Systematic review and meta-analysis on laparoscopic pancreatic resections for neuroendocrine neoplasms (PNENs)

Minimally invasive versus open distal pancreatectomy for resectable pancreatic neuroendocrine tumors: A propensity score matched multicentric comparative French study

BACKGROUND

Minimally invasive surgery has gained momentum for left pancreatic resections. However, debate remains about whether it has any advantage over open surgery for distal pancreatectomy for pancreatic neuroendocrine tumors.

METHODS

This retrospective review examined pancreatectomies performed for resectable pancreatic neuroendocrine tumors at 21 centers in France between January 2014 and December 2018. Short and long-term outcomes were compared before and after propensity score matching based on tumor size, sex, age, body mass index, center, and method of pancreatic transection.

RESULTS

During the period study, 274 patients underwent left pancreatic resection for pancreatic neuroendocrine tumors [109 underwent distal splenopancreatectomy, and 165 underwent spleen-preserving distal pancreatectomy [(splenic vessel preservation (n = 97; 58.7%)/splenic vessel resection (n = 68; 41.3%)]. Before propensity score matching, minimally invasive surgery was associated with a lower rate of major morbidity (P = .004), lower rate of postoperative delayed gastric emptying (P = .04), and higher rate of "textbook" outcomes (P = .04). After propensity score matching, there were 2 groups of 54 patients (n = 30 distal splenopancreatectomy; n = 78 spleen-preserving distal pancreatectomy). Minimally invasive surgery was associated with less blood loss (P = .05), decreased rate of major morbidity (6% vs. 24%; P = .02), less delayed gastric emptying (P = .05) despite similar rates of postoperative fistula, hemorrhage, and reoperation (P > .05). The 5-year overall survival (79% vs. 75%; P = .74) and recurrence-free survival (10% vs 17%; P = .39) were similar.

CONCLUSION

Minimally invasive surgery for left pancreatic resection can be safely proposed for patients with resectable left pancreatic neuroendocrine tumors. Minimally invasive surgery decreases the rate of major complications while providing comparable long-term oncologic outcomes.

Surgical Management and Long-Term Evaluation of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) arise from neuroendocrine cells and are a rare class of heterogenous tumors with increasing incidence. The diagnosis, staging, treatment, and prognosis of PNETs depend heavily on identifying the histologic features and biological mechanisms. Here, the authors provide an overview of the diagnostic workup (biomarkers and imaging), grade, and staging of PNETs. The authors also explore associated genetic mutations and molecular pathways and describe updated guidelines on surgical and systemic treatment modalities.

European Neuroendocrine Tumor Society 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromes

This ENETS guidance paper aims to provide practical advice to clinicians for the diagnosis, treatment and follow-up of functioning syndromes in pancreatic neuroendocrine tumours (NET). A NET-associated functioning syndrome is defined by the presence of a clinical syndrome combined with biochemical evidence of inappropriately elevated hormonal levels. Different hormonal syndromes can be encountered in pancreatic NET patients, including insulinoma, gastrinoma as well as the rare glucagonoma, VIPoma, ACTHoma, PTHrPoma, carcinoid syndrome, calcitoninoma, GHRHoma and somatostatinoma. The recommendations provided in this paper focus on the biochemical, genetic and imaging work-up as well as therapeutic management of the individual hormonal syndromes in well-differentiated, grade 1-3, functioning NET with the primary tumour originating in the pancreas, and for specific subtypes also in the duodenum.

Updated Principles of Surgical Management of Pancreatic Neuroendocrine Tumours (pNETs): What Every Surgeon Needs to Know

Simple Summary

In this narrative review, we update the surgical management of pancreatic neuroendocrine tumours (pNETs) and highlight key elements in view of the recent literature. These tumours are rare and suffer from a lack of data and randomized controlled trials. The pNETs management is difficult due to their heterogeneity and the risks associated with pancreatic surgery. Innovative managements such as “watch and wait” strategies, parenchymal sparing surgery and minimally invasive approach are emerging. The correct use of all these therapeutic options requires a good selection of patients but also a constant update of knowledge.

