Tumor Dissection Research Articles

A case with sarcomatoid hepatocellular carcinoma and literature review

Sarcomatoid hepatocellular carcinoma (SHC) is a relatively rare subtype of liver cancer reported in 1.8–2.0% of surgically resected cases. Previous studies have found that SHC was more likely to occur in patients who received repeated anticancer therapies, but the underlying mechanism has not been exactly illustrated. We report a case of a 62-year-old man with SHC. With the initial implication of abscess suspected liver mass by radiological exams (enhanced Computed Tomography and liver Magnetic Resonance Imaging), the patient underwent a laparoscopic pus debridement and biopsy. The diagnosis of SHC was considered by pathologists. After a short recovery, a second radical resection of the liver tumor and hepatic hilar lymph node dissection were conducted. Postoperative pathology revealed a tumor-free incisal margin and negative lymph node. The recovery of the patient was uneventful. When confronting an occasional liver mass with previous Hepatitis B virus infection, SHC should be included for a candidate diagnosis. If diagnosis is confirmed, high biological malignancy and poor survival should be expected. Surgery is still a main option to treat SHC.

Single-cell technologies uncover intra-tumor heterogeneity in childhood cancers.

Childhood cancer is the second leading cause of death in children aged 1 to 14. Although survival rates have vastly improved over the past 40years, cancer resistance and relapse remain a significant challenge. Advances in single-cell technologies enable dissection of tumors to unprecedented resolution. This facilitates unraveling the heterogeneity of childhood cancers to identify cell subtypes that are prone to treatment resistance. The rapid accumulation of single-cell data from different modalities necessitates the development of novel computational approaches for processing, visualizing, and analyzing single-cell data. Here, we review single-cell approaches utilized or under development in the context of childhood cancers. We review computational methods for analyzing single-cell data and discuss best practices for their application. Finally, we review the impact of several studies of childhood tumors analyzed with these approaches and future directions to implement single-cell studies into translational cancer research in pediatric oncology.

Developing a primary tumor and lymph node 18F-FDG PET/CT-clinical (TLPC) model to predict lymph node metastasis of resectable T2-4 NSCLC

PurposeThe goal of this study was to investigate whether the combined PET/CT radiomic features of the primary tumor and lymph node could predict lymph node metastasis (LNM) of resectable non-small cell lung cancer (NSCLC) in stage T2-4.MethodsThis retrospective study included 192 NSCLC patients who underwent tumor and node dissection between August 2016 and December 2017 and underwent 18F-fluorodeoxyglucose (18F-FDG) PET/CT scanning 1–3 weeks before surgery. In total, 192 primary tumors (> 3 cm) and 462 lymph nodes (LN > 0.5 cm) were analyzed. The pretreatment clinical features of these patients were recorded, and the radiomic features of their primary tumor and lymph node were extracted from PET/CT imaging. The Spearman’s relevance combined with the least absolute shrinkage and selection operator was used for radiomic feature selection. Five independent machine learning models (multi-layer perceptron, extreme Gradient Boosting, light gradient boosting machine, gradient boosting decision tree, and support vector machine) were tested as classifiers for model development. We developed the following three models to predict LNM: tumor PET/CT-clinical (TPC), lymph PET/CT-clinical (LPC), and tumor and lymph PET/CT-clinical (TLPC). The performance of the models and the clinical node (cN) staging was evaluated using the ROC curve and confusion matrix analysis.ResultsThe ROC analysis showed that among the three models, the TLPC model had better predictive clinical utility and efficiency in predicting LNM of NSCLC (AUC = 0.93, accuracy = 85%; sensitivity = 0.93; specificity = 0.75) than both the TPC model (AUC = 0.54, accuracy = 50%; specificity = 0.38; sensitivity = 0.59) and the LPC model (AUC = 0.82, accuracy = 70%; specificity = 0.41; sensitivity = 0.92). The TLPC model also exhibited great potential in predicting the N2 stage in NSCLC (AUC = 0.94, accuracy = 79%; specificity = 0.64; sensitivity = 0.91).ConclusionThe combination of CT and PET radiomic features of the primary tumor and lymph node showed great potential for predicting LNM of resectable T2-4 NSCLC. The TLPC model can non-invasively predict lymph node metastasis in NSCLC, which may be helpful for clinicians to develop more rational therapeutic strategies.

