate whether or not the inhibitor of NO synthase (NOS) might improve portal hypertension, and also to clarify the relationship between NO and ET-1.

METHODS

Portal hypertensive (PHT) rats, in which hypertension was induced by a two-step ligation of the portal vein (PVL), were used. The mean arterial pressure (MAP), portal pressure (PP), visceral blood flow volume (BFV), and serum levels of NO and ET-1 were determined in PVL rats treated with two NOS inhibitors with different functions: N(G)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine (AG). Control (CTR) rats. treated by a sham operation (SO), were also studied.

RESULTS

Two-step PVL treatment induced a significant increase in the serum level of NO3-and ET-1 in the portal vein. L-NAME and AG administration significantly decreased PP at doses of 50 mg/kg in PHT rats after 60 min administration, while no inhibitor effected any modification in the CTBR rats. Both NOS inhibitors increased MAP and decreased PP and BFV in the portal vein, gastric mucosa, and spleen, in addition to decreasing the serum levels of NO3- and ET-1 in the PHT rats, while neither blockade modified any parameters in the CTR rats. In PHT rats, L-arginine, a NO substance, reversed the effect of L-NAME, while it did not induce any recovery from the AG effect.

CONCLUSIONS

In PHT rats, NO seems to contribute to portal hypertension. PVL increases not only the serum level of NO3-, but also that of ET-1 in the portal vein. Both L-NAME and AG reduce PP and BFV of the portal vein, spleen, gastric mucosa. and liver. In addition, the inhibition of NOS diminishes the serum level not only of NO, but also of ET-1. Use of an appropriate NOS inhibitor may therefore positively affect the hyperdynamic state in portal hypertension.

PS-liposome and ox-LDL bind to different sites of the immunodominant domain (#155-183) of CD36: a study with GS95, a new anti-CD36 monoclonal antibody

CD36, a multifunctional adhesive receptor on a variety of cells such as monocytes and platelets, has been implicated in clearance of modified LDL and in the removal of apoptotic or senescent cells. We recently developed a new anti-CD36 monoclonal antibody, GS95. We determined the binding site of phosphatidylserine (PS)-liposome on CD36 by flow cytometric analysis of competitive bindings between phospholipid-liposomes or synthetic CD36 peptides and FITC-labeled anti-CD36 antibodies (GS95, OKM5, and FA6-152). The epitope of GS95 was mapped to the amino acid sequence #162-183 of CD36 that was partially overlapped with, but distinct from, #155-183, which has been reported as the epitopes of two commercially available antibodies, OKM5 and FA6-152. Oxidized-LDL dose-dependently inhibited bindings of both GS95 and OKM5 antibodies to platelet CD36, while PS-liposome inhibited the binding of GS95 but not OKM5 or FA6-152. These results indicate that the binding site of PS-liposome on platelet CD36 is not identical to that of oxidized-LDL and may be located in the amino acid sequence #162-183.

Role of endothelin-1 in congestive gastropathy in portal hypertensive rats

BACKGROUND

The aim of this study was to determine the role of endothelin (ET)-1 in portal hypertensive gastropathy (PHG) under portal hypertension, in order to investigate whether the ET(A/B) receptor inhibitor improves the permeability of gastric mucosal microvessels in PHG.

METHODS AND RESULTS

Portal hypertensive rats (PVL) and sham-operated rats (CTR) were prepared and then the concentration of plasma ET-1 was measured and the vasopressor response to ET-1 was compared between the two groups. The plasma ET-1 levels in PVL increased significantly compared with CTR; however, the vasopressor response to ET-1 in PVL decreased more than in CTR. Next, the portal venous pressure was measured in both CTR and PVL pretreated with or without a nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), before the injection of ET-1. The portal venous pressure of PVL after receiving ET-1 and being pretreated with L-NAME significantly increased in comparison to the pressure of PVL treated with ET-1 alone (without L-NAME). Moreover, Evans-Blue was injected into each rat and the absorbancy of the gastric contents was measured. The absorbancy of Evans-Blue in PVL increased significantly compared with CTR; however, the absorbancy in PVL+ ET(A/B) receptor inhibitor (Ro47-0203) decreased significantly more than in PVL.

CONCLUSIONS

This study showed that ET-1 is a potent vasoconstrictive substance that also has a transitory vasodilative response through NO induced by ET-1 in portal hypertension. In addition, it was found that the vascular permeability of the gastric mucosa increased in portal hypertension and that Ro47-0203 inhibited the hyper-permeability. Accordingly, ET-1 may, thus, play an important role in the development of PHG through NO induced by ET-1. Ro47-0203 may, therefore, be a useful substance for improving PHG in portal hypertension.