Abstract

Pancreatic neuroendocrine tumours (pNETs) represent 1 to 2% of all pancreatic neoplasm with an increasing incidence. They have a varied clinical, biological and radiological presentation, depending on whether they are sporadic or genetic in origin, whether they are functional or non-functional, and whether there is a single or multiple lesions. These pNETs are often diagnosed at an advanced stage with locoregional lymph nodes invasion or distant metastases. In most cases, the gold standard curative treatment is surgical resection of the pancreatic tumour, but the postoperative complications and functional consequences are not negligible. Thus, these patients should be managed in specialised high-volume centres with multidisciplinary discussion involving surgeons, oncologists, radiologists and pathologists. Innovative managements such as “watch and wait” strategies, parenchymal sparing surgery and minimally invasive approach are emerging. The correct use of all these therapeutic options requires a good selection of patients but also a constant update of knowledge. The aim of this work is to update the surgical management of pNETs and to highlight key elements in view of the recent literature.

Minimally Invasive Versus Open Pancreatectomy for Right-Sided and Left-Sided G1/G2 Nonfunctioning Pancreatic Neuroendocrine Tumors: A Multicenter Matched Analysis with an Inverse Probability of Treatment-Weighting Method

BACKGROUND

Limited evidence exists for the safety and oncologic efficacy of minimally invasive surgery (MIS) for nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) according to tumor location. This study aimed to compare the surgical outcomes of MIS and open surgery (OS) for right- or left-sided NF-PNETs.

METHODS

The study collected data on patients who underwent surgical resection (pancreatoduodenectomy, distal/total/central pancreatectomy, duodenum-preserving pancreas head resection, or enucleation) of a localized NF-PNET between January 2000 and July 2017 at 14 institutions. The inverse probability of treatment-weighting method with propensity scores was used for analysis.

RESULTS

The study enrolled 859 patients: 478 OS and 381 MIS patients. A matched analysis by tumor location showed no differences in resection margin, intraoperative blood loss, or complications between MIS and OS. However, MIS was associated with a longer operation time for right-sided tumors (393.3 vs 316.7 min; P < 0.001) and a shorter postoperative hospital stay for left-sided tumors (8.9 vs 12.9 days; P < 0.01). The MIS group was associated with significantly higher survival rates than the OS group for right- and left-sided tumors, but survival did not differ for the patients divided by tumor grade and location. Multivariable analysis showed that MIS did not affect survival for any tumor location.

CONCLUSION

The short-term outcomes offered by MIS were comparable with those of OS except for a longer operation time for right-sided NF-PNETs. The oncologic outcomes were not compromised by MIS regardless of tumor location or grade. These findings suggest that MIS can be performed safely for selected patients with localized NF-PNETs.

Updated Meta-analysis of Minimally Invasive Versus Open Surgery for Pancreatic Neuroendocrine Neoplasms

OBJECTIVES

The aim of this study was to compare the short-term and long-term outcomes of minimally invasive surgery (MIS) with those of open pancreas surgery (OPS) for the treatment of pancreatic neuroendocrine neoplasms (pNENs).

METHODS

Studies reporting the effects of MIS and OPS for pNENs, published on PubMed, Embase, and Cochrane Library before May 2020 were reviewed.

RESULTS

Seventeen cohort studies with a total of 1853 patients were eligible for analysis, including 655 patients in the MIS group and 1198 patients in the OPS group. The estimated blood loss, postoperative hospitalization time, overall complications, severe complications, spleen preservation, mortality, and recurrence in the MIS group were lower than those in the OPS group. The R0 rate, 3-year overall survival (OS), and 5-year OS in the MIS group were higher than those in the OPS group. There were no significant differences in operative time, postoperative pancreatic fistula, clinical postoperative pancreatic fistula, postoperative bleeding, reoperation, readmission, and 1-year OS.

