Identification of the lymphatic drainage pathways from the pancreatic head guided by indocyanine green fluorescence imaging during pancreaticoduodenectomy

Self-assembled nanomicelles for oral delivery of luteolin utilizing the intestinal lymphatic pathway to target pancreatic cancer

Pancreatic cancer is one of the major cause of cancer-related deaths worldwide, and is mainly associated with carcinomas of the pancreatic tissue. Current therapies for treating pancreatic cancer have a major drawback related to their low bioavailability and non-specificity, which leads to low therapeutic efficacy and side effects. Luteolin (LUT) has been clinically used for treatment of various types of cancer, although its clinical use has declined owing to its low oral bioavailability. In this work, we prepared an effervescent-based nanocarrier (NG) that rapidly triggers an effervescent reaction and transforms into nanomicelles to modulate the oral bioavailability of the hydrophobic drug Luteolin (LUT). Furthermore, we performed tests to assess its in vitro epithelial cell permeability and cellular internalization on a Caco-2 monolayer. We also performed in vivo toxicity assessment using animal models. Further, we evaluated the nanocarrier system's in vivo efficacy in tumor xenograft pancreatic cancer models. We validated that being pH responsive, our effervescent carrier disassembles at intestinal pH and is absorbed through the intestinal lymphatic system (ILS) to further site-specifically invade the pancreatic cancer cells. Furthermore, the negative surface charge and particle size (450 ± 100 nm) of the nanomicelles helped to internalize LUT through the ILS. We observed that LUT-loaded nanomicelles have significant antipancreatic cancer efficacy by activating caspase-3 activity and downregulating VEGF-A, FAK, TNF-α, and Ki-67. Unlike other drug-delivery systems, we developed noninvasive nanocarrier system has the capability of transporting the hydrophobic drug LUT from the intestine to the tumor site by utilizing the ILS.

The preliminary analysis of lymphatic flow around the connective tissues surrounding SMA and SpA elucidates patients' oncological condition in borderline-resectable pancreatic cancer

BACKGROUND

In pancreatic ductal adenocarcinoma (PDAC), invasion of connective tissues surrounding major arteries is a crucial prognostic factor after radical resection. However, why the connective tissues invasion is associated with poor prognosis is not well understood.

MATERIALS AND METHODS

From 2018 to 2020, 25 patients receiving radical surgery for PDAC in our institute were enrolled. HyperEye Medical System (HEMS) was used to examine lymphatic flow from the connective tissues surrounding SMA and SpA and which lymph nodes ICG accumulated in was examined.

RESULTS

HEMS imaging revealed ICG was transported down to the paraaortic area of the abdominal aorta along SMA. In pancreatic head cancer, 9 paraaortic lymph nodes among 14 (64.3%) were ICG positive, higher positivity than LN#15 (25.0%) or LN#18 (50.0%), indicating lymphatic flow around the SMA was leading directly to the paraaortic lymph nodes. Similarly, in pancreatic body and tail cancer, the percentage of ICG-positive LN #16a2 was very high, as was that of #8a, although that of #7 was only 42.9%.

CONCLUSIONS

Our preliminary result indicated that the lymphatic flow along the connective tissues surrounding major arteries could be helpful in understanding metastasis and improving prognosis in BR-A pancreatic cancer.

Indocyanine green: The guide to safer and more effective surgery

In this editorial we comment on the article by Kalayarasan and co-workers published in the recent issue of the World Journal of Gastrointestinal Surgery. The authors present an interesting review on the use of indocyanine green fluorescence in different aspects of abdominal surgery. They also highlight future perspectives of the use of indocyanine green in mini-invasive surgery. Indocyanine green, used for fluorescence imaging, has been approved by the Food and Drug Administration and is safe for use in humans. It can be administered intravenously or intra-arterially. Since its advent, there have been several advancements in the applications of indocyanine green, especially in the surgical field, such as intraoperative mapping and biopsy of sentinel lymph node, measurement of hepatic function prior to resection, in neurosurgical cases to detect vascular anomalies, in cardiovascular cases for patency and assessment of vascular abnormalities, in predicting healing following amputations, in helping visualization of hepatobiliary anatomy and blood vessels, in reconstructive surgery, to assess flap viability and for the evaluation of tissue perfusion following major trauma and burns. For these reasons, the intraoperative use of indocyanine green has become common in a variety of surgical specialties and transplant surgery. Colorectal surgery has just lately begun to adopt this technique, particularly for perfusion visualization to prevent anastomotic leakage. The regular use of indocyanine green coupled with fluorescence angiography has recently been proposed as a feasible tool to help improve patient outcomes. Using the best available data, it has been shown that routine use of indocyanine green in colorectal surgery reduces the rates of anastomotic leak. The use of indocyanine green is proven to be safe, feasible, and effective in both elective and emergency scenarios. However, additional robust evidence from larger-scale, high-quality studies is essential before incorporating indocyanine green guided surgery into standard practice.

Pancreatic draining lymph nodes (PLNs) serve as a pathogenic hub contributing to the development of type 1 diabetes

Type 1 diabetes (T1D) is a chronic, progressive autoinflammatory disorder resulting from the breakdown of self-tolerance and unrestrained β cell-reactive immune response. Activation of immune cells is initiated in islet and amplified in lymphoid tissues, especially those pancreatic draining lymph nodes (PLNs). The knowledge of PLNs as the hub of aberrant immune response is continuously being replenished and renewed. Here we provide a PLN-centered view of T1D pathogenesis and emphasize that PLNs integrate signal inputs from the pancreas, gut, viral infection or peripheral circulation, undergo immune remodeling within the local microenvironment and export effector cell components into pancreas to affect T1D progression. In accordance, we suggest that T1D intervention can be implemented by three major ways: cutting off the signal inputs into PLNs (reduce inflammatory β cell damage, enhance gut integrity and control pathogenic viral infections), modulating the immune activation status of PLNs and blocking the outputs of PLNs towards pancreatic islets. Given the dynamic and complex nature of T1D etiology, the corresponding intervention strategy is thus required to be comprehensive to ensure optimal therapeutic efficacy.

