Evaluation Of Resection Margins Research Articles

Intraoperative Frozen Section Evaluation of Pancreatic Specimens and Related Liver Lesions.

Frozen sections are essential in the surgical management of patients, especially those with pancreatic masses, because frozen sections can provide answers intraoperatively and aid in treatment decisions. Pancreas frozen sections are challenging because of the small tissue size, processing artifacts, neoadjuvant treatment effects, and concurrent pancreatitis-like obstructive changes. The authors present a review of intraoperative evaluation of pancreatic specimens. To provide an approach to the diagnosis of pancreatic adenocarcinoma on frozen sections and to discuss commonly encountered pitfalls. Indications for pancreas frozen sections and specific margin evaluation will be discussed. We will also review frozen section diagnosis of subcapsular liver lesions and tumors other than metastases of pancreatic ductal adenocarcinoma. Data sources included a literature review and the personal experiences of the authors. The features for diagnosis of pancreatic adenocarcinoma include disordered architecture, glands at abnormal locations, and atypical cytology. It is important to be aware of the pitfalls and clues on frozen section. The evaluation of resection margins can be challenging, and in the setting of the resection of cystic tumors, the key is the diagnosis of high-grade dysplasia or cancer. Finally, it is vital to remember the differential diagnosis for subcapsular liver lesions because not all lesions will be metastases of adenocarcinomas or bile duct adenomas. Frozen sections remain a useful tool for the intraoperative management of patients with pancreatic tumors.

A129 OUTCOMES FOLLOWING ENDOSCOPIC SUBMUCOSAL DISSECTION OF SUPERFICIAL GASTROINTESTINAL TRACT NEOPLASTIC LESIONS FROM A TERTIARY-CARE ACADEMIC CENTRE

Abstract Background Endoscopic submucosal dissection (ESD) is an advanced luminal resection technique for dysplastic and early cancerous gastrointestinal (GI) tract neoplasms. By removing lesions en bloc, this method provides more accurate histopathologic evaluation of resection margins in comparison to endoscopic mucosal resection (EMR). Superior curative resection and lower recurrence rates over EMR have been shown in addition to the benefit of reduced morbidity and mortality compared to surgery. While ESD has become well-established in Asia and Europe, its adoption in North America – and in particular Canada – has been slowed by multiple technical and economic factors including a scarcity of infrastructure, institutional support, and standardized training. Additionally, reproduced Canadian data corroborating its known global efficacy is currently lacking. Aims Our aim was to evaluate clinical and technical outcomes in patients who underwent ESD of superficial GI tract neoplasms at a tertiary-care academic centre. Methods We conducted a retrospective single-centre cohort study at The Centre for Advanced Therapeutic Endoscopy & Endoscopic Oncology, St. Michael’s Hospital, Toronto, Canada. Consecutive adults (age ampersand:003E 18) who underwent ESD of any superficial GI tract neoplasm from October 2017 to December 2022 were included in the study. Primary outcomes were rates of en bloc, complete (R0), and curative resections. Secondary outcomes were rates of recurrence and adverse events. Data was collected through electronic chart review. Results ESD was performed in a total of 308 lesions with a mean size of 2.5 cm (range, 1-7 cm). Gastric ESD was the most common (n=130), followed by esophageal (n=91), rectal (n=62), and colonic (n=22). Three patients underwent duodenal ESD. En bloc, R0, and curative resection rates were 89.2%, 84.7%, and 71.8%, respectively. 64.3% of lesions were cancerous on pathology (n=198), of which 48 had at least submucosal invasion. Rates of delayed bleeding and deep mural injury (DMI) requiring surgical intervention were 3.9% and 1.3%, respectively. Overall recurrence at the first surveillance endoscopy (SE1) was 3.6%. Conclusions En bloc, R0, and curative resection rates reported from this largest single-centre Canadian ESD cohort are comparable to existing North American data. Low rates of early recurrence and an adequate safety profile have been demonstrated with this emerging oncologic method of resection. Additional investigation is warranted to optimize lesion selection and determine long-term clinical outcomes to further establish this technique in the management of superficial GI tract neoplasms. Table I. Procedural characteristics, outcomes, and adverse events for patients who underwent ESD of superficial GI tract neoplasms. Funding Agencies None

P410 Intraoperative Ultrasonography of the Small Bowel in the evaluation of resection margins during surgery for Crohn's Disease