CONCLUSIONS

Minimally invasive surgery can reach lower recurrence rate, higher long-term survival rate, and better outcomes in terms of estimated blood loss, postoperative hospitalization time, R0 rate, mortality, overall complications, and severe complications for pNENs. More high quality studies need to be conducted for further verification.

The Role of Laparoscopic Surgery in Localized Pancreatic Neuroendocrine Tumours

Pancreatic neuroendocrine tumours (PNETs) are a rare and heterogeneous group of tumours with various clinical manifestations and biological behaviours. They represent approximately 2-4% of all pancreatic tumours, with an incidence of 2-3 cases per million people. PNETs are classified clinically as non-functional or functional, and pancreatic resection is recommended for lesions greater than 2 cm. The surgical approach can involve "typical" and "atypical" resections depending on the number, size and location of the tumour. Typical resections include pancreaticoduodenectomy, distal pancreatectomy enucleation and, rarely, total pancreatectomy. Atypical resections comprise central pancreatectomies or enucleations. Minimally invasive pancreatic resection has been proven to be technically feasible and safe in high-volume and specialized centres with highly skilled laparoscopic surgeons, with consolidated benefits for patients in the postoperative course. However, open and minimally invasive pancreatic surgery remains to have a high rate of complications; there is no specific technical contraindication to minimally invasive pancreatic surgery, but an appropriate patient selection is crucial to obtain satisfactory clinical and oncological outcomes.

Update on gastroenteropancreatic neuroendocrine tumors

The incidence gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) has dramatically risen over the last three decades, probably due to the increased detection of asymptomatic lesions. The diagnostic work-up for patients with suspected GEP-NENs is based on conventional imaging, endoscopy, pathology, and functional imaging, including ⁶⁸Gallium-DOTATATE PET and ¹⁸F-FDG PET. The choice of the best treatment strategy should be based on the evaluation of tumor-related features and patient's characteristics. A conservative management, consisting of active surveillance or endoscopic resection, has been advocated for patients with small, incidentally discovered, nonfunctioning tumors without features of aggressiveness. On the other hand, surgery with lymphadenectomy, also with a minimally invasive approach, represents the gold standard for the curative treatment of localized disease. Moreover, surgical resection plays an important role also in the context of a multimodal treatment strategy for patients with advanced GEP-NENs. Finally, a wide range of medical therapies, comprising somatostatin analogues, peptide receptor radionuclide therapy, target therapies and several chemotherapy regimens, can be offered to patients with advanced GEP-NENs not amenable of surgical resection, according to the biological and molecular features of their disease.

The Landmark Series: Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) comprise a heterogeneous group of neoplasms arising from pancreatic islet cells that remain relatively rare but are increasing in incidence worldwide. While significant advances have been made in recent years with regard to systemic therapies for patients with advanced disease, surgical resection remains the standard of care for most patients with localized tumors. Although formal pancreatectomy with regional lymphadenectomy is the standard approach for most PNETs, pancreas-preserving approaches without formal lymphadenectomy are acceptable for smaller tumors at low risk for lymph node metastases. Furthermore, observation of small, asymptomatic, low-grade PNETs is a safe, initial strategy and is generally recommended for tumors < 1 cm in size. In this Landmark Series review, we highlight the critical studies that have defined the surgical management of PNETs.

[Gastroenteropancreatic neuroendocrine neoplasms-Heterogeneity, management and perspectives of treatment and research]

The term neuroendocrine neoplasms (NEN) encompasses a molecularly and biologically very heterogeneous group of tumors, which have in common their origin in neuroendocrine cells. The also very heterogeneous subgroup of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) is the best classified and investigated group. This article provides a systematic review of the current classification, diagnostics and treatment options of GEP-NEN. In order to achieve a better overview, it was consciously decided not to use an approach based on the primary localization. Instead, a thematic organization according to classification, clinical phenotype, diagnostics and treatment was chosen.

