Evaluation of Scissor Glide Characteristics Through Surgeons' Subjective Assessment: The Application of Nitriding in Scissor Hardening Tests.

INTRODUCTION: In robotic surgery, studies on providing tactile feedback to users are ongoing. However, the accuracy of the subjective sensations of surgeons, as users, has been largely unassessed. This study aimed to assess the validity of surgeons' subjective evaluations of scissors resistance through interindividual, inter-surgeon, and objective evaluations. Furthermore, in this study, we explored the possibility of using nitriding to increase the hardness of the scissors and assessed changes in subjective resistance values before and after nitriding using this approach. METHOD: Five surgeons conducted validation of five curved surgical scissors (145 mm; Arakawa Seisakujyo Co., Ltd., Tokyo, Japan) and assessed their subjective resistance using a scale from 0 to 10, where a rating of 10 signified significant resistance impeding the scissors' closure. The temporal changes in subjective resistance values, from maximum open to close, were graphically recorded. To demonstrate the reproducibility of subjective resistance values, the subjective resistance values of the same control scissors were measured at intervals of at least two weeks, and the correlation coefficient was calculated. To analyze the closing characteristics of subjective resistance values between different pairs of scissors, the effect of scissor type and scissor closure position was compared as two independent variables using a two-factor analysis of variance. A comparative evaluation was conducted to assess the frictional properties of scissors after nitriding, comparing the subjective assessment by surgeons with the objective assessment using a digital force gauge. RESULTS: The correlation coefficient of subjective resistance values measured by surgeons demonstrated a high reproducibility of 0.746. A two-factor analysis of variance conducted on subjective resistance values demonstrated the presence of a primary effect for the sample factor (scissors), as well as for the position factor (closing process), with the additional observation of the interaction between these two factors. The results from the two-factor analysis of variance above provide evidence supporting the validity of the subjective resistance measurements. There was a significant increase in subjective resistance after the nitriding process. The graph of subjective resistance values and objective resistance values showed similarity. CONCLUSIONS: The surgeons' subjective assessment of scissors resistance showed high reproducibility and validity, as evidenced by distinguishable differences in scissor movement interactions and pre- and post-nitriding resistance. Further studies are warranted to expand on these findings.

A Low Mean Closing Load and a Decrease in Load Change at the Tip Increase the Comfort of Scissors.

Introduction During surgery, surgeons intuitively recognize when they are using dull scissors and find them difficult to use. The purpose of this study was to objectively evaluate the physical characteristics of scissors and the comfort reported by surgeons to develop objective quality control standards for scissors used in surgery. Methods Sensory and measurement tests were conducted to evaluate the comfort and physical characteristics of ten pairs of Cooper scissors. As a sensory test, thirty-one volunteer surgeons opened and closed the scissors and selected three that felt comfortable and three that were uncomfortable. The results were scored. For measurement, a load was applied to the handle of the scissors. The load pressure and displacement of the width between each handle when the scissors were closed were measured. Results A strong negative correlation was found between the total comfort score and the mean load value between sensory and measurement tests (r=-0.717, p=0.0195). The correlation between the total score and the change in load at the tip showed a moderate negative correlation (r=-0.687, p=0.0282). Multiple regression analysis showed that the change in load at the tip was an independent factor affecting the total score. Conclusions Surgeons consider scissors with a low mean load required to close the scissors and a small change in load at the tip to be comfortable. The mean load on scissors and the change in load at the tip should be considered in the development of quality control standards for scissors used in surgery.

The effect of staple height and rectal-wall thickness on anastomotic leakage after laparoscopic low anterior resection.

