Superior Mesenteric Artery Margin Research Articles

Prognostic significance of involvement of the circumferential resection margin/surface in patients with pancreatic head cancer: A prospective evaluation of pancreatoduodenectomy specimens using the 0 and 1 mm rules

Background/ObjectivesThe prognostic significance of circumferential resection margin (CRM) or circumferential surface (CS) in pancreatic head cancer is controversial. We investigated the survival outcomes according to CRM or CS involvement in pancreatoduodenectomy specimens of pancreatic ductal adenocarcinoma (PDAC). MethodsA total of 102 pancreatoduodenectomy specimens after upfront surgery for PDAC between 2014 and 2018 were prospectively collected. The superior mesenteric vein/portal vein or superior mesenteric artery margins were classified as CRM, and the anterior or posterior surfaces as CS. Survival outcomes and recurrence were compared according to the CRM/CS status, which was categorized into R10mm, R11mm, and R0 (≥1 mm) by the 0 and 1 mm rules. ResultsFor CRM, R10mm had significantly lower overall survival (OS) (P < 0.001) and disease-free survival (P < 0.001) rates than R11mm and R0, with no difference between R11mm and R0. For CS, R0 had a significantly higher OS rate (P < 0.001) than R10mm and R11mm, with no difference between R10mm and R11mm. In multivariable analysis, R10mm CRM was an independent risk factor for OS (hazard ratio 2.410, P = 0.003) and DFS (hazard ratio 5.019, P < 0.001). When CRM/CS were analyzed separately, only the R10mm superior mesenteric artery margin was significantly associated with local recurrence (P = 0.012). ConclusionsThe results suggest that CRM involvement defined by the 0 mm rule is more appropriate than the 1 mm rule for predicting survival outcomes, but CS involvement defined by the 0 or 1 mm rules is not prognostically significant.

A Computer Vision Algorithm to Predict Superior Mesenteric Artery Margin Status for Patients with Pancreatic Ductal Adenocarcinoma.

To evaluate the feasibility of developing a computer vision algorithm that uses preoperative computed tomography (CT) scans to predict superior mesenteric artery (SMA) margin status in patients undergoing Whipple for pancreatic ductal adenocarcinoma (PDAC), and to compare algorithm performance to that of expert abdominal radiologists and surgical oncologists. Complete surgical resection is the only chance to achieve a cure for PDAC; however, current modalities to predict vascular invasion have limited accuracy. Adult patients with PDAC who underwent Whipple and had preoperative contrast-enhanced CT scans were included (2010-2022). The SMA was manually annotated on the CT scans, and we trained a U-Net algorithm for SMA segmentation and a ResNet50 algorithm for predicting SMA margin status. Radiologists and surgeons reviewed the scans in a blinded fashion. SMA margin status per pathology reports was the reference. Two hundred patients were included. Forty patients (20%) had a positive SMA margin. For the segmentation task, the U-Net model achieved a Dice Similarity Coefficient of 0.90. For the classification task, all readers demonstrated limited sensitivity, although the algorithm had the highest sensitivity at 0.43 (versus 0.23 and 0.36 for the radiologists and surgeons, respectively). Specificity was universally excellent, with the radiologist and algorithm demonstrating the highest specificity at 0.94. Finally, the accuracy of the algorithm was 0.85 versus 0.80 and 0.76 for the radiologists and surgeons, respectively. We demonstrated the feasibility of developing a computer vision algorithm to predict SMA margin status using preoperative CT scans, highlighting its potential to augment the prediction of vascular involvement.

The radiological morphology of mesopancreas: A new variable to predict a positive vascular margin after pancreatoduodenectomy for pancreatic ductal adenocarcinoma?