Surgical management of primary pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) are the second most common malignancy of the pancreas, and their incidence is increasing. PanNETs are a diverse group of diseases which range from benign to malignant, can be sporadic or associated with genetic mutations, and be functional or nonfunctional. In as much, the treatment and management of PanNETs can vary from a "Wait and See" approach to orthotopic liver transplantation (OLT). Despite this, surgical resection is still the primary treatment modality to achieve cure. This review focuses on the surgical management of PanNETs.

Surgical Principles in the Management of Pancreatic Neuroendocrine Neoplasms

OPINION STATEMENT

Pancreatic neuroendocrine neoplasms (PanNENs) are increasingly recognized entities, whose incidence has dramatically grown during the last two decades. Surgery plays a pivotal role in their management as it represents the only chance of cure. Since PanNENs display a wide range of aggressiveness, their surgical management needs to be tailored on tumor's and patient's characteristics. Currently, there are several open questions and burning issues in the field of PanNEN, such as the management of asymptomatic nonfunctioning pancreatic neuroendocrine tumors (NF-PanNET) ≤ 2 cm. An active surveillance of these small lesions has been demonstrated to be safe although the available evidences are only based on retrospective studies. On the other hand, formal pancreatic resection associated with lymphadenectomy represents the gold standard for patients with localized NF-PanNEN > 2 cm or NF-PanNEN ≤ 2 cm in the presence of symptoms, dilation of the main pancreatic duct or suspicion of nodal metastases. Surgery plays also an important role in the setting of metastatic disease. In particular, surgery is generally recommended in the presence of low-grade, resectable, metastatic disease, but several series have reported also a survival benefit of palliative primary tumor resection in patients with unresectable liver metastases. The role of surgery in PanNEN G3 is still controversial. Indeed, surgery is associated with an improved survival in patients with well-differentiated PanNET G3, whereas there is almost no survival benefit in case of poorly differentiated lesions.

Outcomes after distal pancreatectomy for neuroendocrine neoplasms: a retrospective comparison between minimally invasive and open approach using propensity score weighting

BACKGROUND

Pancreatic neuroendocrine neoplasms (PanNEN) are ideal entities for minimally invasive surgery. The advantage of the laparoscopic approach in terms of complications, length of stay (LOS) and cosmetic results has been previously demonstrated. However, scarce data are available on long-term oncological outcomes. Aim of this study was to compare short-term postoperative outcomes, pathological findings and long-term oncological results of minimally invasive distal pancreatectomy (MIDP) and open distal pancreatectomy (ODP) for PanNEN.

METHODS

Patients who underwent ODP or MIDP for nonfunctioning PanNEN (NF-PanNEN) were retrospectively analyzed. Inverse probability of treatment weighting using propensity score was performed to compare the outcomes of MIDP and ODP.

RESULTS

Overall, 124 patients were included in the study: 84 underwent OPD, whereas 40 were submitted to MIDP. The rate of high-grade postoperative complications was significantly lower in the MIDP group (p = 0.005, grade of complication with highest estimated probability 0 vs 2) and the postoperative LOS was significantly shorter after MIDP (p < 0.001, estimated days 8 versus 10). The number of examined lymph nodes (ELN) in the ODP group was significantly higher (p = 0.0036, estimated number of ELN 13 vs 10). Similar disease-free survival and overall survival were reported for the two groups (p = 0.234 and p = 0.666, respectively).