Abstract Background Histological involvement of surgical resection margins in Crohn’s Disease (CD) is considered an important risk factor for disease recurrence after surgery. The extent of resection is currently left to preoperative investigations and surgeon's experience. Aim of the study is to evaluate usefulness of intra-operative ultrasonography (IOUS) of the small bowel to best identify the surgical site of resection and reduce the risk of histological involvement of resection margins. Methods Consecutive patients who underwent surgery for CD (ileocaecal or ileal resections for first or repeated surgery) from April 2022 to April 2023 were prospectively enrolled (IOUS group). All patients underwent to IOUS through a small mini-laparotomy with a linear wireless probe performed by an expert gastroenterologist and the location of the proximal ileal resection was decided considering the absence of intraoperative small bowel ultrasonographic signs of CD (wall thickness, mucosal, submucosal and muscular layer thickness, echogenicity of the wall stratification and mesenteric fat). A control group from the historical cohort of patients undergoing the same surgical procedures was included; for whom the site of the proximal ileal resection was decided only on the basis of the absence of macroscopic signs of disease as usually assessed. To minimize the selection bias, a propensity score analysis was performed identifying a subgroup of the historical cohort (non-IOUS group) matched for location of disease and repeated surgery. The primary endpoint was histological involvement of the resection margins, judged positive in case of granulomas or signs of active ulcerative inflammation. Results 27 patients (59% male, mean age 39.3 y [SD 16.5], mean BMI 21.24 [SD 2.03]) were consecutively enrolled in the IOUS group. A 1:1 propensity score matching analysis was performed identifying 27 patients included in the non-IOUS group . The two groups were homogeneous in terms of gender, age, smoking, BMI, behavior of disease and surgical technique (laparoscopic or open technique). IOUS group presented a lower rate of histological positive margins compared to the non-IOUS group (18.5% vs 48.1% p = 0.021). No significant differences were found in terms of mean duration of surgery between the two groups (254.2 min vs 225 min [49.3-77.8]; p = 0.11) or in terms of mean length of surgical specimen (24.1 cm vs 34.1 cm [SD 13.5 -23.1]; p = 0.058) Conclusion IOUS of the small bowel appears to be a useful tool for IBD-surgeon in order to obtain a lower rate of histologically positive margins with a comparable duration of the surgery and no significant difference in length of the intestinal specimen.

Evaluation of Resection Margin by Intraoperative Frozen Section Biopsy in Breast Conservative Surgery for Early Breast Carcinoma

Background: Breast cancer is currently the second leading cause of cancer deaths in women. Early detection and accurate classification of suspicious masses as benign or malignant is important for arriving at an appropriate treatment plan. Aims: To evaluate the resection margin by intra-operative frozen section in breast conserving surgery for early breast carcinoma. Methods: This cross sectional study was carried out in the department of general surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. A total of 20 patients with early stage breast carcinoma underwent surgery were included in this study. Admitted patients with diagnosis of invasive ductal carcinoma of the breast, patient who gave consent for research purpose, patients diagnosed with stage I & II breast cancer, small (up to 4 cm) unifocal tumor and clinically negative axillary nodes were enrolled in this study. Statistical analyses of the results were obtained by using window based computer software devised with Statistical Packages for Social Sciences (SPSS-22). Results: It was observed that more than one third (40.0%) patients belonged to age 41-50 years. The mean age was 45.55±10.94 years with ranged from 28 to 75 years. Half (50.0%) patient’s educational level was primary. Majority (85.0%) patient’s occupational statuses were housewife. Majority (90.0%) patients had lump size >2-≤5 cm. The mean lump size was 2.89±0.66 cm with ranged from 1.5 to 4 cm. Three fourth (75.0%) patients had lump in the right breast. Almost two third (60.0%) patients had lump in the upper outer quadrant of breast. Two (10.0%) patients had Grade I and 18(90.0%) had Grade II tumor. Three fourth (75.0%) patients had resected tumor of T2 >2-≤5 cm size. The mean size of resected toumour was 2.65±0.62 cm with ranged from 1.4 to 3.8 cm. The frequency of positive resection margin on frozen section was 3 (15%). Among them 1 (33.3%) patient had positive superior margin and 2 (66.7%) had positive lateral ....

Cavity Shave Margins in Breast Conservative Surgery a Strategy to Reduce Positive Margins and Surgical Time.