Cochlear Implantation Following Transcanal Infrapromontorial Approach for Vestibular Schwannoma: A Case Series.

Background: Cochlear implantation (CI) following endoscopic transcanal infrapromontorial vestibular schwannoma (VS) dissection is a feasible intervention in intracanalicular VS, with minimal extension into the cerebellopontine angle, but no audiologic results have ever been reported in the literature. Methods: From 2015 to 2021 in the Otorhynolaryngology Departments of Modena and Verona, three patients underwent this intervention. All were suffering from sporadic left-sided intracanalicular Koos I VS. Intraoperative electrically evoked auditory brainstem responses and electrophysiological measurements were performed before and after the placement of the electrode array, respectively. Since device activation one month after the surgery, each patient was followed up with audiometric tests, data logging, electrode impedance measurements and neural response telemetry performed at each scheduled fitting session at 15 days and 3, 6, 12 and 24 months. Results: Only in patient No. 3, an auditory benefit was observed and still evident even 36 months after activation. Impedances increased progressively in patient No. 1 and a benefit was never reported. Patient No. 2 left the follow-up for worsening comorbidities. Conclusions: CI following transcanal infrapromontorial VS resection is a beneficial intervention. The residual cochlear nerve after the tumour dissection and the course of electrophysiological measurements in the postoperative period were the main predictive factors for audiological outcomes.

Breast neuroendocrine tumor arising in the axilla of a man: a case report

BackgroundAccessory breast carcinomas of the axilla of males are rare, and primary breast neuroendocrine tumors (BNETs) are rare as well. We present a case of a BNET arising in the axilla of a man.Case presentationA 64-year-old Japanese man presented with a hard 15-mm mass in the axilla and axillary lymph node swelling. Histopathological examination of the incisional biopsy specimen revealed a neuroendocrine carcinoma. Therefore, wide radical excision of the axillary tumor and axillary lymph node dissection were performed. Hematoxylin and eosin staining showed that the solid tumor was mainly located in the subcutaneous adipose tissues and appeared to invade the skin. The tumor phenotypes were positive for CAM 5.2, synaptophysin, estrogen receptor, progesterone receptor, and GATA-binding protein 3; they were negative for human epidermal growth receptor 2. The neuroendocrine component comprised more than 90% of the tumor, and the Ki-67 index was 21%. These results indicated that the tumor was a BNET. This patient underwent adjuvant chemotherapy, endocrine therapy, and radiotherapy.ConclusionsBNET cases in males are rare. The clinical and histological criteria as well as treatment for these rare cases are discussed.

Benign submandibular gland tumours: outcomes of gland-preserving excision by endoscopic or conventional approach

Endoscope-assisted surgery is becoming a preferred technique in salivary gland surgery. However, this technique has not yet been applied in submandibular gland (SMG) preservation surgery. This retrospective study was performed to evaluate the outcomes of endoscope-assisted gland-preserving surgery through a hairline incision in patients with benign SMG tumours. The study included 38 patients with benign SMG tumours who underwent tumour excision with gland preservation: 19 who underwent local excision of the tumour through an endoscope-assisted hairline approach and 19 who received the conventional cervical approach. The feasibility of the surgical procedure, perioperative patient variables, and postoperative appearance and functional outcomes were evaluated. Patients in both groups had their tumours removed successfully with tumour-free margins. The intraoperative blood loss, postoperative amount of drainage, mean length of the incision, and unstimulated saliva flow rate did not differ between the two groups. There was no difference in the stimulated saliva flow rate between the preserved gland and unaffected SMG. The aesthetic result was better in the endoscope-assisted hairline incision group. No tumour recurrence occurred during follow-up (range 12–52 months). Thus, gland-preserving tumour dissection appears to be a safe method for benign SMG tumours, with good functional results. Furthermore, the endoscope-assisted hairline incision is a feasible method with excellent cosmetic results.