615 Background: The most frequently invaded surgical margins on pancreatoduodenectomy (PD) specimens of pancreatic ductal adenocarcinoma (PDAC) are vascular margins, especially the superior mesenteric artery (SMA), also called mesopancreatic margin. Considering embryology, it may be hypothesized that PDAC cells tend to infiltrate the retroperitoneum through the contents of mesopancreas, justifying the frequent SMA positive margin. Because the radiological aspect of mesopancreas has been poorly studied, the aim of this original research was to assess the mesopancreatic infiltration on diagnostic imaging, corroborate with the corresponding margin pathology and evaluate the impact on survival in PDAC patients who underwent PD. Methods: From 2015 to 2021, all patients who underwent PD for PDAC with curative intent were reviewed, excluding patients lost to follow-up, who died postoperatively or within the first year for non-oncological reason, and those with unavailable preoperative imaging. Surgical margins of pathological specimens were reassessed. Blinded reviewing of preoperative radiographic images was conducted. According to qualitative assessment, the mesopancreas tissue was defined as normal fat (NF), fat stranding (FS) or solid infiltration (SI). Results: 133 patients were included in the study, including 51 (38%) who received neoadjuvant therapy. The tumor location was into the head or the uncinate process in 54% and 46%, respectively. At diagnosis, PDAC were classified as resectable (51%), borderline resectable (28%) and locally advanced (9%) according to the NCCN classification. FS or SI in the mesopancreas was present in 45 (34%) and 18 (14%) patients, respectively. Tumor size on imaging, tumor location, chronic obstructive pancreatitis, vascular contacts and NCCN resectability status were predictive factors of mesopancreas infiltration (p&lt;0.001). Median overall and disease-free survivals were significantly lower in case of SI compared to NF and FS in the mesopancreas. When comparing patients with mesopancreatic FS at diagnosis who received neoadjuvant therapy (n=20) to those who underwent upfront surgery (n=25), no significant impact was observed in survivals. R0 resection was obtained in 36%; in all patients with R1 resection, a vascular margin was involved. Tumor size at pathology, SMA margin and resection status were factors that were significantly influenced by the radiological infiltration of the mesopancreas. Conclusions: The SI of mesopancreas on diagnostic imaging was associated with a poor prognosis, but not FS, in patients who underwent PD for PDAC. SMA margin and resection status were correlated with the radiological texture of the mesopancreas, which suggests to further explore underlying mechanisms related to tumoral invasion of vascular margin and mesopancreas.

Prognostic value of margin clearance in total and distal pancreatectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BackgroundThe prognostic role of resection margin status following total (TP) and distal (DP) pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) is insufficiently evaluated. In Denmark, pancreatic surgery, including the postoperative pathological examination of the resection specimens, is confined to four centres, all reporting to the Danish Pancreatic Cancer Database (DPCD). In this Danish population-based nationwide study on TP and DP for PDAC from 2015–2019, based on data from DPCD, we evaluated whether there is a prognostically relevant minimum margin clearance definition and whether certain margins hold independent prognostic information. MethodsClinical and pathological data were retrieved from DPCD and supplemented by review of pathology reports and re-microscopy, if needed. One of the study pathologists performed all re-microscopy. The prognostic significance of margin status was evaluated by dichotomisation of the TP cohort (n = 101) and the DP cohort (n = 90) into involved and uninvolved groups, using different clearance definitions (0.5 – ≥3.0 mm). ResultsFollowing TP, direct involvement of the superior mesenteric artery (SMA) margin had independent prognostic value. When using a clearance definition of ≥ 0.5 or ≥ 1.5 mm for SMA, median survival for R0 versus R1 was 19 (95% CI 14–26) versus 10 (95% CI 5–20) months (p = 0.010), and 21 (95% CI 15–30) versus 10 (95% CI 8–19) months (p = 0.011), respectively. Overall margin status was not of significant prognostic importance following neither DP nor TP. ConclusionIn this Danish population-based nationwide study, SMA margin involvement was a significant isolated prognostic factor following TP, whereas combined assessment of all circumferential margins did not hold statistically significant prognostic information. Following DP, resection margin status did not affect survival.

Proposing an Imaging-based Morphological Assessment of Pancreatic Ductal Adenocarcinoma as a Predictor of R1 Resection