BACKGROUND: The aim of this study was to evaluate the effect of staple height and rectal wall thickness on the development of an anastomotic leak after laparoscopic low anterior resection performed with the double stapling technique. METHODS: One hundred ninety-nine patients treated from 2013 to 2021 were enrolled. Patients were divided into two groups: those who developed an anastomotic leak (AL (+)) and those who did not (AL (-)). Clinicopathological factors were compared between the groups. RESULTS: Anastomotic leaks were observed in 8/199 patients (4%). A 1.5 mm linear stapler was used for 35/199 patients (17%), 1.8 mm for 89 (45%), and 2 mm for 75 (38%). In the AL (+) group (n = 8), lower staple height (1.5 mm or 1.8 mm) was used more frequently than in the AL (-) group (n = 191). Rectal wall thickness and the rectal wall thickness to staple height ratio was significantly (p < .05) greater in the AL (+) group. However, rectal wall thickness was significantly (p < .05) greater in patients who received neoadjuvant treatment and those with advanced T stage (T3,4) lesions. CONCLUSION: Linear stapler staple height and rectal wall thickness are significantly associated with the development of an anastomotic leak after laparoscopic low anterior resection. Larger staples should be selected in patients with a thicker rectal wall due to neoadjuvant treatment or adjacent advanced rectal tumors.

Metachronous Krukenberg tumor from adenocarcinoma in a Meckel's diverticulum: a case report.

Adenocarcinoma in a Meckel's diverticulum is rare and difficult to diagnose preoperatively. We report the first case of a metachronous Krukenberg tumor from adenocarcinoma in a Meckel's diverticulum. A 45-year-old woman was admitted for recurrent abdominal pain. Computed tomography scan showed a lesion with contrast enhancement, and a Meckel's diverticulum-associated tumor was suspected. Double-ballon enteroscopy revealed intestinal stenosis and biopsy showed adenocarcinoma. Operative findings showed a Meckel's diverticulum with tumor. Histopathological evaluation revealed well-differentiated adenocarcinoma, interrupted by ectopic gastric mucosa, diagnosed as adenocarcinoma in a Meckel's diverticulum. Two years postoperatively, a multi-cystic mass with contrast enhancement was observed in the pelvis on imaging evaluation and oophorectomy performed. Histological examination of the resected ovary showed proliferation of atypical glandular ducts, consistent with metastatic adenocarcinoma. This case demonstrates that adenocarcinoma in a Meckel's diverticulum may result in distant metastases and requires appropriate follow-up.

Intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine model.

PURPOSE: The aim of this study was to evaluate both the intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine survival model. METHODS: We used two suture models using two different size staples (incomplete mucosal closure model: group G [staple height 0.75 mm], complete mucosal closure model: group B [staple height 1.5 mm]) in the porcine ileum. Five staple lines were created in each group made in the ileum for each model, and the staple sites harvested on days 0, 2, and 7. The leak pressure at the staple site was measured at each time point. RESULTS: On day 0, the leak pressure for group G (79.5 mmHg) was significantly lower than that for group B (182.3 mmHg) (p < 0.01). On days 2 and 7, there was no significant difference between groups G and B (171 mmHg and 175.5 mmHg on day 2, 175.5 mmHg and 175.5 mmHg on day 7, p > 0.05). The histological findings in both groups showed similar healing at postoperative days 2 and 7. CONCLUSION: The integrity of the mucosal staple lines was associated with the postoperative leak pressure on day 0. However, there was no association with the leak pressure at two days or more postoperatively in a porcine model.

Flow cytometry detection of cell type-specific expression of programmed death receptor ligand-1 (PD-L1) in colorectal cancer specimens.

AIM: PD-1/PD-L1 blockade therapy is now widely used for the treatment of advanced malignancies. Although PD-L1 is known to be expressed by various host cells as well as tumor cells, the role of PD-L1 on non-malignant cells and its clinical significance is unknown. We evaluated cell type-specific expression of PD-L1 in colorectal cancer (CRC) specimens using multicolor flow cytometry. METHODS: Single cell suspensions were made from 21 surgically resected CRC specimens, and immunostained with various mAbs conjugated with different fluorescent dyes. Tumor cells, stromal cells, and immune cells were identified as CD326(+), CD90(+) and CD45(+) phenotype, respectively. CD11b(+) myeloid cells, CD19(+) B cells and CD4(+) or CD8(+) T cells were also stained in different samples, and their frequencies in the total cell population and the ratio of PD-L1(+) cells to each phenotype were determined. RESULTS: PD-L1 was expressed by all the cell types. The ratio of PD-L1(+) cells to CD326(+) tumor cells was 19.1% ± 14.0%, lower than those for CD90(+) stromal cells (39.6% ± 16.0%) and CD11b(+) myeloid cells (31.9% ± 14.3%). The ratio of PD-L1(+) cells in tumor cells correlated strongly with the ratio in stromal cells, while only weakly with that in myeloid cells. Tumor cells were divided into two populations by CD326 expression levels, and the PD-L1 positive ratios were inversely correlated with the rate of CD326 highly expressing cells as well as mean fluorescein intensity of CD326 in tumor cells, while positively correlated with the frequencies of stromal cells or myeloid cells in CRC. CONCLUSION: PD-L1 is differentially expressed on various cell types in CRC. PD-L1 on tumor cells may be upregulated together with CD326 downregulation in the process of epithelial mesenchymal transition. Quantification of cell type-specific expression of PD-L1 using multicolor flow cytometry may provide useful information for the immunotherapy of solid tumors.