Multiregional single-cell dissection of tumor and immune cells reveals stable lock-and-key features in liver cancer

Intratumor heterogeneity may result from the evolution of tumor cells and their continuous interactions with the tumor microenvironment which collectively drives tumorigenesis. However, an appearance of cellular and molecular heterogeneity creates a challenge to define molecular features linked to tumor malignancy. Here we perform multiregional single-cell RNA sequencing (scRNA-seq) analysis of seven liver cancer patients (four hepatocellular carcinoma, HCC and three intrahepatic cholangiocarcinoma, iCCA). We identify cellular dynamics of malignant cells and their communication networks with tumor-associated immune cells, which are validated using additional scRNA-seq data of 25 HCC and 12 iCCA patients as a stable fingerprint embedded in a malignant ecosystem representing features of tumor aggressiveness. We further validate the top ligand-receptor interaction pairs (i.e., LGALS9-SLC1A5 and SPP1-PTGER4 between tumor cells and macrophages) associated with unique transcriptome in additional 542 HCC patients. Our study unveils stable molecular networks of malignant ecosystems, which may open a path for therapeutic exploration.

Mapping of lymph node dissection determined by the epicenter location and tumor extension for esophagogastric junction carcinoma.

Previous studies identified the extent of lymph node dissection for esophagogastric junction (EGJ) carcinoma based on the metastatic incidence. The study aimed to determine the optimal extent and priority of lymphadenectomy based on the therapeutic efficacy from each station. The studies on the lymph node metastasis (LNM) and therapeutic efficacy index (EI) for EGJ carcinomas were identified until April 2022. The obligatory stations with the LNM rates over 5% and therapeutic EI exceeding 2% should be routinely resected for D2 dissection, whereas the optional stations with EI between 0.5% and 2% should be resected for D3 dissection in selective cases. The survey yielded 16 eligible articles including 6,350 patients with EGJ carcinoma. The metastatic rates exceeded 5% at no. 1, 2, 3, 7, 9, 11p, and 110 stations and were less than 5% in abdominal no. 4sa~6, 8a, 10, 11d, 12a, and 16a2/b1 and mediastinal no. 105~112 stations. Consequently, obligatory stations with EI over 2% were largely determined by the epicenter location and located at the upper perigastric, lower mediastinal, and suprapancreatic zones, corresponding to those with rates of LNM over 5%. Consistent with the LNM rates less than 5%, the optional stations with EI between 0.5% and 2% were largely dependent on the degree of tumor extension toward the lower perigastric, splenic hilar (grecurvature), para-aortic (less curvature of the cardia), and middle or upper mediastinal zones. The obligatory stations can be resected as an "envelope-like" wrap by transhiatal proximal gastrectomy with lower esophagectomy, whereas the optional stations for dissection are indicated by the tumor extension. The extended gastrectomy is required for the lower perigastric in the stomach-predominant tumor with gastric involvement exceeding 5.0cm, para-aortic dissection in the less curvature-predominant tumor and splenic hilar dissection in the grecurvature-predominant tumor whereas transthoracic subtotal esophagectomy is required for complete mediastinal dissection and adequate negative margin in the esophagus-predominant tumor with esophageal invasion exceeding 3.0cm.

Long-term clinical outcomes of endoscopic submucosal dissection in rectal neuroendocrine tumors based on resection margin status: a real-world study.

Endoscopic submucosal dissection (ESD) has been widely adopted in treating rectal neuroendocrine tumors (NETs). However, clinical outcomes in rectal NETs after ESD with different resection margin status remain scanty, particularly in patients with positive resection margins. This study aimed to evaluate the long-term clinical outcomes of ESD in rectal NET based on the resection margin status. This retrospective study included 436 patients diagnosed with rectal NET who had undergone ESD. Clinical data, including age, sex, tumor size, stage, invasion, and the resection margin status, were collected. Further, the patients were assessed for complications, recurrence, distant metastasis, and long-term outcomes. Among all 436 patients, 395 patients had their primary ESD in our hospital. Complete resection was achieved in 319 patients. Patients who did not achieve complete resection opted for follow-up (n = 73), salvage surgery (n = 1) and salvage ESD (n = 2). Another 41 had their primary ESD in other hospital with incomplete resection and had salvage ESD in our hospital. All 436 patients had a median follow-up period of 61.4months (range 33.4-125.3months). During the follow-up period, two patients developed recurrences, while three patients developed metastasis. There were no significant differences in the 5-year progression-free survival and overall survival between patients with incomplete resection opting for follow-up compared to the other two groups (P = 0.5/0.8). However, the complication rates were significantly higher in patients who received salvage ESD. This study demonstrated that positive resection margins have no influence on survival in patients with rectal NET treated using ESD.

