Clinical Impact of Conversion Surgery After Induction Therapy for Esophageal Cancer with Synchronous Distant Metastasis: A Multi-institutional Retrospective Study

BACKGROUND

The standard treatment for advanced esophageal cancer with synchronous distant metastasis is systemic chemotherapy or immunotherapy. Conversion surgery is not established for esophageal cancer with synchronous distant metastasis. This study aimed to investigate the clinical impact of conversion surgery for esophageal cancer with synchronous distant metastasis after induction therapy.

METHODS

This multi-institutional retrospective study enrolled 66 patients with advanced esophageal cancer, including synchronous distant metastasis, who underwent induction chemotherapy or chemoradiotherapy followed by conversion surgery between 2005 and 2021. Short- and long-term outcomes were investigated.

RESULTS

Distant lymph node (LN) metastasis occurred in 51 patients (77%). Distant organ metastasis occurred in 15 (23%) patients. There were 41 patients with metastatic para-aortic LNs, and 10 patients with other metastatic LNs. Organs with distant metastasis included the lung in seven patients, liver in seven patients, and liver and lung in one patient. For 61 patients (92%), R0 resection was achieved. The postoperative complication rate was 47%. The in-hospital mortality rate was 1%, and the 3- and 5-year overall survival (OS) rates for all the patients were 32.4% and 24.4%, respectively. The OS rates were similar between the patients with distant LN metastasis and the patients with distant organ metastasis (3-year OS: 34.9% vs. 26.7%; P = 0.435). Multivariate analysis showed that pathologic nodal status is independently associated with a poor prognosis (hazard ratio, 2.43; P = 0.005).

CONCLUSIONS

Conversion surgery after chemotherapy or chemoradiotherapy for esophageal cancer with synchronous distant metastasis is feasible and promising. It might be effective for improving the long-term prognosis for patients with controlled nodal status.

Indications for neoadjuvant chemotherapy in older patients undergoing esophagectomy for esophageal cancer

PURPOSE

To investigate the indications for neoadjuvant chemotherapy (NAC) in esophageal cancer patients aged 75 years or older.

METHODS

We analyzed data, retrospectively, from 155 patients over 75 years old, who underwent esophagectomy for esophageal cancer between 2010 and 2020. Forty-one patients underwent upfront surgery (US group) and 114 were treated with NAC followed by surgery (NAC group). We compared the patient backgrounds and perioperative outcomes including prognosis, between the two groups.

RESULTS

The NAC group patients were significantly younger and had significantly more advanced clinical stage disease than the US group patients. The incidence of postoperative complications was similar in the two groups. Patients with a good pathological response to NAC had a significantly better prognosis than those with a poor response and those in the US group. Among patients with a performance status (PS) of 0, the 5-year OS rate was 56.5% in the NAC group and 38.1% in the US group (HR = 0.63, 95% CI 0.35-1.12). Among those with a PS of 1-2, the 5-year OS rates were 28.1% and 57.1%, respectively (HR = 1.69, 95% CI 0.99-2.89; P = 0.037 for interaction).

CONCLUSIONS

NAC did not improve the postoperative prognosis of older esophageal cancer patients with a PS of 1 or higher.

Association between fibrosis around the tumor and postoperative infectious complication in patients with esophageal cancer who underwent preoperative therapy

BACKGROUND

Multidisciplinary treatment combining chemotherapy, chemo radiation therapy (CRT), and surgery has been utilized for advanced esophageal cancer. However, preoperative treatment could cause postoperative inflammation and complications. We hypothesized that fibrosis surrounding tumor tissue caused by preoperative treatment could induce postoperative systemic inflammation and influence postoperative complications.

METHODS

Surgical specimens from patients with thoracic esophageal cancer who underwent preoperative CRT (38 cases) or chemotherapy (77 cases) and those who received no preoperative treatment (49 cases) were evaluated to measure the fibrotic area adjacent to the tumor (10 mm from the tumor edge) by applying Azan staining. Pleural effusion and peripheral blood serum interleukin-6 levels were analyzed to evaluate local and systemic postoperative inflammation in 37 patients.

RESULTS

The fibrotic areas around the tumors were significantly larger in patients who underwent preoperative CRT than in patients who underwent chemotherapy (p < 0.001) or who had received no preoperative therapy (p < 0.001). Infectious complications were higher in patients who underwent preoperative CRT than chemotherapy (p = 0.047) or surgery alone (p < 0.001). The patients with larger fibrotic areas had more infectious complications (p = 0.028). Multivariate analysis showed that both a large fibrotic area and preoperative CRT were correlated with infectious complications, but not significantly. Pleural effusion interleukin-6 was significantly higher in patients who underwent preoperative CRT than in patients who received no preoperative therapy (p = 0.013).

CONCLUSIONS

A large fibrotic peritumoral esophageal tissue area after preoperative treatment could cause postoperative inflammatory response and infectious complications.

Oral frailty is a risk factor for body weight loss after gastrectomy: a single-center, retrospective study

BACKGROUND

Body weight loss (BWL) is a serious complication of gastrectomy in patients with gastric cancer (GC). Nutritional intervention alone is inadequate for preventing BWL, and a new approach is needed. Oral frailty among older adults has recently attracted attention. This study aimed to investigate masticatory ability and BWL after gastrectomy.

METHODS

This was a single-center, retrospective study. Functional tooth units (FTU) were used to measure masticatory ability. Patients with FTU < 4 were defined as low FTU group and FTU ≥ 4 as high FTU group. The BWL was compared between the two groups.

RESULTS

Sixty patients who underwent distal gastrectomy for GC from March 2022 to January 2023 were enrolled in this study. The median FTU was 3 (range 0-12). The low-FTU group (FTU < 4) included 29 patients, while the high-FTU group (FTU ≥ 4) included 31 patients. The %BWL in the low FTU group was significantly higher than that in the high-FTU group at 1 and 3 months (p = 0.003 and p = 0.017, respectively). The risk factors associated with a %BWL > 5 at 1 and 3 months after gastrectomy were analyzed using logistic regression analysis. Only FTU < 4 was an independent risk factor after gastrectomy for GC in univariate and multivariate analyses (p = 0.028 and p = 0.006, respectively).