Background: Resection of additional tissue circumferentially around the cavity left by lumpectomy (cavity shave) was suggested to reduce rates of positive margins and re-excision. Methods: A single center retrospective study which analyzed margins status, re-excision, and surgical time in patients who underwent breast conserving surgery and cavity shave or intraoperative evaluation of resection margins. Results: Between 2021 and 2023, 594 patients were enrolled in the study. In patients subjected to cavity shave, a significant reduction in positive, focally positive, or closer margins was reported 8.9% vs. 18.5% (p = 0.003). No difference was reported in terms of surgical re-excision (p < 0.846) (5% vs. 5.5%). Surgical time was lower in patients subjected to cavity shave (<0.001). The multivariate analysis intraoperative evaluation of sentinel lymph node OR 1.816 and cavity shave OR 2.909 were predictive factors for a shorter surgical time. Excluding patients subjected to intraoperative evaluation of sentinel lymph node and patients with ductal carcinoma in situ, patients that underwent the cavity shave presented a reduced surgical time (67.9 + 3.8 min vs. 81.6 + 2.8 min) (p = 0.006). Conclusions: Cavity shaving after lumpectomy reduced the rate of positive margins and it was associated with a significant reduction in surgical time compared to intraoperative evaluation of resection margins.

Diagnostic Usefulness of p53 Immunostaining in Gastric Cancer and Dysplasia: A Real-world Clinical Experience.

Gastric cancer and its precancerous lesions represent a significant public health concern. A subset of gastric cancers exhibits mutations in the TP53 gene, often accompanying distinctive morphologic alterations. This study aimed to assess the diagnostic efficacy of p53 immunostaining in real-world clinical settings. A retrospective analysis was conducted on 50 cases of gastric tumors and tumor-like lesions, wherein p53 immunostaining played a pivotal diagnostic role. The staining pattern of p53 was examined in conjunction with clinicopathologic parameters. Mutant p53 staining pattern demonstrated a significant association with high-grade nuclear atypia (p<0.001), high-grade dysplasia, and tubular adenocarcinoma (p<0.001), as well as microsatellite instability status (p=0.034). Furthermore, the diagnostic utility of p53 immunostaining was evident in scenarios where: 1) biopsy specimens contained few tumor cells, 2) pathologic evaluation of resection margins was limited by cauterization artifacts, and 3) distinction between low-grade and high-grade gastric dysplasia was challenging. P53 immunostaining can be helpful for the diagnosis of gastric tumor and tumor-like lesions, and accurate pathologic margin evaluation, particularly in lesions demonstrating intestinal-type differentiation and some degree of nuclear atypia.

Assessment of Gliomas' Grade of Malignancy and Extent of Resection Using Intraoperative Flow Cytometry.

Intraoperative Flow Cytometry (iFC) is a novel technique for the assessment of the grade of malignancy and the diagnosis of tumor type and resection margins during solid tumor surgery. Herein, we set out to analyze the role of iFC in the grading of gliomas and the evaluation of resection margins. iFC uses a fast cell cycle analysis protocol (Ioannina Protocol) that permits the analysis of tissue samples within 5-6 min. Cell cycle analysis evaluated the G0/G1 phase, S-phase, mitosis, and tumor index (S + mitosis phase fraction) and ploidy status. In the current study, we evaluated tumor samples and samples from the peripheral borders from patients with gliomas who underwent surgery over an 8-year period. Eighty-one patients were included in the study. There were sixty-eight glioblastoma cases, five anaplastic astrocytomas, two anaplastic oligodendrogliomas, one pilocytic astrocytoma, three oligodendrogliomas and two diffuse astrocytomas. High-grade gliomas had a significantly higher tumor index than low grade gliomas (median value 22 vs. 7.5, respectively, p = 0.002). Using ROC curve analysis, a cut-off value of 17% in the tumor index could differentiate low- from high-grade gliomas with a 61.4% sensitivity and 100% specificity. All low-grade gliomas were diploid. From the high-grade gliomas, 22 tumors were aneuploid. In glioblastomas, aneuploid tumors had a significantly higher tumor index (p = 0.0018). Twenty-three samples from glioma margins were evaluated. iFC verified the presence of malignant tissue in every case, using histology as the gold standard. iFC constitutes a promising intraoperative technique for glioma grading and resection margin assessment. Comparative studies with additional intraoperative adjuncts are necessary.

Evaluation of resection margins in oral squamous cell carcinoma.