Squamous cell carcinoma of the oral alveolus during pregnancy: Perioperative management in a rural setting

A 30-year old pregnant woman presented to our hospital with stage 4 squamous cell carcinoma of the lower alveolus of the mouth. She underwent a transoral segmental resection of the tumour and left-modified radical neck dissection at 29 weeks of gestation. A multidisciplinary team was formed and careful consideration was given to preoperative evaluation, surgical and anaesthesia management, and postoperative care. The pregnancy was continued and the patient delivered a healthy baby at 35 weeks. This case highlights the perioperative interventions required to ensure the best possible outcomes for the mother and the baby.

SURG-21. DEVELOPMENT OF MICROSURGICAL FORCEPS EQUIPPED WITH HAPTICS TECHNOLOGY FOR IN SITU DIFFERENTIATION OF TUMOR TISSUE FROM NORMAL BRAIN DURING MICROSURGERY BY TISSUE STIFFNESS

Abstract Neurosurgeons perform tumor resection based on their tactile perception. However, many years of experience and training are required to appropriately differentiate tumor tissue from surrounding parenchymal tissue. It was reported that the stiffness of human cancer tissue strongly correlates with pathological tissue and it can be used as a biomarker. Comprehensive analysis also revealed that the molecular expression differs greatly between hard and soft tumors.Haptics technology measures and uses the stimulus that causes the sensation as a physical quantity. Force and tactile sensation is a sensation caused by mechanical contact with an object. Real Haptics is our main research field, which is a general term for technologies that quantify and utilize the force-tactile stimuli generated by contact with objects that exist in the real world and / or the virtual world.We have developed a microsurgical forceps equipped with haptics technology to differentiate tumor tissue from surrounding brain tissue during tumor dissection. We generated and used three glioblastoma cell lines (SF126, U87, U251) expressing proteins of firefly luciferase and mCherry. Each cell line was transplanted into forebrain of 5 nude mice. Tumor progression was regularly monitored with In Vivo Imaging System (IVIS) and mice were euthanized at the appropriate stage. Tumor and normal brain stiffness were measured by using the Master-slave integrated haptic forceps device. Importantly, all of the three glioblastomas were shown to be harder than the normal brain (p=0.047). The median stiffness of each tissue was as follows. Normal brain (n=15): 149.98 N/m, SF126 (n=5): 207.70 N/m, U87 (n=5): 214.40 N/m, U251 (n=5): 188.86 N/mThis pilot study showed that brain tumors could be differentiated by their stiffness from normal brain, and the forceps equipped with haptics technology might help the neurosurgeons to dissect tumor margin along the appropriate plane.

Traditional risk factors and nodal yield-still relevant with high-quality risk-adapted adjuvant treatment for locally advanced head and neck cancer?

Patients with locally advanced head and neck cancer (LAHNC) often undergo multimodal therapy including radical resection of the primary tumor and neck dissection (ND) followed by risk-adapted adjuvant radio(chemo)therapy (R(C)T). Quality parameters influencing local control and survival of these patients have been postulated: resection status (Rstatus), extranodal extension (ENE), interval to adjuvant treatment ≤6weeks, R(C)T given when indicated, and nodal yield (NY) ≥18lymph nodes per neck. For other solid tumors the trend is towards less extensive lymph node surgery to avoid toxicity such as lymphedema, damage to peripheral nerves, dysesthesia, or paresthesia. The present study aims to investigate whether the number of nodes removed during neck dissection for LAHNC is still predictive for outcome when patients receive risk-adapted adjuvant treatment according to current guidelines. Between 2008 and 2015, 468 patients with LAHNC undergoing R(C)T with curative intent were prospectively registered in adatabase (UICCIII/IV). Among them, 359 patients received adjuvant treatment and 295 underwent neck dissection. There were 119 (40%) patients with an oropharyngeal primary, 49 (17%) with cancer of the larynx/hypopharynx, 88 (30%) of the oral cavity, and 39 (13%) of the nasal/paranasal sinuses and cancer of unknown primary (CUP). Median follow-up was 45.6months. Histopathology revealed anR1 status in65 (22%) cases and ENE in93 (31%) cases. 150 (51%) patients received RCT; the median time to adjuvant treatment from the day of tumor resection was 44days (35-54) and overall treatment time (OTT; time from surgery to the last day of R(C)T) was 90days (82-101). Factors influencing disease-free survival (DFS) were adjusted and analyzed using CART analysis (removed nodes, number of positive nodes, body mass index (BMI), ENE, T and Nclassification, Rstatus, and primary site). Local control (LC), distant metastases-free survival (DMFS), and overall survival (OS) were analyzed using Kaplan-Meier statistics and multivariate analysis (MVA) for factors predictive for DFS and OS. CART analysis(Classification and Regression Trees) showed that T classification (T3/4) is the most important predictor for DFS, followed by age (> 61 years) and BMI (< 17.4). Primary site (OPC vs. other) and number of removed nodes (< 17) were shown to be less important for DFS, while ECE, Nclassification, and Rstatus seem to be of little relevance. MVA revealed number of positive nodes, non-OPC, and T3/4 to be negative predictive factors for DFS. For OS, the number of positive nodes and non-OPC primary were predictive. Five-year rates were 86.1% for LC, 87.9% DMFS, 76.5% DFS, and 67.2% for OS. In this patient cohort, the number of removed nodes is not relevant for DFS and OS, while the number of positive nodes and Tclassification have anegative impact on these endpoints. The high-risk factors positive resection margin and ECE seem to lose their negative impact on DFS and OS. High-quality care in head and oncology is only possible within aclose multidisciplinary team and network.