CONCLUSIONS

Low FTU in patients with preoperative GC was a risk factor for %BWL 1 and 3 months postoperatively. Appropriate oral interventions may be useful in improving the postoperative nutritional status after gastrectomy.

A case of Barrett's esophageal adenocarcinoma and severe scoliosis with successful salvage esophagectomy after definitive chemoradiotherapy

BACKGROUND

Severe scoliosis can cause reflux esophagitis, and is a risk factor for Barrett's adenocarcinoma of the esophagus. Severe scoliosis is associated with respiratory dysfunction, impaired operative tolerance, and anatomical difficulty in surgical manipulation, and is, therefore, considered a high surgical risk. In this report, we describe the case of a young patient with Barrett's esophageal adenocarcinoma with severe scoliosis who underwent salvage surgery after radical chemoradiotherapy.

CASE PRESENTATION

The patient was a 39-year-old male. Although he had severe scoliosis and paraplegia of both lower limbs since childhood, he was independent in activities of daily living. His previous doctor, who diagnosed the esophageal cancer, determined that surgery was not indicated due to the coexistence of severe scoliosis, so he underwent chemoradiotherapy with curative intent. After chemoradiotherapy, the patient was referred to our hospital for a second opinion because of a tumor remnant. After various additional examinations, thoracoscopic and laparoscopic subtotal esophagectomy for esophageal cancer was performed, along with ante-thoracic route reconstruction using a narrow gastric tube. Although the patient had symptoms associated with postoperative reflux, he recovered well overall and was discharged home about 4 weeks after surgery.

CONCLUSIONS

We report the case of an esophageal cancer patient with severe scoliosis at high surgical risk who underwent successful minimally invasive esophagectomy.

Impact of Relative Dose Intensity of Docetaxel, Cisplatin, and 5-Fluorouracil Neoadjuvant Chemotherapy on Survival of Esophageal Squamous Cell Cancer Patients

INTRODUCTION

This study aimed to clarify the impact of the average relative dose intensity (RDI) of neoadjuvant chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF-NAC) for resectable locally advanced esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

To identify the optimal RDI, recurrence-free survival (RFS) and cumulative incidence function (CIF) for recurrence were calculated in low and high RDI groups with any cut-off points. The optimal RDI was defined as the highest RDI administered with a significant increase in either RFS or CIF. The clinicopathological characteristics of the two groups divided by optimal RDI were investigated. The preoperative prognostic factors associated with RFS were confirmed by multivariable Cox proportional hazards model.

RESULTS

Among the 150 eligible patients treated with DCF-NAC from 2010 to 2020, 3-year RFS and CIF were 56.3% and 37.8% in 90 patients in the less than 80% RDI group (<80% RDI) and 73.3% and 26.7% in 60 patients in the more than or equal to 80% RDI group (≥80% RDI), respectively. The optimal cut-off RDI was identified as 80%. The <80% RDI group included older individuals, a lower value of creatinine clearance, a higher Charlson Comorbidity Index, reduced RDI at first course, and grade 1-0 in the histopathological tumor response than the ≥80% RDI group. R0 resection and postoperative complication rates were equal in both groups. Cox proportional hazards model identified the response rate and RDI as predictors of RFS.

CONCLUSION

An average RDI of more than or equal to 80% improved prognosis in patients receiving DCF-NAC for ESCC.

[A Case of Sheath-Like Obstruction of the Entire Catheter in a Short Period of Time after Placement of an Intraperitoneal Access Port]

Intraperitoneal chemotherapy, in which an anticancer drug is administered directly into the abdominal cavity through an intraperitoneal access port(IP port), is one of the treatment options for advanced gastric cancer with peritoneal metastasis. Herein, we report a case of sheath-like obstruction of the entire catheter of the IP port due to tissue reaction within a short period of time after IP port implantation. The case was a 35-year-old woman with advanced type 4 gastric cancer with peritoneal dissemination. The IP port was placed and intravenous and intraperitoneal chemotherapy using S-1 plus paclitaxel was started. However, in the middle of the second course, the entire catheter was covered with a fibrous capsule and a sheath-like obstruction occurred, so the IP port was removed and a new IP port was reinserted. One of the IP port troubles is obstruction, but such short-term and special obstruction is rare, and the cause is considered to be a foreign body reaction of the catheter.

A pilot randomized controlled trial comparing THUNDERBEAT to the Maryland LigaSure energy device in laparoscopic left colon surgery

BACKGROUND

The THUNDERBEAT is a multi-functional energy device which delivers both ultrasonic and bipolar energy, but there are no randomized trials which can provide more rigorous evaluation of the clinical performance of THUNDERBEAT compared to other energy-based devices in colorectal surgery. The aim of this study was to compare the clinical performance of THUNDERBEAT energy device to Maryland LigaSure in patients undergoing left laparoscopic colectomy.

METHODS

Prospective randomized trial with two groups: Group 1 THUNDERBEAT and Group 2 LigaSure in a single university hospital. 60 Subjects, male and female, of age 18 years and above undergoing left colectomy for cancer or diverticulitis were included. The primary outcome was dissection time to specimen removal (DTSR) measured in minutes from the start of colon mobilization to specimen removal from the abdominal cavity. Versatility (composite of five variables) was measured by a score system from 1 to 5 (1 being worst and 5 the best), and adjusted/weighted by coefficient of importance with distribution of the importance as follow: hemostasis 0.275, sealing 0.275, cutting 0.2, dissection 0.15, and tissue manipulation 0.1. Other variables were: dryness of surgical field, intraoperative and postoperative complications, and mortality. Follow-up time was 30 days.

RESULTS

60 Patients completed surgery, 31 in Group 1 and 29 in Group 2. There was no difference in the DTSR between the groups, 91 min vs. 77 min (p = 0.214). THUNDERBEAT showed significantly higher score in dissecting and tissue manipulation in segment 3 (omental dissection), and in overall versatility score (p = 0.007) as well as versatility score in Segment 2 (retroperitoneal dissection p = 0.040) and Segment 3 (p = 0.040). No other differences were noted between the groups.