Impact of para aortic lymph node removal on survival following resection for pancreatic adenocarcinoma

INTRODUCTION

For PDAC patients undergoing resection, it remains unclear whether metastases to the paraaortic lymph nodes (PALN+) have any prognostic significance and whether metastases should lead to the operation not being carried out. Our hypothesis is that PALN + status would be associated with short overall survival (OS) compared with PALN-, but longer OS compared with patients undergoing surgical exploration only (EXP).

METHODS

Patients with registered PALN removal from the nationwide Danish Pancreatic Cancer Database (DPCD) from May 1st 2011 to December 31st 2020 were assessed. A cohort of PDAC patients who only had explorative laparotomy due to non-resectable tumors were also included (EXP group). Survival analysis between groups were performed with cox-regression in a multivariate approach including relevant confounders.

RESULTS

A total of 1758 patients were assessed, including 424 (24.1%) patients who only underwent explorative surgery leaving 1334 (75.8%) patients for further assessment. Of these 158 patients (11.8%) had selective PALN removal, of whom 19 patients (12.0%) had PALN+. Survival analyses indicated that explorative surgery was associated with significantly shorter OS compared with resection and PALN + status (Hazard Ratio 2.36, p < 0.001). No difference between PALN + and PALN- status could be demonstrated in resected patients after controlling for confounders.

CONCLUSION

PALN + status in patients undergoing resection offer improved survival compared with EXP. PALN + should not be seen as a contraindication for curative intended resection.

The Impact of Additional Para-aortic Dissection During Pancreaticoduodenectomy for Resectable Pancreatic Cancer

BACKGROUND

The short-term outcome and long-term survival of pancreaticoduodenectomy with additional para-aortic dissection (PAD) for patients with resectable pancreatic cancer remain obscure.

PATIENTS AND METHODS

Consecutive patients who underwent radical pancreaticoduodenectomy for resectable pancreatic cancer in a single high-volume center during a 7-year period were included retrospectively. Both short- and long-term effects of PAD were compared between the PAD group and the no PAD group. Then, the PAD group was divided into the non-metastatic para-aortic lymph node (PALN-) group and the metastatic PALN (PALN+) group to further analyze the prognosis of PALN+.

RESULTS

Of the 909 included patients, 280 (30.8%) underwent PAD during pancreaticoduodenectomy. The PAD group had a higher rate of intra-abdominal infection compared with the no PAD group (28.6% vs. 20.7%, P = 0.009) but no differences were found in the incidence of other complications. The overall survival (OS) and recurrence-free survival (RFS) were also comparable between the two groups. Subgroup analysis showed that patients with PALN+ had a worse OS than patients in the PALN- group (median of 14 vs. 20 months, P = 0.048). Multivariate Cox regression analysis further revealed that PALN+ was an independent adverse predictor of OS (hazard ratio: 1.70, P = 0.007).

CONCLUSIONS

This study suggests that the addition of PAD during pancreaticoduodenectomy does not improve the prognosis of patients with resectable pancreatic cancer and may lead to an increased risk of infection. However, the accurate preoperative assessment and appropriate treatment strategy for patients with PALN+ need further investigation due to the poor prognosis.

Prognostic impact of para-aortic lymph node status in resected pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous neoplasm - Time to consider a reclassification?

BACKGROUND

Para-aortic lymph node (PALN) metastases in pancreatic ductal adenocarcinoma (PDAC) correlates with poor prognosis. The role of PALN in invasive intraductal papillary mucinous neoplasms (inv-IPMN) has not been well explored. The present study investigated the rate of metastatic PALN, lymph node ratio (LNR) and the overall nodal (N) status as prognostic factors in PDAC and inv-IPMN.

METHODS

This consecutive single-center series included patients with PDAC or inv-IPMN in the pancreatic head who underwent pancreatoduodenectomy or total pancreatectomy, including PALN resection between 2009 and 2018. Median overall survival (mOS) and impact of clinicopathological factors, including PALN status on survival, were evaluated.

RESULTS

403 patients were included, 314 had PDAC and 89 inv-IPMN. PALN were metastatic in 16% of PDAC and 17% of inv-IPMN. N0 status was present in 6% of the patients with PDAC and 16% of inv-IPMN patients (p = 0.007). LNR >15% was more common in PDAC (52%) than in inv-IPMN (34%) (p = 0.004). mOS was 12.7 months in the presence of PALN metastases and 22.7 months without (p < 0.0001). Age >70 years, CA19-9 >200 U/mL, PDAC and N2 status were significantly associated with worse survival in a multivariable analysis. PALN status and LNR were not independent prognostic factors. In N2 status mOS was similar regardless the presence of PALN metastases.

CONCLUSION

The frequency of PALN metastases was similar in PDAC and inv-IPMN. Although PALN positive status entailed a shorter mOS, it was not an independent risk factor for death, and did not influence survival in N2-staged disease. The M1-status for PALN positivity may need reconsideration.

Complete circumferential lymphadenectomy around the superior mesenteric artery with preservation of nerve plexus reduces locoregional recurrence after pancreatoduodenectomy for resectable pancreatic ductal adenocarcinoma

BACKGROUND

Evaluation of recurrence pattern and risk factors for recurrence are essential for good rates of survival after upfront pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included 167 consecutive patients who underwent upfront PD for resectable PDAC between 2000 and 2018. Postoperative recurrences were classified into three patterns according to initial recurrence site: isolated locoregional, isolated distant, and simultaneous locoregional and distant recurrences.

RESULTS

This study found 114 patients who developed postoperative recurrence (68.3%), including 37 patients with isolated locoregional recurrence (32.5%), 67 patients with isolated distant recurrence (58.8%), and 10 patients with simultaneous locoregional and distant recurrences (6.0%). When locoregional recurrence was classified based on the location of recurrent lesions, locoregional recurrence most commonly occurred around the superior mesenteric artery (SMA) (70.2%), followed by around the hepatic artery (25.5%) and in the paraaortic region (14.9%). Multivariate analyses showed that complete circumferential lymphadenectomy around the SMA, including not only the right side, but also the left side, was an independent factor for reduction of locoregional recurrence (P = 0.019, odds ratio [OR]: 2.217). Lymph node metastasis was an independent risk factor for both locoregional (P < 0.001, OR: 3.686) and distant recurrences (P < 0.001, OR: 4.315). Non-completion of postoperative adjuvant therapy was a risk factor for distant recurrence (P < 0.001, OR: 3.748).