Surgery is the primary treatment modality for oral squamous cell carcinoma. The purpose of the surgical procedure is complete removal of the tumor with asufficient margin of healthy tissue in its surroundings. Resection margins represent an important factor for planning further treatment and for estimation of the disease prognosis. Resection margins can be divided into negative, close and positive. Positive resection margins are considered aprognostically unfavorable factor. However, the prognostic significance of close resection margins is not entirely clear. The aim of this study was to evaluate the relationship between resection margins and disease recurrence, disease-free survival and overall survival. The study included 98 patients who underwent surgery for oral squamous cell carcinoma. During histopathological examination, resection margins of each tumor were evaluated by apathologist. The margins were divided into negative (&gt; 5 mm), close (0-5 mm), and positive (0 mm). Disease recurrence, disease-free survival and overall survival were evaluated according to the individual resection margins. Disease recurrence occurred in 30.6% of patients with negative, 40.0% with close, and 63.6% with positive resection margins. Significantly shorter disease-free survival and shorter overall survival in patients with positive resection margins was proven. The five-year survival rate was 63.9% in patients with negative, 57.5% with close, and only 13.6% with positive resection margins. The risk of death was 3.27times higher in patients with positive resection margins compared to patients with negative resection margins. Positive resection margins represent anegative prognostic factor, which was also confirmed in our study. There is no unequivocal consensus on the definition of close and negative resection margins and also on the prognostic significance of close resection margins. Factors that may contribute to inaccuracy in the evaluation of resection margins include tissue shrinkage after excision and after fixation of specimens before the histopathological examination. Positive resection margins were associated with asignificantly higher incidence of disease recurrence, shorter disease-free survival and shorter overall survival. When comparing the incidence of recurrence, disease-free survival, and overall survival between patients with close and negative resection margins, the differences were not statistically significant.

Assessing Resection Margin Status in Breast-conserving Surgery Specimens: Comparison Among Gross Evaluation, Frozen Section Analysis, and Permanent Section Diagnosis in 725 Patients With Breast Cancer.

An accurate evaluation of resection margin (RM) is critical in breast-conserving surgery (BCS) as negative RM status is critical for successful local control. We compared gross and microscopic methods for RM evaluation and analyzed their concordances. Gross evaluation (GE), frozen section analysis (FSA), and permanent section diagnosis (PSD) were compared for specimens from 725 breast cancer patients. The RM was grossly involved in 74 cases (10.2%). The sensitivity and specificity of GE were 22.9% and 96.1%, respectively. FSA revealed positive RM in 290 cases (40.0%), with high sensitivity (86.7%) and specificity (83.1%). With PSD, 240 cases (33.1%) showed RM involvement. Discordant results between gross and microscopic methods were observed in 104 cases (14.3%). Our observations of the low sensitivity of GE, high discordance rate between gross and microscopic methods, and high sensitivity and specificity of FSA support the necessity of intraoperative FSA for assessing RM status during BCS.

Instant diagnosis of gastroscopic biopsy via deep-learned single-shot femtosecond stimulated Raman histology

Gastroscopic biopsy provides the only effective method for gastric cancer diagnosis, but the gold standard histopathology is time-consuming and incompatible with gastroscopy. Conventional stimulated Raman scattering (SRS) microscopy has shown promise in label-free diagnosis on human tissues, yet it requires the tuning of picosecond lasers to achieve chemical specificity at the cost of time and complexity. Here, we demonstrate that single-shot femtosecond SRS (femto-SRS) reaches the maximum speed and sensitivity with preserved chemical resolution by integrating with U-Net. Fresh gastroscopic biopsy is imaged in <60 s, revealing essential histoarchitectural hallmarks perfectly agreed with standard histopathology. Moreover, a diagnostic neural network (CNN) is constructed based on images from 279 patients that predicts gastric cancer with accuracy >96%. We further demonstrate semantic segmentation of intratumor heterogeneity and evaluation of resection margins of endoscopic submucosal dissection (ESD) tissues to simulate rapid and automated intraoperative diagnosis. Our method holds potential for synchronizing gastroscopy and histopathological diagnosis.

Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry

BackgroundFlow Cytometry is an analytical technique for the precise quantification of cellular phenotype. Intraoperative Flow Cytometry (iFC) utilizes flow cytometry for DNA content/ploidy and cell cycle distribution analysis during surgery for cancer cell characterization and evaluation of tumor margins. Various types of cancers, including intracranial, head and neck, breast and liver malignancies have been evaluated with iFC. In the current study we present an intraoperative Flow Cytometry protocol for colorectal cancer cell detection and potential resection margin evaluation. Materials and methodsThis study includes 106 colorectal cancer patients in which samples from cancer and normal colon epithelium were prospectively collected intraoperatively and comparatively assessed with iFC. Patients' demographics, tumor data and cytometry parameters were assessed. ResultsWe have demonstrated that a cut-off value of 10.5% for tumor-index (fraction of cells in S and G2/M cell cycle phases) predicts with ∼91% accuracy (82.2% sensitivity and 99.9% specificity) the presence of cancer cells. Evaluation of tumor margins by iFC in the subpopulation of rectal cancer patients with or without neoadjuvant therapy, revealed an accuracy of 79% and 88%, respectively. ConclusionOur data support that regarding colorectal cancer, iFC is a useful adjunct method for tumor cell identification and probably margin evaluation, which could be utilized in rectal cancer treatment in the era of organ sparing procedures.

The Evaluation of the 1318 nm Diode Laser in Open Liver Surgery.

Simple SummaryThe surgical treatment of liver metastases but also of primary liver tumors is of particular clinical relevance in view of their high incidence. As a therapy option with a prospect of long-term survival in curative intent, liver resection plays a crucial role in modern multimodal treatment concepts. Advances in surgical and perioperative medicine have led to a reduction of procedural mortality to less than 5% and morbidity to around 35–45% and have rendered liver resections from high risk to routine procedures. Several comparisons of common parenchymal dissection techniques showed no specific advantages in favor of one of the methods in terms of morbidity, mortality and intraoperative blood loss. The aim of our retrospective study was to evaluate the 1318 nm diode pumped neodymium-yttrium aluminum garnet laser in open liver surgery. It could be shown that liver resections using the 1318 nm surgical laser can be carried out with an acceptable risk and are equally safe compared to conventional resection methods with comparatively little blood loss and favorable oncological surrogate outcomes.(1) Background: Numerous dissection instruments are available for liver resection. So far, there has been no evidence in favor of a specific dissection device effecting a reduction in postoperative mortality and morbidity or a reduction in intraoperative blood loss. The aim of the study was to evaluate the safety of liver resection with the 1318 nm surgical laser. (2) Methods: 151 consecutive patients who underwent liver resection using the 1318 nm surgical laser (n = 119) or conventional dissection methods (n = 32) were evaluated retrospectively. As primary outcome, postoperative complications were assessed using the Clavien–Dindo classification. Secondary outcomes were postoperative mortality, reoperations and reinterventions, intraoperative blood loss, the need for vascular control using the Pringle maneuver and oncological safety assessed through histopathological evaluation of resection margins. (3) Results: For liver resections using the 1318 nm surgical laser, the postoperative morbidity (41.2% vs. 59.4%, p = 0.066), mortality (1.7% vs. 3.1%, p = 0.513) and the reoperation rate (2.5% vs. 3.1%, p = 1.000) were not significantly different from conventional liver resections. In the laser group, a lower reintervention rate (9.2% vs. 21.9%, p = 0.050) was observed. The oncological safety demonstrated by a tumor-free resection margin was similar after laser and conventional resection (93.2% vs. 89.3%, p = 0.256). The median intraoperative blood loss was significantly lower in the laser group (300 mL vs. 500 mL, p = 0.005) and there was a significantly lower need for a Pringle maneuver (3.4% vs. 15.6%, p = 0.021). (4) Conclusions: Liver resections using the 1318 nm surgical laser can be routinely performed with a favorable risk profile. Compared to alternative resection methods, they are associated with low blood loss, appear adequate from an oncological point of view, and are not associated with increased mortality and morbidity.