CONCLUSIONS

Both energy devices can be employed effectively and safely in dividing soft tissue and sealing mesenteric blood vessels during laparoscopic left colon surgery, with THUNDERBEAT demonstrating some advantages over LigaSure during omental dissection and tissue manipulation.

CLINICALTRIAL

gov # NCT02628093.

Efficacy of conversion surgery after a single intraperitoneal administration of paclitaxel and systemic chemotherapy for gastric cancer with peritoneal metastasis

PURPOSE

The prognosis of gastric cancer patients with peritoneal metastasis (PM) remains dismal with standard systemic chemotherapy. Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has local effects on intra-abdominal cancer cells. According to this phenomenon, we have developed regimens combining single i.p. PTX administration with systemic chemotherapy. This treatment strategy is very promising; however, the effect of "conversion surgery" in patients responding to this chemotherapy is unclear. Therefore, we performed a retrospective study to evaluate the safety and efficacy of conversion surgery for gastric cancer patients with PM.

METHODS

We enrolled 52 gastric cancer patients with PM who were treated with single i.p. PTX plus systemic chemotherapy between 2005 and 2015. Conversion surgery was performed where PM was eliminated by combination chemotherapy.

RESULTS

Among 52 gastric cancer patients, the disappearance of PM was confirmed in 33 patients (63.5%). Gastrectomy with D2 lymph node dissection was performed in all these patients. Histological response of grade ≥ 1b was achieved in 13 patients (39%). Clavien-Dindo grade II postoperative complications occurred in three patients (9%). There were no treatment-related deaths. The median survival time and 1-, 3-, and 5-year overall survival rates of the 33 patients who underwent conversion surgery were 30.7 months and 78.8%, 36.3%, and 24.2%, respectively, and those of the 19 patients who did not undergo surgery were 12.5 months and 52.6%, 5.2%, and 0%, respectively.

CONCLUSION

Conversion surgery is safe and may prolong survival for gastric cancer patients with PM who have responded to single i.p. PTX plus systemic chemotherapy.

A novel method of esophagogastrostomy by overlap anastomosis with placement of the remnant stomach into the lower mediastinum after laparoscopic proximal gastrectomy

INTRODUCTION

Control of postoperative gastroesophageal reflux (GER) is a critical consideration for patients who undergo proximal gastrectomy. This report describes a new and simple reconstruction method by esophagogastrostomy with placement of the remnant stomach into the lower mediastinum (EG-PRIME). This approach not only suppresses postoperative GER, but it can also be easily performed by total laparoscopy. Detailed herein are the methods for EG-PRIME and the results for three patients with cancer of the upper gastric body.

MATERIALS AND SURGICAL TECHNIQUE

At the start of the EG-PRIME surgical procedure, a pseudo-fornix and lozenge-shaped gastric conduit were made by cutting the stomach diagonally. Next, the pseudo-fornix was inserted into the esophageal hiatus to form a new angle of His. Then overlap anastomosis was performed and the entry site was closed longitudinally. The outcomes assessed were operative time, intraoperative blood loss, postoperative complications and GER according to 24-hour pH monitoring.

DISCUSSION

The operative times were 339, 288 and 236 minutes; in two patients, intraoperative blood loss was 260 and 343 mL, and in the third, blood loss was minimal. No postoperative complications were observed in any of the three patients. The degree of the GER resulting in fraction time pH<4 was 9.0%, 0.3%, and 2.9%, respectively. No esophagitis by upper gastrointestinal endoscopy was observed in any patient. This EG-PRIME method was technically feasible for reconstruction after proximal gastrectomy by total laparoscopy. This approach may be as simple and useful as esophagogastrostomy for preventing postoperative GER, but more experience with this method is required.

A comparative study of the lengths of different reconstruction routes used after thoracic esophagectomy

BACKGROUND

A challenge in esophageal reconstruction after esophagectomy is that the distance from the neck to the abdomen must be replaced with a long segment obtained from the gastrointestinal tract. The success or failure of the reconstruction depends on the blood flow to the reconstructed organ and the tension on the anastomotic site, both of which depend on the reconstruction distance. There are three possible esophageal reconstruction routes: posterior mediastinal, retrosternal, and subcutaneous. However, there is still no consensus as to which route is the shortest.

METHODS

The length of each reconstruction route was retrospectively compared using measurements obtained during surgery, where the strategy was to pull up the gastric conduit through the shortest route. The proximal reference point was defined as the left inferior border of the cricoid cartilage and the distal reference point was defined as the superior border of the duodenum arising from the head of the pancreas.

RESULTS

This study involved 112 Japanese patients with esophageal cancer (102 men, 10 women). The mean distances of the posterior mediastinal, retrosternal, and subcutaneous routes were 34.7 ± 2.37 cm, 32.4 ± 2.24 cm, and 36.3 ± 2.27 cm, respectively. The retrosternal route was significantly shorter than the other two routes (both p < 0.0001) and shorter by 2.31 cm on average than the posterior mediastinal route. The retrosternal route was longer than the posterior mediastinal route in only 5 patients, with a difference of less than 1 cm.

CONCLUSION

The retrosternal route was the shortest for esophageal reconstruction in living Japanese patients.

Comparison of Aggressive Planned Salvage Surgery Versus Neoadjuvant Chemoradiotherapy Plus Surgery for Borderline Resectable T4 Squamous Cell Carcinoma

INTRODUCTION

We compare planned salvage surgery after definitive chemoradiotherapy (SALV) versus neoadjuvant chemoradiotherapy plus surgery (NCRS) for borderline resectable T4 esophageal squamous cell carcinoma.

PATIENTS AND METHODS

A total of 37 patients underwent planned SALV, and 20 underwent NCRS from 2004 to 2017. The short-term outcome measures were the R0 resection rate, complications, and treatment-related mortality. The long-term outcome measures were the 5-year overall survival rate and causes of death.