CONCLUSIONS

Although MIDP for PanNEN seems to be associated with a lower number of ELN, long-term survival is not influenced by the type of surgical approach. MIDP is advantageous in terms of postoperative complications and LOS, but prospective studies are needed to confirm the overall oncological quality of resection in this group of neoplasms.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

Contemporary surgical management of the Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1

About 30% of patients with MEN1 develop a Zollinger-Ellison syndrome. Meanwhile it is well established that the causative gastrinomas are almost exclusively localized in the duodenum and not in the pancreas, MEN1 gastrinomas occur multicentric and are associated with hyperplastic gastrin cell lesions and tiny gastrin-producing micro tumors in contrast to sporadic duodenal gastrinomas. Regardless of the high prevalence of early lymphatic metastases, the survival is generally good with an aggressive course of disease in only about 20% of patients. Symptoms can be controlled medically. The indication, timing, type, and extent of surgery are highly controversial and are discussed in detail in this article by a thorough and critical review of literature. More radical procedures, like partial pancreaticoduodenectomy, are weighed against less aggressive local excision of gastrinomas and the pros and cons of both approaches are discussed in terms of long-term morbidity, biochemical cure, and survival.

Indications for resection and perioperative outcomes of surgery for pancreatic neuroendocrine neoplasms in Germany: an analysis of the prospective DGAV StuDoQ|Pancreas registry

PURPOSE

Pancreatic neuroendocrine neoplasms (pNENs) are rare, and their surgical management is complex. This study evaluated the current practice of pNEN surgery across Germany, including its adherence with guidelines and its perioperative outcomes.

METHODS

Patients who underwent surgery for pNENs (April 2013-June 2017) were retrieved from the prospective StuDoQ|Pancreas registry of the German Society of General and Visceral Surgery and retrospectively analyzed.

RESULTS

A total of 287 patients (53.7% male) with a mean age of 59.2 ± 14.2 years old underwent pancreatic resection for pNENs. Tumors were localized in the pancreatic head (40.4%), body (23%), or tail (36.6%). A total of 239 (83.3%) patients underwent formal resection with lymphadenectomy, 40 (14%) parenchyma-sparing resection, and 8 (2.8%) only exploration. Fifty (17.4%) patients underwent a minimally invasive approach. Among the 245 patients with complete pathological information, 42 (17.1%) had distant metastases, 78 (31.8%) had stage I tumors, 74 (30.2%) stage II, and 51 (20.8%) stage III. A total of 112 (45.7%) patients had G1 tumors, 101 (41.2%) G2, and 24 (9.8%) G3. Nodal involvement on imaging was an independent predictor of lymph node metastasis according to the multivariable analysis (odds ratio: 0.057; 95% confidence interval: 0.016-0.209; p < 0.01). R0 resection was reported in 240 (83.6%) patients. The 30- and 90-day mortality rates were 2.8% and 4.2%, respectively.

CONCLUSION

In Germany the rate of potential curative resection for pNEN is high. However, formal pancreatic resection seems to be overrepresented, while minimally invasive resection is underrepresented.

[Surgical strategies for small sporadic neuroendocrine pancreatic tumors]

Small (<2 cm) sporadic neuroendocrine pancreatic neoplasms (pNENs) are a heterogeneous group of neoplasms, which can be separated into functionally active or non-functional tumors. Functionally active pNENs release various hormones, such as insulin, gastrin, glucagon and vasoactive intestinal hormones and therefore lead to severe symptoms independent of their size. The main symptoms include hypoglycemia, coma (insulinoma), diarrhea (gastrinoma, VIPoma), intestinal ulcers (gastrinoma) and hyperglycemia (glucagonoma). Asymptomatic inactive pNENs do not cause a hormonal syndrome even though in immunohistochemistry they are positive for various hormones and endocrine markers (e.g. chromogranin and synaptophysin). Non-active small pNENs are increasingly being found because of the widespread use of high-resolution imaging and are named incidental pNENs. The current therapy algorithms of small functionally active and non-functional pNENs are very different and include besides non-operative management and surveillance (wait and see strategy) of non-active pNENs (G1, low G2), all minimally invasive, open and robotic techniques of pancreas resection. Until today almost all recommendations of surgical and nonsurgical therapy algorithms have been established based on retrospective data.