CONCLUSION

Based on our data, complete circumferential lymphadenectomy around the SMA might contribute to local control, and multidisciplinary treatment including neoadjuvant therapy might be needed for resectable PDAC with high risk for recurrence.

Survival in resectable pancreatic ductal adenocarcinoma with para-aortic lymph node dissection: A retrospective study in Vietnamese population

Background

Pancreatic ductal adenocarcinoma (PDAC) has a high recurrence rate and poor outcome. Lymph node (LN) metastasis, especially para-aortic LN (PALN), is an important prognostic factor. PALN assessment through sampling with frozen-section analysis is a validated method. Our aim was to evaluate the prognostic impact of PALN on overall survival (OS) in patients who underwent standard pancreaticoduodenectomy, lymphadenectomy with PALN sampling, as well as to identify other prognostic factors for survival.

Methods

Our retrospective study included 89 PDAC patients undergoing radical resection with PALN sampling. The patients were classified into PALN(+) (n = 11) and PALN(-) (n = 78). Univariate and multivariate analyses of 1-year and 3-year OS and Kaplan-Meier model were used.

Results

OS after 1-year for PALN(+) and PALN(-) was 18.2 and 56.4%, after 3-year was 15.4% and 0%, respectively. Tumor differentiation, LN metastasis (LN(-), LN(+) PALN(-), LN(+) PALN(+)) were significant prognostic factors in both univariate and multivariate analyses for 1-year OS, and neural invasion (PN) was the solely significant factor for 3-year OS (p < 0.05). Kaplan-Meier estimate showed that OS of PALN(+) and PN (+) was significantly lower than the negative group, respectively (p < 0.05). No statistical difference in OS was seen between LN(-) and LN(+) PALN(-); and between LN(+) PALN(-) and PALN(+) (p = 0.107). Patients with PN (-) PALN(+) had similar OS compared to PN (+) PALN(-) (p > 0.05).

Conclusion

PDAC had a poor outcome despite treatment with radical resection. Further follow-up should be conducted to determine the role of surgery in PALN(+)and PN invasion.

Opportunities and delusions regarding drug delivery targeting pancreatic cancer-associated fibroblasts

A dense desmoplastic stroma formed by abundant extracellular matrix and stromal cells, including cancer-associated fibroblasts (CAFs) and immune cells, is a feature of pancreatic ductal adenocarcinoma (PDAC), one of the most lethal cancer types. As the dominant cellular component of the PDAC stroma, CAFs orchestrate intensive and biologically diverse crosstalk with pancreatic cancer cells and immune cells and contribute to a unique PDAC tumor microenvironment promoting cancer proliferation, metastasis, and resistance against both chemo- and immunotherapies. Therefore, CAFs and CAF-related mechanisms have emerged as promising targets for PDAC therapy. However, several clinical setbacks and accumulating knowledge of the PDAC stroma have revealed the heterogeneity and multifaceted biological roles of CAFs, and concerns regarding "what to deliver" and "how to deliver" have arisen when designing CAF-targeted drug delivery systems to specifically inhibit tumor-supporting CAFs without impairing tumor-restricting CAFs. In this review, we will discuss the complexity of CAFs in the PDAC stroma as well as the potential opportunities and common misconceptions regarding drug delivery efforts targeting PDAC CAFs.

Optimal Lymphadenectomy of the Mesopancreas Based on Fluorescence Imaging During Pancreaticoduodenectomy

BACKGROUND

Excision of the mesopancreas with lymphadenectomy is an important component of pancreatoduodenectomy. However, the optimal extent of lymphadenectomy remains unclear. Furthermore, accurate description of the mesopancreatic lymphatic pathways is difficult, probably because of the complex anatomy. Intestinal derotation simplifies the anatomy and facilitates both examination of lymphatic flow and the surgical procedure. The aim of this study was to evaluate lymphatic flow in the mesopancreas using indocyanine green fluorescence imaging with an intestinal derotation technique, and to clarify the optimal extent of mesopancreas excision and lymphadenectomy in pancreatoduodenectomy.

METHODS

Indocyanine green solution (2.5 × 10^-3 mg) was injected into the pancreatic head parenchyma. After intestinal derotation, the spread of indocyanine green was observed using near-infrared imaging.

RESULTS

Participants comprised 10 patients who underwent pancreatoduodenectomy for periampullary neoplasms. With indocyanine green fluorescence imaging, 9 of the 10 patients showed lymphatic flow from the pancreatic head to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery (but not via the second and more distant arteries), with eventual drainage into the paraaortic region.

CONCLUSIONS

Lymphatic pathways from the pancreatic head were connected to the superior mesenteric artery via the inferior pancreaticoduodenal artery and first jejunal artery. Excision of the mesopancreas with the inferior pancreaticoduodenal artery and first jejunal artery while preserving the second or more distant arteries appears optimal in pancreatoduodenectomy for periampullary malignancies.

Complete Lymphadenectomy Around the Entire Superior Mesenteric Artery Improves Survival in Artery-First Approach Pancreatoduodenectomy for T3 Pancreatic Ductal Adenocarcinoma

BACKGROUND

Artery-first approach pancreatoduodenectomy (AFA-PD) is an important technique for treating pancreatic ductal adenocarcinoma (PDAC). However, it remains unknown whether performing complete lymphadenectomy around the entire superior mesenteric artery (SMA) is associated with better outcomes. In this retrospective study, we aimed to investigate whether this approach improved overall and recurrence-free survival in patients with PDAC.

METHODS

We identified 88 patients with T3 PDAC who underwent PD at St. Marianna University School of Medicine, Kawasaki, Japan, between April 2005 and October 2017. Two groups were defined: an "AFA-PD group" (n = 45) who had undergone AFA-PD in addition to complete lymphadenectomy around the entire SMA, and a "conventional PD group" (n = 43) in whom complete lymphadenectomy had not been performed (conventional group). Univariate and multivariate survival analyses were performed to identify risk factors for overall and disease-free survival.