RESULTS

R0 resection rate was similar between the SALV and NCRS groups (81% versus 85%). The incidence of postoperative pneumonia (35% versus 18%) and treatment-related mortality rate (9% versus 0%) tended to be higher in the SALV. ypT grade 2-3 (65% versus 30%, p = 0.012) and Clavien-Dindo grade ≥ IIIb complications (32% versus 0%, p = 0.008) were significantly more frequent in the SALV group. The groups had similar 5-year overall survival (26% versus 27%). The causes of death in the SALV and NCRS groups were primary esophageal cancer in 35% and 55% of patients, respectively, and pulmonary-related mortality in 24% and 5%, respectively. Multivariable Cox regression analysis revealed the following significant poor prognostic factors: stable disease as the clinical response, preoperative body mass index (BMI) of < 18.5 kg/m², ypN stage 1-3, and R1-2 resection.

CONCLUSIONS

SALV was associated with a higher incidence of late pulmonary-related mortality but had a stronger antitumor effect than NCRS. Consequently, the survival rate was similar between the groups. Surgery is recommended for patients with a partial response and preoperative BMI of ≥ 18.5 kg/m².

Intraluminal gas escape from biopsy valves and endoscopic devices during endoscopy: caution advised during the COVID-19 era

Background and study aims  The risk of aerosolization of body fluids during endoscopic procedures should be evaluated during the COVID-19 era, as this may contribute to serious disease transmission. Here, we aimed to investigate if use of endoscopic tools during flexible endoscopy may permit gas leakage from the scope or tools. Material and methods  Using a fresh 35-cm porcine rectal segment, a colonoscope tip, and manometer were placed intraluminally at opposite ends of the segment. The colonoscope handle, including the biopsy valve, was submerged in a water bath. Sequentially, various endoscopic devices (forceps, clips, snares, endoscopic submucosal dissection (ESD) knives) were inserted into the biopsy valve, simultaneously submerging the device handle in a water bath. The bowel was slowly inflated up to 74.7 mmHg (40 inH ₂ O) and presence of gas leakage, leak pressure, and gas leakage volume were measured. Results  Gas leakage was observed from the biopsy valve upon insertion and removal of all endoscopic device tips with jaws, even at 0 mmHg (60/60 trials). The insertion angle of the tool affected extent of gas leakage. In addition, gas leakage was observed from the device handles (8 of 10 devices) with continuous gas leakage at low pressures, especially two snares at 0 mmHg, and an injectable ESD knife at 0.7 ± 0.8 mmHg). Conclusions  Gas leakage from the biopsy valve and device handles commonly occur during endoscopic procedures. We recommend protective measures be considered during use of any tools during endoscopy.

The use of 3D laparoscopic imaging systems in surgery: EAES consensus development conference 2018

BACKGROUND

The use of 3D laparoscopic systems is expanding. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

Systematic reviews of the PubMed and Embase libraries were performed to identify evidence on potential benefits of 3D on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by an international surgical and engineering expert panel which were presented and voted at the EAES annual congress, London, May 2018.

RESULTS

9967 abstracts were screened with 138 articles included. 18 statements and two recommendations were generated and approved. 3D significantly shortened operative time (mean difference 11 min (8% [95% CI 20.29-1.72], I² 96%)). A significant reduction in complications was observed when 3D systems were used (RR 0.75, [95 CI% 0.60-0.94], I² 0%) particularly for cases involving laparoscopic suturing (RR 0.57 [95% CI 0.35-0.90], I² 0%). In 69 box trainer or simulator studies, 64% concluded trainees were significant faster and 62% performed fewer errors when using 3D.

CONCLUSION

We recommend the use of 3D vision in laparoscopy to reduce the operative time (grade of recommendation: low). Future robust clinical research is required to specifically investigate the potential benefit of 3D laparoscopy system on complication rates (grade of recommendation: high).

Successful Endoscopic Treatment of Post-esophagectomy Refractory Reflux Using OverStitch: The First Clinical Case

Aims:

The reflux of duodeno-gastric contents into the remnant esophagus (gastric tube-esophageal reflux: GTER) is a significant issues in long-term esophageal cancer survivors after radical esophagectomy. We attempted endoscopic valve (funnel) creation for prevention for GTER using OverStitch endoscopic suturing system.

Methods:

The OverStitch was mounted onto a standard double-channel endoscope. Under general anesthesia, the funnel creation was attempted by placing semi-full thickness sutures on the gastric wall, at 3 cm distal to the primary esophago-gastric anastomosis. The postoperative outcomes were also evaluated.

Results:

In total, 4 sutures were needed and the operating time was 62 minutes without complication. The endoscopic and swallowing studies, as well as pH profile, were all improved postoperatively. The patient’s quality of life was dramatically improved with complete disappearance of night-time reflux in spine position.

Conclusions:

Endoscopic antireflux funnel creation was feasible and safe. This procedure may become a useful treatment for patients with severe GTER after esophagectomy.

Nonlinear Analysis of Visual Evoked Potentials Elicited by Color Stimulation

The relationship between chromatically modulated stimuli and visual evoked potentials (VEPs) was considered. VEPs of normal subjects elicited by chromatically modulated stimuli were measured under several color adaptations, and their binary kernels were estimated. Up to the second-order, binary kernels obtained from VEPs were so characteristic that the VEP-chromatic modulation system showed second-order nonlinearity. First-order binary kernels depended on the color of the stimulus and adaptation, whereas second-order kernels showed almost no difference. This result indicates that the waveforms of first-order binary kernels reflect perceived color (hue). This supports the suggestion that kernels of VEPs include color responses, and could be used as a probe with which to examine the color visual system.

Somatic mutations in plasma cell-free DNA are diagnostic markers for esophageal squamous cell carcinoma recurrence

Objectives

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies owing to the high frequency of tumor recurrence. The identification of markers for early ESCC diagnosis and prediction of recurrence is expected to improve the long-term prognosis. Therefore, we searched for associations between tumor recurrence and cell-free DNA (cfDNA) mutations in blood plasma, which contains genetic markers for various cancer types.