Short-term and long-term outcomes after robot-assisted versus laparoscopic distal pancreatectomy for pancreatic neuroendocrine tumors (pNETs): a multicenter comparative study

PURPOSE

Minimally invasive surgery has increasingly gained popularity as a treatment of choice for pancreatectomy with encouraging initial results in robotic distal pancreatectomy (RDP). However, few data are available on the comparison between RDP and laparoscopic distal pancreatectomy (LDP) for pancreatic neuroendocrine tumors (pNETs). Our aim, thus, is to compare perioperative and long-term outcomes as well as total costs of RDP and LDP for pNETs.

METHODS

All RDPs and LDPs for pNETs performed in four referral centers from 2008 to 2016 were included. Perioperative outcomes, histopathological results, overall (OS) and disease-free survival (DFS), and total costs were evaluated.

RESULTS

Ninety-six RDPs and 85 LDPs were included. Demographic and clinical characteristics were comparable between the two cohorts. Operative time was 36.5 min longer in the RDP group (p = 0.009) but comparable to LDP after removing the docking time (247.9 vs 233.7 min; p = 0.6). LDP related to a lower spleen preservation rate (44.7% vs 65.3%; p < 0.0001) and higher blood loss (239.7 ± 112 vs 162.5 ± 98 cc; p < 0.0001). Advantages in operative time for RDP were documented in case of the spleen preservation procedures (265 ± 41.52 vs 291 ± 23 min; p = 0.04). Conversion rate, postoperative morbidity, and pancreatic fistula rate were similar between the two groups, as well as histopathological data, OS, and DFS. Significant advantages were evidenced for LDP regarding mean total costs (9235 (± 1935) € vs 11,226 (± 2365) €; p < 0.0001).

CONCLUSIONS

Both RDP and LDP are safe and efficacious for pNETs treatment. However, RDP offers advantages with a higher spleen preservation rate and lower blood loss. Costs still remain the main limitation of the robotic approach.

Minimally invasive versus open distal pancreatectomy for pancreatic neuroendocrine tumors: An analysis from the U.S. neuroendocrine tumor study group

BACKGROUND

To determine short- and long-term oncologic outcomes after minimally invasive distal pancreatectomy (MIDP) with open distal pancreatectomy (ODP) for the treatment of pancreatic neuroendocrine tumor (pNET).

METHODS

The data of the patients who underwent curative MIDP or ODP for pNET between 2000 and 2016 were collected from a multi-institutional database. Propensity score matching (PSM) was used to generate 1:1 matched patients with MIDP and ODP.

RESULTS

A total of 576 patients undergoing curative DP for pNET were included. Two hundred and fourteen (37.2%) patients underwent MIDP, whereas 362 (62.8%) underwent ODP. MIDP was increasingly performed over time (2000-2004: 9.3% vs 2013-2016: 54.8%; P < 0.01). In the matched cohort (n = 141 in each group), patients who underwent MIDP had less blood loss (median, 100 vs 200 mL, P < 0.001), lower incidence of Clavien-Dindo ≥ III complications (12.1% vs 24.8%, P = 0.026), and a shorter hospital stay versus ODP (median, 4 versus 7 days, P = 0.026). Patients who underwent MIDP had a lower incidence of recurrence (5-year cumulative recurrence, 10.1% vs 31.1%, P < 0.001), yet equivalent overall survival (OS) rate (5-year OS, 92.1% vs 90.9%, P = 0.550) compared with patients who underwent OPD.

CONCLUSION

Patients undergoing MIDP over ODP in the treatment of pNET had comparable oncologic surgical metrics, as well as similar long-term OS.