RESULTS

The AFA-PD group had a longer median survival time (40.3 vs. 22.6 months; p = 0.0140) and a higher 5-year survival rate (40.3% vs. 5.9%, p = 0.005) than the conventional PD group. Multivariate analysis showed that AFA-PD with complete lymphadenectomy around the entire SMA was an independent factor for improved overall survival (p = 0.022). Recurrences around the SMA were significantly less frequent in the AFA-PD group than in the conventional group (22.2% vs. 44.2%, p = 0.041).

CONCLUSIONS

AFA-PD with complete lymphadenectomy around the entire SMA can prevent recurrences around the SMA and may prolong overall survival in patients with PDAC.

Prognostic Impact of Paraaortic Lymph Node Metastasis in Extrahepatic Cholangiocarcinoma

BACKGROUND

Surgical resection in patients with extrahepatic cholangiocarcinoma (EHCC) with paraaortic lymph node metastasis (PALNM) remains controversial. The objective of this study was to investigate the prognostic impact of PALNM in resected EHCC.

METHODS

The present retrospective study included 410 patients, including 16 patients with PALNM, who underwent surgical resection of EHCC between September 2002 and December 2018. These were compared to 9 patients in whom EHCC was not resected due to PALNM. The clinicopathological features and survival outcomes were investigated to identify the prognostic factors in resected EHCC.

RESULTS

The overall survival in the resected patients with PALNM was significantly better than that in unresected patients (median survival time [MST] 33.7 vs. 16.7 months, p=0.009) and was not significantly worse than that of patients with regional lymph node metastasis (LNM) (MST 33.7 vs 36.0 months, p=0.278). The multivariate analysis identified age > 70 years, male sex, tumor location (perihilar), residual tumor status, histological grade, microscopic venous invasion, and regional LNM as independent prognostic factors.

CONCLUSIONS

There was no significant difference in survival between the resected patients with PALNM and patients with regional LNM, and PALNM was not a significant prognostic factor in the multivariate analysis. Surgical resection may be considered an acceptable approach for EHCC with PALNM in selected patients.

The accuracy of sentinel node biopsy by 99mTc-sodium phytate in patients with pancreatic cancer

Backgrounds/Aims

Pancreaticoduodenectomy is the only potentially curative treatment for pancreatic cancer. The identification of the first nodal drainage site (sentinel node) may improve the detection of metastatic nodes and can contribute to a less invasive surgery. We aimed to determine the accuracy of sentinel node mapping in patients with pancreatic cancer using intraoperative radiotracer injection technique.

Methods

At surgical exposure, peritumoral injection of 0.4-0.5 mci/0.5 ml of 99mTc- sodium phytate was performed. After tumor resection, sentinel nodes were investigated in the most common areas using a hand-held gamma probe. Any lymph node with in vivo count twice the background was considered as sentinel node, thus, it was removed and sent for pathological assessment. Then a standard lymph node dissection was performed for all patients.

Results

Fourteen patients with cancer in the head of the pancreas were included in this study. Overall, 180 lymph nodes were harvested with a mean of 11.6±4.7 lymph nodes per patient. In eight patients, at least one sentinel node could be identified (detection rate about 64%). False negative rate of the study was 3/5 (60%).

Conclusions

Our study revealed insufficient diagnostic accuracy and high false negative rate for sentinel lymph node mapping with 99mTc- sodium phytate in pancreatic cancer.

Gastrocolic trunk of Henle and its variants: review of the literature and clinical relevance in colectomy for right-sided colon cancer

PURPOSE

Venous vascular anatomy of the right colon presents a high degree of variability. Henle's Gastrocolic Trunk is considered an important anatomical landmark by colorectal surgeons. The classical description concerns a bipod vascular structure or tripod, but several variants are associated to it. The aim of this study is to merge the most updated literature on the anatomy knowledge of the Gastrocolic Trunk by evaluating all possible variants, as well as to underline its surgical importance due to its topographical relationships.

METHODS

Twelve studies describing the anatomy of the gastrocolic trunk were selected, each of them dealing with a more or less extensive series of cases. A distinction was drawn between the gastropancreatic trunk, devoid of the colonic component, and the gastrocolic trunk; and then the frequency of the different resulting variants was reported. The data obtained from cadavers and radiological studies were analyzed separately.

RESULTS

The Gastrocolic Trunk is found in 74% of cadaver studies, and in 86% of radiological studies. Its most frequent configuration is represented by the union of right gastroepiploic vein + anterior superior pancreaticoduodenal vein + superior right colic vein, respectively, 32.5% and 42.5%, followed by the right colic vein which replaces (26.9%, 12.3%) or is added (10%, 20.1%) to the superior right colic vein.

CONCLUSIONS

The superior right colic vein joins the right gastroepiploic vein and the anterior superior pancreaticoduodenal vein thus forming, in most cases, the gastrocolic trunk. The anatomical knowledge of vascular structures forms the basis for both the interpretation of preoperative radiological images and the surgical procedure itself, despite the considerable anatomical variability of tributaries.

Pancreatic ductal adenocarcinoma and paraaortic lymph nodes metastases: The accuracy of intraoperative frozen section

BACKGROUND

Pancreatoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) with paraaortic lymph nodes metastases (PALN +) is associated with poor survival. Still, there are no current guidelines advocating systematic detection of PALN+.

METHODS

All consecutive patients who underwent surgical exploration/resection with concurrent paraaortic (group 16) lymphadenectomy for PDAC between 2009 and 2016 were considered for inclusion. Resection was systematically aborted in case of intraoperative PALN + detection. Diagnostic performance of preoperative imaging upon blind review and intraoperative PALN dissection with frozen section (FS) for PALN detection were evaluated. Additionally, the prognostic significance of PALN + on overall survival (OS) was analyzed.