Experimental Design

Genomic DNA from tumors and cfDNA from plasma were obtained from 13 patients undergoing treatment for newly diagnosed ESCC. Next-generation sequencing of cfDNA in plasma was performed to identify mutations in 53 cancer-related genes, in which recurrent mutations were previously detected in ESCC. cfDNA mutational profiles were compared before and after tumor resection in four patients. Furthermore, somatic mutations in serial plasma samples were monitored after treatment in four patients.

Results

We identified multiple concordant somatic mutations in cfDNA and primary tumor samples from 10 patients (83.3%) and in cfDNA and metastatic tumor samples from one patient (100%). Furthermore, the allele frequency of the concordant mutations in cfDNA changed concomitantly with tumor burden and increased approximately 6 months earlier than the detection of tumor recurrences by imaging tests in two patients. Conventional biomarkers, such as SCC and p53-Ab, did not reflect tumor recurrences.

Conclusions

The present multigene panel, which enabled the diagnosis of tumor recurrence with greater accuracy than did using standard tumor markers or imaging methods, is expected to greatly facilitate standard, postoperative follow-up monitoring in ESCC.

Relationship between the Binary Kernels of Visually Evoked Potentials and the Visual Responses on the Magnocellular and Parvocellular Pathways

Objectives : To investigate the nonlinear characteristics of visual evoked potentials (VEPs), and their correlation with the visual responses on parvocellular and magnocellular pathways. First and second-order kernels of the VEPs elicited by several checkerboard patterns were estimated, and their relations to the visual pathway responses were investigated.

Methods : VEPs elicited by checkerboard pattern (0.5, 1.0, 2.0 and 4.0 c/d) alternating based on pseudorandom binary sequence were measured, and thei binary kernels were calculated. First and second-order binary kernels were compared with amplitudes o the steady-state VEPs (S-VEPs) to pattern reversal stimulation with a constant temporal frequency (4, 8, 12, 16, and 32 Hz).

Results : Positive peak latencies at 150 ms (P150) of second-order first and second slices were correlated with S-VEP amplitude for higher temporal frequencies, indicating that the first and second slices reflect the response of the magnocellular. However, for second and third slices, their amplitudes were partially correlated with 4-16 Hz S-VEP, and this indicated that the second slice contains both magno- and parvocellular pathway responses. P150 latencies of third slices were correlated with S-VEP for lower temporal frequencies, indicating that third slice reflects the response of the parvocellular pathway.

Conclusions : The lower slices of second-order binary kernels reflect the response of the magnocellular pathway and the higher slices reflect those on the parvocellular pathway in the human visual system of VEPs.

MLH1 expression predicts the response to preoperative therapy and is associated with PD-L1 expression in esophageal cancer

Programmed death-ligand 1 (PD-1/PD-L1) inhibition therapy demonstrates potential as a future treatment for esophageal cancer. Mismatch repair status and tumor PD-L1 expression are the candidate predictive biomarkers for response to this therapy. In colorectal cancer, mismatch repair-deficient tumors are associated with improved survival, although they are not sensitive to 5-fluorouracil-based chemotherapy. The purpose of the present study was to investigate the association between MutL homolog 1 (MLH1) expression and prognosis, response to therapy and PD-L1 expression in esophageal cancer. Immunohistochemistry was used to evaluate MLH1 and PD-L1 expression in 251 resected specimens. Of the specimens, 30.3% exhibited low MLH1 expression and 15.5% exhibited high PD-L1 expression. The 5-year overall survival rates for the high MLH1 expression group and the low MLH1 expression group were 51.3 and 55.6%, respectively (P=0.5260). The responder ratio was 45.7% in the high MLH1 expression group and 15.4% in the low MLH1 expression group (P<0.0001). The frequency of high PD-L1 expression was 11.4% in the high MLH1 expression group (P=0.0064) and 25.0% in the low MLH1 expression group. MLH1 expression may be a predictive factor for the response to preoperative therapy in esophageal cancer, and esophageal cancer with low MLH1 expression may have a mechanism that assists in promoting tumor PD-L1 expression.

Prevention of transient liver damage after laparoscopic gastrectomy via modification of the liver retraction technique using the Nathanson liver retractor

INTRODUCTION

Although laparoscopic radical gastrectomy has several advantages over conventional surgery, postoperative liver dysfunction is an unwanted complication. The major cause is considered to be use of mechanical liver retraction. To prevent liver damage after laparoscopic gastrectomy, we modified the liver retraction method: the retractor was used only after lymph node dissection along the greater curvature had been completed, and it was released before reconstruction and intermittent repositioning to avoid discoloration of the liver parenchyma. This study sought to determine whether postoperative liver dysfunction could be prevented by making these simple modifications.

METHODS

In this retrospective study involving 114 laparoscopic gastrectomy patients, postoperative serum aspartate aminotransferase, alanine aminotransferase (ALT), and total bilirubin levels were compared between laparoscopic gastrectomy patients who had undergone the modified procedure and those who had not. Discoloration of the liver was classified into three groups just before the retractor was released at the end of surgery.

RESULTS

Aspartate aminotransferase and ALT levels on postoperative days 1 and 2 and the proportion of patients with elevated aspartate aminotransferase or ALT levels on postoperative day 1 were significantly lower after the modifications. ALT level on postoperative day 1 was significantly higher in the subgroup with broad liver discoloration.

CONCLUSIONS

Reducing the duration of liver retraction and moving the position of the retractor or releasing it intermittently before discoloration of the liver parenchyma may be effective for preventing postoperative liver damage.

Laparoscopic plug removal for femoral nerve colic pain after mesh & plug hernioplasty

Background

Inguinal hernias account for 75 % of abdominal wall hernias, with a lifetime risk of 27 % in men and 3 % in women. Major complications are recurrence, chronic pain, and surgical site infection, but their frequency is low. Few studies have reported a calcified mesh causing neuropathy by chronic compression of the femoral nerve after mesh & plug inguinal hernia repair. This is the first report of laparoscopic plug removal for femoral colic due to femoral nerve irritation cause by a calcified plug after mesh & plug inguinal hernia repair.