Role of surgery in pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumours (PNETs) are rare. They are generally accepted to be slow-growing and have an indolent course. These tumours can be non-functioning or functioning, consisting of a biochemically heterogeneous group of tumours including insulinomas, gastrinomas, carcinoids and glucagonomas. Although surgery remains the mainstay of treatment, controversy still exists especially for non-functioning tumours <2 cm in size. Whether these should be resected or undergo intensive surveillance remains unclear. The surgical approach depends on local expertise. Many studies have shown comparable short-term surgical outcome with laparoscopic pancreatic resection compared to open techniques, however data on long-term oncological outcome are still lacking. On the other hand, liver metastasis occurs in as high as 80% of PNET patients. Five-year survival rate is only 30% if left untreated compared to 60-80% if complete resection is achieved. Current evidence supports liver resection with an aim for symptomatic control and to improve survival in those with respectable disease and no extra-hepatic metastasis. Palliative debunking can be considered in those with intractable symptoms. This article reviews the current evidence on pancreatic resection for PNETs, in particular the role of laparoscopic resection and the management of liver metastasis.

Surgical resection of pancreatic neuroendocrine neoplasm by minimally invasive surgery-the robotic approach?

Over the past decade, there has been increasing adoption of minimally invasive pancreatic surgery world-wide and this has naturally expanded to the management of pancreatic neuroendocrine neoplasms (PNENs). More recently, robotic pancreatic surgery (RPS) was introduced to overcome the limitations during laparoscopic pancreatic surgery (LPS). Due to the relative rarity of PNEN and the novelty of minimally invasive pancreatic surgery in particular RPS today, the evidence for robotic surgery in PNENs remains extremely limited. Presently, the available evidence is limited to a few low level retrospective case-control studies. These studies suggest that RPS may be associated with a higher splenic preservation rates and lower open conversion rates compared to conventional laparoscopic surgery. Ideally a prospective randomized trial should be performed but this would be extremely challenging due to the rarity of PNEN, making it almost impossible to conduct a sufficiently powered trial.

Laparoscopic management of neuroendocrine tumors: state-of-the-art

Over recent years, minimally invasive pancreatic resections have increasingly been reported in the literature. Even though pancreatic surgery is still considered a challenge for surgeons due to its technical difficulties and high morbidity, the consolidation of minimally invasive pancreatic surgery has included the treatment of pancreatic neuroendocrine tumors (PNETs). This article presents a systematic review of the literature with regards to the laparoscopic treatment of PNETs in order to assess the safety and feasibility of laparoscopic pancreatic resections.

Laparoscopic versus open distal pancreatectomy for nonfunctioning pancreatic neuroendocrine tumors: a large single-center study

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) account for 1-2% of all pancreatic neoplasms. Nonfunctioning PNETs (NF-PNETs) account for 60-90% of all PNETs. Laparoscopic distal pancreatectomy (LDP) is becoming the treatment of choice for benign lesions in the body and tail of the pancreas. However, LDP has not yet been widely accepted as the gold standard for NF-PNETs. The purpose of this study is to evaluate the clinical and oncologic outcomes after laparoscopic versus open distal pancreatectomy (ODP) for NF-PNETs.

METHODS

Between April 1995 and September 2016, 94 patients with NF-PNETs underwent open or laparoscopic distal pancreatectomy at Samsung Medical Center. Patients were divided into two groups: those who underwent LDP and those who underwent ODP. Both groups were compared in terms of clinical and oncologic variables.

RESULTS

LDP patients had a significantly shorter hospital stay compared with ODP patients, amounting to a mean difference of 2 days (p < 0.001). Overall complication rates did not differ significantly between the ODP and LDP groups (p = 0.379). The 3-year overall survival rates in the ODP and LDP groups were 93.7 and 100%, respectively (p = 0.069).

CONCLUSIONS

In this study, LDP for NF-PNETs had similar oncologic outcomes compared with ODP. In addition, LDP was associated with a shorter hospital stay compared with ODP. Therefore, LDP is a safe and effective procedure for patients with NF-PNETs. A multicenter study and a randomized controlled trial are needed to better assess the clinical and oncologic outcomes.