Intraoperative Prediction of Long-Term Remission in Acromegaly.

The features of long-term remission in acromegaly adenomectomy are incompletely understood. An intraoperative predictor for long-term outcome would be valuable for assessing resection of growth hormone (GH)-secreting tumors in real-time. To evaluate whether intraoperative GH measurement could predict long-term outcomes for acromegaly. In 47 patients, peripheral blood GH levels were measured thrice intraoperatively: once before tumor dissection, once during tumor dissection, and once after tumor dissection. Long-term remission was defined by age-appropriate, normalized insulin-like growth factor-1 at most recent follow-up and a random GH less than 1.0 ng/mL. Patients were only considered to be in long-term remission without the use of postoperative medical therapy for acromegaly or radiation therapy. The median length of follow-up was 4.51 (range: 0.78-9.80) years. Long-term remission was achieved in 61.7% (29/47) of operations. Like previous studies, cavernous sinus invasion (odds ratio [OR]: 0.060; 95% CI: 0.014-0.260; P value < .01), suprasellar extension (OR: 0.191; 95% CI: 0.053-0.681; P value<.01), and tumor size greater than 1 cm (OR: 0.177; 95% CI: 0.003-0.917; P value = .03) were associated with not being in long-term remission. The minimum GH measured intraoperatively predicted long-term outcome (area under the curve: 0.7107; 95% CI: 0.537-0.884; P value < .01). The odds ratio of remission in patients with the lowest quartile minimum intraoperative GH compared with patients with the highest quartile minimum intraoperative GH was 27.0 (95% CI: 2.343-311.171; P value < .01). Minimum intraoperative GH may predict long-term outcome for acromegaly, which in principle could provide the pituitary neurosurgeon with real-time feedback and inform intraoperative decision making.

Association of lymph node metastases, grade and extent of mesenteric lymph node dissection in locoregional small intestinal neuroendocrine tumors with recurrence-free survival.

