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

Novel Surgical Initiatives in Gastroenteropancreatic Neuroendocrine Tumours

PURPOSE OF REVIEW

Neuroendocrine tumours (NET) are rare entities arising from hormone producing cells in the gastroentero-pancreatic (GEP) tract. Surgery is the most common treatment of GEP-NETs.

RECENT FINDINGS

Improvements in surgical techniques allow for more locally advanced and metastasised GEP-NETs to be resected. Laparoscopic and robotically--assisted approaches are increasingly being utilised in the resection of selected GEP-NETs and are facilitated by novel intraoperative tumour localisation tools and parenchyma-sparing methods. At the same time, some authors suggest that indications for formal resections of small well differentiated non-functioning pancreatic NETs and appendiceal NETs should be more restrictive. Advancements in surgery allows for tissue-sparing resections of GEP-NETs. Indications for surgical resection and the extent of the procedure are highly dependent on GEP-NET size, localisation and grading. Robotically assisted surgeries with intraoperative ultrasound and visualisation methods as well as vessel-sparing radical retrograde lymphadenectomies for small intestinal NETs seem to be the future of GEP-NET surgery.

Laparoscopic and Open Distal Pancreatectomy-An Initial Single-Institution Experience with a Propensity Score Matching Analysis

Laparoscopic distal pancreatectomy is a minimally invasive approach for the surgical treatment of neoplasms in the distal pancreas. This study aimed to compare this approach to the open procedure. A retrospective analysis of a prospectively maintained database of 400 pancreatectomies was performed. The laparoscopic distal pancreatectomy group (LDP) was compared to the open distal pancreatectomy group (ODP). A propensity score matching analysis (PSM) was performed. From 2016 to 2023, 108 distal pancreatectomies were carried out, 19 (17.6%) laparoscopically and 89 (82.4%) openly. The conversion rate was 13.6%. The severe morbidity rates were 28.1% in the ODP group, 47.4% in the LDP group, and 15.8% in the ODP-PSM group. The difference between the latter two was statistically significant (p = 0.034) due to the high rate of Clavien-Dindo grade 3a complications (42.1% versus 10.5%, p = 0.042) in the LDP group. The 90-day mortality rates were 3.3% in the ODP group and 5.3% in the other two groups. The LDP group had a shorter duration of intravenous narcotic analgesia (5 versus 7 days, p = 0.041). There was no difference in the R0 resection or postoperative pancreatic fistula rates. Our attention should be drawn to preventing postoperative complications because the oncological outcomes are already comparable with those of the open procedure, and postoperative pain management is promising.

Minimally invasive versus open surgery for nonfunctioning pancreatic neuroendocrine tumors: a systematic review and meta-analysis

INTRODUCTION

Nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) have been diagnosed increasingly often but still represent rare pancreatic neoplasms. Surgery is a potentially curative approach for patients with NF-PNETs. In recent years, minimally invasive surgery (MIS) has been applied more frequently for surgical resection of NF-PNETs. The evidence for using MIS for NF-PNETs is still being determined and controversial.

MATERIALS AND METHODS

PubMed, Cochrane Library, and the Web of Science database were searched systematically from its inception to July 2023. All studies comparing MIS versus open surgery (OPS) of NF-PNETs were included. The primary outcomes were the incidence of overall postoperative complications and pancreas-specific complications [postoperative pancreatic fistula (POPF) and delayed gastric emptying (DGE)]. The secondary measures were duration of operation, intraoperative blood loss, and length of postoperative hospital stay. Pooled results are presented as odds ratios (OR) or mean difference (MD) with a 95% CI.

RESULTS

Five observational studies with a total of 1178 patients were included in the final analysis. The meta-analysis indicated that MIS attained less intraoperative blood loss (MD=-58.59, 95% CI [-92.76 to -24.41], P<0.01) and shorter length of hospital stay (MD=-3.07, 95% CI [-5.28 to -0.87], P<0.01) in contrast to open surgery for NF-PNETs. There were no significant differences concerning operative time (MD=52.04, 95% CI [-8.74 to 112.81], P=0.67), overall postoperative complications (OR=0.78, 95% CI [0.59-1.03], P=0.08), POPF (OR=0.99, 95% CI [0.66-1.47], P=0.94), and DGE (OR=0.58, 95% CI [0.58-1.42], P=0.67).