Introduction: Pancreatic ductal adenocarcinoma (PDAC) can be clinically under-staged on preoperative cross-sectional imaging which may affect intraoperative resectability. The purpose of this study is to define imaging-based morphologic criteria for PDAC in tumors deemed resectable at presentation and assess their correlation with R1 resection. Methods: A retrospective chart review of 54 consecutive pancreatoduodenectomies performed for PDAC between 2016- 2018 was performed. Sectional computed Tomography (CT) images were reviewed by two senior radiologists who labeled tumors as “mass-forming” or “infiltrative” morphology. These classifications were then correlated with resection margin status. Significance was defined as a p value <0.1. Results: Of the 54 patients included in the study, 28 and 26 were classified as mass forming and infiltrative based on radiological review, respectively. There was no significant difference in pathological T and N staging (p=0.63 and p=0.62, respectively). Infiltrative tumors demonstrated smaller sizes on preoperative images (average: 3.3 versus 4 cm, p=0.02). Although no difference was appreciated between both morphologies regarding portal vein and superior mesenteric artery margins (p=0.64 and p=0.81, respectively), infiltrative tumors were found to be associated with more positive bile duct and pancreatic margins (p=0.06 and p=0.07, respectively). Conclusion: We propose a new imaging-based definition of PDAC into “mass-forming” and “infiltrative” morphologies. Understanding the higher rate of R1 resection in infiltrative tumors would improve selection process of patients with PDAC to neoadjuvant therapy prior to definitive resection.Tabled 1Radiological featureMass-formingInfiltrativeBorderPresence of a well-defined interfaceAbsence of a well-defined interfaceMassVisible and clearly identifiableInferred in the absence of a clear mass and presence of pancreatic and/or common bile ductal dilationp Open table in a new tab

Diagnostic Accuracy of CT for Evaluating Circumferential Resection Margin Status in Resectable or Borderline Resectable Pancreatic Head Cancer: A Prospective Study Using Axially Sliced Surgical Pathologic Correlation

ObjectiveCT plays a central role in determining the resectability of pancreatic cancer, which directs the use of neoadjuvant therapy. This study aimed to assess the diagnostic accuracy of CT in predicting circumferential resection margin (CRM) involvement in patients with resectable or borderline resectable pancreatic head cancer.Materials and MethodsSeventy-seven patients who were scheduled for upfront surgery for resectable or borderline resectable pancreatic head cancer were prospectively enrolled, and 75 patients (38 male and 37 female; mean age ± standard deviation, 68 ± 11 years) were finally analyzed. The CRM status was evaluated separately for the superior mesenteric artery (SMA) and posterior and superior mesenteric vein/portal vein (SMV/PV) margins. Three independent radiologists reviewed the preoperative CT images and evaluated the resection margin status. The reference standard for CRM status was pathologic examination of pancreaticoduodenectomy specimens in an axial plane perpendicular to the axis of the second portion of the duodenum. The diagnostic accuracy of CT was assessed for overall CRM involvement, defined as involvement of the SMA or posterior margins (per-patient analysis), and involvement of each of the three resection margins (per-margin analysis). The data were pooled using a crossed random effects model.ResultsForty patients had pathologically confirmed overall CRM involvement in pancreatic cancer, while CRM involvement was not seen in 35 patients. For overall CRM involvement, the pooled sensitivity and specificity were 15% (95% confidence interval: 7%–49%) and 99% (96%–100%), respectively. For each of the resection margins, the pooled sensitivity and specificity were 14% (9%–54%) and 99% (38%–100%) for the SMA margin, 12% (8%–46%) and 99% (97%–100%) for the posterior margin; and 37% (29%–53%) and 96% (31%–100%) for the SMV/PV margin, respectively.ConclusionCT showed very high specificity but low sensitivity in predicting pathological CRM involvement in pancreatic cancer.

Impact of Total Mesopancreas Excision on the Superior Mesenteric Artery Margin Status

Introduction: Pancreatic ductal head adenocarcinoma (PDHAC) is a lethal disease with poor prognosis and surgical resection with complete microscopic resection (R0) in association with multimodal treatment currently represents the only curative strategy. The dissected margins around the superior mesenteric artery (SMA) are reported to be the most favorable R1 site for PDHAC. Therefore, modifications have been made to the classic surgical technique (Whipple) to improve the rate of R1 resections, such as the total mesopancreas excision (TMpE). The purpose of this study was to evaluate the impact of TMpE on the SMA margin status. Methods: This study included 93 patients with PDHAC who were treated in the Hepatobiliary Surgery Department of Miguel Servet University Hospital in Saragossa, Spain, during a 7-years period (2010-2017). They were divided into two groups. Group A included patients who underwent pancreaticoduodenectomy (PD) with TMpE and group B included standar PD (S-PD). The collected data were prospectively collected and statistically analyzed by SPSS 19.0 statistical software package. Results: The R0 resection rate was 52.1% (25/48) in Group A and 31.1% (14/45) in Group B. There was significant difference in the R0 resection rate between the two groups (p=0.027). The R1 SMA resection margin rate was 18. Conclusions: TMpE improves the oncological results of PD for pancreatic head adenocarcinoma as it halves the rate of R1 resections at the SMA resection margin.