Case presentation

In July 2013, a 53-year-old man presented to our hospital with a chief complaint of colic pain in the left lower limb while walking. The patient had undergone left inguinal hernia repair about 10 years earlier and reported no chronic pain after the operation. Physical examination revealed a colic pain exacerbated by left thigh movement, especially during flexion, but the patient was pain-free at rest and had no sensory loss. Axial computed tomography and magnetic resonance imaging showed that the inward-projecting plug was extremely close to the femoral nerve. Because of the radicular symptoms and the absence of orthopedic and urological disease, we strongly suspected that the neuralgia was associated with the previous hernia operation and advised exploratory laparotomy, which revealed the plug bulging inward into the abdominal cavity. Moreover, the tip of the plug was firmly calcified and compressing the femoral nerve, which lay just beneath the plug, especially during hip flexion. We explanted the plug and his pain resolved after the operation. The patient remains pain free after 20 months of follow up.

Conclusion

In this study, laparoscopic hernioplasty proved useful for plug removal because laparoscopic instruments can easily grasp perilesional tissue, and laparoscopic approach has the benefit of isolating the plug for removal while preserving the onlay patch, and helpful for restoring peritoneal defects. Laparoscopic plug removal effectively resolved colic pain in the left thigh due to compression of the femoral nerve by a calcified plug.

Bronchial bleeding caused by recurrent pneumonia after radical esophagectomy for esophageal cancer

We herein report a case of bronchial bleeding after radical esophagectomy that was treated with lobectomy. A 65-year-old male who underwent subtotal esophagectomy with three-field lymph node dissection for esophageal carcinoma was referred to our hospital because of sudden hemoptysis. After the esophagectomy, bilateral vocal cord paralysis was observed, and the patient suffered from repeated episodes of aspiration pneumonia. Bronchoscopy revealed hemosputum in the right middle lobe bronchus, and contrast-enhanced computed tomography showed tortuous arteries arising from the right inferior phrenic artery and left subclavian artery toward the right middle lobe bronchus. Although bronchial arterial embolization was performed twice to control the recurrent hemoptysis, the procedures were unsuccessful. Right middle lobectomy was therefore performed via video-assisted thoracic surgery. Engorged bronchial arterys with medial hypertrophy and overgrowth of the small branches were noted near the bronchus in the resected specimen. The patient recovered uneventfully and was discharged on postoperative day 14.

Benign esophageal stricture after thermal injury treated with esophagectomy and ileocolon interposition

Thermal injuries of the esophagus are rare causes of benign esophageal stricture, and all published cases were successfully treated with conservative management. A 28-year-old Japanese man with a thermal esophageal injury caused by drinking a cup of hot coffee six months earlier was referred to our hospital. The hot coffee was consumed in a single gulp at a party. Although the patient had been treated conservatively at another hospital, his symptoms of dysphagia gradually worsened after discharge. An upper gastrointestinal endoscopy and computed tomography revealed a pin-hole like area of stricture located 19 cm distally from the incisors to the esophagogastric junction, as well as circumferential stenosis with notable wall thickness at the same site. The patient underwent a thoracoscopic esophageal resection with reconstruction using ileocolon interposition. The pathological findings revealed wall thickening along the entire length of the esophagus, with massive fibrosis extending to the muscularis propria and adventitia at almost all levels. Treatment with balloon dilation for long areas of stricture is generally difficult, and stent placement in patients with benign esophageal stricture, particularly young patients, is not yet widely accepted due to the incidence of late adverse events. Considering the curability and quality-of-life associated with a long expected prognosis, we determined that surgery was the best treatment option for this young patient. In this case, we decided to perform an esophagectomy and reconstruction with ileocolon interposition in order to preserve the reservoir function of the stomach and to avoid any problems related to the reflux of gastric contents. In conclusion, resection of the esophagus is a treatment option in patients with benign esophageal injury, especially in cases involving young patients with refractory esophageal stricture. In addition, ileocolon interposition may help to improve the quality-of-life of patients.

Population fluctuations of light-attracted chrysomelid beetles in relation to supra-annual environmental changes in a Bornean rainforest

In Southeast Asian tropical rainforests, two events, severe droughts associated with the El Niño-Southern Oscillation and general flowering, a type of community-wide mass flowering, occur at irregular, supra-annual intervals. The relationship between these two supra-annual events and patterns of insect population fluctuations has yet to be clearly elucidated. Leaf beetles (Chrysomelidae) are major herbivores and flower-visitors of canopy trees, affecting their growth and reproduction and, in turn, affected by tree phenology; but their population fluctuations in the Southeast Asian tropics have not been extensively investigated. We examined population fluctuation patterns of the 34 most dominant chrysomelid species in relation to the two supra-annual events by conducting monthly light-trapping over seven years in a lowland dipterocarp forest in Borneo. Our results showed large community variation in population fluctuation patterns and a supra-annual (between-year) variation in abundance for most of the dominant chrysomelids that was significantly larger than the annual (within-year) variation. Specifically, in response to a severe drought in 1998, chrysomelid species exhibited different population responses. These results show that population fluctuations of individual species, rather than the entire assemblage, must be analyzed to determine the effects of changes in environmental conditions on the structure of insect assemblages in the tropics, especially in regions where supra-annual environmental changes are relatively more important than seasonal changes.

Evaluation of an eye gaze point detection method using VEP elicited by multi-pseudorandom stimulation for brain computer interface

A method for detecting eye gaze point using visual evoked potentials (VEPs) elicited by pseudorandom stimuli was examined. Prototype system which would be a practical brain computer interface is established and evaluated. Four luminance modulated red characters based on four different pseudorandom binary sequences (PRBS) of 5.11 seconds were simultaneously presented on a monitor, and the cross correlation functions (kernels) of VEPs and each PRBS were calculated and used to determine the subject's gazed target. In an experiment with subjects with normal vision, their gazed target was obtained from VEPs within 7 seconds, and the mean error rate of detection was 22%. Results indicated that this technique could be useful as a practical brain computer interface system.