P42.01 Tumor Size is an Independent Prognostic Factor after Pulmonary Metastasectomy

Patients selection for lung metastasectomy is mainly based on several prognostic factors such as disease-free interval (DFI), number of nodules, nodal involvement and radicality of the resection. The dimension of resected metastases is an indirect indicator of tumour burden and probably increases the risk of local recurrence but its impact on survival remains to be confirmed. The aim of this study was to test the hypothesis that larger metastases have a worse long-term outcome. Data from a cohort of patients who underwent pulmonary metastasectomy in the period 1998-2018 was analysed to test the impact on survival of the number and size (diameter of the largest resected metastases < vs > 2 cm) of resected lesions, nodal involvement and R0 resection. Patients with a follow-up time inferior to 3 years were excluded. Overall survival was measured according to Kaplan Meier method and groups were compared by the log-rank test. Clinical relevance of prognostic factors was tested by univariate analysis and significant variables (p<0.05) were inserted into a Cox multivariate model. The study group was composed of 314 patients (median age 58 years, males 44%) with different histology (epithelial 80%, sarcoma 13.7%, melanoma 4.5%, germ-cell tumors 1.9%) and a median disease-free interval of 50 months. A single metastasis was present in 289 cases (62.1%) and nodal involvement in 21 (6.7%). The largest resected lesion had a diameter less than 2 cm in 110 patients (41.4%). A radical resection was obtained in the majority of cases (293, 93.3%). Median survival in patients who had smaller metastases (<2 cm) was 63 months as compared to 55 months in those with larger lesions (figure 1, p 0.05). Multivariate analysis pointed out a more favourable outcome for patients having smaller (OR 0.54, CI 0.39-0.74) and single lesion (OR 0.58, CI 0.42-0.79), no nodal involvement (OR 0.5, CI 0.31-0.82) and who had an R0 resection (0.31, CI 0.16-0.58). Size of resected lesions is an independent prognostic factor after pulmonary metastasectomy. Whether this effect is due to a higher rate of local recurrence or the expression of a biologically more aggressive disease remains unclear. In any case, a very accurate evaluation of resection margins should be performed when large (> 2cm) metastases are removed.

Identification and Adjudication of Adverse Events Following Rectal Cancer Surgery: Observational Case Series in a Region of Ontario, Canada.

For patients undergoing rectal cancer surgery, we evaluated whether suboptimal preoperative surgeon evaluation of resection margins is a latent condition factor-a factor that is common, unrecognized, and may increase the risk of certain adverse events, including local tumour recurrence, positive surgical margin, nontherapeutic surgery, and in-hospital mortality. In this observational case series of patients who underwent rectal cancer surgery during 2016 in Local Health Integrated Network 4 region of Ontario (population 1.4 million), chart review and a trigger tool were used to identify patients who experienced the adverse events. An expert panel adjudicated whether each event was preventable or nonpreventable and identified potential contributing factors to adverse events. Among 173 patients, 25 (14.5%) had an adverse event and 13 cases (7.5%) were adjudicated as preventable. Rate of surgeon awareness of preoperative margin status was low at 50% and similar among cases with and without an adverse event (p = 0.29). Suboptimal surgeon preoperative evaluation of surgical margins was adjudicated a contributing factor in all 11 preventable local recurrence, positive margin, and nontherapeutic surgery cases. Failure to rescue was judged a contributing factor in the two cases with preventable in-hospital mortality. Suboptimal surgeon preoperative evaluation of surgical margins in rectal cancer is likely a latent condition factor. Optimizing margin evaluation may be an efficient quality improvement target.

Prospective Evaluation of Resection Margins Using Standardized Specimen Protocol Analysis among Patients with Distal Cholangiocarcinoma and Pancreatic Ductal Adenocarcinoma.

Purpose: Using a standardized specimen protocol analysis, this study aimed to evaluate the resection margin status of patients who underwent resection for either distal cholangiocarcinoma (DC) or pancreatic ductal adenocarcinoma (PDAC). This allowed a precise millimetric analysis of each inked margin. Methods: From 2010 to 2018, 355 consecutively inked specimens from patients with PDAC (n = 288) or DC (n = 67) were prospectively assessed. We assessed relationships between the tumor and the following margins: transection of the pancreatic neck, bile duct, posterior surface, margin toward superior mesenteric artery, and the surface of superior mesenteric vein/portal vein groove. Resection margins were evaluated using a predefined cut-off value of 1 mm; however, clearances of 0 and 1.5 mm were also evaluated. Results: Patients with DC were mostly men (64% vs. 49%, p = 0.028), of older age (68 yo vs. 65, p = 0.033), required biliary stenting more frequently (93% vs. 77%, p < 0.01), and received less neoadjuvant treatment (p < 0.001) than patients with PDAC. The venous resection rate was higher among patients with PDAC (p = 0.028). Postoperative and 90-day mortality rates were comparable. Patients with PDAC had greater tumor size (28.6 vs. 24 mm, p = 0.01) than those with DC. The R1 resection rate was comparable between the two groups, regardless of the clearance margin. Among the three types of resection margins, a venous groove was the most frequent in both entities. In multivariate analysis, the R1 resection margin did not influence patient survival in either PDAC or DC. Conclusion: Our standardized specimen protocol analysis showed that the R1 resection rate was comparable in PDAC and DC.