CT Radiomic Features of Superior Mesenteric Artery Involvement in Pancreatic Ductal Adenocarcinoma: A Pilot Study.

Background Current imaging methods for prediction of complete margin resection (R0) in patients with pancreatic ductal adenocarcinoma (PDAC) are not reliable. Purpose To investigate whether tumor-related and perivascular CT radiomic features improve preoperative assessment of arterial involvement in patients with surgically proven PDAC. Materials and Methods This retrospective study included consecutive patients with PDAC who underwent surgery after preoperative CT between 2012 and 2019. A three-dimensional segmentation of PDAC and perivascular tissue surrounding the superior mesenteric artery (SMA) was performed on preoperative CT images with radiomic features extracted to characterize morphology, intensity, texture, and task-based spatial information. The reference standard was the pathologic SMA margin status of the surgical sample: SMA involved (tumor cells ≤1 mm from margin) versus SMA not involved (tumor cells >1 mm from margin). The preoperative assessment of SMA involvement by a fellowship-trained radiologist in multidisciplinary consensus was the comparison. High reproducibility (intraclass correlation coefficient, 0.7) and the Kolmogorov-Smirnov test were used to select features included in the logistic regression model. Results A total of 194 patients (median age, 66 years; interquartile range, 60-71 years; age range, 36-85 years; 99 men) were evaluated. Aside from surgery, 148 patients underwent neoadjuvant therapy. A total of 141 patients' samples did not involve SMA, whereas 53 involved SMA. A total of 1695 CT radiomic features were extracted. The model with five features (maximum hugging angle, maximum diameter, logarithm robust mean absolute deviation, minimum distance, square gray level co-occurrence matrix correlation) showed a better performance compared with the radiologist assessment (model vs radiologist area under the curve, 0.71 [95% CI: 0.62, 0.79] vs 0.54 [95% CI: 0.50, 0.59]; P < .001). The model showed a sensitivity of 62% (33 of 53 patients) (95% CI: 51, 77) and a specificity of 77% (108 of 141 patients) (95% CI: 60, 84). Conclusion A model based on tumor-related and perivascular CT radiomic features improved the detection of superior mesenteric artery involvement in patients with pancreatic ductal adenocarcinoma. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Do and Kambadakone in this issue.

R Status is a Relevant Prognostic Factor for Recurrence and Survival After Pancreatic Head Resection for Ductal Adenocarcinoma.

The prognostic role of resection margins in pancreatic ductal adenocarcinoma (PDAC) is debated. This study aimed to investigate the impact that global and individual resection margin status after pancreatic head resection for PDAC has on disease-free survival (DFS) and disease-specific survival (DSS). Surgical specimens of pancreaticoduodenectomy/total pancreatectomy performed for PDAC were examined with a standardized protocol. Surgical margin status (biliary, pancreatic neck, duodenal, anterior and posterior pancreatic, superior mesenteric vein groove and superior mesenteric artery margins) was classified as the presence of malignant cells (1) directly at the inked surface (R1 direct), (2) within less than 1 mm (R1 ≤ 1 mm), or (3) with a distance greater than 1 mm (R0). Patients with a positive neck margin at the final histology were excluded from the study. Of the 362 patients included in the study, 179 patients (49.4 %) had an R0 resection, 123 patients (34 %) had an R1 ≤ 1 mm resection, and 60 patients (16.6 %) had an R1 direct resection. The independent predictors of DFS were R1 direct resection (hazard ratio [HR], 1.49), R1 ≤ 1 mm resection (HR, 1.38), involvement of one margin (HR, 1.36), and involvement of two margins or more (HR, 1.55). When surgical margins were analyzed separately, only R1 ≤ 1 mm superior mesenteric vein margin (HR, 1.58) and R1 direct posterior margin (HR, 1.69) were independently associated with DFS. Positive R status is an independent predictor of DFS (R1 direct and R1 ≤ 1 mm definitions) and of DSS (R1 direct). The presence of multiple positive margins is a risk factor for cancer recurrence and poor survival. Different surgical margins could have different prognostic roles.