Translocation of sLe(x) on the azurophilic granule membrane to the plasma membrane in activated human neutrophils

Using immunogold electron microscopy, we found that human neutrophilic sialyl Lewis x (sLe(x)), an adhesive ligand for selectins, detectable by a monoclonal antibody, KM-93, is present in the sacculi of the Golgi apparatus as well as on the membranes of large electron-lucent azurophilic granules and the plasma membrane, including surface projections and microvilli. Neutrophilic sLe(x), however, was not detected on the membranes of specific granules. In comparison with the distribution of sLe(x), CD18 was localized on the plasma membrane and specific granule membrane but not on the azurophilic granule membrane. We also found by immunogold electron microscopy and flow cytometry that treatment of neutrophils with sialidase resulted in a loss of sLex on the plasma membrane. In contrast, intracellular sLex on the azurophilic granule membrane was not destroyed by sialidase. When sialidase-treated neutrophils were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), an inflammatory mediator peptide, in the presence of cytochalasin B, we observed by immunogold electron microscopy and flow cytometry that sLe(x) again appeared on the plasma membrane. These results indicate that stimulation by fMLP induces the up-regulation of sLe(x) on the cell surface by promoting translocation of sLe(x) from the azurophilic granule membrane to the plasma membrane in human neutrophils.

Leiomyosarcoma of the thyroid gland with rapid growth and tracheal obstruction: A partial thyroidectomy and tracheostomy using an ultrasonically activated scalpel can be safely performed with less bleeding

Primary leiomyosarcoma of the thyroid gland is rare, and to the best of our knowledge only nine well-documented cases have been previously reported in the world literature. We herein report a 90-year-old female patient with primary leiomyosarcoma of the thyroid gland who showed a rapid tumor growth and tracheal obstruction. The patient was successfully treated by a partial resection of the thyroid gland using an ultrasonically activated scalpel and emergency tracheostomy. Immunohistochemically, the tumor cells showed positive reactivity to smooth muscle actin and negative reactivity to thyroglobin. Palliative surgery successfully allowed the patient to recover from the symptoms of dyspnea related to this rare disease. The use of an ultrasonically activated scalpel and tracheostomy thus allowed us to safely perform a thyroidectomy with substantially less bleeding than normal.

The effect of carbon dioxide pneumoperitoneum on the portal hemodynamics in a portal-hypertensive rat model

As use of laparoscopic surgery grows, various complications with pneumoperitoneum have been reported. However, there are no reports on the relation between the carbon dioxide (Co2) pneumoperitoneum and portal hemodynamics. The purpose of this study was to determine how the pneumoperitoneum affects the portal hypertensive state. Portal-hypertensive rats, control rats, and sham operation rats were studied. The mean arterial pressure, portal venous pressure, central venous pressure, red blood flow volume of the viscera, and liver and renal function were investigated. The findings of this study suggest that Co2 pneumoperitoneum at less than 10 mm Hg does not present any undue risk to the portal hemodynamics in portal-hypertensive rats; however, more attention should be paid to the IAP in PHT patients undergoing surgery.

Laparoscopic splenectomy for splenic artery aneurysm

Two cases undergoing a laparoscopic splenectomy for the treatment of a splenic artery aneurysm are herein reported. This lesion is relatively rare. Surgical treatment is indicated for such cases since approximately 10% of these aneurysms tend to rupture which thus results in fatal hemorrhaging. Both cases demonstrated aneurysms measuring more than 2 cm in diameter based on the ultrasonography, computed tomography and celiac angiography findings and, as a result, a laparoscopic splenectomy was thus prophylactically performed. This procedure is the preferred technique for high risk patients, such as those with chronic renal failure, as observed in case 1, since patients can be spared the disadvantages of undergoing a laparotomy.

Results of laparoscopic splenectomy for immune thrombocytopenic purpura

BACKGROUND

Laparoscopic splenectomy has been demonstrated to be technically feasible and safe for the treatment of immune thrombocytopenic purpura (ITP), hereditary spherocytosis, and Hodgkin's disease.

PATIENTS AND METHODS

The study comprised 76 consecutive patients with chronic ITP who were admitted to our hospital from 1968 to 1997 and underwent splenectomy; 35 patients underwent a laparoscopic splenectomy, and 41 had open surgery.

RESULTS

Laparoscopic splenectomy involved minimal incision, and a significantly lower frequency of analgesia was required for postoperative abdominal pain (1.4 versus 3.3); postoperative hospital stay was shorter (9.6 versus 20.1 days, P <0.05). Operative time was significantly longer for the laparoscopic surgery (204.5 versus 99.8 minutes, P <0.01), but blood loss was less (154.4 versus 511.7 g, P <0.01). During the present study (range 3.8 to 80 months), accumulative nonrecurrence rate was 67.9% in 5 years after surgery, which is similar to that of the previous open splenectomy.

CONCLUSIONS

Laparoscopic splenectomy can become an alternative therapeutic modality in the treatment of ITP.