Evaluation of Resection Margin after Image-Guided Dural Tail Resection in Convexity Meningiomas.

Infiltration of adjacent dura with meningioma cells is a common phenomenon. Wide resection of the dural tail (DT) to achieve a gross total resection is a general recommendation. We aimed to investigate a tumor cell infiltration of the DT after image-guided resection of convexity meningiomas. The study’s inclusion criteria were the diagnosis of convexity meningioma, planned Simpson I° resection, and an identifiable DT. Intraoperative image-guidance was applied to identify the outer edge of the DT and to guide resection. After resection, en-bloc specimen or four samples of outermost pieces of DT in case of piecemeal resection were sent for histological analysis. In addition to resection margin infiltration, the radiological extent of DT, radiomic characteristics (109 in total), histology, and demographic data were assessed. Hierarchical clustering was used to generate patient clusters for radiomic analysis. Twenty-two patients were included in the study, while 20 (91%) were female. The mean age was 54.2 (Standard deviation (SD) 13.9, range 30–85) years. En-bloc resection could be achieved in 4 patients. The remaining patients received piecemeal resection. 2 DT samples were omitted due to tumor infiltration of the superior sagittal sinus. None of the en-bloc resection samples demonstrated dural infiltration on the resection margin. Tumor cells were detected in 4 of 70 (5.7%) dural tail samples and could not be excluded in another 5 of 70 (7.1%). No tumor recurrences were detected at follow-up MRI examinations after a mean follow-up of 27.5 (SD 13.2, range 0 to 50.0) months. There was no significant association between DT infiltration and histological subtype or patient characteristics and between DT extent and tumor infiltration. Clustering according to radiomic characteristics was not associated with tumor infiltration (p = 0.89). The radiological dural tail does not reliably outline the extent of tumor cell infiltration in convexity meningiomas. Hence, the extent of dural tail resection should not exclusively be guided by preoperative radiological appearance.

Intraoperative Evaluation of Resection Margins in Breast-Conserving Surgery for In Situ and Invasive Breast Carcinoma.

Background:The challenge of breast-conserving surgery (BCS) is to remove the entire tumour with free margins and avoid secondary excision that may adversely affect the cosmetic outcome. Consequently, intraoperative evaluation of surgical margins is critical. The aims of this study were multiple. First, to analyse our methodology of intraoperative examination of the resection margins and to evaluate radiological and pathological methods in the assessment of the surgical margins. Second, to evaluate the factors associated with positive margins in our patient population.M&m:The data on the resection margin status of 290 patients who underwent BCS for invasive carcinoma or ductal carcinoma in situ (DCIS) between 2009 and 2016 were reviewed.Results:In the cohort of BCS with invasive carcinoma, the negative predictive value was 97.4% for intraoperative assessment by radiography and 81.8% for intraoperative assessment by pathology. The re-operation rate among cases without intraoperative assessment was 23.6% compared to 7.3% among cases with intraoperative assessment (P = .003). Margin status was significantly associated with tumour size, histological subtype (invasive lobular carcinoma), and multifocality. In the population of BCS with DCIS, margin status was significantly associated with preoperative localisation and intraoperative margin assessment (P = .03).Conclusion:There is no statistical difference between pathological and radiological intraoperative assessment. Tumour size, lobular subtype, and multifocality were found to be significantly associated with positive margins in cases with invasive carcinoma, whereas absence of intraoperative margin assessment was significantly associated with positive margins in cases with DCIS. Therefore, intraoperative margin assessment improves the likelihood of complete excision of the lesion.

A three-dimensional printing navigational template combined with mixed reality technique for localizing pulmonary nodules.