Factors Associated with Overall Survival in Pancreatic Cancer Treated with Neoadjuvant Therapy and Surgery

Introduction: Median survival following surgical resection of pancreatic cancer (PC) has increased due to advances in chemotherapy, radiotherapy, and surgical technique. We examined clinical factors associated with overall survival (OS) in patients with PC who received neoadjuvant therapy and surgery. Method: We conducted a retrospective review of a prospectively maintained PC database at high-volume referral center. Patients with non-metastatic PC who received neoadjuvant therapy and underwent surgical resection between 2009 and 2019 were included. Demographic, clinical, and pathologic variables were examined with Cox proportional hazards models to identify prognostic factors on OS. Results: Neoadjuvant therapy and surgery was completed in 460 consecutive patients; 227 (49.4%) patients were female. The median age was 64 (IQR[58, 71]) years. Median OS was 40.2 (IQR[23.4, 87.3]) months. On bivariate analysis, elevated CA19-9 prior to surgery (HR 1.8 [1.4,2.3]), vein resection (HR 1.6 [1.2, 2.1]), lymphovascular invasion (HR 1.5 [1.1, 2.0]), positive superior mesenteric artery margin (HR 1.8 [1.2, 2.7]) and higher nodal stage were associated with worse OS. On multivariate analysis, shorter OS was associated with increased CA19-9 (HR 1.6 [1.2,2.2]), higher nodal stage (HR 1.5 [1.0, 2.1] for N1; HR 1.9 [1.2, 3.0] for N2), and liver as the first site of disease recurrence. Preoperative clinical stage was not a significance predictor of OS. Conclusions: We report OS outcomes from one of the largest cohorts of resected PC in the era of neoadjuvant therapy. Preoperative CA19-9 after neoadjuvant therapy was associated with OS, emphasizing the impact of treatment response on OS.

Clinicopathological correlation of radiologic measurement of post-therapy tumor size and tumor volume for pancreatic ductal adenocarcinoma

ObjectivesTumor size measurement is critical for accurate tumor staging in patients with pancreatic ductal adenocarcinoma (PDAC). However, accurate tumor size measurement is challenging in patients who received neoadjuvant therapy before resection, due to treatment-induced fibrosis and tumor invasion beyond the grossly identified tumor area. In this study, we evaluated the correlation between the tumor size and tumor volume measured on post-therapy computed tomography (CT) scans and the pathological measurement. Also, we investigated the correlation between these measurements and clinicopathological parameters and survival. Materials and methodsRetrospectively, we evaluated 343 patients with PDAC who received neoadjuvant therapy, followed by pancreaticoduodenectomy and had pre-operative pancreatic protocol CT imaging. We measured the longest tumor diameter (RadL) and the radiological tumor volume (RadV) on the post-therapy CT scan, then we categorized RadL into four radiologic tumor stages (RTS) based on the current AJCC staging (8th edition) protocol and RadV based on the median. Pearson correlation or Spearman’s coefficient (δ), T-test and ANOVA was used to test the correlation between the radiological and pathological measurement. Chi-square analysis was used to test the correlation with the tumor pathological response, lymph-node metastasis and margin status and Kaplan-Meier and Cox-proportional hazard for survival analysis. P-value < 0.05 was considered significant. ResultsAs a continuous variable, RadL showed a positive linear correlation with the post-therapy pathologic tumor size in the overall patient population (Pearson correlation coefficient: 0.72, P < 0.001) and RadV (δ: 0.63, p < 0.0001). However, there was no correlation between RadL and pathologic tumor size in patients with ypT0 and those with pathologic tumor size of ≤1.0 cm. Post-therapy RTS and RadV group correlated with ypT stage, tumor response grades using either CAP or MDA grading system, distance of superior mesenteric artery margin and tumor recurrence/metastasis. ConclusionAlthough RadL tends to understage ypT in PDAC patients who had no radiologically detectable tumor or small tumors (RTS0 or RTS1), radiologic measurement of post-therapy tumor size may be used as a marker for the pathologic tumor staging and tumor response to neoadjuvant therapy.