RESULTS

Over the study period, among 129 patients undergoing surgery for PDAC, 113 had intraoperative PALN dissection with FS analysis. Median number of resected PALN was 3 (range, 1-15). Overall, PALN+ was found in 19 patients (16.8%). Upon blind review, preoperative imaging performed poorly for PALN + detection with a low agreement between imaging and final pathology (Kappa-Cohen index<0.2). In contrast, PALN FS showed high detection performances and strong agreement with final pathology (Kappa-Cohen index = 0.783, 95%CI 0.779-0.867, p < 0.001). Regarding survival outcomes, there was no difference between patients with PALN+ and patients not resected in the setting of liver metastases or locally unresectable disease found at exploration (p = 0.708).

CONCLUSIONS

Before PD for PDAC, intraoperative PALN dissection and FS analysis yields accurate PALN assessment and allows appropriate patient selection. This should be routinely performed and aborting resection should be strongly considered in case of PALN+.

Three-Dimensional Tumor Margin Demarcation Using the Hybrid Tracer Indocyanine Green-99mTc-Nanocolloid: A Proof-of-Concept Study in Tongue Cancer Patients Scheduled for Sentinel Node Biopsy

For radical resection of squamous cell carcinoma of the oral cavity, a tumor-free margin of at least 5 mm is required. Unfortunately, establishing in-depth margins is a surgical conundrum. Knowing that the hybrid sentinel node (SN) tracer indocyanine green (ICG)-^99mTc-nanocolloid generates temporary tattoolike markings at the site of administration, we studied the ability to apply this tracer for tumor margin demarcation combined with SN biopsy. Methods: Nineteen patients with clinical T1-T2 oral tongue tumors received the traditional superficial 3 or 4 deposits of ICG-^99mTc-nanocolloid (0.1 mL each), and in 12 patients additional deposits were placed deeply using ultrasound guidance (total of 6; 0.07 mL each). SN mapping was performed using lymphoscintigraphy and SPECT/CT. Before and directly after tumor excision, fluorescence imaging was performed to monitor the tracer deposits in the patient (fluorescent deposits were not used to guide the surgical excision). At pathologic examination, primary tumor samples were studied in detail. Results: The number of tracer depositions did not induce a significant difference in the number of SNs visualized (P = 0.836). Reproducible and deep tracer deposition proved to be challenging. The fluorescent nature of ICG-^99mTc-nanocolloid supported in vivo and ex vivo identification of the tracer deposits surrounding the tumor. Pathologic examination indicated that in 66.7% (8/12), all fluorescence was observed within the resection margins. Conclusion: This study indicates that tumor margin demarcation combined with SN identification has potential but that some practical challenges need to be overcome if this technique is to mature as a surgical guidance concept. Future studies need to define whether the technology can improve the radical nature of the resections.

Near infrared fluorescence light imaging for lymphatic flow toward para-aortic lymph node from the Calot's triangle: A prospective exploratory study

BACKGROUND

Metastasis to para-aortic lymph nodes (PAN) in hilar malignancies is considered distant metastasis. Fluorescence imaging using near infrared fluorescence light and indocyanine green (ICG-NIR imaging) are widely employed for identifying the sentinel lymph node, which might be an ideal alternative procedure for whole excisional biopsy of PAN. However, there has been no report about ICG-NIR imaging in hilar malignancies. The purpose of this study was to determine the optimal dose for indocyanine green to detect PAN and to reveal the detection rate of ICG-NIR imaging for lymphatic flow toward regional lymph nodes (RLN) or PAN from the Calot's triangle.

PATIENTS AND METHODS

We enrolled 62 patients with hepato-pancreatic-biliary malignancies in this study. The dose of ICG was optimized in the first 15 patients and the detection rate for RLN and PAN was evaluated in the remaining 47. We observed that the optimal administered dose of ICG for detecting fluorescent signals in PAN was 5 mg/mL.

RESULTS

Using this dose, RLN and PAN fluorescence were detected in 29 of 42 patients. Fluorescent signals were recorded in the lymph nodes (LN) along the bile duct and the posterior surface of the head of the pancreas. We also detected PAN fluorescent signals on the right side of the aorta around the left renal vein. We recommend 5 mg/ml of ICG to visualize lymphatic flow from the hepatoduodenal ligament to PAN using ICG-NIR imaging. However, because detection rate of RLN and PAN were 69%, respectively, further improvement for this procedure will be necessary for clinical application.

Indocyanine Green Perfusion Imaging-Guided Laparoscopic Pancreaticoduodenectomy: Potential Application in Retroperitoneal Margin Dissection

BACKGROUND

During laparoscopic pancreaticoduodenectomy (LPD), dissecting uncinate process from the superior mesenteric artery (SMA) will determine one of the important surgical margins (retroperitoneal margin) for predicting oncological outcomes and the quality of LPD. However, clear identification of the division line for retroperitoneal margin is not easy as the uncinate process of the pancreas is anatomically very close to SMA and intermingled with the nerve plexus and soft tissues around SMA. In this study, we present data regarding the potential usefulness of indocyanine green (ICG)-enhanced approach in obtaining retroperitoneal margin during LPD.

METHODS

From January to September 2017, medical records of patients who underwent LPD for periampullary pathological conditions were retrospectively reviewed. ICG (5 mg/2 cm³) was prepared and intravenously injected when dissecting uncinate process of the pancreas. Perioperative outcomes, including gender, age, diagnosis, body mass index, operation time, estimated blood loss, transfusion, presence of postoperative pancreatic fistulas (POPFs), and length of hospital stay, were evaluated.

RESULTS

During the study period, a total of 37 patients underwent LPD for periampullary pathological lesions. Among them, ICG-enhanced dissection of uncinate process of the pancreas was applied in 10 patients (27%). All patients were able to obtain margin-negative resection. There were no significant differences between the perioperative outcomes of patients who did and did not undergo ICG-enhanced approach.

DISCUSSION

ICG perfusion-based laparoscopic dissection of retroperitoneal margin is feasible and safe in LPD. This intraoperative visual difference can provide the surgeon with very helpful real-time visual information. Further study is mandatory.