CONCLUSIONS

This study demonstrates that minimally invasive surgery for NF-PNETs is safe and associated with a considerably shorter postoperative hospital stay. Further studies are needed to verify the evidence.

Robotic Versus Laparoscopic Versus Open Surgery for Non-Metastatic Pancreatic Neuroendocrine Tumors (pNETs): A Systematic Review and Network Meta-Analysis

Background: This systematic review, using pairwise and network meta-analyses, aimed to compare the intraoperative, short-term, and long-term postoperative outcomes of minimally invasive surgery (MIS) and open surgery (OS) for the management of pancreatic neuroendocrine tumors (pNETs). Methods: Studies reporting on the effects of robotic, laparoscopic, and open surgery on pNETs published before November 2023 on PubMed, Scopus, and CENTRAL were analyzed. Results: Thirty-two studies with 5379 patients were included in this review, encompassing 2251 patients undergoing MIS (1334 laparoscopic, 508 robotic, and 409 unspecified MIS) and 3128 patients undergoing OS for pNETs management. Pairwise meta-analysis revealed that the MIS group had a significantly shorter length of hospital stay ((a low certainty of evidence), MD of -4.87 (-6.19 to -3.56)); less intraoperative blood loss ((a low certainty of evidence), MD of -108.47 (-177.47 to -39.47)); and decreased tumor recurrence ((a high certainty of evidence), RR of 0.46, 95% CI (0.33 to 0.63)). Subgroup analysis indicated a higher R0 resection rate and prolonged operative time for laparoscopic surgery than for OS. The network meta-analysis ranked the robotic approach as superior in terms of the length of hospital stay, followed by the laparoscopic and OS arms. Furthermore, it favored both MIS approaches over OS in terms of the R0 resection rate. No significant differences were found in severe postoperative complications, postoperative fistula formation, mortality, readmission, reoperation, or conversion rates. Conclusions: This review supports the safety of MIS for the treatment of pNETs. However, the varying certainty of evidence emphasizes the need for higher-quality studies.

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.

European Neuroendocrine Tumour Society (ENETS) 2023 guidance paper for nonfunctioning pancreatic neuroendocrine tumours

This ENETS guidance paper for well-differentiated nonfunctioning pancreatic neuroendocrine tumours (NF-Pan-NET) has been developed by a multidisciplinary working group, and provides up-to-date and practical advice on the management of these tumours. Using the extensive experience of centres treating patients with NF-Pan-NEN, the authors of this guidance paper discuss 10 troublesome questions in everyday clinical practice. Our many years of experience in this field are still being verified in the light of the results of new clinical, which set new ways of proceeding in NEN. The treatment of NF-Pan-NEN still requires a decision of a multidisciplinary team of specialists in the field of neuroendocrine neoplasms.

Predictors of postoperative complications and readmissions in laparoscopic pancreas resection: Results of a cohort 105 consecutive cases. A retrospective study

INTRODUCTION

Laparoscopic resection of the pancreas (LRP) has been implemented to a varying degree because it is technically demanding and requires a long learning curve. In the present study we analyze the risk factors for complications and hospital readmissions in a single center study of 105 consecutive LRPs.

METHODS

We conducted a retrospective study using a prospective database. Data were collected on age, gender, BMI, ASA score, type of surgery, histologic type, operative time, hospital stay, postoperative complications, degree of severity and hospital readmission.

RESULTS

The cohort included 105 patients, 63 females and 42 males with a median age and BMI of 58 (53-70) and 25.5 (22,2-27.9) respectively. Eighteen (17%) central pancreatectomies, 5 (4.8%) enucleations, 81 (77.6%) distal pancreatectomies and one total pancreatectomy were performed. Fifty-six patients (53.3%) experienced some type of complication, of which 13 (12.3%) were severe (Clavien-Dindo > IIIb) and 11 (10.5%) patients were readmitted in the first 30 days after surgery. In the univariate analysis, age, male gender, ASA score, central pancreatectomy and operative time were significantly associated with the development of complications (P <0.05). In the multivariate analysis, male gender (OR 7.97; 95% CI 1.08-58.88)), severe complications (OR 59.40; 95% CI, 7.69-458.99), and the development of intrabdominal collections (OR 8.97; 95% CI, 1.28-63.02)) were associated with hospital readmission.