Recurrence patterns of pancreatic cancer after pancreatoduodenectomy: systematic review and a single-centre retrospective study

BackgroundPositive margins in pancreatoduodenectomy (PD) for pancreatic cancer, specifically the superior mesenteric artery (SMA) margin, are associated with worse outcomes. Local therapies targeting these margins could impact on recurrence. This study analysed recurrence-patterns to identify whether strategies to control local disease could have a meaningful impact. Methods(I) Systematic review to define recurrence patterns and resection margin status. (II) Additional retrospective study of PD performed at our centre. ResultsIn the systematic review, 23/617 evaluated studies were included (n = 3815). Local recurrence was observed in 7–69%. SMA margin (6 studies) was positive in 15–35%. In the retrospective study (n = 204), local recurrence was more frequently observed with a positive SMA margin (66 vs.45%; p = 0.005). Furthermore, in a multivariate cox-proportional hazard model, only a positive SMA margin was associated with disease recurrence (HR 1.615; 95%CI 1.127–2.315; p = 0.009). Interestingly, median overall survival was 20 months and similar for patients who developed local only, metastases only or simultaneous recurrence (p = 0.124). ConclusionLocal recurrence of pancreatic cancer is common and associated with similar mortality rates as those who present with simultaneous or metastatic recurrence. Involvement of the SMA margin is an independent predictor for disease progression and should be the target of future adjuvant local therapies.

Arterial revascularization following acute mesenteric ischemia.

Assessment of a pancreaticoduodenectomy specimen by pathologists requires specialized knowledge of anatomy. Standardized assessment, description and documentation of the retroperitoneal margin are crucial for the accurate interpretation of studies evaluating adjuvant therapy for pancreatic cancer patients.Twenty‐five patients who underwent a pancreaticoduodenectomy for pancreatic adenocarcinomas had their pathological specimens examined prospectively, using an anatomical‐based mapping approach. All margins, including the bile duct, pancreatic neck, superior mesenteric artery, superior mesenteric vein and posterior surface of the uncinate process, were microscopically examined in their entirety. The assessment of an R1 margin in terms of distance was assessed in two ways: first defining it as a tumour at the margin or secondary as tumour within 1 mm (1 mm rule).If the existing College of American Pathologists recommendations were applied (assessing only the bile duct, pancreatic neck and superior mesenteric artery margins), a R1 status would be achieved in only 9 of 25 patients. Extending the examination by assessment and reporting of the entire retroperitoneal resection margin, including the Superior Mesenteric Vein margin and the Posterior surface of the uncinate process margin, increased the number of patients with a R1 resection to 14 out of 25. Applying the 1‐mm rule further increased the number of patient with a R1 resection to 20 of 25 patients.The above findings illustrate that different approaches to the assessment and reporting of the retroperitoneal margin can change the results and adversely affect the final statistics used in pancreatic cancer studies and clinical trials.

Three-Dimensional Fixation: Pathological Protocol Following Pancreaticoduodenectomy with Portal Vein Resection for Pancreatic Cancer

BackgroundAlthough existing histopathologic protocols for pancreatic cancer have been standardized, the relevance between prognosis and resection margin clearance is still controversial. Reconstruction of specimens as in situ to appropriately assess the margin is desirable in these protocols. MethodsThe three-dimensional fixation protocol defined specimen handling of pancreaticoduodenectomy (PD) with portal vein (PV) resection. The superior mesenteric artery (SMA) margin of the specimen was tidily fixed around an artificial SMA as if in an in situ setting. In this prospective study, patients undergoing PD with PV resection for pancreatic cancer in 2016 were enrolled. To evaluate the feasibility of the three-dimensional fixation protocol, the SMA margin distance and PV involvement of tumor assessed by computed tomography (CT) were compared with those assessed by pathology. ResultsThirty-three patients with/without preoperative chemotherapy were enrolled. The entire cohort did not present with high-quality diagnostic assessment of the medial margins around SMA and PV (correct estimation, 58% and 73%, respectively). In contrast, in 16 patients undergoing upfront surgery, the concordance value of the SMA margin, which assesses the agreement between CT and pathology measures, was 0.48 (moderate agreement). The PV involvement examined by imaging was significantly associated with that by pathology (P = 0.013). ConclusionsThe three-dimensional fixation protocol was applicable to all cases undergoing PD with PV resection. Focusing on the patients with upfront surgery demonstrated the feasibility of accurate pathological assessment of medial margins. We propose this protocol as a promising standard for the assessment of true surgical margin status.

