Surgical resection of neuroendocrine tumors of the pancreas (pNETs) by minimally invasive surgery: the laparoscopic approach

Risk factors for lymph node metastasis in patients with pancreatic neuroendocrine neoplasms

BACKGROUND

Although PNENs generally have a better prognosis than pancreatic cancers, some PNENs display malignant behavior including lymph node (LN) metastasis. Complete tumor resection can be the only potentially curative treatment for patients with resectable PNENs. However, the indications for LN dissection are still controversial. Over the last decade, minimally invasive surgery such as laparoscopic pancreatic surgery (LPS) has been increasingly performed for pancreatic tumors including PNENs.

AIM

To investigate the risk factors for LN metastasis in PNENs and to select appropriate patients for limited surgery by LPS.

METHODS

From April 2001 to December 2019, 92 patients underwent pancreatic resection for PNENs at Kumamoto University Hospital. Finally, 82 patients were enrolled in this study. Using perioperative factors, we examined the predictive factors for LN metastasis in PNENs.

RESULTS

Among the 82 patients, the percentage of LN metastasis according to the pathological findings was 12% (10/82 cases). The median tumor size was 12 mm (range: 5-90 mm). The median tumor size in the LN-positive group (37 mm) was significantly larger than that in the LN-negative group (12 mm) (P = 0.0001). Multivariate analyses revealed that larger tumor size (≥ 20 mm) was an independent risk factor for LN metastasis (odds ratio 16.8, P = 0.0062). In patients with small tumors (≤ 10 mm), LN metastasis was not found.

CONCLUSION

Larger tumor size (≥ 20 mm) is an independent risk factor for LN metastasis in PNENs. In smaller PNENs (≤ 10 mm), we may be able to choose limited surgery without LN dissection.

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.

Endoscopic ultrasound-guided ethanol and radiofrequency ablation of pancreatic insulinomas: a systematic literature review

BACKGROUND

Insulinoma is the most common neuroendocrine neoplasm of the pancreas, characterised by hypoglycaemic symptoms. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and ethanol ablation (EUS-EA) are novel methods for treating insulinoma.We aimed to perform a systematic review to assess the efficacy and safety of EUS-guided ablation techniques for pancreatic insulinomas.

METHODS

We systematically searched for articles detailing EUS-guided ablations of insulinomas. We performed a qualitative analysis and summarised data on the efficacy and safety of EUS-RFA and EUS-EA techniques.

RESULTS

In total, we identified 35 case reports and case series describing 75 patients with insulinomas treatment with EUS-guided ablation. Twenty-seven patients were treated with EUS-RFA, 47 patients with EUS-EA, and 1 patient received EUS-EA and EUS-RFA in the same session. In total, 84 insulinomas were ablated (EUS-RFA: 31, EUS-EA: 53). Most insulinomas were in the head of the pancreas (40%). The clinical success rate for EUS-guided ablation techniques was 98.5%. The median glucose level was 1.95 (Q1-Q3: 1.69-2.13) mmol/L before ablation compared to 6.20 (Q1-Q3: 5.30-7.05) mmol/L after treatment. The median insulin and C-peptide levels before and after RFA/EA were 230 (Q1-Q2: 120-257) pmol/L and 41 (Q1-Q2 35-42) pmol/L; 2077 (Q1-Q2 1644-2459) pmol/L and 819 (Q1-Q2 696-1072) pmol/L, respectively. There were eleven adverse events: seven abdominal pain, two mild acute pancreatitis, one necrotising acute pancreatitis and one local hematoma. All patients recovered, and there were no periprocedural deaths.

CONCLUSIONS

EUS-guided ablation of insulinoma seems to be a safe and effective treatment and is an alternative to surgical resection in selected cases.

