Anatomy of the neural fibers at the superior mesenteric artery-a cadaver study

Two Cases of Refractory Diarrhea Subsequent to Vascular Reconstruction for Infective Superior Mesenteric Artery Aneurysms

Superior mesenteric artery (SMA) aneurysm and their surgical interventions are rare, leading to infrequent reports of postoperative complications. This report describes 2 cases of refractory diarrhea following vascular reconstruction for infectious SMA aneurysms. Both patients underwent aneurysm resection and SMA reconstruction but experienced persistent diarrhea despite treatment with anti-diarrheal medications. Postoperative diarrhea, a complication observed after resection of the nerve plexus around the SMA in gastrointestinal surgery, may be attributed to intraoperative injury to the nerve plexus in our cases. Though palliative therapy is partially effective, more efficacious management strategies are desirable to address this persistent complication.

Stapled Arterial Divestment in Surgery for Locally Advanced Pancreatic Cancer

BACKGROUND

Pancreatic adenocarcinoma has a predisposition to invade the neural tissue surrounding the superior mesenteric artery (SMA). Before the advent of neoadjuvant chemotherapy (NAC), any invasion of this tissue was often considered as unresectable disease. Currently, patients who respond favourably to NAC have potentially resectable disease. There is debate over the exact technique of removing this shell of tumour tissue surrounding the SMA, and whether it is comparable to arterial resection and reconstruction.

METHODS

We describe a technique of en bloc arterial divestment in which an endovascular stapler combined with sharp dissection is used to divide the shell of periadventitial SMA tissue.

CONCLUSIONS

In patients with locally advanced disease, the technique of arterial divestment can be safely performed where the tumour is not invading below the external elastic lamina. This allows complete tumour resection without incurring the higher morbidity and mortality associated with SMA resection.

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

BACKGROUND

The 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.

METHODS

Clinical 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).

RESULTS

Following 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.

CONCLUSION

In 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.

Feasibility of laparoscopic versus open pancreatoduodenectomy following neoadjuvant chemotherapy for borderline resectable pancreatic cancer: a retrospective cohort study

BACKGROUND

There is no evidence supporting the feasibility of laparoscopic pancreaticoduodenectomy (LPD) compared to open pancreatoduodenectomy (OPD) following neoadjuvant chemotherapy (NACT) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

The clinical data of consecutive patients with borderline resectable PDAC who received NACT and underwent either LPD or OPD between January 2020 and December 2022 at Fudan University Shanghai Cancer Center was prospectively collected and retrospectively analyzed.

RESULTS

The analysis included 57 patients in the OPD group and 20 in the LPD group. Following NACT, the LPD group exhibited a higher median CA19-9 decrease rate compared to the OPD group (85.3% vs. 66.9%, P = 0.042). Furthermore, 3 anatomically borderline PDACs in the LPD group and 5 in the OPD group were downstaged into resectable status (30.0% vs. 12.3%, P = 0.069). According to RECIST criteria, 51 (66.2%) patients in the entire cohort were evaluated as having stable disease. The median operation time for the LPD group was longer than the OPD group (419 vs. 325 min, P < 0.001), while the venous resection rate was 35.0% vs. 43.9%, respectively (P = 0.489). There was no difference in the number of retrieved lymph nodes, with a median number of 18.5 in the LPD group and 22 in the OPD group, and the R1 margin rate (15.0% vs. 12.3%) was also comparable. The incidence of Clavien-Dindo complications (35.0% vs. 66.7%, P = 0.018) was lower in the LPD group compared to the OPD group. Multivariable regression analysis revealed that a tumor diameter > 3 cm before NACT (HR 2.185) and poor tumor differentiation (HR 1.805) were independent risk factors for recurrence-free survival, and a decrease rate of CA19-9 > 70% (OR 0.309) was a protective factor for early tumor recurrence and overall survival.

CONCLUSIONS

LPD for PDAC following NACT is feasible and oncologically equivalent to OPD. Effective control of CA19-9 levels is beneficial in reducing early tumor recurrence and improving overall survival.

Prognostic significance of margin clearance in pancreaticoduodenectomy specimens with pancreatic ductal adenocarcinoma in a Danish population-based nationwide study

BACKGROUND

In this nationwide population-based cohort study, we investigated the overall minimum margin width that is independently associated with improved survival following pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) and evaluated whether certain margins or surfaces hold independent prognostic significance.

METHODS

Data from 367 patients who underwent PD for PDAC in the period 2015-2019 were retrieved from the Danish Pancreatic Cancer Database. Missing data were obtained by review of pathology reports and re-microscopy of resection specimens. Surgical specimens were evaluated using a standardised pathological protocol involving multicolour inking, axial slicing and exact reporting of circumferential margin clearances in 0.5 mm increments.

RESULTS

When categorised according to margin widths of <0.5, <1.0, <1.5, <2.0, <2.5 and <3.0 mm, R1 resections were detected in 34%, 57%, 75%, 78%, 86% and 87% of cases, respectively. In multivariable analyses, an overall margin clearance of ≥1.5 mm was associated with improved survival compared with a clearance of <1.5 mm (HR 0.70 95% CI 0.51-0.97 (p = 0.031)). When evaluating the margins separately, no margin had independent prognostic significance.

CONCLUSION

Margin clearance of at least 1.5 mm was independently associated with improved survival following PD for PDAC.

Prognostic Impact of Resection Margin Status on Distal Pancreatectomy for Ductal Adenocarcinoma

Pancreatic cancer is associated with a poor prognosis. While surgical resection is the only treatment option with curative intent, most patients die of locoregional and/or distant recurrence. The prognostic impact of the resection margin status has received much attention. However, the evidence is almost exclusively related to pancreatoduodenectomies, while corresponding data for distal pancreatectomy specimens are limited. The key data, such as the rate of microscopic margin involvement (“R1”), the site of margin involvement, and the impact of R1 on patient outcome, are divergent between studies and do not currently allow any general conclusions. The main reasons for the variability in the published data are the small size of the study cohorts and their heterogeneity, as well as the marked divergence in pathology examination practices. The latter is a consequence of the lack of concrete guidance, both for grossing and microscopic examination. The increasing administration of neoadjuvant chemo(radio)therapy introduces a further factor of uncertainty as the conventional definition of a tumour-free margin (“R0”) based on 1 mm clearance is inadequate for these specimens. This review discusses the published data regarding the prognostic impact of margin status in distal pancreatectomy specimens along with the challenges and uncertainties that are related to the assessment of the margins.