Indocyanine green-based fluorescence imaging in visceral and hepatobiliary and pancreatic surgery: State of the art and future directions

In recent years, the use of fluorescence-guided surgery (FGS) to treat benign and malignant visceral, hepatobiliary and pancreatic neoplasms has significantly increased. FGS relies on the fluorescence signal emitted by injected substances (fluorophores) after being illuminated by ad hoc laser sources to help guide the surgical procedure and provide the surgeon with real-time visualization of the fluorescent structures of interest that would be otherwise invisible. This review surveys and discusses the most common and emerging clinical applications of indocyanine green (ICG)-based fluorescence in visceral, hepatobiliary and pancreatic surgery. The analysis, findings, and discussion presented here rely on the authors' significant experience with this technique in their medical institutions, an up-to-date review of the most relevant articles published on this topic between 2014 and 2018, and lengthy discussions with key opinion leaders in the field during recent conferences and congresses. For each application, the benefits and limitations of this technique, as well as applicable future directions, are described. The imaging of fluorescence emitted by ICG is a simple, fast, relatively inexpensive, and harmless tool with numerous different applications in surgery for both neoplasms and benign pathologies of the visceral and hepatobiliary systems. The ever-increasing availability of visual systems that can utilize this tool will transform some of these applications into the standard of care in the near future. Further studies are needed to evaluate the strengths and weaknesses of each application of ICG-based fluorescence imaging in abdominal surgery.

Which patients with para-aortic lymph node (LN16) metastasis will truly benefit from curative pancreaticoduodenectomy for pancreatic head cancer?

In patients with cancer of the pancreatic head, metastasis to para-aortic lymph nodes (LN16) is considered distant metastasis and a poor prognostic marker. However, the incidence of LN16 involvement in pancreatic head cancer is high, and it is unclear whether all such patients have poor surgical outcomes. We investigated the significance of LN16 involvement in resectable pancreatic head cancer by retrospectively analyzing 579 ductal adenocarcinoma patients treated with para-aortic lymph node dissection at two high-volume Chinese centers. Depending upon tumor location, the incidence of LN16 metastasis and the correlation between LN16 involvement and involvement of Group 1 or 2 lymph nodes significantly differed. Metastasis to LN16 indicated a high serum tumor burden and a poor prognosis, though LN16-positive patients with a lymph node ratio (LNR) < 0.25 may still benefit from radical surgery. Survival analysis of LN16-positive patients with resectable pancreatic head cancer revealed that tumor size, tumor differentiation, and tumor location are independent prognostic factors. We also found that preoperative serum CA125 < 18.62 U/ml and the level of JAK2 signaling are both indicators of who may benefit from curative surgical resection for pancreatic head cancer.

Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis

This review aimed to determine the overall sensitivity and specificity of indocyanine green (ICG) near-infrared (NIR) fluorescence in sentinel lymph node (SLN) detection in Colorectal cancer (CRC). A systematic search in electronic databases was conducted. Twelve studies including 248 patients were reviewed. The median sensitivity, specificity, and accuracy rates were 73.7, 100, and 75.7. The pooled sensitivity and specificity rates were 71% and 84.6%. In conclusion, ICG-NIR fluorescence is a promising technique for detecting SLNs in CRC.

Review and proposal of regional surgical management for melanoma: revisiting of integumentectomy and incontinuity dissection in treatment of skin melanoma

BACKGROUND

Past studies showed that integumentectomy and incontinuity could be effective procedures in the surgical management of melanoma patients. The present study reports on the historical background of these procedures. In addition, we analyze the ICG assisted integumentectomy and incontinuity techniques and algorithms that we had created when performing this procedure.

METHOD

In accordance with our algorithm, we performed ICG assisted integumentectomy/incontinuity procedures on 17 patients with stage III melanomas between 2008 and 2016. We also investigated the locoregional recurrence rate in a control group comprising 60 patients at stage III without using the algorithm.

RESULTS

The former group exhibited a tendency of locoregional recurrence rate suppression. Melanoma cells in the dissected intervening tissue were microscopically identified in 2 out of 17 cases.

CONCLUSIONS

Our ICG assisted integumentectomy or incontinuity procedures could be effective in controlling locoregional recurrence rates in melanoma cases. Moreover, our method can be generally applied because the dissection is only performed within the lymphatic pathway region identified using indocyanine green.

The use of near-infrared fluorescence imaging in endocrine surgical procedures

Near-infrared fluorescence imaging in endocrine surgery is a new, yet highly investigated area. It involves indocyanine green use as well as parathyroid autofluorescence. Several groups have described their technique and reported on the observed utility. However, there is no consensus on technical details. Furthermore, the correlation between intraoperative findings and postoperative outcomes is unclear. With this study, we aim to review the current literature on fluorescence imaging and share our insights on technical details.

Mesopancreas is a misnomer: time to correct the nomenclature

Focused pathological attention to tumor invasion of the retroperitoneal resection margin after pancreaticoduodenectomy for cancer of head of the pancreas led to the knowledge of strong tendency of cancer cells to infiltrate into the retropancreatic tissue and to spread along the peripancreatic neural plexuses as the cause of local recurrence. The term 'mesopancreas' was coined to describe perineural lymphatic layer located dorsally to the pancreas and it was suggested that its complete resection will minimize loco-regional recurrence and improve outcome. This catchy title and concept attracted the attention of surgeons and "total meso-pancreas excision" was introduced by 'artery first' or 'posterior first' surgical techniques to ensure 'en-bloc' extended resection of retropancreatic lymphatics. However, mesopancreas is a misnomer and cannot be called a 'true' mesentery as it does not have a fascial envelope attaching the pancreas to the posterior wall of the abdomen and does not contain 'all' its blood vessels and 'all' its primary draining lymphatics and lymph nodes. Japan Pancreas Society's description of pancreatic head plexus II is anatomically consistent with 'mesopancreas' and it should be renamed as such. This nomenclature clearly illustrates its exact anatomical location and surgical relevance; and stands up to necessary rigorous scientific scrutiny.

Prognostic value of lymph node metastases detected during surgical exploration for pancreatic or periampullary cancer: a systematic review and meta-analysis

BACKGROUND

Hepatic-artery and para-aortic lymph node metastases (LNM) may be detected during surgical exploration for pancreatic (PDAC) or periampullary cancer. Some surgeons will continue the resection while others abort the exploration.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library for studies investigating survival in patients with intra-operatively detected hepatic-artery or para-aortic LNM. Survival was stratified for node positive (N1) disease.

