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

A comprehensive study on postoperative complications and postoperative pancreatic fistula in sporadic non-functional pancreatic neuroendocrine tumors: A retrospective cohort study

Backgrounds/Aims

Balancing surgical risks and benefits is crucial for managing non-functional pancreatic neuroendocrine tumors (NF-PNETs). Despite high postoperative pancreatic fistula (POPF) rates, studies on postoperative complications of sporadic NF-PNETs are scarce. Thus, this study aimed to investigate postoperative complications and identify risk factors for POPF.

Methods

A retrospective review of 166 NF-PNET surgeries performed at Severance Hospital between February 2000 and August 2023 was conducted.

Results

Age > 65 years and higher American Society of Anesthesiology (ASA) grade were not significantly correlated with severe complications (odds ratio [OR]: 1.10, p = 0.871 and OR: 1.47, p = 0.491, respectively). Surgical procedures included enucleation (13.9%), distal pancreatectomy (50.0%), central pancreatectomy (4.8%), pancreaticoduodenectomy (PD) (26.5%), and total pancreatectomy (4.8%). Severe complications occurred in 12.05% of surgeries. The overall incidence of all POPFs including biochemical leaks was 53%, while clinically relevant POPF (grade B or C) occurred in 7.8% of patients. Logistic regression showed that PD (OR: 3.94, p = 0.092) tended to be risk factor for POPF and that diameter of the main pancreatic duct (MPD) ≤ 3 mm was a significant risk factor for POPF (OR: 0.22, p = 0.008). A pancreas thickness (PT)/MPD ratio > 4.47 on preoperative computed tomography predicted all POPFs in PD patients (OR: 11.70, p = 0.001).

Conclusions

Age and comorbidities had no significant impact on surgical outcomes. PD was associated with higher serious complications and POPF rates. The PT/MPD ratio is a valuable preoperative tool for predicting POPF risk in PD patients.

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.

Enucleation for Sporadic Nonfunctioning Pancreatic Neuroendocrine Tumors Larger than 2 Centimeters Is Associated with Equivalent Morbidity and Survival Compared to Smaller Tumors: A Multi-Institutional Study

INTRODUCTION

Nonfunctioning pancreatic neuroendocrine tumor (NF-PanNET) ≤2 cm can be observed or resected. Surgery remains recommended for NF-PanNET >2 cm but its extent, enucleation (EN) versus formal resection, remains controversial.

METHODS

Multicentric retrospective cohort of sporadic NF-PanNET patients treated with EN. Short- and long-term outcomes were compared according to tumor size on imaging ≤2 cm versus >2 cm.

RESULTS

131 patients underwent EN for NF-PanNET, including 103 (79.0%) ≤2 cm and 28 (21.0%) >2 cm (extremes, 4-55 mm). Patients' characteristics were comparable, and tumor characteristics only differed in their diameter. Clavien III-IV complications were similar (18.4% vs. 17.9%, p = 1.00) with one death in NF-PanNET ≤2 cm. Grade B/C pancreatic fistula were comparable (16.5% vs. 10.7%, p = 0.850). In NF-PanNET >2 cm there were more pT2/3 stage tumors (85.7% vs. 21.4%, p < 0.001), similar rates of grade G2/3 tumors (25% vs. 16.5%, p = 0.408) with a median Ki67 of 2 (interquartile range: 1-3), and of lymphovascular and perineural invasions. Lymph node picking was done in 46 (35.1%) patients, with a higher median number of harvested lymph nodes in NF-PanNET >2 cm (4 vs. 3, p = 0.01). All were pN0. R0 resection rate (78.6% vs. 82.5%, respectively; p = 0.670) was equivalent. Five-year overall (100% vs. 99%, p = 0.602) and 10-year disease-free (96% vs. 92%, respectively; p = 0.532) survivals were comparable.

CONCLUSIONS

EN for selected NF-PanNET >2 cm carries equivalent morbidity, overall and disease-free survivals compared to those observed with NF-PanNET ≤2 cm.

Duodenum-preserving pancreatic head resection compared to pancreaticoduodenectomy: A systematic review and network meta-analysis of surgical outcomes

Objectives

In this systemic review and network meta-analysis, we investigated pancreaticoduodenectomy (PD), pylorus-preserving pancreaticoduodenectomy (PPPD), and different modifications of duodenum-preserving pancreatic head resection (DPPHR) to evaluate the efficacy of different surgical procedures.