The importance of assessing the SMA margin in patients undergoing pancreaticoduodenectomy

Aim: The purpose of this study is to examine the true incidence of superior mesenteric artery (SMA) positivity in patients who have superior mesenteric vein (SMV) positivity while undergoing pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC). Methods: All patients who underwent PD for PDAC between January 2005 and December 2011 were retrospectively identified from our database. Patients deemed resectable by NCCN guidelines, protocol CT scans, and endoscopic ultrasound were included. The PD specimen was inked using five colors to specifically identify and study the SMV and SMA margins. We also analyzed and compared R1-sub groups (R1A group- SMA and SMV positive; R1B group - SMV positive, SMA negative). Results: 98 patients underwent PD for resectable pancreatic adenocarcinoma. 75 patients (76.5%) were found to have negative surgical margin on final pathology (R0 group) while 23 patients (23.4%) had positive SMV margins (R1 group). In the R1 group, 11 patients (47.8%) were found to have positive SMA margin (R1A group) and 12 patients were SMV positive and SMA negative (R1B group). No statistically significant survival difference was noted between R0 and R1 or between R1-A and R1-B. Conclusion: This study demonstrates that with careful inking of the SMA and SMV margins, there is a high rate of concurrent SMA positivity in those patients that are SMV positive. There was no impact on survival. Accurate margin assessment is critical by careful examination and inking of the SMA and SMV margin.

Diagnostic Performance of Computed Tomography in Predicting a Positive Circumferential Resection Margin for Resectable and Borderline Resectable Pancreatic Head Cancer

Introduction: To measure the diagnostic performance of computed tomography (CT) for the circumferential resection margin (CRM) status in patients with resectable and borderline resectable pancreatic head cancer. Method: We included 75 patients (37 females, mean age, 71 ± 11 years) who had a resectable and borderline resectable pancreatic head cancer and underwent upfront surgery. For the analysis, the CRM was subdivided into superior mesenteric artery (SMA), superior mesenteric vein/portal vein (SMV/PV) and posterior margins. Three abdominal radiologists retrospectively reviewed the preoperative CT images and evaluated CT resection margin status. The reference standard for the CRM status was pathologically made. A positive resection margin was defined as the presence of tumor cells within 1 mm of the CRM. The diagnostic performance of CT was measured for the overall CRM (per-patient analysis) and each of resection margin (per-margin analysis). We pooled the data across the radiologists using the generalized linear mixed model. Result: Thirty-eight patients were pathologically confirmed to have involved CRM. In per-patient analysis, the pooled sensitivity and specificity was 13.7% and 98.1%, respectively. In per-margin analysis, the pooled sensitivity and specificity for SMA margin was 12.4% and 98.1%, respectively; for posterior margin, 10.3% and 99.4%, respectively; for SMV/PV, 26.9% and 96.3%, respectively. Conclusion: Very low sensitivity and high specificity of CT in predicting a positive CRM suggests that CT has poor performance to select patients who would benefit from neoadjuvant therapy rather than upfront surgery in patients with resectable and borderline resectable pancreatic head cancer.

Tumour origin and R1 rates in pancreatic resections: towards consilience in pathology reporting.

To evaluate differences in the R1 rates of ampullary (AC), pancreatic (PC), and distal bile duct (DBD) cancers in pancreatoduodenectomies (PD) using standardised pathology assessment. Data of PD (2010-2011) analysed in accordance with the Royal College of Pathologists (UK) protocol, were retrieved. Clinicopathologic features, including frequency, topography, and mode of margin involvement in AC (n = 87), PC (n = 18), and DBD (n = 5) cancers were evaluated. The R1 rate was 7%, 67%, and 20% in the AC, PC, and DBD cancers (p < 0.001). Within the PC cohort, R1 rate was heterogeneous (chemo-naïve, 77%; post-neoadjuvant, 40%). Commonest involved margins were as follows: posterior in overall PD (35%), AC (43%), overall PC (33%), and post-neoadjuvant PC (100%); superior mesenteric artery margin in chemo-naïve PC (38%) and common bile duct margin in DBD (100%) cancers. In AC, majority (66%) of R1 were signet ring cell type. Indirect margin involvement due to tumour within lymph node, perineural sheath or lymphovascular space was observed in 26% cases, and altered R1 rate in AC, PC, and DBD cohorts by 1%, 12%, and 0%, respectively. Although not statistically significant, patients with R1 had lower disease-free survival than those with R0 (mean, 25.4months versus 44.4months). Tumour origin impacts R1 data in PD necessitating its accurate classification by pathologists. Indirect involvement, histology, and neoadjuvant therapy influence the R1 rate, albeit in a minority of cases. Generating cogent R1 data based on standardised pathology reporting is the foremost need of the hour.