CONCLUSIONS

Age, male gender, ASA score, operative time and central pancreatectomy are associated with a higher incidence of complications. Male gender, severe complications and intraabdominal collections are associated with more hospital readmissions.

Minimally Invasive Pancreatectomy: Robotic and Laparoscopic Developments

Minimally invasive pancreatectomy is increasingly used. Although offering potential advantages over open approaches, minimally invasive pancreatectomy has many challenges to maintain high-quality of oncologic resection. Multiple patient and surgical factors should be considered in planning laparoscopic or robotic resection, including the learning curve required to produce proficiency. For pancreaticoduodenectomy, distal pancreatectomy, and other pancreatic resections, a safe, margin-negative resection remains the goal. National and societal guidelines for the adoption of minimally invasive pancreatectomy are ongoing and will continue to be important as these techniques are further adopted.

Prognostic Significance and Predictors of Nodal Recurrence After Surgery for Non-Functioning Pancreatic Neuroendocrine Tumors

BACKGROUND

The prognosis of nodal recurrence after surgery for non-functioning pancreatic neuroendocrine tumors (NF-PanNETs) and its predictors have been poorly investigated. This study aimed to compare clinicopathologic features and survival between patients with nodal relapse and those with distant relapse and to identify predictors of nodal relapse after surgery for NF-PanNETs.

METHODS

All patients (n = 321) submitted to surgery for NF-PanNETs were included. Nodal recurrence was defined as the presence of one or more enlarged LNs at high-quality radiologic examinations and always confirmed by ⁶⁸Ga-DOTA-PET or biopsy.

RESULTS

Altogether, 21 patients (6 %) experienced nodal (± distant) relapse, and 35 patients (11 %) had distant recurrence alone. Isolated nodal recurrence occurred for 23 % of patients with recurrence. Overall, 11 patients died of disease, one of whom (pT3N1G3) had an isolated nodal relapse. The rate of LN metastases (81 % vs 54 %; p = 0.044) and median number of positive LNs (PLN) (3 vs 0; p = 0.019) both were significantly higher for the patients with nodal (± distant) relapse than for those with distant relapse alone. Microvascular invasion (p = 0.046), T stage (p = 0.004), N stage (N1 [p = 0.049]; N2 [p = 0.001]), M stage (p < 0.001), and necrosis (p = 0.011) independently predicted nodal relapse. After distal pancreatectomy (n = 182), 13 patients experienced nodal recurrence, 9 of whom had left paraortic LNs involvement.

DISCUSSION

Lymph nodes are not rare sites of recurrence after surgery for NF-PanNETs. Lymph node involvement is a powerful determinant of nodal relapse. Nodal relapse frequently involves LNs that are not removed during standard lymphadenectomy.

Personalisierte Resektionsverfahren bei neuroendokrinen Neoplasien des Pankreas

Neuroendokrine Neoplasien des Pankreas (pNEN) haben eine steigende Inzidenz und erhalten klinisch dadurch eine immer höhere Relevanz. Neben den hormonell inaktiven pNEN gibt es die hormonproduzierenden Tumoren, und sowohl die inaktiven als auch die aktiven pNEN können entweder sporadisch oder hereditär vorkommen. Die Behandlung orientiert sich an tumorassoziierten Faktoren, aber auch an individuellen patienteneigenen Gegebenheiten. Für die Behandlung sind individuelle maßgeschneiderte Konzepte notwendig, welche die jeweiligen Faktoren und Gegebenheiten berücksichtigen.