RESULTS

After screening 3088 studies, 13 studies with 2045 patients undergoing pancreatoduodenectomy were included. No study reported survival data after detection of LNM and aborted surgical exploration. In 110 patients with hepatic-artery LNM, median survival ranged between 7 and 17 months. Estimated pooled mean survival in 84 patients with hepatic-artery LNM was 15 [95%CI 12-18] months (13 months in PDAC), compared to 19 [16-22] months in 270 patients with N1-disease without hepatic-artery LNM (p = 0.020). In 192 patients with para-aortic LNM, median survival ranged between 5 and 32 months. Estimated pooled mean survival in 169 patients with para-aortic LNM was 13 [8-17] months (11 months in PDAC), compared to 17 (6-27) months in 506 patients with N1-disease without para-aortic LNM (p < 0.001). Data on the impact of (neo)adjuvant therapy on survival were lacking.

CONCLUSION

Survival after pancreatoduodenectomy in patients with intra-operatively detected hepatic-artery and especially para-aortic LNM is inferior to patients undergoing pancreatoduodenectomy with other N1 disease. It remains unclear what the consequence of this should be since data on (neo-)adjuvant therapy and survival after aborted exploration are lacking.

Anatomy of the transverse colon revisited with respect to complete mesocolic excision and possible pathways of aberrant lymphatic tumor spread

PURPOSE

Although lymph node metastases to pancreatic and gastroepiploic lymph node stations in transverse colon cancer have been described, the mode of lymphatic spread in this area remains unclear. This study was undertaken to describe possible pathways of aberrant lymphatic spread in the complex anatomic area of the proximal superior mesenteric artery and vein, the greater omentum, and the lower pancreatic border.

METHODS

Abdominal specimens obtained from four cadaveric donors were dissected according to the principles of complete mesocolic excision. The vascular architecture of the transverse colon was scrutinized in search of possible pathways of lymphatic spread to the pancreatic and gastroepiploic lymph nodes.

RESULTS

Vascular connections between the transverse colon and the greater omentum at the level of both the hepatic and the splenic flexures could be identified. In addition, small vessels running from the transverse mesocolon to the lower pancreatic border in the area between the middle colic artery and the inferior mesenteric vein were demonstrated. Moreover, venous tributaries to the gastrocolic trunk could be exposed to highlight its surgical importance as a guiding structure for complete mesocolic excision.

CONCLUSION

The technical feasibility to clearly separate embryologic compartments by predefined tissue planes in complete mesocolic excision was confirmed. However, the vicinity of all three endodermal intestinal segments (foregut, midgut, and hindgut) obviously gives way to vascular connections that might serve as potential pathways for lymphatic metastatic spread of transverse colon cancer.

The lymphatic system and pancreatic cancer

This review summarizes current knowledge of the biology, pathology and clinical understanding of lymphatic invasion and metastasis in pancreatic cancer. We discuss the clinical and biological consequences of lymphatic invasion and metastasis, including paraneoplastic effects on immune responses and consider the possible benefit of therapies to treat tumors that are localized to lymphatics. A review of current techniques and methods to study interactions between tumors and lymphatics is presented.

Incidence and prognostic impact of para-aortic lymph nodes metastases during pancreaticoduodenectomy for peri-ampullary cancer

BACKGROUND

Standard lymphadenectomy during pancreaticoduodenectomy (PD) for peri-ampullary cancer does not include the routine removal of para-aortic lymph nodes (PALN) (station 16, according to the JPS staging system). The aim of this study was to report the incidence and the prognostic value of PALN metastases in patients undergoing PD for peri-ampullary cancer.

MATERIALS AND METHODS

One hundred thirty-five consecutive patients who underwent PD and PALN dissection for peri-ampullary cancer were prospectively evaluated. The relationship between clinicopathological factors, including PALN metastases and survival was evaluated at univariate and multivariate analysis.

RESULTS

PALN metastases (N16+) were found in 11.1% of cases. At univariate analysis, R1 resection, metastatic nodes different from para aortic (N1) and N16+ significantly affected patients' prognosis. Compared with N16+, the median overall survival (OS) of N0 patients was significantly longer (32 versus 69 months, respectively; P < 0.05), whereas no difference was found between N16+ and N1 patients (32 versus 34 months, respectively) (P > 0.05). At multivariate analysis, only R1 resection reached statistical significance and was confirmed an independent prognostic factor.

CONCLUSIONS

Neoplastic involvement of PALN in peri-ampullary cancer is frequent and, so, their removal during PD could be justified. Moreover, PALN metastases should be not considered an absolute contraindication to radical surgery.

Pancreatectomy with Para-Aortic Lymph Node Dissection for Pancreatic Head Adenocarcinoma: Pattern of Nodal Metastasis Spread and Analysis of Prognostic Factors

BACKGROUND

This study investigated the prognostic impact of the exact location of nodal metastases in a subgroup of patients who underwent pancreatectomy with extended lymphadenectomy for head adenocarcinoma, with a special focus on station 16b1.

METHODS

Clinical, pathologic, and follow-up details were extracted from our database and analyzed retrospectively. Survival analysis was performed using univariate and multivariate models. We also performed a matched case-control analysis with resected patients who did not receive extended lymphadenectomy and with locally advanced patients.

RESULTS

The study population consisted of 67 patients. The rate of station 16b1 metastases was 20.9%. Station 14a-b metastases (OR = 4.28), G3 tumors (OR = 4.03), and number of PLN ≥ 8 (OR = 4.46) were independently associated with station 16b1 involvement. Among pN1 patients, station 14a-b (HR = 2.60) and station 16b1 metastases (HR = 2.40) were predictors of survival. The median disease-specific survival of 16b1+ patients was 17 months (95% CI 8.47-25.52). In the matched case-control analysis, the survival rates of resected 16b1+ patients was in between pN1/16b1- patients and locally advanced patients.

CONCLUSIONS

Metastases to station 16b1 are associated with a decreased survival in comparison with pN1/16b1- patients, yet longer than in matched locally advanced patients. Station 14 can be considered as a "junctional node" to station 16b1.