[Primary Small Bowel Tumor with Simultaneous Lung Metastases from Rectal Cancer - A Case Report].

A 56-year-old woman was diagnosed with rectal cancer and liver metastases(Stage IV), and underwent low anterior resection and laparoscopic partial hepatectomy. The patient received adjuvant chemotherapy(mFOLFOX6 for 24 weeks), but developed multiple lung metastases 11 months later. Before undergoing a pulmonary resection, the patient presented with acute small bowel obstruction. Abdominal computed tomography showed small bowel stenosis due to a tumor, and we suspected peritoneal metastases from the rectal tumor. We performed partial resection of the small intestine, and histopathological examination revealed a primary small bowel tumor. The patient was discharged to her home without complications, and later underwent pulmonary resections for bilateral lung metastases. We usually suspect that small bowel obstruction is due to peritoneal metastases in patients with advanced colorectal tumors, but must consider the rare possibility of a separate primary small bowel tumor, especially in patients with a solitary lesion. We report a rare primary small bowel tumor after FOLFOX treatment in a patient with Stage IV rectal cancer.

Partial small intestinal resection for successful surgical management of refractory protein-losing gastroenteropathy in systemic lupus erythematosus: A case report and literature review.

RATIONALE: Although systemic lupus erythematosus (SLE) can be complicated by various gastrointestinal tract diseases, it is rarely associated with lupus enteritis and protein-losing enteropathy (PLE). We report here the successful surgical treatment of lupus enteritis and therapy-resistant and refractory PLE in a patient with SLE. We also provide a review of relevant literature. PATIENT CONCERNS: A 16-year-old girl presenting with polyarthritis, malar rash, and palmar erythema was indicated for steroid therapy on the basis of positive results for antinuclear, anti-Smith, and antiphospholipid antibodies, which confirmed the diagnosis of SLE. During the course of steroid therapy, the patient developed acute abdomen and hypoalbuminemia. DIAGNOSES: Computed tomography and Tc-labeled human serum albumin scintigraphy revealed abnormal findings, and a diagnosis of lupus enteritis and PLE was made. Steroid treatment was continued but no significant improvement was observed, and the patient was referred and admitted to our hospital. Double-balloon enteroscopy revealed multiple ischemic stenoses and mucosal necroses in the small intestine, suggesting that PLE was associated with ischemic enteritis due to antiphospholipid syndrome. The patient received steroids, immunosuppressive drugs, and antithrombotic therapy, with no improvement in symptoms. Thus, the disease was judged to be refractory and resistant to medical therapy, and the patient was indicated for surgical treatment. INTERVENTIONS: Partial small intestinal resection was performed by removing the segment of the small intestine presenting PLE lesions, and a double-end ileostomy was created. OUTCOMES: Multiple stenotic lesions were confirmed in the resected segment. Histopathology evaluation revealed marked inflammatory cell infiltration in the intestinal tract wall and recanalization of the vessels, suggesting a circulatory disorder caused by vasculitis and antiphospholipid syndrome. Postoperatively, the clinical course was good. Serum albumin levels and body weight increased as nutritional status improved significantly. Secondary enteroenterostomy with ileostomy closure could be performed at 2 months after the initial surgery. LESSONS: Timely surgical treatment can be successful in managing therapy-resistant and refractory PLE in patients with SLE.