Methods

A systemic search of six databases was conducted to identify studies comparing PD, PPPD, and DPPHR for treating pancreatic head benign and low-grade malignant lesions. Meta-analyses and network meta-analyses were performed to compare different surgical procedures.

Results

A total of 44 studies were enrolled in the final synthesis. Three categories of a total of 29 indexes were investigated. The DPPHR group had better working ability, physical status, less loss of body weight, and less postoperative discomfort than the Whipple group, while both groups had no differences in quality of life (QoL), pain scale scores, and other 11 indexes. Network meta-analysis of a single procedure found that DPPHR had a larger probability of best performance in seven of eight analyzed indexes than PD or PPPD.

Conclusion

DPPHR and PD/PPPD have equal effects on improving QoL and pain relief, while PD/PPPD has more severe symptoms and more complications after surgery. PD, PPPD, and DPPHR procedures exhibit different strengths in treating pancreatic head benign and low-grade malignant lesions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022342427.

Venous invasion and lymphatic invasion are correlated with the postoperative prognosis of pancreatic neuroendocrine neoplasm

BACKGROUND

To determine treatment strategies corresponding to a wide range of pancreatic neuroendocrine neoplasms staging, easier-to-use and detailed prognostic classification is required.

METHODS

Patients with pancreatic neuroendocrine neoplasms who underwent curative-intent surgery at the University of Tokyo Hospital between 2000 and 2018 were retrospectively reviewed. The presence or absence of venous and lymphatic invasion was assessed. Multivariable analysis was performed to identify the risk factors of shorter overall survival and recurrence-free survival. Patients were classified into the following 3 groups: a lymphovascular invasion 0 group, whereby both venous and lymphatic invasion were negative; an lymphovascular invasion 1 group, where either of the 2 was positive; and an lymphovascular invasion 2 group, where both were positive. The survival curves and recurrence patterns of the 3 groups were compared.

RESULTS

Eighty-nine patients were analyzed. Multivariable analysis revealed that lymphatic invasion and Ki-67 index (≥ 3.0%) were independent prognostic factors of recurrence-free survival (hazard ratio: 5.2 and 3.6). Fifty-three patients were classified as lymphovascular invasion 0, 26 as lymphovascular invasion 1, and 10 as lymphovascular invasion 2. The recurrence-free survival curves of the 3 groups were significantly stratified (10-year recurrence-free survival: 89.1% in lymphovascular invasion 0, 57.1% in lymphovascular invasion 1, and 18.3% in lymphovascular invasion 2). Five-year cumulative liver and lymph node metastasis of lymphovascular invasion 0, lymphovascular invasion 1, and lymphovascular invasion 2 were well stratified at 0% and 3.8%, 15.8% and 23.1%, and 33.3% and 70.0%, respectively.

CONCLUSION

Postoperative prognosis of resected pancreatic neuroendocrine neoplasms could be finely classified by venous invasion and lymphatic invasion. Management after curative-intent surgery for pancreatic neuroendocrine neoplasms may be changed by this new classification.

Gastroenteropancreatic neuroendocrine tumor of the accessory papilla of the duodenum: a case report

Background

Contrary to the increasing incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs), GEP-NETs of the accessory papilla of the duodenum are extremely rare. Furthermore, there have been no recommendations regarding the treatment strategy for GEP-NETs of the accessory papilla of the duodenum. We present a case of GEP-NET of the accessory papilla of the duodenum successfully treated with robotic pancreatoduodenectomy.

Case presentation

A case of a 70-year-old complaining of no symptoms was diagnosed with GEP-NET of the accessory papilla of the duodenum. A 8-mm tumor was located at the submucosal layer with a biopsy demonstrating a neuroendocrine tumor grade 1. The patient underwent robotic pancreatoduodenectomy as curative resection for the tumor. The total operative time was 406 min with an estimated blood loss of 150 mL. The histological examination revealed a well-differentiated neuroendocrine tumor with low Ki-67 index (< 1%). In the posterior areas of the pancreas, the lymph node metastases were detected. The patient was followed up for 6 months with no recurrence postoperatively.

Conclusions

Considering the potential risks of the lymph node metastases, the standard treatment strategy for GEP-NETs of the accessory papilla of the duodenum should be radical resection with pancreatoduodenectomy. Minimally invasive approach can be the alternative to the conventional open surgery.