Should a standard lymphadenectomy during pancreatoduodenectomy exclude para-aortic lymph nodes for all cases of resectable pancreatic head cancer? A consensus statement by the Chinese Study Group for Pancreatic Cancer (CSPAC)

Understanding and formulating an appropriate strategy for the para-aortic lymph nodes (LN16) during curative surgery for pancreatic head cancer have been controversial for some time. This study intended to provide a recommendation for surgeons to perform an optimal curative surgery on pancreatic cancer patients with or without LN16 involvement. Based on an updated literature search and review, the members of the Chinese Study Group for Pancreatic Cancer (CSPAC) from high-volume centers reached a consensus on the issue of LN16 in pancreatic head cancer. Metastasis to LN16 is quite common in pancreatic head cancer cases. Depending on the location of the tumor, including the ventral and dorsal pancreas, there could be various lymph node drainage pathways whereby LN16 does not necessarily belong to the Group 3 lymph node stations for all cases of pancreatic head cancer. Although LN16 involvement generally indicates a poor prognosis, some cohorts of LN16-involved cases have benefited from a curative surgery, and there is still a lack of level I evidence to convince surgeons to abandon all resectable cases with LN16 positivity. Resection of LN16 combined with a standard lymphadenectomy during pancreatoduodenectomy is recommended by CSPAC, except in patients with both positive LN16 and criteria based on: i) the resectability status of primary tumor; ii) the extent of involved para-aortic lymph nodes; and iii) the serum tumor burden assessed preoperatively.

Postoperative prognosis of pancreatic cancer with para-aortic lymph node metastasis: a multicenter study on 822 patients

BACKGROUND

The prognosis of pancreatic cancer patients with metastatic para-aortic lymph node (PALN) has been reported to be extremely poor. In general, PALN metastasis has been considered as a contraindication for pancreatic resection. The aim of this study was to reevaluate the postoperative prognostic value of PALN metastasis in pancreatic cancer and to determine the validity of pancreatic surgery.

METHODS

Retrospective multicenter analysis of 882 patients who have undergone curative-intent pancreatic resection with pathological evaluation of PALNs for pancreatic ductal adenocarcinoma between 2001 and 2012 was conducted. Clinicopathological data and outcomes were evaluated with univariate and multivariate analysis.

RESULTS

In total, 102 (12.4 %) patients had positive metastasis in PALN. Patients with metastatic PALN had significantly poorer survival than those without (17 vs. 23 months; p < 0.001). Multivariable analysis of 822 patients identified adjuvant chemotherapy, primary tumor status, regional lymph node metastasis, portal vein invasion, pre- and post-operative serum CA19-9 levels, and tumor grade as independent prognostic factors. In contrast, PALN metastasis did not have a significant prognostic value. Furthermore, the multivariate prognostic analysis in patients with PALN metastasis revealed that adjuvant chemotherapy and the number of metastatic PALN were significantly associated with long-term survival. Lung metastasis as initial recurrence was observed more often in patients with PALN metastasis in comparison with those without.

CONCLUSIONS

Some pancreatic cancer patients with metastatic PALN may survive for longer than expected after pancreatectomy. Adjuvant chemotherapy and the number of metastatic PALN were critical factors for long-term survival of those patients.

Application of fluorescence in robotic general surgery: review of the literature and state of the art

The initial use of the indocyanine green fluorescence imaging system was for sentinel lymph node biopsy in patients with breast or colorectal cancer. Since then, application of this method has received wide acceptance in various fields of surgical oncology, and it has become a valid diagnostic tool for guiding cancer treatment. It has also been employed in numerous conventional surgical procedures with much success and benefit to the patient. The advent of minimally invasive surgery brought with it a new use for fluorescence in helping to improve the safety of these procedures, particularly for single-site procedures. In 2010, a near-infrared camera was integrated into the da Vinci Si System, creating a combination of technical and minimally invasive advantages that have been embraced by several experienced surgeons. The use of fluorescence, although useful, is considered challenging. Only a few studies are currently available on the use of fluorescence in robotic general surgery, whereas many articles have focused on its application in open and laparoscopic surgery. Many of these reports describe promising and satisfactory results, although with some shortcomings. The purpose of this article is to review the current status of the use of fluorescence in general surgery and particularly its role in robotic surgery. We also review potential uses in the future.

Definition of a standard lymphadenectomy in surgery for pancreatic ductal adenocarcinoma: a consensus statement by the International Study Group on Pancreatic Surgery (ISGPS)

BACKGROUND

The lymph node (Ln) status of patients with resectable pancreatic ductal adenocarcinoma is an important predictor of survival. The survival benefit of extended lymphadenectomy during pancreatectomy is, however, disputed, and there is no true definition of the optimal extent of the lymphadenectomy. The aim of this study was to formulate a definition for standard lymphadenectomy during pancreatectomy.

METHODS

During a consensus meeting of the International Study Group on Pancreatic Surgery, pancreatic surgeons formulated a consensus statement based on available literature and their experience.

RESULTS

The nomenclature of the Japanese Pancreas Society was accepted by all participants. Extended lymphadenectomy during pancreatoduodenectomy with resection of Ln's along the left side of the superior mesenteric artery (SMA) and around the celiac trunk, splenic artery, or left gastric artery showed no survival benefit compared with a standard lymphadenectomy. No level I evidence was available on prognostic impact of positive para-aortic Ln's. Consensus was reached on selectively removing suspected Ln's outside the resection area for frozen section. No consensus was reached on continuing or terminating resection in cases where these nodes were positive.

CONCLUSION

Extended lymphadenectomy cannot be recommended. Standard lymphadenectomy for pancreatoduodenectomy should strive to resect Ln stations no. 5, 6, 8a, 12b1, 12b2, 12c, 13a, 13b, 14a, 14b, 17a, and 17b. For cancers of the body and tail of the pancreas, removal of stations 10, 11, and 18 is standard. Furthermore, lymphadenectomy is important for adequate nodal staging. Both pancreatic resection in relatively fit patients or nonresectional palliative treatment were accepted as acceptable treatment in cases of positive Ln's outside the resection plane. This consensus statement could serve as a guide for surgeons and researchers in future directives and new clinical studies.