We aimed to assess the prognostic impact of tumor- and patient-related parameters in patients with stage I-III small intestinal neuroendocrine tumors (SI-NETs), who underwent locoregional resective surgery (LRS) with curative intent. We included 229 patients with stage I-III SI-NETs diagnosed from June 15, 1993, through March 8, 2021, identified using the SI-NET databases from five European referral centers. Mean ± SD age at baseline was 62.5 ± 13.6 years; 111/229 patients were women (49.3%). All tumors were well-differentiated; 160 were grade 1 (G1) tumors, 51 were G2, two were G3 and 18 tumors were of unspecified grade (median Ki-67: 2%, range 1%-50%). One-hundred and sixty-three patients (71.2%) had lymph node (LN) involvement. The median number of retrieved lymph nodes was 10 (0-63), whereas the median number of positive LNs was 2 (0-43). After a mean ± SD follow-up of 54.1 ± 64.1months, 60 patients experienced disease recurrence at a median (range) of 36.2 (2.5-285.1) months. The 5- and 10-year recurrence-free survival (RFS) rates were 66.6% and 49.3% respectively. In univariable analysis, there was no difference in RFS and overall survival (OS) between LN-positive and LN-negative patients (log-rank, p=.380 and .198, respectively). However, in stage IIIb patients who underwent mesenteric lymph node dissection (MLND) with a minimum of five retrieved LN (n=125), five or more LN metastases were associated with shorter RFS (median RFS [95% CI]=107.4 [0-229.6] vs. 73.7 [35.3-112.1]months; log-rank, p=.048). In addition, patients with G2 tumors exhibited shorter RFS compared to patients with G1 tumors (median RFS [95% confidence interval (CI)]=46.9 [36.4-57.3] vs. 120.7 [82.7-158.8]months; log-rank, p=.001). In multivariable Cox-regression RFS analysis in stage IIIb patients, the Ki-67 proliferation index (hazard ratio=1.08, 95% CI=1.035-1.131; p < .0001) and the number of LN metastases (hazard ratio=1.06, 95% CI=1.001-1.125; p=.047) were independent prognostic factors for RFS. In conclusion, LRS with a meticulous MLND and a minimum number of five harvested LNs appears to be critical in the surgical management of SI-NET patients with locoregional disease. In patients who underwent LRS and MLND, the Ki-67 proliferation index and the LN metastases count were independent predictors of RFS.

Fluorescence guidance improves the accuracy of radiological imaging-guided surgical navigation.

Imaging-based navigation technologies require static referencing between the target anatomy and the optical sensors. Imaging-based navigation is therefore well suited to operations involving bony anatomy; however, these technologies have not translated to soft-tissue surgery. We sought to determine if fluorescence imaging complement conventional, radiological imaging-based navigation to guide the dissection of soft-tissue phantom tumors. Using a human tissue-simulating model, we created tumor phantoms with physiologically accurate optical density and contrast concentrations. Phantoms were dissected using all possible combinations of computed tomography (CT), magnetic resonance, and fluorescence imaging; controls were included. The data were margin accuracy, margin status, tumor spatial alignment, and dissection duration. Margin accuracy was higher for combined navigation modalities compared to individual navigation modalities, and accuracy was highest with combined CT and fluorescence navigation (p = 0.045). Margin status improved with combined CT and fluorescence imaging. At present, imaging-based navigation has limited application in guiding soft-tissue tumor operations due to its inability to compensate for positional changes during surgery. This study indicates that fluorescence guidance enhances the accuracy of imaging-based navigation and may be best viewed as a synergistic technology, rather than a competing one.

Outcome of using the spinal accessory nerve for functional muscle innervation in facial paralysis reconstruction: The first two cases in Vietnam and literature review

Abstract Facial nerve injuries with various causes, such as after trauma, tumor dissection, radiotherapy, etc., resulting the patient's functional, aesthetic, and psychological sequelae. For many decades, plastic surgeons have introduced numerous different nerve sources to overcome the above sequelae, such as contralateral facial nerve, the hypoglosal nerve, the masseter nerve, and the spinal accessory nerve (CN XI). There were various advantages and disadvantages of donor nerves sources. However, the use of ipsilateral donor nerve is said to have many benefits. In this report, we would like to present preliminary results of using the CN XI source in treatment of subacute and chronic VII nerve injury. These were the first two cases of successful surgery using this nerve source in Vietnam. Keywords: Facial nerve injury, facial paralysis, nerve transfer, spinal accessory nerve.

Fluorescein-Assisted Microsurgical Resection of Vestibular Schwannoma: A Prospective Feasibility Study.

To evaluate the optimal dose and timing of administration of sodium fluorescein (SF) for selective fluorescence of sporadic vestibular schwannoma (VS) during microsurgery with the YELLOW 560-nm microscope filter (YE560) and to characterize the potential benefit of this fluorescence as determined by intraoperative surgeon assessment. Prospective cohort study. Tertiary referral center. Adult patients undergoing VS microsurgery. Intraoperative intravenous administration of SF and visualization with the YE560. Time to differential fluorescence, duration of fluorescence, correlation of fluorescence of VS with electrostimulation and white light microscopy visual assessment, and likelihood of surgeons to use SF with the YE560 in future cases. Novel use of SF and YE560 during microsurgery achieved selective fluorescence of VS with capabilities to differentiate nerve fascicles and tumor approximately 30 minutes after administration. Nuances of SF administration and timing are discussed. Seventy-five percent of surgeons observed an excellent correlation of selective fluorescence with white light microscopy. Representative images and cases are presented. SF and YE560 may be used in VS microsurgery to visually differentiate VS from surrounding nerves. Potential benefits include enhanced visualization of the tumor-nerve interface for tumor dissection and detection of any residual disease, such as in the fundus after hearing preservation microsurgery.