Minimally invasive surgery of the pancreas: a narrative review of current practice

Minimally invasive surgery has moved from the fringe of pediatric surgery to the mainstream to address a variety of problems. Pancreatic pathology, though uncommon and complex, is frequently amenable to laparoscopic intervention. Indications for pediatric pancreatic operative intervention includes trauma, congenital hyperinsulinemia and neoplasm. Children may require distal pancreatectomy, subtotal pancreatectomy, enucleation, lateral pancreaticojejunostomy and pancreaticoduodenectomy. Of these operations, all but pancreaticoduodenectomy have been successfully described in children using a minimally invasive approach. Traumatic transection of the main pancreatic duct may require operative intervention if endoscopic techniques are unsuccessful. Distal pancreatectomy has been successfully utilized in this circumstance. Additionally, near total pancreatectomy may also be performed laparoscopically although successful reports are limited. Enucleation, especially with the use of intraoperative ultrasound may avoid a large laparotomy for isolated benign masses. Finally, chronic pancreatitis resulting in a dilated main pancreatic duct may benefit from a lateral pancreaticojejunostomy. This operation has also successfully been performed in children. Included is a review of pediatric pancreatic minimally invasive operations paired with corresponding pathology.

Preoperative stenting in insulinoma located nearby pancreatic duct: a case report and literature review

Insulinoma is a rare functional neuroendocrine tumor of pancreas. The only recommended treatment is surgical removal. We present a case of a 46-year-old female patient who underwent the enucleation of insulinoma localized nearby pancreatic main duct after preoperative endoscopic insertion of pancreatic stent. The tumor was safely identified during the surgery and was enucleated without injury of pancreatic duct or postoperative complications.

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.

Clinical Impact of Organ-Preserving Surgery for Pancreatic Neuroendocrine Neoplasms: A Single-Center Experience

OBJECTIVES

Organ-preserving surgery (OPS) has been accepted for pancreatic neuroendocrine neoplasms, particularly for the management of small tumors. This study aimed to analyze the surgical outcome following this treatment at our institute, focusing on the perioperative factors and postoperative locoregional recurrence.

METHODS

We analyzed 71 consecutive patients with no synchronous liver metastasis. These patients were classified into 1 of 2 groups: the standard operation group (SOG, 41 patients) with prophylactic regional lymph node dissection and the organ-preserving surgery group (OPG, 30 patients). We performed OPS based on size criteria (tumor size <1.5 cm in nonfunctional pancreatic neuroendocrine neoplasms and <2 cm in insulinoma with no evident bulky lymph node swelling on preoperative imaging).

RESULTS

The median follow-up periods were 37 months. The OPG included enucleation, partial resection, proximal parenchymal pancreatectomy, central pancreatectomy, spleen-preserving distal pancreatectomy, and Warshaw operation. The SOG included pancreatoduodenectomy and distal pancreatectomy, showing no statistically significant differences between the 2 groups in terms of operation time, hospitalization duration, and postoperative complications. Ten patients showed lymph node metastasis (25%) only in the SOG. There were no locoregional recurrent cases in the OPG.

CONCLUSIONS

In selected patients, OPS may be effective based on the appropriate tumor size criteria.

[Indications for the Surgical Management of Pancreatic Neuroendocrine Neoplasms]

Neuroendocrine neoplasms of the pancreas (pNEN) have an increasing incidence and prevalence. Thus, this entity is of increasing clinical significance. Patients with pNEN become clinically apparent due to different and unspecific symptoms. Some tumours secrete hormones and peptides and become clinically symptomatic. In general, these tumours can metastasise early and even small tumours lead to distant metastases. Nonetheless, primary tumour size and grading are important prognostic factors. On the basis of a systematic literature research and the formulation of key issues according to the PICO system, therapeutic concepts were established. These concepts were evaluated with a Delphi process among the members of the pancreas research group and the indications for surgery group of the German Society of General and Visceral Surgery. Thus this article gives an overview of the surgical treatment modalities and indications for the treatment of pNEN. Surgery is still the gold standard in treatment and the only potential chance of cure. Surgery is indicated for sporadic as well as hereditary pNEN > 2 cm independent of the functional activity. A so called "wait and see" strategy might be indicated in smaller pNEN; however, there is little evidence for this approach. In this respect, pNEN of 1 - 2 cm represent a surgical indication. The treatment of hereditary pNEN is challenging and should be interdisciplinary. Even in the case of distant metastases, a curative approach might be feasible and multimodal treatment is indicated.