Measurement of color discrimination threshold using visually evoked potential and its correlation with psychophysical measure

Purpose was to determine whether our developed electrophysiological technique (Momose and Saito, 2002) using visually evoked potential (VEP) is effective for determining the color discrimination threshold in human. Both VEP and psychophysical color matching measurement were applied to three normal volunteers, and their correlation and sensitivity were investigated. Colors on the MacAdam ellipse were selected for stimulus. Threshold determined by VEP was well correlated with psychophysical measure (r = 0.88 and 0.75 in two subjects), and was about 24 times higher than psychophysical ones. VEP measurement was done within much shorter time (30 min.) than psychophysical method (3 hours). VEP determined color discrimination threshold can be effective for the human color vision testing.

relationship between the binary kernels of visually evoked potentials and the visual responses on the magnocellular and parvocellular pathways

OBJECTIVES

To investigate the nonlinear characteristics of visual evoked potentials (VEPs), and their correlation with the visual responses on parvocellular and magnocellular pathways. First and second-order kernels of the VEPs elicited by several checkerboard patterns were estimated, and their relations to the visual pathway responses were investigated.

METHODS

VEPs elicited by checkerboard pattern (0.5, 1.0, 2.0 and 4.0 c/d) alternating based on pseudorandom binary sequence were measured, and their binary kernels were calculated. First and second-order binary kernels were compared with amplitudes of the steady-state VEPs (S-VEPs) to pattern reversal stimulation with a constant temporal frequency (4, 8, 12, 16, and 32 Hz).

RESULTS

Positive peak latencies at 150 ms (P150) of second-order first and second slices were correlated with S-VEP amplitude for higher temporal frequencies, indicating that the first and second slices reflect the response of the magnocellular. However, for second and third slices, their amplitudes were partially correlated with 4-16 Hz S-VEP, and this indicated that the second slice contains both magno- and parvocellular pathway responses. P150 latencies of third slices were correlated with S-VEP for lower temporal frequencies, indicating that third slice reflects the response of the parvocellular pathway.

CONCLUSIONS

The lower slices of second-order binary kernels reflect the response of the magnocellular pathway and the higher slices reflect those on the parvocellular pathway in the human visual system of VEPs.

Resource use of insect seed predators during general flowering and seeding events in a Bornean dipterocarp rain forest

Insect seed predators of 24 dipterocarp species (including the genera ot Dipterocarpus, Dryobalanops and Shorea) and five species belonging to the Moraceae, Myrtaceae, Celastraceae and Sapotaceae were investigated. In a tropical lowland dipterocarp forest in Sarawak, Malaysia, these trees produces seeds irregularly by intensely during general flowering and seeding events in 1996 and/or 1998. Dipterocarp seeds were preyed on by 51 insect species (11 families), which were roughly classified into three taxonomic groups: smaller moths (Trotricidae, Pyralidae, Crambidae, Immidae, Sesiidae, and Cosmopterigidae), scolytids (Scolydae) and weevils (Curdulionidae, Apionidae, Anthribidae, and Attelabidae). Although the host-specificity of invertebrate seed predators has been assumed to be high in tropical forests, it was found that the diet ranges of some insect predators were relatively wide and overlapped one another. Most seed predators that were collected in both study years changes their diets between general flowering and seeding events. The results of cluster analyses based on the number of adult of each predator species that emerged from 100 seeds of each tree species, suggested that the dominant species was not consistent, alternating between the two years.

Differential expression of VAMP2/synaptobrevin-2 after antidepressant and electroconvulsive treatment in rat frontal cortex

The biological basis for the therapeutic mechanisms of depression is still unknown. We have previously performed expressed-sequence tag (EST) analysis to identify some molecular machinery responsible for antidepressant effect. Then, we developed our original cDNA microarray, on which cDNA fragments identified as antidepressant-related genes/ESTs were spotted. In this study, with this microarray followed by Western blot analysis, we have demonstrated the induction of vesicle-associated membrane protein 2(VAMP2/synaptobrevin-2) in rat frontal cortex not only after chronic antidepressant treatment, but also after repeated electroconvulsive treatment. On the other hand, expression of SNAP-25 and syntaxin-1 was not changed by these treatments. These components make a soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor complex with VAMP2 and mediate the synaptic vesicle docking/fusion machinery. In conclusion, it is suggested that VAMP2/synaptobrevin-2 plays important roles in the antidepressant effects. Our results may contribute to a novel model for the therapeutic mechanism of depression and new molecular targets for the development of therapeutic agents.

Induction of kf-1 after repeated electroconvulsive treatment and chronic antidepressant treatment in rat frontal cortex and hippocampus

It has been proposed that signaling pathways involved in adaptive neural plasticity are long-term targets for the action of electroconvulsive treatment (ECT), which is widely used in the treatment of drug-resistant depression. We have previously performed EST analysis to identify some molecular machinery responsible for antidepressant effect. One of the cDNA fragments identified as antidepressant related genes/ESTs was identified as kf-1 which has a RING-H2 finger motif at the carboxy-terminus. In the present study, we have demonstrated the induction of kf-1 in rat frontal cortex and hippocampus not only after chronic antidepressant treatment, but also after a single and repeated ECT. RING finger proteins are proposed to play some important roles in the ubiquitin-proteasome system. In conclusion, the current investigation has identified kf-1 as a novel molecular target for antidepressants and ECT.

Application of visual evoked potentials for preoperative estimation of visual function in eyes with dense cataract

PURPOSE

To determine whether the temporal frequency characteristics of the visual system as determined by visually evoked potentials (VEP) can be used for a preoperative estimation of the visual function in eyes with cataracts.

METHODS

Light stimuli driven by a pseudorandom binary sequence (PRBS) of 40950 ms duration were presented and EEG recordings were made from 13 control and 20 patients with cataracts preoperatively and 1 week after cataract operation. The first kernel of the PRBS-VEP was obtained as the first-order cross-correlation function between PRBS and PRBS-VEP. The Fourier transform of this function was used as the temporal frequency characteristic (TFC).