Evaluation of factors predicting loss of benefit provided by laparoscopic distal pancreatectomy compared to open approach

Several studies showed safety and feasibility of laparoscopic distal pancreatectomy (LDP) as compared to open distal pancreatectomy (ODP). Patients who underwent LDP or ODP (2015-2019) were included. A 1:1 propensity score matching (PSM) was used to reduce the effect of treatment selection bias. Aim of this study was to identify those factors influencing the loss of benefit (defined as a significantly better outcome compared to ODP) after LDP. Overall, 387 patients underwent DP (n = 250 LDP, n = 137 ODP). After PSM, 274 patients (n = 137 LDP, n = 137 ODP) were selected. LDP was associated with reduced intraoperative blood loss (median: 200 mL vs. 250 mL, p < 0.001), decreased wound infection rate (1% vs. 9%, p = 0.044) and shorter time to functional recovery (TFR) (median: 4 days vs. 5 days, p = 0.002). Consequently, TFR > 5 days and blood loss > 250 mL were defined as loss of benefit after LDP. In the LDP group, age > 70 years [Odds Ratio (OR) 2.744, p = 0.022] and duration of surgery > 208 min (OR 2.957, p = 0.019) were predictors of TFR > 5 days and intraoperative blood loss > 250 mL, respectively. No differences in terms of TFR were found between ODP and LDP groups in patients > 70 years (p = 0.102). Intraoperative blood loss was significantly higher in the ODP group, also when the analysis was limited to surgical procedures with operative time > 208 min (p = 0.003). In conclusion, LDP seems comparable to ODP in terms of TFR in patients aged > 70 years. This finding could be helpful in the choice of the best surgical approach in elderly patients undergoing potentially challenging DPs.

Laparoscopic versus open distal pancreatectomy: a single centre propensity score matching analysis

The laparoscopic approach is considered as standard practice in patients with body-tail pancreatic neoplasms. However, only a few randomized controlled trials (RCTs) and propensity score matching (PSM) studies have been performed. Thus, additional studies are needed to obtain more robust evidence. This is a single-centre propensity score-matched study including patients who underwent laparoscopic (LDP) and open distal pancreatectomy (ODP) with splenectomy for pancreatic neoplasms. Demographic, intra, postoperative and oncological data were collected. The primary endpoint was the length of hospital stay. The secondary endpoints included the assessment of the operative findings, postoperative outcomes, oncological outcomes (only in the subset of patients with pancreatic ductal adenocarcinoma-PDAC) and total costs. In total, 205 patients were analysed: 105 (51.2%) undergoing an open approach and 100 (48.8%) a laparoscopic approach. After PSM, two well-balanced groups of 75 patients were analysed and showed a shorter length of hospital stay (P = 0.001), a lower blood loss (P = 0.032), a reduced rate of postoperative morbidity (P < 0.001) and decreased total costs (P = 0.050) after LDP with respect to ODP. Regarding the subset of patients with PDAC, 22 patients were analysed: they showed a significant shorter length of hospital stay (P = 0.050) and a reduction in postoperative morbidity (P < 0.001) after LDP with respect to ODP. Oncological outcomes were similar. LDP showed lower hospital stay and postoperative morbidity rate than ODP both in the entire population and in patients affected by PDAC. Total costs were reduced only in the entire population. Oncological outcomes were comparable in PDAC patients.

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.

Improvement in distal pancreatectomy for tumors in the body and tail of the pancreas

Background

Pancreatic resections are complex and technically challenging surgical procedures. They often come with potential limitations to high-volume centers. Distal pancreatectomy is a relatively simple procedure in most cases. It facilitates the development of up-to-date minimally invasive surgical procedures in pancreatic surgery including laparoscopic distal pancreatectomy and robot-assisted distal pancreatectomy.

Main body

To obtain a desirable long-term prognosis, R0 resection and adequate lymphadenectomy are crucial to the surgical management of pancreatic cancer, and they demand standard procedure and multi-visceral resection if necessary. With respect to combined organ resection, progress has been made in evaluating and determining when and how to preserve the spleen. The postoperative pancreatic fistula, however, remains the most significant complication of distal pancreatectomy, with a rather high incidence. In addition, a safe closure of the pancreatic remnant persists as an area of concern. Therefore, much efforts that focus on the management of the pancreatic stump have been made to mitigate morbidity.

Conclusion

This review summarized the historical development of the techniques for pancreatic resections in recent years and describes the progress. The review eventually looked into the controversies regarding distal pancreatectomy for tumors in the body and tail of the pancreas.

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.