Localizing non-palpable pulmonary nodules is challenging for thoracic surgeons. Here, we investigated the accuracy of three-dimensional (3D) printing technology combined with mixed reality (MR) for localizing ground glass opacity-dominant pulmonary nodules. In this single-arm study, we prospectively enrolled patients with small pulmonary nodules (<2 cm) that required accurate localization. A 3D-printing physical navigational template was designed based on the reconstruction of computed tomography images, and a 3D model was generated through the MR glasses. We set the deviation distance as the primary end point for efficacy evaluation. Clinicopathological and surgical data were obtained for further analysis. Sixteen patients with 17 non-palpable pulmonary nodules were enrolled in this study. Sixteen nodules were localized successfully (16/17; 94.1%) using this novel approach with a median deviation of 9 mm. The mean time required for localization was 25 ± 5.2 min. For the nodules in the upper/middle and lower lobes, the median deviation was 6 mm (range, 0-12.0) and 16 mm (range, 15.0-20.0), respectively. The deviation difference between the groups was significant (Z = -2.957, P = 0.003). The pathological evaluation of resection margins was negative. The 3D printing navigational template combined with MR can be a feasible approach for localizing pulmonary nodules.

Diagnostic Accuracy of Cross-Polarization OCT and OCT-Elastography for Differentiation of Breast Cancer Subtypes: Comparative Study.

The possibility to assess molecular-biological and morphological features of particular breast cancer types can improve the precision of resection margin detection and enable accurate determining of the tumor aggressiveness, which is important for treatment selection. To enable reliable differentiation of breast-cancer subtypes and evaluation of resection margin, without performing conventional histological procedures, here we apply cross-polarization optical coherence tomography (CP-OCT) and compare it with a novel variant of compressional optical coherence elastography (C-OCE) in terms of the diagnostic accuracy (Ac) with histological verification. The study used 70 excised breast cancer specimens with different morphological structure and molecular status (Luminal A, Luminal B, Her2/Neo+, non-luminal and triple-negative cancer). Our first aim was to formulate convenient criteria of visual assessment of CP-OCT and C-OCE images intended (i) to differentiate tumorous and non-tumorous tissues and (ii) to enable more precise differentiation among different malignant states. We identified such criteria based on the presence of heterogeneities and characteristics of signal attenuation in CP-OCT images, as well as the presence of inclusions/mosaic structures combined with visually feasible assessment of several stiffness grades in C-OCE images. Secondly, we performed a blinded reader study of the Ac of C-OCE versus CP-OCT, for delineation of tumorous versus non-tumorous tissues followed by identification of breast cancer subtypes. For tumor detection, C-OCE showed higher specificity than CP-OCT (97.5% versus 93.3%) and higher Ac (96.0 versus 92.4%). For the first time, the Ac of C-OCE and CP-OCT were evaluated for differentiation between non-invasive and invasive breast cancer (90.4% and 82.5%, respectively). Furthermore, for invasive cancers, the difference between invasive but low-aggressive and highly-aggressive subtypes can be detected. For differentiation between non-tumorous tissue and low-aggressive breast-cancer subtypes, Ac was 95.7% for C-OCE and 88.1% for CP-OCT. For differentiation between non-tumorous tissue and highly-aggressive breast cancers, Ac was found to be 98.3% for C-OCE and 97.2% for CP-OCT. In all cases C-OCE showed better diagnostic parameters independently of the tumor type. These findings confirm the high potential of OCT-based examinations for rapid and accurate diagnostics during breast conservation surgery.

Microbiological evaluation of resection margins of the infected diabetic foot ulcer

To evaluate the impact of surgical debridement on the microbiology of resection margins of an infected diabetic foot ulcer and to compare the use of marginal sampling as a guide for antimicrobial therapy. Forty consecutive participants were studied. Tissue samples from infected diabetic foot ulcers were obtained at first contact by podiatrists. After surgical debridement to macroscopically healthy tissue, multiple samples were obtained from the margins of the residuum and also from excised non-viable tissue. Debridement was done by a single surgeon. Bacterial species were classified according to pathogenic potential a priori into Red Group-Definite pathogen causing infection, Yellow Group-Likely to be causing infection if present in more than one specimen and Green Group -Commensals, not causing infection. There was a relative reduction of 49% (p=0.002) in bacteria in the most pathogenic (red) group, and 59% (p=0.002) in the yellow group in podiatry samples compared with resection specimen. Positive cultures from margins of the residuum were observed in 75% of cases. There was a relative reduction of 67% (p=0.0001) in bacteria in the red and 48% (p=0.06) in the yellow group in marginal samples from the residuum compared with podiatry samples. After surgical debridement to healthy tissue, positive cultures from marginal tissue samples provided vital information on the presence of pathogenic bacteria. This allowed antibiotics to be individualised post-surgical debridement.