RESULTS

The mean +/- standard deviation of the latency and amplitude of the VEP in normal controls were 110.8+/-4.3 ms and 2.01+/-0.67 microV, respectively. A high correlation (r>0.7) between the pre-and postoperative VEP waveform was obtained in 13 eyes (65%), and 14 eyes (70%) in the VEP-TFC curves. The sensitivity of the examination was 73%, 27%, and 91% for the latency, amplitude and TFC of the VEP, respectively. The specificity of the examination was 67%, 100%, and 89% for the same measures. Eleven of 12 eyes with abnormal TFC preoperatively showed retinal or optic nerve lesions postoperatively. False-negative results were seen in cases with delayed corneal edema.

CONCLUSION

Postoperative visual function of patients with cataracts can be predicted by preoperative measurement of the TFC obtained by PRBS-VEP.

Lysophosphatidic acid enhances airway response to acetylcholine in guinea pigs

Inhalation of lysophosphatidic acid (LPA, 1-100 microg/ml) for 2 min enhanced the airway response induced by intravenous injection of ACh in guinea pigs. At 30 min after inhalation of LPA, the airway response to ACh was two fold higher than that before inhalation. This enhancement of airway response to ACh was partially inhibited by capsaicin desensitization or bilateral vagotomy. These results suggested that the enhancement of airway response to ACh induced by LPA may be due to the activation of capsaicin-sensitive fibers. It can be also contribute to bronchial asthma or other types of pulmonary disease such as cough variant asthma and atopic cough.

Physiological and pharmacological role of lysophosphatidic acid as modulator in mechanotransduction

The mechanotransduction mechanism is believed to play an important role in maintenance of cellular homeostasis in a wide variety of cell types. In particular, the mechanotransduction system in vascular endothelial cells may be an essential mechanism for local hemodynamic control. Elevations in intracellular free Ca2+ concentration ([Ca2]i) are an important signal in the initial step of mechanotransduction and mechanosensitive (MS) cation channels are thought to be a putative pathway; however, the molecular mechanisms remain unclear. We found that lysophosphatidic acid (LPA), a bioactive phospholipid, sensitizes the response of [Ca2+]i to mechanical stress in several cell types. Employing real-time confocal microscopy, local increases in [Ca2+]i in several regions within the cell during application of mechanical stress were clearly visualized in bovine lens epithelial and endothelial cells in the presence of LPA. The phenomenon was termed "Ca2+ spots". Pharmacological studies revealed that Ca2+ spots arise due to influx through MS channels. In this report, our data indicating the possible significance of LPA as an endogenous factor involved in regulation of mechanotransduction is reviewed. Furthermore, our findings suggest that the Ca2+ spot is a novel phenomenon occurring as an elementary Ca2+-influx event through MS channels directly coupled with the initial step in mechanotransduction.

A mechanism of Ca2+ release from Ca2+ stores coupling to the Na+/Ca2+ exchanger in cultured smooth muscle cells

We previously observed Ca2+ release from intracellular Ca2+ stores caused by reduction in extracellular Na+ concentration ([Na+]o). The purpose of this study was to determine whether lowering [Na+]o can elicit Ca2+ release from Ca2+ stores via the Na+/Ca2+ exchanger and to elucidate the mechanisms related to the Ca2+ release pathway in cultured longitudinal smooth muscle cells obtained from guinea pig ileum. Low [Na+]o-induced Ca2+ release was inhibited by antisense oligodeoxynucleotides for Na+/Ca2+ exchanger type 1 (anti-NCX). Application of anti-NCX to cells attenuated both the number of Ca2+ responding cells and the expression of the exchanger. Moreover, microinjection of heparin, a blocker of inositol 1,4,5-trisphosphate (IP3) receptors, into the cells inhibited low [Na+]o-induced Ca2+ release. These findings suggest that low [Na+]o-induced Ca2+ release occurs through an IP3-induced Ca2+ release mechanism due to changes in the Ca2+ flux regulated by the Na+/Ca2+ exchanger.

Effect of tributyltin chloride on the release of calcium ion from intracellular calcium stores in rat hepatocytes

The effects of tri-n-butyltin chloride (TBT), an environmental pollutant, on the release of Ca(2+) from intracellular stores were investigated in isolated rat hepatocytes. Isolated hepatocytes permeabilized with digitonin were suspended in solution, and the concentration of extracellular Ca(2+) was measured, using a fluorescent Ca(2+) dye, fura-2. In the solution containing permeabilized hepatocytes that had been preincubated with 4.0 microM TBT for 30 min, the extracellular Ca(2+) concentration was high, but the inositol 1,4,5-trisphosphate (InsP(3))-induced increase in Ca(2+) concentration was suppressed, suggesting that the extracellular release of Ca(2+) in response to TBT treatment was from intracellular stores. Images of the Ca(2+) concentration in the intracellular stores of primary cultured hepatocytes loaded with fura-2 were obtained after digitonin-permeabilization, using digitalized fluorescence microscopy. The permeabilized hepatocytes that had been preincubated with 4.0 microM TBT for 30 min had a very low fura-2 fluorescence ratio (340/380 nm), suggesting that stored Ca(2+) was released. When the hepatocytes were treated with 4.0 microM TBT after digitonin-permeabilization, the decrease in the fura-2 fluorescence ratio was very small. However, when the permeabilized hepatocytes were incubated with 4.0 microM TBT and 2.0 microM NADPH, the decrease was enhanced, raising the possibility that TBT might be metabolized to the active form(s), thus releasing Ca(2+) from intracellular stores. When the hepatocytes were preincubated with 0.1 microM TBT for 30 min and then were permeabilized, the fura-2 fluorescence ratio was almost the same as that in the control permeabilized hepatocytes. However, the InsP(3)-induced decrease in the fluorescence ratio was suppressed significantly in the permeabilized hepatocytes. These results suggest that TBT released Ca(2+) from the intracellular stores at high concentrations, and suppressed the InsP(3)-induced Ca(2+) release at non-toxic low concentrations. It is probable that the latter effect was responsible for the previously reported suppression of Ca(2+) response induced by hormonal stimulations (Kawanish et al., Toxicol Appl Pharmacol 1999;155:54-61).