PE44 - Postchemotherapy robotic retroperitoneal lymph node dissection for non-seminomatous germ cell tumors: Single-center, retrospective study to evaluate oncological and functional outcomes

PE44 - Postchemotherapy robotic retroperitoneal lymph node dissection for non-seminomatous germ cell tumors: Single-center, retrospective study to evaluate oncological and functional outcomes

Comparison of endoscopic submucosal resection with ligation and endoscopic submucosal dissection for small rectal neuroendocrine tumors: A multicenter retrospective study.

ObjectivesEndoscopic submucosal resection with band ligation (ESMR‐L) and endoscopic submucosal dissection (ESD) are both standard endoscopic resection methods for rectal neuroendocrine tumors (NETs) <10 mm in size. However, there is no definitive consensus on which is better. Here, we compared the efficacy of ESMR‐L and ESD for small rectal NETs.MethodsThis was a multicenter retrospective cohort study including 205 patients with rectal NETs who underwent ESMR‐L or ESD. Treatment outcomes were compared by univariate analysis, multivariate analysis, and inverse probability treatment weighting (IPTW) using propensity scores. Subgroup analysis evaluated the impact of the endoscopist's experience on the technical outcome.ResultsEighty‐nine patients were treated by ESMR‐L and 116 by ESD. The R0 resection rate was not significantly different between the two (90% vs. 92%, p = 0.73). The procedure time of ESMR‐L was significantly shorter than for ESD (17 min vs. 52 min, p < 0.01) and the hospitalization period was also significantly shorter (3 days vs. 5 days, p < 0.01). These results were confirmed by multivariate analysis and also after IPTW adjustment. The procedure time of ESD was significantly prolonged by a less‐experienced endoscopist (49 min vs. 70 min, p = 0.02), but that of ESMR‐L was not affected (17 min vs. 17 min, p = 0.27).ConclusionsFor small rectal NETs, both ESMR‐L and ESD showed similar high complete resection rates. However, considering the shorter procedure time and shorter hospitalization period, ESMR‐L is the more efficient treatment method, especially for less‐experienced endoscopists.

Appropriate Lymph Node Dissection Sites for Cancer in the Body and Tail of the Pancreas: A Multicenter Retrospective Study.

Simple SummaryDistal pancreatectomy has become the standard surgery for patients with pancreatic body–tail cancers. The optimal area for dissection remains controversial, and there is an emphasis on preserving as much tissue as possible while eradicating the cancer. This multicenter, retrospective study evaluated the frequency and patterns of lymph node metastasis based on tumor site among 235 patients with pancreatic body–tail cancers to determine the optimal lymph node dissection area for distal pancreatectomy. Patients with pancreatic body cancer tumors showed no metastasis to the splenic hilum lymph node. Spleen-preserving pancreatectomy might be feasible for Pb cancer.Distal pancreatectomy (DP) with lymphadenectomy is the standard surgery for pancreatic body–tail cancer. However, the optimal lymph node (LN) dissection area for DP remains controversial. Thus, we evaluated the frequency and patterns of LN metastasis based on the tumor site. In this multicenter retrospective study, we examined 235 patients who underwent DP for pancreatic cancer. Tumor sites were classified as confined to the pancreatic body (Pb) or pancreatic tail (Pt). The efficacy index (EI) was calculated by multiplying the frequency of metastasis to each LN station by the five-year survival rate of patients with metastasis to that station. LN metastasis occurred in 132/235 (56.2%) of the patients. Patients with Pb tumors showed no metastasis to the splenic hilum LN. Distal splenic artery LNs and anterosuperior/posterior common hepatic artery LNs did not benefit from dissection for Pb and Pt tumors, respectively. In multivariate analysis, splenic artery LN metastasis was identified as an independent predictor of poor overall survival in patients with pancreatic body–tail cancer. In conclusion, differences in metastatic LN sites were evident in pancreatic body–tail cancers confined to the Pb or Pt. Spleen-preserving pancreatectomy might be feasible for Pb cancer.