Is there a role for near-infrared technology in laparoscopic resection of pancreatic neuroendocrine tumors? Results of the COLPAN "colour-and-resect the pancreas" study

BACKGROUND

The intraoperative identification of pancreatic neuroendocrine tumors (PanNETs) is of utmost importance to drive their laparoscopic resection. Near-infrared (NIR) surgery has emerged as a new technique for localizing tumors or neoplastic tissue. This study aimed to explore the results of the application of NIR in the laparoscopic resection of PanNETs.

METHODS

Per protocol we enrolled ten subjects undergoing laparoscopic pancreatic surgery for PanNET from March 2016 to October 2016. During surgery, the patients were injected with indocyanine green dye (ICG, 25 mg given in 5 boli of 5 mg each). The switch-activation of NIR was performed to identify PanNETs. An ex-post analysis of the images was realized using ImageJ Software® to calculate the fluorescence signal.

RESULTS

NIR imaging identified all ten PanNETs. Nine (90%) laparoscopic distal pancreatectomy with splenectomy and one (10%) laparoscopic enucleation were performed. The mean maximum tumor dimension was 2.4 cm (range 1-4 cm). Eight non-functioning PanNETs (80%) and two insulinomas (20%) were found at the final pathology. Nine out of ten (90%) PanNETs were detected after the second ICG bolus. The mean latency time was 80 s and the mean visibility time was 220 s. The peak of tumor visualization was reached 20 min after the last bolus. This finding was confirmed by the ex-post analysis of the fluorescence signal (mean signal-to-background ratio of 7.7, p = 0.001). NIR identified two additional lesions, which turned out to be normal lymph nodes at final pathology. A fluorescent signal was identified at the bed of the enucleation, and thus, a further exeresis was performed and final pathology revealed that is was residual neoplastic tissue.

CONCLUSIONS

This explorative study shows that NIR with ICG can have a role in laparoscopic pancreatic resection of PanNETs. Further studies are needed to assess the proper setting and role of this new and promising technology.

Laparoscopic surgery for pancreatic neoplasms: the European association for endoscopic surgery clinical consensus conference

BACKGROUND

Introduced more than 20 years ago, laparoscopic pancreatic surgery (LAPS) has not reached a uniform acceptance among HPB surgeons. As a result, there is no consensus regarding its use in patients with pancreatic neoplasms. This study, organized by the European Association for Endoscopic Surgery (EAES), aimed to develop consensus statements and clinical recommendations on the application of LAPS in these patients.

METHODS

An international panel of experts was selected based on their clinical and scientific expertise in laparoscopic and open pancreatic surgery. Each panelist performed a critical appraisal of the literature and prepared evidence-based statements assessed by other panelists during Delphi process. The statements were further discussed during a one-day face-to-face meeting followed by the second round of Delphi. Modified statements were presented at the plenary session of the 24th International Congress of the EAES in Amsterdam and in a web-based survey.

RESULTS

LAPS included laparoscopic distal pancreatectomy (LDP), pancreatoduodenectomy (LPD), enucleation, central pancreatectomy, and ultrasound. In general, LAPS was found to be safe, especially in experienced hands, and also advantageous over an open approach in terms of intraoperative blood loss, postoperative recovery, and quality of life. Eighty-five percent or higher proportion of responders agreed with the majority (69.5%) of statements. However, the evidence is predominantly based on retrospective case-control studies and systematic reviews of these studies, clearly affected by selection bias. Furthermore, no randomized controlled trials (RCTs) have been published to date, although four RCTs are currently underway in Europe.

CONCLUSIONS

LAPS is currently in its development and exploration stages, as defined by the international IDEAL framework for surgical innovation. LDP is feasible and safe, performed in many centers, while LPD is limited to few centers. RCTs and registry studies are essential to proceed with the assessment of LAPS.