Multicolour versus monocolour inking specimens after pancreaticoduodenectomy for periampullary cancer: A single centre prospective randomised clinical trial

BackgroundR status represents an important prognostic factors in periampullary cancers. Thus, it is useful to verify if it can be influenced by different techniques of margination. MethodsSingle-centre, randomised clinical trial of patients affected by periampullary cancer who underwent pancreaticoduodenectomies which included two different types of margination: arm A (multicolour inking) and arm B (monocolour inking). The primary endpoint was the overall R1 resection rate and its difference between the two arms. The secondary endpoints were the R1 resection rate in each margin and its difference between the two arms, and the impact of margin status on survival. ResultsFifty patients were randomised, 41 analysed: 22 in arm A, 19 arm B. The overall R1 status was 61%, without significant differences between the two arms. The margin most commonly involved was the superior mesenteric artery (SMA) (36.6%). A trend in favour of arm B was shown for the superior mesenteric artery margin (arm A = 22.7% versus arm B = 52.6%; P = 0.060). The anterior surface (P = 0.015), SMA (P = 0.047) and pancreatic remnant (P = 0.018) margins significantly influenced disease-free survival. ConclusionsThe R status was not influenced by different techniques of margination using a standardised pathological protocol. The SMA margin seemed to be the most important margin for evaluating both R status and disease-free survival.

Vein resection in patients with adenocarcinoma of the head of pancreas adherent to the portomesenteric venous axis is beneficial despite a high rate of R1 resection

Backgrounds/AimsEn-bloc vein resection (VR) for pancreatic ductal adenocarcinoma (PDAC) of the head of pancreas adherent to the portomesenteric axis benefits patients when the vein wall is not infiltrated by tumour and an R0 resection is achieved, albeit at the expense of greater morbidity and mortality.MethodsA retrospective review of pancreaticoduodenectomy for PDAC over 6 years was conducted. Patients were divided into a standard resection group (Group SR) and simultaneous vein resection group (Group VR) and compared for outcome.ResultsThe study group consisted of 41 patients (Group SR 15, Group VR 26). VR was performed by end-to-end reconstruction in 12 patients and with interposition grafts in 13 cases (autologous vein in 10, PTFE in 3). R1 resections occurred in 49% patients, with the superior mesenteric artery margin most commonly involved. Patients with Ishikawa grade III and IV vein involvement were more likely to carry a positive SMA margin (p=0.04). Involvement of the splenoportal junction was associated with a significantly greater risk of pancreatic transection margin involvement. No difference in morbidity was seen between the groups. Median survival in the entire group of patients was 17 months and did not vary significantly between the groups. The only significant predictor of survival was lymph node status.ConclusionsVenous involvement by proximal PDAC is indicative of tumor location rather than tumor biology. VR improves outcomes in patients with tumor adhesion to the portomesenteric venous axis despite a high incidence of R1 resections and greater operative mortality.

Technique of “mini-invasive radical antegrade modular pancreatosplenectomy” for pancreatic cancer

Pancreatic cancer spreads preferentially into the retroportal lamina that is frequently invaded at the celiac trunk (CT) and/or superior mesenteric artery (SMA) margins. In 2007, for the first time, it has been proposed by the team of Prof. Strasberg SM an innovative surgical technique for open surgery called radical antegrade modular pancreatosplenectomy (RAMPS) which allows to increase the circumferential resection margins in case of pancreatic cancer of the body of the pancreas and it is associated to a high rate of R0 resection. Currently, it is possible to perform such intervention mini-invasively. The present manuscript reports our technique.